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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for the fabrication of models of teeth and their arrangement, especially so-called serrated models, with the teeth being detachably connected, either individually or in groups, with a base plate.
2. Description of the Prior Art
For various dental work, it is necessary to have a true-to-size tooth and jaw model, a so-called master model. To produce such a model, a plaster of Paris imprint is taken of the jaw of the patient. The tooth arrangement model that is obtained is generally secured to a base plate, which is generally also made of plaster of Paris. For certain dental work, for example when fitting crowns, caps, or bridges, it is desirable to be able to remove individual teeth, or groups of teeth in the form of segments, from the base plate, and to be able to accurately reinsert them after the work is complete. For this purpose, with conventional models, pins, so-called dowel pins, are provided, one end of which is fixedly connected to the tooth arrangement segments, with the other free end fitting into corresponding holes provided in the base plate. When the dowels pins are withdrawn from the holes, relatively high frictional forces result, preventing the segments from accidentally coming loose from the base plate.
Unfortunately, this dowel pin technology has, among others, the following drawbacks:
1. The pins must be disposed exactly parallel to one another, since this is the only way to provide for a problem-free removal and reinsertion of tooth arrangement segments. Relatively complicated and expensive pin-setting apparatus is used for placing the pins.
2. A precise seating of the individual tooth arrangement segments can be achieved only with difficulty, especially when the pins and holes become worn due to frequent removal.
3. Generally, the base plate can be used only once, since the pins and holes are precisely disposed relative to one another, and in practice it is not possible to insert pins into a tooth arrangement in such a manner that they will fit exactly in an existing base plate that is already provided with holes.
4. Models for crowns and bridges are generally made of wax. With all models where the tooth arrangement is held on the base plate by frictional forces, there exists the serious drawback that in order to remove the segments, relatively high frictional forces must be overcome. In so doing, tilting is unavoidable, so that damage to the parts that are modeled in wax can easily occur.
Attempts have already been made with such tooth models to dispense with the use of dowel pins. Without exception, all of the proposals for realizing this possibility also assured connection between the tooth arrangement and the base plate by using frictional forces. For example, European Patent application No. 44 223 discloses such a model, the tooth arrangement of which, on the underside, is provided with a pattern of parallel zig-zagged ribs in grooves. The upper surface of the base plate is provided with a pattern that is complementary to the pattern of the tooth arrangement. When the tooth arrangement and base plate are placed together, the ribs in grooves mesh with one another, thus assuring connection of the two parts via frictional forces. However, this proposal also results in the aforementioned difficulties. In particular, there exists the danger outlined above in paragraph number 4, namely damage to the model parts made of wax when the individual tooth segments are removed from the base plate.
An object of the present invention is to provide an apparatus for the fabrication of tooth arrangement models having removable tooth arrangement segments, with such segments being adapted to be secured to the base plate in a simple and precise manner without the seating of the segments becoming loose after repeated removal, and without there existing the danger of damaging models made of wax.
BRIEF DESCRIPTION OF THE DRAWINGS
This object, and other objects and advantages of the present invention, will appear more clearly from the following specification in conjunction with the accompanyin schematic drawing, in which:
FIG. 1 is an exploded, perspective view of one exemplary embodiment of the inventive apparatus in conjunction with a tooth arrangement;
FIG. 2 is a cross-sectional view of the tooth arrangement support and is taken along the line II--II in FIG. 1;
FIG. 3 is a bottom view of a base plate showing the screw connection of the tooth arrangement support; and
FIG. 4 is a cross-sectional view taken along the line IV--IV in FIG. 3.
SUMMARY OF THE INVENTION
Pursuant to the present invention, the aforementioned object is realized by an apparatus for the fabrication of models of teeth and their arrangement, which apparatus comprises: a base plate, and a tooth arrangement support, especially approximately a U-shaped support, that is detachably connected with the base plate via magnetic forces.
For this purpose, both the tooth arrangement support and the base plate respectively contain magnetic material. The term "magnetic material" means that at least one of the two parts contains permanently magnetic material, while the other part contains magnetizable or also permanently magnetic material.
The magnetic materials are preferably in the form of filled synthetic materials, which have the advantage that they can be easily shaped and worked. Fillers include conventional magnetic materials in pulverious form, such as iron, cobalt, nickel, alloys thereof, ferrites, etc.
The use of magnetic forces to ensure the connection between the tooth arrangement support and the base plate offers the advantage that the force that effects the connection always remains constant, and is not adversely affected by the wearing away of material. Since frictional forces are to a large extent eliminated, it is also not necessary to have to carry out sudden or jerky movements in order to overcome such forces, which movements otherwise easily lead to tilting and hence to damage of the wax parts. Furthermore, multiple use of the base plate is possible without difficulty. Finally, the inventive apparatus offers the advantage that it can be produced in a time-saving manner.
Pursuant to one preferred embodiment of the inventive apparatus, the tooth arrangement support essentially comprises a U-shaped member that contains magnetic material and is provided with side walls that extend conically toward one another. The base plate has a recess that is complementary to the member, with the surface region of the recess also being provided with magnetic material. This conical member facilitates the precise positioning of the tooth segments relative to the base plate. The conical cross-sectional shape of the member assures that when the segments are removed, only negligibly low frictional forces occur, resulting in the aforementioned advantages.
The member is expediently provided with a shoulder that extends parallel to, or at an acute angle to, the plane of the base plate; this shoulder corresponds to an offset portion in the base plate. Preferably, on the inner wall of the base plate, the offset portion does not extend parallel to the plane of the base plate, but rather extends at a slight angle of 5° to 10° toward the center of the base plate, for example, so that certain tolerances can be more easily compensated for when the tooth arrangement support and the base plate are fitted. In conformity with this slope, the shoulder of the member of the tooth arrangement support must also be slanted. Permanent magnets are preferably inserted in the region of the offset portion of the base plate. These magnets ensure connection with the member, which preferably comprises a synthetic material that is filled with magnetic material.
In order to facilitate positioning of the segments relative to the base plate, and to increase the precision of the fit, ribs are preferably disposed on the conical side walls of the member. These ribs extend parallel to one another, and at right angles to the upper surface of the member. In a similar manner, grooves that are complementary to the ribs are then provided on the walls of the recess in the base plate.
Pursuant to a further preferred embodiment of the present invention, slots or bores are provided on the bottom surface of the base plate; the tooth arrangement support can then be screwed to the base plate from below via the slots or bores. This offers the advantage that various work, especially milling operations, are then possible directly on the tooth arrangement model.
It is particular1y advantageous to embody the magnet that is inserted in the base plate in such a way that it can be removed from below. The magnet can then be held securely in position by screws, a push button type of connection, or a type of bayonet closure, for example. As a result, after this magnet has been removed, the removal of the tooth arrangement segments is particularly simple. Furthermore, in the event that the base plate becomes damaged, the relatively expensive magnet can be removed and placed in another base plate.
It has furthermore proven to be advantageous, during casting or pouring of the root member or tooth arrangement support, to close off the slots or bores on the underside of the base plate by a space retainer, for example of silicon rubber, to thereby make it impossible for the flowable material to escape.
Finally, it is possible to insert on the underside of the base plate, in the central region thereof, a magnet with which the apparatus can be secured to an articulator.
The inventive apparatus is expediently fabricated in various sizes to permit adaptation to the dimensions of the upper and lower jaw.
Further advantageous features of the present invention will be described in detail subsequently.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings in detail, FIG. 1 shows a support 1 for a tooth arrangement. This support 1 essentially comprises an approximately U-shaped member 3, the side walls 4, 5 of which extend conically downwardly toward one another. The side walls 4, 5 are provided with ribs 9 that extend parallel to one another, and substantially at a right angle to the upper surface 13 of the tooth arrangement support 1.
The cross-sectional view of FIG. 2 shows that the tooth arrangement support 1 is provided with a shoulder 7 on the inner side wall 5, so that overall, the support 1 has an approximately L-shaped cross section.
When using the inventive apparatus in practice, the actual tooth arrangement 15, which is obtained by filling the jaw casting or mold, is secured to the support 1. This is expediently effected via laminar adhesion by means of a quick-setting adhesive. The arrangement of the support and tooth arrangement as necessary, then can be divided by vertical saw cuts into segments 19 of individual teeth or groups of teeth.
To produce the tooth arrangement support 1, generally a flowable, curable monomer and/or prepolymer can be used that has little contraction and is filled with a magnetic or magnetizable metal powder.
A U-shaped recess 6 is provided in the base plate 2 of FIG. 1. This recess 6 is complementary to the shape of the member 3, i.e. the side walls of the recess 6 extend conically downwardly toward one another. An offset portion 8 on the inner wall of the recess 6 corresponds to the shoulder 7 of the member 3. Furthermore, the outer walls of the recess 6 are provided with grooves 10 that extend parallel to one another and are disposed substantially at a right angle to the upper surface 16 of the base plate 2. These grooves 10 serve to receive the ribs 9. Thus, there results on the side walls of the member 3 and the recess 6 respective zig-zagged patterns. These complementary patterns facilitate an exactly fitting insertion of the tooth arrangement support 1 into the recess 6. Due to the conical cross-sectional shape of the member 3 and of the recess 6, only very slight frictional forces result when the support 1 is withdrawn from the recess. Connection between the base plate 2 and the member 3, which comprises magnetic material, is assured by flat magnets 12 that are disposed in the region of the offset portion 8.
To produce the inventive apparatus, one starts with a blank for the base plate 2. The recess 6 is provided in the base plate 2 by machining the latter. By using appropriate molds, it would also be possible to produce the base plate in a single operation via injection molding or some similar molding technique.
To produce the tooth arrangement support 1, the aforementioned flowable material is then poured into the recess 6, where it is allowed to cure. Since the pouring or casting process can be repeated as often as desired, a multiple reuse of the base plate is assured. Alternatively, it would also be possible to produce the tooth arrangement support 1 in a separate process, such as by inJection molding or some other precise molding technique. So that the polymerized tooth arrangement support 1 can be easily removed from the base plate 2, the surface of the latter should be as smooth as possible. Examples of materials that can be used for the base plate include plastics and metals. For example, the base plate could be made of polyoxymethylene (Delorin), polyethylene, polypropylene, polyamide resin, acrylic resin (plexiglass), polyvinyl chloride, brass, and aluminum.
One example of an adhesive that would be suitable for adhesively mounting the tooth arrangement on the support 1 is a cyanoacrylate adhesive.
In the embodiment illustrated in FIGS. 3 and 4, the bottom surface 14 of the base plate 2 is provided with slots 11 having a conical cross section. Via these slots 11, the tooth arrangement support 1 can be secured to the base plate 2 from below via screws 17. This makes it possible to have a rigid and fixed connection between the base plate 2 and the tooth arrangement support 1, so that milling work required on individual parts can be carried out directly on the inventive apparatus without it being necessary to remove the individual tooth segments and clamp them separately.
Inserted in the bottom surface 14 of the base plate 2, in the central region thereof, is a magnet 18 with the aid of which the inventive apparatus can be mounted on an articulator.
The following example illustrates one exemplary embodiment of the present invention.
E X A M P L E
25 g fine iron dust (less than 100 μm, average particle size approximately 15 μm) are worked into a homogeneous mixture with 10 g 2,2-bis-[p-(β-hydroxyethoxy)-phenyl]-propane-bis β-ethyleneiminobutyrate (polymerizable prepolymer) and 300 mg 2-ethylhexyl-ethyl-sulfonium-isobutyronitrilefluoroborate (polymerization initiator). As soon as these materials have been mixed together, the very flowable mixture is poured into the recess 6 of a polypropylene base plate 2, where it is allowed to set. The material of the mixture remains flowable for approximately 5 minutes at room temperature, and is set or cured after approximately 15 minutes. After it has set, the finished tooth arrangement support 1 is removed from the base plate 2. The upper surface 13 of the support 1 is laminarly secured with a cyanoacrylate adhesive to a tooth arrangement model 15 made of gypsum or plaster of Paris. The finished arrangement, which comprises the tooth arrangement and the tooth arrangement support, is separated by vertical cuts into individual tooth segments 19 that with the aid of the base plate 2 can easily be combined again to form a complete tooth arrangement model.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. | An apparatus for the fabrication of models of teeth and their arrangement. The apparatus includes an approximately U-shaped tooth arrangement support, and a base plate to which the support is detachably connected. This connection between the tooth arrangement support and the base plate is ensured by magnetic forces. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention claims priority to U.S. Provisional Serial No. 60/306,676, filed on Jul. 20, 2001 and entitled “INTEGRATED TAILGATE AND LOADING RAMPS FOR LIGHT DUTY TRUCKS”.
TECHNICAL FIELD
[0002] This invention relates to systems and methods for loading objects into a pickup truck and wherein the ramps are stored in the tailgate.
BACKGROUND
[0003] Pickup trucks and similar vehicles having truck beds are frequently used to transport objects, such as motorcycles, all terrain vehicles, tractors, mowers, and the like. There has been a continuous effort since the advent of vehicles with truck beds to produce an efficient means of transferring these objects from the ground to the truck bed.
[0004] Early prior art solutions utilized ramps, which were designed to be carried within the truck bed. However, this type of design wasted usable space in the truck bed and added significant weight to the vehicle, thereby reducing the effective load capacity of the truck.
[0005] Another prior art solution to this problem focused on combining the tailgate of the truck and ramps. The complexity in design of combination tailgate and ramp systems has ranged from simple designs consisting of large, cumbersome tailgates that unfold to form a ramp to intricate designs involving telescopic ramps that are housed within a tailgate.
[0006] Other devices disclosed in U.S. Pat. No. 4,003,483, issued to Fulton, U.S. Pat. No. 5,211,437, issued to Gerulf, and U.S. Pat. No. 5,425,564, issued to Thayer, address the load capacity problem by pivoting a panel located in the position of a conventional tailgate about its vertical axis then rotating the panel 90 degrees so the height of the panel rests along the horizontal axis of the assembled configuration. The panel is then lowered to create a surface that runs from the ground to the rear edge of the truck bed. One problem with this design is that the length of the ramp is restricted to the width of the truck bed. Therefore, the ramp is steeply inclined resulting in a higher degree of difficulty in transferring objects to and from the truck bed.
[0007] Other devices, disclosed in U.S. Pat. No. 5,133,584 and U.S. Pat. No. 5,156,432, both issued to McCleary, involve a relatively large apparatus that attaches to the original tailgate and unfolds rearward to form a ramp. While these designs adequately address the issue of ramp length, they are large and rather cumbersome devices that tend to reduce the effective loading capacity of the truck by adding weight to the truck and taking up space in the truck bed.
[0008] Two devices, U.S. Pat. No. 5,273,335, issued to Belnap, and U.S. Pat. No. 5,312,149, issued to Boone, adequately address both the ramp length issue and the loading capacity issue by using telescopic ramps that are stored within the tailgate. To use these devices, the tailgate is lowered to the horizontal position and telescopic ramps are horizontally pulled out of the tailgate. These ramps form a surface that runs from the ground to the truck bed, The devices are contained within the area typically occupied by a conventional tailgate; therefore, the loading capacity of the truck is only marginally affected, if at all. Additionally, the telescopic ramps allow a relatively longer ramp surface, which results in a more gradual ramp incline. However, the telescopic design of the ramps results in a very complex apparatus. Additionally, because these devices are permanently attached to the vehicle, the vehicle's utility is restricted to tasks that can be achieved while the tailgate is in place.
[0009] Therefore, there is a need for an apparatus comprised of long and relatively simply designed ramps and a tailgate capable of housing these ramps so as not to decrease the loading capacity of the truck. Moreover, there is a need for an apparatus that may be easily converted to allow the vehicle to be used in operations that normally require the removal of the tailgate. Finally, the apparatus must maintain a close resemblance to a conventional tailgate, thereby helping to maintain the aesthetic qualities of the vehicle.
SUMMARY
[0010] In a preferred embodiment of the present invention a tailgate and a pair of detachable ramps that can be folded and stored within the tailgate are provided. When housed within the tailgate, the ramps stretch across the width of the tailgate. This configuration allows the ramps to be relatively long, which reduces the degree of inclination of the ramps, with respect to the ground, when the ramps are unfolded and in the loading position.
[0011] In another embodiment of the present invention, the ramps are detachable, thus, increasing the utility of the vehicle.
[0012] Preferably, the ramps may be positioned at various points along the base of the tailgate to accommodate objects of various shapes and sizes.
[0013] In an alternative embodiment, the ramps are removed from the tailgate to allow the vehicle to accommodate a fifth wheel RV without removing the entire tailgate.
[0014] In yet another embodiment, the ramps are removed from the tailgate and replaced by a grate or mesh structure to form an airgate. The replacement of conventional tailgates with airgates is well known in the art.
[0015] In a preferred embodiment, the tailgate is located in the conventional position and uses a conventional latching mechanism.
[0016] In yet another embodiment, the ramps are secured within the tailgate space.
[0017] In still another embodiment of the present invention, a hinged plate and a protruding lip fix the ramps within the tailgate.
[0018] Preferably, when the ramps are stored within the tailgate, the resultant apparatus closely resembles a conventional tailgate.
[0019] In an embodiment of the present invention, the ramps are comprised of two portions, an upper portion and a lower portion. The ramps are configured in a way that allows the lower portion of the ramp to be folded into the upper portion of the ramp. A c-channel is attached to the upper portion of each ramp. When the ramps are unfolded, the c-channel may be attachable to the base of the tailgate to form sturdy, gradually inclining ramps. The ramps may be positioned anywhere along the base of the tailgate, which allows the ramps to be used to easily load and unload objects of various shapes and sizes.
[0020] In yet another embodiment of the present invention, the invention may be easily configured to accommodate a fifth wheel RV. By removing both ramps, a large portion of the tailgate is open, which allows sufficient room for a fifth wheel RV to be hitched to the vehicle.
[0021] In yet another embodiment, the ramps may be removed and replaced by a grate or mesh structure, thereby improving gas mileage.
[0022] These and other aspects and advantages of the present invention will become apparent upon reading the following detailed description of the invention in combination with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0023] [0023]FIG. 1 a is a rear view of a vehicle illustrating an apparatus shown in a closed and vertical position with two ramps, in accordance with the present invention;
[0024] [0024]FIG. 1 b is a rear view of a vehicle illustrating an apparatus shown in a closed and vertical position with one ramp, in accordance with the present invention;
[0025] [0025]FIG. 2 is a rear view of a vehicle illustrating an apparatus shown in a closed and vertical position with one ramp removed, in accordance with the present invention;
[0026] [0026]FIG. 3 is a rear view of a vehicle illustrating an apparatus shown in an open and horizontal position, in accordance with the present invention; FIG. 4 is a schematic illustration of a latching mechanism, in accordance with the present invention;
[0027] [0027]FIGS. 5 and 6 are perspective views of an apparatus shown in an open and horizontal position with ramps removed, in accordance with the present invention;
[0028] [0028]FIG. 7 is a perspective view of an apparatus shown in an open and horizontal position with ramps stored in a tailgate housing, in accordance with the present invention;
[0029] [0029]FIG. 8 is a rear view of a vehicle illustrating an apparatus shown in a closed and vertical position with ramps removed, in accordance with the present invention;
[0030] [0030]FIG. 9 is a rear view of a vehicle illustrating an apparatus shown in an open and horizontal position with ramps being attached to the apparatus to form an inclined surface extending from a ground surface to a truckbed of the vehicle, in accordance with the present invention;
[0031] [0031]FIG. 10 is a perspective view of a vehicle illustrating an apparatus shown in an open and horizontal position with ramps being attached to the apparatus to form an inclined surface extending from a ground surface to a truckbed of the vehicle, in accordance with the present invention;
[0032] [0032]FIGS. 11 and 12 are bottom views of a ramp in an unfolded position, in accordance with the present invention;
[0033] [0033]FIG. 13 is a side view of a ramp in a folded position, in accordance with the present invention;
[0034] [0034]FIG. 14 is a perspective view of a hinged portion of a ramp, in accordance with the present invention; and
[0035] [0035]FIG. 15 is a rear view of a vehicle illustrating an apparatus shown in a closed and vertical position with a grate or mesh structure instead of a ramp inserted in the tailgate housing, in accordance with the present invention.
DETAILED DESCRIPTION
[0036] Referring now to FIG. 1 a, an apparatus 20 is illustrated, in accordance with the present invention. Apparatus 20 includes a housing 22 and generally two ramps 24 and 26 . Alternatively, as shown in FIG. 1 b, one ramp 25 may be used. The apparatus 20 is convertible from a tailgate to a ramp by simply lowering apparatus 20 into a horizontal position, removing ramps 24 and 26 from housing 22 , unfolding ramps 24 and 26 , and attaching the upper ends of ramps 24 and 26 to housing 22 . This creates an inclined surface extending from the ground to a truckbed of a vehicle.
[0037] In FIGS. 2 - 3 , apparatus 20 is shown pivotally attached to a vehicle. Housing 22 , as shown, has a housing base 28 , side portions 30 and 30 ′, retainers 32 and 32 ′, and a ramp-housing receptacle 38 . The function of the housing base 28 is to support ramps 24 and 26 both when ramps 24 and 26 are stored in the housing, as shown in FIG. 1, and when ramps 24 and 26 are being used as ramps (shown in FIGS. 9 and 10).
[0038] In addition to providing support for ramps 24 and 26 , housing base 28 includes retainer latch mechanisms 40 and 40 ′ for securing retainers 32 and 32 ′, which, in turn, secure ramps 24 and 26 within receptacle 38 . Latch mechanisms 40 and 40 ′ are substantially identical, and are located at opposite sides 27 and 29 of housing base 28 . As shown schematically in FIG. 4, latch mechanism 40 ′ includes a latch lever 42 ′ and a latching rod 44 ′. Latch mechanism 40 ′ is of the type conventionally used in residential or commercial doors. Plate 32 ′ may be secured in a closed position by activating lever 42 ′ causing rod 44 ′ to penetrate an eyelet 36 ′ in retainer 32 ′.
[0039] Housing base 28 and latch mechanisms 40 and 40 ′, like the rest of housing 22 , are preferably constructed from steel to maximize strength and durability. Alternatively, any other suitable material, such as aluminum, plastic, fiberglass, metal alloys, or composites, may be used to construct housing base 28 and latch mechanisms 40 and 40 ′, or any other parts of housing 22 .
[0040] With reference to FIGS. 5 and 6, side portions 30 and 30 ′ of housing 22 having surfaces 55 and 55 ′ are illustrated. Extending inward from surfaces 55 and 55 ′ is an outer edge lip 50 and 50 ′, an upper edge lip 52 and 52 ′, and an inner edge lip 54 and 54 ′, which secure ramps 24 and 26 within receptacle 38 of housing 22 .
[0041] As shown in FIG. 7, a pair of tailgate latches 46 and 46 ′ are attached to side portions 30 and 30 ′ for securing housing 22 in a closed vertical position. Apparatus 20 is placed in the closed position by pushing housing 22 into a vertical position causing latches 46 and 46 ′ to engage locking brackets 51 and 51 ′ (shown in FIG. 3) on the vehicle. Latches 46 and 46 ′ may be disengaged by pulling a tailgate latch lever 48 , which is preferably coupled to latches 46 and 46 ′ by a cable and/or mechanical linkages in a conventional manner. Lever 48 is preferably located on side portion 30 ′, as shown in FIG. 1. Alternatively, lever 48 may be located at any other suitable location on housing 22 . Tailgate latches 46 and 46 ′ discussed above may be conventional tailgate latch items that are known in the art.
[0042] Support members 47 and 47 ′ are provided for supporting apparatus 20 when in a horizontal position. Support members 47 and 47 ′ are fixed at one end to housing 22 and at the other end to the vehicle.
[0043] Retainers 32 and 32 ′, as illustrated in FIG. 7, function to secure ramps 24 and 26 when ramps 24 and 26 are stored within receptacle 38 of housing 22 . Retainers 32 and 32 ′ are mirror images of one another, and are placed on opposite ends of housing 22 . Plates 32 and 32 ′ are attached to side portions 30 and 30 ′ by hinges 34 and 34 ′. Hinges 34 and 34 ′ allow plates 32 and 32 ′ to pivot about edges 49 and 49 ′ of plates 32 and 32 ′, respectively, which allows ramps 24 and 26 to be inserted and removed from receptacle 38 of housing 22 or secured within receptacle 38 of housing 22 . As discussed above, plates 32 and 32 ′ contain eyelets 36 and 36 ′, which act to secure plates 32 and 32 ′ in a closed position, as shown in FIG. 7, when latch mechanisms 40 and 40 ′ are activated.
[0044] As shown in FIG. 8, receptacle 38 is defined by a top surface of housing base 28 and sides 53 and 53 ′ of side portions 30 and 30 ′. The function of receptacle 38 is to allow for storage of ramps 24 and 26 within housing 22 . Ramps 24 and 26 rest within receptacle 38 when stored in housing 22 , as shown in FIG. 1. Receptacle 38 is preferably configured to hold two ramps. Alternatively, receptacle 38 may be configured to hold more or less than two ramps.
[0045] As illustrated in FIGS. 9 and 10, ramps 24 and 26 provide an inclined surface for objects to be rolled or dragged onto the truckbed of the vehicle. Preferably, ramps 24 and 26 are identical. Ramps 24 and 26 each have two main sections, an upper ramp section 56 and 56 ′ and a lower ramp section 58 and 58 ′.
[0046] Referring to FIG. 11, upper ramp section 56 includes a surface plate 66 , a middle beam 60 , side frames 70 and 72 , and a c-channel 76 . Upper ramp section 56 is connected to the lower ramp section 58 by a hinge pin 74 .
[0047] Lower ramp section 58 , as illustrated in FIG. 12, includes a surface plate 68 and side beams 62 and 64 . Ramp 24 or 26 , as shown in FIG. 12, is designed in such a way that middle beam 60 of upper ramp section 56 and side beams 62 and 64 of lower ramp section 58 overlap, thereby forming a hinge when secured by hinge pin 74 , which runs through the width of the middle and side beams. Hinge pin 74 allows ramp 24 or 26 to be unfolded, as seen in FIGS. 11 and 12, and folded, as seen in FIG. 13.
[0048] As illustrated in FIG. 13, when the ramps 24 and 26 are folded the side beams 62 and 64 lie between the middle beam 60 and the side frames 70 and 72 , respectively. This configuration minimizes the width of ramps 24 and 26 and allows ramps 24 and 26 to fit within receptacle 38 , as shown in FIG. 1.
[0049] As shown in FIG. 14, the hinged ends of beams 62 and 64 are rounded to enable ramp 24 or 26 to be folded and unfolded without surface plate 66 impeding the rotation of side beams 62 and 64 . Ramps 24 and 26 are equipped with a stabilizing pin 78 and a stabilizing slot 80 . When the ramps are unfolded, pin 78 fits into slot 80 . This configuration allows pin 78 to bear some of the load, which increases the strength and stability of the ramps.
[0050] Ramps 24 and 26 are preferably constructed from aluminum to minimize weight. Alternatively, ramps 24 and 26 may be constructed from any suitable material, such as steel, plastic, fiberglass, metal alloys, or composites.
[0051] Thus, the present invention provides an apparatus 20 , which is easily converted from a tailgate to a ramp. In operation, housing 22 is lowered into a horizontal position, as shown in FIG. 3. Retainers 32 and 32 ′ are then opened by disengaging latch mechanisms 40 and 40 ′ located within housing base 28 and pivoting retainers 32 and 32 ′ about the edges 49 and 49 ′, respectively, to an open position, as shown in FIGS. 5 and 6. Ramps 24 and 26 are then removed by lifting the ramp 24 or 26 nearest housing base 28 out of receptacle 38 , then sliding the remaining ramp 24 or 26 toward housing base 28 and lifting that ramp out of receptacle 38 . Ramps 24 and 26 are unfolded after they have been removed from receptacle 38 . C-channels 76 and 76 ′ of ramps 24 and 26 , which are integral with a top edge of each of upper ramp sections 56 and 56 ′, may then be connected to housing base 28 to form a ramp, as shown in FIGS. 9 and 10. This procedure may be reversed to convert the apparatus 20 from a ramp to a tailgate.
[0052] In FIG. 15, housing 22 is utilized for purposes other than storing ramps 24 and 26 . A grate or mesh 82 is a lattice structure. Grate or mesh 82 can be constructed of steel, aluminum, plastic, fiberglass, metal alloys, or any other suitable materials. The dimensions of grate or mesh 82 are similar to ramps 24 and 26 when the ramps 24 and 26 are folded and in their storage position. Grate or mesh 82 is placed inside of housing 22 in the same fashion that ramps 24 and 26 are stored inside housing 22 . By placing grate or mesh 82 inside of receptacle 38 , an airgate is formed. This configuration allows the vehicle to achieve better gas mileage. Additionally, the grate or mesh 82 or either one or both of ramps 24 and 26 may be removed to provide sufficient space for a fifth wheel RV to be attached to the vehicle. This enables a fifth wheel RV to be hitched to the vehicle without having to remove the entire tailgate.
[0053] The present invention provides many advantages and benefits over the prior art. Ramps 24 and 26 are constructed in such a way to allow the ramps to be folded and stored within housing 22 of apparatus 20 . This results in an apparatus 20 that occupies no truckbed space in excess of that of a conventional tailgate. In addition, the decrease in the loading capacity of the vehicle, as a result of the implementation of apparatus 20 , is negligible.
[0054] As any person skilled in the art of systems and methods for loading objects into a vehicle will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the preferred embodiments of the invention without departing from the scope of this invention defined in the following claims. | An apparatus is provided for closing a vehicle storage compartment. The apparatus includes: a housing which resembles a tailgate of a vehicle and wherein the housing has one or more loading surfaces. The loading surfaces can be removed from the tailgate, placed into a loading position and used for loading items into or out of a vehicle storage compartment. Thereafter, the loading surfaces may be transformed into a storage position and placed within the housing. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The invention relates to a cylinder head of an internal combustion engine, with a coolant space associated with each combustion chamber of the cylinderhead and with at least one coolant inlet and at least one coolant outlet.
2. Description of Related Art.
A coolant arrangement for a multi-cylinder internal combustion engine is disclosed in German DE 195 42 492 C1. In this coolant arrangement, a coolant space includes a plurality of coolant space areas provided for a combustion chamber of the engine. The coolant space is defined between the base of the cylinder head, the outer walls, and the top of the cylinder head. The coolant space areas are supplied with coolant through inlets in communication with the coolant jacket of the engine block. The individual coolant space sections are flow connected in series with the coolant jacket of the cylinders and thus cannot be individually subjected to different flow patterns or be supplied with coolant differently.
SUMMARY OF THE INVENTION
The object of the invention is to provide a coolant housing with individual coolant spaces in a manner so that each individual coolant space or section can be subjected to a different flow or can be supplied separately with coolant to a different degree. Thus, coolant can be supplied separately to critical regions for individual cylinders.
The object is achieved by including providing in the cylinderhead at least a first coolant chamber and at least a second coolant chamber, which are separate from one another. The coolant outlet of the second coolant chamber is in communication with the first coolant chamber. This permits directing coolant flow inside the coolant spaces in an optimized manner to specifically cool critical (hot) regions, such as the center of the combustion chamber and the area adjacent the exhaust valve(s).
It is furthermore possible to arrange the coolant inlet of the second coolant chamber exterior to the coolant housing and to provide for a coolant outlet of the second coolant chamber in the coolant space of the cylinderhead.
Furthermore, it has been found that it is desirable that the coolant outlet of the second coolant chamber be designed as a coolant flow passage arranged near an exhaust valve. The design of the coolant outlet as a transverse flow passage subjects the critical (hot) region near the exhaust valve and the combustion chamber to coolant flow providing for specific cooling in these critical regions.
To this end, it is also advantageous that the coolant inlet and outlet of the first coolant chamber of the coolant housing are positioned exteriorly to the coolant housing. The two coolant chambers or the coolant space can therefore be subjected to different flow patterns in different areas of the cylinderhead for cooling them in a specific manner.
Finally, in a preferred embodiment of the invention, provision is made for the coolant inlet to be in communication with both the first and the second coolant chamber. In this way, both coolant chambers are jointly supplied with coolant.
Therefore, the coolant chambers of the cylinder head are entirely separate from the coolant spaces of the engine block.
In the manufacture of the subject cylinderhead with coolant spaces, sand cores are configured in accordance with the shape of the coolant spaces. This design does not require additional bores or machining steps for the forming of the coolant spaces. Accordingly, a cylinderhead with cooling chambers as provided by this invention are substantially more cost-effective from a casting point of view.
Of particular importance for the present invention is the use of an external valve at the inlet of the first and second coolant chambers. By means of the valve, the coolant space can be supplied with separate or individualized flows in accordance with the desired cooling capacity.
In connection with the design and arrangement of the subject invention, it is of advantage if the top of the first coolant chamber is disposed approximately level with the top of the combustion chamber.
Furthermore, it is advantageous to locate the second coolant chamber near an outer end of the first coolant chamber and near the exhaust side of the cylinderhead. This permits additional coolant flow to be supplied near this critical hot exhaust side.
In addition, it is advantageous to provide flow conducting or flow directing elements for the coolant to ensure an optimized flow pattern inside the cooling chambers.
Furthermore, it is advantageous for the first and the second cooling chambers of a combustion chamber to have a common coolant inlet. Then, depending on the particular requirements of an internal combustion engine, individual coolant chambers may be supplied with individual coolant flows or with a combined flow. Also, the coolant outlet of the second coolant chamber should conduct coolant past the combustion chamber top portion and past the center of the combustion chamber.
For simplification, the coolant spaces of any two adjacent combustion chamber areas should have a common coolant inlet and a common coolant outlet.
Advantages and details of the invention are illustrated in the following drawings and described in the following detailed description on the basis of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a coolant housing area defining coolant spaces;
FIG. 2 is a schematic top planar view of the coolant spaces formed in the cylinderhead; and
FIG. 3 shows a sectional representation of the coolant housing defining coolant spaces taken along section line A—A in FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, a coolant space 1 for a cylinder head (not shown in the drawing) of a multi-cylinder internal combustion engine is shown. The coolant space 1 consists of a first coolant chamber 2 and a second coolant chamber 3 , both chambers being part of a coolant housing 7 . What is shown in FIGS. 1 and 2 are actually the coolant spaces or, when filled with coolant, the coolant bodies in the cylinderhead. These coolant spaces as shown in FIG. 3 include over each cylinderhead first and second coolant chambers 2 and 3 , which have about the same height.
The first coolant chamber 2 and the second coolant chamber 3 have a common coolant inlet 4 . A branch passage 15 beginning just after entry into the coolant housing 7 supplies coolant to the first coolant chamber 2 and the second coolant chamber 3 .
The coolant inlet 4 is designed as an external inlet, i.e. it opens to the outside of the coolant housing, that is, the cylinderhead. In this case, coolant is not supplied to the cylinder head's cooling circuit through the conventional openings in the base of the cylinder head but instead, via an external inlet 4 formed in the cylinder head. A coolant valve 4 a assigned to at least one of the inlet lines 4 ′ leading to the external coolant inlets 4 . The valve provides a simple control of coolant flow into the respective coolant spaces associated with specific cylinders.
The second coolant chamber 3 is disposed over the top side 16 of the first coolant chamber and is provided with a coolant passage 6 which serves as a coolant outlet. Coolant flows transversely through the second coolant chamber 3 and leaves via the coolant passage 6 , which is arranged adjacent the region of aperture 10 defining an exhaust passage. This provides for precise cooling of the critical region adjacent the exhaust valve or around the exhaust passage and at the top of the combustion chamber.
As seen in FIG. 2, the second coolant chamber 3 of the coolant space 1 is located above the first coolant chamber 2 in the exhaust side region. Apart from the coolant passage 6 and the coolant inlet 4 , the second coolant chamber 3 has no further fluid connection to the first coolant chamber 2 . Importantly for the second coolant chamber 3 , it conducts coolant about and around the exhaust valve aperture 10 provided for an exhaust valve (not shown).
The first coolant chamber 2 of the coolant space 1 has a coolant outlet 5 designed as a coolant passage with coolant flowing longitudinally through it. Various apertures 9 , 10 , 11 , 12 , 13 are provided respectively: for an outlet for exhaust gas; an exhaust valve; a spark plug; a fuel injector; and an inlet valve. The coolant flows around the walls defining these apertures before it leaves the coolant chamber via the coolant outlet 5 .
The coolant outlet 5 is an external coolant outlet, i.e. it opens externally of the coolant housing 7 . It is in communication with the inlet of the engine's coolant pump via conduits or lines (not shown).
In addition to the coolant inlet 4 , the second coolant chamber's coolant passage 6 conducts coolant also to the first coolant chamber 2 .
As best understood by referring to FIG. 3, two coolant spaces 1 are associated with two adjacent cylinders or combustion chambers. The two coolant spaces form a pair for the two cylinders or pairs of coolant spaces for various even numbers of cylinders, which are arranged side by side in a cylinderhead 7 . Two adjacent coolant spaces 1 of a coolant-space pair are connected via a common coolant inlet 4 and a common coolant outlet 5 but there is no flow connection between the adjacent pairs of coolant spaces. Each cylinder pair or each coolant-space pair is therefore cooled and subjected to a separate coolant flow pattern.
FIG. 1 shows that the first coolant chamber 2 and the second coolant chamber 3 of the coolant space 1 are arranged separately from one another, and only the common coolant inlet 4 and the coolant passage 6 provide for communication between the two chambers.
FIG. 2 shows the coolant space 1 with the various apertures 9 , 11 , 12 , 13 respectively, for the exhaust gas outlet (and exhaust valve), the spark plugs, the fuel injector, and the intake air to the combustion chamber (and intake valve).
FIG. 3 shows, in a top view, the coolant housing 7 including walls 17 , an inlet flange 19 for a coolant-space pair, and a timing chain housing 18 .
FIGS. 1 and 2 only show the coolant space 1 , FIG. 3 shows the cylinderhead with the coolant chamber 2 in a section taken along line A—A of FIG. 1 . The walls 17 of the cylinderhead structure 7 form the coolant space 1 .
In this representation of the invention, the first coolant chamber 2 is sectioned along line A—A in FIG. 1 . The common coolant inlet 4 supplies two coolant spaces 1 for two adjacent cylinders. Coolant from the first and second coolant chambers 2 , 3 flows out via the coolant outlet 5 . Exhaust passages 9 ′ for exhaust gas, inlet passages 13 ′ for the engine charge air, and openings 11 ′ for receiving spark plugs and also an opening 12 ′ for receiving a fuel injector are provided.
Within the coolant chamber 2 , a curved flow guide element 8 is provided adjacent the exhaust passage 9 ′ or, respectively, disposed with one end adjacent the exhaust passage 9 ′. | In an internal combustion engine, with a cylinder head having a coolant space associated with each combustion chamber, wherein the coolant space comprises, for each cylinder of the engine, a first coolant chamber and a second coolant chamber separate from one another, the coolant space has a coolant inlet which extends to the outside and is connected to a coolant supply line for directly supplying coolant from the outside to the first and second coolant chambers. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 13/056,429, filed Jul. 11, 2011, which is a U.S. National Phase of International Patent Application PCT/CA2010/001545, filed Sep. 28, 2010, which claims priority to U.S. Provisional Patent Application No. 61/247,194, filed Sep. 30, 2009, each of which is incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The invention relates generally to a fabric care device.
BACKGROUND OF THE INVENTION
After use and wear, unsightly pills, which are small balls of fibres, or the like can form on the surfaces of some fabrics. Other unwanted material on the fabric surfaces may include lint, dust and loose fibres or hair. Many devices exist to remove these unwanted material from fabric surfaces including powered devices which operate in a similar fashion to electric shavers. However, these powered devices tend to be complicated, inefficient, bulky, cumbersome and expensive, and require a power input necessitating either a plug or batteries which adds to their cost and makes them impractical.
Many non-powered (manual) depilling devices exist which typically comprise a strip of abrasive material or a cutting surface mounted to a support such as a comb, as described and illustrated for example in U.S. Pat. No. 2,934,810, U.S. Pat. No. 3,471,977, U.S. Pat. No. 4,686,731, U.S. Pat. No. 5,036,561, U.S. Pat. No. 5,575,031 and U.S. Design 389,619. A user can grasp such devices by the support and pass the abrasive or cutting surface over the piece of fabric to detach the pills from the fabric. Some of the detached pills will be retained on the abrasive or cutting surface thereby removing them from the fabric surface.
Additional features may be provided for removing the loose material from the fabric surface. For example, the device of U.S. Pat. No. 5,575,031 provides notches in which the detached pills are collected, and the device of U.S. Pat. No. 5,036,561 provides a second delinting surface to collect the loose material. Delinting surfaces typically comprise a tacky/sticky material to which the loose material adheres such as adhesive paper, or a fabric with a slant, hook or loop pile mounted to a support for picking up lint and other loose pieces of unwanted material from the fabric surface. However, these devices tend to be awkward to handle and are limited to depilling and delinting operations only.
Therefore, it is desired to overcome or reduce at least some of the above-described problems.
SUMMARY OF THE INVENTION
The present invention reduces the difficulties and disadvantages of the aforesaid devices. From one aspect, there is provided a fabric care device comprising a body or frame having first and second ends for attaching respective first and second fabric care attachments, wherein at least one of the first and second ends is adapted to detachably attach at least one of the first and second fabric care attachments.
Advantageously, the fabric care attachment which is detachably attachable can be attached when needed and detached when not needed. It can be replaced when worn or old. It can also be replaced by a different type of fabric care attachment e.g. having a different use. For example, in one embodiment, the fabric care device is provided with three types of depillers detachably attachable to one of the first or second ends to treat a range of different fabrics such as natural, synthetic and fabric blends. The different depillers have different treatment surfaces such as different grades of roughness.
Preferably, the fabric care device comprises a handle separating the first and second ends. The handle can be a portion of the body and be integral with the body. The handle can have an overmoulded portion. The overmoulded portion may be made of a rubbery material to improve the user's grip on the handle. Preferably, the handle is ergonomically shaped. The first and second ends can be oppositely facing one another so that a user can use the first and second fabric care attachments without significantly changing their grip on the handle. Also, the fabric care device can be used single handedly by a user.
The fabric care device can further comprise at least one fabric care attachment selected from the group consisting of a depiller, a delinter, a fabric pile restorer, and a brush. The fabric pile restorer can be a metal brush such as pet brush or a brush having aluminium or brass bristles such as for grooming velvet and other materials. The brush can be an electrostatic brush. Other fabric care attachments are possible.
In one embodiment, the fabric care device comprises a depiller detachably attachable to the first end and a delinter attached to the second end. In this embodiment, the delinter is integral with the body or is attached to the body. Preferably, the depiller has a silicon carbide surface and the delinter has a simulated velvet surface. In one embodiment, the silicon carbide surface is a type of ‘sandpaper’ and can have a grit of about 40 to about 1200, or any other suitable grit size, for removing a variety of sizes of pills. In a preferred embodiment, a silicon carbide paper grit of 400 is used. Any other type of abrasive surface can also be used as the depiller. For example, an aluminium oxide grid or paper having a suitable grit size can also be used.
In another embodiment, the fabric care device comprises first and second fabric care attachments which are detachably attachable to the first and second ends, the first and second fabric care attachments being selected from the group consisting of a depiller, a delinter, a fabric pile restorer, and a brush. The depiller can be used to detach pills from the surfaces of fabrics and other materials. The delinter can be used to remove pills and other debris from the fabric and material surfaces. The fabric pile restorer is preferably a brush which is used to brush a fabric to restore its pile. In one embodiment, the pile restorer is a metal brush, i.e. a brush with metallic bristles, which is used to restore the pile of fleecy and other types of materials.
The fabric care device may further comprise different types of depillers, delinters, fabric pile restorers or brushes, wherein each of the types of depillers, delinters, fabric pile restorers or brushes are interchangeable. For example, a user may detachably attach one type of depiller for removing the pills of one fabric type to the fabric care device and replace this with another type of depiller for another fabric type when needed. In this way, a user may treat or maintain a wide range of fabrics and materials with the fabric care device and attachments. The use of the fabric care device can therefore be extended to many uses including pet care and upholstery care. Therefore, the term ‘fabric’ should be interpreted as including material, fur and any other surface from which debris is required to be removed.
Preferably, the depiller comprises an abrasive or cutting surface selected from the group comprising surfaces including silicon carbide and aluminium oxide, and a blade. The blade can be metallic. The delinter may comprise a delinting surface for retaining loose material, the delinting surface being selected from the group consisting of a fabric with a slant, a simulated velvet, a sticky or tacky surface, an electrostatic brush, and a hook or loop pile material. The fabric care device may further comprise a first attachment mechanism for detachably attaching the fabric care attachment to the first and/or second ends. Preferably, the first attachment mechanism comprises a portion on the first or second end of the fabric care device which is engageable with a corresponding portion on the fabric care attachment. In other words, the ends of the fabric care device and the fabric care attachments are interengageable.
In one embodiment, the first attachment mechanism is a screw lock and the portion on the first or second end of the fabric care device is a radial protrusion or opening. In another embodiment, the first attachment mechanism is a hook lock and the portion on the first or second end of the fabric care device comprises a resiliently biased pair of hooks which are receivable into corresponding indents in the fabric care attachment. The fabric care device further comprises a button for moving the pair of hooks towards and away from one another to release and retain the fabric care attachment. The button can be provided on the handle. The button may protrude from the surface of the handle. The button may be adjacent or proximate a thumb rest provided on the handle.
According to another aspect, there is provided a fabric care device comprising a body having first and second ends, a first fabric care attachment (or accessory) which can be attached and detached (‘detachably attachable’) to the first end, and a second fabric care attachment fixed (‘attached’) to the second end. Preferably, the first fabric care attachment is a depiller comprising an abrasive or cutting surface selected from the group consisting of silicon carbide paper, an aluminium oxide grid, and a blade. Preferably, the second fabric care attachment is a delinter comprising a delinting surface for retaining loose material, the delinting surface being selected from the group consisting of a fabric o with a slant, a simulated velvet, a sticky or tacky surface, an electrostatic brush, and a hook or loop pile material.
The fabric care device may further comprise different depiller types which are interchangeable with one another.
Advantageously, the fabric care device further comprises a handle separating the first and second ends. The handle may be a portion of the body and may be integral with the body. The handle may have an overmoulded portion, for example for improving the user's grip on the handle. Preferably, the handle is ergonomic. Preferably, the first and second ends are oppositely facing one another.
The fabric care device can further comprise a first attachment mechanism for detachably attaching the first fabric care attachment to the first end. The first attachment mechanism can comprise a portion on the first or second end of the fabric care device which is engageable with a corresponding portion on the fabric care attachment. The first attachment mechanism can be a hook lock and the portion on the first or second end of the fabric care device can comprise a resiliently biased pair of hooks which are receivable into corresponding indents in the first fabric care attachment. A button or other means may be provided on the fabric care device for moving the pair of hooks towards and away from one another to release and retain the first fabric care attachment.
From yet another aspect, there is provided a fabric care device comprising a depilling surface which is silicon carbide paper. In one embodiment, the silicon carbide surface is a type of ‘sandpaper’ and can have a grit of about 40 to about 1200 for removing a variety of sizes of pills. In a preferred embodiment, a silicon carbide paper grit of 400 is used. In another embodiment, aluminium oxide paper is used having a grit of about 40 to about 1200 for removing a variety of sizes of pills.
From a further aspect, there is provided use of silicon carbide as a depilling surface for a fabric care device. In one embodiment, the silicon carbide surface is a type of ‘sandpaper’ and can have a grit of about 40 to about 1200 for removing a variety of sizes of pills. In a preferred embodiment, a silicon carbide paper grit of 400 is used.
From a yet further aspect, there is provided a depilling attachment for a fabric care device, the depilling attachment comprising silicon carbide paper as a depilling surface. Preferably, the depilling attachment is detachably attachable to the fabric care device. In one embodiment, the silicon carbide surface is a type of ‘sandpaper’ and can have a grit of about 40 to about 1200 for removing a variety of sizes of pills. In a preferred embodiment, a silicon carbide paper grit of 400 is used.
From another aspect, there is provided a delinting attachment for a fabric care device, the delinting attachment comprising a delinting surface selected from the group comprising a fabric with a slant, a simulated velvet, a sticky or tacky surface, an electrostatic brush, and a hook or loop pile material. Preferably, the delinting attachment is detachably attachable to the fabric care device. The simulated velvet can be a looped-weave polyester.
From a further aspect, there is provided a fabric care attachment for a fabric care device, the fabric care attachment comprising a metal brush for restoring pile on fleecy materials.
Preferably, the fabric care attachment is detachably attachable to the fabric care device. From a yet further aspect, there is provided an attachment for a fabric care device selected from the group consisting of a depiller, a delinter, a fabric pile restorer, and a brush. The depiller is an abrasive or cutting surface selected from the group consisting of silicon carbide, aluminium oxide, and a blade. The delinter comprises a delinting surface for retaining loose material, the delinting surface being selected from the group consisting of a fabric with a slant, a simulated velvet, a sticky or tacky surface, an electrostatic brush, and a hook or loop pile material. The fabric pile restorer is a brush, preferably a metal brush.
It will be appreciated that embodiments of the present invention address some of the most common fabric care issues: detaching pills from fabric surfaces and removing the detached pills and other loose material from the fabric surfaces. By pills it is meant any type of unwanted material on a fabric or other material surface which can include knots and other debris on fur or hair.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following drawings in which:
FIG. 1 is a top perspective view from a first end of a fabric care device according to an embodiment of the present invention;
FIG. 2 is a top perspective view from a second end of the fabric care device of FIG. 1 ;
FIG. 3 is a bottom perspective view of the fabric care device of FIG. 1 ;
FIG. 4 is a first end view of the fabric care device of FIG. 1 ;
FIG. 5 is a second end view of the fabric care device of FIG. 1 ;
FIG. 6 is a side view of the fabric care device of FIG. 1 ;
FIG. 7 is another side view of the fabric care device of FIG. 1 ;
FIG. 8 is a bottom plan view of the fabric care device of FIG. 1 ;
FIG. 9 is a top plan view of the fabric care device of FIG. 1 ;
FIG. 10 is a top perspective view of the fabric care device of FIG. 1 with a first and a second fabric care attachment detachably attached to a first and a second end of the fabric care device, respectively, according to another embodiment of the invention;
FIG. 11 is a top perspective view from the second end of the fabric care device and attachments of FIG. 10 ;
FIG. 12 is a bottom perspective view of the fabric care device and attachments of FIG. 10 ;
FIG. 13 is a first end view of the fabric care device and attachments of FIG. 10 ;
FIG. 14 is a second end view of the fabric care device and attachments of FIG. 10 ;
FIG. 15 is a side view of the fabric care device and attachments of FIG. 10 ;
FIG. 16 is another side view of the fabric care device and attachments of FIG. 10 ;
FIG. 17 is a top plan view of the fabric care device and attachments of FIG. 10 ;
FIG. 18 is a bottom plan view of the fabric care device and attachments of FIG. 10 ;
FIG. 19 is an exploded view of the fabric care device and attachments of FIG. 10 ;
FIG. 20 is a top perspective view of the first fabric care attachment of FIG. 10 according to another aspect of the invention;
FIG. 21 is bottom perspective view of the first fabric care attachment of FIG. 20 ;
FIG. 22 is a side view of the first fabric care attachment of FIG. 20 ;
FIG. 23 is a bottom plan view of the first fabric care attachment of FIG. 20 ;
FIG. 24 is a top plan view of the first fabric care attachment of FIG. 20 ;
FIG. 25 is an end view of the first fabric care attachment of FIG. 20 ;
FIG. 26 is a top perspective view of the second fabric care attachment of FIG. 10 according to another embodiment of the invention;
FIG. 27 is a side view of the second fabric care attachment of FIG. 26 ;
FIG. 28 is an end view of the second fabric care attachment of FIG. 27 ;
FIG. 29 is a top plan view of the second fabric care attachment of FIG. 27 ;
FIG. 30 is a bottom plan view of the second fabric care attachment of FIG. 27 ;
FIG. 31 is a bottom perspective view of the second fabric care attachment of FIG. 27 ;
FIG. 32 illustrates an attachment mechanism of the first fabric care attachment of FIG. 10 , according to an embodiment of the invention;
FIGS. 33 ( a ) to ( c ) illustrate the detachment of the first fabric care attachment of FIG. 10 from the fabric care device of FIG. 1 , according to an embodiment of the invention; and
FIGS. 34( a ) to ( c ) illustrate the detachment of the second fabric care attachment of FIG. 10 from the fabric care device of FIG. 1 , according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including”, “comprising”, or “having”, “containing”, “involving” and variations thereof herein, is meant to encompass the items listed thereafter as well as, optionally, additional items. In the following description, the same numerical references refer to similar elements. In the drawings, like reference characters designate like or similar parts.
In accordance with one embodiment of the present invention as illustrated in FIGS. 1 to 9 , there is provided a fabric care device 10 comprising a body 12 having first and second ends 14 , 16 separated by a handle 17 . The handle is a portion of the body and can be integral with the body or attached to the body. The first and second ends 14 , 16 are arranged to detachably attach first and second fabric care attachments 18 , 20 ( FIGS. 10 to 19 ). The fabric care device 10 is a manual, hand held device in that it is intended for manipulation by a user and does not require a power input. The mechanisms of attachment of the first and second attachments to the device are best illustrated in FIGS. 1 to 9 which show the fabric care device 10 without the first and second attachments 18 , 20 , and FIGS. 32 to 34 illustrating the detachment of the fabric care attachments 18 , 20 from the first and second ends 14 , 16 . In the embodiment of FIGS. 10 to 19 , the first fabric care attachment 18 is a depilling tool (a ‘depillen’), as illustrated in further detail in FIGS. 20 to 25 , and the second fabric care attachment 20 is a delinting tool (a ‘delinter’) as illustrated in further detail in FIGS. 26 to 31 .
The handle 17 is elongate and is ergonomically shaped to facilitate a user's comfortable grip. A thumb rest 22 is provided on an upper surface 24 of the device 10 to further enhance a user's grip and ability to manoeuvre the device 10 across a material surface. In this embodiment, the handle 17 is moulded from two different types of material to enhance grip and comfort further still. For example, Santoprene™, a rubber-plastic mixture material, or polyethylene can be used as the overmould material and polypropylene as the core material. Other materials can also be used, as will be evident to those skilled in the art. An indent for a users forefinger may be provided (not shown) on an undersurface of the device 10 .
Referring to FIGS. 20 to 25 , the depilling attachment 18 comprises an elongate body 25 having top and bottom faces 26 , 28 . A depilling surface 30 is provided on the bottom face 28 and a number of protrusions and indents 32 for attaching the depilling attachment 18 to the first end 14 is provided on the top face 26 . The depilling surface 30 comprises any suitable surface which can cut or detach pills from a fabric or material, such as a blade having one or a plurality of teeth, or an abrasive surface. The abrasive surface can be made of silicon carbide, aluminium oxide, crushed diamonds or any other suitable material and can be in the form of a sandpaper or the like. The abrasive surface may be arranged in a pattern such as a grid. The abrasive surface can be attached to the body 25 in a manner known to the person skilled in the art such as a paper wrapped around a pin or a plate.
The fabric care device 10 may be provided with a plurality of interchangeable depilling attachments for use with different materials and different types of fabrics or fibres. For example, there may be provided a depilling attachment 18 having a metal blade with teeth for synthetic materials, and one with a silicon carbide or an alumina grid abrasive surface for natural fibres. It will be appreciated that any other type of abrasive or cutting surface can be used as a depilling surface for the depilling attachment 18 .
In this embodiment, attachment of the depilling attachment 18 to the device 10 is by means of interengaging portions in the first end 14 and in the depilling attachment top face 26 which mechanically connect the two components together, as best seen in FIG. 32 . The first end 14 of the device 10 is provided with a pair of inwardly facing hooks 34 which can be received in corresponding indents 32 in the depilling attachment top face 26 . The hooks 34 are resiliently biased towards each other. The hooks 34 can be moved away from each other by pushing or sliding a button 36 on the top surface 24 of the device 10 to release the hooks 34 from their corresponding indents 32 in the depilling attachment 18 . Conveniently, the button 36 is adjacent the thumb rest 22 so that a user can release the first attachment 18 from the device using only one hand; the same hand holding the handle without changing his or her grip whilst keeping the other hand free to perform another function. Similarly, the depilling attachment 18 is locked into place by sliding the button 36 towards the first end 14 to separate the hooks 34 from each other, inserting the hooks 34 into their corresponding indents 32 in the depilling attachment 18 , and releasing the button 36 . It will be appreciated that the hooks may be part of the first attachment instead of part of the device.
Any other suitable mechanism for attaching, locking and detaching the first attachment 18 to the device 10 is also included within the scope of this invention. For example, the first attachment 18 may be detachably attached to the device 10 by a magnetic or mechanical fixation mechanism (e.g. snap fit mechanism or using screws, nails or the like). Alternatively, the first attachment 18 may be integral with the device 10 either by forming the two components together such as by moulding or by attaching the first attachment to the device by adhesive or the like. In a further alternative embodiment, the first attachment may be moveable relative to the device when attached (detachably or otherwise), e.g. by a pivot, hinge or ball and socket joint. Referring now to FIGS. 26 to 31 , the delinting attachment 20 comprises an elliptical body 40 having top and bottom faces 42 , 44 . The body 40 may be a shape other than elliptical, such as rectangular or square. A delinting surface 46 is provided on the top face 42 , which comprises a surface for picking up loose material when moved across a material, for example a fabric with a slant such as a simulated velvet, a sticky/tacky surface, an electro-static brush, a hook or loop pile, or any other surface for picking up loose material from a surface. The delinting attachment 20 can also be in the form of a delinting roller, having a washable tacky surface or layer(s) of adhesive, detachably attachable to the device second end 16 and rotatable with respect to the second end 16 for ease of loose material collection. The fabric care device 10 may be provided with a plurality of different types of interchangeable delinting attachments 20 for use with different materials and different types of fabrics and fibres.
In this embodiment, attachment of the delinting attachment 20 to the device 10 is by means of a mechanical fit. The bottom face 44 of the delinting attachment 20 has indents and protrusions for engagement with corresponding indents and protrusions on the device second end 16 for attaching the delinting attachment 20 to the device 10 . In this embodiment, the indents on the bottom face 44 of the delinting attachment 20 comprise two slots 48 , arranged radially around a central indent 50 in the bottom face 44 , each slot 48 having one end wider than the other end. In use, corresponding protrusions 52 on the second end 16 of the device 10 are slotted into the wider ends of the slots 48 , and a central protrusion 54 of the device second end 16 is received into the central indent 50 of the delinting attachment 20 . The delinting attachment 20 is rotated or turned about the central protrusion 54 of the device so that the protrusions 52 are received in the narrower portions of the slots 48 to lock the delinting attachment 20 in position on the device 10 (a ‘screw lock’ mechanism). To remove the second attachment 20 from the device 10 , the attachment 20 is rotated relative to the device 10 in a counter direction. It will be appreciated that the bottom face 44 of the delinting attachment 20 may have protrusions instead of, or as well as, indents, and that the second end 16 of the device may have indents instead of, or as well as, protrusions.
Any other suitable mechanism for attaching, locking and detaching the second attachment 20 to the device 10 is also included within the scope of this invention. For example, the second attachment 20 may be detachably attached to the device 10 by a magnetic or mechanical fixation mechanism (e.g. snap fit mechanism or using screws, nails or the like). Alternatively, the second attachment 20 may be integral with the device 10 either by forming the two components together such as by moulding or by attaching the components together by adhesive or a mechanical fixation method or the like. In a further alternative embodiment, the second attachment may be moveable relative to the device when attached, e.g. by a pivot, hinge or ball and socket joint. In an alternative embodiment, the fabric care device 10 and the attachments 18 , 20 can be made from one or two pieces instead of three separate pieces. For example, the device 10 and the first attachment 18 , or the device 10 and the second attachment 20 , or the device 10 and both attachments 18 , 20 , can be a single piece. In one embodiment, the delinting attachment and the device 10 are a single piece.
The fabric care device 10 can be provided with alternative or additional attachments for attachment to the first and/or second ends. One alternative to the delinting attachment is a brush attachment (not shown) having a brushing surface comprising metal teeth (a wire brush), such as those found on pet hair brushes. The metal teeth or bristles may be aluminium or brass or any other type of suitable metal. The inventor has surprisingly found that brushing with this metal brush restores pile on fleece clothing. The brush attachment can also be provided with rubber teeth to remove loose material such as pet hair and fur and other fibres. Advantageously, the rubber brush can be used wet or dry. A lint roller can be provided as an additional or alternative attachment. The lint roller can be washable or may comprise adhesive paper layers. The attachment mechanism of the lint roller to the handle may be arranged to enable the lint roller to pivot with respect to the handle to facilitate delinting an uneven surface, such as clothes which are being worn by the user or upholstery.
In yet another embodiment, the fabric care device 10 can be used as a pet care device. Accordingly, at least one of the attachments may be adapted for this use. For example, the first attachment can comprise a comb or brush suitable for combing or brushing animal fur. A number of comb or brush attachments, which can be detachably attached to the handle, can be provided which are suitable for different types of fur for different pets, e.g. cats and dogs. The second attachment can be a delinting brush or an electrostatic brush.
In use, a user passes the first end 14 with the depilling attachment 18 over a fabric or other surface to detach pills or other debris from the surface. Some of the pills and debris may be retained on the depilling attachment 18 . The remaining loose pills and other loose material on the surface can be removed by passing the second end 16 with the delinting attachment 20 over the surface. Advantageously, as the first and second ends are positioned at either end of the handle 17 , the user need not change his or her grip on the handle 12 in order to depill and then to delint. In other words, the surface can be depilled and delinted with the same operation. Even if any adjustment to the user's grip is required, there is no need for the user to re-orientate the fabric care device 10 unlike existing fabric care devices which combine depillers and delinters.
Advantageously, by means of at least one of the fabric care attachments 18 , 20 being detachable from the handle 12 , they can be replaced when required and interchanged as needed depending on the fabric or material being treated and the treatment required. The fabric care attachments 18 , 20 can be mounted to the fabric care device 10 such that the attachments can perform their function on a fabric without the user of the device having to re-orient the whole device. i.e. the functional surfaces of the attachments face the same direction when mounted to the device 10 . In the case of the depilling and delinting attachments of the first embodiment, the user can separate pills from the surface of a material by passing the delinting attachment end over the material surface. The detached pills can then be removed by passing the delinting attachment end over the material surface to pick up the detached pills and other debris from the material surface. Advantageously, the depilling attachment 18 can be replaced as and when required.
It should be appreciated that the invention is not limited to the particular embodiments described and illustrated but includes all modifications and variations falling within the scope of the invention as defined in the appended claims. For example, the first and second fabric care attachments can be connected to the first and second ends by magnets, a combination of magnets and mechanical fixation, or any other suitable fixation system. The fabric care device can be adapted for other applications, for example as a pet brush (as described above) or an upholstery tool. Therefore, the term fabric should be construed to mean any type of surface from which loose material is desired to be removed. | A fabric care device comprising a body having first and second ends for attaching respective first and second fabric care attachments, wherein at least one of the first and second ends is adapted to detachably attach one of the first and second fabric care attachments. An attachment for a fabric care device selected from the group consisting of a depiller, a delinter, a fabric pile restorer, and a brush. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present invention is related to U.S. patent application Ser. Nos. 09/163,893, 09/164,124, 09/164,250, 09/163,808, 09/163,765, 09/163,839, 09/163,954, 09/163,924, 09/163,904, 09/163,799, 09/163,664, 09/164,104, 09/163,825, issued U.S. Pat. Nos. 5,717,986, 5,893,015, 5,968,674, and 5,853,906, and U.S. patent application Ser. No. 09/128,160, each of the above being incorporated herein by reference.
BACKGROUND
The present invention relates to the field of overcoat materials, and more specifically relates to overcoat materials functioning as relaxation coatings applied to electrode grids.
There are known or proposed systems for electrostatically moving or assisting with the movement of fine particulate materials, such as marking material (e.g., toner) and the like. One such system is described in U.S. patent application Ser. No. 09/163,839.
According to the teachings of the aforementioned application Ser. No. 09/163,839, a grid of small and closely spaced electrodes are connected to a driver circuit such that a phased d.c. travelling electrostatic wave is established along the grid. Charged particulate material is transported by the electrostatic wave in a desired direction, at a desired velocity.
In such a system, it is desirable to provide a planarized surface over which the particulate material may travel. Such a surface eliminates the problem of particulate material becoming trapped between the electrodes. Furthermore, it is desirable to provide a material over the electrodes to provide rapid charge dissipation at a selected time constant. Arcing between electrodes must be prevented. Wear resistance is also a desired attribute of such a layer. Finally, it is important that such a layer be chemically stable. That is, the layer material must not react with the particulate material nor change characteristics in the presence of the operating environment. However, no known material to date has been able to optimize each of these desired attributes.
It is known to encapsulate electronic devices, such as integrated circuits, in protective coatings. Such coatings may provide physical protection from scratches, and a moisture barrier between the devices and the ambient environment. However, such materials are generally not used as top-surface dielectrics. Furthermore, such insulation and passivation layers typically have very high resistivities to avoid possible electrical shorts between covered leads.
Accordingly, there is a need in the art for a coating which provides a planarized surface, has a selected time constant, is wear resistant, and is chemically stable.
SUMMARY
The present invention is a novel coating for application over an electrode grid particle mover. The coating is an inorganic material which may be compatible with silicon processing, such as chemical vapor deposition (CVD) and may be incorporated into the production of silicon-based components such as an electrode grid.
The coating is a top-surface (that is, not sandwiched between layers) semiconducting dielectric, having a selected time constant to permit electric field charge and dissipation at a selected rate to permit particulate material movement over an underlying electrode grid.
According to one embodiment, the coating is a material selected from the group comprising: a nitride, an oxide, and an oxy-nitride of silicon, and amorphous silicon. The coating may be formed by CVD, plasma assisted CVD (PACVD), or other known processing techniques.
The time constant of the coating, as determined by the product of the dielectric constant and the resistivity of the material, is preferably between 0.5-100 microseconds (ms). Within this range of time constant, particulate material may be moved from electrode to electrode, across a grid of electrodes, at a speed about 1 to 2 meters per second (m/s). However, the larger the time constant, the slower the speed of movement of the particulate material across the electrode grid. The bulk resistivity of the coating is preferably between 1×10 9 and 1×10 12 ohm·centimeters (Ω·cm).
Thus, the present invention and its various embodiments provide numerous advantages discussed above, as well as additional advantages which will be described in further detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained and understood by referring to the following detailed description and the accompanying drawings in which like reference numerals denote like elements as between the various drawings. The drawings, briefly described below, are not to scale.
FIG. 1 is a cross-sectional illustration of a grid-type particulate particle mover having an overcoat thereon according to the present invention.
FIG. 2 is a cross-sectional illustration of a hybrid device, including both an electrode which is part of a particulate transport electrode grid, and a thin film transistor which may be used for driver, clock, logic or other circuitry.
DETAILED DESCRIPTION
In the following detailed description, numeric ranges are provided for various aspects of the embodiments described, such as pressures, temperatures, thicknesses, etc. These recited ranges are to be treated as examples only, and are not intended to limit the scope of the claims hereof. In addition, a number of materials are identified as suitable for various facets of the embodiments, such as for marking materials, layer materials, etc. These recited materials are also to be treated as exemplary, and are not intended to limit the scope of the claims hereof.
With reference now to FIG. 1, there is shown therein in cross-section one embodiment 10 of a grid of electrodes 14 formed on a substrate 12 . Overlying the grid of electrodes 14 is an inorganic overcoat 16 according to the present invention. Other layers (not shown) may form a part of an embodiment of the type shown in FIG. 1, such as interface layers, electrical interconnection layers, etc. In addition, the geometry of an embodiment may vary from that shown in FIG. 1 (although not shown herein). For example electrodes may be formed to have a different profile, and may be formed in differing locations on the substrate. In any case, a traveling electrostatic wave produced by means not shown herein causes particulate material 18 to travel from electrode to electrode in the direction of arrow A.
Electrodes 14 are typically constructed of aluminum, although they may be formed of other materials. A common process for the formation of electrodes 14 is magnetron sputter deposition. Two important criteria for the overcoat of the present invention are that (1) the process used to form it not negatively affect the electrodes or substrate, and (2) that the material from which it is formed not negatively interact with the electrodes or the substrate. Thus, according to one embodiment of the present invention, the overcoat 16 is formed of silicon nitride by a plasma-assisted chemical vapor deposition (PACVD) process. PACVD is a low temperature process, the deposition taking place in the range of 300° C., which is well below the approximately 660° C. melting point of aluminum.
The desired resistivity of the silicon nitride film may be obtained by controlling the ratio of silicon to nitrogen. In one embodiment of the present invention, the ratio of silicon to nitrogen may be on the order of between 1.35:1.0 and 1.45:1.0, preferably 1.40:1.0. Other ratios, however, may still provide the time constant sought by the present invention.
The ultimate thickness of the overcoat layer will depend on the electrode metal thickness. For 0.6 μm thick metal electrodes, an overcoat layer thickness on the order of 0.5 to 1.0 μm will suffice although planarization may not be fully achieved. A layer thickness up to 4.0 μm or thicker may accomplish planarization and still serve to substantially provide the functions described herein.
Importantly, the silicon nitride overcoat will have a resistivity on the order of between 1×10 9 and 1×10 12 Ω−cm, and preferably between 1×10 9 Ω−cm and 1×10 10 Ω−cm, or even between 1×10 9 Ω−cm and 5×10 9 Ω−cm. This is significantly lower than the resistivity of a typical silicon nitride insulation or passivation layer, which would be on the order of 10 14 to 10 16 Ω−cm. The time constant (τ) for the overcoat is related to the resistivity (ρ) and the dielectric constant (ε), as:
τ=ρ·ε
A desired time constant for the proper establishment then dissipation of an electric field for particulate transport at a reasonable speed (1 to 2 m/s) is in the range of 0.5-100 ms. The dielectric constant of silicon nitride is in the range of 6 to 9. Thus, it is required that the resistivity be tailored to achieve the desired time constant. However, time constants up to, for example 1 second, are contemplated hereby, with the consequent reduction in particulate material transport speed. Indeed, a desired transport speed may be obtained by properly selecting the time constant of the layer (i.e., adjusting the resistivity).
While silicon nitride provides the desired control of resistivity (and hence the desired time constant), and is also compatible with current processes used to form the electrode grid (and potentially other layers and devices), it also provides scratch resistance, serves as a moisture barrier, and has low adhesion to many particulate materials, especially marking materials in marking device embodiments. However, a class of other materials may serve to function well as overcoat materials, providing some or all of the advantages discussed above. For example, an oxide of silicon, an oxy-nitride of silicon, and even amorphous silicon can provide many if not all of the above-mentioned advantages.
Thus, while the present invention has been discussed in terms of one embodiment focussing on silicon nitride, it will be apparent to one skilled in the art that various embodiments of a coating for a particulate marking material transport device have been disclosed herein. Furthermore, while embodiments described and alluded to herein are capable providing an adequate overcoat for devices including electrode grids, such as particulate marking material movers, the present invention is not limited to marking material or particle movement, but may find applicability in a variety of other environments requiring an overcoat. For example, the overcoat may be applied over multiple devices to form on a substrate, such as the electrode grid 20 and thin-film transistor 22 , of the embodiment 24 shown in FIG. 2 . Thus, it should be appreciated that the description herein is merely illustrative, and should not be read to limit the scope of the invention nor the claims hereof. | An inorganic, top-surface, semiconducting dielectric overcoat, having a selected time constant permits electric field charge and dissipation at a selected rate to facilitate particulate material movement over an underlying electrode grid. The coating may be made from nitrides, oxides or oxy-nitrides of silicon, or amorphous silicon. A planarized, wear resistant, chemically stable surface, and minimized inter-electrode build-up are also provided by the overcoat. | 7 |
FIELD OF THE INVENTION
This invention relates generally to a device for measuring the flow of a gas containing particulates, and more particularly, to a differential pressure type device for continuously and accurately measuring the flow of a gaseous stream containing entrained particulates, utilizing a self-cleaning orifice in conjunction with thermophoretic pressure taps.
BACKGROUND OF THE INVENTION
Differential-pressure-type flow measuring devices, employing a flow restricting orifice and pressure taps upstream and downstream therefrom connected to pressure sensing means, are generally used for measuring the flows of many types of fluids. These devices, however, cannot be effectively used to measure the flow rates of gaseous streams having significant quantities of entrained particulates therein. The orifice and open pressure taps of such a device quickly become clogged with the particulate matter, which causes erroneous or erratic pressure readings and may necessitate ceasing operations for a time sufficient to permit the removal and cleaning of these components. Several existing devices for measuring the flow of a gas containing entrained particulates rely on a cleaning system which operates in situ to blast or flush deposits from the surfaces of the orifice plate and open pressure taps. These devices, of course, cause erroneous readings during the cleaning cycles, and additionally allow for the steadily deteriorating accuracy of flow readings between cleaning cycles as the particulates slowly build over time.
U.S. Pat. No. 4,671,109 discloses a flow measuring device having pressure sensing elements which are inserted perpendicularly into the flow stream through gate valves. As the flow readings deteriorate, the pressure sensing element is withdrawn from the flow stream to a point just past the valve gate, the valve is closed, and finally the pressure sensing element is completely withdrawn and cleaned before being reinserted. This cleaning activity, of course, results in a period of time during which flow cannot be measured.
U.S. Pat. No. 4,498,347 discloses a flow measuring device utilizing an internal Pitot tube which, as it becomes clogged, is mechanically rotated within the flow stream so as to point generally downstream. Thereafter a blast of purge gas is forced backward through the Pitot tube, to remove adhered solids. Again, it is impossible to obtain accurate pressure readings during the purging cycles.
U.S. Pat. No. 4,651,572 discloses a flow measuring venturi arrangement, wherein the venturi orifice and flow conduit pressure tap are lined with a barrier layer of a porous, wear-resistant material. A rinsing gas may be either constantly or intermittently directed backward through the barrier layer into the flow stream, to keep the venturi orifice and pressure tap free from accumulations of particulates. This method, however, causes contamination of the flow stream by the rinsing gas. Furthermore, particulate fines will, over time, cause the barrier layer to slowly clog, resulting in inaccurate flow readings and the necessity of more severe rinsing.
U.S. Pat. No. 4,572,007 discloses a device and method for repelling particulates from a gas permeable surface using thermophoresis. A particulate-free gas sample may be drawn from the clean side of the hot permeable surface.
Finally, a publication entitled "Thin Film by Conveyorized Atmospheric CVD". by N. M. Gralenski, presented at the ISHM-Internepeon Technical Seminar in Tokyo. Japan, on Jan. 18, 1983, discloses on page 6 a self-cleaning orifice, including two counter-rotating cylinders and associated scrapers, in conjunction with open pressure taps which lead to a conventional pressure measuring device. The counter rotation of the cylinders allows the accumulated particulate material to be removed by the scrapers, thereby resulting in a constant orifice size at steady state operation. However, the disclosed open pressure taps allow the build-up over time of particulates therein, causing a steady deterioration of the accuracy of the flow readings. These deposits may be removed by disassembling the pressure taps, during which time flow readings are not available.
It must be noted that the prior art referred to hereinabove has been collected and reviewed only in light of the present invention as a guide. It is not to be inferred that such diverse art would otherwise be assembled absent the motivation provided by the present invention.
It would be desirable to construct an accurate differential-pressure-type continuous flow measuring device, suitable for measuring the flow of a gaseous stream containing entrained particulates, which is simple to operate and reliable. Such a flow measuring device would not require disassembly and cleaning, would not contaminate the flow stream with a purge gas, and would not give steadily deteriorating flow data due to the accumulation of particulates at the orifice and/or pressure taps.
SUMMARY OF THE INVENTION
Accordant with the present invention, it has surprisingly been discovered that the flow rate of a gas containing entrained particulate matter may be accurately, reliably, and continuously measured utilizing a novel apparatus, comprising:
(A) a flow channel, through which the gas flows;
(B) an orifice disposed within the flow channel, including at least a first surface and a second surface;
(C) means for causing the first surface and second surface independently to move in directions perpendicular to lines normal to the surfaces;
(D) scraping means, for intimately contacting at least a portion of the first surface and of the second surface, at all times while the surfaces are moving, whereby particulates which adhere to the first and second surfaces are removed by the movement of the surfaces past the scraping means;
(E) pressure taps, positioned so as to communicate with the flow channel upstream and downstream from the orifice, the pressure taps additionally in communication with pressure-measuring means, for measuring the pressure differential in the flow channel resulting from the passage of the gas through the orifice; and
(F) thermophoretic heaters, positioned so as to heat the gas within the pressure taps, and thereby exclude particulates therefrom.
The apparatus of the present invention conveniently may be used to measure the flow of a gas containing entrained particulates, such as is generated for example during the chemical vapor deposition of a metal oxide on glass, or as a byproduct during the combustion of fuels or hydrocarbon-containing waste materials.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to structure and method of use, will best be understood from the accompanying description of specific embodiments, when read in connection with the attendant drawings, in which:
FIG. 1 is a perspective view of an apparatus embodying the features of the present invention;
FIG. 2 is a vertical cross-sectional view of the apparatus of FIG. 1, illustrating the orifice within the flow channel;
FIG. 3 is a side, elevational view, partly in cross-section, of the apparatus of FIG. 1, illustrating one of the orifice rolls and the drive mechanism; and
FIG. 4 is a horizontal cross-sectional view of the apparatus of FIG. 1, taken along line 4--4, illustrating the scrapers and flow conduit downstream from the orifice.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring not to FIGS. 1 through 4, there is shown generally at 10 a flow measuring device, useful for measuring the flow of a gas containing particulate material. The device 10 comprises a body 12, including front plates 14 and 16, rear plates 18 and 20, chambers 22 and 24, top and bottom plates 26 and 28, and cylindrical rolls 30 and 32, which together define a flow conduit 34, and an orifice 36 within the flow conduit 34. The front plates 14 and 16, and rear plates 18 and 20, are conveniently affixed to the chambers 22 and 24, respectively, by threaded fasteners 38. The top plate 26 and bottom plate 28 are likewise secured to the chambers 22 and 23 by additional threaded fasteners 40. Resistance heating elements 42 reside within apertures in the chambers 22 and 24.
Cylindrical rolls 30 and 32, having parallel shafts 44 and 46, respectively, are journally mounted in bearing sets 48 and 50, which are set in the front and rear plates 14 and 18, and 16, and 20, respectively. The shafts 44 and 46 have narrow portions 52 and 54, respectively, for securely mounting thereto mating gears 56 and 58, respectively. The gears 56 and 58 engage each other and permit the rolls 30 and 32 to counter-rotate within bores 60 and 62 through the chambers 22 and 24, respectively. The mated gears 56 and 58 are driven by a drive gear 64, which is securely mounted on a drive shaft 66 and driven by a motor assembly 68. The motor assembly 68 is mounted on a support bracket 70, which in turn is fastened to the top plate 26 by threaded fasteners 40.
Scrapers 72 and 74 are adapted to engage portions of the surfaces of the rolls 30 and 32, respectively, and are slidably mounted within grooves 76 and 78, respectively, and urged toward the rolls 30 and 32 by compressed springs 80. Machined passageways 82 and 84 provide communication between the scrapers 72 and 74, respectively, and the flow conduit 34.
Inlet 86 and outlet 88 communicate with the flow conduit 34 and orifice 36 thereby defining a flow channel through which a gas containing particulate matter, whose flow rate is to be measured, may pass. Pressure taps 90 and 92 communicate with the inlet 86 and outlet 88, respectively, and are connected, at their remote ends, to conventional pressure-measuring means indicated at 93, such as for example diaphragms or piezoresistive transducers. Devices for measuring the pressure of a gas stream employing pressure taps are more fully set forth in Kirk-Othmer, "Concise Encyclopedia of Chemical Technology," John Wiley & Sons, N.Y., N.Y. (1985) at pp. 949-950.
Thermophoretic heaters 94 and 96 are attached to the pressure taps 90 and 92, respectively, and are positioned substantially near the inlet 86 and outlet 88, respectively. The illustrated thermophoretic heaters 94 and 96 are electrical resistance heaters which are designed to locally heat the gas contained within the pressure taps in the immediate vicinity of the inlet 86 and outlet 88, respectively. Other methods of applying heat to the pressure taps 90 and 92, such as for example by using steam jacketing, may of course be used.
In operation, a gas containing entrained particulates enters the inlet 86, and passes through the flow conduit 34 and orifice 36, thence out through the outlet 88. At steady-state operation, the flow is substantially constant through each of the inlet 86, flow conduit 34, orifice 36, and outlet 88, which together comprise the flow channel as the term is used herein.
The clearances between the rolls 30 and 32 and the chambers 22 and 24, front plates 14 and 16, rear plates 18 and 20, are exaggerated in FIGS. 2 and 3, but in reality are such that substantially the entire gas flow stream passes through the orifice 36 between the rolls 30 and 32. The chambers 22 and 24 and associated rolls 30 and 32, respectively, are maintained at an elevated temperature by heating elements 42, to keep condensable components in the gas stream vaporized, and to repel particulates from all surfaces generally by thermophoresis.
The orifice 36 comprises the peripheral portions of the surfaces of opposed rolls 30 and 32, which are exposed to and communicate with the flow conduit 34. The orifice 36 is a constriction in the flow channel, which causes an increase in the velocity of the gas passing therethrough in relation to the velocity of the gas upstream from the orifice 36. The orifice 36 simultaneously causes a corresponding decrease in pressure within the flow channel. Therefore, an increase in the flow of gas through the flow conduit causes an increase in the pressure drop across the orifice 36. The relationship between pressure drop and flow rate, as a function of orifice size, is more fully set forth in Perry, Chilton, and Kirkpatrick, "Chemical Engineer's Handbook", McGraw-Hill Company, 1963. The orifice size may be increased in the illustrated embodiment of the present invention, by separating the chambers 22 and 24 at parting line 98 and inserting shims such as those shown in phantom at 100. This would necessitate larger diameter gears 56 and 58, and a smaller diameter drive gear 64.
Particulates entrained in the flowing gas stream tend to deposit upon the surfaces within the flow conduit 34. To maintain a constant orifice size, the rolls 30 and 32 are counter-rotated by means of the motor assembly 68 and associated drive gear 64 and meshed gears 56 and 58. The rolls 30 and 32 are counter-rotated so as to cause the surfaces exposed to the flow conduit 34 to individually move generally in the direction toward the outlet 88. As the exposed, moving surfaces of the rolls 30 and 32 engage the scrapers 72 and 74, respectively, the particulates adhered thereto are removed and carried by the flowing gas stream out the outlet 88. Polytetrafluoroethylene scrapers have been found particularly suitable for use in the present invention. At steady-state, the surfaces of the rolls 30 and 32, at the orifice 36, have a constant thickness of particulate matter adhered thereto. The exposed surfaces of the rolls 30 and 32 are continuously renewed, meaning that clean, scraped surfaces of rolls 30 and 32 continuously emerge from bores 60 and 62, respectively due to the continuous counter-rotation of the rolls 30 and 32.
Particulates entrained in the flowing gas stream are prevented from entering into and accumulating in pressure taps 90 and 92, by the action of the thermophoretic heaters 94 and 95, respectively. Thermophoresis is generally defined as motion induced in a particle due to a temperature gradient in the atmosphere surrounding the particle. Particles are thus induced to move from the hot to the cold regions. The thermophoretic heaters elevate the temperature of the gas within the pressure taps 90 and 92 over that of the gas in the inlet 86 and outlet 88. Although there is no precise temperature differential required in order to exclude particulates from the pressure taps 90 and 92 according to the present invention, temperatures in excess of 100° F. have been found to be sufficient. Thermophoresis permits the communication of the pressures of the gas in the inlet 86 and outlet 88, through the pressure taps 90 and 92, respectively, to the pressure-measuring device 92, while at the same time precluding particulates from entering therein. The thermophoretic heaters 94 and 96 effectively prevent the contamination of the pressure taps 90 and 92, respectively, with relatively little dependence upon the physiochemical properties of the particulates. The operation of the thermophoretic heaters 94 and 96 is not limited by the size of the suspended particulates, the composition, nor the concentration.
While certain representative embodiments and details have been shown for purposes of illustrating the present invention, it will be apparent to those ordinarily skilled in the art that various changes in applications can be made therein, and that the invention may be practiced otherwise than as specifically illustrated and described without departing from its spirit and scope. For example, the pressure differential may be measured utilizing pressure taps, wherein one of the taps is positioned substantially at the orifice. As another example, surfaces other than cylindrical surfaces may be used to form the orifice, provided that the individual surfaces continuously move in directions perpendicular to lines normal to the surfaces, and engage scraping means to remove accumulated particulates therefrom. | The flow of a gas containing entrained particulate matter may be accurately, reliably and continuously measured, utilizing an apparatus comprising a self-cleaning orifice, including counter-rotating continuously scraped cylinders, and thermophoretic pressure taps. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to optical devices, specifically range finders, and particularly to range finders in which a projector directs light onto an object and a number of independent light receiving elements are able to produce outputs corresponding to imaging positions on the light receiving elements so as to measure the distance to the object.
2. Description of the Prior Art
U.S. Pat. No. 3,820,129 discloses the basic arrangement of such type of range finder. In this patent, a bridge circuit detects the difference in outputs of two light receiving elements and this difference is used as a distance signal. However, this arrangement suffers from the fact that the reflection factor of the object whose distance is being measured can vary the difference in outputs of the elements. This prevents an accurate range finding indication. Also, this patent discloses projecting light being received through a filter for eliminating the influence of external light. However, such a method cannot completely eliminate external light. Hence, the outputs of the light receiving elements will be influenced by the ambient light, and could thus result in erroneous distance outputs.
SUMMARY OF THE INVENTION
An object of the present invention is to improve prior distance measuring devices and is characterized by a circuit arrangement which responds to the differences in outputs of the two light receiving elements when the light projector projects light and when the the light projector does not project lights, and then obtains the ratio of the differences in the outputs of the light receiving elements so as to detect the distance to an object. Such an arrangement can prevent the undesirable influence of external light and errors derived from the reflection factor. Hence, such a device corrects the range finding operation under a wide range of circumstances.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating an arrangement of a range finder according to the present invention.
FIG. 2 is a circuit diagram illustrating a circuit diagram for the range finder of FIG. 1.
FIG. 3 is a timing chart for the circuit of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawings, FIG. 1 is a schematic diagram showing an arrangement of an automatic focusing device embodying features features of the present invention. Here, a projection light source 1, such as an LED, LD (laser diode), or Xe lamp, etc., projects light onto the object through a light projecting lens 2 so as to form an image of the light source on the object. Luminous flux reaching the object is partially reflected and reimaged by a light receiving lens 3 onto a light receiving device 4 behind the lens 3 which is separated an appropriate distance from the light projecting lens 2. The position of the image being re-imaged will occur at the position 5a when the object reflecting the light is far from the device of FIG. 1, but will be re-imaged at position 5b when the object is close to the apparatus of FIG. 1. The distance between the light projecting lens 2 and the light receiving lens 3 forms a base line length. Hence, when the object is far away, the reflected luminous flux passes along an optical path 6a and when the object is closer, the luminous flux passes along an optical path 6b.
The light receiving device 4 is divided into two light receiving elements 4a and 4b independent of each other and separated by a boundary 4c as shown in the drawing. The ratio of outputs of the elements 4a and 4b varies according to the positions of the images 5a or 5b on the light receiving elements. The positions depend on the distances to the object and this allows a range finding operation to be performed. While the boundary in this example is a straight line inclined relative to the base line, the shape of the boundary line is not limited to that shown in this example as long as the ratio of outputs of the light receiving elements changes by a specific relationship according to the positions of the images. In order to have the device in this example function properly, images on the light receiving elements should have shapes such as shown in the drawing. This is realized, for example, by using a cylindrical lens as the light receiving lens 3. That is, a cylindrical lens makes an image of a projection-light-souce-illuminated object linear on the light receiving element. Thus, wherever images are formed on the light receiving elements, depending on distances to an object, the ratio of outputs of two light receiving elements will exactly correspond to the distance.
FIG. 2 is a diagram illustrating a circuit arrangement of the automatic focusing device shown in FIG. 1, and timing charts therefor are shown in FIGS. 3A to 3C. In FIG. 2, a control A actuates each part of the circuit by applying a high level signal thereto. The projection light source 1 is made to flicker in synchronism with a signal from the control A. Two light receiving elements 4a and 4b are independent photo-electric conversion elements, and one pole of each is grounded and the other pole is introduced into an amplifier. Identical circuits to process outputs of the elements 4a and 4b are shown by frames 7a and are composed, for simplicity, of one-dot chain lines. An explanation is given only for the signal processing circuit in frame 7a.
Here, an amplifier 8 receives the output of the light receiving element 4a at one input terminal, has its other input terminal grounded, and forms an amplifier circuit for the output of the light receiving element 4a together with a resistor 9. A known sample holding circuit composed of a switch 10a, a capacitor 10b, and a buffer amplifier 10c is connected to an output terminal of the ampliflier 8. The switch 10a is closed as it receives a high level signal from the control A, and when a signal from the amplifier 8 is introduced, the latter signal is memorized in the capacitor 10b. This signal is retained and formed as an output even when the switch 10a receives a low level signal from the control part A and is opened.
An output terminal of the sample holding circuit 10 is connected to one of the input terminals of an amplifier 13 by means of resistors 11 and 12. The output of the amplifier 8 which is introduced into the sample holding circuit 10 at its one end is also supplied to the amplifier 13 through a resistance 14. A feedback resistance 15 is inserted between an output terminal and an input terminal of the amplifier 13, and resistances 14, 11, 12 and 15 a differential amplifier circuit with amplifier 13.
In operation, when the projection light source 1 receives a low signal from the control A and is in a non-light-projecting condition, the switch 10a has a high level signal impressed thereon and is closed to cause capacitor 10b to accumulate output signals from the light receiving element 4a through the amplifier 8. When the projection light source 1 is set in the light projection condition by a low signal from the control A, the low signal opens the switch 10a. The output signal from the light receiving element 4a, which is produced when light is being projected by the source 1, will not be introduced into the sample holding circuit 10. While a signal during the non-light-projecting condition is always introduced into one end of the amplifier 13 from the sample holding circuit 10, a signal corresponding to the light projecting condition is always introduced into the other end of the amplifier 13 through the amplifier 8 and the resistance 14. Therefore, in the light projecting condition, a difference in outputs of elements 4a between the time light is being projected on the object and the time light is not being projected on the object can be obtained at an output terminal of the amplifier 13. That is, only an output of the image caused by the projection light source on the light receiving element 4a will be obtained. A circuit shown as 7b performs the same function as that of the circuit 7a, and as a result, the outputs of the circuits 7a and 7b will be the outputs of the images caused by the projection light source on each of the light receiving elements 4a and 4b. A three-inputs multiplier 16 with inputs of X, Y, Z and is a known type of circuit can obtain ##EQU1## as its output. Ordinarily this type of multiplier is actuated by current, but recently voltage actuation type multipliers (for example, quadrant multiplier 8013, made by Intersil, Inc.) have become available commercially.
Since outpts of the circuits 7a, 7b are imparted to the terminal Y and terminal Z respectively as voltages, a voltage actuation type of multiplier is suitable. If a predetermined value of voltage V o is imparted to a terminal X by a suitable power source 17, a voltage corresponding to the output ratio of the light receiving elements 4a and 4b will be produced at the output terminal of the multiplier 16. That is, an output corresponding to the object distance will be produced.
A known sample holding circuit 18 receives a signal from the multiplier 16 as an input thereto. The circuit 18 is to receive a high level signal from the control part A during the light projecting condition to have the signal from the multiplier 16 introduced thereinto, and at the same time is to hold the signal during the non-light-projecting condition. Hence, the circuit 18 always produces the signal of the multiplier 16 in the light projecting condition. That is, the signal from the multiplier 16 during the light projecting condition is the ratio of the difference in signals in the light projecting and non-light-projecting conditions of the light receiving elements 4, that is a distance signal. However, a ratio of signals both of which are in the non-light-projecting condition will be produced under the non-light-projecting condition. Therefore, the latter ratio in the non-light-projecting condition is to be eliminated for stablizing control of a photo-taking or photographic objective lens. An amplifier 19 forms a differential amplifier circuit with resistors 20, 21, 22 and 23. The output of a potentiometer 25 associated with movement of a photo-taking or photographic objective lens 24 and the aforementioned distance signal are introduced into the circuit 19. A predetermined value of voltage V is imparted to the potentiometer 25 and the voltage at the sliding contact of resistance 25 corresponds to the position of the photo-taking lens. Therefore, the output of the differential amplifier circuit 19 corresponds to the deviation of the output representing the object distance and the regulated position of the photo-taking lens 24. A motor 27 is arranged to be able to control the photo-taking lens 24 through a gear train 26. When the output of the differential amplifier circuit 19 is not zero, in other words, when the photo-taking lens is not properly focused on an object, the motor rotates to reduce the deviation to zero. Thus, an ordinary servo operation is performed.
Applications of the present invention are not limited to such a servo-control operation. Instead, automatic focus adjustment of an optical system such as a photo-taking lens, etc. or manual focus adjustment following some indication can be produced in various ways, using the output of the sample holding circuit 18a which is a distance signal.
The sample holding circuits 10 and 18 can have their functions reversed with respect to the light projecting state and the non-light-projecting state.
The present invention provides a circuit arrangement in an automatic focusing device which receives an image formed on an object by a projection light source in order to measure a distance to the object by the position of the received image on two spaced light receiving elements. The difference in outputs of the light receiving elements during a light projecting condition and a non-light-projecting condition of the projection light source is detected. This completely eliminates the influcence of external light. By detecting the ratio of the output difference, a correct range finding signal can be obtained uninfluenced by the distance to an object and the object's reflection factor. Therefore, the circuit of the present invention makes it possible to obtain a stable and correct range finding result in a comparatively simple manner. | In the disclosed optical device, independent light sensors located at separate positions which receive light projected by a projector and reflected by an object whose distance is to be measured, produce outputs corresponding to their respective positions. A distance indicator indicates the distance to the object on the basis of the ratio of outputs of the sensors. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a replaceable cushion for a display assembly. More particularly, this invention relates to a replaceable elastomeric cushion for use with a glass panel and support fixture hardware interface, useful for display structures.
2. Background of the Invention
The use of glass panels in conjunction with metal and woodframes has long been utilized in modern furniture design. For example, glass panels have been used in conjunction with tables, shelving, display cases and other fixtures. Such glass panels may be used as a shelf or table surface in a horizontal orientation or as a structural member supporting fixtures in a vertical orientation to create an aesthetically pleasing effect as well as maximum structural stability. A problem with using such metal components in conjunction with glass panels is the potential for marring or scratching the glass panel, thus diminishing the aesthetic beauty of the particular piece of furniture.
Prior devices attempted to rectify this problem by attaching a piece of soft cushion material, such as some form of plastic or rubber, to the surfaces of the metal support structure by glue, epoxy or other adhesive before the assembly of the particular fixture to fix the cushion in place during assembly. The glass panel was then attached to the metal frame through contact with the soft cushion material in the conventional manner. Thus, the metal support structure did not directly contact the glass panel and did not mar or scratch the glass panel's surface.
However, these devices suffered from a lack of durability. Since the glass panel was pressed against the soft cushion material to insure that the glass panel stayed in place, a certain amount of wear and tear is inflicted on the soft material, especially if the glass panel is often removed and replaced. When the wear and tear damaged the soft cushion material, the soft cushion material had to be replaced. However, since the soft cushion material was permanently attached to the metal structure, both it and the support structure had to be replaced, although the support structure itself was otherwise usable. If the adhesive was omitted, difficulties were found in the assembling of the support structure as the cushion tended to move away from its proper position on the abutting surface during assembly.
In the context of the present invention, the use of an easily replaceable elastomeric cushion for secure placement between a support structure and a glass panel is contemplated as the beneficial advance. The use of such cushions will eliminate the wasteful replacement of metal support frames.
OBJECTS OF THE INVENTION
In view of the foregoing, it is an object of the invention to provide a replaceable elastomeric cushion for a metal structure supporting a glass panel.
Another object is to provide a replaceable elastomeric cushion device which may be easily removed from the support structure.
SUMMARY OF THE INVENTION
The foregoing objects are met by a replaceable elastomeric cushion for use with a support structure and glass panel assembly. The replaceable elastomeric cushion is made of a soft compliant material, having one substantially planar surface for contacting the glass panel. A second surface has a number of projecting members which fit into corresponding orifices in the support fixture.
The mounting structure comprises a frame structure with an abutting surface having an orifice provided therein, against which a replaceable elastomeric cushion having two opposite substantially flat surfaces is placed. The surface of the replaceable elastomeric cushion contacting the abutting surface of the mounting structure has a number of projecting members fitting snugly within the orifices of the abutting surface of the mounting structure. The second flat surface in turn is in contact with a glass panel. The glass panel may be then urged against the replaceable elastomeric cushion, separating the glass panel from the mounting structure to avoid damage to the glass panel. The entire assembly may be then assembled in a conventional manner. Since the replaceable cushion is not permanently attached to the support fixture, it may be easily replaced without having to replace the support fixture.
Replacing the replaceable elastomeric cushion is readily accomplished by merely disassembling the glass panel and mounting structure assembly and pulling the replaceable elastomeric cushion away from the abutting surface of the mounting structure so as to disengage the projecting members from the orifices of the abutting surface and inserting the projecting numbers of a new elastomeric cushion therein.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood from the following detailed description when read with reference to the drawings in which:
FIG. 1 shows a front elevation view of a first embodiment of the replaceable elastomeric cushion;
FIG. 2 shows a side elevation view of the first embodiment of the replaceable elastomeric cushion;
FIG. 3 shows a perspective view of the first embodiment of the elastomeric replaceable cushion;
FIG. 4 shows a side elevation view of a second embodiment of the replaceable elastomeric cushion having a single projecting member;
FIG. 5 shows a perspective view of the second embodiment of the replaceable elastomeric cushion;
FIG. 6 shows a perspective view of a third embodiment, wherein a surface of the replaceable elastomeric cushion has a textured surface;
FIG. 7 shows a first assembly of a mounting structure, glass panel and the first embodiment of the replaceable elastomeric cushion combination;
FIG. 8 shows a second assembly of a mounting structure, glass panel and the first embodiment of the replaceable elastomeric cushion combination.
FIG. 9 shows a third assembly of a mounting structure, glass panel and the first embodiment of the replaceable elastomeric cushion combination.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A first embodiment of the replaceable elastomeric cushion 2 according to the present invention is shown in FIGS. 1 through 3. A rectangularly shaped replaceable cushion 2 has two substantially flat surfaces 4, 6. In the preferred embodiment the cushion 2 has a length of 35/8 inches (9.2 cm), a width of 5/8 inches (1.6 cm) and a thickness of 5/8 inches (0.31 cm). Of course cushions having different dimensions may be made according to the invention. The surface 4 is substantially smooth and is used to contact a glass panel 12 when the cushion 2 is installed in the mounting assembly which will be discussed below. Several projecting members 8 extend perpendicularly from the surface 6. In the preferred embodiment, the projecting members 8 and the cushion 2 are made of one piece of elastomeric material, such as black rubber. However other elastomeric materials such as plastic may be utilized for the invention. The projecting members 8 are of a cylindrical shape, with one end disposed on the surface 6. In the preferred embodiment each projecting member 8 has a height and diameter of 5/32 inches (0.40 cm). Of course, the projecting member 8 may be formed to be a square, triangle or any other shape and have any appropriate height.
A second embodiment of the present invention is shown in FIGS. 4 and 5. A cushion 72 has two substantially flat surfaces 74, 76. The surface 74 contacts the glass panel 12 when the cushion 72 is installed in the mounting assembly. In this embodiment, only one projecting member 78 extends perpendicularly from the surface 76. The projecting member 78 is cylindrical in shape, with one end disposed on the surface 76. In the preferred embodiment, projecting member 78 has a height and diameter of 5/32 inches (0.40 cm). Of course, any appropriate shape and height may be used for the projecting member 78. The cushion 72 and the projecting member 78 likewise can be molded from a single piece of black rubber, or other elastomeric material, such as plastic.
A third embodiment of the present invention is shown in FIG. 6, wherein a cushion 82 has a substantially flat surface 84 and an opposite textured surface 86. As may be seen, the textured surface 86 is molded or embossed with a repeating diamond pattern having raised molded squares 87. It should be understood that other patterns may be utilized for providing a texture to the surface 86, such as knurling, small bumps and the like. The projecting members 88 extend out perpendicularly from the surface 84. The projecting members 88 are preferably of a generally cylindrical shape and the projecting members 88 and the cushion 82 are likewise made from an elastomeric material, such as black rubber. The textured surface 86 is intended to be in contact with the glass panel 12 when the cushion 82 is installed on the mounting assembly, as discussed below.
A mounting assembly such as a shelf, display rack or table is shown in two examples illustrated in FIGS. 7 and 8. Of course, other different fixtures may advantageously utilize the cushions 2, 72 and 84 in conjunction with the glass panel 12.
A first example of the present invention as installed in a mounting assembly 11 is shown in FIG. 7. This embodiment is especially useful for display shelves having a glass backing, the glass backing being the aforementioned glass panel 12. FIG. 7 shows four replaceable cushions 2 which are disposed against an abutting surface 21 of a back fixture 14 and an abutting surface 25 of a front fixture 16. The abutting surface 21 of the back fixture 14 has a number of orifices 22 which correspond in size and position to the projecting members 8 of the rubber cushion 2. In this embodiment, the back fixture 14 is made of stamped metal. The back fixture 14 also has two mounting holes 20. The mounting holes 20 and orifices 22 may either be stamped or drilled into the back fixture 14. Of course, other materials and fabrication methods may be utilized for the back fixture 14. The replaceable elastomeric cushions 2 are removably attached to the back fixture 14 by simply inserting the projecting members 8 into orifices 22.
Front fixture 16 is composed of a front piece 30, which further defines the abutting surface 25 having the orifices 23 (shown by dashed lines in FIG. 7) corresponding to the projecting members 8 of the replaceable cushions 2. The front piece 30 also has mounting holes 24 near its top and bottom. A shelf bracket 28 (or other support device) projects out perpendicularly from the front piece 30. Like the back fixture 14, the front fixture 16 is preferably made of stamped metal with the orifices 23 and mounting holes 24 being drilled or stamped. Of course, other materials and fabrication methods may be utilized for the front fixture 16.
Assembly of the mounting assembly 11 of the present embodiment is extremely straightforward. The replaceable cushions 2 are disposed on the front fixture 16 and the back fixture 14 by inserting the projecting members 8 into the orifices 22 and 23 respectively. The projecting members 8 fit snugly in the orifices 22 and 23 so as to restrain the replaceable cushion 2 and prevent accidental separation from the front fixture 16 and the back fixture during assembly. The glass panels 12 are then positioned against the replaceable cushions 2 on the back fixture 14. The front fixture 16 is placed against the glass panels 12 so that the replaceable cushions 2 installed on the front piece 30 are in contact with the glass panels 12 and the mounting holes 24 correspond in location to mounting holes 20. The front fixture 16 is then attached to the back fixture 14 by means of fastening devices, such as bolts 26. The bolts 26 are then tightened so that pressure is generated within the assembly and the glass panels 12 are kept in place by being compressably urged against the cushions 2 located between the front fixture 16 and the back fixture 14. Other methods of assembly may be utilized as well as other fastening means, such as rivets and screws.
A second example of a mounting structure is shown in FIG. 8, which shows a shelf assembly 41 with a backing composed of the glass panel 12. Identical support fixtures 40 are used to sandwich the glass panel 12 therebetween. This embodiment utilizes four replaceable cushions 2 with the projecting members 8. In this embodiment, the support fixture 40 is made of stamped metal, but any similar material may be used. The support fixture 40 has a bracket 42 for installation of further shelving. The bracket 42 is attached to a clamping frame 44, which has a number of mounting holes 46 extending therethrough. The clamping frame 44 also has a number of orifices 48 at abutting surfaces 45 against which the glass panel 12 is supported. The orifices 48 may be drilled into the clamping frame 44 or die stamped or created by some other method. The orifices 48 have the same general shape and location as the projecting members 8 of the replaceable cushions 2, thus allowing the replaceable cushions 2 to be secured via the orifices 48.
The mounting assembly 41 is assembled by means of the steps described below, but other assembly methods may be utilized. The replaceable cushions 2 are installed on the clamping frame 44 by inserting the projecting members 8 in the orifices 48 of the abutting surfaces 45. The projecting members 8 fit snugly in the orifices 48 so the replaceable cushions 2 are not accidentally separated from clamping frame 44. The glass panel 12 is then placed against the replaceable elastomeric cushions 2 on one of the support fixtures 40. The second support fixture 40 is then positioned with the replaceable cushions 2 in contact with the glass panel 12. The support fixtures 40 are then joined together by means of fastening devices such as bolts 50. Other fastening means may be used, such as rivets and screws. By tightening the bolts 50, the glass panel 12 is thus held in place between the support fixtures 40 by the pressure applied to the replaceable cushions 2 by the clamping frames 44.
A third example of a mounting structure is shown in FIG. 9, which shows a shelf assembly 101 with backings composed of glass panels 12. Identical "U" shaped support fixtures 104 are used to sandwich the glass panels 12 therebetween. Although the "U" shaped support fixtures 104 are shown in FIG. 9 as being offset, the arrangement can of course be modified to increase the flexibility of the mounting structure. This embodiment utilizes eight replaceable cushions 2 with the projecting members 8 which are disposed against an abutting surface 105 of "U" shaped support fixtures 104 or an abutting surface 103 of mounting fixtures 107 depending on which side surface of glass panel 12 the cushion 2 may be placed. The abutting surfaces 105 and the abutting surfaces 103 have a number of orifices 108 which correspond in size and position to the projecting members 8 of the rubber cushions 2.
The "U" shaped support fixtures 104 and mounting fixtures 107 are made of stamped metal, but any similar material may be used. The "U" shaped support fixtures 104 support glass shelf 112. The "U" shaped support fixtures 104 and the mounting fixtures 107 have a number of mounting holes 106 extending therethrough. The mounting holes 106 and orifices 108 may either be stamped or drilled into their respective fixtures. Of course, other materials and fabrication methods may be utilized for the "U" shaped support fixtures 104 and the mounting fixtures 107.
Assembly of shelf assembly 101 is by means of the steps described below, but other assembly methods may be utilized. The replaceable cushions 2 are installed on the "U" shaped support frames 104 by inserting projecting members 8 in the orifices 108 of the abutting surfaces 105. The projecting members 8 fit snugly in the orifices 108 so the replaceable cushions 2 are not accidentally separated from "U" shaped support fixtures 104. Likewise, the replaceable cushions 2 are installed on mounting fixtures 107 by inserting projecting members 8 in orifices 108 of the abutting surfaces 103. The glass panels 12 are then placed against the opposite side of the replaceable elastomeric cushions 2 on the "U" shaped support fixtures 104. The mounting fixtures 107 are then positioned such that the side of the replaceable cushions 2 without projecting members 8 is in contact with glass panels 12. The mounting fixtures 107 and the "U" shaped support fixtures 104 are then joined together by means of fastening devices such as bolts 110. Other fastening means may be used, such as rivets and screws. By tightening the bolts 110, the glass panels 12 are held in place between the "U" shaped support fixtures 104 and the mounting fixtures 107 by the pressure applied to the replaceable cushions.
These examples are meant to be illustrative of uses of the present invention. Other variations of structures may employ the invention. For example, glass panels may be used in conjunction with the invention in a horizontal orientation such as in a glass shelf or tabletop or used to create a unique design having the glass panels at differing angles of orientation. Of course, the replaceable cushion 72, as shown in FIGS. 4 and 5, or the replaceable cushion 82, as shown in FIG. 6, may be substituted for the replaceable cushion 2 in any of the above embodiments or any other structure. In addition, any number of replaceable cushions 2, 72 or 82 may be utilized in support structures.
The replaceable cushions 2 of the present invention allow for easy replacement when worn out by the constant pressure existing from contact of the glass panel and the support structure and the wear from disassembly and assembly. The cushions may be removed by simply disassembling the support fixtures and the glass panel and replacing the worn cushions with new cushions and reassembling the support fixtures and glass panel. Thus, when the cushions wear out, the support fixtures need not be replaced.
The aforementioned description is not to be interpreted to exclude other glass panel arrangements advantageously employing the present invention. Furthermore, it is to be understood that the above described replaceable cushion is merely an illustrative embodiment of the principles of this invention and that numerous other arrangements and advantages may be devised by those skilled in the art without departing from the spirit and scope of the invention. | A replaceable elastomeric cushion for use in an assembly with a glass panel and support fixture is disclosed. The replaceable elastomeric cushions are made of a soft compliant material and have one substantially planar surface for contacting the glass panel. A second surface has a number of projecting members which fit into corresponding orifices in the support fixture. The replaceable cushion thus rests between the glass panel and the support fixture to prevent marring or scratching of the glass. Since the replaceable cushions are not permanently attached to the support fixture, they may be easily replaced without having to replace the support fixture. | 0 |
TECHNICAL FIELD
[0001] This invention relates to managing print jobs.
BACKGROUND
[0002] Short-run print jobs, e.g., business cards, letterheads, sell sheets, invitations, announcements, folders, brochures, and marketing materials, are generally printed by commercial printers using relatively small, low cost printing equipment. Because of the set-up time involved in changing from one print job to the next, and the relatively low volumes printed (often less than 1000 units/order), the printing cost is typically relatively high, e.g., $20-50 per thousand square inches (“MSI”). In some cases, several print jobs are manually “ganged” together (consolidated or aggregated) onto a single master, in an attempt to reduce the average set-up time per order. Another strategy for controlling cost, employed by printers of products such as invitations, office stationery, and address labels, is to offer customers a limited selection of papers, formats and colors from which to choose.
[0003] Printing costs per MSI are much lower for high-volume high-quality full-color publishing and packaging print jobs, e.g., food labels, consumer good packaging, magazines, catalogues and high volume marketing materials. Publishing and packaging printing is generally done using large, expensive offset printing presses (either web press or sheet feeding of large-format paper stock) in a highly automated large-volume manufacturing environment. Because these presses have high set-up and amortization costs, their use has been focused on long print runs that are typical in the packaging and publishing segments of the printing market.
[0004] Attempts have been made to reduce the high cost of short-run printing. Set-up costs may be reduced by using rapid changeover production machinery, digital technologies, thermographic printing, or single-color offset printing. Typically, these techniques assume that each print job is to be processed as a discrete production run subject to economies of scale based on the quantity of that print job.
[0005] Another approach has been to preprint high volumes of a standard base product (e.g., invitation “blanks” bearing high quality color graphics) using high quality offset printing, and then to overprint variable, custom text (e.g., the text of the invitation) for each order, typically using simpler printing processes and conventional short run printing methods.
[0006] Yet another approach has been to reduce the cost of setting up a print job by letting the customer, or an intermediary other than the printer, be responsible for the layout, sales and administration aspects of the customer's order. For example, some companies, such as Hallmark, have provided WYSIWYG (“what you see is what you get”) terminals at which a customer can view a WYSIWYG display of the item to be printed, and then upload information regarding the print job to a local or remote printing site. Another example of this approach is desktop publishing software, which allows a customer to design a print job on-screen.
[0007] Computers have been used to reduce cost and improve efficiency of printing processes, e.g., to make the process of page layout, proofing, approvals and transmission to the printing floor more efficient. For example, in the newspaper and printing industries, on-the-fly page markups have been sent directly to the production floor using digital workflow technology. Prepress software and equipment that automates workflow is also used by printers and graphics professionals. Recently, Internet companies such as Noosh and Impresse have been providing services that improve the efficiency of buyer-seller transactions involving printing, e.g., by giving users of their websites the ability to “connect” with a wide variety of print vendors, from short-run demand printers to long-run offset printers.
SUMMARY
[0008] The invention features method for managing print jobs.
[0009] In one aspect, the invention features a method including (a) accumulating discrete print jobs electronically from respective customers, (b) aggregating the discrete print jobs into aggregate print jobs, each of the aggregate print jobs being printable at one time on units of an integral print medium, and (b) electronically distributing the aggregate print jobs to respective printers for printing.
[0010] Implementations of this aspect of the invention may include one or more of the following features. The integral print medium may include cut sheets of paper, or large rolls of paper designed for use on offset printing web presses, e.g., rolls having roll widths of 20 inches or more. The print jobs are accumulated through web browsers. Printing of the aggregate print jobs is done during periods of otherwise unused capacity. Each of the discrete print jobs includes a run of fewer than 5,000 copies. Printing is done on large-scale offset full-color presses. Aggregating is done automatically.
[0011] In another aspect, the invention features a method including (a) defining a two-dimensional grid of discrete print jobs, the print jobs occupying positions along the two dimensions of the grid, the grid corresponding to a substrate to be printed, the print jobs being arranged on the grid so that at least at some different positions along each of the two dimensions of the grid are print jobs that have different content to be printed on the substrate, (b) printing the print jobs on the substrate at their respective positions defined by the grid, (c) cutting the substrate to separate the print jobs, and (d) distributing at least some of the separated print jobs to different customer locations. In some implementations, the print jobs are in different formats, and all of the print jobs are printed on the substrate at one time.
[0012] In a further aspect, the invention features a method including defining a two-dimensional grid of discrete print jobs, the print jobs occupying positions along the two dimensions of the grid, the grid corresponding to cut sheets of a substrate to be printed, printing the print jobs on each of the sheets at their respective positions defined by the grid, and cutting the sheets of the substrate along each of the two dimensions to separate the print jobs into rectangular stacks. In some implementations, each stack defines a separate print job.
[0013] The invention also features a method including defining a two-dimensional grid of discrete print jobs, the print jobs occupying positions along the two dimensions of the grid, the grid corresponding to a non-preprinted substrate to be printed, printing the print jobs on each of the sheets at their respective positions defined by the grid, and cutting the sheets of the substrate along each of the two dimensions to separate the print jobs.
[0014] In another aspect, the invention features a method including defining a two-dimensional grid of discrete print jobs, the print jobs occupying positions along the two dimensions of the grid, the grid corresponding to a substrate to be printed, printing the print jobs in full color on each of the sheets at their respective positions defined by the grid, and cutting the sheets of the substrate along each of the two dimensions to separate the print jobs.
[0015] In a further aspect, the invention features a method including receiving orders for discrete print jobs from customers, each of the orders being received at an associated ordering time, each of the orders having an associated delivery time, the periods between the ordering times and the delivery times of at least some of the print jobs being different, aggregating a set of the print jobs that have essentially the same associated delivery time into an aggregate print job to be printed at one time on shared substrate units, and arranging for the production of the aggregate print job at a time that is just ahead of the delivery time. In some implementations, the method also includes adjusting the prices of the discrete print jobs based on the period between the ordering time and the delivery time. The method may also include arranging for the production during periods of unused printing capacity.
[0016] The invention also features a method including offering the printing of discrete print jobs to customers in at least two different service levels, one of the service levels including printing the print jobs free for the customers and another of the service levels including charging for the print jobs, receiving orders from customers for print jobs at selected service levels, and aggregating a set of the print jobs for printing at one time on shared substrate units. The service levels may be associated with speed of turnaround, and/or with the presence or absence of third-party advertising on the print job.
[0017] In yet another aspect, the invention features a method including receiving orders for discrete print jobs from customers, electronically creating and accumulating non-commodity information associated with each of the print jobs, aggregating a set of the print jobs into an aggregate print job for printing at one time on shared substrate units, and arranging for the production of the aggregate print job using commodity supplies and services including non-preprinted paper as the common substrate, and commodity inks. The arranging for production may include locating printers having unused capacity suitable for the aggregate print job.
[0018] In another aspect, the invention features a method including receiving orders for discrete print jobs from customers, automating the generation of non-commodity information associated with the print jobs, aggregating a set of the print jobs into an aggregate print job for printing at one time on shared substrate units, and arranging for production of the aggregate print job in accordance with the non-commodity information. The non-commodity information may include at least one of content, approval service, price, delivery terms, color verification services, quantity, and set up steps.
[0019] In a further aspect, the invention features a method including receiving orders for discrete print jobs from customers, defining an aggregate print job comprising a set of the discrete print jobs for printing at one time on shared substrate units, the aggregate print job having a delivery time, enabling printers having equipment not economically suitable for completing individual ones of the discrete print jobs to bid competitively for the aggregate print job up to a time just ahead of the delivery time, and awarding the aggregate print job to one of the printers prior to the delivery time. The enabling and awarding may be done electronically.
[0020] The invention also features a method including (a) receiving information defining discrete print jobs each of which is alone economically unfeasible for printing on high volume printing equipment, (b) aggregating sets of the discrete print jobs into aggregate print jobs, each of the aggregate printing jobs being configured for printing at one time on units of a common substrate, the aggregate print jobs being economically feasible for printing on high volume printing equipment, each of the aggregate printing jobs having a defined delivery time, (c) making the aggregate print jobs available up to just before the delivery time, for competitive bidding by printers having the high volume printing equipment, and (d) awarding each of the aggregate print jobs to the printer with the most competitive bid based on predetermined criteria.
[0021] In another aspect, the invention features a method including (a) using a high volume printing machine to produce high volume print jobs, each of the high volume print jobs comprising printing of only a large number of identical images one after the other, (b) determining the availability, between high volumes print jobs, of unused printing capacity, (c) bidding for aggregate print jobs that can be produced economically on the high volume printing machine using the unused printing capacity, each of the aggregate print jobs comprising an aggregation of discrete print jobs that would be economically unfeasible to print separately using the printing machine, and (d) printing at least one of the aggregate print jobs.
[0022] In a further aspect, the invention features a method including performing graphic design of a discrete print job on a design application that runs on a web browser, transferring the print job to a web server for storage after the graphic design is performed, modifying the print job on the web browser, and updating the print job on the web server after the modifying is done.
[0023] The invention also features a method including aggregating discrete print jobs into aggregate print jobs to be produced on units of a common substrate, all of the aggregate print jobs conforming to a standard format, transmitting the aggregate print jobs to a printer electronically, and, at the printer, configuring printing equipment for producing different ones of the aggregate print jobs using the same steps.
[0024] In another aspect, the invention features a method including (a) defining a standard template format for containing common graphical information that relates to different discrete print jobs, (b) providing a design tool to enable a designer to create a template that complies with the standard template format and embodies the common graphical information, (c) enabling the designer to deliver the template to a server electronically, (d) enabling users at client machines to use the template to generate different discrete print jobs that conform to the template and include custom graphical information specific to each of the discrete print jobs, and (e) aggregating sets of the discrete print jobs into aggregate print jobs for printing at one time on units of shared substrate.
[0025] In yet another aspect, the invention features a method including aggregating discrete high-quality full color print jobs into a single aggregate print job, printing the single aggregate print job using standard process colors and standard un-pre-printed paper on high speed printing equipment, and distributing the aggregate print jobs in electronic files.
[0026] The invention also features a method including (a) digitally aggregating discrete print jobs into an aggregate print job to be printed at one time on units of a standard shared substrate, the aggregate print job being defined in a standard compressed prepress data format, (b) sending the aggregate print job to a workstation at a printing site, at the printing site, Raster Image Processing the aggregate print job to create standard color separations, (c) using a computer-to-plate process to create plates based on the color separations, (d) loading the plates onto a high volume press in accordance with a standard predefined protocol, (e) loading units of the standard shared substrate onto the press, (f) printing the aggregate print job onto the standard shared substrate, (g) cutting apart the standard shared substrate units to separate the discrete print jobs, and (h) forwarding the discrete print jobs to different customer destinations.
[0027] The invention also features a method including (a) aggregating discrete print jobs into a digital aggregate print job to be printed at one time on units of a standard shared substrate, the placement of the discrete printing jobs within the aggregate print job being defined by a digital aggregation template that represents the locations of cuts that will be needed to separate the discrete print jobs from the aggregate print job, (b) placing a physical embodiment of the aggregation template on the units of the standard shared substrate, and (c) using the physical embodiment of the aggregation template as a guide to making cuts to separate the discrete print jobs. The aggregate print job may include a plurality of aggregated sheets, and be identified by an identifier printed on each aggregated sheet within the aggregate print job. Information printed on the aggregation template may be used to automatically identify each discrete print job.
[0028] In another aspect, the invention features a method including (a) aggregating discrete print jobs into an aggregate print job, (b) printing the aggregate print job at a printing site, (c) separating the discrete print jobs by cutting apart the aggregate print jobs, (d) electronically identifying the discrete print jobs as having been completed using a print job identifier, (e) at the printing site placing the print jobs into shipment bins of a parcel carrier that tracks shipments electronically using a shipment identifier, (f) associating the print job identifier with the parcel carrier's shipment identifier, and (g) enabling customers of the discrete print jobs to track the progress of delivery of their discrete print jobs electronically.
[0029] In a further aspect, the invention features a method including (a) aggregating discrete print jobs of respective customers into an aggregate print job, (b) printing the aggregate print job at a printing site, (c) separating the discrete print jobs by cutting apart the aggregate print jobs, (d) electronically identifying the discrete print jobs as having been completed using a print job identifier, (e) shipping the discrete print jobs essentially as soon as they are printed, cut and packaged, (f) electronically billing the customers in response to completion of the printing and delivery of the discrete print jobs to a shipper for shipment.
[0030] The invention also features a method including printing an aggregate print job, cutting the aggregate print job apart to form different discrete print jobs, automatically printing shipping labels for shipping the different discrete print jobs to different respective customers, and applying the labels to the different discrete print jobs in accordance with identifiers on the labels.
[0031] In a further aspect, the invention features a method including (a) providing different kinds of entry ports into a print job execution system, each of the entry ports enabling a user to create interactively a full color print job in accordance with a pre-defined design template, (b) at each of the ports, generating a digital print job file based on the design template and design input of the user, all of the print job files being expressed in a standard design data format, (c) routing all of the digital print job files electronically to an aggregation system, (d) at the aggregation system, assembling selected ones of the digital print job files into aggregate print jobs, all of the aggregate print jobs being expressed in a standard prepress format, and (e) routing different ones of the aggregate print jobs electronically to different printers for printing.
[0032] The invention also features an apparatus that includes (a) web browsers configured for interactive design by users of discrete print jobs, (b) a central storage for information about the discrete print jobs that results from interaction with the users, (c) a scalable group of web servers that interact with the web browsers and with the central storage, and (d) a scalable group of printing servers configured to aggregate the discrete print jobs into aggregate print jobs and deliver the aggregate print jobs electronically to printers.
[0033] Among the advantages of the invention, short run print jobs can be printed using high-quality, large-volume printing equipment, while reducing printing cost significantly, improving print job quality as compared to alternative short run printing processes, and improving capacity utilization of the printing equipment. In some implementations, the printing cost is less than 10%, or even less than 5%, of the cost of printing an identical item using traditional short run printing techniques. Some implementations also provide a fast possible turnaround time from when the customer places an order until the customer's print job is done, e.g., less than two hours, and allow queuing of print jobs so that expedited print jobs are printed first and lower priority print jobs are printed later. A large number of customers with short-run print jobs can be served by a relatively small number of industrial print subcontractors, to achieve end-to-end automation and aggregation of the print jobs. Each customer can design a print job directly on a web browser and, if desired, upload the customer's own graphics, e.g., a logo design. Use of the web browser based design capability can replace or enhance traditional methods of graphic design, in which a graphic designer translates a customer's sketch and/or verbal description into a finished design and provides one or more proofs for the customer's approval prior to printing.
[0034] The invention allows the printing subcontractors' production floors to be organized and operated in a manner consistent with the best-in-class practices for high-volume, high quality publishing and packaging printers, despite the fragmented nature of the custom printing jobs involved. The invention also features a scalable systems architecture, to allow the systems of the invention to accommodate higher volumes of customers and/or printing jobs. Based on real time information provided by printers, order flow can be redirected to those printers who, at a given moment in time, have excess production capacity and are willing to sell that capacity at a price lower than their “fully loaded” production cost.
[0035] Customer orders can consist of a variety of document types, layouts and quantities, for a potentially infinite range of order characteristics. Yet the traditionally high cost of managing this variability of order characteristics is reduced or eliminated through a conversion of the variability into a consistently formatted, repetitive stream of pre and post press digital information that is compatible with printing industry standards. Groups of customers (e.g., multiple customers within a single company) are able to share and centrally control common document characteristics (e.g., a template for a brochure layout or a business card design that is shared by multiple persons within the same company), while decentralizing individual purchase decisions, order entry and modifications to text or other variable elements within the documents.
[0036] Based on market information and printer information, received both previously and in “real time”, the web server host can modify the price, delivery, and product options that are offered to a given customer or set of customers. For instance, if excess production capacity will be available in the next several hours, printers may be willing to temporarily cut their wholesale price in order to fill the near-term capacity, and the web server host could, in response, immediately modify the offers displayed to customers via the Internet so as to increase demand. There is no incremental (marginal/variable) cost to processing a customer's order in a very rapid time (e.g., two hours), and the system allows real time rescheduling of order queues to manage capacity fluctuations. This allows the web server host to charge a higher price for expedited orders without incurring additional cost to provide the expedited service.
[0037] Other features and advantages of the invention will be apparent from the description and drawings.
DESCRIPTION OF DRAWINGS
[0038] [0038]FIGS. 1, 1A, and 1 B are schematic block diagrams of a system according to one implementation of the invention. FIGS. 1A and 1B are the top and bottom halves, respectively, of one diagram.
[0039] FIGS. 2 - 2 A are schematic top views of layouts of print jobs.
[0040] [0040]FIG. 3 is a flow diagram illustrating the designing of a print job on a web browser.
[0041] FIGS. 4 - 4 W are webpages according to one implementation.
[0042] [0042]FIG. 5 is a schematic diagram showing connection of elements of the system.
[0043] [0043]FIG. 6 is a flow diagram of a printing and post-press process.
[0044] [0044]FIG. 7 is a schematic diagram showing the farm configuration of servers in a system according to one implementation.
[0045] [0045]FIG. 8 is a schematic diagram showing a queue processing system.
DESCRIPTION
[0046] Implementations of the invention include interrelated elements. These elements and their relationships will first be discussed briefly and then later in more detail.
[0047] An implementation of a print job management system 10 is shown schematically in FIGS. 1, 1A, and 1 B. A potentially enormous number (e.g., thousands or even hundreds of thousands or millions) of individual and commercial customers 12 , wishing to place orders for discrete print jobs (generally short run printing jobs, i.e., jobs of less than 40,000 units, typically 250-5,000 units), access the Internet 14 via web browsers 13 (or similar interactive communication software) running on personal computers or other electronic devices 11 . Customers can access the system through any one of several different types of entry ports 15 into the print job management system, where some types of entry ports may be characterized by their economic and market characteristics. The types of entry ports could include home office/small office computer entry ports 1 Sa, intermediary ports (such as boutique stationery stores) 15 b , and large corporate entry ports 15 c (such as a Communications Department of a large corporation). Other entry ports need not be based on web browsers, but could be, for example email links 15 d and dial up voice telephone lines 15 e . The system can also be integrated with bidding systems or “eHub” bidding sites such as Noosh, Impresse, Collabria and Ariba (eHub portals 15 f ). The term “print job” refers to an individual print job, such as a single design version of a brochure for a business in a given quantity such as 1000 brochures. The term “order” is used to refer to a group of print jobs that are ordered at the same time, such as a business card, letterhead, and envelopes for a business. For some customers, individual print jobs could be part of a large corporate communication program that would include hundreds of different documents each bearing common graphic elements and custom text associated with each document.
[0048] Through the Internet 14 , each customer can access a website 16 , that includes a website studio 16 a which provides design software that is made available from a central web server 18 . The website studio, which will be discussed in further detail below, allows each customer to design one or more custom printing jobs, e.g., business cards, brochures, postcards, folders, letterhead, and envelopes. The customer chooses from a limited selection of standardized papers, formats (provided to the user in the form of templates with user-specified data fields), colors and quantities. The website studio software is downloaded from the server as part of web pages displayed to the user, runs on the user's browser, and enables the user to perform simple design functions by completing a selected template using a Design Wizard, or more complex design functions using a Design Studio, locally on his browser. Typically, only the results of the design process are uploaded to the server as a print job. The templates are created using an XML format or other appropriate format. Alternatively, a customer or a professional designer could generate his own template, using the website studio itself, or using desktop publishing software, and upload it to the server website studio.
[0049] As shown in FIG. 1, two kinds of data pass back and forth between the customers and the system, and there are two series of processes that handle this data. The data can be categorized as graphical print data 115 (in FIG. 1, graphical print job data 117 , templates 119 and web studio software 121 ), and commercial print job data 123 . Processing of this data is split into two pieces: what goes on between the customers and the system, shown in FIG. 1A, and what goes on between the system and the printers, shown in FIG. 1B. As shown in FIG. 1 , there is storage at various points in the system to store the data. For example, some of it is stored in the customer's PC storage 111 , some in the system's data storage 20 / 22 , and some at the printer data storage 113 .
[0050] The system's data storage is shown in more detail in FIG. 1A. The data input by a customer when an order is placed is stored in a central database 20 and/or a network storage 22 , depending on the nature of the data, as will be discussed below. The network storage 22 stores all of the graphic files that define a print job, e.g., logos, fonts, backgrounds, layouts and frame designs, while the central database 20 stores, among other things, all of the non-graphical information, e.g., the text to be printed and the business information that is needed to get the jobs printed and delivered. The central database 20 also stores information regarding the customer, e.g., the customer's name and address, and stores the non-graphical elements of the website studio templates (the graphical elements that are stored in the network storage are referenced by the templates and document layouts).
[0051] Once the customer has finished designing the print job the customer places an order, e.g., using a Purchase Wizard 16 b , as discussed below. The customer's print job is sent to the server in XML format, and the XML file is then converted by the server into a digital format, e.g., into a PostScript file 128 (FIG. 1B). The backend printing servers 28 then automatically aggregate, or “gang together”, the customer's PostScript file with multiple PostScript files from other customers to produce a consolidated print sheet (a “layout”). To achieve this, the backend servers assemble the individual PostScript files to create the layout 130 (FIG. 1B), with different individual print jobs arranged on respective portions of the layout. For example, as shown in FIG. 2, 133 different business card print jobs 50 of identical size could be aggregated into a layout and printed on a single large printing sheet 52 , e.g., a large format printing sheet measuring 1.0 meter by 0.6 meter. In other examples, different sizes and shapes of print jobs can be aggregated, e.g., as shown in FIG. 2A and discussed below. The organization of the different print jobs on the layout 130 is defined by aggregation templates that characterize where cuts need to be made after printing in order to separate the different print jobs. The choice of which print jobs to place onto a given layout and in what arrangement is discussed below.
[0052] The commercial information related to the customer's order (e.g., the shipping address, shipping date, etc.) is stored in a customer information file 132 (FIG. 1B). The customer information file 132 is aggregated with other customer's files (the same customers whose PostScript files have been aggregated onto the layout), to create an aggregate meta file 134 which contains all of the commercial information for the customers' print jobs. The aggregate meta file 134 also includes commercial information relating to the printing run, e.g., a batch number (“template layout reference number”), the number of sheets to be printed, and the cutting template to be used to cut the printed sheets into individual printed print jobs.
[0053] The aggregate meta file is posted by the backend server to a website 136 that is accessible to printing firms 138 wishing to sell their printing services to the web server host. The aggregate meta file 134 includes the commercial details of the print run that will be performed using the PostScript layout file 130 (e.g., number of sheets, type of paper, and deadline). As will be discussed below, printing firms with unused capacity bid for a contract to print the print run. Generally, the contract is automatically awarded to the bidder providing the most competitive bid based on predetermined criteria, e.g., lead time, quality, history, price or other factors. The successful bidder's contractual obligations, and the PostScript layout file and aggregate meta file, are then transmitted by the backend server to that printing firm, e.g., to a server 32 located at the printing site.
[0054] The PostScript layout file is converted at the printing facility 29 , during RIPing (Raster Image Processing), to the color separated prepress format that is used by standard computer-to-plate systems that produce four-color photolithographic plates 110 (FIG. 1B) for use on automated large scale offset printing presses 30 . By large scale offset printing presses we mean either (a) sheet-fed presses with sheet formats of 530×740 or larger and straight printing rates of 12,000 sheets per hour or higher, or (b) web presses with roll widths of 20 inches or higher and printing rates of 40,000 iph (inches per hour). Large scale offset printing presses include, e.g., Heidelberg, Speedmaster, and other similar or larger printing press production systems.) The server 32 provides a browser interface for use by people who operate the printing presses (“print operators”). Information about how to set up and perform each of the print runs is provided in a simple format to the print operators through the browser interface, as discussed below. The plates are used to print a desired number of copies on a standard printing paper that is loaded by the print operator using standard four-color process inks, based on meta file information that is provided by the backend printing server to the operator on a web-browser based computer display 32 at the operator's station.
[0055] The printed sheets are then transferred to a cutting station 140 (FIG. 1B), where they are cut and sorted into individual print jobs 142 , as will be discussed below. In some implementations (such as for presentation folders or envelopes) additional post-print processing is performed such as folding and/or gluing. The orders are then immediately shipped to the respective customers, using shipping information that is displayed on a computer display 34 in the shipping area of the printing facility.
[0056] Most customers “pre-pay” (e.g., provide their credit card billing information) upon placing their orders. Some corporate customers may be invoiced. Generally, the customer's credit card is not debited until after the customer's order has been shipped. The backend printing server sends a meta file 144 back to the web server after a shipment has been made, informing the web server of the status of each customer's order. Once an order has been successfully shipped, the backend server interacts with a processing center 146 so that the customer's account will be debited, or, in the case of a corporate customer, sends the corporation an invoice.
[0057] Customer Interface with the Internet
[0058] The only requirement for use of the print job management system by a customer who is accessing the system through one of the types of browser-based entry ports described above is a computer that is linked to the Internet by a standard recent web browser, e.g., Microsoft Internet Explorer 4.0 or higher. The customer accesses the website 16 by entering the website URL address into the browser. Other entry ports do not even require that the customer have access to a browser, e.g., a dial-up voice telephone link 15 e could be used to enter information by voice or punching keys on the telephone keypad.
[0059] The design and order process is conducted through the website. The rest of the system is “invisible” to the customer. The customer's order is printed and delivered to the customer without any requirement for further interaction, although the customer may use the website to track the progress of the order through the printing process and the shipment of the order to the customer.
[0060] The Website Studio
[0061] The website studio allows the customer to design his own print job, using the browser for design selection and editing. The website studio uses a user-friendly “what you see is what you get” (“WYSIWYG”) functionality that allows the customer to choose a base design for a desired printed item (e.g., business card or stationery), and then edit the design. The functionality is similar to that of existing desktop word processing publishing products, making the website easy for most customers to use.
[0062] As shown in FIG. 3, using the browser and the Design Wizard portion of the website studio the customer can choose a printed item from a wide selection (e.g., business cards, letterhead, invitations, brochures and marketing materials), choose basic options such as page orientation (portrait or landscape), view a variety of design templates that are available for the item and choose one, complete the template (e.g., by supplying new text, uploading graphics files and adjusting fonts), and save the resulting design. The customer can then add the item to his shopping cart, place an order, or perform further design modifications using the Design Studio portion of the website studio. The design process will be described in further detail below with reference to FIGS. 4 - 4 O. Once the customer is satisfied with the design, the customer can add the design to his shopping cart as a print job, and use the Purchase Wizard, discussed below with reference to FIGS. 4 P- 4 W, or other purchase function, to place an on-line order and pre-pay for the order over a secure connection.
[0063] The customer is offered a relatively limited selection of standard papers, to allow easy and cost efficient aggregation of print jobs and printer set-up, as will be discussed below. Customers also select from certain predetermined print quantities, e.g., multiples of 250 units (250, 500, 1000, etc.).
[0064] The procedure described above would be followed by a customer entering the system from his individual PC. If other entry ports are used, for example an intermediary port 15 b , some of these steps may be bypassed, e.g., the customer may not use a Purchase Wizard to place and pay for the order.
[0065] FIGS. 4 - 4 O show webpages from a website studio used in one implementation of the invention. To begin the design process, the customer first navigates from a home page (not shown), to the Design Wizard (FIGS. 4 - 4 E). The Design Wizard is configured to appear to the customer like a standard Windows® Wizard application, e.g., with “back”, “next” and “finish” buttons, giving the customer a feeling of familiarity and user-friendliness. In the Design Wizard, the customer selects the item that the customer wishes to design (e.g., business cards or other items, in FIGS. 4 - 4 E). For business card design, the Design Wizard includes a Welcome screen (FIG. 4), an Orientation screen (FIG. 4A) that allows the customer to choose between horizontal and vertical cards, a Template Browser screen (FIG. 4B) that allows the customer to choose between a variety of different design templates (not shown), an Information screen (FIG. 4C) at which the customer fills in a number of fields to complete the selected design template with the customer's information, and Review screens (FIGS. 4D and 4E) that allow the customer to review the front and back of the resulting business card. After reviewing the card, the customer can decide to (a) go back and edit the card, (b) go to the Checkout (the Purchase Wizard described below), or (c) go to the Design Studio to perform more complicated design functions (e.g., changing fonts and color schemes).
[0066] A Design Studio used in one implementation of the invention is shown in FIGS. 4 F- 4 O. When the customer opens the Design Studio, the customer will first see an initial screen (FIG. 4F) with a loading bar, indicating the status of the downloading of the Design Studio to the customer's browser. Each time something (e.g., a font) is downloaded to the customer's browser from the web server, a similar loading bar will be provided. The Design Studio is configured to have toolbars and other features that are similar to those used in standard word processing and desktop publishing user interfaces, so that again the customer will have a feeling of familiarity with the software and will find the software easy to use. In the case of the loading bar, the user is comfortable with the notion that the application is loading even though it is not being loading in the usual sense of being moved from a hard disk to memory in the user's computer. The Design Studio also includes a standard “Startup Tips” dialog box (FIG. 4G), like other Windows® applications, and a Help system.
[0067] In the Design Studio, the customer can select a background from a variety of choices (FIG. 4H), use a “picker” dropdown list (FIG. 4I) to select other design features (logos, card layouts, color schemes, designs and fonts), modify those design features, add a logo (FIG. 4I), select a color scheme (FIG. 4J), change the color of selected text (FIG. 4K), change the properties of an image, e.g., the logo (FIG. 4L), view the backside of the card (FIG. 4M), and preview exactly how the front and back of the printed card will look (FIGS. 4N and 4O). The Design Studio features in-place editing, i.e., the customer can double-click on an item and change it directly. While in the Design Studio, the customer can make as many modifications to the fonts, colors, card layout, etc., as desired. The customer can also choose to view the design at low resolution, medium resolution or high resolution. In some implementations, the customer can add text or graphics to the back of the card, in which case in most implementations the existing “advertisement” text is automatically removed and this removal is automatically chosen as a purchase option in the Purchase Wizard. The customer can also choose a blank back side as a purchase option.
[0068] If desired, a customer using the Design Studio can upload a graphic file, e.g., containing the customer's logo. The file can be, e.g., created using graphic design software, downloaded from the Internet, taken with a digital camera, or scanned in with an image scanner. Generally, the file should have a relatively high resolution, e.g., at least 300 dpi. Most standard graphics file types are supported. The customer's graphic file is stored in network storage 22 , and is referenced by the XML file created by the customer in the website studio and added to the PostScript file for the customer's print job when the PostScript file is created.
[0069] When the customer is satisfied with the design of the card, the customer can proceed to the checkout (the Purchase Wizard), or can save the finished design (the customer's print job) for later purchase. In either case, the customer's print job is saved in XML format in the central database 20 . The XML file includes the size and orientation of the document, the number of pages, and, for each page, the margins, background, frame design (if any), and the text and graphics elements on the page and their characteristics (color, font, size, etc.).
[0070] The website studio is designed for use by customers who have no graphic arts experience or specialized software knowledge, e.g., small business owners who want to “do it all” and workers in companies whose goal is to update information, such as the company address or telephone number, prior to ordering or reordering printed materials.
[0071] For users with graphic design experience and desktop publishing software, the web server provides a full toolset that is compatible with leading desktop publishing software such as Quark Express and Adobe InDesign software. Thus, a print job can be designed by a graphic artist, using professional desktop publishing software, and then uploaded to the web server for distributed access to other users at the customer company. For example, the graphic artist can define fixed and variable fields, and an administrator or other designated employees at the company can then be given access to input information (e.g., company address and telephone) into the variable fields, without changing the fixed fields (e.g., the overall design and graphics of the print job). As a result, customers having access to desktop publishing software can create their own templates, rather than being limited to the templates offered by the web server host. When the template is uploaded to the web server, it is split into graphic data (logos, fonts, backgrounds and designs) and all other data. The graphic data remains in its original format and is stored in network storage 22 , as discussed above. The remaining data and layout information is converted to XML format and stored in the central database 20 .
[0072] Unlike other previous, server-based approaches, the website studio utilizes browser-based processing to allow high-speed processing when the customer is working interactively to design a print job. The website studio utilizes Javascript and DHTML technologies for the graphic design by the customer, i.e., the web pages that the customer receives and views include not only the static visual display, but also graphic design programs (the website studio) that will run on the customer's browser just as any other application runs on a computer. Thus, the customer can use the browser interface to do graphical design without interacting with, and thus consuming the resources of, the web server.
[0073] So that the website studio can be quickly downloaded by the customer, in most implementations the graphic elements, e.g., fonts, backgrounds and logos, used in the website studio are stored in a library in the network storage 22 , a copy of which is stored at the printing firm information system 29 , as will be discussed below. Thus, a graphic element need only be downloaded by the web server to the browser when it is selected by the customer during the design process. The XML file that results from the design process (the customer's print job) will reference the appropriate information in the centrally stored library. The library is replicated at the printing firms, so that the graphic elements can be inserted during RIPing using OPI (Open Prepress Interface) techniques. The library can be distributed periodically using a CD-ROM publication or other distribution approach so that all parties to the system are working from the same library.
[0074] Post-design processes, such as high resolution proofing and processing files, are queued separately and processed by the backend servers independently of the web server, because the customer is not waiting for these processes to be completed and thus processing speed is not a concern.
[0075] The web studio may also include a dynamic shopping cart, which allows the customer to access the shopping cart at any time during the design process to add or delete items.
[0076] The web studio application is based on modules, to provide an open development architecture. Different modules are plugged into the core libraries to provide additional functionalities, e.g., the Undo/Redo History Manager is a separate module that could be deactivated, by removing a few links, or replaced by a new and more powerful module complying with the same architecture as the current module.
[0077] The web studio application uses style sheets to “style” the interface into a usual Windows® like interface. Using style sheets allows the application to have a smaller overall size, as styling policy is centralized in a few modules that are reused in the application's web pages. Providing a centralized styling policy also allows the web server host to change the look and feel of the web studio interface at any time, just by changing the styles.
[0078] In one implementation, the modules use Internet Explorer XML DOM implementations. Using these functionalities, a real-time renderer can be created which will take any XML document and, using XML style-sheets (XSL) transform the document into a WYSIWYG preview. The use of these integrated functionalities allows a small and fast rendering/edition engine.
[0079] Using HTCs (HTML components), scalability and processing speed can be enhanced. Also, the web studio application can be designed to behave differently on the result of the XSL transformation, just by using a different previewing style sheet (CSS). Thus, after rendering, the resulting preview can be a simple “flat” preview, or an editable document that the user can interact with.
[0080] If the XML Document model is extended to VML (Vector Markup Language), the web site studio is then able to render documents created by most common office applications, e.g., Microsoft Word. The user can then modify such a document and send it to the webserver for printing. This feature enhances the compatibility of the web studio with usual Windows® applications. Extension of the XML document model to VML also allows the web studio application to draw more complex shapes (e.g., ovals, rounded rectangles and curves), apply color gradients and color schemes to complex objects, and use transformations, making it possible for a user to design and print complex documents to suit his or her needs.
[0081] The Purchase Wizard
[0082] A Purchase Wizard used in one implementation of the invention is shown in FIGS. 4 P- 4 W. Like the Design Wizard, the Purchase Wizard appears to the customer as a standard Windows Wizard application. The Wizard may be configured to run on the user's browser, or on the web server, depending on the preference and resources of the web server host. The final purchase information is transmitted over a secure server connection. The Wizard includes a Welcome screen (FIG. 4P), a Review screen (FIG. 4Q) that gives the customer a final opportunity to review the design, an Address screen (FIG. 4R) that allows the customer to input a shipping address and select an order quantity, one or more Options screens that offer the customer choices of upgrades, e.g., to remove the advertising text on the reverse side (FIG. 4S), a Delivery screen (FIG. 4T) that allows the customer to select delivery options, e.g., expedited delivery, a screen that notifies the customer that the order is being submitted to the server (FIG. 4U), a Billing Information screen that allows the customer to input billing information (FIG. 4V), and a Payment Confirmation screen that asks the customer for final confirmation of the order.
[0083] Once an order has been placed, the server stores the customer's order information into the central database 20 , including the commercial information regarding the customer's order.
[0084] In some implementations, relatively low cost items, e.g., business cards, are offered to customers by the web server host at no charge. The cost of printing these items can be recouped by the web server host by charging a fee for upgrades, e.g., faster delivery, and sales of complementary items such as business card cases. For example, as discussed above, the web server host may include an advertisement (e.g., “Free Business Cards at www.vistaprint.com”) on the back of each free card, and charge a fee if the customer does not wish this advertisement to appear on the customer's cards.
[0085] For all orders, the web server host may, if desired, charge additional fees for enhancements such as expedited service and gloss or other special finishes.
[0086] Customers can obtain support through the website by visiting a FAQ (“frequently asked questions”) or help page (not shown). In some implementations, the website will also offer interactive online support, support via email, and/or a toll-free number that customers can call for telephone support. If desired by the website host, access to interactive online support, email and telephone support may be restricted to certain preferred customers, e.g., corporate customers having accounts with the website host. Alternatively, the website host may offer these services to all customers at no charge or may charge a fee for access.
[0087] As discussed above, the customer can access the website studio using his own computer and browser, or can use another type of entry port, e.g., an intermediary port 15 b (such as a terminal at a boutique stationery store), or a large corporate entry port 15 c (such as a Communications Department of a large corporation). The entry port need not be based on a web browser, but could be, for example, an email link or dial up telephone line. The customer may use the website studio without assistance, or may describe the desired print job to someone else, e.g., a graphic designer or salesperson at the boutique stationery store, who will use the website studio to design the print job.
[0088] The Web Server
[0089] In some types of entry port, the web server provides the interaction of the customer with the web studio. The web server uses a typical three-tier architecture to respond to all of the customer page requests, by using server-side scripting to access server objects that implement the business logic, these objects in turn interacting with the central database and network storage to access the necessary data.
[0090] Data Storage
[0091] Hundreds of thousands (potentially millions) of customer relationships are managed by the system. Each customer order typically involves a relatively large file due to the nature of color graphic printing data. The data storage capacity of the system is robust enough to handle high levels of data storage and data access. The data storage is also capable of acting as a link between the front end at which orders are placed, the design studio, the backend printing servers, and shipping, accounting and marketing systems. A data storage system that is capable of meeting these requirements is an Oracle RDBMS running on a Unix box or a Microsoft SQL Server 7 .
[0092] All data is stored in either the central database 20 or the network storage 22 . Stored data includes business-related information such as information pertaining to customers and orders, and design data specific to each customer's print job.
[0093] Network storage 22 includes one or more network attached storage (NAS) systems, and is configured to store all graphical objects that are used by the Design Wizard and Studio and that are uploaded by customers, including logos, backgrounds, fonts and frame designs.
[0094] The network storage includes a library, which contains all of the backgrounds, logos and fonts that are used by the Design Wizard and Studio. Customer uploaded information is not stored in the library. The library is replicated and sent to each of the printing firms used by the system for print runs, and the contents of the library are referenced by the PostScript layout files sent to the printing firms. The network storage may also contain the web pages used in the website 16 .
[0095] A very large amount of data is stored in the network storage 22 , e.g. up to several terabytes depending on the number of customers using the system. The network storage 22 is completely server independent (it includes its own enclosed CPU) and is directly connected to the local area network (a local area network internally operated by the web server host, including the web servers, the backend servers, and the storage devices), making the stored data available to connected servers, i.e., the web server(s) 18 and the backend printing servers 28 . As of the writing of this description, a single NAS system can typically handle from 20 gigabytes to one terabyte of data. Thus, as data space needs increase more disks can be added to the NAS (this operation typically does not require a service shutdown), or, when the limit of each NAS is reached, an additional NAS can be added to the system. As shown in FIG. 5, the web servers, central database, and backend servers are connected to the network storage by an Ethernet.
[0096] Central database 20 is a relational database management system (RDBMS) that handles all non-graphical data. This database is designed to handle millions of records. As is customary, the data is organized in tabular form. In one implementation, the database includes the following tables, which include the listed fields. (More, fewer or different tables may be used in other implementations, as needed.)
Table Fields Products unique product (item) ID (i.e., the SKU #) and name, product description, list price, weight (for shipping) Print Jobs unique print job ID and name, XML content of print job, SKU # of item (card, envelope, etc.), creation date, last modification date Templates unique template ID and name, XML content of template, SKU # of item (card, envelope, etc.), creation date, last modification date, template category Template Categories unique category ID and name, parent category ID (tree structure), category graphical representation Shoppers unique shopper ID, shopper name, number of logins, last login date, email address/login ID, password Orders unique order number, reference to shopper ID, order date, pricing and tax information, status of order, credit card authorization number, shipping method, shipper tracking information, customer shipping and billing information including priority of order Ordered Items ordered item number, order number (from orders table), SKU # of item, quantity, pricing information, print job ID Shopping Carts Same fields as Orders, but temporary storage Shopping Cart Items Same fields as Ordered items, but temporary storage Printer Batches batch ID number, date sent, status, printer ID number and name, (Layouts) quantity of print run, action to be taken when layout is created (none, notify print operator, send layout to printer, notify and send) Printer Batch Items batch item ID number, ordered item number (from ordered items table), batch ID number (from printer batches table), status of item
[0097] Data stays in the database as long as it is needed by the system. Data is maintained in the Orders table after a customer's order has been completed and shipped, to facilitate reordering. To avoid overloading the database, the web server host may place a time limit on reordering, or charge the customer a nominal fee for keeping his information in the database for an extended period of time.
[0098] Each time a layout is created, an entry is created in the Layouts table. Depending on the action to be taken, the print operator may be notified by email, or an extranet query can be set up to query the table, or a process may be running at the printer that checks the table for new layouts.
[0099] The following status codes may be used in the “status” field in the Orders table:
Status Code Value Status description ST_READY 0 The order has been submitted by the customer but at this point has not been processed. ST_PROCESSING 1 This order is being processed. ST_CANCELLED 2 This order has been cancelled. ST_REPEAT 3 There was a problem with this order so it has been re-submitted. This code is treated by the system in the same way as an “unprocessed” order. (Re-submitted orders can only be re-submitted a few times before a warning is raised) ST_DISPATCHED 4 This order has been dispatched and the tracking information has been updated. ST_COMPLETED 5 The customer's credit card has been charged. This order has now been completed.
[0100] Order Queuing, Prepress Aggregation and Data Conversion
[0101] Prepress aggregation is performed by a prepress aggregation module of the backend printing server, which includes a multi-user PostScript file creator, shown as item 200 in FIG. 8. The file creator collects all of the print jobs that have been received by the web server and queued for printing. The file creator includes four queue-processing components, as follows. The first component 202 creates individual PostScript files 204 for each customer's design, and individual meta files 206 , referenced to each customer's PostScript file, that contain job tracking information and other commercial information related to the customer's order. The second component 208 collects these PostScript files, according to aggregation parameters (e.g., job tracking information and size of the printing paper to be used), and aggregates (or “gangs”) them to produce a PostScript file 210 that contains “N-up” designs, the value of N being dependent on the design size, the paper size, and the exact layout required due to requirements such as edge bleed. The third component 212 does an automatic “pre-flight check” on each aggregated PostScript file, thus avoiding the need for further manual intervention. The fourth component 214 optimizes production scheduling and routes the final aggregated PostScript file to a Raster Image Processor (RIP) 220 at the printing cell.
[0102] The print jobs are arranged spatially on the master, rather than in chronological order. As a result, several types of items can be aggregated and arranged on a single layout, e.g., postcards, invitations and business cards. For example, as shown in FIG. 2A, the layout can include business cards 50 , postcards 53 and invitations 55 . If any of the aggregated print jobs are to be printed on both sides, the entire layout will be printed on both sides, with blank areas for any print jobs that are printed only on one side. Some items, e.g., envelopes, generally cannot be aggregated with other types of items because of their specific post-press processing requirements.
[0103] Aggregation may be performed in accordance with one of a number of standard aggregation templates, as noted above, or can be done “on the fly”, in any arrangement that will fit within the bounds of the paper sheet to be printed. The prepress aggregation module, a rules-based program, aggregates print jobs by scanning the Ordered Items table of the central database and searching for items (print jobs) that have the same printing requirements, e.g., the same delivery date, paper grade, and post press processing requirements. Scanning generally continues until enough print jobs have been located to fill a layout of a given size. The XML files corresponding to the selected print jobs are then pulled from the Document Table, converted to PostScript files and aggregated, as discussed above.
[0104] Printing is generally performed in a base print run of a standard number of sheets, e.g., 250 sheets. The prepress aggregation module automatically deals with a print quantity that is greater than the number of sheets in the base print run by allocating that print file to one or more extra position(s) on the consolidated sheet (master). For example, if the base print run is 250 sheets and a customer orders a print quantity of 500, the customer's design would occupy two positions on the master, whereas if the customer orders a print quantity of 1000 four positions would be occupied. The prepress aggregation module is also able to differentiate between these different quantity orders, and thus when sufficient order volume is being generated at, e.g., 500 units, the module will create a print file with each order occupying only a single position and increase the base print run to 500 sheets, further reducing unit cost. Also, in the unlikely event that insufficient orders are received over a period of time, one or more position(s) on the master may be left blank.
[0105] In some implementations, the prepress aggregation module is configured to provide digital management of queues to allow a customer to choose to have his order expedited for an additional cost. Expedited orders are queued ahead of non-expedited orders, so that non-expedited orders will be printed later, e.g., 5-7 days later, than expedited orders which are printed immediately. As a result, all orders can be shipped immediately after printing, without the need for the printing firm to sort out and hold back non-expedited orders. If there are a few particularly high priority jobs waiting to be printed, the program with aggregate these jobs and send them to be printed immediately, without waiting for enough orders to be received to fill a layout.
[0106] The Backend Printing Interface
[0107] The backend printing servers do not interact directly with the customers. The backend printing servers do the processing (e.g., print job aggregation and printer preparation and optimization) that occurs after the customers have designed the print job and placed orders. Generally, communications between the backend printing servers and the print subcontractors are handled over dedicated leased lines due to the high volume of real-time data transfer from the backend print servers to the print production floor.
[0108] After the print jobs have been aggregated and queued by the prepress aggregation module, as described above, the resulting layout and aggregate meta file are sent by the backend printing servers to designated printing firms. The printing firm to which the data is sent may be selected by an automated bidding process, which will be described below. The digital data is then used to make color-separated offset printing plates in accordance with the layout. The printing plates are generally prepared in advance of the time allotted for the print run, e.g., the layout and meta file are sent at least an hour before the scheduled print run and the plates are formed immediately (plate forming generally takes about 10-15 minutes or less).
[0109] Once the printing plates have been formed, the operator of the printing press loads the specified grade and quantity of printing paper for the aggregate print run, e.g., 250 sheets plus “overage” for a 250 sheet run of business cards. For this purpose, the operator refers to a browser-based terminal at his work-station, which displays information from the meta file concerning the print run. The print run is then performed, resulting in the desired number of printed sheets, e.g., a stack of 250 printed sheets for a 250 sheet run. The system can organize multiple aggregate print runs that use the same paper base, thus eliminating the need for paper changes.
[0110] Post-Press Processing
[0111] Referring to FIGS. 1B and 6, there are several steps that take place after a print run. These steps include cutting, post-forming (in some cases), sorting, packing and shipping. These steps are described in detail below.
[0112] Print jobs that are part of an order (e.g., letterhead) can be held until other print jobs that are part of the sane order (e.g., envelopes) are ready. (In some cases, the different parts of a customer's order may be printed at different printers, in which case they will be shipped separately.) In some cases shipments may also be tracked and customers informed of the location/status of their orders.
[0113] Cutting and Forming
[0114] To cut the stack of sheets into individual customers' print jobs, the operator selects an appropriate template by again referring to the terminal information, and/or by referring to a batch number (or “template-layout reference number”) on the printing plate or printed in the margin area of the printed sheets (e.g., a bar code 51 , FIG. 2). The sheets are moved, as a stack, to a cutting station (e.g., a guillotine cutter), the template is placed on top of the stack of sheets, and the operator enters the template-layout reference number into another terminal to program the guillotine cutter (or the template-layout reference number is automatically downloaded to the terminal). The guillotine cutter then cuts the stack of sheets, forming individual stacks of items (e.g., business cards, postcards, etc.). In high volume applications, the guillotine cutter can be replaced by automatic cutting or blanking equipment such as is used for cutting labels. While a guillotine cutter is used for most items, e.g., business cards, postcards, and other flat items), some items will require other post forming processes. For example, envelopes are formed using standard envelope forming equipment, including a hydraulic die cutter and an envelope folding and gluing machine. Because the folding and gluing machines generally require relatively high volumes (e.g., 150,000 units or more), it is necessary to accumulate the printed sheets from print runs until the necessary unit volume is reached. In order to keep track of individual print jobs, a marker is placed between each print job and the following print job. This can be accomplished, for example, by using a heavy, brightly colored cardboard sheet as the template, resulting in a brightly colored, sturdy marker at the top of each stack of printed items in a given order. The stacks of items can then be stacked and set aside, or transferred directly to the envelope folding and gluing machine and left there until there are a sufficient number of sheets to operate the machine.
[0115] Other items that require post-processing, e.g., folders, are processed using appropriate cutting and post-forming techniques, which are well known.
[0116] Sorting and Shipping
[0117] After cutting is completed, an operator refers to simple instructions displayed by a terminal, indicating how to package the items. The instructions also indicate whether certain stacks of items should be set aside until a subsequent print run has been completed, e.g., if a customer has ordered both business cards and letterhead stationery.
[0118] Shipping labels will be printed automatically by a printer attached to one of the browser-based terminals, allowing the operator to easily label the packages for shipping. The labels will generally include a bar code to facilitate shipping using optical-reader based systems, e.g., as used by UPS and FedX carriers. When these carriers are used, the information scanned in by the optical reader can be used by the web server host to track the location of a shipment and, if desired, to inform a customer of the location and/or status of the customer's order. After an order has been packed and labeled, the operator can simply drop it into a carrier's bin (e.g., a UPS bin) on site.
[0119] As discussed above, most customers will have pre paid during ordering, while some corporate customers will have accounts with the web server host, allowing invoicing and later payment. Debiting and invoicing of customers is conducted by the backend server upon receipt of a meta file from the printing facility indicating that orders have been successfully shipped.
[0120] The printing facility and carrier are paid by an automated accounts payable management system after printing and shipping have been successfully completed.
[0121] System Scalability
[0122] Referring to FIG. 7, while a single web server is shown in FIG. 1 for clarity, the system will generally include more than one web server to accommodate a very large volume of users. For example, for volumes of up to around 2 million visits a month, the browser-based processing of the system allows for a small, dedicated print-processing server farm of fewer than 5 servers. The system may be scaled to accommodate many times this amount of visits simply by adding more servers.
[0123] The servers are arranged in a “web server farm”, i.e., all of the servers used are strictly identical, and the system architecture is implemented so that additional customer requests, that cannot be handled by the existing servers, can be handled by simply adding an extra identical server to the farm. The backend printing servers 28 are also arranged in a farm configuration.
[0124] In a farm configuration, the load is split between the available servers, so that if more servers are needed either due to overloading of the system or due to a server breaking down the load will continue to be split proportionally among the servers after one is added, removed or replaced.
[0125] Automated Bidding Exchange for Printing Services
[0126] As shown in FIG. 1, the web server host has supplier relationships with a number of printing firms that are equipped to receive digital data (layouts) and informational data (meta files) from the system servers. The system includes a program that includes a digital database containing the meta files for each layout. The program fills customer orders by purchasing printing services based on automated real time bidding of commodity costs (i.e., paper and ink costs and/or depreciation). The printing firms bid for near-term printing services based on the capacity utilization of the printer at the time the printing services are needed, by accessing certain parts of the program via the Internet. For instance, if a printing firm anticipates a near-term situation of unused capacity, the printing firm will generally price that time period at just above marginal (commodity) cost. The program selects the most attractive bid from among the printing firms and transmits the digital data to that firm. The directing and redirecting of capacity can be done up to the very moment of production release.
[0127] The program may be configured to award a printing contract to the printing firm that is the lowest bidder, or to award the contract based on a group of selection criteria, e.g., quality, lead time, price, and history.
[0128] The printing firms may enter into the bidding process through a website operated by the web server host, e.g., by posting information regarding one-time availability, by posting information regarding long term availability (e.g., that a certain time slot is available every day or each week), or by responding to information regarding layouts that has been posted by the web server host. In some implementations the web site is configured so that a printer will only see information pertaining to layouts that could be printed by that printer (i.e., the printer will not see information pertaining to layouts that are in a format that is larger than the format the printer's press can accommodate.)
[0129] In some cases, the bidding process will be bypassed entirely. For example, if the web server has a layout that is particularly suitable for a specific printing firm, and the web server knows that the printing firm is available to print the layout, the web server may send the layout and meta files to the printing firm without putting the layout up for bidding by other firms.
[0130] Implementations of the invention involve a division of the characteristics (and especially the costs) of the printing product into two major groups: the commodity aspects and costs; and the informational (or custom) aspects and costs.
[0131] The commodity aspects and costs are those that are deliberately forced to be non-varying among all of the print jobs. These include papers, inks and depreciation. Only a relatively small set of different papers may be permitted which reduces the cost of the paper to a bare minimum. Only standard process inks may be permitted, which similarly reduces ink costs to a bare minimum. Finally, printing equipment costs (including depreciation expense) are also in the nature of a commodity across the many jobs that are to be printed. The goal is to reduce these costs to the bare minimum that would be achieved were the presses to be run at full capacity and with zero setup time. The costs are driven toward this result by using techniques that reduce the setup time to a bare minimum and give the printer equipment owners a medium for easily filling essentially all of their unused capacity.
[0132] On the informational (custom) side are such aspects as definition of content of each print job, price, delivery, and other terms, the ability to reduce capacity underutilization, color definition and verification, variations in quantity, the details of delivery and invoicing, the details of change over and setup, and marketing and sales efforts. On this informational side, too, the goal of the implementations is to drive the costs down (in theory to near zero) using information technology, electronic communication, and other techniques.
[0133] Other embodiments are within the scope of the claims. For example, while fixed and variable fields are discussed above in the context of customer-defined templates, in some implementations the web server host may provide templates having this feature as part of the website studio. | The invention provides methods for managing print jobs. One such method includes (a) accumulating discrete print jobs electronically from respective customers, (b) aggregating the discrete print jobs into aggregate print jobs, each of the aggregate print jobs being printable at one time on units of an integral print medium, and (c) electronically distributing the aggregate print jobs to respective printers for printing. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a shear load dowel mounting for transmitting dynamic loads, having a shear load dowel, a shear load dowel bearing bush and at least one bearing housing holding the bearing bush and one holding the shear load dowel.
2. Description of Related Art
Shear load dowels are connection and compression distribution elements for two concrete parts running in the same plane, which are separated from one another by a gap. From European Patent Reference 0 119 652 a shear load dowel mounting is known, which has a shear load dowel, a shear load dowel bearing bush and a bearing housing holding the bearing bush. Furthermore, on the bearing housing are arranged end plates which fix the shear load dowel bearing bush on a shuttering during the adjustment of the concrete slab. The bearing housing has a multitude of closed loops of reinforcement steel wires. The loops lie in planes parallel to the direction of running of the gap.
Other conventional shear load dowel mountings are known. One of the essential problems of the static shear load dowel mounting is that in the region of the shear load dowels or in the region of the shear load dowel bearing bushes, often the compression limits for concrete are essentially exceeded. This problem may be reduced by increasing the number of shear load dowels in the direction of the running of the expansion gap, but this leads to considerably more costs. A shear load dowel mounting which also resists dynamic loadings is not thus achieved.
A system which with regard to the shear load dowel mounting may also bear up to dynamic loadings is shown in European Patent Reference EP-A-0 032 105. The bearing housings are formed by bowls more or less closed on all sides. Within the bowl, although with this the allowable compression limit of the concrete is exceeded, the force transmission is effected onto the bowl and concrete running above the bowl is relieved so that the allowable compression limit is no longer exceeded.
A further development is shown in European Patent Reference EP-A-0 773 324. Also here is the problem of the static loading and in particular the load distribution for not exceeding the allowable compression limit of the concrete which is taken into account. As a solution, an end plate directed towards the gap is provided, wherein on each end plate there is arranged a plate protruding into the construction body. This plate lies in each case on the side of the dowel or the bush, which with the transmission of the static reaction forces onto the corresponding component lies opposite the compression-loaded side of the dowel or the bush. It is suggested to provide these plates projecting into the construction body so that in an idle manner, on the oppositely lying side, in order to be sure that the element also withstands the static loadings when it is inadvertently installed the wrong way.
SUMMARY OF THE INVENTION
This invention includes a method by which the shear load dowels may be manufactured, which comprise a core reduced free of play and a casing which projects beyond the core and whose ends by way of plastic plugs are protected against corrosion. According to this invention, shear load dowels preferably have relatively inexpensive constructional steel and only have a casing tube of stainless steel. Such shear load dowels have proven themselves extremely well for transmitting static loadings. They may also be precisely manufactured and are protected against corrosion.
It is one object of this invention to provide a shear load dowel mounting which in particular is suitable for dynamic loadings. With this invention, there are shear load dowel mountings on the market which allow for dynamic loadings.
With dynamic loading trials on shear load dowels, as known from European Patent Reference 0 765 967, one has ascertained that in contrast to shear load dowels which have a single mono-ferrite steel, have shown considerably improved dynamic-physical properties. Based on this knowledge further trials with multi-layered shear load dowels have been carried out which all showed improved results over shear load dowels of mono-ferrite material. With this, mono-ferrite shear load dowels are understood as those rods which have a single steel alloy and do not have several layers of equal steel alloys or differing steel alloys.
The invention provides a method for manufacturing shear load dowels since in particular with more than two layers the method is not so suitable.
It is one object of this invention to provide a shear load dowel mounting which is suitable for dynamic loadings.
This object is achieved by a shear load dowel mounting with the features described in the specification and the claims.
For the dynamic shear load dowel mounting the concept of a shear load dowel bearing housing with the features described in the claims as well as multilayered shear load dowel and their common arrangement is of essential importance. For dynamic loadings, these two elements are matched to one another.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings are shown a few embodiment examples of this invention and these are explained by way of the subsequent description wherein:
FIG. 1 a is a vertical longitudinal section taken perpendicular to a direction of the course of the gap;
FIG. 1 b is a rear view of an end plate of the same shear load dowel mounting in which the shear load dowel bearing bush is held;
FIG. 1 c shows a cross section of the shear load dowel taken along the line A—A, as shown in FIG. 1 a;
FIG. 2 a shows the same view as FIG. 1 a, but of a second embodiment;
FIG. 2 b shows the same view as FIG. 1 b of the embodiment according to FIG. 2 a;
FIG. 2 c shows a cross section taken through the shear load dowel shown in FIG. 2 a, along the line B—B;
FIG. 3 a shows another embodiment of a shear load dowel mounting as shown in FIG. 1 a;
FIG. 3 b shows a rear-side view as shown in FIG. 1 b but corresponding to the embodiment according to FIG. 3 a;
FIG. 3 c shows a section of the shear load dowel shown in FIG. 3 a, along the line C—C;
FIG. 4 a shows another embodiment of this invention as shown in FIG. 1 a;
FIG. 4 b shows a view as shown in FIG. 1 b but of the embodiment according to FIG. 4 a; and
FIG. 4 c shows a cross section taken through the shear load dowel shown in FIG. 4 a, along line D—D.
DESCRIPTION OF PREFERRED EMBODIMENTS
The two constructional parts which are under dynamic loading and which are connected to one another by way of the shear load dowel mounting are here indicted at B 1 and B 2 . FIG. 1 a shows the elements deposited in concrete. Essentially the shear load dowel mounting is designed symmetrically with respect to the gap F to be bridged. The shear load dowel mounting includes the shear load dowel 1 , a shear load dowel bearing bush 2 as well as bearing housings 3 .
The bearing housings 3 have at least two elements, specifically an end plate 4 and a strap-like loop 5 . The strap-like loop 5 with the end plate 4 together form a closed force system. The end plate 4 is admitted in the concrete flush with the end surface of the respective concrete part B 1 , B 2 , which is directed towards the joint. The strap-like loops are arranged so that they transmit the alternating loads occurring on the shear load dowel onto the end plate. This is achieved by the strap-like design of the loops 5 . The strap-like loops 5 may be designed in various shaping forms. They may have the same width as the end plates 4 or be narrower or wider than the end plates 4 . In the embodiment according to FIG. 4 the strap-like loop 5 has the same width as the end plate 4 , while the remaining embodiments show the strap-like loops narrower than the end plate 4 . The shear load dowel 1 and the shear load dowel bearing bush 2 may pass through the strap-like loop 5 , as shown by the embodiments according to the FIGS. 1 and 4, or they may be embraced by the loops 5 as shown by the embodiment according to FIG. 2 . In both variants the loops 5 have strap-like functions, as shown in the embodiment according to FIG. 3 . Each side has two straps which together form a closed force system with the end plate 4 . At the upper end of the one end plate there engages a strap-like loop 5′ which extends up to below the shear load dowel bearing bush 2 . This results in a bearing design similar to a suspension bridge, for loadings in the one direction, while second strap-like loops 5 ″ extend from the lower end of the end plate 4 up to the upper region of the shear load dowel bearing bush 2 . The strap-like loops run laterally past the shear load dowel bearing bush 2 . The same also applies to the oppositely lying side where the straplike loops 5 ′ and 5 ″ instead of being connected to the shear load dowel bearing bush 2 are connected directly to the shear load dowel.
The possible shapes of the strap-like loops 5 in a side view may for example be trapezoidal, wherein one preferably selects the shape of an equilateral trapezoidal with a height that may be different, as shown by the dashed line in the component B. The shape of the strap-like loops 5 however may be also roughly the shape of a triangle as shown in FIG. 2 a. This shape may also be achieved when the shear load dowel or the shear load dowel bearing bush in each case pass through the single strap-like loop 5 . The strap-like loop 5 may also be shaped semicircularly as FIG. 4 a shows. In order, during the casting, to prevent the possible formation of bubbles within the bearing housing 3 , the strap-like loops 5 preferably have bleeding bores or bleeding holes 6 of any size and any number as is shown by the various embodiment forms.
For the transmission of the dynamic loadings the multi-layered design of the shear load dowel 1 is required. Only with the multi-layered design of the shear load dowels can there be achieved the physical properties, specifically the demanded ability to be alternately loaded, paired with the high compressive strength, shear strength and elasticity values. Shear load dowels with a mono-ferrite cross section i.e. shear load dowels which in their entirety are of one metal or one metal alloy and of one piece have not mustered these desired pairings of the physical properties. Up to now multi-layered shear load dowels were used essentially for reasons of cost as well as for reasons of corrosion protection. With this laminar construction, the physical properties of the shear load dowel may be set such that shear load dowel mountings may be constructed, which are capable of transmitting the dynamic loadings.
As a rule the shear load dowels according to this invention may also be manufactured multi-layered with all common known cross-sectional shapes. The most common cross-sectional shapes such as cylindrical shear load dowels as well as shear load dowels with a rectangular or square cross section are possible. While a shear load dowel with a rectangular or square cross section principally may be formed of a layering of at least two plate-like rods, three or more layers are preferred. With this the outermost layer may also be formed as an embracing casing. Also the connection between the plate-shaped rods to a shear load dowel may be of the most differing nature. Apart from adhesive and welding connections also connections with a positive and/or friction fit are also considered. With this, assemblies of plates may arise similar to multi-layered leaf springs, wherein the individual bearings for example may be connected to one another with a positive fit by rivets or pins interspersing them, or comprise lateral recesses for a connection by way of a hooping.
With the cylindrical embodiment forms of the shear load dowels, likewise two or multi-layered designs are considered. With this the diameter ratios depending on the choice of material combination plays a suitable part. The design can depend on the forces and movements to be expected. Dynamic loadings on shear load dowel mountings indeed occur in very varied applications from shear load dowels which connect road concrete slabs and ground plates in multi-story carparks to complex concrete designs, such as tunnel pipes or concrete channels. In all these applications there may be alternating loads occurring faster or slower which may only be adequately accommodated with shear load dowel mountings designed for dynamic loadings. Until now, there have been over-dimensioned shear load dowel mountings, which per se are only designed for static loadings, and the differently directed forces occurring with alternating loadings were summed in order to reach an effective rigid region which thus in turn corresponds to the static loadings.
As shown in FIG. 2 c also one cylindrically formed shear load dowel may be manufactured of more than two layers. For this purpose the method known from European Patent Reference 0 765 967 is not so suitable. In a particularly interesting method for manufacturing such shear load dowels, over a central cylindrical rod is slided a first tube which surrounds this rod with a certain play and then its diameter by way of a hammering method is hammered onto the core completely free of play. An extremely exact rod may be achieved, wherein the friction connection is excellent. Without problem in the same manner a further tube may be pulled over the two-layered core formed in this manner, again with play, wherein again by way of a hammering method the new outermost casing may be hammered onto the already two-layered core. Thus there may be formed a rod of any number of layers which has enormous strengths and physical properties that may be tailored to suit any application.
In most cases one would usually operate with different steel alloys for the various layers. It has however been shown that also when maintaining the steel alloy alone, by way of the multi-layered or multi-ply design of the shear load dowel, considerably improved values may be achieved.
It is not compelling for the core of the shear load dowel to be a rod. Also variants are considered with which the core is an innermost tube and several tubes in several layers are pulled thereover and are hammered. Finally however also the hollow space of the innermost tube for physical reasons or as a corrosion protection may be filled out with a curing mass.
For achieving the dynamic loadability which here is required for the dowel, it is necessary to vary the hardness of the multi-layered dowel between the individual layers. It is possible to design the hardness increasing as well as decreasing from the outside to the inside. For various reasons it is particularly advantageous to select the hardness to increase from the outside to the inside.
For the manufacture of the multi-layered dowel with several layers, wherein the individual layers are arranged tube-like over one another, a particularly If suitable result may be achieved with the manufacture where one pushes on the respective outer layer as a tube with play and thereafter by a known hammering method attaches this to the core with a friction fit. Also here the core may be a rod or a single or multi-layered tube. The material compactings achieved with the hammering method result in a physically better product than a multi-layered dowel formed with a friction fit by way of thermal methods. | A shear-load chuck which is mounted between two members and has a multi-layer structure for transmitting dynamic loads. The multi-layer shear-load chuck is mounted on one surface of a junction like in the traditional bushing of a shear load chuck. A support basket is arranged correspondingly on both sides of the junction and has an end plate as well as at least one strap-like loop. The end plate forms together with the at least one strap-like loop a closed load system. The support basket is attached to the shear-load chuck on one surface of the junction, while it is attached to the bushing on the other surface of the junction. It is further possible to change the cross-sectional shape of the multi-layer shear-load chuck as well as the structural shape of the strap-like loop. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and hereby claims priority to International Application No. PCT/EP2007/058960, filed on Aug. 29, 2007, and German Application No. 10 2006 040 726.1, filed Aug. 31, 2006, the contents of both of which are hereby incorporated by reference.
BACKGROUND
[0002] 1. Field
[0003] The embodiments discussed herein relate to an apparatus, in particular a microsystem, with a device for energy conversion.
[0004] 2. Background of the Invention
[0005] There is an increasing demand for microsystems in the fields of sensor systems, actuator systems, in data communications, in in-situ diagnosis and also in the area of automotive and automation technologies. Such microsystems must be supplied with energy for their operation. In such cases the microsystems should be as independent as possible, i.e. autonomous, and also maintenance-free.
[0006] Conventional self-sufficient systems are known which are operated solely by means of solar energy conversion. The disadvantage of these systems is that all application areas are excluded in which no use can be made of solar energy. Difficulties also arise in the use of solar energy by means of solar cells with miniaturization and integration into CMOS technology.
SUMMARY
[0007] An aspect of the embodiments discussed herein is to provide energy conversion in a simple, effective and low-cost manner for an apparatus, in particular for a microsystem. The device should be able to be integrated into conventional semiconductor technologies and essentially be maintenance-free. Further requirements are wireless operation as well as an optimum miniaturization of the apparatus. The apparatus should be designed to be used especially as a sensor, an actuator and/or for data transmission and/or for in-situ diagnosis and/or as a source or generator of energy and/or as a signal generator.
[0008] It is an aspect to also make possible the in-situ diagnosis of, especially rotating, components in a simple and self-sufficient manner. An apparatus, especially a microsystem, includes a device for energy conversion, which has a piezoelectric membrane structure able to be vibrated mechanically for conversion of mechanical energy into electrical energy, with the membrane structure being coupled to a transformer and being able to be displaced by a movement of the transformer and with the movement of the transformer being able to be effected in a non-contact manner by interaction between the transformer and the moving part.
[0009] The solution to the conversion of the energy thus lies in first converting the nature of the mechanical energy, especially the movement of a component, which is adjacent to the apparatus, and then converting it into electrical energy. This means that the movement energy of the component is used to mechanically excite the membrane structure of the apparatus and to use this excitation for conversion into electrical energy. Energy is utilized by utilizing the deflection of a piezoelectric membrane structure, to which the movement of the moving component is transmitted.
[0010] The apparatus forms a generator which essentially represents a spring-mass system which is able to convert mechanical energy into electrical energy. The electrical energy is thus made available to a self-sufficient microsystem, e.g. for an in-situ diagnosis, or it can be stored. The generator obtains the mechanical energy to be converted by being coupled to the component adjacent to it and to be monitored which executes a movement during the monitoring.
[0011] The piezoelectric generator basically includes the membrane structure which contains a functional piezoelectric layer. An alternating deflection of the membrane structure leads to mechanical stress in the piezoelectric layer, so that a continuous charge displacement occurs within this layer. This charge displacement can be used for energy utilization.
[0012] In accordance with an advantageous embodiment the movement of the transformer can be effected by magnetic interaction of the transformer with the part which moves and in some places has magnetic characteristics. The transformer and thus the membrane structure are deflected by forces of attraction or repulsion, with it being possible to transmit the movement in a non-contact manner to the transformer. The advantage of this is that no or only slight constructional changes are necessary for monitoring the moving component.
[0013] In accordance with an advantageous embodiment the movement of the transformer is imparted by a rotating part, so that a periodic movement or oscillation of the transformer and the membrane structure is effected. The inventive device is thus suitable in particular for non-contact and thereby self-sufficient monitoring of rotation machines, such as shafts or turbines for example.
[0014] In accordance with an advantageous embodiment the transformer has permanent magnetic properties. These can be provided by a permanent magnet layer or a permanent magnet.
[0015] In accordance with an advantageous embodiment, for embodying the membrane structure, a piezoelectric layer arranged between two electrode layers is arranged on a wafer such that at least the electrode layer lying against the wafer extends out over a wafer cutout.
[0016] In accordance with a further advantageous embodiment, for embodying the membrane structure, the piezoelectric layer arranged between two electrode layers is arranged on a carrier layer on the wafer such that at least the carrier layer lying against the wafer extends out over the wafer cutout.
[0017] In accordance with a further advantageous embodiment, the electrode layers and the piezoelectric layer are arranged in the area of the wafer cutout. In this way the piezoelectric layer can effectively detect the vibration fluctuations.
[0018] In accordance with a further advantageous embodiment, a mass on an additional mass is mechanically coupled to the membrane structure and the transformer is provided on the additional mass. In this way the membrane structure can be made especially sensitive for mechanical energy in the form of vibrations.
[0019] The additional mass can advantageously be lying against the membrane structure and/or integrated into the carrier layer in the area of the wafer cutout and/or be integrated into one of the electrode layers in the area of the wafer cutout. In the first case, for example, lead can be applied to an electrode layer, for example by soldering it on. In the second case the carrier layer can have a boss structure. A “boss structure” is a membrane stiffened in the center.
[0020] In order to achieve a maximum deflection of the membrane structure and thereby a maximized energy yield, it is advantageous for the connection of the additional mass to the membrane structure to be made such that the stiffness is only adversely affected in a small surface section and as large a surface as possible is available for the charge transport.
[0021] In accordance with a further advantageous embodiment, the at least one membrane structure is provided as a spring-mass system with a resonant frequency such that this is situated within a frequency band of a movement of the part interacting with the transformer. The operation of the membrane structure with a resonant frequency makes possible a maximum energy yield.
[0022] In accordance with a further advantageous embodiment, the resonant frequency of the membrane structure is able to be adjusted in particular by variation of the mass and/or spring stiffness. To this end the membrane structure can have discrete mass areas which are fixed so that only the unfixed mass vibrates. Likewise a membrane structure can have areas with different spring stiffnesses, which can be explicitly selected and activated for provision of different resonant frequencies.
[0023] In accordance with a further advantageous embodiment, at least one of the electrode layers has a digital shape. Digital here merely means “subdivided”, i.e. “not contiguous”. The digital electrode surfaces are preferably designed so that they satisfy the respective equipotential surfaces as regards the mechanical stress in the layer, in order to reduce negative effects of electromechanical feedback of the piezoelectric membrane during energy conversion.
[0024] In accordance with a further advantageous embodiment, the device for energy conversion is embodied as a sensor, an actuator, for data communications and also in the area of automotive and automation technology and/or as a source of energy and/or as a signal generator and/or as a means of diagnosis.
[0025] The invention also provides a system with a moving component and an apparatus, in particular a microsystem, for energy conversion, with a mechanical movement of the transformer of the device being created in a non-contact manner by interaction with the component by the movement of the component, with the mechanical movement of the transformer able to be converted by the apparatus into electrical energy.
[0026] The apparatus used for this purpose is embodied as described above. The system has the same advantages as have already been described in connection with the inventive device.
[0027] In accordance with a further embodiment, the moving component is a rotation machine, such as a shaft, a gas turbine or a turbine blade for example. The energy necessary to excite the membrane structure can however also be obtained with a component which performs a linear movement.
[0028] In accordance with a further embodiment, a second transmission device deflecting the transformer in a non-contact manner is provided on the moving component at regular intervals.
[0029] In accordance with a further embodiment, the second transmission means is embodied by a ferromagnetic material, especially iron, cobalt or nickel, or a permanent magnet.
[0030] In accordance with a further embodiment, the second transmission means is embodied by the rotation machine itself, e.g. the blades of a turbine, provided this is made of a ferromagnetic material or is arranged thereon, e.g. the turbine blades.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] These and other aspects and advantages will become more apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which:
[0032] FIG. 1 shows a first exemplary embodiment of a piezoelectric membrane structure and a moving component coupled to this in a non-contact manner; and
[0033] FIG. 2 shows a second exemplary embodiment of a piezoelectric membrane structure and a moving component coupled to this in a non-contact manner.
[0034] In the figures the same elements are provided with the same reference symbols.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0035] Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0036] In accordance with the exemplary embodiments a device 100 for energy conversion is used as a source of energy in the form of a piezoelectric micropower generator.
[0037] FIG. 1 shows an apparatus with a device 100 for energy conversion. The device 100 includes a wafer 1 with a wafer cutout 4 made in it. The wafer 1 can, for example, be Silicon and/or SOI (Silicon on Insulator). In the area of the wafer cutout 4 a membrane structure 3 is arranged on a carrier layer 2 on the wafer 1 . The carrier layer 2 is connected to the wafer 1 so that it can vibrate.
[0038] The membrane structure 3 includes two electrode layers 5 a , 5 b , between which a piezoelectric layer 6 is arranged. The electrode layers 5 a , 5 b can be made of platinum, titanium and/or platinum/titanium or also of gold. The piezoelectric layer 6 including, for example, PZT, A1N and/or PTFE or can also be made of the material ZnO. The piezoelectric layer 6 can additionally be created as a series of layers or individually as a thin layer PVD (smaller than 5 μm) as a sol-gel layer (smaller than 20 μm), and/or as a glued-on bulk piezolayer.
[0039] The carrier layer 2 is for made from silicon, polysilicon, silicon dioxide and/or Si3N4. In this embodiment it is expedient for the carrier layer 2 to be connected with the wafer 1 to allow oscillation and in this case to extend out over the wafer cutout 4 . The connection between carrier layer 2 and wafer 1 can, for example, be created by gluing or soldering.
[0040] In a further exemplary embodiment not shown, the carrier layer is created by the lower electrode layer 5 a , i.e. the layer abutting the wafer 1 . The lower electrode layer 5 a thus simultaneously performs the function of the carrier layer 2 .
[0041] Digital electrode surfaces 9 , i.e. subdivided, non-contiguous electrodes of the electrode layer 5 b , make it possible to reduce negative effects of electromechanical feedback of the piezoelectric membrane during energy conversion.
[0042] A mass 7 is arranged on the membrane structure 3 which extends from the electrode layer 5 a out into the wafer cutout 4 . The additional mass 7 is coupled to the membrane structure 3 , so that movements can be detected more effectively by the membrane structure 3 and the piezoelectric layer 6 .
[0043] In accordance with the exemplary embodiment of FIG. 1 a mass made of wafer material is coupled to the membrane structure 3 . The additional mass 7 can be created by applying the electrode layer 5 a to an upper side of the wafer 1 and by one or more subsequent etching processes through from the rear side of the wafer 1 .
[0044] Alternately an additional mass 7 in the form of a sphere or another form can be coupled to the membrane structure 3 . The sphere can for example be made of lead or of another material and soldered onto the electrode layer 5 a . With this variant it is advantageous for the surface on which the additional mass 7 stands on the membrane structure 3 to be very small, so that only a slight stiffening of the membrane structure is produced.
[0045] Arranged on the side of the additional mass facing away from the membrane structure 3 is a transformer 8 . The transformer is embodied by a permanent-magnetic layer or a permanent magnet. The transformer can for example be embodied from Nd Fe—B or Fe—Co—V. The transformer 8 interacts magnetically with a further transformer which is arranged on a rotation machine 10 . The rotation machine 10 is embodied in the exemplary embodiment as a turbine rotor which has a plurality of blades 11 which are mounted on a shaft 12 . The further transformer can for example be embodied by the material of the blades themselves, which are usually made of a ferromagnetic material. Frequently Fe, Co or Ni are used for this purpose. If the blades 11 are not made of a ferromagnetic material permanent magnets which assume the function of the further transformer could be arranged on their ends facing away from the shaft 12 .
[0046] The device 100 for conversion of energy is for example arranged in a housing in a rotation plane of the turbine rotor which surrounds the rotating turbine rotor. In this case the transformer 8 faces towards the turbine rotor. The rotation of the turbine rotor leads to a non-contact magnetic interaction with the transformer 8 , with the movement forced in the latter causing a movement of the membrane structure 3 . The rotation of the turbine rotor therefore causes the membrane structure 3 to be periodically displaced, so that the resulting oscillation of the membrane structure 8 can be used for obtaining energy.
[0047] The further transformer could also be arranged on or in the area of the shaft 12 of the rotation machine 10 . The further transformers made of a ferromagnetic material or in the form of permanent magnets are then arranged at intervals over the circumference of the shaft 12 . This likewise leads to a mechanical stressing or oscillation of the membrane structure.
[0048] FIG. 2 shows a further exemplary embodiment of the inventive device 100 , in which a number of digital masses 7 , i.e. subdivided masses extend from the carrier layer 2 into the wafer cutout 4 . In a corresponding manner the function layer 5 b facing away from the carrier layer 2 features a number of electrode surfaces 9 which are arranged in the area of the free spaces lying between adjacent part masses. The distribution of the masses brings the advantage of a larger surface being available for generation of energy in the membrane structure 3 . At the same time the stiffness can be influenced in the desired form.
[0049] By selecting the additional mass 7 , the resonant frequency of the membrane structure can be adjusted in a simple, effective manner. On the other hand the resonant frequency can likewise be adjusted by defining the stiffness of the membrane structure. A further option for adjusting the resonant frequency is the selection of the corresponding materials of the membrane structure 3 for defining the spring stiffness of the membrane structure 3 . Likewise the size of the wafer cutout 4 can be selected and the desired resonant frequency adapted. There are no restrictions imposed on the choice of material as regards the additional mass 7 . specially dense materials make possible especially compact embodiments of a piezoelectric micropower generator for vibrations.
[0050] In accordance with the described exemplary embodiment the device for energy conversion is used as a piezoelectric micropower generator which makes it possible to supply energy from self-sufficient apparatuses or microsystems while utilizing magnetic interactions with a moving component, which are present in the surroundings of the microsystem. The piezoelectric effect in this case is not only exploited in a spatial dimension, such as for example in the arrangement of a bar, but in the entire surface of the membrane structure, so that an effective energy yield can be achieved.
[0051] The piezoelectric generator offers the advantage of a self-sufficient energy supply of a microsystem for use in rotation machines. The energy converter makes it possible to set up a diagnostic tool, which essentially does not demand any constructional change to the actual rotation machine. The microsystem makes it possible to handle the specific tasks directly at the desired location at a desired time.
[0052] The piezoelectric energy converter can be implemented in CMOS technology at wafer level and can be integrated directly into a microsystem “on-chip”.
[0053] The piezoelectric generator essentially represents a spring-mass system which is able to convert the mechanical energy of the moved parts of the rotation machine into electrical energy in a non-contact manner. The electrical energy is available to the self-sufficient microsystem or can be stored. The mechanical energy to be converted is converted in a non-contact process by means of magnetic interaction into a periodic deflection of the spring-mass system of the actual energy converter. The precondition for the creation of the movement of the membrane structure of the energy converter is the presence of a permanent magnetic layer or of a permanent magnet on the membrane structure or preferably of the additional mass connected to the membrane structure. To guarantee the magnetic interaction between the rotation machine and the actual energy converter, a ferromagnetic material or a permanent magnet is also provided on the rotation machine.
[0054] A description has been provided with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 358 F3 d 870, 69 USPQ2 d 1865 (Fed. Cir. 2004). | The embodiments describe an apparatus, in particular a microsystem, including a device for energy conversion, which device has apiezoelectric, mechanically vibrating diaphragm structure for converting mechanical energy into electrical energy. The diaphragm structure being coupled to a transformer and it being possible to displace said diaphragm structure by moving the transformer, and it being possible to effect the movement of the transformer in a contact-free fashion by interaction of the transformer with a moving part. | 7 |
RELATED APPLICATIONS
This application is a 35 USC § 371 application of PCT/JP95/01144, filed Jun. 7, 1995, and a continuation-in-part application of U.S. application Ser. No. 971,997 (Atty. Docket No. 53466/114), filed Feb. 21, 1997, which is a continuation of U.S. application Ser. No. 08/268,520, filed Jun. 30, 1994, abandoned.
TECHNICAL FIELD
The present invention relates to a chronic rheumatoid arthritis therapy or synovial cell growth inhibitor comprising an interleukin-6 antagonist as an effective component.
BACKGROUND ART
Chronic rheumatoid arthritis is a systemic chronic inflammatory disease in which abnormal growth of connective tissue, including synovial tissue, occurs in the joints (Melnyk et al., Arthritis Rheum. 33: 493-500, 1990). The joints of chronic rheumatoid arthritis patients have been shown to have marked growth of synovial cells, formation of a multilayer structure due to abnormal growth of the synovial cells (pannus formation), invasion of the synovial cells into cartilage tissue and bone tissue, vascularization toward the synovial tissue, and infiltration of inflammatory cells such as lymphocytes and macrophages. Mechanisms of onset of chronic rheumatoid arthritis have been reported to be based on such factors as heredity, bacterial infection and the contribution of various cytokines and growth factors, but the overall mechanism of onset has remained unclear.
In recent years, cytokines and growth factors including interleukin-1 (IL-1), interleukin-8 (IL-8), tumor necrosis factor α (TNFα), transforming growth factor β (TGFβ), fibroblast growth factor (FGF) and platelet-derived growth factor (PDGF) have been detected in the synovial membrane and synovial fluid of chronic rheumatoid arthritis patients (Nouri et al., Clin. Exp. Immunol. 55:295-302, 1984; Thornton et al., Clin. Exp. Immunol. 86:79-86, 1991; Saxne, et al., Arthritis Rheum. 31:1041-1045, 1988; Seitz et al., J. Clin. Invest. 87:463-469, 1991; Lafyatis et al., J. Immunol. 143:1142-1148, 1989; Melnyk et al., Arthritis Rheum. 33:493-500, 1990).
It is believed that IL-1, TNFA and PDGF are particularly powerful synovial cell growth factors (Thornton et al., Clin. Exp. Immunol. 86:79-86, 1991; Lafyatis et al., J. Immunol. 143:1142-1148, 1989; Gitter et al., Immunology 66:196-200, 1989). It has also been suggested that stimulation by IL-1 and TNF results in production of interleukin-6 (IL-6) by synovial cells (Ito et al., Arthritis Rheum. 35:1197-1201, 1992).
IL-6 is a cytokine also known as B cell-stimulating factor 2 or interferon β2. IL-6 was discovered as a differentiation factor contributing to activation of B lymphoid cells (Hirano, T. et al., Nature 324, 73-76, 1986), and was later found to be a multifunction cytokine which influences the functioning of a variety of different cell types (Akira, S. et al., Adv. in Immunology 54, 1-78, 1993). Two functionally different membrane molecules are necessary for the induction of IL-6 activities. One of those is IL-6 receptor (IL-6R), an approximately 80 KD molecular weight, which binds specifically to IL-6.
IL-6R exists in a membrane-binding form which is expressed on the cell membrane and penetrates the cell membrane, as well as in the form of soluble IL-6R (sIL-6R) which consists mainly of the extracellular domain. Another protein is gp130 with a molecular weight of approximately 130 KD, which is non-ligand-binding but rather functions to mediate signal transduction. IL-6 and IL-6R form the complex IL-6/IL-6R which in turn binds with another membrane protein gp130, to induce the biological activity of IL-6 to the cell (Taga et al., J. Exp. Med. 196:967, 1987).
It has been reported that the serum or synovial fluid of chronic rheumatoid arthritis patients contains excessive amounts of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) (Houssiau et al., Arthritis Rheum. 31:784-788, 1988; Hirano et al., Eur. J. Immunol. 18:1797-1801, 1988; Yoshioka et al., Japn. J. Rheumatol. in press), and since similar results have also been obtained in rheumatoid arthritis animal models (Takai et al., Arthritis Rheum. 32:594-600, 1989; Leisten et al. Clin. Immunol. Immunopathol. 56: 108-115, 1990), it has been suggested that IL-6 is somehow involved in chronic rheumatoid arthritis.
However, Japanese Unexamined Patent Publication No. 4-89433 discloses that peptides which strongly promote IL-6 production are effective as therapies for chronic rheumatoid arthritis.
Also, Higaki et al. have suggested that synovial cells from chronic rheumatoid arthritis patients have a low growth reaction against IL-6, and that IL-6 thus has an inhibitory function against growth of synovial cells (Clinical Immunology, 22:880-887, 1990). Thus, conflicting reports exist regarding the relationship between IL-6 and chronic rheumatoid arthritis, and the relationship is as yet unclear.
Recently, Wendling et al. have reported that administration of anti-IL-6 antibodies to chronic rheumatoid arthritis patients temporarily alleviates the clinical and biological symptoms, while also increasing IL-6 levels in the serum (J. Rheumatol. 20:259-262, 1993).
These reports provide no data at all about whether IL-6 accelerates growth of chronic rheumatoid arthritis synovial cells or has an inhibitory effect, and thus it is still unknown whether or not IL-6 has a direct effect on synovial cells of chronic rheumatoid arthritis patients.
DISCLOSURE OF THE INVENTION
Anti-inflammatory steroidal agents such as corticosteroids have been used as rheumatoid arthritis therapies, but since their continuous use induces undesirable side effects such as skin tissue damage and inhibition of adrenal cortex function, drugs with less side effects have been sought.
It is an object of the present invention to provide a novel chronic rheumatoid arthritis therapy without the disadvantages mentioned above. More specifically, the present invention provides a pharmaceutical composition for inhibiting abnormal growth of synovial cells in chronic rheumatoid arthritis, whose effective component is an interleukin-6 antagonist, as well as a pharmaceutical composition for treatment of a chronic rheumatoid arthritis having the same effect.
The present inventors have conducted diligent research on the role of IL-6 on synovial cells from rheumatoid arthritis, during which no growth of chronic rheumatoid arthritis synovial cells was found with IL-6 alone and a factor other than IL-6 was therefore investigated, and this has resulted in completion of the present invention based on the discovery that while IL-6 alone exhibits almost no growth effect on synovial cells, a powerful synovial cell growth effect occurs in the presence of both IL-6 and soluble IL-6R, and further that this synovial cell growth effect is suppressed by addition of an antagonist which inhibits IL-6 activity, such as IL-6 antibody or IL-6R antibody.
In other words, the present invention relates to a pharmaceutical composition for treatment of a chronic rheumatoid arthritis comprising an IL-6 antagonist as the effective component. More specifically, the present invention relates to-a pharmaceutical composition for treatment of a chronic rheumatoid arthritis comprising an IL-6 antagonist as the effective component and suppressing abnormal growth of synovial cells. The present invention also relates to a synovial cell growth inhibitor whose effective component is an IL-6 antagonist.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing 3 H-thymidine uptake into synovial cells in the presence of either IL-6 or sIL-6R alone and in the presence of both IL-6 and sIL-6R.
FIG. 2 is a graph showing the effect of IL-6 antibody or IL-6R antibody on 3H-thymidine uptake into synovial cells in the presence of both IL-1β and sIL-6R.
FIG. 3 is a graph showing the effect of IL-6 antibody or IL-6R antibody on 3 H-thymidine uptake into synovial cells in the presence of both IL-6 and sIL-6R.
FIG. 4 is a graph showing the suppressive effect of IL-6R antibody on the onset of mouse collagen-induced arthritis models.
FIG. 5 is a graph showing serum anti-collagen antibody levels in arthritic mice.
FIG. 6 is a photograph of histopathological examination of hind paw joint of a collagen-arthritis mouse. (a) is a photograph from a mouse in an IL-6 receptor antibody-administered group, and (b) is from a mouse in a control antibody-administered group. In the IL-6 receptor antibody-administered group, invasion of granulation tissue into the cartilage and bone (chronic proliferative synovitis) was clearly suppressed.
DETAILED DESCRIPTION OF THE INVENTION
A pharmaceutical composition for treatment of a chronic rheumatoid arthritis according to the invention is a drug which when administered to chronic rheumatoid arthritis patients suppresses growth of synovial cells in joints and has an alleviating and therapeutic effect on the symptoms.
The IL-6 antagonist use-d according to the invention may be derived from any source so long as it is a substance which blocks IL-6 signal transfer and inhibits IL-6 biological activity. IL-6 antagonists include IL-6 antibody, IL-6R antibody, gp130 antibody, modified IL-6, antisense IL-6R and partial peptides of IL-6 or IL-6R.
An antibody used as an antagonist according to the invention, such as IL-6 antibody, IL-6R antibody or gp130 antibody, may be of any derivation or type (monoclonal, polyclonal), but monoclonal antibodies derived from mammalian animals are especially preferred. These antibodies bind to IL-6, IL-6R or gp130 to inhibit binding between IL-6 and IL-6R or IL-6R and gp130 and thus block IL-6 signal transduction, inhibiting IL-6 biological activity.
The animal species for the monoclonal antibody-producing cells is not particularly limited so long as it is a mammal, and human antibodies or antibodies derived from a mammal other than human may be used. Monoclonal antibodies derived from a mammal other than human are preferably monoclonal antibodies derived from rabbits or rodents because they are easier to prepare. There is no particular restriction on the rodents, but preferred examples are mice, rats and hamsters.
Examples of such antibodies which are IL-6 antibodies include MH166 (Matsuda et al., Eur. J. Immunol. 18:951-956, 1988) and SK2 antibody (Sato et al., Journal for the 21st General Meeting of the Japan Immunology Association, 21:116, 1991). Examples of IL-6R antibodies include PM-1 antibody (Hirata et al., J. Immunol. 143:2900-2906, 1989), AUK12-20 antibody, AUK64-7 antibody and AUK146-15 antibody (Intl. Unexamined Patent Application No. W092-19759). An example of gp130 antibody is AM64 antibody (Japanese Unexamined Patent Publication No. 3-219894).
Among these, PM-1 antibody is preferred.
Monoclonal antibodies may be prepared in the following manner which is based on a known technique. That is, IL-6, IL-6R or gp130 is used as the sensitizing antigen for immunization according to a conventional immunizing method, and the resulting immunocytes are then fused with known parent cells by a conventional cell fusion method and monoclonal antibody-producing cells are screened by a conventional screening method to prepare the antibodies.
More specifically, the monoclonal antibodies may be prepared in the following manner. For example, if the sensitizing antigen is human IL-6, the antibodies are obtained using the gene sequence for human IL-6 disclosed by Hirano et al., Nature, 324:73, 1986. The human IL-6 gene sequence is inserted into a publicly expression vector system and used to transform suitable host cells, after which the desired IL-6 protein is purified from the host cells or from the culture supernatant and the purified IL-6 protein is then used as the sensitizing antigen.
In the case of human IL-6R, the IL-6R protein may be obtained by the same method as for human IL-6 described above, using the gene sequence disclosed in European Patent Application No. EP325474. Two types of IL-6R exist, one expressed on the cell membrane and a soluble form (sIL-6R) which is separated from the cell membrane. sIL-6R consists mainly of the extracellular domain of IL-6R which is attached to the cell membrane, and it differs from the membrane-bound IL-6R in that it lacks the transmembrane domain or the transmembrane domain and the intracellular domain.
In the case of human gp130, the gp130 protein may be obtained by the same method as for human IL-6 described above, using the gene sequence disclosed in European Patent Application No. EP411946.
The mammalian animals immunized with the sensitizing antigen are not particularly restricted, but they are preferably selected -in consideration of their compatibility with the parent cells used for the cell fusion, and generally mice, rats, hamsters and rabbits may be used.
The immunization of the animals with the sensitizing antigen may be accomplished by a publicly known method. For example, a conventional method involves intraperitoneal or subcutaneous injection of the mammalian animals with the sensitizing antigen. Specifically, the sensitizing antigen is preferably diluted with an equivalent of PBS (Phosphate-Buffered Saline) or physiological saline, suspended and used together with a suitable amount of a conventional adjuvant such as Freund's complete adjuvant if desired, and then administered to the mammalian animals a few times every 4-21 days. An appropriate carrier may also be used for immunization with the sensitizing antigen.
After this immunization and confirmation of increased serum levels of the desired antibody, immunocytes are taken from the mammalian animals and supplied for cell fusion, with especially preferred immunocytes being splenic cells.
The parent cells used for fusion with the above-mentioned immunocytes may be myeloma cells from mammalian animals, and a number of already publicly known cell strains may be suitably used, including P3 (P3x63Ag8.653) (J. Immunol. 123:1548, 1978), p3-U1 (Current Topics in Microbiology and Immunology 81:1-7, 1978), NS-1 (Eur. J. Immunol. 6:511-519, 1976), MPC-11 (Cell, 8:405-415, 1976), SP2/0 (Nature, 276:269-270, 1978), Of (J. Immunol. Meth. 35:1-21, 1980), S194 (J. Exp. Med. 148:313-323, 1978), R210 (Nature, 277:131-133, 1979). The cell fusion of the immunocytes with the myeloma cells may be based on a publicly known method, for example the method of Milstein et al. (Milstein et al., Methods Enzymol. 73:3-46, 1981).
More specifically, the above-mentioned cell fusion is carried out in a conventional nutrient culture in the presence of a cell fusion promoter. The fusion promoter used may be, for example, polyethylene glycol (PEG) or Sendai virus (HVJ), and if desired an aid such as dimethylsulfoxide may also be added to increase the fusion efficiency.
The proportions of the immunocytes and myeloma cells used are preferably a 1- to 10-fold amount of immunocytes with respect to the myeloma cells. The culturing medium used for the cell fusion may be, for example, RPMI1640 culture medium or MEM culture medium which are suitable for growth of myeloma cell strains, or other common culturing media used for such cell culturing, and supplementary serum solutions such as fetal calf serum (FCS) may also be used therewith.
The cell fusion is carried out by thoroughly mixing the prescribed amounts of the immunocytes and the myeloma cells in the culture medium described above, adding a PEG solution preheated to about 37° C., for example with PEG having an average molecular weight of about 1000 to 6000, to the culture medium usually at a concentration of 30 to 60% (w/v), and then mixing to form the desired fused cells (hybridomas). Next, the procedure of gradual addition of a suitable culture medium and centrifugation to remove the supernatant is repeated, to accomplish removal of the cell fusing agent, etc. which is unfavorable for growth of the hybridomas.
Suitable hybridomas are selected by culturing in a normal selective culture medium, such as HAT culture medium (containing hypoxanthine, aminopterin and thymine). The culturing in the HAT culture medium is continued for a given time, usually a few days to a few weeks, sufficient for death of the cells other than the hybridomas (non-fused cells). Next, normal limited dilution is carried out, and the hybridomas producing the desired antibodies are subjected to masking and monocloning.
The monoclonal antibody-producing hybridomas prepared in this manner may be subcultured in a common culture solution and they may also be placed in liquid nitrogen for long-term storage.
In order to acquire the monoclonal antibodies from the hybridomas, the hybridomas are cultured according to a conventional method after which the culture supernatant is recovered, or else a method is used whereby the hybridomas are injected to a compatible mammalian animal, grown, and the ascites fluid is obtained. The former method is suited for obtaining high purity antibodies, while the latter method is suited for mass production of the antibodies.
The monoclonal antibodies obtained by these methods may then be purified to a high degree using conventional purification means, such as salting-out, gel filtration, affinity chromatography or the like.
The monoclonal antibodies prepared in this manner may then be checked for high sensitivity and high purity recognition of the antigen by common immunological means such as radioimmunoassay (RIA), enzyme-linked immunoassay, (EIA, ELISA), the fluorescent antibody technique (immunofluorescence analysis), etc.
The monoclonal antibodies used according to the invention are not limited to monoclonal antibodies produced by hybridomas, and they may be ones which have been artificially modified for the purpose of lowering the heteroantigenicity against humans. For example, a chimeric antibody may be used which consists of the variable region of a monoclonal antibody of a mammalian animal other than human, such as a mouse, and the constant region of a human antibody, and such a chimeric antibody may be produced by a known chimeric antibody-producing method, particularly a gene recombination technique.
Reshaped human antibodies may also be used according to the invention. These are prepared by using the complementary determinant region of a mouse or other non-human mammalian animal antibody to replace the complementary determinant region of a human antibody, and conventional gene recombination methods therefor are well-known. One of the known methods may be used to obtain a reshaped human antibody which is useful according to the invention. A preferred example of such a reshaped human antibody is hPM-1 (see Intl. Unexamined Patent Application No. W092-19759).
When necessary, amino acids of the framework (FR) region of the variable region of an antibody may be substituted so that the complementary determinant region of the reshaped human antibody forms a suitable antibody binding site (Sato et al., Cancer Res. 53:851-856, 1993). In addition, the object stated above may also be achieved by constructing a gene coding for an antibody fragment which binds to the antigen to inhibit IL-6 activity, such as Fab or Fv, or a single chain Fv (scFv) wherein the Fv of the H and L chains are attached via an appropriate linker, and using it for expression in appropriate host cells (see, for example, Bird et al., TIBTECH, 9:132-137, 1991; Huston et al., Proc. Natl. Acad. Sci. USA, 85:5879-5883, 1988).
Modified IL-6 used according to the invention may be the one disclosed by Brakenhoff et al, J. Biol. Chem. 269:86-93, 1994 or Savino et al., EMBO J. 13:1357-1367, 1994.
The modified IL-6 used may be obtained by introducing a mutation such as a substitution, deletion or insertion into the IL-6 amino acid sequence to maintain the binding activity with IL-6R while eliminating the IL-6 signal transfer function. The IL-6 source may be from any animal species so long as it has the aforementioned properties, but in terms of antigenicity, a human derived one is preferably used.
Specifically, the secondary structure of the IL-6 amino acid sequence may be predicted using a publicly known molecular modeling program such as WHATIF (Vriend et al., J. Mol. Graphics, 8:52-56, 1990), whereby the influence of mutated amino acid residues on the entire structure may also be evaluated. After determining appropriate mutated amino acid residues, a vector containing the nucleotide sequence coding for the human IL-6 gene is used as a template for introduction of the mutation by the conventionally employed PCR (polymerase chain reaction) method, to obtain a gene coding for the modified IL-6. This is then incorporated into a suitable expression vector if necessary and expressed in E. coli cells or mammalian cells, and then used either while in the culture supernatant or after isolation and purification by conventional methods, to evaluate the binding activity for IL-6R and the neutralized IL-6 signal transfer activity.
An IL-6 partial peptide or IL-6R partial peptide used according to the present invention may have any sequence so long as it binds to IL-6R or IL-6, respectively, and has no IL-6 activity transfer function. IL-6 partial peptides and IL-6R partial peptides are described in U.S. Pat. No. 5,210,075. An IL-6 antisense oligonucleotide is described in Japanese Patent Application No. 5-300338.
A pharmaceutical composition for treatment of chronic rheumatoid arthritis whose effective component is an IL-6 antagonist according to the invention is effective for treatment of chronic rheumatoid arthritis if it blocks IL-6 signal transduction and suppresses abnormal growth of synovial cells induced by IL-6, which are implicated in the disease. Example 1 demonstrates the in vitro growth suppressing effect on rheumatic patient-derived synovial cells. In Example 2, IL-6 receptor antibody was administered to mice arthritic models immunized with type II collagen, and the relevant data demonstrates (1) suppression of onset of arthritis on the basis of an arthritis index (FIG. 4), (2) suppression of anti-type II collagen antibody production in the blood of collagen-immunized mice (FIG. 5) and (3) suppression of granulation tissue invasion into cartilage and bone (chronic proliferative synovitis) in the hind paw joints of mice arthritic models administered IL-6 receptor antibody (FIG. 6).
In regard to (1) and (2) above, the results confirmed a suppressing effect by IL-6 receptor antibody, especially initially, on onset of arthritis in the mice models. The results of (3) demonstrated that invasion of granulation tissue into the cartilage and bone tissue is suppressed, and this supports the results obtained in Example 1 (in vitro inhibition of synovial cell growth).
The experimental results of (1) and (2) indicate that the pharmaceutical composition for treatment of chronic rheumatoid arthritis of the present invention has an excellent initial effect on rheumatoid arthritis.
The pharmaceutical composition for treatment of chronic rheumatoid arthritis of the invention is preferably administered parenterally, for example by intravenous, intramuscular, intraperitoneal or subcutaneous injection, either systemically or locally. Also, it may be in the form of a medical formulation kit together with at least one type of medical carrier or diluent.
The dosage of the pharmaceutical composition for treatment of chronic rheumatoid arthritis of the invention when administered to humans will differ depending on pathological condition and age of the patient, and the mode of administration, and thus suitable and appropriate doses must be selected. As an example, a maximum of 4 divided doses in the range of about 1 to 1000 mg/patient may be selected. However, the pharmaceutical composition for treatment of rheumatoid arthritis of the invention is not limited to these dosages.
The pharmaceutical composition for treatment of rheumatoid arthritis of the invention may be formulated according to conventional methods. For example, an injection formulation is prepared by dissolving the purified IL-6 antagonist in a solvent such as physiological saline or a buffer solution and then adding an adsorption inhibitor such as Tween 80, gelatin, human serum albumin (HSA) or the like, and the mixture may be lyophilized prior to use for solution reconstitution. The excipient used for lyophilization may be a sugar alcohol such as mannitol or glucose, or a saccharide.
EXAMPLES
The present invention will now be explained in more detail by way of the following examples, reference examples and experimental examples, with the understanding that the invention is in no way restricted thereto.
Reference Example 1
Preparation of human soluble IL-6 receptor
Soluble IL-6R was prepared (Yasukawa et al., J. Biochem. 108:673-676, 1990) by the PCR (polymerase chain reaction) method using plasmid pBSF2R.236 containing cDNA coding for human IL-6 receptor (IL-6R) obtained according to the method of Yamasaki et al. (Science, 241:825-828, 1988).
The aforementioned plasmid pBSF2R.236 was digested with restriction enzyme SphI to obtain an IL-6R cDNA fragment which was then inserted into mp18 (Amersham Co.). The synthetic oligoprimer ATATTCTCTAGAGAGATTCT designed for introduction of a stop codon in IL-6R cDNA was used to introduce a mutation in the IL-6R cDNA by the PCR method using an Invitro Mutagenesis System (Amersham Co.). This procedure resulted in introduction of a stop codon at the position of amino acid 345 to obtain cDNA coding for soluble IL-6R (sIL-6R).
In order to express the sIL-6R cDNA in CHO cells, the aforementioned sIL-6R cDNA cut with HindIII-SalI was inserted into plasmid pECEdhfr (Clauser et al., Cell, 45:721-735, 1986) which had cDNA coding for dihydrofolate reductase (dhfr) inserted at the restriction enzyme PvuI cleavage site, to obtain the CHO cell expression plasmid pECEdhfr344.
A 10 μg of plasmid pECEdhfr344 was used for transfection of the dhfr - CHO cell line DXB-11 (Urland et al., Proc. Natl. Acad. Sci. USA 77, 4216-4220, 1980) by the calcium phosphate precipitation method (Chen et al., Mol. Cell. Biol. 7:2745-2751, 1987).
The transfected CHO cells were cultured for 3 weeks in a nucleoside-free αMEM selective culture medium containing 1 mM glutamine, 10% dialyzed Fetal Calf Serum (FCS), 100 U/ml penicillin and 100 μg/ml streptomycin. The selected CHO cells were screened by the limiting dilution method, and a single monoclonal CHO cell line was obtained. The CHO cell clone was amplified in 20 nM to 200 nM concentration methotrexate (MTX), to obtain the human SIL-6R-producing CHO cell line 5E27.
The CHO cell line 5E27 was cultured in Iscove's modified Dulbecco's medium (IMDM, product of Gibco Co.) containing 5% FCS, the culture supernatant was recovered, and the sIL-6R concentration in the culture supernatant was measured by the ELISA (Enzyme-Linked Immunosorbent Assay) method according to the common procedure.
Reference Example 2
Preparation of human IL-6 antibody
Human IL-6 antibody was prepared according to the method of Matsuda et al. (Eur. J. Immunol. 18:951-956, 1988).
BALB/c mice were immunized with 10 μg of recombinant IL-6 (Hirano et al., Immunol. Lett., 17:41, 1988) together with Freund's complete adjuvant, and this was continued once a week until anti-IL-6 antibodies were detected in the blood serum.
Immunocytes were extracted from the local lymph nodes, and polyethylene glycol 1500 was used for fusion with the myeloma cell line P3U1. Hybridomas were selected according to the method of Oi et al. (Selective Methods in Cellular Immunology, W. H. Freeman and Co., San Francisco, 351, 1980) using HAT culture medium, and a human IL-6 antibody-producing hybridoma line was established. The human IL-6 antibody-producing hybridoma was subjected to IL-6 binding assay in the following manner.
Specifically, a soft polyvinyl 96-well microplate (product of Dynatech Laboratories, Inc., Alexandria, Va.) was coated overnight with 100 μl of goat anti-mouse Ig antibody (10 μl/ml, product of Cooper Biomedical, Inc., Malvern, Pa.) in a 0.1M carbonate-hydrogen carbonate buffer solution (pH 9.6) at 4° C. The plate was then treated for 2 hours at room temperature with PBS containing 100 μl of 1% bovine serum albumin (BSA). After washing with PBS, 100 μl of hybridoma culture supernatant was added to each well, and incubation was conducted overnight at 4° C.
The plates were then washed and 125 I-labelled recombinant IL-6 was added to each well to 2000 cpm/0.5 ng/well, and after washing, the radioactivity of each well was measured with a gamma counter (Beckman Gamma 9000, Beckman Instruments, Fullerton, Calif.). Of 216 hybridoma clones, 32 hybridoma clones were positive for the IL-6 binding assay. Among these clones there was finally obtained the stable clone MH166.BSF2. The IL-6 antibody MH166 produced by this hybridoma has an IgG1K subtype.
The IL-6-dependent mouse hybridoma cell line MH60.BSF2 (Matsuda et al., Eur. J. Immunol. 18:951-956, 1988) was then used to determine the neutralizing activity of MH166 antibody on growth of the hybridoma. MH60.BSF2 cells were dispensed at an amount of 1×10 4 /200 μl/well, a sample containing MH166 antibody was added thereto, culture was performed for 48 hours, and 15.1 Ci/mmol of 3 H-thymidine (New England Nuclear, Boston Mass.) was added, after which culture was continued for 6 hours.
The cells were placed on glass filter paper and treated with an automatic harvester (Labo Mash Science Co., Tokyo, Japan). Rabbit anti-IL-6 antibody was used as a control. As a result, MH166 antibody inhibited uptake of 3 H-thymidine by the MH60.BSF2 cells in a dose-dependent manner. This demonstrated that MH166 antibody neutralizes IL-6 activity.
Reference Example 3
Preparation of human IL-6 receptor antibody
Anti-IL-6R antibody MT18 constructed by the method of Hirata et al. (J. Immunol., 143:2900-2906, 1989) was bound to Sepharose 4B (product of Pharmacia Fine Chemicals, Piscataway, N.J.) activated with CNBr, according to the accompanying instructions, and the bound complex was used to purify IL-6R (Yamasaki et al., Science 241:825-828, 1988).
The human myeloma cell line U266 was solubilized with 1 mM p-paraaminophenylmethane sulfonylfluoride hydrochloride (product of Wako Chemicals) containing 1% digitonin (product of Wako Chemicals), 10 mM triethanolamine (pH 7.8) and 0.15M NaCl (digitonin buffer solution), and mixed with MT18 antibody bound to Sepharose 4B beads. The beads were then washed 6 times with digitonin buffer solution to obtain partially purified IL-6R for immunization.
BALB/c mice were immunized 4 times every 10 days with the partially purified IL-6R obtained from 3×10 U266 cells, and then hybridomas were prepared by conventional methods. The culture supernatants of the hybridomas from the growth-positive wells were examined for IL-6 binding activity by-the following method. After labelling 5×10 7 U266 cells with 35 S-methionine (2.5 mCi) they were solubilized with the aforementioned digitonin buffer solution. The solubilized U266 cells were mixed with a 0.04 ml of MT18 antibody bound to Sepharose 4B beads, and after washing 6 times with digitonin buffer solution, the 35 S-methionine-labelled IL-6R was washed off with 0.25 ml of digitonin buffer solution (pH 3.4) and neutralized with 0.025 ml of 1M Tris (pH 7.4).
A 0.05 ml of the hybridoma culture supernatant was mixed with 0.01 ml of Protein G Sepharose (product of Pharmacia). After washing, the Sepharose was incubated with 0.005 ml of the 35 S-labelled IL-6R solution prepared earlier. The immunoprecipitated substance was analyzed by SDS-PAGE, and the hybridoma culture supernatants reacting with IL-6R were examined. As a result, a reaction-positive hybridoma clone PM-1 was established. The IL-6R antibody PM-1 produced by hybridoma PM-1 has an IgG1K subtype.
The inhibiting activity of the antibody produced by hybridoma PM-1 against binding of IL-6 to human IL-6R was investigated using the human myeloma cell line U266. Human recombinant IL-6 was prepared with E. coli (Hirano et al., Immunol. Lett., 17:41, 1988) and 125 I-labelled with Bolton-Hunter reagent (New England Nuclear, Boston, Mass.) (Taga et al., J. Exp. Med. 166:967, 1987).
4×10 5 U266 cells were cultured at room temperature in the presence of a 100-fold excess of non-labelled IL-6 for one hour, together with 70% (v/v) of hybridoma PM-1 culture supernatant and 14000 cpm of 125 I-labelled IL-6. A 70 μl sample was overlaid onto 300 μl of FCS placed in a 400 μl microfuge polyethylene tube, and after centrifugation the radioactivity on the cells was measured.
As a result it was demonstrated that the antibodies produced by hybridoma PM-1 inhibited binding of IL-6 to IL-6R.
Reference Example 4
Preparation of mouse IL-6 receptor antibody
Monoclonal antibodies against mouse IL-6 receptor were prepared by the method described in Japanese Patent Application No. 6-134617.
Following the method of Saito et al. (J. Immunol., 147, 168-173, 1993), CHO cells producing mouse soluble IL-6 receptor were cultured in IMDM medium containing 10% FCS, and the mouse soluble IL-6 receptor was purified from the culture supernatant using the mouse soluble IL-6 receptor antibody RS12 (see ibid. Saito et al.) and an affinity column immobilizing Affigel 10 gel (Biorad).
A 50 μg of the obtained mouse soluble IL-6 receptor was mixed with Freund's complete adjuvant and intraperitoneally injected into Wistar rats (Nihon Charles River Co.). Booster immunizations were given with Freund's incomplete adjuvant after 2 weeks. On the 45th day the rats were butchered, and about 2×10 8 splenic cells thereof were used for cell fusion with 1×10 7 mouse P3U1 myeloma cells by a conventional method utilizing 50% PEG1500 (Berlinger Mannheim), after which the hybridomas were screened with HAT medium.
After adding the hybridoma culture supernatants to an immunoplate coated with rabbit anti-rat IgG antibody (Cappel Co.), mouse soluble IL-6 receptor was reacted therewith and the hybridomas producing antibodies against mouse soluble IL-6 receptor were screened by the ELISA method using rabbit anti-mouse IL-6 receptor antibody and alkali phosphatase-labelled sheep anti-rabbit IgG. The hybridoma clones in which antibody production was confirmed were subjected to subscreening twice to obtain a single hybridoma clone. This clone was named MR16-1.
The neutralizing activity of the antibody produced by this hybridoma against mouse IL-6 signal transduction was investigated by incorporation of 3 H-thymidine using MH60.BSF2 cells (Matsuda et al., J. Immunol. 18, 951-956, 1988), MH60.BSF2 cells were added to a 96-well plate to 1×10 4 cells/200 μl/well, and then mouse IL-6 (10 μg/ml) and MR16-I antibody or RS12 antibody were added to 12.3-1000 ng/ml prior to culturing at 37° C., in 5% CO 2 for 44 hours, after which 3H-thymidine (1 μCi/well) was added and the uptake after 4 hours was measured. As a result, MR16-1 antibody was found to inhibit uptake of 3 H-thymidine by MH60.BSF2 cells.
Experiment 1
Establishment of chronic rheumatoid arthritis-derived synovial cell line
(1) Preparation of synovial cells
Synovial tissue was obtained during surgical operation on the joint of a chronic rheumatoid arthritis patient. The synovial tissue was minced with scissors and then subjected to enzymatic dissociation by incubation for one hour at 37° C. with 5 mg/ml of TYPE I collagenase (product of Sigma Chemical Co.) and 0.15 mg/ml of bovine pancreatic DNase (product of Sigma Chemical Co.) in IMDM (Iscove's modified Dulbecco's medium), and passed through a mesh to obtain singule cells. These obtained cells were then cultured overnight in a culture flask using IMDM containing 5% FCS, after which the non-adherent cells were removed to obtain the synovial cells. The synovial cells were passaged 3 to 6 times and used for the following experiment.
(2) IL-6 production by synovial cells
The synovial cells obtained as described above were suspended in IMDM culture medium containing 5% FCS (product of Hyclone Laboratories Inc.), 10 U/ml of penicillin G and 100 μg/ml streptomycin to an amount of 3 ×10 3 cells/well, and were then cultured in 96-well microtiter plate (product of Falcon Co.), which human interleukin-1β (IL-1β), human tumor necrosis factor α (TNFα), human platelet-derived growth factor (PDGF)AB and human basic fibroblast growth factor (bFGF) were added to concentrations of 0.01 or 0.1, 0.1 or 1, 1 or 10 and 1 or 10 ng/ml, respectively, and upon culturing at 37° C. for 72 hours the culture supernatants were collected.
A 100 μl of anti-human IL-6 antibody MH166 (1 μg/ml) was added to a 96-well ELISA plate (Immunoplate: product of Nunc Co.) and incubated at 4° C. for 24 hours. Each well was subsequently washed with PBS containing 0.05% Tween20, and blocked at 4° C. overnight with PBS containing 1% BSA. The culture supernatants obtained previously were then diluted with PBS containing 1% BSA, added to the wells, and then incubated at room temperature for 2 hours. After washing with PBS containing 0.05% Tween20, 2.5 μg/ml of rabbit polyclonal anti-human IL-6 antibody purified with a 100 μl protein A column (product of Pharmacia) was added.
After incubating at room temperature for 2 hours, the rabbit polyclonal anti-IL-6 antibody binding to IL-6 in the culture supernatants was reacted with alkali phosphatase-bound anti-rabbit IgG antibody (product of Tago Co.). And then 1 mg/ml of Sigma104 alkali phosphatase substrate (product of Sigma Co.) was added according to the attached instructions and the absorbance at 405-600 nm was measured with an MPR A4 microplate reader (product of Tosoh Co.).
Calibration curves were prepared for the recombinant IL-6 during each assay for conversion of the absorbance OD values to human IL-6 concentrations. The results are given in Table 1.
TABLE 1______________________________________Augmented IL-6 production from synovial cellTreatment (ng/ml) IL-6 (ng/ml)______________________________________Untreated 0.096 ± 0.012IL-1β 0.01 6.743 ± 0.178 0.1 17.707 ± 0.259TNFα 0.1 0.575 ± 0.008 1 1.688 ± 0.034PDGF-AB 1 0.163 ± 0.035 10 0.165 ± 0.016bFGF 1 0.181 ± 0.009 10 0.230 ± 0.019______________________________________ Note: The synovial cells were cultured for 3 days with IL1β, TNFα, PDGFAB or bFGF. After culture, the IL6 concentrations of the supernatants were measured by ELISA.
The results demonstrated that IL-1β strongly promotes IL-6 production by synovial cells.
Example 1
(1) The synovial cells obtained in Experiment 1 (3 ×10 3 /well) were suspended in IMDM culture medium containing 5% FCS (product of Hyclone Laboratories, Inc.), 10 U/ml of penicillin G and 100 μg/ml of streptomycin and were then added into a 96-well microtiter plate (#3072, product of Falcon Co.) and cultured for 5 days in the presence of various concentrations of IL-6 or sIL-6 alone, or in the presence of both IL-6 and sIL-6R. At 72 hours after starting the culturing, 3 H-thymidine (product of Amersham International plc) was added to each well to 1 μCi/well, and after the culturing was completed the radioactivity in the cells was measured with a scintillation counter. The results are shown in FIG. 1.
As a result, the 3 H-thymidine uptake of the synovial cells was low with IL-6 or sIL-6R alone, and no growth of synovial cells was observed. In contrast, in the presence of at least a 10 ng/ml concentration of IL-6 and 100 ng/ml concentration of sIL-6R, significant uptake of 3 H-thymidine was observed compared to the control group. Thus, while virtually no growth effect on synovial cells was exhibited with IL-6 alone, in the presence of both IL-6 and sIL-6R a powerful synovial cell growth effect was clearly produced.
(2) Synovial cells (3×10 3 /well) were cultured in the presence of a sufficient amount of IL-β to produce IL-6 (0.1 ng/ml), 100 ng/ml of sIL-6R and 25 μg/ml of IL-6 antibody or 25 μg/ml of IL-6R antibody. At 72 hours after the start of culturing, 3 H-thymidine was added to each well to 1 μCi/well, and after the culture was completed the radioactivity in the cells was measured with a scintillation counter. The results are shown in FIG. 2. Addition of IL-6 antibody or IL-6R antibody completely suppressed the growth of synovial cells augmented by sIL-6R.
(3) Synovial cells (3×10 3 /well) were cultured in the presence of 100 ng/ml of IL-6 (product of Genzyme Co.), 100 ng/ml of sIL-6R and 25 μg/ml of IL-6 antibody or IL-6R antibody, which were obtained in the above-mentioned Reference Examples. At 72 hours after the start of culture, 3 H-thymidine was added to each well to 1 μCi/well, and after the culture was completed, the radioactivity in the cells was measured with a scintillation counter. The results are shown in FIG. 3. Addition of IL-6 antibody or IL-6R antibody completely suppressed the growth of synovial cells augmented by sIL-6R.
Example 2
The suppressing effect of IL-6 receptor antibody on onset of arthritis was investigated using a mouse arthritis model.
A bovine type II collagen solution (Collagen Technology Research Group) (4 mg/ml) dissolved in a 0.1N aqueous acetic acid solution and complete adjuvant H37Ra (DIFCO) were mixed in equivalent amounts, to prepare an adjuvant. A 100 μl of the adjuvant was subcutaneously injected at the base of tail of 8- to 9-week-old female DBA/1J mice (Charles River Japan). An additional 100 μl was injected 20 days later under the dorsal skin to induce arthritis.
Mouse IL-6 receptor antibody MR16-1 was intravenously administered at 2 mg per mouse upon first collagen sensitization, and each mouse was subcutaneously injected with an additional 0.5 mg (n=5) each week thereafter for 7 weeks. As a control, anti-DNP antibody KH-5 (Chugai Seiyaku) of the same isotype was used (n=5).
The severity of arthritis was evaluated based on an arthritis index. The evaluation was based on a 4 point scale for each limb, for a total of 16 points per individual. The evaluation standard was as follows.
0.5: Erythema observed at one site of joint.
1: Erythema observed at two sites of joint, or redness but no swelling of dorsa.
2: Moderate swelling observed.
3: Severe swelling of pedal dorsa, but not reaching all of the digits.
4: Severe swelling of pedal dorsa and digits.
The results are shown in FIG. 4. Onset of arthritis from early stage arthritis was clearly suppressed in the IL-6 receptor antibody-administered group, compared to the control antibody-administered group.
On the other hand, the results of measurement of the anti-type II collage antibody titer in the mouse blood showed a significant reduction from early stage arthritis in the IL-6 receptor antibody-administered group compared to the control antibody-administered group (FIG. 5).
The mice were sacrificed on the 35th day after collagen immunization, and the hind legs were fixed with 20% formalin. They were then subjected to demineralization in an EDTA solution (pH 7.6) and dewatering with alcohol. They were subsequently wrapped in paraffin and cut to 2 μm thick sections. The sections were stained with hematoxylin and eosin and observed under 125×magnification (FIG. 6). As a result, invasion of granulation tissue into the cartilage and bone, i.e. chronic proliferative synovitis was suppressed in the IL-6 receptor antibody-administered group compared to the control antibody-administered group.
IL-6 is a cytokine which induces differentiation of B cells into antibody-produc-ing cells. IL-6 also promotes proliferation of synovial cells in the presence of IL-6 receptor. Since in mouse collagen arthritis models, anti-IL-6 receptor antibody significantly suppressed anti-type II collagen antibody titers on the 21st and 35th days after collagen sensitization, compared to the control antibody-administered group, it is believed that the antibody production inhibition by anti-IL-6 receptor antibody is one factor responsible for the suppressing effect on arthritis. Moreover, although no suppression of antibody production was observed from the 49th day after collagen sensitization, the fact that an adequate suppressing effect on onset of arthritis was exhibited even during this period, and that HE staining of tissue surrounding the tarsal bone showed suppressed invasion of granulation tissue into the cartilage and bone of the anti-IL-6 receptor antibody-administered group compared to the control group, the synovial growth-suppressing effect is also believed to contribute to the arthritis-inhibiting effect.
INDUSTRIAL APPLICABILITY
Synovial cells from chronic rheumatoid arthritis patients proliferate in the presence of both IL-6 and sIL-6R. The fact that synovial fluid of chronic rheumatoid arthritis patients contains a sufficient amount of IL-6 and sIL-6R to induce growth of synovial cells suggests that signal transduction by IL-6 is involved in abnormal growth of synovial cells in chronic rheumatoid arthritis.
It has thus been conclusively demonstrated that a chronic rheumatoid arthritis therapy whose effective component is an IL-6 antagonist according to the present invention suppresses growth of synovial cells in chronic rheumatoid arthritis patients in the presence of IL-6 and sIL-6R, and thus has a therapeutic effect against chronic rheumatoid arthritis. Consequently, the IL-6 antagonist of the invention is useful as a therapeutic agent for chronic rheumatoid arthritis-in which abnormal growth of synovial cells occurs. | Methods for inhibiting synovial cell growth and treating chronic rheumatoid arthritis are provided. The methods comprise administering a pharmaceutical composition comprising an interleukin-6 antagonist, such as an anti-IL-6 receptor antibody, and a physiologically acceptable carrier. | 8 |
FIELD OF THE INVENTION
The present invention is directed to improvements in the area of powered door opening systems, methods and apparatus. The present invention has particular application for opening and closing garage doors.
BACKGROUND OF THE INVENTION
Mechanized door openers have become very prevalent in homes and many commercial establishments. These devices are designed to open the door upon receipt of a signal from a keyboard, horn, pressure of tires or footsteps on a sensor etc. Garage doors are a major market for many of these devices. Garage door openers have become ubiquitous in many communities. There are a number of problems with garage door openers, however. One of the problems with garage door openers is the issue of security. Until recently, many garage door openers had a limited number of security codes and as a result, there was a risk that-someone other that the home owner could open the garage by using the same manufacturer's transmitter. In addition, the security code was typically permanently installed in the garage door opener and lost transmitters could give unauthorized persons access to the premises.
A second issue with respect to garage door openers is the issue of injury to persons and property in the closing of the doors. Government standards require that there be at least two method of determining whether there is an obstruction in the path of travel. One common approach is the use of a light beam that passes from one side of the opening to the other. If an object or person is present in the path of travel, the light beam is broken and the downward travel of the door is halted. Insofar as the second means of determining whether there is an obstruction present, there are a number of approaches on the market. On approach that has been used is to ascertain whether the speed of the closing door has changed. These methods measure the speed and compare it to a base figure obtained from previous unobstructed closings. If the closure is taking longer the opener concludes there is an obstruction and terminates closure. Other approaches are also currently available.
Garage door opener setup is another area that can create problems for the installer. Once the garage door opener is installed on the door then the door opener must be adjusted so that the door reaches the ground surface on closing thus eliminating any gaps to permit ingress of vermin, cold air, and debris. Similarly, adjustment is also necessary to make sure (1) that the garage door will reverse its direction upon contact with a person or an obstruction; and (2) that the garage door is not damaged on closing because it is hitting the ground. Also needed to be adjusted after installation is the force of closure. Too great a closing force can injure a person or damage the door upon closing.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a system for opening and closing doors particularly garage doors.
It is an object of the invention to provide a garage door opener that has two upward speeds of travel, a first or initial lifting speed to provide quick opening of the door and a second slower speed to prevent damage to the door and or the opener as the door is raised.
It is another object of the invention to provide a garage door opener that has two downward speeds of travel, a first or initial speed to provide quick movement of the door to overcome inertia, and a second slower speed to provide a “soft stop” door closure.
It is an object of the present invention to provide improved security for communication between the motor control unit and a handheld RF operational control unit and/or the RF linked operational control unit that is mounted on a structure.
It is an object of the present invention to provide a garage door opener with an indoor panel functioning both as a control unit and a diagnostic information unit.
It is another object of the invention to provide a garage door opener with an indoor control panel designed in a modular fashion to provide control for two or more garage door openers.
It is a further object of the invention to provide a garage door opener with a keyless entry panel that will control two or more individual openers even when the openers are placed in the vacation mode.
It is a still further object of the invention to provide a garage door opener with an indoor control panel that connects to “off the shelf” motion sensors that cause an opener's built in lights to illuminate when motion is sensed.
SUMMARY OF THE INVENTION
The present invention is directed to an improved garage door opener. More and more homes these days are provided with two or three garage doors. Garage door openers operate a single garage door. In applications where there is more than one garage door, the homeowner has to install multiple garage door openers and their respective control panels. With traditional garage door openers, each door opener had to have separate wiring extending from each garage door opener to their respective wall panel located in the garage. Running the wiring for this arrangement was time consuming and required running the wire from each opener to its respective control panel usually along one or more walls to the wall panel. In the present invention a second garage door opener can be wired directly to a first garage door opener and the second wall mounted control panel can be connected directly to the wall panel for the first garage door opener.
The garage door of the present invention is provided with a first microcontroller in the wall panel and a second micro controller in the drive unit. Each microcontroller has a digital bus and are connected by preferably three wires because of the volume of date that is transferred from microcontroller to microcontroller. A first wire is typically a return ground wire. The second wire is used for data transfer. The third wire is for a clock. In accordance with the present invention, there may be multiple up to a total of 256 motor control units, i.e., openers, or wall units that may be connected together. This permits the homeowner to locate the wall units at more than one location in the garage for additional convenience.
The garage door opener of the present invention also permits the door speed to vary during operation. One of the issues with many current garage door openers is the amount of time it takes the door to open and close. The present invention permits the door to open and close rapidly until a preselected distance from the end of travel is reached. For example, the garage door of the present invention operates downwardly at a higher rate of travel until a selected point is reached. At that point, the control logic signals the motor to slow the door so that the door does not impact the floor of the garage with a great force thereby risking damage to the door. Similarly, when the door is rising, the door initially travels at a higher rate of speed until a preselected distance from the end of door travel is reached. When that preselected distance is reached the control logic signals the motor to slow the door so that the door does not damage the garage door opener. For downward travel the preselected point for slowing the door can be any distance from the floor, however, a distance of about 18″ has been found satisfactory. For the travel of the door when it is opening, any distance may be selected. Usually about 12″ from the termination point has been satisfactory. The microcontroller of the present invention controls the motor speeds and constantly calculates where the door is and compares it to a figure in memory. When the appropriate location is reached, the microcontroller signals the motor to slow down by changing one of the output pins on the microcontroller.
The drive unit of the garage door opener of the present invention is provided with an optical sensor mounted on a gear wheel that is caused to rotate by the belt. The microcontroller counts the revolutions of the wheel as it is turned by the belt and knows where the door is. This permits the microcontroller to learn when to stop the door and when to slow it down if there is a problem with the speed of the door, i.e., if there is binding of the door in the tracks, an obstruction present, a drop in the line voltage or if there is a mechanical problem such as a broken spring, wheel, etc.
The garage door opener of the present invention may also have an improved locking mechanism. The microcontroller controls an output pin that locks the drive gear connected to the motor. The locking mechanism has to be disengaged prior to each start of the motor and engaged after the motor ceases. The locking and/or unlocking of the opener before each action of the motor prevents the motor from operating while the opener is in a locked position. The method of the present invention controls the timing when the motor operates and when the lock is locked or unlocked. The method of the present invention also determines when the lock is to be engaged or disengaged and also tells the motor when the door has reached the end of travel and shuts the motor off. In a preferred embodiment, the present invention starts up the motor a short time after the lock disengages. The amount of time from the release of the lock and the engagement of the motor can vary but is usually in the vicinity of about 200 milliseconds after the disengagement of the lock. when the door is on the way down, the solenoid of the locking mechanism stays open until it reaches the full bottom limit or reaches an obstruction. if the door does not reach the fully down position due to, for example, a binding or an obstruction power to the solenoid causes the brake to be released. If the light beam is impeded the microcontroller will cause the door to cease its downward travel and reverse its direction of travel. Power to the solenoid will remain on until the door reaches its fully opened position.
In another embodiment of the present invention the outdoor keypad of the opener may be provided with a switch to turn on or off the light in the opener in the garage.
In a still further embodiment of the invention the door speed changes are measured based on a formula taking into consideration the time and speed and a number is calculated which creates a tolerance window. The force adjustment range is based on the number so calculated. This calculation is made approximately 16 times per second during operation and compared to the tolerance window but can be adjusted so that the calculation is made at other intervals greater than or less than 16 times per second. The tolerance window that is created is updated about 16 times per second. If there are problems with, for example, the line voltage, then the force calculation range shifts as the door operates. If there is an obstruction, the number will be outside the tolerance window and the opener will cease movement of the door.
In another embodiment, there may be an outdoor keypad usually placed on the outside wall of the garage or other structure. This outdoor keypad is able to control two doors. There is a user password that preferably has eight digits instead of the usual four digits. Typically, there are three different passwords, a primary, a secondary and an override. The primary password enables a person to change the settings on the keypad. The override password is used to override the vacation lock.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an example of a door system used to operate a door in accordance with the present invention.
FIG. 2 shows the data bus used to carry data among the terminals connected on the bus.
FIG. 3 shows the relationship between the terminal and the clock line.
FIG. 4 shows the Hardwired Operational Control Unit
FIG. 5 shows the RF Linked Operational Control Unit.
FIG. 6 is a schematic of the Motor Control Unit Software
FIG. 7 is a schematic drawing of the Initialization of the Motor Control Unit System.
FIG. 8 shows the Main Executive portion of the Motor Control Unit Software program.
FIG. 9 shows the Motor Monitor of the present invention.
FIG. 10 shows the Console (Send & Receive) Communication function of the Motor Control Unit System of the present invention.
FIG. 11 shows the EEprom Store/Retrieve function of the Motor Control Unit System of the present invention.
FIG. 12 shows the RF (remote) Communication function of the Motor Control Unit System.
FIG. 13 shows the Button and Programming function of the Motor Control Unit System.
FIG. 14 shows the Light, Sound and Reverse Motor function of the Motor Control Unit System.
FIG. 15 shows the Operational Control Unit Software of the present invention.
FIG. 16 shows the Initialization of the operational control unit.
FIG. 17 shows the Main Executive of the operational control unit.
FIG. 18 shows the Button function of the operational control unit.
FIG. 19 shows the Accessory function of the operational control unit.
FIG. 20 shows the Communication (Talk, Listen) function of the operational control unit.
FIG. 21 shows the Process Clock function of the operational control unit.
FIG. 22 shows the Display function of the operational control unit.
FIG. 23 shows the Remote Operational Control Unit Software Operation.
FIG. 24 shows the initialization function of the Remote Operational Control Unit Software Operation.
FIG. 25 shows the main executive function of the Remote Operational Control Unit Software Operation.
FIGS. 26 show the program function of the Remote Operational Control Unit Software Operation.
FIG. 27 shows the EE memory function of the Remote Operational Control Unit Software Operation.
FIG. 28 shows the clock function of the Remote Operational Control Unit Software Operation.
FIG. 29 shows the send routine function of the Remote Operational Control Unit Software Operation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates primarily to overhead doors i.e., doors that are raised to open them as opposed to doors that swing open and shut. Doors that have particular applicability for the present invention are garage doors that ride on a track. The preferred doors of the present invention are typically provided with a plurality of rollers that are attached on either side of a door. The rollers ride in tracks that guide the door as it is opened and closed. These tracks are attached to the frame of the structure. The doors are raised and lowered by a mechanical garage door opener. An example of an apparatus for opening and closing a garage door is shown in co-pending U.S. patent application Ser. No. 09/875,794 and U.S. Design patent application Ser. No. 29/143,216 filed concurrently herewith the disclosures of which are incorporated herein by reference. It will be appreciated by those skilled in the art that the present invention can be used with other types of garage door openers or with other mechanisms for opening an overhead door, such as a security door and others.
The operation of the garage door of the present invention is described with respect to the preferred embodiment as follows:
The garage door opener of the present invention has a motor control unit that operates the motor for raising or lowering tile door. The motor control unit has a microcontroller, preferably a “PIC” microcontroller, one or more control switches and a photo detector. The photo detector may detect breaks in a beam of any type of light including visible, infrared, etc. The motor control unit may also be provided with a motor speed sensor, a light device, and/or a sound device. The motor control unit receives control data and initiates a corresponding motor, light and/sound action.
One of the sources of data for the motor control unit is the operational control unit or wall console. This unit is typically mounted on a wall of the structure that has a door to be opened. This wall unit is preferably hardwired to the motor control unit. The wall unit has a microcontroller, preferably a “PIC” microcontroller, one or more panel switches, one or more indicator means and a connection for a motion detector.
Another source of data for the motor control unit is the wireless keypad. The keypad has a microcontroller, preferably a “PIC” microcontroller. The keypad may also have keypad switches and a panel light.
Control Panel and Program Set Up
Upon first power-up of the garage door opener system it will be non-initialized and in the Manual/Learn mode. Non-initialized is the condition where the opener has no stored travel or force values. The lights will flash and remain on for 5 minutes and the audible alarm will sound. In addition, the Wall Unit “SAFETY” LED will momentarily flash ON and then turn OFF. All adjustments are performed using the three program buttons located on the head unit.
Initializing Door Travel
Before the door travel can be adjusted, it is necessary to move the belt trolley to a position so that the door arm can be attached to the door. The trolley can be moved manually by depressing either the “+” or “−” buttons on the head unit. The “+” button moves the door towards the closed (down) position and the “−” button moves the door towards the open (home) position. Either button must be held down for ½ second for the system to react.
The door may continue moving until the buttons are released. If the door encounters a binding or obstruction condition, which stops its travel, the system will turn off power to the motor. This condition must be corrected before the door can be manually moved again.
Once the door arm is attached to the door in its maximum closed position activate the system by depressing the “UP/DOWN” button on the Wall Unit. The door will start in the up direction until the “Home” Switch is reached. The Wall Unit “UP/DOWN” switch is the method of activating the door when the opener is in a non-initialized state. Once the door stops, double check its travel by again activating the Wall Unit “UP/DOWN” switch. The door should return to its initial down starting position. Holding down either the “+” or “−” button will no longer move the door. When depressing the “+ or −” buttons the door travel will be changed by {fraction (3/16)} inch for each depression of the button, and this change Will take place on the next door movement cycle.
The opener has now learned its travel. If travel or force adjustments must be made, please refer to our next section.
The system may be reset into its original Non-Initialized state by:
Re-Initializing Door Travel
Momentarily remove power to the unit by pulling out the AC line cord, and then reinsert the line cord into the AC supply with the “PROG” button held depressed. The audible alarm will sound and then release the “PROG” button. When this is complete, the system is now reset and ready to repeat the initialization procedure.
Force Adjustments
All adjustments can be preformed from the three program buttons located on the unit.
Adjusting the Force
Force adjustments control the amount of power needed to open and close the door. The opener is designed to stop the door in the up direction if anything interferes with its travel. Likewise, the door will reverse and return to the home position if anything interferes when it is moving in the down direction. This includes binding or an unbalanced condition.
It should be noted that the force should not be set too light because this could lead to unnecessary stops or reversals.
In order to program the new garage door opener's open and close force limits it is necessary to enter program menu. The program menus settings are as follows. The audible alarm will sound with each step with each depression of the PROG button.
First Depression: Up Force adjustment
Second Depression: Down Force Adjustment
Third Depression: Car Remote Transmitter programming
Forth Depression: Exit program mode (alarm will sound twice)
Up Force Adjustment: Depress the PROG button once to enter this mode and then depress either the “+” or “−” buttons for adjustment. To complete the operation, depress the PROG three more times to store the value and exit the adjustment mode.
Down Force Adjustment: Depress the PROG button twice to enter this mode and then depress either the “+” or “−” buttons for adjustment. To complete the operation, depress the PROG two more times to store the value and exit the adjustment mode.
The opener should be run through a complete cycle, open/close after each adjustment.
Wall Unit
The Wall unit indicates difficulties during use of the garage door opener as well as controlling the opening and closing of the garage door.
LOW BATTERY: Illuminates when car remote's battery is low. Change Car Remote battery as soon as possible.
SAFETY FAULT: Illuminates when photo eye sensors have been tripped or there is a door jam.
LOCK: Illuminates when the system vacation lock is engaged
Programming Car Remote
The garage door opener is usually provided with two start-of-the-art Car Remote Transmitters. Each transmitter has the ability to operate up to three head units.
Depress the PROG button located on the head unit three times to enter this mode and then depress the “+” button to enter the LEARN mode.
Depress any Car Remote Transmitter button twice. Pause in-between presses. To complete the operation, depress the PROG button once.
Initiate door travel by depressing the button just programmed. Hold the button depressed until door begins to move. If door does not function, re-program the button carefully following the instructions above. If door still does not function, call the customer service line.
Operation of the Garage Door Opener
The garage door opener can be activated (operated) using the following accessories:
Wall Unit
Car Remote Transmitter
Wireless Keypad (Optional)
Motion Sensor (Optional—Only turns on lights)
Operating the Garage Door Opener via the Car Remote Transmitter
Depress the button that has been previously “programmed” and hold until door begins to move and then release button.
If necessary the garage door may be stopped and restarted via your “programmed” Car Remote Transmitter button.
Operating Your Garage Door Opener via the Wall Unit
Depress and hold the main motor control button on the Wall Unit until door begins to move.
Release the main motor control button. The opener may be stopped and restarted via this main motor control button.
Audible Alarm (System Enunciator)
The garage door opener may have an integrated safety enunciator, which will sound whenever the system encounters impedance to door movement.
Depress the enunciator button on the Wall Unit to stop the enunciator from sounding.
Vacation Lock Mode
The garage door opener may have the capability to be put in a vacation lock mode. When activated, the vacation lock mode disables the Wall Unit and Car Remote Transmitters from opening the door. The only means of opening the door is via the optional Wireless Keypad (when supplied), or by disabling the vacation lock using the VACATION LOCK button located on the Wall Unit.
To initiate vacation lock, depress the VACATION LOCK button located on the Wall Unit. The VACATION LOCK LED will illuminate when in use.
To disable the vacation lock, depress the VACATION LOCK until the VACATION LOCK LED is extinguished.
Light On/Off
The garage door opener preferably has an internal light fixture, which can be manually operated via the Wall Unit. Normally the lights will automatically illuminate whenever the opener is activated to either open or close the door. The lights stay on for 5 minutes. The LIGHT button, located on the Wall Unit will override the automated feature. Depressing the LIGHT ON/OFF button on Wall Unit will toggle the internal lights located on the head unit. When the lights have been manually turned on the automatic light timer is disabled. To turn the lights off, depress the LIGHT ON/OFF button AGAIN.
Optional Motion Sensor
The garage door interface with a motion sensor by plugging in the male telephone jack into the correct female socket located on the Wall Unit. The corresponding Wall Unit socket is marked via a motion sensor icon.
Wait 4 minutes. This allows the system to set itself. The motion sensor is now active; any movement in front of the sensor will turn on the lights in your head unit. The system resets after 5 minutes, but will stay on if movement is present.
I. Door Opener (GDO) System
1.0 Functional Requirements
The GDO system (FIG. 1) is preferably used to operate a garage doors with the following requirements:
The system may operate 1 or 2 or more doors independently of each other using either one indoor control panel or one outdoor keypad control panel or any one of a number of car remote control units.
The doors being control should operate at 2 speeds of travel.
At start up, approx. 10-17 inches per second and more preferably 13-15 inches per second.
After initial start up, @ approx. 5-8 and more preferably 6-7 inches per second.
The system should operate a light and a sound device for each door connected to the system.
The light device may be activated for each door movement and remain active for a minimum of about 4-5 minutes.
The sound device may be activated to indicate a failure with the door movement and preferably remain active until an operator interaction.
The system should monitor the door movement and prevent any door movement should the door encounter any obstruction or should a speed change indicate a door binding condition.
The system shall monitor the door run count vs. time and prevent excessive motor operation within a preset time period.
The Following specifications typically apply to the system of the present invention but are not limited thereto:
1. No door operation should take place without an operator action.
2. A setup procedure is normally needed after initial installation before proper door operation can be realized.
3. No Door Motor action should be taken at power up.
4. The Hardwired Operational Control Unit (OCU) should communicate with the Motor Control Unit (MCU) using a bi-directional serial bus.
5. Both the Handhold RF linked Operational Control unit and the RF linked Operational Control unit should incorporate a secure data transmission link to the Motor Control unit.
6. The system should provide for configuration of 2 Hardwired Operational Control Units (OCU) and 2 Motor Control Units (MCU).
II. Motor Control Unit (MCU) Operating Specifications
1.0 The Motor Control Unit may receive control data and initiate a corresponding motor, light or sound action.
2.0 Software Operating Requirements
Preferably, a “PIC” micro controller performs the interfacing and control functions between a preferred “HCS500” decoder device, an Indoor console panel and all the Sensors, Switches, Lights, Indicators and Motor relays needed for proper door operations. The HCS500 may contain all the necessary software needed to decode transmitted data received from any RF linked operational control device. The HCS500 should also contain a Serial # code and a Manufacture's ID code used for secure transmitter/receiver link operation.
3.0 The Following specifications preferably apply:
1. The “PIC” micro controller has internal non-volatile memory.
2. The “PIC” micro controller has No Sleep mode.
3. No operator interaction routine is needed for the “PIC” micro controller at power up.
4. A LIGHT device shall be incorporated in the Motor Control unit.
5. Linking each RF Operational Control unit to the Motor Controller shall require a “LEARN” procedure to be completed for each RF transmitter unit.
6. Pwr down shall not effect any Transmitter “LEARNED” code, Travel or Door Force setting data held in memory.
7. No Door Motor action shall be taken at power up.
8. All “LEARNED” codes shall be cleared from memory IF the “LEARN” button is held depressed during power up.
4.0 Preferred Hardware Configuration
1.) A “PIC” micro controller
2.) A set of control switches
3.) A Photo Detector.
4.) A motor speed sensor
5.) A light device
6.) A sound device
5.0 I/O configuration
TABLE 5.1
Inputs (qty)
Purpose
1. Travel Limit SW (1)
active LO signal indicating the door in the full
back position.
2. Program Button (1)
used to place Controller into program mode.
3. Plus (+) Button (1)
used in conjunction with program button
4. Minus (−) Button (1)
used in conjunction with program button
5. Infrared Det (1)
Active LO signal indicating the presence of an
obstruction in the path of the door.
6. Speed Sensor (1)
pulses indicating the speed of the door motor.
7. Address SW (2)
used to set Controller “Talk/Listen” serial
data address.
TABLE 5.2
Outputs (qty)
Purpose
1. Motor Relays (2)
signal controlling the direction and status a door
motor.
2. Speed Control (1)
signal controlling the motor speed
3. Light Relay (1)
signal controlling the power to an incandescent
light.
4. Sound Relay (1)
signal controlling the power to a sound device.
5 Brake Relay (1)
signal controlling the power to the belt brake device
6 HCS500 Reset
signal controlling the HCS500 device reset
TABLE 5.3
Bi-directional (qty)
Purpose
1. Serial Data (1)
Send/Receive serial data from the Indoor Console.
2. Clock Signal (1)
Sync signal used in conjunction with Serial Data.
3. Serial Data (1)
receive serial data from the HCS500 decoder.
4. Clock Signal (1)
sync signal used in conjunction with Serial Data.
6.0. Button Operation
Operator interaction is usually required to initialize the software program for proper operation.
6.1 Program Button
This button is used to toggle the software through the three operational adjustment modes.
Mode Function
1. Force up adjustment
2. Force down adjustment
3. Remote Transmitter Learn/Un-Learn command initiation
6.2 Plus (+) Button
In mode 4 this button is used to adjust the door position forward. One depression preferably equals 0.196 inches of total door travel. (The travel per depression may be set to any amount desired.)
If the button is held depress for about 4 seconds, the door will start moving forward until the button is released.
In mode 1 and 2 (section 6.1), this button shall increment the corresponding adjustment. In mode 3 this button shall initiate the Learn command.
6.2 Minus (−) Button
In mode 4 this button is used to adjust the door position back. One depression preferably equals 0.196 inches of travel. (Other distances can be set if desired.)
If the button is held depress for about ½ second, the door will start moving back until the button is released.
In mode 1 and 2 (section 6.1), this button shall decrement the corresponding adjustment. In mode 3 this button shall initiate the Un-Learn command.
7.0 Belt Travel, Door Force and System Failures
7.1 Belt Travel
7.1.1 Full Belt travel speed shall be defined at X″/sec. Half Belt travel speed shall be defined at X″/sec.
7.1.2 Belt travel is be monitored preferably using a belt speed sensor at a rate of 16 times for 3.14″ of belt travel (once every 0.196″). One (1) monitoring interval is defined as {fraction (1/16)} of 3.14″ belt travel.
A belt speed deviation factor of +2.5% & −2.5% has been incorporated in the speed checking routine. The deviation factor may vary as necessary.
7.1.3 From initial belt start to 1.07″ of travel, an average speed value shall be calculated and shall be used to calculate an “out of speed” belt condition.
7.2 Door Force
The operator force adjustment factor for both forward belt travel and reverse belt travel preferably is in increments of 1% of belt speed travel.
7.2.1 The reverse belt travel adjustment factor is defined as the UP Force. The forward belt travel adjustment factor is defined as the Down Force.
7.2.2 Belt speed Tolerance is defined as the sum of belt speed deviation factor plus either the UP Force factor or the Down Force factor.
Tolerance=Speed Deviation+Force Factor
This Tolerance is calculated at motor start and is depended on the belt direction.
7.3 System Failure
7.3.1 Belt Speed Failures
An “in tolerance” condition is defined as belt travel which is within the Belt travel tolerance define in section 7.2.2 for one (1) monitoring interval. An “out of tolerance” condition is defined as belt travel which is not within the Belt travel tolerance define in section 7.2.2 for one (1) monitoring interval.
Belt start up is defined as the period FROM the time power is applied to the belt drive motor TO the time the belt has traveled 1.5 inch OR TO the time the speed monitoring sensor records one “in tolerance” condition which ever occurs first.
At belt start up time, up to eight (8) continuous “out of tolerance” conditions can be recorded before a door failure situation is triggered.
From the end of belt start up time to normal belt shut time only four (4) continuous “out of tolerance” conditions can be recorded before a belt failure situation is triggered.
7.3.2 Obstruction Failures
A signal from an IR detector shall be checked at every monitoring interval define in section 7.2.1. Should this signal indicate an obstruction condition an obstruction failure situation should be triggered.
8.0 Terminal Handshaking and Data Transfer
8.0 This section describes the method for terminal handshaking and data transfer among the terminals connected to the Garage Door Opener System.
A “terminal” shall be defined as any unit connected to the common data bus of the Garage Door Opener System. (FIG. 1.)
A “common data bus' (“bus”) shall consist of one wire to carry data (“data line”) and one wire to carry a synchronous clock signal (“clock line”) among the terminals connected on the bus. (See FIG. 2)
8.1 Standby
8.1 In a standby condition the data line should be at a low voltage level and the clock line should be at a high level.
Any terminal connected to the bus should force the data line to a low level using its internal circuitry.
Any terminal connected to the bus should allow the clock line to remain at a high impedance state using its internal circuitry. An external circuit shall keep the clock line at a high level.
8.2 Bus Request
8.2.1 If any terminal connected to the bus initiates a request to send data to any other terminal on the bus the terminal initiating the request should bring the clock line to a low level.
8.2.2 The terminal initiating the request should wait for the other terminals on the bus to acknowledge the request. The request is acknowledged by the other terminals bring there data line to a high impedance state. An external circuit should bring the data line to a high level if all the other terminals acknowledge by bring there data line to a high impedance state.
8.2.3 Once all the terminal acknowledgments are recognized, the terminal initiating the request shall proceed to transfer data to the terminals connected on the bus.
8.3 Data Transfer
8.3.1 The terminal initiating the request should set the data line to the level that reflects the level of the first bit of data needed to be transferred. The terminal initiating the request should next set the clock line to a high level for 50 us which will signal all the other terminals that a valid data bit condition is present on the data line. The terminal initiating the request shall then bring the clock line back to a low level for 50 us. (FIG. 3)
8.3.2 Step 8.3.1 should be repeated until all data bit are transferred to all other terminals on the bus.
8.4. Serial Data Layout
8.4.1 Eight (8) data bits are preferably used in the terminal data transfer.
Two (2) data bits (bit 0,1) may be assigned for terminal addressing and Six (6) data bits (bits 2 - 7 ) may be assigned for data information.
8.4.2 A maximum of two (2) motor controller units (MCU) and two (2) operational control units (OCU) can be connected to the Garage Door Opener System bus in this embodiment.
8.4.3 Terminal addressing should be assigned as follows:
The motor controller units . . .
bit 1 shall always equal 0
bit 0 shall be either 0 or 1 (depending on the address switch position set on the MCU circuit card).
(Address=1x).
The operational control units . . .
bit 1 shall always equal 1
bit 0 shall be either 0 or 1 (depending on the address switch position set on the OCU circuit card).
(Address=0x).
TABLE 8.1
Terminal
MCU 1
MCU 2
OCU 1
OCU 2
Address* (Bit 1,0)
00
01
10
11
Value(h)
Command
Received* Data Word Assignments (Bits 2-7)
1
no assignment
2
on/off door action
3
toggle Lock function
4
sound off command
5
light on command
6
close door command
7
open door command
8
light on command
Send* Data Word Assignments (Bits 2-7)
1
activate Safety led
2
unused
4
activate Photo
8
activate LoBattery
10
activate Lock
12
activate Sound Off
(* w/ address sw set for 4 terminal operation)
(*note: MCU) See FIG_
9.0 MCU Software
The MCU software described in this section is preferably loaded into a microprocessor preferably a MicroChip #PIC16C57 device. This device has 2K(×12) bytes of user program memory.
9.1 Program Routines
Main
Purpose
1.
Init
load/set all program operating
parameters
2.
Main Loop
program flow control
3.
Motor
main motor control service routine
4.
Light
control light on/off timing
5.
Sound
control sound on/off timing
6.
Console Listen
used to take data from OCU
7.
Console Talk
used to send data to OCU
8.
Remote(HSC500) Listen
used to take data from HSC500
9.
Remote(HSC500) Talk
used to send data to HSC500
10.
Motor_On
turns motor on
11.
Motor_Off
turns motor off
12.
Spd_Delta
controls motor speed
13.
Reverse (travel)
belt directional control
14.
Button
takes data from operational buttons
15.
Tim/Overrun
controls motor operation vs. time
SubRoutines
Purpose
1.
Time delays
controls time delays within routines
2.
ComInit
prepares data for console
3.
RemInit
prepares data for HSC500
4.
Process data
translates data rec'd from console or
HSC500
5.
Dev_force
calculates motor deviation spec
6.
Force_tol
adjust motor force tolerance
7.
New_Position
tracks belt position
8.
Ave_spd
calculates motor average speed
9.
Speed_ck
calculates motor speed
10.
Zero_ck
monitors zero door position
III Operational Control Unit, Wall Console (OCU) Specifications
1.0 The Hardwired Operational Control (FIG. 4) Unit should allow an operator to send commands to the Motor Control Units (MCU). The following specifications preferably apply for a single OCU. Should a double OCU unit replace the single unit then this specification may apply for each OCU section of the double OCU.
2.0 Software Operating Requirements
Preferably, a “PIC” micro controller shall perform the interfacing and control between the Motor Controller and the console panel switches, indicators and an optional motion detector.
3.0 The Following preferred specifications apply:
3.1 The console has no internal non-volatile memory.
3.2 The console has No Sleep mode.
3.3 No operator interaction routine is needed for the “PIC” console at initial power up.
4.0 Preferred Hardware Configuration
1.) A “PIC” micro controller
2.) Panel switches
3.) Indictor
4.) Motion detector
5.0. I/O Configuration
TABLE 5.1
Inputs (qty)
Purpose
1. Up/Down Button (1)
Used to signal a door movement.
2. Lock Button (1)
Used to disable (lock) the Motor Controller.
3. Sound Button (1)
Used to disable the sound device.
4. Light Button (1)
Used to turn toggle door light.
5. Motion Sig
Used to detect area motion.
6. Address SW (1)
Used to set Console Talk/Listen serial data
address.
TABLE 5.2
Outputs (qty)
Purpose
1. Lock LED (1)
Used to indicate to Lock status.
2. Fault LED (1)
Used to indicate to door operational fault.
3. LO Bat LED (1)
Used to indicate to a LO battery condition.
TABLE 5.3
Bi-directional (qty)
Purpose
1. Serial Data (1)
Send/Receive serial data from the Motor Controller.
2. Clock Signal (1)
Sync signal used in conjunction with Serial Data.
6.0. Button Operation
6.1 Up/Down Button
This button shall send a door operation command to the MCU. The operation command shall toggle the current door movement(stop/run).
6.2 Light Button
This button shall turn the MCU light on.
6.3 Lock Button
This button shall prevent any door action.
6.4 Sound Button
This button shall turn the MCU sound device off.
7.0 OCU Software
The preferred OCU software described in this section will be loaded into, for example, a MicroChip #PIC16C55 device. This device has 512(×12) bytes of user program memory.
7.1 Program Routines
Main
Purpose
1.
Init
load/set all program operating parameters
2.
Main Loop
program flow control
3.
Listen
used to take data from MCU
4.
Talk
used to send data to MCU
5.
Display
used to translate rec'd data to LED
SubRoutines
Purpose
1.
Time delays
controls time delays within routines
2.
Com Init
prepares data for console
IV Remote Operational Control Unit, Keypad (ROCU)
1.0 The RF Linked Operational Control (FIG. 5) Unit shall allow an operator to send commands to the Motor Control Units (MCU).
2.0 Software Operating Requirements
A “PIC” micro controller shall perform the interfacing between an 12 button keypad, a LED device and a data transmitting circuit needed to send keypad information to the Door Motor Controller.
2.1 The Following specifications may apply:
2.1.1 The Keypad micro controller shall contain all the software needed to emulate the operation of a HCS201 encoder device. (Provided by the MicroChip Corp.)
2.1.2 The Keypad micro controller shall also contain a Serial # code and a Manufacture's ID code used for secure transmitter/receiver link operation.
2.1.3 The Keypad micro controller shall contain non-volatile memory. All operational access codes shall be retained on power down.
2.1.4 The Keypad micro controller shall self activates into a “Sleep” mode (refer section 5.0) after 10 seconds of keypad inactivity (only after initial access code programming is complete, refer section 6.0). The micro controller shall return to a “Wake” mode by the operation of the keypad door switch and shall be indicated by an active LED device.
2.1.5 A blinking LED device shall indicate a Keypad micro controller without any valid access code programming. A constant on LED device shall indicate a Keypad micro controller with a valid access code.
3.0 Hardware Configuration
1.) A “PIC” micro controller
2.) Keypad switches
3.) Panel Light
4.0. I/O configuration
TABLE 4.1
Inputs (qty)
Purpose
1. Row switches (4)
Used to determine depressed switch identity.
TABLE 4.2
Outputs (qty)
Purpose
1. Column signal (4)
Used in conjunction with Row switches.
2. Operational Light (1)
Used to indicate keypad status.
3. Serial Data (1)
Send/Receive serial data from the “HCS201”
encoder. (refer to section 9.0 for details)
4. Clock Signal (1)
Sync signal used in conjunction with Serial
Data.
5.0 Sleep/Wake Operation
The ROCU shall operate in two (2) modes.
5.1 Mode 1 shall be defined as “sleep”. The ROCU should draw minimum current and should not respond to any keypress operation. Mode 1 shall only be activated after a period of no keypress activity for 10 seconds regardless of the ROCU panel door position.
5.2 Mode 2 shall be activated with the operation of the ROCU panel door. Mode 2 shall be defined as “wake”. The Rocu shall operate at normal current draw and shall respond to any/all keypress operations.
6.0 Code Programing
The ROCU usually requires an initialization routine for proper operation.
This routine comprises the entry of a “owner/operator” password which is stored in non-volatile memory.
A password is preferably defined as a set of one(1) to a maximum of eight (8) numeric digits entered consecutively followed by the depression of the “light” key.
7.0 Button(Keys) Operation & Lights Keys
7.1 “Light” key:
This key will initiate a “turn light on” command to the MCU if depressed prior to any other key.
This key will terminate a password code programming sequence if depressed as the final key in the sequence.
7.2 Numeric (0-9) Keys
These keys are used to enter the password code.
7.3 The “R” and “L” Keys
This key shall initial a “door movement command” if depressed following the depression of a set of numeric keys*. (*Note: The set of numeric keys depressed must match a store set of numeric keys held in memory.)
8.0 ROCU Software (Keypad)
The ROCU software described in this section will be loaded into a MicroChip #PIC16F84 device. This device has 2K(×12) bytes of user program memory. A Memory Map details the location of the program within this memory space.
8.1 Program Routines
Main
Purpose
1.
Init
load/set all program operating parameters
2.
Main Loop
program flow control
3.
Keypress
used to translate keypress to ROCU commands
4.
Talk
used to send data to HSC200
5.
Save
used to save password info to memory
6.
Retrieve
used to retrieve password info from memory
SubRoutines
Purpose
1.
Time delays
controls time delays within routines
2.
Validation
handles password validation
VI. MCU Software Operation (FIG. 6)
The Motor Control Unit (MCU) operational program is comprised of one main executive loop routine which controls the operations of the GDO system by handing off various control task to numerous specialized routines.
The following table is the processor input/output (IO) pin reference.
Input
Active
Attention Request
Pin#
Level (note 1)
Purpose
Condition
10
LO
Program Button
depressed
11
LO
Plus Button
depressed
12
LO
Minus Button
depressed
13
HI
Terminal Address Switch 1
open (note 2)
14
HI
Travel Limit Switch
open (door fully up)
15
LO
IR Detector Signal
obstruction detected
16
—
Speed Sensor Device
pulsing
17
HI
Terminal Address Switch 2
open (note 2)
Output
Default
Normal
Pin#
Level (note 3)
Purpose
Condition
18
LO
Motor Forward control
Off
19
LO
Motor Reverse control
Off
20
LO
Motor Speed control
(slow speed)
21
LO
Light Control
Off
22
LO
Sound Control
Off
23
LO
Brake Control
inactive
24
HI
HCS500 Device Reset
Disable
Bi-Directional
Default Condition
Pin#
& Level (note4)
Purpose
6
Output
LO
Wall Console Data communication bus
7
Input
Hi-Impedance
Wall Console Serial Clock bus
8
Input
Hi-Impedance
HCS500 Data communication bus
9
Output
LO
HCS500 device Serial Clock bus
(note 1: Level at which the input is requesting attention from the processor.)
(note 2: Factory set condition.)
(note 3: Level which will cause the Normal Condition.)
(note4: Level which is set at power up and maintained if no interaction is required.)
1.0 Initialization (FIG. 7)
At power up the micro controller should:
1. Clear all user memory and bring all Outputs to a low voltage state.
2. Read EEprom (Retrieve routine) and hold all values.
3. Check the “initialization” flag returned from the EEprom:
If set load all values retrieved from EEprom into the system working memory.
Or
If not set load all default operating values in the working memory
And active the sound device.
4. Read the Button switches:
If active reset all operating values in the working memory to the default setting
And active the sound device.
5. Set the following flags
1. light flash
2. send a clear the console message
3. door up
6. Clear the master clock.
7. Wait 100 ms for all the other peripheral to power up.
8. Turn the sound device off.
9. Proceed to Main Executive
2.0 Main Executive (FIG. 8)
The Main Exe routine will (in the following order):
1. Monitor the console data bus and
If an attention signal is present will check the master clock
If time allows will jump to the Console Receive Communication routine.
2. Monitor the RF data bus and
If an attention signal is present will check the master clock
If time allows will jump to the RF Communication routine.
3. Check the Console Transmit flag
If set check the motor status and
If the motor is off jump to the Console Send Communication routine.
4. Check the Motor and
If off jump to the Time/Overun routine.
5. Check the Master Clock and
If the master clock equals the Alarm setting jump to the Motor Monitor routine.
6. Check the Motor and
If off check the buttons and
If any are active jump to the Button routine.
7. Jump to the Light and Sound Service routine.
8. Check the Motor and
If off check the Write to EEprom flag and
If set jump to the EEprom Store routine.
9. Jump to the Reverse Motor routine.
10. Return to section 1.
3.0 Motor Monitor (FIG. 9)
This preferred routine determines the status of the Motor using the motor flags and
A. If OFF
1. Wait for the master clock to reach 64 ms and
1. reset the master clock (usclock) and reset the clock change flag
2. increment the secondary clock (msclock)
3. increment the sound counter
2. Check the Motor request flags and
If any are set jump to the Motor On routine.
B. If On
1. Jump to the Sense Pulse Edge Detection routine and
1. synchronize the master clock to the HI going speed sensor pulse edge.
2. perform all the function of section A.1 above
3. Store the current door speed
4. Adjust the door positional counter
2. Calculate the door speed tolerance window and
If out of tolerance perform the following:
1. turn off the motor power and clear the motor flags.
2. set the appropriate error flags
3. signal a console message using the transmit flag.
4. set flash light flag on.
5. turn on the sound device.
3. Determine if a motor speed change is required.
4. (Based on the door direction) check any/all the following:
1. the travel limit switch.
2. the Max travel vs. position value.
3. the IR detection status.
4. the pass limit switch counter.
5. the motor off request flag.
And If required by any of these conditions perform any/all of the following:
1. turn off the motor and clear the motor flags.
2. set the error and console transmit flags.
3. set the flash light flag.
4. set the sound device on.
4.0 Console (Send & Receive) Communication (FIG. 10)
These routines will either
A. Send data to the console unit
If a transmission is required the following will take place.
The data bus will be checked for availability and
If available
1. A clock bus attention signal will be trigger on the bus.
2. A 50 ms wait for a response will take place.
(If no response is received this routine is aborted)
3. When the response has been acknowledged
A data transfer will start and proceed to it's conclusion.
OR
B. Receive data from the console unit
If an attention signal is pending on the clcok bus the following will take place.
1. A attention response signal will be acknowledged on the data bus.
2. A master clock check will take place.
(If no transfer is started before an alarm is triggered this routine is aborted)
3. all data will be received.
4. a processing routine will decode and set/clear the appropriate flags.
5.0 EEprom Store/Retrieve (FIG. 11)
These routines will either
A. Store data to the EEprom (HCS500) unit.
If a EEprom write is required the following will take place.
1. A clcok bus attention signal will be trigger on the bus.
2. A 1.2 ms wait for a response will take place.
(If no response is received this routine is aborted)
3. When the response has been acknowledged
A data transfer will start and proceed to it's conclusion.
OR
B. Retrieve data from the EEprom (HCS500) unit.
If a EEprom read is required the following will take place.
1. A bus attention signal will be trigger on the bus.
2. A 1.2 ms wait for a response will take place.
(If no response is received this routine is aborted)
3. When the response has been acknowledged
A data transfer will start and proceed to it's conclusion.
6.0 RF (Remote) Communication (FIG. 12)
This routine will take data from the RF (HCS500) unit.
If an attention signal is pending on the data bus
AND
If the enable flag allows a data transfer the following will take place.
1. A attention response signal will be acknowledged on the clock bus.
2. A master clock check will take place.
(If no transfer is started before an alarm is triggered this routine is aborted)
3. all data will be received.
4. a processing routine will decode and set/clear the appropriate flags.
7.0 Button and Programming (FIG. 13)
This routine will monitor the status of the buttons and proceed as follows:
IF either of the “+” or “−” buttons are depressed the following will take place.
A timer will start to determine the length of the button hold down period.
IF the initialization flag allows and the length of hold down time is greater
then ½ seconds the following will take place.
1. power to the motor will be applied based on which button
(“+”=down, “−”=up) is depressed.
2. the button is monitor and the moment it's released, power is turned off.
(If the initialization flag is cleared this routine is aborted).
OR
IF the length of hold down time is less then ½ seconds the following will take place.
1. The maximum travel value will be adjusted 1 increment based on which button is depressed.
OR
IF the “program” button is depressed the following will take place.
1. A counter will determine the number of “program” button depressions and based on this number the following table will determine the “+” & “−” button mode functionality.
1st depression=Up force adjustment
2nd depression=Down force adjustment
3rd depression=Transmitter Link or Transmitter Un-Link
4th depression=Routine Exit
2. The “+” button will increment the adjustment OR perform a transmitter link.
3. The “−” button will decrement the adjustment OR perform a transmitter un-link.
8.0 Light and Sound (FIG. 14)
This routine will monitor the status of the system light and sound device using the corresponding flags and proceed as follows:
IF the light flag is set (light=on) the following will take place.
1. the master clock will be compared to the light timer and
If they match the light will be turned off.
IF the light flash flag is set the following will take place.
1. the master clock will be compared to the light timer and
If they match the light will be toggled to it's opposite state.
IF the sound flag is set the following will take place.
1. the master clock will be compared to the sound timer and
If they match the sound will be toggled to it's opposite state.
9.0 Reverse Motor (FIG. 14)
This routine will determine if the motor status needs to be changed and proceed as follows:
IF the reverse flag is set the following will take place.
1. the master clock is monitored to determined a 2 sec elapses time and
2. after 1 seconds the motor on flag is set.
10.0 Time/Overrun (FIG. 14)
This routine will determine if a motor on request flag is set and
IF set will check the number of door operations performed within the pervious allowable time period and if under limit, increase the door operational count.
IF the operational count is over limit, will clear the motor request flag and will start the cool down timer.
IF the motor request flag is clear, will exit this routine.
VII. OCU Software Operation (FIG. 15)
The Operational Control Unit (OCU) operational program is comprised of one main executive loop routine which controls the operations of the wall console by handing off various control task to numerous specialized routines.
The following table is the processor input/output (IO) pin reference.
Input
Active
Attention Request
Pin#
Level (note 1)
Purpose
Condition
10
LO
Door On/Off Button
depressed
11
LO
Lock/UnLock Button
depressed
12
LO
Sound OFF Button
depressed
13
LO
Light On/Off Button
depressed
16
LO
Motion Detector
motion detected
17
HI
Terminal Address Switch
open (note 2)
Output
Default
Normal
Pin#
Level (note 3)
Purpose
Condition
18
LO
Lock indicator
Off
20
LO
Safety indicator
Off
23
LO
LoBattery Condition
Off
Bi-Directional
Default Condition
Pin#
& Level (note4)
Purpose
6
Output
LO
Motor Control Data communication bus
7
Input
Hi-Impedance
Motor Control Serial Clock bus
(note 1: Level at which the input is requesting attention from the processor.)
(note 2: Factory set condition.)
(note 3: Level which will cause the Normal Condition.)
(note4: Level which is set at power up and maintained if no interaction is required.)
1.0 Initialization (FIG. 16)
At power up the console will:
1. Clear all user memory and bring all Outputs to a lo voltage state.
2. Turn on the “Safety” indicator
3. Clear the master clock.
4. Proceed to Main Executive
2.0 Main Executive (FIG. 17)
The Main Exe routine will (in the following order):
1. Check the master clock and
If a time-out condition has occurred will jump to Process Clock
2. Monitor the Button (FIG. 18) status and
If depressed will check the switch enable flag and if allowed will
1. wait 12 ms for switch debounce
2. recheck the button status and if still depressed
3. call the Talk routine to send the button command to the MCU
4. clear the switch enable flag.
Or if not active set the switch enable flag
3. Check the LED flag and if set will call the Display routine.
4. Monitor the Motor Control Serial Clock bus status and
If HI will jump to the Listen routine
5. Monitor the Accessory (FIG. 19) Motion status and
If attention is requested will check the 4 minute enable flag and if allowed will
1. wait 10 ms for signal debounce
2. recheck the Motion status and if still active
3. call the Talk routine to send the accessory command to the MCU
4. clear the clear enable flag
Or if not active set the accessory enable flag
6. Return to section 1.
3.0 Communication (Talk, Listen) (FIG. 20)
These routines will either
A. send (Talk) data to the motor control unit
If a transmission is required the following will take place.
The data bus will be checked for availability and
If available
1. A attention signal will be trigger on the clock bus.
2. A 200 ms wait for a response will take place.
(If no response is received this routine is aborted)
3. When a response has been acknowledged on the data bus
A data transfer will start and proceed to it's conclusion.
OR
B. receive (Listen) data from the motor control unit
If an attention signal is pending on the clock bus the following will take place.
1. A attention response signal will be acknowledged on the data bus.
2. A 200 ms wait for a response will take place.
(If no transfer is started this routine is aborted)
3. all data will be received.
4. the LED display flag will be set.
4.0 Process Clock (FIG. 21)
The Clock Process routine will:
1. Reset the master clock and increment the secondary clock.
2. Check if the secondary clock equals a present limit and if it is will:
1. reset the secondary clock and increment the third clock.
2. check if the third clock equals a present limit and if it is will:
1. reset the third clock and reset 4 minute flag.
5.0 Display (FIG. 22)
If the LED flag is set this routine will apply all stored received motor data to the indicator Output and clear the LED flag.
VIII. ROCU Software Operation (FIG. 23)
The Remote Operational Control Unit (ROCU) operational program is comprised of one main executive loop routine which controls the operations of the keypad by handing off various control task to numerous specialized routines.
The following table is the processor input/output (IO) pin reference.
Output
Default
Normal
Pin#
Level (note 1)
Purpose
Condition
3
HI
Master clear enable
disabled
6
LO
RF data signal 0
Off
7
LO
RF data signal 1
Off
8
LO
RF data signal 2
Off
9
HI
Panel Indicator Light
On
10
HI
“Light” button
Column 0 write
11
HI
“3”,“6”,“9”,“R” button
Column 1 write
12
HI
“2”,“5”,“8”,“0” button
Column 2 write
13
HI
“1”,“4”,“7”,“L” button
Column 3 write
Input
Active
Attention Request
Pin#
Level (note 2)
Purpose
Condition
17
HI
“R”,“0”,“L”
Row 0 read
18
HI
“9”,“8”,“7”
Row 1 read
1
HI
“6”,“5”,”4”
Row 2 read
2
HI
“Light”,“3”,“2”,“1”
Row 3 read
Keypad Matrix Value
Stored
Level@
Level@
Hex
Column#
Row#
Value
3 2 1 0
3 2 1 0
IF Key Depressed
18
0 0 0 1
0 0 0 1
light (this key not stored)
21
0 0 1 0
0 0 0 1
R (this key not stored)
22
0 0 1 0
0 0 1 0
9
24
0 0 1 0
0 1 0 0
6
28
0 0 1 0
1 0 0 0
3
41
0 1 0 0
0 0 0 1
0
42
0 1 0 0
0 0 1 0
8
44
0 1 0 0
0 1 0 0
5
48
0 1 0 0
1 0 0 0
2
81
1 0 0 0
0 0 0 1
L (this key not stored)
82
1 0 0 0
0 0 1 0
7
84
1 0 0 0
0 1 0 0
4
88
1 0 0 0
1 0 0 0
1
(note 1: Level which will cause the Normal Condition.)
(note 2: Level at which the input is requesting attention from the processor.)
The Power up bit is read and either routine A or B is performed.
A. At POWER UP the keypad will:
1. Configure the IO port.
2. Clear all user memory and bring all Outputs to a lo voltage state.
3. Call the Retrieve routine, read the permanent memory & load ram
4. Set the panel light (refer to as the “indicator”) to Blinking mode.
5. Clear the master clock.
6. Proceed to Main Executive
B. At WAKE UP (note 1) the keypad will:
1. Configure the IO port.
2. Clear all user memory and bring all Outputs to a lo voltage state.
3. Set the panel light (refer to as the “indicator”) as determined by the Indicator flags.
4. Clear the master clock.
5. Proceed to Main Executive
NOTE 1: The keypad is programmed to execute a SLEEP mode of operation where as all ram memory is retained. “WAKE UP” is a return from this SLEEP mode.
2.0 Main Executive (FIG. 25)
The Main Exe routine will (in the following order):
1 . Active a Column 0 write and Monitor the “Light” button and if active call the LightSw_ck routine and then perform one of the following depending on the program flags value returned:
0=Call the Send Operate Light command.
1=Store all keypad digit entries and set the program flag to 2.
2=Jump to the Program routine.
2. Active a Column 1,2,3 write and Monitor the Numeric Digit and the “R”/“L” buttons and if active perform one of the following depending on the button depressed:
“R”/“L” jump to the Digit _plus routine.
Numeric Digit=jump to the Digit routine.
3. Check the master clock and if the clock equals a pre-determined value jump to the Clock routine.
4. Check the Sleep timer and if the timer equals a pre-determined value jump to the Bedtime routine.
5. Return to section 1.
3.0 Program (FIG. 26)
The Program routine will perform one operation as described in the table below depending on the status of the following flags:
Init=0
Code=1 set the code flag=2 & set the indicator flag=off.
Code=2 compare the 2 sets of digit entries and
If they match STORE the entry as a primary passcode. Clear all program flags and re-adjust the indicator flag.
If they do not match clear entries and all flags.
Init=1
Code=1 call the Validation routine to validate the first digit entry and
If valid set/clear the PS flag depending on weather the entry is a primary passcode.
If not valid clear entries and all flags.
Code=2 check the PS flag and proceed as follows:
PS=prim: call the Validation routine to validate the second digit entry
and
If valid primary passcode, REMOVE All stored passcode entries and clear all program flags and re-adjust the indicator flag.
If not primary passcode, STORE ADDITION entry as a passcode.
PS=sec/ov: call the Validation routine to validate the second digit entry
and
If valid passcode, REMOVE ADDITION entry from memory.
If not valid passcode, clear entries and all flags.
4.0 Digit_plus and Digit
The Digit routine will check the digit counter and if not at max will store the entered digit and increment the digit counter.
The Digit_plus routine will perform as described below depending the button depressed.
If the button depressed was a non-digit, this routine will jump to the Digit routine.
If the button depressed was either “R” or “L” then a the digit entry will be check for Validation and
If valid a SEND Operate Door 1 or 2 command will be called depending on which button was depressed.
If not valid will clear all entries, counters and flags.
5.0 LightSw_ck
This routine will monitor the length of time the light button is depressed.
If the button is depressed for more then 5 seconds the program flag is set to 1.
6.0 EE Memory (FIG. 27)
Retrieve
This routine will perform as follows:
1. Set the data to read counter to 25
8 digits times 3 words (passcodes), plus 1 data valid bit.
2. Adjust the memory pointers.
3. Read and transfer all the data to system ram.
4. Check the data valid bit and
If valid, set the Init flag and retain the data in system ram.
If not valid clear the Init flag.
Store
This routine will perform as follows:
1. Determine first open available memory location and set the memory pointer.
2. Set the data to write counter to 8 (8 digits passcodes).
3. Transfer all the data to permanent memory.
4. Write a valid data bit to permanent memory.
7.0 Bedtime (Sleep/Wake)
This routine will prepare the system for low power (Sleep) mode of operation by:
1. Turning off the indicator panel light.
2. Clearing all the program flags.
3. Clearing all the timers and counters.
4. Enabling the master reset output pin which allows a panel door circuit to Wake the system after receiving a trigger signal on the master clear input pin.
5. Execute a Sleep system command.
8.0 Clock (FIG. 28)
This routine will proceed as follows:
1. Reset the master clock and
2. Depending on the status of the indicator flag:
1=toggle panel light from either on to off OR off to on.
2=turn panel light off
3=turn panel light on
9.0 Validation
This routine will proceed as follows:
1. Reset all memory pointers to zero.
2. Set the word checking counter to 3.
3. Compare each digit ( 8 ) entered to the passcode digits stored in ram memory.
If a match is found the corresponding word value is set as a return value
And the routine exits.
4. If no match is found the word counter is advanced and the procedure repeats.
If no match is found after the third word compare, the return flag value is set to zero.
And the routine exits.
10.0 Send Routine (FIG. 29)
This routine will active the RF circuit as follows depending on which command is triggered by the calling routine. Refer to the following table.
RF Data Signal Reference Table
Level@
RF Data
Signal#
Value
2 1 0
Send Command
0
0 0 0
no data transmission
1
0 0 1
operate door 1
2
0 1 0
operate door 2
3
0 1 1
operate light
4
1 0 0
not valid
5
1 0 1
operate door 1 w/ lock override
6
1 1 0
operate door 2 w/ lock override
7
1 1 1
not valid | An improved garage door opener is disclosed. The garage door opener has a motor drive unit for opening and closing a garage door. The motor drive unit has a microcontroller. Connected to the motor drive unit is a wall console that resides inside the garage. The wall console also has a microcontroller. The microcontroller of the motor drive unit is connected to the microcontroller of the wall console by means of a digital data bus. | 4 |
BACKGROUND OF THE INVENTION
[0001] The invention generally relates to systems and methods for controlling the infusion of medical fluids and, more particularly, to a fluid flow restrictor placed in an infusion line to achieve a more uniform rate of flow through that line while reducing the possibility of contaminants being conducted.
[0002] Infusion of fluids is one of the most widespread procedures in medicine. Infusion systems deliver liquid therapeutic substances (e.g. drugs in solution, saline, nutrients) to patients typically through veins and arteries, but also into interstitial spaces as well. Every infusion is driven by some source of pressure. Two common sources of fluid pressure for causing the infusion of medical fluids into a patient are gravity and positive pressure infusion pumps. The medical fluids are typically delivered through sterile, single-use, disposable fluid administration sets that comprise tubing and a cannula or catheter and perhaps an administration port or ports along the tubing for the infusion of additional medical fluids.
[0003] Infusion systems operating by gravity typically use a container of the medical infusion fluid suspended above the patient. In gravity infusion the pressure for infusing the medical fluid is produced by the very weight of the medical fluid itself. In practice, this is effected by suspending the container higher than the patient. Then the pressure of the fluid produced by gravity is high enough to overcome the counter pressure of the patient's circulatory system and thus allows for infusion of the medical fluid into the patient. In such a system, the magnitude of the pressure depends on the height of the container. However, as the fluid level in the container decreases, the pressure decreases and the rate of flow decreases. A varying rate of flow is undesirable for some medications as it has been found that a uniform flow rate of medical fluid has a more predictable treatment effect on the patient.
[0004] Furthermore, the requirement that the container of medical fluid must be suspended above the patient in a gravity system has made such systems impractical for use with ambulatory patients. Many surgical procedures today may be completed on an “out patient” basis. In many cases, the surgical procedure can be completed in less than a few hours and the patient may leave the health care facility in an “ambulatory” state. Yet the infusion of medical fluid after completion of the procedure is necessary for the patient's well being. The same is true for patients who have been released after extended stays at health care facilities. The continued infusion of medical fluids may be necessary for them. Whether that medical fluid is pain medication, nerve block (anesthetic), chemotherapy, or other, the continued infusion of that fluid into the patient may be necessary.
[0005] Because of this more and more common situation of an ambulatory patient with a continuing need for infusion, ambulatory infusion pumps have been developed. Such pumps can be carried by the patient at a position lower than the patient's heart, such as on the patient's belt because they use a positive pressure source. The pressure source of these pumps is strong enough to force the infusion fluid into the patient regardless of the location of the pump in relation to the patient's heart. However, such ambulatory infusion pumps must be relatively inexpensive since they are personal in nature and it is desirable that they be disposable by the patients after the treatment has been completed. Because of this need to create a lower cost and disposable ambulatory pump, many do not produce flow rates that have the desired level of uniformity.
[0006] In most cases, the mechanism used to apply pressure to the medical fluid to achieve infusion is not linear across its entire range of operation. In many cases, the amount of pressure exerted on the medical fluid when the pump is full differs from the amount of pressure when the pump is almost empty. Without further intervention, the flow rate will be correspondingly variable and non-uniform. Thus some manufacturers include fluid flow restrictors in the fluid line leading to the patient. Such flow restrictors “restrict” the flow rate of medical fluid to the patient to a level that will achieve the desired therapeutic effect. Cost considerations require that such flow restrictors be produced at low cost, yet be as accurate as possible.
[0007] To achieve the advantages of a portable ambulatory pump, several types of mechanisms have been suggested. Because of the needs to control cost and limit complexity, and to function for an ambulatory patent, a mechanical power source has proven to be more desirable.
[0008] Of the numerous mechanical structures that have been used as a pumping chamber in portable infusion pumps, one structure is of particular interest. This structure comprises an elastomeric membrane that is stretched beyond its at-rest configuration by the loading of medical fluid into it. The membrane's tendency to return to the contracted configuration provides the necessary mechanical power to move fluid through a tube to a patient. As the membrane tends to return to its at-rest configuration, the medical fluid within it is expelled out of the membrane, through the administration set, and into the patient. An elastomeric pumping mechanism has several features which make it attractive for such an application. Firstly, an elastomeric structure is relatively inexpensive to manufacture. Secondly, it has an operational simplicity that enhances its appeal for use in devices which are to be operated by lay persons.
[0009] However, an elastomeric membrane does not address the problem encountered at the end of a pumping cycle that is caused by the inability of an elastomeric membrane to maintain a constant pressure within the fluid chamber as the membrane approaches its unstretched state. With some, the membrane snaps back to its at-rest configuration as it nears that state. This results in a period of non-uniformity in the flow rate. As is well known, constant pressure within the pumping chamber during a pumping operation from beginning to end is very much desired to obtain a uniform dispensing rate.
[0010] One portable pump that takes these features into account is the ReadyMED pump made and distributed by the ALARIS Products division of Cardinal Health, San Diego, Calif. It includes a housing that stretches an elastomeric membrane into its region of nonlinear elasticity. To do this, the housing is formed with a surface that has a predetermined contour that is circumscribed by a periphery. The elastomeric membrane is then attached to this periphery to position the membrane over and across the contoured surface of the housing. This stretches the membrane into its region of nonlinear elasticity, and creates a fluid chamber between the surface of the housing and the elastomeric membrane. When the fluid chamber is filled with medical fluid, the stretched membrane generates a substantially uniform pressure on the fluid within the chamber for a uniform discharge of the fluid from the chamber.
[0011] There are several types of flow restrictors available. One example is a tube clamp that may be set by the nurse to pinch the infusion tubing partially closed to achieve a desired flow rate. Although these are simple devices and relatively inexpensive, most tubing will react to the continued application of pressure from a pinch clamp and the flow rate will vary. A more precise means of restricting the flow is desired.
[0012] Another device used as a flow restrictor is a capillary tube. With the principal flow restrictor comprising a capillary element, the extent to which the restrictor limits the fluid flow rate is determined by the length and cross-sectional area of the capillary element itself. These dimensions are selected based on the input pressure from the pressure source to deliver the liquid medicament at a predetermined flow rate. If the capillary element is to be maintained within the housing, it becomes difficult to substantially lengthen the capillary element without requiring a re-design of the housing. To avoid such a re-design, the internal diameter of the capillary element may be varied; however, with the small internal diameters utilized in the flow restrictor, such as a capillary of about 0.041 mm (0.0016 inch) in diameter, it becomes difficult to consistently manufacture capillary elements having the required precise internal diameter. It should be noted that variances in diameter can average out over the length of the capillary element but as noted above, the length of the element is limited when it is disposed within the housing, thereby limiting the extent to which the effect of variances along the length of the capillary element can be minimized.
[0013] Flow rates such as about 48 milliliters (“ml”) in twenty-four hours or even slower flow rates are desirable in certain circumstances. As an example only, it is sometimes desirable to deliver 36 ml, 48 ml, or 60 ml of a medical liquid in three, four, or five days.
[0014] A further limitation with present infusion capillary tube systems is that because of the diameter involved, capillary tube fluid flow restrictors can become easily clogged. If an infusion line becomes clogged, fluid flow will slow or stop. Such a stoppage in treatment is undesirable for a patient who may depend on the medication for pain relief or for other reasons.
[0015] Currently, some pumps having elastomeric drive devices use glass capillary tubes with a very small inside diameter and a macroscopic outside diameter. This type of tube has several drawbacks associated with its use. It is difficult to obtain an adequate seal with the outside diameter of the glass because of the smooth nature of glass. Due to the cleaving operation by which the glass is cut, the outside edges of the outside diameter are sharp and can create particulate matter that may enter the fluid flow stream. This particulate can occlude the inside of the capillary, especially when the glass capillary is inserted into a fitting or a flexible sleeve. This problem has been resolved in the past by roughing or flame polishing the edges of the glass but which could again result in particulate that can occlude the capillary or which can create additional labor steps. Finally, since the cut edge of the glass capillary and the exit hole are on the same plane, these restrictors are also more likely to become clogged by particulate which comes to rest on this cut edge in close proximity to the exit hole. Thus, it is advantageous to have a fluid flow restrictor that is capable of reducing the flow rate while being less prone to clogging.
[0016] Hence those skilled in the art have recognized a need for a fluid flow restrictor that is less prone to clogging. Yet a further identified need is for a flow restrictor that can be manufactured more cost effectively and can use interchangeable parts with restrictors of differing sizes. The invention fulfills these needs and others.
SUMMARY OF THE INVENTION
[0017] In accordance with aspects of the invention, there is provided a fluid flow restrictor having a capillary tube to restrict the flow to a desired rate. In accordance with some aspects of the invention, a chamber is provided that separates contaminants from the flow of medical fluid from a reservoir before they reach the capillary tube.
[0018] In one aspect, there is provided a fluid flow restrictor for regulating the flow rate of fluid through a fluid supply tube. The supply tube comprises a distal end and an internal fluid passageway with a supply tube inner cross-section, the restrictor comprising a chamber having a distal end and a proximal end, the proximal end of which is in fluid communication with the distal end of the supply tube wherein fluid from the supply tube flows into the chamber through the proximal end of the chamber. The chamber may be configured with an inner chamber cross-section that is same or larger than the supply tube inner cross-section, and a capillary tube having a capillary tube inner cross-section that is smaller than the supply tube inner cross-section and smaller than the chamber inner cross-section. The capillary tube is preferably configured with a proximal end extending into the chamber at a desired length from the distal end of the chamber, wherein the length and the capillary tube inner cross-section are selected to result in a desired flow rate. The relative smallness of the inner cross-section of the capillary tube as compared to the inner cross-sections of the chamber and the supply tube results in filtering of contaminants into the chamber. In addition, the chamber volume resulting from the selected length of the chamber and the selected chamber inner cross-section slows the instantaneous velocity of the fluid from the supply tube so that contaminants will fall out of solution of the fluid and into the chamber.
[0019] In other more detailed aspects, the flow capillary tube is surrounded by a sleeve over less than the entire length of the capillary tube, wherein the sleeve mounts the tube such that the proximal end of the tube projects into the chamber. The fluid flow restrictor further comprises a housing surrounding the sleeve and interconnecting with the distal end of the fluid supply tube forming the chamber between the distal end of the fluid supply tube and the sleeve wherein all flow through the chamber must proceed through the capillary tube.
[0020] In additional more detailed aspects, the restrictor tube has a distal end that is in fluid communication with a distal segment of tube that conducts fluid flowing through the restrictor tube to a downstream location at the flow rate controlled by the capillary tube. The capillary tube is surrounded by a sleeve over less than the entire length of the capillary tube, wherein the sleeve mounts the capillary tube such that the proximal end of the capillary tube projects into the chamber. The sleeve may include a radially-outwardly extending mounting flange. The restrictor tube further comprises a first housing surrounding the sleeve and interconnecting with the distal end of the fluid supply tube forming the chamber between the distal end of the fluid supply tube and the sleeve, a second housing surrounding the sleeve and interconnecting with a downstream segment of the fluid supply tube into which the capillary tube feeds fluid. The first and second housings are mounted over the sleeve and may be configured to abut each other or the optional mounting flange.
[0021] In other aspects in accordance with the invention, there is provided an infusion system comprising a pump, a supply tube segment in fluid communication with the pump to conduct fluid from the pump, the supply tube segment having a distal end and a supply tube inner diameter, and a capillary flow restrictor in fluid communication with the distal end of the supply tube segment for receiving fluid from the pump and controlling the flow rate of that fluid, the capillary flow restrictor comprising a housing connected with the supply tube segment for receiving fluid from the pump, the housing having a proximal end, a sleeve disposed within the housing and having a proximal end, the sleeve disposed so that the proximal end of the sleeve is displaced from the proximal end of the housing, thereby forming a chamber having an inner chamber cross-section. The capillary flow restrictor further comprises a capillary tube mounted partially within the sleeve, the capillary tube having an inner cross-section smaller than the chamber inner cross-section and having a length, the capillary tube inner cross-section and length selected to provide a desired flow rate through the capillary tube, the capillary tube having a proximal segment extending outwardly from the sleeve and projecting into the chamber, the inner cross-section of the chamber selected to be larger than or equal to the inner cross-section of the fluid supply tube so that the chamber volume resulting from the selected length of the chamber and the selected chamber inner cross-section slows the instantaneous velocity of the fluid received from the supply tube so that contaminants will fall out of solution of the fluid and into the chamber, whereby such separated contaminants will not be conducted by the capillary tube.
[0022] Other detailed aspects include the flow restrictor comprises a capillary tube surrounded by a sleeve over less than the entire length of the capillary tube, wherein the sleeve mounts the capillary tube such that the proximal end of the capillary tube projects into the chamber, the sleeve having a radially-outwardly extending mounting flange, a first housing surrounding the sleeve and interconnecting with the distal end of the fluid supply tube forming the chamber between the distal end of the fluid supply tube and the sleeve wherein all flow through the chamber must proceed through the restrictor tube, a second housing surrounding the sleeve and interconnecting with a downstream segment of the fluid supply tube into which the capillary tube feeds fluid, and the first and second housings mounted over the sleeve and abutting the mounting flange.
[0023] Other detailed aspects include the flow restrictor having the capillary tube molded into a solid member over less than the entire length of the capillary tube, wherein the solid member mounts the capillary tube such that the proximal end of the capillary tube projects into the chamber. The flow restrictor further comprises a first housing surrounding a portion of the solid member and interconnecting with the distal end of the fluid supply tube forming the chamber between the distal end of the fluid supply tube and the solid member; a second housing surrounding the solid member and interconnecting with a downstream segment of the fluid supply tube into which the capillary tube feeds fluid. the first and second housings mounted over the solid member and abutting each other.
[0024] In accordance with method aspects of the invention, there is provided a method for restricting the flow of medicament through a fluid supply tube comprising pumping medicament into the fluid supply tube at a first instantaneous velocity, slowing the velocity of medicament through the fluid supply tube at a point downstream to a second instantaneous velocity that is less than the first such that contaminants in the medicament fall out of solution and are separated from the liquid of the medicament, and conducting the liquid of the medicament from the point where the contaminants are separated preventing the contaminants from further downstream flow.
[0025] These and other aspects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments which, taken in conjunction with the accompanying drawings, illustrate by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a view of a patient using an ambulatory pump mounted to his belt, the pump having a fluid administration set connected to it to conduct the medicament in the pump to the patient's elbow, the administration set including a fluid supply tube segment, a flow restrictor, an output tube segment, and a sharp cannula;
[0027] FIG. 2 is a view of the ambulatory pump system shown in FIG. 1 in which the pump is driven with an elastomeric membrane, conduits, a fluid flow restrictor, and a sharp cannula for delivering the medical fluid supplied by the pump to the patient;
[0028] FIG. 3 is a partial cross-sectional view of a fluid flow restrictor shown in accordance with aspects of the invention showing a capillary tube projecting into a fluid contaminants separation chamber;
[0029] FIG. 4 is a partial cross-sectional side view of the fluid flow restrictor of FIG. 3 showing the mounting configuration for the capillary tube and over-bonded sleeve;
[0030] FIG. 5 is a partial cross-sectional side view of another embodiment of the flow restrictor of the present invention showing the capillary tube, mounting sleeve, and housing coupled to fluid conduits or tubes in which the capillary tube extends beyond the mounting sleeve, for conducting medicament to the patient;
[0031] FIG. 6 is a partial cross-sectional side view of yet another embodiment of the flow restrictor of the present invention showing the capillary tube, mounting sleeve, and housing coupled to fluid conduits or tubes in which the capillary tube extends beyond the mounting sleeve, for conducting medicament to the patient; and
[0032] FIG. 7 provides a cross-sectional view of part of the diagram of FIG. 6 showing the capillary tube, contaminant separation chamber, and conduit walls.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring now to the drawings in more detail in which like reference numerals refer to like or corresponding devices among the views, there is shown in FIGS. 1 and 2 a view of an embodiment of an infusion system 20 having a pump 22 , a medicament supply tube segment or pump-side tube segment 24 from the pump, a fluid flow rate restrictor 26 , a patient delivery tube segment or patient-side tube segment 28 , and a sharp cannula 30 for inserting into the patient to perform the infusion. In FIG. 1 , it will be noted that the restrictor has been affixed to the patient 32 with tape 34 to stabilize the position of the cannula and control the temperature of fluid entering the restrictor assembly. This approach is meant to provide a broad illustration only and not meant to be restrictive of the use of the invention. Other techniques well known to those skilled in the art for mounting pumps to or with a patient, puncturing the patient, and stabilizing a tube, restrictor, or other devices may be employed as needed. Additionally, the size of the restrictor 26 has been exaggerated in this case for clarity of illustration.
[0034] The fluid infusion system 20 can be used for a wide variety of therapies such as pain, spasticity, cancer, and other medical conditions. The fluid infusion system 20 operates to infuse a therapeutic substance at a pre-determined rate into the patient 32 . The therapeutic substance is a product or substance intended to have a therapeutic effect such as pharmaceutical compositions, genetic materials, biologics, and other substances. Pharmaceutical compositions are chemical formulations intended to have a therapeutic effect such as intrathecal antispasmodics, pain medications, chemotherapeutic agents, and the like. Pharmaceutical compositions are often configured to function in an implanted environment with characteristics such as stability at body temperature to retain therapeutic qualities, concentration to reduce the frequency of replenishment, and the like. Genetic materials are substances intended to have a direct or indirect genetic therapeutic effect such as genetic vectors, genetic regulator elements, genetic structural elements, DNA, and the like. Biologics are substances that are living matter or derived from living matter intended to have a therapeutic effect such as stem cells, platelets, hormones, biologically produced chemicals, and the like. Other substances are substances intended to have a therapeutic effect yet are not easily classified such as saline solution, fluoroscopy agents, and the like.
[0035] Referring now to FIG. 3 , an embodiment of a fluid flow rate restrictor 26 in accordance with aspects of the invention is provided. The pump-side tube segment 24 is shown facing a capillary tube 40 that forms a part of the restrictor 26 . The pump-side tube segment includes a lumen opening 36 having a certain size (i.e. dimension) D 1 . Fluid from the pump 22 will be received from the lumen opening of the pump-side tube segment 24 into a chamber 42 . The chamber is formed by the pump-side tube segment 24 at the proximal end, and the distal end of the chamber is formed by the proximal end 44 of a sleeve 46 that surrounds and mounts the capillary tube 40 . The outer wall of the chamber is provided by a housing 48 that tightly fits over the fluid supply tube segment 24 and the sleeve 46 of capillary tube 40 in a fluid-tight fashion. As will be described in more detail below, the chamber has a volume selected to cause medicament entering the chamber 42 from the pump through the pump-side tube segment 24 to decrease in instantaneous velocity to a level where contaminants in the medicament fall out of the solution of the medicament thereby separating from the medicament. Those contaminants may then fall to the wall 48 provided by the housing. Because the capillary tube projects into the chamber by a certain distance and is not flush with the proximal end 44 of the sleeve 46 , it is much less likely that those separated contaminants will find their way into the capillary tube opening. In this way, the chamber performs a filtering function. In addition, the capillary tube may be eccentrically or oddly shaped to further precipitate filtering of contaminants.
[0036] Turning now to FIG. 4 , a partial cross-sectional side view of the restrictor of FIG. 3 is shown. The fluid supply tube segment 24 has a distal end 25 that forms a part of the chamber 42 . As can perhaps more clearly be seen in FIG. 4 , the contaminant-separating chamber 42 is formed by that distal end 25 of the fluid supply tube segment, the proximal end 44 of the capillary tube mounting sleeve 46 , and the housing 48 A. As illustrated, capillary tube 40 is preferably projected into the chamber to further aid filtering of contaminants. Also illustrated in FIG. 4 , the patient-side tube 28 is connected to the restrictor 26 by the housing 48 B. The housing consists of two parts, section 48 A on the proximal end 50 of the restrictor, and section 48 B on the distal end 52 .
[0037] The sleeve 46 around the capillary tube 40 may be formed of polyvinylchloride (PVC). The capillary tube 40 is slid into the sleeve and located as desired. Adhesive may be applied at one end of the sleeve at the capillary and will wick into the interface of the sleeve and capillary tube to permanently attach the sleeve to the capillary tube. In a preferred embodiment the capillary tube 40 is disposed within the sleeve 46 by adhesive bonding for example at its proximal end. Rigidity of the sleeve will protect the capillary tube from breakage due to extreme inadvertent bending.
[0038] As illustrated in FIG. 4 , an optional mounting flange 60 may be mounted on the sleeve 46 . The mounting flange may be centered on the sleeve and may also be formed of PVC. In one embodiment, the mounting flange is a shorter sleeve (e.g. 60 ) slid over the first sleeve (e.g. 46 ) and held in position by adhesive or other means. The mounting flange provides distal 62 and proximal 64 abutment surfaces for the housing 48 B, 48 A to facilitate manufacture and assembly of the restrictor 26 .
[0039] In one or more configurations (not shown), mounting flange 60 may be omitted. In such configurations, housing sections 48 A and 48 B may be configured such that the distal end of housing section 48 A and the proximal end of housing section 48 B are approximately abutting.
[0040] In a further embodiment, the sleeve 46 comprises a hard-plastic housing that is formed by being over-molded around the capillary tube 40 . The amount of overlap of the housing over the pump-side tube segment 24 and the patient-side tube segment 28 is not to scale in FIG. 4 and may actually be more than shown. Although not shown, the housing may have stop shoulders located internally to receive the pump-side tube segment and patient-side tube segment and limit their length of insertion into the housing.
[0041] Referring now to FIG. 5 , an alternate embodiment is shown in which the sleeve 70 of the capillary tube 40 differs from the embodiment of FIG. 4 . In this case, the sleeve may be formed by overmolding of PVC of another plastic material on the capillary tube and is configured to provide not only protection for the capillary tube and to provide proximal 72 and distal 74 mounting surfaces for the housing 48 , but also proximal 76 and distal 78 abutment surfaces for the housing. As in all the other configurations, the capillary tube may be configured to project out of the sleeve in both the proximal and distal directions. Also, flange 60 may be configured to extend outward to the distance similar to that of the housing outer surface to form a relatively smooth outer surface 66 . The patient will feel less discomfort with a smooth outer surface design than with other designs having an uneven outer surface.
[0042] Referring now to FIG. 6 , another alternate embodiment is shown in which the sleeve 80 of the capillary tube 40 differs from the previous embodiments. In this embodiment, the sleeve 80 may also be formed by overmolding of PVC or another plastic material on the capillary tube. The sleeve is configured to provide protection for the capillary tube and to provide proximal 82 and distal 84 mounting surfaces for the housing ( 48 A, 48 B). No abutment surfaces for the housing are provided and a gap may exist between the two housing components 48 A and 48 B. It should also be noted that this embodiment is configured such that the sleeve 80 has a length and location in relation to the capillary tube 40 so that both ends of the capillary tube project beyond the ends of the sleeve. This eliminates the possibility that the capillary tube could be improperly oriented when installed in the restrictor 26 . This will also reduce cost in the manufacturing process thus making it widely available to all patients with differing access to health care.
[0043] Turning now to FIG. 7 , further information on the relative sizes of the components of the chamber 42 is provided. Dimension D 1 is the inner surface dimension of the pump-side tube segment 24 . Dimension D 2 is the inner surface dimension of the housing which surrounds both the pump-side tube segment and the sleeve 46 that in turn surrounds the capillary tube 40 . Dimension D 3 is the inner surface dimension of the lumen 54 of the capillary tube 40 . D 2 is larger than D 1 which is larger than D 3 . The internal fluid passageway 90 of the pump-side tube segment with a first inner dimension D 1 is in fluid communication with a proximal end 92 of a chamber 42 . The chamber 42 has a length 94 and a chamber wall 96 . The chamber has a second inner dimension D 2 that is larger than the first inner dimension D 1 . A capillary tube 40 having a third inner dimension D 3 is provided. The capillary tube 40 is located at a distal end 98 of the chamber and has a length 100 projecting into the chamber. The third inner dimension D 3 is smaller than the first D 1 and the second D 2 inner dimensions. The inner dimensions D 1 , D 2 , D 3 along with the lengths 94 and 100 are selected to result in optimal filtering properties with minimal opportunity of damage to the capillary tube during manufacture or use.
[0044] As used herein, 1 “mil inch” shall be equal to 1/1000 of an inch and “mil-inches” shall indicate more than one mil-inch. Also, note that the flow restrictor, sleeve, and capillary may have circular cross-sectional areas thus, although their inner surface dimensions may be referred in terms of diameters, reference to diameters are not intended to limit the invention to circular/cylindrical objects.
[0045] Referring to the embodiments in FIGS. 4 through 7 , the sleeve (i.e. 46 , 70 , 80 ) can be injection molded around the capillary tube 40 . Alternatively, the sleeve (i.e. 46 , 70 , 80 ) can be co-extruded around the capillary tube during its manufacturing process.
[0046] Previous flow restrictors had the end of the capillary tube 40 flush with the end of the sleeve. In accordance with an aspect of the present invention, the capillary tube 40 projects outward from the sleeve and into the chamber 42 . In operation, fluid flows from the pump-side tube 24 at relatively high velocity and into the chamber 42 having a much larger volume. Once it reaches the chamber, the fluid velocity slows. Any contaminants being carried in the fluid will leave solution and settle to the bottom of the chamber 42 , away from the opening 102 to the capillary tube 40 .
[0047] The above-mentioned components of the restrictor 26 may be color coded to indicate the intended fluid flow rate of the restrictor. Such color coding provides a visual indication that the correct restrictor is assembled in the correct model.
[0048] The capillary tube 40 places a maximum limit on the flow rate of fluid out of the restrictor 26 . The capillary tube may be non-adjustable and thus pre-selected during manufacture to provide a given maximum fluid flow rate for fluid flowing out of the restrictor. In a preferred embodiment the capillary tube 40 is made of glass and defines a very small bore 102 in fluid communication with the chamber 42 .
[0049] With the flow regulator near the connecting means, the restrictor 26 can be placed on the patient's skin. The patient's body heat maintains the liquid passing through the capillary lumen 54 at a relatively constant temperature, regardless of changes in the ambient air temperature. When the infusion site is near the subclavian vein for example, the temperature is about 92 degrees F. (33.3 degrees C.). This relatively constant temperature provides a relatively constant liquid viscosity in the restrictor 26 and thus a more constant fluid flow rate through the bore 54 .
[0050] While several forms of the invention have been illustrated and described, it will also be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited except by the appended claims. | A fluid flow rate control system and method comprises a capillary tube having a proximal end that projects into a chamber with a cross-sectional area that is larger than or equal to the fluid supply tube's cross-sectional area. The inner cross-sectional area of the capillary tube is configured less than the inner cross-sectional area of the chamber. The chamber has a volume large enough to slow the fluid conducted to it by the upstream fluid line to permit contaminants to fall out of solution. In another aspect, a sleeve is used to mount the capillary tube into the chamber. The sleeve provides a mounting surface for tube segments from the pump and downstream of the capillary restrictor. | 0 |
[0001] This invention was made with Government support under contract number N00014-09-D-0821 awarded by the United States Navy. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to gas turbine engines, and in particular, to positioning movable vanes on gas turbine engines. In some gas turbine engines, movable vanes are used to adjust the angle of air flow into turbine and compressor sections. This is typically accomplished using an actuator to rotate the movable vanes via a mechanical linkage. A sensor can be integrated with or connected to the actuator to provide feedback on the position of the actuator.
[0003] Sensors on the actuator can confirm the level of deployment of the actuator, but do not provide feedback on the actual angular position of the vanes. Because of errors in each link between the actuator and the movable vane, the position of the actuator may not be indicative of the position of the movable vane. Uncertainties in the angular position of movable vanes have lead engine designers to build additional margin into engine designs, leading to un-optimized fuel burn efficiencies, performance reductions due to compensation with turbine stage design, and premature engine repair.
[0004] The challenges for determining vane position can be especially difficult in the turbine section of a gas turbine engine. The space for location of the sensor is small. Additionally, the turbine vanes are in hot environment (greater than 1000° C.) and therefore the vane angle cannot be measured using conventional angle measurement sensors such as RVDTs or resolvers. Also, the hot environment also creates challenges such as thermal thermal. At high temperatures, thermal expansion of the installation assembly is excessive which can introduce errors greater than 20% in gap measurements.
BRIEF DESCRIPTION OF THE INVENTION
[0005] According to the present invention, a movable vane control system for use with a gas turbine engine having a turbine axis of rotation comprises a plurality of turbine vanes in a gas flow path within a turbine case of the gas turbine engine. The vanes are rotatable along a vane axis to provide an angular adjustment of the vane with respect to the gas flow path. An actuator is operatively connected to the plurality of vanes. A first vane position sensor comprising a first distance sensor is configured to sense the distance between the first distance sensor and a surface portion of a first of said plurality of vanes or a first movable target connected to the first vane. Additionally, the first distance sensor, the first vane surface portion, the first movable target, or a combination thereof is configured to provide a variable distance between the first distance sensor and the first vane surface portion or first movable target that varies as a function of a position of the first vane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0007] FIG. 1 is a schematic side view of a gas turbine engine;
[0008] FIG. 2 is a schematic perspective view of a portion of a gas turbine engine including a movable vane control system;
[0009] FIG. 3 is a schematic side view of a portion of a vane position detection portion of a movable vane control system including a movable target;
[0010] FIG. 4 is a schematic side view of a portion of a vane position detection portion of a movable vane control system that includes a movable target and a reference distance sensor; and
[0011] FIG. 5 is a schematic side view of a portion of a vane position detection portion of a movable vane control system that includes a movable target having a variable distance surface portion.
DETAILED DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a schematic side view of gas turbine engine 10 . Gas turbine engine 10 includes compressor section 14 , combustor section 16 , and turbine section 18 . Low pressure spool 20 (which includes low pressure compressor 22 and low pressure turbine 24 connected by low pressure shaft 26 ) and high pressure spool 28 (which includes high pressure compressor 30 and high pressure turbine 32 connected by high pressure shaft 34 ) each extend from compressor section 14 to turbine section 18 . Propulsion fan 36 is connected to and driven by low pressure spool 20 . A fan drive gear system 38 may be included between the propulsion fan 36 and low pressure spool 20 . Air flows from compressor section 14 to turbine section 18 along engine gas flow path 40 . In alternative embodiments, gas turbine engine 10 can be of a type different than that illustrated with respect to FIG. 1 , such as a turboprop engine or an industrial gas turbine engine. The general construction and operation of gas turbine engines is well-known in the art, and does not require further detailed description herein.
[0013] FIG. 2 is a perspective view of a portion a gas turbine engine turbine section 14 including movable vane control system 42 , which includes actuator 44 , mechanical linkage assembly 46 , movable vanes (not shown) connected to vane stems 48 that extend through case 55 of turbine section 14 . Two of the movable vanes depicted in FIG. 2 have vane position sensors 52 associated therewith. Mechanical linkage assembly 46 includes torque converter 56 , synchronization ring 58 , and vane arms 60 . In the illustrated embodiment, torque converter 56 includes crank 64 connected to actuator 44 via shaft 66 and connected to synchronization ring 58 via shaft 68 . Torque converter 56 pivots on shaft 70 , which extends between supports 72 and 74 . In alternative embodiments, torque converter 56 can be another type of torque converter that functions to increase torque. Synchronization ring 58 is connected to the vane stems 48 via vane arms 60 . In alternative embodiments, actuator 44 can be connected to movable vanes without use of synchronization ring 58 .
[0014] An exemplary vane position sensor that can be used as vane position 52 or 54 is depicted in FIG. 3 . As shown in FIG. 3 , vane position sensor 52 includes a distance sensor 76 . Exemplary distance sensors include those that depend utilize an electromagnetic signal directed onto a target whose distance is to be detected, such as radio frequency (RF) distance sensors or microwave sensors by receiving an excitation signal 78 from controller 79 and returning an output signal 80 . A movable target for the distance sensor 76 is provided by inner threaded member 82 (which can also serve as vane stem 48 ) that is disposed in outer threaded member 84 that is fixed to the turbine case 55 . Inner threaded member 82 is operatively connected to blade 50 (only the end portion of blade 50 near the turbine case 55 is illustrated). By operatively connected, it is meant that the inner blade rotates along with the rotation of blade 50 in direction 86 , although the actual physical connection can be direct or indirect. Distance sensor 76 also includes measuring waveguide 88 , which directs a signal onto the inner threaded member 82 , and reference waveguide that directs a signal onto outer threaded member 84 . Distance sensor 76 is mounted such that the distance 85 between it and the outer threaded member remains fixed during rotation of the vane 50 . This is accomplished, for example, by fixedly mounting the distance sensor 76 to the turbine case 55 . During rotation of the vane 50 in direction 86 , the inner threaded member 82 also rotates in direction 86 , and the action of the threads causes inner threaded member to move up or down along the vane's rotation axis 89 as a function of the degree of rotation. Distance sensor 76 measures the distance 83 between itself and the moving inner threaded member 82 , which can be compared for reference against the measured distance 85 between the distance sensor 76 and the outer threaded member 84 to help compensate for effects of thermal expansion and other deformations that could affect the distance measurements by the distance sensor 76 . In alternative embodiments, the distance sensor 76 can be mounted so that it maintains a fixed distance to the part of the movable member that is movable axially along the vane axis 89 (in this case inner threaded member 82 ). Computing the difference between the fixed target position and moving target position can reduce the effects of tolerance stack and thermal variation such as is experienced in the turbine section of a gas turbine engine. Using this configuration for measuring displacement will provide an accurate measurement of the vane position. In addition, it provides a friction free (zero dead-band) system of measurement as there are no contacting surfaces to affect the mechanical movement.
[0015] Another exemplary embodiment of the vane position sensor 52 is shown in FIG. 4 . FIG. 4 uses a similar component layout to FIG. 3 with like numbering of components, with a couple of differences. Instead of using measurement and reference waveguides, the FIG. 4 distance sensor 76 includes a separate measurement distance sensor 92 and a reference distance sensor 94 . Also, inner member 82 ′ and outer member 84 ′ do not have threads to provide axial movement along the vane axis 89 as in FIG. 3 . Instead, inner member includes a ramp portion 96 on a surface portion facing the distance sensor 76 . Ramp portion 96 can be angled between 0° and 90° relative to the vane axis 89 , or can even be an irregular shaped surface. When inner member 82 ′ rotates along with rotation of the vane 50 , the signal from measurement sensor 92 (or alternatively from a measurement waveguide such as in FIG. 3 ) will strike a different spot on the ramped surface portion 96 depending on the degree of rotation of the inner member 82 ′, providing a measured distance 83 ′ that varies as a function of the position of vane 50 .
[0016] In some embodiments, a surface portion configured to provide a variable distance between itself and a distance sensor can be attached to or included as part of the vane instead of on a movable member that extends through the turbine case. This allows the distance sensor to be positioned inside the turbine case where it has a direct view of the actual vane to remove the linkage through the turbine case as a potential source of measurement inaccuracy. Such an exemplary embodiment is depicted in FIG. 5 , where vane 50 has a ramp portion 96 ′ on a surface portion facing the distance sensor 76 . Ramp portion 96 ′ can be angled between 0° and 90° relative to the vane axis 89 , or can even be an irregular shaped surface. When vane 50 rotates, the signal from measurement sensor 92 (or alternatively from a measurement waveguide such as in FIG. 3 ) will strike different spots on the ramped surface portion 96 ′ depending on the degree of rotation of the vane 50 , providing a measured distance 83 ″ that varies as a function of the position of vane 48 . Reference sensor 94 provides a signal to detect the distance 85 ″ from the non-ramped surface portion of the vane 50 .
[0017] In operation, controller 79 signals actuator 44 to actuate vane 50 . Actuator 44 responds by actuating torque converter 56 , which moves synchronization ring 58 and consequently moves vane arms 60 to rotate the vanes. Vane position sensor 52 sends a vane position signal representing sensed angular position of vane 50 to controller 84 . Using the vane position signal and optionally an actuator position signal from an actuator position sensor (not shown), controller 84 can determine whether vane 50 is positioned correctly or if the angular position of variable vane 50 should be adjusted. Thus, angular position of vane 50 can be adjusted based on the position signal from vane position sensor 52 . In some embodiments, controller 84 can use signals from a plurality of vane position sensors (e.g., 1-4 sensors) spaced around the turbine. In a more specific embodiment, four vane position sensors are used evenly spaced around the turbine.
[0018] The invention can be utilized on any adjustable airfoil blades in the gas turbine engine, including those in the relatively low temperature compressor section and those in the relatively high temperature turbine section that is exposed to combustion exhaust gases. Distance sensors such as RF sensors can be configured to be resistant to the conditions found in the turbine section of a gas turbine engine.
[0019] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A movable vane control system is disclosed for use with a gas turbine engine having a turbine axis of rotation. The system includes a plurality of rotatable turbine vanes in a gas flow path within a turbine case of the gas turbine engine. A first vane position sensor having a first distance sensor is configured to sense the distance between the first distance sensor and a surface portion of a first of said plurality of vanes or a first movable target connected to the first vane. Additionally, the first distance sensor, the first vane surface portion, the first movable target, or a combination thereof is configured to provide a variable distance between the first distance sensor and the first vane surface portion or first movable target that varies as a function of a position of the first vane. | 5 |
This application claims priority to U.S. Provisional Application serial No. 60/252,713 filed Nov. 22, 2000.
BACKGROUND OF THE INVENTION
The present invention relates generally to a bracket pressed over the screw housing of the worm drive clamp for attaching a worm drive clamp to a hose.
A worm drive clamp is attached to a hose to facilitate the installation of the hose on a vehicle. The clamps are made of stainless steel to provide for maximum corrosion protection. However, as quick setting glues do not bond well to stainless steel, glues are not a desirable method of attachment.
Worm drive clamps can be attached to the hose by a metal clip spot-welded to the band of the clamp. The clip is attached to the end of the hose and clinched into the interior wall. However, as the clip may damage the interior wall, this method of attachment is also undesirable.
An elastomeric patch or a woven patch of synthetic fabric have also been used as a method of attachment. The elastomeric patch is positioned over the band and vulcanized to the outer surface of the hose. A drawback to the elastomeric patch is that it is time consuming to prepare the surface of the hose and to vulcanize the elastomeric patch. The woven patch is glued over the clamp band, but is difficult to handle, making installation slow. Additionally, both types of patches are unattractive as they protrude over the exterior of the band.
In all of the above-mentioned methods of attachments, the worm drive clamp is attached to the hose at the band. A drawback associated with attaching the worm drive clamp at the band is that the worm drive clamp can twist around the outer surface of the hose as the screw is tightened, causing the screw to travel. If the screw travels into a tight space, problems can result in reaching the screw.
SUMMARY OF THE INVENTION
A bracket pressed over the screw housing of a worm drive clamp secures the worm drive clamp to a hose. The bracket is preferably made of plastic and includes a screw housing cover having a large portion and a small portion and a pair of opposing tabs. The tabs extend outside of the screw housing and have an appropriate curvature which approximately equals the curvature of the outer surface of the hose. A protrusion on each of the opposing interior surfaces of the screw housing cover secures the bracket onto the screw housing. The screw housing cover further includes a first end cap located on the front side of the large portion and a second end cap located on the opposing rear side of the small portion to maintain the position of the screw housing cover over the screw housing during assembly. Alternatively, the tabs extend inside the screw housing cover.
During assembly, the bracket is pressed onto the screw housing. After the hose is inserted into the gluing machine, glue is applied on the hose at the location where the tabs will be positioned. A gluing machine clamp block orients the worm drive clamp and brings the bracket into contact with the hose, providing pressure until the glue hardens.
The hose is then removed from the gluing machine with the bracket attached. The worm drive clamp is then tightened around the outer surface of the hose by turning the screw.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
FIG. 1 illustrates perspective view of the molded bracket of the present invention pressed over a screw housing of a worm drive clamp;
FIG. 2 illustrates a perspective view of the molded bracket;
FIG. 3 illustrates a front view of the molded bracket;
FIG. 4 illustrates a top view of the molded bracket;
FIG. 5 illustrates a perspective view of an alternative embodiment of the molded bracket; and
FIG. 6 illustrates a front view of the alternative embodiment of the molded bracket.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the bracket 10 of the present invention pressed over a screw housing 12 of a worm drive clamp 14 . As a screw 16 is turned by a screw driver, the threads of the screw 16 engage threads 18 embossed on the band 20 of the worm drive clamp 14 , tightening the worm drive clamp 14 around the outer surface 22 of a hose 24 .
As illustrated in FIG. 2, the bracket 10 includes a substantially U-shaped screw housing cover 26 and a pair of opposing outwardly extending tabs 28 . Preferably, the bracket 10 is made of plastic and is injection molded. However, the bracket 10 can also be made of metal or a thermal plastic elastomer. The tabs 28 have a width W and a length L and are an integral part of the screw housing cover 26 . The tabs 28 each have a curvature 30 which approximately equals the curvature 58 of the outer surface 22 of the hose 24 (shown in FIG. 1 ). The length L of the tabs 28 can provide a visual gage such that when the end 32 of a tab 28 is aligned with the end of the hose 24 , the bracket 10 is positioned at the proper location.
As illustrated in FIGS. 3 and 4, the screw housing cover 26 includes a large portion 34 which receives the screw housing 12 and an adjacent small portion 36 which covers the screw housing offset 38 (shown in FIG. 1 ). A first end cap 40 on the front side 42 of the large portion 34 and a second end cap 44 on the opposing rear side 46 of the small portion 36 prevent the sliding of the screw housing 12 within the bracket 10 during assembly of the bracket 10 onto the hose 24 .
The bracket 10 further includes a pair of protrusions 48 on the opposing interior surfaces 50 of the screw housing cover 26 . After the bracket 10 is pressed over the screw housing 12 , the protrusions 48 retain the bracket 10 over the screw housing 12 . Preferably, each protrusion 48 is approximately {fraction (3/16)} of an inch long and approximately 0.010 of an inch in height.
When assembling the worm drive clamp 14 to the hose 24 , the bracket 10 is pressed onto the screw housing 12 , the protrusions 48 retaining the bracket 10 over the screw housing 12 . The worm drive clamp 14 is placed into a clamp gluing machine clamp block. After inserting the hose 24 into a gluing machine, a drop of glue 52 is applied on the outer surface 22 of the hose 24 at the locations where the tabs 28 will be positioned. Preferably, the glue is cyanoacrylate glue. However, it is to be understood that other types of glue can be employed. The clamp block orients the worm drive clamp 14 over the hose 24 and brings the bracket 10 into contact with the hose 24 , providing pressure until the glue 52 hardens. After the clamp block is removed, the hose 24 is removed from the gluing machine with the bracket 10 attached. The band 20 is tightened around the outer surface 22 of the hose 24 by turning the screw 16 with a screw driver. The end caps 40 and 44 prevent sliding of the screw housing 12 as the worm drive clamp 14 is tightened, insuring later alignment of the screw driver within the screw 16 .
FIGS. 5 and 6 illustrate an alternative embodiment of the bracket 110 of the present invention. The bracket 110 includes a screw housing cover 126 and a pair of opposing inwardly extending tabs 128 having a curvature 130 which approximately equals the curvature 58 of the outer surface 22 of the hose 24 (shown in FIG. 1 ). The tabs 128 preferably are approximately 0.015 of an inch thick. The tabs 128 are separated by a gap 132 having a curvature 148 which approximately equals the curvature 54 of the band 20 . Preferably, the gap 132 is approximately 0.125 of an inch wide.
The screw housing cover 126 further includes a large portion 134 which receives the screw housing 12 and an adjacent small portion 136 which receives the screw housing cover offset 38 . A first end cap 140 on the front side 142 of the large portion 134 and a second end cap 144 on the opposing rear side 146 on the small portion 136 prevent the sliding of the screw housing 12 within the bracket 110 .
When assembling the bracket 110 on the worm drive clamp 14 , the thickness 60 of the band 20 is inserted through the gap 132 of the bracket 110 having the curvature 148 . The bracket 110 is then rotated approximately 90° such that the inner surface 56 of the band 20 overlays the inward tabs 128 . The bracket 110 is then slid over the screw housing 12 . The bracket 110 slightly flexes and opens as the bracket 110 is slid over the screw housing 12 to prevent the end caps 140 and 144 from interfering with the sliding. The worm drive clamp 14 is then attached to the tube 24 in the same manner as the bracket 10 .
An advantage of the bracket 110 is that that as the tabs 128 extend inwardly, the tabs 128 can be made larger without affecting the size of the bracket 110 . Additionally, it is easier to apply the glue 52 as there is a greater surface area for attachment. Finally, as the tabs 128 are located on the inside of the screw housing cover 126 , the bracket 110 can be positioned closer to the end of the tube 24 as the bracket 110 can be made narrower.
The bracket 10 can also be pressed over the band 20 of the worm drive clamp 14 rather than over the screw housing 12 . The bracket 10 can be over-molded around the worm drive clamp 14 or formed from strip metal. Preferably, the hose 24 is a low-permeation hose. However, other types of hoses can be employed. The bracket 10 can also be utilized with other types of clamps, such as spring steel constant tension clamps, wire band clamps, and pipe boot clamps. The bracket 10 of the present invention is low in cost and has an attractive appearance.
The foregoing description is only exemplary of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specially described. For that reason the following claims should be studied to determine the true scope and content of this invention. | A plastic bracket ( 10 ) including a screw housing cover ( 26 ) and a pair of opposing tabs ( 28 ) is pressed over a screw housing ( 12 ) of a worm drive clamp ( 14 ) to secure the worm drive clamp ( 14 ) to a hose ( 24 ). The tabs ( 28 ) can extend either be inside or outside of the screw housing cover ( 26 ). A protrusion ( 46 ) located on each of the opposing inner surfaces ( 48 ) of the screw housing cover ( 26 ) retain the bracket ( 10 ) over the screw housing ( 12 ). End caps ( 40 ) and ( 44 ) molded across opposing sides of the screw housing cover ( 26 ) maintain the position of the screw housing ( 12 ) in the screw housing cover ( 26 ) during assembly and prevent the sliding of the worm drive clamp ( 14 ). | 8 |
This is a continuation of co-pending application Ser. No. 07/621,638 filed on Dec. 3, 1990, now U.S. Pat. No. 5,082,047 which in turn is a division of application Ser. No. 07/387,141, filed Jul. 31, 1989, now U.S. Pat. No. 4,991,276.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to conveyance roller structures, in general, and to rollers for supporting and guiding metallic workpieces during heating within a furnace, in particular.
2. Description of the Prior Art
In the past, roller-type hearths have been provided in furnaces to support numerous different forms of work-pieces as, for example, a plurality of bars or slabs during heating within the furnace. Heavy metallic slabs have been heated by conveying them through successively arranged furnaces or tandem heating zones within one or more furnaces. Such workpieces are heated for a number of different reasons, all of which usually are characterized by the need to supply heated workpieces from the furnaces at a uniform temperature. The actual temperature to which these workpieces are heated depends upon the particular metalworking or treating operations but, generally, the workpieces are raised to a temperature above the critical temperature of the metal and frequently it is desired to raise the temperature of the workpiece to 2,000° F. or higher.
In some heating furnace designs, water-cooled skids are used to support the workpiece during heating. The results, however, are undesirable because pronounced cold spots are formed at each area where the workpiece was supported on the skids. This is particularly undesirable where the workpieces are heated prior to quenching, rolling, leveling and other processing operations involving metal deformations. There are other forms of furnace hearths known in the art which involve the use of rollers to support the workpiece. These rollers are typically constructed through the use of a tri-union mounted to the ends of an alloyed tube forming the roller body. The temperature of the roller is increased in essentially the same manner as the workpiece supported thereby during heating.
An improved version of such rollers is disclosed in U.S. Pat. No. 3,860,387. As disclosed therein, the roller comprises a central, axially-extending, fluid-cooled arbor surrounded by an outer tubular sleeve member which is in contact with the workpieces being heated. There is an annular space between the outer periphery of the arbor and the inner periphery of the sleeve. In this space are arcuate segments for supporting the sleeve on the arbor without materially transmitting heat from the hot outer tubular sleeve to the inner fluid cooled arbor. That is, the arcuate segments provide sufficient structural support for the outer, hot sleeve which may be at a temperature of at least 2,000° F. and the inner, much cooler fluid-cooled arbor such that the arbor does not act as a heat sink so as to produce cold spots on the outer periphery of the annular sleeve which would deleteriously affect the characteristics of the workpiece being heated.
Such a roller is useful for preventing unwanted cold spots on workpieces which are heated in the furnace. However, such a design provides no means for positively guiding or tracking a plate-like workpiece as it passes through a furnace. Without means for positively guiding a workpiece through the furnace, the workpiece may bump the walls of the furnace or even become jammed therein. Obviously, such bumping or jamming of the workpiece within the furnace may produce damage to the workpiece and/or the furnace which oftentimes requires a shutdown operation to remove the workpiece from the furnace. Such shutdowns are costly and inefficient work stoppages and are sometimes of rather great duration if significant maintenance is required to repair a damaged furnace. Therefore, other guide means must be provided to positively guide the workpiece through the furnace.
Unfortunately, however, additional guide means add undesirable cost increased heat loss and complexity to the furnace design. And even when equipped with such guides means, such a system is limited in the thickness of workpiece it can accommodate. Such a system can only be effectively used on thick workpieces having a high degree of structural integrity, i.e., workpieces which will not become too soft and then become damaged through contact with guide means within the furnace. And, as can be appreciated, the greater the thickness of the workpiece, generally the more treatment is required to reduce the workpiece to a final thickness--especially if the workpiece is to be formed into thin coiled steel strip. For obvious reasons, greater thickness rolling reductions of the workpiece add to the manufacturing cost and time required for forming the final product.
Flexible roller designs have been introduced for guiding a metallic strip workpiece as it is conveyed through the various "unheated" workstations of a production plant. Such roller designs advantageously eliminate the need for additional workpiece guide means structure to be provided. However, such designs are of no use in a high-heat furnace environment since they are formed of materials which will become severely damaged if not completely destroyed under the extreme heat conditions experienced within a furnace. Examples of such "self-centering" strip rollers are disclosed in U.S. Pat. Nos. 2,592,581, 2,660,429, 2,720,692 and 2,772,879. Each of these patents, with the exception of U.S. Pat. No. 2,660,429, disclose roller structures formed of rubber, leather, fabric or other resilient material which would be destroyed by the roughly 2,000° F. temperature produced within the heating and soaking furnace of a rolling mill production plant. U.S. Pat. No. 2,660,429 discloses an embodiment of a roller having a series of axially-spaced webs projecting from an arbor structure. However, if such a roller structure were to be subjected to the heat produced within a heating and soaking furnace and the constant weight of metallic workpieces, the laterally unsupported webs as well as the arbor will be subject to accelerated creep and permanent distortion.
An advantage exists, therefore, for a flexible conveyance and guidance roller structure for use in furnaces which avoids the creation of undesirable cold spots on the surface of a workpiece being heated while at the same time positively guides through the furnace--without any additional guide means--a class of thin, flexible and wide workpieces having little inherent structural integrity which heretofore could not be effectively passed through a furnace. With the provision of a system of such roller structures, which have particular use with thin continuously-cast plate or strip, significant reductions in cost and time are achieved in producing the final product. Still further, such a system will simplify and revolutionize the design and reduce the cost of construction of reduction mills by eliminating the need for a number of the roughing and/or finishing trains required to work a workpiece to a final product thickness.
It is therefore an object of the invention to provide an improved roller structure for positively guiding and conveying workpieces through a furnace.
It is a further object of the invention to provide a flexible roller structure for guiding and conveying workpieces through a furnace without the need for additional guide means.
It is a further object of the invention to provide a roller structure for guiding and conveying thin workpieces having little inherent structural integrity through a furnace.
It is a further object of the invention to provide a roller structure for imparting negligible cold spot areas to workpieces being heated as the workpieces are passed through a furnace.
It is yet a further object of the invention to provide a furnace roller structure which is of simple and inexpensive construction.
It is a further object of the invention to provide a system of workpiece guidance and conveyance roller structures for permitting a reduction in cost and time in producing a final workpiece product.
It is still a further object of the present invention to provide a roller structure system for permitting simplification of the design and a reduction in the construction cost of a reduction mill.
Still other objects and advantages will become apparent in light of the attached drawing figures and written description of the invention presented hereinbelow.
SUMMARY OF THE INVENTION
There is provided a roller apparatus for use in a metallic workpiece heating furnace or the like, the apparatus serving to guide and convey the workpieces through the furnace while at the same time avoiding localized cooling during heating of the workpieces. The apparatus comprises an elongated arbor formed of two concentric tube means having internal openings for coolant extending in the axial direction of the arbor. The arbor further has secured there around a series of spaced wheel-like workpiece supporting means, each including hub members having toe portions welded to the outer concentric tube means and base portions which are free to expand axially relative to the outer concentric tube means. Positioned along the outer concentric tube means between and outside of the wheel-like workpiece supporting means are packets of parallel abutting ring or disc members formed of thermally insulating material. The roller apparatus deflects under the weight of the workpieces supported thereon so as to permit the apparatus to assume a catenary shape to positively guide the workpieces in their passage through the furnace.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a continuous casting system and a reduction mill system having a furnace which uses the roller apparatus of the present invention;
FIG. 2 is a view in partial section of the roller apparatus of the present invention;
FIG. 3 is an enlarged partial sectional view of a section of the roller apparatus illustrated in FIG. 2.
FIG. 3A is a partial sectional view similar to FIG. 3 but further showing the attachment of the wheel-like workpiece supporting means to the roller;
FIG. 4 is a view of the wheel-like workpiece support means as seen along line IV--IV of FIG. 3 with some elements omitted for purposes of clarity;
FIG. 5 is a schematic plan view illustrating a staggering in the location of the wheel-like workpiece support means in a series of alternating ones of the roller devices of the present invention positioned along the length of a furnace structure;
FIG. 6 is a schematic view of the roller apparatus of the present invention assuming a catenary shape when supporting the weight of a thin, wide metallic workpiece thereon;
FIG. 7 is a schematic view similar to FIG. 6 illustrating a second embodiment of the roller apparatus of the present invention for enhancing the guidance of a workpiece through a furnace structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Depicted in FIG. 1 is a preferred application of the roller apparatus of the present invention. In that figure, there is illustrated a continuous casting device 2 including a tundish 4 for containing a quantity of molten metal 6 and a stopcock means 8 for dispensing a desired quantity of the molten metal 6 from the tundish 2. At such time when the stopcock means 8 is raised within the tundish 4 a quantity 10 of the molten metal 6 is permitted to flow by gravity into water-cooled oscillating mold 12. It is in the mold 12 that molten metal 6 first begins to solidify. A pair of gamma ray sources 14 are positioned one side of the oscillating mold 12 and project gamma rays through the mold 12. The gamma rays are then detected by receivers 16 which determine and control the desired level of metal 6 to be maintained in the mold 12.
The metal then exits the mold 12 and enters into a first straight section 18 of ,a water spray cooling zone 20. Straight section 18 is secured to and oscillates with the mold 12. Below straight section 18 is a separate stationary curved section 22 of water spray cooling zone 20. As the metal passes through water spray cooling zone 20, it is sprayed by water spraying devices 24 which are provided along the entire length of the water spray cooling zone 20. The metal, which is cast so as to be formed as a strip "S" is caused to pass smoothly into the straight section 18 and then follow the curvature of the curved section 22 by virtue of contact with a plurality of pairs of opposed rollers 26 provided along the length of the water spray cooling zone 20.
When the strip "S" exits the continuous casting device 2 it is most preferably of a thickness "t 1 " of approximately 1.5 to 2.5 inches and between approximately 36 and 65 inches in width. The strip "S" then passes through a first flying shear 28 and then into a furnace 30 which is between 500 and 800 feet in length. The strip "S", being relatively thin, becomes quite soft and malleable when heated to the working temperatures within the furnace which are typically on the order of 2200° F. Being so soft, the strip "S" cannot be guided through the furnace 30 with conventional guide means which may cause damage such as gouging, scratching or tearing or jamming of the strip through incidental contact therewith.
Therefore, in accordance with the present invention, the strip "S" is conveyed and guided through the furnace 30 by means of a plurality of unique driven roller means "R", to be described in greater detail hereinbelow, which assume a catenary shape along their rotational axes when subjected to the weight of the strip. Across its width, the heated and softened strip sags and conforms to the shape of the catenary formed by the roller means "R" and is gently but positively guided through the furnace solely by the structure of the roller means "R" thus eliminating the need for any additional guide means which might damage the strip "S" as it passes thereby. An illustration of this situation is most clearly seen in FIG. 6.
As the strip "S" exits furnace 30 it passes by a second flying shear 32 and then to a finishing train 34. Rolling mill train 34 is formed of a plurality of four-high rolling mill stands each having back-up rolls 36 and working rolls 38. After treatment by the finishing train 34 the strip is reduced from approximately 1.5 to 2.5 inches down to a thickness "t 2 " of approximately 0.1 to 0.6 inches. The shears 28 and 32 allow for severing the strip during normal operation as to coil size for maintenance operation.
The number of rolling mill stands used in the finishing train 34 can be varied as desired depending on the thickness of the strip as cast and the final desired "after-rolling" thickness of the strip.
From the finishing train 34 the strip is delivered to a run-out table 40 having driven conveyor rollers 42. Also associated with run-out table 40 are a plurality of water spraying devices 44 which provide a final cooling treatment to the strip "S" before it is coiled by a conventional down-coiler 46 having a collapsible mandrel 48.
FIG. 2 illustrates a preferred embodiment of the roller means "R" of the present invention which finds particular use in the furnace 30 depicted in FIG. 1.
The roller means "R" is comprised, inter alia, of an arbor 50 which passes at its opposite ends through apertures provided in opposite sidewalls 52 and 54 of furnace 30. The arbor 50 is formed Of an inner tubular member 56 which is surrounded by an outer tubular member 58. The outer diameter of the inner tubular member 56 is less than the inner diameter of the outer tubular member 58 so that an annular fluid passageway 70 is formed between tubular members 56 and 58 which will be described in more detail hereinbelow.
At each of its ends and exteriorly of each furnace sidewall 52 and 54, the arbor 50 is rotatably supported in pillow block bearings 60 and 62, respectively. At a first end thereof arbor 50 is attached to a rotary fluid coupling 64. Coolant is circulated through the arbor 50 via rotary coupling 64 as follows. Rotary coupling 64 receives pressurized coolant fluid from a coolant fluid source (not shown) through coolant fluid intake line 65 and transmits the coolant to an inner fluid passage 66 (FIG. 4) of inner tubular member 56. The coolant fluid travels along inner fluid passage 66 until it reaches plug means 68 which is suitably secured, as by threading or welding for example, to a second end of outer tubular member 58. The coolant fluid passing through inner fluid passage 66 is redirected upon contact with plug means 68 to flow in a reverse direction back through the aforesaid annular fluid passage 70, through rotary coupling 64 and fluid discharge line 72 to adjacent rolls, a drum bore back to the coolant fluid source. With such a coolant system in combination with other structure to be described later, the arbor 50 is advantageously cooled without acting as a heat sink which would produce undesirable cold spots on the periphery of the roller means "R" which would detrimentally affect the metallurgical characteristics of the workpiece being heated. Furthermore, the structural integrity of the arbor 50 is maintained by the cooling effect of the coolant, i.e., the arbor resists accelerated creep and sagging promoted by the combination of the weight of the strip "S" and the high heat produced within the furnace 30.
As noted previously, the second end of arbor 50 is provided with a plug means 68. Plug means 68 is part of a rotatable shaft 74 which is supported in pillow block bearing 62. The end of shaft 74 opposite to plug means 68 is secured to a flexible coupling means 76 which is connected to a driven shaft of a gear reducer 78. The gear reducer 78 is driven by a motor means 80. The motor means 80 and gear reducer 78 for each roller permit the speeds of rotation of the plurality of roller means "R" to be varied as desired in order to gradually increase the conveyance speed of the strip "S" in its travel through the furnace 30 so that it may exit the furnace 30 at a speed sufficient to enter and be treated by finishing train 34.
As can be seen in FIG. 2 and especially in FIG. 3, there are a plurality of (preferably four) workpiece supporting means in the form of spaced wheel means 82 formed of thermally dimensionally stable and heat-damage resistant material which are welded to the outer tubular member 58 of arbor 50. The wheel means 82 are preferably formed of thermally dimensionally stable alloys such as alloys of cobalt, aluminum, iron, nickel, niobium, stainless steel, or the like, in order to minimize heat transfer to the arbor 50. Wheel means 82 include inner hub sections formed of a plurality of angularly spaced base members 84 each having toe portions 86 and head portions 88 separated by a recess or gap 85 extending in the direction of the length of said arbor 50 The spaced apart toe and head portions and the spacing between the base members 84 serve to minimize metal to metal contact, thus also heat flow to arbor 50. With reference to FIG. 3A, it can be seen that only a short length weld 87 at each lateral side of each toe portion 86 interconnects about 75% of the length of the toe portion to the outer tubular member 58 while each head portion 88 is unattached and free to slide relative to outer tubular member 58 in response to the effect of differential expansion caused by a relatively large thermal gradient in the roller means "R" and the bending effect of the weight of the strip means "S" upon the roller means "R". As can be most clearly seen in FIGS. 6 and 7, the roller means "R" assumes the shape of a catenary when the weight of a strip "S" is supported thereon. Radially outwardly extending from each base member 84 is a web portion 90. Each web portion 90 is angularly separated from an adjacent web portion by an open space 92. Along with the minimal contact by base member 84 with the tubular arbor 50, the reduced cross sectional area making up the web portion because of the open spaces 92 further serve to reduce and impede heat flow to the water cooled arbor 58 by way of the base numbers 84. The segmented construction of the base members and extremely small volume of weld metal 87 reduces the heat conducting metal area to the arbor 50 even further. This permits the maximum surface temperature of the wheel surfaces thus avoiding cold spots on the strip "s". At their radially outermost extent, web portions 90 diverge and meet to form a continuous annular support for an outer workpiece-engaging rim means 94 having a surface 95 for contacting a workpiece such as strip "S". The design of the wheel and its method of attachment provide the minimum heat loss and thermal stress in the wheel while providing the maximum surface temperature on its outer perimeter.
Referring to FIGS. 2 and 3, it can be seen that in between and outside of wheel means 82 along the arbor 50 are packets of laminar abutting flexible discs 96 preferably formed of thermally-insulating ceramic fiber blanket materials; asbestos refractory materials, or the like.
The discs 98 are preferably formed to be of a diameter which is slightly less then the outermost diameter of rim means 94. Securing the packets of discs 96 between the wheel means 82 are metal rod means 98 which pass through the packets of discs 96 between each of the wheel means 82. The metal rod means 98 pass through apertures 100 formed in web portions 90 and have bent portions 102 formed at their ends for abutting against the web means 90 and anchoring the packets of discs 96 to the wheel means 82. Bulk ceramic fiber material 103 is packed on both sides of the web portions 90 of each wheel means where the metal rod means 98 pass through the web portions, i.e., at apertures 100. The bulk ceramic material 103, when compressed by the placement of discs 96, is compressed so as to be substantially as wide as rim means 94, to thus provide a substantially planar surface on each side of the web means 90 such that the positioning of the discs 98 is substantially parallel to orientation of the wheel means 82. The packets of discs 96 outside of the wheel means 82, i.e., the packets of discs 96 closest to the walls 52 and 54 of furnace 30, are retained by washers 104 which are welded to the outer tubular member 58 of arbor 50. Recesses 106 are formed in each of furnace walls 52 and 54 provide space for axial expansion of the arbor 50. As an alternative to disks 96, castable refractory material may be used between the wheel means 82 in order to insulate the roller means "R", if desired.
As can be readily appreciated, the provision of spaced wheel means 82 provides a limited degree of surface contact between the roller means "R" and the strip "S". Such limited surface contact reduces the likelihood of imparting undesirable cold spots by the roller means "R" onto the strip "S". Further ensuring the prevention of cold spots are the packets of insulation discs 96 which extend along the portion of the arbor 50 between furnace walls 52 and 54 and which prevent the temperature of the fluid-cooled arbor 50 from detrimentally affecting the strip "S" in any way. Conversely, the insulation discs 96 also prevent the heat from the furnace and/or the strip from detrimentally affecting the cooled arbor 50. It also reduces heat loss to water cooled surfaces. Furthermore, the close and dense packing of the discs 96 along the arbor 50 serves to provide lateral support for the web portions 90 of wheel means 82 to aid in preventing distortion thereof under the stresses caused by the weight of the strip "S" in combination with the high heat of the furnace.
As seen in FIG. 5, each successive roller means "R" has its plurality of wheel means 82 staggered relative to the plurality of wheel means of an adjacent roller means. This further ensures the prevention of cold spots on the heated strip "S" by providing a discontinuous and brief period of contact between the workpiece contacting surface 95 of rim means 94 and the heated strip "S". Reduction of the duration of contact between the wheel means 82 and a given portion of the strip "S" further reduces the likelihood that the wheel means 82 can act a heat sink to produce cold spots on the heated strip.
Depicted in FIG. 6, in somewhat exaggerated form, is an illustration of the flexing of the roller means "R" under the weight of the heated strip "S" and how the roller means obtains a catenary shape in axial direction to positively track the strip "S" as it passes through the furnace 30 without the need for any additional guide means. As can be seen in FIG. 6, the pillow block roller bearings 60 and 62 permit the outermost ends of the arbor 50 to be deflected upwardly at an angle "A" of up to about 4° from the horizontal depending on the weight exerted by the strip "S" on the roller means "R". The openings in the walls 52 and 54 of the furnace 30 are of sufficient dimension to permit such angular deflection of the ends of roller means "R". And, as noted previously, the strip "S" being relatively thin, i.e., approximately 1.5 to 2.5 inches, becomes quite soft and malleable and thus sags across its width to conform to the catenary shape of the roller means "R" when heated to the working temperatures within the furnace 30. The sagging of the plurality of roller means "R" and hence the strip "S" conforming thereto serves to self-center and gently guide the strip "S" along the roller means during its passage through the furnace 30 without the need for any additional guide means within the furnace which might cause damage to the softened strip as it passes thereby.
Referring now to FIG. 7, it can be seen that the centering effect of the strip "S" on the roller means "R" may be enhanced, if desired, by providing wheel means 82 of lesser diameter near the midpoint of the arbor and of greater diameter near the ends of the arbor.
The design of the roller means "R", particularly the wheel means is a major advancement in this art. The provision of a non-continuous web reduces the conduction heat losses from the surface of the roller means. The outer surface of the roller means because it cannot easily conduct heat away is hotter and less likely to cool the strip or workpiece. The hotter outer surface of the wheel means will cause high (excessive) thermal stress due to the high expansion rate of the material used to construct the wheel means. Such thermal stresses are accommodated by in design and attachment method to the arbor 50. The finger type attachment to the water cooled shaft permits deflection in the attachment which reduces thermal stresses. The limited weld and contact surface area to the water cooled shaft further reduces heat loss and aids in reducing stress.
While the present invention has been described in accordance with the preferred embodiments of the various figures, it is to be understood that other similar embodiment may be used or modifications and additions may be made to the described embodiment for performing the same functions of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment but rather construed in breadth and scope in accordance with the recitation of the appended claims. | A metallic workpiece is continuously cast and is conveyed through a furnace using a plurality of flexible driven rollers which deflect to a catenary configuration to support the workpiece. The workpiece is rolled using a single rolling mill train. The rolled workpiece is cooled and coiled. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Ser. No. 61/601,643 filed Feb. 22, 2012, entitled “Producer Snorkel or Injector Toe-Dip To Accelerate Communication Between SAGD Producer and Injector,” which is incorporated herein in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] None.
FIELD OF THE INVENTION
[0003] This invention relates to improving steam assisted gravity drainage (“SAGD”) oil production, reducing SAGD start-up time and costs, and improving overall SAGD performance.
BACKGROUND OF THE INVENTION
[0004] Enhanced Oil Recovery (abbreviated “EOR”) is a term for those techniques for increasing the amount of hydrocarbon that can be extracted from a reservoir. Enhanced oil recovery is also called improved oil recovery or tertiary recovery (as opposed to primary and secondary recovery). Using EOR, 30 to 60 percent or more of the reservoir's original oil can be extracted, compared with 20 to 40 percent using primary and secondary recovery.
[0005] SAGD is the most extensively used EOR for in situ development of the million plus centipoises bitumen resources in the McMurray Formation in the Alberta Oil Sands (Butler, 1991).
[0006] A typical SAGD process uses two horizontal wells with one above the other, where the upper one is the steam injector and the lower one is the producer, although steam can be injected into both wells in the startup phase.
[0007] The injection well is located directly above the production well, usually a short distance (5 to less than 10 meters). When steam is injected continuously into the injection well, it rises in the formation and forms a steam chamber. With continuous steam injection, the steam chamber continues to grow upward and laterally into the surrounding formation. At the interface between steam chamber and cold oil, steam condenses and the heat is transferred to the surrounding oil. The heated oil becomes mobile and drains together with condensed water to the horizontal producer due to gravity segregation within the steam vapor and liquid (heated) bitumen and steam condensate chamber.
[0008] The SAGD technique has many advantages when compared to conventional steam injection methods. In conventional steam injection, oil is displaced to a cold area where its viscosity increases and then the mobility is reduced. SAGD employs gravity as the driving force and the heated oil remains warm and movable when flowing toward the production well.
[0009] The performance of the SAGD process is determined by many factors including steam chamber development, the length, spacing and location of the two horizontal wells, heat transfer, ability to effect steam trap control to prevent inefficient production of live steam, heat loss and reservoir properties. Many studies have been done to study those elements that are important for the success of SAGD.
[0010] As shown in FIG. 1 , the standard SAGD well design employs 800 to 1000 meter slotted liners with tubing strings landed near the toe and near the heel in both an injector 101 and a producer 102 to provide two points of flow distribution control in each well, as illustrated in FIG. 1 . Steam is injected into both tubing strings at rates controlled so as to place more or less steam at each end of the completion to achieve better overall steam distribution along the horizontal injector completion.
[0011] Likewise, the producer is initially gas-lifted through both tubing strings at rates controlled to provide better inflow distribution along the completion. If steam was injected only at the heel of the injector, and water and bitumen were produced only from the heel of the producer, the tendency would be for the steam chamber to develop only near the heel. This would result in limited rates and poor steam chamber development over much of the horizontal completion.
[0012] Typically, SAGD wells are drilled about 5 meters apart vertically to achieve steam trap control whereby a gas (steam vapor)-liquid interface is maintained above the producing well to prevent short-circuiting of steam (e.g., premature breakthrough to the producing well) and undue stress on the producing well sand exclusion media. In order to establish initial communication between the wells, it is typical to circulate steam for 3 to 5 months in each well prior to starting SAGD operation. A 3 to 5 month startup time increases the amount of steam, both water and heat, required before production can begin. This added cost may limit projects available for SAGD production.
[0013] There is a need to develop more thermally efficient production techniques while increasing the economic viability of the SAGD process.
BRIEF SUMMARY OF THE DISCLOSURE
[0014] The present disclosure provides a novel process and system for increasing the thermal efficiency of SAGD operations. By connecting the toe end of the injection well with the toe end of the production well, thermal communication between the two wells is initiated directly. Flow directly from the injection tubing to the production tubing begins when steam is injected, which will significantly reduce the start-up time and cost.
[0015] In one embodiment, a single injection tube is provided to the heel end of the injection well liner and steam is pumped through the injection well liner to the connection at the toe end of the injection well to the production well liner, and finally to the heel end of the production liner and the production tube. This results in a reduction in materials, startup time, startup cost, steam oil ratio and improved production, all of which lead to capital investment savings and make SAGD production viable in a larger number of reservoirs.
[0016] In one embodiment, SAGD hydrocarbon production well having a horizontal production well is provided in a hydrocarbon reservoir. A horizontal injection well is vertically aligned above the horizontal production well, and the horizontal injector tubing or horizontal production well is provided with a hook length the well, thus fluidly connecting both the injector and production wells.
[0017] In some embodiments, more than one hooked length can connect the well pairs at more than one location along the well pairs. In other embodiments, a single hooked length joins the wells pairs at or near the toe ends of the wells.
[0018] In another embodiment, a process for steam assisted gravity drainage (SAGD) hydrocarbon production is described including installing a horizontal production well and horizontal injection well in a hydrocarbon reservoir; injecting steam into the injector well; and producing hydrocarbons from said production well, where the horizontal injector well or horizontal production well have a hook at the toe end of the well connecting the injector well and the production well.
[0019] Another embodiment provides an SAGD method, comprising:
a horizontal production well having a first toe and comprising a production tubing placed horizontally in a hydrocarbon reservoir; and a horizontal injection well having a second toe and comprising an injection tubing vertically aligned above said horizontal production well, wherein said first toe and said second toe are fluidly connected with a toe connector, thus fluidly connecting said production well and said injection well.
[0023] Preferably, the toe connector is also equipped with a flow control device, which allows the fluidic connection to be blocked, but other method of stopping flow or blocking the fluidic connection can be used, as is known in the art.
[0024] Another embodiment is an improved method of SAGD, said method comprising providing horizontal production well below a horizontal injection well, injecting steam into said injection well to mobilize hydrocarbons, and producing said mobilized hydrocarbons from said production well, the improvement comprising fluidly connecting toe ends of said production well and said injection well with a toe connector, wherein said toe connector comprises an optional flow control device.
[0025] Preferably, SAGD wells are in hydrocarbon reservoirs of heavy oil, bitumen, tar sands, asphaltenes, or combinations thereof, because SAGD is particularly beneficial for heavier oils. However, the use is not necessarily limited thereby and can be use for other hydrocarbons.
[0026] In one embodiment, SAGD hydrocarbon production is shut in for startup for between 1 and 30 days, including 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days, 15 days, 16 days, 17 days, 18 days, 19 days, 20 days, 21 days, 22 days, 23 days, 24 days, 25 days, 26 days, 27 days, 28 days, 29 days and 30 days. In yet another embodiment, steam injection and heavy oil production occur without a startup period.
[0027] As used herein, the term “SAGD” includes steam heating and gravity drainage production methods, even where combined with other techniques such as solvent assisted production methods, EM heating methods, cyclic methods and the like.
[0028] By “providing” herein we do not mean to imply contemporaneous drilling, and existing wells and liners can be used, if the toe connector can be added thereto to connect the two wells. However, in some cases, well drilling may be required at least at the toe ends to add the toe connector.
[0029] By “toe” herein, what is meant is the end or near end of a horizontal well, farthest from the vertical portion. In contrast, the horizontal portion closest the vertical portion is the “heel.”
[0030] As used herein a “hooked length” is a deviation in a horizontal well path, towards the companion well, such that the two wells will eventually be in fluid communication. The term “toe hook” refers to such as hooked length at or near the toe of the well.
[0031] By “toe connector” herein what is meant is a fluidic connection between the toe of the injection well and the toe of the producer well. The shape can vary, depending on how the connection is achieved, as shown in FIG. 3-5 .
[0032] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims or the specification means one or more than one, unless the context dictates otherwise.
[0033] The term “about” means the stated value plus or minus the margin of error of measurement or plus or minus 10% if no method of measurement is indicated.
[0034] The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or if the alternatives are mutually exclusive.
[0035] The terms “comprise”, “have”, “include” and “contain” (and their variants) are open-ended linking verbs and allow the addition of other elements when used in a claim.
[0036] The phrase “consisting of” is closed, and excludes all additional elements.
[0037] The phrase “consisting essentially of” excludes additional material elements, but allows the inclusions of non-material elements that do not substantially change the nature of the invention, such as instructions for use, adding a solvent or other EOR techniques to the inventive methods, systems and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] A more complete understanding of the present invention and benefits thereof may be acquired by referring to the follow description taken in conjunction with the accompanying drawings in which:
[0039] FIG. 1 : Typical prior art SAGD completion with toe and heel tubing in both the steam injection liner and the producing liner.
[0040] FIG. 2 : SAGD completion with a snorkel or toe connector connecting the toe end of the injection liner with the toe end of the production liner, according to one embodiment of the invention.
[0041] FIG. 3 : A SAGD configuration with production toe hooked and connected to the injection well, according to one embodiment of the invention.
[0042] FIG. 4 : A SAGD configuration with injection toe hooked and connected to the production well, according to one embodiment of the invention.
[0043] FIG. 5 : A SAGD configuration with the injection and production toe ends both hooked and connected together, according to one embodiment of the invention.
DETAILED DESCRIPTION
[0044] Turning now to the detailed description of the preferred arrangement or arrangements of the present disclosure, it should be understood that the features and concepts of this disclosure may be manifested in other arrangements and that the scope of the invention is not limited to the embodiments described or illustrated. The scope of the invention is intended only to be limited by the scope of the claims that follow.
[0045] FIG. 2 illustrates an injection well 201 that injects steam, possibly mixed with solvents or other fluids, and a production well 202 that collects heated crude oil or bitumen that flows out of the formation, along with any water from the condensation of injected steam.
[0046] As used herein SAGD refers to such a thermal hydrocarbon production process where two parallel horizontal oil wells are drilled in the formation, one about 0.5 to <10 meters above the other. In some embodiments, the injection and production wells 201 , 202 may be between 0.5 and 3, including 1, 1.5, 2, 2.5 or 3 meters apart.
[0047] The vertical distance between the injection well and the production well is crucial in the SAGD operations. Typically a magnetic guidance tool (MGT, not shown) is placed inside the production well, which is drilled first, for directional ranging. The MGT moves slightly ahead of the drilling assembly for drilling the injection well, while emitting an electromagnetic field that is picked up by the drilling assembly for the injection well such that an accurate distance between the injection and production wells can be maintained.
[0048] A toe hook 205 or ‘snorkel’ is an intentional connection at the toe end of the injection and production wells 201 , 202 that provides a fluid connection directly between the injection well 201 and the production well 202 upon startup. The toe hook 205 may be present in the injection well 201 , production well 202 or both injection and production wells 201 , 202 .
[0049] In one embodiment, the toe hook 205 is completed within the hydrocarbon reservoir. In another embodiment, the toe hook 205 is completed beyond the productive reservoir. In yet another embodiment, the toe hook 205 may be an open hole or side lateral extending away from the wellbore liner.
[0050] In another embodiment, the toe hook 205 may contain a screen, valve or other device that can be left open, or may provide support for cement, packing or another device for selectively closing the connection between the injection and production wells 201 , 202 .
[0051] As used herein, a hydrocarbon may include any petroleum reservoir including conventional oils, heavy oil, bitumen, tar sands, asphaltenes, and the like. Preferably, SAGD is used with high viscosity oils, tars or bitumens that require heating to liquefy or produce the hydrocarbon. In some instances, SAGD may be used with other hydrocarbon reservoirs as an enhanced oil recovery technique or to produce additional hydrocarbons from a reservoir. In one embodiment, SAGD is used to produce bitumen from a subterranean reservoir.
[0052] As discussed above, standard SAGD is a thermal in-situ heavy oil recovery process. The procedure is applied to at least a well pair, but multiple wells are often used. The well pairs are first drilled vertically, then slowly angled, typically 9°/100 feet until finally drilled horizontally, parallel and vertically aligned with each other. The length of and vertical separation between the injection and production wells are on the order of 1 kilometer and 5 meters, respectively.
[0053] The upper well (or wells) is known as the “injection well” and the lower well (or wells) is known as the “production well”. The process herein begins by circulating steam in both wells, preferably through the hooked length toe connector discussed here, so that the bitumen between the well pair is more efficiently heated enough to flow to the lower production well. The steam chamber heats and drains more and more bitumen until it has overtaken the oil-bearing pores between the well pair.
[0054] Steam circulation in the production well is then stopped and steam injected into the upper injection well only, so that the bitumen located above the injection well can also be heated and viscosity reduced and eventually produced through the production well. Specifically, the cone shaped steam chamber, anchored at the production well, now begins to develop upwards from the injection well. As new bitumen surfaces are heated, the oil lowers in viscosity and flows downward along the steam chamber boundary into the production well by way of gravity.
[0055] The following is a discussion of certain embodiments of the invention. Each is provided by way of explanation of the invention, one of many embodiments of the invention, and should not be read to limit, or define, the scope of the invention.
Production Toe Connected to Injection Well
[0056] FIG. 3 shows the horizontal production well 202 drilled using standard drilling techniques. A toe tip 305 of the production well 202 is deviated upward forming a communication channel, like a snorkel.
[0057] The exact shape of the communication channel is not limited, as long as thermal communication through the steam can be effectively carried out and the drilling cost is kept to the minimum. The drilling assembly is pulled back to the kickoff point of the snorkel and the horizontal section is extended to the design length of the completion. The hole is cleaned as normal and a producer liner 304 is run in the horizontal section past the snorkel (not into the snorkel).
[0058] Then, the injection well 201 is drilled above the production well 202 as normal with the intention that the tip of the injection well 201 will intersect the snorkel or pass very close to the snorkel. Then, an injector liner 303 is run in the injection well 201 . Although the injection well 201 may be drilled first, this is not standard practice and has many limitations. For example, it is difficult to maintain the vertical distance if the injection well 201 is drilled first.
[0059] In one embodiment, the toe tip 305 of the production well 202 is deviated upward approximately 7 vertical meters over less than 50 m of horizontal distance. Tighter turn radii may be used but are not required.
[0060] Alternatively, the toe tip 305 of the production well 202 may be slowly raised beyond the production zone and the injection well 201 extended to intersect with the production well 202 . The slope of the hook or snorkel may be anywhere from 7:50 as described above or 1:10, 1:7, 1:5, 1:4 or 1:3 vertical incline for each linear meter. It is to be noted that the slope of the snorkel should not affect the efficiency of thermal communication between the injection and production wells, but rather a practical result of choosing different drilling parameters.
Injection Toe Connected to Production Well
[0061] FIG. 4 illustrates the production well 202 drilled and completed first, near the bottom of the reservoir. Next, the injection well 201 is drilled above and parallel to the production well 202 as discussed above, but a toe tip 405 of the injection well 201 is “dipped” downward to connect with the production well 202 without damaging the producer liner 304 . The injector liner 303 may now be run in the injection well 201 .
[0062] In one embodiment, the injector liner 303 may employ blank pipe (not slotted) for the toe tip 405 portion except for an open screen portion at the end close to the production well 202 . This blank section may be plugged later by a ball, plug or other suitable means when appropriate.
[0063] The optional blank liner may also incorporate other devices including a valve, screen, shut-off mechanism or flow control device 406 . Although the injection well 201 may be drilled first, this is not standard practice and has many limitations. It is easier to determine if the hook is progressing correctly if the production well 202 is drilled first and the injection well 201 is dropped close to the production well 202 .
Hooking Both the Injection and Production Well
[0064] FIG. 5 shows hooking both the injection and production wells 201 , 202 with either the injection or production well drilled first. Typically, the production well 202 is drilled first and the injection well 201 drilled over and parallel to the production well 202 . This accommodates curves and undulation in the formation underburden. The production well 202 is drilled to length and hooked slightly upward at the end 507 of the well to a fixed location. The injection well 201 is drilled to a fixed distance over the production well 202 .
[0065] Once the injection well 201 is drilled to length it is hooked at the end 505 of the injection well 201 such that the injection and production wells meet at a fixed location within the formation.
[0066] The point where the injection and production wells 201 , 202 meet may be treated with a flowable proppant 506 , screen, or liners such that once the steam chamber is sufficiently formed, the toe of the well may optionally be sealed or closed. This optional procedure is not required because the steam trap will typically rise above the production well 202 .
[0067] SAGD injection, production or both injection and production wells may be hooked toward one or the other to connect the wells at the toe end of the well. Whatever drilling method employed, the resulting toes are now fluidly connected via a “toe connector.”
[0068] The toe connector may be added during an initial completion, during well work-over, or when the initial wells are extended. For some wells, it may help to improve initial startup or reduce startup time to zero. Initial production with a toe-to-toe connection can begin immediately because breakthrough is not required.
[0069] Steam may be injected through either well if startup is required.
[0070] In one embodiment, steam is injected through the injection well and returned through the production well. Because this is the same configuration used during standard SAGD production, no additional equipment, start-up equipment or changes to configuration are required. Because startup time is reduced or entirely removed, costs and steam/water to oil ratios are reduced to a minimum. This is extremely cost effective and conserves resources, useful when water and other materials are scarce or difficult to bring to the site.
[0071] Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.
[0072] All of the references cited herein are expressly incorporated by reference. The discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication data after the priority date of this application. Incorporated references are listed again here for convenience:
[0073] U.S. Pat. No. 6,158,510, Bacon, et al., “Steam distribution and production of hydrocarbons in a horizontal well.” ExxonMobil Upstream Res Co., (2000).
[0074] U.S. Pat. No. 6,119,776, Graham, et al., “Methods of stimulating and producing multiple stratified reservoirs,” Halliburton, (2000).
[0075] U.S. Pat. No. 7,559,375, U.S.20080217001, Dybevik, et al., “Flow control device for choking inflowing fluids in a well,” Reslink AS, (2008).
[0076] U.S.2010126727, Vinegar, et al., “In Situ Recovery From A Hydrocarbon Containing Formation,” Shell (2010).
[0077] U.S.20110114388, Lee, et al., “Methods and apparatus for drilling, completing and configuring U-tube boreholes,” Halliburton Energy Services, (2011).
[0078] Akin and Bagci, “A laboratory study of single-well steam-assisted gravity drainage process,” J. Petroleum Sci. Eng. 32:23-33 (2001).
[0079] Butler, “Thermal Recovery of Oil & Bitumen”, Chapter 7: “Steam-Assisted Gravity Drainage”, Prentice Hall, (1991).
[0080] Elliot and Kovscek, “A Numerical Analysis of the Single-Well Steam Assisted Gravity Drainage Process (SW-SAGD)”
[0081] Pao, Richard H. F., “Fluid Mechanics”, pp. 286-290. John Wiley & Sons, 1965.
[0082] Stalder, “Test of SAGD Flow Distribution Control Liner System, Surmont Field, Alberta, Canada.” J. Canadian Petroleum Tech., IN PROCESS. | Methods and systems relate to steam assisted gravity drainage (SAGD) utilizing well pairs that are at least initially in fluid communication through drilled bores toward their toe ends. At least one of a horizontal injection well and horizontal production well of such a well pair includes a hooked length toward toe ends of each other connecting said injection well and said production well. The methods and systems improve SAGD oil production, reduce SAGD start-up time and costs, and improve overall SAGD performance. | 4 |
CROSS-REFERENCED APPLICATION
[0001] This application is a divisional application of the U.S. application Ser. No. 12/640,622, incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0003] The present invention is related in general to equipment for servicing subterranean wells. Particularly, the invention relates to an apparatus and method for remotely launching cementing plugs during the primary cementation of a subterranean well.
[0004] Most primary cementing treatments involve the use of wiper plugs that travel through the interior of a tubular body (e.g., casing or liner). When launched, the plugs travel from the top of the tubular body to the bottom, where they become seated. The purpose of the plugs is to separate and prevent commingling of different fluids during their journey through the tubular body. In most cases, operators deploy a bottom plug and a top plug.
[0005] After the tubular body is installed in the wellbore, the annulus between the tubular body and the wellbore wall (or another tubular body) is usually filled with drilling fluid. When the primary cementing treatment commences, the bottom plug is first launched into the tubular body, followed by the cement slurry. The cement slurry may be preceded by a spacer fluid, a chemical wash or both. The function of the bottom plug is to scrape traces of drilling fluid from the internal surface of the tubular body, and to prevent contact between the drilling fluid and the cement slurry.
[0006] The bottom-plug launching and conveyance through the tubular body arises from pressure applied by the cement slurry. When the bottom plug completes its journey through the tubular body, it becomes seated on float equipment installed at the bottom of the tubular body. Continued pumping exerts sufficient pressure to rupture a membrane at the top of the bottom plug, allowing the cement slurry to flow through an interior passage in the bottom plug, exit the bottom of the tubular body and continue into the annulus.
[0007] After sufficient cement slurry to fill the annulus has been pumped into the tubular body, the top plug is launched into the tubular body, and a displacement fluid is pumped behind the plug. The displacement fluid forces the plug through the tubular body. Displacement fluids may comprise (but not be limited to) water, spacer fluids and completion fluids. The function of the top plug is to scrape traces of cement slurry from the internal surface of the tubular body, isolate the cement slurry from the displacement fluid and, upon landing on the bottom plug, seal the tubular body interior from the annulus. Unlike the bottom plug, the top plug has no membrane or interior passage through which fluids may flow.
[0008] A thorough description of the primary cementing process and the equipment employed to perform the service may be found in the following references. (1) Piot B. and Cuvillier G.: “Primary Cementing,” in Nelson E. B. and Guillot D. (eds.): Well Cementing— 2 nd Edition, Houston: Schlumberger (2006): 459-501. (2) Leugemors E., Metson J., Pessin J.-L., Colvard R. L., Krauss C. D. and Plante M.: “Cementing Equipment and Casing Hardware,” in Nelson E. B. and Guillot D. (eds.): Well Cementing— 2 nd Edition, Houston: Schlumberger (2006): 343-434.
[0009] Wiper plugs are usually launched from a cementing head that is attached to the tubular body near the drilling rig. The tubular body rises from the bottom of the openhole to the rig floor. However, for subsea completions, the problem becomes more complicated, and fluid isolation becomes more and more critical as water depth increases. It thus becomes impractical to launch wiper plugs from the surface. Therefore, the cementing head containing the wiper plugs rests on the seafloor, and the top of the tubular body ends at the mudline. Drillpipe connects the top of the tubular body to the rig floor on the surface. During the cementing process, darts are released into the drillpipe on surface, travel through the drillpipe to the seafloor and, upon arrival, trigger the release of the wiper plugs.
[0010] After the first dart is launched, cement slurry is pumped behind it. When the first dart lands inside the cementing head, the bottom plug is released. The second dart is launched after sufficient cement slurry has been pumped to fill the annulus. A displacement fluid is pumped behind the second dart. When the second dart arrives, the top plug is released. A brief peak in surface pressure indicates when each wiper plug has been launched. This process is detailed in the following references: (1) Buisine P. and Lavaure G.: “Equipment for Remote Launching of Cementing Plugs into Subsea Drilled Wells,” European Patent Application 0 450 676 A1 (1991); (2) Brandt W. et al.: “Deepening the Search for Offshore Hydrocarbons.” Oilfield Review (Spring 1998) 10, No. 1, 2-21.
[0011] Those skilled in the art will understand that process fluids may comprise drilling fluids, cement slurries, chemical washes, spacer fluids and completion fluids.
[0012] Previous plug-launching systems are configured such that the length of the dart must match the length of the plug being launched. The arrival and displacement of the dart inside the cementing head causes a rod and piston to likewise move downward into the plug basket. The distance the rod and piston move downward is equal to the axial displacement distance of the dart. The cementing-plug length may vary depending upon the casing size into which it is being launched. Therefore, it is necessary for the operator to have various sizes of darts available.
[0013] The necessity for the dart length to be equal to the plug length may also pose ergonomic problems. When longer plugs are employed, the length of the dart launching apparatus may be difficult to handle on offshore facilities.
[0014] Despite the valuable contributions of the prior art, it remains desirable, therefore, to provide an improved apparatus and methods for launching various sizes of cementing plugs.
SUMMARY OF THE INVENTION
[0015] The present invention fulfills the needs mentioned herein.
[0016] The first aspect of the invention is a system for launching cementing plugs in a subterranean well. The system comprises two portions. The first portion comprises a plug basket that initially contains at least one plug, a dart catcher that contains a hydraulic-liquid reservoir and a piston, ports through which wellbore-service fluids may flow, and a hydraulic liquid inside the reservoir that is in hydraulic communication with the plug basket. The second portion comprises at least one dart. The second portion is initially separated from the first portion. The system is designed such that, upon arrival and subsequent axial movement of the dart inside the dart catcher, the hydraulic liquid is displaced by the piston to a sufficient extent to cause the expulsion of the plug from the system.
[0017] The second aspect of the invention is a method for launching cementing plugs. The method comprises a system for launching cementing plugs in a subterranean well which comprises two portions. The first portion comprises a plug basket that initially contains at least one plug, a dart catcher that contains a hydraulic-liquid reservoir and a piston, ports through which wellbore-service fluids may flow, and a hydraulic liquid inside the reservoir that is in hydraulic communication with the plug basket. The second portion comprises at least one dart. The second portion is initially separated from the first portion. The system is designed such that, upon arrival and subsequent axial movement of the dart inside the dart catcher, the hydraulic liquid is displaced by the piston to a sufficient extent to cause the expulsion of the plug from the system.
[0018] The first portion of the system is installed inside a casing string. Process fluid is pumped into the first portion, and allowed to flow through the flow ports. A dart is launched into the process-fluid stream. Pumping of process fluid continues until the dart lands on the piston inside the dart catcher, blocking process-fluid flowing through the flow ports. Continued process-fluid pumping causes the piston to move downward into the hydraulic-liquid reservoir, forcing the plug to exit the plug basket.
[0019] The third aspect of the invention is a method for cementing a subterranean well. The method comprises a system for launching cementing plugs in a subterranean which comprises two portions. The first portion comprises a plug basket that initially contains at least one plug, a dart catcher that contains a hydraulic-liquid reservoir and a piston, ports through which wellbore-service fluids may flow, and a hydraulic liquid inside the reservoir that is in hydraulic communication with the plug basket. The second portion comprises at least one dart. The second portion is initially separated from the first portion. The system is designed such that, upon arrival and subsequent axial movement of the dart inside the dart catcher, the hydraulic liquid is displaced by the piston to a sufficient extent to cause the expulsion of the plug from the system.
[0020] The first portion of the system is installed inside a casing string. Drilling fluid is pumped into the first portion, and allowed to flow through the flow ports. A dart is launched into the drilling-fluid stream. Cement slurry is pumped behind the dart. Pumping of cement slurry continues until the dart lands on the piston inside the dart catcher, blocking fluid flow through the flow ports. Continued cement-slurry pumping causes the piston to move downward into the hydraulic-liquid reservoir, forcing the plug to exit the plug basket.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A to E illustrate the design and operation of an embodiment of the invention in which hydraulic fluid may flow from the dart catcher into a tubular body connected to the plug basket where A illustrates the fluid flowing through a tubular, a bottom dart is then launched in step B, in step C further fluid is pumped to force the bottom dart, in step D a top dart is launched and in step E further pumping force the top dart to move downward.
[0022] FIG. 2 A to E illustrate the design and operation of another embodiment of the invention that features an expandable fluid chamber and a movable plug basket where A illustrates the fluid flowing through a tubular, a bottom dart is then launched in step B and land on a piston, in step C further fluid is pumped to force the bottom dart and thus the piston downward, in step D a top dart is launched and in step E further pumping force the top dart to move downward.
DETAILED DESCRIPTION
[0023] When cementing the annular space between tubulars and the walls of a subterranean wellbore, it is usually necessary to minimize or prevent the commingling of the drilling fluid, spacer fluid and cement slurry. Commingling may result, for example, in adverse rheological effects, dilution of the cement slurry and compromised zonal isolation. One way to minimize commingling involves using wiper plugs to separate fluids as they travel down the tubulars. Wiper plugs also clean the inner surface of the tubulars. Most cementing operations involve two wiper plugs: a bottom plug that separates cement slurry from drilling fluid, and a bottom plug that separates cement slurry from displacement fluid. The bottom plug travels through the tubular body (e.g., casing) and lands on float equipment at the bottom end. Continued pumping breaks a membrane in the bottom plug, allowing cement slurry to pass through the plug and enter the annular region around the tubular body. The top plug lands on top of the bottom plug, forcing the cement slurry out of the tubular-body interior, and leaving the tubular-body interior full of displacement fluid.
[0024] The present invention is aimed at simplifying and improving the ergonomics of cementing-plug launching systems. One of the principal features of the invention is that it is no longer necessary for the length of a dart to be equal to that of the corresponding cementing plug to be launched.
[0025] The first aspect of the invention is a system for launching cementing plugs in a subterranean well. The system comprises two portions. The first portion comprises a plug basket that initially contains at least one plug, a dart catcher that contains a hydraulic-liquid reservoir and a piston, ports through which wellbore-service fluids may flow, and a hydraulic liquid inside the reservoir that is in hydraulic communication with the plug basket. The second portion comprises at least one dart. The second portion is initially separated from the first portion. The system is designed such that, upon arrival and subsequent axial movement of the dart inside the dart catcher, the hydraulic liquid is displaced by the piston to a sufficient extent to cause the expulsion of the plug from the system.
[0026] Embodiment of the first aspect of the invention, shown in FIG. 1 , may have the following characteristics. The first portion further may comprise at least one bottom plug 101 and a top plug 102 in the plug basket 103 . Above the plug basket 103 may be a first tubular body 108 containing a main rod 104 equipped with a rod piston 105 . A dart catcher 109 may be mounted above the first tubular body 108 . The dart catcher may contain a hydraulic-liquid reservoir 106 and a piston 107 . Hydraulic liquid from the reservoir 106 may flow into the first tubular body 108 , causing downward movement of the rod piston 105 and main rod 104 . Above the dart catcher may be a second tubular body 114 containing ports ( 112 and 113 ) through which wellbore-service fluids may flow. The second portion may comprise at least one bottom dart 110 , and the system may further comprise a third portion comprising a top dart 111 . The second and third portions may initially be separated from the first portion.
[0027] The internal volumes of the hydraulic-liquid reservoir 106 and the first tubular body 108 may be adjusted such that the axial displacement of rod piston 105 and main rod 104 , resulting from the axial displacement of piston 107 , and the flow of hydraulic liquid into the first tubular body 108 , is sufficient to expel a plug.
[0028] Yet other embodiment of the first aspect of the invention, shown in FIG. 2 , may have the following characteristics. The plug basket 216 of the first portion may be movable and may initially contain at least one bottom plug 201 and a top plug 202 . The first portion may further comprise a first tubular body 208 through which hydraulic fluid may flow. The first tubular body 208 may be be mounted between the movable plug basket 216 and the dart catcher 209 . Hydraulic liquid may flow from the hydraulic-liquid reservoir 216 into the first tubular body 208 and then into an expandable fluid chamber 217 . Expansion of the fluid chamber 217 upon entry of hydraulic fluid may cause the plug basket 216 to move upward, resulting in the expulsion of a cementing plug ( 201 or 202 ). Above the dart catcher may be a second tubular body 214 containing ports ( 212 and 213 ) through which wellbore-service fluids may flow. The second portion may comprise at least one bottom dart 210 , and the system may further comprise a third portion comprising a top dart 211 . The second and third portions may initially be separated from the first portion.
[0029] The internal volumes of the hydraulic-fluid reservoir 206 and the first tubular body 208 may be adjusted such that hydraulic-fluid movement through the first tubular body 208 , and subsequent filling of the expandable fluid chamber 217 arising from the arrival and displacement of a dart, cause the movable dart basket 216 to move sufficiently upward to expel a plug.
[0030] The second aspect of the invention is a method for launching cementing plugs. The method comprises a system for launching cementing plugs in a subterranean well which comprises two portions. The first portion comprises a plug basket that initially contains at least one plug, a dart catcher that contains a hydraulic-liquid reservoir and a piston, ports through which wellbore-service fluids may flow, and a hydraulic liquid inside the reservoir that is in hydraulic communication with the plug basket. The second portion comprises at least one dart. The second portion is initially separated from the first portion. The system is designed such that, upon arrival and subsequent axial movement of the dart inside the dart catcher, the hydraulic liquid is displaced by the piston to a sufficient extent to cause the expulsion of the plug from the system.
[0031] The first portion of the system is installed inside a casing string. Process fluid is pumped into the first portion, and allowed to flow through the flow ports. A dart is launched into the process-fluid stream. Pumping of process fluid continues until the dart lands on the piston inside the dart catcher, blocking process-fluid flow through the flow ports. Continued process-fluid pumping causes the piston to move downward into the hydraulic-liquid reservoir, forcing the plug to exit the plug basket.
[0032] Another embodiment of the second aspect of the invention is described below. The system selected for launching cementing plugs in a subterranean well may be further characterized by the following. The first portion may comprise at least one bottom plug 101 and a top plug 102 in the plug basket 103 . Above the plug basket 103 may be a first tubular body 108 containing a main rod 104 equipped with a rod piston 105 . A dart catcher 109 may be mounted above the first tubular body 108 . The dart catcher may contain a hydraulic-liquid reservoir 106 and a piston 107 . Hydraulic liquid from the reservoir 106 may flow into the first tubular body 108 , causing downward movement of the rod piston 105 and main rod 104 . Above the dart catcher may be a second tubular body 114 containing ports ( 112 and 113 ) through which wellbore-service fluids may flow. The second portion may comprise at least one bottom dart 110 , and the system may further comprise a third portion comprising a top dart 111 . The second and third portions may initially be separated from the first portion.
[0033] This embodiment may further comprise the following steps. The first portion is preferably installed inside a casing string 115 . A first process fluid is pumped from the surface through the second tubular body 114 . As shown in Step A, process fluid initially flows through ports 112 and 113 , bypassing the rest of the first portion of the apparatus. A bottom dart 110 is launched into the process-fluid stream in the second tubular body 114 . A second process fluid may be pumped behind the bottom dart 110 . After a desired volume of second process fluid has been pumped into the well, a top dart 111 may be launched into the process fluid stream in the second tubular body 114 , followed by a third process fluid.
[0034] Step B depicts the moment during which the bottom dart 110 lands on the piston 7 inside the dart catcher 9 . The bottom dart blocks fluid flow through ports 112 and 113 . As shown by Step C, further pumping of process fluid forces the bottom dart 110 downward, thereby forcing the piston 107 downward, thereby causing hydraulic liquid from the hydraulic-liquid reservoir 106 into the first tubular body 108 , thereby forcing the piston 107 downward. Movement of the piston 107 forces the main rod 105 into the plug basket 103 , thereby ejecting the bottom plug 101 from the plug basket. The bottom plug 101 may act as a barrier between the first and second process fluids, preventing their commingling while traveling through the interior of the casing string 115 .
[0035] In Step D, the top dart 111 has landed on the bottom dart 110 , once again obstructing fluid flow through ports 112 and 113 . A shown by Step E, further pumping causes the top dart 111 to move downward, thereby causing more hydraulic liquid to flow from the hydraulic-liquid reservoir 106 into the first tubular body 108 , thereby forcing the piston 107 further downward. Movement of the piston 107 forces the main rod 105 further into the plug basket 103 , thereby ejecting the top plug 102 from the plug basket. The top plug 102 may act as a barrier between the second and third process fluids, preventing their commingling while traveling through the interior of the casing string 115 .
[0036] The internal volumes of the hydraulic-liquid reservoir 106 and the first tubular body 108 may be adjusted such that the axial displacement of rod piston 105 and main rod 104 , resulting from the axial displacement of piston 107 , and the flow of hydraulic liquid into the first tubular body 108 , is sufficient to expel a plug.
[0037] It will be understood by those skilled the art that the internal volume of the second tubular body 114 may be less than the amount of second process fluid necessary to fill the annular region surrounding the casing string 115 . In such cases, the second portion of the first aspect of the invention, the bottom dart 110 , will reach the first portion of the first aspect of the invention before the desired quantity of second process fluid has been pumped into the second tubular body 114 . Thus, the bottom plug 101 may be launched before the top dart 111 is launched.
[0038] Yet another embodiment of the second aspect of the invention is described below. The system selected for launching cementing plugs in a subterranean well may be further characterized by the following. The plug basket 216 of the first portion may be movable and initially contains at least one bottom plug 201 and a top plug 202 . The first portion may further comprise a first tubular body 208 through which hydraulic fluid may flow. The first tubular body 208 may be mounted between the movable plug basket 216 and the dart catcher 209 . Hydraulic liquid may flow from the hydraulic-liquid reservoir 216 into the first tubular body 208 and then into an expandable fluid chamber 217 . Expansion of the fluid chamber 217 upon entry of hydraulic fluid causes the plug basket 216 to move upward, resulting in the expulsion of a cementing plug ( 201 or 202 ). Above the dart catcher may be a second tubular body 214 containing ports ( 212 and 213 ) through which wellbore-service fluids may flow. The second portion may comprise at least one bottom dart 210 , and the system may further comprise a third portion comprising a top dart 211 . The second and third portions may initially be separated from the first portion.
[0039] This embodiment may further comprise the following steps. The first portion is preferably installed inside a casing string 215 . A first process fluid may be pumped from the surface through the second tubular body 214 . As shown in Step A, the first process fluid may initially flow through ports 212 and 213 , bypassing the rest of the first portion of the apparatus. A bottom dart 210 may be launched into the first-process-fluid stream in the second tubular body 214 . A second process fluid may be pumped behind the bottom dart 210 . After a desired volume of second process fluid has been pumped into the well, a top dart 211 may be launched into the second-process-fluid stream in the second tubular body 214 , followed by a third process fluid.
[0040] Step B depicts the moment during which the bottom dart 210 lands on the piston 207 inside the dart catcher 209 . The bottom dart may block fluid flow through ports 212 and 213 . As shown by Step C, further pumping forces the bottom dart 210 downward, thereby forcing the piston 207 downward, thereby causing hydraulic liquid from the hydraulic-liquid reservoir 206 into the first tubular body 208 , thereby entering and beginning to fill the expandable fluid chamber 217 . Continued pumping and filling of the expandable fluid chamber 217 forces the plug basket 216 to move upward, thereby expelling the bottom cementing plug 201 . The bottom plug 201 may act as a barrier between the first and second process fluids, preventing their commingling while traveling through the interior of the casing string 215 .
[0041] In Step D, the top dart 211 has landed on the bottom dart 210 , once again obstructing fluid flow through ports 212 and 213 . A shown by Step E, further pumping causes the top dart 211 to move downward, thereby causing more hydraulic liquid to flow from the hydraulic-liquid reservoir 206 into the first tubular body 208 , thereby entering and further filling the expandable fluid chamber 217 . Continued pumping and filling of the expandable fluid chamber 217 forces the plug basket 216 to once again move upward, thereby expelling the top cementing plug 202 . The top plug 202 may act as a barrier between the second and third process fluids, preventing their commingling while traveling through the interior of the casing string 215 .
[0042] The internal volumes of the hydraulic-fluid reservoir 206 and the first tubular body 208 may be adjusted such that hydraulic-fluid movement through the first tubular body 208 , and subsequent filling of the expandable fluid chamber 217 arising from the arrival and displacement of a dart, cause the movable dart basket 216 to move sufficiently upward to expel a plug.
[0043] It will be understood by those skilled the art that the internal volume of the second tubular body 214 may be less than the amount of second process fluid necessary to fill the annular region surrounding the casing string 215 . In such cases, the second portion of the first aspect of the invention, the bottom dart 210 , will reach the first portion of the first aspect of the invention before the desired quantity of second process fluid has been pumped into the second tubular body 214 . Thus, the bottom plug 201 may be launched before the top dart 211 is launched.
[0044] The third aspect of the invention is a method for cementing a subterranean well. The method comprises a system for launching cementing plugs in a subterranean well which comprises two portions. The first portion comprises a plug basket that initially contains at least one plug, a dart catcher that contains a hydraulic-liquid reservoir and a piston, ports through which wellbore-service fluids may flow, and a hydraulic liquid inside the reservoir that is in hydraulic communication with the plug basket. The second portion comprises at least one dart. The second portion is initially separated from the first portion. The system is designed such that, upon arrival and subsequent axial movement of the dart inside the dart catcher, the hydraulic liquid is displaced by the piston to a sufficient extent to cause the expulsion of the plug from the system.
[0045] The first portion of the system is preferably installed inside a casing string. Drilling fluid is pumped into the first portion, and allowed to flow through the flow ports. A dart is launched into the drilling-fluid stream. Cement slurry is pumped behind the dart. Pumping of cement slurry continues until the dart lands on the piston inside the dart catcher, blocking fluid flow through the flow ports. Continued cement-slurry pumping causes the piston to move downward into the hydraulic-liquid reservoir, forcing the plug to exit the plug basket. It will be understood by those skilled in the art that the cement slurry may be preceded by a chemical wash, spacer fluid or both.
[0046] Another embodiment of the third aspect of the invention is described below. The system selected for launching cementing plugs in a subterranean well may be further characterized by the following. The first portion may comprise at least one bottom plug 101 and a top plug 102 in the plug basket 103 . Above the plug basket 103 may be a first tubular body 108 containing a main rod 104 equipped with a rod piston 105 . A dart catcher 109 may be mounted above the first tubular body 108 . The dart catcher may contain a hydraulic-liquid reservoir 106 and a piston 107 . Hydraulic liquid from the reservoir 106 may flow into the first tubular body 108 , causing downward movement of the rod piston 105 and main rod 104 . Above the dart catcher may be a second tubular body 114 containing ports ( 112 and 113 ) through which wellbore-service fluids may flow. The second portion may comprise at least one bottom dart 110 , and the system may further comprise a third portion comprising a top dart 111 . The second and third portions may initially be separated from the first portion.
[0047] This embodiment may further comprise the following steps. The first portion is preferably installed inside a casing string 115 . Drilling fluid may be pumped from the surface through the second tubular body 114 . As shown in Step A, drilling fluid may initially flow through ports 112 and 113 , bypassing the rest of the first portion of the apparatus. A bottom dart 110 may be launched into the drilling-fluid stream in the second tubular body 114 . Cement slurry may be pumped behind the bottom dart 110 . After a desired volume of cement slurry has been pumped into the well, a top dart 111 may be launched into the cement-slurry stream in the second tubular body 114 , followed by a displacement fluid.
[0048] Step B depicts the moment during which the bottom dart 110 lands on the piston 7 inside the dart catcher 9 . The bottom dart may block fluid flow through ports 112 and 113 . As shown by Step C, further pumping of displacement fluid may force the bottom dart 110 downward, thereby forcing the piston 107 downward, thereby causing hydraulic liquid from the hydraulic-liquid reservoir 106 into the first tubular body 108 , thereby forcing the piston 107 downward. Movement of the piston 107 may force the main rod 105 into the plug basket 103 , thereby ejecting the bottom plug 101 from the plug basket. The bottom plug 101 may act as a barrier between the drilling fluid and cement slurry, preventing their commingling while traveling through the interior of the casing string 115 .
[0049] In Step D, the top dart 111 has landed on the bottom dart 110 , once again obstructing fluid flow through ports 112 and 113 . A shown by Step E, further pumping may cause the top dart 111 to move downward, thereby causing more hydraulic liquid to flow from the hydraulic-liquid reservoir 106 into the first tubular body 108 , thereby forcing the piston 107 further downward. Movement of the piston 107 may force the main rod 105 further into the plug basket 103 , thereby ejecting the top plug 102 from the plug basket. The top plug 102 may act as a barrier between the cement slurry and displacement fluid, preventing their commingling while traveling through the interior of the casing string 115 .
[0050] The internal volumes of the hydraulic-liquid reservoir 106 and the first tubular body 108 may be adjusted such that the axial displacement of rod piston 105 and main rod 104 , resulting from the axial displacement of piston 107 , and the flow of hydraulic liquid into the first tubular body 108 , is sufficient to expel a plug.
[0051] It will be understood by those skilled the art that the internal volume of the second tubular body 114 may be less than the amount of cement slurry necessary to fill the annular region surrounding the casing string 115 . In such cases, the second portion of the first aspect of the invention, the bottom dart 110 , will reach the first portion of the first aspect of the invention before the desired quantity of cement slurry has been pumped into the second tubular body 114 . Thus, the bottom plug 101 may be launched before the top dart 111 is launched.
[0052] It will also be understood by those skilled in the art that the cement slurry may be preceded by a chemical wash, spacer fluid or both.
[0053] Yet another embodiment of the third aspect of the invention is described below. The system selected for launching cementing plugs in a subterranean well may be further characterized by the following. The plug basket 216 of the first portion may be movable and may initially contain at least one bottom plug 201 and a top plug 202 . The first portion may further comprise a first tubular body 208 through which hydraulic fluid may flow. The first tubular body 208 may be be mounted between the movable plug basket 216 and the dart catcher 209 . Hydraulic liquid may flow from the hydraulic-liquid reservoir 216 into the first tubular body 208 and then into an expandable fluid chamber 217 . Expansion of the fluid chamber 217 upon entry of hydraulic fluid may cause the plug basket 216 to move upward, resulting in the expulsion of a cementing plug ( 201 or 202 ). Above the dart catcher may be a second tubular body 214 containing ports ( 212 and 213 ) through which wellbore-service fluids may flow. The second portion may comprise at least one bottom dart 210 , and the system may further comprise a third portion comprising a top dart 211 . The second and third portions may initially be separated from the first portion.
[0054] This embodiment may further comprise the following steps. The first portion is preferably installed inside a casing string 215 . Drilling fluid may be pumped from the surface through the second tubular body 214 . As shown in Step A, the drilling fluid may initially flow through ports 212 and 213 , bypassing the rest of the first portion of the apparatus. A bottom dart 210 may be launched into the drilling-fluid stream in the second tubular body 214 . Cement slurry may be pumped behind the bottom dart 210 . After a desired volume of cement slurry has been pumped into the well, a top dart 211 may be launched into the cement-slurry stream in the second tubular body 214 , followed by a displacement fluid.
[0055] Step B depicts the moment during which the bottom dart 210 lands on the piston 207 inside the dart catcher 209 . The bottom dart may block fluid flow through ports 212 and 213 . As shown by Step C, further pumping may force the bottom dart 210 downward, thereby forcing the piston 207 downward, thereby causing hydraulic liquid from the hydraulic-liquid reservoir 206 into the first tubular body 208 , thereby entering and beginning to fill the expandable fluid chamber 217 . Continued pumping and filling of the expandable fluid chamber 217 may force the plug basket 216 to move upward, thereby expelling the bottom cementing plug 201 . The bottom plug 201 may act as a barrier between the drilling fluid and cement slurry, preventing their commingling while traveling through the interior of the casing string 215 .
[0056] In Step D, the top dart 211 has landed on the bottom dart 210 , once again obstructing fluid flow through ports 212 and 213 . A shown by Step E, further pumping may cause the top dart 211 to move downward, thereby causing more hydraulic liquid to flow from the hydraulic-liquid reservoir 206 into the first tubular body 208 , thereby entering and further filling the expandable fluid chamber 217 . Continued pumping and filling of the expandable fluid chamber 217 may force the plug basket 216 to once again move upward, thereby expelling the top cementing plug 202 . The top plug 202 may act as a barrier between the cement slurry and the displacement fluid, preventing their commingling while traveling through the interior of the casing string 215 .
[0057] The internal volumes of the hydraulic-fluid reservoir 206 and the first tubular body 208 may be adjusted such that hydraulic-fluid movement through the first tubular body 208 , and subsequent filling of the expandable fluid chamber 217 arising from the arrival and displacement of a dart, cause the movable dart basket 216 to move sufficiently upward to expel a plug.
[0058] It will be understood by those skilled the art that the internal volume of the second tubular body 214 may be less than the amount of second process fluid necessary to fill the annular region surrounding the casing string 215 . In such cases, the second portion of the first aspect of the invention, the bottom dart 210 , will reach the first portion of the first aspect of the invention before the desired quantity of second process fluid has been pumped into the second tubular body 214 . Thus, the bottom plug 201 may be launched before the top dart 211 is launched.
[0059] It will also be understood by those skilled in the art that the cement slurry may be preceded by a chemical wash, spacer fluid or both.
[0060] For all aspects of the invention, the hydraulic liquid may comprise a member of the list comprising: water, mineral oil, glycols, esters, polyalphaolefins or silicone oils and mixtures thereof.
[0061] For all aspects of the invention, the subterranean well may be a member of the list comprising: an oil well, a gas well, a geothermal well, a water well, a well for chemical-waste disposal, a well for enhanced recovery of hydrocarbons and a well for carbon sequestration.
[0062] The preceding description has been presented with reference to presently preferred embodiments of the invention. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope. | An apparatus for remotely launching cementing plugs is configured such that the length of a dart is not necessarily the same as the corresponding plug to be launched. Such a design presents operational and ergonomic advantages, particularly in an offshore environment. Methods for launching cementing plugs and cementing a subterranean well are also presented. | 4 |
PRIORITY INFORMATION
This application is a divisional of U.S. patent application Ser. No. 12/644,810 filed Dec. 22, 2009, now abandoned, which is a continuation of U.S. patent application Ser. No. 11/930,969, filed Oct. 31, 2007, now abandoned, which is a divisional of U.S. patent application Ser. No. 10/115,072, filed Apr. 4, 2002, now abandoned, which claims priority to Swedish Application Nos. 0101232-7, filed on Apr. 5, 2001, and 0103754-8, filed Nov. 9, 2001, and the benefit of U.S. Provisional Application 60/281,410, filed Apr. 5, 2001, the contents of each of which are incorporated herein by reference.
SEQUENCE LISTING
The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to new peptides, in particular peptides to be used for immunization therapy for treatment of atherosclerosis, and for development of peptide based ELISA for the determination of immune response against oxidized low density lipoprotein and the diagnosis of the presence or absence of atherosclerosis.
2. Brief Description of the Art
In particular the invention includes: 1) The use of any of the peptides listed in table 1, alone or in combination, native or MDA-modified, preferably together with a suitable carrier and adjuvant as an immunotherapy or “anti-atherosclerosis “vaccine” for prevention and treatment of ischemic 2) cardiovascular disease. 3) The use of the same peptides in ELISA for detection of antibodies related to increased or decreased risk of development of ischemic cardiovascular diseases.
Atherosclerosis is a chronic disease that causes a thickening of the innermost layer (the intima) of large and medium-sized arteries. It decreases blood flow and may cause ischemia and tissue destruction in organs supplied by the affected vessel. Atherosclerosis is the major cause of cardiovascular disease including myocardial infarction, stroke and peripheral artery disease. It is the major cause of death in the western world and is predicted to become the leading cause of death in the entire world within two decades.
The disease is initiated by accumulation of lipoproteins, primarily low-density lipoprotein (LDL), in the extracellular matrix of the vessel. These LDL particles aggregate and undergo oxidative modification. Oxidized LDL is toxic and cause vascular injury. Atherosclerosis represents in many respects a response to this injury including inflammation and fibrosis.
In 1989 Palinski and coworkers identified circulating autoantibodies against oxidized LDL in humans. This observation suggested that atherosclerosis may be an autoimmune disease caused by immune reactions against oxidized lipoproteins. At this time several laboratories began searching for associations between antibody titers against oxidized LDL and cardiovascular disease. However, the picture that emerged from these studies was far from clear. Antibodies existed against a large number of different epitopes in oxidized LDL, but the structure of these epitopes was unknown. The term “oxidized LDL antibodies” thus referred to an unknown mixture of different antibodies rather than to one specific antibody. T cell-independent IgM antibodies were more frequent than T-cell dependent IgG antibodies.
Antibodies against oxidized LDL were present in both patients with cardiovascular disease and in healthy controls. Although some early studies reported associations between oxidized LDL antibody titers and cardiovascular disease, others were unable to find such associations. A major weakness of these studies was that the ELISA tests used to determine antibody titers used oxidized LDL particles as ligand. LDL composition is different in different individuals, the degree of oxidative modification is difficult both to control and assess and levels of antibodies against the different epitopes in the oxidized LDL particles can not be determined. To some extent, due to the technical problems it has been difficult to evaluate the role of antibody responses against oxidized LDL using the techniques available so far, but, however, it is not possible to create well defined and reproducible components of a vaccine if one should use intact oxidized LDL particles.
Another way to investigate the possibility that autoimmune reactions against oxidized LDL in the vascular wall play a key role in the development of atherosclerosis is to immunize animals against its own oxidized LDL. The idea behind this approach is that if autoimmune reactions against oxidized LDL are reinforced using classical immunization techniques this would result in increased vascular inflammation and progressive of atherosclerosis. To test this hypothesis rabbits were immunized with homologous oxidized LDL and then induced atherosclerosis by feeding the animals a high-cholesterol diet for 3 months.
However, in contrast to the original hypothesis immunization with oxidized LDL had a protective effect reducing atherosclerosis with about 50%. Similar results were also obtained in a subsequent study in which the high-cholesterol diet was combined with vascular balloon-injury to produce a more aggressive plaque development. In parallel with our studies several other laboratories reported similar observations. Taken together the available data clearly demonstrates that there exist immune reactions that protect against the development of atherosclerosis and that these involves autoimmunity against oxidized LDL.
These observations also suggest the possibility of developing an immune therapy or “vaccine” for treatment of atherosclerosis-based cardiovascular disease in man. One approach to do this would be to immunize an individual with his own LDL after it has been oxidized by exposure to for example copper. However, this approach is complicated by the fact that it is not known which structure in oxidized LDL that is responsible for inducing the protective immunity and if oxidized LDL also may contain epitopes that may give rise to adverse immune reactions.
The identification of epitopes in oxidized LDL is important for several aspects:
First, one or several of these epitopes are likely to be responsible for activating the anti-atherogenic immune response observed in animals immunized with oxidized LDL. Peptides containing these epitopes may therefore represent a possibility for development of an immune therapy or “atherosclerosis vaccine” in man. Further, they can be used for therapeutic treatment of atheroschlerosis developed in man.
Secondly, peptides containing the identified epitopes can be used to develop ELISAs able to detect antibodies against specific structure in oxidized LDL. Such ELISAs would be more precise and reliable than ones presently available using oxidized LDL particles as antigen. It would also allow the analyses of immune responses against different epitopes in oxidized LDL associated with cardiovascular disease.
U.S. Pat. No. 5,972,890 relates to a use of peptides for diagnosing atherosclerosis. The technique presented in said US patent is as a principle a form of radiophysical diagnosis. A peptide sequence is radioactively labelled and is injected into the bloodstream. If this peptide sequence should be identical with sequences present in apolipoprotein B it will bind to the tissue where there are receptors present for apolipoprotein B. In vessels this is above all atherosclerotic plaque. The concentration of radioactivity in the wall of the vessel can then be determined e.g., by means of a gamma camera. The technique is thus a radiophysical diagnostic method based on that radioactively labelled peptide sequences will bound to their normal tissue receptors present in atherosclerotic plaque and are detected using an external radioactivity analysis. It is a direct analysis method to identify atherosclerotic plaque. It requires that the patient be given radioactive compounds.
SUMMARY OF THE INVENTION
The technique of the present invention is based on quite different principles and methods. In accordance with claim 1 the invention relates to fragments of apolipoprotein B for immunization against cardiovascular disease as well as a method for diagnosing immuno reactions against peptide sequences of apolipoprotein B. Such immuno reactions have in turn showed to be increased in individuals having a developed atherosclerosis. The present technique is based in attaching peptide sequences in the bottom of polymer wells. When a blood sample is added the peptides will bind antibodies, which are specific to these sequences. The amount of antibodies bound is then determined using an immunological method/technique. In contrast to the technique of said US patent this is thus not a direct determination method to identify and localize atherosclerotic plaque but determines an immunological response, which shows a high degree of co-variation with the extension of the atherosclerosis.
The basic principle of the present invention is thus quite different from that of said patent. The latter depends on binding of peptide sequences to the normal receptors of the lipoproteins present in atherosclerotic tissue, while the former is based on the discovery of immuno reactions against peptide sequences and determination of antibodies to these peptide sequences.
Published studies (Palinski et al., 1995, and George et al., 1998) have shown that immunization against oxidized LDL reduces the development of atherosclerosis. This would indicate that immuno reactions against oxidized LDL in general have a protecting effect. The results given herein have, however, surprisingly shown that this is not always the case. E.g., immunization using a mixture of peptides #10, 45, 154, 199, and 240 gave rise to an increase of the development of atherosclerosis. Immunization using other peptide sequences, e.g., peptide sequences #1, and 30 to 34 lacks total effect on the development of atherosclerosis. The results are surprising because they provide basis for the fact that immuno reactions against oxidized LDL, can protect against the development, contribute to the development of atherosclerosis, and be without any effect at all depending on which structures in oxidized LDL they are directed to. These findings make it possible to develop immunization methods, which isolate the activation of protecting immuno reactions. Further, they show that immunization using intact oxidized LDL could have a detrimental effect if the particles used contain a high level of structures that give rise to atherogenic immuno reactions.
WO 99/08109 relates to the use of a panel of monoclonal mouse antibodies, which bind to particles of oxidized LDL in order to determine the presence of oxidized LDL in serum and plasma. This is thus totally different from the present invention wherein a method for determining antibodies against oxidized LDL is disclosed.
U.S. Pat. No. 4,970,144 relates to a method for preparing antibodies by means of immunization using peptide sequences, which antibodies can be used for the determination of apolipoproteins using ELISA. This is thus something further quite different from the present invention.
U.S. Pat. No. 5,861,276 describes a recombinant antibody to the normal form of apolipoprotein B. This antibody is used for determining the presence of normal apolipoprotein B in plasma and serum, and for treating atherosclerosis by lowering the amount of particles of normal LDL in the circulation.
Thus in the present invention the use of antibodies are described for treating atherosclerosis. However, contrary to the U.S. Pat. No. 5,861,276, these antibodies are directed to structures present in particles of oxidized LDL and not to the normal particle of LDL. The advantage is that it is the oxidized LDL, which is supposed to give rise to the development of atherosclerosis. The use of antibodies directed to structures being specific to oxidized LDL is not described in said US patent.
Oxidation of lipoproteins, mainly LDL, in the arterial wall is believed to be an important factor in the development of atherosclerosis. Products generated during oxidation of LDL are toxic to vascular cells, cause inflammation and initiate plaque formation. Epitopes in oxidized LDL are recognized by the immune system and give rise to antibody formation. Animal experiments have shown that some of these immune responses have a protective effect against atherosclerosis. Antibodies are generally almost exclusively directed against peptide-based structures. Using a polypeptide library covering the complete sequence of the only protein present in LDL, apolipoprotein B, the epitopes have been identified in oxidized LDL that give rise to antibody formation in man. These peptide-epitopes can be used to develop ELISAs to study associations between immune responses against oxidized LDL and cardiovascular disease and to develop an immunotherapy or anti-atherosclerosis “vaccine” for prevention and treatment of ischemic cardiovascular disease.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1-6 show antibody response to the different peptides prepared in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A molecular characterization of the epitopes in oxidized LDL has been performed that give rise to antibody-dependent immune responses in man. The approach used takes advantage of the fact that immune reactions almost exclusively are directed against 5-6 amino acid long peptide sequences. LDL only contains one protein, the 4563 amino acid long apolipoprotein B. During oxidation apolipoprotein B is fragmented and aldehyde adducts coupled to positively charged amino acids, in particularly lysine. This means that peptide sequences not normally exposed because of the three dimensional structure of apolipoprotein B become accessible to immune cells and/or that normally exposed peptide sequences becomes immunogenic because haptenization with aldehydes.
It has thereby been determined that the following peptides, native or MDA derivatives possess such an efficiency as producing an immuno-response. These peptides are:
FLDTVYGNCSTHFTVKTRKG, (SEQ ID NO: 1)
PQCSTHILQWLKRVHANPLL, (SEQ ID NO: 2)
VISIPRLQAEARSEILAHWS, (SEQ ID NO: 3)
KLVKEALKESQLPTVMDFRK, (SEQ ID NO: 4)
LKFVTQAEGAKQTEATMTFK, (SEQ ID NO: 5)
DGSLRHKFLDSNIKFSHVEK, (SEQ ID NO: 6)
KGTYGLSCQRDPNTGRLNGE, (SEQ ID NO: 7)
RLNGESNLRFNSSYLQGTNQ, (SEQ ID NO: 8)
SLTSTSDLQSGIIKNTASLK, (SEQ ID NO: 9)
TASLKYENYELTLKSDTNGK, (SEQ ID NO: 10)
DMTFSKQNALLRSEYQADYE, (SEQ ID NO: 11)
MKVKIIRTIDQMQNSELQWP, (SEQ ID NO: 12)
IALDDAKINFNEKLSQLQTY, (SEQ ID NO: 13)
KTTKQSFDLSVKAQYKKNKH, (SEQ ID NO: 14)
EEEMLENVSLVCPKDATRFK, (SEQ ID NO: 15)
GSTSHHLVSRKSISAALEHK, (SEQ ID NO: 16)
IENIDFNKSGSSTASWIQNV, (SEQ ID NO: 17)
IREVTQRLNGEIQALELPQK, (SEQ ID NO: 18)
EVDVLTKYSQPEDSLIPFFE, (SEQ ID NO: 19)
HTFLIYITELLKKLQSTTVM, (SEQ ID NO: 20)
LLDIANYLMEQIQDDCTGDE, (SEQ ID NO: 21)
CTGDEDYTYKIKRVIGNMGQ, (SEQ ID NO: 22)
GNMGQTMEQLTPELKSSILK, (SEQ ID NO: 23)
SSILKCVQSTKPSLMIQKAA, (SEQ ID NO: 24)
IQKAAIQALRKMEPKDKDQE, (SEQ ID NO: 25)
RLNGESNLRFNSSYLQGTNO, (SEQ ID NO: 26)
SLNSHGLELNADILGTDKIN, (SEQ ID NO: 27)
WIQNVDTKYQIRIQIQEKLQ, (SEQ ID NO: 28)
TYISDWWTLAAKNLTDFAEQ, (SEQ ID NO: 29)
EATLQRIYSLWEHSTKNHLQ, (SEQ ID NO: 30)
ALLVPPETEEAKQVLFLDTV, (SEQ ID NO: 31)
IEIGLEGKGFEPTLEALFGK, (SEQ ID NO: 32)
SGASMKLTTNGRFREHNAKF, (SEQ ID NO: 33)
NLIGDFEVAEKINAFRAKVH, (SEQ ID NO: 34)
GHSVLTAKGMALFGEGKAEF, (SEQ ID NO: 35)
FKSSVITLNTNAELFNQSDI, (SEQ ID NO: 36)
FPDLGQEVALNANTKNQKIR, (SEQ ID NO: 37) as well as the non antibody-producing peptide
ATRFKHLRKYTYNYEAESSS, (SEQ ID NO: 38) or an active site of one or more of these peptides.
Material and Methods
To determine which parts of apolipoprotein B that become immunogenic as a result of LDL oxidation a polypeptide library consisting of 20 amino acid long peptides covering the complete human apolipoprotein B sequence was produced. The peptides were produced with a 5 amino acid overlap to cover all sequences at break points. Peptides were used in their native state, or after incorporation in phospholipid liposomes, after oxidization by exposure to copper or after malone dialdehyde (MDA)-modification to mimic the different modifications of the amino acids that may occur during oxidation of LDL.
Peptides
The 302 peptides corresponding to the entire human apolipoprotein B amino acid sequence were synthesized (Euro-Diagnostica AB, Malmo, Sweden and K J Ross Petersen A S, Horsholm, Denmark) and used in ELISA. A fraction of each synthetic peptide was modified by 0.5 M MDA (Sigma-Aldrich Sweden AB, Stockholm, Sweden) for 3 h at 37° C. and in presence of liposomes by 0.5 M MDA for 3 h at 37° C. or by 5 μM CuCl 2 (Sigma) for 18 h at 37° C. The MDA-modified peptides were dialyzed against PBS containing 1 mM EDTA with several changes for 18 h at 4° C. The modification of the peptides was tested in denatured polyacrylamide gels (Bio-Rad Laboratories, Hercules, Calif.), suitable for separation of peptides. Peptides were numbered 1-302 starting at the N-terminal end of the protein.
Other aldehydes can be used for preparing derivatives, such hydroxynonenal and others.
Liposomes
A mixture of egg phosphatidylcholine (EPC) (Sigma) and phosphatidylserine (PS) (Sigma) in a chloroform solution at a molar ratio of 9:1 and a concentration of 3 mM phospholipid (PL) was evaporated in a glass container under gentle argon stream. The container was then placed under vacuum for 3 hours. A solution containing 0.10 mM peptide (5 ml) in sterile filtered 10 mM HEPES buffer pH 7.4, 145 mM NaCl and 0.003% sodium azide was added to the EPC/PS dried film and incubated for 15 min at 50° C. The mixture was gently vortex for about 5 min at room temperature and then placed in ice-cold water bath and sonicated with 7.5 amplitude microns for 3×3 min (Sonyprep 150 MSE Sanyo, Tamro-Medlab, Sweden) with 1 min interruptions. The PL-peptide mixture, native or modified by 0.5 M MDA for 3 h at 37° C. or 5 mM CuCl 2 for 18 h at 37° C., was stored under argon in glass vials at 4° C. wrapped in aluminum foil and used within 1 week. The MDA-modified mixture was dialyzed against PBS containing 1 mM EDTA with several changes for 18 h at 4° C. before storage. The modification of the mixture was tested in denatured polyacrylamide gels (Bio-Rad Laboratories AB, Sundbyberg, Sweden), suitable for separation of peptides.
Plasma Samples
Plasma samples from 10 patients with cardiovascular disease (AHP) and 50 plasma samples, 25 women and 25 men, from normal blood donors (NHP) were collected and pooled. The two pools were aliquoted and stored in −80° C.
ELISA
Native or modified synthetic peptides diluted in PBS pH 7.4 (20 μg/ml), in presence or absence of liposomes, were absorbed to microtiter plate wells (Nunc MaxiSorp, Nunc, Roskilde, Denmark) in an overnight incubation at 4° C. As a reference, one of the peptides (P6) was run on each plate. After washing with PBS containing 0.05% Tween-20 (PBS-T) the coated plates were blocked with SuperBlock in TBS (Pierce, Rockford, Ill.) for 5 min at room temperature followed by an incubation of pooled human plasma, AHP or NHP, diluted 1/100 in TBS-0.05% Tween-20 (TBS-T) for 2 h at room temperature and then overnight at 4° C. After rinsing, deposition of auto-antibodies directed to the peptides were detected by using biotinylated rabbit anti-human IgG- or IgM-antibodies (Dako A/S, Glostrup, Denmark) appropriately diluted in TBS-T. After another incubation for 2 h at room temperature the plates were washed and the bound biotinylated antibodies were detected by alkaline phosphatase conjugated streptavidin (Sigma), incubated for 2 h at room temperature. The color reaction was developed by using phosphatase substrate kit (Pierce) and the absorbance at 405 nm was measured after 1 h of incubation at room temperature. The absorbance values of the different peptides were divided with the absorbance value of P6 and compared.
The sequences in apolipoprotein B that were recognized by antibodies in human plasma are shown as Seq. ID 1-37 in the accompanying drawing. Both AHP and NHP contained antibodies to a large number of different peptides. Antibodies against both native and modified peptides were identified. Generally antibody titers to MDA modified peptides were higher or equal to that of the corresponding native peptide. Comparison between native, MDA-modified, copper-oxidized peptide showed a high degree of correlation and that the highest antibody titers were detected using MDA-modified peptides. The use of peptides incorporated into liposomes did not result in increased antibody levels. Antibodies of the IgM subclass were more common than antibodies of the IgG subtype.
The peptides against which the highest antibody levels were detected could be divided into six groups with common characteristics (Table 1):
(A) High levels of IgG antibodies to MDA-modified peptides (n=3).
(B) High levels of IgM antibodies, but no difference between native and MDA-modified peptides (n=9).
(C) High levels of IgG antibodies, but no difference between native and MDA-modified peptides (n=2).
(D) High levels of IgG antibodies to MDA-modified peptides and at least twice as much antibodies in the NHP-pool as compared to the AHP-pool (n=5).
(E) High levels of IgM antibodies to MDA-modified peptides and at least twice as much antibodies in the NHP-pool as compared to the AHP-pool (n=11)
(F) High levels of IgG antibodies, but no difference between intact and MDA-modified peptides but at least twice as much antibodies in the AHP-pool as compared to the NHP-pool (n=7).
(G) No level of IgG or IgM antibodies
TABLE 1
A. High IgG, MDA-difference
P 11
FLDTVYGNCSTHFTVKTRKG
(SEQ ID NO: 1)
P 25.
PQCSTHILQWLKRVHANPLL
(SEQ ID NO: 2)
P 74
VISIPRLQAEARSEILAHWS
(SEQ ID NO: 3)
B. High IgM, no MDA-difference
P 40
KLVKEALKESQLPTVMDFRK
(SEQ ID NO: 4)
P 68
LKFVTQAEGAKQTEATMTFK
(SEQ ID NO: 5)
P 94
DGSLRHKFLDSNIKFSHVEK
(SEQ ID NO: 6)
P 99
KGTYGLSCQRDPNTGRLNGE
(SEQ ID NO: 7)
P 100
RLNGESNLRFNSSYLQGTNQ
(SEQ ID NO: 8)
P 102
SLTSTSDLQSGIIKNTASLK
(SEQ ID NO: 9)
P 103
TASLKYENYELTLKSDTNGK
(SEQ ID NO: 10)
P 105
DMTFSKQNALLRSEYQADYE
(SEQ ID NO: 11)
P 177
MKVKIIRTIDQMQNSELQWP
(SEQ ID NO: 12)
C. High IgG, no MDA difference
P 143
IALDDAKINFNEKLSQLQTY
(SEQ ID NO: 13)
P 210.
KTTKQSFDLSVKAQYKKNKH
(SEQ ID NO: 14)
D. NHS/AHP, IgG-ak > 2, MDA-difference
P 1
EEEMLENVSLVCPKDATRFK
(SEQ ID NO: 15)
P 129
GSTSHHLVSRKSISAALEHK
(SEQ ID NO: 16)
P 148
IENIDFNKSGSSTASWIQNV
(SEQ ID NO: 17)
P 162
IREVTQRLNGEIQALELPQK
(SEQ ID NO: 18)
P 252
EVDVLTKYSQPEDSLIPFFE
(SEQ ID NO: 19)
E. NHS/AHP, IgM-ak > 2, MDA-difference
P 301
HTFLIYITELLKKLQSTTVM
(SEQ ID NO: 20)
P 30
LLDIANYLMEQIQDDCTGDE
(SEQ ID NO: 21)
P 31
CTGDEDYTYKIKRVIGNMGQ
(SEQ ID NO: 22)
P 32
GNMGQTMEQLTPELKSSILK
(SEQ ID NO: 23)
P 33
SSILKCVQSTKPSLMIQKAA
(SEQ ID NO: 24)
P 34
IQKAAIQALRKMEPKDKDQE
(SEQ ID NO: 25)
p 100
RLNGESNLRFNSSYLQGTNQ
(SEQ ID NO: 26)
P 107
SLNSHGLELNADILGTDKIN
(SEQ ID NO: 27)
P 149
WIQNVDTKYQIRIQIQEKLQ
(SEQ ID NO: 28)
P 169
TYISDWWTLAAKNLTDFAEQ
(SEQ ID NO: 29)
P 236
EATLQRIYSLWEHSTKNHLQ
(SEQ ID NO: 30)
F. NHS/AHP, IgG-ak < 0.5, no MDA-difference
P 10
ALLVPPETEEAKQVLFLDTV
(SEQ ID NO: 31)
P 45
IEIGLEGKGFEPTLEALFGK
(SEQ ID NO: 32)
P 111
SGASMKLTTNGRFREHNAKF
(SEQ ID NO: 33)
P 154
NLIGDFEVAEKINAFRAKVH
(SEQ ID NO: 34)
P 199
GHSVLTAKGMALFGEGKAEF
(SEQ ID NO: 35)
P 222
FKSSVITLNTNAELFNQSDI
(SEQ ID NO: 36)
P 240
FPDLGQEVALNANTKNQKIR
(SEQ ID NO: 37)
G.
P 2
ATRFKHLRKYTYNYEAESSS
(SEQ ID NO: 38)
All of these 38 peptide sequences represent targets for immune reactions that may be of importance for the development of atherosclerosis and ischemic cardiovascular diseases. These peptides may therefor be used to develop ELISAs to determine the associations between antibody levels against defined sequences of MDA-modified amino acids in apolipoprotein B and risk for development of cardiovascular disease.
These peptides also represent possible mediators of the protective immunity observed in experimental animals immunized with oxidized LDL and may be used for testing in further development of an immunization therapy or “vaccine” against atherosclerosis.
Thus 38 different sequences in the human apolipoprotein B protein have been identified that give rise to significant immune responses in man. These epitopes are likely to represent what has previously been described as antibodies to oxidized LDL. Since most immune responses are directed against peptide sequences and apolipoprotein B is the only protein in LDL the approach used in this project should be able to identify the specific epitopes for essentially all antibodies against oxidized LDL-particles. A family of phospholipid specific antibodies including antibodies against cardiolipin has been described to react with oxidized LDL but the specificity and role of these antibodies remain to be fully characterized.
In many cases antibody titers were higher to MDA-modified polypeptides than to native sequences. If antibodies were detected against a MDA modified sequence it was almost always associated with presence of antibodies against the native sequence. A likely explanation to this is that the immune response against an MDA-modified amino acid sequence in apolipoprotein B (the MDA-modification occurring as a result of LDL oxidation) leads to a break of tolerance against the native sequence. For other sequences there was no difference in antibody titers against MDA-modified or native sequences. This would suggest that the immune reactions are directed against the native sequences. There should be no immune response against amino acid sequences in protein normally exposed to the immune system. In the native LDL particle large parts of the apolipoprotein B protein is hidden in phospholipid layer of LDL and therefore not accessible for the immune system. During oxidation of LDL the apolipoprotein B amino acid chain is fragmented leading to changes in the three-dimensional structure. This is likely to lead to exposure of peptide sequences normally not accessible for the immune system and to generation of antibodies against these sequences which may explain the presence of antibodies against native apolipoprotein B sequences observed. Alternatively, the true immune response is against MDA-modified sequences but the cross-reactivity with native sequences is so great that no difference in binding can be demonstrated.
TABLE 2
Associations between antibodies to different peptides and
atherosclerosis in the carotid artery
assessed as intima/media thickness in 78 subjects
(26 subjects who later developed myocardial
infarction, 26 healthy controls and
26 high-risk individuals without disease).
IgG
IgM
Peptide
Native
MDA-modified
Native
MDA-modified
301
+
10
+
+
11
++
+
25
+
+
++
+++
30
++
31
++
32
33
+
34
+
45
++
++
+++
74
++
+
+
++
99
100
+
++
102
103
+
105
129
++
+++
143
+
+
++
+
148
+
154
+++
++
162
+
++
199
210
+
240
++
++
+, r > 0.2 < 0.3, p = <0.05;
++, r > 0.3 < 0.4, p = 0.01;
+++, r > 0.4, p = <0.001,
grey, peptide antibody levels significantly increased in the group suffering from myocardial infarction.
The possibility that the ELISAs based on these peptides (native or MDA-modified) can be used to determine associations between immune reaction against defined epitopes in oxidized LDL and presence and/or risk for development of cardio-vascular disease was investigated in a pilot study. The study was performed on subjects participating in the Malmo Diet Cancer study a population based study in which over 30,000 individuals were recruited between 1989 and 1993. Antibody levels against the 24 out of 38 peptides listed in Table 1 were determined in base line plasma samples of 26 subjects who developed an acute myocardial infarction during the follow-up period and 26 healthy controls matched for age, gender and smoking. An additional group of 26 subjects, matched for age, gender, and smoking, but all with LDL cholesterol levels above 5.0 mmol/L was also included to study antibody levels in a high-risk group that has not developed cardiovascular disease.
For 19 out of the 24 peptides analyzed, significant correlations were identified between IgM antibody levels against MDA-modified peptides and the severity of atherosclerosis in the carotid artery (intima/media thickness) as assessed by ultrasound investigation of common carotid artery, i.e., the higher antibody levels the more atherosclerosis (Table 2). For many of these peptides significant correlations also existed between antibody levels to native peptides and carotid intima/media thickness. Only 4 peptides showed a significant correlation between IgG antibodies and carotid intima/media thickness. These observations suggest that ELISA using these MDA-modified peptides (alone or in combination) may be used to identify subjects with increased atherosclerosis.
Four of the peptides tested were not only associated with increased presence of atherosclerosis but were also significant elevated in the group of subjects that later suffered from a myocardial infarction (Table 2). These observations also demonstrate that peptide-based ELISA also may be used to identify subjects with an increased risk to develop myocardial infarction.
There were also significant increases in IgG antibody levels for native peptides 103, 162 and 199, as well as MDA modified 102 in the group that later suffered from myocardial infarction. However, the IgG antibodies against these peptides were not significantly associated with the presence of atherosclerosis in the carotid artery.
A particularly interesting observation was made with antibodies against MDA-modified peptide 210 for which there was significantly higher levels of IgM antibodies in the healthy controls and the high-risk group (LDL cholesterol above 5.0 mmol/L) than in the group that developed a myocardial infarction. Accordingly antibodies against MDA-modified peptide 210 may represent a marker for individuals with a decreased risk to develop cardiovascular disease.
It has now been demonstrated that immunization with native and MDA-modified apo B-100 peptide sequences results in an inhibition of atherosclerosis in experimental animals (Nordin Fredrikson, Soderberg et al, Chyu et al). The mechanisms through which these athero-protective immune responses operate remain to be fully elucidated. However, one likely possibility is that the athero-protective effect is mediated by antibodies generated against these peptides sequences. These antibodies could, for example facilitate the removal of oxidatively damaged LDL particles by macrophage Fc receptors.
Macrophage scavenger receptors only recognize LDL with extensive oxidative damage (9). Recent studies have identified the existence of circulating oxidized LDL (10,11). These particles have only minimal oxidative damage and are not recognized by scavenger receptors. Binding of antibodies to these circulating oxidized LDL particles may help to remove them from the circulation before they accumulate in the vascular tissue (12).
Several studies have supported a role for antibodies in protection against atherosclerosis. B cell reconstitution inhibits development of atherosclerosis in splenectomized apo E null mice (13) as well as neointima formation after carotid injury in RAG-1 mice (unpublished observations from our laboratory). Moreover, it has been shown that repeated injections of immunoglobulins reduce atherosclerosis in apo E null mice (6).
As discussed above antibodies against MDA-modified peptide sequences in apo B-100 may be generated by active immunization using synthetic peptides. This procedure requires 2-3 weeks before a full effect on antibody production is obtained.
In some situations a more rapid effect may be needed. One example may be unstable atherosclerotic plaques in which oxidized LDL is likely to contribute to inflammation, cell toxicity and risk for plaque rupture. Under these circumstances a passive immunization by injection of purified, or recombinantly produced antibodies against native and MDA-modified sequences may have a faster effect.
Another situation in which a passive immunization by injection of purified, or recombinantly produced antibodies may be effective is coronary heart disease in older individuals. Our studies have shown that a decrease in antibodies against apo B peptide sequences occurs with increasing age in man and is associated with an increase in the plasma level of oxidized LDL (Nordin Fredrikson, Hedblad et al). This may suggest a senescence of the immune cells responsible for producing antibodies against antigens in oxidized LDL and result in a defective clearance of oxidatively damaged LDL particles from the circulation. Accordingly, these subjects would benefit more from a passive immunization by injection of purified, or recombinantly produced antibodies than from an active immunization with apo B-100 peptide sequences.
Synthetic native peptides (Euro-Diagnostica AB, Malmo, Sweden) used in the following were peptide 1, 2 and 301 from the initially screened polypeptide library. Peptide 1 (amino acid sequence: EEEMLENVSLVCPKDATRFK, n=10; (SEQ ID NO: 15)) and peptide 301 (amino acid sequence: HTFLIYITELLKKLQSTTVM, n=10; (SEQ ID NO: 20)) were found to have higher IgG or IgM antibody response to MDA modified form than native peptide, respectively and both titers are higher in healthy subject. These peptides were chosen based on the assumption that antibody response to these peptides might be protective against atherosclerosis.
Peptide 2 (amino acid sequence: ATRFKHLRKYTYNYEAESSS, n=10; (SEQ ID NO: 38)) elicited no antibody response in the initial antibody screening, hence it was chosen as control peptide. Mice receiving Alum served as control (n=9).
Apo E (−/−) mice received subcutaneous primary immunization at 6-7 weeks of age, followed by an intra-peritoneal booster 3 weeks later. Mice were fed high cholesterol diet from the onset of immunization and continued until sacrifice at the age of 25 weeks. At the time of sacrifice, there was no significant difference in body weight among 4 groups of mice. Nor there was statistically significant difference in serum cholesterol as measured using a commercially available kit (Sigma). Their mean serum cholesterol levels were all above 715 mg/dl.
The area of the descending aorta covered by atherosclerotic plaque was measured in an en face preparation after oil red O staining. In comparison to the control group, mice immunized with peptide No. 2 and No. 301 had substantially reduced atherosclerosis ( FIG. 2 ). Immunization with Peptide No 1 did not produce a significant reduction in atherosclerosis in comparison to control. In contrast to the descending aorta, extent of atherosclerosis in the aortic root and aortic arch did not differ among the 4 experimental groups ( FIG. 3 ).
There were no difference among 4 groups in terms of aortic sinus plaque size or its lipid content (Table A). Mean plaque sizes in the aortic arches from 4 groups of mice were not different. However, en face evaluation of plaque sizes from descending thoracic and abdominal aorta by oil red O staining revealed that control group and peptide No. 1 group had similar amount of atherosclerotic plaque in the aorta, whereas peptide No. 2 and No. 9 groups had a significantly reduced atherosclerotic burden in the aorta (Table A). The observation that peptide immunization did not affect aortic sinus or aortic arch plaque size but reduced descending aortic plaque is intriguing and suggests that peptide immunization might reduce new plaque formation but does not affect the progression of plaques.
It was further tested whether peptide immunization modulates the phenotype of atherosclerotic plaques. Frozen sections form aortic sinus plaques were immunohistochemically stained with monocyte/macrophage antibody (MOMA-2, Serotec). In concordance with the findings from en face observation, peptide No. 2 significantly reduced macrophage infiltration in the plaques ( FIG. 1 ). Trichrome staining revealed a mean collage content of 40.0±7.7% in the aortic sinus plaques from peptide 2 group; whereas mean collagen content in alum control group, peptide 1 group and peptide 9 group were 32.3±5.3%, 35.6±8.5% and 29.4±9.6%, respectively.
Antibody response against immunized peptide in each group was determined. Antibody titer after immunization increased 6.1±3.1 fold in peptide 1 group, 2.4±1.0 fold in peptide 2 group and 1.8±0.6 fold in peptide 9 group; whereas alum group had a 3.9±2.7 fold increase of antibody titer against peptide 1, 2.0±0.5 fold increase against peptide 2 and 2.0±0.9 fold increase against peptide 9. It is surprising the parallel increase of antibody titer against immunized peptides both in immunized and alum treated group. This may mean the following possibilities: (1) mechanism(s) other than humoral immune response (such as cellular immune response) may be involved in modulating atherosclerosis; or (2) this increase of antibody was a bystander response to hypercholesterolemia with time.
Although there is no clear speculative mechanism to explain why peptide immunization reduced atherosclerosis and/or modulate plaque phenotype, the novelty of this invention is the concept of using peptides of LDL as immunogen and its feasibility as an immunomodulation strategy. This peptide-based immunization strategy modulates atherosclerotic plaques. Immunization using homologous oxLDL or native LDL as antigen had been shown to reduce plaque size.sup.1-3, however, the availability, production, infectious contamination and safety of homologous human LDL make this approach unappealing for clinical application. Here it is demonstrated that peptide-based immunotherapy is feasible although our final results differ from our initial hypothesis that immunization using peptides with higher IgM or IgG antibody response in normal subjects may protect experimental animals from developing advanced atherosclerotic plaques.
It is surprising to find that immunization using peptide No. 2 protected animal from developing new atherosclerotic lesions in descending aorta and reduced macrophage infiltration and a higher collagen content in plaques since this peptide did not render any antibody response from initial human screen. It may be because (a) peptide No. 2 may be a part of human apo-B-100 protein structure that was not exposed to human immune system. Hence, no antibody was generated and detected from healthy human serum pools; (b) the amino acid sequence of peptide No. 2 is foreign to mice therefore mice developed immune response against this peptide, which modulates new atherosclerotic lesion formation and its phenotype.
The effect of homologous LDL immunization on plaque size varied when plaque sizes were evaluated at different portions of aortic tree. For example, Ameli et al showed in hypercholesterolemic rabbit native LDL immunization resulted in a reduction of plaque formation in aorta 1 , whereas Freigang et al. showed reduction of plaque size in aortic sinus but not in aorta 1 . Taken their findings and the present ones together, it was speculated that peptide immunization modulates not only plaque sizes but also plaque composition. The plaque-reducing effect was only observed in descending aorta. Apo E (−/−) mice are known to develop atherosclerotic lesions at various stages of evolution in a single animal, especially when fed high cholesterol diet. The initial appearance of atherosclerotic lesion in young animal was in the aortic sinus 6,7 and after 15 weeks on high fat-high cholesterol diet lesions at aortic sinus were advanced plaques; whereas earlier stage of atherosclerosis was present in descending aorta.sup.6 Since the temporal course of plaque maturation and development in the descending aorta is late compared to that of aortic sinus, the finding that immunization reduced lesion sizes in the descending aorta but not in aortic sinus suggested immunization affects early stage of atherosclerosis formation. It is possible that as animal aged and in the presence of supra-physiological level of serum cholesterol the plaque reducing effect of immunization is overcome by the toxic effect of hypercholesterolemia. It is also possible that aortic sinus plaques mature faster and sacrifice at 25 weeks is too late to detect any difference in plaque size. Though lesion size was not modulated in the aortic sinus plaque, peptide immunization did modulate plaque compositions. The present experimental design prevented from studying the composition of the plaques in their earlier stage of development in descending aorta.
The experimental findings highlight the feasibility of using peptide sequences of LDL associated apo B-100 as immunogens for a novel approach to preventing atherosclerosis and or favorably modulating plaque phenotype despite severe hyperlipdemia. This peptide-based immunization strategy is potentially advantageous over the use of homologous oxLDL or native LDL as antigen because such a strategy could eliminate the need for isolation and preparation of homologous LDL and its attendant risks for contamination. The plaque-reducing effect of immunization with Peptide No 2 and 301 was only observed in descending aorta. These findings are consistent with previous reports where other therapeutic interventions have also been shown to have a greater effect on descending aorta compared to the aortic arch 14-17 , presumably because lesions develop more rapidly in the aortic root and the arch than the descending aorta thus creating a smaller window of opportunity for intervention 14,15,16,18,19 . Since the temporal course of plaque maturation and development in the descending aorta is late compared to that of aortic sinus and the aortic arch, the finding that immunization reduced lesion sizes in the descending aorta but not in aortic sinus and arch suggest that immunization preferentially prevents early stage of atherosclerosis formation. It is possible that as animal aged and in the presence of supra-physiological level of serum cholesterol the plaque reducing effect of immunization is overcome by the toxic effect of severe hypercholesterolemia. Though the lesion size was not modulated in the aortic sinus or arch, immunization with Peptide No 2 did modulate plaque composition in a favorable direction creating a more stable plaque phenotype with reduced macrophage infiltration and increased collagen content. In summary, it is demonstrated a novel peptide-based immunomodulatory approach for inhibition of atherosclerosis in the murine model.
In summary, it is demonstrated a novel peptide-based immunomodulatory approach in modulate atherosclerotic plaques. Although the change in atherosclerosis formation in our model was only modest, yet this peptide-based immunization may provide an alternative tool in studying, preventing or treating atherosclerosis.
Methods
Peptide preparation. Peptides were prepared using Imject® SuperCarrier® EDC kit (Pierce, Rockford, Ill.) according to manufacturer's instruction with minor modification. One mg peptide in 500 μl conjugation buffer was mixed with 2 mg carrier in 200 ml deionized water. This mixture was then incubated with 1 mg conjugation reagent (EDC, 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide HCl) in room temperature for 2 hours. This was then dialyzed against 0.083 M sodium phosphate, 0.9 M sodium chloride pH 7.2 solution overnight at 4° C. The dialyzed conjugate was diluted with Imject dry blend purification buffer to a final volume of 1.5 ml. Alum was used as immunoadjuvant and mixed with peptide conjugate with 1:1 dilution in volume. The amount of peptide in each immunization was 33 μg/100 μl per injection.
Animal protocol. Apo E (−/−) mice from the Jackson Laboratories (Bar Harbor, Me.) received subcutaneous primary immunization at 6-7 weeks of age, followed by an intra-peritoneal booster 3 weeks later. Mice were fed high cholesterol diet from the onset of immunization and continued until sacrifice at the age of 25 weeks. Blood samples were collected 2 weeks after booster and at the time of sacrifice. Mice receiving Alum served as control. Experimental protocol was approved by the Institutional Animal Care and Use Committee of Cedars-Sinai Medical Center. All mice were housed in an animal facility accredited by the American Association of Accreditation of Laboratory Animal Care and kept on a 12-hour day/night cycle and had unrestricted access to water and food. At the time of sacrifice, mice were anesthetized by inhalation Enflurane. Plasma was obtained by retro-orbital bleeding prior to sacrifice.
Tissue harvesting and sectioning. To evaluate the effect of peptide immunization on atherosclerosis formation, the plaque size at aortic sinus was assessed, aortic arch and descending thoracic and abdominal aorta. After the heart and aortic tree were perfused with normal saline at physiological pressure, the heart and proximal aorta were excised and embedded in OCT compound (Tissue-Tek) and frozen sectioned. Serial 6-μm-thick sections were collected from the appearance of at least 2 aortic valves to the disappearance of the aortic valve leaflets for aortic sinus plaque evaluation. Typically 3 consecutive sections were on one slide and a total of 25-30 slides were collected from one mouse and every fifth slide was grouped for staining. Ascending aorta and aortic arches up to left subclavian artery were also sectioned and processed similarly. Descending thoracic and abdominal aorta were processed separately for en face evaluation of plaque formation after oil red O staining.
En face preparation of descending thoracic and abdominal aorta. Chicken egg albumin (Sigma) in a concentration of 0.8 g/ml water was mixed 1:1 with glycerol. Sodium azide was added to make a final concentration of sodium azide 0.2%. After descending thoracic and abdominal aorta was cleaned off surrounding tissue and fat, the segment of aorta from left subclavian artery to the level of renal artery was then carefully removed for overnight fixation in Histochoice (Amresco). Aorta was then carefully opened longitudinally and placed with luminal side up on a slide freshly coated with egg albumin solution. After albumin solution became dry, the aorta was stained with Oil red O to assess the extent of atherosclerosis with computer-assisted histomorphometry.
Immunohistochemistry and Histomorphometry. The sections from aortic sinus were immunohistochemically stained with MOMA-2 antibody (Serotec) using standard protocol. Trichrome stain to assess collagen content and oil red O stain for plaque size and lipid content were done using standard staining protocol. Computer-assisted morphometric analysis was performed to assess histomorphometry as described previously. 8
Antibody titer measurement. To measure the antibody response after peptide immunization, an ELISA was developed. Antibody titer against immunized peptide was measured using blood collected at 2 weeks after booster and at sacrifice. Antibody response against 3 peptides was also determined in Alum group at the same time-points. In brief, native synthetic peptides diluted in PBS pH 7.4 (20 μg/ml) were absorbed to microtiter plate wells (Nunc MaxiSorp, Nunc, Roskilde, Denmark) in an overnight incubation at 4° C. After washing with PBS containing 0.05% Tween-20 (PBS-T) the coated plates were blocked with SuperBlock in TBS (Pierce) for 5 min at room temperature followed by an incubation of mouse serum diluted 1/50 in TBS-0.05% Tween-20 (TBS-T) for 2 h at room temperature and then overnight at 4° C. After rinsing, deposition of antibodies directed to the peptides was detected by using biotinylated rabbit anti-mouse Ig antibodies (Dako A/S, Glostrup, Denmark) appropriately diluted in TBS-T. After another incubation for 2 h at room temperature the plates were washed and the bound biotinylated antibodies were detected by alkaline phosphatase conjugated streptavidin (Sigma), incubated for 2 h at room temperature. Using phosphatase substrate kit (Pierce) developed the colour reaction and the absorbance at 405 nm was measured after 1 h of incubation at room temperature. Mean values were calculated after the background was subtracted.
Other assay models is of course applicable as well, such any immunoassay detecting an antibody, such as radioactive immunoassay, Western blotting, and Southern blotting, as well as detection of antibodies bound to peptides, enzyme electrodes and other methods for analysis.
Statistics
Data are presented as mean±Std. Statistical method used is listed in either text, table or figure legend. P<0.05 was considered as statistically significant.
TABLE A
Aortic sinus plaque size and its lipid content, aortic arch plaque
size and percent of plaque in descending aorta.
Total plaque
Oil red O(+)
Aortic
% of
size in
area (% of
arch
plaque
aortic sinus
aortic sinus
plaque size
in aorta
(mm 2 )
plaque)
( mm 2 )
(flat prep.)
Alum
0.49 ± 0.13
21.7 ± 4.4
0.057 ± 0.040
20 ± 4.7
Peptide 1
0.48 ± 0.14
32.0 ± 8.1
0.054 ± 0.027
17 ± 4.3
Peptide 301
0.46 ± 0.16
23.8 ± 4.1
0.050 ± 0.024
8.9 ± 2.2*
*Significant different from Alum group. ANOVA followed by Tukey-Kramer test was used for statistical analysis.
Further data on the effect of immunization with apolipoprotein B-100 peptide sequences on atherosclerosis in apo E knockout mice is given below in Table B
TABLE B
Effect of immunization with apolipoprotein B-100 peptide
sequences on atherosclerosis in apo E knockout mice
Effect on
atherosclerosis
in the aorta
Immunizations using mixtures of several peptide sequences
1. Peptide sequences 143 and 210
−64.6%
2. Peptide sequences 11, 25 and 74
−59.6%
3. Peptide sequences 129, 148 and 167
−56.8%
4. Peptide sequences 99, 100, 102, 103 and 105
−40.1%
5. Peptide sequences 30, 31, 32, 33 and 34
+6.6%
6. Peptide sequences 10, 45, 154, 199 and 240
+17.8%
Immunizations using a single peptide sequence
1. Peptide sequence 2
−67.7%
2. Peptide sequence 210
−57.9%
3. Peptide sequence 301
−55.2%
4. Peptide sequence 45
−47.4%
5. Peptide sequence 74
−31.0%
6. Peptide sequence 1
−15.4%
7. Peptide sequence 240
0%
Administration of the peptides is normally carried by injection, such as subcutaneous injection, intravenous injection, intramuscular injection or intraperitoneal injection. A first immunizing dosage can be 1 to 100 mg per patient depending on body weight, age, and other physical and medical conditions. In particular situations a local administration of a solution containing one or more of the peptides via catheter to the coronary vessels is possible as well. Oral preparations may be contemplated as well, although particular precautions must be taken to admit absorption into the blood stream. An injection dosage may contain 0.5 to 99.5% by weight of one or more of the fragments or peptides of the present invention.
The peptides are normally administered as linked to cationized bovine serum albumine, and using aluminium hydroxide as an adjuvant. Other adjuvants known in the art can be used as well.
Solutions for administration of the peptides shall not contain any EDTA or antioxidants.
The peptides can also be used as therapeutic agents in patients already suffering from an atherosclerosis. Thus any suitable administration route can be used for adding one or more of the fragments or peptides of the invention.
Initial studies focused on determining which type of oxidative modifications of peptides led to recognition by antibodies in human plasma. These studies were done using peptides 1-5 and 297-302. During oxidation of LDL polyunsaturated fatty acids in phospholipids and cholesteryl esters undergo peroxidation leading to formation of highly reactive breakdown products, such as malone dialdehyde (MDA). MDA may then form covalent adducts with lysine and histidine residues in apo B-100 making them highly immunogenic. Oxidation of LDL also results in fragmentation of apo B-100 that may lead to exposure of peptide sequences not normally accessible for the immune system. In these experiments peptides were used in their native state, after MDA modification or after incorporation into phospholipid liposomes followed by copper oxidation or MDA-modification. IgM antibodies were identified against native, MDA- and liposome oxidized peptides, with antibody titers MDA-peptide>MDA-modified liposome peptides>liposome oxidized peptide>native peptide. Specificity testing demonstrated that binding of antibodies to MDA-modified peptides was competed by both MDA-LDL and copper oxidized LDL.
We then performed a screening of the complete peptide library using pooled plasma derived from healthy control subjects and native and MDA-modified peptides as antigens. Antibodies to a large number of sites in apo B-100 were identified. Using twice the absorbance of the background control as positive titer cut off, antibodies were detected against 102 of the 302 peptides constituting the complete apo B-100 sequence. IgM binding was substantially more abundant than that of IgG. Generally, binding was higher to MDA modified peptide sequences than to the corresponding native sequence, but these was a striking correlation between the two. Binding to both native and MDA modified sequences was competed by addition of MDA-modified LDL and copper oxidized LDL, but not by native LDL. These observations suggest that immune responses against MDA-modified peptide sequences in apo B-100 results in a cross reactivity against native sequences. The inability of native LDL to compete antibody binding to native apo B-100 peptide sequences is intriguing, but may indicate that these sequences only become exposed after the proteolytic degradation of apo B-100 that occurs as a result of LDL oxidation. Both hydrophilic and hydrophobic parts of the molecule were recognized by antibodies. A second screening of the apo B-100 peptide library was performed using pooled plasma from subjects with clinical signs of coronary heart disease (CHD, acute myocardial infarction (AMI) and unstable angina; n=10). Antibodies in pooled CHD plasma bound to the same sequences and with the same overall distribution as for antibodies in healthy control plasma. However, antibody titers to several peptides (#1, 30-34, 100, 107, 148, 149, 162, 169, 236, 252 and 301) were at least twice as high as in control plasma compared to plasma from CHD subjects, whereas titers against a few peptides (#10, 45, 111, 154, 199, 222 and 240) were higher in plasma from CHD patients compared to controls. We then performed a prospective clinical study to investigate if antibody levels against MDA-modified peptide sequences in apo B-100 predict risk for development of CHD. Using a nested case control design we selected 78 subjects with coronary events (AMI or death due to CHD) and 149 controls from the Malmo Diet Cancer Study. Neither cases nor control individuals had a history of previous MI or stroke. The median time from inclusion to the acute coronary event was 2.8 years (range 0.1-5.9 years) among cases. Antibody levels were determined in baseline plasma samples supplemented with antioxidants. Using the carotid intima-media thickness (IMT) as assessed by ultrasonography at baseline we also analyzed associations between antibody levels and degree of existing vascular disease. We studied 8 MDA-modified peptide sequences that in the initial screening studies were associated with high plasma antibody levels (#74, 102 and 210) and/or marked differences between control and CHD plasma pools (#32, 45, 129, 162 and 240). Controls were found to have higher IgM levels against MDA peptide 74 (0.258, range 0-1.123 absorbance units versus 0.178, range 0-0.732 absorbance units, p<0.05), otherwise there were no differences in antibody levels between cases and controls. Associations between IMT and IgM against MDA-peptides #102, 129, and 162 (r=0.233, 0.232, and 0.234, respectively, p<0.05) were observed in cases and between IMT and MDA-peptide 45 (r=0.18, p<0.05) in controls. Weak correlations were observed between antibodies to MDA peptide 129 and total and LDL cholesterol (r=0.19 and r=0.19, p<0.01, respectively), otherwise peptide antibody levels showed no associations with total plasma cholesterol, LDL cholesterol, HDL cholesterol or plasma triglycerides. There were strong co-variations between antibody levels to the different peptides (r values ranging from 0.6 to 0.9). The only exception was antibodies against MDA-peptide 74 that were weakly or not at all related to antibodies against the other peptides.
Antibodies against all sequences except MDA-peptide 74 was inversely associated with age among cases (r values ranging from −0.38 to −0.58, p<0.010.001), but not in controls. Plasma levels of oxidized LDL, in contrast, increased with age. Again this association was stronger in cases than in controls. To investigate if the associations between immune responses against MDA-modified peptide sequences and cardiovascular disease were different in different age groups a subgroup analysis was performed on cases and controls under and above the median age (61 years). In the younger age group cases had increased antibody levels against peptides 32 and 45 and decreased antibody levels against peptide 74 as compared to controls, whereas no differences were seen in the older age group. Antibodies against all MDA peptide sequences, except peptide 74, were significantly associated with IMT in the younger age group, but not in the older (Table C).
These studies identify a number of MDA-modified sequences in apo B-100 that are recognized by human antibodies. MDA-modification of apo B-100 occurs as a result of LDL oxidation indicating that these antibodies belong to the family of previously described oxidized LDL autoantibodies. This notion is also supported by the observation that antibody binding to MDA-modified apo B-100 peptides is competed by addition of oxidized LDL. Together with the oxidized phospholipids identified by Horkko et al, these MDA-modified peptide sequences are likely to constitute the large majority of antigenic structures in oxidized LDL. In similarity with the oxidized LDL antiphospholipid antibodies, antibodies against MDA-modified apo B-100 sequences were of IgM type. This may suggest that also the latter antibodies belong to the family of T 15 natural antibodies. T 15 antibodies have been attributed an important role in the early, T cell independent defense against bacterial infections as well as in the removal of apoptotic cells. It remains to be determined if the MDA-peptide antibodies described here have similar functions. Antibodies were also identified against a large number of native apo B-100 sequences. However, the striking co-variation between antibodies to native and MDA-modified sequences suggests that also these antibodies are formed in response to LDL oxidation. It is also possible that antibodies against an MDA-modified peptide sequence cross reacts with the corresponding native sequence. If antibodies against native apo B-100 sequences bind also to native LDL particles this is likely to have a major influence on LDL metabolism. However, the finding that native LDL does not compete antibody binding to native apo B-100 sequences, as well as the lack of correlation between antibodies against native apo B-100 sequences and LDL cholesterol levels against the existence of such a phenomena.
Antibodies against MDA-modified peptide sequences decreased progressively with age in the cases, but not in the controls. With the exception of MDA-peptide 74, IgM antibodies against MDA-peptides were significantly associated with carotid IMT in the younger age group (below 62 years), but not in the older age group. These findings suggest that significant changes in the interactions between the immune system and the atherosclerotic vascular wall takes place between ages 50 and 70 years. One possibility is that in younger individuals the atherosclerotic disease process is at a more active stage with a more prominent involvement of immune cells. Another possibility is that the decreased levels of antibodies against MDA-modified peptide sequences in older subjects reflect a senescence of the immune cells involved in atherosclerosis. An impaired function of immune cells due to immunosenescence have been proposed to contribute to an increased susceptibility to infection and cancer in the older population. Interestingly, immunosenescence is inhibited by antioxidants indicating involvement of oxidative stress. Immune cells that interact with epitopes in oxidized LDL are likely to be particularly exposed to oxidative stress. Since oxidized LDL is present in arteries already at a very early age these immune response are being continuously challenged for several decades, which may further contribute to a development of immunosenescence.
Increased antibodies against two sites in apo B-100 were found to predict risk for myocardial infarction and coronary death in subjects below 62 years of age. Antibodies against these sites showed a high level of co-variation suggesting that they were produced in response to the same underlying pathophysiological processes. The fact that the median time from blood sampling to coronary event was only 2.8 years makes these antibodies particularly interesting as makers for increased CHD risk. Antibody levels against MDA-modified apo B-100 peptide sequences showed no associations with other CHD risk factors such as hyperlipidemia, hypertension and diabetes suggesting that they are independent markers of CHD risk. The CHD cases in the present study were not extremely high-risk individuals and in this respect representative of the common CHD patient. The finding that IgM against MDA-modified apo B-100 sequences predicts short-term risk for development of acute coronary events in individuals that would not have been identified as high risk by screening of established risk factors suggest that it may become a useful instrument in identifying individuals in need of aggressive preventive treatment. However, considerably larger prospective studies with multivariate analysis are required before the clinical value of determining antibodies against apo B-100 MDA-modified peptide sequences can be fully established. Another limitation of the present clinical study is that we have only analyzed antibodies against a small number of the antigenic sites in apo B-100 and that antibody titers against other sites may be even better markers of cardiovascular risk.
In subjects below age 60 antibodies against a large number of MDA-modified sites in apo B-100 were correlated with the extent of existing vascular disease as assessed by carotid IMT. IgM antibodies were more closely associated with carotid IMT than IgG antibodies. Although carotid IMT has obvious limitations as a measure of general atherosclerotic burden these observations still suggest that determination of IgM against MDA-modified sequences in apo B-100 may be one method to assess the severity of existing atherosclerosis. These observations are also in line with several previous studies that have reported associations between coronary and carotid artery disease and IgM antibodies against oxidized LDL.
Antibodies against peptide 74 differed against other apo B-100 peptide antibodies in many respect. They were higher in controls than in cases, they did not decrease with age and were not associated with the extent of carotid disease. Accordingly, antibodies against this peptide sequence represent interesting candidates for an athero-protective immune response.
An important question is why these associations occur. They clearly demonstrate that immune responses against MDA-modified apo B-100 sites somehow are involved in the atherosclerosic disease process. Since high antibody levels are associated with more severe atherosclerosis and increased risk for development of acute coronary events one obvious possibility is that these immune responses promote atherogenesis. Studies demonstrating that immune responses against heat shock proteins, such as HSP 65, are atherogenic provide some support for this notion. However, experimental animal studies have shown an athero-protective effect of oxidized LDL immunization. B cell reconstitution of splenectomized apo E null mice results in a decrease in atherosclerosis. Reduced atherosclerosis has also been observed in apo E null mice given repeated injections of immunoglobulin. The present observations do not necessarily argue against an athero-protective role of immune responses against oxidized LDL. These immune responses are activated by pro-atherogenic processes such as LDL oxidation. Accordingly, they are also likely to be in proportion to the severity of the disease process and could serve as makers of disease severity and CHD risk without contributing to disease progression. The finding that immunization of apo E null mice with apo B-100 peptide sequences inhibits development of atherosclerosis reported in two accompanying papers demonstrates that this is likely to be the case. Indeed, the most important outcome of the present study may well be the identification of structures that could be used as components of a vaccine against atherosclerosis. The observation that the decrease in antibodies against MDA-modified peptide sequences in apo B-100 that occurs with age is accompanied by an increase in plasma levels of oxidized LDL suggest that an increased clearance of minimally oxidized LDL from the circulation may be one mechanism by which these antibodies could protect against atherosclerosis.
Methods
Study Population
The study subjects, born between 1926-45, belong to the Malmo “Diet and Cancer (MDC)” study cohort. A random 50% of those who entered the MDC study between November 1991 and February 1994 were invited to take part in a study on the epidemiology of carotid artery disease. Routines for ascertainment of information on morbidity and mortality following the health examination, as well as definition of traditional risk factors, have been reported.
Eighty-five cases of acute coronary heart events, i.e. fatal or non-fatal MI or deaths due to coronary heart disease (CHD) were identified. Participants who had a history of myocardial infarction or stroke (n=6) were not eligible for the present study. For each case two controls without a history of myocardial infarction or stroke was individually matched for age, sex, smoking habits, presence of hypertension and month of participation in the screening examination and duration of follow-up. Due to logistic reason (blood samples were not available in sufficient quantity for assessment of peptides) only one control was available for seven cases and no controls for one case. This case was excluded from analysis. Thus the study population consists of 227 subjects, 78 cases and 149 controls, aged 49-67 (median 61) years at baseline.
Laboratory Analyses
After overnight fasting blood samples were drawn for the determination of serum values of total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol and whole blood glucose. LDL cholesterol in mmol/L was calculated according to the Friedewald formula. Oxidized LDL was measured by ELISA (Mercordia).
B-Mode Ultrasound Vasculography
An Acuson 128 Computed Tomography System (Acuson, Mountain View, Calif.) with a MHz transducer was used for the assessment of carotid plaques in the right carotid artery as described previously.
Development of ELISAs Against Apo B-100 Peptide Sequences
The 302 peptides corresponding to the entire human apolipoprotein B amino acid sequence were synthesized (Euro-Diagnostica AB, Malmo, Sweden and K J Ross Petersen A S, Horsholm, Denmark) and used in ELISA. A fraction of each synthetic peptide was modified by 0.5 M MDA (Sigma-Aldrich Sweden AB, Stockholm, Sweden) for 3 h at 37° C. and in presence of liposomes by 0.5 M MDA for 3 h at 37° C. or by 5 mM CUC1 2 (Sigma) for 18 h at 37° C. The MDA modified peptides were dialyzed against PBS containing 1 mM EDTA with several changes for 18 h at 4° C. The modification of the peptides was tested in denatured polyacrylamide gels (BioRad Laboratories, Hercules, Calif.), suitable for separation of peptides.
A mixture of egg phosphatidylcholine (EPC) (Sigma) and phosphatidylserine (PS) (Sigma) in a chloroform solution at a molar ratio of 9:1 and a concentration of 3 mM phospholipid (PL) was evaporated in a glass container under gentle argon stream. The container was then placed under vacuum for 3 hours. A solution containing 0.10 mM peptide (5 ml) in sterile filtered 10 mM HEPES buffer pH 7.4, 145 mM NaCl and 0.003% sodium azide was added to the EPC/PS dried film and incubated for 15 min at 50° C. The mixture was gently vortex for about 5 min at room temperature and then placed in ice-cold water bath and sonicated with 7.5 amplitude microns for 3×3 min (Sonyprep 150 MSE Sanyo, Tamro-Medlab, Sweden) with 1 min interruptions. The PL-peptide mixture, native or modified by 0.5 M MDA for 311 at 37° C. or 5 mM CUC1.sub.2 for 18 h at 37° C., was stored under argon in glass vials at 4° C. wrapped in aluminum foil and used within 1 week. The MDA-modified mixture was dialyzed against PBS containing 1 mM EDTA with several changes for 18 h at 4° C. before storage. The modification of the mixture was tested in denatured polyacrylamide gels (BioRad Laboratories AB; Sundbyberg, SE), suitable for separation of peptides.
Native or modified synthetic peptides diluted in PBS pH 7.4 (20 leg/ml), in presence or absence of liposomes, were absorbed to microtiter plate wells (Nunc MaxiSorp, Nunc, Roskilde, Denmark) in an overnight incubation at 4° C. As a reference, one of the peptides (P6) was ran on each plate. After washing with PBS containing 0.05% Tween-20 (PBS-T) the coated plates were blocked with SuperBlock in TBS (Pierce, Rockford, Ill.) for 5 min at room temperature followed by an incubation of pooled human plasma, diluted 1/100 in TBS-0.05% Tween-20 (TBS-T) for 2 h at room temperature and then overnight at 4° C. After rinsing, deposition of auto-antibodies directed to the peptides were detected by using biotinylated rabbit anti-human IgG- or IgM-antibodies (Dako A/S, Glostrup, Denmark) appropriately diluted in TBS-T. After another incubation for 2 h at room temperature the plates were washed and the bound biotinylated antibodies were detected by alkaline phosphatase conjugated streptavidin (Sigma), incubated for 2 h at room temperature. The color reaction was developed by using phosphatase substrate kit (Pierce) and the absorbance at 405 nm was measured after Ih of incubation at room temperature. The absorbance values of the different peptides were divided with the absorbance value of P6 and compared.
Statistics
SPSS was used for the statistical analyses. The results are presented as median and range and as proportions when appropriate. Boxplot and scatterplots were used to illustrate the relationship between age and selected peptides among cases and corresponding controls. Corresponding graphs were also used to illustrate the relationship between age and selected peptides, cases and controls, respectively, below and above the median age (61 year) at baseline and separately for cases and controls below the median age. In cases and controls, separately, partial correlation coefficients, adjusted for age and sex, were computed between selected peptides and blood lipid levels and common carotid IMT. Age- and sex adjusted partial correlation coefficients were also computed between common carotid IMT and selected peptides in cases and controls below and over the median age. An independent sample t-test was used to assess normally distributed continuous variables and a Chi-square test for proportions between cases and controls. Non-parametric test (Mann-Whitney) was used to assess non-normally distributed continuous variables between cases and controls. All p-values are two-tailed.
TABLE C
Age- and sex adjusted correlation coefficient for different baseline
MDA peptides and common carotid artery intima-media thickness among
younger (49-61 years) and older (62-67 years) cases with myocardial
infarction and their corresponding controls matched for age, sex,
smoking and hypertension.
CASES plus CONTROLS
CASES plus CONTROLS
PEPTIDE
Aged 49-61 year, n = 116
Aged 62-67 year, n = 111
IGM
MDA 32
0.235t
−0.101
MDA 45
0.366$
−0.030
MDA 74
0.178
0.063
MDA 102
0.255$
−0.039
MDA 129
0.330$
−0.009
MDA 162
0.2451
0.001
MDA 210
0.254
0.013
MDA 240
0.284$
0.006
IGG
MDA 215
0.119
−0.059
p < 0.05;
$/x0.01 | The present invention relates to antibodies raised against fragments of apolipoprotein B, in particular defined peptides thereof, for immunization or therapeutic treatment of mammals, including humans, against ischemic cardiovascular diseases, using one or more of said antibodies. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/493,671, filed Jun. 6, 2011, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to mechanisms by which nacelle components of a turbofan gas turbine engine can be coupled and decoupled.
[0003] FIG. 1 schematically represents a high-bypass turbofan engine 10 of a type known in the art. The engine 10 is schematically represented as including a nacelle 12 and a core engine (module) 14 . A fan assembly 16 located in front of the core engine 14 includes a spinner nose 20 projecting forwardly from an array of fan blades 18 . The core engine 14 is schematically represented as including a high-pressure compressor 22 , a combustor 24 , a high-pressure turbine 26 and a low-pressure turbine 28 . A large portion of the air that enters the fan assembly 16 is bypassed to the rear of the engine 10 to generate additional engine thrust. The bypassed air passes through an annular-shaped bypass duct 30 between the nacelle 12 and an inner core cowl 36 of the core engine 14 , and exits the duct 30 through a fan exit nozzle 32 . The core cowl 36 defines the radially inward boundary of the bypass duct 30 , and provides an aft core cowl transition surface to a primary exhaust nozzle 38 that extends aftward from the core engine 14 .
[0004] The nacelle 12 is typically composed of three primary elements that define the external boundaries of the nacelle 12 : an inlet assembly 12 A, a fan cowl 12 B including a fan case that surrounds the fan blades 18 , and a thrust reverser assembly 12 C located aft of the fan cowl 12 B. The thrust reverser assembly 12 C comprises four primary components: a translating cowl 34 A mounted to the nacelle 12 , the inner core cowl 36 of the core engine 14 , a cascade 34 B schematically represented within the nacelle 12 , and a blocker door 34 C schematically represented as being pivotally deployed from a position radially inward from the cascade 34 B. The bypassed fan air flows between fan duct flow surfaces defined by the translating cowl 34 and the core cowl 36 before being exhausted through the fan exit nozzle 32 . The translating cowl 34 translates to expose the cascade 34 B and cause the blocker door 34 C to deploy and divert bypassed air through the exposed cascade 34 B.
[0005] In recent engine systems, the thrust reverser assembly 12 C has been configured to separate from the fan cowl 12 B and translate aft to allow access to the core cowl 36 and the core compartment of the core engine 14 . Such a configuration requires the ability to connect and disconnect a fixed structure of the thrust reverser assembly 12 C (which includes the cascade 34 B) at a fixed structure (generally, the fan case) surrounded by the fan cowl 12 B.
BRIEF DESCRIPTION OF THE INVENTION
[0006] The present invention provides a method and system suitable facilitating the connection and disconnection of a thrust reverser assembly to a fan case of a nacelle of a gas turbine engine. The invention is particularly well suited for use with a thrust reverser assembly comprising a fixed structure configured to be translated to couple and decouple the fixed structure from the fan case.
[0007] According to a first aspect of the invention, the clamping system comprises flanges associated with the fan case, flanges associated with the fixed structure of the thrust reverser assembly and adapted for simultaneous mating with the flanges of the fan case, and a plurality of over-center clamping mechanisms. A first of the over-center clamping mechanisms is mounted to the thrust reverser assembly and adapted to clamp a first of the flanges of the thrust reverser assembly with a first of the flanges of the fan case. A second of the over-center clamping mechanisms is mounted to the fan case and adapted to clamp a second of the flanges of the thrust reverser assembly with a second of the flanges of the fan case.
[0008] According to a second aspect of the invention, a method of coupling and decoupling a fan case and thrust reverser assembly entails operating a clamping system to simultaneously engage and disengage flanges associated with a fixed structure of the thrust reverser assembly and flanges associated with the fan case. The operating step comprises movement of a plurality of over-center clamping mechanisms to clamp together the flanges of the thrust reverser assembly and the fan case.
[0009] A technical effect of the invention is the ability of the clamping system to quickly and reliably connect and disconnect a thrust reverser assembly to a fan case of a gas turbine engine using multiple/redundant connections. The clamping system also offers the advantages of low weight, compactness, no conflicts with service line routing, ease of operation, and reduced risk for jams or improper seating due to friction.
[0010] Other aspects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 schematically represents a cross-sectional view of a high-bypass turbofan engine.
[0012] FIGS. 2 and 3 are isolated perspective and axial views, respectively, showing an assembly comprising portions of a fan case and a fixed structure of a thrust reverser assembly coupled together with a multi-segment clamping system of the present invention.
[0013] FIG. 4 is an isolated perspective view of the assembly of FIGS. 2 and 3 showing the portions of the fan case and fixed structure decoupled from each other through the operation of the multi-segment clamping system of the present invention.
[0014] FIG. 5 is a detailed side view of a portion of the multi-segment clamping system of FIG. 4 .
[0015] FIG. 6 is a detailed view of the multi-segment clamping system of FIG. 4 showing a cutout through which conduits can be routed through the assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIGS. 2 through 6 represent various views of an assembly 40 through which a fan case and thrust reverser assembly of a gas turbine engine can be quickly coupled and decoupled to allow the thrust reverser assembly to translate aft and away from the fan case, for example, on one or more slider tracks (not shown). The assembly 40 represented in FIGS. 2 through 6 can be installed in a high-bypass gas turbine engine 10 of the type represented in FIG. 1 . While the assembly 40 can be adapted for installation at various locations of the engine 10 , the assembly 40 is particularly intended to be installed between the fan cowl 12 B and thrust reverser assembly 12 C, for example, at a location of the nacelle 12 located axially between the high and low pressure compressor sections 22 and 24 of the engine 10 .
[0017] The assembly 40 is represented as including two ring-type components, a first of which will be referred to as the fan case 42 and the second will be referred to as a fixed structure 44 of a thrust reverser assembly. As known in the art, the fan case 42 is a static structure within the fan cowl 12 B that surrounds the fan blades 18 of the engine 10 , and the fixed structure 44 may include the cascade 34 B and other static parts of the thrust reverser assembly 12 C of the engine 10 . Accordingly, it should be understood that the ring-type components shown in the figures and identified as the fan case 42 and fixed structure 44 are only portions of, respectively, a fan case and thrust reverser assembly typically found in a high-bypass gas turbine engine of the type represented in FIG. 1 . In particular, the component identified as the fan case 42 may be a portion of the entire structure that forms a fan case within the nacelle 12 of the engine 10 , or a ring that is bolted or otherwise attached to a structure that together form a fan case of the engine 10 . Similarly, the component identified as the fixed structure 44 may be a portion of the entire structure that forms the fixed structure (including the cascade 34 B) of the thrust reverser assembly 12 C of the engine 10 , or a ring that is bolted or otherwise attached to a structure that together form the fixed structure of the thrust reverser assembly 12 C. However, for convenience, the components will simply be referred to as the fan case 42 and fixed structure 44 .
[0018] The assembly 40 is represented in FIGS. 2 through 6 as comprising a clamping system adapted to couple and decouple the fan case 42 and the fixed structure 44 to allow the thrust reverser assembly 12 C to translate aft and away from the fan case 42 . The clamping system is configured to provide a method for coupling and decoupling the fan case 42 and thrust reverser assembly 12 C by simultaneously engaging and disengaging flanges 48 and 50 associated with, respectively, the fan case 42 and the fixed structure 44 of the thrust reverser assembly 12 C. In particular, the clamping system comprises a plurality of over-center clamping mechanisms 52 , some of which are mounted to the fan case 42 and others to the fixed structure 44 . The coupling and decoupling method provided by the clamping system entails the movement of each clamping mechanism 52 to simultaneously clamp portions of the flanges 48 and 50 together, as well as simultaneously release the flanges 48 and 50 .
[0019] As represented in FIG. 5 , the flange portions 48 A and 50 A preferably project in radially outward directions of the engine 10 , so that the flange portions 48 A and 50 A lie in planes that are parallel to each other. As most readily evident from FIGS. 4 and 5 , the flanges 48 associated with the fan case 42 comprise multiple axially-offset flange portions 48 A that extend around different circumferential portions of the nacelle 12 . Similarly, the flanges 50 associated with the fixed structure 44 comprise multiple axially-offset flange portions 50 A that extend around different circumferential portions of the nacelle 12 . The flange portions 48 A of the fan case 42 and the flange portions 50 A of the fixed structure 44 are complementarily axially offset and circumferentially located so that each flange portion 48 A of the fan case 42 will mate with one of the flange portions 50 A of the fixed structure 44 . Each of the over-center clamping mechanisms 52 of the clamping system is also circumferentially and axially offset from each other, and dedicated to clamp one complementary pair of the flange portions 48 A and 50 A. Furthermore, each over-center clamping mechanism 52 is mounted to either the fixed structure 44 to clamp one of the flange portions 50 A of the fixed structure 44 with one of the flange portions 48 A of the fan case 42 , or to the fan case 42 to clamp one of the flange portions 50 A of the fixed structure 44 with one of the flange portions 48 A of the fan case 42 .
[0020] Each of the over-center clamping mechanisms 52 of the clamping system comprises a clamping segment 54 that extends over a circumferential portion of the nacelle 12 , a pivot link 56 at one circumferential end of the clamping segment 54 , and an over-center link 58 at an oppositely-disposed circumferential end of the clamping segment 54 . Because each clamping mechanism 52 is mounted to either the fan case 42 or the fixed structure 44 , each pair of pivot and over-center links 56 and 58 for each mechanism 52 is pivotably mounted to either the fan case 42 or the fixed structure 44 . As evident from FIGS. 2 , 3 and 4 , in the circumferential direction of the assembly 40 , the mechanisms 52 alternate between being mounted to the fan case 42 or to the fixed structure 44 . Furthermore, the circumferential ends of the mechanisms 52 overlap each other as a result of their pivot and over-center links 56 and 58 being axially aligned with one of the pivot or over-center links 56 and 58 of an adjacent mechanism 52 . The over-center link 58 cooperates with the pivot link 56 to induce an over-center toggle operation in the clamping segment 54 . Due to the pivoting movement of the pivot and over-center links 56 and 58 , the movement of the clamping segment 54 comprises both a radially outward travel and then a radially inward travel combined with a circumferential travel between a position of the mechanism 52 that clamps a pair of flange portions 48 A and 50 A together and a position of the mechanism 52 that releases the pair of flange portions 48 A and 50 A. As should be evident from FIGS. 2 through 6 , an operator can readily cause each mechanism 52 to move between these two extremes by grasping a handle 60 that protrudes in a circumferential direction from the segment 54 adjacent the over-center link 58 .
[0021] Those skilled in the art will appreciate that the configurations of the over-center clamping mechanisms 52 are based on the design of a Marman clamp, which is a well-know device for connecting pipe joints. However, the present invention uses a plurality of axially and circumferentially offset mechanisms 52 to achieve a large-diameter connection between the fan case 42 and the fixed structure 44 of the thrust reverser assembly 12 C. The multiple mechanisms 52 are not only convenient to operate, but also provide a level of redundancy, retaining a secure connection even in the event of a failure of one or more of the mechanisms 52 . An optimal number of mechanisms 52 will vary depending on the given application, though the use of two to eight mechanisms 52 is believed to be practical for many applications. The invention may further comprise means (not shown) for locking the handles 60 to secure the mechanisms 52 in the clamping position, as well as additional tensioning devices similar to latches.
[0022] As shown in FIGS. 2 through 4 and more readily seen in FIG. 6 , the assembly 40 can further comprise a cutout 62 through which conduits 64 of any type can be routed through the assembly 40 . A gas-tight seal (not shown) can be provided to minimize or prevent air flow losses through the assembly 40 . FIG. 6 further shows a pair of shear pins 66 located on either side of the cutout 62 to reinforce the structural strength of the assembly 40 in the vicinity of the cutout 62 .
[0023] While the invention has been described in terms of a specific embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the assembly 40 could differ in appearance and construction from the embodiment shown in the figures, the functions of each component of the assembly 40 could be performed by components of different construction but capable of a similar (though not necessarily equivalent) function, and various materials could be used in the construction of these components. Therefore, the scope of the invention is to be limited only by the following claims. | A method and system suitable facilitating the connection and disconnection of a thrust reverser assembly to a fan case of a nacelle of a gas turbine engine. The method and system entail operating a clamping system to simultaneously engage and disengage flanges associated with the fan case and flanges associated with the fixed structure of the thrust reverser assembly. The clamping system includes a plurality of over-center clamping mechanisms, each of which is movable to simultaneously clamp together complementary flanges of the thrust reverser assembly and the fan case. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] None
STATEMENT REGARDING FED SPONSORED R & D
[0002] None
BACKGROUND OF THE INVENTION
[0003] The use of water by the world's population for personal residential use as well as commercial and industrial uses of water is increasing. Regulations to control the quality of water returned to the environment have been instituted to limit the degree of environmental pollution. Due to the increasing use of water and regulations for controlling the quality of water returned to the environment, water treatment systems continue to grow in importance.
RELATED ART
[0004] Conventional wastewater treatment processes that treat municipal wastewater generally use processes that require a significant amount of time to complete. These time consuming processes include the physical process of settling where suspended solids float to the surface or settle to the bottom of a settling tank and the biological process where dissolved and colloidal solids are biodegraded by microorganisms and are converted to sludge and scum. Due to the long time duration of these processes, the tanks in which they occur must be sufficiently large to meet the water treatment production requirements. For example, for a facility that has a total production process time of 12 hours, and a production requirement of 100,000 gallons per day, the approximate aggregate tank capacity within the facility needs to be 50,000 gallons. However, a treatment process that has a total process time of 30 minutes can produce the same amount of treated water with a total approximate aggregate tank capacity of 2,100 gallons. Large facility requirements are costly in land use, construction and maintenance. It is therefore desirable to have a process for treating wastewater that has a process time that is short in duration.
[0005] The biological processes used by conventional wastewater treatment facilities require continuous aeration to provide the microorganisms which biodegrade the dissolved and suspended colloidal solids the air needed to sustain their life. The aeration of the large tanks involved requires costly installation and maintenance of large aeration and re-circulation pumps and substantial electrical power to operate. The aeration of large tanks also creates the production of offensive odors that must commonly be controlled. Controlling such odors requires the costly installation and maintenance of significant air handling mechanisms and air scrubbers which require substantial power to operate. Treatment processes which require aeration of large tanks therefore result in a high cost of construction, maintenance and operation. It is therefore desirable to have a process for treating wastewater which does not require aeration of large tanks to maintain living microorganisms.
[0006] Conventional wastewater treatment processes that treat municipal wastewater generally use some chemical processes such as chlorine to disinfect and otherwise treat the water. Chlorine is commonly used in the form of chlorine gas which is very hazardous to store and handle. It is further desirable to have a process that does not require chlorine gas additives to disinfect.
DESCRIPTION OF THE PRIOR ART
[0007] U.S. Pat. No. 4,179,347 describes a continuous system for disinfecting water. A wastewater stream is passed into an electrolytic cell open to the atmosphere and between a series of electrically charged parallel electrode plates. A controlled amount of electrolyte such as sodium chloride is added to the wastewater stream before it passes through the electrolytic cell. A portion of the treated water from the electrolytic cell is recycled and re-injected into the influent stream.
[0008] U.S. Pat. No. 5,948,273 illustrates a water purification process which comprises applying electrical energy to water to be treated in a treatment chamber having a cathode and an anode opposing each other. The anode and/or the water in the vicinity of the anode is vibrated and debris inside and outside the chamber is removed.
[0009] Of particular relevance are the following patents to Mehl because of the use of electrolysis in their system.
[0010] U.S. Pat. No. 3,340,175 to C. W. Mehl discloses an apparatus for purifying water wherein the wastewater is electrolytically treated by moving sewage between a series of plates located from 0.4 to 0.7 inches from each other while a rectified one-half wave ten to sixty cycles per second alternating current having a small reverse current is applied to the first and last plates of the series. The inventive concept does not use a series of plates and does not employ alternating current.
[0011] U.S. Pat. No. 3,523,891 to R. C. Mehl illustrates a two-stage sewage treatment process including a first electrolytic cell for producing a metal hydroxide floc on electrolysis and an ozone unit for bubbling ozone upwardly through the cell and floating the floc on top of the fluid. A vacuum blower communicates with the cell for removing the floc and the entrapped solids. A second stage cell having a pair of horizontally mounted electrodes for further producing a metal hydroxide floc may be included for further removing suspended solids. In contrast to this disclosure, the inventive method at hand uses a first stage electrochemical process for producing metal hydroxide floc and a second stage electrochemical process for oxidation. Said first stage and second stage electrochemical processes are separated by a process to remove solids formed and coagulated in the first electrochemical process. The inventive concept does not have a multiple of rectangular electrode plates as will be described below.
[0012] There is also known the systems provided by “Hydroxyl Systems’ of B.C. Canada. One such Hydroxyl system is merely designed to be used in marine applications. This system consists of four major components such as (a) a primary screening, (b) primary solids separation/oxidation tank, (c) secondary oxidation/disinfection tank and (d) controls and oxidant generation equipment. The process includes primary solids separation, the removal of suspended solids, oil and grease as well as Biochemical-Oxygen-Demand (BOD) reduction. The Hydroxyl systems use various methods of oxidation. The marine system uses a separate oxidant generator which then feeds into influent. Hydroxyl hazardous waste systems show separate 0 3 and H 2 0 2 generators that feed directly into the influent stream. These latter two systems, marine and hazardous, appear to be differentiated from the inventive concept in that they use separate generators for oxidation rather than oxidizing the stream directly. Hydroxyl wastewater treatment systems utilize biological reactors. None of the above references teach the use of an electrochemical process for the treatment of wastewater similar to that of the present invention.
SUMMARY OF THE INVENTION
[0013] The wastewater treatment stages are as follows:
[0014] Stage one: coagulation, absorption and conversion of soluble compounds to insoluble compounds. By means of an electrolytic reactor cell, granular bipolar electrodes are decomposed to form metal hydroxide in solution. The granular electrodes used in the reactor bed are bipolar in nature and are equally potentialized to maximize their consumption. Electrode materials are selected and blended for use in the reactor bed in proportion to the expected reactions required to coagulate the colloidal solids.
[0015] Stage two: A solids separation process is used to separate solids coagulated in stage one from the fluent. Solids separation can be accomplished using a continuous backwash sand filter, Dissolved Air Flotation (DAF) system or other conventional processes to effect separation of the solids.
[0016] Stage three: The fluent having solids substantially removed in stage two, then passes through a third stage electrochemical reactor cell. The granular electrodes in this cell are stable, that is, non-corrosive. The purpose of the reactions within this cell is to produce oxidative species that react with remaining dissolved solids. These oxidative species consist of nascent oxygen, ozone and peroxide in varying proportions. Chlorine is also formed in proportion to the chlorine salts present in the waste stream.
[0017] Stage four: A conventional polishing filter is used to remove particles as small as one micron. The particles filtered in this stage consist of debris generated by the oxidation reactions in stage three.
[0018] Stage five: Injected ozone in this stage and contact with ultra violet light accomplish a sterilization. Final effluent is re-circulated within the reservoir to maintain a high rate pathogen kill.
OBJECTS OF THE INVENTION
[0019] It is an object of the invention to provide a new electrochemical process and apparatus which can be realized in a relatively small floor surface area.
[0020] It is another object of the present invention to provide a new electrochemical process and apparatus which may be easily and effectively manufactured and marketed being fabricated from readily available materials.
[0021] It is a further object of the present invention to provide a new electrochemical method and apparatus which consumes a relatively small amount of power.
[0022] Still another object of the invention is to provide a new electrochemical process and apparatus which requires minimal maintenance over its entire useful life.
[0023] It is also an object of the present invention to provide a new liquid reactor cell for causing impurities within a fluid to coagulate and form larger particles which then may be more easily separated by subsequent separation processes.
[0024] It is a further object of the present invention to provide a new liquid reactor cell which is of a durable and reliable construction.
[0025] It is another object of the present invention to provide a new liquid reactor cell which operates effectively under varying fluid flow conditions.
[0026] It is another object of the present invention to provide a new liquid reactor cell which automatically replenishes electrodes consumed in the reactor cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] [0027]FIG. 1 is a flow diagram of the overall process;
[0028] [0028]FIG. 2 shows the structure of an electrolytic reactor cell;
[0029] [0029]FIG. 3 shows the mixed media in the reactor in an enlarged view;
[0030] [0030]FIG. 4 shows a schematic of how the ratio weir operates.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In this specification, the following nomenclature will be used with reference to the wastewater or sewage that is being treated. An ‘Influent”, whether it is primary or secondary, is the fluid to be treated as it enters any of the treatment system components. ‘Effluent” is the fluid as it exits any of the components. “Fluent” is the fluid that is within any one of the components. In this respect, in FIG. 1 the numeral 1 is the primary influent that enters the headworks 2 to be treated therein by removing solids. The headworks grinds, washes, de-waters and discharges the solids from the fluent within the headworks 2 . Screens within the headworks 2 only allow solids which are less than a maximum size to pass through the headworks 2 and to flow downstream to pump 4 by way of a feed valve 3 . The headworks 2 are commonly available, such as the ‘Auger Monster’, manufactured by JWC Environmental headquartered in Costa Mesa, Calif.
[0032] For treating wastewater having a high sand and grit content, it may be desirable to include a degritter after the headworks 2 to capture sand and grit not removed by the headworks 2 . Sand and grit can create accelerated wear in system components such as pumps and valves. Sand and grit will also tend to settle and collect in areas where the fluent flow slows such as in a primary reservoir. Degritters are commonly available such as those manufactured by Grande, Novae and Associates, Inc. having headquarters in Montreal, Canada.
[0033] Pump 4 is a centrifugal pump having a variable speed drive. The variable speed drive allows for control of the rate of flow of the fluent as measured and determined by the flow meter 5 . Centrifugal pumps are desirable as they are simple to maintain and repair. Pump 4 is commonly available, such as the model 3080.211/311 manufactured by ITT Flygt headquartered in Stockholm Sweden.
[0034] Flow meter 5 measures the rate of flow of the influent. A magnetic flow meter such as those manufactured by Krone or Isco can be used. The flow meter 5 can be located near the influent or the effluent point of pump 4 depending on which is more convenient for installation. However, it needs to be located such that it receives influent having negligible turbulence so as not to cause inaccurate flow measurements. This location will generally be at a minimum distance from pump 4 equal to several multiples of the interconnecting pipe's diameter and will generally be specified by the meter's manufacturer.
[0035] The fluent is moved by the pump 4 to a primary reservoir 6 . This reservoir 6 is used to slow the influent for analysis. Sensor probes are used to measure the control parameters such as the pH and conductivity. The primary reservoir 6 also serves to maintain the energy required to move the fluent through the balance of the system. This can be accomplished by either constructing the primary reservoir as a sealed tank to maintain the pressure generated by pump 4 or to construct the primary reservoir as an open tank and to elevate said tank to maintain gravitational energy generated by the Pump 4 .
[0036] The fluent flows from the primary reservoir 6 to a primary reactor 7 . Primary reactor 7 is comprised of one or more of vertically oriented reactor cells 29 . The reactor cells are shown in more detail in FIG. 2. Said vertical orientation refers to the vertical and upward flow of fluent through the cells. Each primary or electrolytic reactor cell 29 receives fluent from the primary reservoir 6 at the cell 29 bottom. The fluent travels upwardly through the electrolyzed mixed media bed 32 that consists of expendable blended bipolar granular electrodes 34 and non-conductive granular electrode spacers 33 of similar size and densities. The non-conductive granular electrode spacers 33 serve to provide some separation between the bipolar granular electrodes 34 to limit electrical shorting between the electrodes within the cell 29 . The interior of the cell body is stacked with porous spheres 39 designed to trap oxygen bubbles and to stabilize the mixed media 32 during fluidization. As the fluent travels upward through the electrolyzed mixed media 32 it becomes fluidized. This action prevents the system from clogging with debris and helps to move the mixed media 32 within the cell 29 for uniform decomposition. The bipolar granular electrodes 34 consist of conductive and potentially non-conductive materials that are co-extruded and cut into granules for use in the cells 29 of reactor 7 . For municipal wastewater treatment, the conductive material consists of aluminum and a lesser component of iron, but can be varied in composition to suit the specific contaminants being treated. During the electrolytic process the conductive component of the bipolar electrodes 34 breaks down (decomposes) to form metal hydroxide. For the non-conductive component of the electrode, carbon can be utilized to absorb volatile organic compounds (VOC). The carbon is consumed by abrasion. The rate of consumption is adjusted to be similar to that of the conductive component by varying the hardness of the carbon. Similarly, the non-conductive spacers 33 can consist of carbon to additionally absorb volatile organic compounds (VOC). The carbon comprising the non-conductive spacers 33 is consumed by abrasion. The rate of consumption is adjusted to be similar to that of the bipolar electrodes 34 by varying the hardness of the carbon. Metal hydroxide, carbon and other solids are later removed from the fluent in solids separator 14 . There is a drain valve 8 below the primary reactor 7 to drain fluids from the reactor whenever necessary. Such fluids are returned to the headworks 2 .
[0037] To produce the electrolytic process, an electrical current is applied to flow between stationary contacts 30 and 31 situated at opposite ends of the of the primary reactor cell 29 in FIG. 2. The stationary contacts 30 and 31 are in contact with the fluidized media bed 32 . The electrical current produces an electrolytic reaction that decomposes the conductive component of the bipolar granular electrodes 34 into metal hydroxide. Current to the primary reactor 7 is adjusted by the Programmable Logic Controller (PLC) 50 to optimize the production of metal hydroxide through the decomposition of the bipolar electrodes 34 . The metal hydroxide produced in the primary reactor 7 serves as a flocculating agent that coagulates the suspended and colloidal solids thereby making it possible to remove by subsequent filtration or other separation processes.
[0038] Polarity of the stationary contacts 30 and 31 is periodically reversed to aid in the cleansing of the stationary contacts. Polarities to the bipolar granular electrodes 34 in the media bed 32 are reversed automatically as the position of these loose electrodes change due the action within the fluidized bed.
[0039] Periodically, the cell, or cells if more than one, are vibrated to loosen the media and abrasively remove deposits on the stationary contacts 30 and 31 . This action also keeps the media bed from clogging with debris. Furthermore, the vibration abrasively decomposes the carbon component of the bipolar granular electrode 34 and the carbon based non-conductive spacers 33 . Vibration may be accomplished by several means such as pneumatic, hydraulic, ultrasound or electromagnetic. To this end in FIG. 2 there is shown a solid bass 46 . On this solid base the shell 29 of the primary reactor is supported on rubber blocks 41 and 42 . The vibrator 40 is schematically shown at 40 . It is supported on a vertical block 44 having clamps 45 mounted thereon where said clamps surround the shell 29 . Therefore, if the vibrator 40 is operated, the shell 29 of the primary reactor can follow the vibratory movements because of the elastic mounts 41 and 42 .
[0040] Granular mixed media is automatically replaced in the cell, or cells if more than one, as it is consumed. A hopper 35 is attached at the top of each cell by way of a flexible coupling 36 . During the vibration cycle mixed media 32 is moved into the cell 29 to replace the media consumed during the electrolytic process.
[0041] Effluent from the primary reactor 7 passes to the secondary receptor 12 through a ratio weir 9 . The ratio weir 9 as shown in FIG. 4 is constructed as a trough 51 which has an adjustable mechanism 53 to split the flow of influent into two portions of effluent flows having an adjustable ratio of proportions. Influent 56 into the ratio weir 9 travels through the trough 51 towards the weir 55 . As the influent 56 moves through the trough 51 , most of the turbulence in the fluent subsides and the flow becomes relatively laminar. The adjustable divider 53 splits the fluent flow as it passes over the weir 55 . The resultant two fluent streams spill over weir 55 and encounter the opposing gradient dividers 57 and 58 and flow towards their respective outlets 59 and 60 . Gradient dividers 57 and 58 rigidly meet at their top most surfaces to which a hinge 54 connects the adjustable divider 53 . Adjustable divider 53 can pivot about hinge 54 and move from side to side to vary the ratio of portions of effluent flows 59 and 60 . Ratio weir 9 sends a portion of the fluent from the primary reactor 7 (5% to 25%) to the concentration reactor 10 . Concentration reactor 10 has a reactor cell identical in construction to the primary reactor 7 . Electrical current to the concentration reactor 10 is adjusted by the PLC 50 to highly treat the fluent to create an excess of metal hydroxide and oxidative species. Alternatively to simplify the control and electrical power equipment, the electrical current to the concentration reactor 10 can be a set ratio of the current to the primary reactor 7 . Fluent from the concentration reactor 10 is returned to the headworks 2 where its excess metal hydroxides and oxidative species serve to precondition or pre-treat the primary influent 1 . Pre-treating helps to improve the primary reactor's 7 efficiency allowing for an increase of fluent flow through the system by initiating the reduction and flocculation of dissolved and suspended particles in the fluent stream prior to entering the primary reactor 7 . Odor is significantly reduced by oxidation resulting from the highly treated fluent delivered from the concentration reactor 10 . A drain valve 25 is included in a line to drain the concentration reactor completely of fluent and return the fluent back to the headworks if so desired.
[0042] The major portion of effluent from the primary reactor 7 (75% to 95%) passes through the ratio weir 9 to the secondary receptor 12 . The secondary receptor 12 contains sensors for the measurement of control parameters pH, total suspended solids (TSS) and conductivity. The secondary receptor 12 is of a size that results in an average fluent dwell time of several minutes within the receptor 12 . This several minute dwell time provides additional reaction time for flocculation and oxidation of suspended and dissolved solids before entering the solids separator 14 . A shutoff valve 13 has been interposed between the secondary receptor 12 and the solids separator 14 .
[0043] Effluent from the secondary receptor 12 flows to a solids separator 14 . Solids separator 14 can be of any process which effectively separates the coagulated solids from the fluent. Two preferable processes for separating solids are a continuous backwash gravity sand filter such as those manufactured by Applied Process Technology, Inc., having its headquarters in Conroe, Tex., or a Dissolved Air Flotation (DAF) system such as those manufactured by Pan American Environmental, having headquarters in Schaumburg, Ill. In a continuous backwash gravity filter the influent to the sand filter enters at the top and gravitates down through layers of increasingly finer sand. Solids captured in the filter beds are drawn downward with the sand into an airlift pump. The turbulent, upward flow in the airlift provides a scrubbing action that effectively separates the sand and the solids before discharging into a filter wash box. The regenerated sand is returned to the top of the filter and the reject solids, now in the form of sludge are sent to sludge removal 15 for disposal.
[0044] In a DAF system, fluent which has been saturated under pressure with air, is released into the bottom of a DAF tank. As air-saturated fluent enters the tank microscopic bubbles of air are released due to a drop in pressure. The microscopic air bubbles attach themselves to solids in the fluent and cause the solids to float to the top of the DAF tank. Skimmers then remove the floating solids which are now in the form of sludge which is sent to sludge removal 15 for disposal.
[0045] Clean fluent from the solids separator 14 is sent to the second stage oxidation reactor 16 . The second stage oxidation reactor 16 consists of one or more electrolytic cells 29 . These cells are substantially similar in construction as the cell in primary reactor 7 with the exception that the mixed media 32 consists of stable non-corrosive conductive materials and non-abrading non-conductive materials. Therefore the mixed media 32 used in oxidation reactor 16 does not decompose. Accordingly, the cells 29 (FIG. 2) in the oxidation reactor 16 are not equipped with hoppers for replenishment as none of the media is consumed. Work performed by the action of electrolysis is used to generate oxidative species such as nascent oxygen, ozone and peroxides. Electrical current to the oxidation reactor is adjusted by the PLC 50 to optimize the production of the oxidative species. The accelerated oxidation which takes place in the oxidation reactor 16 further reduces total dissolved solids (TDS), biological oxygen demand (BOD), and chemical oxygen demand (COD) and other contaminants that lend themselves to oxidation reactions. A byproduct of electrolytic process in the oxidation reactor 16 is the production of chlorine from the salts present in the fluent. If additional chlorine is required to maintain required residual levels, a saline brine solution can be added to the fluent prior to the primary reactor 7 . The addition of salt to the system will also increase the overall efficiency of the system by improving the conductivity within the reactors 7 , 12 and 16 .
[0046] Effluent from the oxidation reactor 10 flows to the effluent reservoir 19 . Effluent reservoir 19 is an open tank reservoir having a shutoff valve 20 to allow or restrict discharge of fluent. Effluent reservoir 19 is also used to slow the fluent for analysis. Sensor probes are used to measure the control parameters of pH, dissolved oxygen (DO), TSS and chlorine that are measured to determine if the fluent meets regulation for discharge. If the fluent is determined to meet regulations, the fluent has been sufficiently treated and the shutoff valve 20 remains open thereby discharging the fluent. Sufficiently treated effluent that is discharged from the effluent reservoir 19 may optionally be further treated by means of ultraviolet light 21 and a polish filter 22 . If the fluent in effluent reservoir 19 is determined not to meet regulations, the fluent is not sufficiently treated and the shutoff valve 20 is closed. When shutoff valve 20 is closed the fluent overflows through the effluent overflow system in combination with the effluent reservoir 19 and is returned to the headworks 2 for reprocessing. The effluent reservoir can be completely drained into a return line by opening the drain valve 24 if so required.
[0047] Sludge removal 16 receives discharged sludge from solids separator 14 . Sludge removal can be accomplished by a variety of systems commonly used for sludge removal such as the use of a sludge press, belt press, centrifuge or filter press to first remove much of the yet present water in the sludge resulting in a de-watered sludge. The wastewater extracted by these processes is returned by the solids separator 14 to the headworks 2 for treatment. The de-watered sludge can then be removed by truck, such as a dump truck. Alternatively, the sludge can be dumped directly into a tanker truck and removed without de-watering.
[0048] System control is provided by programmable logic controller (PLC) 50 which receives operator input and control parameter data from sensors and meters and controls the system operation based upon the operator input and control parameter data. PLC 50 is programmed to provide for startup sequences, shutdown sequences and the running of the wastewater treatment system. Two options for startup and shutdown sequences are described below. The first option is for systems which do not include a return valve 18 and feed valve 3 . The second option is for systems that have a return valve 18 and a feed valve 3 . While the addition of a return valve 18 and a feed valve 3 results in additional costs, these valves allow the system to operate a cleaning cycle whereby the PLC 50 shuts off fluent flow from the headworks 2 and provides a closed fluent loop by opening the return valve 18 and closing the feed valve 3 . This closed fluent loop enables the system to continually treat and cycle the fluent throughout the closed system.
[0049] Option 1 system start up is accomplished by the PLC 50 performing the following steps:
[0050] 1) Close shutoff valve 20 ;
[0051] 2) Close shutoff valve 13 ;
[0052] 3) Close drain valves 8 , 11 , 17 , 24 , 25 ;
[0053] 4) Start pump 4 at preset flow;
[0054] 5) Check if the fluent in the primary reactor 7 and the concentration reactor 10 are at sufficient levels. If so then proceed to step 6 ;
[0055] 6) Turn on the current in the primary reactor 7 and the concentration reactor 10 to a preset value;
[0056] 7) Check to see if the pH of the fluent entering the ratio weir 9 is within a preset range for a preset time. If so proceed to step 8 ;
[0057] 8) Open shutoff valve 13 ;
[0058] 9) Check to see if the fluent in oxidation reactor 16 is at a sufficient level. If so proceed to step 10 ;
[0059] 10) Turn on current to oxidation reactor 16 to a preset value;
[0060] 11) Check to see if the pH, CL, TSS and DO levels of the fluent in the effluent reservoir 19 meet requirements for discharge for a preset time. If so proceed to step 12 ;
[0061] 12) Open shutoff valve 20 .
[0062] Option 1 system shutdown is accomplished by the PLC 50 performing the following steps:
[0063] 1) Close shutoff valve 20 ;
[0064] 2) Turn off current to the primary reactor 7 , concentration reactor 10 and oxidation reactor 16 ;
[0065] 3) Turn off the pump 4 ;
[0066] 4) Open the drain valves 8 , 11 , 17 , 24 , 25 .
[0067] Option 2 system start up is accomplished by the PLC 50 performing the following steps:
[0068] 1) Close shutoff valve 20 ;
[0069] 2) Close shutoff valve 13 ;
[0070] 3) Close return valve 18 ;
[0071] 4) Close drain valves 8 , 11 , 17 , 24 , 25 ;
[0072] 5) Open feed valve 3 ;
[0073] 6) Start pump 4 at preset flow;
[0074] 7) Check if the fluent in the primary reactor 7 and the concentration reactor 10 are at sufficient levels. If so then proceed to step 8 ;
[0075] 8) Turn on the current in the primary reactor 7 and the concentration reactor 10 to a preset value;
[0076] 9) Check to see if the pH of the fluent entering the ratio weir 9 is within a preset range for a preset time. If so proceed to step 10 ;
[0077] 10) Open shutoff valve 13 ;
[0078] 11) Check to see if the fluent in oxidation reactor 16 is at a sufficient level. If so proceed to step 12 ;
[0079] 12) Turn on current to oxidation reactor 16 to a preset value;
[0080] 13) Check to see if the pH, CL, TSS and DO levels of the fluent in the effluent reservoir 19 meet requirements for discharge for a preset time. If so proceed to step 14 ;
[0081] 14) Open shutoff valve 20 .
[0082] Option 2 system shutdown is accomplished by the PLC 50 performing the following steps:
[0083] 1) Close shutoff valve 20 ;
[0084] 2) Open return valve 18 ;
[0085] 3) Close feed valve 3 ;
[0086] 4) Run pump 4 at a preset flow;
[0087] 5) Set the currents in the primary reactor 7 , concentration reactor 10 and oxidation reactor 16 to preset values;
[0088] 6) Operate the system for an operator settable time period;
[0089] 7) Turn off current to the primary reactor 7 , concentration reactor 10 and oxidation reactor 16 ;
[0090] 8) Turn off the pump 4 ;
[0091] 9) Open the drain valves 8 , 11 , 17 , 24 , 25 .
[0092] The above series of steps also serve as a cleaning cycle for the system.
[0093] Running the system is accomplished by the PLC 50 continually performing the following steps:
[0094] 1) Adjust the pump 4 speed to maintain a desired primary influent level or to a preset flow;
[0095] 2) Adjust the current in the primary reactor 7 and concentration reactor 10 as a function of the flow rate and an operator entered pH set point for the fluent in the secondary receptor 12 ;
[0096] 3) Adjust the current in the oxidation reactor 16 as a function of the flow rate and an operator entered DO set point for the fluent in the effluent reservoir 19 ;
[0097] 4) Check to see if the pH, CL, TSS and DO levels of the fluent in the effluent reservoir 19 meet requirements for discharge. If the requirements are not met close shutoff valve 20 . If the requirements are met open shutoff valve 20 after a preset time delay if it is closed;
[0098] 5) Check to see if the pH level in the secondary receptor 12 is within an operator selected range. If it is not, begin the startup sequence or shutdown sequence based on an operator selectable value. If it is within the selected range proceed to step 6 ;
[0099] 6) Vibrate the reactors 7 , 10 and 16 based on an operator selectable time cycle for an operator selectable time duration.
[0100] In addition to the startup sequences, shutdown sequences and running of the wastewater treatment system, the PLC 50 can optionally control free CL levels in the final effluent and provide air injection to the primary reactor and concentration reactor.
[0101] Controlling the free CL level is accomplished by the PLC 50 continually performing the following steps:
[0102] 1) Check the free CL level of the fluent in the effluent reservoir 19 and the conductivity of the fluent in the primary reservoir 6 ;
[0103] 2) Adjust the brine feed to the fluent as a function of the fluent flow, the conductivity of the fluent in the primary reservoir 6 , the CL level in the effluent reservoir 19 and an operator entered set point for the CL level for the fluent in the effluent reservoir 19 .
[0104] Some systems may optionally include a mechanism to periodically inject air into the base of the primary reactor 7 and concentration reactor 10 . The resulting air flow though the reactor and media bed will serve to help remove debris in the reactor and media bed.
[0105] The control sequence for injecting air in the primary reactor 7 and concentration reactor 10 is accomplished by the PLC 50 performing the following steps:
[0106] 1) After an operator entered time delay from the start of the vibration step (which is step 6 of the sequence for running the system) open the air feed valve to inject air into the base of the primary reactor 7 and concentration reactor 10 ;
[0107] 2) After an operator entered time delay from the opening of the air feed valve, close the air feed valve.
[0108] The present invention can be used in conjunction with conventional wastewater treatment methods to increase capacity, reduce odor and provide a final stage for oxidation and disinfectant. Given the teachings of this invention, its application to conventional treatment systems will be apparent to those skilled in the art. For example, a conventional treatment system could utilize a primary reactor to treat fluent within a conventional physical settling tank or to pre-treat influent prior to a conventional physical settling tank. This would advantageously reduce odor and accelerate the settling action in the tank by providing oxidation and flocculating agents. In this configuration, the primary reactor would be connected to the settling tank or a holding tank situated prior to the settling tank. A circulation pump would circulate fluent from the settling tank or holding tank through the primary reactor. Furthermore, this method of treatment for use in a conventional treatment method could also include a ratio weir and concentration reactor, where said ratio weir directs the major portion of the effluent from the primary reactor to the settling tank or holding tank and directs the smaller portion to the concentration reactor. The effluent from the concentration reactor is then sent to the headworks thereby providing odor control and beginning a flocculation process within the headworks. All of the above can be accomplished without departing from the scope of the invention. | The invention is directed to a method of purifying water and wastewater as a fluent coming from industrial plants, municipal sewage systems, reservoirs and other water supplies and residential community and commercial water and sewage supplies and systems. The method includes the steps of running the wastewater as a fluent into a headworks where some preliminary treatment takes place. From there the fluent is passed into a primary reservoir. The fluent in the primary reservoir is analyzed as to certain control parameters such as pH and conductivity. Thereafter the fluent flows into a primary reactor having a plurality of electrolytic cells therein. While in that reactor the fluent is subjected to electrolytic reactions. The effluent from the primary reactor passes through a ratio weir into a secondary receptor. The secondary receptor contains sensors for the measurement of control parameters such as pH, (total suspended solids) TSS and chlorine. Thereafter, the fluent is passed to a filtering device. The filtered fluent then flows through an oxidation reactor. The overall purification system can be termed an electrochemical system. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to electroacoustic transducers employed in sonar systems, and more particularly to an electroacoustic transducer capable of accommodating multiple sonar beams.
2. Description of the Prior Art
Sonar systems utilize narrow beams of sound energy projected in certain desired directions from a marine vehicle, and receive reflected energy from these directions, as described, for example, in U.S. Pat. No. 3,257,638 for Doppler Navigation Systems, issued to Jack Kritz and Seymour D. Lerner in 1966. Conventionally, these beams are produced by vibrating piezoelectric discs with diameters that are large compared to the wavelength of the soundwave propagated or to be received. When multiple beams are utilized, the transducer assembly must be enlarged to accommodate the multiplicity of necessary elements. Multiple beam transducers of the prior art create installation difficulties, particularly on small ships, and provoke increased installation costs due to larger gate valves and stronger required structural supports. Thus, there is a need for relatively compact multiple beam transducers that will facilitate installation and mitigate attendant costs.
SUMMARY OF THE INVENTION
In accordance with the principles of the present invention, plane waves incident on an acoustic lens from a particular direction are directed to a focal region in the focal plane of the lens. An electroacoustic transducer constructed over a spherical shell segment centered at a point in the focal region provides a large surface for intercepting substantially all the coustic energy directed towards the focal region. During transmission, this electroacoustic transducer radiates spherical waves as though the transducer's associated focal region were the source. Such a spherical wave is transformed by the acoustic lens to a plane wave in the direction corresponding to the focal region from which the spherical wave appears to have originated.
In one preferred embodiment, the lens is doubly concave, solid polystyrene, bonded to an inner medium of silicone rubber. Three piezoelectric crystal transducers, each of which is 15 degrees off the central lens axis, are placed to receive or transmit beams. Interposed between each crystal and the inner medium of silicone rubber, is a metallic window followed by a plastic matching section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a doubly concave acoustic lens and associated spherical shell segment electroacoustic transducer, with a superposed ray diagram illustrating the focusing action of the lens.
FIG. 2 is a cross sectional view of a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention describes a means of constructing a multiple beam transducer that uses a single aperture in the form of an acoustic lens which provides the required aperture to wavelength ratio. A ray diagram depicting the focusing action of an acoustic lens is shown in FIG. 1. Parallel rays of an incident plane wave 10, propagating in the water mdium 11, impinge on the acoustic lens 12. To focus an incident plane wave, the lens is chosen doubly concave and constructed of a medium wherein the sound velocity is greater than the sound velocity in the water and the other adjacent medium 13. The focusing action results from the beam's being first bent away from the normal to the surface of the lower refractive index lens as it enters the lens, and then upon emergence from the lens, being bent towards the normal. Accordingly, incident plane sound wave 10 is focused to point 14 by the lens thus constructed. Conversely, a point source at 14 illuminating the lens with a sound wave will cause the projection of a plane wave depicted by the parallel rays 10. Characteristic of a lens constructed in this fashion is a unique correspondence between the direction of incidence of a plane wave, and the associated focal point in the focal plane of the lens. Simply, collimated beams incident from different directions have different focal points. For example, the plane wave incident from direction 15 will be focused at point 16. Thus, a multiplicity of such focal points lie in the focal plane, each of which can define a different beam direction for reception or projection of sound waves. A multiplicity of small electroacoustic transducers placed at different focal points can then be used to transmit and receive sound beams such that the beam width is characterized by the lens diameter.
A major deterrent to the implementation of this arrangement is the inability of the small transducers to operate at significant power levels. The sound intensity (watts per unit area) in medium 13 in the vicinity of the transducer is intense because of the small transducer surface area, causing cavitation and disruption of the medium. In addition, the heat dissipation produced by transducer losses is confined to the small transducer surface, causing high temperatures to be generated if significant electrical power is supplied. In this invention, larger transducers having significant surface area are employed, and are placed forward of the focal points. An electroacoustic transducer 17, is shaped in the form of a segment of a spherical shell, the radius of which is at the desired focal point. All rays impinging on 17 are in phase at the surface, since all surface elements are the same distance from the focal point by virtue of its spherical shape. All the acoustic energy received by lens 12 is thus available for conversion to electrical energy by the transducer. Conversely, when acting as a transmitter, the transducer radiates spherical waves as though the focal point 14 were the source. A further advantage obtained by this arrangement is that small changes in the position of the focal point do not cause drastic changes in the performance, since all rays are still encompassed by the transducer with only small out of phase interference. With small transducer elements directly at the focal point, small changes in focal point location can cause large changes in the captured energy. A further advantage is realized in the depth of the transducer being reduced, since the distance in medium 13 behind the lens need not extend to the focal plane.
A typical design embodying this invention is shown in FIG. 2. A solid lens 18, of cross linked polystyrene, 3.375 inches in diameter, 0.187 inches center thickness, with external radius of 13.3 inches, and internal radius of 3.74 inches is in contact with water on its outer surface and bonded on its inner surface to a medium 19, of silicone rubber. The arrangement shown provides for three transmitting or receiving beams each 15 degrees off the len's central axis. The low sound speed in rubber produces a short focal length 20, of 5.52 inches, thus further diminishing the assembly depth. The subtended angle 21 is 37 degrees. Three spherical shell segment piezoelectric crystals, one of which is crystal 22, centered at focal points, one of which is focal point 23, of outer radius 1.587 inches, and of such thickness that they resonate at 400 kHz, are bonded to a metal support 24. Interposed between each crystal and the silicone rubber medium is first, a metallic window 25, followed by a plastic matching section 26. The metallic window is an aluminum spherical shell segment with thickness an integral multiple of a half wave length, in this case 0.311 inches. The window provides both structural strength and heat transport for the crystals, and is essentially transparent at the operating frequency. The transparency, that is, the negligible effect upon the transmission of waves follows from the standard sound transmission coefficient formula for waves traversing two boundaries (see, for example, Fundamentals of Acoustics, page 149 to 153, by Kinsler and Frey, Wiley, 1950). The matching section 26, is also a spherical shell segment, with thickness equal to an odd multiple of a quarter wavelength, in this embodiment a quarter wavelength, 0.065 inches. The matching section provides favorable electrical characteristics when measured at the electrical terminals of the crystals by transforming the low acoustic impedance of the rubber to a higher value for presentation to the crystals. Essentially, two purposes are served by the matching section: it broadens bandwidth, and increases efficiency of the transducer (see, The Effect of Backing and Matching on the Performance of Piezoelectric Ceramic Transducers, by George Kossoff, IEEE Transactions on Sonics and Ultrasonics, Volume SU-13, No. 1, March 1966).
While the invention has been described in its preferred embodiments, it is to be understood that the words which have been used are words of description rather than limitation and that changes may be made within the purview of the appended claims without departing from the true scope and spirit of the invention in its broader aspects. | A compact apparatus for transmitting and receiving multiple sonar beams utilizes an acoustic lens to direct plane waves incident in desired directions to electroacoustic transducers positioned on spherical shell segments centered in the focal regions of the lens associated with the incident beams. The electroacoustic transducers transmit spherical waves that are transformed by the acoustic lens to plane waves emergent in the desired directions. | 6 |
This application is a divisional of application Ser. No. 09/052,403, filed Mar. 31, 1998, and is related to application Ser. No. 09/052,538, filed Mar. 31, 1998, entitled "Process for Building Borderless bitline, Wordline and DRAM Structure and Resulting Structure".
FIELD OF THE INVENTION
This invention relates generally to DRAM cell design using transistors and semiconductor interconnection techniques, and more particularly to a conductive wordline for a DRAM cell and a method of making the same wherein the bitline contact is borderless to the wordline which is especially useful in folded-bitline architecture for DRAMs.
BACKGROUND OF THE INVENTION
Large numbers of DRAM cells must be interconnected with wordlines, and wordlines and spaces between wordlines are a factor in determining the size of a folded-bitline cell. Typically, wordlines are formed as thin films of a conductor, such as aluminum or polysilicon, deposited on insulating materials on the semiconductor surface and defined as lines photolithographically. Efforts to shrink wordlines and the spaces between wordlines are limited since both line widths and spaces cannot photolithographically be made smaller than the line width, for example, decreasing the line width usually increases the line-to-line spacing and so the overall wordline pitch is not improved. The cost of decreasing the photolithographic minimum dimension is high, and each such effort has defined succeeding generations of semiconductor products. In each generation of DRAM cells, the photolithographically defined wordline and/or it's associated space have thus been formed at the photolithographic minimum dimension. Each such effort has defined succeeding generations of semiconductor products. In each generation of DRAM cells, the photolithographically defined wordline and/or its associated space have thus been formed at the photolithographic minimum dimension.
In the folded-bitline DRAM cell design, both an active and as a passing wordline pass through each cell, as illustrated in commonly assigned U.S. Pat. No. 4,801,988 ("the '988 patent"), issued to D. M. Kenney, entitled "Semiconductor Trench Capacitor Cell with Merged Isolation and Node Trench Construction," and shown therein which is incorporated herein by reference. Crossing over trench capacitors 505A and 510A for a pair of cells in FIG. 1, are wordlines 515A and 520A. The space required for such a DRAM cell is a minimum dimension for each of the two wordlines in each cell and an additional minimum dimension for each space between each wordline. Thus the total minimum length of the traditional folded bitline cell is 4 minimum dimensions. The width of the cell is at least two minimum dimensions, of which one is for the components in the cell and the other is for a thick isolation (a trench capacitor can be a part of this isolation) in the space between cells. Thus, the minimum area of a traditional cell has been 8 square minimum dimensions, or 8 squares.
One approach to avoid the photolithographic limit is to provide a wordline formed of a conductive sidewall rail. The width of such rails is determined by the thickness of the deposited conductor, and this thickness can be significantly less than a minimum photolithographic dimension. Commonly assigned U.S. Pat. No. 5,202,272 ("the '272 patent"), issued to Hsieh, entitled "Field Effect Transistor Formed With Deep-Submicron Gate," and U.S. Pat. No. 5,013,680 ("the '680 patent"), issued to Lowrey, entitled "Process for Fabricating a DRAM Array Having Feature Widths that Transcend the Resolution Limit of Available Photolithography," all of which are incorporated herein by reference, teach methods of using a subminimum dimension conductive sidewall spacer rail to form a wordline.
One problem encountered in the use of such subminimum dimension spacer rail wordlines is the difficulty of precisely controlling the length of the device and the extent of lateral diffusion of the source and drain. For example, small variations of spacer thickness or lateral diffusion can result in a large variation in the length of the subminimum dimension channel. The result can be large leakage currents on the one hand and degraded performance on the other. The present invention avoids the difficulties of the subminimum dimension sidewall spacer rail wordlines of the prior art.
Moreover, many prior art structures and techniques for sublithographic wordlines and/or bitlines do not provide a bitline contact which is borderless to the wordline.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a folded bitline DRAM cell with a photolithographically formed gate, the cell having an area of less than 8 squares with the bitline being borderless to the wordline. It is also a feature of the present invention that a minimum subdivision wordline makes approximately minimum individual gate segments with the bitline contact being borderless to the wordline.
It is still a further object of the present invention to provide a transistor with individual segment gate conductors and a subminimum dimension gate connector with the bitline contact being borderless to the wordline.
These and other objects of the invention are accomplished by a semiconductor structure comprising a DRAM cell which has a transistor which includes a gate. The gate includes an individual segment of gate conductor such as polysilicon on a thin dielectric material. The transistor further has a single crystal semiconductor substrate having a source/drain region. An active conducting wordline is deposited on top of and electrically contacting a segment gate conductor, the wordline being a conductive material having a top and sidewalls. Electrically insulating material completely surrounds the active wordline except where the active wordline contacts the segment gate electrodes. The insulating material surrounding the active wordline includes silicon nitride overlying the top and surrounding a portion of the sidewalls thereof, and silicon dioxide surrounds the remainder of the side walls of the active wordline. A bitline contact contacts the source/drain region and the insulating material surrounding the active wordline to thereby make the bitline contact borderless to the wordline. A fully encased passing wordline is also provided which is spaced from and insulated from the segment gate conductor and the active wordline.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-11 are longitudinal sectional views showing the steps in one embodiment of the invention utilized in manufacturing a DRAM cell having a transistor with active wordlines which are borderless to bitline contacts;
FIG. 12 is a top plan view of a first step in manufacturing a DRAM cell of the transistors according to another embodiment of this invention;
FIG. 13 is a longitudinal sectional view taken substantially along the plane designated by line 13--13 of FIG. 12;
FIG. 14 is a top plan view of the next step following that shown in FIG. 13 in the manufacture of DRAM cell;
FIG. 15 is a sectional view taken substantial along the plane designated by line 15--15 of FIG. 14;
FIG. 15a is a longitudinal sectional view of the next step after that shown in FIG. 15 in this process;
FIG. 16 is a top plan view of the next step after that shown in FIG. 15a;
FIG. 17 is a longitudinal sectional view taken substantially along the plane designated by line 17--17 of FIG. 16;
FIG. 18 is a top plan view of the next step in the manufacturing process after the step shown in FIG. 16; and FIG. 19 is a longitudinal sectional view taken substantially along the plane designated by line 19--19 of FIG. 18.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 through 11 show diagrammatically the steps in forming a DRAM cell according to the present invention. The preferred and illustrated embodiments utilize a single crystal silicon wafer with silicon technology to form the cells, however, germanium, gallium arsenide or other semiconductor material could also be used. Never-the-less, silicon is the most widely and commonly used material, so the invention will be described with respect to the use of silicon.
The term horizontal as used herein is defined as a plane parallel to the conventional planar surface of the semiconductor chip or wafer, regardless of the orientation of the chip. The term vertical refers to a direction generally normal or perpendicular to the horizontal as defined above. Prepositions such as "on", "side", (as in "sidewall"), "higher", "lower", "over", and "under" are defined with respect to conventional planar surfaces being on the top surface of the chip or wafer, irrespective of the orientation of the chip.
The folded-bitline DRAM architecture is one example of an array of transistors for which the present invention is applicable. The present invention provides a DRAM cell with a transistor having a gate formed from an individual segment of gate conductor and has a length (within overlay tolerances) and a width of about 1 minimum dimension. A wordline interconnecting such segment gates and the space between the wordlines each have a subminimum dimension as a result of the wordline being formed by a directional etch of a conformal conductor along the sidewall. The wordline also is encased in a dielectric or insulating material which makes the wordline borderless to the bitline contact. While the formation of just two array transfer devices is shown, it is to be understood that the array has many cells formed this way which are interconnected.
The figures in the present invention show the steps and the process of fabricating a DRAM cell of the present invention. Initial process steps in the manufacture of the invention are illustrated in FIGS. 3-10 of commonly assigned U.S. Pat. No. 5,264,716 ("the '716 patent"), issued to D. M. Kenney entitled "Diffused Buried Plate Trench DRAM Cell Array," incorporated herein by reference. In the '716 patent, however, a whole wordline is defined by a masking step. The present invention individual rectangular or square gate stack segments instead of the whole wordline are defined by that masking step, each segment having only a single gate for a single transistor. Preferably the gate segments have dimensions of about 1 minimum dimension in each direction along the planar surface (or a little more) to accommodate overlay tolerances, and the gates are aligned to fill the minimum dimension space between trench capacitors.
Referring now to the drawings, the steps in forming a DRAM cell including a transistor according to the present invention are shown. As seen in FIG. 1, a single crystal silicon substrate 10 is provided having polysilicon gates 12 formed thereon which are mounted on thin film dielectric material 14. The transistor is provided with a source/drain region one of which is shown at 16 and a deposit of silicon dioxide 17 is formed between the two gates 12 overlying the source/drain region 16. Dielectric material 19 is "behind" gates 12 as well as the sides thereof. (It is to be understood that other devices such as capacitors, straps, and connections are typically found in the substrate and form a part of the DRAM cell, but these are omitted for clarity of illustration.) A silicon nitride layer 18 which is preferably a 300-800 angstroms thick overlies the polysilicon gate electrodes 12. Typically the gates 12 are 500-1500 angstroms thick and the dielectric layer 14 is 50-80 angstroms thick. Vertical sides of gates which are shown in FIG. 1 are further surrounded by silicon nitride (spacers) 50-400 angstroms thick fully encasing the gate material 12.
As shown in FIG. 2 a layer of silicon dioxide 22 4000-8000 angstroms thick is applied over the nitride layer 18 and by using a conventional photoresist and anisotropic etching techniques, a pattern in the photoresist is exposed and developed and the underlying silicon dioxide 22 is etched to provide openings 24 in the silicon dioxide. The silicon nitride 18 acts as an etch stop layer and the etching is done anisotropically using reactive ion etching (RIE techniques) all as are well known. As will become apparent later, these openings will provide the basis for two wordlines in one lithographic dimension.
Following the etching of the openings 24 in the silicon dioxide 22 a conformal layer of silicon nitride 26 about 300-1300 angstroms thick is applied over the entire surface of the silicon dioxide 22, including the sidewalls of the openings 24 as shown in FIG. 3. A layer of silicon dioxide 28 is then deposited over the silicon nitride 26 and the surface polished back to remove the silicon dioxide and silicon nitride on the one surface 29 of the silicon dioxide 22 to provide the configuration shown in FIG. 4. This results in the conformal silicon nitride 26 being divided by a silicon dioxide filler material 30 into a pair of legs 34, which act as "place holders" for the wordline which will be formed later, connected by a U section 35 and a top planar surface 29. This is shown in FIG. 4.
The planar surface 29 is then masked with conventional photoresist, patterned and the silicon nitride legs 34 are etched to provide the pair of openings 36 on either side of the silicon dioxide filler 30 as shown in FIG. 5. Although the silicon nitride place holders 34 now form a "loop", the resist mask will prevent the silicon nitride removal at the ends of loops outside of the array, thereby allowing non-connected passing and active wordlines. After etch, the resist mask is stripped. The silicon dioxide is again covered with photoresist 38 as shown in FIG. 6 which photoresist is then patterned and developed over the leg 34 which overlies the gate electrode 12, and the remaining silicon nitride in leg 34 that is to become the active wordline is etched to provide an opening 40 through the silicon nitride 35 and underlying silicon nitride 18 to the gate electrode 12 there below.
The photoresist 38 is then stripped and a conformal titanium nitride coating 44 is applied over all the exposed surfaces of the silicon dioxide 22 including the openings 40 and the top surface thereof as shown in FIG. 7.
Following the application of the titanium nitride 44, a layer of aluminum is deposited over titanium nitride surface 44 which defines top coating 50 of aluminum with a pair of aluminum lines 46 and 48 as shown in FIG. 8. The lines 46 will contact the titanium nitride coating on the gate electrodes 12, thus providing contact thereto for the active wordline. Line 48 forms the passing wordline which is spaced from the gate electrode 12 by silicon nitride layers 18 and 35.
The top surfaces 50 of the aluminum and titanium nitride are then polished and the exposed lines 46 and 48 of the aluminum are shown in FIG. 8a.
To make the wordline rails borderless to bitline contact, the exposed top surfaces of the aluminum lines 46 and 48 and titanium nitride are then etched with an etch media selective to the silicon dioxide so that the top surfaces 52 of the lines 46 and 48 are recessed within the silicon dioxide 22. Silicon nitride caps 54 are then deposited on the tops 52 of each of the aluminum lines 46 and 48 and polished as shown in FIG. 9.
Silicon dioxide is then etched selectively to the silicon nitride 54 and the aluminum lines 46 and 48 to expose the nitride caps 54 and a portion of the sidewalls of the aluminum lines as shown in FIG. 9a.
Following this, conformal silicon nitride 56 is deposited over the nitride caps 54 which extends down the side of each of the lines 46 and 48 and into contact with the top surface 59 of the silicon dioxide 22 and then non-isotropically etched to form spacers. This is shown in FIG. 10.
Thereafter, a layer of silicon dioxide 58 is CVD deposited over the entire exposed surface as shown in FIG. 10a. This silicon dioxide is then masked with photoresist, exposed, developed, and anisotropically etched to provide an opening 62 extending through to the source/drain region 16.
Connecting material 64 is then deposited on the top surface 66 of the silicon dioxide 58 and extends into the opening 62 to form a bitline contact 68 in contact with the source/drain region 16 as shown in FIG. 11. Connecting material 64 acts as the bitline contact, the aluminum line 46 acts as the active wordline, and aluminum line 48 acts as the passing wordline. Thus as can be seen, the bitline contact 68 can be somewhat misaligned as shown in FIG. 11, actually overlying and in contact with the insulating material surrounding the active wordline 46, the active wordline 46 being surrounded by the silicon nitride cap 56 and a portion of the silicon dioxide 22 adjacent the finger 46. Thus the bitline contact 68 is borderless to the active wordline 46 by virtue of the silicon nitride cap 56 and the section of silicon dioxide 22 on the active wordline 46 and enclosing it. Thus, two wordlines are contained within one photolithographic dimension reducing the number of squares per cell from 8 to less than 8 and approaching 4.
Referring now to FIGS. 12-19, another embodiment of the present invention is shown. As shown in FIGS. 12 and 13, the substrate has the gate electrodes 12 and the nitride layer 18 deposited thereon with a coating of silicon dioxide 22 as in the previous embodiment in FIG. 1. However, in this embodiment, a poly silicon mask 70 is deposited over the silicon dioxide 22. A hybrid photoresist material 72 is applied over the polysilicon mask 70 and exposed and developed to the desired patterns for the active and passing wordlines and the underlying polysilicon mask 70 is selectively etched with respect to the photoresist to provide the openings 73 as shown in FIG. 13. The hybrid photoresist 72 is a combined positive/negative acting photoresist as described in commonly assigned U.S. patent application Ser. No. 08/715,287, Filed Sep. 16, 1996, entitled "Frequency Doubling Hybrid Photoresist", (which is incorporated herein by reference) which allows sublithographic spaces to be formed. However, the patterns are loop shaped having end portions 74 as well as the desired thin strips forming the openings 73.
In the next step as shown in FIGS. 14 and 15, trim mask 75 of conventional photoresist is applied over the end portions of 74 of the loops and the exposed underlying silicon dioxide 22 is etched selectively to the photoresist 72 and the polysilicon 70 to provide the openings 76 and 78 therein extending down to the nitride layer 18. The photoresist and polysilicon mask are then stripped.
Following this the entire structure is covered with photoresist and patterned and developed to open the openings 76 while leaving the openings 78 containing the photoresist 72. The silicon nitride layer 18 at the bottom of the openings 76 is then selectively etched to provide openings 79 to the gate polysilicon 12 as shown in FIGS. 16 and 17.
The titanium nitride is a conducting material and the layer is about 50-300 angstroms thick to guarantee shunting of aluminum with a thin layer on the sidewalls, and to guarantee a barrier layer between conductor material and the polysilicon gate if necessary.
Following this a conformal coating of aluminum is applied over the top surface 82 of the TiN, T over silicon dioxide 22 which aluminum also extends as lines 84 and 86 into openings 76 and 78 respectively, and Chem-mec polished to oxide 22. The aluminum lines 84 will act as the active wordlines and the lines 86 will act as the passing wordlines. The results are shown in FIG. 18 top down and in FIG. 19 cross section.
The processing from this point to provide a final product is the same as shown in the previous embodiments. With the structure shown in FIG. 19, corresponding to the structure shown in FIG. 8A.
Accordingly, the preferred embodiments of the present invention have been described. With the foregoing description in mind, however, it is understood that this description is made only by way of example, that the invention is not limited to the particular embodiments described herein, and that various rearrangements, modifications, and substitutions may be implemented without departing from the true spirit of the invention as hereinafter claimed. | A semiconductor structure and method of making the same are disclosed which includes a DRAM cell which has a transistor which includes a gate. The gate includes an individual segment of gate conductor such as polysilicon on a thin dielectric material. The transistor further has a single crystal semiconductor substrate having a source/drain region. An active conducting wordline is deposited on top of and electrically contacting a segment gate conductor, the wordline being a conductive material having a top and sidewalls. Electrically insulating material completely surrounds the active wordline except where the active wordline contacts the segment gate conductor. The insulating material surrounding the active wordline includes silicon nitride overlying the top and surrounding a portion of the sidewalls thereof, and silicon dioxide surrounds the remainder of the side walls of the active wordline. A bitline contact contacts the source/drain region and the insulating material surrounding the active wordline to thereby make the bitline contact borderless to the wordline. A fully encased passing wordline is also provided which is spaced from and insulated from the segment gate conductor and the active wordline. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 60/753,520 (“the '520 application”), which was filed on Dec. 22, 2005 and entitled “THREADED LIFT CORD SPOOL FOR COVERINGS FOR ARCHITECTURAL OPENINGS.” The '520 application is incorporated by reference into the present application in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to retractable coverings for architectural openings and more particularly to a spool about which a lift cord can be wrapped and unwrapped while extending and retracting the covering.
2. Description of the Relevant Art
Retractable coverings for architectural openings can assume numerous forms including retractable shades, venetian blinds, vertical blinds, cellular shades, and the like. In such coverings, a lift cord is typically utilized to move the covering between extended and retracted positions and the lift cord is sometimes wrapped around a spool, rod, or the like during a retracting movement. Lift cords can become entangled on the spool thereby inhibiting error-free operation of the covering and, accordingly, systems have been devised for discouraging entanglement of a lift cord.
One system for preventing entanglement is to provide a thread on the lift cord spool so that the cord is confined within the thread as it is wrapped about the spool and is therefore discouraged from becoming entangled. Another system for preventing entanglement consists of providing a surrounding housing to the spool which is closely spaced from the outer winding surface of the spool whereby only a single layer of cord is allowed on the spool thereby discouraging entanglement.
One cause of entanglement, when using a thread to confine the lift cord, resides in the lift cord being frictionally trapped within the thread and not being readily separated from the thread as the cord is being unwrapped from the spool and accordingly a system for assuring the removal of a lift cord from the thread of a lift spool during an extending movement of the covering would be desirable.
SUMMARY OF THE INVENTION
The present invention employs a lift system for a retractable covering for architectural openings wherein the lift cord for moving the covering between extended and retracted positions is positively controlled to prevent entanglement. The lift spool has an external thread in which the lift cord is confined and the lift cord is laid into the thread with a follower that is internally threaded and adapted to move axially along the length of the threaded spool upon rotation of the threaded spool. As the follower is moved along the threaded spool, the lift cord is fed into the thread on the spool with the lift cord being fed through a cord passage in the follower.
When the cord is removed from the external thread in the spool, as when the spool is rotated in an opposite direction, the follower moves in an opposite axial direction and the lift cord is removed through the cord passage in the follower. To prevent the lift cord from being trapped in the thread thereby causing entanglement, the internal thread on the follower has an end provided immediately adjacent to the cord passage with the end of the internal thread extending into the external thread of the spool to lift the cord out of the external thread thereby removing any possibility the cord will become trapped or hung up in the external thread as the spool is rotating causing entanglement.
Other aspects, features and details of the present invention can be more completely understood by reference to the following detailed description of a preferred embodiment, taken in conjunction with the drawings and from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary isometric of a retractable covering for architectural openings incorporating the lift cord control system of the present invention.
FIG. 2 is an isometric similar to FIG. 1 with the shade material having been removed and with the middle rail of the covering in a lowered position.
FIG. 3 is an isometric similar to FIG. 2 with the bottom rail having been raised in the covering.
FIG. 4 is a diagrammatic isometric showing the control system of the present invention incorporated into the remainder of the covering with the shade material removed.
FIG. 5 is an exploded isometric of the lift cord control system of the invention.
FIG. 6 is an isometric similar to FIG. 5 with the components of the lift cord control system integrated.
FIG. 7 is an isometric looking downwardly on the threaded spool in a first direction.
FIG. 8 is an isometric looking downwardly on the threaded spool from an opposite direction.
FIG. 9 is an end elevation looking at the left end of the spool as shown in FIG. 8 .
FIG. 10 is an isometric looking downwardly on a follower used with a threaded spool in accordance with the present invention.
FIG. 11 is a top plan view of the follower of FIG. 10 .
FIG. 12 is a front elevation of the follower of FIG. 10 .
FIG. 13 is a rear elevation of the follower of FIG. 10 .
FIG. 14 is an isometric looking at the rear side of the follower used on a second threaded spool for the lift system of the present invention.
FIG. 15 is a top plan view of the follower shown in FIG. 14 .
FIG. 16 is a front elevation of the follower shown in FIG. 14 .
FIG. 17 is a rear elevation of the follower shown in FIG. 14 .
FIG. 18 is an isometric of the housing for the lift system of the present invention.
FIG. 19 is an isometric looking at one end of an end plug for a threaded spool of the lift system of the invention.
FIG. 20 is an isometric looking at the opposite end of the spool as shown in FIG. 19 .
FIG. 21 is a section taken along line 21 - 21 of FIG. 6 .
FIG. 22 is a section taken along line 22 - 22 of FIG. 6 .
FIG. 23 is a section taken along line 23 - 23 of FIG. 6 .
FIG. 24 is an enlarged section taken along line 24 - 24 of FIG. 6 .
FIG. 25 is an enlarged section taken along line 25 - 25 of FIG. 6 .
FIG. 26 is an enlarged section taken along line 26 - 26 of FIG. 24 .
FIG. 27 is a section taken along line 27 - 27 of FIG. 26 .
FIG. 28 is an enlarged section taken along line 28 - 28 of FIG. 27 .
FIG. 29 is a section similar to FIG. 27 with the lift cord spool having been rotated in a clockwise direction approximately 30 degrees with the catch thread of the follower engaging the lift cord.
FIG. 30 is a top plan view of the lift system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The threaded cord spool 32 of the present invention would find use in any covering for an architectural opening wherein a cord is wrapped or unwrapped about a generally cylindrical body depending upon the deployment of the architectural covering. For purposes of the present disclosure, the lift cord spool is disclosed in a top down/bottom up covering 34 of the type shown in FIGS. 1-4 . The covering includes a headrail 36 in which the operative components of the shade are housed, a bottom rail 38 including a roller 40 to which the bottom of the shade material 42 is attached and about which the shade material can be wrapped, and a middle rail 44 connected to the top of the shade material. The middle rail is connected to a control system with lift cords 46 a and 46 b operatively associated with opposite ends of the middle rail and with the lift cords being operatively engaged with threaded lift cord spools 32 of the present invention. The bottom rail is supported by its own set of lift cords 48 a and 48 b which are operatively incorporated into a counterbalance system 50 also disposed in the headrail. The shade material, which could be most any flexible material, is shown for illustrative purposes as including a pair of spaced vertical flexible sheets 52 of translucent material which are interconnected by a plurality of horizontally disposed flexible vanes 54 . The vanes assume a generally S-shaped transverse configuration when in the open position shown in FIG. 1 and become generally flat vertical planar sheets when the shade material is closed with the flat vanes overlapping each other. The shade material is not shown in the closed position, but a complete understanding of a covering of the general type disclosed in FIGS. 1-3 can be found in U.S. application Ser. No. 10/642,017, now U.S. Pat. No. 7,063,122, which is of common ownership with the present application and the disclosure of which is hereby incorporated by reference.
FIG. 2 shows the covering 34 with the middle rail 44 fully extended in adjacent relationship with the fully extended bottom rail 38 so there is no shade material 42 extending across the opening in which the covering would be mounted. FIG. 3 shows both the bottom rail and the middle rail in a retracted or raised position adjacent to the headrail 36 . As will be appreciated from the generic description of the covering as being a top down/bottom up covering, the top of the shade material can be lowered or the bottom can be raised depending upon the deployment of the shade material desired.
With reference to FIG. 4 , the covering 34 of FIGS. 1-3 is shown diagrammatically and with the shade material removed. Both the middle rail 44 and bottom rail 38 are shown in phantom lines. As mentioned previously, the bottom rail is supported by lift cords 48 a and 48 b that are operatively associated with a counterbalance system 50 described in detail in the aforenoted U.S. Pat. No. 7,063,122. In that system a lift cord 48 a and 48 b is associated with each end of the bottom rail and extends upwardly around a vertical pulley 56 and then horizontally until it passes around a friction pin 58 and subsequently onto one of two rotatable spools 60 . The spools are rotated in unison and are operatively associated with a constant tension spring 62 so that regardless of the direction of rotation of the spools, a constant spring bias is created sufficient to support the bottom rail. The bottom rail can therefore be manually lifted or lowered between any selected position within an architectural opening in which the covering is mounted and it will retain that position due to the counterbalance system that supports the bottom rail. Also, movement of the bottom rail relative to the middle rail causes the shade material 42 to be wrapped around or unwrapped from the roller 40 disposed within the bottom rail which is also spring biased toward a wrapped position of the shade material in a conventional manner and as described in the aforenoted U.S. Pat. No. 7,063,122.
A threaded lift cord spool system 64 including a pair of cord spools 32 is utilized in controlling the lift cords 46 a and 46 b associated with the middle rail 44 and as will be appreciated by reference to FIG. 4 , there are two threaded lift spools 32 with one having a right-hand thread and the other a left-hand thread. Otherwise the spools are identical. The two spools are utilized in the covering 34 disclosed in the present application but it should be understood the concept of the present invention is applicable to any threaded spool and more specifically to a system for controlling the wrapping and unwrapping of a cord about a threaded spool.
In general, each threaded spool 32 is associated with a lift cord 46 a and 46 b that is in turn associated with one end of the middle rail 44 . The middle rail has first and second spaced axially extending friction pins 66 a and 66 b respectively at each end thereof and an anchor 68 is provided within the headrail for anchoring one end of each lift cord. The lift cord associated with each threaded spool extends from its associated anchor 68 in a horizontal direction around an arcuate block 70 and from the block vertically downwardly where it is wrapped around the second friction pin 66 b adjacent one longitudinal edge of the middle rail and subsequently around the first friction pin 66 a adjacent the opposite longitudinal edge of the middle rail before extending upwardly and passing around a pulley 72 from which it extends generally horizontally to the associated threaded spool 32 . As will be described in more detail later, the lift cord is wound onto the threaded spool or unwound from the spool depending upon whether or not the middle rail is raised or lowered respectively and the threaded spools are manually rotatably driven by an endless drive cord 74 at one end of the covering. The endless drive cord extends around a drive wheel 76 that is in turn operatively connected to the lift spools 32 through a two-way clutch 78 so that rotation of the drive wheel in either direction by the drive cord will rotate a drive shaft 80 associated with the threaded spools. The two-way clutch, however, allows the threaded spools to remain in any position in which they are moved until the drive wheel is again rotated by the drive cord. Again, this system as thus far described is disclosed in detail in the aforenoted U.S. Pat. No. 7,063,122.
It will be appreciated from the above that by rotating the drive wheel 76 with the drive cord 74 , the middle rail 44 can be raised or lowered depending upon the direction of rotation of the drive wheel. By manually lifting or lowering the bottom rail 38 , it can be moved between any selected position through its operative connection with the counterbalance system 50 . Accordingly, the shade material 42 can be extended to any desired degree between the middle rail and the bottom rail and positioned at any desired location between the headrail 36 and the fully extended position of the bottom rail 38 .
As is also described in detail in the aforenoted U.S. Pat. No. 7,063,122, when the drive cord 74 rotates the drive wheel 76 in a direction causing the lift cords 46 a and 46 b to be wrapped onto their associated threaded spools 32 , the tension placed in the lift cord between the spool and the first friction pin 66 a directly associated therewith causes the lift cord to grip the first friction pin thereby lifting the associated edge of the middle rail 44 relative to the opposite edge of the middle rail which pivots the middle rail about a longitudinal axis, and consequently the connected flexible vanes 54 in the shade material 42 , between the open position of FIG. 1 and a closed position (not shown) wherein the vanes are substantially vertically oriented in a flat planar configuration and slightly overlapped with each other. When the lift cords are unwrapped from the associated threaded spools due to rotation of the drive wheel in an opposite direction, the first friction pin 66 a , directly associated with the lift cord as it emanates from the threaded spool, is initially lowered until it becomes horizontally aligned with the second friction pin 66 b so that when the middle rail is thereby pivoted, the slats in the shade material are pivoted correspondingly to the open position of FIG. 1 .
The components of the threaded lift cord spool system 64 of the present invention are possibly shown best in FIG. 5 where again it will be appreciated there are two lift cord spools 32 with one having an external left-hand thread 82 and the other an external right-hand thread 82 on a cylindrical body. The spools are otherwise identical. Each spool has hexagonal openings 84 in its opposite ends for receipt of end plugs 86 that include a cylindrical body 88 insertable into the associated end of the threaded spool and a hexagonal head 90 that fits frictionally into the hexagonal opening at the associated end of the spool. As will be described in more detail later, each spool also has a radial slot 92 at one end extending from the external thread 82 to the hexagonal opening in that end.
A generally L-shaped follower 94 is associated with each threaded spool 32 and has a cylindrical passage 96 therethrough with an internal thread 98 adapted to mate with the external thread 82 on the associated spool. The followers are adapted to move axially along the length of their associated threaded spools upon rotation of the threaded spools and due to the opposite threads on the threaded spools, unitary rotation of the spools in one direction causes the followers to move toward each other and in the opposite direction causes the followers to move away from each other. The followers will be described in detail later but suffice it to say each follower has a cylindrical skirt 100 with an elongated, diagonal, arcuate cord slot 102 formed in the top surface thereof and with the slot being angled relative to the axis of the cylindrical skirt so as to be aligned with the thread on the underlying spool.
Each end plug 86 has a square passage 104 therethrough with the proximal end plugs at the adjacent ends of the threaded spools 32 receiving a dual axle connector 106 having a pair of axles 108 of square cross section extending in opposition directions so that the threaded spools rotate uniformly and in unison. The square passage in the end cap at the opposite or distal end of one threaded spool (the right threaded spool as seen in FIG. 5 ), is adapted to receive the square drive shaft 80 which is driven by the two-way clutch 78 described previously. In other words, it will be appreciated that by rotation of the drive wheel 76 , the square drive shaft will rotate both threaded spools in the same direction causing the followers 94 to move toward or away from each other depending upon the direction of rotation of the square drive shaft.
As will be described in more detail later, the threaded spools 32 and the shaft 80 and axles 108 upon which they are mounted, as well as the followers 94 , are confined within a generally U-shaped elongated housing 110 and the followers are slidably confined within the housing so they cannot rotate relative to the housing while the threaded spools on which they are mounted are rotated with the square drive shaft 80 . This arrangement assures uniform movement of each follower along its associated threaded spool upon rotation of the threaded spool.
FIGS. 7 , 8 and 9 show a threaded spool 32 as above described wherein the spool has either a left or right-hand thread 82 , the hexagonal opening 84 in each end, a cylindrical inner surface 112 and a cylindrical outer surface in which the external thread is formed. The radial slot 92 at one end of the spool is seen in FIGS. 8 and 9 to extend from the external thread 82 of the spool to the internal cylindrical surface 112 .
The two followers 94 are mirror images of each other with one follower illustrated in FIGS. 10-13 and the other in FIGS. 14-17 . Each follower has a horizontal upper leg 114 and a vertical lower leg 116 with the cylindrical skirt 100 and passage 96 extending through the vertical lower leg and the skirt. The internal thread 98 in the follower, as possibly best seen in FIG. 28 , commences inwardly of a flat front wall or surface 118 of the follower and extends to an end location 120 just past the front surface or wall 118 of the upper leg so as to be in alignment with the rearwardmost end 124 of the lift cord slot 102 . The internal thread therefore has two ends with one end 126 , the rearmost end, being positioned inwardly of the flat front wall or surface 118 of the follower and the other end 120 , the forwardmost end, at a location commensurate with the rearwardmost end 124 of the lift cord slot 102 , i.e. the end closest to the front wall 118 of the upper leg.
The upper leg 114 also has a horizontal passage 128 formed therein in which a pulley 130 is adapted to be mounted. A vertical hole 132 passes downwardly through the upper leg and the passage to receive a pivot pin 134 for the pulley. The pulley can be seen for example in FIG. 6 . The lower or vertical leg 116 of each follower has three flattened tabular corners, two 136 and 138 along its bottom and one 140 at its top, that cooperate with corresponding walls of the housing, as will be appreciated hereinafter, to prevent rotation of the follower relative to the housing. As mentioned previously, since the followers 94 are mirror images of each other, the skirt on one follower will confront the skirt 100 on the other follower and the front faces 122 of the followers will face in opposite directions when the followers are threadedly mounted on their associated spools.
With reference to FIG. 18 , the elongated housing 110 , as mentioned previously, is generally U-shaped in configuration having an open upper top 142 , a front wall 144 , a rear wall 146 , and a bottom wall 148 . The bottom wall has longitudinally extending tabs 150 for anchoring the housing to the headrail 36 of the covering 34 for the architectural opening. Each end of the housing has a U-shaped bearing surface 152 and a divider 154 at the midpoint of the length of the housing which also defines a U-shaped bearing surface 156 for rotatably supporting the end plugs 86 and the dual axle connector 106 respectively. As may possibly best be appreciated by reference to FIG. 24 , the front 144 and rear 146 walls of the housing are spaced from the bottom wall so as to define angled gaps 158 therebetween for receipt of the two lower flat tabular corners 136 and 138 of the followers 94 so that the followers are prohibited from rotating within the housing. The third flat tabular corner 140 at the top of the vertical leg of the follower overlies the front wall 144 for the same purpose. It will be appreciated, however, that the follower is allowed to slide along the length of the housing upon rotation of the lift spool 32 upon which it is threadably mounted.
The end plugs 86 are all identical and are illustrated in FIGS. 19 and 20 . As mentioned previously, they include the cylindrical body 88 with the hexagonal head 90 and a hollow axle 160 protrudes axially from the hexagonal head to be rotatably seated on a U-shaped bearing surface 152 or 156 of the housing. The square passage 104 through the end plug is adapted to receive either the square drive shaft 80 or the dual shaft connector 106 so that the end plugs and consequently the threaded spools are rotated in unison with the drive shaft.
FIGS. 6 and 21 - 23 show the aforenoted components of the threaded lift cord spool system 64 integrated and in operative relationship with each other. As will be appreciated, and as was mentioned previously, one end of each lift cord 46 a and 46 b is secured to an anchor block 68 in the headrail 36 and the opposite end is secured to an associated spool 32 . The end of the cord secured to the spool is connected by passing it through the radial slot 92 provided in the proximal end of the spool and the cord is held in position by thereafter inserting an end plug 86 into the end of the spool which becomes frictionally retained within the end of the spool with the cord and rotates with the spool due to the cooperation of the hexagonal head 90 of the end plug with the hexagonal opening 84 in the end of the spool. As the lift cord radiates outwardly through the radial slot in the end of the spool, it is fed into the external thread 82 of the spool and subsequently through the diagonal cord slot 102 in the skirt 100 of the associated follower. It thereby extends out of the cord slot and then around the pulley 130 on the follower before extending to the middle rail 44 and ultimately the anchor block 68 at its opposite end.
As will be appreciated, as the threaded spools 32 are rotated in one direction, the lift cords 46 a and 46 b are either laid into the external threads 82 through the cord slots 102 in the skirts or removed from the threads when the spools are rotated in the opposite direction. In the disclosed embodiment, one direction of rotation, as when the followers move away from each other, causes the cords to be laid in the spools and the middle rail to be raised. The opposite direction of rotation causes the followers to be moved toward each other removing the cords from the spools and allowing the middle rail to be lowered. Further, the internal thread on the follower and the external thread on the spool are obviously the same, allowing the lift cord to be carefully and controllably laid into the external thread in a continuous manner when the spool is rotated in one direction. When the spool is rotated in the opposite direction, the weight of the middle rail 44 which creates a tension in the lift cord, causes the lift cord to be lifted from the external thread again in a controlled manner as the follower 94 is moved along the threaded spool.
As mentioned previously, and as possibly best appreciated by reference to FIGS. 26-29 , the forewardmost end 120 of the internal thread 98 of the follower that terminates adjacent to the rearwardmost end 124 of the cord slot 102 in the skirt 100 of the follower has its termination location closely adjacent to or contiguous with the rearwardmost end of the slot. Accordingly, if during an unwinding movement of the spool, the lift cord does not easily lift out of the external thread 82 of the spool in which it is wound, the forwardmost end 120 of the internal thread as seen in FIG. 29 will engage the lift cord and force it out of the external thread of the spool. If the forwardmost end of the internal thread were not so positioned, the lift cord might remain within the external thread of the spool passing beyond the cord slot in the skirt of the follower and become entangled within the system. As best appreciated by reference to FIG. 29 , however, the interrelationship of the internal and external threads do not provide enough space for the lift cord to get therebetween and, accordingly, it is forced out of the external thread and through the cord slot in the follower for reliable operation. It should also be noted that the end 120 of the internal thread is shown as a radical surface relative to the cylindrical passage 96 that the surface could be inclined at an acute angle relative to the radical orientation illustrated so as to provide some lift should the surface engage the cord. An acute angle in the range of 5° to 15° has been found useful but not mandatory. An inclined alternative surface is illustrated in FIG. 27 in dashed lines.
It will be appreciated from the above a system has been disclosed for controlling the wrapping and unwrapping of a cord from a threaded spool by utilization of a follower having an internal thread mated with the external thread of the spool for movement along the length of the spool. By removing the cord from the external thread through a slot in the follower at a location immediately adjacent or contiguous with an end of the internal thread of the follower, the cord is forcibly removed from the external thread of the spool.
It will be appreciated, however, that the end 120 of the thread would not necessarily need to be used for forcing the cord out of the thread but rather a separate catch or thread follower (not shown) could be incorporated into the follower with the internal thread of the follower actually terminating before the cord slot in the follower. Such a catch or thread follower would of course project into the external thread 82 of the lift spool 32 immediately adjacent to the cord slot 102 in the follower so as to function similarly to the first described system. The most convenient system, however, is felt to employ the internal thread 98 of the follower itself for making sure the cord is lifted from the external thread 82 of the spool.
Although the present invention has been described with a certain degree of particularity, it is understood the disclosure has been made by way of example, and changes in detail or structure made be made without departing from the spirit of the invention as defined in the appended claims. | A system for assuring removal of a cord from its wrapping in an external thread of a spool utilizes a follower having an internal thread that moves along the spool upon rotation of the spool with the follower having a slot through which the cord is passed and a catch on the internal surface of the follower adjacent to the slot in the follower that projects into the external thread of the spool to force a removal of the cord from the thread. Preferably, the catch comprises one end of the internal thread in the follower which by its very nature projects into the external thread of the spool for engagement with a cord received in the external thread. | 4 |
BACKGROUND OF THE INVENTION
This invention relates generally to materials for addition to fused salt baths, and more particularly to materials which are in aqueous solution for addition by spraying to fused, anhydrous salt baths.
U.S. Pat. No. 4,113,511 commonly assigned, teaches that aqueous solutions of chemicals can be added to fused non aqueous baths by spraying the aqueous solution of the chemicals over the surface of the bath in droplet size, small enough to allow the water to evaporate before the sprayed composition impinges on the surface.
U.S. Pat. No. 4,273,591 teaches an apparatus that is useful in performing such spray addition of chemicals in aqueous solution to a fused anhydrous bath.
It has been found, however, that many aqueous solutions of different alkali metal hydroxides and alkali metal nitrates for treating metals, such as for scale conditioning present various types of problems, and hence are less desirable for use in the above process and apparatus. It is therefore highly desirable to provide a balanced, stable aqueous solution of materials which will remain constant, and in solution, and which will spray uniformly and consistently under operating conditions in a commercial environment. This is especially necessary when making aqueous solution additions to fused anhydrous baths containing alkali metal salts.
SUMMARY OF THE INVENTION
According to the present invention, it has been found that a very good aqueous solution of material for addition to fused anhydrous metal treating baths containing alkali metal nitrate and alkali metal hydroxide is provided by an essentially saturated uniform aqueous solution comprising an alkali metal hydroxide and an alkali metal nitrate, wherein the solution is liquid at 50° C. and has a viscosity sufficiently low to be sprayed through nozzle means to form droplets, and which solution is free of precipitants between 50° C. and 110° C. The bath may contain other materials such as chlorides, permangantes, etc.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been found that in practicing the invention as described in the above noted U.S. Pat. No. 4,113,511, for adding alkali metal hydroxide and alkali metal nitrates to fused anhydrous metal treating baths it is extremely desirable to control the addition involved to certain types of aqueous solutions having very definite characteristics. By controlling the characteristics of the additional materials, certain detrimental effects such as unwanted precipitates, nozzle clogging, elimination of detrimental excess water, and composition imbalance can be reduced, or eliminated as well as providing a commercially economical addition system.
It has been found that when dealing with the alkali metal hydroxide alkali metal nitrate system, it is most advantageous to utilize a saturated aqueous solution of the alkali metal nitrate and the alkali metal hydroxide. The solution must be of sufficiently low viscosity to be sprayed through a nozzle to form droplets, and be liquid at 50° C.
It must also be free of precipitates between 50° C. and 110° C. As used herein the term "essentially saturated solution" means that the least soluble material or materials at the desired level of materials relative to each other be in essentially saturation amounts in the water, the remaining materials being in less than saturation amount. To determine this, the desired anhydrous balance of materials (including water of hydration) is first determined. When this has been determined just enough water is added to provide complete dissolution of the least soluble component, and to insure that the composition is liquid at 50° C., and the material has a low enough viscosity to be sprayed to form droplets, and is free of precipitates between 50° C. and 110° C.
Listed below are several examples of aqueous solutions including alkali metal hydroxide and alkali metal nitrates, as well as chlorides and permanganates in some examples.
EXAMPLE I
______________________________________55% WATER15% SODIUM NITRATE30% SODIUM HYDROXIDE100%______________________________________
EXAMPLE II
______________________________________53.6% WATER30.0% SODIUM HYDROXIDE15.0% SODIUM NITRATE 1.4% POTASSIUM HYDROXIDE*100.0%______________________________________
EXAMPLE III
______________________________________ 57% WATER30.0% SODIUM HYDROXIDE3.6% POTASSIUM HYDROXIDE*6.4% SODIUM NITRATE3.0% SODIUM CHLORIDE100.0%______________________________________
EXAMPLE IV
______________________________________60.0% WATER31.4% POTASSIUM HYDROXIDE* 8.4% SODIUM NITRATE 0.2% POTASSIUM PERMANGANATE100.0%______________________________________
EXAMPLE V
______________________________________55.0% WATER21.6% SODIUM HYDROXIDE21.2% SODIUM NITRATE 2.2% SODIUM CHLORIDE100.0%______________________________________
EXAMPLE VI
______________________________________55.0% WATER27.6% SODIUM HYDROXIDE13.0% SODIUM NITRATE 1.4% POTASSIUM HYDROXIDE* 3.0% SODIUM CHLORIDE100.0%______________________________________ *Based on commercial grade of KOH at about 85% purity.
The saturation of the various materials is as follows:
EXAMPLE I
Sodium Nitrate saturated in the presence of caustic soda.
EXAMPLE II
Sodium Nitrate saturated in the presence of that much Hydroxide.
EXAMPLE III
Sodium Nitrate and Sodium Chloride saturated in the presence of that much Sodium and Potassium Hydroxide.
EXAMPLE IV
Nitrate (NO 3 - ) saturated in the presence of that much Potassium Hydroxide.
EXAMPLE V
Sodium Chloride and Sodium Nitrate saturated in the presence of Sodium Hydroxide.
EXAMPLE VI
Nitrate (NO 3 - ) and Chloride (Cl - ) saturated in the presence of that much Sodium and Potassium Hydroxide.
It should be noted that in aqueous solution the various materials are ionized and the saturation is determined by the concentration at which these ions form a reaction product which will precipitate.
All of the solutions in the above noted examples can be easily sprayed through a nozzle having an equivalent orifice diameter of 0.018" without clogging, at 50° C. | According to the present invention a saturated aqueous solution comprising at least one alkali metal hydroxide and at least one alkali metal nitrate is provided which can be spray added to a fused anhydrous bath which contains alkali metal materials. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which claims benefit under 35 USC §119(e) to both U.S. Provisional Application Ser. No. 61/238,338 filed Aug. 31, 2009, entitled “SOLVENT EXTRACTION FOR THE REMOVAL OF IMPURITIES FROM OILS AND/OR FATS” and U.S. Provisional Application Ser. No. 61/238,351 filed Aug. 31, 2009, entitled “REMOVAL OF IMPURITIES FROM OILS AND/OR FATS” which are incorporated herein in their entirety.
STATEMENT OF FEDERALLY SPONSORED RESEARCH
[0002] None
FIELD OF THE INVENTION
[0003] The present invention relates generally to the process for removing impurities from triglycerides, especially prior to the conversion of triglycerides to fuel range hydrocarbons.
BACKGROUND OF THE INVENTION
[0004] There is a national interest in the discovery of alternative sources of fuels and chemicals, other than from petroleum resources. As the public discussion concerning the availability of petroleum resources and the need for alternative sources continues, government mandates will require transportation fuels to include, at least in part, hydrocarbons derived from sources besides petroleum. As such, there is a need to develop alternative sources for hydrocarbons useful for producing fuels and chemicals.
[0005] One possible alternative source of hydrocarbons for producing fuels and chemicals is the natural carbon found in plants and animals, such as for example, oils and fats. These so-called “natural” carbon resources (or renewable hydrocarbons) are widely available, and remain a target alternative source for the production of hydrocarbons. For example, it is known that oils and fats, such as those contained in vegetable oil, can be processed and used as fuel. “Bio Diesel” is one such product and may be produced by subjecting a base vegetable oil to a transesterification process using methanol in order to convert the base oil to methyl esters. After processing, the products produced have some what similar combustion properties as compared to petroleum-derived hydrocarbons. However, the use of Bio-Diesel as an alternative fuel has not yet been proven to be cost effective. In addition, Bio-Diesel often exhibits “gelling” thus making it unable to flow, which limits its use in pure form in cold climates.
[0006] Unmodified vegetable oils and fats have also been used as additives in diesel fuel to improve the qualities of the diesel fuel, such as for example, the lubricity. However, problems such as injector coking and the degradation of combustion chamber conditions have been associated with these unmodified additives. Since cetane (C 16 H 34 ), heptadecane (C 17 H 36 ) and octadecane (C 18 H 38 ) by definition have very good ignition properties (expressed as cetane rating), it is often desired to add paraffinic hydrocarbons in the C 16 -C 18 range, provided that other properties of the additive (such as for example, viscosity, pour point, cloud point, etc., are congruent with those of the diesel fuel.
[0007] Laboratory and commercial tests have demonstrated that vegetable oils and animal fats can be added to a refinery hydrotreater to produce hydrocarbon/transportation fuels. For example, contacting a diesel/vegetable oil mixture with a hydrotreating catalyst. However, the feedstock price accounts for ˜85% of operational cost for renewable diesel production, and there has been a rapid price increase for the biorenewable feeds currently used (e.g. refined soybean oil and technical tallow). Thus, it is now more economically attractive to use lower quality and less expensive feeds (e.g. inedible tallow, choice white grease and etc.) for making renewable diesel. For example, inedible tallow is about 20% cheaper than technical tallow, so for 1,000 BPD renewable diesel production, an annual feedstock saving of $4 millions can be realized by using the inedible tallow instead of technical tallow.
[0008] The problem associated with hydrotreating these lower priced and poorer quality oils/fats is, however, that these low quality oils/fats, such as, inedible tallow, choice white grease, etc., contain high concentration of solids, metals, phosphorus compounds and other impurities, which can potentially cause reactor fouling and poison the hydrotreating catalysts.
[0009] Therefore, development of an effective process for removing solids, metals, phosphorus compounds and other impurities from low quality oils and fats would be a significant contribution to the art.
SUMMARY OF THE INVENTION
[0010] Disclosed is a process for removing solids, metals, phosphorus compounds and other impurities from low quality triglyceride containing feedstock. The final treated triglyceride containing feedstock may be converted to fuel range hydrocarbons via hydrotreating processes.
[0011] In the first embodiment of the present invention, a process comprising (a) providing a feedstock comprising at least one triglyceride and one type of impurities; (b) admixing an organic solvent with the feedstock for a contacting time to form a mixture; (c) settling the mixture for a retention time to form a layer of treated feedstock, a layer of impurities, and a layer of organic solvent; and (d) recovering the layer of treated feedstock from the mixture, wherein the treated feedstock comprises less than 50% of the amount of the impurities than which is in the feedstock.
[0012] In the second embodiment of the present invention, a process is disclosed comprising contacting the treated feedstock from the first embodiment of the invention with a hydrotreating catalyst in a reaction zone under a condition sufficient to produce a reaction product containing diesel boiling range hydrocarbons, such condition includes a pressure of less than about 2000 psig and a temperature in the range of from about 260° C. to about 430° C.
[0013] In the third embodiment of present invention, a process comprising (a) providing a feedstock comprising at least one triglyceride and one type of impurities; (b) subjecting the feedstock to a first separation device to remove at least 25% of the impurities from the feedstock and to produce a first effluent stream; (c) admixing an acid or acid anhydride with the first effluent stream for a first contact time to form a first mixture; (d) admixing water with the first mixture for a second contact time to form a second mixture; (e) subjecting the second mixture to a second separation device to form an aqueous phase and oil phase; and (f) subjecting the oil phase to a third separation device to remove another portion of the impurities from the oil phase to produce a treated feedstock.
[0014] In the forth embodiment of the present invention, a process is disclosed comprising contacting the treated feedstock from the third embodiment of the invention with a hydrotreating catalyst in a reaction zone under a condition sufficient to produce a reaction product containing diesel boiling range hydrocarbons, such condition includes a pressure of less than about 2000 psig and a temperature in the range of from about 260° C. to about 430° C.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Refer to all four embodiments of the invention, triglycerides or fatty acids of triglycerides, or mixtures thereof, may be converted to form a hydrocarbon mixture useful for liquid fuels and chemicals. The term, “triglyceride,” is used generally to refer to any naturally occurring ester of a fatty acid and/or glycerol having the general formula CH 2 (OCOR 1 )CH(OCOR 2 )CH 2 (OCOR 3 ), where R 1 , R 2 , and R 3 are the same or different, and may vary in chain length. Examples of triglycerides useful in the present invention include, but are not limited to, animal fats (e.g. poultry grease, edible or inedible beef fat also referred as tallow, milk fat, and the like), vegetable oils (e.g. soybean, corn oil, peanut oil, sunflower seed oil, coconut oil, babassu oil, grape seed oil, poppy seed oil, almond oil, hazelnut oil, walnut oil, olive oil, avocado oil, sesame, oil, tall oil, cottonseed oil, palm oil, ricebran oil, canola oil, cocoa butter, shea butter, butyrospermum, wheat germ oil, illipe butter, meadowfoam, seed oil, rapeseed oil, borage seed oil, linseed oil, castor oil, vernoia oil, tung oil, jojoba oil, ongokea oil, algae oil, jatropha oil, yellow grease such as those derived from used cooking oils, and the like), and mixtures and combinations thereof.
[0016] Generally, the triglyceride comes with impurities such as phosphorus, metals (e.g. Alkali metals, alkali earth metals, or etc), solids, proteins and bone materials, or any combinations thereof. The amounts of these elements/compounds are generally in the range of from about 0 ppmw to about 10,000 ppmw.
[0017] Now refer to the first and second embodiments of the invention, the feedstock is generally kept in the range of the lowest temperature at which the feedstock remains as a liquid to 150° C. for at least 1 minute. After this step, an organic solvent is added to this feedstock. Any organic solvent may be used, in one embodiment of the invention, any type of a polar organic solvent, such as ethylene glycol, may be used.
[0018] Further referring to the first and second embodiments of the invention, the amount of organic solvent added to the feedstock may vary depend upon the amount of the feedstock to be mixed. According to the present invention, the amount of the organic solvent added is in the range from 0.1 to 50 wt %, calculated on the weight of triglyceride containing feedstock.
[0019] Further referring to the first and second embodiments of the invention, the organic solvent added to the feedstock is given sufficient contacting time to mix with the feedstock to thereby forming a mixture. The contacting time required for mixing the organic solvent with the feedstock may be affected by temperature of the feedstock as well as the types of device for mixing. In one embodiment, such contacting time is at least 1 minute under dynamic mixing action provided by devices such as such as stirrer or high shear mixers. The temperature of the mixture is maintained in the range of from the lowest temperature at which the mixture remains as a liquid to 150° C. during the mixing of organic solvent with the feedstock.
[0020] After the contacting time mentioned above, the mixture is allowed to set for a sufficient retention time, usually without any mixing action, to thereby form a layer of treated feedstock, a layer of impurities, and a layer of organic solvent. The retention time required in this step may be affected by the temperature of the mixture. In one embodiment, such retention time is at least 1 minute. The temperature of the mixture is maintained in the range of from the lowest temperature at which the mixture remains as a liquid to 150° C. during the setting of the mixture.
[0021] Further refer to the first and second embodiments of the invention, the layer of the treated feedstock is recovered but not limited by separation funnel.
[0022] Further refer to the first and second embodiments of the invention, the treated feedstock after the inventive process comprises less than 50% of the amount of the impurities than it is in the feedstock prior to the inventive process. In one embodiment where a polar organic solvent (e.g. ethylene glycol) is used, the treated feedstock after the inventive process comprises less than 80% of the amount of the impurities than it is in the feedstock prior to the inventive process.
[0023] Additionally, in both first and second embodiment of the invention, the layer of organic solvent may also be recycled for using in the treating of additional feedstock.
[0024] Now referring to the third and forth embodiments of the current invention, a feedstock comprising triglyceride and impurities is subject to a first separation device where in at least 25% of the impurities may be removed from the feedstock. Any suitable separation device capable of separating the solid from an oil phase feed may be used. A first separation device according to one embodiment of the current invention is a commercially available bag or cartridge filter with a pore size of at least 0.1 μm. In another embodiment with the feedstock being the inedible tallow, the first separation device of choice is a commercially available bag or cartridge filter with a pore size anywhere from 2 to 7 μm, which removes at least 50% of the impurities from the inedible tallow feedstock to produce the first effluent stream.
[0025] Further refer to the third and forth embodiments of the invention, the acid or acid anhydride, in principle all inorganic and organic acids having a pH of from 0-6 as measured at 20° C. in a one molar aqueous solution, may be used. For example: phosphoric acid, sulfuric acid, nitric acid, acetic acid, citric acid, tartaric acid, succinic acid, etc., or mixtures of such acids.
[0026] The acids or acid anhydride may be added in any concentration, in one embodiment of this invention, an aqueous solution of the acid added contains 0.1 to 99.9% of the acid in H 2 O.
[0027] Further refer to the third and forth embodiments of the invention, after the acid or acid anhydride being added to the first effluent stream, it is given a sufficient contacting time to mix with the first effluent stream to form the first mixture. The contacting time required for homogeneously mixing the acid or acid anhydride with the first effluent stream may be affected by temperature of the first effluent stream as well as the types of device for mixing. In one embodiment, such contacting time is at least 0.1 minute under dynamic mixing action provided by devices such as stirrer or high shear mixers. In another embodiment, such contacting time is about 0.1 to 60 minutes under dynamic mixing action provided by devices such as stirrer or high shear mixers. The temperature of the first mixture is maintained in the range of from the lowest temperature at which the first effluent stream remains as a liquid to 150° C. during contacting time mentioned above.
[0028] After the acid or acid anhydride being sufficiently mixed with the first effluent stream to form the first mixture, a small amount of water is added. In one embodiment, the amount of water added is in the range from 0.1 to 10 wt %, calculated on the oil.
[0029] After the water being added to the first mixture, it is given a sufficient contacting time to mix with the first mixture to form the second mixture. In one embodiment, such contacting time is at least 1 minute under dynamic mixing action provided by devices such as stirrer or high shear mixers. In another embodiment, such contacting time is about 1-1000 minutes under dynamic mixing action provided by devices such as stirrer or high shear mixers.
[0030] Again refer to the third and forth embodiments of the invention, the second mixture is then subject to a second separation device by which an aqueous phase and oil phase are separated. Any suitable separation device capable of separating an aqueous from an oil phase may be used. A second separation device according to one embodiment of the current invention is a commercially available centrifugation unit.
[0031] Finally the oil phase separated from the second mixture is subject to a third separation device wherein another portion of the impurities may be removed from the feedstock. Any suitable separation device capable of separating solids from an oil phase feed may be used. The third separation device according to one embodiment of the current invention is a commercially available bag or cartridge filter with a pore size of at least 0.1 μm. In another embodiment with the feedstock being the inedible tallow, the third separation device of choice is a commercially available bag or cartridge filter with a pore size between from 0.1 to 0.5 μm.
[0032] Now refer specifically to the second and the forth embodiments of the invention, the useful catalyst compositions in the present invention include catalysts effective in the conversion of triglycerides to hydrocarbons when contacted under suitable reaction conditions. Examples of suitable catalysts include hydrotreating catalysts. The term “hydrotreating” as used herein, generally describes a catalyst that is capable of utilizing hydrogen to accomplish saturation of unsaturated materials, such as aromatic compounds. Examples of hydrotreating catalysts useful in the present invention include, but are not limited to, materials containing compounds selected from Group VI and Group VIII metals, and their oxides and sulfides. Examples of hydrotreating catalysts include but are not limited to alumina supported cobalt-molybdenum, nickel sulfide, nickel-tungsten, cobalt-tungsten and nickel-molybdenum.
[0033] Further refer to the second and the forth embodiments of the invention, the metal of the catalyst useful in the present invention is usually distributed over the surface of a support in a manner than maximizes the surface area of the metal. Examples of suitable support materials for the hydrogenation catalysts include, but are not limited to, silica, silica-alumina, aluminum oxide (Al 2 O 3 ), silica-magnesia, silica-titania and acidic zeolites of natural or synthetic origin. The metal catalyst may be prepared by any method known in the art, including combining the metal with the support using conventional means including but not limited to impregnation, ion exchange and vapor deposition. In an embodiment of the present invention, the catalyst contains molybdenum and cobalt supported on alumina or molybdenum and nickel supported on alumina.
[0034] Still refer to the second and the forth embodiments of, the invention, this process in accordance with an embodiment of the present invention can be carried out in any suitable reaction zone that enables intimate contact of the treated feed and control of the operating conditions under a set of reaction conditions that include total pressure, temperature, liquid hourly space velocity, and hydrogen flow rate. The catalyst can be added first to the reactants and thereafter, fed with hydrogen.
[0035] In the second and forth embodiments of the present invention, either fixed bed reactors or fluidized bed reactors can be used. As used herein, the term “fluidized bed reactor” denotes a reactor wherein a fluid feed can be contacted with solid particles in a manner such that the solid particles are at least partly suspended within the reaction zone by the flow of the fluid feed through the reaction zone and the solid particles are substantially free to move about within the reaction zone as driven by the flow of the fluid feed through the reaction zone. As used herein, the term “fluid” denotes gas, liquid, vapor and combinations thereof.
[0036] The reaction conditions at which the reaction zone is maintained generally include a temperature in the range of from about 260° C. to about 430° C. Preferably, the temperature is in the range of from about 310° C. to about 370° C.
[0037] In accordance with the second and forth embodiments of the present invention, regardless of whether a fixed or fluidized bed reactor is used, the pressure is generally in the range of from about 100 pounds per square inch gauge (psig) to about 2000 psig. Generally, in a fixed bed reactor, the pressure is in the range of from about 100 psig to about 1500 psig. In a fixed bed reactor, the pressure can also be about 600 psig. In a fluidized bed reactor, the pressure is generally in the range of from about 400 psig to about 750 psig, and can also be about 500 psig.
[0038] The following example is presented to further illustrate the present invention and is not to be construed as unduly limiting the scope of this invention.
Example 1
Comparison Study on Impurities Removal from Tallow Using Ethylene Glycol Vs. Water
[0039] A comparison study was performed on impurities removal from tallow using ethylene glycol vs. water. The same procedure is followed. A 100 grams of tallow feedstock is added in a container and heated at a temperature of 90° C. for 0.5-1 hour. A 10 ml of ethylene glycol or water was added to the container and stirred with the tallow feedstock at a temperature of 90° for 2-3 hours. The mixture was then kept at 55-60° C. overnight without stirring. Three layers were formed comprising a layer of treated tallow, a brown color layer of impurities, and a layer of ethylene glycol. The result of the experiment has shown that under the same procedure and condition, less brown color layer of impurities were found in the container with water than it was in the container with ethylene glycol.
Example 2
[0040] An inedible tallow feed stock is provided. Such feedstock was subject to a commercially available sintered metal filter with a pore size of 2 μm to remove solids from the feedstock. The filtered feedstock was then mixed with phosphoric acid at the concentration of 75-85% for about 3 minutes followed by the addition of 5 wt % H 2 O. The tallow/phosphoric acid/water was further mixed for 60 minutes followed by a centrifugal step in which an aqueous phase and oil phase were separated. Sample of feedstock at the various stages were obtained and measured. As shown in Table 1, the results of this experiment indicates that there are a significant (more than 50%) reduction of the metals, phosphorus and solids concentration achieved by just after passing the feedstock through a sintered metal filter with pore size of 2 μm alone.
[0000]
TABLE 1
Removal of impurities from inedible tallow
Inedible
Inedible tallow after mixing
Impurities
Pre-treated
tallow after
with phosphoric acid and
(ppm)
inedible tallow
2 μm filter
centrifugal separation
Metals
146
48
2.2
Phosphorus
129
60
4.5
Solids
1400
210
210
[0041] The oil phase feed is further subject to a commercially available sintered metal filter with a pore size of 0.5 μm to remove some solids from the feedstock. Thereby, significantly purified inedible tallow is obtained.
[0042] While this invention has been described in detail for the purpose of illustration, it should not be construed as limited thereby but intended to cover all changes and modifications within the spirit and scope thereof. | Disclosed is a process for removing solids, metals, phosphorus compounds and other impurities from low quality triglyceride containing feedstock. The final treated triglyceride containing feedstock may be converted to fuel range hydrocarbons via hydrotreating process. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic tape cassette, particularly to a magnetic tape cassette through the front of which a magnetic tape is pulled out to perform recording or playback.
High-density recording has recently been performed on magnetic tape in a conventional magnetic tape cassette such as a video tape cassette of the VHS™ or Beta™ format. The magnetic tape cassette is usually constructed so that the magnetic tape can be pulled out of the cassette through the front opening thereof. The cassette is provided with a turnable guard panel for opening and closing the front opening of the cassette. When the magnetic tape cassette is not in use, the guard panel is closed over the front opening to protect the magnetic tape and prevent dust or the like from entering the cassette. When the cassette is to be used for recording, playback or the like, the guard panel is opened from the front opening and a tape pull-out member provided in a recording/playback apparatus is moved around to the back (non-magnetic side) of the magnetic tape to pull out the tape. The peripheral portions of the flanges of tape winding bodies on which the magnetic tape is wound are provided with teeth. When the cassette is not in use, a winding body brake is engaged with the teeth to prevent rotation of the tape winding bodies to keep the magnetic tape from slackening, jamming or the like. The winding body brake can be disengaged from the teeth of the flanges of the tape winding bodies by a brake disengaging lever moved into the cassette through a hole in the bottom of the cassette. Such a cassette is disclosed in Japanese Unexamined Published Utility Model Applications Nos. 57184/80 and 1415485/83.
An optical method for detecting the start and termination of running of the tape has also been used in a conventional magnetic tape cassette, as disclosed in the Japanese Unexamined Published Utility Model Application No. 50078/84. In the optical method, a light source is inserted into the cassette through a hole in the bottom thereof, and light from the light source is detected to sense the end of the magnetic tape to thereby control the drive of the recording/playback apparatus appropriately and automatically.
Since the conventional magnetic tape cassette requires holes for moving members such as the brake disengaging lever and the light source into the cassette as described above, the degree of dustproofing of the cassette is lowered due to the presence of the holes.
The construction of the conventional magnetic tape cassette is complicated because the cassette has a relatively large number of functions. It is desired to simplify the construction of the cassette to more effectively use the limited space in the cassette and to attain better quality control and higher reliability. Recently, various studies and development have been made in order to enable recording and playback with a higher quality For such purposes, the reliability of the conventional magnetic tape cassette should be made high enough to enable recording and playback at even higher densities.
SUMMARY OF THE INVENTION
The present invention was made in consideration of the above-mentioned circumstances.
Accordingly, it is an object of the present invention to provide a magnetic tape cassette in which members for performing a larger number of functions can be housed in a limited space and in which a high performance is enabled.
In a magnetic tape cassette provided in accordance with the present invention, which is of the type in which the tape is pulled out of the cassette to perform recording and playback, a pair of tape winding bodies on which a magnetic tape is wound are provided. The magnetic tape cassette is characterized in that an insert, which is moved into the cassette to detect the end of the magnetic tape through the use of light, is engaged with a winding body brake provided to prevent the rotation of the tape winding bodies, and is then moved so that the winding body brake is disabled.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a magnetic tape cassette constructed according to a preferred embodiment of the present invention;
FIG. 2 shows a perspective view of a winding body brake provided in the magnetic tape cassette;
FIG. 3 shows an exploded perspective view of the winding body brake;
FIG. 4 shows an exploded perspective view of an insert shown in FIG. 2;
FIG. 5 shows a perspective view of another insert for a magnetic tape cassette constructed according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention are hereafter described with reference to the attached drawings.
FIG. 1 shows a perspective bottom view of a magnetic tape cassette 1 constructed according to a preferred embodiment of the invention. FIG. 2 shows a perspective view of a winding body brake 13 of the magnetic tape cassette 1. FIG. 3 shows an exploded perspective view of the winding body brake 13.
A pair of tape winding bodies such as a reel having a flange, on which a magnetic tape is wound, are rotatably supported in the body of the magnetic tape cassette 1. The body of the cassette 1 is composed of upper and lower half portions 2 and 3.
The constitution of the cassette 1 is nearly the same as that of a conventional video tape cassette of the VHS™-format type or the like, except for the winding body brake 13 and a tape end detector.
The winding body brake 13 shown in FIG. 2 is provided between the center of the body of the cassette 1 and the front thereof, positioned so that the brake is disengaged from the teeth 12a and 12b of the lower flanges 11a and 11b of the tape winding bodies by the action of a rod-like insert 30 moved into the body of the cassette through the hole 8 of the lower half portion 3 of the cassette. The winding body brake 13 includes a first brake section 15 and a second brake section 20, which are turned about a pivot 14 projecting from the lower half portion 3 of the body of the cassette 1. The first brake section 15 has a first body 16 which is cylindrically shaped and through which the pivot 14 extends. The first brake section 15 also has a first engaging claw 17 extending from the first body 16 toward the teeth 12a, and a first operating portion 18 extending toward the hole 8. The second brake section 20 has a second body 21, through which the pivot 14 extends, a second engaging claw 22 extending from the second body toward the other teeth 12b, and a second operating portion 23 extending toward the hole 8.
As shown in FIG. 3, the first brake section 15, the second brake section 20, and a torsion spring 25 are fitted in that order on the pivot 14. The torsion spring 25, which is engaged at both ends thereof with the bottoms of spring engaging portions 19 and 24 of the first and second engaging claws 17 and 22, urges the claws so that the first engaging claw 17 is engaged with the teeth 12a, the second engaging claw 22 is engaged with the other teeth 12b, and the first and the second operating portions 18 and 23 contact with each other and close the hole 8.
The forms of the first and the second engaging claws 17 and 22 are not limited as far as they enable the claws to be engaged with the teeth 12a and 12b. For example, the first and the second engaging claws 17 and 22 can be shaped as plates extending in the direction of thickness of the cassette 1, as shown in FIG. 3. The forms of the operating portions 18 and 23 too are not limited. For example, the operating portions 18 and 23 can be shaped as plates extending along the inside bottom surface of the cassette 1 and capable of closing the hole 8, as shown in FIGS. 2 and 3. It is preferable that the operating portions 18 and 23 be appropriately inclined as a whole, or at least the surfaces of the operating portions facing the inside bottom surface of the cassette 1 be inclined, in order to more easily provide component forces for rightward and leftward movement as the insert 30 is moved into the cassette and comes into contact with the operating portions.
The recording playback apparatus in which the magnetic tape cassette 1 is loaded is provided with a rod-like insert 30 in a position corresponding to that of the hole 8 of the cassette. As shown in FIG. 4, two light sources 33, such as light-emitting diodes, are provided in the body 31 of the insert 30, which has a notch 34 for projecting light rightward and leftward from the light sources substantially in the longitudinal direction of the cassette 1. The insert 30 includes a contact portion 32 attached at the top of the insert and which contacts the operating portions 18 and 23. The contact portion 32 is appropriately pointed at the tip thereof and covers and protects the light sources 33.
When the magnetic tape cassette 1 is loaded in the recording/playback apparatus, a retainer holding the cassette is moved down so that the insert 30 is moved into the cassette through the hole 8 in a direction B indicated in FIG. 2. At that time, the contact portion 32 of the insert 30 starts moving the operating portions 18 and 23 away from each other. The insert 30 is then moved further into the cassette 1 so that the contact portion 32 of the insert moves the operating portions 18 and 23 away from each other by the diameter of the insert against the force of the torsion spring 25 in a direction C. At that time, the first and second engaging claws 17 and 22 are moved toward each other in a direction D so that they are disengaged from the teeth 12a and 12b. As a result, the tape winding bodies with the magnetic tape wound thereon are rendered rotatable. Along with the downward movement of the retainer, a guard panel 5 is opened about pivots 10 at both ends of the guard panel in a direction A indicated in FIG. 1, a tape pull-out member enters the cassette 1 through the openings 7a and 7b in the lower half portion 3 of the cassette, and winding body shafts for rotating the tape winding bodies are inserted into the winding body shaft holes 4 of the lower half portion of the cassette.
The insert 30 not only functions to unlock the winding body brake 13 as described above, but also functions to detect the end of the magnetic tape. For the detecting operation, the light projected rightward and leftward from the light sources 33 provided in the insert 30 passes across the tape path and passes through the openings 6 of the right and left side walls of the cassette 1 so that the light is received by light detectors facing the openings 6. The presence of the magnetic tape and that of the leading tapes, which are joined to the ends of the magnetic tape and differ in transmittance therefrom, are thus detected, and the running of the magnetic tape is controlled on the basis of detection signals produced by the light detectors.
Since the winding body braking part and tape end detecting part of the magnetic tape cassette 1 are not separately provided as done in a conventional VHS™-type tape cassette but are constructed integrally, the cassette 1 does not need to be provided with two holes for inserting a brake disengaging lever and light source, as in the conventional video tape cassette. For that reason, the dustproofing property of the cassette 1 is high. Also, the number of ribs, projections, etc., in the cassette 1 is minimized, simplifying the overall construction of the cassette and more effectively using the limited space in the cassette. This makes it possible to provide larger tape winding bodies, members for new functions, or the like in the cassette. The performance and reliability of the magnetic tape cassette 1 can thus be improved.
Since the brake disengaging device and the light sources for the magnetic tape cassette 1 are integrally provided by the single insert 3, the brake disengaging device and the light sources do not need to be separately provided in the recording/playback apparatus.
The present invention is not limited to the above-described embodiment and may be otherwise be embodied so that a winding body brake different in form from the winding body brake 13 and an insert constituted as shown in FIG. 5 are provided, for example. The insert 40 shown in FIG. 5 is made of a high-transmittance material such as transparent synthetic resin or glass. The body 41 of the insert 40 is shaped as a cylinder or prism. An optical prism 42 is provided at the tip of the body 41. The top of the prism 42 is composed of two faces extending downward to the center line of the top. The slopes have reflecting surfaces 43 which reflect light proceeding upward through the body 41 of the insert 40 from a single light source 33 provided under the insert in rightward and leftward directions Y and X so that the reflected light is received by respective light detectors. As for the insert 40 having the prism 42 and provided over the light source 33, only one light source is needed, the light source is easily protected from damage, and it is very easy to ensure the accuracy of optical paths in the rightward and the leftward directions Y and X.
According to the present invention, a winding body braking part and a tape end detecting part are integrally provided for a magnetic tape cassette, and an insert having a function of projecting light is used to disengage a winding body brake in the cassette. Therefore, the same functions as in a conventional magnetic tape cassette can be performed in a smaller space than in a conventional cassette, and the internal construction of the cassette is simplified, enhancing the manufacturing ease and reliability of the cassette. Although an insert for projecting light needs to be provided in the recording/playback apparatus, no member used disengaging the winding body brake need be provided as in a conventional apparatus. | A magnetic tape cassette of the type in which the tape is pulled out of the front of the cassette for recording and playback having a simplified but more reliable structure made possible by combining functions of a winding body brake and tape end detector integrally in a single member. A winding body brake is composed of a pair of commonly pivoted braking sections, each having a braking claw and operating section. The two operating sections cooperate to close an opening in the cassette when the cassette is not in use. To play or record on the cassette, an insert is inserted into the hole, moving apart the operating sections and thereby disengaging the braking claws from the teeth of tape winding bodies on which the magnetic tape in the cassette is wound. The insert also includes a light source or sources for detecting the ends of the tape. | 6 |
BACKGROUND
In the field of hydrocarbon exploration and recovery, holes (wellbores, boreholes) are drilled deep into the crust of the earth to access deposits of fluid hydrocarbons. The degree of fluidity and the makeup of deposits varies, it is desirable to have the ability to control flow from different deposits into the wellbore. Flow control devices are varied in nature and in their particular construction but all must be actuatable from a remote location, such as a surface location, to be of use to a well operator. One common configuration for remote actuation of a downhole device such as a flow control device is a pair of hydraulic control lines. One of the lines is employed to force the flow control device to an open position while the other is employed to force the device to a closed position. While such systems work well for their intended purpose, it is axiomatic that a number of flow control devices each having a pair of hydraulic control lines is problematic with respect to the number of control lines that would ultimately need to reach the location intended for remote control (e.g. surface). All such control lines would need to extend through a borehole that in most instances is 9⅝ inches in diameter. Large numbers of control lines in such a small diameter borehole take up space where space is at a premium. This is not an advantageous situation.
While the art has proposed several remedies for this issue, each is complex, adds cost, adds potential for malfunction and is overall not a panacea. The art is therefore still in need of a configuration and operative modality for flow control valves that reduces the number of necessary hydraulic control lines while maximizing the number of devices controllable thereby and while maintaining simplicity and cost efficiency of design.
SUMMARY
Disclosed herein is a control system for a plurality of devices including a plurality of devices in at least one group. A first control line is in operable communication with the plurality of devices. A second control line in operable communication with the at least one group. A step-advance mechanism is in operable communication with each of the plurality of the devices, each mechanism being distinct from each other mechanism within the group of devices.
Further disclosed herein is a method for reducing the number of control lines needed to control a plurality of downhole devices including supplying a first control line in operable communication with a plurality of devices, the plurality of devices including at least one group of devices and supplying a second control line in operable communication with the at least one group. The method further includes moving the at least one group of devices to a selected position with a step-advance mechanism.
Further disclosed herein is a method for controlling a plurality of devices with two control lines including configuring each device with a distinct step-advance mechanism and alternating pressurization in the control lines to sequentially position the three devices so that following fourteen steps, all possible configurations of the devices have been achieved.
Yet further disclosed herein is a system controlling nine devices with four control lines. The system includes a first control line in operable communication with all nine devices, a second control line in operable communication with a group of three of the devices, a third control line in operable communication with a second group of three of the devices, a fourth control line in operable communication with a third group of three of the devices and each of the nine devices having a step-advance mechanism, and wherein the step-advance mechanisms are distinct within groups.
Yet further disclosed herein is a method for independently controlling a plurality of groups of devices including supplying a number of control lines equal to the number of groups of devices plus 1 control line.
Yet further disclosed herein is a system for controlling a plurality of devices with a reduced number of control lines. The system includes a plurality of devices represented by one or more groups of devices, a number of control lines equal to the number of groups of devices plus one control line.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a schematic illustration of a flow control valve actuation configuration utilizing four control lines and actuating nine flow control devices;
FIG. 2 is a representative schematic view of a J-slot and bearing sleeve laid flat;
FIG. 3 is a schematic view of a J-slot and bearing sleeve arrangement for a first control device in a group;
FIG. 4 is a schematic view of a J-slot and bearing sleeve arrangement for a second control device in a group;
FIG. 5 is a schematic view of a J-slot and bearing sleeve arrangement for a third control device in a group; and
FIG. 6 is a representation of the collective movements of the flow control devices in a nine valve on four line setup.
DETAILED DESCRIPTION
Referring to FIG. 1 , a system is illustrated that provides for remote control of nine individual flow control devices using only four hydraulic control lines. The configuration and operational functionality is facilitated by grouping of flow control devices and through the incorporation of a step-advance mechanism, which may comprise a J-slot and optionally a bearing sleeve in each flow control device. The illustrations and most of this specification are directed to a three device per group arrangement. It is to be understood however that groups of two devices or four devices are also possible and contemplated as within the scope of the invention. In the specifically illustrated embodiment(s) groupings of flow control devices include groups 12 , 14 and 16 . Each group includes three flow control devices 18 , 20 , 22 ; 24 , 26 , 28 ; and 30 , 32 , 34 , each device having two positions, those being closed and open, open and choked or choked and closed. This provides a total number of distinct configurations of two to the third power or eight (2 3 =8). This is represented for clarity in the following table:
Position
Sleeves
1
2
3
4
5
6
7
8
1
O
C
O
C
O
C
O
C
2
O
O
C
C
O
O
C
C
3
O
O
O
O
C
C
C
C
Where O = Open and
C = Closed
Two hydraulic control lines are employed for each group of devices 12 , 14 and 16 as one line is required to actuate the devices to the home position and one line is required to actuate the devices to the second position. For group 12 , these lines are line 36 and line 38 . The reader will note that line 38 is a home line (home position for purposes of this disclosure is the open position of the devices; it will be appreciated however that home could be any predetermined position to which the device will return when actuated in one direction). Home line 38 is shared by all devices in groups 12 , 14 and 16 as illustrated. When line 38 is pressured-up then, all devices of group 12 are actuated and move to the home position. Line 38 and individual lines for groups 14 and 16 , i.e., lines 40 and 42 are not shared between groups but are shared among devices within each group. More specifically, line 38 is shared among devices 18 , 20 and 22 ; line 40 is shared among devices 24 , 26 and 28 ; and line 42 is shared among devices 30 , 32 and 34 . Each of lines 38 , 40 and 42 are “home” actuating lines. Line 36 is common to all devices and actuates to the second (open, choked or closed) position. Each of lines 38 , 40 and 42 independently actuate only the single group with which they are associated.
At this point it is clear that all devices can be moved to the position by line 36 pressure. It is also clear that group 12 devices may all be actuated to the home position by line 38 ; group 14 devices may all be actuated to the home position by line 40 ; and group 16 devices may all be actuated to the home position by line 42 .
If it would be sufficient for a particular application to have each device of each group of devices in the same position (i.e., either open or closed; open or choked; closed or choked), then the system so far described is useful in that nine devices are operable by four control lines.
Since it is not often sufficient in the downhole environment to have a group of devices, for example devices 18 , 20 and 22 , all open or all closed or all choked, but rather is often the case that they would be in different positions, further capability in the groups is desirable. To provide the greater variability of positioning among individual devices of each group of devices 12 , 14 or 16 , each device 18 , 20 , 22 , 24 , 26 , 28 , 30 , 32 and 34 is constructed with a step-advance mechanism comprising such as a J-slot and optionally a bearing sleeve.
Referring to FIG. 2 , a J-slot sleeve 46 has been illustrated cut and laid flat for clarity. One of ordinary skill in the art is familiar with J-slot sleeves, their purpose being to guide a pin during reciprocal movement into advancing slots. In the illustration, a number of slot sections 48 and slot sections 50 are shown. The “J-sections” 52 between each slot section pair 48 / 50 are configured to allow a pin 54 to advance in the J-slot sleeve 46 in only one direction. It will be noted that each slot section 48 is the same length in the figure and each slot section 50 is the same length in the figure. In such configuration, there is no specifically controlled movement of the attached device. It is possible in this invention to use J-slots having different slot section lengths to specifically control movement but this relies on the load holding capability of the pin 54 . In higher load situations, which are anticipated for the devices hereof, a bearing sleeve 60 is employed along with the J-slot sleeve 46 , together making up the step-advance mechanism. The purpose of the bearing sleeve 60 is to create a specific control of motion of the attached device and hold the load thereof. Thus bearing lug 62 is appreciably larger in dimension, and therefore strength, than pin 54 . The bearing sleeve 60 is of a stepped configuration allowing for specific position limiting of the bearing lug 62 .
In this disclosure, an object is to operate multiple flow control devices with few control lines. In the illustrations, which follow, the individual flow control devices utilize only two positions: open and closed, closed and choked or choked and open. The FIG. 2 illustration allows for more variability than that illustrated in the balance of the drawings hereof. Upon exposure to more of this disclosure one skilled in the art will appreciate that more variables could be introduced to the concept hereof by lengthening the circumferential step-advance mechanism path. This is done for example by adding more J-steps (each comprised of slot section 48 / 50 and J-section 52 ) to the sleeve. In such a system, it is possible to add more variability regarding positioning and still allow for sufficient stepping to account for all combinations of possible positions. More or fewer J-slot steps is also relevant to groups of devices containing more of fewer devices. For example, other groups of devices are contemplated herein and include for example two or four devices. In a two device group, the step-advance mechanism would have four total positions yielding four steps of the device (three home positions and three second positions). In a four device group the step-advance mechanism would have thirty positions to account for all combinations of device positions. Alternatively, one or more of the devices could have no step-advance mechanism at all while others in the same group would have a step-advance mechanism. By so configuring the system, more devices are available without requiring an unwieldy number of step-advance mechanism positions. It is to be understood that the number of devices operable by the concept hereof is limited only by the number of control lines allowed. Twenty one devices or more can be controlled, for example. Essentially, the concept hereof is mathematically described as number of control lines equal (number of devices/number of devices per group plus 1).
FIG. 2 illustrates bearing lug 62 in a position away from home (or open) and stopped from further motion by stop 64 of bearing sleeve 60 . A stop such as this is illustrated more schematically in FIGS. 3-5 and is referred to here for the clarity offered by the more detailed drawing. As noted above, the FIG. 2 bearing sleeve provides for variable actuation of a single sleeve. This must be taken into account when considering the following figures and disclosure. Providing this variability in a control line reducing system as set forth herein increases complexity and would require significantly more J-steps to represent each possible interaction. While possible, the number of system pressure-up steps will at some point become unwieldy and outweigh the benefit-ratio of the concept.
Referring to FIGS. 3-5 , schematic illustrations of the J-slot sleeve and bearing sleeve are shown. FIG. 3 relates to device 18 for a one group system; devices 18 and 24 for a two group system; and devices 18 , 24 and 30 for a three group system. FIG. 4 relates similarly to device 20 ; to devices 20 and 26 ; or to devices 20 , 26 and 32 . FIG. 5 relates to device 22 ; to devices 22 and 28 ; or to devices 22 , 28 and 34 . As is now apparent, each device of a group of devices is constructed with a unique bearing sleeve. Because of this, pressuring up on control line 36 may have differing actuation of the three devices in each group. Moving through the various positions of the J-slot sleeve, each group of three devices can be moved through every possible combination of positions.
Still referring to FIGS. 3-5 , the J-slot sleeve representation is of a continuous J-slot with end 56 adjoining end 58 when in tubular configuration. As stated above, the J-slot sleeve portion of this arrangement operates to advance the pin 54 shown in FIG. 2 thereby also advancing the bearing lug 62 shown in FIG. 2 . In FIG. 3 one should appreciate that bearing lug 62 (shown in FIG. 2 ) cannot move leftwardly in the figure at position 12 , 8 and 4 but can so move at position 10 , 6 , 2 and 14 , with position 13 , 11 , 9 , 7 , 5 , 3 and 1 being rightwardly of the figure and unimpeded. These latter positions are the home positions, have in this example being open. The operation of the J-slot and bearing sleeves in FIG. 3 is the same in FIGS. 4 and 5 with stops at distinct positions. The stops in FIG. 4 are at positions 10 , 8 and 2 and for FIG. 5 at positions 6 , 4 and 2 . In each case the stops prevent closure of the associated device when pressure is exerted on line 36 while allowing such closure when stops are not positioned.
In each of the J-slot configurations, fourteen positions are shown. This comports with the two positions to the third power statement made earlier as each valve is stepped back and forth between a home position and a second position. This means that the valves are at the home condition at positions 1 , 3 , 5 , 7 , 9 , 11 and 13 and at second positions, which are dictated by the stops of FIGS. 3-5 for positions, 2 , 4 , 6 , 8 , 10 , 12 and 14 . One will appreciate this and its cyclic implications for combinations of device position in the table below:
Positions
Sleeves
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1, 4&7
H
C
H
O
H
C
H
O
H
C
H
O
H
C
2, 5&8
H
O
H
C
H
C
H
O
H
O
H
C
H
C
3, 6&9
H
O
H
O
H
O
H
C
H
C
H
C
H
C
Positions:
H = Home Position (= Open),
C = Closed,
O = Open
Referring to FIG. 6 , the foregoing tabular operation is illustrated more graphically. A nine valve (device) system is illustrated however it should be understood that this same figure could represent a three or six device configuration identically. The graphical representations each include three broken lines 70 , 72 and 74 . Line 70 represents the home position; line 72 the stopped position and line 74 the closed position. The three graphical representations are specifically aligned from top to bottom to provide an indication of the distinctions of actuation among the three devices in each group. These three graphical representations also relate directly to FIGS. 3-5 . The top most graphical representation 76 relates to FIG. 3 ; the representation 78 to FIG. 4 and the representation 80 to FIG. 5 .
By stepping through all fourteen positions of the illustrated embodiments, each possible combination of binary movement for the three valves in each group is achievable and this control for flow in the well is achieved for three valves with only two control lines; for six valves with only three control lines and for nine valves with only four control lines. As noted above: number of control lines equals (number of devices divided by number of devices per group) plus 1. The system as described significantly reduces the problem of overcrowding of the wellbore with control lines. Moreover, since this system uses only two positions for each valve, no graduated fluid pressure in the control line is necessary. This facilitates non-surface located hydraulic initiators and therefore additional benefit to the art in the form of reduced well head crowding since the lines need not exit the wellbore at all.
In one embodiment utilizing the above-disclosed concept, a surface control system having predictable and controllable volume and/or pressure capability is provided. This provides for automatic compensation of fluid volumes and/or pressures as the devices age. Furthermore, the control system may be operable remotely. The control system may in one embodiment include a programmable logic system.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A control system for a plurality of devices including a plurality of devices in at least one group. A first control line is in operable communication with the plurality of devices. A second control line in operable communication with the at least one group. A step-advance mechanism is in operable communication with each of the plurality of the devices, each mechanism being distinct from each other mechanism within the group of devices. Further disclosed herein is a method for reducing the number of control lines needed to control a plurality of downhole devices including supplying a first control line in operable communication with a plurality of devices including at least one group of devices and supplying a second control line in operable communication with the at least one group. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to an improved process for preparing Guggulsterones. More particularly the present invention relates to a process for preparing a mixture of trans- and cis-4,17 (20) pregnadiene-3,16-dione (Guggulsterone-E and -Z respectively) of the formula Ia and Ib useful as hypolipidemic agent.
BACKGROUND OF THE INVENTION
[0002] The compound of the present invention is known in prior art literature as early as the nineteen seventies in connection with their utility in synthesis of steroidal alkaloids and saponines [S. V. Kessar and A. L. Rampal, Chem Ind., 1957 (1963); Tetrahedron Letters, 4319 (1966). These compounds were later isolated from the resin (gum guggul) obtained from Commiphora mukul which is an important drug in the Ayurvedic system for arthritis and inflammation.
[0003] There is also reference regarding its anti-obesity activity in Charak Sanghita [G. V. Satyavati in Economic and Medicinal Plant Research , Vol. 5 , Plants and Traditional Medicine pp 47 (1991), Academic Press]. After extensive research work on gum-guggul through extractive fractionation followed by bio-evaluation at Central Drug Research Institute, Lucknow jointly with Malti-Chem Research Centre, Baroda, a toxicologically safe extract was standardized for hypolipidemic activity.
[0004] The product is being marketed as ‘Guglip’ by CIPLA Ltd., Bombay. It was simultaneously established in the study that hypolipidemic activity was due to presence of compounds of formula Ia and Ib above to the extent of 4-5% in the product and hence the name guggulsterone was coined to the product I.
[0005] The results of this pioneering work provoked considerable efforts among industries and academia world-over in Guglip and as a result several additional activities were established in the preparation such as prevention of sebum secretion [U.S. Pat. No. 5,6980, 948], anti-inflammatory by Bombardelli et al [U.S. Pat. No. 5,273,747] and use in benign prostate hypertrophy and acne. Bessett et al [U.S. Pat. No. 4,847,071 and 4, 847, 069] and Piazza et al [U.S. Pat. No. 5,521,223] disclosed photo-protective and anti wrinkle actions. Guggulsterone content in gugulipid is highest to the extent of 4-5% and therefore many of the activities of gugulipid have been implicated because of guggulsterone.
[0006] The hypolipidermic activity has already been established. In pursuance of further efforts in synthesis of guggulipid and its constituents, the process of guggulsterone synthesis has been further improved upon.
[0007] Two methods of guggulsterone synthesis are known. The first method is as follows:
[0008] 5,17 (20)-pregnadiene-3,16-diol (Scheme I, compound V) is the key intermediate in the synthesis [WR Benn and RM Dodson, J. Org. Chem. 29, 1142 (1964)]. The reduction of α, β-unsaturated carbony] function of 16-DPA with lithiumaluminumphydride (LAH) yields 5, 16-pregnadiene 3, 20-diol (III) which on catalyzed allylic rearrangement produces the key intermediate IV. The oxidation of IV yields guggulsterone.
[0009] However, the process has many drawbacks. During the process of reduction, a by-product through 1,4-hydride addition is always inevitable (to the extent of 40%) and hence a chromatographic separation is required. The slight impurity of this product will contaminate the final product with progesterone after oxidation on the other hand, use of pyrrophoric and inflammable reagents like LAH and solvent ether at industrial scale is also a cause of reluctance for industrial production [W. R. Benn, J. Org. Chem. 28, 3557 (196)].
[0010] The alternate process is as follows:
[0011] The unsaturated carbonyl function of 16-DPA is converted to 16,17-epozy carbonyl followed by Kishner reduction-elimination under Huang-Minlon condition yields the key intermediate (Scheme 2).
[0012] However, this procedure is also not suitable for large-scale preparation because of simultaneous formation of pyrazone, a by-product in appreciable high yields. The epoxidation with hydrogen peroxide is not reproducible instead a Michael addition product is obtained as a by-product in reported conditions. Also because of the supply of hydrogen peroxide of variable strength, it is difficult to fix the reaction parameters.
OBJECTS OF THE INVENTION
[0013] The main object of the invention is to provide an improved process for the preparation of Guggulsterones which obviates the drawbacks with the prior art enumerated above.
[0014] Another object of the invention is to provide a process using an oxidant, hydrogen peroxide on a solid support, which provide the reagent at the reaction site in high concentrations.
[0015] Yet another object of the invention is to provide a process in which no side product is produced.
SUMMARY OF THE INVENTION
[0016] Accordingly the present invention provides an improved process for the preparation of Guggulsterones which comprises epoxidising 16-dihydropegnenolone acetate (16 DPA) by reacting 16DPA with hydrogen peroxide reagent adduct in the presence of a co-base in a polar solvent to obtain 3 β hydroxy-16 α, 17-oxido-5 pregnen-20-one, converting the 3 βhydroxy-16α, 17-oxido-5-pregnen-20-one by reacting with hydrazine in the presence of a strong base at refluxing temperature followed by oxidation to obtain desired gugguisterones viz. to 5, 17-(20)-cis and trans pregnadiene-3 β, 16-diol of the formula Ia and Ib
[0017] In one embodiment of the invention, the refluxing temperature is in the range of 100-1300° C.
[0018] In another embodiment of the invention the hydrogen peroxide-reagent adduct used is selected from hydrogen peroxide-urea adduct and hydrogen peroxide-sodium carbonate adduct.
[0019] In another embodiment of the invention the co-base is selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide and phase transfer catalyst.
[0020] In yet another embodiment of tie invention the polar solvent is selected from the group consisting of methanol, ethanol and a mixture thereof.
[0021] In a further embodiment of the invention the strong base is selected from the group consisting of trialkylamine, substituted amidine, guanidine potassium tertiarybutaoxide, alkalimetal-hexadimethylsilazane and lithiumdiisopropylamide.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present inventors therefore have made extensive research related to these problems. As a result, we analyzed the reactions very carefully to sort out the problems. The cause of sluggish epoxidation is the low percentage of oxidizing entity. We therefore used hydrogen peroxide on solid support in order to provide the reagent at the reaction site in high concentrations. The analysis of the mechanism of rearrangement reaction is depicted in Scheme III below, which suggest the intermediacy of hydrazone. There are two possible courses of reactions for hydrazone to undergo in subsequent step. In the first mode of reaction, the nucleophilic ring opening by nitrogen will provide pyrazone after aromatization. In the second mode, abstraction of a proton under the basis influence of hydrazine will generate N-anion, which may either stablize itself through resonance to another intermediate diazo or proceed for cyclization. However, it will not go for cyclization mode because in cyclization mode electron pair will rest on oxygen atom whereas in diazo intermediacy mode it will rest on carbon. Since carbon anion is more basis than oxygen anion and hence proton will prefer to stay at carbon anion. The cylization therefore should not prefer. The reaction from B to D is also not possible according to Baldwin's rule of cyclization. Hence, one the proton is abstracted fast, the by-product should not appear.
[0023] However, the abstraction of the first proton by hydrazine base (where N atomii has sp 3 hybridization) from the nitrogen atom of some hybridization (sp 3 ) is not a favourable proposition. As a result both possible modes of reaction operate to yield mixture of products The present invention therefore relates with the use of base of higher pk a value than hydrazine (Δpk a ) for rearrangement of epoxy hydrazone (generated in situ).
[0024] According to the present invention, a process for producing gugulsterone was improved to a large extent and with good efficiency as compared with the process disclosed by Bernn, W. R. et al. in their publication [The synthesis and stereochemistry of isomeric 16-hydroxy-17 (20)-pregnenes, J. Org. Chem. 29: 1142-48 (1963)].
[0025] The compound obtained according to the process of the present invention is very useful as hypolipidemic and antoxidant agent and antioxidant agent. It can also be admixed with guglip and other hypolipidemic agents.
[0026] The following example is given by way of explanation and should not constructed the scope of the invention.
EXAMPLE
[0027] Step 1: Preparation of 16 α, 17-oxido-5-pregnen-20-one of the Formula (VI)
[0028] 16-Dehydropregnenolone acetate (35 g) is suspended in methanol (500 ml). The solution is treated, after cooling to 500° C. with 4N NaOH (8.9 gm in 50 ml H 2 O) followed by immediately with hydrogen peroxide-urea adduct (UHP, 18 g.). The mixture is then stored in the refrigerator at 5° C. for 72 hr. The reaction mixture is shaken intermittently. The reaction mixture is poured into 500 ml of ice water. The product is isolated by centrifugation after wash up with water till neutrality to pH paper. The product is dried (63.0 g, 97%) M.P. 187-90 (187-90°).
[0029] [0029] 1 H-NMR (CDCl 3 ): δ 5.3 (m, 1H, olefinic proton), 3.67 (s, 1 H, C 16 —H), 3.5 (m, 1 H, C 3 —H), 2.0 (s, 3H, CH 3 CO); 1.2 and 1.0 (2s, 3H each, C 18 Me, C 19 Me).
[0030] Step 2: Preparation of 5, 7 (20)-cis and trans pregnadiene- 3 β, -16 -diol of the formula (V).
[0031] A suspension of 3 β-hydroxy-16 α, 17-oxido-5-pregnen-20-one (10 gm) in hydrazine (anhydrous, 100 ml), lithimhexamethyldisilazane (10 ml, 1 Mol Sol) was brought slowly to reflux temperature (100-1200° C.) under stirring and protection of outlet with calcium chloride tube. The reaction was run till evolution of nitrogen (3-4 hrs) and then allowed to cooling to room temperature. The reaction mixture was poured in to ice water and product filtered and dried. Yield (9.0 g, 90%).
[0032] [0032] 1 H-NMR (CDCl 3 ): δ 5.4 (m, 1 H, olefinic H), 4.8 (m, 1 H, olefinic H) 3.5 (m, 1 H, C 3 —H)
[0033] Step 3: Preparation of Guggulsterone of the Formula (Ia,b)
[0034] Diol V on oxidation with known reagents can be converted to the required product guggulstrone. The details are given belowv
[0035] A three neck 2 It. R.B. flask immersed in oil bath, is equipped with nitrogen inlet, mechanical stirrer and condenser with a device to remove some solvent during the course of reaction. The assembly is protected from moisture with calcium chloride guard tube. The flask is then charged with toluene (1200 ml) and started distillation of a portion of toluene in order to dry the system by azeotropic distillation. Then diol (30 g) and cyclohexanone (120 ml) are added to the flask. After an additional 50 μl of toluene has been distilled, aluminium isopropoxide (15 g) is added and toluene is kept on distilling dropwise till the reaction is complete so that about 600 ml of tolune has distilled. An additional 300 ml of tolune is distilled and then reaction is brought to room temperature. 400 ml of a saturated solution of Nak tartarate is added to the mixture and the organic layer becomes clear and orange. The nitrogen inlet is then removed and reaction was steam distilled to remove cyclohexanone. The reaction mixture is then cooled to room temperature and separated oil is extracted with ethyl acetate. Organic solution is then dried (Na 2 SO 4 ) and solvent removed. The residual oil is chromatographed over flash silica gel column using hexane, toluene and ethyl acetate. The yield is 61% white amorphous powder having melting point 150-540° C. | The present invention provides an improved process for the preparation of Guggulsterones which comprises epoxidising 16-dihydropegnenolone acetate (16 DPA) by reacting 16DPA with hydrogen peroxide reagent adduct in the presence of a co-base in a polar solvent to obtain 3 β hydroxy-16 α, 17-oxido-5 pregnen-20-one, converting the 3 β hydroxy-16α, 17-oxido-5-pregnen-20-one by reacting with hydrazine in the presence of a strong base at refluxing temperature followed by oxidation to obtain desired guggulsterones viz. to 5, 17-(20)-cis and trans pregnadiene-3 β, 16-diol of the formula Ia and Ib. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a self-locking safety hook of the kind comprising an arcuate hook body defining a hook opening and a two-arm lever being pivotally journalled at an upper end portion of the hook body, one arm of the lever being provided with a suspension element designed to be coupled to a hoisting means, such as a rope, a chain, a wire, or a hoisting strap, and the other arm of the lever being designed as a closure means for the hook opening, the lever being pivotable between a closed position, in which the closure arm abuts the free end of the hook body so as to close the hook opening, and a fully open position, in which the closure arm is swung away from the free end of the hook body so as to enable the insertion of a load into the inside of the hook body, wherein the closure arm is retained in said closed position when the hook is under load, and the hook is designed to carry the whole load during a lifting operation.
BACKGROUND OF THE INVENTION
[0002] Lifting hooks with various safety arrangements are well-known in the art, the two predominant ones, being illustrated in the appended drawings, FIGS. 1 and 2 .
[0003] FIG. 1 shows a conventional lifting hook with an arcuate hook body 101 which at its upper part is provided with a suspension means in the form a transversal, detachable pin 102 to be coupled to the end link of a hoisting chain (not shown) and a pivotable closure arm 103 . The latter is spring-loaded to a closing position (as shown), where it closes the hook opening 104 and holds a lifting gear represented here by a link 105 (coupled to a load, not shown) securely in place. The arm 103 can be swung against the spring means into an inward position where it keeps the hook opening 104 free and enables insertion of a link 105 or similar into the inside of the hook. As is well-known in the art, the pin 102 can be replaced by a closed eye or a swivel member which is attachable to a hoisting chain, a rope, a wire or a hoisting strap. According to some proposals, see e.g. the Norwegian laid-open print 20013434 (Ekeskog et al) and the Japanese published patent application JP2001253679), a further closure arm is disposed in the hook opening, one being pivotable inwardly and the other being pivotable outwardly in relation to the tip of the hook body. However, such an arrangement is not very practical, since the operator has to manipulate both closure arms manually, which is difficult and somewhat risky.
[0004] FIG. 2 illustrates a self-locking lifting hook of the kind defined in the opening paragraph, including an arcuate hook body 111 with a fork-like upper portion 112 , where a two-arm lever 113 is pivotally journalled on a transverse pin 114 extending between the two shanks of the upper portion 112 .
[0005] The lever 113 comprises an upper arm 115 , provided with a suspension pin 116 (or some other suspension member), and a lower closure arm 117 , which in a loaded situation keeps the hook opening 120 closed so as to retain a link 118 securely in the hook. Often, there is a spring loaded locking mechanism in the upper part 112 of the hook body, which can hold the closure arm either in the closed position (as shown) or in a fully open position.
[0006] In case of the conventional lifting hook according to FIG. 1 , the lifting gear represented by the link 105 can in a non-loaded situation unintentionally swing to a position above the hook tip, see FIG. 1 , where it when loaded or by its own weight can force the closure arm 103 to open, resulting in dropped lifting gear/load.
[0007] The traditional self locking hook according to FIG. 2 withstands the above described risk due to its design having a strong closure arm 117 pivotable outwardly. The self locking hook type remains due to its design always in a closed position as long as it is loaded. The locking mechanism is intended to secure the closure arm 117 in a closed position also in non-loaded situations. However the locking mechanism can unintentionally become released due to a direct hit on the locking mechanism or by momentum of inertia if the hook collides with a hard structure. Alternatively, it may happen that a possible locking mechanism (in the embodiment of FIG. 2 ) becomes inoperable e.g. due to wear, breakage of a spring or for some other reason, resulting in risk of dropping lifting gear/load.
SUMMARY OF THE INVENTION
[0008] Against this background, it is a main object of the invention to provide a self-locking hook with an additional safety feature so as to reduce the risk of unintentional dropping the load from the hook, especially in connection with insertion of the load into the inside of the hook body.
[0009] A further object is to provide a self-locking lifting hook which is easy to handle and operate.
[0010] The main object is achieved for a self-locking lifting hook of the kind identified above, wherein a finger element is pivotably mounted at the upper part of the hook so as to close the hook opening, under the influence of a spring means, irrespective of the pivotal position of the two-armed lever.
[0011] In this way, the safety level is significantly increased, since the finger element will keep the hook opening closed at all times, even when the two-arm lever is opened permanently or temporarily, in particular when handling the hook and the associated lifting gear before a lifting operation.
[0012] The finger element, which can be dimensioned as a relatively light and not very strong component, is preferably pivotably mounted adjacent to the pivot axis of the two-arm lever, either on the hook body itself, or on the closure arm of the lever.
[0013] Various detailed embodiments of the self-locking lifting hook according to the invention are defined in the claims and will appear from the detailed description below.
[0014] The inventive lifting hook will now be described in more detail below, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIGS. 1 and 2 illustrate schematically two prior art lifting hooks;
[0016] FIGS. 3 a , 3 b , 3 c show a self-locking lifting hook according to the invention, in a closed position ( FIG. 3 a ), in an open position ( FIG. 3 b ) where the finger element is obstructing the hook opening, and in a fully open position ( FIG. 3 c ) where the finger element is retracted so as to keep the hook opening free;
[0017] FIGS. 4 a , 4 b , 4 c show a second embodiment of the self-locking lifting hook in corresponding positions as in FIGS. 3 a - 3 c;
[0018] FIGS. 5 a , 5 b , 5 c show a third embodiment of the self-locking lifting hook, likewise in corresponding positions as in FIGS. 3 a - 3 c ; and
[0019] FIGS. 6 a , 6 b , 6 c show a forth embodiment of the self-locking lifting hook, also in corresponding positions as in FIGS. 3 a - 3 c.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] In order to eliminate the drawbacks of prior art hooks, as shown in FIGS. 1 and 2 and as discussed above, the self-locking hook according to the invention is provided with an extra safety measure in the form of a finger element, as illustrated in the drawing FIGS. 3 a - 3 d , 4 a - 4 d , 5 a - 5 d , and 6 a - 6 d.
[0021] In the first embodiment shown in FIGS. 3 a , 3 b and 3 c , the self-locking hook comprises an arcuate hook body 1 , having a free end or tip 2 and an upper fork-like end portion 3 with two parallel shanks (only one, 3 a , is visible in the drawing). A pivot pin 4 extends between the two shanks and is fitted through a corresponding transverse bore of a two-arm lever 5 having an upper arm 6 , provided with a suspension means in the form of a closed eye 7 (for coupling e.g. with a shackle to a lifting chain—not shown) and a closure arm 8 . This closure arm 8 extends all the way down to the tip 2 of the hook body 1 and closes the hook opening 10 effectively in the position shown in FIG. 3 a . Here, the end portion 9 of the closure arm abuts the tip 2 of the hook body 1 .
[0022] The lifting hook is self-locking by way of its structure with the lifting eye 7 and the central supporting point 11 inside the hook body being located on an imaginary lifting axis which is slightly displaced sideways in relation to the central axis of the pivot pin 4 , resulting in a closure force acting on the closure arm during a lifting operation.
[0023] Furthermore, there is a locking mechanism (not visible in the drawings) inside the fork-like upper portion 3 of the hook body, disposed on a transversal pin 12 and cooperating with a cam surface on the closure arm, adjacent to the pivot pin 4 . In this way, the lever 5 can be locked in the closed position of FIG. 3 a or in the open position shown in FIGS. 3 b and 3 c.
[0024] However, when the hook is being handled in preparation of a lifting operation, the lever 5 with its closure arm 8 must be opened so as to enable insertion of an element, such as master link coupled to a number of chain legs, one or more hoisting straps, or the like, into the opening 10 of the hook. Of course, when the closure arm 8 is located in its open position, there is a risk that the load element falls out of the opening 10 . This risk is also present when the closure arm 8 is located in its closed position, as shown in FIG. 1 , in case the latch with the locking mechanism is actuated unintentionally or the locking mechanism fails or becomes inoperative for some reason.
[0025] In order to reduce this risk, the present invention provides for an extra safety measure constituted by a finger element 13 , which is mounted at the upper part of the hook 1 , 5 and which is spring-loaded so as to take a position closing the hook opening 10 with its lower end portion extending towards the tip 2 of the hook body 1 , irrespective of the particular position of the two-arm lever 5 . This is clearly illustrated in FIGS. 3 a and 3 b.
[0026] The spring 14 , exerting a force urging the finger element into abutment with the tip 2 of the hook 1 , can be formed by a steel wire bent around the pivot pin 15 (where the finger is pivotably mounted) and secured with its ends to the closure arm 8 and the finger element 13 , respectively.
[0027] When the load, e.g. a master link or a hoisting strap, is inserted into the hook opening 10 , the finger element 13 is resiliently retracted inwards towards the inside of the hook body, as illustrated by the arrow P in FIG. 3 b and, in its final position, in FIG. 3 c , either manually by the operator handling the lifting gear, or by merely forcing a link or some other component into the opening so as contact the finger element and thereby push it inwardly by way of such a contact.
[0028] In the embodiment of FIGS. 3 a , 3 b , 3 c , the pivot pin 15 is mounted on the lever 5 , adjacent to the pivot 4 on which the lever is journalled. As an alternative, in the modified embodiment illustrated in FIGS. 4 a , 4 b and 4 c , the finger element 23 is mounted on the hook body 1 , at the upper end portion 3 thereof, not far from the pivot pin 4 carrying the lever 5 . The mounting or pivot pin 25 is thus located in the vicinity of the pivot pin 12 carrying the (non-illustrated) latch inside the fork-like upper end portion of the hook body 1 . In this case, the spring 14 , urging the finger element towards the tip 2 , is disposed inside the fork-like end portion 3 of the hook body 1 , and is consequently not visible in FIGS. 4 a - 4 c.
[0029] The rest of the hook, including the hook body, and the lever 5 , is basically the same as in the previous embodiment.
[0030] In FIGS. 5 a , 5 b , 5 c , there is shown a further embodiment, including a finger element 33 which is mounted on the closure arm of the lever 5 , approximately at the same location of the pivot point 35 as in first embodiment. Here, the finger element 33 is extended also upwardly, so as to form a freely projecting end portion 34 . This end portion 34 serves as a gripping element for the operator, so that he/she can manipulate the finger element by manually pushing the end portion 34 in the direction of the arrow P 1 ( FIG. 5 b ), so that the inner part of the finger element swings inwardly towards the hook body 1 and makes the hook opening 10 freely accessible ( FIG. 5 c ). In doing so, the operator does not need to come anywhere near the interior of the hook. Hereby, the operator can manipulate the finger element from the outside of the hook, and the risk of hurting the operator's hand or fingers is thereby substantially reduced.
[0031] Another embodiment, which enables easy and low-risk handling of the hook, is shown in FIGS. 6 a , 6 b , 6 c . The structure of the hook body 1 , the lever 5 and the finger element 13 is the same as in FIGS. 3 a - 3 d . Additionally, there is a flexible pulling member, such as a string 40 with a handle or ring member 41 at the free end thereof. In this case, the operator can easily grip the handle or ring member 41 and pull the string 40 in the direction of the arrows P 2 ( FIGS. 6 b and 6 c ), against the action of the spring member 14 so as to swing the finger element 13 into its position leaving the hook opening 10 free ( FIG. 6 c ).
[0032] As will be understood by those skilled in the art, the lever 5 with its closure arm 8 forms an integral part of the self-locking hook and must be dimensioned so as to carry the load to be lifted. On the other hand, the finger element 13 , 23 and 33 , respectively, is not subjected to any strong forces and can therefore be relatively light-weight and slender. Thus, it is advantageous if it is relatively narrow, so as to occupy as little space as possible in its operative position (as shown in FIG. 3 c , 4 c , 5 c and 6 c ) where it should leave the hook opening 10 freely accessible. Preferably, the closure arm 8 is at least twice as wide as the finger element 13 , 23 , 33 , as measured adjacent to the pivot axis 4 of the lever 5 .
[0033] The finger element 13 etc. should preferably be pivotably mounted rather close to the pivot axis 4 of the lever 5 , so that it can obstruct the opening 10 effectively in its normal rest position, and still be able to clear the opening 10 and be out of the way when it is swung inwards towards the hook body. The length of the finger element should therefore be approximately the same as the length of the closure arm 8 of the lever 5 .
[0034] In the preferred embodiments as shown on the drawings, the free end portion of the hook body 1 has a pointed end 20 , such that the free end portions of the closure arm 8 and the finger element 13 (and 23 , 33 ) can abut the adjacent surface portions on the inside and the outside of the pointed end 20 , respectively. | A self-locking lifting hook is disclosed, of the kind having and arcuate hook body ( 1 ) and an upper, pivotable lever ( 5 ) with one arm forming a suspension means ( 7 ) and a second arm ( 8 ) forming a closure means for the hook opening ( 10 ). A finger element ( 13 ) is pivotably mounted at the upper part of the hook so as to close the hook opening ( 19 ), under the influence of a spring means ( 14 ), irrespective of the pivotal position of the lever ( 5 ) | 5 |
BACKGROUND
[0001] 1. Field of Invention
[0002] Gutter covering systems are known to prevent debris from entering into the open top end of a rain gutter.
[0003] When debris accumulates within the body of a rain gutter in an amount great enough to cover the opening of a downspout-draining hole the draining of water from the rain gutter is impeded or completely stopped. This occurrence will cause the water to rise within the rain gutter and spill over its uppermost front and rear portions. The purpose of a rain gutter: to divert water away from the structure and foundation of a home is thereby circumvented.
[0004] 2. Prior Art
[0005] The invention relates to the field of Gutter Anti-clogging Devices and particularly relates to screens with affixed fine filter membranes, and to devices that employ recessed wells or channels in which filter material may be inserted, affixed to gutters to prevent debris from impeding the desired drainage of water.
[0006] Various gutter anti-clogging devices are known in the art and some are described in issued patents.
[0007] In my U.S. Pat. No. 6,598,352 I teach a gutter protection system for preventing entrance of debris into a rain gutter. I teach a gutter protection system to include a recessed perforated angled well within a rigid main body that receives an insertable flexible polymer support skeleton that supports overlying micro mesh filtering membrane that is attached to the underlying support skeleton. This insertable flexible filtration configuration is manufactured separately from the rigid four or five foot length body in fifty foot rolls and allows for a seamless filter protecting an underlying gutter, over long gutter lengths. The insertable support skeleton includes a perforated plane with integral downward extending planes and integral upward extending support planes, separated by unbroken air space, that contact an overlying micro mesh filtering membrane on it's undermost surface. I further teach that the contacting of the undermost surface of a micromesh filtering membrane by optimally spaced support planes encourages the downward flow of rain water through said micro mesh filtering membrane and into an underlying rain gutter. This gutter protection system has been shown, in the field to be extremely effective at preventing rain gutter clogs without a single known instance of clogging. However, the insertable flexible polymer support skeleton with attached filtering membrane is somewhat heavy and has been found to be cumbersome, even impossible, to install in the recessed angled well of the rigid main body of the gutter protection system during cold weather as the flexible polymer skeleton has been found to stiffen and becomes inflexible. The insertable flexible skeleton also has been known to expand and contract at a different coefficient that rigid main body of the gutter protection system. This can cause areas of the main body of the gutter protection to become exposed to potential debris entrance due to relative shrinkage of the insertable polymer support skeleton or, in other instances, the insertable filtration configuration may expand and extend past the main body of the gutter protection system and further expand past end caps of an underlying gutter which home owners view as undesirable from a cosmetic perspective.
[0008] U.S. Pat. No. 5,557,891 to Albracht teaches a gutter protection system for preventing entrance of debris into a rain gutter. Albracht teaches a gutter protection system to include a single continuous two sided well with angled sides and perforated bottom shelf 9 into which rainwater will flow and empty into the rain gutter below. The well is of a depth, which is capable of receiving a filter mesh material. However, attempts to insert or cover such open channels of “reverse-curve” devices with filter meshes or cloths is known to prevent rainwater from entering the water receiving channels. This occurrence exists because of the tendency of such membranes, (unsupported by a proper skeletal structure), to channel water, by means of water adhesion along the interconnected paths existing in the filter membranes (and in the enclosures they may be contained by or in), past the intended water-receiving channel and to the ground. This occurrence also exists because of the tendency of filter mediums of any present known design or structure to quickly waterproof or clog when inserted into such channels creating even greater channeling of rainwater forward into a spill past an underlying rain gutter. Filtering of such open, recessed, channels existing in Albracht's invention as well as in U.S. Pat. No. 5,010,696, to Knittel, U.S. Pat. No. 2,672,832 to Goetz, U.S. Pat. Nos. 5,459,350, & 5,181,350 to Meckstroth, U.S. Pat. No. 5,491,998 to Hansen, U.S. Pat. No. 4,757,649 to Vahldieck and in similar “reverse-curved” inventions that rely on “reverse-curved” surfaces channeling water into an open channel have been known to disallow entrance of rainwater into the water-receiving channels. Albracht's as well as previous and succeeding similar inventions have therefore notably avoided the utilization of filter insertions. What may appear as a logical anticipation by such inventions at first glance, (inserting of a filter mesh or material into the channel), has been shown to be undesirable and ineffective across a broad spectrum of filtering materials: Employing insertable filters into such inventions has not been found to be a simple matter of anticipation, or design choice of filter medium by those skilled in the arts. Rather, it has proved to be an ineffective option, with any known filter medium, when attempted in the field. Such attempts, in the field, have demonstrated that the filter mediums will eventually require manual cleaning. German Patent 5,905,961 teaches a gutter protection system for preventing the entrance of debris into a rain gutter. The German patent teaches a gutter protection system to include a single continuous two sided well 7 with angled sides and perforated bottom shelf which rainwater will flow and empty into the rain gutter below. The well is recessed beneath and between two solid lateral same plane shelves close to the front of the system for water passage near and nearly level with the front top lip of the gutter. The well is of a depth, which is capable of receiving a filter mesh material. However, for the reasons described in the preceding paragraphs, an ability to attach a medium to an invention, not specifically designed to utilize such a medium, may not result in an effective anticipation by an invention. Rather, the result may be a diminishing of the invention and its improvements as is the case in Albracht's patent U.S. Pat. No. 5,557,891, the German Patent, and similar inventions employing recessed wells or channels between adjoining planes or curvatures.
[0009] U.S. Pat. No. 5,595,027 to Vail teaches a continuous opening 24A between the two top shelves. Vail teaches a gutter protection system having a single continuous well 25 , the well having a depth allowing insertion and retention of filter mesh material 26 (a top portion of the filler mesh material capable of being fully exposed at the holes). Vail does teach a gutter protection system designed to incorporate an insertable filter material into a recessed well. However, Vail notably names and intends the filter medium to be a tangled mesh fiberglass five times the thickness of the invention body. This type of filtration medium, also claimed in U.S. Pat. No. 4,841,686 to Rees, and in prior art currently marketed as FLOW-FREE. TM.
[0010] is known to trap and hold debris within itself which, by design, most filter mediums are intended to do, i.e.: trap and hold debris. Vail's invention does initially prevent some debris from entering an underlying rain gutter but gradually becomes ineffective at channeling water into a rain gutter due to the propensity of their claimed filter mediums to clog with debris. Though Vail's invention embodies an insertable filter, such filter is not readily accessible for cleaning when such cleaning is necessitated. The gutter cover must be removed and uplifted for cleaning and, the filter medium is not easily and readily inserted replaced into its longitudinal containing channel extending three or more feet. It is often noted, in the field, that these and similar inventions hold fast pine needles in great numbers which presents an unsightly appearance as well as create debris dams behind the upwardly extended and trapped pine needles. Such filter meshes and non-woven lofty fiber mesh materials, even when composed of finer micro-porous materials, additionally tend to clog and fill with oak tassels and other smaller organic debris because they are not resting, by design, on a skeletal structure that encourages greater water flow through its overlying filter membrane than exists when such filter meshes or membranes contact planar continuously-connected surfaces. Known filter mediums of larger openings tend to trap and hold debris. Known filter mediums smaller openings clog or “heal over” with pollen and dirt that becomes embedded and remains in the finer micro-porous filter mediums. At present, there has not been found, as a matter of common knowledge or anticipation, an effective water-permeable, non-clogging “medium-of-choice” that can be chosen, in lieu of claimed or illustrated filter mediums in prior art, that is able to overcome the inherent tendencies of any known filter mediums to clog when applied to or inserted within the types of water receiving wells and channels noted in prior art. Vail also discloses that filter mesh material 26 is recessed beneath a planar surface that utilizes perforations in the plane to direct water to the filter medium beneath. Such perforated planar surfaces as utilized by Vail, by Sweers U.S. Pat. No. 5,555,680, by Morin U.S. Pat. No. 5,842,311 and by similar prior art are known to only be partially effective at channeling water downward through the open apertures rather than forward across the body of the invention and to the ground. This occurs because of the principal of water adhesion: rainwater tends to flow around perforations as much as downward through them, and miss the rain gutter entirely. Also, in observing perforated planes such as utilized by Vail and similar inventions (where rainwater experiences its first contact with a perforated plane) it is apparent that they present much surface area impervious to downward water flow disallowing such inventions from receiving much of the rainwater contacting them. A simple design choice or anticipation of multiplying the perforations can result in a weakened body subject to deformity when exposed to the weight of snow and/or debris or when, in the case of polymer bodies, exposed to summer temperatures and sunlight.
[0011] U.S. Pat. No. 4,841,686 to Rees teaches an improvement for rain gutters comprising a filter attachment, which is constructed to fit over the open end of a gutter. The filter attachment comprised an elongated screen to the underside of which is clamped a fibrous material such as fiberglass. Rees teaches in the Background of The Invention that many devices, such as slotted or perforated metal sheets, or screens of wire or other material, or plastic foam, have been used in prior art to cover the open tops of gutters to filter out foreign material. He states that success with such devices has been limited because small debris and pine needles still may enter through them into a rain gutter and clog its downspout opening and or lodge in and clog the devices themselves. Rees teaches that his use of a finer opening tangled fiberglass filter sandwiched between two lateral screens will eliminate such clogging of the device by smaller debris. However, in practice it is known that such devices as is disclosed by Rees are only partially effective at shedding debris while channeling rainwater into an underlying gutter. Shingle oil leaching off of certain roof coverings, pollen, dust, dirt, and other fine debris are known to “heal over” such devices clogging and/or effectively “water-proofing” them and necessitate the manual cleaning they seek to eliminate. (If not because of the larger debris, because of the fine debris and pollutants). Additionally, again as with other prior art that seeks to employ filter medium screening of debris; the filter medium utilized by Rees rests on an inter-connected planar surface which provides non-broken continuous paths over and under which water will flow, by means of water adhesion, to the front of a gutter and spill to the ground rather than drop downward into an underlying rain gutter. Whether filter medium is “sandwiched” between perforated planes or screens as in Rees' invention, or such filter medium exists below perforated planes or screens and is contained in a well or channel, water will tend to flow forward along continuous paths through cur as well as downward into an underlying rain gutter achieving less than desirable water-channeling into a rain gutter.
[0012] U.S. Pat. No 5,956,904 to Gentry teaches a first fine screen having mesh openings affixed to an underlying screen of larger openings. Both screens are elastically deformable to permit a user to compress the invention for insertion into a rain gutter. Gentry, as Rees, recognizes the inability of prior art to prevent entrance of finer debris into a rain gutter, and Gentry, as Rees, relies on a much finer screen mesh than is employed by prior art to achieve prevention of finer debris entrance into a rain gutter. In both the Gentry and Rees prior art, and their improvements over less effective filter mediums of previous prior art, it becomes apparent that anticipation of improved filter medium or configurations is not viewed as a matter of simple anticipation of prior art which has, or could, employ filter medium. It becomes apparent that improved filtering methods may be viewed as patenable unique inventions in and of themselves and not necessarily an anticipation or matter of design choice of a better filter medium or method being applied to or substituted within prior art that does or could employ filter medium. However, though Rees and Gentry did achieve finer filtration over filter medium utilized in prior art, their inventions also exhibit a tendency to channel water past an underlying gutter and/or to heal over with finer dirt, pollen, and other pollutants and clog thereby requiring manual cleaning. Additionally, when filter medium is applied to or rested upon planar perforated or screen meshed surfaces, there is a notable tendency for the underlying perforated plane or screen to channel water past the gutter where it will then spill to the ground. It has also been noted that prior art listed herein exhibits a tendency to allow filter cloth mediums to sag into the opening of their underlying supporting structures. To compensate for forward channeling of water, prior art embodies open apertures spaced too distantly, or allows the apertures themselves to encompass too large an area, thereby allowing the sagging of overlying filter membranes and cloths. Such sagging creates pockets wherein debris tends to settle and enmesh.
[0013] U.S. Pat. No. 3,855,132 to Dugan teaches a porous solid material which is installed in the gutter to form an upper barrier surface (against debris entrance into a rain gutter). Though Dugan anticipates that any debris gathered on the upper barrier surface will dry and blow away, that is not always the case with this or similar devices. In practice, such devices are known to “heal over” with pollen, oil, and other pollutants and effectively waterproof or clog the device rendering it ineffective in that they prevent both debris and water from entering a rain gutter. Pollen may actually cement debris to the top surface of such devices and fail to allow wash-off even after repeated rains. U.S. Pat. No. 4,949,514 to Weller sought to present more water receiving top surface of a similar solid porous device by undulating the top surface but, in fact, effectively created debris “traps” with the peak and valley undulation. As with other prior art, such devices may work effectively for a period of time but tend to eventually channel water past a rain gutter, due to eventual clogging of the device itself.
[0014] There are several commercial filtering products designed to prevent foreign matter buildup in gutters. For example the FLOW-FREE.TM gutter protection system sold by DCI of Clifton Heights, Pa. Comprises a 0.75-inch thick nylon mesh material designed to fit within 5-inch K type gutters to seal the gutters and downspout systems from debris and snow buildup. The FLOW-FREE. TM device fits over the hanging brackets of the gutters and one side extends to the bottom of the gutter to prevent the collapse into the gutter. However, as in other filtering attempts, shingle material and pine needles can become trapped in the coarse nylon mesh and must be periodically cleaned.
[0015] U.S. Pat. No. 6,134,843 to Tregear teaches a gutter device that has an elongated matting having a plurality of open cones arranged in transverse and longitudinal rows, the base of the cones defining a lower first plane and the apexes of the cones defining an upper second plane. Although the Tregear device overcomes the eventual trapping of larger debris within a filtering mesh composed of fabric sufficiently smooth to prevent the trapping of debris he notes in prior art, the Tregear device tends to eventually allow pollen, oil which may leach from asphalt shingles, oak tassels, and finer seeds and debris to coat and heal over a top-most matting screen it employs to disallow larger debris from becoming entangled in the larger aperatured filtering medium it covers. Tregear indicates that filtered configurations such as a commercially available attic ventilation system known as Roll Vent. TM. manufactured by Benjamin Obdyke, Inc. Warminster, Pa. Is suitable, with modifications that accommodate its fitting into a rain gutter. However, such a device has been noted, even in its original intended application, to require cleaning (as do most attic screens and filters) to remove dust, dirt, and pollen that combine with moisture to form adhesive coatings that can scum or heal over such attic filters. Filtering mediums (exhibiting tightly woven, knitted, or tangled mesh threads to achieve density or “smoothness”) employed by Tregear and other prior art have been unable to achieve imperviousness to waterproofing and clogging effects caused by a healing or pasting over of such surfaces by pollen, fine dirt, scum, oils, and air and water pollutants. Additionally, referring again to Tregear's device, a lower first plane tends to channel water toward the front lip of a rain gutter, rather than allowing it's free passage downward, and allow the feeding and spilling of water up and over the front lip of a rain gutter by means of water-adhesion channels created in the lower first plane.
[0016] Prior art has employed filter cloths over underlying mesh, screens, cones, longitudinal rods, however such prior art has eventually been realized as unable to prevent an eventual clogging of their finer filtering membranes by pollen, dirt, oak tassels, and finer debris. Such prior art has been noted to succumb to eventual clogging by the healing over of debris which adheres itself to surfaces when intermingled with organic oils, oily pollen, and shingle oil that act as an adhesive. The hoped for cleaning of leaves, pine needles, seed pods and other debris by water flow or wind, envisioned by Tregear and other prior art, is often not realized due to their adherence to surfaces by pollen, oils, pollutants, and silica dusts and water mists. The cleaning of adhesive oils, fine dirt, and particularly of the scum and paste formed by pollen and silica dust (common in many soil types) by flowing water or wind is almost never realized in prior art.
[0017] Prior art that has relied on reverse curved surfaces channeling water inside a rain gutter due to surface tension, of varied configurations and pluralities, arranged longitudinally, have been noted to lose their surface tension feature as pollen, oil, scum, Eventually adhere to them. Additionally, multi-channeled embodiments of longitudinal reverse curve prior art have been noted to allow their water receiving channels to become packed with pine needles, oak tassels, other debris, and eventually clog disallowing the free passage of water into a rain gutter. Examples of such prior art are seen in the commercial product GUTTER HELMET.RTM. manufactured by American metal products and sold by Mr. Fix It of Richmond, Va. In this and similar Commercial products, dirt and mildew build up on the bull-nose of the curve preventing water from entering the gutter. Also ENGLERT'S LEAFGUARD. RTM. Manufactured and entering the gutter. Also ENGLERT'S LEAFGUARD. RTM. Manufactured and distributed by Englert Inc. of Perthamboy N.J. and K-GUARD. RTM. Manufactured and distributed by KNUDSON INC. of Colorado are similarly noted to lose their water-channeling properties due to dirt buildup. These commercial products state such, in literature to homeowners that advises them on the proper method of cleaning and maintaining their products.
[0018] With the exception of U.S. Pat. No. 6,598,352, none of these above-described systems keep all debris out of a gutter system allowing water alone to enter, for an extended length of time. Some allow lodging and embedding of pine needles and other debris is able to occur within their open water receiving areas causing them to channel water past a rain gutter. Others allow such debris to enter and clog a rain gutter's downspout opening. Still others, particularly those employing filter membranes, succumb to a paste and or scum-like healing over and clogging of their filtration membranes over time rendering them unable to channel water into a rain gutter. Pollen and silica dirt, particularly, are noted to cement even larger debris to the filter, screen, mesh, perforated opening, and/or reverse curved surfaces of prior art, adhering debris to prior art in a manner that was not envisioned. My earlier patent has proven effective but may exhibit undesirable cosmetic features and may prove difficult, even impossible, to install under certain cold weather conditions.
[0019] Accordingly, it is an object of the present invention to provide a gutter shield that employs the effective properties of my U.S. Pat. No. 6,598,352: a gutter shield device that employs a fine filtration combination that is not subject to gumming or healing over by pollen, silica dust, oils, and other very fine debris, a gutter shield device that provides a filtration configuration and encompassing body that eliminates any forward channeling of rain water, a gutter shield that will accept more water run-off into a five inch K-style rain gutter than such a gutter's downspout opening is able to drain before allowing the rain gutter to overflow (in instances where a single three-inch by five-inch downspout is installed to service 600 square feet of roofing surface).
[0020] Another object of the present invention is to provide a gutter shield with the above noted properties that incorporates and makes integral within it's main rigid body the features and structure of the insertable flexible polymer support skeleton disclosed in my U.S. Pat. No. 6,598,352 thereby eliminating the most prominent expansion and contraction coefficients found to exist between a rigid main body utilizing an insertable flexible polymer filtration configuration.
[0021] Another object of the present invention is to provide a gutter shield with the above noted properties that utilizes a stainless steel or aluminum micromesh filter cloth that may be inserted into a main body with integral recessed and perforated wells that incorporate integral upward extending planes allowing for a lower cost of manufacture by eliminating a separately manufactured flexible polymer support skeleton and allowing for a lighter, more stable under varying temperatures, and more easily installed insertable filtering component.
[0022] Another object of the present invention is to provide a gutter shield that employs a filtration membrane that is readily accessible and easily replaceable if such membrane is damaged by nature or accident.
[0023] Other objects will appear hereinafter.
SUMMARY
[0024] It has now been discovered that the above and other objects of the present invention may be accomplished in the following manner. Specifically, the present invention provides a gutter shield for use with gutters having an elongated opening. Normally the gutters are attached to or suspended from a building.
[0025] The gutter shield device comprises an extruded polymer or roll formed metallic uni-body of an angled first plane that extends outward from the front top lip of a rain gutter and that adjoins a second horizontal plane that rests on the top front lip of a rain gutter.
[0026] The second plane adjoins a third plane, that angles upward, by means of a downward extending u-shaped channel that exists on the underside of the rear edge of said second plane.
[0027] The first plane, second plane, and downward extending u-shaped channel serve as a front fastening configuration that secures the forward most area of the main body of the present invention to the top front lip of a k style rain gutter.
[0028] The third upward angled plane adjoins, by means of a second u-shaped channel that is present beneath and parallel to it, a fourth multi-leveled perforated plane that is parallel to and below the third plane. The second u-shaped channel serves as a receiving channel for the lateral edge of a filtration membrane. A portion of the fourth plane that lies parallel and directly beneath the third plane serves as a wall of the receiving channel.
[0029] The fourth plane is perforated and contains intrinsic multiple vertical planes that intersect the fourth plane rising upward and downward. These vertical planes serve to break the forward flow of water over and through a filtration membrane and direct it downward onto themselves at the points of contact existing between the vertical planes and the underside of the filtration membrane. The intersecting vertical planes existing in the fourth plane further direct water flow downward through the perforations of the underlying fourth plane into an underlying rain gutter.
[0030] The fourth plane adjoins a fifth plane by means of a third u shaped channel. The third u shaped channel serves as a receiving channel for the lateral edge of a filtration membrane.
[0031] The fifth plane is parallel to and above the fourth plane and serves as a rear securing member of the present invention that inserts beneath a roofing membrane of a building structure.
[0032] A filtration configuration is inserted in receiving channels present in the body of the gutter shield device. The filter configuration is comprised of small stainless steel or aluminum wire threads that are crimp woven into a wire cloth that contains a minimum of 100 wire threads per square inch which exhibit open air spaces of less than or equal to 100 microns between threads.
[0033] The gutter shield body may be inserted into and secured in a rain gutter by common methods now recognized as public domain. The filtration configuration is slid into u-shaped receiving channels. The receiving channels secure and position the filtration configuration to contact upward extending planes present in plane four.
OBJECTS AND ADVANTAGES
[0034] An object of the present invention is to provide a gutter shield device that exhibits properties disclosed in U.S. Pat. No. 6,598,352 titled “Self Cleaning Gutter Shield”. These properties include:
1. employing a fine filtration combination that is not subject to gumming or healing over by pollen, silica dust, oils, and other very fine debris 2. providing a filtration configuration that prevents the entrance of debris larger than 100 microns from entering any area of a k-style gutter 3. providing a filtration configuration that eliminates the forward channeling of water past an underlying rain gutter to a greater degree than has been exhibited in prior art 4. providing a filtration configuration that remains water permeable and water directing regardless of the type or amount of organic debris that may rest upon it
[0039] Another object of the present invention is to provide the above listed properties in an embodiment that incorporates an insertable skeletal structure that is separate from the main gutter shield body, disclosed in U.S. Pat. No. 6,598,352, into the main body of the present invention. This will lessen product weight, material and shipping costs, eliminate a secondary manufacturing step of sewing filtration membrane to a separate insertable skeletal structure, and allow for a more readily installed gutter shield.
[0040] Another object of the present invention is to provide the above listed properties, previously accomplished in part by utilizing polymer warp-knit fabrics, in a more stable filtration membrane. This is accomplished in the present invention by utilizing a metallic crimp-woven cloth that is less subject to decomposition while exhibiting similar properties to those noted in the filtration medium disclosed in U.S. Pat. No. 6,598,352.
THE DRAWINGS
[0041] FIG. 1 . is a sectional edge view displaying the profile of the main body of the present invention as it would appear extruding from a roll forming machine or plastic extrusion die.
[0042] FIG. 2 . is a sectional edge view displaying the profile of the main body of the present invention enlarged 150%.
[0043] FIG. 3 . is an isolated view of the profile of the main body of the present invention enlarged 400%.
[0044] FIG. 3 a . is an isolated view of the profile of the main body of the present invention enlarged 400%.
[0045] FIG. 4 . is a partial top perspective view of the main body of the present invention.
[0046] FIG. 5 . is an isolated view of a filter medium which affixes to the main body of the present invention or which is inserted into filter medium receiving channels of the present invention.
[0047] FIG. 5 a . is an isolated and exploded view of the filter medium FIG. 6 . is a partial top perspective view of the preferred embodiment of the present invention displaying the main body of the gutter cover with inserted filter medium.
[0048] FIG. 7 . is a partial top perspective view of the present invention, reduced 45%, displaying a roofline portion of a building structure, roof shingles, K-style gutter, and attached gutter cover.
[0049] FIG. 8 . is a sectional edge view displaying an alternate embodiment of the profile of the main body of the present invention as it would appear extruding from a roll forming machine or plastic extrusion die.
[0050] FIG. 9 . is a partial top perspective view of an optional joining member that may be inserted into an alternate embodiment of the main body of the present invention.
[0051] FIG. 10 . is a partial top perspective view of an alternate embodiment of the main body of the present invention.
[0052] FIG. 11 . is a partial top perspective view displaying a joining member inserted into an alternate embodiment of the main body of the present invention prior to being joined to a second section of gutter cover.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Sub-Heading 1
Main Body
[0053] Referring now specifically to the drawings, a gutter cover (protector) body 69 with intrinsic with an insertable metallic micro mesh filtering membrane 71 is illustrated in FIG. 6 .
[0054] 69 , as a polymer body, is composed of poly vinyl chloride (PVC) that is reduced to liquid form through screw compression of PVC “tags”. This liquid plastic mixture is then extruded through a profile forming die, then through a cooling tray and cut to 5 foot lengths. The extruded body material is rigid and has a thickness of approximately 0.06 inch. The extruded body 69 has intrinsic channels 22 and 65 that receive an insertable 120 “thread count” stainless steel wire cloth 71 with hemmed lateral edges and having a width of 3 and 5/8 inches. 69 , as a metallic body is roll-formed from 0.019 to 0.027 aluminum coil slit to widths of 11 3/4 inches and greater; depending on the width of gutter the present invention is to installed upon.
[0055] Referring to FIG. 1 , a profile of the main body 69 of the present invention is illustrated having five major interconnected planes, M 1 ( 3 ), M 2 ( 5 ), M 3 ( 11 ), M 4 ( 23 ev ), M 5 ( 66 ) with a width that may vary between 5.4 and 7 inches (illustrated at 5.4 inches wide) and a height 69 a , measured from the lowest point of channel 55 c to the uppermost point of angle 4 , of approximately 0.67 inch.
Sub-Heading 1a
Front Fastening Member
[0056] Referring to FIG. 2 , plane 1 is extruded or roll formed to a length of approximately 0.11 inch. Adjoining plane 1 is circumference 2 which is extruded or roll formed to an outside diameter of approximately 0.06 inch. Adjoining circumference 2 is plane 3 having a length of approximately 0.53 inch. Plane 3 adjoins and angles 4 approximately 60 degrees downward from horizontal plane 5 . Plane 5 has an approximate length of 0.5 inch and extrudes or roll forms downward at an approximate 96 degree angle 4 a to form downward extending plane or channel 9 which is formed by plane 6 , circumference 7 , and plane 8 .
[0057] In its roll formed metallic state, 6 , 7 , and 8 , form a downward extending u-shaped channel 9 with an open air space existing between planes 6 and 8 of approximately 0.022 inch. In its roll formed metallic state, plane 6 has a length of approximately 0.49 inch, plane 8 has a length of approximately 0.42 inch and circumference 7 has an outside diameter of approximately 0.06 inch. When the present invention is formed as an extruded polymer product, 9 is non-existent and planes 6 and 8 are combined integrally and may be thought of as singular plane 6 / 8 with 7 existing as a termination of the downward extension of 9 .
[0058] The combination of 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 of the present invention in its roll formed metallic state, or the combination of 1 , 2 , 3 , 4 , 5 , 6 / 8 , 7 of the present invention in its extruded polymer state, forms a front fastening member of the present invention that secures it to the top front lip of a k-style gutter.
Sub-Heading 1b
First Filtration Membrane Receiving Channel
[0059] Referring to FIG. 3 , which is an exploded view of FIG. 2 : 22 ev , plane 11 adjoins and angles rearward (toward the rear of the present invention) and upward from plane 8 approximately 30 degrees forming an angle 10 between planes 8 and 11 of approximately 60 degrees. Plane 11 has an approximate length of 0.44 inch. Plane 11 , in a roll formed metallic embodiment of the present invention, adjoins circumference 12 which curves downward into plane 13 that lies directly beneath and parallel to plane 11 . In this roll formed metallic state, plane circumference 12 has an approximate outside diameter of 0.06 inch. and plane 13 has an approximate length of 0.44 inch. When the present invention is formed as an extruded polymer product plane 11 and plane 13 combine integrally and may be thought of as singular plane 11 / 13 with 11 being the topmost surface and 13 the undersurface of 11 / 13 and circumference 12 exists as a termination point rather than as a circumference. 13 , as a separate plane in the metallic roll formed state of the present invention, adjoins downward curving circumference 14 . Similarly, 11 / 13 , as a singular plane in the extruded polymer state of the present invention, adjoins downward curving circumference 14 .
[0060] Circumference 14 has an outside diameter of approximately 0.075 and adjoins plane 15 which is parallel to plane 13 (or plane 11 / 13 ). Plane 15 has an approximate length of 0.17 inch. Plane 15 adjoins plane 16 which has an approximate length of 0.045 inch and angles downward approximately 90 degrees from plane 15 . Plane 16 angles rightward and upward at an approximate 90 degree angle and adjoins plane 17 . Plane 17 has an approximate length of 0.157 inch and adjoins upward angling plane 18 at an approximate 90 degrees. Plane 18 has an approximate length of 0.045 inch and adjoins plane 20 at an approximate 90 degree angle. Plane 20 has an approximate length of 0.10 inch. Planes 16 , 17 , and 18 form a recessed well 19 shown to serve as a perforated water receiving well in FIG. 4 : 17 .
[0061] Plane 11 , circumference 12 , plane 13 (or plane 11 / 13 ), circumference 14 , planes 15 , 16 , 17 , 18 , and 20 form a u-shaped receiving channel 22 with an approximate width 22 w of 0.48 inch and an approximate height 22 h of 0.056 measured from 13 to 20 This receiving channel is illustrated and referred to, collectively, as 22 as illustrated in FIG. 6 :22. FIG. 6 further illustrates that the present invention employs a second receiving channel 6 : 65 that serves, with 6:62 to receive and secure filtering membrane 6 : 71 . The structure and dimensions of receiving channel 65 are illustrated later in this disclosure.
Sub-Heading 1c
Multilevel Water Receiving Area
[0062] FIG. 2 : 22 ev illustrates a multilevel water receiving area of the present invention. Referring to FIG. 3 a , which is an exploded view of a portion of FIG. 2 : 23 ev , plane 20 is formed or extruded at an approximate 90 degree downward angle into plane 21 . Plane 21 has an approximate length of 0.045 inch and is extruded or roll formed rearward into plane 23 . Plane 23 is perforated, as is illustrated in FIG. 4 : 70 with elliptical perforations approximately 0.09 in wide, 0.38 inches long, and spaced longitudinally at approximately 0.15 inch intervals. As a profiled illustration, plane 23 has an approximate length of 0.154 inch and is extruded or roll formed upward at an approximate 90 degree angle into plane 24 . Plane 24 is roll formed or extruded upward approximately 0.045 inch then further roll formed or extruded into partial ellipse 24 e . Planes 21 , 23 , 24 jointly form a water receiving perforated well or channel 25 , (further illustrated in FIG. 4 : 23 ), that has an approximate height 25 h of 0.06 inch and an approximate interior width 25 w of 0.15 inch. measured from the inner wall of plane 21 to the inner wall of plane 24 .
[0063] Partial ellipse 24 e has an approximate partial circumference of 0.03 inch. Partial ellipse 24 e is roll formed or extruded into plane 26 which, if extended, parallels plane 23 . Plane 26 has an approximate length of 0.076 inch. and is roll formed or extruded downward into partial ellipse 27 e . Partial ellipse 24 e , plane 26 , and plane 27 e jointly form an ellipsed cap 28 that contacts the underside of an overlying filtration membrane 64 (as illustrated in FIG. 6 ). Ellipsed cap 28 has an approximate length of 0.16 inch measured from the initial point of partial ellipse 24 e , through plane 26 , to the termination point of partial ellipse 27 e . Partial ellipse 27 e is roll formed or extruded downward into plane 27 which parallels plane 24 . Plane 27 has an approximate length of 0.045 inch.
Sub-Heading 1c1
Water Directing Bumps
[0064] Referring again to FIG. 3 a : plane 24 , partial ellipse 24 e , plane 26 , partial ellipse 27 e , and plane 27 jointly form a “bump” 29 that extends upward and supports and contacts the underside of an overlying filtration membrane 71 , (as illustrated in FIG. 6 ) that rests on the ellipsed cap 28 integral to bump 29 . Bump 29 has an approximate height 29 h of 0.068 inch and an approximate width 29 w of 0.13 inch. Referring again to FIG. 2 and FIG. 3 a , “Bumps” 36 , 43 , 48 , 51 ,and 59 and their respective integral caps 35 , 42 , 47 , 50 , and 58 existent in the multi-level water receiving well of the present invention have measurements identical to bump 29 and its respective integral cap 28 as illustrated in FIG. 3 a.
[0065] Referring again to both FIG. 2 and FIG. 3 a , Bumps 43 and 54 with their respective integral caps 42 and 53 also have measurements identical to bump 29 and its respective integral cap 28 with the exception of their rear most downward extending legs 41 and 55 respectively. These legs each have an approximate length of 0.25 inch and serve to form a wall of downward extending channels 44 and 56 respectively as well as act as a supporting plane for the respective bumps they exist in.
Sub-Heading 1c2
Water Receiving Perforated Wells
[0066] Referring again to FIG. 3 a , as previously described: partial ellipse 27 e extends downward into plane 27 which further extends at a 90 degree angle into plane 30 . As a profiled illustration, plane 30 has an approximate length of 0.154 inch. Plane 30 is perforated, as is illustrated in FIG. 4 : 70 with elliptical perforations approximately 0.09 in wide, 0.38 inches long, and spaced longitudinally at approximately 0.15 inch intervals. Plane 30 extends upward at an approximate 90 degree right angle into plane 31 . Plane 31 parallels plane 27 and has an approximate length of 0.045 inch. Plane 31 extends upward into partially ellipsed plane 31 e . Partially ellipsed plane 31 e has an approximate partial circumference of 0.03 inch. partial ellipse 27 e , plane 27 , plane 30 , plane 31 , and partial ellipse 31 e jointly form perforated well 32 .
[0067] Wells 39 , 49 , and 52 existent in the multi-level water receiving well of the present invention have measurements identical to well 32 of the present invention. The dimensions of wells 22 and 24 have been previously described in this disclosure.
[0068] Referring again to FIG. 2 : 23 ev , wells 46 and 57 incorporate two downward extending planes or channels 44 and 56 respectively which differentiates them from other perforated wells existent in the present invention. Wells 46 and 57 have identical measurements as do their respective channels 41 c and 55 c.
[0069] Well 46 is jointly formed by ellipse 43 e , plane 41 , circumference 41 c , plane 41 d , plane 45 , plane 45 a and partial ellipse 45 e . Partial Ellipse 43 e has an approximate partial circumference of 0.03 inch and extends downward into plane 41 which parallels plane 38 . Plane 41 has an approximate length of 0.28 inch and extends into circumference 41 c . Circumference 41 c has an approximate outside diameter of 0.06 inch. Circumference 41 c extends upward into plane 41 d . Plane 41 d has an approximate length of 0.23 inch. Plane 41 d extends into or joins plane 45 at an approximate 90 degree angle. Plane 45 has an approximate length of 0.13 inch. Plane 45 extends upward into partial ellipse 45 e which has an approximate partial circumference of 0.03 inch. As mentioned earlier, well 57 has measurements identical to those of well 46 .
[0070] Plane 41 , circumference 41 c , and plane 41 d within well 46 additionally jointly form channel 44 which has an approximate height 43 h of 0.24 inch and an approximate width 44 w of 0.03 inch. As mentioned earlier, channel 55 c within well 57 has measurements identical to those of channel 44 .
[0071] Referring again to FIG. 2 : 23 ev , 59 d has an approximate length of 0.045 inch and extends into plane 60 a . 60 a has an approximate length of 0.154 inch and extends upward at an approximate 90 degree angle into plane 61 . Plane 61 has an approximate length of 0.045 inch. Plane 59 d , plane 60 a and plane 61 jointly form perforated well 60 .
Sub-Heading 1d
Second Filtration Membrane Receiving Channel
[0072] Referring again to FIG. 2 , plane 61 extends at an approximate 90 degree angle into plane 62 which serves as the bottom shelf of receiving channel 65 and has an approximate length of 0.44 inch. Plane 62 extends upward into partial circumference 63 which has an approximate outside diameter of 0.05 inch. Partial circumference 63 extends into plane 64 which serves as the top shelf of receiving channel 65 and has an approximate length of 0.4 inch. Plane 62 , partial circumference 63 , and plane 64 jointly form the second receiving channel of the present invention which serves to receive and secure a lateral edge of the filtration membrane 71 as illustrated in FIG. 6 .
Sub-Heading 1e
Rear Shelf
[0073] Plane 64 extends upward into partial circumference 66 . Partial circumference 66 has an approximate outside diameter of 0.05 inch and extends rearward into plane 66 . Plane 66 has an approximate length of 1.55 inch. 66 extends downward into partial circumference 67 which has an approximate outside diameter of 0.06 inch. Partial circumference 67 extends into plane 68 which has an approximate length of 0.11 inch.
Sub-Heading 2
Metallic Cloth Filtration Membrane
[0074] Referring to FIGS. 5 and 5 a , there is illustrated in 71 a metallic filtering membrane composed of stainless steel threads. This filtering membrane is commonly referred to as “wire cloth” and is presently employed as a screening debris filter in the manufacture of plastics and as a filtering component of industrial mufflers. The diameter of metallic threads may range from 10 to 30 mm and be crimp woven in meshes from 100 to 150 mesh (thread counts per inch).
[0075] Referring to FIG. 5 it is illustrated that the filtering cloth 71 has its lateral edges folded over or hemmed 71 a to eliminate sharp cutting edges often noted in wire cloth.
[0076] Referring to FIG. 6 it is illustrated that filtering cloth 71 is inserted into the body of the present invention and held in place by channels 22 and 65 . In the field it has been noted that filtering cloth 71 will not be dislodged by wind due to the natural stiffness present in wire cloths of 120 mesh or less.
Operation of the Main Embodiment
Flow Screen
[0077] Referring to FIG. 6 , there is illustrated the present invention: a gutter protection system that consists of a main body 69 with integral filtration membrane receiving channels 22 and 65 enveloping the lateral edges of an insertable filtration membrane 71 that overlies a multi level supporting skeleton of perforated planes, non perforated planes, upward extending nodes and downward extending planes collectively noted as 23 ev.
[0078] The main body, 69 , of the present invention is presently manufactured and marketed as an extruded polymer: Leaffilter RTM, and the body is presently manufactured as roll formed aluminum product: Flow Screen RTM. presently in a testing stage and not yet offered for sale as of the time of this patent application. 69 , as a polymer body is composed of poly vinyl chloride (PVC) that is reduced to liquid form through screw compression of PVC “tags”. This liquid plastic mixture is then extruded through a profile forming die, then through a cooling tray and cut to 5 foot lengths. This length has proven ideal for installation by one individual in that its length is short enough to be readily handled and accessed while allowing for as few joints or seams as possible to exist between adjoining body members of the present invention when it is installed over the length of a rain gutter. The extruded material is rigid and has a thickness of approximately 0.06 inch. The extruded material has proven, in the field, to be suitably thick to maintain its shape and not deform or dip under load bearing weight of snow and ice or deform when exposed to high ambient temperatures which have caused prior art of lesser thickness to deform vertically upwards and downwards allowing open-air gaps to form from one piece op prior art to the next when the rest abutted side by side. These gaps may allow debris entrance into a gutter.
[0079] Referring to FIG. 7 , the present invention is illustrated as inserted into the top water receiving opening of a k-style rain gutter 72 and resting on the front top lip 73 of the k-style rain gutter and resting on a sub-roof 68 of a building structure. The present invention is secured to the underlying rain gutter 75 by the encompassing of the front top lip 73 of the rain gutter by planes 3 , 5 , and 6 of the present invention and further secured by the insertion of plane 66 of the present invention beneath roof shingles 74 .
Sub-Heading 1
Water Receiving Area of the Main Body
[0080] Once this is accomplished, main body 69 offers improvement over prior art as follows: As noted in U.S. Pat. No. 6,598,352: “Perforated surfaces existing in a single plane, such as are employed in U.S. Pat. No. 5,595,027 to Vail, or as exists in the Commercial Product SHEERFLOW.RTM. manufactured by L.B. Plastics of N.C., and similar prior art tend to channel water past perforations rather than down through them and into an underlying rain gutter. Prior art sought to correct this undesirable property by either tapering the rim of the open perforation and/or creating downward extensions of the perforation (creating a water channeling path down through open air space) as exhibited in prior art U.S. Pat. No. 6,151,837 to Ealer, or by creating dams on the plane the perforations exist on, as exhibited in prior art U.S. Pat. No. 4,727,689 to Bosler. Such prior art has been unable to ensure all water would channel into the underlying rain gutter because the water, that did indeed, travel through the open apertures on the top surfaces of these types of perforated planes or screens, would also travel along the underside of the screen wires or perforated planes, as it had on top of these surfaces, and still continue it's undesirable flow to the front of the invention and front lip of the underlying rain gutter, due to water adhesion. Additionally, this “underflow” of water on the underside of the perforated planes and screens illustrated in prior art exhibits a tendency to “backflow” or attempt to flow upwards through the perforations inhibiting downward flow of water. This phenomenon has been noted in practice, in the field when it has been observed that open air apertures appear filled with water while accomplishing no downward flow of water into the underlying rain gutter.
[0081] Other inventors sought to eliminate this undesirable property by employing linear rods with complete open air space existing between each rod, this method of channeling more of the water into the rain gutter exhibits greater success on the top surface of such inventions, but it fails to eliminate the “under channeling” of rainwater toward the front of the invention due to the propensity of water to follow the unbroken interconnected supporting rods or structure beneath the top layer of rods.”
[0082] I was able to accomplish significant improvement over prior art by employing a filter skeleton, illustrated in FIG. 3 of my U.S. Pat. No. 6,598,352, which incorporates ellipsed top members resting on upward extending planes adjoined to an underlying perforated planes. The upward extending planes of this filter skeleton contact the underside of a micromesh cloth composed of threads that are separated by no more than 120 microns of open airspace between threads and, at the point of plane and cloth contact, water has been noted to cease forward flow and redirect into significant downward flow of water into an underlying rain gutter. FIG. 8 of my U.S. Pat. No. 6,598,352 illustrates the filter skeleton and adjoined fine filtration cloth join and form separate member from the main body of the invention that is inserted into the main body of the invention. This unique configuration of fine filtration cloth and filter skeleton inserted into a recessed perforated well has been observed in practice, in the field over a two year period, to completely disallow the clogging of a rain gutter and to allow known clogging or moss overgrowth of the fine filtration cloth and skeleton combination in fewer than 10 product installations out of thousands of known installations. My U.S. Pat. No. 6,598,352 has been marketed the past two years as “Leaffilter RTM”.
Sub-Heading 1a
Upward Raised Planes and Perforations
[0083] During this period of practice in the field several improvements were made to U.S. Pat. No. 6,598,352 to ease its installation and lower its cost of manufacture and shipping. Most notably, in June of 2003 I redesigned the main body of my prior art found in U.S. Pat. No. 6,598,352 to incorporate the upward extending planes found in it's insertable filter skeleton directly into the perforated recessed well of the main body. This has been accomplished in both an extruded polymer main body and in a roll formed aluminum body of the present invention: This significantly improves ease of installation in that the present embodiment of “Leaffilter RTM” no longer employs an insertable polymer filter skeleton that was extruded in 50 foot lengths rolled into rolls approximately two feet in diameter and weighing approximately 9 lbs. These were discovered to be difficult to install due to the size and weight of the insertable filtration member and noted to significantly stiffen as field temperatures cool below approximately 40 degrees. Additionally, the insertable polymer filter skeleton illustrated in FIG. 6 of my U.S. Pat. No. 6,598,352 required transportation to a sewing converter which accomplished unrolling and re-rolling of the polymer filtration skeleton as polymer filtration cloth was sewn to the base of the skeleton. This action required additional shipping costs as well.
[0084] Referring to FIG. 3 , there is illustrated a multi level supporting skeleton comprised of perforated plane 17 (existing beneath plane 11 ), non perforated planes 18 , 20 , 21 , and, referring to FIG. 4 , comprised of perforated planes 25 , 32 , 39 , 49 , 52 , 60 , and comprised of non perforated planes 46 and 57 , and comprised of upward extending “bumps” 29 , 36 , 43 , 48 , 51 , 54 , 59 , and comprised of non perforated planes 39 and 49 which are adjoined by downward extending channels 38 and 48 collectively. This multi level support skeleton is referred to, collectively, as 23 ev . Incorporating the upward extending planes and perforated wells found in the flexible insertable filter skeleton of my prior art into the main body of the present invention, in the above described manner, achieves the same water directing properties by means of water adhesion and water pressure (due to water volume existent in said wells) found in my prior art and does so utilizing less material resulting in a lower cost of manufacture while additionally eliminating a separate insertable member subject to stiffening during cold weather installations.
Sub-Heading 1b
Filtration Membrane
[0085] It was also discovered during this period of practice (installing the Leaffilter RTM gutter cover in the field over a period of two years) that the warp-knit polymer fabric employed as a filtration membrane sewn to an underlying insertable filtration skeleton, illustrated in FIGS. 5 and 6 of my U.S. Pat. No. 6,598,352, succumbed to UV exposure deterioration over a period of time regardless of the amount of UV inhibitors employed. This may have been due to the small denier of polymer threads that constituted the polymer fabric. Significant improvement is accomplished in the present invention in substituting a woven stainless steel micro mesh cloth as is illustrated in FIG. 6 of the present invention. In the prior art of U.S. Pat. No. 6,598,352 it is disclosed that threads that adjoin or intersect one another are less subject to debris lodging between threads and tend to present less resistance to downward water flow than does woven or knitted micromesh cloths: both intersecting threads of dissimilar deniers and adjoining threads of similar deniers have been noted to exhibit desirable debris repellant and water permeability features to a greater degree than is found in typical woven or knitted micromesh fabric. However, there is presently no known technology able to mass produce warp-knit cloth utilizing metallic threads. It has been noted in field installations of the present invention, accomplished over a period of approximately one year, that woven stainless steel threads exhibit water permeability that approaches that found in the polymer warp-knit micro mesh fabric utilized in my prior art, provided that the wire diameter of the woven stainless steel threads does not exceed 10 mm, the thread count does not exceed 100×100, and the wires are crimped or pressed at their point of weave or contact so that the combined height of two threads is lessened at the point that one thread weaves over or under another. In testing, it has been further discovered that the same debris shedding properties are present in configurations of wire cloth that employ “crimped weaves” whereby pressure is applied at the point of weave contact between threads. This crimping of metallic threads at their point of contact places threads in more of a linear plane in relation to one another which allows the cloth to shed rather than trap debris. As disclosed in U.S. Pat. No. 6,598,352, the greater the vertical height between threads at their point of contact, the more likely it is that debris will be trapped and held rather than shed.
[0086] The present invention utilizes woven wire cloth exclusively as it has been discovered that such cloth, even as a woven cloth, exhibits less shifting of threads and less height differential between threads as well as providing a filtering membrane less susceptible to decay in comparison to polymer or natural “warp-knit” fabrics. FIGS. 5 and 5 a , of the present invention illustrate a stainless steel wire cloth 71 of not less than 100×100 thread count, crimp woven.
[0087] Referring now to FIG. 6 , the illustrated micro mesh stainless steel wire cloth serves as an insertable filtration membrane 71 not subject to stiffening as field temperatures cool and has been noted, in the field, to be more easily handled in any temperature as it is much lighter and far less bulky than the filtration skeleton covered with attached polymer micromesh cloth that served as the insertable filtration member found in my prior art illustrated in FIGS. 5 and 6 of my U.S. Pat. No. 6,598,352.
[0088] FIG. 5 : 71 of the present invention illustrates that the lateral edges 71 a of the stainless steel filtration membrane are hemmed. This is presently accomplished by passing 120 foot lengths of stainless steel cloth, slit to 4 inches width, though a roll former that hems the lateral edges of the stainless steel cloth and re-rolls its entire length into an easily handled roll approximately 4 inches in diameter and weighing less than 1.5 lbs. The manufacture and packaging of the stainless steel filtration member eliminates a shipping step necessary in manufacturing and packaging the polymer filtration skeleton used in my prior art and allows the filtration member of the present invention to be packaged in the same box that holds 5 foot lengths of the main body: the polymer filtration skeleton disclosed in my prior art formerly utilized in the Leaffilter RTM product was boxed separately from the main body of disclosed in my prior art and utilized in the Leaffilter RTM product. Hemming the stainless steel filtration membrane 5 : 71 of the present invention provides a dull edge unlikely to cause cuts as filtration member is handled in the field prior to and during installation.
Sub-Heading 1b
Installation of Filtration Member
[0089] Once installation of the main body 69 is installed into the top open area of a k-style rain gutter 72 as illustrated in FIG. 7 . Referring now to FIG. 6 ; installation of the stainless steel filtration member is accomplished by grasping the leading edge of a roll of the filtration member and pulling it through channels 22 and 65 of the main body 69 of the present invention. Referring again to FIG. 7 ; once this final step of installation is accomplished, rain water will flow off roof member 74 through stainless steel micro mesh filtration member 71 contacting upraised “bumps”, such as 48 and 51 , and being diverted downward by these planes down through perforations 70 into an underlying rain gutter 72 . The present invention thereby provides a more economical and more readily installed gutter protection method than Leaffilter RTM. offers while proving equally capable of preventing debris as small as 100 microns from entering a rain gutter while ensuring nearly 100% of rain water run off from roof members enters underlying gutters as has been noted in the field.
Sub-Heading 2
Material and Manufacturing Process
[0090] It is important to note that the dimensions listed in the Description of the Preferred Embodiment of this present invention are descriptive of the present invention as it currently has been manufactured for 11 months in a polymer embodiment that is different in several respects (disclosed in this application) from its original manufactured embodiment that closely resembled the preferred embodiment illustrated in my U.S. Pat. No. 6,598,352. Additionally, a roll-formed metallic prototype of the present invention employing smaller thinner “bumps” and shallower perforated “wells” has demonstrated that the operation of the present invention; specifically its ability to break the forward flow of water that occurs over flat perforated planes and direct it downward, varies little providing that the height of “bumps” does not fall below 0.06 inch. and provided the dimensions of perforations 70 have a minimum length of 0.25 inch and a minimum width of 0.15 inch and are spaced longitudinally at a distance no greater than 0.18 inch. Smaller perforations spaced further apart proved insufficient at draining large amounts of water into an underlying rain gutter.
[0091] In summary, a critical element described in claim one of technology described in my U.S. Pat. No. 6,598,352 (under which the Leaffilter RTM is manufactured) is the utilization of upraised planes rising from and forming the sides of perforated wells. These underlying planes contact the underside of a filtration cloth and break the forward flow of water and direct it downward into an underlying rain gutter. This technology of “upraised planes” breaking the forward flow of water and directing it downward, described in my U.S. Pat. No. 6,598,352, has been demonstrated to remain effective through subsequent alternate embodiments described in this present invention that have unified separate elements and varied the height and the width and positioning of the upraised planes resulting in a more easily installed and economically manufactured product. The process of roll-forming metal disallows exact duplication of shapes and dimensions possible in extrusion of polymers. Extensive testing and redesign of an alternate metallic roll formed embodiment of the Leaffilter RTM product has disclosed that some further alterations of the dimension and position of water directing planes disclosed as the Preferred Embodiment of this present invention can be accomplished. resulting in a more easily installed and economically manufactured product.
Description of Alternate Embodiments
[0092] Referring to FIG. 8 there is illustrated an alternate embodiment of the present invention: 44 tc which is a triangular shaped channel that will receive a triangular shaped joining member FIG. 9 : 76 . Sides 44 × and 44 z have approximate lengths of 0.23 inch. and side 44 y has an approximate length of 0.28 inch. Triangular shaped joining member 76 has equilateral sides with approximate lengths 76 a , 76 b , 76 b , of 0.21 inch.
[0093] It has been noted in the field that after installation of the present invention into a rain gutter, a variance in height between adjoining main bodies 69 of the present invention may occur. This alternate embodiment serves to lock main bodies 69 into the same horizontal plane preventing any debris entrance into a rain gutter occurring through open air spaces that may occur if adjoining main bodies 69 rise or fall above or beneath one another. FIG. 11 further illustrates that joining member 76 inserts partially into the triangular shaped channel of a main body 69 a allowing an adjoining main body 69 b to be slid into place allowing its triangular shaped channel to encompass a remaining portion of joining member 76 .
[0094] Referring again to FIG. 8 : 77 tc , it is illustrated that a triangular channel may also be employed at the front most portion of the main body 69 of the present invention to serve as a means of receiving joining members.
Operation of an Alternate Embodiment
Flow Screen
[0095] Referring to FIG. 8 : 44 ×, 44 y , 44 z , there is illustrated a downward extending triangular shaped channel 44 tc . This alteration of the downward extending channel illustrated in FIG. 2 : 44 allows for the insertion of an extruded polymer or roll formed metallic triangular shaped joining member FIG. 9 : 76 to be inserted into two adjoining main bodies 69 a and 69 b of the present invention, as illustrated in FIG. 11 , allowing the main bodies to abutted against each other and held at a consistent level prohibiting one main body from rising above or falling beneath the profile of previous or subsequent main body members it may be abutted against.
REFERENCE NUMERALS IN DRAWING
[0000]
1 . plane 1 , length: approximately 0.11 inch
2 . circumference 2 , outside diameter approximately 0.06 inch
3 . plane 3 , length approximately 0.53 inch.
4 . angle 4 , approximately 60 degrees.
5 . plane 5 , length approximately 0.5 inch.
6 . plane 6 , length approximately 0.35 inch
7 . circumference 7 , when the present invention is in a metallic roll formed state, outside diameter approximately 0.06 inch termination point 7 , when the present invention is in a polymer extruded state
8 . plane 8 , length approximately 0.42 inch
9 . channel 9 , when the present invention is in a metallic roll formed state, with an open air space of approximately 0.022 inch
10 . angle 10 , approximately 60 degrees
11 . plane 11 , length approximately 0.44 inch
12 . circumference 12 , when the present invention is in a metallic roll formed state, outside diameter approximately 0.06 inch termination point 12 , when the present invention is in a polymer state
13 . Plane 13 , has an approximate length of 0.44 inch
14 . circumference 14 , has an approximate outside diameter of 0.075 inch
15 . plane 15 , length approximately 0.17 inch
16 . plane 16 , length approximately 0.045 inch
17 . plane 17 , length approximately 0.157 inch
18 . plane 18 , length approximately 0.045 inch
19 . perforated well
20 . plane 20 , length approximately 0.10 inch
21 . plane 21 , length approximately 0.045 inch
22 . receiving channel 22
22 w . width: 0.48 inch of channel 22
22 h . height: 0.056 inch of channel 22
23 . plane 23 , length of approximately 0.154 inch
23 ev . multi-level water receiving area of the present invention
24 . plane 24 , length of approximately 0.045 inch
24 e . partial ellipse, with a partial circumference of approximately 0.03 inch
25 . perforated well
25 w interior width: of perforated well 25 : 0.15 inch measured from plane 21 to plane
25 h . interior height: 0.06 of perforated well 25
26 . plane 26 , length approximately 0.070 inch measured from partial ellipse 24 e to partial ellipse 27 e
27 . plane 27 , length approximately 0.045 inch
28 . ellipsed cap 28 , length approximately 0.16 inch
29 . bump, a supportive and water directing plane
29 w . interior width: 0.13 inch of bump 29 measured from plane 24 to plane 27
29 h . height: 0.068 inch of bump 29
30 . plane 30 , length approximately 0.154 inch
31 . plane 31 , length approximately 0.045 inch
31 e partial ellipse, with a partial circumference of approximately 0.03 inch
32 . perforated well
32 w . interior width: of perforated well 32 : 0.15 inch measured from plane 27 to plane 31
32 h . interior height: 0.06 inch of perforated well 32
33 . plane 33 , length approximately 0.070 measured from partial ellipse 31 e to partial ellipse 34 e
34 . plane 34 , length approximately 0.045 inch
34 e . partial ellipse, with a partial circumference of approximately 0.03 inch
35 . ellipsed cap 35 , length approximately 0.16 inch
36 . bump, a supportive and water directing plane
36 h height: 0.068 inch of bump 36
37 . plane 37 , length approximately 0.154 inch
38 . plane 38 , length approximately 0.045 inch
39 . perforated well
39 h . interior height: 0.06 inch of perforated well 39
39 w . interior width: of perforated well 39 : 0.15 inch measured from plane 34 to plane 38
40 . plane 40 , length approximately 0.070 measured from partial ellipse 38 e to partial ellipse 41 e
41 . plane 41 , length approximately 0.28 inch
41 c . circumference 41 c , approximate outside diameter 0.06 inch
41 d . plane 41 d , length approximately 0.23 inch
42 . ellipsed cap 42 , length approximately 0.16 inch
43 . bump, a supportive and water directing plane
43 h . height: 0.33 inch of channel 44
44 . channel 44
44 w width: 0.03 inch of channel 44
44 tc . alternate triangular shaped embodiment of channel 44
44 x . side 44 x approximate length 0.23 inch
44 y . side 44 y approximate length 0.28 inch
44 z . side 44 z approximate length 0.23 inch
45 . plane 45 , length approximately 0.13 inch
46 . non-perforated well
46 h . interior height: 0.06 inch of non-perforated well 46
46 w . interior width: of on-perforated well 46 : 0.15 inch measured from plane 41 to bump 48
47 . ellipsed cap 47 , length approximately 0.16 inch
48 . bump, a supportive and water directing plane
49 . perforated well
50 . ellipsed cap 50 , length approximately 0.16 inch
51 . bump, a supportive and water directing plane
52 . perforated well
53 . ellipsed cap 53 , length approximately 0.16 inch
54 . bump, a supportive and water directing plane
55 . plane 55 , length approximately 0.28 inch
55 c . circumference 55 , approximate outside diameter 0.06 inch
55 d . plane 55 d , length approximately 0.23 inch
56 . channel 56
57 . non-perforated well
58 . ellipsed cap 58 , length approximately 0.16 inch
59 . bump, a supportive and water directing plane
60 . perforated well
61 . plane 61 , length approximately 0.045 inch
62 . plane 62 , length approximately 0.44 inch
63 . circumference 63 , approximate outside diameter 0.06 inch
64 . plane 64 , length approximately 0.4 inch
65 . channel 65
66 . plane 66 , length approximately 1.5 inch
67 . circumference 63 , approximate outside diameter 0.06 inch
68 . plane 68 , length approximately 1.5 inch
69 . main body
70 . perforations
71 . metallic cloth filtration membrane
72 . k-style rain gutter
73 . top lip of k-style rain gutter
74 . roof membrane
75 . sub roof
76 . joining member
76 a . side 76 a approximate length 0.21 inch
76 b . side 76 b approximate length 0.21 inch
76 c . side 76 c approximate length 0.21 inch
M 1 ( 3 ). main plane 1 , only illustrated as such in FIG. 1 for the purpose of illustrating one of five major interconnecting planes of the present invention, illustrated as plane 3 otherwise
M 2 ( 5 ). main plane 2 , only illustrated as such in FIG. 1 for the purpose of illustrating one of five major interconnecting planes of the present invention, illustrated as plane 5 otherwise
M 3 ( 11 ). main plane 3 , only illustrated as such in FIG. 1 for the purpose of illustrating one of five major interconnecting planes of the present invention, illustrated as plane 11 otherwise M 4 ( 23 ev ). main plane 4 , only illustrated as such in FIG. 1 for the purpose of illustrating one of five major interconnecting planes of the present invention, illustrated as plane 23 ev other wise. M 5 ( 66 ). main plane 5 , only illustrated as such in FIG. 1 for the purpose of illustrating one of five major interconnecting planes of the present invention, illustrated as plane 66 otherwise. | An elongated strip of extruded plastic or roll formed metal material includes a rear securing fifth plane that inserts beneath a roofing membrane of a building structure. The rear plane integrally connects to a forward extending perforated fourth plane by means of a u shaped channel, one of two u shaped channels, which additionally serve to receive and secure a lateral edge of a filtration membrane. The perforated fourth plane contains intrinsic and intersecting vertical water directing planes that extend above and beneath the surface of the fourth plane and which serve to support and contact an overlying insertable filtration membrane. The fourth plane connects to a forward extending third plane by means of a u shaped channel that serves to receive and secure a lateral edge of a filtration membrane. The third plane connects to a second plane by means of a downward extending u shaped channel. The second plane rests on the top front lip of a k-style gutter and is adjoined by a downward angled first plane that serves to disallow roof water runoff from contacting the front face of a k-style gutter. A combination of a filtration membrane configured for water permeability and debris repellency resting on vertical planes serves to break the forward flow of water, at points of contact between the vertical planes and filtration membrane, and also serves to further channel water downward through an underlying perforated plane into an underlying rain gutter. The filtration membrane is readily inserted into the u-shaped channels existing on the forward and rear edges of a perforated fourth plane. | 4 |
[0001] This application claims the benefit of the Korean Patent Application No. 2005-50258 filed in Korea on Jun. 13, 2005, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a sputtering apparatus, and more particularly, to a sputtering apparatus and a method of driving the sputtering apparatus that are capable of achieving an optimum deposition.
[0004] 2. Background of the Related Art
[0005] In general, a sputtering apparatus typically deposits a target material on a substrate by colliding ions accelerated in plasma with a target. As compared to a chemical vapor deposition (CVD) apparatus that performs processes at a high temperature, the sputtering apparatus is advantageous in performing a sputtering process where a thin film can be formed while a substrate is maintained at a low temperature of about 400° C. Such a sputtering apparatus has been widely utilized for a flat panel display device such as a liquid crystal display (LCD) device, an organic electroluminescence device, or the like because of its simple structure and formation of a deposition layer in a short period of time.
[0006] The conventional sputtering apparatus has a cathode connected to a target, which is provided in a chamber, and an anode connected to a substrate. When a predetermined voltage is applied between the cathode and the anode, electrons are bombarded with an inert gas and are thus ionized. When the ionized positive ions are accelerated toward the cathode target and collide with the target, a target material is sputtered from the target, thereby depositing the target material on the substrate to form a predetermined layer. The electrons are excited by bombarding neutral atoms to thereby generate plasma. The plasma is maintained when an external potential is maintained and electrons are continuously generated.
[0007] The sputtering apparatus may be classified into a cluster type and an in-line type. FIG. 1 is a schematic cross-sectional view illustrating a cluster type-sputtering apparatus according to the related art. As shown in FIG. 1 , the related art cluster type sputtering apparatus includes a chamber 100 that serves to accommodate a substrate 110 transferred from the outside, a lifter 120 that is able to be placed upright to support the substrate 110 , a target 130 including a target material to be deposited onto the substrate 110 , and a mask 140 arranged in front of the target 130 . Specifically, the substrate 110 is transferred horizontally into the chamber 100 and mounted on the lifter 120 . Then, the lifter 120 carrying the substrate 110 is lifted upright in the chamber 100 , and a sputtering process is thus performed. This sputtering apparatus is advantageous in that the degree to which the vacuum and temperature change is minimized because the lifter 120 constantly maintains the vacuum and certain temperature. Also, a gap of about 5 mm between the mask 140 and the substrate 110 within the chamber 100 can be maintained, thereby minimizing the deposition of the target material from the target 130 onto the lifter 120 supporting the substrate 110 . However, such a cluster type sputtering apparatus cannot perform a deposition process for a large-sized substrate, which is greater than 2 m×2 m, due to the weight of equipment and an increase in pump capacity.
[0008] Recently, an in-line type sputtering apparatus has been increasingly utilized to perform the deposition process for large-sized substrates. FIG. 2A is a plan view schematically illustrating an in-line type sputtering apparatus according to the related art. FIG. 2B is a cross-sectional view schematically illustrating the in-line type sputtering apparatus within a chamber. As shown in FIGS. 2A and 2B , the related art in-line sputtering apparatus has a carrier 220 to transfer a substrate 210 into a chamber 200 . Then, unlike the aforementioned cluster type lifter 120 , the carrier 220 is not placed upright within the chamber 200 , but is moved in a direction perpendicular to a mask 240 of the chamber 200 to transfer the substrate 210 to a region facing a target 230 , thereby depositing a target material from the target 230 onto the substrate 210 .
[0009] However, even though the related art in-line type sputtering apparatus is suitable for the deposition process on a large-sized substrate, it is difficult to adjust a gap between the substrate 210 and the mask 240 to be smaller than 10 mm, because the carrier 220 is moved vertically to transfer the substrate 210 to a region facing the target material 230 . In other words, when the substrate 210 and the carrier 220 are moved vertically, they may be bent due to thermal deformation or the like, thereby causing a variation of an error range in uniformity of the substrate 210 and the carrier 220 . If the carrier 220 and the substrate 210 are transferred to the region facing the target material 230 regardless of such a variation, the substrate 210 and the mask 240 may have a gap greater than 10 mm in one region and smaller than 10 mm in another region, and may even contact each other. In the event that the substrate 210 and the mask 240 contact each other, the substrate 210 may be scratched by the mask 240 and thus contaminated, or the substrate 210 may be damaged by a collision with the mask 240 . Moreover, in the related art in-line sputtering apparatus, since the substrate 210 and the mask 240 have the gap as wide as approximately 10 mm, particles generated by a back sputtering contaminate the carrier 220 .
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention is directed to a sputtering apparatus and a method of driving the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.
[0011] An object of the present invention is to provide a sputtering apparatus and a driving method thereof capable of preventing particle contamination caused due to a contact between a mask and a carrier by maintaining a uniform gap therebetween regardless of deformation of a substrate.
[0012] Another object of the present invention is to provide a sputtering apparatus and a driving method thereof capable of preventing particle contamination caused due to back sputtering by minimizing a gap between a mask and a carrier.
[0013] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0014] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a sputtering apparatus for depositing a target material on a substrate, which includes a chamber, a target including the target material in the chamber, a carrier to carry substrate into the chamber to face the target, and a plurality of masks arranged along sides of the carrier in the chamber and being movable back and forth with respect to the carrier.
[0015] In another aspect of the present invention, there is provided a method of driving a sputtering apparatus including a target for a target material, a carrier to carry a substrate to face the target in a chamber, and a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier. The method includes transferring the carrier and the substrate in the chamber to face the target, moving the carrier and the substrate toward the target, moving each of the plurality of masks toward the carrier, and performing a sputtering process, thereby depositing the target material from the target onto the substrate.
[0016] In a further another aspect of the present invention, there is provided a sputtering apparatus for depositing a target material on a substrate, which includes a carrier to carry the substrate, a first chamber to measure a bending degree to which the carrier bends, and a second chamber including a target for the target material, a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier, and a plurality of moving units to move the plurality of masks, wherein the plurality of masks are each movable individually depending on the bending degree of the carrier.
[0017] In a still further another aspect of the present invention, there is provided a method of driving a sputtering apparatus including a first chamber to measure a degree to which a carrier carrying a substrate bends, and a second chamber including a target for a target material, a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier, and a plurality of moving units to move the plurality of masks, respectively. The method includes measuring the bending degree to which the carrier bends when the carrier and the substrate are transferred in the first chamber, transferring the carrier carrying the substrate from the first chamber to the second chamber, wherein the carrier is moved to face the target, moving the carrier toward the target, and moving each of the plurality of masks toward the carrier depending on the bending degree of the carrier.
[0018] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0020] FIG. 1 is a schematic cross-sectional view illustrating a cluster type sputtering apparatus according to the related art;
[0021] FIG. 2A is a plan view schematically illustrating an in-line type sputtering apparatus according to the related art;
[0022] FIG. 2B is a cross-sectional view schematically illustrating the related art in-line type sputtering apparatus within a chamber;
[0023] FIG. 3A is a plan view schematically illustrating an in-line type sputtering apparatus according to an exemplary embodiment of the present invention;
[0024] FIG. 3B is a cross-sectional view schematically illustrating an in-line type sputtering apparatus within a chamber according to the exemplary embodiment of the present invention;
[0025] FIG. 4 is a view schematically illustrating an exemplary arrangement of floating masks of FIGS. 3A and 3B ; and
[0026] FIG. 5 is a plan view schematically illustrating an in-line type sputtering apparatus according to another exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0028] FIG. 3A is a plan view schematically illustrating an in-line type sputtering apparatus according to an exemplary embodiment of the present invention, and FIG. 3B is a cross-sectional view schematically illustrating the in-line type sputtering apparatus of FIG. 3B . As shown in FIG. 3A , the in-line type sputtering apparatus of the exemplary embodiment has a carrier 320 to transfer a substrate 310 into a process chamber 300 . Then, unlike the aforementioned cluster type lifter 120 , the carrier 320 is not placed upright within the process chamber 300 , but is moved in a direction perpendicular to a mask part MP of the chamber 300 to transfer the substrate 310 to a region facing a target 330 , thereby depositing a target material from the target 330 onto the substrate 310 .
[0029] According to this exemplary embodiment, the mask part MP includes a mask 342 , a plurality of floating masks 344 and a plurality of floating mask moving units 346 . After the completion of the vertical transfer of the carrier 320 in the process chamber 300 , the floating masks 344 may be moved toward the carrier 320 , thereby reducing a gap between the floating masks 344 and the carrier 320 as compared to the related art in-line type of FIGS. 2A and 2B . Moreover, FIG. 4 schematically illustrates an exemplary arrangement of the plurality of floating masks 344 of FIG. 3 . As shown in FIG. 4 , the floating masks 344 may further include first, second, third and fourth floating masks 344 a , 344 b , 344 c and 344 d . In this exemplary embodiment, the four floating masks 344 a to 344 d are provided on four separated sides of the mask 342 , respectively. Alternatively, fewer or more floating masks may be used.
[0030] Referring to FIG. 3B , the process chamber 300 of the exemplary sputtering apparatus includes a substrate part SP, a target part TP, and the mask part MP. As shown in FIG. 3B , the target part TP includes a rear plate 314 , the target 330 attached to the rear plate 314 , and a magnet 318 provided behind the rear plate 314 . The magnet 318 supplies a magnetic field to prevent electrons generated in the plasma from undesirably coming out of a plasma generation region. The rear plate 314 serves to fix the target 330 that includes a target material to be deposited onto the substrate 310 by a sputtering process. Moreover, a cathode (not shown) may be provided between the target 330 and the rear plate 314 . The rear plate 314 may also serve as the cathode.
[0031] The substrate part SP includes the substrate 310 onto which the target material from the target 330 is to be deposited by the sputtering process, and the carrier 320 carrying the substrate 310 . An anode (not shown) may be provided between the substrate 310 and the carrier 320 . The carrier 320 may also serve as the anode.
[0032] As discussed above, the mask part MP includes the mask 342 , the floating masks 344 (e.g., 344 a to 344 d ), and the floating mask moving units 346 . The mask 342 is fixedly connected to the chamber 300 . The floating masks 344 a to 344 d are arranged corresponding to the four sides of the masks 342 , respectively, and are movable back and forth (i.e., backward and forward). The floating masks 344 are moved by the floating mask moving unit 346 . In this exemplary embodiment, as shown in FIG. 3B , the forward direction is toward the carrier 320 , and the backward direction is away form the carrier 320 .
[0033] When the process of transferring the carrier 320 and the substrate 310 is finished, the carrier 320 is moved toward the target 330 . In this exemplary embodiment, the substrate 310 and the mask part MP have a gap of approximately 10 mm therebetween. A separate moving unit may be provided to move the carrier 320 toward the target 330 . Moreover, the floating mask moving units 346 may include first to fourth moving units, which correspond to the first to fourth floating masks 344 a to 344 d of FIG. 4 , respectively. Moreover, the floating masks 344 a to 344 d may be individually driven or may be driven all together at the same time by the corresponding first to fourth moving units, respectively. According to such an arrangement of the exemplary embodiment, when the substrate 310 and the carrier 320 are bent due to thermal deformation, the floating masks 344 a , 344 b , 344 c and 344 d are separately adjusted to have the same gaps with the substrate 310 despite of the uniformity variations due to the bending of the substrate 310 .
[0034] The carrier 320 transferred and fixed to a region facing the target 330 is moved toward the target 330 , and the floating masks 344 are moved toward the carrier 320 by the floating mask moving unit 346 , thereby reducing a gap between the floating masks 344 and the carrier 320 as compared to the related art. For example, the gap between the floating masks 344 and the substrate 310 according to the exemplary embodiment is approximately 5 mm, whereas the gap between the mask and the substrate according to the related art is approximately 10 mm.
[0035] In the exemplary embodiment of the present invention, the gap between the floating masks 344 and the substrate 310 is reduced in the aforementioned manner, thereby preventing particle contamination due to the back sputtering. Also, a certain amount of gap therebetween is maintained, thereby avoiding the occurrence of particle contamination due to a contact between the floating masks 344 and the substrate 310 . Moreover, in the exemplary embodiment, a stable plasma generation system may be implemented in an in-line sputter by minimizing undesirable vibrations of the carrier 320 at the time of transfer thereof.
[0036] The floating mask moving units 346 may be driven by a motor or the like, thereby moving the respective floating masks 344 . Also, the floating mask moving units 346 may be controlled individually or together by a control unit (not shown) provided in the mask part MP. Moreover, the mask 342 may be formed in a quadrangular frame shape of a conductive material such as aluminum (Al) or the like, and generates plasma by maintaining the potential difference with the target 330 serving as a cathode. The floating masks 344 may be formed of a conductive material such as aluminum (Al) and may be electrically insulated from the mask 342 .
[0037] When the sputtering process is finished and the target material from the target 330 is deposited on the substrate 310 in a state where the floating masks 344 have been moved toward the substrate 310 , the floating masks 344 move back to their initial positions so that the floating masks 344 and the substrate 310 are spaced apart again by approximately 10 mm. Moreover, individual carriers may have different bending degrees depending on assembly differences, vacuum, thermal impact, or the like.
[0038] FIG. 5 is a plan view schematically illustrating an in-line type sputtering apparatus according to another exemplary embodiment of the present invention. As shown in FIG. 5 , unlike the embodiment of FIG. 3A , the in-line type sputtering apparatus according to this exemplary embodiment further includes a load chamber 400 in front of the process chamber 300 in which the sputtering is performed.
[0039] The load chamber 400 is provided with a carrier-bending measuring unit (not shown) that measures the degree to which a carrier 320 transferring a substrate 310 bends before the sputtering. That is, since a plurality of carriers 320 have different properties including different bending degrees, the bending degree of each carrier 320 is measured before the sputtering process. Accordingly, when the floating masks 344 a to 344 d are moved toward the carrier 320 , the degrees to which the floating masks 344 a to 344 d provided on the four sides of the mask 342 move are individually controlled. Herein, each carrier 320 may be identified by, for example, a bar code provided to the carrier 320 .
[0040] After the bending degree of the carrier 320 is measured in the load chamber 400 and the carrier 320 is transferred into the process chamber 300 , the remaining processes are the same as those illustrated in FIG. 3B , and therefore, the detailed description thereon is omitted.
[0041] According to the exemplary embodiment of FIG. 5 , when the floating masks 344 a to 344 d are moved toward the carrier 320 , the floating masks 344 a to 344 d may be moved to different degrees in consideration of the bending degree of the carrier 320 . That is, the floating-mask moving units 346 within the process chamber 300 are provided to correspond to the respective floating masks 344 a to 344 d , and are separately moved by a control unit provided in the mask part MP depending on the measured bending degree of the carrier 320 .
[0042] As described so far, according to the exemplary embodiments of the present invention, a gap between a mask and a carrier within an in-line sputtering apparatus can be reduced, thereby preventing a target material from being unnecessarily deposited on the carrier and also avoiding contamination of the chamber and vibrations of transferring the carrier. Accordingly, a stable plasma generation system can be achieved in the in-line sputtering apparatus of the present invention.
[0043] It will be apparent to those skilled in the art that various modifications and variations can be made in the sputtering apparatus and the method of driving the sputtering apparatus of the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A sputtering apparatus for depositing a target material on a substrate includes a chamber, a target in the chamber to provide the target material, a carrier to carry the substrate in the chamber to face the target, and a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier. | 2 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of Ser. No. 350,141 filed 2/19/82, now abandoned.
Numerous low-temperature gradient heat sources have not been harvested for power production because the conversion efficiency is prohibitively low. Recently, with power costs soaring, the feasibility of power from these sources is being reexamined, with special attention directed to conversion of energy from naturally heated water.
Such ideas are not new since as early as 1881 d'Arsonral proposed an Ocean Thermal energy conversion (OTEC); and in 1930 Georges Claude demonstrated the idea in ocean waters using deep sea water for his cold source and surface water for his heat source in an open Rankine cycle process. Since then many others have made studies of OTEC designs, generally concluding that closed Rankine cycle plants would be more feasible with existing technology. In theses studies, ammonia was generally one of the favored choices for a working fluid, if not the top choice. Dugger, G. L., E. J. Frances and W. H. Avery; 1976. Technical and Economic Feasibility of Ocean Thermal Energy Conversion, Sharing the Sun: Solar Technology in the Seventies, Vol. 5 Solar Thermal and Ocean Thermal. Library of Congress, April 1978, Energy from the Ocean, U.S. Govt. Printing Office.
The attractiveness of ponds, lakes, sea or ocean waters as heat sources for the energy conversion resides in several factors:
1. Zero fuel costs.
2. The thermal gradients are a product of solar or earth heat energy, continuously renewable.
3. A TEC operation using solar heated bodies of water, unique among all solar technologies, will not be interrupted when the sun does not shine.
4. The amount of energy is vast.
5. In warmer areas, the temperatures remain fairly constant, with only minor seasonal and diurnal variations; consequently, large storage capacity is unnecessary.
6. Production of wastes by TEC power plants is negligible compared to nuclear and fossil fuel plants. The problem of disposal of large amounts of heated water is greatly reduced.
7. A TEC facility could produce energy-intensive materials (such as aluminum and fertilizers), reducing demands on other fuel supplies.
8. In addition to producing electric power, a TEC facility could produce portable fuels, such as hydrogen and ammonia.
Most of the problems anticipated in such practical conversions are economic. All the technology necessary is understood, and the details for implementation have been extensively studied and continue to be investigated. Plant prototypes have been engineered; and a pilot OTEC installation was successfully operated to collect data in late 1979. Biofouling and corrosion of heat exchangers are major concerns, but not prohibitive; options for satisfactory handling are available and choices are primarily cost-related. Three serious limitations persist:
1. In an OTEC, the difference in temperature between the sun heated surface layer of oceans and the cold, deep layers is seldom substantially greater than 20° C., supporting only 3.3% thermal efficiency in conventional Rankine cycle systems. No other type plant promises as high feasibility. The consequences are formidable capital costs, with heat exchanger costs of one-third to one-half of the total.
2. Ocean waters with reliable temperature differences are not close enough to most major electric power demands for economic electricity transmission to them. Except for electric power transmissions to tropical coastal areas, OTEC power would need to be used at or near the production site e.g. in energy intensive manufacture or in production of chemicals to be shipped or piped to utilization sites for energy release or conversion.
3. The density of OTEC siting is limited. Even though the ocean resource is enormous, the environmental impact of large scale OTEC operation may be significant. It has been calculated that this should not be a formidable deterrent at this time and that the Gulf stream should be able to support OTEC output of nearly 200,000 MWe without deleterious effects on the environment of any magnitude, an output roughly equivalent to the total US electric utility sales to customers. These calculations were based on conservative estimates from available relevant data, including the critical assumption that a temperature reduction of 0.5° C. in the upper 10 meters of the Gulf Stream would be tolerated.
It is evident that a major determinant of the future of OTEC, if not the most important factor, is the low efficiency of thermal conversion due to the small temperature differences between warm and cold water layers. No method of countering this problem has yet been tested. It is well known that part of the heat from low temperature sources may be made available at higher temperatures if enough of the remaining heat is rejected at lower temperatures, avoiding challenge to the second law of thermodynamics. A number of devices have been known for some time which can accomplish this, including the Hilsch tube and vapor compression heat pumps, but their use is unsuitable for power production, since more power is needed to operate them than can be gained by the higher temperatures.
Somewhat similar to OTEC are other thermal conversion operations which harvest solar energy caught in smaller bodies of water and which use the same general methods for conversion of heat to mechanical or electrical energy: utilizing the heat from the warm water to vaporize a working fluid to a gas which drives a turbine in a typical Rankine cycle. Seas, lakes and ponds are all possibilities for such bodies of water; all could furnish substantial amounts of warm water from surface layers. As with ocean waters, the temperatures of the warm water would be low so TEC efficiency would be low; however, as well as enjoying the good OTEC features of non-pollution, no fuel requirement, and operation when the sun is not shining, these TECs would have some added advantages:
(1) They could be sited in areas that have no convenient access to OTEC;
(2) Smaller installations would be feasible when desired; and
(3) They could provide warmer water than ocean waters.
Currently, areas of the Dead Sea and many smaller pond areas are being used for TEC. In order to increase the temperature of the warm water and to increase and conserve the heat absorbed from solar radiation, certain devices are used. When a pond is constructed for TEC, a typical installation will have a salt solution 3 to 5 meters deep, residing over an impervious lining to prevent seepage loss. Solar energy penetrates to varying depths and warms the solution. In order to prevent the warmed solution from rising to the surface where it would lost energy to the atmosphere by evaporation, convection and radiation, the salt solution is maintained in layers of concentration increasing with depth, making a "salt gradient solar pond" (SGSP). Since the more concentrated solutions have greater density, even when heated, they maintain their levels and do not approach the surface. Such ponds commonly have 3 functional zones:
(1) A thin surface layer of fresh water to flush away dust and debris deposited from the atmosphere;
(2) Below that, a non-convective zone, which absorbs most of the solar energy; and
(3) Below that, a storage zone of heated salt solution. The heat is harvested in one of two ways: either by withdrawing solution from the storage zone, collecting heat from it through heat exchange, and returning the solution to the pond, or by installing heat exchangers in the storage zone.
Various methods are used to reduce heat loss from the top layers. These include criss-crossing long strips of screen over the pond surface to counteract wave motion which would stir up lower layers or layering a transparent gel above the collecting zone.
In operation, the temperature of the heated solution depends on rates of heat withdrawal and the solar energy available; in the contiguous United State 80° to 80° C. could be good working temperatures. Although substantially higher than ocean warm water temperatures, generally they would not support Rankine cycle efficiencies of over 12%.
This application describes a feasible process to increase thermal conversion efficiency of available heat in warm water by increasing the temperature of the heat input to a closed Rankine cycle system without excessive, parasitic power requirements, implementing one variation of the general process.
Accordingly, an object of the present invention is to provide a practical efficient warm water thermal energy conversion means and method.
BRIEF DESCRIPTION OF THE DRAWING
A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification wherein:
FIG. 1 is a schematic diagram of a system in accordance with the invention of a one-stage TIS.
FIG. 2 is a schematic diagram of a system in accordance with the invention using a two-stage TIS.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A temperature increase system (TIS) uses heat from warm water to decompose and separate ammonium hydroxide (NH 4 OH) into ammonia (NH 3 ) and water (H 2 O), then transfers these reactive substances to a heat exchanger in which they recombine releasing heat at a higher temperature. On the other side of the heat exchange surface, a working fluid is heated, vaporized and superheated by this heat; and the vapor drives a turbine in a typical closed Rankine cycle system (RCS) and is condensed with cold water.
An OTEC plant incorporating a single-stage TIS is diagrammed in FIG. 1, the TIS system on the left using flow lines 1 through 10, and the RCS system on the right using lines 11 through 17. In operation of the TIS, ammonia gas from fractionator F passes via line 1 into heat exchanger H collecting heat; thence via line 2 into reactor R2 where it meets a weak ammonia (mostly as ammonium hydroxide) solution from R1 via line 4. Most of the ammonia gas reacts with water in the solution to form more ammonium hydroxide with liberation of substantial amounts of heat at a higher temperature; the remaining ammonia gas proceeds via line 3 to R1 where it reacts completely with water from F (via line 7, pump P1, line 8, heat exchanger H, and line 9), liberating heat at a high temperature.
As the water proceeds from line 9 through R1 it progressively increases in ammonia content; through R2 it increases in ammonia content even more. Moving through H, it rejects heat to warm water and ammonia gas from F and liquid ammonia in the RCS. The partly cooled ammonia solution proceeds via line 6 to F, where the ammonia is fractionally distilled out with heat from warm sea water and reflux condensation from cold sea water; the resulting gaseous ammonia and liquid water are then recycled through the reactors as before. Hydrogen gas, with a reservoir in vessel V, is maintained in the system to equalize gas pressure throughout, thereby minimizing power expenditures for pumping.
The RCS (Rankine cycle system) is conventional, with most of the heat delivered from the TIS through heat exchange surfaces directly to the working fluid (WF). To reduce the amount of heat used from the TIS, the working fluid is first heated to as high a temperature as practical in preheater PH1 with heat from warm sea water. WF proceeds via line 15 to preheater PH2 where it is further heated by heat rejected from hot ammonia solution in H. WF then proceeds to evaporator E, where it is vaporized, to the demister D, and to superheater S, collecting heat in E and S from the ammonia-water reaction in R2 and R1. The superheated gas proceeds through line 11 to drive turbine T via line 12 to condenser C, cooled by cold sea water. The liquified WF is then pumped back into the cycle by feed pump P2 through line 14.
Only a single-stage TIS is shown, but multiple-stage units may be utilized: a low stage produces heat at a higher temperature, and this heat is the driving heat for the fractionator of the next stage. The number of stages to be used depends on economic tradeoffs rather than on physical and chemical constraints of the water-ammonia system, since other chemical reactions may be employed at temperatures above practical ranges for the water-ammonia system.
FIG. 2 diagrams a TIS-RCS system employing two sequential temperature increase stages. The first stage, incorporating sections P1, F1, R1 and V1, uses heat from warm sea water to separate ammonia gas from an ammonium hydroxide solution in fractionator F1; this gas then flows via line 1 to reactor R1. The solution in F1, depleted of ammonia, is routed via line 4, pump P1 and line 2 to R1, where it reacts with the ammonia from line 1 to produce the former ammonium hydroxide solution, releasing the heat of reaction previously acquired in F1 from the warm sea water. The ammonium hydroxide solution returns via line 3 to F1 to complete the cycle which may be repeated again and again. The heat released at a temperature substantially above the temperature of the warm sea water, is transferred through heat conductive means to fractionator F2 in the second TIS stage. A gas not chemically active in the system, e.g. hydrogen, is maintained in vessel V1 and traverses line 5 between F1 and R1 to equalize pressures in the system, thereby reducing pumping energy requirements.
In F2 the heat from R1 separates ammonia gas from a solution of ammonium hydroxide; the ammonia flows via line 11 to R2. Solution depleted of ammonia flows from F2 via line 14, pump P2 and line 12 to R2 where it reacts with ammonia to produce ammonium hydroxide solution enriched in ammonia, releasing heat at a temperature substantially higher than that in F2. The ammonium hydroxide solution cycles back to F2; and the heat evaporates a working fluid, e.g. ammonia, in evaporator E in a closed Rankine cycle. The ammonia gas flows via line 24 to turbine T in which it expands and cools and drives the turbine, exiting through line 21 to condenser C. After condensation to liquid phase in C, the ammonia is cycled via line 22, pump P3 and line 23 back to E.
The mechanical energy from T may be used directly or to manufacture electricity as diagrammed. Using the same amount of heat and under conditions in which the cooling temperature in the condenser remains the same, the amount of mechanical energy available from a Rankine cycle turbine is increased when the temperature in the evaporator is increased. Theoretically, the maximum thermal efficiency, the efficiency of conversion of heat into mechanical energy, in the Rankine cycle is: ##EQU1## where the T values are in absolute temperature units; thus a substantial increase in thermal efficiency may be realized with higher evaporator temperatures.
In FIG. 2 only major functional units and relationships are diagrammed and heat exchanges between process lines are not shown. The TIS diagrammed in FIG. 1, showing more detail, is essentially the same conceptual design as each stage in FIG. 2; the extra detail is merely illustrative since several methods may be used in implementing the process.
Estimated flow specifications for a 100 MWe OTEC plant and using the one-stage TIS system diagrammed in FIG. 1 are listed in Table 1. Specifications for a 100 MWe OTEC plant using the two-stage TIS system diagrammed in FIG. 2 are listed in Table 2.
Values of performance characteristics of both one and two-stage TIS-assisted plants are compared in Table 3 with a conventional Rankine cycle plant using ammonia as a working fluid. Thermal efficiency of the one-stage TIS plant is three times that of the conventional plant; thermal efficiency of the two-stage TIS plant is well over four times that of the conventional plant.
Selection of the number of stages to be used would depend greatly on capital costs, of course, but would also depend on the size of the warm and cold water resource, since the TIS assisted plants could produce more power from the same amount of resource heat and cooling. This would be particularly important where lake water is to be used or where thermal disturbance of ocean areas must be limited for environmental reasons.
The greatly increased thermal efficiency of the TIS plant is reflected in several highly significant savings in capital costs, as warm sea water and cold sea water flow rates are reduced by 69% and 72% respectively. This results in a comparable decrease in heat exchanger, pump, and piping costs, and with substantial savings in other capital construction. The Applied Physics Laboratory, Johns Hopkins University, estimated baseline OTEC-RCS capital costs for 1st through 6th OTEC plant ships without temperature enhancement each rated 500 MWe net. (Avery, W. H., R. W. Blevins, G. L. Dugger and E. J. Francis, 1976. Maritime and construction aspects of ocean thermal energy conversion (OTEC) plant-ships, APL/JHU Report SR 76-1A and 1-B.) OTEC estimates are summarized in Table 3 for $/kw construction of the 6th plant. A parallel estimate of TIS-RCS costs is tabulated using the assumption that $/kw are independent of size of plant, a reasonable assumption based on the premise that a more efficient plant could be made physically as large, if necessary to optimize costs, and would produce more power. For the TIS estimate, an assumption is made that unit costs for thermal equivalent transfer surfaces are the same as for the RCS; other structural component costs are estimated with less precision. When totaled, the TIS-RCS capital cost estimate is only 40% of the estimate for the power equivalent conventional RCS plant.
TABLE 1______________________________________100 MWe TIS-RCS TEC PLANT PERFORMANCE CHARACTERISTICS______________________________________t p wt % h w w-hLine °F. pisa NH.sub.3 btu/1B K lb/sec K btu/sec______________________________________1 70.0 128.8 99.99 629.1 1.536 9662 96.6 *127.8 99.99 647.9 1.536 9953 134.0 *126.8 98.63 678.6 .420 2884 203.0 131.8 19.47 135.0 2.220 3005 134.3 130.8 46.00 40.8 3.338 1366 85.0 129.8 46.00 -15.2 3.338 -517 70.0 128.8 0.01 38.1 1.803 698 70.1 133.8 0.01 38.1 1.803 699 96.6 132.8 0.01 64.6 1.803 11610 128.8 Hydro- gen11 188.00 280.0 100 687.5 1.914 131612 50.85 90.19 100 625.6 1.914 119713 50.00 89.19 100 97.9 1.914 18714 51.70 285.0 100 99.9 1.914 19115 70.00 284.0 100 120.5 1.914 23116 118.93 282.5 100 177.9 1.914 34017 118.93 281.0 100 634.0 1.914 1213(c) in 43.13 0 11.18 381.9 4270(C) out 45.82 0 13.88 381.9 5301(W) in 78.26 0 46.32 545.5 25266(W) out 76.15 0 44.21 545.5 24115Gross Power: 108.61 MWePump (C) = 2.26Pump (W) = 1.92P1 = 0.09P2 = 3.75Miscellaneous power = 0.59Net Power: 100.00 MWe______________________________________ *partial pressure of H.sub.2 is not included.
Anhydrous ammonia properties are from ASHRAE tables (ASHRAE Thermodynamic Properties of Refrigerants, 1969, Am. Soc. Heating, Refrigerating and Air-Conditioning Engineers, N.Y.); vapor pressures of ammonia solutions are from Wilson (Wilson, T. A. 1925, Total and Partial Vapor Pressures of Aqueous Ammonia Solutions, Univ. of Ill. Eng. Exp. Sta. Bull, 146); enthalpies of ammonia solutions are from Scatchard et al tables (Scatchard, George, L. F. Epstein, James Warburton, Jr. and P. J. Cody, 1947, Thermodynamic properties--saturated liquid and vapor of ammonia-water mixtures, Refrigeration Engineering 53:413-419), normalized to ASHRAE tables by adding 77.9 btu/lb multiplied by the weight fraction of ammonia in the solution.
TABLE 2______________________________________100 MWe 2 STAGE-TIS TEC PLANT PERFORMANCE CHARACTERISTICSt p h wLine °F. pisa wt % NH.sub.3 btu/lb K lb/sec w-h______________________________________1 70.0 128.8 99.99 629.1 1.126 708.396.6 *127.8 99.99 647.9 1.126 729.52 70.1 133.8 0.01 38.1 1.322 50.496.6 132.8 0.01 64.6 1.322 85.43 134.0 130.8 46.00 40.4 2.449 98.985.0 129.8 46.00 -15.2 2.449 -37.24 70.0 128.8 0.01 38.1 1.322 50.45 128.8 Hydrogen11 119.0 282.3 99.99 634.0 1.078 683.2174.2 281.3 99.99 677.7 1.078 730.312 119.1 289.3 0.01 87.1 1.265 110.2174.2 288.3 0.01 142.2 1.265 179.913 189.2 284.3 46.00 108.6 2.343 254.4134.0 283.3 46.00 40.4 2.343 94.614 119.0 282.3 0.01 87.0 1.265 110.115 Hydrogen21 50.58 90.19 100 625.07 1.103 689.522 50.00 89.19 100 97.9 1.103 108.023 53.00 593.0 100 101.3 1.103 111.787.18 590.5 100 140.25 1.103 154.724 295.0 587.78 100 733.20 1.103 808.7(C) in 43.13 0 11.18 253.5 3009(C) out 45.82 0 13.88 253.5 3736(W) in 78.26 0 46.32 380.7 17729(W) out 76.15 0 44.21 380.7 16922______________________________________ .sup.¢ Where two sets of figures are given for a line, the top set represents values on entrance and the lower set represents values after heat transfers from line 3 to lines 1 and 2 or from line 13 to lines 11, 12 and 23. *Partial pressure of hydrogen is not included.
With turbine efficiency of 0.900, generator efficiency 0.955: Gross power=108.8 MWe; net power=100 MWe.
TABLE 3______________________________________COMPARISON OF RANKINE CYCLE 100 MWeTEC PLANT OPERATING CHARACTERISTICS 100 MWE Plant Conventional One-stage Two-stageParameter Rankine TIS-Rankine TIS-Rankine______________________________________Gross power, MWe 115.45 108.61 108.80Warm water: °F. in 78.26 78.26 78.26°F. out 76.15 76.15 76.15KLB/sec flow 1601 545.5 382.8Cold water: °F. in 43.13 43.13 43.13°F. out 45.82 45.82 45.82KLB/sec flow 1209 381.9 269.2NH.sub.3 -Power cycle: 6.36 1.914 1.103KLB/secGas into turbine: °F. 70.00 188.00 295.0pisa 128.8 280.0 587.8Fluid out of 50.56 50.85 50.58turbine °F.pisa 90.15 90.19 90.19Fraction gas - X 0.973 1.000 0.9994Power - parasitic: 2.50 3.75 5.48NH.sub.3 feed, MWeCold water pumps, 7.15 2.26 1.56MWeWarm water pumps, 5.64 1.92 1.40MWeMiscellaneous, 0.16 0.68 0.36MWeThermal cycle 0.034 0.103 0.148efficiency______________________________________ | In heat transfer from a warm water source, efficiency is improved in a thermal energy conversion (TEC) by increasing the temperature of heat supplied to a turbine system substantially above the water temperature. This temperature increase is accomplished in a separate system by reacting gaseous ammonia with water to produce sensible heat at a high temperature; the ammonia is later fractionated from the water using lower temperature heat from the existing heat source. A single-stage temperature increase system (TIS), may be used or there may be an addition of a second stage for raising the temperature of the heat supply even higher. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to food processing and food processing equipment, but more particularly the present invention relates to an apparatus for the processing of crustacean claws where the removal of the outer crustacean shell is effected by grasping the claw in a rotary holder, rotating the holder, and passing the rotating holder into contact with a cutting saw to thereby make a peripheral cut in the claw crustacean shell to remove the shell and thereby expose the inner meat product.
2. Prior Art
Several devices have been patented which teach the removal of crab meat and the like from the crustacean body of several types of marine creatures. These machines are generally directed to the removal of meat from the central, main body portion of the crustacean. Examples of such crustacea processing equipment can be found in U.S. Patent and Trademark Office Class 17, Subclasses 71, 73, 74 and 48.
However, a substantial meat product is also contained in the claw portion of several crustaceans, such as crabs, crawfish, lobsters, and the like. It is this hard crustacean claw with a meat product therein, for example a crab claw, to which the present invention is directed.
Heretofore, in order to remove the upper, outer shell from a claw to expose the meat, hand processing including hand cutting of the shell was required. The resultant product, commonly called a "cocktail claw" is highly desirable but also very expensive due to the relatively low volume hand labor expenses involved.
The machine of the present invention provides for the automatic cutting of the shell for the removal of the shell from the meat of the crab claw to thereby expose the meat. Thus, a substantial amount of food product which normally would be dependent on hand processing can be processed by the machine of the present invention.
General Discussion of the Invention
The present invention provides an apparatus for the removal of a meat product from the claw of a crustacean. The apparatus is comprised generally of a rigid frame having a rotatable table mounted thereon. The table can be mounted at an angle, and has rotary claw holders pivotally attached to its peripheral edge. Rotation of the rotating table moves each rotary claw holder to a position which causes it to pivot toward the inner portion of the rotating table or the outer portion of the rotating table depending upon its position by the force of gravity.
In the preferred embodiment, each rotating claw holder pivots away from the central portion of the table under the urging of gravity when the respective claw holder is at the lower tilted portion of the rotating table. Correspondingly, each pivotally mounted rotary claw holder pivots toward the inner portion of the rotating table when that respective rotary claw holder reaches the higher portion of the tilted rotary table.
A rotary saw is fixedly attached at the upper portion of the tilted rotary table and oriented so that the pivoting of each rotary claw holder towards the inner portion of the rotating table brings a crab claw (or the like) held within its respective rotary claw holder into contact with the rotary saw. Rotation of each rotary claw holder, and the coincident cutting action of the saw, produces a peripheral cut in the hard exoskeleton of the crustacean claw.
A depth gauge can be included to fix the depth at which the peripheral cut is made to insure that only the outer exoskeleton will be cut and not the inner meat product.
In the preferred embodiment, each rotary claw holder is spun by the engagement of a sprocket (rotatably mounted to the rotary claw holder and on a common shaft therewith) with a fixed chain affixed to the machine body near the rotary saw. The rotating table moves each rotary claw holder through an arcuate path adjacent the fixed chain to thereby intermesh the sprocket and the chain and thus impart the previously described rotation to each rotary claw holder.
In the preferred embodiment only a portion of the arc of travel of the rotating table engages the area of the fixed chain, thus rotary claw holders are spun only in the vicinity of the rotary saw where the spinning action is desirable for making the required peripheral cut to each crustacean claw.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals and wherein:
FIG. 1 is a perspective view of the preferred embodiment of the apparatus of the present invention;
FIG. 2 is a partially cut-away plan view of the preferred embodiment of the present invention showing the rotating table with the cut-away portion revealing the turntable motor and gear reduction structures;
FIG. 3 is a partial, perspective view of the preferred embodiment of the apparatus of the present invention showing an individual rotary claw holder pivotally mounted on the outer peripheral edge of the rotating table;
FIG. 4 is a partial, perspective view of the apparatus of the present invention illustrating the respective rotational directions of the rotating table, the rotary claw holders and the rotary saw, during the cutting operation;
FIG. 5 is a side, cross-sectional view of the rotary claw holder of the preferred embodiment of the apparatus of the present invention;
FIG. 6 is a partial, side, cross-sectional view of the rotary claw holder of the preferred embodiment of the apparatus of the present invention showing a crab claw being held prior to the cutting operation;
FIG. 7 is a partial, side view of the rotary claw holder of the preferred embodiment of the apparatus of the present invention illustrating the peripheral cut made in a crab claw by the rotary saw and its cooperative depth gauge; and
FIG. 8 is a partial, side view of the rotary claw holder of the preferred embodiment of the apparatus of the present invention illustrating the peripheral cut made by the rotary saw and corresponding removal of the claw exoskeleton to expose the meat product.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Structure
As can best be seen by FIG. 1, the crab claw processing machine of the present invention, designated generally by the numeral 10, is comprised of a machine body or support frame 12 on which is rotatably mounted a rotating frame in the form of a table 14. The rotating table 14 is provided with a plurality of rotary claw holders 16 mounted at its peripheral edge portion.
Machine body 12 has lower leg portion 18 and an upper processing section 20. In the preferred embodiment the upper processing unit 20 is tilted with respect to legs 18, so that when the unit is placed on a substantially level floor, rotating table 14 will be oriented at a slight angle with the floor as illustrated in FIG. 1.
Turning now to FIG. 2 of the drawings, it can be seen that the peripheral edge portion of table 14 includes a lower portion 14' and is provided with a plurality of recessed notches 22 in which are pivotally mounted the aforementioned rotary claw holders 16. Each rotary claw holder 16 is allowed to pivot within notches 22 between a pair of stops 25, 26. An inspection of FIG. 3 illustrates how this pivotal movement is possible.
As can be seen in FIG. 3, each rotary claw holder 16 is provided with an attached pivot arm 30. Pivot arm 30 pivots about the centerline of shaft 33 (note FIG. 5). Shaft 33 is rotatably mounted in bearings 32, 32'. At the opposite end portion of pivot arm 30 from shaft 33 is rotary claw holder 16 which is rotatably mounted thereon.
FIG. 5 best illustrates the inner mechanical workings of rotary claw holder 16, pivot arm 30, and bearings 32, 32' with its associated shaft 33. A sprocket 34 is rotatably attached to shaft 33 on pulley 35 and rotates therewith on shaft 33 (see FIG. 5). Sprocket 34 is held in fixed engagement with pulley 35 by screw 31, both rotating freely on shaft 33. Rotary claw holder 16 is also provided with an attached pulley 36. Pulley 36 is rotably mounted in pivot arm 30 with bearings 37, 38. Drive belt 40 connects pulleys 35 and 36.
It can be seen from the foregoing that rotation of sprocket 34 and its attached pulley 35 about shaft 33 will produce rotation of pulley 36 and its attached rotary claw holder 16. It should be understood that rotation of sprocket 34, pulley 35, and pulley 36 does not prevent the independent rotation of shaft 33 within bearings 32, 32' which allows clawholder 16 to pivotally move within notch 22 of rotating table 14. The lower portion 17 of rotary claw holder (i.e., that portion below pivot arm 30 and bearings 37, 38) does not rotate within the pivot arm 30 but is fixed, unlike the claw holding portion 16.
The pivotal movement of pivot arm 30 and attached rotary claw holder 16 within notch 22 of rotating table 14 is limited by stops 25, 26. Each pivot arm 30 is provided with an outer tab 42 which stops upon hitting either stop 25 or 26, as can best be seen by examining FIGS. 2 and 5.
As illustrated best by FIG. 2, rotating table 14 is rotated in a preferably counterclockwise direction (see curved arrow, FIG. 2) by means of turntable motor 50. In the preferred embodiment turntable motor 50 is provided with a gear reduction system 52 which applies the rotational motion of turntable motor 50 to drive sprocket 54. Rotational motion of drive sprocket 54 drives chain 56 and attached fixed sprockets 57. Fixed sprockets 57 are rigidly affixed to the underside portion of rotating table 14. Rotating table 14 is rotatably mounted on central shaft 11, and it can be seen from the above that rotation of sprocket 54 drives chain 56 and attached sprockets 57 which are rigidly affixed to rotating table 14, and thereby rotate rotating table 14 about shaft 11.
Rotary saw 60 with its associated drive motor 60' are fixedly attached to upper processing unit 20 at the elevated portion of table 14. At least a portion of saw 60 projects over the notched portions 22 of rotating table 14 (see FIG. 2). As can best be seen in FIGS. 4, 7 and 8, rotating saw 60 is oriented substantially parallel to the upper surface of rotary claw holder 16 and spaced proximately thereto. Rotary saw 60 is provided with a movable, curved depth gauge stop 62 which allows adjustment of the depth of cut made by saw 60 in crab claw 64 (see FIGS. 7 and 8). To adjust the position of the depth gauge stop 62, a depth gauge adjustment knob 63 (FIG. 1) working through a worm gear drive 63' (FIG. 2) moves the curved stop 62 radially back and forth. Claw 64 is pneumatically clamped and held in rotary claw holder 16 during the cutting operation as will be described more fully hereinafter.
Each rotary claw holder 16 commences rotation when its respective sprocket 34 contacts fixed chain 70. Chain 70 is oriented to follow the arcuate path of each sprocket 34 as the sprocket 34 is carried along by rotating table 14.
The lower, pincher portions 64' of the crab claws 64 (as can be seen best by FIGS. 6-8) are clamped and held in position in the elongated or extended chamber 71 in rotary claw holder 16 by flexible diaphragm 72 in cooperation with the curved head 79 and the opposing side wall of the chamber 71. Diaphragm 72 is inflated and expanded against the pincher portion 64' of the claw 64 (see FIG. 6) by a pneumatic air system which conveys control air (see arrows, FIG. 6) to the diaphragm 72.
As can be seen best in FIG. 2, control air can be supplied by conventional means through a piping system having a regulator 74 to control the pressure of the control air. The entering air can be piped through hoses 76 to a central rotary valve 78 and therefrom routed to each respective claw holder. The rotary valve can be so designed, as is known in the art, to supply air to each rotary claw holder throughout only a portion of the rotation of table 14. As can best be seen in FIG. 2, the clamp air (that is, control air supplied to each rotary claw diaphragm 72) is off in, for example, a (125°) arc as shown in FIG. 2. Design of the rotary valve 78 will automatically turn on clamp air and hold the diaphragm in the expanded position to thereby clamp claw 64 in position with its longitudinal axis at least generally parallel to the axis of rotation of the holder 16 and the saw 60 throughout the remaining arc of travel of a respective rotary claw holder 16. It can be seen that clamp air is only required to secure claws 64 when intermeshed with chain 70 and particularly when in contact with the saw 60.
In the preferred embodiment of the present invention, gravity is utilized to swing each rotary claw holder 16 pivotally between stops 25 and 26. The sequential positions of rotary claw holder 16 is illustrated in FIG. 2 in which the portion of rotating table 14 nearest saw 60 is elevated and the portion of rotating table 14 nearest the bottom portion of FIG. 2 is lowered thereby providing a tilt to table 14. This tilted orientation of table 14 can also be seen in FIG. 1. Thus, under the influence of gravity, rotary claw holder 16 will abut outer stop 25 at the lower portion of table 14 and gradually swing towards inner stop 26 of rotary table 14. A mechanical guide 100 is included at the lower side of the machine 10 to contact the edges of the claw holders 16, letting them go down to their lower extreme position of travel gently, rather than letting them flop down all at once. Since the saw 60 is located at the elevated portion of table 14, gravity will urge rotary claw holders towards saw 60 as each rotary claw holder approaches the saw 60. An important element of engineering design will be to so dimension and size rotary claw holders 16 that gravity will force crab claw 64 against saw 60 with sufficient force to enable a peripheral cut to be made in claw 64 by saw 60 as rotary claw holder 16 spins. (Note that in FIG. 2, no claw 64 is contained in claw holders 16; hence, claw holders 16 fall under saw 60 and depth gauge 62.)
It is noted that, in the preferred embodiment illustrated, the plane in which the pivot arms 30 move and the planes of rotation of the table 14 and the saw 60 are all parallel, while the pivot axis at shaft 33, and the axes of rotation of the claw holders 16, the table 14 and the saw 60 are also parallel.
Moving parts, such as saw 60 and sprockets 34 (when engaging chain 70) can be protectively covered by adding housing 80 to upper processing unit 20. Housing 80 does not cover that portion of the apparatus of the present invention 10 which is not in direct rotary contact with turntable motor 50 or saw 60, allowing an operator to add claws 64 to be processed, or to remove claws 64 which have been cut and are ready for shipment as a food product.
Although many cut claw shells come off naturally during the movement of the machine 10, auxiliary ejector means could be included if desired to positively eject the cut shells from the claws.
Operation
FIGS. 2 and 4 best illustrate the rotational movements which occur in the operation of the apparatus of the present invention. Turntable motor 50 is the source of rotational energy to the entire apparatus. Motor 40 through gear reduction system 52 imparts rotary motion to sprocket 54 which drives chain 56. Chain 56 engages a plurality of fixed sprockets 56 which are rigidly affixed and attached to rotational table 14. Thus, rotation of sprocket 54 spins rotational table 14. Thus, rotation of sprocket 54 spins rotational table 14 about its central axis 11.
This rotation of table 54 additionally provides a rotational energy to rotate each respective rotary claw holder 16. Each rotary claw holder is rotated through a path of arcuate travel by rotating table 14. As can best be seen by FIG. 2, sprocket 34 engages chain 70 as rotational table 14 moves each respective rotary claw holder towards the fixed chain 70. The engagement of chain 70 by sprocket 34 and the corresponding movement of the sprocket 34 down the chain produces rotary motion to sprocket 34 and its attached pulley 35, which drives belt 40 and thus pulley 36 of rotary claw holder 16 (note FIG. 4). It can be seen by one skilled in the art that rotary claw holder 16 will spin as long as sprocket 34 is in cooperable engagement with chain 70.
A second type of motion which occurs in the operation of the present invention is the pivotal motion of rotary claw holder 16 within its respective recessed notch 22 at the outer periphery of rotary table 14. Pivotal motion of rotary claw holder 16 is affected by the movement of pivot arm 30 to which each rotary claw holder is attached on shaft 33. The pivoting of rotary claw holder 16 about the center of shaft 33 is effected by the force which gravity exerts on each rotary claw holder.
FIG. 2 illustrates the respective positions which each rotary claw holder 16 will maintain under the influence of gravity as each respective claw holder 16 is rotated (360°) about the central shaft 11 of rotating table 14. It can be seen by one skilled in the art that each rotary claw holder 16 will pivot towards outer stop 25 at the lower elevational portion of rotary table 14 and towards inner stop 26 at the upper elevational portion of rotational table 14. At the upper elevational portion of table 14, saw 60 makes the peripheral cut which is desired to process the crab meat as the rotary claw holder brings the claw 64 into engagement with saw 60.
FIG. 2 illustrates the motion of rotary claw holder 16 without a crab claw contained therein, thus, as can be seen in FIG. 2, each rotary claw holder passes underneath blade 61 of saw 60 rather than stopping at its outer edge. However, FIG. 7 illustrates the method in which the peripheral cut is made. When a rotary claw holder is brought into contact with the blade 61 of saw 60, claw 64 will abut and contact blade 61 of saw 60. Depth gauge 62 additionally engages claw 64 when saw 60 begins to cut into claw 61 (note FIG. 7). Thus, it can be seen that depth gauge 62 by abutting claw 64 fixes the depth at which blade 61 can cut into the claw 64. It would be preferable for the depth gauge 62 to be so adjusted that only the exoskeletal portion of claw 64 is cut, thereby preventing damage by saw blade 61 to the meat portion 65 (see FIG. 8) of claw 64.
It is desirable during this cutting operation, in which a peripheral cut is made around claw 64, that claw 64 is sufficiently clamped and held in place inside rotary claw holder 16. Diaphragm 72 performs this task. As can best be seen in FIGS. 5 and 6, each diaphragm 72 is pneumatically activated by control air supplied through clamp air line 75. Conventional mechanical seals 82 can be provided between the rotational connections of rotary claw holder 16 to prevent leakage of clamp air through clamp air line 75. Clamp air can be supplied through rotary valve 78 to each rotary claw holder 16 during the portion of the arcuate path each rotary claw holder makes when in engagement with chain 70. FIG. 2 illustrates that portion of the arcuate path of rotary claw holder 16 when the clamp air supply is normally off in the apparatus of the present invention.
Exemplary Dimensions
Exemplary details of a machine 10 for an embodiment which has been built and successfully tested are outlined below:
______________________________________angle of inclination of table14 to the horizontal adjustable 0+-30°15° ) (e.g. 10°diameter of table 14 48"length of pivot arm 30 41/8" (centerline to centerline)weight of claw holder 16 approximately 16 oz.depth of elongated holderchamber 71 2"lateral dimensions ofchamber 71 1/2" × 1"air pressure in line 75 approximately 20 PSIspeed of rotation of table14 1 to 5 RPMspeed of rotation of saw 60 3600 RPM______________________________________
Exemplary Variations
Although the embodiment described in detail above is considered preferred and quite satisfactory, many variations in approach and concept are of course possible. Thus, rather than positioning the rotary saw 60 within the arc defined by the travel of the holders 16 at the apogee of the travel, the saw could be positioned outside the arc at the lower, nadir of travel, and if a mechanical system were used for urging the holders toward the saw, it could be positioned on either side of travel. Additionally, it is possible to use multiple saws or cutting means other than rotary saws.
Thus, although a particular detailed embodiment of the crab claw processing apparatus has been described and illustrated, it should be understood that the invention is not restricted to the details of the preferred embodiment, and many changes in the design, configurations and dimensions are possible without departing from the scope of the invention. It should also be understood that, although crab claws have been processed successfully with the present invention and is thus considered the preferred, proven application, the present invention is applicable to other crustaceans such as for example lobsters, crawfish, etc., and the like. | A crab claw processing machine for cutting and removal of the shell comprising a machine body having a rotating table mounted thereon. The rotating table has a plurality of rotary claw holders provided with individual drive sprockets mounted at its peripheral edge portion, each rotary claw holder being capable of holding a crab claw to be processed. As the rotating table is spun by a power source, such as an electric motor, the sprockets of each peripherally placed rotary claw holder engage a fixed drive chain which spins the respective sprocket rotary claw holder, and the crab claw contained therein. Each rotary claw holder and its contained crab claw are sequentially brought in to proximity with a high-speed rotating saw capable of cutting the claw. The saw can be provided with a gauge for controlling the depth of the cut. As the rotary claw holder brings the claw in contact with the saw, the spinning action of the rotary claw holder in cooperation with the cutting action of the saw to a desired depth (as set by the depth gauge), combine to make a peripheral cut through the outer hard crustacean body portion of the crab claw, thereby exposing the meat food product. | 0 |
BACKGROUND OF INVENTION
[0001] The present invention is a method for the secure downloading of files over the Internet. In particular, the present invention relates to a method for limiting the window of time when files can be downloaded over the Internet.
[0002] The present invention reduces the risk of hacking attacks on managed devices that are downloading configuration files from an Internet Service Provider (ISP) data center by providing a tool to manage these risks. This is a significant security issue that needs to be addressed by the industry in order to reduce the disruptions caused by unauthorized use of systems by hackers.
[0003] The installation and initialization of devices that are remotely managed can be expensive, especially for users who have limited information technology (IT) resources. If a device manufacturer sends a technician to a user's facility to install a device and load the configuration file, it can be very costly. Many manufacturers of devices have found it to be more cost efficient to download configuration files via the Internet. For example, one of the services that ISPs provide for their customers is the remote management of routers connected to the Internet from the ISP data center. When a new managed device is shipped to a customer site and needs to be installed, a configuration file is downloaded from the data center to the device (e.g., a network router) over the Internet. This eliminates the need for a costly staging area. The user only has to connect the device to a power source and the Internet. The manufacturer does not have to send a technician to the remotely located device and, in most cases, the user does not need to have trained IT personnel present during the downloading.
[0004] When a customer of a network services provider, such as an ISP, purchases services, the provider often provides the customer with a managed device for accessing the provider's services over the Internet. The services provider purchases the managed device from a device manufacturer and has it shipped to the customer's facility where it is installed by the customer. The initial installation usually includes connecting the managed device to a power supply and the Internet. However, before the managed device can be operable, certain software programs, such as configuration files, have to be installed to allow the managed device to communicate with the service provider's network and/or database.
[0005] There are several ways for configuration files and other operating files to be downloaded to a managed device. The files can be downloaded at the manufacturer's factory for an additional charge. This would increase the purchase price of the equipment and pose new security risks at the manufacturer's factory and when the device loaded with the software was shipped. The risk is increased even more when the manufacturer is located outside of the United States. The managed device could be stolen during shipment to the customer or a hacker could gain access to the device and copy the configuration file. The managed device could also be shipped to the service provider for downloading of the configuration file, but this would also result in additional costs and security risks when the device was shipped to the customer. Another option, is to have the service provider send an IT person to the customer's facility and directly download the configuration file to the managed device. This avoids the security risks, but it is significantly more costly.
[0006] Service providers have found that the most cost effective and easiest method of downloading a configuration file to a managed device is over the Internet. The managed device is installed by the customer and connected to the Internet. A start-up or initialization program loaded onto the managed device by the manufacturer then connects the managed device to the service provider's database over the Internet and the configuration file is automatically downloaded. Such systems are disclosed in U.S. Pat. No. 6,067,582 to Smith et al. and U.S. Pat. No. 6,587,874 to Golla et al., both of which are incorporated herein in their entirety. However, this system requires the service provider to have the configuration file available for downloading for an unacceptably long period of time. Since the downloading is accomplished automatically over the Internet, the configuration file can still be accessed even after the customer has successfully downloaded the file to the managed device. The configuration file remains accessible until it is removed as part of a scheduled housekeeping of the service provider's database. In some cases, this may result in the configuration file being unnecessarily exposed to illegal downloading by hackers for a period of days or even weeks.
[0007] The methods presently used for downloading configuration files over the Internet pose security concerns since the files can easily be intercepted by hackers when they are being made available for downloading by the customer. The hackers can then configure their own computer (or router) with the intercepted configuration file and the ID of the customer's device to create a secure tunnel between the hacker's computer and the data center. This allows a hacker unauthorized and unrestricted access to privileged information in the entire client network.
[0008] The methods presently being used for downloading and uploading files over the Internet do not provide security from hackers. For example, Cisco Systems has the IE2100 device to do initial configuration of managed devices but it does not address security concerns. Typical methods for identifying managed devices use the physical box serial number which is hard coded on the device in the form of a metal plate affixed to the chassis. When the serial number is transmitted to the manufacturer, it allows the manufacturer to identify the configuration file that will be downloaded to the managed device. The problem facing device manufacturers is how to make files downloaded over the Internet more secure so that hackers will not be able to intercept them when they are made available for downloading by authorized users.
SUMMARY OF THE INVENTION
[0009] In accordance with the present invention, a method for securely downloading files from a database to a managed device is provided. The method includes selecting a managed device, preferably a router, for interfacing with networks or devices over the Internet; affixing a unique identification number to the device; creating a file, preferably a configuration file, for the managed device on a database, wherein the file can be downloaded over the Internet to the managed device; creating an access verification program for downloading the file, wherein the access verification program permits a user of the managed device at a remote location to access the file over the Internet by entering the unique identification number, and wherein the access verification program permits the user to download the file over the Internet for a period of time; reading the unique identification number by the user; entering the unique identification number into the access verification program by the user; verifying the unique identification number using the access verification program; permitting access to the database by the user for downloading the file for a period of time; downloading the file from the database to the managed device; and blocking access to the database for downloading the file.
[0010] In a preferred embodiment of the present invention, the unique identification number is the serial number of the managed device. In another embodiment the managed device is assigned a password that is used in combination with the unique identification number for access verification.
[0011] In one embodiment, the period of time during which the database can be accessed for downloading the file is predetermined when the access program is created. A preferred period of time is less than four hours and a most preferred period of time is less than one hour. In another embodiment, the period of time is selected by the creator of the access verification program or the user.
[0012] The user can use a portable device to read the unique identification number from the managed device which communicates with the service provider's data center. Preferred portable devices include a bar code scanner to read the managed device's unique identification number. In one embodiment, the password is also entered in the portable device, either by using a keyboard or by swiping a bar code containing the password. The bar code readers that can be used are well known to those skilled in the art and include bar code scanners manufactured by Symbol Technologies, Inc., Holtsville, N.Y. The unique identification number and the password are then downloaded from the portable device to the database. This can be accomplished using a wired (e.g., modem, internet or telephone line) or wireless (e.g., LAN, WAN or cell phone) connection. In one embodiment, access to the database for downloading the file is blocked after the file has been downloaded and in another embodiment, access to the database for downloading the file is blocked after the time period has expired.
[0013] By limiting access to the database for downloading files to managed devices, the present invention makes it more difficult for hackers to gain access to the files. The files are only available for downloading for a very brief period of time before access is blocked. This provides increased security for the database and the files that are downloaded.
BRIEF DESCRIPTION OF THE FIGURES
[0014] Other objects and many attendant features of this invention will be readily appreciated as the invention becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0015] FIG. 1 is a flow chart showing the method of the present invention for securely downloading files from a database to a managed device.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention is a method for limiting access to files that are made available for downloading over the Internet. The longer files are available for downloading, the more likely it is that they will be downloaded by unauthorized persons. In order to limit unauthorized downloading, the method of the present invention limits the window of time when the files are available to a remote user for downloading.
[0017] Security is all about risk management and providing systems which minimize a computer network's exposure to risk. The present invention increases security, without the need to use any encryption mechanisms or devices that are hard to maintain, by reducing the time that the configuration file is available for downloading on the Internet. When a service provider makes configuration file (a file that contains configuration information for a particular program—when the program is executed, it consults the configuration file to see what parameters are in effect) or other files available for downloading by a customer over the Internet, the file can be accessed by anyone who has the password and/or access code. This leaves an open door into the service provider's database and allows unauthorized hackers to downloading sensitive files. The method of the present invention opens the door only after the customer has signaled that it is ready to download the files and closes the door immediately after the downloading has been successfully, or in one embodiment unsuccessfully, completed. This allows hackers only a brief opportunity to gain unauthorized access to files in the service provider's database.
[0018] The present invention limits the exposure of downloadable files to hackers by reducing the period of time that the file is available for downloading from the data center to an authorized user's managed device. As used in the present invention, the term managed device is any piece of equipment that sits on a data network and runs Simple Network Management Protocol (SNMP, a protocol used to exchange data about network activity), for example, computers, printers, hosts or routers.
[0019] For illustrative purposes, the following description of the invention assumes that the managed device is a router and the service provider is an ISP. In accordance with the present invention, the process used by a router to download its configuration file from the ISP data center is shown in the flow chart in FIG. 1 and has the following steps:
[0020] (1) A customer contacts an ISP and purchases internet services which require the customer's network or computer system to interface with the ISP using a router (or a similar managed device).
[0021] (2) The ISP selects a router based on the requirements of the customers application and orders the device from the device manufacturer (e.g., a router from Cisco). The device manufacturer confirms the order and provides the ISP with the serial number of the router. When the assembly of the router is completed, a nameplate is permanently affixed to the chassis of the router and it contains pertinent information about the device, including the serial number. This information can be in a text form and/or contained in a bar code.
[0022] (3) The ISP data center creates a configuration file for the router according to the requirements of the customer's application. (In some embodiments, additional files may also be created for downloading to the customer's device.) The serial number corresponding to the device is included in the file's access information program to ensure that the configuration file is dedicated to the correct router. The configuration file is stored on the ISP's database but it is not immediately made available for downloading by the customer. If a download request for a managed device with this serial number arrives at the data center, it will be refused. In a preferred embodiment, the ISP data center includes the date when the router is scheduled to be delivered to the customer's facility in the access program and prevents access for downloading the configuration file until after that date. The ISP data center also creates an access verification program and programs the identification number and/or password for a portable device into the access program. The portable device is sent to the customer where it is used to read the unique identification number of the managed device (i.e., the router) when the managed device arrives at the customer's facility.
[0023] (4) The router is shipped to the customer's facility from the device manufacturer. In one embodiment of the present invention, the shipper reports delivery to the manufacturer and/or the ISP data center using a package tracking system which sends an e-mail. Upon receipt of the e-mail message, the ISP data center permits the customer access for the verification step described below.
[0024] (5) The customer reads the serial number of the router directly from the nameplate into the portable device (in some embodiments the customer also enters a password), preferably a wireless device that transmits the serial number to the data center for verification. Such a device is disclosed in U.S. Pat. No. 6,665,745 to Masterson, et al. which is incorporated herein in its entirety. The information is entered on the portable device using a keypad. In a preferred embodiment of the present invention, a bar code scanner is used to read the serial number and/or password.
[0025] (6) The portable device transmits the serial number of the router (and, in a preferred embodiment, the password) to the ISP data center via a wireless or wired connection. In some embodiments of the present invention, other means may be used for reading the serial number and transmitting it to the ISP data center. For example, the customer could write down the serial number and transmit it in combination with a password to the ISP data center using the keypad of a touch-tone telephone or an Internet connection. Those skilled in the art will appreciate that there are numerous methods for communicating a series of alphanumeric characters to a remote data center.
[0026] (7) The ISP data center authenticates the portable device (or password), reads the serial number of the router, and then enables the configuration file of the router for the customer's application so that it is available for downloading via the Internet. The configuration file is enabled for a predetermined period of time. In some embodiments of the present invention, the customer determines the period of time that the configuration file will be available for downloading when he submits the serial number to the data center. If the configuration file has not been downloaded within the prescribed time period, access to the configuration file is disabled and the customer has to resubmit the verification information to make the configuration file available for downloading a second time. This can be done either manually or by using the portable device to resubmit the serial number. In a preferred embodiment of the present invention, once the predetermined time period expires, the configuration file cannot be made available by verification procedure using the portable device and the customer must contact the ISP's data center to request access for downloading the files.
[0027] (8) The customer connects the router to a power source and the Internet and turns it on. The router automatically dials up and connects to the ISP data center via the Internet connection and makes a request to download the configuration file. In a preferred embodiment, the customer is provided with a password which is used in combination with the serial number to verify that the customer has authorization to download the files. When the customer is provided with a portable verification device, the password is either programmed into the portable device by the IPS data center before it is shipped to the customer or the password is transmitted to the customer who enters it into the portable device. When the portable verification device includes a bar code scanner, the IPS data center can send a bar code to the customer containing the password. The customer can then easily scan the password into the portable device.
[0028] (9) The ISP data center compares the serial number and password submitted by the customer to the information entered into its access program. If the access program authenticates the serial number and password, the ISP data center makes the configuration file available for downloading over the Internet. Typically, the customer will have 24 to 72 hours to complete the downloading of the configuration file. In a preferred embodiment, the customer will have 2 to 4 hours to download the files and in a most preferred embodiment the customer will have 30 to 60 minutes to download the files. The period of time that the configuration file is available for downloading can be predetermined by the ISP data center or it can be agreed to in advance between the data center and the customer. Since the customer and the ISP are both concerned about hackers accessing the configuration file, it is desirable to minimize the period of time when the files are accessible. In one embodiment, the customer selects the time period when the serial number is submitted for authentication. This can be done using a prompt from the data center access program. Once the downloading of a file is begun, access to the files will not be disabled until the download is completed. In one embodiment of the present invention, access to download the configuration file is not terminated until the time period has expired. In another embodiment, as soon as the download is completed, the ISP data center disables the downloading of the configuration file. In a most preferred embodiment of the present invention, if the customer has not successfully downloaded the configuration file and access to download has been disabled but has not timed out, the customer can resubmit the serial number and password a second time and make a second attempt to download the file.
[0029] Reducing the window of time that the ISP data center permits access to a configuration file for downloading significantly increases the security of files downloaded from the ISP's data center. In order to access the ISP data center and download files, a hacker has to know the serial number of a device and the password, as well as the date and time when the configuration file will be available for downloading by the customer. Accordingly, the present invention improves the security of files downloaded over the Internet by reducing the period of time when files are susceptible to unauthorized access by hackers.
[0030] Thus, while there have been described the preferred embodiments of the present invention, those skilled in the art will realize that other embodiments can be made without departing from the spirit of the invention, and it is intended to include all such further modifications and changes as come within the true scope of the claims set forth herein. | A method for securely downloading files from a database to a managed device that includes selecting a managed device; affixing a unique identification number to the device; creating a file for the managed device on a database, wherein the file can be downloaded over the Internet; creating an access verification program for downloading the file which permits a user of the managed device to access and download the file over the Internet for a period of time; reading the unique identification number by the user; entering the unique identification number into the access verification program by the user; verifying the unique identification number using the access verification program; permitting access to the database by the user for downloading the file for a period of time; downloading the file from the database to the managed device; and blocking access to the database for downloading the file. | 6 |
BACKGROUND OF THE INVENTION 1. Field of the Invention
This invention relates to printers and has particular reference to printers of the dot matrix type embodying wire or like printing elements. 2. Description of the Prior Art
High speed wire matrix printers having a printer head movable along the plane of the paper for serially printing characters have been in extensive use heretofore. Such printer heads generally comprise a plurality of vertically aligned print wires operable endwise by solenoids or similar actuators.
Although such printers are generally satisfactory, they have been expensive to manufacture and have been limited in speed due to inertia and momentum of certain moving parts, particularly the printer head, since the latter must bodily transport the relatively heavy solenoids or other wire actuators across the plane of the paper.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide a high speed serially operable wire printer.
Another object is to reduce the inertia and momentum forces of the moving parts of a printer of the above type.
Another object is to provide a simple and inexpensive yet highly reliable serially operable wire printer.
The printer of the present invention, in its broader aspects, comprises a linear guide means extending adjacent and parallel to the plane of the paper at the print line and having pivotal means movable therealong for guiding the rear or printing end of a wire print head. The opposite and heavier end of the print head is pivotally supported and is permitted movement toward and away from the plane of the paper. Accordingly, the heavier end of the head is located adjacent the forward pivotal support and therefore is subject to less inertia and momentum forces than the relatively light rear end which is transported along the printing line. This construction also reduces any binding tendencies which occur in printers of the type wherein the print head is mounted for sliding movement along two or more shafts.
A further feature of this construction is that the flexible electrical conductors for energizing the solenoids need flex through a shorter distance of travel than would be the case if the head were bodily transported between the extremes of its travel.
The manner in which the above and other objects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a wire printer embodying a preferred form of the present invention.
FIG. 2 is a fragmentary sectional view taken along the line 2--2 of FIG. 5.
FIG. 3 is a top plan view, partly in section, of the printer.
FIG. 4 is a side elevation view, partly in section.
FIG. 5 is a transverse sectional view through the printer and is taken along the line 5--5 of FIG. 4.
FIG. 6 is a transverse sectional view taken along the line 6--6 of FIG. 4, illustrating the support for the magnetic control tape.
FIG. 7 is an enlarged fragmentary sectional view illustrating the drive means for the paper and ink printing ribbon and is taken along the line 7--7 of FIG. 3.
FIG. 8 is a perspective view of the printing ribbon cassette.
FIG. 9 is a front view of the ribbon cassette and is taken in the direction of the arrow 9 of FIG. 8.
FIG. 10 is a perspective view of a section of the magnetic control tape.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the printer comprises a base 11 having spaced side frames 12 and 13 integral with the rear end thereof. A transversely extending guide channel 14 is suitably secured to the base 11 and the sides of the channel slideably receive a traveling nut 15 (see FIGS. 2, 4 and 5 in particular) which is normally screw threaded over an intermediate screw threaded section 16 of a shaft 17. The latter has unthreaded end sections 18 and 20 at opposite ends of the threaded section, and is rotatably mounted in bearings formed in the side frames 12 and 13.
A reversible stepper motor 21 of conventional construction is suitably attached to the side frame 12 and is coupled to the shaft 17 to incrementally rotate the same in either of opposite directions under control of suitable control circuitry, not shown.
A transversely extending slot 22 is formed in the upper side of the nut 15 to pivotally receive a pin 23 secured to the rear end of a wire print head generally indicated at 24. The latter is of conventional construction comprising a relatively light, substantially triangular frame 25 having bearing means at its rear or printing end 26 to slideably support the printing ends of a series of small vertically aligned printing wires 27. Such wires are guided by the frame 25 for endwise movement and are attached at their foward ends to the armatures 28 of relatively heavy solenoids 30 attached to the frame 25. Flexible electrical conductors, partly shown at 31, are connected between the solenoids 30 and a suitable control circuitry (not shown) to energize the solenoids in different combinations as the rear end of the head sweeps across the print line to print desired character patterns. Although seven printing wires 27 and corresponding number of solenoids 30 are shown, nine or more wires and respective solenoids may also be employed.
The rear end 26 of the print head 24 is pivotally supported by the pin 23 which rests on the bottom of the slot 22 in nut 15, and a roller 32 which engages between the sides of channel 14, is rotatably mounted on pin 23 to guide the rear end 26 of the print head in a linear path along the plane of a thermo-sensitive paper strip 33 at the printing line.
The forward end of the print head 24 has a bracket 34 suitably secured to the underside thereof and pivotally mounted at 35 on a link 36 which, in turn, is pivoted on a fulcrum pin 37 attached to the base 11.
It will be noted that the link 36 extends at least substantially parallel to the axis of shaft 17 so as to guide the forward end of the print head 24 in a direction substantially at right angles to shaft 17 as the head pivots during its travel. Since the relatively heavy solenoids 31 are located adjacent the pivot point 35 and therefore bodily move through only a small distance, the inertia and momentum forces developed thereby at high printing speeds will be much less than if they were bodily transported the entire width of the character line to be printed.
A box-like compartment 40 is formed at the rear of the printer to receive a cassette 41 containing an inked printing ribbon 42 (FIGS. 1, 3, 4, 8 and 9). Such compartment comprises a base wall 43 and fore and aft walls 44 and 45, respectively. Walls 43 and 45 are suitably secured to the side frames 12 and 13 but the wall 44 is somewhat shorter, as seen in FIG. 3, and forms a printing platen against which the paper strip 33 rests during printing, the strip 33 passing between the platen wall 44 and a strand of the printing ribbon 42. Thus, the platen wall 44 defines the printing plane of the paper.
When the motor 21 is rotated, the rear end 26 of the print head 24 is transported between its full line position shown in FIG. 3, at one extreme of its travel, and its dot-dash line position 24a at the opposite extreme of its travel. During such movement, the print head 25 rocks about its pivot connection 35 while its rear end is constrained by roller 32 to move along the channel 14. Some slight fore and aft movement is also imparted to pivot 35. Although, due to the rocking of the head 24 about pivot 35, the rear printing tips of the wires 27 will move a slightly greater distance when the head 25 is at the extremes of its travel than when it is midway between such extremes, such difference in movement is relatively small and those print heads of which I am aware will permit such additional movement of the wires so that an even print will occur across the entire line of print.
As seen in FIGS. 2, 3 and 5 the unthreaded portions 18 and 20 of the shaft 17 each has a diameter equal to the root diameter "d" of the threaded portion 16. Compression springs 46 and 47 are fitted over the unthreaded shaft sections 18 and 20 and are compressed between the side frames 12, 13 and annular disks 48 and 50, respectively, which are slideable on the unthreaded shaft sections and normally engage the corresponding end shoulders 49 of the threaded section 16, as seen in FIG. 2.
When the head 25 approaches either end of its travel, the nut 15 strikes the adjacent disk 48 or 50, compressing the associated spring and moving onto the adjacent unthreaded shaft section 18 or 20. At the extreme end of its travel, the nut 15 moves completely off the threaded shaft section but is held against the shoulder 49 thereof by the compressed spring 46 or 47. Thus, any continued rotation of the shaft 17 in the same direction will not drive the head 24 further, but when the motor is reversed to drive the shaft 17 in the opposite direction, the compressed spring will return the nut 15 into threaded engagement with the threaded portion 16 to return the head in the opposite direction. Thus, vertical alignment of the printed characters in different print lines can be readily maintained.
A guide rail 51 (FIGS. 1, 4 and 5) is secured to the side frames 12 and 13 and slideably engages the upper surface of the print head 24 adjacent its rear end 26 to maintain the pivot pin 23 at the bottom of slot 22.
Describing now the paper feeding mechanism, it will be noted in FIG. 4 that the paper strip 33 is fed from a suitable supply roll (not shown) and is guided over a guide member 52 and between a feed roll 53 of elastomeric material and a pressure roll 54, from whence it is guided upwardly over the platen wall 44. Feed roll 53 is carried by a shaft 55 (see also FIG. 7) which also carries a spur gear 56 and a ratchet 57. The latter is normally detented by a spring driven centralizer 58 and is incrementally rotated by a formed tooth 59 of a pawl 60 (see also FIG. 4) pivotally connected at 61 to the armature 62 of a solenoid 63 mounted on the base 11. A tension spring 64 normally holds the pawl 60 rearwardly and upwardly in engagement with a tooth of the ratchet 57. Upon application of a signal from the control circuitry to the solenoid 63, the pawl 60 will incrementally advance the ratchet 57 to advance the paper strip 33 from one print line position to the next.
Describing now the construction of the ribbon cassette 41, reference is had particularly to FIGS. 1, 3, 4, 7, 8 and 9 wherein it will be seen that the cassette is preferably formed of plastic and is enclosed by top and bottom walls 65, 66, side walls 67, 68 and front and rear walls 70 and 71. A handle 69 is mounted on the top wall 65 to enable the cassette to be readily lowered into the compartment 40 or to be removed therefrom.
The printing ribbon 42 is in an endless form and is bunched within the cassette. The ribbon exits through a slot 73 from whence it is guided around a first guide bracket 75 on the cassette wall 70, over the paper strip 33 and is then guided over a second guide bracket 74 on wall 70 and reenters through a second slot 76 where it is engaged between a feed roll 77 of elastomeric material and a pressure roll 78 within the cassette. As seen in FIG. 7, the feed roll 77 is mounted on a shaft 78 journalled in the top and bottom walls 65 and 66, respectively, of the cassette, and has a spur gear 80 secured thereto.
When the cassette 41 is mounted within the compartment 40, the gear 80 meshes at right angles with gear 56 to establish a drive between the paper feed shaft 55 and the ribbon whereby the ribbon is incrementally advanced each time the paper strip 33 itself is advanced.
In order to properly locate the cassette 41 within the compartment 40, locating tabs 81 and 82 are formed on the forward cassette wall 70 to engage behind the platen wall 44. The ribbon guiding brackets 74 and 75 engage the opposite ends of the platen wall 44 and thus locate the cassette in proper position endwise. Two sets of tabs 83 and 84 (FIG. 8) extend forwardly from the opposite ends of the cassette to cover the adjacent portions of the ribbon and thus protect the ribbon when handling the cassette out of the compartment 40. A second short bottom wall section 85 (FIG. 7) extends below the gear 80 to likewise protect the latter during handling of the cassette.
Means are provided to effect reversal of the motor 21 when the print head 24 reaches the extremes of its travel and to properly locate the dot patterns forming the printed characters, i.e. 86 (FIG. 1) across the paper strip 33. For this purpose, a strip 87 of magnetic tape, FIGS. 1, 3, 4, 6 and 10 is extended across the path of a multi-track magnetic read head 88 suitably attached to the underside of the print head 24. Such head is of conventional construction having four spaced track reading sections 89 thereon. The ends of the magnetic strip 87 are secured within slits 90 formed in arms 91 of a U-shaped bracket 92 which is secured by screws 93 to the base 11. The arms 91 are somewhat flexible and thus maintain the strip 87 under constant tension and in engagement with the read head 88.
As shown in FIG. 10, magnetic marks 94 are recorded in different tracks along the length of strip 87. For example, the lower track 95 contains two spaced marks 96 indicating the extremes of travel of the head 25. When one of such marks is sensed by the appropriate read section of the read head 88, the control circuitry for the motor 21 will be energized to reverse the direction of rotation of the latter. The upper track 97 contains a series of regularly spaced marks which, when the aligned read section 89 of the read head 88 is electrically selected, controls the timing of selected combinations of the print wires 27 to print and thus form the printed characters. This may form, for example, 12 characters per inch whereas the remaining tracks 98 and 100 contain marks which can control the spacing of the printed characters in different desired manners when the corresponding read head sections 89 are electrically selected. The bracket 92 carrying strip 87 may be readily replaced with other brackets carrying strips having different desired tracks or marks or the existing magnetic marks may be readily erased and recorded as desired by methods well known in the art. | Guide means for a serially operable wire matrix printer head wherein a guide is provided for linearly and pivotally guiding the printing end of the head adjacent and parallel to the plane of the paper. Independent means are provided to pivotally support the opposite and heavier end of the head and for permitting movement of such end in a direction substantially at right angles to the plane of the paper. | 1 |
FIELD OF THE INVENTION
[0001] The present invention is related to a new and beneficial compact heat exchanger to increase fluid temperature used in a cleaning apparatus. The compact heat exchanger increases the temperature of incoming fluid within a single housing and may most preferably be used as a device which pre-heats a cleaning fluid before that fluid is passed to a primary heater. In some applications, the heat exchanger may also be used as the primary heater of a cleaning fluid. When used in either embodiment, the heat exchanger reduces fuel costs associated with heating a cleaning fluid. The heat exchanger utilizes a water jacket created by the annular space between a concentrically arranged internal housing and external housing. Cleaning fluid enters and circulates within the water jacket, where it becomes preheated, before passing to a radiator. The radiator is enclosed within the internal housing and is used to further heat fluid flowing there through. In operation, heated gas is introduced into a chamber formed within the internal housing and before entering the radiator. That heated gas thereby comes in contact with and transfers heat to the internal housing. Thus, as an incoming cleaning fluid supply is directed into the water jacket, it is preheated by heat being transferred from the internal housing to the fluid before being directly further heated within the encircled radiator.
BACKGROUND OF THE INVENTION
[0002] Cleaning devices are often used to clean items, such as motor vehicles or sidewalks. Such devices are usually mobile and are used at the site of the cleaning job. As is understood by those working in the art, cleaning fluids used in such devices typically consist of a mixture of heated water, steam, and/or a chemical solution that is delivered to an article to be cleaned by a cleaning wand assembly. While these are typical fluids, other fluids or combination of fluids, could certainly be used in a given environment. In any case, fluid supplied to the cleaning wand assembly often and preferably is heated substantially. That fluid temperature is to be maintained over a variety of operating conditions.
[0003] To heat fluid, prior art cleaning devices typically pass cleaning fluid through typical heat exchangers, causing heat applied to the exchangers (typically in the form of a heated gas) to pass from the gas to a medium (typically metal) to the fluid, resulting in heated fluid. The thermodynamic properties and functionality of heat exchangers, as well as the design and implementation of general purpose heat exchangers, is well within the knowledge of those working in this art. These artisans also understand that typically it is a heated gas which is placed in contact with the external surfaces of the heat exchanger, causing heat to transfer from the gas to the exchanger. Such gases can be super heated, such as exhaust gas exiting an internal combustion engine or gases developed for heating or merely heated gas, such as exhaust gas generated by vacuum pumps, etc.
[0004] As those working in the field understand, a number of prior art devices are directed to using available heat sources, namely, a combination of organic heat sources and various types of heat exchangers, to create both preheated and super heated cleaning fluid. For instance, U.S. Pat. No. 4,949,424 to Shero is such a system, whose disclosure is incorporated here by this reference. Shero utilizes two heat exchangers that first direct incoming fluid through the first heat exchanger, which heats the fluid to a temperature in the range of about 100 to 120° F. Next, the device directs the fluid through a second, gas-fired heat exchanger placed parallel to the first heat exchanger. The fluid is then heated to a temperature range of about 200 to 230° F. After the fluid is directed through both heat exchangers sequentially, a portion of the volume of the heated fluid is diverted back into the incoming fluid supply, causing a continuously circulating flow of somewhat heated fluid, raising incoming cold fluid temperatures. However, while the disclosed device certainly heats the incoming fluid, it does not utilize the radiator enclosed within a water jacket concept of the present invention and thus is not as efficient or compact as the system disclosed herein.
[0005] Similarly, U.S. Pat. No. 5,469,598 to Sales discloses a marginally more efficient system for heating and maintaining the heat of incoming fluids and is also incorporated into this disclosure by this reference. Sales also uses super heated exhaust gas from an internal combustion engine as the main source of heat which is supplied to a series of heat exchangers used to heat an incoming cleaning fluid. Two primary heat exchangers are again used in a parallel and sequential arrangement. A third heat exchanger is also used to preheat the fluid supply. The heat supplied to the third heat exchanger is from secondary sources, such as residual heat recovered from waste water, steam, and exhaust gas from a vacuum pump. As with the invention disclosed in Shero, Sales does not utilize the highly efficient radiator enclosed within a water jacket exchanger configuration of the present invention and thus does not use gaseous heat sources as efficiently as does the present invention or achieve desired fluid heating in a minimal amount of space.
[0006] Other prior art devices have utilized a concentric, or layered, arrangement of various heat exchanging devices to heat fluid. For instance, U.S. Pat. No. 4,023,558 to Lazardis utilizes a jacket having an inner wall and an outer wall. A fluid to be heated passes between these walls and is heated by the transfer of heat through the wall structure. A conduit bounded to the inner wall of the disclosed device conveys the hot gas towards the inner wall through a series of baffles that are placed longitudinally in sections parallel to the inner wall. The hot gas is directed through the baffles towards the inner wall, where water passing through the jacket can be heated. However, after the water is directed through the jacket, the water is not directed into the conduit for direct exposure to the hot gas and is thus inefficient. Nor is the disclosed device used in a mobile cleaning device context. Lazardis is also incorporated into this disclosure by this reference.
[0007] In U.S. Pat. No. 6,564,755 to Whelan, a water jacket is utilized to preheat a hot water system and is also incorporated into this reference. In particular, a heat exchanger surrounds a flue pipe from a furnace for preheating water. The heat exchanger includes an annular space that constitutes a sleeve, which surrounds the flue pipe to form a water jacket. Water storage tanks are connected in series and mounted around the sleeve to absorb heat from the water jacket. Water then flows through each water tank, absorbing heat which is then directed through the sleeve surrounding the flue pipe to be further heated. While this device does utilize a water jacket concept, that water jacket absorbs and transfers residual heat from the flue pipe. In other words, Whelan is a heat recovery device that uses secondary sources of heat to preheat an incoming water supply, and does not further heat a cleaning fluid with direct contact to a radiator. Whelan also does not utilize a direct source of heat, such as super heated exhaust gas from an internal combustion engine, to heat a cleaning fluid.
[0008] As described, prior art devices used in mobile cleaning systems may utilize multiple heat exchangers to directly heat an incoming fluid and/or recovered secondary gas sources to preheat an incoming fluid. These devices may also divert a portion of the heated fluid to preheat an incoming fluid. Other devices utilizing a water jacket-like mechanism to heat a fluid are not used in mobile cleaning systems. Within the context of cleaning devices, there is thus a need for a compact heat exchanger that efficiently preheat and/or heat an incoming cleaning fluid using both residual or secondary sources of heat and direct heat from the exhaust gases.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a compact heat exchanger that utilizes available heat sources more efficiently and effectively to produce heated cleaning fluid than prior art devices. The compact heat exchanger acts as both a heat recovery device to either preheat an incoming fluid, or, in some embodiments, fully heat the fluid. It is a further object of the present invention to achieve a more compact heat exchanger than previously available, such that the size of the cleaning apparatus will be reduced. These and other advantages are achieved by the device of the present invention.
[0010] The present invention preferably includes a primary super heated exhaust gas generating means, such as exhaust from an internal combustion engine. The preferred device also includes an inlet for the supply of cleaning fluid into the device and outlet for heated cleaning fluid to exit the device. The present invention also preferably includes an internal housing that substantially encloses a heat exchanging device, such as a radiator. There is also an external housing that substantially surrounds the internal housing, such that a water jacket is created in the annular space between the internal and external housing. As heated exhaust gases or other appropriate gases flow into the internal housing, heat from the exhaust gas will be transferred to the internal housing. As fluid flows into the inlet, it will be directed through the water jacket to be heated by heat transferring from the gas to the internal housing and finally to the fluid. Subsequently, that fluid will flow directly from the water jacket into the radiator where a more direct heat transfer of the heated gas will be passed to the fluid.
[0011] The novel design of the compact heat exchanger disclosed herein may utilize organic direct heat sources to preheat or fully heat cleaning fluid within a single compact heat exchanger, rather than utilizing other secondary sources of heat. The novel design thus may heat incoming cleaning fluid more efficiently than previously accomplished and allows for a more compact mobile cleaning device which reduces overall fuel consumption of a cleaning apparatus into which it may be incorporated.
[0012] The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary of the Invention, as well as in the attached drawings and the Detailed Description of the invention. No limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc., in the Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detailed Description, particularly when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions.
[0014] FIG. 1 is a schematic view of a cleaning apparatus in accordance with the present invention;
[0015] FIG. 2 is a view of one embodiment of the present invention;
[0016] FIG. 3 is a cross-sectional view of FIG. 2 of the present invention; and
[0017] FIG. 4 is a exploded view of FIG. 2 of the present invention.
[0018] To assist the reader in the understanding embodiments of the present invention, the following list of components and associated numbering found in the drawings is provided herein:
[0000]
Component #
Component Name
10
mobile cleaning apparatus
20
inlet
22
fluid box
24
pump
30
heat generating unit
50
wand assembly
100
compact heat exchanger
105
inlet pipe
110
exhaust gas inlet
111
openings
120
top cover
130
bottom cover
140
external housing
150
internal housing
160
ring
170
water jacket
180
primary heat exchanging device
185
radiator inlet
186
radiator outlet
190
intermediate pipe
195
conduit
199
exhaust pipe
200
second heat exchanger
[0019] It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted from these drawings. It should be understood, of course, that the invention is not limited to the particular embodiments illustrated in the drawings.
DETAILED DESCRIPTION
[0020] As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural functional details provided herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
[0021] A mobile cleaning apparatus 10 of the present invention is shown in FIG. 1 . An incoming fluid supply, typically water but which could be any cleaning fluid, for use in the apparatus 10 flows through inlet 20 to the fluid box 22 , which is a storage apparatus for initially holding incoming cold fluid. A pump 24 moves fluid from the fluid box 22 throughout the system. A heat generating unit 30 , such as an internal combustion engine, serves as the main source of super heated gas for use in heating fluid passing through the exchanger. Exhaust from vacuum pumps, etc. could be aggregated with these gases to increase overall gas temperature and/or volume. It should be understood that other heated gas sources could also be utilized with the invention.
[0022] A cleaning wand or tool (not shown) related to wand assembly 50 serves as the outlet for the heated fluid. It is understood by those skilled in the art that the wand assembly 50 could be replaced by any appropriate cleaning tool, such as a surface cleaner, etc.
[0023] Referring to FIGS. 2-4 , heated gases preferably generated by the heat generating unit 30 and/or other devices are supplied to a compact heat exchanger 100 through an exhaust gas inlet 110 . The compact heat exchanger 100 is preferably cylindrical in shape (though other shapes could easily accommodate the inventive aspects of the disclosed device) with a preferably cylindrical top cover 120 and bottom cover 130 . Two housings 140 and 150 , also preferably cylindrical in shape are in a concentric arrangement such that the external housing 140 substantially encloses the internal housing 150 . A ring 160 joins the external housing 140 and the internal housing 150 near the top and the base (not shown) of the internal housing 140 and external housing 150 . As shown in FIG. 3 , a water jacket 170 is created between the internal housing 140 and external housing 150 and rings 160 . A primary heat exchanging device 180 , such as a radiator, which can but need not be of a tube and fin type, lies within the internal housing 150 . The top cover 120 and bottom cover 130 enclose the primary heat exchanging device, i.e. radiator, 180 within the internal housing 150 , creating Chamber A and B. (See FIG. 3 ). Chambers A and B can be sealed, substantially sealed, or need not be sealed at all by the radiator.
[0024] In operation, fluid is supplied to inlet pipe 105 , under pressure, filling water jacket 170 . The fluid next travels via intermediate pipe 190 out of the water jacket 170 , through conduit 195 and into radiator inlet 185 . The fluid then travels through tubes of the primary heat exchanger device, or radiator 180 , exiting radiator outlet 186 , which ultimately supplies fluid to wand assembly 50 . A portion of the heated fluid exiting the radiator outlet 186 may be diverted back to the fluid box 22 .
[0025] Next, the heat generating unit 30 or other devices produce super heated gas which is supplied to exhaust gas inlet 110 and which then flow through openings 111 into Chamber A. Because the supplied gas is under pressure, it is forced from Chamber A, through primary heat exchanger device, or radiator 180 and into Chamber B, before exiting exhaust pipe 199 . As the hot gas passes through primary heat exchanger device, or radiator 180 , heat is transferred from the gas to the primary heat exchanger device's, or radiator's 180 , tubes and fins. Next, that heat is transferred from the tubes and fins to fluid traveling through the tubes. It is through this process that the cleaning fluid is primarily heated to a desired temperature, typically a preheated temperature, but the fluid could also be heated to a fully heated temperature. A muffler (not shown) controls the output of noise during operation of the cleaning apparatus 10 .
[0026] In one embodiment of the present invention, preheating first occurs by the transfer of heat from the hot exhaust gas to the inner wall of inner housing 150 , and then from inner housing 150 to fluid circulating within water jacket 170 . As will be appreciated to a skilled artisan, heat will transfer from the exhaust gases circulating within both Chambers A and B. Also, heat captured by the primary heat exchanger device, or radiator 180 , is also available to transfer to the water jacket 170 , either through contact with portions of internal housing 150 and/or top and bottom covers 120 and 130 . In this way, more heat energy is captured by the present device than could be captured without use of the present sealed system.
[0027] In operation, the temperature of the fluid typically exiting the radiator outlet 186 is increased by approximately 15° to 20° F. at a through rate of five (5) gallons per minute. The temperature increase could be enhanced, including substantially increased, if the amount of fluid passing through the device per unit of time were decreased. Typically, one would desire to have a cleaning fluid exit the cleaning wand at a temperature exceeding 160° F. That temperature can be obtained, if the throughput of fluid is appropriately adjusted, using only the compact heat exchanger 100 . However, to achieve faster throughput it is often desirable to utilize a second, primary heat exchanger 200 .
[0028] Thus, in one preferred embodiment, a second or more heat exchangers 200 is used to further heat the heated fluid exiting the radiator outlet 186 . The second heat exchanger 200 may be of a radiator type, which can but need not be of a tube and fin type, or a coil-type heat exchanger. Because additional temperature increase necessary for operation of the cleaning apparatus 10 at desired temperatures is diminished after preheating of the fluid occurs by use of the compact heat exchanger 100 , the overall fuel consumption of the overall cleaning apparatus 10 is reduced, often considerably.
[0029] The design of the compact heat exchanger 100 , which may preferably have a height of approximately 18 inches and a diameter of approximately 12 inches, preferably efficiently uses organically created super heated exhaust gases from the heat generating unit 30 to preheat the incoming fluid. In particular, the super heated exhaust gases are not only provided to the primary heat exchanger device, or radiator 180 , but also are absorbed by the internal housing 150 . Thus, as will be appreciated by those of skill in the art, only one heat source is needed to preheat the incoming supply of fluid to an initial heightened temperature through the water jacket 170 , through exposure to the super heated exhaust gases provided to the primary heat exchanger device, or radiator 180 . Accordingly, there is no need for other mechanisms, such as diversion of heated water or aggregation of secondary heat sources, to preheat the incoming fluid to a desired and constant temperature, which also contributes to a decreased fuel consumption of the overall cleaning apparatus 10 .
[0030] While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims. Further, the invention(s) described herein is/are capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items as would be understood by those of skill in the art. | The present invention generally relates to a compact heat exchanger for use in a mobile cleaning apparatus. The compact heat exchanger utilizes a water jacket, created by the annular space between a concentrically arranged internal housing and external housing. A radiator is enclosed within the internal housing. As super heated exhaust gas is supplied to the internal housing, heat is transferred to the surface of the internal housing before passing through the radiator. During operation of the mobile cleaning apparatus, incoming fluid, typically water, flows through an inlet and is directed through the water jacket and then the radiator for heating. | 1 |
This application is claiming priority from German patent application serial no. 10 2008040 665.1 filed Jul. 24, 2008.
FIELD OF THE INVENTION
The present invention relates to a method for controlling the oil supply device of an automatic planetary transmission comprising a main oil pump, which is mechanically, drivably connected to the drive shaft of an internal combustion engine, and an auxiliary oil pump that may be driven via a controllable electric motor, both of them being hydraulically connected to a main pressure line, the pressure of which is regulated by means of a main pressure regulating valve, on the pressure side, wherein the automatic transmission is part of a parallel hybrid powertrain of a motor vehicle having an input shaft, which may be connected via a separating clutch to the drive shaft of the internal combustion engine and is permanently drivably connected to the rotor of an electric machine. The invention further relates to an oil supply device of an automatic planetary transmission for using the method according to the invention.
BACKGROUND OF THE INVENTION
The task of an oil supply device of an automatic planetary transmission is to provide a sufficiently high oil volume flow and a sufficiently high operating pressure for actuating the friction shift elements, i.e. the shift clutches and shift brakes, as well as for lubricating and cooling the moving parts of the automatic transmission during the operation of the motor vehicle of interest. For this purpose, an oil supply device usually has at least one oil pump, by means of which hydraulic oil can be delivered from a reservoir (oil pan) to a main pressure line and to a secondary pressure line. The shift control valves, which are primarily integrated into a valve block, are connected to the main pressure line that is under a relatively high working pressure (main pressure P HD ) that can be variably adjusted via a main pressure valve, wherein the shift cylinders of the friction shift elements are pressurized via the shift control valves from the main pressure line in order to engage gears and are discharged into a secondary pressure line or a depressurized line connected to the oil pan via these valves in order to disengage gears. The cooling and lubricating points of the automatic transmission are connected to the secondary pressure line that is under relatively low pressure (secondary pressure p SD ).
The oil pump is usually configured as a so-called fixed displacement pump, which delivers a constant oil volume per revolution of an associated drive element. Known designs of oil pumps of this type include the gear pump, the rotor pump (sickle pump) and the vane pump. The oil pump may be driven mechanically by a drive connection to a driven shaft, such as the drive shaft of the driving motor or the input shaft of the automatic transmission, or electrically by a drive connection to an associated electric motor. The delivery volume flow and the producible working pressure of the oil pump increase with the rotational speed of the driving component (driven shaft or electric motor) and, in the case of the mechanical drive, are determined by the rotational speed of the respective shaft. In contrast, in the case of the electric drive, the delivery volume flow and the producible working pressure are variably controllable within the control range of the associated electric motor. The delivery power drawn from the driving component for driving the oil pump increases with the delivery volume flow and the working pressure at the output side, against which the oil volume flow is pumped into a pressure line.
As a result of the designs perfected in decades of use, the known types of fixed displacement pumps have high functional reliability and long durability. The disadvantage with fixed displacement pumps of this type is, however, that they cannot generate an appreciable oil volume flow and no high working pressure below a minimum input speed, which may result in an undersupply of the automatic transmission with hydraulic oil, in particular when the driving motor is shut off and when the vehicle is stationary. A further disadvantage of known fixed displacement pumps is that, as they have been configured for providing a high delivery rate even at lower input speeds, they deliver an excessively high oil volume flow at higher input speeds, most of which then must be discharged largely unused, resulting in poor transmission efficiency. Different solutions to improve the oil supply of automatic transmissions have therefore been proposed.
A first known solution consists of designing a mechanically driven adjustable oil pump so that the delivery rate thereof may be varied or maintained constant independently of the input speed within an adjustment range that is specified by the design. Such an oil supply device of an automatic planetary transmission having a mechanically driven, adjustable high pressure oil pump has, for example, been described in DE 600 08 588 T2. In this oil supply device, it is provided that the delivery rate of the high pressure oil pump, and thus the working pressure in the connected main pressure line, is regulated by means of a pressure controlled regulating valve, which is actuated by the working pressure of the main pressure line and by the working pressure of a secondary pressure line. For this purpose, it is provided that the working pressure of the main pressure line is conducted into an associated output actuating cylinder via the regulating valve for the inverse control of the delivery rate of the high pressure oil pump. Although an unnecessarily high delivery rate and the resultant reduction of the transmission efficiency is avoided at higher input speeds by the adjustability of the oil pump, the complexity of a device of this type of oil pump and the associated control device is, however, relatively high and may be associated with a high susceptibility to malfunction.
A further known solution of avoiding delivery rate problems consists of arranging and equipping a single oil pump, such that it may be driven mechanically via a drive shaft of the powertrain or via an associated electric motor, as and when needed.
A hybrid drive of a motor vehicle having an oil supply device of this type is known, for example, from DE 199 17 665 A1. In it, an oil pump is provided that is arranged on the drive shaft of an internal combustion engine and may be driven by the drive shaft of the internal combustion engine via the engagement of an associated clutch and by an associated electric motor when the clutch is disengaged. The oil pump may be configured to provide a relatively low delivery rate and, in case of a higher oil requirement, in particular when the internal combustion engine is shut off or running at low rotational speed, may be driven by the electric motor at a higher rotational speed with an open clutch.
A further hybrid drive of a motor vehicle having an oil supply device of this type has been described in DE 101 60 466 C1. In it, an oil pump is provided that is arranged at the input shaft of an automatic transmission and may be mechanically driven by the input shaft of the automatic transmission via a first overrunning clutch and by the rotor of an associated electric motor via a second overrunning clutch. The oil pump is respectively driven via the faster of the two driving elements, so that a sufficiently high delivery rate of the oil pump may be achieved by a corresponding drive via the electric motor, even with a stationary vehicle or at a low driving speed. The disadvantage of an oil pump of this type is the technical complexity and the required space, as well as the susceptibility to malfunction of both alternative drive branches.
Oil supply devices have therefore also been proposed that comprise a main oil pump mechanically drivably connected to a drive shaft of the powertrain, and an auxiliary oil pump that may be driven by a controllable electric motor. A corresponding oil supply device of the automatic transmission of a hybrid powertrain has been described in U.S. Pat. No. 6,692,402 B2. In the associated method for controlling the auxiliary pump, it is provided that the working pressure in a main pressure line is monitored and that the auxiliary oil pump is activated when the working pressure drops below a first limit value due to an insufficient delivery capacity of the main oil pump that is drivably connected to the input shaft of the automatic transmission, in particular due to increased consumption as a result of shifting effects. The auxiliary oil pump is deactivated again when the working pressure increases above a second limit value, in particular after completing a gear change. In order to avoid an excessively high delivery rate of the auxiliary oil pump, and consequently, too high a working pressure, the oil temperature of the hydraulic oil to be delivered is determined, and the driving power of the electric motor is set as a function of the oil temperature, which is to say increased with increasing oil temperature and reduced with decreasing oil temperature.
A further oil supply device having a mechanically drivable main oil pump and an electrically drivable auxiliary oil pump has been known from DE 10 2005 013 137 A1. It is provided therein that the main oil pump, which is drivably connected to the drive shaft of the internal combustion engine, is supported by the auxiliary oil pump such that it at least delivers a sufficient oil volume flow for cooling the start-up element during start-up. The disadvantage of these known oil supply devices and/or control methods is that the main oil pump is only supported and/or supplemented by the operation of the auxiliary oil pump in certain operating states. The basic problems of an insufficient delivery rate of the main oil pump at low input speeds and excessively high delivery rate at high input speeds have, however, not been comprehensively solved in this way.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to propose a method for controlling an oil supply device of an automatic planetary transmission arranged in a parallel hybrid powertrain, the device comprising a mechanically drivable main oil pump and an electrically drivable auxiliary pump, wherein by means of the method delivering oil is the automatic transmission as needed may be achieved, which is to say a sufficiently high oil delivery rate at low input speeds of the main oil pump may be achieved, and an excessively high oil delivery rate at high input speeds of the main oil pump may be avoided.
A further object is to present an oil supply device of an automatic planetary transmission for using the method according to the invention.
The object concerning the control method is attained in conjunction with the characteristics described, in that the current oil requirement P HD — soll of the automatic transmission ATG is determined as a function of at least one currently captured operating parameter, and that the delivery rate P ZP of the auxiliary oil pump ZP is set by a corresponding actuation of the associated electric motor in the combustion and combined driving mode below a minimum input speed (n HP <n HP — min ) of the main oil pump HP, and in the electric driving mode, to at least the total oil requirement (P ZP ≧P HD — soll ) and in the combined driving mode above the minimum input speed (n HP ≧n HP — min ) of the main oil pump HP to at least the residual oil requirement (P ZP ≧ΔP HD =P HD — soll −P HP ) exceeding the delivery rate P HP of the main oil pump HP.
The method according to the invention is consequently based on an oil supply device of an automatic planetary transmission, which comprises a main oil pump HP, which is mechanically, drivably connected in a manner known per se to the drive shaft of the internal combustion engine VM, and an auxiliary oil pump ZP, which may be driven via a controllable electric motor, both oil pumps being hydraulically connected on the pressure side to a main pressure line, the pressure of which is regulated by means of a main pressure valve. The automatic transmission ATG of interest is part of a parallel hybrid powertrain of a motor vehicle, which also comprises an internal combustion engine VM and an electric motor EM. The input shaft of the automatic transmission may be connected to the drive shaft of the internal combustion engine VM via a separating clutch K and is permanently, drivably connected to the rotor of the electric motor EM.
According to the invention, in order to sufficiently supply oil to the automatic transmission during the operation of the hybrid powertrain while at the same time avoid an oversupply that may be detrimental to efficiency, it has been provided that the current oil requirement of the automatic transmission ATG, which is specified by the target delivery rate P HD — soll to be delivered to the main pressure line, is determined as a function of at least one currently captured operating parameter, and that the delivery rate P ZP of the auxiliary pump ZP is set as and when needed by corresponding actuation of the associated electric motor.
As, due to the design thereof, the main oil pump HP has no appreciable delivery rate P HP below the minimum input speed (n HP <n HP — min ) thereof, which is to say it cannot deliver a high volume flow Q HP to the main pressure line and cannot build a high working pressure p HD in the main pressure line, the auxiliary oil pump ZP in the combustion mode, in which only the internal combustion motor VM runs in the traction or trailing throttle mode with an engaged separating clutch K, and in the combined driving mode, in which the internal combustion engine VM runs with an engafed separating clutch K in the traction or trailing throttle mode and in which the electric motor EM is operated as a motor or generator, below the minimum input speed (n HP <n HP — min ) of the main oil pump HP, is set to at least the total oil requirement (P ZP ≧P HD — soll ) of the automatic transmission ATG, which is substantially determined by the sum of the torque M VM output of the internal combustion engine in the traction mode or absorbed in the trailing throttle mode, and the torque M EM output of the electric machine EM in motor mode, or absorbed in generator mode.
Independent of the input speed n HP of the main oil pump HP, this also applies to the electric driving mode, in which only the electric machine EM is operated as a motor or generator, and the internal combustion engine VM is shut off by disengaging separating clutch K, the total oil requirement (P HD — soll ) of the automatic transmission ATG in this case being only determined by the torque M EM output by the electric machine EM in motor mode or absorbed in generator mode.
In contrast, above the minimum input speed (n HP ≧n HP — min ), the main oil pump HP has a delivery rate P HP that is at least sufficient for the combustion driving mode. It is therefore at least provided in the combined driving mode above the minimum input speed (n HP ≧n HP — min ) of the main oil pump HP that the delivery rate P ZP of the auxiliary oil pump ZP is at least set to the previous oil requirement (P ZP ≧ΔP HD =P HD — soll −P HP ) exceeding the delivery rate P HP of the main oil pump HP, whereby a possible undersupply due to the torque M EM additionally output or absorbed by the electric machine EM is avoided.
The main oil pump may therefore be configured such that with relatively low power, and with regard to the delivery rate thereof and be limited to covering the oil requirement based on the output or absorbed torque of the internal combustion engine above the minimum input speed.
Compared to the known oil supply devices and methods for controlling them, the control method according to the invention has the advantage that the main oil pump can be designed to operate with lower power because the delivery shortcoming below the minimum input speed, as well as a possible undersupply, in particular in the combined driving mode above the minimum input speed, are balanced and/or compensated for by a corresponding actuation of the auxiliary oil pump via the delivery rate thereof.
The target delivery rate P ZP — soll of the auxiliary oil pump ZP, which is the basis for the delivery rate P ZP actually set at the auxiliary oil pump ZP and/or at the associated electric motor, is advantageously determined in the combustion and combined driving mode below the minimum input speed (n HP <n HP — min ) of the main oil pump HP, and in the electric driving mode as a function of the target working pressure P HD — soll , which is set via a main pressure valve in the main pressure line, and of the total target oil volume flow Q HD — soll to be delivered to the main pressure line (P ZP — soll =f(P HD — soll , Q HD — soll )).
In contrast, the target delivery rate P ZP — soll of the additional oil pump ZP at least in the combined driving mode above the minimum input speed (n HP ≧n HP — min ) of the main oil pump HP is determined as a function of the target working pressure P HD — soll , which is set in the main pressure line via the main pressure valve and of the residual volume flow (Q ZP — soll =ΔQ HD =Q HD — soll −Q HP ) exceeding the oil volume flow Q HP currently delivered by the main oil pump HP (P ZP — soll =f(P HD — soll , ΔQ HD )).
As the oil requirement P HD — soll of the automatic transmission ATG, which is to say the target working pressure p HD — soll to be set in the main pressure line and the target oil volume flow Q HD — soll to be delivered to the main pressure line, outside of gear changes is substantially used to keep the friction shift elements of the automatic transmission ATG, which were engaged in the currently engaged gear, engaged in a non-slip manner during the transmission of the current torque M GE , and to compensate for the leakage losses occurring at this pressure level, the torque M GE currently transmitted via the input shaft of the automatic transmission is determined as a key operating parameter for determining the current oil requirement P HD — soll , and the oil requirement P HD — soll of the automatic transmission ATG is determined proportionally to the value of the momentarily transmitted torque M GE (P HD — soll ˜|M GE |), which is to say the oil requirement P HD — soll is increased in keeping with the torque M GE increasing in value and reduced in keeping with the torque M GE decreasing in value (P HD — soll ˜|M GE |).
As an exact determination of a torque M GE that is small in value as well as the setting of a small delivery rate P ZP to the auxiliary oil pump ZP are relatively difficult and complex from a control engineering point of view, the oil requirement P HD — soll of the automatic transmission ATG is advantageously limited, for example by specifying a minimum value p HD — min of the target working pressure p HD — soll to be set in the main pressure line and/or a minimum value Q HD — min of the target oil volume flow Q HD — soll to be delivered to the main pressure line, downward to a minimum oil requirement P HD — min . This also means that the target delivery rate P ZP — soll of the auxiliary oil pump ZP is likewise limited downward to a minimum delivery rate P ZP — min when the auxiliary oil pump ZP is operating.
The minimum oil requirement P HD — min of the automatic transmission ATG is advantageously calculated such that the engaged friction shift elements C 1 , C 2 , C 3 , B 1 , B 2 of the automatic transmission ATG remain fully engaged when a torque (|M GE |<|M GE — min |) is presently transmitted via the automatic transmission and below a specified minimum torque M GE — min . It is thus achieved that, for example, in so-called glide phases (propulsion with switched-off internal combustion engine) or in the transition from the traction mode to the trailing throttle mode, the friction shift elements of the currently engaged gear remain engaged, and during a subsequent increase in the transmitted torque M GE need not be again completely engaged from the trailing throttle mode due to a resultant increase in the working pressure p HD in the main pressure line.
As the viscosity of the hydraulic oil, and consequently the leakage losses in the oil supply device, vary relatively strongly with the oil temperature T Öl of the hydraulic oil, the current oil temperature T Öl of the hydraulic oil delivered by the two oil pumps HP, ZP is determined as a further parameter for determining the oil requirement P HD — soll , and the oil requirement P HD — soll is corrected upward if the oil temperature (T Öl >T Ref ) is above a reference temperature T Ref , and downward if the oil temperature (T Ö <T Ref ) is below a reference temperature T Ref .
Because without further measures a gear change would result in a temporary decrease in the working pressure p HD in the main pressure line due to filling the actuating cylinder of at least one friction shift element of a target gear, whereby, for example, another friction shift element remaining engaged during the gear change could temporarily slip, it is preferably provided that the oil requirement P HD — soll of the automatic transmission ATG, and consequently the delivery rate P ZP of the auxiliary oil pump ZP, is increased at the beginning of a gear change and again reduced after completing the gear change. As a result of the temporary increase in the oil requirement P DH — soll , and consequently the delivery rate P ZP of the auxiliary oil pump ZP, the oil volume flow Q HD delivered to the main pressure line is increased while maintaining the working pressure p HD , or if the working pressure p HD is increased, the oil volume flow Q HD delivered to the main pressure line is at least kept constant, so that the volume extracted as a result of the filling of the friction shift element is compensated for by the main pressure valve, and a pressure drop in the main pressure line may be avoided.
As an increase in the oil requirement P HD — soll and/or in the delivery rate P ZP of the auxiliary oil pump ZP at the beginning of a gear change requires a quick response, it is advantageous if driving states are derived from at least one captured operating parameter, which anticipate an impending gear change, and that, if an impending gear change is detected, the oil requirement P HD — soll of the automatic transmission ATG is increased prior to beginning the gear change. An associated increase in the delivery rate P ZP of the auxiliary oil pump ZP may then be carried out more slowly, which is to say with a smaller gradient, and consequently with less dynamic stress for the components of the pressure supply device.
With an engaged gear and at a driving speed (v F ≧v min ) above a determined minimum speed v min , the position of the accelerator pedal and/or a change in the position of the accelerator pedal may, for example, be captured, and an increase in the position of the accelerator pedal above a determined limit gradient may be interpreted as a driving state with an impending upshift or downshift, which triggers a corresponding increase in the oil requirement P HD — soll and in the delivery rate P ZP of the auxiliary oil pump ZP.
Likewise, the position of the accelerator pedal and/or position of the brake pedal or the brake pedal pressure may be captured with an engaged start-up gear and at a driving speed (v F <v min ) below a specified minimum speed v min , and a release of the accelerator pedal and/or actuation of the brake pedal may be interpreted as an impending gear change for reversing the driving direction (changing from the drive position D to R or vice-versa) and trigger a corresponding increase in the oil requirement P HD — soll , as well as in the delivery rate P ZP of the auxiliary pump ZP.
Furthermore, the position of the brake pedal may be captured with a stationary vehicle (v F =0) and engaged parking lock, and an actuation of the brake pedal in this situation may be interpreted as a driving state with an impending gear change to release the parking lock and engage a start-up gear. Because in order to release the parking lock, an actuating cylinder that is provided for disengaging the locking pawl must be pressurized, and in order to engage a start-up gear the actuating cylinders of at least two friction shift elements must be pressurized, an early increase in the oil requirement P DH — soll of the automatic transmission ATG and consequently a corresponding increase in the delivery rate P ZP of the auxiliary oil pump ZP are especially useful.
If the gear is not changed as anticipated, which is to say it does not take place within the specified time span Δt shift after increasing the oil requirement P HD — soll , the oil requirement P DH — soll of the automatic transmission ATG should again be reduced in order to avoid an unnecessarily high delivery rate P ZP of the auxiliary pump
However, as strong accelerations and decelerations of a motor vehicle normally also cause considerable changes, in particular an increase in the torque M GE transmitted in the automatic transmission ATG, which require a rapid adjustment of the oil requirement P DH — soll and, if necessary, of the delivery rate P ZP of the auxiliary pump ZP, it is likewise advantageously provided that driving states are derived from at least one captured operating parameter that anticipate an impending strong acceleration or deceleration of the motor vehicle, and that, when an impending strong acceleration or deceleration is detected, the oil requirement P HD — soll of the automatic transmission ATG is increased even before the acceleration or deceleration is increased.
In this way, with an engaged gear and at a driving speed (v F ≧v min ) above a specified minimum speed v min , the position of the accelerator pedal and the position of the brake pedal may be detected, and a release of the accelerator pedal and/or actuation of the brake pedal may be interpreted as an impending change of the drive condition from the traction mode to the trailing throttle mode, which triggers a corresponding increase in the oil requirement P HD — soll and in the delivery rate P ZP of the auxiliary oil pump ZP.
With an engaged forward gear and at a driving speed (v F <v min ) below a specified minimum speed v min , the position of the accelerator pedal and the change in the position of the accelerator pedal may likewise be detected, and an increase in the position of the accelerator pedal above a specified limit position and/or increase above a specified limit gradient may be interpreted as a driving state with an impending start-up process and trigger a corresponding increase in the oil requirement P HD — soll and in the delivery rate P ZP of the auxiliary oil pump ZP.
If, however, the anticipated acceleration or deceleration of the motor vehicle has not taken place in the specified time span Δt acc after the increase in the oil requirement P HD — soll , the oil requirement P HD — soll of the automatic transmission ATG should again be reduced to the initial value.
When the auxiliary oil pump is operating, which is to say below the minimum input speed (n HP <n HP — min ) of the main oil pump HP in the combustion and combined driving mode, above the minimum input speed (n HP ≧n HP — min ) of the main oil pump HP in the electric driving mode and at least in the combined driving mode, the delivery rate P ZP of the main oil pump is advantageously set to a value, which is above the target delivery rate P ZP — soll required for covering the current oil requirement P HD — soll of the automatic transmission ATG by at least a specified additional rate amount ΔP ZP (P ZP ≧P ZP — zoll +ΔP ZP ). As a consequence of the increase in the delivery rate P ZP of the auxiliary oil pump, uncertainties in the exact determination of the oil requirement P HD — soll as well as a wear-related increase in leakage are taken into account and/or compensated for. In addition, the main pressure valve, via which the working pressure P HD is regulated in the main pressure line, is consequently not completely engaged, but may operate within the regulating range thereof and derive a sufficient oil volume flow to the secondary pressure line for the supply to the cooling and lubrication points of the automatic transmission ATG.
As a result of the good controllability of the auxiliary pump ZP and/or of the associated electric motor, the delivery rate P ZP of the auxiliary oil pump ZP may in each case be continuously adjusted to the currently required target delivery rate P ZP — soll (P ZP ˜P ZP — soll ). This, however, requires permanent regulation of the delivery rate P ZP of the auxiliary oil pump ZP and/or of the rotational speed and torque of the electric motor.
In order to simplify the control of the auxiliary oil pump ZP, it may therefore also be provided that the delivery rate P ZP of the auxiliary oil pump ZP is adjusted to the current target delivery rate P ZP — soll at specified discrete flow levels P Li , wherein a flow level P Li that is greater than or equal to the currently required target delivery rate P ZP — soll is set by the electric machine of the auxiliary oil pump ZP (P ZP =P Li ≧P ZP — soll ).
For an optimal use of the control method according to the invention, the main oil pump HP is preferably configured to cover the oil requirement (P HP =P HD — VM ) resulting from the output or absorbed torque |M VM | of the internal combustion engine VM above the minimum input speed (n HP >n HP — min ). For this purpose, the auxiliary oil pump ZP and the associated electric motor are preferably configured to cover the oil requirement (P ZP =P HD — EM ) resulting from the output or absorbed torque |M EM | of the electric machine EM in the electric driving mode, and to cover the total oil requirement (P ZP =P HD — soll ) below the minimum input speed (n HP <n HP — min ) of the main oil pump HP as well as the residual oil requirement (P ZP =ΔP HD =P HD — soll −P HP ) exceeding the delivery rate P HP of the main oil pump HP above the minimum input speed (n HP ≧n HP — min ) of the main oil pump HP in the combined driving mode.
The auxiliary pump ZP and the associated electric motor may be arranged inside the transmission housing of the automatic transmission ATG, which is to say completely integrated in the automatic transmission ATG.
It is, however, also possible to arrange the auxiliary output pump ZP and the associated electric motor outside the transmission housing of the automatic transmission ATG, and, for example, to be attached outside the transmission housing or to the vehicle body. Although this requires additional installation space, it has the advantage of good accessibility for maintenance and repair works.
BRIEF DESCRIPTION OF THE DRAWINGS
A drawing of an exemplary embodiment is attached to the description for explanation of the present invention. The drawing shows
FIG. 1 the determination according to the invention of the delivery rate of an electric auxiliary oil pump in the electric driving mode of a hybrid powertrain based on a torque/rotational speed diagram of an electric machine.
FIG. 2 a shift-dependent increase in the delivery rate of an electric auxiliary oil pump in the electric driving mode of the hybrid powertrain based on the torque/rotational speed diagram according to FIG. 1 .
FIG. 3 the configuration of a typical hybrid powertrain for using the method according to the invention, and
FIG. 4 the configuration of an oil supply device of an automatic transmission disposed in a hybrid powertrain according to FIG. 3 for using the method according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A parallel hybrid powertrain 1 of a motor vehicle according to FIG. 3 comprises an internal combustion engine VM having a drive shaft 2 , an electric machine EM with a stator 3 and a rotor 4 , and an automatic planetary transmission ATG with an input shaft 5 and an output shaft 6 . The input shaft 5 of the automatic transmission ATG may be connected to the drive shaft 2 of the internal combustion engine VM via a separating clutch K and an input-side torsional vibration damper 7 and is permanently drivably connected to the rotor 4 of the electric machine EM.
The automatic transmission ATG, which, by way of example, in this case corresponds to the known multistage transmission 6HP26 from the product portfolio of ZF Friedrichshafen AG, comprises an input-side transmission structure 8 and an output-side transmission structure 9 , which are arranged between the input shaft 5 and the output shaft 6 and may be shifted by selectively engaging three shifting clutches C 1 , C 2 , C 3 and two shifting brakes B 1 , B 2 .
The input-side transmission structure 8 is configured as a simple planetary gear set 10 with a sun gear 11 , which is permanently fixed with respect to a transmission housing 15 , with a group of planetary gears 12 , which are engaged for gearing with the sun gear 11 and supported rotatably on a common planet carrier 13 , and with a ring gear 14 , which meshes with the planetary gears 12 and is permanently non-rotatably connected to the input shaft 5 .
The output-side transmission structure 9 is configured as a Ravigneaux gear set 16 with a first, radially smaller sun gear 17 , which meshes with a first group of axially short planetary gears 18 , and with a second, radially larger sun gear 19 , which meshes with a second group of axially long planetary gears 20 , which are each engaged for gearing with one of the axially short planetary gears 18 , with a planet carrier 21 , on which the axially short planetary gears 18 and the axially long planetary gears 20 are rotatably supported, and with a ring gear 22 , which meshes with the axially long planetary gears 20 and is permanently non-rotatably connected to the output shaft 6 .
The radially smaller sun gear 17 may be selectively connected to the planet carrier 13 of the input-side transmission structure 8 by means of the first shifting clutch C 1 . The radially larger sun gear 19 may be selectively connected to the planet carrier 13 of the input-side transmission structure 7 by means of the second shifting clutch C 2 . The planet carrier 21 may be selectively connected to the input shaft 5 by means of the third shifting clutch C 3 . The radially larger sun gear 19 may be selectively locked with respect to the transmission housing 15 by means of the first shifting brake B 1 . The planet carrier 21 may be selectively fixed with respect to the transmission housing 15 by means of the second shifting brake B 2 . This known automatic transmission ATG thus has six forward gears G 1 to G 6 and one reverse gear R, which may each be implemented by engaging two of the total of five friction shift elements C 1 , C 2 , C 3 , B 1 , B 2 .
An oil supply device 24 of the automatic transmission ATG shown in more detail in FIG. 4 has a main oil pump HP, which is mechanically drivably connected to the drive shaft 2 of the internal combustion engine VM, and an auxiliary pump ZP, which may be driven via a controllable electric motor 23 . Hydraulic oil may be delivered by means of the main oil pump HP from a reservoir 25 (oil pan) via a suction line 26 and a pressure line 28 provided with a check valve 27 to a main pressure line 29 , the delivery volume flow Q HP increasing proportionally to the rotational speed n VM of the internal combustion engine VM. By correspondingly actuating the electric motor 23 , it is additionally possible to deliver hydraulic oil, as and when needed, in a parallel branch from the reservoir 25 via an associated suction line 30 and a pressure line 32 , which is provided with a check valve 31 , to the main pressure line 29 by means of the auxiliary pump ZP independently of the rotational speed, which is to say independently of the rotational speed n VM of the internal combustion engine VM or the rotational speed of other drive shafts 5 , 6 of the hybrid powertrain 1 .
The relatively high working pressure P HD prevailing in the main pressure line 29 may be regulated via the main pressure valve 33 , which in the present example is configured as a 2/2-way magnetic regulating valve, via which the excess hydraulic oil is conducted to a secondary pressure line 34 . A pressure accumulator 35 is connected to the main pressure line 29 in order to compensate for pressure fluctuations. A pressure limiting valve 36 is additionally arranged between the main pressure line 29 and the secondary pressure line 34 in order to protect the control valves of the friction shift elements C 1 , C 2 , C 3 , B 1 , B 2 connected to the main pressure line 29 from overload. A further pressure limiting valve 37 is arranged between the secondary pressure line 34 and the depressurized oil pan 25 in order to protect the cooling and lubrication points of the automatic transmission ATG connected at a relatively low working pressures p SD to the secondary pressure line 34 .
In order to control the working pressure p HD prevailing in the main pressure line 29 and the delivery rate P ZP of the auxiliary oil pump ZP as needed, a control device 38 is provided, which is connected to a pressure sensor 40 connected, via a sensor line 39 , to the main pressure line 29 , and via associated control lines 41 , 42 , is connected to the main pressure valve 33 and to the electric motor 23 of the auxiliary oil pump ZP. The oil requirement P HD — soll of the automatic transmission ATG, which is to say the working pressure p HD to be set in the main pressure line 29 and the total target oil volume flow Q HD — soll to be delivered to the main pressure line 29 , is substantially determined by the torque M GE presently transmitted via the automatic transmission ATG and/or the input shaft 5 thereof. The portion of the delivery rate P HD — soll that has to be generated by the auxiliary oil pump ZP depends on the current operating mode of the hybrid powertrain 1 and the current delivery rate P HD of the main oil pump HP.
The diagram of FIG. 1 by way of example shows the connection between the transmitted torque M GE and the delivery rate P ZP of the auxiliary oil pump ZP for the electric driving mode of the hybrid powertrain 1 , in which the internal combustion engine VM is shut off with a disengaged separating clutch K and the main oil pump HP is consequently deactivated. The interrupted course of the curve reflects the connection between the torque M EM of the electric machine EM and the rotational speed n EM of the electric machine EM and/or the rotational speed n GE of the input shaft 5 of the automatic transmission ATG connected to the rotor 4 of the electric machine EM for the full load operation of the electric machine EM.
If the motor vehicle of interest is started up in the electric driving mode, which is to say only with the driving torque M EM of the electric machine EM, under full load, the oil requirement P HD — soll of the automatic transmission ATG is consequently specified by the interrupted curve (with the right scale for P ZP ). As the internal combustion engine VM and the main oil pump HP are shut off in the electric driving mode, the entire oil requirement P HD — soll of the automatic transmission ATG has to be covered by the operation of the auxiliary oil pump ZP, so that the target delivery rate P ZP — soll of the auxiliary oil pump ZP corresponds to the total oil requirement P HD — soll of the automatic transmission ATG.
The target delivery rate P ZP — soll of the auxiliary oil pump ZP, however, advantageously is limited downward by the specification of a minimum delivery rate P ZP — min , since the exact determination of a torque M EM that is small in value as well as the setting of a small delivery rate P ZP at the auxiliary oil pump ZP are relatively difficult and complex from a control engineering point of view. Likewise, the delivery rate P ZP of the auxiliary oil pump ZP is advantageously not set exactly to the determined value of the target delivery rate P ZP — soll , but set to a value which by at least a specified added rate amount ΔP ZP exceeds the target delivery rate P ZP — soll required to cover the current oil requirement P HD — soll of the automatic transmission ATG (P ZP >P ZP — soll +ΔP ZP ).
The added rate amount ΔP ZP is a control reserve, by means of which uncertainties in the exact determination of the oil requirement P HD — soll as well as a wear-induced increase in leakage are taken into account and/or compensated for. The dot-dash curve in FIG. 1 shows a continuous adaptation of the delivery rate P ZP (P ZP =P ZP — soll +ΔP ZP ), at which it is reduced in keeping with the torque M EM decreasing with increasing rotational speed n GE .
In order to simplify the control of the auxiliary oil pump ZP, it may therefore also be provided that adaptation of the delivery rate P ZP of the auxiliary oil pump ZP to the target delivery rate P ZP — soll also takes place at specified discrete rate levels P Li (P L1 to P L6 ), wherein a rate level P Li , which is greater than or equal to the currently required target delivery rate P ZP — soll plus the capacity reserve ΔP ZP (P ZP= P Li ≧P ZP — soll +ΔP ZP ), is respectively set at the electric machine of the auxiliary oil pump ZP. The gradual adaptation of the delivery rate P ZP of the auxiliary oil pump ZP is shown in FIG. 1 by the uninterrupted step-shaped curve.
If an upshift is performed during start-up in order to increase the accelerating power, the delivery rate P ZP of the auxiliary oil pump ZP is increased to cover the increased requirement induced by the pressurization of at least one friction shift element (C 1 , C 2 , C 3 , B 1 , B 2 ) at the latest as the shifting rotational speed n s , which is to say when shifting is started, is reached, and is again decreased at the earliest when the target rotational speed n z is reached, which is to say when shifting is completed. This procedure is shown in the diagram of FIG. 2 with the dot-dashed course of the curve marked with directional arrows for a continuous adaptation of the delivery rate P ZP of the auxiliary pump ZP, and the uninterrupted course of the curve marked with directional arrows for a gradual adaptation of the delivery rate P ZP of the auxiliary oil pump ZP.
REFERENCE NUMERALS
1 parallel hybrid powertrain
2 drive shaft
3 stator
4 rotor
5 input shaft
6 output shaft
7 torsional vibration damper
8 input-side transmission structure
9 output-side transmission structure
10 planetary gear set
11 sun gear
12 planetary gear
13 planet carrier
14 ring gear
15 transmission housing
16 Ravigneaux gear set
17 sun gear
18 planetary gear
19 sun gear
20 planetary gear
21 planet carrier
22 ring gear
23 electric motor
24 pressure supply device
25 reservoir, oil pan
26 suction line
27 check valve
28 pressure line
29 main pressure line
30 suction line
31 check valve
32 pressure line
33 main pressure valve
34 secondary pressure line
35 pressure reservoir
36 pressure limiting valve
37 pressure limiting valve
38 control device
39 sensorline
40 pressure sensor
41 control line
42 control line
ATG automatic planetary transmission
B 1 shifting brake, friction shift element of ATG
B 2 shifting brake, friction shift element of ATG
C 1 shifting clutch, friction shift element of ATG
C 2 shifting clutch, friction shift element of ATG
C 3 shifting clutch, friction shift element of ATG
D drive position ATG
EM electric machine
G 1 -G 6 forward gear of ATG
HP main oil pump
K separating clutch
M torque
M EM torque of EM
M GE transmitted torque at the input shaft of ATG
M GE — min minimum torque at the input shaft of ATG
M VM torque of VM
n rotational speed
n GE rotational speed of the input shaft
n HP input speed of HP
n HP — min minimum input speed of HP
p pressure
p HD working pressure in the main pressure line, main pressure
p HD — min minimum working pressure in the main pressure line
p HD — soll target working pressure in the main pressure line, target main pressure
p SD working pressure in the secondary pressure line, secondary pressure
P flow rate
P HD — min minimum oil requirement in the main pressure line
P HD — soll oil requirement of ATG, target delivery rate in the main pressure line
P HP delivery rate of HP
P Li discrete rate level of ZP
P L1 -P L6 discrete rate level of ZP
P ZP delivery rate of ZP
P ZP — min minimum delivery rate of ZP
P ZP — soll target delivery rate of ZP
Q HD volume flow delivered to the main pressure line
Q HD — min minimum oil volume flow delivered to the main pressure line
Q HD — soll target oil volume flow delivered to the main pressure line
Q HP volume flow delivered by HP
R drive position, reverse gear of ATG
T Öl oil temperature
T Ref reference temperature
v F driving speed
v min minimum speed
VM internal combustion engine
ZP auxiliary oil pump
ΔP HD residual oil requirement in the main oil line
ΔP ZP added rate amount of ZP
ΔQ HD residual oil volume flow in the main pressure line
Δt acc time span for acceleration or deceleration
Δt shift time span for gear change | A method for controlling the oil supply device of an automatic planetary transmission, having a main oil pump and an auxiliary oil pump. The transmission is part of a parallel hybrid vehicle powertrain. To supply oil to the transmission as needed, the current oil requirement of the transmission is determined depending on at least one current operating parameter. The auxiliary pump delivery rate is set by actuating the electric motor, in the combustion and combined driving mode below a minimum main oil pump input speed and in the electric driving mode to at least the total oil requirement, and at least in the combined driving mode above the minimum main oil pump input speed is set to at least the residual oil requirement exceeding the delivery rate of the main oil pump. | 5 |
TECHNICAL FIELD
[0001] The present invention relates to a refrigeration apparatus, employing a chlorine atom-free and carbon-carbon double bond-containing hydrofluoroolefin as its refrigerant, that contains a refrigeration oil enclosed therein and is equipped with a compressor, a condenser, an expansion mechanism and an evaporator.
BACKGROUND ART
[0002] Conventionally, hydrocarbon fluorides (HFCs) containing fluorine and hydrogen atoms have been used as refrigerants of air conditioners, car air conditioners and others. In addition, polar refrigeration oils such as polyalkylene glycol (PAG)s, polyol ester (POE)s and polyvinylether (PVE)s have been used in refrigeration cycles employing these HFCs as refrigerants, from the viewpoint of compatibility with the refrigerants. In such a refrigeration cycle, fluorine ions are often generated from the materials such as fluorine resins used therein. It is known that the ester-based refrigeration oil is then decomposed by the fluorine ions extracted into the refrigeration oil, resulting in corrosion of the metal sliding materials by the acid components and deterioration of the motor insulation paper. Thus in Patent Document 1, the amount of fluorine ions extracted from the fluorine resins was limited to a concentration of 1 ppm or less in the refrigeration oil, for example by previous heat treatment of the resins.
CITATION LIST
[0003] Patent Document 1:JP-A No.2004-204679
SUMMARY OF INVENTION
Technical Problem
[0004] However, it was not possible in such conventional configurations to prevent generation of hydrogen fluoride by decomposition in reaction of the refrigerant hydrofluoroolefin with oxygen remaining in the refrigeration cycle in the regions at high temperature such as a sliding part in a compressor, and the materials used in the refrigeration cycle are often degraded.
[0005] An object of the present invention, which was made to solve the problems above, is to provide a refrigeration apparatus employing a hydrofluoroolefin-containing refrigerant and a refrigeration oil as working fluids that can be operated reliably for an extended period of time, as hydrogen fluoride is removed by reaction and deterioration of the components used in the refrigeration cycle is suppressed.
Solution to Problem
[0006] The refrigeration apparatus of the present invention, which solved the traditional problems above, employs an ester-based refrigeration oil containing an unsaturated fatty acid as constituent fatty acid, and a single refrigerant of carbon-carbon double bond hydrofluoroolefin or a mixed refrigerant containing the hydrofluoroolefin as primary component and a hydrofluorocarbon having no double bond is enclosed therein.
[0007] Hydrogen fluoride, a decomposition product of the refrigerant, in the system is removed through the reaction with the unsaturated fatty acid residues in the refrigeration oil. Although the unsaturated fatty acid residues give hydrogen fluoride adducts in reaction with hydrogen fluoride, the adducts may be circulated in the system consistently as the refrigeration oil.
Advantageous Effects of Invention
[0008] In the refrigeration apparatus according to the present invention, hydrogen fluoride generated in the refrigeration apparatus is removed from the system in reaction with unsaturated bonds in an ester-based refrigeration oil containing an unsaturated fatty acid as constituent fatty acid and thus, degradation of the components used in the refrigeration cycle is suppressed.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a chart showing the cycle of the refrigeration apparatus in embodiment 1 of the present invention.
[0010] FIG. 2 is a table showing the relationship between the global warming potential and the mixing ratio of the two-component mixed refrigerants.
DESCRIPTION OF EMBODIMENTS
[0011] The invention of the refrigeration apparatus according to claim 1 , comprises an ester-based refrigeration oil containing an unsaturated fatty acid as a constituent fatty acid, and a refrigeration cycle having a refrigerant circulation route extending from a compressor, via a condenser, an expansion mechanism and a evaporator, back to the compressor, wherein a refrigerant comprising a single refrigerant of hydrofluoroolefin having a carbon-carbon double bond or a mixed refrigerant containing the hydrofluoroolefin as primary component and a hydrofluorocarbon having no double bond is enclosed into the refrigeration cycle, thereby to prevent degradation of the components used in the refrigeration cycle, because hydrogen fluoride generated in the refrigeration cycle by decomposition of the refrigerant is stabilized, as it is incorporated into the refrigeration oil in reaction with the refrigeration oil.
[0012] The “primary component”, as used here in the present invention, is at least one component essentially used in the refrigerant of the present invention. The primary component is not necessarily a component highest in component rate.
[0013] According to the invention of the refrigeration apparatus of claim 2 , the ester-based refrigeration oil containing an unsaturated fatty acid as a constituent fatty acid enclosed in the refrigeration apparatus of claim 1 has both a saturated fatty acid and an unsaturated fatty acid as constituent fatty acids in one molecule, thereby the ester-based refrigeration oil containing a fatty acid residue reactive with hydrogen fluoride generated by decomposition of the refrigerant and also a fatty acid residue non-reactive therewith in one ester oil molecule. Thus, the ester oil after reaction with hydrogen fluoride retains its physical properties without significant change and functions as a refrigeration oil, thereby inhibiting degradation of the components used in the refrigeration cycle.
[0014] According to the invention of the refrigeration apparatus of claim 3 , the unsaturated fatty acid residue in the ester-based refrigeration oil containing an unsaturated fatty acid as constituent fatty acid that is enclosed in the refrigeration apparatus according to claim 1 does not contain two or more carbon-carbon unsaturated bonds per one unsaturated fatty acid residue, the refrigeration apparatus can prevent polymerization reaction between the unsaturated bonds and thus remove hydrogen fluoride efficiently in reaction therewith. It is thus possible to prevent degradation of the components used in the refrigeration cycle.
[0015] According to the invention of the refrigeration apparatus of claim 4 , the unsaturated fatty acid residue of the ester-based refrigeration oil containing an unsaturated fatty acid as constituent fatty acid that is enclosed in the refrigeration apparatus according to claim 1 is a branched-chain fatty acid, the ester bond portion is easily surrounded by neighboring substituent groups. Thus, the ester-based refrigeration oil itself is resistant to hydrolytic reaction, possibly suppressing generation of organic acids and degradation of the components used in the refrigeration cycle.
[0016] According to the invention of the refrigeration apparatus of claim 5 , the ester-based refrigeration oil containing an unsaturated fatty acid as constituent fatty acid that is enclosed in the refrigeration apparatus according to claim 1 is miscible with the refrigerant, and thus hydrogen fluoride generated by decomposition of the refrigerant can be trapped more efficiently, suppressing degradation of the components used in the refrigeration cycle.
[0017] According to the invention of the refrigeration apparatus of claim 6 , the refrigerant enclosed in the refrigeration apparatus of claim 1 is a two- or three-component mixed refrigerant adjusted to have a global warming potential of not more than 750, it is possible to minimize the adverse effects on global warming, even if the unrecovered refrigerant is discharged into air.
[0018] Hereinafter, favorable embodiments of the present invention will be described with reference to drawings, but it should be understood that the present invention is not restricted by these embodiments.
Embodiment 1
[0019] FIG. 1 is a chart showing the cycle of the refrigeration apparatus in embodiment 1 of the present invention. As shown in FIG. 1 , the refrigeration apparatus has a compressor 1 for compressing the refrigerant, a condenser 2 for condensing the refrigerant, an expansion mechanism 3 , such as of expansion valve, for expanding the refrigerant, and an evaporator 4 for vaporization of the refrigerant, and additionally tubing 5 and a four-way valve 6 connecting the units to each other and an accumulator (not shown in the Figure), and contains a refrigerant and a refrigeration oil as working fluids.
[0020] The refrigerant enclosed in the refrigeration apparatus is a two- or three-component mixed refrigerant containing a hydrofluoroolefin, such as tetrafluoropropene (HFO1234yf) as primary component and difluoromethane (HFC32) or/and pentafluoroethane (HFC125), which are added to make the global warming potential (GWP) of the refrigerant 5 or more and 750 or less, desirably 5 or more and 300 or less. It may be a single hydrofluoroolefin refrigerant (GWP=4).
[0021] FIG. 2 is a table showing the relationship between the global warming potential and the mixing ratio of the two-component refrigerants of tetrafluoropropene mixed with difluoromethane or pentafluoroethane. Specifically as shown in FIG. 2 , in the case of a two-component mixture, difluoromethane should be mixed in an amount of 44 wt % or less to make the GWP not larger than 300 when tetrafluoropropene and difluoromethane are mixed, pentafluoroethane should be used in an amount of 21.3 wt % or less to make the GWP not larger than 750 when tetrafluoropropene and pentafluoroethane are used, and pentafluoroethane should be used in an amount of 8.4 wt or less to make the GWP not larger than 300.
[0022] When the refrigerant is a single refrigerant of tetrafluoropropene, it has an extremely favorable GWP of 4. However, as it has a specific volume larger than that of refrigerants mixed with a hydrofluorocarbon, it has smaller refrigeration capacity and thus, demands a larger refrigeration apparatus. In other words, it is possible, by using a refrigerant in combination of a hydrofluoroolefin having a carbon-carbon double bond as primary component and a hydrofluorocarbon having no double bond, to improve particular properties such as refrigeration capacity, compared to single hydrofluoroolefin refrigerants, and make it more easily usable. Thus, in the enclosed refrigerant, the ratio of tetrafluoropropene in the case of mixed refrigerant, or even in the case of using tetrafluoropropene as single refrigerant, may be selected properly according to the purpose of the refrigeration apparatus or the like in which a compressor is installed and the conditions such as the restriction of GWP described above.
[0023] It is thus possible to minimize the adverse influence of the unrecovered refrigerant on global warming, even if it is released into air. In addition, the mixed refrigerant mixed at the rate above can make the temperature difference smaller, even though it is a non-azeotropic mixture refrigerant, and shows the behavior similar to that of pseudo-azeotropic mixture refrigerants, and thus, can improve the performance of the refrigeration apparatus and the coefficient of performance (COP).
[0024] Furthermore, the refrigeration oil enclosed in the compressor 1 , which is miscible with the refrigerant, contains an ester-based refrigeration oil containing an unsaturated fatty acid as its constituent fatty acid. Typical examples of the unsaturated fatty acid-containing ester-based refrigeration oils include ester oils containing a saturated fatty acid and an unsaturated fatty acid as constituent fatty acids in one molecule and mixtures of an ester oil containing a saturated fatty acid as constituent fatty acid and an ester oil having an unsaturated fatty acid as at least one constituent fatty acid in one molecule.
[0025] The ester-based refrigeration oil of the present invention is produced in dehydration reaction between a polyvalent alcohol and a saturated or unsaturated fatty acid. A polyvalent alcohol such as neopentylglycol, pentaerythritol or dipentaerythritol is used according to the viscosity of the refrigeration oil. The other saturated fatty acid for use is, for example, a straight-chain fatty acid such as hexanoic acid, heptanoic acid, nonanoic acid or decanoic acid or a branched-chain fatty acid such as 2-methylhexanoic acid, 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid. It should be noted that the straight-chain fatty acid-containing ester oils are superior in sliding properties but inferior in hydrolytic resistance, while the branched-chain fatty acid-containing ester oils are slightly inferior in sliding properties but favorably resistant to hydrolysis.
[0026] In one embodiment of the ester-based refrigeration oil of the present invention, part of the saturated fatty acids, which is fatty acids constituting the ester oil compatible with the above refrigerant, is replaced with an unsaturated fatty acid. Such an ester oil can be produced in dehydration reaction of a mixture of a polyvalent alcohol and saturated and unsaturated fatty acids. The number of the unsaturated bonds in the unsaturated fatty acid is not particularly limited, but presence of two or more unsaturated bonds is unfavorable, because it leads to excessively high reactivity and easy polymerization thereof. Triple bond-containing compounds are mostly highly reactive and thus unfavorable.
[0027] Favorable examples of the unsaturated fatty acids for use in the present invention include unsaturated fatty acid having an unsaturated bond number of 1 such as 2-hexenoic acid, 3-hexenoic acid, 6-heptenoic acid, 10-undecylenoic acid, 2-octenoic acid, 2,2-dimethyl-4-pentenoic acid, 2-ethyl-2-hexenoic acid, citronellic acid and the like.
[0028] Another embodiment of the ester-based refrigeration oil of the present invention is a mixture of an ester oil containing a saturated fatty acid as a constituent fatty acid and an ester oil containing at least one unsaturated fatty acid as its constituent fatty acid in one molecule. In such a case, the content of the unsaturated fatty acid residues in the ester oil can be adjusted arbitrarily.
[0029] The ester oil containing an unsaturated fatty acid as a constituent fatty acid has an action to capture the acid remaining in the refrigeration apparatus and thus to inhibit sludge generation. In addition, the unsaturated bond has an action to coordinate with iron on the sliding face, inhibiting corrosion of iron.
[0030] The refrigeration oil of the present invention may contain, as needed, various additives such as extreme-pressure additives such as triphenyl phosphate and tricresyl phosphate, oiliness improver such as long chain alcohols, antioxidants such as dibutyl para-cresol and naphthylamine, acid scavengers such as epoxy-containing compounds, and antifoams, as properly selected.
[0031] Although the present invention has been described as a refrigeration apparatus mainly for use as an air conditioner for air conditioning, the advantageous effect of the refrigeration apparatus is the same, if it is a non-open-type refrigeration apparatus, and it is needless to say that it is a technology applicable, for example, to freezing refrigerators, freezers, dehumidifiers, heat-pump drying washing machines, heat-pump water heaters, and beverage vending machines.
INDUSTRIAL APPLICABILITY
[0032] The refrigeration apparatus of the present invention, which can remove hydrogen fluoride generated in the refrigeration apparatus from the system in reaction with the unsaturated bonds in the refrigeration oil and suppress degradation of the components used in the refrigeration cycle, can be applicable to air conditioners, car air conditioners, water heaters, freezing refrigerators, freezers, dehumidifiers, heat-pump drying washing machines, heat-pump water heaters, beverage vending machines and others. | Use of a double bond-containing hydrofluoroolefin refrigerant causes a problem that it generates hydrogen fluoride by cleavage and decomposition under influence of oxygen, leading to degradation of the materials and the refrigeration oil used in the refrigeration apparatus and causing troubles in the refrigeration apparatus.
It is possible to provide a high-reliability longer-lasting refrigeration apparatus by inexpensive method, by using a double bond-containing hydrofluoroolefin refrigerant in a refrigerating cycle having a refrigerant circulation route extending from a compressor 1, via a condenser 2, an expansion mechanism 3, and an evaporator 4, back to the compressor 1 that contains an ester-based refrigeration oil containing an unsaturated fatty acid as a constituent fatty acid. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of International Application PCT/JP2011/067554, filed Jul. 29, 2011, which international application was published on Oct. 4, 2012 as international Publication WO 2012/132041. The International Application claims priority of International Patent Application No. PCT/JP2011/058296, filed Mar. 31, 2011, which international application was published on Oct. 4, 2012, as International Publication WO 2012/131998.
TECHNICAL FIELD
[0002] The present invention relates to a mill for milling aggregates etc. and in particular, relates to a mill that can reduce noise and the like.
BACKGROUND
[0003] Conventionally, there have been various kinds of ball mill-type mills as a device for obtaining recycled aggregate from scrap materials of concrete or asphalt. Many of them have dram bodies whose internal portions are divided by several milling plates (divider plates) in order to extend residence time of a to-be-milled material(s). In such mills, the to be milled material are moved from one end to the other end of the drum both through a gap between peripheral edge parts of the milling plates and walls inside the drum body as they are milled by a ball (a milling media) in each divided section.
[0004] This kind of conventional mill was attached such that its milling plate intersected at a right angle to a central shaft, and therefore it made impossible to positively move the ball in a front-back direction (in a shaft length direction of the drum body). As a result, the ball mostly used to move toward a radial direction and a circumferential direction. It therefore caused a ball and a to-be-milled material to rotate at uniform velocity, i.e. so called “an accompanying rotation” phenomenon, leading to significant decrease in mill efficiency.
[0005] In order to solve these problems, the applicant has already proposed a mill that can remarkably improve the mill efficiency by preventing the above-described accompanying rotation phenomenon from generating (see the following patent documents 1 and 2). The inventions described in the patent documents 1 and 2 can positively move a milling media (a ball etc.) in a front and back direction by attaching a milling plate so that it is inclined with respect to the plane intersecting the central shall, at a right angle. So to speak, they added to the milling plate the function of an agitating blade.
[0006] However, the conventional ball-mill type mills including, the mills in the patent documents 1 and 2 had a problem of making a loud noise. After examining, the applicant discovered that the main reason for the loud noise was due to big noise generated by clash between the ball and the to-be-milled material, and the ball and a drum body, especially, the latter.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0007] The present invention is to solve the above-described problems of the conventional art, to be able to remarkably reduce noise during operation, and to contribute to miniaturization of a device.
Means for Solving the Problems
[0008] The mill of the present invention comprises a cylindrical drum body configured so that a to-be-milled material(s) can be taken in through a part of the mill and be discharged from the other part, a central shaft penetrating said drum body in a longitudinal direction, and a plurality of milling plates which are attached with predetermined spacing in a shall direction of said central shaft and divide interior space of said drum body into a plurality of milling chambers, wherein at least any one of said drum body or said milling plates rotates, and wherein the mill does not comprise a milling media which mills said to-be-milled material by contacting said material therewith while moving by rolling in said drum body. “At least any one of said drum body or said milling plate rotates” includes a case where only a drum body rotates but a milling plate remains stationary, a case where only the milling plate rotates but the drum body remains stationary, and a case where both the drum body and the milling plate rotate.
[0009] The mill according to one aspect of the present invention comprises a plurality of pressure-receiving members which are attached to said drum body and face each of said milling plates, respectively, wherein at least any one of said milling plates and said pressure-receiving members rotates. “At least any one of said milling plates and said pressure-receiving members rotates” includes a case where only a milling plate rotates but a pressure-receiving member remains stationary, a case where only the pressure-receiving member rotates but the milling plate remains stationary, and a case where both the milling plate and the pressure-receiving member rotate.
[0010] According to the mill of one aspect of the present invention, at least any one of said milling plate and said pressure-receiving members is inclined with respect to a plane intersecting the central shaft at a right angle.
[0011] According to the mill of one aspect of the present invention, said milling plate is provided with a plurality of through holes which said to-be-milled material can pass through.
[0012] According to the mill of one aspect of the preset invention, said through holes are provided only in the vicinity of said central shaft.
[0013] According to the mill of one aspect of the present invention, said pressure-receiving members are provided with a plurality of through holes which said to-be-milled material can pass through.
[0014] According to the mill of one aspect of the present invention, said milling plates and said pressure-receiving members rotate in a reverse direction with respect to each other.
[0015] According to the mill of one aspect of the present invention, surface of at least any one of said milling plates and said pressure-receiving members has a concave-convex pattern. “Concave-convex pattern” includes a fine concave-convex pattern whose surface is finely roughened and a large concave-convex pattern having relatively large concave and convex portions.
[0016] According to the mill of one aspect of the present invention, said milling plates have wavy curved-surface structures where peaks and valleys are iteratively provided at certain spacing in a circumference direction.
[0017] According to the mill of one aspect of the present invention, a hopper for putting the to-be-milled material into said drum body is provided on a central part of the drum body in a longitudinal direction, a discharge spout for discharging the to-be-milled material from said drum body is provided on both ends of the drum body in a longitudinal direction, said milling plates are attached to be inclined with respect to a plane intersecting said central shaft at a right angle and rotate with said central shaft, and said milling plates at one side and the other side across the said hopper are oppositely inclined with respect to each other.
[0018] According to the mill of one aspect of the present invention, said milling plates are attached to be inclined with respect to a plane intersecting said central shaft at a right angle and rotate with said central shaft, said pressure-receiving members have an inclined plane which is attached on intersect said central shaft at a right angle and is inclined with respect to a plane intersecting said central shaft at a right angle so that a plane facing said milling plates will be substantially circular truncated cone-shaped, and an inclined angle of said inclined plane with respect to the plane intersecting said central shaft at a right angle is substantially equal to an inclined angle of said milling plates with respect to the plane intersecting said central shaft at a right angle.
[0019] According to the mill of one aspect of the present invention, a discharge spout for discharging the to-be-milled material from said drum body is provided with a mechanism for changing discharge spout areas, which can change size of said discharge spout.
[0020] The mill according to one aspect of the present invention comprises at least one sieve member which is attached to said other part of said drum body and sorts the to-be-milled material discharged from said drum body into several grades. According to the mill of one aspect of the present invention, a plurality of conveyor devices for carrying the to-be-milled material sorted by the sieve member for every said grade are placed.
Effects of the Invention
[0021] According to the present invention, the mill has no milling media, such as a ball, which was conventionally placed inside a drum body, and thus no clash between the milling media and the drum body or to-be-milled materials happens. That is, the to-be-milled materials are mutually rubbed and milled. Therefore, the noise made by the clash of a milling media and a drum body, etc. can be eliminated and the total amount of noise can be reduced. Furthermore, the absence of the milling media can decrease a volume of the drum body by the volume occupied by the milling media.
[0022] According to one aspect of the present invention, even if the mill has no milling media, such as a ball, which was conventionally placed inside a drum body, it is possible to efficiently mill the to-be-milled material by rubbing the materials between the milling plate and a pressure-receiving member.
[0023] According to one aspect of the present invention, inclination of at least any one of the milling plate and the pressure-receiving member with respect to the plane intersecting the central shaft at a right angle can easily create narrower rooms for holding the to-be-milled material in between the pressure-receiving member and the milling plate, thereby improving the mill efficiency.
[0024] According to one aspect of the present invention, a plurality of through holes provided on the milling plate for passing the to-be-milled material therethrough allows to keep the mill efficiency high, make the flow of the to-be-milled material smooth, and improve the working efficiency. According to one aspect of the present invention, the through holes of the milling plate provided only in the vicinity of the central shaft increases residence time of the to-be-milled material in each milling chamber and allows to ensure elimination of foreign matters (such as mortar etc.) adhered on surface of the to-be-milled material (scrap materials of concrete etc.), thereby improving quality of the recycled aggregate to be reclaimed.
[0025] According to one aspect of the present invention, a plurality of through holes provided on the pressure-receiving member for passing the to-be-milled material therethrough allows to keep the mill efficiency high, make the flow of the to-be-milled material smooth, and improve the working efficiency.
[0026] According to one aspect of the present invention, rotation of the milling plate and the pressure-receiving member in a reverse direction with respect to each other allows application of high milling force to the to-be-milled material, thereby improving the mill efficiency.
[0027] According to one aspect of the present invention, concave-convex pattern provided on surface of at least any one of the milling plate and the pressure-receiving member increases the number of parts where the to-be-milled material are rubbed hard by the milling plate or the pressure-receiving member, thereby improving the mill efficiency.
[0028] According to one aspect of the present invention, said milling plate has a wavy curved-surface structure where peaks and valleys are iteratively provided at certain spacing in a circumference direction, and as a result, the to-be-milled material can be rubbed hard by the milting plate or the pressure-receiving member, thereby improving the mill efficiency. Moreover, smooth curved surface of the milling plate makes it difficult to easily crush the to-be-milled material.
[0029] According to one aspect of the present invention, since a hopper for putting the to-be-milled materials into the drum body is provided on a central part of the drum body in a longitudinal direction, a discharge spout for discharging the to-be-milled materials from said drum body is provided on both ends of the drum body in a longitudinal direction, the milling plates are attached to be inclined with respect to a plane intersecting said central shaft at a right angle and rotate with said central shaft, and said milling plates at one side and the other side across the said hopper are oppositely inclined with respect to each other, it is possible to transfer the to-be-milled materials taken in from the hopper into the drum body to the right and left side of the drum body, respectively, mill the transferred materials, and then separately discharge the materials from the discharge spout provided on left and right ends of the drum body. Therefore, it is possible to almost double the mill efficiency, compared with the mill for transferring the to-be-milled materials in only one direction, from one end to the other end of the drum body.
[0030] According to one aspect of the present invention, the milling plate is attached to be inclined with respect to the plane intersecting the central shaft at a right angle and rotates with the central shaft, the pressure-receiving member has an inclined plane which is attached to intersect the central shaft at a right angle and is inclined with respect to a plane intersecting the central shaft at a right angle so that a plane facing the milling plate will be substantially circular truncated cone-shaped, an inclined angle of the inclined plane with respect to the plane intersecting the central shaft at a right angle is substantially equal to an inclined angle of the milling plate with respect to the plane intersecting the central shaft at a right angle. As a result, trajectory of rotary motion of the milling plate shows a shape of figure eight, and at this time, the milling plate and an inclined surface of the pressure-receiving member will be facing parallel to each other. This allows the to-be-milled material to be always rubbed between surface of the milling plate and surface of the pressure-receiving member during the rotation of the milling plate, thereby remarkably improving the mill efficiency. In addition, rotation of the milling plate generates wind like a fan, and accordingly, the to-be-milled material can be easily transferred in the drum body.
[0031] According to one aspect of the present invention, a discharge spout for discharging the to-be-milled material from the drum body is provided with as mechanism for changing discharge spout areas, which can change site of the discharge spout. Therefore, the residence time (milling processing time) of the to-be-milled material in the drum body can be easily adjusted.
[0032] According to one aspect of the present invention, placement of a sieve member on the other part of the drum body for discharging the to-be-milled, material allows to continuously carry out a step of sorting the milled to-be-milled material into several grades (sizes) based on purposes and a step of milling, thereby improving efficiency through the step.
[0033] According to one aspect of the present invention, placement of at least one conveyor device for carrying the to-be-milled material sorted by the sieve member allows to place a large container for separately storing the sorted to-be-milled material based on purpose, without interfering the mill.
BRIEF DESCRIPTION OF FIGURES
[0034] FIG. 1 —It is a front and partial sectional view of a mill according to a first embodiment of the present invention.
[0035] FIG. 2 —It shows a pressure-receiving member according to the first embodiment, and (a) is a plan view, (b) is a sectional view taken along lines IIb-IIb.
[0036] FIG. 3 —It shows a milling plate according to the first embodiment, and (a) is a plan view, (b) is a side view, (c) is a sectional view taken along lines IIIc-IIIc, and (d) is a perspective view.
[0037] FIG. 4 —It is a from and partial sectional view of a sieve member and a conveyor device according to the first embodiment.
[0038] FIG. 5 —It is a sectional view showing a first modified example of the pressure-receiving member.
[0039] FIG. 6 —It is sectional view for explaining milling action with the pressure-receiving member and the milling plate.
[0040] FIG. 7 —It shows a second modified example of the pressure-receiving member, and (a) is a perspective view of one pressure-receiving member and (b) is a perspective view of combined two pressure-receiving members.
[0041] FIG. 8 —It shows a third modified example of the pressure-receiving member, and (a) is a perspective view of one pressure-receiving member and (b) is a perspective view of combined two pressure-receiving members.
[0042] FIG. 9 —It shows a fourth modified example of the pressure-receiving member, and (a) is a perspective view of one pressure-receiving member and (b) is a perspective view of combined two pressure-receiving members.
[0043] FIG. 10 —It is a front and partial sectional view of the mill according to the modified example of the overall structure.
[0044] FIG. 11 —It is a front and sectional view of the mill according to the second embodiment of the present invention.
[0045] FIG. 12 —It is an enlarged view showing main parts of the mill according to the second embodiment.
[0046] FIG. 13 —It is an imaged figure showing the action of the mill according to the second embodiment.
[0047] FIG. 14 —It shows the pressure-receiving member according to the second embodiment, and (a) is a sectional view, (b) consists of a sectional view of a right half taken along lines A-A and a sectional view of a left half taken along lines B-B.
[0048] FIG. 15 —It shows the milling plate according to the second embodiment, and (a) is a perspective view and (b) is a sectional view.
[0049] FIG. 16 —It shows the configuration of a mechanism for changing discharge spout areas, and (a) shows the discharge spout with larger area and (b) shows the discharge spout with smaller area.
[0050] FIG. 17 —It is a front and sectional view of the mill according to the third embodiment of the present invention.
[0051] FIG. 18 —It shows an example of the milling plate used in the mill according to the third embodiment of the present invention.
[0052] FIG. 19 —It is a from and sectional view of the mill according to the fourth embodiment of the present invention.
[0053] FIG. 20 —It shows an example of the milling plate used in the mill according to the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0054] Hereinafter, embodiments of the mill according to the present invention will be set forth with reference to drawings. FIG. 1 is a front and partial sectional view of the mill according to a first embodiment of the present invention. The mill according to the first embodiment of the present invention comprises a cylindrical drum body ( 1 ) configured so that a to-be-milled material (raw materials) can be taken in through a part of the mill (a hopper ( 71 )) and be discharged from the other part (a discharge hopper ( 21 )), a central shaft ( 2 ) penetrating the drum body ( 1 ) in a longitudinal direction, a plurality of milling plates ( 4 ) which are attached with predetermined spacing in a longitudinal direction of the central shaft ( 2 ) and divide interior space of the drum body ( 1 ) into a plurality of milling chambers ( 6 ), and a pressure-receiving member ( 5 ) which is attached to the drum body ( 1 ) and faces the milling plate ( 4 ). On downstream side of the discharge hopper ( 21 ) is attached a sieve member ( 22 ) which rotates with the central shaft ( 2 ). Both ends of the central shaft ( 2 ) are supported by a pair of bearing members ( 16 ) and ( 17 ). To one end (upstream) of the central shaft ( 2 ) is coupled a motor (M) used as a drive source for rotating the central shaft ( 2 ) and to the other end (downstream) is attached the sieve member ( 22 ). The sieve member ( 22 ) has cylindrical shape with a taper whose diameter becomes gradually larger as it moves away from the drum body ( 1 ).
[0055] The drum body ( 1 ) is in a substantially cylindrical shape and consists of a combination of upper and lower semicylindrical members. A plurality of milling plates ( 4 ) are provided with predetermined spacing in a shaft direction of the central shaft and divide interior space of the drum both ( 1 ) into a plurality of milling chambers ( 6 ). Each milling plate ( 4 ) is inclined with respect to the pine intersecting the central shaft ( 2 ) at a right angle, and is substantially parallel to each other. Each milling chamber ( 6 ) has no milling media (a ball, a rod, etc) which mills the to-be-milled material by contacting the to-be-milled material therewith while moving by rolling in the drum body. A plurality of pressure-receiving members ( 5 ) is placed in each milling chamber ( 6 ) and intersects the central shaft ( 2 ) at right angles, respectively. For the mill of this embodiment, a to-be-milled material (a), together with water (b), are supplied from the hopper ( 71 ) and passed through each milling chamber ( 6 ) sequentially. Then, they are discharged from the discharge hopper ( 21 ) located at the most downstream side of the drum body ( 1 ) and sent to the sieve member ( 22 ). However, instead of such a wet construction, a dry construction sending the to-be-milled material (a) due to the action of rotation etc. of the milling plate with/without a blower may be employed. In addition, any of the wet construction or the dry construction may be employed in the below-described second to fourth embodiments.
[0056] FIG. 3 shows a milling plate according to the embodiment and (a) is a plan view, (b) is a side view, and (c) is a sectional view taken along lines IIIc-IIIc. The milling plate ( 4 ) has a substantially circular structure formed by combining two semicircle-like curved plates, and the central shaft ( 2 ) is inserted into as central hole ( 41 ). The milling plate ( 4 ) is attached to be inclined clockwise from the plane intersecting the central shaft ( 2 ) at a right angle. In addition, even if the inclined direction of the milling plate ( 4 ) is contrary to this embodiment, no disadvantage will arise for the milling processing, for the to-be-milled material (a) are moved due to water flow (in case of the we construction) or air flow (in case of the dry construction). The milling plate ( 4 ) has a plurality of partially-arc through holes ( 42 ) arranged in a concentric pattern. Arc width of the through hole ( 42 ) is set sufficiently small so that only the to-be-milled material which was milled to less than a predetermined particle size can pass therethrough. Size (arc width) of the through hole ( 42 ) may be gradually decreased from as milling plate ( 4 ) on upstream side of the drum body ( 1 ) towards a milling plate ( 4 ) on the downstream side. In case of obtaining final to-be-milled material with 0-25 mm, for instance, the size of the through hole ( 42 ) can sequentially be decreased to 50 mm, 40 mm, 35 mm, 30 mm, and 25 mm, from upstream towards downstream. This can be applied to the milling plates of the below-described second to fourth embodiments.
[0057] Furthermore, as shown in FIGS. 3( b ) and ( c ), a hemispherical convex part ( 43 ) is provided on surface of the milling plate ( 4 ) and thus a large concave-convex pattern is formed thereon. This large concave-convex pattern could have some good effect. For example, when the to-be-milled material (a) diagonally hit the stilling plate ( 4 ), they are rubbed by a convex part ( 43 ) by slightly sliding on the surface of the milling plate ( 4 ), which leads to improvement of the mill efficiency of the to-be-milled material (a). It is also possible to compose only the convex part ( 43 ) of the milling plate ( 4 ) of an especially hard material (for example, cemented carbide), reduce wear of the milling plate ( 4 ), and extend the period of endurance. Instead of the convex part ( 43 ) a large concave-convex pattern having relatively larger concave parts may be formed. In this case, the same effect as in the concave-convex having the convex part ( 43 ) can be achieved.
[0058] Here, the FIG. 1 shows a tabular milling plate ( 4 ) for easy recognition but the milling plate ( 4 ) in this embodiment has a wavy curved-surface structure where peaks and valleys are iteratively provided at certain spacing in a circumference direction, as shown in FIG. 3 . The wavy curved-surface structure means that it has peaks on the surface and valleys on the back surface. However, the milling plate ( 4 ) may have planar structure. The milling plate ( 4 ) may be not a circular plate but an elliptic plate as a whole. The similar curved-surface structure may be used for the below-described pressure-receiving member ( 5 ).
[0059] FIG. 2 shows a pressure-receiving member according to the embodiment, and (a) is a plan view, (b) is a sectional view taken along lines IIb-IIb. The pressure-receiving member ( 5 ) is divided into two parts in response to the semicylindrical drum body ( 1 ), and has a semidisc part ( 50 ) in a substantially semidisc shape and a flange part ( 54 ) surrounding outer periphery of the semidisc part ( 50 ). For the semidisc part ( 50 ), when the two pressure-receiving members ( 5 ) are combined, a semicircular inner periphery edge ( 51 ) is formed in the central part of the combined structure and faces the central shaft ( 2 ) with a predetermined spacing therebetween. The pressure-receiving member ( 5 ) is attached to the drum body ( 1 ) with screws (not shown), with an outer periphery ( 53 ) of the semicylindrical flange part ( 54 ) being in contact with inner wall of the drum body ( 1 ). The flange part ( 54 ) has insertion holes for screws ( 55 ).
[0060] For easy recognition, a cross sectional view of the pressure-receiving member ( 5 ) in FIG. 1 is omitted, but there are many partially-arc through holes ( 52 ) arranged in a concentric pattern on the semidisc part ( 50 ) of the pressure-receiving member ( 5 ). The arc width of the through hole ( 52 ) is set sufficiently small so that only the to-be-milled material (a) which was milled to less than a predetermined particle size in the milling chamber ( 6 ) can pass therethrough. Arc width of the through hole ( 52 ) may be gradually decreased from the pressure-receiving member ( 5 ) on upstream side of the drum body ( 1 ) towards the pressure-receiving member ( 5 ) on downstream side. In addition, the semidisc part ( 50 ) and the flange part ( 54 ) of the pressure-receiving member ( 5 ) have fine concave-convex patterns ( 57 ) formed by casting, press molding, or the like, as shown in the partial enlarged view of the FIG. 2 ( b ). The pressure-receiving member ( 5 ) in this embodiment has flat-plate structure, but, the pressure-receiving member ( 5 ) may have any curved-surface structures, as set forth below. For example, the pressure-receiving member ( 5 ) can be any protruded structure shaped when seen from the front view, such as, piled-cone structure shaped when seen from the front view and abacus's bead shaped when seen from front view. Moreover, the pressure-receiving member ( 5 ) may not be a circular plate but an elliptic plate as a whole when seen from side view. In addition, “when seen from front view or side view” means the mill when seen from front view or side view.
[0061] In the present invention, at least any one of the milling plate ( 4 ) and the pressure-receiving member ( 5 ) may rotate. However, this embodiment is configured so that the drum body ( 1 ) is fixed and the central shaft ( 2 ) rotates. Therefore, in this embodiment, the central shaft ( 2 ) rotates and the milling plate ( 4 ) attached to the central shaft ( 2 ) rotates, while the pressure-receiving member ( 5 ) attached to the drum body ( 1 ) remains stationary.
[0062] FIG. 6 is a sectional view for explaining milling action with the pressure-receiving member and the milling plate. As shown in the FIG. 6 , when the milling plate ( 4 ) rotates 180 deuces from a solid position, it reaches a dashed position. Then, the milling plate ( 4 ) iteratively rotates so that it will return to the solid position again. During the rotation, the to-be-milled material (a) are strongly pressed between the milling plate ( 4 ) and the pressure-receiving member ( 5 ) and subjected to friction force generated by the rotation of the milling plate ( 4 ) in a narrower room (Rm) created by approach of the milling plate ( 4 ) and the pressure-receiving member ( 5 ). As a result, the to-be-milled material (a) are rubbed by the pressure-receiving member ( 5 ) and the milling plate ( 4 ), or rubbed by each other, leading to efficient removal of foreign matters such as cement adhered to the surface of the to-be-milled material (a). The to-be-milled material (a) passes through the through holes ( 42 ) ( 52 ) of the milling plate ( 4 ) and the pressure-receiving member ( 5 ), the space (Sp 1 ) between the pressure-receiving member ( 5 ) and the central shaft ( 2 ), and the space (Sp 2 ) between the milling plate ( 4 ) and the drum body ( 1 ), and then is sent to the downstream side with water (b). At that time, edges of many through holes ( 42 ) ( 52 ) provided on the milling plate ( 4 ) and the pressure-receiving member ( 5 ) can scrape the foreign matters, too, thereby eliminating the foreign matters more effectively.
[0063] The structure of the mill according to the present invention is not limited, to the structure shown in FIG. 1 . For example, only the pressure-receiving member ( 5 ) may be rotated and the milling plate ( 4 ) may be fixed. In that case, only the drum body ( 1 ) rotates and even if the to-be-milled material (a) strongly hit the drum body ( 1 ), the milling plate ( 4 ), and the pressure-receiving member ( 5 ) due to the centrifugal three caused by the rotation of the drum body ( 1 ), loud noise such as the one caused by the clash of the drum body ( 1 ) and the milling media never occurs. Additionally, the rotation of the drum body ( 1 ) can provide large centrifugal force for the to-be-milled material (a), and thus the clash of the to-be-milled material (a) with the flange part ( 54 ) of the pressure-receiving member ( 5 ) improves the mill efficiency. Moreover, the milling plate ( 4 ) and the pressure-receiving member ( 5 ) may rotate in a reverse direction with respect to each other. In that case, the frictional force acting on the to-be-milled material (a) held between the milling plate ( 4 ) and the pressure-receiving member ( 5 ) can be increased, thereby improving the mill efficiency.
[0064] FIG. 5 is a sectional view showing the first modified example of the pressure-receiving member ( 5 ). In the pressure-receiving member ( 5 ) according to the first modified example, a flange part ( 54 ) with wider width than that shown in FIG. 2( b ) is provided, for example, it extends to a midway point of each ruffling chamber ( 6 ). Thus, making the width of the flange part ( 54 ) wider alloys an area of an inner side plane of the flange part ( 54 ) which a to-be-milled material (a) hits to become larger, leading to an increase of mill efficiency.
[0065] Also, as shown in the partially enlarged view of FIG. 5 , a fine concave-convex pattern ( 57 ) formed by sandblast etc. is formed on a surface of the semidisc part ( 50 ) or the flange part ( 54 ) of the pressure-receiving member ( 5 ). Due to the fine concave-convex pattern ( 57 ) shown in FIG. 2 ( b ) or FIG. 5 , when a to-be-milled material (a) diagonally hits the surface of the pressure-receiving member ( 5 ), it becomes likely to be rubbed hard without sliding on the surface of the pressure-receiving member ( 5 ). Therefore, providing the fine concave-convex pattern ( 57 ) on the pressure-receiving, member ( 5 ) allows mill efficiency of a to-be-milled material (a) to further increase. Providing the fine concave-convex pattern also on the ruffling plate ( 4 ) may increase mill efficiency of a to-be-milled material (a), although this is not shown in FIG. 3 . However, the fine concave-convex pattern is not necessarily provided on the milling plate ( 4 ) or the pressure-receiving member ( 5 ). Moreover, a large concave-convex pattern having a convex part and a concave part like a miffing plate ( 4 ) may be also farmed on the pressure-receiving member ( 5 ), although this is not shown in FIG. 2( b ) or FIG. 5 (See a modified example which will be mentioned later). In even such a case, the above-mentioned acting effect can be achieved.
[0066] Constituent materials of the milling plate ( 4 ) and the pressure-receiving member ( 5 ) include, but not limited to, general-purpose steel materials, high hardness iron and steel materials such as alloy steels, cemented carbides, ceramics, and metal-ceramics composite materials, etc. In order to increase mill efficiency or extend a durable period, the materials with higher hardness is preferable. Only a part, for example, a surface of the milling plate ( 4 ) or the pressure-receiving member ( 5 ) comprised, of general-purpose steel materials may be comprised of the high hardness materials. The same can be also applied to second to fourth embodiments which will be mentioned later.
[0067] FIG. 4 is a front and partial sectional view of a sieve member and conveyor device according to this embodiment. A guiding member ( 82 ) to receive a to-be-milled material (a 1 ) having a relatively small diameter which passed through a mesh of the sieve member ( 22 ) and a first delivery device ( 8 ) arranged below the guiding member ( 82 ) are arranged below the sieve member ( 22 ). To the first delivery device ( 8 ), is attached a first conveyor device ( 81 ) which delivers the to-be-milled material (a 1 ) backward from its position in FIG. 4 . Near a downstream side of the sieve member ( 22 ), is arranged a second delivery device ( 9 ) which receives a to-be-milled material (a 2 ) having a relatively large diameter which is delivered, without passing through a mesh of the sieve member ( 22 ). To the second delivery device ( 9 ), is attached a second conveyor device ( 91 ) which delivers the to-be-milled material (a 1 ) forward from its position in FIG. 4 .
[0068] As in this embodiment, the sieve material ( 22 ) is provided on a downstream end part of the mill and sorts milled to-be-milled materials into sizes depending on intended uses, and thus the sorting process can be continuously carried out with a milling process, allow overall efficiency to improve. The size of the mesh of the sieve member ( 22 ) can be optionally chosen depending on the type of an aggregate to be finally obtained. For example, in sorting the to-be-milled materials into gravel and sand, a mesh with a size of, for example, about 5 mm can be used. A punching metal (steel plate) is generally used for a material of the sieve member ( 22 ), but not specifically limited to this.
[0069] Also, as in this embodiment, an arrangement of the conveyor device ( 81 ) and ( 91 ) which carry the to-be-milled materials (a 1 ) and (a 2 ), respectively, allows a large sized container which separates and receives the sorted to-be-milled materials (a 1 ) and (a 2 ) for intended uses to be arranged without interfering with the mill. Besides, the number of a sieve member may be two or more pieces, and depending on that number, three or more conveyor devices (delivery devices) may be arranged. Next, modified examples of a pressure-receiving member ( 5 ) will be explained. FIG. 7 illustrates a second modified example of the pressure-receiving member, and (a) is a perspective view of one pressure-receiving member and (b) is a perspective view of combined two pressure-receiving members. The pressure-receiving member ( 5 ) according to the second modified example has a semidisc part ( 50 ) similar in shape to a milling plate ( 4 ) shown in FIG. 3 . That is, the semidisc part ( 50 ) consists of a curved surface inclining with respect to a plane intersecting at a right angle to a central shaft ( 2 ), and a large number of arranged convex parts ( 56 ) arranged in a concentric pattern (concave-convex pattern) and a large number of partially arc-shaped through holes ( 52 ) arranged in a concentric pattern are provided on the semidisc part ( 50 ), with its inner periphery edge ( 51 ) facing the central shah ( 2 ) with spacing therebetween. The arc width of the through hole ( 52 ) is set sufficiently small so that only the to-be-milled material (a) which was milled to less than a predetermined particle site can pass therethrough. A flange part ( 54 ) with wider width is provided as in the case in the first modified example, and the pressure-receiving member ( 5 ) is attached to a drum body ( 1 ) with a peripheral part ( 53 ) of the flange part ( 54 ) contacting with the drum body ( 1 ).
[0070] Thus, when a pressure-receiving member ( 5 ) is used with its semidisc part ( 50 ) inclining with respect to a plane intersecting at a right angle to a central shaft ( 2 ), the milling plate ( 4 ) preferably intersects at a right angle to a central shaft ( 2 ). The milling plate ( 4 ) may be a planar structure or curved-surface structure, for example the milling plate ( 4 ) in substantially same shape as the semidisc part ( 50 ) of the pressure-receiving member ( 5 ) in FIG. 2 can be used.
[0071] FIG. 8 illustrates a third modified example of the pressure-receiving member, and (a) is a perspective view of one pressure-receiving member and (b) is a perspective view of combined two pressure-receiving members. The pressure-receiving member ( 52 ) according to the third modified example has a semidisc part ( 50 ) intersecting at a right angle to a central shaft ( 2 ). A large number of arranged convex parts ( 56 ) arranged in a concentric pattern (concave-convex pattern) and a large number of partially arc-shaped through holes ( 52 ) arranged in a concentric pattern are provided on the semidisc part ( 50 ), with its inner periphery edge ( 51 ) facing the central shaft ( 2 ) with spacing therebetween. The arc width of the through hole ( 52 ) is set sufficiently small so that only the to-be-milled material (a) which was milled to less than a predetermined particle size can pass therethrough. A flange part ( 54 ) with wider width is provided as in the case in the first modified example, and the pressure-receiving member ( 5 ) is attached to a drum body ( 1 ) with a peripheral part ( 53 ) of the flange part ( 54 ) contacting with the drum body ( 1 ).
[0072] Thus, when a pressure-receiving member ( 5 ) is used with its semidisc part ( 50 ) inclining from a central shaft ( 2 ), the milling plate ( 4 ) preferably inclines with respect to a central shaft ( 2 ). The milling plate ( 4 ) may be a planar structure or curved-surface structure.
[0073] FIG. 9 illustrates a fourth modified example of the pressure-receiving member, and (a) is a perspective view of one pressure-receiving member and (b) is a perspective view of combined two pressure-receiving members. The pressure-receiving member ( 5 ) according to the fourth modified example has a semidisc part ( 50 ) and a flange part ( 54 ) which are in substantially same shape as the pressure-receiving member ( 5 ) according to the second modified example in FIG. 7 . A difference between the pressure-receiving member ( 5 ) according to the fourth modified example and the pressure-receiving member ( 5 ) according to the second modified example is that each semidisc part ( 50 ) is inclined in an opposite direction with respect to a plane intersecting at a right angle to a central shaft ( 2 ). That is, the pressure-receiving member ( 5 ) according to the second modified example is inclined in a clockwise direction with respect to a plane intersecting at a right angle to a central shaft ( 2 ), while the pressure-receiving member ( 5 ) according to the fourth modified example is inclined in a counterclockwise direct on with respect to a plane intersecting at a right angle to a central shaft ( 2 ). Regardless whether the pressure-receiving member ( 5 ) is inclined in to the direction in the second modified example or the direction in the fourth modified example, a to-be-milled material (a) is transferred smoothly and no disadvantage for a milling process will arise. Even in the case of using the pressure-receiving member ( 5 ) according to the fourth modified example, the milling plate ( 4 ) preferably intersects at a right angle to a central shaft ( 2 ). The milling plate ( 4 ) may be a planar structure or curved-surface structure, for example the milling plate ( 4 ) in substantially same shape as the semidisc part ( 50 ) of the pressure-receiving member ( 5 ) in FIG. 2 can be used.
[0074] As will be easily understood from above-described each modified example, structures or materials of the milling plate ( 4 ) and the semidisc part ( 50 ) of the pressure-receiving member ( 5 ) may be the same. In addition, one of the milling plate ( 4 ) and the semidisc part ( 50 ) of the pressure-receiving member ( 5 ) may incline from a plane intersecting at a right angle, or both may be inclined. Although both may not be necessarily inclined, there is preferably at least a narrow room (Rm) where the to-be-milled material (a) is held between the milling plate ( 4 ) and the pressure-receiving member ( 5 ).
[0075] All the above-mentioned milling plates and the pressure-receiving members can be applied even in second to fourth embodiments which will be described later.
[0076] Next, a modified example of a whole structure of a mill will be explained. FIG. 10 is a front and partial sectional view of the mill according to the modified example of the whole structure. As shown in the figure, the mill according to this modified example has a hopper ( 71 ) for putting in the to-be-milled material (a) (raw material) on a central part of the drum body ( 1 ), and a hopper for discharge ( 21 ), a sieve member ( 22 ), and a motor (M) on right and left sides of the churn body ( 1 ). Also, it has a sieve rotational shaft ( 2 a ) separated from the central shaft ( 2 ) to rotate one of the sieve members ( 22 ) (right side in the figure), and the central shaft ( 2 ) and the sieve rotational shaft ( 2 a ) are rotatably supported by a bearing member ( 18 ) with respect to each other. In addition, it may be possible to rotate the sieve members ( 22 ) together with the central shall ( 2 ) by connecting the motors (M) to both ends of the central shaft ( 2 ), respectively, and synchronizing and rotating the motors (M) on the both sides. In this case, the central shaft ( 2 ) and the sieve rotational shaft ( 2 a ) would be integrated. According to the structure of this modified example, it is possible to substantially improve processing capacity (by about twice) by putting in the raw materials from a center of the drum body ( 1 ) and discharging them from the sieve members on the both sides.
[0077] FIG. 11 is a sectional front view of the mill according to the second embodiment of the present invention, and FIG. 12 is an enlarged view of a main part of FIG. 11 . Hereinafter, different configuration between the mill according to the second embodiment of the present invention and that of the mill according to the above-mentioned first embodiment of the present invention will be set forth. Besides, same reference numbers are allotted to the same configurations as those of the mill of the above-mentioned first embodiment.
[0078] As in the case of the mill in FIG. 10 , the mill of the second embodiment has a hopper ( 71 ) for putting in the to-be-milled material (raw material) on a central part of the drum body ( 1 ), and a hopper for discharge ( 21 ), as sieve member ( 22 ), and a motor (M) on right and left sides of the drum body ( 1 ). On a downstream side of the sieve member ( 22 ), is arranged a second delivery device ( 9 ) which receives a to-be-milled material having a relatively large diameter which is delivered without passing through a mesh of the sieve member ( 22 ). To the second delivery device ( 9 ), a second conveyor device ( 91 ) is attached to deliver the to-be-milled material forward from the position in FIG. 11 . Besides, a guiding member to receive a to-be-milled material having a relatively small diameter which passed through the mesh of the sieve member ( 22 ) and a first delivery device arranged below the guiding member can be arranged below the sieve member ( 22 ) as shown in FIG. 4 (not shown in figures).
[0079] A plurality of milling plates ( 4 ) is provided in shaft length directions of the central shaft at a certain interval and divide in axial length directions an inner part of the drum body ( 1 ) into a plurality of milling; chambers ( 6 ). Each milling plate ( 4 ) is inclined at an angle (β) with respect to a plane intersecting at a right angle to the central shaft ( 2 ) (See FIG. 12 ), and rotates together with the central shaft ( 2 ). In the example shown in FIG. 11 , each milling plate ( 4 ) is provided in substantially parallel with each other, but not limited to this. In the example shown in FIG. 11 , the milling plates ( 4 ) in a right half of the drum hod ( 1 ) and those in a left half of the drum body ( 1 ) are oppositely inclined with respect to each other, but they may be inclined in the same direction. Etch milling chamber ( 6 ) has no milling media (ball, etc.) as in the case with the mill of the first embodiment.
[0080] A plurality of pressure-receiving members ( 5 ) is arranged on each milling chamber ( 6 ), and intersect at a right angle to the central shaft ( 2 ), respectively. The pressure-receiving members ( 5 ) have an inclined plane ( 51 B) which is inclined with respect to a plane intersecting at a right angle to the central shaft ( 2 ) so that a plane facing the milling plate ( 4 ) is in substantially circular truncated cone shape. The pressure-receiving members ( 5 ), in another shape, have a piled-cone structure (a shape where bottoms of two cones (truncated cones) are put together), or an abacus's head shape. A size of an inclined angle (α) to the central shall ( 2 ) of the inclined plane ( 51 B) is almost the same as that of an inclined angle (β) to the central shaft ( 2 ) of the milling plate ( 4 ).
[0081] Since the milling plate ( 4 ) is inclined with respect to a plane intersecting at a right angle to the central shaft ( 2 ) and rotates together with the central shaft ( 2 ), a trace of rotational movement of the milling plate is in a shape of figure eight. That is, the milling plate ( 4 ) repeatedly rotates moving to an imaginary-line position and back to a solid position in turn so as to move to a position shown with the imaginary lines (two-dot chain lines) when it rotates 180 degrees from the solid position shown with solid lines in FIG. 12 , and then it moves back to the solid position. Since the size of the inclined angle (α) with respect to a plane intersecting at a right angle to the central shaft ( 2 ) of the inclined plane ( 51 B) is almost the same as that of the inclined angle (β) with respect to a plane intersecting at a right angle to the central shaft ( 2 ) of the milling plate ( 4 ), a surface of the milling plate ( 4 ) always faces the inclined plane ( 51 B) of the pressure-receiving member ( 5 ) in parallel when the milling plate ( 4 ) rotates so that its trace will be the shape of figure eight. In particular, when the milling plate ( 4 ) is located on the solid position of FIG. 12 , a surface ( 44 ) of the milling plate ( 4 ) face the inclined plane ( 51 B) in parallel, and when the milling plate ( 4 ) is located on the imaginary-line position of FIG. 12 , a surface ( 45 ) of the milling plate ( 4 ) faces the inclined plane ( 51 B) in parallel.
[0082] Therefore, while the milling plate ( 4 ) is rotating, the to-be-milled material is rubbed between the surface ( 44 ) or ( 45 ) of the milling plate ( 4 ) and the surface of the pressure-receiving member ( 5 ) (inclined plane). In this case, since the milling plate ( 4 ) rotates in the shape of figure eight like a fan blade, the to-be-milled material is rubbed four times between the pressure-receiving member ( 5 ) and the milling plate ( 4 ) in one rotation of the milling plate ( 4 ), thereby greatly improving mill efficiency. Also, the milling plate ( 4 ) generates a wind like a fan while rotating. FIG. 13 is an imaged figure of the milling plate ( 4 ) which is likened to be a fan. The milling plate ( 4 ) generates a wind like a fan while rotating (See rightward arrows in FIG. 13 ), allowing the to-be-milled material to be easily transferred within the drum body. Especially, this allows the to-be-milled material to easily pass through the through holes provided on the pressure-receiving member ( 5 ).
[0083] FIG. 14 illustrates the pressure-receiving member ( 5 ) according to the second embodiment, and (a) is a sectional view and (b) is a A-A line sectional view of (a) (right half of (b)) and a B-B line sectional view of (a) (left half of (b)). The pressure-receiving member ( 5 ) shown in FIG. 14 is in a piled-cone structure shape or an abacus's bead shape when seen from front view, as shown in FIG. 14 ( a ). Besides, a front view and side view here mean a front view and side view of the mill. The pressure-receiving member ( 5 ) is fixed to the drum body ( 1 ) by being attached to a mounting member ( 20 ) fixed to an inner surface of the drum body ( 1 ). The mounting member ( 20 ) consists of a fixed part ( 20 a ) fixed by bolts to a bottom surface of an inner wall of the drum body ( 1 ) and a plate-like extending part ( 20 b ) extending upwards from this fixed part ( 20 a ) and in a direction to intersect at a right angle to the central shaft ( 2 ). An upper end of the extending part ( 20 b ) readies a vicinity of a top surface of the inner wall of the drum body ( 1 ).
[0084] The pressure-receiving member ( 5 ) is in a circle shape, consisting of a combination of two members in substantially semicircular shapes when seen from the central shall direction ( 2 ) (members in the semicircular shape of an upper half and a lower half). A central hole ( 57 ) which the central shaft ( 2 ) is inserted into is formed on a position corresponding to this circular central part. A large number of partially arc-shaped through holes ( 52 B) arranged in a concentric pattern are formed on the pressure-receiving, member ( 5 ). The arc width of the through hole ( 52 B) is set sufficiently small so that only the to-be-milled material (a) which was milled, to less than a predetermined, particle size in the milling chamber ( 6 ) can pass therethrough. The arc width of the through hole ( 52 B) may be gradually decreased from the pressure-receiving member ( 5 ) on upstream side of the drum body ( 1 ) towards the pressure-receiving member ( 5 ) on downstream side. A through hole and a central hole are also provided on the extending part ( 20 b ), and shapes and arrangements of this through hole and central hole correspond with the shapes and arrangements of the through hole ( 52 B) and the central hole ( 57 ), respectively.
[0085] A bolt insertion hole ( 58 ) is provided on the pressure-receiving member ( 5 ). It is possible to fix the pressure-receiving member ( 5 ) to the mounting member ( 20 ) by fitting the mourning member ( 20 ) into a slot which is provided inside the pressure-receiving member ( 5 ) and then inserting a bolt in the bolt insertion hole ( 58 ) and fastening it with a nut. In an example of the figures, deep holes are provided on a plurality of places of the pressure-receiving member ( 5 ), and a spacer ( 59 ) having the bolt insertion hole and a shape matching the deep hole is fit into each deep hole. It is possible to fix the pressure-receiving member ( 5 ) to the mounting member ( 20 ) by pinching the mounting member ( 20 ) with a pair of spacers ( 59 ) and then inserting a bolt and fastening it with a nut. Thereby, bolts and nuts are prevented from abrading due to the to-be-milled material without protruding from a surface of the pressure-receiving member ( 5 ).
[0086] The pressure-receiving member ( 5 ) is in a piled-cone structure shape when seen from front view or an abacus's bead shape when seen from front view, as mentioned above, and its thickness increases horn its periphery edge toward the central hole ( 57 ). Therefore, the pressure-receiving member ( 5 ) has the inclined plane ( 51 B) which is inclined with respect to a plane intersecting at a right angle to the central shaft ( 2 ) so that a plane facing the milling plate ( 4 ) is in substantially circular truncated cone shape.
[0087] The pressure-receiving member ( 5 ) of the second embodiment can be also used in the above-mentioned mill of the first embodiment.
[0088] FIG. 15 illustrates the milling plate according to the second embodiment, and (a) is a perspective view and (b) is a sectional view. Besides, this milling plate can be also used in the mill of the above-mentioned first embodiment. This milling plate ( 4 ) has as structure similar to that in FIG. 3 . The milling plate ( 4 ) has a substantially circular structure where two semicircle curved plates were put together, and a cylindrical body ( 46 ) having a hole which the central shaft ( 2 ) is inserted into is fixed to a center of the milling plate ( 4 ). The cylindrical body ( 46 ) is fixed inclining with respect to the milling plate ( 4 ). Thus, when the cylindrical body ( 46 ) is attached to the central shaft ( 2 ), the milling plate ( 4 ) is attached inclining from a plane intersecting at a right angle to the central shaft ( 2 ). Besides, such cylindrical body ( 46 ) is not shown in FIG. 3 , but it can be also attached to the milling plate in FIG. 3 . A plurality of partially arc-shaped through holes ( 42 ) arranged in a concentric pattern are provided on the milling plate ( 4 ). The arc width of the through hole ( 42 ) is set sufficiently small so that only the to-be-milled material (a) which was milled to less than a predetermined particle site can pass therethrough. The arc width of the through hole ( 42 ) may be gradually decreased from the milling plate ( 4 ) on upstream side of the drum body ( 1 ) towards the milling plate ( 4 ) on downstream side.
[0089] The milling plate ( 4 ) in this embodiment has a wavy curved-surface structure so that peaks and valleys are repeated at a certain interval in a peripheral direction. In addition, the wavy curved-surface structure means that a peak part on the surface side is a valley part on the reverse side. In an example of the figures, the wavy structure has four peaks and valleys, respectively, in other words, four S-shaped planes are consecutively formed along with a peripheral direction. Thereby, when the milling plate ( 4 ) rotates once, a to-be-milled material is rubbed four times between the milling plate ( 4 ) and a surface of the pressure-receiving member ( 5 ). However, the milling plate ( 4 ) may have a planar structure. Moreover, the milling plate ( 4 ) may not be a circular plate but an elliptic plate as a whole. A circular member ( 47 ) is attached to an outer edge part of the milling plate ( 4 ) so as to be along the outer edge part.
[0090] FIG. 16 illustrates a configuration of a mechanism for changing discharge spout area, and (a) illustrates a discharge spout with larger area and (b) illustrates a discharge spout with smaller area. The mechanism for changing discharge spout area ( 10 ) changes a size of the discharge spout ( 11 ) which discharges a to-be-milled material from the drum body ( 1 ). The discharge spout ( 11 ) is provided on a position close to a lower part of both ends of the drum body ( 1 ), and a to-be-milled material discharged from the discharge spout ( 11 ) is transferred to the sieve member ( 22 ). The mechanism for changing discharge spout area ( 10 ) comprises an oil hydraulic cylinder ( 12 ), and a cover plate ( 13 ) which reciprocally moves in accordance with expansion and contraction of a rod of this oil hydraulic cylinder ( 12 ). If the rod of the oil hydraulic cylinder ( 12 ) contracts, the cover plate ( 13 ) moves downward, and a discharge spout ( 11 ) area (area not covered with a cover body ( 13 )) becomes larger, as shown in FIG. 16 ( a ). On the other hand, if the rod of the oil hydraulic cylinder ( 12 ) expands, the cover plate ( 13 ) moves upwards, and the discharge spout ( 11 ) area (area not covered with the cover body ( 13 )) becomes smaller, as shown in FIG. 16 ( b ). Thus, it is possible to adjust residence time (milling processing time) of a to-be-milled material within the drum body and to can out an appropriate milling process according to a type of the to-be-milled material by adjusting the discharge spout ( 11 ) area.
[0091] In the present invention, the pressure-receiving member ( 5 ) in the mill of the first embodiment and the pressure-receiving member ( 5 ) in the mill of the second embodiment can also be removed. If the pressure-receiving member is removed, mill efficiency can decrease compared with the case where the pressure-receiving member is used but to-be-milled materials are milled by being rubbed by an inner surface of the drum body or a surface of the milling plate, or rubbed with each other. In this case, in order to improve mill efficiency, it is preferable to narrow an interval (pitch) between the placed milling plates compared with the case where the pressure-receiving member is used.
[0092] FIG. 17 is a front and sectional view of a mill according to a third embodiment of the present invention. Hereinafter, a different configuration between the mill according to the third embodiment of the present invention and that of the mill according to the above-mentioned second embodiment (see FIG. 11 ) of the present invention will be mainly set forth. Same reference numbers are allotted to the same configurations as those of the mill of the above-mentioned second embodiment.
[0093] As in the case of the mill in the second embodiment, the mill of the third embodiment has a hopper ( 71 ) for putting in the to-be-milled material (raw material) above a central part of the drum body ( 1 ) in a longitudinal direction. And as in the case of the mill in the second embodiment, it has a hopper for discharge ( 21 ), a sieve member ( 22 ), and a motor (M) on right and left sides of the drum body ( 1 ), which is not shown in the figures.
[0094] A plurality of milling plates ( 4 ) are provided with predetermined spacing in a shaft direction of the central shaft ( 2 ) penetrating inside the drum body ( 1 ) and divide interior space of the drum body ( 1 ) into a plurality of milling chambers ( 6 ) in a shaft length direction. Each milling plate ( 4 ) is inclined with respect to the plane intersecting the central shaft ( 2 ) at a right angle, and rotates together with the central shaft ( 2 ). The milling plates ( 4 ) in a right half of the drum body ( 1 ) and those in a left half of the drum body ( 1 ) in a longitudinal direction are oppositely inclined with respect to each other. In FIG. 17 , the milling plate ( 4 ) in the right half of the drum body ( 1 ) is inclined to a diagonally downward right direction and the milling plate ( 4 ) in the left half of the drum body ( 1 ) is inclined to a diagonally downward left direction. As in the case of the mill in the first embodiment, each milling chamber ( 6 ) has no milling media (a ball, etc.).
[0095] FIG. 18 illustrates an example of the milling plate ( 4 ) for use in the mill according to the third embodiment. The milling plate ( 4 ) consists of a circular (or an elliptical) plate having central holes in which the central shaft ( 2 ) is inserted and has a large number of through holes ( 42 ) consisting of elongate holes arranged substantially equally and substantially concentrically (or an elliptically concentric pattern) throughout the milling plate ( 4 ). The through holes ( 42 ) allow adjoining milling chambers ( 6 ) to be in communication with each other and are set sufficiently small so that only the to-be-milled material which was milled to less than a predetermined particle size can pass therethrough. Besides, the milling plate ( 4 ) in FIG. 20 , which will be explained later, can be used in the mill according to the third embodiment.
[0096] A plurality of blocks ( 30 ) are attached to the milling plate ( 4 ) so as to protrude from both sides of the milling plate ( 4 ). The blocks ( 30 ) are attached to the milling plate ( 4 ) at substantially equal intervals along its periphery edge and extend towards a center of the milling plate ( 4 ) in areas between adjoining through holes ( 42 ) in peripheral directions. The blocks ( 30 ) can function to improve mill efficiency by contacting with to-be-milled materials. However, milling plates ( 4 ) without the blocks may be used in the third embodiment.
[0097] A plurality of pressure-receiving members ( 5 ) is placed in each milling chamber ( 6 ) and intersects the central shall ( 2 ) at right angles, respectively. The pressure-receiving member ( 5 ) is in a tabular shape so as to intersect the central shaft ( 2 ) at right angle, as in the case with the mill in the first embodiment (see FIG. 1 ). In this embodiment (third embodiment), use of such pressure-receiving member ( 5 ) in a tabular shape has advantages compared to the mill in the second embodiment (see FIG. 11 ) using as pressure-receiving member ( 5 ) having a piled-cone (truncated cone) structure or an abacus's bead shape as follows; First, a volume of to-be-milled materials to be contained in each milling chamber ( 6 ) increases due to increase of a volume in each milling chamber ( 6 ), resulting in an increase in processing efficiency. Second, since the pressure-receiving member ( 5 ) is relatively easy to be manufactured, manufacturing efficiency of the pressure-receiving member ( 5 ) increases, which is suitable for mass production.
[0098] Since the mills of the second and third embodiments have a hopper ( 71 ) for putting in the to-be-milled material (raw material) on a central part of the drum body ( 1 ) in a longitudinal direction, the to-be-milled materials taken inside the drum body ( 1 ) from the hopper ( 71 ) can be taken out separately from a discharge spout ( 11 ) provided on left and right ends after they are transported to rightward and leftward of the drum body ( 1 ), respectively and they are milled. Thus, mill efficiency with the mills of the second and third embodiments is twice as high as a mill transporting to-be-milled materials in only one direction from one end to the other end of the drum body.
[0099] FIG. 19 is a front and sectional view of a mill according to a fourth embodiment of the present invention. Hereinafter, a different configuration between the mill according to the fourth embodiment of the present invention and that of the mill according to the above mentioned third embodiment (see FIG. 17 ) of the present invention will be mainly set forth. Same reference numbers are allotted to the same configurations as those of the mill of the above-mentioned third embodiment.
[0100] The mill of the fourth embodiment has a hopper ( 71 ) for putting in the to-be-milled material (raw material) on one end of the drum body ( 1 ) in a longitudinal direction and a discharge spout ( 11 ) for taking the milled to-be-milled materials out of the drum body ( 1 ) on the other end of the drum body ( 1 ) in a longitudinal direction. Thus, in the mill of the fourth embodiment, as in the case of the mill in the first embodiment, to-be-milled materials are transferred in one direction from one end to the other end of the drum body ( 1 ) and taken out therefrom.
[0101] FIG. 20 illustrates an example of the milling plate ( 4 ) for use in the mill according to the fourth embodiment. The milling plate ( 4 ) consists of a circular (or an elliptical) plate having central holes in which the central shaft ( 2 ) is inserted. The milling plate ( 4 ) is provided with through holes ( 42 ) only in the vicinity of a central hole (that is, in the vicinity of the central shaft ( 2 )). In particular, the milling plate ( 4 ) has a plurality of through holes ( 42 ) (6 holes in FIG. 20 ) aligned at certain intervals in a peripheral direction only in the vicinity of the central hole. It is preferable that the through holes ( 42 ) are specifically arranged only on an inner circular portion of the milling plate ( 4 ) whose radius is half of that of the milling plate ( 4 ), but it is not limited to this. The through holes ( 42 ) allow adjoining milling chambers ( 6 ) to be in communication with each other and are set sufficiently small so that only the to-be-milled material which was milled to less than a predetermined particle size can pass therethrough. Therefore, as in FIG. 20 , if the through holes ( 42 ) are provided only in the vicinity of the central hole, milled to-be-milled materials is unlikely to pass through the through holes ( 42 ). As a result, residence time of the to-be-milled materials in each milling chamber increases, allowing foreign substances (mortars, etc.) adhered to surfaces of the to-be-milled materials (scrap materials of concrete, etc.) to be securely removed, thereby improving the quality of recycled aggregate to be reclaimed.
[0102] The milling plate ( 4 ) in FIG. 20 can be used in the mill in the above-mentioned first to third embodiments. Additionally, blocks ( 40 ) in FIG. 18 may be attached to the milling plate used in the mill in the fourth embodiment.
EXAMPLES
[0103] Hereinafter, the examples of the mill according to the present invention are shown in order to clarify effects of the present invention. However, the present invention is not limited to the following examples.
Manufacture of Recycled Fine Aggregate for Concretes
[0104] A milling process of concrete scrap materials (concrete shells) was conducted using the mill of the second embodiment ( FIG. 11-FIG . 16 ), in order to study properties of the aggregate after the milling process. Results are shown in the following tables. As shown in the following tables, the aggregate after milling process satisfied the standard values of JIS in all test items.
[0000]
TABLE 1
Test items
Standard values
Test values
Face dry density (JIS A 1110)
—
2.66
Water absorption rate (JIS A 1110)
3.0% or less
1.25
Absolute dry density (JIS A 1110)
2.5 g/cm 3 or
2.63
more
Particle quantity of aggregate (JIS A 1103)
7.0% or less
4.4
Mass of unit volume (JIS A 5005)
—
1.78
Mass of unit volume for solid volume
—
1.50
percentage for shape
determination (JIS A 5005)
Solid volume percentage for shape
55% or more
57.0
determination (JIS A 5005)
Alkali silica reaction test (Rapid method
—
Determined
JIS A 1804-2009)
as harmless
[0000]
TABLE 2
Sieve analysis test (JIS A 1102)
Sieve opening
Cumulative residual
Residual
Percentage
(mm)
mass (g)
percentage (%)
passing (%)
10
0
0.0
100.0
5
0
0.0
100.0
2.5
150
28.8
71.2
1.2
260
49.7
50.3
0.6
341
65.3
34.7
0.3
429
82.0
18.0
0.15
510
97.6
2.4
Total
521
100.0
Fineness modulus
3.24
INDUSTRIAL APPLICABILITY
[0105] The mill according to the present invention is used, for example, to obtain a recycled aggregate from concrete scrap materials or asphalt scrap materials, or to process soft stones included in natural aggregates.
EXPLANATION OF REFERENCE NUMBERS
[0000]
a To-be-milled material
b Water
1 Drum body
2 Central shaft
22 Sieve member
4 Milling plate
41 Central hole.
42 Through hole
44 Surface of a milling plate
45 Surface of a milling plate
5 Pressure-receiving member
50 Semidisc part
51 Inner periphery edge
52 Through hole
54 Flange part
51 B Inclined plane
6 Milling chamber
8 First delivery device
81 First conveyor device
9 Second delivery device
91 Second conveyor device
10 Mechanism for changing a discharge spout area
11 Discharge spout of the drum body
α Inclined angle with respect to a plane intersecting at right angle to a central shall of the inclined plane
β Inclined angle with respect to a plane intersecting at right angle to a central shaft of the milling plate | To provide a mill that can greatly reduce noise during operation and can also contribute to greater device compactness. The mill is provided with: a tubular drum body configured in a manner so that a material to be milled introduced from one section can be discharged from another section; a central shaft that penetrates within the drum body in the direction of tube length thereof; and a plurality of milling plates that are attached at a predetermined interval in the axial direction of the central shaft, and that compartmentalize the interior space of the drum body in to a plurality of milling chambers. The drum body and/or the milling plates rotate, and the mill does not have a milling medium that mills the material to be milled by contacting the material to be milled while rolling within the drum body. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation application to the commonly assigned, copending United States Application Ser. No. 06/833,987, filed Feb. 26, 1986, entitled "TREATMENT OF COTTON", now U.S. Pat. No. 4,796,334; this application is also related to and a divisional of the commonly assigned, copending United States Application Ser. No. 07/132,790, filed Dec. 10, 1987, entitled "TREATMENT OF COTTON", now U.S. Pat. No. 4,888,856.
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of a device for processing cotton. Sticky contaminants, resulting from a variety of insects, and especially from the white fly (Bamessia), for instance, are frequently present on cotton when this is picked. Such contaminants, generally referred to as "honeydew" renders the cotton sticky, and this causes severe problems, especially during the drawing of the slivers: as these pass through the conventional pairs of rollers, the honeydew causes adhesion to these rollers, further fibers become attached and the end-result is a work stoppage and the necessity to clean the rollers. This results in a lack of uniformity of the slivers and yarns which are produced, in serious time losses and increase of production costs with a reduction of quality of the product.
Although the quantity of such honeydew quantified by the content of reducing sugars contained therein, is generally quite low (of the order of 0.1 to 1.5 percent by weight), it causes serious problems during the various steps of the processing of cotton, and especially in the spinning process. The present invention overcomes to a large extent the problem caused by such adhesive substances and renders them harmless.
The contamination of the cotton with honeydew or the like causes problems in the processing of the cotton, at its various stages.
It is clear that the process of the invention is applicable at any of the stages of the processing of the cotton, and an early stage is of course advantageous.
Serious problems are generally encountered with such contaminated cotton during the processing on the draw frame. In the spinning process of cotton, a web is formed on a carding machine. Separation of fiber tufts into individual fibers and forming the web are done on a revolving flat card, which is a particular type of carding machine. After leaving the card, the web is pulled through a funnel-shaped hole and thus there is formed a so-called card sliver. To produce a yarn, the sliver has to be attenuated, possibly combed, and finally twisted. Six to eight slivers are fed to a draw frame, and these are drawn into one, and this operation is accompanied by attenuation or drafting,
SUMMARY OF THE INVENTION
Therefore with the foregoing in mind it is a primary object of the present invention to provide a new and improved device for processing cotton and which device permits at least partially eliminating the problems which are caused by the presence of sticky materials like honeydew and the like at the cotton.
Another and more specific object of the present invention is directed to providing a new and improved construction of a device for processing cotton and which device permits at least partially removing sticky materials such as honeydew and the like from the cotton.
A further significant object of the present invention is directed to a new and improved construction of a device for processing cotton and which device permits at least partially removing sticky materials such as honeydew and the like and can be readily integrated into existing installations for processing cotton.
Another, still important object of the present invention relates to a new and improved construction of a device for processing cotton and which device permits at least partially removing sticky materials such as honeydew and the like and is capable of being integrated at an early stage into existing installations for processing cotton.
Still another significant object of the present invention is directed to the provision of a new and improved construction of a device for processing cotton and which device permits at least partially removing sticky materials such as honeydew and the like and can be operated in a continuous manner.
Yet a further significant object of the present invention aims at providing a new and improved construction of a device for processing cotton and which permits at least partially removing sticky materials such as honeydew and the like and operates in a relatively simple and extremely economical manner, is highly reliable, not readily subject to breakdown or malfunction and requires a minimum of maintenance and servicing operations.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the device of the present development is manifested, among other things, by the features that, cotton is exposed to a heat source having a predetermined temperature and is heated to a preselected maximum temperature during exposure to such heat source. The cotton is exposed to the heat source for a predetermined period of time sufficient for transforming sticky material such as honeydew and the like which is adhered to the cotton, to a hard and brittle, readily removeable material.
It is known that during laboratory tests when cotton containing honeydew is heated in a stationary manner during about 2 hours at 130° C., such cotton becomes colored yellow to yellowish-brown, as this becomes discolored by caramelized honeydew.
it has now been discovered that by subjecting cotton to a controlled heating process with a maximum of about 140° C. during a controlled period of time with a maximum of 10 seconds, and advantageously up to about 5 seconds with cotton slivers, such droplets can be rendered brittle and hard losing their adhesive properties without adversely affecting the cotton quality. The heating may be effected at any step of the process, but preferably before the drawing of the cotton slivers on the draw frame, as at this stage the most serious problems occur.
There are provided simple devices, e.g. comprising a number of rotary rollers, the surface temperature of which is maintained at a predetermined value, means being provided for passing the cotton sliver over such heated rollers so as to maintain contact for an adequate period of time to convert the sticky material to hard and brittle particles.
The heating device can be provided at any stage of an installation for processing cotton fibers. It has been found that when the cotton is heated so as to reach a temperature of about 70° to 140° C., and maintained at such temperature for an adequate period of time, adhering honeydew droplets are converted to hard and brittle particles. The overall heating time of the cotton is about 1/2 to about 5 seconds for slivers and up to 10 seconds for cotton bales (upper surface), and such heating substantially reduces the stickiness of the fibers or eliminates it altogether.
BRIEF DESCRIPTION OF THE DRAWINGS
In the enclosed schematical drawings, which are not according to scale:
FIG. 1 is a perspective view of a first exemplary embodiment of the device of the invention in combination with a conventional drawing frame;
FIG. 2 is a perspective side-view of part of such device with three heated rollers;
FIG. 3 is a perspective view of three rollers and shows details of the heating means;
FIG. 4 illustrates constructional details of the roller system shown in FIG. 2;
FIG. 5 is an elevational sectional view through a further exemplary embodiment of a heating device according to the invention for processing cotton fiber sliver;
FIG. 6 is a perspective side-view of another exemplary embodiment of the inventive device for processing cotton bale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of a cotton processing device has been shown as needed for those skilled in the art to readily understand the method of treating cotton and the underlying principals and concepts of the present development, while simplifying the showing of the drawings. Turning attention now specifically to FIG. 1 of the drawings, the device illustrated therein by way of example and not limitation will be seen to comprise a device for processing cotton, and containing, for example, the conventional draw frame 17.
As shown in FIG. 1 cotton slivers 11 are drawn from the six cans 12 and over flat surface 13 under roller 14, and through the rotatory rollers 15 and 16, and from these to the conventional draw frame 17 which comprises 4 roller pairs 18, 19, 20 and 22, from which the resulting sliver 23 is drawn into the container 24.
The rollers 15 and 16 are provided with internal electrical heating means which are provided with heat control means, so that the surface temperature of the rollers 15 and 16 can be adjusted to any predetermined value. Various experiments have shown that generally surface temperatures of from about 150° C. and to about 230° C. are satisfactory. The cotton slivers 11 are pressed over the said rollers 15 and 16 at a speed of about 30 m/min (or 50 cm/sec). The cotton slivers 11 tested were 4 g/m sticky cotton, contaminated with considerable quantities of honeydew. The contact length of the cotton slivers 11 with the rollers was a total of about 55 cm and the cotton sliver was heated during this period of time in such manner that it reached a temperature of about 75° C. The heating to this temperature for the contact time indicated, was adequate to render the adhesive droplets hard and brittle. When the conventional device was used without this attachment, the cotton slivers stuck to the roller pairs and caused serious problems. When the rollers are heated to a higher temperature, the time of contact can be decreased.
Details of a three-roller system for use with, for example, the drawing frame 17 is shown in FIG. 3. The rollers 21, 22 and 23 are provided with internal electrical heating coils and with electrical leads for connection with a power source. Heating of the electrical resistance elements results in a predetermined surface temperature of the rollers 21, 22 and 23 and such temperature may be automatically maintained within a narrow range by means of a thermostat.
FIG. 2 illustrates such a device provided with the three electrically heated rollers 21, 22 and 23, from which the slivers move to the draw frame, the first pair of rollers of which, 24 and 25, are shown. The dimensions of the rollers 21, 22 and 23, and the configuration of these are shown in detail in FIG. 4. The rollers 21, 22, and 23 have each a diameter of 85 mm and the distance between the surfaces of these rollers is 30 mm. The total length of contact from the points A to B, plus C to D, plus E to F, of the cotton sliver 11 moving in the direction M about the three rollers of the device of the invention, is about 55 cm. Heating of the cotton sliver 11 to a minimum temperature of 70° C. at a velocity of 30 m/min renders the adhering honeydew droplets brittle and hard. When the cotton sliver 11 is moved at a higher velocity there must be used a higher surface temperature and/or a longer path of contact with the heated surfaces. The further processing of the cotton slivers does not cause any problems. The hard droplets are subsequently crushed to powder or to small particles, and can be sucked off. No adverse effect was observed as regards cotton quality or color. It is generally advisable to allow the cotton to attain equilibrium with ambient humidity before further processing.
It should be clear that the rollers may be heated with hot air, hot liquid and that any combination of heat conduction, convection and radiation may be used in the heating process.
As shown in FIG. 5, there is provided a system comprising four heated rollers 51, 52, 53 and 54, each of which is provided with a heating element (not shown) which maintains during operation a predetermined and preselected surface temperature.
As shown, the system comprises a support frame 55 on which there are mounted the heated rollers 51 and 52, whereas the rollers 51 and 54 are mounted on a movable frame 56.
When frame 56 is in the A position, the cotton sliver 57, from container 58, passes essentially in contact with half the circumference of each of the rollers 51 to 54, as shown in the figures, and through roller pairs 59 and 60, which are synchronized with the other rollers. In this position, the cotton sliver 57 takes the configuration shown by the full line. When for any reason the process is to be interrupted, in order to prevent overheating, frame 56 is moved towards the right, reaching the position indicated in dashed lines, A', with the cotton sliver 57' in the dashed configuration in which this cotton sliver 57' is out of contact with any heated surface. This movement can automatically be actuated whenever the process is to be temporarily interrupted. When treatment of the cotton sliver 57 is to be resumed, the device is actuated, the right-hand-side rollers 53 and 54 move again to the position adjacent to the left-hand ones, which takes a few seconds. Only after the rollers 53 and 54 have again reached the original position, is the movement of the cotton sliver 57 actuated. It is of course possible to use any number of heated rollers, from 3 upwards, with at least one being on the right-hand side frame.
The surface temperature does not differ from that set out in the other embodiments, and also the period of time during which the cotton sliver is in touch with the heated rollers. A further embodiment of the invention is illustrated with reference to FIG. 6. Raw cotton is supplied in the form of bales 63, and flock or tufts 62, detaching machines are used in order to gradually remove the cotton in the form of tufts which are removed by a moving device. The tufts are removed by means of a wheel 61 in a plurality of passes over the bales 63 which are arranged in line, and thus there is also comprised a homogeneous blend of a plurality of bales, resulting in a uniform product. The thickness of the cotton layer which is removed in each pass can be preselected within a rather wide range. The tufts are sucked by a vacuum system (not shown) into a further stage of processing.
The wheel 61 is provided with a plurality of teeth or other structures for plucking the tufts 62 and which rotate so as to remove the tufts of cotton as the device passes over the bales of cotton 63, the tufts being sucked by means of the vacuum system into section 64. According to the invention there are provided heating devices 65 and 66, with heating means adapted to maintain the surface of the plates in contact with the cotton at a predetermined and preselected temperature as the device moves over said bales. When the device moves from left to right, the heating device 65 is heated, when the movement is in the opposite direction, heating device is heated. The contact of the heated plates with the upper layer of the cotton is such that it renders the honeydew particles (droplets) brittle and hard. Such attachment may be used in addition to said heated-roller devices of the invention, or it may be used, to a large extent, instead of the roller devices. According to a preferred embodiment, both plates 65 and 66 are heated.
It should be clear that the device of the invention can be installed before the blending of the slivers to a single sliver on the draw frame. The device, in fact, can be installed at any preceding stage of the cotton processing installation.
It should be clear that the heating, after ginning, at the gin or at the spinning mill, to a temperature of above 70° C. can be effected by various means such as hot air, IR heating or the like, as set out above. The invention is intended to encompass any means adequate to heat-treat cotton fibers before or during processing at the spinning mill. This treatment results in rendering of the adhesive sticky honeydew droplets hard and brittle. The devices for heating the upper surfaces of cotton bales can also be provided as separate entities, to be used in conjunction with flock-detaching machines. The hard and brittle droplets are generally crushed to small particles or powder as the slivers pass through the draw frames, or they can be passed through a pair of crushing rollers. Such particles and powder is advantageously removed by a vacuum suction system.
While there are also shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. | The invention relates to a process for rendering harmless sticky material adhering to cotton fibers, termed "honeydew". According to the process the cotton is heated for a brief period of time to a temperature adequate to render said honeydew hard and brittle, and this without adversely affecting the cotton fibers. There are also provided means for effecting such treatment of cotton fibers in a continuous manner. | 3 |
FIELD OF THE INVENTION
This invention relates to lubricating oils containing additives that impart low friction and friction retention characteristics during oil use.
BACKGROUND OF THE INVENTION
The reduction in friction performance in lubricants has been pursued in the industry for a number of years. Because of environmental concerns, industry more recently is focusing on enhancing the fuel economy benefits over extended periods of oil use.
U.S. Pat. No. 4,178,258 teaches a lubricating oil for use in spark ignition and compression ignition engines which exhibits enhanced antiwear and friction characteristics by containing an antiwear amount of a molybdenum bis(dialkyl dithiocarbamate). The lubricant is described as being especially effective in reducing wear and friction if the lubricant also contains a zinc dialkyldithiophosphate (ZDDP).
U.S. Pat. No. 4,395,434 teaches an antioxidant additive combination for lube oils prepared by combining a sulfur containing molybdenum compound prepared by reacting an acidic molybdenum compound, a basic nitrogen compound and carbon disulfide with an organic sulfur compound. The organic sulfur compound is described as including metal dialkyldithiophosphates, and metal dithiocarbamates, among other organic sulfur compounds.
U.S. Pat. No. 4,529,526 teaches a lubricating oil composition comprising a base oil and a sulfurized oxymetal organic phosphorodithioate and/or a sulfurized oxymetal-dithiocarbamate and at least one zinc alkylcarbyl dithiophosphate, along with a calcium alkybenzene or calcium petroleum sulfonate and an alkenylsuccinic acid imide.
U.S. Pat. No. 4,786,423 teaches an improved lubricant which contains a mineral or synthetic base stock oil and two heavy metal compounds as well as a metal and sulfur free phosphorous compound. The heavy metal compounds can be molybdenum dithiocarbamate in combination with zinc dialkyldithiophosphate. The other phosphorous compound can be trialkyl or triaryl phosphate. The lubricant is prepared by, for example, heating the base stock to between room temperature and about 100° C. for two hours, then adding the subsequent components to the heated oil approximately 20 minutes apart under the referenced elevated temperature.
WO 95/19411 (PCT/US95/00424) is directed to additives for lubricants which are combinations and reaction products of metallic dithiocarbamates and metallic dithiophosphates. The preblended combinations and reaction products are described as showing good stability and compatibility when used in the presence of other commonly used additives in grease or lubricant compositions. The metals of the metal dithiophosphates and metal dithiocarbamates may be selected from nickel, antimony, molybdenum, copper, cobalt, iron, cadmium, zinc, manganese, sodium, magnesium, calcium and lead. The combination and reaction products are described as providing enhanced friction reducing and anti-wear properties at extreme pressure. Additional anti-oxidation, cleanliness, anti-fatigue, high temperature stabilizing and anti-corrosion properties are also described as potentially present. The metallic dithiocarbamate and metallic dithiophosphate are mixed, generally at any suitable conditions with temperatures varying from -20° C. to 250° C., preferably between 50° C. and 150° C. Reaction rather than blending will usually occur if the temperature is between 70° C. and 100° C. The metallic dithiocarbamates and the metallic dithiophosphates may be combined in any ratio from 1:9 to 9:1. In the Examples, reaction temperatures of only 80° C. to 100° C. were employed.
U.S. Pat. No. 4,812,246 teaches a lubricating composition comprising a particular base oil and additives comprising a phenol based antioxidant and/or organomolybdenum compounds such as molybdenum dithiocarbamate. The lubricating composition can also contain other common additives such as zinc dialkyl dithiophosphates, etc.
M. Meienberger, et al., Inorganica Chimica Acta 213, p. 157-169 (1993) discloses the reactions of certain (Mo 3 S 7 L 3 ) +4 compounds.
Copending U.S. application Ser. No. 766,828, filed Dec. 13, 1996 discloses a method for making a lube oil composition using a different reaction product, i.e., the reaction product of molybdenum dialkyl dithiocarbamate and metal dihydrocarbyl dithiophosphate. Disadvantageously this reaction forms a metal precipitate which must be separated from the product before use.
Due to environmental concerns and Corporate Average Fuel Economy ("CAFE") requirements, the industry is placing increasing emphasis not only on the initial fuel economy performance of engine oils, but also on the retention of the performance during oil use. Certain molybdenum friction modifiers are known to offer frictional benefits, which, however, degrade as the oil ages (K. Arai et. al., "Lubricant Technology To Enhance The Durability Of Low Friction Performance Of Gasoline Engine Oils", SAE 952533 (1995)). It would be desirable to have an engine oil with improved friction performance and friction retention properties. Applicants' invention addresses these needs.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plot of the radial distribution function centered on the molybdenum atom (in Angstroms), derived from the molybdenum EXAFS spectra of: (A) molybdenum dithiocarbamate; (B) reaction product of molybdenum dithiocarbamate with dialkyldithiophosphoric acid at 150° C. for 16 hours and an air sparge of 55 cc/minute; and (C) Mo 3 S 7 coco (DTC) 4 .
SUMMARY OF THE INVENTION
This invention is a method for forming a lubricating composition comprising adding to a major amount of an oil of lubricating viscosity a minor amount of an additive obtained by the reaction of molybdenum dialkyl dithiocarbamate with dihydrocarbyl dithiophosphoric acid in air at a temperature ranging from above about 135° C. to about 200° C., preferably about 150° C.
In another embodiment, the invention is a method for enhancing the friction reducing properties and extending the friction retention benefits of a lubricating oil composition having a major amount of a lubricating oil and a minor amount of an additive obtained by the reaction of molybdenum dialkyl dithiocarbamate with dihydrocarbyl dithiophosphoric acid in air at a temperature ranging from above about 135° C. to about 200° C., preferably about 150° C.
The present invention may comprise, consist or consist essentially of the elements disclosed therein and may be practiced in the absence of an element not disclosed and includes the products produced by the processes disclosed herein.
DESCRIPTION OF THE INVENTION
The present invention is directed to a multifunctional lube additive formed as the reaction product of a dihydrocarbyl dithiophosphoric acid (as opposed to the metal containing salt) and molybdenum dithiocarbamate in air at a temperature above 135° C. to about 200° C., preferably about 150° C. The invention also relates to a lubricant formulation additive that imparts improved friction retention characteristics to the lubricant in which it is employed compared with the friction retention properties of organo molybdenum dithiocarbamates.
The product is prepared by reacting the dihydrocarbyl dithiophosphoric acid and molybdenum dithiocarbamate at a temperature above about 135° C. to about 200° C., preferably about 150° C. at times sufficient for reaction to occur, preferably for about 8 to 16 hours, with an air sparge sufficient to saturate the mixture with air. Molybdenum compounds typically show enhanced friction retention benefits at increased temperatures.
Advantageously, the reaction product is produced in the absence of any precipitate formation as would be the case when metal dihydrocarbyl dithiophosphates are used.
Any dihydrocarbyl dithiophosphoric acid (non-metal containing) in which the solubilizing ligands are C 3 -C 16 hydrocarbyl ligands, and combinations thereof are usable as starting materials in production of the composition of the present invention. While alkyl ligands are preferred, the invention can also be practiced with ligands having organo groups selected from aryl, substituted aryl, and ether groups. Preferably, the solubilizing ligands are C 3 -C 12 primary, secondary, mixed primary-secondary alkyl ligands, and combinations thereof.
The molybdenum dithiocarbamates (MoDTC) usable as starting materials in production of the composition of the present invention are represented by the structural formula shown below: ##STR1## where R 1 -R 4 are independently selected C 3 -C 16 hydrocarbyl ligands preferably primary, secondary, mixed primary-secondary alkyl ligands, and mixtures thereof. X 1 and X 2 are each, either O or S. While alkyl ligands are preferred, the invention can also be practiced with aryl and alkyl aryl ligands.
In practicing the present invention, the list of usable starting materials is quite broad, being generally defined as dihydrocarbyl dithiophosphoric acids and molybdenum dithiocarbamates, combined in any suitable ratio.
The starting materials are combined and reacted at temperatures of above about 135° C., preferably about 150° C., at times sufficient for reaction to occur, preferably about 8-16 hours at temperatures of about 150° C. with air sparge sufficient to saturate the reaction mixture with air. Advantageously this results in a soluble product without undesirable insoluble metal containing materials. The reaction product will be used in the formulated oil in an amount sufficient to attain the desired molybdenum concentration in the formulated oil and to impart the desired friction characteristics.
Alternatively, the resulting reaction product may be added to a suitable oleaginous carrier in order to form a concentrate for blending with lubricating oils. The amount of reaction product ranges from about 1 to about 100% based on the weight of the carrier and reaction product. Suitable oleaginous carriers include base stock, animal oils, vegetable oils, mineral oil, synthetic oils, and mixtures thereof.
The amount of reaction product, per se, measured as a function of molybdenum wt % active ingredient, in the final formulated oil will range from 0.004 wt % to 0.4 wt %, and preferably from 0.005 wt % to 0.2 wt %.
The lubricating composition according to the invention requires a major amount of lubricating oil basestock. In general, the lubricating oil basestock will have a kinematic viscosity ranging from about 2 to about 1,000 cSt at 40° C. The lubricating oil basestock can be derived from natural lubricating oils, synthetic lubricating oils, or mixtures thereof. Suitable lubricating oil basestocks include basestocks obtained by isomerization of synthetic wax and slack wax, as well as hydrocrackate basestocks produced by hydrocracking (rather than solvent extracting) the aromatic and polar components of the crude.
Natural lubricating oils include animal oils, vegetable oils (e.g., castor oils and lard oil), petroleum oils, mineral oils, and oils derived from coal or shale, and mixtures thereof.
Synthetic oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylated diphenyl ethers, alkylated diphenyl sulfides, as well as their derivatives, analogs, and homologs thereof, and the like. Synthetic lubricating oils also include alkylene oxide polymers, interpolymers, copolymers and derivatives thereof wherein the terminal hydroxyl groups have been modified by esterification, etherification, etc. Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids with a variety of alcohols. Esters useful as synthetic oils also include those made from C 5 to C 12 monocarboxylic aids and polyols and polyol ethers.
Silicon-based oils (such as the polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and silicate oils) comprise another useful class of synthetic lubricating oils. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans, polyalphaolefins, and the like.
The lubricating oil may be derived from unrefined, refined, re-refined oils, or mixtures thereof, Unrefined oils are obtained directly from a natural source or synthetic source (e.g., coal, shale, or tar sands bitumen) without further purification or treatment. Examples of unrefined oils include a shale oil obtained directly from a retorting operation, a petroleum oil obtained directly from distillation, or an ester oil obtained directly from an esterification process, each of which is then used without further treatment. Refined oils are similar to the unrefined oils except that refined oils have been treated in one or more purification steps to improve one or more properties. Suitable purification techniques include distillation, hydrotreating, dewaxing, solvent extraction, acid or base extraction, filtration, and percolation, all of which are known to those skilled in the art. Rerefined oils are obtained by treating refined oils in processes similar to those used to obtain the refined oils. These rerefined oils are also known as reclaimed or reprocessed oils and often are additionally processed by techniques for removal of spent additives and oil breakdown products.
The lubricating oil formulation containing the reaction product is compatible with and may also contain one or more of the following classes of additives: viscosity index improvers, antioxidants, friction modifiers, anti-foamants, anti-wear agents, corrosion inhibitors, hydrolytic stabilizers, metal deactivator, detergents, dispersants, pour point depressants, extreme pressure additives, etc. These can be combined in proportions known in the art.
This invention may be further understood by reference to, but not limited by, the following examples which include preferred embodiments.
GENERAL
"Coco" is an alkyl chain or mixture of chains of varying even numbers of carbon atoms of from about typically C 8 to C 18 . "DTC" means dialkyldithiocarbamate. "MoDTC" means molybdenum dithiocarbamate. "DDPA" means dialkyl dithiophosphoric acid.
EXAMPLE 1
One method of preparation of the compound is by the reaction of commercial molybdenum dithiocarbamate (MoDTC) with dihydrocarbyl dithiophosphoric acid in a batch reactor at 150° C. with an air purge of 55 cc/min for 16 hours. In our example, the MoDTC material was Sakura Lube 155 available from Asahi Denka Kogyo and the dihydrocarbyl dithiophosphoric acid (DDPA) was 2-ethylhexyl dithiophosphoric acid. Sakura Lube 155 contains 4.5% w/w Mo. The starting reactants were used at 20 grams of Sakura Lube 155 and 9.162 grams of 2-ethylhexyl dithiophosphoric acid. The reaction product was then dialyzed through a latex membrane and the retained phase was used.
The reaction product was identified by its spectroscopic signature. FIG. 1 is a radial distribution function (RDF) centered on the molybdenum atom, derived from the molybdenum EXAFS spectra. Comparing the molybdenum RDF of the molybdenum dithiocarbamate starting material (A) with the spectrum (B) of the reaction product of molybdenum dithiocarbamate with dialkyl dithiophosphoric acid at 150° C. for 16 hours in air, it is clear that the RDF is changed in (B), indicating a change in the chemical coordination of the molybdenum atom. Spectrum C is the RDF of Mo 3 S 7 coco(DTC) 4 and is also plotted for comparison.
6.10 grams of the reaction product of MoDTC with DDPA were added to 350 grams of a formulated engine oil without friction modifier. The concentration of Mo as measured by inductively coupled plasma (ICP) was 432 wppm in the formulated engine oil. This oil was in turn subjected to a nitration test. In this test, 250 grams of oil are heated at 150° C. and exposed to 1% NO 2 in air gas flow through sparger tubes. The gas flow rate is 60 mL/min. Similar tests have been disclosed in the literature by K. Arai et al, SAE 952533 (1995) and M. D. Johnson et al., SAE 952532, (1995). This bench test is used to simulate the degradation of engine oils, and MoDTC in particular. Degradation of MoDTC is known to happen in engine and vehicle tests resulting in loss of frictional performance.
Oil samples of approximately 12 grams were removed at regular time intervals from the nitration rig and subjected to tribological testing in the Cameron-Plint. This is a ball-on-plate tribometer measuring friction coefficients ("fc") under 5 kg load, 21 Hz, and 5 mm stroke. The friction coefficient results are summarized in Table 1.
A similar sample was prepared by dissolving 3.5 grams of the commercial molybdenum dithiocarbamate (MoDTC) Sakura Lube 155 in 350 grams of the same starting engine oil. The concentration of Mo as measured by ICP was 417 wppm in the formulated engine oil. This oil was subjected to the same nitration and friction testing as the oil with the reaction product of MoDTC with dialkyldithio phosphoric acid described above. The friction coefficient results are summarized in Table 2.
Comparing the data in Tables 1 and 2, the oil containing the reaction product of MoDTC with dialkyldithiophosphoric acid retained low friction coefficients at high temperatures for longer period of time of exposure in the nitration rig compared with the oil which contained the commercial MoDTC material. Specifically, the friction coefficient of the reaction product of MoDTC and DDPA at 135° C. increased after 16 hours of aging in the NO x rig compared with 8 hours of aging of the oil containing MoDTC alone.
TABLE 1______________________________________Friction coefficients of a fully formulated engine oilcontaining the reaction product of MoDTC and DDPA in Example 1. Theoil was aged in a NO.sub.x bench test at the times indicated andfrictioncoefficients were measured in the Cameron-Plint ball-on-platetribometer.Time of NO.sub.x fc @ fc @Aging (hrs) fc @ 48° C. fc @ 70° C. 108° C. 135° C.______________________________________0 0.065 0.12 0.114 0.1022 0.047 0.044 0.046 0.0584 0.05 0.041 0.045 0.0456 0.1 0.07 0.045 0.0488 0.11 0.1 0.045 0.04712 0.117 0.12 0.113 0.03916 0.118 0.124 0.11 0.078______________________________________
TABLE 2______________________________________Friction coefficients of a fully formulated engine oilcontaining MoDTC. The oil was aged in a NO.sub.x bench test at the timesindicated and friction were measured in the Cameron-Plintball-on-plate tribometer.Time of NO.sub.x fc @ fc @Aging (hrs) fc @ 48° C. fc @ 70° C. 108° C. 135° C.______________________________________0 0.055 0.044 0.086 0.0642 0.047 0.045 0.04 0.044 0.055 0.036 0.036 0.0366 0.112 0.115 0.116 0.0458 0.108 0.1 0.118 0.11512 0.118 0.122 0.124 0.12316 0.119 0.124 0.124 0.12______________________________________
EXAMPLE 2
In another method of preparation, 104.165 grams of MoDTC additive and 46.618 grams of 2-ethylhexyl dithiophosphoric acid were added in a batch reactor and the reaction took place at 150° C. with an air purge of 55 cc/min for 10 hours. The MoDTC material was Sakura Lube 155 available from Asahi Denka Kogyo and the dihydrocarbyl dithiophosphoric acid (DDPA) was 2-ethylhexyl dithiophosphoric acid. The reaction product was used without dialysis separation.
4.857 grams of the reaction product of MoDTC with DDPA were added to 295.314 grams of a fully formulated engine oil (without friction modifier), the same formulation used in Example 1. This oil was in turn subjected to the same nitration test described in Example 1. Oil samples of approximately 12 grams were removed at regular time intervals from the nitration rig and subjected to tribological testing in the Cameron-Plint, as described in Example 1. The friction coefficient results are summarized in Table 3. Friction retention was achieved up to 16 hours of aging in the NO x rig.
A similar sample was prepared by dissolving the unreacted admixture of MoDTC and DDPA to the fully formulated oil mentioned earlier. 4.849 grams of this unreacted admixture were added to 295.146 grams of the engine oil. This oil was then subjected to the same nitration and friction testing described in Example 1. The friction coefficient results are summarized in Table 4.
Comparing the data in Tables 3 and 4, the oil containing the reaction product of MoDTC with dialkyldithio phosphoric acid retained low friction coefficients for longer period of time of exposure in the nitration rig compared with the oil which contained the unreacted admixture of MoDTC and DDPA.
TABLE 3______________________________________Friction coefficients of a fully formulated engine oilcontaining the reaction product of MoDTC and DDPA in Example 2. Theoil was aged in a NO.sub.x bench test at the times indicated and frictioncoeffi-cients were measured in the Cameron-Plint ball-on-plate tribometer.Time of NO.sub.x fc @ fc @Aging (hrs) fc @ 48° C. fc @ 70° C. 108° C. 135° C.______________________________________0 0.054 0.059 0.074 0.1042 0.039 0.042 0.046 0.0524 0.045 0.045 0.046 0.056 0.048 0.041 0.043 0.0458 0.099 0.074 0.048 0.05712 0.118 0.106 0.112 0.05116 0.115 0.118 0.118 0.11120 0.116 0.117 0.119 0.12424 0.113 0.114 0.114 0.118______________________________________
TABLE 4______________________________________Friction coefficients of a fully formulated engine oilcontaining the unreacted admixture of MoDTC and DDPA. The oil wasaged in a NO.sub.x bench test at the times indicated and frictioncoefficientswere measured in the Cameron-Plint ball-on-plate tribometer.Time of NO.sub.x fc @ fc @Aging (hrs) fc @ 48° C. fc @ 70° C. 108° C. 135° C.______________________________________0 0.041 0.055 0.064 0.0562 0.044 0.039 0.043 0.054 0.042 0.039 0.036 0.0346 0.096 0.074 0.037 0.0368 0.111 0.109 0.093 0.03112 0.118 0.114 0.124 0.11416 0.116 0.117 0.117 0.127______________________________________
EXAMPLE 3
In another method of preparation, 104.165 grams of MoDTC additive and 46.618 grams of 2-ethylhexyl dithiophosphoric acid were added in a batch reactor and the reaction took place at 150° C. with an air purge of 55 cc/min for 16 hours. The MoDTC material was Sakura Lube 155 available from Asahi Denka Kogyo and the dihydrocarbyl dithiophosphoric acid (DDPA) was 2-ethylhexyl dithiophosphoric acid. The reaction product was used without dialysis separation.
4.861 grams of the reaction product of MoDTC with DDPA were added to 295.189 grams of a fully formulated engine oil (without friction modifier), same formulation used in Example 1. This oil was in turn subjected to the same nitration test described in Example 1. Oil samples of approximately 12 grams were removed at regular time intervals from the nitration rig and subjected to tribological testing in the Cameron-Plint, as described in Example 1. The friction coefficient results are summarized in Table 5. Friction retention was achieved up to 16 hours of aging in the NO x rig, similar with the results of the product after 10 hours of reaction (Example 2).
TABLE 5______________________________________Friction coefficients of a fully formulated engine oilcontaining the reaction product of MoDTC and DDPA in Example 2. Theoil was aged in a NO.sub.x bench test at the times indicated andfrictioncoefficients were measured in the Cameron-Plint ball-on-platetribometer.Time of NO.sub.x fc @ fc @Aging (hrs) fc @ 48° C. fc @ 70° C. 108° C. 135° C.______________________________________0 0.065 0.07 0.083 0.0832 0.067 0.07 0.077 0.0764 0.04 0.041 0.045 0.0496 0.05 0.043 0.047 0.0478 0.064 0.059 0.047 0.04512 0.116 0.108 0.11 0.04316 0.114 0.117 0.122 0.1220 0.112 0.117 0.12 0.12324 0.101 0.116 0.124 0.113______________________________________ | Multifunctional molybdenum compounds, which are the reactive product of molybdenum dithiocarbamates and (non-metal containing) dihydrocarbyl dithiophosphoric acids, and the oils that contain them are new compositions which are useful as lubricant additives. They impart to the lubricant formulations to which they are added low friction and excellent friction retention properties. | 2 |
[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S. provisional application Ser. No. 60/626,261, filed Nov. 8, 2004 and entitled “Foam Cleaning and Brightening Composition”. The entire disclosure of 60/626,261 is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a cleaning composition and methods of making the composition, and methods of using the composition to clean surfaces, particularly metal surfaces.
BACKGROUND
[0003] There is a desire in today's market, particularly the automobile market, to be able to obtain clean and bright metal surfaces. This is particularly desired for automobile and other vehicle wheels, where aluminum wheels are very common. Various metal cleaners are commercially available for cleaning and polishing of aluminum wheels, however many of these have flaws. For example, some do not provide adequate levels of cleaning, some do not provide an adequately brightened aluminum surface, some may damage or mar the metal surface, and some may be hazardous to the user's health after prolonged exposure. Wheel cleaners containing HF (hydrofluoric acid), oxalic acid or phosphates are common, but have at least one of these deficiencies.
[0004] A better metal cleaner is desired, especially one for cleaning and brightening aluminum surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of a foam dispenser suitable for use with the composition of the invention.
[0006] FIG. 2 is a perspective view of a foam dispenser suitable for use with the composition of the invention.
[0007] FIG. 3 is a photograph of the foam composition of the invention being applied via foam dispenser to an automobile wheel.
[0008] FIG. 4 is a photograph of an automobile wheel after one half has been cleaned with the foam composition of the invention.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to a composition, particularly a cleaning composition. The cleaning composition includes an acid package and at least one surfactant. When used on metal surfaces, the acid package provide brightening and the surfactant provides cleaning.
[0010] The acid package includes a bisulfate and an inorganic salt, the inorganic salt being acidic or neutral pH when by itself. The inorganic salt provides buffering to the bisulfate. Typically, the bisulfate and salts are metal bisulfates and inorganic metal salts. Suitable inorganic salts for the acid package include chloride, phosphate, carbonate, and sulfate, including sodium chloride, potassium phosphate, calcium carbonate, and magnesium sulfate. A preferred acid package includes bisulfate and sulfate salts, such as sodium bisulfate and sodium sulfate.
[0011] The surfactant can include anionic surfactants, cationic surfactants, nonionic surfactants, and zwitterionic or amphoteric surfactants. A preferred class of anionic surfactant to use is sulfonates, such as alkyl sulfonates and aryl sulfonates. One preferred cationic surfactant to use is a quaternary ammonium compound.
[0012] In a preferred embodiment, the present invention is a composition that is a one-step wheel cleaner/brightener, and the invention includes methods of dispensing and using the composition. The composition of the invention contains no HF, no bifluoride, no oxalic acid, or other poisonous and highly toxic materials commonly found in both industrial and consumer wheel cleaners. Further, the wheel cleaner/brightener composition matches or exceeds the performance of those hazardous formulations and does not damage aluminum wheels even when applied to hot metal. Additionally, the composition has the added benefit of providing a one-step metal cleaning and brightening, especially aluminum.
[0013] The composition can be a foam composition, provided in a foam dispenser. The foam dispenser includes a container and a mechanical foaming head. The container includes a cleaning composition containing a metal bisulfate and inorganic metal salt acid package, and at least one surfactant, water, and a foam-boosting solvent. Glycol ether is a preferred foam-boosting solvent.
[0014] A method for foaming a cleaning composition is provided according to the invention. The method includes steps of mixing a cleaning composition and air in a mechanical foaming head to provide mixing of the cleaning composition and air to generate a foam.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention is a cleaning composition and methods of making the composition, and methods of using the composition to clean surfaces, particularly metal surfaces. Aluminum is one exemplary metal that can be cleaned and brightened with the composition. The cleaning composition is provided so that it foams as a result of processing through a mechanical foaming head as a result of combining the cleaning composition with air without the use of an aerosol propellant.
[0016] The composition can be referred to as a cleaning composition or a detergent composition and can be provided in the form of a concentrated composition, a ready-to-use composition, and/or a use composition. The phrase “cleaning composition” refers to a composition that provides for the removal of a substance from a surface to be cleaned. Exemplary substances that can be removed by the cleaning composition include general materials such as soil, dirt, oil and grease, and more specific materials such as road grime, road salt, brake dust, and other common materials.
[0017] The cleaning composition of the present invention can be used to clean vehicle components. Materials such as road grime, road salt and brake dust are commonly found on automobile wheels and rims, but are also found on other vehicles and vehicle surfaces, such as trailers, campers, semi-trucks, airplanes, and the like. The cleaning composition of the present invention can additionally or alternatively be used on small scale-surfaces such as countertops, cabinetry, appliances, and other institutional or industrial surface applications, or large-scale surfaces such as storage tanks, reaction tanks, process equipment such as fermentors, and other such institutional or industrial surface applications.
[0018] The concentrated composition can be referred to as a concentrate, and can be diluted to provide the ready-to-use composition and/or the use composition. The concentrate can be diluted in a single dilution or in stages to provide the ready-to-use composition and/or the use composition. Providing the cleaning composition as a concentrate for subsequent dilution can be advantageous when it is desirable to package and ship the concentrate instead of the ready-to-use cleaning composition and/or the use composition. The ready-to-use composition can be made available as a use composition when the ready-to-use composition is intended to be applied directly to a surface to provide cleaning. For example, a wheel cleaner can be referred to as a ready-to-use composition when it is intended to be applied directly to a wheel surface for cleaning.
[0019] Cleaning Composition
[0020] The composition of the invention, in its most simple form, may be generally described as a mixture of an acid package of inorganic bisulfate and an inorganic salt, and surfactant, the inorganic salt having an acidic or neutral pH when by itself. That is, the inorganic salt has a pH that is in the range of 1-7, preferably about 1-6, although in some embodiments inorganic salts having a pH of 1-8 may be suitable. In many embodiments, the acid package is an inorganic bisulfate salt and an inorganic bisulfate salt.
[0021] Acid Package
[0022] The bisulfate/salt combination provides system that, in equilibrium, readily maintains an acidic pH of about 1-7. By maintaining that range of pH, the bisulfate retains its identity as the hydrogen sulfate anion, HSO 4 − , and minimizes formation of sulfuric acid. In some embodiments, a pH range of about 3-5, or even 2-4, is desired. A generic equation for the acid package equilibrium is provided below:
M m H n A=M m+n A
[0023] An example equilibrium system, using sodium bisulfate and sodium sulfate, is provided below.
2NaHSO 4 =Na 2 SO 4 +H 2 SO 4
[0024] Bisulfate, in the presence of water, has a tendency to create sulfate and sulfuric acid; sulfuric acid is generally undesirable when cleaning and/or polishing surfaces. By providing the sulfate or other inorganic salt, the equilibrium is pushed back toward the bisulfate form, thus reducing or inhibiting the formation of sulfuric acid. The inorganic salt should be present in the acid package at a level sufficient to inhibit or reduce the formation of sulfuric acid, as compared to having no inorganic salt present.
[0025] It is desired to reduce, inhibit, and otherwise minimize the presence of sulfuric acid in the cleaning composition, as sulfuric acid has the potential to, and usually does, damage the surface of metal, particularly aluminum. The damage observed is typically pitting of the metal, which not only is visually undesirable, but may weaken the metal structure.
[0026] The bisulfate and inorganic salts used to form the cleaning composition may have any inorganic cation or mixtures of cations, however, those from groups IA and IIA, as well as an ammonium cation, are preferred. Potassium and sodium cations are especially preferred.
[0027] In the composition, the bisulfate and inorganic salt will go to their equilibrium state, based on the acidity of the composition. A bisulfate/sulfate combination provides a system that, in equilibrium, readily maintains an acidic pH of 2-3.
[0028] The amount of starting or initial bisulfate and salt is broad. The final ratio of bisulfate to salt is dependent on the pH of the overall composition, which can be adjusted by various additives. The inorganic salt is present at a level to inhibit formation of sulfuric acid, when the composition is in contact with water. Generally, the weight ratio of bisulfate to inorganic salt, as raw materials or initial ingredients, is about 1/100 to 100/1. Preferably, the weight ratio of bisulfate to inorganic salt is about 1/25 to 25/1, more preferably from 1/10 to 10/1. Other ranges of bisulfate to inorganic salt are also suitable, such as weight ratios of 1/5 to 5/1, 1/3 to 3/1, 1/2 to 2/1, and about 1/1. Suitable and preferred ranges of bisulfate to sulfate include 1/5 to 5/1, 1/3 to 3/1, 1/2 to 2/1, and about 1/1. The bisulfate and inorganic salt, both individually and as a combination, are present at a level sufficient to provide a brightening affect when applied to a metal surface. A “brightening affect” is one that, with the naked human eye, is noticed to be brighter than prior to the treatment.
[0029] Sulfate salt is a preferred inorganic salt to use with the bisulfate, although other salts, including chloride, phosphate, carbonate can be used.
[0030] Various other acidic materials may be added to the bisulfate/salt acid package, however, these other materials preferably provide no noticeable cleaning affect due to that material. That is, the cleaning effect is provided by the bisulfate/salt acid package, for example, the bisulfate/sulfate package. A noticeable cleaning affect is when materials such as soil, dirt, oil and grease, road grime, road salt, or brake dust are removed from a surface at a level where a naked human eye can notice a different is shine and/or reflectance of the surface. In general, at least about 20% of the material is removed from the surface in order to have a noticeable cleaning affect. In many situations, at least about 50% of the material is removed from the surface in order to have a noticeable cleaning affect.
[0031] To provide noticeable cleaning affect, most materials need to be present at a level of at least about 10 wt-% of the acid package, although, depending on the materials, levels of about 5% or 3% or 2% may provide a noticeable cleaning affect. Thus, any non-bisulfate/salt materials, if present, are present at a level that provides no noticeable cleaning affect.
[0032] The presence of sulfites in either the acid package or composition should be avoided, and in various embodiments, sulfites can be excluded. Sulfites can have a tendency to react with the bisulfate, producing undesirable materials. If any sulfite is present, it should be at a level of no more than about 10% of the acid package, preferably no more than about 1% of the acid package, for example, no more than about 0.1%. The avoidance to sulfites inhibits the formation of sulfuric acid. Other materials to be preferably avoided and which can be excluded include hydrofluoric acid, bifluorides, and oxalic acid.
[0033] Surfactant
[0034] Surfactant, typically more than one surfactant, is present in the composition. Exemplary types of surfactants that can be included include anionic surfactants, cationic surfactants, nonionic surfactants, and zwitterionic or amphoteric surfactants.
[0035] The anionic surfactant component can include a detersive amount of an anionic surfactant or a mixture of anionic surfactants. Anionic surfactants are often desirable in cleaning compositions because of their wetting and detersive properties, which facilitate the removal of inorganic soils such as road dust. The anionic surfactants that can be used include any anionic surfactant available in the cleaning industry. Exemplary groups of anionic surfactants include carboxylates, isethionates, sulfonates, sulfates, their polymers or copolymers and mixtures thereof. Exemplary surfactants that can be provided in the anionic surfactant component include alkyl aryl sulfonates, secondary alkane sulfonates, alkyl methyl ester sulfonates, alpha olefin sulfonates, alkyl ether sulfates, alkyl sulfates, and alcohol sulfates. Sulfonates are a preferred type of anionic surfactant with primary and secondary alkane sulfonates, olefin sulfonates, and aryl sulfonates preferred.
[0036] Exemplary alkyl aryl sulfonates that can be used in the cleaning composition can have an alkyl group that contains 6 to 24 carbon atoms and the aryl group can be at least one of benzene, toluene, and xylene. An exemplary alkyl aryl sulfonate includes linear alkyl benzene sulfonate. An exemplary linear alkyl benzene sulfonate includes linear dodecyl benzyl sulfonate that can be provided as an acid that is neutralized to form the sulfonate. Additional exemplary alkyl aryl sulfonates include xylene sulfonate and cumene sulfonate.
[0037] Exemplary alkane sulfonates that can be used in the cleaning composition can have an alkane group having 6 to 24 carbon atoms. Exemplary alkane sulfonates that can be used include secondary alkane sulfonates. An exemplary secondary alkane sulfonate includes sodium C 14 -C 17 secondary alkyl sulfonate commercially available as Hostapur SAS from Clariant.
[0038] Exemplary alkyl methyl ester sulfonates that can be used in the cleaning composition include those having an alkyl group containing 6 to 24 carbon atoms.
[0039] Exemplary alpha olefin sulfonates that can be used in the cleaning composition include those having alpha olefin groups containing 6 to 24 carbon atoms.
[0040] Exemplary alkyl ether sulfates that can be used in the cleaning composition include those having between about 1 and about 10 repeating alkoxy groups, between about 1 and about 5 repeating alkoxy groups. In general, the alkoxy group will contain between about 2 and about 4 carbon atoms. An exemplary alkoxy group is ethoxy. An exemplary alkyl ether sulfate is sodium lauryl ether ethoxylate sulfate and is available under the name Steol CS-460.
[0041] Exemplary alkyl sulfates that can be used in the cleaning composition include those having an alkyl group containing 6 to 24 carbon atoms. Exemplary alkyl sulfates include sodium lauryl sulfate and sodium lauryl/myristyl sulfate.
[0042] Suitable cationic surfactants may include quaternary ammonium compounds, amine acid salts, quaternary phosphonium compounds, quaternary sulfonium compounds, their polymers or copolymers, and mixtures thereof. Quaternary ammonium compounds and amine acid salts are preferred cationic surfactants, and are particularly suitable as a penetrant for road grime. Alkoxylated quaternary ammonium compounds are especially preferred.
[0043] Exemplary cationic surfactants that can be used include quaternary ammonium compounds and amine salts including those having the following formula:
wherein R 1 , R 2 , R 3 , and R 4 can, independently of each other, be hydrogen, C 1 -C 24 branched, linear, alkyl, aryl, or aralkyl groups, and X can be an anion such as a halide, methosulfate, ethosulfate, carbonate, phosphate, sulfate, etc. A particularly preferred quaternary ammonium compound is commercially available as “Variquat CC-42NS” from Goldschmidt, which was found to be particularly suitable for acidic conditions.
[0044] Suitable nonionic surfactants may include aliphatic, aryl, or aryalkyl alkoxylates; EO-PO copolymers; alkoxylated amines or carboxylates; amides; polyglycosides and their derivatives, their polymers or copolymers, and mixtures thereof. Alcohol ethoxylates, EO-PO copolymers, and EO-PO derivatives of ethylenediamine are preferred nonionic surfactants.
[0045] Exemplary nonionic surfactants include alcohol alkoxylates, ethylene oxide-propylene oxide copolymers, alkyl polyglycosides, alkanolamides, and mixtures thereof. Exemplary alcohol alkoxylates include alcohol ethoxylates, alcohol propoxylates, alkyl phenol ethoxylate-propoxylates, and mixtures thereof.
[0046] Exemplary nonionic block copolymer surfactants include polyoxyethylene-polyoxypropylene (EO-PO) block copolymers. Exemplary polyoxyethylene-polyoxypropylene block copolymers that can be used have the formulae:
(EO) x (PO) y (EO) x
(PO) y (EO) x (PO) y
(PO) y (EO) x (PO) y (EO) x (PO) y
wherein EO represents an ethylene oxide group, PO represents a propylene oxide group, and x and y reflect the average molecular proportion of each alkylene oxide monomer in the overall block copolymer composition. Preferably, x is from about 10 to about 130, y is about 15 to about 70, and x plus y is about 25 to about 200. It should be understood that each x and y in a molecule can be different. The total polyoxyethylene component of the block copolymer is preferably at least about 20 mol-% of the block copolymer and more preferably at least about 30 mol-% of the block copolymer. The material preferably has a molecular weight greater than about 1,500 and more preferably greater than about 2,000. Although the exemplary polyoxyethylene-polyoxypropylene block copolymer structures provided above have 3 blocks and 5 blocks, it should be appreciated that the nonionic block copolymer surfactants can include more or less than 3 and 5 blocks. In addition, the nonionic block copolymer surfactants can include additional repeating units such as butylene oxide repeating units. Furthermore, the nonionic block copolymer surfactants that can be used can be characterized heteric polyoxyethylene-polyoxypropylene block copolymers. Exemplary materials are available from BASF under the name Pluronic, and an exemplary EO-PO co-polymer that can be used is available under the name Pluronic N3. EO-PO co-polymers provide good sheeting action on the surface being cleaned.
[0047] Alcohol alkoxylate surfactants that can be used according to the invention can have the formula:
R(AO) x -X
wherein R is an alkyl group containing 6 to 24 carbon atoms, AO is an alkylene oxide group containing 2 to 12 carbon atoms, x is 1 to 20, and X is hydrogen or an alkyl or aryl group containing 1-12 carbon atoms. The alkylene oxide group is preferably ethylene oxide, propylene oxide, butylene oxide, or mixture thereof. In addition, the alkylene oxide group can include a decylene oxide group as a cap.
[0048] Alkyl polyglycoside surfactants can have the formula:
(G) x -O—R
wherein G is a moiety derived from reducing saccharide containing 5 or 6 carbon atoms, e.g., pentose or hexose, R is a fatty aliphatic group containing 6 to 24 carbon atoms, and x is the degree of polymerization (DP) of the polyglycoside representing the number of monosaccharide repeating units in the polyglycoside. The value of x can be between about 0.5 and about 10. R can contain 10-16 carbon atoms and x can be 0.5 to 3.
[0049] Alkanolamides that can be used as nonionic surfactants include alkanolamides having the following formula:
wherein R 1 is C 6 -C 20 alkyl group, R 2 is hydrogen or a C 1 -C 3 , and R 3 is hydrogen or a C 1 -C 3 alkyl group. An exemplary alkanolamide is available as cocodiethanolamide.
[0050] The zwitterionic surfactants that can be used include β-N-alkylaminopropionates, N-alkyl-β-iminodipropionates, imidazoline carboxylates, N-alkylbetaines, sulfobetaines, sultaines, amine oxides and polybetaine polysiloxanes. Exemplary polybetaine polysiloxanes have the formula:
n is 1 to 100 and m is 0 to 100, preferably 1 to 100. Preferred polybetaine polysiloxanes are available under the name ABIL® from Goldschmidt Chemical Corp. Preferred amine oxides that can be used include alkyl dimethyl amine oxides containing alkyl groups containing 6 to 24 carbon atoms. An exemplary amine oxide is lauryl dimethylamine oxide.
[0051] Exemplary amphoteric surfactants include betaines, amine oxides, sultaines, amphoacetates, imidazoline derivatives, and mixtures thereof.
[0052] The total amount of surfactant in the composition, for a concentrate composition, is generally about 0.01 to 50 wt. %, typically about 0.1 to 35 wt. %. The total amount of surfactant in a ready-to-use composition is generally about 0.001 to 35 wt. %, typically about 0.01 to 20 wt. %. Generally, more than one surfactant is present in the composition.
[0053] The ratio of surfactant to combined bisulfate (initially added) and inorganic salt would be from about 1/100 to 100/1; a preferred ratio from about 1/25 to 25/1; more preferred from about 1/10 to 10/1; an especially preferred ratio is from about 2/1 to 1/2.
[0054] Foamed Cleaning Composition
[0055] The cleaning composition according to the invention can be foamed and applied to a surface. In general, it is expected that the cleaning composition will provide cleaning in environments where application of a foam to a surface is advantageous. An exemplary environment where application of a foam to a surface is advantageous is where the foam provides for increasing contact time between the cleaning composition and the surface to be cleaned. By providing the cleaning composition in the form of a foam, the tendency of the cleaning composition to run or level when applied to a surface can be reduced. When cleaning a non-horizontal surface (such as a vertical surface), providing the cleaning composition in the form of a foam can enhance cling that allows the foam cleaning composition to remain in place and resist running off or down the non-horizontal surface as a result of gravity. Exemplary non-horizontal surfaces that are often cleaned include wheel hubs and rims, walls, doors, and other vertical surfaces. In the case of horizontal surfaces, the foam cleaning composition can resist leveling. This is advantageous in a situation, such as, cleaning a floor where it is desirable to have the foam cleaning composition remain in a specific location on the floor without seeping across the floor and/or under a door.
[0056] When the cleaning composition is provided as a foam, the composition has a cellular structure that can be characterized as having several layers of air cells that provide the composition with a foamy appearance. It should be understood that the characterization of a foam refers to the existence of more than simply a few air bubbles. In general, a foam can be characterized as having at least 50 wt. % foam using a 15 second vertical separation test. The test is carried out by spraying the cleaning composition as a foam onto a vertical surface such as aluminum, waiting 15 seconds after application of the foam to the vertical surface, and then taking up the liquid portion and the foam portion in separate preweighed paper towels. The weight of the absorbed liquid can be calculated and the weight of the absorbed foam can be calculated. By providing a separation time of at least 15 seconds, it is believed that a reasonable amount of separation of liquid and foam can be achieved. The towel picking up the liquid portion should not pick up any of the foam portion, and the towel picking up the foam portion should not pick up the liquid portion that has fallen below the foam portion. It is understood that the foam portion may still include a small amount of associated liquid. However, this associated liquid is considered a part of the foam as long as it remains with the foam at the 15 second cut off time. The weight percent foam can be calculated by dividing the weight of the foam component by the total weight and multiplying by 100. The 15 second vertical separation test can be referred to as a “gravimetric foam test after 15 seconds.” The cleaning composition preferably provides at least 70 wt. % foam according to the gravimetric foam test after 15 seconds, more preferably at least about 75 wt. % foam, and even more preferably at least about 90 wt. % foam. In general, it is desirable to have the foam hang up and not fall down a vertical surface to provide desired contact time and to allow a person sufficient time to work the foam at its intended location. The period of 15 seconds is selected for the test because it is expected that a foam will likely “hang” for at least about 15 seconds and any free liquid, if present at all, will have an opportunity to separate from the foam and fall down the vertical surface. In addition, the foam persists for at least about 15 seconds after application to a surface. This means that the foam will have a tendency to remain as a foam and will resist condensing to a liquid in order to provide the above-identified weight percent foam. More preferably, the foam persists for at least about 1 minute after application to the surface.
[0057] The cleaning composition can be formulated for various types of cleaning applications where delivery as a foam is advantageous. Exemplary applications where delivery as a foam is advantageous include hard surface cleaning compositions, detergents, wheel cleaners, tire dressings, and polishes. When used as a hard surface cleaner, the composition can be applied to stainless steel, aluminum, copper, vinyl, plastic, metal, glass, rubber (natural and synthetic), formica, wood, mild steel, melamine, brass, ceramic, stone, etc. When applied to aluminum, the composition also brightens the aluminum surface, by removing oxidation. When the composition is provided as a cleaner, it can be applied to appliances and other devices such as refrigerators, stoves, dishwashers, elevators, doors, faucets, countertops, sinks, etc.
[0058] The composition according to the invention can be foamed without the use of a propellant, and applied as a foam directly to a surface. A solvent can assist in the generation of a foam when the composition is processed through a mechanical foaming head. The solvents that assist in the generation of a foam can be referred to as “foam-boosting solvents.” Mechanical foaming heads that can be used to provide foam generation include those heads that cause air and the cleaning composition to mix and create a foamed composition. That is, the mechanical foaming head causes air and the cleaning composition to mix in a mixing chamber and then pass through an opening to create a foam.
[0059] The cleaning composition according to the invention can be foamed without the use of a propellant normally associated with aerosol compositions. In general, aerosol compositions include a pressurized container for storing a composition and a propellant. The expansion of the propellant in the composition and propellant mixture as it passes through a nozzle causes the cleaning composition to become foamed. A mechanical foaming head, in contrast, relies upon air from the environment and causes the air to mix with the liquid composition to become foamed. While it is understood that operating the mechanical foaming head may result in a compression of the air within the mixing chamber, it is pointed out that the container that stores the cleaning composition is not considered pressurized even though the pressure inside the container may be slightly higher or lower than ambient pressure at times.
[0060] Propellants that are often used in aerosols include liquids that form gases when expanded to atmospheric pressure. Exemplary propellants commonly used in aerosols include fluorocarbons, chlorofluorocarbons, and alkanes such as butane, ethane, isobutane, and propane. Propellants in general and these propellants in particular can be excluded from the cleaning composition according to the invention or they can be limited to an amount, if any are present, that is insufficient to provide foaming of the composition as a result of pressure drop (such as through an aerosol nozzle) so that the composition contains at least 50 wt. % foam according to a 15 second vertical separation test. Air has a tendency not to compress to a liquid under conditions normally encountered in conventional aerosol devices. Air is not considered a propellant according to the present invention even though it may be slightly compressed using the mechanical foaming head according to the invention. The term “propellant” as used herein should be understood to not refer to air and can be characterized as non-air containing propellants. The foam according to the invention can be characterized as having been formed by air rather than by a propellant. Because propellants are typically provided in a liquid form in combination with a liquid to be foamed, and form bubbles in the liquid as the propellant vaporizes as pressure drops, it is expected that the foam that is foamed by a propellant will contain residual propellant. It is believed that the residual propellant can be measured by a gas chromatographic head space analysis. It is expected that foams produced using a propellant will exhibit a concentration of propellant in the foam of greater than 1 ppm. Accordingly, the foam according to the invention includes less than 1 ppm propellant as measured by a gas chromatographic head space analysis. Preferably, the foam according to the invention has no propellant. That is, the foam can be produced using air and need not be produced using a propellant.
[0061] Because the foam according to the invention can be prepared without a propellant, the container that holds the liquid cleaning composition can be constructed so that that it is capable of holding the cleaning composition under substantially atmospheric conditions both inside and outside the container. Because propellants are not used, the container need not be a container capable of withstanding the pressures normally associated with aerosol containers. Accordingly, the container can be provided from a plastic or polymer material rather than from a metallic material normally associated with aerosol containers.
[0062] Exemplary mechanical foaming heads that can be used include those available from Airspray International, Inc. of Pompano Beach, Fla., and from Zeller Plastik, a division of Crown Cork and Seal Co. Exemplary mechanical foaming heads that can be used according to the invention are described in, for example, U.S. Pat. No. D-452,822; U.S. Pat. No. D-452,653; U.S. Pat. No. D-456,260; and U.S. Pat. No. 6,053,364. Mechanical foaming heads that can be used according to the invention includes those heads that are actuated or intended to be actuated by application of finger pressure to a trigger that causes the cleaning composition and air to mix and create a foam. That is, a person's finger pressure can cause the trigger to depress thereby drawing the cleaning composition and air into the head and causing the cleaning composition and air to mix and create a foam.
[0063] Now referring to FIG. 1 , a first foam dispenser is shown at reference number 10 . Foam dispenser 10 includes a container 12 holding a liquid cleaning composition 14 , and a mechanical foaming head 16 attached to container 12 . Volume of container 12 not occupied by liquid composition 14 is referred to as air headspace 28 . Mechanical foaming head 16 includes a liquid inlet line 18 that draws liquid cleaning composition 14 into mechanical foaming head 16 . In addition, an air inlet 20 draws air into mechanical foaming head 16 . Air inlet 20 for foam dispenser 10 is provided within container 12 . That is, air 22 located within container 12 is drawn in through air inlet 20 . It is understood that mechanical foaming head 16 provides for venting of air 22 . The air 22 from air inlet 20 and liquid cleaning composition 14 from liquid inlet line 18 combine in a mixing chamber 24 and then are forced through an outlet 26 to outside of the foam dispenser 10 . The resulting foam can be applied to various surfaces. Mixing chamber 24 and outlet 26 can be considered a part of mechanical foaming head 16 .
[0064] Foam dispenser 10 can be operated by depressing a trigger 30 using, for example, finger pressure or finger actuation. The operator can press trigger 30 causing liquid and air to flow into mixing chamber 24 and out outlet 26 . When trigger 30 is released, air is allowed to flow into headspace 28 from outside foam dispenser 10 . It should be understood that although air 22 within headspace 28 can be used for mixing with liquid cleaning composition 14 inside mixing chamber 24 , it should be understood that the container can be designed so that air is drawn from outside of container 12 rather than from headspace 28 . In addition, various techniques can be used to vent headspace 28 .
[0065] Now referring to FIG. 2 , a second foam dispenser is shown at reference number 40 . Foam dispenser 40 includes a container 42 holding a liquid 44 . In addition air 46 is provided in a headspace 48 . Foam dispenser 40 additionally includes a mechanical foaming head 50 having a trigger 58 attached to container 42 at a container neck 52 . A liquid inlet line 54 draws liquid 44 into mechanical foaming head 50 . In addition, an air inlet 56 draws air into mechanical foaming head 50 . When trigger 58 of foaming head 50 is depressed, liquid and air flow into mechanical foaming head 50 into a liquid and air mixing chamber 60 , and through an outlet 62 to outside of foam dispenser 40 . Outlet 62 can include a foam generating opening 64 that assists in the generation of a foam when the combination of the air and the liquid pass there through. Foam generating opening 64 can include a foam generating structure such as a screen 66 . In general, foam generating structure 64 can be any structure that creates turbulence and/or enhancing mixing of air and liquid to generate foaming. For example, the foam generating structure can include obstructions or projections into the path through which the air and the liquid pass. Exemplary foam generating structures include narrow orifices, tubes, etc. It is expected that foam dispenser 40 utilizes less intense mixing in mixing chamber 60 compared with the level of mixing obtained in mixing chamber 24 of the foam dispenser 10 ( FIG. 1 ). As a result, foam generating structure 64 can be provided to enhance contact between the liquid and the air to generate foaming.
[0066] Foam dispersers 10 , 40 are suitable for use with the composition of the present invention.
[0067] FIG. 3 is a photograph of the foam composition of the invention being applied via foam dispenser 40 to an automobile wheel. It is seen that the foam composition clings to the vertical wheel surface with minimal dripping.
[0068] Foam-Boosting Solvents
[0069] To facilitate the foaming of the composition, a foam-boosting solvent can be added. Not all solvents will necessarily function as foam-boosting solvents to cause a composition to foam when processed through a mechanical foaming head. Certain types of solvents that have been found to function as foam-boosting solvents can be characterized in several ways. For example, foam-boosting solvents that have assisted in the generation of a foam when a composition is processed through a mechanical foaming head can be characterized as having an HLB (hydrophilic-lipophilic balance) value of at least about 6.9 and an OHLB (organic hydrophilic-lipophilic balance) value of between about 12 and about 20. HLB is a measure of water miscibility with values of 7.3 or greater corresponding to complete water solubility. OHLB values refer to the partitioning ability between water and organic phase with higher OHLB values corresponding to a greater tendency to partition into the organic phase. HLB values and OHLB values for solvents are readily available for most solvents. Exemplary foam-boosting solvents that can be used can also be characterized as having a vapor pressure at room temperature of less than about 5 mmHg. The vapor pressure at room temperature can be less than about 1 mmHg, and can be less than about 0.1 mmHg. In addition, it may be desirable to provide the foam-boosting solvent as one characterized as GRAS (generally recognized as safe) by the FDA for direct or indirect food additives.
[0070] Exemplary foam-boosting solvents include glycols, glycol ethers, derivatives of glycol ethers, and mixtures thereof. Exemplary glycols include those having at least four carbon atoms such as hexylene glycol. Exemplary glycol ethers include alkylene glycol ethers and aromatic glycol ethers. Exemplary glycol ethers include those having the formula:
wherein R is a C 1 -C 6 aliphatic or aromatic group, R′ is H, CH 3 , or C 2 H 5 , and n has a value of at least 1. The value of n can be about 1 to about 4, or about 1 to about 3. An exemplary glycol ether includes dipropylene glycol methyl ether wherein R is CH 3 , R′ is CH 3 , and n has a value of 2. Another exemplary glycol ether is diethylene glycol butyl ether (sometimes referred to as butyl carbitol) wherein R is C 4 H 9 , R′ is H, and n has a value of 2. An exemplary aromatic glycol ether is ethylene glycol phenyl ether wherein R is a phenyl group, R′ is H, and n is a value of 1. Other exemplary glycol ethers include C 1 -C 6 alkylene glycol ethers such as propylene glycol butyl ether, dipropylene glycol propyl ether, ethylene glycol butyl ether, diethylene glycol propyl ether, and triethylene glycol methyl ether. Exemplary glycol ethers are commercially available under the name Dowanol® from the Dow Chemical Company. For example, n-propoxypropanol is available under the name Dowanol PnP. Exemplary derivatives of glycol ethers include those glycol ethers modified to include an additional group or functionality such as an ester group. Exemplary derivatives of glycol ethers include those having the following formula:
wherein R is a C 1 -C 6 aliphatic or aromatic group, R′ is H, CH 3 , or C 2 H 5 , n has a value of at least 1, and A is an ester, amide, or ether group. The value of n can be about 1 to about 4, or about 1 to about 3. An exemplary derivative of a glycol ether includes propylene glycol methyl ether acetate. It should be understood that certain glycol ethers and derivatives such as ethylene glycol phenyl ether can be used with additional solvents for coupling.
[0071] The composition can include an amount of the foam-boosting solvent to provide a desired foam when processed through a mechanical foaming head. It has been found that the amount of foam-boosting solvent that can be provided to assist in the generation of a foam can be provided in an amount that does not significantly decrease the viscosity of the composition prior to foaming. That is, the amount of the foam-boosting solvent can be provided so that the composition that includes the foam-boosting solvent has a viscosity that is within about 50 centipoise of an otherwise identical composition except not including the foam-boosting solvent when the viscosity is measured on a Brookfield viscometer, model DV-E, at 22° C. a spindle speed of 100 rpm and a number 4 spindle, or at a spindle and speed that provides for measurement of viscosity. It is expected that the foam-boosting solvent will be present in the composition, if at all, in an amount of at least about 0.1 wt. %, and can be included in an amount up to about 5 wt. %. An exemplary range of foam-boosting solvent in the composition is between about 0.1 wt. % and about 3 wt. %. Another exemplary range of the foam-boosting solvent is between about 0.5 wt. % and about 2 wt. %.
[0072] It is believed that the foam-boosting solvent can be provided in a composition containing a relatively low concentration of surfactant to help assist in the generation of a foam when processed through a mechanical foaming head. The amount of the foam-boosting solvent can be provided based upon the amount of total surfactant in the composition. For example, when the total amount of surfactant is relatively low, it is desirable to provide enough foam-boosting solvent so that the composition generates a foam when processed through a mechanical foaming head.
[0073] It is expected that at total surfactant concentrations of about 0.05 wt. % to about 10 wt. %, the foam-boosting solvent can be provided at a concentration of about 0.1 wt. % to about 5 wt. %, a concentration of between about 0.5 wt. % and about 3 wt. %, and a concentration of between about 1 wt. % and about 2 wt. %.
[0074] Other Optional Ingredients
[0075] As stated above, in its basic form, the composition of the present invention is a mixture of inorganic bisulfate salt, inorganic salt, and surfactant. If the composition is a foam composition, a foam-boosting solvent is present. Other ingredients can be added to this basic composition. Examples of optional ingredients for the composition include amphoteric surfactants (amine oxides, betaines, sultaines, amphoacetates, amphopropionates, etc.), aesthetic aids (fragrance, dyes, optical brighteners, etc.), viscosity modifiers (polymers, clay, etc.), solvents (water, glycol ethers, glycols, pyrrol and it's derivatives, alkyl carbonates, etc.), builders/chelants/sequestrants (phosphates, diamine derivatives, nitriloacetates, organophosphonates, polycarboxylates, hydroxycarboxylates, derivatives of aspartic acid, etc.), and processing aids (inorganic salts, excluding fluorides and bifluorides; polyethylene and/or polypropylene glycol; urea; inorganics carbonates and bicarbonates; inorganic halides; etc.).
[0076] Water
[0077] The composition concentrate is typically diluted with water to provide the ready-to-use composition and/or the use composition. In general, it is expected that the concentrate will be diluted with water at a weight ratio of at least about 1:1. In addition, it is expected that the dilution of the concentrate with water will be less than about 1:600. It is understood that a weight ratio of about 1:600 is slightly less than a dilution of about ¼ ounce concentrate to about 1 gallon of water. It is expected that the ready-to-use composition or the use composition will contain at least about 80 wt. % water. In addition, it is expected that the ready-to-use composition and/or the use composition will include at least about 90 wt. % water, preferably at least about 95 wt. % water, and more preferably at least about 96 wt. % water. In some read-to-use compositions, the level of water will be at least about 99 wt. %.
[0078] pH Modifier
[0079] The acid system, of the bisulfate and the inorganic salt, is naturally acidic with a pH of 1-7. An acid system of the bisulfate and the sulfate is naturally acidic with a pH of 2-3. In many embodiments, it is desired to modify that pH. The level of the pH will affect the ratio of bisulfate and salt (e.g., sulfate) in equilibrium. Exemplary pH modifiers include alkalinity sources and acidity sources. Exemplary alkalinity sources include inorganic bases (hydroxides, carbonates, bicarbonates, percarbonates, silicates, etc.) and organic bases (alkylamines, alkanolamines, etc.). Exemplary acidity sources include inorganic acids (bisulfates, phosphoric acid, hydrochloric acid, etc.) and organic acids (polycarboxyacids, hydroxycarboxylic acids, etc.).
[0080] It can be desirable to provide the use solution with a relatively neutral pH, alkaline pH, or acidic pH. In many situations, it is believed that the presence of hard water as water of dilution will cause the use solution to exhibit a neutral or alkaline pH. In order to ensure a relatively neutral pH, alkaline pH, or acidic pH a pH modifier can be incorporated into the concentrate. In general, the amount of pH modifier should be sufficient to provide the use solution with a pH in the desired range. Exemplary ranges include 1-6,7-8, and 9-14.
[0081] The pH modifier can include an alkalinity source. The alkalinity source can be organic and/or inorganic. Exemplary alkaline buffering agents include alkanolamines. An exemplary alkaline alkanolamine organic pH modifier is beta-aminoalkanol and 2-amino-2-methyl-1-propanol (AMP).
[0082] Exemplary alkanolamines are beta-aminoalkanol compounds. They serve primarily as solvents when the pH is about 8.5, and especially above about 9.0. They also can provide alkaline buffering capacity during use. Exemplary beta-aminoalkanols are 2-amino-1-butanol; 2-amino-2-methyl-1-propanol; and mixtures thereof. Beta-aminoalkanol is 2-amino-2-methyl-1-propanol can be desirable because of its low molecular weight. The beta-aminoalkanols can have boiling points below about 175° C.
[0083] Other suitable alkalinity agents that can also be used include alkali metal hydroxides, i.e., sodium, potassium, etc., and carbonates or sodium bicarbonates. Water-soluble alkali metal carbonate and/or bicarbonate salts, such as sodium bicarbonate, potassium bicarbonate, potassium carbonate, cesium carbonate, sodium carbonate, and mixtures thereof, can be added to the composition of the present invention in order to improve the filming/streaking when the product is wiped dry on the surface, as is typically done in glass cleaning. Preferred salts are sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, their respective hydrates, and mixtures thereof.
[0084] Exemplary inorganic acids include phosphoric acid, hydrochloric acid, nitric acid, sulfamic acid, mixtures thereof, or the like. Exemplary organic acids include lactic acid, citric acid, propionic acid, acetic acid, hydroxyacetic acid, formic acid, glutaric acid, maleic acid, hydroxy propionic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, mixtures thereof, or the like. The organic acid can be a mixture of adipic, maleic, and succinic acids sold under the trade name Sokalan.
[0085] Solvents
[0086] Solvents other than foam-boosting solvents can be included in the composition to provide the composition with desired properties. For example, certain solvents can be included in an amount to provide the desired cleaning and evaporative properties. In general, the amount of solvent should be limited so that the use solution is in compliance with volatile organic compound (VOC) regulations for a particular class of cleaner. In addition, it should be understood that the organic solvent is an optional component and need not be incorporated into the concentrate or the use solution according to the invention. When the organic solvent is included in the concentrate, it can be provided in an amount of between about 0.1 wt. % and about 50 wt. %, between about 5 wt. % and about 30 wt. %, and between about 10 wt. % and about 20 wt. %.
[0087] Builder/Sequestrant
[0088] The cleaning composition according to the invention can include complexing or chelating agents that aid in reducing the harmful effects of hardness components in service water. Typically, calcium, magnesium, iron, manganese, or other polyvalent metal cations, present in service water, can interfere with the action of cleaning compositions. A chelating agent can be provided for complexing with the metal cation and preventing the complexed metal cation from interfering with the action of an active component of the rinse agent. Both organic and inorganic chelating agents are common. Inorganic chelating agents include such compounds as sodium pyrophosphate, and sodium tripolyphosphate. Organic chelating agents include both polymeric and small molecule chelating agents. Polymeric chelating agents commonly comprise ionomer compositions such as polyacrylic acids compounds. Small molecule organic chelating agents include aminocarboxylates, polycarboxylates, and hydroxycarboxylates. Exemplary aminocarboxylates include ethylenediaminetetracetic acid (EDTA), and hydroxyethylenediaminetetracetic acid, nitrilotriacetic acid, ethylenediaminetetrapropionates, triethylenetetraminehexacetates, and salts thereof including alkali metal ammonium and substituted ammonium salts. Exemplary polycarboxylates include citric acid and citrate salt. Exemplary hydroxycarboxylates include hydroxyacetic acid, salicylic acid, and salts thereof.
[0089] Phosphonates are also suitable for use as chelating agents in the composition of the invention and include ethylenediamine tetra(methylenephosphonate), nitrilotrismethylenephosphonate, diethylenetriaminepenta(methylene phosphonate), hydroxyethylidene diphosphonate, and 2-phosphonobutane-1,2,4-tricarboxylic acid. Preferred chelating agents include the phosphonates amino-carboxylates. These phosphonates commonly contain alkyl or alkylene groups with less than 8 carbon atoms.
[0090] It should be understood that the concentrate can be provided without a component conventionally characterized as a builder, a chelating agent, or a sequestrant. Nevertheless, it is believed that these components can advantageously be incorporated into the cleaning composition. It is expected that their presence would not be provided in an amount sufficient to handle the hardness in the water resulting from the water of dilution mixing with the concentrate to form the use solution when the water of dilution is considered to be fairly hard water and the ratio of water of dilution to the concentrate is fairly high.
[0091] Exemplary builders/sequestering agents include ethylenediamine derivatives, ethylenetriamine derivatives, NTA, phosphates, organophosphonates, zeolites, hydroxyacids, their salts, and mixtures thereof.
[0092] Anti-Redeposition Agent
[0093] Exemplary anti-redeposition agents that can be used include carboxycellulose derivatives, acrylate polymers and copolymers, and mixtures thereof.
[0094] The composition of the present invention can be provided in various forms, such as a liquid concentrate, liquid ready-to-use, or solid. Provided below are various compositional ranges for compositions that can be characterized as surface cleaning compositions. It should be understood that particular compositions can be provided within any of the ranges identified, and the compositions may include components other than those disclosed in the tables.
[0095] A preferred non-liquid composition, for forming into a mixture, dispersion or solution prior to use, can be described as containing various levels of ingredients, as provided below:
Wt- % Wt- % Wt- % bisulfate (part of acid system) 1-99 20-70 30-60 metal inorganic salt (part of 1-99 20-70 30-60 acid system), such as sulfate EO-PO copolymer (nonionic 0.01-50 0.1-10 0.2-5 surfactant) alcohol ethoxylate (nonionic 0.01-50 0.1-10 0.2-5 surfactant) quaternary ammonium 0.01-20 0.05-10 0.07-5 compound (cationic surfactant) alkyl sulfonate 1-40 2-20 3-10 (anionic surfactant) aryl sulfonate 0-20 0.1-10 0.3-8 (anionic surfactant) potassium hydrogen 0-50 0-35 0-25 phosphate (carrier or builder)
[0096] A preferred liquid concentrated composition, for further dilution prior to use, can be described as containing:
Wt- % Wt- % Wt- % bisulfate (part of acid system) 1-99 20-70 30-60 metal inorganic salt (part of 1-99 20-70 30-60 acid system), such as sulfate EO-PO copolymer (nonionic 0.01-50 0.1-10 0.2-5 surfactant) alcohol ethoxylate (nonionic 0.01-50 0.1-10 0.2-5 surfactant) quaternary ammonium 0.01-20 0.05-10 0.07-5 compound (cationic surfactant) alkyl sulfonate 1-40 2-20 3-10 (anionic surfactant) aryl sulfonate 0-20 0.1-10 0.3-8 (anionic surfactant) potassium hydrogen 0-50 0-35 0-25 phosphate (carrier or builder) glycol ether solvent (foam- 0-30 0.1-15 0.5-10 boosting solvent) Water 1-99 30-80 40-70
[0097] A preferred ready-to-use liquid composition can be described as containing:
Wt- % Wt- % Wt- % bisulfate (part of 0.01-10 0.1-5 0.5-3 acid system) metal inorganic salt 0.01-10 0.1-5 0.5-3 (part of acid system), such as sulfate EO-PO copolymer 0.0001-5 0.001-1 0.002-0.5 (nonionic surfactant) alcohol ethoxylate 0.0001-5 0.001-1 0.002-0.5 (nonionic surfactant) quaternary ammonium 0.0001-5 0.001-1 0.002-0.5 compound (cationic surfactant) alkyl sulfonate 0.01-10 0.05-5 0.1-0.5 (anionic surfactant) aryl sulfonate 0-10 0.05-5 0.1-0.5 (anionic surfactant) glycol ether solvent 0-5 0.1-3 0.5-2 (foam-boosting solvent) water 10-99.99 40-99 60-98
[0098] In some use-compositions, the amount of acid package is no more than about 20 wt-%, no more than about 10 wt-% in other compositions, and no more than about 6 wt-% in other compositions. Also in some use-compositions, the amount of surfactant is no more than about 35 wt-%, no more than about 15 wt-% in other compositions, and no more than about 2.5 wt-% in other compositions.
[0099] Some exemplary components that can be included in the exemplary compositions shown in the above Tables are identified in the Examples below. It should be understood that the various exemplary components may be more useful in one type of composition than another.
EXAMPLES
[0100] The present invention can be better understood with reference to the following examples. These examples are intended to be representative of specific embodiments of the invention, and are not intended as limiting the scope of the invention.
Example 1
Solid Wheeler Cleaner Composition
[0101] Solid wheel cleaners were prepared by mixing the components listed below and then compressing the mixtures into solids. Five compositions (A, B, C, D and E) were prepared.
Wt. % Wt. % Wt. % Wt. % Wt. % Ingredient Comp. A Comp. B Comp. C Comp. D Comp. E dodecylbenzene sulfonic 1.52 2.96 2.75 2.80 3.35 acid Tetronic 901 (BASF) 0.46 0.90 0.83 0.85 1.01 Variquat CC-42NS 0.05 0.09 0.08 0.08 0.10 (Goldschmidt) Pluronic N3 (BASF) 0.37 0.72 0.67 0.68 0.81 Hostapur SAS60 (Hoechst) 1.93 3.76 3.50 3.56 0.00 sodium octane sulfonate 0.00 0.00 0.00 0.00 2.55 nonyl phenol ethoxylate 0.28 0.54 0.50 0.51 0.61 sodium xylene sulfonate 2.89 0.54 5.26 5.34 3.04 NaHSO 4 46.18 45.25 38.92 41.50 44.33 Na 2 SO 4 46.33 45.25 19.57 41.39 44.20 KH 2 PO 4 0.00 0.00 20.41 0.00 0.00 water 0.00 0.00 0.00 3.30 0.00
[0102] The five compositions were evaluated for their pH, whether or not they were compressible into solid tablets, and whether or not the composition, when dissolved in water to form a solution, corroded aluminum 6061 or stainless steel 316. The results are below. All five compositions provided suitable results.
Comp. A Comp. B Comp. C Comp. D Comp. E 1% pH 2.13 2.18 2.25 2.19 2.20 compressible? yes yes yes Yes yes corrodes aluminum 6061? no no no No no corrodes stainless steel no no no No no 316?
Example 2
Solid Aluminum Brightener
[0103] A composition was prepared from the ingredients below and compressed into a solid. A very dilute solution prepared from the minimal residue in the beaker that the solid was mixed in gave excellent brightening of an aluminum 6061 coupon.
Ingredient Wt. % Sodium bisulfate 35.60 Sodium sulfate 60.00 Colonial IES quat 1.44 Varonic K1215 2.96
Example 3
Ready-to-use Liquid Foam Wheel Cleaner Composition
[0104] A ready-to-use liquid wheel cleaner composition was prepared from the ingredients listed below and dispensed as a spray-on foam onto soiled automobile aluminum wheels, chromed wheels, and steel wheels. Brake dust and road soil were removed from all three wheels without any visible evidence of damage to any of the surfaces. The surface of the aluminum wheel was visibly brightened.
Ingredient Wt. % Water 97.42 Sodium sulfate 0.89 Sodium bisulfate 0.89 Dodecylbenzene sulfonic acid 0.08 Tetronic 901 (BASF) 0.02 Variquat CC-42NS (Goldschmidt) 0.002 Pluronic N3 (BASF) 0.01 Hostapur SAS60 (Hoechst) 0.07 Laureth-Myristeth-7 EO 0.01 Sodium xylene sulfonate 0.11 Dipropylene glycol ether methyl ether 0.50
Example 4
Comparison of Compositions
[0105] The composition of Example 3 was applied to aluminum 6061 coupons for 5 minutes at both ambient and at elevated temperature, 120° F. Similarly, three commercially available wheel cleaners were also used to treat aluminum 6061 coupons.
[0106] The two compositions containing bifluoride immediately attacked the aluminum with bubbling, pitting, and darkening of the metal. The composition having oxalic acid did not attack the aluminum, but neither did it brighten it. The composition according to the present invention, Example 3, brightened the dull aluminum coupon and did not adversely affect it, demonstrating an advantage over current products in performance and aluminum compatibility, even at elevated temperatures.
Wheel Cleaner Brightening Agent Ambient 120° F. Example 3 sodium bisulfate/sulfate brightened brightened Meguiar's Instant ammonium bifluoride pitting severe pitting Wheel Cleaner Armor All Wheel ammonium bifluoride pitting severe pitting Cleaner Turtlewax Wheel oxalic acid no change no change Cleaner
Example 5
Removal of Dirt and Grime
[0107] Half of an aluminum wheel, on an automobile being driven generally daily, was sprayed with a cleaner foam composition according to the present invention. The results are shown in FIG. 4 , which is a photograph of the automobile wheel after one half has been cleaned with the foam composition of the invention and the other half was not cleaned.
[0108] The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | A cleaning composition including a metal bisulfate and metal inorganic salt acid package, and at least one surfactant. The cleaning composition can be a one-step wheel cleaner/brightener. The composition preferably contains no HF, no bifluoride, no oxalic acid, or other poisonous and highly toxic materials commonly found in both industrial and consumer wheel cleaners. Further, the wheel cleaner/brightener composition matches or exceeds the performance of those hazardous formulations and does not damage aluminum wheels even when applied to hot metal. The composition can be a foam composition, provided in a foam dispenser. The foam dispenser includes a container and a mechanical foaming head. The container includes a cleaning composition containing a metal bisulfate and metal sulfate acid package, and at least one surfactant, water, and a foam-boosting solvent. | 2 |
This invention is a continuation-in-part of application Ser. No. 448,158, filed Mar. 4, 1974, now abandoned.
BACKGROUND OF THE INVENTION
Solid electrolyte batteries having a molten alkali metal are known in the art. U.S. Pat. No. 2,631,180 by Robinson teaches a primary cell in which the alkali metal anode is enclosed in a sealed glass envelope. The glass envelope acts as a barrier electrolyte, however, relatively high resistance of the glass permits only small currents to be delivered by the cell.
U.S. Pat. No. 3,404,035 by Kummer et al discloses a secondary battery which uses a β-alumina electrolyte with a sulfur cathode and a sodium anode. The battery is operated in a temperature range of about 200° C to about 600° C to maintain the anode and cathode in a molten state. Other patents to Kummer et al using similar arrangements are U.S. Pat. Nos. 3,404,036 and 3,413,150.
U.S. Pat. No. 3,773,558 by Charbonnier et al teaches a primary cell which uses a β-alumina electrolyte with a transition metal fluoride cathode and an anode of alkali or alkaline-earth metal alloy in liquid phase. The anode is comprised of at least two metals having a solid/liquid boundary at a relatively low operating temperature not more than about 100° C.
SUMMARY OF THE INVENTION
The present invention relates to a cell which employs a solid β-alumina electrolyte together with a solid alkali metal anode and a fluid oxidizer cathode. The cathodic oxidizer may be an oxidizing gas dissolved in an organic solvent, or it may be a liquid organic electrolyte solution of an inorganic salt or a metal no higher in the electromotive series than the alkali metal being used for the anode, or it may be a liquid organic electrolyte solution of an organic oxidizer.
These cells exhibit voltages in the range of 2.5 to 3.5 volts, depending upon choice of reactants. Thus, the cells provide a relatively cheap source of electrical power which may be used for small electronic devices, such as electronic watches, heart pacemakers, C-MOS circuits, and other similar devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of one embodiment of a cell according to this invention with parts broken away to show the anode and cathode electrodes and the β-alumina electrolyte separator;
FIG. 2 is a sectional view of the cell of FIG. 1 taken along lines 2--2; and
FIG. 3 is a graphical representation of the voltage drop during discharge of a sodium-tetracyanoethylene cell.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In cells using a solid alkali metal anode, the ceramic electrolyte must be specifically modified by incorporating ions or atoms of alkali metals in the ceramic matrix which are identical to the alkali metal which will migrate through the electrolyte as ions. That is, if the cell is designed to have a sodium metal anode, then the ceramic matrix must include sodium atoms or ions in the aluminate ceramic matrix. Ceramics which are found to be most suitable for the applications of this invention are designated in the art of β-alumina. Methods for making β-alumina and other ionic conducting formulation of sodium aluminates are disclosed in the prior art, e.g. U.S. Pat. No. 3,468,719.
Although the theory is not clearly understood as to the operation of β-alumina solid electrolytes, it is believed that the ions from the alkali metal migrate through the β-alumina barrier and react with the cathodic oxidizer to produce a salt of the alkali metal and the oxidizer, giving up an electron in the process. The following equation is illustrative of the reaction in which sodium is used for the example:
Na → Na.sup.+ + e.sup.- (I)
o.sub.2 + d.sup.- → O.sub.2 - (II)
the β-alumina barrier should be as thin as possible and still maintain structural integrity. This is because the internal resistance of the battery is proportional to the thickness of the barrier material, i.e. the greater the distance the alkali metal ions have to migrate, the greater the internal resistance to the battery. Thus, depending upon the formulation of the ceramics, cells which do not have a pressure differential between the anode chamber and the cathode chamber may be fabricated as thin as engineering techniques will allow, usually between 0.01 centimeter and 0.1 centimeter. On the other hand, if the pressure differential exists between the cathode chamber and the anode chamber, as for example where the cathode material is a gas under pressure, the β-alumina electrolyte must be of sufficient thickness to maintain its structural integrity. While gas pressure in the cathode chamber is not a major concern because the alkali metal in the anode chamber is solid, thus providing reinforcement for the electrolyte wall in most circumstances, attention is drawn to the avoidance of excessive gaseous pressures which could result in the failure of the fragile electrolyte wall.
Referring to the drawings, FIG. 1 shows a cell having a casing 1 which is made from a dielectric material having reasonable structural strength, e.g. glass, plastic, ceramic, or any of a numbers of structural metals such as aluminum, iron, copper, and alloys. Cathodic reactant 2 is situated in the outer chamber of the cell and is in intimate contact with current collector surface 3. Current collector 3 may have any of a number of forms including a wire mesh, a coated surface, of a plated surface and may be selected from any of several materials, e.g. carbon, stainless steel, nickel, mercury, gold, of platinum. Current collector 3 is brought into contact with conductor 4 to provide an exterior cathodic contact. Current collector 3 should be in intimate contact with β-alumina electrolyte 5 in order to reduce the internal resistance of the cell. If current collector 3 is carbon or platinum, then the cathode current collector 3 can be deposited on the outer surface of electrolyte 5.
Alkali metal anode 6 occupies the central chamber of the cell and is contained by β-alumina electrolyte 5 and αseal 7 which is impervious to the flow of alkali metal ions. Conductor 8 provides means to transmit the current from the anode chamber to an external contact. Power will be supplied by the primary cell upon completion of a circuit from the anode electrode conductor 8 to the cathode electrode conductor 4.
FIG. 2 shows a sectional view of the cell in FIG. 1 along lines 2--2. It should be noted that the figures in the drawing illustrate only one possible embodiment, and numerous variations of the physical configuration may be possible within the scope of the present invention.
Sodium is the preferred metal anode reactant for the purposes of this invention. Various other metal ions will move through β-alumina solid electrolyte barrier, however, sodium is the preferred choice because greater power outputs per pound of material have been achieved with sodium than with other metals.
Fluid cathodic oxidizer reactants may be selected from any of several liquid or gaseous materials. Liquid cathodic reactants may be selected from liquid inorganic and organic oxidizers or a liquid solution of an inorganic or an organic oxidizer.
Gases such as air, oxygen, chlorine, iodine, fluorine, bromine, nitrogen oxides, ozone, to name a few, also may be used as the cathodic reactant. When gaseous reactants are used, current collectors are necessary. Platinum is the preferred of the current collectors materials, however, carbon, stainless steel, nickel, mercury or gold may be used, also. Gas pressures of reasonable amount may be used. Limiting factors to consider are pressures sufficiently high to provide the cell with a reasonable life, and pressures low enough that the pressure differential between the anode chamber and the cathode chamber will not overstress the β-alumina barrier causing cracks or fissures. The danger of high pressure cracking the β-alumina barrier is minimized by the fact that the anode comprises a solid alkali metal material. However, care should be taken to avoid overstressing the fragile β-alumina barrier.
Where the cathode employs an organic solvent, generally, any polar aprotic organic solvent will be suitable. Specific examples of polar organic solvents which are illustrative of, but not limited to the following compounds acetonitrile, dimethylsulfoxide, propylene carbonate, or dimethylformamide. Generally, polar solvents provide a suitable solvent medium for large number of inorganic compounds. Although there are many other polar organic solvents other than the few examples given, the chief criteria for the solvent is that the inorganic compound dissolves therein.
Liquid organic oxidizers may be selected from solutions of tetracyanoethylene (TCNE), quinones, nitrobenzenes, tetracyanoquinodimethan (TCNQ), phenazinium salts, to name a few. The invention will be more clearly understood by referring to the following examples. These examples illustrate specific embodiments and should not be construed as limiting the invention.
EXAMPLE I
Approximately 0.3 mole of tetracyanoethylene dissolves in 2.8 grams of 0.5 molal solution of sodium hexafluoroarsenate in propylene carbonate, were placed into a clean, dry, cylindrical glass vessel. A cylindrical cup made of β-alumina was filled with sodium and placed in an oven. The sodium filled cup was heated above 300° C until the electrical resistance drops substantially. The cup is removed from the oven, and the liquid sodium is poured out of the cup. The β-alumina cup is placed in a furnace and fired at 800° C for at least one hour. The cup is removed then and cooled in a protective atmosphere of helium, nitrogen, or argon. Next, platinum gauze with a wire conductor soldered thereto was immersed in the organic liquid in the glass vessel. A cylindrical cup of β-alumina having an outside diameter slightly less than the inside diameter of the platinum gauze was placed in the center of the platinum gauze cylinder. A nickel wire conductor was immersed in the sodium and extended above the top of the cylindrical glass vessel. The cylindrical glass vessel was sealed with epoxy resin.
The following tables provide a comparison of power and energy outputs of the cell of this example with prior art mercury and silver oxide cells.
TABLE I______________________________________Type of Cell Hg.sup.1 AgO.sup. 2 Na/TCNE.sup.3______________________________________Open Circuit Voltage, V 1.40 1.60 3.20Nominal Operating Voltage, V 1.32 1.50 3.00Total Capacity, ma-h 1.60 165 57.7Output Power, μw 30 30 30Specific Power, μw/g 15.1 11.7 28.8Power Density, μw/cm.sup.3 59.5 59.5 70.6Total Energy, mw-h 224 247 173Specific Energy, mw-h/g 113 96.7 167Energy Density, mw-h/cm.sup.3 454 502 408Operating Life at 30 μw, hr 7,460 8,230 5,770______________________________________ .sup.1 No. 675E mercury cell .sup.2 No. 303 silver oxide cell .sup.3 Na/TCNE cell of comparable packaging at 220° C
TABLE II______________________________________Na-TCNE CELL______________________________________CAPACITY (Based on active material): 380 Coulomb; 106 mA hr (±5%)OPEN-CIRCUIT VOLTAGE: Initial 3.2 V After Half Discharge 2.1 VLOAD (After half discharge): 100 kΩCURRENT (After half discharge): 3.0 μAVOLTAGE (After half discharge): 0.30 VTOTAL DISCHARGE (50 months): 397 Coulomb; 110 mA hr______________________________________
Table II shows a fifty-month's performance of the cell in this example. When placed in operation, the cell had an open-circuit voltage of 3.2 volts. At the end of the fifty-month period, during which the load specified in Table II remained constant, the open-circuit voltage was 2.1 volts. FIG. 3 shows a plot of the open circuit voltage drop over a fifty-month discharge.
EXAMPLE II
A cell substantially identical to that of Example I was constructed except that the catholyte consisted of 0.2 mole of sodium hexafluoroarsenate in 10 grams of dimethylsulfoxide. Air was bubbled through this solution. In addition, the platinum gauze was replaced by a gauze of gold-mercury amalgam. The β-alumina electrolyte has a surface area of 1.54 cm and a thickness of 0.14 cm. The cell was operated in a temperature region of 90° C. Open-circuit voltage of the cell was 2.6 to 2.8 volts and the internal resistance was approximately 350 ohms. The short circuit discharge current was approximately 9 mA and the discharge current across a 350 ohm load was 4.5 mA at 1.3 volts. | A cell is fabricated using a solid alkali metal anode and a fluid cathode which are separated by a modified aluminate solid barrier which permits the flow of only the alkali metal ions. The fluid cathode can contain a solid, gaseous, or liquid oxidizer in a liquid electrolyte. Operating temperatures for these cells range from less than -40° C to approximately 95° C. At ambient temperatures, energy densities of the cells range from approximately 0.7 to 1.8 watt-hour per cubic centimeter. These cells are electrically rechargeable by raising their temperature above the melting point of sodium. | 7 |
RELATED APPLICATIONS INFORMATION
This application is a continuation of Ser. No. 13/708,353, filed on Dec. 7, 2012, which is a continuation to U.S. patent application Ser. No. 11/962,047, filed Dec. 20, 2007, now U.S. Pat. No. 8,344,890, issued on Jan. 1, 2013, which in turn claims the benefit under 35 U.S.C. 119(e) to U.S. Provisional Patent Application Ser. No. 60/871,273, filed Dec. 21, 2006, all of which are incorporated herein by reference in their entirety as if set forth in full.
BACKGROUND
1. Field of the Invention
The embodiments described herein relate generally to electronic vehicle registration and tracking systems, and more particularly to the use of Radio Frequency Identification (RFID) in such systems.
2. Background of the Invention
RFID technology has long been used for electronic vehicle tolling applications. In such applications, an RFID reader or interrogator is position over or near a road way at a point where a toll is to be collected. An RFID tag is then place in each vehicle that includes an identifier by which the vehicle can be recognized, e.g., the vehicle's license plate number. The interrogator then uses RF signals to interrogate the tag and obtain the identifier so that the toll can be applied to the correct vehicle, or account.
Generally, the tag to interrogator communication is achieved through a form of modulation known as backscatter modulation. In a backscatter modulation system, the tag does not generate its own RF carrier signal when transmitting information to the interrogator. Rather, the interrogator generates an RF carrier and modulates the carrier with data intended for the tag, e.g., a request for the tags identifier information. The tag receives the modulated signal decides the data and then performs actions in accordance therewith e.g., accesses the memory and obtains the requested identifier information. The interrogator continues to transmit the RF carrier, now with no data on it. The tag receives this un-modulated carrier and reflects it back to the interrogator. This is called backscatter. In order to send data back to the interrogator, e.g., identifier, the tag modulates the reflected, or backscatter signal with the data.
For example, the tag will alternately backscatter and not backscatter the RF carrier signal for a certain period of time in order to transmit a digital “0” an “1” respectively. Thus, the tag modulates the backscatter signal by reflecting or not reflecting the signal based on the data, i.e., “1s” and “0s,” to be sent. The interrogator receives the modulated backscatter signal and decodes the information received thereon.
Early on, such tags were active device, meaning they possessed their own power source, such as a battery. An active tag was necessary, for example, in order to generate enough power in the reflected signal to transmit information over extended distances. But more recently, passive tag technology has become more viable. A passive tag does not include a battery or power source of its own. Rather, energy in the RF signals received from the interrogator is used to power up the tag. For example, the received RF signal can be rectified and used to charge up a capacitor that is then used to power the tag.
As antenna and integrated circuit technology has evolved, larger and larger distances can be achieved with passive tags of smaller and smaller dimensions. Accordingly, small, thin, light weight tags can be used in a wide variety of applications. Often these tags are referred to as sticker tags or RFID labels, because of their dimensions and the fact that they can be manufactured to include an adhesive layer so that they can be applied to the outside of containers, the surface of documents, inventory, etc. In other words the tags can be applied like a label or sticker.
The emergence of passive, sticker tag technology has also greatly reduced the cost of implementing an RFID system. As a result, new applications, such as Electronic Vehicle Registration (EVR) using RFID, have emerged. Currently, e.g., in the United States, a vehicle owner registers their vehicle with the State government and pays a fee. The owner is then provider a sticker, which is applied to the vehicle license plate, to evidence the valid registration of the vehicle; however, these stickers can easily be counterfeited or stolen, i.e., removed and applied to another vehicle. Such activity is difficult to detect, because the only way to determine that a registration sticker does not belong on a certain vehicle is to access a database and check the corresponding information.
For example, in the United States, an estimated five to ten percent of motorists fail to legally register their vehicles, resulting in lost annual state revenues of between $720 million and $1.44 billion. Outside of the United States, some government agencies report the problem at 30-40% of the vehicles.
Deploying an Electronic Vehicle Registration system can help Motor Vehicle Administrators achieve increases in vehicle compliance and associated revenues by eliminating the need to rely on inefficient, manual, visual-based compliance monitoring techniques. EVR uses RFID technology to electronically identify vehicles and validate identity, status, and authenticity of vehicle data through the use of interrogators and tags that include data written into the tag memory that matches the vehicle registration data. Fixed, e.g., roadside, or handheld interrogators can then be used to read the data out when required. Thus, RFID technology can enable automated monitoring of vehicle compliance with all roadway usage regulations, e.g., vehicle registration, tolling, etc., through a single tag.
There are two common ways of attaching a RFID tag to a vehicle, one is using an RFID label tag attached to the windshield of the vehicle. The tag can then be read by a roadside or handheld reader. A second method of attaching the tag to a vehicle is to embed the RFID tag into the license plate. This has the convenience an continuity of replicating the application of current registration stickers; however, such a solution can also suffer from reduced transmission, i.e., communication distance due to the effects the metal license plate has on the performance of the tag antenna.
For example, as illustrate in FIG. 1 , a RFID tag 100 consisting of a RFID chip 102 and an antenna 104 can be mounted on the vehicle license plate 110 . As mentioned, however, license plate 110 is usually made from metal. As a result, the tag information may not be readable due to the shielding effects of metal surrounding tag 100 . Moreover, if tag 100 is directly applied to the metal surface of license plate 110 , then tag antenna 104 can be shorted or severely detuned by the metal surface. As a result, tag 100 will not be read, or will only be readable at very short distance.
A conventional approach to overcoming this issue is to leave some spacing 202 between tag 100 and metal license plate 110 as shown in FIG. 2 . Such a solution has an added benefit in that metal license plate 110 can also serve as a back plane for tag antenna 104 . For example, as illustrated in FIG. 3 , an RFID tag 100 can be housed within an non-metal enclosure 302 , e.g., formed from a low dielectric material that includes a spacer 304 such as an air gap or foam material.
One problem with such a conventional solution is the increased dimension, i.e., thickness of the resulting license plate assembly. Accordingly, conventional approaches force a tradeoff between reduced performance, or increased size and dimensions, which can have a negative impact.
SUMMARY
In the embodiments described herein, a RFID enabled license plate is constructed by using the license plate, or a retro-reflective layer formed thereon as part of the resonator configured to transmit signals generated by and RFID chip integrated with the license plate.
For example, in one aspect, such an RFID enabled license plate can include a metal license plate with a slot formed in the metal license plate, and a RFID tag module positioned in the slot. The RFID tag module can include a chip and a loop, and the loop can be coupled with the metal license plate, e.g., via inductive or conductive coupling. In this manner, the metal license plate can be configured to act as a resonator providing increased performance.
In another aspect, the RFID tag module can be positioned substantially within the slot such that the addition of the RFID tag module does not increase the thickness of the license plate.
In still another aspect, the RFID enabled license plate can comprise a RFID tag module, positioned in the slot, which includes a chip and contacts. The contacts connected with the metal license plate, e.g., via a conductive paste or a solder connection.
In still another aspect, the RFID enabled license plate can comprise a license plate and a retro-reflective layer formed over the license plate. A slot can then be formed in the retro-reflective layer, and a RFID tag module can be positioned in the slot. The RFID tag module can include a chip and a loop, and the loop coupled with the retro-reflective layer, e.g., via inductive or conductive coupling.
In still another aspect, the RFID enabled license plate can include a retro-reflective layer formed over the license plate and a slot formed in the metal license plate. A RFID tag module can be positioned in the slot. The RFID tag module can comprise a chip and contacts, and the contacts connected with the metal license plate, e.g., via a conductive paste or a solder connection.
These and other features, aspects, and embodiments of the invention are described below in the section entitled “Detailed Description.”
BRIEF DESCRIPTION OF THE DRAWINGS
Features, aspects, and embodiments of the inventions are described in conjunction with the attached drawings, in which:
FIG. 1 is a diagram illustrating an exemplary license plate comprising an RFID module;
FIG. 2 is a diagram illustrating a side view of the license plate of FIG. 1 ;
FIG. 3 is a diagram illustrating a RFID module that can be used in conjunction with the license plate of FIGS. 1 and 2 ;
FIGS. 4A and 4B are diagrams illustrating an example RFID enabled license plate in accordance with one embodiment;
FIGS. 5A and 5B are diagrams illustrating methods for coupling an RFID module with the license plate of FIGS. 4A and 4B ;
FIGS. 6A-C are diagrams illustrating an example RFID enabled license plate in accordance with another embodiment;
FIGS. 7A-C are diagrams illustrating example RFID enabled license plate in accordance with another embodiment;
FIG. 8 is a diagram illustrating another example RFID enabled license plate in accordance with another embodiment; and
FIG. 9 is a diagram illustrating another example RFID enabled license plate in accordance with another embodiment.
DETAILED DESCRIPTION
The embodiments described below are directed to system and methods for a RFID enabled license plate in which a metal layer of the license plate is actually used to radiate backscattered energy generated by a RFID tag positioned within a slot created in the license plate. Accordingly, not only does the metal license plate not interfere with the operation of the tag, it actually assists.
Certain embodiments described herein are directed to methods for creating an antenna structure directly on (1) a metal license plate, (2) a metalized retro-reflective foil covering a non-metal license plate, or (3) a metalized retro-reflective foil covering the metal license plate. Depending on the embodiment, the RFID chip can be directly connected to or electrically coupled, either capacitive or inductively, with the antenna structure. The antenna structure can be a single or multi-frequency resonant structure.
FIG. 4 , comprising FIGS. 4A and 4B , is a diagram illustrating an example license plate 400 comprising an RFID tag in accordance with one embodiment. As shown in FIG. 4A , license plate 400 can comprise an open area, or slot 402 . For example, slot 402 can be cut into metal license plate 400 . Alternatively, slot 402 can be punched out of plate 400 . As shown in FIG. 4B , a RFID tag module 406 comprising an enclosure around tag 404 can then be positioned within slot 402 . The dimensions of slot 402 and module 406 can be designed such that module 406 fits within slot 402 creating a substantially planar surface with the surface of metal license plate 400 . It should be noted that the top of module 406 is shown extending beyond the surface of license plate 400 in FIG. 4B , creating a non-planar surface; however, this is purely for illustration. In practice, module 406 can be made extremely thin allowing for a substantially planar surface across all of plate 400 , including slot 402 , even when module 406 is installed therein.
For example, module 406 can be similar to the module illustrated in FIG. 3 . Thus, module 406 can include an enclosure if required. Module 406 can then be configured to include a feeding loop that can couple tag 404 with metal license plate 400 . In this manner, the entire license plate 400 can then serve as an effective radiator via inductive coupling through the feeding loop.
FIGS. 5A and 5B illustrate two example implementations of the embodiment illustrated in FIG. 4 . In FIG. 5A , module 406 comprises a chip 502 coupled with a feeding loop 504 . Slot 402 is then positioned such that feeding loop 504 will be inductively coupled with metal license plate 400 . In FIG. 5B , slot 403 is positioned such that feeding loop 504 is capacitively coupled with metal license plate 400 .
Further, in certain embodiments, the radiation gain can be enhanced by using the metallic car frame (not shown). For example, with a properly designed tag antenna and proper consideration of the spacing between the metallic car frame and license plate 400 , the metal car frame can be used as a good antenna reflector.
In another embodiment, a structure very similar to Planar Inverted-F Antenna (PIFA) can be implemented by screwing the license plate directly to the metallic car frame as illustrated in FIG. 6 . In FIG. 6 , which comprises FIGS. 6A-C , metallic screws serve as shorting posts 602 and metallic car frame 600 serves as a ground plane for the antenna of tag module 406 .
FIG. 7 , comprising FIGS. 7A, 7B, and 7C , is a diagram illustrating an example of a license plate 700 configured to incorporate an RFID tag in accordance with another embodiment. As shown in FIG. 7A , an area, or slot 702 is cut, or punched, etc., in license plate 700 . As shown in FIG. 7B , a non-metal material 704 can then be inserted into slot 702 such that both the front and rear surfaces of license plate 700 are flat. Material 704 can be stuffed, extruded, etc., into slot 702 . As shown in FIG. 7C , an RFID “strap” comprising a chip 708 with contacts 710 can then be positioned over slot 702 as illustrated. Contacts 710 can then be connected to or capacitively coupled with metal license plate 700 . Depending on the embodiment, strap 712 can be placed on either the front surface or the rear surface of the license plate. The entire license plate 700 then becomes a slot antenna coupled with the RFID chip, which is less sensitive to the metallic car frame in terms of tag antenna detuning effect. Contacts 710 can be soldered to plate 700 , adhered using a conductive paste, or both.
It should also be noted that strap 712 can be made extremely thin, such that the surface of license plate 700 is substantially planar.
In certain embodiments, the dimensions of slot 702 can be altered, or multiple slots included to create a dual or multiple resonance frequency slot antenna. In such configurations, the tag will respond to multiple frequency bands, such as the Ultra High frequency (UHF) band, e.g., 900 MHz, and the microwave band, e.g. 2.45 GHz. This can allow multiple application capability. For example, depending on the application, one frequency band can be preferred for its localization characteristics and another frequency band can be preferred for its long range read capabilities. More specifically, a higher frequency band, such as a 2.45 GHz band, can be used for write applications as its limited range helps insure only the tag of interest is written to, while a lower frequency band, such as a 900 MHz band, can be used for multi-tag read applications as its greater range allows many tags to be read over a large area. In other embodiments, multiple frequency bands can be needed due to regulatory requirements that can vary the authorized frequency band based on locations, e.g., country, city, etc., and by application.
FIGS. 8 and 9 are diagrams illustrating example multi-frequency RFID license plates in accordance with two example embodiments. In FIG. 8 , two slots 802 and 804 are formed in metal license plate 800 . A strap 806 is then positioned across slot 806 as illustrated. The two slots 802 and 804 are configured, with respect to dimensions, spacing, location, etc., such that the slot antenna formed from license plate 800 , slots 802 and 804 and strap 806 will resonate at the desired frequencies, e.g., the UHF and microwave bands.
In FIG. 9 , two slots 902 and 904 are formed in license plate 900 ; however, in this example, slots 902 and 904 are connected via slot 906 . A slot 910 then extends to the edge of plate 900 . Strap 908 is then positioned across slot 910 as illustrated. Again, slots 902 , 904 , 906 , and 910 are configured such that the resulting slot antenna resonates at the desired frequencies.
The slots of FIGS. 8 and 9 can be filled with non-metallic material as in the example of FIG. 7 depending on the embodiment. Further, certain parasitic elements can be included, or changed to achieve the proper multi-frequency operation. It should also be noted that the embodiments of FIGS. 4 and 5 can also be configured as multi-frequency resonant structures via the inclusion of further slots appropriately constructed so as to allow the structure to resonate at the desired frequencies.
It will be understood that other slot dimensions, locations, spacing, interconnectedness, etc., are possible and will depend on the requirements of a particular implementation. Similarly, the position of the strap comprising the chip and connectors can vary as required by a particular implementation. Accordingly, the specific implementations illustrated herein should not be seen as limiting the embodiments disclosed to any particular configuration.
It will also be understood that the impedance of the resulting antenna structure in the above embodiments will need to be matched to that of the chip. This can impact the slot dimensions, etc. It can also require additional circuit elements, i.e., the inclusion of a matching circuit.
A retro-reflective film can be used to cover the front surface of the license plate. Such a film can make the license plate modification invisible from front view; and can also makes the license plate viewable in dark lighting. If the retro-reflective film contains metal materials, e.g., a metallized polymer film, then a selective metal removal process can be applied such that the film area covering the open area in the license plate is de-metallized. Such a de-metallization is described in detail in co-owned U.S. Pat. No. 7,034,688, as well as Co-owned patent application Ser. No. 10/485,863, each of which are incorporated herein by reference as if set forth in full. In other embodiments, the antenna structure can actually be formed on a retro-reflective layer that is then applied to a non-metallic, or metallic, license plate.
While certain embodiments of the inventions have been described above, it will be understood that the embodiments described are by way of example only. Accordingly, the inventions should not be limited based on the described embodiments. Rather, the scope of the inventions described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings. | In the embodiments described herein, a RFID enabled license plate is constructed by using the license plate, or a retro-reflective layer formed thereon as part of the resonator configured to transmit signals generated by and RFID chip integrated with the license plate. Such an RFID enabled license plate can include a metal license plate with a slot formed in the metal license plate, and a RFID tag module positioned in the slot. The RFID tag module can include a chip and a loop, and the loop can be coupled with the metal license plate, e.g., via inductive or conductive coupling. In this manner, the metal license plate can be configured to act as a resonator providing increased performance. | 6 |
BACKGROUND OF THE INVENTION
The invention relates to an anti-blocking agent comprising silicon dioxide or mixtures of silicon dioxide and zeolite and to a process for its manufacture.
Micronized silicic acid gels and molecular sieves (zeolites) are used to a great extent as anti-blocking agents in polymer films. Synthetic amorphous silica gels have a relatively large specific pore volume (usually called porosity) and accordingly deliver a larger number of particles (of a certain size) per gram than products with lower porosity (e.g. talc, chalk, natural silica gels such as diatomaceous earth). If these particles, which generally have diameters between 1 and 10 μm (Coulter Counter), are incorporated into polymer films in concentrations of the order of 0.1%, they produce microscopic surface deformations which prevent the complete contact of films lying on one another and facilitate separation of the films from one another (for example in the case of shopping bags) or the unwinding of film rolls. This is the "anti-blocking" effect. For the above reasons, micronized synthetic silica gels are more effective anti-blocking agents than products with low or no porosity.
In many cases, a lubricating agent is added to polymer films in addition to the anti-blocking agent. The lubricating agent is in most cases a fatty acid amide such as oleic acid amide or erucic acid and facilitates the sliding of the films over one another (sliding effect). The present anti-blocking agent reduces the effectiveness of the lubricating agent however, because the latter is adsorbed on the surface of the anti-blocking agent. As a result, some of the lubricating agent is not available on the film surface, where it is required for the desired sliding effect. Natural products have a very small surface of 0.1 to 0.5 m 2 /g compared with synthetic SiO 2 products having a surface of 300 to 600 m 2 /g. They adsorb less lubricating agent than for example silica gel, but have only a very small anti-blocking action as a result of the low porosity.
The anti-blocking action of synthetic silica gels is almost three times greater than that of products with a small surface, but unfortunately, synthetic silica gels adsorb lubricating agents. This means that a polyolefin film has for example to be provided with 0.3 wt. % of an anti-blocking agent having a small surface and 0.1 wt. % lubricating agent or with 0.1 wt. % anti-blocking agent comprising synthetic silicic acid and 0.15 wt. % lubricating agent in order to obtain the desired anti-blocking and sliding properties. This shows that the effectiveness of the lubricating agent is considerably reduced in the presence of synthetic silicic acid, i.e. approximately 50% more lubricating agent is required in order to obtain the same sliding effect or the same low friction coefficient.
Thus, although the traditional synthetic silicic acids are highly effective anti-blocking agents, the adsorption of lubricating agent is a problem, because
a) it makes it difficult to predict the ultimately obtainable effect of the lubricating agent in the film,
b) the higher quantity of lubricating agent increases the costs of film manufacture and
c) the required higher quantity of lubricating agent increases the extractable quantity of organic constituents, which is of importance as regards approval of the film for the packaging of foods.
According to EP-A-0 526 117 it is reportedly possible to offset the reduced lubricating agent effect by adding alkylene polyethers as "slip boosting agent", so that smaller quantities of lubricating agent suffice for the desired lubricant effect. However, this procedure has the disadvantage that other organic constituents must be added.
SUMMARY OF THE INVENTION
Compared with this, it is the object of the invention to provide an anti-blocking agent having a high anti-blocking action which avoids or greatly reduces the aforementioned disadvantages of the prior art as regards adsorption of lubricating agent, which can be dispersed in excellent manner in the polymer film material and thereby leads to clearer films (fewer flecks), treatment with an additive such as according to EP-A-0 526 117 not being necessary, the desired properties being achieved through optimum setting of the physical properties (pore volume, pore size and surface).
To achieve this object, an anti-blocking agent comprising silicon dioxide or mixtures of silicon dioxide and zeolite is proposed, which is characterized in that it has a bimodal pore size distribution.
A process for the manufacture of the anti-blocking agent according to the invention is also a subject of the invention, which is characterized in that a mixture of silicon dioxide of a certain pore size and silicon dioxide and/or zeolite with a different pore size is micronized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot of surface area vs. minimum pore size for an antiblocking agent of the invention.
FIG. 2 is a plot of surface area vs. minimum pore size for prior art antiblocking agent.
FIG. 3 is a plot of the pore size distribution for an antiblocking agent of the invention.
FIG. 4 is a plot of the pore size distribution for a prior art antiblocking agent.
FIG. 5 is a comparison of coefficient of friction vs. time after film extrusion for film containing the antiblocking agent of the invention and films containing prior art antiblocking agent or no antiblocking agent.
FIG. 6 is a comparison of blocking force vs. silica content for film containing the antiblocking agent of the invention and films containing prior art antiblocking agents.
FIG. 7 is a comparison of film haze vs. silica content for film containing the antiblocking agent of the invention and films containing prior art antiblocking agents.
DETAILED DESCRIPTION OF THE INVENTION
It was surprisingly found that when a mixture of two anti-blocking agents having different pore sizes is used, an anti-blocking agent is obtained whose overall properties are very much better than those of the two mixture constituents. It is particularly surprising that the anti-blocking effectiveness of the mixture does not decrease in accordance with the reduced average pore volume of the mixture. Rather, the anti-blocking effectiveness of the mixture is almost exactly as good as the traditional silicic acid anti-blocking agent having a pore volume of 0.9 to 1.2 ml/g. It was also unexpected that the particles of the mixture can be dispersed and distributed better in the films than is the case with traditional silicic acid anti-blocking agents. This again leads to considerably improved optical properties of the films, since the number of agglomerates in the films is lower. In some cases, a lower expenditure on energy is sufficient when using the anti-blocking agents according to the invention to obtain a film of the same optical quality, compared with using traditional silica gel anti-blocking agents (i.e. having monomodal pore size distribution).
The pore size distribution (to be more exact: pore diameter distribution) is represented by the distribution density curve:
pore volume density=f (pore diameter)
The pore volume density p(x) is obtained from:
p(x)=dP (x)/dx,
P being the specific pore volume, p the pore volume density and x the pore diameter. The pore size distribution is determined according to ASTM D 4641-88 using the automatic analysis device ASAP 2400 from Messrs. Micromeritics. As silicon dioxide has a hysteresis in the nitrogen isotherm, the adsorption curve is used. The integrated pore volume (up to 600 Å pore diameter) is the specific pore volume. The specific surface is measured with the same device by gas adsorption according to Brunauer, Emmett and Teller (BET) by multi-point measurement within the scope of the pore size distribution determination. Measurement is carried out according to DIN 66131.
A bimodal pore size distribution has two maxima (peaks) (see e.g. FIG. 3). The bimodality of the pore size distribution of the anti-blocking agent according to the invention can be determined in two ways, namely from the pore diameter distribution of the end-product according to the invention (as in FIG. 3) or by calculating the average pore diameter of the mixture components from the corresponding pore volumes and the corresponding surfaces according to Wheeler (A. Wheeler in P. H. Emmet (Editor), Catalysis, Vol. 2, Reinhold, N.Y., 1955, page 116).
In the case of the bimodal pore size distribution of the anti-blocking agent according to the invention, the first maximum is located in the pore size range<5 nm. The second maximum is located in the pore size distribution range>6 nm.
In the range of silica gels obtainable commercially, the following generally applies: gels having a smaller specific pore volume have a low pore size and a large specific surface, whilst gels with large specific pore volumes have a large pore size and a relatively small specific surface. This can be demonstrated with reference to the following examples:
______________________________________ Specific Average pore pore volume, size SpecificTrade name ml/g (Wheeler), nm surface, m.sup.2 /g______________________________________SYLOID AL-1 0.4 2.3 700SYLOBLOC 47 1.1 9.2 480______________________________________
The anti-blocking agent according to the invention represents a new type of anti-blocking agent with optimized properties. For this, it necessary that a relatively large proportion of the surface is located in pores which are so small that the additive molecules (e.g. fatty acid amides) are not able to enter, and that the overall porosity is nevertheless large enough to ensure a satisfactory anti-blocking effectiveness. According to the invention, an anti-blocking agent having large pores (e.g. average 9.2 nm) is accordingly combined with an anti-blocking agent having small pores (e.g. average 2.3 nm). The anti-blocking agent with the large pores delivers an adequate pore volume for the anti-blocking effectiveness. The majority of the surface is however to be found in the pores of the anti-blocking agent having small pores, with the result that the additive molecules cannot be adsorbed. FIGS. 1 and 2 show for example that the surface available in pores having a diameter of more than 10 nm is approximately 100 m 2 /g for a standard anti-blocking agent and only 40 m 2 /g for the anti-blocking agent according to the invention (silica gel).
The anti-blocking agent according to the invention delivers a considerably improved dispersibility and very clear polymer films. The anti-blocking effectiveness is practically the same as with traditional silica gels, but the adsorption of fatty acid amides is considerably reduced compared with traditional silica gels.
Traditional SiO 2 anti-blocking agents are micronized SiO 2 compositions with a pore volume of 0.9 to 1.2 ml/g. Products with a higher pore volume are difficult to disperse if standard incorporation devices are used. They are therefore not used in practice. Products with a smaller pore volume are better in terms of dispersibility, but show a clearly lower anti-blocking effectiveness. The anti-blocking agent according to the invention is advantageously produced from two anti-blocking agents in a mixture ratio of 2:8 to 8:2, whereby the two mixture components have different pore volumes. The pore volume of one anti-blocking agent should be 0.9 to 1.9 ml/g and that of the other 0.3 to 0.6 ml/g. The corresponding surfaces usually lie in the range from 250 to 500 m 2 /g and 500 to 900 m 2 /g respectively, so that the average pore diameters are 7.2 to 30.4 nm and 1.3 to 4.8 nm respectively. The two anti-blocking agents are preferably micronized together in a jet mill to an average particle size of 1 to 10 μm (Coulter Counter). The pore size distribution of the product obtained is bimodal, the surface is approximately 600 m 2 /g and the pore volume approximately 0.6 ml/g (see Example 1).
The pore size distributions of an anti-blocking agent according to the invention (silica gel) and of a traditional anti-blocking agent (silica gel) are shown in FIGS. 3 and 4 respectively.
Anti-blocking agents suitable according to the invention are micronized silica gels and precipitated silicic acids and zeolites. The latter are suitable as a component with a smaller pore diameter, for example 0.3, 0.4, 0.5 or 1 nm. Examples are sodium zeolites A, X and Y, partially or completely substituted with K or Ca. The polymer films in which the anti-blocking agent according to the invention is used preferably consist of polyethylene, polypropylene or linear polyester.
The anti-blocking agents according to the invention can be combined with lubricating agents for processing in polymer films, so that combined anti-blocking and lubricating agents are produced. Suitable as lubricating agents are amides of unsaturated C 18 -C 22 fatty acids and in particular oleic acid amide and erucic acid amide. Accordingly, the combined anti-blocking and lubricating agents advantageously consist of 20 to 80 wt. % of one or more amides of unsaturated C 18 -C 22 fatty acids and 80 to 20 wt. % of the bimodal anti-blocking agent according to the invention.
In another use form, which is particularly suitable in practice, the anti-blocking agent according to the invention or the combined anti-blocking and lubricating agent exists in the form of a master batch, i.e. it is incorporated already in a relatively high concentration into a polymer, in particular a polyolefin. The polymer is preferably the same polymer as that which also constitutes the film into which the anti-blocking agent or the combined anti-blocking and lubricating agent is to be incorporated. The concentration of the anti-blocking agent or the combined anti-blocking and lubricant agent in the master batch is generally 10 to 50 wt. %.
EXAMPLE 1
A silica gel with a pore volume of 0.46 ml/g (measured by nitrogen adsorption) and a BET surface of 802 m 2 /g (average pore size 2.3 nm) and a silica gel with a pore volume of 0.93 ml/g and a BET surface of 529 m 2 /g (average pore size 7.0 nm) were fed into a steam jet mill in a weight ratio of 50/50. A grinding pressure of 6 bar at a temperature of the superheated steam of 290° C. led to the desired particle size of 4 μm (Coulter Counter). The particle size distribution agreed with that of a micronized silica gel which had been prepared from only one of the two silica gels. The resulting pore volume was 0.62 ml/g and the resulting surface 610 m 2 /g. The pore size distribution was bimodal as shown in FIG. 3. As comparison, the pore size distribution of a silica gel having a pore volume of 0.93 ml/g (SYLOBLOC 45) is reproduced in FIG. 4.
EXAMPLE 2
Using an internal mixer, 0.2 wt. % silica gel and 0.2 wt. % oleic acid amide were incorporated into polyethylene (LD-PE) having a density of 0.924 g/cm 3 and a melt index of 1.5 g/10 min (190° C./2.16). As comparison, a sample was prepared which contained only 0.2 wt. % oleic acid amide.
Films with a film thickness of 1 mm were extruded from these materials in a laboratory extruder. The extrusion temperatures were 180° C. (cylinder) and 190° C. (die). The die had a width of 10 cm.
The dynamic friction coefficient of the extruded films was measured 1, 4 and 6 days after extrusion. Measurements were carried out with a device from the Davenport Company (Davenport Friction Tester) according to BS 2782 Method 311 A.
FIG. 5 shows that the sample containing the traditional silica gel SYLOBLOC 47 (pore volume 1.1 ml/g) and oleic acid amide has a higher friction coefficient than the samples containing a) only oleic acid amide and b) the silica gel according to the invention and oleic acid amide.
The silica gel prepared according to Example 1 had a pore volume of 0.62 ml/g and absorbed very much less oleic acid amide than silica gels having a larger pore volume. The silica gel particles lead to a micro-rough film surface and the friction coefficient of the samples containing the silica gel according to the invention and oleic acid amide is accordingly lower than that of the sample which contains only oleic acid (a sample of this type has a flat surface because no silica gel particles are present).
EXAMPLE 3
The dispersibility of the silica gel according to the invention was investigated several times. As comparison, a SYLOBLOC 45 standard silica gel anti-blocking agent and a SYLOBLOC silica gel having monomodal pore size distribution (pore volume 0.7 ml/g) were investigated.
a) The silica gels were mixed dry with polypropylene pellets (Novolen 1300, BASF). The quantities of silica gel were 0.2 and 0.5 wt. %. Flat polypropylene films were extruded from these mixtures (film thickness 50 μm). It should be pointed out that the extruder did not have a filter of any kind.
In the case of all films, the flecks (agglomerates) measuring more than 0.4 mm were counted. The area investigated was 0.012 m 2 . Whilst the number of flecks on using 0.5 wt. % of the silica gel according to the invention (Example 1) was 40, the samples with 0.5 wt. % SYLOBLOC 45 standard silica gel and silica gel with monomodal pore size distribution had more than 100 flecks.
b) The silica gels were incorporated into polypropylene using a twin-screw extruder in order to produce a master batch which contained 5 wt. % silica gel and 95 wt. % polypropylene. The master batch was then mixed with pure polypropylene pellets in order to establish an end concentration of 0.5 wt. % silica gel. Film extrusion and counting of the flecks was carried out as described under a).
The film containing the silica gel according to the invention had noticeably fewer flecks than films containing the other silica gels.
EXAMPLE 4
Different quantities of silica gel were incorporated into polyethylene (LD-PE) having a density of 0.924 g/cm 3 (500, 1000 and 2000 ppm). Films having a thickness of 40 μm were produced.
The extrusion conditions comprised a temperature of 160° to 170° C. (cylinder), 180° C. (die) and output of 10 kg/h.
The thus-obtained blown films were blocked artificially. For this, film samples measuring 10 x 7 cm 2 were placed in an oven at 60° C. for 3 hours. The films were exposed to a loading of 0.3 N/cm 2 . After the film blocking, the force required to separate two films was determined using a Davenport Film Blocking Tester.
It is evident from the results in FIG. 6 that the silica gel according to the invention according to Example 1 has almost the same anti-blocking effectiveness as a traditional SYLOBLOC 45 silica gel having a pore volume of 1.2 ml/g and monomodal pore size distribution, and a significantly improved anti-blocking effectiveness vis-a-vis a silica gel (A) having a pore volume of 0.7 ml and monomodal pore size distribution.
EXAMPLE 5
The haze at extruded flat polypropylene films having a thickness of 50 μm was measured according to ASTM D 1003. FIG. 7 shows that the silica gel according to the invention according to Example 1 produced considerably less film haze than the standard SYLOBLOC 45 silica gel and a silica gel (A) having the same pore volume but a monomodal pore size distribution. | An anti-blocking agent comprising silicon dioxide or mixtures of silicon dioxide and zeolite is described, which is characterized in that it has a bimodal pore size distribution, the first maximum of the bimodal pore size distribution being in the pore size range<5 nm and the second maximum of the bimodal pore size distribution in the pore size range>6 nm. The anti-blocking agent is obtainable by micronizing a mixture comprising silicon dioxide of a certain pore size and silicon dioxide and/or zeolite having a different pore size. It can be produced together with lubricating agent as a combined anti-blocking and lubricating agent. Incorporation of the anti-blocking agent or of the combined anti-blocking agent and lubricating agent into a polymer in the form of a master batch is preferable. In addition to a better dispersion and distribution of the anti-blocking agent particles in films and the improved optical properties associated therewith, the particular advantage of the anti-blocking agent according to the invention is that the adsorption of lubricating agent is avoided or greatly reduced, so that less lubricating agent can be used than in the prior art. | 2 |
INCORPORATION BY REFERENCE
This application claims domestic priority under 35 USC §119(e) based upon provisional patent application No. 60/836,214 filed on Aug. 8, 2006. The entire provisional application No. 60/836,214 is hereby incorporated by reference as if set forth verbatim into this patent specification.
SUMMARY OF THE INVENTION
The invention is a high-strength yet lightweight material composed of interconnected struts that typically form a tetrahedral lattice structure. Each strut of the interconnected struts has first and second ends spaced from one another along a longitudinal axis. The strut has a generally triangular cross-section at planes perpendicular to this longitudinal axis. In a preferred embodiment, the triangular cross section comprises an isosceles triangle, with a pair of base-angles approximating 55 degrees. It is important that the first and second ends of each strut are equivalent to one another to facilitate the assembly of the struts into a lattice structure of these interconnected struts.
Each strut has a vertex point positioned at an outermost point with respect to the longitudinal axis. The vertex point is positioned on a line within a plane that symmetrically divides the triangular cross-section, and is the intersection point of a plurality of planar polygonal faces.
The first and second polygonal faces share a common edge and angle outwardly toward the vertex from the upper edge of the triangular cross-section. These first and second faces, preferably triangles, are generally symmetric about the common edge. Third and fourth faces of the end portions of the strut angle outwardly and upwardly from a base of the triangular cross section toward the vertex point. Preferably, the third and fourth faces share a common edge extending from the vertex point to the base of the triangular cross-section of the strut.
A manifold comprising fluid ducts may pass through each strut. In a preferred embodiment, a duct passes from the first face of one end of the strut to the second face of the other end. Another duct may do just the opposite and criss-cross it.
Comparatively, another pair of ducts may cross from the third and fourth faces of the opposing ends as well. Of course, other arrangements of the manifold are possible, including making the entire strut hollow so that a manifold can be created by interconnecting the struts into a lattice structure. Fluid may be injected, forced or moved through the manifold in order to regulate the temperature of the material.
The lattice structure, of course, will create a material that comprises struts and voids therebetween. The material may be made solid by pouring a filler (such as fiberglass, epoxy, concrete, or the like) into the lattice to fill these voids thereby creating a solid material.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the lattice structure, according to the principles of the invention.
FIG. 2 shows a perspective view of an alternate embodiment of the lattice structure.
FIG. 3 shows a perspective view of another alternate embodiment of the lattice structure.
FIG. 4 shows a perspective view detailing a unique method that incorporates the inventive lattice structure.
FIG. 5 shows a side view isolating a strut that comprises the lattice structure.
FIG. 6 is an end view isolating a strut that comprises the lattice structure.
FIG. 7 is a plan view isolating the strut that comprises the lattice structure
FIG. 8 is a bottom view isolating the strut that comprises the lattice structure.
FIG. 9 is a plan view of isolating a second preferred embodiment of a strut that comprises the lattice structure.
FIG. 10 is a bottom view isolating a second preferred embodiment of a strut that comprises the lattice structure.
FIG. 11 is a bottom view isolating the strut that comprises the lattice structure.
FIG. 12 is a plan view of isolating a second preferred embodiment of a strut that comprises the lattice structure.
FIG. 13 is a bottom view isolating a second preferred embodiment of a strut that comprises the lattice structure.
FIGS. 14 and 15 are perspective views detailing how the struts interconnect to form a tetrahedral lattice structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 gives a perspective view of a first embodiment of the lattice structure, according to the principles of the invention. As shown, the lattice structure 10 comprises a plurality of interconnected struts 12 that form triangles within a plane, and extend to form a tetrahedral spatial structure. In selected planes, the struts 12 form triangular structures with space therebetween. It is well-known that triangular support structures provide very stable, durable support, and are likewise resistant to trauma. The instant design takes full advantage of this principle regarding triangles, and simultaneously generate a relatively lightweight lattice structure because much of the structure is open space.
FIG. 2 shows a perspective view of an alternate embodiment of the lattice structure 10 . The view shown in FIG. 2 shows a lattice structure 10 that forms the general shape of a tetrahedron. This embodiment of the lattice structure 10 , as in previously discussed embodiment, will comprise interconnected struts 12 that form tetrahedral shapes within the lattice structure 10 . Additionally, the tetrahedrally-connected struts 12 may interconnect to form any type of shape, including a planar structure (as in FIG. 1 ), or even a larger lattice that itself forms a tetrahedron, as depicted here in FIG. 2 .
FIG. 3 shows a perspective view of yet another alternate embodiment of the lattice structure 10 . In this embodiment, tetrahedrally-connected struts 12 are interconnected and formed to create a cylindrical lattice structure 10 . This lattice structure may also comprise a hollow cylinder (as shown in FIG. 3 ), or it may comprise a generally-solid cylindrical structure.
FIG. 4 shows a perspective view that details how the lattice structure 12 may be used as an internal structure to enhance the durability of a solid material. In this embodiment, the lattice structure 10 is positioned within a mold 41 , and material in molten or liquid form is poured into the mold. The material 43 can be any known material, such as fiberglass, polyurethane, plastic, or even concrete. It is found that the lattice structure 12 within any cured material will enhance the durability and make the material more resistant to trauma and wear.
FIG. 4 a shows an alternate perspective view of how the lattice structure 12 may be used as an internal structure to enhance the durability of a solid material. In this embodiment, material 43 is inserted into the lattice structure with an inserter 51 that is directed appropriately. Comparatively, FIG. 4 b shows another embodiment of how material 43 may be inserted into the structure 12 . In the alternate method depicted in FIG. 4 b , the inserter 51 comprises numerous hoses or ducts that can penetrate into the lattice structure to better direct and manage insertion and filling of the lattice structure with material 43 in a more uniform manner.
FIG. 5 isolates the strut 12 and provides a side view thereof. The strut 12 extends along a longitudinal axis L to a vertex point 14 at an outermost point of each end of the strut 12 . The first side 26 of the strut 12 is shown to bear a generally planar configuration, but other shapes and configurations are also within the scope of this invention. However, experimentation has shown that planar configurations are preferred for the ease of manufacture.
As shown in FIG. 5 , the start 12 has a pair of opposed ends that are generally equivalent one another. For example, the first end face 16 bears an equivalent shape with the fourth end face 22 on the opposite end of the strut 12 . Likewise, the fourth end face 30 is generally equivalent to the eighth end face 36 .
FIG. 6 isolates the end view of the strut so that the configuration of the end faces 16 , 18 , 30 , 32 becomes more clear. The strut 12 bears a generally uniform isosceles triangular shape having a base 24 and legs 26 and 28 . As shown, upper end faces 30 and 32 are adjacent the spine edge 27 that forms vertex of the isosceles triangle. Preferably, the angle at the spine edge is slightly greater than sixty degrees—approximately 70 degrees. The four end feces 16 , 18 , 30 and 32 share vertex point 14 . Typically, the vertex point 14 is on a line that forms the altitude of the isosceles triangular cross-section. In that regard, the plane containing the altitude also provides a line of symmetry; note that the upper end faces 30 , 32 are symmetric about the altitude just as lower end faces 16 , 18 are symmetric about the altitude as well. The lower end faces 16 , 18 form right-angle trapezoids sharing a common edge through the altitude of the isosceles triangular cross-section.
FIG. 7 shows an overhead, plan view that isolates the strut 12 . The strut 12 has first side 26 and a second side 28 that meet at spine edge 27 . The spine edge 27 terminates where it adjoins the upper end feces 30 , 32 at one end, and upper faces 34 and 36 at the other. From the view shown in FIG. 7 , the line defining spine edge 27 provides a line of symmetry for end faces 30 and 32 . This same line through the spine edge 27 also provides a line of symmetry for end faces 34 and 36 . Also, note that opposite upper end faces 32 and 34 are equivalent to one another, as are opposite end faces 30 and 36 .
FIG. 8 isolates the bottom view of the strut 12 . The strut 12 has a base 24 that extends in a generally planar fashion along the longitudinal axis L of the strut, and terminates at each end with lower end laces 16 , 18 at one end, and lower end faces 20 , 22 at the other. As shown in FIG. 8 , the base forms a hexagonal shape bearing first line of symmetry about a plane through the longitudinal axis L, and a second line of symmetry about a line orthogonal to the longitudinal axis L.
FIG. 9 shows an overhead and plan view of alternate embodiment of the strut 12 . Structurally and spatially, the view of strut 12 of FIG. 9 is equivalent to the overhead plan view shown in FIG. 7 . For example, the strut in FIG. 12 has sides 26 and 28 that meet at spine edge 27 . In that regard, the spine edge 27 terminates with upper end faces 16 and 18 at one end and upper end faces 34 and 36 at the other, just as the embodiment shown in FIG. 6 . However, a pair of ducts 44 , 46 pass through the interior of the strut 12 . Specifically, the duct 46 passes from a first upper end face 32 at one end and terminates at the third upper end face 36 on the other. Note that the faces 32 , 36 that are connected by duct 46 are on opposite sides of the line of symmetry that passes through the spine edge 27 .
Still referring to FIG. 9 , a second duct 44 passes from a second upper face 30 at one end of the strut 12 to the fourth upper face 34 at the opposite end of the strut 12 . Analogously, the second upper face 30 and the fourth upper face 34 (which are connected by duct 44 ) are on the opposite sides of the line of symmetry that passes through spine edge 27 . These ducts will criss-cross one another (and may intersect) at an interior point within the strut 12 . These ducts 44 , 46 will allow the struts 12 , when assembled into a lattice structure (as in FIGS. 1-4 ) to create a manifold that allows cooling fluid to pass therethrough. Of course, the entire strut itself may be entirely hollow, which could also enable fluid to pass therethrough, even when assembled into a complex lattice structure as previously shown.
FIG. 10 isolates a bottom view of another embodiment, similar to the embodiment shown in FIG. 9 in that this embodiment bears a pair of criss-crossing internal ducts 48 , 49 . A first duct 48 extends between a first lower end face 18 on one end of the strut 12 to a third lower end face 22 on the other end. Conversely, there is a second duct 49 that passes from a second lower end face 16 at one end to a fourth lower end face 20 at the other. These ducts 48 , 49 will criss-cross one another (but not necessarily intersect) within an interior of the strut, and will allow the struts 12 , when assembled to create a manifold that allows cooling fluid to pass through a network of struts.
FIG. 11 represents a plan view of alternate embodiment of the strut 12 . In this embodiment, the interior portion of the strut is hollow; however, the remaining parts of the strut 12 are analogous. For example, the start of FIG. 11 includes a first side 26 that extends along a longitudinal axis L and terminates in an upper spine edge 27 .
FIG. 12 shows an end view of a hollow embodiment of the start 12 . In this view, the sides 26 , 28 and base 24 form a generally triangular configuration that encloses a hollow void V. The hollow configuration of FIG. 12 , of course, eliminates the end faces that are viewable in FIG. 6 . Conversely, the embodiment of FIG. 12 also eliminates the vertex point 14 that is shown in FIG. 6 as well.
FIG. 13 shows a bottom view of the hollow embodiment of the strut 12 . As shown the base 24 that forms an elongate hexagon that extends along longitudinal axis L and terminates with a triangular configuration adjacent the opening for void V. The void V allows cooling fluid to pass through the strut; when interconnected into a lattice structure (as in FIGS. 1-4 ), the void V allows cooling fluid to circulate through the entire lattice structure. Additionally, other devices or items, such as sensors, wiring, pumps, filters, motors, electronic devices, or the like may be positioned within the voids V. These devices may be positioned exterior the struts and within the lattice structure.
FIG. 14 shows a perspective view of three struts 12 . As shown, the lower end face 22 of one strut abuts and adjoins a lower end face 22 . These respective lower end faces 16 , 22 are formed so that they are generally identical and fit neatly onto one another. To wit, note that points a, b, and c of lower end face 18 of a first strut will meet and join with points a′, b′ and c′ of lower end face 16 of an adjacent strut. When these faces 16 , 22 adjoin as shown, an angled configuration formed to receive another strut 12 (not shown) will be formed by faces 18 of one strut and 20 of its adjoining strut (not viewable in FIG. 14 ; see FIG. 8 ) The ends of the struts are formed such that the end faces 16 , 18 , 20 , 22 will neatly fit into the angled configuration to form a tetrahedral configuration in three dimensions.
FIG. 15 shows a perspective view detailing how three struts 12 will fit together into a generally planar triangular configuration. The triangular configuration comprises three struts 12 adjoined at respective lower faces (see FIG. 11 ). In this configuration, the upper faces 30 , 32 , 34 , 36 of each strut are open to adjoin an adjacent triangular configuration so that a lattice structure of interconnected tetrahedrons will be formed (see FIGS. 1-4 ).
As shown in FIG. 15 , when the three struts are assembled in this manner, the upper faces 30 , 32 , 34 ,and 36 meet so that the vertex point 14 of each strut 12 abuts to form a single vertex. The spine edge 27 of each strut 12 faces outwardly from the triangular configuration, while the base 24 faces toward the interior of the triangular configuration.
Having described the invention in detail, it is to be understood that this description is for illustrative purposes only. The scope and breadth of the invention shall be limited only by the appended claims. | The disclosure depicts a high-strength yet lightweight material composed of interconnected struts that typically form a tetrahedral lattice structure. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority from U.S. Provisional Application No. 60/450,033 filed Feb. 26, 2003.
FIELD OF THE INVENTION
[0002] The present invention relates to the optical testing of light-emitting components and, more particularly, to a test module which may be used in conjunction with conventional automatic test equipment to optically test light-emitting components.
BACKGROUND OF THE INVENTION
[0003] Electronic assemblies are built with a multitude of light-emitting components, primarily light emitting diodes (LED's), to indicate functions, or faults occurring on the assemblies. In addition to light, information on the nature of the operations of faults on these assemblies is conveyed by the color emitted by the devices. Light emitting diodes are available in colors covering the entire visible spectrum as well as white.
[0004] Various methods have been implemented to verify the correct operation of these light-emitting components, from test sequences where human verification is used, to photo detectors employed to perform the tests automatically.
[0005] Human verification is slow and unreliable. While photodetectors can easily verify that light is present, validation of the correct color has become extremely important. Photodetectors employing narrow bandpass color filters have been employed to test for the proper emitted wavelength, with limited success, since variations in output levels of the photodetector cannot discriminate intensity from colors approaching the edge of the passband. This becomes critical in the very narrow color bands in the visible spectrum.
[0006] In addition, these implementations require that each photodetector be customized for the particular wavelength of the light-emitting component under test, adding lead time and expense to their use. Current photodetector solutions are available in various configurations, some having the detector itself mounted near the light-emitting component, where others use fiber optic cable to collect the light and present it to a remotely mounted photodetector. Consequently, a need exists for a test module for automated test equipment to test light emitting components which addresses the problems associated with prior test apparatus.
SUMMARY OF THE INVENTION
[0007] The present invention provides a test module and a method to accurately test the operation of light-emitting devices described, and provides parametric values for color and luminous intensity, which can be compared automatically to expected values. The test module contains a sensor or plurality of sensors, each of which contains three photodetectors. The three photodetectors are individually filtered to pass the red, green, and blue portions of the visible spectrum.
[0008] When the light from the photo-emitter to be tested is presented to this three-color sensor, the individual outputs of the detectors divide the light into levels of red, green, or blue component. After signal conditioning the individual color components are converted to digital values, then presented to a preprogrammed microcontroller.
[0009] The microcontroller is programmed to use the combination of all of the color component values to determine the luminous intensity and the ratios of the individual color values to algorithmically match the monochromatic input color to wavelength, based on CIE color matching values. Additional tests are made to determine if the color components are all above a preset threshold, indicating the presence of a white color source.
[0010] The microcontroller presents the wavelength and intensity values to digital to analog converters, which produce an analog wavelength value linearly scaled to the visible spectrum, 380 nanometers through 700 nanometers, and an intensity output linearly representing luminous intensity. In the case of white, a voltage value above the visible values will be output to indicate the presence of white light. Light levels below a preset low limit will force both the color and intensity outputs to zero volts.
[0011] These voltage values are read by the automatic test system and compared against expected values to determine if the correct light-emitting component has been installed and is operating correctly in the assembly.
[0012] The test module described provides a low cost and easily implemented method of performing parametric color tests on light-emitting devices. It requires no calibration or setup once installed in the test apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a schematic perspective view of the light testing module of the present invention;
[0014] [0014]FIG. 2 is a detailed view of the test probe of the module of FIG. 1;
[0015] [0015]FIG. 3 is a schematic view of the test module of FIG. 1;
[0016] [0016]FIG. 4 is a CIE color matching chart; and
[0017] [0017]FIG. 5 is a CIE color ratio matching chart.
DETAILED DESCRIPTION
[0018] Referring to FIG. 1, the light testing module 10 of the present invention consists of an assembly of sensors 12 to which the light from the emitter under test is presented. In the implementation shown, the light is piped to the sensors using fiber optic cable(s) 14 connecting to the sensors using plastic fiber connector(s) 16 . The sensors are located under a light shield 18 to prevent entrance of ambient light. Electronics 20 on the assembly condition the sensor signals, process the red, green, and blue components of the light, and produce wavelength and intensity outputs. Additional electronics 22 is provided to select one of n sensors on the module corresponding to the light-emitter currently under test. A connector 24 is provided for wiring the test module to automatic test apparatus to provide power for operation, one of n sensor selection, and output values. All of the components of the test module 10 can be mounted on a printed circuit board 26 or other suitable device.
[0019] [0019]FIG. 2 is a detail view of the termination of the fiber optic cable 14 at the light emitting device 28 to be tested. An end of the flexible plastic optical fiber 14 is encased in a rigid tube 30 to provide pointing accuracy to the device under test 28 mounted on a printed circuit board 32 . The fiber optic cable is cut flush with the end of the tube 30 , and held in position using adhesive backed heat shrink tubing to hold the fiber in position in the tube. The supporting tube is mounted rigidly, preferably by an adhesive 34 , to a plate 36 to provide centering of the assembly at the optical center of the device under test 28 , as well as providing a minimal spacing from the device to prevent damage to the fiber or device under test. A connector 38 is positioned on an end of the tube 30 . The numerical aperture (acceptance angle) of the optical fiber is such that a portion of the emitted light is collected by the fiber, dependent on the viewing angle of the light-emitting device under test, and the spacing of the fiber from the light-emitting device. Since color determination is accomplished using ratios of the primary colors, the percentage of the total light collected is not critical to the measurement.
[0020] While this particular implementation uses fiber optics to couple the light, alternatively, similar modules could be implemented where the light sensor is mounted at the light-emitter under test, and electrically connected to the electronics on the test module for processing.
[0021] Referring to the schematic in FIG. 3, the individual color photodiodes 40 a , 40 b and 40 c which comprise the sensors 42 are amplified 44 then selected by an analog multiplexer 46 . The analog signals are then digitized by the analog to digital converter 48 . Two digital to analog converters 50 and 52 convert the calculated values of wavelength and intensity from the microprocessor 54 to analog values which can be read back to the automatic test apparatus 56 for pass/fail comparison.
[0022] The preprogrammed microprocessor 54 performs calculations to determine intensity, and wavelength of the incoming light. Luminous intensity is calculated as a function of the total energy captured by the red, green and blue photodiodes, factored by the preconditioning and equalization which has been done. First, tests are run to determine if sufficient light intensity is present to process. Below the present limit, the processing will terminate, and zero volts programmed to both the intensity and wavelength analog to digital converters to indicate no useable signal is present.
[0023] If the low limit tests pass, tests are then performed to check for equality of all three color components for white light determination. If the red, green, and blue components are equal within a preset percentage color calculations are skipped, and the wavelength output value is set to a predetermined output voltage level which indicates a white source is present.
[0024] If the test indicates the light is monochromatic, the color processing is run, first determining the order of the color by decreasing magnitude. Based on this order, sets of algorithms to calculate the wavelength are called. These algorithms calculate the wavelength by mathematical operations which convert the red, green, and blue magnitudes into wavelength based on the CIE color conversion values for human perception of color, as shown in the graph of FIG. 4.
[0025] The chart shown in FIG. 5, shows the ratio of the red, green and blue color mix throughout the visible range. These ratios alternatively are calculated based on the levels present at the sensors, and used as an index into lookup tables contained in the microprocessor memory. These tables correlate the ratios of red, green, and blue directly into the equivalent wavelength in nanometers. The wavelength is converted to a scaled voltage, which is then output by the digital to analog converter.
[0026] Once the wavelength is determined, a digital value is output to the digital to analog converter, which represents a direct voltage match to the calculated wavelength. For instance, 550 nanometers would output 550 milivolts, or a multiple of that value, to make the voltage more readable by the automatic test system.
[0027] Additional inputs 58 to the module are provided for digital selection of the sensor to be addressed, as well as power to run the module.
[0028] The sensor or sensors are capable of detecting the content of red, green, and blue or the complements cyan, yellow and magenta, to allow for the weighing of the individual colors to determine the wavelength of an incoming beam. The sensor can be a monolithic tricolor sensor, or individual filtered photodiode sensors with the optics to disperse the light equally across the three sensors. The colors are not limited to three and can be any number or color, required to effectively differentiate the incoming wavelength. The test module has the capability of selecting the individual sensor, the processing capability to calculate the wavelength from the levels of the sensed colors, and an output interface to present the wavelength data to the automatic test equipment in a digital or analog form.
[0029] In one embodiment, the multi-color sensor and amplification or a plurality of sensors and amplifiers are mounted remotely, at the light emitting-device under test, and electrically connected to the remainder of the electronic processing. Alternatively, the multi-color sensor or a plurality of sensors can be mounted with the processing circuitry, for use with fiber optic cables used to collect the light from the light-emitting device under test and transmit the light signals to the sensors. The test module uses a predefined set of color ratios based on standard color matching tables, modified by sensor response, to determine wavelength by comparing the color ratios of the incoming light irrespective of the absolute values. The test module which provides a calculated wavelength output, based on the proportion of the content of colors detected in the light output of a monochromatic emitting device.
[0030] The test module also determines a white source from a light-emitting device when all of the color sensor levels contribute equally to total input. The test module converts the input light to an analog signal scaled directly from nanometers to milivolts or a multiple thereof throughout the visible spectrum of 380 nm to 700 nm, and uses a unique voltage level in excess of the range of visible spectrum converted voltages to denote the detection of a white source. | A test module used to verify the correct placement of light-emitting devices on electronic assemblies, by performing color and luminous intensity tests on these devices. The module includes one or a number of color sensitive photodiodes, which when exposed to light coupled from the emitter under test, will accurately measure the intensity, as well as the true color emitted by the device. The test module outputs analog signals, one directly proportional to the intensity, a second voltage proportional to the spectral wavelength of the device under test. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This new application is a continuation application U.S. patent application Ser. No. 11/114,184 filed on Apr. 26, 2005 now U.S. Pat. No. 7,435,082, currently, which is a continuation-in-part application of U.S. patent application Ser. No. 10/321,721 filed on Dec. 18, 2002, now U.S. Pat. No. 6,883,490, which is a continuation of U.S. application Ser. No. 09/954,195 filed on Sep. 18, 2001, now abandoned, which is a continuation of U.S. application Ser. No. 09/501,788 filed on Feb. 11, 2000, now U.S. Pat. No. 6,289,868. These prior applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for improving fuel burners in furnaces by using a plasma ignition system.
2. Description of the Related Art
As described in applicant's prior applications listed above and incorporated herein by reference, there are numerous problems with the combustion process for diesel engines. None of the prior art references disclosed an apparatus that will allow for the initiation of combustion for all of the fuel as it is injected into the combustion chamber followed by the maintenance of the combustion process to its completion in the manner described therein.
Also, fuel burner technology for furnaces usually relies upon a simple electrical arc discharge ignition system, usually positioned to one side of the fuel spray coming out of the nozzle. In some cases the ignition system is as primitive as a simple pilot light for flame ignition.
Although these oil burner ignition systems are simple, reliable, and cheap they have absolutely no fuel treatment capability. This lack of point of use fuel treatment results in four serious limitations:
1. Less than optimal fuel efficiency as a result of incomplete combustion;
2. Pollutant emissions as evidenced by the production of oxides of nitrogen (NO x ), carbon monoxide (CO), hydrocarbons, and particulates (soot) that are observed in the exhaust output;
3. Unstable combustion when dealing with fuel that has been contaminated by water; and
4. Imposed limitations on the fuel oil weight used in a given burner design.
To date, a variety of methods have been employed to improve the efficiency of and reduce pollution from fuel oil burners used in furnaces and similar systems. Higher fuel pressures, smaller fuel nozzle orifice sizes, different fuel nozzle configurations, improved fuel/air mixing arrangements, fuel pre-heating, and improved heat exchanger systems have provided for improved fuel efficiency and some reduction in pollutant emissions.
None of these approaches has the effect of chemically altering the fuel on its molecular level.
As best understood, the present invention chemically alters the fuel in the combustion process directly at the fuel's point of use, changing the fuel's chemical structure right after it leaves the fuel oil burner's nozzle as it enters the combustion area. This enhances the fuel combustion process significantly. These benefits of the present invention are complimentary with and in addition to those realized by the previously mentioned methods currently in use.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide an apparatus and method for assuring the immediate and complete combustion of any hydrocarbon fuel sprayed into the combustion area of furnaces and similar systems.
It is a further object of the present invention to make it possible to easily retrofit this apparatus to existing furnaces and also to provide a method for assuring the complete combustion of any hydrocarbon fuels in the existing fuel burners.
An area of ionizing electrical energy, effectively an electrical catalyst, (for purposes of illustration, it is referred to as a “plasma ball” or “ring-of-fire”) is created inside the combustion area directly in front of the fuel nozzle. The placement of this plasma ball is critical in that all of the fuel must pass through the plasma ball as it enters the combustion area.
Plasma created between the electrodes of the plasma ball generator of the present invention may not be perfectly spherical in shape. The term “plasma ball” or “ball of plasma” as used herein, includes a spherical shaped plasma as well as other polygonal shapes, such as a partially flattened sphere or an elongated hemisphere. When the plasma discharge is operated in still air with the electrodes placed closely together the shape of the discharge, while being close to spherical to the naked eye, is more accurately an ellipsoid. When the plasma discharge is being put to work, the movement of air and fuel through the plasma ball distorts it further from the ellipsoid shape to a shape similar to a tee-pee with the pole ridges marking the electrode locations. As long as the plasma discharge is vigorous, the change in shape does not have a significant effect on the performance of the plasma.
Plasma is defined in the world of physics as a state of matter where the electrons that normally orbit the nucleus of an atom are instead dissociated from the nucleus. For the purposes of the present invention, it is unnecessary and inefficient to create pure plasma in which all of the electrons of all of the atoms are separated from all of the nuclei. The partial plasma created by the present invention strips off enough electrons to do what needs to be done for effective fuel treatment to take place.
These outer electrons are referred to as outer valence electrons. As best understood, these are the electrons that the “Plasma ball” created by the present invention is adept at removing. By having the correct shared outer electrons stripped away from the carbon atoms of the fuel molecules, these fuel molecules are broken down into shorter chain hydrocarbon fuel molecules such as, but not limited to methane, ethane, propane, butane, and pentane that are well known to burn much cleaner than almost all longer chain hydrocarbons.
This treatment of the fuel using the plasma ball ignition system also does other functions. It is believed that in addition to breaking down the fuel molecule into shorter chain hydrocarbons, it also puts an electrical charge onto each shorter chain hydrocarbon molecule. The effect of this electrical charge on the shorter chain hydrocarbon molecules is to increase its reactivity to oxygen dramatically. All that is needed for the shorter chain hydrocarbon molecules to ignite is for them to come into contact with oxygen.
The same molecular dissociation that breaks fuel oil molecules down also enables oil burners equipped with the present invention to deal with water contamination of the fuel with ease. When water mixed with the fuel passes through the “Plasma ball” it is believed to be electrolyzed into hydrogen and oxygen and then the hydrogen ignites and burns with the rest of the fuel without interfering with the overall combustion stability.
Both the chemistry of the fuel and the combustion process itself are completely changed by the “Plasma ball” point of use fuel treatment method and apparatus when utilized in a hydrocarbon fuel burner. It is believed to act as an electrical catalyst which greatly promotes the immediate and complete combustion of all of the fuel resulting in the following advantageous effects:
1) Greater fuel efficiency as a result of earlier completion of combustion thus allowing more time for heat transfer from the combustion gases to the heat exchanger wall.
2) Greater fuel efficiency than available from the present technology oil burners by burning completely those hydrocarbon components usually coming out of the exhaust flue as hydrocarbon emissions such as carbon monoxide, particulate matter, soot, and others.
3) Reduced hydrocarbon pollutant emissions as a direct result of complete combustion of all of the fuel.
4) The ability to greatly reduce pollutant emissions of oxides of nitrogen by making possible the much more aggressive utilization of exhaust gas recirculation without the loss of combustion efficiency.
5) The ability to maintain stable combustion when using fuels contaminated with water.
6) The ability to effectively and efficiently use heavier weight fuel oils that cost much less due to the present invention's ability to convert these lower quality fuels into much easier to combust compounds at the point of use.
The efficacy of the “Plasma ball” point of use fuel treatment and ignition system is evidenced by the empirical observations made during a series of side-by-side comparative tests. For this testing program, a Riello model 40F10 oil burner was retro-fitted with the plasma ball point of use fuel treatment system and installed in a furnace heating a commercial building and compared to exactly the same furnace and oil burner setup next to each other under the same conditions at the same time. Fuel efficiency was improved on average 7.6% with over-all pollutant emissions reduced between 25 to 35%, depending on the specific pollutant. Earlier testing done on a home heating furnace with a retrofitted Beckett oil burner according to the present invention had the result of showing no detectable particulates and a carbon monoxide level below that which could be detected by the testing equipment being used.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will be clearly understood from the following description with respect to the preferred embodiment thereof when considered in conjunction with the accompanying drawings and diagrams, in which:
FIG. 1 is a cross sectional side view of the injector/igniter apparatus of the present invention installed in an engine cylinder head.
FIG. 2 is a cross sectional side view of the injector/igniter apparatus of the present invention installed in an engine cylinder head with fuel being injected into the combustion chamber.
FIG. 3A is an enlarged side view of the lower end of the injector/igniter apparatus that extends through the cylinder head.
FIG. 3B is an enlarged bottom view of the injector/igniter apparatus.
FIG. 3C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 3A .
FIG. 3D is an enlarged perspective view of the injector/igniter apparatus.
FIG. 4A is an enlarged side view of the injector/igniter apparatus with the Ring-of-Fire shown in operation.
FIG. 4B is an enlarged bottom view of the injector/igniter apparatus with the Ring-of-Fire shown in operation.
FIG. 4C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 4A .
FIG. 4D is an enlarged perspective view of the injector/igniter apparatus with the Ring-of-Fire shown in operation.
FIG. 5A is an enlarged side view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 5B is an enlarged bottom view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 5C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 5A with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 5D is an enlarged perspective view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a pintle type of fuel injector.
FIG. 6A is an enlarged side view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 6B is an enlarged bottom view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 6C is an enlarged side view of the injector/igniter apparatus rotated by 90 degrees from the view presented in FIG. 6A with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 6D is an enlarged perspective view of the injector/igniter apparatus with the Ring-of-Fire shown in operation and with fuel being injected by a hole type of fuel injector.
FIG. 7A is a cross sectional side view of the injector/igniter apparatus of the present invention.
FIG. 7B is a top view of the injector/igniter apparatus of the present invention.
FIG. 7C is a bottom view of the injector/igniter apparatus of the present invention.
FIG. 8A is a cross sectional side view of the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 8B is a top view of the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 8C is a bottom view drawing of the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 9 is a block diagram of the signal generation circuit portion of the present invention.
FIG. 10A is a timing signal diagram of the square-wave signal created by the square-wave generator in the signal generation circuit of the present invention.
FIG. 10B is a timing signal diagram of the six sequential signals created by the signal divider circuit in the signal generation circuit of the present invention.
FIG. 10C is a timing signal diagram of the six overlapped sequential signals created by the signal overlap circuit in the signal generation circuit of the present invention.
FIG. 11 is a schematic of one of the high voltage discharge circuits of the present invention.
FIG. 12 is a diagram depicting all six high voltage discharge circuits attached to the ceramic sleeve portion of the injector/igniter apparatus of the present invention.
FIG. 13 is a side view of an entire furnace system with an oil burner equipped with the plasma point of use fuel treatment and exhaust gas recirculation system according to another embodiment of the present invention.
FIG. 14 is an enlarged side view of an oil burner fuel spray nozzle and igniter assembly removed from the burner air tube for clarity.
FIG. 15 is a side view of an oil burner equipped with the nozzle and igniter assembly of the present invention with the air tube partially cut away for clarity.
FIG. 16 is an enlarged front end view of the plasma electrode tips arrayed around the fuel spray nozzle with the flame retention plate in place according to the present invention.
FIG. 17 is a front end view of the plasma electrode tips arrayed around the fuel spray nozzle with the flame retention plate and electrode tip insulators removed for clarity.
FIG. 18 is a schematic of one of the improved high voltage discharge circuits that supply a multi-frequency high voltage output to one electrode of the nozzle and igniter assembly of the present invention.
FIG. 19 is a diagram depicting a signal generation circuit and six high voltage discharge circuits that produce the multi-frequency high voltage outputs that supply the electrodes of the nozzle and igniter assembly in a fuel burner according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described in further detail in connection with illustrative preferred embodiments for improving combustion in a direct injected internal combustion engine enabling the engine to achieve better fuel economy, reduced pollutant emissions, and more power. Within the scope of the present invention, this system could be applied to gas turbines and to reciprocating internal combustion engines that are direct injected of either the 2-stroke or the 4-stroke type that have been designed for use with any type of combustible fuel including gasoline, diesel or jet fuel.
Referring to FIG. 1 , the present invention is shown mounted in a cylinder head 15 of a diesel engine. An engine block 11 has placed inside it a piston 13 and mounted on top of the engine block 11 is the cylinder head 15 . A combustion chamber 17 is located inside the area surrounded by the engine block 11 , the piston 13 , and the cylinder head 15 . Passing through the cylinder head 15 is a fuel injector 21 that has its lower body surrounded by a ceramic sleeve 23 . A fuel inlet 25 attached to the upper portion of the fuel injector 21 has a fuel passageway 19 that allows fuel to travel to a fuel injection nozzle 27 . This fuel injection nozzle 27 protrudes into the inside of the combustion chamber 17 .
A plurality of embedded wires 29 travel from high voltage terminals 31 mounted on the ceramic sleeve 23 outside and above the cylinder head 15 through the length of the ceramic sleeve 23 including substantially parallel to the lower portion of the fuel injector 21 . These embedded wires 29 extend into the combustion chamber 17 as electrodes 33 . In this embodiment, there are six electrodes 33 arrayed around and below the fuel injector nozzle 27 inside the combustion chamber 17 . All six electrodes 33 are individually connected to high voltage terminals 31 by their own embedded wire 29 .
Referring to FIG. 2 , pressurized fuel is shown entering the fuel injector 21 through the fuel inlet 25 , down fuel passageway 19 , and then out of the fuel injector nozzle 27 into the combustion chamber 17 producing a fuel injection spray pattern 37 . While this is happening, a high voltage discharge 35 occurs between all of the tips of the six electrodes 33 inside the combustion chamber 17 , with the fuel injection spray pattern 37 passing right next to, or through the high voltage discharge 35 . The power for the high voltage discharge 35 that occurs between the six electrodes 33 is produced by a set of six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 (discussed in detail with reference to FIGS. 11 and 12 ).
A set of six spark plug type high voltage wires 39 , 41 , 43 , 45 , 47 and 49 connects on one end to the set of six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 . The other end of the set of six spark plug type high voltage wires 39 , 41 , 43 , 45 , 47 and 49 have an externally insulated connector 32 that secures and protects the connection to the six high voltage terminals 31 mounted on the upper portion of the ceramic sleeve 23 . This set of six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 is controlled by a signal generation circuit 63 which has its position in the system discussed in connection with FIG. 12 and has its operation discussed in detail in connection with FIG. 9 .
FIG. 3A is a side view of the lower portion of the ceramic sleeve 23 that extends through the cylinder head 15 into the combustion chamber 17 . The fuel injection nozzle 27 at the end of the fuel injector 21 and electrodes 33 are on the end of the ceramic sleeve 23 that faces into the combustion chamber 17 .
FIG. 3B shows the only part of the present invention that is actually exposed to the inside of the combustion chamber 17 . The six electrodes 33 are arranged in a circular manner around the fuel injection nozzle 27 .
FIG. 3C shows the same piece of the present invention that is illustrated by FIG. 3A with the difference being that the image was rotated by 90 degrees in order to clarify the shape and position of the electrodes 33 on the end of the ceramic sleeve 23 .
An oblique perspective of the lower portion of the ceramic sleeve 23 further illustrates the placement relationship of the fuel injector nozzle 27 to the electrodes 33 in FIG. 3D .
FIGS. 4A , 4 B and 4 C provide the same set of views as FIGS. 3A , 3 B and 3 C the inclusion of the operation of the high voltage discharge 35 . This gives further clarification of the placement of the high voltage discharge 35 upon the electrodes 33 that are arrayed around the fuel injector nozzle 27 on the end of the ceramic sleeve 23 that faces the combustion chamber 17 . This combustion chamber 17 could, within the scope of the present invention, be installed in any of a variety of engine types to include gas turbines as well as reciprocating 2-cycle and 4-cycle diesel or gasoline direct injected internal combustion engines.
FIG. 4D also shows the same oblique perspective view of the lower portion of the ceramic sleeve 23 as shown in FIG. 3D with the inclusion of the high voltage discharge 35 occurring between the six electrodes 33 . Other numbers of electrodes to create the Ring-of-Fire are possible. Also, the Ring-of-Fire is schematically illustrated in these figures since it is difficult to illustrate completely.
FIGS. 5A , 5 B, 5 C and 5 D show the lower portion of the ceramic sleeve 23 as shown in FIGS. 4A , 4 B, 4 C and 4 D with the inclusion of fuel being injected by a fuel injector 21 . The fuel injection spray pattern 37 of a pintle type of the fuel injector nozzle 27 places a cone of injected fuel centered to the high voltage discharge 35 that occurs between the electrodes 33 inside the combustion chamber 17 . This insures complete combustion initiation of all of the fuel as it is injected.
FIGS. 6A , 6 B, 6 C and 6 D show the lower portion of the ceramic sleeve 23 as shown in FIGS. 5A , 5 B, 5 C and 5 D. The difference is that this time the fuel injector 21 has a fuel injector nozzle 27 of the hole type. The hole type fuel injector nozzle 27 produces a fuel injection spray pattern 37 that has a set of lobes. Each lobe sprays directly next to or through the high voltage discharge 35 thus insuring complete combustion initiation of all of the fuel as it is injected into the combustion chamber 17 .
Referring to FIG. 7A , the fuel injector 21 is installed inside the ceramic sleeve 23 . When fuel injection is taking place, a fuel injector pump (not shown) sends pressurized fuel to the fuel inlet 25 of the fuel injector 21 in a manner known in the art. The pressurized fuel travels through fuel passageway 19 to the fuel injector nozzle 27 that injects the fuel into the combustion chamber 17 . The ceramic sleeve 23 surrounds the lower portion of the fuel injector 21 .
The upper end of the ceramic sleeve 23 that is above the cylinder head 15 has six high voltage terminals 31 that are connected to six embedded wires 29 that extend from the top to the bottom of the ceramic sleeve 23 . The lower ends of the six embedded wires 29 extend from the bottom of the ceramic sleeve 23 into the combustion chamber 17 as six electrodes 33 . These six electrodes 33 are positioned such that their tips are arranged so that they define a hexagon inside the combustion chamber 17 around and below the fuel injector nozzle 27 . This placement is important to insure that the fuel injection spray pattern 37 from the fuel injector nozzle 27 must pass in close proximity to or through the high voltage discharge 35 that occurs between the tips of the electrodes 33 .
FIG. 7B shows a top view of the fuel injector 21 mounted through the ceramic sleeve 23 with the placement of the six high voltage terminals 31 clearly shown.
FIG. 7C is a view from the combustion chamber 17 looking up at the face of the ceramic sleeve 23 and at the tip of the fuel injector 21 with the fuel injection nozzle 27 in the center of the six electrodes 33 .
FIGS. 8A , 8 B and 8 C are similar views as FIGS. 7A , 7 B and 7 C without the fuel injector 21 being shown to further clarify the positions of the high voltage terminals 31 , the embedded wires 29 and the electrodes 33 .
FIG. 9 shows the signal generation circuit 63 in detail. The signal generation circuit 63 controls the high voltage generation circuits 51 , 52 , 53 , 55 , 57 , 59 and 61 . The signals mentioned in this discussion are shown in detail by FIGS. 10A , 10 B and 10 C.
The signal generation circuit 63 has its overall output controlled by an engine timing signal source 65 that turns it on and off through an engine timing signal transmission line 67 . The engine timing signal source 65 controls the signal generation circuit 63 so that at the appropriate time, at or before fuel injection is to take place, the high voltage discharge 35 is initiated. The engine timing signal source 65 keeps the high voltage discharge 35 going for as long as necessary to ensure complete combustion of all of the fuel and air mixture inside the combustion chamber 17 .
The signal generation circuit 63 has within it a square-wave generator circuit 69 that sends through a square-wave signal transmission line 71 , a square-wave signal 73 to a signal divider circuit 75 . The square-wave generator circuit 63 is based on a 555 timer integrated circuit set up to operate as an astable multi-vibrator circuit producing a square-wave signal between 0 and 5 volts at a frequency between 5 and 30 kilo-hertz.
The signal divider circuit 75 divides the square-wave signal 73 into a set of six sequential signals 89 , 91 , 93 , 95 , 97 and 99 , as shown in FIG. 10B , that are sent through a set of six sequential signal transmission lines 77 , 79 , 81 , 83 , 85 and 87 to a signal overlap circuit 101 . The signal divider circuit 75 that divides the square-wave signal 73 into a set of six sequential signals 89 , 91 , 93 , 95 , 97 and 99 is based on the 4017 decade counter integrated circuit.
The signal overlap circuit 101 in turn generates a set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 , as shown in FIG. 10C , and then sends these signals through a set of six overlapped sequential signal lines 103 , 105 , 107 , 109 , 111 and 113 to a signal line driver circuit 127 . The signal overlap circuit 101 uses a bank of twelve 1N4004 diodes to generate the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 shown in FIG. 10C .
The signal line driver circuit 127 is activated only when the enable signal from the engine timing signal source 65 , brought in by the engine timing signal transmission line 67 and it allows the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 to go through the signal line driver circuit 127 . The signal line driver circuit 127 uses a 74HCT541 integrated circuit to act as a “gate” to the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 .
It is within the scope of the present invention to have this engine timing signal source 65 be as simple as a cam-shaft position sensor, such as a Hall-effect sensor, or as complicated as a highly sophisticated engine management computer responding in real time to a number of factors to include actual conditions inside of the combustion chamber 17 as they happen in real time as is known in the art. When enabled by the engine timing signal source 65 , the signal line driver circuit 127 then “cleans up” and strengthens the set of six overlapped sequential signals 115 , 117 , 119 , 121 , 123 and 125 without otherwise changing them before they are sent out through a set of six control signal output lines 129 , 131 , 133 , 135 , 137 and 139 to each of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 .
FIG. 11 is an electrical schematic for each high voltage discharge circuit 51 , 53 , 55 , 57 , 59 and 61 . Each of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 is connected to a 24 volt power source 143 and to one of the six control signal output lines 129 , 131 , 133 , 135 , 137 and 139 . When a signal is received by its intended high voltage discharge circuit 51 , 53 , 55 , 57 , 59 and 61 it turns on a power MOSFET 145 labeled Q-1. In one embodiment of the present invention, the power MOSFET (Metal Oxide Surface Effect Transistor) 145 labeled Q-1 is a MTY55N20E made by Motorola and it is rated for 55 amps at 200 volts.
When the power MOSFET 145 labeled Q-1 is turned on, a high voltage transformer 147 labeled T-1 then has current flow from the 24 volt power source 143 through a primary winding power lead 149 . The current passes through a primary winding 151 of the high voltage transformer 147 labeled T-1, through a primary winding ground lead 153 , through the power MOSFET 145 labeled Q-1, through a resistor 155 labeled R-1 that is rated at 0.2 ohms and 10 watts, and then finally to a low voltage ground connection 157 . This low voltage ground connection 157 is shared by all of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 and it is also used by all of the components of the signal generation circuit 63 . There is a large value capacitor 159 labeled C-1 which is rated at 1 microfarad and a small value capacitor 161 labeled C-2 which is rated at 0.01 microfarads. Both are attached in parallel across the primary winding power lead 149 and the primary winding ground lead 153 .
An electrically isolated secondary winding 163 of the high voltage transformer 147 labeled T-1 has an electrically isolated secondary winding ground lead 165 connected to an electrically isolated “floating” high voltage ground 167 that is shared in the same position of each circuit in all of the six high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 . The electrically isolated secondary winding 163 of the high voltage transformer 147 labeled T-1 is connected to an electrically isolated secondary winding high voltage output lead 169 . The electrically isolated secondary winding high voltage output lead 169 is in turn connected to the appropriate one of the set of six spark plug type high voltage wires 39 , 41 , 43 , 45 , 47 and 49 which in turn are connected to one of the set of six high voltage terminals 31 on the ceramic sleeve 23 .
FIG. 12 shows the overall combination of elements of the electrical system according to the present invention. This includes a 5 volt power source 171 used by all of the circuitry inside the signal generation circuit 63 . Further a low voltage ground connection 157 is shown as being shared by all of the high voltage discharge circuits 51 , 53 , 55 , 57 , 59 and 61 and with the signal generation circuit 63 .
It should be appreciated that the other ways of creating and controlling the Ring-of-Fire high voltage discharge 35 . Although any means of creating and controlling the Ring-of-Fire must place it so that the injected fuel spray pattern 37 goes next to or through it as fuel enters the combustion chamber 17 .
Referring to FIG. 13 , the present invention also includes a furnace using the Ring-of-Fire or plasma ball ignition system. The furnace in FIG. 13 is shown with a plasma ball high voltage power source 200 . The high voltage power source 200 sends out its plasma generating high voltage output through a bundle of six spark plug type high voltage wires 202 to a fuel burner circuitry housing 206 which is mounted on a fuel burner 208 . An ignition control signal wire 204 connects the high voltage power source 200 to the fuel burner control system 332 shown in FIG. 19 which is inside the fuel burner circuitry housing 206 . It is through the ignition control signal wire 204 that the on/off input for the high voltage source 200 is sent from the fuel burner control system 332 .
A burner air tube 216 connects the fuel burner 208 to a furnace 218 . A blower housing 214 brings in fresh air through an air inlet 210 and also brings in recirculated exhaust through a recirculated exhaust outlet 212 from an exhaust gas recirculation pipe 226 .
The burner air tube 216 is connected to a furnace boiler 218 which is heated by combustion from the fuel burner 208 . The combustion exhaust gases exit the furnace boiler 218 through a furnace exhaust flue 220 . The exhaust gas recirculation pipe 226 enters the furnace exhaust flue 220 through a hole 224 . The exhaust gas from the furnace exhaust flue 220 enters the exhaust gas recirculation pipe 226 through an exhaust gas recirculation inlet 222 . An exhaust gas recirculation valve 228 can control the amount of exhaust gases recirculated. Although the exhaust recirculation valve 228 shown is as a manual valve, it is also possible to use an automatically controlled valve.
Exhaust gas recirculation reduces the amount of oxides of nitrogen formed during combustion by diluting the fresh air entering through the air inlet port 210 with exhaust originally taken from the furnace exhaust flue 220 and conveyed through the exhaust gas recirculation pipe 226 to the blower housing 214 . This creates a measured dilution of the incoming fresh air charge with the exhaust and allows less fuel to be burned for a given volume of gas throughput to the burner 208 while still maintaining the proper fuel to air mixture. This has the overall effect of reducing the temperature at the tip of the combustion flame which is where the oxides of nitrogen are formed.
Once the main flow of exhaust gases pass the exhaust system junction, they then pass by an exhaust flue damper 244 before traveling the rest of the way out of the furnace exhaust flue 220 to the atmosphere.
FIG. 14 shows a nozzle and igniter assembly that resides inside the burner air tube 216 . When in operation, fuel for the nozzle and igniter assembly arrives through the burner nozzle fuel inlet 246 and then travels through a burner nozzle fuel pipe 248 to a fuel nozzle orifice 250 . There is an electrode insulator mounting bracket 252 mounted to the burner nozzle fuel pipe 248 which holds a set of six plasma generation electrode insulators 256 . Each plasma generation electrode insulators 256 has a plasma generation electrode 258 passing therethrough and the end closest to the fuel burner 208 has a plasma generation electrode terminal 254 . The other end of the electrode 258 has a tip 260 . The tips 260 are preferably evenly spaced around and in front of the fuel nozzle orifice 250 . While six electrodes each having insulators are shown, at least three electrodes are needed to achieve the results of the present invention and more than six electrodes are also possible.
FIG. 15 shows the nozzle and igniter assembly mounted inside the burner air tube 216 with the power for the plasma generation coming through the bundle of high voltage wires 202 that are attached to the plasma generation electrode terminals 254 . The other end of the bundle of the high voltage wires 202 is connected to the high voltage power source 200 . On the front end of the air tube 216 is mounted a flame retention plate 264 . The nozzle and igniter assembly has the electrode tips 260 protrude through the flame retention plate 264 .
The plasma generation electrode tips 260 are placed in front of the fuel nozzle orifice 250 . In order to prevent unintentional arcing between the plasma generation electrodes 258 and the flame retention plate 264 , a set of plasma generation tip insulators 262 are mounted on the electrode 258 so as to leave the plasma electrode tips 260 exposed to form the plasma.
FIG. 16 shows the arrangement of the plasma generation electrodes 260 and their insulators 262 with relation to the flame retention plate 264 . Also clearly shown is how the set of plasma generation tips 260 are arrayed evenly around the fuel nozzle orifice 250 . Also shown is a set of eight flame retention plate air passages 266 which are arrayed radially around the center of the flame retention plate 264 .
FIG. 17 is a front end view of the nozzle and igniter assembly with the flame retention plate 264 removed for clarity in order to expose the location of a fuel burner spray nozzle 268 . The fuel burner spray nozzle 268 has the fuel nozzle orifice 250 in the center thereof with the set of six plasma generation electrode tips 260 arrayed radially there around.
When the furnace is in operation, the plasma generating high voltage output from the high voltage source 200 is sent through the bundle of high voltage wires 202 to the nozzle and igniter assembly. There each wire from the bundle of high voltage wires 202 is attached to the respective plasma generation electrode terminal 254 . This allows the plasma generating high voltage output to be conducted along the length of the electrodes 258 to the plasma generation electrode tips 260 .
At the tips 260 , the plasma generating high voltage output from the high voltage source 200 discharges and thereby forms a plasma ball that all of the fuel spraying out from the fuel nozzle orifice 250 must pass through.
The plasma ball is believed to be the main location where the fuel treatment and ignition occur. As best understood, the effect of the plasma ball on the fuel spray that passes therethrough is to remove at least some of the outer valence electrons holding the fuel molecule together. This causes the fuel molecule to break apart into shorter chain hydrocarbons that have also been ionized as a result of passing through the plasma. These ionized shorter chain hydrocarbons not only burn cleaner and more efficiently when compared to longer chain hydrocarbons, the ionized shorter chain hydrocarbons also ignite rapidly upon contact with oxygen due to their ionization state.
FIG. 18 shows the schematic diagram of a single high voltage discharge circuit out of the at least three high voltage discharge circuits within the high voltage power source 200 . The number of high voltage discharge circuits is equal to the number of electrodes used in the device. This circuit is controlled through a control signal input line 270 that is connected to the gates of a set of three matching power Metal Oxide Surface Field Effect Transistors (henceforth referred to as MOSFETs) 272 . These three MOSFETs 272 are the switches that when turned on allow current to flow from a 24-volt power source 283 through a primary winding 276 of a high voltage transformer labeled T1 277 . The three MOSFETs 272 connect the other end of the primary winding 276 to a low voltage ground connection 284 through a 0.2 ohm resistor 285 . Between the low voltage side of the primary winding 276 and low voltage ground 284 are a capacitor of 4700 picofarads 286 , another capacitor of 4700 picofarads 288 and a capacitor of 2200 picofarads 290 and a high amperage diode 282 . When used in this circuit, the high amperage diode 282 acts as a free wheeling diode.
Connected across the leads to the primary winding 276 are a capacitor of 0.047 microfarads 292 , a capacitor of 0.1 microfarads 294 and a capacitor of 2200 picofarads 296 . Also attached to the power side of the primary winding 276 connected to the low voltage ground 284 are a capacitor of 4700 picofarads 298 , a capacitor of 2200 picofarads 300 , a capacitor of 0.1 microfarads 302 and a capacitor of 1.0 microfarad 304 .
Connected to a secondary winding 278 of the high voltage transformer labeled T1 277 is a spark plug type high voltage wire 280 that eventually goes to the plasma generation electrode terminal 254 of one of the plasma generation electrodes 258 . The other lead from the secondary winding 278 of the high voltage transformer labeled T1 277 is an electrically isolated secondary winding ground lead 279 connected to an electrically isolated “floating” high voltage ground 281 .
When the power MOSFETs 272 are turned on by an input from a signal generation circuit 330 (shown in FIG. 19 ) through the control signal input line 270 more than just the electricity from the 24 volt power source 283 flows through the primary winding 276 of the high voltage transformer labeled T-1 277 . Four capacitors 298 , 300 , 302 , and 304 of different values also discharge through the primary winding 276 of the high voltage transformer 277 .
These four capacitors 298 , 300 , 302 , and 304 also set up a resonant tank circuit with the primary winding 276 which acts as the inductor in the tank circuit. Since each of the four capacitors 298 , 300 , 302 , and 304 have a different value, four resonant tank circuits are set up, each one resonating at a different frequency. When the power MOSFETs 272 are turned on, the diode 282 plays an important role in this resonance in that the diode 282 and the power MOSFETs 272 allow current to flow in both directions during resonance through the primary winding 276 . When the power MOSFETs 272 are turned off, resonance can occur for another half cycle through the diode 282 .
This does not however stop circuit resonance because at this point the three capacitors 292 , 294 , 296 (each of a different value) that are across the leads to the primary winding 276 take over and continue to resonate in the resonant tank circuit they form. Since these three capacitors 292 , 294 , and 296 all have different values, three different tank circuits are formed that continue to resonate at three different frequencies even after the power MOSFETs 272 are turned off.
Also contributing to the collection of various resonant frequencies are the three capacitors 286 , 288 , and 290 that are connected between the lead of the primary winding 276 opposite its lead connected to the 24 volt power source 283 and the low voltage ground 284 . Although the values of two of the capacitors 286 and 288 are the same, it was determined empirically that this combination produced the most vigorous plasma discharge.
FIG. 19 shows how a set of six high voltage discharge circuits 318 , 320 , 322 , 324 , 326 , and 328 of the type shown in FIG. 18 are put together inside the high voltage power source 200 . Not only do the individual high voltage power discharge circuits 318 , 320 , 322 , 324 , 326 , and 328 produce a wide variety of resonance frequencies, these circuits also interact with each other through the electrically isolated “floating” high voltage ground 281 . As a result, all six of the plasma generation electrodes 258 are contributing to the ball of plasma at all times. It is believed that this is a reason why the plasma ball is formed between the set of six electrode tips 260 instead of what would appear to be a circular arc with a hole in it that would allow fuel to pass through without being ionized.
When the fuel burner control circuit 232 inside the fuel circuitry housing 206 turns on the fuel burner 208 , the fuel burner control circuit 232 also sends an enable signal through the ignition control signal wire 204 to the signal generation circuit 330 . The other aspects of the circuit in FIG. 19 are similar to the circuit block diagram shown in FIG. 12 . The main difference is that the six high voltage outputs go through the high voltage wires 306 , 308 , 310 , 312 and 314 which are grouped together into a bundle of high voltage wires 202 . The wires 202 connect with the nozzle and igniter assembly in the oil burner 208 instead of being connected to an injector-igniter assembly 23 in an internal combustion engine as described in FIG. 12 .
The other major difference is that plasma generation for use in the fuel burner 208 is continuous for as long as it is in operation to provide a flame to the furnace boiler 218 . It is because of this continuous plasma generation that the approach of having three MOSFETs 272 in parallel with each other was adopted in order to reduce heat buildup therein. In order to handle the greater fuel flow rate found in larger furnaces and similar installations it was necessary to develop the improved high voltage discharge circuit design in order to produce a larger and more intense plasma.
It is to be understood that although the present invention has been described with regards to preferred embodiments thereof, various other embodiments and variants may occur to those skilled in the art, which are within the scope and spirit of the invention, and such other embodiments and variants are intended to be covered by the following claims. | An apparatus and method for the creation, placement and control of an area of electrical ionization within an internal combustion engine combustion chamber or a fuel burner for a furnace is disclosed. A furnace includes a fuel source, a fuel burner, a plasma nozzle and igniter assembly, and the associated housing and flue structures. The plasma nozzle and igniter assembly is arranged so that the fuel sprayed out from the nozzle into the combustion area passes through or in close proximity to the area of plasma ionization. A fuel burner equipped with this electrical ionization device has its fuel efficiency enhanced by the complete and immediate combustion of substantially all of the fuel that passes through the area of plasma ionization. Exhaust gas recirculation using this system is also disclosed. | 5 |
This application is a continuation application of the U.S. patent application Ser. No. 12/090,352, filed May. 08, 2008, now U.S. Pat. No. 7,854,574, which claims priority to International Patent Application No. PCT/GB2006/050256, filed Aug. 23, 2006, which claims priority to United Kingdom patent Application Nos. 0523927.2, filed Nov. 24, 2005 and 0606408.3, filed Mar. 30, 2006. The entirety of all of the aforementioned applications is incorporated herein by reference.
FIELD
The present invention relates to a gabion, particularly to a gabion, and especially to a multi-compartmental gabion, which can be used without a lining material.
BACKGROUND
Gabions are temporary or semi-permanent fortification structures which are used to protect military or civilian installations from weapons assault or from elemental forces, such as flood waters, lava flows, avalanches, slope erosion, soil instability and the like. WO-A-90/12160 discloses wire mesh cage structures useful as gabions. The cage structure is made up of pivotally interconnected open mesh work frames which are connected together under factory conditions so that the cage can fold concertina-wise to take a flattened form for transportation to site, where it can be erected to take an open multi-compartmental form for filling with a suitable fill material, such as sand, soil, earth or rocks.
WO-A-00/40810 also concerns a multi-compartmental gabion which folds concertina-wise for transportation, and which comprises side walls extending along the length of the multi-compartmental gabion, the side walls being connected at spaced intervals along the length of the gabion by partition walls which are formed from two releasably connected sections, which after use of the gabion can be released, and the gabion unzipped for recovery purposes.
Existing gabions have certain disadvantages with respect to construction and longevity. For example, such gabions frequently comprise a wire mesh cage structure lined with a geotextile material, the lining adding to the cost and complexity of the gabion structure, and constituting a significant limitation on the functionality of the gabion after deployment over a long period of time. Particularly in harsh environmental conditions (intense sunlight, wind, rain, snow, sand or salt spray, or a combination of any two or more of these), the geotextile material tends to degrade and this can weaken the functionality of the gabion by, for example, the occurrence of rips, tears or holes in the liner, through which the gabion fill material can fall.
BRIEF DESCRIPTION OF THE FIGURES
The invention will now be more particularly described with reference to the following drawings, in which:
FIGS. 1A-1C show a perspective view of a multi-compartmental gabion in accordance with the invention;
FIG. 2 shows the multi-compartmental gabion of FIGS. 1A-1C filled with a gabion fill material;
FIG. 3 shows a perspective view of a multi-compartmental gabion in accordance with a second embodiment of the invention;
FIG. 4 shows in close-up perspective view the pivotal connection between neighbouring side wall element panels of the gabion of FIGS. 1A-1C , 2 or 3 ;
FIG. 5 shows in close-up perspective view the optional openable pivotal connection between neighbouring side wall element panels of the multi-compartmental gabion of FIGS. 1A-1C , 2 or 3 , before the releasable locking member is installed;
FIG. 6 shows in close-up perspective view the openable pivotal connections were made between the components of the FIG. 5 drawing.
FIG. 7 shows a close-up of a hinged connection of a gabion according to the invention;
FIG. 8 shows a close-up of a hinged connection of a gabion according to the invention under load;
FIG. 9 shows a close-up of a hinged connection of a gabion according to the invention being broken;
FIGS. 10 to 15 show different partial cross-sections through edges of the walls;
FIGS. 16 to 19 show different partial cross-sections through edges of the walls; and
FIG. 20 shows a side view of a wall of the gabion.
DETAILED DESCRIPTION
Accordingly, there is a need for an improved gabion. There is also a need for an improved multi-compartmental gabion.
According to the present invention there is provided a gabion comprising side walls connected together at spaced intervals by partition walls, the side walls comprising at least one substantially closed side wall element panel, wherein the or each substantially closed side wall element is manufactured of a relatively rigid sheet material.
According to the present invention there is provided a multi-compartmental gabion comprising opposed side walls connected together at spaced intervals along the length of the gabion by a plurality of partition walls, the side walls comprising a plurality of side wall element panels, at least one side wall element panel comprising a substantially closed panel, wherein the or each substantially closed side wall element is manufactured of a relatively rigid sheet material.
The substantially closed panel acts in use of the gabion to prevent a gabion fill material (sand, earth, soil, stones or fines, for example) from falling through the side wall without the aid of a gabion lining material.
Preferably, the rigidity of the material is sufficient to prevent excessive bulging of the side wall element panel when the gabion is filled with a fill material.
Other desirable characteristics of the sheet material include, either alone or in combination:
Durability Toughness Tear resistance Scratch and erosion resistance Corrosion resistance Thermal stability Ultraviolet stability Low density Low cost Recyclability
Suitable materials include steel, aluminium, titanium, other metals, alloys, plastics or certain natural materials, or combinations of two or more thereof. Where a metal is used, it is preferably either treated for corrosion resistance, e.g. by galvanisation and/or painting or is inherently corrosion resistant, e.g. a stainless steel.
Where the sheet material is a plastics material it may be polyethylene (PE), polypropylene (PP) or a composite such as glass fibre reinforced polymer (GFRP). The molecular weight of the chosen plastic can be selected to suit the application (e.g. LDPE, HDPE, LDPP, HDPP). Where plastics are used, they are preferably ultraviolet stabilised e.g. by the addition of fillers to prevent them becoming discoloured and/or brittle upon extended exposure to sunlight.
In certain circumstances, it may be desirable to add coloured fillers to the plastics material to provide a desired aesthetic effect. In one aspect of the invention, more than one colour filler is added to the plastics material and partially blended therewith to create a non-homogeneous coloured/marbled effect. For example; green and brown; white and grey; or yellow and brown colour fillers could be added to provide camouflage for vegetated, snowy or dessert environments, respectively. Because such colours are integral with the sheet material (i.e. not a surface decoration), they are less susceptible to removal by erosion (e.g. by sand in a sandstorm).
It is desirable to make the sheet material as thin as possible to reduce the folded volume of the gabion when being stored or transported. A major advantage of using thin-sheet materials is weight saving, which reduces transportation costs and facilitates manual deployment/rearrangement of the gabion.
The substantially closed panel is preferably provided with means for receiving a hinge member for the purpose of connecting the substantially closed panel pivotally to a neighbouring side wall element panel. The hinge receiving means are preferably provided on a region of the closed panel of greater thickness than an adjacent region of the panel. This helps to prevent tearing of the panel by the hinge member in use of the gabion when the side walls of the gabion act to restrain the gabion fill material. The region of the closed panel of relatively greater thickness is preferably provided at or in the region of an interconnection edge of the closed panel. Preferably, the region of relatively greater thickness is an elongate panel region alongside or at the interconnection edge.
In one example, illustrated by FIG. 7 , the hinged connections 10 comprise helical springs 112 threaded through apertures 114 disposed towards the edges off each wall 116 , 118 , which are manufactured of sheet material. In FIG. 8 , it can be seen that when a force F is applied to the hinged connection 110 , the apertures 114 tend to deform. Upon application to sufficient force, as illustrated in FIG. 9 , the apertures 114 tear-through, thereby disconnecting the hinged connection. One solution is to provide thicker sheet material. Where mesh-type walls are used, this is not necessarily a problem because the wires of the mesh can be thicker for a given overall gabion weight. However, to use sheet metal of the same thickness as the wire diameter could give rise to a prohibitively heavy gabion.
It is therefore desirable, additionally or alternatively to the aforementioned variants, to reinforce the sheet material walls in regions of increased stress.
The elongate panel section of relatively greater thickness may be provided by a folded over edge section of the substantially closed panel. In order to facilitate the folding over of the panel under factory conditions, the corners of the panel at either or both ends of the edge being folded may be removed prior to folding.
If further reinforcement is required, the edge of the sheet material can be folded a number of times or rolled-up.
Additionally or alternatively, additional reinforcing members may be affixed at or near to the edges of the sheet material. Preferably, such reinforcing members are strips that can be welded, glued or otherwise fastened in-situ.
Apertures in the sheet material may pass through one or more layers.
Where the sheet material is provided with reinforcement, the reinforcement may be faired to minimize/prevent snagging with other objects and/or a user's hands.
Fairings may be provided by way of trimming corners, removing burrs and/or providing rounded edges.
Suitably, the substantially closed panel is provided with means for connecting the panel pivotally to a neighbouring panel in the gabion. When such means comprise one or more apertures in the panel, for receiving a hinge member for example, the gabion may be provided with means for covering the one or more apertures to prevent or hinder a gabion fill material from escaping through said one or more apertures. Suitable covering means include cover strips, cover sheets, cover tapes, cover bands, cover ribbons, cover plates, cover coatings, cover layers, cover tabs, covering adhesives and covering gels, doughs, putties and the like. Alternatively, or as well, the one or more apertures may be provided with blocking means for at least partly blocking the egress of fines and other gabion fill materials from the gabion in use thereof. Suitable blocking means include blocking strips, blocking sheets, blocking tapes, blocking bands, blocking ribbons, blocking plates, blocking coatings, blocking layers, blocking tabs, blocking adhesives and blocking gels, doughs, putties and the like.
Other forms of pivotal connection between neighbouring side wall element panels are also contemplated within the scope of the invention—for example an interconnecting edge of a first neighbouring panel may be provided with a protruding portion interconnecting with a corresponding inset portion in the corresponding interconnection edge of a second neighbouring panel. A locking member may extend through the protruding portion and be received in the second neighbouring panel interconnection edge either side of the inset portion to lock the protruding portion into the inset portion in a pivotal fashion.
Alternatively, an elongate locking member may be provided in the interconnection edge of a first neighbouring side wall element panel, extending slightly beyond the interconnection edge at the top and bottom of the panel, and one or more linking members may then secure the locking member to the second neighbouring side wall element panel in the region extending slightly beyond the interconnection edge. Many other forms of pivotal connection may also be suitable in the realisation of the invention.
The gabion of the invention may be provided with a plurality of side wall element panels, each comprising a substantially closed panel having releasable interconnections which when released allow the side wall element panels to open with respect to the gabion to allow access from the side of the gabion to any contents of the gabion compartments.
According to the present invention there is provided a multi-compartmental gabion as hereinbefore described comprising opposed side walls connected together at spaced intervals along the length of the gabion by a plurality of partition walls, the spaces between neighbouring pairs of partition walls defining, together with the side walls, individual compartments of the multi-compartmental gabion, individual compartments of the multi-compartmental gabion being bounded by opposed side wall sections of the respective opposed side walls, the partition walls being pivotally connected to the side walls, and the side wall sections of the individual compartments comprising at least one substantially closed side wall element panel, pivotal connections being provided between neighbouring side wall element panels allowing the multi-compartmental gabion to fold concertina-wise for storage or transport.
At least one side wall element panel may be formed from a closed panel having an interconnection edge adjacent a neighbouring side wall element panel, an elongate panel being provided at or in the region of the interconnection edge, the thickness of the elongate panel being greater than the side wall element panel in the region thereof adjacent the elongate panel, the elongate panel section being provided with means for receiving a hinge member for pivotally connecting the side wall element panel to a neighbouring side wall element panel.
The partition walls may likewise be formed from closed panels. However, the partition walls may also be formed from an open mesh material, for example.
One multi-compartmental gabion of the invention therefore facilitates post-deployment recovery of the gabion by providing at least one openable side wall section along the length of the gabion. Preferably, a plurality of openable side wall sections are provided. More preferably all of the side wall sections, except those at the ends of the gabion in a gabion having more than two compartments, are openable. Most preferably, all of the side wall sections along the length of the gabion are openable. By “openable” is meant that the pivotal connection between the connected side wall element panels of the side wall section is provided by a hinge member provided on one or both of the connected side wall element panels and by a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection therebetween. In some preferred embodiments of the invention, a first hinge member is provided on a first neighbouring side wall element panel and a second hinge member is provided on a second neighbouring side wall element panel, the releasable locking member cooperating with both the first hinge member and the second hinge member releasably to secure the pivotal connection. Opening of an openable side wall section is achievable by releasing the locking member and pulling apart the resulting unconnected side wall element panels.
Each side wall section may comprise a single side wall element panel, in which case the openable pivotal connection between neighbouring side wall element panels is located between neighbouring side wall sections. In this case the pivotal connection between neighbouring side wall element panels and the partition wall marking the boundary between corresponding neighbouring side wall sections is also openable to allow the first neighbouring side wall element panel to be released both from the second neighbouring side wall element panel and from the partition wall. Alternatively, each side wall section may comprise a plurality of side wall element panels, in which case the openable pivotal connection may be provided between neighbouring side wall element panels of a given side wall section. However, even when side wall sections comprise a plurality of side wall element panels, openable pivotal connections may be provided between neighbouring side wall sections as well as or instead of between neighbouring side wall element panels of a given side wall section. Multi-compartmental gabions comprising a plurality of side wall sections, with different numbers of side wall element panels constituting different side wall sections are also contemplated.
Deployment of the gabion of the invention will generally be effected by transporting the folded gabion to a deployment site, unfolding the gabion and filling each individual compartment of the gabion with a fill material. Generally the fill material will be dictated at least partly by the availability of suitable materials at the deployment site. Suitable, fill materials include, but are not limited to, sand, earth, soil, stones, rocks, rubble, concrete, debris, snow, ice and combinations of two or more thereof.
There are a number of reasons why it could be desirable to open side wall sections of the gabion. For example, when the deployed gabion is to be decommissioned, it is often desirable to recover the gabion for environmental or aesthetic reasons, or simply out of consideration for the local population. Recovery of the gabion of the invention is facilitated by opening up all of the openable side wall sections of the gabion, at least partly removing the fill material from the compartments, and removing the gabion from site.
By way of further example, if the deployed gabion is damaged in use it may be desirable to replace or repair the damaged section of the gabion. Access via the openable side walls of the damaged section facilitates this. Similarly, when it is desired for reasons unconnected with damage to move, alter or replace a gabion section (for example if the position or orientation of the gabion requires alteration), such replacement is again facilitated by the capacity to remove at will fill material from selected gabion sections.
Although certain embodiments of the invention are characterised by the presence of at least one openable side wall section, and preferably by a plurality of openable side wall sections, it will often be desirable to provide each individual compartment of the gabion, optionally with the exception of the end compartments of the gabion (when the gabion has more than two compartments), with openable side wall sections. Accordingly there is provided in accordance with the invention a multi-compartmental gabion as described wherein the pivotal connection between the connected side wall element panels of each of the side wall sections, or between each neighbouring side wall section, optionally with the exception of the end side wall sections, is provided by a hinge member provided between the first side wall element panel of a given side wall section and a second neighbouring side wall element panel of the given or a neighbouring side wall section, and a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection. Preferably, a first hinge member is provided on the first side wall element panel and a second hinge member is provided on the second neighbouring side wall element panel, and the releasable locking member cooperates with both first and second hinge members releasably to secure the pivotal connection.
Furthermore, although a multi-compartmental gabion will be in accordance with the certain aspects of the invention if a plurality of openable side wall sections are provided on one side wall, it is also contemplated that openable side wall sections may be provided on both side wall sections of an individual compartment to allow access to the fill material from both sides. Accordingly the invention provides a multi-compartmental gabion as described wherein the pivotal connection between the connected side wall element panels of at least a plurality of opposed side wall sections is provided by a hinge member provided between a first side wall element panel of a given side wall section and a second neighbouring side wall element panel of the given or a neighbouring side wall section, and by a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection. Also contemplated within the scope of the invention is a multi-compartmental gabion as described wherein the pivotal connection between the connected side wall element panels of at least a plurality of opposed side wall sections is provided by a first hinge member provided on a first side wall element panel of a given side wall section and by a second hinge member on a second side wall element panel of the given or a neighbouring side wall section and by a releasable locking member connecting the first hinge member to the second hinge member.
Also contemplated is that openable side wall sections may be provided alternately on first and second opposed side walls along at least part of the length of the gabion. In this way when a gabion is being recovered, cooperating excavating equipment or personnel can be deployed on opposite sides of the gabion to remove fill material from neighbouring compartments simultaneously or in rapid succession if simultaneous excavation is undesirable for safety or other reasons. Thus, the invention provides a multi-compartmental gabion as described wherein the pivotal connection between the connected side wall element panels of at least a plurality of side wall sections staggered on alternating opposite side walls along at least part of the length of the gabion is provided by a hinge member provided between a first side wall element panel of a given side wall section and a second neighbouring side wall element panel of the given or a neighbouring side wall section, and by a releasable locking member cooperating with the hinge member releasably to secure the pivotal connection. Also contemplated within the scope of the invention is a multi-compartmental gabion as described wherein the pivotal connection between the connected side wall element panels of at least a plurality of side wall sections staggered on alternating opposite side walls along at least part of the length of the gabion is provided by a first hinge member provided on a first side wall element panel of a given side wall section and by a second hinge member on a second side wall element panel of the given side wall section and by a releasable locking member connecting the first hinge member to the second hinge member.
A side wall section preferably comprises a single side wall element panel, or two side wall element panels. However, a side wall section, a plurality of side wall sections, or each side wall section may, if desired comprise more than two side wall element panels. In this case pivotal connections are preferably provided between each side wall element panel.
Accordingly the invention provides a multi-compartmental gabion as described wherein one or more side wall sections comprise a single side wall element panel. The invention also provides a multi-compartmental gabion as described wherein one or more side wall sections comprise two side wall element panels pivotally connected together (preferably openably pivotally connected together). Also contemplated within the scope of the invention is a multi-compartmental gabion as described wherein one or more side wall sections comprise more than two side wall element panels, with pivotal interconnections being provided between each neighbouring pair of side wall element panels.
One multi-compartmental gabion of the invention comprises a plurality of connected compartments, each compartment being bounded at opposed ends by a pair of opposed partition walls, and being bounded at opposed sides by a pair of opposed side wall sections, each side wall section comprising at one side wall element panel. In at least one, two, three or more individual compartments of the multi-compartmental gabion, at least one such side wall element panel is arranged to be openable, the mechanism of opening being operable when the compartment is loaded with a fill material.
The concertina-wise folding of the gabion may be effected by the side wall sections folding in towards the central longitudinal axis of the gabion, or by the side wall sections folding out away from the central longitudinal central axis of the gabion. The former manner will generally be preferable as the resulting folded gabion will have a relatively smaller cross-sectional surface area in a plane orthogonal to the central longitudinal axis of the gabion.
In one preferred embodiment of the invention the pivotal interconnection between connected walls and/or wall sections and/or wall elements is achieved by providing interconnected walls, wall sections and/or wall elements with a row of apertures along or in the region of an interconnection edge thereof and by providing a coil member helically threaded through a plurality of apertures along the interconnection edge. In the case of a straightforward (i.e.—non-openable) pivotal connection, a single coil member may be helically threaded through the connection edge apertures of two (or more) neighbouring walls, wall sections and/or wall elements to achieve pivotal interconnection therebetween. Accordingly, there is provided in accordance with the invention a multi-compartmental gabion as described wherein at least one pivotal connection is provided by the presence of a coil member helically threaded through connection edge apertures of connected walls, wall sections or wall elements.
In another preferred embodiment of the invention the openable pivotal interconnection between connected side wall element panels is achieved by providing the interconnected side wall element panels with a row of apertures along or in the region of an interconnection edge thereof and by providing a first coil member helically threaded through a plurality of apertures along the interconnection edge of a first side wall element panel, a second coil member helically threaded through a plurality of apertures along the interconnection edge of a second side wall element panel (connected to the first side wall element panel along the interconnection edge) and a releasable locking member threaded through overlapped first and second coil members. Thus, in the case of an openable pivotal connection, a pair of coil members may be helically threaded through the respective opposed connection edge apertures of two neighbouring side wall element panels, and a releasable locking member inserted through the overlapped coils of the opposed pair of coil members. Accordingly, there is provided in accordance with the invention a multi-compartmental gabion as described wherein at least one openable pivotal connection between neighbouring side wall element panels is provided by the presence of a pair of coil members helically threaded through respective connection edge apertures of neighbouring side wall element panels and by a releasable locking member threaded through the respective coil members when overlapped.
Thus, there is provided in accordance with the invention a multi-compartmental gabion as described wherein the or at least one hinge member comprises a helical coil.
The releasable locking member may be of any suitable shape or size and may for example comprise an elongate locking pin. The pin may be provided with a gripping protrusion at one end to facilitate manual insertion and/or removal of the locking pin. The gripping protrusion may for example comprise a loop at one end of the locking pin. Accordingly there is provided in accordance with the invention a multi-compartmental gabion as described wherein at least one locking member comprises an elongate locking pin.
The side walls, side wall sections, side wall element panels and/or partition walls preferably comprise one or more panel sections of any suitable material, for example steel, aluminium, titanium, any other suitable metal or alloy, or from a plastics, ceramic or natural material such as timber, sisal, jute, coir or seagrass. Normally, steel is preferred, in which case the steel is preferably treated to prevent or hinder steel erosion during deployment of the gabion. The panel is a substantially closed panel which acts in use of the gabion to contain a gabion fill material without the need for a gabion compartment lining material, such as a geotextile liner. However, the gabion of the invention may be used together with a suitable lining material if necessary. In the case of a closed panel, connection edge apertures where needed will normally be machined or otherwise provided in or in the region of the panel edge.
The gabion of the invention may comprise pivotally interconnected, substantially closed, side wall element panels which are connected together under factory conditions so that the gabion can take a flattened form for transportation to site where it can be erected to take a form in which panels thereof define side, partition and end walls and an open top through which the compartments of the gabion may be filled. Preferably, under factory conditions said panels define side, partition and end walls and are pivotally interconnected edge to edge and are relatively foldable to lie face to face in the flattened form for transportation to site and can be relatively unfolded to bring the gabion to the erected condition without the requirement for any further connection of the side, partition or end walls on site.
In preferred embodiments of the invention, the side walls of the gabion each comprise a plurality of side panels pivotally connected edge to edge and folded concertina fashion one relative to another. The side walls are preferably connected by partition walls which are pivotally connected thereto, the gabion structure being adapted to be erected on site by pulling it apart by the end walls so that when it is moved from the flattened form to the erected condition the side walls unfold and define with the end walls and partition walls an elongated wall structure having a row of cavities to be filled with a fill material and of which each partition wall is common to the pair of cavities adjacent the partition wall.
Referring in more detail to FIGS. 1A-1C and 2 , there is shown multi-compartmental gabion 1 comprising opposed side walls 2 , 3 connected together at spaced intervals along the length of gabion 1 by a plurality of partition walls 4 , 5 , 6 defining, together with side walls 2 , 3 individual compartments 7 , 8 , 9 of multi-compartmental gabion 1 . Individual compartment 8 (and other similar individual compartments) of multi-compartmental gabion 1 is bounded by opposed side wall sections 10 , 11 of the respective opposed side walls 2 , 3 . Partition walls 4 , 5 (and similar partition walls) are pivotally connected to side walls 2 , 3 at hinge points 11 , 11 ′, 12 , 12 ′.
In the embodiments shown in FIGS. 1A-1C and 2 , each side wall section 10 , 11 of multi-compartmental gabion 1 comprises two side wall element panels 13 , 13 ′; 14 , 14 ′, with pivotal connections being provided between neighbouring side wall element panels 13 , 13 ′, and between neighbouring side wall element panels 14 , 14 ′.
The pivotal connections between partition walls 4 , 5 (and other partition walls in the multi-compartmental gabion) and side walls 2 , 3 , and the pivotal connections between neighbouring side wall element panels 13 , 13 ′; 14 , 14 ′, allow multi-compartmental gabion 1 to fold concertina-wise for flat-packing in transportation and storage In the embodiments shown in FIGS. 1A-1C and 2 , the concertina-wise folding preferably operates so that the pivotal connections between neighbouring side wall element panels 13 , 13 ′; 14 , 14 ′, move inwardly with respect to the longitudinal axis of multi-compartmental gabion 1 so that the width of the flat-packed gabion is at least approximately corresponding to the width of partition walls 4 , 5 , 6 .
The side wall element panels may be provided with texture, ribbing or other irregularities in order to maintain effective strength of the panel whilst minimising its weight, and/or to provide decorative effect.
Referring to FIG. 2 , multi-compartmental gabion 1 is shown filled with a gabion fill material 21 . Fill material 21 may be selected from any suitable available material, as hereinbefore described. Rough earth and stones are shown as the fill material in FIG. 2 . FIG. 2 also shows a cover strip 22 , 22 ′ over the hinged interconnection edges of the gabion.
Referring now to FIG. 3 , there is shown a second embodiment of the multi-compartmental gabion, in which each individual compartment comprises a pair of partition walls 34 , 35 , and a pair of opposed side wall element panels 312 , 313 . Pivotal connections therebetween allow the gabion to fold concertina-wise (first one way, and then the other) for flat packing and storage.
Referring now to FIG. 4 , there is shown a close-up perspective view of the pivotal connection between neighbouring side wall element panels 13 and 13 ′ This pivotal connection may be between two side wall element panels only, or may also include a partition wall. For convenience in the drawing, partition wall 5 has been omitted from the close-up perspective view. However, it will be understood that partition wall 5 may share this particular pivotal connection in a similar fashion. Referring to FIG. 4 , side wall element 13 comprises a substantially closed panel 41 comprising a folded over edge region 42 in which is machined a row of interconnection edge apertures 43 . Prior to folding of folded over edge portion 42 , the corners of side wall element panel 41 at either end of the interconnection edge are removed to facilitate folding. Pivotal connection therebetween is effected by a helical coil 45 which is helically threaded through the interconnection edge apertures of the neighbouring panels. Although not shown in FIG. 4 , loose end 45 of helical coil 44 may be bent round or otherwise prevented from accidentally disengaging with the top most aperture of side wall element 13 , and weakening the pivotal connection by such disengagement.
Referring now to FIG. 5 , there is shown in close-up perspective view the optional openable pivotal connection between neighbouring side wall elements 13 , 13 . In this case, both neighbouring closed panels are provided with helical coil members threaded helically through the interconnection edge apertures thereof. The first hinge member 51 and the second hinge member 52 are thereby provided. Releasable locking member 53 is shown in FIG. 6 connecting the overlapped helical coils.
Referring now to FIGS. 10 to 15 , cross-sections through the gabion are shown where the walls 126 are manufactured of sheet metal. As can be seen, a helical spring 112 is threaded through apertures 114 in the side wall 126 .
In FIG. 10 , a single fold 130 is provided to reinforce the edge of the wall 126 . The aperture 114 passes through both thicknesses 132 of the fold 130 .
In FIG. 11 , a double fold 134 is provided and the aperture 114 passes through all three thicknesses 136 of the fold 134 .
In FIG. 12 , a single fold 130 is provided, but the aperture 114 only passes through a single thickness 132 .
In FIG. 13 , a double fold 134 is provided, but the aperture 114 only passes through a single thickness 136 .
In FIGS. 14 and 15 , a reinforcing strip 138 is stuck to the wall 126 using a layer of adhesive 140 . The aperture can either pass through the reinforcing strip 138 , or the wall 126 , respectively.
In FIGS. 16 , 17 and 18 , the aperture only passes through the wall 126 . Strength/reinforcement advantages can nonetheless be attained so long as the spring 112 is pulled in the direction indicated by arrow A. This arrangement has the further advantage that the aperture 114 need only be drilled or punched through one thickness of material, which reduces manufacturing costs and/or complexity.
FIGS. 16 to 19 show partial cross-sections of the gabion where the wall 126 is manufactured of a plastics material. As can be seen, a thicker, reinforced region 142 is relatively easily formed using a suitable moulding technique. In FIGS. 17 to 19 , a reinforcing wire 144 has been co-moulded with the wall 126 to further reinforce the edge thereof.
A further possible variant of the invention sees reinforcing wires or a reinforcing mesh 146 being integrally mounded with the wall 126 as illustrated in FIG. 17 . This feature means that much thinner wall thicknesses can be provided for a given strength requirement.
Finally, FIG. 20 shows a side view of a wall panel 126 having an edge reinforcement as illustrated in FIG. 6 . As can be seen, the corners of the fold 130 have been cut away 150 to prevent sharpe edges 151 (indicated by a dotted line) protruding above the edge 152 of the wall 126 .
As can also be seen in FIG. 16 , the top and bottom edges 153 of the wall 126 have also been folded over to facilitate manual handling of the gabion and to prevent damage to neighbouring objects (not shown) such as a floor surface. | The invention provides a gabion which may be used to protect military or civilian installations from weapons assault or from elemental forces, such as flood waters, lava flows, avalanches, soil instability, slope erosion and the like, the gabion comprising side walls connected together at spaced intervals by partition walls, the side walls comprising at least one substantially closed side wall element panel, which acts in use of the gabion to prevent a gabion fill material from falling through the side wall, the said action of the substantially closed side wall element panel being effective without the aid of a gabion lining material. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. provisional application Nos. 61/417,093 and 61/417,084, both filed Nov. 24, 2010. The disclosures of the application Nos. 61/417,093 and 61/417,084 are herein incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] This invention relates generally to non-precious metal based complexes, more specifically to manganese, iron, cobalt, or nickel-containing 2,8-bis(imino)quinoline complexes and their use as efficient and selective hydrosilylation catalysts. The invention also relates to non-precious metal based 2,8-bis(imino)quinoline complexes, which themselves are not catalysts, but can be activated in-situ for the hydrosilylation reactions.
BACKGROUND OF THE INVENTION
[0003] Hydrosilylation chemistry, typically involving a reaction between a silyl hydride and an unsaturated organic group, is the basis for synthesis routes to produce commercial silicone-based products like silicone surfactants, silicone fluids and silanes as well as many addition cured products like sealants, adhesives, and silicone-based coating products. Conventionally, hydrosilylation reactions have been typically catalyzed by precious metal catalysts, such as platinum or rhodium metal complexes.
[0004] Various precious metal complex catalysts are known in the art. For example, U.S. Pat. No. 3,775,452 discloses a platinum complex containing unsaturated siloxanes as ligands. This type of catalyst is known as Karstedt's-catalyst. Other exemplary platinum-based hydrosilylation catalysts that have been described in the literature include Ashby's catalyst as disclosed in U.S. Pat. No. 3,159,601, Lamoreaux's catalyst as disclosed in U.S. Pat. No. 3,220,972, and Speier's catalyst as disclosed in Speier, J. L, Webster J. A. and Barnes G. H., J. Am. Chem. Soc. 79, 974 (1957).
[0005] Although these precious metal complex catalysts are widely accepted as catalysts for hydrosilylation reactions, they have several distinct disadvantages. One disadvantage is that the precious metal complex catalysts are inefficient in catalyzing certain reactions. For example, in the case of hydrosilylations of allyl polyethers with silicone hydrides using precious metal complex catalysts, use of an excess amount of allyl polyether, relative to the amount of silicone hydride, is needed to compensate for the lack of efficiency of the catalyst in order to ensure complete conversion of the silicone hydride to a useful product. Moreover, when the hydrosilylation reaction is completed, this excess allyl polyether must either be: (A) removed by an additional step, which is not cost-effective, or (B) left in the product which results in reduced performance of this product in end-use applications. Additionally, the use of an excess amount of allyl polyether typically results in a significant amount of undesired side products such as olefin isomers, which in turn can lead to the formation of undesirably odoriferous byproduct compounds.
[0006] Another disadvantage of the precious metal complex catalysts is that they risk not being effective in catalyzing hydrosilylation reactions involving certain type of reaction mixtures. Illustratively, it is known that precious metal complex catalysts are susceptible to catalyst poisons such as phosphorous and amine compounds. Accordingly, for a hydrosilylation involving unsaturated amine compounds, the precious metal catalysts are typically less effective than may be desired in promoting a direct reaction between these unsaturated amine compounds with Si-hydride substrates, and will often lead to the formation of mixtures of undesired isomers.
[0007] Further, due to the high price of precious metals, the precious metal-containing catalysts can constitute a significant proportion of the total cost of making silicone formulations. Recently, global demand for precious metals, including platinum, has increased, driving prices for platinum to record highs, creating a need for effective, low cost replacement catalysts.
[0008] As an alternative to precious metals, certain iron complexes have been disclosed as suitable for use as hydrosilylation catalysts. Illustratively, technical journal articles have disclosed that Fe(CO) 5 catalyzes hydrosilylation reactions at high temperatures. (Nesmeyanov, A. N. et al., Tetrahedron 1962, 17, 61), (Corey, J. Y et al., J. Chem. Rev. 1999, 99, 175), (C. Randolph, M. S. Wrighton, J. Am. Chem. Soc. 108 (1986) 3366). However, unwanted by-products such as the unsaturated silyl olefins, which are resulted from dehydrogenative silylation, were formed as well.
[0009] A five-coordinate Fe(II) complex containing a pyridine di-imine (PDI) ligand with isopropyl substitution at the ortho positions of the aniline rings has been used to hydrosilate an unsaturated hydrocarbon (1-hexene) with primary and secondary silanes such as PhSiH 3 or Ph 2 SiH 2 (Bart et al., J. Am. Chem. Soc., 2004, 126, 13794) (Archer, A. M. et al. Organometallics 2006, 25, 4269). However, one of the limitations of these catalysts is that they are only effective with the aforementioned primary and secondary phenyl-substituted silanes reactants, and not with, for example, tertiary or alkyl-substituted silanes such as Et 3 SiH, or with alkoxy substituted silanes such as (EtO) 3 SiH.
[0010] Recently new and inexpensive Fe, Ni, Co and Mn complexes containing a terdentate nitrogen ligand have been found to selectively catalyze hydrosilylation reactions, as described in co-pending U.S. Patent Application Publication Nos. 20110009573 and 20110009565, the contents of both publications are incorporated herein by reference in their entireties. In addition to their low cost and high selectivity, the advantage of these catalysts is that they can catalyze hydrosilylation reactions at room temperature while precious metal-based catalysts typically work only at elevated temperatures.
[0011] Despite these advances, in view of the high demand for silicone-based products, there is a continuing need in the silicones manufacturing community for other non-precious metal-based catalysts that are suitable for catalyzing hydrosilylation reactions.
[0012] The preparation and characterization of several iron and cobalt 2,8-bis(imino)quinoline dichloride complexes have been described by Sun et al. in Organometallics, 2010, 29 (5), pp 1168-1173. However, the catalysts disclosed in this reference were described as suitable for use in the context of olefin polymerizations, not in the context of hydrosilylation reactions.
[0013] The present invention provides an answer to the need for additional novel non-precious metal-based catalysts that are suitable for catalyzing hydrosilylation reactions.
SUMMARY OF THE INVENTION
[0014] In one aspect, the present invention is directed to a compound of Formula (I)
[0000]
[0015] or Formula (II)
[0000]
[0016] wherein:
[0017] G is Mn, Fe, Ni, or Co;
[0018] each occurrence of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 30 and R 31 is independently hydrogen, an inert functional group, C1-C18 alkyl, C1-C18 substituted alkyl, aryl, or substituted aryl, wherein optionally each of R 1 to R 9 , R 30 and R 31 may independently contain at least one heteroatom;
[0019] optionally any two of R 3 , R 7 , R 8 , R 9 , R 30 , and R 31 vicinal to one another taken together may form a ring being a substituted or unsubstituted, saturated, or unsaturated cyclic structure;
[0020] L 1 and L 2 each is a C1-C18 alkyl, C1-C18 substituted alkyl, aryl, substituted aryl, C2-C18 alkene, C2-C18 alkyne, provided that when L 1 and L 2 are alkene or alkyne, L 1 and L 2 bond with G through an unsaturated site of alkene or alkyne or
[0021] L 1 -L 2 together is one of the following:
[0000]
[0022] wherein each occurrence of R 10 , R 11 , R 13 , R 14 , R 15 and R 16 is independently hydrogen, C1-C18 alkyl, C2-C18 alkenyl, or C2-C18 alkynyl, wherein R 10 , R 11 , R 13 , R 14 , R 15 and R 16 , other than hydrogen, optionally contain at least one heteroatom, and R 10 , R 11 , R 13 , R 14 , R 15 and R 16 , other than hydrogen, are optionally substituted;
[0023] each occurrence of R 12 is independently C1-C18 alkyl, C1-C18 substituted alkyl, C2-C18 alkenyl, C2-C18 substituted alkenyl, C2-C18 alkynyl, C2-C18 substituted alkynyl, aryl, substituted aryl, wherein R 12 optionally contains at least one heteroatom;
[0024] optionally any two of R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 taken together form a ring being a substituted or unsubstituted, saturated or unsaturated cyclic structure;
[0025] each occurrence of R 17 and R 18 is independently alkyl, substituted alkyl, aryl, or substituted aryl, wherein each of R 17 and R 18 optionally contains at least one heteroatom, and wherein R 17 and R 18 taken together optionally form a ring being a substituted or unsubstituted, saturated or unsaturated cyclic structure;
[0026] each occurrence of R 19 and R 20 is independently a covalent bond that connects Si and C, an alkyl, substituted alkyl, or a heteroatom, wherein R 19 and R 20 optionally contain at least one heteroatom;
[0027] wherein L 1 -L 2 bonds with G through unsaturated sites S 1 and S 2 ; and
[0028] X is an anion, preferably F − , Cl − , Br − , I − , CF 3 R 40 SO 3 − or R 50 COO − , wherein R 40 is a covalent bond or a C1-C6 alkyl group, and R 50 is a C1-C10 hydrocarbyl group.
[0029] with the proviso that Formula (II) does not encompass the following complexes: [2,8-bis(2,6-dimethyl-C 6 H 3 N═CCH 3 )C 9 H 5 N]iron dichloride, namely, Iron, dichloro[N,N′-[(2,8-quinolinediyl-κN)diethylidyne]bis[2,6-dimethylbenzenamine-κN]]-; [2,8-bis(2,6-dimethyl-C 6 H 3 N═CCH 3 )C 9 H 5 N]cobalt dichloride, namely Cobalt, dichloro[N,N′-[(2,8-quinolinediyl-κN)diethylidyne]bis[2,6-dimethylbenzenamine-κN]]-, (SP-5-14)-; [2,8-bis(2,6-dimethyl-4-methyl-C 6 H 2 N═CCH 3 )C 9 H 5 N]iron dichloride, namely, Iron, dichloro[N,N′-[(2,8-quinolinediyl-κN)diethylidyne]bis[2,4,6-trimethylbenzenamine-κN]]-, and [2,8-bis(2,6-dimethyl-4-methyl-C 6 H 2 N═CCH 3 )C 9 H 5 N]cobalt dichloride, namely Cobalt, dichloro[N,N′-[(2,8-quinolinediyl-κN)diethylidyne]bis[2,4,6-trimethylbenzenamine-κN]]-.
[0030] In another aspect, the present invention is directed to a process for the hydrosilylation of a composition containing a silyl hydride and a compound containing at least one unsaturated group. The process includes: (i) contacting the composition with a metal complex of Formula (I), optionally in the presence of a solvent, to cause the silyl hydride to react with the compound containing at least one unsaturated group to produce a hydrosilylation product containing the metal complex; and (ii) optionally removing the metal complex from the hydrosilylation product.
[0031] In yet another aspect, the present invention is directed to an in-situ activation process for the hydrosilylation of a composition containing a silyl hydride and a compound containing at least one unsaturated group. The process includes the steps of: (i) providing a catalyst precursor being a complex having a structural formula according to Formula (II) as described above; (ii) activating the catalyst precursor by contacting the catalyst precursor with an activator in the presence of a liquid medium containing at least one component selected from the group consisting of a solvent, the silyl hydride, the compound containing at least one unsaturated group, and combinations thereof, thereby providing an activated catalyst; (iii) reacting the silyl hydride and the compound containing at least one unsaturated group in the presence of the activated catalyst to produce a hydrosilylation product containing the activated catalyst or derivatives thereof, wherein step (ii) is conducted shortly before, or at the same time as, step (iii); and (iv) optionally removing the activated catalyst or derivatives thereof.
[0032] These and other aspects will become apparent upon reading the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] In one embodiment of the invention, there is provided a complex of the Formula (I) or Formula (II) as illustrated above. In connection with these formulae, G can be Mn, Fe, Ni, or Co in all the valence states. Advantageously G is iron or cobalt. More advantageously M is Fe, such as Fe (II) and Fe (III).
[0034] As used herein, “alkyl” includes straight, branched and cyclic alkyl groups. Specific and non-limiting examples of alkyls include, but are not limited to, methyl, ethyl, propyl, and isobutyl. If not otherwise stated, the alkyl group suitable for the present invention is a C1-C18 alkyl, specifically a C1-C10 alkyl, more specifically, a C1-C6 alkyl.
[0035] By “substituted alkyl” herein is meant an alkyl group that contains one or more substituent groups that are inert under the process conditions to which the compound containing these substituent groups is subjected. The substituent groups also do not substantially interfere with the hydrosilylation processes described herein. If not otherwise stated, the substituted alkyl group suitable for the present invention is a C1-C18 substituted alkyl, specifically a C1-C10 substituted alkyl, more specifically a C1-C6 substituted alkyl. In one embodiment, the substituent is an inert functional group as defined herein.
[0036] By “aryl” herein is meant a non-limiting group of any aromatic hydrocarbon from which one hydrogen atom has been removed. An aryl may have one or more aromatic rings, which may be fused, connected by single bonds or other groups. Specific and non-limiting examples of aryls include, but are not limited to, tolyl, xylyl, phenyl, and naphthalenyl.
[0037] By “substituted aryl” herein is meant an aromatic group that contains one or more substituent groups that are inert under the process conditions to which the compound containing these substituent groups is subjected. The substituent groups also do not substantially interfere with the hydrosilylation processes described herein. Similar to an aryl, a substituted aryl may have one or more aromatic rings, which may be fused, connected by single bonds or other groups; however, when the substituted aryl has a heteroaromatic ring, the free valence in the substituted aryl group can be to a heteroatom (such as nitrogen) of the heteroaromatic ring instead of a carbon. If not otherwise stated, the substituents of the substituted aryl groups herein contain 0 to about 30 carbon atoms, specifically, from 0 to 20 carbon atoms, more specifically, from 0 to 10 carbon atoms. In one embodiment, the substituents are the inert functional groups defined herein.
[0038] By “alkenyl” herein is meant any straight, branched, or cyclic alkenyl group containing one or more carbon-carbon double bonds, where the point of substitution can be either at a carbon-carbon double bond or elsewhere in the group. Specific and non-limiting examples of alkenyls include, but are not limited to, vinyl, propenyl, allyl, methallyl, and ethylidenyl norbornane.
[0039] By “alkynyl” is meant any straight, branched, or cyclic alkynyl group containing one or more carbon-carbon triple bonds, where the point of substitution can be either at a carbon-carbon triple bond or elsewhere in the group.
[0040] By “unsaturated” is meant one or more double or triple bonds, Advantageously it refers to carbon-carbon double or triple bonds.
[0041] By “inert functional group” herein is meant a group other than alkyl, substituted alkyl, aryl or substituted aryl, which is inert under the process conditions to which the compound containing the group is subjected. The inert functional groups also do not substantially interfere with the hydrosilylation processes described herein. Examples of inert functional groups include halo (fluoro, chloro, bromo, and iodo), ether such as —OR 30 wherein R 30 is hydrocarbyl or substituted hydrocarbyl. Advantageously, the inert function group is a halo group.
[0042] “Heteroatom” herein is meant any of the Group 13-17 elements except carbon, and can include for example oxygen, nitrogen, silicon, sulfur, phosphorus, fluorine, chlorine, bromine, and iodine.
[0043] In some embodiments, the complexes disclosed herein include those of Formula (I) and Formula (II) having the following substituents: (1) each occurrence of R 1 and R 2 is independently hydrogen, or methyl; and/or (2) R 5 is hydrogen, methyl, ethyl, n-propyl or isopropyl groups; and/or (3) R 4 and R 6 are hydrogen; and/or (4) R 3 is methyl; and/or (5) R 7 to R 9 , R 30 and R 31 are hydrogen.
[0044] In connection with Formula (I), in some embodiments, each of L 1 and L 2 covalently bond to G through a carbon atom. In other embodiments, L 1 and L 2 do not contain beta hydrogen. Typically, the alpha carbon refers to the carbon that attaches to G. By extension, the beta carbon refers to the carbon that attaches to the alpha carbon. As used herein, beta hydrogen is meant the hydrogen attached to the beta carbon. Advantageously, L 1 and L 2 are each independently —CH 2 SiR 60 3 , wherein each occurrence of R 60 is C1-C18 alkyl, specifically C1-C10 alkyl, more specifically C1-C6 alkyl, C1-C18 substituted alkyl, specifically C1-C10 substituted alkyl, more specifically C1-C6 substituted alkyl, aryl or substituted aryl. In some embodiments, R 60 is a methyl or an ethyl group.
[0045] Also in connection with Formula (I), in some embodiments, L 1 and L 2 covalently bond to each other; and L 1 and L 2 taken together are represented by L 1 -L 2 . L 1 -L 2 typically contains at least two unsaturated sites per molecule and is bonded to the metal G through unsaturated sites. Examples of L 1 -L 2 include, but are not limited to, butadienes, 1,5-cyclooctadienes, dicyclopentadienes, norbornadienes, divinyl tetramethyl disiloxane, tretramethyltetravinylcyclotetrasiloxane, and trivinylcyclohexane.
[0046] In some embodiments, L 1 -L 2 contains at least four unsaturated sites per molecule. In this circumstance, it is possible to form a metal-2,8-bis(imino)quinoline dimer, (2,8-bis(imino)quinoline-metal-L 1 -L 2 -metal-2,8-bis(imino)quinoline), with each metal bonding to two unsaturated sites of L 1 -L 2 . Exemplary L 1 -L 2 for the metal-2,8-bis(imino)quinoline dimer is tetravinyltetramethyleyelotetrasiloxane.
[0047] In connection with Formula (II), X is an anion such as F − , Cl − , Br − , I − , CF 3 R 40 SO 3 − or R 50 COO − , wherein R 40 is a covalent bond or a C1-C6 alkyl group, and R 50 is a C1-C10 hydrocarbyl group. Advantageously X is F − , Cl − , Br − , or I − . In some embodiments, X is Cl − or Br − .
[0048] The methods to prepare the compounds represented by structural Formula (II) are known. For example, these compounds can be prepared by reacting a quinoline ligand of Formula (VI) with a metal halide, such as FeCl 2 or FeBr 2 , wherein Formula (VI) is represented by
[0000]
[0049] wherein
[0050] G is Mn, Fe, Ni, or Co;
[0051] each occurrence of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 30 and R 31 is independently hydrogen, an inert functional group, C1-C18 alkyl, C1-C18 substituted alkyl, aryl, or substituted aryl, wherein optionally each of R 1 to R 9 , R 30 and R 31 may independently contain at least one heteroatom;
[0052] optionally any two of R 3 , R 7 , R 8 , R 9 , R 30 , and R 31 vicinal to one another taken together may form a ring being a substituted or unsubstituted, saturated, or unsaturated cyclic structure;
[0053] Typically, the quinoline ligands of Formula (VI) are produced through condensation of 2,8-diacetylquinoline or its derivatives with an appropriate aniline. An exemplary method to prepare the compound of Formula (II) is described by Zhang et al. in Organometallics, 2010, 29 (5), pp 1168-1173, the disclosure of which is incorporated herein by reference in its entirety.
[0054] When L 1 and L 2 are C1-C18 alkyl, C1-C18 substituted alkyl, aryl, substituted aryl, the compound of Formula (I) can be prepared by reacting a complex of Formula (II) with L 1 , L 2 containing alkylating agents selected from the group consisting of alkali metal salts, alkaline earth metal salts, Grignards, aluminum alkyls, mercury alkyls, thallium alkyls.
[0055] As used herein, alkali metal salts include for example monoalkyl salts of lithium, sodium, potassium, rubidium and cesium. Alkaline earth metal salts include for example dialkyl salts of beryllium, magnesium, calcium, strontium and barium. Grignards suitable for the present invention include alkyl magnesium halides. Aluminum alkyls include for example trialkyl aluminum salts. Mercury alkyls refer to dialkyl mercury salts. Thallium alkyls include monoalkyl and trialkyl thallium salts.
[0056] When L 1 and L 2 are C2-C18 alkene or C2-C18 alkyne the compound of formula (I) can be prepared by reacting the compound of Formula (II) with L 1 and L 2 . When L 1 and L 2 taken together are L 1 -L 2 as defined above in connection with Formula (I), the compound of formula (I) can be prepared by reacting the compound of Formula (II) with L 1 -L 2 .
[0057] The metal complexes of Formula (I) and Formula (II) are useful for catalyzing industrially practiced hydrosilylation reactions. For example, (1) the crosslinking of silicone hydride fluids with terminally unsaturated polymers, and (2) hydrosilylation of terminally unsaturated amines with tertiary silanes. Accordingly, the metal complexes of the invention have utility in the preparation of useful silicone products, including, but not limited to, coatings, for example release coatings, room temperature vulcanizates, sealants, adhesives, products for agricultural and personal care applications, and silicone surfactants for stabilizing polyurethane foams.
[0058] When used as catalysts or catalyst precursors for the hydrosilylation reactions, the complexes of Formula (I) and Formula (II) can be unsupported or immobilized on a support material, for example, carbon, silica, alumina, MgCl 2 or zirconia, or on a polymer or prepolymer, for example polyethylene, polypropylene, polystyrene, or poly(aminostyrene). The metal complexes can also be supported on dendrimers.
[0059] In some embodiments, for the purposes of attaching the metal complexes of the invention to a support, it is desirable that at least one of R 7 , R 8 , R 9 , R 30 and R 31 of the metal complexes of Formulae (I) and (II) has a functional group that is effective to covalently bond to the support. Exemplary functional groups include but are not limited to SH, COOH, NH 2 or OH groups.
[0060] In certain embodiments, silica supported catalysts or catalyst precursors may be prepared via Ring-Opening Metathesis Polymerization (ROMP) technology as discussed in the literature, for example Macromol. Chem. Phys. 2001, 202, No. 5, pages 645-653, Journal of Chromatography A, 1025 (2003) 65-71, the content of which is incorporated herein by reference in its entirety.
[0061] Another way to immobilize catalysts or catalyst precursors on the surface of dendrimers is by the reaction of Si—Cl bonded parent dendrimers and functionalized metal complexes of Formula (I) or (II) in the presence of a base as illustrated by Kim et al. in Journal of Organometallic Chemistry 673 (2003) 77-83, the content of which is incorporated herein by reference in its entirety.
[0062] The complexes of Formula (I) can be used directly as catalysts for the hydrosilylation of a composition containing a silyl hydride and a compound having at least one unsaturated group. The process includes contacting the composition with a metal complex of Formula (I), either supported or unsupported, to cause the silyl hydride to react with the compound having at least one unsaturated group to produce a hydrosilylation product containing the metal complex catalyst. The hydrosilylation reaction can be conducted optionally in the presence of a solvent. If desired, when the hydrosilylation reaction is completed, the metal complex can be removed from the hydrosilylation product by magnetic separation, filtration, and/or other technologies known to a person skilled in the art.
[0063] Alternatively, the catalyst precursors of the invention, namely, the complexes of Formula (II) can be activated in-situ to generate reactive catalysts for the hydrosilylation of a composition containing a silyl hydride and a compound having at least one unsaturated group. The process includes the steps of: (i) providing a catalyst precursor being a complex having a structural formula according to Formula (II); (ii) activating the catalyst precursor by contacting the catalyst precursor with an activator in the presence of a liquid medium containing at least one component selected from the group consisting of a solvent, the silyl hydride, the compound containing at least one unsaturated group, and combinations thereof, thereby providing an activated catalyst; (iii) reacting the silyl hydride and the compound containing at least one unsaturated group in the presence of the activated catalyst to produce a hydrosilylation product containing the activated catalyst or derivatives thereof, wherein step (ii) is conducted shortly before, or at the same time as, step (iii); and (iv) optionally removing the activated catalyst or derivatives thereof.
[0064] As used herein, it is appreciated that “in-situ” means that (1) the catalyst precursor is activated while the catalyst precursor is present in the reaction mixture of the silyl hydride and the unsaturated substrate, or (2) the catalyst precursor is partially or fully activated before the partially or fully activated catalyst is present in the reaction mixture of the silyl hydride and the unsaturated substrate. It is intended to include the following situations: (a) contacting the catalyst precursor with an activator in the presence of a solvent to provide an admixture shortly before contacting the admixture with the silyl hydride and the unsaturated substrate, or (b) contacting the catalyst precursor with an activator in the presence of the silyl hydride to provide an admixture shortly before contacting the admixture with the unsaturated substrate, and if necessary, the remaining amount of the silyl hydride, or (c) contacting the catalyst precursor with an activator in the presence of the unsaturated substrate to provide an admixture shortly before contacting the admixture with the silyl hydride, and if necessary, the remaining amount of the unsaturated substrate, or (d) contacting the catalyst precursor with an activator at the same time as, or after, contacting the catalyst precursor with the silyl hydride and the unsaturated substrate.
[0065] By “shortly before”, it is meant a time period of less than 24 hours, preferably less than 2 hours, more preferably, less than 30 minutes depending upon the properties of the particular catalyst precursor and the activator used.
[0066] The activators suitable for the present invention include reducing agents having a reduction potential more negative than −0.6 v versus ferrocene in the presence of nitrogen, as described in Chem. Rev. 1996, 96, 877-910. In one embodiment, the reducing agents have a reduction potential in the range of −2.8 to −3.1 v versus ferrocene. Exemplary reducing agents include, but are not limited to, sodium naphthalenide, Mg(butadiene).2THF, NaEt 3 BH, LiEt 3 BH, Mg(Anthracenide).3THF, diisobutylaluminium hydride, and combinations thereof. In some embodiments, the reducing agent is Mg(butadiene).2THF or NaEt 3 BH.
[0067] In connection with the use of complexes of Formulae (I) and (II) in the hydrosilylation reaction, when the silyl hydride is Q u T v T p H D w D H x M H y M z , the compound containing an unsaturated group is an alkyne, a C2-C18 olefin, advantageously alpha olefins, an unsaturated aryl ether, a vinyl-functional silane, and combinations thereof.
[0068] As used herein, an “M” group represents a monofunctional group of formula R′ 3 SiO 1/2 , a “D” group represents a difunctional group of formula R′ 2 SiO 2/2 , a “T” group represents a trifunctional group of formula R′SiO 3/2 , and a “Q” group represents a tetrafunctional group of formula SiO 4/2 , an “M H ” group represents H g R′ 3-g SiO 1/2 , a “T H ” group represents HSiO 3/2 , and a “D H ” group represents R′HSiO 2/2 , where each occurrence of R′ is independently C1-C18 alkyl, C1-C18 substituted alkyl, wherein R′ optionally contains at least one heteroatom. As used herein, g has a value of from 0 to 3, each of p, u, v, y and z is independently from 0 to 20, w and x are independently from 0 to 1000, provided that p+x+y equals 1 to 3000, and the valences of the all the elements in the silyl hydride are satisfied. Advantageously, p, u, v, y, and z are from 0 to 10, w and x are from 0 to 100; wherein p+x+y equals 1 to 100.
[0069] In some embodiments, the silyl hydride has a structure of
[0000]
[0070] wherein each occurrence of R 7 , R 8 and R 9 is independently a C1-C18 alkyl, C1-C18 substituted alkyl, aryl, or a substituted aryl, R 6 is a C1-C18 alkyl, C1-C18 substituted alkyl, aryl, or a substituted aryl, and w and x are independently greater than or equal to 0.
[0071] When the silyl hydride is selected from the group consisting of R a SiH 4-a , (RO) a SiH 4-a , HSiR a (OR) 3-a , and combinations thereof, wherein each occurrence of R is independently C1-C18 alkyl, C1-C18 substituted alkyl, aryl or substituted aryl, wherein R optionally contains at least one heteroatom, a has a value of from 1 to 3, the compound containing an unsaturated group is selected from the group consisting of a unsaturated polyether such as an alkyl-capped allyl polyether, a vinyl functionalized alkyl-capped allyl or methallyl polyether, an alkyne, an unsaturated cycloalkyl epoxide, a terminally unsaturated acrylate or methyl acrylate, an unsaturated aryl ether, an unsaturated aromatic hydrocarbon, an unsaturated cycloalkane, a vinyl-functionalized polymer, a vinyl-functionalized silane, a vinyl-functionalized silicone, and combinations thereof.
[0072] Unsaturated polyethers suitable for the hydrosilylation reaction preferably are polyoxyalkylenes having the general formula:
[0000] R 1 (OCH 2 CH 2 ) z (OCH 2 CHR 3 ) w -OR 2 Formula (III)
[0000] or
[0000] R 2 O(CHR 3 CH 2 O) w (CH 2 CH 2 O) z -CR 4 2 —C≡C—C—CR 4 2 —(OCH 2 CH 2 ) z (OCH 2 CHR 3 ) w R 5 Formula (IV)
[0000] or
[0000] H 2 C═CR 4 CH 2 O(CH 2 OCH 2 ) z (CH 2 OCHR 3 ) w CH 2 CR 4 ═CH 2 Formula (V)
[0073] wherein R 1 denotes an unsaturated organic group containing from 2 to 10 carbon atoms such as allyl, methallyl propargyl or 3-pentynyl. When the unsaturation is olefinic, it is desirably terminal to facilitate smooth hydrosilylation. However, when the unsaturation is a triple bond, it may be internal. R 2 is vinyl, or a polyether capping group of from 1 to 8 carbon atoms such as the alkyl groups: CH 3 , n-C 4 H 9 , t-C 4 H 9 or i-C 8 H 17 , the acyl groups such as CH 3 COO, t-C 4 H 9 COO, the beta-ketoester group such as CH 3 C(O)CH 2 C(O)O, or a trialkylsilyl group. R 3 and R 4 are independently monovalent hydrocarbon groups such as the C1-C20 alkyl groups, for example, methyl, ethyl, isopropyl, 2-ethylhexyl, dodecyl and stearyl, or the aryl groups, for example, phenyl and naphthyl, or the alkaryl groups, for example, benzyl, phenylethyl and nonylphenyl, or the cycloalkyl groups, for example, cyclohexyl and cyclooctyl. R 4 may also be hydrogen. R 3 and R 4 are most preferably methyl. R 5 is hydrogen, vinyl or a polyether capping group of from 1 to 8 carbon atoms as defined herein above for R 2 . Each occurrence of z is 0 to 100 inclusive and each occurrence of w is 0 to 100 inclusive. Preferred values of z and w are 1 to 50 inclusive.
[0074] Vinyl functionalized silicones are Q u T v T p vi D w D vi x M vi y M z (Formula IX), wherein Q is SiO 4/2 , T is R′ SiO 3/2 , T vi is R 12 SiO 3/2 , D is R′ 2 SiO 2/2 , D vi is R′ R 12 SiO 2/2 , M vi is R 12 g R′ 3-g SiO 1/2 , M is R′ 3 SiO 1/2 ; R 12 is vinyl; each occurrence of R′ is independently C1-C18 alkyl, C1-C18 substituted alkyl, aryl, substituted aryl, wherein R′ optionally contain at least one heteroatom; each g has a value of from 1 to 3, p is from 0 to 20, u is from 0 to 20, v is from 0 to 20, w is from 0 to 5000, x is from 0 to 5000, y is from 0 to 20, and z is from 0 to 20, provided that v+p+w+x+y equals 1 to 10,000, and the valences of all of the elements in the compound containing at least one unsaturated group are satisfied.
[0075] In some embodiments, suitable vinyl functionalized silicones are represented by Formula (X):
[0000]
[0076] wherein each occurrence of R 10 is independently a C1-C18 alkyl, C1-C18 substituted alkyl, vinyl, aryl, or a substituted aryl, n is greater than or equal to zero.
[0077] Vinyl functional silanes are R 14 a SiR 15 4-a , wherein R 14 is C1-C18 alkyl, C1-C18 substituted alkyl, aryl, substituted aryl, wherein R 14 optionally contains at least one heteroatom, and R 15 is vinyl, where a is 0 to 3.
[0078] Alkenes suitable for the hydrosilylation reaction are not particularly limited. Advantageously, suitable olefins are C2-C18 alpha olefins such as 1-octene. Exemplary terminally unsaturated amines include allyl amine, N,N-dimethylallylamine. Exemplary unsaturated cycloalkyl epoxides include limonene oxides, and vinyl cyclohexyl epoxides such as 4-vinyl-1-cyclohexene 1,2-epoxide. Exemplary unsaturated alkyl epoxides include 1,2-epoxy-7-octene, 1,2-epoxy-9-decene, butadiene monoxide, 2-methyl-2-vinyloxirane, 1,2-epoxy-5-hexene, and allyl glycidyl ether. Exemplary unsaturated aromatic hydrocarbons include styrene. Exemplary unsaturated cycloalkanes include trivinyl cyclohexane. Exemplary unsaturated polymers include terminally unsaturated polyurethane polymers.
[0079] Solvents suitable for the hydrosilylation reaction of the invention include, but are not limited to non-polar, aliphatic and aromatic hydrocarbon solvents. The temperature range for the process of the hydrosilylation is from −50° C. to 250° C., advantageously from −10 to 150° C. The silyl hydride and the compound having at least one unsaturated group are typically mixed in a molar ratio ranging from about 0.5:2 to about 1:0.8, advantageously from about 0.8:1.3 to about 1:0.9, and more advantageously in a molar ratio of 1:1 of the reactive groups. For the in-situ activation process, the molar ratio of the reducing agent or the activator with respect to the catalyst precursor is between about 5:1 and 0.8:1, advantageously between about 2:1 and 0.8:1, more advantageously between about 1.2:1 to about 0.8:1. The amount of catalyst in the reaction mixture calculated on ppm level of the metal in the total mass of the mixture is 1-10,000 ppm, advantageously 10-5000 ppm, more advantageously 20-2000 ppm. For an in-situ activation, a nitrogen atmosphere is preferred, but is not absolutely necessary.
[0080] The metal complexes of Formula (I) and the activated metal complexes of Formula (II) of the invention are efficient and selective in catalyzing hydrosilylation reactions. For example, when the metal complexes of the invention are employed in the hydrosilylation of an alkyl-capped allyl polyether and a compound containing an unsaturated group, the reaction products are essentially free of unreacted alkyl-capped allyl polyether and its isomerization products. In one embodiment, the reaction products do not contain the unreacted alkyl-capped allyl polyether and its isomerization products. Further, when the compound containing an unsaturated group is unsaturated amine compound, the hydrosilylation product is essentially free of internal addition products and isomerization products of the unsaturated amine compound. As used herein, “essentially free” is meant no more than 10 wt %, preferably 5 wt % based on the total weight of the hydrosilylation product. “Essentially free of internal addition products” is meant that silicon is added to the terminal carbon.
[0081] The metal complexes of the invention can also be used in a process for preparing a silylated polyurethane, which includes the step of contacting terminally unsaturated polyurethane polymer with a silyl hydride in the presence of a complex of Formula (I), or activated complex of Formula (II).
[0082] The following examples are intended to illustrate, but in no way limit the scope of the present invention. All parts and percentages are by weight and all temperatures are in degrees Celsius unless explicitly stated otherwise.
EXAMPLES
General Considerations
[0083] All air- and moisture-sensitive manipulations were carried out using standard vacuum line, Schlenk, and cannula techniques or in an MBraun inert atmosphere drybox containing an atmosphere of purified nitrogen. Solvents for air- and moisture-sensitive manipulations were initially dried and deoxygenated using literature procedures. See for example Pangborn et al., J. Organometallics 1996, 15, 1518.
EXAMPLE 1
Hydrosilylation of 1-Octene with Methylbis(trimethylsilyloxy)silane (MD H M) using Mg(butadiene).2THF as an activator and ( 2,6-Me2 Quinoline)FeCl 2 as a Catalyst Precursor
[0084] Catalyst precursor, [2,8-bis(2,6-dimethyl-C 6 H 3 N═CCH 3 )C 9 H 5 N]iron dichloride, hereafter( 2,6-Me2 Quinoline)FeCl 2 , which structure is shown below, was synthesized according to: Zhang, S.; Sun, W.; Xiao, T.; Hao, X. Organometallics (2010), 29 (5), 1168-1173.
[0000]
[0085] In an inert atmosphere, to a scintillation vial with stir bar was added 0.100 g (0.89 mmol) of 1-octene and 0.192 g (0.86 mmol, 0.97 eq to olefin) of MD H M, followed by 0.004 g (0.01 mmol) of ( 2,6-Me2 Quinoline)FeCl 2 (1 mol % to silane), and 0.003 g (0.015 mmol ) of Mg(butadiene).2THF. The reaction was stirred for one hour, quenched in air and analyzed by Gas Chromatography (GC) and NMR, showing 70% conversion to the desired hydrosilylation product. Only the desired anti-Markovnikov addition product and unreacted starting materials were observed. No evidence was seen for any isomerization of the 1-octene or any hydrosilylation products derived therefrom.
EXAMPLE 2
Hydrosilylation of 1-Octene with Methylbis(trimethylsilyloxy)silane (MD H M) using NaEt 3 BH as an activator and ( 2,6-Me Quinoline)FeBr 2 as a Catalyst Precursor
[0086] Catalyst precursor, [2,8-bis(2,6-dimethyl-C 6 H 3 N═CCH 3 )C 9 H 5 N]iron dibromide, hereafter ( 2,6-Me2 Quinoline)FeBr 2 , was prepared as follows: A scintillation vial was charged with 0.150 g (0.357 mmol) of 2,8-bis(1-aryliminoethyl)quinoline and 0.077 g (0.357 mmol) of iron dibromide, followed by the addition of 10 mL of THF. The reaction was stirred overnight, at which time the volume of THF was reduced to about 5 mL. Then 10 mL of pentane was added, inducing precipitation of the product. The green powder was collected on a frit and dried under reduced pressure, yielding 0.210 g (92%) of ( 2,6-Me2 Quinoline)FeBr 2 .
[0087] Hydrosilylation: A procedure similar to that in Example 1 was used, but with 0.100 g (0.89 mmol) of 1-octene and 0.192 g (0.86 mmol, 0.97 eq to olefin) of MD H M, followed by 0.010 g (0.02 mmol) of ( 2,6-Me2 Quinoline)FeBr 2 (2 mol % to silane), and 0.040 mL (0.04 mmol) of 1M NaEt 3 BH in toluene. The reaction was stirred for one hour, quenched in air and analyzed by GC, showing 70% conversion to the desired hydrosilylation product. Only the desired anti-Markovnikov addition product and unreacted starting materials were observed. No evidence was seen for any isomerization of the 1-octene or any hydrosilylation products derived therefrom.
EXAMPLE 3
Hydrosilylation of 1-Octene with Methylbis(trimethylsilyloxy)silane (MD H M) using Mg(butadiene).2THF as an activator and ( 2,6-Me2 Quinoline)FeBr 2 as a Catalyst Precursor
[0088] A procedure similar to that in Example 1 was used, but with 0.100 g (0.89 mmol) of 1-octene and 0.192 g (0.86 mmol, 0.97 eq to olefin) of MD H M, followed by 0.010 g (0.02 mmol) of ( 2,6-Me2 Quinoline)FeBr 2 (2 mol % to silane) and 0.007 g (0.03 mmol) of Mg(butadiene).2THF. The reaction was stirred for one hour at room temperature (23° C.), quenched in air and analyzed by GC, showing 50% conversion to the desired hydrosilylation product. Only the desired anti-Markovnikov addition product and unreacted starting materials were observed. No evidence was seen for any isomerization of the 1-octene or any hydrosilylation products derived therefrom.
EXAMPLE 4
Preparation of ( 2,6-Me2 Quinoline)Fe(CH 2 SiMe 3 ) 2
[0089] To a round bottomed flask charged with 0.075 g (0.12 mmol) of ( 2,6-Me2 Quinoline)FeBr 2 was added approximately 10 mL of diethyl ether. The flask was chilled to −35° C. and a solution containing 0.023 g (0.24 mmol) of LiCH 2 SiMe 3 and approximately 10 mL of diethyl ether was added. The slurry was stirred and allowed to warm to ambient temperature. After stirring for one hour, the reaction mixture was filtered through Celite® and the volatiles were removed in vacuo. The resulting burgundy solid was washed with approximately 5 mL of cold pentane yielding 0.060 g (73%) of ( 2,6-Me2 Quinoline)Fe(CH 2 SiMe 3 ) 2 . 1 NMR δ=294.41, 112.07, 58.47, 48.61, 32.19, 10.19, −8.85, −10.02, −10.56, −11.06, −12.19, −18.13, −20.54, −29.84, −36.02, −44.48, −159.63. The structure of ( 2,6-Me2 Quinoline)Fe(CH 2 SiMe 3 ) 2 is represented by Formula (I) wherein R 1 , R 2 , R 3 are —CH 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 30 , and R 31 are H, and both L 1 and L 2 are —CH 2 Si(CH 3 ) 3 .
EXAMPLE 5
Hydrosilylation of 1-Octene with Methylbis(trimethylsilyloxy)silane (MD H M) using ( 2,6-Me2 Quinoline)Fe(CH 2 SiMe 3 ) 2
[0090] In an inert atmosphere, to a scintillation vial with stir bar was added 0.100 g (0.89 mmol) of 1-octene and 0.192 g (0.86 mmol, 0.97 eq to olefin) of MD H M, followed by 0.010 g (0.02 mmol) of ( 2,6-Me Quinoline)Fe(CH 2 SiMe 3 ) 2 . The reaction was stirred for one hour at 60° C., quenched in air and analyzed by GC, showing 40% conversion to the desired hydrosilylation product. No evidence was seen for any isomerization of the 1-octene or any hydrosilylation products derived there from.
[0091] While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the invention as defined by the claims appended hereto. | Disclosed herein are manganese, iron, cobalt, or nickel complexes containing 2,8-bis(imino)quinoline ligands and their use as catalysts or catalysts precursors for hydrosilylation reactions. | 2 |
BACKGROUND OF THE INVENTION
[0001] The invention relates generally to a method for operating a gas turbine during select operating conditions such as under-frequency operation through extraction of air from the compressor.
[0002] Large increases in the electrical power consumptive demand placed upon an electrical power distribution grid will tend to reduce the electrical operational frequency of the grid, causing an “under-frequency” event. For example, a heavy or sudden electrical demand may cause a particular power distribution grid having a nominal operational frequency of 50 Hz to momentarily operate at 49 Hz. In conventional electrical power generation systems that utilize one or more heavy-duty industrial gas turbine for supplying electrical power to the grid, the physical speed of each turbine supplying power to the grid is synchronized to the electrical frequency of the grid. Unfortunately, as the physical speed of a gas turbine decreases with other things being equal, its power output correspondingly decreases. Consequently, during an under-frequency event, a gas turbine will tend to output a lower power. In the past, a common practice in response to a power grid under-frequency event (occurrence) is to increase the firing temperature of the gas turbine to produce more power in an effort to maintain a predetermined level of output power. Unfortunately, such over-firing of the gas turbine may reduce the operational life expectancy of various hot gas path components within the turbine.
[0003] Grid code regulations typically require that power production equipment have the capability to maintain load during under-frequency excursions. Various regions around the world have different requirements that must be satisfied in order for power equipment to be considered compliant. Typically, gas turbine generators meet these requirements by increasing firing temperature to maintain generator output within requirements. Increases in firing temperature increase power output at a given pressure ratio, which works adequately when the gas turbine does not approach any operating limits such as maximum pressure ratio capability or maximum inlet guide vane (IGV) position. A firing temperature increase is typically achieved by an increase the fuel flow supplied to the combustor. All things otherwise equal, the increase in fuel flow results in a higher pressure at the turbine inlet, which in turn applies backpressure on the compressor. Eventually, adding more flow results in a compressor pressure limit, which typically is observed by limiting the flow through the turbine through the diversion of compressor discharge air to inlet (inlet bleed heating) and/or reduction of fuel flow (and consequently firing temperature). However, this method has limited capability to meet grid code requirements for cool ambient conditions and/or low Btu fuels (e.g. syngas) applications, due to operability limits encountered by the gas turbine compressor.
[0004] Some conventional gas turbines, used for power generation, incorporate variable inlet guide vanes (IGV). Such variable stator vanes provide the ability to adjust compressor airflow by changing incidence angle (i.e., the difference between the air angle and the mean line angle at the compressor blade leading edge) in the front stages of the compressor. These variable IGVs permit an acceptable compressor surge-free operation margin to be maintained. Typically, maintaining surge-free operation is a vital operational criterion of the compressor component for gas turbines.
[0005] Wickert et al. (U.S. Pat. No. 6,794,766) provides a method for over-firing of gas turbines equipped with variable stator vanes (blades) to compensate for power output during under-frequency events. Wickert utilizes the variable stator vanes to increase the amount of airflow consumed by the compressor component in a predefined manner so to preclude and/or minimize a decrease in the level of output power generated during a grid under-frequency event and maintaining a safe margin during such an event. However, not all gas turbines are equipped with variable stator vanes to permit employing such a technique. Further, this action alone may not be sufficient if the maximum vane position is reached and a pressure ratio limit is encountered simultaneously while attempting to increase output. In this situation, other action must be taken to alleviate the pressure limit.
[0006] It would therefore be desirable to utilize an operational method, which would improve the power output during select operations and result in improved grid code compliance during under-frequency operation.
BRIEF DESCRIPTION OF THE INVENTION
[0007] Briefly, in accordance with one aspect of the present invention, in a gas turbine electric power generator where rotational speed of the gas turbine is synchronized to the electrical frequency of a power grid and the gas turbine includes a compressor component, an air extraction path, and means for controlling an amount of compressor air extraction, a method is provided for controlling output power produced by a gas turbine. The method includes initiating the compressor air extraction and controlling the amount of compressor air extraction.
[0008] In accordance with another aspect of the present invention, in a gas turbine electric power generator where rotational speed of the gas turbine is synchronized to the electrical frequency of a power grid and the gas turbine includes a compressor component, an air extraction path, and means for controlling an amount of compressor air extraction, a method is provided for controlling output power produced by a gas turbine. The method includes initiating compressor air extraction and controlling the amount of compressor air extraction during a power grid under-frequency condition through at least one of a discharge path to atmosphere, a discharge path to energy recovery equipment; reducing diluent flow to the combustor and raising the firing temperature.
[0009] In accordance with a further aspect of the present invention, the gas turbine electric power generator wherein a rotational speed of a gas turbine is synchronized to the electrical frequency of a power grid, a control system is provided that controls initiating compressor air extraction and controlling extracting compressor air to increase margin to compressor pressure ratio limits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0011] FIG. 1 illustrates a typical gas turbine generator set incorporating standard air, fuel, and combustion product flow.
[0012] FIG. 2 illustrates a gas turbine generator set with a plurality of elements that permit gas turbine operation during under-frequency operation through use of air extraction.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The previously described aspects of the present invention have many advantages, including using compressor air extraction to provide a simple and effective method of operating the gas turbine during under-frequency events.
[0014] FIG. 1 illustrates combined cycle gas turbine equipment 5 , including a compressor 50 , a combustor 52 , a gas turbine 54 , a heat recovery steam generator (HRSG) 56 and it associated steam turbine 58 . Air, under ambient conditions, enters the axial flow compressor 50 at air intake 10 . The compressed air 12 enters the combustor 52 where fuel is injected at 28 and combustion occurs. The combustion mixture 14 leaves the combustor and enters the gas turbine 54 . In the turbine section, energy of the hot gases is converted into work. This conversion takes place in two steps. The hot gases are expanded and the portion of the thermo-energy is converted into kinetic energy in the nozzle section of the gas turbine 54 . Then a portion of the kinetic energy is transferred to the rotating bucket of the bucket section of the gas turbine 54 and converted to work. A portion of the work developed by the gas turbine 54 is used to drive the compressor 50 whereas the remainder is available for generating electric power. The exhaust gas 16 leaves the gas turbine and flows to the HRSG 56 , providing energy to produce steam for driving steam turbine 58 . Electric power is generated from the gas turbine driven generator 60 and the steam turbine driven generator 62 and supplied to an electric power grid 64 .
[0015] The Brayton cycle is the thermodynamic cycle upon which gas turbines operate. Every Brayton cycle can be characterized by pressure ratio and firing temperature. The pressure ratio of the cycle is the compressor discharge pressure at 12 divided by the compressor inlet pressure at 10 . The firing temperature is defined as the mass flow mean total temperature at the stage 1 nozzle trailing edge plane. It is well known that an elevated firing temperature in the gas turbine is a key element in providing a higher output per unit mass flow and therefore a higher output power. The maximum pressure ratio that the compressor can deliver in continuous operation is commonly defined in terms of a margin from a surge pressure ratio line. Compressor surge is defined as a low frequency oscillation of flow where the flow separates from the blades and reverses flow direction
[0016] FIG. 2 shows different extraction points and discharge paths for air extraction on the combined cycle gas turbine equipment 5 , which may be used alone or in combination. In one aspect of the invention, extraction air would be taken from the compressor 50 outlet and/or combustor 52 at 20 and vented to atmosphere at 22 via discharge to atmosphere control valve 40 . Compressor air may be further extracted at 34 from the compressor upstream of the compressor outlet. Specific location points for extraction of air from the gas turbine depend on the particular device. For example, air extraction from the General Electric “E” Series gas turbines is typically from the outlet of the compressor while the air extraction point from the General Electric “F” Series gas turbines is typically from the combustor. In another aspect of the invention, extracted air may be discharged to air extraction energy recovery equipment 66 through discharge to energy recovery equipment control valve 42 . The air extraction energy recovery equipment 66 may include an air separation unit (ASU) 68 and other recovery equipment 76 . The ASU 68 separates N 2 and O 2 in the air. The O 2 may then be used in the production of syngas fuel for a gas turbine in a gasification process while N 2 may be used as a diluent or vented. Still another aspect of the invention provides extraction of compressor 50 outlet air through inlet bleed control valve 44 to the inlet side of the compressor 50 at 26 .
[0017] Air extraction alone will typically result in a decrease in power output, all other factors being equal, due to decreased mass flow rate input. However, simultaneously with the air extraction, additional fuel is supplied to the combustor 52 . at 28 . The reduction in compressor airflow through air extraction provides relief of the compressor pressure ratio limits typically encountered. Because compressor airflow extraction provides relief of the compressor pressure ratio limits, increased fuel flow can be accommodated within the compressor pressure ratio limits. The resulting gas turbine output power is increased while maintaining margin to the compressor pressure ratio. During under-frequency conditions, employing air extraction with increased firing will increase gas turbine output power to assist in meeting grid code requirements.
[0018] Yet another aspect of the present invention reduces diluents inflow 30 to the combustor 52 . Lower diluent flow to the combustor reduces the overall fuel/air flow rate. With a lower diluent flow rate, the margin to the compressor-pressure ratio limit is increased and more fuel may be added in its place to increase power.
[0019] In still a further aspect of the present invention, the combustor 52 may be co-fired with a richer alternative fuel at 32 , such as natural gas or distillate or blends with the richer alternative fuels, if a primary fuel is leaner as is typical of syngas and process fuels. Because the co-firing with the richer alternative fuel permits a higher power output with the same fuel flow rate, higher output power can be achieved with a lower overall fuel/air flow rate, thereby maintaining a margin to the compressor pressure ratio limit.
[0020] Individual elements described above for permitting a higher power output from the gas turbine may be used alone or in combination.
[0021] Efficient operation of the gas turbine requires that a number of critical turbine operating parameters be processed to determine optimal settings for controllable parameters such as fuel flow and intake air flow. Such operating parameters include compressor inlet and outlet temperatures and pressures, exhaust temperature and pressure and the like. One example of a control system or means for controlling a gas turbine is the General Electric Co.'s Speedtronic™ Mark V Control System, which is designed to fulfill all gas turbine control, including speed and load control functions. Such a control system is described in Andrew et al. (U.S. Pat. No. 6,226,974). Andrew describes a controller that is coupled to receive input from a plurality of sources such as operations controls and a plurality of sensors coupled to the turbine and power output means. The controller is coupled to a system of turbine actuators that are used to maintain or establish a particular turbine operating regime. The actuators include, but are not limited to, an air flow control actuator and a fuel flow control actuator.
[0022] In an aspect of the present invention, a similar control system to Andrew et al. may be employed, with or without IGV control. The control system may also employ controls over one or a combination of control valves. Referring to FIG. 2 , the control system 80 may control additional actuating controls, such as discharge to atmosphere control valve 40 , discharge to energy recovery equipment control valve 42 and inlet bleed control valve 44 that extract part of the air flowing from the discharge of the compressor for improving margin to compressor pressure ratio limits, thereby allowing increased firing for power control. The control system 80 initiates the compressor air extraction and controls the amount of compressor air extraction from discharge to atmosphere control valve 40 , discharge to energy recovery equipment control valve 42 , and inlet bleed valve 44 . Further, the control system 80 will further control fuel input to the combustor 70 , diluent control 72 , and alternate fuel control 74 . Because such sensing and actuating controls are well known in the art, they need not be described herein with respect to actuator controls for air extraction operation.
[0023] While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | In a gas turbine electric power generator where rotational speed of the gas turbine is synchronized to the electrical frequency of a power grid and the gas turbine includes a compressor component, an air extraction path, and means for controlling an amount of compressor air extraction, a method is provided for controlling output power produced by a gas turbine. The method includes initiating compressor air extraction and controlling the amount of compressor air extraction. | 5 |
BACKGROUND
This invention relates generally to drilling devices and, more particularly, to an expandable diameter drill bit having a torsion spring for biasing one or more blades outwardly such that a hole being drilled is enlarged.
Rotary drilling devices are used to bore a generally cylindrical hole into the ground to a depth at which a fluid may be extracted, such as water, oil, natural gas, or the like. Sometimes an existing well needs to be re-drilled, cleaned out, or the diameter expanded. A rotary drill may include one or more blades that scrape or dig into the ground surface as the drill rotates. The blades often wear out, break, or otherwise fail and must be replaced, especially when operated at high speed. Another problem with drilling devices is that a drill bit having one diameter may be used and then replaced with a drill bit having a larger diameter in order to increase the diameter of the well.
Although existing rotary drilling devices are presumably effective to drill subsurface wells, they are less effective in operating to increase the diameter of the hole. For instance, some expanding diameter drill bits urge their blades outwardly by centrifugal force and, as a result, require high speed rotation which may not be possible in some subsurface conditions or if debris is building up too quickly within a hole.
Therefore, it would be desirable to have an expandable diameter drill bit having one or more blades that are automatically biased outwardly by respective torsion springs. Further, it would be desirable to have an expandable diameter drill bit having a construction that is less susceptible to blade breakage and more effective in cutting through rock.
SUMMARY
An expandable diameter drill bit according to the present invention includes a cutting blade having a receiving end and a contacting end, the receiving end having a pivot shaft and the contacting end having a tip. A drill bit includes a drill head body having an upper attachment portion and a lower body portion, the lower body portion defining a blade opening for receiving the receiving end of the cutting blade and a bolt receiving hole on each of two opposing sides transverse the blade opening. The drill bit includes a torsion spring having a helical coil, a first blade leg, and a second body leg. The blade bolt passes through the bolt receiving holes and the pivot shaft and is secured into position with a blade bolt set screw. The first blade leg is coupled to the cutting blade with a spring retainer bolt, the second body leg is coupled to the drill head body, and the torsion spring biases the blade outwardly from the drill head body.
The drill bit 10 may be inserted into a hole with the purpose of expanding the hole diameter as it is lowered therein. The drill bit is spun around such that the blades cut away at the edges of the hole. As the diameter of the hole becomes larger, the oppositely biased torsion springs force the blades outward, thus causing the hole to become even larger.
Therefore, a general object of this invention is to provide an expandable diameter drill bit for efficiently drilling a well beneath the surface of the Earth.
Another object of this invention is to provide an expandable diameter drill bit, as aforesaid, in which a pair of blades is pivotally movable between a retracted configuration not extending outwardly from a drill body and an extended configuration extending outwardly from the drill body.
Still another object of this invention is to provide an expandable diameter drill bit, as aforesaid, in which each cutting blade is naturally biased toward the extended configuration by a respective torsion spring.
Yet another object of this invention is to provide an expandable diameter drill bit, as aforesaid, in which each cutting blade may be coated with or include materials that cut more effectively through subsurface compositions and debris.
A further object of this invention is to provide an expandable diameter drill bit, as aforesaid, that cuts more effectively through subsurface compositions and debris.
A still further object of this invention is to provide an expandable diameter drill bit, as aforesaid, in which each cutting blade includes serrated teeth.
Other objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, embodiments of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an expandable diameter drill bit according to a present embodiment of the present invention illustrated in an expanded configuration;
FIG. 2 a is a front view of the expandable diameter drill bit as in FIG. 1 ;
FIG. 2 b is a side view of the expandable diameter drill bit as in FIG. 2 a;
FIG. 2 c is a section view taken along line 2 c - 2 c of FIG. 2 b;
FIG. 2 d is an isolated view on an enlarged scale taken from FIG. 2 c;
FIG. 2 e is an isolated view on an enlarged scale taken from FIG. 2 c;
FIG. 2 f is an isolated view on an enlarged scale taken from FIG. 2 c;
FIG. 3 a is an exploded view of the expandable diameter drill bit as in FIG. 1 ;
FIG. 3 b is an isolated view on an enlarged scale taken from FIG. 3 a;
FIG. 3 c is an isolated view on an enlarged scale taken from FIG. 3 a;
FIG. 3 d is an isolated view on an enlarged scale taken from FIG. 3 a;
FIG. 3 e is an isolated view on an enlarged scale taken from FIG. 3 a;
FIG. 4 a is a front view of the expandable diameter drill bit according to the present invention illustrated in a retracted configuration; and
FIG. 4 b is a side view of the expandable diameter drill bit as in FIG. 4 a.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An expandable diameter drill bit and method of use will now be described with reference to FIGS. 1 to 4 b of the accompanying drawings. The drill bit 10 may generally include a drill head body 100 and a plurality of blades 200 secured to the drill head body 100 with a bolt and set screw combination and held in tension with the drill head body 100 via tension springs 300 .
With reference to FIGS. 3 a and 3 b , the drill head body 100 serves as the structural support for the expandable blades 200 . The drill head body 100 may have an upper threaded portion 105 for attaching the drill bit to various devices useful for guiding the drill bit underground and a lower body portion 110 for attaching the blades 200 to the drill bit 10 . Although not required, the upper threaded portion 105 may be generally conically shaped as shown in the figures.
An outside edge 107 of the upper threaded portion 105 may be inserted into, for example, a drill string (not shown). The threaded portion 105 may be configured such that when the drill bit 10 is connected to the drill string and in use the drill bit 10 does not become loosened. Other means for ensuring semi-permanent connection to the drill string (or other guiding device) is contemplated within the scope of the present invention. It shall also be understood that drill bits generally have a shortened lifespan due to the conditions under which they are used, and therefore, as will be appreciated by those skilled in the art, it may be preferable that the drill bit 10 is removable from the drill string (or other guiding device) at the end of its life.
The upper threaded portion 105 terminates at an inside edge 109 of a top face of the lower body portion 110 . The lower body portion 110 may define blade openings 112 for accepting receiving ends 205 of the blades 200 . The blade openings 205 may be separated by a divider 115 for ensuring proper positioning of the blades 200 and to prevent the blades 200 from rubbing against each other during use.
Bolt receiving holes 120 in opposing sides of the drill head lower body portion 110 and though the center of the divider 115 may generally correspond to holes 210 (pivot shafts) in receiving ends 205 of the blades 200 . Referring now to FIG. 3 c , a threaded end 131 of a blade bolt 130 may be inserted through a first bolt receiving hole 120 a ( FIG. 4 a ) in the drill head lower body portion 110 , through the hole 210 (pivot shaft) in the receiving end 205 of a first blade 200 , through the hole in the divider 115 , through the hole 210 (pivot shaft) in the receiving end 205 of a second blade 200 , and through a second bolt receiving hole 120 b in the drill head lower body portion 110 . A head 132 on the end opposite the threaded end 131 of the blade bolt 130 may subsequently come to rest along an outer perimeter 119 of the first receiving hole 120 a to keep the blade bolt 130 in its preferred position.
A channel 133 ( FIG. 3 c ) may be cut around a perimeter of the blade bolt 130 at a length L of the bolt 130 such that when the bolt 130 is inserted through the drill bit lower body portion 110 as described above, the channel 133 is at a position corresponding generally to the hole in the divider 115 . A blade bolt set screw hole 125 ( FIG. 3 e ) in one or both outside ends of the divider 115 may receive a blade bolt set screw 135 , which may fit within the channel 133 in the blade bolt 130 . In some embodiments, it may be preferable for the blade bolt set screw 135 to fit within the channel 133 to prevent the blade bolt 130 from shifting laterally but still allow the blade bolt 130 to rotate within the bolt receiving holes 120 a , 120 b . In other embodiments, it may be desirable for the blade bolt set screw 135 to be tightened such that the blade bolt 130 is prevented from both shifting laterally and rotating.
The lower body portion 110 may further be equipped with a fluid discharge hole 128 . Fluids are often used to reduce friction, provide buoyancy to the drill string, and remove cuttings from the well bore. As the well bore in which the drill is operating is flooded with fluids, the fluid discharge hole 128 may allow for fluids to be discharged away from the drill head body 100 .
The blades 200 provide the means by which surface material is displaced to form a hole, and in some particular embodiments, a well bore hole. Each blade 200 may be generally rectangular at the receiving end 205 and culminate at a tip at the surface contacting end 215 . The tip may have a rounded configuration as shown in the drawings although a pointed tip may also be used in other embodiments not shown). An upper corner 212 of the blade at the receiving end 205 may be rounded to facilitate rotation of the blade 200 about the blade bolt 130 while situated inside of the blade openings 112 .
Outer edges 214 of the blades may be serrated to increase the performance of the blades. Serrated edges may be superior to plain edges because serrated edges tend to grab and cut the material as the blades come into contact with the surface. The blades may be made of any material strong enough to withstand the high forces exerted on the blades as they rotate and cut away at the surface. Exemplary materials include steel, steel alloys, tungsten carbide, cubic boron nitride, et cetera.
In addition to the blades themselves, the edges may be coated in a material exhibiting superior hardness properties thereby increasing the effectiveness of the blades and the life of the drill. In some embodiments, the edges 214 may additionally or alternately be equipped to receive an insert 220 , such as that shown in FIG. 3 a . The insert 220 may also be constructed of a material exhibiting superior hardness properties. Exemplary materials include tungsten carbide, cubic boron nitride, diamond, et cetera.
It should be noted that the blades may be any desired length based on the requirements of a particular project (e.g., 20″, 25″, 30″, 35″, 40″, 45″, etc.). Additionally, while the embodiments described herein focus on the use of two opposing blades, additional or fewer blades could be used depending on the particular project.
With reference to FIG. 2 c , tension springs 300 may act to keep the blades 200 in tension with respect to the drill head body 100 . The springs 300 may be, for example, helical torsion springs having a central coil 305 with a first blade leg 310 extending along a length of the blade 200 and a second body leg 315 extending toward and attaching to the base 100 . The central coil 305 may fit into a recess 240 in the pivot shaft 210 and the first blade leg 310 may fit into a recess 242 in the blade 200 ( FIGS. 2 e and 3 d ). The first blade leg 310 may be secured into place via one or more spring retainer bolts 320 ( FIG. 2 f ). The second body leg may be inserted into a cavity 140 in the drill head body 100 ( FIG. 2 d ).
When the springs 300 are in full tension, the blades 200 are in a retracted position as illustrated in FIGS. 1 and 2 a . When retracted, such as to about a 4″ diameter, the drill bit 10 may be inserted into a ground hole that is intended to be drilled or enlarged. In a retracted position, the blades 200 may not exhibit any substantial hole-widening capabilities. However, the mechanical energy stored in the springs 300 as a result of the central coil 305 constantly acts to push the blades outward or away from the retracted position. FIG. 2 a illustrates the springs 300 pushing the blades 200 outward toward an expanded configuration ( FIG. 1 ). The mechanical energy can thus be altered by modifying the central coil 305 (e.g., increasing the tension or decreasing the tension in the spring). Therefore, as the blades 200 cut away at the interior surface of a hole, the blades may be pushed further outward as a result of the tension springs 300 , thereby increasing the diameter of the hole in the surface. It may be preferable for the blades 200 to extend in opposite directions from each other to obtain the highest possible degree of surface displacement. In an embodiment, a diameter of the blades in the extended configuration may be about 24″ although other diameters would be effective depending on individual blade lengths.
In use, the drill bit 10 is inserted into a hole with the purpose of expanding the hole diameter. The blades 200 may first be in the retracted configuration so as to fit into the hole as described above. The drill bit 10 is spun around such that the blades 200 cut away at the edges of the hole. As the hole becomes larger (i.e. has a larger diameter), the springs 300 force the blades 200 outwardly, thus causing the hole to become even larger.
While many methods of manufacturing the drill head body 100 and blades 200 are contemplated within the scope of the present invention, some exemplary methods include die casting, molding, forging, extruding, machining, et cetera.
Many different arrangements are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention are described herein with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the disclosed improvements without departing from the scope of the present invention. Further, it will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. The description should not be restricted to the specific described embodiments. | An expandable diameter drill bit includes a cutting blade having receiving and contacting ends, the receiving end having a pivot shaft and the contacting end having a tip. A drill bit includes a drill head body having an upper attachment portion and a lower body portion, the lower body portion defining a blade opening for receiving the receiving end of the cutting blade and a bolt receiving hole on opposing sides transverse the blade opening. The drill bit includes a torsion spring, a first blade leg, and a second body leg. The blade bolt passes through the bolt receiving holes and the pivot shaft and secured with a set screw. The first blade leg is coupled to the cutting blade with a spring retainer bolt, the second body leg is coupled to the drill head body, and the torsion spring biases the blade outwardly from the drill head body. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new and useful improvements in screens for obscuring accident sites.
2. Brief Description of the Prior Art
It is well known by safety officials and police officers concerned with safety and with maintaining the flow of motor vehicle traffic that many traffic jams and secondary accidents are attributable to the slowdown and jamming of traffic at accident sites. Whenever an accident occurs, it not only slows traffic in the traffic lane where the accident occurs, but also results in the slowing of traffic in the opposite lane as a result of motorists slowing to look at the site of the accident.
At the present time, no equipment is available to obscure the site of an accident. The closest thing to an accident-obscuring screen would be the use of a blanket or tarpaulin to cover a body of a deceased or injured person lying on the ground.
Collapsible fences and screens are known for temporary use in obscuring athletic fields, playgrounds, building sites and the like. However, no portable screens are known to be available of a size and construction capable of being carried and erected by a single individual at the site of an accident.
SUMMARY OF THE INVENTION
An object of this invention is to promote highway safety and free flow of highway traffic by providing means to obscure the site of an accident.
Another object of this invention is to promote highway safety and free flow of motor vehicle traffic by providing an accident screen in the form of a collapsible kit including supporting posts and an elongated fabric screen for obscuring an accident site.
An accident screen kit comprises an elongated fabric screen of light-reflective material, preferably of alternating stripes. The material is in the form of an elongated strip which is supported at each end by a folding post of a light weight tubular plastic material. The posts are each provided with mounting cables for supporting the same in a position obscuring the site of an accident from the view of passing motorists. The fabric is also provided with a plurality of elongated slots which permit passage of air and thus prevent wind damage. The use of this accident screen obscures accident sites and prevents the inevitable slowdown in traffic passing the site of an accident. The accident screen is highly portable and may be handled and erected by one person.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in elevation of the accident screen of this invention illustrated in position of normal usage.
FIG. 2 is a view in elevation of one of the collapsible supporting poles for the accident screen shown in FIG. 1.
FIG. 3 is a view in end elevation of one of the collapsible poles as shown in FIG. 2.
FIG. 4 is a view in horizontal cross section taken on the section line 4--4 of FIG. 3.
FIG. 5 is a view of the accident screen shown in FIG. 1 in the process of being folded up.
FIG. 6 is a schematic view of the accident screen of FIG. 1 rolled up for storage and contained in a carrying bag.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings by numerals of reference, and more particularly to FIG. 1, there is shown an accident screen 10 comprising an elongated strip of fabric 12 supported by end posts 14 and 16 to obscure the site of an accident as indicated by the dotted outline 18 of a wrecked motor vehicle. The elongated strip of fabric 12 is five feet wide by thirty-six feet long or larger, as needed. The strip of fabric 12 is constructed of alternate panels 20 and 22, respectively, which are of a reflective material for safety. Panel 20 is preferably of a safety-orange reflective material, while panel 22 is preferably of a white reflective material. Obviously, other colors could be used so long as they provide an adequate warning. It is essential that suitable safety striping be used with alternate colors or colors alternating with white, of a highly reflective material, to provide an adequate warning of a possible hazard. The strip of fabric 12 is also provided with a plurality of slots 24 which allow the wind to blow through the panels and protect the fabric screen against wind damage. The details of the supporting posts 14 and 16 and the method of attachment of the fabric screen thereto and the method of support for the posts is illustrated in FIGS. 2 to 4.
In FIG. 2, there is shown more detail with respect to the construction of supporting post 14. Supporting post 16 is constructed identically to post 14 but is turned over, end for end, in making the connection to the opposite end of the strip of fabric 12.
Post 14 consists of two sections, 26 and 28, of hollow plastic tubing. The sections of tubing 26 and 28 are preferably three feet long, three inch O.D., and forty gauge wall thickness plastic tubing (preferably polypropylene) or the like. Tubing sections 26 and 28 are connected together by hinge 30 which is secured in place by a plurality of screws 32 or the like.
In FIG. 3, there is shown an end view or left elevation of post 14. In this view, it is seen that upper tubing portion 26 is provided with a pair of slots 34 and 36 and lower tubing portion 28 is provided with a pair of slots 38 and 40. These slots are preferably about one fourth inch wide by twelve inches long. Inside the tubing portions 26 and 28 there are positioned a plurality of balls 42 which secure one end of each of the cables used to support the respective posts. Ball 42 is of wood or plastic or the like and is drilled to receive an eye bolt 44. Eye bolt 44 is secured in ball 42 by nut 46 or the like. Eye bolt 44 has an eyelet 48 at the opposite end and has one end of cable 50 secured therein. Each of the cables 50 (8 cables being provided) is connected to an eye bolt secured in one of the balls 42. The opposite end of each cable is secured to the eyelet end 52 of a safety hook 54 which has a spring closure 56. The balls 42 which support the cable are preferably about one inch to one and one-half inch diameter. The cable 50 is preferably three-sixteenth inch steel cable which is three feet in length. Upper tube 26 is provided with a one-fourth inch I.D. by four inch long tube 57 which may be secured on a backing plate 58 and secured by screws 60 to tube 26 adjacent the hinged end thereof. The lower tube 28 is provided with a one-fourth inch I.D. by four inch long tube secured adjacent the hinged end in the same manner as tube 56 and aligned therewith. Tubes 56 and 62 are aligned when tubes 26 and 28 are in the position shown in FIGS. 2 and 3. Tubes 57 and 62 receive a retaining pin 64 which is supported on a steel cable 66 and secured to upper tube 26 as indicated at 68.
On the side of tubes 26 and 28 opposite the slots, there are provided a plurality (preferably 6) of slip hooks (eye bolts with spring loaded opening portions) 70. Slip hooks 70 are secured in the wall of tubing 26 or 28 by threaded connection or by a bolt and washer retaining the slip hook in the desired position. Slip hooks 70 are fitted into grommets 72 in the hemmed end portion 74 of the fabric strip 12.
When this safety screen is broken down it is folded at each end. The view in FIG. 5 shows intermediate position in the folding of the equipment. When folded, the posts are then rolled up in the fabric strip 12 and are preferably supported as a roll 75 in a fabric bag 76 provided with a drawstring closure 78.
OPERATION
The manner of use and operation of this equipment should be obvious from the foregoing description. However, a more detailed description of its purpose and manner of use will be provided for clarification.
It is well known among highway safety officials and police officers concerned with traffic safety that one major cause of traffic jams, and in some cases the cause of secondary accidents, is the slowing of traffic to look at the site of an accident. When an accident occurs on or near a highway, it not only tends to slow the traffic in the land adjacent the accident, but also causes the traffic moving in the opposite direction to slow as a result of drivers wishing to see what has happened. It is a common sight on major highways for an accident to occur and immediately cause traffic to back up in the immediate vicinity of the accident. Almost immediately, the traffic will begin to back up in the lane moving in the opposite direction from the accident as well as in the lane of traffic in which the accident has occurred. The safety screen which is described above is capable of erection by one person and is easily carried by a safety official or traffic police officer to the site of an accident. The equipment is light and portable and easy to erect. The dimensions and sizes for the various components given above are merely illustrative and may obviously be varied for different areas of intended use. The dimensions given are suitable for use in obscuring the site of most traffic accidents.
On reaching the site of an accident, the police officer, or other safety official, would remove the roll 74 of equipment from bag 76 (or other carrying case) and unroll it to its full length. The supporting posts 14 and 16 are each then unfolded to a fully straightened out position as shown in FIGS. 1, 2 and 3. It should be noted that the supporting cables 50 are stuffed inside the hollow tube portions 26 and 28 during storage. These cables are, of course, removed before the posts are erected. When the posts are straightened out, as shown, the strip of fabric 12 is opened as indicated in FIGS. 1. It should be noted that the hinges 30 on posts 14 and 16 cause the folding of posts 14 and 16 in a direction resulting in the reflective surface of the strip of fabric 12 being folded to the inside. When the posts 14 and 16 are erected, as shown, retaining pin 64 (which hangs loose on cable 66) is inserted through aligned tubes 57 and 62 to secure the tubing portions 26 and 28 in an erected position.
The accident screen is then placed over and/or around the site of the accident to obscure it from the view of passing traffic. The cables 50 (8 cables being provided for each of the posts 14 and 16) are then pulled out to full length and are attached to any convenient fixed object to support posts 14 and 16, respectively, in an erected position. The cables can be attached to a tree or telephone pole or building or another motor vehicle or any suitable fixed object. The cables are easy to attach by means of the spring hooks 54 which permit direct attachment to any suitable object or by looping the end of the cable around an object and hooking the cable back on itself. The substantial number of cables provided permits attachment to a variety of different fixed objects or fixed positions to steady the posts 14 and 16 in a vertical (or other suitable) position. The posts may be supported with the fabric stretched taut, as shown in FIG. 1, or, if necessary, the fabric may be draped around the accident site and the posts hooked to each other.
The strip of fabric 12 is made of light reflective material and alternates in safety stripes, preferably alternating orange and white. This is effective to obscure the site of the accident and yet provides a warning to prevent a further accident by another vehicle running through the barrier screen. As noted above, the fabric 12 is provided with slots 24 which permit the wind to blow through the screen without revealing the nature of the object behind the screen. This equipment is large enough to obscure an entire accident site including one or more motor vehicles as well as any deceased or injured persons lying about.
When the need for the accident screen has passed, the supporting cables 50 are disconnected. Retaining pins 64 are removed from tubes 56 and 62 to permit posts 14 and 16 to be broken down. Posts 14 and 16 are then folded at hinges 30, as seen in FIG. 5, and the screen fabric 12 is folded lengthwise with the reflective surface folded inward. Cables 50 are stuffed into the end of tubes 26 and 28 for storage. The folded supporting posts are then rolled up in the folded screen fabric 12 into a roll 74 and placed in bag 76 (or other suitable container) for storage.
While this invention has been described fully and completely, with special emphasis upon a single preferred embodiment, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | An accident screen kit comprises an elongated fabric screen of light-reflective material, preferably of alternating stripes. The material is in the form of an elongated strip which is supported at each end by a folding post of a light weight tubular plastic material. The posts are each provided with mounting cables for supporting the same in a position obscuring the site of an accident from the view of passing motorists. The fabric is also provided with a plurality of elongated slots which permit passage of air and thus prevent wind damage. The use of this accident screen obscures accident sites and prevents the inevitable slowdown in traffic passing the site of an accident. The accident screen is highly portable and may be handled and erected by one person. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method of preparing phytosterols from tall oil pitch, including the use of distillation techniques to isolate a phytosterol concentrate that can by crystallization yield high purity phytosterols using a solvent comprising alcohol or a combination of alcohols, and that may include water.
BACKGROUND TO THE INVENTION
[0002] Tall oil pitch is obtained from the black liquor of alkaline digestion of coniferous wood, most notably the kraft process. The black liquor is typically concentrated and settled to yield soap skimmings that contain sodium salts of fatty acids, sodium salts of resin acids and unsaponifiables. The latter group of substances include fatty alcohols, free sterols, steryl esters, and fatty acid esters. In kraft pulp mills, the collected soap is routinely acidulated with a mineral acid such as sulphuric acid to yield an oil phase and a water phase. The oil phase contains free fatty acids, resin acids and unsaponifiables; it is commonly known as crude tall oil. Typically, the amount of unsaponifiables can range from 10 to 35% by weight of the crude tall oil, depending on the species and quality of coniferous wood used. The water phase containing sodium sulphate and any lignin entrained in the original soap is normally recycled back to the pulp mill chemical recovery system. In the subsequent recovery of desired fatty acids and resin acids, crude tall oil is typically evaporated under low pressure conditions to yield a light phase, known as depitched tall oil, containing mainly fatty acids and resins, and a heavy phase, known as tall oil pitch, containing a small amount of fatty and rosin acids and a substantial amount of the original unsaponifiables.
[0003] Phytosterols can be isolated from either tall oil soap (sometimes referred to as soap skimmings) or from tall oil pitch. It is understood that the manufacture of sterols from tall oil soap has been practiced commercially by Oy Kaukas AB, Lappeenranta, Finland since 1981. The technologies are those based on the refining of tall oil soap with a combination of low molecular weight ketones, alcohols and hydrocarbons; for example, as disclosed by Holmbom et al. in U.S. Pat. No. 3,965,085 granted on Jun. 22, 1976. The refined tall oil soap is then extracted and crystallized using a combination of polar and non-polar solvents, for example, as taught by Johansson et al. in U.S. Pat. No. 4,044,031 granted on Aug. 23, 1977 and Hamunen in U.S. Pat. No. 4,422,974 granted on Dec. 27, 1983. Those methods of manufacture of pure tall oil sterols requires the soap skimmings to be relatively free of entrained black liquor and the use of multiple solvents which entails several separate solvent recovery systems. The adjustment of precise solvent compositions to maintain optimal operation for each processing stage is complex. In U.S. Pat. No. 4,153,622 granted on May 8, 1979, Lamminkari et al. disclose the use of acetone and activated carbon to extract sterols from tall oil soap, in which the acetone extract is subsequently evaporated for dissolution in ethanol for the final recovery of sterols.
[0004] The recovery of sterols from tall oil pitch has been studied for many years. In U.S. Pat. No. 2,715,638, Albrecht et al. teach the use of an amount of dilute alkaline solution to neutralize the fatty and rosin acids in tall oil pitch but in an amount to saponify the sterol ester. The remaining organic phase is then separated and saponified with an alcoholic alkaline solution to convert steryl esters into free sterols for subsequent dilution in hot water to precipitate the sterols by cooling. The product purity was indicated to be in the range of 83%. In U.S. Pat. Nos. 3,691,211 and 3,840,570 Julian teaches the use of a mixture of alcohol, water and hydrocarbon to extract tall oil pitch, then saponify the hydrocarbon phase with an alkali metal base, and finally dissolve the saponified material in a polar solvent for the recovery of phytosterols. The procedure is cumbersome as it involves several solvent extraction steps with different polar and non-polar solvents. The solvent recovery systems for at least polar and non-polar solvents are complex.
[0005] In U.S. Pat. No. 5,097,012 granted on Mar. 17, 1992, Thies et al. disclose a method for the isolation of sterols from crude tall oil by water extraction at elevated temperatures and pressures.
[0006] In U.S. Pat. No. 3,943,117 granted on Mar. 9, 1976, Force discloses a process for saponifying tall oil pitch in which a water-soluble cationic amine is used in conjunction with an alkali. In U.S. Pat. No. 4,524,024 granted on Jun. 18, 1985, Hughes teaches the hydrolysis of tall oil pitch at elevated temperatures to increase the recovery of fatty acids from tall oil pitch. In U.S. Pat. No. 3,887,537 granted on Jun. 3, 1975, Harada et al. disclose the recovery of fatty acids and rosin acids from tall oil pitch by first saponifying tall oil pitch with an alkali metal base and a low molecular weight alcohol, and then introducing the reacted mixture into a thin film evaporator to remove low-boiling matter such as water, alcohol use and light unsaponifiables. The bottom fraction from the first evaporator is next fed to a second thin film evaporator in which the unsaponifiables including sterols are removed as the light ends and a molten soap is recovered as the bottom fraction. Fatty acids and rosin acids are recovered from the molten soap fraction by acidulation conventionally with a mineral acid. In U.S. Pat. No. 3,926,936 granted on Dec. 16, 1975, Lehtinen teaches the recovery of fatty acids and rosin acids from tall oil pitch by reacting tall oil pitch with an alkali at 200 to 300 degrees Celsius, in the amount of 5 to 25% of tall oil pitch, prior to vacuum distillation of the heated mixture to recover the fatty acids and rosin acids in the distillate fraction.
SUMMARY OF THE INVENTION
[0007] In a broad aspect of the present invention there is provided a new and improved method of preparing phytosterols from tall oil pitch containing steryl esters, the method comprising the steps of:
[0008] (a) converting the steryl esters to free phytosterols while in the pitch to produce a modified pitch containing the free phytosterols;
[0009] (b) removing light ends from the modified pitch by evaporation to produce a bottom fraction containing the free phytosterols;
[0010] (c) evaporating the bottom fraction to produce a light phase distillate containing the free phytosterols;
[0011] (d) dissolving the distillate in a solvent comprising an alcohol to produce a solution containing the free phytosterols;
[0012] (e) cooling the solution to produce a slurry with the free phytosterols crystallized in the slurry; and,
[0013] (f) washing and filtering the slurry to isolate the crystallized phytosterols.
[0014] Preferably, the step of converting the steryl esters to free phytosterols comprises the steps of saponifying the tall oil pitch with an alkali metal base, neutralizing the saponified pitch with an acid, and heating the neutralized pitch to remove water. The resulting pitch with such water removed defines the modified pitch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The FIGURE shows a schematic flow diagram for the preparation of high purity phytosterol crystals from tall oil pitch in accordance with the present invention.
DESCRIPTION OF PREFERRED EMBODIMENT
[0016] In accordance with the present invention, the isolation of phytosterols from tall oil pitch first requires converting steryl esters present in the pitch to free phytosterols while in the pitch. The result is a modified pitch containing free phytosterols.
[0017] It is contemplated that the required conversion may be accomplished by various methods. In the FIGURE, the conversion step is indicated by block 30 (shown in broken outline) which receives an incoming feed of tall oil pitch 1 and produces modified pitch 11 as an output. The presently preferred method of conversion involves the use of an alkali base treatment and is indicated by the elements contained within block 30 .
[0018] As depicted within block 30 , tall oil pitch 1 is added with an alkali metal base 2 into a reactor 3 . The amount of alkali metal base relative to the tall oil pitch preferably should be sufficient to facilitate substantially complete saponification of the tall oil pitch.
[0019] Cost effectiveness considerations will generally favor the use of a water solution of an alkali metal base such as sodium hydroxide, potassium hydroxide or a combination thereof. These compounds or combinations will provide a relatively high alkalinity for a relatively reasonable cost. If such compounds or combinations are used, then the stoichiometric proportion of alkali metal base 2 to tall oil pitch 1 that theoretically is required to achieve complete conversion typically may be in the neighborhood of about 1% by weight. Of course, the precise amount will depend upon the specific characteristics of tall oil pitch 1 , and these characteristics may vary from one batch of feed or source to another. As well, and again depending upon the specific characteristics of tall oil pitch 1 , it will be recognized that a significant portion of alkali metal base 2 may be consumed by reaction with constituents of pitch 1 other than steryl esters. Accordingly, to provide a strong driving force for the reaction, and to better ensure efficient conversion of the steryl esters that are present, a significantly higher proportion of alkali metal base 2 to tall oil pitch 1 may be considered desirable. Typically, this proportion may be in the range of 5 to 15% by weight.
[0020] Mixing is sustained in reactor 3 with sufficient to vigor to maintain contact between pitch 1 and alkali metal base 2 . Typically, an operating temperature in the range of 100 to 250 deg. C. for a period in the range of 60 minutes (at the higher temperature) to 300 minutes (at the lower temperature) will suffice to facilitate the desired saponification.
[0021] Following saponification in reactor 3 , the saponified pitch 4 is discharged into a second reactor 6 . An acid 5 is also added to reactor 6 .
[0022] Acid 5 may be a simple organic acid such as acetic acid or formic acid, both of which are commercially practical. As well, acid 5 may be a mineral acid such as sulphuric acid, hydrochloric acid or phosphoric acid. These are relatively strong mineral acids and are favored over weaker acids such as boric acid. Nitric acid is a possibility. However, it is contemplated that undesirable nitration may occur.
[0023] Sufficient acid 5 is added to reactor 6 such that the mixture reaches a water phase pH between 4 and 7, and preferably between 5 and 7. Although the mixture should be monitored during the additive process, the latter typically will be achieved when the amount of acid is about 20% in excess of the stoichiometric amount required for the neutralization of the residual alkali metal base present in saponified pitch 4 .
[0024] With gentle stirring in reactor 6 , an operating temperature in the range of 10 to 100 deg. C. for a period in the range of 1 hour (at the higher temperature) to 10 hours (at the lower temperature) will typically suffice to facilitate the desired neutralization. Then, with continued gentle stirring, the mixture in reactor 6 is maintained at a temperature of about 95 deg. C. for approximately 120 minutes to effect the bulk disengagement of water from the organic phase. Excess water 7 is drawn off and the resulting neutralized pitch 8 is introduced into a third reactor 9 for further processing.
[0025] Notwithstanding the removal of excess water 7 in reactor 6 , a relatively high water content may still subsist. By heating mixture 8 in reactor 9 , preferably under vacuum conditions, water 10 is further stripped off to produce a modified pitch 11 containing free phytosterols and preferably comprising less than 1% by weight water.
[0026] Modified pitch 11 is introduced into an ultra-low pressure evaporator 12 operating in the range of 0.1 to 10 millibars pressure (but preferably not more than 1 millibar) and at a temperature in the range of 160 to 280 deg. C., for the removal of 1 to 15% of light ends 13 in the modified pitch. These light ends will comprise a high proportion of the fatty and resin acids found in the original tall oil pitch 1 .
[0027] The bottom fraction 14 of modified pitch 11 contains the free phytosterols and is removed from evaporator 12 and introduced into a second ultra-low pressure wiped film evaporator 15 . Evaporator 15 serves to distill free phytosterols present in fraction 14 into light phase distillate 16 . To do so efficiently, it preferably is operated at a pressure in the range of 0.01 to 1.0 millibars pressure and at a temperature in the range of 180 to 300 deg. C. Distillate 16 also contains fatty alcohols, fatty acids, rosin acids and high molecular weight wax esters. A bottom fraction 17 is discarded and may be used as a waste fuel or feedstock for other industries.
[0028] Distillate 16 is introduced into a further reactor 18 where it is heated and stirred until dissolution has occurred in an added solvent 21 . Solvent 21 includes alcohol, preferably a low molecular weight monohydric alcohol such as methanol, ethanol or 2-propanol, or a combination of such alcohols. As well, the solvent may include water.
[0029] Effective dissolution of free phytosterols has been found to occur at about 65 deg. C. Other temperatures may of course be used, but it has to be borne in mind that the solubility of the phytosterols will decrease as the temperature is lowered.
[0030] When dissolution has occurred, the solution is cooled in reactor 18 together with high speed mixing to produce a slurry 19 with free phytosterols crystallized in the slurry. Typically, the temperature at which crystallization is effected may be in the range of 0 to 35 deg. C.
[0031] The cooled slurry 19 is washed and filtered to dryness with a filtration apparatus 20 advantageously using added solvent 21 like that used in reactor 18 . The result is a yield of high purity phytosterol crystals 22 and spent solvent filtrate 23 , the latter of which may be recovered for recycling and reuse.
[0032] In more detail, the practice of the invention may be seen from the following examples:
EXAMPLE 1
[0033] 9,598 kg of tall oil pitch were saponified with 1,325 kg NaOH at 12.0% concentration solution, at 146 deg. C. for 120 minutes, under vigorous mixing conditions. The weight ratio of sodium hydroxide (dry basis) to tall oil pitch was 0.138. The reacted mixture was then neutralized with 1,188 kg of 85% concentration phosphoric acid. After continued heating at 146 deg. C. and gentle stirring for 210 minutes, 6,600 kg of water was drawn off from the bottom of the reactor. The pH of the reactor bottom water was 6.4. The partially dewatered mixture containing about 37.5% water was transferred to a second reactor for vacuum stripping of residual moisture. The vacuum reactor was operated at 149 deg. C. at an average pressure of 300 mm Hg. The reaction was completed in 300 minutes. The dried, saponified and neutralized tall oil pitch had a moisture content of 0.4% by wt.
[0034] Table 1 summarizes the percentage of phytosterols present in free form at various stages in the procedure.
TABLE 1 Processing Stage % phytosterols in free form Tall oil pitch feed 26.8 After saponification 83.0 After neutralization 81.0 After vacuum stripping 84.6
[0035] The phytosterols mostly in free from are now ready for separation from the modified tall oil pitch.
EXAMPLE 2
[0036] A sample of tall oil pitch was saponified, neutralized and dewatered by the method described in Example 1. The modified tall oil pitch was found to have a composition of 141 mg free phytosterols/g and 164 mg total phytosterols/g. The modified tall oil pitch was pre-heated to about 100 deg. C. for feeding into a series of 0.1 square meter wiped evaporators (manufactured by UIC GmbH, Germany). The distillate from each evaporation stage was recovered for the analysis of free phytosterols by gas-liquid chromatography (GLC).
[0037] Table 2 summarizes free phytosterol production results for four tests runs (A1, A2, A3 and A4) under differing conditions of feed rate, temperature and pressure.
TABLE 2 Test Number A1 A2 A3 A4 Stage 1 Evaporation Tall oil pitch feed, kg/hr 15.5 15.6 11.5 15.6 Temperature, deg. C. 225 225 225 220 Pressure, mbar 5.94 6.53 6.45 2.08 Distillate yield, % by wt. <1 <1 <1 1.90 Free phytosterals in Stage 1 distil- 18 18 18 18 late, mg/g Stage 2 Evaporation Feed from above Stage 1 residue, 15.6 15.6 11.5 15.3 kg/hr Temperature, deg. C. 251 269 252 265 Pressure, mbar 0.32 0.37 0.07 0.07 Distillate yield, % by wt. relative 40.4 49.7 49.6 51.2 to Stage 1 feed Free phytosterols in Stage 2 distil- 248 250 254 262 late, mg/g Free phytosterols recovered in 71.1 88.1 89.4 94.8 Stage 2 distillate, % of free phyto- sterols present in tall oil pitch
EXAMPLE 3
[0038] Samples of Stage 2 distillate from Example 2 were crystallized in laboratory jar tests by heating the distillate-solvent mixture to 65 deg. C. The mixtures were cooled to 30 to 35 deg. C. to yield a slurry containing the desired phytosterol crystals. The weight ratio of organic solvent to distillate was 1.5:1.0. The cooled slurry was then filtered through 50 micrometer filter paper, under vacuum. The filtered cake was then washed twice with solvent in an amount equal to 1.5 times the weight of distillate sample used for crystallization. The wash solvent had the same composition as that used for crystallization. Washing of the cake was conducted at ambient temperature. The washed cake was then dried at 90 deg. C. for 60 minutes prior to weighing and GLC analysis.
[0039] Table 3 comparatively summarizes crystal purities and crystal yields for test runs A1, A2, A3 and A4, firstly, utilizing methanol as the solvent and, secondly, utilizing a mixture of methanol and 2-propanol as the solvent
TABLE 3 Stage 2 Distillate Test Number A1 A2 A3 A4 Solvent: 100% methanol Crystal purity, mg pure phytosterols/g 983 970 956 933 dry cake Crystal yield, % based on phytosterols 41.9 43.2 46.3 48.0 in test distillate Solvent: 70% methanol and 30% 2-propanol Crystal purity, mg pure phytosterols/g 1000 972 997 997 dry cake Crystal yield, % based on phytosterols 30.5 31.9 33.8 38.6 in test distillate
EXAMPLE 4
[0040] A sample of Stage 2 distillate from Test Number A4 was re-distilled further in a wiped film evaporator. The distillate feed had a composition of 262 mg free phytosterols/g and 264 mg total phytosterols/g. The feed was pre-heated to about 100 deg. C. for feeding into the 0.1 square meter wiped film evaporator (manufactured by UIC GmbH, Germany). The distillate samples were recovered for the analysis of free phytosterols by gas-liquid chromatography (GLC).
[0041] Table 4 summarizes free phytosterol production results for four tests runs (B1, B2, B3 and B4) under differing conditions of feed rate, temperature and pressure.
TABLE 4 Test Number B1 B2 B3 B4 Distillate feed, kg/hr 8.7 8.7 15.1 14.9 Temperature, deg. C. 216 230 240 249 Pressure, mbar 0.16 0.15 0.29 0.26 Distillate yield, % by wt. 74.4 85.6 79.8 86.4 Free phytosterols in distillate, mg/g 248 275 260 266 Free phytosterols recovered from 70.7 91.2 80.4 88.4 distillate feed, % by wt.
EXAMPLE 5
[0042] Distillate samples from Example 4 were collected for laboratory scale crystallization using the procedure described previously in Example 3. The solvent used was 100% methanol. Table 5 comparatively summarizes crystal purities and crystal yields for test runs B1, B2, B3 and B4.
TABLE 5 Stage 3 Distillate Test Number B1 B2 B3 B4 Crystal purity, mg pure phytosterols/g 992 972 986 978 dry cake Crystal yield, % based on phytosterols 36.9 40.7 37.9 44.8 in test distillate
EXAMPLE 6
[0043] Distillate from Stage 3, distillation Test Number B4, was crystallized using other mixtures of alcohol or alcohol and water. The test procedure was identical to that described in Example 3. The free phytosterol content of test distillate was 266 mg/g.
[0044] Table 6 comparatively summarizes crystal purities and crystal yields for five test runs C1, C2, C3, and C4.
TABLE 6 Stage 3 Distillate Test No. B4 C1 C2 C3 C4 Methanol, % by wt. 15.0 12.6 70 58.7 Ethanol, % by wt. 85.0 71.3 0.0 0.0 2-propanol, % by wt. 0.0 0.0 30.0 25.1 Water, % by wt. 0.0 16.1 0.0 16.2 Crystal purity, mg pure phytosterols/g 999 985 991 975 dry cake Crystal yield, % based on phytosterols 34.4 46.3 39.1 58.0 in test distillate
EXAMPLE 7
[0045] Distillate from Stage 3 distillation Test Number B4 was again crystallized in the laboratory using alcohols, and the test procedure was again identical to that described in Example 3, except that the crystallization was conducted at 0 deg. C. The weight ratio of organic solvent to distillate was varied. Wash solvent was maintained at ambient temperature. The free phytosterol content of test distillate was 266 mg/g.
[0046] Table 7 comparatively summarizes crystal purities and crystal yields for two test runs D1 and D2 utilizing the same methanol-ethanol solvent, but with different proportions of solvent to distillate.
TABLE 7 Stage 3 Distillate Test No. B4 D1 D2 Methanol, % by wt. 15.0 15.0 Ethanol, % by wt. 85.0 85.0 Proportion of solvent to distillate, by wt. 1.6 3.0 Crystal purity, mg pure phytosterols/g dry cake 983 965 Crystal yield, % based on phytosterols in test distillate 66.3 66.6
[0047] As noted above, it is contemplated that the conversion of steryl esters present in tall oil pitch 1 to free phytosterols while in the pitch may be accomplished by various methods. The method described involves the use of an alkali base treatment. Although experimentation may be required, and although there may be difficulties, other methods that may be tried include water hydrolysis treatment and acid hydrolysis treatment of the tall oil pitch. | A method of preparing phytosterols from tall oil pitch containing steryl esters comprises the steps of converting the steryl esters to free phytosterols while in the pitch to produce a modified pitch containing the free phytosterols; removing light ends from the modified pitch by evaporation to produce a bottom fraction containing the free phytosterols; evaporating the bottom fraction to produce a light phase distillate containing the free phytosterols; dissolving the light phase distillate in a solvent comprising an alcohol to produce a solution containing the free phytosterols; cooling the solution to produce a slurry with the free phytosterols crystallized in the slurry; and, washing and filtering the slurry to isolate the crystallized phytosterols. | 2 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application, Ser. No. 08/679,547 now abandoned issued Jul. 12, 1996 which is a continuation in part of U.S. patent application, Ser. No. 08/628,835, filed Apr. 5, 1996, which is a continuation in part of U.S. patent application, Ser. No. 08/511,825, filed Aug. 7, 1995, now U.S. Pat. No. 5,962,923, issued Oct. 5, 1999.
FIELD OF THE INVENTION
The invention relates generally to semiconductor integrated circuits. In particular, the invention relates to a barrier layer formed between a metal and a semiconductor, and the covering of the barrier layer with a conductor.
BACKGROUND OF THE INVENTION
Modern semiconductor integrated circuits usually involve multiple layers separated by dielectric (insulating) layers, such as of silicon dioxide or silica, often referred to simply as an oxide layer, although other materials are being considered for the dielectric. The layers are electrically interconnected by holes penetrating the intervening oxide layer which contact some underlying conductive feature. After the holes are etched, they are filled with a metal, such as aluminum, to electrically connect the bottom layer with the top layer. The generic structure is referred to as a plug. If the underlying layer is silicon or polysilicon, the plug is a contact. If the underlying layer is a metal, the plug is a via.
Plugs have presented an increasingly difficult problem as integrated circuits are formed with an increasing density of circuit elements because the feature sizes have continued to shrink. The thickness of the oxide layer seems to be constrained to the neighborhood of 1 μm, while the diameter of the plug is being reduced from the neighborhood of 0.25 μm or 0.35 μm to 0.18 μm and below. As a result, the aspect ratios of the plugs, that is, the ratio of their depth to their minimum lateral dimension, is being pushed to 5:1 and above.
Filling such a hole with a metal presents two major difficulties.
The first difficulty is filling such a hole without forming an included void, at least with a filling process that is fast enough to be economical and at a low enough temperature that doesn't degrade previously formed layers. Any included void decreases the conductivity through the plug and introduces a substantial reliability problem. Chemical vapor deposition (CVD) is well known to be capable of filling such narrow holes with a metal, but CVD is considered to be too slow for a complete filling process. Physical vapor deposition (PVD), alternatively called sputtering, is the preferred filling process because of its fast deposition rates. However, PVD does not inherently conformally coat a deep and narrow hole. A fundamental approach for applying PVD to deep holes is to sputter the metal on a hot substrate so that the deposited material naturally flows into the narrow and deep feature. This process is typically referred to as reflow. However, high-temperature reflow results in a high thermal budget, and in general the thermal budget needs to be minimized for complex integrated circuits. Further, even at high temperatures, the metal does not always easily flow into a very narrow aperture.
The second difficulty is that an aluminum contact is not really compatible with the underlying semiconductive silicon. At moderately high temperatures, such as those required for the reflow of aluminum into the narrow hole, aluminum tends to diffuse into the silicon and to severely degrade its semiconductive characteristics. Accordingly, a diffusion barrier needs to be placed between the aluminum and the underlying silicon.
These problems are well known and have been addressed by Xu et al. in U.S. patent application, Ser. No. 08/628,835, filed Apr. 5, 1996, incorporated herein by reference in its entirety, which is a continuation in part of U.S. patent application, Ser. No. 08/511,825, filed Aug. 7, 1995.
As shown in the cross-sectional view of FIG. 1, a contact hole 10 having an aspect ratio defined by its depth 12 and its width 14 is etched through a dielectric layer 16 to an underlying substrate 18, which in the more difficult situation includes a surface layer of silicon. In the hole filling process, the contact hole 10 is conformally coated with a titanium (Ti) layer 20, a titanium nitride (TiN) layer 22, and a graded (TiN x ) layer 24, that is, the graded layer 24 begins at its bottom as TiN but its top portion is nearly pure Ti. These three layers form a tri-layer barrier 26, which provides both the conformality and the adhesion to the underlying layers, as well as sufficient wetting for the after deposited aluminum. The Ti layer 20, after siliciding at a sufficiently high annealing temperature, forms a good ohmic contact with the underlying silicon substrate 18. Thereafter, a metal layer 28 is sputter deposited into the hole 10 so as to fill it without voids. That is, the tri-layer barrier 26 sufficiently wets to the after filled aluminum that it readily flows into the hole 10 at a moderate temperature while the tri-layer barrier 26 nonetheless provide a sufficient diffusion barrier between the aluminum 28 and the underlying silicon 18.
According to Xu et al., the wetting quality of the three layers 20, 22, 24 is enhanced by depositing them in a high-density PVD reactor. On the other hand, they recommend that the aluminum layer 28 be sputter deposited in a conventional PVD chamber with a low plasma density. In particular, they recommend that the aluminum layer 28 be deposited as two layers in an improved two-step cold/warm version of a conventional sputtering process. In the first cold step, a seed layer 30 of aluminum is sputter deposited at a substrate temperature below 200° C. so as to conformally coat the underlying barrier tri-layer 26 with a fairly uniform aluminum layer. In the second, warm step, a filling layer 32 of aluminum is sputter deposited at higher temperatures so as to reflow and fill the contact hole 10. An advantage of the tri-layer barrier 26 grown by ionized metal plating (IMP) is that the warm Al filling layer 32 can be filled at temperatures below 400° C., even as low as 350° C. according to the reported data. The warm layer 32 can be deposited at a fairly high rate so as to improve the system throughput. Because the two aluminum layers 30, 32 differ primarily in their different deposition temperatures, they are likely deposited within a single conventional PVD chamber capable only of developing a low-density plasma. Also, the two deposition can be performed continuously, with the temperature being ramped up during the deposition. As a result, the two Al layers 30, 32 have no clear boundary between them.
In the context of contact hole filling, a high-density plasma is defined in one sense as one substantially filling the entire volume it is in and having an average ion density of greater than 10 11 cm -3 in the principal part of the plasma. The conventional plasma-enhanced PVD reactor produces a plasma of significantly lower ion density. Although high-density plasmas are available in a number of different types of reactors, they are preferably obtained in inductively coupled plasma reactor, such as the type shown in schematical cross section in FIG. 2. For reasons to be described shortly, this is referred to an ionized metal plasma or plating (IMP) reactor.
As shown in this figure, which is meant only to be schematical, a vacuum chamber 40 is defined principally by a chamber wall 42 and a target backing plate 44. A PVD target 46 is attached to the target backing plate 44 and has a composition comprising at least part of the material being sputter deposited. For the deposition of both titanium (Ti) and titanium nitride (TiN), the target 46 is made of titanium. A substrate 48 being sputter deposited with a layer of a PVD film is supported on a pedestal electrode 50 in opposition to the target 46. Processing gas is supplied to the chamber 40 from gas sources 52, 54 as metered by respective mass flow controllers 56, 58, and a vacuum pump system 60 maintains the chamber 40 at the desired low pressure.
An inductive coil 62 is wrapped around the space between the target 46 and the pedestal 50. Three independent power supplies are used in this type of inductively coupled sputtering chamber. A DC power supply 64 negatively biases the target 46 with respect to the pedestal 50. An RF power source 66 supplies electrical power in the megahertz range to the inductive coil 62. The DC voltage applied between the target 46 and the substrate 48 causes the processing gas supplied to the chamber to discharge and form a plasma. The RF coil power inductively coupled into the chamber 40 by the coil 62 increases the density of the plasma, that is, increases the density of ionized particles. Magnets 68 disposed behind the target 46 significantly increase the density of the plasma adjacent to the target 46 in order to increase the sputtering efficiency. Another RF power source 70 applies electrical power in the frequency range of 100 kHz to a few megahertz to the pedestal 50 in order to bias it with respect to the plasma.
Argon from the gas source 54 is the principal sputtering gas. It ionizes in the plasma, and its positively charged ions are attracted to the negatively biased target 46 with enough energy that the ions sputter particles from the target 46, that is, target atoms or multi-atom particles are dislodged from the target. The sputtered particles travel primarily along ballistic paths, and some of them strike the substrate 48 to deposit upon the substrate as a film of the target material. If the target 46 is titanium or a titanium alloy and assuming no further reactions, a titanium film is thus sputter deposited, or in the case of an aluminum target, an aluminum film is formed.
For the sputter deposition of TiN in a process called reactive sputtering, gaseous nitrogen is also supplied into the chamber 40 from the gas source 52 along with the argon. The nitrogen chemically reacts with the surface layer of titanium being deposited on the substrate to form titanium nitride.
As Xu et al. describe in the cited patent application, a high-density plasma, primarily caused by the high amount of coil power applied to the chamber 40, increases the fraction of the sputter species that become ionized as they traverse the plasma, hence the term ionized metal plating. The wafer bias power applied to the pedestal 50 causes the pedestal 50 to become DC biased with respect to the plasma, the voltage drop occurring in the plasma sheath adjacent to the substrate 48. Thus, the bias power provides a tool to control the energy and directionality of the sputter species striking the substrate 48.
Xu et al. disclose that the Ti/TiN/TiN x barrier tri-layer 26 should be deposited in an ionized metal plating (IMP) process in which the various power levels are set to produce a high-density plasma. They observe that an IMP barrier tri-layer 26 as shown in FIG. 1, when deposited in the contact hole 10, promotes the reflow of aluminum into the contact hole 10 when the aluminum is subsequently deposited in a conventional PVD reactor, that is, one not using inductively coupled RF power and not producing a high-density plasma. This superior reflow is believed to require two characteristics in a narrow aperture. The barrier layer needs to adhere well to the underlying SiO 2 or Si so as to form a continuous, very thin film. The aluminum needs to wet well to the barrier layer so that it flows over the barrier layer at relatively low temperatures.
Although the TiN IMP barrier tri-layer offers significant advantages in promoting reflow of subsequently deposited conventional PVD aluminum, as processing requirements become even more demanding, further improvement of reflow into narrow apertures is desired.
SUMMARY OF THE INVENTION
The invention can be summarized as a method of filling a narrow hole and the structure resultant therefrom in which the hole is first filled with a barrier layer comprising one or more layers of TiN or other refractory metal materials. Thereafter, a non-refractory metal, such as aluminum is coated into the hole with an ionized metal process (IMP), that is, in the presence of a high-density plasma. Thereafter, the remainder of the hole is filled with a standard PVD process involving a low-density plasma.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematical cross-sectional view of a known type of contact in an integrated circuit.
FIG. 2 is a schematical side illustration of a ionized metal process (IMP) reactor for physical vapor deposition (PVD).
FIG. 3 is a schematical cross-sectional view of a contact in an integrated circuit according to the invention.
FIG. 4 is a flow diagram of an aluminum hole filling process incorporating the invention.
FIG. 5 is a scanning electron micrograph (SEM) of a contact of the invention.
FIG. 6 is a SEM of a contact of the prior art showing the formation of voids.
FIG. 7 is a schematical plan view of an integrated processing tool incorporating various reaction chambers usable with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A contact formed according to the invention is illustrated in cross section in FIG. 3. The contact is formed in the contact hole 10 etched in the oxide layer 16 overlying the silicon surface of the substrate 18. Just as in Xu et al.'s structure illustrated in FIG. 1, an IMP barrier tri-layer 26 is deposited into the contact hole 10. The barrier tri-layer includes a Ti layer 20, a TiN layer 22, and a graded TiN x layer 24, all sputtered in a high-density plasma by an ionized metal plating (IMP) process.
According to the invention, an IMP aluminum layer 70 is sputter deposited over the barrier tri-layer 26 in an IMP process, that is, in a high-density plasma, for example as practiced in the reactor of FIG. 2. A standard aluminum layer 72 is sputter deposited over the IMP aluminum layer 70, preferably by a conventional PVD process utilizing a low-density plasma. The IMP aluminum layer 70 is easily conformally coated into the contact hole 10 and forms a seed layer for the after-deposited aluminum filler layer 72. Advantageously, the IMP aluminum layer 70 can be deposited at near to room temperature, and the aluminum filler layer 72 can effectively fill the contact hole 10 at relatively low deposition temperatures. That is, the total process has a low thermal budget. Nonetheless, the contact hole is effectively filled and planarized.
The complete processing sequence for a preferred processing embodiment of the invention is shown by the flow diagram of FIG. 4. In step 80, a contact hole is etched through the overlying oxide layer to the underlying substrate having at least a silicon surface in the vicinity of the contact hole. After some cleaning steps described in the example below, in step 82, an IMP PVD chamber sputter deposits a titanium layer into the hole. In step 84, the titanium layer is annealed so as be silicided to the underlying silicon. In step 86, an IMP PVD chamber reactively sputters a layer of TiN over the titanium layer in the contact hole by additionally admitting nitrogen into the reaction chamber. In step 88, the PVD chamber sputter deposits the graded TiN x layer onto the TiN layer. This is most typically accomplished by cutting off the supply of nitrogen from the previous step 86, and the residual nitrogen in the chamber or embedded in the Ti target is gradually depleted until a pure Ti layer is being deposited. In step 90, the wafer is transferred to another IMP PVD chamber in which a layer of aluminum is deposited by IMP. In step 92, the wafer is transferred to a standard PVD chamber, which deposits an aluminum filling layer in a standard warm process.
EXAMPLE
Contact holes were etched through a dielectric layer of SiO 2 having a thickness of 1.2 μm. The contact holes had diameters of 0.35 μm. Thus, the contact hole had an aspect ratio of 3.5:1. Prior to the PVD deposition, the etched wafer was subjected to one minute of PVD degassing and a pre-cleaning which removed an equivalent of 25 nm of oxide.
The wafer was then transferred into a first IMP chamber, such as that illustrated in FIG. 2, for deposition of the barrier tri-layer. The titanium target was DC biased at 6 kW, the coil was RF biased at 1.5 kW, and the pedestal during the titanium process was sufficiently RF biased to create about a -50 V DC bias with respect to the plasma. The tri-layer was then formed having a titanium thickness of 20 nm, a TiN thickness of 80 nm, and a TiN x thickness of about 10 nm resulting from a 5 sec titanium sputter after cutoff of the nitrogen.
The wafer was then transferred to another IMP chamber having an aluminum target. The biasing conditions were the same except that no bias was applied to the pedestal. (The presence of bias on the pedestal was demonstrated to have little effect.) Argon was maintained at a pressure of 30 mTorr in the chamber while 200 nm of aluminum was sputter deposited by the IMP process.
Thereafter, the wafer was transferred to a conventional PVD chamber where a layer of warm aluminum was deposited by traditional sputter deposition. The layer of warm aluminum had a thickness of 1.5 μm as measured on a planar surface, and it was deposited with the substrate held at a temperature of about 375° C.
The resulting structure was sectioned and examined with a scanning electron microscope (SEM). The micrograph is shown in FIG. 5. In all cases, the warm aluminum completely filled the contact holes with no voids. The vertical feature seen in the top center and the tent structure seen at the bottom of the contact holes are artifacts of the SEM.
COMPARATIVE EXAMPLE
A comparative test was performed with the general structure suggested by Xu et al. That is, the IMP aluminum layer of the invention was replaced by a warm standard PVD aluminum layer deposited at near to room temperature in a low-density plasma. Also, the pedestal was RF biased to create a DC self bias of -50 V.
The resulting micrograph is shown in FIG. 6. In all cases, significant voids have developed at the bottom of the contact holes, in one of the four contacts extending half way up the hole. The voids indicate that there was insufficient reflow with the warm aluminum. Such voids are unacceptable in a commercial process because of the high contact resistance they produce. These experimental results should not be interpreted to mean that the process of Xu et al. cannot be optimized for the structure and composition of the two examples, but the results do show that, for at least one combination, the IMP aluminum layer provides a better seed layer than the conventional PVD cold aluminum layer.
The invention is preferably practiced on an integrated multi-chamber tool, such as the Endura® 5500 platform illustrated in plan view in FIG. 7, which is functionally described by Tepman et al. in U.S. Pat. No. 5,186,718.
Wafers are loaded into the system by two independently operated loadlock chambers 100, 102 configured to transfer wafers into and out of the system from wafer cassettes loaded into the respective loadlock chambers. The pressure of a first wafer transfer chamber 104 to which the loadlocks can be selectively connected via unillustrated slit valves can be regulated between the atmospheric or somewhat lower pressure of the cassette to a moderately low pressure, for example, in the range of 10 -3 to 10 -4 Torr. After pumpdown of the first transfer chamber 104 and of the selected loadlock chamber 100, 102, a first robot 106 located in the first transfer chamber 104 transfers the wafer from the cassette to one of two wafer orienters 108, 110 and then to a degassing orienting chamber 112. The first robot 106 then passes the wafer into an intermediately placed plasma preclean chamber 114, from whence a second robot 116 transfers it to a second transfer chamber 118, which is kept at a significantly lower pressure, preferably below 10 -7 Torr and typical 2×10 -8 Torr. The second robot 116 selectively transfers wafers to and from reaction chambers arranged around its periphery.
A first IMP PVD chamber 120 is dedicated to the deposition of the Ti-based barrier tri-layer. A second IMP PVD chamber 122 is dedicated to the deposition of the IMP aluminum layer. Two standard PVD chambers 124, 126 are dedicated to the deposition of the warm aluminum in a low-density plasma. It may be desirable to modify this configuration to have two IMP PVD chambers for titanium deposition and only one standard PVD chamber for the warm aluminum. Each of the chambers 120, 122, 124, 126 is selectively opened to the second transfer chamber 118 by unillustrated slit valves.
After the low-pressure PVD processing, the second robot 116 transfers the wafer to an intermediately placed cool-down chamber 128, from whence the first robot 106 withdraws the wafer and transfers it to a standard PVD chamber 130. This chamber deposits on the wafer a TiN layer of controlled thickness and dielectric constant, which serves as an anti-reflection coating (ARC) over the metal layers just deposited in the PVD chambers positioned around the second transfer chamber 118. The ARC layer facilitates photolithography of the highly reflective metal layers. After ARC deposition, the wafer is transferred to a cassette in one of the two loadlocks 100, 102. Of course, other configurations of the platform are possible with which the invention can be practiced.
The entire system is controlled by a controller 132 operating over a control bus 134 to be in communication with sub-controllers 136, as illustrated in FIG. 2, associated with each of the chambers. Process recipes are read into the controller 132 by recordable media 137, such as magnetic floppy disks or CD-ROMs, insertable into the controller 132, or over a communication link 138.
Many variations of the invention are possible, some of which are presented below.
Hole filling may be applied to other applications than contact holes, for example, trenches, wall structures for dynamic memories, or inter-layer vias. If the underlying material is a metal, the barrier layer can be simplified, perhaps with the elimination of either one or both of the Ti layer and the graded TiN x layer.
It is possible to deposit both of the aluminum layers in a single PVD reactor with the power supplies being changed between the two depositions to emphasize respectively a directional and conformal IMP deposition and a fast standard PVD deposition. It is also possible to achieve the IMP high-density plasma by means other than inductive coupling, e.g, electron cyclotron resonance, helicon couplers, or remote microwave plasma sources.
It is possible to deposit the filling aluminum layer in an IMP process even though this will require more time.
Since in the preferred arrangement of FIG. 7 the aluminum deposition is performed in two separate chambers, the composition of the aluminum target and hence of the resultant film may be advantageously varied. That is, it is well known to alloy aluminum with various alloying elements such as silicon and copper, and these alloying percentages may vary between the targets of the two chambers to obtain particularly advantageous metal layers.
Although the invention has been described in regard to preferred metallization of aluminum, it may be applied as well to other metals such as copper applied over the barrier layers. Of course, the after-deposited layer should have a substantially non-refractive composition so as to differ from the underlying barrier tri-layer based on titanium or other similar refractory metals, such as tantalum, cobalt, tungsten, and nickel.
Although the tri-layer structure is preferred, especially for silicon contacts, in some situations such as vias to inter-layer metal layers, it may not be necessary to include the titanium siliciding layer or the TiNx graded layer. Barrier layers of other compounds of refractory metals may be used with the invention.
The invention thus provides a way to assure that narrow inter-level hole are effectively filled with aluminum or other metals. | A hole filling process for an integrated circuit in which wiring levels in the integrated circuit are connected by a narrow hole, especially where the underlying level is silicon. First, a physical vapor deposition (PVD) process fills a barrier tri-layer into the hole. The barrier tri-layer includes sequential layers of Ti, TiN, and graded TiN x , grown under conditions of a high-density plasma. Thereafter, a first aluminum layer is PVD deposited under conditions of a high-density plasma. A filling aluminum layer is then deposited by standard PVD techniques. | 2 |
[0001] The present application claims priority from U.S. Provisional Application Ser. No. 61/837,974, filed Jun. 21, 2013, which is incorporated by reference herein in its entirety.
FIELD OF INVENTION
[0002] The present invention relates to a fracturing fluid and optionally an associated proppant composition wherein fumed silica increases the viscosity of liquid carbon dioxide that is delivered into a well-bore for the fracture treatment of oil and gas reservoirs.
BACKGROUND OF THE INVENTION
[0003] The use of carbon dioxide for production of oil and gas from hydrocarbon containing reservoirs is well known. Utilization of liquid carbon dioxide (LCO 2 ) in fracture treatment of oil and gas formations has certain advantages in water sensitive and low pressure formations. First, the use of LCO 2 enables a significant reduction in water volume utilized, which minimizes formation damage caused by the water and second, it promotes water flow-back (i.e., retrieval of water introduced, or produced, in the fracture treatment) through expansion when pressure is let off the fractured formation. LCO 2 used in fracturing treatments is typically added to a high pressure stream of water and proppant (usually sand) at the well-head. This is due, in part, because it is simpler to add proppant to water at atmospheric pressure than it is to add proppant to LCO 2 at elevated pressure (i.e. greater than the triple point pressure of carbon dioxide, which is 75.1 psia).
[0004] Hydraulic fracturing is the term used to describe a process whereby a fluid is pumped into a well bore communicating with a subterranean reservoir under sufficient pressure to fracture the matrix of the subterranean geological formation. As these pressure forces increase, they commence and propagate fractures (fissures or cracks) in the reservoir matrix. The dimensions of the fractures generally increase by continuing to pump the pressurized fluid into the formation through the well bore.
[0005] An acceptable fracturing fluid must have several characteristics. Among these are the following: (1) the viscosity should be low enough to easily pump the fluid with conventional surface equipment; (2) the fluid must be viscous enough to move the proppant in suspension during the pumping operations and deposit the proppant in the fractures created in the formation; (3) the fluid must flow into the fractures created in the formation with a minimum of fluid loss to the pores within the matrix formation; and (4) the fluid must not plug the pores of the formation permanently, to ensure the production capacity of the formation for obtaining the desired oil and gas (hydrocarbons). It is generally the case that more viscous fracturing fluids will cause shorter but wider fractures. Often it is desirable to produce shorter fractures in order to keep the fractures within a desired zone of the formation, and wider fractures are of use in oil-producing formations to enable the oil to be produced and flow more readily. More viscous fracturing fluids are also known to reduce fluid loss/formation leak-off, which detracts from the efficiency of the fracturing operation.
[0006] Historically, the base fluid of many fracturing fluids (sometimes referred to as carrier fluid) has been comprised of either an aqueous fluid or a hydrocarbon fluid. Some of these base fluids can be utilized in conjunction with thickening agents (gels). Under some circumstances, for instance in slickwater fracturing—where a friction reducer allows pumping the fluid at high velocities—facilitating proppant transport, the addition of these thickening agents is not required. However, it is often the case that the base fracturing fluids are too low in viscosity to adequately maintain the proppant in suspension at normal pumping rates, therefore the addition of a thickening agent is desired.
[0007] It is normal to use a fracturing fluid without proppant to cause the initial fracture, in a pad stage, and it is possible to eliminate use of a proppant, for instance in shallow formations where fractures can remain open by themselves after fracture treatment. Normally, however, proppant is added to prop the fractures open and facilitate oil and gas recovery from the well. In addition to keeping the propping material or proppant in suspension while being pumped down the well, the fracturing fluid must also properly deposit the proppant in the fractures of the formation. In general, the higher the viscosity of the fracturing fluid, the more suitable the fluid is for purposes of proppant suspension. The higher viscosity fracturing fluids tend to hold the proppant in suspension as the fracturing fluid is pumped into the well and prevents the proppant from settling into the bottom portion of the resulting fracture. Moreover, the higher viscosity fracturing fluids tend to prevent the proppant from bridging across the fracture. If bridging of the proppant can be avoided, or the proppant does not settle at the bottom of the fracture, a longer propped fracture is obtainable and a better hydrocarbon recovery will result.
[0008] U.S. Pat. No. 4,567,947 to Canadian Fracmaster Ltd., discloses a fracturing fluid composition including at least one substantially anhydrous aliphatic alcohol, a non-ionic homopolymer to form a gel with the alcohol and as gel activating agent an alkali metal halide or an alkaline earth metal halide. Similarly, U.S. Pat. No. 4,701,270 to Canadian Fracmaster Ltd., discloses a fracturing fluid including liquid carbon dioxide which has been thickened by the addition of a small amount of a copolymer which is the reaction product of liquid carbon dioxide and an alkene oxide, preferably propylene oxide. These chemically based gel thickeners relied upon the need to be soluble in the carbon dioxide, whereas the fumed silica of the present invention do not have this constraint.
[0009] Great Britain Patent Number 1439735 to Texaco is directed to a hydraulic fracturing method for subterranean formations and describes a method for increasing the productivity of the formation by using a fracturing fluid wherein the fracturing fluid is a thickened composition containing fumed silica. The method is directed to water and hydrocarbons, and not liquefied gases, and through the inclusion of strongly polar fluids, such as water, is in direct contrast with the findings of the present invention, as this disclosure is directed to the use of non-polar liquefied gases such as LCO 2 .
[0010] Furthermore, the aforementioned documents do not address the need for thickening LCO 2 required to ensure optimal fracing with or without a proppant. By adding the fumed silica to the LCO 2 with or without additional additives depending on the demands presented by the geological formations, lack of viscosity from chemical thickeners such as gels has been addressed by the present invention physical thickeners.
SUMMARY OF THE INVENTION
[0011] The present invention provides a fluid composition for increasing the recovery of hydrocarbons from a geological formation, wherein the fluid composition includes: a non-polar fluid that is liquid carbon dioxide (LCO 2 ) and a fumed silica thickener, wherein the thickener increases the viscosity of the fluid composition to a range of between about 0.5 to 500 centipoise.
[0012] The invention also includes providing a method of fracturing, wherein the fluid is pumped down a well bore and into a subterranean formation (e.g., containing oil, gas, hydrocarbons, etc.) at a pressure that will fracture the subterranean formation. It is one object of the present invention to provide a fracturing fluid which will have sufficient viscosity to operate effectively. More specifically, the present invention provides a composition as well as a method for providing the fluid composition which increases the productivity of hydrocarbon extraction from a geological formation penetrated by a well. The composition includes a fracturing fluid that is liquid carbon dioxide (LCO 2 ), and a fumed silica which increases the viscosity of the composition. This thickener enhances the fracturing of the formation and placement of proppant depending on the geological formation and the composition of the strata that is being extracted.
[0013] It is also an object of the present invention to produce a fluid composition that behaves as a shear thinning or thixotropic fluid with a viscosity that will decrease with increasing shear rates. This will cause the apparent viscosity to drop in the vicinity of the well bore where shear stresses are high, and thereby minimize frictional losses. This will cause the apparent viscosity to increase in the fracture where shear stresses are lower, so that proppant can be delivered throughout the fracture.
[0014] It is yet another object of this invention to produce a fluid which is not permanently degraded by the extremely high rates of shear, pressures, and temperatures encountered during the hydraulic fracturing processes. The fracturing fluid may also include a hydrocarbon, a surfactant, a polymer (e.g., gelling agent, friction reducer, etc.) and/or minor polar compound, or a mixture of these components, normally in the absence of any water or moisture. The fluid also contains a thickening or viscosity increasing agent comprising fumed silica with a surface area of from 50 to 400 m 2 /g and an average primary particle size from 7 to 40 nanometers. The goal is to use the fumed silica to increase the viscosity by at least five fold using approximately 1,000-10,000 ppm of the fumed silica (up to 1 percent by weight is likely) and thereby minimize the cost associated with fracturing operations utilizing the fumed silica. The fracturing fluid is substantially devoid of any water or moisture, as it “contaminates” the fluid composition. The possibility of water and moisture addition, however, exists in most cases such as in this embodiment, but it is undesirable.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 illustrates graphically the percent fumed silica concentration at various proppant bed heights.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Fumed silica is an amorphous material, which is made up roughly spherical primary particles sintered together into chain-like aggregates. These aggregates are branched and have an external surface area of from around 50 to 400 m 2 /gram—which provides a very useful and plentiful surface area to volume ratio. This allows drastic chemio-physical property changes using low weight or volume percentages of the fumed silica. The relatively low percentages of fumed silica required properly increase the viscosity of liquefied gases, and in particular liquefied carbon dioxide (LCO 2 ). This in turn keeps the costs of these additives to a minimum. In addition, each segment in the chains has many hydroxyl (OH) groups attached to silicon atoms at the surface. When the segments come in proximity with each other, the hydroxyl groups will bond to each other forming a three dimensional network of agglomerated aggregates. It is this network that imparts viscosity to the base fluid, and for it to form sufficiently, the fumed silica aggregates must first be well dispersed in the base fluid through the action of high shear, and then be allowed to agglomerate via hydrogen bonds. The fumed silica may be uncoated, or not surface treated, in which case the aggregated particles are highly hydrophilic and will tend to bond with themselves when in a non-aqueous or low polarity base fluid. For the purposes of this invention, the fumed silica is usually not surface treated, although there may be instances where surface treated silica (with, for example, silane surface treatment) may further improve the fracing fluid properties. Various coatings or after treatments such as polydimethylsiloxane (PDMS), dimethyldichlorosilane (DDS) and hexamethyldisilazane (HMDS), can be added to affect and tune the rheology of fumed silica in various base fluids, including CO 2 .
[0017] Fumed silicas are readily available from several manufacturers. One source is the Cabot Corporation of Boston, Mass. under the trade name CAB-O-SIL®, as well as additional manufacturers including Evonik under the trade name AEROSIL® and Wacker under the trade name HDK® Pyrogenic Silica. Fumed silica is also available from other commercial sources and the reference to these sources is not intended to limit the scope of this invention.
[0018] When silica particles are dispersed in a liquid medium, the network structure formed by the silica particles restricts movement of molecules in the liquid medium creating internal friction. This results in an increase in the apparent viscosity of the liquid. The thickening efficiency of the fumed silica is directly related to the polarity of the liquid to be thickened. The use of selected additives (surfactants and/or multifunctional compounds) can tailor the thickening efficiency of the fumed silica in some fluids. The interface between the silica and the solvent increases the degree to which the silica particles form the three dimensional network and can allow significantly less silica to be used to achieve equivalent thickening of the base fluid than would be the case for other potential fluid thickening agents. For example, less than 1% of the fumed silica, based on the weight of the total liquid to be thickened, will achieve marked increases in viscosity. This is somewhat in line with conventional gels employed in water and hydrocarbon based fluids, which may be added at percent levels to increase viscosity of a base fluid to around 100 cP for example, and sometimes cross- linked to increase viscosity further to several 100 cP for example. However, there are no known conventional gels that will thicken LCO 2 to this extent.
[0019] In some situations, it is possible that there may be up to 3 percent by weight of water in the fracturing fluid or liquid medium composition. Added water will not greatly affect the viscosity of the fluid, will not normally mix well with the LCO 2 and can interact with uncoated fumed silica (which is extremely hydrophilic). Water is polar and LCO 2 is non-polar, therefore, it is important to not add more polar additives, such as polar surfactants, polar friction reducers, or other polar thickening agents to the fracturing fluid when using the uncoated fumed silica. Polar substances can greatly reduce or eliminate the viscosity increasing or thickening effect of the uncoated fumed silica in the non-polar LCO 2 .
[0020] When hydrocarbons are also used in the fracturing fluid composition of the present invention, it may be any liquid hydrocarbon commonly found in and about an oil/gas producing well or contemplated geological formation and the hydrocarbon is preferably non-polar or substantially non-polar. Examples of suitable hydrocarbons are aromatics, such as toluene, and aliphatics, such as liquefied petroleum (LPG), propane, butane, pentane, hexane. Naphtha, kerosene and crude oil may be used as well as essentially any other mixture of suitable and available hydrocarbons.
[0021] Slickwater fracturing fluids are aqueous fluids that employ a friction reducer, but that often do not employ a viscosity enhancing agent and are well known in the industry. Many of the friction reducers used in slickwater fracture stimulation are high molecular weight polyacrylamides introduced in water and mineral oil emulsions. The concentrations of friction reducers typically employed in slickwater fracturing fluids, typically range from about 0.5 gallons per thousand (gpt) to 2 gpt, and it is believed that the mineral oil and polyacrylamide in the emulsions can cause polymer cake residues that can damage the formations. As with conventional thickening gels, “breakers” are sometimes introduced into the slick water fracturing fluids to reduce the size of the polymer chains after fracture treatment, and thereby potentially reduce fracture-face and formation damage caused by these polymer residues.
[0022] Fracture of the formation utilizes refrigerated LCO 2 that is provided from bulk storage vessels to the inlets of one or more high pressure fracture pumps, where the pressure is raised from approximately 200 to 300 psig to the required surface treating pressure. The surface treating pressure is normally in the range 1,000 to 10,000 psig. Thereafter, the CO 2 is sent through the well bore to fracture or treat the formation. When proppant is required, it will be metered into the low pressure LCO 2 stream to the required concentration, which can be in the range of about 0.25 to 10 pounds per gallon of CO 2 , prior to the high pressure fracture pumps. In the present invention, fumed silica can be added to the LCO 2 stream at any point in this process, and with or without the presence of proppant or other desired chemicals. The fumed silica, however, must be metered into the LCO 2 stream to achieve the correct concentration and must be dispersed by high shear, in order for it to be effective for the purposes of the invention. In this case, the fumed silica is added to LCO 2 at 0.1 to 5 weight percent, more preferably 0.25 to 3 weight percent and most preferably 0.5 to 1.5 weight percent.
[0023] It is most convenient to add the fumed silica to the LCO 2 in the lower pressure stream fed to the fracture pumps, and prior to the point where proppant will be added. In this manner, the equipment for metering the fumed silica into the LCO 2 while imparting initial dispersion can operate at a low pressure, and the fumed silica can travel further with the LCO 2 prior to entering the well bore. Using this technique allows for longer and better dispersion by utilizing the shear imparted by the high velocities due to the mechanical action of the proppant particles and high pressure fracture pump. The equipment for metering and initially dispersing the fumed silica is not intended to limit the scope of this invention, but can include a pressure vessel for receiving and pressurizing the fumed silica in the presence of the LCO 2 , a metering means such as an auger, or eductor for regulating the flow of fumed silica into the LCO 2 , and preferably a means for imparting initial shear to the fumed silica and LCO 2 mixture. Shear can be obtained by forcing the mixture (LCO 2 , and fumed silica) to pass through a high speed rotating blade and stator arrangement, for example.
[0024] Alternative means to add the fumed silica to the LCO 2 include loading pre-dispersed fumed silica into one or more LCO 2 storage tanks; and co-addition of the fumed silica to the LCO 2 with the proppant stream.
[0025] The present invention will further be illustrated below by referring to the following examples and comparative example, which are, however, not to be construed as limiting the invention.
EXAMPLE
[0026] This example illustrates the effect of an uncoated fumed silica having a mean primary particle size of approximately 10 nm and surface area of approximately 200 m 2 /g when added to toluene at various concentrations in the range of 0.5 to 3.3 weight percent of the silica in toluene. Four samples were prepared. In each case, approximately 270 g of total fluid mixture was prepared by placing pure toluene in ajar that was 95 mm wide to a depth of approximately 50 mm, and then adding the corresponding amount of uncoated fumed silica (i.e., 0.5, 1.25, 1.5, and 3.3 weight percent) to the toluene with continuous mild stirring of the fluid mixture. A Caframo model BDC6015 stirrer unit was employed with a 48 mm diameter dispersion blade, rotating at a 200 rpm. Once all of the fumed silica had been added, the stirring speed was increased to 4,000 rpm and the speed was held for 15 minutes in order to completely disperse the fumed silica in the toluene. After 15 minutes, the mixture was weighed and a requisite amount of toluene added to replace that lost to evaporation during the mixing process, thereby ensuring the proper concentration of fumed silica (i.e., 0.5, 1.25, 1.5, and 3.3 weight percent) was maintained. Each mixture prepared appeared to be slightly opaque and thicker in consistency than pure toluene.
[0027] Thereafter, small vials were prepared for each fumed silica/toluene sample and combined with a commercial proppant. Vials (12 ml.volume) were used having an internal diameter and height of approximately 16 mm and 50 mm, respectively. To each vial was added 3.2 grams of a Saint Gobain Interprop −30 mesh +50 mesh proppant and 9 ml of the fumed silica/toluene sample. According to the manufacturer, this proppant had a mean particle diameter of 0.485 mm and specific gravity of 3.2, and it was dark in color, providing good visual contrast. This combination provided an equivalent concentration ratio of proppant to fluid of 3 lbs. of proppant per gallon of fluid, which is a common proppant loading used during the course of a commercial fracture treatment.
Comparative Example
[0028] In addition, a similar sample was prepared in accordance to the procedure outlined above, but only using pure toluene and the same proppant as a baseline. In other words, no fumed silica was utilized.
Testing Results
[0029] Each sample was then shaken and set to rest for 15 minutes. During shaking it was visibly observed that proppant in all the samples containing fumed silica took longer to settle than the sample containing no fumed silica. This effect was shown to increase with increasing fumed silica concentration. This finding qualitatively confirmed that the fumed silica added viscosity to the toluene, and that the viscosity increased with fumed silica concentration. The height of the settled proppant bed was measured in each sample after 15 minutes and the results are shown in FIG. 1 where one benefit of the use of fumed silica in a fluid containing proppant is illustrated. As it is illustrated the fumed silica caused the settled bed to be expanded in comparison with the case where no fumed silica was present. This effect was most pronounced for the 3.3 percent fumed silica mixture resulting in an expanded bed height of 34 mm as compared to the baseline of 8 mm proppant bed. This difference represents a 3.3 fold increase. This settled bed expansion effect was noted in all samples containing fumed silica and increased approximately linearly with concentration in the range tested. This surprising effect remained intact after 48 hrs, and was still present more than a month after measurement. The effect can be attributed to establishing a network of fumed silica aggregates acting to support the proppant particles and thus preventing them from settling into a compact bed.
[0030] In these tests, uncoated fumed silica was dispersed in toluene, which is a mildly polar solvent that compares favorably with liquid CO 2 (LCO 2 ) - which is non-polar. It is, therefore, expected that the same or very similar effects will be achieved when uncoated fumed silica is dispersed in LCO 2 , and that the effect can be modified through the use of fumed silica concentration and the use of surface coatings of the silica, as required for each application. The settled bed expansion effect is expected to be particularly useful during deposition of proppant in the fractures of a formation by LCO 2 , where it is expected that the fracture will fill more completely with proppant than if no fumed silica were present. Furthermore, the retarded settling of the proppant observed during shaking is anticipated to aid the carrying of the proppant particles through various pipes, manifold equipment, and the well bore during pumping of the LCO 2 , thus alleviating proppant settling.
[0031] While the invention has been described in detail with reference to specific embodiments thereof, it will become apparent to one skilled in the art that various changes and modifications can be made, and equivalents employed, without departing from the scope of the appended claims. | A composition and method required for providing a fracturing fluid pumped down a well bore and into a subterranean formation under conditions of pressure that will fracture the subterranean formation is described. More specifically, the composition increases the recovery of hydrocarbons from a geological formation penetrated by a well bore, wherein the composition includes a fracturing fluid that is liquid carbon dioxide (LCO 2 ) with proppant to aid transport of the proppant in suspension, and thereby create a fracture using a fracturing fluid which is the thickened composition containing fumed silica. When the composition is without a proppant, the viscosity of the composition is increased in order to improve the fracturing operation through aspects such as increased fracture width and reduced fluid leak-off | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 11/487,481 filed 17 Jul. 2006 now U.S. Pat. No. 7,375,902, which is a division of application Ser. No. 11/218,591 filed 6 Sep. 2005 now U.S. Pat. No. 7,145,730, which is a division of application Ser. No. 10/867,819 filed 16 Jun. 2004 now U.S. Pat. No. 6,975,462, which is a division of application Ser. No. 10/409,172 filed Apr. 9, 2003 now U.S. Pat. No. 6,771,432, the contents of which are incorporated herein by reference.
This application claims priority under 35 USC §119 of Japanese Application No. 2002-106378 filed in Japan on Apr. 9, 2002, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to a zoom lens and an electronic imaging system using the same, and more particularly to an electronic imaging system such as a video camera or a digital camera, the depth dimension of which is diminished by providing some contrivances to an optical system portion such as a zoom lens.
In recent years, digital cameras (electronic cameras) have received attention as the coming generation of cameras, an alternative to silver-halide 35 mm-film (usually called Leica format) cameras. Currently available digital cameras are broken down into some categories in a wide range from the high-end type for commercial use to the portable low-end type.
In view of the category of the portable low-end type in particular, the primary object of the present invention is to provide the technology for implementing video or digital cameras whose depth dimension is reduced while high image quality is ensured, and which are easy to handle.
The gravest bottleneck in diminishing the depth dimension of cameras is the thickness of an optical system, especially a zoom lens system from the surface located nearest to its object side to an image pickup plane.
Recent technologies for slimming down cameras rely primarily on a collapsible lens mount that allows the optical system to be taken out of a camera body for phototaking and received therein for carrying. Typical examples of an optical system that can effectively be slimmed down while relying on the collapsible lens mount are disclosed in JP-A's 11-194274, 11-287953 and 2000-9997. Each publication discloses an optical system comprising, in order from its object side, a first lens group having negative refracting power and a second lens group having positive refracting power, wherein both lens groups move during zooming.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided a zoom lens, comprising, in order from its object side, a first lens group that remains fixed during zooming, a second lens group that has negative refracting power and moves during zooming, a third lens group that has positive refracting power and moves during zooming, and a fourth lens group that has positive refracting power and moves during zooming and focusing, characterized in that the first lens group comprises, in order from its object side, a negative meniscus lens component convex on its object side, a reflecting optical element for bending an optical path and a positive lens.
According to another aspect of the present invention, there is provided a zoom lens, comprising, in order from its object side, a first lens group that remains fixed during zooming, a second lens group that has negative refracting power and moves during zooming, a third lens group that has positive refracting power and moves during zooming, and a fourth lens group that has positive refracting power and moves during zooming and focusing, characterized in that the first lens group comprises a reflecting optical element for bending an optical path, and upon focusing on an infinite object point, the fourth lens group moves in a locus opposite to that of movement of the third lens group during zooming.
The advantages of, and the requirements, for the above arrangements used herein are now explained.
While relying upon the arrangement comprising, in order from its object side, the first lens group that remains fixed during zooming, the second lens group that has negative refracting power and moves during zooming, the third lens group that has positive refracting power and moves during zooming and the fourth lens group that has positive refracting power and moves during both zooming and focusing, the zoom lens of the present invention enables an associated camera to be immediately put into the ready state unlike a collapsible lens mount camera. To be favorable for water-proofing and dust-proofing purposes, the first lens group is designed to remain during zooming, and for considerably reducing the depth dimension of the camera, at least one reflecting optical element for bending an optical path is located in the first lens group nearest to the object side of the lens system.
However, the location of the optical path-bending reflecting optical element in the first lens group would give rise to the following two demerits.
A. The depth of an entrance pupil increases, leading unavoidably to an increase in the size of each lens element forming the first lens group that, by definition, has a large diameter.
B. The magnification of a combined system comprising the second or the third lens group that, by definition, has a zooming function and the subsequent lens group or groups is close to zero, and so the zoom ratio becomes low relative to the amount of zooming movement.
First of all, the condition necessary for bending is explained. Referring to a zoom type such as one intended herein, the location of the optical path-bending reflecting optical element in the first lens group necessarily makes the position of the entrance pupil likely to become deep, as in the case of JP-A 10-62687 or 11-258507, resulting in an increase in the size of each optical element that forms the first lens group. It is thus preferable that the first lens group comprises, in order from its object side, a negative meniscus lens component convex on its object side, a reflecting optical element for bending an optical path and a positive lens and satisfies the following conditions (1), (2), (3) and (4).
1.4 <−f 11 /√( f W ·f T )<2.4 (1)
1.2 <f 12 /√( f W ·f T )<2.2 (2)
0.8 <d/L< 2.0 (3)
1.55<n PRI (4)
Here f 11 is the focal length of the negative meniscus lens component in the first lens group, f 12 is the focal length of the positive lens element in the first lens group, f W and f T are the focal lengths of the zoom lens at the wide-angle end and the telephoto end of the zoom lens, respectively, d is an air-based length from the image side-surface of the negative meniscus lens component to the object side-surface of the positive lens element in the first lens group, as measured on the optical axis of the zoom lens, L is the diagonal length of the (substantially rectangular) effective image pickup area of an electronic image pickup device, and n PRI is the d-line refractive index of the medium of a prism used as the optical path-bending reflecting optical element in the first lens group.
In order to locate the entrance pupil at a shallow position thereby enabling the optical path to be physically bent, it is preferable to increase the powers of the lens elements on both sides of the first lens group, as defined by conditions (1) and (2). As the upper limits of 2.4 and 2.2 to both conditions are exceeded, the entrance pupil remains at a deep position. Hence, when it is intended to ensure some angle of view, the diameter or size of each optical element forming the first lens group becomes too large to physically bend the optical path. As the lower limits of 1.4 and 1.2 are not reached, the magnification that the lens groups subsequent to the first lens group and designed to move for zooming can have becomes close to zero, offering problems such as an increase in the amount of zooming movement or a zoom ratio drop and, at the same time, rendering correction of off-axis aberrations such as distortion and chromatic aberrations difficult.
Condition (3) is provided to determine the length necessary for the location of the optical path-bending reflecting optical element, as measured along the optical axis of the zoom lens. Although the value of this condition should preferably be as small as possible, it is understood that as the lower limit of 0.8 thereto is not reached, a light beam contributing to the formation of an image at the periphery of a screen does not satisfactorily arrive at the image plane or ghosts are likely to occur. As the upper limit of 2.0 is exceeded, it is physically difficult to bend the optical path as in the case of conditions (1) and (2).
As can be understood from the foregoing, the air-based length, d, as defined by condition (3) should preferably be cut down by using as the optical path-bending element in the first lens group a prism in which entrance and exit surfaces are formed of planar surfaces or different in curvature from the lens surfaces on both sides of the first lens group and making the refractive index of a prism medium as high as possible. As the lower limit of 1.55 to condition (4) is not reached, it is physically difficult to bend the optical path. It is also preferable that n PRI does not exceed 1.90. Exceeding 1.90 means that the prism costs much, and renders ghosts likely to occur.
More preferably, at least one or all of the following conditions (1)′, (2)′, (3)′ and (4)′ should be satisfied.
1.5 <−f 11 /√( f W ·f T )<2.2 (1)′
1.3 <f 12 /√( f W ·f T )<2.0 (2)′
0.9 <d/L< 1.7 (3)′
1.65<n PRI (4)′
Even more preferably, at least one of the following conditions (1)″, (2)″, (3)″ and (4)″ should be satisfied.
1.6 <−f 11 /√( f W ·f T )<2.0 (1)″
1.4 <f 12 /√( f W ·f T )<1.8 (2)″
1.0 <d/L< 1.5 (3)″
1.75<n PRI (4)″
Most preferably, all conditions (1)″ to (4)″ should be satisfied.
Further, the zoom lens of the present invention should preferably satisfy the following condition (a).
1.8 <f T /f W (a)
Here f W is the focal length of the zoom lens at the wide-angle end, and f T is the focal length of the zoom lens at the telephoto end.
Falling short of the lower limit of 1.8 to this condition means that the zoom ratio of the zoom lens becomes lower than 1.8. More preferably in this case, the value of f T /f W should not exceed 5.5. At greater than 5.5, the zoom ratio becomes high and the amount of the lens groups that move during zooming becomes too large. This causes the zoom lens to become large in the optical path-bending direction, and so renders it impossible to set up any compact imaging system.
Next, how to ensure any desired zoom ratio is explained. When the first lens group of the present invention has positive refracting power, the position of a principal point is evidently located nearer to the image side of the zoom lens as compared with the case where there is no optical path-bending reflecting optical element. This means that with the same refracting power, the position of an image point by the first lens group is located nearer to the image side; that is, an object point with respect to the second lens group is located at a farther position. Consequently, the magnification of the second lens group approaches zero, and the change in the focal length of the zoom lens becomes small even upon movement of the second lens group. One approach to solving this problem is to make the focal length of the first lens group short (so that the focal length of the zoom lens becomes short), whereby the focal length of the second lens group is increased to a certain degree to increase the magnification of the second lens group. According to the present invention wherein a combined system comprising the third lens group and the subsequent lens group (or groups) is also allowed to have a zooming function, if the magnifications, zoom ratios, etc. of both are artfully set, it is then possible to provide an efficient zooming of the zoom lens. Specific conditions to this end are determined by the following conditions (5), (6) and (7).
0.4<−β 2w <1.2 (5)
0.1<−β RW <0.5 (6)
0<log γ R /log γ 2 <1.3 (7)
Here β 2W is the magnification of the second lens group at the wide-angle end of the zoom lens upon focused on an infinite object point, β RW is the composite magnification of a combined system comprising the third lens group and all subsequent lens groups at the wide-angle end upon focused on an infinite object point, γ 2 is β 2T /β 2W provided that β 2T is the magnification of the second lens group at the telephoto end of the zoom lens upon focused on an infinite object point, and γ R is β RT /β RW provided that β RT is the composite magnification of a combined system comprising the third lens group and all subsequent lens groups at the telephoto end upon focused on an infinite object point.
As the lower limits of 0.4 and 0.1 to conditions (5) and (6) are not reached, any satisfactorily high zoom ratio cannot be obtained throughout the zoom lens or the moving space becomes too large, resulting in a size increase. This in turn renders correction of various aberrations difficult, partly because the focal length of the first lens group becomes too short, and partly because the Petzval sum becomes large. Exceeding the upper limit of 1.3 to condition (7) is not preferable because fluctuations of the F-number and exit pupil position with zooming become too large. As the lower limit of 0 is not reached, the entrance pupil becomes too deep and the bending of the optical path becomes physically difficult. In any case, any satisfactorily high zoom ratio cannot be obtained throughout the zoom lens, or the moving space becomes too large, leading to a bulky size.
More preferably, at least one or all of the following conditions (5)′, (6)′ and (7)′ should be satisfied.
0.4<−β 2W <1.1 (5)′
0.20<−β RW <0.45 (6)′
0.15<log γ R /log γ 2 <1.2 (7)′
Even more preferably, at least one of the following conditions (5)″, (6)″ and (7)″ should be satisfied.
0.6<−β 2W <1.0 (5)″
0.25<−β RW <0.4 (6)″
0.25<log γ R /log γ 2 <1.0 (7)″
In order to satisfy conditions (5), (6) and (7), the following conditions (8) and (9), too, should preferably be satisfied.
1.6 <f 1 /√( f W ·f T )<6.0 (8)
1.1 <−f 2 /√( f W ·f T )<2.2 (9)
Here f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, and f W and f T are the focal lengths of the zoom lens at the wide-angle and the telephoto end, respectively.
As the upper limit to condition (8) is exceeded, any satisfactorily high magnification cannot be obtained throughout the zoom lens or the moving space becomes too large, leading to a bulky size. As the lower limit is not reached, correction of off-axis aberrations and chromatic aberrations becomes difficult.
As the upper limit of 2.2 to condition (9) is exceeded, zooming efficiency becomes high thanks to an increase in the magnification of the second lens group; however, the efficiency may rather decrease because the amount of movement to obtain the same zoom ratio is proportional to the focal length. As the lower limit of 1.1 is not reached, the magnification of the second lens group comes close to zero, ending up with a zooming efficiency drop.
More preferably, the following conditions (8)′ and/or (9)′ should be satisfied.
1.9 <f 1 /√( f W ·f T )<4.5 (8)′
1.2 <−f 2 /√( f W ·f T )<2.0 (9)′
Even more preferably, the following conditions (8)″ and/or (9)″ should be satisfied.
2.2 <f 1 /√( f W ·f T )<3.0 (8)″
1.3 <−f 2 /√( f W ·f T )<1.8 (9)″
Most preferably, both conditions (8)″ and (9)″ should be satisfied.
As the second lens group is designed with a high magnification, another problem arises. The magnification of the second lens group becoming high means that an object point with respect to a combined system that comprises the third lens group and the subsequent lens group or groups and has another zooming function is located at a farther position and the magnification of the combined system comes close to zero, resulting in a drop of zooming efficiency by that combined system. There are two approaches to solving this problem; one is to make the focal length of the combined system comprising the third lens group and the subsequent lens group or groups long to a certain degree, and another is to bring a principal point as close to an image point for the second lens group as possible. In the former case, the following condition (10) should preferably be satisfied.
0.8 <f RW /√( f W ·f T )<1.7 (10)
Here f RW is the composite focal length of the combined system comprising the third lens group and the subsequent lens group or groups, and f W and f T are the focal lengths of the zoom lens at the wide-angle and the telephoto end, respectively.
As the lower limit of 0.8 to condition (10) is not reached, the zooming efficiency by the combined system comprising the third lens group and the subsequent lens group or groups becomes worse. As the upper limit of 1.7 is exceeded, the zooming efficiency becomes worse for the same reason as in condition (9). In the latter case, the third lens group should preferably have therein at least one converging surface that is defined by an air contact surface convex on its object side and satisfies the following condition (b) and at least one diverging surface that is located on an image side with respect to the converging surface, is defined by an air contact surface convex on its image side and satisfies the following condition (b).
0 <R P /f W <2 (b)
0 <R N /f W <4 (c)
Here R P and R N are the axial radii of curvature of the converging surface and the diverging surface, respectively. Otherwise, it is difficult to bring the principal point for the third lens group close to the image point for the second lens group.
More preferably, the following condition (10)′ should be satisfied.
0.9 <f RW /√( f W ·f T )<1.5 (10)′
Most preferably, the following condition (10)″ should be satisfied.
1.0 <f RW /√( f W ·f T )<1.3 (10)″
Particularly preferably for both the cases, the focal length of the combined system comprising the third lens group and the subsequent lens group or groups should be increased upon zooming from the wide-angle end to the telephoto end, as defined by the following condition (11).
1.0 <f RT /f RW <2.5 (11)
Here f RW is the composite focal length of the combined system comprising the third lens group and all the subsequent lens groups at the wide-angle end, and f RT is the composite focal length of the combined system comprising the third lens group and all the subsequent lens groups at the telephoto end.
As the lower limit of 1.0 to condition (11) is not reached, the effect of the combined system comprising the third and subsequent lens groups on zooming becomes slender, the amount of movement of the second lens group increases and the entrance pupil becomes deep, and it is difficult to bend the optical path. As the upper limit of 2.5 is exceeded, fluctuations of F-number with zooming tend to become noticeable.
More preferably, the following condition (11)′ should be satisfied.
1.1 <f RT /f RW <2.3 (11)′
Most preferably, the following condition (11)″ should be satisfied.
1.2 <f RT /f RW <2.1 (11)″
According to the method most effective for the achievement of condition (11), the third lens group that, by definition, must be located as close to the image plane as possible at the wide-angle end with a view to obtaining high zoom ratios and the lens group located nearest to the object side of the zoom lens in the subsequent lens groups (hereinafter called the fourth lens group) should rather be located as near to the object side as possible, so that upon zooming to the telephoto side, the third lens group is moved toward the object side while the fourth lens group is moved toward the image side of the zoom lens (upon focusing on an infinite object point).
Specific conditions to this end are to satisfy the following conditions (12) and (13).
0.20 <−M 3 /M 2 <1.50 (12)
0.15 <−M 4 /M 3 <1.00 (13)
where M 2 is the amount of movement of the second lens group from the wide-angle end to the telephoto end, M 3 is the amount of movement of the third lens group from the wide-angle end to the telephoto end, and M 4 is the amount of movement of the fourth lens group from the wide-angle end to the telephoto end, provided that the movement of each lens group toward the image side is of positive sign.
Exceeding the upper limit of 1.50 to condition (12) is not preferable because fluctuations of F-number and an exit pupil position with zooming become too noticeable. As the lower limit of 0.20 is not reached, the entrance pupil becomes too deep and so it is physically hard to bend the optical path. In any case, any satisfactorily high zoom ratio cannot be obtained throughout the zoom lens or the moving space becomes too large, leading to a bulky size.
As the upper limit of 1.00 to condition (13) is exceeded, the magnification of the combined system comprising the third and subsequent lens groups may become high. Since a main moving lens group is the fourth lens group for focusing, however, this is not preferable because fluctuations of magnification with focusing tend to become noticeable. As the lower limit of 0.15 is not reached, the principal point for the combined system comprising the third and subsequent lens groups is far away from the image point for the second lens group. This in turn causes a drop of zooming efficiency, or renders the focal length of the combined system comprising the third and subsequent lens group or groups likely to become long or the lens arrangement of the third and subsequent lens group or groups unreasonable, offering an obstacle to correction of aberrations.
More preferably, the following conditions (12)′ and/or (13)′ should be satisfied.
0.30 <−M 3 /M 2 <1.40 (12)′
0.20 <−M 4 /M 3 <0.80 (13)′
Even move preferably, the following condition (12)″ or (13)″ should be satisfied.
0.40 <−M 3 /M 2 <1.30 (12)″
0.25 <−M 4 /M 3 <0.60 (13)″
Most preferably, both conditions (12)″ and (13)″ should be satisfied.
It is noted that focusing should preferably be performed with the fourth lens group. It is then preferable to satisfy the following condition (14).
0.10 <D 34W /f W <0.70 (14)
Here D 34W is an air separation between the third lens group and the fourth lens group at the wide-angle end upon focused on an infinite object point, and f W is the focal length of the zoom lens at the wide-angle end.
As the lower limit of 0.10 to this condition is not reached, the third lens group is prone to interference with the fourth lens group for lack of any focusing space. As the upper limit of 0.70 is exceeded, conversely, the moving space for zooming tends to become insufficient.
More Preferably,
0.15 <D 34W /f W <0.60 (14)′
Most preferably,
0.20 <D 34W /f W <0.50 (14)″
When focusing is performed by movement of the fourth lens group, on the other hand, astigmatism tends generally to be placed in an ill-balanced state. This astigmatism is likely to occur especially when residual astigmatism occurring at the 1st to 3rd lens groups is corrected at the fourth lens group. Thus, both refracting surfaces of any one of the lens components forming the third lens group, inclusive of the doublet component, should be configured as aspheric surfaces. It is also preferable to incorporate at least one doublet component of a positive and a negative lens element in the third lens group because chromatic aberrations should preferably be corrected at the third lens group that has generally high light rays. It is understood that the “lens component” used herein means a lens that contacts spaces on both sides alone and has any air contact surface nowhere on the optical path, e.g., a single lens or a doublet.
The construction of the third lens group is now explained in detail.
The third lens group may be made up of, in order from its object side:
1) a doublet component consisting of a positive lens element and a negative lens element and a single lens element configured as spherical surfaces at both surfaces, two subgroups or three lens elements in all,
2) a doublet component consisting of a single lens element configured as aspheric surfaces at both surfaces and a doublet component consisting of a positive lens element and a negative lens element, two subgroups or three lens elements in all, or
3) only a doublet component consisting of a positive lens element configured as aspheric surfaces at both air contact surfaces and a negative lens element, one group or two lens elements in all.
In any case, the doublet component may serve to slack the relative decentration sensitivity between the lens elements that form the third lens group.
Corresponding to the types 1), 2) and 3) of the third lens group, it is further preferable to satisfy the following conditions (15-1), (15-2) and (15-3), respectively (with respect to correction of aberrations and slacking of decentration sensitivity).
1.05 <R C3 /R C1 <3.00 (15-1)
0.25 <R C3 /R C1 <0.75 (15-2)
1.20 <R C3 /R C1 <3.60 (15-3)
Here R C1 is the axial radius of curvature of the surface nearest to the object side of the doublet component, and R C3 is the axial radius of curvature of the surface nearest to the image side of the doublet component.
Exceeding the respective upper limits of 3.00, 0.75 and 3.60 to these conditions (15-1), (15-2) and (15-3) may be favorable for correction of spherical aberrations, coma and astigmatism throughout the zoom lens; however, the effect of cementing on slacking of decentration sensitivity becomes slender. As the respective lower limits of 1.05, 0.25 and 1.20 are not reached, correction of spherical aberrations, coma and astigmatism throughout the zoom lens becomes difficult.
More Preferably,
1.15 <R C3 /R C1 <2.50 (15-1)′
0.30 <R C3 /R C1 <0.65 (15-2)′
1.40 <R C3 /R C1 <3.00 (15-3)′
Most preferably,
1.25 <R C3 /R C1 <2.00 (15-1)″
0.35 <R C3 /R C1 <0.55 (15-2)″
1.60 <R C3 /R C1 <2.40 (15-3)″
Furthermore corresponding to the types 1), 2) and 3) of the third lens group, it is preferable to satisfy the following conditions (16-1) and (17-1), (16-2) and (17-2), and (16-3) and (17-3) with respect to correction of chromatic aberrations.
−0.7 <L/R C2 <0.1 (16-1)
10<ν CP −ν CN (17-1)
−0.5 <L/R C2 <0.3 (16-2)
20<ν CP −ν CN (17-2)
−0.9 <L/R C2 <−0.1 (16-3)
10<ν CP −ν CN (17-3)
Here L is the diagonal length in mm of an effective image pickup area of the electronic image pickup device, R C2 is the axial radius of curvature of a cementing surface of the doublet component in the third lens group, ν CP is the d-line based Abbe number of a medium of the positive lens element of the doublet component in the third lens group, and ν CN is the d-line based Abbe number of a medium of the negative lens element of the doublet component in the third lens group with the proviso that the electronic image pickup device is used in such a way as to include an angle of view of 55° or greater at the wide-angle end.
Falling short of the respective lower limits of −0.7, −0.5 and −0.9 to conditions (16-1), (16-2) and (16-3) may be favorable for correction of longitudinal chromatic aberration and chromatic aberration of magnification; however, this is not preferable because chromatic aberration of spherical aberration is likely to occur, and spherical aberrations at short wavelengths remain over-corrected even when spherical aberrations at the reference wavelength can be well corrected, causing chromatic blurring of images. As the respective upper limits of 0.1, 0.3 and −0.1 are exceeded, correction of longitudinal chromatic aberration and chromatic aberration of magnification tends to become insufficient and spherical aberrations at short wavelengths are prone to under-correction.
As the respective lower limits of 10, 20 and 10 to conditions (17-1), (17-2) and (17-3) are not reached, correction of longitudinal chromatic aberration tends to become insufficient. The upper limits to conditions (17-1), (17-2) and (17-3) may prima facie be set at 90. Any combinations of media exceeding the upper limit of 90 do not occur in nature. A preferable upper limit to ν CP −ν CN is 60. Materials of greater than 60 are expensive.
More preferably, either one or both of the following conditions (16-1)′ and (17-1)′, (16-2)′ and (17-2)′, and (16-3)′ and (17-3)′ should be satisfied.
−0.6 <L/R C2 <0.0 (16-1)′
15<ν CP −ν CN (17-1)′
−0.4 <L/R C2 <0.2 (16-2)′
25<ν CP −ν CN (17-2)′
−0.8 <L/R C2 <−0.2 (16-3)′
15<ν CP −ν CN (17-3)′
Even more preferably, either one of the following conditions (16-1)″ and (17-1)″, (16-2)″ and (17-2)″, and (16-3)″ and (17-3)″ should be satisfied.
−0.5 <L/R C2 <−0.1 (16-1)″
20<ν CP −ν CN (17-1)″
−0.3 <L/R C2 <0.1 (16-2)″
30<ν CP −ν CN (17-2)″
−0.7 <L/R C2 <−0.3 (17-2)″
−0.7 L/R C2 <−0.3 (16-3)″
20<ν CP −ν CN (17-3)″
Most preferably, both of the above conditions (16-1)″ and (17-1)″, (16-2)″ and (17-2)″, and (16-3)″ and (17-3)″ should be satisfied.
The fourth lens group should preferably be composed of one positive lens component and satisfy the following conditions (18) and (19).
−4.00<( R 4F +R 4R )/( R 4F −R 4R )<0.0 (18)
0.10 <L/f 4 <0.70 (19)
Here R 4F is the axial radius of curvature of the object side-surface of the positive lens component, R 4R is the axial radius of curvature of the image side-surface of the positive lens component, L is the diagonal length of an effective image pickup area of the electronic image pickup device, and f 4 is the focal length of the fourth lens group.
Exceeding the upper limit of 0.0 to condition (18) is not preferable for zooming efficiency because a principal point for the combined system comprising the third and subsequent lens groups tends to be far away from the image point by the second lens group. As the lower limit of −4.00 is not reached, fluctuations of astigmatism with focusing tend to become large.
As the upper limit of 0.70 to condition (19) is exceeded, the third and fourth lens groups cannot move in opposite directions during zooming. Falling short of the lower limit of 0.10 is not preferable because the amount of movement of the fourth lens group for focusing becomes too large.
More preferably, either one or both of the following conditions (18)′ and (19)′ should be satisfied.
−3.60<( R 4F +R 4R )/( R 4F −R 4R )<−0.40 (18)′
0.15 <L/f 4 <0.60 (19)′
Even more preferably, either one of the following conditions (18)″ and (19)″ should be satisfied.
−3.20<( R 4F +R 4R )/( R 4F −R 4R )<−0.80 (18)″
0.20 <L/f 4 <0.50 (19)″
Most preferably, both of the above conditions (18)″ and (19)″ should be satisfied.
For the second lens group having a long focal length, it should be only composed of, in order from its object side, a negative lens element and a positive lens element, two lens elements in all. In conjunction with the first lens group, it is preferable to satisfy the following conditions (20) and (21).
−0.80<( R 1PF +R 1PR )/( R 1PF −R 1PR )<0.90 (20)
−0.10<( R 2NF +R 2NR )/( R 2NF −R 2NR )<2.00 (21)
Here R 1PF is the axial radius of curvature of the object side-surface of the positive lens component in the first lens group, R 1PR is the axial radius of curvature of the image side-surface of the positive component in the first lens group, R 2NF is the axial radius of curvature of the object side-surface of the negative lens component in the second lens group, and R 2NR is the axial radius of curvature of the image side-surface of the negative lens component in the second lens group.
As the upper limit of 0.90 to condition (20) is exceeded, higher-order chromatic aberrations of magnification tend to occur, and as the lower limit of −0.80 is not reached, the entrance pupil tends to become deep.
As the upper limit of 2.00 to condition (20) is exceeded, coma tends to occur, and as the lower limit of −0.10 is not reached, barrel distortion tends to occur.
More preferably, either one or both of the following conditions (20)′ and (21)′ should be satisfied.
−0.50<( R 1PF +R 1PR )/( R 1PF −R 1PR )<0.70 (20)′
−0.20<( R 2NF +R 2NR )/( R 2NF −R 2NR )<1.50 (21)′
Even more preferably, either one of the following conditions (20)″ and (21)″ should be satisfied.
−0.20<( R 1PF +R 1PR )/( R 1PF −R 1PR )<0.50 (20)″
0.50<( R 2NF +R 2NR )/( R 2NF −R 2NR )<1.00 (21)″
Most preferably, both of the above conditions (20)″ and (21)″ should be satisfied.
The presumption for the electronic image pickup device used herein is that it has a total angle of view of 55° or greater at the wide-angle end. The 55 degrees are the wide-angle-end total angle of view needed commonly for electronic image pickup devices.
For the electronic image pickup device, the wide-angle-end total angle of view should preferably be 80° or smaller. At greater than 80°, distortions are likely to occur, and it is difficult to make the first lens group compact. It is thus difficult to slim down the electronic imaging system.
Thus, the present invention provides means for reducing the thickness of the zoom lens portion while satisfactory image-formation capability is maintained.
Next, how and why the thickness of filters is reduced is now explained. In an electronic imaging system, an infrared absorption filter having a certain thickness is usually inserted between an image pickup device and the object side of a zoom lens, so that the incidence of infrared light on the image pickup plane is prevented. Here consider the case where this filter is replaced by a coating devoid of thickness. In addition to the fact that the system becomes thin as a matter of course, there are spillover effects. When a near-infrared sharp cut coat having a transmittance (τ 600 ) of at least 80% at 600 nm and a transmittance (τ 700 ) of up to 8% at 700 nm is introduced between the image pickup device in the rear of the zoom lens system and the object side of the system, the transmittance at a near-infrared area of 700 nm or longer is relatively lower and the transmittance on the red side is relatively higher as compared with those of the absorption type, so that the tendency of bluish purple to turn into magenta—a defect of a CCD or other solid-state image pickup device having a complementary colors filter—is diminished by gain control and there can be obtained color reproduction comparable to that by a CCD or other solid-state image pickup device having a primary colors filter. In addition, it is possible to improve on color reproduction of, to say nothing of primary colors and complementary colors, objects having strong reflectivity in the near-infrared range, like plants or the human skin.
Thus, it is preferable to satisfy the following conditions (22) and (23):
τ 600 /τ 550 ≧0.8 (22)
τ 700 /σ 550 ≦0.8 (23)
where τ 550 is the transmittance at 550 nm wavelength.
More preferably, the following conditions (22)′ and/or (23)′ should be satisfied:
τ 600 /τ 550 ≧0.85 (22)′
τ 700 /τ 550 ≦0.05 (23)′
Even more preferably, the following conditions (22)″ or (23)″ should be satisfied:
τ 600 /τ 550 ≧0.9 (22)″
τ 700 /τ 550 ≦0.03 (23)″
Most preferably, both conditions (28)″ and (29)″ should be satisfied.
Another defect of the CCD or other solid-state image pickup device is that the sensitivity to the wavelength of 550 nm in the near ultraviolet range is considerably higher than that of the human eye. This, too, makes noticeable chromatic blurring at the edges of an image due to chromatic aberrations in the near-ultraviolet range. Such color blurring is fatal to a compact optical system. Accordingly, if an absorber or reflector is inserted on the optical path, which is designed such that the ratio of the transmittance (τ 400 ) at 400 nm wavelength to that (τ 550 ) at 550 nm wavelength is less than 0.08 and the ratio of the transmittance (τ 440 ) at 440 nm wavelength to that (τ 550 ) at 550 nm wavelength is greater than 0.4, it is then possible to considerably reduce noises such as chromatic blurring while the wavelength range necessary for color reproduction (satisfactory color reproduction) is kept intact.
It is thus preferable to satisfy the following conditions (24) and (25):
τ 400 /τ 550 ≦0.08 (24)
τ 440 /τ 550 ≧0.4 (25)
More preferably, the following conditions (24)′ and/or (25)′ should be satisfied.
τ 400 /τ 550 ≦0.06 (24)′
τ 440 /τ 550 ≧0.5 (25)′
Even more preferably, the following condition (24)″ or (25)″ should be satisfied.
τ 400 /τ 550 ≦0.04 (24)″
τ 440 /τ 550 ≧0.6 (25)″
Most preferably, both condition (24)″ and (25)″ should be satisfied.
It is noted that these filters should preferably be located between the image-formation optical system and the image pickup device.
On the other hand, a complementary colors filter is higher in substantial sensitivity and more favorable in resolution than a primary colors filter-inserted CCD due to its high transmitted light energy, and provides a great merit when used in combination with a small-size CCD.
To shorten and slim down the optical system, the optical low-pass filter that is another filter, too, should preferably be thinned as much as possible. In general, an optical low-pass filter harnesses a double-refraction action that a uniaxial crystal like berg crystal has. However, when the optical low-pass filter includes a quartz optical low-pass filter or filters in which the angles of the crystal axes with respect to the optical axis of the zoom lens are in the range of 35° to 55° and the crystal axes are in varying directions upon projected onto the image plane, the filter having the largest thickness along the optical axis of the zoom lens among them should preferably satisfy the following condition (26) with respect to its thickness t LPF (mm).
0.08 <t LPF /a< 0.16(at a< 4 μm)
0.075 <t LPF /a< 0.15(at a< 3 μm) (26)
Here t LPF (mm) is the thickness of the optical low-pass filter having the largest thickness along the optical axis of the zoom lens with the angle of one crystal axis with respect to the optical axis being in the range of 35° to 55°, and a is the horizontal pixel pitch (in μm) of the image pickup device.
Referring to a certain optical low-pass filter or an optical low-pass filter having the largest thickness among optical low-pass filters, its thickness is set in such a way that contrast becomes theoretically zero at the Nyquist threshold wavelength, i.e., at approximately a/5.88 (mm). A thicker optical low-pass filter may be effective for prevention of swindle signals such as moiré fringes, but makes it impossible to take full advantages of the resolving power that the electronic image pickup device has, while a thinner filter renders full removal of swindle signals like moiré fringes impossible. However, swindle signals like moiré fringes have close correlations with the image-formation capability of a taking lens like a zoom lens; high image-formation capability renders swindle signals like moiré fringes likely to occur. Accordingly, when the image-formation capability is high, the optical low-pass filter should preferably be somewhat thicker whereas when it is low, the optical low-pass filter should preferably be somewhat thinner.
As the pixel pitch becomes small, on the other hand, the contrast of frequency components greater than the Nyquist threshold decreases due to the influence of diffraction by the image-formation lens system and, hence, swindle signals like moiré fringes are reduced. Thus, it is preferable to reduce the thickness of the optical low-pass filter by a few % or a few tens % from a/5.88 (mm) because a rather improved contrast is obtainable at a spatial frequency lower than the frequency corresponding to the Nyquist threshold.
More Preferably,
0.075 <t LPF /a< 0.15(at a< 4 μm)
0.07 <t LPF /a< 0.14(at a< 3 μm) (26)′
Most preferably,
0.07 <t LPF /a< 0.14(at a< 4 μm)
0.065 <t LPF /a< 0.13(at a< 3 μm) (26)″
If an optical low-pass filter is too thin at a<4 μm, it is then difficult to process. Thus, it is permissible to impart some thickness to the optical low-pass filter or make high the spatial frequency (cutoff frequency) where contrast reduces down to zero even when the upper limit to conditions (26), (26)′ and (26)″ is exceeded. In other words, it is permissible to regulate the angle of the crystal axis of the optical low-pass filter with respect to the optical axis of the zoom lens to within the range of 15° to 35° or 55° to 75°. In some cases, it is also permissible to dispense with the optical low-pass filter. In that angle range, the quantity of separation of incident light to an ordinary ray and an extraordinary ray is smaller than that around 45°, and that separation does not occur at 0° or 90° (at 90°, however, there is a phase difference because of a velocity difference between both rays—the quarter-wave principle).
As already described, when the pixel pitch becomes small, it is difficult to increase the F-number because the image-formation capability deteriorates under the influence of diffraction at a high spatial frequency that compensates for such a small pixel pitch. It is thus acceptable to use two types of aperture stops for a camera, i.e., a full-aperture stop where there is a considerable deterioration due to geometric aberrations and an aperture stop having an F-number in the vicinity of diffraction limited. It is then acceptable to dispense with such an optical low-pass filter as described before.
Especially when the pixel pitch is small and the highest image-formation capability is obtained at a full-aperture stop, etc., it is acceptable to use an aperture stop having a constantly fixed inside diameter as means for controlling the size of an incident light beam on the image pickup plane instead of using an aperture stop having a variable inside diameter or a replaceable aperture stop. Preferably in that case, at least one of lens surfaces adjacent to the aperture stop should be set such that its convex surface is directed to the aperture stop and it extends through the inside diameter portion of the aperture stop, because there is no need of providing any additional space for the stop, contributing to length reductions of the zoom optical system. It is also desirable to locate an optical element having a transmittance of up to 90% (where possible, the entrance and exit surfaces of the optical element should be defined by planar surfaces) in a space including the optical axis at least one lens away from the aperture stop or use means for replacing that optical element by another element having a different transmittance.
Alternatively, the electronic imaging system is designed in such a way as to have a plurality of apertures each of fixed aperture size, one of which can be inserted into any one of optical paths between the lens surface located nearest to the image side of the first lens group and the lens surface located nearest to the object side of the third lens group and can be replaced with another as well, so that illuminance on the image plane can be adjusted. Then, media whose transmittances with respect to 550 nm are different but less than 80% are filled in some of the plurality of apertures for light quantity control. Alternatively, when control is carried out in such a way as to provide a light quantity corresponding to such an F-number as given by a (μm)/F-number<4.0, it is preferable to fill the apertures with medium whose transmittance with respect to 550 nm are different but less than 80%. In the range of the full-aperture value to values deviating from the aforesaid condition as an example, any medium is not used or dummy media having a transmittance of at least 91% with respect to 550 nm are used. In the range of the aforesaid condition, it is preferable to control the quantity of light with an ND filter or the like, rather than to decrease the diameter of the aperture stop to such an extent that the influence of diffraction appears.
Alternatively, it is acceptable to uniformly reduce the diameters of a plurality of apertures inversely with the F-numbers, so that optical low-pass filters having different frequency characteristics can be inserted in place of ND filters. As degradation by diffraction becomes worse with stop-down, it is desirable that the smaller the aperture diameter, the higher the frequency characteristics the optical low-pass filters have.
It is understood that when the relation of the full-aperture F-number at the wide-angle end to the pixel pitch a (μm) used satisfies F>a, it is acceptable to dispense with the optical low-pass filter. In other words, it is permissible that the all the medium on the optical axis between the zoom lens system and the electronic image pickup device is composed of air or a non-crystalline medium alone. This is because there are little frequency components capable of producing distortions upon bending due to a deterioration in the image-formation capability by reason of diffraction and geometric aberrations.
It is noted that satisfactory zoom lenses or electronic imaging systems may be set up by suitable combinations of the above conditions and the arrangements of the zoom lens and the electronic imaging system using the same.
It is understood that only the upper limit or only the lower limit may be applied to each of the above conditions, and that the values of these conditions in each of the following examples may be extended as far as the upper or lower limits thereof.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts that will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1( a ), 1 ( b ) and 1 ( c ) are illustrative in section of Example 1 of the zoom lens according to the present invention at the wide-angle end. ( a ), in an intermediate state ( b ) and at the telephoto end ( c ), respectively, when the zoom lens is focused on an object point at infinity.
FIGS. 2( a ), 2 ( b ) and 2 ( c ) are illustrative in section of Example 2 of the zoom lens, similar to FIGS. 1( a ) to 1 ( c ).
FIGS. 3( a ), 3 ( b ) and 3 ( c ) are sections in schematic illustrative of Example 3 of the zoom lens, similar to FIGS. 1( a ) to 1 ( c ).
FIGS. 4( a ), 4 ( b ) and 4 ( c ) are illustrative in section of Example 4 of the zoom lens, similar to FIGS. 1( a ) to 1 ( c ).
FIGS. 5( a ), 5 ( b ) and 5 ( c ) are illustrative in section of Example 5 of the zoom lens, similar to FIGS. 1( a ) to 1 ( c ).
FIG. 6 is an optical path diagram for Example 1 of the zoom lens when the optical path is bent upon focused on an infinite object point at the wide-angle end.
FIG. 7 is illustrative of the diagonal length of the effective image pickup plane of an electronic image pickup device upon phototaking.
FIG. 8 is a diagram indicative of the transmittance characteristics of one example of the near-infrared sharp cut coat.
FIG. 9 is a diagram indicative of the transmittance characteristics of one example of the color filter located on the exit surface side of the low-pass filter.
FIG. 10 is a schematic illustrative of how the color filter elements are arranged in the complementary colors mosaic filter.
FIG. 11 is a diagram indicative of one example of the wavelength characteristics of the complementary colors mosaic filter.
FIG. 12 is a perspective view of details of one example of an aperture stop portion used in each example.
FIGS. 13( a ) and 13 ( b ) are illustrative in detail of another example of the aperture stop portion used in each example.
FIG. 14 is a front perspective schematic illustrative of the outside shape of a digital camera in which the optical path-bending zoom optical system of the present invention is built.
FIG. 15 is a rear perspective schematic of the digital camera of FIG. 14 .
FIG. 16 is a sectional schematic of the digital camera of FIG. 14 .
FIG. 17 is a front perspective view of an uncovered personal computer in which the optical path-bending zoom optical system of the present invention is built as an objective optical system.
FIG. 18 is a sectional view of a phototaking optical system for a personal computer.
FIG. 19 is a side view of the state of FIG. 17 .
FIGS. 20( a ) and 20 ( b ) are a front and a side view of a cellular phone in which the optical path-bending zoom optical system of the present invention is built as an objective optical system, and FIG. 20( c ) is a sectional view of a phototaking optical system for the same.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Examples 1 to 5 of the zoom lens according to the present invention are now explained. Sectional lens configurations of Examples 1 to 5 at the wide-angle end (a), in the intermediate state (b) and at the telephoto end (c) upon focused on an object point at infinity are shown in FIGS. 1 to 5 . Throughout FIGS. 1 to 5 , the first lens group is indicated by G 1 , the second lens group by G 2 , a stop by S, the third lens group by G 3 , the fourth lens group by G 4 , an optical low-pass filter by LF, a cover glass for an electronic image pickup device CCD by CG, and the image plane of CCD by I. A plane-parallel plate or the taken-apart optical path-bending prism in the first lens group G 1 is indicated by P. The maximum thickness of the optical low-pass filter LF used in these examples will be explained later. It is noted that instead of the near-infrared sharp cut coat, it is acceptable to use an optical low-pass filter LF coated directly with a near-infrared sharp cut coat, an infrared cut absorption filter or a transparent plane plate with a near-infrared sharp cut coat applied on its entrance surface.
As shown typically in FIG. 6 that is an optical path diagram for Example 1 of the zoom lens upon focused on an infinite object point at the wide-angle end, the optical path-bending prism P is configured as a reflecting prism for bending the optical path through 90°.
Example 1
As shown in FIGS. 1( a ), 1 ( b ) and 1 ( c ), Example 1 is directed to a zoom lens made up of a first lens group G 1 composed of a negative meniscus lens element convex on its object side, an optical path-bending prism P and a double-convex positive lens element, a second lens group G 2 composed of a double-concave negative lens element and a positive meniscus lens element convex on its object side, an aperture stop S, a third lens group G 3 composed of a doublet consisting of a double-convex positive lens element and a double-concave lens element and a fourth lens group G 4 composed of one positive meniscus lens element convex on its object side. Upon the wide-angle end to the telephoto end of the zoom lens, the first lens group G 1 and the aperture stop S remain fixed, the second lens group G 2 moves toward the image plane side of the zoom lens, the third lens group G 3 moves toward the object side of the zoom lens, and the fourth lens group G 4 moves toward the image plane side. For focusing on a nearby subject, the fourth lens group G 4 moves toward the object side.
Five aspheric surfaces are used; two at both surfaces of the double-concave negative lens element in the second lens group G 2 , two at the surfaces nearest to the object and image plane sides of the third lens group G 3 and one at the object side-surface of the positive meniscus lens element in the fourth lens group G 4 .
Example 2
As shown in FIGS. 2( a ), 2 ( b ) and 2 ( c ), Example 2 is directed to a zoom lens made up of a first lens group G 1 composed of a negative meniscus lens element convex on its object side, an optical path-bending prism P and a double-convex positive lens element, a second lens group G 2 composed of a double-concave negative lens element and a positive meniscus lens element convex on its object side, an aperture stop S, a third lens group G 3 composed of a doublet consisting of a double-convex positive lens element and a double-concave negative lens element and a fourth lens group G 4 composed of one positive meniscus lens element convex on its object side. Upon the wide-angle end to the telephoto end of the zoom lens, the first lens group G 1 and the aperture stop S remain fixed, the second lens group G 2 moves toward the image plane side of the zoom lens, the third lens group G 3 moves toward the object side of the zoom lens, and the fourth lens group G 4 moves toward the image plane side. For focusing on a nearby subject, the fourth lens group G 4 moves toward the object side.
Four aspheric surfaces are used; one at the image plane side-surface of the double-concave negative lens element in the second lens group G 2 , two at both surfaces of the double-convex positive lens element on the object side of the third lens group G 3 and one at the object side-surface of the positive meniscus lens element in the fourth lens group G 4 .
Example 3
As shown in FIGS. 3( a ), 3 ( b ) and 3 ( c ), Example 3 is directed to a zoom lens made up of a first lens group G 1 composed of a negative meniscus lens element on its object side, an optical path-bending prism P and a double-convex positive lens element, a second lens group G 2 composed of a double-concave negative lens element and a positive meniscus lens element convex on its object side, an aperture stop S, a third lens group G 3 composed of a double-convex positive lens element and a doublet consisting of a double-convex positive lens element and a double-concave negative lens element, and a fourth lens group G 4 composed of one positive meniscus lens element convex on its object side. Upon the wide-angle end to the telephoto end of the zoom lens, the first lens group G 1 and the aperture stop S remain fixed, the second lens group G 2 moves toward the image plane side of the zoom lens, the third lens group G 3 moves toward the object side of the zoom lens, and the fourth lens group G 4 moves toward the image plane side. For focusing on a nearby subject, the fourth lens group G 4 moves toward the object side.
Four aspheric surfaces are used; on at the image plane side-surface of the double-concave negative lens element in the second lens group G 2 , two at both surfaces of the double-convex positive lens element on the object side of the third lens group G 3 and one at the object side-surface of the positive meniscus lens element in the fourth lens group G 4 .
Example 4
As shown in FIGS. 4( a ), 4 ( b ) and 4 ( c ), Example 4 is directed to a zoom lens made up of a first lens group G 1 composed of a negative meniscus lens element convex on its object side, an optical path-bending prism P and a double-convex positive lens element, a second lens group G 2 composed of a double-concave negative lens element and a double-convex positive lens element, an aperture stop S, a third lens group G 3 composed of a doublet consisting of a double-convex positive lens element and a double-concave negative lens element and a meniscus lens element convex on its object side and a fourth lens group G 4 composed of one positive meniscus lens element convex on its object side. Upon the wide-angle end to the telephoto end of the zoom lens, the first lens group G 1 and the aperture stop S remain fixed, the second lens group G 2 moves toward the image plane side of the zoom lens, the third lens group G 3 moves toward the object side of the zoom lens, and the fourth lens group G 4 moves slightly toward the object side and then toward the image plane side. For focusing on a nearby subject, the fourth lens group G 4 moves toward the object side.
Five aspheric surfaces are used; two at both surfaces of the double-concave negative lens element in the second lens group G 2 , one at the object side-surface of the doublet in the third lens group G 3 and two at both surface of the meniscus lens element in the third lens group G 3 .
Example 5
As shown in FIGS. 5( a ), 5 ( b ) and 5 ( c ), Example 5 is directed to a zoom lens made up of a first lens group G 1 composed of a negative meniscus lens element convex on its object side, an optical path-bending prism P and a double-convex positive lens element, a second lens group G 2 composed of a doublet consisting of a double-concave negative lens element and a negative meniscus lens element convex on its object side, an aperture stop S, a third lens group G 3 composed of a double-convex positive lens element and a doublet consisting of a positive meniscus lens element convex on its object side and a negative meniscus lens element convex on its object side and a fourth lens group G 4 composed of one positive meniscus lens element convex on its object side. Upon the wide-angle end to the telephoto end of the zoom lens, the first lens group G 1 and the aperture stop S remain fixed, the second lens group G 2 moves toward the image plane side of the zoom lens, the third lens group G 3 moves toward the object side of the zoom lens, and the fourth lens group G 4 moves toward the image plane side. For focusing on a nearby subject, the fourth lens group G 4 moves toward the object side.
Four aspheric surfaces are used; one at the image plane side-surface of the negative meniscus lens element in the first lens group G 1 , two at both surfaces of the double-convex positive lens element in the third lens group G 3 and one at the object side-surface of the positive meniscus lens element in the fourth lens group G 4 .
The numerical data on each example are given below. Symbols used hereinafter but not hereinbefore have the following meanings:
f: focal length of the zoom lens F NO : F-number ω: half angle of view WE: wide-angle end ST: intermediate state TE: telephoto end r 1 , r 2 , . . . : radius of curvature of each lens surface d 1 , d 2 , . . . : spacing between the adjacent lens surfaces n d1 , n d2 , . . . : d-line refractive index of each lens element ν d1 , ν d2 , . . . : Abbe number of each lens element
Here let x be an optical axis on condition that the direction of propagation of light is positive and y be a direction perpendicular to the optical axis. Then, aspheric configuration is given by
x =( y 2 /r )/[1+{1−( K+ 1)( y/r ) 2 } 1/2 ]+A 4 y 4 +A 6 y 6 +A 8 y 8 +A 10 y 10
where r is a paraxial radius of curvature, K is a conical coefficient, and A 4 , A 6 , A 8 and A 10 are the fourth, sixth, eighth and tenth aspheric coefficients, respectively.
Example 1
r 1 = 31.0100
d 1 = 1.0000
n d1 = 1.80100
ν d1 = 34.97
r 2 = 9.9641
d 2 = 2.9000
r 3 = ∞
d 3 = 12.0000
n d2 = 1.80610
ν d2 = 40.92
r 4 = ∞
d 4 = 0.3000
r 5 = 23.6950
d 5 = 3.5400
n d3 = 1.74100
ν d3 = 52.64
r 6 = −23.6475
d 6 = (Variable)
r 7 = −377.9014
d 7 = 0.8000
n d4 = 1.80610
ν d4 = 40.92
(Aspheric)
r 8 = 6.4536
d 8 = 0.7000
(Aspheric)
r 9 = 6.8913
d 9 = 2.2000
n d5 = 1.75520
ν d5 = 27.51
r 10 = 16.1043
d 10 = (Variable)
r 11 = ∞ (Stop)
d 11 = (Variable)
r 12 = 7.5543
d 12 = 6.1695
n d6 = 1.74320
ν d6 = 49.34
(Aspheric)
r 13 = −13.0000
d 13 = 1.0000
n d7 = 1.84666
ν d7 = 23.78
r 14 = 13.1848
d 14 = (Variable)
(Aspheric)
r 15 = 12.3030
d 15 = 1.8000
n d8 = 1.74320
ν d8 = 49.34
(Aspheric)
r 16 = 1061.3553
d 16 = (Variable)
r 17 = ∞
d 17 = 1.9000
n d9 = 1.54771
ν d9 = 62.84
r 18 = ∞
d 18 = 0.8000
r 19 = ∞
d 19 = 0.7500
n d10 = 1.51633
ν d10 = 64.14
r 20 = ∞
d 20 = 1.3565
r 21 =
∞ (Image Plane)
Aspherical Coefficients
7th surface
K = 0
A 4 = 5.2999 × 10 −4
A 6 = −2.1607 × 10 −5
A 8 = 1.8300 × 10 −7
A 10 = 0.0000
8th surface
K = 0
A 4 = 5.8050 × 10 −4
A 6 = −1.0603 × 10 −5
A 8 = −7.5526 × 10 −7
A 10 = 0.0000
12th surface
K = 0
A 4 = 5.1734 × 10 −5
A 6 = 1.0455 × 10 −6
A 8 = −3.4185 × 10 −8
A 10 = 0.0000
14th surface
K = 0
A 4 = 8.4429 × 10 −4
A 6 = 2.1473 × 10 −5
A 8 = 7.3738 × 10 −7
A 10 = 0.0000
15th surface
K = 0
A 4 = −6.2738 × 10 −5
A 6 = 7.6642 × 10 −6
A 8 = −2.0106 × 10 −7
A 10 = 0.0000
Zooming Data (∞)
WE
ST
TE
f (mm)
6.01125
10.40282
17.99133
F NO
2.5820
3.5145
4.7679
ω (°)
32.7
19.6
11.4
d 6
0.78801
4.80346
8.70695
d 10
9.39271
5.38074
1.47422
d 11
11.13320
5.78312
1.48451
d 14
2.19671
8.56256
14.78227
d 16
4.12457
3.11055
1.18821
Example 2
r 1 = 31.1674
d 1 = 1.0000
n d1 = 1.80518
ν d1 = 25.42
r 2 = 10.0082
d 2 = 2.8000
r 3 = ∞
d 3 = 12.0000
n d2 = 1.80610
ν d2 = 40.92
r 4 = ∞
d 4 = 0.3000
r 5 = 38.3752
d 5 = 3.3000
n d3 = 1.77250
ν d3 = 49.60
r 6 = −19.0539
d 6 = (Variable)
r 7 = −27.7782
d 7 = 1.0000
n d4 = 1.80610
ν d4 = 40.92
r 8 = 5.9968
d 8 = 0.7000
(Aspheric)
r 9 = 8.0742
d 9 = 2.3000
n d5 = 1.75520
ν d5 = 27.51
r 10 = −358.1053
d 10 = (Variable)
r 11 = ∞ (Stop)
d 11 = (Variable)
r 12 = 8.4600
d 12 = 2.5000
n d6 = 1.74320
ν d6 = 49.34
(Aspheric)
r 13 = −116.7590
d 13 = 0.1500
(Aspheric)
r 14 = 8.8060
d 14 = 3.0000
n d7 = 1.60311
ν d7 = 60.64
r 15 = −40.0000
d 15 = 0.7000
n d8 = 1.84666
ν d8 = 23.78
r 16 = 4.6054
d 16 = (Variable)
r 17 = 6.7337
d 17 = 1.9700
n d9 = 1.69350
ν d9 = 53.21
(Aspheric)
r 18 = 14.1820
d 18 = (Variable)
r 19 = ∞
d 19 = 1.9000
n d10 = 1.54771
ν d10 = 62.84
r 20 = ∞
d 20 = 0.8000
r 21 = ∞
d 21 = 0.7500
n d11 = 1.51633
ν d11 = 64.14
r 22 = ∞
d 22 = 1.3596
r 23 =
∞ (Image Plane)
Aspherical Coefficients
8th surface
K = 0
A 4 = −2.7926 × 10 −4
A 6 = −5.5281 × 10 −6
A 8 = −3.0031 × 10 −7
A 10 = 0.0000
12th surface
K = 0
A 4 = −1.0549 × 10 −4
A 6 = −1.1474 × 10 −6
A 8 = −5.2653 × 10 −8
A 10 = 0.0000
13th surface
K = 0
A 4 = −4.5663 × 10 −5
A 6 = 6.3255 × 10 −6
A 8 = −3.7416 × 10 −7
A 10 = 0.0000
17th surface
K = 0
A 4 = −3.4690 × 10 −4
A 6 = 2.1996 × 10 −6
A 8 = −1.8422 × 10 −7
A 10 = 0.0000
Zooming Data (∞)
WE
ST
TE
f (mm)
6.00633
10.39946
17.99885
F NO
2.8069
3.3441
4.0747
ω (°)
32.4
18.9
10.9
d 6
0.79862
7.41546
13.08585
d 10
13.68612
7.06296
1.39894
d 11
7.73864
4.51502
1.19986
d 16
1.69904
5.23999
10.27759
d 18
3.54003
3.22246
1.50021
Example 3
r 1 = 31.4475
d 1 = 1.0000
n d1 = 1.80518
ν d1 = 25.42
r 2 = 10.0029
d 2 = 2.8000
r 3 = ∞
d 3 = 12.0000
n d2 = 1.80610
ν d2 = 40.92
r 4 = ∞
d 4 = 0.3000
r 5 = 40.9109
d 5 = 3.1000
n d3 = 1.77250
ν d3 = 49.60
r 6 = −18.5523
d 6 = (Variable)
r 7 = −27.7365
d 7 = 0.9000
n d4 = 1.80610
ν d4 = 40.92
r 8 = 6.1675
d 8 = 0.6000
(Aspheric)
r 9 = 7.8689
d 9 = 2.5000
n d5 = 1.75520
ν d5 = 27.51
r 10 = 541.9130
d 10 = (Variable)
r 11 = ∞ (Stop)
d 11 = (Variable)
r 12 = 6.8303
d 12 = 2.2000
n d6 = 1.74320
ν d6 = 49.34
(Aspheric)
r 13 = −168.3254
d 13 = 0.1500
(Aspheric)
r 14 = 10.3767
d 14 = 2.5000
n d7 = 1.60311
ν d7 = 60.64
r 15 = −100.0000
d 15 = 0.7000
n d8 = 1.84666
ν d8 = 23.78
r 16 = 4.2552
d 16 = (Variable)
r 17 = 6.4363
d 17 = 2.0000
n d9 = 1.58313
ν d9 = 59.38
(Aspheric)
r 18 = 16.8235
d 18 = (Variable)
r 19 = ∞
d 19 = 1.5000
n d10 = 1.54771
ν d10 = 62.84
r 20 = ∞
d 20 = 0.8000
r 21 = ∞
d 21 = 0.7500
n d11 = 1.51633
ν d11 = 64.14
r 22 = ∞
d 22 = 1.3596
r 23 =
∞ (Image Plane)
Aspherical Coefficients
8th surface
K = 0
A 4 = −2.1223 × 10 −4
A 6 = −3.9476 × 10 −6
A 8 = −2.3492 × 10 −7
A 10 = 0.0000
12th surface
K = 0
A 4 = −9.9966 × 10 −5
A 6 = −4.8770 × 10 −6
A 8 = 7.8835 × 10 −7
A 10 = 0.0000
13th surface
K = 0
A 4 = 1.6853 × 10 −4
A 6 = 4.2908 × 10 −6
A 8 = 8.3613 × 10 −7
A 10 = 0.0000
17th surface
K = 0
A 4 = −3.5205 × 10 −4
A 6 = −1.4117 × 10 −6
A 8 = −1.1635 × 10 −7
A 10 = 0.0000
Zooming Data (∞)
WE
ST
TE
f (mm)
6.00728
10.39935
17.99830
F NO
2.7463
3.3017
4.0273
ω (°)
32.4
18.9
11.0
d 6
0.79769
7.29414
13.01239
d 10
13.61214
7.11013
1.39751
d 11
7.70485
4.37777
1.19903
d 16
1.69969
5.42936
10.44566
d 18
3.74084
3.33843
1.50064
Example 4
r 1 = 32.0016
d 1 = 1.0000
n d1 = 1.75520
ν d1 = 27.51
r 2 = 10.0102
d 2 = 2.8000
r 3 = ∞
d 3 = 12.0000
n d2 = 1.80610
ν d2 = 40.92
r 4 = ∞
d 4 = 0.3000
r 5 = 23.5519
d 5 = 3.1000
n d3 = 1.72916
ν d3 = 54.68
r 6 = −24.7555
d 6 = (Variable)
r 7 = −21.9861
d 7 = 0.9000
n d4 = 1.80610
ν d4 = 40.92
(Aspheric)
r 8 = 5.7215
d 8 = 0.6000
(Aspheric)
r 9 = 7.9386
d 9 = 2.5000
n d5 = 1.78470
ν d5 = 26.29
r 10 = −388.5176
d 10 = (Variable)
r 11 = ∞ (Stop)
d 11 = (Variable)
r 12 = 5.6674
d 12 = 4.0000
n d6 = 1.74320
ν d6 = 49.34
(Aspheric)
r 13 = −19.0000
d 13 = 0.7000
n d7 = 1.84666
ν d7 = 23.78
r 14 = 7.7986
d 14 = 0.3000
r 15 = 3.8662
d 15 = 1.0000
n d8 = 1.69350
ν d8 = 53.21
(Aspheric)
r 16 = 3.6817
d 16 = (Variable)
(Aspheric)
r 17 = 13.0325
d 17 = 2.0000
n d9 = 1.48749
ν d9 = 70.23
r 18 = 201.0398
d 18 = (Variable)
r 19 = ∞
d 19 = 1.5000
n d10 = 1.54771
ν d10 = 62.84
r 20 = ∞
d 20 = 0.8000
r 21 = ∞
d 21 = 0.7500
n d11 = 1.51633
ν d11 = 64.14
r 22 = ∞
d 22 = 1.3599
r 23 =
∞ (Image Plane)
Aspherical Coefficients
7th surface
K = 0
A 4 = 2.0496 × 10 −4
A 6 = −3.4919 × 10 −6
A 8 = 7.4208 × 10 −9
A 10 = 0.0000
8th surface
K = 0
A 4 = −3.6883 × 10 −4
A 6 = 3.4613 × 10 −6
A 8 = −9.0209 × 10 −7
A 10 = 0.0000
12th surface
K = 0
A 4 = 5.4882 × 10 −4
A 6 = −1.8282 × 10 −5
A 8 = 1.6707 × 10 −6
A 10 = 0.0000
15th surface
K = 0
A 4 = −8.1049 × 10 −3
A 6 = −4.3019 × 10 −4
A 8 = −3.1973 × 10 −5
A 10 = 0.0000
16th surface
K = 0
A 4 = −6.4092 × 10 −3
A 6 = −7.3362 × 10 −4
A 8 = 2.9898 × 10 −5
A 10 = 0.0000
Zooming Data (∞)
WE
ST
TE
f (mm)
6.00844
10.40337
17.99810
F NO
2.7659
2.9849
4.0444
ω (°)
32.6
19.2
11.3
d 6
0.80018
8.47206
12.07930
d 10
12.67757
5.00686
1.39837
d 11
6.26991
5.19965
1.19782
d 16
1.70036
2.60388
9.42234
d 18
4.14771
4.30945
1.49796
Example 5
r 1 = 37.5126
d 1 = 1.0000
n d1 = 1.78470
ν d1 = 26.29
r 2 = 9.9406
d 2 = 2.8000
(Aspheric)
r 3 = ∞
d 3 = 12.0000
n d2 = 1.80610
ν d2 = 40.92
r 4 = ∞
d 4 = 0.3000
r 5 = 33.8530
d 5 = 3.1000
n d3 = 1.77250
ν d3 = 49.60
r 6 = −21.7247
d 6 = (Variable)
r 7 = −22.9665
d 7 = 0.9000
n d4 = 1.77250
ν d4 = 49.60
r 8 = 7.9115
d 8 = 2.5000
n d5 = 1.71736
ν d5 = 29.52
r 9 = 55.6404
d 9 = (Variable)
r 10 = ∞ (Stop)
d 10 = (Variable)
r 11 = 8.1626
d 11 = 2.2000
n d6 = 1.74320
ν d6 = 49.34
(Aspheric)
r 12 = −278.0091
d 12 = 0.1500
(Aspheric)
r 13 = 7.0366
d 13 = 2.5000
n d7 = 1.60311
ν d7 = 60.64
r 14 = 50.0000
d 14 = 0.7000
n d8 = 1.84666
ν d8 = 23.78
r 15 = 4.2115
d 15 = (Variable)
r 16 = 6.7994
d 16 = 2.0000
n d9 = 1.58313
ν d9 = 59.38
(Aspheric)
r 17 = 13.6965
d 17 = (Variable)
r 18 = ∞
d 18 = 1.5000
n d10 = 1.54771
ν d10 = 62.84
r 19 = ∞
d 19 = 0.8000
r 20 = ∞
d 20 = 0.7500
n d11 = 1.51633
ν d11 = 64.14
r 21 = ∞
d 21 = 1.3586
r 22 =
∞ (Image Plane)
Aspherical Coefficients
2nd surface
K = 0
A 4 = −4.8339 × 10 −5
A 6 = 1.9771 × 10 −7
A 8 = −1.3364 × 10 −8
A 10 = 0.0000
11th surface
K = 0
A 4 = −2.9041 × 10 −4
A 6 = 2.3089 × 10 −5
A 8 = −1.0828 × 10 −6
A 10 = 0.0000
12th surface
K = 0
A 4 = −1.9946 × 10 −4
A 6 = 3.1348 × 10 −5
A 8 = −1.4447 × 10 −6
A 10 = 0.0000
16th surface
K = 0
A 4 = −2.4256 × 10 −4
A 6 = −6.3914 × 10 −6
A 8 = 1.6763 × 10 −7
A 10 = 0.0000
Zooming Data (∞)
WE
ST
TE
f (mm)
6.02709
10.40552
17.99646
F NO
2.6193
3.3129
4.0433
ω (°)
32.3
18.9
11.0
d 6
0.80042
6.82411
13.07966
d 9
13.67313
7.63416
1.39413
d 10
7.94928
4.18630
1.19879
d 15
1.69392
6.18157
10.44930
d 17
3.50041
2.76626
1.49565
The values of conditions (1) to (25) in each example are enumerated below with the values of t LPF and L concerning condition (26). It is noted that conditions (15) to (17) mean (15-1) to (15-3), (16-1) to (16-3) and (17-1) to (17-3), respectively.
Example 1
Example 2
Example 3
Example 4
Example 5
(1)
1.80053
1.79882
1.78926
1.89185
1.68172
(2)
1.58638
1.62590
1.62599
1.63599
1.68575
(3)
1.34851
1.33482
1.33482
1.33482
1.33482
(4)
1.80610
1.80610
1.80610
1.80610
1.80610
(5)
0.91863
0.80674
0.81555
0.65256
0.69581
(6)
0.27229
0.29553
0.29058
0.35869
0.29828
(7)
0.94273
0.31220
0.32096
0.63812
0.74098
(8)
2.31092
2.42296
2.43781
2.46849
2.78836
(9)
1.62212
1.68225
1.69788
1.44993
1.75852
(10)
1.15319
1.17060
1.15739
1.13543
1.11669
(11)
1.96930
1.50318
1.52111
1.28830
1.42870
(12)
1.21850
0.53216
0.53263
0.44969
0.54976
(13)
0.30433
0.31196
0.34434
0.52241
0.29698
(14)
0.36543
0.28287
0.28291
0.28300
0.28105
(15)
1.74534
0.52298
0.41007
1.37605
0.59851
(16)
−0.56154
−0.18250
−0.07300
−0.38421
0.14600
(17)
25.56
36.86
36.86
25.56
36.86
(18)
−1.02346
−2.80812
−2.23928
−1.13863
−2.97167
(19)
0.43618
0.43762
0.43731
0.25625
0.34893
(20)
0.00100
0.33644
0.37601
−0.02491
0.21822
(21)
0.96642
0.64490
0.63618
0.58701
0.48756
(22)
1.0
1.0
1.0
1.0
1.0
(23)
0.04
0.04
0.04
0.04
0.04
(24)
0.0
0.0
0.0
0.0
0.0
(25)
1.06
1.06
1.06
1.06
1.06
a
3.5
3.9
3.7
2.9
2.5
t LPF
0.55
0.58
0.52
0.38
0.30
L
7.30
7.30
7.30
7.30
7.30
Referring to the numerical data about Examples 1 to 5, it is understood that the optical low-pass filter is composed of a plurality of filter elements, and the thickness of the infrared cut filter, etc. is included in such data. Thus, the maximum thickness corresponds to the value of t LPF in the above table, rather than the value of t LPF . It is also understood that any of the following ten combinations of a and t LPF may be used.
1
2
3
4
5
a
3.5
3.9
3.7
2.9
2.5
t LPF
0.55
0.58
0.52
0.38
0.30
6
7
8
9
10
a
2.8
2.7
2.6
3.3
3.1
t LPF
0.25
0.25
0.26
0.24
0.25
Here the diagonal length L of the effective image pickup plane of the electronic image pickup device and the pixel spacing a are explained. FIG. 7 is illustrative of one exemplary pixel array for the electronic image pickup device, wherein R (red), G (green) and B (blue) pixels or four pixels, i.e., cyan, magenta, yellow and green (G) pixels (see FIG. 10 ) are mosaically arranged at the pixel spacing a. The “effective image pickup plane” used herein is understood to mean a certain area in the photoelectric conversion surface on an image pickup device used for the reproduction of a phototaken image (on a personal computer or by a printer). The effective image pickup plane shown in FIG. 7 is set at an area narrower than the total photoelectric conversion surface on the image pickup device, depending on the performance of the optical system used (an image circle that can be ensured by the performance of the optical system). The diagonal length L of an effective image pickup plane is thus defined by that of the effective image pickup plane. Although the image pickup range used for image reproduction may be variable, it is noted that when the zoom lens of the present invention is used on an image pickup apparatus having such functions, the diagonal length L of its effective image pickup plane varies. In that case, the diagonal length L of the effective image pickup plane according to the present invention is defined by the maximum value in the widest possible range for L.
In each example of the present invention, on the image side of the final lens group there is provided a near-infrared cut filter or an optical low-pass filter LF with a near-infrared cut coat surface applied on its entrance side. This near-infrared cut filter or near-infrared cut coat surface is designed to have a transmittance of at least 80% at 600 nm wavelength and a transmittance of up to 10% at 700 nm wavelength. More specifically, the near-infrared cut filter or the near-infrared sharp cut coat has a multilayer structure made up of such 27 layers as mentioned below; however, the design wavelength is 780 nm.
Substrate
Material
Physical Thickness (nm)
λ/4
1st layer
Al 2 O 3
58.96
0.50
2nd layer
TiO 2
84.19
1.00
3rd layer
SiO 2
134.14
1.00
4th layer
TiO 2
84.19
1.00
5th layer
SiO 2
134.14
1.00
6th layer
TiO 2
84.19
1.00
7th layer
SiO 2
134.14
1.00
8th layer
TiO 2
84.19
1.00
9th layer
SiO 2
134.14
1.00
10th layer
TiO 2
84.19
1.00
11th layer
SiO 2
134.14
1.00
12th layer
TiO 2
84.19
1.00
13th layer
SiO 2
134.14
1.00
14th layer
TiO 2
84.19
1.00
15th layer
SiO 2
178.41
1.33
16th layer
TiO 2
101.03
1.21
17th layer
SiO 2
167.67
1.25
18th layer
TiO 2
96.82
1.15
19th layer
SiO 2
147.55
1.05
20th layer
TiO 2
84.19
1.00
21st layer
SiO 2
160.97
1.20
22nd layer
TiO 2
84.19
1.00
23rd layer
SiO 2
154.26
1.15
24th layer
TiO 2
95.13
1.13
25th layer
SiO 2
160.97
1.20
26th layer
TiO 2
99.34
1.18
27th layer
SiO 2
87.19
0.65
Air
The aforesaid near-infrared sharp cut coat has such transmittance characteristics as shown in FIG. 8 .
The low-pass filter LF is provided on its exit surface side with a color filter or coat for reducing the transmission of colors at such a short wavelength region as shown in FIG. 9 , thereby making the color reproducibility of an electronic image much higher.
Preferably, that filter or coat should be designed such that the ratio of the transmittance of 420 nm wavelength with respect to the transmittance of a wavelength in the range of 400 nm to 700 nm at which the highest transmittance is found is at least 15% and that the ratio of 400 nm wavelength with respect to the highest wavelength transmittance is up to 6%.
It is thus possible to reduce a discernible difference between the colors perceived by the human eyes and the colors of the image to be picked up and reproduced. In other words, it is possible to prevent degradation in images due to the fact that a color of short wavelength less likely to be perceived through the human sense of sight can be readily seen by the human eyes.
When the ratio of the 400 nm wavelength transmittance is greater than 6%, the short wavelength region less likely to be perceived by the human eyes would be reproduced with perceivable wavelengths. Conversely, when the ratio of the 420 nm wavelength transmittance is less than 15%, a wavelength region perceivable by the human eyes is less likely to be reproduced, putting colors in an ill-balanced state.
Such means for limiting wavelengths can be more effective for imaging systems using a complementary colors mosaic filter.
In each of the aforesaid examples, coating is applied in such a way that, as shown in FIG. 9 , the transmittance for 400 nm wavelength is 0%, the transmittance for 420 nm is 90%, and the transmittance for 440 nm peaks or reaches 100%.
With the synergistic action of the aforesaid near-infrared sharp cut coat and that coating, the transmittance for 400 nm is set at 0%, the transmittance for 420 nm at 80%, the transmittance for 600 nm at 82%, and the transmittance for 700 nm at 2% with the transmittance for 450 nm wavelength peaking at 99%, thereby ensuring more faithful color reproduction.
The low-pass filter LF is made up of three different filter elements stacked one upon another in the optical axis direction, each filter element having crystal axes in directions where, upon projected onto the image plane, the azimuth angle is horizontal (=0°) and ±45° therefrom. Three such filter elements are mutually displaced by a μm in the horizontal direction and by SQRT(1/2)×a in the ±45° direction for the purpose of moiré control, wherein SQRT means a square root.
The image pickup plane I of a CCD is provided thereon with a complementary colors mosaic filter wherein, as shown in FIG. 10 , color filter elements of four colors, cyan, magenta, yellow and green are arranged in a mosaic fashion corresponding to image pickup pixels. More specifically, these four different color filter elements, used in almost equal numbers, are arranged in such a mosaic fashion that neighboring pixels do not correspond to the same type of color filter elements, thereby ensuring more faithful color reproduction.
To be more specific, the complementary colors mosaic filter is composed of at least four different color filter elements as shown in FIG. 10 , which should preferably have such characteristics as given, below.
Each green color filter element G has a spectral strength peak at a wavelength G P ,
each yellow filter element Y e has a spectral strength peak at a wavelength Y P ,
each cyan filter element C has a spectral strength peak at a wavelength C P , and
each magenta filter element M has spectral strength peaks at wavelengths M P1 , and M P2 , and these wavelengths satisfy the following conditions.
510 nm<G P <540 nm
5 nm< Y P −G P <35 nm
−100 nm< C P −G P <−5 nm
430 nm<M P1 <480 nm
580 nm<M P2 <640 nm
To ensure higher color reproducibility, it is preferred that the green, yellow and cyan filter elements have a strength of at least 80% at 530 nm wavelength with respect to their respective spectral strength peaks, and the magenta filter elements have a strength of 10% to 50% at 530 nm wavelength with their spectral strength peak.
One example of the wavelength characteristics in the aforesaid respective examples is shown in FIG. 11 . The green filter element G has a spectral strength peak at 525 nm. The yellow filter element Y e has a spectral strength peak at 555 nm. The cyan filter element C has a spectral strength peak at 510 nm. The magenta filter element M has peaks at 445 nm and 620 nm. At 530 nm, the respective color filter elements have, with respect to their respective spectral strength peaks, strengths of 99% for G, 95% for Y e , 97% for C and 38% for M.
For such a complementary colors filter, such signal processing as mentioned below is electrically carried out by means of a controller (not shown) (or a controller used with digital cameras).
For Luminance Signals,
Y=|G+M+Y e +C|× 1/4
For chromatic signals,
R−Y =|( M+Y e )−( G+C )|
B−Y =|( M+C )−( G+Y e )|
Through this signal processing, the signals from the complementary colors filter are converted into R (red), G (green) and B (blue) signals.
In this regard, it is noted that the aforesaid near-infrared sharp cut coat may be located anywhere on the optical path, and that the number of low-pass filters LF may be either two as mentioned above or one.
Details of the aperture stop portion in each example are shown in FIG. 12 in conjunction with a four-group arrangement, wherein the first lens group G 1 excepting the optical path-bending prism P is shown. At a stop position on the optical axis between the first lens group G 1 and the second lens group G 2 in the phototaking optical system, there is located a turret 10 capable of brightness control at 0 stage, −1 stage, −2 stage, −3 stage and −4 stage. The turret 10 is composed of an aperture 1 A for 0 stage control, which is defined by a circular fixed space of about 4 mm in diameter (with a transmittance of 100% with respect to 550 nm wavelength), an aperture 1 B for −1 stage correction, which is defined by a transparent plane-parallel plate having a fixed aperture shape with an aperture area nearly half that of the aperture 1 A (with a transmittance of 99% with respect to 550 nm wavelength), and circular apertures 1 C, 1 D and 1 E for −2, −3 and −4 stage corrections, which have the same aperture area as that of the aperture 1 B and are provided with ND filters having the respective transmittances of 50%, 25% and 13% with respect to 550 nm wavelength.
By turning of the turret 10 around a rotating shaft 11 , any one of the apertures is located at the stop position, thereby controlling the quantity of light.
The turret 10 is also designed that when the effective F-number F no ′ is F no ′>a/0.4 μm, an ND filter with a transmittance of less than 80% with respect to 550 nm wavelength is inserted in the aperture. Referring specifically to Example 1, the effective F-number at the telephoto end satisfies the following condition when the effective F-number becomes 9.0 at the −2 stage with respect to the stop-in (0) stage, and the then corresponding aperture is 1 C, whereby any image degradation due to a diffraction phenomenon by the stop is prevented.
Instead of the turret 10 shown in FIG. 12 , it is acceptable to use a turret 10 ′ shown in FIG. 13( a ). This turret 10 ′ capable of brightness control at 0 stage, −1 stage, −2 stage, −3 stage and −4 stage is located at the aperture stop position on the optical axis between the first lens group G 1 and the second lens group G 2 in the phototaking optical system. The turret 10 ′ is composed of an aperture 1 A′ for 0 stage control, which is defined by a circular fixed space of about 4 mm in diameter, an aperture 1 B′ for −1 stage correction, which is of a fixed aperture shape with an aperture area nearly half that of the aperture 1 A′, and apertures 1 C′, 1 D′ and 1 E′ for −2, −3 and −4 stage corrections, which are of fixed shape with decreasing areas in this order. By turning of the turret 10 ′ around a rotating shaft 11 , any one of the apertures is located at the stop position thereby controlling the quantity of light.
Further, optical low-pass filters having varying spatial frequency characteristics are located in association with 1 A′ to 1 D′ of plural such apertures. Then, as shown in FIG. 13( b ), the spatial frequency characteristics of the optical filters are designed in such a way that as the aperture diameter becomes small, they become high, thereby preventing image degradations due to a diffraction phenomenon by stop-down. Each curve in FIG. 13( b ) is indicative of the spatial frequency characteristics of the low-pass filters alone, wherein all the characteristics including diffraction by the stop are set in such a way as to be equal to one another.
The present electronic imaging system constructed as described above may be applied to phototaking systems where object images formed through zoom lenses are received at image pickup devices such as CCDs or silver-halide films, inter alia, digital cameras or video cameras as well as PCs and telephone sets which are typical information processors, in particular, easy-to-carry cellular phones. Given below are some such embodiments.
FIGS. 14 , 15 and 16 are conceptual illustrations of a phototaking optical system 41 for digital cameras, in which the zoom lens of the present invention is built. FIG. 14 is a front perspective view of the outside shape of a digital camera 40 , and FIG. 15 is a rear perspective view of the same. FIG. 16 is a horizontally sectional view of the construction of the digital camera 40 . In this embodiment, the digital camera 40 comprises a phototaking optical system 41 including a phototaking optical path 42 , a finder optical system 43 including a finder optical path 44 , a shutter 45 , a flash 46 , a liquid crystal monitor 47 and so on. As the shutter 45 mounted on the upper portion of the camera 40 is pressed down, phototaking takes place through the phototaking optical system 41 , for instance, the optical path-bending zoom lens according to Example 1. In this case, the optical path is bent by an optical path-bending prism P in the longitudinal direction of the digital camera 40 , i.e., in the lateral direction so that the camera can be slimmed down. An object image formed by the phototaking optical system 41 is formed on the image pickup plane of a CCD 49 via a near-infrared cut filter and an optical low-pass filter LF. The object image received at CCD 49 is shown as an electronic image on the liquid crystal monitor 47 via processing means 51 , which monitor is mounted on the back of the camera. This processing means 51 is connected with recording means 52 in which the phototaken electronic image may be recorded. It is here noted that the recording means 52 may be provided separately from the processing means 51 or, alternatively, it may be constructed in such a way that images are electronically recorded and written therein by means of floppy discs, memory cards, MOs or the like. This camera may also be constructed in the form of a silver halide camera using a silver halide film in place of CCD 49 .
Moreover, a finder objective optical system 53 is located on the finder optical path 44 . An object image formed by the finder objective optical system 53 is in turn formed on the field frame 57 of a Porro prism 55 that is an image erecting member. In the rear of the Porro prism 55 there is located an eyepiece optical system 59 for guiding an erected image into the eyeball E of an observer. It is here noted that cover members 50 are provided on the entrance sides of the phototaking optical system 41 and finder objective optical system 53 as well as on the exit side of the eyepiece optical system 59 .
With the thus constructed digital camera 40 , it is possible to achieve high performance and cost reductions, because the phototaking optical system 41 is constructed of a fast zoom lens having a high zoom ratio at the wide-angle end with satisfactory aberrations and a back focus large enough to receive a filter, etc. therein. In addition, the camera can be slimmed down because, as described above, the optical path of the zoom lens is selectively bent in the longitudinal direction of the digital camera 40 . With the optical path bent in the thus selected direction, the flash 46 is positioned above the entrance surface of the phototaking optical system 42 , so that the influences of shadows on strobe shots of figures can be slackened.
In the embodiment of FIG. 16 , plane-parallel plates are used as the cover members 50 ; however, it is acceptable to use powered lenses. It is understood that depending on ease of camera's layout, the optical path can be bent in either one of the longitudinal and lateral directions.
FIGS. 17 , 18 and 19 are illustrative of a personal computer that is one example of the information processor in which the image-formation optical system of the present invention is built as an objective optical system. FIG. 17 is a front perspective view of a personal computer 300 that is in an uncovered state, FIG. 18 is a sectional view of a phototaking optical system 303 in the personal computer 300 , and FIG. 19 is a side view of the state of FIG. 17 . As shown in FIGS. 17 , 18 and 19 , the personal computer 300 comprises a keyboard 301 via which an operator enters information therein from outside, information processing or recording means (not shown), a monitor 302 on which the information is shown for the operator, and a phototaking optical system 303 for taking an image of the operator and surrounding images. For the monitor 302 , use may be made of a transmission type liquid crystal display device illuminated by backlight (not shown) from the back surface, a reflection type liquid crystal display device in which light from the front is reflected to show images, or a CRT display device. While the phototaking optical system 303 is shown as being built in the right upper portion of the monitor 302 , it may be located somewhere around the monitor 302 or keyboard 301 .
This phototaking optical system 303 comprises on a phototaking optical path 304 an objective lens 112 such as one represented by Example 1 of the optical path-bending zoom lens according to the present invention and an image pickup device chip 162 for receiving an image.
Here an optical low-pass filter LF is additionally applied onto the image pickup device chip 162 to form an integral imaging unit 160 , which can be fitted into the rear end of a lens barrel 113 of the objective lens 112 in one-touch operation. Thus, the assembly of the objective lens 112 and image pickup device chip 162 is facilitated because of no need of alignment or control of surface-to-surface spacing. The lens barrel 113 is provided at its end (not shown) with a cover glass 114 for protection of the objective lens 112 . It is here noted that driving mechanisms for the zoom lens, etc. contained in the lens barrel 113 are not shown.
An object image received at the image pickup device chip 162 is entered via a terminal 166 in the processing means of the personal computer 300 , and displayed as an electronic image on the monitor 302 . As an example, an image 305 taken of the operator is shown in FIG. 17 . This image 305 may be displayed on a personal computer on the other end via suitable processing means and the Internet or telephone line.
FIGS. 20( a ), 20 ( b ) and 20 ( c ) are illustrative of a telephone set that is one example of the information processor in which the image-formation optical system of the present invention is built in the form of a phototaking optical system, especially a convenient-to-carry cellular phone. FIG. 20( a ) and FIG. 20( b ) are a front and a side view of a cellular phone 400 , respectively, and FIG. 34( c ) is a sectional view of a phototaking optical system 405 . As shown in FIGS. 20( a ), 20 ( b ) and 20 ( c ), the cellular phone 400 comprises a microphone 401 for entering the voice of an operator therein as information, a speaker 402 for producing the voice of the person on the other end, an input dial 403 via which the operator enters information therein, a monitor 404 for displaying an image taken of the operator or the person on the other end and indicating information such as telephone numbers, a photo-taking optical system 405 , an antenna 406 for transmitting and receiving communication waves, and processing means (not shown) for processing image information, communication information, input signals, etc. Here the monitor 404 is a liquid crystal display device. It is noted that the components are not necessarily arranged as shown. The phototaking optical system 405 comprises on a phototaking optical path 407 an objective lens 112 such as one represented by Example 1 of the optical path-bending zoom lens according to the present invention and an image pickup device chip 162 for receiving an object image. These are built in the cellular phone 400 .
Here an optical low-pass filter LF is additionally applied onto the image pickup device chip 162 to form an integral imaging unit 160 , which can be fitted into the rear end of a lens barrel 113 of the objective lens 112 in one-touch operation. Thus, the assembly of the objective lens 112 and image pickup device chip 162 is facilitated because of no need of alignment or control of surface-to-surface spacing. The lens barrel 113 is provided at its end (not shown) with a cover glass 114 for protection of the objective lens 112 . It is here noted that driving mechanisms for the zoom lens, etc. contained in the lens barrel 113 are not shown.
An object image received at the image pickup device chip 162 is entered via a terminal 166 in processing means (not shown), so that the object image can be displayed as an electronic image on the monitor 404 and/or a monitor at the other end. The processing means also include a signal processing function for converting information about the object image received at the image pickup device chip 162 into transmittable signals, thereby sending the image to the person at the other end.
The present invention provides a zoom lens that is well received at a collapsible lens mount with reduced thickness, has a high zoom ratio and shows excellent image-formation capability even upon rear-focusing. With this zoom lens, it is possible to thoroughly slim down video cameras or digital cameras. | A zoom lens with an easily bendable optical path has high optical specification performance such as a high zoom ratio, a wide-angle arrangement, a small F-number and reduced aberrations. It includes a first lens group G 1 remaining fixed during zooming, a second lens group G 2 having negative refracting power and moving during zooming, a third lens group G 3 having positive refracting power and moving during zooming, and a fourth lens group G 4 having positive refracting power and moving during zooming and focusing. The first lens group comprises, in order from an object side thereof, a negative meniscus lens component convex on an object side thereof, a reflecting optical element for bending an optical path and a positive lens. Upon focusing on an infinite object point, the fourth lens group G 4 moves in a locus opposite to that of movement of the third lens group G 3 during zooming. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hydraulic working oil compositions for use in buffers and more particularly to such oil compositions suitable for use in car suspension devices such as shock absorbers, active suspensions, stay dampers and engine dampers.
2. Prior Art
As conventional hydraulic working oils which have hitherto been used in car buffer devices such as shock absorbers, active suspensions, stay dampers and engine dampers, there have been known those incorporated with a phosphoric acid ester and/or a phosphorus acid ester to provide the car buffer devices with friction-reducing properties and wear-preventing properties. In addition, there have also widely been used such hydraulic working oils in which are additionally used oily agents such as a fatty acid, aliphatic alcohol and fatty acid ester to further improve the working oils in friction-reducing properties.
Hydraulic working oils are those which are required to be capable of reducing friction at friction surfaces simultaneously with preventing wear of the friction surfaces. Recently, there have been increasingly used bush members impregnated with a Teflon resin in attempts to reduce friction at friction surfaces by having resort to such material or substance as above. Further, gas-sealed type and damping force-variable type buffers have particularly been increasingly used and, therefore, load applied to the friction surfaces of the buffers has been increased whereby conditions under which the buffers are used have come to be severe.
Consequently, Japanese Patent Application Laid-Open Gazette No. Hei 5-255683 (No. 255683/93) discloses, as a hydraulic working oil exhibiting excellent wear resistance and Friction characteristics even under severe conditions, a composition comprising a base oil which contains therein a phosphorus-containing compound such as a phosphoric acid ester or phosphorous acid ester and a nitrogen-containing compound comprising C 12 -diethanolamine. The present inventors also found out that compositions comprising as essential components a phosphorus-containing compound such as a phosphoric acid ester or phosphorous acid ester, and a nitrogen-containing compound having a specific structure, in addition to a base lubricating oil, are particularly excellent in durability (little degradation with the time of use) of friction-reducing effect as a hydraulic working oil for a buffer, and previously filed a patent application based on this finding (Japanese Patent Application No. Hei 6-37528).
Although hydraulic working oil compositions for a buffer which have an excellent wear-preventing effect can be obtained by the combined use of the nitrogen-containing compound, which is described in the above two Japanese patent applications, and the phosphorus-containing compound; however, they have been found to raise problems because their storage stability is deteriorated so as to produce sludges when the content of the nitrogen-containing compound is increased, while their durability of friction-reducing effect is deteriorated when the content thereof is decreased to such an extent as not to worsen their storage stability.
SUMMARY OF THE INVENTION
A primary object of this invention is to provide hydraulic working oil compositions for a buffer which are excellent not only in durability (little degradation with the time of use) of friction-reducing and wear-preventing effects but also in storage stability. A further object of this invention is to provide hydraulic working oil compositions for a buffer which are excellent in adaptability to novel Teflon resin impregnated bush members.
The present inventors made intensive studies to achieve the above objects and, as the result of their studies, found that the above objects can be achieved by the combined use of [I] a phosphorus-containing compound having a specific structure, [II] a nitrogen-containing compound having a specific structure and [III] an aliphatic monoamine having a specific structure as essential components in a lubricating oil as a base oil, in respective specified amounts, thus completing this invention.
The present invention will now be described in more detail.
The primary object of this invention is achieved by providing a hydraulic working oil composition prepared by adding to a lubricating oil as a base oil the following ingredients as essential components [II] at least one kind of a phosphorus-containing compound selected from the group consisting of the following components (A) and (B):
(A) a phosphoric acid ester represented by the following general formula (1) ##STR1##
(B) a phosphorous acid ester represented by the following general formula (2) ##STR2## wherein R 1 and R 4 are each an alkyl or alkenyl group having 4-22 carbon atoms, an aryl, alkylaryl or arylalkyl group each having 6-22 carbon atoms; R 2 and R 3 , and R 5 and R 6 may be identical with, or different from, each other, respectively, and these R 2 , R 3 , R 5 and R 6 are each hydrogen, an alkyl or alkenyl group having 1-22 carbon atoms, an aryl, alkylaryl or arylalkyl group having 6-22 carbon atoms, and [II] at least one kind of a nitrogen-containing compound selected from the group consisting of the following components (C) to (E):
(C) an alkyleneoxide adduct of an aliphatic monoamine represented by the following general formula (3) ##STR3## wherein R 7 is an alkyl or alkenyl group having 6-22 carbon atoms, R 8 and R 9 may be identical with, or different from, each other, and these R 8 and R 9 are each an alkylene group having 2-4 carbon atoms, a and b may be identical with, or different from, each other and are an integer of 0 to 10, and a+b=1 to 10,
(D) an aliphatic polyamine represented by the following general formula (4) ##STR4## wherein R 10 is an alkyl or alkenyl group having 6-22 carbon atoms, R 11 is an alkylene group having 2-4 carbon atoms, and c is an integer of 1 to 4, and
(E) a salt of the above aliphatic polyamine (D) with an aliphatic acid having 6-22 carbon atoms, and
[III] (F) an aliphatic monoamine represented by the following general formula (5)
R.sup.12 --NH.sub.2 ( 5)
wherein R 12 is an alkyl or alkenyl group having 6-22 carbon atoms, the compounds [I] to [III] being each required to satisfy the following formulas (6) to (8):
W.sub.I =0.1-5.0 (6)
W.sub.I /(W.sub.II +W.sub.III)=1.5-20.0 (7)
W.sub.II /W.sub.III =0.2-2.0 ( 8 )
Wherein W I , W II and W III represent the contents of components [I], [II] and [III] in the hydraulic working oil composition, respectively, and the contents being each expressed in % by weight based on the total weight of the composition.
The lubricating oils used as a base oil in this invention are not particularly limited, and both mineral oils and synthetic oils which are usually used as a base oil for lubricating oils may be used in this invention.
The mineral oil-type lubricating oils which may be used as a base oil, include paraffinic and naphthenic oils obtained by refining, for example, lubricating oil fractions obtained by the atmospheric and reduced-pressure distillation of a crude oil, by means of a suitable combination of solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, clay treatment, and the like. The synthetic oil-type lubricating oils which may be used as a base oil, include poly α-olefins (polybutene, 1-octene oligomers, 1-decene oligomers, etc.), alkylbenzenes, alkylnaphthalenes, diesters (ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate, etc.), polyol esters (trimethylolpropane caprylate, trimethylolpropane peralgonate, pentaerithritol 2-ethyl hexanoate, pentaerithritol peralgonate, etc.), polyoxyalkylene glycol, polyphenyl ethers, silicone oil and perfluoroalkyl ethers. The lubricating oils used as a base oil are hereinafter sometimes referred to as "base lubricating oils" for simplicity. The base lubricating oils may be used singly of jointly, but the mineral oil-type base lubricating oils are preferably used from the standpoint of their adaptability to, or compatibility with, gum sealants in this invention.
The base lubricating oils used in this invention are optional in viscosity, but those having a viscosity of 8-60 cSt, preferably 10-40 cSt, at 40° C. are usually used from necessity for their applicability to damping force required in general buffers.
The component [I] which is an essential additive to be added to a base lubricating oil according to this invention is at least one phosphorus-containing compound selected from the group consisting of (A) a phosphoric acid ester represented by the following general formula (1), (B) a phosphorous acid ester represented by the following general formula (2): ##STR5##
In these formulae (1) and (2), R 1 and R 4 are each a straight-chain or branched-chain alkyl or alkenyl group having 4-22 carbon atoms, an aryl, alkylaryl or arylalkyl group having a straight-chain or branched-chain alkyl group, the aryl, alkylaryl and arylalkyl groups each having 6-22 carbon atoms; R 2 and R 3 , and R 5 and R 6 , may be identical with, or different from, each other, respectively, and these R 2 , R 3 , R 5 and R 6 are each a straight-chain or branched-chain alkyl or alkenyl group having 1-22 carbon atoms, an aryl, alkylaryl or arylalkyl group each having 6-22 carbon atoms, the alkyl group in these alkylaryl and arylalkyl groups being a straight-chain or branched-chain alkyl group.
The R 1 and R 4 each include an alkyl group such as butyl groups (including all isomeric groups), pentyl groups (including all isomeric groups), hexyl groups (including all isomeric groups), heptyl groups (including all isomeric groups), octyl groups (including all isomeric groups), nonyl groups (including all isomeric groups), decyl groups (including all isomeric groups), undecyl groups (including all isomeric groups), dodecyl groups (including all isomeric groups), tridecyl groups (including all isomeric groups), tetradecyl groups (including all isomeric groups), pentadecyl groups (including all isomeric groups), hexadecyl groups (including all isomeric groups), heptadecyl groups (including all isomeric groups), octadecyl groups (including all isomeric groups), nonadecyl groups (including all isomeric groups), eicosyl groups (including all isomeric groups), heneicosyl groups (including all isomeric groups) and docosyl groups (including all isomeric groups); an alkenyl group such as butenyl groups (including all isomeric groups), pantenyl groups (including all isomeric groups), hexenyl groups (including all isomeric groups), heptenyl groups (including all isomeric groups), octenyl groups (including all isomeric groups), nonenyl groups (including all isomeric groups), decenyl groups (including all isomeric groups), undecenyl groups (including all isomeric groups), dodecenyl groups (including all isomeric groups), tridecenyl groups (including all isomeric groups), tetradecenyl groups (including all isomeric groups), pentadecenyl groups (including all isomeric groups), hexadecenyl groups (including all isomeric groups), heptadecenyl groups (including all isomeric groups), octadecenyl groups (including all isomeric groups), nonadecenyl groups (including all isomeric groups), eicosenyl groups (including all isomeric groups), heneicosenyl groups (including all isomeric groups) and docosenyl groups (including all isomeric groups); an aryl group such as a phenyl group and naphtyl groups (including all isomeric groups); an alkylaryl group such as tolyl groups (including all isomeric groups), ethylphenyl groups (including all isomeric groups), propylphenyl groups (including all isomeric groups), butylphenyl groups (including all isomeric groups), pentylphenyl groups (including all isomeric groups), hexylphenyl groups (including all isomeric groups), heptylphenyl groups (including all isomeric groups), octylphenyl groups (including all isomeric groups), nonylphenyl groups (including all isomeric groups), decylphenyl groups (including all isomeric groups), undecylphenyl groups (including all isomeric groups), dodecylphenyl groups (including all isomeric groups), tridecylphenyl groups (including all isomeric groups), tetradecylphenyl groups (including all isomeric groups), pentadecylphenyl groups (including all isomeric groups), hexadecylphenyl groups (including all isomeric groups), xylyl groups (including all isomeric groups), ethylmethylphenyl groups (including all isomeric groups), diethylphenyl groups (including all isomeric groups), dipropylphenyl groups (including all isomeric groups), dibutylphenyl groups (including all isomeric groups), methylnaphtyl groups (including all isomeric groups), ethylnaphtyl groups (including all isomeric groups), propylnaphtyl groups (including all isomeric groups), butylnaphtyl groups (including all isomeric groups), dimethylnaphtyl groups (including all isomeric groups), ethylmethylnaphtyl groups (including all isomeric groups), diethylnaphtyl groups (including all isomeric groups), dipropylnaphtyl groups (including all isomeric groups) and dibutylnaphtyl groups (including all isomeric groups); an arylalkyl group such as a benzyl group, phenylethyl groups (including all isomeric groups) and phenylpropyl groups (including all isometric groups).
On the other hand, the R 2 and R 3 , and the R 5 and R 6 , each include hydrogen, an alkyl group such as methyl group, ethyl group, propyl groups (including all isomeric groups), butyl groups (including all isomeric groups), pentyl groups (including all isomeric groups), hexyl groups (including all isomeric groups), heptyl groups (including all isomeric groups), octyl groups (including all isomeric groups), nonyl groups (including all isomeric groups), decyl groups (including all isomeric groups), undecyl groups (including all isomeric groups), dodecyl groups (including all isomeric groups), tridecyl groups (including all isomeric groups), tetradecyl groups (including all isomeric groups), pentadecyl groups (including all isomeric groups), hexadecyl groups (including all isomeric groups), heptadecyl groups (including all isomeric groups), octadecyl groups (including all isomeric groups), nonadecyl groups (including all isomeric groups), eicosyl groups (including all isomeric groups), heneicosyl groups (including all isomeric groups) and docosyl groups (including all isomeric groups); an alkenyl group such as butenyl groups (including all isomeric groups), pentenyl groups (including all isomeric groups), hexenyl groups (including all isomeric groups), heptenyl groups (including all isomeric groups), octenyl groups (including all isomeric groups), nonenyl groups (including all isomeric groups), decenyl groups (including all isomeric groups), undecenyl groups (including all isomeric groups), dodecenyl groups (including all isomeric groups), tridecenyl groups (including all isomeric groups), tetradecenyl groups (including all isomeric groups), pentadecenyl groups (including all isomeric groups), hexadecenyl groups (including all isomeric groups), heptadecenyl groups (including all isomeric groups), octadecenyl groups (including all isomeric groups), nonadecenyl groups (including all isomeric groups), eicosenyl groups (including all isomeric groups), heneicosenyl groups (including all isomeric groups) and docosenyl groups (including all isomeric groups); an aryl group such as a phenyl group and naphtyl groups (including all isomeric groups); an alkylaryl group such as tolyl groups (including all isomeric groups), ethylphenyl groups (including all isomeric groups), propylphenyl groups (including all isomeric groups), butylphenyl groups (including all isomeric groups), pentylphenyl groups (including all isomeric groups), hexylphenyl groups (including all isomeric groups), heptylphenyl groups (including all isomeric groups), octylphenyl groups (including all isomeric groups), nonylphenyl groups (including all isomeric groups), decylphenyl groups (including all isomeric groups), undecylphenyl groups (including all isomeric groups), dodecylphenyl groups (including all isomeric groups), tridecylphenyl groups (including all isomeric groups), tetradecylphenyl groups (including all isomeric groups), pentadecylphenyl groups (including all isomeric groups), hexadecylphenyl groups (including all isomeric groups), xylyl groups (including all isomeric groups), ethylmethylphenyl groups (including all isomeric groups), diethylphenyl groups (including all isomeric groups), dipropylphenyl groups (including all isomeric groups), dibutylphenyl groups (including all isomeric groups), methylnaphtyl groups (including all isomeric groups), ethylnaphtyl groups (including all isomeric groups), propylnaphtyl groups (including all isomeric groups), butylnaphtyl groups (including all isomeric groups), dimethylnaphtyl groups (including all isomeric groups), ethylmethylnaphtyl groups (including all isomeric groups), diethylnaphtyl groups (including all isomeric groups), dipropylnaphtyl groups (including all isomeric groups) and dibutylnaphtyl groups (including all isomeric groups); an arylalkyl group such as benzyl groups phenylethyl groups (including all isomeric groups) and phenylpropyl groups (including all isomeric groups).
From the standpoint of its excellency particularly in wear-preventing and friction-reducing effects, the preferable phosphoric acid ester of the component (a) used in this invention is a diester compound of the formula (1) wherein R 1 and R 2 are each a member selected from a straight-chain or branched-chain alkyl or alkenyl group having 6 to 20 carbon atoms and a monoalkylphenyl group having 14-20 carbon atoms in which the alkyl is a straight-chain or branched-chain one, and R 3 is hydrogen. The more preferable phosphoric acid ester is a diester compound of the formula (1) wherein R 1 and R 2 are each a member selected from a straight-chain or branched-chain alkyl or alkenyl group having 8 to 18 carbon atoms, and R 3 is hydrogen.
The preferable phosphoric acid diesters (a) include dioctyl acid phosphates (including all isomers), didecyl acid phosphates (including all isomers), didodecyl acid phosphates (including all isomers), ditetradecyl acid phosphates (including all isomers), dihexadecyl acid phosphate (including all isomers), dioctadecyl acid phosphates (including all isomers), dioctadecenyl acid phosphates (including all isomers) and mixtures thereof.
In the same manner as in the phosphoric acid ester of the formula (1), from the standpoint of its excellency particularly in wear-preventing and friction-reducing effects the preferable phosphorous acid ester of the component (b) used in this invention is a diester compound of the formula (2) wherein R 4 and R 5 are each a member selected from a straight-chain or branched-chain alkyl or alkenyl group having 6 to 20 carbon atoms and a monoalkylphenyl group having 14-20 carbon atoms in which the alkyl is a straight-chain or branched-chain one, and R 6 is hydrogen. The more preferable phosphorous acid ester is a diester compound of the formula (2) wherein R 4 and R 5 are each a straight-chain alkyl or alkenyl group having 8 to 18 carbon atoms, and R 6 is hydrogen.
The more preferable phosphorous acid diesters (b) include dioctyl hydrogen phosphites (including all isomers), didecyl hydrogen phosphites (including all isomers), didodecyl hydrogen phosphites (including all isomers), ditetradecyl hydrogen phosphites (including all isomers), dihexadecyl hydrogen phosphites (including all isomers), dioctadecyl hydrogen phosphites (including all isomers), dioctadecenyl hydrogen phosphites (including all isomers) and mixtures thereof.
The component [II] which is an essential additive to be added to a base lubricating oil according to this invention is at least one kind of a nitrogen-containing compound selected from the group consisting of (C) an alkyleneoxide adduct of an aliphatic monoamine, (D) an aliphatic polyamine and (E) an aliphatic acid salt of an aliphatic polyamine.
The alkyleneoxide adduct of an aliphatic monoamine (C) of the component [II] defined herein means a compound represented by the Following general formula (3) ##STR6## wherein R 7 is a straight-chain or branched-chain alkyl or alkenyl group having 6-22, preferably 8-18, carbon atoms, R 8 and R 9 may be identical with, or different from, each other, and these R 8 and R 9 are each a straight-chain or branched-chain alkylene group having 2-4 carbon atoms, a and b may be identical with, or different from, each other, and are each an integer of 0 to 10 and a+b=1 to 10, preferably 1 to 5.
The R 7 is exemplified by an alkyl group such as hexyl groups (including all isomeric group), heptyl groups (including all isomeric group), octyl groups (including all isomeric group), nonyl groups (including all isomeric group), decyl groups (including all isomeric group), undecyl groups (including all isomeric group), dodecyl groups (including all isomeric group), tridecyl groups (including all isomeric group), tetradecyl groups (including all isomeric group), pentadecyl groups (including all isomeric group), hexadecyl groups (including all isomeric group), heptadecyl groups (including all isomeric group), octadecyl groups (including all isomeric group), nonadecyl groups (including all isomeric group), eicosyl groups (including all isomeric group), heneicosyl groups (including all isomeric group) and docosyl groups (including all isomeric group); and an alkenyl group such as octenyl groups (including all isomeric group), nonenyl groups (including all isomeric group), decenyl groups (including all isomeric group), undecenyl groups (including all isomeric group), docenyl groups (including all isomeric group), tridecenyl groups (including all isomeric group), tetradecenyl groups (including all isomeric group), pentadecenyl groups (including all isomeric group), hexadecenyl groups (including all isomeric group), peptadecenyl groups (including all isomeric group), octadecenyl groups (including all isomeric group), nonadecenyl groups (including all isomeric group), eicosenyl groups (including all isomeric group), heneicosenyl groups (including all isomeric group) and docosenyl groups (including all isomeric group); and an aliphatic group derived from fats and oils such as tallow, hardened tallow, coconut oil and soybean oil. The R 8 includes an ethylene group, trimethylene group, 1-methylethylene group, 2-methylethylene group, tetramethylene group, 1-methyltrimethylene group, 2-methyltrimethylene group, 3-methyltrimethylene group, 1-ethylethylene group, 2-ethylethylene group, 1,1-dimethylethylene group, 1,2-dimethylethylene group and 2,2-dimethylethylene group.
From the standpoint of its excellency particularly in friction-reducing effect, the alkyleneoxide adduct of an aliphatic monoamine (C) of the component [II] used in this invention is preferably a compound of the formula (3) wherein R 7 is a member selected from a straight-chain alkyl or straight-chain alkenyl group having 8 to 18 carbon atoms and R 8 and R 9 are each ethylene group or propylene group.
Particularly preferable compounds as the alkyleneoxide adduct of an aliphatic monoamine (C) of the component [II] used in this invention include octyl amine (capryl amine), decyl amine, dodecyl amine (lauryl amine), tetradecyl amine (myristyl amine), hexadecyl amine (palmityl amine), octadecyl amine (stearyl amine), 9-octadecenyl amine (oleyl amine), or an ethyleneoxide adduct or propyleneoxide adduct of an aliphatic monoamine derived from fats and oils such as tallow, hardened tallow, coconut oil or soybean oil, and a mixture thereof.
The aliphatic polyamine (D) of the component [II] defined herein means compounds represented by the following general formula (4) ##STR7## wherein R 10 is a straight-chain or branched-chain alkyl or alkenyl group having 6-22 carbon atoms, R 11 is a straight-chain or branched-chain alkylene group having 2-4 carbon atoms, and c is an integer of 1 to 4.
The R 10 is exemplified by an alkyl group such as hexyl groups (including all isomeric group), heptyl groups (including all isomeric group), octyl groups (including all isomeric group), nonyl groups (including all isomeric group), decyl groups (including all isomeric group), undecyl groups (including all isomeric group), dodecyl groups (including all isomeric group), tridecyl groups (including all isomeric group), tetradecyl groups (including all isomeric group), pentadecyl groups (including all isomeric group), hexadecyl groups (including all isomeric group), heptadecyl groups (including all isomeric group), octadecyl groups (including all isomeric group), nonadecyl groups (including all isomeric group), eicosyl groups (including all isomeric group), heneicosyl groups (including all isomeric group) and docosyl groups (including all isomeric group); and an alkenyl group such as octenyl groups (including all isomeric group), nonenyl groups (including all isomeric group), decenyl groups (including all isomeric group), undecenyl groups (including all isomeric group), docenyl groups (including all isomeric group), tridecenyl groups (including all isomeric group), tetradecenyl groups (including all isomeric group), pentadecenyl groups (including all isomeric group), hexadecenyl groups (including all isomeric group), peptadecenyl groups (including all isomeric group), octadecenyl groups (including all isomeric group), nonadecenyl groups (including all isomeric group), eicosenyl groups (including all isomeric group), heneicosenyl groups (including all isomeric group) and docosenyl groups (including all isomeric group); and an aliphatic group derived from fats and oils such as tallow, hardened tallow, coconut oil and soybean oil. The R 11 includes an ethylene group, trimethylene group, 1-methylethylene group, 2-methylethylene group, tetramethylene group, 1-methyltrimethylene group, 2-methyltrimethylene group, 3-methyltrimethylene group, 1-ethylethylene group, 2-ethylethylene group, 1,1-dimethylethylene group, 1,2-dimethylethylene group and 2,2-dimethylethylene group.
The aliphatic polyamine (D), which is represented by formula (4) and is among the components [II] used in this invention is preferably a specified compound of the formula (4) in which R 10 is a straight-chain alkyl or alkenyl group having 8-18 carbon atoms, and R 11 is an ethylene group or propylene group and a is an integer of 1, in view of the excellent wear-reducing performance of said specified compound.
In the component [II] used in the present invention, particularly preferable compounds as the above aliphatic polyamine (D) represented by the formula (4) include an aliphatic polyamine such as octyl ethylenediamine, octyl propylenediamine, decyl ethylenediamine, decyl propylenediamine, dodecyl ethylenediamine (lauryl ethylenediamine), dodecyl propylenediamine (lauryl propylenediamine), tetradecyl ethylenediamine (myristyl ethylenediamine), tetradecyl propylenediamine (myristyl propylenediamine), hexadecyl ethylenediamine (cetyl ethylenediamine), hexadecyl propylenediamine (cetyl propylenediamine), octadecyl ethylenediamine (stearyl ethylenediamine), octadecyl propylenediamine (stearyl propylenediamine), octadecenyl ethylenediamine (oleyl ethylenediamine), octadecenyl propylenediamine (oleyl propylenediamine), tallow ethylenediamine, tallow propylenediamine, hardened tallow ethylenediamine, hardened tallow propylenediamine, coconut ethylenediamine, coconut propylenediamine, soybean ethylenediamine, soybean propylenediamine and a mixture thereof.
The component (E), which is among the components [II] used in the present invention, is a salt of the aliphatic polyamine (D) with an aliphatic acid having 6-22 carbon atoms.
The aliphatic acid having 6-22 carbon atoms to be used in forming the salt may be a straight-chain or branched-chain one, and may be a saturated or unsaturated one. Among them, the straight-chain aliphatic acid having 8-18 carbon atoms is preferably used.
The preferable aliphatic acids include octanoic acid (caprylic acid), decanoic acid (capric acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), octadecenoic acid (oleic acid), and tallow aliphatic acid, hardened tallow aliphatic acid, coconut oil aliphatic acid, soybean oil aliphatic acid and a mixture thereof.
The particularly preferable component (E) which is among the components [II] according to the present invention, includes a salt of at least one kind of an aliphatic polyamine with at least one kind of an aliphatic acid. The aliphatic polyamine is a member selected from the group consisting of octyl ethylenediamine, octyl propylenediamine, decyl ethylenediamine, decyl propylenediamine, dodecyl ethylenediamine (lauryl ethylenediamine), dodecyl propylenediamine (lauryl propylenediamine), tetradecyl ethylenediamine (myristyl ethylenediamine), tetradecyl propylenediamine (myristyl propylenediamine), hexadecyl ethylenediamine (cetyl ethylenediamine), hexadecyl propylenediamine (cetyl propylenediamine), octadecyl ethylenediamine (stearyl ethylenediamine), octadecyl propylenediamine (stearyl propylenediamine), octadecenyl ethylenediamine (oleyl ethylenediamine), octadecenyl propylenediamine (oleyl propylenediamine), tallow ethylenediamine, tallow propylenediamine, hardened tallow ethylenediamine, hardened tallow propylenediamine, coconut ethylenediamine, coconut propylenediamine, soybean ethylenediamine, soybean propylenediamine and the like. The aliphatic acid is a member selected from the group consisting of octanoic acid (caprylic acid), decanoic acid (captic acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), 9-octadecenic acid (oleic acid), tallow aliphatic acid, hardened tallow aliphatic acid, coconut oil aliphatic acid, soybean oil aliphatic acid and the like.
Furthermore, there is preferably used a salt in which one aliphatic acid per nitrogen atom in the aliphatic polyamine has been reacted with the aliphatic polyamine the salt being obtainable by reacting said acid with polyamine in equivalent amounts. This salt includes octyl ethylenediamine-dilaurate, octyl ethylenediamine-dimyristate, octyl ethylenediamine-dipalmitate, octyl ethylenediamine-distearate, octyl ethylenediamine-dioleate, octyl ethylenediamine-ditallow aliphatic acid salt, octyl ethylenediamine-dihardened tallow aliphatic acid salt, octyl ethylenediamine-dicoconut aliphatic acid salt, octyl ethylenediamine-disoybean aliphatic acid salt; octyl propylenediamine-dilaurate, octyl propylenediamine-dimyristate, octyl propylenediamine-dipalmitate, octyl propylenediamine-distearate, octyl propylenediamine-dioleate, octyl propylenediamine-ditallow aliphatic acid salt, octyl propylenediamine-dihardened tallow aliphatic acid salt, octyl propylenediamine-dicoconut aliphatic acid salt, octyl propylenediamine-disoybean aliphatic acid salt; decyl ethylenediamine-dilaurate, decyl ethylenediamine-dimyristate, decyl ethylenediamine-dipalmitate, decyl ethylenediamine-distearate, decyl ethylenediamine-dioleate, decyl ethylenediamine-ditallow aliphatic acid salt, decyl ethylenediamine-dihardened tallow aliphatic acid salt, decyl ethylenediamine-dicoconut aliphatic acid salt, decyl ethylenediamine-disoybean aliphatic acid salt; decyl propylenediamine-dilaurate, decyl propylenediamine-dimyristate, decyl propylenediamine-dipalmitate, decyl propylenediamine-distearate, decyl propylenediamine-dioleate, decyl propylenediamine-ditallow aliphatic acid salt, decyl propylene diamine-dihardened tallow aliphatic acid salt, decyl propylene diamine-dicoconut aliphatic acid salt, decyl propylene diamine-disoybean aliphatic acid salt; lauryl ethylenediamine-dilaurate, lauryl ethylenediamine-dimyristate, lauryl ethylenediamine-dipalmitate, lauryl ethylenediamine-distearate, lauryl ethylenediamine-dioleate, lauryl ethylenediamine-ditallow aliphatic acid salt, lauryl ethylenediamine-dihardened tallow aliphatic acid salt, lauryl ethylenediamine-dicoconut aliphatic acid salt, lauryl ethylenediamine-disoybean aliphatic acid salt; lauryl propylenediamine-dilaurate, lauryl propylene diamine-dimyristate, lauryl propylenediamine-dipalmitate, lauryl propylenediamine-distearate, lauryl propylenediamine-dioleate, lauryl propylenediamine-ditallow aliphatic acid salt, lauryl propylenediamine-dihardened tallow aliphatic acid salt, lauryl propylenediamine-dicoconut aliphatic acid salt, lauryl propylenediamine-disoybean aliphatic acid salt; myristyl ethylenediamine-dilaurate, myristyl ethylenediamine-dimyristate, myristyl ethylenediamine-dipalmitate, myristyl ethylenediamine-distearate, myristyl ethylenediamine-dioleate, myristyl ethylenediamine-ditallow aliphatic acid salt, myristyl ethylenediamine-dihardened tallow aliphatic acid salt, myristyl ethylenediamine-dicoconut aliphatic acid salt, myristyl ethylenediamine-disoybean aliphatic acid salt; myristyl propylenediamine-dilaurate, myristyl propylenediamine-dimyristate, myristyl propylenediamine-dipalmitate, myristyl propylenediamine-distearate, myristyl propylenediamine-dioleate, myristyl propylenediamine-ditallow aliphatic acid salt, myristyl propylenediamine-dihardened tallow aliphatic acid salt, myristyl propylenediamine-dicoconut aliphatic acid salt, myristyl propylenediamine-disoybean aliphatic acid salt; cetyl ethylenediamine-dilaurate, cetyl ethylenediamine-dimyristate, cetyl ethylenediamine-dipalmitate, cetyl ethylenediamine-distearate, cetyl ethylenediamine-dioleate, cetyl ethylenediamine-ditallow aliphatic acid salt, cetyl ethylenediamine-dihardened tallow aliphatic acid salt, cetyl ethylenediamine-dicoconut aliphatic acid salt, cetyl ethylenediamine-disoybean aliphatic acid salt; cetyl propylene diamine-dilaurate, cetyl propylenediamine-dimyristate, cetyl propylenediamine-dipalmitate, cetyl propylenediamine-distearate, cetyl propylenediamine-dioleate, cetyl propylenediamine-ditallow aliphatic acid salt, cetyl propylenediamine-dihardened tallow aliphatic acid salt, cetyl propylenediamine-dicoconut aliphatic acid salt, cetyl propylenediamine-disoybean aliphatic acid salt; stearyl ethylenediamine-dilaurate, stearyl ethylenediamine-dimyristate, stearyl ethylenediamine-dipalmitate, stearyl ethylenediamine-distearate, stearyl ethylenediamine-dioleate, stearyl ethylenediamine-ditallow aliphatic acid salt, stearyl ethylenediamine-dihardened tallow aliphatic acid salt, stearyl ethylenediamine-dicoconut aliphatic acid salt, stearyl ethylenediamine-disoybean aliphatic acid salt; stearyl propylene diamine-dilaurate, stearyl propylenediamine-dimyristate, stearyl propylenediamine-dipalmitate, stearyl propylenediamine-distearate, stearyl propylenediamine-dioleate, stearyl propylenediamine-ditallow aliphatic acid salt, stearyl propylenediamine-dihardened tallow aliphatic acid salt, stearyl propylenediamine-dicoconut aliphatic acid salt, stearyl propylenediamine-disoybean aliphatic acid salt; oleyl ethylenediamine-dilaurate, oleyl ethylenediamine-dimyristate, oleyl ethylenediamine-dipalmitate, oleyl ethylenediamine-distearate, oleyl ethylenediamine-dioleate, oleyl ethylenediamine-ditallow aliphatic acid salt, oleyl ethylenediamine-dihardened tallow aliphatic acid salt, oleyl ethylenediamine-dicoconut aliphatic acid salt, oleyl ethylenediamine-disoybean aliphatic acid salt; oleyl propylene diamine-dilaurate, oleyl propylenediamine-dimyristate, oleyl propylenediamine-dipalmitate, oleyl propylenediamine-distearate, oleyl propylenediamine-dioleate, oleyl propylenediamine-ditallow aliphatic acid salt, oleyl propylenediamine-dihardened tallow aliphatic acid salt, oleyl propylenediamine-dicoconut aliphatic acid salt, oleyl propylenediamine-disoybean aliphatic acid salt; tallow ethylenediamine-dilaurate, tallow ethylenediamine-dimyristate, tallow ethylenediamine-dipalmitate, tallow ethylenediamine-distearate, tallow ethylenediamine-dioleate, tallow ethylenediamine-ditallow aliphatic acid salt, tallow ethylenediamine-dihardened tallow aliphatic acid salt, tallow ethylenediamine-dicoconut aliphatic acid salt, tallow ethylenediamine-disoybean aliphatic acid salt; tallow propylene diamine-dilaurate, tallow propylenediamine-dimyristate, tallow propylenediamine-dipalmitate, tallow propylenediamine-distearate, tallow propylenediamine-dioleate, tallow propylenediamine-ditallow aliphatic acid salt, tallow propylenediamine-dihardened tallow aliphatic acid salt, tallow propylenediamine-dicoconut aliphatic acid salt, tallow propylenediamine-disoybean aliphatic acid salt; hardened tallow ethylenediamine-dilaurate, hardened tallow ethylenediamine-dimyristate, hardened tallow ethylenediamine-dipalmitate, hardened tallow ethylenediamine-distearate, hardened tallow ethylenediamine-dioleate, hardened tallow ethylenediamine-ditallow aliphatic acid salt, hardened tallow ethylenediamine-dihardened tallow aliphatic acid salt, hardened tallow ethylenediamine-dicoconut aliphatic acid salt, hardened tallow ethylenediamine-disoybean aliphatic acid salt; hardened tallow propylenediamine-dilaurate, hardened tallow propylenediamine-dimyristate, hardened tallow propyrenediamine-dipalmitate, hardened tallow propylenediamine-distearate, hardened tallow propylenediamine-dioleate, hardened tallow propylenediamine-ditallow aliphatic acid salt, hardened tallow propylenediamine-dihardened tallow aliphatic acid salt, hardened tallow propylenediamine-dicoconut aliphatic acid salt, hardened tallow propylenediamine-disoybean aliphatic acid salt; coconut ethylenediamine-dilaurate, coconut ethylenediamine-dimyristate, tallow ethylenediamine-dipalmitate, coconut ethylenediamine-distearate, coconut ethylenediamine-dioleate, coconut ethylenediamine-ditallow aliphatic acid salt, cococnut ethylenediamine-dihardened tallow aliphatic acid salt, coconut ethylenediamine-dicoconut aliphatic acid salt, coconut ethylenediamine-disoybean aliphatic acid salt; coconut propylenediamine-dilaurate, coconut propylenediamine-dimyristate, coconut propylenediamine-dipalmitate, coconut propylenediamine-distearate, coconut propylenediamine-dioleate, coconut propylenediamine-ditallow aliphatic acid salt, coconut propylenediamine-dihardened tallow aliphatic acid salt, coconut propylenediamine-dicoconut aliphatic acid salt, coconut propylenediamine-disoybean aliphatic acid salt; soybean ethylenediamine-dilaurate, soybean ethylenediamine-dimyristate, soybean ethylenediamine-dipalmitate, soybean ethylenediamine-distearate, soybean ethylenediamine-dioleate, soybean ethylenediamine-ditallow aliphatic acid salt, soybean ethylenediamine-dihardened tallow aliphatic acid salt, soybean ethylenediamine-dicoconut aliphatic acid salt, soybean ethylenediamine-disoybean aliphatic acid salt; soybean propylenediamine-dilaurate, soybean propylenediamine-dimyristate, soybean propylenediamine-dipalmitate, soybean propylenediamine-distearate, soybean propylenediamine-dioleate, soybean propylenediamine-ditallow aliphatic acid salt, soybean propylenediamine-dihardened tallow aliphatic acid salt, soybean propylenediamine-dicoconut aliphatic acid salt, soybean propylenediamine-disoybean aliphatic acid salt and a mixture thereof.
The component [III] which is an essential additive to be added to a base lubricating oil according to this invention is an aliphatic monoamine (F) represented by the following general formula (5)
R.sup.12 --NH.sub.2 ( 5)
wherein R 12 is a straight-chain or branched-chain alkyl or straight-chain alkenyl group having 6 to 22 carbon atoms.
The R 12 is exemplified by an alkyl group such as hexyl groups (including all isomeric group), heptyl groups (including all isomeric group), octyl groups (including all isomeric group), nonyl groups (including all isomeric group), decyl groups (including all isomeric group), undecyl groups (including all isomeric group), dodecyl groups (including all isomeric group), tridecyl groups (including all isomeric group), tetradecyl groups (including all isomeric group), pentadecyl groups (including all isomeric group), hexadecyl groups (including all isomeric group), heptadecyl groups (including all isomeric group), octadecyl groups (including all isomeric group), nonadecyl groups (including all isomeric group), eicosyl groups (including all isomeric group), heneicosyl groups (including all isomeric group) and docosyl groups (including all isomeric group); and an alkenyl group such as octenyl groups (including all isomeric group), nonenyl groups (including all isomeric group), decenyl groups (including all isomeric group), undecenyl groups (including all isomeric group), docenyl groups (including all isomeric group), tridecenyl groups (including all isomeric group), tetradecenyl groups (including all isomeric group), pentadecenyl groups (including all isomeric group), hexadecenyl groups (including all isomeric group), peptadecenyl groups (including all isomeric group), octadecenyl groups (including all isomeric group), nonadecenyl groups (including all isomeric group), eicosenyl groups (including all isomeric group), heneicosenyl groups (including all isomeric group) and docosenyl groups (including all isomeric group); and an aliphatic group derived from fats and oils such as tallow, hardened tallow, coconut oil and soybean oil.
From the standpoint of its excellency particularly in friction-reducing effect, the aliphatic monoamine (F) of the component [III] used in this invention is preferably a compound of the formula (5) wherein R 12 is a member selected from a straight-chain alkyl and a straight-chain alkenyl group having 8 to 18 carbon atoms. Preferable compounds as the aliphatic monoamine include octyl amine (capryl amine), decyl amine, dodecyl amine (lauryl amine), tetradecyl amine (mirystyl amine), hexadecyl amine (palmityl amine), octadecyl amine (stearyl amine), 9-octadecenyl amine (oleyl amine), or an aliphatic monoamine derived from flats and oils such as tallow, hardened tallow, coconut oil or soybean oil, and a mixture thereof.
The specific combinations of the components [I], [II] and [III ] in the hydraulic working oil compositions for a buffer according to this invention may be for example (A)+(C)+(F); (A)+(D)+(F); (A)+(E)+(F); (B)+(C)+(F); (B)+(D)+(F); and (B)+(E)+(F); or a mixture of two or more combinations selected from the above combination examples.
It is essential that the hydraulic working oil compositions for a buffer of this invention contain the components [I], [II] and [III] as the essential components, and at the same time it is important in this invention that the contents of these components [I], [II] and [III] are required to satisfy the following formulae (6), (7) and (8). Only when the contents of these components [I], [II] and [III] meet the requirements or the following formulae (6), (7) and (8), it is possible to obtain hydraulic working oil compositions for a buffer which exhibit very excellent durability (little degradation with the time of use) of friction-reducing effect and wear-preventing effect, and excellent storage stability:
W.sub.I =0.1-5.0 (6)
W.sub.I /(W.sub.II +W.sub.III)=1.5-20.0 (7)
W.sub.II /W.sub.III =0.2-2.0 (8)
wherein W I , W II and W III represent the contents of components [I], [II] and [III], respectively (these contents being each expressed in weight % based on the total weight of the composition).
As shown in the above formula (6), the lower limit of the content (weight %) of component [I] based on the total weight of the composition of this invention is 0.1, preferably 0.5. If the value of W I is less than 0.1, the durability of friction-reducing effect and wear-preventing effect will be unfavorably lowered. On the other hand, the upper limit of W I is 5.0, preferably 3.0. If the value of W I exceeds 5.0, the durability of wear-preventing effect will be unfavorably lowered.
Further, as shown in the above formula (7), the lower limit of the value of W I /(W II +W III ) (i.e. the lower limit of the value of W I , if the value of (W II +W III ) is assumed to be 1 in the formula of W I (W II +W III )) is 1.5, preferably 2.0. When the component [I] is not contained (i.e., W I =0) or when the value W I /(W II +W III )) is less than 1.5, the durability of friction-reducing effect will be poor and the storage stability will be unfavorably deteriorated. On the other hand, the upper limit of W I /(W II +W III ) is 20.0, preferably 15.0. If the value of W I /(W II +W III ) exceeds 20.0, the durability of friction-reducing effect and wear-preventing effect will be unfavorably lowered.
Further, as shown in the above formula (8), the lower limit of the value of W II +W III (i.e. the lower limit of the value of W II , if the value of W III is assumed to be 1 in the formula of W II /W III ) is 0.2, preferably 0.3. When the component [II] is not contained (i.e., W II =0) or when the value of W II /W III is less than 0.2, the durability of friction-reducing effect will be unfavorably lowered. On the other hand, the upper limit of W II /W III is 0.2, preferably 1.5. When the component [III] is not contained (i.e., W III =0) or the value of W II /W III exceeds 2.0, the storage stability will be unfavorably deteriorated.
As described above, although the hydraulic working oil composition of this invention having excellent performances can be obtained only by adding the components [I], [II] and [III] to the base lubricating oil, to further enhance the thus obtained hydraulic working oil composition in various performances, heretofore known additives for lubricating oils may be used singly or jointly in the above oil composition.
These additives include friction-reducing agents other than the components of the oil composition of this invention, such as an aliphatic alcohol, aliphatic acid, aliphatic amine and aliphatic amide; antioxidants such as phenol-, amine-, sulphur-, zinc dithiophosphate- and phenothiazine-based compounds; extreme-pressure agents such as sulfurized fats and oils, sulfides and zinc dithiophosphate; rust preventives such as petroleum sulfonates and dinonylnaphthalene sulfonate; metal deactivators such as benzotriazole and thiadiazole; metallic detergents such as alkaline earth metal sulfonates, alkaline earth metal phenates, alkaline earth metal salicylates and alkaline earth metal phosphonates; ashless dispersants such as succinic imide, succinic esters and benzyl amine; antifoaming agents such as methylsilicone and fluorosilicone; viscosity index improvers such as polymethacrylate, polyisobutylene and polystyrene; and pour point depressants.
Although the amount of these additives added may be arbitrary, the contents of the antifoaming agent, the viscosity index improver, the metal inactivator and each of the other additives in the oil composition are ordinarily 0.0005-1% by weight, 1-30% by weight, 0.005-1% by weight and 0.1-15% by weight in this order, based on the total amount of the oil composition, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention will be better understood by the non-limitative Examples and Comparative Examples.
EXAMPLES 1 TO 8, AND COMPARATIVE EXAMPLES 1 TO 8
In each of the Examples, the ingredients shown in Table 1 were mixed together and the resulting mixture was heated to 50° C. under stirring for two hours thereby to prepare a hydraulic working oil composition of this invention (Examples 1-8). The oil compositions of this invention so prepared were subjected to a duration test using an actual device to evaluate them for their friction-reducing effect and wear-preventing effect. The thus obtained results are shown in Table 1.
Additionally, the storage stability of these oil compositions was evaluated according to a storage stability test as shown below. The results of the evaluation are also shown in Table 1.
For the purpose of comparison, a composition without containing the Component [III] according to this invention (Comparative Example 1), a composition without containing the component [II] according to this invention (Comparative Example 2) and compositions containing all of the components [I] , [II] and [III] according to this invention in the ratios falling outside the ranges as defined by the present invention (Comparative Examples 3 to 8), were prepared and evaluated under the same conditions as in the Examples of this invention. The results of the evaluation are also shown in Table 2.
Duration Test Using Actual Device
Using two commercially available strut-type shock absorbers, duration tests were made under the following conditions until the end of two million frequency of oscillation application.
Temperature of a test oil: 80° C.
Amount of a test oil used: 330 ml/one shock absorber
Lateral load: 200 kgf
Entire amplitude of oscillation applied: 50 mm
Velocity of oscillation applied: 0.5 m/s
Friction-reducing effects
The shock absorbers were measured for their frictional coefficients at their frictional surfaces at the time of oscillation application frequency of zero (at the initial stage of the duration test) and at the time of oscillation application frequency of two millions (at the time of completion of the duration test), respectively. The frictional coefficients so measured are as shown in Table 1.
Wear-preventing effects
After the completion of the duration test, the shock absorbers were disassembled to visually evaluate the surface state of their friction surfaces (cylinders, pistons, rods and oil seals of the shock absorbers) with the results being as shown in Table 1. The degrees of the wear-preventing effects are represented in terms of six numerals 0-5 (numeral 5 being the best).
______________________________________Appearance of Friction SurfaceRating Cylinder Piston Rod______________________________________5 Nearly brand-new Nearly brand-new (lustrous)4 Slightly discolored Slightly discolored3 Greatly discolored Greatly discolored2 Longitudinally flawed Longitudinally flawed1 Abnormally worn Abnormally worn______________________________________
Storage stability test
Each sample oil weighing 45 g was taken in a 50 ml glass beaker, after which the beaker was lidded with an aluminum foil. In one ease, a part of the lidded beakers with the sample oil therein were then kept in a thermostat at 140° C. for 96 hours (1), and, in another ease, the rest of the lidded beakers were then stored at 23° C. (room temperature) for 90 days (2). Then, the condition of each sample oil was visually evaluated. The results are shown in Table 1. The criteria for evaluating each sample oil for its storage stability are expressed in three grades 1, 2 and 3 (numeral 3 being the best).
______________________________________Rating Appearance of Sample Oil______________________________________3 Transparent (no cloudiness, no sediment)2 Occurrence of cloudiness within oil and on the surface thereof1 Occurrence of sediment within oil and on the bottom of beaker______________________________________
In these Examples and Comparative Examples, the following components are used.
Lubricating oil as base oil
A: paraffin-based highly solvent-refined mineral oil (kinematic viscosity 10.2 mm 2 /s at 40° C.).
Component [I]
A: dioleyl acid phosphate
B: dioleyl hydrogen phosphite
Component [II]
A: ethyleneoxide adduct of oleylamine R'-N.paren open-st.C 2 H 4 -OH) 2 (R': olcyl group)
B: oleyl ethylene diamine
C: tallow amine dioleate
Component [III]
A: oleyl amine
B: stearyl amine
As is apparent from the results of the performance evaluation tests shown in Table 1, the hydraulic working oil compositions (Examples 1-8) of the present invention are excellent in friction-reducing effects at the initial stage of the duration test and exhibit less degradation of their friction-reducing performances with the lapse of time. In addition to this, the oil compositions of the present invention exhibit less wear of the friction surfaces even at the end of the duration test and are excellent not only in wear-preventing effects but also in storage stability.
In contrast, the compositions of Comparative Examples 3 to 8, the composition containing none of the component [III] (Comparative Example 1), the composition containing none of the component [II] (Comparative Example 2), and compositions containing all of the components [I], [II] and [III] in the ratios falling outside the range as defined by the present invention (Comparative Examples 3 to 8), are inferior to those of the Examples of this invention in durability of the friction-reducing effect, wear-preventing effect and storage stability.
Thus, the foregoing demonstrates the excellency of the compositions of this invention over the comparative ones.
Effects of this Invention
As is apparent from the foregoing, the hydraulic working oil compositions of this invention are excellent in durability of friction-reducing effects at the initial stage of duration and exhibit less degradation of their friction-reducing performances with the lapse of Lime. In addition to this, the hydraulic working oil compositions of this invention are excellent not only in wear-preventing effects and storage stability but also in applicability to Teflon resin-impregnated bush members.
TABLE 1__________________________________________________________________________ Ex. 1 Ex. 2 Ex. 3 Ex. 4__________________________________________________________________________composition base oil A A A A(wt. %) [94.7] [94.7] [94.7] [94.7] component A B A A [I] [1.0] [1.0] [1.0] [1.0] component A A B C [II] [0.1] [0.1] [0.1] [0.1] component A A A A [III] [0.1] [0.1] [0.1] [0.1] W.sub.I 1.0 1.0 1.0 1.0 W.sub.I /(W.sub.II + W.sub.III) 5.0 5.0 5.0 5.0 W.sub.II /W.sub.III 1.0 1.0 1.0 1.0 2,6-di-t-butyl-p-cresol [0.6] [0.6] [0.6] [0.6] polymethacrylate [3.5] [3.5] [3.5] [3.5]performance real machine friction- 1 friction coefficient 0.101 0.102 0.101 0.102evaluation performance reducing (at initial stage) effect 2 friction coefficient 0.133 0.133 0.133 0.132 (at 2 million times) 2/1 1.32 1.30 1.32 1.29 wear- surface states of preventing friction site*1 effect cylinder 5 5 5 5 piston rod 5 5 5 5 storage stability 140° C. × 96 hours 3 3 3 3 23° C. × 90 days 3 3 3 3__________________________________________________________________________ Ex. 5 Ex. 6 Ex. 7 Ex. 8__________________________________________________________________________composition base oil A A A A(wt. %) [94.7] [94.7] [94.7] [95.2] component A A A A [I] [1.0] [1.0] [1.0] [0.5] component A A A A [II] [0.1] [0.05] [0.12] [0.1] component B A A A [III] [0.1] [0.15] [0.08] [0.1] W.sub.I 1.0 1.0 1.0 0.5 W.sub.I /(W.sub.II + W.sub.III) 5.0 5.0 5.0 2.5 W.sub.II /W.sub.III 1.0 0.3 1.5 1.0 2,6-di-t-butyl-p-cresol [0.6] [0.6] [0.6] [0.6] polymethacrylate [3.5] [3.5] [3.5] [3.5]performance real machine friction- 1 friction coefficient 0.102 0.102 0.102 0.101evaluation performance reducing (at initial stage) effect 2 friction coefficient 0.131 0.134 0.133 0.132 (at 2 million times) 2/1 1.29 1.31 1.30 1.31 wear- surface states of preventing friction site*1 effect cylinder 5 5 5 5 piston rod 5 5 5 5 storage stability 140° C. × 96 hours 3 3 3 3 23° C. × 90 days 3 3 3 3__________________________________________________________________________ *1: mean value of two shock absorbers (Struttype)
TABLE 2__________________________________________________________________________ Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex. 4__________________________________________________________________________composition base oil A A A A(wt. %) [94.7] [94.7] [94.86] [95.62] component A A A A [I] [1.0] [1.0] [1.0] [0.08] component A -- A A [II] [0.2] [0.02] [0.1] component -- A A A [III] [0.2] [0.02] [0.1] W.sub.I 1.0 1.0 1.0 0.08 W.sub.I /(W.sub.II + W.sub.III) 5.0 5.0 25.0 0.4 W.sub.II /W.sub.III -- 0 1.0 1.0 2,6-di-t-butyl-p-cresol [0.6] [0.6] [0.6] [0.6] polymethacrylate [3.5] [3.5] [3.5] [3.5]performance real machine friction- 1 friction coefficient 0.104 0.103 0.103 0.102evaluation performance reducing (at initial stage) effect 2 friction coefficient 0.142 0.215 0.246 0.217 (at 2 million times) 2/1 1.37 2.09 2.39 2.13 wear- surface states of preventing friction site*1 effect cylinder 5 5 3 2 piston rod 5 5 3 3 storage stability 140° C. × 96 hours 1 2 3 3 23° C. × 90 days 2 1 3 3__________________________________________________________________________ Comp. Comp. Comp. Comp. Ex. 5 Ex. 6 Ex. 7 Ex. 8__________________________________________________________________________composition base oil A A A A(wt. %) [92.9] [94.7] [94.7] [90.2] component A A A A [I] [1.0] [1.0] [1.0] [5.5] component A A A A [II] [1.0] [0.03] [0.17] [0.1] component A A A A [III] [1.0] [0.17] [0.03] [0.1] W.sub.I 1.0 1.0 1.0 5.5 W.sub.I /(W.sub.II + W.sub.III) 0.5 5.0 5.0 27.5 W.sub.II /W.sub.III 1.0 0.18 5.7 1.0 2,6-di-t-butyl-p-cresol [0.6] [0.6] [0.6] [0.6] polymethacrylate [3.5] [3.5] [3.5] [3.5]performance real machine friction- 1 friction coefficient 0.104 0.102 0.102 0.130evaluation performance reducing (at initial stage) effect 2 friction coefficient 0.152 0.208 0.140 0.206 (at 2 million times) 2/1 1.46 2.04 1.37 2.00 wear- surface states of preventing friction site*1 effect cylinder 5 3 5 2 piston rod 5 3 5 2 storage stability 140° C. × 96 hours 1 3 1 3 23° C. × 90 days 2 3 2 3__________________________________________________________________________ *1: mean value of two shock absorbers (Struttype) | A hydraulic working oil composition for buffers which comprises:
a lubricating oil as a base oil,
[I] at least one phosphorus-containing compound selected from the group consisting of a phosphoric acid having a specific structure and a phosphorous acid ester having a specific structure, and
[II] at least one nitrogen-containing compound selected from the group consisting of an alkyleneoxide adduct of an aliphatic monoamine having a specific structure, an aliphatic polyamine having a specific structure and a salt of the above aliphatic polyamine having a specific structure, and
[III] an aliphatic monoamine having a specific structure, the components [I] to [III] being essential components added to said base oil in a predetermined ratio; and a process for lubricating buffers with said hydraulic working oil composition. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None
BACKGROUND OF THE INVENTION
[0003] This invention relates to a counter-flow asphalt plant used to produce a variety of asphalt compositions. More specifically, this invention relates to a counter-flow asphalt plant having a recycle asphalt (RAP) feed to the combustion zone to produce high percentage RAP asphalt products within a two stage mixing zone to improve production rates with greater economy and efficiency of plant design and operation.
[0004] Several techniques and numerous equipment arrangements for the preparation of asphaltic compositions, also referred by the trade as “hotmix” or “HMA”, are known from the prior art. Particularly relevant to the present invention is the continuous production of asphalt compositions in a drum mixer asphalt plant. Typically, water-laden virgin aggregates are dried and heated within a rotating, open-ended drum mixer through radiant, convective and conductive heat transfer from a stream of hot gases produced by a burner flame. As the heated virgin aggregate flows through the drum mixer, it is combined with liquid asphalt and mineral binder to produce an asphaltic composition as the desired end-product. Optionally, prior to mixing the virgin aggregate and liquid asphalt, reclaimed or recycled asphalt pavement (RAP) may be added once it is has been crushed or ground to a suitable size. The RAP is typically mixed with the heated virgin aggregate in the drum mixer at a point prior to adding the liquid asphalt and mineral fines.
[0005] The asphalt industry has traditionally faced many environmental challenges. The drum mixer characteristically generates, as by-products, a gaseous hydrocarbon emission (known as blue smoke), various nitrogen oxides (NO x ) and sticky dust particles covered with asphalt. Early asphalt plants exposed the liquid asphalt or RAP material to excessive temperatures within the drum mixer or put the materials in close proximity with the burner flame which caused serious product degradation. Health and safety hazards resulted from the substantial air pollution control problems due to the blue-smoke produced when hydrocarbon constituents in the asphalt are driven off and released into the atmosphere. The exhaust gases of the asphalt plant are fed to air pollution control equipment, typically a baghouse. Within the baghouse, the blue-smoke condenses on the filter bags and the asphalt-covered dust particles stick to and plug-up the filter bags, thereby presenting a serious fire hazard and reducing filter efficiency and useful life. Significant investments and efforts were previously made by the industry in attempting to control blue-smoke emissions attributed to hydrocarbon volatile gases and particulates from both the liquid asphalt and recycle material.
[0006] The earlier environmental problems were further exacerbated by the processing technique standard in the industry which required the asphalt ingredients with the drum mixer to flow in the same direction (i.e., co-current flow) as the hot gases for heating and drying the aggregate. Thus, the asphalt component of recycle material and liquid asphalt itself came in direct contact with the hot gas stream and, in some instances, even the burner flame itself.
[0007] Many of the earlier problems experienced by asphalt plants were solved with the development of modern day counter-flow technology as disclosed in my earlier patent Hawkins U.S. Pat. No. 4,787,938 which is incorporated herein by reference and which was first commercially introduced by Standard Havens, Inc. in 1986. The asphalt industry began to standardize on the counter-flow processing technique in which the ingredients of the asphaltic composition and the hot gas stream flow through a single, rotating drum mixer in opposite directions. Combustion equipment extends into the drum mixer to generate the hot gas stream at an intermediate point within the drum mixer. Accordingly, the drum mixer includes three zones. From the end of the drum where the virgin aggregate feeds, the three zones include a drying/heating zone to dry and heat virgin aggregate, a combustion zone to generate a hot gas stream for the drying/heating zone, and a mixing zone to mix hot aggregate, recycle material and liquid asphalt to produce an asphaltic composition for discharge from the lower end of the drum mixer.
[0008] Not only did the counter-flow process with its three zones vastly improve heat transfer characteristics, more importantly it provided a process in which the liquid asphalt and recycle material were isolated from the burner flame and the hot gas stream generated by the combustion equipment. Counter-flow operation represented a solution to the vexing problem of blue-smoke and all the health and safety hazards associated with blue-smoke.
[0009] A more complete understanding of the early equipment and processing techniques used by the asphalt industry can be found in the extensive listing of prior art patents and printed publications contained in my earlier patents Hawkins U.S. Pat. No. 5,364,182 issued Nov. 15, 1994, Hawkins U.S. Pat. No. 5,470,146 issued Nov. 28, 1995, and Hawkins U.S. Pat. No. 5,664,881 issued Sep. 9, 1997. Indeed, as a result of my first patent Hawkins U.S. Pat. No. 4,787,938 becoming involved in protracted litigation, the prior art collection cited in the foregoing patents is thought to be a thorough and exhaustive bibliographic listing of asphalt technology and such prior art is specifically incorporated herein by reference.
[0010] With many of the health and safety issues associated with asphalt production solved by the advent of counter-flow technology, contemporaneous attention has now shifted to operational inefficiencies which are manifest as excessive design and production costs and poor economy of operation from excess energy consumption.
[0011] Experience has shown that the environmentally desirable use of a recycled material (RAP) in asphalt production comes with disadvantageous tradeoffs in energy consumption. The most energy efficient plant operation is achieved when no RAP is added. In such circumstances, for example, all virgin aggregate is introduced in one end of the dryer and flows as a falling curtain or veil of material in counter-current heat exchange with hot gases generated at the opposite end of the dryer. The shell temperature is characteristically about 500° F. and the exhaust gas is about 225° F. which is within the normal operating temperature for the baghouse used to filter the exhaust gas of particulate matter. The temperature of the exhaust gas stream is determined by the design of the dryer, but must be kept above its dew point to prevent moisture from condensing in the exhaust ductwork and especially in the baghouse itself. A temperature of 225° F. is sufficient, but since varying conditions during operation can cause relatively large temperature swings, most operations are controlled to keep exhaust temperatures in the range of 250° F. to 275° F.
[0012] The addition of RAP material has a significant effect on operating temperatures of the process. Conventional wisdom has taught that the RAP cannot be directly dried without burning the liquid asphalt and causing hydrocarbon smoke emissions. Accordingly, it has previously been dried indirectly by superheating the virgin aggregates and then mixing the superheated aggregates with the RAP to achieve a blended mixture temperature. This results in much higher exhaust gas temperatures and a resulting loss in fuel efficiency. Accordingly, 20 TO 40% RAP feeds (that is, operations wherein RAP makes up 20 to 40% of the final asphalt composition) have been close to the upper end of the range heretofore workable in modern counter-flow asphalt plants. Although a 50% RAP feed has been achievable, it has been at the cost of high energy and reduced equipment life. Consequently, an upper limit of approximately 40% RAP has been a realistic upper limit for the majority of asphalt plants. The operating conditions necessary are illustrative of the problems. If 50% RAP is introduced midstream in the process, then only 50% virgin aggregates are used. This means that only half the material is present, as compared to the 100% virgin aggregate production, to be heated and only half the veiling of material in the drying section of the drum occurs which yields poor heat transfer characteristics. Under such circumstances, the combustion zone temperature must be elevated significantly to superheat the virgin aggregate. This, in turn, causes the shell temperature of the drum to range from 750-800° F. and the exhaust gas temperature to increase to about 375° F. The exhaust gas temperature will now exceed the upper limit for a baghouse using polyester bags which have an upper service of about 275° F. Accordingly, more costly filter bags constructed of less heat sensitive material such as NOMEX (an aramid fiber marketed by DuPont) have to be installed in the baghouse whenever higher RAP feed operations are contemplated. Moreover, any time the combustion zone temperature rises to about 2800° F. or greater then the production of various nitrogen oxides (NO x ) as a product of combustion becomes a problem.
[0013] The foregoing problems associated with processing high percentage RAP are further exacerbated by the moisture content of the RAP itself. The superheat of the virgin aggregate must be sufficient to not only heat the RAP material to an appropriate mix temperature, but also supply the necessary heat to vaporize the moisture content of the RAP.
[0014] Accordingly, modern asphalt plants characteristically introduce RAP in one of two ways. Using the first method, RAP is introduced directly into an isolated mixing zone where all heat transferred to the RAP must necessarily come from superheated virgin aggregate. Using the second method, the RAP is introduced into the combustion zone but shielded from direct radiant heat by an inner shell or by special flighting to preheat the RAP by convective and conductive heat transfer before it is delivered to an isolated mixing zone.
[0015] Asphalt plants constructed like Hawkins U.S. Pat. No. 4,787,938 and other counter-flow drum mixers that followed utilized an isolated mixing zone to prevent blue smoke. For the most part they did so successfully, although not completely. However, unwanted consequences resulted from this processing technique, particularly as the use of RAP addition to asphalt compositions increased. By isolating the mixing zone from the gas stream, they create a dead zone in which any blue smoke and moisture vapor that forms within the mixing zone is not adequately evacuated. Though most of the blue smoke is eliminated by shielding the liquid asphalt exposure to the radiant heat of the flame and from exposure to the hot exhaust gas stream, smoke is generated in the mixing zone when the liquid asphalt comes in contact with the hot aggregate. This is especially true when the aggregate is superheated, as in high percentage recycle operations. Since the blue smoke is generated in a dead zone, it tends to flow with the exiting production material, and exit the drum mixer at the material discharge port. In most cases this is overlooked by the environmental agencies because it is the exhaust gas stack, and not the material discharge port, that they are charged with monitoring and enforcing pollution regulations. Still, it is likely only a matter of time until the focus of environmental protection is trained on the discharge area. Some areas of the country are already requiring blue smoke control systems for the discharge and loadout areas of an asphalt plant.
[0016] A similar problem exits with the evacuation of moisture vapor from the dead zone of an isolated mixing chamber. This is particularly true when, as in most cases, the cold, wet recycle material is introduced into the mixing zone where the moisture content is vaporized by the superheated aggregate. The resulting steam explosion from the rapidly vaporized recycle moisture causes steam and dust to be forced from the drum mixer, generally at the recycle feed collar and to some extent at the drum discharge port.
[0017] A need remains in the industry for an improved counter-flow asphalt plant design capable of utilizing high percentage RAP mixes and for operating techniques to address the problems and drawbacks heretofore experienced with modern counter-flow production. The primary objective of this invention is to meet this need.
BRIEF SUMMARY OF THE INVENTION
[0018] More specifically, an object of the invention is to provide a counter-flow asphalt plant capable of routinely using high percentage RAP mixes (e.g., up to 50% RAP) without emitting excessive blue smoke or without excessive energy requirements.
[0019] Another object of the invention is to provide a counter-flow asphalt plant capable of effectively evacuating blue smoke and steam from the mixing zone in an environmentally friendly manner even when processing high percentage RAP mixes.
[0020] Another object of the invention is to provide a counter-flow asphalt plant capable of processing up to 50% RAP mixes with extended equipment life by eliminating the need to superheat virgin aggregates with the associated temperature elevation of the processing equipment.
[0021] An alternative object of the invention is to provide a counter-flow asphalt plant capable of processing RAP mixes greater than 50% by utilizing superheating techniques together with the processing techniques which are the subject of this invention.
[0022] Another object of the invention is to provide counter-flow drum mixer equipment and method of operation for retrofitting existing asphalt plants to increase production capacity by reducing the total volume and temperature of the combustion gases present in the equipment for a given production rate.
[0023] A corollary object of the invention is to provide counter-flow drum mixer equipment and method of operation of the character previously described for retrofitting existing asphalt plants to increase production capacity by as much as 20%.
[0024] An additional object of the invention is to provide counter-flow drum mixer equipment of a reduced size for a given production rate for savings in original equipment costs, as well as savings in operating costs, by reducing the total volume and temperature of the combustion gases necessary to achieve a given production rate in a conventional counter-flow plant.
[0025] A corollary object of the invention is to provide counter-flow drum mixer equipment and method of operation of the character previously described that reduces by as much as 20% the size of the equipment required to produce a given volume of product.
[0026] A further object of the invention is to provide a counter-flow drum mixer to permit RAP material to be introduced directly into the combustion zone to take full advantage of radiant, convective and conductive heat transfer.
[0027] Yet another object of the invention is to provide counter-flow drum mixer and method of operation for reducing NO x emissions for processing techniques utilizing both virgin material mixes and RAP with virgin material mixes.
[0028] An additional object of the invention is to provide counter-flow drum mixer and method of operation which both reduces in size and operates more economically the air handling equipment and dust collection system required for asphalt production.
[0029] Another object of the invention is to provide counter-flow drum mixer and method of operation for which the exhaust gas temperatures are substantially lower than in conventional systems (225 F. average vs. 375 F. average in a typical 50% recycle plant) to permit the use of polyester filters in the dust collection system for a savings of 80% in filter cost over conventional systems.
[0030] A further object of the invention is to provide a counter-flow asphalt plant of the character described having improved efficiency of operation and production consistency of finished product conforming to specifications.
[0031] An additional object of the invention is to provide a counter-flow asphalt plant of the character described having more precise control over operating parameters to achieve a uniform end-product and more precise control over energy requirements for improved economic operation.
[0032] An added object of the invention is to provide a counter-flow asphalt plant of the character described which meets or exceeds modern day environmental standards.
[0033] A further object of the invention is to provide a counter-flow asphalt plant of the character described which is both safe and economical in operation. Efficient operation results in improved fuel consumption and in reduced air pollution emissions.
[0034] Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the detailed description of the drawings.
[0035] In summary, a counter-flow drum mixer asphalt plant equipped with a secondary feeder for introducing RAP to direct radiant heat of the combustion zone. Heated virgin aggregate and RAP in the combustion zone are delivered through a transition piece to a first stage of the mixing zone where liquid asphalt is combined with the materials and secondary combustion air flows through the first stage to evacuate blue smoke and steam back to the combustion zone. The second stage of the mixing zone is substantially isolated from secondary combustion air flow where dust and mineral fines are introduced and mixed to complete the asphalt product discharged from the mixing zone. Alternative constructions of the mixing zone are disclosed to provide the first and second stages having such characteristics, as well as options for both the passive and active control of the secondary combustion air. An optional secondary burner in the exhaust housing elevates the temperature of the exhaust gas above its dew point temperature before delivery to the baghouse.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0036] In the following description of the drawings, in which like reference numerals are employed to indicate like parts in the various views:
[0037] [0037]FIG. 1 is a side sectional view of a prior art counter-flow asphalt plant in order to compare and contrast the teachings of this invention;
[0038] [0038]FIG. 2 is a side view of a single drum, counter-flow asphalt plant constructed in accordance with a first preferred embodiment of the invention;
[0039] [0039]FIG. 3 is a side sectional view of a counter-flow asphalt plant similar to FIG. 2 to better illustrate the details of construction and pertinent operational features of the equipment;
[0040] [0040]FIG. 4 is an end sectional view of a portion of the exhaust ductwork, the associated exhaust gas heater and a schematic illustration of the temperature control system as taken from the right hand end of FIG. 3;
[0041] [0041]FIG. 5 is an enlarged side view of the combustion zone recycle feed assembly for use with the asphalt equipment disclosed herein;
[0042] [0042]FIG. 6 is an enlarged side sectional view of the combustion zone recycle feed assembly shown in FIG. 5 to better illustrate the internal details of construction;
[0043] [0043]FIG. 7 is an enlarged end sectional view taken along line 7 - 7 of FIG. 3 in the direction of the arrows to better illustrate the details of the combustion zone flighting in relation to the internal details of the feed collar;
[0044] [0044]FIG. 8 is an enlarged fragmentary view taken along line 8 - 8 of FIG. 7 in the direction of the arrows to show the support brackets of the combustion zone flighting;
[0045] [0045]FIG. 9 is an enlarged end sectional view taken along line 9 - 9 of FIG. 3 in the direction of the arrows to better illustrate the details of the venture cone and support structure at the transition region of the combustion zone to the mixing zone;
[0046] [0046]FIG. 12 is a side sectional view of a single drum, counter-flow asphalt plant constructed in accordance with a third preferred embodiment of the invention with a modified mixing zone and aspirated secondary combustion air; and
[0047] [0047]FIG. 13 is a side sectional view of a single drum, counter-flow asphalt plant constructed in accordance with a fourth preferred embodiment of the invention similar to the asphalt plant of FIG. 12 but with provisions for total control of both primary and secondary combustion air.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Referring now to the drawings in greater detail, attention is first directed a modern day counter-flow asphalt plant as shown in the prior art illustration of FIG. 1 for the purpose of subsequently comparing and contrasting the structure and operation of an asphalt plant constructed in accordance with this invention as illustrated in FIGS. 2-13. The prior art asphalt plant of FIG. 1 is shown and described in greater detail in Hawkins U.S. Pat. No. 4,787,938 incorporated herein by reference.
[0049] The prior art counter-flow plant includes a substantially horizontal, single drum mixer 10 carried by a ground engaging support frame 12 at a slight angle of declination, typically about 5 degrees. Mounted on the frame 12 are two pairs of large, motor driven rollers 14 which supportingly receive trunnion rings 16 secured to the exterior surface of the drum mixer 10 . Thus, rotation of the drive rollers 14 engaging the trunnion rings 16 causes the drum mixer 10 to be rotated about its central longitudinal axis in the direction of the rotational arrow 17 .
[0050] Located at the inlet or upstream end of the drum mixer 10 is an aggregate feeder to deliver aggregate to the interior of the drum mixer 10 from a storage hopper or stockpile (not shown). The inlet end of the drum mixer 10 is closed by a flanged exhaust port 20 leading to conventional air pollution control equipment (not shown), such as a baghouse, to remove particulates from the gas stream.
[0051] Located at the outlet end of the drum mixer 10 is a discharge housing 22 to direct asphaltic composition from the drum mixer 10 to a material conveyor (not shown) for delivery of the final product to a storage bin or transporting vehicle.
[0052] A combustion assembly 24 extends through the discharge housing 22 and into the drum mixer 10 to deliver fuel, primary air from a blower 26 and induced secondary air through an open annulus to a burner head 28 . In the combustion zone beginning at the burner head 28 there is generated a hot gas stream which flows through the drying zone of the drum mixer 10 . Within the drying zone are fixed various types of dryer flights or paddles 29 for the alternative purposes of lifting, tumbling, cascading, veiling, mixing, and moving aggregate within the drum mixer 10 to facilitate the drying and heating of the aggregate therein. Within the combustion zone, on the other hand, the combustion flights 30 are designed primarily to mix and move the aggregate through this section of the drum mixer rather than cause material to cascade or veil through the flame envelope.
[0053] Downstream of the burner head 28 in a modem, prior art asphalt plant begins the mixing zone. Within this region is typically located the recycle feed assembly 34 by which recycle asphalt material may be introduced into the drum mixer 10 . A stationary box channel 35 encircles the exterior surface of the drum mixer 10 and includes a feed hopper 36 providing access to the interior of the box channel 35 . Bolted to the side walls of the box channel 35 are flexible seals 37 to permit rotation of the drum mixer 10 within the encircling box channel 35 . Secured to the outer wall of the drum mixer 10 and projecting into the space defined by the box channel 35 are a plurality of scoops 38 radially spaced around the drum mixer 10 . At the bottom of each scoop 38 is a scoop opening 40 through the wall of the drum mixer 10 to provide access to the interior of drum mixer 10 . Thus, recycle asphalt material may be delivered by conveyor (not shown) through the feed hopper 36 , into the box channel 35 and subsequently introduced into the interior of the drum mixer 10 through the scoop openings 40 .
[0054] Mounted on the interior of the drum mixer 10 and within the mixing zone are staggered rows of sawtooth mixer flighting 42 to mix and stir material within the annulus of the drum mixer 10 and combustion assembly 24 . A conveyer or screw auger 44 extends into the drum mixer 10 for feeding binder material or mineral “fines” to the mixing zone. Likewise extending into the drum mixer 10 is an injection tube 46 for spraying liquid asphalt into the mixing zone. At the end of the mixing zone is located the discharge housing 22 as previously discussed through which the asphaltic product is discharged.
[0055] With the foregoing background in mind, attention is now directed to the counter-flow asphalt plant constructed in accordance with a first preferred embodiment of this invention as illustrated in FIGS. 2-10. As an overview, it should be noted that the inventive features taught herein may be adapted to a variety of asphalt plant equipment configurations. FIGS. 11-13 illustrate modifications of the mixing zone in accordance with the teachings of this invention.
[0056] Turning then to the asphalt plant configuration shown in FIGS. 2-4, the counter-flow plant includes a substantially horizontal, single cylindrical drum 50 carried by a ground engaging support frame 52 at a slight angle of declination, typically about 5 degrees. Mounted on the frame 52 are two pairs of large, motor driven rollers 54 which supportingly receive trunnion rings 56 secured to the exterior surface of the drum 50 . Thus, rotation of the drive rollers 54 engaging the trunnion rings 56 causes the drum 50 to be rotated about its central longitudinal axis.
[0057] Located at the inlet or upstream end of the drum 50 is an aggregate feeder 58 to deliver aggregate to the interior of the drum 50 from a storage hopper or stockpile (not shown). The inlet end of the drum 50 is closed by a flanged exhaust port 59 connected, as is schematically illustrated in FIG. 3, to ductwork 60 leading to conventional air pollution control equipment 61 , such as a baghouse, to remove particulates from the exhaust gas stream.
[0058] Located at the outlet end of the drum 50 is a discharge housing 62 to direct asphaltic composition from the drum 50 to a material conveyor (not shown) for delivery of the final product to a storage bin or transporting vehicle.
[0059] A combustion assembly 64 extends through the discharge housing 62 and into the drum 50 to deliver fuel through fuel line 65 and primary air from a blower 66 to a burner head 68 . Combustion of the air and fuel within the combustion zone of the drum 50 which generally extends from the burner head 68 to the end of the flame envelope 69 generates a hot gas stream which flows through the drying zone of the drum 50 . Within the drying zone, material flights 70 are secured to the interior surface of the drum 50 to lift, tumble, cascade, veil, mix, and release aggregate material within the drum 50 to create a substantially continuous veil or curtain of falling material through which the hot gas stream passes in counter current flow to facilitate the drying and heating of the aggregate.
[0060] Conventional wisdom of asphalt plant design and operation positions the recycle feed downstream of the burner head as illustrated in FIG. 1 in order to deliver the RAP to the isolated mixing zone. Even if the recycle feed is positioned ahead of the burner, prior art asphalt plants add the RAP to an inner shell or with special flighting that shield the recycle material from the flame envelope. After preheating in this manner, the RAP is then delivered to the isolated mixing zone. The present design departs significantly from conventional wisdom in two important ways. First, the recycle feed assembly 72 is located upstream from the burner head 68 and intermediate the ends of the combustion zone, and secondly, the recycle material is introduced and exposed directly to the flame envelope within the combustion zone.
[0061] The details of construction of the recycle feed assembly are shown in FIGS. 5-7. A stationary box channel 75 is supported by legs 75 a to encircle the exterior surface of the drum 50 . A feed hopper 76 provides access to the interior of the box channel 75 . Bolted to the side walls of the box channel 75 are flexible seals 77 to permit rotation of the drum 50 within the encircling box channel 75 . Thus, for example, recycle asphalt material may be delivered by conveyor (not shown) through the feed hopper 76 , into the box channel 75 and subsequently introduced into the interior of the drum 50 through scoop openings 78 in the drum shell.
[0062] Within the combustion zone are mounted a plurality of combustion flights that are designated generally by the numeral 80 . In contradiction to the teachings of the prior art, the combustion flights are constructed and arranged to deliver the recycle material into the combustion zone for direct exposure to the radiant heat of the flame envelope. Details of the combustion flighting is shown in FIGS. 6-8.
[0063] Referring first to FIG. 6, the plurality of circumferential openings 78 through the shell of the drum are registered with the box channel 75 . Scoop plates 82 are secured exteriorly of the drum shell 50 to frame three sides of each such opening 78 to direct material falling through the feed hopper 76 from the interior of the box channel 75 through an opening 78 into the interior of the drum shell 50 . Note that a set of scoop plates 82 framing any opening 78 form a mouth which is open in the direction of rotation of the drum 50 as indicated by the arrow 84 (FIG. 7).
[0064] Secured to the interior surface of the drum shell 50 in the combustion zone, substantially parallel to the rotational axis of the drum, are the combustion flights 80 . Each combustion flight 80 includes an elongate flighting web 88 which has an angled leading lip 88 a bent with respect to the main body portion 88 b , and an angled trailing lip 88 c directed interiorly of the drum 50 from the main body portion 88 b . The leading lip 88 a of each flighting web 88 is connected to the interior surface of the drum 50 . As best shown in FIG. 8, the trailing lip 88 c of one flighting web 88 is held apart from the nearest adjacent flighting web 88 by a plurality of clip brackets 90 spaced longitudinally along the length of the flighting web 88 . For each such clip bracket 90 , a pin 92 interconnects the trailing lip 88 c to the clip bracket 90 and then to the main body portion 88 b of the adjacent flighting web 88 . Thus, the trailing lip 88 c of one flighting web 88 overlies the leading lip 88 a of the next adjacent flighting web 88 and is held apart by the clip brackets 90 and pins 92 to provide an elongate slot opening between successive webs 80 .
[0065] Accordingly, as illustrated by the material flow arrows of FIG. 7, recycle materials delivered through the feed hopper 76 are directed by the scoop plates 82 through the openings 78 in the drum shell 50 , then through the slots formed between successive combustion flighting webs 88 and into the combustion zone for direct exposure to radiant heat of the flame envelope. Since the RAP experiences radiant, convective and conductive heat transfer, it is important to limit the residence time of the RAP within the combustion zone. For this reason, the distance between the recycle feed assembly 72 and the mixing zone is limited to a range of 2 to 8 feet, and preferably falls in the range of 3 to 5 feet. Any blue smoke generated as a result of operation in this manner can be incinerated in the flame envelope 69 .
[0066] Downstream of the burner head 68 is the mixing zone within the drum 50 which is separated from the combustion zone by a transition member as shown in FIG. 9 and designated generally by the numeral 94 . The transition piece 94 includes an annular collar 96 secured to the interior wall of the drum shell 50 . The collar 96 includes radially spaced openings 98 around the periphery of the collar at the drum shell 50 to permit aggregate and RAP material to pass from the combustion zone to the mixing zone. Secured adjacent the inside diameter of the collar 96 is a frusto-conical venturi 100 which is concentrically aligned with the longitudinal axis of the drum 60 and which uniformly tapers from a larger diameter at the collar 96 to a smaller diameter in the direction toward the combustion and drying zones. The venture 100 terminates proximate the burner head 68 for the purpose, as will be seen, of channeling secondary combustion air, blue smoke and steam from the mixing zone into the flame envelope 69 within the combustion zone.
[0067] The mixing zone of the present invention is operationally subdivided into two subzones or stages which can most conveniently be thought of as a first region wherein liquid asphalt is added to the aggregate and RAP materials, and a second region wherein the final product components of binder dust or mineral “fines” are added to the mixture of aggregate, RAP and liquid asphalt. Therefore, the first stage of the mixing zone extends generally from the combustion zone to point where fines are added, and the second stage of the mixing zone extends generally from the point where fines are added to the discharge of the final product.
[0068] Throughout the mixing zone and mounted to the interior of the drum shell 50 are rows of mixer flighting 102 to mix and stir material within the annulus formed generally between the drum 50 and combustion assembly 64 . Through the rear wall of the discharge housing 62 extends an injection tube 104 for spraying liquid asphalt into the first stage of the mixing zone. Thus, the spray head 106 of the injection tube 104 is positioned just downstream of the transition piece 94 .
[0069] Closer to the product discharge, a screw auger 108 extends through the rear wall of the discharge housing 62 . Typically, a screw auger is a hollow pipe in which a spiral flight is rotated to carry material through the pipe and out one end. Screw auger 108 of this invention is atypical. From the discharge end and along a length of the auger pipe are a plurality of elongate slots 109 in the bottom of the pipe to permit the discharge of dust and fines along a substantial length of the auger 108 when the spiral flight is rotated within the auger pipe. Moreover, mounted to the auger pipe 108 along opposite sides of the discharge slots therein are a pair of spaced apart, flexible flaps 10 which hang downwardly from the auger 108 into the mixing zone as shown in FIG. 10. The foregoing features result in better mixing of the fines into the final product and minimize entrainment of the fines into the air of the mixing zone.
[0070] As shown in FIGS. 3 & 10, a stationary teepee housing 112 is mounted within the mixing zone, generally above the combustion assembly 64 to shield same from any sticky asphaltic composition that might fall from above while the material components are mixed within the mixing zone and to assist in isolating the second stage of the mixing zone where the dust and fines are added to the mix. The teepee housing is substantially sealed against the rear wall of the discharge housing 62 . Above the teepee housing 112 , a secondary combustion air inlet 114 penetrates the discharge housing 62 to permit the free flow of air into the mixing zone above the teepee housing 112 . The air inlet 114 may be optionally fitted with a damper to partially regulate air flow through the inlet 114 .
[0071] During plant operations, combustion at the burner head 68 is principally supported by the fuel and primary air, but secondary combustion air is introduced through the inlet 114 and eventually reaches the burner head 68 to also support combustion. As a result of the arrangement of the features previously described, the second stage of the mixing zone is unaffected by the flow of secondary combustion air. In other words, the region of the second stage of the mixing zone where the dust and fines are added is substantially isolated from air flow by location, the teepee housing 112 , and the flexible flaps 110 of the screw auger 108 . On the other hand, the first stage of the mixing zone where the liquid asphalt is added and where blue smoke and steam may be present are effectively swept by the secondary combustion air into the combustion zone so that the blue smoke can be incinerated by the flame envelope 69 . Thus, dust entrainment in the mixing zone is minimized and any blue smoke and steam is evacuated to the combustion zone rather than being discharged with the final product.
[0072] Unlike conventional counter-flow asphalt plants, the asphalt plant of this invention optionally includes an exhaust gas burner. Attention is now directed to the upstream portion of FIG. 3 and the end view of FIG. 4. A second combustion assembly 120 extends through the exhaust port housing 59 and into the exhaust gas stream to deliver fuel through supply line 122 and primary air from a blower 124 to a burner head 126 . Combustion at the burner head 126 heats the exhaust gas stream to elevate the temperature thereof before delivery to the baghouse 61 . It is desirable to maintain the temperature of the exhaust gas stream at or above its dew point prior to entry to the air pollution filtration equipment 61 . More or less energy may be supplied to the exhaust gas stream by process control equipment known to those skilled in the art. Illustrated in the drawings is a schematic representation of one example which includes a temperature sensing thermocouple 128 installed in the exhaust port housing 59 or ductwork 60 of the baghouse 61 . The thermocouple 128 is operatively connected to a process controller 130 which, in turn, is connected to the combustion assembly 120 for regulation of the fuel and air supply to support combustion in the exhaust gas stream.
[0073] [0073]FIG. 11 shows a single drum, counter-flow asphalt plant constructed in accordance with a second preferred embodiment of the invention that is similar to the asphalt plant of FIGS. 3-10 but with provisions for total control of both primary and secondary combustion air. In general, the structural details of the FIGS. 3-10 and FIG. 11 plants are the same except for the provision of secondary air to the mixing zone. Instead of the secondary air inlet 114 and the operationally free flow of secondary air as in the FIGS. 3-10 configuration, the discharge housing 62 in FIG. 11 is fitted above the teepee structure 112 with a secondary air blower 132 to forcibly deliver secondary combustion air to the mixing zone. The effect of the secondary air flow is essentially the same as the previous description. In other words, the region of the second stage of the mixing zone where the dust and fines are added is substantially isolated from air flow by location, the teepee housing 112 , and the flexible flaps 110 of the screw auger 108 . On the other hand, the first stage of the mixing zone where the liquid asphalt is added and where blue smoke and steam may be present are effectively swept by the secondary combustion air into the combustion zone so that the blue smoke can be incinerated by the flame envelope 69 . Thus, dust entrainment in the mixing zone is minimized and any blue smoke and steam is positively evacuated to the combustion zone rather than being discharged with the final product.
[0074] [0074]FIG. 12 shows a single drum, counter-flow asphalt plant constructed in accordance with a third preferred embodiment of the invention that is similar to the two previous embodiments but with a modified mixing zone and aspirated secondary combustion air. Comparing the plant of FIG. 3 with that of FIG. 12, the teepee housing 112 and air inlet 114 are absent but the remaining features are the same. In FIG. 12, a large diameter secondary air tube 136 extends through the discharge housing 62 into the mixing zone. The tube 136 terminates intermediate the asphalt spray head 106 and the auger 108 to better define the transition between the first and second stages of the mixing zone. The combustion assembly 64 extends through the tube 136 and forms an open annulus therewith through which ambient air flow is induced during combustion operations.
[0075] As shown, the secondary air tube 136 also serves to shield the combustion assembly 64 from any sticky asphaltic composition that might fall from above while the material components are mixed within the mixing zone and to effectively isolate the second stage of the mixing zone where the dust and fines are added to the mix.
[0076] During plant operations, combustion at the burner head 68 is principally supported by the fuel and primary air, but secondary combustion air is introduced through the tube 136 and eventually reaches the burner head 68 to also support combustion. As a result of the arrangement of the features previously described, the second stage of the mixing zone is unaffected by the flow of secondary combustion air. In other words, the region of the mixing zone where the dust and fines are added is substantially isolated from air flow by location, the secondary air tube 136 , and the flexible flaps 110 of the screw auger 108 . On the other hand, the first stage of the mixing zone where the liquid asphalt is added and where blue smoke and steam may be present are effectively swept by the secondary combustion air into the combustion zone so that the blue smoke can be incinerated by the flame envelope 69 . Thus, dust entrainment in the mixing zone is minimized and any blue smoke and steam is evacuated to the combustion zone rather than being discharged with the final product.
[0077] [0077]FIG. 13 shows a single drum, counter-flow asphalt plant constructed in accordance with a fourth preferred embodiment of the invention similar to the asphalt plant of FIG. 12 but with provisions for total control of both primary and secondary combustion air. Here, the secondary air tube 136 is connected to a positive displacement blower 140 with separate controls to provide and independently regulate both primary and secondary air. Otherwise, the internals of the drum 50 are the same as described with reference to FIG. 12.
[0078] The foregoing features of the invention both individually and in combination offer remarkable benefits to modern asphalt plant design, construction and operations. RAP material is introduced directly into the hottest area of the drum and directly exposed to radiant heat of the flame envelope. High percentage RAP mixes (up to 50%) are now possible without excessive equipment shell temperatures or excessive exhaust gas temperatures. The limited residence time in the combustion zone generally keeps the RAP below the smoke point, but any blue smoke formed in the combustion zone can still be incinerated without passing into the baghouse because the feed entry is positioned intermediate the ends of the combustion zone.
[0079] The recycle feed assembly can also be used to introduce both RAP material, virgin material or a combination of both in order to reduce NO x emissions. This is achieved by introducing the wet materials (RAP or virgin) at the hot part of the combustion zone. The steam produced by the moisture laden material acts to cool the combustion zone hereby reducing the formation of thermally produced NO x .
[0080] Provision of a secondary burner for the exhaust gas stream permits precision control of the exhaust gas temperatures for maximum fuel efficiency. Equipment life is extended by eliminating the need to superheat virgin aggregates. Highly efficient heat transfer in the heating/drying zone of asphalt plant permits operations with the gas in the drying zone to sink as low as 180° F. with energy addition prior to delivery of the gas to the baghouse at or above its dew point in the range of 225° F. The plant operator can now standardize on the use of use of polyester bags (275° F. maximum service) rather than NOMEX (375° F. maximum service) bags to achieve a cost reduction of approximately 80%.
[0081] Likewise, the features of this invention alternatively permit either increased production or decreased sizes of the equipment required for a given production rate because both the BTU and CFM requirements are reduced as a result of the lower stack temperature. These highly significant advantages and benefits can be understood with reference to the following sizing calculations table.
Sizing Calculations Table
[0082] Calculation Assumptions: Counter-flow Drum, 650□ Elevation, #2 Fuel Oil, 5% Moisture, 320° F. Mix 900 FPM Drum Throughput, 3500 FPM Inlet Duct, 4400 FPM Stack
TPH BTU S × 1,000,000 DRYER DIA. INLET DUCT DIA. BAGHOUSE SIZE STACK DIA. 375 DEGREE STACK: 200 55.91 87.5 44.5 37,500 ACFM 39.5 300 83.87 107 54.25 56,200 ACFM 48.5 400 111.83 123.5 62.75 74,900 ACFM 56 500 139.79 138 70 93,600 ACFM 62.5 600 167.74 151.5 76.75 112,400 ACFM 68.5 300 DEGREE STACK: 200 53.25 82 41.5 33,000 ACFM 37 300 79.87 100.5 51 49,500 ACFM 45.5 400 106.49 116 58.75 65,900 ACFM 52.5 500 133.12 129.5 65.75 82,400 ACFM 58.5 600 159.74 142 72 98,900 ACFM 64 225 DEGREE STACK: 180 DEGREES DRYER EXHAUST GAS TEMPERATURE: 200 50.74 73.5 39 28,800 ACFM 34.75 300 76.11 89.75 47.5 43,100 ACFM 42.5 400 101.48 103.5 55 57,500 ACFM 49 500 126.85 115.75 61.5 71,900 ACFM 54.75 600 152.22 127 67 86,200 ACFM 60
[0083] By utilizing both the unique combustion entry RAP system combined with a dual burner configuration, in the example of a 50% recycle plant, such a system has a reduced size of the air handling equipment, including the dust collection system, by 20%, and the combustion equipment by 10%.
[0084] The size of the typical 400 ton per hour drum/dryer, for example, goes from 10□-3″ diameter to 8□-8″ diameter. The size of the baghouse filter collector on the same plant goes from a 75,000 ACFM capacity requirement to a 57,500 ACFM requirement. The size of the burner goes from 112 million BTU down to 101 million BTU. Such savings are heretofore unknown for modern asphalt plants.
[0085] From the foregoing it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth, together with the other advantages which are obvious and which are inherent to the invention.
[0086] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
[0087] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
[0088] Numerals
[0089] Prior Art
[0090] drum mixer 10
[0091] support frame 12
[0092] motor driven rollers 14
[0093] trunnion rings 16
[0094] rotational arrow 17
[0095] aggregate feeder 18
[0096] exhaust port 20
[0097] discharge housing 22
[0098] combustion assembly 24
[0099] blower 26
[0100] burner head 28
[0101] dryer flights 29
[0102] combustion flights 30
[0103] recycle feed assembly 34
[0104] stationary box channel 35
[0105] feed hopper 36
[0106] flexible seals 37
[0107] scoops 38
[0108] scoop opening 40
[0109] sawtooth flighting 42
[0110] screw auger 44
[0111] injection tube 46
[0112] Invention
[0113] cylindrical drum 50
[0114] support frame 52
[0115] drive rollers 54
[0116] trunnion rings 56
[0117] aggregate feeder 58
[0118] exhaust port 59
[0119] ductwork 60
[0120] air pollution control equipment 61
[0121] discharge housing 62
[0122] combustion assembly 64
[0123] fuel line 65
[0124] blower 66
[0125] burner head 68
[0126] flame envelope 69
[0127] dryer flights 70
[0128] recycle feed assembly 72
[0129] box channel 75
[0130] support legs 75 a
[0131] feed hopper 76
[0132] flexible seals 77
[0133] scoop openings 78
[0134] combustion flighting 80
[0135] scoop plates 82
[0136] rotational arrow 84
[0137] flighting web 88
[0138] angled leading lip 88 a
[0139] main body portion 88 b
[0140] angles trailing lip 88 c
[0141] clip bracket 90
[0142] pin 92
[0143] transition member 94
[0144] annular collar 96
[0145] radially spaced openings 98
[0146] venturi 100
[0147] mixer flighting 102
[0148] injection tube 104
[0149] spray head 106
[0150] screw auger 108
[0151] elongate slots 109
[0152] flexible flaps 110
[0153] teepee housing 112
[0154] secondary combustion air inlet 114
[0155] secondary combustion assembly 120
[0156] fuel supply line 122
[0157] blower 124
[0158] burner head 126
[0159] thermocouple 128
[0160] process controller 130
[0161] [0161]FIG. 11
[0162] secondary air blower 132
[0163] [0163]FIG. 12
[0164] secondary air tube 136
[0165] [0165]FIG. 13
[0166] positive displacement blower 140 | A counter-flow drum mixer asphalt plant equipped with a secondary feeder for introducing RAP to direct radiant heat of the combustion zone. Heated virgin aggregate and RAP in the combustion zone are delivered through a transition piece to a first stage of the mixing zone where liquid asphalt is combined with the materials and secondary combustion air flows through the first stage to evacuate blue smoke and steam back to the combustion zone. The second stage of the mixing zone is substantially isolated from secondary combustion air flow where dust and mineral fines are introduced and mixed to complete the asphalt product discharged from the mixing zone. Alternative constructions of the mixing zone are disclosed to provide the first and second stages having such characteristics, as well as options for both the passive and active control of the secondary combustion air. An optional secondary burner in the exhaust housing elevates the temperature of the exhaust gas above its dew point temperature before delivery to the baghouse. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Priority of the present application is based on provisional application No. 60/070,039 filed Dec. 30, 1997.
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates to chucks for gripping workpieces and, more particularly, to a quick-change collet chuck for gripping and installing container caps during an automated high-volume filling and capping process.
2. Description of the Background
The filling and capping process generally entails supplying containers along a conveyor, automatically filling them at a filling station, and automatically capping them at a capping station. Various testing and control functions may be performed along the way, e.g., testing and control of fill volume, cap torque, conveyor velocity, etc. The apparatus which performs the process must be capable of accommodating a wide variety of containers and caps (both caps and containers may vary in size and shape), and this is accomplished by a universal chuck which allows quick and easy grasping and manipulation of different cap sizes.
Current common methodology for screw cap positioning and torquing include the following types of chucks:
Tapered Chuck
Friction Disk Chuck
Donut Chuck
Segmented Chuck
The action of the Tapered Chuck and the Friction Disk chucks is to apply axial (downward) force to generate the friction drive between the cap top (rim) and the chuck taper or friction disk. Having to avoid damage to the container, cap, and/or thread the axial force is limited. Thus tapered chucks and friction disc chucks can only handle a limited type of caps in relatively low torque applications which severely restricts the usage of these chucks. Another disadvantage of these chucks is their possible contamination by their own (or from the caps) particulates. Shavings may prevent required torque transfer since the driving axial force is limited in order not to damage the container and/or thread. These shavings can cause slippage that will perpetuate the problem. Simple friction drives such as the Tapered Chuck and the Friction Disk Chuck are not desirable in pharmaceutical clean packaging environments due to potential particulate generation from slippage.
The Donut Chuck includes a urethane ring (open center diameter matched in size to the cap) that, when a concentric cylinder is actuated, swells inward to clamp (radial pressure) on the outside of the cap thus enabling torque transfer as required. This is a friction drive but the friction force is generated not by axial but by a radial force compressing the cap. Normally this allows for a significantly higher torque range compared to the simple friction drives mentioned above. No axial force to risk the damage of the container or threads. However, there are a significant number of parts to be changed when changing from one cap size to another, enough that often the complete chuck is exchanged. Besides the tool requirement to do this, there is significant cost involved. The Donut Chuck has a working torque range good for up to medium (average) torque requirements (The particulate generation is minimal due to the clamping force being well in excess to what is required for transfer of the normal required torque thus resulting in no slippage between the cap and the donut).
The Segmented Chuck concept is specifically for the high torque range caps that typically have more severe serrations or other significant protrusions on the outside cap (radial) surface. The segmented chuck may, for instance, include a 3 piece segmented chuck jaw set (each segment occupying 120 degrees). However, this 3 piece segmented design is very heavy and clumsy, and it suffers from somewhat unstable jaw segments. In addition, the multi-segmented jaw set concept is very expensive to manufacture, and it does not lend itself to quick changing for different size caps. The chuck jaws are designed to match the cap outside profile and by a true interlock (when the jaws close) to facilitate positive (i.e. non-friction) drive for high torque requirements. Due to the expensive segmented die jaws concept of positive locking being very different from the Donut Chuck friction concept, this chuck does not lend itself economically to any simple applications. Again the change parts are enough trouble that for each cap size a complete new chuck is the practical solution. A whole chuck (inclusive of jaws) needs to be changed. Moreover, the mass of the three piece segmented chuck results in a high inertia which interferes with high speed operation. The chuck is servo driven and the servo motor provides positive feedback on the power required to turn/torque the cap. The high inertia of the chuck contaminates this data and limits the torquing speeds (and the overall production rates). A lower inertia results in more accurate torquing and higher production speeds.
It would be a great advantage to have a quick-change low-inertia collet-type chuck to allow quick and effortless swapping out of different size jaw sets for different size caps.
The Collet Chuck concept of a universal chuck to actuate a quick-change one-part collet as the only change part is far superior to the Donut Chuck and the Segmented Jaw Chuck since collets can be made to work the whole working range of these other two chucks. A low cost urethane lined collet will drive the caps with lower torque requirements. A machined contact profile collet will drive the caps with high torque requirements (positive interlocking with the external cap profile). Even asymmetric caps could be clamped in custom collets without requiring a special chuck change (The collet orientation relative to the chuck is always an exact repeat and servo drive allows an exact chuck orientation repeat). Preferably, there should be virtually no down time (or skill level) associated with the collet change.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an improved quick-change collet chuck for use in handling virtually any work piece.
It is a more specific object to provide a quick-change collet chuck to allow quick and effortless swapping out of different size jaw sets for different size caps while minimizing any interruption of the container capping process.
It is still another object to provide a quick-change collet chuck which incorporates a unitary jaw set for increased durability and reliability, lower manufacturing cost, and greater ease of handling.
It is a further object to provide a chuck as described above with the lowest inertia possible so as not to interfere with high speed operation and accurate servo torquing.
It is still another object to insure that the collet chuck cannot unscrew or spin loose from the spindle shaft after the quick-change collet is already locked in position, thereby facilitating reversible operation when it is desirable to include cap removal and removal torque testing on the capping machine.
Additional objects include stainless construction and a no-tools quick-change design.
In accordance with the above objects, an improved quick-change collet chuck is described for use in an existing single lane capping apparatus for gripping and installing container caps during the automated high-volume filling and capping process. The quick-change collet chuck allows quick and effortless swapping out of different size jaw sets for different size caps while minimizing interruption and down time of the automated container capping processes. The quick-change collet chuck has a slim profile for low inertia so as not to interfere with high speed operation and accurate servo-torquing. Another feature is shown in conjunction with the quick-change collet chuck to facilitate reversible operation when it is desirable to include cap removal and removal torque testing on the capping machine. This feature insures that the collet chuck and collet cannot unscrew or spin loose from the spindle shaft after the quick-change collet is already locked in position. It would be a great advantage to have a quick-change low-inertia collet-type chuck to allow quick and effortless swapping out of different size jaw sets for different size caps.
The quick change collet chuck of the present invention was specifically developed for cap positioning and torquing in pharmaceutical Clean Room Class 100, although it should be understood that the inventive concept may apply in many other contexts. The Class 100 refers to the quantity of particles permitted (in the exposed product zone): 100 particles per cubic foot between the 0.5 micron and 5-micron size. This means special clothing and gloves for operators to reduce particulate generation. This aspect comes into play in the chuck design as well. The major source of particulate generation in the typical Clean Room is the human operator. Any unnecessary movements by the operator/mechanic in a Class 100 room results in (relatively) huge particulate generation. Simple, light, no-tools quick-change tooling is an extremely effective way of avoiding this type of particulate generation. For changeover the “J” lock in the present chuck is as simple as can be: push, twist by ⅛ turn, let go.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment and certain modifications thereof when taken together with the accompanying drawings in which:
FIG. 1 is a perspective view of an existing single lane capping apparatus 10 incorporating a quick-change collet chuck 20 according to the present invention for gripping and installing container caps during the automated high-volume filling and capping process.
FIG. 2 is a side view of the single lane capping apparatus 10 with quick-change collet chuck 20 of FIG. 1 .
FIG. 3 is a side close-up view of the quick-change collet chuck 20 of FIGS. 1 and 2.
FIG. 4 is an upwardly directed close-up view of the quick-change collet chuck 20 of FIGS. 1 - 3 .
FIG. 5 is a side sectional view of the quick-change collet chuck 20 of FIGS. 1 - 4 without collet 22 .
FIG. 6 is a side sectional view of the quick-change collet chuck 20 with collet 22 .
FIGS. 7, 8 and 9 are a side sectional view, a side perspective view, and a top view, respectively, of Piston 101 .
FIGS. 10, 11 , 12 and 13 are a side sectional view, a side perspective view, a bottom view, and a top view, respectively, of the Bell 102 which serves as the piston gland and wall.
FIGS. 14, 15 , 16 , 17 and 18 are a side sectional view, a side sectional view rotated by 90 degrees, a side perspective view, a bottom view, and a top view, respectively, of the Shaft 103 .
FIGS. 19 and 20 are a side sectional view, and a top view, respectively, of the Bushing 104 .
FIGS. 21, 22 , 23 , 24 , 25 , 26 , 27 and 28 are a front perspective view, a close-up perspective view at the top, a close-up perspective view at the bottom, a side sectional view, a side perspective view, a side sectional view rotated by 90 degrees, a top view, and a bottom view, respectively, of the collet 22 according to one embodiment of the present invention.
FIG. 29 is a profile drawing illustrating another embodiment of collet 22 in which the hook of channel 20 is eliminated.
FIGS. 30, 31 and 32 show a top perspective view, an end cross-section, and a side cut-away view, respectively, of a two-position release slide pin for use with the collet 22 of FIG. 29 which eliminates the need for the hook of channel 260 without sacrificing the quick-release feature.
FIG. 33 is a side cut-away drawing illustrating the placement of a conventional ball-detent mechanism 140 for cooperation with the quick release pin of FIGS. 30 - 32 by insertion into the hollowed lower tip of Shaft 103 , thereby helping to eliminate the need for the hook of channel 260 without sacrificing the quick-release feature.
FIG. 34 illustrates the use of a “draw bolt” 320 to effect reversibility when cap removal and removal torque testing is desirable. Draw bolt 320 may be used with any of the above collet/chuck embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view of an existing single lane capping apparatus 10 incorporating a quick-change collet chuck 20 according to the present invention for gripping and installing container caps during the automated high-volume filling and capping process. Bottles 40 or other containers are urged along a conveyor to a capping position. The capping apparatus 10 is supported on adjustable air pistons 30 , and it extends the quick-change collet chuck 20 downward toward the bottle 40 .
FIG. 2 is a side view of the single lane capping apparatus 10 with quick-change collet chuck 20 of FIG. 1 . During a capping maneuver, a cap 42 is rotated into position on a pivoting arm 44 and upwardly presented into the open quick-change collet chuck 20 . Bottle cap 42 is clamped within the jaws of the collet 22 inserted in quick-change collet chuck 20 . Once the bottle is properly positioned, the capping apparatus 10 extends the quick-change collet chuck 20 downward to seat the bottle cap 42 on the neck of the bottle 40 , and then rotates the collet chuck 20 to screw the bottle cap 42 onto the neck of bottle 40 . All movements of the capping apparatus 10 are electronically controlled in accordance with pressure/torque feedback to insure that the cap 42 is properly seated and screwed onto the bottle 40 .
FIG. 3 is a side close-up view of the quick-change collet chuck 20 of FIGS. 1 and 2. In the illustrated position, a cap 42 has been lifted by pivoting arm 44 and is held in the grip of the collet 22 prior to placement on the neck of bottle 40 (the arm 44 is rotated out of harm's way prior to the chuck lowering to place the cap 42 on the bottle 40 ).
FIG. 4 is an upwardly directed close-up view of the quick-change collet chuck 20 of FIGS. 1 - 3 . Again, cap 42 has been lifted up by arm 44 and is held in the grip of the collet 22 prior to placement on the neck of bottle 40 .
FIG. 5 is a side sectional view of the quick-change collet chuck 20 without collet 22 .
FIG. 6 is a side sectional view of the quick-change collet chuck 20 of FIGS. 1 - 5 with collet 22 inserted therein. The collet 22 is a generally cylindrical unitary member formed with an upper mounting collar, a downwardly flared mid section, and a lower cap gripping section. The downwardly flared mid section and lower cap gripping section are interrupted by a plurality of longitudinal notches which give the cap gripping section the ability to expand or contract to release/grip a bottle cap inserted therein.
With reference to FIGS. 5 and 6, the chuck consists of the Shaft 103 that connects with the hollow drive shaft supplied with the existing capping apparatus 10 . Shaft 103 is drilled laterally toward its lower extremity to receive a pin 105 . Preferably, a stepped pin 105 is used to ensure unique orientation as will be described. Quick-release collet 22 is inserted over the end of shaft 103 and is captured by pin 105 , thereby retaining the collet 22 . Shaft 103 is formed with a deep central bore (dotted lines) to bring an external air supply inside the collet chuck 20 , and the upper end of Shaft 103 is drilled laterally to provide an air passage 110 for bleeding air through the central bore. The air supply is directed into a cavity 711 existing between a Bell 102 and the face is of Piston 101 . When the air supply is activated the cavity 711 is pressurized and piston 101 is urged downward. A Bushing 104 is slipped over Shaft 103 , and this may be formed of Delrin plastic or other suitable bushing material. As seen in FIG. 6, Bushing 104 serves to retain a compression spring 106 that is required for return of piston 101 (after the air pressure is removed). Bushing 104 also serves as a guide for piston 101 to prevent racking and serves as a pressure pad for latching the quick-release collet 22 .
Piston 101 comprises an upper disk with a unitary extension sleeve protruding downwardly. The disk of piston 101 is machined with an inner O-ring groove for housing an inner O-ring 107 (or alternatively, a cup seal) that seals against the Shaft 103 , and with an outer O-ring groove for housing an outer O-ring 108 that seals against the inner wall of a Bell 102 . The inside bore of the extension sleeve of Piston 101 also serves as a guide surface for the Bushing 104 to prevent racking of the piston. The Bell 102 serves as the piston gland and wall.
The action of the quick-change collet chuck 20 is as follows. Air pressure from an external source is applied though air passage 110 and through the upper bore in Shaft 103 , and air trapped in the cavity 711 between the Bell 102 and Piston 101 face forces the Piston 101 downward. The sleeve of the Piston 101 transfers the force produced to the downwardly flared mid section of collet 22 . As the Piston 101 is forced out, the annular lower lip of the Piston 101 sleeve forces the collet 22 to flex inward (contract) as it slides along the flared mid section of collet 22 . Once the air pressure is removed, the return spring 106 forces the Piston 101 upward until it reseats against the limiting wall of Bell 102 , and the collet 22 is allowed to flex open again as the sleeve retracts off the flared mid section of collet 22 .
FIGS. 7, 8 and 9 are a side sectional view, a side perspective view, and a top view, respectively, of Piston 10 1 showing the upper disk 111 with unitary extension sleeve 112 protruding downwardly. Again, the disk 111 of piston 101 is machined with an inner O-ring groove 114 for housing inner O-ring 107 , and an outer O-ring groove 113 for housing outer O-ring 108 . The inside bore of the extension sleeve 112 of Piston 101 is a smooth and uniform guide surface for Bushing 104 , and the bottom rim is thicker and rounded to provide a bearing surface.
FIGS. 10, 11 , 12 and 13 are a side sectional view, a side perspective view, a top view, and a bottom view, respectively, of the Bell 102 which serves as the piston gland and wall. Bell 102 is a generally cylindrical hollow cap which covers and seals the upper end of Piston 101 . Bell 102 is formed with a reduced-diameter neck 121 having a central through-bore for receiving Shaft 103 . The other end is an expanded collar 122 having a smooth inner wall for slidable insertion onto the upper end of Piston 101 and over O-ring 108 .
FIGS. 14, 15 , 16 , 17 and 18 are a side sectional view, a side sectional view rotated by 90 degrees, a side perspective view, a bottom view, and a top view, respectively, of the Shaft 103 . Shaft 103 is a generally cylindrical member that is drilled lengthwise to form a central air passage 131 , the mouth of which connects with a hollow drive shaft supplied with the existing capping apparatus 10 . Shaft 103 is also drilled to form a lateral bore 133 toward its lower extremity to receive pin 105 . Shaft 103 is also drilled to form an upper lateral bore 132 toward its upper extremity. Upper bore 132 communicates with the central passage 131 to bleed air outwardly. In operation, Bushing 104 is inserted over the Shaft 103 . As seen in FIGS. 15 and 16, shaft 103 is formed with a raised section 135 around the lateral bore 133 for reinforcement of the pin to be inserted therein and to provide a stop for Bushing 104 .
FIGS. 19 and 20 are a side sectional view and a top view, respectively, of the Bushing 104 . Bushing 104 is formed in the shape of a cylindrical collar with protruding lower flange and is made of Delrin plastic or other suitable material. Bushing 104 is sized for insertion over the Shaft 103 and serves to retain compression spring 106 . Bushing 104 also serves as a guide for piston 101 to prevent racking and serves as a pressure pad for latching the quick-release collet 22 .
FIG. 21 is a front perspective view of the quicl-release collet 22 according to one embodiment of the present invention. The collet 22 is a generally cylindrical unitary member formed with an upper mounting collar 210 , a downwardly flared mid section 220 , and a lower cap gripping section 230 . The downwardly flared mid section 220 and lower cap gripping section 230 are interrupted by a plurality of longitudinal notches 240 which give the cap gripping section 230 the ability to expand or contract to release/grip a bottle cap inserted therein.
FIG. 22 is a close-up side perspective view of the upper mounting collar 210 of collet 22 . Upper mounting collar 210 is formed with a lateral through-bore 250 , and with opposing hooked or “J-lock” mounting channels 260 for effecting the quick-change feature. Each of the J-lock mounting channels 260 has an open mouth leading to a closed hook. The stepped pin 105 comprises a cylindrical main section having a larger diameter r 1 , and a cylindrical end section having a slightly smaller diameter r 2 . This stepped pin configuration is used in conjunction with two differently-sized J-lock mounting channels 260 to ensure a unique orientation of the pin 105 . Specifically, the closed hook of one J-lock mounting channel 260 is formed with a larger diameter w 1 that conforms to the diameter R 1 of the main section of pin 105 , while the opposing J-lock mounting channel 260 is formed with a smaller diameter w 2 that conforms to the diameter r 2 of the end section of pin 105 . This way, after the pin 105 has been inserted through the open mouths of both J-lock mounting channels 260 , the collet 22 can only be twisted to properly seat the stepped pin 105 in the closed hooks if the two differently-sized J-lock mounting channels 260 are properly oriented with respect to the two sections of pin 105 . This ensures the proper orientation.
In operation, and with additional reference back to FIG. 6, pin 105 is inserted through the shaft 103 . The quick-release collet 22 is then inserted over the end of shaft 103 until the ends of pin 105 enter the mouths of the J-lock mounting channel 260 of collet 22 . The collet 22 is rotated and the ends of pin 105 are guided around and into the hooks of channels 260 and become captive therein, thereby retaining the collet 22 . All the while, the chuck piston return spring 106 doubles as a latching spring for the collet 22 , e.g., chuck piston return spring 106 exerts a downward pressure on collet 22 and insures that the mounting channel 260 remains hooked on pin 105 . Once the chuck cylinder is pressurized, the force it produces will re-enforce the latching action of spring 106 and the collet is positively retained. Once the pressure is removed from the chuck, the collet 22 is easily and manually removed by ⅛-turn push-turn-pull motion. This is ideal because the collet change does not require tools, time, or thought, and it avoids loose parts which can be lost or misplaced.
FIG. 23 is a side close-up perspective view of the lower cap gripping section 230 of collet 22 according to one embodiment of the present invention. As is known in the art, the inner jaws of the lower cap gripping section 230 may be serrated as shown, or they may be lined with a rubber gripping material as desired depending on the particular caps to be installed.
FIGS. 24, 25 , 26 , 27 and 28 are a side sectional view, a side perspective view, a side perspective view rotated by 90 degrees, a top view, and a bottom view, respectively, of the collet 22 according to the present invention. It is that noteworthy that the design of the above-described collet chuck 20 insures that the Shaft 103 remains fully behind the collet 22 thus allowing a smaller piston inside diameter. Using lateral through-bore 250 and J-lock mounting channel 260 for effecting the quick-change feature, the built-in concentric chuck cylinder is behind the collet 22 rather than around it. Consequently, the “flywheel” effect (rotational momentum) is minimized by keeping the mass as close to the rotational axis as possible. The inertia is calculated as proportional to MR 2 (mass x radius squared). Calculations indicate that the inertia of the present QuickChange Collet Chuck design is 27% of competing segmented jaw chucks, and the mass is only 40%. This very low inertia becomes very important in achieving high production rates with accurate application torque. Most screw caps are applied in 1½ to 2½ turns. The fastest most accurate application algorithm for cap torquing is to use a servo motor to rotate the cap at high speed for the first (approximately) 1¼ turn and than abruptly slow to low speed to finish the torquing accurately (better resolution). The servo motor is capable of giving feedback of the current required to rotate the cap at any instant of time. Any large inertia contaminates this feedback information since it no longer only represents the power required to turn the cap at the low speed. If the cap is fully torqued at exactly 1½ turns the flywheel effect can easily skew the feedback (in comparison to 2½ turns with 1 full turn at low speed). To achieve the higher production rates the initial high rotational speed is crucial. This all boils down into a need for low inertia of all rotating mass, and the present invention meets the need. The outside diameter will be small as well, keeping the inertia low. The lower inertia results in more accurate torquing and higher production speeds because there is less interference with high speed operation and feedback power reading of the servo motor.
FIG. 29 is a profile drawing illustrating a second embodiment of collet 322 in which the hook or J-lock design of channel 20 is eliminated. The J-lock is not necessary with the use of a modified 2-position slide release pin as will be described, yet this also accomplishes the quick-release feature.
FIGS. 30, 31 and 32 show a top perspective view, an end cross-section, and a side cut-away view, respectively, of the two-position slide release pin 105 for use with the collet 322 of FIG. 29 . This eliminates the need for the hook or J-lock of channel 260 without sacrificing the quick-change feature. Collet 322 can be easily and manually changed without tools by shifting pin 105 . Two-position slide release pin 105 is sized for insertion in the lateral through-bore 360 in upper mounting collar 310 of collet 322 . A detent channel 330 is centrally located, and this is preferably a shallow notch leading to a slightly deeper pocket.
As seen in FIG. 30 and combined with reference to FIG. 29, pin 105 incorporates opposing side notches 320 at each end which correspond to the walls of upper mounting collar 310 . These side notches 320 allow the collet 333 to be removed when they are aligned with the vertical slot leading into the lateral through-bore 360 in the collet 322 . Thus, when slid to an open position, the opposing side notches 320 form a narrow cross-section to allow easy insertion or removal of collet 322 . However, when slid to a closed position the opposing side notches 320 form a broader cross-section to lock the collet 322 in position.
FIG. 33 is a side cut-away drawing illustrating the placement of a detent mechanism for cooperation with the quick release pin 105 of FIGS. 30 - 32 . The detent channel 330 cooperates with a detent pin 335 which can be mounted inside the lower end of Shaft 103 . The detent pin 335 is a simple spring-loaded detent pin with a pointed tip as shown.
When pin 105 is inserted laterally into the piston 103 , the detent pin 335 enters detent channel 330 and seats the pin 105 upon reaching the deeper pocket. Once seated in the deeper pocket of detent channel 330 , the detent pin 335 holds the slide pin 105 in closed position and thereby locks collet 322 in position. The pin 105 can be conveniently and manually slid from the locked or closed position to the unlocked or open position, thereby enabling quick-change insertion/removal of collet 22 without tools. Given the two-position slide release pin 105 of FIGS. 30 - 32 with detent pin of FIG. 33, the collet itself need not be press and twist-on embodiment shown in FIGS. 21 - 28 .
Another feature may be incorporated into the above-described collet chuck to facilitate reversible operation. This is significant when it is desirable to include cap removal and removal torque testing on the capping machine 10 . This feature requires that the chuck 20 cannot unscrew or spin loose from the spindle shaft since the quick-change collet 22 is already locked in position by the above-described quick-release mechanisms. As shown in FIG. 34, the reversibility is accomplished with an internally threaded “draw bolt” 320 that screw-attaches to the collet chuck 20 and tightens, thereby allowing it to be pre-loaded well in excess of the working application torque by at least a factor of 10. This facilitates reversibility by far exceeding the “break-loose” torque between the existing spindle shaft and chuck shaft (the rotary spline assembly and spindle shaft are existing components of a single lane capping apparatus. The collet chuck assembly 20 itself remains unchanged but reversibility is facilitated. Draw bolt 320 may be used with any of the above-described collet/chuck embodiments.
Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. | An improved quick-change collet chuck used with an existing single lane capping apparatus for gripping and installing container caps during the automated high-volume filling and capping process. The quick-change collet chuck allows quick and effortless swapping out of different size jaw sets for different size caps and minimizes interruption and downtime during the automated container capping processes. The quick-change collet chuck has a slim profile for low inertia so as not to interfere with high speed operation and accurate servo torquing. Another optional feature is shown in conjunction with the quick-change collet chuck to facilitate reversible operation when it is desirable to include on-the-fly cap removal and removal torque testing on the capping machine. This feature insures that the collet chuck cannot unscrew or spin loose from the spindle shaft after the quick-change collet is already locked in position. | 1 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a building block comprising a complementing element and a precursor for a functional entity. The building block is designed to transfer the functional entity precursor with an adjustable efficiency to a recipient reactive group upon recognition between the complementing element and an encoding element associated with the reactive group. The invention also relates to a method for transferring a functional entity precursor to recipient a reactive group.
BACKGROUND
[0002] The transfer of a chemical entity from one mono-, di- or oligonucleotide to another has been considered in the prior art. Thus, N. M. Chung et al. (Biochim. Biophys. Acta, 1971, 228,536-543) used a poly(U) template to catalyse the transfer of an acetyl group from 3′-O-acetyladenosine to the 5′-OH of adenosine. The reverse transfer, i.e. the transfer of the acetyl group from a 5′-O-acetyladenosine to a 3′-OH group of another adenosine, was also demonstrated.
[0003] Walder et al. Proc. Natl. Acad. Sci. USA, 1979, 76, 51-55 suggest a synthetic procedure for peptide synthesis. The synthesis involves the transfer of nascent immobilized polypeptide attached to an oligonucleotide strand to a precursor amino acid attached to an oligonucleotide. The transfer comprises the chemical attack of the amino group of the amino acid precursor on the substitution labile peptidyl ester, which in turn results in an acyl transfer. It is suggested to attach the amino acid precursor to the 5′ 0 end of an oligonucleotide with a thiol ester linkage.
[0004] The transfer of a peptide from one oligonucleotide to another using a template is disclosed in Bruick RK et al. Chemistry & Biology, 1996, 3:49-56. The carboxy terminal of the peptide is initially converted to a thioester group and subsequently transformed to an activated thioester upon incubation with Ellman's reagent. The activated thioester is reacted with a first oligo, which is 5′-thiol-terminated, resulting in the formation of a thio-ester linked intermediate. The first oligonucleotide and a second oligonucleotide having a 3′ 0 amino group is aligned on a template such that the thioester group and the amino group are positioned in close proximity and a transfer is effected resulting in a coupling of the peptide to the second oligonucleotide through an amide bond.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a building block of the general formula:
Complementing Element-Linker-Carrier-C—F-connecting group-Functional entity precursor
capable of transferring a Functional entity precursor to a recipient reactive group, wherein
Complementing Element is a group identifying the Functional entity precursor, Linker is a chemical moiety comprising a spacer and a S—C-connecting group, wherein the spacer is a valence bond or a group distancing the Functional entity precursor to be transferred from the complementing element and the S—C-connecting group connects the spacer with the Carrier Carrier is arylene, heteroarylene, C 1 -C 6 alkylene, C 1 -C 6 alkenylene, C 1 -C 6 alkynylene, or —(CF 2 ) m — substituted with 0-3 R 1 wherein m is an integer between 1 and 10;
[0009] R 1 are independently selected from —H, —OR 2 , —NR 2 2 , —Halogen, —NO 2 , —CN, —C(Halogen) 3 , —C(O)R 2 , —C(O)NHR 2 , C(O)NR 2 2 , —NC(O)R 2 , —S(O) 2 NHR 2 , —S(O) 2 NR 2 2 , —S(O) 2 R 2 , —P(O) 2 —R 2 , —P(O)—R 2 , —S(O)—R 2 , P(O)—OR 2 , —S(O)—OR 2 , —N + R 2 3 , wherein R 2 is H, C 1 -C6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, or aryl,
C—F-connecting group is chosen from the group consisting of —SO 2 —O—, —O—SO 2 —O—, —C(O)—O—, —S + (R 3 RRrr)—, —C—U—C(V)—O—, —P + (W) 2 —O—, —P(W)—O— where U is —C(R 2 ) 2 , —NR 2 — or —O—; V is ═O or ═NR 2 and W is —OR 2 or —N(R 2 ) 2
[0011] Functional entity precursor is —C(H)(R 3 )—R 4 or functional entity precursor is heteroaryl or aryl optionally substituted with one or more substituents belonging to the group comprising R 3 and R 4 .
[0012] Wherein R 3 and R 4 independently is H, alkyl, alkenyl, alkynyl, alkadienyl, cycloalkyl, cycloheteroalkyl, aryl or heteroaryl, optionally substituted with one or more substituents selected from the group consisting of SnR 5 R 6 R 7 , Sn(OR 5 )R 6 R 7 , Sn(OR 5 )(OR 6 )R 7 , BR 5 R 6 , B(OR 5 )R 6 , B(OR 5 )(OR 6 ), halogen, CN, CNO, C(halogen) 3 , OR 5 , OC(═O)R 5 , OC(═O)OR 5 , OC(═O)NR 5 R 6 , SR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , N 3 , NR 5 R 6 , N + R 5 R 6 R 7 , NR 5 OR 6 , NR 5 NR 6 R 7 , NR 5 C(═O)R 6 NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , NC, P(═O)(OR 5 )OR 6 , P + R 5 R 6 R 7 , C(═O)R 5 , C(═NR 5 )R 6 , C(═NOR 5 )R 6 , C(═NNR 5 R 6 ), C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 , C(═O)NR 5 NR 6 R 7 , C(═NR 5 )NR 6 R 7 , C(═NOR 5 )NR 6 R 7 or R 8 , wherein,
[0013] R 5 , R 6 , and R 7 independently is H, alkyl, alkenyl, alkynyl, alkadienyl, cycloalkyl, cycloheteroalkyl, aryl or heteroaryl, optionally substituted with one or more substituents selected from the group consisting of halogen, CN, CNO, C(halogen) 3 , ═O, OR 8 , OC(═O)R 8 , OC(═O)OR 8 , OC(═O)NR 8 R 9 , SR 8 , S(═O)R 8 , S(═O) 2 R 8 , S(═O) 2 NR 8 R 9 , NO 2 , N 3 , NR 8 R 9 , N + R 8 R 9 R 10 , NR 5 OR 8 , NR 5 NR 6 R 7 , NR 8 C(═O)R 9 , NR 8 C(═O)OR 9 , NR 8 C(═O)NR 9 R 10 , NC, P(═O)(OR 8 )OR 9 , P + R 5 R 6 R 7 , C(═O)R 8 , C(═NR 8 )R 9 , C(═NOR 8 )R 9 , C(═NNR 8 R 9 ), C(═O)OR 8 , C(═O)NR 8 R 9 , C(═O)NR 8 OR 9 C(═NR 5 )NR 6 R 7 , C(═NOR 5 )NR 6 R 7 or C(═O)NR 8 NR 9 R 10 , wherein R 5 and R 3 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring, wherein,
[0014] R 8 , R 9 , and R 10 independently is H, alkyl, alkenyl, alkynyl, alkadienyl, cycloalkyl, 20 cycloheteroalkyl, aryl or heteroaryl and wherein R 8 and R 9 may together form a 3-8 membered heterocyclic ring or R 8 and R 10 may together form a 3-8 membered heterocyclic ring or R 9 and R 10 may together form a 3-8 membered heterocyclic ring.
[0015] In the present description and claims, the direction of connections between the various components of a building block should be read left to right. For example an S—C-connecting group —C(═O)—NH— is connected to a Spacer through the carbon atom on the left and to a Carrier through the nitrogen atom on the right hand side.
[0016] The term “C 3 -C 7 cycloheteroalkyl” as used herein refers to a radical of totally saturated heterocycle like a cyclic hydrocarbon containing one or more heteroatoms selected from nitrogen, oxygen, phosphor, boron and sulphur independently in the cycle such as pyrrolidine (1-pyrrolidine; 2-pyrrolidine; 3-pyrrolidine; 4-pyrrolidine; 5-pyrrolidine); pyrazolidine (1-pyrazolidine; 2-pyrazolidine; 3-pyrazolidine; 4-pyrazolidine; 5-pyrazolidine); imidazolidine (1-imidazolidine; 2-imidazolidine; 3-imidazolidine; 4 imidazolidine; 5-imidazolidine); thiazolidine (2-thiazolidine; 3-thiazolidine; 4-thiazolidine; 5-thiazolidine); piperidine (1-piperidine; 2-piperidine; 3-piperidine; 4-piperidine; 5-piperidine; 6-piperidine); piperazine (1-piperazine; 2-piperazine; 3-piperazine; 4-piperazine; 5-piperazine; 6-piperazine); morpholine (2-morpholine; 3-morpholine; 4-morpholine; 5-morpholine; 6-morpholine); thiomorpholine (2-thiomorpholine; 3-thiomorpholine; 4-thiomorpholine; 5-thiomorpholine; 6-thiomorpholine); 1,2-oxathiolane (3-(1,2-oxathiolane); 4-(1,2-oxathiolane); 5-(1,2-oxathiolane); 1,3-dioxolane (2-(1,3-dioxolane); 4-(1,3-dioxolane); 5(1,3dioxolane); tetrahydropyrane; (2-tetrahydropyrane; 3-tetrahydropyrane; 4-tetrahydropyrane; 5-tetrahydropyrane; 6-tetrahydropyrane); hexahydropyridazine (1-(hexahydropyridazine); 2-(hexahydropyndazine); 3-(hexahydropyridazine); 4-(hexahydropyridazine); 5-(hexahydropyridazine); 6-(hexahydropyridazine)), [1,3,2]dioxaborolane, [1,3,6,2]dioxazaborocane
[0017] The term “aryl” as used herein includes carbocyclic aromatic ring systems of 5-7 carbon atoms. Aryl is also intended to include the partially hydrogenated derivatives of the carbocyclic systems as well as up to four fused fused aromatic- or partially hydrogenated rings, each ring comprising 5-7 carbon atoms.
[0018] The term “heteroaryl” as used herein includes heterocyclic unsaturated ring systems containing, in addition to 2-18 carbon atoms, one or more heteroatoms selected from nitrogen, oxygen and sulphur such as furyl, thienyl, pyrrolyl, heteroaryl is also intended to include the partially hydrogenated derivatives of the heterocyclic systems enumerated below.
[0019] The terms “aryl” and “heteroaryl” as used herein refers to an aryl which can be optionally substituted or a heteroaryl which can be optionally substituted and includes phenyl, biphenyl, indenyl, naphthyl (1-naphthyl, 2-naphthyl), N-hydroxytetrazolyl, N-hydroxytriazolyl, N-hydroxyimidazolyl, anthracenyl (1-anthracenyl, 2-anthracenyl, 3-anthracenyl), thiophenyl (2-thienyl, 3-thienyl), furyl (2-furyl, 3-furyl), indolyl, oxadiazolyl, isoxazolyl, quinazolinyl, fluorenyl, xanthenyl, isoindanyl, benzhydryl, acridinyl, thiazolyl, pyrrolyl (2-pyrrolyl), pyrazolyl (3-pyrazolyl), imidazolyl (1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl), triazolyl (1,2,3-triazol-1-yl, 1,2,3-triazol-2-yl 1,2,3-triazol-4-yl, 1,2,4-triazol-3-yl), oxazolyl (2-oxazolyl, 4-oxazolyl, 5-oxazolyl), thiazolyl (2-thiazolyl, 4-thiazolyl, 5-thiazolyl), pyridyl (2-pyridyl, 3-pyridyl, 4-pyridyl), pyrimidinyl (2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6pyrimidinyl), pyrazinyl, pyridazinyl (3-pyridazinyl, 4-pyridazinyl, 5-pyridazinyl), quinolyl (2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6 quinolyl, 7-quinolyl, 8-quinolyl), isoquinolyl (1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl), benzo[b]furanyl (2-benzo[b]furanyl, 3-benzo[b]furanyl, 4-benzo[b]furanyl, 5-benzo[b]furanyl, 6-benzo[b]furanyl, 7-benzo[b]furanyl), 2,3-dihydro-benzo[b]furanyl (2-(2,3-dihydro-benzo[b]furanyl), 3-(2,3-dihydro-benzo[b]furanyl), 4-(2,3-dihydro-benzo[b]furanyl), 5-(2,3-dihydro-benzo[b]furanyl), 6-(2,3-dihydro-benzo[b]furanyl), 7-(2,3-dihydro-benzo[b]furanyl), benzo[b]thiophenyl (2-benzo[b]thiophenyl, 3-benzo[b]thiophenyl, 4-benzo[b]thiophenyl, 5-benzo[b]thiophenyl, 6-benzo[b]thiophenyl, 7-benzo[b]thiophenyl), 2,3-dihydro-benzo[b]thiophenyl (2-(2,3-dihydro-benzo[b]thiophenyl), 3-(2,3-dihydro-benzo[b]thiophenyl), 4-(2,3-dihydro-benzo[b]thiophenyl), 5-(2,3-dihydro-benzo[b]thiophenyl), 6-(2,3-dihydro-benzo[b]thiophenyl), 7-(2,3-dihydro-benzo[b]thiophenyl), indolyl (1-indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl), indazole (1-indazolyl, 3-indazolyl, 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl), benzimidazolyl (1-benzimidazolyl, 2-benzimidazolyl, 4-benzimidazolyl, 5-benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, 8-benzimidazolyI), benzoxazolyl (1-benzoxazolyl, 2-benzoxazolyl), benzothiazolyl (1-benzothiazolyl, 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyl, 6-benzothiazolyl, 7-benzothiazolyl), carbazolyl (1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl), 5H-dibenz[b,f]azepine (5H-dibenz[b,f]azepin-1-yl, 5H-dibenz[b,f]azepine-2-yl, 5H-dibenz[b,f]azepine-3-yl, 5H-dibenz[b,f]azepine-4-yl, 5H-dibenz[b,f]azepine-5-yl), 10,11-dihydro-5H-dibenz[b,f]azepine (10,11-dihydro-5H-dibenz[b,f]azepine-1-yl, 10,11-dihydro-5H-dibenz[b,f]azepine-2-yl, 10,11-dihydro-5H-dibenz[b,f]azepine-3-yl, 10,11 -dihydro-5H-dibenz[b,f]azepine-4-yl, 10,11-dihydro-5H-dibenz[b,f]azepine-5-yl).
[0020] The Functional Entity carries elements used to interact with host molecules and optionally reactive elements allowing further elaboration of an encoded molecule of a library. Interaction with host molecules like enzymes, receptors and polymers is typically mediated through van der waal's interactions, polar- and ionic interactions and pi-stacking effects. Substituents mediating said effects may be masked by methods known to an individual skilled in the art (Greene, T. W.; Wuts, P. G. M. Protective Groups in Organic Synthesis; 3rd ed.; John Wiley & Sons: New York, 1999.) to avoid undesired interactions or reactions during the preparation of the individual building blocks and during library synthesis. Analogously, reactive elements may be masked by suitably selected protection groups. It is appreciated by one skilled in the art that by suitable protection, a functional entity may carry a wide range of substitutents.
[0021] The Functional Entity Precursor is a masked. Functional Entity that is incorporated into an encoded molecule. After incorporation, reactive elements of the Functional Entity may be revealed by un-masking allowing further synthetic operations. Finally, elements mediating recognition of host molecules may be un-masked.
[0022] In a certain aspect of the invention, Functional entity precursor is —C(H)(R 11 )—R 11 ′ or functional entity precursor is heteroaryl or aryl substituted with 0-3 R 11 , 0-3 R 13 and 0-3 R 15 , wherein
[0023] R 11 and R 11 ′ are independently H, or selected among the group consisting of a C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 8 alkynyl, C 4 -C 8 alkadienyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cyclo-heteroalkyl, aryl, and heteroaryl, said group being substituted with 0-3 R 12 , 0-3 R 13 and 0-3 R 15 ,
[0024] or R 11 and R 11 ′ 0 are C 1 -C 3 alkylene-NR 12 2 , C 1 -C 3 alkylene-NR 12 C(O)R 16 , C 1 -C 3 alkylene-NR 12 C(O)OR 16 , C 1 -C 2 alkylene-O—NR 12 2 , C 1 -C 2 alkylene-O—NR 12 C(O)R 16 , C 1 -C 2 alkylene-O—NR 12 C(O)OR 16 substituted with 0-3 R 15 ,
where R 12 is H or selected independently among the group consisting of C 1 C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl, heteroaryl, said group being substituted with 0-3 R 13 and 0-3 R 15 , R 13 is selected independently from —N 3 , —CNO, —C(NOH)NH 2 , —NHOH, —NHNHR 17 , —C(O)R 17 , —SnR 17 3 , —B(OR 17 ) 2 , —P(O)(OR 17 ) 2 or the group consisting of C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 4 -C 8 alkadienyl said group being substituted with 0-2 R 14 , where R 14 is independently selected from —NO 2 , —C(O)OR 17 , —COR 17 , —CN, —OSiR 17 3 , —OR 17 and —NR 17 2 ; R 15 is ═O, —F, —Cl, —Br, —I, —CN, —NO 2 , —OR 17 , —NR 17 2 , —NR 17 —C(O)R 16 , —NR 17 —C(O)OR 16 , —SR 17 , —S(O)R 17 , —S(O) 2 R 17 , —COOR 17 , —C(O)NR 17 2 and —S(O) 2 NR 17 2 , R 16 is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 7 cycloalkyl, aryl or C 1 -C 6 alkylene-aryl substituted with 0-3 substituents independently selected from —F, —Cl, —NO 2 , —R 2 , —R 2 , —SiR 2 3 ;
[0030] R 17 is selected independently from H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, aryl, C 1 -C 6 alkylene-aryl,
G is H or C 1 -C 6 alkyl and n is 1,2,3 or 4.
[0031] The function of the carrier is to ensure the transferability of the functional entity precursor. To adjust the transferability a skilled chemist can design suitable substitutions of the carrier by evaluation of initial attempts. The transferability may be adjusted in response to the chemical composition of the functional entity precursor, to the nature of the complementing element, to the conditions under which the transfer and recognition is performed, etc.
[0032] In a preferred embodiment, the carrier is selected from the group consisting of arylene, heteroarylene or —(CF 2 ) m — substituted with 0-3 R 1 wherein m is an integer between 1 and 10, and C—F-connecting group is —SO 2 —O—. Due to the high reactivity of such compounds a broad range of recipient reactive groups may be employed in the construction of carbon-carbon bonds or carbon-hetero atom bonds.
[0033] In another preferred embodiment of the invention, the carrier is —(CF 2 ) m — wherein m is an integer between 1 and 10, the C—F-connecting group is —SO 2 —O—; and the functional entity precursor is aryl or heteroaryl substituted with 0-3 R 11 , 0-3 R 13 and 0-3 R 15 .
[0034] The C—F-connecting group determines in concert with the carrier the transferability of the functional entity precursor. In a preferred embodiment, the C—F-connecting group is —S + (R 11 )—,
[0035] In another preferred embodiment, the C—F-connecting group is chosen from the group consisting of —SO 2 —O—, and —S + (R 17 )—; wherein R 17 is selected independently from H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, aryl, C 1 -C 6 alkylene-aryl.
[0036] In the presence of a catalyst comprising transition metals such as Pd, Ni or Cu, an aromatic moiety may be transferred from the C—F-connecting group to a recipient reactive group. Further, the transfer may be initiated by adding the catalyst, independently of the annealing of encoding - and complementing elements.
[0037] The S—C-connecting group provide a means for connecting the Spacer and the Carrier. As such it is primarily of synthetic convenience and does not influence the function of a building block.
[0038] The spacer serves to distance the functional entity precursor to be transferred from the bulky complementing element. Thus, when present, the identity of the spacer is not crucial for the function of the building block. It may be desired to have a spacer which can be cleaved by light. In this case, the spacer is provided with e.g. the group
[0039] In the event an increased hydrophilicity is desired the spacer may be provided with a polyethylene glycol part of the general formula:
[0040] In a preferred embodiment, the complementing element serves the function of transferring genetic information e.g. by recognising a coding element. The recognition implies that the two parts are capable of interacting in order to assemble a complementing element—coding element complex. In the biotechnological field a variety of interacting molecular parts are known which can be used according to the invention. Examples include, but are not restricted to protein-protein interactions, protein-polysaccharide interactions, RNA-protein interactions, DNA-DNA interactions, DNA-RNA interactions, RNA-RNA interactions, biotin-streptavidin interactions, enzyme-ligand interactions, antibody-ligand interaction, protein-ligand interaction, etc.
[0041] The interaction between the complementing element and coding element may result in a strong or a weak bonding. If a covalent bond is formed between the parties of the affinity pair the binding between the parts can be regarded as strong, whereas the establishment of hydrogen bondings, interactions between hydrophobic domains, and metal chelation in general results in weaker bonding. In general relatively weak bonding is preferred. In a preferred aspect of the invention, the complementing element is capable of reversible interacting with the coding element so as to provide for an attachment or detachment of the parts in accordance with the changing conditions of the media.
[0042] In a preferred aspect of the invention, the interaction is based on nucleotides, i.e. the complementing element is a nucleic acid. Preferably, the complementing element is a sequence of nucleotides and the coding element is a sequence of nucleotides capable of hybridising to the complementing element. The sequence of nucleotides carries a series of nucleobases on a backbone. The nucleobases may be any chemical entity able to be specifically recognized by a complementing entity. The nucleobases are usually selected from the natural nucleobases (adenine, guanine, uracil, thymine, and cytosine) but also the other nucleobases obeying the Watson-Crick hydrogen-bonding rules may be used, such as the synthetic nucleobases disclosed in U.S. Pat. No. 6,037,120. Examples of natural and non-natural nucleobases able to perform a specific pairing are shown in FIG. 2 . The backbone of the sequence of nucleotides may be any backbone able to aggregate the nucleobases is a sequence. Examples of backbones are shown in FIG. 4 . In some aspects of the invention the addition of non-specific nucleobases to the complementing element is advantegeous, FIG. 3
[0043] The coding element can be an oligonucleotide having nucleobases which complements and is specifically recognised by the complementing element, i.e. in the event the complementing element contains cytosine, the coding element part contains guanine and visa versa, and in the event the complementing element contains thymine or uracil the coding element contains adenine.
[0044] The complementing element may be a single nucleobase. In the generation of a library, this will allow for the incorporation of four different functional entities into the template-directed molecule. However, to obtain a higher diversity a complementing element preferably comprises at least two and more preferred at least three nucleotides. Theoretically, this will provide for 42 and 43, respectively, different functional entities uniquely identified by the complementing element. The complementing element will usually not comprise more than 100 nucleotides. It is preferred to have complementing elements with a sequence of 3 to 30 nucleotides.
[0045] The building blocks of the present invention can be used in a method for transferring a functional entity precursor to a recipient reactive group, said method comprising the steps of
providing one or more building blocks as described above and contacting the one or more building blocks with a corresponding encoding element associated with a recipient reactive group under conditions which allow for a recognition between the one or more complementing elements and the encoding elements, said contacting being performed prior to, simultaneously with, or subsequent to a transfer of the functional entity precursor to the recipient reactive group.
[0048] The encoding element may comprise one, two, three or more codons, i.e. sequences that may be specifically recognised by a complementing element. Each of the codons may be separated by a suitable spacer group. Preferably, all or at least a majority of the codons of the template are arranged in sequence and each of the codons are separated from a neighbouring codon by a spacer group. Generally, it is preferred to have more than two codons on the template to allow for the synthesis of more complex encoded molecules. In a preferred aspect of the invention the number of codons of the encoding element is 2 to 100. Still more preferred are encoding elements comprising 3 to 10 codons. In another aspect, a codon comprises 1 to 50 nucleotides and the complementing element comprises a sequence of nucleotides complementary to one or more of the encoding sequences.
[0049] The recipient reactive group may be associated with the encoding element in any appropriate way. Thus, the reactive group may be associated covalently or noncovalently to the encoding element. In one embodiment the recipient reactive group is linked covalently to the encoding element through a suitable linker which may be separately cleavable to release the reaction product. In another embodiment, the reactive group is coupled to a complementing element, which is capable of recognising a sequence of nucleotides on the encoding element, whereby the recipient reactive group becomes attached to the encoding element by hybridisation. Also, the recipient reactive group may be part of a chemical scaffold, i.e. a chemical entity having one or more reactive groups available for receiving a functional entity precursor from a building block.
[0050] The recipient reactive group may be any group able to participate in cleaving the bond between the carrier and the functional entity precursor to release the functional entity precursor. Typically, the recipient reactive group is a nucleophilic atom such as S, N, 0, C or P. Scheme 1a shows the transfer of an alkyl group and scheme 1b shows the transfer of an vinyl group.
[0051] Alternatively, the recipient reactive group is a organometallic compound as shown in scheme 2.
[0052] According to a preferred aspect of the invention the building blocks are used for the formation of a library of compounds. The complementing element of the building block is used to identify the functional entity. Due to the enhanced proximity between reactive groups when the complementing entity and the encoding element are contacted, the functional entity precursor together with the identity programmed in the complementing element is transferred to the encoding element associated with recipient reactive group. Thus, it is preferred that the sequence of the complementing element is unique in the sense that the same sequence is not used for another functional entity. The unique identification of the functional entity enable the possibility of decoding the encoding element in order to determine the synthetic history of the molecule formed. In the event two or more functional entities have been transferred to a scaffold, not only the identity of the transferred functional entities can be determined. Also the sequence of reaction and the type of reaction involved can be determined by decoding the encoding element. Thus, according to a preferred embodiment of the invention, each different member of a library comprises a complementing element having a unique sequence of nucleotides, which identifies the functional entity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 . Two setups for Functional Entity Transfer
[0054] FIG. 2 . Examples of specific base pairing
[0055] FIG. 3 . Example of non-specific base-pairing
[0056] FIG. 4 . Backbone examples
[0057] FIG. 5 Three examples of building blocks
DETAILED DESCRIPTION OF THE INVENTION
[0058] A building block of the present invention is characterized by its ability to transfer its functional entity precursor to a recipient reactive group. This is done by forming a new covalent bond between the recipient reactive group and cleaving the bond between the carrier moiety and the functional entity precursor of the building block.
[0059] Two setups for generalized functional entity precursor transfer from a building block are depicted in FIG. 1 . In the first example, one complementing element of a building block recognizes a coding element carrying another functional entity precursor, hence bringing the functional entities in close proximity. This results in a reaction between functional entity precursor 1 and 2 forming a covalent bond between these concurrent with the cleavage of the bond between functional entity precursor 2 and its linker. In the second example, a template brings together two building blocks resulting in functional entity precursor transfer from one building block to the other.
[0060] FIG. 5 illustrates three specific compounds according to the invention. For illustrative purposes the individual features used in the claims are indicated. The upper compound is an example of a building block wherein the linker is backbone attached at the 3′-position. The first part of the linker, i.e. the spacer, is an aliphatic chain ending in a nitrogen atom. The nitrogen atom bridges to the S—C-connecting group, which is an N-acylated arylmethyleamine. The carrier attached to the left hand side carbonyl group of the S—C-connecting group is a benzene ring holding the C—F Connecting group in the para position. The C—F Connecting group is a positively charged sulfur atom which is attached to the Functional Entity Precursor, in this case a benzyl group. When the building block is presented to a nucleophilic recipient reactive group, such an amine or a thiol, Functional Entity Precursor is transferred to benzylate the recipient reactive group.
[0061] The middle compound illustrates a 5′ 0 attachment of a linker. The linker is linked through a phosphate group and extends into a three membered aliphatic chain. Through another phosphate group and a PEG linker the complementing element is linked via an amide bond to the Carrier. When the building block is presented to a nucleophile the Functional Entity Precursor is transferred resulting in an alkylation of the nucleophile.
[0062] The lower compound illustrates a nucleobase attachment of the linker. The linker attaches to the 5 position of a pyrimidine type nucleobase and extents through an α-β unsaturated N-methylated amide to the S—C-connecting group, which is a 4-amino methyl benzoic acid derivative. The functional entity precursor can be transferred to a nucleophilic recipient reactive group e.g. an amine or a thiol forming an allylic amine or thiol.
[0063] According to the invention, the functional entity precursor is of the formula —C(H)(R 3 )—R 4 or functional entity precursor is heteroaryl or aryl optionally substituted with one or more substituents belonging to the group comprising R 3 and R 4 . In a further preferred embodiment,
[0064] R 3 and R 4 independently is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 4 -C 8 alkadienyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl, optionally substituted with one or more substituents selected from the group consisting of
[0065] SnR 5 R 6 , R 7 , Sn(OR 5 )R 6 R 7 , Sn(OR 5 )(OR 6 )R 7 , BR 5 R 6 , B(OR 5 )R 6 , B(OR 5 )(OR 6 ), halogen, CN, CNO, C(halogen) 3 , ═O, OR 5 , OC(═O)R 5 , OC(═O)OR 5 , OC(═O)NR 5 R 6 , SR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , N 3 , NR 5 R 6 , N + R 5 R 6 R 7 , NR 5 OR 6 , NR 5 NR 6 R 7 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , NC, P(═O)(OR 5 )OR 6 , P + R 5 R 6 R 7 , C(═O)R 5 , C(═NR 5 )R 6 , C(═NOR 5 )R 6 , C(═NNR 5 R 6 ), C(═O)OR, C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 , C(═O)NR 5 NR 6 R 7 , C(═NR 5 )NR 6 R 7 , C(═NOR 5 )NR 6 R 7 or R 8 , wherein,
[0066] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 4 -C 8 alkadienyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0067] in another prefered embodiment,
[0068] R 3 and R 4 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl, optionally substituted with one or more substituents selected from the group consisting of halogen, CN, C(halogen) 3 , ═O, OR 5 , OC(═O)R 5 , OC(═O)OR 5 , OC(═O)NR 5 R 6 , SR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 OR 6 , NR5NR 6 R 7 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , P(═O)(OR5)OR 6 , C(═O)R 5 , C(═NR 5 )R 6 , C(═NOR 5 )R 6 , C(═NNR 5 R 6 ), C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 , C(═O)NR 5 NR 6 R 7 , C(═NR 5 )NR 6 R 7 , C(═NOR 5 )NR 6 R 7 or R 8 , wherein,
[0069] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0070] in still another prefered embodiment,
[0071] R 3 and R 4 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl, optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , OC(═O)R 5 , OC(═O)OR 5 , OC(═O)NR 5 R 6 , SR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 R 6 , NR 5 NR 6 R 7 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , P(═O)(OR 5 )OR 6 , C(═O)R 6 , C(═NR 5 )R 6 , C(═NOR 5 )R 6 , C(═NNR 5 R 6 ), C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 , C(═O)NR 5 NR 6 R 7 , C(═NR 5 )NR 6 R 7 , C(═NOR 5 )NR 6 R 7 or R 8 , wherein,
[0072] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0073] in still another prefered embodiment,
[0074] R 3 and R 4 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl, optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0075] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0076] in still another prefered embodiment,
[0077] R 3 and R 4 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl, morpholinyl, phenyl, naphtyl, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0078] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0079] in still another prefered embodiment,
[0080] R 3 and R 4 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0081] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 6 and R5 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0082] in still another prefered embodiment,
[0083] R 3 and R 4 independently is H, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0084] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 38 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0085] in still another prefered embodiment,
[0086] R 3 and R 4 independently is H, phenyl, naphtyl, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 5 , wherein,
[0087] R 5 , R 6 , R 7 and R 3 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0088] in still another prefered embodiment,
[0089] R 3 and R 4 independently is H, phenyl or naphtyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0090] R 5 , R 6 , R 7 and R 8 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0091] in still another prefered embodiment,
[0092] R 3 and R 4 independently is H, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , R 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0093] R 5 , R 6 , R 7 and R 5 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0094] in still another prefered embodiment,
[0095] R 3 and R 4 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6, NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0096] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0097] in still another prefered embodiment,
[0098] R 3 and R 4 independently is H, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0099] R 5 , R 6, R 7 and R 8 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0100] in still another prefered embodiment,
[0101] R 3 and R 4 independently is H, phenyl, naphtyl, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 s, S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NRBR 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0102] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0103] in still another prefered embodiment,
[0104] R 3 and R 4 independently is H, phenyl or naphtyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0105] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0106] in still another prefered embodiment,
[0107] R 3 and R 4 independently is H, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 6 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0108] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl and wherein R 5 and R 6 may together form a 38 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0109] in still another prefered embodiment,
[0110] R 3 and R 4 independently is H, methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0111] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl or butyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0112] in still another prefered embodiment,
[0113] R 3 and R 4 independently is H, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NRR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0114] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl or butyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0115] in still another prefered embodiment,
[0116] R 3 and R 4 independently is H, phenyl, naphtyl, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0117] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl or butyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0118] in still another prefered embodiment,
[0119] R 3 and R 4 independently is H, phenyl or naphtyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 ,═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0120] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl or butyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0121] in still another prefered embodiment,
[0122] R 3 and R 4 independently is H, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 6 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0123] R 5 , R 6 , R 7 and R 8 independently is H, methyl, ethyl, propyl or butyl and wherein R 5 and R 6 may together form a 3-8 membered heterocyclic ring or R 5 and R 7 may together form a 3-8 membered heterocyclic ring or R 6 and R 7 may together form a 3-8 membered heterocyclic ring,
[0124] in still another prefered embodiment,
[0125] R 3 and R 4 independently is methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 6 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 6 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0126] R 5 , R 6 , R 7 and R 8 independently is H, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl,
[0127] in still another prefered embodiment,
[0128] R 3 and R 4 independently is aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein, R 5 , R 6 , R 7 and R 8 independently is H, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl,
[0129] in still another prefered embodiment,
[0130] R 3 and R 4 independently is phenyl, naphtyl, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0131] R 5 , R 6 , R 7 and R 8 independently is H, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl,
[0132] in still another prefered embodiment,
[0133] R 3 and R 4 independently is phenyl or naphtyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0134] R 5 , R 8 , R 7 and R 8 independently is H, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl,
[0135] in still another prefered embodiment,
[0136] R 3 and R 4 independently is thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0137] R 5 , R 6 , R 7 and R 8 independently is H, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl,
[0138] in still another prefered embodiment,
[0139] R 3 and R 4 independently is methyl, ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0140] R 5 , R 6 , R 7 and R 8 independently is H, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl,
[0141] in still another prefered embodiment,
[0142] R 3 and R 4 independently is aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl or morpholinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0143] R 5 , R 6 , R 7 and R 8 independently is H, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl,
[0144] in still another prefered embodiment,
[0145] R 3 and R 4 independently is phenyl, naphtyl, thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0146] R 5 , R 6 , R 7 and R 8 independently is H, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl,
[0147] in still another prefered embodiment,
[0148] R 3 and R 4 independently is phenyl or naphtyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 6 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0149] R 5 , R 6 , R 7 and R 8 independently is H, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl,
[0150] in still another prefered embodiment,
[0151] R 3 and R 4 independently is thienyl, furyl, pyridyl, quinolinyl or isoquinolinyl optionally substituted with one or more substituents selected from the group consisting of F, Cl, CN, CF 3 , ═O, OR 5 , S(═O)R 5 , S(═O) 2 R 5 , S(═O) 2 NR 5 R 6 , NO 2 , NR 5 R 6 , NR 5 C(═O)R 5 , NR 5 C(═O)OR 6 , NR 5 C(═O)NR 6 R 7 , C(═O)R 5 , C(═NOR 5 )R 6 , C(═O)OR 5 , C(═O)NR 5 R 6 , C(═O)NR 5 OR 6 or R 8 , wherein,
[0152] R 5 , R 6 , R 7 and R 8 independently is H, phenyl, naphthyl, thienyl, furyl, pyridinyl, quinolinyl or isoquinolinyl,
[0153] in still another prefered embodiment,
[0154] R 3 and R 4 independently is H, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloheteroalkyl, aryl or heteroaryl
[0155] in still another prefered embodiment,
[0156] R 3 and R 4 independently is H,
[0157] in still another prefered embodiment,
[0158] R 3 and R 4 independently is C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or C 3 -C 7 cycloheteroalkyl,
[0159] in still another prefered embodiment,
[0160] R 3 and R 4 independently is methyl, ethyl, propyl or butyl
[0161] in still another prefered embodiment
[0162] R 3 and R 4 independently is cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl
[0163] in still another prefered embodiment
[0164] R 3 and R 4 independently is aziridinyl, pyrrolidinyl, piperidinyl or morpholinyl
[0165] in still another prefered embodiment,
[0166] R 3 and R 4 independently is aryl or heteroaryl
[0167] in still another prefered embodiment,
[0168] R 3 and R 4 independently is phenyl or naphthyl
[0169] in still another prefered embodiment,
[0170] R 3 and R 4 independently is thienyl, furyl, pyridyl, quinolinyl or isoquinolyl
[0000] Experimental Section
[0171] General Procedure 1: Preparation of Carrier-Functional Entity Reagents:
[0172] The 4-halobenzoic acid (25 mmol) is added to a ice cooled solution of chloro sulfonic acid (140 mmol). The mixture is slowly heated to reflux and left at reflux for 2-3 hours. The mixture is added to 100 mL ice and the precipitate collected by filtration. The filtrate is washed with water (2×50 mL) and the dried in vacuo affording the corresponding sulfonoyl chloride in 60-80% yield. The 3-chlorosulfonyl-4-halo-benzoic acid derivate (5 mmol) is dissolved in EtOH (5 mL) and added to a ice cooled mixture of NaOEt (10 mL, 2M). The mixture is stirred o/n at rt. Acetic acid (40 mmol) is added and the mixture is evaporated in vacuo. Water (10 mL) is added and pH adjusted to pH=2 (using 1M HCl). The product is extracted with DCM (2×25 mL), dried over Na 2 SO 4 and evaporated in vacuo affording the desired products.
EXAMPLE 1
General Procedure (1)
[0173] 3-Ethoxysulfonyl4-fluorobenzoic acid
[0174] 1 H-NMR (DMSO-d 6 ): δ 8.49 (d, 1H), 7.85 (dd, 1H), 7.5 (d, 1H), 4.32 (q, 2H), 1.32 (t, 3H)
EXAMPLE 2
General Procedure (1)
[0175] 4-chloro-3-Ethoxysulfonylbenzoic acid
[0176] 1 H-NMR (DMSO-d 6 ): δ 8.49 (d, 1H), 7.85 (dd, 1H), 7.5 (d, 1H), 4.32 (q, 2H), 1.32 (t, 3H)
EXAMPLE 3
[0177]
[0178] 4-Methylsulfanyl benzoic acid (0.5 g, 2.97 mmol, commercially available from Aldrich, cat no. 145521) was added to methyl p-toluene solfunate (0.61 g, 3.27 mmol). The mixture was heated to 140° C. for 1 hour in a sealed vessel. After cooling to rt the mixture was trituated with diethyl ether. Filtration and drying in vacuo yielded 844 mg (80%) of the desired product (>95% pure by 1 H nmr).
[0179] 1 H nmr (DMSO-d6): 8.20-8.10 (m, 4H), 7.45 (d, 2H), 7.08 (d, 2H), 3.29 (s, 6H), 2.30 (s, 3H).
General Procedure 2: Solid Phase Preparation of Carrier-Functional Entity Reagents for Alkylation Building Blocks:
[0180] Ps=Polystyrene resin. Alternatively other acid labile linkers may be employed.
[0000] Step 1:
[0181] A polystyrene resin with a wang linker (4-hydroxymethylphenol linker)(50 mg˜50 umol), a bi-functional carrier (200 umol, 4 equiv) in a solvent such as THF, DCM, DCE, DMF, NMP or a mixture thereof (500 uL) and a base such as TEA, DIEA, pyridine (400 umol, 8 equiv), optionally in the presence of DMAP (100 umol), are allowed to react at temperatures between −20° C. and 60° C., preferably between 0° C. and 25° C., for 1-24 h, preferably 14 h. The resin is washed with the solvent composition used during the reaction (5×1 mL) and used in the following step.
[0000] Step 2:
[0182] A functional entity precursor carrying a hydroxy group in the position of the intended attachment to the C—F-connecting group (200 umol, 4 equiv) in a solvent such as THF, DCM, DCE, DMF, NMP or a mixture thereof (500 uL) and a base such as TEA, DIEA, pyridine (400 umol, 8 equiv), optionally in the presence of DMAP, are added to the resin bound carrier isolated in step 1 and allowed to react at temperatures between 0° C. and 100° C., preferably between 25° C. and 80° C., for 248 h, preferably. 4-16 h. The resin is washed with the solvent composition used during the reaction (5×1 mL).
[0000] Step 3:
[0183] The desired Carrier-Functional entity reagent is cleaved from the resin obtained in step 2 by treatment with an acid like TFA, HF or HCl in a solvent such as THF, DCM, DCE or a mixture thereof (1 mL) at temperatures between −20° C. and 60° C., preferably between 0° C. and 25° C., for 14 h, preferably 1-2 h. Upon filtration, the resin is washed with the solvent composition used during cleavage (2×1 mL) and the combined filtrates are evaporated in vacuo. The isolated product may be purified by chromatography.
Assembly of Building Blocks
[0184] The Carrier-Functional entity reagent may be bound to the Spacer by several different reactions as illustrated below.
Formation of an Amide Bond Between a Carboxylic Acid of the Carrier and an Amine Group of a Spacer
[0185]
General Procedure 3: Preparation of Building Blocks by Loading a Carrier-Functional Entity Reagent onto a Nucleotide Derivative Comprising an Amino Group:
[0186] 15 uL of a 150 mM building block solution of FE 1 -Carrier-COOH is mixed with 15 μL of a 150 mM solution of EDC and 15 μL of a 150 mM solution of N-hydroxy-succinimide (NHS) using solvents like DMF, DMSO, water, acetonitril, THF, DCM, methanol, ethanol or a mixture thereof. The mixture is left for 15 min at 25° C. 45 μL of an aminooligo (10 nmol) in 100 mM buffer at a pH between 5 and 10, preferably 6.0-7.5 is added and the reaction mixture is left for 2 hours at 25° C. Excess building block and organic by-products were removed by extraction with EtOAc (400 μL). Remaining EtOAc is evaporated in vacuo using a speedvac. The building block is purified following elution through a BiORad micro-spin chromatography column, and analyzed by electron spray mass spectrometry (ES-MS).
EXAMPLE 4
General Procedure ( )
[0187]
[0188] Where Oligo is 5′ 0 XCG ATG GAT GCT CCA GGT CGC 3′, X=5′ amino C 6 (Glen catalogue# 10-1906-90), Expected molecular weight: 6313.22 MS (calc.)=6543,43; MS (found)=6513,68* * Observed molecular weight of the cleaved sulfonic ester: 6513.68 Expected molecular weight of the cleaved ester. 6514.37 The quantitative loss of the ethyl group Is probably due to the presence of pipeddine during the recording of the LCMS data.
[0000] General Procedure 4: Loading of a Carrier Coupled Functional Entity onto an Amino Ontgo:
[0189] 25 μl 100 mM carrier coupled functional entity dissolved in DMF (dimethyl formamide) was mixed with 25 μl 100 mM EDC (1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride) in DMF for 30 minutes at 25° C. The mixture was added to 50 μl amino oligo in H 2 O with 100 mM HEPES (2-[4-(2-hydroxy-ethyl)-piperazin-1-yl]-ethanesulfonic acid) pH 7.5 and the reaction was allowed to proceed for 20 minutes at 25° C. Unreacted carrier coupled functional entity was removed by extraction with 500 μl EtOAc (ethyl acetate), and the oligo was purified by gel filtration through a microspin column equilibrated with 100 mM MES (2-(N-morpholino) ethanesulfonic acid) pH 6.0.
[0190] Oligonucleotide used:
[0191] Oligo A: 5′-YACGATGGATGCTCCAGGTCGC
[0192] Y=Amino modifier C6 (Glen#10-1906)
EXAMPLE 5
General Procedure 4
[0193] Carrier—Functional Entity: (4-Carboxy-phenyl)-dimethyl-sulfonium
[0194] Mass: 6789.21 (observed using ES-MS), 6790.65 (calculated)
General Procedure 5: Preparation of Arylation Building Blocks:
Funtional Entity-OH is a phenol, n is an integer between 3 and 6.
Step 1
[0195] To a solution of the bis-sulfonylchloride (Ward, R. B.; J. Org. Chem.; 30; 1965; 3009-3011; Qiu, Weiming; Burton, Donald J.; J. Fluorine Chem.; 60; 1; 1993; 93100)(3 umol) in DMF, DMSO, acetonitril, THF or a mixture thereof (150 uL) is a phenolic functional entity in excess (1.05-1.8 mmol) in DMF, DMSO, acetonitril, THF or a mixture thereof (150 uL) added slowly at temperatures between −20° C. and 100° C. preferably at 0-50° C. in the presence of a base such as TEA, DIEA, pyridine, Na-HCO 3 or K 2 CO 3 .
[0000] Step2
[0196] The reaction mixture from step 1 is added to a solution of an aminooligo (10 nmol) in 100 mM buffer at a pH between 5 and 10, preferably 6.0-7.5 optionally in the presence of NHS. The reaction mixture is left for 2 hours at 25° C. Excess building block and organic by-products were removed by extraction with EtOAc (400 μL). Remaining EtOAc is evaporated in vacuo using a speedvac. The building aminooligo is purified following elution through a BiORad micro-spin chromatography column, and analyzed by electron spray mass spectrometry (ES-MS).
Use of Building Blocks
[0197] General Procedure 6: Alkylation of Oligonucleotide Derivatives Containing a Nucleophilic Recipient Group Using a Building Block of the Invention:
[0198] An oligonucleotide building block carrying functional entity FE 1 is combined at 2 μM final concentration with one equivalent of a complementary building block displaying a nucleophilic recipient group. Reaction proceeds at temperatures between 0° C. and 100° C. preferably between 15° C.-50° C. for 148 hours, preferably 10-20 hours in DMF, DMSO, water, acetonitril, THF, DCM, methanol, ethanol or a mixture thereof, pH buffered to 4-10, preferably 6-8. Organic by-products are removed by extraction with EtOAc, followed by evaporation of residual organic solvent for 10 min in vacuo. Pd catalyst is removed and oligonucleotides are isolated by eluting sample through a BiORad micro-spin chromatography column. Coupling efficiency is quantified by ES-MS analysis.
[0000] General Procedure 7: Transfer of Functional Entity from a Carrier Oligo to Recipient Reactive Group.
[0199] A carrier coupled functional entity oligo (Example 1)(250 pmol) was added to a scaffold oligo B (200 pmol) in 50 μl 100 mM MES, pH 6. The mixture was incubated overnight at 25° C. Subsequently, the mixture was purified by gel filtration using a microspin column equilibrated with H 2 O and transfer of the functional entity was verified by electron spray mass spectrometry (ES-MS). Transfer efficiency is expressed in percent and were calculated by dividing the abundance of scaffold oligo carrying transferred functional entities to total abundance of scaffold oligos (with and without transferred functional entities).
EXAMPLE 6
General Procedure 7
[0200]
[0201] Mass (“X”): 6583.97 (observed), 6583.31 (calculated). Abundance: 65.79 (arbitrary units)
[0202] Mass (“Y”): 6599.73 (observed), 6597.34 (calculated). Abundance: 29.23 (arbitrary units)
[0203] Mass (“Z”): 6789.36 (observed), 6790.65 (calculated)
[0204] Transfer efficiency calculated as: 29.23/ (29.23+65.79) ═0.3076˜31%
General Procedure 8: Arylation of Oligonucleotide Derivatives Containing a Nucleophilic Recipient Group Using a Building Block of the Invention:
[0205] An oligonucleotide building block carrying functional entity FE 1 is combined at 2 μM final concentration with one equivalent of a complementary building block displaying a nucleophilic recipient group. In the presence of a Pd catalyst, the reaction proceeds at temperatures between 0° C. and 100° C. preferably between 15° C.-50° C. for 1-48 hours, preferably 10-20 hours in DMF, DMSO, water, acetonitrile, THF, DCM, methanol, ethanol or a mixture thereof, pH buffered to 4-10, preferably 6-8. Organic by-products are removed by extraction with EtOAc, followed by evaporation of residual organic solvent for 10 min in vacuo. Pd catalyst is removed and oligonucleotides are isolated by eluting sample through a BiORad micro-spin chromatography column. Coupling efficiency is quantified by ES-MS analysis.
General Procedure 9: General Route to the Formation of Alkylating/Vinylating Monomer Building Blocks with a Thio-Succinimid S—C-Connecting Group and Use of These:
[0206] R 1 and R 2 may be used to tune the reactivity of the sulphate to allow appropriate reactivity. Chloro and nitro substitution will increase reactivity. Alkyl groups will decrease reactivity. Ortho substituents to the sulphate will due to steric reasons direct incoming nucleophiles to attack the R-group selectively and avoid attack on sulphur. E.g.
[0207] 3-Aminophenol (6) is treated with maleic anhydride, followed by treatment with an acid e.g. H 2 SO 4 or P 2 O 5 and heat to yield the maleimide (7). The ring closure to the maleimide may also be achieved when an acid stable O-protection group is used by treatment with or Ac 2 O with or without heating, followed by O-deprotection. Alternatively reflux in Ac 2 O, followed by O-deacetylation in hot water/dioxane to yield (7).
[0208] Further treatment of (7) with SO 2 Cl 2 with or without triethylamine or potassium carbonate in dichloromethane or a higher boiling solvent will yield the intermediate (8), which may be isolated or directly further transformed into the aryl alkyl sulphate by the quench with the appropriate alcohol, in this case MeOH, whereby (9) will be formed. The organic building block (9) may be connected to an oligo nucleotide, as follows.
[0209] A thiol carrying oligonucleotide in buffer 50 mM MOPS or hepes or phosphate pH 7.5 is treated with a 1-100 mM solution and preferably 7.5 mM solution of the organic building block (9) in DMSO or alternatively DMF, such that the DMSO/DMF concentration is 5-50%, and preferably 10%. The mixture is left for 1-16 h and preferably 24 h at 25° C. To give the alkylating in this case methylating monomer building block (10).
[0210] The reaction of the alkylating monomer building block (10) with an amine carrying monomer building block may be conducted as follows:
[0211] The coding oligonucleotide (1 nmol) is mixed with a thio oligonucleotide loaded with a building block (1 nmol)(10) and an amino-oligonucleotide (1 nmol) in hepes-buffer (20 μL of a 100 mM hepes and 1 M NaCl solution, pH=7.5) and water (39 uL). The oligonucleotides are annealed to the template by heating to 50° C. and cooled (2° C./second) to 30° C. The mixture is then left o/n at a fluctuating temperature (10° C. for 1 second then 35° C. for 1 second), to yield the template bound methylamine (11).
[0212] A vinylating monomer building block may be prepared and used similarily as described above for an alkylating monomer building block. Although instead of reacting the chlorosulphonate (8 above) with an alcohol, the intermediate chlorosulphate is isolated and treated with an enolate or O-trialkylsilylenolate with or without the presence of fluoride. E.g.
[0213] Formation of the vinylating monomer building block (13):
[0214] The thiol carrying oligonucleotide in buffer 50 mM MOPS or hepes or phosphate pH 7.5 is treated with a 1-100 mM solution and preferably 7.5 mM solution of the organic building block (12) in DMSO or alternatively DMF, such that the DMSO/DMF concentration is 5-50%, and preferably 10%. The mixture is left for 1-16 h and preferably 2-4 h at 25° C. To give the vinylating monomer building block (13).
[0215] The sulfonylenolate (13) may be used to react with amine carrying monomer building block to give an enamine (14a and/or 14b) or e.g. react with an carbanion to yield (15a and/or 15b). E.g.
[0216] The reaction of the vinylating monomer building block (13) and an amine or nitroalkyl carrying monomer building block may be conducted as follows:
[0217] The coding oligonucleotide (1 nmol) is mixed with a oligonucleotide building block (1 nmol)(13) and an amino-oligonucleotide (1 nmol) or nitroalkyl-oligonucleotide (1 nmol) in 0.1 M TAPS, phosphate or hepes-buffer and 300 mM NaCl solution, pH=7.5-8.5 and preferably pH=8.5. The oligonucleotides are annealed to the template by heating to 50° C. and cooled (2° C./second) to 30° C. The mixture is then left o/n at a fluctuating temperature (10° C. for 1 second then 35° C. for 1 second), to yield template bound (14a/b or 15a/b).
DCC N,N′-Dicyclohexylcarbodiimide DhbtOH 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine DIC Diisopropylcarbodiimide DIEA Diethylisopropylamin DMAP 4-Dimethylaminopyridine DNA Deoxyribosenucleic Acid EDC 1-Ethyl-3-(3′-dimethylaminopropyl)carbodiimide.HCl HATU 2-(1H-7-Azabenzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate HBTU 2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluoro-phosphate HOAt N-Hydroxy-7-azabenzotriazole HOBt N-Hydroxybenzotriazole LNA Locked Nucleic Acid NHS N-hydroxysuccinimid OTf Trifluoromethylsulfonate OTs Toluenesulfonate PNA Peptide Nucleic Acid PyBoP Benzotriazole-1-yl-oxy-tris-pyrrolidino-phosphonium hexafluoro-phosphate PyBroP Bromo-tris-pyrrolidino-phosphonium hexafluorophosphate RNA Ribonucleic acid TBTU 2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetra- fluoroborate TEA Triethylamine RP-HPLC Reverse Phase High Performance Liquid Chromatography TBDMS-Cl Tert-Butyldimethylsilylchloride 5-Iodo-dU 5-iodo-deoxyriboseuracil TLC Thin layer chromatography (Boc) 2 O Boc anhydride, di-tert-butyl dicarbonate TBAF Tetrabutylammonium fluoride SPDP Succinimidyl-propyl-2-dithiopyridyl | A building block having the dual capabilities of transferring genetic information and functional entity precursor to a recipient reactive group is disclosed. The building block may be used in the generation of a single complex or libraries of different complexes, wherein the complex comprises an encoded molecule linked to an encoding element. Libraries of complexes are useful in the quest for pharmaceutically active compounds. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The benefit of the filing date of provisional Application Serial No. 60/359,638, filed on Feb. 25, 2002, is hereby claimed for this application under 35 U.S.C. §119(e).
FIELD OF THE INVENTION
[0002] This invention relates generally to distributed radio systems and, more particularly, to an indoor system with multiple transceivers for simulcasting and selective processing of received signals.
BACKGROUND OF THE INVENTION
[0003] Wireless (e.g., cellular) operators are faced with the continuing challenge of expanding the coverage areas of their systems, while at the same time adhering to cost, power, and frequency limitations. One area for expanding coverage is in indoor environments. However, it is also desired that such systems not interfere with the existing macrocellular environment, even if operating in the same frequency band for a given cellular standard.
[0004] The present invention is directed to providing a system and method that can be operated at low power levels and which cause minimal interference with the existing macrocellular environment. More specifically, the present invention is directed to a system and method in which multiple transceivers are utilized in an indoor system and which are able to each effectively transmit signals to a mobile unit at low power levels by utilizing a simulcasting technique.
SUMMARY OF THE INVENTION
[0005] A distributed radio system with multiple transceivers for communicating with mobile units via simulcasting and selective processing of received signals is disclosed. In accordance with one aspect of the invention, the system transmits at very low power levels. Due to the use of the low power levels, the system does not tend to interfere with the existing macrocellular environment.
[0006] In accordance with another aspect of the invention, the system utilizes relatively few frequency channels. The system is able to provide large geographical coverage with relatively few channels, while transmitting at low power levels, by simulcasting identical radio frequency signals from several different radio transmitters distributed within a building or similar area using the limited number of frequency channels. This allows the system to cover a relatively large indoor installation. Furthermore, as noted above, the system interferes very little with the existing macrocellular environment, even though the same frequency band for a given cellular standard is being used, given that the system is able to operate at very low power levels by utilizing the simulcast technique.
[0007] In accordance with another aspect of the invention, in one embodiment the distributed radio system includes a plurality of processing elements and radio frequency transmitter elements interconnected by an Ethernet network (e.g., the IEEE 802). The distributed radio system simulcasts a common modulating signal on a common radio frequency carrier, using at least two radio frequency transmitter elements. A set of radio frequency transmitter elements, which simulcast a common modulated radio frequency signal, are designated as a radio frequency simulcast set. In operation, the elements of a radio frequency simulcast set are configured to receive Ethernet sampled signal packets and transmit the information contained in the packets by modulating their radio frequency carrier.
[0008] In accordance with another aspect of the invention, in one embodiment the simulcast method designates a number of particular radio frequency transmitter elements to be elements of a radio frequency simulcast set. A first set of Ethernet packets is transmitted to be received by the elements of the radio frequency simulcast set. The first set of Ethernet packets is used to program the elements of the radio frequency simulcast set with a multicast address. The elements of the radio frequency simulcast set are thereafter responsive to Ethernet packets containing the multicast address as the designation media access control (MAC) address. A second set of Ethernet packets is transmitted to be received by the elements of the radio frequency simulcast set. The second set of Ethernet packets is used to program the elements of the radio frequency simulcast set to operate using a particular common radio frequency carrier. In addition, Ethernet sampled signal packets are periodically transmitted. The Ethernet sampled signal packets contain a designation address, which is equivalent to the programmed multicast address. The elements of the radio frequency simulcast set are configured to receive the Ethernet sampled signal packets. The elements of the radio frequency simulcast set modulate the common radio frequency carrier in accordance with sampled data included in the Ethernet sampled signal packets.
[0009] In accordance with another aspect of the invention, the processing elements of the system include at least one central processing unit and a plurality of airlink processing units. The central processing unit is responsible for interfacing the system to external environments, such as a macrocellular environment, or to a public switched telephone network, as well as for network management of the overall system. In one embodiment, the central processing unit may be a network chassis unit. The central processing unit is coupled to several airlink processing units through an Ethernet network. Each airlink processing unit is coupled to several radio transceivers, also through the Ethernet network. In one embodiment, the airlink processing units may be airlink chassis units.
[0010] In accordance with another aspect of the invention, the data link layer may be centralized. For the transmission of data to the mobile units, it is important that the data, which is simulcast by several transmitters, be identical. If each simulcast radio frequency transmitter element does not transmit identical signals, co-channel interference can result, thus degrading the signal received by the mobile unit. To ensure that the transmitted data is identical, the layer 2 (data link layer) is centralized at the central processing unit. Layer 2 Ethernet packets are sent by the central processing unit to several airlink processing units, which further process the layer 2 information into waveforms, which are finally transmitted by each simulcast radio transmitter.
[0011] In accordance with another aspect of the invention, transmissions may be implemented by a two-level multicast technique. In an embodiment that utilizes this technique, the transmit data is sent by the central processing unit to multiple airlink processing units in layer 2 format as multicast Ethernet packets. Then, the transmit data is sent by each airlink processing unit to associated multiple radio transceivers in layer 1 format (sample waveforms), also as multicast Ethernet packets.
[0012] In accordance with another aspect of the invention, when signals transmitted from a mobile unit are detected by multiple radio receivers, the system is able to select a desired radio receiver signal for processing. The multiple radio receivers simultaneously provide detected data into the system. The detected data includes identical information, but at different quality levels. The system is able to select a desired signal for processing.
[0013] In accordance with another aspect of the invention, when selecting a received signal for processing, a distributed processing technique is utilized that performs a process of gradual selection. A given mobile device may be located in relatively close proximity to several possible wireless receivers. It is desired to select and process only the signal that is provided by the receiver having the strongest signal from the mobile unit. A selection decision is made by a process that has visibility to all of the relevant receivers in the system.
[0014] In accordance with another aspect of the invention, in a preferred embodiment, the system is interconnected via Ethernet links having limited bandwidth. This configuration would generally make it impractical to forward data from every receiver in the selective decision process because such would tend to rapidly exceed the network capacity. The solution provided by the present invention is to utilize a distributed processing technique that results in gradual selection. More specifically, the selection process may be performed at several different levels, including at the central processing unit and at the airlink processing units. The final selection process is located in the central processing unit, which is at the top of the system hierarchy. However, each airlink processing unit will choose the received signal from only one of the radio transceivers and will forward only one signal to the central processing unit for a final decision. In this way, the simulcast receiver processing is distributed through the system and the selection of the best-received signal is gradually selected as received signals flow up the hierarchy.
[0015] In accordance with another aspect of the invention, the selection process may be more or less distributed, depending on the available data rates of the system. For example, a system utilizing the Global System for Mobile Communications (GSM) technology, which has a relatively high data rate, may allow the central processing unit to have sufficient time to receive signals from several radio processing transceivers in a given airlink processing unit as part of the selection process. An additional technique for screening signals may involve requiring a minimum signal strength, which is detected in the radio transceivers themselves, in order to be forwarded upstream to the corresponding airlink processing unit.
[0016] In accordance with another aspect of the invention, the distributed processing utilized by the selection process may be synchronized. In one embodiment, it is desirable that the signals received from each radio transceiver correspond to substantially the same moment in time in order to correctly evaluate the differences between the received signals. It is desirable that the central processing unit be synchronized with the airlink processing units and the radio transceivers so that the central processing unit knows when to expect the arrival of received signals from the airlink processing units and when a decision in the selection process should be made. It is preferable that the synchronization be performed at least at the end points of the system, i.e., the central processing unit and the radio transceivers. However, the system delay can be further minimized if the processes in the airlink processing units are also synchronized.
[0017] In accordance with another aspect of the invention, a selection time window may be set for making the selection process for the upstream-received data traffic. Thus, selection decision is made by the selection process in the central processing unit within a certain time window, regardless of whether all expected received signal data has arrived at the central processing unit. In general, as part of this method, the central processing unit has a time base that is synchronized with the airlink processing units and the radio transceivers.
[0018] In accordance with another aspect of the invention, the data traffic may be bundled. Inbound traffic received from the radio transceivers is bundled in order to not overwhelm the central processing unit, which services the task for transmitting Ethernet packets. For multiple radio frequency channels, multiple Ethernet packets, each containing a selected received signal, can be periodically sent from each airlink processing unit to the central processing unit. Rather than sending individual Ethernet packets for each radio frequency channel, the data is bundled into one or more Ethernet packets, thus reducing the overhead required to service the transmission of multiple Ethernet packets. Outbound traffic that is transmitted by the radio transceivers may also be bundled, such that information from multiple radio frequency channels is grouped into a single Ethernet packet.
[0019] In accordance with another aspect of the invention, the system may perform selective management of Ethernet switches. In certain areas of the system, the data transmission traffic may be very high, such as at the Ethernet link between the radio transceivers and the airlink processing units, since much of this traffic represents the raw samples of the waveforms. Many of these Ethernet packets are also multicast packets, which would ordinarily be flooded throughout the network. However, in some embodiments this may be undesirable because other network connections in the system, such as between the central processing unit and the airlink processing units, may be burdened or overwhelmed by the traffic. In large systems, it is desirable to configure the Ethernet switches to filter, or reject, the transmission of designated packets on designated ports.
[0020] It will be appreciated that the disclosed system and method are advantageous in that they can be used to provide large geographical coverage (e.g., in an indoor system) with relatively few frequency channels and with relatively low power transmission requirements, and that they thus minimize the interference with the existing macrocellular environment even while operating in the same frequency band for a given cellular standard.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0022] [0022]FIG. 1 is a block diagram of a system architecture;
[0023] [0023]FIG. 2 is a diagram illustrating the flow of data through a non-simulcast system;
[0024] [0024]FIG. 3 is a block diagram of a pseudo-simulcast system;
[0025] [0025]FIG. 4 is a diagram showing a reuse pattern for a one-cell, three-sector system;
[0026] [0026]FIG. 5 is a block diagram of a simulcast system in which the layer 2 processing is performed on the network chassis unit and the layer 1 processing is performed on the airlink chassis unit;
[0027] [0027]FIG. 6 is a diagram illustrating the flow of data through the system of FIG. 5;
[0028] [0028]FIG. 7 is a block diagram of a simulcast system in which the layer 2 processing is performed on the network chassis unit and the layer 1 processing is split between the network chassis unit and the airlink chassis unit;
[0029] [0029]FIG. 8 is a diagram illustrating the flow of data through the system of FIG. 7;
[0030] [0030]FIG. 9 is a block diagram of a simulcast system in which both the layer 2 and layer 1 processing are performed on the network chassis unit;
[0031] [0031]FIG. 10 is a diagram illustrating initialization messages for various scenarios;
[0032] [0032]FIG. 11 is a diagram illustrating a sequence of events that occur as part of a procedure that is executed for each radio blade insertion;
[0033] [0033]FIG. 12 is a diagram illustrating a channel setup ring buffer;
[0034] [0034]FIG. 13 is a flow diagram of a message router task;
[0035] [0035]FIG. 14 is a flow diagram of an outbound message processing task; and
[0036] [0036]FIG. 15 is a flow diagram of an inbound message processing task.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0037] [0037]FIG. 1 shows a system architecture. A network chassis unit NCU serves as a central processing unit and is coupled through Ethernet links to airlink chassis units ACU-X, ACU-Y, and ACU-Z. The network chassis unit NCU is responsible for interfacing the system to external environments, such as a macrocellular system or the PSTN, as well as network management of the overall system.
[0038] The network chassis unit NCU contains network processing cards NPC-A, NPC-B, and NPC-C. The network processing cards NPC-A, NPC-B, and NPC-C may actually be airlink processing cards, as will be described in more detail below. The network chassis unit NCU also includes an Ethernet switch ES which is coupled to a microprocessor PROC. In one embodiment, the Ethernet switch ES may be a broadcom Ethernet switch and the microprocessor PROC may be an 8240 microprocessor. The Ethernet switch ES is coupled through an Ethernet link to an integrated site controller ISC. While an integrated site controller is shown, it will be understood that other types of switching controllers may be substituted. In one embodiment, the communications between the Ethernet switch ES and the integrated site controller ISC are L3 messages/VSELP packets on 15 mSec timing. The integrated site controller ISC includes an access control gateway ACG, which includes processing for sectors A, B, and C, as will be described in more detail below.
[0039] Each of the airlink chassis units ACU-X, ACU-Y, and ACU-Z includes a set of airlink processing cards APC-A, APC-B, and APC-C. The airlink chassis units also each include an Ethernet switch ES, which is coupled to a microprocessor PROC and to each of the airlink processing cards APC, which each also include a microprocessor PROC. In one embodiment, in the configuration of FIG. 1 as well as in other configurations described below, the microprocessors PROC of the chassis units ACU or NCU may be 8240 microprocessors, while the microprocessors of the processing cards APC or NPC may be 8260 microprocessors.
[0040] The communications between the airlink processing cards APC and the Ethernet switch ES include L2 PDUs/IQ packets. The Ethernet switches ES are coupled through Ethernet links to the Ethernet switch ES of the network chassis unit NCU. The Ethernet switches ES of the airlink chassis units ACU are further coupled through Ethernet links to a series of radio units RFU-A, RFU-B, and RFU-C. The communications between the Ethernet switch ES and the radio units RFU are IQ packets (7.5 mSec). Each of the radio units RFU includes radio blades RB (not shown) for transmitting signals.
[0041] As will be described in more detail below, the basic requirement of the simulcast method of the present invention is that the same data is transmitted from every radio blade RB simultaneously for each of the sectors A, B, and C. To achieve this requirement, it is desirable to have all of the radio blades RB within the radio units RFU synchronized together and the protocol data unit PDU for a particular slot sent to all radio blades RB (in the same sector) within the same slot period.
[0042] To guarantee identical protocol data unit PDU data, the associated control procedure ACP, random-access procedure RAP, and voice channel procedure VCP tasks are placed in the network chassis unit NCU rather than the airlink chassis units ACU. This is illustrated in FIG. 1 for the network processing cards NPC-A to NPC-C and, thus, provides a common creation point for the protocol data unit PDU data that needs to be sent to all airlink processing cards APC. By using a multicast address on the outgoing protocol data unit PDU packets and guaranteeing slot synchronization between airlink processing cards APC, a simultaneous distribution of identical data can be made to take place.
[0043] The system and method of the present invention is also described in provisional U.S. Patent Application Serial No. 60/359,638, from which this application claims priority, and which is hereby incorporated herein by reference in its entirety. A related system is described in provisional U.S. Patent Application Serial No. 60/359,637, which is commonly assigned and which is hereby incorporated herein by reference in its entirety, and in an application entitled “RADIO SYSTEM HAVING DISTRIBUTED REAL TIME PROCESSING”, Attorney Docket No. RFNI-1-18802, which is commonly assigned and co-filed with this application, and which is hereby incorporated herein by reference in its entirety.
[0044] [0044]FIG. 2 is a diagram illustrating the flow of data through a non-simulcast system. This system is shown for purposes of illustration and to provide a better explanation of the simulcasting method of the present invention. The non-simulcast method illustrated by FIG. 2 is in an airlink processing card APC (as shown in FIG. 1) based embodiment. In general, the digital signal processors and the tasks that process the protocol data unit PDU data from the digital signal processors are tightly coupled via the host-port interface HPI. As shown in FIG. 2, the tasks that process the protocol data unit PDU data are the associated control procedure ACP, the random-access procedure RAP, and the voice channel procedure VCP. Data is transferred to the associated control procedure ACP and the random-access procedure RAP from a message router MR through message queues MQ. Data is transferred to the voice channel procedure VCP through a function FUNC. Data reaches the message router MR through a queue Q from a digital signal processor reader task RT, and a digital signal processor writer task WT. Data reaches the reader task RT and the writer task WT from the host-port interface HPI. Data reaches the host-port interface HPI from the digital signal processor and, more specifically, from the component DSP-Tx and the component DSP-Rx. Data reaches the component DSP-Tx and component DSP-Rx from the component FPGA, which provides and receives raw I/Q to the radio blade.
[0045] Referring to FIG. 2, the data transfer is started based on what is called a slot request. A slot request is a request by the digital signal processor for a new protocol data unit PDU to transmit in the next slot. In one embodiment, a slot request is received by the digital signal processor reader task RT every 15 mSec, from the DSP component 22 . This slot request event is triggered by the arrival of an I/Q sample packet from the radio blade RB. The digital signal processor reader task RT then sends a message to the message router MR, which calls the appropriate function to get the protocol data unit PDU. The protocol data units PDU are retrieved via function calls and sent via the message queues. The message router MR then sends the protocol data unit PDU to the digital signal processor writer task WT, which then writes it to the digital signal processor. In one embodiment, the time between slot requests is 15 mSec and, as such, there is an approximately 14 mSec period to receive the slot request message and respond back to the digital signal processor with a protocol data unit PDU. The digital signal processor converts the protocol data unit PDU to an I/Q sample packet and then sends it to the radio blade RB for RF transmission.
[0046] In addition to the slot requests, there are also outbound protocol data units PDU from the digital signal processor to the integrated site controller ISC, Handover Messages, inbound integrated site controller ISC messages, periodic monitoring events, and UDP configuration messages that are generally desired to be processed within this 14 mSec period. Many of these additional events are asynchronous and, as such, they can occur at any time and in any grouping. In the system of FIG. 2, there is also generally an Ethernet switch (not shown) that provides proper routing of the Ethernet packets.
[0047] In one embodiment of the present invention, one of the design goals is to have a limit of three control channel frequencies per system, which may make C/I difficult to control via standard cellular reuse techniques. This becomes an issue any time a given radio blade RB is transmitting symbols that do not match those transmitted from other cells. This is a possibility if specific symbols for bearer traffic and control channel messages are not centrally coordinated throughout the service area of the system. These issues will be discussed below with reference to FIG. 3, which illustrates a pseudo-simulcast system, and with reference to FIGS. 5 - 9 , which illustrate true simulcast systems in accordance with the present invention.
[0048] [0048]FIG. 3 shows a pseudo-simulcast system in which layer 2 messages are generated in the airlink chassis units ACU as shown. FIG. 3 has similar components to those of FIG. 1. As illustrated in FIG. 3, for the airlink chassis units ACU, the transmissions from the airlink processing cards APC to the Ethernet switches ES include L3 messages/VSELP packets/IQ packets. The transmissions within the airlink processing cards APC include L2 messages/VSELP packets, which are sent from the microprocessor PROC L2 component, which controls the random-access procedure RAP, associated control procedure ACP, and the voice control procedure VCP, to the component for the SPAM L2 (FEC, MAC), L1. The transmissions from the Ethernet switch ES of the network chassis unit NCU and the Ethernet switches ES of the airlink chassis units ACU include L3-messages/VSELP-packets (15 ms), which are the same type of messages transmitted between the Ethernet switch ES of the network chassis unit NCU and the integrated site controller ISC.
[0049] The distributed layer 2 processing of FIG. 3 simplifies network design, but opens up the possibility of different packaging of layer 2 symbols into airlink frames. In this scenario, every radio unit RFU that transmits a symbol different from the radio unit RFU serving the mobile will effectively be creating random co-channel interference to that mobile. In true simulcast systems, the layer 2 messages are centrally located and distributed to each airlink chassis unit ACU (and then to each radio unit RFU) in a synchronous manner such that each airlink frame from each radio unit RFU contains exactly the same symbols. This could also be accomplished with distributed layer 2 symbol generation and packing but would require a substantial synchronization protocol to assure system-wide symbol-to-airlink packet synchronization.
[0050] [0050]FIG. 4 shows a 1-cell/3-sector reuse pattern. The pattern shows elements for sectors A, B and C. FIG. 4 illustrates an example of how signals transmitted from different radio units RFU in a Sector A sum up in the Mobile Station located in the middle of Sector A. According to one experimental set of results, a simple edge of the cell case (without the increased degradation of channel fading and without including through floor and ceiling effects) showed that pseudo-simulcast systems may, in some circumstances, only have 9.5 dB C/I relative to co-channel non-synchronous control channel symbols. This is generally below the operational threshold for Integrated Dispatch Enhanced Network (iDEN) waveforms and assumes a well-planned and regular network topology, which may be unavailable in certain embodiments. This data point encourages the use of true simulcast control channel (and bearer traffic) messaging over pseudo-simulcast messaging.
[0051] The problems associated with simulcast messaging include nulls created by vector signal cancellation and the need for system-wide synchronization of both symbols (discussed above) and RF frame timing. Simulcast signals will destructively interfere, which will create nulls within the system coverage area. The conditions for deep nulls or near-complete signal cancellation are quite specific, though. In the case of two simulcast signals transmitted with line-of-sight propagation models, the only place where signals will cancel is at the midpoint where each path loss is equal and then only when the RF envelope phases are diametrically opposed. As randomness in terms of channel variability and number of simulcast carriers is increased, it becomes more difficult to create a deep null cancellation. System simulations using simple distance-based path loss modeling and uniform random carrier phase distributions show less than 1% of the total coverage area at risk of deep coverage nulls with two simulcast pilots and less than 0.1% coverage null probability with three simulcast carriers. These simple estimates show that signal nulling is generally not a major concern from a coverage reliability standpoint. It is also important to note that in the 850 MHz band the signal wavelength is short enough that the specific phase cancellation that creates a deep null can be changed by moving the mobile receiver a mere 10 cm. Thus, it is unlikely that a mobile receiver will stay in a deep null for very long.
[0052] From the system-timing standpoint, simulcast forward link packets will appear as multipath elements to the mobile receiver. If the total time delay between the first and last received simulcast signal exceeds the delay spread tolerance of the system signal, degradation will occur. A simple estimate for system delay spread tolerance would be to limit all signals within 10 dB of the main signal path to 10% of the transmit symbol duration. For the iDEN waveform, this translates to capturing all signals within 10 dB of the main signal within 25 μSec. Since true simulcast pilots will often be received as strong or possibly stronger than the signal of interest (an unlikely scenario for normal multipath systems), a conservative estimate would limit total excess time delay between first and last significant signal to 15 μSec. Allocating 5 μSec to time-of-flight variations still allows for 1 mile of excess time of flight between the serving radio unit and all other significant radio units. Even in a line-of-sight network, the radio units located a mile from the serving radio unit would not have enough energy to result in signal degradation. Thus, in this embodiment, 5 μSec appears to be a conservative excess time of flight allowance. This still leaves 10 μSec of “delay spread” budget for base-to-base frame timing variations.
[0053] FIGS. 5 - 9 illustrate different embodiments of simulcast systems in accordance with the present invention. In the embodiment of FIGS. 5 - 6 , the layer 2 processing (L2) is performed on the network chassis unit NCU and the layer 1 processing (L1) is performed on the airlink chassis unit ACU. In the embodiment of FIGS. 7 - 8 , all the outbound processing and L2 are performed on the network chassis unit NCU and inbound L1 are performed on the airlink chassis unit ACU. In the embodiment of FIG. 9, all the processing is done on the network chassis unit NCU.
[0054] To implement the simulcast system of the present invention, the generation of protocol data units PDU can be done at a single central location and, by using a multicast address, can distribute the protocol data unit to all airlink processing cards APC simultaneously. One solution is to have the associated control procedure ACP, random-access procedure RAP, and voice channel procedure VCP tasks operating on an airlink processing card APC in the network chassis unit NCU, thus becoming a network processing card NPC. There will be one network processing card NPC for each sector. Although there is no separate task for a voice channel procedure VCP, the voice channel procedure VCP processing is done as part of the slot request, which still needs to be centralized.
[0055] In the embodiment of FIG. 5, all of the upper L2 processing (CPU, random-access procedure, associated control procedure, voice channel procedure) is located on the network chassis unit NCU in one or more network processing cards NPC. L1 and lower L2 (FEC, MAC) processing is located on the airlink chassis unit ACU in one or more airlink processing cards APC. Outbound protocol data units PDU are simulcast from network processing cards NPC to all the airlink chassis unit(s) ACU, where IQ-packets are generated and simulcast to all the radio units RFU connected to the airlink chassis unit(s) ACU. In the inbound direction, every airlink chassis unit ACU receives IQ-packets from radio unit(s) RFU and selects the best packet for processing. If a valid message is decoded, it is forwarded to network chassis unit NCU where the final selection between packets received from several airlink chassis units ACU is made.
[0056] One of the advantages of the embodiment of FIG. 5 is that, because of short and less frequent L2 protocol data units, there is little traffic between network chassis unit NCU and airlink chassis unit ACU. In addition, the centralized L2, which uses time stamps (slot numbers) in inbound and outbound messages, guarantees synchronization between airlink chassis units ACU. Furthermore, all the detected inbound L2 protocol data units are forwarded to the network processing card NPC, which means that no mobility management is needed to locate the Mobile Station in the system. Finally, with regard to converting a non-simulcast system, no changes are needed to the CPU and digital signal processor processing modules, and only minor changes are needed to the interfaces between digital signal processor and CPU. In addition, the reliability of the system may be further improved by improving the reliability of the link between network chassis unit NCU and the airlink chassis unit(s) ACU to guarantee that critical information maintained by the network chassis unit NCU (like channel setup tables) can be reliably transmitted to every airlink chassis unit ACU.
[0057] [0057]FIG. 6 is a diagram illustrating the functional tasks for the embodiment of FIG. 5, and is somewhat similar to FIG. 2. In this embodiment, the message queue MQ interface between the digital signal processor Reader/Writer task and the message router MR is replaced with the network interface, which includes the local area network LAN accessed from either side by the components TNETTASK. In one embodiment of this method, slot requests are generated by a 15 mSec clock interrupt on the network processing card NPC and sent to the message router MR directly. The generated protocol data unit PDU is then sent to all the airlink processing cards APC for a particular sector via the network, using a multicast address. Inbound protocol data units PDU are also received via the network.
[0058] The embodiment of FIGS. 5 and 6 localizes heavy IQ-packet traffic to the link between the airlink chassis unit ACU and the radio units RFU, and keeps L2 interfaces symmetrical and simple. Even if the CPU and digital signal processor(s) are separated to network chassis unit NCU and airlink chassis unit ACU, the messaging delays are generally acceptable. Collecting protocol data units PDU to/from several radio blades RB together and sending them all at once in one message can reduce the number of messages considerably. In one embodiment, there is a 15 mSec time slot allocated for the messaging delays between CPU and digital signal processor, which is generally sufficient. The reliability of the system is improved by improving the reliability of the link between network chassis unit NCU and airlink chassis units ACU. The architecture has less traffic than certain other embodiments, which makes it possible to develop reliable protocols between the network chassis unit NCU and airlink chassis unit ACU.
[0059] In the embodiment of FIG. 7, all of the outbound L2 and L1 processing is located on the network chassis unit NCU in one or more network processing cards NPC. Outbound IQ-packets are simulcast from network processing cards NPC to all the radio units RFU. Inbound upper L2 (CPU) is located on the network chassis unit NCU in one or more network processing cards NPC. Lower L2 and L1 processing (digital signal processor) is located on the airlink chassis unit ACU in one or more airlink processing cards APC. In the inbound direction, every airlink chassis unit ACU receives IQ-packets from radio units RFU and selects the best packet for processing. If a valid message is decoded it is forwarded to the network chassis unit NCU where the final selection between packets received from several airlink chassis units ACU is made.
[0060] One of the advantages of the embodiment of FIG. 7 is that the centralized outbound L2/L1 processing guarantees synchronization between the radio blades RB. In addition, centralized inbound upper L2 processing means that no mobility management is needed to locate the Mobile Station in the system. Furthermore, if a system clock is available on the network chassis unit NCU, it can process outbound slots in advance and system delays can be made smaller (less buffering is needed to compensate for variations in inbound delays). In addition, the reliability of the system may be further improved by adding a reliable link between network chassis unit NCU and airlink chassis unit(s) ACU to guarantee that critical information maintained by the network chassis unit NCU (like channel setup tables) can be reliably transmitted to every airlink chassis unit ACU (needed in inbound lower L2 and L1 processing).
[0061] One reason that the embodiment of FIG. 5 is sometimes more desirable than the embodiment of FIG. 7 is that, in the embodiment of FIG. 5, in the outbound direction there is less traffic from the network chassis unit NCU to airlink chassis unit(s) ACU. In addition, because inbound and outbound processing are not symmetrical in the embodiment of FIG. 7, further modifications to the interfaces between the digital signal processor and CPU may be needed for certain embodiments.
[0062] [0062]FIG. 8 is a diagram similar to FIGS. 2 and 6 and illustrating the functional tasks for the embodiment of FIG. 7. In accordance with this method, raw I/Q sample packets are simulcast to all radio blades RB directly from the network processing card NPC and do not need to go through the extra network tasks. Inbound message processing is similar to that of FIG. 6. The basic premise for the method of FIG. 8 is that, by eliminating the need to transfer the data to another board through the network, this will reduce the delay time for transmission of outbound protocol data units PDU. Also, since the outbound data is simulcast, the overall network traffic will be acceptable.
[0063] The embodiment of FIGS. 7 and 8 is particularly advantageous in a system where delays can be minimized. To improve the architecture, the network chassis unit NCU/network processing card NPC can be provided with access to a system clock and a copy of slot and frame counters, such that slot requests from airlink chassis unit ACU to network chassis unit NCU are generally not needed.
[0064] In the embodiment of FIG. 9, all of the L2 and L1 processing is located on the network chassis unit NCU in one or more network processing cards NPC. Outbound IQ-packets are simulcasted from network processing cards NPC to all of the radio blades RB and inbound IQ-packets are transmitted from every radio blade RB back to the network processing cards NPC, where the digital signal processors make the final selection between the packets.
[0065] One of the advantages of the embodiment of FIG. 9 is that the centralized L2/L1 processing provides a greater likelihood of synchronization between the radio blades RB. In addition, because all of the IQ-packets are forwarded to the network processing card NPC, no mobility management is required to locate a mobile unit in the system. In comparing the embodiment of FIG. 9 to those of FIGS. 5 - 8 , in the embodiment of FIG. 9 there is a relatively substantial amount of traffic between the network chassis unit NCU and the airlink chassis unit ACU in that every radio blade RB transmits and receives an IQ-packet once every time period, which in one embodiment is every 7.5 mSec. In addition, in the embodiment of FIG. 9, the digital signal processor has to possibly be able to store tens of IQ-packets for the selection process, which may be limiting because of the limited data memory on the digital signal processor. Thus, in some cases, the embodiments of FIGS. 5 - 8 may be preferable over the embodiment of FIG. 9.
[0066] The primary difference between the method of FIGS. 5 and 6 and the method of FIGS. 7 and 8 is that in the method of FIGS. 5 and 6, protocol data units PDU are generated at the network processing card NPC and sent to the airlink processing card APC. The digital signal processors on the airlink processing card APC then convert these protocol data units PDU to raw I/Q samples to send to the radio blades RB. In the method of FIGS. 7 and 8, the digital signal processors on the network processing card NPC convert the protocol data units PDU to raw I/Q samples and are then sent to the radio blades RB directly from the network processing card NPC, thus bypassing the airlink processing card APC.
[0067] Timing is an important aspect of the simulcast method of the present invention. In one embodiment, the voice specification allows approximately 14 mSec to process a slot request and respond with the protocol data unit PDU data for outbound requests. For the inbound protocol data units PDU, one significant requirement is that the data is removed from the digital signal processor before the next protocol data unit PDU arrives 15 mSec later. There are two additional differences of the methods of FIGS. 5 - 8 when compared to a non-simulcast system. One is a need to reduce the overall voice packet delay time, and the other is the packet data requirement.
[0068] It is desirable to reduce the amount of voice delay in the system. For example, in a system where data transfers operate on the 15 mSec (Slot Request) and 15 mSec+7.5 mSec (half-slot) timing reference, a delay decrease of at least 7.5 mSec is of particular value. Two areas are noted in which delay reduction may occur. For the first area of possible delay reduction, in one embodiment, the outbound timing allows for a 14 mSec packet delay between the time when a slot request is made at the digital signal processor and when the data has to be delivered to the digital signal processor. This can be reduced to a 7.5 mSec delay. For the second area of possible delay reduction, in an embodiment where the digital signal processor initially uses 15 mSec for SRC filtering, it may be possible to reduce this time to 7.5 mSec.
[0069] For a simulcast system, a slot request boundary may represent the time at which all outbound packets must have arrived at the network processing card NPC for processing in the next slot. In one embodiment, 7 . 5 mSec is allocated for processing the outbound protocol data units, delivering them to the airlink processing card APC, and writing the protocol data units PDU into the digital signal processor.
[0070] The voice packets that arrive from the integrated site controller ISC are also synchronized to the same slot boundaries and as such will arrive at a fairly consistent time relative to the slot request boundaries. To take advantage of the minimum amount of delay that the outbound voice channel procedure message needs to wait before this slot request, JITA Procedures may be implemented.
[0071] Packet data has additional requirements to that of voice. For voice processing, the outbound data is not dependent upon the inbound data, and can essentially operate as two independent processes. For packet data PRAP messages, the outbound data is dependent upon the inbound data and, as such, it generally does not send its outbound data until it has received and processed the inbound data.
[0072] The inbound timing may be the same for the method of FIGS. 5 and 6 and the method of FIGS. 7 and 8. The inbound timing is more complex because, depending upon the type of message (random-access procedure RAP, associated control procedure ACP, etc.), the digital signal processor processing may take a variable amount of time. Also, the delivery of the data to the airlink processing card APC is dependent upon when the IQ packet arrives at the digital signal processor. Any amount of timing variation on the input results in a timing variation when the data is delivered to the airlink processing card APC.
[0073] To reduce the amount of network messages being sent to the network processing card NPC, the protocol data unit PDU is generally not sent to the network processing card NPC as soon as it arrives at the airlink processing card APC. Instead, it is bundled and sent at particular intervals. Protocol data unit PDU bundling is described in more detail below.
[0074] Because the PRAP messages are generally sent as soon as possible and other messages may not be available for up to 7 mSec later, a protocol data unit PDU bundle may be sent from the airlink processing card APC to the network processing card NPC at every 7.5 mSec interval. Any protocol data units that are available in the first 7.5 mSec (particularly PRAP protocol data units) can be sent at the half-slot boundary and any protocol data units available in the second 7.5 mSec can be sent at the slot boundary.
[0075] Although in some embodiments a delay of up to 40 mSec may occur, this is generally a rare worst case. Almost all messages, with the exception of associated control channel ACC and packet data, will be available in the first half slot. Also, the time to transfer from the airlink processing card APC to network processing card NPC and process may typically be around 1 mSec.
[0076] In one embodiment, there may be up to seven radio blades RB operating at any given time, six dedicated to voice and one dedicated to packet data. Since some tasks require the use of UDP, it is possible that network activity by a process can delay the transmission/reception of critical packets from a critical activity and, as such, needs to be considered as a potential for delay. One problem with estimating the execution time is that a number of events may occur randomly and asynchronously. The slot requests and inbound data occur on every 15 mSec boundary, but many other events may sometimes be considered as random occurrences that can occur at any time and together. For example, during a 15 mSec interval, a voice packet can arrive from the integrated site controller ISC, a voice packet can be sent to the integrated site controller ISC, a dedicated control channel DCC packet can arrive from the integrated site controller ISC, and a handover message can be sent to the integrated site controller ISC.
[0077] To reduce randomness, slot requests can be processed on the start of every 15 mSec-slot request boundary and data transfers from the digital signal processor can be made to occur on every 15 mSec slot and half-slot boundary. Handover messages can also be transferred with every half-slot packet from the digital signal processor. The result is that most random events will be certain asynchronous and pseudo-events. This distribution has the effect of processing the outbound data in one half-slot period and processing inbound data in the second half-slot period with the exception of the occasional associated control channel ACC messages. This method can also be used for the timing specification for packet data.
[0078] To implement the timing for the method of FIGS. 5 and 6, in one embodiment the slot requests will not be generated by the digital signal processor; rather, they will be generated from a 15 mSec clock on the network processing card NPC that is synchronized to the integrated site controller ISC. This means there will be no read from the digital signal processor for slot requests. In one embodiment, it is assumed that to send a packet of data requires 50 μSec and to receive a packet of data requires 120 μSec. To make more efficient use of the messaging, packet bundling is utilized, as will be described in more detail below.
[0079] In summary, in packet bundling, the packets for all radio blades RB will be combined and sent as one to the airlink processing card APC. The result is only one call to a function muxSend (for sending packets) and one call to a Filter Function (for receiving data). This applies to both the network processing card NPC and airlink processing card APC, for both directions. Only messages sent to/from the integrated site controller ISC are sent individually. This means there will only be one network send and receive for all seven radio blades RB and not seven individual send/receives. The network processing card NPC execution times are generally considered to be a limiting factor. Because of the extra time to go through the network, the total execution time to complete inbound and outbound events increases. However, some of this processing is done on the airlink processing card APC and some is done on the network processing card NPC. Since the network processing card NPC has to process the additional asynchronous events, its execution time is important for finishing within the 7.5 mSec window. Handover messages are generally combined with the inbound data.
[0080] For the method of FIGS. 7 and 8, in one embodiment, the I/Q samples are sent to all radio blades RB directly from the network processing card NPC using a multicast address on the Ethernet packets. The inbound processing and delays may generally be similar to those of FIGS. 5 and 6. Two important aspects for the method of FIGS. 7 and 8 are the network processing card NPC execution times and the effect of extra data on the network between the network processing card NPC and the airlink processing card APC.
[0081] To implement the timing for the method of FIGS. 7 and 8, in one embodiment the slot requests will not be generated by the digital signal processor; rather, they will be generated from a 15 mSec clock on the network processing card NPC synchronized to the integrated site controller ISC. This means there will be no read from digital signal processor for slot requests. In one embodiment, it is assumed that to send a packet of data requires 50 μSec and to receive a packet of data requires 120 μSec. Only the inbound data has the extra send/receive. To make more efficient use of the messaging, packet bundling is utilized on the inbound direction, as will be described in more detail below. In one embodiment, inbound processing is distributed between the airlink processing cards APC and the network processing cards NPC. Because of the extra time to go through the network, the total execution time to complete inbound events increases. Since some of this processing is done on the airlink processing cards APC and some is done on the network processing cards NPC, the resulting network processing card NPC margins should only reflect the processing done on the network processing card NPC. Handover messages are generally combined with the inbound data.
[0082] In one embodiment of the methods of FIGS. 5 - 8 , all of the radio blades RB are synchronized with each other to within 10 μSec. All radio blades RB will be provided with a 1 pps timing signal from the integrated site controller ISC. The 1 pps timing signal is also referred to as a 1 pps event. Further, one or more radio blades RB will be provided with a slot and frame number, which will be distributed over the Ethernet to the radio blades RB as an Ethernet SYNC message. All of the radio blades RB which receive an Ethernet SYNC message will set their slot and frame counters to the values provided in the Ethernet SYNC message at the next 1 pps event. This indicates that the 1 pps events, or timing signals, should be distributed to all radio blades RB within 10 μSec of each other. Generation of the Ethernet SYNC message will be done at the network chassis unit NCU either by a component FPGA or by the CPU. The Ethernet SYNC message may then be broadcast to all radio blades RB using a multicast address. Alternatively, all the radio blades RB may be synchronized in a selective manner by sending an Ethernet SYNC message to one or more radio blades immediately before one particular 1 pps event and by later sending another Ethernet SYNC message to one or more other radio blades. The slot and frame numbers contained in any Ethernet SYNC message must correspond to the current running count of slot and frame numbers so that any radio blade may be individually synchronized with the rest of the system.
[0083] In one embodiment, the NCU and each ACU are preferably provided with a time base, which includes a running slot and frame count. Synchronization of the NCU time base will take place according to the following procedures. If the network processing card NPC is not synchronized, it will wait for the reception of a Ethernet SYNC message containing the slot and frame adjust message. The network processing card NPC ISR will respond to a periodic interrupt every 15 mS and read a register on the component FPGA. When the 1 pps bit on the component FPGA becomes set (will only be set for an interrupt, which corresponds to a 1 pps event), the network processing card NPC will start using the slot number from the slot adjust message as the new slot number. The slot number will be incremented at every 15 mS interrupt. Synchronization of the ACU time base takes place using a procedure, which is substantially identical to that used for synchronization of the NCU.
[0084] In the non-simulcast system, the radio blades RB send an inbound I/Q packet with a slot number to the digital signal processor. The digital signal processor then sends this slot number to the airlink processing card APC as part of the slot request. The airlink processing card APC will then respond with a protocol data unit based on the slot number. For the methods of FIGS. 5 - 8 , the amount of time delay introduced by sending a slot request from the airlink processing card APC to the network processing card NPC would generally be greater than a desired time delay. That, combined with the network delays, would result in a considerably varying slot request message at the network chassis unit NCU. The solution is that the slot request will be generated by the synchronized 15 mSec clock on the network chassis unit NCU and not by the digital signal processor. The remaining issue is that the network processing card NPC needs to know which slot to process as part of the slot request. The method by which the network processing card NPC becomes synchronized with the proper slot number is to have the network processing card NPC send a PWM signal from the component FPGA on the LAN interface card LC to a component FPGA on the network processing card NPC. This PWM signal will contain the 15 mSec (possibly 7.5 mSec) clock information and the 1 pps information.
[0085] One problem with one embodiment of the non-simulcast system is that, when a channel setup comes in from the integrated site controller ISC, the Tx and Rx digital signal processor cores get updated with this new channel setup table simultaneously. Outbound slot processing is delayed from the inbound slot processing by a couple of slots. This means the outbound slot processing has a table that is not yet up to date. For voice, this is generally not a problem because there is enough of a delay between when the channel is set up and actually used. For packet data, this is no longer the case because of the tighter coupling between the inbound and the outbound protocol data units PDU. One solution would be to have the digital signal processor store a history of channel tables but, due to space limitations, this may not be an option. Another solution is to send a new channel table with every set of slot request protocol data units. This has several benefits; one is that it keeps the channel table synchronized and up to date with the slot requests. The second is that it eliminates a network send call during the channel setup request on the network processing card NPC, thus reducing the costly channel setup time.
[0086] As noted above, the methods of FIGS. 5 - 8 utilize a bundling technique so as to make more efficient use of the network. Thus, in one embodiment, the protocol data units PDU for each of the radio blades RB are generally combined and sent together as one Ethernet packet. The result is only one muxSend for sending the data and only one call to the Filter Function for receiving data. This bundling is done per radio unit RFU, which is processed by a single airlink processing card APC. Protocol data unit PDU bundling can be employed for sending data from the network processing card NPC to the airlink processing card APC for outbound slot requests and from the airlink processing card APC to the network processing card NPC for inbound data indications. The protocol data unit bundling is handled by the message router MR on the network processing card NPC and the digital signal processor Reader task on the airlink processing card APC.
[0087] The methods of FIGS. 5 - 8 rely on the network interface for protocol data unit PDU exchange, as well as for sending either protocol data units PDU or Raw I/Q samples. In one embodiment, all network activity on an airlink processing card APC goes through a Motorola FCC Ethernet Driver and is scheduled through the tNetTask. For each packet received and transmitted, a “job” is scheduled in the tNetTask. When the time comes for that job to be executed, the data is then sent to the driver for transmission or reception. All sent data to/from the airlink processing card APC will be made from a call to muxSend. Since the entire network stack operates under the same tNetTask, any TCP/IP activity will also need to be scheduled with this protocol data unit PDU activity and, as a result, the protocol data unit PDU packet transmission/reception may become delayed longer than expected because it needs to wait for the TCP/IP packet processing. In one embodiment, for all synchronous and asynchronous activity, the maximum potential delay for a single conflict would be 120 μSec on a packet reception and 170 μSec for an ICMR activity from the pseudocritical task. The network processing card NPC margins are large enough to accommodate these delays.
[0088] Because the protocol data unit PDU transmission takes place over a distributed network, one consideration is to provide a reliable link. To generate a reliable link, packet loss or link failure is detected and retransmission on a packet failure is provided.
[0089] The switch configuration for the systems of FIGS. 5 - 8 is set up such that the 0x1180 packets from the radio blades RB are not transmitted on the interface between the airlink chassis unit and the network chassis unit. In the outbound direction, all protocol data unit PDU bundled Ethernet packets have a multicast address associated with them. In the inbound direction, all protocol data unit bundled Ethernet packets have a unicast address associated with them.
[0090] A message format and type are provided for the airlink processing cards APC and network processing cards NPC that represent the accumulation of multiple protocol data units PDU (Bundle) destined for each airlink processing card APC. The code for the airlink processing card APC and network processing card NPC is implemented such that the same messages arrive at the appropriate message queues. The source of the message sent to the message queue is different from a non-simulcast system, as the Ethernet routines use a multicast address instead of a unicast address. The message router MR task accumulates the protocol data units from each sector. Once every protocol data unit PDU is received, a single protocol data unit PDU is selected based on the RSSI metrics. It is this protocol data unit PDU that is sent on to the appropriate task.
[0091] The digital signal processors perform the inbound message filtering. To do this, the digital signal processors are informed of the addition or removal of a radio blade RB that they will need to process. This generally requires a flag or bit field in a message that is periodically sent to the digital signal processor.
[0092] In contrast to the non-simulcast system, for the methods of FIGS. 5 - 8 , the digital signal processors do not generate the slot requests at the 15 mSec slot request boundary. However, by providing this interrupt, the system can keep a check on what slot number the digital signal processor is processing and what slot number the system thinks it should be processing, thus alerting of an error under these conditions.
[0093] The digital signal processor also sends an RSSI metric set with every inbound message. This is a desired criterion for inbound message selection at the network chassis unit NCU. To simplify the interface, the digital signal processor sends an inbound message with RSSI metric at every slot interval, but only sets the valid sync flag for valid protocol data units. This allows the interface to always be sending the exact type of information each time without having to compensate for variable-length messages.
[0094] For the methods of FIGS. 5 - 8 , in general, the network management includes the association of a network processing card NPC with a group of airlink processing cards APC and radio unit RFUs relating to a particular sector. This includes properly assigning multicast addresses to the appropriate sector. The code bases for the airlink processing card APC and network processing card NPC may be identical, but each is able to recognize itself to allow particular tasks to be started. The network management is also responsible for informing the appropriate network processing card NPC and airlink processing card APC of additional radio blades RB.
[0095] For the method of FIGS. 5 - 6 , the code to support the digital signal processor Reader and Writer accumulates the protocol data units PDU from each digital signal processor and then performs a muxSend instead of an msgQSend for transmitting the protocol data units PDU. For receiving, the digital signal processor Writer WT receives a message from the Filter Function, instead of from the message router task MR, as is done in the non-simulcast system. In further comparison to the non-simulcast system, in the method of FIGS. 5 - 6 , the message router task MR sends through a muxSend instead of a msgQSend. The received data continues to arrive via the message queue from the Filter Function. The network management is generally aware of digital signal processors only on the airlink processing card APC and generally not on the network processing card NPC.
[0096] For the method of FIGS. 7 - 8 , the code to support the digital signal processor Reader accumulates protocol data units PDU from each digital signal processor and then performs a muxSend, instead of a msgQSend, for transmitting the protocol data units PDU to the network processing card NPC, as is done in the non-simulcast embodiment. The digital signal processor writer WT is similar in both cases. Also, the digital signal processor loads are set up to support a single inbound and a single outbound processing for each core. This embodiment may require two outbound loads on the network processing card NPC and two inbound loads on the airlink processing card APC, resulting in a different configuration for the airlink processing cards APC versus the network processing card NPCs. The network management is generally aware of outbound digital signal processors on the network processing card NPC and inbound digital signal processors on the airlink processing card APC for setup and configuration.
[0097] For the embodiments of FIGS. 5 - 8 , the packet data operates on an independent network processing card NPC from the voice processing. The network processing card NPC provides a 15 mSec interrupt to the microprocessor PROC that is synchronized to the integrated site controller ISC I pps clock. The network processing card NPC may also support the reading of the slot number that is associated with this slot request.
[0098] For the embodiments of FIGS. 5 - 8 , the inbound packet selection is the method by which the inbound messages from the radio units RFU and airlink chassis units ACU are combined into one message representing that sector to send to the integrated site controller ISC. Multiple airlink chassis units ACU and multiple radio units RFU can be distributed throughout a sector. For multiple radio units RFU, the digital signal processor is responsible for selecting the appropriate inbound packet. The result is a single inbound message from each airlink chassis unit ACU representing a particular sector.
[0099] For multiple airlink chassis units ACU, the network processing card NPC receives an inbound message from each airlink processing card APC representing a particular time slot and sector. This inbound message occurs at every half-slot boundary regardless whether there is an actual message to deliver and is possible at a slot request boundary for the associated control channel ACC type messages. Appended to each inbound message are the channel quality measurement values for that particular slot. This channel quality metric includes RSSI, I+N and sync errors. The sync error flag is used to first compare the time slots, and any message with an invalid sync is ignored. The RSSI and I+N value is then used to compute the SQE for that particular slot from each airlink chassis unit ACU. The airlink chassis unit ACU with the largest SQE has its inbound message selected as the appropriate message to process and send onto the integrated site controller ISC. In addition to selecting the inbound message, the selected channel quality set is also the set used for that particular time slot to form the handover message. In one embodiment, this metric set is sent to the network chassis unit's new base radio management BRM entity where it accumulates 24 sets of measurements and then sends out as a handover measurement report.
[0100] Based on the network processing card NPC execution times, the method of FIGS. 5 - 6 when compared to the method of FIGS. 7 - 8 , in some embodiments provides a more efficient process by offloading the time-consuming digital signal processor writing to another processor. Although, in one embodiment the total cycle time is longer for the method of FIGS. 5 - 6 by 170 μSec, the potential for delays is reduced by not having to compete with the CPU for so many other things. The efficiency of the method of FIGS. 5 - 6 is realized because it is sometimes much faster for the CPM module of the network processing card NPC to send Ethernet protocol data units PDU to the airlink processing card APC than it is for the network processing card NPC CPU to write the protocol data unit PDU data into the components DSP.
[0101] In certain embodiments, both the method of FIGS. 5 - 6 and the method of FIGS. 7 - 8 achieve a desired 15 mSec overall processing delay. The software of the method of FIGS. 7 - 8 is slightly more complex because the separation of inbound and outbound are processed on separate boards. In addition, in certain embodiments, both the method of FIGS. 5 - 6 and the method of FIGS. 7 - 8 gain an additional 160 μSec in delay reduction over the non-simulcast system because the slot requests are generated at the network processing card NPC and not from the digital signal processors.
[0102] The capacity of the methods and systems of FIGS. 5 - 8 can generally be improved by improving the time it takes to process a protocol data unit PDU for each radio blade. Since the number of radio blades RB multiplies this time in terms of the overall processing time of the overall system, any time savings translates into multiplied savings. In addition, the channel setups of the systems update the digital signal processor setup tables when the digital signal processor gets the setup request message. If this channel setup information is sent with the slot requests, then it eliminates a network send.
[0103] For the methods of FIGS. 5 - 8 , the messages that are sent between the airlink processing card APC and digital signal processor are service access point SAP messages. Such messages generally work with the iDEN specifications. The protocol data units PDU are combined with additional information to make up the service access point SAP. It is the service access point SAP that is generated by the slot request and written into the digital signal processor.
[0104] To implement the methods of FIGS. 5 - 8 , a message is used specifically to represent the service access points SAP sent to the airlink processing cards APC and the service access points SAP sent to the network processing card NPC. The message represents the accumulation of service access points SAP for each radio unit RFU on a particular airlink processing card APC. Depending upon the configuration, in an embodiment with seven radio blades RB, there can be up to seven service access points SAP represented per message, one for each radio blade RB. Each service access point SAP would be associated with a different base radio identification BrId.
[0105] Radio blades RB or radio units RFU can be inserted dynamically into the systems of FIGS. 5 - 8 ; either at system startup or after the system has already been running. Setting up and managing the starting and stopping of radio blades RB is handled by the iRBS and iRBC tasks running on an interface card IC and a LAN interface card LC, respectively. Setting up and managing the base radio session BRS and airlink processing card APC channel setup tables is managed by the base radio session BRS on the LAN interface card LC and the channel setup CS task on the network processing card NPC. Several different startup scenarios may occur, each of which may require a slightly different action on the part of the system. These scenarios are all based on starting multiple radio unit RFUs on multiple airlink chassis units ACU for the same carrier. Four scenarios are discussed in more detail below, the first three of which are illustrated in FIG. 10.
[0106] As illustrated in FIG. 10, for a first scenario, a first radio unit RFU is started in a first airlink chassis unit ACU, which is designated as ACU #1 in FIG. 10. This is the case of the very first radio blade RB, which is designated as RB #1 in FIG. 10. In this case a base radio BR session will need to be started with the integrated site controller ISC, the network processing card NPC channel setup CS will need to be informed of the channel tables, and the airlink processing card APC will need to be setup for the first time with the channel tables. In the embodiment of FIG. 10, all of the radio blades RB are on the same carrier and are assigned to the same base radio BR and the same sector.
[0107] As further illustrated in FIG. 10, for a second scenario, a second radio unit RFU is started on the first airlink chassis unit ACU. In this case, only the airlink processing card APC needs to be informed that another radio blade RB (designated as RB #2 in FIG. 10) is present. The airlink processing card APC will set up the digital signal processor so that it is aware of another radio unit RFU to process. In this embodiment, neither the base radio session BRS nor the network processing card NPC channel setup CS Task generally needs to be made aware of this. In this scenario, the base radio BR has not been unlocked yet.
[0108] As further illustrated in FIG. 10, for a third scenario, the first radio unit RFU on the second airlink chassis unit is started after the base radio BR is unlocked. In this case, the network processing card NPC channel manager CM needs to set up the channel tables on the new airlink processing card APC.
[0109] For a fourth scenario (not shown), the second radio unit RFU is started on an airlink chassis unit ACU that is already operational. In this case, only the digital signal processor needs to be informed that it has another radio blade RB to process. In this case, the digital signal processor needs to make a decision as to which inbound I/Q packet to accept.
[0110] The message from the iRBS task to add an additional radio blade RB can come at any time. In one embodiment, if the base radio session BRS is still locked, then the channel setup CS will generally have to wait until it receives a message UNLOCK trigger from the base radio session BRS before setting up the airlink processing card APC. Once the base radio BR is in the unlocked state, all additional radio blades RB will be handled by the channel setup CS on the network processing card NPC.
[0111] It should be noted that, in the embodiment described above, there could be up to seven radio blades RB per radio unit RFU, but each radio blade RB in a radio unit RFU is associated with a different base radio session BRS. While FIG. 10 is illustrated for a single base radio session BRS, it will be understood that all others will follow the same sequence independently. The additional radio unit RFU on a single airlink chassis unit ACU in FIG. 10 represents the addition of the next radio blade RB that is associated with an already initialized base radio BR. In this implementation, it is assumed that, as long as at least one radio blade RB is operational, the base radio BR will be considered operational. It should also be noted that, in this embodiment, the radio blade RB synchronization does not generally take place until airlink chassis unit ACU and network chassis unit NCU synchronization has taken place.
[0112] One difference between the model of FIG. 10 and the non-simulcast system is the addition of the radio blade RB Add messages from the iRBS task. The channel setup CS task determines if it is the first radio unit RFU. If it is, then it sets up the channel tables on the new airlink processing card APC. If it is the second radio unit RFU on the first airlink processing card APC, then it informs the digital signal processor of the additional radio blade RB to process. The GPS Slot/Sync procedure is also different, as will be discussed in more detail below.
[0113] Upon power-up, the network processing card NPC determines that it is a network processing card NPC by reading a hardware register. In one embodiment, once the network processing card NPC has determined that it is a network processing card NPC, all tasks except the Dsp Reader RT (RFN_DSPR_TASK), Dsp Writer WT (RFN_DSPW_TASK), and message router MR (RFN_DSPX_TASK) tasks are started.
[0114] Upon power-up, the airlink processing card APC determines that it is an airlink processing card APC by reading a hardware register. Once it has determined that it is an airlink processing card APC, all tasks except the random-access procedure RAP, associated control procedure ACP, inbound message task INTASK, outbound message task OUTTASK, message router MR, and all packet data related tasks will be started.
[0115] In addition to the normal startup sequence, in one embodiment, the interface card IC also makes sure the airlink chassis unit ACU is synchronized with the network chassis unit NCU before allowing the radio blades RB to become initialized. The Timing component FPGA on the interface card IC handshakes with the LAN interface card LC to synchronize itself. In one embodiment, the CPU on the interface card IC periodically checks the status of the Timing component FPGA and, when a sync lock is detected, it proceeds with the radio blade RB initialization. In this embodiment, inbound messages are generally not sent from the airlink chassis unit ACU to the network chassis unit NCU unless synchronization has been achieved.
[0116] In the non-simulcast system, the slot number on the radio blades RB is set by the base radio session BRS. The sequence is started by the base radio session BRS sending a GPS Slot/Frame Request, and waiting for a GPS Slot/Frame response with the slot number. When the integrated site controller ISC sends a GPS slot/frame response message with the current slot number, the base radio session BRS sends an Ethernet message to the radio blade RB to set the slot number. This method is acceptable when there is only one radio blade RB associated with one base radio BR. However, since there are multiple radio blades RB per base radio BR for the simulcast methods of FIGS. 5 - 8 , the radio blade RB management task sends the message to the radio blade RB to set the slot number.
[0117] [0117]FIG. 11 is a diagram illustrating the sequence of events that take place as part of the GPS Slot/Sync procedure that is executed for each radio blade RB insertion. In FIG. 11, all radio blades RB are on the same carrier and assigned to the same base radio BR and same sector. As illustrated in FIG. 11, upon entering the GPS Slot/Sync state, the base radio session BRS sends the GPS Slot/Frame Sync message to the iRBS task. This triggers the iRBS task to send a GPS Slot/Frame Request to the integrated site controller ISC, and the integrated site controller ISC responds with the frame and slot number in the GSP Slot/Frame Response. If this is the first radio blade, then the iRBS task waits for this trigger from the base radio session BRS so that it can maintain the proper state.
[0118] As additional radio blades RB are initialized for a particular base radio BR, the iRBS task requests a slot/frame number from the integrated site controller ISC. This GSP Slot/Frame response is a multicast address and is sent to all base radio BRs in the system. Normally under such circumstances, the Distributor task could route a message to each base radio session BRS, but since the iRBS task is responsible for all radio blades RB, in this embodiment, a single message to this task is utilized and considered to be sufficient. The Slot and Frame number is set in the component FPGA at the following I pps following the Slot Timing Adjust message.
[0119] For the methods of FIGS. 5 - 8 , a channel setup task CST running on the network processing card NPC is responsible for managing the channel tables for all airlink processing cards APC in the system. In the channel setup task CST of the non-simulcast method, the method writes information to the digital signal processor on reception of Logical Channel Assignments, channel setups CS, and base radio BR Unlock triggers. Since, in the simulcast methods of FIGS. 5 - 8 , the digital signal processors are not located on the network processing card NPC, this information needs to be sent to the airlink processing card APC for loading into the airlink processing card APC.
[0120] Referring to FIG. 10, the 0x1106 messaging is expanded to include messaging to/from the airlink processing card APC for setting up this same information. The 0x1106 messaging is used for the Channel Assignments and base radio BR Unlock Triggers, which, in this embodiment, generally occur only once during initialization. Any channel setup CS Requests received from the integrated site controller ISC are generally sent to the airlink processing card APC as part of the slot request bundle to reduce unnecessary net traffic. Upon reception of a channel setup request, the local (network processing card NPC) channel table is updated to reflect the changes.
[0121] Channel setup tasks CST respond to a number of different types of messages. These will generally be 0x1106 messages between network processing card NPC and the system LAN interface card LC and 0x1186 messages between airlink processing cards APC and network processing cards NPC. One of these messages is a trigger to unlock the base radio BR, which is sent from the base radio session BRS to the network processing card NPC. Another message is for sending system parameters to the airlink processing card APC, which is sent from the network processing card NPC to the airlink processing card APC. Another message is for confirmation on setting system parameters, which is sent from the airlink processing card APC to the network processing card NPC. Another message is confirmation on unlock, which is sent from the network processing card NPC to the base radio session BRS.
[0122] An additional message is the confirmation of the logical channel assignment, which is sent from the network processing card NPC to the base radio session BRS. Another message is the trigger to lock the base radio BR on the network processing card NPC, which is sent from the base radio session BRS to the network processing card NPC. Another message is the trigger to lock the base radio BR on the airlink processing card APC, which is sent from the network processing card NPC to the airlink processing card APC. Another message is for signaling the primary control channel setup, which is sent from the network processing card NPC to the airlink processing card APC. Another message is to confirm on the primary control channel setup, which is sent from the airlink processing card APC to the network processing card NPC. Another type of message is to inform of additional radio blades RB being ready, which is sent from the rRBS task to the network processing card NPC, although it should be noted that this is not a 0x1106 message, but a message from the iRBS tasking, indicating to the channel setup task CST that an additional radio blade RB is now ready.
[0123] Referring to FIG. 10, the channel setup task will set up the network processing card NPC channel information from an unlock base radio BR message from the base radio session BRS. If this is an initial airlink processing card APC, it will set up the System Parameters on that particular airlink processing card APC. The Filter Function on the network processing card NPC is responsible for forwarding all 0x1106 and 0x1186 messages to the channel setup CS Task. On the airlink processing card APC, the Filter Function is responsible for forwarding all 0x1186 messages to the message router task.
[0124] The channel setup CS Task is also responsible for providing the proper channel table to be sent to the digital signal processor after processing each slot request. In one embodiment, there generally needs to be a delay between what is sent to the Tx Core versus what is sent to the Rx Core. This is because the Rx core is processing a different slot from the Tx core at any given time. To implement this, a circular channel table buffer is implemented, as illustrated in FIG. 12.
[0125] Referring to FIG. 12, an example is provided in which the numbers in a ring buffer RBUF represent a different slot number. A channel setup CS request would reconfigure the channel table at a particular slot number (e.g., #1). In this example, table #9 would be the previous table that the Rx core is currently using and the #6 would be a delay of N (3 in the example) tables that the Tx core is currently using. By incrementing the buffer pointer at each slot request, the tables for the Rx and Tx core are controlled.
[0126] [0126]FIG. 13 is a flow diagram of the message router task MR. The message router task MR is responsible for interfacing between the network and the digital signal processor Reader and writer task WT on the airlink processing card APC. This task responds primarily to three events. The first event is for a Slot Request Timer, which is an event in which every 7.5 mSec a bundle is sent to the network processing card NPC. The second event is for Trigger Messages, which are 0x1186 base radio BR control messages from the network processing card NPC. The third event is for Outbound Bundles, which are Outbound bundle messages sent to the digital signal processor writer.
[0127] As illustrated in FIG. 13, at a block 310 , the routine initializes the function variables. At decision blocks 312 and 314 , the routine enters a loop including a 7.5 mSec delay interval, which continues until a message is received as determined at decision block 314 . Once a message is received, the routine proceeds to a decision block 320 , where the routine determines whether the received message is an inbound bundle. If the message is an inbound bundle, then the routine proceeds to a decision block 332 .
[0128] At decision block 332 , the routine determines whether the end of the bundle has been reached. If the end of the bundle has been reached, then the routine returns. If the end of the bundle has not been reached, then the routine proceeds to a block 334 . At block 334 , the routine duplicates the Mblk as a single protocol data unit PDU message. At a block 336 , the routine sends the message to the DSP writer, and then returns to decision block 332 .
[0129] If at decision block 320 the received message is not an inbound bundle, then the routine proceeds to a decision block 322 . At decision block 322 the routine determines whether the received message is a trigger message rather than a slot timer event. If the received message is a trigger message, then the routine proceeds to a block 342 . At block 342 , the routine processes the trigger and then returns.
[0130] If at decision block 322 the routine determines that the received message is not a trigger message but is instead a slot timer event, then the routine proceeds to a block 352 . At block 352 , the routine sends the bundle. At a block 354 , the routine sets up a new bundle, and then returns.
[0131] In one embodiment, in order to eliminate an extra copy from the digital signal processor reader task to the message router task MR, an API is available to call from the digital signal processor reader task that returns a pointer to the Mblk location where the data should be written. Thus, this is how one local copy of the outbound bundle is shared between the digital signal processor Reader task and the message router task MR. The digital signal processor writer receives messages containing an Mblk, which contains the protocol data unit to write into the digital signal processor. To reduce the changes required over the original digital signal processor writer version, a function is used to provide a method to copy the data in an Mblk to another Mblk. This routine does not actually copy the data; rather, it increments a reference counter to the original Mblk and the Mblk does not get released until after every reference to the Mblk is released. This allows the multiple messages to be sent to the digital signal processor writer with each message referencing the original Mblk, thus eliminating a copy of the protocol data unit PDU.
[0132] The digital signal processor reader task RT is responsible for reading the inbound messages from the digital signal processor and adding them to the bundle. To eliminate a copy of the protocol data unit from the digital signal processor Reader to the message router via a message queue, in one embodiment, the digital signal processor reader writes directly to an Mblk that is shared between the message router and the digital signal processor Reader. An API is available that allows function calls to be made to lock the buffer and obtain the location to write to.
[0133] The digital signal processor writer task WT receives a single message with an Mblk containing the protocol data unit to write. The digital signal processor writes the protocol data unit PDU to the digital signal processor and frees the Mblk.
[0134] The message router MR task processes outbound slot requests or inbound messages independently. The inbound processing is somewhat complex as a result of the need to select from multiple airlink chassis units ACU. In one embodiment, the message router MR task is separated into two separate tasks called outbound message task OUTTASK and inbound message task INTASK. In one embodiment, the OUTTASK receives a single slot request message every 15 mSec on the slot request boundary. The message comes from the slot request timer. The OUTTASK then checks for each active base radio BR that is set up, and calls the appropriate slot request function, and adds the resulting protocol data unit PDU to the outbound message.
[0135] [0135]FIG. 14 is a flow chart of the outbound message task OUTTASK. The block “Process for Outbound SDB” is similar to what is done in a non-simulcast system. As illustrated in FIG. 14, at a block 410 , the routine initializes the function variables. At decision blocks 412 and 414 , the routine enters a loop as controlled by the slot request timer, to determine when a message is received. When decision block 14 determines that a message has been received, then the routine proceeds to a block 420 .
[0136] At block 420 the routine gets the active base radio I.D. At a block 422 , the routine processes the slot number to slot type information (baseRld). At a block 424 , the routine processes for outbound PDUs. At decision block 426 , the routine determines if the end of the active base radios have been reached. If not, the routine returns to block 420 . If at decision block 426 the end of the active base radios have been reached, then the routine proceeds to a block 428 . At block 428 the routine sends a bundle to the airlink processing card APC, and then returns to decision block 412 .
[0137] In the simulcast system of the present invention, because there can be multiple radio blades RB for a particular channel within listening distance of a mobile device, it is likely that a message sent from the mobile device will be received on multiple radio blades RB. The result is identical messages sent from two sources to the inbound message task INTASK. In one embodiment, these duplicate messages are reduced to a single message before the associated control procedure ACP or random access procedure RAP tasks perform their processing. There are two places the inbound messages need to be selected. One place is the digital signal processor for a particular radio unit RFU, as was previously discussed. The second place is at the inbound message task INTASK for messages from each airlink chassis unit ACU, which is discussed in more detail below.
[0138] Upon reception of an inbound message, the inbound message task INTASK receives an Ethernet message with a bundle of protocol data units. There will be a bundle from each airlink chassis unit ACU in the system. If there is only one airlink chassis unit ACU, then the first bundle received will be processed. If there are multiple airlink chassis units ACU in the system, then the inbound message task INTASK is generally made to wait until all bundles are received. An inbound message timer is used to prevent the system from blocking indefinitely on a missing bundle.
[0139] Once all of the bundles are received, all protocol data units PDU in the bundle that have the same base radio BRID and slot number will be compared. The protocol data units PDU will first be checked to make sure the sync flag is valid and, if it is not, then that protocol data unit PDU is discarded; otherwise, it is used for the comparison. In one embodiment, based on the RSSI and I+N, the SQE for that slot will be computed. The protocol data unit with the largest SQE will be selected for further processing and the remaining protocol data units will be dropped. The RSSI measurement set that came with the selected protocol data unit PDU is forwarded to the appropriate base radio session BRS for handover message generation.
[0140] [0140]FIG. 15 is a flow chart of the inbound message task INTASK. In one embodiment, there is only one timer and it is enabled upon the reception of the first airlink chassis unit ACU message. If the timer event happens, then the currently available bundle is used and any following bundles from the same time slot are discarded. The system also reports an Error. The timer in FIG. 15 generally has a higher resolution than what is offered by the system clock.
[0141] As illustrated in FIG. 15, at a block 510 , the routine initializes the function variables. At decision blocks 512 and 514 , the routine enters a loop with a timer that is enabled at a block 524 (as will be described in more detail below), which continues until a message is received. Once it is determined at decision block 514 that a message has been received, then the routine continues to a decision block 516 . At decision block 516 , the routine determines whether the received message is an inbound message rather than an inbound message timer event. If at decision block 516 the routine determines that the received message is not an inbound message and is thus an inbound timer event, then the routine proceeds to a block 532 . At block 532 , an error is reported, and the routine then proceeds to a block 540 , as will be described in more detail below.
[0142] If at decision block 516 , the routine determines that the received message is an inbound message, then the routine continues to a decision block 522 . At decision block 522 , the routine determines whether the final airlink chassis unit ACU has been reached. If the final airlink chassis unit ACU has not been reached, then the routine proceeds to block 524 , where the timer is enabled, and the routine returns to decision block 512 .
[0143] If at decision block 522 the routine determines that the final ACU has been reached, then routine continues to block 540 . At block 540 , the timer is disabled. At a block 542 , the routine choose an appropriate inbound PDU. At a block 544 , the routine sends the HO measurement report to the base radio session. At a block 546 , the routine processes for inbound SDB. At a decision block 550 , the routine determines whether there are additional PDUs in the list. If there are additional PDUs in the list, then the routine returns to block 542 . If there are not PDUs remaining in the list, then the routine returns to decision block 512 .
[0144] The Network and radio blade RB management tasks are responsible for the association of a particular radio blade RB, radio unit RFU, airlink processing card APC, airlink chassis unit ACU, and base radio session BRS. In the simulcast systems of the present invention, there can be multiple radio unit RFUs and airlink chassis units ACU associated with a particular sector. Upon detection of a radio blade, the iRBS task notifies the appropriate network processing card NPC that an additional radio blade RB has been added. This message identifies the airlink processing card APC and radio unit RFU that is associated with the radio blade RB. The radio blade task RBT is responsible for the GPS slot/frame sync to the radio blades RB, as was described above.
[0145] In the non-simulcast embodiment, the slot requests come as messages to the message router MR with the slot number. In the simulcast embodiment, the same slot request message is sent to the outbound message task OUTTASK, although one difference is that the source of the message is the ISR that is synchronized to the integrated site controller ISC clock. In one embodiment, the Interface Card IC and LAN interface card LC have a component FPGA that is programmed to generate a 15 mSec signal to the airlink processing card APC/network processing card NPC that is synchronized with the 1 pps integrated site controller ISC signal. This is used as a trigger for inbound and outbound processing.
[0146] An inbound message timer is used to trigger the event in which the INTASK is expecting a message from the airlink chassis unit ACU, but never receives it. The problem here is that the inbound message task INTASK needs to know within a reasonable time period (e.g., about 1 mSec) so that it can meet the outbound timing requirements even though, in one embodiment, the system clock is at about a 16 mSec resolution. In one embodiment, the solution is to use an auxiliary clock AUXCLOCK. The auxiliary clock AUXCLOCK is set up with a resolution of 1000 ticks/sec resulting in a 1 mSec interval. An ISR is attached to this system clock so that it will send a Timeout Message after 1 mSec to the inbound message task INTASK. The auxiliary clock AUXCLOCK is enabled only after the first inbound message is received and disabled after the second message or a timeout. This prevents the auxiliary clock AUXCLOCK ISR from going off during periods that it is not needed and wasting valuable CPU cycles. This effectively configures the auxiliary clock AUXCLOCK as a one-shot timer.
[0147] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. | A distributed radio system with multiple transceivers for simulcasting and selective processing of received signals is provided. The distributed radio system includes a plurality of processing elements and radio frequency transmitter elements interconnected by an Ethernet network. The system designates a number of radio frequency transmitter elements to be elements of a radio frequency simulcast set. The system utilizes relatively few frequency channels, and transmits at very low power levels, and thus causes minimal interference with an existing macrocellular environment. When signals transmitted from a mobile unit are detected by multiple radio receivers, the system is able to select a desired radio receiver signal for processing. When selecting a received signal for processing, the system utilizes a distributed processing technique that performs the selection process throughout several levels. The distributed processing utilized by the selection process may be synchronized. A selection time window may be utilized for making the selection process for the upstream-received data traffic. The system utilizes a centralized data link layer. Transmissions are implemented by a two-level multicast technique. The data transmission traffic is bundled. Selective management of the Ethernet switches is performed by the system. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a solid state radiographic imaging device and more particularly to a device having a plurality of sensors with extended active image capturing surface area.
2. Description of Related Art
Advances in solid state electronic component technology have led to the development of image capture panels comprising two dimensional arrays of individual sensors. Such panels have found applications in radiography wherein the panel is exposed to modulated X-ray radiation carrying imaging information. The image information is stored in the individual sensors typically in the form of charges trapped in a capacitor. These charges which represent the image are read out of the array capacitors and following electronic processing, the charges are stored for display as a visible image. When the radiation is X-ray radiation which impinges on the panel after passing through a patient, the end result is a medical radiogram.
U.S. Pat. No. 5,319,206 issued to Lee et al on Jun. 7, 1994 describes a system which employs such a panel to capture a radiogram.
The panels, as stated above, comprise a two dimensional array of sensors with associated switching and addressing circuitry built on an insulating substrate, usually a glass plate. Such sensors typically include a pair of generally coplanar conductive microplates separated by a dielectric layer. Extending over all the sensors above the microplates is a photoconductive layer which is sensitive to X-ray radiation. A top electrode is placed over the photoconductive layer.
The two microplates in each sensor serve to collect and store charges representing the radiation exposure of the sensor. Radiation exposure is the product of the radiation intensity and the time duration of radiation impingement on the sensor.
In operation, a charging voltage is applied to the bottom microplates of all sensors and the top electrode. This creates an electric field in the photoconductive layer. Upon exposure to radiation, electron/hole pairs are generated in the photoconductive layer by the absorbed radiation exposure energy. Under the influence of the applied electric field the electrons and holes produced separate and migrate along the field lines toward the top electrode and toward the microplates. In detector structures where a positive charging voltage is applied to the top electrode, electrons move along the field lines toward the top electrode, and holes migrate toward the top microplates. The hole migration results in a charge accumulation during exposure in the charge storage capacitors formed by the two microplates and the dielectric separating them. Subsequent removal of the charging voltage and the exposing radiation leaves the accumulated charges trapped in the capacitors.
As can be seen by this brief description of the panel operation, the charges are captured in the sensor areas covered by the microplates. These areas are typically confined by orthogonal intersecting columns and rows of interstitial spaces in which run conductive strips which are used to address the individual sensors, to recover the stored charges during readout of the image, and to apply the charging voltage to the bottom microplates.
In order to individually address each sensor, a solid state switch is built in each sensor. One side of the switch is connected to the top microplate. A typical addressing and switching arrangement uses a TFT transistor switch constructed in a cutout portion of the microplates. The technology to produce TFT transistor switches is disclosed in U.S. Pat. Nos. 5,003,356 and 5,032,883.
The area occupied by the TFT transistor, the charging lines, the data strips and the addressing strips are non imaging areas. It is therefore important to minimize them. However very little can be done to minimize the area occupied by the switching element, and there are practical limits as to how close to the data and address strips can the microplates be built without risking shortages.
The prior art has attempted to extend the image capture area by a sensor structure as shown in FIGS. 1 and 2 which are a schematic cross-sectional elevation and a top view of a typical prior art sensor.
As shown in FIG. 2, the sensor includes a substrate 9, which may be a glass plate, a bottom microplate 12 and a top microplate 14. Microplates 12 and 14 are separated by a dielectric layer 13. Each sensor includes a TFT transistor switch 15. The TFT switch has a gate electrode 16 built on the glass substrate 9. The TFT gate electrode is covered by an insulating layer which can be the same as dielectric layer 13. In addition to the gate electrode, it includes a drain electrode 18, a source electrode 20 and a semiconductor material 19. The drain electrode 18, is the electrode which receives the data signal from the capacitor, and is directly connected to a top microplate 14.
As shown in FIG. 1, the source electrode 20 is connected to a data conductive strip 22 extending along one side of the sensor, while the gate electrode 16 is connected to an addressing conductive strip 24 running along a second side of the sensor. A photoconductive layer 30 and a top electrode 32 are coated over the microplates, the TFT switch, and the addressing and switching strips as shown in FIG. 2. Additional insulation layers not illustrated are often used between the photoconductor and any conductive electrodes in the panel to prevent direct contact between the conductors and the photoconductor layer.
The prior art extends the active image capture area of the first top microplate 14, by using a second top microplate 26 to create a composite top microplate structure. The first top microplate 14 is totally covered by the second top microplate 26. The surface area of the second top microplate 26 is larger than the first and the second top microplate rises above and extends like a mushroom or tent over the TFT switch. As shown in FIG. 2 the second top microplate also extends to cover a portion of the spaces between sensors.
This solution, albeit effective in increasing the active area of the sensor, has the unwanted side effect of shielding the top microplate 14. Because in erasing the sensor following image readout, the array is illuminated with uniform visible radiation which renders the photoconductive layer conductive and results in the redistribution of the charges, it is important that as much light as possible reaches the photoconductive layer in as uniform a manner as possible. Passing through two layers of deposited metal, no matter however transparent, results in some illumination loss. It is therefore desirable to provide a top microplate structure which, while maintaining the efficiency of the dual microplate extended active surface area for charge capture, does this without loss in visible light transmission during the erase cycle.
SUMMARY OF THE INVENTION
The present invention comprises an image capture panel including a substrate layer of dielectric material having a top surface and a bottom surface. A plurality of radiation detection sensors is arrayed in rows and columns on the substrate separated by interstitial spaces, each sensor comprising a charge collecting capacitor formed of a bottom conductive microplate and a generally parallel thereto top conductive microplate separated by a dielectric layer, and a switching element in a space adjacent to the capacitor.
Each sensor further includes a charge collector electrode located at a level higher than the top microplate and the switching element, overlapping the switching element and terminating opposite the top microplate edge, or partially extending over the top microplate along an edge thereof and also partially extending over the interstitial spaces separating the sensors, said charge collecting electrode being electrically connected to said top microplate.
The sensors in the panel are overcoated with a photoconductive layer which is placed over the top microplate and the charge collector electrode, and a top conductive electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top view of a portion of an image panel according to the prior art.
FIG. 2 is a schematic cross-sectional view of the prior art image capture panel of FIG. 1 along arrows 2--2.
FIG. 3 is a top view of a portion of a radiation detection panel of the type discussed herein.
FIG. 4 is a schematic top view of an image sensor of the type used in the image panel shown in FIG. 3, according to the present invention.
FIG. 5 is a schematic cross-sectional view of the image sensor taken along arrows 5--5 in FIG. 4, according to the present invention.
FIG. 6 is a schematic top view of an alternate image capture sensor according to the present invention.
FIG. 7 is a schematic cross-sectional view of the alternate image capture sensor of FIG. 6 taken along arrows 7--7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention will next be described in detail with reference to the figures which are used herein by way of illustration rather than limitation. Similar numbers are used in all figures to designate parts common in such figures.
FIGS. 1 and 2 which illustrate a typical panel and sensors such as disclosed in U.S. Pat. No. 5,498,880, have been described in the section entitled "Description of related art" above, and are fully described in the issued U.S. Pat. No. 5,498,880 the disclosure of which is incorporated herein and made a part hereof.
Referring next to FIG. 3 there is shown a top view of a portion of a panel constructed according to the present invention showing an array of nine sensors 111 arrayed in three rows and three columns. The sensors 111 each include a switching element 115 and are separated from each other by interstitial spaces 127. A plurality of data conductive strips 122 and addressing conductive strips 124 are located in the interstitial spaces 127.
Referring now to FIGS. 4 and 5 there is shown a top view of a single sensor 111 and an elevation cross section of the sensor taken along arrows 5--5 in FIG. 4. The sensor comprises a dielectric substrate 109 such as a glass substrate. On the substrate 109 there is placed a bottom microplate 112 which is preferably transparent to erasing radiation. When visible spectrum radiation is used in the step of erasing the panel the microplate 112 is preferably transparent to visible radiation. Microplate 112 may be a thin layer of Indium Tin Oxide.
A dielectric insulating layer 113 is deposited over both the gate 116 and the bottom microplate 112. A top microplate 114 is deposited over the dielectric layer 113. Top microplate 114 is substantially coextensive and parallel with the bottom microplate 112. Microplates 112 and 114 together with dielectric 113 form a capacitor.
As shown in FIG. 4, microplates 112 and 114 provide a cutout section 117 at one end, where there is located a switching element such as a TFT transistor 115.
The TFT switching element 115 is constructed in the cutout area 117 using well known technology. In brief, construction of the TFT transistor involves first depositing a gate electrode 116 on the glass plate support 109 and an electrical connection from the gate to the address strip 124. This is followed by the deposition of a semiconductor material 119 on a portion of the gate 116, and two electrodes, the drain electrode 118 and the source electrode 120. The drain and source electrodes are spaced to create a channel space which is filled with a dielectric 121 (see FIG. 5).
Drain electrode 118 is directly connected to the top microplate 114 and source electrode 120 is directly connected to data strip 122.
A dielectric layer 121 is next placed over the TFT switch and the interstitial spaces 127 (shown in FIG. 3) covering all conductive elements or strips and extending to cover at least the edge of top microplate 114. The dielectric layer 121 may overlap a portion of the microplate 114 without effecting the scope of the present invention. Provided there is an opening in the dielectric layer 121 for connecting the collector strip 128 to the top microplate 114, the dielectric layer 121 may extend over the full top microplate 114 area without effecting the scope of the present invention.
Over this layer 121 there is next placed an additional charge collector conductive strip 128 which covers completely the area over the TFT switch. The additional charge collector strip 128 preferably also extends over a portion of the interstitial areas 127 (shown in FIG. 3) and terminates above and opposite the top microplate 114 edge, thus forming a ring like structure which begins where the top microplate ends and extends the useful area of the microplate to the area occupied by the TFT switching element and up to, and optionally into, the non-imaging interstitial spaces without creating a double thickness microplate structure. A connecting strip of electrical conductor 129 is used to provide an electrical conductive path connection between the additional charge collector 128 and the top microplate 114.
The structure described above is preferred, however, only when the precision requirements in masking technology to place the additional charge collector 128 exactly opposite the point where the top microplate ends is far too expensive to be commercially attractive. It has been found that a compromise where the additional charge collector is designed to slightly overlap the top microplate 114 provides substantially all of the benefits of the ideal design without significant deleterious side effects. Such slight overlap is shown in FIGS. 4 and 5.
Following deposition of the additional charge collector 128, the panel is coated with a photoconductive layer 130 such as Selenium, and the photoconductive layer is overcoated with top electrode 132. As is well known in the art, additional insulating and/or passivation layers may be provided between the photoconductive layer and any conductive surfaces it may otherwise be in contact with.
FIGS. 6 and 7 depict an alternate embodiment of a sensor 111' wherein the top microplate 114' and the additional charge collecting strip 128' are combined into a single electrode. This is done by bringing the dielectric layer 121 to the edge of top microplate 114'. Next, a conductive layer which extends over the TFT transistor and in the space between the top microplate 114' and the interstitial spaces is deposited over the dielectric layer 121, to form a continuous layer extending along the dielectric layer edge 134 to the top microplate 114'. In this manner there is formed a single charge collecting top microplate which extends continuously over two levels to maximize the charge collecting surface of the pixel. Of course this two level microplate may be created by a single metal deposition following the deposition of the dielectric layers 121 and 113.
The photoconductor layer 130 and top electrode 132 are again deposited over the sensors as before. This structure is advantageous because (1) it avoids any overlap of the top microplate 114' by the additional charge collector 128', and (2) does not leave any areas uncovered.
In the above description, the additional charge collector 128 is always shown to extend around the perimeter of each sensor. While such design maximizes the effective image capture area of the sensor, the charge collector can of course extend only partially around the top microplate. Similarly, the charge collector is shown to extend partially over the interstitial spaces. Again this is not essential but is done to maximize the active image area of the sensor.
This invention has been described in terms of a sensor wherein there is a switching element included with every sensor and wherein such element is a TFT transistor built with the gate electrode in contact with the substrate. However, the present invention is not limited to the particular switch used for its illustration; an inverted TFT switch could be readily substituted without altering the claimed scope. Furthermore, the switching element does not have to be a TFT transistor but any switching element or combination of elements, present in the sensor or its vicinity, which results in decreasing the available effective image capturing area of the sensor is, for purposes of this invention, to be treated as being the same as the TFT switch disclosed and encompassed by my invention. Those having the benefit of the teachings hereinabove set forth may modify the specific sensor structure and various elements or relative placement thereof and such modifications are to be construed as being within the scope of my invention. | An image capture panel particularly useful in radiographic application is disclosed, in which the active image capture area of individual sensors having top and bottom charge collecting microplates arrayed in rows and columns is extended by providing an additional charge capture conductive strip over sensor areas which are not normally covered by a charge collecting microplate. The strip may be made integral with the top microplate or may be separate and electrically connected thereto at a single point. | 7 |
BACKGROUND OF THE INVENTION
The present invention involves a method and apparatus for utilizing selvage or scrap from polyacrylonitrile (PAN) film manufacturing operations. In processing polymeric films of various types for orientation by stretching the film, a certain amount of edge portions, ends and other film scrap is generated during the manufacturing process. In some production lines it is not unusual to have 10 to 30% or more selvage materials, which should be utilized in making valuable product if the manufacturing facility is to be economic.
Various processes have been devised for using marginal strips and waste products from extruded film. In U.S. Pat. No. 4,013,745 a typical prior art system reprocesses scrap by severing and recycling it to an extruder screw inlet, along with virgin polymer. The two materials are dissolved in a common solvent and fed in a unitary stream through a sheeting die to form a film. While such reprocessing techniques are feasible for certain products, they are not suitable for recycling PAN resin for use in high-performance films.
In forming a film sheet or foil of PAN resin, gas barrier properties and appearance are important qualities of the product dependent upon uniformity of composition. Where only virgin PAN resin is employed with pure solvent in constituting the extrusion mass, homogeneous solutions can be obtained without undue processing. PAN resins may be synthesized in the solvent and used without being recovered as discrete solid particles. Also, finely divided powders of acrylonitrile homopolymers and interpolymers are relatively easy to dissolve completely, due to their small particle size, usually 1 to 15 microns. When recycling scrap or selvage resin, however, it is difficult to obtain such fine subdivision by ordinary chopping, grinding or other comminution processes. Recycled resin solids may have a size and shape which render the material difficult to handle and present problems in solvent penetration during dissolution. Even with the use of auxiliary equipment, such as homogenizers, filters, etc., it is impractical to obtain completely homogeneous solutions of the recycle resin suitable for mixing with the virgin PAN feedstock. Very small amounts of undissolved resin can provide heterogeneities and film discontinuities when cast as a single layer, especially when casting a thin film. Localized stresses due to such imperfections may result in uneven stretching, pinholes or tears in the film, which are unacceptable for gas barrier service and affect appearance adversely.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a multi-layer film comprising polyacrylonitrile or the like formed of contiguous layers of non-homogeneous and homogeneous resin materials having good film integrity. The system provides means for extruding at least two streams of resinous material as discrete layers. This may be achieved by multiple die means which extrude the resins in laminar flow relationship. The extruded resin, usually in hot concentrated solution form, is solidified to form a film, as by cooling and coagulation. The film is oriented by stretching and dried to remove volatile matter. Cutting means removes the edge trim and produces a finished film product. Resin scrap is recycled by comminuting and dissolving the resin to form a non-homogeneous material for re-extrusion as a discrete layer.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cross-sectional view of a film segment;
FIG. 2 is a schematic diagram of a typical system for solvent casting of multilayer film;
FIG. 3 is a cross-sectional view of a film segment having virgin resin, recycled resin and a thermoplastic layer;
FIG. 4 is a cross-sectional view of an alternative film segment having a layer of recycled PAN, virgin PAN and thermoplastic heat seal layer; and
FIG. 5 is a schematic drawing of a preferred process for casting polyacrylonitrile film with organic solvent and aqueous washing media.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, metric units and parts by weight are used unless otherwise stated.
Referring to the drawing, in FIG. 1 is shown a typical multilayer film 1 including a layer 2 of homogeneous resin and a contiguous layer 3 of non-homogeneous resin, containing small particles 4 of undissolved material.
This film can be manufactured by employing the casting and scrap recovery system shown in FIG. 2. The initial hot solution of resin and solvent is mixed and homogenized in makeup station 10 and passes through pump means 20 to casting drum 30 via first sheeting die 31, which lays down a soldified layer of virgin resin. Casting drum 30 is maintained sufficiently cool to solidify the resin, forming a uniform layer. A second layer is cast from tandem sheeting die 32, spaced apart from the first die 31. The coagulated film 1 is stripped from drum 30 as a self-supporting continuous multilayer film strip. Thereafter, the multilayer film is passed through a series of operatively connected processing units, which include solvent removal means 40, stretching means 50 to provide an oriented structure, drying means 70 to remove volatile components of the cast film, trimming means 80 for removing excess resin from the marginal portions of the stretched film as selvage, and winding means 81 for product film. The trimmed selvage and other mill scrap is then chopped and/or ground in suitable comminuting means 82 and fed to screening unit 83 or other suitable means for separating large scrap particles for further size reduction. The smaller particles, having a suitable size for subsequent handling, are admixed with hot solvent in dissolver unit 84 and passed through filter means 85 to retain over-sized particles suspended in the non-homogeneous resin solution. The hot scrap solution is then recycled to the second sheeting die 32.
While the system can be adapted to handle a wide variety of scrap materials from various points in a film production plant, a main source of recycled material is the selvage obtained from edge trimming operations and slitting scrap. This is usually in the form of a thin sheet material, having thickness of 0.5 to 2 mils (12-50 microns), typically. By chopping, severing or otherwise cutting the film, thin flake-like particles can be obtained having a relatively small thickness dimension, but rather large planar dimensions of several millimeters may be produced. The present system is well-adapted for redissolving these flake film particles by admixing the comminuted material with hot solvent. Although the non-homogeneous resin supply can be more dilute than the homogeneous supply, it is desirable to optimize the process with the least amount of solvent that will produce satisfactory multilayer film. Hot DMSO solvent with PAN homopolymer scrap can be successfully recycled with only 15 to 30 wt% resin. If greater quantities of solvent are required, solvent removal before extrusion may be required to assure film integrity. The dissolution step may be performed by high-shear equipment or the like to disperse and dissolve the scrap resin. Large solids may be further dispersed with compression-type equipment or "homogenizers" to provide a non-plugging stream of recycled resin. A screen-type filter can be employed to retain oversized particles that might be larger than the film extrusion thickness.
Certain types of extruders can handle initially-larger recycled particles and still produce satisfactory extrudate. In some screw-type equipment, dry recycled resin can be compressed as a low bulk feedstock and redissolved with hot solvent as it advances along the path of the screw means.
The relative thickness of layers may be fixed or varied according to available scrap resin being generated and reprocessed. Where the virgin PAN supply is unlimited, the continuous production rate for single-resin film can be met for a wide range of scrap content from none to the upper limit of film integrity. About 5 to 25 microns (0.2 to 1 mil) gives satisfactory performance for the individual layers of typical film used in wrapping food or other articles. Total finished PAN film thickness of about 10 to 20 microns forms a good gas barrier for oxygen and water vapor.
It is possible to extrude the PAN homopolymer on both sides and at each edge of a multilayer film, as shown in FIG. 3. The inner core layer 3 may comprise the non-homogeneous selvage extrusion composition. A system for co-extruding triple-layer film with beaded edges is disclosed in U.S. Pat. No. 3,448,183. The edge bead facilitates stretching the film by tentering and can be trimmed from the product following orientation. It may be feasible to employ selvage as the outer layer in some circumstances, with homogeneous PAN solution being injected as the core layer.
Polyacrylonitrile polymers containing very large amounts of homopolymeric units do not melt at practical heat-sealing temperatures. The homopolymer can be cast or extruded by solution techniques; but, once coagulated, the resulting articles cannot be fused effectively by heat alone. When it is desired to impart heat sealing properties to PAN film, this may be accomplished by introducing a suitable comonomer with acrylonitrile; such as an interpolymer of C 4 -C 8 alkylacrylate and/or other thermoplastic component with acrylonitrile. Unfortunately, significant amounts of such comonomers as butylacrylate degrade the gas barrier characteristics of polyacrylonitrile. However, it may be desirable to incorporate 10-20% alkylacrylate in at least one layer of the film.
In one aspect of the invention shown in FIG. 4, an adhering thermoplastic layer 5 is co-extruded with the virgin PAN layer 2 and recycled PAN layer 3 to obtain a multilayer orientable film having heat sealing properties. Advantageously, this is achieved by a three-orifice die by feeding homogeneous PAN solution to an outer orifice, recycled non-homogeneous PAN selvage solution to a middle orifice, and a compatible thermoplastic material to the other outer orifice. This results in a three-layer film having its weaker inside layer protected by the outer layers during stretching.
The present invention also provides manufacture of multilayer film from selvage or scrap containing at least one substantially non-thermoplastic polyacrylonitrile component. For instance, if the product film has one layer of PAN homopolymer to provide low oxygen and water vapor permeability and a thermoplastic co-extruded heat seal layer of 20% butylacrylate--80% acrylonitrile copolymer, the selvage can be ground and redissolved in DMSO or suitable cosolvent to provide the non-homogeneous layer. Numerous variations in materials can be included in the film within the inventive concept.
In a preferred embodiment of the invention, the multilayer film is extruded from an extrusion die having a plurality of manifolds for supplying the different resinous streams to a common flow passage from which the film-forming material is extruded at elevated temperature onto an adjacent cold casting roll. Flow control means is provided for feeding the individual resinous streams continuously at predetermined uniform rates, which establish the relative thicknesses of the discrete layers. At flow rates at which laminar flow prevails, fluid streams combine without substantial intermixing between layers and give a uniform film. Suitable multilayer extrusion die assemblies are disclosed in U.S. Pat. Nos. 3,559,239 and 4,165,210, incorporated herein by reference. The layers may be formed sequentially by tandem die means wherein the layers are extruded individually onto a moving surface, one being cast onto a cold roll and one or more subsequent layers being cast over the initial layer.
In addition to casting of planar films onto drums or the like, multilayer tubular films may be formed with concentric orifices. For instance, in U.S. Pat. No. 4,144,299, PAN film is produced by extruding an organic solution into an aqueous coagulation bath while water is introduced into and withdrawn from the inside of the extruded tube. By appropriate modification of the orifice to provide two or more concentric layers, scrap ma be utilized in making tubular film.
While the inventive concept may be employed in ordinary solvent-plasticized film stretching operations, in recent years an improved aqueous washing system has been developed which gives high quality PAN film. The details of this system are disclosed in U.S. Pat. No. 4,066,731, incorporated herein by reference. This system, as adapted for use herein, is shown in FIG. 5. The homogeneous solution of PAN in dimethyl sulfoxide (DMSO) is introduced as a hot casting dope containing 30 to 40% PAN through a pump to multiple sheeting die 132, where it is co-extruded as a multilayer film onto the cold casting drum 130, wetted with an aqueous solution of DMSO. The solidified film 101 is then contacted with an aqueous solution of DMSO 123, which is passed countercurrently through a wash tank 140. The film is stripped from the drum continuously and procedes through the wash tank 140 wherein the DMSO migrates out of the film and is replaced by water in the interstices of the film. By stretching the wet film longitudinally in the machine direction in heated differential roll means 150, the film is axially oriented. This is followed by transverse hot stretching in stream or water vapor environment in tenter section 160. Thereafter, the film is dried under constraint by radiant and/or convection means in drier section 170. The marginal areas are cut from the product in slitting line 180, with edge trim being recycled to comminuter 182 and fed through hopper 186 and conveyor 188 to screw-type extruder 126. The weighed scrap, now in a flaked film state is admixed with a metered amount of hot DMSO, which may be introduced at various points along the compression path of the extruder. Since the scrap PAN is a low bulk material, it is sometimes desirable to introduce at least part of the DMSO toward the feed section of the extruder 126, from which the mixture is fed to multiple sheeting die 132 for coextrusion with the virgin PAN solution.
Operating temperatures for the redissolution step with DMSO are generally maintained elevated in the range of about 110° to 175° C., preferably at about 150° C. The amount of solvent required will depend upon the scrap composition and solubility parameters of the solvents. Rather large amounts of solvent must be employed to obtain complete dissolution of the polymer, requiring an expensive evaporation step to concentrate the resin to 30-40%. It is a significant advantage of the present invention that complete solution of the resin is not required, resulting in small inhomogeneities. At the point of extrusion, the largest undissolved particles for most film applications would be about 25 microns or less, depending upon the extrusion equipment and film dimensions. In addition to DMSO, various organic solvents or co-solvent mixtures, such as dimethyl formamide, tetramethylene sulfone or other campatible solvents may be employed. Water miscibility is desirable where the aqueous washing step is employed between the casting and orienting steps. The solvent may be recovered from the various processing units and separated for reuse.
While the invention has been disclosed by particular examples, there is no intent to limit the inventive concept except as set forth in the following claims. | A novel system for producing film by extruding and/or casting at least two layers of resin, such as polyacrylonitrile homopolymer or interpolymers. The system provides for co-extruding a continuous multi-layer film with contiguous or tandem dies from a first supply of homogeneous resin solution and a second supply of non-homogeneous redissolved resin scrap. The film may be cast onto a smooth cooled drum surface to form substantially continuous adjacent layers from two or more resin supplies. By stripping the film from the drum as a continuous film strip and stretching the film an oriented structure is provided. Scrap resin, such as selvage trimmed from the stretched film or mill scrap, is comminuted and redissolved in solvent for recycle to the second supply of the extrusion step. The homogeneous layer prevents film disruption by inhomogeneities present in the contiguous layer containing redissolved scrap, which might cause localized stresses in the film and discontinuities during stretching. | 1 |
BACKGROUND
1. Field of the Invention
This invention relates to toilet seats, specifically to an improved toilet seat positioner which provides a choice of grasping portions while still maintaining a sanitary means of raising and lowering the seat.
BACKGROUND
2. Cross-Reference to Related Applications
Three design patent applications for toilet seat positioners have been filed for, by me, on the following dates;
Nov. 18, 1991, #07/793210, Toilet Seat Positioner
Dec. 6, 1991, #07/802778 Toilet Seat Positioner
Dec. 6, 1991, #07/803396, Toilet Seat with Integrated Positioner
BACKGROUND
3. Discussion of Prior Art
Heretofore toilet seat positioners were concerned primarily with hygiene; protecting the users fingers from contacting the bottom of the toilet seat and the rim of the toilet bowl. The prior art has failed to adequately take into consideration the decorative, aesthetic, and novel value of a toilet seat positioner. The basic functional aspect of the positioner has been addressed in prior art but its ornamental value as a bathroom fixture has been overlooked; thereby explaining why the toilet seat positioner has not gained general acceptance even though an obviously unsanitary condition would be corrected by its use.
Nakajima, U.S. Pat. No. 4,574,401, 1986, has a removable handle as does Vaughan et al., U.S. Pat. No. 4,129,907, 1978, but neither for the purpose of creating decorative or aesthetic options; Nakajima to install a cover and Vaughan for cleaning.
OBJECTS AND ADVANTAGES
It is an object of this invention to provide an improved toilet seat positioner, one that gives decorative, aesthetic, and novel options while continuing to provide the user with a clean and hygienic means of positioning the toilet seat.
Another object of this invention is to provide a sanitary toilet seat positioner which is simple in construction, economical to manufacture, affording convenient changeability and coupling of the grasping portion without the need of hand tools.
Another object of this invention is to allow the implementation of an almost unlimited array of objects, be they personal, sentimental, or novel, to be used as the grasping portion of the toilet seat positioner.
Another object of this invention is to allow the grasping portion to incorporate in its structure various utilitarian and novel devices which will add practical and amusement value to the toilet seat positioner.
With the above and other objects in view, the present invention consists of the combination and arrangement of parts herein more fully described, and illustrated in the accompanying drawings, and more particularly, that changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, closely related figures have the same number but different alphabetic suffixes;
FIG. 1 is a top plan view, with hidden lines, of a toilet seat positioner in combination with a toilet seat;
FIG. 2 is an isometric view, with hidden lines, of the toilet seat positioner;
FIG. 3A is a partial, sectional, elevated, transverse view taken along the section lines of 3A--3A in FIG. 2 of the toilet seat positioner;
FIG. 3B is a sectional, isometric view taken along the section lines of 3B--3B in FIG. 2 of the grasping portion;
FIG. 4A is a top plan view of a base structure with a shaft;
FIG. 4B is a top plan view of an annular flexible retainer;
FIG. 4C is a sectional, elevated, transverse view taken along the section lines of 3A--3A in FIG. 2 of the grasping portion;
FIG. 5A is an isometric partial view of the shaft;
FIG. 5B is a sectional, elevated, transverse view taken along the section lines of 3A--3A in FIG. 2 of an alternate embodiment of grasping portion;
FIG. 5C is a sectional, isometric, view taken along the section lines of 5C--5C in FIG. 5B of an alternate embodiment of the grasping portion;
FIGS. 6A to 6E show elevated, isometric, transverse, sectional, and hidden line views of alternate embodiments of a grasping portion adapter;
FIGS. 7A to 7D show elevated, transverse, sectional, with hidden line views, of an alternate embodiment of a grasping portion housing a warning light.
FIGS. 8A and 8B illustrate schematically, an electric circuit encased in grasping portion with warning light shown in FIGS. 7A to 7D;
FIG. 9 shows an elevated, transverse view of an alternate embodiment of grasping portion housing floating particles;
FIGS. 10A and 10B show a top and transverse plan with hidden line views of an oval, or egged shape grasping portion;
FIG. 10C shows an elevated, transverse view of oval shape;
FIGS. 11A and 11B show a top plan and transverse elevation of a modified geodesic shaped grasping portion;
FIGS. 12A and 12B show a top plan and transverse elevation of a modified diamond shaped grasping portion;
FIGS. 13A shows a front elevation, 13B a transverse elevation, 13C an isometric view of a half sphere of a grasping portion;
FIGS. 14A shows a top plan, 14B a transverse elevation, 14C a front elevation of an attached double half circle of a grasping portion;
FIGS. 15A and 15B show a front and transverse elevation of two ovals intersecting to form grasping portion;
FIGS. 16A and 16B show isometric and transverse elevation of a round edged disc, grasping portion;
FIGS. 17A shows a top plan, 17B a rear elevation, and 17C a front elevation of a bowed round rod intersected in the middle with a straight round rod;
FIGS. 18A shows a top plan, 18B a rear elevation, and 18C a front elevation of a bowed round rod;
FIGS. 19A shows a top plan, 19B an isometric view of a bowed angled rail.
DESCRIPTION
Now with particular reference to the drawings, FIG. 1 is a typical toilet seat 22 with a toilet seat positioner 32 attached to one side. The positioner can be attached to either or both sides of the seat. FIG. 2 shows a toilet seat positioner, base structure 30, being planar, with a modified rectangle shape, terminating in a shaft 48 with a square spline 46. The base structure and shaft may be constructed of any acceptable material, such as wood, plastic, or metal. FIG. 2 shows a grasping portion 34 as a modified square, or cube shape.
FIGS. 3A, 3B, 4A, 4B, and 4C show a sectional view of the base structure 30 and shaft 48. A square spline 46, a retaining ring 42, and a retaining ring groove 36 around the shaft make up the complete shaft. Also shown is a cube shaped grasping portion 34 with a smooth bore 44. The smooth bore allows free rotation of the grasping portion. An annular groove 40 in the smooth bore allows the grasping portion to be retained on the shaft when the retaining ring is in place. The grasping portion bore is sized incrementally to accommodate the shaft 48. The annular groove 40 in the bore engages the retaining ring 42 when the grasping portion girdles the shaft 48.
An adhesive 31 and mechanical fastener holes 37 are shown. The adhesive surface of the base structure 30 is attached to the underside of the toilet seat. In addition a further mechanical fastening is often desirable. A screw connection, preferable a flat head screw, with a taper corresponding to the beveled edges of the screw holes 37 can be used.
FIGS. 5A, 5B, 5C, show the shaft 48 with retaining ring 42, and square spline 46. The grasping portion 34 in these views has a spline bore 50 thus allowing for a fixed position of the grasping portion when coupled to the shaft. The fixed position being desirable in certain embodiments of this invention.
FIGS. 6A to 6E show an alternate embodiment of this invention. The grasping portion 34 in this embodiment is a small diameter round rod shaped portion with both smooth 44 and spline 50 bores to allow both free rotation and fixed position, when connected to the shaft. In addition to being a grasping portion this, now called a grasping portion adapter 60, will allow an unlimited number of objects to be interchangeably used as grasping portions simply by drilling a hole in an object and inserting the grasping portion adapter with some form of adhesive on it into the drilled hole. The only limitations on the object to be used as a grasping portion are size, and weight. Also, any object desired as a permanent grasping element can be permanently coupled to the base structure 30 shaft 48 by boring a hole in the object the same size as the outside diameter of the shaft. Then applying adhesive to the coupler shaft, and sliding the desired object onto the shaft.
FIGS. 7A to 7D show another embodiment of the invention. A grasping portion with warning light 70 is shown as a sphere, but can take any acceptable shape. A spline bore 50 is used with this embodiment because of the necessity to maintain fixed positions needed for proper operation of a mercury switch 74. When the toilet seat is in the horizontal, down position, the mercury switch 74 is in the non-conducting position and the L. E . D., 72 is off. When the toilet seat is raised to the vertical, up position, the mercury switch 74 is in the conducting position and the L.E.D. 72 is on. The person using the toilet is now being warned to return the toilet seat to the horizontal position when finished. But if the seat is inadvertently left in the vertical position with the L.E.D., 72 on, it still serves as a warning to the next person using the toilet. In the dark the light is visible and can prevent someone from accidentally sitting on the toilet bowl rim. FIG. 7C shows the mercury switch in a conducting position. A wafer battery 76 and L.E.D. 72 are also shown. FIGS. 7B and 7D show the grasping portion with warning light, the mercury switch being in the non-conducting position.
FIGS. 8A and 8B show an electric circuit schematically, a L.E.D. 72, a mercury switch 74, a wafer battery 76, and conducting connections 78. The elements of this embodiment are permanently encased in molded plastic.
FIG. 9 shows another embodiment of the invention in the form of a sphere, but need not be limited to such shape, which contains a liquid with free floating particles. The elements of this embodiment are encased in plastic.
FIGS. 10A to 10C show an alternate shaped embodiment with hidden lines of both smooth and spline bores.
FIGS. 11A to FIGS. 19B show alternate shaped embodiments. All of these embodiments can have either smooth or splined bores.
OPERATION
The base structure 30 of the toilet seat positioner 32 will permit attachment to the bottom of a toilet seat with either adhesive or mechanical fastening method. The coupling action of the shaft 48 and the grasping position 34 is accomplished by sliding the grasping portion 34 onto the shaft 48 until the shaft's 48 retaining ring 42 is engaged by the annular grove 40 in the grasping portion's 34 bore. Once the shaft's 48 retaining ring 42 has meshed with the grasping portion's annular grove 40 the grasping portion is now held in place on the shaft. The shaft 48 will allow immediate coupling of the grasping portion 34, and if the grasping portion has a smooth bore 44, free rotation, since the spline on the shaft is by-passed If the grasping portion has a spline bore 50, the spline on the shaft will be utilized when coupled and the grasping portion will maintain a fixed position. Thus the interchangeability, position, and coupling of the grasping portion is assured.
With the grasping portion adapter 60 embodiment, FIGS. 6A to 6E, an infinite number of optional objects may be employed as grasping elements. A hole drilled the size of the outside diameter of the grasping portion adapter and an adhesive is all that is necessary to convert an object into a readily exchangeable grasping portion 34.
Additionally, any object not limited by size or weight can be permanently coupled to the shaft 48 by drilling the object with a hole the size of the outside diameter of the shaft, coating the shaft with adhesive, and sliding the object onto the shaft. Also the shaft itself can be used as a grasping portion if desired.
The grasping portion with warning light 70 embodiment serves as a warning light when the seat is left in an up, vertical, position, thereby preventing someone from accidentally sitting on the toilet bowl rim. The mercury switch 74 energizes the L.E.D. 72 from the wafer battery 76, through the conducting circuit 78, in this vertical position, FIG. 8B. When the seat is lowered, to horizontal, the conducting circuit is de-energized and the L.E.D. goes out, FIG. 8A. The mercury switch is now in the non-conducting position. This embodiment is replaceable with a new unit when the battery dissipates.
In the embodiment of the grasping portion, housing floating particles, the particles will be stationary with no movement of the toilet seat positioner and toilet seat. When the toilet seat is moved the particles will be disturbed and become suspended in the liquid; slowly settling as time passes, thus creating a novel effect. Either a smooth or spine bore can be used with this embodiment. Additionally the depiction of any object, whether by a miniature replication, a picture, or symbol of such object, can be encased in clear plastic of any desired shape.
SUMMARY, RAMIFICATIONS, AND SCOPE
The toilet seat positioner allows a multitude of available grasping portions to be used in combination with a toilet and toilet seat. The grasping portion can take the form of decorative, aesthetic, novel, amusement, or utilitarian purpose when used in combination with the base structure and shaft.
Although the description above contains many specifics these should not be construed as limiting the scope of the invention but merely providing illustrations of some of the presently preferred embodiments of this invention. For example a small transistor radio could become a grasping portion, as could a smoke alarm An object such as a golf ball that has acquired novel value could be mounted. As could a miniature fire hydrant replication be mounted by a firefighter to add novelty to the bathroom decor.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. | A toil seat positioner 34 attachable to the underside of a toilet seat for the purpose of manually positioning the toilet seat in a sanitary manner. The positioner's base structure 30 with shaft 48 facilitates coupling of the grasping portion 34 for rotational or fixed positions. The interchangeability of manufactured grasping portions 34 allow for a plurality of grasping portions. Additionally, any desired object not limited by size or weight can become a changeable grasping portion by employing the grasping portion adapter 60, or become a permanent grasping portion by securing directly to the shaft 48. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention generally relate to methods and apparatus for use in oil and gas wellbores. More particularly, the invention relates to an isolation valve with debris control and flow tube protection.
2. Description of the Related Art
An isolation valve is located as part of the casing string and operated through a control line. The isolation valve is configured to temporarily isolate a formation pressure below the isolation valve such that a tool string may be quickly and safely tripped into a portion of the wellbore above the isolation valve that is temporarily relieved to atmospheric pressure. Thus, the isolation valve allows the tool string to be tripped into and out of the wellbore at a faster rate than snubbing in the tool string under pressure. Since the pressure above the isolation valve is relieved, the tool string can trip into the wellbore without wellbore pressure acting to push the tool string out.
The isolation valve is movable between an open position and a closed position by selectively actuating a flapper valve of the isolation valve. The flapper valve is actuated by the movement of a flow tube in the isolation valve. In the closed position, the flapper valve obstructs a bore through the isolation valve, and in the open position, the flapper valve resides in a flapper valve cavity. Prior designs for the isolation valve can suffer from various disadvantages. One disadvantage of prior designs is that debris and mud may enter the flapper valve cavity during operation of the isolation valve. The debris and mud may inhibit the function of the flapper valve and thereby affect the opening and/or closing of the isolation valve. Another disadvantage of prior designs is that an end of the flow tube oftentimes becomes damaged while stripping or tripping the drill string through the isolation valve. The damaged flow tube may subsequently cause damage to the flapper valve as the flow tube moves through the isolation valve. Therefore, there exists a need for an improved isolation valve assembly and associated methods.
SUMMARY OF THE INVENTION
The present invention generally relates to an isolation valve with debris control. In one aspect, an isolation valve for use as part of a casing string is provided. The isolation valve includes a housing having a bore and a valve cavity. The isolation valve further includes a valve member movable between a first position in which the valve member obstructs the bore of the housing and a second position in which the valve member is disposed in the valve cavity. Further, the isolation valve includes a flow tube configured to allow movement of the valve member between the first and second positions. Additionally, the isolation valve includes an engagement assembly adapted to engage the flow tube to substantially prevent debris from entering the valve cavity when the valve member is in the second position.
In another aspect, a method of operating an isolation valve in a wellbore is provided. The method includes the step of placing the isolation valve in the wellbore. The isolation valve includes a housing, a valve member, a flow tube, a piston and an engagement assembly. The method further includes the step of moving the valve member into a bore of the housing to obstruct a flow path through the isolation valve. The method also includes the step of moving the flow tube into interference with the valve member to open the flow path through the isolation valve. Additionally, the method includes the step of moving the flow tube into engagement with the engagement assembly to protect the valve member from debris.
In yet a further aspect, an isolation valve is provided. The isolation valve includes a housing having a bore. The isolation valve further includes a flapper pivotally movable between a closed position in which the bore is blocked and an opened position in which the bore is open to fluid flow. The isolation valve also includes a movable flow tube for shifting the flapper between the opened position and the closed position. Additionally, the isolation valve includes an engagement assembly adapted to engage the flow tube when the flapper is in the opened position.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a cross-section view of an isolation valve in an open position, according to one embodiment of the invention.
FIGS. 1A and 1B are enlarged views of the isolation valve illustrated in FIG. 1 .
FIG. 2 is a cross-section view of the isolation valve in a closed position.
FIGS. 2A and 2B are enlarged views of the isolation valve illustrated in FIG. 2 .
FIG. 3 is a cross-section view of the isolation valve in a locked position.
FIGS. 3A and 3B are enlarged views of the isolation valve illustrated in FIG. 3 .
FIG. 4 is a cross-section view of an isolation valve in an open position, according to one embodiment of the invention.
FIGS. 4A and 4B are enlarged views of the isolation valve illustrated in FIG. 4 .
FIG. 5 is a cross-section view of the isolation valve in a closed position.
FIGS. 5A and 5B are enlarged views of the isolation valve illustrated in FIG. 5 .
FIG. 6 is a cross-section view of the isolation valve in a locked position.
FIGS. 6A and 6B are enlarged views of the isolation valve illustrated in FIG. 6 .
FIGS. 7A-7C illustrate a hinge arrangement for a flapper valve.
FIG. 8 is a cross-section view of an engagement assembly.
DETAILED DESCRIPTION
Embodiments of the present invention generally relate to an isolation valve with flow tube protection. The isolation valve may be a downhole deployment valve or a formation deployment valve. To better understand the aspects of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings.
FIG. 1 shows a cross-section view of an isolation valve 100 in an open position to thereby enable tools such as a drill string to pass through a longitudinal central bore 110 of the isolation valve 100 . The isolation valve 100 includes an outer housing 115 with a flow tube 120 disposed within the housing 115 . The flow tube 120 represents an exemplary mechanism for moving a flapper 105 to open and close the isolation valve 100 , although other types of actuators may be used in some embodiments. In one embodiment, the flapper 105 may be biased in toward the closed position and may reside in a flapper cavity 165 when in the open position. The flow tube 120 may move within the housing 115 based on control signals received to selectively displace the flapper 105 between the open position and the closed position. The flow tube 120 moves across an interface between the flapper 105 and a seat 130 to engage and urge the flapper 105 to the open position or disengage and allow the flapper to return to the closed position. As will be described herein, the flow tube 120 covers the flapper 105 when the isolation valve 100 is in the open position to at least inhibit debris and drilling fluid from collecting around the flapper 105 and the flapper cavity 165 . Build-up of solids between a backside surface of the flapper 105 and the housing 115 can impede the flapper 105 from moving to the closed position after withdrawing the flow tube 120 out of interference with the flapper 105 .
The isolation valve 100 includes control line connections 125 at an end of the housing 115 that are in communication with control lines (not shown). The control lines provide fluid via fluid channels 235 , 240 to first and second piston chambers 135 , 140 that are defined between the housing 115 and the flow tube 120 . A piston 175 spans an annular area between the housing 115 and the flow tube 120 to define and isolate the first and second chambers 135 , 140 from one another. The piston 175 is movable to change the relative sizes of the chambers 135 , 140 .
As shown in FIG. 1A , the piston 175 is attached to the flow tube 120 via a releasable member 150 , such as a shear pin. Fluid pressure can be introduced into the second piston chamber 140 through the channel 240 to act on the piston 175 . The fluid pressure moves the piston 175 and the attached flow tube 120 in a first direction to open the isolation valve 100 . In this respect, the flow tube 120 contacts the flapper 105 and urges the flapper 105 toward the flapper cavity 165 . To return to the closed position, fluid pressure is introduced in the first piston chamber 135 via the channel 235 to act on the piston 175 . The fluid pressure moves the piston 175 and the attached flow tube 120 in a second opposite direction to slide the flow tube 120 out of interference with the flapper 105 . The isolation valve 100 may be movable between the open position and the closed position multiple times by introducing fluid pressure in the respective piston chamber 135 , 140 . As also shown in FIG. 1A , a biasing member 160 is disposed between the flow tube 120 and the piston 175 . The biasing member 160 is configured to allow the flow tube 120 to move relative to the piston 175 by compressing the biasing member 160 . The biasing member 160 may be an elastomer, a spring or any other type of biasing member known in the art. As also shown in FIG. 1A , a lock member 205 (such as a lock ring) is disposed within the housing 115 . The lock member 205 is compressed and held in place by a shear ring 210 . As will be discussed herein, the lock member 205 is configured to interact with a groove 215 in the flow tube 120 when the isolation valve 100 is moved to a locked position ( FIG. 3 ).
As shown in FIG. 1B , the isolation valve 100 further includes an engagement assembly 170 . The engagement assembly 170 is configured to interact with the flow tube 120 when the isolation valve 100 is in the open position in order to protect (and/or seal) the flapper cavity 165 from debris. In this respect, the engagement assembly 170 may be placed below the flapper cavity 165 . In one embodiment, the engagement assembly 170 includes a guide member 180 and a sleeve member 195 that are interconnected via a shearable member 190 . The guide member 180 may include a tapered inner surface that is configured to centralize a drill string and/or other tools passing through the isolation valve 100 . In addition, the engagement assembly 170 is configured to protect the end of the flow tube 120 from damage due to the movement of the drill string and other tools through the isolation valve 100 . In this embodiment, the engagement assembly 170 may absorb impact from the drill string because it is the first (or lowest) component in the isolation valve 100 , which is in contact with the drill string as the drill string moves upward through the bore 110 of the isolation valve 100 , the engagement assembly 170 substantially shields the flow tube 120 from any damage that may occur. In addition, the engagement assembly may direct the drill string (using the tapered surface) into the inner diameter of the flow tube 120 , thereby protecting the end profile of the flow tube 120 . The engagement assembly 170 may also direct debris into the inner diameter of the flow tube 120 to prevent packing off of the flapper cavity 165 . In this manner, the engagement assembly 170 may shield the flow tube 120 from damage that may occur as the drill string or fluid moves upward through the bore 110 of the isolation valve 100 .
During opening of the isolation valve 100 , the piston 175 moves the flow tube 120 in a direction toward the engagement assembly 170 when fluid pressure is introduced into the second piston chamber 140 via the channel 240 . The flow tube 120 continues in the direction until a lower portion 155 of the flow tube 120 contacts an upper portion 185 of the guide member 180 . In one embodiment, the lower portion 155 of the flow tube 120 includes a shaped surface, such as a bull-nosed shape, which is configured to contact with a surface on the upper portion 185 of the guide member 180 . In one embodiment, the surface on the upper portion 185 is shaped to mate with the shaped surface. The flow tube 120 and the guide member 180 are optionally biased against each other to maintain contact between the flow tube 120 and the guide member 180 after the isolation valve 100 is in the open position. In the embodiment illustrated, the biasing member 160 ( FIG. 1A ) is used to bias the flow tube 120 against the guide member 180 of the engagement assembly 170 . In another embodiment, a biasing member may be placed in between the components of the engagement assembly 170 . In further embodiment, a biasing member may be placed in the engagement assembly 170 and in the flow tube 120 . The biased contact arrangement is optionally used to maintain contact between the flow tube 120 and the guide member 180 , and in this manner the flapper cavity 165 is protected from debris that may restrict the operation of the flapper 105 .
FIG. 2 illustrates a cross-section view of the isolation valve 100 in a closed position. As shown, the flapper 105 is obstructing the longitudinal central bore 110 through the isolation valve 100 . To close the isolation valve 100 , fluid pressure is supplied to the first piston chamber 135 (see FIG. 2A ) via the channel 235 , which moves the flow tube 120 out of interference with the flapper 105 . Because the flapper 105 is biased toward the seat 130 , movement of the flow tube 120 out of interference with the flapper 105 allows the flapper 105 to move toward the seat 130 . The seat 130 is a portion of the isolation valve 100 that engages the flapper valve 105 when the isolation valve 100 is in the closed position. The seat 130 may be part of the housing 115 , or the seat 130 may be a separate component in the isolation valve 100 . Additionally, as the flow tube 120 moves through the housing 115 , the flow tube 120 disengages from the guide member 180 of the engagement assembly 170 (see FIG. 2B ).
FIG. 3 illustrates a cross-section view of the isolation valve 100 in a locked position. As set forth herein, the isolation valve 100 is movable between the open position and the closed position multiple times by introducing fluid pressure in the respective piston chamber 135 , 140 . The isolation valve 100 may be locked in the open position by manipulating the location of the flow tube 120 . The flow tube 120 includes inner mating profiles 145 that enable engagement of the flow tube 120 with a corresponding profile tool (not shown) for manipulating the location of the flow tube 120 . To permit free movement of the flow tube 120 relative to the piston 175 , a predetermined force is required to break the releasable member 150 between the flow tube 120 and the piston 175 . Upon application of the predetermined force using the profile tool, the releasable member may break into a first portion 150 A and a second portion 150 B (see FIG. 3A ). Thereafter, the flow tube 120 is allowed to move through the housing 115 a distance that is greater than a distance traveled when the isolation valve 100 is moved to the open position. As the flow tube 120 moves through the housing 115 , the groove 215 moves to a location adjacent the lock member 205 to allow the lock member 205 to engage the groove 215 . Upon engagement of the lock member 205 in the groove 215 , the flow tube 120 is locked in the open position, and the flow tube 120 will no longer be able to move to close the isolation valve 100 . In addition, as the flow tube 120 moves through the housing 115 , the sleeve contacts and acts on the guide member 180 , which causes the shearable member 190 to shear. Thereafter, the guide member 180 moves relative to the sleeve member 195 until the guide member 180 contacts a shoulder 220 , as shown in FIG. 3B , to accommodate the extra travel required for the flow tube 120 during the locking operation.
FIG. 4 shows a cross-section view of another embodiment of an isolation valve 300 . Similar to the isolation valve 100 , the isolation valve 300 includes an engagement assembly 370 that is configured to interact with a flow tube 320 disposed within a housing 315 . The engagement assembly 370 and the flow tube 320 interact when the isolation valve 300 is in the open position in order to protect (and/or seal) a flapper cavity 365 from debris that may restrict the operation of a flapper valve 305 . The flow tube 320 is also used to allow a flapper valve 305 to open and close the isolation valve 300 .
The isolation valve 300 includes control line connections 325 that are in communication with control lines (not shown). The control lines provide fluid to first and second piston chambers 335 , 340 via fluid channels 470 , 475 . The first piston chamber 335 (see FIG. 5 ) and the second piston chamber 340 (see FIG. 4 ) are defined between the housing 315 and a piston sleeve 375 . A piston sleeve 375 is movable in response to the introduction of fluid into the piston chambers 335 , 340 . The piston sleeve 375 includes a first piston surface 435 and a second piston surface 440 .
As shown in FIG. 4A , the piston sleeve 375 is connected to the flow tube 320 via a releasable member 350 . As will be described herein, the releasable member 350 will release the connection between the piston sleeve 375 and the flow tube 320 when the isolation valve 300 is moved to the locked position.
Referring back to FIG. 4 , the isolation valve 300 is in the open position, which allows drill string and/or other tools to pass through a longitudinal central bore 310 of the isolation valve 300 . To move the isolation valve 300 to the open position, fluid pressure is introduced into the second piston chamber 340 via the fluid channel 470 . The fluid pressure in the second piston chamber 340 acts on the second piston surface 440 of piston sleeve 375 , which moves the flow tube 320 in a first direction to open the isolation valve 300 . To return to the closed position, fluid pressure is introduced in the first piston chamber 335 via the fluid channel 475 , and the fluid pressure acts on the first piston surface 435 of the piston sleeve 375 which moves the flow tube 320 in a second opposite direction to slide the flow tube 320 out of interference with the flapper valve 305 . In this manner, the isolation valve 300 is movable between the open position and the closed position multiple times by introducing fluid pressure in the respective piston chamber 335 , 340 .
As shown in FIG. 4A , a biasing member 360 is disposed between the flow tube 320 and the piston sleeve 375 . The biasing member 360 is configured to allow the flow tube 320 to move relative to the piston sleeve 375 by compressing the biasing member 360 . In one embodiment, the biasing member 360 is a wave spring. In other embodiments, the biasing member 360 may be an elastomer, a helical spring or any other type of biasing member known in the art. As also shown in FIG. 4A , a lock member 405 , such as a lock ring, is disposed within the flow tube 320 . The lock member 405 is compressed and held in place by a shear ring 410 disposed around an outer surface of the flow tube 320 . As will be discussed herein, the lock member 405 is configured to interact with a groove 415 in the housing 315 when the isolation valve 300 is moved to a locked position.
FIG. 4B is an enlarged view of the engagement assembly 370 . The engagement assembly 370 is configured to interact with the flow tube 320 when the isolation valve 300 is in the open position to substantially protect a flapper cavity 365 from debris that may restrict the operation of the flapper valve 305 . As shown, the engagement assembly 370 includes a guide member 380 and a sleeve member 395 that are interconnected via a shearable member 390 . In one embodiment, the guide member 380 includes a tapered surface that is configured to centralize a drill string and/or other tools passing through the longitudinal central bore 310 of the isolation valve 300 . In addition, the engagement assembly 370 is configured to protect the end of the flow tube 320 from damage due to the movement of the drill string and other tools upward through the isolation valve 300 . Since the engagement assembly 370 is the first (or lowest) component in the isolation valve 300 , which is in contact with the drill string as the drill string moves upward through the bore 310 of the isolation valve 300 , the engagement assembly 370 substantially shields the flow tube 320 from any damage that may occur.
As set forth herein, the piston sleeve 375 moves the flow tube 320 in a direction toward the engagement assembly 370 when fluid pressure is introduced into the second piston chamber 340 from the fluid channel 470 . The flow tube 320 moves within the housing 315 until a lower portion 355 of the flow tube 320 is in contact with an upper portion 385 of the guide member 380 . In one embodiment, the lower portion 355 of the flow tube 320 includes a shaped surface, such as a bull-nosed shape, which is configured to mate with a corresponding shaped surface on the upper portion 385 of the guide member 380 . The flow tube 320 and the guide member 380 are optionally biased against each other to maintain contact between the flow tube 320 and the guide member 380 while the isolation valve 300 is in the open position. In the embodiment illustrated, the biasing member 360 ( FIG. 4A ) is used to bias the flow tube 320 against the guide member 380 of the engagement assembly 370 . In other embodiments, the biasing member 360 may be placed at other locations in the isolation valve 300 , such as between the components of the engagement assembly 370 . In another embodiment, there may be more than one biasing member at various locations in the isolation valve 300 . In this manner, the biased contact arrangement is used to maintain contact between the flow tube 320 and the guide member 380 to protect the flapper cavity 365 from debris that may restrict the operation of the flapper valve 305 .
FIG. 5 illustrates a cross-section view of the isolation valve 300 in a closed position. As shown, the flapper valve 305 is obstructing the longitudinal central bore 310 through the isolation valve 300 . To move the isolation valve 300 to the closed position, fluid pressure is supplied to the first piston chamber 335 through the fluid channel 475 , which acts on the first piston surface 435 of the piston sleeve 375 to move the flow tube 320 out of interference with the flapper valve 305 . The flapper valve 305 is biased toward the seat 330 . Therefore, the movement of the flow tube 320 out of interference with the flapper valve 305 allows the flapper valve 305 to move toward the seat 330 . In addition, the movement of the flow tube 320 through the housing 315 causes the flow tube 320 to disengage from the guide member 380 of the engagement assembly 370 (see FIG. 5B ).
FIG. 6 illustrates a cross-section view of the isolation valve 300 in a locked position. The isolation valve 300 is movable between the open position and the closed position multiple times by introducing fluid pressure in the respective piston chamber 335 , 340 . The isolation valve 300 may also be locked in the open position by manipulating the location of the flow tube 320 by mechanical force. The flow tube 320 includes inner mating profiles 345 that enable engagement of the flow tube 320 with a corresponding profile tool (not shown) for manipulating the location of the flow tube 320 . To permit free movement of the flow tube 320 relative to the piston sleeve 375 , a predetermined force is required to break the releasable member 350 between the flow tube 320 and the piston sleeve 375 . Upon application of the predetermined force, the releasable member breaks 350 into a first portion 350 A and a second portion 350 B (see FIG. 6A ), which allows the flow tube 320 to move relative to the piston sleeve 375 . In addition, the application of the predetermined force shears the ring 410 . The movement of the flow tube 320 through the housing 315 also moves the lock member 405 to a location adjacent the groove 415 in the housing, and thereafter the lock member 405 engages the groove 415 . The flow tube 320 is locked in the open position upon engagement of the lock member 405 in the groove 415 . At this point, the flow tube 320 will no longer be able to move through the housing 315 to close the isolation valve 300 . As shown in FIG. 6B , the movement of the flow tube 320 through the housing causes the flow tube 320 to contact and act on the guide member 380 , which causes the member 390 to shear. Thereafter, the guide member 380 moves relative to the sleeve member 395 to accommodate the extra travel required for the flow tube 320 during the locking operation.
FIGS. 7A-7C illustrate a hinge arrangement 425 for the flapper valve 305 . As shown in FIG. 7A , the hinge arrangement 425 connects the flapper valve 305 to the housing 315 . During the manufacturing process of the isolation valve 300 , the flapper valve 305 is aligned to allow for proper engagement of the flapper valve 305 and the seat 330 . The seat 330 may be part of the housing 315 , or the seat 330 may a separate component in the isolation valve. The design permits for small alignment movement along a seat/hinge mating surface 430 due to the connection members. Once the hinge arrangement 425 is aligned, the hinge arrangement 425 is fastened to the housing 315 by a plurality of connection members 420 , such as screws. Further, an adjustment locking connection member 445 may be used to fine tune the alignment of the hinge arrangement 425 and/or to prevent axial direction movement along the plane of the seat/hinge mating surface 430 . As shown in FIG. 7C , the adjustment locking connection member 445 is attached to a portion of the housing 315 , and the adjustment locking connection member 445 is tightened in a direction along the plane of the seat/hinge mating surface 430 and therefore prevents axial direction movement along the plane of the seat/hinge mating surface 430 . Additionally, as shown in FIG. 7C , a safety connection member 495 , such as a screw, snap ring or pin, is disposed at a location adjacent the adjustment locking connection member 445 . The safety connection member 495 is configured to substantially prevent the adjustment locking connection member 445 from inadvertently falling out during operation of the flapper valve 305 . Although the hinge arrangement 425 was described in relation to the flapper valve 305 , the hinge arrangement 425 applies to other valves such as the flapper 105 .
FIG. 8 is a cross-section view of an engagement assembly 450 . The engagement assembly 450 functions in a similar manner as described herein with regards to the engagement assemblies 170 , 370 . The primary difference is that the engagement assembly 450 is made from a single piece rather than two pieces (e.g., guide member and sleeve member). The engagement assembly 450 is attached to the housing 315 via a connection member 460 , such as a resilient connection member (e.g. o-ring) or a non-resilient connection member (e.g. shear screw). One advantage of the connection member 460 being a resilient connection is that the connection member 460 may be used to bias the engagement assembly 450 in contact with the flow tube 320 while the isolation valve 300 is in the open position. The engagement assembly 450 includes a tapered surface 465 . The engagement assembly 450 is configured to take impact from a drill string and direct the drill string (using the tapered surface 465 ) into the inner diameter of the flow tube 320 , thereby protecting the end profile of the flow tube 320 . The engagement assembly 450 also directs debris into the inner diameter of the flow tube 320 to prevent packing off of the flapper cavity 365 .
Similar to as described herein, the engagement assembly 450 is configured to interact with the flow tube 320 when the isolation valve 300 is in the open position in order to protect the flapper cavity 365 from debris that may restrict the operation of a flapper valve 305 . To maintain contact between the flow tube 320 and the engagement assembly 450 while the isolation valve 300 is in the open position, one or both of the flow tube 320 and the engagement assembly 450 are biased toward each other. Additionally, when the isolation valve 300 is moved to the locked position, the flow tube 320 contacts and acts on the engagement assembly 450 , which causes the member 460 to shear to accommodate the extra travel required for the flow tube 320 during the locking operation.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally relates to an isolation valve with debris control. In one aspect, an isolation valve for use as part of a casing string is provided. The isolation valve includes a housing having a bore and a valve cavity. The isolation valve further includes a valve member movable between a first position in which the valve member obstructs the bore of the housing and a second position in which the valve member is disposed in the valve cavity. Further, the isolation valve includes a flow tube configured to allow movement of the valve member between the first and second positions. Additionally, the isolation valve includes an engagement assembly adapted to engage the flow tube to substantially prevent debris from entering the valve cavity when the valve member is in the second position. In another aspect, a method of operating an isolation valve in a wellbore is provided. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to the field of integrated circuits. More particularly, this invention relates to integrated circuits with copper interconnects and low-k dielectrics.
BACKGROUND OF THE INVENTION
[0002] It is well known that integrated circuits (ICs) consist of electrical components such as transistors, diodes, resistors and capacitors built into the top layer of a semiconductor wafer, typically a silicon wafer. It is also well known that these components are electrically connected to form useful circuits by metal interconnects consisting of several layers of horizontal metal lines and vertical metal vias, separated by dielectric materials. A major concern in interconnect fabrication is to minimize the resistance and capacitance of the interconnects in order to maximize the operating speed of the circuits in the ICs. Copper metal is used to form the interconnects, because copper has lower electrical resistance than the previously used interconnect metal, aluminum. Additionally, the dielectric materials with lower dielectric constants than silicon dioxide, such as organo-silicate glass, collectively known as low-k dielectric materials, are used to electrically insulate copper interconnects from each other. Low-k dielectric materials achieve their low dielectric constants (relative to silicon dioxide) by using several techniques; one technique is substitution of lighter elements for silicon and oxygen; another is increased porosity (voids have a dielectric constant very close to 1.00). Most low-k dielectric materials utilize both of these techniques.
[0003] Regions in the dielectric layers for horizontal metal lines and vertical metal vias are etched to remove the dielectric material, prior to depositing metal in the desired regions. Maintaining well defined patterns for interconnects during etching is challenging.
[0004] Layers of denser, more etch resistant dielectric, known as hard masks are deposited on low-k dielectric layers to maintain desired lateral dimensions of interconnect patterns during etching. There are several requirements of hard mask layers. One requirement is an ability to withstand an etch cycle which removes low-k dielectric material down to a lower metal level. Another is to minimize remaining hard mask material after etching is completed, to minimize capacitive coupling between adjacent metal lines. A third is to provide good adhesion to photolithographic materials, typically an organic anti-reflective material, known as BARC (bottom anti-reflective coating). To meet these requirements, a layer of silicon nitride or silicon carbide nitride is often used with a layer of silicon dioxide for adhesion to BARC.
[0005] It is also well known that the lateral dimensions of components in ICs, including interconnect linewidths and via diameters, are on a downward trend over time. The minimum interconnect feature sizes, known as critical dimensions (CDs), of recent ICs are below 100 nm. These features are defined photolithographically with light that has wavelengths close to the desired CD, using photoresists that can convert said light into a well defined mask for etching underlying layers. Photoresists rely on amine compounds to convert molecules that are insoluble in a photodeveloper to molecules that are soluble in the developer. These resists are commonly known as amplified resists. A problem arises with the use of dielectric layers containing nitrogen, such as silicon nitride, in combination with low-k dielectrics and amplified resists. Nitrogen can diffuse out of the nitrogen containing dielectric film into the low-k dielectric material and into the photoresist, and interfere with the proper action of the amine molecules in the amplified photoresist. This phenomenon is known as resist poisoning. Resist poisoning can distort the photolithographically defined features of interconnects, resulting in narrow or interrupted horizontal metal lines, which in turn cause circuit failures and reliability problems. This problem is often addressed by providing an additional layer to hard mask stacks, comprising a layer, typically composed of silicon dioxide, to retard diffusion of nitrogen from other hard mask layers into low-k dielectric materials.
[0006] Photoresist thickness is significantly reduced by etching through hard mask layers, because three layers require significant time to etch through. This is disadvantageous because loss of photoresist imposes tighter requirements on control of lateral dimensions in via patterning, which increases cost and complexity of via patterning.
[0007] Photoresist thickness is reduced even more by etching through low-k dielectric material, and photoresist may be completely removed before low-k dielectric etching is completed. This is disadvantageous because loss of photoresist degrades the topography of hard mask layers around etched regions, for example via regions in a via-first process, which degrades the profile of metal trench in an ensuing trench etch.
[0008] Nitrogen containing films in via etch stop layers can also contribute to resist poisoning. Adding nitrogen blocking layer to via etch stop stacks results in more difficult etch control and increased capacitive coupling between adjacent metal lines.
SUMMARY OF THE INVENTION
[0009] This Summary is provided to comply with 37 C.F.R. §1.73, requiring a summary of the invention briefly indicating the nature and substance of the invention. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
[0010] This invention comprises a method for forming an integrated circuit comprising a silicon carbide doped oxide (SiCO) film for use in single and dual damascene copper interconnect fabrication. The SiCO film of this invention is formed using various gases, including 100 to 2000 sccm hydrogen, 100 to 2000 sccm helium, 100 to 2000 sccm tri-methyl silane and 100 to 1000 sccm carbon dioxide, resulting in a stoichiometry of 28 to 46 atomic percent silicon, 26 to 44 atomic percent carbon, 19 to 35 atomic percent oxygen. In one embodiment, a layer of SiCO replaces multiple layer metal hard masks. In another embodiment, a layer of SiCO is added to via etch stop layer stacks.
DESCRIPTION OF THE VIEWS OF THE DRAWING
[0011] FIG. 1A is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after via 1 pattern in a dual damascene full via-first process sequence.
[0012] FIG. 1B is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching through a metal 2 hard mask in a dual damascene full via-first process sequence.
[0013] FIG. 1C is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching a via 1 hole in a dual damascene full via-first process sequence.
[0014] FIG. 1D is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching metal 2 trench and via 1 etch stop in a dual damascene full via-first process sequence.
[0015] FIG. 2 is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching metal 2 trench in a single damascene process sequence.
DETAILED DESCRIPTION
[0016] Silicon carbide doped oxide (SiCO) films are generated in a plasma reactor using gases that include 100 to 2000 standard cubic centimeters per minute (sccm) of hydrogen, 100 to 2000 sccm of helium, 100 to 2000 sccm of tri-methyl silane and 100 to 1000 sccm of carbon dioxide. A plasma comprising these gases is maintained at 200 to 900 watts of RF power, at a pressure of 2 to 8 torr. The stoichiometry of the resulting SiCO film is 28 to 46 atomic percent silicon, 26 to 44 atomic percent carbon, 19 to 35 atomic percent oxygen, and less than 2 atomic percent of other elements (if present) such as nitrogen, hydrogen, etc.
[0017] FIG. 1A is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after via 1 pattern in a dual damascene full via-first process sequence. An IC ( 100 ) provides a substrate ( 102 ), in which are formed an n-type region known as an n-well ( 104 ) and a p-type region known as a p-well ( 106 ). Components in the IC ( 100 ) are electrically isolated by field oxide ( 108 ), typically composed of silicon dioxide, and typically formed by local oxidation of silicon (LOCOS) or shallow trench isolation (STI). In said p-well is formed an n-channel MOS (NMOS) transistor ( 110 ), comprising an n-channel gate dielectric ( 112 ), n-channel gate ( 114 ), n-channel sidewall spacer ( 116 ) and n-channel source and drain regions ( 118 ). Similarly, in said n-well is formed an p-channel MOS (PMOS) transistor ( 120 ), comprising an p-channel gate dielectric ( 122 ), p-channel gate ( 124 ), p-channel sidewall spacer ( 126 ) and p-channel source and drain regions ( 128 ).
[0018] Still referring to FIG. 1A , a pre-metal dielectric (PMD) layer stack is formed on a top surface of the IC, comprising a PMD liner ( 130 ), a PMD ( 132 ) and contact cap layer ( 134 ). Electrical connection to the NMOS and PMOS transistors is made by contacts ( 136 ), typically comprised of tungsten, formed through the PMD liner ( 130 ), PMD ( 132 ) and contact cap layer ( 134 ). On a top surface of the contacts ( 136 ) and contact cap layer ( 134 ) is formed intra-level 1 low-k dielectric ( 138 ) and metal 1 hard mask ( 140 ), and metal 1 comprising metal 1 liner metal ( 142 ) and metal 1 fill metal ( 144 ), typically copper. A via 1 etch stop first dielectric ( 146 ), typically silicon carbide nitride, is deposited, followed by a layer of silicon carbide doped oxide (SiCO) ( 148 ), 10 to 60 nanometers thick, in accordance with an embodiment of the instant invention, which acts as a nitrogen blocking layer to prevent nitrogen in the via 1 etch stop first dielectric ( 146 ) from contributing to resist poisoning. The SiCO layer ( 148 ) also serves as a part of a via 1 etch stop, allowing a thin layer of via 1 etch stop first dielectric ( 144 ) to be used. A layer of intra-level 1 dielectric ( 150 ), typically low-k material, is deposited over the via 1 etch stop first dielectric and via 1 etch stop second dielectric layers. A metal 2 hard mask layer ( 152 ) is comprised of a single layer of SiCO, 5 to 100 nanometers thick, in accordance with another embodiment of the instant invention. BARC ( 154 ) and photoresist ( 156 ) layers are formed, and a via 1 pattern ( 158 ) is defined photolithographically.
[0019] FIG. 1B is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching through a metal 2 hard mask in a dual damascene full via-first process sequence. The metal 2 hard mask layer ( 152 ) has been etched in via 1 regions ( 160 ) as defined by a photoresist pattern ( 158 ). The as deposited thickness of the photoresist ( 156 ) is maintained during the SiCO hard mask etching, due to the reduced time it takes to etch through a single layer of SiCO. This is advantageous because retention of more photoresist allows more process margin (coating thickness, exposure and depth of focus range) in via 1 patterning processes, reducing costs and improving yields during IC fabrication.
[0020] FIG. 1C is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching a via 1 hole in a dual damascene full via-first process sequence. A via 1 hole ( 162 ) has been extended down to the via 1 etch stop 2 layer ( 148 ), forming a slight recess ( 164 ) in the SiCO layer of the via 1 etch stop 2 dielectric ( 148 ). Some photoresist ( 156 ) may remain after via etch.
[0021] FIG. 1D is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching metal 2 trench and via 1 etch stop in a dual damascene full via-first process sequence. Trench patterning does not suffer from resist poisoning because the SiCO via 1 etch stop second dielectric ( 148 ) blocks the nitrogen from the underlying via 1 etch stop first dielectric ( 146 ). The via stop etch process removed the etch stop materials ( 146 , 148 ) in a via hole ( 162 ) down to the metal 1 fill metal ( 144 ). SiCO, as used in the via 1 etch stop second dielectric ( 148 ), has a better selectivity to the via etch, so a thinner layer of via 1 etch stop first dielectric ( 146 ) can be used. This is advantageous, because it produces less undercutting of a trench profile ( 166 ) in the low-k dielectric, which increases process margins of a metal 2 liner metal deposition process. The SiCO hard mask layer ( 152 ) is thinner than the SiO2 nitrogen blocking layer used currently and is advantageous, because it also increases the process margins of the metal 2 liner metal deposition process.
[0022] It will be readily apparent to practitioners of integrated circuit fabrication that the advantages of a SiCO via etch stop layer and a SiCO single layer hard mask are applicable to all interconnect levels comprising low-k dielectrics, dual damascene processing, amplified photoresist processing and nitrogen bearing dielectrics in via etch stop layers.
[0023] It will also be apparent to practitioners of integrated circuit fabrication that the advantages of a SiCO etch stop layer and a SiCO single layer hard mask are applicable when implemented in a single damascene process. FIG. 2 is a fragmentary, diagrammatic sectional view on an enlarged scale of a cross-section of an integrated circuit including MOS transistors and metal 1 , via 1 and metal 2 interconnect regions in embodiments of the instant invention, depicted after etching metal 2 trench in a single damascene process sequence. An IC ( 200 ) provides a substrate ( 202 ), in which are formed an n-type region known as an n-well ( 204 ) and a p-type region known as a p-well ( 206 ). Components in the IC ( 200 ) are electrically isolated by field oxide ( 208 ), typically composed of silicon dioxide, and typically formed by local oxidation of silicon (LOCOS) or shallow trench isolation (STI). In said p-well is formed an n-channel MOS (NMOS) transistor ( 210 ). Similarly, in said n-well is formed a p-channel MOS (PMOS) transistor ( 212 ). A pre-metal dielectric (PMD) layer stack is formed on a top surface of the IC, comprising a PMD liner ( 214 ), a PMD ( 216 ) and contact cap layer ( 218 ). Electrical connection to the NMOS and PMOS transistors is made by contacts ( 220 ), typically comprised of tungsten, formed through the PMD liner ( 214 ), PMD ( 216 ) and contact cap layer ( 218 ). On a top surface of the contacts ( 220 ) and contact cap layer ( 218 ) is formed intra-level 1 low-k dielectric ( 222 ) and metal 1 hard mask ( 224 ), and metal 1 comprising metal 1 liner metal ( 226 ) and metal 1 fill metal ( 228 ), typically copper. A via 1 etch stop first dielectric ( 230 ), typically silicon carbide nitride, is deposited, followed by a via 1 etch stop second dielectric ( 232 ) comprised of a layer of silicon carbide doped oxide (SiCO), 10 to 60 nanometers thick, in accordance with an embodiment of the instant invention, which acts as a nitrogen blocking layer to prevent nitrogen in the via 1 etch stop first dielectric ( 230 ) from contributing to resist poisoning. The use of SiCO in the via 1 etch stop second dielectric ( 232 ) allows a thin layer of via 1 etch stop first dielectric ( 230 ) to be used. A layer of inter-level 1 dielectric ( 234 ), typically low-k material, is deposited over the via 1 etch stop first dielectric and via 1 etch stop second dielectric layers. A via 1 hard mask layer ( 236 ) is comprised of a single layer of SiCO, 5 to 100 nanometers thick, in accordance with another embodiment of the instant invention. A set of via 1 interconnects are formed by etching defining via 1 regions photolithographically and etching through the via 1 hard mask layer ( 236 ), inter-level 1 dielectric ( 234 ) and via 1 etch stop first and second dielectric layers ( 232 , 230 ), depositing via 1 liner metal ( 238 ) and via 1 fill metal ( 240 ), typically copper. A trench 2 etch stop first dielectric ( 242 ), typically silicon carbide nitride, is deposited, followed by a trench 2 etch stop second dielectric ( 244 ), comprised of a layer of silicon carbide doped oxide (SiCO), 10 to 60 nanometers thick, in accordance with an embodiment of the instant invention, which acts as a nitrogen blocking layer to prevent nitrogen in the trench 2 etch stop first dielectric ( 242 ) from contributing to resist poisoning. The use of SiCO in the trench 2 etch stop second dielectric ( 244 ) allows a thin layer of trench 2 etch stop first dielectric ( 242 ) to be used. A layer of intra-level 2 dielectric ( 246 ), typically low-k material, is deposited over the trench 2 etch stop first dielectric ( 242 ) and trench 2 etch stop second dielectric ( 244 ) layers. A trench 2 hard mask layer ( 248 ) is comprised of a single layer of SiCO, 5 to 100 nanometers thick, in accordance with another embodiment of the instant invention. Trench 2 regions are defined photolithographically and etched through the trench 2 hard mask layer ( 248 ), intra-level 2 dielectric ( 246 ), and trench 2 etch stop first and second dielectrics ( 242 , 244 ). | Interconnects of integrated circuits (ICs) utilize low-k dielectrics, copper metal lines, dual damascene processing and amplified photoresist chemistry to build ICs with features smaller than 100 nm. Photolithographic processing of interconnects with these elements are subject to resist poisoning from nitrogen in etch stop and hard mask dielectric layers. Attempts to solve this problem cause lower IC circuit performance or higher fabrication process cost and complexity. This invention comprises a method of fabricating interconnects in an IC using layers of silicon carbide doped oxide (SiCO) in a via etch stop layer, in a trench etch stop layer, as a via etch hard mask and as a trench etch hard mask. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a wiper ring to be mounted to an end portion of a nut of a ball screw and also relates to a ball screw provided with such wiper ring.
Japanese Utility Model Laid-open Publication No. HEI 6-6795 disclosed such a wiper ring, in which one end side portion or entire portion of a wiper ring is divided into a plurality of segments or blocks in a circumferential direction thereof, and each of the segments is pressed towards radially center side by means of spring to thereby improve tightness between an inner peripheral portion of the wiper ring and a screw shaft disposed inside therein.
In such known art, in the structure in which only the one end side portion of the wiper ring is divided into a plurality of segments or blocks, there is usually formed a cutout portion, called “bias-cut”, at one portion of the wiper ring in its circumferential direction for separating the same. However, in an arrangement in which such wiper ring is mounted to a screw shaft, the bias-cut portion is widened (opened) and the inner peripheral portion of the wiper ring is deformed unwillingly in form of non-circular shape, and for this reason, at a portion opposite to the bias-cut forming portion of the wiper ring, the segment is closely contacted to the screw shaft. However, on the side of the bias-cut forming portion, the tightness of the segment to the screw shaft is made worse. As a result, sealing performance of the ball screw may be made different at various portions, thus being inconvenient.
On the other hand, the case where the entire portion of the wiper ring is divided into a plurality of segments or blocks will cause the following defective.
In such structure, when a gap is formed between adjacent two segments in the circumferential direction thereof, the gap may be widened when the segments are shifted. In such occasion, foreign material or like may easily invade and lubricant may easily leak through the widened gap. On the contrary, when the segments are contacted to each other in order to eliminate such gap, the movement of the respective segment towards the radially central portion of the segment due to such mutual contacting will be limited, which results in degradation of tightness between the segments and the screw shaft and deterioration of the sealing performance. Furthermore, in a case where any foreign material is clogged between the segment and the screw shaft, the segment is displaced towards the radially outer peripheral side against the force of the spring pressing the segment, and hence, the inner peripheral portion of the segment is separated from the screw shaft, thus deteriorating the sealing performance and hence being defective.
SUMMARY OF THE INVENTION
An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a wiper ring and a ball screw provided with the wiper ring, by which sealing performance of a screw shaft with respect to segments of the wiper ring can be enhanced.
The above and other objects can be achieved according to the present invention by providing, in one aspect, a wiper ring to be applied to a screw unit having a shaft member comprising:
a plurality of segments each constituted as independent element having a seal portion to be contacted to the shaft member;
support shafts extending in an axial direction of the shaft member so as to correspond to the segments, respectively, the segments being arranged in a circumferential direction of the shaft member to be rotatable about the support shafts, the support shafts being connected to each other through support members so as to limit relative movement of the respective support shafts; and
a spring member for urging the segments arranged circumferential direction of the shaft member so as to be directed towards radially central side of the shaft member.
According to the wiper ring of this aspect, the respective segments are deformed in their attitudes so as to closely contact the shaft member such as screw shaft of the ball screw unit while being pressed towards the central side of the screw member by means of spring and rotating about the support shafts such as pins. Accordingly, the respective segments can be well contacted to the shaft member, and the improved sealing performance can be realized at any circumferential position.
Further, the support shafts of the respective segments are mutually connected to thereby limit or restrict the relative movement of the support shafts, so that the movement of the segments in the circumferential and radial directions can be properly limited. Therefore, the biting of foreign material in a widened gap between the segments in the circumferential direction can be prevented, the leakage of lubricant can be also prevented, and the degradation of the sealing performance due to the movement of the segments in the radially outer peripheral direction can be further prevented.
Further, in the present invention, the state, that the support shafts as rotational centers of the respective segments are connected to each other, means that the support shafts are connected to each other through members different from the segments or through the segments themselves to thereby restrict the relative movement therebetween. The support shafts may be constituted independently from the segment, or segment itself is utilized as support shaft.
In a preferred embodiment of this aspect, the support member is a support ring formed as a member independent from the segments and the support shafts are connected to each other through the support ring.
In this example, the respective segments are supported by the support ring to be rotatable about the support shafts such as pins. The support ring may be separated at one portion in its circumferential direction, and in such case, since the cut portion corresponding to the bias-cut in the conventional structure of the wiper ring is formed on the support ring, the wiper ring can be entirely deformed and the segments can be surely urged against the shaft member by the spring member.
Furthermore, according to this aspect, (N−2) segments in the plural segments (N: total number thereof are formed with the support shafts and hole portions for receiving the support shafts in an arrangement shifted in the circumferential direction of the shaft member, either one of remaining two (2) segments is provided with the support shaft and another one of the remaining two segments being formed with the hole portion, the segments being connected to each other by fitting the support shafts to the hole portions of the adjacent two segments in the circumferential direction in a manner that the remaining two segments are unconnected.
According to this example, the respective adjacent segments can be supported to be rotatable about the support shafts and the respective support shafts can be connected through the segments. Therefore, no connection is made between two segments, so that the cut (separated) portion, corresponding to the conventional bias-cut, is formed and the wiper ring can be entirely deformed. Thus, the segments can be surely urged against the shaft member by the spring member.
Furthermore, it may be possible that each of the segments comprises a segment body having the seal portion and a support plate arranged in a manner shifted in the circumferential direction with respect to the segment body, either one of the support plate and the segment body is formed with the support shaft and another one thereof is formed with the hole portion.
In this example, since the support plate extends behind a slit formed between the segment bodies, so that the inside and outside portions of the wiper ring are not communicated through the slit, and hence, the invasion of foreign material can be prevented as well as leakage of the lubricant.
In another aspect of the present invention, there is also provided a wiper ring to be applied to a screw unit having a shaft member comprising:
a support ring;
a plurality of segments each having a seal portion to be contacted to the shaft member, the segments being arranged on one side of the support ring in a circumferential direction of the support ring and connected to each other to be rotatable about a predetermined support shaft with respect to the support ring; and
a spring member for urging the segments arranged in the circumferential direction of the support ring towards radially central side of the support ring.
According to the wiper ring of this aspect, substantially the identical advantageous effects to those mentioned above will be achieved. That is, since the respective segments can be supported by the support ring to be rotatable about the support shafts such as pins, the respective segments are deformed in their attitudes so as to closely contact the shaft member such as screw shaft of the ball screw unit while being pressed towards the central side of the screw member by means of spring and rotating about the support shafts such as pins. Accordingly, the respective segments can be well contacted to the shaft member, and the improved sealing performance can be realized at any circumferential position.
Further, the support shafts of the respective segments are mutually connected through the support ring to thereby limit or restrict the relative movement of the support shafts, so that the movement of the segments in the circumferential and radial directions can be properly limited. Therefore, the biting of foreign material in a widened gap between the segments in the circumferential direction can be prevented, the leakage of lubricant can be also prevented, and the degradation of the sealing performance due to the movement of the segments in the radially outer peripheral direction can be further prevented.
The support ring may be separated at its one portion in the circumferential direction, and in such case, the cut (separated) portion, corresponding to the conventional bias-cut, is formed on the support ring, so that the wiper ring can be entirely deformed. Thus, the segments can be surely urged against the shaft member by the spring member.
In this aspect, a slit may be formed between adjacent segments when the segments are connected to the support ring.
In a further aspect, there is provided a wiper ring to be applied to a screw unit having a shaft member comprising:
a plurality of segments each having a seal portion to be contacted to the shaft member, the segments being arranged in a circumferential direction of the shaft member; and
a spring member for urging the segments arranged in the circumferential direction of the shaft member in the radially central direction of the shaft member,
wherein (N−2) segments in the plural segments (N: total number thereof) are formed with support shafts extending in an axial direction of the shaft member and hole portions for receiving the support shafts in an arrangement shifted in the circumferential direction of the shaft member, either one of remaining two segments is provided with the support shaft and another one of the remaining two segments being formed with the hole portion, the segments being connected to each other by fitting the support shafts to the hole portions of the adjacent two segments in the circumferential direction in a manner that the remaining two segments are unconnected.
According to the wiper ring of this aspect, the respective adjacent segments are supported to be rotatable about the support shafts such as pins, so that the respective segments are deformed in their attitudes so as to closely contact the shaft member such as screw shaft of the ball screw unit while being pressed towards the central side of the screw member by means of spring and rotating about the support shafts. Accordingly, the respective segments can be well contacted to the shaft member, and the improved sealing performance can be realized at any circumferential position.
Further, the support shafts of the respective segments are mutually connected to thereby limit or restrict the relative movement of the support shafts, so that the movement of the segments in the circumferential and radial directions can be properly limited. Therefore, the biting of foreign material in a widened gap between the segments in the circumferential direction can be prevented, the leakage of lubricant can be also prevented, and the degradation of the sealing performance due to the movement of the segments in the radially outer peripheral direction can be further prevented.
Furthermore, the connection between the adjacent two segments is interrupted, the cut (separated) portion, corresponding to the conventional bias-cut, is formed on the support ring, so that the wiper ring can be entirely deformed. Thus, the segments can be surely urged against the shaft member by the spring member.
In this aspect, a slit is formed between adjacent segments when the respective segments are connected.
In still further aspects of the present invention, there are provided ball screw or ball screw units each comprising:
a screw shaft;
a number of rolling members to be applied to the screw shaft;
a nut mounted to the screw shaft through the rolling members; and
a wiper ring mounted to at least one axial end portion of the nut, the wiper ring comprising the elements or members mentioned above with respect to first, another and further aspects of the present invention.
According to the ball screw (unit) utilizing the wiper ring of the above aspects, the wiper ring is mounted to at least one end portions of the nut, so that the durability of the nut against the foreign material or like can be achieved with the improved sealing performance of the wiper ring.
Further, it is to be noted that the nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a developed perspective view of a ball screw according to one embodiment of the present invention;
FIG. 2 is an illustration showing a relationship between a support ring of a wiper ring utilized for the ball screw of FIG. 1 and a segment;
FIG. 3 is a developed sectional view of the wiper ring utilized for the ball screw of FIG. 1;
FIG. 4 is a sectional view in an axial direction of the wiper ring of FIG. 3;
FIG. 5 is a front view of another wiper ring for the ball screw of the present invention;
FIG. 6 is a plan view of the wiper ring of FIG. 5; and
FIG. 7 represents a segment to be utilized for the wiper ring of FIG. 5 and includes FIG. 7A of a front view thereof and FIG. 7B of a plan view thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One preferred embodiment of the present invention will be described hereunder with reference to the accompanying drawings.
First, with reference to FIG. 1, a ball screw 10 generally comprises a screw shaft 11 , a number of balls 12 as rolling members and a nut (or nut member) 13 to be mounted to the screw shaft 11 through the balls 12 . The nut 13 has an inner peripheral surface portion to which a ball rolling groove 13 a is formed. The balls are rolled along a passage formed by a ball rolling groove 11 a of the screw shaft 11 and a ball rolling groove 13 a of the nut 13 in accordance with the relative rotation of the screw shaft 11 and the nut 13 . When the ball 12 reaches one end portion of the ball rolling groove 13 a , the ball 12 is returned to the opposite side portion of the ball rolling groove 13 a through a return tube 14 fixed to the nut 13 .
The nut is provided, at its both ends, with recessed portions 13 b , 13 b for mounting a wiper. Further, it is to be noted that, in the illustration of FIG. 1, although only the one end side of the nut 13 , the other end side has substantially the same structure as that of the illustrated side.
A wiper ring 20 is mounted to each of the recessed portions 13 b so as not to come off therefrom by means of stopper ring 15 . The purpose of mounting the wiper ring 20 is to prevent foreign material adhering to the screw shaft 11 from invading into the nut 13 and to prevent lubrication agent (lubricant) such as grease from leaking outside.
FIGS. 2 to 4 show detail structure or arrangement of such wiper ring 20 .
Each of the wiper rings 20 comprises a support ring 21 , a plurality of segments 22 A to 22 H (which, hereunder, may be generally as segment(s) 22 as shown in FIG. 1) disposed on one side of the support ring 21 , and a spring member (spring ring) 23 mounted to the outer peripheral portions of the segments 22 . The support ring 21 and the respective segments 22 will be produced through an injection molding of a synthetic resin material, for example.
The support ring 21 is formed in shape of plate having one peripheral portion at which a bias-cut 21 a is formed as shown in FIG. 2 . The support ring 21 is further formed, at its one side portion, with a shallow recessed portion 21 b having a bottom portion acting as a mounting surface of the segment 22 . Further, the spring ring 23 is formed by connecting both ends of a coil spring so as to provide a ring shape.
The support ring 21 has an inner peripheral surface 21 d which is formed to be equal to a contour shape on the axially perpendicular sectional surface of the outer periphery of the screw shaft 11 so as to be closely contacted to the screw shaft 11 . Further, in a case where the inner peripheral surface 21 d of the support ring 21 is formed to have an inclination so as to cross at an acute angle with respect to the mounting surface 21 a of the support ring 21 , the tightness of the support ring 21 to the screw shaft 11 will be enhanced. Moreover, in a case where the inner peripheral surface 21 d of the support ring 21 can be manufactured with high performance to thereby highly ensure the tightness to the screw shaft 11 , it may be not necessary to form the bias-cut 21 a mentioned before, and the support ring 21 may be formed in the endless ring shape.
The respective segments 22 ( 22 A to 22 H) are formed independently and assembled to be separable. The segment 22 has a rear (back) surface 22 a facing the support ring 21 , and a pin 22 b , as a support shaft member, is located to each of the segments 22 so as to extend towards the screw shaft 11 . Further, hole portions (holes) 21 e are also formed on the support ring 21 so as to penetrate the same at a portion corresponding to the location of the pin 22 b . It is, however, not always necessary to form the hole 21 b to penetrate the support ring 21 , and it is permitted for the hole 21 b to be opened to the mounting surface 21 c opposing to the segment 22 .
The respective segments 22 can be attached onto the mounting surface 21 c of the support ring 21 to be turnable about the pins 22 b by fitting the pins 22 b into the holes 21 e , respectively. According to such fitting, the respective segments 22 are arranged side by side along the peripheral direction of the support ring 21 with slits 24 between adjacent end faces 22 d and 22 e in the peripheral direction, and all the pins 22 b are interconnected respectively through the support ring 21 . Further, with reference to FIG. 2 or 3 , in order to scoop and then discharge foreign material in the ball rolling groove 11 a outside the nut 13 , the end faces 22 d and 22 e of the respective segments 22 mentioned above are obliquely inclined with respect to the radial and axial direction of the screw shaft, respectively. In the illustrated embodiment, although the slit 24 is described with a constant width, it may be formed so as to be widened on the outer peripheral side thereof.
Furthermore, each of the segments 22 is formed, at its inner peripheral surface 22 f , with a protrusion 22 g in form of string, as shown in FIG. 4, which is fitted to the ball rolling groove 11 a of the screw shaft 11 . Further, each of the segments 22 is formed, at its outer peripheral portion, with a groove 22 h along the circumferential direction thereof. When the segments 22 are assembled with the support ring 21 by fitting the pins 22 b of the respective segments 22 into the holes 21 e of the support ring, the outer peripheral grooves 22 h of the respective segments 22 become continuous to thereby provide one annular groove into which the spring ring 23 is fitted in an expanded state. According to the restoring force of the spring ring 23 , the respective segments 22 are pressed on the radially central side of the screw shaft 11 (i.e., the radially central side of the support ring 21 ). Thus, the inner peripheral portions 22 f of the respective segments 22 function as sealing means in close contact to the screw shaft 11 . Further, in order to prevent the segments 22 from coming off from the support ring 21 , it is desirable to form the pins 22 b by coming-off prevention means such as press-fitting method, calking method (i.e., a method in which the front end of the pin 22 b projecting over the hole 21 e is fused to be secured) or like method. However, it is necessary to fit the pin 22 b to be rotatable (turnable) into the hole 21 e.
The protrusion 22 g in shape of string is twisted in a spiral shape along the ball rolling groove 11 a of the screw shaft 11 , and the shape thereof may differ in accordance with the attachment positions of the segments 22 A to 22 H. Accordingly, the respective segments 22 A to 22 h have different shapes from each other in their inner peripheral portions 22 f . Thus, it is difficult to produce the respective segments by one common mold. On the other hand, since the protrusions 22 g are fitted into the one continuous ball rolling groove 11 a , it is required for the protrusions 22 g of the respective segments 22 to be continuous to describe one spiral string along the ball rolling groove 11 a . In order to satisfy such requirement, it would be necessary to form cavities corresponding to the respective segments 22 A to 22 H in one set of mold halves to thereby form the segments at once. In such method, it is possible to prescribe, by the mold, the dimensional performance of the respective segments 22 A to 22 H and the relative positional relationship therebetween, so that the respective segments 22 A to 22 H can be produced more precisely in comparison with the case that the respective segments are produced independently. Moreover, in the integral structure of the support ring 21 and the segments 22 , the shape of the mold is made complicated so as to withdraw a core forming the spirally twisted protrusions 22 g . However, in the case of the present embodiment in which the respective segments 22 A to 22 H are formed integrally from each other, since the respective segments are not restricted or affected from each other, so that it is possible to easily withdraw the core forming the inner peripheral portions of the segments 22 , thus simplifying the structure of the mold.
The wiper ring 20 thus formed is set to the recessed portion 13 b of the nut 13 so as to be directed inside the axial direction of the nut. In the state that the wiper ring 20 is mounted onto the screw shaft 11 , even if the support ring 21 is deformed to widen the bias-cut 21 a , the segments 22 receiving the force of the spring ring 23 are rotated in a manner that the inner peripheral portions 22 f of the respective segments 22 are rotated about the pins 22 b so as to be closely contacted to the screw shaft 11 . As a result, the respective segments 22 are equally and tightly contacted to the screw shaft 11 , and hence, the sealing performance of the wiper ring 20 can be achieved.
FIGS. 5 to 7 represent another embodiment of the wiper ring according to the present invention.
With reference to FIGS. 5 to 7 , a wiper ring 30 of this embodiment is provided with a plurality of segments 31 ( 31 A to 31 H, eight, in the illustration) and a spring ring 32 , which is identical structure to that of the wiper ring 20 of the former embodiment. However, in this embodiment, any support ring, such as that 21 in the former embodiment, is not provided, and in substitution therefor, the segment 31 is formed with a segment body 33 and a support plate 34 . The respective segments 31 A to 31 H are formed independently as separate members to thus be separable, and the segment body 33 and the support plate 34 in each segment 31 are formed of resin material integrally with each other.
The segment body 33 is not provided with a support shaft member such as pin 22 b for the segment 22 in the former embodiment, and instead, holes 33 b are formed. Except for this structure, the segment 33 has substantially identical shape or structure as that of the segment 22 . Accordingly, constitutional elements of the segment 33 of this embodiment corresponding to the elements 22 a and 22 c to 22 h of the segment 22 in the former embodiment are added only with reference numerals 33 a , 33 c to 33 h , respectively, and the descriptions or explanations thereof are omitted herein.
Furthermore, as like in the former embodiment, it is preferred to form the respective segments 33 A to 33 H at once by one set of mold halves because of the same reason as that mentioned before with respect to the wiper ring 20 .
The support plate 34 serves like the support ring 21 of the wiper ring 20 in the former embodiment, and the support plates 34 are shifted in their phases in the peripheral direction with respect to the segment bodies 33 and formed, on their surfaces, with pins 34 a as support shafts, to be fitted to the holes 33 b formed on the segment bodies 33 . However, any one of the segments (for example, segment 31 G) is not provided with such pin 34 a , and in this connection, the hole 33 b of the segment 31 H adjacent to this segment 31 G may be eliminated.
The segments 31 A to 31 H thus constructed are arranged side by side so as to describe a circle and then connected together by fitting each of the pins 34 a into the hole 33 b of each of the adjacent segments. Thereafter, the spring ring 32 is fitted into the grooves 33 h formed on the outer periphery of the segment bodies 33 to thereby complete the wiper ring 30 of this embodiment. In such wiper ring 30 , slits 35 , like the slits 24 of the wiper ring 20 of the former embodiment shown in FIG. 2, are formed between the respective bodies 33 of the connected segments 31 A to 31 H. Further, the support plates 34 of the respective segments 31 are arranged to be continuous in their peripheral direction and, accordingly, a ring-shaped plate like the support ring 21 of the wiper ring 20 is formed. However, as mentioned above, as the segment 31 G is not provided with the pin 34 a , the segments 31 H and 31 G are not connected. According to the described structure, the wiper ring 30 is also formed with a cutout portion (separated portion) identical to the bias-cut 21 a of the wiper ring 20 of FIG. 2 . Further, it is desired that the connection between the pin 34 a and the hole 33 b of the segment 31 by coming-off prevention methods such as press-fitting method or calking method carried out with reference to the connection between the pin 22 b and the hole 21 e of the wiper ring 20 . In such method, however, it is necessary for the pin 34 a to be fitted to the hole 33 b in the rotatable manner.
Furthermore, in the wiper ring 30 of this embodiment, the support plate 34 is also mounted to the recessed portion 13 b of the nut so as to be directed axially inward of the nut 13 . The mounting of the wiper ring 30 onto the screw shaft 11 permits to rotate the inner peripheral portions 33 f of the respective segment bodies 33 about the pins 34 a so as to be closely contacted to the screw shaft 11 while the respective segments 31 receiving the force of the spring ring 32 even if the wiper ring 30 so deformed as that the non-connected segments 31 G and 31 H are relatively separated from each other in the circumferential direction. As a result, the respective segments 31 can be equally and well contacted to the screw shaft 11 , and hence, the sealing performance due to the wiper ring 30 can be achieved.
Further, it is to be noted that the present invention is not limited to the described embodiments and many other changes and modifications may be made without departing from the scopes of the appended claims.
For example, with the wiper ring 20 of FIG. 2, the pin 22 b may be provided for the support ring 21 and, on the other hand, the hole 21 e may be formed on the segment 22 . With the wiper ring 30 , also, the arrangement of the hole 32 b and the pin 34 a may be substituted with each other. Furthermore, the lengths in the circumferential directions of the respective segments 22 A to 22 H and 31 A to 31 H may be made equal to each other or different from each other, and the number of the segments 22 and 31 is not limited to eight (8).
The present application claims priority under 35 U.S.C § 119 to Japanese Patent Application No. 2000-358245 filed Nov. 24, 2000 entitled “WIPER RING AND BALL SCREW PROVIDED WITH WIPER RING”. The contents of that application are incorporated herein by reference in their entirety. | A wiper ring to be applied to a nut of a ball screw having a screw shaft comprises a plurality of segments each constituted as independent element having a seal portion to be contacted to the screw shaft, support pins extending in an axial direction of the screw shaft so as to correspond to the segments, respectively, the segments being arranged in a circumferential direction of the screw shaft to be rotatable about the pins, the pins being connected to each other through support members so as to limit the relative movement of the respective pins, and a spring member for urging the segments arranged circumferential direction of the screw shaft so as to be directed towards radially central side of the screw shaft. | 5 |
BACKGROUND OF THE INVENTION
Machine tools utilizing rotating and stationary tools require periodic tool adjustment to compensate for tool wear, tool mounting variations, wear in slides, compounds and holders, etc. Minute tool adjustment is difficult to consistently achieve, and shims and manual tool anchoring bolts and the like are often utilized to produce micro tool positioning; however, such manual adjustment means are haphazard and time consuming.
It is an object of the invention to provide a machine tool adjustment capable of producing minute tool positioning rapidly, consistently and accurately.
Another object of the invention is to provide minute tool adjustment within machine tools wherein tool positioning is controlled by an electric stepping motor capable of accurate and reversible control.
Yet an additional object of the invention is to provide minute tool adjustment means capable of being incorporated into rotating boring tools and the like wherein limited space and clearance is available.
A further object of the invention is to provide a minute tool adjustment for machine tools wherein the adjustment mechanism may be incorporated within existing tool configurations, and does not require major modification of machine tool designs.
In the practice of the invention a rotatable support includes a tool carrier mounted thereon whereby rotation of the support rotates the carrier and tool. For instance, the tool may constitute a boring tool and the carrier may be of an elongated configuration for insertion into the bore of a workpiece.
A shaft concentric with the support and carrier axis is rotatable by accurately controlled drive means, such as a reversible electric stepping motor, and an eccentric connection exists between the shaft and the tool carrier. Thus, rotation of the shaft causes a lateral force to be imposed upon the tool carrier with respect to the axis of support and carrier rotation, and this force laterally deflects the tool to provide compensation for tool wear or minor dimensional tool adjustment.
In one embodiment of the invention, the outer end of the elongated tool carrier includes a cap upon which the cutting tool is mounted. The shaft extends through the carrier and includes an eccentric portion associated with the cap through a ball bearing. The shaft is supported relative to the carrier adjacent the eccentric portion by another ball bearing wherein rotation of the shaft imposes a lateral deforming force on the cap due to the eccentric portion, and this lateral force is sufficient to slightly deflect the cap to achieve the desired tool displacement.
In another embodiment of the invention, the tool carrier is in the form of an elongated lever having a free end upon which the cutting tool is mounted. The inner end of the tool carrier lever is connected to the indexable shaft by an eccentric connection whereby rotation of the shaft causes the carrier lever to pivot about a universal pivot producing a lateral deflection at the tool carrier outer end displacing the tool as desired.
The degree of eccentricity of the eccentric portions on the shaft are small wherein only minute tool movements are produced, and the energy required to produce such movement is relatively small. The practice of the invention permits very accurate tool adjustments to be made under close control.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:
FIG. 1 is an elevational view, partially diametrically sectioned, of apparatus embodying the invention,
FIG. 2 is an elevational, sectional view taken along Section II--II of FIG. 1, and
FIG. 3 is an elevational, diametrically sectioned view of apparatus embodying another form of the inventive concept.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the embodiment of FIG. 1, a spindle 10 of a machine tool, such as a boring machine, is illustrated, and this spindle includes components rotatably mounted upon the machine tool frame, not shown, by conventional bearings, not shown. The spindle 10 includes a body 12 adapted to be rotated by a motor-driven belt received within belt groove 14, and the body includes a rear cover 16 held in position by tension bolts 18 and nuts 20. An electric stepping motor 22 is attached to the cover 16 by neck 24, and the stepping motor 22 may be the type manufactured by Compumotor Corporation, Petaluma, Calif., Model M83-93. The stepping motor includes a driveshaft 26 extending through the open center of the body 12 in driving connection through coupling 30 with the shaft 28 extending into the support 32. The support 32 is mounted upon the body 12 by neck 34 for rotation with the body, and the shaft 28 extends into the support chamber 36.
The elongated tool carrier 38 is mounted upon the support 32 by bolts, and the outer end of the carrier is provided with a cap 40 threaded upon the carrier outer end by threads 42. A conventional cutting tool 44 is attached to the cap 40 by known tool holder structure, and the tool 44 may be of the known three-sided carbide-tipped type. It is to be noted that the location of the tool is axially beyond the threads 42.
A shaft 46 is supported within the carrier 38 upon double ball bearings 48 and 50, and the shaft 46 is in driven relationship to the shaft 28 by coupling 52. Bearing retention is achieved by threaded collar 54 engaging the annular bearing retainer 56.
The shaft 46 includes a cylindrical portion 58 having a center eccentrically offset a few thousandths of an inch from the center of the shaft 46 wherein the portion 58 constitutes an eccentric portion relative to the axis of shaft 46. The portion 58 receives anti-friction ball bearing 60 which is pressed into the cap 40, and the bearing is maintained upon the eccentric portion 58 by washer 62 and screw 64.
It is to be appreciated that the double ball bearing 50 is of such axial length and position as to be in axial alignment with both the carrier 38 and the cap 40 and is closely received within cylindrical recesses 66 and 68 located within the carrier and cap, respectively.
Rotation of the shafts 26, 28 and 46 by actuation of the stepping motor 22 rotates the eccentric portion 58 and such rotation of the eccentric portion produces a lateral displacement of the tool 44 relative to the axis of the shaft 46 and carrier 38 due to deformation occurring within the cap 40. Such cap deformation is limited, only a few thousandths of an inch, but this is the extent of adjustment desired.
Due to the resistance of such lateral deformation by the cap 40, the tool 46 will be firmly supported in a vibration-resisting manner regardless of the adjustment of the tool, and it will be appreciated that as the shafts 26, 28 and 46 are all located within the normal configuration of the spindle body 12, support 32 and carrier 38, that the practice of the invention permits very accurate tool adjustments to be made without increasing the dimensions of the carrier and tool support.
In the embodiment of FIG. 3, a tool spindle is shown at 70, and the tool spindle is mounted upon machine tool apparatus, not shown, which is rotatably driven in the usual manner. The spindle body 72 attaches to the rotating machine tool components by a plurality of screws 74, and the body is internally concentrically bored to closely receive the double ball bearing 78 for supporting the shaft 76. The shaft 76 is supported at its left end, FIG. 3, by anti-friction ball bearing 79, and is in driven engagement with the shaft 80 through coupling 82. The shaft 80 attaches to a reversible electric stepping motor generally indicated at 84, similar to the motor 22 of the previously described embodiment.
A pivot cradle 86 is mounted upon the spindle body 72 by a plurality of bolts 88, and the cradle includes a cavity 90 defined by obliquely oriented surface 92 and oblique surface 94 defined in threaded cap 96. The pivot cradle includes a key pin 98, and the threaded cap 96 provides access to the cradle cavity permitting the carrier lever 100 to be inserted therein, as described below.
A carrier lever 100 is of an elongated configuration having an outerend 102 upon which the cutting tool 104 is mounted by conventional cutting holding means. Tool 104 may be of the carbide-insert type as commonly used for boring operations.
The inner end of the carrier lever 100 is formed with a cylindrical stud 106 concentric with the axis of the lever 100, and an anti-friction ball bearing 108 is mounted upon the stud and is pressed into the bore 110 defined within the cavity of the hollow shaft 76. The cylindrical bore 110 is eccentrically oriented with respect to the axis of rotation of the shaft 76 whereby rotation of the shaft 76 will produce lateral deflection of the stud 106 relative to the axis of the shaft 76, and the axis of the pivot cradle 86.
The tool carrier lever 100 includes a spherical segment 112 located between the inner and outer lever ends for engagement by the oblique surfaces 92 and 94 of the pivot cavity. Also, the spherical segment 112 is provided with an axial slot 114 for receiving the key pin 98 which prevents rotation of the carrier lever within the pivot cavity.
When lateral adjustment of the tool 104 is desired, the shaft 76 is rotated by the stepping motor 84, and the eccentric orientation of the bore 110 will cause a lateral displacement of the inner end of the carrier lever which results in a greater lateral displacement of the tool 104 due to the difference in lever arm dimensions between the inner end stud 106 and the pivot segment center as represented at A, and the distance between the tool 104 and the pivot center A.
The embodiment of the invention shown in FIG. 3 permits a carrier lever of relatively small cross sectional dimension to be employed, and yet minute tool adjustments can be achieved with little power requirement.
It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention. | The invention pertains to a fine adjustment for the tool of a machine tool. The tool carrier is displaceable by forces generated by the rotation of a shaft through an eccentric wherein the shaft is indexed by a reversible electric stepping motor. Tool adjustments of thousandths of an inch are accurately and consistently achievable. | 8 |
SEQUENCE LISTING
The present application is being filed along with a Sequence Listing in electronic format. The Sequence Listing is provided as a file entitled BIOL0216USL2SEQ.txt created Mar. 12, 2013, which is 124 kb in size. The information in the electronic format of the sequence listing is incorporated herein by reference in its entirety.
FIELD
In certain embodiments, methods, compounds, and compositions for treating B-cell lymphoma by inhibiting expression of STAT3 mRNA or protein in an animal are provided herein. Such methods, compounds, and compositions are useful to treat, prevent, or ameliorate B-cell lymphoma or hepatocellular carcinoma.
BACKGROUND
The STAT (signal transducers and activators of transcription) family of proteins are DNA-binding proteins that play a dual role in signal transduction and activation of transcription. Presently, there are six distinct members of the STAT family (STAT1, STAT2, STAT3, STAT4, STAT5, and STATE) and several isoforms (STAT1α, STAT1β, STAT3α and STAT3β). The activities of the STATs are modulated by various cytokines and mitogenic stimuli. Binding of a cytokine to its receptor results in the activation of Janus protein tyrosine kinases (JAKs) associated with these receptors. This phosphorylates STAT, resulting in translocation to the nucleus and transcriptional activation of STAT responsive genes. Phosphorylation on a specific tyrosine residue on the STATs results in their activation, resulting in the formation of homodimers and/or heterodimers of STAT which bind to specific gene promoter sequences. Events mediated by cytokines through STAT activation include cell proliferation and differentiation and prevention of apoptosis.
The specificity of STAT activation is due to specific cytokines, i.e., each STAT is responsive to a small number of specific cytokines. Other non-cytokine signaling molecules, such as growth factors, have also been found to activate STATs. Binding of these factors to a cell surface receptor associated with protein tyrosine kinase also results in phosphorylation of STAT.
STAT3 (also acute phase response factor (APRF)), in particular, has been found to be responsive to interleukin-6 (IL-6) as well as epidermal growth factor (EGF) (Darnell, Jr., J. E., et al., Science, 1994, 264, 1415-1421). In addition, STAT3 has been found to have an important role in signal transduction by interferons (Yang, C.-H., et al., Proc. Natl. Acad. Sci. USA, 1998, 95, 5568-5572). Evidence exists suggesting that STAT3 may be regulated by the MAPK pathway. ERK2 induces serine phosphorylation and also associates with STAT3 (Jain, N., et al., Oncogene, 1998, 17, 3157-3167).
STAT3 is expressed in most cell types (Zhong, Z., et al., Proc. Natl. Acad. Sci. USA, 1994, 91, 4806-4810). It induces the expression of genes involved in response to tissue injury and inflammation. STAT3 has also been shown to prevent apoptosis through the expression of bcl-2 (Fukada, T., et al., Immunity, 1996, 5, 449-460).
Recently, STAT3 was detected in the mitochondria of transformed cells, and was shown to facilitate glycolytic and oxidative phosphorylation activities similar to that of cancer cells (Gough, D. J., et al., Science, 2009, 324, 1713-1716). The inhibition of STAT3 in the mitochondria impaired malignant transformation by activated Ras. The data confirms a Ras-mediated transformation function for STAT3 in the mitochondria in addition to its nuclear roles.
Aberrant expression of or constitutive expression of STAT3 is associated with a number of disease processes.
SUMMARY
B-cell lymphoma is a B-lymphocyte blood cell cancer that is clinically classified as either Hodgkin's lymphoma or non-Hodgkin's lymphoma. There are several types of non-Hodgkin's lymphoma, of which diffuse large B-cell lymphoma (DLBCL) is the most common type, accounting for approximately 30 percent of all lymphomas. In the United States, DLBCL affects about 7 out of 100,000 people each year.
Several embodiments provided herein relate to the discovery that inhibiting the JAK-STAT signaling pathway can be useful for treating B-cell lymphoma. In certain embodiments, antisense compounds targeting STAT3 are useful for treating B-cell lymphoma, such as DLBCL, at unexpectedly low doses for an antisense compound as a cancer therapeutic. In several embodiments, antisense compounds targeting STAT3 provided herein are administered to a subject having B-cell lymphoma at a fixed total weekly dose in the range of about 15-750 mg. In certain embodiments, antisense compounds targeting STAT3 provided herein are administered to a subject having B-cell lymphoma in the range of about 0.2 to 3.5 milligrams of the antisense compound per kilogram of the subject's body weight per week (0.2-3.5 mg/kg/wk). Such dose ranges are unexpectedly low for treating cancer. By comparison, a Phase 1 study of LY2275796, an antisense oligonucleotide targeted to cap-binding protein eukaryotic initiation factor 4E (eIF-4E), concluded that the maximum tolerable dose (MTD) and biologically effective dose (BED) of LY2275796 is 1,000 mg under a loading and maintenance dose regimen, but even at a 1,000 mg dose, no tumor response was observed. (Hong D. S. et al., Clin Cancer Res. 2011 17(20):6582-91).
DETAILED DESCRIPTION
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. Herein, the use of the singular includes the plural unless specifically stated otherwise. As used herein, the use of the term “or” means “and/or”, unless stated otherwise. Furthermore, the use of the term “including” as well as other forms, such as “includes” and “included”, is not limiting. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one subunit, unless specifically stated otherwise.
The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application, including, but not limited to, patents, patent applications, articles, books, and treatises, are hereby expressly incorporated by reference for the portions of the document discussed herein, as well as in their entirety.
Definitions
Unless specific definitions are provided, the nomenclature utilized in connection with, and the procedures and techniques of, analytical chemistry, synthetic organic chemistry, and medicinal and pharmaceutical chemistry described herein are those well known and commonly used in the art. Standard techniques may be used for chemical synthesis, and chemical analysis. Where permitted, all patents, applications, published applications and other publications, GENBANK Accession Numbers and associated sequence information obtainable through databases such as National Center for Biotechnology Information (NCBI) and other data referred to throughout in the disclosure herein are incorporated by reference for the portions of the document discussed herein, as well as in their entirety.
Unless otherwise indicated, the following terms have the following meanings:
“2′-deoxynucleoside” means a nucleoside comprising 2′-H furanosyl sugar moiety, as found naturally occurring in deoxyribonucleosides (DNA). In certain embodiments, a 2′-deoxynucleoside may comprise a modified nucleobase or may comprise an RNA nucleobase (e.g., uracil).
“2′-O-methoxyethyl” (also 2′-MOE and 2′-O(CH 2 ) 2 —OCH 3 ) refers to an O-methoxy-ethyl modification of the 2′ position of a furosyl ring. A 2′-O-methoxyethyl modified sugar is a modified sugar.
“2′-MOE nucleoside” (also 2′-O-methoxyethyl nucleoside) means a nucleoside comprising a 2′-MOE modified sugar moiety.
“2′-substituted nucleoside” means a nucleoside comprising a substituent at the 2′-position other than H or OH. Unless otherwise indicated, a 2′-substituted nucleoside is not a bicyclic nucleoside.
“5′-methylcytosine” means a cytosine modified with a methyl group attached to the 5′ position. A 5-methylcytosine is a modified nucleobase.
“About” as applied to dosing amounts means within +12% of a value. For example, if it is stated, “the dose is an amount in the range of about 15-750 mg,” it is implied that the dose is an amount in the range of 13-840 mg. In another example, if it is stated that the dose is an amount of “about 50 mg,” it is implied that the dose can be from 44 mg to 56 mg. “About” as applied to activity levels means within +10% of a value. For example, if it is stated, “the compounds affected at least about 70% inhibition of STAT3”, it is implied that the STAT3 levels are inhibited within a range of 63% and 77%.
“Active pharmaceutical agent” means the substance or substances in a pharmaceutical composition that provide a therapeutic benefit when administered to an individual. For example, in certain embodiments an antisense oligonucleotide targeted to STAT3 is an active pharmaceutical agent.
“Active target region” or “target region” means a region to which one or more active antisense compounds is targeted. “Active antisense compounds” means antisense compounds that reduce target nucleic acid levels or protein levels.
“Administered concomitantly” refers to the co-administration of two agents in any manner in which the pharmacological effects of both are manifest in the patient at the same time. Concomitant administration does not require that both agents be administered in a single pharmaceutical composition, in the same dosage form, or by the same route of administration. The effects of both agents need not manifest themselves at the same time. The effects need only be overlapping for a period of time and need not be coextensive.
“Administering” means providing a pharmaceutical agent to an individual, and includes, but is not limited to administering by a medical professional and self-administering.
“Amelioration” refers to a lessening of at least one indicator, sign, or symptom of an associated disease, disorder, or condition. The severity of indicators may be determined by subjective or objective measures, which are known to those skilled in the art.
“Animal” refers to a human or non-human animal, including, but not limited to, mice, rats, rabbits, dogs, cats, pigs, and non-human primates, including, but not limited to, monkeys and chimpanzees.
“Antisense activity” means any detectable or measurable activity attributable to the hybridization of an antisense compound to its target nucleic acid. In certain embodiments, antisense activity is a decrease in the amount or expression of a target nucleic acid or protein encoded by such target nucleic acid.
“Antisense compound” means an oligomeric compound that is capable of undergoing hybridization to a target nucleic acid through hydrogen bonding. Examples of antisense compounds include single-stranded and double-stranded compounds, such as, antisense oligonucleotides, siRNAs, and shRNAs.
“Antisense inhibition” means reduction of target nucleic acid levels or target protein levels in the presence of an antisense compound complementary to a target nucleic acid as compared to target nucleic acid levels or target protein levels in the absence of the antisense compound.
“Antisense oligonucleotide” means a single-stranded oligonucleotide having a nucleobase sequence that permits hybridization to a corresponding region or segment of a target nucleic acid.
“Bicyclic sugar” means a furosyl ring modified by the bridging of two atoms. A bicyclic sugar is a modified sugar.
“Bicyclic nucleoside” (also BNA) means a nucleoside having a sugar moiety comprising a bridge connecting two carbon atoms of the sugar ring, thereby forming a bicyclic ring system. In certain embodiments, the bridge connects the 4′-carbon and the 2′-carbon of the sugar ring.
“Cap structure” or “terminal cap moiety” means chemical modifications, which have been incorporated at either terminus of an antisense compound.
“cEt” or “constrained ethyl” means a bicyclic nucleoside having a sugar moiety comprising a bridge connecting the 4′-carbon and the 2′-carbon, wherein the bridge has the formula: 4′-CH(CH 3 )—O-2′.
“Constrained ethyl nucleoside” (also cEt nucleoside) means a nucleoside comprising a bicyclic sugar moiety comprising a 4′-CH(CH 3 )—O-2′ bridge.
“Chemically distinct region” refers to a region of an antisense compound that is in some way chemically different than another region of the same antisense compound. For example, a region having 2′-O-methoxyethyl nucleotides is chemically distinct from a region having nucleotides without 2′-O-methoxyethyl modifications.
“Chimeric antisense compound” means an antisense compound that has at least two chemically distinct regions.
“Co-administration” means administration of two or more pharmaceutical agents to an individual. The two or more pharmaceutical agents may be in a single pharmaceutical composition, or may be in separate pharmaceutical compositions. Each of the two or more pharmaceutical agents may be administered through the same or different routes of administration. Co-administration encompasses parallel or sequential administration.
“Complementarity” means the capacity for pairing between nucleobases of a first nucleic acid and a second nucleic acid.
“Contiguous nucleobases” means nucleobases immediately adjacent to each other.
“Diluent” means an ingredient in a composition that lacks pharmacological activity, but is pharmaceutically necessary or desirable. For example, the diluent in an injected composition may be a liquid, e.g. saline solution.
“Dose” means a specified quantity of a pharmaceutical agent provided in a single administration, or in a specified time period. In certain embodiments, a dose may be administered in one, two, or more boluses, tablets, or injections. For example, in certain embodiments where subcutaneous administration is desired, the desired dose requires a volume not easily accommodated by a single injection, therefore, two or more injections may be used to achieve the desired dose. In certain embodiments, the pharmaceutical agent is administered by infusion over an extended period of time or continuously. Doses may be stated as the amount of pharmaceutical agent per hour, day, week, or month. In certain embodiments, single dose means administration of one dose, and only one dose, to a subject.
“Dosage unit” means a form in which a pharmaceutical agent is provided. In certain embodiments, a dosage unit is a vial containing lyophilized ISIS 481464. In certain embodiments, a dosage unit is a vial containing reconstituted ISIS 481464.
“Dosing regimen” is a combination of doses designed to achieve one or more desired effects. In certain embodiments, a dose regimen is designed to provide a therapeutic effect quickly.
“Duration” means the period of time during which an activity or event continues. For example, the duration of a loading phase is the period of time during which loading doses are administered. For example, the duration of the maintenance phase is the period of time during which maintenance doses are administered.
“Effective amount” means the amount of active pharmaceutical agent sufficient to effectuate a desired physiological outcome in an individual in need of the agent. The effective amount may vary among individuals depending on the health and physical condition of the individual to be treated, the taxonomic group of the individuals to be treated, the formulation of the composition, assessment of the individual's medical condition, and other relevant factors.
“First phase” means a dosing phase during which administration is initiated and steady state concentrations of pharmaceutical agents can be, but is not necessarily, achieved in a target tissue. “Second phase” means a dosing phase after the “first phase.” In certain embodiments, the dose or total weekly dose of the first phase and the second phase are different.
“Fully complementary” or “100% complementary” means each nucleobase of a first nucleic acid has a complementary nucleobase in a second nucleic acid. In certain embodiments, a first nucleic acid is an antisense compound and a target nucleic acid is a second nucleic acid.
“Gapmer” means a chimeric antisense compound in which an internal region having a plurality of nucleosides that support RNase H cleavage is positioned between external regions having one or more nucleosides, wherein the nucleosides comprising the internal region are chemically distinct from the nucleoside or nucleosides comprising the external regions. The internal region may be referred to as the “gap” and the external regions may be referred to as the “wings.”
“Gap-widened” means a chimeric antisense compound having a gap segment of 12 or more contiguous 2′-deoxyribonucleosides positioned between and immediately adjacent to 5′ and 3′ wing segments having from one to six nucleosides.
“HCC” means hepatocellular carcinoma. It is the most common form of liver cancer and also referred to as malignant hepatoma.
“Hybridization” means the annealing of complementary nucleic acid molecules. In certain embodiments, complementary nucleic acid molecules include an antisense compound and a target nucleic acid.
“Hyperproliferative disease” means a disease characterized by rapid or excessive growth and reproduction of cells. Examples of hyperproliferative diseases include cancer, e.g., carcinomas, sarcomas, lymphomas, and leukemias as well as associated malignancies and metastases.
“Identifying an animal at risk for hyperproliferative disease” means identifying an animal having been diagnosed with a hyperproliferative disease or identifying an animal predisposed to develop a hyperproliferative disease. Individuals predisposed to develop a hyperproliferative disease include those having one or more risk factors for hyperproliferative disease including older age; history of other hyperproliferative diseases; history of tobacco use; history of exposure to sunlight and/or ionizing radiation; prior contact with certain chemicals, especially continuous contact; past or current infection with certain viruses and bacteria; prior or current use of certain hormone therapies; genetic predisposition; alcohol use; and certain lifestyle choices including poor diet, lack of physical activity, and/or being overweight. Such identification may be accomplished by any method including evaluating an individual's medical history and standard clinical tests or assessments.
“Immediately adjacent” means there are no intervening elements between the immediately adjacent elements.
“Inhibiting STAT3” means reducing expression of STAT3 mRNA and/or protein levels in the presence of a STAT3 antisense compound, including a STAT3 antisense oligonucleotide, as compared to expression of STAT3 mRNA and/or protein levels in the absence of a STAT3 antisense compound, such as an antisense oligonucleotide.
“Individual” means a human or non-human animal selected for treatment or therapy.
“Internucleoside linkage” refers to the chemical bond between nucleosides.
“ISIS 481464” means a STAT3 antisense oligonucleotide having the nucleobase sequence “CTATTTGGATGTCAGC”, incorporated herein as SEQ ID NO: 12, where each internucleoside linkage is a phosphorothioate internucleoside linkage, each cytosine is a 5-methylcytosine, and each of nucleosides 1-3 and 14-16 comprise a cEt moeity. ISIS 481464 is complementary to nucleobases 3016-3031 of the sequence of GENBANK Accession No. NM_139276.2, incorporated herein as SEQ ID NO:1.
“Linked nucleosides” means adjacent nucleosides which are bonded together.
“Loading phase” means a dosing phase during which administration is initiated and steady state concentrations of pharmaceutical agents are achieved in a target tissue. For example, a loading phase is a dosing phase during which steady state concentrations of antisense oligonucleotide are achieved in liver.
“Maintenance phase” means a dosing phase after target tissue steady state concentrations of pharmaceutical agents have been achieved. For example, a maintenance phase is a dosing phase after which steady state concentrations of antisense oligonucleotide are achieved in liver.
“Mismatch” or “non-complementary nucleobase” refers to the case when a nucleobase of a first nucleic acid is not capable of pairing with the corresponding nucleobase of a second or target nucleic acid.
“Modified internucleoside linkage” refers to a substitution or any change from a naturally occurring internucleoside bond (i.e. a phosphodiester internucleoside bond).
“Modified nucleobase” refers to any nucleobase other than adenine, cytosine, guanine, thymidine, or uracil. An “unmodified nucleobase” means the purine bases adenine (A) and guanine (G), and the pyrimidine bases thymine (T), cytosine (C), and uracil (U).
“Modified nucleotide” means a nucleotide having, independently, a modified sugar moiety, modified internucleoside linkage, or modified nucleobase. A “modified nucleoside” means a nucleoside having, independently, a modified sugar moiety or modified nucleobase.
“Modified oligonucleotide” means an oligonucleotide comprising a modified internucleoside linkage, a modified sugar, and/or a modified nucleobase.
“Modified sugar” refers to a substitution or change from a natural sugar.
“Motif” means the pattern of chemically distinct regions in an antisense compound.
“Naturally occurring internucleoside linkage” means a 3′ to 5′ phosphodiester linkage.
“Natural sugar moiety” means a sugar found in DNA (2′-H) or RNA (2′-OH).
“Nucleic acid” refers to molecules composed of monomeric nucleotides. A nucleic acid includes ribonucleic acids (RNA), deoxyribonucleic acids (DNA), single-stranded nucleic acids, double-stranded nucleic acids, small interfering ribonucleic acids (siRNA), and microRNAs (miRNA).
“Nucleobase” means a heterocyclic moiety capable of pairing with a base of another nucleic acid.
“Nucleobase sequence” means the order of contiguous nucleobases independent of any sugar, linkage, or nucleobase modification.
“Nucleoside” means a nucleobase linked to a sugar.
“Nucleoside mimetic” includes those structures used to replace the sugar or the sugar and the base and not necessarily the linkage at one or more positions of an oligomeric compound such as for example nucleoside mimetics having morpholino, cyclohexenyl, cyclohexyl, tetrahydropyranyl, bicyclo or tricyclo sugar mimetics, e.g., non furanose sugar units. Nucleotide mimetic includes those structures used to replace the nucleoside and the linkage at one or more positions of an oligomeric compound such as for example peptide nucleic acids or morpholinos (morpholinos linked by —N(H)—C(═O)—O— or other non-phosphodiester linkage). Sugar surrogate overlaps with the slightly broader term nucleoside mimetic but is intended to indicate replacement of the sugar unit (furanose ring) only. The tetrahydropyranyl rings provided herein are illustrative of an example of a sugar surrogate wherein the furanose sugar group has been replaced with a tetrahydropyranyl ring system.
“Nucleotide” means a nucleoside having a phosphate group covalently linked to the sugar portion of the nucleoside.
“Off-target effect” refers to an unwanted or deleterious biological effect associated with modulation of RNA or protein expression of a gene other than the intended target nucleic acid.
“Oligomeric compound” or “oligomer” means a polymer of linked monomeric subunits which is capable of hybridizing to at least a region of a nucleic acid molecule.
“Oligonucleotide” means a polymer of linked nucleosides each of which can be modified or unmodified, independent one from another.
“Parenteral administration” means administration through injection (e.g., bolus injection) or infusion. Parenteral administration includes subcutaneous administration, intravenous administration, intramuscular administration, intraarterial administration, intraperitoneal administration, or intracranial administration, e.g., intrathecal or intracerebroventricular administration.
“Peptide” means a molecule formed by linking at least two amino acids by amide bonds. Peptide refers to polypeptides and proteins.
“Pharmaceutical composition” means a mixture of substances suitable for administering to an individual. For example, a pharmaceutical composition may comprise one or more active pharmaceutical agents and a sterile aqueous solution. In certain embodiments, a pharmaceutical composition shows activity in free uptake assay in certain cell lines.
“Pharmaceutically acceptable derivative” encompasses pharmaceutically acceptable salts, conjugates, prodrugs or isomers of the compounds described herein.
“Pharmaceutically acceptable salts” means physiologically and pharmaceutically acceptable salts of antisense compounds, i.e., salts that retain the desired biological activity of the parent oligonucleotide and do not impart undesired toxicological effects thereto.
“Phosphorothioate linkage” means a linkage between nucleosides where the phosphodiester bond is modified by replacing one of the non-bridging oxygen atoms with a sulfur atom. A phosphorothioate linkage (P═S) is a modified internucleoside linkage.
“Portion” means a defined number of contiguous (i.e., linked) nucleobases of a nucleic acid. In certain embodiments, a portion is a defined number of contiguous nucleobases of a target nucleic acid. In certain embodiments, a portion is a defined number of contiguous nucleobases of an antisense compound.
“Prevent” refers to delaying or forestalling the onset or development of a disease, disorder, or condition for a period of time from minutes to indefinitely. Prevent also means reducing risk of developing a disease, disorder, or condition.
“Prodrug” means a therapeutic agent that is prepared in an inactive form that is converted to an active form within the body or cells thereof by the action of endogenous enzymes or other chemicals or conditions.
“Side effects” means physiological responses attributable to a treatment other than the desired effects. In certain embodiments, side effects include injection site reactions, liver function test abnormalities, renal function abnormalities, liver toxicity, renal toxicity, central nervous system abnormalities, myopathies, and malaise. For example, increased aminotransferase levels in serum may indicate liver toxicity or liver function abnormality. For example, increased bilirubin may indicate liver toxicity or liver function abnormality.
“Signal Transducer and Activator of Transcription 3 nucleic acid” or “STAT3 nucleic acid” means any nucleic acid encoding STAT3. For example, in certain embodiments, a STAT3 nucleic acid includes a DNA sequence encoding STAT3, an RNA sequence transcribed from DNA encoding STAT3 (including genomic DNA comprising introns and exons), and an mRNA sequence encoding STAT3. “STAT3 mRNA” means an mRNA encoding a STAT3 protein.
“Single-stranded oligonucleotide” means an oligonucleotide which is not hybridized to a complementary strand.
“Specifically hybridizable” refers to an antisense compound having a sufficient degree of complementarity between an antisense oligonucleotide and a target nucleic acid to induce a desired effect, while exhibiting minimal or no effects on non-target nucleic acids under conditions in which specific binding is desired, i.e., under physiological conditions in the case of in vivo assays and therapeutic treatments.
“Subject” means a human selected for treatment or therapy.
“Targeting” or “targeted” means the process of design and selection of an antisense compound that will specifically hybridize to a target nucleic acid and induce a desired effect.
“Target nucleic acid,” “target RNA,” “target mRNA,” and “target RNA transcript” all refer to a nucleic acid capable of being targeted by antisense compounds.
“Target segment” means the sequence of nucleotides of a target nucleic acid to which an antisense compound is targeted. “5′ target site” refers to the 5′-most nucleotide of a target segment. “3′ target site” refers to the 3′-most nucleotide of a target segment.
“Therapeutically effective amount” means an amount of a pharmaceutical agent that provides a therapeutic benefit to an individual.
“Treat” refers to administering a pharmaceutical composition to effect an alteration or improvement of a disease, disorder, or condition.
“Unmodified nucleotide” means a nucleotide composed of naturally occurring nucleobases, sugar moieties, and internucleoside linkages. In certain embodiments, an unmodified nucleotide is an RNA nucleotide (i.e. β-D-ribonucleosides) or a DNA nucleotide (i.e. β-D-deoxyribonucleoside).
Certain Embodiments
In certain aspects, there is provided a method of treating cancer in a subject which comprises administering to the subject an inhibitor of the JAK-STAT pathway. In certain embodiments the cancer is B-cell lymphoma or hepatocellular carcinoma (HCC).
In certain aspects, there is provided a method of treating B-cell lymphoma in a subject which comprises administering to the subject an inhibitor of the JAK-STAT pathway.
In certain aspects, there is provided a method of treating cancer, such as B-cell lymphoma or HCC, in a subject which comprises administering to the subject a weekly dose of an antisense compound complementary to a nucleic acid encoding human STAT3, wherein the dose comprises about 0.2 to 3.5 milligrams of the antisense compound per kilogram of the subject's body weight per week (0.2-3.5 mg/kg/wk). In certain embodiments, the dose is about 0.2 mg, about 0.3 mg, about 0.4 mg, about 0.5 mg, about 0.6 mg, about 0.7 mg, about 0.8 mg, about 0.9 mg, about 1.0 mg, about 1.1 mg, about 1.2 mg, about 1.3 mg, about 1.4 mg, about 1.5 mg, about 1.6 mg, about 1.7 mg, about 1.8 mg, about 1.9 mg, about 2.0 mg, about 2.1 mg, about 2.2 mg, about 2.3 mg, about 2.4 mg, about 2.5 mg, about 2.6 mg, about 2.7 mg, about 2.8 mg, about 2.9 mg, about 3.0 mg, about 3.1 mg, about 3.2 mg, about 3.3 mg, about 3.4 mg, or about 3.5 mg of the antisense compound per kilogram of the subject's body weight. In certain embodiments, the dose comprises about 1.5 to 3.5 milligrams of the antisense compound per kilogram of the subject's body weight (1.5-3.5 mg/kg/wk. In certain embodiments, the dose is 2.0 milligrams of the antisense compound per kilogram of the subject's body weight per week (2.0 mg/kg/wk). In certain embodiments, the dose is effective to treat cancer and acceptably tolerable. The dose can be administered for at least 1-52 weeks, at least 1-10 weeks, at least 1-7 weeks, at least 1-5 weeks, at least 5 weeks, at least 6 weeks, or at least 7 weeks. In certain embodiments, the dose can be administered to the subject 1, 2, 3, 4, 5, 6, or 7 times per week. In certain embodiments, the dose is administered to the subject 1-6 times per week. In several embodiments, the dose can be administered 6 times during the first week and 1 time each subsequent week. In certain embodiments, the subject's body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a single dose of a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein the single dose comprises an amount of the compound in the range of about 15-250 mg. In certain embodiments, the single dose comprises an amount of the compound in the range of about 100-250 mg. In certain embodiments, the single dose is an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 60 mg, about 70 mg, about 80 mg, about 90 mg, about 100 mg, about 110 mg, about 120 mg, about 130 mg, about 140 mg, about 150 mg, about 160 mg, about 170 mg, about 180 mg, about 190 mg, about 200 mg, about 210 mg, about 220 mg, about 230 mg, about 240 mg, or about 250 mg. In certain embodiments, the dose is effective to treat cancer and acceptably tolerable.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a total weekly dose of a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein the total weekly dose comprises an amount of the compound in the range of about 15-750 mg weekly. In certain embodiments, the total weekly dose comprises an amount of the compound in the range of about 100-750 mg weekly. In certain embodiments, the total weekly dose is an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, or about 750 mg. In certain embodiments, the dose is effective to treat cancer and acceptably tolerable. The total weekly dose can be administered in 2, 3, 4, 5, 6, or 7 equal doses within a week, such that the total weekly dose does not exceed about 750 mg. In certain embodiments, the total weekly dose is administered in 3 equal doses within a week. It will be understood that the aforementioned total weekly dose ranges can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the total weekly dose by the subject's body weight, such as the subject's ideal body weight. For example, dividing the aforementioned total weekly dose by an average adult body weight of 70 kg, in certain embodiments the total weekly dose can be represented as an amount of about 15 mg/70 kg (0.2 mg/kg/wk) to 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, the total weekly dose can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), about 250 mg/70 kg (3.6 mg/kg/wk), about 275 mg/70 kg (3.9 mg/kg/wk), about 300 mg/70 kg (4.3 mg/kg/wk), about 325 mg/70 kg (4.6 mg/kg/wk), about 350 mg/70 kg (5.0 mg/kg/wk), about 375 mg/70 kg (5.4 mg/kg/wk), about 400 mg/70 kg (5.7 mg/kg/wk), about 425 mg/70 kg (6.1 mg/kg/wk), about 450 mg/70 kg (6.4 mg/kg/wk), about 475 mg/70 kg (6.8 mg/kg/wk), about 500 mg/70 kg (7.1 mg/kg/wk), about 525 mg/70 kg (7.5 mg/kg/wk), about 550 mg/70 kg (7.9 mg/kg/wk), about 575 mg/70 kg (8.2 mg/kg/wk), about 600 mg/70 kg (8.6 mg/kg/wk), about 625 mg/70 kg (8.9 mg/kg/wk), about 650 mg/70 kg (9.3 mg/kg/wk), about 675 mg/70 kg (9.6 mg/kg/wk), about 700 mg/70 kg (10.0 mg/kg/wk), about 725 mg/70 kg (10.4 mg/kg/wk), or about 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain aspects, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a loading phase comprising a total weekly dose in the range of about 15-750 mg for the first 1-10 weeks, and
a maintenance phase comprising a total weekly dose in the range of 15-250 mg for at least 1 week after the loading phase.
In certain embodiments, the loading phase is 1 week, 2 weeks, 3 weeks, 4 weeks, or 5 weeks. In certain embodiments, the loading phase comprises administering the compound in 2, 3, 4, 5, 6, or 7 equal doses within a week. In certain embodiments, the loading phase comprises administering the compound in 3 equal doses within a week. In several embodiments, the total weekly dose of the antisense compound in the loading phase is an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, or about 750 mg. It will be understood that the aforementioned total weekly dose ranges in the loading phase can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the total weekly dose by the subject's body weight, such as the subject's ideal body weight. For example, dividing the aforementioned total weekly dose in the loading phase by an average adult body weight of 70 kg, in certain embodiments the total weekly dose can be represented as an amount of about 15 mg/70 kg (0.2 mg/kg/wk) to 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, the total weekly dose in the loading phase can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), about 250 mg/70 kg (3.6 mg/kg/wk), about 275 mg/70 kg (3.9 mg/kg/wk), about 300 mg/70 kg (4.3 mg/kg/wk), about 325 mg/70 kg (4.6 mg/kg/wk), about 350 mg/70 kg (5.0 mg/kg/wk), about 375 mg/70 kg (5.4 mg/kg/wk), about 400 mg/70 kg (5.7 mg/kg/wk), about 425 mg/70 kg (6.1 mg/kg/wk), about 450 mg/70 kg (6.4 mg/kg/wk), about 475 mg/70 kg (6.8 mg/kg/wk), about 500 mg/70 kg (7.1 mg/kg/wk), about 525 mg/70 kg (7.5 mg/kg/wk), about 550 mg/70 kg (7.9 mg/kg/wk), about 575 mg/70 kg (8.2 mg/kg/wk), about 600 mg/70 kg (8.6 mg/kg/wk), about 625 mg/70 kg (8.9 mg/kg/wk), about 650 mg/70 kg (9.3 mg/kg/wk), about 675 mg/70 kg (9.6 mg/kg/wk), about 700 mg/70 kg (10.0 mg/kg/wk), about 725 mg/70 kg (10.4 mg/kg/wk), or about 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, the maintenance phase comprises administering the compound in 2, 3, 4, 5, 6, or 7 equal doses within a week. In several embodiments, the total weekly dose of the antisense compound in the maintenance phase is an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 60 mg, about 70 mg, about 80 mg, about 90 mg, about 100 mg, about 110 mg, about 120 mg, about 130 mg, about 140 mg, about 150 mg, about 160 mg, about 170 mg, about 180 mg, about 190 mg, about 200 mg, about 210 mg, about 220 mg, about 230 mg, about 240 mg, or about 250 mg. In certain embodiments, the total weekly dose in the maintenance phase is administered as a single dose per week. It will be understood that the aforementioned total weekly dose ranges in the maintenance phase can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the total weekly dose by the subject's body weight, such as the subject's ideal body weight. For example, dividing the aforementioned total weekly dose by an average adult body weight of 70 kg, in certain embodiments the total weekly dose in the maintenance phase can be represented as an amount of about 15 mg/70 kg (0.2 mg/kg/wk) to 250 mg/70 kg (3.6 mg/kg/wk). In certain embodiments, the total weekly dose can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), or about 250 mg/70 kg (3.6 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a loading phase about 6, 7, 8, 9, or 10 weeks, and
a maintenance phase comprising a dose of about 2 mg/kg/wk for at least 1 week after the loading phase. In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a loading phase comprising a dose in the range of about 3 to 4 mg/kg/wk for about 6, 7, 8, 9, or 10 weeks, and
a maintenance phase comprising a dose of about 2 mg/kg/wk for at least 1 week after the loading phase. In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a loading phase comprising a dose of about 3 mg/kg/wk for about 8 weeks, and
a maintenance phase comprising a dose of about 2 mg/kg/wk for at least 1 week after the loading phase. In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a first phase comprising a total weekly dose in the range of about 15-750 mg for the first 1-10 weeks, and
a second phase comprising a total weekly dose in the range of 15-250 mg for at least 1 week after the loading phase.
In certain embodiments, the first phase is 1 week, 2 weeks, 3 weeks, 4 weeks, or 5 weeks. In certain embodiments, the first phase comprises administering the compound in 2, 3, 4, 5, 6, or 7 equal doses within a week. In certain embodiments, the first phase comprises administering the compound in 3 equal doses within a week. In several embodiments, the total weekly dose of the antisense compound in the first phase is an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, or about 750 mg. It will be understood that the aforementioned total weekly dose ranges in the first phase can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the total weekly dose by the subject's body weight, such as the subject's ideal body weight. For example, dividing the aforementioned total weekly dose in the first phase by an average adult body weight of 70 kg, in certain embodiments the total weekly dose can be represented as an amount of about 15 mg/70 kg (0.2 mg/kg/wk) to 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, the total weekly dose in the first phase can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), about 250 mg/70 kg (3.6 mg/kg/wk), about 275 mg/70 kg (3.9 mg/kg/wk), about 300 mg/70 kg (4.3 mg/kg/wk), about 325 mg/70 kg (4.6 mg/kg/wk), about 350 mg/70 kg (5.0 mg/kg/wk), about 375 mg/70 kg (5.4 mg/kg/wk), about 400 mg/70 kg (5.7 mg/kg/wk), about 425 mg/70 kg (6.1 mg/kg/wk), about 450 mg/70 kg (6.4 mg/kg/wk), about 475 mg/70 kg (6.8 mg/kg/wk), about 500 mg/70 kg (7.1 mg/kg/wk), about 525 mg/70 kg (7.5 mg/kg/wk), about 550 mg/70 kg (7.9 mg/kg/wk), about 575 mg/70 kg (8.2 mg/kg/wk), about 600 mg/70 kg (8.6 mg/kg/wk), about 625 mg/70 kg (8.9 mg/kg/wk), about 650 mg/70 kg (9.3 mg/kg/wk), about 675 mg/70 kg (9.6 mg/kg/wk), about 700 mg/70 kg (10.0 mg/kg/wk), about 725 mg/70 kg (10.4 mg/kg/wk), or about 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, the second phase comprises administering the compound in 2, 3, 4, 5, 6, or 7 equal doses within a week. In several embodiments, the total weekly dose of the antisense compound in the second phase is an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 60 mg, about 70 mg, about 80 mg, about 90 mg, about 100 mg, about 110 mg, about 120 mg, about 130 mg, about 140 mg, about 150 mg, about 160 mg, about 170 mg, about 180 mg, about 190 mg, about 200 mg, about 210 mg, about 220 mg, about 230 mg, about 240 mg, or about 250 mg. In certain embodiments, the total weekly dose in the second phase is administered as a single dose per week. It will be understood that the aforementioned total weekly dose ranges in the second phase can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the total weekly dose by the subject's body weight, such as the subject's ideal body weight. For example, dividing the aforementioned total weekly dose by an average adult body weight of 70 kg, in certain embodiments the total weekly dose in the second phase can be represented as an amount of about 15 mg/70 kg (0.2 mg/kg/wk) to 250 mg/70 kg (3.6 mg/kg/wk). In certain embodiments, the total weekly dose can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), or about 250 mg/70 kg (3.6 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a first phase for about 6, 7, 8, 9, or 10 weeks, and
a second phase comprising a dose of about 2 mg/kg/wk for at least 1 week after the loading phase. In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a first phase comprising a dose in the range of about 3 to 4 mg/kg/wk for about 6, 7, 8, 9, or 10 weeks, and
a second phase comprising a dose of about 2 mg/kg/wk for at least 1 week after the loading phase. In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, a method comprises administering to a subject having cancer, such as B-cell lymphoma or HCC, a pharmaceutical composition comprising an antisense compound complementary to a nucleic acid encoding human STAT3, wherein administering the antisense compound comprises:
a first phase comprising a dose of about 3 mg/kg/wk for about 8 weeks, and
a second phase comprising a dose of about 2 mg/kg/wk for at least 1 week after the loading phase. In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In any of the above embodiments, the B-cell lymphoma is a non-Hodgkin's B-cell lymphoma. Examples of non-Hodgkin's B-cell lymphoma of certain aspects include, but are not limited to, diffuse large B cell lymphoma (DLBCL), follicular lymphoma, mucosa-associated lymphatic tissue lymphoma (MALT), small cell lymphocytic lymphoma, chronic lymphocytic leukemia, mantle cell lymphoma (MCL), Burkitt lymphoma, mediastinal large B cell lymphoma, Waldenström macroglobulinemia, nodal marginal zone B cell lymphoma (NMZL), splenic marginal zone lymphoma (SMZL), intravascular large B-cell lymphoma, primary effusion lymphoma, and lymphomatoid granulomatosis. In certain embodiments, the non-Hodgkin's B-cell lymphoma is diffuse large B cell lymphoma (DLBCL).
In any of the above embodiments, the B-cell lymphoma is Hodgkin's B-cell lymphoma.
In any of the foregoing embodiments, administering the dose of the antisense compound reduces tumor size or tumor volume in the subject. In certain embodiments, administering the dose of the antisense compound prolongs survival of the subject. In certain embodiments, administering the dose of the antisense compound treats cancer, such as B-cell lymphoma, in the subject. In any of the above embodiments, the method is effective to treat cancer and acceptably tolerable in a subject.
In certain of the foregoing embodiments, the subject is identified as having cancer, such as B-cell lymphoma, prior to administering the antisense compound to the subject. In certain embodiments, the subject identified as having cancer, such as B-cell lymphoma, received or is currently receiving anti-cancer treatment, such as a first-line treatment regimen. For example, in certain embodiments the first-line treatment regimen is a combination of cyclophosphamide, hydroxydanuorubicin, oncovin (vincristine), prednisone or prednisolone (CHOP). In certain embodiments, the first-line treatment regimen is a combination of rituximab and CHOP (R-CHOP). In certain embodiments, the subject is refractory to a first-line treatment regimen such as CHOP and/or R-CHOP.
In any of the foregoing embodiments, the antisense compound comprises a modified oligonucleotide consisting of 12 to 30 linked nucleosides having a nucleobase sequence comprising a portion of at least 12 contiguous nucleobases complementary to an equal length portion of nucleobases 3008 to 3033 of SEQ ID NO: 1, wherein the nucleobase sequence is complementary to SEQ ID NO: 1.
In any of the foregoing embodiment, the antisense compound comprises a modified oligonucleotide consisting of 12 to 30 linked nucleosides having a nucleobase sequence comprising a portion of at least 12 contiguous nucleobases complementary to an equal length portion of nucleobases 3016 to 3031 of SEQ ID NO: 1, wherein the nucleobase sequence is complementary to SEQ ID NO: 1.
In any of the foregoing embodiments, the antisense compound comprises a modified oligonucleotide consisting of 12 to 30 linked nucleosides having a nucleobase sequence comprising a portion of at least 12 contiguous nucleobases complementary to an equal length portion of nucleobases 6476 to 6491 of SEQ ID NO: 2, wherein the nucleobase sequence is complementary to SEQ ID NO: 2.
In any of the foregoing embodiments, the antisense compound comprises a modified oligonucleotide consisting of 12 to 30 linked nucleosides having a nucleobase sequence comprising a portion of at least 12 contiguous nucleobases complementary to an equal length portion of nucleobases 250-286; 250-285; 264-285; 264-282; 728-745; 729-745; 729-744; 787-803; 867-883; 955-978; 1146-1170; 1896-1920; 1899-1920; 1899-1919; 1899-1918; 1899-1916; 1901-1916; 1946-1963; 1947-1963; 2155-2205; 2155-2187; 2156-2179; 2204-2221; 2681-2696; 2699-2716; 3001-3033; 3008-3033, 3010-3033, 3010-3032, 3015-3033, 3015-3032, 3015-3031, 3016-3033, 3016-3032, 3016-3033; 3452-3499; 3460-3476; 3583-3608; 3591-3616; 3595-3615; 3595-3614; 3595-3612; 3675-3706; 3713-3790; 3715-3735; 3833-3878; 3889-3932; 3977-4012; 4067-4100; 4225-4256; 4234-4252; 4235-4252; 4235-4251; 4236-4252; 4306-4341; 4431-4456; 4439-4454; 4471-4510; 4488-4505; 4530-4558; 4539-4572; 4541-4558; 4636-4801; 4782-4796; 4800-4823; 4811-4847; 4813-4859; 4813-4815; 4813-4831; 4827-4859; 4827-4844; or 4842-4859 of SEQ ID NO: 1, wherein the nucleobase sequence of the modified oligonucleotide is complementary to SEQ ID NO: 1.
In any of the foregoing embodiments, the antisense compound comprises a modified oligonucleotide consisting of 12 to 30 linked nucleosides having a nucleobase sequence comprising a portion of at least 12 contiguous nucleobases complementary to an equal length portion of nucleobases 2668-2688; 2703-2720; 5000-5021; 5001-5017; 5697-5722; 5699-5716; 6475-6490; 6475-6491; 6476-6491; 7682-7705; 8078-8097; 8079-8095; 9862-9811; 9870-9897; 9875-9893; 9875-9891; 9877-9893; 11699-11719; 12342-12366; 12345-12364; 12346-12364; 12347-12364; 12353-12380; 12357-12376; 12358-12376; 12358-12373; 12360-12376; 14128-14148; 16863-16883; 46091-46111; 50692-50709; 50693-50709; 50693-50708; 61325-61349; 66133-66157; 66136-66157; 66136-66155; 66136-66153; 66138-66153; 66184-66200; 67067-67083; 4171-74220; 74199-74220; 74202-74220; 74171-74219; 74199-74219; 74202-74219; 74171-74218; 74199-74218; 74202-74218; 74723-74768; 74764-74803; 74782-74802; 74782-74801; 74782-74800; 74782-74799; 74783-74802; 74783-74801; 74783-74800; 74783-74799; 74862-74893; 74900-74977; 74902-74922; 74902-74920; 75070-75119; 75164-75199; 75254-75287; 75412-75443; 75421-75439; 75422-75439; 75422-75438; 75423-75439; 75423-75438; 75493-75528; 75616-75643; 75626-75641; 75658-75699; 75676-75692; 75717-75745; 75726-75759; 75726-75745; 75727-75745; 75728-75745; 75831-75988; 75852-75969; 75969-75984; 75987-76056; 76000-76046; 76000-76032; 76000-76018; 76014-76046; 76014-76032; 76029-76046; or 76031-76046 of SEQ ID NO: 2, wherein the nucleobase sequence of the modified oligonucleotide is complementary to SEQ ID NO: 2.
In certain embodiments, the nucleobase sequence of the modified oligonucleotide comprises the sequence of SEQ ID NO: 12 or consists of the sequence of SEQ ID NO: 12. In certain embodiments, the modified oligonucleotide is 100% complementary to SEQ ID NO: 1 or 2.
In certain embodiments, the nucleobase sequence of the modified oligonucleotide comprises the sequence of any of the STAT3 antisense oligonucleotides described in WO 2012/135736, which is incorporated by reference in its entirety herein.
In certain embodiments, the modified oligonucleotide is a single-stranded modified oligonucleotide. In certain embodiments, the modified oligonucleotide comprises at least one modified internucleoside linkage. In several embodiments, each internucleoside linkage is a phosphorothioate internucleoside linkage. In certain embodiments, at least one nucleoside comprises a modified sugar, such as a bicyclic sugar including, but not limited to, a 4′-CH 2 —O-2′ bridge or a 4′-CH(CH 3 )—O-2′ bridge. In certain embodiments, the modified sugar comprises a 2′-O(CH 2 ) 2 —OCH 3 group. In certain embodiments, at least one nucleoside comprises a modified nucleobase, such as a 5-methylcytosine.
In certain embodiments, the modified oligonucleotide comprises:
a 5′-wing consisting of 1 to 5 linked nucleosides;
a 3′-wing consisting of 1 to 5 linked nucleosides; and
a gap between the 5′-wing and the 3′-wing consisting of 8 to 12 linked 2′-deoxynucleosides;
wherein at least one of the 5′-wing and the 3′-wing comprises at least one bicyclic nucleoside or one 2′-substituted nucleoside. In certain embodiments, the 2′-substituted nucleoside comprises a 2′-O(CH 2 ) 2 —OCH 3 group or a 2′-O—CH 3 group. In certain embodiments, the bicyclic nucleoside comprises a 4′-CH 2 —O-2′ bridge or a 4′-CH(CH 3 )—O-2′ bridge.
In certain embodiments, pharmaceutical compositions described herein are administered in the form of a dosage unit (e.g., injection, infusion, etc.). In certain embodiments, such pharmaceutical compositions comprise an antisense oligonucleotide in an amount of any of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, or about 750 mg. It will be understood that the aforementioned amounts of antisense oligonucleotide can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the amount by the subject's body weight per week. For example, dividing the aforementioned amounts by an average adult body weight of 70 kg, in certain embodiments the dosage unit can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), about 250 mg/70 kg (3.6 mg/kg/wk), about 275 mg/70 kg (3.9 mg/kg/wk), about 300 mg/70 kg (4.3 mg/kg/wk), about 325 mg/70 kg (4.6 mg/kg/wk), about 350 mg/70 kg (5.0 mg/kg/wk), about 375 mg/70 kg (5.4 mg/kg/wk), about 400 mg/70 kg (5.7 mg/kg/wk), about 425 mg/70 kg (6.1 mg/kg/wk), about 450 mg/70 kg (6.4 mg/kg/wk), about 475 mg/70 kg (6.8 mg/kg/wk), about 500 mg/70 kg (7.1 mg/kg/wk), about 525 mg/70 kg (7.5 mg/kg/wk), about 550 mg/70 kg (7.9 mg/kg/wk), about 575 mg/70 kg (8.2 mg/kg/wk), about 600 mg/70 kg (8.6 mg/kg/wk), about 625 mg/70 kg (8.9 mg/kg/wk), about 650 mg/70 kg (9.3 mg/kg/wk), about 675 mg/70 kg (9.6 mg/kg/wk), about 700 mg/70 kg (10.0 mg/kg/wk), about 725 mg/70 kg (10.4 mg/kg/wk), or about 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464.
In certain embodiments, pharmaceutical compositions described herein comprise a dose of antisense oligonucleotide in an amount in the range of about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, or about 750 mg. It will be understood that the aforementioned amounts of antisense oligonucleotide can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the amount by the subject's body weight per week. For example, dividing the aforementioned amounts by an average adult body weight of 70 kg, in certain embodiments the dose of antisense oligonucleotide can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), about 250 mg/70 kg (3.6 mg/kg/wk), about 275 mg/70 kg (3.9 mg/kg/wk), about 300 mg/70 kg (4.3 mg/kg/wk), about 325 mg/70 kg (4.6 mg/kg/wk), about 350 mg/70 kg (5.0 mg/kg/wk), about 375 mg/70 kg (5.4 mg/kg/wk), about 400 mg/70 kg (5.7 mg/kg/wk), about 425 mg/70 kg (6.1 mg/kg/wk), about 450 mg/70 kg (6.4 mg/kg/wk), about 475 mg/70 kg (6.8 mg/kg/wk), about 500 mg/70 kg (7.1 mg/kg/wk), about 525 mg/70 kg (7.5 mg/kg/wk), about 550 mg/70 kg (7.9 mg/kg/wk), about 575 mg/70 kg (8.2 mg/kg/wk), about 600 mg/70 kg (8.6 mg/kg/wk), about 625 mg/70 kg (8.9 mg/kg/wk), about 650 mg/70 kg (9.3 mg/kg/wk), about 675 mg/70 kg (9.6 mg/kg/wk), about 700 mg/70 kg (10.0 mg/kg/wk), about 725 mg/70 kg (10.4 mg/kg/wk), or about 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
The compositions described herein may additionally contain other adjunct components conventionally found in pharmaceutical compositions, at their art-established usage levels. Thus, for example, the compositions may contain additional, compatible, pharmaceutically-active materials such as, for example, antipruritics, astringents, local anesthetics or anti-inflammatory agents. However, such materials, when added, should not unduly interfere with the biological activities of the components of the compositions described herein. The formulations can be sterilized and, if desired, mixed with auxiliary agents, e.g., preservatives, stabilizers, wetting agents, emulsifiers, salts for influencing osmotic pressure, buffers, colorings, and/or aromatic substances and the like which do not deleteriously interact with the oligonucleotide(s) of the formulation.
Antisense oligonucleotides may be covalently linked to one or more moieties or conjugates which enhance the activity, cellular distribution or cellular uptake of the antisense oligonucleotides. Typical conjugate groups include cholesterol moieties and lipid moieties. Additional conjugate groups include carbohydrates, phospholipids, biotin, phenazine, folate, phenanthridine, anthraquinone, acridine, fluoresceins, rhodamines, coumarins, and dyes.
Antisense oligonucleotides can also be modified to have one or more stabilizing groups that are generally attached to one or both termini of antisense compounds to enhance properties such as, for example, nuclease stability. Included in stabilizing groups are cap structures. These terminal modifications protect the antisense oligonucleotide having terminal nucleic acid from exonuclease degradation, and can help in delivery and/or localization within a cell. The cap can be present at the 5′-terminus (5′-cap), or at the 3′-terminus (3′-cap), or can be present on both termini. Cap structures are well known in the art and include, for example, inverted deoxy abasic caps. Further 3′ and 5′-stabilizing groups that can be used to cap one or both ends of an antisense compound to impart nuclease stability include those disclosed in WO 03/004602 published on Jan. 16, 2003.
Certain Treatments
In certain aspects there is provided a method of treating a subject suffering from cancer comprising administering to the subject an antisense compound complementary to human STAT3. In certain embodiments the antisense compound complementary to human STAT3 is as described herein or as disclosed in WO2012/135736.
In certain embodiments the cancer is selected from B-cell lymphoma or hepatocellularcarcinoma. In certain aspects there is provided an antisense compound complementary to human STAT3 for use in treating cancer. In certain embodiments the antisense compound complementary to human STAT3 is as described herein or as disclosed in WO2012/135736. In certain embodiments the cancer is selected from B-cell lymphoma or hepatocellularcarcinoma.
In certain aspects there is provided an antisense compound complementary to human STAT3 for use in a method of treating cancer in a subject in need thereof, wherein the method comprises administering to the subject the antisense compound in a loading phase and then a maintenance phase, wherein the loading phase involves administering a total weekly dose of the compound in the range of about 15-750 mg for the first 1-10 weeks, and the maintenance phase involves administering a total weekly dose in the range of 15-250 mg for at least 1 week after the loading phase. In certain embodiments the antisense compound complementary to human STAT3 is as described herein or as disclosed in WO2012/135736. In certain embodiments the cancer is selected from B-cell lymphoma or hepatocellularcarcinoma.
Certain aspects are directed to use of an antisense compound complementary to human STAT3 for the manufacture of a medicament for treating cancer. In certain embodiments the antisense compound complementary to human STAT3 is as described herein or as disclosed in WO2012/135736. In certain embodiments the cancer is selected from B-cell lymphoma or hepatocellularcarcinoma.
In particular embodiments of any of these aspects, the B-cell lymphoma is a non-Hodgkin's B-cell lymphoma. Examples of non-Hodgkin's B-cell lymphoma of certain aspects include, but are not limited to, diffuse large B cell lymphoma (DLBCL), follicular lymphoma, mucosa-associated lymphatic tissue lymphoma (MALT), small cell lymphocytic lymphoma, chronic lymphocytic leukemia, mantle cell lymphoma (MCL), Burkitt lymphoma, mediastinal large B cell lymphoma, Waldenström macroglobulinemia, nodal marginal zone B cell lymphoma (NMZL), splenic marginal zone lymphoma (SMZL), intravascular large B-cell lymphoma, primary effusion lymphoma, and lymphomatoid granulomatosis. In certain embodiments, the non-Hodgkin's B-cell lymphoma is diffuse large B cell lymphoma (DLBCL).
Certain Dosing Regimens
In certain embodiments, pharmaceutical compositions are administered according to a dosing regimen. In certain such embodiments, the dosing regimen comprises a loading phase and a maintenance phase. In certain such embodiments, the dosing regimen is effective to treat cancer and acceptably tolerable in a subject. In certain embodiments, the pharmaceutical composition comprises an antisense oligonucleotide. In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464.
In certain embodiments, the loading phase includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or more than 20 doses.
In certain embodiments, the loading phase lasts from 1 day to 6 months. In certain embodiments a loading phase lasts 1 day, 2 days, 3, days, 4, days, 5 days, 6 days, or 7 days as measured from administration of the first dose of the loading phase to administration of the first dose of the maintenance phase. In certain embodiments a loading phase lasts 1 week, 2 weeks, 3, weeks, 4, weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, or 26 weeks as measured from administration of the first dose of the loading phase to administration of the first dose of the maintenance phase. In certain embodiments, the loading phase lasts 1 month, 2 months, 3 months, 4 months, 5 months, or 6 months as measured from administration of the first dose of the loading phase to administration of the first dose of the maintenance phase.
In certain embodiments, the dose administered during the loading phase is lower than the dose administered during the maintenance phase. In certain embodiments, the dose administered during the loading phase is lower than the dose administered during the maintenance phase to avoid undesired side effects. In certain embodiments, the undesired side effect is increased liver markers. In certain embodiments, the undesired side effect is increased ALT. In certain embodiments, the undesired side effect is increased AST. In certain embodiments, the undesired side effect is thrombocytopenia or neutropenia.
In certain embodiments, the dose administered during the loading phase is higher than the dose administered during the maintenance phase. In certain embodiments, the dose administered during the loading phase is higher than the dose administered during the maintenance phase to quickly achieve steady state reduction of STAT3 mRNA expression, STAT3 protein expression, and/or STAT3 activity. In certain embodiments, the dose administered during the loading phase is higher than the dose administered during the maintenance phase to avoid undesired side effects in the maintenance phase. In certain embodiments, the undesired side effect is increased liver markers. In certain embodiments, the undesired side effect is increased ALT. In certain embodiments, the undesired side effect is increased AST. In certain embodiments, the undesired side effect is thrombocytopenia or neutropenia.
In certain embodiments where the loading phase includes more than one dose, the doses administered during the loading phase are all the same amount as one another. In certain embodiments, the doses administered during the loading phase are not all the same amount. In certain embodiments, the doses given during the loading phase increase over time. In certain embodiments, the doses given during the loading phase decrease over time.
In certain embodiments, a loading dose is administered by parenteral administration. In certain embodiments, the parenteral administration is subcutaneous administration. In certain embodiments, the parenteral administration is intravenous infusion.
In certain embodiments, the doses administered during the loading phase are about 0.2 mg, about 0.3 mg, about 0.4 mg, about 0.5 mg, about 0.6 mg, about 0.7 mg, about 0.8 mg, about 0.9 mg, about 1.0 mg, about 1.1 mg, about 1.2 mg, about 1.3 mg, about 1.4 mg, about 1.5 mg, about 1.6 mg, about 1.7 mg, about 1.8 mg, about 1.9 mg, about 2.0 mg, about 2.1 mg, about 2.2 mg, about 2.3 mg, about 2.4 mg, about 2.5 mg, about 2.6 mg, about 2.7 mg, about 2.8 mg, about 2.9 mg, about 3.0 mg, about 3.1 mg, about 3.2 mg, about 3.3 mg, about 3.4 mg, or about 3.5 mg of the antisense compound per kilogram of the subject's body weight. In certain embodiments, the dose is 2.0 milligrams of the antisense compound per kilogram of the subject's body weight per week (2.0 mg/kg/wk). In certain embodiments, the subject's body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, the doses administered during the loading phase are about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 75 mg, about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, or about 750 mg. It will be understood that the aforementioned doses of antisense oligonucleotide can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the amount by the subject's body weight per week. For example, dividing the aforementioned amounts by an average adult body weight of 70 kg, in certain embodiments the doses can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), about 250 mg/70 kg (3.6 mg/kg/wk), about 275 mg/70 kg (3.9 mg/kg/wk), about 300 mg/70 kg (4.3 mg/kg/wk), about 325 mg/70 kg (4.6 mg/kg/wk), about 350 mg/70 kg (5.0 mg/kg/wk), about 375 mg/70 kg (5.4 mg/kg/wk), about 400 mg/70 kg (5.7 mg/kg/wk), about 425 mg/70 kg (6.1 mg/kg/wk), about 450 mg/70 kg (6.4 mg/kg/wk), about 475 mg/70 kg (6.8 mg/kg/wk), about 500 mg/70 kg (7.1 mg/kg/wk), about 525 mg/70 kg (7.5 mg/kg/wk), about 550 mg/70 kg (7.9 mg/kg/wk), about 575 mg/70 kg (8.2 mg/kg/wk), about 600 mg/70 kg (8.6 mg/kg/wk), about 625 mg/70 kg (8.9 mg/kg/wk), about 650 mg/70 kg (9.3 mg/kg/wk), about 675 mg/70 kg (9.6 mg/kg/wk), about 700 mg/70 kg (10.0 mg/kg/wk), about 725 mg/70 kg (10.4 mg/kg/wk), or about 750 mg/70 kg (10.7 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, dose, dose frequency, and duration of the loading phase may be selected to achieve a desired effect. In certain embodiments, those variables are adjusted to result in a desired concentration of pharmaceutical agent in a subject. For example, in certain embodiments, dose and dose frequency are adjusted to provide plasma concentration of a pharmaceutical agent at an amount sufficient to achieve a desired effect. In certain embodiments, the plasma concentration is maintained above the minimal effective concentration (MEC). In certain embodiments, pharmaceutical compositions described herein are administered with a dosage regimen designed to maintain a concentration above the MEC for 10-90% of the time, between 30-90% of the time, or between 50-90% of the time. In certain embodiments, the pharmaceutical composition comprises an antisense oligonucleotide. In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464.
In certain embodiments, doses, dose frequency, and duration of the loading phase may be selected to achieve a desired plasma trough concentration of a pharmaceutical composition. In certain embodiments, the pharmaceutical composition comprises an antisense oligonucleotide. In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464. In certain embodiments, the desired plasma trough concentration is from 5-100 ng/mL. In certain embodiments, the desired plasma trough concentration is from 5-50 ng/mL. In certain embodiments, the desired plasma trough concentration is from 10-40 ng/mL. In certain embodiments, the desired plasma trough concentration is from 15-35 ng/mL. In certain embodiments, the desired plasma trough concentration is from 20-30 ng/mL.
In certain embodiments, dose, dose frequency, and duration of the loading phase may be selected to achieve a desired effect within 1 to 26 weeks. In certain embodiments, the dose is the same and the dose frequency is varied to achieve the desired effect within 1 to 26 weeks. In certain embodiments, the dose increases over time and the dose frequency remains constant. In certain embodiments, one or more doses of the loading phase are greater than one or more doses of the maintenance phase. In certain embodiments, each of the loading doses is greater than each of the maintenance doses. In certain embodiments, it is desirable to achieve a desired effect as quickly as possible. In certain embodiments, a loading phase with a high dose and/or high dose frequency may be desirable.
In certain embodiments, doses, dose frequency, and duration of the loading phase may be selected to achieve an acceptable safety profile. For example, in certain embodiments, such variables may be selected to mitigate toxicity of the pharmaceutical composition. In certain embodiments, such variables are selected to mitigate liver toxicity. In certain embodiments, such variables are selected to mitigate renal toxicity. In certain embodiments, such variables are selected to mitigate thrombocytopenia or neutropenia.
In certain embodiments, doses increase over time. In certain embodiments, one or more doses of the loading phase are lower than one or more doses of the maintenance phase. In certain embodiments, a safety profile is not acceptable when ALT is 5-10 times the upper limit of normal. In certain embodiments, a safety profile is not acceptable when ALT is 5-10 times the upper limit of normal, and bilirubin is elevated two or more times the upper limit of normal. In certain embodiments, an acceptable safety profile comprises ALT elevations that are above three times the upper limit of normal, but do not exceed five times the upper limit of normal. In certain embodiments, an acceptable safety profile comprises ALT elevations that are above three times the upper limit of normal, but do not exceed five times the upper limit of normal, and bilirubin elevations that do not exceed two times the upper limit of normal. In certain embodiments, when administration of a pharmaceutical composition of the invention results in ALT elevations that are above three times the upper limit of normal, the dose and/or dose frequency is adjusted to mitigate the ALT elevation.
In certain embodiments, the maintenance phase includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more than 20 doses.
In certain embodiments, the maintenance phase lasts from one day to the lifetime of the subject. In certain embodiments, the maintenance phase lasts 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, or 7 days as measured from administration of the last dose of the loading phase to administration of the last dose of the maintenance phase. In certain embodiments, the maintenance phase lasts 1 week, 2 weeks, 3, weeks, 4, weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, or 52 weeks as measured from administration of the last dose of the loading phase to administration of the last dose of the maintenance phase. In certain embodiments, the maintenance phase lasts 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, or 12 months as measured from administration of the last dose of the loading phase to administration of the last dose of the maintenance phase. In certain embodiments, the maintenance phase lasts 1 year, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, 9 years, 10 years, 11 years, 12 years, 13 years, 14 years, 15 years, 16 years, 17 years, 18 years, 19 years, 20 years, 21 years, 22 years, 23 years, 24 years, 25 years, 26 years, 27 years, 28 years, 29 years, 30 years, 31 years, 32 years, 33 years, 34 years 35 years, 36 years, 37 years, 38 years, 39 years, 40 years, 41 years, 42 years, 43 years, 44 years, 45 years, 46 years, 47 years, 48 years, 49 years, or 50 years as measured from administration of the last dose of the loading phase to administration of the last dose of the maintenance phase. In certain embodiments, the maintenance phase lasts as long as the dose continues to be needed, effective, and tolerated.
In certain embodiments where the maintenance phase includes more than one dose, the doses administered during the maintenance phase are all the same as one another. In certain embodiments, the doses administered during the maintenance phase are not all the same. In certain embodiments, the doses increase over time. In certain embodiments, the doses decrease over time.
In certain embodiments, a maintenance dose is administered by parenteral administration. In certain embodiments, the parenteral administration is subcutaneous administration. In certain embodiments, the parenteral administration is intravenous infusion.
In certain embodiments, the doses during the maintenance phase are about 0.2 mg, about 0.3 mg, about 0.4 mg, about 0.5 mg, about 0.6 mg, about 0.7 mg, about 0.8 mg, about 0.9 mg, about 1.0 mg, about 1.1 mg, about 1.2 mg, about 1.3 mg, about 1.4 mg, about 1.5 mg, about 1.6 mg, about 1.7 mg, about 1.8 mg, about 1.9 mg, about 2.0 mg, about 2.1 mg, about 2.2 mg, about 2.3 mg, about 2.4 mg, about 2.5 mg, about 2.6 mg, about 2.7 mg, about 2.8 mg, about 2.9 mg, about 3.0 mg, about 3.1 mg, about 3.2 mg, about 3.3 mg, about 3.4 mg, or about 3.5 mg of the antisense compound per kilogram of the subject's body weight. In certain embodiments, the dose is 2.0 milligrams of the antisense compound per kilogram of the subject's body weight per week (2.0 mg/kg/wk). In certain embodiments, the subject's body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, the doses during the maintenance phase are about 15 mg, about 20 mg, about 30 mg, about 40 mg, about 50 mg, about 60 mg, about 70 mg, about 80 mg, about 90 mg, about 100 mg, about 110 mg, about 120 mg, about 130 mg, about 140 mg, about 150 mg, about 160 mg, about 170 mg, about 180 mg, about 190 mg, about 200 mg, about 210 mg, about 220 mg, about 230 mg, about 240 mg, or about 250 mg. It will be understood that the aforementioned doses of antisense oligonucleotide can be readily represented as milligrams of the antisense compound per kilogram of the subject's body weight per week (mg/kg/wk) by simply dividing the amount by the subject's body weight per week. For example, dividing the aforementioned amounts by an average adult body weight of 70 kg, in certain embodiments the doses can be represented as any of about 15 mg/70 kg (0.2 mg/kg/wk), about 20 mg/70 kg (0.3 mg/kg/wk), about 30 mg/70 kg (0.4 mg/kg/wk), about 40 mg/70 kg (0.6 mg/kg/wk), about 50 mg/70 kg (0.7 mg/kg/wk), about 75 mg/70 kg (1.1 mg/kg/wk), about 100 mg/70 kg (1.4 mg/kg/wk), about 125 mg/70 kg (1.8 mg/kg/wk), about 150 mg/70 kg (2.1 mg/kg/wk), about 175 mg/70 kg (2.5 mg/kg/wk), about 200 mg/70 kg (2.9 mg/kg/wk), about 225 mg/70 kg (3.2 mg/kg/wk), or about 250 mg/70 kg (3.6 mg/kg/wk). In certain embodiments, body weight is calculated as the ideal body weight using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet.
In certain embodiments, doses, dose frequency, and duration of the maintenance phase may be selected to achieve a desired effect. In certain embodiments, those variables are adjusted to result in a desired concentration of pharmaceutical agent in a subject. For example, in certain embodiments, dose and dose frequency are adjusted to provide plasma concentration of a pharmaceutical agent described herein at an amount sufficient to achieve a desired effect. In certain embodiments, the plasma concentration is maintained above the minimal effective concentration (MEC). In certain embodiments, pharmaceutical compositions described herein are administered with a dosage regimen designed to maintain a concentration above the MEC for 10-90% of the time, between 30-90% of the time, or between 50-90% of the time.
In certain embodiments, doses, dose frequency, and duration of the maintenance phase may be selected to achieve a desired plasma trough concentration of a pharmaceutical composition. In certain embodiments, the pharmaceutical composition is an antisense oligonucleotide. In certain embodiments, the desired plasma trough concentration is from 5-100 ng/mL. In certain embodiments, the desired plasma trough concentration is from 5-50 ng/mL. In certain embodiments, the desired plasma trough concentration is from 10-40 ng/mL. In certain embodiments, the desired plasma trough concentration is from 15-35 ng/mL. In certain embodiments, the desired plasma trough concentration is from 20-30 ng/mL.
In certain embodiments, doses, dose frequency, and duration of the maintenance phase may be selected to achieve a desired safety profile. For example, in certain embodiments, such variables may be selected to mitigate toxicity of the pharmaceutical composition. In certain embodiments, such variables are selected to mitigate liver toxicity. In certain embodiments, such variables are selected to mitigate renal toxicity. In certain embodiments, such variables are selected to mitigate thrombocytopenia or neutropenia.
In certain embodiments, doses, dose frequency, and duration of the maintenance phase may be adjusted from time to time to achieve a desired effect. In certain embodiments, subjects are monitored for effects (therapeutic and/or toxic effects) and doses, dose frequency, and/or duration of the maintenance phase may be adjusted based on the results of such monitoring.
In certain embodiments, pharmaceutical compositions are administered according to a dosing regimen comprising a first phase and a second phase. In certain embodiments, the pharmaceutical composition comprises an antisense oligonucleotide. In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464.
In certain embodiments, the first phase includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or more than 20 doses.
In certain embodiments, the first phase lasts from 1 day to 6 months. In certain embodiments a first phase lasts 1 day, 2 days, 3, days, 4, days, 5 days, 6 days, or 7 days as measured from administration of the first dose of the first phase to administration of the first dose of the second phase. In certain embodiments a first phase lasts 1 week, 2 weeks, 3, weeks, 4, weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, or 26 weeks as measured from administration of the first dose of the first phase to administration of the first dose of the second phase. In certain embodiments, the first phase lasts 1 month, 2 months, 3 months, 4 months, 5 months, or 6 months as measured from administration of the first dose of the first phase to administration of the first dose of the second phase.
In certain embodiments, the dose administered during the first phase is lower than the dose administered during the second phase. In certain embodiments, the dose administered during the first phase is lower than the dose administered during the second phase to avoid undesired side effects. In certain embodiments, the undesired side effect is increased liver markers. In certain embodiments, the undesired side effect is increased ALT. In certain embodiments, the undesired side effect is increased AST. In certain embodiments, the undesired side effect is thrombocytopenia or neutropenia.
In certain embodiments, the dose administered during the first phase is higher than the dose administered during the second phase. In certain embodiments, the dose administered during the first phase is higher than the dose administered during the second phase to quickly achieve steady state reduction of STAT3 mRNA expression, STAT3 protein expression, and/or STAT3 activity. In certain embodiments, the dose administered during the first phase is higher than the dose administered during the second phase to avoid undesired side effects in the second phase. In certain embodiments, the undesired side effect is increased liver markers. In certain embodiments, the undesired side effect is increased ALT. In certain embodiments, the undesired side effect is increased AST. In certain embodiments, the undesired side effect is thrombocytopenia or neutropenia.
In certain embodiments where the first phase includes more than one dose, the doses administered during the first phase are all the same amount as one another. In certain embodiments, the doses administered during the first phase are not all the same amount. In certain embodiments, the doses given during the first phase increase over time. In certain embodiments, the doses given during the first phase decrease over time.
In certain embodiments, a first dose is administered by parenteral administration. In certain embodiments, the parenteral administration is subcutaneous administration. In certain embodiments, the parenteral administration is intravenous infusion.
The range of dosages capable of being administered during the “first phase” and/or “second phase” are the same as can be used for the “loading phase” and “maintenance phase” referred to above. In certain embodiments, dose, dose frequency, and duration of the first phase and/or second phase may be selected to achieve a desired effect. In certain embodiments, those variables are adjusted to result in a desired concentration of pharmaceutical agent in a subject. For example, in certain embodiments, dose and dose frequency are adjusted to provide plasma concentration of a pharmaceutical agent at an amount sufficient to achieve a desired effect. In certain embodiments, the plasma concentration is maintained above the minimal effective concentration (MEC). In certain embodiments, pharmaceutical compositions described herein are administered with a dosage regimen designed to maintain a concentration above the MEC for 10-90% of the time, between 30-90% of the time, or between 50-90% of the time. In certain embodiments, the pharmaceutical composition comprises an antisense oligonucleotide. In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464. In certain embodiments, doses, dose frequency, and duration of the first phase and/or second phase may be selected to achieve a desired plasma trough concentration of a pharmaceutical composition. In certain embodiments, the pharmaceutical composition comprises an antisense oligonucleotide. In certain embodiments, the antisense oligonucleotide has the nucleobase sequence of SEQ ID NO: 12. In certain embodiments, the antisense oligonucleotide is ISIS 481464. In certain embodiments, the desired plasma trough concentration is from 5-100 ng/mL. In certain embodiments, the desired plasma trough concentration is from 5-50 ng/mL. In certain embodiments, the desired plasma trough concentration is from 10-40 ng/mL. In certain embodiments, the desired plasma trough concentration is from 15-35 ng/mL. In certain embodiments, the desired plasma trough concentration is from 20-30 ng/mL.
In certain embodiments, dose, dose frequency, and duration of the first phase and/or second phase may be selected to achieve a desired effect within 1 to 26 weeks. In certain embodiments, the dose is the same and the dose frequency is varied to achieve the desired effect within 1 to 26 weeks. In certain embodiments, the dose increases over time and the dose frequency remains constant. In certain embodiments, one or more doses of the first phase are greater than one or more doses of the second phase. In certain embodiments, each of the first doses is greater than each of the second doses. In certain embodiments, it is desirable to achieve a desired effect as quickly as possible. In certain embodiments, a first phase with a high dose and/or high dose frequency may be desirable.
In certain embodiments, doses, dose frequency, and duration of the first phase and/or second phase may be selected to achieve an acceptable safety profile. For example, in certain embodiments, such variables may be selected to mitigate toxicity of the pharmaceutical composition. In certain embodiments, such variables are selected to mitigate liver toxicity. In certain embodiments, such variables are selected to mitigate renal toxicity. In certain embodiments, such variables are selected to mitigate thrombocytopenia or neutropenia.
In certain embodiments, doses increase over time. In certain embodiments, one or more doses of the first phase are lower than one or more doses of the second phase. In certain embodiments, a safety profile is not acceptable when ALT is 5-10 times the upper limit of normal. In certain embodiments, a safety profile is not acceptable when ALT is 5-10 times the upper limit of normal, and bilirubin is elevated two or more times the upper limit of normal. In certain embodiments, an acceptable safety profile comprises ALT elevations that are above three times the upper limit of normal, but do not exceed five times the upper limit of normal. In certain embodiments, an acceptable safety profile comprises ALT elevations that are above three times the upper limit of normal, but do not exceed five times the upper limit of normal, and bilirubin elevations that do not exceed two times the upper limit of normal. In certain embodiments, when administration of a pharmaceutical composition of the invention results in ALT elevations that are above three times the upper limit of normal, the dose and/or dose frequency is adjusted to mitigate the ALT elevation. In certain embodiments, the second phase includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more than 20 doses. In certain embodiments, the second phase lasts from one day to the lifetime of the subject. In certain embodiments, the second phase lasts 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, or 7 days as measured from administration of the last dose of the first phase to administration of the last dose of the second phase. In certain embodiments, the second phase lasts 1 week, 2 weeks, 3, weeks, 4, weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 11 weeks, 12 weeks, 13 weeks, 14 weeks, 15 weeks, 16 weeks, 17 weeks, 18 weeks, 19 weeks, 20 weeks, 21 weeks, 22 weeks, 23 weeks, 24 weeks, 25 weeks, 26 weeks, 27 weeks, 28 weeks, 29 weeks, 30 weeks, 31 weeks, 32 weeks, 33 weeks, 34 weeks, 35 weeks, 36 weeks, 37 weeks, 38 weeks, 39 weeks, 40 weeks, 41 weeks, 42 weeks, 43 weeks, 44 weeks, 45 weeks, 46 weeks, 47 weeks, 48 weeks, 49 weeks, 50 weeks, 51 weeks, or 52 weeks as measured from administration of the last dose of the first phase to administration of the last dose of the second phase. In certain embodiments, the second phase lasts 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, or 12 months as measured from administration of the last dose of the first phase to administration of the last dose of the second phase. In certain embodiments, the second phase lasts 1 year, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, 9 years, 10 years, 11 years, 12 years, 13 years, 14 years, 15 years, 16 years, 17 years, 18 years, 19 years, 20 years, 21 years, 22 years, 23 years, 24 years, 25 years, 26 years, 27 years, 28 years, 29 years, 30 years, 31 years, 32 years, 33 years, 34 years 35 years, 36 years, 37 years, 38 years, 39 years, 40 years, 41 years, 42 years, 43 years, 44 years, 45 years, 46 years, 47 years, 48 years, 49 years, or 50 years as measured from administration of the last dose of the first phase to administration of the last dose of the second phase. In certain embodiments, the second phase lasts as long as the dose continues to be needed, effective, and tolerated.
In certain embodiments where the second phase includes more than one dose, the doses administered during the second phase are all the same as one another. In certain embodiments, the doses administered during the second phase are not all the same. In certain embodiments, the doses increase over time. In certain embodiments, the doses decrease over time.
In certain embodiments, a second dose is administered by parenteral administration. In certain embodiments, the parenteral administration is subcutaneous administration. In certain embodiments, the parenteral administration is intravenous infusion.
Antisense Compounds
Oligomeric compounds include, but are not limited to, oligonucleotides, oligonucleosides, oligonucleotide analogs, oligonucleotide mimetics, antisense compounds, antisense oligonucleotides, and siRNAs. An oligomeric compound may be “antisense” to a target nucleic acid, meaning that is capable of undergoing hybridization to a target nucleic acid through hydrogen bonding.
In certain embodiments, an antisense compound has a nucleobase sequence that, when written in the 5′ to 3′ direction, comprises the reverse complement of the target segment of a target nucleic acid to which it is targeted. In certain such embodiments, an antisense oligonucleotide has a nucleobase sequence that, when written in the 5′ to 3′ direction, comprises the reverse complement of the target segment of a target nucleic acid to which it is targeted.
In certain embodiments, an antisense compound targeted to a STAT3 nucleic acid is 12 to 30 subunits in length. In certain embodiments, an antisense compound targeted to a STAT3 nucleic acid is 14 to 30 subunits in length. In certain embodiments, an antisense compound targeted to a STAT3 nucleic acid is 12 to 22 subunits in length. In other words, such antisense compounds are from 12 to 30 linked subunits, 14 to 30 linked subunits, or 12 to 22 linked subunits, respectively. In other embodiments, the antisense compound is 8 to 80, 12 to 50, 13 to 30, 13 to 50, 14 to 30, 14 to 50, 15 to 30, 15 to 50, 16 to 30, 16 to 50, 17 to 30, 17 to 50, 18 to 22, 18 to 24, 18 to 30, 18 to 50, 19 to 22, 19 to 30, 19 to 50, or 20 to 30 linked subunits. In certain such embodiments, the antisense compounds are 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 linked subunits in length, or a range defined by any two of the above values. In some embodiments, the antisense compound is an antisense oligonucleotide, and the linked subunits are nucleotides.
In certain embodiments, antisense oligonucleotides targeted to a STAT3 nucleic acid may be shortened or truncated. For example, a single subunit may be deleted from the 5′ end (5′ truncation), or alternatively from the 3′ end (3′ truncation). A shortened or truncated antisense compound targeted to a STAT3 nucleic acid may have two subunits deleted from the 5′ end, or alternatively may have two subunits deleted from the 3′ end, of the antisense compound. Alternatively, the deleted nucleosides may be dispersed throughout the antisense compound, for example, in an antisense compound having one nucleoside deleted from the 5′ end and one nucleoside deleted from the 3′ end.
When a single additional subunit is present in a lengthened antisense compound, the additional subunit may be located at the 5′ or 3′ end of the antisense compound. When two or more additional subunits are present, the added subunits may be adjacent to each other, for example, in an antisense compound having two subunits added to the 5′ end (5′ addition), or alternatively to the 3′ end (3′ addition), of the antisense compound. Alternatively, the added subunits may be dispersed throughout the antisense compound, for example, in an antisense compound having one subunit added to the 5′ end and one subunit added to the 3′ end.
It is possible to increase or decrease the length of an antisense compound, such as an antisense oligonucleotide, and/or introduce mismatch bases without eliminating activity. For example, in Woolf et al. (Proc. Natl. Acad. Sci. USA 89:7305-7309, 1992), a series of antisense oligonucleotides 13-25 nucleobases in length were tested for their ability to induce cleavage of a target RNA in an oocyte injection model. Antisense oligonucleotides 25 nucleobases in length with 8 or 11 mismatch bases near the ends of the antisense oligonucleotides were able to direct specific cleavage of the target mRNA, albeit to a lesser extent than the antisense oligonucleotides that contained no mismatches. Similarly, target specific cleavage was achieved using 13 nucleobase antisense oligonucleotides, including those with 1 or 3 mismatches.
Gautschi et al. ( J. Natl. Cancer Inst. 93:463-471, March 2001) demonstrated the ability of an oligonucleotide having 100% complementarity to the bcl-2 mRNA and having 3 mismatches to the bcl-xL mRNA to reduce the expression of both bcl-2 and bcl-xL in vitro and in vivo. Furthermore, this oligonucleotide demonstrated potent anti-tumor activity in vivo.
Maher and Dolnick ( Nuc. Acid. Res. 16:3341-3358, 1988) tested a series of tandem 14 nucleobase antisense oligonucleotides, and a 28 and 42 nucleobase antisense oligonucleotides comprised of the sequence of two or three of the tandem antisense oligonucleotides, respectively, for their ability to arrest translation of human DHFR in a rabbit reticulocyte assay. Each of the three 14 nucleobase antisense oligonucleotides alone was able to inhibit translation, albeit at a more modest level than the 28 or 42 nucleobase antisense oligonucleotides.
Antisense Compound Motifs
In certain embodiments, antisense compounds targeted to a STAT3 nucleic acid have chemically modified subunits arranged in patterns, or motifs, to confer to the antisense compounds properties such as enhanced inhibitory activity, increased binding affinity for a target nucleic acid, or resistance to degradation by in vivo nucleases.
Chimeric antisense compounds typically contain at least one region modified so as to confer increased resistance to nuclease degradation, increased cellular uptake, increased binding affinity for the target nucleic acid, and/or increased inhibitory activity. A second region of a chimeric antisense compound may optionally serve as a substrate for the cellular endonuclease RNase H, which cleaves the RNA strand of an RNA:DNA duplex.
Antisense compounds having a gapmer motif are considered chimeric antisense compounds. In a gapmer an internal region having a plurality of nucleotides that supports RNaseH cleavage is positioned between external regions having a plurality of nucleotides that are chemically distinct from the nucleosides of the internal region. In the case of an antisense oligonucleotide having a gapmer motif, the gap segment generally serves as the substrate for endonuclease cleavage, while the wing segments comprise modified nucleosides. In certain embodiments, the regions of a gapmer are differentiated by the types of sugar moieties comprising each distinct region. The types of sugar moieties that are used to differentiate the regions of a gapmer may in some embodiments include β-D-ribonucleosides, β-D-deoxyribonucleosides, 2′-modified nucleosides (such 2′-modified nucleosides may include 2′-MOE and 2′-O—CH 3 , among others), and bicyclic sugar modified nucleosides (such bicyclic sugar modified nucleosides may include those having a constrained ethyl). In certain embodiments, wings may include several modified sugar moieties, including, for example 2′-MOE and constrained ethyl. In certain embodiments, wings may include several modified and unmodified sugar moieties. In certain embodiments, wings may include various combinations of 2′-MOE nucleosides, constrained ethyl nucleosides, and 2′-deoxynucleosides.
Each distinct region may comprise uniform sugar moieties, variants, or alternating sugar moieties. The wing-gap-wing motif is frequently described as “X-Y-Z”, where “X” represents the length of the 5′-wing, “Y” represents the length of the gap, and “Z” represents the length of the 3′-wing. “X” and “Z” may comprise uniform, variant, or alternating sugar moieties. In certain embodiments, “X” and “Y” may include one or more 2′-deoxynucleosides. “Y” may comprise 2′-deoxynucleosides. As used herein, a gapmer described as “X-Y-Z” has a configuration such that the gap is positioned immediately adjacent to each of the 5′-wing and the 3′ wing. Thus, no intervening nucleotides exist between the 5′-wing and gap, or the gap and the 3′-wing. Any of the antisense compounds described herein can have a gapmer motif. In certain embodiments, “X” and “Z” are the same, in other embodiments they are different. In certain embodiments, “Y” is between 8 and 15 nucleosides. X, Y, or Z can be any of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30 or more nucleosides.
In certain embodiments, gapmers provided herein include, for example, 11-mers having a motif of 1-9-1.
In certain embodiments, gapmers provided herein include, for example, 12-mers having a motif of 1-9-2, 2-9-1, or 1-10-1.
In certain embodiments, gapmers provided herein include, for example, 13-mers having a motif of 1-9-3, 2-9-2, 3-9-1, 1-10-2, or 2-10-1.
In certain embodiments, gapmers provided herein include, for example, 14-mers having a motif of 1-9-4, 2-9-3, 3-9-2, 4-9-1, 1-10-3, 2-10-2, or 3-10-1.
In certain embodiments, gapmers provided herein include, for example, 15-mers having a motif of 1-9-5, 2-9-4, 3-9-3, 4-9-2, 5-9-1, 1-10-4, 2-10-3, 3-10-2, or 4-10-1.
In certain embodiments, gapmers provided herein include, for example, 16-mers having a motif of 2-9-5, 3-9-4, 4-9-3, 5-9-2, 1-10-5, 2-10-4, 3-10-3, 4-10-2, or 5-10-1.
In certain embodiments, gapmers provided herein include, for example, 17-mers having a motif of 3-9-5, 4-9-4, 5-9-3, 2-10-5, 3-10-4, 4-10-3, or 5-10-2.
In certain embodiments, gapmers provided herein include, for example, 18-mers having a motif of 4-9-5, 5-9-4, 3-10-5, 4-10-4, or 5-10-3.
In certain embodiments, gapmers provided herein include, for example, 19-mers having a motif of 5-9-5, 4-10-5, or 5-10-4.
In certain embodiments, gapmers provided herein include, for example, 20-mers having a motif of 5-10-5.
In certain embodiments, the antisense compound has a “wingmer” motif, having a wing-gap or gap-wing configuration, i.e. an X-Y or Y—Z configuration as described above for the gapmer configuration. Thus, wingmer configurations provided herein include, but are not limited to, for example 5-10, 8-4, 4-12, 12-4, 3-14, 16-2, 18-1, 10-3, 2-10, 1-10, 8-2, 2-13, 5-13, 5-8, or 6-8.
In certain embodiments, antisense compound targeted to a STAT3 nucleic acid has a 2-10-2 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a 3-10-3 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a 5-10-5 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a 1-10-5 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a 3-10-4 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a 2-10-4 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a 4-9-3 gapmer motif.
In certain embodiments, the antisense compound targeted to a STAT3 nucleic acid has a gap-widened motif.
In certain embodiments, the antisense compounds targeted to a STAT3 nucleic acid has any of the following sugar motifs:
k-d(10)-k e-d(10)-k k-d(10)-e k-k-d(10)-k-k k-k-d(10)-e-e e-e-d(10)-k-k k-k-k-d(10)-k-k-k e-e-e-d(10)-k-k-k k-k-k-d(10)-c-c-c k-k-k-d(10)-k-k-k e-k-k-d(10)-k-k-e e-e-k-d(10)-k-k-e e-d-k-d(10)-k-k-e e-k-d(10)-k-e-k-e k-d(10)-k-e-k-e-e e-e-k-d(10)-k-e-k-e e-d-d-k-d(9)-k-k-e e-e-e-e-d(9)-k-k-e
wherein, k is a constrained ethyl nucleoside, e is a 2′-MOE substituted nucleoside, and d is a 2′-deoxynucleoside.
In certain embodiments, the antisense oligonucleotide has a sugar motif described by Formula A as follows: (J) m -(B) n -(J) p -(B) r -(A) t -(D) g -(A) v -(B) w -(J) x -(B) y -(J) z
wherein:
each A is independently a 2′-substituted nucleoside; each B is independently a bicyclic nucleoside; each J is independently either a 2′-substituted nucleoside or a 2′-deoxynucleoside; each D is a 2′-deoxynucleoside; m is 0-4; n is 0-2; p is 0-2; r is 0-2; t is 0-2; v is 0-2; w is 0-4; x is 0-2; y is 0-2; z is 0-4; g is 6-14;
provided that:
at least one of m, n, and r is other than 0; at least one of w and y is other than 0; the sum of m, n, p, r, and t is from 2 to 5; and the sum of v, w, x, y, and z is from 2 to 5.
Target Nucleic Acids, Target Regions and Nucleotide Sequences
Nucleotide sequences that encode STAT3 include, without limitation, the following: GENBANK Accession No. NM_139276.2 (incorporated herein as SEQ ID NO: 1) and the complement of GENBANK Accession No. NT_010755.14 truncated from nucleotides 4185000 to U.S. Pat. No. 4,264,000 (incorporated herein as SEQ ID NO: 2).
It is understood that the sequence set forth in each SEQ ID NO contained herein is independent of any modification to a sugar moiety, an internucleoside linkage, or a nucleobase. As such, antisense compounds defined by a SEQ ID NO may comprise, independently, one or more modifications to a sugar moiety, an internucleoside linkage, or a nucleobase. Antisense compounds described by Isis Number (Isis No) indicate a combination of nucleobase sequence and motif.
In certain embodiments, a target region is a structurally defined region of the target nucleic acid. For example, a target region may encompass a 3′ UTR, a 5′ UTR, an exon, an intron, an exon/intron junction, a coding region, a translation initiation region, translation termination region, or other defined nucleic acid region. The structurally defined regions for STAT3 can be obtained by accession number from sequence databases such as NCBI and such information is incorporated herein by reference. In certain embodiments, a target region may encompass the sequence from a 5′ target site of one target segment within the target region to a 3′ target site of another target segment within the same target region.
Targeting includes determination of at least one target segment to which an antisense compound hybridizes, such that a desired effect occurs. In certain embodiments, the desired effect is a reduction in mRNA target nucleic acid levels. In certain embodiments, the desired effect is reduction of levels of protein encoded by the target nucleic acid or a phenotypic change associated with the target nucleic acid.
A target region may contain one or more target segments. Multiple target segments within a target region may be overlapping. Alternatively, they may be non-overlapping. In certain embodiments, target segments within a target region are separated by no more than about 300 nucleotides. In certain embodiments, target segments within a target region are separated by a number of nucleotides that is, is about, is no more than, is no more than about, 250, 200, 150, 100, 90, 80, 70, 60, 50, 40, 30, 20, or 10 nucleotides on the target nucleic acid, or is a range defined by any two of the preceeding values. In certain embodiments, target segments within a target region are separated by no more than, or no more than about, 5 nucleotides on the target nucleic acid. In certain embodiments, target segments are contiguous. Contemplated are target regions defined by a range having a starting nucleic acid that is any of the 5′ target sites or 3′ target sites listed herein.
Suitable target segments may be found within a 5′ UTR, a coding region, a 3′ UTR, an intron, an exon, or an exon/intron junction. Target segments containing a start codon or a stop codon are also suitable target segments. A suitable target segment may specifically exclude a certain structurally defined region such as the start codon or stop codon.
The determination of suitable target segments may include a comparison of the sequence of a target nucleic acid to other sequences throughout the genome. For example, the BLAST algorithm may be used to identify regions of similarity amongst different nucleic acids. This comparison can prevent the selection of antisense compound sequences that may hybridize in a non-specific manner to sequences other than a selected target nucleic acid (i.e., non-target or off-target sequences).
There may be variation in activity (e.g., as defined by percent reduction of target nucleic acid levels) of the antisense compounds within an active target region. In certain embodiments, reductions in STAT3 mRNA levels are indicative of inhibition of STAT3 expression. Reductions in levels of a STAT3 protein are also indicative of inhibition of target mRNA expression. Further, phenotypic changes are indicative of inhibition of STAT3 expression. In certain embodiments, reduced cellular growth, reduced tumor growth, and reduced tumor volume can be indicative of inhibition of STAT3 expression. In certain embodiments, amelioration of symptoms associated with cancer can be indicative of inhibition of STAT3 expression. In certain embodiments, reduction of cachexia is indicative of inhibition of STAT3 expression. In certain embodiments, reduction of cancer markers can be indicative of inhibition of STAT3 expression.
Hybridization
In some embodiments, hybridization occurs between an antisense compound disclosed herein and a STAT3 nucleic acid. The most common mechanism of hybridization involves hydrogen bonding (e.g., Watson-Crick, Hoogsteen or reversed Hoogsteen hydrogen bonding) between complementary nucleobases of the nucleic acid molecules.
Hybridization can occur under varying conditions. Stringent conditions are sequence-dependent and are determined by the nature and composition of the nucleic acid molecules to be hybridized.
Methods of determining whether a sequence is specifically hybridizable to a target nucleic acid are well known in the art. In certain embodiments, the antisense compounds provided herein are specifically hybridizable with a STAT3 nucleic acid.
Complementarity
An antisense compound and a target nucleic acid are complementary to each other when a sufficient number of nucleobases of the antisense compound can hydrogen bond with the corresponding nucleobases of the target nucleic acid, such that a desired effect will occur (e.g., antisense inhibition of a target nucleic acid, such as a STAT3 nucleic acid).
Non-complementary nucleobases between an antisense compound and a STAT3 nucleic acid may be tolerated provided that the antisense compound remains able to specifically hybridize to a target nucleic acid. Moreover, an antisense compound may hybridize over one or more segments of a STAT3 nucleic acid such that intervening or adjacent segments are not involved in the hybridization event (e.g., a loop structure, mismatch or hairpin structure).
In certain embodiments, the antisense compounds provided herein, or a specified portion thereof, are, or are at least, 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% complementary to a STAT3 nucleic acid, a target region, target segment, or specified portion thereof. Percent complementarity of an antisense compound with a target nucleic acid can be determined using routine methods.
For example, an antisense compound in which 18 of 20 nucleobases of the antisense compound are complementary to a target region, and would therefore specifically hybridize, would represent 90 percent complementarity. In this example, the remaining noncomplementary nucleobases may be clustered or interspersed with complementary nucleobases and need not be contiguous to each other or to complementary nucleobases. As such, an antisense compound which is 18 nucleobases in length having four noncomplementary nucleobases which are flanked by two regions of complete complementarity with the target nucleic acid would have 77.8% overall complementarity with the target nucleic acid and would thus fall within the scope of the present invention. Percent complementarity of an antisense compound with a region of a target nucleic acid can be determined routinely using BLAST programs (basic local alignment search tools) and PowerBLAST programs known in the art (Altschul et al., J. Mol. Biol., 1990, 215, 403 410; Zhang and Madden, Genome Res., 1997, 7, 649 656). Percent homology, sequence identity or complementarity, can be determined by, for example, the Gap program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, Madison Wis.), using default settings, which uses the algorithm of Smith and Waterman (Adv. Appl. Math., 1981, 2, 482 489).
In certain embodiments, the antisense compounds provided herein, or specified portions thereof, are fully complementary (i.e. 100% complementary) to a target nucleic acid, or specified portion thereof. For example, an antisense compound may be fully complementary to a STAT3 nucleic acid, or a target region, or a target segment or target sequence thereof. As used herein, “fully complementary” means each nucleobase of an antisense compound is capable of precise base pairing with the corresponding nucleobases of a target nucleic acid. For example, a 20 nucleobase antisense compound is fully complementary to a target sequence that is 400 nucleobases long, so long as there is a corresponding 20 nucleobase portion of the target nucleic acid that is fully complementary to the antisense compound. Fully complementary can also be used in reference to a specified portion of the first and/or the second nucleic acid. For example, a 20 nucleobase portion of a 30 nucleobase antisense compound can be “fully complementary” to a target sequence that is 400 nucleobases long. The 20 nucleobase portion of the 30 nucleobase oligonucleotide is fully complementary to the target sequence if the target sequence has a corresponding 20 nucleobase portion wherein each nucleobase is complementary to the 20 nucleobase portion of the antisense compound. At the same time, the entire 30 nucleobase antisense compound may or may not be fully complementary to the target sequence, depending on whether the remaining 10 nucleobases of the antisense compound are also complementary to the target sequence.
The location of a non-complementary nucleobase may be at the 5′ end or 3′ end of the antisense compound. Alternatively, the non-complementary nucleobase or nucleobases may be at an internal position of the antisense compound. When two or more non-complementary nucleobases are present, they may be contiguous (i.e. linked) or non-contiguous. In one embodiment, a non-complementary nucleobase is located in the wing segment of a gapmer antisense oligonucleotide.
In certain embodiments, antisense compounds that are, or are up to 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleobases in length comprise no more than 4, no more than 3, no more than 2, or no more than 1 non-complementary nucleobase(s) relative to a target nucleic acid, such as a STAT3 nucleic acid, or specified portion thereof.
In certain embodiments, antisense compounds that are, or are up to 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleobases in length comprise no more than 6, no more than 5, no more than 4, no more than 3, no more than 2, or no more than 1 non-complementary nucleobase(s) relative to a target nucleic acid, such as a STAT3 nucleic acid, or specified portion thereof.
The antisense compounds provided herein also include those which are complementary to a portion of a target nucleic acid. As used herein, “portion” refers to a defined number of contiguous (i.e. linked) nucleobases within a region or segment of a target nucleic acid. A “portion” can also refer to a defined number of contiguous nucleobases of an antisense compound. In certain embodiments, the antisense compounds, are complementary to at least an 8 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 9 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 10 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least an 11 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 12 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 13 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 14 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 15 nucleobase portion of a target segment. Also contemplated are antisense compounds that are complementary to at least a 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more nucleobase portion of a target segment, or a range defined by any two of these values.
Identity
The antisense compounds provided herein may also have a defined percent identity to a particular nucleotide sequence, SEQ ID NO, or compound represented by a specific Isis number, or portion thereof. As used herein, an antisense compound is identical to the sequence disclosed herein if it has the same nucleobase pairing ability. For example, a RNA which contains uracil in place of thymidine in a disclosed DNA sequence would be considered identical to the DNA sequence since both uracil and thymidine pair with adenine. Shortened and lengthened versions of the antisense compounds described herein as well as compounds having non-identical bases relative to the antisense compounds provided herein also are contemplated. The non-identical bases may be adjacent to each other or dispersed throughout the antisense compound. Percent identity of an antisense compound is calculated according to the number of bases that have identical base pairing relative to the sequence to which it is being compared.
In certain embodiments, the antisense compounds, or portions thereof, are at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to one or more of the antisense compounds or SEQ ID NOs, or a portion thereof, disclosed herein.
In certain embodiments, a portion of the antisense compound is compared to an equal length portion of the target nucleic acid. In certain embodiments, an 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 nucleobase portion is compared to an equal length portion of the target nucleic acid.
In certain embodiments, a portion of the antisense oligonucleotide is compared to an equal length portion of the target nucleic acid. In certain embodiments, an 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 nucleobase portion is compared to an equal length portion of the target nucleic acid.
Modifications
A nucleoside is a base-sugar combination. The nucleobase (also known as base) portion of the nucleoside is normally a heterocyclic base moiety. Nucleotides are nucleosides that further include a phosphate group covalently linked to the sugar portion of the nucleoside. For those nucleosides that include a pentofuranosyl sugar, the phosphate group can be linked to the 2′, 3′ or 5′ hydroxyl moiety of the sugar. Oligonucleotides are formed through the covalent linkage of adjacent nucleosides to one another, to form a linear polymeric oligonucleotide. Within the oligonucleotide structure, the phosphate groups are commonly referred to as forming the internucleoside linkages of the oligonucleotide.
Modifications to antisense compounds encompass substitutions or changes to internucleoside linkages, sugar moieties, or nucleobases. Modified antisense compounds are often preferred over native forms because of desirable properties such as, for example, enhanced cellular uptake, enhanced affinity for nucleic acid target, increased stability in the presence of nucleases, or increased inhibitory activity.
Chemically modified nucleosides may also be employed to increase the binding affinity of a shortened or truncated antisense oligonucleotide for its target nucleic acid. Consequently, comparable results can often be obtained with shorter antisense compounds that have such chemically modified nucleosides.
Modified Internucleoside Linkages
The naturally occurring internucleoside linkage of RNA and DNA is a 3′ to 5′ phosphodiester linkage. Antisense compounds having one or more modified, i.e. non-naturally occurring, internucleoside linkages are often selected over antisense compounds having naturally occurring internucleoside linkages because of desirable properties such as, for example, enhanced cellular uptake, enhanced affinity for target nucleic acids, and increased stability in the presence of nucleases.
Oligonucleotides having modified internucleoside linkages include internucleoside linkages that retain a phosphorus atom as well as internucleoside linkages that do not have a phosphorus atom. Representative phosphorus containing internucleoside linkages include, but are not limited to, phosphodiesters, phosphotriesters, methylphosphonates, phosphoramidate, and phosphorothioates. Methods of preparation of phosphorous-containing and non-phosphorous-containing linkages are well known.
In certain embodiments, antisense compounds targeted to a STAT3 nucleic acid comprise one or more modified internucleoside linkages. In certain embodiments, the modified internucleoside linkages are phosphorothioate linkages. In certain embodiments, each internucleoside linkage of an antisense compound is a phosphorothioate internucleoside linkage.
Modified Sugar Moieties
Antisense compounds provided herein can optionally contain one or more nucleosides wherein the sugar group has been modified. Such sugar modified nucleosides may impart enhanced nuclease stability, increased binding affinity, or some other beneficial biological property to the antisense compounds. In certain embodiments, nucleosides comprise a chemically modified ribofuranose ring moiety. Examples of chemically modified ribofuranose rings include, without limitation, addition of substitutent groups (including 5′ and 2′ substituent groups); bridging of non-geminal ring atoms to form bicyclic nucleic acids (BNA); replacement of the ribosyl ring oxygen atom with S, N(R), or C(R1)(R)2 (R═H, C 1 -C 12 alkyl or a protecting group); and combinations thereof. Examples of chemically modified sugars include, 2′-F-5′-methyl substituted nucleoside (see, PCT International Application WO 2008/101157, published on Aug. 21, 2008 for other disclosed 5′, 2′-bis substituted nucleosides), replacement of the ribosyl ring oxygen atom with S with further substitution at the 2′-position (see, published U.S. Patent Application US2005/0130923, published on Jun. 16, 2005), or, alternatively, 5′-substitution of a BNA (see, PCT International Application WO 2007/134181, published on Nov. 22, 2007, wherein LNA is substituted with, for example, a 5′-methyl or a 5′-vinyl group).
Examples of nucleosides having modified sugar moieties include, without limitation, nucleosides comprising 5′-vinyl, 5′-methyl (R or S), 4′-S, 2′-F, 2′-OCH 3 , and 2′-O(CH 2 )2OCH 3 substituent groups. The substituent at the 2′ position can also be selected from allyl, amino, azido, thio, O-allyl, O—C 1 -C 10 alkyl, OCF 3 , O(CH 2 )2SCH 3 , O(CH 2 )2-O—N(Rm)(Rn), and O—CH 2 —C(═O)—N(Rm)(Rn), where each Rm and Rn is, independently, H or substituted or unsubstituted C 1 -C 10 alkyl.
As used herein, “bicyclic nucleosides” refer to modified nucleosides comprising a bicyclic sugar moiety. Examples of bicyclic nucleosides include, without limitation, nucleosides comprising a bridge between the 4′ and the 2′ ribosyl ring atoms. In certain embodiments, antisense compounds provided herein include one or more bicyclic nucleosides wherein the bridge comprises a 4′ to 2′ bicyclic nucleoside. Examples of such 4′ to 2′ bicyclic nucleosides, include, but are not limited to, one of the formulae: 4′-(CH 2 )—O-2′ (LNA); 4′-(CH 2 )—S-2; 4′-(CH 2 ) 2 —O-2′ (ENA); 4′-CH(CH 3 )—O-2′ and 4′-C—H(CH 2 OCH 3 )—O-2′, and analogs thereof (see, U.S. Pat. No. 7,399,845, issued on Jul. 15, 2008); 4′-C(CH 3 )(CH 3 )—O-2′, and analogs thereof (see, published PCT International Application WO2009/006478, published Jan. 8, 2009); 4′-CH 2 —N(OCH 3 )-2′, and analogs thereof (see, published PCT International Application WO2008/150729, published Dec. 11, 2008); 4′-CH 2 —O—N(CH 3 )-2′ (see, published U.S. Patent Application US2004/0171570, published Sep. 2, 2004); 4′-CH 2 —N(R)—O-2′, wherein R is H, C 1 -C 12 alkyl, or a protecting group (see, U.S. Pat. No. 7,427,672, issued on Sep. 23, 2008); 4′-CH 2 —C(H)(CH 3 )-2′ (see, Chattopadhyaya, et al., J. Org. Chem., 2009, 74, 118-134); and 4′-CH 2 —C(═CH 2 )-2′, and analogs thereof (see, published PCT International Application WO 2008/154401, published on Dec. 8, 2008). Also see, for example: Singh et al., Chem. Commun., 1998, 4, 455-456; Koshkin et al., Tetrahedron, 1998, 54, 3607-3630; Wahlestedt et al., Proc. Natl. Acad. Sci. U.S.A, 2000, 97, 5633-5638; Kumar et al., Bioorg. Med. Chem. Lett., 1998, 8, 2219-2222; Singh et al., J. Org. Chem., 1998, 63, 10035-10039; Srivastava et al., J. Am. Chem. Soc., 129(26) 8362-8379 (Jul. 4, 2007); Elayadi et al., Curr. Opinion Invens. Drugs, 2001, 2, 558-561; Braasch et al., Chem. Biol., 2001, 8, 1-7; Orum et al., Curr. Opinion Mol. Ther., 2001, 3, 239-243; U.S. Pat. Nos. 6,670,461, 7,053,207, 6,268,490, 6,770,748, 6,794,499, 7,034,133, 6,525,191, 7,399,845; published PCT International applications WO 2004/106356, WO 94/14226, WO 2005/021570, and WO 2007/134181; U.S. Patent Publication Nos. US2004/0171570, US2007/0287831, and US2008/0039618; and U.S. patent Ser. Nos. 12/129,154, 60/989,574, 61/026,995, 61/026,998, 61/056,564, 61/086,231, 61/097,787, and 61/099,844; and PCT International Application Nos. PCT/US2008/064591, PCT/US2008/066154, and PCT/US2008/068922. Each of the foregoing bicyclic nucleosides can be prepared having one or more stereochemical sugar configurations including for example α-L-ribofuranose and β-D-ribofuranose (see PCT international application PCT/DK98/00393, published on Mar. 25, 1999 as WO 99/14226).
In certain embodiments, bicyclic sugar moieties of BNA nucleosides include, but are not limited to, compounds having at least one bridge between the 4′ and the 2′ position of the pentofuranosyl sugar moiety wherein such bridges independently comprises 1 or from 2 to 4 linked groups independently selected from —[C(R a )(R b )] n —, —C(R a )═C(R b )—, —C(R a )═N—, —C(═NR a )—, —C(═O)—, —C(═S)—, —O—, —Si(R a ) 2 —, —S(═O) x —, and —N(R a )—;
wherein:
x is 0, 1, or 2;
n is 1, 2, 3, or 4;
each R a and R b is, independently, H, a protecting group, hydroxyl, C 1 -C 12 alkyl, substituted C 1 -C 12 alkyl, C 2 -C 12 alkenyl, substituted C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, substituted C 2 -C 12 alkynyl, C 5 -C 20 aryl, substituted C 5 -C 20 aryl, heterocycle radical, substituted heterocycle radical, heteroaryl, substituted heteroaryl, C 5 -C 7 alicyclic radical, substituted C 5 -C 7 alicyclic radical, halogen, OJ 1 , NJ 1 J 2 , SJ 1 , N 3 , COOJ 1 , acyl (C(═O)—H), substituted acyl, CN, sulfonyl (S(═O) 2 -J 1 ), or sulfoxyl (S(═O)-J 1 ); and
each J 1 and J 2 is, independently, H, C 1 -C 12 alkyl, substituted C 1 -C 12 alkyl, C 2 -C 12 alkenyl, substituted C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, substituted C 2 -C 12 alkynyl, C 5 -C 20 aryl, substituted C 5 -C 20 aryl, acyl (C(═O)—H), substituted acyl, a heterocycle radical, a substituted heterocycle radical, C 1 -C 12 aminoalkyl, substituted C 1 -C 12 aminoalkyl, or a protecting group.
In certain embodiments, the bridge of a bicyclic sugar moiety is, —[C(R a )(R b )] n —, —[C(R a )(R b )] n —O—, —C(R a R b )—N(R)—O— or, —C(R a R b )—O—N(R)—. In certain embodiments, the bridge is 4′-CH 2 -2′, 4′-(CH 2 ) 2 -2′, 4′-(CH 2 ) 3 -2′, 4′-(CH 2 ) 2 —O-2′, 4′-CH 2 —O—N(R)-2′, and 4′-CH 2 —N(R)—O-2′-, wherein each R is, independently, H, a protecting group, or C 1 -C 12 alkyl.
In certain embodiments, bicyclic nucleosides are further defined by isomeric configuration. For example, a nucleoside comprising a 4′-2′ methylene-oxy bridge, may be in the α-L configuration or in the β-D configuration. Previously, α-L-methyleneoxy (4′-CH 2 —O-2′) BNA's have been incorporated into antisense oligonucleotides that showed antisense activity (Frieden et al., Nucleic Acids Research, 2003, 21, 6365-6372).
In certain embodiments, bicyclic nucleosides include, but are not limited to, (A) α-L-Methyleneoxy (4′-CH 2 —O-2′) BNA, (B) β-D-Methyleneoxy (4′-CH 2 —O-2′) BNA, (C) Ethyleneoxy (4′-(CH 2 ) 2 —O-2′) BNA, (D) Aminooxy (4′-CH 2 —O—N(R)-2′) BNA, (E) Oxyamino (4′-CH 2 —N(R)—O-2′) BNA, (F) Methyl(methyleneoxy) (4′-CH(CH 3 )—O-2′) BNA, (G) methylene-thio (4′-CH 2 —S-2′) BNA, (H) methylene-amino (4′-CH2-N(R)-2′) BNA, (I) methyl carbocyclic (4′-CH 2 —CH(CH 3 )-2′) BNA, and (J) propylene carbocyclic (4′-(CH 2 ) 3 -2′) BNA as depicted below.
wherein Bx is the base moiety and R is, independently, H, a protecting group or C 1 -C 12 alkyl.
In certain embodiments, bicyclic nucleoside having Formula I:
wherein:
Bx is a heterocyclic base moiety;
-Q a -Q b -Q c - is —CH 2 —N(R c )—CH 2 —, —C(═O)—N(R c )—CH 2 —, —CH 2 —O—N(R c )—, —CH 2 —N(R c )—O—, or —N(R c )—O—CH 2 ;
R c , is C 1 -C 12 alkyl or an amino protecting group; and
T a and T b are each, independently, H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety, or a covalent attachment to a support medium.
In certain embodiments, bicyclic nucleoside having Formula II:
wherein:
Bx is a heterocyclic base moiety;
T a and T b are each, independently, H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety, or a covalent attachment to a support medium;
Z a is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, substituted C 1 -C 6 alkyl, substituted C 2 -C 6 alkenyl, substituted C 2 -C 6 alkynyl, acyl, substituted acyl, substituted amide, thiol, or substituted thio.
In one embodiment, each of the substituted groups is, independently, mono or poly substituted with substituent groups independently selected from halogen, oxo, hydroxyl, OJ c , NJ c J d , SJ c , N 3 , OC(═X)J c , and NJ e C(═X)NJ c J d , wherein each J c , J d , and J e is, independently, H, C 1 -C 6 alkyl, or substituted C 1 -C 6 alkyl and X is O or NJ c .
In certain embodiments, bicyclic nucleoside having Formula III:
wherein:
Bx is a heterocyclic base moiety;
T a and T b are each, independently, H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety, or a covalent attachment to a support medium;
Z b is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, substituted C 1 -C 6 alkyl, substituted C 2 -C 6 alkenyl, substituted C 2 -C 6 alkynyl, or substituted acyl (C(═O)—).
In certain embodiments, bicyclic nucleoside having Formula IV:
wherein:
Bx is a heterocyclic base moiety;
T a and T b are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety, or a covalent attachment to a support medium;
R d is C 1 -C 6 alkyl, substituted C 1 -C 6 alkyl, C 2 -C 6 alkenyl, substituted C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, or substituted C 2 -C 6 alkynyl;
each q a , q b , q c and q d is, independently, H, halogen, C 1 -C 6 alkyl, substituted C 1 -C 6 alkyl, C 2 -C 6 alkenyl, substituted C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, or substituted C 2 -C 6 alkynyl, C 1 -C 6 alkoxyl, substituted C 1 -C 6 alkoxyl, acyl, substituted acyl, C 1 -C 6 aminoalkyl, or substituted C 1 -C 6 aminoalkyl;
In certain embodiments, bicyclic nucleoside having Formula V:
wherein:
Bx is a heterocyclic base moiety;
T a and T b are each, independently, H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety, or a covalent attachment to a support medium;
q a , q b , q c and q f are each, independently, hydrogen, halogen, C 1 -C 12 alkyl, substituted C 1 -C 12 alkyl, C 2 -C 12 alkenyl, substituted C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, substituted C 2 -C 12 alkynyl, C 1 -C 12 alkoxy, substituted C 1 -C 12 alkoxy, OJ j , SJ j , SOJ j , SO 2 J j , NJ j J k , N 3 , CN, C(═O)OJ j , C(═O)NJ j J k , C(═O)J j , O—C(═O)NJ j J k , N(H)C(═NH)NJ j J k , N(H)C(═O)NJ j J k or N(H)C(═S)NJ j J k ;
or q e and q f together are ═C(q g )(q h );
q g and q h are each, independently, H, halogen, C 1 -C 12 alkyl, or substituted C 1 -C 12 alkyl.
The synthesis and preparation of the methyleneoxy (4′-CH 2 —O-2′) BNA monomers adenine, cytosine, guanine, 5-methyl-cytosine, thymine, and uracil, along with their oligomerization, and nucleic acid recognition properties have been described (see, e.g., Koshkin et al., Tetrahedron, 1998, 54, 3607-3630). BNAs and preparation thereof are also described in WO 98/39352 and WO 99/14226.
Analogs of methyleneoxy (4′-CH 2 —O-2′) BNA, methyleneoxy (4′-CH 2 —O-2′) BNA, and 2′-thio-BNAs, have also been prepared (see, e.g., Kumar et al., Bioorg. Med. Chem. Lett., 1998, 8, 2219-2222). Preparation of locked nucleoside analogs comprising oligodeoxyribonucleotide duplexes as substrates for nucleic acid polymerases has also been described (see, e.g., Wengel et al., WO 99/14226). Furthermore, synthesis of 2′-amino-BNA, a novel conformationally restricted high-affinity oligonucleotide analog, has been described in the art (see, e.g., Singh et al., J. Org. Chem., 1998, 63, 10035-10039). In addition, 2′-amino- and 2′-methylamino-BNA's have been prepared and the thermal stability of their duplexes with complementary RNA and DNA strands has been previously reported.
In certain embodiments, bicyclic nucleoside having Formula VI:
wherein:
Bx is a heterocyclic base moiety;
T a and T b are each, independently, H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety, or a covalent attachment to a support medium;
each q i , q j , q k and q l is, independently, H, halogen, C 1 -C 12 alkyl, substituted C 1 -C 12 alkyl, C 2 -C 12 alkenyl, substituted C 2 -C 12 alkenyl, C 2 -C 12 alkynyl, substituted C 2 -C 12 alkynyl, C 1 -C 12 alkoxyl, substituted C 1 -C 12 alkoxyl, OJ j , SJ j , SOJ j , SO 2 J j , NJ j J k , N 3 , CN, C(═O)OJ j , C(═O)NJ j J k , C(═O)J j , O—C(═O)NJ j J k , N(H)C(═NH)NJ j J k , N(H)C(═O)NJ j J k , or N(H)C(═S)NJ j J k ; and
q i and q j or q l and q k together are ═C(q g )(q h ), wherein q g and q h are each, independently, H, halogen, C 1 -C 12 alkyl, or substituted C 1 -C 12 alkyl.
One carbocyclic bicyclic nucleoside having a 4′-(CH 2 ) 3 -2′ bridge and the alkenyl analog, bridge 4′-CH═CH—CH 2 -2′, have been described (see, e.g., Freier et al., Nucleic Acids Research, 1997, 25(22), 4429-4443 and Albaek et al., J. Org. Chem., 2006, 71, 7731-7740). The synthesis and preparation of carbocyclic bicyclic nucleosides along with their oligomerization and biochemical studies have also been described (see, e.g., Srivastava et al., J. Am. Chem. Soc. 2007, 129(26), 8362-8379).
As used herein, “4′-2′ bicyclic nucleoside” or “4′ to 2′ bicyclic nucleoside” refers to a bicyclic nucleoside comprising a furanose ring comprising a bridge connecting the 2′ carbon atom and the 4′ carbon atom.
As used herein, “monocyclic nucleosides” refer to nucleosides comprising modified sugar moieties that are not bicyclic sugar moieties. In certain embodiments, the sugar moiety, or sugar moiety analogue, of a nucleoside may be modified or substituted at any position.
As used herein, “2′-modified sugar” means a furanosyl sugar modified at the 2′ position. In certain embodiments, such modifications include substituents selected from: a halide, including, but not limited to substituted and unsubstituted alkoxy, substituted and unsubstituted thioalkyl, substituted and unsubstituted amino alkyl, substituted and unsubstituted alkyl, substituted and unsubstituted allyl, and substituted and unsubstituted alkynyl. In certain embodiments, 2′ modifications are selected from substituents including, but not limited to: O[(CH 2 ) n O] m CH 3 , O(CH 2 ) n NH 2 , O(CH 2 ) n CH 3 , O(CH 2 ) n —ONH 2 , OCH 2 C(═O)N(H)CH 3 , and O(CH 2 ) n ON[(CH 2 ) n CH 3 ] 2 , where n and m are from 1 to about 10. Other 2′-substituent groups can also be selected from: C 1 -C 12 alkyl; substituted alkyl; alkenyl; alkynyl; alkaryl; aralkyl; O-alkaryl or O-aralkyl; SH; SCH 3 ; OCN; Cl; Br; CN; CF 3 ; OCF 3 ; SOCH 3 ; SO 2 CH 3 ; ONO 2 ; NO 2 ; N 3 ; NH 2 ; heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino; substituted silyl; an RNA cleaving group; a reporter group; an intercalator; a group for improving pharmacokinetic properties; and a group for improving the pharmacodynamic properties of an antisense compound, and other substituents having similar properties. In certain embodiments, modified nucleosides comprise a 2′-MOE side chain (see, e.g., Baker et al., J. Biol. Chem., 1997, 272, 11944-12000). Such 2′-MOE substitution have been described as having improved binding affinity compared to unmodified nucleosides and to other modified nucleosides, such as 2′-O-methyl, O-propyl, and O-aminopropyl. Oligonucleotides having the 2′-MOE substituent also have been shown to be antisense inhibitors of gene expression with promising features for in vivo use (see, e.g., Martin, P., Helv. Chim. Acta, 1995, 78, 486-504; Altmann et al., Chimia, 1996, 50, 168-176; Altmann et al., Biochem. Soc. Trans., 1996, 24, 630-637; and Altmann et al., Nucleosides Nucleotides, 1997, 16, 917-926).
As used herein, a “modified tetrahydropyran nucleoside” or “modified THP nucleoside” means a nucleoside having a six-membered tetrahydropyran “sugar” substituted in for the pentofuranosyl residue in normal nucleosides (a sugar surrogate). Modified THP nucleosides include, but are not limited to, what is referred to in the art as hexitol nucleic acid (HNA), anitol nucleic acid (ANA), manitol nucleic acid (MNA) (see Leumann, C J. Bioorg . & Med. Chem . (2002) 10:841-854), fluoro HNA (F-HNA), or those compounds having Formula X:
wherein independently for each of said at least one tetrahydropyran nucleoside analog of Formula X:
Bx is a heterocyclic base moiety;
T 3 and T 4 are each, independently, an internucleoside linking group linking the tetrahydropyran nucleoside analog to the antisense compound or one of T 3 and T 4 is an internucleoside linking group linking the tetrahydropyran nucleoside analog to the antisense compound and the other of T 3 and T 4 is H, a hydroxyl protecting group, a linked conjugate group, or a 5′ or 3′-terminal group;
q 1 , q 2 , q 3 , q 4 , q 5 , q 6 and q 7 are each, independently, H, C 1 -C 6 alkyl, substituted C 1 -C 6 alkyl, C 2 -C 6 alkenyl, substituted C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, or substituted C 2 -C 6 alkynyl; and
one of R 1 and R 2 is hydrogen and the other is selected from halogen, substituted or unsubstituted alkoxy, NJ 1 J 2 , SJ 1 , N 3 , OC(═X)J 1 , OC(═X)NJ 1 J 2 , NJ 3 C(═X)NJ 1 J 2 , and CN, wherein X is O, S, or NJ 1 , and each J 1 , J 2 , and J 3 is, independently, H or C 1 -C 6 alkyl.
In certain embodiments, the modified THP nucleosides of Formula X are provided wherein q m , q n , q p , q r , q s , q t , and q u are each H. In certain embodiments, at least one of q m , q n , q p , q r , q s , q t , and q u is other than H. In certain embodiments, at least one of q m , q n , q p , q r , q s , q t and q u is methyl. In certain embodiments, THP nucleosides of Formula X are provided wherein one of R 1 and R 2 is F. In certain embodiments, R 1 is fluoro and R 2 is H, R 1 is methoxy and R 2 is H, and R 1 is methoxyethoxy and R 2 is H.
As used herein, “2′-modified” or “2′-substituted” refers to a nucleoside comprising a sugar comprising a substituent at the 2′ position other than H or OH. 2′-modified nucleosides, include, but are not limited to, bicyclic nucleosides wherein the bridge connecting two carbon atoms of the sugar ring connects the 2′ carbon and another carbon of the sugar ring and nucleosides with non-bridging 2′ substituents, such as allyl, amino, azido, thio, O-allyl, O—C 1 -C 10 alkyl, —OCF 3 , O—(CH 2 ) 2 —O—CH 3 , 2′-O(CH 2 ) 2 SCH 3 , O—(CH 2 ) 2 —O—N(R m )(R n ), or O—CH 2 —C(═O)—N(R m )(R n ), where each R m and R n is, independently, H or substituted or unsubstituted C 1 -C 10 alkyl. 2′-modified nucleosides may further comprise other modifications, for example, at other positions of the sugar and/or at the nucleobase.
As used herein, “2′-F” refers to a sugar comprising a fluoro group at the 2′ position.
As used herein, “2′-OMe” or “2′-OCH 3 ” or “2′-O-methyl” each refers to a nucleoside comprising a sugar comprising an —OCH 3 group at the 2′ position of the sugar ring.
As used herein, “oligonucleotide” refers to a compound comprising a plurality of linked nucleosides. In certain embodiments, one or more of the plurality of nucleosides is modified. In certain embodiments, an oligonucleotide comprises one or more ribonucleosides (RNA) and/or deoxyribonucleosides (DNA).
Many other bicyclo and tricyclo sugar surrogate ring systems are also known in the art that can be used to modify nucleosides for incorporation into antisense compounds (see, e.g., review article: Leumann, J. C, Bioorganic & Medicinal Chemistry, 2002, 10, 841-854).
Such ring systems can undergo various additional substitutions to enhance activity.
Methods for the preparations of modified sugars are well known to those skilled in the art.
In nucleotides having modified sugar moieties, the nucleobase moieties (natural, modified, or a combination thereof) are maintained for hybridization with an appropriate nucleic acid target.
In certain embodiments, antisense compounds comprise one or more nucleotides having modified sugar moieties. In certain embodiments, the modified sugar moiety is 2′-MOE. In certain embodiments, the 2′-MOE modified nucleotides are arranged in a gapmer motif. In certain embodiments, the modified sugar moiety is a cEt. In certain embodiments, the cEt modified nucleotides are arranged throughout the wings of a gapmer motif.
Compositions and Methods for Formulating Pharmaceutical Compositions
Antisense oligonucleotides may be admixed with pharmaceutically acceptable active or inert substances for the preparation of pharmaceutical compositions or formulations. Compositions and methods for the formulation of pharmaceutical compositions are dependent upon a number of criteria, including, but not limited to, route of administration, extent of disease, or dose to be administered.
An antisense compound targeted to a STAT3 nucleic acid can be utilized in pharmaceutical compositions by combining the antisense compound with a suitable pharmaceutically acceptable diluent or carrier. A pharmaceutically acceptable diluent includes phosphate-buffered saline (PBS). PBS is a diluent suitable for use in compositions to be delivered parenterally. Accordingly, in one embodiment, employed in the methods described herein is a pharmaceutical composition comprising an antisense compound targeted to a STAT3 nucleic acid and a pharmaceutically acceptable diluent. In certain embodiments, the pharmaceutically acceptable diluent is PBS. In certain embodiments, the antisense compound is an antisense oligonucleotide.
Pharmaceutical compositions comprising antisense compounds encompass any pharmaceutically acceptable salts, esters, or salts of such esters, or any other oligonucleotide which, upon administration to an animal, including a human, is capable of providing (directly or indirectly) the biologically active metabolite or residue thereof. Accordingly, for example, the disclosure is also drawn to pharmaceutically acceptable salts of antisense compounds, prodrugs, pharmaceutically acceptable salts of such prodrugs, and other bioequivalents. Suitable pharmaceutically acceptable salts include, but are not limited to, sodium and potassium salts.
A prodrug can include the incorporation of additional nucleosides at one or both ends of an antisense compound which are cleaved by endogenous nucleases within the body, to form the active antisense compound.
Conjugated Antisense Compounds
Antisense compounds may be covalently linked to one or more moieties or conjugates which enhance the activity, cellular distribution or cellular uptake of the resulting antisense oligonucleotides. Typical conjugate groups include cholesterol moieties and lipid moieties. Additional conjugate groups include carbohydrates, phospholipids, biotin, phenazine, folate, phenanthridine, anthraquinone, acridine, fluoresceins, rhodamines, coumarins, and dyes.
Antisense compounds can also be modified to have one or more stabilizing groups that are generally attached to one or both termini of antisense compounds to enhance properties such as, for example, nuclease stability. Included in stabilizing groups are cap structures. These terminal modifications protect the antisense compound having terminal nucleic acid from exonuclease degradation, and can help in delivery and/or localization within a cell. The cap can be present at the 5′-terminus (5′-cap), or at the 3′-terminus (3′-cap), or can be present on both termini. Cap structures are well known in the art and include, for example, inverted deoxy abasic caps. Further 3′ and 5′-stabilizing groups that can be used to cap one or both ends of an antisense compound to impart nuclease stability include those disclosed in WO 03/004602 published on Jan. 16, 2003.
Certain Antisense Compounds
In certain embodiments, antisense compounds useful for treating B-cell lymphoma at the doses and dosing regimens described above include any of the antisense oligonucleotides described in WO 2012/135736, which is incorporated by reference in its entirety herein. Examples of antisense compounds described in WO 2012/135736 suitable for treating B-cell lymphoma include, but are not limited to, those described in Tables 1 & 2 below:
TABLE 1
cEt and MOE chimeric antisense oligonucleotides targeted to
STAT3 (SEQ ID NO: 1)
Human
SEQ
ISIS
Start
Human
Wing
ID
NO
Site
Stop
Sequence
Motif
Chem
NO
481355
322
337
ACTGCCGCAGCTCCAT
3-10-3
cEt
3
481597
731
744
GAGATTCTCTACCA
2-10-2
cEt
4
481374
788
803
AGATCTTGCATGTCTC
3-10-3
cEt
5
481390
1305
1320
ATAATTCAACTCAGGG
3-10-3
cEt
6
481420
1948
1963
ACTTTTTCACAAGGTC
3-10-3
cEt
7
481431
2206
2221
CCATGATCTTATAGCC
3-10-3
cEt
8
481453
2681
2696
GATAGCAGAAGTAGGA
3-10-3
cEt
9
481463
3001
3016
CAAGGTTAAAAAGTGC
3-10-3
cEt
10
481688
3002
3015
AAGGTTAAAAAGTG
2-10-2
cEt
11
481464
3016
3031
CTATTTGGATGTCAGC
3-10-3
cEt
12
481689
3017
3030
TATTTGGATGTCAG
2-10-2
cEt
13
481465
3032
3047
TAGATAGTCCTATCTT
3-10-3
cEt
14
481690
3033
3046
AGATAGTCCTATCT
2-10-2
cEt
15
481466
3047
3062
AAGAAACCTAGGGCTT
3-10-3
cEt
16
481691
3048
3061
AGAAACCTAGGGCT
2-10-2
cEt
17
481467
3097
3112
GCTGATACAGTGTTTT
3-10-3
cEt
18
481692
3098
3111
CTGATACAGTGTTT
2-10-2
cEt
19
481468
3112
3127
ATACAGAAAGGCTATG
3-10-3
cEt
20
481693
3113
3126
TACAGAAAGGCTAT
2-10-2
cEt
21
481469
3127
3142
GCTTAAGTTTCTTAAA
3-10-3
cEt
22
481694
3128
3141
CTTAAGTTTCTTAA
2-10-2
cEt
23
481470
3461
3476
AGCACCAAGGAGGCTG
3-10-3
cEt
24
481695
3462
3475
GCACCAAGGAGGCT
2-10-2
cEt
25
481471
3476
3491
AAGCTGAATGCTTAAA
3-10-3
cEt
26
481696
3477
3490
AGCTGAATGCTTAA
2-10-2
cEt
27
481472
3491
3506
TTACCAGCCTGAAGGA
3-10-3
cEt
28
481697
3492
3505
TACCAGCCTGAAGG
2-10-2
cEt
29
481473
3506
3521
CAGGGATTATATAAAT
3-10-3
cEt
30
481698
3507
3520
AGGGATTATATAAA
2-10-2
cEt
31
481474
3521
3536
ACCTGAAGCCCGTTTC
3-10-3
cEt
32
481699
3522
3535
CCTGAAGCCCGTTT
2-10-2
cEt
33
481475
3536
3551
TGTCTTAAGGGTTTGA
3-10-3
cEt
34
481700
3537
3550
GTCTTAAGGGTTTG
2-10-2
cEt
35
481476
3551
3566
GGTTGCAGCTTCAGAT
3-10-3
cEt
36
481701
3552
3565
GTTGCAGCTTCAGA
2-10-2
cEt
37
481477
3567
3582
TCAACACCAAAGGCCA
3-10-3
cEt
38
481702
3568
3581
CAACACCAAAGGCC
2-10-2
cEt
39
481478
3585
3600
TCCTTAAACCTTCCTA
3-10-3
cEt
40
481703
3586
3599
CCTTAAACCTTCCT
2-10-2
cEt
41
481479
3600
3615
AAAATGCTTAGATTCT
3-10-3
cEt
42
481704
3601
3614
AAATGCTTAGATTC
2-10-2
cEt
43
481480
3628
3643
AAATAAGTCTATTTAT
3-10-3
cEt
44
481705
3629
3642
AATAAGTCTATTTA
2-10-2
cEt
45
481481
3648
3663
GGCCAATACATTACAA
3-10-3
cEt
46
481706
3649
3662
GCCAATACATTACA
2-10-2
cEt
47
481482
3670
3685
TGCCCAGCCTTACTCA
3-10-3
cEt
48
481707
3671
3684
GCCCAGCCTTACTC
2-10-2
cEt
49
481483
3685
3700
GTTGTAAGCACCCTCT
3-10-3
cEt
50
481708
3686
3699
TTGTAAGCACCCTC
2-10-2
cEt
51
481484
3700
3715
AGAAAGGGAGTCAAGG
3-10-3
cEt
52
481709
3701
3714
GAAAGGGAGTCAAG
2-10-2
cEt
53
481485
3717
3732
GCAGATCAAGTCCAGG
3-10-3
cEt
54
481710
3718
3731
CAGATCAAGTCCAG
2-10-2
cEt
55
481486
3730
3745
AGCCTCTGAAACAGCA
3-10-3
cEt
56
481711
3731
3744
GCCTCTGAAACAGC
2-10-2
cEt
57
481487
3746
3761
CCCACAGAAACAACCT
3-10-3
cEt
58
481712
3747
3760
CCACAGAAACAACC
2-10-2
cEt
59
481488
3761
3776
AGCCCTGATAAGGCAC
3-10-3
cEt
60
481713
3762
3775
GCCCTGATAAGGCA
2-10-2
cEt
61
481489
3776
3791
AATCAGAAGTATCCCA
3-10-3
cEt
62
481714
3777
3790
ATCAGAAGTATCCC
2-10-2
cEt
63
481490
3833
3848
GCCTCTAGCAGGATCA
3-10-3
cEt
64
481715
3834
3847
CCTCTAGCAGGATC
2-10-2
cEt
65
481491
3848
3863
CACGCAAGGAGACATG
3-10-3
cEt
66
481716
3849
3862
ACGCAAGGAGACAT
2-10-2
cEt
67
481492
3863
3878
TGAGGGACCTTTAGAC
3-10-3
cEt
68
481717
3864
3877
GAGGGACCTTTAGA
2-10-2
cEt
69
481493
3886
3901
CAGGATTCCTAAAACA
3-10-3
cEt
70
481718
3887
3900
AGGATTCCTAAAAC
2-10-2
cEt
71
481494
3901
3916
ATGAGGTCCTGAGACC
3-10-3
cEt
72
481719
3902
3915
TGAGGTCCTGAGAC
2-10-2
cEt
73
481495
3940
3955
CATCATGTCCAACCTG
3-10-3
cEt
74
481720
3941
3954
ATCATGTCCAACCT
2-10-2
cEt
75
481496
3955
3970
GGGCCCCATAGTGTGC
3-10-3
cEt
76
481721
3956
3969
GGCCCCATAGTGTG
2-10-2
cEt
77
481497
3977
3992
AGCTCAACCAGACACG
3-10-3
cEt
78
481722
3978
3991
GCTCAACCAGACAC
2-10-2
cEt
79
481498
3992
4007
GAACCATATTCCCTGA
3-10-3
cEt
80
481723
3993
4006
AACCATATTCCCTG
2-10-2
cEt
81
481499
4007
4022
CAAGAAACTGGCTAAG
3-10-3
cEt
82
481724
4008
4021
AAGAAACTGGCTAA
2-10-2
cEt
83
481500
4022
4037
GCCACTGGATATCACC
3-10-3
cEt
84
481501
4048
4063
AACTGAATGAAGACGC
3-10-3
cEt
85
481523
4489
4504
GCTTATTATGTACTGA
3-10-3
cEt
86
481748
4490
4503
CTTATTATGTACTG
2-10-2
cEt
87
481524
4530
4545
GCCCAAGTCTCACCTT
3-10-3
cEt
88
481749
4531
4544
CCCAAGTCTCACCT
2-10-2
cEt
89
481525
4541
4556
CCCAATGGTAAGCCCA
3-10-3
cEt
90
481750
4542
4555
CCAATGGTAAGCCC
2-10-2
cEt
91
481526
4543
4558
AACCCAATGGTAAGCC
3-10-3
cEt
92
481751
4544
4557
ACCCAATGGTAAGC
2-10-2
cEt
93
481527
4560
4575
TAGGTCCCTATGATTT
3-10-3
cEt
94
481752
4561
4574
AGGTCCCTATGATT
2-10-2
cEt
95
481528
4579
4594
AAGCCCTGAACCCTCG
3-10-3
cEt
96
481753
4580
4593
AGCCCTGAACCCTC
2-10-2
cEt
97
481529
4615
4630
CCTAAGGCCATGAACT
3-10-3
cEt
98
481754
4616
4629
CTAAGGCCATGAAC
2-10-2
cEt
99
481530
4630
4645
ACCAGATACATGCTAC
3-10-3
cEt
100
481755
4631
4644
CCAGATACATGCTA
2-10-2
cEt
101
481531
4646
4661
TACAATCAGAGTTAAG
3-10-3
cEt
102
481756
4647
4660
ACAATCAGAGTTAA
2-10-2
cEt
103
481532
4664
4679
TCCTCTCAGAACTTTT
3-10-3
cEt
104
481757
4665
4678
CCTCTCAGAACTTT
2-10-2
cEt
105
481533
4666
4681
GCTCCTCTCAGAACTT
3-10-3
cEt
106
481758
4667
4680
CTCCTCTCAGAACT
2-10-2
cEt
107
481534
4693
4708
TTCTTTAATGGGCCAC
3-10-3
cEt
108
481759
4694
4707
TCTTTAATGGGCCA
2-10-2
cEt
109
481535
4767
4782
ACGGGATTCCCTCGGC
3-10-3
cEt
110
481760
4768
4781
CGGGATTCCCTCGG
2-10-2
cEt
111
481536
4782
4797
GTAGGTAAGCAACCCA
3-10-3
cEt
112
481761
4783
4796
TAGGTAAGCAACCC
2-10-2
cEt
113
481537
4830
4845
GAATTTGAATGCAGTG
3-10-3
cEt
114
481762
4831
4844
AATTTGAATGCAGT
2-10-2
cEt
115
481538
4844
4859
TGAAGTACACATTGGA
3-10-3
cEt
116
481763
4845
4858
GAAGTACACATTGG
2-10-2
cEt
117
481539
4860
4875
ATAAATTTTTACACTA
3-10-3
cEt
118
481764
4861
4874
TAAATTTTTACACT
2-10-2
cEt
119
481765
4869
4882
CAATAATATAAATT
2-10-2
cEt
120
481541
4934
4949
CTGGAAGTTAAAGTAG
3-10-3
cEt
121
481766
4935
4948
TGGAAGTTAAAGTA
2-10-2
cEt
122
TABLE 2 Chimeric antisense oligonucleotides targeted to STAT3 (SEQ ID NO: 2) Human Human Start Stop SEQ ID Site Site ISIS No Sequence Chemistry NO 5701 5716 GTACTCTTTCAGTGGT 529962 e-e-e-d(10)-k-k-k 123 74784 74799 ATGCTTAGATTCTCCT 529979 k-k-k-d(10)-e-e-e 124 74905 74920 AGCAGATCAAGTCCAG 529982 k-k-k-d(10)-e-e-e 125 75423 75438 AGGTGTTCCCATACGC 529983 k-k-k-d(10)-e-e-e 126 75424 75439 TAGGTGTTCCCATACG 529984 k-k-k-d(10)-e-e-e 127 5701 5716 GTACTCTTTCAGTGGT 529999 k-k-k-d(10)-e-e-e 123 9878 9893 GGTTCCTCCTGTTGGC 530006 k-k-k-d(10)-e-e-e 128 12361 12376 GGTTCCTCCTGTTGGC 530006 k-k-k-d(10)-e-e-e 128 74783 74799 ATGCTTAGATTCTCCTT 530020 e-e-k-d(10)-k-e-k-e 129
Certain Combination Therapies
In certain embodiments, one or more pharmaceutical compositions provided herein are co-administered with one or more other pharmaceutical agents. In certain embodiments, such one or more other pharmaceutical agents are designed to treat the same disease, disorder, or condition as the one or more pharmaceutical compositions provided herein. In certain embodiments, such one or more other pharmaceutical agents are designed to treat a different disease, disorder, or condition as the one or more pharmaceutical compositions provided herein. In certain embodiments, such one or more other pharmaceutical agents are designed to treat an undesired side effect of one or more pharmaceutical compositions provided herein. In certain embodiments, one or more pharmaceutical compositions provided herein are co-administered with another pharmaceutical agent to treat an undesired effect of that other pharmaceutical agent. In certain embodiments, one or more pharmaceutical compositions provided herein are co-administered with another pharmaceutical agent to produce a combinational effect. In certain embodiments, one or more pharmaceutical compositions provided herein are co-administered with another pharmaceutical agent to produce a synergistic effect.
In certain embodiments, one or more pharmaceutical compositions provided herein and one or more other pharmaceutical agents are administered at the same time. In certain embodiments, one or more pharmaceutical compositions provided herein and one or more other pharmaceutical agents are administered at different times. In certain embodiments, one or more pharmaceutical compositions provided herein and one or more other pharmaceutical agents are prepared together in a single formulation. In certain embodiments, one or more pharmaceutical compositions provided herein and one or more other pharmaceutical agents are prepared separately. In certain embodiments, one or more other pharmaceutical agents include all-trans retinoic acid, azacitidine, azathioprine, bleomycin, carboplatin, capecitabine, cisplatin, chlorambucil, cyclophosphamide, cytarabine, daunorubicin, docetaxel, doxifluridine, doxorubicin, epirubicin, epothilone, etoposide, fluorouracil, gemcitabine, hydroxyurea, idarubicin, imatinib, mechlorethamine, mercaptopurine, methotrexate, mitoxantrone, oxaliplatin, paclitaxcel, pemetrexed, teniposide, tioguanine, valrubicin, vinblastine, vincristine, vindesine, or vinorelbine. In certain embodiments, one or more other pharmaceutical agents include a combination of cyclophosphamide, hydroxydanuorubicin, oncovin (vincristine), prednisone or prednisolone (CHOP). In certain embodiments, one or more other pharmaceutical agents include a combination of rituximab and CHOP (R-CHOP). In certain embodiments, one or more other pharmaceutical agents include another antisense oligonucleotide. In certain embodiments, another antisense oligonucleotide is a second STAT3 antisense oligonucleotide.
In certain embodiments, one or more other pharmaceutical agents include molecular targeted therapies. In certain embodiments, the molecular targeted therapy is an EGFR inhibitor, a mTOR inhibitor, a HER2 inhibitor, or a VEGF/VEGFR inhibitor. In certain embodiments, EGFR inhibitors include gefitinib, erlotinib, lapatinib, cetuximab, panitumumbo. In certain embodiments, mTOR inhibitors include everolimus and temsirolimus. In certain embodiments, HER2 inhibitors include trastuzumab and lapatinib. In certain embodiments, VEGF/VEGFR inhibitors include pazopanib, bevacizumab, sunitinib, and sorafenib.
In certain embodiments, one more pharmaceutical compositions provided herein are administered with radiation therapy. In certain embodiments, one or more pharmaceutical compositions are administered at the same time as radiation therapy. In certain embodiments, one or more pharmaceutical compositions are administered before radiation therapy. In certain embodiments, one or more pharmaceutical compositions are administered after radiation therapy. In certain embodiments, one or more pharmaceutical compositions are administered at various time points throughout a radiation therapy regimen.
In certain embodiments, radiation therapy is useful for inhibiting tumor growth. In certain embodiments, radiation therapy is useful for increasing overall survival. In certain embodiments, radiation therapy used in conjunction with administration of one or more pharmaceuticals provided herein is advantageous over using either therapy alone because both radiation therapy and administration with one or more pharmaceuticals can be limited to achieve effective antiproliferative response with limited toxicity.
In certain embodiments, a physician designs a therapy regimen including both radiation therapy and administration of one more pharmaceutical compositions provided herein. In certain embodiments, a physician designs a therapy regimen including radiation therapy, administration of one or more pharmaceutical compositions provided herein, and administration of one or more other chemotherapeutic agents.
EXAMPLES
Non-Limiting Disclosure and Incorporation by Reference
While certain compounds, compositions and methods described herein have been described with specificity in accordance with certain embodiments, the following examples serve only to illustrate certain embodiments described herein and are not intended to limit the same. Each of the references recited in the present application is incorporated herein by reference in its entirety.
Example 1: Phase 1, Open-Label, Study for Treating a Patient Having Advanced B Cell Lymphoma with a STAT3 Antisense Oligonucleotide
The effect of intravenous infusion of the STAT3 antisense oligonucleotide, ISIS 481464, in patients with advanced B cell lymphomas was studied. Patients with diffuse large B-cell lymphomas (DLBCL) were recruited for this study.
The criteria for patient inclusion with respect to their tumor status was that the tumors should be relapsed or refractory to at least one prior anti-cancer systemic therapy, and/or for which no standard therapy exists; that their disease should be measurable or evaluable, according to RECIST version 1.1 for solid tumors, or according to the International Workshop Response Criteria for Non-Hodgkin's Lymphoma for NHL tumors (Cheson, B. D. et al., J. Clin. Oncol. 1999, 17: 1244; Cheson, B. D. et al., J. Clin. Oncol. 2007, 25(5):579-86), or according to appropriate criteria for other advanced cancers. RECIST (Response Evaluation Criteria in Solid Tumors) is an internationally accepted set of guidelines used in clinical trials for solid tumor disease.
One patient fitting the criteria above is a 63 year old female with DLBCL designated herein as Patient #1001. Prior to commencing therapy, Patient #1001 showed multiple areas of hypermetabolic adenopathy, both above and below the diaphragm, including the supraclavicular, left paratracheal, right internal mammary, pericardial, left intra-mammary, pre-hepatic, retroperitoneal, and mesenteric regions. In addition, the patient suffered from fatigue, nausea, night sweats, shortness of breath on exertion, and peripheral neuropathy. The patient also noted 5-6 days of right-sided abdominal fullness and associated pain. Patient therapy was commenced with a treatment period comprising administration during a first phase of 3 loading doses of ISIS 481464: a 3-hr intravenous infusion of 2 mg/kg ideal body weight of ISIS 481464 administered on days 1, 3, and 5 of cycle 0. The ideal body weight was determined using the Devine formula (Pai, M. P. and Paloucek, F. P. Ann. Pharmacol. 2000. 34: 1066-1069): for men (in kg)=50+2.3 kg/inch over 5 feet; for women (in kg)=45.5+2.3 kg/inch over 5 feet. Treatment was then continued in a second phase by once-weekly administrations (Cycle 1 and beyond) of 2 mg/kg ideal body weight of ISIS 481464 until disease progression, unacceptable toxicity, or patient discontinuation for any other reason occurred. Disease assessments were performed at the end of even cycles.
Tumor lesions were evaluated on each even-numbered cycle, starting with Cycle 2, day 15, by positron emission tomography (PET) scan. According to RECIST guidelines, a complete tumor response is achieved when all target lesions have disappeared. Partial response is achieved when the sum of the diameters of all tumor lesions is reduced at least 30% compared to the sum of the tumor lesion diameters at pre-dose. The sum of the lesion diameters, if any, was calculated, per RECIST guidelines (Eisenhauer, E. A. et al., Eur. J. Cancer 45: 228-247, 2009).
After 28 days of treatment with ISIS 481464, the patient reported reduced fatigue and night sweats, and was tolerating the treatment well.
After 49 days of treatment with ISIS 481464, a PET scan was performed and revealed a 55% reduction in tumor size. Tumors were reduced in all compartments, but most notably, in the supraclavicular, paratracheal, pericardial, and mesenteric regions.
After 91 days of treatment with ISIS 481464, Patient #1001 had a second PET scan and the partial response observed in the first scan was found to be maintained at a 55% reduction in tumor size.
After 133 days of treatment with ISIS 481464, Patient #1001 had a third PET scan and the partial response was found to be maintained at a 55% reduction in tumor size.
After 162 days of treatment with ISIS 481464, further treatment was paused for a month during which Patient #1001 had a fourth PET scan, and the partial response was maintained at a 55% reduction in tumor size. Patient #1001 is scheduled for further scans.
Example 2: Phase 1, Open-Label, Study for Treating a Patient Having Advanced/Metastatic Hepatocellular Carcinoma with a STAT3 Antisense Oligonucleotide
The effect of intravenous infusion of the STAT3 antisense oligonucleotide, ISIS 481464, in patients with advanced/metastatic hepatocellular carcinoma is being studied in an on-going clinical trial.
In the study described in this protocol, AZD9150 will be administered to patients with advanced/metastatic hepatocellular carcinoma at a starting dose of 1 mg/kg intravenously 3× during week 1 followed by 1× weekly and dose intensity will be escalated or de-escalated in subsequent cohorts through modification of unit dose administered and/or interval of administration to determine a maximum tolerated dose and recommended phase II dose in patients with advanced/metastatic hepatocellular carcinoma (HCC).
Following the dose escalation phase of the study additional patients will be enrolled to a dose expansion phase to explore further the safety, tolerability, pharmacokinetics and biological activity at selected dose(s)/schedules. Patients included in the study are relapsed, refractory, intolerant or unlikely to benefit from first-line systemic therapy (sorafenib).
To date, the 1 mg/kg and 1.5 mg/kg cohorts have completed. From the 1 mg/kg cohort 4 patients remain on study with stable disease in excess of 3 months. Stable disease has also been seen in 1.5 mg/kg cohort. These patients and future patients will be monitored further for clinical activity as the trial progresses. | In certain embodiments, methods, compounds, and compositions for treating B-cell lymphoma or hepatocellular carcinoma by inhibiting expression of ST AT3 mRNA or protein in an animal are provided herein. Such methods, compounds, and compositions are useful to treat, prevent, or ameliorate B-cell lymphoma or hepatocellular carcinoma. The STAT (signal transducers and activators of transcription) family of proteins are DNA-binding proteins that play a dual role in signal transduction and activation of transcription. | 2 |
FIELD OF THE INVENTION
The present invention relates to a delay locked loop (DLL) for compensating a clock skew between an external clock signal and an internal clock signal; and, more particularly, to a DLL capable of correcting a duty cycle of the external clock signal.
DESCRIPTION OF PRIOR ART
Generally, in a synchronous semiconductor memory device, data access operations such as a read operation and a write operation are performed in synchronization with rising and falling edges of an external clock signal.
Since there is a time delay while the external clock signal is inputted to the synchronous semiconductor memory device in order to be used as an internal clock signal of the synchronous semiconductor memory device, a delay locked loop (DLL) is employed for synchronizing the internal clock signal with the external clock signal by compensating a clock skew between the internal clock signal and the external clock signal.
As an operational speed of the synchronous semiconductor memory device is increased, an apparatus for synchronizing the internal clock signal with the external clock signal and correcting a duty cycle of the external clock signal has been required for enhancing a performance of the synchronous semiconductor memory device. Therefore, various techniques of the DLL have been introduced for compensating the clock skew between the internal clock signal and the external clock signal and for correcting the duty cycle.
FIG. 1 is a block diagram showing a conventional DLL disclosed in a commonly owned copending application, U.S. Ser. No. 10/331,412, filed on Dec. 30, 2002, entitled “DIGITAL DLL APPARATUS FOR CORRECTING DUTY CYCLE AND METHOD THEREOF”, which is incorporated herein by reference.
As shown, the conventional DLL includes a buffer 110 , a delay line unit 120 , a duty error controller 130 , a first delay model unit 140 , a first direct phase detector 150 , a second delay model unit 160 and a second direct phase detector 170 .
The buffer 110 receives an external clock signal ext_clk and generates a first internal clock signal by buffering the external clock signal ext_clk. The first internal clock signal is inputted to the delay line unit 120 .
The delay line unit 120 receives the first internal clock signal and also receives a first and a second detection signals from the first and the second direct phase detectors 150 and 170 . The delay line unit 120 delays the first internal clock signal based on the first and the second detection signals and outputs a first delayed internal clock signal intclk 1 and a second delayed internal clock signal intclk 2 to the duty error controller 130 .
In detail, the delay line unit 120 includes a first controller 121 , a first delay line 122 , a second controller 123 and a second delay line 124 .
The first controller 121 generates a first control signal for controlling a delay amount according to the first detection signal and outputs the first control signal to the first delay line 122 .
The first delay line 122 receives the first control signal and the first internal clock signal. The first internal clock signal is delayed according to the first control signal through the delay line 122 . That is, the first delay line 122 generates the first delayed internal clock signal intclk 1 by delaying the first internal clock signal according to the first control signal. The first delayed internal clock signal intclk 1 is inputted to the duty error controller 130 .
The second controller 123 outputs a second control signal to the second delay line 124 for controlling a delay amount according to the second detection signal.
The second delay line 124 receives the second control signal and the first internal clock signal. The second delay line 124 delays the first internal clock signal based on the second control signal. Then, the delayed first internal clock signal is inverted and outputted as the second delayed internal clock signal intclk 2 . The second delayed internal clock signal intclk 2 is outputted to the duty error controller 130 .
The duty error controller 130 receives the first and the second delayed internal clock signals intclk 1 and intclk 2 . The duty error controller 130 generates a first duty controlled clock signal int_clk and a second duty controlled clock signal intclk 2 ′ by adjusting falling edges of the first and the second duty controlled clock signals int_clk and intclk 2 ′ to a middle of the falling edges of the first and the second duty controlled clock signals int_clk and intclk 2 ′. Herein, after the first and the second duty controlled clock signals int_clk and intclk 2 ′ are duty corrected by shifting their falling edges as mentioned above, a 50% duty ratio. The first and the second duty controlled clock signals int_clk and intclk 2 ′ are respectively outputted to the first and the second delay model units 140 and 160 .
The duty error controller 130 includes a first phase detector 131 , a mixer controller 132 , a first phase mixer 133 and a second phase mixer 134 .
The first and the second delayed internal clock signals intclk 1 and intclk 2 are inverted and inputted to the first phase detector 131 . The first phase detector 131 compares phases of falling edges of the first and the second delayed internal clock signals intclk 1 and the intclk 2 in order to determine which one of their falling edges leads the other for generating a phase detection signal based on the comparison result. The phase detection signal is outputted to the mixer controller 132 .
The mixer controller 132 receives the phase detection signal to determine a weight k, which contains a phase difference between two falling edges of the first and the second delayed internal clock signals intclk 1 and intclk 2 , according to the phase detection signal. The weight k is outputted to the first and the second phase mixers 133 and 134 . The weight k includes the plural number of weight signals.
The first phase mixer 133 receives the weight k, the first and the second delayed internal clock signals intclk 1 and intclk 2 . The first phase mixer 133 calculates a difference value by subtracting the weight k from 1. By applying the difference value to the first delayed internal clock signal intclk 1 and applying the weight k to the second delayed internal clock signals intclk 2 , the first phase mixer 133 generates a first duty controlled clock signal int_clk. The first duty controlled clock signal int_clk is outputted to the first delay model unit 140 .
The second phase mixer 134 receives the weight k and calculates a difference value by subtracting the weight k from 1. The second phase mixer 134 generates a second duty controlled clock signal intclk 2 ′ by applying the weight k to the first delayed internal clock signal intclk 1 and applying the difference value to the second delayed internal clock signal intclk 2 . The second phase mixer 134 outputs the second duty controlled clock signal intclk 2 ′ to the second delay model unit 160 .
Herein, as above mentioned, the first and the second duty controlled clock signals int_clk and intclk 2 ′ are generated by adjusting their falling edges to a middle of their falling edges; and a direction and a amount of the phase shift is determined by the weight k and the difference value.
The first delay model unit 140 receives the first duty controlled clock signal int_clk and estimates a delay amount generated while the external clock signal ext_clk is passed through the conventional DLL to be outputted as the first and the second duty controlled clock signals int_clk and intclk 2 ′. The first delay model unit 140 generates a first compensated clock signal iclk 1 based on the estimated delay amount and outputs the first compensated clock signal iclk 1 to the first direct phase detector 150 .
The first direct phase detector 150 receives the external clock signal ext_clk and the first compensated clock signal iclk 1 to thereby generate the first detection signal in response to a result of comparing the external clock signal ext_clk with the first compensated clock signal iclk 1 . The first detection signal is inputted to the delay line unit 120 .
The second delay model unit 160 receives the second duty controlled clock signal intclk 2 ′ and estimates a delay amount generated while the second duty controlled clock signal intclk 2 ′ travels from the conventional DLL to a data input/output pin (DQ pin). The second delay model unit 160 generates a second compensated clock signal iclk 2 based on the estimated delay amount and outputs the second compensated clock signal iclk 2 to the second direct phase detector 170 .
The second direct phase detector 170 receives the external clock signal ext_clk and the second compensated clock signal iclk 2 to generate the second detection signal based on a result of comparing the external clock signal ext_clk and the second compensated clock signal iclk 2 . The generated second detection signal is inputted to the delay line unit 120 .
However, using the first and the second delay lines 122 and 124 , the conventional DLL shown in FIG. 1 synchronizes both of the first and the second compensated clock signals iclk 1 and iclk 2 with a rising edge of the external clock signal ext_clk respectively. Therefore, each of the first and the second delay lines should have a delay amount of 1tCK as shown in FIG. 2 . As a result, whole delay amount of both the first and the second delay lines should have a delay amount of 2tCK.
Furthermore, if a conventional DLL has a dual delay line structure, the whole delay amount becomes 4tCK. Herein, in the dual delay line structure, a first and a second delay lines are respectively constituted with a coarse and a fine delay lines. As result, a size of a semiconductor memory device is increased, and a power consumption of the semiconductor memory device is also increased.
SUMMARY OF INVENTION
It is, therefore, an object of the present invention to provide a DLL device capable of reducing a length of a delay line and reducing a delay locking time.
In accordance with an aspect of the present invention, there is provided a semiconductor device for adjusting a clock signal, including: a clock multiplexing unit for receiving an external clock signal, an external clock bar signal and a feed-backed clock signal in order to select one of the external clock signal and the external clock bar signal as an output signal of the clock multiplexing unit based on a result of comparing a phase of the external clock signal with a phase of the feed-backed clock signal; and a delay locked loop (DLL) for generating a duty corrected clock signal and the feed-backed clock signal in response to the output signal of the clock multiplexing unit.
In accordance with another aspect of the present invention, there is provided a method of generating a duty corrected clock signal using an external clock signal, including the steps of: generating a rising edge clock signal whose rising edge is synchronized with a rising edge of the external clock signal; generating a falling edge clock signal whose falling edge is synchronized with a rising edge of the external clock signal; selecting one of the rising edge clock signal and the falling edge clock signal based on a feed-backed clock signal; generating a first delay locked clock signal and a second delay locked clock signal by delaying the one of the rising edge clock signal and the falling edge clock signal within one clock cycle of the external clock signal based on a first phase detecting signal and a second phase detecting signal; and generating a first output clock signal and a second output clock signal by delaying the first delay locked clock signal and the second delay locked clock signal; and generating the duty corrected clock signal by correcting duty cycles of the first output clock signal and the second output clock signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram showing a conventional DLL;
FIG. 2 is a timing diagram showing an operation of the conventional DLL shown in FIG. 1 ;
FIG. 3 is a block diagram showing a DLL in accordance with the present invention;
FIG. 4 is a timing diagram showing an operation of the DLL shown in FIG. 3 ;
FIG. 5 is a schematic circuit diagram showing a delay line unit shown in FIG. 3 ;
FIG. 6 is a schematic circuit diagram showing a clock signal selector shown in FIG. 3 ; and
FIG. 7 is a timing diagram showing an operation of a first and a second phase detectors shown in FIG. 6 .
DETAILED DESCRIPTION OF INVENTION
Hereinafter, a delay locked loop in accordance with the present invention will be described in detail referring to the accompanying drawings.
FIG. 3 is a block diagram showing a delay locked loop (DLL) in accordance with the present invention.
As shown, the DLL includes a clock multiplexing unit 310 , a first direct phase detector 350 , a second direct phase detector 370 , a first delay model unit 340 , a second delay model unit 360 , a delay line unit 320 , a first clock phase control unit 380 , a second clock phase control unit 390 and a duty cycle correction unit 330 .
The clock multiplexing unit 310 receives an external clock signal CLK and an inverted signal of the external clock signal CLK, i.e., an external clock bar signal /CLK. The clock multiplexing unit 310 selects one of the external clock signal CLK and the external clock bar signal /CLK in order to output the selected clock signal to the delay line unit 320 so that the selected clock signal can be delay locked within tCK/2 in the delay line unit 320 , wherein the tCK is a clock cycle of the external clock signal CLK.
The clock multiplexing unit 310 includes a first input buffer 311 , a second input buffer 312 , a clock signal selector 313 and a multiplexer 314 .
The first input buffer 311 receives the external clock signal CLK and the external clock bar signal /CLK respectively through a non-inverting terminal (+) and an inverting terminal (−) of the first input buffer 311 in order to output the external clock signal CLK as a rising edge clock signal rclk by buffering the external clock signal CLK. The second input buffer 312 receives the external clock bar signal /CLK respectively through an inverting terminal (−) and a non-inverting terminal (+) of the second input buffer 312 in order to output the external clock bar signal /CLK as a falling edge clock signal fclk by buffering the external clock bar signal /CLK. Herein, the rising edge clock signal rclk is synchronized with the external clock signal CLK, and the falling edge clock signal fclk is synchronized with the external clock bar signal /CLK.
The clock signal selector 313 compares a phase of the external clock signal CLK with a phase of a feed-backed clock signal fb_clk outputted from the first delay model unit 340 in order to generate a clock selection signal clk_sel.
The multiplexer 314 selects one of the rising edge clock signal rclk and the falling edge clock signal fclk based on the clock selection signal clk_sel in order to output the selected signal to the delay line unit 320 .
The delay line unit 320 includes a first delay line 322 , a first delay line controller 321 , a second delay line 324 and a second delay line controller 323 .
The rising edge clock signal rclk or the falling edge clock signal fclk selected by the multiplexer is delay locked within tCK/2 in the first delay line 322 . Thereafter, the first delay line 320 outputs a first delay locked clock signal pre_clk to the first clock phase control unit 380 and the second delay line 324 .
Meanwhile, the first direct phase detector 350 generates a first phase detecting signal pd 1 . The first phase detecting signal pd 1 is inputted to both of the first delay line controller 321 and the second delay line controller 323 . The first and the second delay line controllers 321 and 323 respectively control delay amounts of the first and the second delay lines 322 and 324 based on the first phase detecting signal pd 1 . Since the first phase detecting signal pd 1 is inputted both of the first and the second delay line controllers 321 and 323 , the first delay locked clock signal pre_clk is delayed in the second delay line 324 for the same delay time as that of the first delay line 322 . The second delay line 324 outputs a second delay locked clock signal by delaying the first delay locked clock signal pre_clk.
FIG. 4 is a timing diagram showing an operation of the digital DLL.
As shown, the feed-backed clock signal fb_clk should be delayed for a delay amount of α to be synchronized with the external clock signal CLK. Therefore, the first direct phase detector 350 outputs the first phase detecting signal pd 1 to the first and the second delay line controllers 321 and 323 for controlling the first and the second delay lines 322 and 324 to have the delay amount of α. Subsequently, the first delay line 322 delays the feed-backed clock signal fb_clk for the delay amount of α, and, then, outputs the delayed signal as the first delay locked clock signal pre_clk. As a result, a rising edge of the first delay locked clock signal pre_clk is synchronized with a rising edge of the external clock signal CLK.
Meanwhile, the first delay locked clock signal pre_clk is delayed for the delay amount of α by the second delay line 324 . Herein, since the first and the second delay lines 322 and 324 are connected in series, the second delay line 324 receives the first delay locked clock signal pre_clk from the first delay line 322 . Subsequently, the second delay locked clock signal post_clk outputted from the second delay line 324 becomes a delayed version of the feed-backed clock bar signal /fb_clk inputted to the second direct phase detector 370 having a delay amount of 2α.
At this time, since the first delay locked clock signal pre_clk is synchronized with the external clock signal CLK, a delay amount of the first delay line 322 is no longer changed. The second delay locked clock signal post_clk is still required to be delayed for a delay amount of β to be synchronized with the external clock signal CLK. Therefore, the second delay locked clock signal post_clk is delayed for the delay amount of β under control of the second direct phase detector 370 and the second delay line controller 323 .
Above-mentioned delay locking operation of the first and the second delay lines 322 and 324 is referred as a coarse delay operation.
Meanwhile, the first clock phase control unit 380 includes a first fine delay line 381 , a second fine delay line 382 and a first phase mixer 383 . Likewise, the second clock phase control unit 390 includes a third fine delay line 391 , a fourth fine delay line 392 and a second phase mixer 393 .
The first and the second fine delay lines 381 and 382 perform a fine delay operation to the first delay locked clock signal pre_clk respectively. Likewise, the third and the fourth fine delay lines 391 and 392 perform the fine delay operation to the second delay locked clock signal post_clk respectively. The fine delay operation is performed in order to finely delay the first and the second delay locked clock signal pre_clk and post_clk for phase locking. The fine delay operation is performed independently of the coarse delay operation.
Since an operation of the first clock phase control unit 380 is same to that of the second clock phase control unit 390 , only the operation of the first clock phase control unit 380 is described below.
The first delay locked clock signal pre_clk is inputted to the first and the second fine delay lines 381 and 382 . Herein, the number of unit delay cells included in the first fine delay line 381 can be smaller that that of the second fine delay line 382 by one. That is, a weight value K is determined based on the first phase detecting signal pd 1 ; and, the number of unit delay cells, through which the first delay locked clock signal pre_clk is passed in the first fine delay line 381 , is determined based on a control signal outputted from the first phase mixer 383 . Herein, the number of unit delay cells of the first fine delay line 381 passed by the first delay locked clock signal pre_clk is smaller than that of the second fine delay line 382 passed by the first delay locked clock signal pre_clk by one.
That is, if the number of unit delay cells passed by the first delay locked clock signal pre_clk in the first fine delay line is 1, 3 or 5, the number of unit delay cells passed by the first delay locked clock signal pre_clk in the second fine delay line is 2, 4 or 6 respectively. For example, if the first delay locked clock signal pre_clk is passed through three unit delay cells in the first fine delay line 381 , the first delay locked clock signal pre_clk is passed through four unit delay cells in the second fine delay line 382 .
The first and the second fine delay lines 381 and 382 respectively output a first input signal IN 1 and a second input signal IN 2 to the first phase mixer 383 .
If the weigh value K is set to 0 based on the first phase detecting signal pd 1 , the first fine delay line 381 outputs the first delay locked clock signal pre_clk without delaying the first delay locked clock signal pre_clk.
However, if it is detected that a phase of the feed-backed clock signal fb_clk leads a phase of the external clock signal CLK by the first direct phase detector 351 , the first phase mixer 383 increases the weight value K. The more the weight value K is approached to 1, the more an outputted clock signal of the phase mixer 383 is synchronized with the second input signal IN 2 .
Thereafter, if the weight value becomes 1, the first phase mixer 383 outputs the second input signal IN 2 as the outputted clock signal of the phase mixer 383 . At this time, if a phase of the feed-backed clock signal fb_clk is still leads a phase of the external clock signal CLK, the first phase mixer 383 shifts a delay amount of the first fine delay line 381 in a left direction. That is, the number of unit delay cells passed by the first delay locked clock signal pre_clk is increased by two, e.g., 1 to 3 or 3 to 5. At this time, since the weigh value K is 1, the outputted clock signal of the first phase mixer 383 is not influenced by delay amount variance of the first fine delay line 381 .
If it is required that the feed-backed clock signal fb_clk is more delayed after left-shifting the delay amount of the first fine delay line 381 , the weight value K is decreased. If the weight value K is decreased, a phase of the outputted clock signal of the first phase mixer 383 is approached to a phase of the first input signal IN 1 .
Meanwhile, for decreasing a delay amount of the first and the second fine delay lines 383 and 393 , the above-mentioned operation can be performed in an opposite way.
In addition, the first phase mixer 383 generates a plurality of control signals, i.e., a shift-right signal and a shift-left signal for controlling a delay amount of the first and the second fine delay lines 381 and 382 . The first phase mixer 383 can be designed by various design techniques, e.g., an up-down counter or a decoder, which is well known to those skilled in the art.
Since a delay locking operation is almost completed by the coarse delay operation, the fine delay operation is performed in order to finely adjust a small delay variance generated due to external noises such as a power supply voltage variance. Therefore, a physical delay line length for adjusting the small delay variance is an enough physical length of the first to the fourth fine delay lines 381 , 382 and 392 .
FIG. 5 is a schematic circuit diagram showing the delay line unit 320 shown in FIG. 3 .
As shown, the first delay line controller 321 generates a first to a third shift-left signals SL 1 to SL 3 based on the first phase detecting signal pd 1 . The first delay line 322 delays input signals of the first line 322 according to the first to the third shift-left signals SL 1 to SL 3 . The second delay line 324 has the same structure with the first delay line 322 .
FIG. 6 is a schematic circuit diagram showing the clock signal selector 313 shown in FIG. 3 .
As shown, the clock signal selector 313 includes a feed-backed clock delay unit 621 , a first phase detector 623 , a second phase detector 625 , a p-channel metal oxide semiconductor (PMOS) transistor 627 and a first to a third n-channel metal oxide semiconductor (NMOS) transistors 629 to 633 .
The feed-backed clock delay unit 621 delays the feed-backed clock signal for a predetermined delay time in order to generate a delayed feed-backed clock signal fb_clkd. The first phase detector 623 compares phases of the external clock signal CLK and the feed-backed clock signal fb_clk. The second phase detector 625 compares phases of the external clock signal CLK and the delayed feed-backed clock signal fb_clkd.
The feed-backed clock delay unit 621 includes K numbers of unit delay cells. The K numbers of unit delay cells are required numbers of unit delay cells in order to delaying the feed-backed clock signal avoiding a dead zone.
FIG. 7 is a timing diagram showing an operation of the first and the second phase detectors 623 and 625 .
As shown, if a phase of a signal inputted to a first terminal ‘a’ leads a phase of a signal inputted to a second terminal ‘b’, an output signal of the first phase detector 623 or the second phase detector 625 is in a logic high level. On the other hand, if a phase of a signal inputted to a first terminal ‘a’ lags behind a phase of a signal inputted to a second terminal ‘b’, an output signal of the first phase detector 623 or the second phase detector 625 is in a logic low level.
Therefore, if a phase of the external clock signal CLK leads phases of the feed-backed clock signal fb_clk and the delayed feed-backed clock signal fb_clkd, output signals of the first and the second phase detectors 623 and 625 are in a logic high level. As a result, the first and the second NMOS transistors 629 and 631 are turned on; and, thus, the clock selection signal clk_sel becomes in a logic high level. Therefore, the multiplexer 314 shown in FIG. 3 selects the falling edge clock signal fclk in response to the clock selection signal which is in a logic high level. Except in the above-mentioned case, the multiplexer selects the rising edge clock signal rclk.
As described above, the DLL in accordance with the present invention can reduce a physical length of a delay line by using the clock multiplexing unit 310 . Therefore, the DLL can reduce a required time for delay locking a clock signal. In addition, a power consumption of the DLL can be reduced since a physical length of a delay line is reduced.
The present application contains subject matter related to Korean patent application No. 2004-49848, filed in the Korean Patent Office on Jun. 30, 2004, the entire contents of which being incorporated herein by reference.
While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. | An apparatus for adjusting a clock signal, including: a clock multiplexing unit for receiving an external clock signal, an external clock bar signal and a feed-backed clock signal in order to select one of the external clock signal and the external clock bar signal as an output signal of the clock multiplexing unit based on a result of comparing a phase of the external clock signal with a phase of the feed-backed clock signal; and a delay locked loop (DLL) for generating a duty corrected clock signal and the feed-backed clock signal in response to the output signal of the clock multiplexing unit. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of application Ser. No. 10/357,669, filed Feb. 4, 2003; which is a continuation of application Ser. No. 09/669,358, filed Sep. 26, 2000 (herein incorporated by reference) now U.S. Pat. No. 6,559,158; which is a continuation-in-part of application Ser. No. 09/120,703, filed Jul. 22, 1998 (herein incorporated by reference) now U.S. Pat. No. 6,274,591; which is a continuation-in-part of application Ser. No. 08/962,742, filed Nov. 3, 1997, now U.S. Pat. No. 5,972,954 the disclosures of which are herein incorporated by reference. This application also claims priority of provisional Application No. 60/168,480, filed Dec. 1, 1999, also herein incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Partial funding of the work described herein was provided under M01 RR00055 awarded by the U.S. Public Health Service General Clinical Research Center, and the U.S. Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] The present invention is directed to the treatment of certain side effects associated with the use of opioids as analgesics. In particular, the present invention is directed to treating opioid-induced inhibition of gastrointestinal motility and constipation in patients chronically administered opioids.
[0004] Opioids are effective analgesics. However, their use is associated with a number of undesirable side effects, particularly when use is prolonged or chronic. Such side effects include pruritus, dysphoria, urinary retention, and inhibition of gastrointestinal motility. Opioids are widely used long-term to treat pain in advanced cancer patients, or patients in methadone maintenance treatment programs, for example. Opioid-induced changes in gastrointestinal motility are almost universal when these drugs are used long term, and there is no evidence of gastrointestinal compensation mechanisms. Constipation is the most common chronic side effect of opioid pain medications in patients with metastatic malignancy, and can be severe enough to limit opioid use or dose. Common treatments of bulking agents and laxatives have limited efficacy and may be associated with adverse side effects such as electrolyte imbalances. The significant negative impact on the quality of life of these patients has received insufficient attention in the past from the medical community in general, and from the oncology community in particular.
[0005] One treatment that has been used for opioid side effects is the use of opioid antagonists which cross the blood-brain-barrier, or which are administered directly into the central nervous system. Opioid antagonists such as naltrexone and naloxone have been administered intramuscularly or orally to treat opioid induced side effects. Naltrexone and naloxone are highly lipid soluble and rapidly diffuse across biological membranes, including the blood-brain barrier. Therefore, although naltrexone, naloxone, nalmefene, and other opioid antagonists may reverse many opioid side effects, because they diffuse into the central nervous system they have a narrow therapeutic window before they are observed to reverse the desired analgesic effect of the opioid being used. Additionally, in methadone maintenance patients, these tertiary compounds may also induce opioid withdrawal symptoms.
[0006] Many quaternary amine opioid antagonist derivatives do not reduce the analgesic effect of opioids. These quaternary amine opioid antagonist derivatives, which have a relatively higher polarity and reduced lipid solubility when compared to the tertiary forms of the drugs, were specifically developed to not traverse the blood-brain barrier or to traverse it at a greatly reduced rate. Methylnaltrexone (MNTX) is a quaternary ammonium opioid receptor antagonist that does not cross the blood-brain barrier in humans (see, e.g., U.S. Pat. No. 4,176,186, herein incorporated by reference). It offers the therapeutic potential to reverse undesired side effects of opioid pain medications mediated by peripherally located receptors (e.g., in the gastrointestinal tract) while sparing opioid effects mediated by receptors in the central nervous system, most importantly, analgesia.
[0007] However, high levels of MNTX in the plasma can lead to undesirable side effects such as orthostatic hypotension. Furthermore, high doses of opioid derivatives such as the tertiary and quaternary derivatives discussed above can be expensive.
[0008] It is therefore clear that there is a need to enhance palliative care in terminal cancer patients and others. It is also clear that a method for the prevention of opioid-induced and inhibition of gut motility constipation which does not counteract the analgesic effects of the opioid, or risk increased levels of pain is needed. Ideally, such a treatment has few side effects and is economical because administration of small amounts is effective.
SUMMARY OF THE INVENTION
[0009] The methods of the invention address the particular needs of patients undergoing long-term or chronic opioid administration. The quaternary derivatives used in this group of patients induce Taxation and relieve the side effects and intestinal immobility caused by opioid use at surprisingly low doses, enhancing the patient's quality of life, maintaining analgesic efficacy, reducing health risks associated with opioid side effects, and reducing possible quaternary derivative side effects and costs.
[0010] “Long-term” opioid use or administration is intended to mean periods over about one week, and “chronic” use would generally mean a longer period wherein the patient is receiving an oral dose between 30 and 100 mg/day of methadone (or a dose of another opioid which is a morphine equivalent dose of between 30 and 100 oral mg/day of methadone). More preferably the patient is receiving an oral dose between 41 and 100 mg/day of methadone (or a dose of another opioid which is a morphine equivalent dose of between 41 and 100 oral mg/day of methadone).
[0011] Certain aspects of the invention include the method as above, wherein Taxation is achieved within 24 hours. In a one embodiment of the invention, the Taxation is achieved within 10 hours. Some aspects of the invention include administering a quaternary derivative of noroxymorphone orally in an amount between 0.3 and 3.0 mg/kg per day.
[0012] Another aspect of the invention includes the method as above wherein the quaternary derivative of noroxymorphone is not enteric coated. Yet another aspect of the invention includes the method as above wherein the quaternary derivative of noroxymorphone is enteric coated. In a preferred embodiment the quaternary derivative of noroxymorphone is methylnaltrexone.
DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a flow diagram of participant screening, randomization and follow-up.
[0014] [0014]FIG. 2 shows a relationship between effective methylnaltrexone dose and peak plasma concentration in chronic methadone subjects. Peak plasma concentration ([C]max) is expressed as a function of methylnaltrexone dose that induced Taxation response on first day administration (▴) and second day administration (). Subject 13 failed to defecate at the maximum dose (0.365 mg/kg) on day one (x) but did respond to the same dose on day two (+). The r 2 value for the linear regression of concentration on effective dose is 0.77.
[0015] [0015]FIG. 3 shows changes in individual oral-cecal transit time of chronic methadone subjects. (A) The transit time (ordinate) of 11 subjects in placebo group from baseline to after placebo injection (abscissa). (B) The transit time (ordinate) of 11 methadone subjects in methylnaltrexone (MNTX) group from baseline to after study drug administration (abscissa). The heavy line represents the mean. The average change in the methylnaltrexone group was significantly greater than the average change in the placebo group (P<(0.001).
[0016] [0016]FIG. 4 shows changes in individual oral-cecal transit times (ordinate) of 12 chronic methadone subjects after placebo and three oral methylnaltrexone doses (4 subjects in each dose group). Filled squares represent mean values.
[0017] [0017]FIG. 5 is a comparison of oral-cecal transit times of normal volunteers and methadone maintenance subjects showing the increased responsiveness of chronic opioid patients to MNTX. At doses ranging from 2.1 mg/kg to 6.4 mg/kg, normal subjects experienced about a 15-20% reduction in oral-cecal transit time, while at a dose of 3.0 mg/kg, methadone subjects experienced a greater than 35% reduction in oral-cecal transit time.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is directed to methods for preventing and treating the inhibition of gastrointestinal motility, particularly constipation, that arises in the group of patients taking chronic or maintenance doses of opioids. These patients include late stage cancer patients, elderly patients with osteoarthritic changes, methadone maintenance patients, neuropathic pain and chronic back pain patients. It has been discovered that the group of patients chronically taking opioids is surprisingly responsive to doses of quaternary derivatives of noroxymorphone that were previously considered too low to be clinically efficacious. Treatment of these patients is important from a quality of life standpoint, as well as to reduce complications arising from chronic constipation, such as hemorrhoids, appetite suppression, mucosal breakdown, sepsis, colon cancer risk, and myocardial infarction.
[0019] In the invention, a preferred quaternary derivative of noroxymorphone is methylnaltrexone. Preferred side effects to be treated include constipation and gastrointestinal motility inhibition, dysphoria, pruritus, and urinary retention.
[0020] When used as a treatment for these opioid-induced side effects, methylnaltrexone (MNTX) or other quaternary derivatives of noroxymorphone (QDMN) provide prolonged relief of the side effects. Idiopathic constipation, i.e., that due to causes other than exogenous administration of opioids, may be mediated by opioid sensitive mechanisms. Endogenous opioid receptors have been identified in the gut and these receptors may modulate gut motility. Thus, administration of an opioid antagonist with peripheral action, such methylnaltrexone or other quaternary derivatives of noroxymorphone, would block the effects of endogenous opioids.
[0021] Quaternary derivatives of noroxymorphone are described in full in Goldberg et al., U.S. Pat. No. 4,176,186 (herein incorporated by reference), and in general are represented by the formula:
[0022] wherein R is allyl or a related radical such as chlorallyl, cyclopropyl-methyl or propargyl, and X is the anion of an acid, especially a chloride, bromide, iodide or methylsulfate anion.
[0023] The presently preferred quaternary derivative of noroxymorphone is methylnaltrexone. Methylnaltrexone is a quaternary amine derivative of naltrexone. Methylnaltrexone has been found to have only 2 to 4% of the opiate antagonistic activity of naltrexone in vivo due to its inability to pass the blood-brain-barrier and bind to the opiate receptors in the central nervous system.
[0024] Opioids are typically administered at a morphine equivalent dosage of. 0.005 to 0.15 mg/kg body weight for intrathecal administration; 0.05 to 1.0 mg/kg body weight for intravenous administration; 0.05 to 1.0 mg/kg body weight for intramuscular administration; 0.05 to 1.0 mg/kg body weight/hour for transmucosal or transdermal administration. By “morphine equivalent dosage” is meant representative doses of other opioids which equal one milligram of morphine, for example 10 mg meperidine, 1 mg methadone, and 80 μg fentanyl.
[0025] In accordance with the present invention, methylnaltrexone is administered at a dosage of: 0.001 to 1.0 mg/kg body weight for intravenous administration; 0.001 to 1.0 mg/kg body weight for intramuscular administration; 0.001 to 1.0 mg/kg body weight for transmucosal administration and 0.1 to 40.0 mg/kg body weight for oral administration.
[0026] The administration of the methylnaltrexone is preferably commenced prior to administration of the opioid to prevent opioid-induced side effects, including constipation. It is desirable to commence administration of methylnaltrexone about 5 minutes for parenteral MNTX administration and 20 minutes for enteral MNTX administration prior to administration of opioids in order to prevent these opioid-induced side effects, While the prevention of symptoms is preferred, in some patients, such as those chronically on opioids, prevention is not possible. However, methylnaltrexone administration may also be commenced after the administration of the opioid or after the onset of opioid induced symptoms as a treatment for those symptoms.
[0027] Methylnaltrexone is rapidly absorbed after oral administration from the stomach and bowel. Initial plasma levels of the drug are seen within 5-10 minutes of the administration of non-enteric coated compound. Addition of an enteric coating which prevents gastric absorption is associated with lower plasma levels of the methylnaltrexone.
[0028] For intravenous or intramuscular administration, methylnaltrexone (from, e.g., Mallinckrodt Pharmaceuticals, St. Louis, Mo.) is formulated with saline or other physiologically acceptable carriers; for transmucosal administration the methylnaltrexone is formulated with a sugar and cellulose mix or other pharmacologically acceptable carriers known in the art; and for oral administration, the methylnaltrexone is provided in granules which can be coated or left uncoated, and can be put in gelatin capsules. An enteric coating manufactured by Coating Place, Inc., Verona, Wis. can be made as follows. The drug was prepared by encapsulating MNTX powder with a Eudragit L100 and Myvacet 9-45 mixture. The final substance used in the study was the 45-80 mesh fraction which was 50% MNTX by weight. This was demonstrated to decrease release of the drug at gastric pH by 77% based on the methods of the USP/NF. These microencapsulated granules were then put into gelatin capsules for administration. Alternatively, methylnaltrexone is formulated with pharmacologically acceptable binders to make a tablet or capsule with or without an enteric coating. Methods for such formulations are well known to those skilled in the art (see e.g., Remington: The Science and Practice of Pharmacy, 19 th ed. (1995) Mack Publishing Company, Easton, Pa.; herein incorporated by reference).
[0029] Any art-known transdermal application may be used, but transdermal administration is preferably via a patch applied to the skin with a membrane of sufficient permeability to allow diffusion of MNTX at a fixed rate in the range of 1.0 to 10.0 mg/hr. The rate of administration may be varied by varying the size of the membrane contact area and/or applying an electrical wiring potential to a drug reservoir. The patch preferably holds 25 mg to 1 gram of available drug in the reservoir plus additional drug as needed for the mechanics of the system.
[0030] In the description above and below, methylnaltrexone is used as an example of a particularly effective QDNM. It is apparent that other QDNMs may be used as desired, and appropriate dosage can readily be determined empirically by those of skill in the art to account for e.g., variable affinity of the QDNM for opiate receptors, different formulations, etc.
[0031] The following Examples are intended to illustrate aspects of the invention and are not to be construed as limitations upon it.
EXAMPLE 1
Effects of Standard MNTX Dosage on Chronic Opioid Patients
[0032] Subjects
[0033] With approval from the Institutional Review Board at the University of Chicago, two male and two non-pregnant female adults participating in a methadone maintenance program were enrolled in this study. All four subjects were African Americans. Their mean age ±SD (range) was 45.3±8.6 (35-56) years.
[0034] Subjects in this study met the following inclusion criteria: (1) They were currently enrolled in a methadone maintenance program for at least 1 month; (2) they experienced methadone-induced constipation, i.e. less than one bowel movement in the previous 3 days or less than three bowel movements in the previous week (O'Keefe et al., J Gerontol., 50:184-189 (1995); Parup et al., Scand. J Gastroenterol, 33:28-31 (1998)). Exclusion criteria were as follows: (1) History or current evidence of significant cardiovascular, respiratory, endocrine, renal, hepatic, hematological or psychiatric disease; (2) any laboratory findings indicating hepatic or renal impairment, or abnormal physical examination findings; (3) current use of other medications, or evidence of illicit drug use; (4) known hypersensitivity to lactose or lactulose; (5) participation in any investigational new drug study in the previous 30 days; (6) subject is breastfeeding. Subjects also agreed not to take any laxatives for 2 days before the beginning of the study and during the study.
[0035] Protocol
[0036] After obtaining written, informed consent, subjects were admitted to the Clinical Research Center at the University of Chicago Medical Center for up to 8 days. Methylnaltrexone dose of 0.45 mg/kg was chosen to start this trial because this dose was previously given in normal volunteers and prevented opioid-induced delay of the oral-cecal transit time without any side effects (Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996)). Drug administration was performed single blind to the subjects in this pilot study. Thus, methylnaltrexone dose could be adjusted based on subjects' clinical response during the study.
[0037] All four subjects received test drug (normal saline or methylnaltrexone (N-methylnaltrexone bromide, prepared by Mallinckrodt Specialty Chemicals, St. Louis, Mo.)) twice daily at 09:00 h and 21:00 h, except on the last day of the study in which they received test drug only at 09:00 h. All four subjects received placebo (normal saline) on Day 1. Thereafter, subjects received intravenous methylnaltrexone until the end of the study.
[0038] On Day 2 at 09:00 hours (h), Subjects 1 and 2 were given 0.45 mg/kg intravenous methylnaltrexone over 1 min. Subject 2 experienced severe abdominal cramps after receiving the compound and was withdrawn from the study. Subject 1 did not experience abdominal cramps after the first dose of methylnaltrexone, but was given placebo in place of the compound at the regularly scheduled dosing times for Day 2 and Day 3 to maintain the single blind study while the reaction of Subject 2 was investigated. Beginning on Day 4, the study was resumed for Subject 1 using 0.45 mg/kg of methylnaltrexone, diluted with 50 ml normal saline and administered over 30 min. Infusion could be stopped at any time for complaints of abdominal pain.
[0039] For Subjects 3 and 4, the study was shortened from 8 to 5 days, methylnaltrexone dosage was decreased, and a new, three-step dosing procedure was established. Methylnaltrexone 0.05 mg/kg, mixed in 30 ml normal saline (first syringe), was infused intravenously over 10 min. The subject was then observed 10 min for drug response. If there was no response, then methylnaltrexone 0.1 mg/kg (second syringe), mixed in 30 ml normal saline, was infused over 15 min. Subject was observed 15 min for drug response. If there was no response, then methylnaltrexone 0.3 mg/kg (third syringe), mixed in 30 ml normal saline, was infused over 15 min.
[0040] Vital signs were obtained at 0, 5, 10, 30, 60, 90 and 120 min after each test drug administration. For oral-cecal transit time measurement, 10 g lactulose (Solvay Pharmaceuticals, Marietta, Ga.) was administered orally at 09:00 h of Day 1, Day 5 and Day 8 for Subject 1; of Day 1 for Subject 2 and of Day 1, Day 3 and Day 5 for Subjects 3 and 4. Illicit drug use was monitored by random urine drug screens.
[0041] Blood and Urine Sampling and Analysis, Bowel Function Assessment
[0042] After each test drug administration, seven blood samples (5 ml each) were obtained at time 0, 5, 30 min, and 1, 2, 4, 8 h, and three urine samples were collected at time 0, 2, and 4 h. Plasma and urine methylnaltrexone levels were determined by an HPLC technique with a detection limit of 2 ng/ml (Kim et al., 1989; Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996); both herein incorporated by reference). Subjects were asked to record frequency and consistency of stools during the study period. Subjects' bowel movements were witnessed and recorded by a research nurse.
[0043] Oral-Cecal Transit Time Measurement
[0044] The oral-cecal transit time was assessed by the pulmonary hydrogen (H 2 ) measurement technique, which measures pulmonary H 2 that is produced when unabsorbed lactulose is fermented by colonic bacteria and excreted in the breath. This H 2 production is reflected by a concomitant increase in breath H 2 excretion. The time between ingestion and the earliest detectable and sustained rise in pulmonary hydrogen excretion, i.e., a sudden rise to peak (>25 ppm), or an increase of at least 2 ppm above the baseline, maintained and increased in three consecutive samples, indicates that lactulose has reached the cecum and represents the oral-cecal transit time (see e.g., Yuan, et al., Clin. Pharmacol Ther., 59:469-475) (1996); Bond and Levitt, J. Lab Clin. Med, 85:546-555 (1975); Read, et al., Gut., 26:834-842 (1985) Bailisco, et al, Dig. Dis. Sci., 32:829-832 (1987)). Hydrogen breath tests were conducted every 15 min until oral-cecal transit time was determined.
[0045] Evaluation of Central Opioid Withdrawal
[0046] To evaluate possible opioid withdrawal with methylnaltrexone, subjects were asked to rate on a 5-point scale from 0 (not at all) to 4 (extremely) an objective checklist Withdrawal Scale (Fraser et al., J. Pharmacol Exp. Ther, 133:371-387 (1961); Jasinski, Drug Addiction J., 197-258 (1977); both herein incorporated by reference). Items to be rated were: muscle cramps, flushing, painful joints, yawning, restless, watery eyes, runny nose, chills or gooseflesh, sick to stomach, sneezing, abdominal cramps, irritable, backache, tense and jittery, sweating, depressed/sad, sleepy, shaky (hands), hot or cold flashes, and bothered by noises. The ratings for individual items were summed for a total score for each scale. The total scores were compared before and after methylnaltrexone administration to see if there was a significant difference.
[0047] Results
[0048] All four subjects showed no response to placebo injection. Subjects 1 and 2, who received a methylnaltrexone dose of 0.45 mg/kg, showed immediate positive Taxation during or immediately after intravenous drug infusion. During 7 days of methylnaltrexone administration, Subject 1 did not experience any significant side effects, and reported mild abdominal cramping after each injection. Subject 2, however, had severe abdominal cramping after a single dose of methylnaltrexone, but showed no signs of systemic withdrawal such as lacrimation, diaphoresis, mydriasis, or hallucinations. Subject 2 was released without receiving additional methylnaltrexone.
[0049] Subjects 3 and 4 received intravenous methylnaltrexone (0.05-0.15 mg/kg) twice daily for 4 consecutive days. This 0.05-0.15 mg/kg dose range induced immediate Taxation response in these two subjects, therefore, the third syringe injection (methylnaltrexone dose 0.3 mg/kg dose) was not administered during the study. No significant side effects were observed. Like Subject 1, both subjects described mild abdominal cramping, similar to a defecation sensation, without discomfort involved.
[0050] The stool frequency of these subjects increased from 1-2 times per week before the study to approximately 1.5 stool per day during the treatment period (Table 1). For Subjects 1, 3, and 4, oral-cecal transit times were reduced from 150, 150 and 150 min (after placebo) to 90, 60 and 60 min (after methylnaltrexone, at the end of the study), respectively. The baseline transit time for Subject 2 was 180 min. Due to the discontinuation of this subject, no other transit time was recorded after Day 1.
[0051] Peak plasma methylnaltrexone levels for Subjects 1, 2, 3 and 4 were 1.65, 1.10, 0.25 and 0.53 μg/ml, respectively.
TABLE 1 Intravenous methylnaltrexone reverses chronic-opioid induced gut motility and transit time changes in methadone subjects. Stool Intravenous frequency Central Oral methadone methylnaltrexone Laxation Before study Methylnaltrexone Abdominal opioid Subject (mg/day) (mg/kg) response (per week) (per day) cramping withdrawal #1 70 0.45, bid Immediate 1 1.5 Mild No #2 38 0.45 Immediate 2 1 Severe No #3 80 0.05-015, bid Immediate 2 1.3 Mild No #4 65 0.05-0.15, bid Immediate 1.5 2 Mild No
[0052] Discussion
[0053] In previous healthy volunteer studies, intravenous 0.45 mg/kg methylnaltrexone effectively prevented opioid-induced delay in oral—cecal transit time without affecting analgesia (Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996)). However, that study was performed in normal volunteers after acute single administration doses of opioid and methylnaltrexone. Thus, the dose relationship of agonist to antagonist remained unknown in opioid-tolerant individuals, such as subjects in methadone maintenance programs as well as advanced cancer patients with chronic opioid pain medications.
[0054] When this study was designed, 0.45 mg/kg intravenous methylnaltrexone was chosen, the dose previously administered in normal volunteers that did not cause gastrointestinal symptoms (e.g. abdominal cramping) or Taxation response. To achieve positive Taxation while limiting the possibility of adverse effects, BID dosing was planned for 7 days. Due to the fact that the elimination half-life of intravenous methylnaltrexone is approximately 2 h (Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996); Foss et al., J Clin. Pharmacol, 37:25-30 (1997)), no drug accumulation was expected in this study.
[0055] After intravenous injection, immediate bowel movements were observed in the first two subjects. While methylnaltrexone has been demonstrated to not reverse the analgesic effects of opioids (Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996)), the potential effects of the compound in a population of chronic opioid users was unknown. Gastrointestinal symptoms are one of the hallmarks of gut withdrawal, and the persistent severe cramping in Subject 2, which required treatment, prompted a modification of the protocol. It is important to note, however, that none of the other primary indicators of opioid withdrawal were noted in this or any of the other subjects. For the next two subjects, the drug dose was reduced and the study duration shortened. While no effects were observed after placebo, positive Taxation and significant reduction of the gut transit time were observed after a lower intravenous dose of methylnaltrexone in these two chronic methadone subjects.
[0056] Peak plasma levels of methylnaltrexone in all subjects were determined and were comparable to those seen in volunteers given similar doses (Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996); Foss et al., J Clin. Pharmacol, 37:25-30 (1997)). Subject 1, who had Taxation but no other symptoms actually had higher peak plasma levels than Subject 2 (with the severe abdominal cramping), suggesting a difference in Subject 2's pharmacological response rather than a difference in pharmacokinetics.
[0057] The three subjects who completed the study reported mild abdominal cramping during intravenous methylnaltrexone infusion. The mild cramping appears to be a physiological desire to move the bowels, because the cramping disappeared after their bowel movement. Since the half-life of methylnaltrexone is approximately 2 h, one would expect that cramping caused by hyperactivity of the gut to be more prolonged. This indicates that methylnaltrexone and similar QDNMs are safe and ideal candidates to resolve opioid induced constipation without stimulant/laxative type side effects.
EXAMPLE 2
Effects of Variable MNTX Dosage on Chronic Opioid Patients
[0058] This Example was a double-blind, randomized, placebo-controlled trial, evaluating the effects of methylnaltrexone in treating chronic opioid-induced constipation. We conducted this trial using subjects in a methadone maintenance program, in which approximately 60% of the chronic methadone users have constipation. These subjects served as a proxy group for advanced cancer patients to evaluate the efficacy of methyl naltrexone on chronic opioid-induced constipation.
[0059] With approval from the Institutional Review Board, 9 male and 13 non-pregnant, non-breastfeeding female adults were enrolled (FIG. 1). Their mean age±S.D. (range) was 43.2±5.5 (25-52) years. Subjects met the following inclusion criteria: (1) Enrollment in a methadone maintenance program for >1 month; (2) Methadone-induced constipation, i.e., 0-1 bowel movement in the previous three days, or 0-2 bowel movements in the previous week; (3) No laxative use two days before the study nor during the study. Exclusion criteria were as in the previous Example.
[0060] Protocol
[0061] An investigator explained the study procedures and obtained written, informed consent from 22 paid subjects. These subjects, who continued to receive their usual dose of methadone during the study, were admitted to the Clinical Research (Center at the University of Chicago Medical Center for two days. An intravenous catheter was placed in each arm, one for test drug administration (placebo or methyl naltrexone [N-methylnaltrexone bromide], prepared by Mallinckrodt Specialty Chemicals, St. Louis, Mo.), and the other for blood drawing.
[0062] On Day 1, at 9 AM, after a restricted supper of no fiber the night before (required for the oral-cecal transit time measurement, see below) and overnight fasting, subjects were instructed to ingest 10 g lactulose (Solvay Pharmaceuticals, Marietta, Ga.) in 1.00 ml tap water. Subjects were also given placebo (normal saline) in four syringes (35 ml each) for intravenous injection (single-blinded to the subject).
[0063] On Day 1, at 5 PM, subjects were given placebo or methylnaltrexone up to 0.365 mg/kg over four syringes. Each syringe contained placebo or methylnaltrexone in 35 ml of normal saline, and was administered intravenously over nine minutes. For the methylnaltrexone group, syringes 1, 2, 3 and 4 contained 0.015, 0.05, 0.1 and 0.2 mg/kg study drug, respectively. The interval between administration of each syringe in both groups was one minute. The continued administration of each syringe depended on the absence of a clinical Taxation response (i.e., elimination of any stool) and/or potential side effects. Immediate Taxation was defined as defecation either during or within one minute after cessation of the infusion. The injection was discontinued if the subject had a bowel movement.
[0064] After a non-fiber supper the night before and overnight fasting, subjects on Day 2 at 9 AM, were again given test drug intravenously. Subjects were also given 10 g lactulose at this time. Day 2 studies were done to test the constancy of effect and to measure the oral-cecal transit time; this study did not have a crossover design.
[0065] Injection assignment was prepared using a table of random numbers from which sealed envelopes were prepared and opened sequentially as subjects were enrolled in the study. No stratification or blocking factors were used, except to insure that equal numbers of subjects were assigned to each treatment group after enrollment of the last (22 nd ) subject. Randomization and test drug preparation were done by a biostatistician and a physician, respectively, who did not participate in data acquisition and evaluation.
[0066] Vital signs were obtained at 0, 5, 10, 30, 60, 90 and 120 min after each test drug administration. Illicit drug use was monitored by random urine drug screens.
[0067] Blood and Urine Sampling and Analysis
[0068] Blood and urine sampling and analysis were performed as in Example 1.
[0069] Bowel Function Assessment
[0070] Subjects were asked to record frequency and consistency of stools during the study period. Subjects' bowel movements were confirmed and recorded by a research nurse blinded to the group assignment. At the end of the study, the subjective opinion of each participant was gathered in order to rate subjects' satisfaction in respect to bowel movement.
[0071] Oral-Cecal Transit Time Measurement
[0072] The oral-cecal transit time was assessed as in Example 1.
[0073] Evaluation of Central Opioid Withdrawal
[0074] To evaluate possible opioid withdrawal with methylnaltrexone, before and 10 min after the completion of test drug administration, subjects were asked to complete an objective checklist of withdrawal symptoms modified from Fraser et al. ( J. Pharmacol Exp. Ther., 133:371-387 (1961)) and Jasinski (Drug Addiction J, 197-258 (1977)). Items rated (none, mild, moderate, severe) were yawning, lacrimation (excessive tearing) rhinorrhea (nasal discharge), perspiration, tremor, piloerection (goosebumps), and restlessness. The ratings for individual items were translated to a 0-3 scale and summed to give a total symptom score. The total scores before and after test drug administrations were compared between the groups. Potential opioid withdrawal symptoms were also monitored by an investigator throughout the study.
[0075] Statistical Analysis
[0076] Laxation responses were compared between groups using Fisher's exact test. The Mann-Whitney U test was used to compare the change from baseline in oral-cecal transit time between the two groups and to evaluate statistical differences between genders in oral-cecal transit times with P<0.05 considered statistically significant. Changes in opioid withdrawal symptoms were analyzed similarly.
[0077] Results
[0078] The mean stool frequency per week of the 22 subjects before the study was 1.5±0.7. All 22 subjects showed no response to placebo in the morning of Day 1. Eleven subjects were randomized to each treatment group. Those randomized to placebo received all four syringes in Day 1 afternoon and Day 2 morning sessions. As shown in Table 2, none of them showed any Taxation response after placebo, and no abdominal cramping was reported. At the end of the trial, seven of them were disappointed in respect to bowel movement satisfaction. There were no significant bowel movement frequency changes before and during the study. There were no opioid withdrawal and no significant side effects in these subjects.
[0079] Ten subjects in the methylnaltrexone group had immediate Taxation response in the Day 1 afternoon session, and all 11 subjects had immediate Taxation in the Day 2 morning session (Fisher's exact P value <0.0001 when compared with placebo group response for both Days 1 and 2). The stool of most subjects (over 90%) was soft to loose and in large quantity. The methylnaltrexone dose received was 0.09±0.10 (0.01-0.37) mg/kg and 0.10±0.10 (0.01-0.37) mg/kg for Day 1 and Day 2, respectively. FIG. 2 shows the relationship between effective methylnaltrexone dose and peak plasma concentration.
[0080] During and immediately after each study drug injection, all subjects reported mild to moderate abdominal cramping, which they described as being similar to a defecation sensation, without discomfort involved. There was no opioid withdrawal symptoms observed in any of these subjects during the study. No significant side effects were reported by the subjects. Subject 13 reported mild light-headedness which resolved spontaneously. No subject demonstrated any clinically significant change in blood pressure or heart rate from baseline with either the placebo or study drug infusions. Subjects did not have additional bowel movements after drug-induced-immediate Taxation, except Subject 15 who reported mild diarrhea. At the end of the study, all 11 subjects were satisfied with their bowel movement activity (Table 2).
TABLE 2 Methylnaltrexone (MNTX) reverses chronic opioid constipation in methadone subject. Oral Day One Day Two Bowel Subject Methadone Test Drug Laxation Test Drug Laxation movement Number (mg/day) (mg/kg) Response (mg/kg) Response Satisfaction 1 50 Placebo No Placebo No Disappointed 2 65 Placebo No Placebo No Disappointed 4 85 Placebo No Placebo No Disappointed 5 61 Placebo No Placebo No Disappointed 8 42 Placebo No Placebo No Disappointed 11 89 Placebo No Placebo No (not available) 14 85 Placebo No Placebo No Disappointed 16 50 Placebo No Placebo No Satisfied 18 50 Placebo No Placebo No Disappointed 19 75 Placebo No Placebo No (not available) 22 50 Placebo No Placebo No Somewhat satisfied 3 55 MNTX 0.015 Immediate MNTX 0.015 Immediate Very satisfied 6 59 MNTX 0.065 Immediate MNTX 0.065 Immediate Very satisfied 7 68 MNTX 0.165 Immediate MNTX 0.165 Immediate Very satisfied 9 65 MNTX 0.065 Immediate MNTX 0.115 Immediate Satisfied 10 30 MNTX 0.065 Immediate MNTX 0.065 Immediate Very satisfied 12 45 MNTX 0.075 Immediate MNTX 0.115 Immediate Very satisfied 13 100 MNTX 0.365 No MNTX 0.365 Immediate Somewhat satisfied 15 40 MNTX 0.065 Immediate MNTX 0.055 Immediate Very satisfied 17 50 MNTX 0.050 Immediate MNTX 0.095 Immediate Somewhat satisfied 20 85 MNTX 0.025 Immediate MNTX 0.040 Immediate Very satisfied 21 75 MNTX 0.011 Immediate MNTX 0.013 Immediate Very satisfied
[0081] Oral-cecal transit time data are presented in FIG. 3. The transit times for subjects in the placebo group (n=11) at baseline and after placebo injection were 126.8±48.3 (60-195) min and 125.3±45.0 (60-180) min, respectively. The transit times for subjects in the methylnaltrexone group (n=11) showed that the study drug reduced the transit time from the baseline level of 132.3±36.0 (60-180) min to 54.5±19.3 (30-105) min. The average change in the methylnaltrexone group (−77.7±37.2 min) was significantly greater than the average change in the placebo group (1.4±12.0 min) (P<0.001). There were no statistical differences in oral-cecal transit times between genders.
[0082] Peak plasma levels of 11 subjects in methylnaltrexone group for Day 1 and Day 2 were 162±237 (30-774) ng/ml and 166±177 (33-658) ng/ml, respectively. The percentage of the intravenous dose excreted, unchanged in urine from 0 to 4 hr for Day 1 and Day 2 was 23.7 10.5 (9.6-39.9) % and 37.6±17.8 (13.2-73.6) %, respectively.
[0083] Discussion
[0084] The effect of opioids on gastrointestinal motility and transit is well appreciated as a clinical phenomenon. Opioids inhibit gastric emptying and propulsive motor activity of the intestine, thereby decreasing the rate of intestinal transit and producing constipation. It has been shown that opioid receptors and endorphins are widely distributed in the central nervous system and throughout the gastrointestinal tract. Based on data obtained from previous animal experiments, the site of opioid action (central vs. peripheral) of exogenous opioid-induced gut motility change or constipation is still controversial (Daniel, et al., Gastroenterology, 36:510-523 (1959); Stewart, et al., J. Pharmacol Exp. Ther., 205: 547-555 (1978); Tavani, et al., Life Sci., 27:2211-2217 (1980); Galligan and Burks, J Pharmacol Exp. Ther., 226:356-361 (1983); Manara, et al., J. Pharmacol Exp. Ther., 237:945-949 (1986)). Since the translation of animal experiment data in the literature to humans is problematic due to differences in the physiology of the opioid systems, the action site for opioid-induced constipation in humans remains a matter of investigation. Methylnaltrexone, a peripheral opioid receptor antagonist, very effectively reversed chronic opioid constipation in this clinical trial. The data in these examples provide the first strong evidence that the methadone constipating effect in humans is predominantly mediated by receptors located in the peripheral gastrointestinal tract.
[0085] All 11 subjects who received intravenous methylnaltrexone had an immediate Taxation response, and all reported some degree (mild to moderate) of abdominal cramping prior to their bowel movement. We interpret their abdominal cramping as a physiological desire to defecate, because the cramping disappeared after their bowel movement. Because the half-life of methylnaltrexone is approximately two hours, one would expect that cramping caused by hyperactivity of the gut to be much more prolonged.
[0086] The lactulose hydrogen breath test was used, and subjects always received placebo the morning of Day 1 to establish an oral-cecal transit time baseline. Compared to baseline levels, we observed a significant reduction in gut transit time in all subjects after methylnaltrexone treatment. This result is consistent with the methylnaltrexone-induced clinical Taxation response in these individuals. Lactulose, a non-absorbable osmotic agent that acts in the colon by increasing water content of the stool without directly stimulating gut peristaltic activity, may have laxative effects itself and could affect interpretation of our results. However, the dose used in this study (10 g) is ½ to ⅓ of a single dose and ⅙ th {fraction (1/12)} th the daily dose recommended to produce soft stools. This small dose of lactulose had no effect in our study, as indicated by the absence of a Taxation response as well as no change in oral-cecal transit time in the placebo group.
[0087] A relatively wide dose range of intravenous methylnaltrexone was used to achieve clinical Taxation. In terms of individual subjects, however, the Taxation doses for Day 1 and Day 2 were very similar, and no tachyphylaxis was noticed. In this study, no opioid withdrawal symptoms were observed in our chronic methadone subjects, which further indicates that methylnaltrexone does not penetrate into the brain in humans. None of the 11 subjects in the methylnaltrexone group experienced significant side effects.
EXAMPLE 3
Effects of Oral Administration of MNTX on Chronic Opioid-Induced Constipation
[0088] Since oral medication is a safer and more convenient way to deliver drugs than is intravenous administration, the efficacy of oral MNTX in relieving constipation in methadone maintained patients was evaluated. Twelve constipated adults (≦2 stool/week) were enrolled. Their daily methadone dose was 73.3±16.2 mg (41-100 mg), mean±SD (range). On day 1 at 9 AM, subjects ingested 10 g lactulose (Solvay Pharmaceuticals) to assess oral-cecal transit time as described above, and a placebo capsule. On day 2 at 9 AM, subjects again received lactulose, and a capsule containing methylnaltrexone (Mallinckrodt). Ascending oral methylnaltrexone doses (0.3, 1.0, and 3,0 mg/kg) were given to 3 groups of 4 subjects per group. Drug administrations were single-blinded to the subject. Laxation response and potential opioid withdrawal were recorded and blood samples were collected.
[0089] None of the 12 subjects showed laxation response to placebo on day 1. On day 2, 3 out of 4 subjects had a bowel movement 18.0±8.7 hr (8-24 hr) after receiving 0.3 mg/kg MNTX. All subjects in the 1.0 mg/kg group and 3.0 mg/kg group had bowel movements at 12.3±8.7 hr (3-24 hr) and 5.2±4.5 hr (1.2-10 hr) after receiving oral compound, respectively. Most subjects reported very mild abdominal cramping after oral MNTX. Bowel movements, in most cases, were loose and in large quantity. There was no opioid withdrawal in any subjects, and no adverse effects were reported. Dose-related reduction of oral-cecal transit times is shown in FIG. 4. Oral MNTX has a significant dose-response effect (p<0.05) using the Spearman rank correlation coefficient test and linear regression model. Eight subjects had undetectable methylnaltrexone in their plasma. Peak plasma level for another 4 subjects (one from 1.0 mg/kg group and three from 3.0 mg/kg group) was 17.8±6.6 ng/ml (10-26 ng/ml).
EXAMPLE 4
Effects of MNTX on Patients Administered Opioids Non-Chronically
[0090] Subjects
[0091] With approval from the Institutional Review Board at the University of Chicago, seven men and seven nonpregnant women were enrolled in this double-blind, randomized placebo-controlled study. Mean age±SD was 25.8±8.4 years: age range was 18 to 43 years. Subjects were screened for drug abuse disorders or medical contraindications that would keep them from participating in the study.
[0092] Protocol
[0093] Subjects fasted from midnight the night before the study day and were admitted for each experimental day (or session) in the morning to the Clinical Research Center at the University of Chicago Medical Center. Sessions were separated by at least 1 week. Each session lasted approximately 7 hours, and the subjects received one of three injections: (1) placebo plus placebo, (2) placebo plus 0.05 mg/kg morphine, or (3) 0.45 mg/kg methylnaltrexone plus 0.05 mg/kg morphine. Injection 1 was given at the first session, and the subjects were blinded to the medication. Injections 2 and 3 were given in a random order, and the subjects and observers were blinded to the medication. Injection assignments were prepared by random selection on a computer and were sealed in envelopes. Drug preparation and administration was done by a physician who did not participate in subject observation and data acquisition.
[0094] After completion of the above three injections, we asked six of the subjects, beginning with those who had completed the study last, to return for a fourth injection (0.45 mg/kg methylnaltrexone plus 0.1 mg/kg morphine). This was done to evaluate the effects of methylnaltrexone with a higher does of morphine.
[0095] Drugs
[0096] The following drugs were used: morphine sulfate (Elkins-Sinn, Cherry Hill, N.J.), N-methylnaltrexone bromide (Mallinckrodt Specialty Chemicals, St. Louis, Mo.), and lactulose (Duphalac, Solvay Pharmaceuticals, Marietta, Ga.).
[0097] Statistics
[0098] Results of the hydrogen breath test after different injections were analyzed with the use of the Wilcoxon matched-pairs signed-rank test, with p<0.05 considered to be statistically significant. The Mann-Whitney U test was used to evaluate statistical differences between genders in oral-cecal transit times and in cold-indicted paid scores.
[0099] Results
[0100] Two female subjects were excluded from the study after the first (placebo plus placebo) session. One of them showed a relatively high and unstable baseline H 2 peak value (12 ppm) 2 hours after drinking lactulose. H 2 production requires a colonic bacterial flora capable of fermenting carbohydrate and yielding H 2 . In in vivo studies of humans who had ingested lactulose and in vitro studies of fecal incubates with varying carbohydrates, H 2 was not produced in 2% to 27% of individuals tested.
[0101] Oral-Cecal Transit Time
[0102] Oral-cecal transit times are reported in FIG. 5. Transit time increased after morphine administration in all 12 subjects and methylnaltrexone prevented the morphine-induced delay in every subject. Morphine significantly increased oral-cecal transit time from a baseline level of 104.6±31.1 minutes (mean±SD) to 163.3±39.8 minutes p<0.01). Methylnaltrexone plus morphine did not increase transit time (106.3±39.8 minutes, not significant compared with baseline;p=0.56). Methylnaltrexone prevented 97% of morphine-induced changes in oral-cecal transit time (p<0.01 compared with morphine alone). There were not statistical differences in oral-cecal transit times between genders. Table 3 summarizes the results.
TABLE 3 Pharmacokinetic parameters for 0.45 mg/kg intravenous methylnaltrexone in 12 subjects Subject No. C max (ng/ml) AUC (ng/ml · hr) V d β (L/kg) t 1/2 β (min) CL (L/hr) F U (%) 1 3059 747 84.7 112.5 45.2 39.5 2 3119 677 82.4 106.3 46.5 40.4 3 4033 742 76.4 95.8 47.8 35.1 4 2640 658 87.7 87.5 60.1 34.0 5 2111 549 107.3 124.6 51.7 33.8 6 4309 694 166.9 162.6 61.6 36.5 7 1921 595 140.7 203.1 41.6 43.5 8 2418 637 246.9 238.1 62.2 26.6 9 5471 588 96.2 84.9 68.1 49.6 10 4076 1013 44.3 93.5 28.4 73.4 11 3443 634 139.2 114.2 73.2 44.4 12 2993 587 108.7 151.8 43.0 46.0 Mean ± SD 3299.4 ± 122.6 676.8 ± 122.6 115.1 ± 53.1 131.2 ± 48.7 52.5 ± 12.8 41.9 ± 11.8
[0103] Discussion
[0104] Humans do not appreciably de-methylate methylnaltrexone. Results from a phase I trial with eight normal volunteers showed that doses of methylnaltrexone up to 0.32 mg/kg did not cause side effects; doses of 0.64 to 1.25 mg/kg were associated with transient orthostatic hypotension (Foss et al., unpublished data, 1993).
[0105] The effect of opioids on gastrointestinal motility and transit is appreciated as a clinical phenomenon. However, the mechanism of the opioid constipating action is not fully understood. The major factors responsible include the delay of gastric emptying and changes in the motility and transit in the small intestine and the colon. Increased intestinal absorption may also contribute to morphine-induced constipation because of the change in the consistency of the stools. In this study, we observed a significant delay in oral-cecal transit time after intravenous morphine injection in human subjects and the delay was effectively antagonized by concomitant administration of methylnaltrexone. This result suggests that methylnaltrexone can reverse morphine-induced peripherally mediated effects on the gastrointestinal tract.
[0106] In the United States, approximately 500,000 patients die of cancer annually. Opioid pain medication is used in the terminal phase of care for over 50% of these patients, and constipation, a significant clinical problem, affects 40-50% (approximately 125,000) of patients with metastatic malignancy who receive opioid pain medications (Schug, et al., J. Pain & Symptom Management, 7:259-266 (1992); Wingo, et al., Ca. A Cancer J. for Clin., 45:8-30 (1995)). A significant number of hospice patients receiving chronic opioids for pain would rather endure their pain than face the severe incapacitating constipation that opioids cause.
[0107] Results described herein demonstrate that chronic methadone subjects are very sensitive to intravenous methylnaltrexone compared to normal opioid naive subjects in a previous trial, who received 0.45 mg/kg methylnaltrexone without any Taxation response (Yuan et al., Clin. Pharmacol Ther., 59:469-475 (1996)). Comparison of the results of Example 4 with Examples 1-3 demonstrates the increased responsiveness of chronic opioid patients to the effects of methylnaltrexone. Lower doses of methylnaltrexone provide constipation relief to these patients comparable to that observed in normal patients administered higher doses of methylnaltrexone. Thus, patients having increased sensitivity to methylnaltrexone, such as chronic methadone users or cancer patients receiving chronic opioids, can benefit from very low doses of methylnaltrexone to manage their opioid induced constipation. This invention can substantially improve the quality of life for terminally ill patients and others chronically using opioids.
[0108] The preceding description and Examples are intended to be illustrative. Those skilled in the art to which the invention pertains will appreciate that alterations and changes in the described protocols may be practiced without departing from the meaning, spirit, and scope of this invention. Therefore, the foregoing description should be read consistent with and as support to the following claims, which are to have their fullest and fair scope. | A method of inducing Taxation in a patient who has been chronically taking opioids, the method comprising orally administering a quaternary derivative of noroxymorphone in an sufficient amount. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to a sliding contact guide for a power transmission utilizing an endless, circulating, flexible power transmission medium. It relates, for example, to a guide in a chain drive transmission, in which a chain transmits power from a driving sprocket to a driven sprocket, or to a guide in a belt drive transmission, in which a belt transmits power from a driving pulley to a driven pulley.
BACKGROUND OF THE INVENTION
[0002] In general, as shown in FIG. 9, a chain or belt transmission device for valve timing in an internal combustion engine, or for transmitting rotational power in another drive mechanism, includes a chain or belt CH, which transmits power from a driving sprocket or pulley S 1 to one or more driven sprockets or pulleys S 2 . The transmission includes a pivotally mounted, movable sliding contact guide Ga, which cooperates with a tensioner, and a fixed sliding contact guide Gb. The movable guide and the fixed guide are attached to a frame E of the engine or other drive mechanism by suitable pins P or by bolts, or similar mountings. The guides make sliding contact with the chain or belt CH, and prevent vibration of the chain or belt both in the plane of its traveling path (which is usually vertical), and in the transverse direction. The pivoting guide Ga cooperates with a tensioner T to maintain tension in the chain or belt.
[0003] [0003]FIG. 7, is an exploded side view of a movable guide (i.e., a tensioner lever) 30 for use with a chain, as disclosed in Japanese Patent No. 3253951. FIG. 8 is bottom plan view of the guide. The guide 30 comprises a guide body including a shoe 31 on a surface of which chain CH travels in sliding contact. A plate-receiving portion 32 is provided on a back of the shoe 31 , and extends along the longitudinal direction of the guide. The plate-receiving portion and the shoe are integrally molded as a unit from a synthetic resin. A reinforcing plate 40 , composed of a rigid material, is fitted into a slot 32 a in an edge of the plate-receiving portion. This slot opens in a direction facing away from the shoe, and extends along the longitudinal direction of the guide. The plate-receiving portion 32 is provided with a mounting hole 32 b adjacent one end thereof, for mounting the guide body on a frame of an engine, or other machine. A mounting hole 41 is provided adjacent one end of the reinforcing plate 32 at a position such that it comes into register with the mounting hole 32 b when the reinforcing plate 40 is fitted into slot 32 a . This allows the guide body and reinforcing plate to be fastened together on a pivot means such as a mounting bolt, a mounting pin or the like.
[0004] Since the shoe 31 and the plate-receiving portion 32 are integrally molded as a unit from a synthetic resin, it is not necessary to provide a separate shoe. Thus, the number of parts, and the number of production steps are reduced. Further, since the reinforcing plate 40 is received in slot 32 a in the plate-receiving portion 32 the strength of the guide in its pivoting direction is increased, and its bending rigidity, toughness and strength are significantly improved. The use of this type of guide has increased rapidly due to the demand for low cost and high reliability.
[0005] However, in order to increase the strength of the guide, it is necessary to increase the thickness in the reinforcing plate. The increase in thickness results in an undesirable increase in the weight of the reinforcing plate and in the overall weight of the guide. Moreover, when reinforcing plates are formed by punching a rolled metallic sheet or by molding a fiber-reinforced resin, production difficulties are encountered when increased plate thickness is desired. Furthermore, some regions in the reinforcing plate require higher strength than others. For example the region surrounding the mounting hole, and the region adjacent the part that contacts the plunger of a tensioner, require higher strength than other regions. However, it was not easy to vary the strength of a conventional reinforcing plate to meet the requirements for added strength only in the regions where additional strength is needed. Accordingly, to meet these regional strength requirements, it was conventional practice to make the entire reinforcing plate thicker, and the result was an increase in the weight of the reinforcing plate and in the overall weight of the guide body.
[0006] Accordingly a general object of the invention is to solve one or more of the above-mentioned problems of conventional sliding contact guides. Another object of the invention is to provide a sliding contact guide having enhanced strength without increasing the weight guide. Still another object is to provide a simple way to control strength distribution in a guide, according to the strength requirements of respective regions of the guide body.
BRIEF SUMMARY OF THE INVENTION
[0007] The sliding contact guide in accordance with the invention comprises an elongated shoe composed of synthetic resin, an elongated plate-receiving portion, and a reinforcing plate. The shoe has front and back sides and a surface extending longitudinally on the front side for sliding contact with a flexible power transmission medium. The elongated plate-receiving portion, which is also composed of synthetic resin, is integrally molded as a unit with the shoe on the back side thereof. The plate-receiving portion extends longitudinally along the back side of the shoe and has a longitudinally extending slot. The slot has opposed walls disposed in perpendicular relation to the transmission medium-contacting surface. A body mounting hole extends through the plate-receiving portion adjacent one end of the guide and intersecting the slot. The reinforcing plate, for reinforcing the guide, fits in the slot and has opposite surfaces respectively in opposed relationship to the opposed walls of the slot, and a through hole in register with the body mounting hole. In accordance with the invention, at least one of the opposite surfaces of the reinforcing plate has a concavo-convex shape.
[0008] The concavo-convex shape can be formed by bends along lines extending parallel to the opposed walls of the slot and transverse to the direction of elongation of the shoe. Alternatively, the concavo-convex shape can be formed by at least one bend extending substantially parallel to the direction of elongation of the shoe. At regions requiring increased strength, the bend lines can be closer together than the bend lines in other regions.
[0009] The materials, which form a guide body in the invention, are not significantly limited. However, since the sliding contact surface of the guide body functions as a shoe, the materials of the guide body are preferably so-called engineering plastics such as polyamide resin and the like, having high durability and superior lubricating properties. Suitable materials include nylon 6, nylon 66, all aromatic nylons and the like. Furthermore, fiber reinforced plastics may be used alone, or in combination with other materials, depending on requirements such as bending strength and the like.
[0010] Provided that the materials of the reinforcing plates have sufficient bending rigidity and strength, they are also not limited significantly. However, the materials of the reinforcing plates are preferably iron-based metals such as cast iron, stainless steel and the like, non-ferrous metals containing aluminum, magnesium, titanium or the like as the main component, engineering plastics such as polyamide resin, fiber-reinforced plastics, and the like.
[0011] By virtue of the concavo-convex shape of the reinforcing plate, the plate has an improved load-supporting capability over that of a conventional reinforcing plate composed of the same material. The sliding contact guide exhibits a significantly higher strength compared to that of a flat reinforcing plate having the same thickness.
[0012] When the concavo-convex shape is formed by bend lines parallel to the opposed walls of the slot and transverse to the direction of elongation of the shoe, the guide has improved strength to withstand loads exerted in the direction perpendicular to its shoe, for example impact loads exerted by the plunger of a tensioner cooperating with the guide.
[0013] On the other hand, when the concavo-convex shape is formed by one or more bend line extending in the longitudinal direction of the reinforcing plate, higher strength is exerted in longitudinal directional, so that the guide is better able to withstand longitudinal loads, such as vibration due to the pivoting of the guide or the like.
[0014] The density of the concavo-convex portions of the reinforcing plate can be varied by selecting the spacing of the bend lines, and accordingly the strength of the plate can be selectively enhanced in regions where larger loads are applied, such as the portion engaged by a plunger of the tensioner, or the portion surrounding the mounting hole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is an exploded perspective view showing a movable guide according to a first embodiment of the invention;
[0016] [0016]FIG. 2 is a bottom plan view of the movable guide show 7 n in FIG. 1;
[0017] [0017]FIG. 3 is an exploded cross-sectional view taken on plane A-A in FIG., also showing a mounting pin;
[0018] FIGS. 4 ( a ), 4 ( b ) and 4 ( c ) are bottom plan views, corresponding to FIG. 2, of guides in accordance with further embodiments of the invention, showing alternative shapes for the reinforcing plate;
[0019] [0019]FIG. 5 is an exploded perspective view showing a movaOble guide according to still another embodiment of the invention;
[0020] [0020]FIG. 6 is a cross-sectional view taken on plane A-A in FIG. 5;
[0021] [0021]FIG. 7 is an exploded side view of a conventional movable guide
[0022] [0022]FIG. 8 is a bottom plan view of the conventional movable guide shown in FIG. 7; and
[0023] [0023]FIG. 9 is an elevational view showing sliding contact guides in the valve timing transmission of an internal combustion engine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] In FIG. 1, a plastic movable guide 10 is formed by incorporating a reinforcing plate 20 into a guide body in the direction of the arrow.
[0025] This guide body is a plastic body integrally molded as a unit from synthetic resin, and comprises a shoe 11 having a surface on one side for sliding contact with a traveling chain, and a plate-receiving portion 12 provided on the back side of the shoe 11 and extending along the longitudinal direction of the guide. The guide body includes a flange 12 f formed at an edge of the plate-receiving portion 12 remote from the shoe 11 , and a boss 12 c having a mounting hole 12 b for pivotally mounting the guide body on the frame of an engine, or other machine incorporating a flexible transmission medium. The plate-receiving portion 12 has truss-shaped reinforcing ribs 12 e , and a slot 12 a opening at flange 12 f , facing away from the shoe, and extending along the longitudinal direction of the guide.
[0026] To reinforce the guide body, a reinforcing plate 20 , having a mounting hole 21 , is fitted into the slot 12 a . Holes 22 are locking holes for engagement with locking pieces 12 g of the guide body when the reinforcing plate 20 is inserted into the guide body, in order to secure the reinforcing plate 20 to the guide body.
[0027] A plunger-receiving portion 12 d is provided adjacent the pivoting front-end portion of the guide body for engagement with the plunger of a tensioner. The shape of the plunger-receiving portion 12 d is not limited especially. For example, to prevent the plunger from becoming dislodged from the plunger-receiving portion 12 d by transverse vibration, a protruding portion (not shown) is preferably formed at the edge of the flange 12 a , for preventing transverse shift of the plunger.
[0028] With the reinforcing plate 20 fitted into it, the movable guide is attached to the frame of an engine, or other machine, by a mounting pin or mounting bolt such as the shoulder bolt 13 shown in FIG. 3. The mounting bolt has a pivot portion 13 A which is received in the holes 12 b and 21 of the guide body and reinforcing plate, respectively. The mounting bolt not only establishes a pivot, but also assists holes 22 and locking pieces 12 g in fastening the guide body 10 and the reinforcing plate 20 together.
[0029] The reinforcing plate 20 is molded in a bent shape by pressing a metallic rolled sheet using a wave-shaped mold such that the bending lines of the plate are parallel to the walls of slot 12 a , but transverse to the shoe, as shown in FIG. 1. The thickness of the material from which the reinforcing plate is formed is approximately one-half the width in the slot 12 a . However, by virtue of the concavo-convex configuration of the reinforcing plate, it can fill the slot 12 a as can be seen in FIG. 2. The reinforcing plate, bent as shown in FIGS. 1 and 2, can withstand large loads directed in the pivoting direction of the guide, and the guide exhibits a strength that is the same as or greater than that of a flat reinforcing plate having a thickness the same as the slot width.
[0030] Although the reinforcing plate 20 was molded into a bent shape by pressing a rolled metallic sheet, the concavo-convex shape on the surface of the reinforcing plate can be also obtained by a die casting process, using a die casting mold having a concavo-convex shape. A fiber-reinforced resin can also be formed into the concavo-convex shape
[0031] The concavo-convex shapes of the surface of the reinforcing plate are not limited to the shape shown in FIG. 2. Alternatively, a wave type shape such as shown in FIG. 4( a ) can be adopted. Likewise, a bent shape, as shown in FIG. 4( b ), having no longitudinally extending flat portions can be used. As a further alternative, a shape in which ribs 20 a are formed on both surfaces of a reinforcing plate, as shown in FIG. 4( c ), may be used. In the embodiments shown in FIGS. 2 and 4( a ) to 4 ( c ), a regular concavo-convex shape is formed, in which the bends are disposed at equal intervals. However, a more dense configuration of bend lines can be used to enhance the strength of the reinforcing plate. Thus, the concavo-convex shape in portions positioned at regions where a large load is applied, such as a region near the tensioner receiving portion 12 d , and/or a region near the boss 12 c , can be formed with a bend line density greater than that in other regions of the reinforcing plate formed than in other regions so that the strength of the guide can be selectively improved.
[0032] The embodiment shown in FIGS. 5 and 6, is substantially the same as the embodiments of FIGS. 1 - 4 ( c ) except that the reinforcing plate 20 is formed so that the bending lines extend along the longitudinal direction of the reinforcing plate, and enhances the strength on the load in the longitudinal direction of the guide.
[0033] In the embodiments described so far, each of the guides is a movable guide, supported for pivotal movement on a mounting pin, bolt or the like. However, the invention can be applied to a fixed guide attached to a frame of an engine or the like by two mounting pins or bolts.
[0034] The most important advantages of the invention may be summarized as follows.
[0035] First, the concavo-convex shape of the reinforcing plate, provides the plate with an improved load-supporting capability. The sliding contact guide exhibits a significantly higher strength compared to that of a flat reinforcing plate having the same thickness. As a result the weight of the guide can be decreased, which contributes to improved fuel economy in the case of an engine.
[0036] When the concavo-convex shape is formed by bend lines parallel to the opposed walls of the slot and transverse to the direction of elongation of the shoe, the guide has improved strength to withstand loads exerted in the direction perpendicular to its shoe, for example impact loads exerted by the plunger of a tensioner cooperating with the guide.
[0037] On the other hand, when the concavo-convex shape is formed by one or more bend line extending in the longitudinal direction of the reinforcing plate, higher strength is exerted in longitudinal directional, so that the guide is better able to withstand longitudinal loads, such as vibration due to the pivoting of the guide or the like.
[0038] The density of the concavo-convex portions of the reinforcing plate can be varied by selecting the spacing of the bend lines, and accordingly the strength of the plate can be selectively enhanced in regions where larger loads are applied, such as the portion engaged by a plunger of the tensioner, and/or the portion surrounding the mounting hole. Thus, the bend lines can be formed close together at and near the ends of the reinforcing plate, and farther apart in the central portion of the plate.
[0039] The sliding contact guide according to the invention can be produced simply by changing the molds, dies or the like used to reproduce the reinforcing plate. Thus, production cost is not increased. Moreover the material cost is reduced. Therefore, the invention has significant industrial value. | In a sliding contact guide for a flexible power transmission medium such as a chain or belt, the guide body includes a shoe and a plate-receiving portion integrally molded as a unit from a synthetic resin. A reinforcing plate is inserted into a slot in the plate-receiving portion. A surface of the reinforcing plate is of a concavo-convex shape. The concavo-convex shape enhances the strength of the reinforcing plate without increasing the overall weight of the guide. By controlling the spacing of the bend lines forming the concavo-convex configuration, the strength of the guide can be controlled in accordance with strength requirements for different regions of the guide. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent application Ser. No. 60/657,536 entitled “DISCOVERABILITY AND ENUMERATION MECHANISMS IN A HIERARCHICALLY SECURE STORAGE SYSTEM” and filed Feb. 28, 2005. The entirety of the above-noted application is incorporated by reference herein.
BACKGROUND
[0002] Storage systems traditionally use a containment hierarchy to organize units of storage. In accordance with these systems, a container and therefore, inherently the units of data maintained within the container, are independently securable to facilitate the provisioning of access to the principals. Conventional systems offer discoverability through traversal that could limit access to data upon encountering a container that is not accessible to the principal.
[0003] These systems suffer from at least the following limitations. One limitation is that a principal cannot visualize the global set of data for which they have access. In other words, upon rendering a global set of data, if a container is encountered whereby a user does not have access, the contents (e.g., units of data) of this container could not be rendered. Consider a situation where a sub-folder or sub-container exists within a container with access restrictions placed upon the principal. In this scenario, the principal could not visualize (e.g., discover) or access the contents of the sub-folder even if adequate permissions are in place. This restrictive discoverablity is due to lack of adequate permissions to access the parent folder.
[0004] Another limitation of traditional systems is that a principal cannot operate on all the data at once. For example, a restriction for an operation such as “grant access to FABRIKAM\alice for all data in the tree-like structure rooted at a given node” would not be possible as restrictions may be in place that would limit access to some of the data in the tree-like structure. In some traditional systems, such operation is effected in the user context and rather than a system context.
[0005] Yet another limitation of some conventional systems is that accessing data requires adequate permissions in place for all of the containers from the point of connection to the immediate parent of the unit of data in addition to access permissions on the unit of storage. In other words, in some systems, even if the direct file path of the data is known, permission to access the data may be restricted if access permissions do not exist from the point of connection to the immediate parent where the data is stored.
[0006] Still another limitation is that, for effective enumeration on the existing file system model, traditional storage systems distinguish between data and metadata. For rich end-user types, this separation creates difficulty to recognize the distinction between metadata and data.
SUMMARY
[0007] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
[0008] The invention disclosed and claimed herein, in one aspect thereof, comprises a system that generates a per user abstraction of a store from a connection point. This abstraction can facilitate discoverability of data maintained in a hierarchically secure storage system in accordance with applicable permissions. Filtering a view set from of a hierarchically secured containment structure based on the access permissions of the principal is one of the novel features of the invention. The invention can offer a collection of primitives that can operate on this aggregation that span multiple container hierarchies with potentially heterogeneous security policies (e.g., security descriptors). The model can reduce the necessity to traverse the container hierarchy to discover all the read-accessible items in a domain.
[0009] In yet another aspect, an artificial intelligence (AI) component is provided that employs a probabilistic and/or statistical-based analysis to prognose or infer an action that a user desires to be automatically performed.
[0010] To the accomplishment of the foregoing and related ends, certain illustrative aspects of the invention are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention can be employed and the subject invention is intended to include all such aspects and their equivalents. Other advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a general component block diagram of a system that facilitates discoverability of data in a hierarchical secure storage system in accordance with an aspect of the invention.
[0012] FIG. 2 illustrates a block diagram of a system that includes a single instance table and a security descriptor table in accordance with an aspect of the invention.
[0013] FIG. 3 illustrates a system that classifies items in a type system as instances of generic container types and compound item types in accordance with an aspect.
[0014] FIG. 4 illustrates a block diagram of a system having a store component and a client component on opposite sides of a trust boundary in accordance with an aspect of the invention.
[0015] FIG. 5 illustrates a methodology of initialization in accordance with an aspect of the invention.
[0016] FIG. 6 is a relational diagram illustrating that operations which query the views can operate in the user context where access control for selection statements can be enforced by row level security in accordance with an aspect of the invention.
[0017] FIG. 7 is a block diagram of a system that employs artificial intelligence-based mechanisms in accordance with an aspect of the invention.
[0018] FIG. 8 illustrates a block diagram of a computer operable to execute the disclosed architecture.
[0019] FIG. 9 illustrates a schematic block diagram of an exemplary computing environment in accordance with the subject invention.
DETAILED DESCRIPTION
[0020] The invention is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the subject invention. It may be evident, however, that the invention can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the invention.
[0021] As used in this application, the terms “component” and “system” are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed between two or more computers.
[0022] As used herein, the term to “infer” or “inference” refer generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic—that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. Such inference results in the construction of new events or actions from a set of observed events and/or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or several event and data sources.
[0023] Aspects of this invention are related to computer systems and more particularly to the discoverability of data maintained in a hierarchically secure storage system(s). As described supra, traditional storage systems have limitations with regard to security-related discoverability mechanisms. To this end, emerging database-oriented file systems can support rich querying and provide schematized end user types for common data units (e.g., contacts). These schematized end-user types facilitate and can enhance the interoperability of applications with respect to data.
[0024] The subject invention takes into account a hierarchical representation of data. More particularly, this invention takes into account that data can be “bucketized” into different folders and thereafter placed into different containers. Users can employ these containers to organize their data. For example, data can be organized (e.g., bucketized) into categories such as pictures, music, documents, etc. Additionally, these categories can be further organized into containers thereby establishing a hierarchical representation of the data. By way of example, within pictures, there could be pictures of “my family”, “my vacation”, “my wedding”, etc. As well, sub-categories can exist in accordance with the hierarchy.
[0025] In accordance with this hierarchical representation, the invention can facilitate associating a security policy (e.g., security descriptor) with each object. It will be appreciated that an object can be any data element contained within a container as well as the container itself. As well, each object can be represented in an individual row of a table. This row-based representation will be better understood upon a discussion of the figures that follow.
[0026] In an aspect, the security descriptor can enable the provisioning of these objects for data access. By way of example, in accordance with an aspect of the invention, a security policy can facilitate setting a “my vacations” folder to permit access by anyone in a group, “my family.” As well, within “my vacations” a user can further limit access to certain members of “my family” to access a subfolder (e.g., “my trip to Seattle”).
[0027] In accordance with conventional systems, accessible exploration of a data store ends at any point when a folder is reached for which the user does not have enumeration access. Consider a hierarchy where F1 contains F2 which contains F3—the moment that the user reaches F2 where no permission is granted, the user will not have the ability to view data within F3. Even though the user may have access to F3, conventional systems will prohibit discoverability because F3 is contained within F2 for which permissions are not in place—this is a limitation. The subject invention enables a user to have uniform access to explore (e.g., discover) and/or render thereby allowing employment of all data in a data store whereby permissions are granted and in place. As described supra, this uniform access can be facilitated via a security policy associated with each object in a data store. As will be understood, each security policy can be associated to a row-level item.
[0028] Traditional file systems employ two access modes to retrieve files. First, these systems facilitate a limited discovery method whereby a user can discover data elements for which adequate security permissions exist. The other is a direct access mechanism whereby a user can access a file if the full path is known and permission to access is in place.
[0029] In addition to the two disparate modes, the subject invention can employ a third mode which is a query mode (e.g., data store filtering) that allows access and discovery based upon security credentials. Unlike traditional systems, the subject invention can provide a mechanism to query all data based upon a defined specified property as well as to operate on that data. With this invention, so long as access credentials are in place, the data can be discovered and operated on as desired.
[0030] In accordance therewith, the subject invention can enable a security policy (e.g., security descriptor) that can be set in the root of a tree-like structure (e.g., hierarchical data organization) and propagated through the tree-like structure to all of the children in the structure. It is to be understood that the propagated security descriptor can be based upon the parent security policy, child security policy, and/or the type of the object. Logic can be employed that effects generating and propagating a security policy throughout a tree-like structure. As will be described infra, rules-based logic and/or artificial intelligence can be employed to propagate a security policy.
[0031] Consider a scenario where a user creates a new item. In this scenario, there would be certain security policies (e.g., descriptors) of the parent that can be inherited or combined into the child. In one aspect, a user can have a folder (e.g., container) with permissions and when an object is created, the permissions for the object can be assumed to be the same. Alternatively, the permissions propagated to the newly created object can be intelligently determined based on both the permissions for the folder as well as permissions for the object. The preceding are examples of inheritance in accordance with aspects of the novel innovation.
[0032] It will be appreciated that, in traditional file systems, this propagation is not possible. Rather, to change permissions in accordance with conventional systems, an administrator must walk through each child of a tree-like structure and change the permissions as applicable. To the contrary, in accordance with aspects of this invention, when a root permission is changed (or established), the permission can automatically be propagated to all of the tree-like structure, including children.
[0033] It is important to note that, in some traditional systems, security permissions could only be propagated in the “user's context” at the time of the update. Although there are situations where permissions can change at a later time, conventional systems cannot automatically update these permissions.
[0034] The subject invention can propagate permissions in the “system's context.” Therefore, even if a user does not have permission to an intervening folder, if permissions are in place for a sub, sub-sub, etc. tree-like structure, these permissions can be propagated in accordance with the invention. This aspect will be better understood by considering the aforementioned F1, F2 and F3 example.
[0035] Continuing with the example, even if permissions are not in place for F2, if permissions exist for F3, permissions can be propagated from F1 to F3. Unlike earlier file systems that distinguish between attributes (e.g., name of the file, size, date created) and data (e.g., content of the file), in rich data systems it is difficult to determine between an attribute and data. As such, “items” were created and are used to grant access permissions on a per “item” basis regardless of the data element being an attribute or data. Accordingly, with respect to the subject invention, management of the security model can particularly be simplified since the system does not have to keep track of two separate security permissions. Rather, in one aspect, only one “read” or only one “write” permission is employed per item rather than employing two “read” permissions and two “write” permissions per item.
[0036] As a result, the invention can facilitate a user to view an abstraction of all of the data for which permissions are in place. These views can be defined over the entire store and subsequently rendered to a user. The view can be defined as an intersection of the items visible from a connection point and the set of security permissions allowed. As a result, a user can view and/or access items below a connection point for which the user has security permissions to view and/or access.
[0037] Referring initially to FIG. 1 , a system 100 that facilitates rendering a representation of content of file store is shown. Generally, system 100 can include a query component 102 and a row-level security component 104 . In operation, the query component 102 , together with the row-level security component 104 can identify items within a data component 106 that satisfy a security policy or permission. Once identified, the resultant set of data can be rendered to a user and/or application. For example, as previously described, the invention can render the resultant set via a display to a user.
[0038] With reference now to FIG. 2 , a more detailed block diagram of the row-level security component 104 is shown. In particular, the row-level security component 104 can include a security descriptor table 202 and a single instance table 204 . Each of these tables will be described in greater detail infra.
[0039] The security component 104 can provide a realization of row level security. When the user connects to a share (e.g., data component 106 ), implicit view definitions for each of the data types can be defined within the scope the connection. In order to add context to the invention, below is an exemplary view definition for a “Contact” type.
CREATE VIEW [System.Storage.Contacts.Store].[Contact] AS SELECT ItemId, TypeId, NamespaceName, ContainerId, ItemSyncMetadata, TREAT(Item AS [System.Storage.Contacts.Store].[Contact]) AS Item, PathHandle, EntityState, ObjectSize, ChangeInformation, PromotionStatus FROM [System.Storage.Store].[Table!Item] WHERE Item IS OF ([System.Storage.Contacts.Store].[Contact]) AND (@@ITEM_DOMAIN_IS_ROOT = 1 OR (PathHandle >= @@ITEM_DOMAIN AND PathHandle < @@ITEM_DOMAIN_LIMIT))
[0040] Each item is stored as a row in the entity tables ( 202 , 204 ). The above exemplary expression can effect filtering out the Contact types from the global scope of items in the store. Implicit to this filtering is the dimension of access control where a user would see only those items that are readable according to the security descriptors in the corresponding row.
[0041] In this example, a view definition can include the above-identified “WHERE” clause that restricts a view to items that are Contacts. The remainder of the example can restrict access to items from the connection point. It is to be understood that the view definition above does not include the security definition.
[0042] As described above, the security mechanism is a function of the row level security stored in tables ( 202 , 204 ). This mechanism is applied at the underlying table level of the view and has propagating effects on the view. When security is enabled on a per row basis, the rows for which a user does not have read access do not appear in the resultant set provided by the query component 102 .
[0043] In a file system model, each “item” is in a row, and each row has security associated with it. The row level security mechanism 104 restricts the rows from appearing in the results for those rows that a user does not have read access. The view, given a definition conveyed to the query component 102 , (as in the above example) can restrict the rendering (e.g., viewing) based at least in part upon the connection point. Therefore, the resultant set, can be the intersection of these two restrictions. It will be appreciated that these security mechanisms can occur implicit to the query definition. As a result, the user can be shielded from any of the operations.
[0044] The subject invention employs a single instancing mechanism that checks the security descriptor of each row in the table (e.g., 204 ). This single instancing mechanism makes it possible to appear that the system is performing a check across each row. A single instancing of security descriptors across rows can make the check of this mechanism efficient. It will be appreciated that security policies (e.g., access control lists) can be employed in place of the exemplary security descriptors. Therefore, it is to be understood that these additional novel aspects are intended to fall within the scope of this invention and claims appended hereto. Additionally, although ACLs are mentioned above, it is to be understood that other aspects exist that employ disparate security policies. These disparate security policies are intended to fall within the scope of this disclosure and claims appended hereto.
[0045] In operation, two tables ( 202 , 204 ) are maintained—a table of security descriptors 202 and a single instance table of mapping between the hash (e.g., SHA-1) of the security descriptor and a security descriptor identification (SDID). It will be appreciated that this SDID is a unique value. In accordance with the invention, single instancing refers to a mechanism where, for each unique security descriptor in the store, the system maintains a map between the SDID and a hash of the security descriptor.
[0046] Therefore, for each row, instead of storing a security descriptor, the SDID that corresponds to it is stored. In one aspect, when a user creates an item, the user has a choice to provide a security descriptor or leave it empty. If left empty, the security descriptor can be inherited from the parent from the item being created. When the user opts to explicitly provide a security descriptor, the system can merge the explicitly defined descriptor with the security descriptor of the parent to create one.
[0047] Once a determination is made what the security descriptor on the new item will be, a determination will be made if it already exists. If it does exist, the existing one will be used. If it does not exist, the new one will be saved.
[0048] To determine if a security descriptor exists, the invention references the single instance table 204 that includes a mapping of the security descriptor to a hash (e.g., SHA-1 hash) of the security descriptor. Therefore, in order to determine if there exists another item with the same security descriptor, a hash is computed of the subject security descriptor. The system then queries the single instancing table 204 for a row to see if any rows contain the same hash (e.g., SHA-1) of security descriptor. If a match is found, there is a high probability that it exists.
[0049] Next, a comparison the actual security descriptor is made to verify if the security descriptor exists. If the actual security descriptor is not the same, the system stores the security descriptor independently. It is to be appreciated that the system only relies upon the hash algorithm (e.g., SHA-1) to guarantee non-uniqueness. In other words, if the hashed value does not match a hashed value in the single instance table 204 , a determination can be made that the security descriptor does not exist.
[0050] There are three properties to a security descriptor—the hash (mathematically computed value based upon the binary of the security descriptor), the security descriptor itself (binary), and the SDID (integer value that points to the security descriptor). For each row, the system stores the ID of that particular row for which the security descriptor is relevant. Next, in the single instance table 204 , the system maps between the hash (e.g., SHA-1) and the SDID. In the security descriptor table 202 , the system maps between SDID and binary.
[0051] Therefore, the single instance table 204 and the security descriptor table 202 together give a complete mapping from a SHA-1 hash to SDID to binary. Effectively, these two tables ( 202 , 204 ) can be used to perform a single instancing check.
[0052] A security descriptor can have the following logical form:
[0053] O:owner_sid
[0054] G:group_sid
[0055] D:dacl_flags(ace1)(ace2) . . . (acen)
[0056] S:sacl_flags(ace1)(ace2) . . . (acen)
[0057] In the above example, O: identifies the owner, G: identifies the group, D: identifies the Discretionary Access Control List (DACL) (the section of the security descriptor in the scope of the disclosure) and S: identifies the System Access Control List (SACL). DACL is a collection of Access Control Entries (ACE)—each can take the following form.
[0000] ace_type; ace_flags; rights; account_sid
[0058] A given principal can be granted or denied access to specific items. Accordingly, the denied items can be implicitly filtered out from the user views. A filtering engine or query component 102 can scan all the items in the store agnostic to any container semantics and produce a uniform set thereby circumventing the limitations of the traversals in the traditional file systems.
[0059] The two internal tables ( 202 , 204 ) can be used to facilitate the storage and access control in the system. In an exemplary aspect, the system can employ a [System.Storage.Store][TableSecurityDescriptorSingleInstance] table 204 (e.g., instance table) and a Sys.security_descriptors table 202 (e.g., security descriptor table). The Sys.security_descriptors table 202 is a catalog view of security descriptors. These descriptors can be created or deleted using data definition language (DDL) primitives provided by SQL Server. The single instance table 204 can key to a central processing unit (CPU) and memory optimizations in the system.
[0060] In accordance with an aspect, it can be common that a significant number of items share the same security policy or descriptor. In one example, the maximum size of an access control list (ACL) is 64 KB thus a given security descriptor can be in the order of 128 KB. It will be appreciated that it can be inefficient to store a value of this size with each item given its potentially high degree of commonality. Therefore, each unique security descriptor can be stored in the Sys.security_descriptors table 202 and a mapping between the descriptor and its SHA-1 hash can be maintained in the single instance table 204 . As stated previously, a SHA-1 has does not guarantee uniqueness of outputs, but a collision is extremely improbable given its large output range (e.g., 2ˆ160). Since the instance table 204 can have a self-healing nature, it can guarantee that the system can auto recover from corruption or inconsistencies.
[0061] Item/Extension/Fragment/Link tables have an entry for the SDID that can be marked with SECURITY attribute. This can ensure that all read access to these tables and any views built on top of these views are subject to an access check requesting (FILE_READ_DATA|FILE_READ_ATTRIBUTES). Rows in the ItemExtension, Link and ItemFragment tables have the same security descriptor as the corresponding row in the Item table.
[0062] The mechanism described supra can be considered to be at the core of an authorization model in the read path for emerging file systems. Any authorization model can inherently rely on an authentication model. In one example, when a user connects to the store, the user can be authenticated (e.g., deemed trustworthy) using the preferred operating system authentication mechanisms (e.g., NTLM (NT LAN Manager), Kerberos). The net result of authentication can be a security token representing the user that is accessing the file system. This token can be used subsequently for making authorization decisions for the principal.
[0063] In accordance with another aspect of the invention, items secured using row or record level security (RLS) can be protected from the storage service account as well. For security evaluation, the service account can be considered like any other NT-brand account. While this can particularly guarantee uniform security semantics, it brings out interesting problems in the update path. For example, consider a user trying to create an item with a given Namespace name. Namespace names in emerging file systems are guaranteed to be unique in their containing folder, providing an unambiguous naming system. During create operations, the system guarantees this uniqueness by ensuring the non-existence of other items in the same folder with the same namespace name.
[0064] In this scenario, an item may already exist in the folder with access permissions denied to the service account. This invention can address this problem by using a signature mechanism. Update primitives that require global access to the store can be signed with certificates that are granted “exempt RLS” privilege. From within the context of such a primitive, the system can query the store and row level security will be bypassed in this case.
[0065] As described supra, traditional file systems have made a distinction between attributes and data for enabling the traversal semantics. The lack of discoverability and query-based semantics induced a model where attributes and data are distinguished for access control decisions. The subject invention provides seamless access to data and attributes by facilitating all or nothing semantics on the type system.
[0066] Following is a detailed discussion of an exemplary file system security model. The discussion that follows describes component functionality in a number of disparate scenarios. It is to be appreciated that these described scenarios are provided merely to provide context to the invention and are not intended to limit the invention, or claims appended hereto, in any way.
[0067] Referring first to the file system security model, in one aspect, data can be organized in a store as an “item” which can refer to the smallest unit of consistency in file system. An “item” can be independently secured, serialized, synchronized, copied, backed-up/restored, etc. It will be appreciated that a file system item can be described as an instance of a type whose ancestor is the type System.Storage.Item, which is an entity type. All items in file system can be stored in a single global extent of items. As well, each item can have a unique identifier which is guaranteed to be unique for all items in a given file system store.
[0068] Referring now to FIG. 3 , a system 300 is shown. System 300 is in accordance with the context of this security discussion whereas items in a type system 302 can be classified as instances of generic container types 304 and compound item types 306 . Generic containers 304 can be used to model folders and any other hierarchical data collection buckets. Compound item types 306 can be used to model a single logical unit of data for an application. Instances of this type can give all or nothing semantics for typical data operations like copy, move, sync etc. Examples of the latter include, but are not limited to, mail messages, pictures, contacts, etc. Instances (denoted by dashed lines) of compound item types 306 can be further classified as file backed items 308 (FBIs) and non-file backed items 310 (nFBIs). It will be appreciated that a Win32-brand access is semantically limited to FBIs and generic containers.
[0069] The following containment hierarchy (e.g., tree-like structure) applies to the items. Generic containers 304 and compound items 306 can contain any other item types including generic containers. Items within these additional generic containers can also be independently secured. FBIs 308 can not contain other items and hence form leaf nodes in the hierarchy.
[0070] Referring now to FIG. 4 , it will be appreciated that a file system 400 can include two major components on opposite sides of a trust boundary 402 —a store component 404 and a client component 406 . As illustrated, store component 404 can include 1 to N object components, where N is an integer. Object components 1 to N can be referred to individually or collectively as object components 408 . The store component 404 that deals with storage and retrieval of the object 408 can form a trusted file system subsystem between the store component 404 and the client component 406 .
[0071] The client component 406 which can provide programming semantics to the platform usually runs in the user processes. It will be understood that the users can be authenticated at connection time. Retrieved objects 408 (e.g., items) can be materialized in the client space. In one aspect, no security checks or access constraints are enforced by the client on these objects 408 . In accordance with the invention, the store component 404 can enforce access control (via access control component 410 ) when the programming context is persisted to the store component 404 . Following is a discussion of user authentication.
[0072] File system 400 can expose the notion of a security principal that can perform actions against the items 408 contained in a file system store 404 . In aspects of the invention, a security principal could be a user or a security group. Accordingly, the security principal can be represented by a security identifier (SID).
[0073] As illustrated in FIG. 4 , a connection to the file system service is in the context of a security principal that is successfully authenticated by the access control component 410 . It will be understood that file system authentication (e.g., via access control component 410 ) can be a derivative of the operating system authentication mechanism. For example, a file system authentication can be a derivative of a Windows-brand authentication available in the SQL (structured query language) security model. For example, it will be appreciated that SQL offers another built-in authentication mechanism called SQL authentication which may not be supported in file system 400 .
[0074] Continuing with the example, an attempted connection by a Windows-brand user can be authenticated by the file system 400 while leveraging Windows-brand provided authentication services such as Kerberos, NTLM, etc. In the example, an authenticated user is mapped to a “public” role in SQL which is used for authorization decisions in the store 404 . In one aspect, a built-in administrator (BA) will be mapped to SQL administrators granting SQL administrative privileges to the BA. In an alternative aspect, file system administration can be solely built using file system primitives. As such, BA would not be a member of the SQL administrators in the alternative aspect.
[0075] The net result of the authentication is a security token that represents the principal that accesses the file system 400 . This data structure can include the SID of the incoming principal as well as the SID's of all the groups for which the principal is a member. In addition, all privileges held by the user can be, by default, enabled while connecting to file system 400 . As will be better understood following the discussion below, this token can be subsequently used to make authorization decisions.
[0076] Turning now to a discussion of authorization, as described supra, file system authorization can be built on share level security and item level security. As used in this description, a “share” can refer to an alias to an item 408 in the store 410 . When a store 410 is created, a default share is created aliased to the root item. Users with sufficient privilege can create shares aliased to any generic container (e.g., item 408 ) in the store 410 .
[0077] The file system can use universal naming convention paths to expose namespace locally and remotely. Hence file system clients connect to a share whereby the connection point together with the relative hierarchy of names constitutes the addressing mechanism to file system objects 408 .
[0078] By way of example, suppose a user connects to a root share to access foo. Accordingly, the access would appear as \\MachineName\StoreName\RootShare\ . . . \foo. Similarly, the user connected to a share called AliceShare would access the same object as \\MachineName\AliceShare\ . . . \foo. In this example, the effective permission on the item can be a function of the security descriptor on the connected share and the item. It is to be understood that the former defines a share level security and the latter defines an item level security. Details on each of these security mechanisms as well as rules for composing the effective security descriptors are described infra.
[0079] Beginning with a discussion of the share level security, file system shares in accordance with the invention are somewhat akin to Windows-brand shares. In order to provide uniform semantics over local and remote access, for every file system share created, a mirroring share can be created as well. Shares can be stored as items in a catalog store and can be securable using item security which is the topic that follows. Permissions on these items and on the shares can be the same granting uniform access semantics on both local and remote access.
[0080] Default permissions can be granted as desired with respect to items. For example, disparate items in a share can have different default permissions applied with respect to user characteristics (e.g., local system built-in administrator, authenticated, interactive . . . ).
[0081] Similar to Windows-brand shares, the default values for the share security descriptor are configurable using the registry setting at LanManServer\DefaultSecurity\SrvsvcDefaultShareInfo.
[0082] Item security mechanisms can employ security descriptors to effect access control. Accordingly, in one aspect, a security descriptor can be communicated by APIs (application program interfaces) in a security descriptor definition language string format and stored in the database in a packed binary format under the VARBINARY column of Sys.Security_Descriptors, the security descriptor table ( 202 of FIG. 2 ).
[0083] A new security descriptor table, 202 of FIG. 2 as described supra, Sys.Security_Descriptors, exists to hold each unique Security Descriptor, stored as a packed binary security descriptor with a unique ID (SDID) for use as a foreign key in file system base tables. For example, a security descriptor table can appear as follows:
SDID SecurityDescriptor VARBINARY 55 XXXXXXXXXX 56 XXXXXXXXXX
[0084] Although the security descriptor table above employs a binary representation for the security descriptor, it is to be appreciated that any suitable representation can be employed without departing from the spirit and scope of the invention and claims appended hereto.
[0085] Referring now to a discussion of representation and storage of security descriptors and related data, as described supra, the invention employs two internal tables that can hold security descriptor related information—a security descriptor table (e.g., sys.security_descriptors and a single instance table (e.g., [System.Storage.Store] [TableSecurityDescriptorSingleInstance]).
[0086] Continuing with the example, Sys.security_descriptors is a catalog view maintained by SQL. This binary is stored in a corresponding row with the SDID.
[0087] The single instance table can be maintained by the file system. It contains a map of a hash of the binary security descriptor to the SDID identified in the aforementioned Sys.security_descriptors view or table. In one example, a SHA-1 hash can be employed. In one aspect, if multiple items with the same security descriptors are created, a single entry can exist in both the tables.
[0088] As stated above, another novel feature of the invention is that if the single instance table is ever corrupted, it can be destroyed as it is a self-healing table. In other words, if a corruption were to occur, a new table can be created merely by generating new hash values and associating them to the appropriate SDID.
[0089] In an aspect, Item/Extension/Fragment/Link tables can have an entry for the SDID that is marked with “security” attribute. It will be understood that this can ensure that any read access to these tables and any views built on top of these views could be subject to an access check asking for (FILE_READ_DATA|FILE_READ_ATTRIBUTES). It will further be understood that the ItemExtension, Link and ItemFragment table must have the same security descriptor table as the Item table.
[0090] FIG. 5 illustrates a methodology of initialization in accordance with an aspect of the invention. While, for purposes of simplicity of explanation, the one or more methodologies shown herein, e.g., in the form of a flow chart, are shown and described as a series of acts, it is to be understood and appreciated that the subject invention is not limited by the order of acts, as some acts may, in accordance with the invention, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with the invention.
[0091] While building a model database during the build process security data structures are initialized. At 502 , tables are set up. In one example, setting up tables can include setting up Sys.server_principals, Sys.database_principals, Sys.server_role_members and Sys.database_role_members. At 504 , a single instance table is created. In accordance with our example, [System.Storage.Store] [TableSecurityDescriptorSingleInstance] can be created at 504 .
[0092] At 506 a root security descriptor is created. This root security descriptor corresponds to the root of the store (e.g., administrators have full control). At 508 , item level security descriptors are created. For example, at 508 , security descriptors for tombstone items can be created such that administrators have full control and authenticated users have read access. At 510 , these entries are added to the single instance table.
[0093] The file system can support inheritance of ACLs. For example, from the time of item creation (e.g., CreateItem or CreateComplexItems), the security descriptor for the item can be computed using the supplied security descriptor (if any), the parent security descriptor, the type of item and the token (e.g., NT-brand token) of the caller.
[0094] Referring now to a discussion of access checks, all update APIs perform appropriate access checks by calling [System.Storage.Store][HasSecurityAccess]. The API ensures that the caller is granted the request permission bit both at the share level as well as the security descriptor (e.g., item, record) level. In one specific aspect, the access check performed on the security descriptor (of the parent) is different (FILE_DELETE_CHILD) from the one (DELETE) performed on the share. For other cases, the two access checks can be consistent.
[0095] Continuing with the example, ACL propagation throughout the tree-like structure can be performed when SetItemSecurity (with a new DACL or SACL) or MoveItem with a new parent is called. After the appropriate access checks are performed to ensure that the caller is allowed to perform the operation, ACL propagation can be effected in the context of File system. No access checks are done on the subtree-like structure for which ACLs are updated.
[0096] It is to be appreciated that the invention can employ asynchronous and/or synchronous propagation. Following is a discussion of synchronous propagation. It is to be understood that the root of the subtree-like structure has nothing to do with Compound items. Rather, the root of the subtree-like structure is a generic term to describe the node on which SetItemSecurity or MoveItem is called.
[0097] In accordance with synchronous propagation, the new security descriptor for the root item is computed. If DACL or SACL are not updated, the SDID if updated for the item, extension, fragment and link tables and the system returns. The entire item subtree-like structure is locked starting at the item. In the example, it is not necessary to lock any other table (Extension, Fragment, Link).
[0098] Next, a temporary table that contains all the items in the act above can be created. The temporary table can have the following characteristics. The temporary table can have ContainerId, ItemId, and NewSdId. As well, initially, NewSdId can be NULL for all but the root of the subtree-like structure.
[0099] For each entry in the temporary table, the new SD can be computed using the new parent SD, the type of the item and the existing item SD. In the example, CreatePrivateObjectSecurityEx(SEF_AVOID_PRIVILEGE_CHECK|SEF_AVOID_OWNER_CHECK) can be used. Accordingly, the temporary table can be traversed level by level each time processing those rows whose new parent SD has been computed and the new SDID for the item is NULL. In accordance with the example, this walks the table one level at a time.
[0100] The number of iterations is O (e.g., depth of the tree-like structure). Two issues can be considered. First, computation of new security descriptors can be considered. Second, update of security descriptors on all children can be considered. In the second scenario, the theoretical limit is O (e.g., number of children). In the first scenario, although not necessary, it is usually O (depth of the tree). If needed, a new Security Descriptor can be created (e.g., in the single instance and Sys.security_descriptors tables). Next, the temporary SDID table is updated in the temporary table. Finally, Item, Extension, Link and Fragment table can be updated using the data computed in temporary table.
[0101] FIG. 6 illustrates that T/SQL Operations which query the Master Table Views operate in the User Context where Access Control for SELECT statements is enforced by Row Level Security. Additionally, calls to the File system Store Update API are made in the User Context but executed in the System Context. The implementation can therefore enforce permission checks for the caller.
[0102] FIG. 7 illustrates a system 700 that employs artificial intelligence (AI) which facilitates automating one or more features in accordance with the subject invention. The subject invention (e.g., in connection with implementing security policies) can employ various AI-based schemes for carrying out various aspects thereof. For example, a process for determining if a security descriptor should be set and, if so, the level of security to employ can be facilitated via an automatic classifier system and process. Moreover, where the single instance and security descriptor tables ( 202 , 204 from FIG. 2 ) are remotely located in multiple locations, the classifier can be employed to determine which location will be selected for comparison.
[0103] A classifier is a function that maps an input attribute vector, x=(x1, x2, x3, x4, xn), to a confidence that the input belongs to a class, that is, f(x)=confidence(class). Such classification can employ a probabilistic and/or statistical-based analysis (e.g., factoring into the analysis utilities and costs) to prognose or infer an action that a user desires to be automatically performed.
[0104] A support vector machine (SVM) is an example of a classifier that can be employed. The SVM operates by finding a hypersurface in the space of possible inputs, which hypersurface attempts to split the triggering criteria from the non-triggering events. Intuitively, this makes the classification correct for testing data that is near, but not identical to training data. Other directed and undirected model classification approaches include, e.g., naïve Bayes, Bayesian networks, decision trees, neural networks, fuzzy logic models, and probabilistic classification models providing different patterns of independence can be employed. Classification as used herein also is inclusive of statistical regression that is utilized to develop models of priority.
[0105] As will be readily appreciated from the subject specification, the subject invention can employ classifiers that are explicitly trained (e.g., via a generic training data) as well as implicitly trained (e.g., via observing user behavior, receiving extrinsic information). For example, SVM's are configured via a learning or training phase within a classifier constructor and feature selection module. Thus, the classifier(s) can be used to automatically learn and perform a number of functions, including but not limited to determining according to a predetermined criteria.
[0106] Referring now to FIG. 8 , there is illustrated a block diagram of a computer operable to execute the disclosed architecture. In order to provide additional context for various aspects of the subject invention, FIG. 8 and the following discussion are intended to provide a brief, general description of a suitable computing environment 800 in which the various aspects of the invention can be implemented. While the invention has been described above in the general context of computer-executable instructions that may run on one or more computers, those skilled in the art will recognize that the invention also can be implemented in combination with other program modules and/or as a combination of hardware and software.
[0107] Generally, program modules include routines, programs, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the inventive methods can be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, minicomputers, mainframe computers, as well as personal computers, hand-held computing devices, microprocessor-based or programmable consumer electronics, and the like, each of which can be operatively coupled to one or more associated devices.
[0108] The illustrated aspects of the invention may also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.
[0109] A computer typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by the computer and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer-readable media can comprise computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital video disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer.
[0110] Communication media typically embodies computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism, and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of the any of the above should also be included within the scope of computer-readable media.
[0111] With reference again to FIG. 8 , the exemplary environment 800 for implementing various aspects of the invention includes a computer 802 , the computer 802 including a processing unit 804 , a system memory 806 and a system bus 808 . The system bus 808 couples system components including, but not limited to, the system memory 806 to the processing unit 804 . The processing unit 804 can be any of various commercially available processors. Dual microprocessors and other multi-processor architectures may also be employed as the processing unit 804 .
[0112] The system bus 808 can be any of several types of bus structure that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. The system memory 806 includes read-only memory (ROM) 810 and random access memory (RAM) 812 . A basic input/output system (BIOS) is stored in a non-volatile memory 810 such as ROM, EPROM, EEPROM, which BIOS contains the basic routines that help to transfer information between elements within the computer 802 , such as during start-up. The RAM 812 can also include a high-speed RAM such as static RAM for caching data.
[0113] The computer 802 further includes an internal hard disk drive (HDD) 814 (e.g., EIDE, SATA), which internal hard disk drive 814 may also be configured for external use in a suitable chassis (not shown), a magnetic floppy disk drive (FDD) 816 , (e.g., to read from or write to a removable diskette 818 ) and an optical disk drive 820 , (e.g., reading a CD-ROM disk 822 or, to read from or write to other high capacity optical media such as the DVD). The hard disk drive 814 , magnetic disk drive 816 and optical disk drive 820 can be connected to the system bus 808 by a hard disk drive interface 824 , a magnetic disk drive interface 826 and an optical drive interface 828 , respectively. The interface 824 for external drive implementations includes at least one or both of Universal Serial Bus (USB) and IEEE 1394 interface technologies. Other external drive connection technologies are within contemplation of the subject invention.
[0114] The drives and their associated computer-readable media provide nonvolatile storage of data, data structures, computer-executable instructions, and so forth. For the computer 802 , the drives and media accommodate the storage of any data in a suitable digital format. Although the description of computer-readable media above refers to a HDD, a removable magnetic diskette, and a removable optical media such as a CD or DVD, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as zip drives, magnetic cassettes, flash memory cards, cartridges, and the like, may also be used in the exemplary operating environment, and further, that any such media may contain computer-executable instructions for performing the methods of the invention.
[0115] A number of program modules can be stored in the drives and RAM 812 , including an operating system 830 , one or more application programs 832 , other program modules 834 and program data 836 . All or portions of the operating system, applications, modules, and/or data can also be cached in the RAM 812 . It is appreciated that the invention can be implemented with various commercially available operating systems or combinations of operating systems.
[0116] A user can enter commands and information into the computer 802 through one or more wired/wireless input devices, e.g., a keyboard 838 and a pointing device, such as a mouse 840 . Other input devices (not shown) may include a microphone, an IR remote control, a joystick, a game pad, a stylus pen, touch screen, or the like. These and other input devices are often connected to the processing unit 804 through an input device interface 842 that is coupled to the system bus 808 , but can be connected by other interfaces, such as a parallel port, an IEEE 1394 serial port, a game port, a USB port, an IR interface, etc.
[0117] A monitor 844 or other type of display device is also connected to the system bus 808 via an interface, such as a video adapter 846 . In addition to the monitor 844 , a computer typically includes other peripheral output devices (not shown), such as speakers, printers, etc.
[0118] The computer 802 may operate in a networked environment using logical connections via wired and/or wireless communications to one or more remote computers, such as a remote computer(s) 848 . The remote computer(s) 848 can be a workstation, a server computer, a router, a personal computer, portable computer, microprocessor-based entertainment appliance, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer 802 , although, for purposes of brevity, only a memory/storage device 850 is illustrated. The logical connections depicted include wired/wireless connectivity to a local area network (LAN) 852 and/or larger networks, e.g., a wide area network (WAN) 854 . Such LAN and WAN networking environments are commonplace in offices and companies, and facilitate enterprise-wide computer networks, such as intranets, all of which may connect to a global communications network, e.g., the Internet.
[0119] When used in a LAN networking environment, the computer 802 is connected to the local network 852 through a wired and/or wireless communication network interface or adapter 856 . The adaptor 856 may facilitate wired or wireless communication to the LAN 852 , which may also include a wireless access point disposed thereon for communicating with the wireless adaptor 856 .
[0120] When used in a WAN networking environment, the computer 802 can include a modem 858 , or is connected to a communications server on the WAN 854 , or has other means for establishing communications over the WAN 854 , such as by way of the Internet. The modem 858 , which can be internal or external and a wired or wireless device, is connected to the system bus 808 via the serial port interface 842 . In a networked environment, program modules depicted relative to the computer 802 , or portions thereof, can be stored in the remote memory/storage device 850 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers can be used.
[0121] The computer 802 is operable to communicate with any wireless devices or entities operatively disposed in wireless communication, e.g., a printer, scanner, desktop and/or portable computer, portable data assistant, communications satellite, any piece of equipment or location associated with a wirelessly detectable tag (e.g., a kiosk, news stand, restroom), and telephone. This includes at least Wi-Fi and Bluetooth™ wireless technologies. Thus, the communication can be a predefined structure as with a conventional network or simply an ad hoc communication between at least two devices.
[0122] Wi-Fi, or Wireless Fidelity, allows connection to the Internet from a couch at home, a bed in a hotel room, or a conference room at work, without wires. Wi-Fi is a wireless technology similar to that used in a cell phone that enables such devices, e.g., computers, to send and receive data indoors and out; anywhere within the range of a base station. Wi-Fi networks use radio technologies called IEEE 802.11(a, b, g, etc.) to provide secure, reliable, fast wireless connectivity. A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet). Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, at an 11 Mbps (802.11a) or 54 Mbps (802.11b) data rate, for example, or with products that contain both bands (dual band), so the networks can provide real-world performance similar to the basic 10BaseT wired Ethernet networks used in many offices.
[0123] Referring now to FIG. 9 , there is illustrated a schematic block diagram of an exemplary computing environment 900 in accordance with the subject invention. The system 900 includes one or more client(s) 902 . The client(s) 902 can be hardware and/or software (e.g., threads, processes, computing devices). The client(s) 902 can house cookie(s) and/or associated contextual information by employing the invention, for example.
[0124] The system 900 also includes one or more server(s) 904 . The server(s) 904 can also be hardware and/or software (e.g., threads, processes, computing devices). The servers 904 can house threads to perform transformations by employing the invention, for example. One possible communication between a client 902 and a server 904 can be in the form of a data packet adapted to be transmitted between two or more computer processes. The data packet may include a cookie and/or associated contextual information, for example. The system 900 includes a communication framework 906 (e.g., a global communication network such as the Internet) that can be employed to facilitate communications between the client(s) 902 and the server(s) 904 .
[0125] Communications can be facilitated via a wired (including optical fiber) and/or wireless technology. The client(s) 902 are operatively connected to one or more client data store(s) 908 that can be employed to store information local to the client(s) 902 (e.g., cookie(s) and/or associated contextual information). Similarly, the server(s) 904 are operatively connected to one or more server data store(s) 910 that can be employed to store information local to the servers 904 . What has been described above includes examples of the invention. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the subject invention, but one of ordinary skill in the art may recognize that many further combinations and permutations of the invention are possible. Accordingly, the invention is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. | A system that generates a per user abstraction of a store from a connection point. Filtering a view set of a hierarchically secured containment hierarchy based on the access permissions of the principal is one of the novel features of the invention. The invention can offer a collection of primitives that can operate on this aggregation that span multiple container hierarchies with potentially heterogeneous security descriptors. The model can reduce the necessity to traverse the container hierarchy to discover all the accessible items in a domain. | 8 |
FIELD OF THE INVENTION
The present invention relates to chip identification using hardware intrinsic keys and authentication responses, and methods and circuits required to generate a unique identifying string to identify the chip.
BACKGROUND AND RELATED ART
The reliably of self-identifying chips have become a necessity in contemporary security and encryption applications. It is known in the art that there is a need for a secret key storage in the semiconductor industry, and further, wherein the cost is the top barrier that must be addressed to increase the adoption of the secret key storage and hardware intrinsic security. In addition, a unique identification of a specific device is a dominant reason given by survey participants for adopting secret key storage.
According, and particularly for fabless semiconductor design companies, there is a critical need in industry for a cost-effective solution to internal and external IC clients that provides chip authentication and identification with minimal design and area overhead. The solution requires a minimum amount of additional circuitry or mask levels on the chip, and sufficiently simple that they do not impact the yield, and it being adaptable to a broad range of products.
Process variations in a VLSI chip can originate unique electrical fingerprints, and these constitute a secure approach to chip security known as Physically Unclonable Functions (PUFs).
Several methodologies, mechanisms, and systems can be employed to allow intrinsic features of a computer chip or integrated circuit (IC) to be used to generate one or more unique and difficult to replicate IDs corresponding to the chip or IC. In one implementation for determining a unique intrinsic ID of a chip is described in U.S. Patent Application 2013/0133031 A1, titled “Retention Based Intrinsic Fingerprint Identification Featuring A Fuzzy Algorithm And A Dynamic Key” by Fainstein et al., published Can 23, 2013, of common assignee, is incorporated herein by reference in its entirety.
An additional implementation of determining a unique intrinsic ID of a chip is described in “Field Tolerant Dynamic Intrinsic Chip ID Using 32 nm High-K/Metal Gate SOI Embedded DRAM” by Rosenblatt et al., published in the IEEE Journal of Solid-State Circuits, Vol. 48, No. 4, April 2013, of common assignee, is incorporated herein by reference in its entirety.
A further implementation of determining a unique intrinsic ID of a chip is described in “Improved Circuits for Microchip Identification using SRAM Mismatch” by Chellappa, et al., Custom Integrated Circuits Conference (CICC), 2011 IEEE, of common assignee, is incorporated herein by reference in its entirety.
A further implementation of determining a unique intrinsic ID of a chip is described in “Physical Unclonable Functions for Device Authentication and Secret Key Generation” by Suh et al., Proceedings of the 44 th Annual Design Automation Conference (ACM), 2007, of common assignee, is incorporated herein by reference in its entirety.
The challenges for a PUF based ID approaches reside in providing the intrinsic ID function to generate the PUF ID with minimum chip overhead while giving stable generation.
SUMMARY
Accordingly, in an embodiment of the invention, a method and a system are described for providing VLSI chips and a system that generates an unclonable intrinsic identification using a NOR type memory array to achieve ID security and high accuracy of authentication.
In another embodiment, a system and a method are provided for identifying a chip that employs intrinsic parameters of memory cells invariant and unique to the chip over its lifetime.
In still another embodiment, a chip is uniquely identifies by using a random bitmap pattern on a plurality of memory cells, each having transistors in a memory array. A low-cost solution is provided that is compared to a 6 conventional transistors SRAM based PUF and a DRAM based PUF that provides a simpler solution than the SRAM and DRAM based PUFs for generating a random bit pattern.
In a further embodiment, a charge trap memory having each a transistor, wherein a random bit pattern is generated by using a non-charge-trapped transistor in said charge trap memory array.
In yet a further embodiment, the chip uniquely identifies a chip by using a random bitmap pattern using a plurality of the memory cells, each having a pair of transistors in a memory array. The method provides a further simpler solution than the SRAM and DRAM based PUFs for generating a random bit pattern.
In still another embodiment, a charge trap memory is used, each having a pair of transistors, wherein a random bit pattern is generated by using a pair of the non-charge-trapped transistors in said charge trap memory.
In a further embodiment, a charge trap memory array includes a plurality of memory cells, wherein said memory cells are assigned for PUF bit generation using a non-charge-trap memory cell and error correction non-volatile bit storage using charge-trap memory cell in said charge trap memory array such that the generated PUF bits are corrected by error correction non-volatile bits, resulting in a stable PUF generation.
In still a further embodiment, a charge trap memory array includes a plurality of memory cells, wherein said memory cells are assigned to a PUF bit generation using a non-charge-trap memory cell and public ID bits using a charge-trap memory cell in said charge trap memory array. The method provides a dynamic PUF generation for secure authentication by chip and system handshaking steps, wherein (1) the system requests a public ID to the corresponding chip, (2) the chip responds to the public ID to the system, (3) the system challenges the chip using the public ID, (4) the chip generates and sends the PUF using the challenge, and (5) system authenticates whether the generated PUF is same as the system record.
In yet a further embodiment, a method provides an unclonable identifying chip that includes forming a memory array consisting of memory cells arranged in a matrix, each of the memory cells having one transistor, wherein the transistors in each row are coupled to a wordline, and the transistors in each column are coupled to a bitline and to a source line; activating the wordline and forcing a bitline voltage to a first voltage, floating the bitline followed by precharging the bitline through the transistor coupling to the activated wordline, and sensing the bitline voltage, wherein random binary strings are generated by sensing results of the bitline voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood and appreciated more fully from the following detailed description of the invention, taken in conjunction with the accompanying drawings of which:
FIG. 1 shows a schematic diagram of a NOR type memory array having a single transistor per bit for generating a random bit pattern as PUF.
FIG. 2 shows a detailed schematic and a timing diagram of the NOR type array in one column shown in FIG. 1 , wherein a sense amplifier compares the BL voltage to a reference voltage for generating a random bit pattern due to intrinsic distribution of the cell threshold voltage (VT).
FIG. 3 shows a schematic diagram of a NOR type memory array having a pair of two transistors for generating a random bit pattern as PUF.
FIG. 4 shows a detailed schematic and timing diagram of the NOR type array in one column seen in FIG. 3 , wherein a sense amplifier compares the pair of BL voltages that generates a random bit pattern due to intrinsic distribution of the threshold voltage (VT) of the pair of cells.
FIG. 5 shows the mask layout of the NOR type memory array.
FIG. 6 shows a charge trap memory cell.
FIG. 7 illustrates a measured source-to-drain current (IDS) with respect to the gate-to-source voltage of an NMOS transistor.
FIG. 8 illustrates a 144 Kb array consisting of 144K memory cells, each having two NMOS arranged in 128 rows by 144 columns.
FIG. 9 illustrates a 144 Kb array consisting of 144K memory cells each having two NMOS arranged in 128 rows by 144 columns, and where domain A and domain B are assigned for PUF bits and error correction bits, respectively.
FIG. 10 shows voltage conditions for programming, and resetting the memory cells.
FIG. 11 shows the detailed of 144 Kb memory array seen in FIG. 9 .
FIG. 12 shows a schematic diagram of the memory array, wherein the memory cells in domain A are assigned for a PUF generation with non-programmed cells with the memory cells in domain B being assigned to a non-volatile public ID with programmed cells.
FIG. 13 shows a handshake authentication method using a NOR type memory array with public ID and PUF ID, wherein the challenge to the chip is unique to each corresponding chip, dynamically changing at each authentication to improve the HW security.
DETAILED DESCRIPTION
Detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely illustrative of the invention that can be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention is intended to be illustrative, and not restrictive.
FIG. 1 shows an embodiment illustrating a transistor level schematic for a PUF bit generation core ( 100 ). Array ( 101 ) consists of a plurality of NMOS devices ( 110 ) arranged in a two dimensional matrix. The gate of the NMOSs ( 110 ) in a row is coupled to wordline (WL) running in the horizontal direction. The drain of NMOSs ( 110 ) in a column is coupled to the corresponding bitline (BL) running in a vertical direction. The source of all the NMOSs is coupled to a source-line (SL). SL is biased at a voltage supply (VDD). The array structure ( 100 ) results in a NOR type array having the NMOS parallel connection to the BL in each column. The NMOSs in the NOR type array is controlled by a wordline driver (not shown), bitline drivers ( 130 ), and sense amplifiers ( 120 ). The sense amplifiers ( 120 ) are coupled to BLs, and a reference voltage (VREF) generated by a reference voltage generator ( 140 ) for generating a random bit pattern.
FIG. 2 shows a detailed circuit and a timing diagram for column ( 200 ) in FIG. 1 . Sense amplifier ( 120 j ) is coupled to BL and VREF voltage. BL is precharged at VDD in precharged state (PR) prior to the PUF generation. The source line SL is precharged to VDD. The PUF generation (active state: ACT) starts by disabling the precharging operation, and activates the corresponding WL selected by the address similar to a conventional memory. A signal pulsed WL (PWL) is likewise also activated. When WL and PWL are raised to VDD, one of the NMOS in each column discharges the BL to a pre-determined voltage (lower than VDD) preferably GROUND (GND), or 0V. The signal PWL then goes low, disabling the BL driver ( 130 j ), and floating BL. Thus, it naturally charges the BL through the selected NMOS ( 110 ) by a corresponding activated WL (WLi). As BL goes high because of the source follower mode of the NMOS device operation, the gate overdrive to WL and to BL is reduced, and eventually disables the NMOS ( 110 ), shown in the timing diagram, resulting in generating a VDD minus NMOS device threshold voltage (VTi) on the BL. The reference voltage generator ( 140 ) uses the same device employed for the NMOS memory cell to generate the reference voltage (VREF) of VDD−VT R . Because of the intrinsic distribution of the NMOS VTs (VTi and VT R ), the generated BL voltage (=VDD−VTi) and (VREF=VDD−VT R ) depends on the intrinsic VT in the hardware. The differential voltage (VTi−VT R ) of BL and REF is preferably sensed by a differential sense amplifier ( 120 j ). This results in a random digital bit generation (high or low) as an output ( 122 ) of the sense amplifier ( 120 j ). Following the generation, the WL goes low, and BL is precharged to VDD, returning to a precharge state (PR).
In a first preferred embodiment, it allows to generate one random bit per transistor. However, relaying on the reference voltage (VREF) can cause a random bit pattern skew to 0 or to 1 if VT R of the VREF generator has a significant offset from the mean of the NMOS VT distribution. For example, if VREF is too low due to the high VT R of the VREF generator, the generated bit is more likely a 0 (skewing to 0).
FIG. 3 shows a second preferred embodiment illustrating a transistor level schematic for a PUF bit generation core ( 300 ). The array ( 301 ) consists of a plurality of memory cells ( 310 ), each having two transistors ( 310 A and 310 B) to overcome the skewing problem. The array structure ( 301 ) coincides with the array ( 101 of FIG. 1 ) but at one-half density of the array ( 102 ) because of the two transistor assignments per cell. These are supported by wordline drivers (not shown) coupling to the wordlines (WLs), and sense amplifiers ( 320 ), bitline drivers ( 330 ) coupling to bitlines (BLs). Unlike the first approach, a random bit is generated by an intrinsic VT distribution of the pair ( 310 A and 310 B) of a cell ( 310 ).
FIG. 4 shows a detailed circuit and timing diagram of one column ( 400 in FIG. 3 ). The Sense amplifier ( 320 j ) is coupled to a bitline true (BLt) and to a bitline complement (BLc), each coupling to the cells ( 310 A) and ( 320 B) in a column. Both BLt and BLc are precharged to VDD in a precharged state (PR) prior to the PUF generation. The source-line (SL) is likewise precharged to VDD. The PUF generation (active state: ACT) starts by disabling the BL precharge operation, and activating the corresponding WL selected by an address similar to a conventional memory. A signal that pulses WL (PWL) is also activated. When WL and PWL are raised to VDD, the selected NMOS pair in each column discharges BL to a predetermined voltage (i.e., lower than VDD), and preferably to GND, or 0V. The signal PWL then goes low, disabling the BL driver transistors ( 330 j ), and floating BLt and BLc. Thus, it naturally charges BLt and BLc through the selected NMOS pair ( 310 A and 310 B) by the corresponding activated WL (WLi). As BLt and BLc go high because of the source follower mode of the NMOS device operation ( 310 A and 310 B), the gate overdrive to WL to BLt and to BLc are reduced, eventually disabling the NMOS, as shown in the timing diagram. This results in having the voltage of VDD minus the NMOS device threshold voltage (VT) on each BLt and BLc. Because of the intrinsic distribution of the NMOS VTs (VTA for 310 NMOS and VTB for 310 B NMOS), the BLt voltage (VDD−VTA) and BLc voltage (VDD−VTB) depends on a corresponding NMOS of the pair, which creates a differential voltage into the BL pair. The differential voltage is amplified by the differential sense amplifier ( 320 j ), resulting in a random digital bit generation as output ( 322 ) of the sense amplifier ( 320 j ). After the generation, WL goes low, and BLt and BLc are precharged to VDD, returning to a precharge state (PR).
FIG. 5 shows the mask layout of a NOR type memory array ( 500 or 301 in FIG. 3 ) having a plurality of memory cells ( 510 ), each having a NMOS pair ( 510 A and 510 B pair is equal to 310 A and 310 B in FIG. 3 ), wherein the source line (SL) relies on the VDD voltage. The same array structure can be used for the first approach of the array ( 101 ) (shown in FIG. 1 ) having a plurality of NMOS ( 110 in FIG. 1 ), by assigning BLt and BLc to the independent BL. As shown in FIG. 3 , wordlines (WL) run horizontally using poly (PC), with BLt and BLc pairs and VDD reaching SLs running vertically using M2. SLs can likewise run horizontally, creating a mesh structure. By way of example, two wordlines are used for activating two finger devices as a WL, although one PC can be used for one WL.
The NOR type array referred to in the first and second embodiments can be used for creating a charge trap memory by trapping the change to the NMOS memory cell ( 110 ) in FIG. 1 , or 310 in FIG. 3 .
Referring to FIG. 6 , a basic charge trap used on an embodiment is illustrated. A charge trap can be observed in a high performance logic NMOS. The NMOS has an initial threshold voltage of VT 0 . NMOS VT 0 that can be increased to VT by trapping a number of electrons (e−) to the vacancy of oxygen (O 2 ) in the dielectric ( 640 ) of NMOS ( 600 ). The vacant oxygen point ( 640 D) in Hf 4 oxide ( 640 ) traps electrons ( 640 A) in condition of applying a high voltage to the gate ( 610 ) while applying a high voltage between the source ( 620 ) and the drain ( 630 ) such that the NMOS strongly turns on to flow a large current through the channel ( 650 ). The trapped charges (e−) increase the NMOS threshold voltage to VT 1 (=VT 0 +ΔVT). Moreover, the trapped electrons (e−) ( 540 B) can be eliminated by applying a negative voltage between the gate ( 510 ) and the source ( 520 ), recovering the VT 0 condition.
Referring to FIG. 7 , the measured drain of source to current (IDS) with respect to the gate to source voltage (VGS) of the Hf 4 NMOS transistor ( 600 ) is illustrated in FIG. 6 . IDS can be measured while trapping and detrapping the charge several times. As expected, trapping electrons increases the NMOS threshold, resulting in a smaller current than without trapping. The VT 1 of the charge trapped NMOS can be successfully reset to VT 0 of a non-charge trapped NMOS.
A third preferred embodiment uses the charge trap believer in the array ( 101 ) or array ( 301 ) referred to in the first and second preferred embodiments to enable a more stable PUF generation using error-correction bits with an additional voltage control. Referring to FIG. 8 , the macro architecture ( 800 ) is shown for a stable PUF generation consisting of the NOR-type NMOS array ( 810 ), a wordline decoder block ( 850 : WLDEC), a bitline decoder block ( 830 : BLDEC) and a sense amplifier block ( 820 SA). In another embodiment, the NOR-type NMOS array ( 810 ) can include a plurality of memory cells, each having a true bit of NMOS and a complement bit of NMOS for a 144 Kb density. More specifically, 144 Kb array consists of 144K memory cells ( 810 ), each having two NMOS ( 810 _ t and 810 _ c ) arranged in 256 rows coupled to 256 wordlines (WLs) and 144 columns coupled to 144 bitline true (BLt) and bitline complement (BLc) pairs in a two dimensional matrix. The drains of the twin NMOS are coupled to the Source-Line (SL). The BLs are precharged at the voltage source (VDD=1V) in standby state. The SLs in the entire array are precharged at the voltage source (VDD=1V) in a standby and random bit generation.
FIG. 9 shows a schematic of a Stable PUF generation memory MACRO (SPUFMACRO). SPUFMACRO ( 900 ) is configured in two domains A and B in the memory array ( 910 ), wherein the memory cells in domains A ( 910 A) and B ( 910 B) are used for the physical unclonable fuse (PUF) bit generation, and the error-correction-code (ECC), respectively. More specifically, the memory cells ( 912 A) in domain A ( 910 A) do not trap a charge in neither NMOS ( 912 A_t and 912 A_c). The memory cells ( 912 B) in domain B ( 910 B) traps the charge in either the NMOS ( 912 B_t and 912 B_c) to program the error correction code (ECC) bits, in a programming method to be referred hereinafter.
When a random bit generation is to be enabled, one out of 256 WLs is activated by wordline decoder block (not shown). This results in selecting 144 columns coupled to the activated WL (WLi), wherein 128 bits are used for random bit generation, and 16 bits are for the ECC bits for correcting the generated 128 bits. BLt and BLc are then discharged to GND by the bitline driver block ( 930 ). The discharge operation stops after a few nanoseconds, floating the BLt and BLc. Thus, BLt and BLc are naturally precharged through the selected NMOS pair ( 912 A and 912 B) coupling to the activated WL (WLi). As BLt and BLc go high because of the source follower mode of the NMOS device operation ( 912 A and 912 B), the gate overdrive to WL to BLt and to BLc is reduced, eventually disables NMOS, as shown in the corresponding timing diagram. This results when generating VDD minus NMOS device threshold voltage (VT) on each BLt and BLc. Because the intrinsic distribution of the NMOS VTs in un-programmed memory cells ( 912 A) in domain A, a differential voltage between the BLt and BLc depends on the column. The BL voltage is thus converted to a random digital bit pattern ( 922 ) by sense amplifiers ( 920 ). In the random bit pattern generation, some of the bits are not stable if the generated BL differential voltage is small. To overcome this problem, generated bits ( 922 ) are coupled to the ECC logic ( 960 ), generating ECC bits (970 ECC). In the present example, 16 ECC bits are prepared to correct one out of 128 PUF bits. However, a correction bit can be increased for repairing a significantly more powerful correction, which is known in the art and therefore will not be referred to in the application.
For programming the corresponding ECC bits, WL is raised to an elevated wordline voltage (EWLH=2V). Prior to the WL activation, BLs and SL in the entire array are raised to an elevated bitline voltage (EBLH=1.5V). The bitline decoder block ( 930 : BLDEC), and then selects 16 columns in domain B such that either BLt or BLc in each sECC column is discharged to ground (GND). This results in a large current flow to trap the charge for the corresponding selected either NMOS ( 912 B_t) or NMOS ( 912 B_c). When NMOS ( 912 B_t) is selected, the VT of the NMOS ( 912 N_t) is increased by ΔVT, resulting in a ‘1’ write. When NMOS ( 912 B_c) is selected, VT of NMOS ( 912 _ c ) is increased by ΔVT, resulting in a ‘0’ write. The written bits to the ECC are determined by the ECC bits ( 924 ) generated by the ECC logic ( 960 ). The BLs ( 912 A_t and 912 A_c) remain at EBLH of 1.5V, resulting in no current flowing though the memory cells ( 912 A) in domain A. Therefore, the intrinsic random VT in the NMOS ( 912 A and 912 B) is kept for PUF bit generation.
Following the programming of the ECC bits in the memory cells ( 912 B) in domain B, the differential bitline voltage on the columns in the domain B is sufficiently large, generating stable ECC bits. This results in one out of 128 bits correction during the random PUF bit generation using 16 ECC bits.
Because of the charge trap based ECC bit programming, the ECC bits can be reset. The remaining operation is enabled by lowering WLs in the entire array to a negative wordline voltage (NWLL=−1V), while keeping BL and SL precharged at 1V. This results in applying a negative gate-to-source voltage (VGS=−2V) of all the NMOSs in the array 910 ). The trapped charge is detrapped, recovering the initial VT of the entire memory cells ( 912 B).
FIG. 10 summarizes the voltage condition for a standby ECC programming, PUF generation (random bit pattern generation), and ECC reset mode. FIG. 11 shows the overall macro ( 1100 ) having a 144 Kb array ( 1110 ), domain A ( 1110 A) for PUF generation, and domain B ( 1110 B) for ECC bit generation. Both are supported by the wordline decoder (WLDEC) to select one out of 256 WLs selection in a random bit generation, as well as ECC bit programming. They are also supported by the bitline decoder ( 1130 ), sense amplifier block (SA 1120 ), and ECC logic ( 1160 ). As shown, the memory cell in domain A ( 1110 A) does not trap the charge, generating a random pattern output as a PUF from the SA ( 1122 A). The unstable generated PUF is corrected by the stable ECC bit output from SA ( 1122 B) coupled to the memory cells having either a true or a complement NMOS traps the charge to store the ECC bit. This results in a stable random bit string ( 1170 ) as an output vector of the ECC logic ( 1160 ).
The charge trap based PUF generation macro can incorporate a public ID within the array which allows a secret challenge approach for authentication. In a fourth preferred embodiment, while still referring to FIG. 11 , the charge trap PUF generation macro ( 1200 ) consists of a charge trapped memory array ( 1210 ) having two domains, wherein the memory cell in domains ( 1210 A) and ( 1210 B) are used for PUF bit generation, and public ID, respectively. The domain A further consists of a plurality of sub-domains (i.e., A, K). The size of the domain can be variable. As referred previously, intrinsic random bits are generated by reading from the memory cells in the domain ( 1210 A), each having two transistors (t and c) without trapping a charged trap. This results in a random bit generation as a PUF because of the intrinsic VT variation of the two transistors (t and c) of each cell. Public ID is programmed to identify the chip by trapping a charge to either one of the two transistors of each cell in the domain ( 1210 B) using the charge-trap referred previously for the ECC bit programming. Macro ( 1200 ) can include ECC Cbit for generating a stable PUF, as referred to in the previous preferred embodiment.
Referring to FIG. 13 , a high security authentication is enabled by a handshaking method using public ID and intrinsic ID binary bits between the computer and the chip. More specifically, the high security system ( 1300 ) consists of computer ( 1350 ) and the chip including a charge-trap based PUF generation ID macro ( 1320 ). The computer ( 1350 ) includes a database which records the public chip ID (PID), and the corresponding intrinsic ID binary strings (IID) as PUF. PID (01001 . . . 0) and IID (K) are stored in secure enjoinment when the chip is registered. The IID of K includes the selected sub-domain (K) used for IID PUF generation.
In order to authenticate the chip, the computer ( 1350 ) requests a PID read ( 1302 ) to the chip ( 1320 ). The control circuit ( 1340 ) in the chip requests to read the PID from the macro array ( 1330 ) by control command 1312 . This results in generating a PID ( 1306 i.e. 01001 . . . 0). PID is then sent to the computer ( 1350 ). The database in the computer ( 1350 ) searches the chip having the PID. The computer ( 1350 ) then requests an Intrinsic ID (IID) generation ( 1304 ) for one of the sub-domains (i.e., K) to the chip. On the basis of the sub-domain information, the controller ( 1340 ) requests the macro ( 1330 ) to generate IID binary strings ( 1308 ) in the sub-domain K. The IID binary strings are transferred to the computer ( 1350 ). The computer ( 1350 ) confirms that the IID binary strings are the same as the data base record, outputting the result ( 1310 ) “authenticated when confirmed”, or “not authenticated when not confirmed”. A unique secret sub-domain is then assigned to each chip, resulting in a secure system. The secret sub-domain can be dynamically changed in each authentication by using a plurality of IID, each corresponding to some sub-domains, which further improves the hardware security.
While the present disclosure has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details can be made without departing from the spirit and scope of the present disclosure. In one therefore intended that the present disclosure not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims. | A method for identifying an unclonable chip uses hardware intrinsic keys and authentication responses employing intrinsic parameters of memory cells invariant and unique to the unclonable chip, wherein intrinsic parameters that characterize the chip can extend over its lifetime. The memory cells having a charge-trap behavior are arranged in an NOR type memory array, allowing to create a physically unclonable fuse (PUF) generation using non-programmed memory cells, while stringing non-volatile bits in programmed memory cells. The non-volatile memory cell bits are used for error-correction-code (ECC) for the generated PUF. The invention can further include a public identification using non-volatile bits, allowing hand shaking authentication using computer with dynamic challenge. | 6 |
FIELD OF THE INVENTION
The present disclosure relates to a small computing device having a light source. More particularly, the disclosure relates to a personal digital assistant having a light source that can be used to illuminate the user's surroundings where little ambient light exists.
BACKGROUND OF THE INVENTION
Personal computing devices have become very popular in recent years. Many persons use these devices to keep track of various information including their contact information (including phone numbers, addresses, etc.) and their calendar (including scheduled appointments, meetings, etc.). Due to the portability of such devices, many persons carry the devices with them nearly at all times. Accordingly, these persons normally have quick access to their computing devices.
Because of the convenience provided to users with personal computing devices, these devices are often viewed as a personal assistant on which the user can rely for several different purposes. Although several of these devices provide many different features, other useful features could be provided. For instance, in that the personal computing device is often carried with the user from place to place, it would be convenient if the device were provided with a light source such that the device could be used as a flashlight in low light conditions.
SUMMARY OF THE INVENTION
The present disclosure relates to a small computing device. In one arrangement, the device comprises an internal computer, a power source, and a light source that is adapted to emit light out from the small computing device to illuminate surroundings in which the small computing device is used.
In a preferred arrangement, the small computing device comprises a personal digital assistant that includes an internal computer including a processing device and memory, an internal battery, a display, at least one control button, and a light source that is adapted to emit light out from the personal digital assistant to illuminate surroundings in which the personal digital assistant is used.
The features and advantages of the invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention.
FIG. 1 is a schematic perspective view of example computing apparatus.
FIG. 2 is a block diagram identifying various components of a small computing device shown in FIG. 1 .
FIG. 3 is a schematic view of a computer identified in FIG. 2 .
FIG. 4 is a schematic perspective view illustrating use of the small computing device shown in FIG. 1 .
DETAILED DESCRIPTION
Disclosed herein is a small computing device that has a light source that can be used to illuminate the environment in which the device is used. As used herein, the term “small computing device” denotes portable computing devices of the type that can easily be carried by the user. Common names for such devices include, for instance, personal digital assistant (PDA), palmtop, pocket personal computer (PC), handheld PC, etc. As will be apparent from the discussion that follows, the small computing device is distinct from other devices that merely contain internal circuitry (e.g., calculator) in that the former are miniaturized versions of the common PC or laptop. Accordingly, small computing devices are actually minicomputers comprising many of the components commonly found in other, less portable computers.
To facilitate description of the invention, an example small computing device will be discussed with reference to the figures. Although this device is described in detail, it will be appreciated that the device is provided for purposes of illustration only and that various modifications are feasible without departing from the inventive concept. After the example small computing device has been described, its use will be discussed.
Referring now in more detail to FIG. 1, illustrated is example computing apparatus 100 . As shown in this figure, the apparatus 100 can comprise a small computing device 102 having an outer housing 106 . The housing 106 can be sized in shaped to fit within the palm of the user's hand (see FIG. 4 ). Although such a size and shape may be preferable in some embodiments, it will be appreciated that other sizes and/or shapes are possible.
The outer housing 106 is configured to accommodate a display 108 and one or more control buttons or keys 110 . By way of example, the display 108 comprises a liquid crystal display (LCD) and is used to convey various information to the user. Optionally, the display 108 can comprise a touch-sensitive LCD or other touch-sensitive display with which the user can make selections onscreen as well as enter information through use of a stylus 112 that, for instance, removably mounts to a rear side of the small computing device 102 . The control buttons 110 can, like the stylus 112 , be used to make selections and enter information into the small computing device 102 . By way of example, each button 110 can be preprogrammed for a particular purpose and/or one or more of the buttons can be programmable by the user so as to be usable as a “shortcut” key. The buttons 110 that are preprogrammed can be configured to, for instance, turn the power on and off, open a home menu, open a contacts list, open a calendar, open a tasks list, etc.
In addition to the display 108 and buttons 110 , the small computing device 102 can further include a speaker 114 and a signaling light emitting diode (LED) 116 , each of which can be used to alert the user as to a particular condition (e.g., time for a scheduled meeting). In addition, the speaker 114 can further be used for “playing” various recorded sounds (e.g., voice memoranda).
As is further identified in FIG. 1, the small computing device 102 also comprises a light source 118 and, at least in some embodiments, a light source control button 120 . The light source 118 typically is provided at a top end of the small computing device 102 such that the device can be used in similar manner to a flashlight as needed. The light source control button 120 , where provided, is normally positioned at a convenient location on the outer housing 106 so as to be easily accessible to the user when the small computing device 102 is used for illumination. For example, as shown in FIG. 1, the button 120 can be provided on a side of the housing 106 so as to be manipulable with the user's thumb (see FIG. 4 ). Notably, however, the location of the control button 120 , as well as the light source 118 , can be different in alternative arrangements within the skill of persons having ordinary skill in the art. As is described below, the light source control button 120 is connected to an internal switch that controls whether power is provided to the light source 118 .
As will be readily appreciated by persons having ordinary skill in the art, the small computing device 102 can possess many features beyond those described above in relation to FIG. 1 . For instance, the small computing device 102 can further include a data port used to electrically connect to another computing device (e.g., personal computer (PC)), a record button that is used to initiate and terminate recording of voice memoranda, a microphone that is used to record the memoranda, an “action” wheel that can be used to scroll through documents and menus, a transceiver that is adapted to wirelessly transmit data to and receive data from another computing device, a cover that is used to protect the display 108 , and so forth.
When the small computing device 102 is adapted to electrically connect to a PC, for example to synchronize with the PC and therefore share information with it, the apparatus 100 can further include a cradle or docking station 104 . As shown in FIG. 1, the cradle 104 can generally comprise a base 122 and a device support 124 . The base 122 typically comprises a substantially planar member that is adapted for placement on flat surfaces such as a desk. The device support 124 typically comprises a support wall 126 and, optionally, lateral support flanges 126 , which provide support to the small computing device 102 when it is disposed within the cradle 104 . Normally, the cradle 104 further includes a data connector 128 that is adapted to mate with an appropriate data port (not shown) of the small computing device 102 . By way of example, where the data port is provided on a bottom end of the small computing device 102 , the data connector 128 can be formed on an upper surface 130 of the device support 124 . In addition to these elements, the cradle 104 can include a connection cable (not shown) that is terminated with a connector which is adapted for connection to a PC.
Referring now to FIG. 2, illustrated is a block diagram of the architecture of the small computing device 102 . As shown in this figure, the small computing device 102 generally comprises an internal computer 200 that, as discussed below with reference to FIG. 3, provides the computing power of the small computing device. In addition, the device 102 comprises an internal power source 202 , the light source 118 illustrated in FIG. 1, and an internal switch 204 that is disposed between the power source and the light source so as to control operation of the light source. The power source 202 typically comprises a disposable or rechargeable battery. By way of example, the light source 118 can comprise an incandescent lamp. However, it is to be understood that the light source 118 can comprise substantially any element capable of generating sufficient light to illuminate the user's immediate surroundings. Therefore, the light source 118 can comprise, for example, a florescent lamp, halogen lamp, LED, or combinations thereof. The switch 204 can likewise take many different possible forms. For example, the switch 204 can comprise a simple on/off switch. In other embodiments, the switch 204 can be adapted to provide power to the light source 118 when the switch is placed in an on position and/or for as long as the user depresses the button 120 . Persons having ordinary skill in the art will appreciate that many different variations for both the light source 118 and switch 204 are feasible and may even be preferable in some embodiments.
FIG. 3 is a schematic view illustrating an example architecture of the internal computer 200 identified in FIG. 2 . As indicated in FIG. 3, the computer 200 can comprise a processing device 300 , memory 302 , user interface devices 304 , I/O devices 306 , and networking devices 308 . Each of these components is connected to a local interface 310 that, by way of example, comprises one or more internal buses. The processing device 300 is adapted to execute commands stored in memory 302 and can comprise a general-purpose processor, a microprocessor, one or more application-specific integrated circuits (ASICs), a plurality of suitably configured digital logic gates, and other well known electrical configurations comprised of discrete elements both individually and in various combinations to coordinate the overall operation of the small computing device 102 .
The user interface devices 304 typically comprise interface tools with which the device settings can be changed and through which the user can communicate commands directly to the small computing device 102 . As noted above, the display 108 (where touch-sensitive) and the buttons 110 can form part of the user interface devices 304 . The I/O devices 306 comprise components used to facilitate connection of the small computing device 102 to other devices, such as the cradle 104 and, as noted above, typically comprises a data port. By way of example, the I/O devices 306 can comprise one or more serial, parallel, small system interface (SCSI), universal serial bus (USB), IEEE 1394 (e.g., Firewire™), or personal area network (PAN) connection devices. Where provided, the networking devices 308 comprise the various components used to wirelessly transmit and/or receive data over a network. By way of example, the networking devices 308 include a device that communicates both inputs and outputs, for instance, a modulator/demodulator (e.g., modem), a transceiver (e.g., radio frequency (RF) or infrared (IR)), a telephonic interface, a network card, etc. Although particular examples of I/O devices 306 and networking devices 308 have been identified, it will be understood that these examples are provided for illustration only and that other options exist.
The memory 302 includes various software (e.g., firmware) programs including an operating system 312 , organizer software 314 , and various companion applications 316 . The operating system 312 contains the various commands used to control the general operation of the small computing device 102 . The organizer software 314 provides the basic utility of the small computing device 102 when acting in the capacity of a personal assistant. Accordingly, the organizer software 314 can include an address book 318 , calendar 320 , to do list 322 , and the like. As known in the art, several different software packages are currently available which offer such features. For example, a small computing device version of Microsoft Outlook™ is available under the name Pocket Outlook™. Where provided, the companion applications 316 comprise various programs suited for particular different functionalities. By way of example, these programs can include a word processing program (e.g., Microsoft Word™), spreadsheet program (e.g., Microsoft Excel™), financial tracking program (e.g., Microsoft Money™), game programs, etc.
Various software and/or firmware programs have been described herein. It is to be understood that these programs can be stored on any computer readable medium for use by or in connection with any computer related system or method. In the context of this document, a computer readable medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer related system or method. These programs can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “computer-readable medium” can be any means that can store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The computer readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a nonexhaustive list) of the computer-readable medium include an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Note that the computer-readable medium can even be paper or another suitable medium upon which a program is printed, as the program can be electronically captured, via for instance optical copying of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
An example small computing device 102 having been described above, operation of the device in illuminating the user's surroundings will now be discussed. As noted above, the light source 118 typically is positioned on the small computing device 102 so as to be conveniently positioned to shine light outwardly. When the device 102 is held in the same manner as a flashlight, the control button 120 is easily accessible by the user, for example with the user's thumb. This arrangement is depicted in FIG. 4 . As shown in this figure, the small computing device 102 can be held in the palm of the user's hand 400 such that the light 402 emitted by the source 118 can be directed away from the user's body. When held in this manner, the user can activate the control button 120 with the thumb 404 . Operating in this manner, the small computing device 102 can be used to illuminate the user's surroundings in low light conditions. As a consequence, the small computing device 102 is well-suited for use in an emergency in which the user needs light.
In another operating environment, the light source 118 can be controlled by entering selections with the user interface devices 304 , such as with the display 108 and/or buttons 110 . In such a scenario, the user opens an applicable control screen and can select “on” from the screen to cause power to be provided to the light source 118 . Where the light source 118 is activated in this manner, the user can further select a time period after which the light source will be automatically turned off to conserve power.
While particular embodiments of the invention have been disclosed in detail in the foregoing description and drawings for purposes of example, it will be understood by those skilled in the art that variations and modifications thereof can be made without departing from the scope of the invention as set forth in the following claims. | The present disclosure relates to a small computing device. In one arrangement, the device comprises an internal computer, a power source, and a light source that is adapted to emit light out from the small computing device to illuminate surroundings in which the small computing device is used. | 5 |
The present application claims the priority benefit of Korean Patent Application No. 10-2013-0134824 filed in Republic of Korea on Nov. 7, 2013, which is hereby incorporated by reference in its entirety for all purposes as if fully set forth herein.
BACKGROUND
1. Field of the Disclosure
The present disclosure relates to an array substrate, and particularly, an array substrate including an oxide semiconductor layer and a method of fabricating the same.
2. Discussion of the Related Art
Recently, facing an information laden society, a field of processing and displaying mass information has rapidly advanced, and many kinds of flat display devices are developed and highly favored.
As the flat display devices, liquid crystal display devices (LCDs), plasma display panel device (PDPs), field emission display devices (FEDs), electroluminescent display device (ELDs), organic light emitting diodes (OLEDs) are used. These display devices have advantages of thin profile, lightweight, and low power consumption, and are rapidly substituted for conventional cathode ray tubes (CRTs).
The flat display device typically includes an array substrate where a thin film transistor (TFT) as a switching element turning on/off a pixel is formed in each pixel.
For the purpose of explanation, an LCD most widely used among the flat display devices is illustrated in connection with the figures. The LCD has advantages of high performance in displaying moving images and high contrast ratio and is used for laptop computers, desktop monitors, TVs, or the like.
FIG. 1 is a cross-sectional view illustrating an array substrate for an LCD according to the related art.
Referring to FIG. 1 , the array substrate 10 includes a plurality of gate lines on a substrate 1 , and a plurality of data lines 15 crossing the gate lines to define a plurality of pixel regions P.
A TFT T is formed at a switching region near a crossing portion of the gate line and the data line 15 . A common electrode 21 and a pixel electrode 25 are also formed at a display region and used in displaying an image.
The TFT T includes a gate electrode 3 , a gate insulating layer 5 , an oxide semiconductor layer 7 , and source and drain electrodes 11 and 13 , respectively.
An etch stopper 9 is formed between the source and drain electrodes 11 and 13 and the oxide semiconductor layer 7 , and includes semiconductor contact holes 9 a exposing each of both side portions of the oxide semiconductor layer 7 . The source and drain electrodes 11 and 13 contact the respective side portions of the oxide semiconductor layer 7 through the respective semiconductor contact holes 9 a.
A first passivation layer 17 is formed on the entire surface of the substrate 1 having the TFT T, and a second passivation layer 19 is formed on the first passivation layer. The common electrode 21 is formed on the second passivation layer 19 corresponding to the entire display region and is made of a transparent conductive material.
A third passivation layer 23 is formed on the common electrode 21 . The first to third passivation layers 17 , 19 , and 23 include a drain contact hole 13 a exposing the drain electrode 13 .
The pixel electrode 25 is formed on the third passivation layer 23 in each pixel region P and contacts the drain electrode 13 through the drain contact hole 13 a.
The pixel electrode 25 includes a plurality of bar-shaped openings OP therein, and thus, produces a fringe electric field along with the common electrode 21 therebelow.
The above-described array substrate 10 is used for a fringe field switching mode LCD.
In the array substrate 10 , the oxide semiconductor layer 7 is reacted with hydrogen gas when depositing the first passivation layer 17 , and thus, hydrogen atoms act as a carrier in the oxide semiconductor layer 7 . This causes a problem in that the oxide semiconductor layer 7 then changes into a conductor. Further, the semiconductor layer 7 has an increase in propensity for oxygen vacancy generation due to ionic bonds, and this causes an increase of electron density.
Particularly, when forming the source and drain electrodes 11 and 13 , oxygen concentration at a back channel region after dry-etching or wet-etching remarkably decreases. Thus, the oxide semiconductor layer 7 changes into a conductor, and caused increased leakage in the TFT.
To solve the above problems, the etch stopper 9 is formed so that the oxide semiconductor layer 7 is not exposed to hydrogen gas during deposition of the first passivation layer 17 . However, this causes problems of more complicated design and processes with an associated increase of production costs.
Further, defect frequency increases, and thus, production efficiency is reduced.
Particularly, metal wire such as the source and drain electrodes is formed using low-resistance metal materials such as copper (Cu) in order to achieve display devices having large size and high resolution, and in this case, oxidation of metal wire is caused due to a high oxidation property of Cu and thus, leakage current occurs from the TFT. Therefore, reliability of the TFT element is reduced.
SUMMARY
Accordingly, the present disclosure is directed to an array substrate and a method of fabricating the same that can improve reliability of an oxide semiconductor and adjust properties of the oxide semiconductor to minimize deterioration, obtain production simplification by reducing production processes, prevent leakage current, and increase reliability of a TFT element by preventing oxidation of metal wire made of a material such as copper.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description and claims as well as the appended drawings.
To achieve these and other advantages, and in accordance with the purpose of the present disclosure, as embodied and broadly described herein, an array substrate includes a substrate; a gate electrode on the substrate; a gate insulating layer on the gate electrode; an oxide semiconductor layer on the gate insulating layer; source and drain electrodes on the oxide semiconductor layer; a silicide layer on the source and drain electrodes; and a first passivation layer on the source and drain electrodes.
In another aspect, a method of an array substrate includes forming a gate electrode, a gate insulating layer, an oxide semiconductor layer, source and drain electrodes, on a substrate; injecting a gas mixture containing silane (SiH 4 ) onto the source and drain electrodes to form a silicide layer on the source and drain electrodes; performing a surface treatment for a back channel region of the oxide semiconductor layer between the source and drain electrodes having the silicide layer thereon; and forming a first passivation layer on the source and drain electrodes.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure. In the drawings:
FIG. 1 is a cross-sectional view illustrating an array substrate for an LCD according to the related art;
FIG. 2 is a cross-sectional view illustrating an array substrate for an LCD according to an exemplary embodiment of the present disclosure;
FIGS. 3A to 3I are cross-sectional views illustrating the array substrate for the LCD according to the exemplary embodiment of the present disclosure;
FIGS. 4A and 4B are graphs illustrating transfer properties of TFTs including oxide semiconductor layers according to a comparative example and the exemplary embodiment of the present disclosure, respectively; and
FIG. 5A illustrates an occurrence of oxidation of metal wires using Cu not having silicide layer thereon; and
FIG. 5B , illustrates no occurrence of oxidation of metal wires using Cu and having the silicide layer thereon according to the exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings.
FIG. 2 is a cross-sectional view illustrating an array substrate for an LCD according to an embodiment of the present disclosure.
Referring to FIG. 2 , the array substrate 100 may include a plurality of gate lines (not shown) spaced apart from each other on a substrate 101 , and a plurality of data lines 115 crossing the plurality of gate lines to define respective pixel regions P.
A TFT T may be formed at a switching region TrA near a crossing portion of the gate line and the data line 115 , and a pixel electrode 125 may be formed at a display region to displaying an image.
A gate electrode 103 may be formed at the switching region TrA, and a gate insulating layer 105 may be formed on the entire surface of the substrate 101 having the gate electrode 103 .
An oxide semiconductor layer 107 may be formed on the gate insulating layer 105 over the gate electrode 103 . Source and drain electrodes 111 and 113 , respectively, may be formed on the oxide semiconductor layer 107 and spaced apart from each other.
The gate electrode 103 , the gate insulating layer 105 , the oxide semiconductor layer 107 , and the source and drain electrodes 111 and 113 form the TFT T at the switching region TrA.
A TFT T using an oxide semiconductor has field-effect mobility of several times to hundreds of times greater than that of a TFT using amorphous silicon.
For example, when an oxide semiconductor material containing at least one of zinc oxide, tin oxide, Ga—In—Zn oxide, and In—Sn oxide, which each have amorphous structure, or doped with at least one of Al, Ni, Cu, Ta, Mo, Hf, and Ti, can have field-effect mobility of at least 20 times greater than that of amorphous silicon.
Further, the oxide semiconductor layer 107 can have high mobility even though deposited at low temperature, and thus, reliability can be increased.
It is preferred, but not limited, that at least one of the gate electrode 103 , the gate line, the source and drain electrodes 111 and 113 , and the data line 115 have a multiple-layered structure, for example, double-layered structure that includes a lower layer made of one of Mo, Ti, and MoTi, and a upper layer made of low-resistance metal material such as Cu on the lower layer.
In this case, Mo, Ti, and MoTi have good adhesion onto the substrate 101 , e.g., made of glass material, and function to improve coupling of the Cu layer to the substrate 101 .
Further, using a multiple-layered structure with the Cu layer allows a width of signal wire to be reduced, and an increase of wire resistance can be prevented even though a length of the signal wire increases.
In this regard, to achieve an LCD device having a large size and high resolution, reduction of the width and an increase in length of the signal wire are required, which causes an increase of wire resistance. Accordingly, current or voltage supplied to the pixel region P is not uniform, and display quality is degraded.
Therefore, reducing wire resistance is needed, and to do this, a low-resistance metal material such as Cu, Ag, or the like can be used to form the metal wire in the display device.
Particularly, processing to pattern Cu is easier than that of patterning Ag. Also, specific resistance of Cu is about 30% or less of that of Al. For example, Cu has specific resistance of about 2.1 to about 2.3 μΩcm and Al has specific resistance of about 3.1 μΩcm. Also, Cu has a better tolerance to hillock than Al.
Accordingly, because the gate electrode 103 , the gate line, the source and drain electrodes 111 and 113 , and the data line 115 are formed using Cu of low resistance, even though the display device has a large size and high resolution, signal delay can be prevented. Thus, operational problems can be prevented due to voltage drop, or non-uniform current or voltage supplied to the pixel region P causing a degradation of display quality.
Further, assuming that wire resistance is the same as that of the related art, a width of the patterned wire can be much reduced, and aperture ratio can be increased.
To address this problem in the present disclosure, the TFT T may include a silicide layer 200 formed on the source and drain electrodes 111 and 113 .
Accordingly, even though the TFT T includes the oxide semiconductor layer 107 and the metal wires contains Cu, degradation of operational properties of the TFT T can be avoided and an etch stopper ( 9 of FIG. 1 ) can be eliminated. Accordingly, the production process can be simplified, and production efficiency can be improved.
Further, oxidation of the metal wire using Cu can be prevented, and thus, current leakage and reduction of reliability due to the current leakage can also be prevented.
Referring to FIG. 1 , a first passivation layer 117 may be formed on the entire surface of the substrate 101 having the TFT T, and may be made of an inorganic insulating material, for example, silicon oxide (SiO 2 ). A second passivation layer 119 may be formed on the first passivation layer 117 , and may be made of an organic insulating material, for example, photo acryl. The second passivation layer 119 may have a flat surface.
A common electrode 121 may be formed on the second passivation layer 119 corresponding to the entire display region. A part of the common electrode 121 corresponding to each switching region TrA may be removed, and thus, parasitic capacitance due to overlapping the common electrode 121 and the source and drain electrodes 111 and 113 can be reduced.
A third passivation layer 123 may be formed on the common electrode 121 . The first to third passivation layers 117 , 119 , and 123 may include drain contact holes 113 a , 113 b , and 113 c , respectively, exposing the drain electrode 113 .
A pixel electrode 125 may be formed on the third passivation layer 123 in each pixel region P and contact the drain electrode 113 through the drain contact holes 113 a , 113 b , and 113 c.
The pixel electrode 125 in each pixel region P may include a plurality of bar-shaped openings OP. According to this configuration of the pixel electrode 125 , the array substrate 100 may be used for a fringe field switching (FFS) mode LCD.
As described above, the array substrate 100 may include the TFT T using the oxide semiconductor layer 107 , and the metal wires using Cu of low resistance, and thus, the etch stopper of the related art can be eliminated, and degradation of the TFT T can be avoided.
Accordingly, production processes can be simplified and production efficiency can be improved.
Further, oxidation of the metal wire using Cu can be prevented, and reduction of reliability due to current leakage can also be prevented.
In this exemplary embodiment, instead of forming the related art etch stopper, a surface treatment on the back channel region of the oxide semiconductor layer 107 using oxygen may be performed before depositing the first passivation layer 117 . Accordingly, oxygen is supplemented at the surface of the back channel where oxygen was reduced by the prior art processes. Also, converting the surface of the oxide semiconductor layer 107 into an insulating material using an oxygen surplus can minimize current leakage at the back channel region. Accordingly, degradation of property of the TFT T can be prevented.
The surface treatment may be conducted using an oxygen (O 2 ) treatment, ozone (O 3 ) treatment, a thermal treatment under an oxygen atmosphere, or the like.
Cu used for the metal wires such as the source and drain electrodes 111 and 113 and the data line 115 is easily oxidized. Accordingly, it is difficult to conduct the surface treatment of the oxide semiconductor layer 107 .
Here, the silicide layer 200 functions to prevent the source and drain electrode 111 and 113 from being exposed to oxygen (O 2 ) or ozone (O 3 ) in the surface treatment for the oxide semiconductor layer 107 . Accordingly, current leakage due to the oxidation of the metal wire can be prevented, and reliability can be improved.
Further, the silicide layer 200 functions as a diffusion barrier layer for Cu used in the source and drain electrodes 111 and 113 .
In other words, Cu ions of the source and drain electrodes 111 and 113 diffuse to the first passivation layer 117 made of oxide silicon (SiO 2 ), and an insulation property of the first passivation layer 117 is reduced. However, in the embodiment, the silicide layer 200 is formed on the source and drain electrodes 111 and 113 , and the diffusion of the Cu ions can be prevented.
Also, oxidation can be prevented by the silicide layer 200 .
A method of fabricating the array substrate 100 for the LCD of the embodiment is explained as follows.
FIGS. 3A to 3I are cross-sectional views illustrating the array substrate for the LCD according to an embodiment of the present disclosure.
Referring to FIG. 3A , a gate electrode 103 , a gate line (not shown), a gate insulating layer 105 , an oxide semiconductor layer 107 , source and drain electrodes 111 and 113 , and a data line 115 may be formed on a transparent substrate 101 .
The gate electrode 103 , the gate insulating layer 105 , the oxide semiconductor layer 107 , and the source and drain electrodes 111 and 113 form a TFT Tr in a switching region TrA.
The gate electrode 103 , the gate line, the source and drain electrodes 111 and 113 , and the data line 115 may have a double-layered structure that includes a first layer of Mo, Ti, or MoTi, and a second layer, on the first layer, of Cu having low resistance.
The first layer functions to improve adhesion between the substrate 101 and the second layer of Cu.
The gate insulating layer 105 may be formed, for example, in a PECVD (plasma enhanced chemical vapor deposition) method, and be made of an inorganic insulating material, for example, silicon oxide (SiO 2 ) or silicon nitride (SiNx).
The oxide semiconductor layer 107 may be made of one of zinc oxide, tin oxide, Ga—In—Zn oxide, and In—Sn oxide, which each have amorphous structure, such the one doped with one of Al, Ni, Cu, Ta, Mo, Hf, and Ti using a sputtering method. The oxide semiconductor layer 107 may be patterned using a mask process so that the oxide semiconductor layer 107 having an island shape is formed corresponding to the gate electrode 103 .
Referring to FIG. 3B , a gas mixture containing silane (SiH 4 ) may be injected onto the source and drain electrodes 111 and 113 .
The gas mixture may be a mixture of silane (SiH 4 ) and nitrogen (N 2 ), or a mixture of silane (SiH 4 ), nitrogen (N 2 ), and one of helium (He) and argon (Ar).
When the gas mixture containing silane and nitrogen is injected onto the source and drain electrodes 111 and 113 , silicon of silane is diffused into Cu of the source and drain electrodes 111 and 113 so that a silicide layer 200 is formed at the surfaces of the source and drain electrodes 111 and 113 .
The silicide layer 200 functions to prevent the source and drain electrodes 111 and 113 using Cu from being oxidized during the surface treatment process for the oxide semiconductor layer 107 or when depositing a first passivation layer 117 made of silicon oxide (SiO 2 ).
Further, the silicide layer 200 functions to prevent Cu ions from being diffused to the first passivation layer 117 of silicon oxide (SiO 2 ).
By using the silicide layer 200 , an etch stopper can be eliminated without degradation of the TFT T, and thus, production processes can be simplified and production efficiency can be improved.
Further, because the oxidation of the metal wire using Cu can be prevented, current leakage in the TFT can be prevented.
Then, referring to FIG. 3C , a surface treatment may be conducted for a back channel region of the oxide semiconductor layer 107 exposed between the source and drain electrodes 111 and 113 . The surface treatment may be an oxygen plasma treatment, an ozone treatment, or a thermal treatment in an oxygen rich atmosphere.
For an example, the back channel region of the oxide semiconductor layer 107 may be surface-treated using the oxygen plasma treatment, and this treatment may be conducted under at a power of about 10 W to about 2000 W, and a oxygen flow rate of about 10 sccm to about 100 sccm.
In another example, the back channel region may be surface-treated using an ozone treatment through UV irradiation in an ozone atmosphere. In yet another example, the back channel region may be surface-treated using heat of about 100 degrees Celsius to about 300 degrees Celsius.
Through the surface treatment as described above, the problem that the oxide semiconductor layer 107 is reacted with hydrogen gas when depositing the first passivation layer 117 and changed into a conductor can be prevented.
Further, the problem that the semiconductor layer 107 is more susceptible to oxygen vacancy generation due to ionic bonds increasing electron density can be prevented. Further, the problem that when forming the source and drain electrodes 111 and 113 , oxygen concentration at the back channel region after dry-etching or wet-etching remarkably decreases, and thus the oxide semiconductor layer 107 changes into a conductor can be prevented.
Accordingly, deterioration of current leakage of the oxide semiconductor layer 107 can be prevented.
Particularly, even though the source and drain electrodes 111 and 113 use Cu of low resistance, since the silicide layer 200 is formed on the source and drain electrodes 111 and 113 , the source and drain electrodes 111 and 113 are not affected by the surface treatment of the oxide semiconductor layer 107 . Thus, oxidation of the source and drain electrodes 111 and 113 can be prevented.
Referring to FIG. 3D , the first passivation layer 117 may be formed on the substrate 101 having the surface-treated oxide semiconductor layer 107 by ionizing a gas mixture containing silane (SiH 4 ) and nitrous oxide (N 2 O) and depositing the ionized gas, using a PECVD. Then, referring to FIG. 3E , the first passivation layer 117 may be patterned in a mask process to form a first drain contact hole 113 a.
The process of forming the silicide layer 200 in FIG. 3B , the process of surface-treating the oxide semiconductor layer 107 in FIG. 3C , and the process of forming the passivation layer in FIGS. 3D and 3E may be performed continuously in the same chamber. In this case, in the process of forming the silicide layer 200 , the gas mixture containing silane is injected to grow the silicide layer 200 with the power of the chamber off.
In other words, the gas mixture containing silane is injected onto the source and drain electrodes 111 and 113 in a state that the gas mixture is not ionized.
Referring to FIG. 3F , an organic material, for example, photo acryl may be deposited on the first passivation layer 117 to form a second passivation layer 119 , and the second passivation layer 119 may be patterned using a mask process to form a second drain contact hole 113 b corresponding to the first drain contact hole 113 a and exposing the drain electrode 113 .
Alternatively, the first and second drain contact holes 113 a and 113 b , respectively, may be simultaneously formed in a method of forming the first and second passivation layers 117 and 119 , and then patterning the first and second passivation layers 117 and 119 . In other words, the first and second drain contact holes 113 a and 113 b can be formed in the same mask process.
Referring to FIG. 3G , a transparent conductive material, for example, indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) may be deposited on the second passivation layer 119 , and patterned using a mask process to form a common electrode 121 . The common electrode 121 may be formed on the entire display region, and have an opening corresponding to at least part of each switching region TrA.
Referring to FIG. 3H , an inorganic insulating material, for example, silicon oxide or silicon nitride may be deposited on the common electrode 121 to form a third passivation layer 123 . Then, the third passivation layer 123 may be patterned in a mask process to form a third drain contact hole 113 c , corresponding to the first and second drain contact holes 113 a and 113 b , and exposing the drain electrode 113 .
Referring to FIG. 3I , a transparent conductive material, for example, indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) may be deposited on the third passivation layer 123 , and patterned using a mask process to form a pixel electrode 125 in each pixel region P. The pixel electrode 125 may contact the drain electrode 113 through the first to third drain contact holes 113 a to 113 c , and includes a plurality of openings OP in each pixel region P.
Through the above-described processes, the array substrate 100 may be fabricated. This array substrate 100 may be used as an array substrate for a FFS mode LCD.
Alternatively, a pixel electrode having a plate shape may be formed in each pixel region on an array substrate, a common electrode may be formed on a substrate opposing to the array substrate, and the array substrate and the opposing substrate are attached to form a twisted nematic (TN) mode LCD, electronic controlled birefringence (ECB) mode LCD, or vertical alignment (VA) mode LCD.
Alternatively, a bar-shaped pixel electrode and a bar-shaped common electrode may be alternated in each pixel region at an array substrate, and this array substrate may be an array substrate used for an in plane switching (IPS) mode LCD.
Also, the array substrate of the embodiment can be applied as an array substrate for other flat display devices such as an OLED device.
As described above, in the array substrate 100 , the silicide layer 200 may be formed on the source and drain electrodes 111 and 113 , and the surface treatment may be performed for the back channel region of the oxide semiconductor layer 107 . Accordingly, even though the TFT T may include the oxide semiconductor layer 107 and the metal wires use Cu layer of low resistance, the etch stopper can be eliminated and degradation of the TFT T can be prevented.
FIGS. 4A and 4B are graphs illustrating transfer properties of TFTs including oxide semiconductor layers according to a comparative example and the embodiment of the present disclosure, respectively. FIGS. 4A and 4B each shows a relationship of drain current to gate voltage with a drain voltage kept at 0.1V and 10V.
In the comparative example, the etch stopper is eliminated from the related art array substrate through process simplification. Accordingly, referring to FIG. 4A , the voltage-to-current transfer curve shows that the comparative TFT does not have properties of a switching element, but is a conductor.
However, in the disclosed embodiment, the silicide layer 200 may be formed on the source and drain electrodes 111 and 113 , and the surface treatment may be conducted for the back channel region of the oxide semiconductor layer 107 . In this case, referring to FIG. 4B , the TFT T of the disclosed embodiment has properties of a switching element.
In other words, in the disclosed embodiment, since the silicide layer 200 may be formed on the source and drain electrodes 111 and 113 , and the surface treatment may be conducted for the back channel region of the oxide semiconductor layer 107 , production process can be simplified, and degradation of the TFT T can be prevented. Further, oxidation of the metal wires using Cu can be prevented, and thus, reduction of reliability due to current leakage can be prevented.
In other words, in case that the silicide layer 200 is not formed on the source and drain electrodes 111 and 113 , the source and drain electrodes 111 and 113 are oxidized by the surface treatment for the oxide semiconductor layer 107 . This is shown in FIG. 5A , illustrating an occurrence of oxidation of metal wires using Cu not having silicide layer thereon. When the oxidation occurs, a reduction of reliability is caused by leakage current.
However, in the disclosed embodiment, because of the silicide layer 200 , the oxidation of the source and drain electrodes 111 and 113 can be prevented. This is shown in FIG. 5B , illustrating no occurrence of oxidation of metal wires using Cu having the silicide layer thereon.
As described above, when the silicide layer 200 is formed on the source and drain electrodes 111 and 113 , the oxidation of the source and drain electrodes 111 and 113 using Cu can be prevented. Therefore, reduction of reliability due to current leakage can be prevented.
It will be apparent to those skilled in the art that various modifications and variations can be made in a display device of the present disclosure without departing from the sprit or scope of the disclosure. Thus, it is intended that the present disclosure covers the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. | An array substrate for an electronic display includes a substrate; a gate electrode on the substrate; a gate insulating layer on the gate electrode; an oxide semiconductor layer on the gate insulating layer; a source electrode and a drain electrode on the oxide semiconductor layer; a silicide layer on the source and drain electrodes; and a first passivation layer on the source electrode and the drain electrode. The array substrate and fabrication method thereof prevent degradation of a thin-film transistor (TFT) used in driving pixels of the electronic display. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for resolving stereoisomeric mixtures of thiols. In particular, the present invention relates to purely organocatalytic mediated resolution of enantiomeric mixtures of thiols without the need for enzymes. Also disclosed are some novel catalysts.
BACKGROUND TO THE INVENTION
[0002] Kinetic resolution (KR) is an established methodology for the preparation of enantioenriched compounds (see Scheme 1). In a chiral environment, for example in the presence of a chiral reagent B*, the enantiomers of a racemic mixture (A and A′) exhibit different reaction kinetics making it possible to modify one enantiomer (e.g. to provide A-B*) of the racemic mixture preferentially over the other. Thus, by preferentially modifying one of the enantiomers it is easy to separate it from the other enantiomer.
[0000]
[0003] KR represents one of the most convenient methods for the rapid isolation of enantiopure alcohols by resolving the corresponding racemic materials via enantioselective acylation as shown in Scheme 2.
[0000]
[0004] Initially, KR of racemic alcohols was carried out using biological catalysts such as enzymes. However, enzyme mediated catalysis can be troublesome on account of the low tolerance of enzymes to changes in pH and temperature. Furthermore, the incompatibility of enzymes with organic solvents vastly reduces the range of alcohol substrates that are suitable for acylation via enzyme mediated catalysis. Accordingly, in recent years several efficient and selective artificial organocatalysts for these processes have become available. As used herein organocatalysts are small molecule, non-metal containing catalysts that are soluble in organic solvents.
[0005] While the KR of alcohols is now a mature and useful technology, no analogous direct methods exist for the highly selective, direct catalytic KR of racemic thiols (i.e., R—SH)—despite the importance of thiols and organosulfur compounds in organic chemistry, and chemical biology.
[0006] Baker's yeast has been used to resolve a chiral thiol in the presence of glucose, however the resolved material was isolated in trace amounts only and with low enantioselectivity (40% ee). Reports disclosing lipase-catalysed transesterification of thioesters derived from racemic thiols are also acknowledged. Under optimal conditions the thiol products were obtained with high enantioselectivity (up to 95% ee). However, the latter is a multi-step methodology for the KR of thiols, only three thioester substrates were resolved, the methodology required long reaction times (up to 200 h) and high mass loadings of the enzyme catalyst.
[0007] International Patent Publication No. WO2009/050216 discloses a methodology for the dynamic kinetic resolution of thiols comprising utilising a hydrolase enzyme in the presence of an epimerisation catalyst. Notwithstanding these reports, enzymatic mediated resolution of thiols intrinsically suffers from the same problems as enzymatic resolution of alcohols discussed above.
[0008] While enantioenriched thiols can be synthesised from the corresponding alcohols, this simply makes one reliant on (and limited by) the availability of the desired alcohol substrate in enantiopure form. In addition, care must be exercised where a substrate (or its derivatives) is capable of racemisation.
[0009] For example, in attempting to prepare enantiopure thiols from the corresponding alcohols the present inventors found that subjecting commercially available (R)-1-phenyl-2-methyl-propanol (>99% ee) to a sequence involving mesylation, substitution with thioacetate ion (dry DMSO solvent, rt) and deprotection with LiAlH 4 afforded (S)-1-phenyl-2-methyl-propanethiol in a substantially diminished enantiomeric excess of 84.5%, despite considerable care taken to try to avoid conditions favouring a competing SN1 substitution pathway (see Scheme 3).
[0000]
[0010] The paucity of methodologies available for the catalytic asymmetric synthesis of enantioenriched thiols, and for the KR of thiols in particular, is attributable to the fact that, relative to alcohols, thiol substrates are inter alia ‘softer’ nucleophiles, exhibit greater atomic distance between the reacting heteroatom and the stereocentre and possess a lower heteroatom pKa.
[0011] Accordingly, it would be desirable to provide an organocatalytic enantioselective acylation protocol for the kinetic resolution of thiols, which mitigates the problems disclosed supra.
SUMMARY OF THE INVENTION
[0012] The present invention provides for a method for resolving stereoisomeric mixtures of thiols. In particular, the present invention provides for purely organocatalytic mediated resolution of enantiomeric mixtures of thiols without the need for enzymes. Advantageously, such a method would not suffer from incompatibilities with organic solvents, high/low temperatures, high/low pH, etc. as discussed above.
[0013] Accordingly, in a first aspect the present invention provides for a method of resolving a mixture of stereoisomers of a thiol comprising the step of preferentially acylating one thiol stereoisomer in the presence of a bifunctional organocatalyst.
[0014] A mixture of stereoisomers of a thiol may comprise either enantiomeric mixtures or diastereomeric mixtures of the thiol. The mixture of stereoisomers of a thiol may be a diastereomeric mixture of the thiol. There is no upper limit on the number of diastereomers in the mixture, for example there could be between four and ten diastereomers within the mixture. The mixture of stereoisomers of a thiol may be an enantiomeric mixture of the thiol, i.e. a mixture consisting of two enantiomers.
[0015] As used herein the term mixture does not limit to a two component mix or a specific ratio of two or more components. In particular it does not limit to a 50:50 mixture. Mixture ratios from 1:99 to 99:1 are covered by the term mixture. The term mixture also covers multi component mixtures, such as a mixture of 3 or more diastereomers in any given ratio.
[0016] Within this specification, the term bifunctional organocatalyst refers to a chiral, small organic molecule (i.e., non-metal based) having a Lewis acid moiety and a Lewis base moiety within the molecule, which is used in sub-stoichiometric loading relative to at least one of the reactants. The chiral, small organic molecule may comprise between 5 and 60 carbon atoms. The bifunctional organocatalyst may be used in substoichiometric loading relative to the stereoisomeric mixture of the thiol.
[0017] Suitably, the bifunctional organocatalyst or chiral small organic molecule is substantially enantiopure. This is important for efficient resolution (or separation) of the mixture of stereoisomers. The bifunctional organocatalyst may function by enhancing the nucleophilicity of a first reaction component and enhancing the electrophilicity of a second reaction component. For example, the bifunctional organocatalyst may enhance the electrophilicity of an acylating agent (such as an organic anhydride) and enhance the nucleophilicity of one enantiomer of an enantiomeric mixture of a thiol, thereby facilitating reaction of both components in a chiral environment.
[0000]
[0018] The thiols may be selected from the group consisting of primary thiols and secondary thiols. The thiol may be a thiol selected from the group consisting of C 1 -C 100 alkyl, C 3 -C 100 cycloalkyl, C 5 -C 100 aryl, C 5 -C 100 heteroaryl and combinations thereof. The thiol may be a secondary thiol. The secondary thiol may be selected from the group consisting of C 1 -C 100 alkyl, C 3 -C 100 cycloalkyl, C 5 -C 100 aryl, C 5 -C 100 heteroaryl and combinations thereof. The secondary thiol may be selected from the group consisting of C 1 -C 20 alkyl, C 5 -C 20 aryl and combinations thereof. The thiol may be optionally substituted one or more times with at least one of a halogen, C 1 -C 5 alkoxy, C 1 -C 5 thioalkoxy, and cyano.
[0019] As used herein, the term “C x -C y alkyl” embraces C x -C y unbranched alkyl, C x -C y branched alkyl and combinations thereof. The term (cyclo)alkyl does not preclude the presence of one or more C—C unsaturated bonds in the carbon (ring)/chain. The terms aryl and heteroaryl encompass fused aromatic and fused heteroaromatic rings respectively.
[0020] The method of the present invention may be carried out in a solvent selected from the group consisting of C 5 -C 12 hydrocarbons, C 6 -C 12 aromatic hydrocarbons, C 3 -C 12 ketones (cyclic and acyclic), C 2 -C 12 ethers (cyclic and acyclic), C 2 to C 12 esters (cyclic and acyclic), C 2 -C 5 nitriles and combinations thereof. Desirably, the solvent is ethereal. For example, C 2 -C 12 ethers (cyclic and acyclic). Suitable ethers may be selected from the group consisting of diethylether, THF, 2-methyl THF, diisopropylether, methyltertbutylether (MTBE) and combinations thereof. In a preferred embodiment, the solvent is methyltertbutylether (MTBE).
[0021] The catalyst loading with respect to the thiol may be 0.1-50 mol %, for example 0.1-25 mol %, such as 0.1-10 mol %. Desirably, the catalyst loading with respect to the thiol is 5-10 mol %. Advantageously, this represents a highly economic and efficient catalyst loading.
[0022] The bifunctional organocatalyst may comprise a cinchona alkaloid. As used herein a catalyst comprising a cinchona alkaloid refers to any catalyst comprising one of the following structural elements:
[0000]
[0023] Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof;
[0024] M can be H, OH, or OMe; and
[0025] R 1 is a moiety comprising a hydrogen bond donor.
[0026] The moiety comprising a hydrogen bond donor may comprise between 1 and 30 carbon atoms. The cinchona alkaloid may be substituted with a urea, thiourea or sulfonamide functional group. For example, R 1 may comprise a urea, thiourea or sulfonamide functional group. For example, R 1 may comprise a C 1 -C 20 urea, C 1 -C 20 thiourea or a C 1 -C 20 sulfonamide.
[0027] The bifunctional organocatalyst may be selected from the group consisting of:
[0000]
[0028] wherein X can be O or S;
Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 - 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof; M can be H, OH, or OMe; B can be C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, C 5 -C 15 aryl, C 5 -C 15 heteroaryl or combinations thereof, optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; R 1 and R 2 can be the same or different and may comprise C 1 -C 15 alkyl, or R 1 and R 2 may together define a C 3 -C 15 cycloalkyl ring (i.e., R 1 and R 2 may together with N define a C 3 -C 15 heterocyclic ring), wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; R 3 and R 4 can be the same or different and may comprise C 1 -C 15 alkyl, or R 3 and R 4 may together define a C 3 -C 15 cycloalkyl ring, a C 5 -C 15 aryl ring, or a C 5 -C 15 heteroaryl ring wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; and
R 5 and R 6 can be the same or different and may comprise C 1 -C 15 alkyl, or R 5 and R 6 may together define a C 3 -C 15 cycloalkyl ring, a C 5 -C 15 aryl ring, or a C 5 -C 15 heteroaryl ring wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof.
[0034] As used herein “Bn” is short hand for “benzyl”.
[0035] The bifunctional organocatalyst may be selected from the group consisting of:
[0000]
wherein Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof;
M can be H, OH, or OMe;
B can be C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, C 5 -C 15 aryl, C 5 -C 15 heteroaryl or combinations thereof, optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof;
R 1 and R 2 can be the same or different and may comprise C 1 -C 15 alkyl, or R 1 and R 2 may together define a C 3 -C 15 cycloalkyl ring (i.e., R 1 and R 2 may together with N define a C 3 -C 15 heterocyclic ring), wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; and
R 3 and R 4 can be the same or different and may comprise C 1 -C 15 alkyl, or R 3 and R 4 may together define a C 3 -C 15 cycloalkyl ring, a C 5 -C 15 aryl ring, or a C 5 -C 15 heteroaryl ring wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof.
[0041] B may be C 5 -C 15 aryl, or C 5 -C 15 heteroaryl optionally substituted one or more times with at least one of a halogen, C 1 -C 5 alkyl, or combinations thereof.
[0042] The bifunctional organocatalyst may be selected from the group comprising:
[0000]
Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof;
M can be H, OH, or OMe; and
B can be C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, C 5 -C 15 aryl, C 5 -C 15 heteroaryl or combinations thereof, optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof.
[0046] B may be C 5 -C 15 aryl, or C 5 -C 15 heteroaryl optionally substituted one or more times with at least one of a halogen, C 1 -C 5 alkyl, or combinations thereof.
[0047] According to the method of the present invention the step of acylating the thiol comprises reacting the thiol with an organic anhydride. The organic anhydride may be a cyclic anhydride. The organic anhydride (cyclic or acyclic) may be a C 4 -C 50 organic anhydride.
[0048] The organic anhydride may be selected from the group consisting of:
[0000]
[0049] wherein R 1 and R 2 are the same or different and are selected from the group consisting of C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl;
[0050] R 3 and R 4 are the same or different and are selected from the group consisting of H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl, such that at least one of R 3 and R 4 is H;
[0051] R 5 and R 6 are the same or different and are selected from the group consisting of H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl; and
[0052] n can be 0-5.
[0053] The organic anhydride may be of the general formula:
[0000]
and may be a prochiral anhydride, wherein R 3 and R 4 are the same or different and are selected from the group consisting of H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl, such that at least one of R 3 and R 4 is H; and
n is 1.
[0056] According to the method of the present invention acylation of the thiol with the prochiral anhydride in the presence of the bifunctional organocatalyst may proceed with desymmetrisation of the prochiral anhydride to afford a thioester. The thioester may be at least one of enantiomerically or diastereomerically enriched.
[0057] The organic anhydride may be of the general formula:
[0000]
and may be a meso anhydride, wherein R 5 and R 6 are the same and are selected from the group consisting of H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl.
[0059] According to the method of the present invention acylation of the thiol with the meso anhydride in the presence of the bifunctional organocatalyst may proceed with desymmetrisation of the meso anhydride to afford a thioester. The thioester may be at least one of enantiomerically or diastereomerically enriched.
[0060] In a further aspect, the present invention provides for use of the method of the present invention in the preparation of an enantioenriched thiol. The enantioenriched thiol may be a pharmaceutical. For example, the method of the present invention may be used in the preparation of enantioenriched 3-(aminomethyl)-5-methylhexanoic acid. The (R)-enantiomer of 3-(aminomethyl)-5-methylhexanoic acid is the blockbuster anti-convulsive drug Pregabalin marketed as ‘lyrica’®.
[0061] In yet a further aspect the present invention provides for a process for the preparation of enantioenriched 3-(aminomethyl)-5-methylhexanoic acid comprising the steps of:
preferentially acylating one thiol enantiomer of an enantiomeric mixture of the thiol with 3-isobutylglutaric anhydride in the presence of a bifunctional organocatalyst according to the method of the present invention; and converting the thioester functional group (formed in the previous step) into an amine.
[0064] The step of converting the thioester functional group into an amine may comprise:
i) aminolysis of the thioester functional group to yield an amide; and ii) subjecting the amide product of step i) to a Hofmann rearrangement.
[0067] Aminolysis of the thioester functional group may comprise treating the thioester with ammonia or an amine. Preferably, aminolysis of the thioester functional group comprises treating the thioester with ammonia to yield a primary amide. The Hofmann rearrangement is an eminent synthetic transformation which converts an amide to an amine with the loss of carbon monoxide. All protocols for effecting this transformation are embraced by the present invention.
[0068] The invention further provides for a compound having the general structure:
[0000]
Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof; and
[0070] M can be H, OH, or OMe.
[0071] The compound of the present invention may be used as an acylation catalyst in the resolution of a mixture of stereoisomers of a thiol. That is a molecule that catalyses preferential acylation of one thiol stereoisomer over another thiol stereoisomer. Desirably, the mixture of stereoisomers of a thiol is an enantiomeric mixture of the thiol.
[0072] In a further aspect the present invention provides for a method of desymmetrising at least one of a prochiral anhydride or a meso anhydride comprising the steps of:
(i) adding the prochiral anhydride or meso anhydride to a mixture of enantiomeric thiols; and (ii) adding a bifunctional organocatalyst to the mixture of the prochiral anhydride and the enantiomeric thiols.
[0075] The prochiral anhydride may be a C 6 -C 40 anhydride. The meso anhydride may be a C 6 -C 40 anhydride. The prochiral anhydride may be of the general formula:
[0000]
wherein R 3 and R 4 are the same or different and are selected from the group consisting of H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl, such that at least one of R 3 and R 4 is H; and
n is 1.
[0078] The meso anhydride may be of the general formula:
[0000]
wherein R 5 and R 6 are the same and are selected from the group consisting of H, C 1 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 5 -C 20 aryl, C 5 -C 20 heteroaryl and combinations thereof, optionally substituted with at least one of a halogen, cyano, or C 1 -C 5 fluoroalkyl.
[0080] The thiols may be selected from the group consisting of primary thiols and secondary thiols. The thiol may be a thiol selected from the group consisting of C 1 -C 100 alkyl including C 3 -C 100 cycloalkyl, C 5 -C 100 aryl including C 5 -C 100 heteroaryl and combinations thereof. The thiol may be a secondary thiol. The secondary thiol may be selected from the group consisting of C 1 -C 100 alkyl including C 3 -C 100 cycloalkyl, C 5 -C 100 aryl including C 5 -C 100 heteroaryl and combinations thereof. The secondary thiol may be selected from the group consisting of C 1 -C 20 alkyl, C 5 -C 20 aryl and combinations thereof. The thiol may be optionally substituted one or more times with at least one of a halogen, C 1 -C 5 alkoxy, C 1 -C 5 thioalkoxy, and cyano.
[0081] The bifunctional organocatalyst may comprise a cinchona alkaloid. For example, the catalyst may comprise one of the following structural elements:
[0000]
[0082] Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof;
[0083] M can be H, OH, or OMe; and
[0084] R 1 is a moiety comprising a hydrogen bond donor.
[0085] The moiety comprising a hydrogen bond donor may comprise between 1 and 30 carbon atoms. The cinchona alkaloid may be substituted with a urea, thiourea or sulfonamide functional group. For example, R 1 may comprise a urea, thiourea or sulfonamide functional group. For example, R 1 may comprise a C 1 -C 20 urea, C 1 -C 20 thiourea or a C 1 -C 20 sulfonamide.
[0086] The bifunctional organocatalyst may be selected from the group consisting of:
[0000]
[0087] wherein X can be O or S;
Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof; M can be H, OH, or OMe; B can be C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, C 5 -C 15 aryl, C 5 -C 15 heteroaryl or combinations thereof, optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; R 1 and R 2 can be the same or different and may comprise C 1 -C 15 alkyl, or R 1 and R 2 may together define a C 3 -C 15 cycloalkyl ring (i.e., R 1 and R 2 may together with N define a C 3 -C 15 heterocyclic ring), wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; R 3 and R 4 can be the same or different and may comprise C 1 -C 15 alkyl, or R 3 and R 4 may together define a C 3 -C 15 cycloalkyl ring, a C 5 -C 15 aryl ring, or a C 5 -C 15 heteroaryl ring wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; and R 5 and R 6 can be the same or different and may comprise C 1 -C 15 alkyl, or R 5 and R 6 may together define a C 3 -C 15 cycloalkyl ring, a C 5 -C 15 aryl ring, or a C 5 -C 15 heteroaryl ring wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof.
[0094] The bifunctional organocatalyst may be selected from the group consisting of:
[0000]
Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof;
M can be H, OH, or OMe;
B can be C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, C 5 -C 15 aryl, C 5 -C 15 heteroaryl or combinations thereof, optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof;
R 1 and R 2 can be the same or different and may comprise C 1 -C 15 alkyl, or R 1 and R 2 may together define a C 3 -C 15 cycloalkyl ring (i.e., R 1 and R 2 may together with N define a C 3 -C 15 heterocyclic ring), wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof; and
R 3 and R 4 can be the same or different and may comprise C 1 -C 15 alkyl, or R 3 and R 4 may together define a C 3 -C 15 cycloalkyl ring, a C 5 -C 15 aryl ring, or a C 5 -C 15 heteroaryl ring wherein each may be optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof.
[0100] B may be C 5 -C 15 aryl, or C 5 -C 15 heteroaryl optionally substituted one or more times with at least one of a halogen, C 1 -C 5 alkyl, or combinations thereof.
[0101] The bifunctional organocatalyst may be selected from the group comprising:
[0000]
Z can be a C 1 to C 5 carbon chain optionally comprising at least one C—C unsaturated bond, and optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide and combinations thereof;
M can be H, OH, or OMe; and
B can be C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, C 5 -C 15 aryl, C 5 -C 15 heteroaryl or combinations thereof, optionally substituted one or more times with at least one of a halogen, cyano, CF 3 , NO 2 , C 1 -C 5 ketone, C 1 -C 5 ester, C 1 -C 10 amide, C 1 -C 5 sulfone, C 1 -C 5 sulfoxide, C 1 -C 5 alkyl and combinations thereof.
[0105] B may be C 5 -C 15 aryl, or C 5 -C 15 heteroaryl optionally substituted one or more times with at least one of a halogen, C 1 -C 5 alkyl, or combinations thereof.
[0106] The method of the present invention may be carried out in a solvent selected from the group consisting of C 5 -C 12 hydrocarbons, C 6 -C 12 aromatic hydrocarbons, C 3 -C 12 ketones (cyclic and acyclic), C 2 -C 12 ethers (cyclic and acyclic), C 2 to C 12 esters (cyclic and acyclic), C 2 -C 5 nitriles and combinations thereof. Desirably, the solvent is ethereal. For example, C 2 -C 12 ethers (cyclic and acyclic). Suitable ethers may be selected from the group consisting of diethylether, THF, 2-methyl THF, diisopropylether, methyltertbutylether (MTBE) and combinations thereof. In a preferred embodiment, the solvent is methyltertbutylether (MTBE).
[0107] The catalyst loading with respect to the thiol may be 0.1-50 mol %, for example 0.1-25 mol %, such as 0.1-10 mol %. Desirably, the catalyst loading with respect to the thiol is 5-10 mol %. This represents a highly economic and efficient catalyst loading.
[0108] The compounds resolved by the present invention may be found or isolated in the form of esters, salts, hydrates or solvates - all of which are embraced by the present invention.
[0109] Where suitable, it will be appreciated that all optional and/or preferred features of one embodiment of the invention may be combined with optional and/or preferred features of another/other embodiment(s) of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0110] Additional features and advantages of the present invention are described in, and will be apparent from, the detailed description of the invention and from the drawings in which:
[0111] FIG. 1 illustrates Kinetic Resolution of a thiol with simultaneous enantioselective synthesis of a (R)-Pregabalin precursor.
DETAILED DESCRIPTION OF THE INVENTION
[0112] It should be readily apparent to one of ordinary skill in the art that the examples disclosed herein below represent generalised examples only, and that other arrangements and methods capable of reproducing the invention are possible and are embraced by the present invention.
[0113] Preliminary experiments related to the acylative KR of the racemic sec-thiol 1 with glutaric anhydride (2a) in the presence of bifunctional (thio)urea-derived organocatalysts 10-12 and sulphonamide 13 (Table 1). Initial results were far from encouraging—acylation proceeded smoothly at low catalyst loading (5 mol %), but resulted in products of low enantiomeric excess (entries 1-4). Of the four catalysts tested sulphonamide 13 proved superior to the (thio)urea-derivatives and could promote the KR with a very modest selectivity (k fast /k slow ) of 1.5 (13% ee at 50% conv., entry 4). Further experimentation identified methyl tert-butylether (MTBE) as the optimal solvent overall, although the KR of 1 was slower but more selective in THF (entries 4-7).
[0114] These results represented the first examples of direct catalytic asymmetric KR of a thiol. Subsequently, KR reactions using 3-substituted achiral anhydride electrophiles 3a-5 were tried. This complicated matters considerably, as now control over the formation of 4 possible thioester diastereomers is required. In addition, it allowed for the possibility of a conceptually novel type of catalytic process where both kinetic resolution and anhydride desymmetrisation occur simultaneously. Gratifyingly, this proved to be the case—use of anhydrides 3a-5 resulted in more enantioselective acylations (entries 8-11), with methyl glutaric anhydride (3a) proving optimal. Using this electrophile the resolved thiol could be isolated in 33% ee at 50% conversion (using either 1 or 5 mol % of catalyst 13), corresponding to S=2.7.
[0115] Product esters 7a and 7b were both formed with excellent enantioselectivity (>90% ee) and with encouraging diastereocontrol (67:33 dr, entry 8). With respect to the anhydride, the desymmetrisation aspect of the reaction was highly selective—the parameter ee desymm (Table 1) represents the percentage excess of products derived from attack of the thiol 1 at one prochiral anhydride carbonyl moiety over the other (i.e. the enantiomeric excess of the desymmetrised product if the combined thioester diastereomers were substituted by an achiral (non-hydroxide) nucleophile without racemisation). It is also noteworthy that in the presence of triethylamine as an achiral catalyst the diastereoselectivity is reversed, with 19 as the major diastereomer.
[0116] Next the steric and electronic characteristics of the catalyst were systematically varied through the synthesis and evaluation of sulfonamides 14-17. While the electron deficient pentafluorophenyl-substituted catalyst fared a little better than 13, less acidic analogues 15-17 respectively possessed enhanced selectivity profiles (entries 12-15). Given the superiority of the hindered promoter 16, it was decided to accentuate the steric bulk of the sulfonamide further via the synthesis of the novel catalyst 18, which proved almost as active as 13 yet promoted the acylation with a synthetically useful KR selectivity of 8.5 (entry 16). Further optimisation of the reaction conditions (entries 17-19) resulted in the KR of thiol 1 with outstanding selectivity (S=25.5)—allowing the isolation of resolved (R)-1 in 90% ee at 54% conversion, along with ester 7a (formed as the major diastereomer, 89:11 dr) in 98% ee, with an excellent attendant ee desymm , of 96% (entry 19).
[0000]
TABLE 1
Kinetic resolution of thiol 1 with simultaneous desymmetrisation of achiral-anhydrides 3-5
anhydride
catalyst
T
conv.
ee esterA
ee esterB
ee desym
ee thiol
entry
(equiv.)
(mol %)
solvent
(° C.)
(%) c
dr d
(%) e
(%) e
(%) e,f
(%) e
S g
1
2a (0.5)
10 (5)
MTBE
rt
49
—
6.5
—
—
7
1.2
2
2a (0.5)
11 (5)
MTBE
rt
50
—
9
—
—
9
1.3
3
2a (0.5)
12 (5)
MTBE
rt
50
—
6
—
—
6
1.2
4
2a (0.5)
13 (5)
MTBE
rt
50
—
13
—
—
13
1.5
5
2a (0.5)
13 (5)
Et 2 O
rt
50
—
14
—
—
14
1.5
6
2a (0.5)
13 (5)
THF
rt
39
—
27
—
—
17
2.1
7
2a (0.5)
13 (5)
CH 2 Cl 2
rt
16
—
n.d.
—
—
—
—
8
3a (0.5)
13 (5)
MTBE
rt
50
66.5:33.5
95
91
92
33
2.7
9
3a (0.5)
13 (1)
MTBE
rt
49
67:33
97
88
94
33
2.7
10
4 (0.5)
13 (5)
MTBE
rt
50
n.d.
n.d.
n.d.
n.d.
21
1.8
11
5 (0.5)
13 (5)
MTBE
rt
50
60:40
n.d.
n.d.
n.d.
26
2.3
12
3a (0.5)
14 (5)
MTBE
rt
49
70:30
97
87
94
41
3.9
13
3a (0.5)
15 (5)
MTBE
rt
47
73:27
97
93
96
41
4.0
14
3a (0.5)
16 (5)
MTBE
rt
44
79:21
97
90
96
45
5.6
15
3a (0.5)
17 (5)
MTBE
rt
48
75:25
95
84
92
44
4.3
16
3a (0.5)
18 (5)
MTBE
rt
48
89:11
95
68
90
60
8.5
17a
3a (0.5)
18 (5)
MTBE
0
43
89:11
98
78
96
58
13.6
18a
3a (0.75)
18 (10)
MTBE
0
62
79:21
95
90
94
93
11.6
19b
3a (0.75)
18 (10)
MTBE
−30
54
89:11
98
84
96
90
25.5
20b
2b (0.75)
18 (10)
MTBE
−30
33
—
n.d.
—
—
42 (85) h
17.9
21b
3b (0.75)
18 (10)
MTBE
−30
4
—
n.d.
—
—
n.d.
n.d.
22b
2a (0.75)
18 (10)
MTBE
−30
50
—
n.d.
—
—
68 (68) h
10.7
a 48 h.
b 72 h.
c Conversion was determined using CSP-HPLC, where conversion = 100 × ee thiol /(ee thiol + ee thioester ); the value of ee thioester was calculated using all four thioester stereoisomers.
d Diastereomeric ratio = (6-9a + ent-6-9a):(6-9b + ent-6-9b).
e Determined by CSP-HPLC, see supporting information.
f Desymmetrisation efficiency: the enantiomeric excess of the desymmetrised product if the combined thioester products were substituted by an achiral (non-hydroxide) nucleophile, calculated as 100 × [(6-9a + 6-9b) − (ent-6-9a + ent-6-9b)]/[(6-9a + 6-9b) + (ent-6-9a + ent-6-9b)].
g S = enantioselectivity (k fast/slow ,).
h Value in parenthesis refers to the ee of the thiol obtained after deprotection via cleavage of the combined thioester products.
[0117] Thus, under optimum conditions 18 is capable of mediating the highly efficient and selective KR of a substrate class previously outside the orbit of direct enantioselective catalytic acylation, with the simultaneous desymmetrisation of a synthetically useful class of inexpensive achiral anhydride acylating agent—also with excellent enantioselectivity. To demonstrate that the desymmetrisation and kinetic resolution processes are synergistic, we next carried out the process under optimum conditions using the non-prochiral anhydrides 2a, 2b and 3b (entries 20-22). Kinetic resolution was either too slow or proceeded with lower enantioselectivity using these electrophiles.
[0118] Attention now turned to the question of substrate scope (Table 2). It was found that variation of the steric bulk of both the aromatic and aliphatic substituent is well tolerated by the catalyst—for example, α-Me, -Et, — i Pr and t Bu derivatives of benzyl mercaptan (i.e. 1 and 20-22, entries 1-4) could be resolved with excellent selectivity (up to S>50), resulting in the isolation of the unreacted thiol with >90% ee at ca. 50% conversion. A strong correlation between increasing aliphatic substituent bulk and selectivity was observed; however it is noteworthy that even the challenging substrate 20 (where the steric discrepancy between the two carbon-based substituents is smallest) could be resolved with synthetically useful selectivity. Variation of the characteristics of the aromatic substituent produced interesting results—substitution in the para-position either slightly reduces or has no impact on enantioselectivity (23-25, entries 5-7), while steric bulk at the ortho-position dramatically improved the KR; in optimum cases this resulted in levels of enantiodiscrimination (S>>100) more usually associated with the enzymatic KR of alcohols (26-28, entries 8-12).
[0000] Synthesis of Pregabalin [(R)-3-(aminomethyl)-5-methylhexanoic acid]
[0119] To demonstrate the potential utility of this methodology, the KR of thiol 28 (0.80 mmol) was carried out with catalyst 18 in the presence of achiral anhydride 4, which furnished (R)-28 (0.39 mmol, 99% ee) and the ring-opened product 29 (0.40 mmol) with excellent efficiency at 51% conversion as shown in FIG. 1 . Thioester 29 (as a mixture of diastereomers) was then treated with aqueous ammonia, resulting in its cleavage to afford the other thiol enantiomer (S)-28 (96% ee, 0.35 mmol) and the aminolysed product (S)-30 (97% ee, 0.38 mmol), again with high efficiency. Hemiamide (S)-30 is a precursor which can be converted in a single step to the (R)-antipode of the anticonvulsive agent Pregabalin and thus this sequence—in addition to serving as a highly efficient KR of 28—constitutes a rapid and convenient formal synthesis of the ‘blockbuster’ drug (marketed as ‘Lyrica’®).
[0000]
TABLE 2
Evaluation of substrate scope
time
cony.
ee thiol
abs.
entry
substrate
X
(h)
(%) a
(%) b
S c
config. d
1
20
0.75
68
63
97
14.5
(R)
2
21
0.75
74
56
91
19.0
(R)
3 e
1
0.75
68
54
90
25.5
(R)
4 f
22
0.75
96
52
94
51.5
(R)
5
23
0.75
72
65
95
10.7
(R)
6
24
0.90
120
56
87
15.0
(R)
7 8 g
25
0.75 0.75
74 72
58 45
82 59
9.7 11.8
(R) (R)
9 h
26
0.75
96
51
90
36.6
(R)
10
27
0.75
48
50
95 (94) j
126.0
(R)
11 i 12 k
28
0.75 0.75
48 48
50 43
98 (96) j 75 (98) j
265.0 275.0
(R) (R)
aRefers to conversion, determined using CSP-HPLC, where conversion = 100 × ee thiol /(ee thiol + ee thioester ).
b Determined by CSP-HPLC, see supporting information.
c S = enantioselectivity (k fast/slow , see ref. 1).
d Refers to the absolute configuration of the recovered thiol product (see supporting information).
e Data from Table 1.
f A repeat of this experiment (conv. 52%, S = 50.4) resulted in the isolation of the unreacted (R)-thiol in 47% yield and 95% ee after chromatography. After aminolysis of the combined thioester products the (S)-thiol was obtained in 43% isolated yield and 86% ee.
g Reaction at −40 °C.
h A repeat of this experiment in which the combined thioester diastereomers were aminolysed resulted in the isolation of the corresponding hemiamide in 93% ee.
i A repeat of this experiment (conv. 51%, S = 249.0) resulted in the isolation of the unreacted (R)-thiol in 48% yield and 99.6% ee after chromatography. After aminolysis of the combined thioester products the (S)-thiol was obtained in 44% isolated yield and 95% ee.
j Value in parenthesis refers to the ee of the thiol obtained after deprotection via cleavage of the combined thioester products.
k Reaction at −45 °C.
Conclusions
[0120] Disclosed herein is novel sulfonamide catalyst 18, which promotes the highly enantioselective (S>10) direct acylative KR of a sec-thiols for the first time, allowing their isolation in >90% ee at ca. 50% conversion. Under optimum conditions at low catalyst loadings the selectivity (k fast /k slow ) of these processes is in the range of 50-275, thus using the artificial catalyst 18 it is possible to achieve levels of enantiodiscrimination more usually associated with acylative KR by biological catalysts, using a substrate class not hitherto demonstrated to be generally amenable to enzyme-mediated direct acylative KR. In addition, the thiol-KR is accompanied by a synergistic, simultaneous desymmetrisation of an achiral anhydride electrophile—which occurs with excellent levels of enantioselectivity on a par with those associated with the best anhydride desymmetrisation methodologies in the literature. This catalytic desymmetrisation of an electrophile while it kinetically resolves a nucleophile is, to the best of our knowledge, a hitherto unreported phenomenon which possesses excellent potential as a tool to considerably improve upon both the synthetic utility and atom economy of acylative KR processes.
Experimental General
[0121] Proton Nuclear Magnetic Resonance spectra were recorded on a 400 MHz spectrometer in CDCl 3 (to prevent oxidation of the thiols, CDCl 3 was purified by distillation and stored under argon over molecular sieves) or DMSO-d 6 and referenced relative to residual CHCl 3 (δ=7.26 ppm) or DMSO (δ=2.54 ppm). Chemical shifts are reported in ppm and coupling constants in Hertz. Carbon NMR spectra were recorded on the same instrument (100 MHz) with total proton decoupling. All melting points are uncorrected. Flash chromatography was carried out using silica gel, particle size 0.04-0.063 mm. TLC analysis was performed on precoated 60F 254 slides, and visualised by UV irradiation and KMnO 4 staining. Optical rotation measurements are quoted in units of 10 −1 deg cm 2 g −1 . Toluene and methylene chloride were distilled over calcium hydride and stored under argon. Tetrahydrofuran and diethyl ether were distilled over sodium-benzophenone ketyl radical and stored under argon. Commercially available anhydrous t-butyl methyl ether was used. All reactions were carried out under a protective argon atmosphere. Analytical CSP-HPLC was performed on a Daicel CHIRALPAK AS, AD, or Chiralcel OD-H (4.6 mm×25 cm) columns. The absolute configuration of each enantioenriched thiol was determined after derivatisation with (R)-2-methoxy-2-phenylacetic acid and analysis of the corresponding thioester by 1 H NMR spectroscopy as recently reported in the literature. In the cases of thiols 20 and 25, the absolute configuration (and fidelity of the literature 1 H NMR spectroscopic method) could be also confirmed by comparison of the optical rotation with the literature data.
Synthesis of Secondary Thiols
[0122] All secondary thiols were obtained from the corresponding thioester by reaction with LiAlH 4 in anhydrous THF. Thioesters 20, 21, 23, 24 and 27 were made from the corresponding alcohols via a modification of the Mitsunobu protocol. Thioesters 1, 22, 25, 26 and 28 were obtained from the corresponding alcohols via a two step procedure involving initial activation of the hydroxyl function by conversion to the corresponding mesylate (1, 25, 26 and 28) or bromide (22) followed by displacement with the potassium salt of thioacetic acid in acetone or DMF.
General Procedure for the Preparation of Thioesters via the Mitsunobu Protocol
[0123]
[0124] Diisopropyl azodicarboxylate (DEAD) (2.95 mL, 15.0 mmol) was added dropwise and via syringe to an ice-cooled solution of triphenylphosphine (3.93 g, 15.0 mmol) in dry THF (30 mL) under argon. After 1 h, a solution of the appropriate alcohol (7.50 mmol) and thioacetic acid (1.07 mL, 15.0 mmol) in THF (10 mL) was slowly injected and the mixture was stirred continuously while warming to room temperature. After 12 h, the solvent was evaporated in vacuo and the resulting yellow slurry was suspended in n-hexane (40 mL) and stirred for 2 h. After removal of the precipitate that had formed by filtration, the filtrate was concentrated in vacuo and the desired product obtained as colourless oil after purification by flash chromatography on silica gel.
[0000] 1-Phenylethyl thioacetate
[0125] Following the general procedure outlined above, the product was isolated in 75% yield as a colourless oil.
[0126] TLC (Hexane:AcOEt, 96:4 v/v): R f =0.40. 1 H NMR (400 MHz, CDCl 3 ): δ7.40-7.23; (m, 5H), 4.77; (q, J=7.0 Hz, 1H), 2.33; (s, 3H), 1.68; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ194.6; (q), 142.1; (q), 128.1, 126.9, 126.7, 42.5, 30.0, 21.7.
[0000] Thioacetic acid S-[1-(4-methoxy-phenyl)-ethyl] ester
[0127] Following the general procedure outlined above, the product was isolated in 58% yield as a colourless oil.
[0128] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.30. 1 H NMR (400 MHz, CDCl 3 ): δ7.28; (d, J=8.5 Hz, 2H), 6.87; (d, J=8.5 Hz, 2H), 4.74; (q, J=7.0 Hz, 1H), 3.82; (s, 3H), 2.32; (s, 3H), 1.67; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ195.3; (q), 158.7; (q), 134.6; (q), 128.3, 113.9, 55.3, 42.5, 30.5, 22.3. HRMS (m/z): [M+H] + calcd. for C 11 H 15 O 2 S, 211.0793; found, 211.0797.
[0000] Thioacetic acid S-[1-(4-chloro-phenyl)-ethyl] ester
[0129] Following the general procedure outlined above, the product was isolated in 90% yield as a colourless oil.
[0130] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.37. 1 H NMR (400 MHz, CDCl 3 ): δ7.30; (m, 4H), 4.73; (q, J=7.3; Hz, 1H), 2.32; (s, 3H), 1.65; (d, J=7.3 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ194.4; (q), 140.9; (q), 132.5; (q), 128.2, 128.1, 41.8, 30.0, 21.5. HRMS (m/z): [M+H] + calcd. for C 10 H 12 OSCl, 215.0297; found, 215.0301.
[0000] Thioacetic acid S-(1-o-tolyl-ethyl) ester
[0131] Following the general procedure outlined above, the product was isolated in 76% yield as a colourless oil.
[0132] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.34. 1 H NMR (400 MHz, CDCl 3 ): δ7.34; (d, J=7.0 Hz, 1H), 7.25-7.15; (m, 3H), 4.95; (q, J=7.0 Hz, 1H), 2.41; (s, 3H), 2.34; (s, 3H), 1.68; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ195.0; (q), 139.4; (q), 135.1; (q), 130.1, 126.8, 126.2, 125.8, 38.9, 29.9, 21.6, 18.8. HRMS (m/z): [M+Na] + calcd. for C 11 H 14 ONaS, 217.0663; found, 217.0668.
[0000] Thioacetic acid S-(1-phenyl-propyl) ester
[0133] Following the general procedure outlined above, the product was isolated in 73% yield as a colourless oil.
[0134] TLC (Hexane:CH 2 Cl 2 , 1:1 v/v): R f =0.51. 1 H NMR (400 MHz, CDCl 3 ): δ7.38-7.23; (m, 5H), 4.51; (t, J=7.5 Hz, 1H), 2.32; (s, 3H), 2.04-1.92; (m, 2H), 0.93; (t, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ194.5; (q), 141.3; (q), 128.1, 127.2, 126.8, 49.2, 30.1, 28.9, 11.7. HRMS (m/z): [M+Na] + calcd. for C 11 H 14 ONaS, 217.0663; found, 217.0665.
General Procedure for the Preparation of Thioesters via the Mesylate Intermediate
[0135]
[0136] Triethylamine (TEA) (1.25 mL, 9.00 mmol) was added via syringe to a solution of the appropriate alcohol (7.50 mmol) in dry CH 2 Cl 2 (30 mL) under an argon atmosphere. The mixture was cooled to 0° C. and methanesulfonyl chloride (640 μL, 8.25 mmol) was added dropwise. The reaction was stirred continuously while it warmed to room temperature. After 12 h, the mixture was poured into an aqueous solution of HCl (1 N, 30 mL), the resulting mixture was then transferred to a separating funnel and the organic and aqueous layers were separated. The aqueous layer was extracted with CH 2 Cl 2 (2×30 mL) and the combined organic layers were washed with HCl (1 N) (30 mL) and a saturated aqueous solution of NaHCO 3 (30 mL). The organic phase was then dried over magnesium sulphate, filtered and evaporated to afford the desired intermediate as a colourless oil. This was immediately dissolved in dry acetone (10 mL) and potassium thioacetate (1.71 g, 15.0 mmol) was added. The reaction was then heated to reflux until none of the mesylate intermediate could be detected by 1 H-NMR spectroscopic analysis (12-28 h). The mixture was then filtered, the filtrate evaporated and the crude purified by flash-chromatography.
[0000] Thioacetic acid (2-methyl-1-phenyl-propyl) ester
[0137] Following the general procedure outlined above, the product was isolated in 74% yield as a colourless oil.
[0138] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.42. NMR (400 MHz, CDCl 3 ): δ7.22-7.35; (m, 5H), 4.44; (d, J=8.0 Hz, 1H), 2.32; (s, 3H), 2.08-2.22; (m, 1H), 1.06; (d, J=6.5 Hz, 3H), 0.89; (d, J=6.5 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ194.2; (q), 141.2; (q), 127.8, 127.7, 126.5, 54.8, 33.1, 30.2, 20.3, 20.1. HRMS (m/z): [M+Na] + calcd. for C 12 H 16 ONaS, 231.0820; found, 231.0819.
[0000] Thioacetic acid S-(1-naphthalen-1-yl-ethyl) ester
[0139] Following the general procedure, the product was isolated in 69% yield as a colourless oil.
[0140] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.34. 1 H NMR (400 MHz, CDCl 3 ): δ8.09; (d, J=8.5 Hz, 1H), 7.89; (d, J=8.0 Hz, 1H), 7.81; (d, J=8.5 Hz, 1H), 7.61-7.43; (m, 4H), 5.56; (q, J=7.0 Hz, 1H), 2.37; (s, 3H), 1.87; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ195.1; (q), 136.8; (q), 133.5; (q), 130.1; (q), 128.5, 127.8, 125.9, 125.4, 124.8, 124.1, 122.7, 38.2, 29.9, 21.8. HRMS (m/z): [M+Na] + calcd. for C 14 H 14 ONaS, 253.0663; found, 253.0659.
[0000] Thioacetic acid S-(1-naphthalen-2-yl-ethyl) ester
[0141] Following the general procedure outlined above, the product was isolated in 62% yield as a colourless oil.
[0142] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.31. 1 H NMR (400 MHz, CDCl 3 ): δ7.88-7.80; (m, 4H), 7.54-7.44; (m, 3H), 4.95; (q, J=7.0 Hz, 1H), 2.34; (s, 3H), 1.78; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ194.6; (q), 139.4; (q), 132.8; (q), 132.2; (q), 128.0, 127.4, 127.1, 125.8, 125.5, 125.2, 125.1, 42.6, 30.0, 21.6. HRMS (m/z): [M+H] + calcd. for C 14 H 15 ONS, 231.0844; found, 231.0848.
[0000] Thioacetic acid 1-(2,4,6-trimethyl-phenyl)-ethyl ester
[0143] Following the general procedure outlined above, the product was isolated in 62% yield as a colourless oil.
[0144] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.40. 1 H NMR (400 MHz, CDCl 3 ): δ6.85; (s, 2H), 5.35; (q, J=7.5 Hz, 1H), 2.44; (s, 6H), 2.33; (s, 3H), 2.26; (s, 3H), 1.67; (d, J=7.5 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): 195.0; (q), 136.3; (q), 136.1; (q), 135.4; (q), 135.2; (q), 130.3, 128.7, 37.4, 29.9, 21.0, 20.7, 20.5, 20.3 Note: this compound exhibits NMR spectra consistent with restricted rotation which is fast on the 1 H NMR spectroscopic time scale but slow on the 13 C NMR spectroscopic time scale. HRMS (m/z): [M+Na] + calcd. for C 13 H 18 ONaS, 245.0976; found, 245.0974.
[0000] Thioacetic acid S-(2,2-dimethyl-1-phenyl-propyl) ester
[0145] (1-Bromo-2,2-dimethyl-propyl)-benzene (1.00 g, 4.40 mmol) was dissolved in dry DMF (5 mL) under an argon atmosphere. Potassium thioacetate (2.51 g, 22.0 mmol) was added and the reaction was heated to 50° C. for 7 days. The solution was then concentrated and the product purified by column chromatography to obtain the desired thioester (970 mg, 99%).
[0146] TLC (Hexane:CH 2 Cl 2 , 7:3 v/v): R f =0.40. 1 H NMR (400 MHz, CDCl 3 ): δ7.33-7.22; (m, 5H), 4.52; (s, 1H), 2.32; (s, 3H), 1.00; (s, 9H). 13 C NMR (100 MHz, CDCl 3 ): δ193.9; (q), 140.4; (q), 129.0, 127.2, 126.4, 58.7, 34.9; (q), 30.2, 27.6. HRMS (m/z): [M+Na] + calcd. for C 13 H 18 ONaS, 245.0976; found, 245.0972.
General Procedure for the Reduction of Thioesters to Thiols
[0147]
[0148] A 100 mL three neck round-bottomed flask, flame dried and equipped with a reflux condenser, was charged with dry THF (15 mL) and LiAlH 4 (114 mg, 3.0 mmol). The suspension was cooled to 0° C. and a solution of the appropriate thioester (3.0 mmol) in dry THF (5 mL) was added in a dropwise manner. After 1 h refluxing, the reaction mixture was cooled to 0° C. and carefully quenched with aqueous HCl (1 M) (10 mL). The organic layer was separated and the aqueous solution extracted with Et 2 O (2×15 mL). The combined organic layers were then dried over magnesium sulphate, filtered and evaporated and the desired product obtained in excellent yield after purification by flash-chromatography on silica gel.
[0000] Synthesis of Catalyst 18—2,4,6-Triisopropyl-N-[(6-methoxy-quinolinyl)-(5-vinyl-1-azabicyclo[2.2.2.]octyl)-methyl]benzenesulfonamide
[0000]
[0149] To a suspension of 9-epi-QA.3HCl (1.0 g, 2.31 mmol) in dry CH 2 Cl 2 (20 mL), triethylamine (1.5 mL, 10.4 mmol) was then added via syringe and the resulting clear solution was cooled to 0° C. A solution of 2,4,6-Triisopropyl-phenyl sulphonyl chloride (700 mg, 2.31 mmol) in CH 2 Cl 2 (5 mL) was then slowly injected and the mixture was allowed to warm to room temperature and stirred for 15 h. After evaporation of the solvent, the crude residue was purified by flash chromatography affording the desired sulphonamide catalyst 18 (1.10 g, 81%). M.p. 115-118° C.; TLC (Hexane:EtOAc, 1:1 v/v): R f =0.48. [α] 20 589 =−43.0 (c=0.50, CHCl 3 ). 1 H NMR (400 MHz, DMSO-d 6 only the major rotamer quoted): δ8.52; (d, 1H, J=4.4 Hz), 7.92; (d, 1H, J=9.7 Hz), 7.47-7.41; (m, 2H), 7.40; (d, 1H, J=4.4 Hz), 6.99; (s, 2H), 5.73-5.70; (m, 1H), 5.16; (d, 1H, J=10.4 Hz), 4.96; (d, 1H, J=17.3 Hz), 4.89; (d, 1H, J=10.6 Hz), 3.96; (s, 3H, OCH 3 ), 3.83-3.94; (m, 3H), 3.07-3.09; (m, 1H), 2.81-2.93; (m, 3H), 2.63-2.68; (m, 1H), 2.46-2.48; (m, 1H), 2.21; (bs, 1H), 1.42-1.58; (m, 3H), 1.13-1.16; (m, 12H), 0.87; (d, 6H, J=6.5 Hz), 0.71-0.78; (m, 1H). 13 C NMR (100 MHz, DMSO-d 6 ): δ157.7, 152.1, 149.2, 147.8, 144.8, 144.1, 142.2, 134.6, 131.9, 127.9, 123.3, 121.2, 120.8, 114.7, 102.2, 60.7, 56.0, 55.3, 52.3, 40.3, 39.3, 33.7, 29.6, 27.8, 27.4, 25.4, 25.2, 24.6, 23.8. IR (neat): 3658, 2981, 2889, 1473, 1462, 1382, 1252, 1150, 1072, 954 cm −1 . HRMS (m/z): [M+H] + calcd. for C 35 H 48 N 3 O 3 S, 590.3416; found, 590.3410.
Catalyst Evaluation at Low Temperature (General Procedure A)
[0150] A 20 mL reaction vial containing a stirring bar was charged with 3-methylglutaric anhydride (3a) (28.8 mg, 0.225 mmol) and 18 (17.7 mg, 0.030 mmol). The reaction vial was flushed with argon and fitted with a septum. MTBE (degassed) was then injected (1.5 mL, 0.2M) and the solution cooled to −30° C. The relevant thiol (0.30 mmol) was added via syringe and the resulting solution was stirred for the time indicated in Table 2. Conversion to the product was then monitored by 1 H-NMR spectroscopic analysis and the mixture was purified by flash-chromatography in order to separate the unreacted thiol from the thioester product.
Enantiomeric Excess, Conversion and S Factor Determination Procedures (Table 2)
[0151] The enantiomeric excess of each unreacted thiol was determined by CSP-HPLC after conversion to the corresponding Michael adduct with acrylonitrile. The enantiomeric excess of each ‘fast reacting’ thiol was determined by CSP-HPLC after aminolysis of the thioester product and derivatisation of the thiol to the corresponding Michael adduct with acrylonitrile. Conversion was determined using CSP-HPLC, where conversion=100×ee thiol /(ee thiol +ee thioester ) and the Selectivity Factor (S) was calculated according to the method developed by Kagan (Kagan, H. B. & Fiaud, J. C. Kinetic resolution. Top. Stereochem. 18, 249-330 (1988)).
Thiol Derivatisation (General Procedure B)
[0152]
[0153] The appropriate ‘slow reacting’ thiol (as obtained after flash-chromatography of the crude reaction mixture) was dissolved in CH 2 Cl 2 (1.0 mL) under an argon atmosphere. Triethylamine (5.0 eq.) and acrylonitrile (10.0 eq.) were added and the mixture was stirred at room temperature for 3 h. After removal of the volatiles under reduced pressure, the crude product was then purified by flash-chromatography to afford the desired Michael adduct in quantitative yield.
One-Pot Thioester Aminolysis and Thiol Derivatisation (General Procedure C)
[0154]
[0155] The appropriate thioester (as obtained after flash-chromatography of the reaction crude) was dissolved in CH 2 Cl 2 (3.0 mL). Acrylonitrile (10.0 eq.) and ammonia (35% aqueous solution, 3.0 mL) were added and the biphasic mixture was vigorously stirred at room temperature for 3 h. The reaction was then diluted with CH 2 Cl 2 (10.0 mL) and H 2 O (10.0 mL) and transferred to a separating funnel. The organic and aqueous layers were separated and the organic layer was dried over MgSO 4 , filtered and evaporated under reducer pressure. The desired Michael addition product was obtained in quantitative yield after purification by flash-chromatography.
[0000] Thioester Derivatisation as the corresponding o-nitrophenyl ester (Table 1)
[0156] Enantioselectivity data in Table 2 were obtained by recovering the unreacted thiol and separating it from the thioester products, which were then aminolysed to the other thiol antipode and analysed separately by CSP-HPLC. In Table 1 however, enantioselectivity data were available from analysis of the thioester diastereomers, which were readily separable by CSP-HPLC after conversion to the corresponding o-nitrophenylester derivatives via the procedure outlined below.
[0157] A 5 mL reaction vial containing a stirring bar was charged with the thioester (as obtained after flash-chromatography of the reaction crude), o-nitrophenol (2.0 eq.), DMAP (0.1 eq.), DCC (1.2 eq.) and CH 2 Cl 2 (0.05 M). The reaction vial was flushed with argon, fitted with a septum and stirred at room temperature for 12 h. The mixture was then filtered and the resulting clear solution was then purified by flash-chromatography.
Characterisation Data
[0158] Where indicated the absolute configuration of the thiols was established by following the literature procedure of Porto, S., Seco, J. M., Ortiz, A., Quiñoá, E. & Riguera, R. Chiral thiols: the assignment of their absolute configuration by 1 H NMR. Org. Lett. 24, 5015-5018 (2007).
[0000] 3-Methyl-4-(2-methyl-1-phenyl-propylsulfanylcarbonyl)-butyric acid (Table 1, Entry 19)
[0159] TLC (n-Hexane:EtOAc, 97:3, v/v): R f =0.38. 1 H NMR (400 MHz, CDCl 3 ): δ7.31-7.20; (m, 5H), 4.43; (d, J=8.0 Hz, 1H), 2.66-2.36; (m, 4H), 2.26-2.20; (m, 1H), 2.18-2.06; (m, 1H), 1.02; (d, J=7.0 Hz, 3H), 0.98; (d, J=6.5 Hz, 3H), 0.86; (d, J=6.5 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ197.0, 176.6, 141.5, 128.3, 128.2, 127.0, 55.2, 50.0, 40.0, 33.6, 27.9, 20.7, 20.5, 19.5; IR (neat): 2965, 2931, 1704, 1685, 1450, 1007, 911, 727, 697 cm −1 . HRMS (m/z): [M+Na] + calcd. for C 16 H 22 O 3 NaS, 317.1187; found, 317.1198. Note: Major diastereomer is 7a
[0000] 2-Methyl-1-phenyl-propane-1-thiol ((R)-1, Table 1, Entry 19)
[0160] After 68 h, the enantioenriched unreacted thiol was recovered in 90.4% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0161] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 12.3 min (minor enantiomer) and 14.0 min (major enantiomer).
[0162] Conversion=53.5%; S Factor=25.5.
[0163] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.52. [α] 20 D =+99.0; (c=0.54, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ7.36-7.20; (m, 5H), 3.78; (dd, J=8.5 and 5.0 Hz, 1H), 2.20-2.05; (m, 1H), 1.83; (d, J=5.0 Hz, 1H), 1.12; (d, J=6.5 Hz, 3H), 0.85; (d, J=6.5 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ143.8; (q), 127.9, 127.0, 126.5, 51.5, 35.4, 20.4, 20.3. HRMS (m/z): [M] + calcd. for C 10 H 14 S, 166.0816; found, 166.0810.
[0164] The absolute configuration of 1 was established following the literature procedure.
1-Phenylethanethiol ((R)-20, Table 2, Entry 1)
[0165] After 68 h, the enantioenriched unreacted (R)-thiol was recovered in 97.1% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following general procedure B.
[0166] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 14.6 min (minor enantiomer) and 16.1 min (major enantiomer).
[0167] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.49. [α] 20 D =+62.0; (c=0.38, EtOH); Lit. [α] 25 D =−88.7; (c=0.63, EtOH; 99% ee, (S)-enantiomer) 3 . 1 H NMR (400 MHz, CDCl 3 ): δ7.42-7.23; (m, 5H), 4.26; (app quintet, J=6.5 Hz, 1H), 2.02; (d, J=5.0 Hz, 1H), 1.70; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ145.4; (q), 128.2, 126.7, 125.9, 38.3, 25.6. HRMS (m/z): [M+H] + calcd. for C 8 H 11 S, 139.058; found, 139.0585.
[0168] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 57.4% ee. Conversion=62.8%; S Factor=14.5.
[0169] The absolute configuration of 20 was established following the procedure reported in the literature and (with agreement) by comparing the optical rotation with the literature data.
[0000] 1-Phenyl-propane-1-thiol ((R)-21, Table 2, Entry 2)
[0170] After 74 h, the enantioenriched unreacted (R)-thiol was recovered in 91.2% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0171] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 11.4 min (minor enantiomer) and 13.2 min (major enantiomer).
[0172] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.45. [α] 20 D =+70.2; (c=0.45, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ7.38-7.22; (m, 5H), 3.92; (dt, J=7.5 and 5.0 Hz, 1H), 2.07-1.90; (m, 3H), 0.96; (t, J=7.5 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ144.1; (q), 128.1, 126.7, 126.5, 45.5, 32.4, 12.1. HRMS (m/z): [M] + calcd. for C 9 H 12 S, 152.0660; found, 152.0653.
[0173] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 72.0% ee. Conversion=55.9%; S Factor=19.0.
[0174] The absolute configuration of 21 was established following the procedure reported in the literature.
[0000] 2,2-Dimethyl-1-phenyl-propane-1-thiol ((R)-22, Table 2, Entry 4)
[0175] After 96 h, the enantioenriched unreacted (R)-thiol was recovered in 93.8% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0176] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 9.5 min (major enantiomer) and 11.7 min (minor enantiomer).
[0177] TLC (Hexane 100%): R f =0.36. [α] 20 D =+105.4; (c=0.51, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ7.38-7.20; (m, 5H). 3.99; (d, J=5.0 Hz, 1H), 1.77; (d, J=5.0 Hz, 1H), 1.03; (s, 9H). 13 C NMR (100 MHz, CDCl 3 ): δ142.3; (q), 128.4, 127.2, 126.5, 55.4; (q), 35.1, 27.2. HRMS (m/z): [M] + calcd. for C 11 H 16 S, 180.0973; found, 180.0975.
[0178] After hydrolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 87.2% ee. Conversion=51.8%; S Factor=51.5.
[0179] The absolute configuration of 22 was established following the procedure reported in the literature. A repeat of this experiment (conv. 52%, S=50.4) resulted in the isolation of the unreacted (R)-thiol in 47% yield and 94.8% ee. After aminolysis of the combined thioester products the (S)-thiol was obtained in 43% isolated yield and 86.26% ee.
1-(4-Chloro-phenyl)-ethanethiol ((R)-23, Table 2, Entry 5)
[0180] After 72 h, the enantioenriched unreacted (R)-thiol was recovered in 95.3% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0181] CSP-HPLC analysis. Chiralpak AS (4.6 mm×25 cm), hexane/IPA: 96/4, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 17.1 min (major enantiomer) and 18.7 min (minor enantiomer).
[0182] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.52. [α] 20 D +73.7; (c=0.36, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ7.32; (br s, 4H), 4.23; (dq, J=7.0 and 5.0 Hz, 1H), 2.01; (d, J=5.0 Hz), 1.67; (d, J=7.0 Hz, 3H); 13 C NMR (100 MHz, CDCl 3 ): δ143.9; (q), 132.3; (q), 128.4, 127.3, 37.6, 25.5. HRMS (m/z): [M+H] + calcd. for C 8 H 10 SCl, 173.0192; found, 173.0191.
[0183] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 51.0% ee. Conversion=65.1%; S Factor=10.7.
[0184] The absolute configuration of 23 was established following the procedure reported in the literature.
1-(4-Methoxy-phenyl)-ethanethiol ((R)-24, Table 2, Entry 6)
[0185] After 5 d, the enantioenriched unreacted (R)-thiol was recovered in 87.1% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0186] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 98/2, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 22.3 min (minor enantiomer) and 24.1 min (major enantiomer).
[0187] TLC (Hexane:CH 2 Cl 2 , 8:2, v/v): R f =0.35. [α] 20 D =+47.3; (c=0.30, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ7.32; (d, J=8.5 Hz, 2H), 6.88; (d, J=8.5 Hz, 2H), 4.25; (dq, J=7.0 and 5.0 Hz, 1H), 3.82; (s, 3H), 2.00; (d, J=5.0 Hz), 1.67; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ158.6; (q), 137.9; (q), 127.4, 113.9, 55.3, 38.2, 26.3. HRMS (m/z): [M+H] + calcd. for C 9 H 13 OS, 169.0687; found, 169.0683.
[0188] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 68.8% ee. Conversion=55.8%; S Factor=15.0.
[0189] The absolute configuration of 24 was established following the procedure reported in the literature.
[0000] 1-Naphthalen-2-yl-ethanethiol ((R)-25, Table 2, Entry 7)
[0190] After 74 h, the enantioenriched unreacted thiol was recovered in 82.0% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0191] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 18.2 min (minor enantiomer) and 23.7 min (major enantiomer).
[0192] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.47. [α] 20 D =+53.7; (c=0.38, CH 2 Cl 2 ); Lit [α] 20 D =+65.9; (c=0.58, CH 2 Cl 2 ; 99% ee, (R)-enantiomer). 1 H NMR (400 MHz, CDCl 3 ): δ7.89-7.82; (m, 3H), 7.91-7.78; (m, 1H), 7.58; (dd, J=8.5 and 1.8 Hz, 1H), 7.54-7.47; (m, 2H), 4.44; (dq, J=7.0 and 5.0 Hz, 1H), 2.08; (d, J=5.0 Hz, 1H), 1.80; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ143.2; (q), 133.3; (q), 132.6; (q), 128.5, 127.8, 127.7, 126.2, 125.9, 125.0, 124.4, 39.0, 25.9. HRMS (m/z): [M+H] + calcd. for C 12 H 13 S, 189.0738; found, 189.0736.
[0193] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 59.5% ee. Conversion=57.9%; S Factor=9.7.
[0194] The absolute configuration of 25 was established following the procedure reported in the literature and (with agreement) by comparing the optical rotation with the literature data.
[0000] 1-Naphthalen-1-yl-ethanethiol ((R)-26, Table 2, Entry 8)
[0195] After 96 h, the enantioenriched unreacted (R)-thiol was recovered in 89.8% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0196] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 22.4 min (minor enantiomer) and 28.1 min (major enantiomer).
[0197] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.39. [α] 20 D =−188.0; (c=0.40, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ8.19; (d, J=8.5 Hz, 1H), 7.90; (d, J=8.0 Hz, 1H), 7.79; (d, J=8.0 Hz, 1H), 7.69; (d, J=7.0 Hz, 1H), 7.60; (t, J=7.0 Hz, 1H), 7.56-7.46; (m, 2H), 5.12-5.02; (m, 1H), 2.16; (d, J=5.0 Hz, 1H), 1.90; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ140.6; (q), 133.5; (q), 129.9; (q), 128.6, 127.3, 125.8, 125.2, 125.1, 122.5, 122.2, 33.2, 24.7. HRMS (m/z): [M+H] + calcd. for C 12 H 13 S, 189.0738; found, 189.0736.
[0198] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 84.7% ee. Conversion=51.5; S Factor=36.6.
[0199] The absolute configuration of 26 was established following the procedure reported in the literature.
[0200] In a repeat of this experiment the combined hemithioester products (70.0 mg, 0.22 mmol) were dissolved in CH 2 Cl 2 (2 mL) and treated with aq. NH 3 (2 mL). After stirring at room temperature for 4 h, the reaction was then diluted with CH 2 Cl 2 (10.0 mL) and H 2 O (5.0 mL) and transferred to a separating funnel. The organic and aqueous layers were separated and the aqueous layer was washed with CH 2 Cl 2 (2×10.0 mL). The aqueous layer was then acidified by addition of HCl (2 N) until pH=2.8 and evaporated under reduced pressure. After dissolving the mixture of product and salts in the minimum amount of H 2 O, the product was extracted with EtOAc (7×10 mL). The combined organic phases were then dried over magnesium sulphate and the solvent was removed under reduced pressure to afford the desired hemiamide as a white solid in 82% yield. (26.0 mg, 0.18 mmol). 93.0% ee as determined by CSP-HPLC after transformation to the corresponding o-nitrophenoxy ester, as per the procedure reported below.
[0201] 1 H NMR (400 MHz, DMSO-d 6 ): δ7.29; (s, 1H), 6.77; (s, 1H), 2.31-2.15; (m, 2H), 2.11-1.88; (m, 3H), 0.88; (d, J=6.3 Hz, 3H). 13 C NMR (100 MHz, DMSO-d 6 ): δ173.7; (q), 173.2; (q), 41.8, 40.6, 27.2, 19.4. HRMS (m/z): [M+Na] + calcd. for C 6 H 11 NO 3 Na, 168.0637; found, 168.0643.
[0202] The enantiomeric excess of the hemiamide was determined by CSP-HPLC after conversion to the corresponding o-nitrophenyl ester.
[0000]
[0203] A 5 mL reaction vial containing a stirring bar was charged with the hemiamide (20 mg, 0.137 mmol) and DCC (42.6 mg, 0.206 mmol). 2-nitrophenol (27.8 mg, 0.20 mmol). The vial was flushed with argon and dry THF (0.5 mL) was added. After 10 min, a solution of 2-nitrophenol (28.6 mg, 0.206 mmol) in dry THF (0.5 mL) was then added via syringe and the reaction mixture was stirred for 12 h at room temperature. After filtration of the resulting white precipitate, the filtrate was concentrated in vacuo and the residue purified by chromatography on silica gel to afford the desired compound in 30% yield (11.0 mg). 93.0% ee as determined by CSP-HPLC analysis (chromatogram below). Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 90/10, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 48.2 min (minor enantiomer) and 56.5 (major enantiomer).
[0000] 1-o-Tolyl-ethanethiol ((R)-27, Table 2, Entry 9)
[0204] After 48 h, the enantioenriched unreacted (R)-thiol was recovered in 95.3% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0205] CSP-HPLC analysis. Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 11.4 min (minor enantiomer) and 13.7 min (major enantiomer).
[0206] TLC (Hexane 100%): R f =0.37. [α] 20 589 =−17.4; (c=0.42, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ7.50; (d, J=7.5 Hz, 1H), 7.28-7.21; (m, 1H), 7.20-7.13; (m, 2H), 4.44; (dq, J=7.0 and 6.0 Hz, 1H), 2.43; (s, 3H), 1.93; (d, J=6.0 Hz, 1H), 1.72; (d, J=7.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ143.0; (q), 134.2; (q), 130.0, 126.4, 126.1, 124.7, 33.8, 25.0, 18.8. HRMS (m/z): [M] + calcd. for C 9 H 12 S, 152.0660; found, 152.0661.
[0207] After aminolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 94.2% ee. Conversion=50.3%; S Factor=126.0.
[0208] The absolute configuration of 27 was established following the procedure reported in the literature.
1-(2,4,6-Trimethyl-phenyl)-ethanethiol ((R)-28, Table 2, Entry 10)
[0209] After 48 h, the enantioenriched unreacted (R)-thiol was recovered in 98.1% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0210] CSP-HPLC analysis. Chiralpak AS (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm, retention times: 6.9 min (major enantiomer) and 8.2 min (minor enantiomer).
[0211] TLC (Hexane:CH 2 Cl 2 , 9:1 v/v): R f =0.44. [α] 20 589 =+102.6; (c=0.35, CHCl 3 ). 1 H NMR (400 MHz, CDCl 3 ): δ6.84; (s, 2H). 4.81; (dq, J=7.5 and 5.5 Hz, 1H), 2.57; (br s, 3H), 2.38; (br s, 3H), 2.26; (s, 3H) 2.20; (d, J=5.5 Hz, 1H), 1.73; (d, J=7.5 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ137.3, 136.4; (q), 135.8, 134.3; (q), 131.0; (q), 128.7; (q), 32.8, 23.1, 20.6, 20.2. HRMS (m/z): [m] + calcd. for C 11 H 16 S, 180.0973; found, 180.0978.
[0212] After hydrolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 96.4% ee. Conversion=50.4%; S Factor=265.0.
[0213] The absolute configuration of 28 was established following the procedure reported in the literature.
[0214] A repeat of this experiment (conv. 51%, S=249) resulted in the isolation of the unreacted (R)-thiol in 48% yield and 99.6% ee. After aminolysis of the combined thioester products the (S)-thiol was obtained in 44% isolated yield and 94.7% ee.
[0215] A repeat of this experiment at −45° C. resulted in the isolation of the (R)-thiol in 75.4% ee as determined by CSP-HPLC after conversion to the corresponding Michael addition adduct following the general procedure B.
[0216] After hydrolysis of the thioester product and derivatisation as per general procedure C, the reacted enantioenriched thiol was recovered in 98.3% ee. Conversion=43.4%; S Factor=275.0.
HPLC Calculation Methods
[0217] 3-Methyl-4-(2-methyl-1-phenyl-propylsulfanylcarbonyl)-butyric acid
[0218] Chiralpak OD-H (4.6 mm×25 cm), hexane/IPA: 95/5, 1.0 mL min −1 , RT, UV detection at 220 nm
[0000]
[0219] Chromatogram of the thioesters 7a-b (derivatised as their o-nitrophenyl esters for analysis via CSP-HPLC) from the reaction of 1 with 3 in the presence of triethylamine and an achiral thiourea as catalysts. The chromatogram clearly identifies the enantiomeric relationship between the peaks at 16.2 and 23.1 min (7a and its enantiomer) and between those at 17.9 min and 48.0 min (7b and its enantiomer).
[0220] Chromatogram of the thioesters 7a-b (derivatised as their o-nitrophenyl esters for analysis via CSP-HPLC) from the reaction of (S)-1 (84.5% ee) with 3 in the presence of triethylamine and an achiral thiourea as catalysts. The chromatogram clearly allows the identification of the major diastereomer 7a derived from attack of the enantioenriched thiol on a single prochiral carbonyl group to give (R)-stereochemistry at the carbon chain. This is the sense of stereoinduction expected from previous work and confirmed by conversion of a mixture of thioester diastereomers derived from the addition of 22 to 3 catalysed by 18 to a lactone of known configuration (see below). The 84.5% ee relationship between the peaks at 17 and 48 min confirms the identity of ent-7a. Likewise, the larger of the two peaks associated with the 7b diastereomer must therefore be ent-7b (i.e. with (S)-stereochemistry at the carbon bound to the sulphur atom).
[0000] Determination of the Sense of Stereoinduction Associated with the Desymmetrisation Reaction
[0221] The sense of stereoinduction associated with the desymmetrisation reaction was determined by conversion of the mixture of thioester diastereomers derived from the addition of 22 to 3 (i.e. Table 2, entry 4) to the lactone shown below and comparison of the optical rotation of that lactone derivative with the literature data (Irwin, A. J. & Jones, J. B. Asymmetric syntheses via enantiotopically selective horse liver alcohol dehydrogenase catalyzed oxidations of diols containing a prochiral center. J. Am. Chem. Soc. 99, 556-561 (1977)).
[0000]
[0222] The mixture of thioester diastereomers (92.5 mg, 0.30 mmol) was dissolved in THF (5 mL) and LiOH (12.6 mg, 0.30 mmol) was added. The reaction was heated to 50° C. and stirred for 15 minutes. LiClO 4 (159.6 mg, 1.50 mmol) and NaBH 4 (56.7 mg, 1.50 mmol) were then added and the reaction mixture was stirred at 50° C. for 1 h. The solvent was concentrated in vacuo, HCl (10 N, 5 mL) was added and the mixture was stirred at room temperature for 3 h. The desired product was extracted with CHCl 3 (3×10 mL), the combined extracts were dried (MgSO 4 ), concentrated in vacuo and purified by flash-chromatographyto give the lactone shown above as a colourless oil (22.0 mg, 0.19 mmol, 64% yield). [α] 20 D =−16.5; (c 0.22, CHCl 3 ), Lit. [α] 27 D =−24.8; (c=1.02, CHCl 3 ; 90% ee, (S)-enantiomer). 1 H NMR (400 MHz, CDCl 3 ): δ4.49-4.41; (m, 1H), 4.28; (td, J=10.5 and 3.5 Hz, 1H), 2.76-2.65; (m, 1H), 2.18-2.08; (m, 2H), 2.00-1.90; (m, 1H), 1.61-1.49; (m, 1H), 1.09; (d, J=6.0 Hz, 3H). 13 C NMR (100 MHz, CDCl 3 ): δ171.0; (q), 68.4, 38.1, 30.5, 26.4, 21.3.
[0223] By obtaining the (-) enantiomer of the lactone it is certain (from a comparison with the literature value for the (S) enantiomer of the lactone [Irwin, A. J. & Jones, J. B. Asymmetric syntheses via enantiotopically selective horse liver alcohol dehydrogenase catalyzed oxidations of diols containing a prochiral center. J. Am. Chem. Soc. 99, 556-561 (1977).]) that the major diastereomer derived from the addition of 22 to 3 possessed (R)-stereochemistry at the new stereocentre (which was the 3-position of the glutaric anhydride).
[0224] Chromatogram of the thioesters 7a-b (derivatised as their o-nitrophenyl esters for analysis via CSP-HPLC) from the reaction of 1 with 3 in the presence of catalyst 18 under the conditions outlined in Table 1 entry 19. The chromatogram clearly identifies (7a+ent-7a) as the major diastereomer (89:11 dr) and allows the calculation of ee esterA , ee esterB , ee desymm , C and S.
Calculations:
[0225] dr=(7a+ent-7a):(7b+ent-7b)
[0000] ee esterA =100×[(7a−ent-7a)/(7a+ent-7a)]
[0000] ee esterB =100×[(7b−ent-7b)/(7b+ent-7b)]
[0000] ee desymm =100×[(7a+7b)−(ent-7a+ent-7b)]/[(7a+7b)+(ent-7a+ent-7b)]
[0000] ee thioester =100×[(7a+ent-7b)−(7b+ent-7a)]/[(7a+ent-7b)+(7b+ent-7a)]
[0000] ee thiol =determined by CPS-HPLC analysis, see chromatogram below.
[0000] C=100×ee thiol /(ee thiol +ee thioester )
[0000] Note: C calculated this way correlated precisely (within experimental error) with the conversion levels measured by 1 H NMR spectroscopy in all cases.
[0000] S=In[(1−C)(1−ee thiol )]/In[(1−C)(1−ee thiol )]
[0000] or
[0000] In[(1−C)(1−C(1+ee thioester )]/In[1−C(1−ee thioester )]
[0000] KR of thiol 28 with Simultaneous Enantioselective Synthesis of a (R)-Pregabalin Precursor
[0226] A 20 mL reaction vial containing a stirring bar was charged with 3-isobutylglutaric anhydride (4) (102.1 mg, 0.60 mmol) and 18 (47.2 mg, 0.080 mmol). The reaction vial was flushed with argon and fitted with a septum. MTBE was then injected (4.0 mL, 0.2M) and the solution cooled to −30° C. 28 (0.30 mmol) was added dropwise via syringe and the resulting solution was stirred for 48 h. The mixture was the immediately loaded onto a column and the ‘slow reacting’ thiol enantiomer separated from the mixture by flash-chromatography (71.0 mg, 0.39 mmol, 98.7% ee as determined by CSP-HPLC after derivatisation as per general procedure B). The hemithioester product (29) was suspended in aq. NH 3 (3 mL) and stirred at room temperature for 4 h. The reaction was then diluted with CH 2 Cl 2 (10.0 mL) and H 2 O (5.0 mL) and transferred to a separating funnel. The organic and aqueous layers were separated and the aqueous layer was extracted with CH 2 Cl 2 (2×10.0 mL). The combined organic layers were then dried over MgSO 4 and the solvent removed under reduced pressure affording the ‘fast reacting’ (S)-thiol enantiomer (62.4 mg, 0.35 mmol, 95.5% ee as determined by CSP-HPLC after derivatisation as per general procedure B) after flash chromatography. Conversion=50.8%, S Factor=226.
[0227] The aqueous layer was then acidified by addition of HCl (8 N) and extracted with EtOAc (5×15 mL). The combined organic phases were then dried over magnesium sulphate and the solvent was removed under reduced pressure to afford the desired hemiamide as a white solid (71.2 mg, 0.38 mmol, 97.0% ee as determined by CSP-HPLC after transformation to the corresponding o-nitrophenoxy ester, as per the procedure reported below).
[0228] 1 H NMR spectrum of (S)-30 (400 MHz, DMSO-d 6 ): δ12.0; (br s, 1H), 7.27; (s, 1H), 6.74; (s, 1H), 2.22-1.91; (m, 5H), 1.66-1.51; (m, 1H), 1.09; (app t, J 6.6, 2H), 0.81; (d, J 6.6, 6H). 13 C NMR (100 MHz, DMSO-d 6 ): δ174.3; (q), 173.9; (q), 43.6, 40.2, 39.2, 30.1, 25.0, 23.2, 23.1. HRMS (m/z): [M+Na] + calcd. for C 9 H 17 NO 3 Na, 210.1106; found, 210.1114.
[0229] The words “comprises/comprising” and the words “having/including” when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
[0230] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. | Whilst methodologies for the Kinetic Resolution of alcohols are well established, no analogous direct methods exist for the highly selective, direct catalytic Kinetic Resolution of thiols (i.e., R—SH). The present invention relates to a method for resolving stereoisomeric mixtures of thiols. In particular, the present invention relates to purely organocatalytic mediated resolution of enantiomeric mixtures of thiols without the need for enzymes. Also disclosed are some novel catalysts. Such catalysts may comprise a cinchona alkaloid-derived moiety. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to animal control devices and more specifically to a device for restraining an animal from entering or exiting an area.
2. Description of the Prior Art
Animal control devices are not new in the prior art. By way of example:
U.S. Pat. No. 5,575,242 to Davis et al. discloses an animal constraint device.
U.S. Pat. No. 6,148,392 to Andre et al. discloses a device for preventing an animal from crossing a zone.
U.S. Pat. No. 6,151,276 to Peinetti discloses an echo-ranging boundary system for animals.
While the above-described devices fulfill their respective and particular objects and requirements, they do not describe an animal control device that provides for the advantages of the present invention. Therefore, a need exists for an improved animal control device. In this respect, the present invention substantially departs from the conventional concepts and designs of the prior art.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of animal control devices now present in the prior art, the new animal control device overcomes the above-mentioned disadvantages and drawbacks or the prior art. As such, the general purpose of the animal control device, described subsequently in greater detail, is to provide an animal control device which has all of the advantages of the prior art mentioned heretofore and many novel features that result in an improved animal control device which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in combination thereof.
To accomplish this, the present animal control device comprises a transmission strip and a receiver and emission collar unit for attaching to animals. The device is used for one animal or even several animals simultaneously. Additional collars are available for simultaneous, multiple animal usage. The transmission strip is comprised of transmission wires embedded within a flexible rubber strip of thin and substantially flat profile, with preferably slightly rounded outer edges. The strip is thin so that it is not likely to cause tripping and also so that it may be placed underneath a rug, carpet, or cushions or the like and not be visually intrusive.
Further, the strip is component extendable and flexible so that it can be arranged to accommodate either large or small areas and also be formed into various gentle curves. Strips plug into each other for extension of the animal control device, with an end cap for terminating the strip at the desired length. Plug design is basic with a male/female construction. Preferably, the first strip, with incorporated controls, is equipped with the female plug disposed at the end opposite the controls, with additional strips featuring male and female ends, and the end cap therefore being male. Another embodiment reverses that male female relationship, as shown in the following FIGS. 1–5 . Controls for on/off operation and for transmission frequency are conveniently mounted on the strip.
The collar receiver/emitter resembles a typical collar with the addition of a small receiver/emitter. The receiver/emitter is a thin hexahedron with rounded corners and edges. The emitter projects a warning to the animal. Warnings are either audible to human ears or ultrasonic. Additional embodiments of the receiver/emitter replace the sound chip with mechanisms for delivering warnings in the form of mild electrical shock or vibration. The collar is fitted to the animal needing control. The transmitter strip is placed where a boundary is to be established, one which is not to be crossed. The transmitter is then plugged in and turned on and adjusted by the frequency control. An animal proximal to the strip is thereby discouraged from crossing that boundary.
The transmitter strip houses a battery backup to allow for conditions when standard AC current is not provided or convenient. An internal modulator automatically switches between battery or AC current power. The animal control device is basic, durable, inexpensively produced and portable.
Thus has been broadly outlined the more important features of the animal control device so that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. Numerous objects, features and advantages of the animal control device will be readily apparent to those of ordinary skill in the art upon reading the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the animal control device when taken in conjunction with the accompanying drawings. In this respect, before explaining the current embodiments of the animal control device in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth in the following description or illustration. The invention is capable of other embodiments and of being practiced and carried out in various ways. It is also to be understood that the phraseology and terminology employed herein are for purposes of description and should not be regarded as limiting.
Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the design of other structures, methods and systems for carrying out the several purposes of the animal control device. It is therefore important that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
A primary object, then, of animal control device is to control animal access to or from desired areas.
Another object of the animal control device is to provide for flexibly shaped and desired length installations.
It is an additional object of the animal control device to provide control for several animals with one transmitter strip.
Yet another object of the animal control device is to provide for battery backup power.
These together with additional objects of the animal control device, along with various novel features that characterize the invention are particularly pointed out in the claims forming a part of this disclosure. For better understanding of the animal control device, its operating advantages and specific objects attained by its uses, refer to the accompanying drawings and description.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a perspective view of the transmitter strip of the animal control device.
FIG. 2 is a perspective view of the animal collar with receiver/emitter.
FIG. 3 is a cross-sectional view of the transmitter strip.
FIG. 4 is a perspective view of the transmitter strip with extension and end cap.
FIG. 5 is a diagram of the electronic components of the animal control device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular FIGS. 1 through 5 thereof, the preferred embodiment of the animal control device employing the principles and concepts of the present invention and generally designated by the reference number 10 will be described. Referring FIGS. 1 and 2 , the animal control device 10 comprises transmitter strip 11 and collar unit 22 . Strip 11 ( FIG. 1 ) is about 48 inches long and a substantially parallelepiped flexible strip. Strip 11 further comprises, at distal end, end cap 12 . The shape of end cap 12 matches and fits to strip 11 by way of female receptacle 20 and female receptacle 21 . End cap 12 plugs onto distal end of strip 11 by way of male extension plug 18 , which fits into receptacle 20 of cap 12 , and male extension plug 19 , which fits into receptacle 21 of cap 12 . Cap 12 thereby securely and safely terminates transmitter wire 34 and transmitter wire 35 ( FIG. 3 ) within plugs 18 and 19 . Cap 12 contains a loop (not shown) for transmitter wires 34 and 35 .
Strip 11 further comprises, at proximal end, switch/battery housing 26 , also identically shaped to the remainder of strip 11 . Frequency control housing 27 , also of matching shaped comprises the distal end of strip 11 . On/off switch 14 is disposed upwardly within housing 26 . Housing 26 further houses back up battery (not shown) for utilizing invention 10 without standard outlet AC power (not shown). Electrical cord 16 provides power via AC plug 17 when standard outlet power is utilized. Round knob frequency control 15 , oriented vertically within housing 27 , provides for adjustment of transmitter strip 11 signal strength.
Referring to FIG. 3 , flexible strip 11 cross section further defines transmitter wire 34 and transmitter wire 35 . Wires 34 and 35 continue throughout the longitudinal distance of strip 11 and strip 13 extension ( FIG. 4 ). Referring to FIG. 4 , strip 11 is provided with strip extension 13 . Cap 12 fits to extension 13 exactly as on strip 11 . Extension 13 plugs into strip 11 as did cap 12 in FIG. 1 . Invention 10 is thereby extended. Each strip 11 and strip 13 is about 48 inches in length. Strips 11 and 13 are rubberized and flexible and may be shaped into various configurations (not shown) other than straight positioning shown.
Receiving and emission of animal control device 10 comprises collar unit 22 . Unit 22 comprises collar strap 33 for encircling an animal's neck (not shown). Strap 33 further comprises buckle 31 and typical male and female ends, each on an opposite end of strap 33 . Receiver/emitter 23 is disposed centrally along strap 33 and fixedly surrounds a relatively small portion thereof. Receiver/emitter 23 internally comprises collar receiver 42 and sound chip 43 , joined by receiver/sound chip electrical connect 53 ( FIG. 5 ).
Referring to FIG. 5 , strip 11 further comprises AC power supply 40 , electrical controls 41 , battery backup 55 and strip 11 transmitter wire 34 and transmitter wire 35 ( FIG. 3 ). Supply/controls electrical connect 50 connects supply 40 to controls 41 . Controls/battery electrical connect 51 connects controls 41 to battery backup 55 . Controls/transmitter electrical connect 52 connects controls 41 to wire 34 and wire 35 .
In use, strip 11 , with or without strip/s 13 , is positioned across any area (not shown) from which an animal (not shown) is to be bounded either within or without. The area may prohibit access to a doorway (not shown), a couch (not shown), or any imaginable area distinction (not shown). Invention 10 prohibits entrance or exit of an animal by emitting sound unpleasant to the animal. End cap 12 is installed to terminate strip 11 or strip/s 13 . Collar unit 22 is fitted to the animal to be controlled and is secured by typical buckle 31 . Buckle adjustment 32 is adjusted such that unit 22 correctly fits.
Available power either from either standard AC via plug 17 or from internal battery backup 55 is utilized. Switch 14 is turned to on position. Frequency control 15 is set at mid level. The animal is then placed within the area to which it is to be contained, or without the area to which it is to be denied admission. If the animal approaches to within proximity of strip 11 , airwave transmission 54 from transmitter wires 34 and 35 is received by collar receiver 42 of collar unit 22 . Upon receipt of transmission 54 from wires 34 and 35 , collar receiver 42 signals sound chip 43 , via receiver/sound chip electrical connect 53 . If the animal is not repulsed, frequency control 15 is adjusted further until the animal is. A replaceable battery (not shown) is also housed within receiver/emitter 23 . The battery powers receiver 42 and sound chip 43 . Chip 43 emits sound to alarm the animal and prevent animal access to denied areas. Invention 10 is inoperative when switch 14 is in off position.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the animal control device, to include variations in size, materials, shape, form, function and the manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | An animal control device for prohibiting animal access to or egress from a desired area. The transmitter comprises a flexible transmitter strip and strip extensions that are designed to be physically unobtrusive. The strip further comprises on/off switch, frequency control, AC power plug and a battery backup. The receiver and emission component of the device comprises a removable and adjustable animal collar, or plurality of animal collars which emit audible sound, ultrasound, vibration, or mild electric shock. | 0 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to jewelry and more specifically, to bracelets and methods of assembling such.
[0002] Over the years, stories providing lessons have been passed down through the generations. For example, in one such story, a young child tied a string around one of their fingers to remind themselves of something that they should not forget. Over time, many of such stories and their lessons have evolved. Today, jewelry, such as bracelets, displaying a multitude of slogans, advertisements, and ornamentation are commercially available. For example, one well known bicyclist sponsors the commercial sale of rubber bracelets that display a slogan that the bicyclist wants to keep in the forefront of people's minds. Other individuals have been known to wear a rubber band around their wrist as a reminder of something they should or should not forget.
[0003] While wearing such jewelry, in particular bracelets having elastic qualities, at least some individuals may pull a portion of the bracelet or rubber band away from their wrist and let the rubber band snap against their wrist. For example, some individuals may snap the bracelets as a nervous habit, while others may snap the bracelet as a reminder to stay focused and to prevent their minds from wandering. However, over time, the stretchable portions of such bracelets may break, wear out, or lose their stretchable characteristics. Moreover, depending on the circumstances, the individual may want to display different indicia. As such, to display different indicia, or once the stretchable portions of such bracelets have lost their stretchable properties and/or have broken, generally the user must buy a second bracelet.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one embodiment, a method of assembling a bracelet is provided. The method includes providing a display member having a first end, a second end, and at least two openings defined therein. The method further includes providing at least one band having a first end and a second end. The method also includes coupling the at least one band to the display member such that one end of the band is inserted into each of the at least two openings and such that a loop is formed around the second end of the display member.
[0005] In a further embodiment, a method of assembling a bracelet is provided. The method includes providing a display member having a first end, a second end, and at least two openings defined therein, and providing at least one band having a first end and a second end. The method further includes coupling the at least one band to the display member such that one end of the band is inserted into one of the at least two openings and the other end of the band is inserted into a second of the at least two openings.
[0006] In another embodiment, a bracelet assembly is provided. The bracelet assembly includes a display member including a body extending from a first end to an opposite second end. The body includes at least two openings defined therein. The bracelet assembly further includes at least one band including a first end and a second end. The at least one band is configured to be coupled to the display member such that one of the band first and second ends is inserted into each of the at least two openings and such that a loop is formed around the display member second end.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of an exemplary bracelet assembly;
[0008] FIG. 2 is a perspective view of an exemplary display member that may be used with the bracelet assembly shown in FIG. 1 ;
[0009] FIG. 3 is a perspective view of an exemplary band that be used with the bracelet assembly shown in FIG. 1 ;
[0010] FIG. 4 is a partially assembled view of the bracelet assembly shown in FIG. 1 ;
[0011] FIG. 5 is an assembled view of the bracelet assembly shown in FIG. 1 ; and
[0012] FIG. 6 is an alternative embodiment of the bracelet assembly shown in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention is described below in reference to its application in connection with a bracelet assembly including a looped band as will be appreciated by one of ordinary skill in the art.
[0014] FIG. 1 is a front view of a bracelet assembly 100 , and FIG. 2 is a perspective view of a display member 102 used with bracelet assembly 100 . FIG. 3 is a perspective view of an exemplary band 104 used with bracelet assembly 100 . FIG. 4 is a partially assembled view of bracelet assembly 100 .
[0015] In the exemplary embodiment, member 102 includes a body 101 that is substantially rectangular having four corners 106 , 108 , 110 , and 112 connected together by four sides 114 , 116 , 118 , and 120 . Alternatively, body 101 may be formed with an non-rectangular shape. Member 102 has a length L 1 defined between opposite sides 116 and 120 , a height H 1 defined between opposite sides 114 and 118 , and has a thickness T 1 defined between an outer face 122 and an opposite inner face 124 . As will be appreciated by one of ordinary skill in the art, assembly 100 , display member 102 , and band 104 may have any suitable size, shape and/or configuration that enables assembly 100 to function as described herein.
[0016] In the exemplary embodiment, display member 102 includes a raised border 126 that extends outward from outer surface 122 along each side 114 , 116 , 118 , and 120 . Specifically, in the exemplary embodiment, border 126 substantially circumscribes outer surface 122 . Alternatively, display member 102 does not include border 126 . In the exemplary embodiment, display member 102 is fabricated from a metallic material. Alternatively, display member 102 may be fabricated from any material that enables bracelet assembly 100 to function as described herein, such as, but not limited to, a plastic material, a composite material, and/or a paper material. In an alternative embodiment, display member 102 is fabricated from a plurality of layers that provide structural strength to member 102 .
[0017] Display member 102 includes at least two openings 130 and 132 defined therein. In an alternative embodiment, display member 102 includes any number of openings 130 and 132 that enables bracelet assembly 100 to function as described herein. Openings 130 and 132 are separated by a distance L 2 . In the exemplary embodiment, openings 130 and 132 each include a substantially circular portion 133 and 135 , and a slotted portion 139 , respectively. Alternatively, at least one of openings 130 and/or 132 includes only circular portion 133 or 135 . In another embodiment, at least one opening 130 and/or 132 only includes slotted portion 139 .
[0018] In the exemplary embodiment, opening 130 is positioned proximate side 120 , and opening 132 is positioned proximate side 116 . Specifically, in the exemplary embodiment, openings 130 and 132 are positioned a distance L 3 from side 114 , and a distance L 4 from side 118 , respectively. In the exemplary embodiment, distances L 3 and L 4 are approximately equal. Moreover, in the exemplary embodiment, each portion 133 and 135 has a diameter D 1 . Alternatively, one portion 133 or 135 has a larger diameter than the other portion 133 or 135 . In another embodiment, at least one of portions 133 or 135 is non-circular. In an alternative embodiment, openings 130 and 132 may have any suitable size, shape, orientation, and/or configuration that enables bracelet assembly 100 to function as described herein.
[0019] In the exemplary embodiment, display member 102 also includes a raised border 134 that extends outward from outer surface 122 about each opening 130 and 132 . Specifically, in the exemplary embodiment, border 134 circumscribes each opening 130 and 132 . In the exemplary embodiment, each border 134 provides structural strength and reinforcement to each opening 130 and 132 . Border 134 also facilitates retaining band 104 within openings 130 and 132 as described in more detail below.
[0020] Moreover, in the exemplary embodiment, display member 102 includes indicia 128 displayed thereon across surface 122 . In one embodiment, the indicia 128 communicates a phrase. For example, indicia 128 may include, but is not limited to including, printed text, designs, figures, ornamentation, and/or any combination thereof, that attract attention, enables a user to read indicia 128 while wearing bracelet assembly 100 and/or that reminds the user of something not to be, or to be, forgotten. In the exemplary embodiment, indicia 128 extends between openings 130 and 132 . In an alternative embodiment, indicia 128 may extend over any surface such as, but not limited to surfaces 122 or 124 , and/or portion of assembly 100 that enables assembly 100 to function as described herein. For example, in an alternative embodiment, band 104 includes indicia 128 .
[0021] In the exemplary embodiment, display member 102 also includes at least one slot 136 defined therein. Specifically, in the exemplary embodiment, slot 136 is substantially linear and extends a length L 5 between an opening 130 and 132 and an outer side 114 , 116 , 118 , or 120 of display member 102 . Slot 136 has a width W 2 measured between opposing surfaces 122 or 124 , and extends at an angle θ with respect to side 118 . In the exemplary embodiment, angle θ is an acute angle. In an alternative embodiment, slot 136 may be oriented at any angle θ and have any size, shape, and/or configuration that enables bracelet assembly 100 to function as described herein. Moreover, in an alternative embodiment, display member 102 may include any number of slots 136 that enables bracelet assembly 100 to function as described herein. For example, display member 102 may include additional slots 136 extending from opening 130 and/or additional slots 137 extending from opening 132 .
[0022] In the exemplary embodiment, band 104 is fabricated from a stretchable material, such as natural rubber or elastic material such that band 104 is flexible. For example, band 104 may be twisted and/or turned as band 104 is coupled to display member 102 as described in more detail below. In the exemplary embodiment, band 104 is a continuous loop that has a diameter D 2 . More specifically, band 104 is sized to enable at least a portion of band 104 to be inserted through slot 136 and/or openings 130 and/or 132 . In an alternative embodiment, band 104 is fabricated from a plurality of segments coupled together. In one embodiment, band 104 includes a mechanism (not shown) that enables the length of band 104 to be adjusted to accommodate individuals having different sized wrists and/or ankles to wear bracelet assembly 100 . Alternatively, band 104 may be fabricated from any material that enables assembly 100 to function as described herein. For example, band 104 may be fabricated from, but is not limited to being fabricated from, cloth, yarn, synthetic rubber, and/or any combination thereof.
[0023] FIG. 5 is an assembled view of bracelet assembly 100 . During assembly, band 104 is removably coupled to display member 102 . Specifically, in the exemplary embodiment, band 104 is folded over itself, such that band 104 has length L 6 extending between a first end 146 and a second end 148 . First end 146 is inserted through opening 132 until a first loop 150 and a second loop 152 are each formed. A portion of loop 150 is then inserted through loop 152 and loop 150 is pulled in a direction 154 , away from display member 102 , until loop 152 is secured to display member 102 . End 146 of band 104 is then inserted into opening 130 by sliding loop 150 through slot 136 . Band 104 is then slid from side 118 towards opening 130 until band 104 is securely coupled within portion 133 . As such, a loop 156 is defined in band 104 when band 104 is fully coupled to display member 102 . A user 158 may insert their hand 160 through loop 156 such that bracelet assembly 100 is secured to the user's wrist 162 . While wearing bracelet assembly 100 , user 158 may pull a portion of band 104 a distance away from wrist 162 and let the rubber band snap against their wrist.
[0024] FIG. 6 is an alternative embodiment of bracelet assembly 100 . In an alternative embodiment, display member 102 includes openings 130 and 132 and slots 136 and 137 , respectively. Generally, slot 137 is similar to slot 136 , and like components are identified with like reference numerals. Slot 137 forms an angle γ with side 118 wherein angle γ is an acute angle. In an alternative embodiment, angle γ is any size angle. During assembly, a portion of band 104 is slid through slot 136 towards opening 130 , and a portion of band 104 is slid through slot 137 towards opening 132 . Band 104 is slid through slots 136 and 137 in direction 154 , away from display member 102 , until band 104 is securely coupled within openings 130 and 132 . When band is coupled to display member 102 , band 104 forms loop 156 . In this embodiment, a portion of band 104 extends along a portion and is substantially adjacent to second surface 124 .
[0025] The above-described bracelet assembly may act as a reminder to individuals. At least some individuals may pull a portion of the bracelet or rubber band away from their wrist and let the rubber band snap against their wrist. For example, some individuals may snap the bracelets as a nervous habit, while others may snap the bracelet as a reminder to stay focused and to prevent their minds from wandering. As such, the above-described bracelet is a suitable replacement for users that typically wear rubber bands around their wrist as a self-imposed reminder. However, over time, the stretchable portions of such bracelets may break, wear out, or lose their stretchable characteristics. As such, the above-described bracelet assembly enables a user may easily replace the band and/or display member restoring the bracelet assembly to its original configuration. Also, the above-described bracelet assembly may display a multitude of slogans, advertisements, and ornamentation that are commercially available. As such, if the individual wants to display different indicia, the user may easily replace the band and/or the display member.
[0026] An exemplary embodiment of a bracelet assembly is described above in detail. The bracelet assembly illustrated is not limited to the specific embodiments described herein, but rather, components of the assembly may be utilized independently and separately from other components described herein.
[0027] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | A method of assembling a bracelet is provided. The method includes providing a display member having a first end, a second end, and at least two openings defined therein. The method further includes providing at least one band having a first end and a second end. The method also includes coupling the at least one band to the display member such that one end of the band is inserted into each of the at least two openings and such that a loop is formed around the second end of the display member. | 0 |
FILED OF THE INVENTION
[0001] The instant invention relates generally to hydrogen storage materials and more specifically to a new composite hydrogen storage material having heretofore unheard of properties. Specifically the instant hydrogen storage material provides for a storage capacity of up to 4.86 weight percent hydrogen with a high adsorption rate at temperatures as low as 30° C. and an absorption pressure of less than about 150 PSI. The composite materials are light weight and absorb at least 3 weight percent in less than two minutes at 30° C. More remarkably, the composite materials also have the ability to fully desorb the stored hydrogen at temperatures as low as 250° C., an ability not heretofore seen in materials with such a high total storage capacity. Even more amazingly the same material can desorb 2.51 weight percent of the stored hydrogen at 90° C. and 1.2 weight percent at 30° C. In addition these material are relatively inexpensive and easy to produce.
BACKGROUND OF THE INVENTION
[0002] Growing energy needs have prompted specialists to take cognizance of the fact that the traditional energy resources, such as coal, petroleum or natural gas, are not inexhaustible, or at least that they are becoming costlier all the time, and that it is advisable to consider replacing them with hydrogen.
[0003] Hydrogen may be used, for example, as fuel for internal-combustion engines in place of hydrocarbons. In this case it has the advantage of eliminating atmospheric pollution through the formation of oxides of carbon, nitrogen and sulfur upon combustion of the hydrocarbons. Hydrogen may also be used to fuel hydrogen-air fuel cells for production of the electricity needed for electric motors.
[0004] One of the problems posed by the use of hydrogen is its storage and transportation. A number of solutions have been proposed:
[0005] Hydrogen may be stored under high pressure in steel cylinders, but this approach has the drawback of requiring hazardous and heavy containers which are difficult to handle (in addition to having a low storage capacity of about 1% by weight). Hydrogen may also be stored in cryogenic containers, but this entails the disadvantages associated with the use of cryogenic liquids; such as, for example, the high cost of the containers, which also require careful handling. There are also “boil off” losses of about 2-5% per day.
[0006] Another method of storing hydrogen is to store it in the form of a hydride, which then is decomposed at the proper time to furnish hydrogen. The hydrides of iron-titanium, lanthanum-nickel, vanadium, and magnesium have been used in this manner, as described in French Pat. No. 1,529,371.
[0007] Since the initial discovery that hydrogen could be stored in a safe, compact solid state metal hydride form, researchers have been trying to produce hydrogens storage materials which have optimal properties. Generally, the ideal material properties that these researchers have been attempting to achieve are: 1) a high hydrogen storage capacity; 2) light weight materials; 3)adequate hydrogen absorption/desorption temperatures; 4) adequate absorption/desorption pressures; 5) fast absorption kinetics; and 6) a long absorption/desorption cycle life. In addition to these material properties, ideal materials would be inexpensive and easy to produce.
[0008] The MgH 2 —Mg system is the most appropriate of all known metal-hydride and metal systems that can be used as reversible hydrogen-storage systems because it has the highest percentage by weight (7.65% by weight) of theoretical capacity for hydrogen storage and hence the highest theoretical energy density (2332 Wh/kg; Reilly & Sandrock, Spektrum der Wissenschaft, April 1980, 53) per unit weight of storage material.
[0009] Although this property and the relatively low price of magnesium make the MgH 2 —Mg seem the optimum hydrogen storage system for transportation, for hydrogen-powered vehicles that is, its unsatisfactory kinetics have prevented it from being used up to the present time. It is known for instance that pure magnesium can be hydrided only under drastic conditions, and then only very slowly and incompletely. The dehydriding rate of the resulting hydride is also unacceptable for a hydrogen storage material (Genossar & Rudman, Z. f. Phys. Chem., Neue Folge 116, 215 [1979], and the literature cited therein).
[0010] Moreover, the hydrogen storage capacity of a magnesium reserve diminishes during the charging/discharging cycles. This phenomenon may be explained by a progressive poisoning of the surface, which during charging renders the magnesium atoms located in the interior of the reserve inaccessible to the hydrogen.
[0011] To expel the hydrogen in conventional magnesium or magnesium/nickel reserve systems, temperatures of more than 250° C. are required, with a large supply of energy at the same time. The high temperature level and the high energy requirement for expelling the hydrogen have the effect that, for example, a motor vehicle with an internal combustion engine, cannot exclusively be operated from these alloys. This occurs because the energy contained in the exhaust gas, in the most favorable case (full load), is sufficient for meeting only 50% of the hydrogen requirement of the internal combustion engine from a magnesium or magnesium/nickel alloy. Thus, the remaining hydrogen demand must be taken from another hydride alloy. For example, this alloy can be titanium/iron hydride (a typical low-temperature hydride store) which can be operated at temperatures down to below 0° C. These low-temperature hydride alloys have the disadvantage of having a low hydrogen storage capacity.
[0012] Storage materials have been developed in the past, which have a relatively high storage capacity but from which hydrogen is nevertheless expelled at temperatures of up to about 250° C. U.S. Pat. No. 4,160,014 describes a hydrogen storage material of the formula Ti [1−x] Zr [x] Mn [2−y−z] Cr [y] V [z] , wherein x=0.05 to 0.4, y=0 to 1 and z=0 to 0.4. Up to about 2% by weight of hydrogen can be stored in such an alloy. In addition to this relatively low storage capacity, these alloys also have the disadvantage that the price of the alloy is very high when metallic vanadium is used.
[0013] Moreover, U.S. Pat. No. 4,111,689 has disclosed a storage alloy which comprises 31 to 46% by weight of titanium, 5 to 33% by weight of vanadium and 36 to 53% by weight of iron and/or manganese. Although alloys of this type have a greater storage capacity for hydrogen than the alloy according to U.S. Pat. No. 4,160,014, hereby incorporated by reference, they have the disadvantage that temperatures of at least 250° C. are necessary in order to completely expel the hydrogen. At temperatures of up to about 100° C., about 80% of the hydrogen content can be discharged in the best case. However, a high discharge capacity, particularly at low temperatures, is frequently necessary in industry because the heat required for liberating the hydrogen from the hydride stores is often available only at a low temperature level.
[0014] In contrast to other metals or metal alloys, especially such metal alloys which contain titanium or lanthanum, magnesium is preferred for the storage of hydrogen not only because of its lower material costs, but above all, because of its lower specific weight as a storage material. However, the hydriding
Mg+H 2 →MgH 2
is, in general, more difficult to achieve with magnesium, inasmuch as the surface of the magnesium will rapidly oxidize in air so as to form stable MgO and/or Mg(OH) 2 surface layers. These layers inhibit the dissociation of hydrogen molecules, as well as the absorption of produced hydrogen atoms and their diffusion from the surface of the granulate particles into the magnesium storage mass.
[0015] Intensive efforts have been devoted in recent years to improve the hydriding ability of magnesium by doping or alloying it with such individual foreign metals as aluminum (Douglass, Metall. Trans. 6a, 2179 [1975]) indium (Mintz, Gavra, & Hadari, J. Inorg. Nucl. Chem. 40, 765 [1978]), or iron (Welter & Rudman, Scripta Metallurgica 16, 285 [1982]), with various foreign metals (German Offenlegungsschriften 2 846 672 and 2 846 673), or with intermetallic compounds like Mg 2 Ni or Mg 2 Cu (Wiswall, Top Appl. Phys. 29, 201 [1978] and Genossar & Rudman, op. cit.) and LaNi 5 (Tanguy et al., Mater. Res. Bull. 11, 1441 [1976]).
[0016] Although these attempts did improve the kinetics somewhat, certain essential disadvantages have not yet been eliminated from the resulting systems. The preliminary hydriding of magnesium doped with a foreign metal or intermetallic compound still demands drastic reaction conditions, and the system kinetics will be satisfactory and the reversible hydrogen content high only after many cycles of hydriding and dehydriding. Considerable percentages of foreign metal or of expensive intermetallic compound are also necessary to improve kinetic properties. Furthermore, the storage capacity of such systems are generally far below what would theoretically be expected for MgH 2 .
[0017] It is known that the storage quality of magnesium and magnesium alloys can also be enhanced by the addition of materials which may help to break up stable oxides of magnesium. For example, such an alloy is Mg 2 Ni, in which the Ni appears to form unstable oxides. In this alloy, thermodynamic examinations indicated that the surface reaction Mg 2 Ni+O 2 →2MgO+Ni extended over nickel metal inclusions which catalyze the hydrogen dissociation-absorption reaction. Reference may be had to A. Seiler et al., Journal of Less-Common Metals 73, 1980, pages 193 et seq.
[0018] One possibility for the catalysis of the hydrogen dissociation-absorption reaction on the surface of magnesium lies also in the formation of a two-phase alloy, wherein the one phase is a hydride former, and the other phase is a catalyst. Thus, it is known to employ galvanically-nickeled magnesium as a hydrogen storage, referring to F. G. Eisenberg et al. Journal of Less-Common Metals 74, 1980, pages 323 et seq. However, there were encountered problems during the adhesion and the distribution of the nickel over the magnesium surface.
[0019] In order to obtain an extremely dense and good adherent catalyst phase under the formation alone of equilibrium phases, it is also known that for the storage of hydrogen there can be employed an eutectic mixture of magnesium as a hydride-forming phase in conjunction with magnesium copper (Mg 2 Cu), referring to J. Genossar et al., Zeitschrift fur Physikalische Chemie Neue Folge 116, 1979, pages 215 et seq. The storage capacity per volume of material which is achieved through this magnesium-containing granulate does not, however, meet any high demands because of the quantity of magnesium copper which is required for the eutectic mixture.
[0020] The scientists of this era looked at various materials and postulated that a particular crystalline structure is required for hydrogen storage, see, for example, “Hydrogen Storage in Metal Hydride”, Scientific American, Vol. 242, No. 2, pp. 118-129, February, 1980. It was found that it is possible to overcome many of the disadvantages of the prior art materials by utilizing a different class of materials, disordered hydrogen storage materials. For example, U.S. Pat. No. 4,265,720 to Guenter Winstel for “Storage Materials for Hydrogen” describes a hydrogen storage body of amorphous or finely crystalline silicon. The silicon is preferably a thin film in combination with a suitable catalyst and on a substrate.
[0021] Laid-open Japanese Patent Application No. 55-167401, “Hydrogen Storage Material,” in the name of Matsumato et al, discloses bi or tri-element hydrogen storage materials of at least 50 volume percent amorphous structure. The first element is chosen from the group Ca, Mg, Ti, Zr, Hf, V, Nb, Ta, Y and lanthanides, and the second from the group Al, Cr, Fe, Co, Ni, Cu, Mn and Si. A third element from the group B, C, P and Ge can optionally be present. According to the teaching of No. 55-167401, the amorphous structure is needed to overcome the problem of the unfavorably high desorption temperature characteristic of most crystalline systems. A high desorption temperature (above, for example, 150° C.) severely limits the uses to which the system may be put.
[0022] According to Matsumoto et al, the material of at least 50% amorphous structure will be able to desorb at least some hydrogen at relatively low temperatures because the bonding energies of the individual atoms are not uniform, as is the case with crystalline material, but are distributed over a wide range.
[0023] Matsumoto et al claims a material of at least 50% amorphous structure. While Matsumoto et al does not provide any further teaching about the meaning of the term “amorphous,” the scientifically accepted definition of the term encompasses a maximum short range order of about 20 Angstroms or less.
[0024] The use by Matsumato et al of amorphous structure materials to achieve better desorption kinetics due to the non-flat hysteresis curve is an inadequate and partial solution. The other problems found in crystalline hydrogen storage materials, particularly low useful hydrogen storage capacity at moderate temperature, remain.
[0025] However, even better hydrogen storage results, i.e., long cycle life, good physical strength, low absorption/desorption temperatures and pressures, reversibility, and resistance to chemical poisoning, may be realized if full advantage is taken of modification of disordered metastable hydrogen storage materials. Modification of disordered structurally metastable hydrogen storage materials is described in U.S. Pat. No. 4,431,561 to Stanford R. Ovshinsky et al. for “Hydrogen Storage Materials and Method of Making the Same”. As described therein, disordered hydrogen storage materials, characterized by a chemically modified, thermodynamically metastable structure, can be tailor-made to possess all the hydrogen storage characteristics desirable for a wide range of commercial applications. The modified hydrogen storage material can be made to have greater hydrogen storage capacity than do the single phase crystalline host materials. The bonding strengths between the hydrogen and the storage sites in these modified materials can be tailored to provide a spectrum of bonding possibilities thereby to obtain desired absorption and desorption characteristics. Disordered hydrogen storage materials having a chemically modified, thermodynamically metastable structure also have a greatly increased density of catalytically active sites for improved hydrogen storage kinetics and increased resistance to poisoning.
[0026] The synergistic combination of selected modifiers incorporated in a selected host matrix provides a degree and quality of structural and chemical modification that stabilizes chemical, physical, and electronic structures and conformations amenable to hydrogen storage.
[0027] The framework for the modified hydrogen storage materials is a lightweight host matrix. The host matrix is structurally modified with selected modifier elements to provide a disordered material with local chemical environments which result in the required hydrogen storage properties.
[0028] Another advantage of the host matrix described by Ovshinsky, et al. is that it can be modified in a substantially continuous range of varying percentages of modifier elements. This ability allows the host matrix to be manipulated by modifiers to tailor-make or engineer hydrogen storage materials with characteristics suitable for particular applications. This is in contrast to multi-component single phase host crystalline materials which generally have a very limited range of stoichiometry available. A continuous range of control of chemical and structural modification of the thermodynamics and kinetics of such crystalline materials therefore is not possible.
[0029] A still further advantage of these disordered hydrogen storage materials is that they are much more resistant to poisoning. As stated before, these materials have a much greater density of catalytically active sites. Thus, a certain number of such sites can be sacrificed to the effects of poisonous species, while the large number of non-poisoned active sites still remain to continue to provide the desired hydrogen storage kinetics.
[0030] Another advantage of these disordered materials is that they can be designed to be mechanically more flexible than single phase crystalline materials. The disordered materials are thus capable of more distortion during expansion and contraction allowing for greater mechanical stability during the absorption and desorption cycles.
[0031] One drawback to these disordered materials is that, in the past, some of the Mg based alloys have been difficult to produce. Particularly those materials that did not form solutions in the melt. Also, the most promising materials (i.e. magnesium based materials) were extremely difficult to make in bulk form. That is, while thin-film sputtering techniques could make small quantities of these disordered alloys, there was no bulk preparation technique.
[0032] Then in the mid 1980's, two groups developed mechanical alloying techniques to produce bulk disordered magnesium alloy hydrogen storage materials. Mechanical alloying was found to facilitate the alloying of elements with vastly different vapor pressures and melting points (such as Mg with Fe or Ti etc.), especially when no stable intermetallic phases exist. Conventional techniques like induction melting have been found to be inadequate for such purposes.
[0033] The first of the two groups was a team of French scientists which investigated mechanical alloying of materials of the Mg—Ni system and their hydrogen storage properties. See Senegas, et al., “Phase Characterization and Hydrogen Diffusion Study in the Mg—Ni—H System”, Journal of the Less-Common Metals, Vol. 129, 1987, pp. 317-326 (binary mechanical alloys of Mg and Ni incorporating 0, 10, 25 and 55 wt. % Ni); and also, Song, et al. “Hydriding and Dehydriding Characteristics of Mechanically Alloyed Mixtures Mg−wt. % Ni (x=5, 10, 25 and 55)”, Journal of the Less-Common Metals, Vol. 131, 1987, pp. 71-79 (binary mechanical alloys of Mg and Ni incorporating 5, 10, 25 and 55 wt. % Ni).
[0034] The second of the two groups was a team of Russian scientists which investigated the hydrogen storage properties of binary mechanical alloys of magnesium and other metals. See Ivanov, et al., “Mechanical Alloys of Magnesium—New Materials For Hydrogen Energy”, Doklady Physical Chemistry (English Translation) vol. 286:1-3, 1986, pp. 55-57, (binary mechanical alloys of Mg with Ni, Ce, Nb, Ti, Fe, Co, Si and C); also, Ivanov, et al. “Magnesium Mechanical Alloys for Hydrogen Storage”, Journal of the Less-Common Metals, vol. 131, 1987, pp. 25-29 (binary mechanical alloys of Mg with Ni, Fe, Co, Nb and Ti); and Stepanov, et al., “Hydriding Properties of Mechanical Alloys of Mg—Ni”, Journal of the Less-Common Metals, vol. 131, 1987, pp. 89-97 (binary mechanical alloys of the Mg—Ni system). See also the collaborative work between the French and Russian groups, Konstanchuk, et al., “The Hydriding Properties of a Mechanical Alloy With Composition Mg-25% Fe”, Journal of the Less-Common Metals, vol. 131,1987, pp. 181-189 (binary mechanical alloy of Mg and 25 wt. % Fe).
[0035] Later, in the late 1980's and early 1990's, a Bulgarian group of scientists (sometimes in collaboration with the Russian group of scientists) investigated the hydrogen storage properties of mechanical alloys of magnesium and metal oxides. See Khrussanova, et al., “Hydriding Kinetics of Mixtures Containing Some 3d-Transition Metal Oxides and Magnesium”, Zeitschrift fur Physikalische Chemie Neue Folge, Munchen, vol. 164, 1989, pp. 1261-1266 (comparing binary mixtures and mechanical alloys of Mg with TiO 2 , V 2 O 5 , and Cr 2 O 3 ); and Peshev, et al., “Surface Composition of Mg—TiO 2 Mixtures for Hydrogen Storage, Prepared by Different Methods”, Materials Research Bulletin, vol. 24, 1989, pp. 207-212 (comparing conventional mixtures and mechanical alloys of Mg and TiO 2 ). See also, Khrussanova, et al., “On the Hydriding of a Mechanically Alloyed Mg(90%)—V 2 O 5 (10%) Mixture”, International Journal of Hydrogen Energy, vol. 15, No. 11, 1990, pp. 799-805 (investigating the hydrogen storage properties of a binary mechanical alloy of Mg and V 2 O 5 ); and Khrussanova, et al., “Hydriding of Mechanically Alloyed Mixtures of Magnesium With MnO 2 , Fe 2 O 3 , and NiO”, Materials Research Bulletin, vol. 26, 1991, pp. 561-567 (investigating the hydrogen storage properties of a binary mechanical alloys of Mg with and MnO 2 , Fe 2 O 3 , and NiO). Finally, see also, Khrussanova, et al., “The Effect of the d-Electron Concentration on the Absorption Capacity of Some Systems for Hydrogen Storage”, Materials Research Bulletin, vol. 26, 1991, pp. 1291-1298 (investigating d-electron concentration effects on the hydrogen storage properties of materials, including mechanical alloys of Mg and 3-d metal oxides); and Mitov, et al., “A Mossbauer Study of a Hydrided Mechanically Alloyed Mixture of Magnesium and Iron(III) Oxide”, Materials Research Bulletin, vol. 27, 1992, pp. 905-910 (Investigating the hydrogen storage properties of a binary mechanical alloy of Mg and Fe 2 O 3 ).
[0036] More recently, a group of Chinese scientists have investigated the hydrogen storage properties of some mechanical alloys of Mg with other metals. See, Yang, et al., “The Thermal Stability of Amorphous Hydride Mg 50 Ni 50 H 54 and Mg 30 Ni 70 H 45 ” , Zeitschrift fur Physikalische Chemie, Munchen, vol. 183, 1994, pp. 141-147 (Investigating the hydrogen storage properties of the mechanical alloys Mg 50 Ni 50 and Mg 30 Ni 70 ); and Lei, et al., “Electrochemical Behavior of Some Mechanically Alloyed Mg—Ni-based Amorphous Hydrogen Storage Alloys”, Zeitschrift fur Physikalische Chemie, Munchen, vol. 183,1994, pp. 379-384 (investigating the electrochemical [i,.e Ni—MH battery] properties of some mechanical alloys of Mg—Ni with Co, Si, Al, and Co—Si).
[0037] Short-range, or local, order is elaborated on in U.S. Pat. No. 4,520,039 to Ovshinsky, entitled Compositionally Varied Materials and Method for Synthesizing the Materials, the contents of which are incorporated by reference. This patent disclosed that disordered materials do not require any periodic local order and how spatial and orientational placement of similar or dissimilar atoms or groups of atoms is possible with such increased precision and control of the local configurations that it is possible to produce qualitatively new phenomena. In addition, this patent discusses that the atoms used need not be restricted to “d band” or “f band” atoms, but can be any atom in which the controlled aspects of the interaction with the local environment and/or orbital overlap plays a significant role physically, electronically, or chemically so as to affect physical properties and hence the functions of the materials. The elements of these materials offer a variety of bonding possibilities due to the multidirectionality of d-orbitals. The multidirectionality (“porcupine effect”) of d-orbitals provides for a tremendous increase in density and hence active storage sites. These techniques result in means of synthesizing new materials which are disordered in several different senses simultaneously.
[0038] Ovshinsky had previously shown that the number of surface sites could be significantly increased by making an amorphous film in which the bulk thereof resembled the surface of the desired relatively pure materials. Ovshinsky also utilized multiple elements to provide additional bonding and local environmental order which allowed the material to attain the required electrochemical characteristics. As Ovshinsky explained in Principles and Applications of Amorphicity, Structural Change, and Optical Information Encoding, 42 Journal De Physique at C4-1096 (October 1981):
Amorphicity is a generic term referring to lack of X-ray diffraction evidence of long-range periodicity and is not a sufficient description of a material. To understand amorphous materials, there are several important factors to be considered: the type of chemical bonding, the number of bonds generated by the local order, that is its coordination, and the influence of the entire local environment, both chemical and geometrical, upon the resulting varied configurations. Amorphicity is not determined by random packing of atoms viewed as hard spheres nor is the amorphous solid merely a host with atoms imbedded at random. Amorphous materials should be viewed as being composed of an interactive matrix whose electronic configurations are generated by free energy forces and they can be specifically defined by the chemical nature and coordination of the constituent atoms. Utilizing multi-orbital elements and various preparation techniques, one can outwit the normal relaxations that reflect equilibrium conditions and, due to the three-dimensional freedom of the amorphous state, make entirely new types of amorphous materials—chemically modified materials . . .
[0040] Once amorphicity was understood as a means of introducing surface sites in a film, it was possible to produce “disorder” that takes into account the entire spectrum of effects such as porosity, topology, crystallites, characteristics of sites, and distances between sites. Thus, rather than searching for material changes that would yield ordered materials having a maximum number of accidently occurring surface bonding and surface irregularities, Ovshinsky and his team at ECD began constructing “disordered” materials where the desired irregularities were tailor made. See, U.S. Pat. No. 4,623,597, the disclosure of which is incorporated by reference.
[0041] The term “disordered”, as used herein to refer to electrochemical electrode materials, corresponds to the meaning of the term as used in the literature, such as the following:
A disordered semiconductor can exist in several structural states. This structural factor constitutes a new variable with which the physical properties of the [material] . . . can be controlled. Furthermore, structural disorder opens up the possibility to prepare in a metastable state new compositions and mixtures that far exceed the limits of thermodynamic equilibrium. Hence, we note the following as a further distinguishing feature. In many disordered [materials] . . . it is possible to control the short-range order parameter and thereby achieve drastic changes in the physical properties of these materials, including forcing new coordination numbers for elements . . .
[0043] S. R. Ovshinsky, The Shape of Disorder, 32 Journal of Non-Crystalline Solids at 22 (1979) (emphasis added).
[0044] The “short-range order” of these disordered materials are further explained by Ovshinsky in The Chemical Basis of Amorphicity: Structure and Function, 26:8-9 Rev. Roum. Phys. at 893-903 (1981):
[S]hort-range order is not conserved . . . Indeed, when crystalline symmetry is destroyed, it becomes impossible to retain the same short-range order. The reason for this is that the short-range order is controlled by the force fields of the electron orbitals therefore the environment must be fundamentally different in corresponding crystalline and amorphous solids. In other words, it is the interaction of the local chemical bonds with their surrounding environment which determines the electrical, chemical, and physical properties of the material, and these can never be the same in amorphous materials as they are in crystalline materials . . . The orbital relationships that can exist in three-dimensional space in amorphous but not crystalline materials are the basis for new geometries, many of which are inherently anti-crystalline in nature. Distortion of bonds and displacement of atoms can be an adequate reason to cause amorphicity in single component materials. But to sufficiently understand the amorphicity, one must understand the three-dimensional relationships inherent in the amorphous state, for it is they which generate internal topology incompatible with the translational symmetry of the crystalline lattice . . . What is important in the amorphous state is the fact that one can make an infinity of materials that do not have any crystalline counterparts, and that even the ones that do are similar primarily in chemical composition. The spatial and energetic relationships of these atoms can be entirely different in the amorphous and crystalline forms, even though their chemical elements can be the same . . .
[0046] Based on these principles of disordered materials, described above, three families of extremely efficient electrochemical hydrogen storage negative electrode materials were formulated. These families of negative electrode materials, individually and collectively, will be referred to hereinafter as “Ovonic.” One of the families is the La—Ni-type negative electrode materials which have recently been heavily modified through the addition of rare earth elements such as Ce, Pr, and Nd and other metals such as Mn, Al, and Co to become disordered multicomponent alloys, i.e., “Ovonic”. The second of these families is the Ti—Ni-type negative electrode materials which were introduced and developed by the assignee of the subject invention and have been heavily modified through the addition of transition metals such as Zr and V and other metallic modifier elements such as Mn, Cr, Al, Fe, etc. to be disordered, multicomponent alloys, i.e., “Ovonic.” The third of these families are the disordered, multicomponent MgNi-type negative electrode materials described in U.S. Pat. Nos. 5,506,069; 5,616,432; and 5,554,456 (the disclosures of which are hereby incorporated by reference).
[0047] Based on the principles expressed in Ovshinsky's '597 Patent, the Ovonic Ti—V—Zr—Ni type active materials are disclosed in U.S. Pat. No. 4,551,400 to Sapru, Fetcenko, et al. (“the '400 Patent”), the disclosure of which is incorporated by reference. This second family of Ovonic materials reversibly form hydrides in order to store hydrogen. All the materials used in the '400 Patent utilize a Ti—V—Ni composition, where at least Ti, V, and Ni are present with at least one or more of Cr, Zr, and Al. The materials of the '400 Patent are generally multiphase polycrystalline materials, which may contain, but are not limited to, one or more phases of Ti—V—Zr—Ni material with C.sub. 14 and C.sub. 15 type crystal structures. Other Ovonic Ti—V—Zr—Ni alloys are described in commonly assigned U.S. Pat. No. 4,728,586 (“the '586 Patent”), titled Enhanced Charge Retention Electrochemical Hydrogen Storage Alloys and an Enhanced Charge Retention Electrochemical Cell, the disclosure of which is incorporated by reference.
[0048] The characteristic surface roughness of the metal electrolyte interface is a result of the disordered nature of the material as disclosed in commonly assigned U.S. Pat. No. 4,716,088 to Reichman, Venkatesan, Fetcenko, Jeffries, Stahl, and Bennet, the disclosure of which is incorporated by reference. Since all of the constituent elements, as well as many alloys and phases thereof, are present throughout the metal, they are also represented at the surfaces and at cracks which form in the metal/electrolyte interface. Thus, the characteristic surface roughness is descriptive of the interaction of the physical and chemical properties of the host metals as well as of the alloys and crystallographic phases of the alloys, in an alkaline environment. The microscopic chemical, physical, and crystallographic parameters of the individual phases within the hydrogen storage alloy material are important in determining its macroscopic electrochemical characteristics.
[0049] In addition to the physical nature of its roughened surface, it has been observed that V—Ti—Zr—Ni type alloys tend to reach a steady state surface condition and particle size. This steady state surface condition is characterized by a relatively high concentration of metallic nickel. These observations are consistent with a relatively high rate of removal through precipitation of the oxides of titanium and zirconium from the surface and a much lower rate of nickel solubilization. The resultant surface has a higher concentration of nickel than would be expected from the bulk composition of the negative hydrogen storage electrode. Nickel in the metallic state is electrically conductive and catalytic, imparting these properties to the surface. As a result, the surface of the negative hydrogen storage electrode is more catalytic and conductive than if the surface contained a higher concentration of insulating oxides.
[0050] The surface of the negative electrode, which has a conductive and catalytic component—the metallic nickel—interacts with metal hydride alloys in catalyzing the electrochemical charge and discharge reaction steps, as well as promoting fast gas recombination.
[0051] Finally, in U.S. Pat. Nos. 5,616,432 ('432 patent) inventors of Ovonic Battery Company produced Mg—Ni—Co—Mn alloys similar to the base alloys of the present inventive composite hydrogen storage material. The storage capacity of these alloys was limited to about 2.7 weight percent and none of the stored hydrogen was desorbed from the alloy at 30° C. FIG. 1 plots the PCT curve of the '432 patents thin film alloy (reference symbol Δ) with that of the present composite hydrogen storage material (reference symbol ♦). As can be seen, the hydrogen storage composite materials of the present invention adsorb more than 4 weight percent of hydrogen, and what is even more remarkable is that this hydrogen can be desorbed at a temperature of 30° C.
[0052] Thus until the advent of the present invention, no prior art material was capable of simultaneously meeting the desired material properties of: 1) a high hydrogen storage capacity; 2) light weight materials; 3)adequate hydrogen absorption/desorption temperatures; 4) adequate absorption/desorption pressures; 5) fast absorption kinetics; and 6) a long absorption/desorption cycle life, all in an inexpensive and easy to produce material.
SUMMARY OF THE INVENTION
[0053] The present invention is a Mg—Ni composite material having an Mg—Ni based alloy; and a coating of a catalytically active metal deposited on at least a portion of a surface of the Mg—Ni based alloy. The coating is less than about 200 angstroms thick and the composite material provides for a storage capacity of up to 4.86 weight percent hydrogen with a high adsorption rate at temperatures as low as 30° C. and an absorption pressure of less than about 150 PSI. More remarkably, the composite materials also have the ability to fully desorb the stored hydrogen at temperatures as low as 250° C., an ability not heretofore seen in materials with such a high total storage capacity. Even more amazingly the same material can desorb 2.51 weight percent of the stored hydrogen at 90° C. and 1.2 weight percent at 30° C. In addition these material are relatively inexpensive and easy to produce.
[0054] The catalytically active metal deposited on at least a portion of a surface of said Mg—Ni based alloy is more preferably less than about 150 angstroms thick and most preferably less than about 100 angstroms thick. The coating of catalytically active metal is preferably formed from at least one metal selected from the group consisting of iron, palladium, platinum, iridium, gold, and mixtures or alloys thereof. Iron, and palladium are the most preferred catalytic coatings.
[0055] The base alloy preferably has a two phase amorphous structure. The Mg—Ni based alloy has a magnesium content which ranges from 40 to 65 atomic percent of the alloy and more preferably from 45 to 65 atomic percent of the alloy. The nickel content ranges from 25 to 45 atomic percent of the base alloy and preferably the nickel content is from 30 to 40 atomic percent. The Mg—Ni based alloy further contains manganese and cobalt. The cobalt content is between 1 and 10 atomic percent of the alloy and preferably between 2 and 6 atomic percent of the alloy. The manganese content is between 1 and 10 atomic percent of the alloy and preferably between 3 and 8 atomic percent of the alloy.
[0056] The Mg—Ni based alloy may further contain at least one element from the group consisting of Fe, Al, Zr, Zn, Cu, Ag, Cu, B, La, Ru, Re, Li, Cr, Pd, Si, V, Sr Misch Metal and mixtures or alloys thereof incorporated into the alloy in quantities totaling less than about 5 atomic percent of the alloy for all inclusions and each individual element is incorporated into said alloy in quantities less than about 3 atomic percent.
[0057] The Mg—Ni composite material is capable of adsorbing at least 3 weight percent hydrogen at a pressure of less than about 150 PSI and more preferably capable of adsorbing at least 3 weight percent hydrogen at a pressure of less than about 50 PSI. The Mg—Ni composite material absorbs 3 weight percent hydrogen in less than two minutes at 30° C. and absorbs 3.5 weight percent hydrogen in less than 10 minutes at 30° C.
BRIEF DESCRIPTION OF THE FIGURES
[0058] FIG. 1 plots the PCT curve of a prior art thin film alloy with that of the present composite hydrogen storage material, specifically shown is the increased storage capacity at 30 ° C.;
[0059] FIG. 2 depicts the XRD plot and the corresponding hydrogen desorption characteristics of composite materials of the present invention formed by two different processes;
[0060] FIGS. 3A and 3B show cross-sectional micrographs of a melt spun ribbon of a base alloy composition useful for the composite material of the instant invention at 600× and 4000×, respectively;
[0061] FIG. 4 shows another cross section micrograph of a melt spun ribbon of a base alloy composition useful for the composite material of the instant invention at 600×, specifically shown is the desired degree of uniformity of the melt spun ribbon;
[0062] FIG. 5 is a high resolution TEM micrograph of the a base alloy composition useful for the composite material of the present invention, specifically the TEM micrographs reveal some three-dimensional micro-tube structures imbedded in the amorphous bulk;
[0063] FIG. 6 depicts x-ray diffraction plots of different base alloy materials made according to the production process of the instant invention;
[0064] FIGS. 7A and 7B are x-ray diffraction plots of a base alloy of the present invention after melt spinning, but before mechanical alloying and after mechanical alloying respectively;
[0065] FIGS. 8A and 8B are bar graph plots of the amount of hydrogen (in weight percent) desorbed from composite materials produced from alloys of the instant invention coated with various catalytic coatings on the y-axis, versus a different desorption temperatures on the x-axis;
[0066] FIG. 9 is an illustrative drawing of the microstructure of a composite material of the instant invention;
[0067] FIG. 10 plots the amount of hydrogen abortion in the first 90 minutes for composite materials using the base alloys AR003 (52% Mg), AR026 (55% Mg), AR030 (58% Mg), and AR031 (Mg61%);
[0068] FIG. 11 shows the results of cycling a composite material of the instant invention at 200° C., and specifically plots the absorption and desorption capacities versus cycle number;
[0069] FIG. 12 shows absorption curves for a composite material of the instant invention having a base alloy composition of Mg 52 Ni 39 Mn 6 Co 3 with a 100 Angstrom palladium coating thereon at 30° C. and 60° C.;
[0070] FIG. 13 shows the desorption curves for the same material as in FIG. 12 ;
[0071] FIGS. 14 and 15 depict the PCT curves for adsorption and desorption of hydrogen for the material of FIGS. 12 and 13 at 30° C. and 50° C., respectively, specifically these figures show that the hysteresis between the hydrogen adsorption and desorption is low;
[0072] FIG. 16 plots the absorption and desorption pressures of various composite materials of the present invention versus hydrogen content (PCT) measured at 200° C.;
[0073] FIG. 17 plots the absorption and desorption plateau pressures as a function of Mg content of the base alloy for the various composite materials of FIG. 16 ;
[0074] FIG. 18 is an x-ray diffraction graph of base alloy materials of the instant invention and specifically shows how use of a graphite crucible introduces deleterious carbon contaminants into the alloy material;
[0075] FIG. 19 plots hydrogen absorption versus time (hydrogen absorption rates) for sample composite materials of the instant invention which were prepared with and without glove box protection (i.e. protection from oxygen contamination);
[0076] FIG. 20 plots the PCT curves at 90° C. of composite materials having a base alloy of AR003 produced by various alloy grinding techniques;
[0077] FIG. 21 depicts a schematic representation of the surface of a composite material of the present invention, and specifically illustrates the possible detrimental effects of oxygen contamination therein;
[0078] FIG. 22 is a plot of PCT absorption and desorption curves at 90° C. for a composite material of the instant invention having a base alloy of AR046 and for another composite material of the instant invention formed from a AR046 base alloy in which 2 at. % silver was partially substituted for nickel in the base alloy (designated AR055), specifically the silver substituted base alloy exhibits improved hydrogen desorption at 90° C.; and
[0079] FIG. 23 plots the hydrogen absorption versus time (the absorption rate) for various additives added to composite materials of the instant invention produced with AR0025 base alloys.
DETAILED DESCRIPTION OF THE INVENTION
[0080] The Mg—Ni alloy composite materials of the instant invention exhibit, for the first time ever, the ability to store and release significant quantities of hydrogen at temperatures less than about 100° C. with good kinetics. Specifically, the instant composite materials can store greater than about 3 weight percent hydrogen at 30° C. More preferably these materials can store greater than about 3.5 weight percent hydrogen and most preferably they can store more than about 4 weight percent hydrogen at 30° C. The base alloys are produced by melt spinning and mechanical alloying and have an addition of a minute quantity of palladium and/or iron on at least a portion of the surface of the alloy to form the composite. As discussed hereinafter, the conditions of the melt spinning and mechanical alloying of the base alloy play a major role in creating the unique properties of the instant composite materials.
[0081] The preferred composite materials of the instant invention generally contain a base Mg—Ni alloy having a two phase amorphous microstructure. The processes of producing these materials, which will be described herein below, are key to producing Mg—Ni alloys which have this two phase amorphous microstructure. That is, if the processing is not correct, materials with a single phase structure will form. This mixed phase structure has a Mg-rich phase and a Ni-rich phase, the inventors have found that the composite materials that have the best kinetics when the ratio of the Mg-rich phase to Ni-rich phase in the base alloy is high. Specifically, it is believed that the Mg-rich amorphous phase acts as a storage phase and the Ni-rich phase acts as a catalytic phase to disassociate the molecular hydrogen to atomic hydrogen, which is then stored in the Mg-rich phase material. Thus, when making the most preferred materials of the present invention, the processes will preferably avoid the production of a single amorphous phase material. It should be noted that by amorphous, it is meant that the structure is predominantly amorphous. The structure may contain some microcrystalline or nanocrystalline areas and still be considered amorphous. Amorphous portions of the materials will be defined herein as having no long-range order greater than about 20 Angstroms.
[0082] The base alloys of the composite materials of the instant invention comprise mainly magnesium and nickel. Table 1 indicates the alloy designation and nominal compositions for specific examples of the base alloy according to the instant invention. Nominal magnesium content ranges from 40 to 65 atomic percent of the alloy and preferably the magnesium content ranges from 45 to 65 atomic percent of the alloy. The nickel content ranges from 25 to 45 atomic percent of the base alloy and preferably the nickel content is from 30 to 40 atomic percent.
[0083] The base alloy preferably also contains manganese and cobalt in quantities much lower than the content of Mg and Ni. The cobalt content is kept as low as possible to reduce the cost of the alloy, and still produce stable, high storage capacity alloys. With that in mind, the cobalt content is between 1 and 10 atomic percent of the alloy and preferably between 2 and 6 atomic percent. The manganese content is between 1 and 10 atomic percent and preferably between 3 and 8 atomic percent.
[0084] Finally, the alloy may also contain elements which help to enhance achievement and stabilization of the amorphous structure of the base alloy and increase the catalytic activity of the alloy, thereby increasing the kinetics thereof. Such elements may include Fe, Al, Zr, Zn, Cu, Ag, Cu, B, La, Ru, Re, Li, Cr, Pd, Si, V, Sr, Misch Metal and mixtures or alloys thereof . These elements, if present will be in quantities totaling less than about 5 atomic percent, and each individual element will be included less than about 3 atomic percent. Iron is a preferred additive.
[0085] The following describes the basic process of producing the base alloys for the hydrogen storage composite materials of the present invention. One kilogram of raw materials having a ratio of ingredients to produce the desired composition is placed into a boron nitride (BN) crucible within a melt spinning chamber. An additional 50 grams of magnesium is added to compensate evaporative losses of magnesium during melting/spinning. The temperature of crucible is ramped up to 1050° C. within 40 minutes. A boron nitride rod which plugs a hole in the bottom of the crucible is removed and liquid metal is forced out from the bottom of the crucible toward a high speed, water-cooled Be—Cu alloy melt-spinning wheel rotating at a linear speed of about 10 m/sec. The alloy is quenched/solidified when it hits the wheel and the ribbons of alloy material that are formed are collected from the bottom of the chamber. After proper cooling for more than 12 hours, the ribbons and flakes were collected and transferred under a protective argon atmosphere to an attritor (Union Process Model S-1) for mechanical alloying (MA). Two different MA processes were used. The first was a 48 hour continuous grinding in an argon atmosphere without any additives which yielded a mixed microcrystalline and amorphous structure. The average crystallite size was 45 angstrom determined by the full width at half maximum from XRD peaks. The second process used small amount of graphite and heptane as grinding aids. The carbon and heptane help to reduce the amount of alloy powder which sticks to the walls of the attritor and also reduces the oxygen contamination of the alloy material. The grinding time was reduced to only two hours as opposed to the 48 hours of the other method. The resulting mircostructure from this second method is a polycrystalline material with an average crystallite size of 285 angstrom. The XRD of alloy materials from two processes and their corresponding hydrogen desorption characteristics are shown in FIG. 2 . Although the total desorption amounts from both process were the same, the 2 hour mechanically alloyed sample did provide faster desorption kinetics and was more economical to produce. Therefore, the second method is more preferred.
[0086] To produce the composite material of the present invention, powder is discharged from the bottom of the attritor into a sealed container and then transferred to a sifter to classify the powder into various sizes. For the instant examples only powder passing through a 200-mesh screen is used. Powder is pressed onto an expanded Ni-substrate inside a glove box using a 30-ton pneumatic press. The surfaces of the pressed sample are coated with a 100 Å layer of a catalytic metal by thermal evaporation in an Edward Auto 306 evaporator. The composite material sample is then tested in a pressure-concentration-isotherm (PCT) apparatus to determine its gas phase hydrogen absorption/desorption characteristics.
[0087] FIGS. 3A and 3B show cross-sectional SEM micrographs of a melt spun ribbon of a base alloy composition useful for the composite material of the instant invention at 600× and 4000×, respectively. This melt spun ribbon shows gross phase segregation into large crystallites of the two phases within portions of the ribbon. Specifically, in this example, the large crystallites appear on the air side of a melt spun ribbon produced on a chilled roller melt quenching apparatus. This gross segregation presents itself as mottled areas in FIG. 2A and as the snowflake shaped areas in FIG. 3B . FIG. 3B also shows a section of the melt spun ribbon that does not show the growth of large crystallites on the right hand side of the cross section.
[0088] FIG. 4 shows another cross section SEM micrograph of a melt spun ribbon of an alloy composition of the instant invention at 600×. This ribbon shows no sign of the growth of large crystallites of Mg-rich and Ni-rich phases. Thus the parameters of the melt quenching (melt spinning) are important and should be set so that few if any large crystallites are formed when the alloy melt is quenched. The reason for the desire to eliminate the larger crystallites is that the next step in the process of making the base alloy materials is a mechanical grinding/alloying step in which the melt spun ribbon materials are mechanically alloyed for up to 72 hours to produce an amorphous material. The larger the crystallites in the melt. spun ribbon, the longer the mechanical alloying required to destroy these crystallites and form the amorphous microstructure.
[0089] FIG. 5 is a high resolution TEM micrograph of an inventive base alloy of the present invention. The TEM micrograph reveals three-dimensional tube-like structures imbedded in the amorphous bulk. These tube-like structures or micro-tubes have never been reported in the prior art of mechanical alloyed materials. These tube structures are believed to be the product of rolling up of two-dimensional sheets during the mechanical alloying process in the attritor. The morphology of these micro-tubes is similar to the recently found nano-tube structures made from carbon. While the actual function of these micro-tubes and their connection to the material's hydrogen storage capacity is not clear at present time, the inventors believe this special connecting tube structure may have a positive contribution to the bulk hydrogen diffusion since they offer a non-conventional network and may very well act as proton conduction channels in the bulk alloy. It is further believed that the enhanced hydrogen storage of the base alloys of the inventive composite materials may be due to a combination of chemically and physically adsorbed hydrogen. The Mg—Ni micro-tubes appear to contain a degree of porosity which may allow physi-adsorbed hydrogen which would be available (desorbed) at low temperatures. The micro-tubes also contribute an extra degree of disorder to the material of the present invention. In addition to the tube structure discussed above, the electron diffraction pattern of the material also indicates the co-existence of microcrystalline and amorphous regions. It is this special combination of various microstructures that makes the material capable of reversibly storing a considerable amount of hydrogen at relatively low temperatures and low working hydrogen pressures. The micro-tubes appear as an inner core of Ni-rich material surrounded by an outer sheathing of Mg-rich material.
[0090] Different base alloy materials were made according to the production process of the instant invention. X-ray diffraction plots of the different base alloys are shown as curves A-G in FIG. 6 . It is significant to note that, as discussed above, the sample having the most pronounced two-phase amorphous structure (curve D) had the best performance of all the materials (especially desorption kinetics). That is, the material having a dual amorphous phase structure out performed similar alloys having a single amorphous phase. Analysis shows that one of the two separate amorphous components of the dual amorphous phase structure material is enriched in Mg, while the other is enriched in Ni when compared to each other. While not wishing to be bound by theory, it is believed that the Ni-rich component may act as the catalytic phase, while the Mg-rich component may be the storage phase.
[0091] FIGS. 7A and 7B are x-ray diffraction plots of a base alloy (designated AR3-MS425) of the present invention after melt spinning, but before mechanical alloying and after mechanical alloying respectively. As can be seen, the as melt spun material is crystalline having sharp peaks. After mechanical alloying, the material becomes mostly amorphous showing very much widened peaks. FIG. 7B also indicates that a dual amorphous phase material results from the mechanical alloying.
[0092] Comparison of two different methods of alloy preparation using the same chemical composition of the base alloy (one forming a single phase amorphous structure and the other forming a two phase structure) shows some interesting results. A single amorphous phase structure material, having a nominal overall composition of Mg 49 Ni 41 Mn 7 Co 3 (atomic %) was produced. This material (designated AR3-MS420) showed a hydrogen storage capacity of 4.1 wt %. This number is quite good as far as capacity goes, but the kinetics were slow, and to get the final capacity number in a reasonable time, the temperature of the alloy had to be raised to 90° C. While this is greater than the 30° C. in which the dual phase material can adsorb the hydrogen (discussed herein below), it is still far below the 300° C. required by other Mg materials of the prior art. Thus even this single phase material can be useful in situations where heat is available in the 80-100° C. range and kinetics are not critical. In comparison, the two phase material (designated AR3-MS425) had a slightly higher maximum hydrogen storage capacity (4.3%) than the AR3-MS420, but the absorption kinetics are greatly improved. Specifically the entire 4.3% absorption took only a few minutes at 30° C.
[0093] Turning now to another inventive alloy material having a nominal overall composition of Mg 61 Ni 32.5 Mn 3 Co 2 Fe 1.5 (designated AR031), this material had an incredible maximum hydrogen storage capacity of 4.86 wt. % at an amazing temperature of 30° C., and on top of the high storage capacity, the absorption kinetics of the material were quite good, absorbing the hydrogen within a matter of minutes.
[0094] The instant inventors have found that iron seems to be a better catalytic coating than even palladium. That is, while the micro-thin palladium coating greatly enhances the absorption kinetics of the base storage alloy, it does not increase the desorption kinetics as greatly. However, iron increases not only the absorption kinetics but also greatly increases the desorption kinetics as well as reversible desorption capacity. FIG. 8A depicts this increase in reversible desorption capacity. FIG. 8A is a bar graph plot of the amount of hydrogen (in weight percent) desorbed from composite materials produced from the AR031 base alloy (see above) coated with various catalytic coatings on the y-axis, versus a different desorption temperatures on the x-axis. The desorption time is set at four hours in each case. As can be seen, the composite material with the iron coating has the best reversible desorption, i.e. 4.86 weight percent at 250° C. and 2.27 weight percent at 90° C. Furthermore, while iron and palladium are the preferred catalytic material, a broader group comprising iron, palladium, platinum, iridium, gold, and mixtures or alloys thereof is deemed by the inventors to be useful in the instant invention.
[0095] FIG. 8B is a bar graph plot of the amount of hydrogen (in weight percent) desorbed from composite materials produced from either the AR031 base alloy or another alloy AR026 (Mg 55 Ni 36 Mn 6 Co 3 ) coated with various catalytic coatings on the y-axis, versus a different desorption temperatures on the x-axis. Amazingly, these composite materials can reversibly desorb about 1.0 to 1.1 weight percent hydrogen even at temperatures as low as 30° C. This is unheard of for a magnesium based system, and allows for instant startup of hydrogen powered devices (i.e. fuel cells, hydrogen internal combustion engines, etc.) without the need to instantaneously increase the temperature of the hydride storage material to hundreds of degrees.
[0096] The catalytic coating of palladium or iron should be as thin as possible and still produced the desired enhancement of the kinetics of the storage of hydrogen in the base alloy. Preferably the coating is less than about 200 Angstroms and more preferably less than about 150 Angstroms thick and most preferably less than about 100 Angstroms thick. It should be noted that the coated palladium constitutes less than about 0.05% of the composite material and therefore could in no way contribute significantly to the hydrogen storage capacity of the overall material. While, once again, not wishing to be bound by theory, it is believed that the coating acts catalytically to enhance the kinetics of the storage material composite. Also, while the coating was evaporated onto the base alloys of the present invention, it could also have been coated onto the alloys by other techniques such as electroless plating, electrolytic plating or chemical vapor deposition.
[0097] It should be noted that the evaporated coating is on the exterior of the pressed bulk sample and does not coat particles on the interior of the bulk. This may not be the most useful way to add the catalytic coating. FIG. 9 is an illustrative drawing of the microstructure of a composite material of the instant invention as envisioned by the inventors. The bulk base alloy consists of magnesium rich hydrogen storage phases intermixed with nickel rich catalytic phases. On the surface of bulk material is an ultra-thin coating of the added catalytic material (i.e. Pd or Fe, ect.). The ultra-thin coating is most likely not contiguous and is not to scale in this illustrative depiction. In fact, cross-sectional SEM photomicrographs do not show the 100-200 Angstrom catalytic coating at all.
[0098] As alluded to above, the present method of adding the catalytic material layer (evaporation onto the exterior of a pressed bulk base alloy) may not be the best method of adding such catalytic material to the composite. The inventors envision that in addition to coating techniques, other techniques may be used to add catalytic material to the bulk base alloy. For instance, the inventors believe that the addition of catalytic particles, such as catalytic iron nano-particles, to the base alloy during the last minutes of mechanical alloying may embed the particles into the surface of the particles of the base alloy. The particulate coated base alloy may then be sintered causing the iron particles to be distributed throughout the bulk of the composite material. Finally, the inventors theorize that some combination of catalytic coating and distributed catalytic particles may be the best form for the composite materials of the present invention.
[0099] The amount of hydrogen abortion in the first 90 minutes were recorded for AR003 (52% Mg), AR026 (55% Mg), AR030 (58% Mg), and AR031 (Mg61%) and plotted in FIG. 10 . The observed trend is that as the magnesium content increases, the total storage capacity also increases. However, the absorption rate decreases as metal-to-hydrogen bond strength increases with the high Mg content. Therefore, a balance between the amount of hydride former (Mg, for example) and modifier (Ni, Co, etc.) is very important for the general material performance, as well as the proper distribution of these components
[0100] A mechanically alloyed sample of material having the base alloy composition designated AR26 was produced by a two hour grinding with heptane and graphite grinding aids. The base alloy was pressed into an expanded metal substrate and then was coated with 100 angstrom of Fe on both sides. The sample was put into a PCT measurement apparatus and both the hydrogen adsorption and desorption capacity at 200° C. were measured as a function of cycle number. The results of cycling at 200° C. are shown in FIG. 11 which plots the absorption and desorption capacities versus cycle number. From the data, it can be seen that the absorption capacity was not changed (2.8%) while desorption capacity dropped slightly from a maximum of 2.6% to 2.4% after 400 cycles. The 200° C. cycling temperature was chosen to hasten the experimental measurements and does not reflect a restriction of the useful temperature range for the tested sample.
[0101] As alluded to above, the instant composite materials have very good low temperature kinetics. FIG. 12 shows absorption curves for a composite material of the instant invention having a base alloy composition of Mg 52 Ni 39 Mn 6 Co 3 with a 100 Angstrom palladium coating thereon at 30° C. (reference symbol ∘) and 60° C. (reference symbol ▪). The hydrogen absorption occurred at a pressure of 120-150 psi. As can be seen from these curves, this material has very good kinetics (absorbing the majority of the hydrogen in a matter of minutes) at relatively low temperatures and pressures. That is, this composite material can absorb 3 weight percent hydrogen in less than two minutes and 3.5 weight percent hydrogen in less than 10 minutes at 30° C. These are fantastic results which have heretofore never been seen in the prior art. FIG. 13 shows the desorption curves for the same alloy as in FIG. 8 . This figure shows that the material can desorb the stored hydrogen within a matter of minutes at 30° C.
[0102] FIGS. 14 and 15 depict the PCT curves for adsorption and desorption of hydrogen for the material of FIGS. 12 and 13 at 30° C. and 50° C., respectively. Perusal of these figures shows that the hysteresis between the hydrogen adsorption and desorption is low. This can be seen by comparing the pressure differential between the adsorption and desorption curves of the PCT plots at the midpoint of the composition range. The midpoint is the point at about half of the maximum hydrogen storage capacity.
[0103] A series of compositions with Mg contents varying from 42 to 62 atomic % were prepared. The PCT measured at 200° C. for some of the alloys is plotted in FIG. 16 . The plot shows absorption and desorption plateau pressures. The plateau pressure hystersis is large compared to other hydrogen storage materials as Lavas phases based AB 2 , or CaCu 5 -structure AB 5 materials. FIG. 17 plots the absorption and desorption plateau pressures as a function of Mg content of the base alloy for the various composite materials of FIG. 16 . This plot indicates that there is an optimal Mg content at around 55% at which the absorption-desorption hystersis is minimized.
[0104] In addition to the specifics on the melt quenching, the composition of the crucible in which the alloy is melted is important. FIG. 18 is an x-ray diffraction graph of materials of the instant invention and specifically shows how use of a graphite crucible (curves C and D) introduces carbon contaminants into the alloy material. The carbon forms carbides which cannot be made amorphous by mechanical alloying. However, the use of boron nitride crucibles produces contaminants which can be made amorphous by mechanical alloying (see curves A and B). The carbon contaminant is a “malignant” contaminant and as such negatively influences the properties of the composite material, whereas the boron nitride is a “benign” contaminant and does not adversely influence the properties of the hydrogen storage composite. Carbon enters the alloy and takes hydrogen sites and as such the reduction/elimination of carbon contamination allows for the production of materials which have the storage capacity and kinetics of the instant invention.
[0105] The magnetic susceptibility of samples having compositions designated as AR003, AR026, and AR031, which were prepared by grinding with and without the addition of graphite and heptane grinding aids were measured. In both cases, grinding time was two hours. The susceptibility results data was used to determine the free nickel content percentage of the samples. The free nickel content of the samples is listed in Table II. Samples ground with graphite and heptane grinding aids showed higher percentage of free nickel, which contributed to a more catalytic surface, thereby helping hydrogen absorption.
[0106] In the inventors' original attritor setup, an overpressure of argon was maintained in the attritor container throughout the entire mechanical alloying process. Small amount of argon leaked out from the collar holding the rotating shaft of the attritor. The inventors believed that there might have been some air back-streaming into the attritor as a result of this leakage. In an attempt to reduce possible oxygen contamination, the inventors constructed a glove box around the attritor and filled the glove box with an argon atmosphere to protect the attritor. The hydrogen absorption rates for samples prepared with and without glove box protection are shown in FIG. 19 . It can be seen that this added protection was successful in reducing the oxygen contamination of the mechanically alloyed materials. With reduction in oxygen contamination, not only did the total storage capacity increase, but the storage kinetics also increased. The calculated surface reaction and bulk diffusion constant for the two samples are listed in Table III. While the bulk diffusion constant improved by a factor two with the reduction of oxygen contamination, the surface hydrogenation kinetics increased by as much as seven times. This clearly illustrates the importance of oxygen control during processing.
[0107] In an attempt to reduce the grinding time required to make the base alloy powder of the instant invention and thereby the associated cost of production, the inventors used an air stream crushing technique to break up the ribbons of the hydrogen storage alloy. The technique used a high speed air stream impinging upon coarse powder sitting in a cyclone-like container, the powder was pulverized by crushing against each other and the powder was collected from the container through a sieve. The temperature of the impinging air stream is at least 5 to 10° C. lower than environment due to the expansion of the pressurized gas stream. The powder thus obtained was labeled as the air stream sample. A portion of the air stream sample powder was fed into the attritor and ground for two hours with heptane and graphite grinding aids. The PCT curves at 90° C. are plotted in FIG. 20 . A small degradation in the hydrogen capacity is observed on air stream sample due to oxygen in the air used. The inventors believe that the results will be improved if a protective atmosphere such as argon or nitrogen is used instead of air.
[0108] The possible detrimental effects of oxygen contamination are illustrated in FIG. 21 , which depicts a schematic representation of the surface of a composite material of the present invention. The surface oxide formed during powder processing, storage, or transportation will hinder the hydrogen absorption through surface catalysis (region 1 in FIG. 21 ). It will also obstruct hydrogen atoms from recombining into hydrogen molecules at the surface during hydrogen desorption. The second affected area is in the grain boundary (as shown in region 2 in FIG. 21 ). The relatively large size and electron affinity of the oxygen ion in the grain boundary will stop hydrogen diffusion through the dangling bonds in the grain boundary area and thus reduce the bulk diffusion of hydrogen. Both the desorption and absorption kinetics will be diminished substantially. The third negative effect of oxygen is in the bulk region where useful hydrogen storage site are occupied or interfered with by negatively charged oxygen. Therefore the reversible storage capacity of hydrogen will be reduced (region 3 in FIG. 21 ).
[0109] One additional aspect of the present invention which has not been fully discussed, but which is very important, is the equilibrium pressures of the present composite hydrogen storage materials. The pressures used to adsorb the hydrogen into the materials of the present invention are less than 150 PSI. Most of the hydrogen can be adsorbed into the materials at less than about 50 PSI. In contrast, most other work on high capacity Mg based hydrogen storage materials require pressures in the range of 1000-5000 PSI. With this greatly lowered pressure requirement, the requirements for the materials of construction for hydrogen storage beds and like systems is greatly reduced. Thus at 50-150 PSI, light weight simple construction materials may be used (for example rubber tubing as opposed to quarter inch stainless steel tubing may be used) whereas in the range of 1000-5000 PSI, more expensive and exotic materials must be used. This reduction in cost and complexity of related systems and materials of construction are an added benefit of the composite materials of the instant invention.
[0110] One element proven to have positive contribution toward hydrogen desorption is silver. When 2 at. % silver was partially substituted for nickel in the base alloy designated AR046, the resulting alloy (designated AR055) exhibits improved hydrogen desorption at 90° C. as can be seen from two PCT curves illustrated in FIG. 22 . This sample had a desorption plateau pressure of around 0.003 MPa. It is believed that the relatively large atomic size of silver may contribute greatly to disorder of the polycrystalline sample and make the absorbed hydrogen easier to remove from the lattice.
[0111] In an attempt to improve the hydrogen absorption rate of AR025 materials, small amounts of additives (1.5 to 2. wt. %) were added to the base alloy material by a shaker milling method. These catalyst candidates include Cr 2 O 3 , V 2 O 5 , Pd, RuO 2 .xH 2 O, PdO.xH 2 O, MgB 2 , LiBH 4 , and Fe 3 O 4 . The shaker mill was run for 30 minutes to ensure through mixing of the AR026 powder with the additives. The resulting mixture was pressed into an expanded metal substrate and tested in the gas phase reactor. The hydrogen absorption vs. time (absorption rate) for each additive are plotted in FIG. 23 . From FIG. 23 , it can be concluded that both Pd and RuO 2 .xH2O improve hydrogen absorption kinetics substantially while maintain high storage capacity. The PdO.xH 2 O also improves the absorption kinetics but slightly reduces to the total storage capacity.
[0112] Another potential application of these Mg-based hydrogen storage composite materials outside of gas phase storage of hydrogen is in nickel-metal hydride batteries (Ni—MH). A half-cell test configuration was constructed using AR034 as the negative electrode and a partially precharged sintered Ni(OH) 2 electrode as the counter electrode. The system was charged at a rate of 100 mA/g for 12 hour (total capacity input was 1200 mAh/g). Then the system was discharged and the total discharge capacity at the third cycle was 692 mAh/g, which is equivalent to a gas phase hydrogen reversible storage capacity of 2.58%. Thus the electrochemical measurement confirmed the high hydrogen storage potential that was observed from the gas phase measurements.
[0113] The drawings, discussion, descriptions, and examples of this specification are merely illustrative of particular embodiments of the invention and are not meant as limitations upon its practice. It is the following claims, including all equivalents, that define the scope of the invention.
TABLE 1 In Atomic Percent Alloy # Mg Ni Co Mn Fe Al Zr Cu Zn Ag B Other AR1 52 45 3 — — — — — — — — — AR3 52 39 3 6 — — — — — — — — AR4 51.5 37 6 4 1.5 — — — — — — — AR5 50 40 6 3 — — 1 — — — — — AR6 51.5 37 3 4 1.5 3 — — — — — — AR7 51.5 37 6 4 — — — 1.5 — — — — AR8 51.5 37 4 4 — 2 — 1.5 — — — — AR9 51.5 37 4 4 — 2.5 1 — — — — — AR10 51.5 37 4 3 1.5 2 — 1 — — — — AR11 51.5 37 3 3 1 2 1 1.5 — — — — AR12 51.5 37 3 3 1 2 — 1.5 1 — — — AR13 51.5 37 3 3 1.5 3 — — 1 — — — AR14 51.5 37 3 3 1 2 1 — 1.5 — — — AR15 51.5 36 3 3 1 2 1 1.5 1 — — — AR16 51.5 36 4 4 1.5 — — — — — 1 — AR17 51.5 37 3 3 1.5 3 — — — — 1 — AR18 51.5 35 4 4 1.5 — — — — — 2 — AR19 50 35 4 4 3 5 — — — — — — AR20 50 38 6 6 — — — — — — — 3%-La AR21 50 38 6 6 — — — — — — — 3%-Ru AR22 50 38 6 6 — — — — — — — 3%-Re AR23 51.5 33.5 4 4 — — — 5 — — — — AR24 51.5 28.5 4 4 — — — 10 — — — — AR25 51.5 28.5 4 4 3 — — 10 — — — — AR26 55 36 3 6 — — — — — — — — AR27 58 33 3 6 — — — — — — — — AR28 55 36 3 4.5 1.5 — — — — — — — AR29 55 35 3 4.5 1.5 — — — — — 1 — AR30 58 32 3 4.5 1.5 — — — — — 1 — AR31 61 32.5 2 3 1.5 — — — — — — — AR32 61 30 2 4.5 1.5 — — — — — 1 — AR33 55 30 3 12 — — — — — — — — AR34 55 24 3 18 — — — — — — — — AR35 55 29 10 6 — — — — — — — — AR36 55 23 16 6 — — — — — — — — AR37 47 44 3 6 — — — — — — — — AR38 42 49 3 6 — — — — — — — — AR39 51.4 38.6 3 6 — — — — — — — 1%-Li AR40 51.4 38.6 3 6 — — — — — — — 1%-Cr AR41 51.4 38.6 3 6 — — — — — 1 — — AR42 51.4 38.6 3 6 — — — — — — — 1% Pd AR43 55 36 3 5 — 1 — — — — — — AR44 55 36 3 4 — 2 — — — — — — AR45 55 35 3 4 — 2 — — — — 1 — AR46 61 29 2 4.5 1.5 1 — — — — 1 — AR47 61 28 2 4.5 1.5 2 — — — — 1 — AR48 51.5 35 6 4 3.5 — — — — — — — AR49 51.5 34 6 4 3.5 — — — — — 1 — AR50 51.5 32 6 4 3.5 1 — 1 — — 1 — AR51 50 38.5 6 4 1.5 — — — — — — — AR52 48.5 40 6 4 1.5 — — — — — — — AR53 43.4 43.9 3 6 2 — — — — — — Si—Cr—V AR54 51.5 37 6 4 1.5 1 — — — — 1 — AR55 61 27 2 4.5 1.5 1 — — — 2 1 — AR56 61 27 2 4.5 1.5 1 — — — — 1 2%-Sr AR57 61 27 2 4.5 1.5 1 — — — — 1 2%-MM AR58 61 27 2 4.5 1.5 1 — — 2 — 1 — AR59 61 27 2 4.5 1.5 1 2 — — — 1 — AR60 61 27 2 4.5 1.5 1 — 2 — — 1 — AR61 48.5 37 9 4 1.5 — — — — — — — AR62 46.5 42 6 4 1.5 — — — — — — — AR63 44.5 44 6 4 1.5 — — — — — — — AR64 48.5 38.5 6 4 3 — — — — — — — AR65 48.5 36.5 6 4 3 1 — — — — 1 — AR66 48.5 38 6 4 1.5 — — — — — — 2%-V AR67 59 27 2 4.5 1.5 1 — — — 4 1 — AR68 60 27 2 4.5 1.5 1 — — 1 2 1 — AR69 59 27 2 4.5 1.5 1 — — 2 2 1 — AR70 58 27 2 4.5 1.5 1 — — 3 2 1 — AR71 48.5 38 6 4 1.5 — — — — 2 — — AR72 48.5 40 4 4 1.5 — — — — 2 — — AR73 48.5 40 4 4 1.5 — — — 2 — — — AR74 48.5 37 4 4 1.5 — — — 2 2 1 —
[0114]
TABLE II
Without heptane/
With heptane/
Base Alloy #
graphite grinding aids
graphite grinding aids
AR003
0.18%
0.34%
AR026
0.27%
0.49%
AR031
1.79%
2.81%
[0115]
TABLE III
Without glovebox
With glovebox
proctection
proctection
Surface reaction
7 minutes
1 minute
time constant
Bulk Diffusion
5.5 minutes
2.5 minutes
time constant | A hydrogen storage alloy having an atomically engineered microstructure that both physically and chemically absorbs hydrogen. The atomically engineered microstructure has a predominant volume of a first microstructure which provides for chemically absorbed hydrogen and a volume of a second microstructure which provides for physically absorbed hydrogen. The volume of the second microstructure may be at least 5 volume % of atomically engineered microstructure. The atomically engineered microstructure may include porous micro-tubes in which the porosity of the micro-tubes physically absorbs hydrogen. The micro-tubes may be at least 5 volume % of the atomically engineered microstructure. The micro-tubes may provide proton conduction channels within the bulk of the hydrogen storage alloy and the proton conduction channels may be at least 5 volume % of the atomically engineered microstructure. | 8 |
FIELD OF THE INVENTION
[0001] The field of this invention is a releasing system for downhole packers and more particularly, a system where the release mechanism is protected from accidental release and damage from flowing fluids.
BACKGROUND OF THE INVENTION
[0002] In the past, downhole packers were released in three different ways. Dogs were unsupported to let the body be extended for release. Collets became unsupported to have the same effect. Finally, the packer could be cut downhole to allow release. FIGS. 1 a - 1 c illustrate a prior art mechanically set packer with a collet release system. A setting tool (not shown) pushes down on setting sleeve 10 while pulling up on the top sub 12 of mandrel 14 . The setting sleeve 10 pushes down on the sealing elements 16 , the upper cone 18 and the slips 20 , while the mandrel 14 , through collets 22 , pulls up on the lower cone 24 . The set position is held by body lock ring 26 , which works like a ratchet to keep the set packer from relaxing. As seen in FIGS. 1 c and 2 , a support sleeve 28 is held on to the collets 22 by shear pins 30 . In the position shown in FIG. 1 c the support sleeve transmits the upward pull force from the top sub 12 to the lower cone 24 during the setting procedure. To release the packer, a release tool (not shown) is run downhole to engage the support sleeve 28 and pick it up so as to break shear pins 30 and to undermine the contact between the collets 22 and bottom sub 32 (see FIG. 3). The releasing tool brings up the support sleeve 28 against the mandrel 14 to allow the slips 20 to be undermined as the upper cone 18 is pulled out from under them. In a similar manner, the elements 16 are allowed to relax.
[0003] In a similar manner, the prior art design of FIGS. 5 and 6 operated to allow the packer to set and, later, to release, when a release tool (not shown) moved up release sleeve 34 undermining the segmented dogs 36 for a release from the bottom sub 38 . These structures were also used with hudraulically set packers.
[0004] The potential problem with these designs is the exposed placement of the support sleeve 28 or the release sleeve 34 . Lowing well fluids can cause damage due to erosion or corrosion. Additionally, tools are frequently run through such packers to actuate other devices below the packer. These tools could, inadvertently, engage the support sleeve 28 or the release sleeve 34 and trigger a release of the packer. This problem could be avoided with another known design which requires the packer to be cut loose after being set downhole. This technique is complicated and requires very experienced personnel to perform the operation. This technique also generates cuttings which can be left in the well and the packer is destroyed in the process, preventing reuse.
[0005] The present invention presents a unique mechanism for release which overcomes the drawbacks of the prior art as described above. The release mechanism is minimally exposed to the wellbore to give it protection from well fluid attack and accidental release from contact by other tools. Additionally, the packer is simply released and can be reused. These and other advantages of the present invention will be more readily understood from a review of the description of the preferred embodiment, which appears below. Other known packer release designs are illustrated in U.S. Pat. Nos: 3,311,171; 3,361,207; 3,976,133; 4,216,827; 4,436,150; 4,518,037; 4,565,247; 4,664,188; 5,333,65; 5,718,291; and 5,787,982.
SUMMARY OF THE INVENTION
[0006] A release system for a packer is disclosed. The release ring is minimally exposed in the wellbore and is actuated by a release tool, which comprises a collet and cone with a relative movement feature. In the preferred embodiment, the release ring has alternating cuts and a built in radially outward bias. The ring is held in locked position by bands, which are broken by the action of the releasing tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIGS. 1 a - 1 c are a sectional elevation of a prior art tool using collet release, shown in the run in position;
[0008] [0008]FIG. 2 is a detailed view of the collet release system shown in prior art FIG. 1 c, shown it the set position for the packer;
[0009] [0009]FIG. 3 is the view of the prior art tool shown in FIG. 2, but shown in the released position;
[0010] [0010]FIG. 4 is an alternative prior art design of a releasing assembly, shown in the set position;
[0011] [0011]FIG. 5 is the view of FIG. 4 shown in the released position;
[0012] [0012]FIG. 6 is one embodiment of the present invention, shown in section, just prior to release with the releasing tool;
[0013] [0013]FIG. 7 is the view of FIG. 6 in the released position;
[0014] [0014]FIG. 8 is a section view of the release ring of the preferred embodiment of the invention;
[0015] [0015]FIG. 9 is a view along lines 9 - 9 of FIG. 8;
[0016] [0016]FIG. 10 is a view along lines 10 - 10 of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] In a first embodiment of the invention, shown in FIG. 6, the pickup force to set the packer is transmitted from sleeve 40 to sleeve 42 through release ring 44 . It should be noted that FIG. 6 illustrates the same area of the packer as FIGS. 2 - 5 but it represents one embodiment of the present invention to replace those prior art assemblies. Ultimately, sleeve 42 is connected to bottom sub 46 in an area off the right side of FIG. 6. Bottom sub 46 exerts an upward force on the lower cone to help set the slips and the element in the manner described for the prior art devices. What is different is how the setting force is transmitted and how the set is later released. In FIG. 6, the release ring is made of independent segments each having a tab 48 , which extends into groove 50 of sleeve 40 . A matching tooth or serration or other engagement pattern 52 helps retain the release ring 44 to the sleeve 40 . Similarly, a similar structure 54 helps retain the sleeve 42 to the release ring 44 . Initially, bolts 56 hold sleeve 40 to release ring 44 and bolts 58 retain the release ring 44 to sleeve 42 . In FIG. 6, the retrieving tool is in position but has not yet been actuated. The retrieving tool R has a movable cone 60 adjacent a series of collets 62 . When the retrieving tool R is actuated, the cone 60 moves relatively to the collets 62 pushing the collet heads 64 against surface 66 of release ring 44 . There is a clearance space 68 , which closes up as the release ring 44 has its segments pushed outwardly.
[0018] As shown in FIG. 7, actuation of the releasing tool R disengages the engagement patterns 52 and 54 but tab 48 is still in groove 50 . Because the tab 48 is still engaged in groove 50 , the segments that make up the release ring 44 remain connected to sleeve 40 and do not fall to the bottom of the wellbore. The release of the engagement patterns 52 and 54 allows the packer to be stretched out and retrieved in the known manner, using the retrieval tool R. Those skilled in the art will appreciate that each segment of release ring 44 has two bolts 52 and 54 to initially secure the engagement patterns 52 and 54 which are on it, respectively to sleeves 40 and 42 . As shown in FIG. 6, surface 66 is flush in the passage 70 leaving it less likely to be actuated by tools going further downhole to operate other equipment. The limited exposed area of surface 66 further reduces the potential harmful effects from erosion or corrosion from passing well fluids. The engagement patterns 52 and 54 are completely out of the main flowpath. Additional seals can be optionally added to fully isolate the engagement patterns 52 and 54 from the moving well fluids. Once the packer is removed, it can be redressed for further use by putting the components back together as shown in FIG. 6.
[0019] The preferred embodiment is shown in FIGS. 8 - 10 . In this version the release ring 44 ′ takes the place of the segments that made up release ring 44 . Engagement patterns 52 ′ and 54 ′ are still used with the release ring 44 ′. Rather than being segments, release ring 44 ′ is a cylinder having alternating longitudinal notches 72 and 74 which begin, respectively, at opposite ends 76 and 78 of release ring 44 ′. An outward radial bias is built into release ring 44 ′ toward the clearance space 68 (see FIG. 6), when release ring 44 ′ is used in lieu of the segments that make up release ring 44 . Overlaying the release ring 44 ′ are bands 80 and 82 to urge radial inward movement against a spreading force by the retrieval tool R against surface 66 ′. The use of the bands 80 and 82 allows tab 48 and groove 50 , used of segments that made up release ring 44 to be eliminated in the preferred design of release ring 44 ′. In other respects, the operation of the two embodiments of the invention are the same.
[0020] Those skilled in the art will appreciate that both embodiments of the invention described above present a minimal area in the passage 70 for the release mechanism. The flush mounting reduces the chance of an accidental release and minimizes the erosive and corrosive effects of flowing fluids. The size of the passage 70 can be maximized. The engagement patterns, such as 52 ′ and 54 ′, can be isolated from fluids flowing through passage 70 . Minor impingements on to surface 66 ′ are unlikely to actuate a release. Use of the flush mounted surface 66 ′ makes it simpler to release, when that operation is desired, than even the design shown in FIGS. 6 and 7 and certainly release is easier than the prior art techniques illustrated in FIGS. 2 - 5 . Surface 66 ′ can also be slightly recessed. This makes it easier to properly locate the releasing tool R.
[0021] The above description of the preferred embodiment is merely illustrative of the optimal way of practicing the invention and various modifications in form, size, material or placement of the components can be made within the scope of the invention defined by the claims below. | A release system for a packer is disclosed. The release ring is minimally exposed in the wellbore and is actuated by a release tool, which comprises a collet and cone with a relative movement feature. In the preferred embodiment, the release ring has alternating cuts and a built in radially outward bias. The ring is held in locked position by bands, which are broken by the action of the releasing tool. | 4 |
This is a continuation of application Ser. No. 07/672,261 filed on Mar. 20, 1991, now abandoned.
BACKGROUND OF THE INVENTION
The subject matter of the present invention essentially is an elastic and compressible printing element, this element constituting what is called a blanket which may be secured onto the surface of cylinders which are provided in the printing machines.
Most of the printing blankets presently used in the printing machines essentially comprise a lithographic layer allowing the transfer of information from the blanket-carrying cylinder onto a web of paper and a compressible structure consisting of a layer of cellular rubber placed in sandwich-like relationship between two fabric layers.
Now the compressibility of such a blanket, i.e. its possibility of becoming deformed under the effect of a force exerted by the machine upon the blanket-carrying cylinder bearing onto another blanket-carrying cylinder for instance remains limited. Therefore a relatively great force should be exerted upon the blanket and this force will result with time in a sagging of the blanket which will no longer recover its initial thickness and geometry. Moreover it should be noted that in the modern quick-operating printing machines heatings promoting the sagging of the blanket will occur and of course the quality of impression of the paper web passing between both blanket-carrying cylinders and the travelling of this web will be strongly affected.
Moreover with such blankets which are not very compressible and which generate high pressures for a given nip between both blanket-carrying cylinders there are substantial risks of shearing. More specifically the material which constitutes the blanket tends to move sidewise to form in a way protrusions which is highly harmful to the quality of impression of the web of paper and to the proper travelling of this web.
There has also been proposed in the document FR-A-2,461,596 a blanket essentially comprising a lithographic layer, a layer of cellular rubber and a stabilizing or base layer consisting of several layers of fabric bonded with neoprene.
Here again however such a blanket is likely to generate high pressures in the nip between both cylinders carrying the blankets whereas this should be avoided so as to not impair the structure of the blanket and such a blanket may also incur risks of shearing, i.e. of sidewise displacement of the material of the blanket which leads to the inconveniences mentioned above.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to cope with all these inconveniences by proposing a blanket which will have no tendency when compressed to induce sidewise displacement of the material which constitutes it so that the quality of impression and the travelling of the paper web will remain satisfactory and which will always exhibit a dynamic neutral behaviour under the effect of a compression force.
For that purpose the subject matter of the invention is an elastic and compressible printing element of the type comprising a lithographic or printing layer with which is associated a structure with compressible layers, characterized in that the said structure consists of at least one layer of fabric or the like placed in sandwich-like fashion between two layers of cellular rubber having identical or different compressibility properties.
According to a preferred embodiment the layer of cellular rubber located towards the lithographic layer has a modulus of elasticity in compression higher than the other layer of cellular rubber.
According to another characterizing feature of the invention with the layer having a lower modulus of elasticity is associated a base layer of fabric or other reinforcing material.
According to another embodiment the layer with a lower modulus of elasticity itself constitutes the base layer.
The elastic and compressible printing element according to this invention further comprises a hard layer of elastomer possibly reinforced which is interposed between the lithographic layer and the layer of cellular rubber nearest to this lithographic layer.
According to another characterizing feature of the invention the thickness of the layer of fabric or the like is lying between about 0.1 and 1 mm and the thicknesses of both layers of cellular rubber are each one lying between 0.1 and 0.8 mm.
According to a preferred embodiment the thickness of the layer of fabric or the like is 0.35 mm, the thickness of the cellular layer with a lower modulus of elasticity is 0.5 mm and the layer of cellular rubber with a higher modulus of elasticity is 0.45 mm.
It should further be specified here that the thickness of the aforesaid hard layer of elastomer is lying between about 0.5 and 0.05 mm and preferably is equal to 0.15 mm.
According to still another characterizing feature of the printing element according to this invention both aforesaid layers of cellular rubber have a modulus of elasticity lying between about 0.2 and 50 megapascals (MPa) for the layer with a higher modulus of elasticity and between about 0.1 and 25 MPa for the layer with a lower elasticity.
According to a preferred embodiment the modulus of elasticity of the layer of cellular rubber located towards the lithographic layer is 10 MPa whereas the modulus of elasticity of the other layer of cellular rubber is 5 MPa.
It should further be specified here that the percentage of gas volume enclosed within both layers of cellular rubber, preferably within closed cells is lying between about 10 and 80% and preferably is equal to 30% for the layer with the higher modulus of elasticity and to 35% fop the layer with a lower modulus of elasticity.
The invention is also directed to the cylinders fitted with a printing blanket element meeting the characteristics referred to hereinabove.
DESCRIPTION OF THE DRAWINGS
Now further characteristics and advantages of the invention will appear better in the detailed description which follows and refers to the annexed drawings given by way of example only and wherein:
FIG. 1 is an enlarged sectional view of a printing blanket according to the invention;
FIG. 2 is an enlarged sectional view of another embodiment of the blanket according to this invention:
FIG. 3 diagrammatically and partially illustrates two blankets according to this invention in the compressed state and carried by two cylinders, respectively, between which passes a paper web, the whole being plotted in a reference system with orthogonal axes of coordinates where the axis of the abscissae coincides with the direction of the paper web and wherein the axis of ordinates intersects the axis of abscissae at the center of the compressed area of both blankets;
FIG. 4 shows three curves illustrating in millimeters the sidewise displacement of the material constituting the blanket on either side of the center O of the compression area--a deformation visible on FIG. 3, versus the distance from this point O and along the axis of abscissae OX on FIG. 3, these three curves respectively corresponding to a blanket such as currently used presently and which will be hereinafter called the prior art blanket, to a blanket according to the document FR-A-2,461,596 and to a blanket according to the invention; and
FIG. 5 still shows three curves illustrating the relative pressure in the gap between blankets for the three blankets referred to hereinabove versus the position on the axis of the abscissae OX with respect to the center O of the pressure area.
DETAILED DESCRIPTION OF THE INVENTION
According to the examplary embodiment shown on FIG. 1 an elastic and compressible element or printing blanket according to this invention successively comprises an outer lithographic or printing layer 1, a hard layer of elastomer 2, a layer of cellular rubber 3, a layer of fabric or the like 4 and another layer 5 of cellular rubber.
In the alternative embodiment shown on FIG. 2 there are found in the same order the layers 1 to 5 mentioned hereinabove but here the blanket in addition comprises a base layer 6 of fabric or other suitable reinforcing material.
When securing the blanket onto a cylinder (not shown) the base layer 6 should be applied onto the peripheral surface of this cylinder whereas in the case of the blanket of FIG. 1 the base layer applied onto the cylinder is constituted by the layer of cellular rubber 5.
In both embodiments shown in FIGS. 1 and 2 the layers of cellular rubber 3 and 5 may be identical or different with respect in particular to their moduli of elasticity.
Preferably the layer 3 located towards the lithographic layer 1 should have a higher modulus of elasticity in compression lying between about 0.2 and 5O MPa whereas the layer 5 forming the base layer (FIG. 1) or associated with the base layer 6 (FIG. 2) should have a lower modulus of elasticity lying between about 0.1 and 25 MPa. Thus the modulus of elasticity of the layer 3 may be equal to 10 MPa and the modulus of elasticity in compression of the other layer 5 of cellular rubber could be equal to 5 MPa.
It should be noted here that the difference in the moduli of elasticity between both layers of cellular rubber 3 and 5 could be obtained by a variation in the percentage of gas volume enclosed within both layers, preferably within closed cells as diagrammatically shown on the Figures. Thus the percentage in question could be equal to 30% for the layer 3 with the higher modulus of elasticity and to 35% for the layer 5 with a lower modulus of elasticity.
As to the thicknesses of both layers of cellular rubber 3 and 5 they may lie each one between 0.1 and 0.8 mm. It is thus possible to provide a thickness of 0.45 mm for the layer 3 and a thickness of 0.5 mm for the layer 5.
The thickness of the layer of fabric or the like 4 held in sandwich-like fashion between both layers of cellular rubber 3 and 5 could lie between about 0.1 and 1 mm and be for instance equal to 0.35 mm.
As to the thickness of the layer 2 of hard elastomer it should lie between about 0.5 and 0.05 mm and will preferably be equal to 0.15 mm.
Now for a better understanding of the invention the outstanding interest and advantages of the blanket of the invention as compared with a prior art blanket, i.e. a blanket of the kind currently used nowadays and with a blanket according to the document FR-A-2,461,596 will be explained hereinafter.
Reference should be had to the Table which follows and which indicates the various layers of the three blankets referred to hereinabove and for which has been adopted a same thickness so that the results be comparable.
______________________________________BLANKETThicknesses Document(mm) Invention Prior Art FR-A-2,461,596______________________________________0.2 Lithographic Lithographic Lithographic layer layer layer0.15 Hard layer Hard layer Hard layer0.45 Cellular Fabric Cellular rubber rubber0.35 Fabric Cellular Base rubber layer0.5 Cellular Fabric (fabric + rubber neoprene)0.35 Base layer Base layer (fabric) (fabric)______________________________________
More specifically it is seen on this Table from the left-hand side that the first column indicates the thicknesses in millimeters of the layers. In the second column are given the successive layers of a blanket according to the invention and such as shown on FIG. 2. In the third column are given the successive layers of a blanket according to the prior art which comprises as mentioned at the beginning of this description a layer of cellular rubber interposed between two layers of fabric whereas the blanket of the invention on the contrary comprises a layer of fabric interposed between two layers of cellular rubber. At last in the fourth column of the Table are given the layers of the blanket according to the document FR-A-2,461,596 which as should be recalled only comprises one single layer of cellular rubber and a base layer consisting of several layers of fabric bonded with neoprene. In the three cases as seen on the Table a hard layer of elastomer is associated with the lithographic layer.
The behaviour in compression of the three blankets mentioned hereinabove has been studied with regard to the material of the blanket which is driven or shifted upon the compression to the right and/or to the left of the center O of the pressure area as shown by the arrows F on FIG. 3.
Reference should be had to FIG. 4 which shows the displacement of material or the shearing C plotted versus the distance D with respect to the center O of the pressure area and this for the three blankets of the Table referred to hereinabove. It is immediately seen that the curve C1 which corresponds to the blanket of the invention is substantially flat, i.e. practically no sidewise displacement of the material of the blanket according to the invention occurs upon compression contrary to the prior art blanket (curve C2) and to the blanket according to the document FR-A-2,461,596 (curve C3) which however exhibits a less marked tendency to shearing than the blanket according to the prior art (curve C2).
It is thus understood that with the blanket of the invention the quality of impression and the travelling of the web of paper P passing between both blanket-carrying cylinders (FIG. 3) are very substantially improved in view of the absence of sidewise displacement or of shearing at the surface. This means that the blankets of the invention will have a neutral dynamic behaviour when rolling on the web of paper P.
Furthermore it should be noted that with a distance AA' given by the machine (see FIG. 3) it is advisable to have a lower generated pressure. In other words it is advisable to obtain a gain in compressibility in order in particular as explained at the beginning of this description to avoid any sagging of the blanket in the long run.
This gain in compressibility is clearly illustrated by the curve C4 of FIG. 5 corresponding to the blanket according to this invention. This curve shows that the gain in compressibility with respect to the blankets of the prior art (curve C5) and to the blankets according to the document FR-A-2,461,596 (curve C6) is definitely improved the latter however exhibiting some gain in compressibility with respect to the blankets of the prior art (curve C5).
It results from all the foregoing that the blanket according to the invention is remarkable in particular from the standpoint of the gain in compressibility and of the absence of shearing which reflects advantageously upon the quality of impression of the paper, upon the flow rate or the travelling of the paper and upon the service life of the blanket, this essentially owing to the provision in the said blanket of a layer of fabric held in sandwich-fashion between two layers of cellular rubber having identical or different moduli of elasticity.
It should be understood that the invention is not at all limited to the embodiments described and illustrated which have been given by way of example only.
On the contrary, the invention comprises all the technical equivalents of the means described as well as their combinations if the latter are carried out according to its gist. | The present invention relates to an elastic and compressible printing blanket element.
This element essentially comprises a lithographic or printing layer (1), a hard layer of elastomer (2), a layer of cellular rubber (3), a layer of fabric (4) and another layer (5) of cellular rubber forming a base layer and the modulus of elasticity in compression of which is identical with or smaller than the modulus of elasticity of the layer (3).
This printing element or blanket is applicable in any types of offset printing machines. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Division of prior application Ser. No. 12/355,338, filed Jan. 16, 2009, now abandoned, which in turn is a Division of Ser. No. 10/726,692, filed Dec. 4, 2003, now U.S. Pat. No. 7,491,515 which claims priority from U.S. Provisional Application No. 60/430,654, filed Dec. 4, 2002, hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to recombinant polypeptides that are useful for diagnosing American trypanosomiasis, or Chagas disease. Chagas disease is caused by the infectious agent Trypanosoma cruzi . More particularly, the invention relates to specific combinations of recombinant T. cruzi polypeptides, synthesized using genetic engineering techniques, and to constructs and processes for producing the recombinant polypeptides, and to an assay and kit for detecting T. cruzi infection which employs the recombinant polypeptides.
2. Background
Chagas disease is a zoonosis caused by the protozoan parasite, Trypanosoma cruzi . This organism is primarily transmitted through contact with its triatomine insect vectors, but transmission by transfusion of contaminated blood and congenital transmission also are important. Historically Chagas disease has been a public health problem in all of Latin America, with the exception of the Caribbean nations. The World Health Organization estimates that 16-18 million persons are chronically infected with T. cruzi , and that 45,000 deaths occur each year due to the illness. Infection with T. cruzi is life-long and specific drug treatment lacks efficacy and often causes serious side effects. Ten to thirty percent of T. cruzi -infected persons develop chronic symptomatic Chagas disease, and the burden of disability and mortality in the endemic countries is enormous.
An estimated 80,000 to 100,000 T. cruzi -infected persons now live in the United States. These immigrants pose a risk for transfusion-associated transmission of the parasite here and in other countries to which Latin Americans have emigrated. Eight such cases have been reported in the United States, Canada, and Europe, all of which occurred in immunosuppressed patients in whom acute T. cruzi infection was diagnosed because of the fulminant course of the illness. Most transfusions are given to immunocompetent patients in whom acute Chagas disease would be a mild illness, and thus it is reasonable to assume that many other undetected instances of transfusion-associated transmission of T. cruzi have occurred in the United States and other industrialized nations. The question of whether blood donated in the United States should be screened serologically for antibodies to T. cruzi has been considered for at least a decade by both public and private entities involved in blood banking. A panel of experts convened in early 2000 by the American Red Cross to consider this issue recommended unanimously that our blood supply be screened serologically. Implementation of such a recommendation, however, is not an option currently because no test for T. cruzi infection has been cleared by the FDA for screening donated blood.
Diagnosis of T. cruzi infection presents problems. Demographic and clinical data are suggestive at best. Parasitologic tests, e.g., xenodianosis, hemoculture and PCR are insensitive. Other serologic tests are generally insensitive and lack specificity, as false positive reactions often occur with specimens from patients having infectious diseases, such as leishmaniasis, syphilis, or malaria; autoimmune diseases; and other parasitic and non-parasitic illnesses.
Such conventional tests include indirect immunofluorescence (IIF), indirect hemagglutination (IHA), and complement fixation (CF) tests, as well as enzyme-linked immunosorbent assays (ELISA or EIA). Due to the lack of sensitivity and specify of the three commonly used assays, when a sample has a positive result from any, the blood must be discarded. Table I shows that in a major Brazilian blood bank (Hemocentro, são Paulo, Brazil), up to 3.43% of blood donations fall into this category.
TABLE I
IIF
IHA
CF
% w/ Results
+
+
+
0.68%
+
−
+
0.71%
+
+
−
−
+
+
+
−
−
2.04%
−
+
−
−
−
+
TOTAL:
3.43%
Commercially available ELISAs include lysate-based tests such as the Chagas Enzyme Immunoassay (EIA), available from Abbott Laboratories of Abbott Park, Ill. (the subject of FDA 510(k) Premarket Notification No. K933716, herein incorporated by reference in its entirety); the Chagas' IgG ELISA, available from Meridian Bioscience, Inc. of Cincinnati, Ohio, and its predecessor, Gull Laboratories (the subject of FDA 510(k) Premarket Notification No. K911233, herein incorporated by reference in its entirety); and the Chagas' kit (EIA method), available from Hemagen Diagnostics, Inc., of Waltham, Mass. (the subject of FDA 510(k) Premarket Notification No. K930272, herein incorporated by reference in its entirely). However, because these tests have less than optimal sensitivities and specificities, their use for screening donated blood would fail to detect some T. cruzi -infected units and also would cause substantial numbers of otherwise usable units to be discarded needlessly.
One of the present inventors has previously developed a radioimmune precipitation assay (RIPA), described in Kirchhoff L V, Gam A A, Gusmao R D, Goldsmith R S, Rezende J M, Rassi A. “Increased specificity of serodiagnosis of Chagas' disease by detection of antibody to the 72 and 90 kDa glycoproteins of Trypanosoma cruzi .” J Infect Dis 1987; 155:561-564, herein incorporated by reference in its entirety. This test is considered the benchmark against which other tests are measured, and it is the only current option for confirmatory testing in the United States. Unfortunately, the RIPA costs $175 per assay, and at that price, screening the approximately 13 million units of blood donated each year would cost over $2 billion.
Therefore, the present inventors have further developed recombinant assays for detection of T. cruzi infection. A typical recombinant polypeptide and method for assaying is described by them in U.S. Pat. No. 5,876,734, No. 6,228,601, and PCT Publication No. WO 95/25797, each of which is herein incorporated by reference in its entirety. Such assays for T. cruzi infection based on recombinant antigens, in contrast to those utilizing native antigens (e.g., the conventional lysate-based assays), as discussed above, will be more accurate, i.e., the sensitivity and specificity will be higher.
Furthermore, the recombinant assays of the invention present manufacturing advantages over the materials for the RIPA and conventional tests. Once the molecular biology has been completed, the recombinant antigens are produced in Escherichia coli , thus eliminating completely any biohazard associated with growing the parasites in liquid culture. This is a substantive advantage, as many cases of laboratory-acquired T. cruzi infection have been reported. Additionally, recombinant antigens produced in E. coli are much easier to purify, quantitate, and standardize than antigen lysates produced in liquid cultures of parasites, thus facilitating the manufacture of a consistent product and simplifying compliance with governmental regulations. A final advantage lies in the fact that several of the recombinant proteins presented in this application are comprised of two to four distinct protein segments derived from separate T. cruzi genes. This use of hybrid recombinant proteins also facilitates manufacture of an assay in that several antigenically distinct proteins are obtained in a single purification, quantitation, and standardization run.
SUMMARY OF THE INVENTION
The present invention utilizes recombinant proteins for detecting T. cruzi infected blood. The invention utilizes specific polypeptide sequences that correspond to fusion proteins FP3, FP4, FP5, FP6, FP7, FP8, FP9 and FP10 as described below. Isolated polynucleotides that encode the inventive polypeptides according to the present invention are also utilized, as are cells transformed with a recombinant plasmid that expresses a polypeptide according to the invention. The present invention is similar to that which is described in U.S. Pat. No. 5,876,734, herein incorporated by reference in its entirety. However, the present invention replaces the proteins in the process with the recombinant proteins of this invention to achieve similar or superior results.
The present invention also provides a method for detecting the presence of antibodies to T. cruzi in an individual, comprising the steps of contacting a putative anti- T. cruzi antibody-containing sample from an individual with a polypeptide according to the invention that is typically attached or conjugated to a carrier molecule or attached or conjugated to a solid phase; allowing anti- T. cruzi and other antibodies in said sample to bind to said polypeptide; washing away unbound anti- T. cruzi antibodies; and adding a compound that enables detection of the anti- T. cruzi antibodies which are specifically bound to the polypeptide. The compound that enables detection of the anti- T. cruzi antibodies may be selected from the group consisting of a colorometric agent, a fluorescent agent, a chemiluminescent agent and a radionucleotide.
Also provided in accordance with the present invention is a kit for diagnosing the presence of anti- T. cruzi antibodies in a sample, comprising a container in which a polypeptide according to the invention is attached or conjugated to a carrier molecule or attached or conjugated to a solid phase; and directions for carrying out the method according to the invention. The kit additionally may comprise a container of a compound that binds to anti- T. cruzi antibodies and that renders said antibodies detectable.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a description of the prior art.
FIG. 1 a - 1 h are schematic representations of the recombinant proteins utilized in the invention.
FIG. 2 is a bar graph showing reactivity of various blood specimens with recombinant proteins used alone or in combination as target antigens in ELISAs.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 a - 1 h represent the recombinant proteins of the invention, with the various letters indicating known protein sequences, as follows. The Figs. are schematic diagrams of the recombinant T. cruzi proteins, comprised of segments A through L. Solid segments (A, C, D, F, H, I, and K) represent nonrepetitive proteins having amino acid sequences that are unrelated to each other. Saw-tooth segments (B, E, G, J, and L) represent repetitive proteins having amino acid sequences that are unrelated to each other and unrelated to those of the nonrepetitive proteins. The relative sizes and numbers of repeats in the repetitive proteins are roughly represented in the Figs. The sizes and shapes of the nonrepetitive segments bear no relation to the actual proteins.
The following information refers to FIGS. 1 and 1 a - 1 h in which the recombinant proteins Ag15, FP3, FP4, FP5, FP6, FP7, FP8, FP9 and FP10 are depicted schematically. These proteins are derived from T. cruzi , the protozoan parasite that causes Chagas disease, and are formed from of proteins A through L as indicated, and defined herein. There are no substantive amino acid similarities among proteins A through L. Similarly there are no substantive DNA sequence similarities among the segments that encode proteins A through L. The T. cruzi DNA sequences that encode proteins A through L were cloned in combination into pGEX and pET plasmid vectors, such as pET-32a. Strains of Escherichia coli were transfected with the recombinant vectors bearing the T. cruzi DNA sequences, and the bacteria were incubated in liquid culture under conditions favoring synthesis of the recombinant proteins. The latter proteins were subsequently affinity-purified and then used as target antigens in ELISAs. ELISAs in which proteins Ag15, FP3, FP4, FP5, FP6, FP7, FP8, FP9, and FP10, alone or in combination are employed as target antigens are useful as sensitive and specific detectors of anti- T. cruzi antibodies in blood specimens obtained from persons who are chronically infected with this parasite. The detection of such antibodies is the primary means of identifying persons who are chronically infected with T. cruzi.
The following paragraphs contain information relating to the naming, localization, and function of proteins A through L, as well as the corresponding GenBank accession numbers of the sequences to which they are related and relevant publications.
It should be noted that the T. cruzi gene segments that encode protein segments A through L generally are shortened versions of the native coding regions. In this context, the constructs that encode single segments (i.e., FP5 and FP9), as well as all the others that encode more than one segment, are all unique, because, even if the individual components from which the various recombinant proteins of this invention are known, the segments of the invention have not been combined previously as described herein.
Protein AB. This hybrid recombinant protein, also designated Ag15 [amino acids 218-507 of SEQ ID NO: 50] in FIG. 1 , is derived from the TCR27 gene of T. cruzi [nucleotides 652-2151 of SEQ ID NO: 35]. Protein A is the amino terminal nonrepetitive portion of the TCR27 protein, and Protein B is comprised of approximately 18 of the 14 amino acid repeats that make up the central portion of the TCR27 protein. The two native TCR27 genes sequenced contained approximately 69 and 105 of the 14-amino acid repeats.
Nucleotide sequence data that include the Ag15 DNA sequence were deposited with GenBank and EMBL databases by Keiko Otsu, John E. Donelson, and Louis V. Kirchhoff with the accession number L04603 and are described in U.S. Pat. No. 5,876,734 and No. 6,228,601, issued to Louis V. Kirchhoff and Keiko Otsu (each of which is herein incorporated by reference in its entirety). These references also present DNA and inferred protein sequences that include the Ag15 DNA and inferred protein sequences. The Ag15 DNA and inferred protein sequences are additionally presented in Otsu K, Donelson J E, Kirchhoff L V. “Interruption of a Trypanosoma cruzi gene encoding a protein containing 14-amino acid repeats by targeted insertion of the neomycin phosphotransferase gene.” Mol Biochem Parasitol 1993; 57:317-330, herein incorporated by reference in its entirety.
Protein C. This is a calcium binding protein of T. cruzi , initially called 1F8 and later designated the flagellar calcium binding protein (FCaBP) [amino acids 508-717 of SEQ ID NO: 36]. The accession number of the original 1F8 DNA sequence [nucleotides 1522-2151 of SEQ ID NO: 35] deposited in GenBank is K03278. The Protein C DNA and inferred protein sequences are presented in Gonzalez A, Lerner T J, Huecas M, Sosa-Pineda B, Nogueira N, Lizardi P M. “Apparent generation of a segmented mRNA from two separate tandem gene families in Trypanosoma cruzi .” Nucleic Acids Res 1985; 13(16):5789-804, herein incorporated by reference in its entirety.
FIG. 1 a shows a first protein (FP3) [amino acids 218-717 of SEQ ID NO: 36] in accordance with the invention. Specifically, FP3 corresponds essentially to the combination of Ag15 ( FIG. 1 ), and by Protein C. The DNA sequence encoding FP3 [SEQ ID NO: 49], also essentially corresponds to the sequences coding for Ag15 and Protein C.
Protein D. This is the protein core of a surface glycoprotein of T. cruzi that is referred to as GP72 [amino acids 1-217 of SEQ ID NO: 36]. The accession number of the original gp72 DNA sequence [nucleotides 1-651 SEQ ID NO: 35] deposited in GenBank is M65021. The Protein D DNA and inferred protein sequences are presented in Cooper R, Inverso J A, Espinosa M, Nogueira N, Cross G A. “Characterization of a candidate gene for GP72, an insect stage-specific antigen of Trypanosoma cruzi .” Mol Biochem Parasitol 1991; 49(1):45-59, herein incorporated by reference in its entirety.
FIG. 1 b shows a second protein (FP4) [SEQ ID NO: 36] in accordance with the invention. The DNA sequence [SEQ ID NO: 35] that encodes Protein DABC which is a single continuous coding region, essentially corresponds to the DNA sequences from which it was constructed.
Protein E. This is a segment of the flagellar repetitive protein (FRA) of T. cruzi comprised of approximately nine repeats consisting of 68 amino acids each, shown as FIG. 1 c (FP5) [SEQ ID NO: 38]. The accession number of the original Protein E DNA sequence [SEQ ID NO: 37] deposited in GenBank is J04015. The Protein E DNA and inferred protein sequences are presented in Lafulle J J, Linss J, Krieger M A, Souto-Padron T, de Souza W, Goldenberg S. “Structure and expression of two Trypanosoma cruzi genes encoding antigenic proteins bearing repetitive epitopes.” Mol Biochem Parasitol 1989; 35(2):127-136, herein incorporated by reference in its entirety.
Protein FGH. This is a protein [SEQ ID NO: 40] encoded by a modified version of the T. cruzi TCR39 gene that was artificially constructed [SEQ ID NO: 39], shown as FIG. 1 e (FP7). The modification entailed reducing the length of the central portion of the TCR39 gene that encodes the 12-amino acid repeats. Protein F is the amino terminal nonrepetitive segment of the TCR39 protein. Protein G is comprised of approximately 13 of the 12-amino acid repeats that make up the central portion of the TCR39 protein. Protein H is the carboxy terminal nonrepetitive segment of the TCR39 protein. The accession number of the original, i.e., the unmodified, Protein FGH DNA sequence deposited in GenBank is U15616. The TCR39 DNA and inferred protein sequences, which include the entire Protein FGH sequences, are presented in Gruber A, Zingales B. “ Trypanosoma cruzi : characterization of two recombinant antigens with potential application in the diagnosis of Chagas' disease.” Exp Parasitol 1993; 76(1):1-12, herein incorporated by reference in its entirety.
FIG. 1 d shows another hybrid recombinant protein (FP6, Protein FGHE) [SEQ ID NO: 42] in accordance with the invention. The DNA sequence that encodes Protein FGHE [SEQ ID NO: 41], which is a single continuous coding region, essentially corresponds to the DNA sequences from which it was constructed.
Protein IJK. This is a protein [SEQ ID NO: 44] encoded by a modified version of the T. cruzi shed acute phase antigen (SAPA) gene that was artificially constructed [SEQ ID NO: 43], as shown in FIG. 1 f (FP8). The modification entailed reducing the length of the central portion of the SAPA gene that consists of 12-amino acid repeats. Protein I is the amino terminal nonrepetitive segment of the SAPA protein. Protein J is comprised of approximately nine of the 12-amino acid repeats that make up the central portion of the SAPA protein. Protein K is the carboxy terminal nonrepetitive segment of the SAPA protein. The accession number of the original, i.e., the unmodified, Protein UK DNA sequence deposited in Gen Bank is J03985. The SAPA DNA and protein sequences, which include the entire Protein UK sequences, are presented in Affranchino J L, Pollevick G D, Frasch A C C. “The expression of the major shed Trypanosoma cruzi antigen results from the developmentally-regulated transcription of a small gene family.” FEBS Lett 1991; 280:316-320, herein incorporated by reference in its entirety.
Protein L. This is a microtubule-associated repetitive protein (MAP) [SEQ ID NO: 46] of T. cruzi that is comprised of approximately five repeats consisting of 38 amino acids each, as depicted in FIG. 1 g (FP9). The accession number of the original Protein L DNA sequence [SEQ ID NO: 45] deposited in GenBank is S68286. The Protein L DNA and inferred protein sequences are presented in Kerner N, Liegeard P, Levin M J, Hontebeyrie-Joskowicz M. “ Trypanosoma cruzi : antibodies to a MAP-like protein in chronic Chagas' disease cross-react with mammalian cytoskeleton.” Experimental Parasitology 1991; 73(4):451-459, herein incorporated by reference in its entirety.
FIG. 1 h shows another hybrid recombinant protein (FP10, Protein UKL) [SEQ ID NO: 48] in accordance with the invention. The DNA sequence that encodes Protein IJKL [SEQ ID NO: 47], which is a single continuous coding region, essentially corresponds to the DNA sequences from which it was constructed.
Additionally, combinations of the various recombinant proteins depicted in the Figs. may be used. While it is possible to combine one or more of the recombinant proteins to form longer recombinant proteins, typically more than one recombinant protein is used simultaneously. For example, simultaneous uses of FP4 and FP5, FP5 and FP6, as well as FP4 and FP6, and combinations using more than two recombinant proteins (e.g., FP4, FP6 and FP10) are considered within the scope of the present invention. It is believed that the sensitivity and specificity of the assays according to the invention are sufficient to meet FDA standards for screening the blood supply of the United States.
Additionally, as described in U.S. Pat. No. 6,228,601 (herein incorporated by reference in its entirety), polypeptides need not correspond exactly over their entire lengths to be considered within the scope of the invention. For example, a wide variety of polypeptides which contain at least one epitope embodied in the polypeptides of the invention can be used in accordance with the present invention. Based on the nucleotide sequences, polypeptide molecules also can be produced (1) that include sequence variations, relative to the naturally-occurring sequences, (2) that have one or more amino acids truncated from the naturally-occurring sequences and variations thereof, or (3) that contain the naturally-occurring sequences and variations thereof as part of a longer sequence.
In this description, polypeptide molecules in categories (1), (2) and (3) are said to “correspond” to the amino acid sequences of the recombinant proteins of the invention. Such polypeptides also are referred to as “variants.” The category of variants within the present invention includes, for example, fragments and muteins of proteins A though L, as well as larger molecules that consist essentially at least one protein sequence A through L, alone or in combination with other proteins A to L.
In this regard, a molecule that “consists essentially of” protein A to L, alone or in combination with any other proteins A to L, is one that is immunoreactive with samples from persons infected with T. cruzi , but that does not react with samples from patients with leishmaniasis, schistosomiasis, and other parasitic and infectious diseases, with samples from patients with autoimmune disorders and other illnesses, and with specimens from normal persons.
A “mutein” is a polypeptide that is homologous to the protein to which it corresponds, and that retains the basic functional attribute—the ability to react selectively with samples from persons infected with T. cruzi —of the corresponding region. For purposes of this description, “homology” between two sequences connotes a likeness short of identity indicative of a derivation of the first sequence from the second. In particular, a polypeptide is “homologous” to the corresponding protein if a comparison of amino acid sequences between the polypeptide and the corresponding region reveals an identity of greater than 40%, preferably greater than 50% and more preferably 70%. Such sequence comparisons can be performed via known algorithms, such as those described in Pearson W R, Lipman D J. “Improved tools for biological sequence comparison.” Proc Natl Acad Sci USA 1988; 85(8):2444-2448, herein incorporated by reference in its entirety, which are readily implemented by computer.
A fragment of a protein of the invention is a molecule in which one or more amino acids are truncated from that protein. Muteins and fragments can be produced, in accordance with the present invention, by known de novo synthesis techniques.
Also exemplary of variants within the present invention are molecules that are longer than a protein of the invention, but that contain the region or a mutein thereof within the longer sequence. For example, a variant may include a further fusion partner in addition to the protein of the invention. Such a fusion partner may allow easier purification of recombinantly-produced polypeptides. For example, use of a glutathione-S-transferase (26 kilodaltons, GST) fusion partner allows purification of recombinant polypeptides on glutathione agarose beads.
The portion of the sequence of a such molecule other than that portion of the sequence corresponding to the region may or may not be homologous to the sequence of a protein of the invention.
It will be appreciated that polypeptides shorter than the corresponding protein of the invention but that retain the ability to react selectively with samples from persons infected with T. cruzi are suitable for use in the present invention. Thus, variants may be of the same length, longer than or shorter than the protein of the invention, and also include sequences in which there are amino acid substitutions of the parent sequence. These variants must retain the ability to react selectively with samples from persons infected with T. cruzi.
In one embodiment, the assay of the invention uses FP4 as target antigen. Table II compares the results obtained by testing 45 pre-screened Argentinean specimens in an
TABLE II RIPA + − FP4 ELISA + 9 0 − 0 36
FP4 ELISA with those obtained by RIPA testing.
The data in Table II show that in this group of specimens, the sensitivity and specificity of the FP4 ELISA were both 100%
Similarly, the performance of an FP4+FP6 ELISA in comparison to RIPA was
TABLE III RIPA + − FP4 + FP6 ELISA + 10 1 − 0 78
assessed by testing 89 pre-selected Guatemalan specimens.
The data shown in Table III indicate that in this group of samples, the sensitivity of the FP4+FP6 ELISA was 100% and the specificity was 98.7%.
As shown in FIG. 2 , in a FP4+FP6 ELISA, performed using standard procedures, a group of previously characterized RIPA-positive samples from several Chagas-endemic countries gave a mean reactivity (absorbance) of 2.99. Thus FP4+FP6 is the preferred embodiment among the recombinant proteins tested alone and in combination in that experiment.
It should be apparent that embodiments other than those specifically described above may come within the spirit and scope of the present invention, such as recombinant proteins comprised of different combinations and/or spatial arrangements of proteins A to L. Hence, the present invention is not limited by the above description. | Recombinant polypeptides are disclosed that are useful for diagnosing American trypanosomiasis, or Chagas disease, a disease caused by the infectious agent Trypanosoma cruzi . Preferably, DNA sequences encoding the recombinant proteins are placed in plasmid vectors to be expressed in an organism. | 2 |
FIELD OF THE INVENTION
The present invention pertains to wear inserts. More specifically, the present inserts are particularly adapted for use in earth and road working machines, such as graders, scrapers, snow plows and the like.
BACKGROUND OF THE INVENTION
Earth and road working machines, such as graders, are used primarily to maintain or create a desired ground surface. The operation is typically accomplished by a machine having a mold board or like construction. A mold board is a long scoop-like member having a slight concave surface facing in the direction of travel. The mold board is pushed across the ground or road by the machine to perform a scraping-grading type action. As can be appreciated, such an operation subjects the mold board to harsh treatment, and left unchecked would quickly ruin the mold board. To avoid premature wearing of the mold board, a wear element is secured along the mold board's lower edge.
One common wear element used to protect mold boards is an elongate blade member. The blade members are generally fabricated in three and four foot long increments and bolted end-to-end across the entire lower edge of the mold board. With this construction, the blade forms a continuous working edge which engages the ground surface and protects the mold board. An example of such a blade is disclosed in U.S. Pat. No. 4,770,253 to Hallissy et al. After a certain length of time, the worn blades are replaced instead of the much more costly mold board.
Another common wear element used to protect mold boards involves a modified form of the blade and a plurality of picks. More specifically, the modified blade member is secured to the lower edge of the mold board. Like the wear blades discussed above, these blades are fabricated in three and four foot long increments and positioned end-to-end across the mold board. However, instead of a lower working edge, the blade defines means for securing the picks. The picks are generally bolted to the face of the blade or releasably retained (e.g., by a clip) within a socket defined in the blade. In any event, a plurality of the picks are secured in place along the blade to collectively form a discontinuous working edge for engaging the ground surface. Each pick defines a generally linear edge comprising a segment of the working edge. One example of such a wear element is disclosed in U.S. Pat. No. 4,753,299 to Meyers. In this construction, only the picks generally require replacement. Alternatively, the discontinuous edge can also be formed by a specially configured blade member, such as shown in U.S. Pat. No. 3,192,653 to Socin.
In order to increase the useful life of the wear element, its working edge is often provided with a hardened insert. The insert forms the leading face and at times the bottom face, to maximize the protection afforded the wear element. The inserts are generally brazed to the wear element along one or two mounting faces. The inserts, however, are at times broken off from the wear element. Once the insert is lost, the wear element is quickly worn away and ruined. This results not only in higher maintenance and repair costs, but also increased down time for the machine.
SUMMARY OF THE INVENTION
The present invention is directed to wear inserts which protect and lengthen the useful life of an element subjected to abrasive conditions. The inserts of the present invention have particular usefulness in earth and road working machines, such as graders, scrapers and snow plows. Nonetheless, the present inserts could be used in other abrasive environments.
The present wear insert is formed with a general U-shaped configuration which defines a pair of opposed legs and a central gap therebetween. The gap enables the insert to wrap around a mounting flange of the protected element to greatly reduce the risk of breaking the insert from the element. Preferably, the insert includes six discrete mounting faces which are each fixed to the working element to preclude its unintended removal. Moreover, selected corners of the insert are chamfered to facilitate the flow of a brazing flux across all the mounting faces during fabrication.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a grader blade assembly including the present invention.
FIG. 2 is a cross sectional view taken along line 2--2 in FIG. 1.
FIG. 3 is a perspective view of an alternative grader blade assembly including the present invention.
FIG. 4 is a cross sectional view taken along line 4--4 in FIG. 3.
FIG. 5 is an enlarged side view of the insert and pick construction illustrating the fabrication of the present invention.
FIG. 6 is a perspective view of a wear insert in accordance with the present invention.
FIG. 7 is a top plan view of the wear insert.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Wear insert 10 (FIGS. 6 and 7), in accordance with the present invention, is adapted to form a protective barrier for the member to which it is attached. In the preferred construction, wear inserts 10 are fixed to the lower edge of mold board assemblies 12 (FIGS. 1 and 3), such as used in graders, scrapers, snow plows and the like. Assemblies 12 generally comprise a mold board 14 and a plurality of wear elements 16. Wear element 16 may be an elongated blade member 16a, or a blade and pick construction 16b. The elongate blade member 16a and the blade and pick construction 16b operate in essentially the same way as in the prior art devices. Wear elements 16 are secured along the lower edge 18 of the mold board, so that they engage and work the ground or road surface and thereby protect the mold board. Since the wear elements 16 are subjected to abrasive conditions, they are equipped with wear inserts 10 to maximize their useful life.
Wear insert 10 has a generally U-shaped configuration which is designed to wrap around a mounting flange 26 of the protected member 16 to reliably hold the insert in place (FIGS. 1-4). More specifically, insert 10 is comprised of a front leg 28, a rear leg 30 and a lower bight segment 32 (FIGS. 2 and 4-7). The spaced apart legs 28, 30 include inner walls 34, 36, respectively, to cooperatively define a central gap 38 therebetween. The inner boundary of gap 38 is defined by end wall 40. These three walls define three independent mounting surfaces which, as discussed below, are fixed to corresponding surfaces defined by the wear element 16. Additional mounting surfaces are defined by top wall 42 of front leg 28 and the top and rear walls 44, 46 of rear leg 30.
Insert 10 further defines a generally upright leading surface 48 which faces in the direction of movement when the insert is mounted to member 16. Leading surface 48 is adapted to engage and accept the impact and other wearing forces associated with the operation. The bottom surface 50 of the insert is formed by a pair of angled segments 52, 54. Tip segment 52 extends rearwardly from leading surface 48 at about a right angle. The intersection of the leading and tip surfaces form the front leading edge 56 of the insert. The tip surface 52 is drawn along the ground or road and generally accepts wearing forces during the operation. The mold board may be oriented so that the leading surface is upright or inclined slightly in either direction. The wearing forces will vary depending on the particular operation. Sloped segment 54 is angled to slope upwardly and rearwardly from tip segment 52 at an angle of about 25° and preferably at 24° 45'. Of course, it could be oriented at other angles. Sloped surface 54 is angled relative to tip segment 52 so that it lies above the ground or road surface when the mold board is rearwardly inclined.
The lower working portion of the protected member 16 is specially configured to accommodate the unique construction of the present invention (FIGS. 2, 4 and 5). Specifically, member 16 defines a pair of downwardly extending flanges 26, 60. Flanges 26, 60 extend transversely across member 16 in a spaced apart relationship to define a central groove 62 therebetween. In addition, front flange 26 is offset from the front face 64 of member 16 to define a forward groove 66. Grooves 62, 66 are shaped to matingly receive therein legs 28, 30 of wear insert 10. Preferably, legs 28, 30 are fit within their respective grooves 62, 66 to accommodate the flow of a brazing solder therebetween. The interlocked relationship between the legs 28, 30 of insert 10 and flanges 26, 60 of member 16 form an enhanced mounting arrangement for the insert that significantly reduces the risk of breakage.
Front flange 26 is defined by a pair of side faces 68, 70 and an end face 72. Likewise, rear flange 60 is defined by a pair of side faces 74, 76 and an end face 78. Side faces 70 and 74 are opposed to one another. Further, side faces 70, 74 in cooperation with inner face 80 form the downwardly opening central groove 62. Side face 68 along with upper face 82 form the forward groove 66 which opens forwardly as well as downwardly. In the assembled construction, the interlocked relationship between wear insert 10 and member 16 defines six discrete pairs of opposed surfaces in close abutting relation. More specifically, with legs 28, 30 received within grooves 62, 66: top wall 42 opposes upper face 82; inner wall 34 opposes side face 68; end wall 40 opposed end face 72; inner wall 36 opposes side face 70; top wall 44 opposes inner face 80; and rear wall 46 opposes side wall 74 (FIG. 5). In the preferred construction sloped surface 54 is aligned with end face 78 in a generally planar relationship. Of course other arrangements could be used.
In the preferred construction, wear insert 10 is brazed to member 16 along the six opposed surfaces noted above. In particular, the assembly is preferably fabricated by placing a plurality of solder rods 81 along end wall 40 within central gap 38 of insert 10. With the solder rods in place, insert 10 and member 16 are assembled together, as shown in FIG. 5. During the brazing process the the heated solder flows by capillary action along the opposed surfaces of insert 10 and member 16 in the directions indicated by arrows 91 and 99. Specifically, the solder flows from between end face 72 and end wall 40 and up along each side of front flange 26. In the forward direction (arrow 91), the solder flows upward between side face 68 and inner wall 34. As it reaches upper face 82, the solder flows around corner 84 and between face 82 and wall 42. In the rearward direction (arrow 99), the solder flows upward between side face 70 and inner wall 36, around corner 86, between top wall 44 and inner face 80, around corner 88 and downward between rear wall 46 and side wall 74. Preferably, the amount of solder provided permits the solder to flow to the front face 64 and inclined surface 54, but not beyond. However, an additional machining step can be employed in the event the solder seeps out from between the opposed mounting surfaces. In the preferred construction, corners 84, 86 and 88 are chamfered to ensure the free flow of the solder over all of the mounting surfaces. This interlocked construction in combination with the six discrete pairs of fixed mounting faces provides a durable construction for increased reliability. For additional security and integrity of the construction, the adjacent inserts are brazed together along their abutting sides 90, 92 (FIGS. 6 and 7).
The insert is preferably composed of a sintered combination of tungsten and cobalt. In particular insert 10 is comprised of a sintered hard metal composite of unsintered nodules of pre-blended hard metal powders of two different grades having distinctly different properties from one another. One grade has a high hardness characteristic to withstand impact forces. The other grade has a high toughness characteristic to withstand wearing forces. The composite substance possesses greater hardness and toughness characteristics than the average of the two grades considered separately. The specific fabrication and composition of the preferred material is disclosed in U.S. Pat. No. 4,956,012 to Jacobs which is incorporated by reference herein. The specially sintered composite is particularly well suited for the fabrication of inserts 10. During use of the inserts, leading face 48 primarily experiences impact forces whereas tip surface 52 primarily experiences wear forces. The preferred composite offers a beneficial compromise between toughness and hardness. Nevertheless, a variety of different materials could be used in the fabrication of wear inserts 10.
The above discussed structures and operations are merely preferred embodiments of the present invention. Various changes can be made without departing from the spirit and scope of the invention, as set forth in the claims. | A wear insert for protecting a working element operating in an abrasive environment comprises a pair of spaced apart legs which define a gap for receiving a mounting flange of the protected working element. The wear element wraps around the mounting flange and interlocks with cooperative flanges of the working element to securely hold the insert to the working element. | 0 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to molecules which are capable of causing exon skipping and, in particular, relates to molecules which are capable of causing exon skipping in the dystrophin gene.
BACKGROUND OF THE INVENTION
Duchenne muscular dystrophy (DMD) is a severe X-linked muscle wasting disease, affecting 1:3500 boys. Prognosis is poor: loss of mobility by the age of 12, compromised respiratory and cardiac function by late teens, and probable death by the age of 30. The disease is caused by mutations within the large dystrophin gene, such that the reading frame is disrupted leading to lack of dystrophin protein expression and breakdown of muscle fibre integrity [1]. The dystrophin gene is large, with 79 exons. The most common DMD mutation is genomic deletion of one or more exons, generally centred around hotspots involving exons 44 to 55 and the 5′ end of the gene [2]. Mutations of the dystrophin gene that preserve the reading frame result in the milder, non-life threatening Becker muscular dystrophy (BMD).
Exon skipping induced by antisense oligoribonucleotides (AOs), generally based on an RNA backbone, is a future hope as a therapy for DMD in which the effects of mutations in the dystrophin gene can be modulated through a process of targeted exon skipping during the splicing process. The splicing process is directed by complex multi-particle machinery that brings adjacent exon-intron junctions in pre-mRNA into close proximity and performs cleavage of phosphodiester bonds at the ends of the introns with their subsequent reformation between exons that are to be spliced together. This complex and highly precise process is mediated by sequence motifs in the pre-mRNA that are relatively short semi-conserved RNA segments to which bind the various nuclear splicing factors that are then involved in the splicing reactions. By changing the way the splicing machinery reads or recognises the motifs involved in pre-mRNA processing, it is possible to create differentially spliced mRNA molecules.
It has now been recognised that the majority of human genes are alternatively spliced during normal gene expression, although the mechanisms involved have not been identified. Using antisense oligonucleotides, it has been shown that errors and deficiencies in a coded mRNA could be bypassed or removed from the mature gene transcripts. Indeed, by skipping out-of-frame mutations of the dystrophin gene, the reading frame can be restored and a truncated, yet functional, Becker-like dystrophin protein is expressed. Studies in human cells in vitro [3, 4] and in animal models of the disease in vivo [5-9] have proven the principle of exon skipping as a potential therapy for DMD (reviewed in [10]). Initial clinical trials using two different AO chemistries (phosphorodiamidate morpholino oligomer (PMO) and phosphorothioate-linked 2′-O-methyl RNA (2′OMePS)) [11] have recently been performed, with encouraging results. Indisputably impressive restoration of dystrophin expression in the TA muscle of four DMD patients injected with a 2′OMePS AO to exon 51 has been reported by van Deutekom et al. [11].
However, it should be noted that, relative to 2′OMePS AOs, PMOs have been shown to produce more consistent and sustained exon skipping in the mdx mouse model of DMD [12-14; A. Malerba et al, manuscript submitted], in human muscle explants [15], and in dystrophic canine cells in vitro [16]. Most importantly, PMOs have excellent safety profiles from clinical and pre-clinical data [17].
The first step to a clinical trial is the choice of the optimal AO target site for skipping of those dystrophin exons most commonly deleted in DMD. In depth analysis of arrays of 2′OMePS AOs have been reported [18, 19], and relationships between skipping bioactivity and AO variables examined.
One problem associated with the prior art is that the antisense oligonucleotides of the prior art do not produce efficient exon skipping. This means that a certain amount of mRNA produced in the splicing process will contain the out-of-frame mutation which leads to protein expression associated with DMD rather than expression of the truncated, yet functional, Becker-like dystrophin protein associated with mRNA in which certain exons have been skipped.
Another problem associated with the prior art is that antisense oligonucleotides have not been developed to all of the exons in the dystrophin gene in which mutations occur in DMD.
An aim of the present invention is to provide molecules which cause efficient exon skipping in selected exons of the dystrophin gene, thus being suitable for use in ameliorating the effects of DMD.
SUMMARY OF THE INVENTION
The present invention relates to molecules which can bind to pre-mRNA produced from the dystrophin gene and cause a high degree of exon skipping in a particular exon. These molecules can be administered therapeutically.
The present invention provides a molecule for ameliorating DMD, the molecule comprising at least a 25 base length from a base sequence selected from:
(SEQ ID NO: 1) a) XGA AAA CGC CGC CAX XXC XCA ACA GAX CXG; (SEQ ID NO: 2) b) CAX AAX GAA AAC GCC GCC AXX XCX CAA CAG; (SEQ ID NO: 3) c) XGX XCA GCX XCX GXX AGC CAC XGA XXA AAX; (SEQ ID NO: 4) d) CAG XXX GCC GCX GCC CAA XGC CAX CCX GGA; (SEQ ID NO: 5) e) XXG CCG CXG CCC AAX GCC AXC CXG GAG XXC; (SEQ ID NO: 6) f) XGC XGC XCX XXX CCA GGX XCA AGX GGG AXA; (SEQ ID NO: 7) g) CXX XXA GXX GCX GCX CXX XXC CAG GXX CAA; (SEQ ID NO: 8) h) CXX XXC XXX XAG XXG CXG CXC XXX XCC AGG; (SEQ ID NO: 9) i) XXA GXX GCX GCX CXX XXC CAG GXX CAA GXG; (SEQ ID NO: 10) j) CXG XXG CCX CCG GXX CXG AAG GXG XXC XXG; (SEQ ID NO: 11) k) CAA CXG XXG CCX CCG GXX CXG AAG GXG XXC; or (SEQ ID NO: 12) l) XXG CCX CCG GXX CXG AAG GXG XXC XXG XAC,
wherein the molecule's base sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in an exon of the dystrophin gene.
The exon of the dystrophin gene is selected from exons 44, 45, 46 or 53. More specifically, the molecule that causes skipping in exon 44 comprises at least a 25 base length from a base sequence selected from:
(SEQ ID NO: 1) a) XGA AAA CGC CGC CAX XXC XCA ACA GAX CXG; (SEQ ID NO: 2) b) CAX AAX GAA AAC GCC GCC AXX XCX CAA CAG; or (SEQ ID NO: 3) c) XGX XCA GCX XCX GXX AGC CAC XGA XXA AAX,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 44 of the dystrophin gene.
The molecule that causes skipping in exon 45 comprises at least a 25 base length from a base sequence selected from:
(SEQ ID NO: 4) d) CAG XXX GCC GCX GCC CAA XGC CAX CCX GGA; or (SEQ ID NO: 5) e) XXG CCG CXG CCC AAX GCC AXC CXG GAG XXC,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 45 of the dystrophin gene.
The molecule that causes skipping in exon 46 comprises at least a 25 base length from a base sequence selected from:
(SEQ ID NO: 6) f) XGC XGC XCX XXX CCA GGX XCA AGX GGG AXA; (SEQ ID NO: 7) g) CXX XXA GXX GCX GCX CXX XXC CAG GXX CAA; (SEQ ID NO: 8) h) CXX XXC XXX XAG XXG CXG CXC XXX XCC AGG; or (SEQ ID NO: 9) i) XXA GXX GCX GCX CXX XXC CAG GXX CAA GXG,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 46 of the dystrophin gene.
The molecule that causes skipping in exon 53 comprises at least a 25 base length from a base sequence selected from:
(SEQ ID NO: 10) j) CXG XXG CCX CCG GXX CXG AAG GXG XXC XXG; (SEQ ID NO: 11) k) CAA CXG XXG CCX CCG GXX CXG AAG GXG XXC; or (SEQ ID NO: 12) l) XXG CCX CCG GXX CXG AAG GXG XXC XXG XAC,
wherein the molecule's sequence can vary from the above sequence at up to two base positions, and wherein the molecule can bind to a target site to cause exon skipping in exon 53 of the dystrophin gene.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1F show a scheme summarizing the tools used in the design of PMOs to exon 53. ( FIG. 1 a ) Results of ESEfinder analysis, showing the location and values above threshold for SF2/ASF, SF2/ASF (BRCA1), SC35, SRp40 and SRp55, shown as grey and black bars, as indicated in the legend above. ( FIG. 1 b ) Output of PESX analysis, showing the location of exonic splicing enhancers as solid lines, and exonic splicing silencer as a dashed line. ( FIG. 1 c ) Rescue ESE analysis for exon 53, showing predicted ESEs by lines, and where they overlap, by a ladder of lines. ( FIG. 1 d ) AccessMapper analysis of in vitro hybridization. Synthetic pre-mRNA containing exon 53 and surrounding introns was subjected to a hybridization screen against a random hexamer oligonucleotide array, as described in Materials and Methods. Areas of hybridization, suggestive of areas of open conformation, are indicated by peaks on the graph. ( FIG. 1 e ) The position of the target sites of two 2′OMePS AOs studied previously [18] are shown for comparison. FIG. 1 ( f ) The location of the target sites for all the 25 mer and 30 mer PMOs to exon 53 used in this study are indicated by lines, and numbered according to the scheme used in Table 1, except for exclusion of the prefix “h53”;
FIG. 2 shows a comparison of active (effective) and inactive (ineffective) PMOs. RT-PCR analysis of mRNA from normal human skeletal muscle cells treated with PMOs to exon 53 demonstrates a wide variation in the efficiency of exon skipping. Over 75% exon skipping is seen with h53A30/2 (lane 5) and h53A30/3 (lane 6). h53A30/1 (lane 4) produced around 50% skipping, while the 25-mer h53A1 (lane 3) produced just over 10% skipping. In contrast, h53C1 (lane 2) was completely inactive. Lane 1 contains a negative control in which cells were treated with lipofectin but no PMO.
FIG. 3 shows an Mfold secondary structure prediction for exon 53 of the human dystrophin gene. MFOLD analysis [25] was performed using exon 53 plus 50 nt of the upstream and downstream introns, and with a maximum base-pairing distance of 100 nt. The intron and exon boundaries are indicated, as are the positions of the target sites of the bioactive PMO h53A30/2 (87.2% skip) and an inactive PMO (h53B2). Examples of open and closed RNA secondary structure are arrowed.
FIGS. 4A-4D show boxplots of parameters significant to strong PMO bioactivity. Comparisons were made between inactive PMOs and those inducing skipping at levels in excess of 75%. Boxplots are shown for parameters which are significant on a Mann-Whitney rank sum test: ( FIG. 4A ) PMO to target binding energy, ( FIG. 4B ) distance of the target site from the splice acceptor site, ( FIG. 4 C) the percentage overlap with areas of open conformation, as predicted by MFOLD software, and ( FIG. 4D ) the percentage overlap of the target site with the strongest area accessible to binding, as revealed by hexamer hybridization array analysis. Degrees of significance are indicated by asterisks. *: p<0.05; **: p<0.01; ***: p<0.001.
FIGS. 5A-5D show boxplots of parameters significantly different between bioactive (effective) and inactive (ineffective) PMOs. Comparisons were made between PMOs determined as bioactive (those that induced skipping at greater than 5%) and those that were not. Boxplots are shown for parameters which are significant from a Mann-Whitney rank sum test: ( FIG. 5A ) PMO to target binding energy, ( FIG. 5B ) distance of the target site from the splice acceptor site, ( FIG. 5C ) the score over threshold for a predicted binding site for the SR protein SF2/ASF, and ( FIG. 5D ) the percentage overlap of the target site with the strongest area accessible to binding, as revealed by hexamer hybridization array analysis. Degrees of significance are indicated by asterisks. *: p<0.05; **: p<0.01; ***: p<0.001.
FIGS. 6A-6B show a comparison of bioactivity of PMOs targeted to exon 53 in normal hSkMCs. Myoblasts were transfected with each of the 25 mer ( FIG. 6 a ) and 30 mer ( FIG. 6 b ) PMOs indicated at 500 nM using lipofectin (1:4). RNA was harvested after 24 hours and subjected to nested RT-PCR and products visualised by agarose gel electrophoresis.
FIGS. 7A-7B shows low dose efficacy and timecourse of skipping of the most bioactive PMOs in normal hSkMCs. ( FIG. 7 a ) hSkMC myoblasts were transfected with the PMOs indicated over a concentration range of 25 nM to 100 nM using lipofectin (1:4). RNA was harvested after 24 hours and subjected to nested RT-PCR, and products visualised by agarose gel electrophoresis. ( FIG. 7 b ) hSkMC myoblasts were transfected with 100 nM and 500 nM concentrations of PMO-G (+30+59) using lipofectin. RNA was harvested at the timepoints indicated following transfection and subjected to nested RT-PCR, and products visualised by agarose gel electrophoresis. Skipped (248 bp) and unskipped (460 bp) products are shown schematically.
FIGS. 8 a - 8 b show blind comparison of 13 PMO oligonucleotide sequences to skip human exon 53. Myoblasts derived from a DMD patient carrying a deletion of dystrophin exons 45-52 were transfected at 300 nM in duplicate with each of the PMOs by nucleofection. RNA was harvested 3 days following transfection, and amplified by nested RT-PCR. ( FIG. 8 a ) Bars indicate the percentage of exon skipping achieved for each PMO, derived from Image J analysis of the electropherogram of the agarose gel ( FIG. 8 b ). Skipped (477 bp) and unskipped (689 bp) products are shown schematically.
FIGS. 9 a - 9 b show the dose-response of the six best-performing PMOs. ( FIG. 9 a ) Myoblasts derived from a DMD patient carrying a deletion of dystrophin exons 45-52 were transfected with the six best-performing PMOs by nucleofection, at doses ranging from 25 nM to 400 nM. RT-PCR products derived from RNA isolated from cells 3 days post-transfection were separated by agarose gel electrophoresis. ( FIG. 9 b ) The percentage of exon skipping observed is expressed for each concentration of each PMO as a comparison of the percentage OD of skipped and unskipped band, as measured using Image J.
FIGS. 10A-10E show persistence of dystrophin expression in DMD cells following PMO treatment. ( FIG. 10 a ) Myoblasts derived from a DMD patient carrying a deletion of dystrophin exons 45-52 were transfected by nucleofection at 300 nM with each of the six best-performing PMOs, and were cultured for 1 to 10 days before extracting RNA. The percentage of exon skipping was compared using the percentage OD of skipped and unskipped bands, measured using Image J analysis of the agarose gel of the nested RT-PCR products shown in ( FIG. 10 b ). The experiment was repeated, but this time using the two best-performing PMOs from the previous analysis, and continuing the cultures for 21 days post-transfection ( FIG. 10 c and FIG. 10 d ). ( FIG. 10 e ) Western blot analysis was performed on total protein extracts from del 45-52 DMD cells 7 days after transfection with the six best PMOs (300 nM). Blots were probed with antibodies to dystrophin, to dysferlin as a muscle-specific loading control, and protogold for total protein loading control. CHQ5B myoblasts, after 7 days of differentiation were used as a positive control for dystrophin protein (normal).
FIG. 11 shows a comparison of most active PMOs in hDMD mice. PMOs were injected in a blind experiment into the gastrocnemius muscle of hDMD mice. RT-PCR analysis of RNA harvested from isolated muscle (L=left, R=right) was performed and products visualised by agarose gel electrophoresis. Quantification of PCR products was performed using a DNA LabChip.
DETAILED DESCRIPTION OF THE INVENTION
Without being restricted to any particular theory, it is thought by the inventors that the binding of the molecules to the dystrophin pre-mRNA interacts with or interferes with the binding of SR proteins to the exon of interest. SR proteins are involved in the slicing process of adjacent exons. Therefore, it is thought that interacting or interfering with the binding of the SR proteins interferes with the splicing machinery resulting in exon skipping.
The base “X” in the above base sequences is defined as being thymine (T) or uracil (U). The presence of either base in the sequence will still allow the molecule to bind to the pre-mRNA of the dystrophin gene as it is a complementary sequence. Therefore, the presence of either base in the molecule will cause exon skipping. The base sequence of the molecule may contain all thymines, all uracils or a combination of the two. One factor that can determine whether X is T or U is the chemistry used to produce the molecule. For example, if the molecule is a phosphorodiamidate morpholino oligonucleotide (PMO), X will be T as this base is used when producing PMOs. Alternatively, if the molecule is a phosphorothioate-linked 2′-O-methyl oligonucleotide (2′OMePS), X will be U as this base is used when producing 2′OMePSs. Preferably, the base “X” is only thymine (T).
The advantage provided by the molecule is that it causes a high level of exon skipping. Preferably, the molecule causes an exon skipping rate of at least 50%, more preferably, at least 60%, even more preferably, at least 70%, more preferably still, at least 76%, more preferably, at least 80%, even more preferably, at least 85%, more preferably still, at least 90%, and most preferably, at least 95%.
The molecule can be any type of molecule as long as it has the selected base sequence and can bind to a target site of the dystrophin pre-mRNA to cause exon skipping. For example, the molecule can be an oligodeoxyribonucleotide, an oligoribonucleotide, a phosphorodiamidate morpholino oligonucleotide (PMO) or a phosphorothioate-linked 2′-O-methyl oligonucleotide (2′OMePS). Preferably, the oligonucleotide is a PMO. The advantage of a PMO is that it has excellent safety profiles and appears to have longer lasting effects in vivo compared to 2′OMePS oligonucleotides. Preferably, the molecule is isolated so that it is free from other compounds or contaminants.
The base sequence of the molecule can vary from the selected sequence at up to two base positions. If the base sequence does vary at two positions, the molecule will still be able to bind to the dystrophin pre-mRNA to cause exon skipping. Preferably, the base sequence of the molecule varies from the selected sequence at one base position and, more preferably, the base sequence does not vary from the selected sequence. The less that the base sequence of the molecule varies from the selected sequence, the more efficiently it binds to the specific exon region in order to cause exon skipping.
The molecule is at least 25 bases in length. Preferably, the molecule is at least 28 bases in length. Preferably, the molecule is no more than 35 bases in length and, more preferably, no more than 32 bases in length. Preferably, the molecule is between 25 and 35 bases in length, more preferably, the molecule is between 28 and 32 bases in length, even more preferably, the molecule is between 29 and 31 bases in length, and most preferably, the molecule is 30 bases in length. It has been found that a molecule which is 30 bases in length causes efficient exon skipping. If the molecule is longer than 35 bases in length, the specificity of the binding to the specific exon region is reduced. If the molecule is less than 25 bases in length, the exon skipping efficiency is reduced.
The molecule may be conjugated to or complexed with various entities. For example, the molecule may be conjugated to or complexed with a targeting protein in order to target the molecule to muscle tissue. Alternatively, the molecule may be complexed with or conjugated to a drug or another compound for treating DMD. If the molecule is conjugated to an entity, it may be conjugated directly or via a linker. In one embodiment, a plurality of molecules directed to exon skipping in different exons may be conjugated to or complexed with a single entity. Alternatively, a plurality of molecules directed to exon skipping in the same exon may be conjugated to or complexed with a single entity. For example, an arginine-rich cell penetrating peptide (CPP) can be conjugated to or complexed with the molecule. In particular, (R-Ahx-R)(4)AhxB can be used, where Ahx is 6-aminohexanoic acid and B is beta-alanine [35], or alternatively (RXRRBR)2XB can be used [36]. These entities have been complexed to known dystrophin exon-skipping molecules which have shown sustained skipping of dystrophin exons in vitro and in vivo.
In another aspect, the present invention provides a vector for ameliorating DMD, the vector encoding a molecule of the invention, wherein expression of the vector in a human cell causes the molecule to be expressed. For example, it is possible to express antisense sequences in the form of a gene, which can thus be delivered on a vector. One way to do this would be to modify the sequence of a U7 snRNA gene to include an antisense sequence according to the invention. The U7 gene, complete with its own promoter sequences, can be delivered on an adeno-associated virus (AAV) vector, to induce bodywide exon skipping. Similar methods to achieve exon skipping, by using a vector encoding a molecule of the invention, would be apparent to one skilled in the art.
The present invention also provides a pharmaceutical composition for ameliorating DMD, the composition comprising a molecule as described above or a vector as described above and any pharmaceutically acceptable carrier, adjuvant or vehicle.
Pharmaceutical compositions of this invention comprise any molecule of the present invention, and pharmaceutically acceptable salts, esters, salts of such esters, or any other compound which, upon administration to a human, is capable of providing (directly or indirectly) the biologically active molecule thereof, with any pharmaceutically acceptable carrier, adjuvant or vehicle. Pharmaceutically acceptable carriers, adjuvants and vehicles that may be used in the pharmaceutical compositions of this invention include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, polyethylene glycol and wool fat.
The pharmaceutical compositions of this invention may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally, intradermally or via an implanted reservoir. Oral administration or administration by injection is preferred. The pharmaceutical compositions of this invention may contain any conventional non-toxic pharmaceutically-acceptable carriers, adjuvants or vehicles. The term parenteral as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intra-articular, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques. Preferably, the route of administration is by injection, more preferably, the route of administration is intramuscular, intravenous or subcutaneous injection and most preferably, the route of administration is intravenous or subcutaneous injection.
The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are mannitol, water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose, any bland fixed oil may be employed including synthetic mono- or diglycerides. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions may also contain a long-chain alcohol diluent, dispersant or similar alcohol.
The pharmaceutical compositions of this invention may be orally administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, and aqueous suspensions and solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are administered orally, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavouring and/or colouring agents may be added.
The pharmaceutical compositions of this invention may also be administered in the form of suppositories for rectal administration. These compositions can be prepared by mixing a compound of this invention with a suitable non-irritating excipient which is solid at room temperature but liquid at the rectal temperature and therefore will melt in the rectum to release the active components. Such materials include, but are not limited to, cocoa butter, beeswax and polyethylene glycols.
Topical administration of the pharmaceutical compositions of this invention is especially useful when the desired treatment involves areas or organs readily accessible by topical application. For application topically to the skin, the pharmaceutical composition should be formulated with a suitable ointment containing the active components suspended or dissolved in a carrier. Carriers for topical administration of the compounds of this invention include, but are not limited to, mineral oil, liquid petroleum, white petroleum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, the pharmaceutical composition can be formulated with a suitable lotion or cream containing the active compound suspended or dissolved in a carrier. Suitable carriers include, but are not limited to, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. The pharmaceutical compositions of this invention may also be topically applied to the lower intestinal tract by rectal suppository formulation or in a suitable enema formulation. Topically-transdermal patches are also included in this invention.
The pharmaceutical compositions of this invention may be administered by nasal aerosol or inhalation. Such compositions are prepared according to techniques well-known in the art of pharmaceutical formulation and may be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art.
In one embodiment, the pharmaceutical composition may comprise a plurality of molecules of the invention, each molecule directed to exon skipping in a different exon. Alternatively, the pharmaceutical composition may comprise a plurality of molecules of the invention, each molecule directed to exon skipping in the same exon.
In another embodiment, the pharmaceutical composition may comprise a plurality of vectors of the invention, each vector encoding a molecule directed to exon skipping in a different exon. Alternatively, the pharmaceutical composition may comprise a plurality of vectors of the invention, each vector encoding a molecule directed to exon skipping in the same exon.
In yet another embodiment, the pharmaceutical composition may comprise a molecule and a vector, wherein the molecule and the molecule encoded by the vector are directed to exon skipping in the same or different exons.
The present invention also provides a molecule of the invention for use in therapy.
Further, the present invention provides a molecule of the invention for use in the amelioration of DMD.
The molecules of the present invention cause exon skipping in the dystrophin pre-mRNA. This causes a truncated but functional dystrophin protein to be expressed which results in a syndrome similar to Becker muscular dystrophy (BMD). Therefore, the symptoms of DMD will not be completely treated but will be ameliorated so that they are potentially no longer life threatening.
The present invention also provides a method of ameliorating DMD in a human patient, the method comprising administering a therapeutically effective amount of the molecule of the invention to the patient.
The particular molecule that is administered to the patient will depend on the location of the mutation or mutations present in the dystrophin gene of the patient. The majority of patients have deletions of one or more exons of the dystrophin gene. For example, if a patient is missing exon 44, the process of joining exon 43 to exon 45 will destroy the protein, thus causing DMD. If exon 45 is skipped using a molecule of the invention, the joining of exon 43 to exon 46 will restore the protein. Similarly, a patient with a deletion of exon 45 can be treated with a molecule to skip either exon 44 or exon 46. Further, a patient with a deletion of exons 45 to 52 inclusive (a large portion of the gene), would respond to skipping of exon 53.
In another aspect, the invention provides a kit for the amelioration of DMD in a patient, the kit comprising a molecule of the invention and instructions for its use. In one embodiment, the kit may contain a plurality of molecules for use in causing exon skipping in the same exon or a plurality of exons.
EXAMPLES
Example 1
Here, the first detailed study of the role that AO target site variables have on the efficacy of PMOs to induce skipping is reported. The results reported here should have an impact on the initial planning and design of AOs for future potential clinical trials.
Materials and Methods
Hybridization Analyses
Templates for the production of synthetic pre-mRNAs for exons 44, 45, 46, 51, and 53 of the human dystrophin gene (DMD gene) were generated by PCR amplification from genomic clones of the exons, together with approximately 500 nt of upstream and downstream introns. PCR primers incorporated T7 RNA polymerase promoter sequences, such that pre-mRNAs could be produced by in vitro transcription. Pre-mRNAs were then subjected to a hybridization screen against a spotted array of all 4096 possible hexanucleotide sequences (Access Array 4000; Nyrion Ltd, Edinburgh UK). Binding of the pre-mRNA to specific spots on the array was detected by reverse transcriptase-mediated incorporation of biotinylated nucleotides by primer extension, followed by fluorescent labelling. Scanning of the arrays followed by software analysis enabled sequences within the exons that were accessible to binding to the hexamer array to be identified. Using a hybridization assay, binding accessibility of each exons were analysed and hybridization peak identified by AccessMapper software (Nyrion Ltd) (see FIG. 1 d ).
AO Design
Overlapping AOs were designed to exons 44, 45, 46, 51, and 53 of the human DMD gene using the following information: putative SR protein binding domains as predicted by ESEfinder [20, 21], Rescue ESE [24] and PESX [22, 23] analyses of exon sequence; sequences accessible to binding as determined by hybridization analyses (Nyrion); previously published work [18, 19].
All AOs were synthesized as phosphorodiamidate morpholino oligos (PMOs) by Gene Tools LLC (Philomath Oreg., USA). To facilitate transfection of these uncharged oligonucleotides into cultured cells, the PMOs were hybridized to phosphorothioate-capped oligodeoxynucleotide leashes, as described by Gebski et al., [12], and stored at 4° C.
The sequences of some of these PMOs were as follows:
H44A30/1 - (SEQ ID NO: 13) TGA AAA CGC CGC CAT TTC TCA ACA GAT CTG; H44A30/2 - (SEQ ID NO: 14) CAT AAT GAA AAC GCC GCC ATT TCT CAA CAG; H44AB30/2 - (SEQ ID NO: 15) TGT TCA GCT TCT GTT AGC CAC TGA TTA AAT; H45A30/2 - (SEQ ID NO: 16) CAG TTT GCC GCT GCC CAA TGC CAT CCT GGA; H45A30/1 - (SEQ ID NO: 17) TTG CCG CTG CCC AAT GCC ATC CTG GAG TTC; H46A30/2 - (SEQ ID NO: 18) TGC TGC TCT TTT CCA GGT TCA AGT GGG ATA; H46A30/4 - (SEQ ID NO: 19) CTT TTA GTT GCT GCT CTT TTC CAG GTT CAA; H46A30/5 - (SEQ ID NO: 20) CTT TTC TTT TAG TTG CTG CTC TTT TCC AGG; H46A30/3 - (SEQ ID NO: 21) TTA GTT GCT GCT CTT TTC CAG GTT CAA GTG; H53A30/2 - (SEQ ID NO: 22) CTG TTG CCT CCG GTT CTG AAG GTG TTC TTG; H53A30/3 - (SEQ ID NO: 23) CAA CTG TTG CCT CCG GTT CTG AAG GTG TTC; H53A30/1 - (SEQ ID NO: 24) TTG CCT CCG GTT CTG AAG GTG TTC TTG TAC.
Cell Culture and AO Transfection
Normal human primary skeletal muscle cells (TCS Cellworks, Buckingham, UK) were seeded in 6-well plates coated with 0.1 mg/ml ECM Gel (Sigma-Aldrich, Poole, UK), and grown in supplemented muscle cell growth medium (Promocell, Heidelberg, Germany). Cultures were switched to supplemented muscle cell differentiation medium (Promocell) when myoblasts fused to form visible myotubes (elongated cells containing multiple nuclei and myofibrils). Transfection of PMOs was then performed using the transfection reagent Lipofectin (Invitrogen, Paisley, UK) at a ratio of 4 μl of Lipofectin per μg of PMO (with a range of PMO concentrations tested from 50 to 500 nM, equivalent to approximately 0.5 to 5 μg) for 4 hrs, according to the manufacturer's instructions. All transfections were performed in triplicate in at least two different experiments.
RNA Isolation and Reverse Transcriptase-Polymerase Chain Reaction Analysis
Typically 24 h after transfection, RNA was extracted from the cells using the QIAshredder/RNeasy system (Qiagen, Crawley, UK) and ˜200 ng RNA subjected to RT-PCR with DMD exon-specific primers using the GeneScript kit (Genesys, Camberley, UK). From this 20 cycle reaction, an aliquot was used as a template for a second nested PCR consisting of 25 cycles. PCR products were analysed on 1.5% agarose gels in Tris-borate/EDTA buffer. Skipping efficiencies were determined by quantification of the PCR products by densitometry using GeneTools software (Syngene, Cambridge, UK).
Statistical Analysis
The non-parametric Mann-Whitney rank sum test was used to identify whether parameters for effective PMOs were significantly different to those for ineffective PMOs. Where data was calculated to fit a normal distribution, the more powerful two-tailed Student's t-test was performed instead. Correlations were generated using the Spearman rank-order test. To determine the strength of the combined significant parameters/design tools to design effective PMOs, linear discriminant analysis was used [34], with the Ida function from the MASS package, using “effective” or “ineffective” as the two prior probabilities. The Ida function produces posterior probabilities for the two classes (effective and ineffective) for each PMO by leave-one-out classification.
Results
PMO Design and Analysis of Bioactivity
A unique set of 66 PMOs has been designed to target exons 44, 45, 46, 51, and 53 of the human gene for dystrophin. The design process for exon 53 is depicted in FIG. 1 , and has also been performed for the other four exons (data not shown). The exon sequence was analysed for the presence of exonic splicing enhancers (ESE) and exonic splicing suppressors or silencers (ESS) and the outputs aligned for the three available algorithms, ESEfinder ( FIG. 1 a ) [20, 21], PESX ( FIG. 1 b ) [22, 23], and Rescue ESE ( FIG. 1 c ) [24]. Hybridization array analysis was also performed for each exon in vitro, as described in Materials and Methods. The peaks shown in FIG. 1 d indicate areas of the exon that are in a conformation able to hybridize to the array, and which may consequently prove more accessible to antisense AOs. The coincidence of ESEs, as predicted by two or more algorithms, and hybridization peaks determined experimentally, was used to design arrays of 25 mer and, subsequently, 30 mer PMOs, the positions of which are shown in FIG. 1 f . The binding sites for 2′OMePS AOs described previously [18] are shown for comparison ( FIG. 1 e ).
Each PMO was tested in primary cultures of human skeletal muscle, in triplicate, in at least two experiments, and over a range of concentrations from 50 nM to 500 nM. Their bioactivity was determined by RT-PCR analysis, which showed a wide variation in the level of exon skipping induced ( FIG. 2 , and data not shown), ranging from 0% for h53C1 ( FIG. 1 f and FIG. 2 , lane 2) to 80% for h53A30/3 ( FIG. 1 f and FIG. 2 , lane 6). Sequencing of the PCR products verified accurate skipping of the targeted exon (data not shown). The activity of each PMO at the stated optimal concentration is summarized in Table 1. Bioactivity is expressed as a percentage of the skipped amplicon relative to total PCR product, as assessed by densitometry. Specific, consistent and sustained exon skipping was evident for 44 of the 66 PMOs tested.
In Silico Analysis of PMOs
We then performed a retrospective in silico analysis of the characteristics of all 66 PMOs tested in this study, with respect to PMO length, the distance of the PMO target site from the splice donor and acceptor sites, PMO-to-target binding energy and PMO-to-PMO binding energy, as calculated using RNAstructure2.2 software for the equivalent RNA-RNA interaction, and percentage GC content of the PMO, the results of which are summarized in Table 1. Also shown in Table 1 is the percentage overlap of each PMO target site with sequences shown to be accessible to binding, as determined experimentally by the hexamer hybridization array analysis. The relationship of PMO target site and RNA secondary structure was also examined using the program MFOLD [25] ( FIG. 3 and data not shown), with the percentage overlap of PMO target site with sequence predicted to be in open conformation by MFOLD analysis given in Table 1. ESEfinder and SSF (http://www.umd.be/SSF/) software analysis of exon sequences revealed the positions of putative SR protein binding motifs (SF2/ASF (by two algorithms), SC35, SRp40, SRp55, Tra2β and 9G8). The highest score over threshold for each SR protein is given for each PMO in the columns on the right of Table 1. Also shown is the degree of overlap of each PMO target site with the ESE and ESS regions predicted by Rescue ESE and PESX.
Statistical Analysis of Design Parameters in Relation to PMO Bioactivity
For this statistical analysis, bioactive PMOs are considered to be those which produce over 5% skipping, while those that produce less than 5% skipping are considered inactive. For each of the parameters listed in Table 1, comparison was made between bioactive and inactive PMOs using the non-parametric Mann-Whitney rank sum test, or, when it was statistically valid to do so, the parametric Student's t-test (two-tailed). The significant parameters are listed in Table 2. Considering the data as a whole, the variable which showed the highest significance to PMO bioactivity was the binding energy of the PMO to the exon (p=0.001); the most bioactive exons are predicted to bind better to their target sites. Those PMOs that overlap with peaks identified by the experimental hybridization array analysis are not significantly more active than those that do not (p=0.056), but when only the strongest peak for each exon is considered, this parameter becomes highly significant (p=0.003). Distance of the PMO target site to the splice acceptor site of the exon was also highly significant (p=0.004), with PMOs whose target site were closer to the acceptor site being more active. PMOs whose target sites showed coincidence with binding motifs for the SR protein SF2/ASF (as defined by the BRCA1 algorithm of Smith et al. [21]) produced significantly greater skipping (p=0.026). PMO length is also a significant parameter (p=0.017), with longer PMOs being more effective at inducing skipping. Boxplots of the significant variables identified here are shown in FIG. 5 . None of the other variables considered in this study were shown to have any significance to AO bioactivity.
To ascertain which parameters/design tools are the most powerful, we also used the Mann-Whitney rank sum test to compare the most active PMOs (i.e. those that induce greater than 75% skipping of the target exon) to those that were inactive (i.e. those that produce less than 5% skipping). Boxplots of the significant variables for this comparison are shown in FIG. 4 . There is strong significance of overlap of the PMO target site with the strongest hybridization peak for each exon (p=0.002); more of the most bioactive PMOs had their target sites coincident with sequences accessible to binding than those that were inactive. This is reinforced by the observation that the target sites of PMOs that produced over 75% skipping significantly overlapped more RNA that was in open conformation, relative to inactive PMOs (p=0.025). Stronger binding between the PMO and its target exon, PMO length, and proximity of the target to the acceptor site are also significant parameters when comparing the most and least effective reagents.
Spearman's rank order correlation was used to establish potential relationships between design parameters and skipping bioactivity using the entire set of PMOs. This shows a strong correlation between skipping bioactivity and PMO-target binding energy (r s =−0.618, p=0), percentage open conformation (r s =0.275, p=0.0259), PMO length (r s =0.545, p=0), distance from the splice acceptor site (r s =−0.421, p=0), percentage overlap with the strongest hybridization peak (r s =0.46, p=0), and overlap with an ESS sequence, as predicted by PESX (r s =0.261, p=0.0348).
Linear Discriminant Analysis
This analysis was performed on all possible combinations of length, overlap with the SF2/ASF (BRCA1) motif, percentage overlap with areas of open conformation, percentage overlap with hybridization peak and PMO-target binding energy, i.e. PMO parameters and design tools that showed significance or borderline significance. Using length, SF2/ASF (BRCA1) motif and hybridization peak data, nine of the inactive PMOs were classified as bioactive and four bioactive PMOs were classified as inactive (Table 3). These four misclassified PMOs were 25 mers to exon 46, three of which have borderline bioactivity, i.e. produce just 10% skipping, while the fourth produces about 20% skipping. Taken overall, this equates to 80% of the PMOs being predicted correctly when assessed according to their length, SF2/ASF (BRCA1) overlap and hybridization peak overlap. This would suggest that these parameters have the potential to be effective design tools, with four out of every five PMOs designed to have these three properties likely to be bioactive. In line with this, there was a distinct trend for PMOs being correctly assigned as bioactive with increased skipping bioactivity (see Table 3). Indeed, the PMOs with greatest bioactivity were all 30 mers (10/10), bound to their target with a high binding energy of below −43.0 kD (9/10), overlapped by over 50% with areas of open conformation (7/10), overlapped with SF2/ASF (BRCA1) peak (8/10), and overlapped with a hybridization peak (7/10).
Discussion
Clinical studies using AOs to skip exon 51 to correct DMD deletions are progressing well [11; F. Muntoni, Principal Investigator of MDEX Consortium, personal communication]. However since the mutations that cause DMD are so diverse, skipping of exon 51 would have the potential to treat just 24.6% of DMD patients on the Leiden DMD database [26]. It is therefore imperative that pre-clinical optimization of AO target sequence and chemistry is continually studied and improved. This study has examined the significance of design parameters for PMO-induced skipping of exons 44, 45, 46, 51, and 53, which would have the potential to treat, respectively, 11.5%, 15.8%, 8.4%, 24.6% and 13.5% of DMD patients in the Leiden database [26; A. Aartsma-Rus, personal communication].
Specific skipping was observed for the five DMD exons studied here, with two-thirds of the PMOs tested being bioactive. This proportion of bioactive AOs within a cohort has been reported previously [18, 19], but we have induced high-level (i.e. greater than 75%) skipping in four of the five exons tested, some of which are achievable at relatively low doses of oligomer. The exception is exon 51, published previously [4], achieving a maximal skipping of 26%. The work of Wilton et al [19] demonstrated that only exons 51 and 53 can be skipped with high efficiency (>30% by their definition), and that exons 44, 45 and 46 are less “skippable” (less than 30% skipping). Furthermore, Aartsma-Rus et al [18] showed oligomers capable of high-level skipping (greater than a mere 25%) for only exons 44, 46 and 51.
We provide here direct evidence that AO bioactivity shows a significant association with accessibility of its target site to binding. This is the first study to assess sequences practically within the pre-mRNA that are accessible to binding and then use them as an aid to AO design. The data we show underline the value of the hybridization analysis in determining what are likely to be the most bioactive oligomers (i.e. those that produce greater than 75% skipping). As an example, if we look at the data for oligomers developed for exon 45 [18], we see that there is only one moderately effective (5-25%) reagent for this otherwise unskippable exon. This oligomer is the only one of the six tested that overlaps with the strongest peak in our hybridization analysis. The partial nature of this overlap, combined with the short length of the oligomer, is likely to contribute to its relative weakness compared to the PMOs we have developed here. In general, the 2′OMePS AOs displaying the highest bioactivity in the work of Aartsma-Rus et al. [18] and Wilton et al. [19], show some degree of overlap with the hybridization peaks that we have defined here for exons 45, 46 and 53.
Ease of skipping of certain DMD exons has been seen elsewhere [18] and may be related to other factors affecting splicing, including strength of splice donor and acceptor sites and branchpoint, and the size of upstream and downstream introns, which may affect the order in which exons are spliced together. There is the potential of using a cocktail of AOs to induce greater skipping of the more difficult to skip exons [27, 28].
Accessibility of the AO to its target site depends directly on the secondary structure of the pre-mRNA, which has a major role in determining AO bioactivity in cells. A study in which the structure around an AO target site was changed revealed that AOs were unable to invade very stable stem-loop structures and their antisense activity was inhibited, but generally showed good activity when impeded by little local structure [29]. Overlap of PMO target sites with open conformations in the folded RNA showed a weak association with PMO bioactivity, which was more obvious when only the stronger PMOs were considered in the statistical analysis. It is also possible that there is selective pressure for SR binding sites to be located preferentially on these open secondary structures. The presumption is that binding of bioactive PMOs to their target sites sterically block the binding of important factors involved in RNA processing, resulting in exon skipping.
One of the PMO parameters with high significance was length; 30 mer PMOs were far superior to their 25 mer counterparts. The influence of 2′OMePS AO length on bioactivity has been reported elsewhere [30] and such an observation for PMO-induced skipping of exon 51 has been reported previously by us [4]. The more persistent action of longer PMOs would have important cost and dose implications in the choice of AO for clinical trials. Longer AOs are likely to sterically block more of the regions that interact with the splicing machinery, but in general terms, the energy of binding of the longer PMO to its target would be increased, which we showed to be the most significant parameter in AO design. The strong significance of the binding energy of PMO-target complexes (i.e., free energy of AO-target compared to free energy of the target) and PMO length to bioactivity suggests that PMO bioactivity depends on stability of the PMO-target complex, and implies that bioactive PMOs act by interference of target RNA folding. Computational analysis revealed that the thermodynamics of binding of active PMOs to their target site had a dramatic effect on the secondary folded structure of the RNA (data not shown). It is likely that these changes in secondary structure would have a profound effect on the binding of SR proteins to the RNA, thereby disrupting splicing, and exon skipping would ensue.
Overlap of a PMO target site with a binding site motif for the SR protein SF2/ASF (BRCA1), as predicted by ESEfinder, showed a significant association to PMO bioactivity. This partly confirms the work of Aartsma-Rus et al. [18], who observed marginally significantly higher ESEfinder values for SF2/ASF and SC35 motifs for effective AOs when compared to inactive AOs. SC35 and SF2/ASF motifs are the two most abundant proteins assessed by ESEfinder. The reason why we do not see any significance of overlap with SC35 motif to PMO bioactivity may be due to the difference in AO chemistry used, and the number of AOs assessed. However Aartsma-Rus et al. [18] did note that not every bioactive AO has a high value for any of the SR protein binding motifs, and some inactive AOs have high values. The apparent weakness and unreliability of SR protein binding motifs as design tools for AOs may be a reflection of the lack of precision of the predictive software used. Overlap of PMO target site with exonic splicing silencers appears to show a correlation with bioactivity in Spearman's rank order test analysis. Such a correlation would be counter-intuitive and the true significance questionable. Again the strength of the predictive software used may be in doubt. It should be noted that the software programmes used predict SR binding motifs on the linear exon sequence. The availability of these predicted motifs to bind SR proteins, or for binding PMOs to disrupt the binding of these proteins, is directly related to the folding of the pre-mRNA. The discrepancy in the relative significance of secondary RNA structure and SR protein binding motifs may be due to active PMOs disrupting SR protein binding, not sterically but indirectly, by altering the secondary pre-mRNA structure. A very recent study has shown the importance of co-transcriptional pre-mRNA folding in determining the accessibility of AO target sites and their effective bioactivity, and showed a direct correlation between AO bioactivity and potential interaction with pre-mRNA [31].
It has been previously reported that ESE sites located within 70 nucleotides of a splice site are more active than ESE sites beyond this distance [32]. Our results partially support this; PMOs with their target site closer to the splice acceptor site are significantly more bioactive. However distance of the PMO target site to the splice donor site showed no statistical significance to bioactivity. This bias has been previously reported for the analyses of 2′OMePS AOs [18, 19], and may be related to the demonstration, by Patzel et al. [33], of the importance of an unstructured 5′ end of RNA in the initiation of hybridization of oligonucleotide binding. This would suggest that targeting any significant parameters located in the 5′ part of an exon may increase the probability of designing a bioactive AO.
In conclusion, our findings show that no single design tool is likely to be sufficient in isolation to allow the design of a bioactive AO, and empirical analysis is still required. However this study has highlighted the potential of using a combination of significant PMO parameters/design tools as a powerful aid in the design of bioactive PMOs. Linear discriminant analysis revealed that using the parameters of PMO length, overlap with SF2/ASF (BRCA1) motif and hexamer array hybridization data in combination would have an 80% chance of designing a bioactive PMO, which is an exciting and suprising finding, and should be exploited in further studies.
TABLE 1
Table 1: Table summarizing the characteristics of PMOs used
PMOs are ranked in order of efficacy and characteristics of the PMOs and their target
sites listed.
Targeted
Optimal
%
Exon-PMO
PMO-PMO
Ends in open
Distance from
PMO
exon
conc.
Skip a
Length
% GC
binding energy
binding energy
% open b
loops b
donor
acceptor
h53B1
53
500
0
25
28
−22.1
−12.1
53.3
1
119
68
h53C1
53
500
0
25
48
−32.4
−9.8
46.7
2
79
108
h53C2
53
500
0
25
56
−31.3
−12.7
33.3
1
72
115
h53C3
53
500
0
25
60
−34.6
−13.7
26.7
1
60
127
h53D1
53
500
0
25
52
−34.1
−13.4
30
1
39
148
h45A30/4
45
500
0
30
43
−35.2
−7.5
40
1
53
93
h45A30/6
45
500
0
30
53
−42.4
−26.9
46.7
2
9
137
h46A10
46
500
0
25
40
−35.3
−1.7
23.3
1
63
60
h46A30/6
53
500
0
30
40
−42.1
−10.1
56.7
0
5
113
h53D2
46
500
0.1
25
48
−36.5
−14.5
40
2
30
157
h46A5
53
500
0.2
25
36
−33.9
−7.9
53.3
0
10
113
h53A6
53
500
0.3
25
48
−35.3
−8.5
43.3
2
138
49
h53B2
53
500
0.6
25
48
−30.1
−11.3
23.3
1
108
79
h46A11
46
500
0.6
25
20
−24.5
−1.5
43.3
0
0
143
h46A30/8
46
500
1.5
30
30
−34.2
−1.8
46.7
0
0
136
h45A30/7
45
500
1.6
30
50
−46.1
−4.7
73.3
0
0
158
h45A30/8
45
500
1.6
30
40
−39.3
−13.7
53.3
1
76
70
h53A3
53
500
2
25
56
−36.7
−13.7
36.7
0
147
40
h46A9
46
500
2.1
25
28
−31.5
−7.6
36.7
1
109
14
h53B3
53
500
3
25
48
−34.5
−5.5
48
2
98
89
h53D3
53
500
3.7
25
36
−34.3
−11.2
40
1
18
169
h44B30/8
44
500
4.6
30
37
−28.3
−23.5
40
1
34
84
h44B30/4
44
50
5
30
43
−38.2
−14.6
40
0
54
64
h46A6
46
100
5.4
25
36
−31.5
−8
46.7
1
0
123
h46A8
46
500
5.4
25
32
−28.6
0
20
1
76
47
h45A30/3
45
500
6.3
30
40
−35.5
−11.8
60
1
108
38
h53D5
53
500
7.9
25
36
−31.5
−3.3
66.7
1
0
187
h46A1
46
100
8.3
25
48
−35.7
−11.9
53.3
1
38
85
h53A5
53
250
9
25
48
−35.5
−8.5
43.3
2
141
46
h46A7
46
500
9.1
25
32
−34.8
−5.6
36.7
1
123
0
h53A30/5
53
100
9.4
30
47
−42.4
−11.3
46.7
1
141
41
h53A2
53
100
9.7
25
56
−36.1
−17.4
46.7
1
150
37
h53A4
53
500
10.5
25
48
−34.3
−8.5
20
0
144
43
h45A30/5
45
500
11.2
30
63
−44
−21.1
26.7
0
17
129
h53D4
53
500
12.3
25
32
−30.9
−9.2
63.3
1
6
181
h53A1
53
100
12.7
25
52
−38.6
−17.4
50
2
153
34
A25
51
250
14.9
25
36
−29.3
−11.6
66.7
2
146
62
h46A2
46
500
15.6
25
44
−31.2
−10.6
56.7
1
33
90
h46A30/7
46
500
18.5
30
30
−34.2
−6.2
53.3
1
0
141
h46A4
46
100
21.2
25
44
−39.9
−6.3
56.7
2
20
103
h44C30/2
44
50
22
30
33
−38
−7.4
36.7
1
7
111
h44B30/7
44
100
26
30
37
−33.9
−10.9
26.7
1
39
79
h51A
51
500
26.3
30
43
−40.3
−15
70
1
137
65
h44B30/6
44
500
32.5
30
37
−34.6
−9.6
30
2
44
74
h44C30/3
44
500
35
30
33
−38.9
−13.8
30
1
2
116
h44B30/1
44
100
35
30
33
−35.2
−7.1
66.7
1
69
49
h53A30/6
53
500
35.9
30
47
−42.3
−8.5
56.7
1
138
44
h53A30/4
53
100
38.6
30
50
−43.4
−17.4
43.3
1
144
38
h44C30/1
44
100
42
30
37
−41.1
−10.4
50
1
12
106
h46A3
46
100
49.7
25
48
−43.1
−5.2
56.7
2
28
95
h44A30/3
44
250
52.1
30
37
−42.5
−8.6
56.7
1
99
19
h53A30/1
53
100
52.4
30
50
−48.1
−17.4
56.7
1
153
29
h44B30/3
44
500
61
30
43
−35.4
−11.4
30
0
59
59
h44B30/5
44
500
63.3
30
40
−35.9
−14.6
30
1
49
69
h45A30/1
45
500
64.5
30
60
−49.7
−11
36.7
1
146
0
h46A30/3
46
500
74.6
30
43
−49.8
−6.3
73.3
2
23
95
h46A30/1
46
500
75.6
30
47
−43.5
−12.3
63.3
0
33
85
h46A30/5
46
500
76.7
30
40
−49.2
−6.3
70
1
15
103
h53A30/3
53
100
80.1
30
53
−44.6
−17.4
53.3
1
147
35
h44B30/2
44
500
80.5
30
37
−36.9
−10.7
50
1
64
54
h53A30/2
53
100
87.2
30
53
−45.1
−17.4
63.3
1
150
32
h46A30/4
46
500
87.3
30
40
−47.5
−6.3
73.3
2
20
98
h46A30/2
46
500
87.9
30
47
−49.1
−13.4
63.3
2
28
90
h45A30/2
45
500
91.4
30
60
−46.6
−13
20
1
142
4
h44A30/2
44
500
95
30
43
−44
−8.6
40
0
104
14
h44A30/1
44
250
97
30
47
−47.5
−11.2
46.7
1
109
9
% overlap
% overlap with
# Rescue
% overlap with
with
ESE finder values over threshold c
PMO
hybrid peak
ESE sites
Rescue ESE
PESE
PESS
SF2/ASF
BRCA1
SC35
SRp40
SRp55
Tra2B
9G8
h53B1
0
5
56
40
40
0
9.26
3.62
10.66
0
5.06
1.1
h53C1
0
6
52
72
0
4.19
6.72
0
2.04
0
24.04
28.68
h53C2
0
1
24
60
0
4.19
6.72
10.2
4.38
0
0
8.28
h53C3
0
1
24
32
0
3.49
6.41
10.2
4.38
6.86
0
14.18
h53D1
0
4
40
32
0
0.52
0
18.68
0.42
0
0
12.71
h45A30/4
100
4
40
0
0
6.29
4.8
5.9
17.91
0
18.18
8.14
h45A30/6
100
4
40
0
0
11.64
7.34
5.04
1.38
0
7.25
16.53
h46A10
0
7
60
48
8
2.21
0
2.7
2.88
0
5.11
23.85
h46A30/6
0
7
40
50
0
0
0
0
5.09
0
24.04
6.94
h53D2
0
6
44
32
0
0.52
1.8
18.68
0.42
0
0
12.71
h46A5
0
7
48
44
0
0
0
0
5.09
0
24.04
6.94
h53A6
92
2
36
28
32
6.58
7.26
0
0
0
7.25
11.9
h53B2
0
5
60
60
0
0
9.26
3.62
4.73
0
5.06
8.28
h46A11
0
2
36
12
52
0
0
0
1.02
0
0
2.04
h46A30/8
0
1
27
27
43
0
0
0
1.02
0
0
2.04
h45A30/7
100
9
47
0
0
6.34
7.34
0
0.6
0
18.18
8.14
h45A30/8
100
4
47
0
0
0
0
5.9
2.4
0
18.18
17.14
h53A3
0
3
32
60
0
6.58
7.26
0
3.12
0
7.25
11.9
h46A9
0
8
48
25
0
0
7.87
0
0
0
24.04
7.14
h53B3
0
8
72
64
0
3.49
9.26
3.44
4.73
0
24.04
28.68
h53D3
0
9
64
0
0
0
1.8
0
6.95
0
24.04
10.49
h44B30/8
0
7
57
27
13
2.85
8.64
7.06
1.38
0
10.92
19.02
h44B30/4
0
8
47
37
27
1.98
8.64
6.14
10.12
0
7.25
8.28
h46A6
0
7
72
64
0
0
0
0
5.09
0
24.04
6.94
h46A8
0
5
56
24
60
2.21
0
3.56
2.88
0
0
23.68
h45A30/3
100
9
87
30
0
0
6.18
3.07
4.73
0.45
24.04
28.68
h53D5
0
14
92
44
0
8.5
11.95
0
7.67
0.33
24.04
7.14
h46A1
100
3
20
40
0
2.62
20.26
6.63
6.17
0
0
5.12
h53A5
100
3
36
36
20
6.58
7.26
0
3.12
0
7.25
11.9
h46A7
0
9
64
44
0
0
0
6.02
4.2
0
24.04
28.68
h53A30/5
100
5
47
47
17
6.58
7.26
0
3.12
0
7.25
11.9
h53A2
100
4
32
72
0
6.58
7.26
0
3.12
0
7.25
19.02
h53A4
100
4
28
48
8
6.58
7.26
0
3.12
0
7.25
11.9
h45A30/5
100
2
23
0
0
11.64
13.49
5.04
1.38
0
7.25
16.53
h53D4
0
16
96
24
0
8.5
11.95
0
7.67
0.33
24.04
7.14
h53A1
92
7
56
84
0
6.58
7.26
0
3.12
0
24.04
19.02
A25
0
1
24
12
32
1.22
13.72
0
0
0
0
0
h46A2
100
5
40
40
0
2.62
20.26
6.63
6.17
0
13.11
5.12
h46A30/7
0
2
20
10
43
0
0
0
1.02
0
0
2.1
h46A4
46
8
60
40
0
0
0
0
5.09
0
24.04
6.94
h44C30/2
0
3
33
10
63
0.52
5.72
0
0
0
9.46
5.6
h44B30/7
0
6
40
30
27
2.85
8.64
7.06
1.38
0
10.92
19.02
h51A
0
2
40
3
27
1.22
13.72
0
0
0
0
4.45
h44B30/6
0
8
37
20
27
2.85
8.64
0
1.92
0
10.92
19.02
h44C30/3
0
2
33
0
63
0
0
0
6.44
0
9.46
5.6
h44B30/1
0
6
67
33
30
0
0
6.14
10.12
0
10.92
8.28
h53A30/6
100
5
48
37
27
6.58
7.26
0
3.12
0
7.25
11.9
h53A30/4
100
4
43
57
7
6.58
7.26
0
3.12
0
7.25
11.9
h44C30/1
0
3
43
27
63
0.52
5.72
7.06
0
0
9.46
5.6
h46A3
100
5
40
40
0
2.62
20.26
6.63
6.17
0
13.11
5.12
h44A30/3
0
3
23
0
77
0
13.26
0
0
0
0
11.3
h53A30/1
92
9
60
86
0
6.58
7.26
0
3.12
0
24.04
19.02
h44B30/3
0
5
47
37
33
0
0
6.14
10.12
0
7.25
8.28
h44B30/5
0
10
63
37
27
1.98
8.64
6.14
1.92
0
10.92
19.02
h45A30/1
100
2
0
0
6.7
3.43
8.64
5.16
3.54
3.57
0
20.56
h46A30/3
100
5
40
33
0
0
0.57
0
6.17
0
13.11
5.12
h46A30/1
100
5
33
33
0
2.62
20.26
6.63
6.17
0
13.11
5.12
h46A30/5
46
12
67
50
0
0
0
0
5.09
0
24.04
6.94
h53A30/3
100
6
43
67
0
6.58
7.26
0
3.12
0
24.04
19.02
h44B30/2
0
5
50
37
37
0
0
6.14
10.12
0
7.25
8.28
h53A30/2
100
8
53
77
0
6.58
7.26
0
3.12
0
24.04
19.02
h46A30/4
85
8
50
43
0
0
0.57
0
5.09
0
24.04
5.12
h46A30/2
100
5
33
33
0
2.62
20.26
6.63
6.17
0
13.11
5.12
h45A30/2
100
0
0
0
20
3.43
10.41
5.16
3.54
3.57
0
20.56
h44A30/2
0
3
27
0
63
0
13.26
0
0
0
0
11.3
h44A30/1
0
4
43
0
47
0
13.26
0
2.76
0
0
11.3
a calculated as % skipped amplicon relative to total amplicon (i.e. skipped plus full length) as assessed by densitometric analysis of RT-PCR gels.
b calculated as % on PMO target site in open structures on predicted RNA secondary structure obtained using MFOLD analysis. The position of the PMO target sites relative to open loops in the RNA secondary structure is listed (0 = no ends in open loops, 1 = one end in an open loop, 2 = both ends in open loops).
c In analyses, SR binding sites were predicted using splice sequence finder (http://www.umd.be/SSF/) software. Values above threshold are given for PMOs whose target sites cover 50% or more of potential SR binding sites for SF2/ASF, BRCA1, SC35, SRp40, SRp55, Tra2β and 9G8.
TABLE 2
Table 2: The correlation of significant design parameters and PMO target site
properties to skipping efficacy
To establish the significance of design parameters and PMO target site properties to
bioactivity, Mann-Whitney rank sum test analysis was performed for each, comparing
ineffective (inactive) PMOs to the different groups of PMOs, subdivided (in the
column headed “Comparison”) according to bioactivity (efficacy). Criteria with p-
values less than 0.05 in one or more comparisons are shown. The correlation of these
variables to bioactivity is confirmed by Spearman rank order test analysis, for which
Spearman correlation coefficients and p-values are given.
PMO-target
% open
Distance from
% overlap with
% overlap with
% overlap with
Comparison
binding energy
conformation
Length
acceptor site
hybridisation peak
strongest hybrid. peak
BRCA1 motif
Ineffective vs Effective
0.001
0.094
0.017
0.004
0.056
0.003
0.026
Ineffective vs 5-25% skip
0.534
0.288
1
0.163
0.107
0.034
0.205
Ineffective vs 25-50% skip
0.02
0.316
0.014
0.067
0.614
0.195
0.079
Ineffective vs 50-75% skip
0.002
0.438
0.012
0.005
0.352
0.084
0.341
Ineffective vs 75-100% skip
<0.001
0.025
0.002
0.003
0.045
0.002
0.091
Ineffective vs >50% skip
<0.001
0.052
<0.001
<0.001
0.05
0.005
0.046
Spearmans correlation
−0.618
0.275
0.545
−0.421
0.258
0.46
0.261
coefficient
Spearmans p value
0
0.0259
0
0
0.0363
0
0.0341
TABLE 3
Table 3: Linear discriminant analysis of effective and ineffective PMOs
Linear discriminant analysis [34] was used to predict the classification
of PMOs on the basis of their PMO-target binding energy, overlap of
PMO target site with a hybridization peak, and overlap of PMO target
site with an ASF/SF2 (BRCA1) motif. PMOs have been grouped on the
basis of their experimental bioactivity (“Group” column), and PMOs
within each group predicted as “Effective” (bioactive) or “Ineffective”
(inactive), as indicated by the column headings, according to the
parameters used in the statistical analysis. The error rate for wrongly
classifying a PMO, and the average score are given for each
subgroup of PMO.
Classification
Average
Group
Effective
Ineffective
Total
Error rate
score
Effective
40
4
44
0.09
0.741
Ineffective
9
13
22
0.41
0.512
0-5% skip
9
13
22
0.41
0.512
5-25% skip
16
4
20
0.2
0.621
25-50% skip
9
0
9
0
0.806
50-75% skip
6
0
6
0
0.827
75-100% skip
10
0
10
3
0.857
Example 2
Here, the inventors show the comparative analysis of a series of PMOs targeted to exon 53, skipping of which would have the potential to treat a further 8% of DMD patients with genomic deletions on the Leiden database compared to skipping of exon 51 which has the potential to treat 13% of DMD patients [37]. An array of overlapping PMOs were designed for the targeting of exon 53 as described previously [38]. These were all tested initially in normal human skeletal muscle cells (hSkMCs), since these are more readily available than patient cells. PMOs that showed greatest skipping efficacy were further tested in cells from a DMD patient with a relevant deletion (del 45-52). The PMOs with greatest efficacy, in terms of concentration and stability, were evaluated by performing dose-response and time-course studies. Findings from these experiments were supported by in vivo studies in a mouse model transgenic for the entire human dystrophin locus [8]. Collectively, this work suggests that one particular PMO (A, h53A30/1, +30+59) produced the most robust skipping of exon 53, and should be considered the sequence of choice for any upcoming PMO clinical trial.
Materials and Methods
AO Design
Twenty-three overlapping AOs to exon 53 were designed as described above in Example 1.
Cell Culture and AO Transfection
Transfections were performed in two centres (Royal Holloway, London UK (RHUL) and UCL Institute of Child Health, London UK (UCL)) and by two different methods (liposome-carrier of leashed PMOs in normal cells (RHUL), and by nucleofection of naked PMOs in patient cells (UCL)). AOs were transfected into normal human primary muscle cells (TCS Cellworks, Buckingham, UK) and into patient primary skeletal muscle cultures obtained from muscle biopsies taken at the Dubowitz Neuromuscular Unit, UCL Institute of Child Health (London, UK), with the approval of the institutional ethics committee. Normal hSkMCs were cultured and transfected with leashed PMOs, using 1:4 lipofectin, as described previously [4]. To minimize any influence of leash design on PMO uptake and subsequent bioactivity, the DNA sequences in the leashes were of the same length (17 mers for the 25 mer PMOs or 20 mers for the 30 mer PMOs) and were completely complementary to the 3′-most 17 or 25 nt of each PMO. The phosphorothioate caps of 5 nt at each end were not complementary to the PMOs, and had the same sequences for every leash.
DMD Patient Primary Myoblast Culture
Skeletal muscle biopsy samples were taken from a diagnostic biopsy of the quadriceps from a DMD patient with a deletion of exons 45-52. Informed consent was obtained before any processing of samples. Muscle precursor cells were prepared from the biopsy sample by sharp dissection into 1 mm 3 pieces and disaggregated in solution containing HEPES (7.2 mg/ml), NaCl (7.6 mg/ml), KCl (0.224 mg/ml) Glucose (2 mg/ml) Phenol Red (1.1 μg/ml) 0.05% Trypsin-0.02% EDTA (Invitrogen, Paisley, UK) in distilled water, three times at 37° C. for 15 minutes in Wheaton flasks with vigorous stirring. Isolated cells were plated in non-coated plastic flasks and cultured in Skeletal Muscle Growth Media (Promocell, Heidelberg, Germany) supplemented with 10% Foetal Bovine Serum (PAA Laboratories, Yeovil, UK), 4 mM L-glutamine and 5 μg/ml gentamycin (Sigma-Aldrich, Poole, UK) at 37° C. in 5% CO 2 .
Nucleofection of DMD Primary Myoblasts
Between 2×10 5 and 1×10 6 cells/ml were pelleted and resuspended in 100 μl of solution V (Amaxa Biosystems, Cologne, Germany). The appropriate PMO to skip exon 53 was added to the cuvette provided, sufficient to give the concentrations described, followed by the cell suspension, and nucleofected using the Amaxa nucleofector 2, program B32. 500 μl of media was added to the cuvette immediately following nucleofection. This suspension was transferred to a 6 well plate in differentiation medium. Nucleofected cells were maintained in differentiation media for 3-21 days post treatment before extraction of RNA or protein.
Lactate Dehydrogenase Cytotoxicity Assay
A sample of medium was taken 24 hours post-transfection to assess cytotoxicity by release of lactate dehydrogenase (LDH) into the medium, using the LDH Cytotoxicity Detection Kit (Roche, Burgess Hill, UK), following the manufacturer's instructions. The mean of three readings for each sample was recorded, with medium only, untreated and dead controls. The readings were normalised for background (minus medium only) and percentage toxicity expressed as [(sample-untreated)/(dead-untreated)×100].
RNA Isolation and Reverse Transcription Polymerase Chain Reaction Analysis
As with cell culture, two different techniques were used in the two centres involved in this study for isolating RNA and its analysis by RT-PCR, as described previously [4]. PCR products were analysed on 1.5% (w/v) agarose gels in Tris-borate/EDTA buffer. Skipping efficiencies were determined by quantification of the full length and skipped PCR products by densitometry using GeneTools software (Syngene, Cambridge, UK).
Sequence Analysis
RT-PCR products were excised from agarose gels and extracted with a QIAquick gel extraction kit (Qiagen, Crawley, UK). Direct DNA sequencing was carried out by the MRC Genomics Core Facility.
Western Blot Analysis of Dystrophin Protein
DMD patient cells, transfected as described and cultured in differentiation medium, were harvested 7, 14 or 21 days post-transfection. 4×10 5 cells were pelleted and resuspended in 50 μl of loading buffer (75 mM Tris-HCl pH 6.8, 15% sodium dodecyl sulphate, 5% β-mercaptoethanol, 2% glycerol, 0.5% bromophenol blue and complete mini protease inhibitor tablet). Samples were incubated at 95° C. for 5 minutes and centrifuged at 18,000×g for 5 minutes. 20 μl of sample was loaded per well in a 6% polyacrylamide gel with 4% stacking gel. Protein from CHQ5B cells differentiated for 7 days was used as a positive control for dystrophin. Gels were electrophoresed for 5 hours at 100V before blotting on nitrocellulose membrane at 200 mA overnight on ice. Blots were stained with Protogold to assess protein loading, then blocked in 10% non-fat milk in PBS with 2% tween (PBST) for 3 hours. Blots were probed with antibodies to dystrophin, NCL-DYS1 (Vector Labs, Peterborough, UK) diluted 1:40 and to dysferlin, Hamlet1 (Vector Labs) diluted 1:300 in 3% non-fat milk/PBST. An anti-mouse, biotinylated secondary antibody (diluted 1:2000; GE Healthcare, Amersham, UK) and streptavidin/horse radish peroxidise conjugated antibody (1:10,000; Dako, Ely, UK) allowed visualisation in a luminol-HRP chemiluminescence reaction (ECL-Plus; GE Healthcare) on Hyperfilm (GE Healthcare), exposed at intervals from 10 seconds to 4 minutes.
Transgenic Human DMD Mice
A transgenic mouse expressing a complete copy of the human DMD gene has been generated [8, 39]. Experiments were performed at the Leiden University Medical Center, with the authorization of the Animal Experimental Commission (UDEC) of the Medical Faculty of Leiden University as described previously [4].
Results
Twenty-three PMOs were designed to target exon 53, as described previously [38]. Briefly, SR protein binding motifs, RNA secondary structure and accessibility to binding as determined by hexamer hybridization array analysis, were used as aids to design ( FIG. 1 ). Table 4 summarises the names and target sequence characteristics of these PMOs. These PMOs were initially characterized in normal human skeletal muscle cells (at RHUL). The most active were then directly compared to the PMO targeting the sequence previously identified as most bioactive by Wilton et al. [19] in exon 53-skippable patient cells (at UCL), and in the humanised DMD mouse (at LUMC).
Comparison of PMOs to Exon 53 in Normal Human Skeletal Muscle Cells
An array of seventeen 25 mer leashed PMOs were transfected, at a concentration of 500 nM, into normal human skeletal muscle myoblast cultures using lipofectin. Of these seventeen, only four produced consistent levels of exon skipping considered to be above background i.e. over 5% skipping [38], as assessed by densitometric analysis ( FIG. 6 a ). These were PMO-A, -B, -C and -D, which targeted exon 53 at positions +35+59, +38+62, +41+65 and +44+68 respectively. The levels of exon skipping produced were as follows: PMO-A, 12.7%; PMO-B, 9.7%; PMO-C, 10.5%; and PMO-D, 9.0%. When nucleofection was used as a means of introducing naked PMOs into the cells, higher levels of exon skipping were observed for PMO-A and PMO-B only, with 300 nM doses producing 41.2% and 34.3% exon skipping, respectively. The superiority of nucleofection over lipofection has been observed by others (Wells et al., in preparation). However no exon skipping was evident following nucleofection with any of the other naked 25 mer PMOs tested (data not shown).
A 3nt-stepped array of 30 mer PMOs was then designed to target the region of exon 53 (position +30 to +74) associated with exon skipping activity by the 25 mer PMOs. Following lipofection into normal human skeletal muscle myoblast cultures at a concentration of 500 nM, PMO-G (+30+59), PMO-H (+33+62), PMO-I (+36+65), PMO-J (+39+68) and PMO-K (+42+71) gave reproducible exon skipping above background ( FIG. 6 b ), while PMO-L (+45+74) was inactive. The levels of exon skipping produced were as follows: PMO-G, 37.1%; PMO-H, 44.5%; PMO-I, 27.4%; PMO-J, 33.0%; and PMO-K, 13.0%. The concentration dependence of exon skipping by the more active 30 mer PMOs was examined further ( FIG. 7 a ). PMO-H and PMO-I were able to produce convincing skipping at concentrations as low as 25 nM, while PMO-G was active at 50 nM and PMO-J at 75 nM. The exon skipping produced by these 30 mer PMOs was shown to be persistent, surviving the lifetime of the cultures (14 days) ( FIG. 7 b and data not shown). When unleashed 30 mer PMOs were introduced into normal muscle cultures by nucleofection, high levels of exon skipping were also observed. For example, at 300 nM, PMO-G and PMO-H gave over 80% skipping of exon 53 (data not shown).
Comparison of PMOs to Exon 53 in DMD Patient Cells
The PMOs, both 25 mer and 30 mer, that produced the highest levels of DMD exon 53 skipping in normal skeletal muscle cultures, were then compared to each other for bioactivity in DMD patient (del 45-52) cells, and were also compared to an additional reagent, PMO-M (+39+69), described previously [19]. This comparative evaluation was performed in a blinded fashion. When tested and compared directly at 300 nM doses by nucleofection, PMO-G, PMO-H and PMO-A were most active producing in the order of 60% exon skipping ( FIG. 8 ). The other PMOs tested produced the following exon skipping levels: PMO-I, 45%; PMO-B, 41%; PMO-J, 27%; PMO-M, 26%. All the other PMOs tested gave exon skipping at lower levels of between 10 and 20%.
When the concentration dependence of exon skipping was examined for the most bioactive PMOs, levels approaching 30% were evident for PMO-G and PMO-H at concentrations as low as 25 nM ( FIG. 9 a, b ). Similar levels of skipping were only achieved by PMO-A, PMO-B and PMO-M at 100 nM, while PMO-I needed to be present at 200 nM to produce over 30% exon skipping ( FIG. 9 a, b ). There was no evidence that any of the PMOs tested caused cellular cytotoxicity relative to mock-transfected controls, as assessed by lactate dehydrogenase release into culture medium (results not shown). The exon skipping produced by the six most bioactive PMOs was shown to be persistent, lasting for up to 10 days after transfection, with over 60% exon skipping observed for the lifetime of the cultures for PMO-A, PMO-G and PMO-H ( FIG. 10 a, b ). Exon skipping was shown to persist for 21 days for PMO-A and PMO-G ( FIG. 10 c ).
Western blot analysis of DMD patient (del 45-52) cell lysates, treated in culture with the most bioactive 25 mers (PMO-A and PMO-B) and longer PMOs (PMO-G, PMO-H, PMO-I and PMO-M) is shown in FIG. 10 e . De novo expression of dystrophin protein was evident with all six PMOs, but was most pronounced with PMO-H, PMO-I, PMO-G and PMO-A, producing 50%, 45%, 33% and 26% dystrophin expression, respectively, relative to the positive control, and seemingly weakest with PMO-B and PMO-M (11% and 17% dystrophin expression respectively, relative to the positive control). However, the limitations of quantifying Western blots of this nature should be taken into account when interpreting the data.
Comparison of PMOs to Exon 53 in Humanised DMD Mouse
The hDMD mouse is a valuable tool for studying the processing of the human DMD gene in vivo, and as such provides a model for studying the in vivo action of PMOs, prior to clinical testing in patients. PMO-A, PMO-G, PMO-H, PMO-I and PMO-M were injected into the gastrocnemius muscle of hDMD mice, and RNA extracted from the muscles was analysed for exon 53 skipping ( FIG. 11 ). Skipping of exon 53 is evident for each of the PMOs tested; 8% for PMO-A, 7.6% for PMO-I, 7.2% for PMO-G, but to a slightly lower level of 4.8% for PMO-H. PMO-M produced exon skipping levels of less than 1%, which is the detection threshold for the system used.
It should be noted that the levels of exon skipping by each particular PMO was variable. This has been reported previously [8], and is likely to be due to the poor uptake into the non-dystrophic muscle of the hDMD mouse. However this does not compromise the importance of the finding that the PMOs tested here are able to elicit the targeted skipping of exon 53 in vivo.
Of the 24 PMOs tested, six (PMO-A, PMO-B, PMO-G, PMO-H, PMO-I and PMO-M) produced over 50% targeted skipping of exon 53 either in normal myotubes or in patient myotubes or both. The characteristics of these active PMOs and their target sites are summarised in Table 4. They all showed strong overlap (92%-100%) with the sequence shown to be accessible to binding on the hybridization array analysis, had similar GC content (50%-56%), but varying degrees of overlap (32%-60%) with ESE sites as predicted by Rescue ESE analysis, varying degrees of overlap with ESE sites and ESS sites (60%-86% and 0%-10%, respectively) as predicted by PESX analysis, and all showed overlap with two SR binding motifs (SF2/ASF, as defined by the BRCA1 algorithm, and SRp40). It should be noted that PMO-J, -K, -L and -M had a common SNP of exon 53 (c7728C>T) in the last, fourth to last, seventh to last and second to last base, respectively of their target sites. There is the potential that this allelic mismatch could influence the binding and bioactivity of these PMOs. However, the more active PMOs (-A, -B, -G, -H and -I) all had their target sites away from the SNP, and the possible effect of a mismatch weakening binding and bioactivity is removed, and allows definitive comparisons between these PMOs to be made.
Discussion
The putative use of AOs to skip the exons which flank out-of-frame deletions is fast becoming a reality in the experimental intervention of DMD boys. Indeed the restoration of dystrophin expression in the TA muscle of four patients, injected with a 2′OMePS AO optimised to target exon 51 of the DMD gene, has been reported recently [11]. Moreover a clinical trial using a PMO targeting exon 51 has recently been completed in seven DMD boys in the UK (Muntoni et al, in preparation). However, the targeted skipping of exon 51 would have the potential to treat only 13% of DMD patients with genomic deletions on the Leiden database [37]. There is therefore a definite requirement for the optimisation of AOs to target other exons commonly mutated in DMD.
Although there have been many large screens of AO bioactivity in vitro [18, 19, 38, 40], no definite rules to guide AO design have become apparent. Previous studies in the mdx mouse model of DMD showed that AOs that targeted the donor splice site of exon 23 of the mouse DMD gene restored dystrophin expression [7]. However the targeting of AOs to the donor splice sites of exon 51 of the human DMD gene was ineffective at producing skipping [4], and it has been suggested that the ‘skippability’ of human DMD exons has no correlation with the predicted strength of the donor splice site [41]. It has been reported that exon skipping could be induced by the targeting of AOs to exonic splicing enhancer (ESE) motifs [18, 40]. These motifs are recognised by SR proteins, which facilitate exon splicing by recruiting splicing effectors (U1 and U2AF) to the donor splice site (reviewed by Cartegni et al.) [42]. However these motifs are divergent, poorly defined, their identification complex, and their strength as AO design tools dubious [38].
A comparative study of 66 PMOs designed to five different DMD exons demonstrated the significance of RNA secondary structure in relation to accessibility of the PMO target site and subsequent PMO bioactivity [38], as assessed by mfold software prediction of secondary structure [25], and a hybridization screen against a hexamer array [38]. PMOs that bound to their target more strongly, either as a result of being longer or in being able to access their target site more directly, were significantly more bioactive. The influence of AO length on bioactivity has been reported elsewhere [4, 30], and is further confirmed in the present study; all 30 mers tested were more bioactive relative to their 25 mer counterpart. The fact that 30 mer PMOs were more bioactive than 25 mer PMOs targeted to the same open/accessible sites on the exon, would suggest that strength of binding of PMO to the target site may be the most important factor in determining PMO bioactivity. These thermodynamic considerations have also been reported in a complementary study of 2′OMePS AOs [40]. However, it has also been reported that two overlapping 30 mers were not as efficient as a 25 mer at skipping mouse exon 23, indicating that oligomer length may only be important in some cases [4].
To ensure that the analysis of PMOs for the targeted skipping of exon 53 was not biased by any particular design strategy, seventeen 25 mer PMOs were designed to cover the whole of exon 53, with stepwise arrays over suggested bioactive target sites, and then subsequently six 30 mer PMOs were designed to target the sequence of exon 53 that showed an association with exon skipping for the 25 mers tested. PMOs were designed and tested independently by two different groups (at RHUL and UWA), and then efficacy of the best thirteen sequences confirmed by two other independent groups (at UCL and LUMC). Such a collaborative approach has been used previously as a way of validating target sequences in DMD [4]. Human myoblasts allowed the controlled in vitro comparison of PMO sequences, and confirmation of skipping of exon 53 at the RNA level by certain PMOs in both normal cells and, perhaps more importantly, in DMD patient cells with a relevant mutation. These results were further borne out by the expression of dystrophin protein in the DMD cells treated with specific PMOs. Use of the humanised DMD mouse provided an in vivo setting to confirm correct exon exclusion prior to any planned clinical trial. The combined use of these three different systems (normal cells, patient cells and hDMD mouse) as tests of PMO bioactivity provided a reliable and coherent determination of optimal sequence(s) for the targeted skipping of exon 53.
When considering the data presented here as a whole, the superiority of the PMO targeting the sequence +30+59 (PMO-G, or h53A30/1), is strongly indicated. In normal myoblasts, nucleofection of PMO-G (300 nM) and liposomal-carrier mediated transfection of leashed PMO-G (500 nM) produced over 80% and over 50% skipping of exon 53, respectively, implying that it acts extremely efficiently within the cell. This was confirmed in patient cells. Indeed, this PMO generates the highest levels of exon skipping in patient cells over a range of concentrations (up to 200 nM) and, most important therapeutically, exerts its activity at concentrations as low as 25 nM. The exon skipping activity of this PMO is also persistent, with over 70% exon skipping for 7 days in culture, and over 60% exon skipping for up to three weeks. This would have important safety and cost implications as a genetic therapy for DMD patients with the appropriate deletions. PMO-G was also shown to skip exon 53 correctly in vivo. These RNA results were further confirmed by the detection of dystrophin protein at a high level in protein extracts from patient cells treated with PMO-G. Previous studies by the Leiden group [18] suggest that the optimal 2′OMePS AO is targeted to the sequence +46+63 of exon 53, producing exon skipping in up to 25% of transcripts in cultured cells and 7% in the hDMD mouse. This 2′OMePS AO shows some degree of overlap with the optimal PMOs reported here which strengthens our findings. The reason that our optimal PMO is more specific could be a (combined) consequence of the different AO chemistries, length of AO used, and the absolute target site of AO.
The sequence h53A30/1 we have identified appears to be more efficient than any of the previously reported AOs designed to skip exon 53 of the DMD gene, and this PMO therefore represents, at the present time, the optimal sequence for clinical trials in DMD boys.
Table 4: Table Summarizing the Characteristics of PMOs Used
Characteristics of the PMOs and their target sites listed.
b calculated as % of PMO target site in open structures on predicted RNA secondary structure obtained using MFOLD analysis. The position of the PMO target sites relative to open loops in the RNA secondary structure is listed (0=no ends in open loops, 1=one end in an open loop, 2=both ends in open loops).
c In the analyses, SR binding sites were predicted using splice sequence finder (http://www.umd.be/SSF/) software. Values above threshold are given for PMOs whose target sites cover 50% or more of potential binding sites for SF2/ASF, BRCA1, SC35, SRp40, SRp55, Tra2β and 9G8
TABLE 4
%
%
Exon-
PMO-
Ends
overlap
#
overlap
PMO
PMO
in
with
Rescue
with
Position
binding
binding
%
open
hybrid.
ESE
Rescue
PMO
Start
End
% GC
energy
energy
open b
loops b
peak
sites
ESE
A
h53A1
+35
+59
52
−38.6
−17.4
50
2
92
7
56
B
h53A2
+38
+62
56
−36.1
−17.4
46.7
1
100
4
32
C
h53A3
+41
+65
56
−36.7
−13.7
36.7
0
0
3
32
D
h53A4
+44
+68
48
−34.3
−8.5
20
0
100
4
28
E
h53A5
+47
+71
48
−35.5
−8.5
43.3
2
100
3
36
F
h53A6
+50
+74
48
−35.3
−8.5
43.3
2
92
2
36
N
h53B1
+69
+93
28
−22.1
−12.1
53.3
1
0
5
56
O
h53B2
+80
+104
48
−30.1
−11.3
23.3
1
0
5
60
P
h53B3
+90
+114
48
−34.5
−5.5
48
2
0
8
72
Q
h53C1
+109
+133
48
−32.4
−9.8
46.7
2
0
6
52
R
h53C2
+116
+140
56
−31.3
−12.7
33.3
1
0
1
24
S
h53C3
+128
+152
60
−34.6
−13.7
26.7
1
0
1
24
T
h53D1
+149
+173
52
−34.1
−13.4
30
1
0
4
40
U
h53D2
+158
+182
48
−36.5
−14.5
40
2
0
6
44
V
h53D3
+170
+194
36
−34.3
−11.2
40
1
0
9
64
W
h53D4
+182
+206
32
−30.9
−9.2
63.3
1
0
16
96
X
h53D5
+188
+212
36
−31.5
−3.3
66.7
1
0
14
92
G
h53A30/1
+30
+59
50
−48.1
−17.4
56.7
1
92
9
60
H
h53A30/2
+33
+62
53
−45.1
−17.4
63.3
1
100
8
53
I
h53A30/3
+36
+65
53
−44.6
−17.4
53.3
1
100
6
43
J
h53A30/4
+39
+68
50
−43.4
−17.4
43.3
1
100
4
43
K
h53A30/5
+42
+71
47
−42.4
−11.3
46.7
1
100
5
47
L
h53A30/6
+45
+74
47
−42.3
−8.5
56.7
1
100
5
48
M
H53A
+39
+69
52
−48.5
−17.4
48.4
2
100
4
45
% overlap
with
ESE finder values over threshold c
PMO
PESE
PESS
SF2/ASF
BRCA1
SC35
SRp40
SRp55
Tra2B
9G8
A
h53A1
84
0
6.58
7.26
0
3.12
0
24.04
19.02
B
h53A2
72
0
6.58
7.26
0
3.12
0
7.25
19.02
C
h53A3
60
0
6.58
7.26
0
3.12
0
7.25
11.9
D
h53A4
48
8
6.58
7.26
0
3.12
0
7.25
11.9
E
h53A5
36
20
6.58
7.26
0
3.12
0
7.25
11.9
F
h53A6
28
32
6.58
7.26
0
0
0
7.25
11.9
N
h53B1
40
40
0
9.26
3.62
10.66
0
5.06
1.1
O
h53B2
60
0
0
9.26
3.62
4.73
0
5.06
8.28
P
h53B3
64
0
3.49
9.26
3.44
4.73
0
24.04
28.68
Q
h53C1
72
0
4.19
6.72
0
2.04
0
24.04
28.68
R
h53C2
60
0
4.19
6.72
10.2
4.38
0
0
8.28
S
h53C3
32
0
3.49
6.41
10.2
4.38
6.86
0
14.18
T
h53D1
32
0
0.52
0
18.68
0
6.86
0
12.71
U
h53D2
32
0
0.52
1.8
18.68
0.42
0
0
12.71
V
h53D3
0
0
0
1.8
0
6.95
0
24.04
10.49
W
h53D4
24
0
8.5
11.95
0
7.67
0.33
24.04
7.14
X
h53D5
44
0
8.5
11.95
0
7.67
0.33
24.04
7.14
G
h53A30/1
86
0
6.58
7.26
0
3.12
0
24.04
19.02
H
h53A30/2
77
0
6.58
7.26
0
3.12
0
24.04
19.02
I
h53A30/3
67
0
6.58
7.26
0
3.12
0
24.04
19.02
J
h53A30/4
57
7
6.58
7.26
0
3.12
0
7.25
11.9
K
h53A30/5
47
17
6.58
7.26
0
3.12
0
7.25
11.9
L
h53A30/6
37
27
6.58
7.26
0
3.12
0
7.25
11.9
M
H53A
58
10
6.58
7.26
0
3.12
0
7.25
11.9
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12. Gebski B L, Mann C J, Fletcher S, Wilton S D (2003). Morpholino antisense oligonucleotide induced dystrophin exon 23 skipping in mdx mouse muscle. Hum Mol Genet; 12: 1801-1811.
13. Alter J, Lou F, Rabinowitz A, Yin H, Rosenfeld J, Wilton S D, et al. (2006). Systemic delivery of morpholino oligonucleotide restores dystrophin expression bodywide and improves dystrophic pathology. Nat Med; 12: 175-177.
14. Fletcher S, Honeyman K, Fall A M, Harding P L, Johnsen R D, Wilton S D (2006). Dystrophin expression in the mdx mouse after localized and systemic administration of a morpholino antisense oligonucleotide. J Gene Med; 8: 207-216.
15. McClorey G, Fall A M, Moulton H M, Iversen P L, Rasko J E, Ryan M, et al. (2006). Induced dystrophin exon skipping in human muscle explants. Neuromus Disorders; 16: 583-590.
16. McClorey G, Moulton H M, IversenPL, Fletcher S, Wilton S D (2006). Antisense oligonucleotide-induced exon skipping restores dystrophin expression in vitro in a canine model of DMD. Gene Ther; 13:1373-1381.
17. Arora V, Devi G R, Iversen P L (2004). Neutrally charged phosphorodiamidate morpholino antisense oligomers: uptake, efficacy and pharmacokinetics. Curr Pharm Biotechnol; 5: 431-439.
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19. Wilton S D, Fall A M, Harding P L, McClorey G, Coleman C, Fletcher S (2007). Antisense oligonucleotide-induced exon skipping acroos the human dystrophin gene transcript. Mol Ther; 15: 1288-1296.
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21. Smith P J, Zhang C, Wang J, Chew S L, Zhang M O, Krainer A R (2006). An increased specificity score matrix for the prediction of SF2/ASF-specific exonic splicing enhancers. Human Mol Genet; 15: 2490-2508.
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23. Zhang X H, Leslie C S, Chasin L A (2005). Computational searches for splicing signals. Methods; 37: 292-305.
24. Fairbrother W G, Yeh R F, Sharp P A, Burge C B (2002). Predictive identification of exonic splicing enhancers in human genes. Science; 297: 1007-1013.
25. Mathews D H, Sabina J, Zuker M, Turner D H (1999). Expanded sequence dependence of thermodynamic parameters improves prediction of RNA secondary structure. J Mol Biol; 288: 911-940.
26. Aartsma-Rus A, Bremmer-Bout M, Janson A A M, den Dunnen J T, van Ommen G-J B, van Deutekom J C T (2002). Targeted exon skipping as a potential gene correction therapy for Duchenne muscular dystrophy. Neuromus Disorders; 12: 871-877.
27. Aartsma-Rus A, Kaman W E, Weij R, den Dunnen J T, van Ommen G J, van Deutekom J C. (2006). Exploring the frontiers of therapeutic exon skipping for Duchenne muscular dystrophy by double targeting within one or multiple exons. Mol Ther; 14: 401-407.
28. Adams A M, Harding P L, Iversen P L, Coleman C, Fletcher S, Wilton S D. (2007). Antisense oligonucleotide induced exon skipping and the dystrophin gene transcript: cocktails and chemistries. BMC Mol Biol; 8: 57.
29. Vickers T A, Wyatt J R, Freier S M (2000). Effects of RNA secondary structure on cellular antisense activity. Nucleic Acids Res; 28: 1340-1347.
30. Harding P L, Fall A M, Honeyman K, Fletcher S, Wilton S D (2007). The influence of antisense oligonucleotide length on dystrophin exon skipping. Mol Ther; 15: 157-166.
31. Wee K B, Pramono Z A D, Wang J L, MacDorman K F, Lai P S, Yee W C (2008). Dynamics of co-translational pre-mRNA folding influences the induction of dystrophin exon skipping by antisense oligonucleotides. Plos one; 3: e1844.
32. Fairbrother W G, Yeo G W, Yeh R, Goldstein P, Mawson M, Sharp P A, et al. (2004). RESCUE-ESE identifies candidate exonic splicing enhancers in vertebrate exons. Nucleic Acids Res; 32: W187-190.
33. Patzel V, Steidl R, Kronenwell R, Haas R, Sczakiel G (1999). A theoretical approach to select effective antisense oligodeoxyribonucleotides at high statistical probability. Nucleic Acids Res; 27: 4328-4334.
34. Ihaka R, Gentleman R C (1996). R: A Language for Data Analysis and Graphics. Journal of Computational and Graphical Statistics; 15: 999-1013.
35. Moulton H M, Fletcher S, Neuman B W, McClorey G, Stein D A, Abes S, Wilton S D, Buchmeier M J, Lebleu B, Iversen P L (2007). Cell-penetrating peptide-morpholino conjugates alter pre-mRNA splicing of DMD (Duchenne muscular dystrophy) and inhibit murine coronavirus replication in vivo. Biochem. Soc. Trans. 35: 826-8.
36. Jearawiriyapaisarn N, Moulton H M, Buckley B, Roberts J, Sazani P, Fucharoen S, Iversen P L, Kole R (2008). Sustained Dystrophin Expression Induced by Peptide-conjugated Morpholino Oligomers in the Muscles of mdx Mice. Mol. Ther . June 10. Epub ahead of print.
37. Aartsma-Rus A, Fokkema I, Verschuuren J, Ginjaar I, van Deutekom J, van Ommen G J et al. Theoretic applicability of antisense-mediated exon skipping for Duchenne muscular dystrophy mutations. Hum Mutation 2009; January 20 (Epub).
38. Popplewell L J, Trollet C, Dickson G, Graham I R. Design of phosphorodiamidate morpholino oligomers (PMOs) for the induction of exon skipping of the human DMD gene. Mol Ther 2009; January 13 (Epub).
39. 'tHoen PAC, de Meijer E J, Boer J M, Vossen R H, Turk R, Maatman R G et al. (2008) Generation and characterization of transgenic mice with the full-length human DMD gene. J Biol Chem; 283: 5899-5907.
40. Aartsma-Rus A, van Vliet L, Hirschi M, Janson A A, Heemskerk H, de Winter C L, et al. Guidelines for antisense oligonucleotide design and insight into splice-modulating mechanisms. Mol Ther 2008; September 23 (Epub).
41. Aartsma-Rus A, van Ommen G J. Antisense-mediated exon skipping: A versatile tool with therapeutic and research applications. RNA 2007; 13: 1-16.
42. Cartegni L, Chew S L, Krainer A R. Listening to silence and understanding nonsense: Exonic mutations that affect splicing. Nat Rev Genet. 2002; 3: 285-298. | Molecules are provided for inducing or facilitating exon skipping in forming spliced mRNA products from pre-mRNA molecules in cells. The molecules may be provided directly as oligonucleotides or expression products of vectors that are administered to a subject. High rates of skipping can be achieved. High rates of skipping reduce the severity of a disease like Duchene Muscular Dystrophy so that the disease is more like Becker Muscular Dystrophy. This is a severe reduction in symptom severity and mortality. | 2 |
This is a continuation of copending application Ser. No. 07/669,792 filed on Mar. 15, 1991 now abandoned.
FIELD OF THE INVENTION
The present invention relates to the pulmonary administration of a therapeutic protein and, more particularly, to the systemic administration of therapeutically effective amounts of granulocyte colony stimulating factor (G-CSF) via the respiratory system.
BACKGROUND OF THE INVENTION
G-CSF is a hormone-like glycoprotein which regulates hematopoiesis and is required for the clonal growth and maturation of normal hematopoietic precursor cells found in the bone marrow; Welte et al., Proc. Natl. Acad. Sci., Vol. 82, pp. 1526-1530 (1985). More specifically, G-CSF, when present in low concentrations, is known to stimulate the production of neutrophil granulocytic colonies when used in vitro G-CSF is also known to enhance neutrophil migration; Gabrilove, J., Seminars in Hematology, Vol. 26, No. 2, pp. 1-4 (1989). Moreover, G-CSF can significantly increase the ability of neutrophils to kill tumor cells in vitro through antibody mediated cellular cytotoxicity; Souza et al., Science, Vol. 232, pp. 61-65 (1986).
In humans, endogenous G-CSF is detectable in blood plasma; Jones et al., Bailliere's Clinical Hematology, Vol. 2, No. 1, pp.83-111. G-CSF is produced by fibroblasts, macrophages, T cells, trophoblasts, endothelial cells and epithelial cells and is the expression product of a single copy gene comprised of four exons and five introns located on chromosome seventeen. Transcription of this locus produces a mRNA species which is differentially processed, resulting in the expression of two forms of G-CSF, one version having a mature length of 177 amino acids, the other having a mature length of 174 amino acids. The form comprised of 174 amino acids has been found to have the greatest specific in vivo biological activity. G-CSF is species cross-reactive, such that when human G-CSF is administered to another mammal such as a mouse, canine or monkey, sustained neutrophil leukocytosis is elicited; Moore et al., Proc. Natl. Acad. Sci., Vol. 84, pp. 7134-7138 (1987).
Human G-CSF can be obtained and purified from a number of sources. Natural human G-CSF (nhG-CSF) can be isolated from the supernatants of cultured human tumor cell lines. The development of recombinant DNA technology, see, for instance, U.S. Pat. No. 4,810,643 (Souza), incorporated herein by reference, has enabled the production of commercial scale quantities of G-CSF in glycosylated form as a product of eukaryotic host cell expression, and of G-CSF in non-glycosylated form as a product of prokaryotic host cell expression.
G-CSF has been found to be useful in the treatment of cancer, as a means of stimulating neutrophil production to compensate for hematopoietic deficits resulting from chemotherapy or radiation therapy. The effective use of G-CSF as a therapeutic agent requires that patients be administered systemic doses of the protein. Currently, parenteral administration via intravenous, intramuscular or subcutaneous injection is the preferred route of administration to humans and has heretofore appeared to be the only practical way to deliver therapeutically significant amounts of G-CSF to the bloodstream, although attempts have been made at oral delivery; see, for example, Takada et al., Chem. Pharm. Bull., Vol. 37, No. 3, pp. 838-839 (1989).
The pulmonary delivery of relatively large molecules is not unknown, although there are only a few examples which have been quantitatively substantiated. Leuprolide acetate is a nonapeptide with luteinizing hormone releasing hormone (LHRH) agonist activity having low oral availability. Studies with animals indicate that inhalation of an aerosol formulation of leuprolide acetate results in meaningful levels in the blood; Adjei et al., Pharmaceutical Research, Vol. 7, No. 6, pp. 565-569 (1990); Adjei et al., InternationaI Journal of Pharmaceutics, Vol. 63, pp. 135-144 (1990).
Endothelin-1 (ET-1), a 21 amino acid vasoconstrictor peptide produced by endothelial cells, has been found to decrease arterial blood pressure when administered by aerosol to guinea pigs; Braquet et al., Journal of Cardiovascular Pharmacology, Vol. 13, suppl. 5, s. 143-146 (1989).
The feasibility of delivering human plasma α1-antitrypsin to the pulmonary system using aerosol administration, with some of the drug gaining access to the systemic circulation, is reported by Hubbard et al., Annals of Internal Medicine, Vol. III, No. 3, pp. 206-212(1989).
Pulmonary administration of alpha-1-proteinase inhibitor to dogs and sheep has been found to result in passage of some of that substance into the bloodstream; Smith et al., J. Clin. Invest., Vol. 84, pp. 1145-1146 (1989).
Experiments with test animals have shown that recombinant human growth hormone, when delivered by aerosol, is rapidly absorbed from the lung and produces faster growth comparable to that seen with subcutaneous injection; Oswein et al., "Aerosolization of Proteins", Proceedings of Symposium on Respiratory Drug Delivery II, Keystone, Colo., March, 1990. Recombinant versions of the cytokines gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) have also been observed in the bloodstream after aerosol administration to the lung; Debs et al., The Journal of Immunology, Vol. 140, pp. 3482-3488 (1988).
SUMMARY OF THE INVENTION
The present invention is based on the discovery that G-CSF can be administered systemically to a mammal via the pulmonary route. Typically, this is accomplished by directing a stream of a therapeutically effective amount of G-CSF into the oral cavity of the inhaling mammal. Importantly, and surprisingly, substantial amounts of G-CSF are thereby deposited in the lung and absorbed from the lung into the bloodstream, resulting in elevated blood neutrophil levels. Moreover, this is accomplished without the necessity to resort to special measures such as the use of absorption enhancing agents or protein derivatives specifically designed to improve absorption. Pulmonary administration of G-CSF thus provides an effective non-invasive alternative to the systemic delivery of G-CSF by injection.
This invention can be practiced using any purified isolated polypeptide having part or all of the primary structural conformation (i.e., continuous sequence of amino acid residues) and one or more of the biological properties of naturally occurring G-CSF. A number of publications describe methods of producing G-CSFs, including the above mentioned Souza patent and the Welte et al. and Nicola et al. articles.
In general, G-CSF useful in the practice of this invention may be a native form isolated pure from mammalian organisms or, alternatively, a product of chemical synthetic procedures or of procaryotic or eucaryotic host expression of exogenous DNA sequences obtained by genomic or cDNA cloning or by gene synthesis. Suitable procaryotic hosts include various bacterial (e.g., E. coli) cells. Suitable eucaryotic hosts include yeast (e.g., S. cerevisiae) and mammalian (e.g., Chinese hamster ovary, monkey) cells. Depending upon the host employed, the G-CSF expression product may be glycosylated with mammalian or other eucaryotic carbohydrates, or it may be non-glycocylated. The G-CSF expression product may also include an initial methionine amino acid residue (at position -1). The present invention contemplates the use of any and all such forms of G-CSF, although recombinant G-CSF, especially E. coli derived, is preferred for reasons of greatest commercial practicality.
Contemplated for use in the practice of this invention are a wide range of mechanical devices designed for pulmonary delivery of therapeutic products, including but not limited to nebulizers, metered dose inhalers, and powder inhalers, all of which are familiar to those skilled in the art.
Some specific examples of commercially available devices suitable for the practice of this invention are the Ultravent nebulizer, manufactured by Mallinckrodt, Inc., St. Louis, Mo.; the Acorn II nebulizer, manufactured by Marquest Medical Products, Englewood, Colo.; the Ventolin metered dose inhaler, manufactured by Glaxo Inc., Research Triangle Park, N.C.; and the Spinhaler powder inhaler, manufactured by Fisons Corp., Bedford, Mass.
All such devices require the use of formulations suitable for the dispensing of G-CSF. Typically, each formulation is specific to the type of device employed and may involve the use of an appropriate propellant material, in addition to the usual diluents, adjuvants and/or carriers useful in G-CSF therapy. G-CSF formulations which can be utilized in the most common types of pulmonary dispensing devices to practice this invention are now described.
Nebulizer G-CSF Formulation
G-CSF formulations suitable for use with a nebulizer, either jet or ultrasonic, will typically comprise G-CSF dissolved in water at a concentration of about 0.1 to 25 mg of G-CSF per mL of solution. The formulation may also include a buffer and a simple sugar (e.g., for protein stabilization and regulation of osmotic pressure). Examples of buffers which may be used are sodium acetate, citrate and glycine. Preferably, the buffer will have a composition and molarity suitable to adjust the solution to a pH in the range of 3 to 4. Generally, buffer molarities of from 2 mM to 50 mM are suitable for this purpose. Examples of sugars which can be utilized are mannitol and sorbitol, usually in amounts ranging from 1% to 10% by weight of the formulation.
The nebulizer formulation may also contain a surfactant, to reduce or prevent surface induced aggregation of the protein caused by atomization of the solution in forming the aerosol. Various conventional surfactants can be employed, such as polyoxyethylene fatty acid esters and alcohols, and polyoxyethylene sorbitan fatty acid esters. Amounts will generally range between 0.001 and 4% by weight of the formulation. An especially preferred surfactant for purposes of this invention is polyoxyethylene sorbitan monooleate.
Metered Dose Inhaler G-CSF Formulation
G-CSF formulations for use with a metered-dose inhaler device will generally comprise a finely divided powder containing G-CSF suspended in a propellant with the aid of a surfactant. The propellant may be any conventional material employed for this purpose, such as a chlorofluorocarbon, a hydrochlorofluorocarbon, a hydrofluorocarbon, or a hydrocarbon, including trichlorofluoromethane, dichlorodifluoromethane, dichlorotetrafluoroethanol, and 1,1,1,2-tetrafluoroethane, or combinations thereof. Suitable surfactants include sorbitan trioleate and soya lecithin. Oleic acid may also be useful as a surfactant.
Powder Inhaler G-CSF Formulation
G-CSF formulations for dispensing from a powder inhaler device will comprise a finely divided dry powder containing G-CSF and may also include a bulking agent, such as lactose, sorbitol, sucrose, or mannitol in amounts which facilitate dispersal of the powder from the device, e.g., 50 to 90% by weight of the formulation. The G-CSF should most advantageously be prepared in particulate form with an average particle size of less than 10 μm (or microns), most preferably 1 to 5 μm, for most effective delivery to the distal lung.
The invention contemplates the administration of therapeutic amounts of the protein, i.e., sufficient to achieve elevation of the neutrophil level in the systemic blood. What constitutes a therapeutically effective amount in a particular case will depend on a variety of factors which the knowledgeable practitioner will take into account, including the normal blood neutrophil level for that subject, the severity of the condition or illness being treated, the degree of neutropenia, the physical condition of the subject, and so forth. In general, a dosage regimen will be followed such that the normal blood neutrophil level for the individual undergoing treatment is restored, at least in cases of abnormally low or depressed blood neutrophil counts. For humans, the normal blood neutrophil level is about 5000 to 6000 neutrophils per microliter of blood. Neutrophil counts below 1000 in humans are generally regarded as indicative of severe neutropenia and as placing the subject at great risk to infection. Clinical studies with cancer patients suffering from chemotherapy-induced neutropenia have shown that subcutaneous injected doses of 3-5 μg/kg every twenty-four hours are effective in elevating acutely deficient blood neutrophil levels above 1000. Based on preliminary results with animals, described below, it is anticipated that for most mammals, including humans, the administered dose for pulmonary delivery (referred to here as the inhalation dose) will be about 3 to 10 times the corresponding subcutaneous dose necessary to achieve a particular blood neutrophil level.
As those skilled in the art will recognize, the operating conditions for delivery of a suitable inhalation dose will vary according to the type of mechanical device employed. For some aerosol delivery systems, such as nebulizers, the frequency of administration and operating period will be dictated chiefly by the amount of G-CSF per unit volume in the aerosol. In general, higher concentrations of protein in the nebulizer solution and, correspondingly, the aerosol will require shorter operating periods. Some devices such as metered dose inhalers may produce higher aerosol concentrations than others and thus will be operated for shorter periods to give the desired result.
Other devices such as powder inhalers are designed to be used until a given charge of active material is exhausted from the device. The charge loaded into the device will be formulated accordingly to contain the proper inhalation dose amount of G-CSF for delivery in a single administration.
While G-CSF has been found useful in treating neutrophil-deficient conditions such as chemotherapy related neutropenia, G-CSF is expected to also be effective in combatting infections and in treating other conditions or illnesses where blood neutrophil levels elevated above the norm can result in medical benefit. As further studies are conducted, information will emerge regarding appropriate dosage levels for the administration of G-CSF in these latter cases. It is expected that the present invention will be applicable as a non-invasive alternative in most instances where G-CSF is administered therapeutically by injection.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical depiction of the effect of subcutaneously administered rhG-CSF on blood neutrophil levels in hamsters.
FIG. 2 is a bar graph of the blood neutrophil levels in hamsters following exposure to aerosols generated from either an Acorn II nebulizer or an Ultravent nebulizer, using different concentrations of rhG-CSF in aqueous solution.
FIG. 3 depicts a comparison of blood neutrophil levels resulting from subcutaneous and aerosol administration of rhG-CSF.
DETAILED DESCRIPTION
As mentioned, parenteral administration of G-CSF is known to cause an increase in the number of neutrophils in the peripheral blood. Studies were performed to demonstrate that inhalation of an aerosol of recombinant human G-CSF (rhG-CSF) also causes an increase in the number of blood neutrophils. The rhG-CSF employed was an E. coli derived recombinant expression product having the amino acid sequence shown in FIG. 7 of the aforementioned Souza patent comprising the entire hG-CSF polypeptide with an amino terminal methionine group. It can be made by use of the same procedure described therein.
Subcutaneous Administration to Hamsters
Initial experiments were performed to measure the change in the number of neutrophils in the blood of 4-6 week old male Golden Syrian hamsters (Charles River Laboratories, Wilmington, Mass.), following subcutaneous administration of various doses of rhG-CSF. The rhG-CSF was prepared as a 4 mg/ml solution in sterile distilled water, diluted in sterile 0.9% saline solution, and different volumes were immediately injected subcutaneously in the lower back of hamsters in test groups of 3 to 5 animals. Twenty-four hours later, blood was collected from each hamster by cardiac puncture under halothane anesthesia. The number of neutrophils in the blood was determined by performing differential and complete blood cell counts. Results of these experiments, shown in FIG. 1, indicate a dose-dependent increase in the number of neutrophils twenty-four hours after injection of rhG-CSF is observed for doses up to approximately 100 micrograms per kilogram of body weight (μg/kg). The dose response curve appeared to level off at greater doses.
Aerosol Characterization and Administration
Inhalation exposures to aerosols containing rhG-CSF were conducted using a small animal exposure chamber manufactured by In-Tox Products (Albuquerque, N. Mex.). Only the central 12 ports in the animal chamber were used; the peripheral ports in the aerosol distribution manifold in the animal chamber were sealed. With this modification to the chamber, the air supplied by a nebulizer was adequate to maintain 10 hamsters during an exposure. Filter samples were taken from one of the animal ports and from the air exhaust line to measure the aerosol concentration in the exposure chamber. The aerosol was sampled from the remaining available animal port, and particle size distribution measurements with a QCM (quartz crystal monitor) cascade impactor (California Instruments, Inc., Sierra Madre, Calif.) were taken periodically throughout an exposure. This cascade impactor draws only 240 mL/min, which allows the particle size distribution of the aerosol to be measured without disturbing the airflow pattern in the exposure chamber.
Prior to conducting the animal exposure studies, the aerosol concentration and particle size distribution of aerosols generated from a 20 mg/mL albumin solution, using either the Ultravent nebulizer or the Acorn II nebulizer (both jet type), were measured in the exposure chamber. Table 1 shows the particle size distribution and the average albumin concentration in the aerosol measured at two locations(nose and outlet) in the chamber. The Ultravent produced an aerosol having much smaller particles than the Acorn II, but the Acorn II produced a more concentrated aerosol. It was found that the two nebulizers delivered a roughly equivalent amount of protein to an animal when the devices were operated until the initial charge of 5 mL was exhausted and aerosol generation became erratic (10 or 15 minutes for the Acorn II depending on the operating air flow rate, and 20 minutes for the Ultravent).
TABLE 1______________________________________AEROSOL CONCENTRATION AND INHALATIONDOSE ESTIMATES FOR TWO JET NEBULIZERSUSING A 20 mg/ml ALBUMIN SOLUTION Aerosol Delivered Conc. DoseNebulizer (μg/L ± MMAD (μm)* Period (μg ±(airflow) SEM) GSD (min.) SEM)______________________________________Ultravent outlet 0.93 20 76 ± 8 126 ± 13(10 L/min) nose 3.6 20 85 ± 10 141 ± 17Acorn II outlet 2.8 15 107 ± 29 239 ± 48(8 L/min) nose 2.9 15 133 ± 3 297 ± 2(10 L/min) outlet -- 10 109 362______________________________________ *MMAD = Mass median aerodynamic diameter; GSD = Geometric standard deviation; SEM = Standard error of the mean of three determinations.
An estimate of the amount of G-CSF delivered via aerosol to a hamster during an inhalation exposure from a nebulizer was determined from the following expression:
D=ηVCΔt
where D is the inhalation dose, η is the fractional deposition, V is the ventilation rate, C is the aerosol concentration, and Δt is the period of administration. By using the measured aerosol concentration (C) and operating period (Δt) of the nebulizer, along with the resting ventilation rate (V) for a mature hamster of 30 mL/min and a fractional deposition (η) of 0.5, it was determined that G-CSF concentrations of between 5 mg/mL and 10 mg/mL of nebulizer solution would result in an inhalation dose of 100 μg/kg (e.g., 10 μg for a 100 g hamster). This was the dose estimated to produce a maximal neutrophil response via pulmonary delivery.
Aerosol Administration of G-CSF to Hamsters
The solutions used to conduct aerosol exposures were prepared by reconstituting lyophilized rhG-CSF in sterile distilled water containing 1 mg/mL of the nonionic surfactant polyoxyethylenesorbitan monooleate. The solutions used in the nebulizer to generate the exposure aerosols were prepared with G-CSF in concentrations ranging from 1 to 15 mg/mL.
Groups of ten hamsters (mature, male Golden Syrian) were exposed to aerosols containing rhG-CSF. The hamsters were placed in restraining tubes and allowed to acclimate for approximately 5 minutes. The tubes were then inserted into the exposure chamber and the aerosol exposure was initiated. Following exposure, the hamsters were returned to their cages and given free access to food and water. Blood samples were taken 24 hours after exposure, and the blood neutrophil concentration was determined by the same procedure used to evaluate the blood samples following subcutaneous injection.
The aerosol concentration and particle size distribution were measured during each exposure. The G-CSF dose was varied from one exposure to another by using different concentrations of G-CSF in the nebulizer solution.
Hamsters exposed to aerosols containing G-CSF were found to have elevated neutrophil concentrations when compared to untreated animals and animals exposed to an aerosol containing only water and surfactant (polyoxyethylene sorbitum monooleate). FIG. 2 shows the increase in neutrophil counts observed in animals exposed to aerosols generated from rhG-CSF nebulizer solutions ranging in concentration as described. As can be seen, the circulating neutrophil levels obtained from G-CSF aerosol exposure, even with as low a concentration as 1 mg/mL of G-CSF (using the Ultravent nebulizer), were significantly higher (p<0.05) than the group exposed to an aerosol without G-CSF. The statistical significance of the increase in neutrophil levels over the control was p<0.001 for all the other groups. The increase in blood neutrophil levels correlated with increasing G-CSF concentration in the nebulizer solution up to a concentration of 5 mg/mL. A maximum response of 15,000 neutrophils per μL of blood was observed with the more concentrated G-CSF nebulizer solutions, similar to the maximum obtained with subcutaneous injection of doses greater than 50 μg/kg. There was virtually no difference in neutrophil response obtained with the two nebulizers using lower G-CSF solution concentrations, e.g., below 5 mg/mL. For G-CSF solution concentrations greater than 5 mg/mL, the Acorn II nebulizer produced a greater increase in neutrophil response than the Ultravent.
An inhalation exposure to an aerosol generated from a 5 mg/mL G-CSF solution that did not contain surfactant produced a neutrophil response (9,910±960 neutrophils/μL) in hamsters not significantly different from that obtained with either a 50 μg/kg subcutaneous injection containing surfactant (10,935±1,390 neutophils/μL) or a 50 μg/kg subcutaneous injection prepared from the solution lacking surfactant (10,270±430 neutrophils/μL). These values are reported as the mean and standard error of ten animals for the aerosol tests and five animals for the injections. From this experiment, it was concluded that the surfactant was not a necessary component of the aqueous aerosol formulation for G-CSF.
Fractional Deposition of G-CSF Aerosol in Hamster Lungs
The dose delivered to the animal during an exposure was estimated in order to ascertain whether therapeutic amounts of G-CSF can be effectively and economically delivered via the lung. The delivered or deposited dose is the product of the amount of drug the animal inhales and the efficiency (fractional deposition) with which the aerosol particles deposit in the lung. The latter was determined by measurement of the amount of G-CSF recovered from the hamster lungs following aerosol exposure.
G-CSF deposited in the lungs was measured in two groups of four animals exposed to aerosols generated with the Acorn II nebulizer. Immediately following aerosol exposure, the whole lungs of four hamsters were removed, placed into glass tissue grinders containing 3 mL of cold physiological buffered saline, and homogenized. The homogenate was centrifuged twice, and the final supernatent was transferred to a clean tube and assayed for G-CSF using radioimmunoassay (Amgen Inc., Thousand Oaks, Calif.). In control experiments using this procedure, it was determined that 75% of the G-CSF could be recovered from samples of lung homogenate spiked with a known amount of G-CSF. All measurements of G-CSF in the lungs following aerosol exposure were corrected for this fractional recovery of G-CSF from lung tissue.
An average of 3.1±0.3 μg of G-CSF was deposited in the lung in the group of animals exposed for 11 minutes to an aerosol generated from a 5 mg/mL solution of the protein. An average of 20.0±4.0 μg of G-CSF was deposited in the animal group exposed for 11 minutes to an aerosol generated from a 20 mg/mL solution. Based on the concentration of G-CSF in the aerosol measured during the exposure and the resting ventilation rate (30 mL/min), the animals in the 5-mg/mL group inhaled 22 μg of G-CSF (68 μg/L×0.030 L/min×11 min), and the 20-mg/mL group inhaled 69 μg of G-CSF (208 μg/L×0.030 L/min×11 min) over an exposure period. Using the amounts of G-CSF inhaled and the amounts recovered from the lung, the deposition efficiency (fractional deposition×100) in the lung was estimated to be 14% for the 5-mg/mL group and 29% for the 20-mg/mL group.
The fractional deposition determined from the G-CSF measured in the lungs following aerosol exposure was then used to estimate the G-CSF dose administered by aerosol, in order to relate the increase in the neutrophil concentration to the aerosol dose.
Table 2 contains the inhaled and deposited doses estimated for the aerosol exposures using various concentrations of G-CSF in the nebulizer solution. The G-CSF aerosol concentration was measured gravimetrically from a filter sample collected during the exposure and the weight was corrected for the proportion of surfactant (1 mg/mL) to G-CSF in solution. The inhaled dose was calculated from the aerosol concentration, the resting ventilation rate (30 mL/min), and the exposure period (11 minutes for the Acorn II and 20 minutes for the Ultravent). The deposited dose was calculated from the inhaled dose and the measured fractional deposition (0.29).
TABLE 2______________________________________THE ESTIMATES OF G-CSF DELIVERED TO THELUNG DURING AEROSOL EXPOSURES Mean Estim.Solution Inhaled Body Dose/Conc. [C]* Dose Deposited Weight Body Wt(mg/ml) (μg/L) (μg) Dose (μg) (g) (μg/kg)______________________________________Acorn II Nebulizer1 8 2.6 0.75 66.7 112 10 3.3 0.96 76.3 135 73 24 7.0 92.2 7610 109 36 10 83.3 12515 188 62 18 86.1 209Ultravent Nebulizer1 2.5 1.5 0.44 63.3 6.92 2.7 1.6 0.46 77.1 6.15 33 20 5.7 91.2 6310 41 25 7.1 84.8 8415 38 23 6.6 81.5 81______________________________________ *The filter weight was corrected for 1 mg/ml surfactant to obtain the GCS concentration in the aerosol.
FIG. 3 shows the neutrophil response following subcutaneous injection and the aerosol administration of G-CSF for the dose levels calculated above. Comparing the neutrophil response obtained with an aerosol to that obtained by subcutaneous injection shows that, for the therapeutically important dose range of 1 to 100 μg/kg, the deposited dose is approximately equivalent to an injection.
While this invention has been specifically illustrated with regard to the use of aerosolized solutions and nebulizers, it is to be understood that any conventional means suitable for pulmonary delivery of a biological material may be employed to administer G-CSF in accordance with this invention. Indeed, there may be instances where a metered dose inhaler, or powder inhaler, or other device is preferable or best suits particular requirements. The foregoing description provides guidance as to the use of some of those devices. The application of still others is within the abilities of the skilled practitioner. Thus, this invention should not be viewed as being limited to practice by application of only the particular embodiments described. | Granulocyte-colony stimulating factor (G-CSF) can be delivered systemically in therapeutically or prophylactically effective amounts by pulmonary administration using a variety of pulmonary delivery devices, including nebulizers, metered dose inhalers and powder inhalers. Aerosol administration in accordance with this invention results in significant elevation of the neutrophil levels that compares favorably with delivery by subcutaneous injection. G-CSF can be administered in this manner to medically treat neutropenia, as well as to combat or prevent infections. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of increasing productivity and recovery of wells in oil and gas fields.
Method of the above-mentioned general type are known. A method of hydraulic fracture of underground layers for formation of horizontal slots is known, as disclosed for example in U.S. Pat. No. 3,965,982. In this method upper and lower packers are installed in a well opposite to the layer in contact with a surface of the layer.
Another method for increasing permeability of productive layers is based on introduction of clay wedging agent into a fluid, as disclosed in U.S. Pat. No. 3,976,138.
A further method is used for producing hydraulic fracture in productive layers with the use of viscous solutions of surface-active substances, as disclosed for example in U.S. Pat. No. 4,007,792. With this method a pressure in the well is increased to a value causing formation of cracks in the rock, and the pressure is maintained between 0.5 and 6 hours. The pressure is then reduced, and the material is removed from the well.
Also, a method of multiple fracturing of underground layers is known, in which in order to fracture the layer which is opened by a well, a working fluid is pumped through the well into the layer, and a particulate wedging material is introduced into the cracks. Then a working fluid is pumped through the well into the layer until the layer is fractured, and the particulate wedging material is introduced into the newly formed crack. This method is disclosed in U.S. Pat. No. 3,998,271.
A further method of “wedging” of cracks in productive layers includes introduction of a viscous fluid, so that the hardenable fluid penetrates into the cracks and is retained in them. Then the introduction of the viscous fluid is stopped so that the crack remains open until the hardenable fluid hardens and spreads the crack. This method is disclosed in U.S. Pat. No. 4,029,149.
Finally, a method for fracturing of productive layers by means of an acid foam is known as well. In accordance with this method a gel-like solution having a certain pressure and containing a surface active substance and an inert gas is introduced for forming slots in the layer. This method is disclosed in U.S. Pat. No. 4,044,833. Other methods are known as well.
The known methods are based on the concept of creating a hydraulic connection between a productive layer and a group of layers in a well through a low-permeable or practically impermeable near-well zone which is characterized by increased concentrations of stresses. Even if the near-well zone in the area of a productive layer does not have a poor permeability, the use of hydrofracturing not always leads to positive results. As a rule, the direction of the hydrofracturing changes along the layer, which leads to connection of the layer with water-carrying horizons and stops an industrial flow of oil/gas. In this case it is also not possible to connect simultaneously several wells for performing corresponding works.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method of increasing productivity and recovery of wells in oil and gas fields, which is an improvement of the existing methods.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a method of increasing productivity and recovery of wells in oil and gas fields, comprising the steps of determining a direction of maximal horizontal stresses; producing at least two wells so that they are spaced from one another in a direction corresponding to the direction of the maximum horizontal stresses; forming in at least one of the wells at least one vertical slot oriented substantially from said at least one well toward the other of the wells; and introducing a hydrofracturing fluid at least into said least one well to produce a hydraulic fracture in direction from said at least one well toward said other well.
When the method is performed in accordance with the present invention, a significantly improved interaction of two wells is provided and therefore the productivity and recovery of the wells in gas and oil fields is increased.
In accordance with a further feature of the present invention, slots are formed in two wells and they are directed toward one another, and in particular in direction of the maximum horizontal stresses, and the hydrofracturing fluid is introduced in both wells, which further improves the efficiency of the method.
In accordance with still a further feature of the present invention, additional vertical slots are provided so as to extend substantially perpendicular to the first mentioned slots, with a length corresponding to a part of the length of the above mentioned first main slots, so as to increase a draining surface in the well without affecting the stress condition created by the first mentioned slots.
In accordance with still a further feature of the present invention the method further includes analyzing a plurality of layers; and performing the formation of the slots in a layer which is most efficient for compensating expenses for the slot formation. Therefore, all the expenses related to the process are compensated in the shortest possible time.
In accordance with still a further feature of the present invention, the method includes forming a slot with a slot forming medium; and supplying the slot-forming medium with a maximum pressure producible by an equipment located on a ground. It has been found that when the cutting of slots is performed, (contrary to a universally accepted principle using a pressure calculated in correspondence with the required criteria for cutting,) with a maximum pressure allowed by the equipment, it further increases the productivity.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view schematically illustrating a method of increasing productivity and recovery of wells in oil and gas fields, in accordance with the present inventions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a method of increasing productivity and recovery of wells in oil and gas fields in accordance with the present invention, a hydraulic fracture in a corresponding layer is utilized. In the inventive method first a direction of maximum horizontal stresses is determined. For this purpose, for example, a well 1 is first drilled, and the direction of maximum horizontal stresses can be determined by detecting density of rock which surrounds the well around an axis of the well. The maximum horizontal stress is determined as
δmax= ymax.h,
wherein ymax is a maximum density of the rock determined in a corresponding point around the circumference of the well 1 , and h is a depth of the layer.
A second well 2 is then drilled. The second well 2 is made at the location such that the well 2 is spaced from the well 1 in a direction which correspond to the direction of the maximum horizontal stresses 3 .
In at least one of the wells, for example in the well 1 , a vertical slot 4 is then formed. The slot 4 is formed so that it is oriented toward the second well 2 , or in other words in a direction substantially corresponding to the direction of the maximum horizontal stress.
The slot 4 is cut by one of the known methods, for example by means of a hydraulic sand blasting perforation. A packer with a hydraulic anchor is then placed. A fluid for hydrofracturing is pumped in a space under the packer through corresponding pipes. The moment of the hydrofracture and occurrence of breaking with generation of cracks is determined by reduction of pressure in the system in condition of a constant supply of the pumping fluid. After the hydraulic fracturing, a fluid which carries sand with a binding material is pumped through the pipes, and then a pressing fluid with a volume equal to the volume of the pipes is pumped as well. The hydrofracturing fluid easily overpowers the destroyed zone of increased permeability.
With the inventive method, the work for breaking of the layer and formation of cracks starts beyond the limits of this zone, so that a distance between the wells can be increased. The pressure for the hydrofracturing can be significantly reduced, since the rock is additionally loaded by the maximum horizontal stresses, and in order to provide their extreme condition and their destruction a significantly lower additional action of pressure of the hydrofracturing fluid is needed.
In accordance with a further feature of the present invention, another slot 5 is formed in the second well 2 as well. It is formed so that it is directed toward the well 1 or in other words also in the direction of maximum horizontal stresses. The slot 5 can be produced similarly to the slot 4 . The formation of the second slot 5 additionally improves the orientation of the direction of the hydrofracturing exactly between the wells 1 and 2 . The supply of the fluids in the well 2 can be performed in the same manner as the supply of the corresponding fluids in the well 1 . The operations in the wells 1 and 2 can be performed successively one after the other. In accordance with a preferable embodiment of the present invention, however the operations for providing hydrofracturing in both wells 1 and 2 can be performed simultaneously.
In accordance with another feature of the present invention, when the hydrofracturing is performed from the well 1 , the pressure in the well 2 is depressed. This further increases the efficiency of the hydrofracturing.
In accordance with a further feature of the present invention a hydrofracturing is performed in a layer which is the most efficient for compensation of expenses required for the hydrofracturing. For example, first analysis is performed to evaluate the efficiency of the corresponding layers. Saturation of the layers with oil/gas and capacity of oil/gas in the layers is determined. Based on this determination a layer having a maximum saturation with oil/gas and a maximum oil/gas capacity is selected. Then, the above mentioned hydrofracturing works are performed in the thusly selected layer.
In the hydrofracturing process it has been a long standing concept to select a pressure of the fluid supplied for hydrofracturing in accordance with the parameters of the corresponding layer, in which hydrofracturing is to be performed. In accordance with the present invention, in departure from the long standing concept it, is proposed to supply the hydrofracturing fluid with the maximum pressure which can be achieved by the equipment located on the ground. Therefore, the efficiency of the hydrofracturing is significantly improved.
In the inventive method of increasing productivity and recovery of wells in oil and gas fields, in accordance with another embodiment, it is proposed to form additional slots. As shown in the drawings, one additional slot 6 is formed substantially transverse or perpendicular to at least the slot 4 of the well 1 . The slot 6 have a length substantially corresponding to 20–50% of the length of the slot 4 . The slot 6 is formed so as to increase a draining surface. The slot 6 can be formed in the same manner as the slot 4 .
Substantially similar slot 7 can be formed in the area of the slot 5 of the well 2 . It can have the same length as the slot 6 .
It should be mentioned that the slots 4 , 5 , 6 , 7 are cut over the depth corresponding to the efficient thickness of the corresponding layer.
In accordance with a further feature of the present invention, another well or other wells can be drilled in the same area, as identified with reference numeral 8 . A slot 9 can be then cut from the well 8 (with a slot 10 ), also in a direction corresponding to the direction of the maximum horizontal stresses. When the hydrofracturing fluid is then introduced into the well 8 , the hydrofracturing is also performed in a predetermined direction corresponding to the direction of maximum horizontal stresses. This hydrofracture from the well 8 can reach the area of influence of other wells, thus providing corresponding interactions of the wells.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods differing from the types described above.
While the invention has been illustrated and described as embodied in a method of increasing productivity and recovery of wells in gas and oil fields, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A method of increasing productivity and recovery of wells in oil and gas fields includes determining a direction of maximal horizontal stresses, producing at least two wells so that they are spaced from one another in a direction corresponding to the direction of the maximum horizontal stresses, forming in at least one of the wells at least one vertical slot oriented substantially from the at least one well to the other of the wells, and introducing a hydrofracturing fluid at least into the at least one well to produce a hydraulic fracture in direction from the at least one well to the other well. | 4 |
PRIORITY CLAIM
This application is a national stage entry of International Application No. PCT/DE2011/001690, filed on Sep. 7, 2011, which claims priority to German Patent Application Number DE 10 2010 044 579.7, filed on Sep. 7, 2010. The entire disclosure of each of these applications is incorporated by reference herein.
SUMMARY
The present disclosure provides methods for the modification and cross-linking of polybenzimidazole (“PBI”).
PBI fibers, a product of space exploration in the 1980s, originally served as the upper material of fire protective clothing.
Because of its extraordinary thermal and chemical resistance, PBI has now found its way into the production of fuel cells as a membrane material and is used especially as a material for high-temperature membranes in polymer electrolyte fuel cells (“PEFC”). PBI often serves as a matrix for proton-conducting phosphoric acid because PBI withstands the high temperatures of such fuel cells without problem but is itself a very poor proton conductor, and therefore regularly needs corresponding doping.
Such doping has the advantage that by the choice of a suitable dopant, membranes can be produced for fuel cells for both acidic and alkaline fuels, for example with KOH as a dopant in the case of alkaline fuels.
However, a disadvantage of such doping is the migration of the dopant during operation of the fuel cell, so that the initial high proton conductivity then decreases significantly over the lifetime of the fuel cell.
Another disadvantage is the low mechanical stability of highly doped PBI membranes. This can be encountered, for example, in the case of cross-linking of polymers with difunctional halogen compounds according to U.S. Patent Publication No. 2004/0261616 or difunctional epoxides and isocyanates according to published German Patent Application No. DE 101 10 752 A1. However, in the case of the methods described there, the cross-linking reaction and the competing doping process both take place because of the imidazole functionality, especially in the case of the amine proton.
Against this technical background, the present disclosure provides methods for preparing a modified PBI polymer that is easy to manufacture, and, in particular when used as a starting material for the membrane, can be largely freely functionalized and/or cross-linked.
DETAILED DESCRIPTION
This technical problem is solved by the procedure as disclosed herein.
In one embodiment, a PBI with the structure
is reacted in a solution, with a compound of a halogen and a double bond functionality of the type
where X is a halogen and R an organic group, for example an alkyl halide, in particular 3-bromo-propene, which by a nucleophilic substitution of the amine proton of the benzimidazole functionality enables the modified polymers
to be obtained. The free double bonds are now available for cross-linking or functionalization of the thus modified polymer in a simple manner.
The modified polymers in the form of precipitated powder or granules can be mixed later with a cross-linking agent also in powder form under suitable reaction conditions in order to form a molded part.
If a molded part such as a membrane or a film is produced from the solution, then the modified polymers, in particular allyl-functionalized polymers, can be cross-linked directly or indirectly to one another with or without an initiator, whereby a non-soluble molded part is obtained.
The cross-linking between two modified polymers can be obtained indirectly via a cross-linking molecule having at least two double bonds. After the successful reaction of the original PBI, a compound having a halogen and a double bond functionality is added to the solution, which then has the modified polymers or, after production of a molded part, this may be introduced into a solution together with a component not dissolving the molded part along with the cross-linking agent, and the cross-linking agent diffuses into the molded part. Cross-linking is then obtained again through associated heat treatment.
A particularly stable cross-linking is the direct crosslinking of two modified polymers via two double bonds, which is described below in the explanation of an embodiment.
In one embodiment, a polymer solution with polybenzimidazole having the structure
is obtained by the addition of LiCl to improve the solubility and by the addition of a catalyst, preferably a bicyclic tertiary amine, such as triethylenediamine or 1,4-diazabicyclo[2.2.2]octane or TEDA or DABCO in dimethylacetamide, DMAc, is used as the solvent.
4n 3-bromopropene (allyl bromide) is added as a compound having a halogen and a double bond functionality:
Following a reaction time of about 8 to 24 hours, 4n HBr can be desorbed by heating the solution to about 40° C., and a modified polymer is obtained having the structure
Films can be drawn from the solution and the LiCl washed out.
The subsequent cross-linking is effected in an oven under the influence of temperature to form:
where C-L stands for cross-linking and can represent one of the above-mentioned bonding functions.
Surprisingly, the failure temperature of the modified cross-linked polymers at around 528° C. when tested by thermogravimetric analysis is only slightly lower than that of the original polymers at around 536° C., but this was expected due to the linking of an aliphatic chain.
On the other hand, the behavior of the modified cross-linked polymers when subjected to dynamic mechanical analysis, denotes a significantly higher modulus of elasticity of the modified cross-linked polymers at high temperatures, which indicates very good cross-linking.
Accordingly, in one embodiment, cross-linking can be provided that connects a functional group with at least two double bonds to a double bond of a modified polymer.
Thus from the point of view of acidic membranes for fuel cells, it is considered in particular that the functional group would have a high proton conductivity, such as vinylphosphonic acid, or 1-allyl-3-methylimidazolium chloride.
Thus one obtains an acidic PBI when a stoichiometric amount of vinylphosphonic acid to the allyl units and an initiator such as tert-butyl perbenzoate is added to a 3% aqueous solution of an allyl-functionalized PBI in DMAc as described above.
The reaction solution is heated under nitrogen at 140° C. for 4 hours to reflux.
The functional group may also be an amine group, through which, in particular, the existing alkaline properties of the PBI can be further emphasized. This may be beneficial in the production of H 2 /CO 2 -selective, alkaline then anion-conducting gas-separation membranes.
For such membranes, it may also be advantageous when the functional group is based on an ionic liquid, for example, connected to the allyl-bonding imidazolium. In the case of membranes based on known ionic liquids, it is known that loss of conduction may occur due to migration of the ionic liquid. By using 1-allyl-3-methylimidazolium chloride, one can connect the ionic liquid covalently to the modified polymer, and thus prevent the migration.
In another embodiment, the functional group decreases the degree of crystallization of the polybenzimdazole, for example by the connection of a bulky group such as allylbenzene or allyl p-toluol sulfate.
In addition, the formation of copolymers is not a problem when a monomer having a double bond is connected to the double bond of a modified polymer, which can, for example, take place by means of a radical polymerization.
As an example of functionalization and cross-linking of the modified polymers, reference is also made to the possibility of producing a film or a membrane made from an allyl-functionalized PBI and then soaking it in an appropriate solution, for example, vinylphosphonic acid, if necessary with the addition of a cross-linking agent, in order to obtain a reaction between the allyl function and the vinyl phosphonic acid in an oven and achieve the cross-linking.
Another example of functionalization and linking of the modified polymer is the addition of triallyl isocyanurate, tradename TAIL, known as a co-activator for peroxide cross-linking, which enables a variety of three double bond cross-linking possibilities. Furthermore, triallyl isocyanurate, as a polyfunctional allylic monomer, can itself polymerize or effect a connection of a functional group to one of the double bonds. | The present disclosure provides methods for modifying and cross-linking polybenzimidazoles, PBI. In one embodiment, the polybenzimidazole reacts with a compound, which has a halogen and a double bond functionality and which comprises a halogen and an organic group to form modified polymers by means of a nucleophilic substitution of the amine proton of the benzimidazole functionality in a solution, and a functional group is connected via each resulting free double bond and/or the polymers that are thus modified are cross-linked. | 2 |
The present invention relates to a locking nut and bolt system and a locking nut insert utilized in connection with a specially configured bolt to provide enhanced locking or resistance to counter-rotative motion. A manufacturing process for the locking unit insert is also disclosed.
BACKGROUND OF THE INVENTION
Nut and bolt systems typically compress elements therebetween and mount one component to another component. Sometimes, the mounted assembly is subjected to vibrations which cause counter-rotative torque on the nut and bolt such that the nut loosens on the bolt and the components forming the assembly become loose and unattached. It is helpful to have a locking nut and bolt system and a locking nut insert (operable in conjunction with a specially configured bolt) which prohibits counter-rotative movement and therefore maintains the components in a mounted or fixed assembly.
Various locking nut and bolt systems are disclosed in U.S. Pat. No. 6,010,289 to DiStasio; U.S. Pat. No. RE35,937 to DiStasio; and U.S. Pat. No. 5,951,224 to DiStasio. The content and specification of U.S. Pat. No. 6,010,289 is incorporated herein by reference thereto. U.S. Pat. No. 307,722 to Klemroth discloses bolts having grooves thereon. The following patents disclose the use of bolts carrying grooves and one or more locking tines operative with the grooves on the bolts to prevent or limit loosening of the nut and bolt: U.S. Pat. No. 1,136,310 to Burnett; U.S. Pat. No. 1,226,143 to Stubblefield; U.S. Pat. No. 2,521,257 to Sample; and U.S. Pat. No. 5,238,342 to Stencel.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a locking nut and bolt system (and a locking nut insert) wherein the locking nut insert carries a plurality of locking tines which are not radially symmetrical to each other, thereby enhancing the locking characteristic of the locking nut and bolt system.
It is a further object of the present invention to provide a locking nut and bolt system (and a locking nut insert) wherein the insert is better fixed within the nut due to half-moon cut-out edge segments.
It is a further object of the present invention to provide a locking nut and bolt system with enhanced locking features wherein the locking action of a respective tine in a corresponding bolt groove is asynchronous with respect to other tines and other grooves on the locking unit insert and the bolt, respectively.
It is a further object of the present invention to provide a locking nut insert which is longitudinally split to enhance handling and manufacturing characteristics of the locking unit insert.
SUMMARY OF THE INVENTION
The locking nut and bolt system includes a specially configured bolt operative with an elongated locking unit, which locking unit is mounted in a recess defined on an end face of a nut. The bolt carries a plurality of notches on its threads, which notches are in a predetermined pattern generally longitudinal (which may include spiral or diagonal configurations). The elongated locking unit includes a plurality of at least three tines (in one embodiment) which protrude tangentially and generally radially inward towards the axial centerline of the bolt. The tines, in one embodiment, are radially asymmetrically disposed about the axial centerline such that when a respective tine latches into a corresponding groove, asynchronous locking operation is achieved with respect to the remaining tines and grooves. When the tine falls within the groove, counter-rotational movement (suggesting a loosening of the nut and bolt) is prohibited due to abutment of the distal tine end against the lock face of the groove. In another embodiment, the elongated locking unit has half-moon cut-out edge segments that are swaged to the nut thereby prohibiting the locking unit insert from rotating within the nut recess. Further enhancements include configuring the locking unit as one of an elongated cylinder or an elongated polygonal unit having five or more sides. The elongated locking unit also includes a longitudinal split which enhances handling and manufacture of the locking unit insert. The split may be formed by interleaved surfaces which define opposing sides of the longitudinal split. A key and a keyway may also be formed on the interleaved surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention can be found in the description of the preferred embodiments which follows and in the accompanying drawings which show:
FIG. 1 a diagrammatically illustrates a locking nut and bolt system with the bolt having a straight longitudinal groove thereon;
FIG. 1 b diagrammatically shows a cross-sectional view of the grooved bolt;
FIG. 2 diagrammatically illustrates a grooved bolt with a spiral or somewhat diagonally positioned groove or notched region;
FIGS. 3 a and 3 b diagrammatically illustrate a perspective view of the locking unit insert and a nut thread axial end view of the locking insert, respectively;
FIG. 4 diagrammatically illustrates a plan view of the locking unit insert;
FIG. 5 diagrammatically illustrates a locking unit insert cooperating with a grooved bolt (CR denoting counter-rotative or loosening force) or direction;
FIG. 6A diagrammatically illustrates a detail view of a tine falling into a notch in the notched or grooved bolt;
FIGS. 7 a and 7 b diagrammatically illustrate a portion of the nut, nut recess and a wall segment of the locking nut insert as well as the swage mount of the insert on the nut;
FIG. 8 diagrammatically illustrates a perspective view of the locking unit insert placed in a nut recess prior to swaging; and
FIGS. 9 a and 9 b diagrammatically illustrate polygonal locking inserts representing embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a locking nut and bolt system (including a locking nut insert) with enhanced locking capabilities. A manufacturing process is also described for the locking unit insert.
FIG. 1 a diagrammatically illustrates a bolt 20 having a bolt head 22 and a bolt stem 24 . Bolt 20 includes threads which include thread crests 26 and thread troughs 28 . Nut 40 includes a plurality of threads which are complementary to the thread system 26 , 28 on bolt stem 24 . Axial centerline 60 is related to the axial centerline of the bolt 20 as well as nut 40 . Axial thread end 31 is also shown in FIG. 1 a . Reference to an outboard position of the locking nut insert (not shown in FIG. 1 a ) refers to items closer to axial thread end 31 . The term “inboard” refers to items closer to bolt head 22 .
FIG. 1 b diagrammatically shows a cross-sectional view of grooved bolt 20 . Particularly, thread crest 26 includes a generally longitudinal groove 34 thereat. Groove 34 includes a leading surface 38 and a locking surface 36 . Groove 34 , in a preferred embodiment, does not exceed the thread trough or root 32 of the thread system 26 , 28 . This feature reduces stress fractures which may occur if the groove or notch is deeper than root 32 .
FIG. 2 diagrammatically illustrates a diagonal or a spiral groove 43 on bolt thread 45 . Axial centerline D′–D″ is also shown in FIG. 2 . It should be noted that bolt 20 may contain a plurality of grooves as shown in connection with bolt 20 in FIG. 5 . Further, these grooves are generally longitudinally disposed in a predetermined pattern, which pattern may be limited to a portion of the longitudinal aspect of bolt 20 . In FIG. 1 a , groove 34 does not extend the entire thread portion 26 , 28 of bolt 20 . In other embodiments, the groove may extend the entire thread. Further, adjacent grooves formed on thread crests are generally longitudinally adjacent each other even if slightly arcuately displaced with respect to each other as shown in conjunction with the spiral groove 43 in FIG. 2 .
FIGS. 3 a and 3 b diagrammatically illustrate a perspective view and a thread end axial view of locking unit insert 50 . Locking unit insert 50 is generally cylindrically shaped (but see FIG. 11 a for a different shape) and includes a plurality of at least three tines 52 which are protruding tangentially and generally radially inward towards the axial centerline of the locking nut and bolt system. Tine 52 includes a distal tine end 54 and a proximal base region 56 , which base is attached to or formed by tine wall 58 . Similar numbers designate similar items throughout the figures.
As shown in FIG. 4 , a plan view of locking unit insert 50 , tines 52 are formed by cutting or stamping a U-shape on a strip of metal. Although metal is used in the preferred embodiment, other materials may be employed. In the preferred embodiment, locking unit insert 50 includes a longitudinal split 62 extending the axial length of unit 50 . In a further enhancement, split 62 is formed by opposing sides 64 , 66 . In an enhancement, opposing side 64 forms a key which fits within opposite side 66 forming a keyway. In this manner, key 64 aligns with keyway 66 to form split 62 . Also, the locking unit insert can be slightly compressed thereby reducing its diameter to facilitate insertion of the locking unit into a recess in the nut end face discussed later in conjunction with FIG. 10 . In FIG. 3 b , split 62 is seen as split portion 62 b.
To manufacture locking insert 50 , a flat plate is cut per the plan view in FIG. 4 including stamp-cut tines 52 and key and keyway edge surfaces 64 , 66 . Then the plate is rolled such that key 64 is folded into keyway 66 . See FIG. 3 a . Also, tines 52 are radially inwardly compressed or punched upward from the plate to form the radial tines. The order of plate rolling and punching tines is not critical.
To ensure that the locking unit 50 does not rotate within nut recess, the locking unit on outboard edge 68 includes at least two cut-outs 70 , 72 . These cut-outs are sometimes called herein different sized half-moon cut-out edge segments. Also, cut-outs may be cavities formed by any cutting or forming process. Each cut-out 70 , 72 has a different arcuate length a, b, which further enhances handling of the locking unit insert 50 . In addition, cut-outs 70 , 72 are placed intermediate the various positions of locking tines 52 . The intermediate position of the mounting lock cut-outs 70 , 72 reduces stress and fatigue in the insert during use.
One aspect of the present invention is that the locking tines are radially asymmetrically disposed on locking unit 50 . In other words, distance E between the left side tines 52 is different than distance F between the intermediate tine and the right side tine 52 .
FIG. 5 shows the radially asymmetrical configuration of tines 52 a , 52 b , and 52 c . Further, the locking nature of tine 52 a is asynchronous with respect to the same locking operations of tine 52 b and tine 52 c . In other words, when tine 52 a locks, tines 52 b and 52 c are riding on thread crests or lands 35 b and 35 c . In a similar manner, when tine 52 b locks in groove 34 b , tine 52 c is riding on crest or land 35 c . At that time during counter-rotation CR movement of bolt 21 with respect to locking insert 50 , tine 52 a is on the adjacent left land. Current testing of the locking nut and bolt system indicates that a single tine is sufficient to prevent counter-rotative movement of bolt 21 with respect to locking nut insert 50 . Therefore, radially asymmetric disposition of the tines with respect to each other about the axial centerline is adequate to lock the nut and bolt. Radially asymmetrical disposition is achieved if the arcuate distance between tines 52 a – 52 b is different than the arcuate distance between tines 52 b and 52 c . In one working embodiment, the arcuate distance between tines 52 a – 52 b is the same as the arcuate distance between tines 52 a – 52 c , that being 106.7 degrees for a ⅜ inch bolt. However, since the arcuate distance 52 b – 52 c is not the same as distance 52 a – 52 b (or 52 a – 52 c ), asymmetrical positioning is achieved, resulting in the asynchronous locking of the plurality of tines in the plurality of notches. The tines are not symmetrically located about the axial centerline because 52 b – 52 c is a different arcuate distance than 52 a – 52 b or 52 a – 52 c . Other asymmetrical positions may be utilized.
FIG. 6A diagrammatically shows that tine 52 a is operative in a locking position in groove 34 a . By altering the number of tines and the number of grooves and providing radially asymmetric placement of the tines about the axial centerline, locking action is achieved with a minimal rotational movement in the counter-rotational direction CR (loosening or unscrewing direction). Further, a calculation can establish the maximum unlock arcuate movement necessary before any particular tine falls and locks into a corresponding locking face 36 of a groove. This maximum unlock arcuate distance translates into the maximum seat torque load lost due to counter-rotative movement. Asymmetrical tine placement reduces seat torque load losses. Also, alternatively, asynchronous locking of one tine with respect to others reduces seat torque load losses.
A plurality of tines greater than three may be utilized in radially asymmetric positioning. A plurality of grooves or notches on the bolt thread may also be utilized.
FIGS. 7 a and 7 b diagrammatically show a cross-section of nut 80 having a nut end face 82 . FIG. 9A shows wall segment 81 of locking nut insert 50 . Nut end face 82 has a small build up area 84 . Build up area 84 is subsequently crushed or swaged to capture wall segment 81 . The swaged area 84 b is shown in FIG. 7 b.
FIG. 8 diagrammatically shows locking nut insert 50 placed within recess 86 of nut 80 . Build up area 84 has not been swaged upon half-moon cut-out edge segment 70 of locking nut insert 50 . As is known in the art, nut threads 81 are complementary to bolt threads 26 , 28 in FIG. 1 a . The utilization of outboard cut-out edge segment 70 enables the locking nut insert 50 to be firmly locked or swaged or mounted in nut 80 . The locking of the locking nut insert 50 in nut 80 is important in that the insert should not rotate when the tine falls within the corresponding groove during the prohibition of counter-rotational movement. By utilizing an inboard cut-out edge segment (not shown), additional locking forces are established for the locking nut insert.
FIGS. 9 a and 9 b diagrammatically show locking unit inserts 90 and 92 . These inserts have longitudinal splits 93 . Locking inserts 90 , 92 are shaped as polygons having at least five or more sides. The polygonal shapes enhance handling of the locking nut inserts and insertion into nut recesses 86 .
In FIG. 11 b , inboard edge 94 has been crimped inward to form a radial ledge. This radial ledge may also enhance handling of the locking nut insert during manufacture. Of course, the locking nut insert is mechanically handled by machines and inserted into nut recess 86 . By utilizing radial ledge 94 and detecting radial ledge 94 , the locking insert 92 can be properly placed into nut recess 86 . The utilization of different sized cut-outs 70 , 72 shown in FIG. 4 also enhances handling since the machines can detect the edge 68 having cut-outs 70 , 72 as compared with inboard edge which is opposite edge 68 . Proper insertion of the locking nut inserts into nut recess 86 is important. If the locking nut inserts are placed in nut recess 86 “upside down,” locking is not achieved in the counter-rotational movement direction.
The claims appended hereto are meant to cover modifications and changes within the scope and spirit of the present invention. | The locking nut and bolt system includes an elongated locking unit, mounted in a nut and operative with a specially configured groove bolt. The locking unit includes a plurality of at least three tines, asymmetrically located, which protrude tangentially and generally radially inward. The tines are radially asymmetrically disposed such that when a respective tine latches into a corresponding groove, asynchronous locking operation is achieved. When the tine is engaged in the groove, counter-rotational movement (loosening) is prohibited. In another embodiment, the locking unit has different sized edge cut-outs prohibiting the locking insert from rotating within the nut. The locking unit may also include a longitudinal split and a key and a keyway. A manufacturing process is also disclosed. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to log burning devices, and more particularly to racks used for firelogs to produce an effect similar to that of a wood fire.
Use of firelogs in place of wood logs is growing due to the ease in which firelogs are acquired, stored, and lighted. Firelogs were originally created to recycle sawdust; they burn with significantly fewer pollutants and emissions than natural firewood and are also made of recycled materials. Firelogs are also very popular because they produce less ash, carbon monoxide, and creosote than firewood, resulting in less chimney blockage. But firelogs do not create the same effect as that of a real wood fire. The difference between firewood and firelogs is noticeable.
Many attempts have been made to create burning devices that accommodate firelogs and simulate the appearance of a wood fire. U.S. Pat. No. 5,435,295 to Gerrard, U.S. Pat. No. 5,423,310 to Hudson, and U.S. Pat. No. 5,069,200 to Thow disclose burning devices exemplary of the state of the art. Significantly, all of these burning devices are poorly designed for replenishing a burning fire. The process for replenishing logs in these burning devices involves manually removing the hot artificial logs, adding a fresh firelog, and replacing the hot artificial logs. This complicated method requires a user to work extensively with fire and hot artificial logs, using cumbersome fire tools or even his own hands. This method is laborious and increases the risk of burns.
The burning device disclosed in the Gerrard patent includes a two-tiered rack: the lower tier is for supporting compressed paper logs, and the upper tier is for supporting artificial vacuum-formed ceramic logs. The lighted firelogs burn up through the artificial logs to give the ambience and appearance of a pile of real logs burning. As set forth above, to load firelogs onto a lighted fire, the user must remove the ceramic logs and eventually replace them.
The devices disclosed in the Hudson and Thow patents are for use with gas-fueled fireplaces. Both devices use artificial logs that are positioned individually to achieve the glowing appearance of a wood fire. This is poorly adaptable to firelogs because of the difficulty in replacing the artificial logs after a firelog has been lighted.
SUMMARY OF THE INVENTION
The log burning device of the present invention is easy to use and simulates a natural wood fire in both appearance and generation of heat. Because known burning devices are difficult to use, an easy-to-use burning device that can simulate a natural wood fire and generate a similar amount of heat is still needed. The present invention solves the problems of the aforementioned burning devices.
One preferred embodiment of the present invention is directed to a log burning device that includes a standing grate, which supports at least one log, and a cover attached by at least one hinge to the standing grate. In one preferred embodiment, the cover has the shape of at least one simulated log. When the log burning device contains a lighted firelog, it has the appearance of a burning wood fire.
Another preferred embodiment of the present invention is directed to a method for burning logs, which includes rotating a cover to an open position. A log is then loaded onto the fireplace standing grate and lighted. The cover is then rotated to a closed position.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a log burning device of the present invention in a closed position.
FIG. 2 is a perspective view of the log burning device of the present invention in an open position and of an exemplary opening tool.
FIG. 3 is a side view of the log burning device of the present invention in a closed position with a firelog positioned therein.
FIG. 4 is a side view of the log burning device of the present invention in an open position with a firelog positioned therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIGS. 1-4 show a bottom portion or standing grate 20 of the log burning device 21 of the present invention. Preferably the standing grate 20 is suitable for holding at least one firelog 22 . The standing grate 20 allows ash to fall through and contributes to airflow. A preferred embodiment of the standing grate 20 has two front legs 24 , 26 and two rear legs 28 , 30 . Each rear leg 28 , 30 curves upward to form an arm 32 , 34 each with a hole (not shown) fitted for a hinge 36 , 38 . It should be noted that the shown standing grate is meant to be exemplary and that known standing grates, including but not limited to iron grates, an Eco-Fire grate, a self-feeding fire grate, or the log burning device disclosed in U.S. Pat. No. 4,344,412 to Perrin, may be substituted for the shown standing grate.
Referring to FIGS. 1-4, the upper portion of the invention is preferably a hinge-connected log cover 40 . In the preferred embodiment, the hinged log cover 40 is in the shape of several small simulated logs 42 , 44 , 46 , 48 , 50 . Simulated log 50 lies horizontally at the back of the hinged log cover 40 and is connected perpendicularly to simulated logs 42 , 44 , 46 , 48 . Simulated log 42 is connected to simulated log 44 by appendage 52 . Simulated log 44 is connected to simulated log 46 by appendage 54 . Simulated log 46 is connected to simulated log 48 by appendage 56 . Simulated log 44 has a hole 58 (FIG. 1) that looks like knotted wood. The hole 58 and use of appendages 52 , 54 , 56 to connect simulated logs 42 , 44 , 46 , 48 create cutouts. The hole 58 , cutouts, and other openings allow for escape of smoke and flames and for sufficient airflow. It should be noted, however, that the hinged log cover 40 shown and described is meant to be exemplary. For example, more or fewer simulated logs 42 , 44 , 46 , 48 , 50 can be used depending on the size of the burning device and the effect desired. Further, the simulated logs 42 , 44 , 46 , 48 , 50 can be created in a stacked position to resemble a log pile. The simulated logs 42 , 44 , 46 , 48 , 50 can also be placed so that each would run the length of the cover. The cover can also be made in other decorative and novelty shapes.
Preferably, the hinged log cover 40 is placed substantially over the standing grate 20 and attached by hinge thereto. The right and left sides of the hinged log cover 40 (FIGS. 1 and 2) each have a downward-reaching arm 60 , 62 with a hole (not shown) fitted for hinges 36 , 38 . In the shown embodiment, upward-reaching arm 32 is aligned with downward-reaching arm 60 , and upward-reaching arm 34 is aligned with downward-reaching arm 62 . Hinge 36 is inserted into the respective arm holes to connect upward-reaching arm 32 and downward-reaching arm 60 . A hinge 38 is inserted into the respective arm holes to connect arms 34 and 62 . Once the arms 32 , 34 , 60 , 62 are connected, the hinged log cover 40 is connected to the standing grate 20 and is easily rotated to an open position (FIGS. 2 and 4) and to a closed position (FIGS. 1 and 3 ). Pins (not shown) can be attached to the hinges to secure the hinged log cover 40 to the standing grate 20 . It should be noted that the shown hinges are meant to be exemplary and that known hinges, including but not limited to leaf springs, butt hinges, loose joint hinges, spring hinges, gas springs, or support hinges, may be substituted for the shown hinges. Also, the cover 40 could be hinged only on either the left or the right side so as to lift open to the right or left rather than from front to back. An alternative preferred embodiment would include a sliding cover.
Both the standing grate 20 and the hinged log cover 40 may be constructed from cast iron, metal, or other material able to withstand the heat of a log fire.
When rotated open, the hinged log cover 40 has an open position sufficient to allow at least one log to be inserted. In the preferred embodiment, the cover 40 can be rotated approximately 30° to 120° from the standing grate 20 . In the closed position, the cover 40 is substantially parallel and adjacent to the standing grate 20 .
An opening tool 64 (FIG. 2 ), similar to a fire poker, may be used to move the cover between the open position (FIGS. 2 and 4) and closed position (FIGS. 1 and 3 ). In the shown preferred embodiment, the opening tool 64 is forked and made of cast iron or other material able to withstand the heat of a fire. The exemplary opening tool 64 has a looped handle 66 , making it easy to grasp. In the preferred embodiment, appendage 54 on the hinged log cover 40 provides a catch for the opening tool 64 . It should be noted that the shown opening tool 64 is meant to be exemplary, and that known devices, including but not limited to fire pokers or fire tongs, could be substituted.
In use, the present invention is placed in a fireplace near a rear wall, allowing the invention to be opened and closed. The hinged log cover 40 is rotated to an open position (FIGS. 2 and 4 ), preferably using the opening tool 64 (FIG. 2 ). Next, at least one firelog 22 may be added to the standing grate 20 (FIGS. 3 and 4 ). Once the firelog 22 is lighted and has attained proper ignition, the opening tool 64 is used to rotate the hinged log cover 24 to a closed position (FIGS. 1 and 3 ). It is also possible to close the hinged log cover and then light the firelog. Flames and smoke escape through the openings of the hinged log cover 40 , created by hole 58 and use of appendages 52 , 54 , 56 , creating the appearance of a burning wood fire. To replenish a burning fire, the hinged log cover 40 is rotated to an open position (FIGS. 2 and 4 ), using the opening tool 64 . At least one new firelog 22 is then inserted (FIGS. 3 and 4 ). The hinged log cover 40 is then rotated to a closed position (FIGS. 1 and 3) using the opening tool 64 . This method of using the burning device of the present invention reduces the risk of burns because the user uses the opening tool 64 to rotate the hinged log cover 40 . Further, because the shown hinged log cover 40 is a single unit, the user does not have to replace individual artificial logs, and thus the risk of burns is again reduced.
It should be noted that alternate preferred embodiments simulate, for example, the appearance of wood fires, burning coals, gas fires, debris fires, and other burnings.
The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation and are not intended to exclude equivalents of the features shown and described or portions of them. The scope of the invention is defined and limited only by the claims that follow. | A log burning device that includes a standing grate that supports at least one log and a cover that is attached by at least one hinge to the standing grate. A method for burning logs using a standing grate that has a hinged cover that is attached to the standing grate. The method includes the steps of rotating the cover to an open position, loading at least one log onto the standing grate, lighting the log, and then rotating the cover to a closed position. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my U.S. Patent application Ser. No. 642,907 filed Dec. 22, 1975, now U.S. Patent 3,999,415.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of extrusion and, in particular, to those extrusion processes wherein the object being extruded, e.g. a billet of metal or other extrudable material, is forced through a die by mechanical or hydrostatic means. In particular, the invention pertains to those extrusion processes where successive extrusions are accomplished on the original billet in a step-wise fashion. More particularly, the invention pertains to multiple die arrangements in order to provide greater extrusion reductions on a given extrusion press or apparatus wherein a solid or hollow billet undergoes multiple reductions without increasing the extrusion pressure.
2. Description of the Prior Art
Extrusion processes have been used for many years for producing semi-finished shapes in metals such as bars, wire, tubing, and complicated finished shapes such as H's, angles, and the like. Conventional extrusion processes are employed for both hot and cold extrusion, e.g. where the billet undergoing extrusion is either raised to an elevated temperature or is extruded at ambient, the former being more common for metals and the latter for plastics. The use of an elevated temperature will generally depend upon the material being extruded, the size of the initial billet, and the size and shape being extruded. Both hot and cold processes also encompass the use of lubricants and other aids to minimize the friction between the die and the material being extruded. Conventional extrusion processes are illustrated in U.S. Pat. Nos. 2,123,416 and 2,135,193. Extrusion dies used in such processes, and in particular in a multiple die set are illustrated in U.S. Pat. No. 3,553,996.
More recently, the hydrostatic extrusion technique has become widely adopted for use in extruding materials heretofore difficult to extrude by techniques illustrated by the above patents or materials that, because of their propensity to oxidize at elevated temperature or materials that require closer dimensional control, are better suited to cold extrusion. Generally, cold extrusion of such materials by conventional techniques requires equipment capable of very high extrusion pressures. In the hydrostatic technique, a fluid raised to an elevated pressure forces the billet through the die to achieve the final shape. An excellent discussion of the history of hydrostatic extrusion is contained in the specification of U.S. Pat. No. 3,491,565. Hydrostatic extrusion processes are illustrated in U.S. Pat. Nos. 3,126,096; 3,343,388; 3,677,049; and 3,893,320. One type of hydrostatic extrusion die is illustrated in U.S. Pat. No. 3,583,204.
In addition, materials can be and have been formed into elongated shapes by drawing through a die. Such processes are illustrated in U.S. Pat. No. 3,740,990.
It is well known in the art that the maximum allowable reduction for a billet undergoing an extrusion process is limited by the extrusion pressure applied to the billet as it enters the extrusion die, the billet material flow stress, and the die friction. In both hot and cold extrusion, whether conventional or hydrostatic, the limits of allowable stresses in the components of the extrusion apparatus (extrusion chamber, ram, and dies) restrict the maximum extrusion pressure that can be produced with a given apparatus. Thus, regardless of the design of the extrusion apparatus, the maximum extrusion pressure and resultant reductions accomplished by that pressure are limited by the materials of construction of the apparatus.
The reduction limit means that, for many extruded products, the initial billet must be limited in cross-sectional area, otherwise the reduction will have to be accomplished in successive steps. This size limitation is most severe in conventional and hydrostatic extrusion processes that are carried out at ambient temperature (so-called cold extrusion processes) because of the high flow stress and work hardening of the material being extruded. The advantage of large extrusion reductions, associated with hot extrusions, must be sacrificed if the improvements in tolerances and properties resulting from cold extrusion are desired or necessary. As pointed out above, cold extrusion may be the only process available if the material is one that oxidizes readily, or suffers some other form of degradation, at elevated temperature.
It is well known that hydrostatic extrusion processes are advantageous in that: (1) high pressures can be applied to the billet for greater reduction ratios; (2) there is generally a small die cone angle; (3) the extruded product can be made to close dimensional tolerances; (4) conditions of good lubrication exist; and (5) there is less die wear. However, hydrostatic extrusion may not be available for use with some products because the extruded product volume (primarily determined by the long length required) necssitates an initial billet, which is too large in diameter to be extruded in one step. When hydrostatically extruding certain materials, it becomes necessary to extrude the material into a pressurized container to increase the hydrostatic stress state during the forming operation. This process requires a pressurized container of sufficient size to accept the entire extrusion product which limits the pressure differential across the extrusion die, thus further restricting the reduction ratio between the initial billet and the extrusion product.
One problem often associated with hydrostatic extrusion is the unstable, so-called stick-slip extrusion action, which is usually minimized or eliminated by some form of mechanical action such as pushing on the billet or pulling on the extrusion. This unstable extrusion action is essentially an unsolved problem when large reductions are attempted on cold or elevated temperature (below crystalline melting temperature) polymeric materials using the hydrostatic extrusion process.
SUMMARY OF THE INVENTION
The present invention pertains to a die assembly for use with conventional and hydrostatic extrusion presses wherein the die assembly consists of a first die which yields as a product a first extruded portion of a billet forced through the first die. A second die in the assembly cooperates with the first die to extrude the first extruded portion of the billet to final dimensions. With an assembly according to the present invention, it is possible to take successive reductions by adding additional dies and the means to operate these dies, thus avoiding all extrusion reduction limitations normally associated with conventional and hydrostatic extrusion processes.
The method of the present invention comprises incremental sequential extrusion of the original billet until the final size and shape are achieved. The method does not continuously extrude the billet in the usual sense, rather portions of the billet are extruded sequentially to achieve the final product. Using the method of the present invention helps to minimize and, in a large number of cases, eliminate the stick-slip associated with prior art hydrostatic extrusion processes.
Therefore, it is the primary object of the present invention to provide an improve extrusion process.
It is another object of the present invention to provide an improved die assembly and means for operating the dies for use with conventional and hydrostatic extrusion presses.
It is still another object of the present invention to provide an improved method and apparatus for extrusion which can overcome reduction limitations of conventional apparatus by taking multiple reductions on a billet as it exits from an extrusion chamber with a multiple die arrangement.
It is yet another object of the present invention to provide an extrusion process that can be a combination hydrostatic and conventional die method.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1a, 1b, and 1c are fragmentary sectional views illustrating both the method and apparatus of the present invention.
FIG. 2 is a fragmentary view partially in cross-section of a three-stage hydrostatic extrusion die assembly according to the present invention.
FIGS. 3a, 3b, and 3c are fragmentary cross-sectional views illustrating the pressure balancing die seal assembly of the apparatus of FIG. 2.
FIG. 4 is a fragmentary view partially in section of a combined hydrostatic and conventional extrusion process according to the present invention.
FIG. 5 is a fragmentary view partially in section of the apparatus of FIG. 4 converted to a first and second stage hydrostatic extrusion apparatus.
FIG. 6 is a fragmentary view partially in section of a conventional first-stage extrusion die in combination with a conventional second-stage extrusion die employing the method of the instant invention.
FIG. 7 is a fragmentary view partially in section illustrating a method and apparatus for extruding elongated filamentary material according to the present invention.
FIG. 8 is a fragmentary view partially in section illustrating a method and apparatus for extruding tubular products according to the present invention wherein the inside diameter of the extrusion is constant in each stage.
FIG. 9 is a fragmentary view partially in section illustrating a method and apparatus for extruding tubular products according to the present invention wherein the inside diameter of the extrusion is reduced between stages.
FIG. 10 is a fragmentary view partially in section illustrating a method and apparatus for extruding tubular products wherein a multi-component mandrel is used.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, and in particular to FIGS. 1a, 1b, and 1c, there is shown a cylinder 10 having a first section 12 defining a first, or billet chamber 14. Billet chamber 14 terminates in a die opening 16. Below the die opening 16 is a second section 18 of cylinder 10 defining a receiving or first extrusion product chamber 20 for receiving the extrusion product. Slidably mounted within the opening 20 is a second die or die assembly shown generally as 22 having a die section 24 and a piston section 26. The bottom of cylinder 10 is closed by a suitable plug 28 which defines the one limit of the stroke or path of travel permitted for second die 22. Of course, the upper limit of travel of the die 22 is determined by the bottom or outlet of die opening 16. In referring to a die in the present specification, Applicant means that structure having an inlet opening, a smaller outlet opening, and a deformation zone therebetween as is well known in the art. The present specification is structured so that the dies are vertically oriented with each successive stage below the previous one. The secondary die 22 has a central bore 25 communicating with die opening 30. Die opening 30 is placed so that it is immediately adjacent to die opening 16 and in axial alignment therewith.
Conventional sealing members such as "O"-rings 32, 34, 36, and 38 are provided in suitable grooves or recesses on the secondary die 22 and end closure 28 respectively. Cylinder 10 includes conduits or ports 40, 42, and 44 respectively, the function of which will be explained in detail hereinafter. For illustrative purposes, a reservoir 46, conduits 48, 50, 52 and check valve 56 and valve 54 are shown associated with conduits 42 and 44. With the apparatus illustrated in FIGS. 1a, 1b, and 1c, it is possible to accomplish extrusions in the following manner. Chamber 14 of cylinder 10 defines a high pressure chamber which can be of extended length and closed at a location remote from die opening 16 by a stationary closure (not shown) or moveable ram (not shown) to provide the driving force for the primary extrusion as is well known in the art. Chamber 14 is designed to withstand high operating fluid pressure so that the original billet 60 can be extruded to a reduced section 62 which section size is defined by the die opening 16. The fluid maintained in chamber 14 is pressurized by a ram or external pump as is well known in the art to cause the primary extrusion to proceed at a preselected rate. During this portion of the extrusion cycle, valve 54 is closed, thus maintaining the fluid pressure in chamber 14. As the original billet 60 is extruded through the primary die opening 16, the first or primary extrusion product 62 pushes on secondary die 22 causing it to move in a longitudinal direction. As shown in FIG. 1b, the action of billet section 62 causes the die 22 and piston section 26 to cause a fluid (normally disposed in the annulus defined by piston 26, end closure 28, and the bottom portion of die 22 as illustrated in FIG. 1a, when die 22 is in contact with die opening 16) to be forced through conduit 40 to a reservoir (not shown). Simultaneously, fluid is withdrawn from reservoir 46 through a check valve 56 and conduit 50 through conduit 42 into the cavity defined by primary extrusion 62 and wall 20 of cylinder 10 when the die 22 is in the lowermost position as illustrated in FIG. 1b.
When die 22 completes its stroke by having piston section 26 contact end closure 28, the initial cycle of the primary extrusion stops. At this point, valve 54 is opened so that the cavity defined by wall section 20, first extrusion 62 and the top of die 22 is pressurized with fluid from chamber 14. At this point, fluid is forced through conduit 40, thus causing die 22 to move upwardly against primary extrusion product 62, causing it to flow through die opening 30, thus becoming a seconary extrusion product 64 (FIG. 1c). As secondary die 22 performs the extrusion process on primary extrusion 62, fluid is forced out through conduit 42 through valve 54 through conduits 52 and 44 into cylinder 14, thus maintaining pressure equilibrium in the fluid contained in the chamber 14. The secondary extrusion continues until die 22 has traveled its full stroke as shown in FIG. 1c. At this point, valve 54 is closed and the hydraulic fluid below piston section 26 is depressurized by flowing through conduit 40 into an external reservoir (not shown) and the extrusion through die opening 16 of the billet 60 resumes under the action of the fluid contained in chamber 14. This action initiates another extrusion cycle which continues in accordance with the cycle described hereinabove. Successive extrusion cycles are repeated until the desired amount of original billet 60 is extruded to the final size and shape 64. The process can encompass either complete or partial extrusion of the original billet 60 as desired.
The unstable stick-slip extrusion action, often associated with hydrostatic extrusion, can be controlled by the apparatus as illustrated in FIGS. 1a, 1b, and 1c for the primary extrusion through die opening 16 by controlling the rate at which hydraulic fluid leaves the annulus or secondary pressure chamber 61, defined by piston section 26, closure 28 and the wall of second section 18 of cylinder 10 (FIG. 1c), thereby controlling the rate at which secondary die 22 allows the initial extrusion 62 to flow through the primary die opening 16. Stick-slip extrusion will be eliminated during the second stage extrusion of primary extrusion product 62 through die opening 30 by the inherent stability caused by the fluid pressure in chamber 14 and the fluid pressure above die opening 30 in the chamber defined by primary extrusion 62, chamber 20, and die surface 20, being slightly higher than that required for the unrestricted hydrostatic extrusion of primary extrusion 62 through die opening 10, such that the primary billet 60 is held stationary against die opening 16. It is possible to achieve extrusion through primary die opening 16 against a desired die pressure by providing a restraining action against primary extrusion 62 with the secondary die 22 by maintaining pressure in the fluid below piston section 26 and simultaneously controlling the pressure of the fluid above die opening 30 with an external pressure system (not shown).
In FIG. 2, there is illustrated a three-stage apparatus of the present invention. FIG. 2 serves to illustrate that the number of successive extrusions can be large, being limited only by the size of the apparatus and the material being extruded. The operation of the device of FIG. 2 is similar to that described in connection with FIG. 1, except that pressure equalizing die seals are employed to replace the external conduits and valves used for fluid transfer in the apparatus of FIG. 1. The die seals are shown generally as 70 and 72 of FIG. 2 and they are shown in more complete detail in FIGS. 3a, 3b, and 3c. Only one of the seals is illustrated in FIGS. 3a, 3b, and 3c; the other, acting in an identical manner. Referring now to FIG. 2, the apparatus includes a cylinder 80 having contained therein a two-piece primary die having a lower portion 82 and an upper portion 84 with a micro port therebetween, the port being illustrated by line 86. The upper die 82-84 is sealed within cylinder 80 by pressure equalizing die seal 70. Pressure equalizing die seal 70 communicates with a conduit 88, the purpose of which will be explained more fully hereinafter. Disposed below primary die 82, 84 is a secondary die 90 having associated with it a secondary pressure chamber, the secondary pressure chamber 91 being defined by the bottom of 82, the upper surface of secondary die 90 and the inner wall of cylinder 80, secondary die 90 and tertiary pressure chamber assembly 92 being sealed to the cylinder 80 by pressure equalizing die seal 72. Slidably mounted within tertiary pressure chamber 92 is a tertiary die 94 having a die opening 96 and piston section 98. The cylinder is closed by end closure 105. Tertiary pressure chamber 92 has associated vent conduits 102. Conduit 104 is included through enclosure 100 to enable fluid to be forced against piston section 98 of tertiary die 96. The extrusion process for extruding a billet 110 proceeds as described in relation to FIGS. 1a, 1b, and 1c, except that there are now primary extrusion 112, secondary extrusion 114, and the tertiary or final extrusion 116, all accomplished in sequential fashion as described in relation to FIG. 1.
Referring to FIG. 3, and in particular FIG. 3a, pressure equalizing die seal 70 is illustrated prior to pressurization of fluid contained in the chamber defined by primary die 82, 84 and cylinder 80 and pressure equalizing die seal 70; this chamber being referred to as 120.
The pressure equalizing die seal comprises in combination an "O"-ring 122, a compressible elastomer column 124, miter rings 126, 128, and vent ring 130. As fluid pressure in chamber 120 is increased to effect the primary extrusion, "O"-ring 122 retains the fluid pressure in chamber 120, although the elastomer column 124 is compressed (FIG. 3b). As shown in FIG. 3c, as the pressure in chamber 120 increases with the termination of the primary extrusion caused by secondary pressure chamber 92 contacting end closure 105, the elastomer column 124 is compressed further so that "O"-ring 122 moves past micro port 86 and fluid contained in chamber 120 passes through micro port 86 into the cavity defined by the primary extrusion 122, adjacent die section 82, secondary extrusion die 90, and secondary extrusion chamber 91. Vent 88 is included to prevent fluid pressure from building up in the elastomer column cavity and thus negatively influencing the operation of the pressure equalizing seal. Vent ring 130 is included to aid in minimizing pressure buildup on the elastomer column cavity. Miter rings 126, 138, in cooperation with the design of the vent ring 130, insure that the elastomer column 124 and "O"-ring 122 do not extrude in the low pressure zone of cavity 120.
Referring back to FIGS. 2 and 3, the apparatus operates as follows. As the billet 110 is extruded through primary extrusion die 82, the secondary extrusion die 90 begins to move together with tertiary pressure chamber assembly 92 until the secondary die 90 and tertiary pressure chamber 92 travel the full stroke. After this has taken place, fluid pressure in fluid chamber 120 is increased a small amount (approximately 5% to activate the primary die pressure equalizing seal 70 and allow fluid to flow from chamber 120 through micro port 86 into the cavity between primary extrusion 112 and primary die section 82 then between secondary die 90 and secondary pressure chamber 91. Hydraulic pressure is then applied to the piston supporting secondary die 90 causing secondary die 90 to move against primary extrusion 112 and extruded this section 112 through the secondary die 90 to form secondary extrusion 114. Excess fluid in the cavity between primary extrusion 112 an secondary pressure chamber 91 will flow back through micro port 86 into chamber 120.
After the secondary die has gone its full stroke, the pressure in chamber 120 and surrounding primary extrusion 112 is raised again approximately 5% to activate the secondary die pressure equalizing seal 72 and allow fluid to flow into the cavity surrounding secondary extrusion 114. When the pressure surrounding secondary extrusion 114 is in equilibrium with the remainder of the high pressure fluid system, the low pressure hydraulic system is pressurized through conduit 104 and tertiary extrusion die 94 begins to form tertiary extruded section 116. Upon completion of the tertiary extrusion 116, the primary chamber fluid pressure is reduced to deactivate the pressure equalizing seals, then the secondary and tertiary low pressure hydraulic pressures are reduced to zero gauge pressure. At this point, primary extrusion will again commence and initiate the next extrusion cycle. Extrusion cycles are continued until the desired amount of the original billet 110 is extruded to the final shape 116.
FIG. 4 shows a conventional cold extrusion die as the second stage in conjunction with a primary hydrostatic extrusion die according to the present invention. The modification illustrated in FIG. 4 simplifies the overall apparatus and its operation; however, there is an attendant sacrifice in the lubrication advantage of hydrostatic extrusion, thus making it necessary to apply a suitable lubricant to the billet; the composition and quantity of the lubricant being determined by the billet material and the operational extrusion fluid as is well known in the art. As before, there is a primary cylinder 130 defining a primary extrusion or pressure chamber 132. Cylinder 130 is closed at one end by a first die 134, generally referred to a the primary die. The die 134 is sealed to the cylinder 130 by conventional sealing means such as "O"-ring 136. Chamber 132 is designed to withstand operational fluid pressures so that billet 138 can be extruded through primary die 134 to provide a first extrusion section 140. The operational fluid contained in chamber 132 can be pressurized directly by a ram disposed in the chamber 132 or by sealing the chamber and using a suitable external pump. Billet 138 is extruded at an appropriate rate to provide the primary extrusion 140 which moves secondary die 142 until the piston portion 144 of die 142 reaches the end of its stroke as determined by closure 148, disposed in the end of cylinder 130. The pressure in the fluid-contained chamber 132 is then increased by approximately 5% or more as required to insure that the billet 138 remains in contact with primary die 134 during the secondary extrusion. After the pressure is increased, hydraulic fluid is forced through conduit 150 acting on piston section 144 of die 142 starting secondary extrusion through die 142 producing a product extrusion 152. Secondary extrusion continues until the secondary die 142 travels its full stroke as determined by piston section 144 contacting the bottom of die 134. At this point, hydraulic pressure below piston section 144 of die 142 is reduced to zero or a suitable pressure required for a back pressure extrusion and billet 138 is again forced through primary die 132 by the fluid contained in chamber 132, thus initiating the next step. As before, the cycle continues until the desired amount of billet 138 is extruded to final size and shape.
There is shown in FIG. 5 a modification of the apparatus of FIG. 4 wherein the second stage of the device of FIG. 4 is converted to a second stage hydrostatic extrusion by the addition of "O"-ring seal 159 on secondary die 142. The apparatus of FIG. 5 functions in a similar manner as the apparatus of FIG. 4 until the primary extrusion 10 is completed. At this point, the fluid pressure in chamber 132 is lowered so that, when hydraulic fluid is forced against piston 144 of secondary die 142, the secondary extrusion of primary extrusion 140 through die 142 does not occur. Instead, secondary die 142 moves the product 140 to the position shown in FIG. 5 so that the complete length of primary extrusion 140 is exposed to the fluid pressure contained in chamber 132.
With the hydraulic pressure on piston section 144, sufficient to hold die 142 in place, the pressure of fluid in chamber 132 is raised to cause the primary extrusion product 140 to hydrostatically extrude through die 142. When the billet 138 comes in contact with primary die 134 and extrusion through secondary die 142 stops, the hydraulic pressure on piston 144 is relieved and extrusion of billet 138 through primary die 134 begins, thus starting another extrusion cycle.
An apparatus according to FIG. 4 was constructed and used to extrude an aluminum alloy of the 1100-0 type. A billet 11.0 millimeters in diameter was hydrostatically extruded through the primary die having a die opening of 3.40 millimeters at a fluid pressure of 63.0 kg/mm 2 . The primary extrusion measured 11.4 millimeters in length and was then conventionally extruded to 1.0 millimeters in diameter, 78 millimeters long, by the secondary die at 98.0 kg/mm 2 extrusion pressure. The cycles were successfully repeated to take an overall billet to final product reduction with 99.2% reduction in area of the original billet.
With an apparatus and method according to the invention, it is possible to either use hot or cold extrusion techniques in conjunction with the present invention. The temperature at which the billet is extruded will depend on the material itself together with the reduction desired.
FIG. 6 illustrates the application of the method of the present invention to an apparatus using entirely conventional extrusion which may be carried out at ambient or elevated temperature. Billet 160 is placed into a conventional, cylindrical extrusion chamber 161 and forced through primary die 162 by ram 163. In a manner of operation similar to that presented for hydrostatic extrusion, the desired portion of billet 160 is extruded into primary extrusion product 164 which is in turn extruded through secondary extrusion die 165 to produce secondary extrusion product 166. The secondary extrusion is produced by forcing the secondary die 165 against the primary extrusion product 164 while holding billet 160 stationary with pressure from ram 163. Thus, conventional two-stage extrusion dies can be used to practice the method of the instant invention.
It would also be possible to apply the method of the present invention to extruding long filamentary products, e.g. wire products. In the extrusion of wire products, it may be necessary to provide an intermediate looping chamber to accumulate the previously extruded material prior to the next stage. Such gathering and looping in hydrostatic extrusion of continuous wire is illustrated in FIG. 7 of the drawing.
In the method and apparatus of FIG. 7, extruded filament 172 from a prior extrusion stage having die outlet 171 enters into a fluid-filled cylindrical chamber 170 and forms filament loop 173, shown in dotted lines, with the aid of guide pins 174 and 179. Then, die 175 is forced into chamber 170 causing the fluid therein to be pressurized to a pressure which hydrostatically extrudes filament 172 through die 175, yielding a long, filamentlike extrusion product 178. The die 175 is forced into chamber 170 by the action of die ram 177 which is made fluidtight with the help of "O"-ring 176. The extrusion of filament 172 continues until it is stretched taut across guide pins 174 and 179 (as shown) thereby eliminating loop 173. Simultaneously, fluid pressure in chamber 170 rises above the pressure required to extrude the filament 172 through die 175 causing a slight tension in filament 172. This pressure rise signals the end of this extrusion cycle and the die ram 177 force on die 175 is reduced to zero. The die 175 moves to allow the volume of extrusion chamber 170 to increase and to allow the fluid in chamber 170 to be depressurized. Next, a new filament loop 173 is extruded into chamber 170 to initiate the next cycle.
This invention also applies to the extrusion of products having a hollow cross-section including, inter alia, tubular shapes. Mandrels for controlling the interior dimensions of the hollow products are shown in FIGS. 8, 9, and 10. FIG. 8 illustrates a mandrel 182 which remains stationary with respect to the primary die 181. Hollow billet 180 is hydrostatically extruded through die 181 with mandrel 182 controlling the inside dimensions of the primary extrusion product 185. The mandrel 182 is fixed in the apparatus so that it remains stationary with respect to die 181. Mandrel 182 consists of a cylindrical portion fitting inside hollow billet 180; this cylindrical portion of mandrel 182 terminates at an integral, conical section located inside the deformation zone of die 181. Extending axially from the small end of the conical section is an integral, cylindrical section which extends past the exit of the secondary extrusion die 184. This cylindrical section controls the inside dimensions of the secondary extrusion product 186 as it exits from secondary extrusion die 184.
FIG. 9 shows an extrusion arrangement identical to that of FIG. 8 except that stationary mandrel 187 has been modified. Mandrel 187 consists of a cylindrical section fitting inside the hollow billet 180 which terminates in an integral, conical section as before. However, the cylindrical section extending from the small end of the conical section extends only slightly beyond the primary die 181 outlet before it is reduced in diameter. The reduced diameter section of the mandrel extends through the hollow primary extrusion product 185 and through the secondary extrusion die 184. The reduced diameter of the extension of mandrel 187 results in a reduced inside diameter of secondary extrusion product 188 as it exits from secondary extrusion 184.
FIG. 10 show a two-component mandrel arrangement for a two-stage extrusion of a tubing cross-section using this invention. In this example, the basic process is conventional extrusion. Hollow billet 201 is accepted into the primary extrusion chamber 200 and forced through primary die 206 by a hollow ram not shown. Controlling the inside dimensions of the primary deformation zone of billet 201 as it flows through primary die 206 is the hollow, cylindrical primary mandrel 202, which remains stationary with respect to die 206. The solid cylindrical section of the secondary mandrel 203 slides inside of the primary extrusion mandrel 202 and controls the inside diameter of the primary extrusion product 208 as it exits from the primary die 206 and during the secondary extrusion process of primary extrusion product 208 through secondary die 204. The secondary mandrel 203 is mechanically or hydraulically constrained to move in cooperation with the secondary die 204 always maintaining the same relative position with respect to secondary die 204. The conical section of secondary mandrel 203 and the short cylinder extending from the small end of the conical section controls the inside dimensions of the primary extrusion product as it flows through die 204 and exits as the secondary extrusion product 205.
It is obvious that the die assembly and the method of the present invention can be embodied in various forms and movement of one die relative to the other can be accomplished in numerous ways and in varying sequences without departing from the spirit and scope of the present invention.
Of course, the invention is not limited in any respect to materials of construction, the materials of construction being selected on the basis of the material being extruded.
In all embodiments of the invention, the pistons, cylinders, dies, die holders, rams and the like can be manufactured in multiple parts as is known in the art. While the invention is illustrated with the dies vertically oriented, the orientation of the dies is not critical and they may be operated in a horizontal, vertical, or acute angular position. | Die arrangement for use with conventional and hydrostatic extrusion presses consisting of a first die for providing a first extruded section of a billet and a second die cooperating with the first die to further extrude said first extruded section to final shape. Successive dies beyond the second die are contemplated to provide successive step-wise extrusion for greater reductions, especially of large billets. The method of the invention comprises step-wise incremental sequential extrusion of the billet and extruded portions of the billet until the final shape is achieved. | 1 |
REFERENCE TO PENDING PRIOR PATENT APPLICATION
[0001] This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 62/160,503, filed May 12, 2015 by Diagnosys LLC and Bruce Doran et al. for COMBINED STIMULATOR AND BIPOLAR ELECTRODE ASSEMBLY FOR MOUSE ELECTRORETINOGRAPHY (ERG) (Attorney's Docket No. DIAGNOSYS- 1 PROV), which patent application is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to apparatus and methods for the assessment of electrophysiological signals, and more particularly to apparatus and methods for the assessment of ophthalmic physiological signals.
BACKGROUND OF THE INVENTION
[0003] Full-field ophthalmic electrophysiology generally involves flashing a light from a large “bowl” into the eye of the subject, and then measuring the response from the retina of the subject using electrodes, i.e., an active electrode which contacts the eye of the subject and other electrodes (reference and ground electrodes) which contact other portions of the subject. This procedure is sometimes referred to as electroretinography (ERG).
[0004] Clinically, the hardest part of performing ophthalmic electrophysiology is properly connecting the electrodes to the subject and, more particularly, properly connecting the active electrode to the eye of the subject.
[0005] In some cases the ophthalmic electrophysiology must be conducted on humans. In other cases the ophthalmic electrophysiology must be conducted on small rodents of the sort commonly used in laboratory experiments, e.g., mice and rats (for the purposes of the present invention, such animals will generally be referred to herein as “mice”, however, it should be appreciated that such term is meant to be exemplary and not limiting). It will be appreciated that conducting electrophysiology on mice can present issues which may be different from the issues which might arise when conducting electrophysiology on humans.
[0006] In present configurations for performing ophthalmic electrophysiology on mice, e.g., with an ERG dome such as that offered by Diagnosys LLC of Lowell, Mass., the anesthetized mouse is placed on a heated platform that maintains its body temperature during the test. At least three electrodes must be attached to the mouse: (i) a ground electrode; (ii) a reference electrode; and (iii) a corneal (active) electrode. In best current practice, all three electrodes are made out of platinum or silver/silver chloride and consist of two needles and a wire. One of the needles is used as a ground electrode and is easy to attach to the mouse because its position is not critical—anywhere in the haunch or tail of the mouse will do. Placement of the other two electrodes (i.e., the reference and active electrodes) requires much more care. The remaining needle electrode is the reference electrode. It must be inserted very precisely into the mouse, either at the midline of the scalp, in the mouth, or in the cheek. Mispositioning of the reference electrode will cause imbalances in the readings between the two eyes of the mouse. The last electrode, the wire electrode, is the corneal (active) electrode. It too must be placed in just the right position on the eye in order to avoid biasing the recording: too close to the center of the eye and the wire will block light; too far to the periphery of the eye and the wire will record lower voltages than if placed nearer to the center of the eye. If both eyes of the animal are to be tested, a second corneal wire must be placed in a homologous position to the first corneal wire. An added complication is that, usually, all this must be done in a room only dimly illuminated by deep red light.
[0007] After the three electrodes have been placed on the mouse, the ERG dome is either moved into position over the mouse or the platform supporting the mouse is moved into the dome. Either movement may disturb the electrodes placed on the mouse, which would then require that the electrodes be repositioned. Since the mouse is hidden by the dome, it sometimes wakes up and escapes under cover of darkness.
[0008] FIG. 1 shows the current Diagnosys mouse ERG dome platform in its open position.
[0009] FIG. 2 shows the same Diagnosys mouse ERG dome platform in its closed position.
[0010] It will be appreciated that conducting ophthalmic electrophysiology on a mouse is time-consuming and requires personnel with special skills. For this reason, ophthalmic electrophysiology is sometimes not performed on mice even where the results of performing ophthalmic electrophysiology could be beneficial. By way of example but not limitation, NIH has an impending campaign to phenotype more than 300,000 mutated mice. Among other things, the mice are being tested for deficits analogous to human eye disease. Although some of these deficits can only be detected using ophthalmic electrophysiology, electrophysiology was initially excluded from the testing protocols because existing techniques for performing ophthalmic electrophysiology on mice are too time-consuming and require personnel with rare skills.
[0011] Ophthalmic electrophysiology would be significantly easier to perform on mice if there were a way to rapidly and automatically position the active and reference electrodes on the mouse. There is an existing device (a “contact lens bipolar corneal electrode”) that does this effectively for humans, but in its present state the contact lens bipolar corneal electrode is not practical for widespread use with mice.
[0012] More particularly, a contact lens bipolar corneal electrode consists of a lid-retracting speculum with a reference electrode embedded in its outer circumference. A contact lens ringed by the corneal electrode is suspended by a spring from the inner part of the speculum. Since both active and reference electrodes are built into the device, the two electrodes occupy the same position on every eye (which is easily adjusted during manufacture to be at the correct position on the eye of the subject). As a result, the contact lens bipolar corneal electrode provides highly reliable positioning of the active and reference electrodes, and hence provides highly reliable results. A further advantage of the contact lens bipolar corneal electrode is that both electrodes (active and reference) touch the tear film, making excellent electrical contact with the subject without special preparation.
[0013] FIG. 3 shows a human contact lens bipolar corneal electrode which was introduced by Diagnosys in 1986 .
[0014] FIG. 4 shows another human contact lens bipolar corneal electrode sold by Hansen Ophthalmic Development Laboratories of Coralville, Iowa (hereinafter “Hansen Labs”).
[0015] As noted above, human contact lens bipolar corneal electrodes work effectively, but mouse contact lens bipolar corneal electrodes are impractical for widespread use with mice. More particularly, a mouse contact lens bipolar corneal electrode is available from Hansen Labs, but the mouse contact lens bipolar corneal electrode is impractically delicate, expensive, and hard to make. The basic problem with the mouse contact lens bipolar corneal electrode sold by Hansen Labs is that the manufacturer does not know how its customers are going to use the lens—they may have an application that needs the animal to view an image—and so the manufacturer has to start by wrapping a corneal electrode around an optically “good”, zero-power mouse contact lens, and this is a challenging task.
[0016] Another problem with mouse contact lens bipolar corneal electrodes is that, if anything, they slow the testing process down rather than speed it up. The mouse contact lens bipolar corneal electrodes are so delicate and sensitive that they require great care and skill in order to place them properly on the eye of the mouse—by way of example but not limitation, it is very easy to accidentally cover the mouse contact lens bipolar corneal electrodes with saline solution which shorts them out, and they often break during handling. In any case, mouse contact lens bipolar corneal electrodes are so hard to make that they are usually now offered only in monopolar versions, which means that the problem of placing the reference electrode on the mouse is still left to the user. The only real advantage of current mouse contact lens bipolar corneal electrodes over current wire electrodes is that the mouse contact lens bipolar corneal electrodes cover the cornea and prevent the formation of cataracts in the mouse due to drying.
[0017] FIG. 5 shows the mouse contact lens bipolar corneal electrode sold by Hansen Labs.
[0018] Thus there is a need for a new and improved approach for quickly and easily performing ophthalmic electrophysiology on mice.
SUMMARY OF THE INVENTION
[0019] The present invention comprises the provision and use of a new and improved method and apparatus for quickly and easily performing ophthalmic electrophysiology on mice.
[0020] In one form of the present invention, there is provided apparatus for evoking and sensing ophthalmic physiological signals in an eye, the apparatus comprising:
[0021] an elongated tubular light pipe having a longitudinal axis, a distal end and a proximal end, the distal end terminating in a spheroid recess;
[0022] an active electrode having a distal end and a proximal end, the active electrode being mounted to the elongated tubular light pipe and extending proximally along the elongated tubular light pipe so that the distal end of the active electrode terminates at the spheroid recess at the distal end of the elongated tubular light pipe; and
[0023] a reference electrode having a distal end and a proximal end, the reference electrode being mounted to the elongated tubular light pipe and extending proximally along the elongated tubular light pipe so that the distal end of the reference electrode terminates at the spheroid recess at the distal end of the elongated tubular light pipe;
[0024] wherein the distal end of the active electrode is located closer to the longitudinal axis of the elongated tubular light pipe than the distal end of the reference electrode.
[0025] In another form of the present invention, there is provided a method for evoking and sensing ophthalmic physiological signals in an eye, the method comprising:
[0026] providing apparatus comprising:
an elongated tubular light pipe having a longitudinal axis, a distal end and a proximal end, the distal end terminating in a spheroid recess; an active electrode having a distal end and a proximal end, the active electrode being mounted to the elongated tubular light pipe and extending proximally along the elongated tubular light pipe so that the distal end of the active electrode terminates at the spheroid recess at the distal end of the elongated tubular light pipe; and a reference electrode having a distal end and a proximal end, the reference electrode being mounted to the elongated tubular light pipe and extending proximally along the elongated tubular light pipe so that the distal end of the reference electrode terminates at the spheroid recess at the distal end of the elongated tubular light pipe; wherein the distal end of the active electrode is located closer to the longitudinal axis of the elongated tubular light pipe than the distal end of the reference electrode;
[0031] positioning the elongated tubular light pipe against the eye of a test subject; and
[0032] introducing light into the proximal end of the elongated tubular light pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:
[0034] FIGS. 1 and 2 are schematic views of a prior art rodent table for the ColorDome Stimulator of Diagnosys LLC;
[0035] FIG. 3 is a schematic view of a prior art GoldLens Corneal Electrode;
[0036] FIG. 4 are schematic views showing prior art Burian speculum type electrodes and prior art cotton wick electrodes;
[0037] FIG. 5 is a schematic view showing a prior art mouse ERG electrode;
[0038] FIGS. 6-12 are schematic views showing novel apparatus formed in accordance with the present invention for evoking and sensing ophthalmic physiological signals in an eye;
[0039] FIG. 13 is a schematic view showing an alternative form of the apparatus shown in FIGS. 6-12 ;
[0040] FIG. 14 is a schematic view showing another alternative form of the apparatus shown in FIGS. 6-12 ; and
[0041] FIGS. 15-17 are schematic views showing exemplary novel apparatus formed in accordance with the present invention for evoking and sensing ophthalmic physiological signals in an eye.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The present invention provides a new and improved approach for quickly and easily performing ophthalmic electrophysiology on mice.
[0043] More particularly, and looking now at FIGS. 6-11 , there is shown a combined stimulator and bipolar electrode assembly 5 formed in accordance with the present invention. Combined stimulator and bipolar electrode assembly 5 generally comprises a housing 10 , a light pipe subassembly 15 and a light source subassembly 20 .
[0044] Housing 10 preferably comprises a main body 22 having a cavity 25 formed therein, and a side arm 30 extending at an angle (e.g., 125 degrees) to the longitudinal axis of main body 22 . Side arm 30 includes a cavity 35 formed therein, and a magnetic mount 40 (preferably in the form of a steel ball) secured to side arm 30 .
[0045] Light pipe subassembly 15 is disposed partially within, and protrudes from, cavity 25 of main body 22 . Light pipe subassembly 15 generally comprises a light pipe 45 formed out of a light-transmissive material (e.g., Plexiglass) and having a distal end 50 and a proximal end 55 . Light pipe 45 has an elongated configuration, and may be cylindrical (e.g., substantially straight with a substantially circular cross-section), or non-linear pseudo-cylindrical (e.g., bent or curved with a substantially circular cross-section), or light pipe 45 may have another acceptable configuration. Distal end 50 of light pipe 45 has a spheroid recess 60 formed therein. The radius of curvature of spheroid recess 60 is preferably similar to the radius of curvature of the eye of a mouse, so that the distal end 50 of light pipe 45 can be seated against the outside surface of the eye of a mouse. Light pipe 45 also comprises a pair of slots 65 A, 65 B formed in the outer surface of light pipe 45 . In one preferred form of the invention, slots 65 A, 65 B are diametrically opposed to one another. The distal end of slot 65 A has a greater depth than the remainder of slot 65 A, so that the distal end of slot 65 A approaches (but preferably does not reach) the center of spheroid recess 60 . Preferably at least the distal portion of slot 65 A outboard of wire 70 A is filled with an appropriate material (e.g., a light-transmissive, non-conductive, waterproof material) so as to eliminate air gaps between light pipe 45 and the eye of the mouse. A platinum (or silver or gold, etc.) wire 70 A, which serves as the active electrode for combined stimulator and bipolar electrode assembly 5 , is disposed in slot 65 A. Note that the distal end of platinum wire 70 A follows the floor of slot 65 A so that the distal end of platinum wire 70 A approaches the center of spheroid recess 60 . The distal end of platinum wire 70 A communicates with spheroid recess 60 . A platinum (or silver or gold, etc.) wire 70 B, which serves as the reference electrode for combined stimulator and bipolar electrode assembly 5 , is disposed in slot 65 B. The distal end of platinum wire 70 B also communicates with spheroid recess 60 . Preferably at least the distal portion of slot 65 B outboard of wire 70 B is filled with an appropriate material (e.g., a light-transmissive, non-conductive, waterproof material) so as to eliminate air gaps between light pipe 45 and the eye of the mouse. Note that the distance between the distal end of platinum wire 70 A (which will act as the active electrode) and the distal end of platinum wire 70 B (which will act as the reference electrode) is substantially equal to the distance between a portion of the eye which exhibits an evoked physiological signal and a portion of the eye which exhibits a lesser evoked physiological signal (or, preferably, does not exhibit an evoked physiological signal), e.g., the distance between the cornea and the perimeter of the eye. The intermediate portions of platinum wires 70 A, 70 B may be held to the body of light pipe 45 with shrink bands 75 . The proximal end 55 of light pipe 45 is disposed in cavity 25 of main body 20 , and the proximal ends of platinum wires 70 A, 70 B are passed through cavity 35 of side arm 30 so that they can be brought out the proximal end 80 of side arm 30 for connection to appropriate amplification (e.g., by a differential amplifier) and processing electronics (not shown) for ERG signal processing.
[0046] Light source subassembly 20 is disposed within cavity 25 of main body 20 . Light source subassembly 20 generally comprises LEDs 85 for generating light, and any appropriate optics (not shown) required to transmit the light generated by LEDs 85 into the proximal end 55 of light pipe 45 , whereupon the light will travel down the length of light pipe 45 to the distal end 50 of light pipe 45 . A power line 90 provides power to LEDs 85 . Preferably a wire mesh 95 (or similar element) is provided distal to LEDs 85 and proximal to platinum wires 70 A, 70 B so as to provide electromagnetic interference (EMI) shielding between LEDs 85 and platinum wires 70 A, 70 B.
[0047] It will be appreciated that, on account of the foregoing construction, combined stimulator and bipolar electrode assembly 5 can be supported via its magnetic mount 40 for use with an ERG mouse platform, with the proximal ends of platinum wires 70 A, 70 B being connected to appropriate amplification and processing electronics for ERG signal processing, and with power line 90 being connected to an appropriate source of power. When a mouse is to be tested, the mouse is placed on the ERG mouse platform, a ground electrode (not shown) is attached to the mouse, and then housing 10 can be moved so as to bring the distal end 50 of light pipe 45 into contact with the eye of the mouse. This action will position the distal end of platinum wire 70 A (i.e., the active electrode) at the appropriate position on the eye of the mouse, and will simultaneously position the distal end of platinum wire 70 B (i.e., the reference electrode) at another appropriate position on the eye of the mouse. When LEDs 85 are thereafter energized, the light from LEDs 85 passes down light pipe 45 and into the eye of the mouse, whereby to stimulate the eye of the mouse. Platinum wires 70 A (i.e., the active electrode) and 70 B (i.e., the reference electrode) pick up the electrophysiological response of the eye of the mouse as electrical signals, and these electrical signals are passed along platinum wires 70 A, 70 B to appropriate amplification and processing electronics for ERG signal processing.
[0048] Thus it will be seen that with the combined stimulator and bipolar electrode assembly 5 of the present invention, the assembly simultaneously provides (i) the stimulator needed for conducting ophthalmic electrophysiology on a mouse (i.e., LEDs 85 and light pipe 45 ), (ii) the bipolar electrode needed for conducting ophthalmic electrophysiology on a mouse (i.e., platinum wires 70 A, 70 B supported by light pipe 45 ), and (iii) the support structure (e.g., magnetic mount 40 ) for holding the bipolar electrode securely against the eye during testing.
[0049] Significantly, mounting platinum wires 70 A, 70 B to the light pipe 45 provides a robust mechanical support for the platinum wires, making it possible to quickly, easily and precisely position the active electrode (i.e., platinum wire 70 A) and the reference electrode (i.e., platinum wire 70 B) on the eye of the mouse. At the same time, the small acceptance angle of light pipe 45 restricts the light reaching the eye of the mouse to that generated by LEDs 85 , which eliminates the normal need for a large Ganzfeld to conduct ophthalmic electrophysiology. Note that LEDs 85 may be a three-color RGB system, although UV could also be used and would be desirable in mice. In one preferred form of the invention, appropriate electronic drivers are provided to drive RGB LEDs 85 accurately enough to form precisely-defined metameric colors. If desired, and looking now at FIG. 12 , light pipe 45 may comprise a main body 45 A and an end diffuser 45 B. End diffuser 45 B can, advantageously, help provide full retinal illumination. More particularly, end diffuser 45 B acts to broaden the angle at which light exits main body 45 A of light pipe 45 and enters the eye of the mouse, and ensures that light exiting the light pipe is distributed equally to all parts of the retina of the mouse. The diffusing material of end diffuser 45 B is preferably of non-uniform thickness, i.e., it is made thinner at the edges to compensate for the lower flux density occurring at the perimeter of the light pipe. Furthermore, if desired, reference electrode 70 B may be “doubled over” so as to increase the surface area contact of reference electrode 70 B with the eye of the mouse. And, if desired, and looking now at FIG. 13 , a conductive foil (or conductive film) 100 may be provided at distal end 50 of light pipe 45 , with conductive foil (or conductive film) 100 electrically connected to reference electrode 70 B so as to increase the surface area contact of reference electrode 70 B with the eye of the mouse.
[0050] In some cases, it can be helpful to provide the user with “red light” illumination to help the user set the combined stimulator and bipolar electrode assembly 5 against the eye of the mouse. To this end, if desired, and looking now at FIG. 14 , a light-transmissive sleeve 105 may be disposed coaxially about light pipe 45 , with light-transmissive sleeve 105 acting as an additional light pipe for delivering red light to the distal end of light pipe 45 . More particularly, in this form of the invention, when red light is introduced into the proximal end of light-transmissive sleeve 105 , a ring of red light will be provided at the distal end of light-transmissive sleeve 105 , whereby to provide a rim of red illuminating light about the distal perimeter of light pipe 45 .
[0051] The combined stimulator and bipolar electrode assembly 5 of the present invention can be set up not only more accurately, but also much more quickly, than the present state-of-the-art, even by relatively unskilled personnel. After positioning the mouse on the heated table described above and inserting the ground electrode (e.g., in the haunch or tail of the animal), the combined stimulator and bipolar electrode assembly 5 is simply brought into contact with the eye of the mouse by moving housing 10 (which causes magnetic mount 40 , e.g., a steel ball, to roll within a magnetic cup, e.g., a magnetic ball holder (see FIG. 1 above, which shows a magnetic ball holder of the sort which may be used), and then the test is ready to run. A second device can be used simultaneously on the fellow eye (i.e., the other eye of the mouse) if desired. This eliminates several minutes fumbling in near darkness to carefully adjust the electrodes and position the Ganzfeld. Additionally, since light pipe subassembly 15 is held in position against the eye by an external mechanical mount (i.e., magnetic mount 40 ) and is not supported by the eye per se, it is not necessary to use particular care to position combined stimulator and bipolar electrode assembly 5 precisely against structurally robust eye tissue. Furthermore, since light pipe subassembly 15 has no accessible distal surface once it is seated against the eye, it is substantially impossible to obscure the light path from light pipe subassembly 15 into the eye by the use of excessive saline.
[0052] Testing of the combined stimulator and bipolar electrode assembly 5 on mice has yielded excellent results. It produces expected waveforms with very little noise, although the overall amplitude of the waveforms is small.
[0053] In addition to the foregoing, some investigators have used an active electrode in one eye, and a reference electrode in the other eye. This technique still involves accurate placement of two corneal wires (extremely challenging with prior art electrodes), but the fellow eye makes an excellent impedance-matched reference. However, with this approach, care must be taken to avoid light crosstalk between the eyes—the reference eye must not receive any stimulus light.
[0054] Using the combined stimulator and bipolar electrode assembly 5 of the present invention solves both problems (i.e., accurate placement of electrode and avoiding light crosstalk between the eyes). More particularly, in one form of the invention, the corneal electrode 70 A of, for example, the right eye is plugged into the active side of the differential amplifier, and the corneal electrode 70 A of the left eye into the reference side of the differential amplifier. The electrodes in each eye are automatically correctly positioned. The eyes are then stimulated one at a time using the light source subassemblies 20 of the combined stimulator and bipolar electrode assemblies 5 , and there is no optical crosstalk because of the light pipe configuration (i.e., the positioning of a light pipe on an eye of the mouse limits the light reaching that eye of the mouse to only the light transmitted by that light pipe). When the right eye is being driven, the signal is normally polarized, and when the left eye is being driven, the signal is inverted. Alternatively, both eyes of the mouse could be simultaneously stimulated using light source subassemblies 20 of the combined stimulator and bipolar electrode assemblies 5 , and the differential between the two corneal electrodes 70 A may be measured so as to identify differences in eye function.
[0055] Alternatively, the reference electrodes 70 B may be used in place of the corneal electrodes 70 A. In this form of the invention, the reference electrode 70 B of, for example, the right eye is plugged into the active side of the differential amplifier, and the reference electrode 70 B of the left eye is plugged into the reference side of the differential amplifier. The electrodes in each eye are automatically correctly positioned. The eyes are then stimulated one at a time using the light source subassemblies 20 of the combined stimulator and bipolar electrode assemblies 5 , and there is no optical crosstalk because of the light pipe configuration (i.e., the positioning of a light pipe on an eye of the mouse limits the light reaching that eye of the mouse to only the light transmitted by that light pipe). When the right eye is being driven, the signal is correctly polarized, and when the left eye is being driven, the signal is inverted. Alternatively, both eyes of the mouse may be simultaneously stimulated using light source subassemblies 20 of the combined stimulator and bipolar electrode assemblies 5 , and the differential between the two reference electrodes 70 B may be measured so as to identify differences in eye function.
[0056] In one preferred form of the invention, and looking now at FIGS. 15-17 , platinum wire 70 A can be omitted and platinum wire 70 B can be provided with a conductive foil (or conductive film) 100 . When configured in this manner, the present invention essentially comprises a combined stimulator and monopolar electrode assembly. This form of the invention can be advantageous where combined stimulator and monopolar electrode assemblies are positioned against both eyes of the mouse (for stimulating one eye at a time or for simultaneously stimulating both eyes at the same time).
[0057] The robustness of the electrical and optical connections that the new combined stimulator and bipolar electrode assembly 5 makes with the mouse has been dramatically demonstrated during testing. Toward the end of testing, the mice may wake up and begin to move. With conventional setups, the first movement of the awakening mouse breaks corneal contact and the testing is over. With the combined stimulator and bipolar electrode assembly 5 of the present invention, contact with the awakening mouse was successfully maintained even though the mouse was moving and testing continued with good results until the mouse literally walked away.
[0058] In the foregoing disclosure, platinum wire 70 A (i.e., the active electrode) is disposed within slot 65 A which extends along an outer surface of light pipe 45 , and platinum wire 70 B (i.e., the reference electrode) is disposed within slot 65 B which extends along an outer surface of light pipe 45 . However, if desired, slot 65 A could be replaced with a bore extending longitudinally through light pipe 45 and platinum wire 70 A (i.e., the active electrode) may be disposed within this longitudinal bore, and/or slot 65 B could be replaced with another bore extending longitudinally through light pipe 45 and platinum wire 70 B (i.e., the reference electrode) may be disposed within this other longitudinal bore. In such a construction, the longitudinal bore receiving platinum wire 70 A (i.e., the active electrode) is disposed closer to the longitudinal axis of light pipe 45 than the longitudinal bore receiving platinum wire 70 B (i.e., the reference electrode).
Modifications Of The Preferred Embodiments
[0059] It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention. | Apparatus for evoking and sensing ophthalmic physiological signals in an eye, the apparatus comprising: an elongated tubular light pipe having a longitudinal axis, a distal end and a proximal end, the distal end terminating in a spheroid recess; an active electrode having a distal end and a proximal end, the active electrode being mounted to the elongated tubular light pipe and extending proximally along the elongated tubular light pipe so that the distal end of the active electrode terminates at the spheroid recess at the distal end of the elongated tubular light pipe; and a reference electrode having a distal end and a proximal end, the reference electrode being mounted to the elongated tubular light pipe and extending proximally along the elongated tubular light pipe so that the distal end of the reference electrode terminates at the spheroid recess at the distal end of the elongated tubular light pipe; wherein the distal end of the active electrode is located closer to the longitudinal axis of the elongated tubular light pipe than the distal end of the reference electrode. | 0 |
RELATED APPLICATIONS
[0001] The present application claims the benefit of provisional patent application Ser. No. 61/107,833 filed Oct. 23, 2008 entitled “Method and Apparatus for Soil Excavation using Supersonic Pneumatic Nozzle with Wear Tip and Supersonic Nozzle with Wear Tip for use therein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to soil excavation using supersonic nozzles, in particular to a method and apparatus for soil excavation using supersonic pneumatic nozzle with wear tip and supersonic pneumatic nozzle with wear tip for use therein.
[0004] 2. Background Information
[0005] U.S. Pat. No. 5,782,414, which is incorporated herein by reference, notes that it has been well known that compressed air released in close proximity to and directed toward the ground can result in loosening of a number of types of soil. A pneumatic soil excavation tool, also called a wand, consisting of a valve, length of pipe or tubing, and ending in a reduced sized nipple or nozzle, supplied with air from a standard portable compressor, is commonly used for the purposes of dislodging soil safely from around underground utilities such as gas, water, or sewer pipes and electric, telephone, television, or other cables. The compressed air does not pose a hazard of damaging the buried utility as does a pick, digging bar, spade, bucket, or blade.
[0006] The ability to unearth safely other types of buried objects is also important. For example, in the industrial or nuclear energy sectors, such objects include glass bottles, cardboard or wood boxes, metal or fiber drums, or metal cylinders of chemical or radioactive waste. From the military sector, objects include all types of unexploded ordnance or chemical munitions.
[0007] A number of tools have been marketed produce an air stream for improved digging purposes by making the air exit the tool at a supersonic speed. For example, U.S. Pat. No. 4,813,611, which is incorporated herein by reference, discloses a compressed air nozzle for use in soil excavation to uncover buried pipes, electrical cables and the like. U.S. Pat. No. 5,170,943 discloses a similar tool with a handle, valve, electrically insulating barrel, and a nozzle. The '943 patent includes a conical shield to protect the operator, but nothing to protect the nozzle. U.S. Pat. No. 5,212,891 discloses a further excavating pneumatic nozzle design.
[0008] Air excavation nozzles should not be confused with the rocket nozzles. Supersonic air excavation nozzles used for excavation purposes are different than rocket nozzles in a number of important ways. Supersonic air nozzles for earth excavation operate at significantly lower pressures and temperatures than rocket nozzles. For example, a rocket's chamber pressure may reach 1,000 to 3,000 psig and the exhaust gas temperature may be 1,800° to 7,700° F., while typical gas jet excavation nozzles operate at around 100 to 200 psig and at 80° to 140° F. The velocity of the exhaust gas exiting from a chemical rocket's nozzle may be from 6,000 to 14,000 ft/sec; while for an excavation nozzle typical values are from 1,700 to 2,000 ft/sec. The specific nozzle profile for a typical rocket nozzle is, thus, significantly different in shape than for an air excavation nozzle.
[0009] U.S. Pat. No. 6,845,587 describes the practices of revival woody plants that are in decline, which is usually preferred to replanting. Revival avoids costs for removal and additional costs for replacement. Typically, revival has meant either aggressively fertilizing the subject plant and/or loosening the soil. Revival success is dependent on the degree of soil compaction and existing moisture content. Earlier methods include laboriously exposing roots using trowels and small digging implements. Once exposed, the roots were reburied with new loose soil or covered with the existing soil now more loosened. This early, labor intensive method is similar to the way archeologists dig for shards of pottery—slow and tedious. An improvement over manual excavation is a vertical mulching technique where a grid of 1 to 2 inch holes is drilled in the rooting soil. The holes are then backfilled with porous material and/or fertilizer.
[0010] One technique of soil loosening uses compressed air. Compressed air released at supersonic speed fractures the soil, with minimal damage to roots. Unlike porous soil, non-porous matter, such as roots, remain minimally damaged by the compressed air. Soil fracturing avoids the problems of mechanical excavation.
[0011] Fracturing soil by using compressed air is popularly used on lawns and turfs, such as golf courses. To maximize efficiency compressed air is injected in a grid. The grid is spaced so to aerate the soil evenly throughout a specified area by fracturing the soil.
[0012] Specifically U.S. Pat. No. 6,845,587 provides for the provision of a method of improving the rooting soil of a woody landscape plant comprising the steps of exposing a root collar of a plant; defining a first improvement zone encompassing the root plate area; excavating the first improvement zone with an air excavator; and adding a beneficial treatment to the first improvement zone.
[0013] The above description illustrates the growing applications for pneumatic supersonic soil excavation tools. However, the observation and analysis of damage to the exterior of various supersonic nozzles, particularly the relatively rapid failure of nozzles used during excavation of the ground, has demonstrated a need for improvement. The damage to the nozzle exterior is best described as erosion, presumably as the result of back flow of hard particles in the soil that impact the nozzle exterior with sufficient velocity and hardness to wear away (erode) the nozzle exterior. This blow back does not erode the nozzle expansion exit because the air jet coming from the nozzle expansion exit is the highest velocity in the nozzle region, and any nearby rebounding air/particles are simply drawn into the exiting air stream before it/they can reach the nozzle expansion exit. But the backflow air, when it contains sufficiently hard particles, and sufficient velocity, can and will erode the nozzle exterior.
[0014] The supersonic exit stream from the nozzle begins losing velocity, and thus digging effectiveness, as soon as the stream leaves the nozzle exit. Thus the typical digging function is performed by placing and keeping the nozzle exit, as close as possible, to the ground being excavated. This, of course, also keeps the nozzle exterior as close as possible to any high velocity back flow or blow back. When this back flow contains particles of sufficient hardness to erode any typical metal, such as stainless steel, anodized aluminum, brass etc., it is a matter of relatively brief time (e.g., days or weeks) to nozzle failure.
[0015] Experience shows that materials as hard as ordinary sand are very effective in eroding metals. Consequently this effect may also be termed as “reverse sand blasting”. The inventors of this application have experienced that this effect is seen at its worst when working in sand, in places such as middle eastern desserts. However the effect is perceptible in any soil that has sufficient content of such hard particles. Thus the occurrence and extent of the problem is difficult to predict. For, example the inventors of this application have also experienced this reverse sandblasting nozzle failure effect when working with air excavation tools in areas such as Ohio, many miles from the nearest large body of water, where one might ordinarily expect sandy beaches. Many geologic conditions can lead to soils containing small hard particles, similar to sand. An example is long term wind or water erosion of rock. It is believed that any hard particles in the soil will increase the reverse sand blasting effect on the nozzle.
[0016] Typical supersonic nozzle designs, as evidenced in the above cited patents usually focus on the interior of the nozzle design, in part because of the difficulty of these designs, and their tendency to be sophisticated, and the exterior has been left to the casual discretion of the designer. In some cases, the exterior design has been the subject of design patent protection, see for example U.S. Design Pat. No. D408,830, while there has been a functional need for a more utilitarian approach to nozzle exterior construction lurking in the soil.
[0017] FIG. 1 is a reproduction of an isometric figure from issued U.S. Design Pat. No. D408,830 and is an accurate representation of a commercially available air excavation nozzle that has been used for many years as the exterior of a supersonic nozzle used in excavation. This nozzle design is emblematic of the undesirable characteristics that the present invention solves. The integral nozzle tip outside diameter is smaller then the body of the nozzle, which exposes that nozzle body to reverse sand blasting erosion. This resulting nozzle body flat presents a perfect reverse sand blasting target. A similar perfect target is presented at the exterior end of the wrench flats that precede the trailing balance of the nozzle body. Further, the rear end of this nozzle is blunt, thereby presenting a likely snagging surface as the nozzle is withdrawn from soil.
[0018] FIGS. 2A and 2B illustrate a commercially available prior art supersonic pneumatic nozzle that was put in service with out any of the protective features of the present invention. The nozzle was used in shallow trenching in sandy soil. The nozzle tip was integral with the nozzle body. The extent of the actual reverse sand blasting erosion to the wear tip and the nozzle is illustrated by tightly spaced shading. This erosion was sufficiently severe within a month to carry the erosion through the nozzle exterior into the nozzle interior, near the nozzle entrance, as shown. In other words, nozzle failure occurred within a month of active service in a sandy environment.
[0019] It is an object of the present invention to provide a supersonic air excavation nozzle that alleviates at least some of the above stated problems associated with reverse sand blasting.
SUMMARY OF THE INVENTION
[0020] The above object is achieved with the embodiments according to this invention, which include is a supersonic pneumatic nozzle assembly with a wear tip formed of an especially hard, erosion resistant material. The erosion or wear resistant material may be carbide material such as Cerbide™ material (a polycrystalline tungsten carbide), any cemented carbide, or carbide(s), of boron, titanium, tungsten or other highly wear resistant formulations. The nozzle body and the wear tip of the nozzle assembly are both generally cylindrical in exterior shape, and where an outside diameter of the wear tip is (1) approximately equal to or larger than any external diameter of the nozzle body, or otherwise shadows all of the nozzle body exterior; or (2) includes a leading edge deflecting surface to deflect “reverse sandblasted particles” away from the nozzle body, or (3) both. When such a nozzle assembly is used for excavation, the purpose of this structure is to resist the action of high velocity air, rebounding from the ground with entrained hard particles that can erode the nozzle body exterior, thus leading to nozzle assembly failure.
[0021] One aspect of the invention can be described as providing a pneumatic nozzle assembly comprising a nozzle body having an internal through passage with inlet on the a first side and an outlet on an opposed side of the nozzle body; and a replaceable cylindrical wear tip removably coupled to the nozzle body and with an internal through passage aligning with the outlet of the nozzle body, and wherein an outside form of the wear tip is configured to direct reverse sand blasting particles away from the external surfaces of the nozzle body.
[0022] The invention may provide that the nozzle body is a converging-diverging cylindrical nozzle body having the inlet on the converging side and the outlet on the diverging side of the nozzle body; and wherein an outside diameter of the wear tip is greater than or equal to any external diameter of the nozzle body to direct reverse sand blasting particles away from the external surfaces of the nozzle body. The outside diameter of the wear tip may, in one embodiment, be greater than the external diameter of the nozzle body along a first section of the wear tip beginning at the end of the wear tip opposed from the nozzle body, and with the wear tip further including a smooth transitional shape from a widest part of the wear tip to a distal end of the nozzle body to minimize snagging of the nozzle assembly on buried objects in use.
[0023] The invention may provide that the internal through passage of the wear tip aligning with the outlet of the nozzle body has a diameter substantially equal to or larger than the outlet at a position adjacent the outlet. Further the invention may provide that the interior of the wear tip, closest to the nozzle body outlet, is sufficiently close to the physical inside diameter of the nozzle body outlet, whereby any rebounding air stream carrying hard particles from the ground being excavated is readily drawn into the exiting supersonic jet and ejected. The invention may provide that the internal through passage of the wear tip aligning with the outlet of the nozzle body has diverging shape such that any rebounding air stream carrying hard particles in that region from the ground being excavated is directed towards the exiting air jet.
[0024] The invention may provide an intermediate adaptor attached to the nozzle body to facilitate removable attachment to the nozzle body.
[0025] The invention may provide that the nozzle body is a converging-diverging cylindrical nozzle body having the inlet on the converging side and the outlet on the diverging side of the nozzle body; wherein a largest outside diameter of the wear tip is less than the external diameter of the nozzle body, wherein the wear tip includes a leading end of the wear tip beginning opposite of the nozzle body which is outwardly tapered from the distal end of the wear tip toward the nozzle body to direct reverse sand blasting particles away from the external surfaces of the nozzle body.
[0026] Another aspect of the invention provides a method of soil excavation comprising the steps of: providing a pneumatic nozzle assembly comprising a converging-diverging nozzle body having an internal through passage with inlet on the converging side and an outlet on the diverging side of the nozzle body, and a wear tip removably coupled to the nozzle body and with an internal through passage aligning with the outlet of the nozzle body; and directing reverse sand blasting particles away from the external surfaces of the nozzle body through the use of the wear tip. The invention may provide the step of providing supersonic flow from the pneumatic nozzle.
[0027] The method of soil excavation of claim 18 wherein an outside diameter of the wear tip is greater than or equal to any external diameter of the nozzle body to direct reverse sand blasting particles away from the external surfaces of the nozzle body.
[0028] An alternate embodiment of the present invention is similar, but uses any typical metal for either or both the pneumatic nozzle body and the wear tip, with provision of a wear tip outside diameter that exceeds any outside diameter of the nozzle body to provide sacrificial and temporarily protective material for the nozzle body, plus a suitable wear tip forward extension.
[0029] These and other advantages of the present invention will be clarified in the description of the preferred embodiments taken together with the attached drawings in which like reference numerals represent like elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Other objects and advantages appear in the following description and claims. The enclosed drawings illustrate some practical embodiments of the present invention, without intending to limit the scope of the invention or the included claims.
[0031] FIG. 1 is a perspective view of a prior art soil excavating supersonic pneumatic nozzle assembly;
[0032] FIG. 2A is a section elevation side view of a prior art soil excavating supersonic pneumatic nozzle assembly;
[0033] FIG. 2B is a cross-sectional view of the prior art nozzle assembly of FIG. 2A taken along line 2 B- 2 B of FIG. 2A and wherein section line 2 A- 2 A illustrates the section line for FIG. 2A ;
[0034] FIG. 3A is a section elevation side view of a soil excavating supersonic pneumatic nozzle body and wear tip according to one embodiment of the present invention;
[0035] FIG. 3B is a cross-sectional view of the nozzle of FIG. 3A , wherein line 3 A- 3 A illustrates the section line for FIG. 3A ;
[0036] FIG. 4A is a section elevation side view of a soil excavating supersonic pneumatic nozzle body and wear tip according to another embodiment of the present invention;
[0037] FIG. 4B is a top end view of the nozzle body of FIG. 4A , wherein line 4 A- 4 A illustrates the section line for FIG. 4A ;
[0038] FIG. 4C is an exploded section elevation side view of the nozzle body and wear tip of FIG. 4A ;
[0039] FIG. 5A is a section elevation side view of a soil excavating supersonic pneumatic nozzle body and wear tip according to another embodiment of the present invention; and
[0040] FIG. 5B is a top end view of the nozzle body of FIG. 5A , wherein line 5 A- 5 A illustrates the section line for FIG. 5A .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] FIG. 1 is a view of a prior art nozzle assembly of the prior art as shown in Design patent D408,830 and is representative of a commercially available nozzle design. This prior art figure also illustrates most of the failures with use existing pneumatic nozzle assembly designs for supersonic soil excavations that are addressed by this invention. The prior art nozzle exit 15 of this prior art nozzle assembly design is so close to the integral wear tip leading surface 16 , that this prior art wear tip leading surface 16 , will be worn away, much more rapidly than either the metal wear tip 2 or the replaceable hard wear tip 28 of the present invention, described below. More significantly, the prior art leading outside diameter 17 , is smaller than either the prior art nozzle body shoulder 18 or the prior art wrench flat shoulder 19 of the nozzle body, making both surfaces 18 and 19 , reverse sand blasting targets. This exterior type, of a generally smaller diameter forward and larger diameter rearward is typical of existing nozzle assemblies, supersonic or otherwise. In most applications the nozzles are not supersonic nozzles, such as in cleaning applications or injection applications, and in such applications the nozzles do not encounter significant reverse sand blasting effects because they produce air jets of much smaller exit velocity and/or are not used for excavating purposes.
[0042] FIGS. 2A and 2B illustrate an example of another prior art failed supersonic soil excavating pneumatic nozzle construction. This nozzle assembly design has similar nozzle entrance 3 , nozzle throat 4 , and nozzle expansion exit 5 construction as found in the present invention as described below, however, the external construction of this prior art nozzle body results in premature failure in some soil excavation applications. The design of this nozzle assembly has an integral metal “wear tip” 2 formed of the same metallic material as the body of the nozzle. The metal wear tip 2 does not shadow the balance of the nozzle design, thus both the wear tip eroded material 21 and the nozzle eroded material 22 suffer significantly in a very short time (less than a month) sufficient to cause nozzle failure by erosion, at the erosion into nozzle interior 25 . Also, the wrench flats 8 are so far forward that they open a reverse sand blasting target.
[0043] FIG. 3A is a cross section of one embodiment of a supersonic air nozzle assembly according to one embodiment of the invention, which is a supersonic nozzle body 1 , with a removable wear tip 2 of metal, where the wear tip outside diameter 10 is generally larger that the outside diameter 9 of the nozzle body 1 , thus protecting the nozzle body 1 from reverse sand blasting. Also, the interior 27 of the forward wear tip 2 , is sloped or otherwise contoured to direct any nearby reverse sand blasting materials to be conveyed to the side of the exiting jet so as to protect the nozzle exit 5 from this effect. Also, each anterior transition such as 11 , 12 of the nozzle assembly exterior shape is sloped gently relative to the nozzle axis so as to avoid snagging of any of these surfaces on tree roots or other buried objects when the nozzle assembly is being extracted from the soil. FIG. 3B is an end view of FIG. 3A and illustrates it's generally round shape.
[0044] FIG. 4A is the cross section of an assembled alternative embodiment of the invention, that uses the very hard wear tip 2 material such as Cerbide™ material, etc. constructed as a removable wear tip, where the outside diameter of the wear tip 10 is equal to or somewhat larger in diameter than the diameter 9 of the nozzle body 1 . FIG. 4C is the same embodiment as FIG. 4A , but illustrates each of separate parts, before assembly.
[0045] FIGS. 3A and B, 4 A and B and 5 A and B illustrate three preferred embodiments of a supersonic nozzle assembly having a nozzle body 1 with a wear tip 2 that is used for excavating soil.
[0046] Typically, a supersonic nozzle assembly includes a nozzle body 1 which will have a nozzle entrance 3 , a constricting nozzle throat 4 operating at sonic flow, a nozzle expansion exit 5 that causes air flow to exit at supersonic speed. In FIG. 3A , the metal wear tip 2 is constructed of any one of several metals that are commonly used to construct nozzles (stainless steel, etc.). The metal wear tip outside diameter 10 is larger than the nozzle body outside diameter 9 , both of which are generally cylindrical. This provides a protective and sacrificial material to absorb the reverse sand blasting erosion that occurs when excavating in sandy soils or soils containing significant quantities of small, hard particles, typically the size of sand, that in time, will erode any exposed, forward facing nozzle surface.
[0047] This metal wear tip 2 , also has a generous metal wear tip extension 37 for the same purpose. If the metal wear tip outside diameter 10 were to be smaller that the nozzle body outside diameter 9 , the reverse sand blasting will immediately wear the outside of the wear tip 2 and, more or less simultaneously, the external shape of the nozzle body, as well, as in prior art structures. In surprisingly short time periods (weeks), this can lead to nozzle failure as the nozzle body is worn through to the interior. Conventional supersonic nozzle assemblies in use have leading exterior diameters 17 , see FIG. 1 , that are smaller in diameter than the trailing nozzle body outside diameter 9 , so in the many operating conditions, they wear out quickly.
[0048] A similar issue occurs near the nozzle expansion exit 5 . This invention places a forward, inclined or curved wear tip inside surface corner 26 sufficiently close to the nozzle expansion exit 5 , that any reflected hard particles entrained in reflected air in that region are directed closely towards the exiting air stream, so that those particles are inducted into exiting supersonic air stream and directed away from the nozzle. Also, the inside wear tip entrance corner 27 , is placed at an inclined radial location relative to the wear tip inside surface corner 26 , in a smoothly inclined relationship, so that reverse sand blasting particles in this region of the tip 2 are directed towards the wear tip inside surface corner 26 , thence inducted into that air stream and directed away from the nozzle assembly.
[0049] Similarly, any nozzle trailing external surface must be shadowed by the metal wear tip 2 , and ideally also by any leading nozzle exterior features. This requires that any wrench flats 8 must be near the rear of the nozzle exterior. Another requirement for the exterior nozzle body 1 and metal wear tip 2 surfaces is they must be connected to the next exterior shape in turn by a taper or other similar shape that has a shallow inclination to the central axis of the nozzle such as the wear tip reverse angle 11 , the wrench flat reverse angle 12 and the nozzle end reverse angle 13 so that when the nozzle assembly is being withdrawn from the soil, it will not snag on roots or other buried objects. There needs to be a nozzle to barrel connection 7 , so as to receive an air supply of suitable pressure and quantity of flow in a conventional fashion.
[0050] FIG. 4A is an assembled, optional embodiment of the nozzle assembly according to the present invention. It has the same or similar nozzle entrance 3 , nozzle throat 4 , and nozzle expansion exit 5 of FIG. 3A of a supersonic nozzle. It also has the external nozzle features of the nozzle in FIG. 3A , including the same nozzle outside diameter 9 , wrench flats 8 with a wrench flat reverse angle 12 , and nozzle end reverse angle 13 . The nozzle assembly employs a replaceable hard wear tip 28 , whose wear tip outside diameter 10 , is the same as or somewhat larger than the nozzle outside diameter 9 , and where the material of the replaceable hard wear tip 28 is any of a Cerbide™ material, any cemented carbide, or carbide(s), of boron, titanium, tungsten or other extremely hard and highly wear resistant material or combination.
[0051] Similar to the embodiment of FIG. 3 , this embodiment of FIG. 4A also places an inclined or curved wear tip inside surface corner 26 that is placed sufficiently close to the nozzle expansion exit 5 , that any reflected hard particles entrained in reflected air in that region are directed closely towards the exiting air stream, so that those particles are inducted into that air stream and directed away from the nozzle assembly. Also, the inside wear tip entrance corner 27 , is placed at an inclined radial location relative to the wear tip 28 inside surface corner 26 , in a smoothly inclined relationship, so that reverse sand blasting particles in this region are directed towards the wear tip inside surface corner 26 , thence inducted into the supersonic air stream exiting the nozzle assembly, and directed away from the nozzle assembly.
[0052] The hard material of the tip 28 resists conventional machining, shapes, such as the one shown, can be formed by hot pressing into a mold and by similar methods. Thus small threads are difficult to form. For this and other reasons of convenience, a metallic wear tip insert 29 , containing a threaded wear tip to nozzle connection 6 , is pressed into the molded, replaceable hard wear tip 28 , so it may be readily attached to a supersonic nozzle 1 , previously machined from metal.
[0053] FIG. 4C is an exploded view of the assembled optional preferred embodiment of FIG. 4A , for clarity and to indicate the assembly process, as follows. The machined wear tip insert 29 , is pressed into replaceable hard wear tip 28 , such that the wear tip insert press fit 31 (i.e. the outer diameter surface), has a small interference fit with the wear tip press fit 30 (i.e. the inner diameter surface). The two parts are pressed together until the wear tip alignment surface 32 , aligns against the wear tip insert alignment surface 33 .
[0054] FIG. 5A is an assembled, optional embodiment of the nozzle assembly of the invention. It has all of the features of FIG. 4A , except that it employs a replaceable hard wear tip 28 , whose wear tip outside diameter 10 , is smaller than the nozzle outside diameter 9 , and where the material of the replaceable hard wear tip 28 is any of a Cerbide™ material, any cemented carbide, or carbide(s), of boron, titanium, tungsten or other extremely hard and highly wear resistant material or combination. Further, this hard wear tip 28 has an inclined or other shaped leading edge 38 , that directs a reverse sand blasting first portion 34 , around the wear tip 28 , and into a reverse sand blasting second portion 35 , that would otherwise erode the “exposed” portion of the nozzle exterior, thus redirecting the combined flow 36 , away from the exterior of the nozzle body 1 .
[0055] In short the present invention provides a tool suitable for soil excavation that can be used in a number of distinct applications, wherein the tool includes a sonic or supersonic pneumatic nozzle body 1 with a wear tip 2 or 28 , preferably replaceable, each part constructed of a typical nozzle material such as stainless steel, brass, aluminum, etc., where the nozzle in combination with it's wear tip, are both generally uniformly cylindrical in exterior shape, and whose wear tip outside diameter(s) is larger than any external diameter of the nozzle body.
[0056] Although the present invention has been described with particularity herein, the scope of the present invention is not limited to the specific embodiment disclosed. It will be apparent to those of ordinary skill in the art that various modifications may be made to the present invention without departing from the spirit and scope thereof. The scope of the invention is not to be limited by the illustrative examples described above. The scope of the present invention is defined by the appended claims and equivalents thereto. | A tool suitable for soil excavation that can be used in a number of distinct applications is disclosed, wherein the tool includes a sonic or supersonic pneumatic nozzle assembly comprising a converging-diverging cylindrical nozzle body having an internal through passage with inlet on the converging side and an outlet on the diverging side of the nozzle body; and a replaceable cylindrical wear tip removably coupled to the nozzle body and with an internal through passage aligning with the outlet of the nozzle body, and wherein an outside form of the wear tip is configured to direct reverse sand blasting particles away from the external surfaces of the nozzle body. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to dental film chip hangers and more particularly to a bouyant hanger unit for a dental film chip.
In order to reduce the cost of the equipment needed by a dentist to develop dental film chips that he has used to X-ray the mouth of a patient, the present practice is to provide a long metal hanger provided with transversely extending clips spaced along either side of the length thereof. Each clip is capable of holding a dental film chip. The metal hanger is hung by its hooked upper end above a tank of solution with the film chips immersed therein and is then manually transferred by its hooked upper end to successive tanks of solutions as needed to process the film chips.
Such a hanger unit because of its length is not only cumbersome to handle but requires deep tanks of solutions in which to immerse the dental film chips. Moreover, because of the depth of the solution required in the developer tank, the concentration of the chemicals making up the solution tends to vary at the different levels thereof with the result that the film chips held on the lower end portion of the hanger may develop differently than those held on the upper end thereof.
SUMMARY OF THE INVENTION
In accordance with the present invention a hanger unit for a dental film chip is molded of plastic to comprise a long, relatively thin rectangular body with a clip on the bottom end thereof. The body has a circular projection with a smaller diameter base molded on the front face thereof just below the upper end portion thereof and a circular recess with an enlarged diameter bottom molded on the back face thereof. The centers of the circular projection and the circular recess lie on the same axis. The body further has a circular hole through the central portion thereof which is provided with a circular projecting rim on the front face thereof and a circular peripheral recess on the back face thereof. The back face of the body is molded with the upper end portion thereof including the upper wall portion of the circular recess removed, leaving inwardly chamfered shoulders on either side of the circular recess. The remaining thin wall on the upper portion of the front face of the body forms the handle for the hanger unit. A longitudinal slot extends down through the middle of the upper half of the body including the handle portion, the circular projection, and on down to the circular hole.
To assemble a pair of hanger units, the circular projection on the front face of a first hanger unit is positioned against the chamfered shoulders on either side of the circular recess on the back face of a second hanger unit. Then, upon moving the hanger units longitudinally toward each other, the sides of the enlarged diameter bottom of the circular recess on the second hanger unit snap over the sides of the circular projection on the first hanger unit. When so positioned, the circular peripheral recess on the central portion of the back face of the second hanger unit is able to seat against the projecting circular rim on the central portion of the front face of the first hanger unit such that the two hanger units are assembled face-to-face.
Such a construction enables any number of hanger units with film chips on the bottom clips thereof to be assembled together face-to face and, when the assembly is placed in a solution, it floats in an upright position with the handle portions on the upper ends thereof extending above the surface of the solution. Note that any of the hanger units in the assembly can have its central circular peripheral rim and circular peripheral recess on the opposite faces thereof freed of the hanger units on either side thereof such that it can be pivoted on its upper circular projection and circular recess away from the remaining hanger units in the assembly for the purpose of enabling the dental film chip held by the clip on the bottom end thereof to be examined.
Accordingly, one of the objects of the present invention is to provide a low-cost plastic hanger unit having a clip on the bottom end thereof for use in bouyantly suspending a dental film chip in a processing solution with the upper end portion of the hanger unit extending above the surface of the solution.
Another object of the present invention is to provide a bouyant hanger unit having a clip on the bottom end thereof for holding a dental film chip wherein the hanger unit is adapted to be readily joined face-to-face with other similar hanger units to provide a multiple dental film chip hanger assembly that will float in a processing solution.
Still another object of the present invention is to provide a plastic hanger unit having a clip on the bottom end thereof for holding a dental film chip wherein the hanger unit is adapted to be readily joined face-to-face by means of a pivotal connection with other similar hanger units to provide an assembly and wherein any one of the hanger units can be pivotally swung on its connection away from the remaining hanger units in the assembly to enable the dental film chip on the bottom end thereof to be examined.
With these and other objects in view the invention consists of the construction, arrangement and combination of the various parts of the device whereby the objects contemplated are obtained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational perspective view showing the front face of the dental film chip hanger unit in accordance with the present invention;
FIG. 2 is an elevational perspective view showing the back face of the hanger unit in FIG. 1;
FIG. 3 is a vertical sectional view of a first hanger unit as taken on line 3--3 of FIG. 1 and illustrating by dashed lines how a second hanger unit can be positioned relative to the first hanger unit prior to the two hanger units being snapped together;
FIG. 4 is a vertical sectional view showing the pair of hanger units in FIG. 3 after they have been assembled together;
FIG. 5 is a vertical sectional view as taken along line 5--5 of FIG. 4;
FIG. 6 is a cross sectional view as taken along line 6--6 of FIG. 4;
FIG. 7 is an elevational perspective view of a hanger unit with a dental film chip held on the bottom clip thereof;
FIG. 8 is an elevational perspective view of an assembly of hanger units with dental film chips held on the bottom clips thereof;
FIG. 9 illustrates a processing tank having three compartments of solutions in which hanger units with dental film chips on the bottom clips thereof are floating;
FIG. 10 is an elevational view of one of the compartments of the processing tank as taken on line 10--10 of FIG. 9 showing hanger units with dental film chips on the bottom clips thereof floating in the solution thereof;
FIG. 11 is an elevational perspective view of an assembly of hanger units having dental film chips on the bottom clips thereof and showing one of the hanger units having been pivoted away from the others so that the dental film chip on the bottom clip thereof can be examined;
FIG. 12 is a perspective view showing how an assembly of hanger units having dental film chips on the bottom clips thereof can be mounted on its sides for drying the film chips; and
FIG. 13 is a perspective view showing how a hanger unit with a dental film chip held by the clip thereon can be mounted with the longitudinal slot on the handle end portion thereof fitted over the upper end of a vertical wall for drying the film chip.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will first be made to FIGS. 1 and 2 showing a perspective view of a hanger unit 10 in accordance with the present invention. The hanger unit 10 is molded of plastic to include an elongated generally rectangular body 12 having a front face 14 and a back face 15. A clip 23 is provided on the bottom of the body 12. The clip 23 includes a thin tab 19 depending from the center of the front face 14 thereof and a thin tab 21 extending from each side of the back face 15 thereof. The internal surface of the center tab 19 is provided with an angular transverse stop 17 (FIG. 3) having a narrow end surface 18 and the internal surface of each of the spaced side tabs 21 is provided with a small protuberance 22. The small protuberances 22 on side tabs 21 and the opposing narrow end surface 18 on the central tab 19 may lie in slightly overlapping planes.
Molded on the front face 14 of the body 12 just below the upper portion thereof is a circular projection 28 provided with a smaller diameter circular base 29 and molded on the upper portion of the back face 15 so as to lie on the same axis with circular projection 28 is a circular recess 33 provided with an enlarged diameter bottom 36. The circular projection 28 on the front face 14 has the same outer diameter and cross section as the enlarged diameter bottom 36 of the circular recess 33 on the back face 15 of the body 12. The circular recess 33 is formed with an internal wall 34 which slants radially outwardly from the mouth to the enlarged diameter bottom 36 of the circular recess 33 and has a depth equal to the height of the circular projection 28.
The body 12 is molded with the upper end portion of its back face 15 and including the upper wall portion of the circular recess 33 thereon removed, leaving inwardly chamfered shoulders 38 on either side of the circular recess 33. The thin wall left on the upper end portion of the front face 14 of the body 12 forms a handle portion 25. The body 12 further has a circular hole 27 through the central portion thereof with a circular projecting rim 32 molded thereabout on the front face 14 thereof and with a circular peripheral recess 37 molded thereabout on the back face 15 thereof.
The peripheral circular recess 37 has the same outer diameter and cross section as the projecting circular rim 32 on the opposite face thereof. A longitudinal slot 26 extends down through the middle of the upper half of the body 12 including the handle portion 25, the circular projection 28, and on down to the circular hole 27.
As shown, the front face 14 of body 12 may be molded with a grooved recess 31a on either side of the longitudinal slot 26 intermediate the circular projection 28 and the circular hole 27 and may be molded with a generally rectangular recess 31a extending from just below the circular hole 27 to the bottom of the body 12. Likewise, the back face 15 may be molded with a grooved recess 30b on either side of the elongated slot 26 opposite the grooved recesses 30a on the front face 14 and with a generally rectangular recess 31b opposite the recess 31a on the front face 14. The purpose of the grooved recesses 30a and 30b and the rectangular recesses 31a and 31b is to lighten and distribute the weight of the plastic body 12 to assure that the hanger unit 10 will float with its upper handle portion 25 extending out of the solution when a film chip 39 is held by the clip 23 on the bottom end thereof.
Reference will next be made to FIG. 3 which shows in solid lines a vertical sectional view of a first hanger unit 10 as taken along line 3--3 of FIG. 1. Shown in section by dotted lines is a second identical hanger unit 10' bearing reference designations for the parts thereof which are primed to distinguish them from the corresponding parts of the front hanger unit 10.
As shown, the second hanger unit 10' is positioned with its chamfered shoulders 38' on the back face 15' thereof respectively positioned beneath the sides of the circular projection 28 on the front face 14 of the first hanger unit 10. When so positioned, the plane of the second hanger unit 10' lies at a slight angle with respect to the plane of the first hanger unit 10, as shown, because of the circular projecting rim 32 provided on the front face 14 of the latter. The second hanger unit 10' is then pushed upwardly, as indicated by arrow 35, such that the sides of circular recess 33' thereon respectively slip over the sides of the circular projection 28 such that the latter is seated in the enlarged diameter circular bottom 36' of the circular recess 33'.
It should now be appreciated that the longitudinal slot 26 on body 12 of the first hanger unit 10 permits the upper side portions of the body 12 to bend inwardly toward each other. Likewise, the longitudinal slot 26' on the body 12' of the second hanger unit 10' permits the upper side portions of the body 12' to bend away from each other. Thus, the longitudinal slots on the bodies of the hanger units facilitate the fitting of the sides of circular projection 28 provided on the first hanger unit 10 within the sides of the circular recess 33' provided on the second hanger unit 10'.
In any event, once so seated, the peripheral circular recess 37' provided on the back face 15' of the second hanger unit 10' fits over the circular projecting rim 32 on the front face 14 of the first hanger unit 10 such that the back face 15' of second hanger unit 10' is now held in position flush against the front face 14 of the first hanger unit 10, as shown in FIG. 4.
Reference will next be made to FIG. 5 which is a vertical sectional view taken on line 5--5 of FIG. 4 together with FIG. 6 which is a transverse cross sectional view as taken on line 6--6 of FIG. 4. Thus, these Figures show how the enlarged circular projection 28 provided on the front face 14 of the first hanger unit 10 is fitted to seat into the enlarged circular bottom 36' of the circular recess 33' provided on the face 15' of the second hanger unit 10' so as to effectively provide a pivotal connection between the two hanger units 10 and 10'.
Reference will next be made to FIG. 7 which illustrates a hanger unit 10 having a dental film chip 39 held by the clip 23 on the bottom end thereof and to FIG. 8 which illustrates how a plurality of hanger units 10 each having a film chip 39 clipped on the bottom end thereof can be held together, as above described, to form an assembly 44.
FIG. 9 illustrates a processing tank 40 having either individual hanger units 10 or an assembly 44 of hanger units 10 floating in the solutions provided in the compartments 41, 42 and 43 thereof. As shown, the hanger units 10 float with their handle portions 25 extending out of the upper surface of the solutions thereof. As illustrated in FIG. 10, the film chips 39 are bouyantly supported at the same depth in the solution of a compartment and each compartment need be only deep enough to bouyantly accomodate the hanger unit 10 with the film chip 39 depending from the bottom clip 23 thereon. Color coding, for example, may be used to distinguish the hanger units 10 being used to hold the dental film chips for a particular patient.
FIG. 11 shows how any selected one of the hanger units 10 in the assembly 44 can be pivoted on its circular projection 28 provided on the front face 14 thereof and its circular recess 33 provided on the back face 15 thereof away from the other hanger units 10 of the assembly 44 for the purpose of examining the dental film chip 39 held on the bottom thereof. It should be noted that the radially outwardly slanting internal wall 34 on the circular recess 33 of a hanger unit operates to retain the circular projection 28 on the next hanger unit 10 in the circular recess 33 as the central portions of the hanger units in the assembly are separated to free a hanger unit so that it can be pivoted outwardly from the others in the assembly.
FIG. 12 illustrates how an assembly of two or more hanger units 10 with film chips 39 held by the clips 23 thereof can be placed on its side to enable the film chips 39 to dry. FIG. 13 shows how a hanger unit 10 can be positioned with the longitudinal slot 16 in its body 12 fitted over the upper end of a wall 46 for the purpose of drying the film chip 39 held on the end thereof.
While the description has been concerned with a particular structural embodiment of the present invention, it is to be understood that many modifications and variations in the construction and arrangement thereof may be provided for without departing from the spirit and scope of the invention or sacrificing any of its advantages and the invention is, therefore, to be limited only as indicated by the scope of the appended claims. | A bouyant hanger unit comprises an elongated body molded of plastic to provide a clip on the bottom end thereof for holding a dental film chip in the plane of the hanger unit. The hanger unit has a circular projection on one face thereof axially aligned with a circular recess on the opposite face thereof. Such a construction enables a plurality of hanger units to be assembled face-to-face while permitting any of the hanger units to be pivoted away from the remaining hanger units in the assembly for the purpose of examining the dental film chip clipped on the bottom thereof. When the individual hanger units or an assembly of the hanger units with dental film chips clipped on the bottom thereof are placed in a solution they float in an upright position with the upper end thereof extending above the surface of the solution. | 8 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to an electromagnetic wet clutch system.
[0002] A conventional coupling includes a rotary casing, an inner shaft, a primary clutch, a ball cam, a pressure plate, a cam ring, a pilot clutch, an armature, and an electromagnet.
[0003] The pilot clutch includes a multi-plate clutch of inner and outer plates. The multi-plate clutch is formed with lubrication grooves or is nitrided under a gas atmosphere or a salt-bath thereon. Neighboring inner and outer plates have air gaps of lubrication grooves or surface treatment layers (nitrided film) therebetween.
SUMMARY OF THE INVENTION
[0004] The air gaps or layers, however, interfere or reduce the magnetic force of the electromagnet, thus deteriorating magnetic flux efficiency. The deterioration lowers the force of attraction to the armature.
[0005] Specifically, both sides of the inner and outer plates are formed with the lubrication grooves or a surface treatment layers. Between an outer plate and the armature or the rotor, the air gaps of lubrication grooves or surface treatment layers cause loss of magnetic flux. This loss deteriorates magnetic flux efficiency.
[0006] The present invention is directed to an electromagnetic wet clutch system with improved clutch plates durability.
[0007] The present invention is directed to one with improved magnetic flux efficiency.
[0008] The invention includes an electromagnetic wet clutch system. The system includes operation members configured to magnetically work. The system includes a set of clutch plates configured to engage by the operation members. The set of clutch plates includes first plates with first sides. Respective one of the first sides is configured to contact respective one of the operation members. At least one of the first sides is boundary-lubricative.
[0009] According to the system, an operation member with a stable sectional area of magnetic path contacts a boundary-lubricative first side with air gaps for boundary-lubrication. This allows maximum magnetic permeability, thus further improving magnetic flux efficiency.
[0010] The term of “boundary lubricative” means that a side includes minute projections and recesses, surface roughness and a basic roughness remaining due to the formation into a plate shape by pressing. The projections and recesses are not limited by a rotational and a radial direction, a dotted state and length. The term means that a surface structure of the side is essentially boundary lubricative.
[0011] The operation members include, for example, an armature and a rotor.
[0012] Preferably, the set of clutch plates comprises a second plate disposed between the first plates. The second plate including inner and outer peripheries defines a second side therebetween. The second side defines a hydraulic passage extends between the inner and outer peripheries. According to the system, the hydraulic passage on the second side allows secure lubrication and cooling, thus preventing wearing and seizing.
[0013] Preferably, the second plate includes a boundary-lubricative second opposite side relative to the second side. According to the system, the combination of first and second plates improves magnetic flux efficiency, which increases engagement torque of the system.
[0014] Preferably, the second plate includes a second opposite side relative to the second side, the second opposite side defining a hydraulic passage.
[0015] Preferably, the hydraulic passage extends radially. This system enhances the hydraulic circulation on the second side, thus further improving cooling exertion. The preference allows the hydraulic fluid to be retained quickly and uniformly on a boundary-lubricative first side.
[0016] Preferably, a boundary-lubricative first plate is configured to rotate integrally with an operation member. This system further prevents variation of air gaps and increases the magnetic path in the surface area, thus improving magnetic flux efficiency. The first side or a contact side requires no hardening treatment such as a heat treatment, thus allowing improvement in magnetic flux efficiency and reduction in fuel costs.
[0017] Preferably, the first plate and the operation member connect to a common spline.
[0018] Preferably, the set of clutch plates includes a pair of sides sliding each other. One of said pair of sides includes a hydraulic passage. Another of said pair of sides is boundary-lubricative. According to the preference, the loss of magnetic permeability due to the hydraulic passage on the one side allows the loss of magnetic force to be limited to a minimum.
[0019] Preferably, the set of clutch plates is disposed between inner and outer rotary members. The inner and outer rotary members have a fluid sealed therebetween for lubricating the set of clutch plates. According to the system, within a limited space between the inner and outer rotary members, the lubrication, cooling and magnetic flux efficiency of the system improve. The system has large torque capacity of clutch engagement, with less variation per time and excellent durability.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0020] These and other features, aspects, and advantage of the present invention will become better under stood with reference to the following description, appended claims, and accompanying drawings where:
[0021] [0021]FIG. 1 is a sectional view of a coupling according to the first embodiment of the invention;
[0022] [0022]FIG. 2 is an enlarged sectional view of a pilot multi-plate clutch in FIG. 1;
[0023] [0023]FIG. 3 is a perspective view of inner and outer plates in FIG. 1;
[0024] [0024]FIG. 4 is a perspective view of inner and outer plates according to the second embodiment;
[0025] [0025]FIG. 5 is a perspective view of inner and outer plates according to the third embodiment;
[0026] [0026]FIG. 6 is an exploded sectional view of a multi-plate clutch according to the fourth embodiment;
[0027] [0027]FIG. 7 is a perspective view of inner and outer plates of the multi-plate clutch in FIG. 6; and
[0028] [0028]FIG. 8 is a perspective view of inner and outer plates of the multi-plate clutch according to the fifth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The embodiments of the invention will be described with reference to drawings.
[0030] [First Embodiment]
[0031] As shown in FIG. 1, coupling 1 is disposed between a rear differential to be separated and an engine (transfer). The left of FIG. 1 corresponds to the front (engine) of a vehicle.
[0032] Whole coupling 1 is housed in a casing (not shown in FIGS.) fixed to the vehicle body. Coupling 1 includes clutch housing 3 or an outer rotary member. Coupling 1 includes clutch hub 9 or an inner rotary member in clutch housing 3 . Disposed between clutch housing 3 and clutch hub 9 are primary clutch 11 , ball cam 13 , pressing member 15 , cam ring 17 , and pilot clutch 19 .
[0033] Clutch housing 3 of a magnetic steel is configured in a cylindrical shape as a whole. The front part of the housing connects to power transmission shaft 5 . The rear part of the housing has opening 21 provided thereto.
[0034] Shaft 5 is made of a magnetic steel for a shaft. The external face 5 a of the shaft is formed with serration 7 for serration connection with a companion flange (not shown in FIGS.). The companion flange connects to a flange of a propeller shaft to connect to the engine (transfer).
[0035] Mounted to opening 21 is ring-shaped magnetic rotor 31 to rotate integrally with housing 3 . Shaft 5 , housing 3 and rotor 31 are integral with each other. They 5 , 3 , 31 are supported to a casing of a vehicle by bearings (not shown) on shaft 5 and rotor 31 .
[0036] Clutch hub 9 is disposed within housing 3 . The front end thereof is supported to housing 3 by ball bearing 43 . Hub 9 connects to a drive pinion shaft of the rear differential.
[0037] Multi-plate primary clutch 11 is disposed between housing 3 and hub 9 . Ball cam 13 is disposed between pressing member 15 and cam ring 17 . Ball cam 13 and cam ring 17 constitute a cam mechanism.
[0038] Pressing member 15 is splined axially movably to hub 9 . Ball cam 13 presses primary clutch 11 to be engaged under a thrust force.
[0039] Cam ring 17 is disposed on the outer peripheral face of hub 9 . Disposed between cam ring 17 and rotor 31 is thrust bearing 47 against the cam repulsion of ball cam 13 .
[0040] Pilot clutch 19 includes multi-plate clutch 49 . The clutch 49 is disposed between housing 3 and cam ring 17 . Armature 53 is disposed proximate to the front of clutch 49 . The armature is connected to a spline 3 a of housing 3 . The spline 3 a is also connected with outer plates 75 A. Armature 53 may be splined to hub 9 .
[0041] Rotor 31 is operated by electromagnet 51 . Inserted with some play in recess 57 of rotor 31 is yoke 55 of electromagnet 51 . Rotor 31 is supported rotatably to yoke 55 by seal bearing 59 .
[0042] Electromagnet 51 is fixed to the casing of the vehicle body. Electromagnet 51 connects to a battery via lead wire 29 . The operation of magnetization or demagnetization is controlled by a controller.
[0043] Rotor 31 , clutch 49 and armature 53 define line 61 of magnetic force (path of magnetic flux) from electromagnet 51 .
[0044] Disposed in rotor 31 is ring 63 of non-magnetic stainless steel. The ring prevents the magnetic flux 61 of magnetic force from escaping. Clutch 49 includes notch 65 located in correspondence with ring 63 . Notch 65 prevents the magnetic flux 61 of magnetic force from escaping and leaking.
[0045] Disposed between thrust bearing 47 and rotor 31 is spacer 73 of a washer. Spacer 73 is made of non-magnetic material such as aluminum or stainless steel. The spacer 73 prevents the leakage of the magnetic flux 61 of electromagnet 51 to cam ring 17 .
[0046] Clutch 49 , as shown in FIGS. 2 and 3, includes, for example, four outer plates 75 A and three inner plates 77 A alternately stacked on each other. As to the stack, outer plates 75 A 2 are located at both ends of clutch 49 . The arrangement allows inner plates 77 A to be interposed between outer plates 75 .
[0047] Outer plates 75 A are splined to housing 3 . Inner plates 77 A are splined to cam plate 17 . For the achievement of spline connection, the outer periphery of each outer plate 75 A includes arc-shaped engagement lugs 79 formed at angular intervals of 90 degrees. The inner periphery of each inner plate 77 A includes arc-shaped engagement lugs 81 formed at angular intervals of 90 degrees. Each plate 75 A, 77 A includes four arc-shaped holes 76 , 78 for hydraulic lubrication therethrough.
[0048] Neighboring plates 75 A, 77 A slide against each other. Formed on plate 77 A are lubrication grooves 85 for hydraulic lubrication.
[0049] Lubrication grooves 85 are formed on one of sliding sides 75 Ab, 77 Aa. In FIG. 3, both sides 77 Aa and 77 Ab of each inner plate 77 A of the embodiment are formed with lubrication grooves 85 . The grooves include narrow grooves 85 a and 85 b on the both sides 77 Aa, 77 Ab of inner plate 77 A. Grooves 85 a, 85 b transversely extend between the inner and outer peripheries of inner plate 77 A. Grooves 85 a, 85 b cross each other at an angle of, for example, 90 degrees. The radial component of each of the grooves 85 a, 85 b circulates a lubrication oil from the inside to the outside of inner plate 77 A. The tangential component of each groove 85 a, 85 b retains a lubrication oil.
[0050] The both sides 75 Aa, 75 Ab of outer plate 75 A are flattened without lubrication grooves. The flatting includes a minute unevenness at a surface roughness less than 10 im.
[0051] The combination of outer plate 75 A and inner plate 77 A negate an air gap therebetween, the side of outer plate 75 A facing armature 53 being without lubrication grooves. On the other hand, inner plates 77 A, being interposed between outer plates 75 A, slide against outer plates 75 A. Thus, the formation of lubrication grooves is limited to a necessary minimum. This reduces air gaps due to the lubrication grooves 85 . The reduction prevents reduction in magnetic force, thus improving magnetic flux efficiency.
[0052] In the structure, electromagnet 51 attracts armature 53 along magnetic flux 61 of magnetic force when magnetizing. The armature presses and engages clutch 49 . The engagement produces a pilot torque. The pilot torque allows a driving force of the engine to be applied to ball cam 13 through housing 3 , clutch 49 , and cam ring 17 . The thrust force of the cam allows pressing member 15 to press and engage primary clutch 11 under a thrust force. The engagement allows coupling 1 to be connected.
[0053] The connection of coupling 1 allows the rear differential to be connected to the engine. The connection reduces the vehicle to four-wheel drive. At this time, the control of the magnetic force of electromagnet 51 in magnitude by a controller allows the pilot torque of clutch 49 to be changed due to sliding. The change allows thrust force of ball cam 13 to be changed. The change allows connecting force of primary clutch 11 and coupling 1 to be adjusted.
[0054] The adjustment of the connecting force of coupling 1 allows the torque distribution ratio between front and rear wheels of the vehicle to be adjusted.
[0055] When electromagnet 51 demagnetizes, the pilot torque of clutch 49 disappears. The disappearance allows primary clutch 11 to be disengaged. The disengagement allows coupling 1 to be disconnected. The disconnection of coupling 1 allows the rear differential to be separated from the shaft 5 . The vehicle becomes a two-wheel drive with front-wheel drive.
[0056] An oil is poured into shaft 5 , housing 3 and rotor 31 through oil hole 67 provided to housing 3 . After pouring the oil, ball 68 seals oil hole 67 .
[0057] Disposed between housing 3 and hob 9 is X-ring 37 . Between the housing 3 and rotor 31 , O-ring 39 is disposed. Between rotor 31 and hub 9 , X-ring 41 is disposed. The respective rings prevent the leakage of oil to the outside.
[0058] The sealed oil is stored in oil reservoir 33 provided to hub 9 . Hub 9 has radial oil passage 69 in communication with reservoir 33 . When hub 9 rotates, the oil flows from reservoir 33 through passage 69 . The oil lubricates primary clutch 11 and ball bearing 43 . In addition, the oil lubricates ball cam 13 , thrust bearing 47 , clutch 49 , X-rings 37 , 41 .
[0059] In the above-embodiment, the both sides 77 Aa, 77 Ab of inner plates 77 A are formed with lubrication grooves 85 . Both sides of each outer plates 75 A are formed without lubrication grooves. Inner plates 77 A, being interposed between outer plates 75 A slide against outer plates 75 A,. The formation allows grooves 85 to be limited to a necessary minimum. The formation of grooves 85 reduces air gaps needed to be produced. This reduction prevents the lowering of magnetic force, thus improving magnetic flux efficiency.
[0060] The improvement of magnetic flux efficiency allows magnetic flux to be guided efficiently to armature 53 , thus obtaining pilot torque by clutch 49 .
[0061] The loss of exciting power to electromagnet 51 reduces remarkably. The reduction reduces load of a battery, thus improving fuel costs of the engine. The electromagnet 51 is small-sized, and the whole coupling 1 becomes lighter and more compact.
[0062] The formation of lubrication grooves 85 on the both sides 77 Aa, 77 Ab of all inner plates 77 A allows for their use as common inner plate components.
[0063] [0063]FIG. 4 shows the second embodiment. Corresponding identical members to the first embodiment are attached with identical reference characters. The description omits repetition.
[0064] [Second Embodiment]
[0065] The second embodiment differs in the formation of lubrication grooves and is identical to the first embodiment in other structures.
[0066] Respective inner and outer plates 77 B, 75 B include lubrication grooves 85 , 87 formed on one side 77 Ba, 75 Ba thereof. The opposite side 77 Bb, 75 Bb are flattened without lubrication grooves. The sides 77 Ba, 75 Ba with lubrication grooves 85 , 87 contact with the neighboring flat sides 75 Bb, 77 Bb, thus allowing the stacking of outer and inner plates 77 B, 75 B each other.
[0067] According to the stacked plates, lubrication grooves are not provided to both of facing sides 77 Bb and 75 Ba or 77 Ba and 75 Ab of neighboring plates, but to one of the facing sides (one side) 77 Ba and 75 Ba for hydraulic lubrication. The formation of lubrication grooves on one side 77 Ba, 75 Ba at siding portions allows the lubrication grooves to be limited to a necessary minimum. This reduces air gaps produced due to the formation of lubrication grooves 85 , 87 . This reduction prevents the lowering of magnetic force, thus improving magnetic flux efficiency.
[0068] [Third Embodiment]
[0069] The third embodiment will be described with reference to FIG. 5. The third embodiment has outer plates 75 C of clutch 49 formed with lubrication grooves.
[0070] Outer plates 75 C are stacked on neighboring inner plates 77 C and are located in the middle of the stacked plates. Both sides 75 Ca, 75 Cb of outer plates 75 C are formed with lubrication grooves 87 . Another outer plates 75 D are located at both ends in the stacked plates. The outer plates 75 D each have lubrication grooves 87 on a side 75 Da facing inner plate 77 C. The opposite side 75 Db thereof is flat without a lubrication groove. The flat sides 75 Db face armature 53 and rotor 31 to rotate integrally with outer plates 75 D, and they does not slide each other. The both sides 77 Ca, 77 Cb of inner plates 77 C are flattened without lubrication grooves.
[0071] The outer plates 75 C, 75 D allow lubrication grooves 87 to be limited to a necessary minimum.
[0072] [Fourth Embodiment]
[0073] The embodiment employs outer plates 75 C, 75 D as outer plates and inner plates 77 A as inner plates. Both sides 77 Aa, 77 Ab of inner plates 77 A and both sides 75 Ca, 75 Cb of intermediate outer plates 75 C, and one side 75 Da of outer plates 75 D located at both ends in FIG. 7, have lubrication grooves 85 , 87 formed thereon. The sides each slide against the neighboring plate to form sliding faces. The formation of lubrication grooves 85 , 87 allows hydraulic lubrication for smooth rotation.
[0074] On the other hand, the opposite sides 75 Db of outer plates 75 D are formed without lubrication grooves. One opposite side 75 Db faces rotor 31 . The other opposite side 75 Db faces armature 53 .
[0075] The outer plates 75 D, or a clutch plate, rotate integrally with armature 53 and rotor 31 , with one side 75 Db not sliding against armature 53 and rotor 31 . Thus, lubrication grooves for hydraulic lubrication are unnecessary.
[0076] The contact area between outer plate 75 D and rotor 31 , or armature 53 is enlarged. The enlargement enhances magnetic permeability, thus improving the attraction force of electromagnet 51 , thus increasing the engagement force of pilot clutch 19 . The result is the increased engagement force of primary clutch 11 , thus allowing stable power transmission.
[0077] No forming lubrication grooves on a side 75 Db of outer plate 75 D allows rotor 31 and outer plate 75 D not to rub together when rotor 31 screws into housing 3 , thus preventing the surface of rotor 31 from damage.
[0078] Side 75 Db of one of both outer plates 75 D may be formed with lubrication grooves. This improves magnetic permeability, thus allowing the engagement force of pilot clutch 19 to increase.
[0079] [Fifth Embodiment]
[0080] The embodiment will be described with reference to FIG. 8. The embodiment has pilot clutch 19 with sliding sides that are surface treated. Regarding the surface treatment, clutch plates are gas or salt-bath nitrided. The surface treatment allows the surfaces of the clutch plates to be hardened. This hardening improves the efficiency of friction, sliding ability and durability of the sliding sides of the clutch plates.
[0081] The surface treatment is applied to both sides 77 Ea, 77 Eb of all inner plates 77 E, both sides 75 Fa, 75 Fb of the intermediate outer plates 75 F, and the sides 75 Ga of both end outer plates 75 G, and not to the opposite sides 75 Gb.
[0082] The outer plates 75 G, or a clutch plate, rotate integrally with armature 53 and rotor 31 , with the sides 75 Gb not sliding on armature 53 and rotor 31 . This does not need improved friction efficiency, and surface treatment is unnecessary
[0083] Without surface treatment to the sides 75 Gb of outer plates 75 G, the dispersion and interruption of magnetic flux does not occur due to the treatment layer. This improves magnetic permeability. The improvement of magnetic permeability allows the attraction force of electromagnet 51 to increase. This increases the engagement force of pilot clutch 19 . The result increases the engagement force of primary clutch 11 , thus allowing stable power transmission.
[0084] Side 75 Gb of one of both outer plates 75 G may be formed with a surface treatment. This improves magnetic permeability, thus allowing the engagement force of pilot clutch 19 to increase.
[0085] The entire contents of Japanese Patent Applications P2001-194892 (filed on Jun. 27, 2001) and P2001-64752 (filed on Mar. 8, 2001) are incorporated herein by reference.
[0086] While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. | An electromagnetic wet clutch system includes operation members configured to magnetically work. The system includes a set of clutch plates configured to engage by the operation members. The set of clutch plates includes first plates with first sides. Respective one of the first sides is configured to contact respective one of the operation members. At least one of the first sides is boundary-lubricative. | 5 |
[0001] This application claims priority of U.S. Provisional Patent Application Ser. No. 61/217,622, filed Jun. 1, 2009 and entitled “Viking Knit All-In-One Tool”. This application also claims priority of U.S. Provisional Application Ser. No. 61/336,370, filed Jan. 21, 2010 and entitled “Lazee Daizee Viking Knit Matrix Cone Tool”. The disclosures of these two provisional patent applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to the art and jewelry craft industry, and more particularly to a hand tool for making the Viking Knit weave from wire for use in art and jewelry pieces.
[0004] 2. Related Art
[0005] Viking Knit is an old, traditional wire weave made by a looping technique of the wire around a cylindrical form such as a wooden dowel. The resulting woven wire tube is then gradually reduced in diameter by sequentially pulling the tube through a series of holes of diminishing diameters. Then the drawn Viking Knit is formed into jewelry and other decorative objects.
[0006] Methods for fabrication of traditional Viking Knit are centuries old, and have included the use of a solid, cylindrical form such as bone, wood in various sizes, wooden dowels, pencil shapes or more recently, even Allen wrenches. These items are most often attached to a stationary device such as a vise or clamp for ease of manufacture.
[0007] According to the prior art practice, before beginning the Viking Knit weave, a start-up bundle of wire loops must be constructed. This is a hand-formed, single-use group of looped wires than can be made by wrapping wire around a thin, solid form, approximately 1″ by ⅛″, to form loops that are then twisted or made stationary at one end. When the loose loops are parted they are shaped into a semi-flat flower petal-like form that is then bent over one end of the dowel, pencil or Allen wrench, and held in place by the wire shape itself, adhesive tape, additional wire or other means. The bent over form is then used as a base to begin the wire weaving process for the Viking Knit technique. Because the loose loops are not rigid, it can be difficult to get the Viking Knit weave started.
[0008] The prior art start-up bundle does not spin freely about a vertical axis as the Knit forms at the end of the dowel, pencil or Allen wrench. Later, the start-up bundle is used as a means of pulling the finished Viking Knit through a draw plate, a series of progressively smaller sized drilled holes, often made from a piece of wood. The Knit is drawn through increasingly smaller holes in the plate, allowing the Knit to reduce in diameter and increase in length. The start-up bundle is then cut away and discarded. Therefore, a new start-up bundle is created for each project.
[0009] New wire is added making a small hook at one end of the new wire or by inserting the new wire randomly into the existing Knit and holding it in place until the attachment is made following several additional stitches. An awl or other sharp, pointed instrument is used sometimes to lift the wire from the dowel, pencil or Allen wrench, whereby new stitching is created underneath. Also, preferably, the tool of the present invention is provided in a kit with a separate pointed instrument, like a thumb tack or push pin.
[0010] An example of one prior art device for making the Viking Knit is the kit currently advertised at CoolToolChick.corn (http://www.cooltoolchick.com/viking.html).
SUMMARY OF THE INVENTION
[0011] This invention in one embodiment comprises a cylindrical rod with a rotatable and removable loop head inserted into the center of the top end of the rod. Preferably, the cylindrical rod is a hexagonal, nylon plastic rod. Alternatively, the rod may be dodecagonal. The loop head is made from, for example, a 6-loop Bali silver bead cap secured to the top of a rivet. Alternatively, the loop head may be molded from plastic with 6 or 12 outwardly, radially extending circumferential loops. The loop head is inserted into a vertical hole drilled into the top end of the rod, wherein the loop head is held by gravity, but able to spin or rotate freely in the hole. The vertical hole has an axis substantially parallel to, or even coincident with, the axis of the rod.
[0012] Preferably, the rod also has an anchor hole, drilled diagonally through the rod near its top end, for receiving and securing a wire. Also, preferably, the rod has indicia on its outer surface near its top, for indicating approximately the loop length in the first row of the Viking Knit. Metal wires, varying in size, most generally 32-18 gauge, copper-based, color coated wires and precious metal wires, are woven through the loop head and around the rod to form tubular Viking Knit stitches.
[0013] Preferably, the rod also has a conical wire wrap attachment at the bottom of the rod for making wired end caps to cover or enclose the finished Viking Knit weave. The conical wire wrap attachment has a hole drilled transversely through it near its bottom for receiving a wire.
[0014] Also, preferably, the tool of the present invention is provided in a kit with a separate draw plate for shaping and sizing the finished Viking Knit. The draw plate may be a sturdy, stiff plastic block with several holes of diminishing diameter drilled through it. The finished Viking Knit is sequentially pulled through several holes of diminishing diameter in order to better align the weave stitches and size the outer diameter of the weave.
[0015] In another embodiment, this invention comprises a hollow cone with a free-turning loop head inserted in either or both ends of the cone. Preferably, the hollow cone is hexagonal and/or dodecagonal. Also, preferably, the hollow cone has two rows of about 5/64 inch anchor holes about ½ inch apart, drilled into the cone on two sides thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a side, perspective view of one embodiment of the present invention in a hexagonal rod.
[0017] FIG. 2 is an exploded view of the embodiment depicted in FIG. 1 .
[0018] FIG. 3 is a side, perspective, detail view of the six (6)-loop head depicted at the top in FIG. 2 .
[0019] FIG. 4 is a side view of the embodiment depicted in FIG. 1 .
[0020] FIG. 5 is a cross-sectional view of the embodiment depicted in FIG. 4 , the section being taken along line 5 - 5 in FIG. 4 .
[0021] FIG. 6 is a side perspective view of the embodiment depicted in FIG. 1 , but with a first row of wire loops hanging from the loop head.
[0022] FIG. 7 is a side, perspective, detail view of the first row of wire loops depicted in FIG. 6 .
[0023] FIG. 8 is a side, perspective view of the embodiment depicted in FIG. 6 , but with an additional second row stitch of Viking Knit hanging from the first row of wire loops.
[0024] FIG. 9 is a side, perspective, detail view of the first row of wire loops and second row stitch of Viking Knit depicted in FIG. 8 .
[0025] FIG. 10 is a side, perspective view of the embodiment depicted in FIG. 8 , but with an additional third through twelfth rows of stitches of Viking Knit hanging from the first row of wire loops and second row stitch of Viking Knit.
[0026] FIG. 11 is a perspective, detail view of the loop head, first row of wire loops and 12 rows of stitches of Viking Knit depicted in FIG. 10 .
[0027] FIG. 12 is a perspective, detail view of the 12 rows of stitches of Viking Knit depicted in FIG. 10 .
[0028] FIG. 13 is a side, perspective view of another embodiment of the present invention in a dodecagonal rod.
[0029] FIG. 14 is an exploded view of the embodiment depicted in FIG. 13 .
[0030] FIG. 15 , is a side, perspective, detail view of the twelve (12)-loop head depicted at the top in FIG. 14 .
[0031] FIG. 16 is a top view of another embodiment of the present invention in a dodecagonal cone.
[0032] FIG. 17 is a side, perspective view of the embodiment depicted in FIG. 17 , with a six (6)-loop head in the small end of the cone, and with a twenty-four (24)-loop head in the large end of the cone.
[0033] FIG. 18 is an exploded view of the embodiment depicted in FIG. 17 .
[0034] FIG. 19 is a bottom perspective, detail view of the twenty-four (24)-loop head depicted at the bottom in FIG. 18 .
[0035] FIG. 20 is a top, perspective, detail view of the twenty-four (24)-loop head depicted in FIG. 19 .
[0036] FIG. 21 is a top view of another embodiment of the present invention in a twenty-four (24)-sided cone.
[0037] FIG. 22 is a side, perspective view of the embodiment depicted in FIG. 21 , with a six (6)-loop head in the small end of the cone, and a twenty-four (24)-loop head in the large end of the cone.
[0038] FIGS. 23-50 is a set of photographs showing the sequential steps of using an embodiment of the invention according to the description in the section below called “Detailed Use of A Preferred Tool”.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Referring to the Figures, there are depicted several, but not all, preferred embodiments of the present invention.
[0040] FIG. 1 depicts a side, perspective view of one embodiment 10 of the present Viking Knit hand tool in a hexagonal rod 12 . Rod 12 has an anchor hole 14 drilled into it near its top. Rod 12 has a six (6)-loop head 16 inserted into its top end, and a conical tip 18 secured to its bottom end. Tip 18 has hole 20 drilled through it generally perpendicular to the axis of rod 12 .
[0041] FIG. 2 depicts an exploded view of the hand tool 10 depicted in FIG. 1 . From FIG. 2 it is clear that loop head 16 has six (6) radially extending circumferential loops 22 and a central shaft 24 which fits into central axial hole 26 at the top of rod 12 .
[0042] FIG. 3 depicts a detail view of the six (6)-loop head 16 depicted at the top of FIG. 2 .
[0043] FIG. 4 depicts a side view of the hand tool 10 depicted in FIG. 1 .
[0044] FIG. 5 depicts a cross-sectional view of the hand tool 10 depicted in FIG. 4 . From FIG. 5 it is clear that central axial hole 26 extends from the top of rod 12 parallel to the axis of the rod down into anchor hole 14 , which anchor hole is drilled diagonally transversely through rod 12 .
[0045] FIG. 6 depicts a side, perspective view of the hand tool 10 depicted in FIG. 1 , but with an additional first row of wire loops 28 hanging from the loop head 16 .
[0046] FIG. 7 depicts a detail view of the first row of wire loops 28 depicted in FIG. 6 .
[0047] FIG. 8 depicts a side, perspective view of the hand tool 10 depicted in FIG. 6 , but with an additional second row stitch 30 of Viking Knit hanging from the first row of wire loops 28 .
[0048] FIG. 9 depicts a detail view of the first row of wire loops 28 and additional second row stitch 30 of Viking Knit depicted in FIG. 8 .
[0049] FIG. 10 depicts a side, perspective view of the hand tool 10 depicted in FIG. 8 , but with an additional third through twelfth rows of stitches 32 of Viking Knit hanging from the first row of wire loops 28 and second row stitch of Viking Knit 30 . From FIG. 10 , it is clear that the outer surface of the rod shapes the inside size and shape of the Viking Knit.
[0050] FIG. 11 depicts a perspective, detail view of the loop head 16 , removed from the top of the rod as the weave is created and extended upwardly, first row of wire loops 28 and twelve rows of stitches 30 and 32 of Viking Knit depicted in FIG. 10 . FIG. 11 also shows the inner diameter of the tube (IDT) made by the surface of the rod.
[0051] FIG. 12 depicts a perspective, detail view of the twelve rows of stitches 30 and 32 of Viking Knit depicted in FIG. 11 , with the loop head removed from the weave by clipping the first row of wire loops. FIG. 12 also shows the inner diameter (IDT) of the woven wire tube.
[0052] FIG. 13 depicts a side, perspective view of another, alternative embodiment 110 of the present Viking Knit hand tool in a dodecagonal rod 112 . Rod 112 has an anchor hole 114 drilled into it near its top. Rod 112 has a twelve (12)-loop head 116 inserted into its top end, and a conical tip 118 formed at its bottom end. Tip 118 has hole 120 drilled through it generally perpendicular to the axis of rod 112 . Recess 115 in the outer surface of the rod indicates for the length of the first row of the wire loops, and allows for additional room for the wire to slide under earlier stitches of wire and continuance of the weaving.
[0053] FIG. 14 depicts an exploded view of the hand tool 110 depicted in FIG. 13 . From FIG. 14 it is clear that loop head 16 has twelve (12) radially extending circumferential loops 122 and a central shaft 124 which fits into the top of rod 112 .
[0054] FIG. 15 depicts a side, perspective, detail view of the twelve (12)-loop head 116 depicted at the top in FIG. 14 .
[0055] FIG. 16 depicts a top view of another, alternative embodiment 210 of the present Viking Knit hand tool in a dodecagonal cone 212 . Cone 212 has a series of anchor holes 214 on two sides, and an opening 226 in its top end.
[0056] FIG. 17 depicts a side, perspective view of hand tool 210 , with a six (6)-loop head 216 in the small end of the cone, and with a twenty-four (24)-loop head 217 in the large end of the cone. Head 216 has six (6) radially extending circumferential loops 222 . Head 217 has twenty-four (24) radially extending circumferential loops 223 .
[0057] FIG. 18 depicts an exploded view of the hand tool 210 depicted in FIG. 17 . From FIG. 18 it is clear that head 216 with loops 222 has central shaft 224 which fits into hole 226 in the top of cone 212 . Also from this FIG. 18 it is clear that head 217 with loops 223 has a plurality of interior legs 225 which collectively fit into a hole in the bottom of cone 212 .
[0058] FIG. 19 depicts a bottom, perspective, detail view of the twenty-four (24)-loop head 217 depicted at the bottom of FIG. 18 . Head 217 has twenty-four (24) radially extending circumferential loops 223 , and several upwardly extending, spaced-apart legs 225 for fitting into the bottom of cone 212 .
[0059] FIG. 20 depicts a top, perspective detail view of the twenty-four (24)-loop head 217 depicted at the bottom of FIG. 18 . From FIG. 20 it is clear that head 217 has six (6) spaced-apart legs 225 .
[0060] FIG. 21 depicts a top view of another, alternative embodiment 310 of the present Viking Knit hand tool in a twenty-four (24)-sided cone 312 . Cone 312 has a series of anchor holes 314 on two sides, and an opening 326 in its top end.
[0061] FIG. 22 depicts a side, perspective view of hand tool 310 , with a six (6)-loop head 316 in the small end of the cone, and with a twenty-four (24)-loop head 317 in the large end of the cone. Head 316 has six (6) radially extending circumferential loops 322 . Head 317 has twenty-four (24) radially extending circumferential loops 223 .
Detailed Use of a Preferred Tool:
[0062] Referring specifically to FIGS. 23-50 , there are shown illustrations of the preferred methods of using the tool, which may be understood by reference to the following steps:
[0063] With a black permanent marker, draw a line around the hex rod approximately ¼″ from the top of the rod or apply the pin striping tape at the same height. Insert the loop head central shaft into the top hole. See FIG. 23 .
[0064] Cut 30″ of #26 gauge wire. Holding the rod in your left hand, insert one end of the wire into the top of the diagonal anchor hole, extending about 1 inch. Press the “anchor wire” down with your left forefinger to hold in place. See FIGS. 24 and 25 .
[0065] Row 1: Insert the remaining wire down through one of the head loops above the anchor hole. See FIG. 26 . Gently pull the wire down then cross over the top of the previous wire to form an elongated loop. See FIG. 27 . Use the black line as a guide to establish the length of the loop.
[0066] Use your left thumb to help hold the first loop in place. See FIG. 28 . Bring the wire down through the next head loop on the right. Pull the wire down, taking care not to distort the first loop. Keep the wire on top and cross to the right. See FIG. 29 .
[0067] Make 6 loops around. Keep the stitches similar in size and as evenly spaced as possible. Use the shape of the rod as a guide placing one loop on each side of the hex. This way, the outer surface of the rod determines the size and shape of the inside of the Viking Knit tube. The flat sides also allow extra space to get under the wire. Use the pin tool to help with spacing and to lift the wire if necessary. See FIG. 30 .
[0068] The pin tool is sharp. Keep the plastic cover on the point when not in use. Keep away from animals and small children. See FIG. 31 .
[0069] Row 2: Bring the wire, right to left, behind the first loop (on row one) at the bottom where the wires cross. See FIG. 32 . Pull through then swing the wire back to the right to form a small loop. See FIG. 33 . Working to the right, repeat on each loop around. See FIGS. 34 and 35 .
[0070] Row 3: Continue another round of loops. Use the first 3-6 rows (or more if necessary) to develop a consistent pattern.
[0071] The first few rows of Viking Knit can be cut away later, so don't worry if they aren't perfect. You will be amazed how much the draw plate helps to reposition and even out the stitches.
[0072] Row 4: Pull the beginning anchor wire out of the diagonal hole and cut close to work. Continue working around with the main wire.
[0073] As you continue to work, check to make sure you still have 6 loops on the rod.
[0074] Row 5 and beyond: continue working loops around.
[0075] Periodically slide the knit out the top of the rod every few rows, otherwise it may be hard to remove later. If it becomes stuck twist the knit tube around the rod to loosen.
[0076] Adding wire: move the last loop formed so that it is over the diagonal anchor hole at the top of the rod. See FIG. 36 .
[0077] Cut another length of #26 wire, 24-30 inches, or whatever length you are most comfortable working with.
[0078] Insert one end of the wire through the last wire loop and into the diagonal hole, extending about 1 inch. See FIG. 37 . Press the “anchor wire” down end with your forefinger to hold in place. Bring the free end of the wire under the next loop and continue. See FIG. 38 . Work 3-4 rows then cut all wires except the main wire to continue working.
[0079] Determining length: The final length of your knit depends on how many loops you start with, how far down you draw the knit and the size wire you use.
[0080] As a general rule, if you start with 6 loops #26 gauge and make a 6-inch length of Viking Knit, you can gain 2-3 inches or more depending on how small you reduce the tube. The smaller the hole draw the longer the knit. The number of feet needed varies but about 15 feet of wire should be enough for a bracelet.
[0081] Preparing the knit: Remove the completed length of Viking Knit from the hex rod. See FIG. 39 . Clip the top loops to remove the loop head and remove any loose wires. See FIG. 40 .
[0082] Roll the knit between the soft side of the fabric cloth several times. This helps align the stitching and makes drawing easier. See FIG. 41 .
[0083] Cut 3 pieces of #26 wire about 12 inches each. Insert the wires in through loops on rows 2 or 3. See FIG. 42 . Fold wires together and twist. See FIG. 43 . This will give you something to hold onto as you draw the knit through the draw plate. They will be removed later.
[0084] Draw plate: pull the knit through the largest hole several times. See FIG. 44 . Continue to pull through each hole several times until the desired length and width is achieved.
[0085] You can cut the Viking Knit to any length—it will not unravel. Clip any sharp ends (where added wires began and ended) that may protrude.
[0086] About wire: many colored wires have a copper base with color coating on top. They are generally quite durable, however you can scratch the surface color off if not careful.
[0087] Different gauges of wire change the length and width of the knit: #24 and #28 gauge wires are suitable. #20 gauge is usually too hard to work.
[0088] To make a smaller diameter knit experiment by starting with 4 loops and #26 gauge or 5 loops with #28 gauge. This will allow you to pull the knit through the smallest hole on the draw plate. Just skip one or two loops on the loop head and space accordingly around the rod.
[0089] Making Coiled Wire End Caps
[0090] Use the Viking Knit hand tool described above to make two 3-4 inch lengths of coil.
[0091] Cut a 12″ length of #20 gauge wire and insert one end into the small hole at the cone end of the hex rod. See FIG. 45 .
[0092] Holding the rod with your right hand and the long wire in your left, turn the rod to wind the wire 3-4 times around the cone. See FIG. 46 . Add the coil and continue to wind. See FIGS. 47 and 48 .
[0093] Cut the wire ½-inch at the bottom and make a small loop. See FIG. 49 . Cut the top wire to release the coil. See FIG. 50 . Finish by adding a loop at the top. The technique for making a Viking Knit with the cone tool is essentially the same as described above.
Advantages:
[0094] The Viking Knit Hand Tool eliminates the need for repeatedly creating a new start-up bundle for each project and instead uses a fitted, removable, free-turning, interchangeable loop head inserted into the top center of the rod according to the invention.
[0095] The hard plastic nylon rod material is more durable than a dowel or pencil. The vertical shape is preferable over a bent Allen wrench. Constant removal of the Viking Knit wire weave can wear down other, softer materials. The lightweight material is portable and does not necessitate the use of a stationary stand, such as a vise or clamp.
[0096] A diagonally drilled anchor hole makes startup, and the addition of new wire, easier by creating tension and a stationary direction for the new wire to be attached. In use, the last stitch of the Viking Knit is aligned over the top diagonal hole on the rod. The new wire is inserted through the existing knit stitch and down through the diagonal hole extending about 1″. A forefinger is placed on the extended end to provide tension. The new wire is in position for the next stitch. After several rows of stitching the 1″ extended end and the original wire are cut away leaving the new wire.
[0097] A starting line, indent in the outer surface of the rod, or loop length guide, is provided at the top of the rod, just below the wire loop attachment. The line aids in positioning the first row of Viking Knit.
[0098] The hex shape, plastic nylon rod reduces the need for an awl or other pointed instrument to lift the wire from the rod because the flat surfaces allow more clearance room for getting under the initial wire and adding new stitches. Lessening the use of an awl or other pointed instrument to move the wire also reduce the changes of accidentally scratching the surface of the wire, especially in the case of copper-based, color coated wires.
[0099] The six sides of the rod also compliment the 6-loop metal head insert. This collaboration is helpful in initially with forming and positioning the first rows of Viking Knit stitches. The rod is constructed of Quadrant Nylon Hexagon Bar, ¼″ across flats (USP item #47521), measuring approximately 6 inches in length (vertical).
[0100] A vertical 1/16-inch hole, drilled in the top of the rod approximately ½″ in depth is referred to as the central axial hole.
[0101] A ⅛-inch adhesive tape strip may be applied around the circumference of the rod approximately ¼′inch from the top of the rod, referred to as the “loop length guide”. Alternatively, a black line can be drawn with a permanent marker.
[0102] In one embodiment, the “wire loop attachment” is comprised of one ⅛″×⅜″ aluminum blind rivet and one 6-loop Bali silver bead cap, #C2010 0.45 grams, 4×10 mm made in Indonesia (beads-park.com). The bead cap is permanently adhered to the top of the rivet. The rivet and bead cap are then inserted into the central axial hole at the top of the rod.
[0103] A second 1/16-inch hole, drilled at a slight diagonal, starting approximately 1-inch from the top of the rod, allows the addition of start up or new wire. It is referred to as the “anchor hole”.
[0104] A cone wire cap tool is permanently attached at the bottom of the rod. The cast metal cone is approximately ⅞-inch in length, part #BM60606-PE-003. A 1/16-inch hole is drilled through the metal cone near the smallest point. The hole is used to insert a base wire. Coiled wire, beads or other materials are added to the base wire. The base wire is then wrapped about the coil shape to form an end cap. Alternately, the hex rod itself may be shaped or sharpened at the bottom end to form a cone shape, eliminating the need for a metal cone. The cone wire cap tool is not essential to the creation of the Viking Knit weave; it offers a complimentary alternative finishing technique. However, the cone wire cap is also convenient for another important function associated with the Viking Knit Hand Tool. If the woven tube of wire becomes excessively tight on the rod or cone, the tube may be taken off, the rod or cone turned over and passed through the inside of the tube like a reamer. This way, due to the increased diameter of, for example, tip 18 ( FIG. 1 ), or tip 118 ( FIG. 14 ), the inner diameter of the woven tube will be increased, without the danger of scratching the wire, and the woven tube may be conveniently reinstalled on the rod or cone for additional weaving with a more relaxed fit.
[0105] One advantage of the Viking Knit Cone Tool is that, instead of limiting the traditional Viking Knit woven wire construction to a single, cylindrical shape, the cone form allows the woven knit to be formed into additional sizes and shapes, like open or closed cones, that add new dimension and opportunities for its use. The cone also eliminates the need to repeatedly create a new start-up bundle for each project and instead uses two or more fitted, removable, free-turning, interchangeable metal or plastic loop heads that can be inserted at either end of the cone. Heads can have a varying number of loops. The shape of the woven tube around the cone allows design options not available on the traditional straight rods.
[0106] The hollow cone has six flat sides at the smaller end (¼″) converting to 12 or 24 flat sides at the larger end (1¼″). The overall length is 5″. The six sides of the cone compliment a 6-loop plastic or metal head insert. A 12- or 24-loop metal or plastic head is used at the larger end. The flat surfaces are useful initially in and positioning the first rows of Viking Knit stitches: one or two stitches on each flat surface are useful for measuring stitch length, girth and shape.
[0107] The hollow cone is constructed of a plastic carbon and/or nylon reinforced material. Horizontal anchor hole sites of about 5/64 inch diameter are aligned at about ½ intervals down the length of the cone on one or both sides. The small end of the tool is a ¼″ hexagon shape, graduating to 1¼″ with 12 or 24 sides at the large end. Six-loop and a 24-loop head attachments are inserts at either ends of the cone.
Alternatives:
[0108] The hex tool may be modified in a number of respects, all without departing from the original intent and concept.
[0109] The diameter, length and hex shape could be changed to a larger or smaller diameter and the number of flat-sided surfaces could also be changed, for example, a ⅜″ rod with four sides or a ½″ rod with eight sides.
[0110] The rod material could be changed to wood, metal or other plastic materials. It can be solid or hollow. The rod may be round in diameter and not have flat sides at all. It could be attached to a stationary surface if necessary by means of a stand, vise or clamp.
[0111] The wire loop attachment can be shaped of a one-piece solid metal or plastic material with an increased or decreased number of loops forming the head. The size, depth and diameter of the rivet or pin inserted into the rod may vary in size.
[0112] Also, interchangeable wire loop attachments, of varying loop length and varying loop holes, could be used alternately with the same rod size or different rod sizes, depending on the style of Viking Knit mesh desired. Thus one could mix-and-match a five loop wire loop attachment with a five-sided ½″ rod or a five-sided ¼″ rod.
[0113] The number of wire loops on the wire loop attachment head need not correspond to the same number of flat sides on the rod. The flat sides of the rod help make the Viking Knit wrapping technique easier but can also aide in the placement of the Viking Knit loops.
[0114] The metal cone wire wrap accessory could be manufactured as part of the actual rod by sharpening the end of the rod into a graduated cone shape with an insert hole drilled at the end.
[0115] An alternative method for making the permanent or semi-permanent starting line at the top of the rod could be fashioned by the use of painted, a routed crevice or by burning or engraving a line onto the material.
[0116] The diagonal anchor hole could be located at varying heights and vary in diameter. Additional anchor holes could be added as starting points or to accommodate more than one wire.
[0117] The diameter of the rod, the number of starting loops, the size of wire used and the draw plate holes all contribute to determining various textures, diameters and sizes of a completed Viking Knit weave project.
[0118] The cone material could be changed to wood, metal or other plastic materials. It can be solid or hollow. The cone may be totally round in diameter and not have flat sides at all. It could be attached to a stationary surface if necessary by means of a stand, vise or clamp.
[0119] The plastic or metal loop attachments can be shaped of a one-piece solid metal or plastic material with an increased or decreased number of loops forming the head.
[0120] Interchangeable wire or plastic loop attachments, of varying loop lengths and varying loop holes, could be used alternately with the same cone size or different cone sizes, depending on the style of Viking Knit mesh desired.
[0121] The number of wire loops on the wire loop attachment head need not correspond to the same number of flat sides on the cone. The flat sides of the cone help make the Viking Knit wrapping technique easier but can also be used as a teaching aide to indicate the correct placement of the Viking Knit stitches.
[0122] Horizontal or vertical anchor holes could be located at varying heights and vary in diameter. Additional anchor holes could be added as starting points or to accommodate more than one wire.
[0123] The diameters of the cone, the number of starting loops at either end, the size of wire used and the draw plate holes all contribute to determining various textures, diameters and sizes of a completed Viking Knit weave project.
[0124] The end of the cone can be altered to include an end cap tool can be with the addition of an about 5/64 inch hole drilled through the cone about ¼″ from the end. The hole is used to insert wire and wrap about the cone shape formed an end cap that may be used to complete a Viking Knit project.
[0125] Variations of this invention will occur to those skilled in the art. All such variations are intended to be within the scope and spirit of the Viking Knit Hand Tool, and not limited to those alternatives listed. A feature disclosed herein may be used together or in combination with any other feature on any embodiment of the tool. It is also contemplated that any feature may be specifically excluded from any embodiment of this tool.
[0126] Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims. | This invention in one embodiment comprises a cylindrical rod with a rotating, removable loop head inserted into the center of the top end of the rod. The loop head is inserted into a vertical hole drilled into the top end of the rod, wherein the loop head is able to rotate in the hole. The loop head has a plurality of outwardly radially extending circumferential loops that receive wire for bending and weaving into the Viking Knit. Preferably, the rod also has an anchor hole, drilled diagonally through the rod near its top end, for receiving and securing a wire. Preferably, the rod also has a conical wire wrap attachment at the bottom of the rod for making wired end caps to cover or enclose the finished Viking Knit Weave. In another embodiment, this invention comprises a hollow cone with a rotating, removable loop head inserted in either or both ends of the cone. | 3 |
This application is a continuation-in-part of application Ser. No. 259,883, filed May 4, 1981 now abandoned which was a continuation of application Ser. No. 158,184, filed June 10, 1980, now U.S. Pat. No. 4,295,881; which was a continuation of application Ser. No. 38,820, filed May 14, 1979, abandoned; which was a continuation-in-part of application Ser. No. 32,680, filed Apr. 23, 1979, abandoned.
BACKGROUND OF THE INVENTION
This invention relates to the separation of platinum group metals from various feedstock materials in a form suitable for further separation and purification.
Prior art pyrometallurgical methods for recovery of platinum group metals, sometimes referred to herein as "PGM's", from various feedstock materials by concentrating them in collector metals have not given entirely satisfactory results--in part--due to the long periods of time (residence time) required for the PGM's to accumulate in the collector metal and separate into a recoverable layer. This necessitates providing a multiplicity of sizes and types of furnaces for treatment of various feedstock materials.
For example, in processes employing electric arc furnaces the slag is heated by passing an electric current between submerged electrodes, through molten slag causing localized heating and temperature gradients which result in significant viscosity gradients in the melt. Higher slag viscosity impedes aggregation and settling of very fine particles of PGM's and collector metals as well as movement of the slag and thus slows the formation of a recoverable layer of PGM's associated with collector metal.
Another disadvantage of prior art processes for recovery of PGM's from finely divided material is a frequent requirement for pre-processing of the feedstock materials into forms that facilitate separation of the PGM's e.g. pelletization. As is well known in the art, pelletization involves comminution and mixing the feedstock material with appropriate fluxes, collector metals, binder and the like, and processing the mixture into larger particles of sufficient size and mass so that they form an open-structured layer on the slag surface and are carried, relatively intact, to the heating zone of whatever furnace is being used. Thus problems associated with segregation of the melt constituents and escape of reaction gases are avoided.
Another disadvantage of prior art proceseses is low tolerance for treating different types of feedstock material.
An exemplary feedstock material is PGM concentrates produced from chromite-bearing ore by processes including comminution, magnetic separation mineral dressing, flotation, and the like. The PGM's which include platinum, palladium, rhodium, ruthenium, iridium and osmium, are sometimes found in association with chromite-bearing ores at chromite grain boundaries, within chromite grains or in the gangue material associated with the ore and they are usually also associated with sulphides of nickel, copper and iron. Extensive deposits of platinum group metals associated with chromite bearing ores exist in the Republic of South Africa and the U.S.A., in particular, the Stillwater Complex in Montana. Of course, the many industrial forms of PGM's results in a large number of additional feedstock materials, other than ores, in which they may be found. Therefore, a versatile process that can recover PGM's from a variety of different feedstock materials, economically and efficiently, is very desirable. Typically, chromite occurs as stratiform or podiform deposits associated with ultramafic igneous rocks. PGM's are of significant industrial value finding application, for example, as catalytic or inert materials in many chemical reactions. They are used extensively in the petroleum industry as catalysts, in the making of dies for the manufacture of fiberglass, in the electrical industry for switch contacts, and for treating automotive exhaust gases in catalytic converters to render harmless oxides of nitrogen, carbon and sulphur. Other uses are for dental devices and jewelry. The major commercial production of platinum group metals from ores is limited to the Republic of South Africa, U.S.S.R., and Canada although there are recycling, purifying and fabricating facilities in many countries.
A traditional method for extracting platinum group metals from ores containing little or no chromite, such as the Merensky Reef ore in the Republic of South Africa, consists of comminution and flotation to produce a concentrate containing platinum group metals and sulphides of nickel, copper and iron. The concentrate is smelted in a continuous process with an average residence time of several hours in a submerged arc, carbon electrode furnace to form a metal matte, to which the platinum group metals report, and slag. The iron and sulphur in the matte are subsequently removed in a separate process step consisting of an air blast converter to which silica is added for reaction with the iron to form a fayalite slag. The slag is recycled in liquid form to the electric arc furnace for reheating and recovery of any entrained particles containing platinum group metals and ultimate discharge from the electric arc furnace as waste. The product from the converter is granulated and treated electrolytically to separate the nickel and copper and to produce a residue containing PGM's in a form suitable for separation and purification of the individual platinum group metals.
It has been found that if chromite-bearing ore containing platinum group metals is treated by this method, the residual chromite particles in the PGM feedstock interfere with the process steps and cause losses of platinum group metals and undesirable accretions in the furnace. It appears that chromite reacts with the carbon electrode material in electric arc furnaces to form ferrochrome which alloys with the platinum group metals and from which the platinum group metals cannot be readily extracted. In addition, chromite particles remote from the electrodes appear to settle out on the furnace walls and hearth forming the above-mentioned undesirable accretions which interfere with smooth operation of the furnace.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a PGM recovery process wherein a recoverable layer including collector metal and PGM's is rapidly formed, preferably within a few minutes, to reduce furnace residence time for various feedstock materials.
It is another object of the present invention to provide a process that can efficiently recover PGM's from a variety of feedstock materials and that does not require extensive pre-processing of the feedstock materials.
It is another object of the present invention to describe a versatile process for recovery of PGM's from various feedstock materials.
A further object of the invention is to describe a process for the treatment of chromite-bearing ores to recover platinum group metals therefrom. In the course of this description a process is described for recovery of nickel, copper and cobalt from the ore if these metals or minerals thereof occur together with platinum group metals.
These and other objects are achieved by the provision of a process which comprises the steps of:
introducing a charge of flux, a collector material, and a feedstock material including PGM's to a furnace;
forming a melt by heating the charge to at least 1350° C., the melt comprising a first layer of slag and a second layer of collector material associated with a majority of the PGM's from the feedstock material; and
impinging a plasma arc on a surface of slag layer so that a superheated puddle is formed on said surface whereby the mixing and formation of the second layer is accelerated.
The superheated puddle is a hot region at the surface of the slag layer where a plasma arc flame, typically at a temperature of about 5,000° to 10,000° C., contacts the slag surface when the source of the flame, a plasma torch, is positioned close to the surface but not so close as to cause premature failure of the plasma torch. The superheated puddle is preferably about 100° to 500° C. hotter than the melt. In the region of the superheated puddle, mixing action caused by both thermal flow, due to temperature gradients, and fluid flow, due to the force of the plasma flame striking the slag surface is believed to be responsible for the very rapid association of PGM's with the collector metal and rapid settling of the PGM's associated with the collector metal into the separate recoverable second layer.
The very rapid association and settling of PGM's and collector metals out of the slag into recoverable second layer enables a continuous process wherein feedstock material can be continually fed to a superheated puddle where PGM's are removed from the feedstock at rates neither possible nor expected with prior art systems.
In accordance with an embodiment of the present invention, a process for recovery of PGM's from chromite ores is described wherein, inter alia, a magnetic fraction resulting from wet high intensity magnetic separation is treated to recover platinum group metals which may be associated therewith. The process comprises the steps of: comminuting the chromite-bearing ore containing one or more platinum group metals associated therewith; subjecting the comminuted ore to single or multiple stage wet high intensity magnetic separation to form separate magnetic and nonmagnetic fractions wherein the nonmagnetic fraction contains a substantial portion of the platinum group metals contained in the ore; subjecting the magnetic fraction, which contains a substantial portion of the chromite contained in the ore, to gravity separation in a flowsheet incorporating comminution and reseparation of composite particles of chromite and gangue and subjecting the tailings to either comminution and flotation of the sulphides of iron and other magnetic sulphides with which the platinum group metals may be associated, or comminution and further gravity concentration of the platinum group metals particles, or subjecting the tailings to wet high intensity magnetic separation in order to separate residual chromite in the tailings from the nonmagnetics; adding these nonmagnetics to the nonmagnetics produced from the original ore; subjecting the combined nonmagnetics product or nonmagnetics from original ore to which has been added flotation or gravity concentrates produced from the aforesaid tailings resulting from gravity separation of the chromite magnetics to comminution and a flotation process to form a concentrate containing inter alia platinum group metals or compounds thereof; adding collector materials for the platinum group metals, activators to improve the collection efficiency and appropriate fluxes; and smelting these materials and concentrates in a high intensity heating furnace to form a slag layer and a layer consisting of the collector material, platinum group metals and nickel, copper and cobalt if they were present in the concentrates smelted in the furnace; removing the liquid slag and collector material together or separately from the furnace; separating the collector material layer from the slag layer and cooling the collector material and slag; separating the platinum group metals and nickel, copper and cobalt, if present, from the collector material by leaching it with a mineral acid followed by separation from the leach solution of nickel, copper and cobalt and also the collector material if it is economically justified, with the platinum group metals forming an insoluble residue or gel within the leaching vessel; separating and refining the individual platinum group metals from the residue or gel by well-known industrial methods; subjecting the slag comminution and separation of metal particles, if it is found that recovery of entrained particles is economically justified, and adding the metal particles to the collector materials, activators, fluxes and concentrates before smelting or else adding the metal particles to the leaching vessel used for separating the platinum group metals from the collector material and other metals present in the ore.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic flowsheet of an overall process of the present invention wherein platinum group metals and chromite are recovered from chromite bearing ore.
FIG. 2 is a schematic flowsheet of alternative methods of processing the slag from the high intensity heating furnace if this appears to be economically justified, i.e., leaching it together with the collector material or drying it and recycling it to the furnace for remelting.
FIG. 3 is a schematic flowsheet of a method used for processing of a South African chromite-bearing ore containing platinum group metals in order to produce chromite concentrates, residues containing platinum group metals and nickel, copper and cobalt as metals or compounds suitable for further purification processes. Three alternative methods for treatment of magnetic product after upgrading by spirals are indicated with the tailings being returned to different locations in the flowsheet.
FIG. 4 is a schematic flowsheet of the flotation upgrading system described in Example Two.
FIG. 5. is a schematic flowsheet of the spirals upgrading and wet high intensity magnetic separation described in Example 5.
FIG. 6 is a cross-sectional view of a plasma arc furnace adapted to practice of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, chromite bearing ore containing platinum group metals is mined at 1 by suitable methods and is comminuted at 2 to a sizing suitable for liberation of the chromite grains from gangue and additionally suitable for the magnetic separation which follows. For example, a South African ore was crushed and ground using a conventional ball mill circuit with recirculation of oversize particles to a sizing whereby substantially all of the particles of the ore were able to pass through a 60 mesh ASTM (250μ) screen. A typical sizing for the ground ore was as follows:
______________________________________Screen Sizing Sizing DistributionMesh ASTM Microns Weight % Passing______________________________________ 60 250 100100 150 77140 105 47200 74 34400 37 16______________________________________
The comminuted ore is then subjected to wet high intensity magnetic separation at 3 in order to separate the magnetic chromite particles from the nonmagnetic gangue particles which contain a substantial portion of the platinum group metals in the ore. In the wet high intensity magnetic separation process a thoroughly mixed slurry of the comminuted ore and water is subjected to a magnetic flux while the slurry is passing through a vessel containing metallic media such as grooved plates, steel wool or balls shaped to intensify the magnetic flux perpendicular to the flow direction of the slurry. The magnetic particles, chromite, are retained on the media and the nonmagnetic gangue particles pass through the vessel. Intermittently the flow of slurry to the vessel is stopped, the magnetic material adhering to the media is washed to remove entrained nonmagnetics and weakly magnetic particles and then the magnetic field is removed, permitting the magnetic particles to be washed from the media. The magnetic field is restored and the slurry is again passed through the vessel in the same series of steps. This intermittent cycle is conveniently automated by fabricating the vessels as annular segments of a ring which rotates continuously perpendicular to fixed electromagnets located around the periphery of the ring.
Depending upon the nature of the ore, one or more passes of magnetics or nonmagnetics through the magnetic field may be necessary to obtain high efficiency of separation. The wash water which contains weakly magnetic particles may be recirculated. For a South African ore, using slurry pulp densities of 10 to 30% solids by weight, two passes of nonmagnetics plus wash water were necessary as shown in 21 and 22 of FIG. 3 with different plate spacings for the first and second pass. In this case, the weight recovery of magnetics was between 75 and 80% with chromium recovery to magnetics of 95 to 97% by weight. The recovery of platinum group metals to nonmagnetics was 65 to 70% by weight.
The distribution of platinum group metals between the magnetics and nonmagnetics fraction is, to a large extent, dependent upon the mineralogy of the platinum group metals in the ore. For example, in a South African ore, about 10% of the platinum group metals particles were locked inside chromite particles and about 90% of the particles were located in the gangue, where they were found sometimes at chromite grain boundaries and often associated with nickel and copper sulphides. The platinum group metal particles may be magnetic, such as iron bearing platinum.
In order to obtain a higher recovery of platinum group metals from the ore, the magnetics product may be processed further by gravity separation methods at 4 in FIG. 1. It has been found advantageous when processing a South African ore to pass the magnetics product through a spirals gravity separation circuit consisting of a rougher stage at 23 in FIG. 3, one or more cleaner stages at 24 and a scavenger stage 26 for rougher and cleaner tails with a regrind stage at 25 before the scavenger. The scavenger concentrate returns to the rougher feed for reprocessing. The scavenger tails, which contain a considerable portion of the platinum group metals reporting to the magnetics product, may be further processed for concentration of platinum group metals by means of flotation, wet high intensity magnetic separation for removal of residual chromite particles, or by gravity methods such as tabling. In the case of wet high intensity magnetic separation, the tailings material may be added to the feed to the second stage of magnetic separation as shown in FIG. 3.
The nonmagnetic product from 3 in FIG. 1, together with nonmagnetics product from gravity concentration of magnetics product at 5 in FIG. 1, if that is the method used to upgrade the gravity tailings, contains a substantial portion of the platinum group metals present in the ore. This material is subjected to a flotation process 7 in FIG. 1, designed to separate sulphides from the gangue material, thus further concentrating the platinum group metals present as sulphides, or associated with sulphides of copper and nickel and iron.
Depending upon the degree of sub-division of the nonmagnetic product from the magnetic separator, it may be necessary to grind the nonmagnetic product at 6 before flotation in order to achieve rapid and efficient flotation. For a South African ore the optimum sizing for flotation was found to be such that about 80% of the particles pass through a 200 mesh ASTM (74μ) screen.
The flotation circuit may be any such circuit suitably designed and optimized for upgrading such materials, including subjecting the nonmagnetic fraction to a series of flotations in rougher, cleaner, recleaner and scavenger cell banks with the addition of suitable conditioners and pH modifiers such as copper sulphate, sulphuric acid, sodium hydroxide, frothers such as cresylic acid, Flotanol F, and collectors such as sodium isobutyl xanthate.
A typical flotation flowsheet is shown in FIG. 3. The subdivided nonmagnetic fraction is reground at grinding mill 27 in closed circuit with a particle size separation device such as a hydrocyclone, spiral screw classifier or screen, in order to achieve a particle size distribution adequate to liberate the sulphide and platinum group metals particles. The particles which are coarser than the desired sizing are returned to the feed and routed to the mill for regrinding.
It may be advantageous to deslime the slurry produced by the mill before sending it to flotation. A South African ore was deslimed at about 10 microns using hydrocyclones and thus enhanced the recovery of platinum group metals in subsequent flotation of the deslimed ore. Recovery of about 80% to 90% of platinum group metals in the deslimed ore was achieved by flotation. The slimes may contain a considerable portion of the platinum group metals in the nonmagnetics feed to the grinding mill 27. For a South African ore, about 18% of the ground ore was removed as minus 10 micron slimes and this slime contained about 15% of the platinum group metals in the feed to the desliming hydrocyclone. Consequently, the slime should be recovered for smelting by thickening and spray drying of the thickened slimes and blending it with flotation concentrates produced from the deslimed nonmagnetics.
The pulp density of the slurry of suitably sized particles is adjusted to a density suitable for effective mixing and conditioning of the particles with the flotation reagents, conditioners, frothers, collectors previously described and after further density adjustment to the optimum value for flotation it is subjected to flotation in the bank of rougher cells 29. The concentrate from this bank of cells is thereafter admitted to a bank of cleaner cells 30 for final concentration. The tailings material, which is depleted in content of platinum group metals, is densified and sent to a regrind mill 31 which may be operated in open circuit without particle size control, in order to liberate composite particles in which the platinum group metals, sulphides and gangue are intergrown. A typical sizing of product from the regrind mill is 100% less than 200 mesh ASTM (74μ).
The pulp density of the product from the regrind mill is adjusted to the optimum value for flotation and additional reagents, such as frothers and collectors, may be added before scavenger flotation at 32. The concentrate from the scavenger cells is sent to a bank of cleaner cells 33 for further upgrading. The tailings from the scavenger flotation cells is discharged to a tailings pond for recovery and recirculation of water.
The concentrate from cleaner cells 33 is sent to mix with the concentrate produced from rougher cells 29 before refloating in the cleaning flotation cells at 30. The tailings from cleaner cells 33 and cleaner cells 30 are sent to join the tailings from rougher cells 29 before regrinding at 31.
The final concentrate from cleaner flotation cells 30, which contains a substantial portion of the platinum group metals in the nonmagnetics fraction, is then filtered and dried at 34 before smelting at 8 in FIG. 1 and 35 in FIG. 3.
The purpose of smelting the flotation concentrates in the high intensity heating furnace 11, shown in FIG. 2, together with fluxes, collector material and activator, is to produce a metal layer comprised of platinum group metals and a collector or collectors therefor and a slag layer comprised of residual materials from the flotation concentrates, slimes and fluxes added to produce a fluid slag with a low melting point.
A preferred high intensity heating furnace is a plasma arc furnace, for example, using an expanded precessive plasma arc apparatus manufactured by Tetronics Research and Development Co. (see, for example, U.S. Pat. No. Re. 28,570 of Oct. 14, 1975). In such furnaces, one or more of such plasma devices are utilized to melt powdered feed materials containing platinum group metal concentrates and appropriate powdered collectors, fluxes and other reagents to obtain separate fluid slag and metallic layers which may be separately removed from the furnace.
An important feature of the present invention is the discovery that the process described herein is much less sensitive to the presence of chromite in the heating furnace than is the case with known smelting techniques for the extraction of platinum group metals from ores. In these techniques the presence of as little as 1.0% by weight of chromite in the concentrate fed to the submerged arc carbon electrode furnace, in the known method earlier described, can cause problems with recovery of platinum group metals. The process of the present invention can tolerate at least 7% chromite in the feed to the heating furnace without encountering such difficulties.
The construction of the high intensity heating furnace for use with PGM feedstock containing chromite should be such that uncontrolled amounts of carbon or carbonaceous materials do not come in contact with any chromite present in the feed to the furnace since the resultant ferrochrome which may form, as earlier noted, seriously impairs the recovery of platinum group metals. Thus either no carbon should be present in the furnace refractory lining or construction, or, if present, should be suitably protected against the possibility of contact with chromite at high temperatures above about 1100° C. This can be achieved, as shown in FIG. 6, by using suitable non-carbonaceous refractories for crucible 65 and extending the anode 71 to make contact with the collector metal layer 64.
The presence of a small amount of carbon or sulphur in the feed to the furnace has been found beneficial in obtaining good recovery of collector metal and platinum group metals. The effect of carbon or sulphur, termed activators, is to scavenge residual oxygen in the feed powders and ensure a neutral or slightly reducing atmosphere in the furnace. The amount of carbon or sulphur found useful for this purpose is between about 0.5 and 3.0% by dry weight of platinum group metal containing feedstock materials admitted to the furnaces.
In the process of the present invention, high intensity heating is performed in the presence of one or more metals which have been found to be efficient collectors for the platinum group metals. The term `collector material` as used herein includes copper, nickel, cobalt, and iron, metals or mixtures thereof or any other suitable metal to which platinum group metals will report during a smelting process as well as compounds that are reducible to collector metal under process conditions. Additionally, the collector material(s) should be chosen such that the eventual recovery of platinum group metals therefrom is not exceptionally difficult or uneconomical.
Some of the collector metals as noted above may also be admitted to the furnace in the form of their oxides or hydroxides or other compounds if they are suitable for reduction to metal in the furnace with reductants, e.g. carbonaceous material. Although the adverse effect of carbon on reduction of chromite in the smelting process has previously been described as an example of the process, careful control of the amount of reductant carbonaceous material, introduced with the feed may ensure that there is no carbonaceous material after the preferential reduction of the collector metal oxides, hydroxides, or other compounds.
Typically, the collector material will be present in an amount between about 3% to about 10% by dry weight of the platinum group metal-containing flotation concentrates and slimes admitted to the furnace. Similar quantities are useful with other feedstock materials. For a concentrate produced from a South African ore which contains about 5% chromite in the feed to the furnace, 3% copper or iron powder or 5% hematite iron ore fines with appropriate carbonaceous reductant may be used.
The collector metals may be introduced into the furnace either by mixing them with the feedstock prior to entry to the furnace or by separately melting these materials, either inside or outside the furnace, to provide a liquid layer thereof in the furnace prior to introduction of the feedstock.
Fluxes may also be added to the feedstock material to control or alter the viscosity, melting temperature and basicity of the resultant slag layer. It may be convenient in industrial practice to continuously feed platinum group metal containing feedstock materials to the furnace with added collector material and to gradually reduce the quantity of added collector material so that the collector material liquid layer in the furnace becomes continually enriched with platinum group metals to a concentration particularly suited for further treatment of collector material/PGM layer for recovery of platinum group metals.
Fluxes may also be added to the smelting furnace to control or alter the viscosity, melting temperature and basicity of the resultant slag layer. Suitable flux materials, for example, are lime and dolomite. A typical slag has a melting point in the range of about 1100° C. to about 300° C. In addition, other minerals may form, such as magnesio-chromite. It is important to obtain a low slag viscosity in order to achieve rapid mixing and efficient separation of the small particles of platinum group metals and collector metals.
Upon separation into fluid slag and metal layers within the high intensity heating furnace, the slag layer is tapped and further processed for disposal as shown in FIG. 2. Depending upon the efficiency and economics of the overall process, it may, in some instances be desirable to granulate at 11 and grind the slag at 13 then concentrate small particles of platinum group metals and collector material from slag by gravity separation techniques at 14 and remelt them with platinum group metal concentrates with appropriate collectors to recover the residual platinum group metals therein as shown in FIG. 2 or else send the particles to leaching 16 with the metallic layer from the furnace.
The metallic layer, containing the metal collector in association with the substantial portion of the platinum group metals, is then removed from the furnace and further processed to recover the platinum group metals or mixtures thereof. For example, in FIG. 3, the metal layer may be granulated at 36 and then subjected to acid leaching at 37 whereby the metal layer is dissolved in acids such as sulfuric, hydrochloric or mixtures thereof, and the platinum group metals precipitate and/or form colloids and are separated by filtration as an insoluble sludge.
Alternatively, the metallic layer from the furnace may be cast into plates and treated directly by electrolysis to remove collector material and leave a platinum group metal-containing sludge. In either case, the platinum group metal-containing sludge(s) from processing of the metallic layer are then treated in a known manner to recover either a single metal or metals or a mixture thereof.
FIG. 6 illustrates a plasma arc furnace adapted to practice of the present invention. In FIG. 6, a jet of ionised gas, i.e. plasma flame, flowing from the tip of the plasma torch 68 towards the slag layer impinges on the slag layer and superheats the slag at the impingement zone. The temperature of the plasma gas may be at about 5,000°-10,000° C. depending on the amount of entrainment of the surrounding furnace atmosphere which is at a temperature of about 1500°-2000° C. The position of the impinging flame is adjusted to cause a superheated puddle 75 at the surface of the molten slag layer 76. The formation and size of the super heated puddle 75 is dependent the upon plasma gas temperature, flowrate, pressure, and distance from the tip of the torch to the surface of the slag layer. The impingement of the plasma flame on the surface of the slag layer when properly adjusted for the process of the present invention causes a noticeable depression in the surface. The region of slag surrounding the puddle is subject to vigorous flow circulation pattern such as shown by the curved arrows 77 in FIG. 6, due to the very low viscosity of the slag in the high temperature flame impingement zone (superheated puddle) and the physical displacement of slag by the flame. In the embodiment shown, the precessive movement of the plasma torch causes the formation of a "doughnut" shaped zone of high temperature slag which is believed to be responsible for the very effective mixing which occurs in the slag layer. The depth of the slag layer is preferably selected so that the depth to diameter ratio is between about 1 to 5 and 1 to 10 and the residence time of the slag based on volumetric flow rate does not exceed 20 minutes. The very fine micron and sub-micron sized PGM particles in the feedstock are rapidly agglomerated by physical contact in the circulatory motion of the fluid slag in the puddle and rapidly associated with the collector material. The hitherto unexpected effectiveness of this "puddle circulation" effect is shown by PGM recoveries in collector material in the range of 90-95% which may be achieved in an average slag residence time less than about 20 minutes compared with several hours required for conventional submerged electric arc furnaces.
With reference to FIG. 6, the plasma arc smelting furnace consists of a circular steel shell made in several sections for convenience and lined with refractories 61 suitable for the high process temperatures and having good chemical resistance to attack by the slag, fluxes and feedstock, e.g. high alumina refractories. At the slag layer zone, a water cooled panel 62 is used to form a frozen layer of slag on the refractory lining 61 to protect it from attack by the slag. A water-cooled slag overflow spout 63 permits the slag to leave the furnace continuously after flowing in close proximity to the PGM-collector material layer 64. The PGM collector metal layer accumulates in an electrically conductive crucible 65 e.g. manufactured from graphite. The collector metal associated with PGM's is tapped intermittently from the furnace through taphole 66. The plasma arc torch 67 shown in FIG. 6 is of the variable length expanded precessive arc type manufactured by Tetronics Research and Development Co., Ltd. described above. This plasma torch is precessed about bearing 68 by motor 69 and describes a cone of revolution. The distance from the lower tip of the torch to the surface of the slag layer and the angle of precession from the vertical axis of the furnace can both be adjusted. The rate of movement of the plasma arc across the slag surface is selected to give a substantially uniform puddle temperature and is typically about 500 to 1500 feet per minute. For example, in a plasma arc furnace where the length of the plasma flame (distance between the plasma torch and slag surface) is about 10-20 inches and the angle of the flame precession is up to about 10° from vertical the preferred rate of movement for the flame on the slag surface is about 1000 feet per minute. Electricity is supplied to the torch through cable 70 and the anode 71 is connected to the crucible 65 and cable 72 back to a power supply. Feedstock material enters the furnace through several feed tubes 73 (others omitted for clarity) and waste gases leave the furnace through exhaust port 74. In certain instances, it is desirable to position feed tubes 73 so as to direct the feedstock material directly into the plasma arc for rapid melting thereof. It will be appreciated by those skilled in the art that the process described in the foregoing paragraph is equivalent to that described in connection with FIGS. 1, 2 and 3 except that the feed enters the process at the steps identified by reference numerals 8, 11, and 35, respectively in those Figures.
The process of the present invention is further illustrated by the following non-limiting examples.
EXAMPLE ONE
Chromite-bearing ore containing approximately 5 grams per tonne of platinum group metals was comminuted, and subjected to wet high intensity magnetic separation using a Jones Ferromagnetics Separator with two passes of nonmagnetics. Assays for platinum and palladium are presented as these represent approximately 50% and 25% respectively of the platinum group metal content of the particular ore.
______________________________________ Assays wt Cr.sub.2 O.sub.3 Pt Pd Recoveries %Product % % g/t g/t Cr.sub.2 O.sub.3 Pt Pd______________________________________magnetics pass 1 62.2 39.27 1.1 0.5 80.3 21.9 20.4magnetics pass 2 14.1 33.27 2.7 1.2 15.4 12.2 11.1magnetics 1 + 2nonmagnetics pass 2 76.3 38.17 1.4 0.6 95.7 34.1 31.5pass 2 23.7 5.47 8.7 4.4 4.3 65.9 68.5calc. head assay 100.0 30.41 3.1 1.5 --actual head assay -- 30.70 3.1 1.6 --______________________________________
The slurry pulp density was 30% solids (wt.) to the first pass and 20% solids (wt.) to the second pass. The magnetic field strength was 1.0 tesla for both passes.
EXAMPLE TWO
Nonmagnetics produced by wet high intensity magnetic separation were processed in a pilot flotation plant according to the flowsheet shown in FIG. 4. The feed ore was deslimed at 39 at 10 microns and the deslimed ore was ground at 40 to 80% minus 200 mesh ASTM using a classifier at 41 consisting of a hydrocyclone and screen in closed circuit with the mill. The ground ore was adjusted to a pulp density of approximately 50% solids and conditioner reagents were added to three stirred conditioner tanks, 42, in series. The conditioning times were 10 minutes with 100 grams per ton of copper sulphate (hydrated basis), 4 minutes with 100 grams per ton of sodium isobutyl xanthate. The conditioned pulp was diluted to 30% solids by weight at a pH of 8.5 and was sent to rougher flotation cells 43 for 15 minutes of flotation. The concentrates from rougher flotation were sent to cleaner flotation cells 44 for 10 minutes of flotation. The tailings from the rougher flotation were sent to scavenger flotation cells 45 for 25 minutes of flotation and the tailings from scavenger flotation were discharged as waste. The concentrates from scavenger flotation were sent to a regrind mill 46 together with tailings from the cleaner flotation cells 47 for 10 minutes flotation. The concentrates from cleaner flotation cells 47 were sent to comingle with the concentrates from rougher flotation cells 43 before being sent to cleaner flotation cells 44. The tailings from cleaner flotation cells 47 were sent to comingle with the tailings from rougher flotation cells 43 before being sent to the scavenger flotation cells 45. The concentrates from cleaner flotation cells 44 were final concentrates and were filtered and dried before mixing with the slimes produced from desliming hydrocyclone 39.
______________________________________ Assays Distribution %Product wt % Pt g/t Pd g/t Pt Pd______________________________________DESLIMING HYDROCYCLONEunderflow 82.3 8.9 4.1 85.2 84.5overflow 17.7 7.2 3.5 14.8 15.5head 100.0 8.6 4.0 100.0 100.0FLOTATION OF DESLIMED NONMAGNETICSconcentrates 14.5 47.0 23.9 79.2 80.2tailings 85.5 2.1 1.0 20.8 19.8calc. head 100.0 8.6 4.3 100.0 100.0assayed feed 8.8 4.2______________________________________
EXAMPLE THREE p Flotation concentrates containing 32 grams/ton platinum, 17.5 grams/ton palladium and 7.8% Cr 2 O 3 were mixed with lime, copper powder and carbon in the weight proportions 72/19/7.5/1.5 and heated in a high intensity gas fired furnace at 1500° C. A metal phase was separated from a slag phase and the weight distribution and assays of the products were as follows:
______________________________________ Assays Distribution %Product wt % Pt g/tonne Pd g/tonne Pt Pd______________________________________metal 2.77 260 115 46.0 45.0slag 97.23 8.7 4.0 54.0 55.0calc. head 100.00 15.7 7.1 100.0 100.0______________________________________
EXAMPLE FOUR
Flotation concentrates containing 32 grams/ton platinum, 17.5 grams/ton palladium and 7.8% Cr 2 O 3 were mixed with lime, ferric oxide and carbon in the weight proportions 74/20/4/2 and heated in a high intensity gas fired furnace at 1500° C. A metal phase was separated from a slag phase and the weight distribution and assays of the products were as follows:
______________________________________ Assays Distribution %Product wt % Pt g/tonne Pd g/tonne Pt Pd______________________________________metal 1.27 432 209 48.5 32.5slag 98.73 5.9 5.6 51.5 67.5calc. head 100.00 21.3 15.4 100.0 100.0______________________________________
EXAMPLE FIVE
Magnetics produced by wet high intensity magnetic separation of a South African ore in a pilot plant were processed on a batch basis by spirals and wet high intensity magnetic separator according to the flowsheet shown in FIG. 5. The magnetics product was fed to Rougher Spiral 48 at a feedrate of 1.2 tons per hour and about 35% solids by weight and the concentrates were fed to the Cleaner Spiral 49 to produce two products, concentrates and tailings. The mass and assay balances for the Rougher and Cleaner Spirals are as follows:
______________________________________Assayswt Cr.sub.2 O.sub.3 Pt g/ Pd g/ Recoveries %Product % % tonne tonne Cr.sub.2 O.sub.3 Pt Pd______________________________________ROUGHER SPIRALconcentrate 76.4 40.49 0.6 0.3 82.1 43.7 44.7tailings 23.6 28.59 2.5 1.2 17.9 56.3 55.3calculated 100.0 37.68 1.05 0.51 100.0 100.0 100.0headassayed 37.65 1.4 0.5headCLEANER SPIRALconcentrate 89.1 41.97 0.6 0.3 92.0 66.2 69.0tailings 10.9 29.71 2.5 1.1 8.0 33.8 31.0calculated 100.0 40.63 0.81 0.39 100.0 100.0 100.0headassayed 40.49 0.6 0.3head______________________________________
In FIG. 3, the tailings from the Cleaner Spiral are comingled with the tailings from the Rougher Spiral and reground at 25 before separation on the scavenger Spiral. The assays tabulated above can be combined to indicate the grade and recovery of the chromite concentrate and the feed to the Scavenger Spiral 26 in FIG. 3.
______________________________________ROUGHER - CLEANER SPIRALAssayswt Cr.sub.2 O.sub.3 Pt g/ Pd g/ Recoveries %Product % % tonne tonne Cr.sub.2 O.sub.3 Pt Pd______________________________________concentrate 68.1 41.97 0.6 0.3 75.6 33.9 35.3tailings 31.9 28.88 2.5 1.2 24.4 66.1 64.7calculated 100.0 37.79 1.2 0.6 100.0 100.0 100.0headassayed 37.65 1.4 0.5head______________________________________
The tailings produced for Rougher Spiral 48 in FIG. 5 was fed to a Scavenger Spiral 50 without regrind and the mass and assays of the products are tabled below.
______________________________________SCAVENGER SPIRALSAssayswt Cr.sub.2 O.sub.3 Pt g/ Pd g/ Recoveries %Product % % tonne tonne Cr.sub.2 O.sub.3 Pt Pd______________________________________concentrate 49.2 25.83 2.6 1.2 44.8 50.2 49.2tailings 50.8 30.84 2.5 1.2 55.2 49.8 50.8calculated 100.0 28.38 2.5 1.2 100.0 100.0 100.0headassayed 28.59 2.5 1.2head______________________________________
These results show that regrind of the scavenger feed is essential for liberation of chromite and platinum group metals from composite particles.
The two products from the Scavenger Spiral 50 were subjected to laboratory scale wet high intensity magnetic separation at a field strength of 1.5 tesla. The effect of regrinding was tested by grinding the spirals concentrate to 100% minus 80 microns and the spirals tailings was separated at the same conditions but without regrinding.
______________________________________Assayswt Cr.sub.2 O.sub.3 Pt g/ Pd g/ Recoveries %Product % % tonne tonne Cr.sub.2 O.sub.3 Pt Pd______________________________________SCAVENGER SPIRALS CONCENTRATESAFTER REGRINDmagnetic 66.3 35.35 1.1 0.6 82.6 27.7 32.7middlings 3.0 12.91 6.0 2.7 1.4 6.8 6.7tailings 30.7 14.85 5.6 2.4 16.1 65.4 60.6calculated 100.0 28.38 2.6 1.2 100.0 100.0 100.0headSCAVENGER SPIRALS CONCENTRATESWITHOUT REGRINDmagnetic 71.1 34.96 2.0 0.9 81.2 48.3 47.4middlings 3.5 21.55 n.a* n.a* 2.5 -- --tailings 25.4 19.71 6.0 2.8 16.4 51.7 52.6calculated 100.0 30.62 3.6 1.4 100.0 100.0 100.0head______________________________________ *n.a. insufficient sample for assay
From these results, the advantages of regrinding the feed to the Scavenger Spiral may be clearly seen. In addition, it may be seen that additional recovery of chromite and platinum group metals is possible by processing the scavenger products by wet high intensity magnetic separation as shown at 22 in FIG. 3.
EXAMPLE SIX
Flotation concentrates containing 55 grams/ton platinum and 28 grams/ton palladium and 5.9% Cr 2 O 3 were mixed with lime, copper powder and charred coal containing 70% fixed carbon in weight proportions 70/25/2/3. The mixture was fed into a plasma arc furnace which contained a molten layer of 20 kilograms of copper metal. The furnace temperature was maintained at 1500°-1600° C. during the feeding of the mixture by controlling the electrical energy input and feedrate. At the conclusion of feeding 80 kilograms of the mixture the furnace was maintained at a temperature of 1550°-1650° C. for 30 minutes and then the slag and metal in the furnace were poured into ladles. After cooling the copper metal was separated from the slag and the platinum group metal was separated from the copper.
__________________________________________________________________________Component Mass Balancewt Pt dist. Pd dist Cr dist.kg. g/tonne grams % g/tonne grams % % kg. %__________________________________________________________________________feed 80.0 27.7 2.2160 -- 12.9 1.0320 -- 2.07 1.6560 --metal 21.5 108 2.3220 97.7 46.0 0.9890 97.3 0.02 0.0043 0.2slag 69.3 0.8 0.0554 2.3 0.4 0.0277 2.7 2.57 1.7810 99.8 2.3774 1.0167 1.7853Accountability 107.3% 98.5% 107.8%__________________________________________________________________________
EXAMPLE 7
A plasma arc furnace having a shell diameter of 1.5 meters, and a 1.0 meter internal diameter, and equipped with a variable length exanded precessive plasma arc torch was used to process 21.5 tons of alumina pellets, containing about 380 g/tone on platinum and 200 g/ton on palladium, for recovery of the platinum group metals in an iron collector metal layer. Lime was used as a flux and iron oxide (millscale) and carbon (coal) were added to the feed mixture to generate iron collector metal to supplement the initial layer of 45 kg. of molten cast iron and to maintain a reducing atmosphere inside the furnace. During the test approximately 350 kg. of the refractory lining of the furnace was dissolved by slag attack. The components in the feed were blended in a ribbon blender prior to introduction to the furnace through four feedholes in the furnace roof equally spaced around the plasma torch so that the feedstock dropped into the vicinity of a doughnut shaped superheated puddle of slag produced by the impingement of the ionized argon gas plasma flame on the surface of the slag layer. The proportions of components in the feed mixture were as follows:
______________________________________ pellets 48.7 lime 48.7 iron oxide 0.2 coal 2.4 100.0______________________________________
The feed mixture was processed at a feed rate averaging about 700 kg/hour and at rates up to 1000 kg/hour with an average slag layer temperature of about 1400° C. The temperature of the superheated slag in the superheated puddle was not measured but the extremely fluid condition in the puddle could be observed through an observation port in the side of the furnace. The slag continuously overflowed from the furnace during the test. Regular samples of slag were automatically collected from the slag stream discharging from the furnace for assay purposes. The waste gas from the furnace passed through a solids dropout chamber and a combustion chamber was provided for CO and H 2 gases evolved from the coal and oxide reduction reactions in the furnace, baghouse and, exhaust fan, and stack. The dropout material and baghouse dust were collected and sampled for assay. The waste gas was assayed on an intermittent basis. Zircon sand (20 kg.) was used in several experiments as a tracer material to determine the residence time of slag in the furnace. The peak in zirconia content of the slag occurred 5- 6 minutes after injection into the feed holes indicating a very short residence time for the majority of the slag. At the conclusion of the test the collector metal taphole was opened and the metal and slag remaining in the furnace were removed, sampled and assayed. Typical assays (wt %) of the feed materials and products are tabled below.
______________________________________ Feed Slag Baghouse Dropout Mix % Product % Dust % Material %______________________________________SiO.sub.2 0.4 0.6 0.5 0.8Al.sub.2 O.sub.3 48.1 47.10 3.2 22.8MgO 0.3 0.4 0.2 0.3CaO 46.6 51.1 20.0 72.2Fe.sub.2 O.sub.3 0.3 0.3 0.4 0.6PbO 2.8 <0.01 68.6 2.0Loss on 9.0 (1.1) 0.3 2.4IgnitionPt 0.0484* 0.0011 0.013 0.0150Pd 0.0188* 0.0004 0.0211 0.0104______________________________________Collector Metal %C Si Cr Ni Cu Fe Pt Pd______________________________________3.7 0.08 7.8 0.5 0.6 76.3 3.87 1.42______________________________________ *Assay of catalyst in the feed mix.
The PGM and other major component material balances for the test were as follows:
______________________________________InputsPGM Other Components______________________________________Pt 7.99 kg Al.sub.2 O.sub.3 17,773 kgPd 4.20 CaO 20,331Total 12.19______________________________________Outputs Baghouse Refrac-Slag Dust Dropout Material tory Metal Total______________________________________PGMPt 0.410 0.226 0.0985 0.0874 6.76 7.58Pd 0.156 0.340 0.0794 0.0305 2.46 3.06Total 0.566 0.566 0.1799 0.1179 9.22 10.64Other ComponentsAl.sub.2 O.sub.3 17,930 59 116 203 -- 18,308CaO 19,021 323 455 288 -- 20,087______________________________________Overall Balance Output Input Out-in Accountability %______________________________________Pt 7.58 7.99 (0.41) 94.9Pd 3.06 4.20 (1.14) 72.9Total 10.64 12.19 (1.55) 87.3Al.sub.2 O.sub.3 18,308 17,773 535 103.0CaO 20,087 20,331 (244) 98.8______________________________________
The recoveries of PGM in various test products were as follows:
______________________________________ Basis: Input OutputProduct Pt Pd Pt Pd______________________________________slag 5.1 3.7 5.4 5.1baghouse dust 2.8 8.1 3.0 11.0dropout material 1.2 1.9 1.3 2.6refractory 1.1 0.7 1.1 1.0metal 84.6 58.6 89.2 80.3 94.8 73.0 100.0 100.0______________________________________
The PGM in the dropout material and refractory may be recycled to the furnace in commercial practice if desired. Also, the PGM in the baghouse dust may be recovered by conventional precious metal lead blast furnace practice. It is believed that the reasons for the high palladium losses to the baghouse dust was oxidation in the furnace due to excess oxygen. | A process for separating platinum group metals (PGM's) from various feedstock materials, is disclosed, wherein a plasma arc flame is employed to produce a superheated puddle on the surface of a slag layer to accelerate the association of platinum group metals with a collector material and formation of a recoverable layer of platinum group metals and collector material. | 1 |
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