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This application is a Divisional of U.S. patent application Ser. No. 11/105,416 filed Apr. 14, 2005, now U.S. Pat. No. 7,168,568 which is a Divisional of U.S. patent application Ser. No. 09/985,952, filed Nov. 6, 2001, now U.S. Pat. No. 6,899,230, issued May 31, 2005, and claims the benefit of U.S. Provisional Application No. 60/249,466, filed Nov. 20, 2000, which are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for isolating valuable or toxic substances from a source containing such materials.
It is well known that precious metals and toxic substances can be contained in small amounts in a composite material that may include a mixture of soil, rocks, ores, metals, minerals, tailings, and the like. In the instance of precious metals, the amount of precious metals in a volume of composite materials may be quite small, but the volume of composite materials may be very large. If the precious metals can be extracted to a high degree, substantial and valuable amounts of precious metals can be obtained. Similarly, in the case of toxic substances, their presence in even lower, trace amounts in composite materials can present a similar environmental or human hazard. If not extracted from the large volumes of composite materials, it becomes necessary to dispose of all of the composite materials, which is very costly and greatly impacts the environment. If the toxic substances could be extracted and disposed of separately, the cost of disposal and the environmental problem are greatly reduced.
While extraction devices and processes have been known in the past, frequently they have produced large amounts of polluted water or required special handling in order to perform extraction. This has significantly raised the cost of separation attempts and frequently made it financially unjustifiable to process the large volumes of composite materials in order to extract precious metals or toxic substances. Also, the prior art extraction devices and processes were inefficient resulting in incomplete extraction of precious metals or toxic substances. Accordingly, there is a need for a more efficient extraction method and apparatus as well as a method and apparatus that can be easily transferred and employed at the location of the composite material.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel apparatus and method for isolating to a high degree valuable or toxic substances from composite materials containing such valuable or toxic substances in low concentration.
Another object of the present invention is to provide a novel apparatus and method for separating non-magnetic mineral values from a source of composite materials containing magnetic material and non-magnetic material.
A still another object of the present invention is to provide a novel method of dry separation of non-magnetic metal values from a source of material containing the non-magnetic values and other minerals.
A further object of the present invention is to provide an environmentally friendly toxic substance separation apparatus and method.
Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and obtained by the structure and methods particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention provides, in one aspect, an apparatus for separating non-magnetic mineral values from a source material containing magnetic material and non-magnetic material, the apparatus including a first endless conveyer having a front end and a rear end, the first endless conveyer having a textured surface and having a plurality of spaced apart paddles removably mounted thereon; a second endless converyer positioned beneath the first conveyer in a vertically spaced relationship therewith and having a front end and a rear end, the front end of the second conveyer positioned rearward with respect to the front end of the first conveyer to define a longitudinally staggered relationship between the first conveyer and the second conveyer, the second endless conveyer being configured to receive the source material adjacent its rear end; a motor for driving the first conveyer in a first direction and the second conveyer in a second direction opposite to the first direction such that a bottom surface of the first endless conveyer and a top surface of the second endless conveyer are driven in substantially the same direction from the respective rear ends towards the respective front ends; a first wall and a second wall extending between the first conveyer and the second conveyer substantially along the entire length of each conveyer, the first and second walls, the bottom surface of the first endless conveyer, the top surface of the first endless conveyer, and the paddles collectively forming an enclosure within which the source material is positioned; and a magnetic separation assembly mounted within the first endless conveyer for acting on the source material within the enclosure, the assembly having a frame for supporting discrete sections of magnets, the sections of magnets being mounted to the frame in spaced longitudinal relation to form alternating areas of presence and absence of a magnetic field such that the magnetic separation assembly permits the magnetic fields to intermittently act on the source material to progressively separate the magnetic material from the non-magnetic material as the material is transported along the second endless conveyer within the enclosure.
In another aspect, the present invention provides an apparatus for separating non-magnetic mineral values from a source material containing magnetic material and non-magnetic material, the apparatus including a frame; a non-magnetic material collection channel mounted to the frame for collecting non-magnetic material; a feed mechanism for supplying the source material to the collection channel; retaining members mounted within the collection channel to retain the collected non-magnetic material; a fluid connection on the collection channel configured to connect a source of fluid to the collection channel, the fluid transporting the source material fed from the feed mechanism along the retaining members for retaining non-magnetic material and flushing the magnetic material contained in the source material away from the retaining members; and a magnetic separation assembly mounted adjacent the collection channel for exerting magnetic fields on the source material transported by the fluid to attract the magnetic material in the source material away from the retaining members and to assist collection and retaining of the non-magnetic material in the retaining members.
In another aspect, the present invention provides a method of dry separation of non-magnetic metal values from a source material containing the non-magnetic values and other minerals, the method including the steps of providing a plurality of spaced apart magnets each for generating a magnetic field directed to an underlying conveyer; exposing the material on the conveyer to each of the magnetic fields in alternation in a continuous manner as the material is advanced by the conveyer; forming substantially homogeneous strata of the minerals overlying said non-magnetic values by repeated exposure to magnetic fields followed by the absence of the fields; and isolating the strata.
In another aspect, the present invention provides a method of dry separation of non-magnetic metal values from a source material containing the non-magnetic values and other minerals, the method including the steps of providing a pair of top and bottom endless conveyers in vertical spaced relation to convey the source material, the top conveyer including a plurality of spaced apart magnets each generating a magnetic field directed to the bottom conveyer; exposing the material on the bottom conveyer to each of the magnetic fields in alternation in a continuous manner as the material is advanced by the bottom conveyer; forming substantially homogeneous strata of the minerals overlying said non-magnetic values by repeated exposure to magnetic fields followed by the absence of the fields; and isolating the strata.
In another aspect, the present invention provides a method of wet separation of non-magnetic metal values from a source material containing non-magnetic material and magnetic material, the method including the steps of providing a non-magnetic material collection channel for collecting non-magnetic material; feeding the source material to the collection channel; treating the source material with a fluid in the collection channel to transport the source material along a retaining member for retaining non-magnetic material, the fluid flushing materials other than the non-magnetic metal values away from the retaining member; and providing a magnetic separation assembly adjacent the collection channel, the assembly having discrete sections of magnets, the sections of magnets in spaced longitudinal relation forming alternating areas of presence and absence of a magnetic field for permitting the magnetic fields to intermittently act on the source material to progressively separate the magnetic material from the non-magnetic material during transportation along the retaining member, the non-magnetic material carried by the fluid being efficiently collected and retained in the retaining member in the absence of magnetic material.
In another aspect, the present invention provides a mineral separation assembly suitable for separating metal values from a source of material containing non-magnetic values and other minerals, the assembly including a frame for supporting discrete sections of magnets, the sections of magnets being mounted to the frame in spaced longitudinal relation forming alternating areas of presence and absence of a magnetic field; a spacer mechanism for spacing and maintaining the magnets within an individual section; a magnetic shield for shielding the frame from magnetic fields generated from the magnets; and directing means for directing magnetic fields in each section of the sections in a coaxial relationship such that, upon interaction with the assembly, the magnetic fields intermittently act on the source material to progressively separate the magnetic material from the non-magnetic material to assist collection and retainment of the non-magnetic material in a retainer.
In another aspect, the present invention provides a separation apparatus for separating a target material from a source material, the apparatus including a carrier for transporting the source material along a predetermined path; and a magnetic field generator including a plurality of magnets for forming alternating areas of presence and absence of a magnetic field along the predetermined path so that the magnetic fields intermittently act on the source material transported by the carrier to progressively separate the target material from the source material, the strength of the magnetic fields being such that not only magnetic materials in the source material are affected as being attracted, but also conductive non-magnetic materials in the source material are affected by virtue of induction, causing repulsion of the conductive non-magnetic materials away from the magnetic field.
In another aspect, the present invention provides a method for separating a target material from a source material, the method including the steps of transporting the source material along a predetermined path; and forming alternating areas of the presence and absence of a magnetic field along the predetermined path so that the magnetic fields intermittently act on the source material transported along the predetermined path to progressively separate the target material from the source material, the strength of magnetic fields being such that not only magnetic materials in the source material are affected as being attracted, but also conductive non-magnetic materials in the source material are affected by virtue of induction, causing effective repulsion of the conductive non-magnetic materials away from the magnetic field.
In another aspect, the present invention provides a method for separating and disposing of a toxic substance from a source material in an environmentally. clean manner, the method including the steps of receiving the source material including the toxic substance; transporting the source material along a predetermined path; forming alternating areas of presence and absence of a magnetic field along the predetermined path to exert the magnetic fields intermittently on the source material that is being transported along the predetermined path to progressively separate the toxic substance from the source material, the strength of magnetic fields being such that not only magnetic materials in the source material are affected as being attracted, but also conductive non-magnetic materials in the source material are affected by virtue of induction, causing effective repulsion of the conductive non-magnetic materials away from the magnetic field; and collecting the toxic substance separated in the step of forming.
In another aspect, the present invention provides an apparatus for separating non-magnetic substances from a source material containing magnetic material and non-magnetic material, including a plurality of magnetic separating stations longitudinally spaced apart to provide alternating areas of a strong magnetic field and the absence of a strong magnetic field; a conveyer for moving the source material beneath the magnetic separating stations such that at a magnetic separating station magnetic material within the source material is attracted away form the conveyer to the magnetic station and non-magnetic material is not attracted to the magnetic station and remains on the conveyer, the conveyer having a discharge end; a scraper for periodically separating the magnetic material from each of the magnetic stations such that the magnetic material falls onto the conveyer to form a layer of the magnetic material in areas of the conveyer transporting the non-magnetic material thereon, wherein each downstream magnetic separating station acts on the source material on the conveyer to further separate the magnetic material from the non-magnetic material; a non-magnetic material receptacle located proximate the discharge end and a magnetic material receptacle located proximate the discharge end; and a discharge separating device located proximate the discharge end to cause substantially only the separated non-magnetic material to be discharged into the non-magnetic material receptacle and substantially only the separated magnetic material to be discharged into the magnetic material receptacle.
In a further aspect, the present invention provides a method for separating non-magnetic substances from a source material containing magnetic material and non-magnetic material, the method including the steps of providing alternating areas of a strong magnetic field and the absence of a strong magnetic field via a plurality of magnetic separating stations longitudinally spaced apart; moving the source material via a conveyer located beneath the magnetic separating stations such that at a magnetic separating station magnetic material within the source material is attracted away form the conveyer to the magnetic station and non-magnetic material is not attracted to the magnetic station and remains on the conveyer; periodically scraping and separating the magnetic material from each of the magnetic stations such that the magnetic material falls onto the conveyer to form a layer of the magnetic material in areas of the conveyer transporting the non-magnetic material thereon, wherein each downstream magnetic separating station acts on the source material on the conveyer to further separate the magnetic material from the non-magnetic material; discharging substantially only the separated non-magnetic material into a non-magnetic material receptacle and discharging substantially only the separated magnetic material into a magnetic material receptacle.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further. understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a side view of a dry magnetic separating apparatus according to an embodiment of the present invention;
FIGS. 2A , 2 B, 2 C, and 2 D are enlarged drawings of the areas 2 A, 2 B, 2 C, and 2 D, respectively, shown in FIG. 1 ;
FIG. 3A is an enlarged schematic view of the area 3 A of FIG. 1 ;
FIG. 3B is an enlarged schematic view of the area 3 B of FIG. 1 ;
FIG. 3C is an enlarged schematic view of the area 3 C of FIG. 1 ;
FIG. 4 is a perspective view of a wet magnetic separating apparatus according to an embodiment of the present invention;
FIG. 5 is an enlarged view of a portion of the apparatus of FIG. 4 ;
FIG. 6 is a side view of the apparatus of FIG. 5 ;
FIG. 7 is an enlarged view of a portion of a mesh belt used in the wet separating apparatus of FIG. 4 ; and
FIG. 8 is an end view of the apparatus of FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
With reference to FIG. 1 , a first endless conveyer belt 11 is shown to be vertically disposed with respect to a second endless conveyer belt 13 . This is a preferred disposition of the first endless conveyer belt 11 with respect to the second endless conveyer belt 13 . The first endless conveyer belt 11 has a first end 35 (front end) and a second end 37 (rear end) and is moved by a conventional motor (not shown) in a first direction, for example a clockwise direction, as shown by the arrow 33 . The rear end 39 of the second conveyer receives composite material (source material) in this preferred embodiment. Side walls 42 are provided in either side of the conveyers such that walls 42 , the bottom surface of the first endless conveyer belt 11 , and the top surface of the second endless conveyer belt 13 together form an enclosure within which the source material is located. While side wall 42 is depicted as transparent in FIG. 1 to show the interior, of course, an opaque side wall 42 may also be employed.
As used herein, the composite material is intended to include a mixture of dirt, ores, rock, tailings, and/or other material that includes both magnetic material, such as ferrous metals and minerals, and non-magnetic material, such as non-ferrous metals and minerals. In some instances, the composite material may include toxic minerals or metals in trace amounts per unit volume.
In this example, the composite material is discharged to the rear end 39 of the second endless conveyer belt 13 . If desired, the composite material may instead be loaded onto the top surface of the first endless conveyer 11 at its first end 35 and discharged from the second end 37 of the first endless conveyer belt 11 to the rear end 39 of the second endless conveyer belt 13 . Also, depending upon design choice, the composition material may be loaded anywhere on the top surface of the first endless conveyer 11 .
The second endless conveyer belt 13 includes a second end 41 (front end) and is moved by a suitable motor (not shown) in a second direction shown by the arrow 33 , for example, a counterclockwise direction. As shown in FIG. 1 , the path of the second endless conveyer belt 13 is substantially aligned with the path of the first endless conveyer belt 11 . Moreover, in this preferred embodiment, the first endless conveyer built 11 moves at a higher speed, for example 30 rpm, 40 rpm, etc., than the speed of the second endless conveyer belt 13 , for example 10 rpm.
A series of magnets 15 , 17 , 19 , 21 , and 23 (including magnets 23 a and 23 b ) are provided in a space defined by the first endless conveyer belt 11 . These magnets are commercially available, strong magnets having magnetic Gauss Oersteds (MGO e ) of 27 or higher. In this example, the front end side of magnets 23 a and 23 b are provided to increase the magnetic field strength to ensure effective attraction of the magnetic materials from the source.
Preferably, at least the surface of the first endless conveyer belt 11 in contact with the composite material has a textured surface. Similarly, the surface of the second endless conveyer belt 13 may have a textured surface. The composite material is discharged at the rear end 39 of the second endless conveyer belt 13 . As the composite material moves from the first (rear) end 39 toward the second (front) end 41 of the second endless conveyer belt 13 , the material passes underneath the magnets 15 , 17 , 19 , 21 , 23 a and 23 b and is subjected to the strong magnetic fields of these magnets. As the composite material passes underneath these magnets, magnetic materials, such as ferrous metals and minerals, are attracted to the magnets, and non-magnetic material, such as non-ferrous metals and minerals, are not attracted and remain on the second endless conveyer belt 13 . The magnets are of such strength that the magnetic metals and minerals attracted thereto remain proximate the magnets despite the continuing movement of the first endless conveyer belt 11 . Thus, the textured surface of the first endless conveyer belt 11 slides between the magnets and the materials attracted to the magnets because the materials attracted to the magnets remain proximate thereto until they are scraped in the direction of the movement of the first endless conveyer belt 11 by one of the paddles 25 .
The non-magnetic materials, for example non-ferrous metals and minerals, remain on the second endless conveyer belt 13 and continue to move in the direction of the arrow 33 . As the first endless conveyer belt rotates, paddles 25 will be intermittently moved past the locations of the magnets. The magnetic materials attracted to the magnets are pushed by the paddles 25 away from the magnets and out of the magnetic fields of the magnets. As the magnetic materials are pushed by the paddles 25 , they fall back to the surface of the second endless conveyer belt 13 on top of the non-magnetic materials that had remained on the second endless conveyer belt 13 . As a consequence, the magnetic materials form a layer on top of the non-magnetic materials that were not attracted to the magnets. In this way, as the composite material traverses the second endless conveyer belt from the first end 39 to the second end 41 , the composite materials become stratified with the magnetic materials being layered on top of the non-magnetic materials residing on the surface of the second endless conveyer belt 13 .
The stratification of the composite material is illustrated in FIGS. 2A through 2D . FIG. 2A corresponds to the area 2 A identified in FIG. 1 . FIG. 2A schematically shows the composite materials before passing into the magnetic field of the first magnetic 15 . FIG. 2B is an enlarged view of the area 2 B of FIG. 1 . FIG. 2B schematically illustrates the magnetic materials, such as the ferrous metals and minerals, being attracted to the magnet 17 with the non-magnetic materials, such as non-ferrous metals and minerals, remaining on the surface of the second endless conveyer belt 13 . FIG. 2C is an enlarged view of the area 2 C of FIG. 1 . FIG. 2C schematically illustrates the stratification of the composite materials. The upper layers of the composite materials comprises magnetic materials and the lower layers of the composite materials comprises non-magnetic materials. FIG. 2D is an enlarged view of the area 2 D shown in FIG. 1 . FIG. 2D further illustrates the stratification of the composite materials as a result of passing by the magnets 15 , 17 , 19 , and 21 .
It can be understood that the number of magnets provided within the first endless conveyer belt is a matter of design choice. The distance between the magnets is also a matter of design choice depending upon the strengths and sizes of the magnets provided. The proper distance between the magnets is maintained by a structure sufficiently strong to support the magnets. Further, if it is desirable to have a larger intensity of the magnetic fields at the surface of the second endless conveyer belt 13 due to the nature of the materials processed or for some other reasons, the distance between the first endless conveyer belt 11 and the second endless conveyer belt 13 may be reduced. In such a case, it may be necessary to reduce the height of the paddles 25 on the first endless conveyer belt 11 so as to avoid undesirable interference with the second endless conveyer belt 13 and the materials thereon. In the preferred embodiment, adjustable supports 14 are provided ( FIG. 1 ) so that the second endless conveyer belt 13 may be adjustably located beneath the first endless conveyer belt 11 . The adjustable supports 14 may include a cam mechanism or the like for adjusting the vertical position of the second endless conveyer belt 13 relative to the first endless conveyer belt 11 . Of course, in the alternative, the vertical position of the first endless conveyer belt 11 may be adjusted while the second endless conveyer belt 13 is fixed, or both conveyer belts 11 and 13 may be made vertically movable to adjust the distance therebetween to produce a desired intensity of the magnetic fields.
Also, the height of the paddles 25 may be adjusted to scrape a top layer of the pile of the materials in order to provide efficient, uniform exposure of the material on the second endless conveyer 13 to the magnetic fields.
It is necessary that the selection of the magnets and the spacing therebetween permit the magnetic material to fall back to the second endless conveyer belt 13 before it is attracted to the next downstream magnet. Further in this example, as shown in FIG. 1 , the final magnet 23 includes double magnets 23 a and 23 b . The magnets 23 a and 23 b attract for the final time the magnetic materials that have been separated to be at the upper strata of the composite materials. The materials left on the second endless conveyer belt 13 comprise the lower portion of the strata and are substantially comprised of non-magnetic materials, such as non-ferrous metals and minerals. These materials, conventionally called browns, fall into the first hopper 27 from the second end 41 of the second endless conveyer belt 13 . The materials that are discharged into the second hopper 29 from the first endless conveyer 11 are conventionally called blacks.
FIG. 3A is an enlarged schematic view of the area generally designated 3 A in FIG. 1 . As showvn in FIG. 3A , the field of the magnet 15 attracts magnetic materials, such as ferrous metals and minerals, represented by X's and does not attract the non-magnetic materials, such as non-ferrous metals and minerals, represented by O's. The textured surface of the first endless conveyer belt 11 causes a churning or tumbling of the composite material that is attracted to the first magnetic 15 as the belt 11 slides between the magnet 15 and the magnetic material attracted thereto. This churning or tumbling motion enables more of the non-magnetic materials to drop to the surface of the second endless conveyer belt 13 . In the development of the present invention, the present inventor discovered that with respect to highly conductive non-magnetic material, such as gold, magnets having an MGO e of greater than or equal to 27 effectively repel particles of such material entrapped in the composite material so that those particles will easily drop to the surface of the second endless conveyer belt 13 . The effect is particularly strong in the case of gold particles.
This is believed to be due to the induction effects of the strong magnetic field. The churning or tumbling motion and other motions of the gold particles due to the movements of the endless conveyers create time-varying magnetic field as seen by the gold particles. This time-varying magnetic field induces the surface currents on the gold particles, which in turn create magnetic fields that are repulsive to the magnetic field created by the magnet 15 . Further, the magnetic field enhances the particles' tendency to aggregate into larger particles, which are easily separated from the rest. These effects are particularly useful in forcefully separating metal particles attached to magnetic particles. Thus, gold and other precious metals, which are typically highly conductive, can efficiently be separated by virtue of this mechanism.
FIG. 3B is an enlarged schematic view of the area generally designated 3 B in FIG. 1 . As shown in FIG. 3B , the paddle 25 has just passed the magnet 17 and has pushed the magnetic material that was attracted to the magnet 17 to be out of the field of the magnet 17 until the magnetic materials fall back to the surface of the second endless conveyer belt 13 on top of the layer of non-magnetic materials. As seen from FIG. 3B , this causes further stratification of the composite material with the magnetic (e.g., ferrous) metals and minerals laying on top of the non-magnetic (e.g., non-ferrous) metals and minerals.
FIG. 3C is an enlarged schematic view of the area generally designated 3 C in FIG. 1 . The double magnets 23 a and 23 b are shown as holding within their magnetic fields the magnetic materials. The non-magnetic materials drop from the second (front) end 41 of the second endless conveyer belt 13 into the hopper 27 . The paddle 25 pushes off the magnetic materials that had been attracted to the magnets 23 a and 23 b such that those materials will fall into the hopper 29 .
FIG. 4 shows a wet separation apparatus that comprises another aspect of an embodiment of the present invention. This wet separation apparatus can be used independently, or can be used to further process the browns separated through the use of the apparatus of FIG. 1 . The apparatus of FIG. 4 is particularly effective to separate gold and other precious non-ferrous metals from the browns deposited in the first hopper 27 .
The wet separator apparatus of FIG. 4 includes a bed 61 supported by rear legs 63 and front legs 65 . The rear legs 63 may be fixed to support the bed 61 in a particular height and the front legs 65 are adjustable via a crank or other mechanism (not shown) to adjust the legs in a vertical direction or height as indicated by the arrows shown in FIG. 4 . As is readily understood, vertical adjustment of the legs 65 permits the selection of the slope of the bed 61 from a first (rear) end 67 to a second (front) end 69 . At the first end of the bed 67 is located a source of water 71 that will result in a steady stream of water flowing along a first bed channel 61 a from near the first end 67 to the second end 69 . The water may be discharged from the source 71 at a selectable rate, for example, 60 gallons per minute, to form a continuous stream of water through the first bed channel 61 a.
Downstream of the water source 71 is a feeder 73 for supplying a source material, such as the browns that have been separated by the apparatus shown in FIG. 1 , for example. This feeder 73 may be of any conventional type and is intended to discharge the browns evenly into the first bed channel 61 a of the bed 61 . The browns are discharged into the flowing water in the first bed channel 61 a . The browns are carried by the stream of water beneath a rotating magnetic cross belt 81 that is driven by a motor 83 . As shown in FIG. 5 , the magnetic cross belt 81 rotates in the direction of the arrow shown in FIG. 5 and permits additional magnetic materials to be attracted to the cross belt 81 from the browns that are flowing in the first bed channel 61 a . This is particularly important if the wet separator of FIG, 4 is not processing browns that have previously been processed by the dry separator of FIG. 1 .
Downstream of the magnetic cross belt 81 is a magnetic separator 91 and a mesh area 93 . As shown in FIG. 5 , the magnet separator 91 is comprised of a number of magnetic bars 101 of high strength magnetic material, e.g., magnets having an MGO e greater than or equal to 27. FIG. 5 shows the magnet separator 91 disposed upstream of the mesh area 93 . This is accomplished by movement of a carriage 95 supporting the magnetic separator 91 on rails 97 located on either side of the bed 61 . In a preferred mode of operation, the magnetic separator 91 is placed such that the upstream edge of the magnetic separator 91 is approximately coincident with the upstream edge of the mesh area 93 .
FIG. 6 is a side view of a portion of the wet separator apparatus of FIG. 4 and shows, in particular, the bars 101 of the magnetic separator 91 , downstream thereof, and the upstream portion of the mesh 93 . The proper distance between the magnetic bar 101 can be maintained by a frame sufficiently strong to support the magnets, for example.
FIG. 7 is an enlarged view of a portion of the mesh 93 . In its preferred form, the mesh is a diamond pattern. When the magnetic separator 91 is placed such that its upstream edge is substantially coincident with the upstream edge of the mesh 93 , the magnetic field of the magnetic separator 91 including magnets of the above-stated strength repels gold particles present in the materials carried by the flowing stream of water against the flow of the water stream and into the upstream corners of the mesh pattern as shown in FIG. 7 . This desirable repulsion effect occurs by the mechanism similar to the repulsion mechanism described above with reference to FIG. 3A . That is, the repulsion effect is caused by the induction currents created by the time-varying magnetic field felt by the gold particles in the stream. Further, the magnetic field enhances the tendency of gold particles to aggregate into larger particles, which are easily trapped in the mesh 93 . It is believed that this also is attributed to the induction current effects described above. Similar phenomena occurs with respect to other conductive, non-magnetic materials.
It can be understood that the configuration of the magnet bars 101 in the magnetic separator 91 and the lateral and vertical placements of the magnetic separator 91 relative to the mesh 93 are a matter of design choice depending upon other parameters, such as the flow rate in the water stream, etc., which in turn should be adjusted in accordance with the materials to be processed.
Examples of the mesh 93 that can be used to create an efficient trapping environment for the precious metals include, but are not limited to, Hungarian riffles, reticulated mats having other patterns, etc. As shown in the preferred embodiment above, the reticulated mat having a diamond pattern is preferred for efficiently generating localized vortices, thereby providing better trapping effects. The dimensions of the diamond pattern and its height can be selected depending upon the content and volume of the material processed and the flow rate of the stream to achieve efficient capturing of desired minerals.
The gold particles G accumulate in these upstream portions as more and more of the browns are carried in the water stream from the supply 71 to the second end 69 of the wet separator. The constituent materials of the browns that are not entrapped in the mesh 93 , e.g., the materials other than gold, are discharged from the second end 69 of the first bed channel 61 a and may be disposed of.
After processing a selected volume of the browns through the wet separator apparatus of FIG. 4 , the feeding of the water and the browns is stopped in order to recover the gold particles trapped in the mesh 93 . This may be accomplished as shown in FIG. 8 by rotating the first bed channel 61 a clockwise by use of the handle 111 ( FIG. 4 ) until it is over a second bed channel 61 b . The mesh 93 may be rinsed to cause the gold particles to be moved into the second bed channel 61 b . The gold particles can be discharged into a collection box 115 ( FIG. 8 ) from the second bed channel 61 b.
It is contemplated that the mesh 93 may be divided into a first section (upstream) and a second section (downstream). This is advantageous because the field of the magnetic separator 91 has its greatest effect on gold particles passing in the upstream section of the mesh 93 with the consequence that more pure gold particles will be trapped in an upstream portion of the mesh 93 than in a downstream portion. In this instance, the upstream portion of the mesh 93 may be separately cleaned from the downstream of the mesh 93 by separately rotating those portions and rinsing them. The gold particles from the upstream portion of mesh 93 would be discharged by a suitable discharge chute communicating with an upstream portion of the second bed channel 61 b . The materials trapped in the downstream portion of the mesh 93 could be rinsed into the downstream portion of the second bed channel 61 b and collected in a separate container. The materials recovered from this second container could then be run through the wet separator apparatus again.
Furthermore, as shown in FIG. 4 , one or more of additional auxiliary. magnet elements 117 containing one or more of magnetic bars 101 or other magnets with a high magnetic strength may be removably provided under (or over) the mesh 93 in the downstream side of the magnetic separator 91 to provide additional trapping effects.
One of the unique aspects of the present invention is that the magnetic fields actually act on nonferrous materials. When a source material passes through the equipment chambers a magnetic action occurs. The fine and ultra fine metals and minerals are slowed and attracted to each other. Then as the feedstock materials pass out of the magnet chamber, the specific gravity of the metals and minerals takes effect and, with back eddies that are being created, are captured in riffles on the decks of the equipment.
In this embodiment, only plain water (which can often be recirculated) and a relatively small amount of power are required.
The separation apparatus as embodied in the examples above may be construted of appropriately designed modular components so that the apparatus may be easily transported to operation locations and assembled reliably and efficiently. A working model, which was constructed in such a modular design, allows processing of 1 ton per hour up to 100 tons per hour or more depending on project requirements and the nature of the materials. Of course, a more permanently based, large scale processing line may be constructed for use at large precessing sites as the need arises.
As described above, while passing through chambers having magnetic field strengths in excess of 27 MGO e , the present invention causes physical effects on certain non-ferrous materials causing high efficiency separation of the ferrous and non-ferrous materials. As shown in the examples above, processing is accomplished in a wet or dry mode depending on the nature of the materials. A separation system may be constructed by combining the above-described dry system and wet system. Depending upon the nature and content of the source material, the source material and the target material may be introduced and collected, respectively, in various appropriate stages of the combined separation system.
Using the apparatuses and methods of the present invention described above, similar high-degree separation can be achieved with respect to not only gold, but also other precious metals, such as platinum, mercury, palladium, etc., or toxic minerals.
ENVIRONMENTALLY FRIENDLY TOXIC SUBSTANCE SEPARATION
It is particularly contemplated that the material separations systems and methods of the present invention disclosed above can be used in isolating toxic substances and contaminants, such as mercury, most lead materials, antimony, and sulfides from soil or sediments that are naturally occurring or artificially created. Utilizing the present novel magnetic technology described above, separation of these heavy media contaminants and minerals can be effectuated at a lower cost with a high efficiency. Particularly noteworthy is that, as compared with the conventional chemical separation methods, systems according to the present invention yields no adverse environmental impact.
According to this aspect of the present invention, separation apparatus and method of the present invention enable efficient and environmentally friendly separation and recovery, from a host of ferrous and non-ferrous metals, of mercury, certain lead minerals and a variety of other contaminants on the environmental cleanup sites, as well as gold, silver, platinum and other commercial products that may be present.
The separation system of the present invention actually removes contaminants from the soil, eliminating the hazardous materials, as opposed to merely covering them up, allowing for a safer and restriction free use of previously contaminated property, for example. Furthermore, the separation system of the present invention often recovers, in a significant amount, metals or other valuable that other separation schemes leave behind. In certain cases, the potential recovery can well exceed the cost of clean up.
Operational sites of the present invention include superfund sites, abandoned mines and mill sites, tailing dumps and deposits of naturally occurring contaminants, as well as contamination resulting from a variety of industrial or governmental operations.
The modular design of the apparatus described above allows for the proper allocation of equipment regardless of the scope of the project. This increases efficiency on the operations side while eliminating costs relating to excess “hardware.” This modular approach also reduces manpower expenditures, requiring only that number of technicians necessary to run the appropriate number of machines. Thus, depending upon the size and nature of a particular cleanup or metal value separation project, the actual costs may very. Yet, as compared with the conventional technologies, it is apparent that the present invention provides for highly cost-efficient, environmentally clean schemes for toxic substance removal and metal values separation.
It will be apparent to those skilled in the art that various modifications and variations can be made in the separating method and apparatus of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | Apparatus is provided for separating non-magnetic mineral values from a source containing magnetic material and non magnetic material. The apparatus includes first and second conveyers in overlying relation which counter-rotate relative to one another. One of the conveyers includes a magnetic assembly which cooperates with paddles on the upper conveyer to progressively isolate values from magnetic material. Multiple stages are provided for intermittent magnetic interactions such that the non-magnetic materials are effectively isolated from the magnetic materials. | 1 |
FIELD OF THE INVENTION
The invention generally relates to the fields of (i) quantum computers, (ii) physical devices which trap ions in electrodynamic potential wells. More specifically, the invention relates to the interrelationship between these two fields, for the use of such trapped ions for quantum logic operations and quantum computation. The invention has particular applicability to computer architecture.
BACKGROUND OF THE INVENTION
This invention relates to quantum computation, a new field which combines ideas from computer science, quantum mechanics, and atomic physics to create a qualitatively new kind of computing device. The invention also relates to ion traps and ion trap arrays as a means of realizing a quantum computer.
Quantum computation has recently become an important area of research that combines ideas in computer science, quantum mechanics, and atomic physics. Computers based on quantum mechanical principles are predicted to be 10 to 20 orders of magnitude more powerful than any classical machine and thereby solve problems which at present are too complex for numerical solution.
Many current computers utilize devices such as transistors which rely on quantum mechanics for their operation. However, such computers must be called "classical" in the present context, since each logic gate yields a voltage or current which can be measured by a ordinary voltmeter.
Quantum computers, on the other hand, employ quantum logic gates which can output superposition states of logical "1" and "0", which cannot be measured directly, due to Heisenberg's uncertainty principle. Quantum computers gain their advantage over conventional silicon computers due to an intrinsic quantum phenomenon first recognized by Deutsch (Proc. R. Soc. Lond. A400, 97, 1985) called "quantum parallelism". This phenomenon rests on the ability of quantum superposition states to represent many different numbers simultaneously.
It is important to distinguish this "quantum parallelism", which is common to all quantum computers from the "architectural parallelism" which is the subject of this invention, as will be discussed in more detail below.
In 1994 Peter Shor invented an algorithm which uses quantum parallelism to factor large integers exponentially faster than any classical machine. This theoretical discovery has had important practical applications, since the security of RSA public key cryptographic systems (see U.S. Pat. No. 4,405,829, Rivest et al., "Cryptographic Communications System and Method") rests on the assumption that large enough integers can never be factored in practice.
Shor's algorithm stimulated experimental work, by showing that there was at least one important problem that was solvable by a specific quantum mechanical procedure that had no classical counterpart. Moreover, practical quantum computers would threaten much current Internet commerce, which commonly uses an RSA public key cryptographic system.
Discussion of quantum computing began in the early 1980's with papers by Richard Feynman (Found. Phys. 16, 507, 1986) and Deutsch. Given the historical exponential increase in circuit density with time, Feynman realized that, in the not-too-distant future, microelectronic devices would in principle shrink to atomic dimensions, so that their quantum mechanical features would become important.
Quantum computation is an attempt to exploit this regime, by assuming that each logical element is an ideal quantum system, unperturbed by the environment. In 1985, Deutsch developed a model of an idealized quantum computer called a quantum Turing machine, based on this assumption. However, until Shor's algorithm in 1994, no specific problem was known which was uniquely solvable by quantum techniques.
The ideal quantum systems assumed by theorists do not exist in ordinary electronic devices, which typically have negligible quantum lifetimes. Practical quantum computing devices have therefore been sought primarily in single atoms which are isolated from the outside world and kept at extremely low temperatures.
The most widely discussed model is that of Cirac and Zoller (Phys. Rev. Lett. 74, 4091, 1995) who showed how to use laser-cooled trapped ions as quantum logic and memory devices. In an ion trap, individual atoms are suspended by electromagnetic forces in a ultra-high vacuum, where they are almost completely decoupled from their environment.
The general principles underlying ion trap operation have been described in the literature and in U.S. Pat. Nos. 5,248,883 and in 5,379,000. Trapped ions have been laser-cooled to temperatures below 1 microkelvin, where they are essentially stationary, occupying the quantum mechanical ground state of the trap. Such systems have been shown to have quantum lifetimes, of minutes or longer, which are necessary for quantum computation.
Recently, Monroe et. al. (Phys. Rev. Lett. 75, 4714, 1995) have used a trapped single ion to construct the first working quantum logic gate. Preskill et. al. (Phys. Rev. A54, 1034, 1996) have worked out the complete set of quantum programming instructions required to evaluate Shor's algorithm in the Cirac-Zoller model. Three groups are currently engaged in building prototype ion trap quantum CPU's (central processing units) to evaluate Shor's algorithm for a small number of bits.
It is important to note that many other physical systems have been proposed for quantum logic, for example, nuclear spins in solids, interacting quantum dots (DiVincenzo, U.S. Pat. No. 5,530,263) , and photons confined in a optical cavity. The photon model has even been tested in an experiment by Kimble et. al. (Phys. Rev. Lett. 75, 4710, 1995). However, all systems other than the Cirac-Zoller model are far from practical use, even in prototype form, and no analysis has been made of how to combine them into a CPU.
The Cirac-Zoller Quantum Computer
To understand how the present invention overcomes some of the limitations of the Cirac-Zoller ion trap quantum computer, it is necessary to describe that prior art quantum computer in detail.
FIG. 1 shows the Cirac-Zoller computer, which consists of a linear ion trap containing a row of laser-cooled trapped ions, each of which can be excited by a laser beam. The details of the linear ion trap and laser cooling will be described below.
Each trapped ion contains long-lived internal energy levels, which can be used for logic and for storage of a single quantum bit, called a "qubit". A qubit differs from a classical bit in that it can be in a superposition state of logical "1" and "0". By contrast, a classical bit must either be a "0" or a "1", and cannot be both at the same time.
FIG. 2 shows an energy level diagram of a two-level system, typically a pair of ground state hyperfine levels, in which the ground state "a" represents a logical 0 and the excited state "b" represents a logical 1.
It is well known in quantum mechanics that atoms can exist in superposition states, in which the atom is in simultaneously in state "a" with probability c(a)*c(a) and in state "b" with probability c(b)*c(b), where c is Schroedinger's wave function for the system. Thus each quantum bit can represent two numbers at once, and N qubits can represent 2 N numbers simultaneously. This is a unique feature of quantum mechanics, which permits exponentially large arrays of numbers to be processed at the same instant, in contrast to a classical CPU which can only process one number at a time.
To be useful for quantum computation, trapped atoms must not only store qubits, but also must transmit quantum information from one atom to another and must perform logical operations such as AND and OR on qubits stored in different atoms. In the Cirac-Zoller model, this is performed by a second type of quantum system called the center-of-mass phonon, which is shared by all the ions and which serves as a quantum communications channel, as shown in FIG. 3.
The center-of-mass phonon, abbreviated "c.m." phonon, represents a mechanical vibration of the entire ion crystal in the trap potential. Cirac and Zoller (Phys. Rev. Lett. 74, 4091, 1995) showed how a laser pulse, applied, for example, to the N-th ion, could transfer the wavefunction of that ion's internal levels to the first two c.m. phonon levels. Another laser pulse, applied to the M-th ion, can then write the wavefunction out of the c.m. phonon into the internal levels of the M-th atom. The net result is that the wavefunction of atom N has been transferred to atom M, achieving the goal of quantum communication. A similar process can be used to form an fundamental quantum logic gate, the exclusive OR gate, as is described in the literature.
Several limitations exist, both in the overall organization or architecture of the Cirac-Zoller quantum computer, and in the specific physical properties of the ion trap.
The architectural limitation consists of the use of only one quantum communication channel, the c.m. phonon, to carry all the information between each quantum bit (e.g. ion) in the array. This is a serial architecture, since all the operations on each bit must proceed in order one after the other through the c.m. phonon.
FIG. 4 shows a schematic drawing of the serial architecture of Cirac and Zoller, in which a solid double line represents the quantum communication channel (a shared quantum system, e.g., a trap phonon) and each of the large dots represents a single quantum logic or memory element, (e.g. a single trapped ion).
Shor's algorithm requires repeated arithmetic operations on numbers several hundred bits long, so that use of the architecture of FIG. 4 results in a severe penalty in execution time and efficiency. For example, to add two 100-bit numbers in this architecture requires 100 separate bit-by-bit additions, each occurring one after the other over the same quantum channel. This is in contrast to conventional silicon computers which use parallel architecture where many bits are added simultaneously and algorithms are used to compute carry bits.
A detailed examination of the specific operations required by Shor's algorithm shows that the limitation of a serial architecture is even more severe than indicated above. Preskill (Phys. Rev. A54, 1034, 1996) has tabulated all the operations required and shown that an calculation on a K bit number requires 5K+1 ions and approximately K 2 separate K-bit additions. The extra qubits are required, to allow for overflow and to provide temporary registers to store intermediate results. A K=200 bit word therefore implies that the trap must contain over 1000 ions, all communicating over a single quantum channel. This requires over 10 9 operations on the c.m. phonon to carry out. This puts a severe burden on the technology.
Optimization of the architecture for a quantum computer raises new questions that have not been considered for conventional computers. This is because, in a conventional computer, the communications channel can be an ordinary copper wire or a trace on a printed circuit board. It is usually the lowest technology, and the cheapest part of the computer. In a quantum computer, on the other hand, the quantum communications channel is the most difficult and the most high-technology part of the device.
Effective quantum channels have only been demonstrated in the last few years. Only two types have been tested experimentally, the vibrational phonons associated with laser-cooled ion traps (Phys. Rev. Lett.75, 4714, 1995) and photons coupled to single atoms in optical cavities ( Phys. Rev. Lett. 75, 4710,1995).
Moreover, a quantum channel must be kept free from interaction with the environment. Such interaction tends to destroy the pure quantum states necessary for computation and limit the power of the computer. Only in the last few years, for example, have the necessary laser cooling techniques (Raman cooling, Phys. Rev. Lett. 75, 4011, 1995) been developed. Hence, architectural questions in quantum computers that is, the arrangement of the logic, the memory, and the communications channel, raise complex questions of physics. The optimum architecture may also differ because of the different economics and efficiency of the quantum logic, memory, and communications.
A general reason why a serial architecture has conventionally been chosen is that linear ion traps are very difficult to construct and to operate. This is because each quantum channel requires a separate ion trap. Use of only one trap forces a serial architecture.
Linear Ion Traps
Other limitations in quantum computer architecture also arise from the detailed physical properties of linear ion traps.
Linear ion traps were first proposed by Prestage et. al. (J. Appl. Phys. 66, 1013, 1989), and their design has been discussed in the literature (Phys. Rev. A45, 6493, 1992). A conventional linear ion trap consists of four electrodes in the shape of long rods of circular cross section.
A radio frequency potential of a certain frequency is applied between opposite pairs of electrodes, as shown in FIG. 1, creating an effective transverse potential well which confines the ions in a state of dynamic equilibrium as discussed in U.S. Pat. Nos. 5,248,883 and 5,379,000. The radio frequency field provides little or no confinement along the z-axis. Instead, a weak D.C. field is applied through two endcap electrodes. The weak confinement along the z-axis makes it energetically favorable for laser-cooled ions to condense in a long row on the z-axis.
With appropriate laser cooling the ions can be held in an essentially stationary array, essentially as a linear ion crystal, for many hours. The advantage of a linear ion trap, compared to the usual 3-dimensional trap, is that an arbitrarily large number of ions may be stored along the z-axis by extending the length of the rods as needed. These ions can then be laser-cooled to near the quantum mechanical ground state, since they are free from micromotion, as discussed in the literature.
Linear ion traps, however, also have limitations as to their usability for quantum computer architecture.
The first limitation resulting from the use of a linear ion trap is that the traps have a complex 3-dimensional structure, which is difficult to fabricate in the required miniature size. Miniaturization is desirable because the smaller the trap, the faster the quantum computer can operate. This is because the computer can operate no faster than the frequency of vibrational phonon, and the phonon frequency is proportional to the trap electric field , which is inversely proportional to the dimensions of the trap electrodes. The smaller the trap, the higher the field, the strong the trap force, the higher the phonon frequency, and the faster the computer clock can operate.
Current linear ion traps are machined at the limits of conventional technology, with rods several hundred microns in diameter. This leads to single ion oscillation frequencies of 10-100 kHz.
A second limitation of a linear ion trap is that the c.m. phonon frequency, and thereby the computer speed, drops as the number of trapped ions increases. The phonon frequency obeys the simple harmonic oscillator relation sqrt(k/M) where k is the spring constant and M the mass of all the ions. The large number of ions required for quantum computation (1000 to 10,000) therefore means the c.m. phonon frequencies will be about 30 times smaller than for a single ion. Consequently, the computer will operate that much more slowly.
A third limitation is that the construction of the linear ion trap is not modular. That is, since the c.m. phonon frequency depends on the number of ions in the trap, the basic operating parameters of the computer vary as more ions are added. The behavior of a large computer containing 1000 trapped ions is difficult to predict experimentally, and cannot be directly inferred from the properties of a small device. The maximum number of ions trapped to date is about 30.
Finally, the limitations of architecture and of linear trap physics work against each other and provide an upper limit of the size of a number to be factored. With a serial architecture, the number of additions goes up like K 2 , while the computer speed goes down like sqrt(K), for a given level of technology.
In addition to use of the c.m. phonon as a quantum communication channel, Zoller et. al. (Phys. Rev. Lett. 75, 3788, 1995) have also shown that photons in an optical cavity can form a quantum communications channel, as shown in FIG. 5.
An optical mode of the cavity resonant with transitions of atoms A and B is used as a quantum communication channel, as shown in FIG. 6.
The atoms contain a 3-level structure in which the ground state is split into two sublevels which store the quantum information. The two sublevels correspond with the wavefunction c(a) and c(b). One of the two transitions of each atom is driven by an external laser, while the other is resonant with the cavity photon. Information is transferred between a given two atoms by illuminating these two atoms with pulsed laser beams, the beams having a complex overlapping pulse shape.
In such a channel, the wavefunction is transferred from one atom to another in the same cavity, using a method called "adiabatic passage via a dark state of the 2-atom cavity system". This mechanism is inherently quantum mechanical, and rests on previous work in cavity quantum electrodynamics ( "Cavity Quantum Electrodynamics", P. Berman, Acad. Press, 1993) and adiabatic passage (Parkins et. al., Phys. Rev. Lett. 71, 3095, 1993).
The net result is that the wavefunction is transferred from one atom to another with high efficiency. The use of a "dark state" means that the cavity photon is "virtual" so that the effect of spontaneous emission is greatly reduced. The design of quantum computers using cavity photons is far behind that of ion trap computers, and no detailed designs have been reported.
In summary, existing technology for producing quantum computers using trapped ions has had the following drawbacks: First, conventional quantum computers use only one quantum channel, and thus require a serial architecture which limits computer speed. Second, they use a linear ion trap, which is difficult and expensive to construct in the required miniature size. Third, they put a large number of ions in the same trap, which lowers the phonon frequency and the compute speed. Fourth, they are not modular in architecture, so that adding bits in the computer requires a redesign of all the computer parameters. These limitations have been found to be so severe that they threaten the practicality of the Cirac-Zoller quantum computer.
Therefore, there is a need for a quantum computer technology which overcomes these drawbacks.
SUMMARY OF THE INVENTION
It is therefore the object of this invention to provide an apparatus and method of organization of quantum computers, using a parallel architecture, to increase the speed and efficiency of computation.
It is a further object of the invention to efficiently and economically realize this parallel architecture through the manufacture of ion trap arrays which are simple both in design and construction.
Specifically, an object of the present invention is to provide four parallel architectures for optimizing the performance of quantum computers. By "architecture," we mean a specific set of relations between quantum logic, memory, and communications channels. Quantum architectures are different from those of conventional computers (e.g. silicon microprocessors) because of the different physics, technology, and economic value placed on logic, memory, and communications channels in the two cases.
The new quantum architectures described in this invention use many "small" quantum channels for frequently performed logic and memory operations and a few "large" channels for infrequently performed operations. By a "small" channel we mean a channel that connects a small number of quantum bits, for example, 2 to 20. The small channels operate in parallel, so that an entire N-bit quantum word can be written from one location to another in a single operation. The small channels also permit the use of algorithms to increase the speed of elementary mathematical operations such addition and multiplication. This represents a basic improvement over the serial Cirac-Zoller architecture of the prior art. Another advantage is that the small channels have faster intrinsic operation times and lower error rates due to their physics.
Additionally, it is another object of this invention to provide a method of constructing parallel quantum computers using ion trap arrays, where each small quantum channel is physically realized by an ion trap of a novel design. This invention therefore replaces one large linear trap, which typically might contain several thousand ions, with an array of several hundred small traps each containing a few ions. This overcomes several limitations of prior art which were discussed above.
First, each trap contains its own c.m. phonon so that there are now many quantum communication channels, for example, one channel per quantum bit. The trap array thus constitutes a parallel architecture, as noted above. Second, each trap now contains only a few ions, so that the c.m. phonon frequency remains high, further enhancing the computer speed, in a typical case by a factor of 20. Third, each trap can now be physically small, which increases the phonon frequency and, therefore, the computer clock speed.
Furthermore, it is another object of this invention to provide a method of constructing planar traps using a new elliptical geometry specifically designed for quantum computation and not taught in the previous planar trap U.S. Pat. Nos. 5,248,883 and 5,379,000. These elliptical traps have the same function as a linear ion trap, to confine a row of ions for use as quantum bits, but are simpler in design and construction so that they may be microfabricated by photolithography.
By using mass production methods common in the integrated circuit industry, it is intended that the manufacture an entire array of several hundred traps would be more economical and efficient than the construction by hand of a single linear ion trap.
To achieve these objects, parallel architecture for quantum computers and its realization by arrays of elliptical planar ion traps are described and claimed below. Specifically we provide four basic preferred architectures for quantum computers. The four architectures are designated the nearest-neighbor model, quantum bus model, a model which combines both, and a 2-dimensional array model.
At present, several physical implementations of quantum computer elements have been proposed. Any of them may be used to implement the architectures of the invention.
In particular, one preferred form of a quantum computer element is an ion trap. The four quantum computer architectures are preferably implemented, as ion traps, as per any of eight basic configurations of elliptical planar ion trap which are taught in U.S. Pat. No. 5,248,883.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the standard model of a linear ion trap quantum computer as described by Cirac and Zoller.
FIG. 2 shows the energy levels of a single ion in a trap including the internal atomic energy levels a and b and the levels of the trap phonon.
FIG. 3 shows the transmission of quantum information from one atom to another using the shared c.m. phonon as a quantum communication channel.
FIG. 4 shows a schematic diagram of the serial architecture of the standard ion trap model, the Cirac-Zoller model.
FIG. 5 shows an a quantum communications channel using cavity photons.
FIG. 6 shows the energy levels of two atoms exchanging quantum information by a cavity photon communications channel.
FIG. 7 shows the architecture of the first basic parallel quantum architecture in which many registers are connected by short channels.
FIG. 8 shows the second basic parallel quantum architecture in which the registers are connected to one quantum bus.
FIG. 9 shows the third basic parallel quantum architecture in which the registers are connected separately together by short channels and also to a quantum bus.
FIG. 10 shows the fourth basic parallel quantum architecture in which there are L rows of registers, each of which is connected to its four nearest neighbors in 2 dimensions by short channels.
FIG. 11 shows the first basic elliptical planar ion trap which traps K ions to embody one register.
FIG. 12 shows an array of elliptical planar ion traps where each trap represents one bit of a long quantum word.
FIG. 13 shows two elliptical planar ion traps and a three-mirror optical resonant cavity which forms a communications channel for transmitting quantum information from one trap to the other.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Quantum computers require new architectures because the physics and technology of the quantum logic, memory, and communication channels are entirely different from those of conventional silicon computers. The design of the architectures in particular is driven by the need to overcome the limitations of the quantum communications channels, which are the most difficult and critical part of a quantum computer. The most important limitation in the quantum case is that the computation rate of the entire computer is limited by the data transmission rate of the quantum channels. Furthermore, the quantum channel speed drops rapidly as the number of logic and memory elements connected to it increases.
Only two types of quantum channels are known today, phonons in ion traps and photons in optical cavities. Both channels display this above-mentioned limiting behavior.
In the trap phonon model, the data transmission rate must be substantially less than the trap phonon frequency. This is because the width of the laser pulses which couple the ions to the phonon is limited by the Fourier Theorem. If the pulses are too short, the Fourier spectrum of the pulse will excite several phonon levels at once and destroy the integrity of the channel. Typical phonon frequencies for single ions in linear ion traps range from about 10 KHz to 100 KHz, and the fundamental computer clock rate can be no greater than this. Moreover, as mentioned above, the phonon frequency is inversely proportional to the square root of the number of ions in the trap. Since useful computers are expected to require 1000 to 10,000 ions, the fundamental clock rate will be less than 1 KHz. Note that this is about 5 orders of magnitude slower than current silicon microprocessors.
A similar effect occurs for cavity photon channels. In this case, data transmission speeds are on the order of 1 MHz, but a similar reduction of the data rate with number of atoms occurs here. The limiting speed of this method is governed by a parameter called the "vacuum Rabi frequency", which is inversely proportional to the square root of the cavity mode volume (Phys. Rev. Lett. 75, 3788, 1995). For a long thin cavity mode, this volume will be proportional to the number of atoms inside, which leads to the same dependence on the inverse square root as in the ion trap case. Thus we expect, from the only quantum channels so far investigated, that channels which connect the fewest atoms will be the fastest.
As a result, the governing principle of quantum architecture is that many short quantum channels will be better than one large one. Note that the architecture of the Cirac-Zoller computer shown in FIG. 4 violates this principle maximally. The challenge of quantum architecture is to arrange these short channels in ways that optimize a given computing problem. This is the goal which is accomplished by the invention.
Detailed Descriptions of Preferred Architectures According to the Invention
The preferred architectures, according to the invention, have in common that they present quantum element structures which deal with a small number of quantum elements (such as trapped ions). In general, "small," in practice, preferably means about 2 to 20 quantum elements. By contrast, the above-discussed conventional quantum computer architectures, employing on the order of 1000 quantum elements, fall outside the range of what is considered "small" for the purpose of this invention. Note, however, that conventional quantum computers, which employ only a single quantum channel, must include within that channel a sufficient number of quantum elements to provide adequate computing power. By contrast, the invention employs multiple channels, thereby allowing for the use of a small number of quantum elements per channel, while still providing advantageous overall computing power.
The first parallel architecture is diagramed in FIG. 7, which shows a series of small quantum channels, called "registers". Each such register communicates between a small number K of quantum logic/memory elements, typically 2 to 20. The registers are preferably disposed substantially parallel to each other, as shown, so that neighboring or corresponding elements of different registers line up, or otherwise correspond, with each other.
In quantum computing, logic and memory are performed by the same physical object. Each logic/memory element connected to a register is called a "location". In a typical case, a quantum computer designed to process N-bit quantum words would contain N separate registers, with one register assigned to all the logic and memory functions for a given bit n of the N-bit quantum word. Thus, the n-th register contains up to K different locations for storing the n-th bit of K different quantum words. Each location acts like a different quantum memory element, so that an entire N-bit quantum word can be moved from one storage location to another in a single parallel operation.
Each register is connected to its nearest neighbors on the right and left by short "carry" channels, which connect a location of one register to that of another. This permits quantum information to be transferred from register to register, for example, to propagate the carry bit in a binary addition.
The second parallel architecture is diagramed in FIG. 8, which shows a series of small quantum channels, called "registers", each of which communicates between a small number K of quantum logic/memory elements, typically 2 to 20. Each register is connected by a small 2-bit channel to a large quantum channel called a quantum bus, which, for the case of an N-bit quantum word, will communicate between all N quantum bits. The bus therefore communicates between any two registers with the same speed regardless of whether they represent low-order or high-order bits. Because this channel connects many registers, however, it will be technically complex, expensive, and will have a slower quantum data transfer rate than the short channels of the first architecture. However, there are certain kinds of logical and arithmetic operations which require communication between low-order and high order bits.
The third parallel architecture is diagramed in FIG. 9, which shows a series of small quantum channels, called "registers", each of which communicates between a small number K of quantum logic/memory elements, typically 2 to 20. Each register is connected both to its nearest neighbors on the right and left by short "carry" channels, and also to a large quantum channel called a quantum bus by a small 2-bit channel. This architecture, while more complex technically, combines the advantages of the first and second architectures without penalty. It provides short, high speed quantum channels for frequent communication between neighboring bits, and further provides one slow channel for infrequent, but more complex, coupling between low and high order bits.
The fourth parallel architecture is shown in FIG. 10, and includes a two-dimensional array of small quantum channels, called "registers", each of which communicates between a small number K of quantum logic/memory elements, typically 2 to 20. Each register is connected both to its nearest neighbors on the right and left by short "carry" channels, and is also connected to the register immediately above and below it, by short carry channels.
Many variations on this architecture are apparent to those skilled in the art. For example, for certain applications, the quantum bus might connect only a subset of the N-bits. It is also assumed that, for certain applications, the short carry channels might not connect to a nearest neighbor, but rather to a second nearest neighbor, and so on.
The first basic planar configuration is a one-hole trap which comprises three parallel, electrically conductive sheets separated by dielectrics disposed on the outer edges of said sheets, the inner sheet having an elliptical hole. The one-hole trap further has a means to apply an RF field between the center sheet and the two outer sheets such that the resulting electric field being generated in the space defined by the elliptical hole and the two outer sheets has a characteristic of a substantially quadrupole field, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The second basic planar configuration is a three-hole trap which comprises three parallel, electrically conductive sheets separated by dielectrics disposed on the outer edges of said sheets, each of the three sheets having elliptical holes and said elliptical holes are symmetrically aligned substantially along a common axis. The three hole trap further has a means to apply an RF field between the center sheet and the two outer sheets such that the resulting electric field being generated in the space defined by the three aligned elliptical holes has a characteristic of a substantially quadrupole field, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The third basic planar configuration is a concentric-ring trap which comprises an outer elliptical ring and at least one inner elliptical ring made of electrically conductive material disposed on a same plane, these multiple rings being symmetrically aligned substantially along a common axis. The concentric ring trap further has a means for impressing an RF potential in between any two rings. A resulting electric field is generated in a region above the plane of the multiple rings having a characteristic of a substantially quadrupole field, whereby a charged particle in being injected into the space floats above the rings and is confined in said field, maintaining a dynamic equilibrium condition.
The fourth basic planar configuration is a three-ring trap which comprises two outer elliptical rings and an inner elliptical ring made of electrically conductive material disposed on three substantially parallel planes, said three rings being symmetrically aligned substantially along a common axis. The three-ring trap also has a means for impressing an RF potential between the inner ring and the two outer rings. Furthermore, the two outer rings have radii of the same length, the inner ring has a greater radius, and the outer rings are maintained at the same distance from the inner ring. The spacing between the rings is adjusted as a function of the radii of the outer rings and the inner rings such that the resulting electric field being generated in the space defined by the three aligned rings has a characteristic of a substantially quadrupole field up to a high harmonic order, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The fifth basic planar configuration is a two-ring trap which comprises two elliptical rings made of electrically conductive material disposed on two substantially parallel planes, said two rings being symmetrically aligned substantially along a common axis. The two-ring trap also has a means for impressing an RF potential between the two rings, which are electrically connected together so that they are at the same potential, and a distant ground electrode, whose shape is not critical. Furthermore, the two outer elliptical rings have radii of the same length. The spacing between the rings is adjusted as a function of the radii of the rings such that the resulting electric field being generated in the space between the rings has the characteristic of a substantially quadrupole field up to a high harmonic order, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The sixth basic planar configuration is a four-ring trap which comprises two outer elliptical rings and two inner elliptical rings made of electrically conductive material disposed on four substantially parallel planes, said four rings being symmetrically aligned substantially along a common axis. The four-ring trap also has a means for impressing an RF potential between the two inner rings, which electrically connected together so that they are at the same potential, and the two outer rings, which are also electrically connected together so that they are at the same potential. Furthermore, the two inner rings have radii of the same length and the two outer rings have radii of the same length. The spacing and radii of the inner and outer rings is adjusted such that the resulting electric field being generated in the space between the rings has the characteristic of a substantially quadrupole field up to a high harmonic order, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The seventh basic planar configuration is a two-hole trap which comprises two parallel, electrically conductive sheets, each sheet having an elliptical hole, the elliptical holes being symmetrically aligned substantially along a common axis. The sheets may be separated by dielectrics disposed on the outer edges of the sheets. The two-hole trap also has a means for impressing an RF potential between the two sheets, which are electrically connected together so that they are at the same potential, and a distant ground, whose shape is not critical. The spacing between the two sheets is adjusted as a function of the radii of the holes such that the electric field being generated in the space between the holes has the characteristic of a substantially quadrupole field up to a high harmonic order, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The eighth basic planar configuration is a four-hole trap which comprises four parallel, electrically conductive sheets, each sheet having an elliptical hole, the elliptical holes being symmetrically aligned substantially along a common axis. The inner holes are of substantially the same radius and the two outer holes are also of substantially the same radius. The sheets may be separated by dielectric disposed on the outer edges of the sheets. The four hole trap also has a means for impressing an RF potential between the two inner sheets, which are electrically connected together so that they are at the same potential, and the two outer sheets, which are also electrically connected together so that they are at the same potential. The spacing between the sheets is adjusted as a function of the radii of the holes such that the electric field being generated in the space between the inner holes has the characteristic of a substantially quadrupole field up to a high harmonic order, whereby a charged particle in being injected into the space is confined in said field, maintaining a dynamic equilibrium condition.
The four architectures of this patent carry out this goal in several different ways. In general, they provide one register for each bit of a quantum word. Within each register, there are K locations for storage and logic. This permits parallel storage and retrieval of long quantum words. Shor's algorithm typically uses quantum words several hundred bits long, so in this case there would be several hundred registers connected as in FIGS. 7-10. The K locations in each register can used for different purposes, for example, for storage of intermediate results and as locations for the auxiliary bits required for quantum error correction (Phys Rev. Lett. 77, 2585, 1996). The first 3 architectures contain a single row of registers, one register for each bit of a quantum word but differ in their coupling between adjacent registers. The first architecture, called the nearest neighbor model, contains a channel coupling one location of one register to one location of the nearest neighbor to the right and to the left. Since this coupling channel is contains only two logic/memory elements, it will be advantageously fast. Since the registers contain less than about 20 logic/memory elements, they will also be fast.
This architecture is suited for problems such as repeated additions from the K locations, where the carry bit is propagated by the nearest neighbor channel. The second architecture couples all of the registers to one long quantum channel called the quantum bus. Since the bus must contain at least N logic/memory elements, it will be relatively slow. However it will still be faster than the Cirac-Zoller model, which requires 5N+1 logic/memory elements for an N bit quantum word. The additional 4N+1 elements are used for temporary storage and as ancillary bits for making the calculation unitary and reversible (Phys. Rev. A54, 1034, 1996).
This architecture is optimized for operations involving high-order and low-order bits, for example, the bit reversal operation which is part of the Fast Fourier transform required for Shor's algorithm (Rev. Mod. Phys. 68, 733, 1996).
The third architecture is a straightforward combination of the first and second architectures in which separate locations are provided for coupling both to nearest neighbors and to a quantum bus. This combination is more complex to realize, but the two couplings do not interfere with each other, so that short and long channels can be used as needed.
Those skilled in the art will also recognize many variations on these architectures. For example, the quantum bus might be broken up into sub-busses connecting certain groups of bits to optimize certain calculations. Alternatively, there may be arrangements in which one register might represent two quantum bits.
The fourth basic architecture is a two-dimensional array of registers, each connected by nearest neighbor links, both the right and the left and from top to bottom. Each of the links connects only two logic/memory elements in each register, so they will be fast.
While the most technically complex, this architecture permits the execution of fast parallel algorithms for multiplication as in conventional computers. See "Computer Architecture: A Quantitative Approach", Hennessy and Patterson, Morgan-Kaufmann, San Francisco, 1996. Such algorithms increase computer speed by factors of greater than sqrt(N), where N is the number of bits. For a 500-bit computer, this is a 20-fold increase in speed.
The novelty of the invention is that it is the first and only quantum computer design to permit parallel algorithms and computation.
Physical Realizations of the Architectures
These architectures can be realized with novel elliptical planar ion traps shown in FIG. 11. The traps are constructed from a single flat conducting sheet in which elliptical holes have been microfabricated by photolithography. This produces an electric field within the aperture of substantially quadrupole form which confines charged particles in a condition of electrodynamic equilibrium. Each trap performs the function of a linear ion trap, but is smaller, has higher phonon frequencies for faster computation speeds, and can economically be constructed in large linear arrays for architectures 1-3 and in two dimensional arrays for architecture 4. Each trap embodies one register and each trapped ion corresponds to one location. The trap phonon acts as the quantum communications channel within the register and additional devices, employing either phonons or photons, are used as the short coupling channels between registers.
The preferred embodiment of the elliptical planar trap has major axes of 300 microns diameter and minor axes of 200 microns diameter, which are chosen to be consistent with prototypes whose working properties are well known. The axes of traps in an array are parallel to each other and the distances from trap center to trap center are approximately 500 microns, giving a linear density of 50 traps per inch. All the traps are constructed in a single photolithographic process so that a row of 400 traps can be fabricated along the diameter of a single 8 inch silicon wafer, leaving room for auxiliary classical and quantum circuitry. For simplicity, the trap design uses only a single conducting sheet, and is an elliptical modification of the first basic planar configuration of U.S. Pat. Nos. 5,248,883 and 5,379,000, although other configurations could also be used.
The elliptical planar trap provides the same function as a linear trap and produces strong trap forces along two axes and weak forces along the third axis, on which laser-cooled ions condense in a long row. To achieve this goal with our planar design, which previously used only circular apertures, we elongate one axis of the circle to form an ellipse. The electric field will now be weaker along this axis because the same potential drop now occurs across a greater distance. The major axis of the ellipse becomes the weak axis along which a row of ions will condense. No detailed calculation of the field distribution in an elliptical hole has yet been carried out and it is not known whether another shape might provide a quadrupole field with fewer higher order terms. However, approximately elliptical traps have been constructed and laser-cooled barium ions have been observed to condense in a row on the major axis. This has occurred in imperfectly machined prototype planar traps where, for example, a hole intended to be circular in shape with a radius of 100 microns, was in fact constructed with approximately elliptical shape with 80 and 100 micron minor and major radii. To construct a trap capable of holding up to 20 ions it is necessary to design an elliptical trap of greater eccentricity, for example, a 1.5 to 1 ratio of major and minor axes, and to microfabricate the aperture with greater precision. This is well within the art since typical tolerances for photolithography are well below 1 micron, which is less than 1% of the trap radius
The 200 by 300 micron diameters of the preferred trap design were chosen to be similar to those of current operating circular devices, which have been used for research in quantum electrodynamics (Phys. Rev. Lett. 76, 2049, 1996) as well in the first quantum logic gate experiment (Phys. Rev. Lett. 75, 4714, 1995). The phonon frequencies in these traps have been measured to be about 5-10 MHz, from which one can reliably calculate elliptical trap phonon frequencies of about 1 MHz. Note that this is a factor of 10 to 100 higher than for previous linear ion traps, which permits quantum computation this much faster.
The quantum channels for coupling between registers can be realized either by phonons or by photons. The photon coupling is preferable, because of a greater channel speed.
The photon coupling preferably uses an architecture similar to that of the prior art shown in FIG. 5. An optical cavity is constructed, having a resonant optical mode which overlaps two ions belonging to different elliptical traps. This can be accomplished physically in several different geometries. The simplest is the 3-mirror arrangement of FIG. 13, containing two concave mirrors below the plane of the traps and one flat mirror above. The concave mirrors create a gaussian mode in the cavity. Their radii of curvature are chosen to produce a spot size at the ions of several microns, significantly less than the ion--ion spacing, so that only 1 ion in each trap is illuminated.
Each ion of the coupled pair is also illuminated by a control laser beam, as in FIG. 6. When a certain temporally overlapping pulse shape is applied to the two control laser beams, the wavefunctions of ions 1 and 2 will be interchanged, forming a quantum communication channel, as discussed above and in the literature. The small trap sizes possible with microfabricated planar traps permits small spacing of the mirrors which leads to a small mode volume. Mode diameters of about 5 microns and mirror spacings of 1 mm lead to mode volumes<30 microns 3 . This is small enough to ensure "vacuum Rabi frequencies">1 MHz, which as noted above, yield data transfer rates of this order.
The novelty of the invention consists, first, of the use of many small ion traps in a parallel architecture, as contrasted to the above-discussed prior art which uses one large ion trap in a serial architecture. A quantum computer in accordance with the invention preferably uses one ion trap per quantum bit, and employs several hundred or more traps for a whole computer. Second, the architecture according to the invention is made practical by the invention of microfabricated arrays of elliptical ion traps. This microfabrication permits the manufacture of hundreds of traps more efficiently that the construction by hand of a single linear ion trap. Third, quantum information is transferred between ion traps using an optical coupling. This coupling is possible only due to the small size of the microfabricated traps. Conventional ion traps are so large by comparison, with dimensions in the millimeter range, that their optical cavity quantum channels become inefficient and lose quantum information, creating computer errors.
While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims. | A parallel architecture of quantum logic gates and quantum communication channels is provided for a quantum computer, thereby achieving advantageous efficiency and computation speed. The architecture of the invention enables parallel memory operations on large quantum words, and permits the application, to the quantum case, of parallel algorithms for mathematical operations such as addition and multiplication. The invention also includes a novel apparatus for realizing parallel architecture using an array of miniature elliptical ion traps, with as many traps as there are bits in a quantum word. The ion trap array preferably uses an elliptical planar geometry, which can microfabricated by photolithography. Quantum information is transferred from one ion trap to another by either an optical coupling via a high finesse resonant cavity (photon coupling) or by electrostatic coupling of the ions' mechanical motion (phonon coupling). | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a motor boat transom protector, and more particularly to a yieldable guard which can be configured to conform to the outline of the sternboard of a motor boat to isolate the sternboard from a motor mounted thereon.
Outboard marine motors are conventionally mounted on the transom of a boat via clamps including hand operated, threaded screws mounting relatively hard metal pads which bear against the inside surface of the transom. When the motor is to be mounted, the screws are unturned to retract the pads to positions removed from the sternboard permitting free movement of the pads relative to the sternboard. When the motor is properly positioned on the sternboard, the screws are turned to force the pads to bear against the transom surface and mar the finish. During use of the boat and motor, vibration will sometimes cause the threaded screws to partially unturn and thus move the pads out of snug engagement with the transom. The thus loosened, vibrating pads will sometimes scratch the transom surface.
Accordingly, it is an object of the present invention to provide a new and novel guard which will protect the transom from being marred by a motor mounted on the transom.
It is a further object of the present invention to provide a motor boat transom guard including a pliable sheet of material having opposite end sections, and an intermediate sheet section, joined to the end section, urging the end sections to inoperative positions in which they lie in the same plane, but permitting movement thereof to the confronting positions in which they bear against the inner and outer surfaces of the transom.
Another object of the present invention is to provide a transom protector which will conform to the outline of transoms having differing thicknesses.
Still another object of the present invention is to provide a guard of the type described including bend facilitating slits at the junction of the legs and the base to enhance bending movement of the legs relative to the base, to conform the guard to the shape of the transom.
Yet another object of the present invention is to provide a transom protector of the type described including mechanism for retaining the legs along opposite sides of the transom when the motor is being installed or removed.
If the motor and boat are subjected to substantial shock and vibration, as sometimes occurs, when the motor and boat are trailer-transported over long distances, for example, the screws unturn and the pads become loose from the transom. If the trailer which mounts the boat and motor negotiates a substantial bump in the road, the motor will sometimes be propelled off the transom. Likewisely, if the pads are not sufficiently secured to the transom when the boat is in the water and the submerged motor propeller strikes a submerged article, the motor will sometimes be forced upwardly off the transom and into the water. Accordingly, a further object of the present invention is to provide a transom protector of the type described which will inhibit inadvertent removal of the motor from the boat.
A still further object of the present invention is to provide a motor boat transom protector of the type described which includes downwardly inwardly coverging surfaces against which the pads will bear.
Another object of the present invention is to provide a transom guard of the type described including internally projecting ribs which bear against the transom to inhibit sliding movement of the guard on the transom.
Other objects of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.
SUMMARY OF THE INVENTION
A guard for protecting a motor boat transom having generally upstanding inner and outer faces spanned by a top surface comprising a pliable sheet of material having opposite end sheet sections for bearing against the inner and outer faces of the transom and an intermediate sheet section joined to the end sections, urging the end sections to inoperative positions in which they lie in the same plane, but permitting movement thereof to confronting positions adapted to bear against the inner and outer surfaces of the transom.
The present invention may more readily be understood by reference to the accompanying drawings, in which:
FIG. 1 is a top plan view of a motor boat transom guard constructed according to the present invention, part of the guard being broken away to more clearly illustrate the retaining stays therein;
FIG. 2 is an underplan view of the guard illustrated in FIG. 1;
FIG. 2A is a sectional end view, taken along the line 2A--2A of FIG. 2;
FIG. 3 is a sectional side view, taken along the line 3--3 of FIG. 1;
FIG. 4 is an enlarged sectional end view illustrating the guard mounted on a transom;
FIG. 5 is a sectional end view, similar to FIG. 4, illustrating slightly modified guard mounted on the transom of a boat; and
FIG. 6 is a sectional side view, similar to FIG. 3, illustrating the slightly modified construction illustrated in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Transom protector apparatus constructed according to the present invention, generally designated 10, is mounted on a sternboard, generally designated 8 (FIG. 4), including an inner surface 9 and an exterior surface 11. Referring now more particularly to FIGS. 1-4, the transom protector 10 includes a composite sheet of initially, generally planar material, generally designated 12, having an intermediate sheet section, generally designated 14, integrally joined to end sheet sections 16 and 17. As illustrated in FIGS. 1 and 2, the intermediate sheet section 14 is generally rectangular, whereas the end sections 16 and 17 are trapezoidally shaped and include outwardly converging, lateral side edges 18. The construction of sheet 12 may be similar to a conventional motor vehicle tire construction and includes laminated, outer and inner layers 20 and 22 which may suitably comprise rubber or other resilient material having a plurality of longitudinally extending, threads 25 such as nylon, embedded therein for added rigidity and strength. The layers 20 and 22 may be heated to a suitable temperature and fuzed together or, if desired, they may be coupled together via a layer 23 (FIG. 2A) of suitable epoxy. If desired, the sheet 12 may comprise a one piece molded rubber construction without laminations.
The inner layer 22 comprises a face, generally designated 24, including a plurality of longitudinally disposed, laterally extending teeth 26, each having a longitudinally inner surface 28, which is generally perpendicular to the plane of the sheet 12, and a longitudinally outer inclined surface 29. The surfaces 28 and 29 converge outwardly and terminate on opposite ends of a planar tooth surface 31. It should be noted that the tooth surfaces 29 at opposite end sections 16 and 17 are oppositely inclined. The tooth faces 28 and 29 are joined to planar tooth faces 31 at a plurality of laterally extending, longitudinally spaced edges 36 and 38 which bear against the inner and outer sternboard faces 9 and 11 to inhibit sliding movement of the protector 10 when it is mounted on the stern 8 as viewed in FIG. 4. The intermediate section portion 14a of sheet 22 includes a plurality of longitudinally spaced, laterally extending slits 30, along the outer surface 32, which expand from the closed positions illustrated in FIG. 3 to the open position illustrated in FIG. 4 when the protector 10 is installed on the stern 8.
The layers 20, 22, which comprise resilient material, such as rubber, yieldably urge the legs or end portions 16 & 17 to the positions illustrated in FIG. 3 in which they lie in the same plane.
A laterally central longitudinally extending, deformable metal strip 34 is positioned between the layers 20, 22.
When the protector 10 is to be mounted on the transom 8, the shape of the protector is changed from a generally planar shape to a generally inverted U-shape. To accomplish this change of shape, the legs or end portions 16 and 17 are forced downwardly relative to the intermediate portion 14 to the generally parallel positions illustrated in FIG. 4 abutting opposite side surface 9 and 11 of the sternboard 8. When the guard 10 is in the position illustrated in FIG. 4, the endmost slits 30a enhance the bending of the layer 20 around the uppermost corners 40 of the sternboard 8. When the legs 16 and 17 are moved to parallel positions, the metal strip 34 is deformed from the planar position illustrated in FIG. 3 to the inverted U-shaped position illustrated in FIG. 4. When the metal strip is thus deformed, the metal sets in the deformed condition and resists return movement of the resilient material 20, 22 to the positions illustrated in FIG. 3.
If a sternboard 8 has a lesser width than the width of the sternboard illustrated in FIG. 4, the inner slits, such as illustrated at 30b, will assist longitudinally inner portions of the intermediate section 14 to bend around the sternboard corners 40.
In the position of the protector illustrated in FIG. 4, the teeth 26 of leg 16, which bear against the outer surface 11, will be inclined to inhibit upward movement of the protector 10. The teeth 26 on the opposite end, or leg 17, which bear against the inner sternboard surface 9, will also be inclined so as to inhibit upward movement of the protector 10 on the sternboard 8. The strip 34 functions to retain the protector 10 when a marine motor, schematically designated 42, is mounted on the guard 10 mounted on the sternboard 8.
The motor 42 includes a propeller 44 mounted on a conventional drive shaft 46 which conventionally depends to a level below the water surface. The marine motor 42 is mounted on the sternboard 8 via a suitable clamp, such as illustrated at 48, including a pair of spaced apart legs 50 and 52. One or more thumb screws 54 are threadedly received in the leg 50 and each universally mounts a relatively hard, metal pad 56 which bears against the outer guard surface 32. A thumb operated handle 58 is mounted on the opposite end of the screw 54 as usual.
The resilient layers 20, 22 will protect the surface 9 and 11 from being marred by the pads 56 when the screws 54 are turned so as to tightly clamp the pads 56 to the guard 10 mounted on the sternboard 8. In the event that the screws 54 inadvertently unturn, the pads 56 will bear against the layer 20 and will not mar the surface 9.
ALTERNATE EMBODIMENT
Referring now more particularly to FIGS. 5 and 6, a slightly modified guard 110 is illustrated and is similar in many respects to the guard or protector 10 illustrated in FIGS. 1-4. Generally similar parts will be identified by generally similar numerals preceeded by the digit 1. In the embodiment illustrated in FIGS. 5 and 6, the leg or end portion 117 includes a beveled or tapering surface 132 which converges longitudinally outwardly toward the inner surface 124 of layer 122. The thickness of the longitudinally inner portion of leg 117 is substantially greater than the thickness of the terminal end portion. In the embodiment illustrated in FIGS. 5 and 6, the inner surface 124 of layer 122 includes a plurality of rectangularly shaped ridges or projections 128 which present a plurality of outwardly projecting teeth for bearing against the inner and outer surfaces 9, 11 of the sternboard 8. In the embodiment illustrated in FIGS. 5 and 6, the upper edges 156a of pads 156 will bite into the surface 132. In the event that the screw 154 unturns, the pads 156 are not tightly applied, and the pads 156 tend to move upwardly, the edges 156a will dig into the surface 132 and inhibit upward movement of the motor. In the event that the propeller shaft 46 hits an underwater barrier or the like, force will be transmitted up through the shaft 46 tending to pull the clamp 48 and motor 42 upwardly. As the unit tends to move upwardly, the upper edge 156A will bite into the outer surface 132 of leg 17, inhibiting upward movement.
It is to be understood that the drawings and descriptive matter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the scope of the appended claims. | A guard for protecting a boat transom from being marred by a marine motor mounted on the transom, comprising a generally U-shaped marine motor mounting protector, adapted to be mounted on the transom, including a base and a pair of legs mounted on the base for extending along the sides of the transom to provide a barrier between the transom and any motor to be mounted on the transom. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates to the provision of user-related data between devices over a data network. The invention has particular application in the provision by a user of personal data to an application running on a remote computer.
BACKGROUND OF THE INVENTION
[0002] For commercial transactions conducted over data networks such as the Internet, particularly in web-based transactions, it is frequently necessary for a user to provide personal information and transaction-related information (such as credit card details) to the organisation with whom a transaction is being conducted.
[0003] Typically, a user will access a web site posted by the organisation with whom the transaction is being conducted (referred to for simplicity as the “retailer”). When making a purchase, the user is presented with a form containing various fields (such as first name, last name, various address fields, credit card number and expiry date). The user fills in the requested information and submits the form. The application hosting the website captures the information from the various fields and uses this information to process the order and bill the customer. This process is tedious for the user and can result in errors being generated.
[0004] An additional problem with this method of conducting transactions is that the user may not necessarily have all of the required information to hand. Even if the information is stored on the user's computer, the user may wish to conduct the transactions from a shared computer, or from a computer which the user has never before used (such as a computer in an “Internet cafe”).
[0005] These difficulties are not limited to users of personal computers, since facilities exist for users to conduct network-based transactions from other network devices such as mobile telephones (including WAP phones) and personal digital assistants (PDAs).
[0006] Furthermore, the problems are not confined specifically to commercial transactions involving payments made by users. The same difficulties in filling in form fields are encountered in many situations by Internet users, such as when registering with providers of various services and information, and when submitting requests for information.
[0007] Additional difficulties may arise for users who are conducting transactions on behalf of their employer or their company, since in such cases, it is necessary for the individual user to have the requisite corporate information, including financial and billing information requested by the retailer, readily to hand, and user's are less likely to know the user details of their employer than their own personal details.
[0008] Parallel problems are encountered when the user is not connected directly to the web site over the Internet. For example, individuals who wish to purchase commodities (e.g. tickets) by telephone are often required to dictate the relevant details to an operator who then performs the data entry task into an application hosted by the retailer. Similarly, in situations such as a guest checking into a hotel, the guest will either dictate his or her details to the hotel receptionist, or will manually fill in a form, following which the receptionist enters the details into the hotel check-in system. This type of data entry is even more problematic, as language difficulties may arise, and because the user has no direct control over the information being submitted.
[0009] The disadvantages outlined above can lead to increased costs and delays for all parties involved in transactions, and can also mitigate against the attractiveness of conducting transactions using the methods outlined.
[0010] The present invention has as an object the provision of improved methods of providing user-related information to third party computer applications, and the provision of improved systems and computer programs for use in the above situations.
SUMMARY OF THE INVENTION
[0011] The invention provides a method of transferring data relating to a user between two data processing devices over a communications network. The method involves the following steps:
[0012] a) the first device receives a request for data from the second device, with the request identifying one or more pre-defined data elements (e.g. name, address, credit card number) which the second device requires;
[0013] b) the first device accesses a file containing data relating to the user. The data in the file includes a number of data elements identified by identifiers, and the first device retrieves one or more of the data elements identified in the request; and
[0014] c) the first device forwards the retrieved data elements to the second device.
[0015] The method of the invention enables the user to store the commonly requested data elements in a single location, and to allow the device (e.g. a personal computer, mobile phone, PDA, or a web server of a trusted third party) to handle requests for data automatically, identifying the particular items requested, retrieving the items, and sending them on to the requesting party. This eliminates the time involved in repeatedly entering the same data into a number of different web sites or other data entry systems, and also eliminates the potential for mistakes in typing or transcription of words or numbers.
[0016] Preferably, one or both of the two devices mentioned above are computers, but they can be any suitable data processing devices connected to one another on a data network.
[0017] In one embodiment, the file is stored on the first device. It could however be stored elsewhere provided the first device has access to it.
[0018] In one particularly useful application of the invention, the request is in the form of a web page having one or more fields for receiving data elements, and the identification of the pre-defined data elements is in the form of machine-readable tags accompanying the one or more fields.
[0019] Thus, the computer code which is passes from a web site to a user's PC, allowing the user's PC to display a web page, could include additional identifiers, such as the code “<firstname>” beside a field where the user inserts his or her first name. This allows the user's PC to identify the nature of the data item to be inserted, and therefore tells the PC that this item is to be retrieved from the file containing the user's details. Alternatively, the PC browser might be set up with the intelligence to deduce from the wording of the page which the user sees, that the user's first name is required at a particular point (in the same way that humans can identify that their first name is required on a form even though the form may have different ways of indicating that this is the data required).
[0020] Preferably, if tags are included in the request, the first device retrieves from the data file those data elements having identifiers which correspond to the tags in the request. The tags in the request and identifiers in the file need not be identical, provided that the device can correlate the information stored with that requested.
[0021] The invention is advantageously implemented by a browser engine operating on the first device which adds the retrieved data elements to the web page and presents the web page including the added data elements to a user before forwarding the data elements to said second device. In other words, it is envisaged that the browser engine (the software providing the functionality of a web browser) will not only retrieve the data requested but will also fill in the form and send the data in the same way as if the user had typed the data on screen.
[0022] The browser engine preferably provides the user with the option to confirm the submission of the data before forwarding the data to the second device.
[0023] The browser engine will preferably also provide the user with the option to vary the data elements before forwarding the data elements to the second device. This might be useful if the user wants to provide a different e-mail address to different companies.
[0024] The first device may log the submission of the data elements to the second device, to keep track of which parties have been given which data.
[0025] This feature allows the browser to update the data held by particular sites if the user changes some of the stored data. For example, if the user were to move house, the browser could notify the new address to any sites which had stored the old address (as could be determined from the log). This could be done automatically after the details are changed, or upon the next visit to the site. The user could veto particular sites from obtaining changes of details also, such as to prevent a new email address from obtaining junk e-mail or “spam”.
[0026] In an alternative embodiment, the first device is a server which stores the data on behalf of the user. Thus, a single “data provider” might store details for many users, and handle all data requests relating to those users. This is particularly useful in that it does not tie the user to using his or her own machine, since interested parties looking for data can be directed by the user to the data provider from any machine, e.g. if the user is in an Internet cafe and wishes to purchase goods over the Internet.
[0027] Normally, it will be desirable, for added security in such cases, for an additional step of verifying with the user that the data should be forwarded to the second device.
[0028] The user may be connected to the network by a device which is physically remote from the first device. Thus, the data server (first device) could be in a different country, and the user could connect to the Internet from a new location, or using a different type of device to that normally used (a WAP phone rather than a desktop PC for example).
[0029] Suitably, in such cases, the user uses a third device to access a web page hosted by the second device (web server), and the user directs the second device to forward its data request to the data server in order to supply the information requested on the web page.
[0030] This can be done by the user providing the second device with the network address of the first device. A URL or an IP address could be used.
[0031] Preferably, the data server generates a verification request to the user in response to the data request being received from the second device.
[0032] This verification request could be conducted using a different channel. For example, a user in an Internet cafe might receive an SMS text message on his or her mobile phone from the data server, to which he or she must respond before the data is released to the requesting (second) device.
[0033] Preferably, however, the user is connected to the network by a third data processing device, and the verification request is passed from the data server to the user's networked device via the web server or other second device.
[0034] Thus, a user accessing an on-line ticket seller from an Internet cafe might direct the seller to the data server's web address for the data to be supplied. The data server in response sends to the user, via the seller, a request for verification (e.g. to input a PIN), and only a successful response by the user to the seller (and from there to the data server) would enable the release of data.
[0035] In an alternative scenario, the user may be based at the second device and the verification is accomplished by means of an interaction between the user and the second device.
[0036] Thus, the user need not be on-line at all. For example, the user could supply a hotel receptionist with access to the necessary data to check in to the hotel, by directing the receptionist's PC to the data server, and verifying his or her identity on the hotel PC.
[0037] Preferably, the user interacts with the second device at least partially by means of an ID device held by the user and an ID device reader connected to said second device.
[0038] The ID device may be selected from a magnetically readable data carrier, an optically readable data carrier, a carrier containing an integrated circuit on which an identification is stored, a device operable to transmit electromagnetic signals to an ID device reader, and a mechanically readable data carrier.
[0039] The ID device may carry a network address of the first device in machine readable format.
[0040] The ID device could also or instead carry a network address of the first device in human readable format.
[0041] The ID carrier can contain information effective to identify the user to the first machine. Thus, a magnetic strip on a card held by the user might encode a URL for the data server, and an ID number or username relating to the individual user.
[0042] In a further aspect the invention provides a computer program product which causes a computer (or other device) to transfer data relating to a user over a communications network by:
[0043] a) receiving over the network a request for the data, the request including an identification of one or more pre-defined data elements for which the request is made;
[0044] b) accessing a file containing data relating to the user, the file including identified data elements and retrieving from the file one or more of the data elements identified in the request; and
[0045] c) forwarding over the data network to another computing device the retrieved data elements.
[0046] The program preferably further includes instructions to implement a web browser having this enhanced capability. However, it could simply be a “plug-in” or an upgrade for an existing browser, or it might run independently of a browser (e.g. on a data server or PDA).
[0047] If in the form of a browser, the request can be in the form of a web page having data entry fields and the browser can then identify the data elements required for the fields from tags included in the web page.
[0048] For data server programs, the instructions may be further effective to cause the server to identify the user from a number of users and to effect an authentication procedure requiring input from the user before forwarding the data elements.
[0049] The invention also provides a computer program containing instructions which when executed cause a computing device (“the second device”) to:
[0050] a) receive from a remote computing device (“the third device”) an instruction identifying the network address of a further remote computing device (“the first device”);
[0051] b) issue a request for data to the first device, wherein the request including an identification of one or more pre-defined data elements for which the request is made; and
[0052] c) receive from the first device one or more of the identified data items.
[0053] In the examples mentioned above, this latter program will be the one which runs on the web server, enabling it to direct data requests to the data server.
[0054] This program may cause the second device to forward the data items received from the data server to the user, and await confirmation that the data items are valid.
[0055] The invention provides yet a further computer program containing instructions which when executed cause a computing device to:
[0056] a) receive as an input a network address of a remote computing device;
[0057] b) forward to the network address a request for data relating to an identified user;
[0058] c) receive from the remote computing device data relating to the user; and
[0059] d) utilise the data in a transaction with the user.
[0060] This type of program could be run on a hotel PC or the call centre computer system of a telephone ticket seller. The network address could be input manually, or using an ID card held by the user. Alternatively, it could be sent by the user to a call centre using DTMF tones on from a telephone keypad. Yet again it could be sent from a mobile phone or PDA in proximity to the system operating with electromagnetic radiation (e.g. Bluetooth technology).
[0061] The invention provides, in a further aspect, a method of obtaining data from a user of a web site, the method including: providing a web page which includes a request for data relating to the user, in which the request includes a machine readable identification of one or more data items required to complete the transaction. The web server then receives from the user one or more of the data items thus identified, such that a data processing device associated with the user can provide the requested data items from a stored file containing data relating to the user organised by data item identifiers.
[0062] The invention also provides an information transfer system having:
[0063] a) a communications network;
[0064] b) first and second data processing devices connected to the network;
[0065] c) a storage unit associated with the first device and containing a number of data items relating to a user, in which the data items are organised by data item identifiers;
[0066] d) a computer program associated with the first device which causes the first device to
[0067] i) determine from a request received from the second device an identification of one or more data items for which the request has been made;
[0068] ii) retrieve available data items from the storage unit; and
[0069] iii) transmit the data items to the second unit.
[0070] The information transfer system may also include a third data processing device connecting the user to the network, and a computer program associated with the second device which causes the second device to:
[0071] a) receive an instruction from the third device identifying the network address of the first device, and
[0072] b) transmit the request to the first device upon receipt of the instruction.
[0073] The invention also provides a web site including a web page containing a request for data relating to a user of the web site, in which the web page includes a machine readable identification of one or more pre-defined data items included in the request.
[0074] The invention provides, in addition, a web site hosted by a web server on a data network, the web site including a web page containing a request for data relating to a user of the web site, in which the web page includes an option selectable by a user to cause the web server to direct a request for data to a remote computer identifiable by the user.
BRIEF DESCRIPTION OF DRAWINGS
[0075] The invention will now be illustrated by the following descriptions of embodiments thereof given by way of example only with reference to the accompanying drawings, in which:
[0076] [0076]FIG. 1 is a simplified architecture of the system of the invention;
[0077] [0077]FIG. 2 is a web page containing a form for the submission of data items by a user;
[0078] [0078]FIG. 3 is a flow chart detailing the operation of an embodiment of the invention
[0079] [0079]FIG. 4 is the web page of FIG. 2 in which the data items relating to the user have been entered according to the invention;
[0080] [0080]FIG. 5 is a more detailed flow chart of the verification process used in the flow chart of FIG. 3; and
[0081] [0081]FIG. 6 is a flow chart detailing the operation of a further embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0082] [0082]FIG. 1 shows a data network, more particularly the Internet 10 having a number of computers 12 , 14 , 50 , 52 , 64 , 86 connected thereto, the functions of each being described further below.
[0083] A user at a PC 12 runs browser software to access a web site hosted by a server 14 . The operation of such browsers to access remotely hosted web pages on the World Wide Web via the Internet is of course well known.
[0084] For the purposes of the following discussion it is assumed that the web site accessed by the user is the commercial web site of an airline conducting web-based ticket sales. However, this is exemplary only and a wide range of connected devices over as data network can take advantage of the invention as will be become fully clear.
[0085] Users of the web site are typically required to enter the following personal details before a transaction can be processed: Last Name, First Name, Street Address 1, Street Address 2, Town/City, Zip Code, State/Country, e-mail Address and Telephone Number. They are also required to enter the following financial information: Credit Card Number, Credit Card Type, Credit Card Expiry Date, and Name Appearing on Credit Card. Users must of course also enter details of the dates, times and airports for the flights requested.
[0086] A web page or form 16 requiring the input of this information is shown in simplified format in FIG. 2. The “personal details” referred to above are indicated generally at 18 on the left of the page, and the “financial details” are indicated generally at 20 on the upper right of the page.
[0087] A user would normally enter the required information in sections 18 and 20 of the form 16 , before pressing the “OK” button 22 to submit the data to the web server 14 . However, it can be seen that the web page 16 provides a further alternative, namely the option to “Add Details Automatically”, indicated by button 24 .
[0088] This option has two sub-options associated with it, namely to add details from the user's local browser, (option 26 ) or to add details from a remote server (option 28 ). In the present instance the user is at his or her own PC, and so the option 26 of adding from the local browser will be described first.
[0089] The user's browser has additional functionality which embodies the invention. Upon installation of the browser (or at any later time, using the “set-up” program to customise the browser), the user is presented with the option to store commonly requested details (or “data items”), such as those requested in the fields of web page 12 . The browser then stores these data items in a user details file, with the various data items tagged by means of a set of standard identifiers. Such a details file might read as follows:
<File Start> <Tag_Namefield1> <John> <Tag_Namefield2> <Doe> <Tag_ShipToAddressfield1> <1 The Oaks> <Tag_ShipToAddressfield2> <> <Tag_ShipToAddressfield3> <Anytown> <Tag_ShipToAddressfield4> <Alaska <Tag_ShipToAddressfieldzip> <12345> <Tag_BillToAddressfield1> <JohnD Electrical> <Tag_BillToAddressfield2> <100 High Street <Tag_BillToAddressfield3> <Anytown> <Tag_BillToAddressfield4> <Alaska> <Tag_BillToAddressfieldzip> <12356> <Tag_EmailAddressfield1><jdoe@jdelectrical.com> <Tag_workphone> <123 456 7890> <Tag_Homephone> <123 456 1234> <Tag_CreditCard> <1234 1234 1234 1234> <Tag_CreditCardExp> <0502> <Tag_MiscInfo1> <Social Security number 12345567> <Tag_MiscInfo2> <Tag_MiscInfo3> <File End>
[0090] The file format here is based on an XML or HTML style of associating tags with data, but the invention is by no means limited to such file types. The data will in practice be stored in encrypted form so that third parties who might gain access to the computer will not be able to access the details without a password, for example.
[0091] Other details could equally be stored, and in practice, the invention will be enhanced by having a wider range of data items than those listed above. Additionally one could store more than one user profile on a machine, so each member of a family, for example, might have a personal file, or a user might have a personal file and a business file.
[0092] Referring now to FIG. 3, one can see the steps followed by a user visiting the web site. The page is loaded into the user's browser in the normal way, step 30 . If the user decides at step 32 to complete the fields manually, the ensuing procedure is exactly as in known web site interactions, step 34 . However, if the user chooses the option to add details automatically in step 32 , and decides to do so from the local browser, step 36 , the browser parses the HTML file (or other file) underlying the web page, step 38 , to determine the existence of pre-defined tags identifying standard information to be inserted into some or all of the data fields.
[0093] In this regard, the HTML code of the web page is modified relative to conventional HTML code by the addition of identifier tags in the page which identify the data items (e.g. first name, credit card number, etc.) which are required to correctly fill the form on the page. These tags (the format of which will be determined in advance) are interpreted by the browser engine to cause the engine to open the details file and retrieve therefrom the data items contained in the details file for which tags have been included in the HTML file. It is of course possible that the details file will not include all of the requested details (e.g. if the user does not want to store a credit card number on his or her PC). However, those data items which have been requested are retrieved from the details file or database step 40 .
[0094] The browser then inserts the data items into the blank fields in the web page visible to the user, step 42 , as shown in FIG. 4. In accordance with common practice, some or all of the credit card number may not be displayed in section 20 , although in this case the user can see the final four digits to ensure that the correct card number will be debited.
[0095] The user then has the option to confirm, step 44 , that the data is correct by choosing the “OK” button 22 . The web page is submitted in the same manner as if the fields had been filled in manually, step 46 , including the use of encryption or secure connections to protect privacy. If any of the fields are mandatory and have not been filled in by the browser, the user may correct this before submitting the form, or in response to an error message, step 48 . In order to keep track of the identity of the web sites which have received the data items, the user's browser also maintains a log file which is updated, step 50 with each submission of data by the browser from the user's details file.
[0096] The log file also enables the browser to update the personal details held by any site previously visited in the event that the user changes e.g. credit card number or address. This can be done in the background immediately after the user updates the details file in response to any changes in circumstances, or it can be done on the next visit to the site. The user can opt to be notified of any such updates to details held by web sites, since the user may not necessarily want the web sites to obtain updated credit card details unless conducting a transaction on the site.
[0097] While the process has been described above in relation to a conventional PC connected to the Internet, the same process could be used by any data processing device on a data network having the capability of storing data items with identifiers. Thus, for example, mobile phones and PDAs with the requisite memory and processing power could equally be used to provide a user's personal details to a remote machine.
[0098] In an alternative implementation of the invention the user need not submit details held on the browser of the user's computer. For example, the user may wish to register with or conduct a transaction with a web site when away from his or her own PC. As an example, a user might access the web site from a shared computer on a network, which does not contain a details file for the user in question, or from a PC located in a so-called “Internet cafe” where users obtain access from a machine 50 (FIG. 1) which they may never have previously used.
[0099] In such cases, the user has the option of directing the web site to obtain the relevant data from a remote data server 52 to which the user's details have been previously submitted. The data server will typically store the details of a large number of users on a dedicated database 54 .
[0100] The user pre-registers with the data server and fills in the data requested by the data server in much the same way as described above in registering details with the browser loaded on a user's PC, although the pre-registration with the remote data server 52 will generally be done over a secure Internet connection.
[0101] The owner of the remote data server may charge a fee or receive some other benefit in return for storing the user's data and dealing with requests as described below.
[0102] If the user opts to “Add Details Automatically” in step 32 (FIG. 3) and selects the option to employ a remote server, step 54 , the network address of the remote server will be filled in by the user, in the space provided for this purpose in the web page at 28 . The user is prompted to enter a network address in the form of a Uniform Resource Locator or URL, which is a web address of the format www.[data server name].com (or .net, .org, .co.uk, etc.).
[0103] The URL entered by the user may include a particular file location which gives the remote data server the identity of the user whose details are requested. Thus each account holder might enter a personalised URL such as www.[data server name].com/johndoe. The URL is submitted by the user's browser, step 56 , to the web server 14 when the user clicks the button to add details from a remote server.
[0104] The web server then forwards a request for the user's data to the URL, step 58 , identifying the user either by the URL itself, as described above, or by means of a username obtained from the user. As a security measure, the data server may verify, step 60 that the web site is a trusted site, and may also require the user to confirm that the data should be sent to the web site by means of an independent verification described in FIG. 5.
[0105] Upon receiving the request the data server consults a registration database, step 62 , to ensure that the requesting site is a “trusted” site, according to whatever criteria appear to be appropriate in view of the requested information. This registration database is held on a registration server, together shown in FIG. 1 as 64 , and may be maintained by a registration organisation, although equally it could be maintained locally on the data server 54 itself.
[0106] If the site does not meet the verification criteria, then decision box 66 leads to an unsuccessful determination 68 .
[0107] If the site is trusted, then the data server sends to the web site an encrypted PIN request, step 70 . This encrypted request is passed in encrypted form to the shared PC 50 (FIG. 1), where it is deciphered. The user enters a PIN or verifies his or her identity in some other way, step 72 , and this encrypted response is sent, step 74 , via the web server to the data server. The data server verifies that the PIN is correct, step 76 and arrives at either an unsuccessful determination 68 or a successful determination 78 .
[0108] The user verification could be carried out in another way, such as by the user opening a new browser window, connecting to the data server, and sending a PIN directly to the data server without the involvement of the web site in handling the PIN request.
[0109] Alternatively, the user might be sent an email or an SMS text message to a mobile phone whose number is already known to the data server. The data server awaits a suitable response from the user before deciding on a successful determination and reaches an unsuccessful determination if a time-out period is exceeded without a valid user response being received.
[0110] Referring back to FIG. 3, if the verification is unsuccessful in step 60 , the user must complete the fields manually, step 34 . However, if there is a successful determination, the data server 52 accesses the details database 54 and retrieves the requested data items which are again identified from the request of the web site. It may be the case that the request is for all user data stored in respect of the user, or for particular groups of data items (e.g. if there is no financial transaction, the request might simply be in respect of name, address and e-mail address). Different web sites might be registered to obtain different levels of detail regarding the user.
[0111] The data server forwards a file containing the data items, step 80 , and the web server inserts the data items in the corresponding fields, step 82 , and presents the form with the data items to the user at the shared PC (FIG. 4), following which the user can edit and confirm the data in step 84 . Again, the user is presented with the opportunity to manually complete any missing mandatory data fields in step 86 , and the data server maintains and updates a log file, step 87 , recording the transfer of information to the web site.
[0112] The invention can also be implemented when the user needs to provide details such as personal and/or financial details to a third party for a computer application, even if the user is not directly accessing a computer on a data network such as the Internet. An example of this is when checking into a hotel, which has a PC 86 connected to the Internet (FIG. 1) running a check-in application.
[0113] The user wishing to check into the hotel provides the hotel PC 86 with information sufficient to enable that PC to make a data request to the data server in similar manner to that described for a user on a shared PC.
[0114] The invention can be implemented by the user carrying an ID device which may have the appropriate URL printed thereon, or preferably, stored thereon in machine readable format. Examples of such devices include magnetically readable data carriers, such as cards bearing a magnetic strip, optically readable data carriers, such as CD-type business cards, carriers containing an integrated circuit on which an identification is stored, such as so-called smart cards having an embedded chip, and devices operable to transmit electromagnetic signals to an ID device reader, such as mobile phones or other wireless devices communicating by means of Bluetooth technology. Other devices could also be used, including mechanically readable data carriers.
[0115] In the embodiment of FIG. 1, the hotel PC 86 has an associated magnetic card reader 88 which can read a magnetic strip encoding the URL and user ID of the user wishing to check in. The hotel PC runs the data entry application (check-in system), step 90 , FIG. 6. The user swipes his or her magnetic card in the card reader 88 , enabling the PC 86 to read the URL and user ID.
[0116] The PC then accesses the URL, step 94 , and requests the data items necessary for the check-in process to be automated as far as possible. With the request, step 96 , the PC sends an identification of the organisation requesting the information (merchant ID) and the user ID or username of the user whose details have been pre-registered with the data server, as previously described.
[0117] The data server can then optionally conduct a verification of the merchant ID as described above in relation to a web site verification, and the PC then, on behalf of the data server, requests a user PIN entry, step 98 . This PIN entry can be input on a keypad included in the card reader, step 100 (although other means can be included for the user to verify that the data request should be answered, such as using SMS messaging, as previously described).
[0118] The data server then decides whether the PIN verification has passed or failed in decision box 102 . If the result is a fail, the user can complete the check-in process in the conventional way, step 104 . Otherwise, step 106 , the requested data items are retrieved from the user's details file in the database 54 , and sent to the merchant's PC. The data file retrieved by the hotel PC is parsed and the retrieved data items are entered by the hotel PC in the check-in system, step 108 .
[0119] Although described in relation to a hotel check-in procedure, a similar system can also be used for airline reservations and check-ins, or for any of a wide range of commercial transactions or other interactions in which it is necessary for a person or organisation to pass details to another person or organisation. Particular examples include the passing of data needed to complete transactions over the telephone, such as when buying tickets, or registering for competitions. In such cases, a user could read out a URL, or a number corresponding to an Internet address to an operator. For example, URLs are resolved by domain name servers into Internet network addresses which may be of the form 123.456.78.9 (with, in most cases at present, a maximum of three digits in each field separated by periods). Any such address can be uniquely quoted as a 12 digit number using leading zeroes, e.g. 123456078009, thereby directing the merchant to a website containing all of the user's relevant details. The user might also quote a personal ID number.
[0120] Alternatively, the relevant numbers could be input to a telephone handset by pressing the digits in question, which would be transmitted as DTMF tones and automatically processed by an Interactive Voice Response system. While less complicated than a simple card swipe, the use of such technology to pass details to a third party is still less prone to error and less time consuming than a user having to dictate, and an operator having to transcribe, the numerous details which may be required even for a simple transaction, particularly if there are language barriers or misunderstandings.
[0121] The invention is not limited to the embodiments described herein which may be varied without departing from the spirit of the invention. | A method of passing data relating to a user between first and second devices on a network, in which the first device automatically retrieves data relating to the user from a file in which the data is held as a plurality of data items identified by data item identifiers. The first device receives a request from the second device and the request identifies one or more pre-defined data items. The first device then retrieves the requested items and forwards these to the second device. The invention has particular application in completing frequently requested information in a web page, with the data being held on the user's own PC or on a remote data server. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to a route planning system provided with various interlinked facilities, including a user I/O facility, a route planning facility, a position determination facility, and a destination table facility, for under control of a set of start and/or destination requests from a user person generating a route plan to be traveled.
PCT International Patent Application No. WO 93/09511, PCT US92/08104, in particular page 4, discloses a system for in specific manners directing respective drivers that may have various personal preferences such as to prefer quiet driving versus fast driving, and congested routes versus non-congested routes. Although the prior art system helps to choose the actual route whilst accommodating to a user person's wishes, actual planning of the travel, especially in a broader environment such as a company travel planning system, should also know actual traveling times in advance. It has been found that all existing route planning systems will only output a “best” route. The inventor of the present invention has recognized that personal driving habits represent a very relevant parameter that should be taken into account for the route planning, such as in the spatial as well as in the temporal domain. In the spatial domain certain driver categories may need another optimum route than others. In the temporal domain, differences in actual traveling time may cause variations in traveling schedules, such as when having various persons attending a single meeting at a pre-specified time instant.
BRIEF SUMMARY OF THE INVENTION
In consequence, amongst other things, it is an object of the present invention to provide a route planning system that allows to assess driver's past habits as additional data for the planning. Now, therefore, according to one of its aspects the invention is characterized in that said system furthermore comprises a driving habit assessment facility for assessing a particular user person's driving habits as additional input data for said route planning facility for on the basis of averaging said user person's driving habits selectively co-controlling said generating.
The invention also relates to a method for operating a route planning system as claimed in claim 1 . Further advantageous aspects of the invention are recited in the dependent claims.
DESCRIPTION OF THE DRAWINGS
These and further aspects and advantages of the invention will be discussed in more detail hereinafter with reference to the disclosure of preferred embodiments, and in particular with reference to the appended figures that show:
FIG. 1 shows an overall diagram of a system according to the invention; and
FIG. 2 is an applicable flow chart.
DETAILED DESCRIPTION OF THE INVENTION
The invention allows navigation systems that inter alia can estimate traveling times between two or more locations to improve this estimating through assessing the driving habits of a particular driver. This allows a more accurate prediction of an expected traveling time. In certain situations, this may relieve the requirements for taking into account time margins in the planning of traveling schedules, and thus effect a saving in time. For such assessing, the present invention would not need to ask a user additional explicit questions, such as a preference for fast, versus slower but scenic routes. Such asking is not covered by the present invention, but could instead be used as additional determinative input information.
Present-day route planning systems will often operate in two steps: first the optimum route is determined, followed by estimating the traveling time as based on average speeds that appear relevant on a particular road category. For example, a multi-lane motorway will generally allow much higher speeds than a two-lane rural road, that may also be used by numerous agricultural machines drawn by slow-moving tractors. However, individual drivers still may have widely ranging driving habits that may influence average speeds enormously.
Such habits could include the cruising speed that may further depend individually on various external parameters such as the time-of-day, a person's tendency to overtaking slow-moving vehicles, or the habit to prefer certain routes such as sneak-around routes, over other routes such as normal routes. The invention should allow to assess such individual habits for use in an improved schedule for predicting calculated traveling times. Furthermore, when a plurality of persons may use a particular car, such as a couple, or various personnel in case of a company car, the system should be able to recognize an actual user person. Such recognizing can be done in various manners, such as through user recognition on the basis of speech, or on the basis of a personal code, such as by keying or through entering a personal ID card.
The calculating of a traveling time prediction deteriorates with the actual user person deviating farther from the average user person's habits. Generally, many persons will keep more or less to standard speeds, such as 140 kms/hr on Motorways versus 40 kms/hour in built-up areas. However, many variations occur for old versus young people, men versus women, veteran drivers versus rookies, senior company executives versus junior apprentices, and many others that cannot be categorized.
The invention should allow the route planning system to have a more accurate estimation of the traveling time through assessing a user person's habits in a learning procedure. The necessary data can be acquired through speed sensors, in combination with the information of an actual route being traveled. The latter information would of course be provided by the route planning system itself through some localizing technique. This information so acquired can be averaged and inputted into the data base as a particular user person's driving idiosyncrasy. In principle, the learning curve can be made long, such as through covering many weeks or many thousands of kilometers. Alternatively, also quite recent elements of personal behavior can be taken into account, such as pertaining to a few days, or even that of the actually covered journey in a dynamic input for the route that actually has been planned. In principle, the short-time assessed information can be compared to long-time driving habits of the person in question, or of the driving community on the average, and differences presented to the user person, such as in the form of a warning message.
FIG. 1 shows an overall diagram of a system according to the invention, that by way of example has eleven subsystems, as follows. Block 20 symbolizes a user person who wants to be guided by the system. The user interfaces bidirectionally to the system's I/O that may have various hardware and software facilities such as keyboard, mouse, speech, other audio, and display. Block 32 represents an Institutional Data Base that may store various entries, such as representing hotels, restaurants or other facilities, together with associated data such as location, business hours, and actual services present at those facilities. Block 34 represents a Navigational Data Base that may comprise a road network, together with physical distances or travel time distances between representative points, road classification, and others. Block 36 represents a Position System that detects an actual position of the vehicle, such as through using a well known GPS system. Block 26 represents an Event Table, such as a road block or jam situation that has been communicated by a higher level authority such as a Radio Data System, and which event may cause a certain destination to be no longer reachable, or only in a delayed manner, or which may necessitate the vehicle to take a detour.
Block 28 represents a Destination Table that contains the destinations and associated timing indications, such as entered by the user through block 22 , and subject to information from the Travel Planning in block 24 , the Institutional Data Base in Block 32 , and the Event Table in block 26 . Block 30 represents a Navigational Computer that is fed with the Destination Table from block 28 , with the Navigational Data Base from block 34 , and with the Position from block 36 ; from this information it can figure out a route to be taken, which route may contain various interval points and furthermore, timing indications associated to the various Interval Points. Block 24 represents the Travel Planning that is fed by the information from the navigational computer 30 , and which block 24 furthermore bidirectionally interfaces to the Destination Table in Block 28 , and to the User I/O in Block 22 . The Travel Planning will update the Destination Table if it fails to find a correct solution for attaining all Interval Points, and it will signal the User what Route is to be taken, as well as will signal the above Failure to allow the user to modify the set of Interval Points and/or associated timing indications. The above represents a comprehensive car navigation system for the present invention, the items 30 , 34 , 36 , 38 , 40 are especially relevant, whereas certain others such as 32 may not always prove to be indispensable.
Now, a further input to the system in the present embodiment are one or more speed sensors 38 , that in the present system have not been used for by integration determining the actual position of the vehicle. The sensors measure actual vehicle speed that may be displayed to a driver or not. The speed so measured is presented to the navigational computer subsystem 30 that in consequence may associate a particular route or street or route category with the actually attained driving speed of the vehicle in question. The combined data are sent to the learning subsystem 40 that can associate a particular route or route category with an actual average speed attained over the route in question. If feasible, this average speed may be further specified for a time-of-day, character of the whether, or other feature, which feature may operate as an overlay over the particular driver's driving habits, or even be tailored to the particular driver's habits viz a viz this particular parameter. For example, motorway cruising speed may lie between 120 kms/hr and 200 kms/hr. Some persons will drive faster by night, while others tend to slow down. Many other variations are possible in an often unpredictable manner, absent the information of a particular person's driving habits. The learning system may furthermore receive appropriate information from the navigational data base and from the position determining system, as appropriate. The latter two may also present the category of the route actually being traveled. In subsequently estimating the traveling time, the learning system 409 will have stored data acquired thereby into the navigational data base, with the person's identity as a further qualifier. The recognizing of the user person's identity may ensue via user I/O subsystem 22 in a manner that has been suggested supra or otherwise, in a manner that by itself is not pertinent to the present invention.
FIG. 2 is an applicable flow chart of the operation of the route planning system according to the invention. In block 42 , the system is started, and the necessary hardware and software facilities are assigned. In block 44 , the system self-reliantly executes various tasks, such as for recognizing the user person. In block 46 , it checks for the presence of user requests. If absent (N), a waiting loop is executed. If all user requests will have been received (Y), the system in block 48 will access general information, such as for the geographical planning of the route. If ready, the system in block 50 will access such data as are specific for the user person in question, such as the speed attained on earlier journeys on roads of the same characterization, or even on the particular road in question. This will allow the system to estimate actual traveling time. In block 54 the result is presented to the user, such as by displaying an actual schedule. If this is not O.K. (n), a signalization in case by the user will drive the system back to block 46 , such as for adding or deleting a destination location. If O.K. (Y), the journey is assumed to be undertaken, and the system in block 56 monitors the progress. In doing so, the special data are updated, either as regarding the driver's average behavior or habits, or as regarding the driver's instantaneous behavior on this particular day or route. This may lead to updating the overall information for the driver, or even the best route for the day's journey. For clarity, an associated route through the flow diagram has been omitted, as having various other features, that be themselves are not deemed necessary to disclose the general nature and principle of the present invention. Upon arriving at the end of the journey, yes in block 60 , the system goes to block 62 that terminates the operation at least for the time being. Otherwise (N), the monitoring proceeds.
The person skilled in the art of route planning will recognize further policies to be followed within the ambit of the present invention, the scope of which has justfully been determined by the appended claims hereinafter. For example, the time calculation may be done for different possible routes that for the average driver will have nearly equal travel times, but where the particular driver would need more time for either a first road of the pair, or the second one. This would then influence the outcome of the route planning in the spatial domain. | A route planning system is provided with various interlinked facilities, including a user I/O facility, a route planning facility, a position determination facility, and a destination table facility. Under control of a set of start and/or destination requests from a user person a route plan to be traveled is generated. In particular, the system further includes a driving habit assessment facility for assessing a particular user person's driving habits as additional input data for the route planning facility. On the basis of averaging the user person's driving habits the route generation is influenced in the time domain and/or in the spatial domain. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method, a terminal and a router for detecting a trigger to rerouting, and more particularly to a method, a terminal and a router for detecting a trigger to rerouting for controlling an alteration of redundant routing.
2. Description of the Related Art
In the conventional packet exchange control system (GPRS) standardized under the 3rd Generation Partnership Project (3GPP), a manner of controlling the rerouting of a communicating mobile terminal when it has moved is differentiated with the type of radio channel between the mobile terminal and the base transceiver station during call. That is, available radio channels between the mobile terminal and the base transceiver station are classified into “dedicated channels” on which the volume of communication traffic is heavy and “common channels” on which the traffic volume is light. On the dedicated channel, the radio network controller (RNC) used at the time of initial establishment of communication is used as the anchor. And control to extend the route of data from the anchor (subscriber line extension) is performed. On the common channel, the Gateway GPRS Support Node (GGSN) is used as the anchor, from which routing is switched to the shortest cut from there to the mobile terminal (SRNS relocation (SRNS=Serving Radio Network Subsystem)) is performed. (Reference: 3G TS 25.832 “Manifestations of Handover and SRNS Relocation”.) This rerouting control is performed when the mobile terminal moves from one RNC to another (inter-RNC handover), but this rerouting control is not performed when the mobile terminal moves from one base transceiver station (BTS) to another in the territory of the same RNC (intra-RNC handover). In an intra-RNC handover, the route from the RNC to the BTS can be switched by soft handover, but that at a higher level than the RNC (between the RNC and the GGSN) cannot be switched.
When a mobile terminal performs an inter-RNC handover under the conventional rerouting control by GPRS, optimal rerouting can be accomplished if the radio channel is a common channel, but if it is a common channel, the subscriber line extension entails the occurrence of a redundant portion on the route, resulting in wasteful use of network resources. Moreover, as the choice between subscriber line extension and optimal rerouting solely relies on whether the radio channel is a dedicated channel or a common channel, even if an inter-RNC handover takes place, subscriber line extension may be chosen (if the volume of traffic drops in this state and a shift to a common channel occurs, a change to optimal routing will take place upon that shift), there is a disadvantage that the redundant routing resulting from the movement of the mobile unit cannot be optimized on a real time basis. Furthermore, although SRNS relocation is permitted under the 3GPP standard specifications even when operating on a dedicated channel, essentially SRNS relocation (or subscriber line extension) is a technique that is made feasible by the capability of the network to keep track of whether a mobile terminal has moved from one RNC to another. In a usual IP network, as there are many different topologies including a mesh structure and a tree structure or the like and the structure can usually be altered as desired, it is not realistic for the network to manage the structure, and it is impossible to apply the 3GPP specifications as they are.
FIGS. 7 illustrate how the conventional system works, namely how routing is altered where a mobile communication terminal M under GPRS shifts its position. FIG. 7A shows a case in which the radio channel between the mobile communication terminal M and the base transceiver station is a common channel, and FIG. 7B , a case in which the radio channel between the mobile communication terminal M and the base transceiver station is a dedicated channel. A GGSN 1 in FIG. 7A is a gateway GPRS support node, positioned at the gateway to the network where there is a server or a terminal which is to become a communication partner 8 with the mobile communication terminal M. Communication between the mobile communication terminal M and the communication partner 8 takes place via this GGSN 1 . An SGSN 2 is a Serving GPRS Support Node (SGSN), which is connected to the GGSN 1 and is the switchboard nearest to the mobile communication terminal M. An RNC 3 is a radio network controller having functions to control radio resources and to control the handover when the mobile communication terminal M has shifted its position. BTSs 41 to 44 are base transceiver stations, and the mobile terminal carries out communication through connection to one or another of these BTSs.
Where the radio channel between the mobile communication terminal M and the base transceiver station is a common channel as shown in FIG. 7A , the communication path between the mobile communication terminal M and its communication partner 8 is switched from a route R 1 to a route R 2 , which is the shortest cut, with the GGSN 1 as the starting point along with a shift, represented by an arrow Y 3 , of the mobile communication terminal M. However, where the radio channel is a dedicated channel as shown in FIG. 7B , subscriber line extension takes place whereby, starting from an RNC 31 which was on the communication path when communication was begun, a route R 3 is extended toward an RNC 32 and a BTS 43 , which are the destinations of the shift, in the direction represented by an arrow Y 4 , of the mobile communication terminal M (a route R 4 ). This system is used to restrain any data loss that may arise when the communication path is switched by a handover, but a more redundant route shown in FIG. 7B will arise, compared with the optimal (shortest) route (the route R 2 in FIG. 7A ).
Thus under GPRS, even at a timing at which rerouting for optimization is required, the rerouting method is selected solely dependent on the state of the radio channel, resulting in a disadvantage that routing cannot be optimized on a real time basis in response to a handover of the mobile communication terminal M.
Conceivably, this problem could be addressed by either (1) invoking the procedure of change-over to the optimal route upon every handover of the mobile terminal or (2) invoking the same upon an inter-RNC handover.
However, the method of (1) may invoke a wasteful procedure because an intra-RNC handover would need no optimization of routing (the handover would give rise to no redundant route). The method of (2) is unrealistic because managing the structure of a usual IP network, such as the one mentioned above, is difficult to manage and accordingly it is difficult to determine whether or not a given RNC is an “inter-RNC”.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method, a terminal and a router for detecting a trigger to rerouting for providing on a real time basis a trigger to anchor router (hereinafter abbreviated to “AncR”) reselection by constantly comparing during communication the number of hops required for the routing of a data packet from the communication partner of a mobile terminal to the mobile terminal.
A method of detecting a trigger to rerouting is characterized by including a comparative step of comparing the respective numbers of hops arising at terminals in data transmission and reception arising between the terminals, and an optimizing step of achieving optimization, if the result of comparison at the comparative step indicates that the number of hops in later data transmission and reception is greater, by altering the routing so as to reduce the number of hops.
By comparing the numbers of hops on the route, any redundancy on the route can be detected according to an increase in the number of hops, and the route can be optimized on that basis.
In various embodiments discussed below, routing in the transmission and reception of the data is accomplished with at least one of a plurality of routers relaying the data serves as the anchor, if the number of hops in later data transmission and reception is found greater as the result of comparison at the comparative step, the router to serve as this anchor (anchor router) is altered at the optimizing step.
The numbers of hops between transmission terminal transmitting data and reception terminal receiving the data are compared at the comparative step, and the routing is altered at the optimizing step according to the result of comparison at the comparative step.
As the numbers of hops are compared and a rerouting instruction is issued on the part of a specific party to communication, the optimal rerouting can be accomplished without having to grasp the overall situation of the communication network including the identification of the source of redundancy as the shift of the own terminal or that of the other party to the terminal or any other factor.
The number of hops of the currently received data at the reception terminal and the number of hops of the immediately preceding received data at the reception terminal are compared at the comparative step, and routing is altered at the optimizing step so as to reduce the number of hops if the result of comparison at the comparative step reveals that the number of hops of the currently received data is greater than the number of hops of the immediately preceding received data.
By monitoring the number of hops every time data are received, the optimal rerouting can be accomplished on a substantially real time basis while the mobile terminal is engaged in communication.
The number of hops is acquired by acquiring on the basis of parameters in data, the parameters being modified by routers which are passed between the transmission terminal and the reception terminal during the time they communicate, the variances between the values of the parameters at the starting point of counting and the values of the parameters at the ending point of counting, and identifying the number of routers corresponding to those variances.
This makes it possible to acquire the number of hops in data reception. Further by using parameters contained in the data, it is made possible to acquire the number of hops on a substantially real time basis along with the transmission and reception of data and without having to perform any special control over the communication of parameters.
The parameters are initialized at the starting point, and the variances can be acquired on the basis of the resultant initial values.
This makes it possible to acquire the number of hops accurately.
A terminal according to the invention includes an acquiring unit which acquires the number of hops and an issuing unit which issues, if the number of hops currently acquired by the acquiring unit is greater than the number of hops acquired in the past, an optimizing instruction to alter routing to the other terminal to reduce the number of hops and optimize it, it being so arranged that an external apparatus having received the instruction optimizes the inter-terminal routing.
A router according to the invention includes an acquiring unit which acquires the number of hops and an issuing unit which issues, if the number of hops currently acquired by the acquiring unit is greater than the number of hops acquired in the past, an optimizing instruction to alter the inter-terminal routing to reduce the number of hops and optimize it, it being so arranged that an external apparatus having received the instruction optimizes the inter-terminal routing.
The router may further include a receiver unit which receives the number of hops acquired by another apparatus in the past, wherein the issuing unit issues, if the number of hops currently acquired by the acquiring unit is greater than the past number of hops acquired by the receiver unit, an optimizing instruction to alter the inter-terminal routing to reduce and optimize it, and an external apparatus having received the instruction optimizes the inter-terminal routing.
The router may further include a transmitter unit which transmits the number of hops acquired by the acquiring unit to an external comparator which detects any increase in the number of hops in the inter-terminal communication on the basis of the acquired number of hops.
An embodiment of a router of the invention includes an initializing unit which initializes parameters in data modified by a router installed between the terminals for the communication of data to identify the number of hops, wherein the variances of said parameters matching said number of hops can be acquired on the basis of the resultant initialized values.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of a method of detecting a trigger to rerouting according to the present invention;
FIG. 2 illustrates how routing takes place if the method of detecting a trigger to rerouting according to the invention is applied to a case in which a correspondent node (CN) is in another network;
FIG. 3 illustrates how routing takes place if the method of detecting a trigger to rerouting according to the invention is applied to a case in which a CN is in the own network;
FIG. 4 is a block diagram of the configuration of a terminal for use in an implementation of this method;
FIG. 5A is a block diagram of a configuration of an access router for use in the implementation of this method; FIG. 5B , a block diagram of a configuration of an access router for transmitting the number of hops to an access router at the destination of shifting; and FIG. 5C , a block diagram of a configuration of an access router for receiving the number of hops from an access router in the position before the shift;
FIG. 6 is a block diagram of a configuration of a router for use in the implementation of this method; and
FIG. 7A illustrates how routing takes place if a radio channel between a mobile communication terminal and a base transceiver station is a common channel in a conventional GPRS system; and FIG. 7B , how routing takes place if the radio channel between the mobile communication terminal and the base transceiver station is a dedicated channel in the conventional GPRS system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, equivalent elements in different drawings are denoted by respectively the same reference signs.
Embodiment 1
FIG. 1 is a flow chart of a method of detecting a trigger to rerouting according to the present invention.
At step S 101 in FIG. 1 , transmission and reception of data between specific terminals is monitored.
At step S 102 , if transmission and reception of any data was detected at step S 101 , the number of routers the data have passed from the time they were transmitted from one terminal by the time they are received by another terminal, which is the communication partner, i.e. the number of hops, is acquired.
At step S 103 , the number of hops acquired at step S 102 is compared with the number of hops acquired by earlier transmission and reception of data than at step S 101 . If this comparison reveals a greater number of hops at step S 102 , i.e. that the shift of the communicating terminal in the meantime has made the routing redundant, the process goes ahead to step S 104 .
At step S 104 , rerouting is carried out so as to reduce the number of hops.
FIG. 2 illustrates how routing takes place if the method of detecting a trigger to rerouting according to the invention is applied to a case in which a correspondent node (CN), with which a mobile terminal communicates, is in another network (hereinafter referred to as the other network) than the network to which the mobile terminal belongs (hereinafter referred to as the own network).
A CN 8 in this case may be a mobile terminal connected to the other network or any other terminal or a server. AncRs 51 and 52 are routers present on the route between the mobile communication terminal M and the CN 8 , and communication takes place via them. The AncR 51 in Embodiment 1 usually is likely to be a router present on the boundary between the own network and the other network. The AncR 51 further has a function to capsulate a data packet destined from the CN 8 for the mobile communication terminal M when it passes and to transmit it to the mobile communication terminal M and a function to set in that data packet the initial number of hops in the form of combining consciousness with an access router (AR). RTs 61 and 62 are usual routers (RTs) present in the network. ARs 71 through 74 are routers present at one end or another of the network, and the mobile communication terminal M connects with the AR 72 among them and engages in wireless communication with the AR 72 .
FIG. 2 shows a situation in which the mobile communication terminal M is already connected to the AR 72 before a handover. The routing of a data packet from the CN 8 to the mobile communication terminal M then consists of a route R 5 via the AncR 52 . The data packet from the CN 8 is capsulated by the AncR 52 , and the number of hops is initialized and transmitted to the mobile communication terminal M. The AR 72 detects from the received data packet (destined for the mobile terminal) the number of hops required between the CN 8 and the AR 72 on the basis of the initial number of hops set by the AncR 52 , and stores that number.
When the mobile communication terminal M shifts to under the command of the AR 73 as indicated by an arrow Y 1 and a handover takes place, immediately after the handover it is routed via a route R 6 because it is still communicating via the AncR 52 . At the time of this handover, information regarding the number of hops of the reception data of the mobile communication terminal M, acquired and stored by the AR 72 , is succeeded and stored by the AR 73 . The optimal (shortest) path then is a route R 7 , and the route R 6 would be a redundant path for routing from the CN 8 to the AncR 51 via the AncR 52 . Then the AR 73 compares the number of hops between the CN 8 and the AR 72 at the AR 72 via the route R 5 , succeeded from the AR 72 , with the number of hops between the CN 8 and the AR 73 detected when on the route R 6 , and detects an increase in the number of hops.
Triggered by this detection, the AR 73 invokes control to optimize the route, i.e. to reselect an AncR. In the state shown in FIG. 2 , as the route using the AncR 51 as the relay node is the shortest cut, control to select the AncR 51 as the relay node is invoked. A number of ways of AncR reselection control are conceivable, including direct notification by the AR 73 to the CN 8 that the subsequent communication will take place via the AncR 51 , and a request by the AR 73 to the AncR, another router or mobile terminal to notify the CN 8 of the reselection. After the AncR reselection, the routing is changed to the route R 7 having the AncR 51 as its relay node, resulting in a switch to the optimal route. Various specific means are conceivable for handing over the data of the number of hops from the AR 72 to the AR 73 in this embodiment, including direct transmission of the data from the AR 72 to the AR 73 , transmission of the data via another node (router) in the network, and transmission of the data via the pertinent mobile terminal.
Embodiment 2
FIG. 3 illustrates how routing takes place if the present invention is applied to a case in which a CN is in the own network.
There is shown a situation in which, in the initial state, the mobile communication terminal M is connected to the AR 77 and the CN 8 , to the AR 76 , and the data routing from the CN 8 to mobile communication terminal M uses an RT 63 as the AncR. Therefore, the data routing from the CN 8 to the mobile communication terminal M in the initial state uses a route R 8 . In this case, too, as in Embodiment 1, the data destined from the CN 8 to the mobile communication terminal M are capsulated and the initial number of hops is set at the RT 63 , which is the AncR, and the AR 77 detects from the reception data the number of hops between the CN 8 and the AR 77 and stores it.
When the CN 8 hands over here the command to the AR 75 as indicated by an arrow Y 2 , immediately after the handover the data routing from CN 8 to the mobile communication terminal M runs via a route R 9 because the AncR still is the RT 63 . As the optimal route then is the route R 10 , the path from the RT 62 to the RT 63 is redundant for the route R 9 . Then, the AR 77 detects the redundancy of routing by comparing the number of hops obtained from the reception data from the CN 8 , and invokes control to optimize the route (reselect an AncR). Since the optimal AncR then is the RT 62 , the control to change the AncR to the RT 62 is invoked. For reselection control then, a number of ways are conceivable as described above with reference to Embodiment 1. After AncR reselection to use the RT 62 , the routing runs via the route R 10 , resulting in a switch to the optimal route.
Specific parameters to be used in calculating the number of hops according to the invention include, for instance, a Time To Live (TTL) in IPv 4 and a hop limit parameter in IPv 6 .
Further, regarding the functions and operations of an AR according to the invention, a mobile communication terminal can also have the same functions and operations as the AR except the AR before the mobile communication terminal shifts to hand over the received number of hops that has been acquired to the AR to which the shift was desired for and the AR to which after the mobile communication terminal shifts to receive and store the number of hops received before the shift. Thus, the object of the invention is also attained when the mobile communication terminal acquires the number of hops, compares the currently acquired number of hops with the number of hops acquired in the past and issues an instruction to change the routing to another terminal is changed when the comparison reveals the current number of hops to be greater than the past number of hops.
In order to realize the method described above, the terminal can be configured as shown in FIG. 4 , or the access router configured as shown in FIG. 5 (A to C), and the router configured as shown in FIG. 6 .
Thus, as illustrated in FIG. 4 , the terminal M comprises a number of hops acquiring unit M 1 and a command issuing unit M 2 . The number of hops acquiring unit M 1 acquires, every time it receives data as indicated by an arrow Y 6 , the number of hops needed for the reception of the data. The command issuing unit M 2 issues an instruction to change the routing to another terminal is changed when the number of hops received by the number of hops acquiring unit M 1 proves greater than the number of hops acquired in the past.
Alternatively, an access router 7 may comprise a number of hops acquiring unit 7 A, a transmitter unit 7 B, a command issuing unit 7 C and a receiver unit 7 D as shown in FIG. 5A . The number of hops acquiring unit 7 A has similar functions to those of the number of hops acquiring unit provided on the terminal. The receiver unit 7 D receives the number of hops transmitted from another access router 7 . Thus, when the terminal has shifted as described above, the access router 7 to be connected to that terminal will change. In this case, by receiving the past number of hops to be compared with from the access router 7 connected before the shift and making comparison, any redundancy in the routing after the shift can be detected. The transmitter unit 7 B transmits, when the terminal under the command of the access router shifts as described above, the number of hops acquired in data communication immediately before the shift, to the other access router 7 which is to compare the number of hops. The command issuing unit 7 C compares the number of hops acquired by the number of hops acquiring unit 7 A or received by the receiver unit 7 D, and issues an instruction to on the basis of the result of comparison as described above. FIG. 5B illustrates the minimum configuration the access router 7 requires when a terminal under its command has shift, and FIG. 5C , that the access router 7 requires when a terminal has been newly connected under its command. Thus, the access router 7 a terminal under whose command has moved out transmits the number of hops acquired by the number of hops acquiring unit 7 A through the transmitter unit 7 B. The access router 7 under whose command a terminal has been newly connected receives through the receiver unit 7 D the number of hops before the shift, transmitted by that access router 7 , i.e. the past number of hop, acquires the current number of hops through the number of hops acquiring unit 7 A, and compares the current and past numbers of hops using the command issuing unit 7 C. Whereas any redundancy in routing can be detected in this manner, in practice an access router 7 of a configuration shown in FIG. 5A is installed in the network.
As shown in FIG. 6 , a router 9 includes an initializing unit 9 A for setting initial values for parameters in data. The parameters are initialized first and then undated by a router installed between terminals engaged in communication of data to identify the number of hops. These parameters are the hop limit parameter and others as mentioned above. By initializing the number of hops at the router 9 , especially the anchor router where the counting starts, having the access router or the like to acquire that parameter perceive the initial value, and acquiring the number of hops on the basis of the variance from the initial value, the number of hops can be acquired accurately.
As hither to described, because an AR or a mobile terminal detects the number of hops from data received in communication and stores it, compares it with the number of hops in new received data and thereby provides a trigger to reselection according to the present invention, eventually it can switch to the optimal route on a substantially real time basis while the mobile terminal is engaged in communication. Furthermore, as the invention can be applied irrespective of whether the communication partner is in another network or in the own network, and as it allows the detection of any redundancy in routing irrespective of the cause of redundancy, whether it is due to the shift of the own terminal, that of the communication partner or to any other factor, the resources in the network can be utilized more effectively by eliminating redundant routing. | Rerouting of packet exchanges by a mobile terminal is controlled so as to be optimized on a real time basis to prevent network resources from being wasted by redundant routing. In an initial state a route of data from a mobile communication terminal M to a CN 8 , which is a communication partner, is a route R 5 . Then, an access router (AR) 72 acquires the number of hops of data received from the CN 8 by the mobile communication terminal M. As the mobile communication terminal M now performs a handover to under the command of the AR 73 , the route will change to a route R 9 . Then the AR 73 detects that the route becomes redundant by the fact that the number of hops acquired after the shift is greater than the pre-shift number of hops received from the AR 72 , and invokes control to reroute to a route R 7 , which provides the optimal routing. | 7 |
This application is a continuation of application Ser. No. 591,540 filed Sep. 14, 1990 now abandoned.
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to a process for the preparation of a high-permittivity material, and more specifically to a process for the preparation of a high-permittivity material suitable for use as, for example, a microwave dielectric resonator or a substrate for a microwave integrated circuit.
2) Description of the Related Art
With increase of information contents through communications, communication means through microwave are rapidly advanced in fields of mobile telephone systems, satellite communications, satellite broadcasts and the like. Parts used in these communication means are required to enhance their performance, make their dimensions small and reduce their prices.
In this case, regarding microwave dielectric resonators making use of a ceramic material by way of example, the wavelength of the electromagnetic wave propagated through the interior thereof is shortened in proportion to 1/√ε r (ε r : relative dielectric constant) compared with that through air. Therefore, such resonators can be made in a small size compared with cavity resonators and hence have been extensively used in recent years. Besides, the ceramic material used therein has also been used as a substrate for microwave integrated circuits owing to its high relative dielectric constant and low dielectric loss.
A material for a microwave dielectric resonator must meet requirements such as a high dielectric constant, low dielectric loss and a low temperature coefficient of resonant frequency. As materials satisfying such requirements, there are known those of the BaO-TiO 2 type, SnO 2 -ZrO 2 -TiO 2 type, BaO-TiO 2 -Nd 2 O 3 type and complex perovskite type typified by Ba(Mg 1/3 Ta 2/3 )O 3 and Ba(Zn 1/3 Ta 2/3 )O 3 .
In general, dielectrics making separate use of the above-mentioned materials are sintered bodies obtained by a firing process under atmospheric pressure and hence have voids in their interiors in proportions of several % in terms of volume. In this case, the proportion of the voids contained inside the sintered body (void content) is affected by the firing temperature, the particle size of raw materials for the ceramic, impurities, etc. Therefore, the void content often varies depending upon the production lots and firing lots of a raw material. Even in the same lot, the values of the void content tend to vary depending upon the firing positions of the raw material because of temperature and atmosphere distributions in a kiln. Accordingly, it is difficult to obtain a dielectric having stable properties.
In the dielectric resonator on the other hand, its resonance frequency is determined by the dielectric constant of its material, and dimensions and configuration characteristic of its resonator. In this case, it is desirable that the dispersion in resonant frequency between dielectric resonators should be as small as possible. However, since there are variations of void content in the dielectric obtained in the above-described manner and the relative dielectric constant (about 1) of air present in the voids is very low compared with that (10-100) of the ceramic material, great dispersion in dielectric constant occurs and hence the resonance frequency is also dispersed widely, so that the yield of the dielectric resonators is reduced to a significant extent. In a microwave band, high accuracy for a desired resonance frequency is often required, in particular, of the SHF band (3 GHz or higher higher in frequency). There is hence a great problem therein. Therefore, in order to avoid such disadvantages, additional processes, for example, a process in which the dimensions of individual dielectrics are changed to fabricate resonators having the same resonance frequency, are required.
In the case of the substrate for a microwave integrated circuit on the other hand, its thickness must be made even in order to make the dispersion of characteristic impedance as to wiring smaller. In addition, since the wiring is composed of a thin film formed by sputtering, vapor deposition, plating or the like, the substrate must be polished prior to its use. In this case, when the voids present inside the substrate appear on the surface thereof to turn into pores, any minute patterns cannot be formed on the surface. In particular, when a material high in dielectric constant is used, a minute pattern must be formed due to the problem of characteristic impedance. Therefore, the presence of voids become a great problem.
As means for reducing the void content of a ceramic material, are known hot pressing and hot isostatic pressing (HIP). However, these methods are accompanied by great problems because ceramic materials for microwave dielectric resonators, which have been known to date, are all oxides.
Namely, with respect to the hot pressing, the firing temperature can be raised only to about 1,300° C. from the viewpoint of heat resistance of a jig. Therefore, materials allowed to fire at such a temperature are limited, and moreover such a method is not suitable for mass production, so that production cost becomes expensive. With respect to HIP on the other hand, a relatively large amount of the material can be treated. However, such a treatment is accompanied by a problem that since the treatment is principally conducted in a non-oxidizing atmosphere such as N 2 or Ar, ceramic dielectrics which are oxides are reduced when applying such a treatment thereto, so that the dielectric loss of the dielectrics is remarkably deteriorated.
SUMMARY OF THE INVENTION
A principal object of this invention is to provide a process for the preparation of a high-permittivity material in which the void content has been made low without any deterioration of the dielectric loss and the dispersion of the dielectric constant is small, thereby becoming effective in the SHF band of 3 GHz or higher.
Another object of this invention is to provide a process for the preparation of a high-permittivity material, which comprises:
Pre-firing a ceramic material under a predetermined pressure to obtain a sintered body; and then
subjecting the sintered body to a hot isostatic pressing treatment in an oxidizing atmosphere.
A further object of this invention is to provide a process for the preparation of a high-permittivity material, wherein the void content of the sintered body is controlled to 6% or less in the pre-firing.
A still further object of this invention is to provide a process for the preparation of a high-permittivity material, wherein the ceramic material is pre-firing under a pressure of 100 atm or lower.
A yet still further object of this invention is to provide a process for the preparation of a high-permittivity material, wherein powder obtained from a solution of a metal salt is used as the ceramic material.
A yet still further object of this invention is to provide a process for the preparation of a high-permittivity material, wherein the sintered body is subjected to the hot isostatic pressing treatment under a pressure of at least 200 atm, but at most 3000 atm.
A yet still further object of this invention is to provide a process for the preparation of a high-permittivity material, wherein the sintered body is subjected to the hot isostatic pressing treatment at a temperature ranging from -350° C. to +100° C. on the basis of the pre-firing temperature.
Other objects and advantages of the present invention will be readily appreciated from the preferred embodiments of this invention, which will be described subsequently in detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the present invention, a ceramic material is first of all pre-fired in a pressurized atmosphere up to about 100 atm, or under atmospheric pressure or reduced pressure. By this pre-firing, opened pores extending to the interior of the ceramic material are lost to form an airtight surface layer. Incidentally, although the opened pores are lost by the pre-firing, a considerable number of closed voids are present in the ceramic material. The thus-fired ceramic material is then subjected to a high-temperature and high-pressure treatment, i.e., HIP treatment, in an oxidizing atmosphere to decrease the closed voids, thereby preparing a ceramic material low in void content. In this case, the starting ceramic material must be compacted to a relative density of at least 94% in order to lose the opened pores by the pre-firing.
The above-described steps are conducted, for example, by separately using both kilns for pre-firing in a decompressed, normal-pressure or pressurized atmosphere and for the HIP. Needless to say, the pre-firing and HIP steps may be successively performed in an HIP apparatus.
Although those of the BaO-TiO 2 type, SnO 2 -ZrO 2 -TiO 2 type, BaO-TiO 2 -Nd 2 O 3 type and complex perovskite type typified by Ba(Mg 1/3 Ta 2/3 )O 3 and Ba(Zn 1/3 Ta 2/3 )O 3 may of course be mentioned as materials for microwave dielectric resonators, which may be used in Examples of this invention, those obtained by adding one or more additives to the above materials and hence having improved properties are also applied. In principle, all oxides can be applied so long as they are usable for microwave.
Any materials may be used as raw materials for individual components of the oxide ceramics so long as they are ordinary oxides and those finally converted into their corresponding oxides, such as carbonates. However, powders obtained from solutions of metal salts, namely, raw materials obtained by coprecipitation, or hydrolysis or spray pyrolysis of metal alkoxides are extremely preferred because of their high purities. In particular, since these powders are very fine particles, lower-temperature sintering can be conducted for them. By combining it with similar lower-temperature sintering expectable in HIP, the powders can be fired at lower temperatures. Therefore, materials liable to be reduced at elevated temperatures even in an oxidizing atmosphere can be fired at lower temperatures, and moreover a superstructure by which dielectric loss property can be improved in the above-mentioned complex perovskites also becomes more easily obtainable by lower-temperature firing.
For the oxide microwave dielectrics susceptible to the deterioration of dielectric loss due to reduction and deficiency of oxygen ions, the remarkable increase of the partial pressure of oxygen by the high-pressure firing brings about the following advantages. Namely, the occurrence of these defects can be prevented, the reduction of their qualities can be avoided, and moreover their properties can be improved.
Conditions of the HIP treatment vary depending upon the composition of a ceramic material, the particle size of powders as raw materials and the like. It is however desirable that the pressure should be at least 200 atm, but at most 3000 atm. Any pressures lower than 200 atm will be able to attain only a little effects. On the other hand, any pressures higher than 3000 atm will be too expensive as to the cost of equipment for withstanding such pressures in comparison with effects obtained.
The temperature of the HIP treatment desirably falls in a range of from -350° C. to +100° C. on the basis of the pre-firing temperature (usually, a firing temperature at which the powder is most compacted under atmospheric pressure). Any temperatures lower than the firing temperature -350° C. will be difficult to demonstrate the effect of the HIP due to low deformability of the ceramic material. Any temperatures higher than the calcining temperature +100° C. will result in a product having deteriorated properties due to overfiring.
COMPARATIVE EXAMPLE 1
After mixing 35.4 g of BaCO 3 , 64.6 g of TiO 2 and 0.2 g of MnCO 3 in a wet ball mill making use of a polyethylene pot and zirconia balls, the resulting mixture was filtered under reduced pressure and dried at 110° C. After the thus dried mixture was then fired at 1,000° C. in an air atmosphere, the thus-treated mixture was ground in a wet ball mill making use of a polyethylene pot and zirconia balls. The thus-ground mixture was further filtered under reduced pressure and dried at 110° C., followed by addition of an organic binder to granulate it to 40 mesh. The thus-granulated powder was pressed into disk in a steel die single-shaft dry powder-press molding under a pressure of 200 kg/cm 2 and then iso-static-pressed under a pressure of 1,200 kg/cm 2 . The resulting molded article was fired for 2 hours at 1,380° C. on a platinum plate in an oxygen atmosphere. The main crystal of the resulting sintered body was Ba 2 Ti 9 O 20 . This sintered body was machined into pieces of 7 mm in diameter and 3.5 mm in thickness.
The dielectric properties of the above sintered body at microwave were determined in accordance with the HakKi & Coleman method. As a result, its relative dielectric constant, ε 4 and Q (the reciprocal of dielectric loss, tan δ) were found to be 39.4 and 3,500, respectively, at about 10 GHz. Further, the sintered body was polished to observe it. Its void content was about 2% and the dispersion of the relative dielectric constant, ε r was about ±0.2 as determined as to 10 samples.
EXAMPLE 1
The sintered body obtained in Comparative Example 1 was subjected to an HIP treatment for 1 hour at 1320° C. and 1,500 atm in an atmosphere composed of 20 vol % of O 2 and 80 vol % of argon. Thereafter, the relative dielectric constant, ε r of the HIP-treated sintered body was measured and was found to be 40.6. The dispersion of the relative dielectric constant, ε r was ±0.1 or less. Besides, voids were scarcely observed.
EXAMPLE 2
Powder obtained by refluxing alkoxides of barium, titanium and manganese, which had been separately weighed so as to have the same final composition as that in Comparative Example 1, in alcohol as a solvent and then hydrolyzing them was fired at 900° C. After adding an organic binder to the thus-treated powder, the resulting mixture was molded by the same procedure as in Comparative Example 1. After the organic binder was removed at 900° C., the molded article was pre-fired for 2 hours at 1,320° C. on a platinum plate in an atmosphere composed of 20 vol % of O 2 and 80 vol % of argon, followed by an HIP treatment under 1,000 atm. This sintered body was machined into pieces of 8 mm in diameter and 4 mm in thickness.
The dielectric properties of the above sintered body at microwave were determined. As a result, its ε r and Q were found to be 40.5 and 3,200, respectively, at about 10 GHz. The dispersion of the ε r was ±0.1 or less. Besides, voids were scarcely observed.
COMPARATIVE EXAMPLE 2
A mixture of 55.1 g of BaCO 3 , 3.8 g of MgO, 41.1 g of Ta 2 O 5 and 0.1 g of MnCO 3 was treated in the same manner as in Comparative Example 1 except that the firing was conducted at 1,100° C. to complete the steps from the mixing to the molding. The thus-obtained molded article was fired for 3 hours at 1,520° C. on a platinum plate in an oxygen atmosphere. The main crystal of the resulting sintered body was Ba(Mh 1/3 Ta 2/3 )O 3 of a composite perovskite structure. The dielectric properties of the above sintered body at microwave were determined. As a result, its ε r and Q were found to be 24.5 and 7,200, respectively, at about 10 GHz. Besides, its void content was about 1.5% and the dispersion of the ε r was ±0.2 as determined as to 10 samples.
EXAMPLE 3
The sintered body obtained in Comparative Example 2 was subjected to an HIP treatment for 1 hour at 1450° C. and 1,000 atm in an atmosphere composed of 20 vol % of O 2 and 80 vol % of argon. Thereafter, the relative dielectric constant, ε r of the HIP-treated sintered body was measured and was found to be 25.3. The dispersion of the ε r was ±0.1 or less. Besides, voids were scarcely observed.
COMPARATIVE EXAMPLE 3
After weighing BaCO 3 , TiO 2 and Nd 2 O 3 to predetermined amounts, the mixture was treated in the same manner as in Comparative Example 1 to complete the steps from the mixing to the molding. The thus-obtained molded article was calcined for 2 hours at 1,350° C. in an oxygen atmosphere. This sintered body was machined into pieces of 9 mm in diameter and 4.5 mm in thickness. The dielectric properties of the above sintered body at microwave were determined. As a result, its ε r and Q were found to be 83 and 1,600, respectively, at about 6 GHz. Besides, its void content was about 2%. The dispersion of the ε r was ±0.3 as determined as to 10 samples.
EXAMPLE 4
The sintered body obtained in Comparative Example 3 was subjected to an HIP treatment for 2 hours at 1300° C. and 500 atm in an atmosphere composed of 20 vol % of O 2 and 80 vol % of argon. Thereafter, the ε r of the HIP-treated sintered body was measured and was found to be 85. The dispersion of the ε r was ±0.1 or less. Besides, voids were scarcely observed.
COMPARATIVE EXAMPLE 4
The sintered bodies described in Examples 1 through 4 were separately subjected to an HIP treatment under the same conditions as those in the above respective HIP treatments except that an argon atmosphere was used instead of the oxidizing atmosphere. In this case, the sintered bodies in all Examples were reduced and their Q values were lowered to a significant extent.
As has been described above, the high-permittivity materials obtained in accordance with this invention have a low void content, so that the dispersion of their dielectric constants is very small compared with any conventional preparation processes. Therefore, the dielectric resonators obtained by using the high-permittivity materials according to this invention are very small in dispersion of resonance frequency. It is hence possible to mass-produce dielectric resonators having uniform properties. In addition, since pores scarcely appear in the high-permittivity materials of this invention even after the polishing them, they are also optimum as substrates for microwave integrated circuits. | Disclosed herein is a process for the preparation of a high-permittivity material. The process comprises pre-calcining a ceramic material under a predetermined pressure to obtain a sintered body, and then subjecting the sintered body to a hot isostatic pressing treatment in an oxidizing atmosphere. The high-permittivity material is low in void content, is very small in dispersion of its dielectric constant and hence has excellent dielectric properties. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a prefabricated building assembly for efficient low cost fabrication of exterior walls, interior walls and roofs to form a building assembly.
[0003] 2. Description of Related Art
[0004] Many techniques have been utilized to reduce building costs associated with conventional building construction. Normally, conventional building construction involves a labor intensive process where skilled workers and laborers may pour a concrete foundation, assemble a wall and roof stud assembly, attach exterior and interior walls, assemble roof panels, and set and install windows and doors. On many occasions, the construction of the building may involve numerous contractors and subcontractors who are responsible for various stages of construction. Typically, delays ensue and construction costs escalate accordingly.
[0005] One of the existing techniques used to reduce construction costs involves the use of pre-fabricated modular type homes. Typically, modular homes involve the use of panels, which are shipped to a construction site and only require the connection of the pre-fabricated panels in order to construct the building. The use of pre-fabricated panels provides a less expensive and easily assembled building as opposed to the conventional construction methods. One drawback associated with modular buildings, modular homes tend to lack sufficient strength and durability for long-term use. Modular homes also tend to lack the necessary flexibility to accommodate various sizes and styles. Furthermore, some modular systems require the inclusion of traditional construction techniques in order to complete construction, therefore, escalating the reduced costs associated with modular homes.
[0006] U.S. Pat. No. 5,996,296 to Bisbee relates to a structural panels for a pre-fabricated building and a corresponding method that includes a plurality of space tubular steel columns, a pair of tubular steel girts each interconnecting respective ends of the columns and the plurality of space tubular steel cross members arranged in pairs, and connected on opposite sides of the columns in a registry with each other to accommodate various available building materials. The pre-fabricated structural panel of Bisbee addresses some of the strength and durability shortcomings of the prior art, however, the panels may still be costly to assemble and may be somewhat limited in use in regard to design and style.
[0007] U.S. Pat. No. 6,508,043 to Bond, et al. relates to a building construction system that is configured to comprise a modular, transportable construction kit type structure, which can be easily provided to a particular building site and has the capability of being expandable into a variety of different configurations depending upon the particular needs for a particular building. The building construction system of Bond includes vertical frame members that are used in conjunction with a plurality of corrugated material panels and a quantity of concrete. The building construction system of Bond attempts to address the cost and efficient construction associated with building construction. Furthermore, it attempts to provide a more sturdy and durable building than associated with the pre-fabricated modular homes of the prior art. The building construction system of Bond, however, still requires extensive labor, and therefore does not reduce costs sufficiently in order to provide a complete substitute for traditional construction methods.
[0008] Accordingly, a need exists for an improved modular panel assembly system, which truly addresses the shortcomings of the prior art. More specifically, it would be advantageous to have a pre-fabricated building assembly that allows for cost effective building construction, flexibility to accommodate various designs, and sufficient re-enforcement capabilities to provide durable building construction.
SUMMARY OF THE INVENTION
[0009] The present invention relates to a prefabricated building assembly capable of providing a swift, efficient and economic construction of exterior walls, interior walls and roofs to form a building assembly. The present invention includes interlocking prefabricated panels that may form a building assembly comprised of exterior walls, interior walls and a roof. The system may be assembled in its entirety, or the wall and roof system may be utilized independently of each other and adapted to include standard building materials (i.e. standard roof trusses, interior framing, exterior block walls).
[0010] The interlocking panels may be constructed primarily of expanded polystyrene components to build exterior walls, interior walls and an interlocking roof system for high insulation benefits and light weight. The wall components may consist of “H” blocks, “corner blocks” and “interlocking panels.” The building panels may be sized differently in length or height to accommodate the specifications of a given plan. Once erected, the walls having vertical voids in the wall system may receive steel rebar, be filled with a cementitious material and/or any other suitable matter. The interlocking roof panels are attached to each other to form a roof assembly and include channels that receive steel rebar and concrete that provide a means to adjoin to the wall assembly thus forming the building assembly. Mechanical and utility chases may be placed within the building assembly panels and standard building materials may be secured to the structure. Once completed, the entire surface area of the panels will be encapsulated with a cementitious mixture that bonds to the surface and enhances the structures impact resistance, rigidity and strength.
[0011] It is therefore an object of the present invention to provide a prefabricated building assembly necessary for construction of a building comprising: a plurality of exterior wall panels; a plurality of exterior connection blocks, the plurality of exterior connection blocks being capable of joining the plurality of exterior wall panels that form an exterior wall of the building; a plurality of roof panels, the plurality of roof panels forming a roof of the building; a plurality of interior wall panels; and a plurality of interior connection blocks where the plurality of interior connection blocks being capable of joining the plurality of interior wall panels that form at least one interior wall of the building.
[0012] It is also another object of the present invention, to provide a prefabricated building assembly necessary for construction of a building which includes exterior wall panels, exterior connection blocks, the exterior connection blocks being made to join the exterior wall panels that form an exterior wall of the building, roof panels that form a roof of the building, interior wall panels, and interior connection blocks capable of joining the interior wall panels that form at least one interior wall of the building. A polymer may be used to form the exterior wall panels, interior wall panels, exterior connection blocks, interior connection blocks and roof panels. A cementitious coating may be applied to the wall panels and connection blocks in order to bond the surface and to enhance the impact resistance, rigidity and strength.
[0013] In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1A shows a top plan view of an exterior wall panel according to the present invention.
[0015] FIG. 1B shows a front elevational view of the exterior wall panel according to the present invention.
[0016] FIG. 1C shows a side elevational view of the exterior wall panel according to the present invention.
[0017] FIG. 1D shows another side elevational view of an exterior wall panel according to the present invention for a 4/12 pitch roof.
[0018] FIG. 1E shows yet another side elevational view of the exterior wall panel according to the present invention for a 5/12 pitch roof.
[0019] FIG. 1F shows a perspective view of an exterior wall panel according to the present invention.
[0020] FIG. 2A shows a top plan view of an exterior H block according to the present invention.
[0021] FIG. 2B shows a top plan view of an alternative H block according to the present invention.
[0022] FIG. 2C shows a front elevational view of the exterior H block according to the present invention.
[0023] FIG. 2D shows a side elevational view of the exterior H block according to the present invention.
[0024] FIG. 2E shows another side elevational view of exterior H block according to the present invention with a roof pitch.
[0025] FIG. 2F shows a side elevational view of the alternative exterior H block according to the present invention.
[0026] FIG. 2G shows another side elevational view of the alternative H block according to the present invention.
[0027] FIG. 2H shows another side elevational view of the alternative exterior H block according to the present invention.
[0028] FIG. 3A shows a top plan view of the corner block according to the present invention.
[0029] FIG. 3B shows a top plan view of an alternative corner block according to the present invention.
[0030] FIG. 3C shows a side elevational view of the corner block according to the present invention.
[0031] FIG. 3D shows a second side elevational view of the corner block according to the present invention.
[0032] FIG. 3E shows a second side elevational view of the alternative corner block according to the present invention.
[0033] FIG. 3F shows a third side elevational view of the corner block according to the present invention.
[0034] FIG. 3G shows another third elevational side view of the corner block according to the present invention.
[0035] FIG. 3H shows another third side elevational view of the alternative corner block according to the present invention.
[0036] FIG. 4A shows a top plan view of an exterior wall panel of indeterminent length.
[0037] FIGS. 4B and 4C show top plan views of special spacers that may be used in the invention.
[0038] FIG. 5A shows a top plan exploded view of the use of the H block with the exterior wall panel according to the present invention.
[0039] FIG. 5B shows a top plan exploded view of a four-way block used in conjunction with the exterior wall panel according to the present invention.
[0040] FIG. 5C shows a top plan exploded view of a three-way block used in conjunction with the exterior panel according to the present invention.
[0041] FIG. 6A shows a front elevational exploded view of a window and sill/header panel according to the present invention.
[0042] FIG. 6B shows a side elevational exploded view of the window sill/header panel according to the present invention.
[0043] FIGS. 6C and 6D show side elevational views of exemplary headers of different pitches according to the present invention.
[0044] FIG. 7A shows a perspective view partially cut away of an exemplary roof panel according to the present invention.
[0045] FIG. 7B shows a perspective exploded view of a roof panel according to the present invention with the inclusion of insert connectors.
[0046] FIG. 8A shows a side elevational view schematically of joined roof peak according to the present invention.
[0047] FIG. 8B shows a different side elevational view of a roof peak just prior to joining the roof peak panels according to the present invention.
[0048] FIG. 9 shows an enlarged cut away side elevational view schematically of a gable roof peak according to the present invention.
[0049] FIG. 10 shows a front elevational view of an arch insert according to the present invention that can be used for building constructions.
[0050] FIG. 11A shows a front elevational view of an interior wall according to the present invention.
[0051] FIG. 11B shows a side elevational view of an interior wall according to the present invention.
[0052] FIG. 11C shows two a side elevational view of interior walls stacked according to the present invention.
[0053] FIG. 12A shows a perspective view partially exploded of the connection of two interior panels according to the present invention.
[0054] FIG. 12B shows a top plan view exploded of a connection of corner block with an interior wall panel according to the present invention.
[0055] FIG. 12C shows a top plan view of an interior wall panel and connection.
[0056] FIG. 13A shows a top plan view of the interior T block according to the present invention.
[0057] FIG. 13B shows a front elevational view of the interior T block according to the present invention.
[0058] FIG. 13C shows a right side elevational view of the interior T block according to the present invention as shown in FIG. 13A .
[0059] FIG. 13D shows a left side elevational view of the interior T block according to the present invention shown in FIG. 13A .
[0060] FIG. 14A shows a front elevational view of an interior wall panel connected to a header according to the present invention.
[0061] FIG. 14B shows a side elevational view of the connection of the header and interior panel according to the present invention shown in FIG. 14A .
[0062] FIG. 15A shows a front elevational view of an exemplary interior door with a door header and interior wall panels surrounding it.
[0063] FIG. 15B shows a side elevational view of the header interior wall connection.
[0064] FIG. 16A shows a top plan view of the interior corner block according to the present invention.
[0065] FIG. 16B shows a front elevational view of the interior corner block according to the present invention.
[0066] FIG. 16C shows a side elevational view of the interior corner block according to the present invention.
[0067] FIG. 17A shows a top plan schematic view of 45-degree angle connection block according to the present invention.
[0068] FIG. 17B shows a top plan schematic exploded view of an interior four-way block as it connects an interior panel according to the present invention.
[0069] FIG. 17C shows a top plan schematic exploded alternative embodiment interior wall connection according to the present invention.
[0070] FIG. 18A shows a front elevational view partially in cross section of perimeter wall fence according to the present invention.
[0071] FIG. 18B shows a top plan exploded view of the connection of perimeter walls according to the present invention.
[0072] FIG. 18C shows a side elevational view of the perimeter wall according to the present invention.
[0073] FIG. 18D shows a side schematic view detail of the footer associated with the perimeter wall according to the present invention.
[0074] FIG. 18E shows a top plan schematic view of the connection of the perimeter wall panels using an H block with a post according to the present invention.
[0075] FIG. 18F shows a front elevational view of a wood beam detail associated with the perimeter wall according to the present invention.
[0076] FIG. 18G shows a perspective cut away view of the wood beam detail according to the present invention.
[0077] FIG. 19A shows a side elevational schematic view of a flat ceiling detail according to the present invention.
[0078] FIG. 19B shows a side elevational schematic view of a barrow vault detail of a ceiling according to the present invention.
[0079] FIG. 19C shows a side elevational exploded view schematically of a header extension to the roof line according to the present invention.
[0080] FIG. 19D shows a top plan view partially cut away of an interior header detail according to the present invention.
[0081] FIG. 20 shows a top lan view schematically in cross section of a building assembly.
[0082] FIG. 21A shows a front elevational view of the building assembly before additional of a cementitious coating on the panel surfaces.
[0083] FIG. 21B shows a front elevational view as in FIG. 21A with the cementitious coating as a finished building assembly.
DETAILED DESCRIPTION
[0084] The present invention relates to a prefabricated building assembly for efficient low cost fabrication of a building structure. The present invention uses a number of components in a number of different configurations in order to meet any specifications associated with exterior walls, interior walls and wall panel systems for window and door openings. The present invention also includes interlocking panels designed to form a roof assembly that may complete the shell of the building structure.
[0085] FIG. 1A shows a top view of an external wall panel 10 according to the present invention. The exterior wall panel 10 includes two interlocking edges 11 a , 11 b and recess 14 . FIG. 1B shows a front view of the exterior wall panel 10 as can be seen from both FIGS. 1A and B, interlocking edges 11 a , 11 b extend outwardly from the external wall panel 10 and provide a means for interlocking the exterior wall panels to “H” blocks or corner blocks to form a complete wall for a building's exterior. FIG. 1C provides a side view of the exterior wall panel 10 and recess 14 which provides a means for insertion of steel and/or cementitious material. The top of the exterior wall 10 includes two lips 12 a , which form the recess 14 . As shown in FIG. 1C , the two lips 12 a are on the same plane. FIGS. 1D and 1E show the top lip portions of the exterior wall 12 b and 12 c which are pitched. Regardless of the lip position, the top recess 14 allows for the insertion of steel rebar and/or cementitious material. Ties may be used to connect rebar within the recess 14 with rebar found within the roof panels and/or ceilings and rebar protruding through the blocks from the slab. The pitched lips 12 b and 12 c of FIGS. 1D and 1E allow for the exterior panel 10 to abut against a gable style roof of different pitches. FIG. 1F shows the exterior wall panel 10 and interlocking edges 11 a and 11 b and recess 14 .
[0086] FIGS. 2A through 2H show two embodiments and associated views of an exterior “H” block which provides the interconnecting means for exterior wall panels 10 . FIG. 2A shows an exterior H block 20 a from a top view. The exterior H block 20 a includes two channels 25 a , 25 b with a cylindrical void 21 between the channels 25 a , 25 b . The channels 25 a , 25 b provide the space as a female fitting for the insertion of male interlocking rectangular edges 11 a , 11 b of the exterior wall panel 10 . The cylindrical passage or void 21 provides a space for insertion of a rebar and/or a concrete mixture in order to provide further support of the completed wall panel assembly. FIG. 2B shows an alternative exterior H block 20 b , which includes channels 25 a and 25 b as shown with the exterior H block 20 a . The exterior H block 20 b , however, includes a rectangular passage or void 23 that has a slot opening 27 on the channel 25 b . The exterior H block 20 b merely provides an alternative H block for the vertical insertion of rebar. FIG. 2C shows a front view of the exterior H block 20 a . FIGS. 2D and 2E show side views of the exterior H block 20 a . As can be seen in FIGS. 2D and 2E , exterior H block 20 a , 20 b includes a connection slot 24 and provides for two alternative top portions. The top portion of exterior H block 20 a , 20 b of FIG. 2D is similar to the top portion of 12 a of the exterior wall panel 10 . FIGS. 2F, 2G and 2 H show side views of exterior H block 20 b . Exterior H block top portion 22 a shows two substantially parallel lips that form connection slot 24 . Exterior H block top portion 22 b shows two pitched lips of the connection slot 24 . The slot 24 receives rebar and/or concrete. FIG. 2F has the exterior H block top portion 22 a with two substantially parallel lips forming connection slot 24 . FIGS. 2G and 2H show two alternative exterior H block tops 22 b and 22 c , which have pitched lips forming connection slot 24 . The exterior H block top portions 22 b , 22 c may be used to abut a roof of varying pitch according to the present invention.
[0087] FIGS. 3A through 3H show an exemplary corner block 30 a and 30 b according to the present invention. FIG. 3A shows corner block 30 a that includes channels 33 a and 33 b on two adjacent sides of the corner block 30 a and a cylindrical void 31 through the middle of the corner block 30 a . The channels 33 a , 33 b provide space to receive the extended male portions of the exterior wall panels 10 and cylindrical void 31 provides a space for the insertion of rebar and/or cementitious mixture. FIG. 3B shows alternative corner block embodiment that provides a rectangular void 35 through the middle of the corner block 30 b . The corner block 30 b also includes channels 33 a and 33 b for the insertion of exterior wall panel interlocking edges 11 a , 11 b . FIGS. 3C, 3D and 3 E show side views of exemplary corner blocks 30 a , 30 b . FIG. 3F shows yet another side view of the corner block 30 a , 30 b that includes a top slot 32 a which provides the space for vertical connection of exterior panels 10 or additional corner blocks 30 a , 30 b . Steel rebar and concrete may be inserted into the top slot 32 a . FIGS. 3G and 3H show corner blocks that include top portions 32 b , 32 c which are pitched to provide the angle to abut roof panels of the complete building assembly.
[0088] The formation of the exterior walls begins with use of the corner block 30 a , 30 b . The corner block 30 a , 30 b , exterior H block 20 a , 20 b and exterior wall panels 10 are preferably designed to be approximately 8′ in height. However, the height can vary dependent on the particular construction. The exterior H block 20 a , 20 b and the corner blocks 30 a , 30 b may contain a cylindrical void 31 that is approximately 4″ in diameter that runs the entire height of the block. The cylindrical void diameter can vary. Channels 33 a , 33 b are cut into the corner block 30 a , 30 b and the exterior H block 20 a , 20 b as to directly correlate with the walls direction. The channels 33 a , 33 b measuring approximately 3″ in depth and 4″ in width are cut so as not to encroach into the cylindrical void 31 and also run perpendicular to the cylindrical void 31 through the full height of the corner block. The exterior wall panels 10 and connection blocks include the recess 14 within the top portion of the exterior wall panels 10 , where the recess 14 receives steel and/or a cementitious material for connection purposes.
[0089] A bonding adhesive may be placed on a mounting slab, not shown, where the corner block 30 a , 30 b , H block 20 a , 20 b or the exterior wall panels 10 are mounted. The corner block 30 a , 30 b may be affixed to the slab by applying the bonding adhesive between the corner block 30 a , 30 b and slab, and sliding the corner block 30 a , 30 b over an existing rebar that has been secured to the slab.
[0090] Once the corner block 30 a , 30 b is in place, an adhesive may be applied to the channel 33 a , 33 b of the corner block and applied to the interlocking edge 11 a , 11 b of the exterior wall panel 10 . The exterior wall panel 10 is placed upon the adhesive and over any existing mechanical stubouts. The exterior wall panel 10 may receive recesses to accommodate the stubouts. The interlocking edge 11 a , 11 b of the exterior wall panel 10 is inserted into the channel 33 a , 33 b of the corner block 30 a , 30 b . The sizes of the exterior wall panels 10 may be fabricated in various spans to accommodate desired specifications.
[0091] Once the exterior wall panel 10 has been interlocked and secured an H block 20 a , 20 b is added to the other interlocking edge 11 a , 11 b of the exterior wall panel 10 . The interlocking edge 11 a , 11 b of the exterior wall panel 10 receives the adhesive and the H block 20 a , 20 b is placed over or vertically slide onto the existing steel rebar that is protruding from the slab. The H block 20 a , 20 b will also contain channels 25 a , 25 b on both sides.
[0092] FIG. 4A shows an exemplary exterior wall panel 10 of indeterminent length. FIGS. 4B and 4C special spacers, 10′″ and 10 ″ of different lengths, respectively. As can be seen from FIG. 4A , the exterior wall panels 10 may be designed in various lengths in order to meet specifications and building requirements associated with the building assembly. All the exterior wall panels 10 regardless of length include the interlocking edges 11 a , 11 b that interlock with the above-described H blocks and corner blocks as a connection means.
[0093] FIG. 5A shows the interlocking of the exterior wall panels 10 with an alternative exterior H block 20 b . An adhesive material is applied to the interlocking edge 11 a and the channel 25 b as shown in FIG. 5A . The adhesive 25 bb provides a means to glue and permanently affix the exterior wall panel 10 to the alternative exterior H block 20 b . FIG. 5B shows the interconnection of a four-way block 40 with the exterior wall panel 10 . The four-way block 40 includes four channels 45 a , 45 b , 45 c and 45 d , all of which provide a means for the insertion of interlocking edges 11 a , 11 b of the exterior wall panel 10 . As discussed above in relation to the H block 20 b , adhesive is applied within the channels specifically channel 45 b as shown in FIG. 5B , and to the interlocking edge 11 a of the exterior wall panel 10 . FIG. 5C shows yet another exemplary block, specifically a three-way block 42 . The three-way block 42 includes three channels 47 a , 47 b , and 47 c . The channels of the three-way block 42 provide a female space for the insertion of male interlocking edges 11 a , 11 b of the exterior wall panel 10 . Rectangular void 41 and rectangular void 43 are provided for the four-way block 40 and three-way block 42 respectively. Rectangular voids 41 , 43 provide a space for insertion of rebar and/or concrete mixture for additional structural support of the external wall panel assembly. Rectangular voids 41 , 43 are not limited to a rectangular or square, the voids 41 , 43 may be circular or any other shape as desired.
[0094] FIGS. 6A, 6B , 6 C and 6 D show the exterior window sill/header panel detail. FIG. 6A shows the header 50 , window 55 and sill panel 52 assembled with a front view. As can be seen, header panel 50 includes interlocking edges 51 a and 51 b and sill panel 52 includes interlocking edges 53 a and 53 b . FIG. 6B shows a side view of the window sill/header panel connection. As can be seen, the header 50 includes female slots 55 a and 55 b . The sill slot 55 a provides a space for the insertion of steel rebar and/or cement and slot 55 b provides a space for the insertion of window 55 . The spaces are filled with concrete after a form is placed on the sill opening. The window is attached directly to the concrete once the form is removed. Sill panel 52 includes slot 57 for the insertion of window 55 and the completion of the sill/window/header panel. FIGS. 6C and 6D provide alternative header configurations where the top of header 50 is pitched for abutting against a roof and/or ceiling of the building assembly.
[0095] Window openings are created through the use of the header panel 50 and sill panel 52 with the use of two H blocks 20 a , 20 b . Door openings are created through the use of header panels flanked by H blocks. The header panel 50 and sill panel 52 are sized according to desired heights in order to create the desired window. The two H blocks support the header panel 50 and sill panel 52 . The header panel 50 and sill panel 52 also receives adhesive and are slidably adjustable within the H block channels 55 a , 55 b until the respective panels desired heights are attained, thus creating a window or door opening.
[0096] The above process continues until the entire perimeter of the wall is complete. Steel rebar may be added to the bond beam and fastened to any protruding rebar. Forms may also be placed around the window, door openings and headers, and a cementitious material (concrete) will fill any voids created in the wall assembly. The components of the building assembly including the exterior wall panels, interior wall panel, roof panels and corner connectors and posts are made from any suitable polymer such as polystyrene or polyurethane for high insulation, light weight concerns. The connection blocks advantageously include vertical channels that may receive rebar and/or concrete to provide further reinforcing means. The exterior surface may be coated with a substance such as polyurea or even cementious mixture in order to bond the surface and provide further rigidity and strength.
[0097] FIGS. 7A and 7B show the basic roof panel assembly according to the present invention. FIG. 7A shows the roof panel 62 which includes roof channels 63 to receive concrete and/or rebar running parallel across the panel 62 . FIG. 7B shows the roof assembly 60 , which includes roof panel 62 a , roof panel 62 b and connection insert block 67 . The roof panels 62 a , 62 b both include a roof connection slot 65 . The roof connection slot 63 travels around the perimeter of the roof panels 62 a , 62 b . A connection insert block 67 is placed within the roof connection slot 65 of the roof panel 62 so that several roof panels 62 can be joined together to form a roof assembly 60 . The channels 63 within the roof panel 62 also allow for the insertion of rebar and cementitious material. The rebar placed into the channels 63 may be fastened to the existing bond beam structure, and cementitious materials may fill the channels 63 containing the rebar.
[0098] FIGS. 8A and 8B show the end and opposite end elevations of a gable style roof that may be created with the roof peak connections 68 , 69 . A plurality of roof panels 73 , 75 are connected and joined at the roof connector 65 . Peak connection panels 68 and 69 are shown as connected at a roof peak in FIG. 8B . FIG. 9 shows a detail of a typical roof peak connection. A roof connector 65 joins peak connection panels 68 and 69 and demonstrates an exemplary roof peak as used with the gable style roof as shown in FIG. 9 .
[0099] FIG. 10 shows an arch detail 74 that may be used as an entranceway into the completed building assembly. The arch detail 74 may be constructed with the use of slotted interior panels 20 a , 20 b and the header panels 50 as described above. The arch 74 includes side slots 74 a and 74 b for connection within wall interconnecting edges 11 a and 11 b.
[0100] FIGS. 11A, 11B and 11 C show an interior wall panel constructed of polystyrene according to the present invention. Interior wall panel 80 includes connection slots 86 a and 86 b along the sides thereof with a slot 82 running horizontal across the top of the wall panel 80 . A side view of the interior wall panel 80 , as shown in FIG. 11B , gives clear view of the slot 82 and the connection slot 86 . FIG. 11C shows a connection of two interior wall panels 80 and 80 ′. As shown wall panels 80 and 80 ′ are connected with a rigid connector piece 84 which inserts into the connection slot 82 . In addition to the connection piece 84 , adhesive is used to permanently affix two interior wall panels 80 , 80 ′ as shown in FIG. 11C .
[0101] FIG. 12A shows connections associated with the interior walls 80 according to the present invention. FIG. 12A shows a perspective view exploded of interior walls 80 and 80 ′ being connected with the connector piece 84 as inserted into the connection slots 86 , 86 a of each respective interior wall. In addition to the connector piece 84 , adhesive is applied within the slots 86 and upon the connector piece 84 in order to permanently affix the interior walls 80 and 80 ′. FIG. 12A shows an exploded perspective view of connector piece 84 . The connector piece 84 may be used for insertion within the connection slots 86 of the interior walls 80 or within the connection slot 82 which runs across the top and bottom of interior walls 80 . FIG. 12B shows a top plan view of an exemplary connection of the interior walls to a corner block 92 , described in more detail in FIG. 16 . As shown in FIG. 12B , connector piece 84 inserts into the channel 86 of interior wall 80 and into the channel within the corner block on each respective side of the corner block to adjoin interior walls. As associated with the connection of two interior walls, adhesive is also used for the connection of corner blocks and interior walls. The connection of interior walls may also be accomplished through the use of H blocks and corner blocks as described above with the exterior panels. Use of H blocks and corner blocks for interior panels may provide additional reinforcement and support for the interior panel assembly. FIG. 12C shows insert block 84 mounted in wall 80 .
[0102] FIGS. 13A, 13B , 13 C and 13 D show an exemplary interior T block. FIG. 13A shows the top view of interior T block 90 that includes channels 91 a , 91 b and 91 c . As discussed above and in association with the interior corner block, the connector piece 84 is inserted between the slots of an interior T block and the slot of the interior wall 80 to provide a means for connection thereof. FIG. 13B shows a front view of the interior T block, which provides a clearer view of the connection slot 91 b . FIGS. 13C and 13D show respective side views of the interior T block 90 according to the present invention.
[0103] FIGS. 14A and 14B show an exemplary interior ceiling/header panel connection. FIG. 14A shows a front view of the connection of interior panel 80 with the header 88 attached to the top thereof. As associated with the vertical connection of interior walls, interior wall 80 is connected to the header 88 by means of a connector piece 84 inserted within the connection slot 82 of the interior wall with a complimentary slot provided in the header 88 . FIG. 14B provides a side view of the connection of interior wall 80 and header 88 .
[0104] FIGS. 15A and 15B show a front elevational view of a door entrance according to the present invention. FIG. 15A shows a door 83 surrounded by two interior wall panels 80 and 80 ′ on each side thereof of the door. A door header 85 is atop of the door with two adjacent ceiling wall panels 88 and 88 ′. As shown, ceiling wall panels are respectively connected to each interior wall 80 and 80 ′ and are pitched in order to abut to the ceiling 89 . The door header panel 85 is also pitched in order to accommodate the ceiling 89 . FIG. 15B shows a side view of the door header 85 and top door jam connection. As previously shown with the vertical connection associated with interior walls 80 , the door header 85 and top of the door jam are connected via a connection piece 84 inserted into a connection slot provided within the door header. A coating may be applied over the wall panel and door jam/header connections to bond the connection.
[0105] FIGS. 16A, 16B , and 16 C show an exemplary interior corner block 92 . FIG. 16A shows a top plan view of the interior corner block 92 which includes channels 93 a and 93 b . The channels 93 a and 93 b provide for the insertion of the connector piece 84 and for the connection of interior walls 80 to the interior corner block 92 . FIGS. 16B and 16C show the two views (front and side) associated with interior corner block 92 .
[0106] Other connection means are shown in FIGS. 17A, 17B and 17 C for the exterior walls 80 . A 45 degree connection block is shown in FIG. 17A which includes two adjoining 45 degree blocks 94 and 96 which each have connection slot associated with them, 95 a , 95 b for the 45 degree block 94 and connection 97 a , 97 b for the 45 degree block 96 . FIG. 17B shows an exemplary four-way interior block 98 which includes four channels 99 a , 99 b , 99 c , and 99 d for the insertion of connector piece 84 and to provide a connection means for interior walls 80 . FIG. 17C shows alternative interior wall 80 a which includes a female connection slot 86 and a male interlocking edge 86 ′ which adjoins with a receptive connection channel 86 of a targeted interior wall 80 a′.
[0107] Interior walls 80 may utilize the interlocking panel system as described above. Only structural walls will receive the H block 20 a , 20 b or structural corner block 92 . Once completely assembled and the utility chases and components have been placed into the building structure the structure's surface area will be encapsulated with a cementitious coating that will give the structure rigidity. Dry wall can be glued to the styrene panels without cementitious encapsulation. Also, studs could be employed to attach drywall to frame against the polystyrene. The interior could also be standard.
[0108] FIGS. 18A, 18B , 18 C, 18 D, 18 E, 18 F, and 18 G show detailed views associated with perimeter walls according to the present invention. FIG. 18A shows a front view of two H blocks 20 b being used with a perimeter panel 100 . As shown in FIG. 18A , the H blocks 20 b , 20 b ′ sit on top of a footer 180 in the ground G and are supported by the footer 180 as shown in FIGS. 18A and 18D . FIG. 18B shows a top view of the perimeter wall connection where the perimeter wall 100 is shown as being interconnected between the H blocks 20 b , 20 b ′ where the female slots 25 b and 25 a ′ receive male interlocking edges 101 a and 101 b of the perimeter wall 100 . Rebar 182 is anchored in concrete. FIG. 18D shows a detail of the H block 20 b mounted on top of cement post hole 105 . FIG. 18C shows the detail of H block footer 20 b extending into the ground into the concrete footer 105 along with the use of a rebar inserted through the rectangular void 23 of the H block 20 b . FIG. 18E shows a top view of the connection of the H block 20 b with perimeter panel 100 wherein the use of connector posts 107 is provided. The perimeter wall of FIG. 18E includes connection channels 106 a and 106 b as opposed to the interlocking edges shown in FIG. 18B . The connector posts 107 are inserted within the connection channel 106 in order to provide support for the perimeter wall 100 . FIG. 18F shows a wood beam perimeter fence 110 according to the present invention. The fence 110 includes the use of H blocks 20 b and perimeter beams 102 . The perimeter wooden beams 102 are horizontally attached to the inside of the H block posts used for the construction of the wood beam fence 110 . FIG. 18G shows a perspective side view of the perimeter beam connections with the H blocks 20 b of the present invention.
[0109] FIGS. 19A, 19B , 19 C and 19 D show some further alternative connection schemes associated with the present invention. FIG. 19A shows the use of a flat ceiling detail 72 where interior panels are shown with the use of connector 84 connected in a straight line. FIG. 19A shows a side view and shows the use as associated with a gable type roof as shown in FIG. 18C . The use of a flat ceiling 72 creates attic space storage or insulation purposes. FIG. 19B shows a barrow vault detail 76 , which includes interior walls 80 , respectively curved, and used with the connector 84 to provide the connection means for the barrow vault detail 76 . FIG. 19C shows exemplary end connection pieces 120 , 120 ′ that receive the respective ceiling panels of the flat ceiling 72 . FIG. 19D shows a top view of the header 85 used for the door header panel as was shown in FIG. 15 . The door header 85 of FIG. 19D connects to the interior panels 88 and 88 ′ by means of connector piece 84 and thus provides for the door header assembly.
[0110] FIG. 20 shows a schematic plan view of the prefabricated building assembly according to the present invention where a plurality of exterior walls 110 are connected by using H blocks 20 and corner blocks 30 . In addition to the exterior panels 110 windows are formed at header panels 50 shown along the exterior wall construction. The interior rooms are formed by partitions created by interior walls 80 and interior doors are shown with header panels 88 .
[0111] FIGS. 21A and 21B show elevation views partially completed ( FIG. 21A ) of the completed building and assembly FIG. 21B according to the present invention. FIG. 21A shows an exterior wall assembly including corner blocks 30 a at each end of the exterior wall assembly where exterior panels 110 are supported with and connected by H blocks 20 . A window W is shown with a header 50 and seal panel 52 . FIG. 21B shows the exterior wall 110 a which is covered with a cementitious material and shown in its completed form. FIG. 21B shows the plurality of roof panels that are connected through the use of plurality of roof connectors and roof panels in order to form roof assembly 60 .
[0112] The roof may be covered with standard materials on toop such as plywood, shingles or other covering. Plywood may be placed upon the roof panels and attached to the cementitious channels within the roof panels. The plywood could then be covered with standard roofing materials.
[0113] The exterior walls may have a brick exterior for aesthetics in certain locations without coating the walls. Prior to coating the exterior walls with the cementitious coating, the exterior walls may be finished with any number of standard building materials such as brick or vinyl siding which may be attached to the building assembly in lieu of the cementitious coating. The present invention disclosed a unique building assembly and method to construct low cost, thermally efficient housing in remote locations that are quick and simple to assemble. This invention is a great benefit to provide large scale housing to large numbers of people at low cost throughout the world.
[0114] Although in the preferred embodiment the panels, corners and blocks have been shown with interlocking edges used in conjunction with upper recesses that receives rebar and cementitious material, in an alternate embodiment there may be circumstances that an exterior wall panel will be joined together with flat sides of faces by an adhesive as opposed to an interlocking edge. In that situation, the wall panel corner, H-block, 45 degree block, header, sill, three-way block, four-way block, wall panel, and roof panel channel piece could under certain circumstances have flat sides and the faces of those flat sides will be joined together by an adhesive.
[0115] The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art. | The present invention relates a low cost, highly insulated light weight prefabricated building assembly capable of providing a swift, efficient and economic construction of exterior walls, interior walls and roofs to form a sturdy building assembly. The present invention includes a plurality of exterior wall panels; a plurality of styrofoam exterior connection blocks; the plurality of exterior connection blocks being capable of joining the plurality of exterior wall panels that form an exterior wall of the building; a plurality of roof panels, where the plurality of roof panels form a roof of the building; a plurality of interior wall panels; and a plurality of interior connection blocks. The plurality of interior connection blocks are used to connect the plurality of interior wall panels that form at least one interior wall of the building. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a method of manufacturing a metal bonded abrasive product, particularly one wherein the abrasive is diamond.
Metal bonded diamond products are used extensively in cutting, milling and drilling. These products consist of a mass of discrete diamond particles dispersed in a metal bonding matrix. The metal bonding matrix will typically be cobalt, tungsten, nickel or iron, alone or containing a relatively low melting alloy such as bronze.
The most commonly used methods for producing such products are the hot press method, the free sinter densification method and the infiltration method.
The hot press method involves mixing the metal powder and diamond and then cold pressing the mixture to a desired shape. The pressures used in this step are typically between 50 and 300 MPa. The shaped product is then packed into a graphite mould pack. This mould pack is placed in a hot-press machine where it is subjected to elevated temperature and pressure. The elevated temperature is typically in the range of 800 to 1100° C. and the elevated pressure is typically in the range of 10 to 50 MPa. A volume change of up to 50% is not uncommon and the final density is usually 92 to 98,5% of theoretical density.
In the free sinter densification method, the manufacture of the cold pressed product is the same as in the hot press method. Thereafter, the shaped cold pressed product is placed on a support and sintered at a temperature of around 1000° C. No pressure is applied nor is a graphite mould pack used. There is thus nothing restraining the product during sintering. A volume change of up to 50% is not uncommon and the final density is usually 92 to 98,5% theoretical density.
The infiltration method involves cold pressing the mixture as for the hot press method. Thereafter, the shaped cold pressed product can be placed on a support with no graphite mould, or a graphite mould can be used. An infiltrant such as a copper based material in strip or granule form is placed on top of the product and this is all typically heated to a temperature of 950-1150° C. This causes the infiltrant to become liquid and to be drawn into the product thus filling the remaining spaces between the powder and diamond in the cold pressed product. There is generally no volume change and the final density is usually 100% of theoretical density.
In the methods described above the final density approaches 100% theoretical density with very little porosity in the final product.
Other methods of producing metal bonded abrasive products include the use of high pressure hot isostatic pressing. This method has the effect of removing porosity from the product, but is expensive. A hot isostatic pressing is often added as a final step to the other methods described above which has the effect of removing the porosity almost completely.
Another known method is to attach a single layer of diamond particles on to the surface of a substrate by means of electroplating.
SUMMARY OF THE INVENTION
According to the present invention, a method of manufacturing a metal bonded abrasive product includes the steps of providing a mixture of a metal, in particulate form, and abrasive particles, cold pressing the mixture to the desired final shape at a pressure in the range of 320 to 1500 MPa to produce a cold pressed product, and free sintering the cold pressed product at a temperature in the range of 900 to 1300° C. under conditions which inhibit degradation of the abrasive particles and the particulate metal.
The product, thus produced, will generally contain significant porosity and a porosity exceeding that of conventional metal bonded abrasive products. The porosity will typically be in the range 10 to 25 percent by volume, although porosities of up to 30 percent are possible. It has surprisingly been found that the porous products are as effective as the traditional non-porous products. Further, the method of the invention produces such porous products more economically than the traditional non-porous products.
The invention provides further an abrasive tool such as a saw, diamond wire, drill bit or coring bit containing a metal bonded abrasive product, manufactured as described above, as an abrasive insert.
DESCRIPTION OF EMBODIMENTS
The method of the invention has application in the manufacture of a wide range of metal bonded abrasive products including saw segments, drill bit segments, beads for diamond wire and mining products such as drill or coring bits.
The metal for the matrix may be iron or an iron-rich alloy, i.e. an alloy which is predominantly iron with minor amounts of metal additives characterised by having negligible dimensional volume change as a consequence of sintering.
The abrasive particles will typically be ultra-hard abrasive particles such as diamond or cubic boron nitride.
The abrasive particle content of the metal bonded abrasive product will vary according to the nature of the product. Generally, the abrasive particle content will not exceed 30% by volume of the product, but there are some cases where this is exceeded.
The cold pressing of the powdered mixture occurs at a high pressure in the range of 320 to 1500 MPa. The preferred pressure range is 400 to 850 MPa.
The cold pressed product is then free sintered, i.e. no pressure is applied and nothing restrains the product during sintering. The sintering takes place at a temperature in the range of 900 to 1300° C. with a preferred temperature being about 1050° C. to 1150° C. The free sintering must take place under conditions which inhibit degradation of the abrasive particle and also oxidation of the metal matrix. Any degradation of the abrasive particle or oxidation of the metal matrix will tend to weaken the ultimate product produced. The conditions for the free sintering step, particularly for diamond, will generally be an inert or reducing gas such as hydrogen or nitrogen or mixtures thereof, or a vacuum.
The free sintering step will not result in any significant volume change compared with that of the cold pressed product. The porosity existing in the cold pressed product will thus still be present in the final product. The final product produced by the method of the invention may have a porosity of up to 30% by volume and typically 10 to 25% by volume. This is a porosity which will also exist in the cold pressed product.
It is also possible to infiltrate the bonded product to tailor the properties of the product to a specific end use.
The method of the invention enables metal bonded abrasive products to be produced with high product consistency and close control of dimensional accuracy and tolerance. Further, it has been found that relatively inexpensive materials such as iron and iron alloys may be used and there is no need to use graphite pieces or moulds which reduces the costs of manufacture further.
The invention is illustrated by the following non-limiting examples.
EXAMPLE 1
A coring bit was produced utilising a plurality of metal-bonded segments containing synthetic diamond as the abrasive.
The segments were produced by mixing an iron-based powder with synthetic diamond and an oil/wax binder to hold the particles together. The iron-based powder consisted of 84,5 percent iron, 11 percent cobalt, 4 percent copper and 0,5 percent carbon, all percentages being by weight.
The mixture was cold pressed at a pressure of 450 MPa to produce segments which had the net shape and size of the final segments. The cold pressed segments were then placed in a furnace at a temperature of 1120° C. with a reducing atmosphere consisting of 20 percent hydrogen and 80 percent nitrogen, both percentages being by volume. The segments were held at this temperature for 30 minutes. The resulting sintered segments had a porosity of 15 percent.
The segments were then brazed on to a coring bit in the conventional manner. A similar coring bit was produced, except that the segments used were conventional cobalt-based segments, also containing synthetic diamond, and having substantially no porosity.
The two coring bits were subjected to a drilling test on a block of reinforced concrete. The drilling speed was 1200 rev/minute, and the time to drill a hole was measured in seconds:
______________________________________Conventional segments 130.8 secondsPorous segments of the invention 154.2 seconds______________________________________
The porous segments of the invention were found to drill at a somewhat slower, but still acceptable rate. The projected life was calculated on the wear of the two segments and found to be:
______________________________________Conventional segments 44.8 metersPorous segments of the invention 45.6 meters______________________________________
Thus, the porous segments of the invention offer a longer life than conventional segments and are less expensive to produce.
EXAMPLE 2
Diamond saw blade segments were produced using the method described in Example 1 with the following changes:
The iron-based powder consisted of 75,7 percent iron, 20 percent tungsten and tungsten carbide, 4 percent nickel, 0,3 percent carbon.
The segments were assembled on a steel circular blade using laser welding.
A circular blade containing cobalt-based saw segments with substantially no porosity was compared with a circular saw using porous segments produced as described above. The tests were conducted by cutting red brick for 17 hours and measuring the wear on the segments. This wear was found to be:
______________________________________Conventional segments 0.4 mm wearPorous segments of the invention 0.3 mm wear______________________________________
Thus, the porous segments of the invention were found to wear at a slower rate when compared with conventional segments. The cutting rate through the bricks was similar in both cases.
EXAMPLE 3
Metal bonded diamond beads for use on a diamond wire were produced using an iron-based powder consisted entirely of iron. A mixture of the iron-based powder and diamond was loaded into an automatic cold pressing machine which pressed the mixture on to a solid steel ferrule at 800 MPa. This cold pressed product was placed in a furnace and exposed to a temperature of 1120° C. which was maintained for a period of 30 minutes. The reducing gas used in the furnace consisted of 10 percent hydrogen and 90 percent nitrogen, both percentages being by volume. The porosity of the sintered beads was found to be 15 percent.
The porous beads produced in this manner were threaded on to a steel wire rope and held in position on the rope by a vulcanised rubber layer. A similar diamond wire was produced using beads with substantially no porosity and produced by a method of the prior art.
A cutting test on cutting Belfast black granite was carried out using the two diamond wires. A 50 meter length of wire was used in each case. The cutting rate was measured and the number of square meters cut with each wire was measured:
______________________________________Conventional beads 4 m.sup.2 /hour cutting rate; 475 m.sup.2 cutPorous beads of the invention 3 m.sup.2 /hour cutting rate; 550 m.sup.2 cut______________________________________
The porous beads of the invention were found to cut at a slightly slower rate, but found to have a longer life.
EXAMPLE 4
A mining bit of the type used to drill holes in rock to produce a core sample for geological examination was produced. An iron-based powder consisting of 84 percent iron, 11 percent cobalt, 4 percent copper and 1 percent carbon, all percentages being by weight, was used.
A mixture of the iron-based powder and diamond was loaded into a steel die, followed by a layer of the iron-based powder without diamond, for producing a layer to bond to a steel adaptor. The steel adaptor was placed on top of the diamond-free layer and an unbonded assembly was cold pressed at a pressure of 400 MPa. This produced a cold pressed product which was placed in a furnace and exposed to a temperature of 1120° C. in an atmosphere of 10% hydrogen and 90% nitrogen for a period of 30 minutes. The diamond-bearing layer of the product had a porosity of 15 percent.
The steel adaptor was machined and threaded to enable it to be inserted into a drill string. The bit was used to drill Norite at 1500 revolutions per minute with a thrust of 1500 kg. The penetration rate achieved was 150 to 200 mm/minute and the projected life of the bit was 40 to 50 m. This compares favourably with a bit made by prior art methods and containing about 5 percent porosity. | A method of manufacturing a metal bonded abrasive product such as a saw or drill segment or bead for a diamond wire is provided. The method includes the steps of providing a mixture of the metal, in particulate form, and the abrasive particles, cold pressing the mixture to the desired final shape at a pressure in the range 320 to 1500 MPa to produce a cold pressed product at a temperature in the range 900 to 1300° C. under conditions which inhibit degradation of the abrasive particles and the particulate metal. The product, after free sintering, will generally have a relatively high porosity, for example, a porosity of 10 to 25 percent by volume. | 1 |
This application is a division of U.S. patent application Ser. No. 08/536,071, filed Sep. 29, 1995, now issued as U.S. Pat. No. 5,641,563 which is a continuation of U.S. patent application Ser. No. 08/070,270, filed Jun. 2, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Brief Description of the Invention
The invention is drawn toward absorbent, durable nonwoven articles, such as wipes, and methods for their manufacture.
2. Related Art
Synthetic wiping articles comprised of a nonwoven web made from polyvinyl alcohol (PVA) fibers and subsequently coated with covalently crosslinked PVA binder resins are known and have been sold as commercial products for many years. Chemically crosslinked PVAs provide distinct advantages in their usage in synthetic wipes. They increase and improve the elements of a dry wipe, non-linting of the wipe surface, mechanical strength, hydrophilic properties, and may also be cured in the presence of pigments to generate a colored wiping product. While their use has enjoyed considerable success, the currently known PVA binders used in synthetic wipes are chemically crosslinked in immersion baths containing potentially toxic materials, such as formaldehyde, various dialdehydes, methylolamines, and diisocyanates.
Glass and other fibers are sometimes sized (i.e., coated) with PVA coatings insolubilized with polyacrylic acid, or crosslinked with metal complexes, such as aluminum, titanium, silicon, or zirconium chelates, and the like.
U.S. Pat. No. 3,253,715 describes boil proof nonwoven filter media comprising a nonwoven fiber substrate and a binder comprising polyvinyl alcohol and polyacrylic acid. Although cellulosic fibers suitable for filters are described, there is no mention of polyvinyl alcohol fibers having utility. The polyvinyl alcohol fibers used in the present invention are prone to severe shrinkage under the pH and/or temperature conditions described in the '715 patent. In addition, the inventors herein have found that ratios of polyacrylic acid to polyvinyl alcohol in binders described in the '715 patent result in strong, but extremely rubbery, absorbent articles with poor "hand" and dry-wipe properties.
Natural chamois is a highly absorbent article derived from a goat-like antelope, and is commonly used to dry automobiles after washing. The absorbent properties of natural chamois have been emulated in several "synthetic chamois." Synthetic chamois commercially available may be formed from PVA fibers and a PVA binder crosslinked by formaldehyde, which undesirable for ecological reasons. Other synthetic chamois are known to be made from nonwoven fibers and an originally hydrophobic acrylic latex binder which has functional groups to make the binder, and thus the article, hydrophilic. These latter are inexpensive, but have very high drag property.
It would be desirous to develop a nonwoven article suitable for use in absorbing hydrophilic materials employing hydrophilic binders and fibers, without the use of formaldehyde. Such an article would allow the articles to exhibit high durability, good hand properties, low drag, and good dry-wiping properties (picks up water with no streaking) while maintaining absorption and "wet out" properties comparable to known articles. Such articles could be produced using ingredients and methods which are not as harmful to manufacturing personnel, users or the environment as are currently used ingredients. Finally, it would be advantageous if such binders could be cured in the presence of pigments to generate colored wiping products.
SUMMARY OF THE INVENTION
In accordance with the present invention, absorbent nonwoven articles are presented which can be produced using binder crosslinking agents which are less troublesome to handle, and which afford the inventive articles with as good or better absorbency and physical properties than known articles. In addition, certain preferred embodiments of the inventive articles may be made without the use of any chemical crosslinkers.
As used herein the term "absorbent" means the articles of the invention are hydrophilic (and therefore absorbent of aqueous materials).
Thus, a first aspect of the invention is an absorbent nonwoven article comprising:
(a) a nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant fiber hydroxyl groups; and
(b) a binder comprising an at least partially crosslinked and at least partially hydrolyzed polymeric resin having a plurality of pendant resin hydroxyl groups, the resin crosslinked by a crosslinking agent, the crosslinking agent selected from the group consisting of organic titanates and amorphous metal oxides, the polymeric resin derived from monomers selected from the group consisting of monomers within the general formula ##STR2## wherein: X is selected from the group consisting of Si(OR 4 OR 5 OR 6 ) and O(CO)R 7 ; and
R 1 -R 7 inclusive are independently selected from the group consisting of hydrogen and organic radicals having from 1 to about 10 carbon atoms, inclusive, and combinations thereof.
Preferably, the binder is bonded to at least a portion of the organic fibers through bonds between the pendant fiber hydroxyl groups, a bonding agent, and the pendant resin hydroxyl groups, wherein the crosslinking agent and bonding agent are independently selected from the group consisting of organic titanates and amorphous metal oxides. Also preferred articles in accordance with this aspect of the invention are those wherein the crosslinking agent and bonding agent are the same compounds, and wherein R 4 -R 7 inclusive are methyl (--CH 3 ).
Two particularly preferred articles within this aspect of the invention are those in which the organic titanate crosslinking and/or bonding agent is dihydroxybis(ammonium lactato)titanium or a titanium complex with an alpha-hydroxy acid (e.g., lactic acid) and an alditol (e.g., D-glucitol).
As used herein the terms "bond" and "bonding" are meant to include hydrogen bonds, hydrophobic interactions, hydrophilic interactions, ionic bonds, and/or covalent bonds. The term "crosslinking" means chemical (covalent or ionic) crosslinking.
Especially preferred binders useful in this and other aspects of the invention are aqueous compositions comprising copolymers of vinyl trialkoxysilane and vinyl monomers such as vinyl/acetate, at least partially hydrolyzed with alkali, and at least partially crosslinked with inorganic ions and chelating organic titanates. The inorganic ions (e.g., aluminum, zirconium) react or otherwise coordinate with silanol groups, while the titanates react with secondary hydroxyl groups on the resin. This unique dual curing approach, with possibly different crosslinking chain lengths, allows intermolecular bonding between the PVA polymers of the binder and, theoretically, between the fiber hydroxyl groups and PVA polymers of the binder.
A second aspect of the invention is drawn toward nonwoven absorbent articles similar to those of the first aspect of the invention, wherein the crosslinking agent is selected from the group consisting of dialdehydes, titanates, and amorphous metal oxides.
A third aspect of the invention is an absorbent nonwoven article comprising:
(a) a nonwoven web comprised of a plurality of organic fibers comprising polymers having a plurality of pendant hydroxyl groups; and
(b) a binder coating at least a portion of the fibers, the binder comprising polyvinyl alcohol insolubilized with an effective amount of a polymeric polycarboxylic acid (preferably polyacrylic acid).
Preferred within this aspect of the invention are those articles wherein all of the polymers making up the fibers are at least partially hydrolyzed polymerized monomers selected from the group consisting of monomers within the general formula ##STR3## with the provisos mentioned above. The nonwoven web may further include a minor portion of fibers selected from the group consisting of cotton, viscose rayon, cuprammonium rayon, polyesters, polyvinyl alcohol, and combinations thereof.
In contrast to the articles described in the above-mentioned U.S. Pat. No. 3,253,715, we have found that very low amounts of polymeric polycarboxylic acid (in the range of 1 to 5 wt. % as weight of total binder weight) afford the best wiping properties while effectively eliminating binder washout. Further, we have found that pH (negative logarithm of the hydrogen ion concentration in aqueous compositions) ranging from 3 to 3.3 specified by the above-mentioned '715 patent is suitable for the present invention, but pH values up to 4.6 may be utilized, which is much more useful for reducing web shrinkage. The articles of this aspect of the invention employ a polymeric polycarboxylic acid to insolubilize aqueous polyvinyl alcohol, thereby providing absorbent articles with superior water absorption, dry-wipe, and improved strength compared to known articles.
A fourth aspect of the invention is an absorbent nonwoven article comprising:
(a) a nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant hydroxyl groups; and
(b) a binder coated onto at least a portion of the fibers comprising syndiotactic polyvinyl alcohol, the syndiotactic polyvinyl alcohol having a syndiotacticity of at least 30%.
Articles employing the binder system mentioned in part (b) of this aspect of the invention employ syndiotactic polyvinyl alcohol (s-PVA) as a major (or only) component in the binder. The advantage of this binder is that s-PVA may be employed without a chemical crosslinking agent. This is because s-PVA tends to form microcrystalline regions. Chemical crosslinking through the use of titanates, inorganic ions, and dialdehydes may be employed, but they are rendered optional.
A fifth aspect of the invention is a method of making an absorbent nonwoven article, the method comprising:
(a) forming an open, lofty, three-dimensional nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant hydroxyl groups;
(b) entangling the fibers of the web using means for entanglement to form an entangled fiber web;
(c) coating a major portion of the fibers of the entangled fiber web with a binder precursor composition to form a first coated web having first and second major surfaces, the binder precursor composition adapted to form the binder of the second aspect of the invention; and
(d) exposing the first coated web to energy sufficient to at least partially cure the binder precursor composition to form a nonwoven bonded web of fibers.
Preferred are those methods wherein the before step (c) the entangled fiber web is calendered, and those methods wherein after step (c) the first coated web is coated on at least one of its first and second major surfaces with a second binder precursor composition. Also preferred are those methods wherein the exposing step includes drying the second binder precursor composition uniformly to form a dried and cured nonwoven web having a surface coating, and those methods wherein the dried and cured nonwoven web is calendered, thereby smoothing and fusing the surface coating.
A sixth aspect of the invention is another method of making an absorbent nonwoven article comprised of a nonwoven web of fibers, at least a portion of the fibers having a binder coated thereon, the method comprising:
(a) forming a nonwoven web comprised of a plurality of organic fibers comprising polymers having a plurality of pendant fiber hydroxyl groups, a major portion of the polymers comprising polyvinyl alcohol;
(b) entangling the fibers of the web using means for entanglement to form an entangled fiber web;
(c) coating a major portion of the fibers of the entangled fiber web with a binder precursor composition to form a first coated web having first and second major surfaces, the binder precursor composition consisting essentially of polyvinyl alcohol and an effective amount of a polymeric polycarboxylic acid; and
(d) exposing the first coated web to energy sufficient to insolubilize the polyvinyl alcohol resin to form a nonwoven bonded web of fibers.
Optionally, bonding and crosslinking agents, as discussed herein, may be added to the binder precursor composition.
Finally, a seventh aspect of the invention is another method of making an absorbent nonwoven article comprised of a nonwoven web of fibers, at least a portion of the fibers having a binder coated thereon, the method comprising:
(a) forming a nonwoven web comprised of organic fibers, the organic fibers comprised of polymers having a plurality of pendant hydroxyl groups;
(b) entangling the fibers of the web using means for entanglement to form an entangled fiber web;
(c) coating a major portion of the fibers of the entangled fiber web with a binder precursor composition to form a first coated web having first and second major surfaces, the binder precursor composition consisting essentially of syndiotactic polyvinyl alcohol having a syndiotacticity of at least 30%; and
(d) exposing the first coated web to energy sufficient to at least partially cure the binder precursor composition to form a nonwoven bonded web of fibers.
An important aspect of the invention is that articles of the invention may employ inventive binders which allow the articles to exhibit high durability, good feel, reduced drag, and good dry wiping properties while maintaining comparable water absorption and "wet out" properties to existing wipes. In addition, wiping articles of the present invention may also be cured in the presence of pigments to generate colored wiping products.
Preferred articles within the invention may also include in the binder efficacious amounts of functional additives such as, for example, fillers, reinforcements, plasticizers, grinding aids, and/or conventional lubricants (of the type typically used in wiping articles) to further adjust the absorbance, durability, and/or hand properties.
The binders useful in the articles of the invention improve on conventional formaldehyde crosslinking agents which tend to embrittle the web fibers, reducing web strength, softness, and absorption, and which present chemical hazards.
Regarding the methods of the invention, in preferred methods the "exposing" step is preferably carried out in a fashion to afford uniform drying throughout the thickness of the web. Typically and preferably the exposing step is a two stage process wherein the coated web is first dried at a low temperature and subsequently exposed to a higher temperature to cure the binder precursor. In some embodiments, a third, higher temperature curing step is employed. As discussed herein below, to achieve uniformly dried and cured articles, both major surfaces of the uncured web are preferably exposed to a heat source simultaneously, or both major surfaces are sequentially exposed to the heat source. The methods of the invention may also encompass perforating and slitting the dried and cured bonded nonwoven into various finished products.
Further aspects and advantages of the invention will become apparent from the drawing figures and description of preferred embodiments which follows.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a wipe made in accordance with the invention;
FIG. 2 is a cross-section along the lines 2--2 of the article of FIG. 1; and
FIG. 3 is a schematic diagram of a preferred method of making articles of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
1. Articles Employing Chemically Crosslinked PVA Binders
Embodiments within this aspect of the invention include articles comprising a nonwoven web of fibers having coated thereon a binder comprising polyvinyl alcohol (preferably silanol modified) crosslinked with inorganic ions, chelating organic titanates, or combinations thereof.
The nonwoven web of fibers may be made from many types of hydrophilic fibers, and may include a minor portion of hydrophobic fibers, selected from the following fiber types: cellulosic-type fibers, such as PVA (including hydrolyzed copolymers of vinyl esters, particularly hydrolyzed copolymers of vinyl acetate), cotton, viscose rayon, cuprammonium rayon and the like, and thermoplastics such as polyesters, polypropylene, polyethylene and the like. The preferred cellulosic-type fibers are rayon and polyvinyl alcohol. Webs containing 100% PVA fibers, 100% rayon fibers, and blends of PVA fibers and rayon fibers in the wt. % range of 1:100 to 100:1 are within the invention, and those webs having PVA:rayon within the weight range of 30:70 to about 70:30 are particularly preferred in this aspect of the invention, since the coated products exhibit good hydrophilicity, strength, and hand.
Some aspects of the nonwoven fiber web are common to all article embodiments of the invention. The fibers employed typically and preferably have denier ranging from about 0.5 to about 10 (about 0.06 to about 11 tex), although higher denier fibers may also be employed. Fibers having denier from about 0.5 to 3 (0.06 to about 3.33 tex) are particularly preferred. ("Denier" means weight in grams of 9000 meters of fiber, whereas "tex" means weight in grams per kilometer of fiber.) Fiber stock having a length ranging from about 0.5 to about 10 cm is preferably employed as a starting material, particularly fiber lengths ranging from about 3 to about 8 cm.
Nonwoven webs of fibers for use in the articles of the invention may be made using methods well documented in the nonwoven literature (see for example Turbak, A. "Nonwovens: An Advanced Tutorial", Tappi Press, Atlanta, Ga., (1989). The uncoated (i.e., before application of any binder) web should have a thickness in the range of about 10 to 100 mils (0.254 to 2.54 mm), preferably 30 to 70 mils (0.762 to 1.778 mm), more preferably 40 to 60 mils (1.02 to 1.524 mm). These preferred thicknesses may be achieved either by the carding/crosslapping operation or via fiber entanglement (e.g., hydroentanglement, needling, and the like). The basis weight of the uncoated web preferably ranges from about 50 g/m 2 up to about 250 g/m 2 .
Binders within this aspect of the invention preferably are crosslinked via secondary hydroxyl groups on the PVA backbone with chelating organic titanates, and optionally with dialdehydes such as glyoxal. The resultant binder system will theoretically further react with hydroxyl groups on the fibers when cured at elevated temperatures to produce coated webs with excellent wiping properties.
Particularly preferred are "dual" crosslinked binders, wherein an amorphous metal oxide coordinates with silanol groups on the PVA backbone and titanates and/or glyoxal coordinate with secondary hydroxyl groups on the PVA backbone.
Silanol modified PVA's used in the present invention may be made via the copolymerization of any one of a number of ethylenically unsaturated monomers having hydrolyzable groups with an alkoxysilane-substituted ethylenenically unsaturated monomer. Examples of the former are vinyl acetate, acetoxyethyl acrylate, acetoxyethylmethacrylate, and various propyl acrylate and methacrylate esters. Examples of alkoxysilane-substituted ethylenenically unsaturated monomers include vinyl trialkoxysilanes such as vinyl trimethoxysilane and the like.
One particularly preferred silanol-modified PVA may be produced from the copolymerization of vinyl acetate and vinyl trialkoxysilane, followed by the direct hydrolysis of the copolymer in alkaline solution (see below). One commercially available product is that known under the trade designation "R1130" (Kuraray Chemical KK, Japan). This preferred base copolymer contains from about 0.5 to about 1.0 molar % of the silyl groups as vinylsilane units, a degree of polymerization of about 1700, and degree of hydrolysis of the vinyl acetate units preferably of 99+%.
The theoretical crosslink density may range from 1 to about 40 mole % based on mole of ethyleneically unsaturated monomer. This may be achieved by addition of one or more aqueous titanates and, optionally, dialdehyde/NH 4 Cl solutions to a polyvinyl alcohol binder resin. Though dialdehydes such as glyoxal and several classes of titanium complexes have been shown to crosslink aqueous compositions of polyvinyl alcohol, we have found that chelating titanates such as dihydroxybis(ammonium lactato) titanium (available under the trade designation "Tyzor LA" from du Pont) and titanium orthoesters such as Tyzor 131 provide excellent crosslinking for wiping articles described in this invention. It is desired that crosslinking be avoided until curing conditions (i.e., high temperatures) are present. Thus, organic acids, such as citric acid, may help to stabilize titanates such as dihydroxybis(ammonium lactato) titanium in aqueous compositions until the binder precursors are exposed to crosslinking and curing conditions.
To improve the tensile and tear strength of the inventive articles, and to reduce lint on the surface of the articles, it may be desirable to entangle (such as by needletacking, hydroentanglement, and the like) the uncoated web, or calender the uncoated and/or coated and cured nonwoven articles of the invention. Hydroentanglement may be employed in cases where fibers are water insoluble. Calendering of the binder coated web at temperatures from about 5 to about 40° C. below the melting point of the fiber may reduce the likelihood of lint attaching to the surface of the inventive articles and provide a smooth surface. Embossing of a textured pattern onto the wipe may be performed simultaneously with calendering, or in a subsequent step.
In addition to the above-mentioned components of the articles of this invention, it may also be desirable to add colorants (especially pigments), softeners (such as ethers and alcohols), fragrances, fillers (such as for example silica, alumina, and titanium dioxide particles), and bactericidal agents (for example iodine, quaternary ammonium salts, and the like) to add values and functions to the wiping articles described herein.
Coating of the binder resin may be accomplished by methods known in the art, including roll coating, spray coating, immersion coating, gravure coating, or transfer coating. The binder weight as a percentage of the total wiping article may be from about 1% to about 95%, preferably from about 10% to about 60%, more preferably 20 to 40%.
2. Articles Employing PVA-PA Blends as Binders
The absorbent nonwoven articles in accordance with this aspect of the invention comprise a nonwoven web of a plurality of organic fibers comprising polymers having a plurality of pendant hydroxyl groups, a major portion of the polymers being at least partially hydrolyzed polymerized monomers selected from the group consisting of monomers within the general formula ##STR4## wherein X is O(CO)R 7 the provisos mentioned above. A binder coats at least a portion of the fibers, the binder consisting essentially of polyvinyl alcohol insolubilized with an effective amount of polyacrylic acid. Optionally, chemical crosslinking agents and/or bonding agents may also be employed.
The nonwoven web of fibers is substantially the same as that described in Section 1 above. Any fiber type, such as polyesters, polyolefins, cellulosics, acrylics, and the like, may be employed, alone or in combination. Preferably, the nonwoven web of fibers comprises one or more of the following fibers: cotton, viscose rayon, cuprammonium rayon, polyvinyl alcohols including hydrolyzed copolymers of vinyl esters, particularly hydrolyzed copolymers of vinyl acetate and the like. Preferred cellulosic-type fibers are rayon and polyvinyl alcohol. Blends of rayon and polyvinyl alcohol fibers in the weight ranges given above in Section 1 are preferred.
The fiber denier and length are also as previously described in Section 1 above, as well as the preferred ranges for uncoated web thickness and weight.
Coating of the binder resin may accomplished by the previously mentioned methods, including roll coating, spray coating, immersion coating, transfer coating, gravure coating, and the like. The binder weight as a percentage of the total nonwoven article weight for this aspect of the invention may range from about 5% to about 95%, preferably from about 10% to about 60%, more preferably 20 to 40%.
Polymeric polycarboxylic acids useful in the invention include polyacrylic acid, polymethacrylic acid, copolymers of acrylic acid, methacrylic acid or maleic acid containing more than 10% acidic monomer, provided that such copolymers or their salts are water soluble the specified pH levels; and vinyl methyl ether/maleic anhydride copolymer.
Polyacrylic acid, the most preferred polymeric polycarboxylic acid useful in the present invention preferably has a weight average molecular weight ranging from about 60,000 to about 3,000,000. More preferably, the weight average molecular weight of polyacrylic acid employed ranges from 300,000 to about 1,000,000.
Optionally, small amounts (i.e., less than about 5 wt. % of the total weight of binder) of additional monomers (such as, for example, functionalized acrylate monomers like hydroxyethylmethacrylate, vinyl azlactone monomers, and the like) may be incorporated in the PVA binder polymer to reduce binder washout during repeated use.
As with previously described embodiments, chemical crosslinkers may be used. Preferred crosslinkers are titanates, dialdehydes, borates, and the like.
The nonwoven articles of this aspect of the invention may be calendered as previously described in Section 1 to reduce lint on the surface of the article and provide a smooth surface for printing. Embossing of a textured pattern onto the wipe may be performed simultaneously with calendering, or in a subsequent step.
The above-mentioned optional components (colorants, softeners, fragrances, fillers) may also be employed in the nonwoven articles of this aspect of the invention.
3. Articles Employing Binders Comprising Syndiotactic PVA
Triad syndiotacticity, as used herein, means that of a triad of three pendant hydroxyl groups, the hydroxyl groups are positioned in an alternating pattern from side to side along the polymer chain. This is opposed to atactic, which means that the hydroxyl groups are randomly arranged, and isotactic, meaning the hydroxyl groups are positioned on the same side of the polymer chain.
Nonwoven absorbent articles within this aspect of the invention comprise a nonwoven web of fibers comprised of polymers having a plurality of pendant hydroxyl groups. The binder for articles within this aspect of the invention comprises polyvinyl alcohol having a syndiotacticity of at least 30%. Optionally, a chemical crosslinking agent may also be present.
The nonwoven web of fibers comprises fibers substantially the same as those described above as useful for the other articles of the invention. The fiber length and denier, and uncoated web thickness and weight are also as above-described in Section 1. Coating of the binder resin may be accomplished by the above-mentioned methods known in the art including roll coating, spray coating, immersion coating, transfer coating, gravure coating, and the like. The binder weight as a percentage of the total article weight for articles within this aspect of the invention may range from about 5% to about 95%, preferably from about 10% to about 60%, more preferably 20 to 40%.
For preparing syndiotactic PVA, vinyl trihaloacetoxy monomers are commonly employed, such as, vinyl trifluoroacetate, trifluoroacetoxyethyl acrylate, trifluoroacetoxyethyl methacrylate, and the like.
Polyvinyl trifluoroacetate is a preferred precursor ester for preparation of syndiotactic polyvinyl alcohol used in practice of the invention due to its high chemical reactivity making conversion to polyvinyl alcohol relatively facile. It may be hydrolyzed with alcoholic alkali, but is preferably hydrolyzed with methanolic ammonia (see Example 64 below). Polyvinyl trifluoroacetate is readily prepared by polymerization of vinyl trifluoroacetate.
Optionally, small amounts (i.e., less than about 5 wt. %) of additional monomers may be incorporated in the parent polymer to improve various properties of the polyvinyl alcohol derived therefrom. A particularly preferred syndiotactic PVA (and used in Examples 65-91 below) is hydrolyzed poly(vinyl trifluoroacetate-co-[3-allyl-2,2'-dihydroxy-4,4'-dimethoxybenzophenone]) (99.95:0.05 by weight, abbreviated as PVTFA). The triad syndiotacticity measured by 1 H NMR was 51%, isotacticity=7%, atacticity=42%.
The syndiotacticity of the polyvinyl alcohol binder employed in this aspect of the invention typically and preferably ranges from about 45% to 100% syndiotacticity. It is known that increasing syndiotacticity at constant degree of polymerization results in increased melting point for the gel. (See Matsuzawa, S. et al., "Colloid Poly. Sci. 1981", 259(12), pp. 1147-1150.) For this reason higher syndiotacticity is preferred since mechanical strength and thermal stability are improved, but aqueous compositions of polyvinyl alcohol become more viscous and/or thixotropic as syndiotacticity increases due to gel formation. For these reasons, and owing to methods of preparation, the preferred range of syndiotacticity when coated from aqueous compositions preferably ranges from about 25 to about 65% syndiotacticity.
Although detrimental to the flexibility of the nonwoven articles of the invention, it may be advantageous to incorporate a small amount (e.g., up to about 10 mole %) of a chemical crosslinker such as those mentioned above in order to eliminate washout of the binder during use. Preferred crosslinkers are the above-mentioned titanates, with dialdehydes and the like being suitable but less preferred for ecological reasons.
The nonwoven articles of this aspect of the invention may be calendered at elevated temperature as above-described to reduce lint on the surface of the article and provide a smooth surface for printing. Embossing of a textured pattern onto the wipe may be performed simultaneously with calendering, or in a subsequent step. In addition, the above-mentioned colorants, softeners, fragrances, fillers, and the like may be employed.
4. Particularly Preferred Articles and Methods
Referring now to the drawing figures, FIG. 1 illustrates a perspective view of an absorbent nonwoven article 10 made in accordance with the invention. Article 10 has a plurality of fibers 12 at least partially coated with binder.
FIG. 2 is a cross-sectional view of the article of FIG. 1 taken through the section 2--2 of FIG. 1. FIG. 2 illustrates a preferred article wherein the major surfaces 14 and 16 (illustrated in exaggerated thickness) are comprise a combination of calendered and fused organic fibers and binder. Surfaces 14 and 16 form a sandwich with nonwoven material 18.
FIG. 3 illustrates a preferred method of producing the nonwoven articles illustrated in FIGS. 1 and 2. Staple fibers are fed via a hopper 20 or other means into a carding station 22, such devices being well known and not requiring further explanation. A moving conveyer transports a carded web 26 from carding station 22, typically to a crosslapper, not shown, which forms a layered web having fibers at various angles to machine direction. Carded web 26 then typically and preferably passes through a needling station 28 to form a needled web 30 which is passed through calender station 32. At this point the calendered web 34 is not more than about 60 mils (1.524 mm) thick. Calendered web 34 then passes through an immersion bath 36 where an aqueous binder precursor composition 37 is applied. Web 34 passes under rollers 38 and emerges as a coated web 40, which then passes through a drying station 42 to form a dried web 44. Drying station 42 typically and preferably exposes the web to a temperature and for a residence time which allows substantially all of the water to be removed from the binder precursor to form a dried web 44.
Depending on the composition of the binder precursor, type of crosslinking and/or bonding agent used, amount of water present, etc., web 44 may be suitable for use without further curing. In some embodiments, it is desirable to pass dried web 44 through a final curing station 46, which is at a temperature higher than the temperature of drying station 42, to form a dried and cured web 48.
Web 48 may then be passed through another set of calender rollers 50, which may used to emboss a pattern, fuse the surfaces, and impart other qualities to the article. Web 52 generally has a thickness of no more than 60 mils (1.524 mm), and a weight ranging from about 50 g/m 2 to about 250 g/m 2 .
Web 52 may then pass through a second needling station 54 to perforate the web for decorative or other purposes, after which the web is slit and wound onto take-up roll 56.
The features of the various aspects of the invention will be better understood in reference to the following Test Methods and Examples, wherein all parts and percentages are by weight. Names of ingredients in quotation marks indicate trade designations.
Test Methods
Tensile Strength
Tensile strength measurements were made on 1×3 inch (2.54×7.62 cm) wringer damp, die cut samples using an Instron Model "TM", essentially in accordance with ASTM test method D-5035. A constant rate of extension (CRE) was employed, and jaws were clamp-type. Rate of jaw separation was 9.3 inches/min. (23.6 cm/min).
Elmendorf Tear
Elmendorf tear tests were conducted on 2.5×11 inch (6.35×27.94 cm) damp, die-cut, notched (20 mm) samples, essentially in accordance with ASTM D-1424, using an Elmendorf Tear Tester model number 60-32, from Thwing-Albert Co., with a 3200 gram pendulum. An average of four measurements was used. A high value is desired.
Absorption
Absorption measurements were made on 6×8 inch (15.24×20.32 cm) samples which were die-cut in damp conditions. The absorption measurements are reported using the following terms:
(a) Dry Weight=the dried weight of the sample, in grams.
(b) No Drip Weight=the maximum total weight of the sample and water absorbed, in grams.
(c) With Drip Weight=the total weight of the sample, in grams, after dripping for 60 seconds.
(d) Damp Weight=the weight of the sample after passing through nip rollers.
(e) Wet Out=the time it takes for a droplet of water placed on the wipe surface to be completely absorbed into the sample.
(f) % Weight (H 2 O) Loss=(No Drip Weight-With Drip Weight)/No Drip Weight.
(g) Grams Water Absorbed per Square foot (grams/929 cm 2 )=3×(No Drip Weight-Dry Weight).
(h) Grams Water Absorbed per Gram Dry Weight=(No Drip Weight-Dry Weight)/Dry Weight.
(i) MD=machine direction, CD=cross direction, "abs"=absorbed, and "eff"=effective
(j) effective water absorption=3×(no drip weight-damp weight).
Materials Description
The materials are used in the examples which follow:
"R1130" is the trade designation for a copolymer of vinyl silane and vinyl acetate containing from about 0.5 to about 1.0 molar % of the silyl groups as vinylsilane units, a degree of polymerization of about 1700, and degree of hydrolysis of the vinyl acetate units preferably of 99+% (Kuraray Chemical KK, Japan).
"Tyzor LA" is the trade designation for dihydroxybis(ammonium lactato) titanium (50 wt. % aqueous solution, available from du Pont Company, Du Pont Company), glyoxal (40 wt. % aqueous solution, Aldrich Chemicals) are then added to the silanol modified PVA solution at various proportions and combinations as described in the examples to follow.
"Tyzor 131" is the trade designation for a mixture of titanium orthoester complexes (20 wt. % aqueous solution, also available from DuPont.
"Nalco 8676" is the trade designation for a nanoscale, amorphous aluminum hydrous oxide colloid (10 wt. % aqueous solution), available from Nalco Chemical Company.
glyoxal is a dialdehyde of formula HCOCOH, available as a 40 wt. % aqueous solution from Aldrich Chemicals, Co.
"Airvol 165" is the trade designation for a 99.5+% hydrolyzed polyvinyl alcohol from Air Products and Chemicals, Inc.
EXAMPLES
General Procedure I for Preparing Inventive Articles
Nonwoven webs consisting of a blend of polyvinyl alcohol and rayon fibers (45% polyvinyl alcohol fiber having 1.5 denier and a length of 1.5 inch (3.81 cm) purchased from Kuraray, Japan, and 55% rayon fiber having 1.5 denier and a length of 1 and 9/16 inch (3.97 cm) purchased from BASF) were made using a web, making machine known under the trade designation "Rando-Webber". The resultant web had a nominal basis weight of 11.5 g/ft 2 (123.8 g/m 2 ) and an average thickness of 0.052 inch (0.132 cm).
Silanol modified polyvinyl alcohol granules ("R1130") were added to deionized water in proportions up to 10 wt. % solid in a stirred flask. The flask was then heated to 95° C. until reflux condition is achieved. The polymeric solution was then kept at reflux for a minimum of 45 minutes with adequate mixing. The solution was then cooled down to room temperature (about 25° C). The silanol modified PVA solution was then diluted to 2.5 wt. % solid. Reactants such as Nalco 8676, Tyzor LA, Tyzor 131, and glyoxal were then added to the silanol modified PVA solution at various proportions and combinations as described in the examples to follow.
A 12×15 inch (30.48×38.1 cm) piece of this nonwoven web was placed in a pan and saturated with approximately 200 g of an aqueous coating solution containing 5.00 g of total polymer.
Saturated samples were then dried and cured in a flow-through oven at various conditions to be described in the examples below. When curing was completed, the samples were conditioned for 60 minutes in 60-80° F. (140-176° C.) tap water then dried. Samples were then analyzed for hydrophilicity, water retention and absorption, tensile strength, tear strength, and dry wiping properties.
Examples 1-10 and Comparative Example A
The results of testing on Comparative Example A, a nonwoven wipe originally 59 mils (0.149 cm) thick, and known under the trade designation "Brittex-11" (available from Vileda, a division of Freudenberg Co., Germany, and which is a PVA web coated with a PVA binder crosslinked with formaldehyde) were as follows:
Wet Out=3 sec.;
% Water Loss=12.8;
Total Water Absorption=137.5 g/ft 2 (1479 g/m 2 );
g of water absorbed/g of wipe=7.9;
tensile strength (machine direction)=273 lbs/in 2 (1882 KPa);
tensile strength (cross direction)=203 lbs/in 2 (1399 KPa);
Elmendorf Tear strength (machine direction and damp)=86;
Elmendorf Tear strength (cross direction and damp)=100+.
The test results for the inventive nonwovens of Examples 1-10 are presented in Tables 1 and 2. The nonwovens of Examples 1-10 were prepared as described in General Procedure I. For each example, 200 g of the polymeric solution (2.5 wt. % of R1130) was added with the reactants described below along with 0.1 g of Orcabrite Green BN 4009 pigment. The wt. % designated below represents the wt. % of active reactant (solid) over the R1130 polymer. The coated samples were dried at 150° F. (65.5° C.) for 2 hrs. then 250° F. (121.1° C.) for 2 hrs. and finally cured at 300° F. (148.8° C.) for 10 minutes. All samples had excellent dry wiping properties, low drag, and good feel.
TABLE 1______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx.# Description (sec) Dry wipe abs/(ft.sup.2) Loss______________________________________1 Uncoated 0 11.37 148.7 24.78nonwovensubstrateCOMPARATIVE2 R1130 0 8.90 158.6 18.553 R1130/0.5 0 8.37 159.7 17.2wt. % Nalco8676/5 wt. %Tyzor 1314 R1130/0.5 wt. 0 7.46 145.7 21.2% Nalco 8676/15 wt. %Tyzor 1315 R1130/0.5 wt. 0 8.42 150.3 15.95% Nalco8676/5 wt. %Tyzor LA6 R1130/0.5 wt. 0 7.79 155.9 16.73% Nalco8676/15 wt. %Tyzor LA7 R1130/5 wt. % 0 8.26 145.5 15.71Tyzor 1318 R1130/15 wt. % 0 7.83 150.4 17.11Tyzor 1319 R1130/5 wt. % 0 8.52 151.1 16.47Tyzor LA10 R1130/15 wt. % 0 8.06 136.6 12.93Tyzor LA______________________________________
TABLE 2______________________________________ Tensile Strength (KPa) Elmendorf TearEx.# Sample Description MD CD MD CD______________________________________1 Uncoated nonwoven 1289 641 74.7 56.3substrateCOMPARATIVE2 R1120 2126 2011 85.5 93.03 R1130/0.5 wt. % 2555 2012 95.0 88.0Nalco 8676/5 wt. %Tyzor 1314 R1130/0.5 wt. % 2770 2032 86.3 100Nalco 8676/15 wt. %Tyzor 1315 R1130/0.5 wt. % 2543 2001 76.7 85.0Nalco 8676/5 wt. %Tyzor LA6 R1130/0.5 wt. % 2802 1921 90.3 100Nalco 8676/15 wt. %Tyzor LA7 R1130/5 wt. % 2481 2155 77.0 84.5Tyzor 1318 R1130/15 wt. % 2327 2201 90.8 84.0Tyzor 1319 R1130/5 wt. % 2356 1787 80.3 82.5Tyzor LA10 R1130/5 wt. % 2769 2090 78.0 87.5Tyzor LA______________________________________
Examples 11-20
The wipes of Example 11-20 were prepared as described in General Procedure I, and dried and cured as in Examples 1-10, except that the final 10 minute cure at 300° F. (121.1° C.) was eliminated. The absorbency, tensile strength and tear test results are presented in Tables 3 and 4.
It can be seen comparing the data of Tables 3 and 4 with the data of Tables 1 and 2 that addition of Tyzor LA or Tyzor 131, and the final 121.1° C. cure, gave immediate wet-out and consistently higher tensile strength and Elmendorf tear values.
TABLE 3______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx.# Description (sec) dry wipe abs/(ft.sup.2) Loss______________________________________11 R1130/0.5 wt. % 28 8.87 152.8 17.7Nalco 867612 R1130/1 wt. % 60+ 7.80 141.5 14.09Nalco 867613 R1130/1.5 wt. % 60+ 7.65 141.7 13.99Nalco 867614 R1130/2.0 wt. % 60+ 7.48 138.7 14.92Nalco 867615 R1130/0.5 wt. % 0 8.35 160.7 19.60Nalco 8676/1wt. % Tyzor LA16 R1130/0.5 wt. % 0 8.49 161.5 19.70Nalco 8676/ 5wt. % Tyzor LA17 R1130/0.5 wt. % 0 8.31 155.6 16.57Nalco 8676/10wt. % Tyzor LA18 R1130/0.5 wt. % 0 8.49 164.2 18.63Nalco 8676/1wt. % Tyzor 13119 R1130/0.5 wt. % 0 8.12 165.0 19.69Nalco 8676/5wt. % Tyzor 13120 R1130/0.5 wt. % 0 8.61 164.8 21.33Nalco 8676/10wt. % Tyzor 131______________________________________
TABLE 4______________________________________ Tensile Strength (KPa) Elmendorf TearEx.# Sample Description MD CD MD CD______________________________________11 R1130/0.5 2218 2022 91.7 85.0wt. %Nalco 867612 R1130/1 2212 1856 88.8 100.0wt. %Nalco 867613 R1130/1.5 2678 1946 83.3 90.0wt. %Nalco 867614 R1130/2.0 2961 2164 86.3 100.0wt. %Nalco 867615 R1130/0.5 2425 1783 78.3 100.0wt. % Nalco8676/1 wt. % Tyzor LA16 R1130/0.5 2182 2086 74.5 100.0wt. %Nalco 8676/5 wt. % Tyzor LA17 R1130/0.5 2379 2130 100.0 95.0wt. %Nalco 8676/10 wt. % Tyzor LA18 R1130/0.5 2390 1959 90.3 92.0wt. %Nalco 8676/1 wt. % Tyzor 13119 R1130/0.5 2295 1904 85.0 100.0Nalco 8676/5 wt. % Tyzor 13120 R1130/0.5 2419 1837 78.0 100.0wt. %Nalco 8676/10 wt. % Tyzor 131______________________________________
Examples 21-27
The inventive nonwovens of Examples 21-27 were prepared as described in General Procedure I. For each sample, 200 g of the polymeric solution (2.5 wt. % of R1130) was mixed with 1.54 g of glyoxal (40 wt. % aqueous solution) and 0.25 g of NH 4 Cl and then reacted with the reactants described below. The wt. % designated below represents the wt. % of active reactant (solid) over the R1130 polymer. The coated samples were dried at 110° F. (92.2° C.) for 4 hrs. All samples had excellent dry wiping properties, low drag, and good feel. The results of the absorbency, tensile strength, and tear strength are presented in Tables 5 and 6.
TABLE 5______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx.# Description (sec) Dry wipe abs/(ft.sup.2) Loss______________________________________21 NONE: 0 7.40 127.9 15.27COMPARATIVE22 1 wt. % 60+ 8.86 157.1 24.28Nalco 867623 3 wt. % 60+ 9.39 162.9 26.12Nalco 867624 5 wt. % 60+ 8.03 139.3 23.1ONalco 867625 1 wt. % 31 8.25 148.7 19.70A12(SO4)3(100% solid)26 3 wt. % 16 8.53 153.8 21.92A12(SO4)3(100%solid)27 5 wt. % 60+ 8.54 147.1 21.32A12(SO4)3(100%solid)______________________________________
TABLE 6______________________________________ Tensile Strength (KPa) Elmendorf TearEx.# Sample Description MD CD MD CD______________________________________21 NONE: 1717 2616 100.0 86.3COMPARATIVE22 1 wt. % 1693 2639 94.0 94.3Nalco 867623 3 wt. % 2509 1915 -- 91.0Nalco 867624 5 wt. % 2248 3230 100.0 90.3Nalco 867625 1 wt. % 1880 2202 100.0 82.7A12(SO4)3 (100% solid)26 3 wt. % 1813 2273 100.0 85.0A12(SO4)3 (100% solid)27 5 wt. % 2449 2030 100.0 96.0A12(SO4)3 (100% solid)______________________________________
Examples 28-29
Examples 28-29 demonstrated the use of nonwoven web containing 100% PVA fibers. The nonwoven web was made from 100% PVA fibers which were 1.5 denier and 1.5 inch long (3.81 cm), purchased from Kuraray, Japan, with a basis weight of 7.0 g/ft 2 (75.3 g/m 2 ) using a carding machine known under the trade designation "Rando-Webber." A 12×15 inch (30.48×38.1 cm) sample of this web was coated with a solution containing: 130 g of R1130 solution (2.5 wt. % solid), 0.16 g of Nalco 8676 (10% solid), 1.63 g of Tyzor 131 (20 wt. % in water), and 0.16 g of Orcobrite Royal blue pigment #R2008. The coated sample was dried at 150° F. (65.5° C.) for 2 hrs. then cured at 300° F. (148.9° C.) for an additional 15 minutes. The coated sample had a rubbery feel. The absorbency and tensile strength data are presented in Tables 7 and 8.
TABLE 7______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx.# Description (sec) dry wipe abs/(ft.sup.2) Loss______________________________________28 Uncoated 0 12.74 159.3 30.71100% PVAfiber webCOMPARATIVE29 Coated 100% 7 4.74 81.3 13.32PVA fiberweb______________________________________
TABLE 8______________________________________ Tensile Strength (KPa)Ex.# Sample Description MD CD______________________________________28 Uncoated 100% PVA fiber 1751 2042 web COMPARATIVE29 Coated 100% PVA fiber web 2752 2352______________________________________
Examples 30-31
Examples 30-31 demonstrated the use of a nonwoven web containing a blend of PVA and cotton fibers. The nonwoven web was made from 50 wt. % PVA fibers which were 1.5 denier and 1.5 inch (3.81 cm) in length, purchased from Kuraray, Japan, and 50 wt. % cotton fibers with a resultant basis weight of 5.5 g/ft 2 (59.2 g/m 2 ) using a web making machine known under the trade designation "Rando-Webber." A 12×15 inch (30.48×38.1 cm) sample of this web was coated with a solution containing: 110 g of R1130 solution (2.5 wt. % solid in H 2 O), 0.13 g of Nalco 8676 (10% solid in H 2 O), 1.38 g of Tyzor 131 (20% solid in H 2 O), and 0.14 g of Orcobrite Royal blue pigment #R2008. The coated sample was dried at 150° F. (65.5° C.) for 2 hours, then cured at 300° F. (148.9° C.) for an additional 15 minutes. The coated sample had excellent dry wiping properties, low drag, and good feel. The absorbency and tensile strength data are presented in Tables 9 and 10.
TABLE 9______________________________________ g H2OSample Wet out abs/g of g H2O % H2OEx.# Description (sec) Dry wipe abs/(ft) Loss______________________________________30 Uncoated 50/50 0 22.27 170.4 50.16blend ofPVA/Cotton fibersweb: COMPARATIVE31 Coated 50/50 4 5.82 57.7 17.41blend ofPVA/Cotton fibersweb______________________________________
TABLE 10______________________________________ Tensile Strength (KPa)Ex.# Sample Description MD CD______________________________________30 Uncoated 50/50 blend 384 411 of PVA/Cotton fibers web: COMPARATIVE31 Coated 50/50 blend of 3689 2919 PVA/Cotton fibers web______________________________________
Example 32
The nonwoven web used in Example 32 was made from 100% rayon fibers which were 3.0 denier and 2.5 inches (6.35 cm) long from Courtalds Chemical Company, England, using a carding/crosslap/needletacking process. Its basis weight was 16.2 g/ft 2 (174.3 g/m 2 ). A 15×15 inch sample of this web (38.1×38.1 cm) was coated with a solution containing: 250 g of R1130 solution (2.5% solid in H 2 O), 0.31 g of Nalco 8676 (10% solid in H 2 O), 3.13 g of Tyzor 131 (20 wt. % in H 2 O), and 0.4 g of Orcobrite Royal blue pigment #R2008. The coated sample was dried at 150° F. (65.5° C.) for 2 hours and then at 250° F. (121.1° C.) for 2 hours, and finally at 300° F. (148.8° C.) for an additional 10 minutes. The coated sample had excellent dry wiping properties, low drag, and soft feel.
Example 33
Example 33 demonstrated the preparation of a bactericidal wipe based on iodine and the polyvinyl alcohol/polyiodide complex. A solution of 1.2 g potassium iodide, 0.64 g iodine crystals, and 50 g of water was prepared. This solution was then saturated on a wipe prepared using the procedure of Example 5. Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue color which is a characteristic of the polyvinyl alcohol/polyiodide complex. When rinsed with water, iodine color and odor were plainly evident.
General Procedure II for Preparing Inventive Articles
Nonwoven webs consisting a blend of polyvinyl alcohol and rayon fibers (45% polyvinyl alcohol fiber having a denier of 1.5 and a length of 1.5 inch (3.81 cm) purchased from Kuraray KK, and 55% rayon fiber having a denier of 1.5 and a length of 1 and 9/16 inch (3.97 cm) purchased from BASF) were made using a web making machine known under the trade designation Rando-Webber. The resultant web had an average dry weight of 12 g/ft 2 (129 g/m 2 ) and nominal thickness of 0.056 inch (0.142 cm).
An aqueous binder precursor solution was prepared for each example containing various amounts of Airvol 165 (a 99.8% hydrolyzed polyvinyl alcohol with molecular weight 110,000 and degree of polymerization 2500, obtained from Air Products) reacted with Tyzor LA and/or Tyzor 131 and optionally, glyoxal as described in Examples 34-47 and NH 4 Cl, an acid catalyst. The binder precursor solutions also may have contained optional crosslinker(s) and pH modifiers as detailed in the Examples. A 12×15 inch (30.48×38.1 cm) piece of this nonwoven web was placed in a pan and saturated with approximately 200 g of an aqueous coating solution containing 5.00 g of total polymer.
Saturated samples were dried in a flow-through oven at 150° F. (65.5° C.), for between 30 minutes and 4 hours, and cured in a flow-through oven, preferably for greater than 10 minutes, at temperatures greater than 220° F. (104° C.). The samples were flipped every 10-30 minutes to aid in even drying conditions. When curing was completed, the samples were conditioned for 60 minutes in 60-80° F. (15.6-26.7° C.) tap water then dried. Samples were then analyzed for hydrophilicity, water retention and absorption, tensile strength, tear strength, and dry wiping properties.
Examples 34-38
Examples 34-38 illustrated the advantages of employing a titanate crosslinked PVA binder in wiping articles according to the invention. The wipes of Examples 34-38 were prepared as described in General Procedure II with the compositions described below at an initial coating weight of 5 g of polymeric material per 200 g solution and dried slowly at 150° F. (65.5° C.), followed by curing at 300° F. (148.9° C.). The absorbency, tensile strength, and tear data are presented in Tables 11 and 12, respectively.
TABLE 11______________________________________ H.sub.2 OEx. Wet Out % H.sub.2 O g H.sub.2 O Abs/Dry Eff g# Description (sec.) Loss abs./ft.sup.2 wgt. (g/g) H.sub.2 O/ft.sup.2______________________________________34 Airvol 165 0 20.49 157.62 8.20 116.22 without Titanate35 Airvol 165 0 17.52 149.55 7.95 109.86 with 5% Tyzor LA36 Airvol 165 0 13.10 142.83 7.51 101.49 with 15% Tyzor LA37 Airvol 165 0 18.89 144.96 7.77 106.56 with 5% Tyzor 13138 Airvol 165 0 15.79 133.47 7.21 96.06 with 15% Tyzor 131______________________________________
TABLE 12______________________________________ Av. Tensile Stress (KPa) Elmendorf Tear (Damp)Ex.# Description Machine Cross Machine Cross______________________________________34 Airvol 165 2489 1999 100+ 88withoutTitanate35 Airvol 165 2916 2330 100+ 89with 5%Tyzor LA36 Airvol 165 2985 2489 83 96with 15%Tyzor LA37 Airvol 165 2930 2296 86 93with 5%Tyzor 13138 Airvol 165 3103 2530 75 68with 15%Tyzor 131______________________________________
Examples 39-45
Examples 39-45 illustrated the advantages of employing a titanate, and optionally, glyoxal crosslinked PVA binder in wiping articles according to the invention. The wipes of Examples 39-45 were prepared at an initial coating weight of 5 g total PVA, 1.59 g glyoxal, and 0.25 g NH 4 Cl per 200 g solution and dried slowly at 150° F. (65.5°). The absorbency, tensile strength, and tear data are presented in Tables 13 and 14, respectively.
TABLE 13______________________________________ H.sub.2 OEx. Sample Wet Out % H.sub.2 O g H.sub.2 O Abs/Dry Eff g# Description (sec.) Loss abs./ft.sup.2 wgt. (g/g) H.sub.2 O/ft.sup.2______________________________________39 Airvol 165 1 14.47 125.37 7.42 88.11 with Glyoxal, NH4Cl, w/out Titanate40 Airvol 165 1 14.91 124.62 7.39 87.81 with Glyoxal, NH4Cl, and 1% Tyzor LA41 Airvol 165 1 14.65 128.88 7.34 92.64 with Glyoxal, NH4Cl, and 50% Tyzor LA42 Airvol 165 1 14.75 130.53 7.35 93.33 with Glyoxal, NH4Cl, and 10% Tyzor LA43 Airvol 165 1 to 25 13.83 121.05 7.34 84.36 with Glyoxal, NH4Cl, and 1% Tyzor 13144 Airvol 165 1 to 20 15.27 128.61 7.48 91.23 with Glyoxal, NH4Cl, and 5% Tyzor 13145 Airvol 165 1 14.58 121.92 7.27 83.97 with Glyoxal, NH4Cl, and 10% Tyzor 131______________________________________
TABLE 14______________________________________ Avg. Tensile Elmendorf Tear PVA Stress (KPa) (Damp)Ex.# Description Retention Machine Cross Machine Cross______________________________________39 Airvol 165 80.5 2482 2255 98 100+withGlyoxal,NH4Cl, w/outTitanate40 Airvol 165 83 2709 2193 86 100withGlyoxal,NH4Cl, and1% Tyzor LA41 Airvol 165 91.2 2592 2055 86 96withGlyoxal,NH4Cl, and5% Tyzor LA42 Airvol 165 91.9 2758 2034 88 95withGlyoxal,NH4Cl, and10% Tyzor LA43 Airvol 165 78.2 2696 2455 97 100+with GlyoxalNH4Cl, and1% Tyzor 13144 Airvol 165 86.1 2772 2392 94 100+withGlyoxal,NH4Cl, and5% Tyzor 13145 Airvol 165 75.1 2558 2310 100+ 100+withGlyoxal,NH4Cl, and10% Tyzor131______________________________________
Example 46
Example 46 demonstrated the ability to color the wiping articles of this invention made in accordance with General Procedure II in varying colors and shades. A binder precursor solution was prepared consisting of 100 g 5 wt. % Airvol 165, 1.68 g Tyzor LA, 0.03 g, 0.06 g, 0.13 g, 0.25 g, or 0.5 g pigment dispersion, and deionized water to achieve a total solution weight of 200 g for each run. The binder precursor solution was coated onto a 12×15 inch (30.48 cm×38.1 cm) piece of PVA/rayon nonwoven produced as described in General Procedure II, dried at 120° F. (48.9° C.) for 2 hours, and finally cured for one hour at 140° F. (57.0° C.). Upon completion of run, the samples were conditioned for 60 minutes in 60-80° F. (140-176° C.) water and dried. Results are shown below.
______________________________________Pigment, Amount Results______________________________________"Orcobrite Red BN", Good color and fastness.0.03 to 0.5 g"Orcobrite Yellow Good color and fastness.2GN", 0.03 to 0.5 g"Orcobrite Green BN", Good color and fastness.0.03 to 0.5 g"Aqualor Green" Good color, binder washout."Aqualor Blue" Good color, binder washout.______________________________________
The aqueous pigment dispersions known under the trade designation "Aqualor" were obtained from Penn Color (Doylestown, Pa.), while those known under the trade designation Orcobrite aqueous pigment dispersions were obtained from Organic Dyestuffs (Concord, N.C.). Good results were obtained with a wide variety of the "Orcobrite" series of pigments. A major difference between the "Aqualor" and "Orcobrite" pigment dispersions, as supplied, was the substantially higher alkalinity of "Aqualor" pigment dispersions, perhaps leading to insufficient cure by the titanate crosslinking agent. Generally speaking it was found that the best results with regard to coloring were obtained at cure temperatures of 240-250° F. (115.6-121° C.), although higher temperatures were also useful.
Example 47
Example 47 demonstrated the ability to impregnate the synthetic wipes of the invention made in accordance with General Procedure II with a number of antibacterial, antifungal, and disinfecting solutions for use in the health care, business, and/or food service trades. A nonwoven produced in accordance with General Procedure II was saturated with an aqueous solution containing 1.2 g potassium iodide, 0.64 g solid iodine crystals, and 50 g deionized water.
Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue, characteristic of the polyvinyl alcohol/polyiodide complex. When the article was rinsed with water, the iodine color and odor were plainly evident.
General Procedure III for Preparing Inventive Articles
A 12 by 15 inch (30.48×38.1 cm) piece of polyvinyl alcohol/rayon (45% polyvinyl alcohol fiber having a denier of 1.5 and a length of 1.5 inch (3.81 cm) purchased from Kuraray KK, and 55% rayon fiber having a denier of 1.5 and a length of 19/16 inch purchased from BASF) blended nonwoven fiber substrate (thickness=56 mil (0.142 cm), basis weight=11.5 g/ft 2 (123.8 g/m 2 ), prepared using a web marking of Rando-Webber) was placed in a pan and saturated with 200 g of an aqueous binder precursor solution containing 5.00 g total polyvinyl alcohol and polyacrylic acid, prepared by mixing a 5% aqueous solution of "Airvol 165" with a 2.5% aqueous solution of the polyacrylic acid. "Airvol 165" (a 99.8% hydrolyzed polyvinyl alcohol, MW=110,000, DP=2500 obtained from Air Products) was used in combination with polyacrylic acid (750,000 MW, Aldrich Chemical Co.). The binder precursor solution pH was adjusted with 85% phosphoric acid. The sample and tray were placed in a flow through drying oven at 120-150° F. (48.9-65.5° C.) for 2 hours followed by curing at 300° F. (148.9° C.) as specified in Table 15. The samples were flipped over after about 30 minutes and 60 minutes to aid in maintaining even drying. When curing was completed the samples were conditioned for 60 minutes in 60-80° F. water then dried.
Examples 48-62
Example wipes 48-62 were made in accordance with General Procedure III at the conditions specified in Table 15, and subsequently analyzed for wet out, absorptivity, tensile strength, tear strength, and dry wiping properties. The test results are presented in Tables 16-17. Examples 48-62 each contained 0.1 g "Orcobrite Yellow 2GN 9000" (a yellow pigment, available from Organic Dyestuffs, Corp.).
TABLE 15______________________________________ % Coating Conditioned Loss During Coat Wt.Ex.# Description Cure Conditions Conditioning (g/m.sup.2)______________________________________48 Polyacrylic 2 HR 120° F. 4 40.5Acid, pH = 3.0, (48.9° C.)/COMPARATIVE 5 MIN 300° F. (148.9° C.)49 Airvol 165 2 HR 120° F. 1 48.4(polyvinyl (48.9° C.)/alcohol), 5 MIN 300° F.pH = 3.0, (148.9° C.)COMPARATIVE50 1 part 2 HR 120° F. 0 49.5Polyacrylic (48.9° C.)/acid/ 5 MIN 300° F.2 parts Airvol (148.9° C.)165, pH = 3.051 1 part 2 HR 120° F. 0 48.2Polyacrylic (48.9° C.)/acid/ 5 MIN 300° F.3 parts Airvol (148.9° C.)165, pH = 3.052 1 part 2 HR 120° F. 0 56.9Polyacrylic (48. 9° C.)/acid/ 5 MIN 300° F.5 parts Airvol (148.9° C.)165, pH = 3.053 1 part 2 HR 120° F. 0 58.5Polyacrylic (48.9° C.)/acid/ 5 MIN 300° F.10 parts Airvol (148.9° C.)165, pH = 3.054 1 part 2 HR 150° F. 0 52.4Polyacrylic (65.6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.555 1 part 2 HR 150° F. 0 51.6Polyacrylic (65.6° C.)/acid/ 15 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.556 1 part 2 HR 150° F. 0 55.4Polyacrylic (65.6° C.)/acid/ 25 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.557 0.1 part 2 HR 150° F. 1 49.5Polyacrylic (65.6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.558 0.5 part 2 HR 150° F. 1 53.5Polyacrylic (65. 6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.559 1 part 2 HR 150° F. 0 55.4Polyacrylic (65.6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.560 1 part 2 HR 150° F. 0 49.7Polyacrylic (65.6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 4.061 1 part 2 HR 150° F. 0 52.3Polyacrylic (65.6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 4.662 1 part 2 HR 150° F. 1 48.3Polyacrylic (65.6° C.)/acid/ 5 MIN 300° F.99 parts Airvol (148.9° C.)165, pH = 3.3______________________________________
TABLE 16______________________________________Tensile TensileStrength Strength Elmendorf ElmendorfMachine Cross Web Tear Test Tear TestEx. Direction Direction (Machine (Cross Web % H.sub.2 O# (KPa) (KPa) Direction) Direction) Loss______________________________________48 1910 1014 65 73 1149 3054 2240 53 90 1150 2937 2420 54 100+ 1051 3296 2117 74 86 1152 2379 1751 87 100+ 1153 2779 1813 81 82 1354 2772 2737 96 100+ 1855 2958 2565 77 100+ 2056 2854 2399 79 90 2157 2758 2365 91 100+ 1658 2523 2324 88 100+ 1859 2723 2461 85 100+ 2060 2737 2392 89 100+ 2261 2785 2358 87 100+ 2262 2909 2275 90 100+ 19______________________________________
TABLE 17______________________________________Ex. Total H.sub.2 O Abs. H.sub.2 O Abs./Dry Eff. H.sub.2 O Abs.# (g/ft.sup.2) Wt. (g/g) (g/ft.sup.2)______________________________________48 175.7 9.70 105.249 137.7 7.70 98.950 142.7 7.63 101.151 139.4 7.27 94.552 126.2 6.13 84.953 136.3 6.67 96.354 158.7 7.78 114.055 157.0 8.03 111.456 156.0 7.46 111.157 148.6 7.41 105.058 159.7 7.86 115.359 160.9 6.31 116.760 158.7 8.55 116.161 162.1 8.21 118.362 150.8 7.76 108.7______________________________________
Example 63
This example demonstrated the preparation of a bactericidal wipe based on iodine and a polyvinyl alcohol/polyiodide complex, and made in accordance with General Procedure III. A solution of 1.2 g potassium iodide, 0.64 g iodine crystals, and 50 g water was prepared. This solution was coated onto a sample of 1:2 polyacrylic acid/polyvinyl alcohol wipe prepared as in General Procedure III above. Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue characteristic of the polyvinyl alcohol/polyiodide complex. When rinsed with water iodine color and odor were plainly evident.
General Procedure IV for Preparing Inventive Articles
A 12 by 15 inch (30.48×38.1 cm) piece of polyvinyl alcohol/rayon (45% polyvinyl alcohol fiber having a denier of 1.5 and a length of 1.5 in (3.81 cm) purchased from Kuraray KK, and 55% rayon fiber having a denier of 1.5 and a length of 1.56 inch (3.96 cm) purchased from BASF) blended nonwoven fiber substrate (thickness=56 mil (0.142 cm), basis weight 11.5 g/ft 2 (123.8 g/cm 2 ), prepared using a web making machine known under the trade designation "Rando-Webber") was placed in a pan and saturated with 200 g of an aqueous binder precursor solution containing 5.00 g total polyvinyl alcohol. "Airvol 165" (a 99.8% hydrolyzed polyvinyl alcohol, MW=110,000, DP=2500 obtained from Air Products) was used in combination with syndiotactic polyvinyl alcohol prepared in Example 64 to comprise the polyvinyl alcohol content in Examples 65-91. The binder precursor solutions may also have contained optional crosslinker(s), and pH modifiers depending on the Example. The sample and tray were placed in a flow through drying oven at 120-50° F. (48.9-65.6° C.) for 3 to 4 hours as specified. The samples were flipped over after about 30 minutes and 60 minutes to aid in maintaining even drying. When curing was completed the samples were conditioned for 60 minutes in 60-80° F. (15.6-26.7° C.) water then dried. Samples were then analyzed for wet out, absorptivity, tensile strength, tear strength, and dry wiping properties, with the results reported in Tables 18-27.
Example 64
Preparation of Syndiotactic PVA
This example illustrated the preparation of syndiotactic polyvinyl alcohol employed in Examples 65-91.
The polyvinyl trifluoroacetate (PVTFA) copolymer described above (300 g) was dissolved in 700 g acetone. This solution was slowly added to 1700 g of 10% methanolic ammonia that had been cooled in ice to 15° C. Despite vigorous mechanical stirring a large ball of solid material formed on the stirrer blade making stirring ineffective. After addition was complete the ball of material was broken up by hand and the mixture was shaken vigorously. The process was repeated twice more (elapsed time was about 3 hr). The divided mass was vigorously mechanically stirred for 20 minutes and allowed to stand at room temperature overnight.
The supernatant liquid was decanted off leaving a mixture of white powder and yellow fibrils. The solids were collected by filtration and spread in a tray at 15.6° C. to evaporate residual solvent. The solids were collected when constant weight over 2 hr was achieved. The solid was chopped in a blender to give 87.3 g of beige powder, 92% yield, referred to hereinafter as "Syn". Analysis of this material was carried out using IR and 1 H NMR spectroscopy, and Gel Permeation Chromatography. The results indicated the likely presence of traces of trifluoroacetate esters and salts. The triad syndiotacticity measured by 1 H NMR in DMSO-d 6 was 33%, atacticity=50%, isotacticity=17%, The difference between the hydrolyzed polymer and the trifluoroacetate precursor polymer may be due to acid catalyzed epimerization of hydroxyl groups during drying or solution in boiling water.
Examples 65-70
Examples 65-70 illustrated the advantages of employing syndiotactic polyvinyl alcohol alone or in blends with atactic polyvinyl alcohol in wiping articles according to the invention. The articles were prepared at an initial coating weight of 5 g total PVA/200 g solution. Curing conditions were 4 hr at 48.9° C.
TABLE 18______________________________________ Tensile Tensile % Coating Strength Strength Weight Elmendorf Machine Cross Loss Tear Direct- Direct- During Machine ElmendorfEx. Descrip- ion ion Condition- Direc- Tear Cross# tion (KPa) (KPa) ing tion Direc-tion______________________________________65 100% 2061 1131 10.1 63(5) 95(7) AIRVOL 16566 99% 2186 1496 8.9 79(2) 100+ AIRVOL 165:1% Syn67 95% 2027 1427 8.4 74(7) 89(0) AIRVOL 165:5% Syn68 90% 2475 1799 7.8 75(4) 86(7) AIRVOL 165:10% Syn69 80% 2109 1510 6.2 100+ 95(4) AIRVOL 165:20% Syn70 100% Syn 2661 1979 5.5 100+ 91(0)______________________________________
TABLE 19______________________________________ Total Water Water Absorption/ Effective Wet % Absorp- Dry wt. WaterEx. Descrip- Out Water tion of Sample Absorption# tion (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)______________________________________65 100% 0 17.4 134.52 7.92 99.60 AIRVOL 16566 99% 0 20.0 150.09 8.38 112.50 AIRVOL 165:1% Syn67 95% 0 15.0 136.17 7.81 99.90 AIRVOL 165:5% Syn68 90% 0 14.8 130.50 7.63 95.40 AIRVOL 165:10% Syn69 80% 0 15.8 131.58 7.14 94.80 AIRVOL 165:20% Syn70 100% 2 16.8 143.25 7.33 106.71 Syn______________________________________
Examples 71-83
These examples demonstrated the use of syndiotactic polyvinyl alcohol with chemical crosslinkers (Tyzor LA and/or glyoxal) in wiping articles according to the invention. Curing conditions were 3.5 hr at 150° F. (65.5° C.). Mole % crosslinking amounts for Tyzor LA were based on four bonds between titanium and polyvinyl alcohol. Mole % crosslinking amounts for glyoxal were based on four bonds between glyoxal and polyvinyl alcohol.
TABLE 20______________________________________ Total Water Effective % Water Absorption/ Water Wet Wa- Absorp- Dry wt. Absorp-Ex. Out ter tion of Sample tion# Description (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)______________________________________71 1% Blend of Syn 0 25.1 129.2 8.65 119.49 in Airvol 165 with 20 mol % Tyzor LA crosslinking72 1% Blend of Syn 0 20.1 137.4 8.12 117.36 in Airvol 165 with 20 mol % Tyzor LA crosslinking73 5% Blend of Syn 0 16.9 134.7 7.71 106.92 in Airvol 165 with 20 mol % Tyzor LA crosslinking74 5% Blend of syn 0 17.8 135.2 7.62 108.00 in Airvol 165 with 20 mol % Tyzor LA crosslinking75 10% Blend of 0 21.7 128.4 7.96 110.29 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking______________________________________
TABLE 21______________________________________ Total Water Effective % Water Absorption/ Water Wet Wa- Absorp- Dry wt. Absorp-Ex. Out ter tion of Sample tion# Description (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)______________________________________76 10% Blend of 0 18.2 133.8 7.70 108.2 Syn in Airvol 165 with 20 mol % Tyzor LA crosslinking77 1% Blend of 0 15.6 137.8 8.42 107.7 Syn in Airvol 165 with 40 mol % Glyoxal crosslinking78 1% Blend of 0 17 139.4 8.58 111.4 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking79 5% Blend of 0 15.8 145.4 8.35 114.7 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking80 5% Blend of 0 17.3 139.7 8.80 113.3 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking81 10% Blend of 0 11.2 144.5 8.40 107.1 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking82 10% Blend of 0 16.9 154.8 8.30 122.3 Syndiotactic in Airvol 165 with 40 mol % Glyoxal crosslinking83 10% Blend of 0 13.1 141.9 7.46 105.2 Syndiotactic in Airvol 165______________________________________
TABLE 22______________________________________ Tensile Strength % Coating Machine Tensile Weight Loss Direction Strength Cross DuringEx.# Description (KPa) Direction (KPa) Conditioning______________________________________71 1% Blend of 2158 2082 4.3Syn inAirvol 165with 20 mol %Tyzor LAcrosslinking72 1% Blend of 2971 1724 4.2Syn inAirvol 165with 20 mol %Tyzor LAcrosslinking73 5% Blend of 2572 2199 4.4Syn inAirvol 165with 20 mol5 Tyzor LAcrosslinking74 5% Blend of 2737 1979 4.5Syn inAirvol 165with 20 mol %Tyzor LAcrosslinking______________________________________
TABLE 23______________________________________ Tensile Tensile Strength Strength % Coating Machine Cross Weight Direction Direction Loss DuringEx.# Description (KPa) (KPa) Conditioning______________________________________75 10% Blend of 2475 1944 5.1Syn in Airvol165 with 20mol % Tyzor LRcrosslinking76 10% Blend of 2910 2240 4.8syn in Airvol165 with 20mol % Tyzor LRcrosslinking77 1% Blend of 2820 1889 3.3syn in Airvol165 with 40mol % Glyoxalcrosslinking78 1% Blend of 2351 -- 3.5Syndiotacticin Airvol 165with 40 mol %Glyoxalcrosslinking79 5% Blend of 2482 2006 3.2Syndiotacticin Airvol 165with 40 mol %Glyoxalcrosslinking80 5% Blend of 2199 1841 3.5Syndiotacticin Airvol 165with 40 mol %Glyoxalcrosslinking81 10% Blend of 2227 1696 3.5Syndiotacticin Airvol 165with 40 mol %Glyoxalcrosslinking82 10% Blend of 2379 1786 3.0Syndiotacticin Airvol 165with 40 mol %glyoxalcrosslinking83 10% Blend of 2365 1696 1.8Syndiotacticin Airvol 165______________________________________
Examples 84-86
Examples 84-86 demonstrated the effect of coat weight on wiping parameters of articles made in accordance with General Procedure IV. A binder precursor solution consisting only of 30% syndiotactic PVA was coated onto nonwoven substrates at various coating weights (i.e., 1 g, 2 g, 5 g total PVA in coating solution) as indicated in Tables 24 and 25, which also present the absorbency and strength test results.
TABLE 24__________________________________________________________________________ Tensile Tensile % Weight Elmendorf Strength Strength Loss Elmendorf Tear Machine Cross During Tear CrossEx. Direction Direction Condition- Machine Direct-# Description (KPa) (KPa) ing Direction ion__________________________________________________________________________84 5 g:100% Syn 2661 ± 117 1979 ± 69 5.5 100+ 91 ± 085 2 g:100% 2006 ± 131 1351 ± 34 3.3 75 ± 6 96 ± 2 Syn86 1 g:100% 1441 ± 138 1186 ± 89 2.9 84 ± 9 100+ syn__________________________________________________________________________
TABLE 25______________________________________ Total Water Effective % Water Absorption/ Water Wet Wa- Absorp- Dry wt. Absorp-Ex. Out ter tion of Sample tion# Description (sec) Loss (g/ft.sup.2) (g/g) (g/ft.sup.2)______________________________________84 5 g:100% 2 16.8 143.25 7.33 106.71 Syn85 2 g:100% 0 18.2 146.31 8.31 116.40 Syn86 1 g:100% 0 20.5 157.68 10.43 127.62 Syn______________________________________
Examples 87-89
Examples 87-89 demonstrated the results of direct ammonolysis of polyvinyl trifluoroacetate after the binder precursor solutions was coated on the nonwoven substrate. The absorbency and strength of these articles (Tables 26 and 27) were superior to those of 30% syndiotactic polyvinyl alcohol coated from water described in the preceding examples. One explanation of the benefits observed is that acid catalyzed loss of syndiotacticity was minimized by use of this method which probably provided greater surface area for ammonolysis.
TABLE 26______________________________________ Tensile Tensile Strength strength Machine Cross % Weight Loss Direction Direction DuringEx.# Description (KPa) (KPa) Conditioning______________________________________87 16 g 3744 3041 0 PVTFA/ammonolyzed (5 g PVA)88 6.5 g 2544 2082 0 PVTFA/ammonolyzed (2 g PVA)89 3.2 g 1551 1165 0 PVTFA/ammonolyzed (1 g PVA)______________________________________
TABLE 27______________________________________ Water Effective % Total Absorp- Water Wet Wa- Water Ab- tion/ Absorp-Ex. Out ter sorption Dry wt of tion# Description (sec) Loss (g/ft.sup.2) Sample (g/g) (g/ft.sup.2)______________________________________87 16 g PVTFA/ 0 22.5 114.4 5.86 81.5 ammonolyzed (5 g PVA)88 6.5 g PVTFA/ 0 23.0 143.2 7.90 107.6 ammonolyzed (2 g PVA)89 3.2 g PVTFA/ 0 30.1 166.2 9.82 134.1 ammonolyzed (1 g PVA)______________________________________
Example 90
This example demonstrated the preparation of a bactericidal wipe based on iodine and the polyvinyl alcohol/polyiodide complex utilizing General Procedure IV. A solution of 1.2 g potassium iodide, 0.64 g iodine crystals, and 50 g water was prepared. This solution was coated onto a sample of a wipe as prepared in Examples 84-86. Initially, a brown color was observed where the sample had been treated. The brown color gradually changed to blue characteristic of the polyvinyl alcohol/polyiodide complex. When rinsed with water iodine color and odor were plainly evident.
Example 91
A sample containing 5 g 30% syndiotactic PVA as the only binder component in 200 g total solution was prepared and coated as in Examples 84-86 containing 0.1 g "Orcobrite Blue 2GN" pigment (Organic Dyestuffs Corp., Concord, N.C.). The sample was cured at 250° F. (121° C.) for 2 hours. The sample discolored slightly and had a strong odor, but was colorfast after conditioning in luke-warm water for 2 hours.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope of the invention, and it should be understood that this invention is not to be unduly limited to the illustrated embodiments set forth herein. | Nonwoven articles having high durability and absorbent characteristics, and their methods of manufacture, are presented. One preferred article is characterized by
(a) a nonwoven web comprised of organic fibers comprised of polymers having a plurality of pendant hydroxyl groups; and
(b) a binder comprising an at least partially crosslinked and at least partially hydrolyzed polymeric resin having a plurality of pendant resin hydroxyl groups, the resin crosslinked by a crosslinking agent, the crosslinking agent selected from the group consisting of organic titanates and amorphous metal oxides, the polymeric resin derived from monomers selected from the group consisting of monomers within the general formula ##STR1## wherein: X is selected from the group consisting of Si(OR 4 OR 5 OR 6 ) and O(CO)R 7 ; and
R 1 -R 7 inclusive are independently selected from the group consisting of hydrogen and organic radicals having from 1 to about 10 carbon atoms, inclusive, and combinations thereof. | 3 |
TECHNICAL FIELD
This invention relates generally to the wheel, and more particularly concerns the wheel, pulley, and gear, which can alter shape from traditional circular to oval, elliptical, tractor like, and multitudes of other shapes, and return to its original traditional circular shape, all this when stationary or while moving in rotational motion.
BACKGROUND ART
The wheel is an ancient device dating back from 3500 to 3000 B.C. and has been used for many purposes such as carts, potters wheel, spinning wheel, water wheel, windmill, pulley, gears, the vehicular wheel on bicycles, motorcycles, cars, trains, trailers, and other vehicles of all types. There are many types of wheels, large, small, thick, thin, round, square, rectangular, elliptical, and oval. The most used wheel configuration is circular, but other shapes are in use.
One of the primary limitations of the conventional wheel is that it is designed for the efficient use for travel on a particular surface at a specific speed range where upon moving onto another type of surface, speed, smoothness of riding across, and the efficiency of the common wheel drops considerably or, on many occasions it will be of no use whatsoever. For example: the wheel of a racing car is designed for high speed, with minimal road contact on straight runs, but enough contact for having adequate friction to make controlled high speed turns on curves. The road surface on which the race car rides is generally relatively smooth and hard, such as asphalt and concrete. As the race car is driven onto a differing surface, such as a soft dirt road or rocky country road, the very efficient wheel of the race car suddenly becomes a burden, very inefficient, even unstable, unless exchange to off-road wheels are made to adapt to the new surface conditions. Similarly, the wheels of an off-road vehicle are excellent for an off-road environment such as a soft, sandy, or gravely surface. Driving onto a hard, smooth, road surface however, the off-road wheels become a liability, preventing high road speed and providing a bumpy ride.
Unique improvements have been sought and found, some with excellent features. U.S. Pat. No. 3,459,454 discloses an elliptical wheel having excellent shape characteristics for riding over a soft media surface. U.S. Pat. No. 3,620,278 is another example of a distinguished wheel featuring some configuration variability to broaden the wheel footprint on the ground surface to increase traction. There remains, however, a need for other wheels possessing the flexibility to provide superb riding conditions even as terrain conditions vary severely. This invention overcomes this handicap eloquently. As terrain conditions change, adjust the wheel to one of multiple available shapes applicable for maximum efficiency and smooth riding for each distinctive surface condition.
Other purposes of the wheel in form of pulley and gears is to transmit rotational power from one shaft to another, from one gear to another, from one pulley to another, or to transmit rotational power through use of belts, chains, or similar power transmission extensions.
DISCLOSURE OF THE INVENTION
It is the object of the present invention to provide wheels for vehicular travel where the wheels shape can be changed to provide small area or large area surface contact for control of traction and contact pressure between the wheels and the surface traveled upon. This is maximized by having the flexibility to change the shape of the wheel at any time, when stationary or in motion, from common circular to elliptical, oval, tractor like, a multitude of shapes, as terrain conditions impose. The numerable possible shapes of the wheel are composed through extension and retraction of radial ram rods extending from the wheel center hub placing pressure onto the moderately flexible constant length wheel rim and shaping the rim to the desired wheel configuration. As the wheel is stationary, each ram rod extends or retracts to its required length and then stays constant at that specific length. After the wheel is set into motion, it requires a continuous length adjustment of each ram rod to keep the shape of the wheel constant. This continuous ram rod length adjustment is required for all shapes when the wheel is in motion, except for the common circular shape of the wheel. The conversion of conventional circular shaped wheel into a multitude of other wheel shapes by extension and retraction of radial ram rods is managed and directed by a computer processor, where the exact location information of one or more ram rods respective to wheel, vehicle, ground surface is referenced and communicated to the processor, which consequently determines each ram rod length for its specific location on the wheel in agreement with the selected wheel configuration. Simultaneously, the computer processor combines instant wheel speed information with each ram rod location information and pending on the wheel shape selected, determines and directs each ram rod to extend at a specific rate, stay constant in length, or retract at a specific rate to keep the perfect selected wheel shape of the rim.
It is another object of the present invention to provide wheels for vehicular travel where through the change in shape of the wheels from conventional circular to horizontal oval the vehicle can be lowered, or to vertical oval the vehicle can be raised, respective to the traveled on surface.
A further object of the present invention is that innumerable shapes of the wheel can be composed as long as there is harmony between the constant length rim and spoke length.
It is also the objective of the present invention, where the wheel, whether it is smooth like a pulley, with gear-like teeth or other wheel rim surface, through change in its shape from conventional circular to elongated oval, elliptical or other arched elongated configuration, will engage at its elongated side another wheel, pulley or gear, for rotational power transmission, without moving the power transmitting rotating shaft. This simple power engagement with transmission of rotational power is applicable to any rotating shaft of gear train machinery like lathes, mills, including cars using no clutch or complex automatic transmission. Disengagement is accomplished when returning the wheel, pulley or gear to the common circular shape.
Another purpose of the present invention is that upon contact between long straight sides of two oval or tractor like shaped wheels, gear like wheels or pulleys, more power can be transmitted between them than with conventional power trains since a much larger area of power transmission contact can be achieved through geometrically shaped wheel configurations other than the conventional circular.
It is yet another objective of the present invention to lower or heighten the top and bottom of a gear sprocket or pulley of chain or belt drive system to keep the belt or chain at a certain height out of harms way, so not to interfere with other items, all this without any change in gear/wheel ratio.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the view of the variable shaped wheel in conventional circular configuration of the present invention.
FIG. 2 shows one of the multitudes of configurations of the variable shaped wheel, namely that of the horizontal oval shape.
FIG. 3 shows another variation of shapes of the variable shaped wheel, resembling a tractor like configuration.
FIG. 4 depicts the change of the variable shaped wheel of normal circular convention into that of an elongated vertical oval and elongated horizontal oval configuration.
FIG. 5 is the side elevation view of two non-engaged variable shaped wheels or pulleys and the same wheels after one changed in configuration to higher vertical profile for power transmission contact.
FIG. 6 is the side view of FIG. 5 showing two non-engaged variable shaped wheels with one rotating drive shaft and non-rotating second wheel shaft and the same wheels after one changed configuration for contact engagement, resulting in both shafts rotation.
FIG. 7 are two contact engaged horizontally long oval variable shaped wheels.
FIG. 8 is a conventional circular configured variable shaped wheel pulley belt/chain system.
FIG. 9 is the variation from FIG. 7 by changing shape of one variable shaped wheel/pulley to a vertically long oval configuration.
FIG. 10 is the variation from FIG. 7 by changing shape of one variable shaped wheel to a horizontally long oval configuration.
FIG. 11 shows the wheel in its square or rectangular configuration.
FIG. 12 shows the wheel in its oval configuration.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-3 show several configurations of the embodiment of variable shaped wheel of the present invention. Although the embodiments shown in FIGS. 1-3 have relative defined shapes, it should be understood that the embodiment of the variable shaped wheel may have numerable other shapes pending on the combination of extended lengths of ram rods. FIGS. 4-10 show other application of the present invention.
Referring to the drawing in particular, the invention embodied therein in FIG. 1 comprises of wheel 10 which is constructed with selection to change to other configurations in accordance with the invention. Shown in conventional circular shape, wheel 10 includes a rotational power transmission member 18 with hub 12 secured to it, from which in a radial fashion, a multitude of variable length extending and retracting ram rods 20-31 move within guides 32, mounted on or as part of a continuance to hub 12. Instead of single acting ram rods, multiple part extension ram rods can be used for longer range application. Extension of ram rods 20-31 is accomplished through hydraulic, electrical, mechanical, pneumatic mean or combinations thereof. The extend of extension, retraction, non-movement for each ram rod 20-31 is determined, controlled and directed by computer as elaborated on in more specific terms later. Although twelve ram rods 20-31 are shown in FIG. 1, fewer or more may be used depending on specific applications and wheel size. Ram rods 20-31 are connected to the constant length rim 34 by pin 16. Other non-rigid connection can be used. In the embodiment shown, rim 34 is traditional, circularly shaped as consequence of having ram rods 20-31 of same length extended from guides 32. As will be shown later, ram rods 20-31 when extended, retracted or not moved laterally, individually or in groups, will cause, if in harmony with rim 34, wheel 10 to change in shape. The exception to this is well known, the common circular wheel 10 where all ram rods 20-31 are of the same constant length. For rim 34 to change shape but at the same time be able to withstand loads on wheel 10, it must consist of material which is strong, flexible but rigid enough between ram rods 20-31 to support heavy loads. Change in shape of rim 34 must be limited to the materials elastic deformation limits, outside the plastic deformation range. Mounted onto rim 34 is compliant tire 14. As tire 14 contacts the ground 36, a footprint 38 for the circular shaped wheel 10 is established. The footprint 38 for a circular shaped wheel 10 is relatively small and has therefore limited application for travel on soft and rocky surfaces and other application explained later.
In the particular embodiment of FIG. 2, the circular wheel 10 of FIG. 1 has been reconfigured to horizontal oval shaped wheel 42. This change of shape is being accomplished by extension in length of ram rods 23 and 29 to the longest, ram rods 24 and 28 slightly shorter, ram rods 25 and 27 shorter again, with shortest ram rod 26 at the bottom center of horizontal oval shape wheel 42. The upper half of the oval configured wheel 42 is a reflection in uniformity of the bottom half of the oval configured wheel 42. As the power transmission member 18 rotates counter clockwise thus rotating all of oval wheel 42, all ram rods adjust continually in length to keep the horizontal oval shape of wheel 42. For example: as oval wheel 42 is in couter clockwise rotating motion 39, ram rod 29, one of the longest, is moving towards the position of ram rod 28, and is then becoming ram rod 28. During this transition phase, ram rod 29 is gradually retracted into guide 32 until reaching the extended length of ram rod 28. The rate or speed of retraction of ram rod 29 from the position shown in FIG. 2 and moving until it becomes ram rod 28 is determined and directed through computerized means 47, based on the oval configured wheel 42 velocity. This is being accomplished as follows: A sensory system determines the location of one or more ram rods with respect to wheel 42, ground 36 and the motion is it in, forward shown as counter clockwise on FIG. 2, backward or not moving at all. This information is transmitted through input 46 to computer means 47. Program 48 with input information of wheel 42 oval configuration and components thereof, performs in conjunction with computer means 47, calculations using complied data input 46 and other information such as wheel 42 velocity, relative vehicle speed, ground speed, soil conditions and other relevant data, to determine the required rate of retraction, required rate of extension, or no movement, and length of each ram rod for each minute incremental rotational unit. This direction giving information output 49 is then transmitted to each ram rod 20-31, responding to the directive with corresponding retraction, extension, or no movement. Program 48 containing information for each wheel configuration and also for transformation phase from one wheel shape to another may be selected by manual means such as selection by a driver of a vehicle or by automatic means such as input from condition of road traveled which then the most efficient wheel shape is determined and selected. So, oval configured wheel 42 rotates counter clockwise 39, ram rod 28 is moving towards the position of ram rod 27. During this transition, ram rod 28 is gradually retracted until reaching extended length of ram rod 27 is gradually retracting in length until reaching extended length of ram rod 26. During the same rotational movement of wheel 42 ram rod 26 is moving towards the position of ram rod 25. During this transition, ram rod 26 is gradually extending in length until reaching extended length of ram rod 25. All other ram rods adjust in a similar manner as described beforehand. As long as oval wheeled configuration is rotating, all ram rods simultaneously and continually adjust by extending or retracting lengths in a fashion so that the ram rod ends follow the oval shape of rim 34. It should be understood from the previous discussion, that the extending, retracting ram rods form the oval shape of the rim 34. The rim does not determine shape as on a conventional wheel but conforms to the shaping of the ram rods 20-31. Due to the specific horizontal oval shape on wheel 42, the ground surface contact 40 is many fold in area compared with conventional circular configured wheel 10 ground surface contact 38 of FIG. 1. Large ground contact area becomes important when the wheel of a vehicle is on soft and spongy soil such as sand or mud. The defeat of the German Army in Russia during World War II can be partially attributed to the high unit load by German vehicles on the soft and muddy Russian roads, getting stuck, where as the Russians vehicles, especially Russian tanks with low per square foot loading on the soil succeeded in overcoming such handicapped. The present invention will provide the advantage of distributing the loading on the soil so that soft and muddy soil can be traveled over without getting stuck, which would normally not be passable by vehicles with conventional wheels. In addition, the larger contact area between wheel and the ground provides the great advantage of added friction when trying to climb a snow and ice covered hill during the winter time. Another feature of wheel 42 is that through change in shape to horizontal oval, the axle on a vehicle will be lowered, lowering the vehicle, making access into and out of it much easier. This is especially an attractive feature on vehicles serving small children, older adults and the handicapped people.
FIG. 3 shows another embodiment of the present invention which is another variation in configuration in form of a tractor shaped wheel 50, providing even larger ground surface contact 52. This particular wheel shape is especially adaptable to construction and farm machinery such as backhoes, farm tractors, trailers and the like, preventing them from getting stuck in the soft farm field or muddy construction site. It is also an advantage when used on tractor like vehicles where low load distribution onto the ground surface is essential but with the added advantage to drive on common highways without damage to them and conforming to the commonly high speed traffic. It should also be understood that numerous other shaped wheel configurations are possible including elliptical, square and rectangular but round edged, non-uniform, with limitations only imposed upon by the range of length of extension and retraction of ram rods 20-31 and harmonious conformation of wheel rim 34. In FIG. 4, the conventionally round shaped wheel 10 is reconfigured to an elongated vertically oval shaped wheel 60 and elongated horizontally oval shaped wheel 66. Reconfiguration 60 provides the advantage of axle elevation 62 and thus raises any vehicle upon which the axle is mounted. This provides more clearance with the ground surface which is very useful when fording streams, crossing muddy roads, driving through deep snow, without getting wet or getting trapped. Reconfiguration 66 provides the advantage of axle height decrease 64 of any vehicle upon which the axle is mounted. This provides easier access onto a vehicle which is especially helpful to handicapped and older people. It also lowers a vehicle to pass under a low overpass.
FIGS. 5 & 6 (a front view of FIG. 5) show a further embodiment of the invention. Round shaped wheel pulley 70 is rotated counterclockwise by drive 72. Conventionally circular-shaped wheel pulley 74 is in no-contact 78 with rotating wheel pulley 70 and is therefore stationary. As the normally round shaped wheel pulley 74 is reforming to vertical oval shape wheel pulley 76, contact is made between round shaped wheel pulley 70 and vertical oval shaped wheel pulley 76 at point 79. Rotational power of pulley 70 is transmitted at point of contact 79, providing clockwise rotational power to shaft 80. Upon changing vertical oval shaped wheel pulley 76 back to its original conventionally circular shaped wheel pulley 74, disengagement of rotational motion of shaft 80 occurs. As can be shown, upon change in shape of circular to oval and back to circular, a simple transmission of power from one drive to another results.
This is also accomplished by change of the common circular pulley form to elliptical and any other form differing from the common circular. The wheel pulley can also be of other patterns such as gears and the like. This simple power transmission can be used for application on vehicles of all types, industrial power machinery, tools, any machinery requiring engagement and disengagement of rotational power.
FIG. 7 shows the large area of contact 86 for power transmission between two wheels where the large contact area provides large rotational power transfer from one to another. Normal contact for power transfer between conventional circular wheels, pulleys, gears are very small in area, thus limiting power transmission from one drive to another. This handicap is overcome by exacting large surface contact areas, providing large power transmission without failure.
FIGS. 8, 9, 10 show belt or chain driven wheels, gear sprockets or pulleys where the change in configuration provides spacial advantages. FIG. 8 shows a conventional power transfer from one wheel to another. FIG. 9 shows a change of shape of one wheel to vertical oval with the result of having the power transmission belt raised at a higher slope, providing extra space in between the belts. This can be of great advantage to bring the belts outside an area where it would interfere without change in power transmission ratio. In FIG. 9 the belts show upper and lower sections where they are spread apart to provide extra space in-between, the belts upper and lower portion shown in FIG. 10 were put closer together by change in one wheel shape to horizontal oval, again without changing the power transmission ratio. The low profile in FIG. 10 will be especially advantageous on machinery where space is at a premium.
A new variable shaped wheel and application thereof have been described and shown. The alteration in configuration of a vehicular wheel when variable traveling surface conditions are encountered is of utmost importance and most of us have experienced getting trapped on a muddy, sandy, silty street, on a snowy hill or on a flooded plane and hoping to have the means on the vehicle to elude entrapment. The present invention provides the mode to do so and more, by being able to change shape of the variable wheel when moving or when stationary. Another most important feature of many others is the ease and simplicity at which through change in shape of the variable wheel, gear or pulley to oval, elliptical, or any other non-circular shape, power can be transmitted from one powered shaft to another un-powered shaft and then disengage by changing back to the conventional circular shape. The simplicity and flexibility of the present invention, the variable shaped wheel, to alter configuration to a variety of shapes and then return to its original shape, provides a flexibility to apply the most efficient, convenient, form for application encountered in industry and by the public on a daily basis, will save time and energy for vehicular travel, on power transmission systems, and other applications involving the conventional circular wheel, gear, or pulley.
While specific embodiments of the invention have been shown and delineated in detail to illustrate the application of the creative principles, it should be understood that various changes, modifications, and substitutions may be incorporated in the embodiments without departing from such principles. | A variable shaped wheel having a hub, a plurality of extendable ram rods connecting the hub and shape adaptable rim. Extension and retraction of the ram rods cause the rim to harmonize to a selected wheel shape such as horizontal oval, vertical oval, elliptical, tractor like and numerous other shapes, when stationary and while moving. The selected shape of the variable wheel in motion is maintained by continual length adjustment of the ram rods. The variable shaped wheel adjusts to the most effective, efficient shape for travel over varying surfaces such as asphalt, concrete, sand, mud, rock, snow, ice and others, providing optimum speed and comfort. It is another purpose of the present invention, through change in shape of the variable wheel, pulley, gear from conventional circular to oval, elliptical, and shapes other than circular, to make contact at the periphery along the elongated axis with another wheel, pulley, gear, providing for simple and effective rotational energy transmission from one wheel, pulley, gear, to another. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application Ser. No. 61/274,202, filed on Aug. 13, 2009. The contents of the previously mentioned provisional application is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to a building insulation sheathing system that provides for efficient installation of insulation, material and labor reduction during installation, as well as provides a stable structure for ease in attachment of protective and/or decorative cladding to a building. The present invention further includes a method for insulating a building using the sheathing system of the present invention.
BACKGROUND OF THE INVENTION
[0003] The insulation of buildings, whether residential or commercial, is an incredibly important part of the structure and when installed properly, ensures energy and financial efficiency for the life of the building. Unfortunately, insulation systems in the market today have a number of shortfalls including, but not limited to, energy inefficiency, complicated installation processes, increased dew point within exterior walls thereby supporting the growth of mold, noncontiguous insulation thereby providing outlets for heat and cooling loss, and design deficiencies that inhibit incorporation into existing structures.
[0004] There are a number of insulation systems that are commonly used in building. For example, insulation systems such as fiberglass insulation, spray foam, structurally insulated panels (“SIPs”) and ICF are common insulation systems used in the building industry. Unfortunately, there are many disadvantages in using such systems. The following paragraphs discuss a few of the insulation systems commonly used in the building industry and outlines a few of their disadvantages.
[0005] Fiberglass insulation is commonly used in most homes built today, due to its low costs & easy application. Fiberglass insulation generally includes a fluffy fiberglass material adhered to a moisture barrier backing A common fiberglass insulation is the insulation produced and sold by Owens-Corning® that is predominantly identified by its pink color. Unfortunately, fiberglass insulation has some disadvantages including the following:
It performs way below its marketed R-Values. Has problems with mold and mildew. It does not stop any thermo-bridging. (wood members) It only works for some applications. (rims) Requires a vapor barrier. Requires a weather barrier. Its cavity filled insulation. Does not control the convection looping process. The dew point is in your stud cavity. The stud space can not be used for mechanical without affecting the performance of the wall.
[0016] Another common insulation system used in building today is spray foam. Spray foam insulation is normally a polyurethane foam pumped into the home to insulate walls (e.g. between the studs), ceilings and everywhere else one would expect insulation. As a result, it helps to keep the heat inside during the cold months and the hot air outside when it's warm. Although originally the work of professionals only, do-it-yourself spray foam insulation kits are available. Spray foam has the benefit of installation ease in that it can be sprayed onto almost any existing structure as long as there is sufficient structure to hold it in position. However, spray foam has a number of disadvantages including the following:
The cost is about 3.5 times higher than fiberglass. It does not control thermo-bridging. (wood members) Requires a weather barrier. Its cavity filled insulation. The dew point is in your stud cavity. The stud space can not be used for mechanical without affecting the performance of the wall.
[0023] Still another insulation system are structurally insulated panels (“SIPs”). SIPs are high performance building panels used in floors, walls, and roofs for residential and light commercial buildings. The panels are typically made by sandwiching a core of rigid foam plastic insulation between two structural skins of oriented strand board (OSB). Other skin material can be used for specific purposes. SIPs are manufactured under factory controlled conditions and can be custom designed for each home. SIPs also have a number of disadvantages including the following:
It is a panelized wall system. (non-conventional build) Costs are high. Has solid wood members around all seams. (thermo-bridging) The seams are caulked to reduce air flow. (maintenance)
[0028] Finally, insulating concrete forms (“ICF's”) have become an insulation system that is being used in construction of commercial and residential buildings. ICFs are hollow “blocks” or “panels” made of expanded polystyrene insulation (EPS) or other insulating foam that construction crews stack to form the shape of the walls of a building. The workers then fill the center with reinforced concrete to create the structure. There are over 20 brands of ICFs in North America, each providing variations in design and materials. ICFs have a number of disadvantages including the following:
Costs are high. It is not yet considered a conventional build. Mold problems.
[0032] The construction industry and home improvement product manufacturers still have found difficulties in remedying the problems identified above in a single system. The industry still searches for an insulation system that is easily installable, reduces waste materials, is reasonably priced, reduces the problems of water penetration and mold and provides a simple and stable structure for securing a protective and aesthetically pleasing exterior cladding.
SUMMARY OF THE INVENTION
[0033] Embodiments of the present invention relate to a building insulation sheathing system that provides for efficient installation of insulation, material and labor reduction during installation, as well as provides a stable structure for ease in attachment of protective and/or decorative cladding to a building. The present invention further includes a method for insulating a building using the sheathing system of the present invention.
[0034] The building insulation sheathing system generally includes one or more insulation panel(s) comprising one or more insulating materials. Each panel includes an exterior surface and an interior surface. The sheathing system further includes one or more batten(s) that are adjoined to the exterior surface of the panel(s) with one or securing fastener(s). The sheathing system also includes one or more securing fasteners used to secure the panels to the frame of a building, such as the studs, plywood or foundation walls and for securing the batten(s) to the panel(s). In various embodiments of the present invention, the panels include foam boards, the battens are made from wood and the fasteners, are screws, nails, rivets or adhesives.
[0035] The present invention also includes a method of insulating and cladding a building with a building insulation sheathing system. This method comprises providing a building that has an exposed and prepared frame for receiving an insulation system and cladding to the exterior of the frame. Next, one or more panel(s) are positioned on the exterior surface of the frame of the building (e.g. the exterior surfaces of the studs or plywood panels.) Once the panel(s) are positioned, one or more battens are positioned on the exterior surface of the panel(s). Next, the panel(s) are secured to the frame and the batten(s) to the panel(s) with one or more fasteners. Once secured, trimming excess portions of the panels to square corners and open portal apertures is performed. Finally, cladding may be attached to the sheathing system of the present invention by attachment of the cladding to the batten(s) or by applying the cladding to the entire exterior surface of the sheathing system. Additionally, an installer may seal any seams formed between the panels with a sealing material, such as insulation foam, caulk, tapes or adhesives.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 depicts a front view of one embodiment of an insulation panel that includes securing battens;
[0037] FIG. 2 depicts a top view of one embodiment of an insulation panel including securing battens and beveled edges;
[0038] FIG. 3 depicts a back view of one embodiment of an insulation panel that includes securing battens positioned on the horizontal and vertical seams;
[0039] FIG. 4 depicts a cross section side view of one embodiment of an insulation panel with battens;
[0040] FIG. 5 depicts a front view of one embodiment of an insulation panel that does not disclose securing battens, but illustrates the batten placement grooves;
[0041] FIG. 6 depicts a top view of one embodiment of an insulation panel without battens, but illustrates the grooves provided for batten placement;
[0042] FIG. 7 depicts a back view of one embodiment of an insulation panel without battens, but illustrates the sloped areas positioned on the horizontal and vertical seams;
[0043] FIG. 8 depicts a cross section view of one embodiment of an insulation panel without battens;
[0044] FIG. 9 depicts a cross section top view of one embodiment of a building insulation sheathing system of the present invention that is installed, but before cuts;
[0045] FIG. 10 depicts a cross section top view of one embodiment of a building insulation sheathing system of the present invention that is installed and the ends have been cut back flush;
[0046] FIG. 11 depicts a cross section top view of one embodiment of a building insulation sheathing system of the present invention that is configured for a wall and ceiling application;
[0047] FIG. 12 depicts perspective views of one embodiment of two insulation panels of the present invention wherein one panel is shown from the front perspective view and the other is shown from the back perspective view;
[0048] FIG. 13 depicts a perspective exploded view of one embodiment the building insulation sheathing system, wherein window and exterior door installation process is illustrated;
[0049] FIG. 14 depicts a cross section view of one embodiment of a building insulation sheathing system of the present invention wherein the wall section detail shows insulation panels properly applied to the foundation walls, rim area, wall area and ceiling;
[0050] FIGS. 15 and 16 depicts a cross section view of one embodiment of a building insulation sheathing system of the present invention wherein this figure illustrates the different layers of a home with the insulation sheathing system installed on both the walls and the ceiling;
[0051] FIG. 17 depicts a perspective view of one embodiment of vertical and horizontal seam, which includes the slope on the product and the positioning of the seam on the stud, and further illustrates the groves for the battens to be placed in when the next sheet is applied;
[0052] FIG. 18 is a front perspective view of one embodiment of the building insulation sheathing system of the present invention, wherein the panels are adjoined with battens that are attached to the framing using a fastening device;
[0053] FIG. 19 is a back perspective view of one embodiment of the building insulation sheathing system of the present invention, wherein the panels are adjoined with battens that are attached to the framing using a fastening device;
[0054] FIG. 20 is a back perspective view of one embodiment of the building insulation sheathing system of the present invention, wherein spray foam is applied in the seams to connect each panel; and
[0055] FIG. 21 is a front perspective view of one embodiment of the building insulation sheathing system of the present invention and the use of the system with the other components of the building, such as framing and cladding.
DETAILED DESCRIPTION OF THE INVENTION
[0056] The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the present invention.
[0057] FIGS. 1-21 depict various embodiments of the building insulation sheathing system of the present invention. In general the insulation sheathing system 10 of the present invention includes one or more insulation panels 12 , one or more securing battens 14 , and one or more fastening devices 16 to secure the panels 12 and battens 14 to the outer surface of the frame and/or studs of a building structure.
[0058] The insulation panels used in the sheathing system of the present invention are normally made from an insulating material and are shaped so that they are easily adjoined to the frame and/or studs of a building and can be attached so as to provide substantially complete coverage of the exterior of walls, floors, ceiling and roof of a building. In various embodiments foam boards may be used for insulation panels in the sheathing systems of the present invention. Foam boards are rigid panels of insulation that can be used to insulate almost any part of a building, from the roof down to the foundation walls. Foam boards provide good thermal resistance and often add structural strength to the building. Furthermore, foam board insulation sheathing reduces heat conduction through structural elements, like wood and steel studs.
[0059] The most common types of materials used in making panels, such as foam board, include polystyrene, polyisocyanurate or polyiso, and polyurethane. However, other suitable insulation materials for may be used in producing the panels of the present invention.
[0060] In various embodiment of the present invention, molded expanded polystyrene (MEPS) may be used to form the panels. MEPS is a closed-cell material that can be molded into many everyday items, such as coffee cups and shipping materials, or into large sheets of foam board insulation. MEPS foam board insulation is commonly known as beadboard. To make beadboard, loose, unexpanded polystyrene beads containing liquid pentane are mixed with a blowing agent and poured into an enclosed container. The mixture is heated to expand the beads many times their original size. The beads are then injected into a mold. Under more heat and pressure, they expand to become foam blocks, which are shaped as needed.
[0061] The physical properties of MEPS foam board vary with the type of bead used. It's manufactured at various densities, depending on the application. Beadboard for roofing materials generally is dense enough to walk on without damage; wall insulation foam boards are normally several times less dense than roof boards. R-values range from 3.8 to 4.4 per inch (2.54 cm) of thickness.
[0062] In other embodiments of the present invention, the panels may be formed using an extruded expanded polystyrene (XEPS) foam insulation. XEPS is similar to MEPS, but has a number of differences. To make XEPS, the polystyrene pellets are mixed with various chemicals to liquefy them. A blowing agent is then injected into the mixture, forming gas bubbles. The foaming, thick liquid is then forced through a shaping die. When cooled, the panel is cut as required. Foam densities are typically 1.5 pounds per cubic foot (24 kilograms per cubic meter).
[0063] XEPS is normally more expensive than MEPS. However, like MEPS, the R-value depends upon the density of the material and is generally about R-5 per inch. XEPS is also much more consistent in density and has a higher compressive strength than MEPS, making it better suited for use on roofs or for wall panels. Extruded polystyrene also has excellent resistance to moisture absorption.
[0064] Polyisocyanurate or polyiso and polyurethane are very similar, closed-cell foam insulation materials that may be used to produce the panels of the present invention. Because both materials generally offer high R-values (R 5.6 to R 8) per inch of thickness, an installer can use a thinner foam board to achieve the required thermal resistance. This can be an advantage if you have space limitations.
[0065] Polyiso foam board insulation is available in a variety of compressive strengths. Compressive strength refers to the ability of a rigid foam board to resist deformation and maintain its shape when subjected to a force or load. Also, polyiso remains stable over a wide temperature range (−100° F. to +250° F.). This makes it particularly good as roofing insulation. And when used with a laminated aluminum foil facing, polyiso foam board provides an effective moisture or vapor barrier.
[0066] The panels of the present invention may be of any shape and size that is beneficial to provide substantially complete coverage of walls or ceiling that are to be insulated. In various embodiments of the present invention, the panels may have the following dimensions: Height— 1 ′ to 24′, Length—2′ to 24′; and Width 1″ to 24″. In other embodiments the dimensions may be Height—2′ to 12′, Length—3′ to 16′; and Width 2″ to 18″. In yet other embodiments the dimensions of the panels may be Height—3′ to 6′, Length—4′ to 12′; and Width 4″ to 12″. The shape may be any shape that can provide best wall or ceiling coverage, such as rectangular or square.
[0067] The building insulation sheathing system of the present invention also includes one or more battens. A batten is a thin strip of solid material, typically made from wood, plastic or metal. Battens are used in building construction and various other fields, as both structural and purely cosmetic elements. In the steel industry, battens may also be referred to as “top hats”, in reference to the profile of the metal. Any type of wood, plastic or metal may be used to produce the battens of the present invention. For example, wood materials may include pine, cedar, ash, oak, or any other type of suitable wood material; plastics may include, polyethylene, polypropylene, polycarbonate or any other type of suitable plastic; and metals may include, steel, aluminum or any other type of suitable metal.
[0068] The battens of the present invention may be of any shape and size that is beneficial to provide substantially complete coverage of walls or ceiling that are to be insulated. In various embodiments of the present invention, the battens may have the following dimensions: Height—1″ to 12″, Length—2′ to 24′; and Width ⅛″ to 2″. In other embodiments the dimensions may be Height—2″ to 8″, Length—3′ to 18′; and Width ¼″ to 1 ½″. In yet other embodiments the dimensions of the panels may be Height—3″ to 6″, Length—4′ to 12′; and Width ⅜″ to ¾″. The shape may be any shape that can provide best wall or ceiling coverage, such as rectangular or square.
[0069] Battens are used in the sheathing system of the present invention in various ways. For example, the battens used in embodiments of the present invention are generally provided to provide a platform for securing the panels to the frame and/or studs of the building. However, the battens may also be used to secure and/or adjoin adjacent panels. Furthermore, the battens function may be used to allow for the attachment of protective and decorative cladding to the battens thereby covering the sheathing system and interior frame of the building.
[0070] The building insulation sheathing system of the present invention also includes one or more fasteners for adjoining the battens to the panels and the adjoined battens/panels to the frame and/or studs of the building. Fasteners that may be used with various embodiments of the present invention include screws, nails, rivets, adhesives (e.g. glues, sealants, tapes . . . ) or any other type of securing device. In various embodiments of the present invention screws provide a good means to secure the battens and panels to the frame and/or studs of the building. Screws are generally easy to administer and provide a good mechanical connection between the battens, panels and frame/studs. Screws also allow for the components (e.g. panels, battens, screws) of the sheathing system to be easily removed and reclaimed.
[0071] The following discussion addresses the Figures, which illustrate various embodiments of the components and sheathing system of the present invention. FIGS. 1-4 depict one embodiment of the sheathing system of the present invention that includes a panel 12 having a substantially rectangular configuration, a plurality of battens 14 that are positioned horizontally and vertically on the exterior surface 18 of the panel 12 to provide a platform for securing the panel 12 . The battens may be placed directly on the exterior surface of the panel 12 as illustrated in FIG. 1 or may be recessed by placement of the battens 14 in grooves 20 that are positioned in the panel 12 as illustrated in the top view of FIG. 2 .
[0072] The panel 12 of this embodiment is a rectangular sheet that includes one or more beveled edges 20 as illustrated in FIGS. 1-3 . In various embodiments of the present invention, the beveled edges 22 are oriented to intersect and nest under or over the beveled edges 22 of an adjacent panel 12 . In yet other embodiments, the upper and lower beveled edges 22 are oriented so as the seam 23 between the edges 22 slant down and outward. Such a configuration assists in the movement of moisture away from the frame of the building.
[0073] In cold weather, warm inside air containing water vapor can get past the wall finish and insulation, condensing inside the colder wall cavity. In hot, humid climates the same thing can happen, just in the reverse direction. Humid outdoor air in the summer can condense inside cool, air conditioned wall cavities. If enough of this happens and the water cannot escape, wood rot, mold, and other moisture-related problems can occur. The sheathing system of the present invention assists in preventing the problems associated with moisture as found in other insulation systems. First the sheathing system of the present invention is positioned exterior to the frame/studs of the building. Such a positioning does not allow for the trapping of moisture between the cavities of the studs and thereby avoids the problems associated with moisture within the frame or studs. Next the orientation of the beveled edges allows for moisture to move away from the frame/studs of the building, thereby avoiding a buildup of moisture within the walls of the building.
[0074] FIGS. 5-8 depict another embodiment of the building insulation system of the present invention that is illustrated with grooves for receiving battens. In this embodiment grooves 20 are molded or cut into the exterior surface 18 of the front panel 12 to accommodate the positioning and nesting of battens (not shown). The grooves 20 allow for one or more battens to be positioned and retained in the groove so as to provide ease in properly positioning the batten for attachment to the panel(s) and frame. The grooves can be produced at various depths. For example, the grooves may be molded or cut to provide for a flush fit with the battens so as to provide a flat exterior face 18 of the panel 12 . Alternatively, the grooves 20 may be molded or cut to be shallower than the width of the batten. In such embodiments, the batten top may extend past the top of the groove 20 , thereby allowing for a gap to be created between the top of the batten 20 and the top of the groove 20 . This gap allows for airflow between the panels 12 and any protective and/or decorative cladding that may be attached to the battens 14 . Such a gap provides the benefits of releasing heat and moisture that could build up in the insulation system and allowing further airflow.
[0075] FIGS. 9-10 depict top views of a partially completed and completed building insulation sheathing system of the present invention installed around the exterior frame of a building. As illustrated in FIG. 9 , full size panels 12 are positioned around the building and secured to the exterior surface of the studs 24 of the frame, thereby allowing the excess panel portions 26 to hang over the corners of the building. In alternative embodiments, for example in remodeled buildings, the sheathing system 10 may be secured to the frame that includes plywood attached to the exterior side of the studs after the cladding has been removed from the building being remodeled. Once a complete row of panels 12 or all of the panels 12 are secured to the frame/studs with one or more fasteners 16 , the excess portions 26 may be trimmed off to square the corners of the building as illustrated in FIG. 10 . Following trimming of the excess portions 26 , the insulation sheathing system 10 is ready to accept cladding that can be attached to the battens 14 .
[0076] It is noted that the building insulation sheathing systems 10 of the present invention may also be used to insulate ceilings and roofs. FIGS. 11 and 12 provide illustrations of embodiments of the present invention that may be used to insulate ceilings. In various embodiments of the present invention, the panels 12 may be secured to the exterior surface of the trusses 28 of a ceiling or roof or to the sheeting material, such as plywood (not shown), secured to the trusses. Once the panels 12 are secured to the roof (i.e. the trusses or plywood), the roofing materials (e.g. shingles) can be secured to the battens of the insulation sheathing system or to another layer of sheeting material (e.g. plywood.)
[0077] FIG. 12 depicts one embodiment of the building insulation sheathing system that may be used to insulate ceilings and/or roofs. The sheathing system 10 is very similar to the system of the present invention used to insulate walls and includes one or more panels 12 , one or more battens 14 and one or more fasteners for securing the panels to the battens and then the battens/panels to the trusses or sheeting material. The panels 12 used for insulating ceilings may also include beveled edges 22 that are sloped downward and away from the exterior surface of the roof, thereby reducing the accumulation of moisture in the seams 23 between panels 12 . Furthermore, any seams 23 created between panels 12 are normally filled with an sealing material, such as insulation foam, caulk, adhesive and/or sealing tape.
[0078] Additionally, the building insulation sheathing system 10 of the present invention are easy to use in buildings that include windows, doors and other portal type entries into the building. FIG. 13 depicts an exploded view of a window installation that includes the building insulation sheathing system of the present invention. In FIG. 13 a plurality of panels 12 are secured to the stud wall or frame (not shown) of the building. In certain situations, the panels 12 may be trimmed so that the portal opening 30 for doors or windows remains clear for acceptance of the window 32 . In this embodiment the portal opening 30 is framed with a plurality of battens 14 . A molding 34 is next positioned in the lower portion of the opening 30 and a portal weather barrier 36 is positioned around the rough opening 30 to assist in sealing the window structure. The window 32 is next placed and secured into the opening and then tape sides 38 and head flange 40 are administered to the side and top of the window opening 30 . Finally, a flashing 42 is secured over the window and foam is used to seal the edges. It is noted that doors and other open enclosures may be installed in a similar way.
[0079] FIGS. 14-21 depict embodiments of the building insulation sheathing system of the present invention installed in completed building structures and will be used to describe various embodiments of the methods of using such a system. FIG. 14-16 illustrate a cross section side view of a constructed building that includes the building insulation sheathing system of the present invention. In this embodiment a plurality of panels 12 are secured to the foundation walls 44 (e.g. concrete block or poured concrete wall) and frame/studs 24 of the building 46 with one or more fasteners (e.g. screws, nails, adhesives, tapes). Battens 14 are also adjoined to the exterior surface of the panels 12 with either the same or different fasteners as used to attach the panels 12 . The attachment of the battens 14 is intended to provide a stable surface for the attachment of cladding 48 , but may also be used as a platform to stabilize fasteners, such as screw and nails, that are driven into the panels 12 , frame 24 and foundation wall 44 .
[0080] In some embodiments of the present invention, as depicted in FIGS. 17 , 18 and 21 , the panels 12 are positioned over the studs 24 and/or foundation wall 44 of a wall and battens 14 are placed in the grooves 20 that are cut or molded into each of the panels 12 . Once the battens 14 are placed in the grooves 20 , fasteners 16 , such as screws or nails, are driven through the battens 14 and panels 12 and into the studs 24 and/or foundation wall 44 thereby securing the battens 14 and panels 12 to the studs/foundation wall 24 , 44 .
[0081] Once the panels 12 and battens 14 are secured to the frame/studs 24 and/or foundation wall 44 with fasteners 16 , the excess portions (not shown) of panels 12 and battens 14 are trimmed to square corners and open window, door and other portal apertures. It is noted that in many embodiments, the seams 23 between panels 12 are filled with a thermal sealing material, such as insulation foam (e.g. spray foam), caulking, adhesive or tape, to form a substantially continuous thermal seal throughout the system. The sealing material may be administered from the exterior side or interior side of the panels. For example, in remodel applications the sealing material may have to be administered from the front/exterior side of the panel. The creation of such a seal maintains the R-value of the insulation system and limits any moisture that may accumulate in the system or migrate into the frame of the building. The completion of trimming and seam filling next allows for the installation of portal devices 50 , such as windows or doors as illustrated in FIGS. 15 and 16 . Once all portal devices 50 have been installed, cladding 48 is attached to the battens 14 to complete the protective and decorative finishes to the building.
[0082] The building may also include a waterproof barrier material 52 (e.g. waterproof panel or film) applied to the battens 14 and over the panels 12 that are secured to the foundation wall 44 or concrete footing to provide a moisture barrier between the building foundation wall and the aggregate/fill material 54 surrounding the underground portion of the building 46 . Such a barrier protects the system and foundation wall from moisture, but also protects the insulation panels from insect and rodent infestation.
[0083] While the invention has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only embodiments of the systems and methods of the present invention have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | The present invention relates to a building insulation sheathing system that provides for efficient installation of insulation, material and labor reduction during installation, as well as provides a stable structure for ease in attachment of protective and/or decorative cladding to a building. The present invention further includes a method for insulating a building using the sheathing system of the present invention. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to on-machine supercalender apparatus adapted to be located at the output side of a paper machine and which comprise both hard and soft calender rolls which form soft calendering nips with each other. More particularly, this invention relates to on-machine supercalender apparatus wherein the calender rolls are arranged in at least three roll groups each of which consists of three rolls and wherein the roll groups are arranged separate from each other, i.e., the rolls of different roll groups are neither directly nor indirectly in nip contact with each other.
The calendering of a paper web leaving the discharge end of a paper machine is a well known final finishing treatment for determining the smoothness and gloss of the surfaces of the paper as well as its consistency or density. Such calendering is generally accomplished by guiding a continuous paper web successively through a series of nips formed by calender rolls.
Conventionally, a paper web is calendered in a so-called machine calender directly connected to the output side of the paper machine and, when required, the treatment is completed in a separate so-called supercalender.
Calender apparatus comprise calender rolls which define calender nips through which the web is passed. Such calender rolls constitute either "hard" rolls or "soft" rolls. It is understood that as used herein, the term hard rolls designates rolls formed, for example, of chill casting or steel, the hard surfaces of which have been ground smooth. The term soft rolls as used herein designates rolls whose surfaces are made of flexible or resilient material. For example, a resilient material generally used for such soft rolls is paper wrapped in layers around the shaft of the roll and compressed to form a uniform roll coating.
Furthermore, as used herein, the term ¢soft nip" designates the contact line between a soft roll and a hard roll. The term "hard nip" is used to designate the contact line formed between two hard rolls.
It is possible depending upon the type of paper and the requirements therefor to machine-calender the paper web in a single nip calender, i.e., a calender comprising only one pair of rolls. In most cases, however, a machine-calender will comprise four to eight rolls forming three to seven nips.
It is usually an object in supercalendering operations to provide both sides of the paper web with an equal gloss. Accordingly, at least two soft nips are provided located in a manner such that both surfaces of the paper web are pressed against the surface of a hard roll. Separate supercalender apparatus can comprise up to ten nip pairs.
In connection with improving the efficiency of paper production, it has become important to provide calender apparatus in which both the functions of a machine calender as well as a supercalender are combined. In this connection, Finnish patent application No. 761764 discloses an on-machine supercalender apparatus adapted to be connected to a paper machine. This supercalender comprises a stack of rolls including conventional hard rolls and essentially the same number of soft rolls which are located outside of the roll stack to form soft nips against the hard rolls.
In such calender apparatus which combine the functions of both a machine calender and a supercalender, the paper web can be supercalendered as desired immediately after the same leaves the paper machine without any intermediate phases. However, the results obtained are not entirely satisfactory in that the so-called super gloss obtained by the paper by such calendering treatment is not uniform. In other words, some areas of the surface of the paper are glossier than other areas. Furthermore, it has been found that the paper web subjected to the calendering treatment turns a blackish color resulting at least partially from the fact that the hard nips are in fact too hard and insufficiently flexible or resilient.
As to the state of the art relative to the present invention, reference is made to Finnish Pat. No. 55694 and Finnish patent applications Nos. 793200 and 793201.
Thus, the starting point of the present invention is the observation that soft rolls of a calender, such as the paper rolls described above, are easily damaged during operation. This is disadvantageous in that the ratio of down time to production time becomes quite high.
Conventional calenders are known which are composed of groups of three or more rolls. It has not been possible in such calenders to replace a soft roll when the same is damaged during operation of the machine. In certain conventional four nip calenders, although it is possible to change a soft roll during operation without breaking the web, this results in one surface of the web being totally uncalendered.
As mentioned above, the soft rolls utilized in supercalendering become worn relatively rapidly and frequently become damaged during operation. On the other hand, since the decision to utilize an on-machine supercalender instead of the traditional supercalender depends on the extent to which the output of production of the paper machine is reduced due to the use of the on-machine supercalender located at the output end of the paper machine, it is of primary importance to minimize the duration of interruptions in production incurred during replacement of the calender rolls and especially the soft calender rolls.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide new and improved calender apparatus having an improved output, i.e., where the ratio of down or standing time to production time is minimized.
Another object of the present invention is to provide new and improved calender apparatus wherein the duration of production interruptions is minimized and wherein at the same time the number of rolls in the calender can be maintained relatively low.
Still another object of the present invention is to provide new and improved calender apparatus wherein a damaged soft roll can be replaced during continued operation of the apparatus.
According to the present invention, these and other objects are obtained by providing calender apparatus including groups of calender rolls, each roll group including a central, hard calender roll and two outer, soft calender rolls forming soft calendering nips with the hard central roll and wherein at least a majority of the soft rolls can be replaced while the apparatus is in operation without any significant interruption in production.
DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:
FIG. 1 is a schematic side elevation view of one embodiment of calender apparatus according to the present invention;
FIG. 2 is a schematic side elevation view of another embodiment of calender apparatus according to the present invention; and
FIGS. 3A, 3B and 3C are schematic illustrations showing three different alternatives by which the paper web is drawn through the calender apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein like reference characters designate identical or corresponding parts throughout the several views, and more particularly to FIGS. 1 and 2, the calender apparatus includes frame structure constituted by frame columns 10 and 11. In the embodiment illustrated in FIG. 1, horizontally extending frame projections 12 and 13 extend from the upper ends of frame columns 11 and 10, respectively. Further, a relatively long horizontal frame projection 14 extends from a lower portion of the frame column 10 in both embodiments.
Referring to FIG. 1, a first calender roll group R 1 is mounted in a manner described below to the frame components 11 and 12 while calender roll groups R 2 and R 3 are mounted on respective sides of the frame column 10. In the embodiment of FIG. 2, the first calender roll group R 1 is mounted on frame column 10 while the third calender roll group R 3 is mounted in opposed relationship to the calender roll group R 1 to frame column 11 while the second calender roll group R 2 is mounted on the rear side of frame column 11 as viewed in the direction of the run of web W.
According to the present invention, each of the calender roll groups R comprise three calender rolls. More particularly, each calender roll group R includes a central hard roll 21 such, for example, as a chill-cast roll, and two outer soft calender rolls 20a and 20b such, for example, as paper rolls described above. Further, a guide roll 23 is preferably associated with each of the calender roll groups although this is not necessary in all cases.
Each of the calender roll groups R therefore includes two soft nips through which the web W passes, the web W being detached from the hard central roll 21 to pass over the guide roll 23. Thus, roll group R 1 defines calendering nips A 1 and A 2 , roll group R 2 defines calendering nips B 1 and B 2 and roll group R 3 defines calendering nips C 1 and C 2 .
Traction nips D are provided in each of the embodiments illustrated in FIGS. 1 and 2 which function so as to facilitate the guidance and running of the web W, such traction nips not having any calendering or polishing function. More particularly, the calender apparatus illustrated in FIG. 1 include traction nips D 1 and D 2 while the apparatus illustrated in FIG. 2 include traction nips D 2 and D 3 . The traction nips D are formed, for example, between a lower hard roll 24a, 25a, 26a and an upper, rubber-coated roll 24b, 25b and 26b, respectively. The hard lower rolls 24a, 25a, 26a are mounted on bearing supports which are rigidly fastened to the frame structure while the upper rubber-coated rolls 24b, 25b, 26b are mounted on bearing supports which are connected to arms 44 which are pivotally connected by brackets 43 to the frame structure. Power units 45 are associated with the outer ends of arms 44 so that the latter can be pivoted to open and load the traction nips D.
Referring to the calender rolls 20a, 20b and 21 which comprise the calender roll groups, the upper soft calender rolls 20b are mounted on bearing supports which are connected to the frame structure in a rigid manner by means of stationery supports 33. The central, hard calender rolls 21 are, however, mounted in bearing supports which themselves are articulated to the frame structure 10 and 11 so that the central rolls 21 of each roll group R can move in a substantially vertical plane. In the illustrated embodiment, this connection is accomplished by means of the roller 21 being mounted in bearing supports which are fastened at pivot points 34 to supports arms 38. Stop members 40 (FIG. 2) are provided on the frame structure for limiting the pivotal movement of support arms 38 and to thereby limit the lowermost position to which the central rollers 21 can move, the rollers 21 being capable of being raised from this lower position.
The lower soft calender rolls 20a of each roll group R are mounted in bearing supports which are themselves mounted on supports 35 which are pivotally connected at pivot points 36 to the frame columns 10 and 11. The supports 35 in the FIG. 2 embodiment are connected to arms 37 whose outer ends are acted upon by power units 39. In the embodiment of FIG. 1, the supports 35 are directly acted upon by the power units 39. These power units 39 may comprise, for example, hydraulic or pneumatic cylinders and upon their actuation, the supports 35 can be pivoted to thereby load the nip pairs A, B and C with the desired line pressure necessary to perform calendering. Upon deactuation of the power units 39, the nip pairs A, B and C are opened in a rapid manner, the stop members 40 acting to limit the extent to which the calender rolls 20a and 21 move downwardly. This in fact contributes to minimizing the duration of production interruption by virtue of the rapid manner in which the nips can be opened.
The portion of the web entering the calender apparatus is denoted in the figures by W in while the portion of the web being discharged from the calender apparatus is designated W out . Further, guide rolls 27 are illustrated in the figures, such rolls functioning to guide the web W through the calender apparatus.
Reeling apparatus 28 are provided at the discharge end of the calender apparatus. Further, apparatus 31 and 32 for metering the moisture of the web are provided at the outlet and inlet sides of the calender, respectively. Guide plates 30 are provided for facilitating the threading of the initial end of the web W through the calender, preferably together with suitable blow devices (not shown). The equipment for threading the end of the web through the calender further includes pairs of ropes 41 and pulleys 42 which are in themselves conventional and need not be described for present purposes.
It is an important feature of the present invention that the soft calender rolls may be easily replaced in a rapid manner when the same are damaged or become worn. Thus, the upper soft calender roll 20b of group R 2 in each of the embodiments illustrated in FIGS. 1 and 2 can be rapidly replaced by using a traverse crane normally found in a paper machine hall. The lower soft calender roll 20a in roll group R 2 can be replaced by lowering the roll 20a onto a car 47 which is provided to traverse the length of the horizontal projection 14 of the frame whereby the car 47 with the roller 20a supported thereon is run to the end of projection 14 whereupon the roller 20a can be lifted from the car by means of the traverse crane. It is preferable to situate replacement rolls at locations proximate to the calender apparatus at appropriate locations relative to the frame structure so that such replacement rolls can be easily and quickly associated with the apparatus after the removal of the worn or damaged soft rolls 20a and 20b. For this purpose, a space T is provided between the calender roll groups R 1 and R 3 both of the embodiments illustrated in FIGS. 1 and 2 in which space equipment for replacing soft rolls are preferably provided.
FIGS. 3A, 3B and 3C illustrate three alternative modes of guiding the web through the calender apparatus in accordance with FIGS. 1 and 2. In all of the illustrated techniques, one group of roll R' is maintained non-operational, i.e., no calendering operation is performed thereby. Such mode of operation recognizes the fact that in most cases, four successive soft nips are generally sufficient to produce the smoothness and glaze properties typical of supercalendered paper. However, it is understood that the scope of the present invention is not limited by the foregoing and that calender apparatus including three or even more roller groups R, each consisting of three calender rolls, are within the scope of the present invention.
Referring to FIG. 3A, the second roll group R 2 ' maintained non-operational and its calendering nips B 1 ' and B 2 ' are maintained open. Both surfaces or faces of the web W will be polished or calendered in accordance with the FIG. 3A guidance of the web.
Referring to FIG. 3B, the first roll group R 1 ' is maintained non-operational mode with its nips A 1 ' and A 2 ' being open. In the mode illustrated in FIG. 3C, the first and second roll groups R 1 and R 2 are maintained operational while the third roll group R 3 ' is maintained non-operational with its nips C 1 ' and C 2 ' being open. In the modes of operation illustrated in FIGS. 3B and 3C, both surfaces of the web W will alternatively contact soft and hard rolls of the apparatus.
Calender apparatus of the present invention may be adapted for automatic operation in a manner such that if one of the calender rolls, e.g. a soft calender roll, is damaged, all of the nips of the calender will be opened and, if required, the path of the web can be changed depending upon where the roll damage occurs, whereupon the nips are closed and the web run along its new path. After the operation of the apparatus is restarted, the damaged roll can be replaced and any other service operations carried out whereupon the group of rolls in which the damage occurred will remain as a ready-reserve roll group, i.e., a non-operational roll group, which can be placed into operation as soon as damage occurs in some other roll group. In this manner, any interruption in production caused by damage to a calender roll will remain of extremely short duration and, at the same time, a number of rolls used in the calender can be kept relatively low.
As seen in FIGS. 3A and 3C, when a soft roll in one of the roll groups R 2 and R 3 is damaged, it is possible to replace the same without interrupting the operation of the calender apparatus since the running of the web W is guided only by hard rolls 21 and 23 in these roll groups. When a calender roll is damaged in the roll group R 1 ', the web is guided as illustrated in FIG. 3B whereupon the damaged roll can be replaced. It is also possible in roll group R 1 to arrange that the web W is run so that it is guided only by hard rolls 21 and 23 as is the case in roll groups R 2 and R 3 . All roll replacement can be performed, for example, by equipment which operates in the area situated on the operating side at the machine level. Such equipment, however, is not included within the scope of the instant invention.
The soft rolls 20a and 20b are preferably deflection-compensated rolls, especially in wider calender apparatus. In some cases, the rolls 21 may also be deflection-compensated rolls. In the case of narrower calenders, so-called deflection-minimized rolls or even conventional rolls not including such compensation can be used.
Obviously, numerous modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the claims appended hereto, the invention may be practiced otherwise than specifically disclosed herein. | On-machine supercalender apparatus adapted to be located at the discharge end of a paper making machine of the type which includes hard and soft calender rolls forming soft calendering nips with each other. The calender rolls are arranged in at least three roll groups, each of the calender roll groups consisting of three calender rolls, namely a central hard calender roll and two outer soft calender rolls. The calender roll groups are separate from each other in that the calender rolls of one group are neither directly or indirectly in nip contact with the calender rolls of another group. At least a majority of the soft calender rolls are replaceable during operation of the apparatus without any significant interruption in operation. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to a clip for holding a first article, such as an under-slung sink, to a second article, such as a work surface, and a method relating thereto.
BACKGROUND TO THE INVENTION
[0002] When fitting an under-slung stainless steel sink to a granite work surface, a strong connection is required. However, the life of a sink is considerably shorter than that of a granite worktop and it is therefore desirable that the sink should be removed and replaced at a later date.
[0003] Granite is an extremely hard material which is very difficult to drill. Conventional clips supplied with stainless steel sinks require drilling of the work surface, and are thus very difficult to use with granite.
[0004] An alternative method of fixing an under-slung sink is to make a softwood frame, place the sink in position on the frame, place silicone sealant around the edge of the sink and fit the granite work surface over the sink. This has the problem that if the sink needs to be replaced, the granite work surface first needs to be lifted. This means that damage to the work top, surrounding tiles and fittings is likely. Replacing an under-slung sink is thus time consuming and costly and may result in a work area around the sink that is damaged.
[0005] A further alternative is to place silicone sealant around the top of the sink, and use a two-part resin to adhere the sink in place. Not only is it time consuming to use the two-part resin, but also problems occur with the resin failing and the sink becoming detached from the work surface. This is potentially unsafe as well as unsatisfactory for the user of the sink.
[0006] An aim of the present invention is to address the problems that the prior art has described herein or elsewhere.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the invention there is provided a clip for holding a first article in contact with a second article, comprising a first portion for insertion into a groove in the first article and a second portion abutting against the second article, the first portion extending substantially at right angles to the second portion.
[0008] Preferably the clip is adapted such that the greater a separating force between the first and second articles, the stronger the grip of the clip.
[0009] Preferably the clip is resilient. The clip may have a first portion in the form of a shallow V shape.
[0010] Preferably the first portion is adapted to be held in the groove by friction.
[0011] Preferably the first article is a work surface, and may be a kitchen work surface. Preferably, the work surface is granite.
[0012] Preferably the second article is a sink. Alternatively the second article may be a kitchen unit or a support leg.
[0013] Preferably the clip is made of spring steel. Preferably the clip is 2 mm or 3 mm in width.
[0014] Preferably the groove is 15 mm or 22 mm in depth. Preferably the groove is 2.5 mm or 4 mm in width.
[0015] The second article may be a temporary fencing arrangement.
[0016] According to a further aspect of the invention there is provided a clip for holding a sink in contact with a work surface, comprising a first portion for insertion into a groove in the work surface and a second portion abutting against the sink.
[0017] According to a further aspect of the invention there is provided a sink clip as hereinbefore described.
[0018] According to a further aspect of the invention there is provided a sink arrangement comprising a sink and a plurality of clips, wherein the clips are as hereinbefore described.
[0019] According to a further aspect of the invention there is provided a method of attaching a first article to a second article, comprising the steps of cutting at least one groove in the first article, locating the second article on the first article, and inserting each of at least one clips into a corresponding groove to attach the first article to the second article.
[0020] Preferably, the step of cutting the at least one groove in the first article comprises cutting the at least one groove substantially parallel to an edge of the second article. The at least one groove may be cut by means of an angle grinder. The angle grinder may be a 41 ″ angle grinder.
[0021] Preferably, the step of inserting each clip into a corresponding one of said at least one groove comprises partially inserting each clip into the corresponding groove, optionally adjusting the position of the second article, and then fully inserting each clip into the corresponding groove.
[0022] Preferably, the step of partially inserting each clip into the corresponding groove is carried out by means of the fingers of a fitter.
[0023] Preferably, the step of fully inserting each clip into the corresponding groove is carried out by means of a hammer.
[0024] According to a further aspect of the invention there is provided a method of attaching an under-slung sink to a work surface, comprising the steps of cutting a plurality of grooves in the lower surface of the work surface at a distance from an opening in the work surface under which the sink is to be located, locating the sink under the opening, inserting each of a plurality of clips into a corresponding groove.
[0025] Preferably the step of placing silicone around the edge of the sink is carried out before the step of locating the sink in position under an opening.
[0026] According to a further aspect of the invention there is provided a method of attaching a first article to a second article, wherein the clip is as hereinbefore described.
[0027] The present invention includes any combination of the herein referred to features or limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which:
[0029] FIG. 1 is a perspective view of a clip according to a first embodiment of the present invention;
[0030] FIG. 2 is a view from below of a sink installed on a work surface by means of the clips of FIG. 1 ;
[0031] FIG. 3 is a cross sectional view from the side of a sink installed on a work surface by means of the clips of FIG. 1 ;
[0032] FIG. 4 is an enlarged cross sectional view of a clip arrangement of FIG. 3 ;
[0033] FIG. 5 a shows a cross sectional view through the groove of FIG. 4 ;
[0034] FIG. 5 b shows a cross sectional view through the groove of FIG. 4 when an alternative clip is inserted;
[0035] FIG. 6 is a view from below of a leg arrangement for supporting a work surface using the clip of FIG. 1 ; and
[0036] FIG. 7 is a perspective view of a temporary fencing arrangement using a further embodiment of the clip of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] FIG. 1 shows a clip 10 according to a first embodiment of the invention. The clip 10 comprises a first portion 12 and a second portion 14 extending substantially at right angles to the first portion 12 . The clip 10 is designed to have a degree of resilience as will be described below. The clip 10 may be made from 3 mm or 2 mm thick spring steel.
[0038] FIGS. 2 and 3 show a sink 22 which has been attached to the lower surface of a granite work surface 20 by means of clips 10 . The granite work surface 20 has a number of grooves 24 machined into the lower surface, each groove 24 being parallel to the closest edge of the sink 22 . Each groove 24 is 22 mm deep and 4 mm wide or 15 mm deep and 2.5 mm wide, according to the thickness of the clip 10 .
[0039] In use, the sink is placed in position under an opening 26 in the granite work surface 20 . The first portion 12 of each clip 10 is received in a respective groove 24 . The relative size of the first portion 12 of the clip and the groove 24 are determined such that the clip 10 can be partially inserted in the groove 24 using finger pressure, and is held in position in the groove 24 by friction between the first portion 12 and the surface of the groove. In this position the clips 10 are able carry the weight of the sink 22 on their second portions 14 . This enables a fitter to move the sink on the clips until the sink 22 is in the correct position. The clips 10 are also designed such that the first portions 12 can be fully inserted in the respective grooves 24 by tapping with a hammer. In the fully installed position each clip 10 is capable of carrying a greater amount weight placed on the second portion 14 . Indeed, the shape of the clip 10 means that in the fully installed position, as the force on the second portion 14 increases, the clip 10 becomes more strongly wedged within the groove 24 .
[0040] The first portion 12 of the clip 10 may have a shallow V shape as illustrated in FIG. 1 and 5 a. The V shape is resilient and provides three areas of strong contact with the inside of the groove. Alternatively, first portion 12 ′ of the clip 10 may be flat, as illustrated in FIG. 5 b. The fact that the work surface 20 is made of granite means that the interior of the groove provides a very hard, high friction surface which is excellent for the clip to engage with.
[0041] An exemplary method of installing an under-slung sink 22 will now be described. The granite work surface 20 is placed with its lower side facing upwards. The sink 22 is placed in the desired position on the lower side of the granite work surface 20 . A line is then drawn around the sink 22 with chalk and the sink 22 removed. At each of the points around the chalk line where it is desired to place a clip 10 , a groove 24 is cut parallel to the chalk line and at 20 mm from the chalk line and externally of the chalk line. Each groove 24 is cut using a 41 ″ angle grinder. The granite work surface 20 is then located in its desired position.
[0042] When attaching the sink 22 to the granite work surface 20 , silicone is first applied around a flange 28 of the sink 22 and the sink 22 lifted into place. The silicone provides a water tight seal between the sink 22 and the granite work surface 20 . The first portion 12 of each of the clips 10 may then be located in a partially inserted position in respective grooves 24 by pressing with a finger or thumb. In the partially inserted position, the clips 10 are sufficiently secure within the grooves 24 to hold the sink 22 in place whilst allowing play between the sink 22 and the work surface 20 . This allows the sink 22 to be accurately aligned and yet be supported by the clips 10 . A hammer, such as a pin hammer, is then used to finally tap the clips 10 to a fully installed position in the granite work surface 20 . This secures the sink 22 firmly between the second portion 14 of the clip 10 and the work surface 20 .
[0043] Once installed, the shape of the clip 10 is such that the more downwards pressure that is applied to the sink 22 , and hence to the second portion 14 of the clip 10 , the more securely the clip 10 is held in the respective groove 24 . The limiting factor for failure of the sink 22 arrangement when under load is therefore likely to be failure of the sink 22 itself.
[0044] The simple design of the clip 10 of the present invention enables the fitter to install an under-slung sink 22 easily and quickly, and also ensures its safeness and sturdiness. A standard sink 22 can be fitted and secured by the clips 10 in around 10 to 15 minutes.
[0045] The clips 10 not only secure the sink 22 to the granite work surface 20 , but is capable of withstanding extreme pressure that may be encountered in retail and domestic environments, such as the weight of an average person.
[0046] When it is desired to replace a sink 22 , the clips 10 can be tapped sideways by means of a hammer to release the sink 22 from the work surface 20 . The clips 10 may have to be tapped several times in opposing directions before they finally work loose. Thus the work surface 20 can remain in position, avoiding unnecessary damage.
[0047] Although the clip 10 has been described above for use in supporting a sink 22 , it could be used in any application where one item needs to be held in close contact with another item. When a separating force is applied to the items the clip 10 serves to hold the items in even stronger contact.
[0048] For example, the clips 10 may be used to fit kitchen units to granite work surfaces. Again, the clips 10 are strong in use, but are easily removable, thus avoiding damage to both the units and the work surfaces.
[0049] FIG. 6 shows a work surface 40 in a kitchen that requires a support leg 42 . The support leg 42 may be provided with a plate fitting 44 . The plate fitting 44 is shown as triangular, but may be any suitable shape. Three grooves 46 are cut in the lower surface of the work surface 40 , one at the centre of each side of the plate fitting 44 , parallel to the side and at a predetermined distance from the side. Each groove 46 receives in use a clip 10 for securing the plate fitting 44 to the lower surface of the work surface 40 as described above.
[0050] FIG. 7 shows temporary safety fencing 60 of the type used to keep pedestrian and/or traffic away from road works. The fencing 60 includes a weighted base 62 to prevent the fencing 60 from falling over. However, this weighting is often not sufficient in high winds or if the fencing 60 is accidentally or deliberately pushed over. One or more larger scale versions 64 of the clip 10 described above may be used to secure the base 62 to a road surface. A first portion 70 of the clip 64 is inserted in a groove 66 cut in the road surface, whilst a second portion 72 of the clip 10 bears on an inner surface of a recess 68 in the base 62 . If a force is applied to the base, tending to lift the base from the tarmac, the clip will apply a counter force to the inner surface of the recess 68 .
[0051] The clip 10 functions most effectively in conjunction with grooves 24 cut in hard surfaces such as granite, but could be used with any other suitable surfaces.
[0052] Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.
[0053] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
[0054] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0055] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0056] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. | A clip for holding a first article in contact with a second article, comprising a first portion for insertion into a groove in the first article and a second portion abutting against the second article, the first portion extending substantially at right angles to the second portion. | 4 |
This application is a continuation of and claims priority from U.S. application Ser. No. 10/326,581 filed Dec. 20, 2002, which issued as U.S. Pat. No. 6,988,905 on Jan. 24, 2006, and incorporates by reference the '581 application as if it were fully printed herein.
FIELD OF THE INVENTION
This invention relates to audio jacks and is directed particularly, but not solely, toward a multifunctional headphone jack for use with noise cancellation systems including noise cancellation headsets in passenger vehicles such as commercial aircraft.
BACKGROUND OF THE INVENTION
Passenger vehicles, particularly commercial aircraft, have seat installations which include jacks i.e. sockets for receiving connector plugs for headsets or headphones. Thus a user can provide his or her own headset, or be provided with a headset by an attendant on the vehicle and can plug the headset into the jack provided on the relevant seat to listen to various audio channels.
Typically, the audio information is provided in the form of an electric signal that is passed by electric connections between the jack and the plug to the headset.
Recent developments to passenger audio systems include noise reduction headphones. There have been many attempts to create noise reduction headphones for use onboard commercial passenger aircraft. There are presently several embodiments of noise reduction systems, and most have their own particular headset plug and jack arrangement.
For example, in one noise reduction system there is an electronic circuit providing noise reduction functionality located in a medallion at arms length and separate to the headphone. The headphone must interface to the noise reduction circuit via a connector and jack of some description. One such connector comprises a standard 3.5 mm stereo plug in combination with a 2.5 mm stereo plug providing six potential signal lines.
In another example, the electronic circuit providing noise reduction functionality is located within or adjacent to the headphone i.e. as an adjunct to the headphones. This circuit may require power and therefore a connector providing stereo audio and power is necessary. One such connector uses a three prong configuration (i.e. three pins from the plug) comprising two 3.5 mm mono plugs in combination with a single 2.5 mm mono plug. This provides the capacity for six independent signal lines, of which four independent signal lines are typically used.
In all cases the use of the three prong jack to enable connection of a headphone with adjunct circuit removes the possibility of easily deploying an alternative system such as that where the noise reduction circuit is located at arms length to the headphone and vice versa. This is because the different plug and jack arrangements mean that to switch from one system to another means changing the jack and associated cabling. Therefore, variations in jack configuration create an unnecessary barrier for the operator to frequently change or upgrade the way in which active noise reduction and audio in general is delivered to passengers via headphones. The other disadvantage with the variations in jack configuration is that it makes it cumbersome to interconnect variations of similar technology, which require, in most cases, the same signal lines to operate.
OBJECT OF THE INVENTION
It is an object of the present invention to provide an improved audio jack or an audio jack with a plug or headset identification circuit. Alternatively, it is an object of the invention to at least provide the public with a useful choice.
SUMMARY OF THE INVENTION
Accordingly in one aspect the invention may broadly be said to consist in an audio jack having plug receiving means for receiving one of a plurality of different audio plugs, each plug having one or more pins, and interface means to enable the jack to identify the equipment attached to the plug.
Preferably the interface means comprise a passive or active electric circuit for identifying the configuration of the plug and/or the contact arrangement of the plug.
Preferably the circuit enables correct electrical connection between an audio source and the plug contacts to be made.
Accordingly in another aspect the invention may broadly be said to consist in an audio jack having plug receiving means for receiving one of a plurality of different audio plugs, each plug having one or more pins, and identification means to enable the jack to identify equipment attached to the plug.
Preferably the identification means identify headset requirements from the plug type and/or the contact arrangement of the plug.
Preferably the headset contains only headphones and the identification means includes an active and/or passive network for providing an interface between the headphones and an audio signal source and the network operates in conjunction with the electric circuit to correctly identify and connect the headphones to the audio signal.
Preferably the plug types identified include one or more of the ARINC (Aeronautical Radio Incorporated) types as currently defined in the ARINC Specifications 628 Part 2.
Preferably the jack includes an appropriate plug socket for each plug pin, one or more of the sockets including detection means to detect the presence of a plug pin.
Preferably the jack includes three pin sockets.
Preferably the pin sockets are arranged in the form of a triangle.
Preferably two plug sockets are 3.5 mm diameter and are sockets capable of receiving stereo pins, and the third plug socket is a 2.5 mm socket capable of receiving at the least a 2.5 mm mono pin.
Preferably the jack is provided in a housing and the at least one moveable socket floats laterally within the housing.
To those skilled in the art to which the invention relates, many changes in constructions and widely different embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosure and descriptions herein are purely illustrative and are not intended to be in any sense limiting.
The invention consists of the foregoing and also envisages constructions of which the following gives examples only.
DESCRIPTION OF THE DRAWINGS
One presently preferred embodiment of the invention will now be described with reference to the accompanying drawings, wherein;
FIGS. 1A , 1 B, and 1 C are plan, front elevational, and side elevations, respectively, of a known three pin headset plug;
FIG. 2 is a diagrammatic elevation of a mono audio plug pin
FIG. 3 is a diagrammatic elevation of a stereo audio plug pin
FIG. 4 shows a side elevation of a headset single stereo plug commonly referenced type A 1 or B 1 ;
FIG. 5 shows a side elevation of a dual mono or dual stereo plug commonly referenced type A 2 or B 2 ;
FIG. 6 shows a side elevation of a known audio plug usually referenced D 2 ;
FIGS. 7A and 7B are a side elevation and end elevation, respectively, of a known plug having two pins commonly referenced type D 1 ;
FIGS. 8A and 8B area side elevation and end elevation, respectively, of a plug having two pins commonly referenced type C 1 ;
FIG. 9 shows an audio jack apparatus according to the present invention and FIG. 9A is a diagrammatic isometric view of a seat shown in broken lines and illustrating installation of the audio jack of FIG. 9 ;
FIG. 10 shows a block diagram illustrating use of the audio jack of the present invention in a headset audio distribution system;
FIG. 11 shows electrical schematic diagrams for exemplary sockets according to the audio jack of the present invention;
FIG. 12 shows a circuit of a comparator adapted to detect the presence of a microphone connected to a plug; and,
FIG. 13 is a table illustrating plug configurations that may be used with the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention overcomes the problem of different headset plugs being incompatible with headset jacks. As discussed above, the problem is particularly prevalent in the commercial airline industry where passengers in different “classes” may be issued with different headsets having different capabilities. Rather than having to change whole seat installations in order to change the jacks, the present invention allows a single multifunctional headphone jack to be used throughout an aircraft, bus or other passenger vehicle so that a number of different types of headset can be used.
The invention achieves this task by providing plug pin sockets that are arranged to allow each common headset type to be plugged into the jack, and by providing the jack system with passive or active detection means to detect, from the plug pins that have been inserted into the socket, the type of plug and thus the type of headset so that the required audio and other signals can be provided to the necessary plug conductors to enable the connected headset to function correctly. As mentioned above, the invention is particularly applicable to noise reduction headphone systems.
In order to fully understand the operation of the jack of the present invention, it is helpful it have a general understanding of headset types. Airline entertainment headphones have been categorised by ARINC into four different types, A, B, C and D. Types A and B are older types. Types C and D are intended for use with noise cancellation (NC) systems. Type C headphones incorporate NC electronics, and Type D are similar to type C except that the NC electronics is installed remotely in the seat area.
A summary table of airline entertainment system headphones is provided below.
TABLE 1
HEADPHONE
IMPEDANCE
TYPE
Ohms
PLUG STYLE
A1
300
Single prong, right angle
A2
300
Dual prong., right angle
B1
40
Single prong, right angle
B2
40
Dual prong, right angle
C1
High
Dual prong, right angle
C2
High
Triple prong, right angle
D1
300
Dual prong, right angle
D2
300
Dual prong, right angle
Further information can be found from the ARINC (Aeronautical Radio Incorporated) Specifications 628 Part 2, which is publicly available.
It is also helpful to have some understanding of headset types for noise cancellation systems. Existing and proposed headset types are set forth below.
Type 1
This headset has a three pin plug for which an associated three socket jack is required. This is usually installed into the armrest of the passenger seat. The plug is shown in FIGS. 1A-1C , having two 3.5 mm mono plug pins 1 and one 2.5 mono plug pin 2 . It is commonly known as an ARINC “C2” plug, as will be described further below.
A mono pin is shown in FIG. 2 in which it can be seen that the pin has two conductors, being a ring 21 and a tip 22 .
A stereo plug pin is shown in FIG. 3 from which it can be seen that the pin has three conductors, being a first ring 31 , and second ring 32 , and a tip 30 .
Returning again to FIGS. 1A-1C , the 2.5 mm pin supplies power to the noise cancelling electronics located in or adjunct to the headset. The noise cancellation (NC) electronics typically connect to the jack with preferably a six-conductor cable. Two of these conductors are for power, one conductor for program audio left, one conductor for program audio right and two conductors for audio left ground and audio right ground. Therefore, the jack for this type of headset is one that is designed to accept mono plug pins, not stereo plug pins.
Between the NC circuit medallion and the headset's transducers are separate cables of two leads, each with four conductors. These provide program audio to the two speakers and noise signal from the two sensors. The sensor conductors are shielded.
Type 2
This is a variant of the Type 1 headset. The plug of this type of noise cancellation headset connects to a jack comprising a single 3.5 mm stereo socket and a 2.5 mm stereo socket. The headset is fed programme audio from the passenger seat remote jack unit via the 3.5 mm stereo sockets. Power is provided to the headset's NC circuit via the 2.5 mm stereo socket.
Type 3
This headset does not comprise any noise cancellation circuitry and relies on an audio signal that has already been processed to provide noise cancellation. Therefore, the NC circuitry is provided adjunct to the headphone, typically in the seat or within the remote jack unit itself. Control features on the headset may be provided. The control features do not include a noise cancellation circuit, but do include a volume control and an NC gain control. These may both be provided in the form of variable resistors. These control features do not alter the number of conduction paths required or the configuration of the sockets in the jack.
The cable from the jack to the headset or circuit is preferably seven-conductor assembly (two conductors for audio left and right, two audio grounds and two shielded cables for the sensor left and right).
Type 4
This is a variant of the Type 2 headset and is proposed at the present time. It is planned as a personal headset to be sold to passengers who wish to buy an NC headset for personal audio use. This model will have battery power for use with 32 ohm low voltage sources. The batteries will be located in the headset or adjunct to the headset in a box or medallion. Again, these requirements can be supplied using a plug according to the invention.
As well as the noise cancellation headset types discussed above, it is desirable if the seat jack unit is provided with means to supply headsets, which are not noise cancellation headsets i.e. to supply simply mono or stereo audio without noise cancellation. Known jack arrangements for commercial aircraft are specified by ARINC (Aeronautical Radio Inc). FIG. 4 shows a standard airline single stereo plug, commonly referenced type A 1 and type B 1 .
FIG. 5 shows a standard airline dual mono and dual stereo plug, commonly referenced type A 2 and type B 2 . FIG. 6 shows a standard dual stereo type airline plug, which is usually, referenced D 2 .
FIGS. 7A and 7B show an ARINC two pin plug, which is commonly called a type D 1 plug.
A table, referenced table 2 below, shows the use for each of the conductors provided on the pins of the plug discussed above.
TABLE 2 Dual Mono and ARINC ARINC Dual Stereo Single Stereo SMART Jack 3 pin (C2) 2 pin (D1) (D2, A2, B2) (Al, B1) 2.5 mm pin Tip Control common Power+ Ignored Not present Not present 2.5 mm sleeve 1 Control 1 Power− Ignored Not present Not present 2.5 mm ring 2 Optional Not present Ignored Not present Not present 3.5 mm right tip Program audio Program audio Program audio Program audio Program audio right right right right right 3.5 mm right sleeve 1 Noise sensor Program audio Program audio Not present or Program audio right return right left right Noise left sensor 3.5 mm right ring 2 Audio and noise Not present Program audio Program audio Program audio return right same as ring 1 return right return return 3.5 mm left tip Program audio Program audio Program audio Program audio Program audio left left left left left 3.5 mm left sleeve Noise sensor Program audio Program audio Not present or Program audio left left return right left Noise right sensor 3.5 mm left ring 2 Audio and Not present Program audio Program audio Program audio noise return left same as ring 1 return left return return
Also shown in table 1 is a column for the jack of the present invention, which is headed “smart jack”. This column shows the use, which may be made of the conductors from the pin sockets in the multifunctional jack of the present invention.
The jack of the present invention is shown in FIG. 9 generally referenced 90 . As can be seen, it comprises two 3.5 mm plug sockets ( 92 , 93 ) and a 2.5 mm plug socket 94 connected to a seat circuitry connector 91 . The sockets are all capable of receiving pins, which have two or more conductors. This has the significant advantage that there is a maximum of nine possible conductors provided by the jack of the present invention. It will be seen that the plug sockets are arranged in a triangular form, which is compatible with that of the ARINC three pin triangular C 2 plug. Furthermore, since a 2.5 mm socket is provided as well as a 3.5 mm socket, the jack of the present invention is able to receive an ARINC two pin (D 1 ) plug. Since two spaced 3.55 mm plug sockets are provided, the jack of the present invention enables existing dual mono and dual stereo plugs D 2 , A 2 and B 2 to be used. Also, a single stereo i.e. A 1 or B 1 plug can also be received.
In FIG. 9A the audio jack 90 is shown installed in the armrest of a seat 95 . The audio jack 90 is connected to an audio signal source and typically noise cancellation circuitry provided in the seat via connector 1003 .
There is also a mechanical consideration. Due to slight differences in the construction of plugs and pins it is highly desirable to allow some movement in the jack assembly. Thus, in the preferred embodiment, one (preferably the 2.5 mm) or more of the jack sockets (or jacks) is allowed to “float” in the assembly. This is because the distance between the 2.5 mm pin and 3.5 mm pin in the C 2 plug is slightly smaller (0.466 inches) than the D 1 , D 2 plug (0.500 inches). The degree of tolerance for this dimension needs to be in the order of 0.05 inches on the angle from the axis of the 2.5 mm jack to the 3.5 mm jack. The tolerance is indicated in FIG. 9 . Without this mechanical allowance the plug will be under strain and proper contact cannot be assured.
Referring again to table 1, it will be seen that in order to operate the different noise cancelling headsets referred to above, and standard headsets, which use the various plugs of table 1, appropriate connections need to be made from the “smart jack” of the present invention to the circuitry in the passenger seat or in the jack itself.
Referring to FIG. 10 , a block diagram is shown illustrating an interface 1001 which is provided between the smart jack 1002 and the audio signal provided to a seat connector 1003 . The headset to which the jack is connected in use is referenced 1004 .
The interface 1001 , in the preferred embodiment, comprises an active or passive network which is either enabled by or partially consists of, sockets in the jack of the present invention which provide an indication as to whether a pin has been inserted in the relevant socket.
In FIG. 11 examples of electrical schematic diagrams for a typical socket are shown. Each of the arrangements in FIG. 11 may be used to detect a plug pin type. As can be seen, the socket has electrical contacts, which enable up to three conductors on a plug pin to be electrically connected to the socket. In particular, the conductor at the tip of the pin can open or close a connection between the adjacent conductors. This means that a signal is provided as to whether a pin is fully inserted into a relevant socket. Therefore a logic table can be constructed to enable an identification to be made of the type of plug which has been inserted into the socket, and from that identification of the relevant headset can be made. Therefore, the appropriate connections from the audio signal provided in the seat to the headset can be made. Also, in the relevant instance, the appropriate connections can be made from noise cancellation circuitry provided in the seat to the relevant headset. By way of example, if only one of the 3.5 mm sockets and no other sockets register insertion of a pin, then it can be deduced that a single stereo plug has been inserted into the jack. If both the 3.5 mm plugs and not the 2.5 mm plug indicate that pins have been received in those sockets, then it can be deduced that the plug is of type A 2 B 2 or D 2 . Also from knowing whether there is a short between the conductors preceding the socket tip conductors, it will be know whether the pin that have been inserted are mono or stereo i.e. a distinction can be made between A 2 and B 2 and a D 2 type plug.
Such deduction can also be carried out electronically by analysing the loading effect that a microphone would provide if connected in circuit to two of the conductors.
FIG. 12 illustrates such an approach with a voltage comparator where
V bias >V h >V in >V l >V e .
The window comparator detects whether the microphone dc voltage is within the range V h to V l . A resistor in parallel to the microphone defines a minimum microphone load which, in conjunction with the pull up resistor, ensures that V h >V in >V l giving a high output from the comparator to enable noise cancellation circuitry.
If the microphone is disconnected then V in will equal V bias through the action of the pull up resistor and since V bias >V h the enable output will be low. If the microphone input is grounded then V in <V l , and the enable output will also be low.
For additional understanding reference maybe made to FIG. 13 , which illustrates how the plug arrangements for type A, B, C and D headsets can all be accommodated by the invention. The plug pin layouts are graphically represented in column C. The pins shown in black in column C illustrate the sleeve/ring/tip conductors of the relevant plug pins used by the audio jack, and the white pins illustrate the unused plug pins. Column A describes the plug type, and column B diagrammatically shows the jack of the invention, with the plug type from column A overlaid in dashed outline.
ADVANTAGES OF THE PREFERRED EMBODIMENTS
From the foregoing, it will be seen that a multifunctional headset jack is provided which allows a number of different headset types to be plugged into the jack, and still perform their expected function, whether the headset is a NC headset or otherwise.
Typically the jack and associated sensing circuitry is intended to allow a user to plug in a headphone of any type from a single plug mono headphone, through to a triple plug noise cancelling type with either internal or external noise cancellation circuitry and still provide the expected result.
Manufacturing tolerances and minor specification differences in the headphone plugs where the plug is two or three pin may be coped with by the floating construction of one of the jack sockets.
VARIATIONS
The sensing circuitry may rely merely on detecting which of the jack sockets supplied have plugs entered by detecting which of the socket switches are closed or open, or it may additionally detect the presence of various impedances or supply voltages across certain of the plug tips, rings and sleeves.
While the sensing circuitry is described as being electronically implemented it is possible to implement it with either simple logic circuitry or with programmable software controlled circuitry which may be updateable remotely. This will allow an already installed system to cope with variations in headsets as the specifications for these change from time to time.
While the sensing circuitry is described in relation to headphones it is equally applicable to headsets containing headphones and microphone.
Finally various other alterations or modification may be made to the foregoing without departing from the scope of this invention. | A jack ( 90 ) typically mounted in an aircraft seat is adapted for use with a variety of headset types. A jack has sockets ( 92, 93, 94 ) accepting any of several different types of plugs associated with different types of noise cancellation headsets or aviation industry headsets including one, two, or three pin types. The jack includes sensing components to correctly detect from the number of pins inserted, and the impedance and/or voltages sensed on those pins, the type of headset being used. With this identification, appropriate connections to the audio source as well as to noise cancellation circuitry may be made to enable the headset to function correctly. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S. application Ser. No. 11/654,083 filed on Jan. 17, 2007, which claims priority to earlier filed U.S. provisional application Ser. No. 60/759,606 filed on Jan. 17, 2006, the entire contents of each of which are incorporated herein by their reference. The electrical energy harvesting power sources disclosed herein are described in detail in U.S. patent application Ser. Nos. 10/235,997 (now U.S. Pat. No. 7,231,874) and 11/116,093 (now U.S. Pat. No. 7,312,557), each of which are incorporated herein by their reference.
GOVERNMENTAL RIGHTS
[0002] This invention was made with Government support under Contract No. DAAE30-03-C1077, awarded by the U.S. Army. The Government may have certain rights in this invention.
BACKGROUND
[0003] 1. Field
[0004] The present invention relates generally to power supplies, and more particularly, to power supplies for projectiles, which generate power due to an acceleration of the projectile.
[0005] 2. Prior Art
[0006] Fuzing of munitions is necessary to initiate a firing of the munition. Currently, there is no reliable and simple mechanism for differentiating an accidental drop of a munition from a firing acceleration, to prevent an accidental drop from initiating a fuzing of the munition. Similarly, there is a need to reliably validate firing and start of the flight of a munition. For rounds with booster rockets, this capability can provide the means to validate firing, firing duration and termination. Munitions further require the capability to detect target impact, to differentiate between hard and soft targets and to provide a time-out signal for unexploded rounds. Lastly, in order to recover unexploded rounds (munitions) it would be desirable for the munition to have the capability to notify a recovery crew.
SUMMARY
[0007] The power sources/generators/supplies disclosed in U.S. patent application Ser. Nos. 10/235,997 and 11/116,093 are based on the use of piezoelectric elements. Such power sources are designed to harvest electrical energy from the firing acceleration as well as from the aerodynamics induced motions and vibration of the projectile during the entire flight. The energy harvesting power sources can withstand firing accelerations of over 100,000 Gs and can be designed to address the power requirements of various fuzes, communications gear, sensory devices and the like in munitions.
[0008] The electrical energy harvesting power sources are based on a novel approach, which stores mechanical energy from the short pulse firing accelerations, and generates power over significantly longer periods of time by vibrating elements, thereby increasing the amount of harvested energy by orders of magnitude over conventional methods of directly harvesting energy from the firing shock. With such power sources, electrical power is also generated during the entire flight utilizing the commonly present vibration disturbances of various kinds of sources, including the aerodynamics disturbances or spinning. Such power sources may also be used in a hybrid mode with other types of power sources such as chemical reserve batteries to satisfy any level of power requirements in munitions.
[0009] While the piezoelectric power generators are generally suitable for many applications, they are particularly well suited for low to medium power requirements, particularly when safety and very long shelf life are critical factors.
[0010] The electrical energy harvesting power sources for munitions are based on a novel use of stacked piezoelectric elements. Piezoelectric elements have long been used in accelerometers to measure acceleration and in force gages for measuring dynamic forces, particularly when they are impulsive (impact) type. In their stacked configuration, the piezoelectric elements have also been widely used as micro-actuators for high-speed and ultra-accuracy positioning applications with low voltage input requirement and for high-frequency vibration suppression. The piezoelectric elements have also been used as ultrasound sources and for the generation and suppression of acoustic signals and noise.
[0011] In the present application, the electrical energy harvesting power sources are used for powering fuzing electronics as acceleration and motion sensors, acoustic sensors, micro-actuation devices, etc., that could be used to enhance fusing safety and performance. As such, the developed electrical energy harvesting power sources, in addition to being capable of replacing or at least supplementing chemical batteries, have significant added benefits in rendering fuzing safer and enhancing its operational performance. Fir example, the piezoelectric-based electrical energy harvesting power sources can provide the following safety and performance enhancing capabilities:
1. Capability to detect accidental drops and differentiate them from the firing acceleration. 2. Capability to validate firing and start of the flight. For rounds with booster rockets, this capability will provide the means to validate firing, firing duration and termination. 3. Capability to detect target impact. 4. Capability to differentiate between hard and soft targets. 5. Capability to provide time-out signal for unexploded rounds. 6. In an unexploded round, the capability to detect acoustic and vibration wake-up signals generated by a recovery crew and respond to the same via an RF or acoustic signal or the like.
[0018] Accordingly, a system is provided for recovering an unexploded munition. The system comprising: a power supply having a piezoelectric material for generating power from an induced vibration; and a processor operatively connected to the power supply for monitoring an output from the power supply after the power supply has stopped generating power from a firing of the munition and generating a beacon signal upon the detection of the output.
[0019] The beacon signal can be a radio-frequency signal.
[0020] The beacon signal can be coded with additional information. The additional information can location data from a GPS receiver.
[0021] Also provided is a method for recovering an unexploded munition. The method comprising: providing the munition with a power supply having a piezoelectric material for generating power from an induced vibration; inducing a vibration; monitoring an output from the power supply after the power supply has stopped generating power from a firing of the munition; and generating a beacon signal upon the detection of the output.
[0022] The method can further comprise coding the beacon signal with additional information.
[0023] Still yet provided is a method for detonating an unexploded munition. The method comprising: providing the munition with a power supply having a piezoelectric material for generating power from an induced vibration; inducing a vibration; monitoring an output from the power supply after the power supply has stopped generating power from a firing of the munition; and generating a detonation signal upon the detection of the output to detonate the munition.
[0024] The method can further comprise transmitting a second detonation signal for detonation of at least one other unexploded munition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other features, aspects, and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
[0026] FIG. 1 illustrates a schematic cross section of an exemplary power generator for fuzing of a munition.
[0027] FIG. 2 illustrates a schematic view of a system of harvesting electric charges generated by the power generator of FIG. 1 .
[0028] FIG. 3 illustrates a longitudinal acceleration (firing force, which is equal to the longitudinal acceleration times the mass of the round) versus time plot for a fired munition.
DETAILED DESCRIPTION
[0029] In the methods and apparatus disclosed herein, the spring end of a mass-spring unit is attached to a housing (support) unit via one or more piezoelectric elements, which are positioned between the spring end of the mass-spring and the housing unit. A housing is intended to mean a support structure, which partially or fully encloses the mass-spring and piezoelectric elements. On the other hand, a support unit may be positioned interior to the mass-spring and/or the piezoelectric elements or be a frame structure that is positioned interior and/or exterior to the mass-spring and/or piezoelectric elements. The assembly is provided with the means to preload the piezoelectric element in compression such that during the operation of the power generation unit, tensile stressing of the piezoelectric element is substantially avoided. The entire assembly is in turn attached to the base structure (e.g., gun-fired munitions). When used in applications that subject the power generation unit to relatively high acceleration/deceleration levels, the spring of the mass-spring unit is allowed to elongate and/or compress only within a specified limit. Once the applied acceleration/deceleration has substantially ended, the mass-spring unit begins to vibrate, thereby applying a cyclic force to the piezoelectric element, which in turn is used to generate electrical energy. The housing structure or the base structure or both may be used to provide the limitation in the maximum elongation and/or compression of the spring of the mass-spring unit (i.e., the amplitude of vibration). Each housing unit may be used to house more than one mass-spring unit, each via at least one piezoelectric element.
[0030] In the following schematic the firing acceleration is considered to be upwards as indicated by arrow 113 .
[0031] In FIG. 1 , power generation unit 100 includes a spring 105 , a mass 110 , an outer shell 108 , a piezoelectric (stacked and washer type) generator 101 , one socket head cap screw 104 and a stack of Belleville washers 103 (each of the washers 103 in the stack is shown schematically as a single line). Piezoelectric materials are well known in the art. Furthermore, any configuration of one or more of such materials can be used in the power generator 100 . Other fasteners, which may be fixed or removable, may be used and other means for applying a compressive or tensile load on the piezoelectric generator 101 may be used, such as a compression spring. The piezoelectric generator 101 is sandwiched between the outer shell 108 and an end 102 of the spring, and is held in compression by the Belleville washer stack 103 (i.e., preloaded in compression) and the socket head cap screw 104 . The mass 109 is attached (e.g., screwed, bonded using adhesives, press fitted, etc.) to another end 106 of the spring 105 . The piezoelectric element 101 is preferably supported by a relatively flat and rigid surface to achieve a relatively uniform distribution of force over the surface of the element. This might be aided by providing a very thin layer of hard epoxy or other similar type of adhesives on both contacting surfaces of the piezoelectric element. The housing 108 may be attached to the base 107 by the provided flange 111 using well known methods, or any other alternative method commonly used in the art such as screws or by threading the outer housing and screwing it to a tapped base hole, etc. The mass 109 is provided with an access hole 110 for tightening the screw 104 during assembly. Between the free end 106 of the spring and the base 107 (or if the mass 109 projects outside the end 106 of the spring, then between the mass 109 and the base 107 ) a gap 112 is provided to limit the maximum expansion of the spring 105 . Alternatively, the gap 112 may be provided by the housing 108 itself. The gap 112 also limits the maximum amplitude of vibration of the mass-spring unit.
[0032] During firing of a projectile (the base structure 107 ) containing such power generation unit 100 , the firing acceleration is considered to be in the direction 113 . The firing acceleration acts on the mass 109 (and the mass of the spring 105 ), generating a force in a direction opposite to the direction of the acceleration that tends to elongate the spring 105 until the end 106 of the spring (or the mass 109 if it is protruding from the end 106 of the spring) closes the gap 112 . For a given power generator 100 , the amount of gap 112 defines the maximum spring extension, thereby the maximum (tensile) force applied to the piezoelectric element 101 . As a result, the piezoelectric element is protected from being damaged by tensile loading. The gap 112 also defines the maximum level of firing acceleration that is going to be utilized by the power generation unit 100 .
[0033] When the firing acceleration has ended, i.e., after the projectile has exited the gun barrel, the mechanical (potential) energy stored in the elongated spring is available for conversion into electrical energy. This can be accomplished by harvesting the varying voltage generated by the piezoelectric element 101 as the mass-spring element vibrates. The spring rate and the maximum allowed deflection determine the amount of mechanical energy that is stored in the spring 105 . The effective mass and spring rate of the mass-spring unit determine the frequency (natural frequency) with which the mass-spring element vibrates. By increasing (decreasing) the mass or by decreasing (increasing) the spring rate of the mass-spring unit, the frequency of vibration is decreased (increased). In general, by increasing the frequency of vibration, the mechanical energy stored in the spring 105 can be harvested at a faster rate. Thus, by selecting appropriate spring 105 , mass 109 and gap 112 , the amount of electrical energy that can be generated and the rate of electrical energy generation can be matched with the requirements of a projectile.
[0034] In FIG. 1 , the spring 105 is shown to be a helical spring. The preferred helical spring, however, has three or more equally spaced helical strands to minimize the sideways bending and twisting of the spring during vibration. In general, any other type of spring may be used as long as they provide for vibration in the direction of providing cyclic tensile-compressive loading of the piezoelectric element.
[0035] The power generation unit 100 of FIG. 1 is described herein by way of example only and not to limit the scope or spirit of the present invention. Other embodiments described in U.S. patent application Ser. Nos. 10/235,997 and 11/116,093 can also be used in the applications described below as well as any other type of power generation unit which harvests electrical energy from a vibrating mass due to the acceleration of a projectile/munition as well as from the aerodynamics induced motions and vibration of the projectile during the entire flight.
[0036] The schematic of FIG. 2 shows a typical system of harvesting electric charges generated by the piezoelectric element of the energy harvesting power generation unit 100 as the mass-spring element of the power source begins to vibrate upon exiting the gun barrel. Electronic conditioning circuitry 202 , well known in the art, would, for example, convert the oscillatory (AC) voltages generated by the piezoelectric element to a DC voltage and then regulate it and provide it for direct use or for storage in a storage device 204 such as a capacitor or a rechargeable battery as shown in the schematic of FIG. 2 . The piezoelectric output is connected by wires 203 to the electronic converter/regulator/charger 202 , the output of which is connected to the storage device (a capacitor or rechargeable battery) 204 by wires 205 , or is used to directly run a load 206 via wires 207 . A processor 208 is also provided for processing information from the output of the power generation unit 100 . Although the processor 208 is shown connected by way of wiring 209 to the electronic conditioning circuitry 202 , it can be connected to or integral with any of the shown components such that it is operative to process the output or output information from the power generation unit 100 .
[0000] Accidental Drop Detection and Differentiation from Firing
[0037] During the firing, the force exerted by the spring element of the power generation unit 100 generates a charge and thereby a voltage across the piezoelectric element that is proportional to the acceleration level being experienced. The generated voltage is proportional to the applied acceleration since the applied acceleration works on the mass of the spring-mass element of the energy harvesting power source (in fact the mass of the piezoelectric element itself as well), thereby generating a force proportional to the applied acceleration level.
[0038] In certain situations and particularly in the presence of noise and at relatively low acceleration levels, the mass-spring system of the power generation unit 100 begins to vibrate and generates an oscillatory (AC) voltage with a DC bias, which is still proportional to the level of acceleration that is applied to the munitions. Hereinafter, when vibratory motion is present, the piezoelectric voltage output is intended to indicate the level of the aforementioned DC bias.
[0039] The level of voltage produced by the piezoelectric element is therefore proportional to the level of acceleration that is experienced by the munitions in the longitudinal (firing) direction. This information is obviously available as a function of time. A typical such longitudinal acceleration (firing force, which is equal to the longitudinal acceleration times the mass of the round) versus time plot may look as shown in FIG. 3 . From this plot, the processor 208 may calculate information such as the peak acceleration (impulsive force) level and the acceleration (firing force) duration, Δt, can be measured. The processor 208 can be dedicated for such calculations or used for controlling other functions of the munition. The plot information can also be used to calculate the average acceleration (firing force) level and the total applied impulse (the area under the force versus time curve of FIG. 3 or the product of the average firing force times the time duration). The amount of impulse that the round is subjected to in its longitudinal (firing) direction is thereby known. In practice, the processor may be used onboard the munitions (or the generally present fuzing processor could be used) to make the above time and voltage (acceleration or firing force) measurements and perform the indicated calculations and provide the safety and fuzing decision making capabilities that are indicated in the remainder of this disclosure.
[0040] However, a round is subjected to such input impulses in its longitudinal direction during its firing as well as during accidental dropping. The level of input impulse due to accidental dropping of the round is, however, orders of magnitude smaller than that of firing.
[0041] For example, consider a situation in which a round is dropped on a very rigid concrete slab, generating around 15,000 G of acceleration in the longitudinal direction (here, it is assumed that the round is dropped perfectly on its base, resulting in the highest possible longitudinal impact acceleration). Assuming that the elastic deformation that occurs during the impact is in the order of 0.1 mm, a conservative estimate of the impact duration with a constant acceleration of 15,000 Gs becomes about 0.04 msec. Now, even if we assume a similar acceleration profile in the gun barrel, but spread it over a time duration of 8 msec (close to what is experienced in many large caliber guns), then the impulse experienced during the firing is (8/0.04) or 200 times larger than that experienced during a drop over a hard surface. This is obviously a conservative estimate and the actual ratio can be expected to be much higher since in most situations, the round is not expected to land perfectly on its base and on a very hard surface and that the firing acceleration is expected to be significantly larger than those experienced in an accidental drop.
[0042] The above example clearly shows that by measuring the impact impulse, accidental drops can be readily differentiated from the firing acceleration by the processor 208 . This characteristic of the present piezoelectric based power generation units 100 can be readily used to construct a safety feature to prevent arming of the fuzing during accidental drops and/or to take some other preventive measures. This safety feature can be readily implemented in the electrical energy collection and regulation electronics of the power source or in the fuzing electronics (e.g., the processor 208 can have an input into the electrical energy collection and regulation electronics 202 of the power source or in the fuzing electronics to prevent fuzing when the calculated impact pulse is below a predetermined threshold value indicative of a firing).
[0000] Firing Validation and Booster firing and Duration Time and Total Impulse
[0043] As was described in the previous section on accidental drop detection and differentiation from firing, the firing impulse as well as its acceleration profile and time duration can be readily measured and/or calculated from the output of the piezoelectric elements of the power generation units 100 by the processor 208 . Similarly, the completion of the firing acceleration cycle and the start of the free flight are readily indicated by the piezoelectric element. In the presence of firing boosters, their time of activation; the duration of booster operation, and the total exerted impulse on the round can also be determined by the processor 208 from the output of the power generation unit 100 .
[0044] As a result, the piezoelectric based power generation units provide the means to validate firing; determine the beginning of the free flight; and when applicable, validate booster firing and its duration.
Target Impact Detection
[0045] During the flight, the munition/projectile is decelerated by aerodynamic drag. Projectiles are commonly designed to produce minimal drag. As a result, the deceleration in the axial direction is fairly low. In addition, there may also be components of vibratory motions present in the axial direction. Axially oriented piezoelectric based power generation units 100 can also be very insensitive to lateral accelerations, which are also usually fairly small except for high spinning rate projectiles.
[0046] When impact occurs (assuming that the impact force is at least partially directed in the axial direction), the piezoelectric elements of the power generation units 100 experience the resulting input impact, including the time of impact, the impact acceleration level, peak impact acceleration (force) and the total impact impulse. As a result, the exact moment of impact can be detected and/or calculated by the processor 208 from the output of the power generation unit 100 .
[0047] In addition, when desired, lateral impact time, level and total impulse may be similarly detected by employing at least one such piezoelectric based power generation unit 100 in the lateral directions, noting that at least two piezoelectric power sources directed in two different directions in the lateral plane are required to provide full lateral impact information. Alternatively, a single power generation unit 100 can be provided which is aligned offset from an axial direction so as to have a vibration component in the axial direction and a vibration component in the lateral direction. Such laterally directed power sources are generally preferable for harvesting lateral vibration and movements, such as those generated by small yawing and pitching motions of the round.
Hard and Soft Target Detection
[0048] When the munition impacts the target, ground or another object, the munition's deceleration profile can be measured from the piezoelectric element output voltage during the impact period and peak deceleration level, impact duration, impact force and total impulse can then be calculated as previously described using the processor 208 . This information can then be used to determine if a relatively hard or soft target has been hit, noting that the softer the impacted target, the longer would be the duration of impact, peak impact deceleration (force). The opposite will be true for harder impacted targets. This information is very important since it can be used by the fuzing system to make a decision as to the most effective settings.
[0049] It is worth noting at this point that the hard or soft target detection and decision making, in fact all the aforementioned detection and decision making processes, are expected to be made nearly instantly by the power source electrical energy collection and regulation electronics or the fuzing electronics by employing, for example, threshold detecting switches to set appropriate flags.
Time-Out Signal for Unexploded Rounds
[0050] Once a munition has landed and is not detonated, whether due to faulty fuzing or other components or properly made decision against detonation, the piezoelectric based power generation unit 100 will stop generating electrical energy once its initial vibratory motion at the time of impact has died out. The electrical power harvesting electronics and/or the fuzing electronics can utilize this event, if followed by target impact, to initiate detonation time-out circuitry. For example, the power source and/or fuzing electronics can be equipped with a time-out circuit that would disable the detonation circuitry and/or components to make it impossible for the round to be internally detonated. The time-out period can be programmed, for example, while loading fuzing information before firing, and/or may be provided by built-in leakage rate from capacitors assigned for this purpose.
Wake-Up Signal Detection and Detection Beacon Provision
[0051] Consider the situation in which a round has landed without detonation and its detonation window has timed-out. Then at some point in time, a recovery crew may want to attempt to safely recover the unexploded rounds. The present piezoelectric based power generation unit 100 can readily be used to transmit an RF or other similar beacon signals for the recovery crew to use to locate the projectile. This may, for example, be readily accomplished through the generation of acoustic signals that are produced by the dropping or hammering of weights on the ground or by detonating small charges in the suspect areas. The acoustic waves will then cause the piezoelectric elements of the power source to generate a small amount of power to initiate wake-up and transmission of the RF or similar beacon signal. The beacon signal/RF signal transmitter is considered to be part of the processor for purposes of simplicity, but can be separately provided.
[0052] When appropriate, the acoustic signal being transmitted by the recovery crew could be coded, such as with location information from a GPS receiver integral with the processor 208 . A GPS receiver can be integral with the processor (as shown) or separate therefrom. In addition, this feature of the power generation unit 100 provides the means for the implementation of a variety of tactical detonation scenarios. As an example, multiple rounds could be fired into an area without triggering detonation, awaiting a detonation signal from a later round, which is transmitted by a coded acoustic signal during its own detonation.
[0053] While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims. | A method is provided for recovering and/or exploded an unexploded munition. The method including: providing the munition with a power supply having a piezoelectric material for generating power from an induced vibration; inducing a vibration; monitoring an output from the power supply after the power supply has stopped generating power from a firing of the munition; and generating a beacon signal or detonation signal upon the detection of the output. | 3 |
BACKGROUND OF THE INVENTION
In machine shops there is often a need to perform secondary or auxiliary machining functions. Such functions as chamfering, slotting, milling of flats and removing protrusions and the like may be performed by most production machines. However, it is often time consuming and expensive to set up and run production machines to perform these secondary or auxiliary operations.
It is not uncommon practice to set up a machine to perform these secondary operations and employ an operator to do little else but perform these auxiliary functions.
OBJECTS
It is an object of this invention to provide a motor driven apparatus which will serve to perform a variety of secondary or auxiliary machining functions.
It is further an object of this invention to provide the apparatus as described above wherein the motor and apparatus assembly is light weight and portable.
It is further an object of this invention to provide the apparatus described above wherein the apparatus is configured so as to drive more than one cutting tool and to be set up to perform a multiplicity of different auxiliary machining operations at a multiplicity of work positioning and feeding locations on the apparatus.
DISCUSSION OF PRIOR ART
The prior art may be divided into two categories; special tools and guides to be attached to production machinery to facilitate the performing of auxiliary machining functions, and fixed location machines dedicated to the performing of special machining tasks.
The applicant knows of no portable motor driven apparatus which may be set up to perform a number of auxiliary machining operations using a number of cutters and tool positioning and guiding means to provide the apparatus with the capability of performing a number of auxiliary machining operations as needed.
BRIEF DESCRIPTION OF THE INVENTION
The invention is a portable apparatus for performing auxiliary machining operations comprising a base, an electric motor mounted on the base, an arbor projecting over the base mounted to the shaft of the motor, circular milling cutters mounted to the arbor, an ID or OD chamfering tool mounted to the end of the arbor, a housing having adjustable guides and stops located at an end, top and two lateral sides of the housing. The top guide being a V-guide for positioning pieces relative to the milling cutter for straight line chamfering, the end guide being a guide for ID and/or OD chamfering of round or tubular work pieces, the two side guides being emp1oyable for slotting, flat milling, protrusion removal and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of the apparatus of this invention.
FIG. 2 is a partially sectioned plan view of the device of this invention.
FIG. 3 is a sectional view of the straight line chamfering guide of this invention.
FIG. 4 is a sectioned partially schematic pictorial view of the first side guide configuration of this invention.
FIG. 5 is a schematic pictorial view of the second side guide configuration of this invention.
FIG. 6 is a sectioned elevational view of the end guide configuration of this invention.
DETAILED DESCRIPTION OF THE INVENTION
In the figures like numbers refer to like objects.
The invention is characterized by having a motor 1 mounted on a base 2, and having motor shaft 3 projecting over base 2. Attached to motor shaft 3 is arbor 4 having mounted to its midsection spaced apart circular milling cutters, first milling cutter 5 and second milling cutter 6, and having secured to its end ID-OD chamfering tool 7. Arbor 4 is supported at its midlength by support plate 8 which is mounted on guide plate 9 which is supported above and parallel to base plate 2 by first side plate 10 and second side plate 11.
An external housing, comprising side plates 10 and 11, end plate 12, and top 13 covers arbor 4. Incorporated with plates 10, 11, 12, and top 13 are first side guide 14, second side guide 15, end guide 16, and top guide 17, respectively. Guides 14, 15, 16 and 17 may be set up to perform a given function or set of functions to serve the needs of the user.
The above described apparatus is portable and incorporates its own motor. It has four guide positions by means of which the apparatus may be set up to perform four or more commonly needed auxiliary operations according to the needs of the user. In general the guide is sized according to the work piece, and positioned relative to the cutting tool. Adjustable stops are positioned as needed. The work piece is then inserted through the housing by way of the guides and brought into contact with the cutting tool which performs the desired operation.
The apparatus of this invention is described in a representative configuration below. It should be understood that the two side plates, the end plate and the top may be individually replaced so that a variety of guides and/or guide mounts may be incorporated into the housing as required. While the following disclosure is such that one skilled in the art could make and use the invention for its intended purposes without undue experimentation, the range of utility of the apparatus is to some extent dependent upon the imagination and skill of the user. An attempt to deal exhaustively with the possible combinations of guides, mounts, adjustments, and work piece holders would cause the specifications to become prolix and greatly multiply the claims. Therefore the following descriptions should be read to include obvious combinations and equivalents thereto which would become apparent to one skilled in the art.
Top guide 17 is a 90° V-guide which is positioned over milling cutter 5 as shown in FIGS. 1 and 3. A straight line work piece 18 may be passed through guide 17 and thereby have a straight line chamfer 19 cut on piece 18 by cutter 5. The size of chamfer 19 is adjusted by raising or lowering guide 17 relative to cutter 5 which is achieved by loosening bolts 20, raising or lowering adjustment screw 21 and retightening bolts 20.
End guide 16 is here shown to serve the utility of providing an ID or OD chamfer to round or tubular stock. Guide 16 as shown in FIGS. 1, 2, and 6 is positioned to guide a round work piece such as tube 22 into conventional adjustable ID-OD cutter 7. Cutter 7 has an outside cutter 23 for cutting outside chamfers to round stock and inside cutter 24 for providing inside chamfers to tubing stock. ID-OD chamfering tool 7 may be adjusted and sized to cut only ID chamfers, only OD chamfers, or alternatively ID and OD chamfers simultaneously. FIG. 6 serves to illustrate how a set screw 25 in end plate 12 and bearing against a flat 26 on guide bushing 27 serves to secure end guide 16 into plate 12. This and other similar means may be employed to change guide bushings to accommodate to various diameters and shapes of work pieces.
First side guide 14 and second side guide 15 are of similar construction. As shown in FIGS. 1, 2, 4, and 5, guides 14 and 15 are adjustable parallel to the axis of rotation of arbor 4 and are associated with adjustable stops for setting the depth of cut for pieces inserted through guides 14 and 15. Guide bushings 28 and 29 are secured in first slide plate 30 and second slide plate 31 respectively. Slide plates 30 and 31 are provided with slots 32 and locking screws 33. Slide plates 30 and 31 are threadably engaged by adjustment screws 34 which are fixedly attached to adjustment wheel 35. Slide plates 30 and 31 are provided with play spring 36 which is held in place by retainer screw 37.
In use, screws 33 are loosened, wheel 35 is rotated until the guide is in the proper location and screws 33 are tightened. Spring 36 serves to reduce play in the mechanism and thereby assure accuracy of positioning.
Side guides 14 and 15 are also associated with first piece stop 38 and second piece stop 39 respectively. Stops 38 and 39 serve to engage a work piece inserted through the guides and thereby limit the depth of cut on the work piece. Stops 38 and 39 are provided with slots 40 and locking screws 41, adjustment screw 42, and adjustment knob 43. In use locking screws 41 are loosened, knob 43 is rotated until the stop is in the desired location, and locking screws 41 are tightened.
Guide 15 is illustrated in FIGS. 2 and 5 as being positioned so that the centerline of the work piece will be guided into the center of cutter 5. This arrangement serves the utility of removing protrusions from the work piece or for slotting as illustrated. In use, guide 15 and stop 39 are first positioned, work piece 44 is inserted through guide bushing 29 and into cutter 5 until work piece 44 engages stop 39 at which time the cutting of slot 45 in work piece 44 is completed.
First side guide 14 is shown in FIGS. 1, 2, and 4 as being provided with a guide bushing 28 having radial indexing slots 46. Bushing 28 is associated with work piece holder 47. Piece holder 47 is provided with thumb screw 48 which serves to lock work piece 49 in holder 47. Locater pins 50 are positioned on holder 47 so as to act in cooperation with bushing 28 so as to index holder 47 to indexing slots 46 in guide bushing 28.
In use, in the mode illustrated, guide bushing 28 is positioned so as to guide the centerline of work piece 49 midway between cutters 5 and 6. Work piece 49 is secured in holder 47 and holder 47 is indexed to and inserted into guide bushing 28 and work piece 49 is advanced into cutters 5 and 6 until it contacts stop 38 at which time parallel flats have been cut on work piece 50. Holder 47 may then be withdrawn and reindexed 120° until the end of work piece 49 has been fashioned into a hexagonal cross sectional profile.
A preferred embodiment of the invention has been disclosed above. It should be understood, however, that the scope of the invention should not be limited to that of the disclosed embodiments but rather that the scope of the invention should be limited only by the scope of the appended claims and all equivalents thereto which would become apparent to one skilled in the art. | A motor driven apparatus for performing secondary or auxiliary functions such as cutting slots, chamfering, milling flats, removing protrusions and the like. The apparatus comprises a motor having a multiplicity of cutting tools mounted to the shaft, a box like housing covering the shaft and tools, guides incorporated into the construction of the top and three sides of the housing, and the guides serve to position and guide work pieces into the cutters to perform common auxiliary or secondary operations on work pieces. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to the estimation of path delays in a telecommunication network, in order to synchronize distributed clocks.
2. Description of the Prior Art
The Precision Time Protocol (PTP) is a standardized protocol used to synchronize clocks throughout a communication network. In 2008 a revised standard, IEEE 1588-2008, was released. This new version is also known as protocol PTPv2.
The operation of PTP relies on measurements of the communication path delay between a time source, referred to as a master, and a given time receiver, referred to as a slave. This process involves a message transaction between the master and the slave where the precise instants of transmission and reception are measured/captured—preferably at the hardware level. Messages containing captured time information could be adjusted to account for their path delay, therefore providing a more accurate representation of the time information conveyed.
The IEEE 1588-2008 standard describes hierarchical master-slave architecture for clock distribution. Under this architecture, a time distribution system consists of one or more communication media (network segments), and one or more clocks.
An ordinary clock is a device with a single PTP port and is either a source (master) or a destination (slave) of the synchronization distribution chain.
A boundary clock has multiple PTP ports and can accurately bridge synchronization network segments distributing the time reference from one network segment to another. A synchronization master is elected, as the relative time reference, for each of the network segments in the system. The absolute time reference is represented by the grandmaster. The grandmaster transmits synchronization information to clocks residing within its assign network domain/segment. Boundary clocks located on that network segment, recover the absolute time reference as accurately as possible, then distribute the recovered time reference to downstream network segments to which they are also connected.
The grandmaster clock represents the absolute time source. The grandmaster, the boundary clocks and the (ordinary) slave clocks are organized into a tree-like hierarchy with the grandmaster as the root of this hierarchy, the slave clocks as its leaves, and boundary clocks as intermediate elements. The grandmaster distributes the time reference towards the slave clocks across this tree-like hierarchy. The synchronization path between the grandmaster and a given slave clock can be decomposed as a succession of pairs of master and slave with the slave of the upstream segment becoming the master of the downstream segment. Between a given pair of the aforementioned master and slave are deployed transparent clocks.
IEEE 1588-2008 introduces a so called transparent clock associated with a network equipment used to convey PTP messages. A transparent clock modifies PTP message (headers) as these messages cross the network device. The transparent clock process consists in measuring the PTP message residence time within the network equipment and cumulate this measure in a field, located in the PTP message header, called the correctionField. This methodology improves the synchronization distribution accuracy by compensating for residence time variability across a network equipment.
There are two types of transparent clocks:
End-w-end transparent clocks measure and update the residence time for each synchronization packet (e.g. Synch message). Peer-to-peer transparent docks perform similar operations as the end-to-end transparent clock. In addition, they measure the link delay associated with the ingress transmission path (upstream communication path delineated by either a Peer to Peer transparent clock or a Master) and cumulate this delay in the correctionField as well.
PTP delay measurement process of the path between any given pair of master and slave essentially involves the precision timing of two messages: A Sync message and a delay_Req message. Half of the round-trip delay obtained by the exchange of these two messages provides an estimation of the one-way (in the master to slave communication direction) delay. Accordingly, the accuracy of such estimation is generally impacted by two types of noises:
The first one is the Packet Delay Variation (PDV) which represents the variability of delays undergone by different synchronization packets on a given synchronization path. This variability makes that the estimated path delay associated to a synchronization message is noisy due to the difference in time between the path delay estimation event and the actual message transmission event. The second type of noise is the delay asymmetry which represents the difference of path delays between one way of communication with regards to the opposite one. The slave time offset inaccuracy is theoretically equal to half of the delay asymmetry.
The PTPv2 protocol provides transparent clocks in order to address the aforementioned noises impacting the accuracy of the synchronization distribution.
Transparent clocks essentially measure synchronization message residence time within the associated network equipment. The measured residence times are cumulated in the correctionField located within the synchronization packet header. For stringent synchronization requirements, transparent clocks must perform all those operations very accurately and on the fly (at the PTPV2 message rate) without introducing additional delays.
Transparent clocks are generally deployed between a given pair of master and slave clocks in order to measure the synchronization message residence times across traversed network nodes. The sum of all measured residence times is taken off the end-to-end path delay by the slave (or the master). This makes nodes implementing transparent clocks “transparent” to the slave (or the master) in term of end-to-end path delay budget.
Within the IEEE 1588_2008 standard, the peer delay mechanism is also introduced for estimating delays of paths between adjacent transparent clocks, or between a transparent clock and the direct (i.e. adjacent) master or direct (i.e. adjacent) slave. Those measured path delays, as well as delay asymmetries, are cumulated within the Sync message correctionField by the peer-to-peer transparent clocks, so that the slave clock can be informed of them in addition to traversed network node residence times. With all this information, a slave can more precisely compute its offset with regards to the master clock time scale, as this computation is less noisy with regards to packet delay variation and delay asymmetry.
FIG. 1 illustrates the basic peer delay method in an exemplary part of a network comprising two IP routers IPRA and IPRB, each comprising a peer-to-peer (P2P) transparent clock (P2PTCA and P2PTCB) and at least two Precision Time Protocol (PTP) ports. For instance the IP router IPRA comprises two PTP ports PA1 and PA2; the IP router IPRB comprises two PTP ports PB1 and PB2. The PTP port PA1 of the router IPRA is directly linked (i.e. no intermediate network nodes) to the PTP port PB1 of the router IPRB.
The router IPRB sends a Pdelay_Req message to the router IPRA. The latter replies with a Pdelay_Resp message. The router IPRB then estimates the path delay induced by the link between the router IPRA and the router IPRB.
Later, the router IPRA receives a Synch message SYNC originating from a master clock and going at least to one slave clock, via the routers IPRA and IPRB. This message brings synchronization information to the slave.
With regards to FIG. 1 topology, there is no problem to associate the estimated path delay (or link delay) to the Sync message, because there is only one possible path. The peer-to-peer transparent clock PTPTCB of router IPRB updates the correctionField by taking into account the estimated path delay between the router IPRA and the router IPRB.
However, there are concerns within PTPv2 standard on the deployment of the peer delay mechanism, especially when peer delay entities are not directly linked, meaning that they are separated by at least one intermediate node (If the later is a network node that does not support PTPv2, or if it is a network node that comprises an end-to-end transparent clock);
For the rest of the description, we refer to this type of deployment as “non link-by-link” deployment of the peer delay mechanism.
It is noted that a peer-to-peer transparent clock and the associated network node perform very different specific operations. Thus, the peer-to-peer transparent clock only performs modifications over PTP message (headers) while the associated network is responsible for the encapsulation and the forwarding of the PTP messages.
For the rest of the document and for all the performed operations, the mention to the peer-to-peer transparent clock and the mention to the associated network node are interchangeable, as per the sake of simplicity.
Clause 11.4.4 of the IEEE 1588_2008 standard describes the peer delay mechanism concern as following:
“A delay requestor, Node-A, may receive 0, 1, or multiple Pdelay_Resp messages for each transmitted Pdelay_Req. Multiple responses can be detected by observing that the Source Port Identity fields of the Pdelay_Resp messages differ.
NOTE: Multiple responses can occur if there is an end-to-end transparent clock or an ordinary bridge or other similar multicast and multiport devices between Node-A and multiple Node-B devices. Although the multiple responses can be distinguished, there is no mechanism in this standard that allows the path length associated with each of the responses from the multiple Node-B devices to be correctly assigned to a received Sync message.”
As described by the aforementioned clause, the concern is that there is no mechanism defined within PTPv2 standard to allow the receiver of a Sync message to associate the right path delay to this message, amongst different measured path delays (i.e. estimated via the peer delay mechanism). This concern essentially focuses on the multicast scenario. However, the standard concern can be generalized to include the unicast scenario as well.
FIGS. 2, 3, 4 illustrate the issue with path delay association in an exemplary part of a network comprising three IP routers IPRA, IPRB, IPRC, and an intermediate router IPRI. Each IP router IPRA, IPRB, IPRC comprises each a peer-to-peer transparent clock, respectively P2P TC A, P2P TC B, P2P TC C. Each IP routers IPRA and IPRB comprises at least two PTP ports, especially with PTP port PA on P2P TC A and PB on P2P TC B, having respectively IP addresses @IP-A and @IP-B.
The router IPRC comprises three PTP ports and especially PC1, PC2, both corresponding to a same IP address @IP-C. It is noted here that PTPv2 standard does not forbid the implementation of several PTP ports over the same network interface or communication port.
The intermediate IP router IPRI comprises three communication ports (i.e. IP ports).
The PTP port PA of the router IPRA is directly linked to a first IP port of the intermediate router IPRI. The IP port associated to PTP port PB of the router IPRB is directly linked to a second IP port of the intermediate router IPRI. The IP port associated to PTP port PC of the router IPRC is directly linked to a third IP port of the intermediate router IPRI.
The peer-to-peer transparent clock P2P TC C of router IPRC has two peers, respectively the peer-to-peer transparent clock P2P T CA in router IPRA, and the peer-to-peer transparent clock P2P TC B in router IPRB. There is no PTP clock in the intermediate IP router IPRI. This router is called a non-PTP aware equipment.
FIG. 2 illustrates the issue with the path delay association in a unicast scenario, and a network topology where the intermediate router IPRI is a non-PTP aware network element because it does not comprise a transparent clock. The peer-to-peer mechanism is deployed to measure the path delay between pairs of adjacent peer-to-peer transparent clocks:
P2P TC A and P2P TC C for a first path. P2P TC B and P2P TC C for a second path.
The peer-to-peer transparent clocks P2P TC A and P2P TC B implement respectively two PTP ports corresponding to the addresses @IP-A and @IP-B. In this deployment of the peer delay mechanism, the peer-to-peer transparent clock P2P TC C implements two different PTP ports PC1 and PC2 over a same IP port corresponding to the address @IP-C. This is possible as not forbidden by the PTPv2 standard. Thus, the peer-to-peer transparent clock P2P TC C of router IPRC has the knowledge of two path delays, respectively the one between itself and peer-to-peer transparent clock P2P TC A and the one between itself and the peer-to-peer transparent clock P2P TC B.
Within the network topology and deployment as illustrated by FIG. 2 , the peer-to-peer transparent clock P2P TC C has an issue to identify the path followed by the Sync message at the reception of the later. Indeed, neither the source (PTP) port identity nor the source IP address of the Sync message allows the clock P2P TC C to know whether the message has transited via the clock P2P TC A or via the clock P2P TC B, as the aforementioned pieces of information are those related to the far end master clock (not represented in the FIG. 2 ).
It is noted that FIG. 2 illustrates a specific case with two PTP ports PC1 and PC2 implemented on a same IP port of the router IPRC, this IP port corresponding to the address @IP-C. This is only for the sake of description simplicity. However, the issue can be generalized to cases where each PTP port is associated to one transport protocol related port (e.g. IP port).
The issue cannot be resolved using only the PTPv2 protocol. Thus, the IEEE 1588_2008 standard presently provides with recommendations to restrict the use of peer delay mechanisms. This precludes, for instance, the deployment of a mix of end-to-end transparent clocks and peer-to-peer transparent clocks, or a mix of non-PTP aware network elements and peer-to-peer-transparent clocks, in order to optimize the deployment costs and also to relax deployment constraints.
FIG. 3 illustrates the issue with path delay association in another network topology that is restricted (or avoided) by the standard. The topology is the same as the one of FIG. 2 except that the intermediate router IPRI′ comprises an end-to-end transparent clock E2E TC I. The peer-to-peer transparent clock P2P TC C of the router IPRC implements two PTP ports PC1 and PC2 on a same IP port corresponding to the address @IP-C.
The peer-to-peer mechanism is deployed to measure path delays between pairs of adjacent peer-to-peer transparent clocks:
P2P TC A and P2P TC C for a first path. P2P TC B and P2P TC C for a second path.
This deployment is restricted (or avoided) by the standard as there is no means to associate to the Sync message the right path delay as explained above. The operator of the network should deploy in this case a link-by-link peer delay mechanism as illustrated by the FIG. 4 .
Stressing on the advantage of the invention, FIG. 4 illustrates the path delay association in a deployment that is allowed by the standard. The topology is the same as the one of FIG. 2 except that the intermediate router IPRI′ comprises a peer-to-peer transparent clock P2P TC I; and the peer-to-peer transparent clock P2P TC C of the router IPRC implements a single PTP port PC on an IP port corresponding to the address @IP-C.
In this deployment, the peer delay mechanism is deployed:
On the link between the peer-to-peer transparent clock P2P TC A of the router IPRA and the peer-to-peer transparent clock P2P TC I of the intermediate router IPRI′. On the link between the peer-to-peer transparent clock P2P TC B of the router IPRB and the peer-to-peer transparent clock P2P TC I of the intermediate router IPRI′. On the link between the peer-to-peer transparent clock P2P TC C of the router IPRC and the peer-to-peer transparent clock P2P TC I of the intermediate router IPRI′.
The later implementation is not cost effective especially when there is a mesh network, i. e. as per deployment of a great number of peer delay mechanisms, this number being equal to N×(N−1) where N is the number of network nodes.
Thus, there is a need to provide a more cost effective technical solution for supporting the peer delay mechanism.
This can be solved by applying the method according to the invention.
SUMMARY OF THE INVENTION
The object of the invention is a method for synchronizing distributed clocks by the Precision Time Protocol, in a telecommunication network, comprising the steps of:
sending a Sync message from one clock to another via a plurality of network nodes, a first of these nodes comprising a first peer-to-peer transparent clock and a second of these nodes comprising a second peer-to-peer transparent clock, estimating the path delay of the transmission path traveled by the synchronization message from the first to the second peer-to-peer transparent clocks, by:
sending a Pdelay_Req message from the second peer-to-peer transparent clock to the first peer-to-peer transparent clock, and sending a Pdelay_Resp message from the first peer-to-peer transparent clock to the second peer-to-peer transparent clock,
and then taking this path delay into account for updating the time information carried by a synchronization message, in the second peer-to-peer transparent clock;
characterized in that, for estimating said path delay it comprises the steps of:
using a tool, available in the transport protocol, for creating in network node associated to the first peer-to-peer transparent clock, a list of the network addresses of the network interfaces traversed by the synchronization message along its transmission path between the first and the second peer-to-peer transparent clocks; ordering the first list into the order in which the network interfaces have been traversed by the Sync message; creating a second list by reversing the order of the first list; communicating the second list to the second peer-to-peer transparent clock; and using the mechanism available in the transport protocol, in network nodes associated respectively to the first and the second peer-to-peer transparent clocks, to constrain the respective paths of Pdelay_Req and Pdelay_Resp messages so that their respective paths map to the second and first ordered lists of traversed interfaces.
Thanks to this method, the association of the right path delay to the Sync message travelling from a first to a second peer-to-peer transparent clock can be done without ambiguity even within a non link-by-link peer mechanism deployment. Thus, this method allows for the deployment of a mix of end-to-end transparent clocks and peer-to-peer transparent clocks, or a mix of non-PTP-aware network elements and peer-to-peer-transparent clocks, in order to optimize the deployment costs and also to relax deployment constraints.
Other features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to illustrate in detail features and advantages of embodiments of the present invention, the following description will be with reference to the accompanying drawings. If possible, like or similar reference numerals designate the same or similar components throughout the figures thereof and description, in which:
FIG. 1 , described above, illustrates the basic peer delay method.
FIG. 2 , described above, illustrates the issue with path delay association in a unicast scenario, and a network topology where the intermediate router IPRI is a non-PTP-aware network element.
FIG. 3 , described above, illustrates the issue with path delay association in another network topology that is restricted (or avoided) by the standard.
FIG. 4 , described above, illustrates the path delay association in a deployment that is allowed by the standard.
FIGS. 5 to 8 illustrate a first embodiment of the method according to the invention, in a homogeneous environment (e.g. IP only environment).
FIG. 9 illustrates a second embodiment of the method according to the invention, in a heterogeneous environment (e.g. IP and Ethernet).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 5 to 8 illustrate a first embodiment of the method according to the invention, in a homogeneous IP environment, e. g. Internet Protocol (IP). They represent an exemplary part of a network comprising three IP routers IPRA, IPRB, IPRC, and three intermediate IP routers IPRI1, IPRI2, IPRI3. The peer-to-peer transparent clock P2P TC C of router IPRC has two PTPv2 peers, respectively peer-to-peer transparent clock P2P TC A in router IPRA, and peer-to-peer transparent clock P2P TC B in router IPRB. There is no PTP clock in the intermediate IP routers IPRI1, IPRI2, IPRI3.
The clocks P2P TC A and P2P TC B respectively implement two PTP ports respectively corresponding to the IP addresses @IP-A and @IP-B. It is noted that the clock P2P TC C implements two different PTP ports over two different IP ports corresponding respectively to the IP addresses @IP-C1 and @IP-C2.
The intermediate IP router IPRI1 has:
a first IP port directly linked to the IP port of the router IPRA, corresponding to the IP address @IP-A; a second IP port directly linked to the IP port of the router IPRB, corresponding to the IP address @IP-B; a third IP port directly linked to a first port of the IP router IPRI2; a fourth IP port directly linked to a first port of the IP router IPRI3.
The IP router IPRI2 has a second IP port directly linked to the IP port of the router IPRC, corresponding to the IP address @IP-C1. The IP router IPRI3 has a second port directly linked to the IP port of the router IPRC, corresponding to the IP address @IP-C2.
FIG. 5 illustrates a more general issue with regards to the issue illustrated by FIG. 1 . It represents the same PTPv2 topology as the one represented by FIG. 1 but with a different network topology. This is a homogeneous environment as only IP encapsulation of PTPv2 messages is supported by all network nodes. For instance, a Synch message is forwarded from a master clock to the slave clock, via the routers IPRB, IPRI1, IPR3, IPRC.
With regards to FIG. 5 scenario, the peer-to-peer transparent clock P2P TC C has no path delay to associate to the received Sync message, even if it could have any means to identify the Sync path. This can be explained by the fact that the IP routing is generally based on the destination IP address. Since the destination IP address of the Sync message is the slave IP address, the routing of the Sync message does not necessarily follow the same network path as Pdelay_Resp messages which have either @IP-C1 or @IP-C2 as destination IP addresses.
In order to work around this issue, a first embodiment of the method according to the invention consists of the automatic procedures illustrated by FIGS. 6, 7 and 8 . This first embodiment comprises the following steps:
1) On FIG. 6 , the peer-to-peer transparent clock P2P TC B detects the communication path of the Sync message (i.e. from the peer-to-peer transparent clock P2P TC B towards the slave clock via the IP router IPRI1. Its associated network node, which is the router IPRB, uses the IP TRACEROUTE command with the IP destination address set to the IP address of the slave clock. An IP TRACEROUTE ECHO Request message is forwarded through the IP routers IPRI1, IPRI2, IPRC, and so on until reaching the slave.
The output of the IP TRACEROUTE command provides the peer-to-peer transparent clock P2P TC B with an ordered list of traversed interface IP addresses. In the present scenario, the interested portion of the list is (@IP-1, @IP-2, @IP-C1. It is noted that the peer-to-peer transparent clock P2P TC B has means for associating the IP port corresponding to the address @IP-C1 with the peer-to-peer transparent clock P2P TC C (e.g. by configuration).
2) On FIG. 7 , the peer-to-peer transparent clock P2P TC B builds the reverse ordered list (@IP-C1, @IP-2, @IP-1) and communicates this later to the peer-to-peer transparent clock P2P TC C, using a new Type Length Value (TLV) structure as defined by the protocol PTPv2. This PTPv2 structure is forwarded through the IP routers IPRI1, and IPRI3, for example.
This new structure of the TLV field is:
Bits
TLV
7
6
5
4
3
2
1
0
Octets
Offset
tlvType (to be assigned by IEEE to identify the TLV)
2
0
lengthField (length of the all the subsequent fields in
2
2
octets)
addressType (indicates the format of the addresses)
2
4
One or more Addresses (ordered list of addresses
M
6
with the first address at the top)
This TLV field can be carried within one of the first Pdelay_Resp messages transmitted by the peer-to-peer transparent clock P2P TC B to the peer-to-peer transparent clock P2P TC C.
Alternatively, the reverse ordered list TLV can be transported within a PTPv2 management message, transmitted by the peer-to-peer transparent clock P2P TC B to the peer-to-peer transparent clock P2P TC C.
3) On FIG. 8 , the peer-to-peer transparent clock P2P TC B uses the ordered list of interface IP addresses and the peer-to-peer transparent clock P2P TC C uses the reverse ordered list in order to constrain respectively the Pdelay_Resp and the Pdelay_Req message paths so that they are transmitted on the same path experienced by the Sync message, meaning via the IP routers IPRI1 and IPR2. Within this method, only the path delay associated to the path traversed by the Sync message is measured. Thus, the peer delay mechanism can only apply on this particular path.
Within a pure IP environment, a method to constrain network path can consist in using source routing mechanism (Cf. IETF RFC 791).
Within an IP/MPLS environment, the path constraining method can consist in using the RSVP-TE (Resource ReserVation Protocol-Traffic Engineering) EXPLICIT ROUTE OBJECT (Cf. IETF RFC 3209).
FIG. 9 illustrates a second embodiment of the method according to the invention, in a heterogeneous environment. It is the same issue as the one of FIG. 5 , but within a heterogeneous environment. We consider an exemplary part of a network comprising three successive domains D1, D2 and D3:
The first domain D1 and the third domain D3 are IP-based technology (e.g. PTP is encapsulated over UDP over IP—IEEE Standard 1588-2008 Annex D or Annex E). They are separated by the second domain which is Ethernet-based technology (i.e. IEEE Standard 1588-2008 Annex F is deployed). Alternatively, the second domain could implement MPLS-TP. The first domain D1 is an IP or IP/MPLS (Multiprotocol Label Switching) environment. It includes two IP routers IPRA′ and IPRB′. The later play the role of border network nodes separating the first domain D1 from the second domain D2. Those routers respectively comprise peer-to-peer transparent clocks P2PTCA′ and P2PTCB′. They are connected to the second domain D2 thanks to a communication port. The communication port of the first router has the IP address IP-A and the MAC (Medium Access Control) address MAC-A. The communication port of the second router has the IP address IP-B and the MAC address MAC-B. The second domain D2 is an Ethernet environment, meaning that the IEEE Standard 1588-2008 Annex F is implemented, eventually jointly with the IEEE 802.1q or the IEEE 802.1ah. or alternatively with MPLS-TP (Multiprotocol Label Switching-Transport Profile). In any case, D2 includes three Ethernet switches ESI1, ESI2, ESI3. Those switches are non-PTP aware equipments. The third domain D3 is an IP or IP/MPLS environment. It includes the IP router IPRC′. The later plays the role of the border node separating the third domain D3 from the second domain D2. The IP router IPRC′ comprises a peer-to-peer transparent clock P2P TC C′ that implements two PTP ports over two respective communication ports in the D2 domain. The first communication port has the IP address IP-C1 and the MAC address MAC-C1. The second communication port has the IP address IP-C2 and the MAC address MAC-C2.
The Ethernet switch ESI1 has:
a first port directly linked to the Ethernet port of the router IPRA′, corresponding to the MAC address MAC-A; a second port directly linked to the Ethernet port of the router IPRB′, corresponding to the MAC address MAC-B; a third port directly linked to a first port of the Ethernet switch ESI2; a fourth port directly linked to a first port of the Ethernet switch ESI3.
The Ethernet switch ESI2 has a second port directly linked to the Ethernet port of the router IPRC′, corresponding to the MAC address MAC-C1. The Ethernet switch ESI3 has a second port directly linked to the Ethernet port of the router IPRC, corresponding to the MAC address MAC-C2.
The peer-to-peer transparent clock P2P TC C of router IPRC has two peers, respectively peer-to-peer transparent clock P2P TC A′ in router IPRA′, and peer-to-peer transparent clock P2P TC B′ in router B′. There is no PTP clock implemented on the Ethernet switches ESI1, ESI2, ESI3. The later are non-PTP aware nodes.
For instance, a Sync message SYNC is forwarded from a master to a slave, through the router IPRB′, the Ethernet switches ESI1 and ESI2, and the IP router IPRC′.
Within this heterogeneous environment, the peer-to-peer transparent clocks P2P TC A′, P2P TC B′, P2P TC C′ are border nodes between technology domains:
at one side, they use a PTP message encapsulation method over IP (e.g. the Sync message is encapsulated over UDP over IP—IEEE standard 1588_2008 Annex D or Annex E); at the other side, they use a PTP message encapsulation method that is Ethernet (e.g. the Pdelay_Req/Pdelay_Resp messages are encapsulated over Ethernet—IEEE standard 1588_2008 Annex F).
Thus, the peer-to-peer transparent clocks can deal with two different encapsulation technologies and can perform the interworking between these later. It is noted that the Sync message traversed the Ethernet-based domain transparently.
This second embodiment of the method according to the invention comprises the following steps:
1) The peer-to-peer transparent clock P2P TC B′, which detects the transmission direction of the Sync message (i.e. from the transparent clock P2P TC B′ towards the slave clock), monitor its IP destination address (which is the slave IP address) and particularly its next hop IP address which is IP-C1 (e.g. lookup in the IP routing table)
2) The peer-to-peer transparent clock P2P TC B′ obtains the MAC address MAC-C1 associated to the IP address IP-C1 using for instance the Address Resolution Protocol called as ARP (IETF RFC 826). This could also be obtained via some pre-configurations.
3) The peer-to-peer transparent clock P2P TC B′ uses the Ethernet OAM TRACEROUTE command with the MAC destination address set to MAC-C1.
The output of the Ethernet OAM TRACEROUTE command provides the peer-to-peer transparent clock P2P TC B′ with an ordered list of interface MAC addresses, corresponding to the interfaces traversed by the Synch message SYNC within the second domain D2
4) The peer-to-peer transparent clock P2P TC B′ builds a second list by reversing the first list, and communicates this second list to the peer-to-peer transparent clock P2P TC C′, by using a new TLV structure (i.e. now the addressType should indicate MAC address and not IP addresses). Again, this new TLV field can be transported within one of the first Pdelay_Resp messages transmitted by the peer-to-peer transparent clock P2P TC B′ to the peer-to-peer transparent clock P2P TC C′. Alternatively, the reverse ordered list can be transported within a PTPv2 management message transmitted by the peer-to-peer transparent clock P2P TC B′ to the peer-to-peer transparent clock P2P TC C′.
5) The peer-to-peer transparent clock P2P TC B′ uses the ordered list of interface MAC addresses, and the peer-to-peer transparent clock P2P TC C′ uses the reverse ordered list, in order to constrain respectively the Pdelay_Resp and the Pdelay_Req message paths.
A method to constrain the communication path within an Ethernet environment could consist in using virtual local area networks (VLAN) IEEE 802.1q or IEEE 802.1ah. Alternatively, MPLS-TP (MPLS Transport Profile) can be used for signaling of the path, using RSVP-TE and EXPLICIT ROUTE OBJECT.
The main difference with respect to the previous described homogeneous environment is that the peer-to-peer transparent clocks here estimate the path delay, of the Sync message transported over UDP over IP (e.g. IEEE standard 1588 annex D), by using PTP messages (i.e. Pdelay_Req/Pdelay_resp) encapsulated over Ethernet data packets (e.g. IEEE standard 1588_2008 annex F).
Traditionally, it is recommended to implement Boundary Clocks at the border of different encapsulation technology domains. But thanks to the present invention, the peer-to-peer transparent clocks can be seamlessly supported, with a relative reduction in complexity. Thus the invention solves the restrictions related to the deployment of peer delay mechanism. It allows for inserting non-PTP aware nodes and/or end-to-end transparent clocks amongst peer-to-peer transparent clocks, making the deployment more flexible.
Also, thanks to the reduction of the peer delay instances, it allows for reducing the number of peer delay messages, reducing network resource consumption, especially within a mesh large-scaled network.
Finally, as illustrated by the second embodiment (i.e. heterogeneous environment), the method according to the invention allows for avoiding boundary clocks at technology domain border. This may significantly reduce the complexity of the synchronization architecture.
The method according to the invention can be implemented over any other kind of packet-based network.
The method according to the invention can be implemented by agents, each agent being a processor-executable program performing the method when the program is run on a processor. An example of implementation is described in the document EP 2.408.128.
One or more agent is implemented in each network node equipped with a PTP clock such as an ordinary clock, a boundary clock or a transparent clock. These agents allow for providing an interworking between different network entities and a PTP clock within a given network node.
Indeed, the interworking agent can be seen as an extension of the PTP protocol stack and typically cannot be installed without PTP module. An interworking agent has two types of interfaces:
a PTP-side interface to interact with PTP entities at an application level, and at least one network-side interface to interact with network entities (an operations, administration and maintenance (OAM) plane or a control plane) at a network level.
Thus, the interworking agent can communicate on the one hand with the PTP clock and on the other hand with network entities. Therefore it is an interface between both sides/levels that enables to inform of events occurred at one level to the other one such as a failure event at one level requiring a reconfiguration or a modification of some parameters at the other level. | The method includes sending a Sync message from a first peer-to-peer transparent clock to a second peer-to-peer transparent clock, estimating the path delay of the transmission path traveled by the synchronization message from the first to the second peer-to-peer transparent clocks, and taking this path delay into account for updating the time information carried by a synchronization message. The estimating includes creating a list of the network addresses of the network interfaces traversed by the synchronization message; ordering the first list into the order in which the network interfaces have been traversed by the Sync message; creating a second list by reversing the order of the first list; communicating the second list to the second peer-to-peer transparent clock; and using the mechanism available at the transport protocol level, to constrain the respective paths of Pdelay_Req and Pdelay_Resp messages so that their respective paths map to the second and first ordered lists of traversed interfaces. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to tufting machines and more particularly to a tufting machine wherein the needles are carried by needle holders which are selectively latched to a reciprocating latch bar, the needle holders being mounted between guide plates adjustably mounted in the machine.
Tufting machines which produce carpet, basically include a large frame having a head within which a rotatable mainshaft is mounted and from which needle driving structure is supported for reciprocating a multiplicity of needles. The frame also includes a bed within which oscillating loopers or hooks are mounted for cooperating with the needles to form loops of yarn, knives being used in conjunction with the hooks to cut the loops in many tufting machines. As the tufting art has developed, there have been a substantial number of innovations to obtain unique patterning effects. One such innovation has been to shift the needles laterally in accordance with a pattern. Another innovation has been to provide each needle with a sew/no-sew capability by mounting the needles on individual needle holders which are reciprocated selectively by either being latched to or disengaged from a reciprocating latch bar, the latter being reciprocably driven continuously from mechanism driven by the rotating mainshaft. When latched to the latch bar, the needle reciprocates into cooperation with the hook to form a loop. The latching occurs by means of latch pins on pneumatic cylinders driven in accordance with a pattern. Machines of this type are known as controlled needle machines, and when each needle is individually controlled in this manner, it is known as an individual controlled needle machine.
A recent development in the tufting art is to combine the individual control needle machine concept with the shifting needle concept, and to feed the backing material intermittently. This provides a tufting machine wherein the needles may be threaded with a number of different yarns, e.g., yarns of different colors, and a needle having a yarn of a particular color may be inserted into the backing at any of a selected number of locations so that extremely precise multi-color patterns may be produced similar to the fine woven carpets produced by looms. A machine of this type is illustrated in Bardsley U. S. Pat. No. 5,653,184.
In such tufting machines, as illustrated in the aforesaid patent, the needles are individually mounted in an elongated holder, one end of which is adapted for latching to the latch bar and the other end of which mounts the needle. The needle holder is normally biased by a return spring into a non-sewing position and is driven into a sewing position during sewing against the bias of the spring by the needle drive arrangement. The needle holder includes a spring biased ratchet-like clamp arrangement which causes the yarn to be drawn from the supply when the needle holder moves from the non-sewing position to the sewing position by trapping the yarn between the clamp and a wall of the holder. When the needle holder moves back to the non-sewing position, the tension on the yarn urges the clamp away from the wall of the holder so that the yarn can pass through the clamp.
A problem that has arisen with this construction of the prior art is that the ratchet-type clamp of the needle holder is in a position whereby access to the spring for removal or replacement is difficult. In a majority of cases if these parts fail or need replacement, it has been necessary immediately to replace the entire needle holder, thereby increasing cost of replacement parts and machine down-time. The spring in the prior art is within the body of the needle holder or within an extension secured to the needle holder, the extension having a deep slot milled between two thin wall portions. Pins within the slot must be positioned so as to guide yarn and hold the ratchet-type mechanism and spring within the slot. A coil spring having two legs one of which is disposed about the pin on which the clamp is journalled and the other of which is disposed about another pin so as to bias the clamp against the yarn is disposed within the slot. The slot within the needle holder is milled so as to leave a little material at the end to permit a hole to be formed for mounting the pin about which the spring is curled.
Moreover, the needle holder on such machine is mounted for movement by means of a pair of ridged guide blocks or plates having parallel channels therein. The guide bars or plates are secured to a top and bottom surface of a needle support bar and the ridges or channels in the guide plates define therebetween positions in which respective needle holders can be mounted. A corresponding ridged pair of fixing plates are secured to a top and bottom surface of a fixing bar and can be secured in a position relative to the guide plates so that the needle holders are secured in position in a tufting machine intermediate respective ridges formed in the guide plates and fixing plates. Each of the fixing and guide plates is adjustable relative to the needle support bar and/or fixing bar in order to allow the needle holder to be adjusted to ensure accurate alignment with the drive mechanism. The drive plates and fixing plates may be modular in so far as they have a width such that each plate retains only a small number of needle holders in position in the machine.
The arrangement of the mounting blocks in the prior art is such that the needle holders cannot be removed readily from the tufting machine in a direction transverse to the direction of reciprocation, and thus in order to remove the needle holder it is presently required to penetrate the backing material, cut an opening and remove the needle holder in the vertical or reciprocation direction.
A problem arises with this existing mounting system since the correct alignment of the needle holder and the drive mechanism are dependent upon the relative positioning of at least four plates, thereby making it difficult and time consuming to achieve such correct alignment.
Additionally, thermal expansion may cause the guide plates and/or the needle holder to vary in shape or dimension. If the needle holder has a straight or dovetail cross sectional configuration as in the prior art, such expansion may result in the needle holder becoming misaligned by twisting or rotating slightly in the guide. The thermal expansion resulting in such variation may be caused by frictional heating of the guide plate and/or the fixing plate during operation.
SUMMARY OF THE INVENTION
Consequently, it is a primary object of the present invention to provide an improved needle mounting system and needle holder for a tufting machine having needle holders which may be individually latched to a reciprocating drive bar selectively.
It is another object of the present invention to provide a needle mounting system for a tufting machine having needles mounted individually in needle holders reciprocable between guide members and which may be selectively latched to a reciprocating drive bar, the needle mounting system permitting adjustments of the guide plates to allow correct positions and alignment to ensure accurate reciprocation of the needles.
It is a further object of the present invention to provide an improved needle holder for a tufting machine having needles which have sew/no-sew capability in which the yarn drawing ratchet clamp is biased by a spring mounted externally of and readily removeably attached to the needle holder.
It is a further object of the present invention to provider a needle mounting system for a tufting machine having needles which may be latched to or unlatched from a reciprocating drive bar, needle holder guide elements and needle holders having cooperating arcuate surfaces to prevent twisting of the needle holders in the guides due to thermal expansion or the like.
It is a yet still further object of the present invention to provide a needle mounting system including guide plates between which needle holders may reciprocate, the guide plates having guide elements which may be adjustable to ensure correct alignment and which is constructed to permit the guide elements to be released so that the needle holder may be removed from a tufting machine transversely of the direction of reciprocation thereof.
Accordingly, the present invention provides an improved mounting for a needle in a controlled needle or sew/no-sew tufting machine, the mounting including a holder from which a needle depends at one end, and the second end of the holder being adapted for driving connection to a reciprocating drive of the tufting machine. A ratchet type clamp which is normally biased by a spring into a position in which yarn may be drawn from a supply during a movement of the needle holder as it moves to the sewing position into a fabric to cooperate with a hook and is prevented from moving as the needle holder and needle move away from the fabric and the hook on which the yarn has been seized is provided with a biasing spring mounted externally of and removeably attached to the holder. This construction makes it possible to provide a mounting for a needle in a controlled needle machine in which parts thereof which are prone to mechanical breakage may be removed and replaced without the necessity to replace the entire needle holder.
The needle mounting system includes a guide plate mounted on or adjacent a needle support bar of the tufting machine and a fixing plate is removeably secured relative to the guide plate to secure at least one needle holder in position between the fixing plate and the guide plate. The needle holder is drivingly linked to a drive mechanism which is operable to selectively reciprocate the needle for sewing. The guide plate and fixing plate respectively comprise a pair of guide or fixing elements connected so as to be adjustable as to position relative to the drive mechanism thereby to ensure correct alignment relative to the drive mechanism whereby the needle holder is driven in an accurate path and the needle may cooperate with the respective hook. This arrangement allows simple adjustment of the guide plate relative to the drive mechanism for the needle holders to provide accurate alignment of the holder with the drive mechanism and thereby ensure accurate driving of the needle holders during operation of the tufting machine.
Preferably the guide and fixing elements are ridged so as to define a plurality of channels therebetween in which the needle holders can be mounted, the channels being substantially curved in cross section and the front and back edges of the needle holder are also substantially curved. Thus, the needle holder during sewing is less prone to jamming than in the prior art, and furthermore, less frictional heat is generated which may cause distortion of the guide and/or fixing plate which itself would tend to increase the likelihood of jamming. Preferably, the front and back edges of the needle holder in cross section and the channels in the guide and fixing plate have a configuration which is a portion of a circle, i.e., an arcuate shape with a fixed radius.
BRIEF DESCRIPTION OF THE DRAWINGS
The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a fragmentary side elevational view of a tufting machine incorporating the needle holder and holder mounting arrangement constructed in accordance with the principles of the present invention;
FIG. 2 is a side elevational view of a needle holder illustrated in FIG. 1 greatly enlarged in relation thereto;
FIG. 3 is a cross sectional view taken substantially along line 3--3 of FIG. 1; and
FIG. 4 is an elevational view depicting a guide plate illustrated in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, FIG. 1 illustrates a tufting machine 10 incorporating apparatus constructed in accordance with the principles of the present invention. The machine includes a laterally elongated head 12 within which a plurality of longitudinally spaced push rods (not illustrated) are mounted for reciprocation. The push rods are reciprocably driven by drive mechanism in the head 12 substantially identical to that disclosed in U.S. Pat. No. 4,860,674. The lower end of the push rods are connected to the rods of linear bearings 14, only one of which is illustrated, the housing of the bearings being secured to a latch bar 16 which thus reciprocates with the push rods and may move transversely relative thereto. Alternatively, the push rods may be connected to push rod feet to which the linear bearings are connected. In either case, the latch bar may be reciprocated and shifted transversely. The latch bar has a multiplicity of air cylinders 18 with cylinder actuated latch pins 20 that may be selectively extended from or retracted into the latch bar in accordance with a pattern as disclosed in Bardsley U.S. Pat. No. 4,790,252 in a manner well-known in the art.
The tufting machine incorporates a separately controlled latch pin 20 corresponding to each tufting needle 22 in the machine, and is thus known as an individually controlled needle tufting machine. Each needle is mounted within and extends from a separate needle holder 24 to which further reference will be had. The latch bar is secured to a moveable arm 26 having a linear bearing 28 at an end remote from the latch bar 16 and is moveable vertically about a support strut or rod 30. The cylinder 18 is pneumatically operated to extend and retract the latch pin 20. When the latch pin is extended it may engage the needle holder 24 to allow selective driving of the needle holder. To facilitate this, the needle holder includes a notch 32, best illustrated in FIG. 2, into which the pin of a respective cylinder may selectively engage to drive the needle holder. When the needle holder is driven downwardly, the needle penetrates a backing material F to cooperate with a hook 34 located in the bed 36 of the tufting machine as is conventional to form tufts in the backing material fed over a bedplate 38.
A spring 40 is connected between the needle holder 24 and a vertically fixed member of the machine so that movement of the needle holder 24 downwardly during reciprocation by the drive mechanism is biased by the spring 40 and the needle holder is normally returned to a starting position by a tab 42 on the latch bar for engaging a lug 44 secured to and extending out of the needle holder 24 at the top thereof, and the spring acts to urge the needle holder upwardly against an abutment member 46 on a frame member to which the upper end of the spring is secured.
The needle holder 24 comprises an elongated one-piece metallic member and the needle 22 may be either releasably secured in position by means of a releasable screw (not illustrated) as is conventional, or alternatively the needle can be bonded to the holder using any suitable bonding material which would secure the needle in the holder and be releasable if necessary for replacement. The needle holder 24 has substantially curved front and rear edges 48, 50 for reasons hereinafter made clear, and is mounted between a guide plate 52 and a fixing plate 54 and may be reciprocated vertically as guided by these plates. The guide plate 52 is mounted to a needle support bar 56 which is attached by an arm 57 to the housing of a linear bearing 58, the rod of the bearing being fixedly attached to the head 12 of the machine by means of a linkage member 60 which may have a curved configuration as illustrated or may be of any other suitable shape. The linear bearing permits the needle support bar 56 and thus the guide plate 52 to slide transversely, the linear bearing housing also supporting the strut 30 so when the latch bar 16 is shifted transversely so to do other elements such as the needle support bar, the guide plate and the needle holder. The fixing plate 54 is releasably secured to a fastening bracket 62 which is connected by a rail 63 and clamp arm 65 to linear bearings 64, 66 slidable within a housing so that the fixing plate 54 also moves as a unit with the guide plate 54 and the needle holder 24.
The guide plate 52 and fixing plate 54 are substantially identical and as illustrated in FIGS. 3 and 4 have removable guide insert elements 68 provided at each end thereof. The guide elements 68 have a plurality of substantially parallel, substantially uniformly spaced ridges 70 therein which define a plurality of substantially parallel, substantially uniform spaced channels therebetween. The ridges 70 in the inserts 68 are curvilinear in cross section with a fixed radius, and so to are the front and back edges 48, 50 of the needle holder 24. The removable insert elements 68 are formed from a plastic material having high temperature stability, low friction characteristics such as polyether-ether ketone with carbon fiber and PTFE fillers, the hardness being sufficient so as not to be subject to excessive wear during use. Preferably, the guide and fixing plates 52, 54 are of such size as to secure between approximately 10 to 12 needle holders in position, each guide plate 52 being of the same dimension and associated with one fixing plate.
The curved edges of the needle holder and the ridges 70 of the inserts locates the needle holder 24 in the channels while allowing a small variation in relative position of the guide plates and fixing plates 52, 54 from an ideal or absolute alignment without jamming. This variation may be due to thermal expansion caused by frictional heating of the guide and/or fixing plates during sewing or tufting. The shape is particularly advantageous since when the edges are located in the ridges of the channels, the edges of the needle holder 24 are permitted to roll slightly within the channel about the longitudinal axis of the holder. This allows a small variation and position of the guide and fixing plates 52, 54 without increasing the degree of friction during movement of the holder while the machine is sewing or tufting, i.e., a small amount of angular movement of the needle holder 24 may occur relative to the guide and fixing plates without significantly increasing the likelihood of locking or jamming during reciprocation. This renders the needle mounting system of the present invention easier to set up in a more accurate manner than the prior art since a small amount of movement of the fixing plate 54 in a direction transversely of the ridges is possible relative to the guide plate 52 with minimal effect on needle position, accuracy of driving the needle holder and no significant increase in friction.
The fixing plate 54 is releasably secured in position relative to the guide plate 56 by way of a fastener member 72 which includes one or more spherical washers 74 which allow the releasable connection of the plate to the bracket not withstanding small angular inclinations between the fastener member and the fastening bracket 62. This arrangement means that, after the guide plate 56 has been fixed in position relative to the drive mechanism for the needle holder 24, the fixing plate 54 is capable of being fixed in a suitable position relative to the guide plate 52 to secure the needle holders 24 in place not withstanding that the fixing plate may have to be positioned at a small angle relative to the fastening bracket 62. Therefore, this arrangement obviates the need for absolute accuracy in the relative positions of the needle support bar 56 and the rail 63 to which the fastening bracket 62 is secured when assembling the tufting machine while allowing the needle holder 24 to be accurately aligned with the drive mechanism for accurate reciprocation of the needle. Furthermore, and significantly, this arrangement also facilitates ease of removal of the needle holder 24 from the machine for replacement. This ability arises due to the fact that the fixing plate 54 is removable completely and therefore both inserts 68 are released from contact with the needle holder 24 to enable the needle holder to be removed from the tufting machine transversely of the direction of reciprocation easily without the necessity for the needle holder to penetrate the backing fabric as in prior art constructions. In the prior art, for example, if a needle holder is to be removed, a hole must be made in the backing fabric and the needle holder dropped through the backing.
At the lower end of the needle holder 24, adjacent the needle 22, the present invention provides a ratchet clamp arrangement comprising a pivoted ratchet clamping member 78 which is biased by a spring clip 80 in the form of a leaf spring into a position in which yarn is trapped between a nose or leading edge 82 of the clamp and a side wall 84 formed in the needle holder by a spark eroding process. Thus, an opening 86 is provided in the needle holder adjacent the lower end thereof to form a recess 85 within the body of the needle holder. Thus, during the downward movement of the needle holder 24 from an upper position to the sewing position, yam is pulled from the supply by the needle as the nose 82 of the clamp 78 traps the yam within the holder against the wall 84. On the upward movement of the needle holder the yam extending from the supply to the hook 34 is held by the hook so that the yarn urges the clamp 78 against the bias of the spring 80 and permits the clamp to ride over the yarn. The yarn is guided about a small pin 88, and the clamp 78 is pivoted by a stepped rivet or the like 90
The spring clip 80 is a flat metallic member and has a substantially U-shaped configuration in elevation with an outwardly extending bend on the leg 79 acting against the clamp 78, the leg 79 of the spring extending into the recess 85 through the opening 86 which, it may be noted, extends from an arcuate portion down toward the bottom of the needle holder so that the leg 79 of the spring may enter to act against the clamp. The spring or clip 80 has the leg 81 opposite to the leg 79 secured by a fixing screw 92 to a nub 94 at the bottom of the needle holder spaced from the location in which the needle is disposed. This enables the spring clip 80 to be replaced, if necessary, merely by removal of the fixing screw 92.
In use, the needle mounting system is assembled on a tufting machine 10 after the drive mechanism including the latch bar 16 have been mounted. The needle holders 24 are then offered up to the guide plate 52 and are positioned between the ridges 70 formed in the inserts 68, rear edges 50 of the needle holders abutting the inserts in the plate 52. The fixing plate 54 is then removably secured in a position relative to the guide plate 52 to secure the needle holders 24 in position between the guide plate and the fixing plate, in the channels formed between the respective ridges 70 in the elements 68 of the two plates 52, 54. In order to ensure that the drive mechanism and the guide plate 52 are correctly aligned to ensure accurate drive of the needle holders during reciprocation, the position of the guide plate and hence the needle holders is capable of adjustment by movement of a mounting plate 96 relative to the top housing of the head 12, the mounting plate being secured to the linkage 60. Accordingly, the mounting plate 96 and/or the top housing head are provided with apertures (not illustrated) including one of which is elongated so that the mounting plate may be adjustably fastened using a removable fastener which extends through the apertures. Adjustment of the mounting plate 96 relative to the top housing of the head is possible by releasing the fastener and moving the mounting plate relative to the housing, the extent of movement permitted being determined by the dimensions of the elongated slot. Once in the desired position, the fastener may be again tightened. It will be appreciated that since only one guide plate 52 is utilized with a pair of separate ridged guide elements 68, both of the guide elements are removable together and movement of one relative to the other is not permitted. This makes it a much simpler task to accurately align the guide plate 52 with the drive mechanism and ensures to maintain the guide plate in the correct position when aligned. Thus, if the guide plate is accurately aligned with the drive mechanism and is thus releasably secured in position, it acts effectively as a datum for the needle holders 24. Once the correct alignment of the guide plate 52 and the drive mechanism has been achieved, the mounting plate 96 is releasably secured to the top housing of the head maintaining the guide plate in the desired position. The fact that with the present invention adjustment of the position of the guide plate 52 and the driving mechanism is permitted when the machine is set up for operation, or subsequently, provides considerable advantages, particularly as the guide elements 68 are removable together. Firstly, the correct alignment ensures accurate reciprocation of the needle holder 24 between the plates 52, 54 and reduces the likelihood of jamming or locking. Furthermore, the fact that the needle holders 24 are correctly driven aligned with the drive mechanism also reduces the frictional heating of the needle holders which reduces the likelihood of jamming or locking caused by thermal expansion of the various parts. Moreover, since both the guide plate and the fixing plate are modular, it is only necessary to ensure accurate alignment between a small number of needle holders and the latch pin 20 of the drive mechanism.
It will be appreciated that with the present invention, by rendering the most likely parts to fail by wear, or otherwise require replacement, accessible for replacement, it is possible to significantly reduce machine down time and the cost of replacement parts and labor. Additionally, certain of the misalignment problems that may occur in the prior art are alleviated.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modification which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. | An individually controlled needle tufting machine has a reciprocable latch bar for latching and unlatching selective needle holders, each needle holder being guided between a pair of guide plates and carrying a respective needle so that each needle selectively may be driven by the latch bar. The guide plates each include a plurality of curvilinear ridges and the edges of the needle holder are curvilinear and are received within a respective spaced apart pair of ridges within which they are guided as the needle holder reciprocates. The plates include vertically spaced apart inserts within which the ridges are formed. The needle holder has a yarn clamp mounted internally adjacent the bottom and a leaf spring has a leg mounted externally of the holder and has a leg entering internally to act upon and urge the yarn clamp. | 3 |
RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 09/426,626, filed Oct. 26, 1999, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a floating receiving mechanism for a paddle handle actuated latching mechanism and to a handle assembly including such a mechanism. More particularly, the present invention relates to use of a floating mechanism that provides self-alignment with a latch assembly, suitable for use on an item such as a truck box.
BACKGROUND OF THE INVENTION
Boxes and containers designed to fit securely within the bed of a pick-up truck have become increasingly popular. Such boxes are extensively used by tradesmen and contractors who require a secure storage compartment for holding tools and equipment and require a secure lockable container for their equipment.
Different lid arrangements are known in the art including wing-style lids which open along each side of the box as well as a single hinged lid which opens along a length of the box.
One such locking lid arrangement can be found in U.S. Pat. No. 5,226,302 to Anderson assigned to Loctec Corporation which is incorporated herein by reference. This reference provides a latch mechanism in which a notched plunger is mounted from an overhead lid of the truck box. As the plunger is inserted into an opening of the latch assembly, the plunger self-adjusts for proper alignment and results in a lock self-adjustable in six directions.
U.S. Pat. No. 5,941,104 to Sadler, which is incorporated herein by reference, is directed toward a paddle lock which provides a latching mechanism which latches and unlatches upon a striker element and is actuated by movement of the handle member.
While the examples discussed above provide useful latching mechanisms, there remains room for variation and improvement within the art.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a receiving mechanism for a handle assembly having a self-adjusting feature to facilitate the alignment and engagement of the handle assembly within the receiving mechanism.
According to one aspect of the invention, a floating receiving mechanism is disclosed for use with a handle assembly including a base plate defining a central opening and at least two side openings therethrough. The side openings are located on opposite sides of the central opening. A keeper defines a central opening therethrough. The keeper is attached to the base plate via connection members extending from the keeper through the side openings so that the keeper central opening is substantially aligned with the base plate central opening. Each connection member is sized so as to be slidable laterally in a respective side opening to thereby allow the keeper to move laterally relative to the base plate. The keeper is configured for releasably retaining an extending portion of the handle assembly.
If desired, the keeper may be substantially U-shaped, or may have a base portion and two arms extending from the base portion, the central opening being defined in the base portion. Each of the arms may terminate in a lip.
Also, the extending portion of the handle assembly may be a rotatable member, the rotatable member being insertable into the keeper in any position of rotation and being withdrawable from the keeper stud in at least one unlocked position of rotation. The rotatable member may thus be operatively connected to the handle assembly, and the rotatable member may be a keeper stud having a first terminus defining at least one notch, the notch engaging the keeper when the keeper stud is in a locked position of rotation and disengaging the keeper when the keeper stud is in the unlocked position of rotation. The keeper stud may include a plurality of the notches arranged in at least one pair. The base plate may be secured to a lid of a container and the handle assembly may be secured to the container.
According to another aspect of the invention, a floating receiving mechanism is disclosed for use with a handle assembly including a base member defining a central opening therethrough. A substantially U-shaped keeper has a base portion defining a central opening therethrough and two arms extending from the base portion. The keeper is attached to the base member so that the keeper central opening is substantially aligned with the base member central opening and so that the keeper is slidable laterally relative to the base member. The keeper is configured for releasably retaining an extending portion of the handle assembly.
A means may be provided for slidably connecting the base member and the keeper. The means for slidably connecting may include connection members slidable in openings, and the openings may be slots located in the base member.
According to another aspect of the invention, a handle latch assembly is disclosed including a handle assembly including a rotatable member actuatable by a handle. The handle assembly is mountable on a first surface and has an extending portion. A receiving mechanism is provided for releaseably securing the extending portion. The receiving mechanism is mountable on a second surface movable relative to the first surface. The receiving mechanism includes a base member defining a central opening therethrough. A substantially U-shaped keeper is provided having a base portion defining a central opening therethrough and two arms extending from the base portion. The keeper is attached to the base member so that the keeper central opening is substantially aligned with the base member central opening and so that the keeper is slidable laterally relative to the base member. The keeper is configured for releasably retaining an extending portion of the handle assembly.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings.
FIG. 1 is a perspective view of the present invention utilized as a latching mechanism for a truck box carried within the bed of a truck;
FIG. 2 is an elevated perspective view of an embodiment of the latch mechanism in relation to a truck cargo box;
FIG. 3 is an elevated perspective view of an alternative cargo box arrangement utilizing a latching mechanism of the present invention;
FIG. 4 is an operational front perspective view of the latch assembly useful in the cargo box seen in FIG. 3;
FIG. 5 is a front perspective view of the latch assembly illustrating the keeper stud secured in a locked position of the receiving mechanism;
FIG. 6 is an elevated rear perspective view of latch assembly illustrating the rotating keeper stud in relation to an optional linkage rod in communication with the operating member;
FIG. 7 is a back view of the latch assembly illustrating the latching mechanism in a locked position;
FIG. 8 is a top perspective view, similar to FIG. 6, showing the relative movement of a locking cam member and the operating member with the engaging portion of the keeper stud removed for purposes of clarity;
FIG. 9A is a bottom perspective view of the latch assembly as seen in FIG. 6;
FIG. 9B is a bottom perspective view, similar to FIG. 9A, showing the handle member, actuating member, and operating member in open and unlocked configuration;
FIG. 9C is a view similar to FIG. 9B showing the handle member, actuating member, and operating member in a fully engaged and unlocked position; and
FIG. 10 is a plan view of a front face of the receiving mechanism of the latch assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in, or are obvious from, the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
The latch assembly according to the invention is illustrated in the figures generally as element 20 . FIGS. 1 and 2 illustrate one embodiment of latch assembly 20 as a latch or lock element for a hinged lid cargo box 10 . FIG. 3 further illustrates latch assembly 20 in an alternative embodiment as a tandem latching assembly for two separate hinged lids 12 A and 12 B. FIGS. 1-3 are only meant to illustrate a few of the possible environments of the invention. For example, the individual handle trays could be placed on the sides of the box if desired, which may be preferred in a box such as in FIG. 3 . It should be understood that the latch assembly, according to the invention, can be used in any number of environments, including panel doors of a utility truck, recreational vehicle, or any manner of commercial vehicles, lock boxes, marine applications, etc.
Referring to the figures in general, latch assembly 20 includes a housing or tray generally 22 . Tray 22 has a front side 24 and a back side 26 . Tray 22 may also serve as part of the means for mounting the latch assembly on a vehicle and in this regard may define a flange 28 around the circumference thereof. Flange 28 may define a plurality of mounting apertures 29 and, in one mounting configuration, would circumscribe an opening defined in the cargo box or other housing in which the latch assembly is mounted. It should, however, be understood and appreciated that the flange 30 is not a critical feature of the invention, and merely provides one means for mounting the latch assembly. Any manner of conventional devices as may be used and known within the prior art to mount a latch assembly may be employed, such as adhesives, separate mounting brackets, and other conventional mounting devices and means.
As seen in FIG. 5, handle assembly 20 also includes a handle member 40 , seen here as a paddle handle. However, handle 40 may take the form of any number of desired configurations. Handle 40 is mounted on the front side 24 of tray 22 so that it can be pulled outward, as particularly seen in FIGS. 9B and 9C. In a preferred embodiment, handle 40 is pivotally mounted by way of axle 42 to tray 22 . Tray 22 further defines side wall members 25 which define a cavity 27 . This arrangement positions the front surface of handle member 40 substantially flush within cavity 27 as particularly seen in FIG. 5 .
The back side 26 of tray 22 has a mounting bracket 30 attached. As seen in reference to FIGS. 6 and 7, mounting bracket 30 defines a flat plate 34 which is attached with rivets 32 to tray back side 26 . A support arm 36 extends substantially perpendicular away from the flat plate 34 and back side 26 of tray 22 . As best described below, mounting bracket 30 is used to support and position additional components of the latch assembly.
Referring particularly to FIGS. 7 and 9 A- 9 C, an actuating member 50 is operatively connected to handle member 40 to pivot therewith. Actuating member 50 is mounted on a portion of axle 42 that extends through side wall 25 of tray 22 . Thus, actuating member 50 is rotatable with handle 40 to actuate the mechanism on the back side 26 of tray 22 . As seen in the figures, actuating member 50 may comprise a piece of flat metal having a leading edge 52 which may comprise an arcuate or otherwise curved edge, the actuating member being used to actuate further elements of the latch assembly.
Edge 52 of actuating member 50 engages an operating member 60 mounted for pivotal or rotational movement on back side 26 of tray 22 . In the embodiment illustrated, operating member 60 is mounted so as to engage and rotate a base 72 of keeper stud 70 . As seen in FIGS. 7, 9 A, and 9 C, base 72 of keeper stud 70 traverses an aperture defined by support arm 36 , this arrangement maintaining keeper stud 70 substantially parallel to the plane of the flat tray back side 26 . The operating member 60 defines a collar 64 through which keeper stud base 72 passes, collar 64 gripping an outer perimeter of the base 72 . Operating member 60 further defines a pin 62 which is positioned opposite the arcuate edge 52 of actuating member 50 . As best seen in reference to FIG. 9A, edge 52 defines a convex surface. As seen in reference to the sequential positions seen in FIGS. 9A-9C, a shoulder region 54 initially engages the cam 62 of operating member 60 . As actuating member 50 is pivoted, shoulder 54 continues to engage cam 62 as the actuating member 50 pivots operating member 60 . As seen in the intermediate position of FIG. 9B, shoulder 54 and cam 62 continue to make contact along a substantial travel distance of the actuating member 50 and operating member 60 . As the engagement continues (FIG. 9 C), the peak and far shoulder of edge 52 engage cam 62 and fully extend the operating member. Accordingly, operating member 60 is movable by the engagement of the edge 52 relative to pin 62 allowing movement between a locked position (FIG. 9 A), an intermediate position (FIG. 9B) and an unlocked position (FIG. 9 C). When so engaged, the displacement of operating member 60 by edge 52 rotates collar 64 which, in turn, rotates base 72 and keeper stud 70 .
A coil spring 44 is used to provide a tensioned return mechanism for the latch assembly upon the release of handle 40 . Spring 44 is wrapped around base 72 with one end of spring 44 engaging a projection 38 (FIG. 9A) of support arm 36 , a second end of spring 44 in communication with operating member 60 . In the illustrated embodiments, the coil spring 44 acts upon operating member 60 to urge operating member and the interlinked components toward an initial configuration.
A distal end 74 of keeper stud 70 is defined partially by a plurality of notches 75 (defining teeth therebetween) on opposing side walls. As best seen in reference to FIGS. 5-7, distal end 74 further defines a pair of opposing smooth surfaced beveled walls 76 positioned at an approximate right angle to the opposing side walls defining notches 75 . A cylindrical midsegment 78 of keeper stud 70 interconnects the distal end 74 with the base 72 . The notches 75 and beveled walls 76 of keeper stud 70 will operatively engage a receiving mechanism 80 as best seen in reference to FIGS. 5, 7 , and 10 . Receiving mechanism 80 provides a face plate (or base plate) 82 such as a surface of a support bracket or other housing. Plate 82 defines an opening 84 in communication with an adjacent aligned keeper 86 having an opening 85 aligned with opening 84 . Keeper 86 is slidably movable by movement of connection members such as bolts 87 or rivets within a pair of attachment slots 89 defined by face plate 82 , the slots allowing movement of keeper 86 as indicated by directional arrow in FIG. 10 .
As seen in reference to FIG. 4, keeper stud 70 may engage receiving mechanism 80 so as the notches 75 of the distal end sidewalls engage a corresponding edge of the spaced apart tensioned lips 88 thereby providing a locked orientation. In this position, the lips clasp the notched side wall regions, the interengagement of lips 88 and notches 75 preventing the withdrawal of the keeper stud from the receiving mechanism 80 .
To provide an unlocked keeper stud position, an operator would engage handle 40 , pivoting the handle approximately 45 degrees. Movement of the handle in turn pivots actuating member 50 causing edge 52 to rotate operating member 60 . The rotation of member 60 causes collar 64 to simultaneously rotate keeper stud 70 by the engagement of base 72 . Ideally, in the illustrated embodiments, it is useful to rotate the keeper stud 70 approximately 90 degrees about its longitudinal axis, thereby positioning the smooth beveled edges 76 opposite the engaging lips 88 . In this unlocked position, the relative movement between the beveled edges 76 and the opposing tensioned lips 88 is facilitated. Further, the distance between the notched walls 75 is greater than the distance between the smooth surfaced walls 76 . As a result, the keeper stud may have the receiving mechanism more easily withdrawn when the smooth surface, thinner profile of walls 76 are positioned between the engaging edges of lips 88 . Accordingly, a lid of a lock box carrying the receiving mechanism 80 can be opened by the withdrawal of the receiving mechanism 80 from the keeper stud.
Keeper stud base 72 may also be used to engage a receiving aperture 102 (FIG. 6) defined by a linkage rod cam 100 . The linkage rod cam 100 and keeper stud base 72 are coupled together for integrated movement. In this manner, a linking rod 110 can connect via a turnbuckle 120 to a similar rod cam 100 of a second interlinked latch adjacent a first latch assembly (FIG. 4 ). This coupled, tandem arrangement enables simultaneous operation and control of both latch assemblies by the engagement of a single handle.
The coordinated movement of the latch assembly set forth here makes use of a keeper stud base 72 which is in coupled linkage with linkage rod cam 100 and operating member 60 . As a result, keeper stud 70 , linkage rod cam 100 and operating member 60 are interconnected so as to provide for integrated movement. Or, as stated another way, when any element of keeper stud 70 , operating member 60 , or linkage rod cam 100 is prevented from movement, none of the integrated individual parts will operate and paddle handle 40 will not pivot.
As a result, a variety of locking mechanisms may be used to limit the rotational movement of the integrated, coupled parts. One such mechanism can be provided by a key-operated lock mechanism 90 of conventional design such as a keyed cylinder which may be used to vary a position of a leg member 92 between a locked and an unlocked position. As seen in FIG. 7, leg member 92 may be used to block movement of linkage rod cam 100 thereby preventing the movement of keeper stud 70 . As a result, the keeper stud 70 is maintained in a locked position relative to the receiver mechanism 80 . It is apparent by those skilled in the art, that when two or more latch assemblies are interconnected by a common linking rod 110 , or individual linking rods 110 connected by a turnbuckle 120 (FIG. 4 ), any single lock assembly which is maintained in a locked position will prevent the normal operation of both latch assemblies 20 . In other words, locking any one of the latch assemblies will prevent the engagement of handle 40 and the subsequent engagement of actuating member 50 , operating member 60 , keeper stud 70 , and linkage rod cam 100 of all interlinked latch assemblies 20 . Thus, if desired, a lock assembly need only be provided on one of the two connected latch assemblies to achieve locking of both latch assemblies.
The present invention provides a novel latching mechanism which utilizes a notched keeper stud which is operatively connected to the handle and rotates in response to the engagement of the handle. The rotation allows the notched surfaces to disengage from a retaining edge disposed within a receiving element. As a result, the pivoting motion of the handle is translated into a rotational movement of the cylindrical keeper stud.
The use of a curved, convex surface to engage the operating member allows a greater movement of the operating member, without substantial increase in force required on the handle by the user, than would be achieved by a flat edge engaging surface. This arrangement allows a relatively short pivot motion of the handle to effect a proportionally increased distance of travel of the operating member. As a result, a ⅛ turn of the handle pivot results in a full ¼ turn of the stud keeper.
Further, the latch assembly provides a smooth fluid operation in which the initial pivoting motion of the handle achieves the greatest movement of the operating member, and hence, the keeper stud as well. In this manner, the initial movement of the handle where the user has the greatest leverage coincides where the greatest frictional force is need to overcome the positioning of the notched, wide edges of the keeper stud from engagement with the securing edges of the receiving mechanism. Also, the line of force at the point of contact between curved edge 52 and operating member changes as the handle is pulled, and the change serves to move the line of force to a more efficient orientation. That is, as the handle is pulled, the line of force approximates more closely a line tangent to a circle defined by the rotation of pin 62 around keeper stud 70 .
It is envisioned that either the receiving mechanism or the keeper stud may be provided with a compression spring, a pneumatic lift or similar device as well known in the art to facilitate the automatic release of the receiving mechanism from the keeper stud when the keeper stud is rotated into a disengaged position.
Although preferred embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the following claims. In addition, it should be understood that aspects of the various embodiments may be interchanged, both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein. | A floating receiving mechanism is disclosed for use with a handle assembly including a base member defining a central opening therethrough, and a substantially U-shaped keeper having a base portion defining a central opening therethrough and two arms extending from the base portion. The keeper is attached to the base plate so that the keeper central opening is substantially aligned with the base plate central opening and so that the keeper is slidable laterally relative to the base plate. The keeper is configured for releasably retaining an extending portion of the handle assembly. The extending portion may be a member such as a keeper stud. Other receiving mechanisms and related handle latch assemblies are also disclosed. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mobile communication system, in particular, to a CODEC system for use with a base-station controlling unit.
2. Description of the Related Art
FIG. 5 shows a digital mobile communication system according to a first example of the prior art. Here, when a mobile terminal 1 a calls a mobile terminal 1 b , a CODEC 41 a of a base-station controlling unit 3 a code-converts audio data of the mobile terminal 1 a through a base station 2 a into PCM audio data regardless of the attributes of, audio data of the mobile terminal 1 a and the mobile terminal 1 b . The base-station controlling unit 3 a transmits the PCM audio data to a mobile-terminal switching station 5 . The mobile-terminal switching station 5 transmits the PCM audio data received from the base-station controlling unit 3 a to a base-station controlling unit 3 b that accommodates the mobile terminal 1 b on the called side. A CODEC 41 b of the base-station controlling unit 3 b code-converts the PCM audio data received from the mobile-terminal switching station 5 into the audio data with the attributes of the mobile terminal 1 b . The base-station controlling unit 3 b transmits the resultant audio data to the mobile terminal 1 b through a base station 2 b.
In this first related art reference, regardless of the attributes of audio data of the mobile terminal 1 a on the calling side and the attributes of audio data of the mobile terminal 1 b on the called side, the base-station controlling unit 3 a on the calling side and the base-station controlling unit 3 b on the called side perform a code-converting process one time each (a total of two times).
Next, a second related art reference will be described. In the second related art reference, assuming that a mobile terminal transmits non-audio data such as FAX data to a terminal of the telephone network or another mobile terminal, a code-converting (CODEC) process is performed. When a mobile terminal transmits FAX data to a remote terminal, the mobile terminal on the calling side sets the communication mode to a FAX mode. However, at this point, the mobile terminal on the calling side determines whether the current mode thereof is an audio (telephone) mode or a non-audio (FAX) mode and notifies a relevant base station of the determined mode to the determined result. When the base station has received the notification that communication data is nonaudio data from the mobile terminal, the base station connects the communication data to a non-audio interface other than the audio CODEC interface so as to accomplish a non-audio communication with the terminal on the called side.
In other words, an object of the second related art reference is to simplify hardware of a base station in such a manner that a mobile terminal determines whether or not the current mode is audio data mode or non-audio data mode.
Next, the problems of the above-described related art references will be described.
In the first related art reference, when the attributes of audio data of the mobile terminal 1 a on the calling side are the same as the attributes of audio data of the mobile terminal 1 b on the called side, the base-station controlling unit 3 a on the calling side code-converts audio data (with the attributes common in the mobile terminal 1 a and the mobile terminal 1 b ) into PCM audio data. The base-station controlling unit 3 b on the called side code-converts the PCM audio data code-converted by the base-station controlling unit 3 a on the calling side into original audio data (with the attributes common in the mobile terminal la and the mobile terminal 1 b ).
Thus, although the attributes of audio data of the mobile terminal 1 a on the calling side are the same as the attributes of audio data of the mobile terminal 1 b on the called side, since the code-converting process is performed twice, the delay time of is audio data becomes large. In addition, the quality of audio data deteriorates.
The second related art reference is limited to non-audio (FAX) data communications. Further,
In the second related art reference, since a mobile terminal requires a data type determining circuit that determines whether data transmitted therefrom is audio data or non-audio data and a circuit that notifies a base station of the determined result, the additional circuitry increases the size of the mobile terminal.
SUMMARY OF THE INVENTION
An object of the present invention is to decrease the delay time of audio data being communicated between the mobile terminal 1 a on the calling side and the mobile terminal 1 b on the called side, to prevent the quality of audio data from deteriorating, and to accomplish such effects in a simpler call connecting sequence than before when the attributes of audio data of the mobile terminal 1 a on the calling side are the same as the attributes of audio data of the mobile terminal 1 b on the called side.
Another object of the present invention is to accomplish a simple method for monitoring audio data of two parties that are communicating with each other.
The present invention is a mobile communication system having a mobile-terminal switching station, a base-station controlling unit on the calling side, a base-station controlling unit on the called side, a base station, and mobile terminals, wherein the mobile-terminal switching station has a means for identifying attributes of audio data transmitted by the mobile terminal on the calling side and attributes of audio data of the mobile terminal on the called side, in the case and for prohibiting the base-station controlling unit on the calling side from transmitting a code-converting audio data when the attributes of the audio data of both mobile terminals are the same wherein the base-station controlling unit on the calling side has a means for selecting a first path of over which audio data received from the base station is output to the mobile-terminal switching station through a code-converting process or a second path of over which audio data received from the base station is output to the mobile-terminal switching station without a code-converting process, and a means for adding audio attribute information to audio data received from the base station, and wherein the base-station controlling unit on the called side has a means for identifying the audio attribute information added to the audio data received from the mobile-terminal switching station, and a means for selecting a first path over which audio data is output to the base station through a code-converting process or a second path over which audio data is output to the base station without code-converting process corresponding to the identified results.
The mobile terminal on called side has a means for identifying attributes of audio data of the mobile terminal on calling side and attributes of audio data of the mobile terminal on called side, and a means for prohibiting the base-station controlling unit on calling side from transmitting the code-converted audio data in the case that the attributes of the audio data of the mobile terminal on calling side match the attributes of the audio data of the mobile terminal on called side.
The base-station controlling unit on calling side has a means for prohibiting the base-station controlling unit on called side from transmitting the code-converted for audio data in the case that the attributes of the audio data of the mobile terminal on calling side match the attributes of the audio data of the mobile terminal on called side.
An audio monitor unit for monitoring audio data is connected to the mobile-terminal switching station, wherein the audio monitor unit has a means for identifying audio attribute information added by the base-station controlling unit to audio data being communicated between the mobile terminal on calling side and the mobile terminal on called side, and a means for determining whether or not the code-converting process for the audio data is required corresponding to the identified results, and wherein the audio monitor unit monitors audio data of the mobile terminal on calling side and audio data of the mobile terminal on called side, the mobile terminal on calling side and the mobile terminal on called side communicating in a CODEC-through manner.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram showing the structure of a CODEC-through system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram showing a first example of a call connecting sequence according to the present invention;
FIG. 3 is a schematic diagram showing a second example of the call connecting sequence according to the present invention;
FIG. 4 is a schematic diagram showing a third example of the call connecting sequence according to the present invention; and
FIG. 5 is a block diagram showing the structure of a related art reference.
DESCRIPTION OF PREFERRED EMBODIMENTS
Next, with reference to FIGS. 1 and 2, an embodiment of the present invention will be described. FIG. 1 is a block diagram showing the structure of an embodiment of the present invention. As shown in FIG. 1, a CODEC-through system according to the embodiment comprises mobile terminals 1 a and 1 b , base stations 2 a and 2 b , base-station controlling units 3 a and 3 b , and a mobile-terminal switching station 5 .
The base-station controlling units 3 a and 3 b each comprise an upbound signal processing portion 31 a , a downbound signal processing portion 31 b , and call connection controlling portions 42 a and 42 b . The upbound signal processing portion 31 a comprises a CODEC 41 a , an audio type information adding portion 61 a , and an audio data selecting portion 62 a . The downbound signal processing portion 31 b comprises a CODEC 41 b , an audio data type determining portion 61 b , and an audio data selecting portion 62 b . An audio data monitoring unit 8 comprises a CODEC 9 a , an audio data type determining portion 9 b , an audio data selecting portion 9 c , an adding portion 9 d , and an audio data outputting portion 9 e.
The CODECs 41 b and 9 a code-convert audio data into PCM audio data or vice versa corresponding to VSELP, QCELP, or PSI-CELP system.
Next, the operation of the CODEC-through system according to the embodiment will be described. When the mobile terminal 1 a calls the mobile terminal 1 b , the mobile-terminal switching station 5 performs a call connection controlling process therebetween. In other words, the mobile-terminal switching station 5 determines the attributes of audio data of the mobile terminals 1 a and 1 b . When the attributes of audio data of the mobile terminal 1 a match the attributes of audio data of the mobile terminal 1 b , the mobile-terminal switching station 5 issues a command for prohibiting to transmission of code-converted the audio data to the base-station controlling unit 3 a that accommodates the mobile terminal 1 a on the calling side.
In the case of a TDMA communication system, audio data of a mobile terminal is transmitted corresponding to VSELP or PSI-CELP system. In the case of a CDMA communication system, audio data of a mobile terminal is transmitted corresponding to QCELP system.
Next, the operation of the base-station controlling unit 3 a on the calling side will be described. The command issued by the mobile-terminal switching station 5 is transmitted to the call connection controlling portion 42 a of the base-station controlling unit 3 a . When the call connection controlling portion 42 a has received the command from the mobile-terminal switching station 5 , the call connection controlling portion 42 a notifies the audio data type information adding portion (hereinafter referred to as adding portion) 61 a of the fact that the attributes of audio data of the mobile terminal 1 a on the calling side match the attributes of audio data of the mobile terminal 1 b on the called side and of the attributes thereof. In addition, the call connection controlling portion 42 a notifies the audio data selecting portion 62 a of the fact that the attributes of audio data of the mobile terminal 1 a on the calling side match the attributes of audio data of the mobile terminal 1 b on the called side. When the adding portion 61 a has received the notification from the call connection controlling portion 42 a , the adding portion 61 a adds audio attribute information notified by the call connection controlling portion 42 a to audio data received from the base stations 2 a and outputs the resultant data to the audio data selecting portion 62 a.
Next, the operation of the upbound signal processing portion 31 a of the base-station controlling unit 3 a will be described. Audio data corresponding to VSELP or PSI-CELP system received from the base station 2 a is sent to both the CODEC 4 ′ a and the adding portion 61 a of the upbound signal processing portion 31 a . The CODEC 41 a code-converts audio data received from the base station 2 into PCM audio data regardless of the attributes of the audio data received therefrom and outputs the PCM audio data to the audio data selecting portion 62 a . When the adding portion 61 a has received the notification that the attributes the audio data of the mobile termipal 1 a on the calling side match the attributes of audio data the mobile terminal 1 b on the called side, the adding portion 61 a adds audio attribute information (of three bits) to the audio data received from the base station 2 a . However, the adding portion 61 a does not code-convert the audio data.
When the adding portion 61 a has not received the notification from the call connection controlling portion 42 a , the adding portion 61 a directly outputs the audio data received from the base station 2 a to the audio data selecting portion 62 a . When the audio data selecting portion 62 has received the notification that the attributes of audio data of the mobile terminal 1 a on the calling side match the attributes of audio data of the audio terminal 1 b on the called side from the call connection controlling portion 42 a , the audio data selecting portion 62 selects the audio data to which the audio attribute information has been added to the audio data received from the base station 2 a (namely, the audio data that has not been code-converted by the CODEC 41 a ). Thereafter, the audio data selecting portion 62 outputs the selected audio data to the mobile-terminal switching station 5 . When the audio data selecting portion 62 a has not received the notification from the call connection controlling portion 42 a , the audio data selecting portion 62 a selects the audio data that has been code-converted into PCM audio data by the CODEC 41 a and outputs the PCM audio data to the mobile-terminal switching station 5 .
Next, the operation of the base-station controlling unit 3 b on the called side will be described. Audio data received from the mobile-terminal switching station 5 is sent to both the CODEC 41 b and the audio data type determining portion 61 b of the downbound signal processing portion 31 b . The CODEC 41 b code-converts audio data received from the mobile-terminal switching station 5 into audio data with the attributes common to all mobile terminals 1 b on the called side.
The audio data type determining portion 61 b determines whether or not audio attribute information has been added to audio data received from the base-station controlling unit 3 a through the mobile-terminal switching station 5 . When audio attribute information has been added to audio data, the audio data type determining portion 61 b causes the audio data selecting portion 62 b to select audio data that has not been code-converted by the CODEC 41 b and to output the selected audio data to the base station 2 b . When audio attribute information has not been added to audio data, the audio data type determining portion 61 b causes the audio data selecting portion 62 b to select audio data that has been code-converted by the CODEC 41 b and to output the selected audio data to the base station 2 b.
Next, with reference to FIG. 2, a first example of the call connecting sequence of the CODEC-through system according to the embodiment of the present invention will be described. When the mobile terminal 1 a calls the mobile terminal 1 b , the mobile terminal 1 a transmits a call connection request (SET UP) to the mobile-terminal switching station 5 through the base station 2 a and the base-station controlling unit 3 a . When the mobile-terminal switching station 5 has received the call connection request (SET UP), the mobile-terminal switching station 5 transmits a call (PAG REQUEST) to a plurality of base-station controlling units. Thus, the mobile-terminal switching station 5 also transmits the call (PAG REQUEST) to the base-station controlling unit 3 b . The mobile terminal 1 b that has received a call (PAG MESSAGE) from the mobile-terminal switching station 5 sends back a response (AUTH RES) to the mobile-terminal switching station 5 .
In the process, the mobile-terminal switching station 5 identifies the attributes of audio data of the mobile terminal 1 a corresponding to CODEC INF included in the call connection request (SET UP). In addition, the mobile-terminal switching station 5 identifies the attributes of audio data of the mobile terminal 1 b corresponding to CODEC INF included in the response (AUTH RES) received from the mobile terminal 1 b through the base-station controlling unit 3 b . When the attributes of audio data of the mobile terminal 1 a match the attributes of audio data of the mobile terminal 1 b , after the mobile-terminal switching station 5 performs a certificating process and a channel-allocating process, the mobile-terminal switching station 5 transmits a response (ALERT) to the base-station controlling.unit 3 a and thqn a command (CODEC REQ) for prohibiting transmission code-converted audio to the base-station controlling unit 3 a.
When the base-station controlling unit 3 a has received the command (CODEC REQ), the base-station controlling unit 3 a sends back a response (CODEC RES) that represents an acknowledgment of the command (CODEC REQ) to the mobile-terminal switching station 5 . After the mobile-terminal switching station 5 has received the response command (CODEC RES), the mobile-terminal switching station 5 performs the conventional call connecting process so that the mobile terminals 1 a and 1 b communicate with each other. After both the mobile terminals 1 a and 1 b have communicated with each other, the base-station controlling unit 3 a on the calling side adds audio attribute information to audio data that has not been code-converted in the process shown in FIG. 1 and outputs the resultant audio data to the mobile-terminal switching station 5 .
The base-station controlling unit 3 b on the called side identifies audio attribute information (that has been added to audio data being communicated) by the base-station controlling unit 3 a on the calling side. Thereafter, in the process shown in FIG. 1, the base-station controlling unit 3 b on the called side autonomously selects audio data that has not been code-converted and outputs the selected audio data to the base station 2 b . After the call connecting process is completed and a communication is started, the base-station controlling unit 3 a adds audio attribute information to the audio data that is being communicated. In addition, the base-station controlling unit 3 b always identifies the audio attribute information. Thus, a communication can be made without the code-converting process.
Next, with reference to FIGS. 1 and 3, a second example of the call connecting sequence of the CODEC-through system according to the embodiment of the present invention will be described. In the first example, which the mobile-terminal switching station 5 prohibits the base-station controlling unit 3 a on the calling side from transmitting the code-.
In the second example, with reference to FIG. 3, the base-station controlling unit 3 b on the called side prohibits the base-station controlling unit 3 a on the calling side When the mobile terminal 1 a calls the mobile terminal 1 b , the mobile-terminal switching station 5 adds CODEC INF included in the call connection request (SET UP) to the command (PAG REQUEST) that is transmitted to each base-station controlling unit.
The call connection controlling portion 42 b of the base-station controlling unit 3 b of a plurality of base-station controlling units identifies the attributes of audio data of the mobile terminal 1 a corresponding to the CODEC INF included in the command (PAG REQUEST). In addition, the call connection controlling portion 42 b identifies the attributes of audio data of the mobile terminal 1 b corresponding to CODEC INF included in the response (AUTH RES) received from the mobile terminal 1 b through the base-station controlling unit 3 b.
When the attributes of audio data of the mobile terminal 1 a match the attributes of audio data of the mobile terminal 1 b , after the call connection controlling portion 42 b performs a certificating process and a channel-allocating process, the call connection controlling portion 42 b issues a command (CODEC REQ) for prohibiting transmission of code-converted voice signal to the base-station controlling unit 3 a on the calling side through the mobile-terminal switching station 5 . The connection controlling portion 42 a of the base-station controlling unit 3 a receives the command (CODEC REQ).
When the call connection controlling portion 42 a has received the command (CODEC,REQ), the call connection controlling portion 42 a transmits a response (CODEC RES) to the command (CODEC REQ) to the base-station controlling unit 3 b on the called side through the mobile-terminal switching station 5 . Thereafter, the call connection controlling portion 42 a causes the adding portion 62 a to add audio attribute information to the audio data. In addition, the call connection controlling portion 42 a causes the audio data selecting portion 62 a to select audio data that has not been code-converted by the CODEC 41 a and to output the selected audio data.
When the call connection controlling portion 42 b has received the response (CODEC RES), the call connection controlling portion 42 b causes the audio data selecting portion 62 b to select audio data that has not been code-converted by the CODEC 41 b and to output the selected audio data. After the call connecting process is completed and a communication is started, the base-station controlling unit 3 a adds audio attribute information to audio data being communicated. In addition, the base-station controlling unit 3 b always identifies the audio attribute information. Thus, a communication can be made without the code-converting process.
Next, with reference to FIGS. 1 and 4, a third example of the call connecting sequence of the CODEC-through system according to the embodiment will be described. In the second example, the base-station controlling unit 3 b on the called side identifies audio attribute information added to audio data being communicated and thereby autonomously determines whether or not the code-converting process is required without need for intervention by the mobile-terminal switching station 5 and the base-station controlling unit 3 a.
In the third example, the base-station controlling unit 3 b on the called side determines whether or not the code-converting process is required corresponding to a command received from the base-station controlling unit 3 a in the call connection process. The mobile-terminal switching station 5 identifies the attributes of audio data of the mobile terminal 1 a corresponding to CODEC INF included in the call connection request (SET UP). In addition, the mobile-terminal switching station 5 identifies the attributes of audio data of the mobile terminal 1 b corresponding to CODEC INF included in the response (AUTH RES) received from the mobile terminal 1 b through the base-station controlling unit 3 b.
When the attributes of audio data of the mobile terminal 1 a match the attributes of audio data of the mobile terminal 1 b , after the mobile-terminal switching station 5 performs a certificating process and a channel-allocating process, the mobile-terminal switching station 5 transmits the response (ALERT) to the base-station controlling unit 3 a . Thereafter, the mobile-terminal switching station 5 issues the command (CODEC REQ) for prohibiting transmission of code-converted audio to the base-station controlling unit 3 a.
When the base-station controlling unit 3 a has received the command (CODEC REQ), the base-station controlling unit 3 a sends back the response (CODEC RES) that represents an acknowledgment of the command (CODEC REQ) to the mobile-terminal switching station 5 . Thereafter, the base-station controlling unit 3 a transmits the command (CODEC REQ) for prohibiting transmission of code-converted audio to the base-sation controlling unit 3 b through the mobile-terminal switching station 5 . The call connection controlling portion 42 b of the base-station controlling unit 3 b receives the command (CODEC REQ).
When the call connection controlling portion 42 b has received the command (CODEC REQ), the call connection controlling portion 42 b causes the selecting portion 62 b to select audio data that has not been code-converted by CODEC 41 b and to output the selected audio data to the base station 2 b . After the call connecting process is completed and a communication is started, the base-station controlling unit 3 a adds audio attribute information to audio data that is being communicated. The base-station controlling unit 3 b always identifies the audio attribute information. Thus, a communication can be made without the code-converting process.
Next, with reference to FIG. 1, the structure and operation of an audio monitor unit according to an embodiment of the present invention will be described. The audio monitor unit 8 comprised of a first signal patch 9 including an audio data type determining portion 9 b , an audio data selecting portion 9 c , and the CODEC 9 a . Audio monitor unit 8 is also comprised of a second signal path 10 including a CODEC 10 a , an audio data type determining portion 10 b and an audio data selecting portion 10 c . Signal paths 9 and 10 each to monitor audio data received from one of the mobile terminals 1 a and 1 b that are in communication regardless of the attributes of the audio data. For example signal path 9 monitors audio data from calling-side terminal 1 a , and signal path 10 monitors audio data from called-side mobile terminal 1 b . As previously explained, if the attributes of the calling terminal 1 a match the attributes of terminal 1 b , the mobile-terminal switching station 5 receives audio data that has not been code-converted into PCM audio data. To monitor such audio data, it is necessary to determine the attributes of audio data that is being communicated and code-convert the audio data in accordance with its attributes into PCM audio data.
As shown in FIG. 1, the audio data type determining portions 9 b and 10 d respectively determine the attributes of audio data of the mobile terminals 1 a and 1 b . When audio attribute information has teen added to audio data, the determining portions 9 b and 10 b cause the attribute audio data selecting portions 9 c and 10 c to select audio data that has been code-converted to PCM audio CODEC 9 a and CODEC 10 a , and to output the selected audio data on adder 11 . When audio attribute information has not been added to audio data, the audio data will be in PCM form, and further code conversion is not needed. Thus, the determining portions 9 b and 10 b causes the audio data selecting portions 9 c and 10 c to select audio data that has not been code-converted by the CODECS 9 a and 10 a and to output the selected audio data to adder 11 . Thus, audio data that is output from the audio data selecting portions 9 c and 10 c are always PCM audio data.
The adding portion 11 digitally adds both the audio data and sends the resultant audio data to the audio data outputting portion 12 . The audio data outputting portion 12 decodes the PCM audio data, amplifies the resultant audio data, and outputs the resultant audio data as a sound. Thus, the audio monitoring unit 8 can monitor audio data of two communicating parties regardless of the attributes of the audio data without need to receive a command from the mobile-terminal switching station 5 .
According to the present invention, when mobile terminals having the same attributes of audio data communicate with each other, since it is not necessary to perform the code-converting process (unlike with the conventional system that requires the code-converting process two times), the delay time of audio data can be decreased. In addition, the quality of audio data can be prevented from deteriorating.
In addition, according to the present invention, since a base-station controlling unit on the calling side has a means for prohibiting transmission of code-converted audio to a base-station controlling unit on the called side and a means for identifying audio attribute information added to audio data, the base-station controlling unit on the calling side can autonomously determine whether or not the code-converting process is required without interventions of a mobile-terminal switching station and the base-station controlling unit on the called side. Thus, the above-described effects can be accomplished in a simpler call connecting sequence than before.
Moreover, according to the present invention, an audio monitor unit has a means for identifying audio attribute information added to audio data and a means for determining whether or not the code-converting process is required corresponding to the identified results, the audio monitor unit can monitor audio data of two parties that are communicating with each other regardless of the attributes of the audio data thereof.
Although the present invention has been shown and described with respect to a best mode embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions, and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the present invention. | A mobile communication system in which a calling terminal transmits coding attribute identification information, and called terminal identification information to a central during call initiation. The coding attribute identifies the compression and coding process used by the calling terminal. A paging request generated by the central switching station is then addressed to the called terminal. The called terminal's response includes coding attribute information identifying its compression and coding process. If the coding and compression processes of the two terminals are the same, communication is conducted without conversion to PCM format. The audio signals transmitted by the calling and called terminals are continuously converted to PCM format at the associated base stations, but if the compression and coding processes of the participating terminals are the same, the unconverted audio signals (with coding attribute identification added) are transmitted. If the compression and coding processes do not match, the PCM signals are transmitted. At each base station, the incoming audio signals pass through PCM-to-native-format code converters. If the coding attribute identification is present in the incoming signal (indicating that the compression and coding processes of the two terminals match), the incoming unconverted audio signal is transmitted to the associated terminal. If the attribute identification is absent, the code converted signal is transmitted. | 7 |
REFERENCE TO RELATED APPLICATION
This application is a division of U.S. patent application Ser. No. 577,056, filed May 13, 1975, by the same inventors, now U.S. Pat. No. 3,981,047.
BACKGROUND OF THE INVENTION
This invention relates to a process for assembling textile fibers into loose batts, and is more particularly concerned with a process suitable for high speed production of batts used in preparing high quality nonwoven fabrics.
Contractor and Hwang U.S. application Ser. No. 497,046, now U.S. Pat. No. 3,932,915, and Zafiroglu U.S. Pat. No. 3,797,074 disclose apparatus wherein staple fibers in batt form are fed to a toothed disperser roll which doffs the fibers into an air stream of high uniform velocity and low turbulence to form a thin stream of fibers that are then collected on a moving screen to form uniform webs suitable for further processing into nonwoven fabrics. The web-forming apparatus is capable of high speed operation when fed with uniform batts weighing many times the weight, in ounces per square yard, of the uniform webs produced. Suitable feed batts can be prepared by cross-lapping a plurality of webs formed by a carding or air-laydown machine, but production rates which can be achieved with conventional cross-lappers are limited. Apparatus has not been available for producing batts of the desired basis weight and uniformity without the use of cross-lappers.
The batt-forming apparatus used in the present invention makes possible high-speed production of heavy batts of improved uniformity. Batts weighing 10 to 150 ounces per square yard can be produced without cross-lapping. Its operation, in producing batts of the required uniformity and basis weight, is characterized by lack of sensitivity to the type of fiber, e.g., denier per filament, staple length, crimp and composition. The batt-forming apparatus can be coupled to the web-forming apparatus to obtain high production rates from the combination.
SUMMARY OF THE INVENTION
The present invention is an improvement in a process for separating fibers from a fiber-laden transporting air stream and depositing them on a moving conveyor belt to form a batt of improved uniformity. The process comprises (a) depositing the fibers on a moving conveyor to form a batt, the deposition of said fibers being by the falling of said fibers onto said conveyor, (b) directing a flow of air across the top of said batt to skin off the top layer of fibers therefrom, the flow of air thereby determining the level of said batt, and redepositing the skimmed off fibers onto said batt along with the falling fibers. The skimming off action of the air on top of the batt serves to form the level (height) of the batt without contact with any solid surface, the scraping action of which would form non-uniform regions at the top of the batt. The resultant batt can then be compacted for further processing.
Deposition of the fibers on the belt is accomplished with a stationary chute. The chute has front, back and side plates which form an upright rectangular body. There is an entrance opening at the top for receiving fibers, an opening at the bottom closed by the conveyor belt, and an exit opening in the front plate for a batt of fibers to be carried out of the chute on the conveyor belt. A weir plate is positioned on the front plate with the bottom edge of the weir plate forming the top of the exit opening. A row of air jets extends along the bottom edge of the weir plate for maintaining a constant fiber level at the exit opening. These air jets are directed inwardly toward the back plate and performations are provided in the back plate for escape of air from the chute.
The bottom portion of the back plate is preferably curved forward, in the direction of movement of the conveyor belt, to guide fibers toward the exit opening in the front plate. The chute is preferably provided with a deflector plate projecting inwardly from the front plate to guide fibers away from the front of the chute as they fall from the entrance opening in the top of the chute. Distribution of fibers in the chute can be improved by moving baffle means located beneath the entrance opening. This baffle means may be a plate which is oscillated back and forth about an axis parallel to the back plate, or it may be a plurality of baffles arranged in paddle-wheel formation which are revealed around an axis parallel to the back plate.
After the batt has left the chute, it can be compacted on the conveyor belt with a compactor plate which projects forward from the front plate of the chute at a downward incline. Further compaction can be accomplished with a similarly inclined belt mounted on rollers.
The fibers are supplied to the apparatus in a transporting air stream. They are removed from the air stream with a condenser, which may be of conventional design. When a wide chute is used to produce a wide batt, it may be desirable to feed the fibers into the chute from two or more condensers to get a better fiber distribution.
The row of air jets along the bottom edge of the weir plate acts as an air knife to maintain a constant fiber level at the chute exit by pushing and skimming off small fiber clusters. A very effective leveling action is provided. The basis weight of the batt is proportional to the bulk density of the batt times its height (the fiber level). Under suitable conditions of operation the bulk density of the batt is constant, so the air knife provides a uniform basis weight in ounces per square yard. A different basis weight can be produced by adjusting the weir plate to vary the height of the air jets, and the weir plate can comprise portions which are independently adjustable to vary the jet heights at different locations across the plate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of one embodiment of the apparatus, shown in central vertical section.
FIG. 2 is a perspective view of a similar embodiment of the apparatus.
DETAILED DESCRIPTION
Referring to FIG. 1, the fibers are blown in a stream of air through duct 10 into condenser 12 and pass through chamber 14. Air escapes through perforations 16 and is evacuated through duct 18. The fibers fall through guide member 20 and enter chute 22 through an opening 24 in the top of the chute. The chute has an upright rectangular body constructed of front plate 26, back plate 28 and two side plates. The bottom of the chute is closed by conveyor belt 30. Back plate 28 and the two side plates extend substantially to the conveyor belt. Front plate 26 is shorter to provide an exit opening for a batt of fibers to be carried out of the chute on the conveyor belt. Weir plate 32 is positioned on the front plate with the bottom edge of the weir plate forming the top of the exit opening. A row of inwardly-directed air jets 34 (more clearly shown in FIG. 2) is provided along the bottom edge of the weir plate. The bottom portion of the back plate curves forward to guide fibers toward the exit opening, and perforations 36 are provided therein for escape of air.
The fibers entering the top of the chute are distributed by revolving baffles 38 and fall on deflector plate 40. The deflector plate projects inwardly from the front of the chute. Air from the air jets causes the fibers to swirl around and be deposited to form a batt. The conveyor belt carries the batt to the exit opening where the air jets skim off a layer of excess fibers which are blown toward the back plate and redeposited. The batt is carried through the exit opening and is compacted by oscillating action of a compactor plate 42, which is attached by hinge 43 to the base of the front plate and is perforated over the section 45 covering the batt. Further compaction is accomplished with a belt 44 which runs around a plurality of idler rollers 46.
The construction of a similar chute is shown in perspective in FIG. 2, where like parts are correspondingly numbered. In this specific embodiment an oscillating baffle 48 is used to distribute fibers entering the chute from condenser 12. A row of air jets 34 near the bottom edge of weir plate 32 is provided by drilling a series of orifices of 1/16-inch diameter at every 0.5 inch in a horizontal line across the bottom of the weir plate. The orifices are drilled to direct a flow of air at an upward angle of 30° and are supplied with compressed air from a manifold attached to the plate (not shown). The perforations 36 in back plate 28 provide about 40 percent open area in the perforated region shown.
The perforations in the back plate serve two functions: (1) Air from the air jets 34 escapes through the perforations so that this additional amount of air does not upset the air balance at the condenser 12. (2) The fibers pushed back by the air jets (both descending fibers and fibers skimmed from the batt as it passes out of the chute) collect on the perforated plate and slide down the curved portion of the plate as additional fibers are deposited. The escaping air applies a drag on the descending fiber to reduce differences in bulk density which are caused by nonuniform fiber height and air impact.
The deflector plate 40 is used to guide fiber and air flow to the back plate so that less air is needed at the air jets for pushing back fibers. Best results are obtained when the chute is operated with the fiber level slightly below the bottom of the weir plate. Excessive escape of air through this space would cause the batt to separate below the weir plate. Such damage to the batt is avoided by the action of the deflector plate and the perforated back plate.
As shown in the following examples, the leveling action of the air jets is quite effective. Without the air jets the cross direction batt uniformity averages about 50 percent. Use of the air jets improves the uniformity to about 20 percent. Furthermore, the performance is insensitive to high throughput; the uniformity at 12 pounds per inch of width per hour (pih) is as good as that at 4 pih. When coupled to the web-forming apparatus cited at the beginning of the specification, the final webs produced have good visual aesthetics (freedom from blotches and streaks) and are suitable for producing high quality nonwoven fabrics. Further improvements in batt uniformity can be achieved by minimizing nonuniform and unsteady fiber flow from the condenser. The use of two or more condensers may be desirable, particularly with a wide chute.
Batt uniformity is determined as follows:
The cross direction batt uniformity profile is measured on samples placed under a 6.78 inch × 6.78 inch template. The chute belt is stopped and five samples are taken across the width of a 35-inch wide batt; twelve samples are taken at equal intervals from a 155-inch wide batt. The average basis weight (BW), maximum (BW) and minimum (BW) are determined for each set of samples and batt uniformity is calculated as follows: ##EQU1##
A series of runs is made with apparatus substantially as illustrated in FIG. 2 and as described previously. The chute is 35 inches wide. Polyethylene terephthalate staple fiber, 3/4 inch long and 1.25 denier per fiber, is used to form batts at throughputs ranging from 4 to 12 pounds per inch per hour (pih). In each run, loosely opened clusters of fibers are fed in carrier air to a condenser which separates carrier air and drops the fibers into the chute. The weir plate is positioned at a height of 25 to 36 inches above the conveyor belt depending upon the desired batt weight, which ranged from 35 to 60 ounces per square yard. The air jets on the weir plate are used to maintain the fiber level at the desired height by pushing and skimming off small fiber clusters and creating large-scale vortices to redistribute fibers. Air is supplied to the jets at a pressure ranging from 14 to 20 pounds per square inch gage (psig.) over the throughput range of 4 to 12 pih. The amount of air used corresponds to 0.9 to 1.15 standard cubic feet per minute (SCFM) per inch width of the chute for the pressure range of 14 to 20 psig. Within this range, more air is required for the higher throughputs and for greater amounts of fiber above the level of the air jets. Best results are obtained when the fiber level at the weir plate is about 1 to 2 inches below the bottom of the plate under steady state operation.
Good batts, having values of percent uniformity from 6 to 19, are obtained over the throughput range of 4 to 12 pih. The uniformity values are independent of the pih used in the runs.
EXAMPLE 2
Apparatus similar to that of Example 1, but of approximately 4.5 times the width, is used to prepare batts of the same fibers. The width of the weir plate is 1541/2 inches and the height is 333/8 to 35.5 inches from the conveyor belt to the bottom of the weir plate. Operating conditions are chosen so that the moving batt surface is approximately one inch below the weir plate. The following process conditions are used:
______________________________________Throughput 5 pihConveyor belt speed 34-37 inches/min.Air pressure to jets 5-22 psig.______________________________________
Batts are produced which weight 45 to 50 ounces per square yard and have a percent uniformity of 18 to 24. The visual uniformity is also good.
For comparison, prior to installation of the weir plate with air jets the batt uniformity averaged 50 percent under the best conditions and was 110 percent on one occasion.
Modifications can be made in the apparatus disclosed without departing from the basic invention. Additional means can be provided for distributing fibers as they fall into the chute, e.g., a plurality of plates extending alternately from the back and front plates in cascade arrangement above the deflector plate 40. The air jets 34 can be slit-shaped instead of round, aligned to form a substantially continuous orifice slit parallel to the bottom edge of the weir plate. | A staple fiber batt of improved uniformity is made by the fibers falling onto a moving conveyor, skimming off the top of the batt by jets of air flowing across the top of the batt, which thereby determines the level of the batt, and redepositing the skimmed off fibers onto said batt. The batt can then be compacted for further processing. | 3 |
CROSS REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Patent Application No. 60/700,128, filed Jul. 18, 2005, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates in general to athletic equipment and in particular to protective athletic bands that can be worn about various areas of the human body.
BACKGROUND OF THE INVENTION
Many commercially available athletic bands are dedicated to perspiration absorption. A typical example is an elastic terry cloth band commonly known as a “sweatband” that is may be worn around the user's head or wrist. While well suited to absorbing the wearer's perspiration, sweatbands offer little meaningful protection from impacts arising from speeding balls (or other moving sporting equipment), or contact with other players and playing surfaces.
Other athletic gear are primarily protective in nature and are designed to absorb impacts. These devices are typically much more bulky and complex in construction than conventional sweatbands and are not adapted to provide effective perspiration absorption. An example of such protective gear may be found in U.S. Pat. No. 6,625,820.
Some athletic bands are constructed as a layer of impact-absorbing material wholly or partially contained within a layer of cloth. Examples of such bands may be found in U.S. Pat. Nos. 4,910,804; 5,946,734; 6,000,062; 6,266,826 and 6,675,395, as well as in Published U.S. Patent Application No. 2002/0189004. Of these, however, only U.S. Pat. No. 5,946,734 addresses the advantage of providing “breathable” impact-absorbing cellular material for the wearer's comfort. However, in the sole embodiment thereof which mentions this feature, the “breathable” open-cell foam is a bulky ⅝ to 1 inch in thickness which renders the band thick and bulky in appearance.
An advantage exists, therefore, a thin athletic band which is economical to manufacture yet provides considerable impact protection coupled with effective perspiration removal.
SUMMARY OF THE INVENTION
The present invention is a protective athletic band including a layer of breathable, moisture wicking material and a layer of perforated, impact-absorbent elastomeric material of less than about 3 mm in thickness. The band may be continuous or a strip having first and second detachably connectable ends. The resultant product is a thin athletic band which is economical to manufacture yet provides considerable impact protection coupled with effective perspiration removal.
Other details, objects and advantages of the present invention will become apparent as the following description of the presently preferred embodiments and presently preferred methods of practicing the invention proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more readily apparent from the following description of preferred embodiments thereof shown, by way of example only, in the accompanying drawings wherein:
FIG. 1 is a perspective, partially disassembled view of a protective athletic band according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 reveals a preferred construction of a protective athletic band according the present invention. The athletic band, identified generally by reference numeral 10 , comprises a layer of breathable, moisture wicking material 12 and a layer of impact-absorbent material 14 . Although athletic band 10 is preferably constructed as an endless loop it may also be formed as a strip having first and second ends that are detachably connectable to one another such as by buttons, snaps, hook and loop type fasteners, or the like (not shown).
Moisture wicking layer 12 may be any suitable porous natural, synthetic or blended fabric such as, for example, elastic terry cloth or the like of the type commonly used in conventional sweatbands. According to a preferred embodiment, the moisture wicking layer preferably encloses or envelops the layer 14 of impact-absorbent material.
The impact-absorbent layer 14 is desirably a very thin, elastic, and breathable material. Layer 14 is preferably less than bout 3 mm in thickness so as to provide the band 10 with a very thin profile comparable to conventional sweatbands. According to the invention, layer 14 is a noncellular elastomeric material such as natural or artificial rubber, neoprene, Calprene®, or the like, provided with a plurality of perforations 16 . A suitable material is a perforated, approximately 1.5 mm thick layer of noncellular Calprene® H-6170. The inventor has observed that such material effectively passes moisture from the wearer while at the same time providing more than a 50% reduction in impact force sensed by a wearer as compared to conventional fabric sweatband material alone. It will be appreciated that greater thicknesses, up to about 3 mm, will produce even greater impact absorption without noticeably compromising the thin profile of athletic band 10 .
Layers 12 and 14 may be joined by any suitable means or method. In preferred embodiment, they are sewn together by conventional sewing equipment. The resultant band is thin and breathable and may be worn about any area of a user's body that is, depending on a particular sport, frequently subject to athletic impact such as the head, wrist, elbow and knee.
Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention as claimed herein. | A thin athletic band which is economical to manufacture yet provides considerable impact protection coupled with effective perspiration removal. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation of International Application No. PCT/DE02/02304, filed Jun. 24, 2002, and claims priority to German Patent Application No. 101 30 874.4, filed Jun. 27, 2001, both applications hereby being incorporated by reference herein.
BACKGROUND INFORMATION
The present invention relates to a method for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission and/or an automated clutch in a creep drive mode of the vehicle. The present invention also relates to a method for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission and/or an automated clutch to establish the biting point of the clutch.
When a vehicle having an automated manual shift transmission and/or an automated clutch is moved in a creep drive mode to park in a parking space, for example, it must be ensured that the drive motor is not brought to stop by the driver of the vehicle during a braking procedure. For this purpose, opening the clutch when the driver actuates the brake of the vehicle is already known, it being possible to monitor the brake light switch in order to monitor the braking procedure. Therefore, digital information exists on whether the brake is actuated and the clutch must therefore be opened in order to avoid the engine dying because of the braking torque exerted on the engine.
However, when the driver only wishes to brake a little against a creep torque transmitted by the clutch during maneuvering, this procedure corresponds to a different driver intent than the sharp braking by the driver in order to avoid a collision during the parking procedure, for example.
By monitoring the engine speed, it is possible to activate more rapid opening of the clutch if the instantaneous engine speed falls below the engine-specific idle speed for a predetermined period of time. However, if a diesel engine is used as the drive motor, it reacts significantly more rapidly than a gasoline engine to a reduction in the engine speed, through an increase in the engine torque output because of the combustion, so that a noticeable drop in the engine speed may not be perceived, but rather the driver of the vehicle would perceive a push of the engine against his braking intent.
For the adaptation of the touch point or biting point of the clutch, exploiting the reaction of the engine in the event of an activation of the clutch using touch ramps when the brake is actuated is known. For this purpose, a low clutch torque is built up with an initially open clutch and the torque output by the engine is monitored. If the engine torque increases by a specific value over a specific period of time in relation to the engine torque before the touch point adaptation, then the biting point established by the clutch controller must be corrected in the open direction. For such a procedure, it is possible that the vehicle will roll free if the brake is only lightly actuated.
BRIEF SUMMARY OF THE INVENTION
The present invention is thus based on an object of providing a method for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission and/or an automated clutch in a creep drive mode which remedies the disadvantages described. In addition, the method for establishing the biting point of the clutch may also be improved.
According to the present invention, a method is thus provided for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission in a creep drive mode of the vehicle, according to which the clutch torque is changed as a function of at least one variable operating parameter of the vehicle which describes the creep drive mode of the vehicle. Very generally, this means that according to the present invention, one or more operating parameters of the vehicle are monitored which describe a slow drive mode or creep drive mode of the vehicle and, as a function of the operating parameter(s), the torque transmitted by the clutch is changed. Therefore, the creep drive mode of the vehicle may be improved in relation to the known method without the danger of the engine dying, since no longer only digital information in the form of the brake light switch is analyzed, but rather one or more operating parameters, which do not change digitally and which describe the creep drive mode of the vehicle, are analyzed.
Therefore, for example, in the event that there is a danger of the engine dying, the clutch torque may first be reduced at a relatively high speed, as a function of the operating parameter(s), and the clutch torque may then be reduced at a lower speed, so that, compared with a linear reduction of the speed of the clutch torque, a more comfortable creep drive mode is available that takes the driver's intent, which may be represented by an actuation of varying strength of the vehicle brake by the driver, for example, into consideration.
Therefore, according to one aspect according to the present invention, the operating parameter is the strength of the actuation of a vehicle brake which influences the speed of the vehicle. The strength of the actuation of the brake of the vehicle by the driver may therefore be considered, i.e., for example, the brake pressure for a hydraulic braking system or a current value, using which an electromechanical brake of the vehicle is actuated. In the event of a strong actuation of the brake by the driver, according to the present invention, the clutch is opened more rapidly and the clutch torque is therefore reduced more rapidly, since otherwise a braking torque would be transmitted via the transmission to the engine via the still closed or partially closed clutch, so that the engine speed would fall too greatly. A further reduction of the clutch torque may then occur at a lower speed, so that the comfort in the creep drive mode is improved and the creep drive mode is prolonged. Such behavior then corresponds to the behavior of a vehicle having a stepped automatic transmission.
Therefore, according to a further aspect according to the present invention, the operating parameter is the rotational speed and/or the engine torque and/or a variable of the drive motor of the vehicle derived therefrom. If a drop in the engine speed is perceived during the creep drive mode, due to a braking procedure initiated by the driver, for example, which leads to an engine speed significantly below the engine-specific idle speed for a predetermined duration, i.e., to a reduction of more than 100 rpm below the idle speed, for example, according to the present invention the clutch torque is reduced using a higher gradient than would be necessary in the event of lighter braking by the driver. In a similar way, the clutch torque is reduced more strongly if it is observed that the engine torque resulting from the combustion increases during braking significantly over a value of the engine torque typical for the idling of the engine. This typical value may be established as an average of the engine torque during creep before the actuation of the brake, for example. If an electric motor or a hybrid drive is used as the drive motor, the average value of the torque output during the creep drive mode before the actuation of the brake may also be established in a similar way.
Therefore, the typical torque behavior of the drive motor in idle is analyzed. If the engine reacts to braking with a significant increase in the torque, which may mean an increase to a value of more than 10 Nm, for example, the clutch torque is then reduced rapidly and the clutch is transferred into a slipping state. In this state, the clutch transmits a lower braking torque to the engine, and the engine torque for maintaining the idle speed no longer increases. The clutch torque may then be reduced using a lower gradient, having a value of 5 Nm/sec, for example.
In a similar way, according to the present invention, the clutch torque is reduced using a higher gradient if a drop in the engine speed is observed with an essentially negative gradient. Such a case exists, for example, when the engine speed is reduced using a gradient of 25 rad/s 2 , for example, which approximately corresponds to a reduction in the engine speed at a value of 250 rpm/sec.
According to a further aspect according to the present invention, the operating parameter is a rotational speed differential between the clutch input side and the clutch output side. This may be a rotational speed differential between the engine speed and the transmission input shaft speed, for example.
The method according to the present invention may also be advantageously used in power trains in which the clutch is not positioned between a drive motor and the transmission input, but rather at the output of the transmission or inside the transmission, for example. Thus, for example, positioning the clutch between a shaft and the transmission housing, in the event of which the clutch may act as a brake, or even, in transmissions with branched structures, positioning the clutch between two branches inside the transmission, is also possible. The action of the clutch and/or the brake on the engine then corresponds to the application in which the clutch is positioned between the engine and the transmission input.
In this case, it is provided according to the present invention that the clutch torque is reduced with a stronger approach when there is no essential rotational speed differential, since the clutch then does not yet operate with a significant slip. Therefore, the clutch is transferred more rapidly into a slipping state, through which the braking torque exerted on the engine via the clutch is reduced and the vehicle moves further in the creep drive mode. The clutch torque may then be reduced further at a rate of 5 Nm/sec, for example. Therefore, maneuvering which is comfortable for the driver may be implemented using the actuation of the brake against the creep torque. Through the initially great reduction in the clutch torque, the braking torque exerted on the engine is lower than the output torque provided by the engine in idle mode, so that the danger of the engine dying is eliminated and the driver may maneuver comfortably using the actuation of the brake.
According to a further aspect according to the present invention, the operating parameter is an accelerator pedal value. Therefore, if the brake and accelerator pedal or gas pedal are actuated simultaneously, a clutch torque may be set which allows the curb to be approached comfortably and is a function of the strength of the actuation of the brake and the accelerator pedal.
Using the change in the clutch torque as a function of at least one operating parameter of the vehicle provided according to the present invention, comfortable torque tracking may also be implemented. For this purpose, a driver's intent expressed by the actuation of the brake may advantageously be analyzed, since it may be assumed therefrom that there is a high probability that the driver wants to stop or he wants to cause a downshift action of the automated manual shift transmission if he actuates the brake of the vehicle strongly. The shifting time may be shortened if the minimum torque to be transmitted by the clutch is reduced starting from a specific threshold value of the strength of actuation of the brake, so that the opening of the clutch occurs rapidly. Therefore, it is also provided according to the present invention that the minimum torque and, in the course of the torque tracking, the torque to be transmitted by the clutch is reduced starting from a predetermined threshold value of the strength of the actuation of the brake of the vehicle, since the time necessary for opening the clutch is therefore reduced. It is possible in this case to perform the reduction of the minimum torque over multiple steps on the basis of multiple threshold values or even as a function of a brake pressure gradient.
The information obtained according to the method described above may also be used for the touch point adaptation.
According to one aspect of the present invention, a method is therefore also described for changing the clutch torque of a clutch in the power train of a vehicle having an automated manual shift transmission to establish the biting point of the clutch, in which the biting point established is shifted in the direction of an open clutch if the total torque of the engine torque and the engine moment of inertia exceeds a threshold value in the event of a reduction of the engine speed.
If it is determined during a braking action that the engine torque output by the engine plus the torque resulting from the reduction of the engine speed increases significantly, advantageously by more than 20 Nm, above a value characteristic for the idling of the engine, then, according to the present invention, the biting point of the clutch established by the controller is shifted toward the direction of the open clutch. This biting point established in this way is then used as the future biting point.
In a similar way, the biting point established is shifted in the direction of an open clutch if a rotational speed differential between the engine speed and the transmission input shaft speed is detected which is greater than a threshold value and the total torque exceeds the threshold value. Therefore, upon recognition of clutch slip and the sum of engine torque and engine moment of inertia being exceeded, the software biting point and/or the biting point established by the controller is shifted in the direction of the open clutch, and the controller will therefore disengage the clutch further in the future, since the biting point previously established as the setpoint value was too low in spite of slip in the clutch and the engine, in particular a diesel engine, has reacted thereto with a torque increase.
According to a refinement of the present invention, the biting point established is shifted in the direction of an open clutch if the rotational speed differential was detected, i.e., clutch slip has occurred for the first time and the engine speed falls below the idle speed. This variant is preferably applicable for a gasoline engine.
Very generally, it is therefore provided according to the present invention that the biting point established is shifted in the direction of an open clutch as a function of at least one operating parameter of the vehicle. This may also be the temperature of the clutch, for example.
According to the present invention, a further creep function of the vehicle is provided in such a way that the clutch torque is set to a further creep torque to maintain a creep drive mode if the accelerator pedal and the brake of the vehicle are not actuated. Therefore, an existing creep drive mode of the vehicle is maintained at the same level, for example during parking, if the driver does not operate the brake and the accelerator pedal.
According to the present invention, the further creep torque may be set in all gear stages, i.e., not only in the starting gears, for example the first and second gears as well as the reverse gear, but rather in all gear stages or driving stages provided by a transmission coupled to the clutch. This further creep torque may then be reduced if, on the basis of a rotational speed differential at the clutch causing the further creep drive mode, it is determined that clutch slip exists and therefore the output torque provided by the engine is no longer sufficient to maintain the further travel. Maintaining the further creep torque would then only lead to heating of the clutch because of increasing friction power.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described in greater detail in the following on the basis of the drawing.
FIG. 1 shows a diagram with a schematic illustration of the change in the clutch torque;
FIG. 2 shows a diagram with a schematic illustration of the change in the clutch torque in the event of the biting point adaptation if the biting point is too low;
FIG. 3 shows a diagram similar to FIG. 2 and a biting point that is too high; and
FIG. 4 shows a diagram with the curve of the clutch torque in the creep drive mode.
DETAILED DESCRIPTION
FIG. 1 of the drawing shows a schematic illustration of the change in the clutch torque as a function of the strength of the actuation of the brake by the driver of the vehicle.
This is a qualitative illustration, using which the method according to the present invention is to be explained. The region identified with A shows curves when the driver of the vehicle brakes only lightly, while the region identified with B shows curves in the event of strong braking.
In region A, engine speed 1 of engine 10 and transmission input shaft speed 2 of transmission 12 run largely uniformly and fall slightly due to the light braking action on brake 14 . Clutch torque 3 of clutch 16 also falls slightly, while engine torque 4 of engine 10 increases slightly. The clutch is closed and operates essentially without slip. This may be the situation when parking.
If the driver now actuates the brake more strongly, it is provided according to the present invention that clutch torque 3 is reduced with a higher gradient than is the case in the event of light braking, as shown in region A. The engine has reacted to the stronger braking during the creep drive mode with an increase in engine torque 4 , whereupon clutch torque 3 is reduced using increasing gradients. Through the braking action, engine speed 1 is reduced, but clutch torque 3 has already been reduced significantly more strongly. Transmission input shaft speed 2 falls significantly, and the engine no longer has a high braking torque applied to it. Since the rotational speed drop of the engine comes to an end, the engine no longer reacts with an increase in engine torque 4 , and torque curve 4 drops further.
Although the case of an initially light braking action followed by a stronger braking action is illustrated in FIG. 1 , the reverse case may also exist, in which the driver initially brakes more strongly and then reduces the braking force. In this case as well, the clutch torque is reduced with a higher gradient during the stronger braking action than during a lighter braking action.
FIG. 2 shows curves for a biting point of the clutch that has been established too low by the controller. The region with a gray background shows that engine speed 1 falls greatly and the engine reacts with a significant increase in engine torque 4 and attempts to compensate for the drop. Clutch torque 3 has already been significantly reduced, the clutch slips, and engine torque 4 nonetheless rises. The biting point used by the controller of the clutch as the setpoint biting point is too low and is to be shifted in the direction of an open clutch.
FIG. 3 shows curves in the event of a biting point of the clutch that has been established too high by the controller. The region with the gray background shows that engine speed 1 remains unchanged in the adaptation time, i.e., the clutch is already open too far. The controller of the clutch has therefore set a setpoint biting point that is too high. The new setpoint biting point of the clutch is therefore to be shifted in the direction of a closed clutch.
Finally, FIG. 4 of the drawing shows a diagram with the curve of the clutch torque in the creep drive mode. The creep torque may be between 10 Nm and 15 Nm, depending on the vehicle, and is high enough that the vehicle moves at a low speed. The creep torque is set at the clutch if the first gear, the second gear, or the reverse gear is engaged, the brake is not actuated, and the accelerator pedal is also not actuated.
The method provided according to the present invention thus differs from the method previously described having ramped buildup to the biting point in that a clutch torque which is a function of the strength of the actuation of the brake is built up in such a way that the creep torque is already set starting from a specific threshold value, i.e., the clutch is already somewhat closed starting from the threshold value. Therefore, according to the present invention, the signal indicating the strength of the actuation of the brake is filtered in order to take possible signal noise into consideration.
Creep torque 5 is changed as a function of the operating parameter of brake pressure in the example shown in FIG. 4 , in such a way that it is built up even at a still existing filtered brake pressure 6 , which results from brake pressure 7 . Therefore, a significantly better ability to meter the creep torque is achieved than was the case in the previous ramped buildup of the creep torque, in which the creep torque was first built up when the brake light switch of the vehicle signaled release of the brake. Through the buildup of the creep torque as a function of the brake pressure, it is possible to approach the curb comfortably when the vehicle is on a slope.
Instead of the operating parameter of brake pressure or the strength of the actuation of the brake, a gradient thereof may also be used as a parameter for the change in the clutch torque. Thus, for example, the clutch torque may be increased rapidly if the brake pressure gradient is high and the driver initiates a gear change action, since it may be assumed therefrom that the driver wishes to use the engine drag torque for braking.
Besides the signal representing the strength of the actuation of the brake, the digital brake light switch signal is also still available for analysis. This may be transmitted to the control unit via the CAN (controller area network) bus of the vehicle. If there is a further redundant brake light switch signal, a plausibility check of the signal may be performed and a source of error may be concluded in such a way that if there is no brake light switch signal transmitted outside the CAN bus, for example, a line interruption may be concluded. In the event of an implausible CAN signal, a defective control unit may be concluded, while in the event of an implausible brake pressure signal, a defect of the brake pressure sensor may be concluded. | A method for altering the coupling torque of a coupling in the drive train of a vehicle with an automatic gearbox and/or automatic coupling in a creep drive mode of a vehicle. According to the invention, the coupling torque is altered according to at least one variable, the parameter of the vehicle describing the creep drive mode thereof. | 5 |
The invention described herein was made in the performance of work under NASA Contract No. NAS 8-36200, and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, as amended (42 U.S.C. 2457).
FIELD OF THE INVENTION
This invention relates to welding, and more particularly to arrangements for providing an inert gas adjacent the material being welded, where the material being welded is supported at locations along the length of the seam.
BACKGROUND OF THE INVENTION
The Space Shuttle external fuel tank is a tank 271/2 feet in diameter, 153 feet long, made from 0.080 inch thick lithium-aluminum alloy. These tanks are made by welding together several cylindrical sections, together with hemispherical end sections. Welding of the seams between sections is rendered difficult by the need to align the edges being welded to within 0.003 inch during the welding operation, and because of the need for essentially perfect, nonporous, void- and contaminant-free welds.
In order to position the sections of the tank preparatory for welding, the various tank sections are mounted on an internal mandrel having a horizontal axis. The mandrel is rotatable about its axis, so that the tank sections can be rotated to present all portions of one of the circumferential butt joints to a welder. The thin material of the tank sections would sag to a noncircular form, and cause mismatch and peaking between the surfaces, if it were not supported. Support is provided to the edges of each of the adjacent sections being welded by mutually adjacent portions of the mandrel. The portion of the mandrel adjacent to, and in actual contact with the tank section, is made up of a plurality of radially extending screws. These screws allow the "shape" of the mandrel to be adjusted slightly before welding, so that the tank sections are circular to within the desired tolerance, and so that the abutting edges which are to be welded are within the desired 0.003 inch radial tolerance. When the welding is finished, the internal mandrel is disassembled and removed through an access port.
The aluminum-lithium alloy from which the tank is made tends to oxidize at the temperatures necessary for welding. This oxidation is disadvantageous, in that it can result in porosity, voids, inclusions, or other defects in the welded seam. Improved welding is desired.
SUMMARY OF THE INVENTION
A welding arrangement, for welding the edge of a sheet of thin material to a second sheet of material which it abuts, includes a welder located on one side of the sheets of material to be welded. On the other side of the sheet, a support arrangement holds the edge of the sheet of thin material in a desired configuration. In a preferred embodiment of the invention, the configuration is circular. The support arrangement includes a support, with adjusters extending from the support to locations near the edge of the sheet of thin material to be welded. In the preferred embodiment of the invention, the adjusters are radially adjustable screws. In that embodiment, the sheet of thin material is a cylindrical sheet, the edge of which is to be welded to the second sheet. In order to improve the quality of the weld, the side of the sheet of thin material opposite to the side with the welder is associated with a chamber, which is purged with a gas (a purge chamber), preferably an inert gas, so that the reverse side of the seam being welded is bathed in the inert gas, thereby tending to improve the quality of the weld. The chamber is controlled to maintain a seal notwithstanding the presence of the adjusters, which move through the chamber during the welding procedure. The controllable chamber is defined, in part, by a fixed vane or side plate projecting perpendicular to the second sheet, and parallel to the edge of the sheet of thin material which is to be welded. A rear wall of the controllable chamber, extending roughly parallel to the sheet of thin material, and on the opposite side of the sheet of thin material to be welded from the welder, is fixed in position relative to the welder, so that the chamber is always maintaining the inert gas adjacent that portion of the butt joint being welded. The rear wall has an edge extending along, or contiguous with the vane (where "contiguous" means either (a) in actual contact with the vane, or (b) close to the vane, but not in actual contact with the vane), so as to form a seal tending to retain gas in the chamber. A slotted wall extends roughly parallel to a portion of the vane, but spaced therefrom, and in intimate, gas-tight contact with the rear wall, and extending to, and being contiguous with, the sheet of thin material. The vane, the rear wall, the slotted wall, and the combined sheets of thin material and second material, together form four walls of the controllable chamber. At least three gates or tongues are controlled to extend or project through the slots in the slotted walls. In a preferred embodiment of the invention, four gates are used. When projecting through the slots, the gates extend far enough to be contiguous with the vane. The gates are controlled so that two of the gates are always in the inserted position, while at least one gate may be in a retracted position, so that a closed chamber is defined between the abovementioned four walls and the two inserted gates. The closed purge chamber is located on the reverse side of the sheet of thin material from the welder, and in line therewith. As the edge of the sheet of thin material moves relative to the welder and to the controllable chamber, the gates are controllably retracted and extended so as to clear the adjustment devices, allowing the adjustment devices to pass through the chamber, without allowing excessive amounts of ambient air to dilute the inert gas. As each adjustment device approaches the controllable chamber, the nearest inserted gate retracts to clear the adjustment device to allow it to pass and to enter the chamber, and the gate is reinserted into its slot when the adjustment device passes that slot's position. In a particular embodiment of the invention, the gate control is based upon proximity sensors.
DESCRIPTION OF THE DRAWING
FIG. 1 is a simplified perspective or isometric view of the overall workpiece, support, controllable chamber and welder in accordance with the invention;
FIG. 2 is a detail of the support arrangement of FIG. 1, without the workpiece;
FIG. 3 is a highly simplified edge view of a workpiece consisting of two adjacent cylindrical shells, a support ring, and the associated portion of the support structure;
FIG. 4 is a perspective or isometric view of a purge chamber in accordance with the invention, separate from the workpiece, and showing the relative location of the welding head during operation;
FIGS. 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j and 5k are simplified developed views of the controllable chamber in various positions of the workpiece support;
FIG. 6 is a simplified block diagram of the control arrangement for operating the movable gates of the controllable chamber in response to the positions of the adjusting screw support bosses, as sensed by proximity sensors; and
FIGS. 7a, 7b, and 7c are time plots of various control signals associated with the control arrangement of FIG. 6.
DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective or isometric view of workpiece, with the workpiece 8 partially cut away to reveal a portion of the support arrangement for the workpiece. In FIG. 1, the weld head 38 and its support 39 are illustrated as being at a distance from the workpiece. FIG. 2 is a more detailed view of the support arrangement within the workpiece. In FIG. 1, end support towers 12 and 14 support a central structure 16 equivalent to an axle, which is centered on an axis 4. Structure 16 includes a box beam 18 and at least one circular bearing 20, better seen in FIG. 2. First and second spaced-apart, mutually parallel fixed trusses or beams 22 and 24 are affixed to, and extend from box beam 18 horizontally toward one side of the structure, and have sufficient room between the beams to accommodate a circular support mandrel 26. Circular support mandrel 26 is rotatable about box beam 16 on bearing 20, and is driven by a motor 27 and cog 28, which engages a circular gear (not illustrated). A controllable purge or gas chamber 32 is affixed to the end of beam 22 remote from box beam 18, and a controllable purge chamber 34 is affixed to the end of beam 24. Beams 22 and 24 hold the controllable purge chambers 32 and 34, respectively, adjacent the centerline 36 of the weld head 38.
The workpiece to be welded in the arrangement of FIG. 1 consists of a tank 8 made up of a plurality of thin cylindrical shells or sheets 40, 42, 44, and hemispherical end caps 46 and 48. These cylindrical shells are fabricated by welding together sections of cylinders, so that each cylindrical shell which is to be welded in accordance with the invention already has seams, some of which are designated 98 in FIG. 1. These cylindrical shells are also so thin, about 0.080 inch, that they tend to sag due to gravitational effects, and to therefore take on a non-circular shape, in the absence of support. In order to provide additional support for the tank 8 in its fabricated state, each thin cylindrical shell or hemispherical cap section 40, 42, 44, 46, and 48, is affixed to its adjacent portion of tank 8 by means of an intermediary support ring. In FIG. 1, the support rings are designated 60, 62, 64, and 66. Thus, for example, cylindrical shell 40 abuts, and is welded to, one edge of a support ring 66, and hemispherical end piece 46 abuts, and is welded to, the other edge of support ring 66. Similarly, the edges of cylindrical shell 40 and 42 abut opposite edges of support ring 64, and are butt-welded thereto. The support rings 60-66 are about 8 inches wide, and 0.080 inches thick, and include a reinforcing rib as described below.
One or two seams may be welded at a time, namely one or both of those seams which are associated with one of the support rings 60-66. Consequently, welding may be performed on one edge of one of support rings 60-66 and the adjacent abutting edge of one of cylindrical shells 40-44 or end caps 46, 48, or welding may be performed on one edge of one of support rings 60-66 and the adjacent abutting edge of one of cylindrical shells 40-44 or end caps 46, 48, while at the same time, welding is also performed on the other edge of the same one of support rings 60-66 and the adjacent abutting edge of one of cylindrical shells 40-44 or end caps 46, 48. For example, the seam between cylindrical shell 40 and support ring 64 may be made, followed by a weld of the other edge of support ring 64 to adjacent cylindrical shell 42, or welds may be made simultaneously to both edges of support ring 64. If one edge is welded at a time, it is undesirable to disassemble the support structure to move it to the other edge of the support ring to make that weld, because of the need to realign all of the structures to within the desired tolerances. Consequently, two purge chambers 32, 34 are provided even if the welds are to be made individually, so that both welds can be made with the aid of an atmosphere of inert gas.
Support for the edges of the support rings and of the cylindrical shells to which they are to be welded is provided by two sets of radial adjusters, designated 50 and 52 in FIG. 2, associated with support mandrel 26. Set 50 of radial adjusters is adjacent the edge of cylindrical shell 40, and set 52 of radial adjusters is adjacent the abutting edge of support ring 64. The radial adjusters in a preferred embodiment of the invention are threaded screws, illustrated in greater detail in FIG. 3, which are individually adjustable in a radial direction. The radial screws allow the cylindrical shell to be juxtaposed to the support ring, with the outer surfaces aligned to within the desired 0.003 inches, notwithstanding their tendency to sag, and notwithstanding the difference in thickness between the two adjacent rings which are to be joined.
So far not yet described in conjunction with FIG. 1 are external compression bands, two of which are illustrated as 72a and 72b, which surround and compress the cylindrical shells and support rings against the support structure on the interior, leaving the seams exposed so that they can be welded. These compression bands provide additional support to the structure both before and after it is welded, and are removed before the tank is used.
FIG. 3 is a highly simplified cross-sectional or edge view of two adjacent cylindrical shells and their associated support ring, illustrating how the adjustment screws support the surfaces of the sheets and rings in position. Elements of FIG. 3 corresponding to those of FIGS. 1 or 2 are designated by the same reference numerals. In FIG. 3, an edge view of cylindrical shells 40 and 42 illustrates support ring 64, seen in cross-section, with its reinforcing rib 364. Also visible in FIG. 3 is a cross-section of circular support structure 26, and of the bearing 20 on which it rotates. Also in FIG. 3, threaded screw support bosses 310, 312, 314, and 316 are supported by integral circular support structure 26. Screws 320, 322, 324, and 326 are threaded into bosses 310, 312, 314, and 316, respectively, and project sufficiently to engage the interior surfaces of cylindrical shells 40, 42, and support ring 64. The edge of the butt junction between cylindrical shell 40 and support ring 64 is designated 96, and the corresponding butt junction between support ring 64 and cylindrical shell 42 is designated 94. These are the junctions which are to be welded.
FIG. 3 also illustrates two 360° vanes or side plates 330, 332, which extend completely around the interior of support structure 26, with their outer edges contiguous with the interior surface 364 of support ring 64. In this context, the term "contiguous" means "adjacent to and in physical contact with" or "adjacent to and not in physical contact with". The salient requirements are that the flow of gas through the gap between the outermost edge of 360° vanes 330, 332 and the adjoining inner surface portion of support ring 64 should be relatively low. For this purpose, a gasket or sealing member 330S and 332S is associated with vanes 330 and 332, respectively. Since the vane does not move with respect to the cylindrical shells or the support ring, the seal is not difficult to make. Each vane 330, 332 is supported by support structure 26.
A further set of structures illustrated as 382 and 432 are supported by trusses 22 and 24 of FIG. 2 (not visible in FIG. 3) in a position which is fixed relative to the rotating cylindrical shells and support structure 26. To allow for this motion, structures 382 and 432 of FIG. 3 are spaced away from rotating support structure 26, except at a seal surface 382S associated with structure 382, and a seal surface 432S associated with structure 432. Structures 382 and 432 are contiguous with the inner surfaces of cylindrical shells 42 and 40, respectively, and sealing is aided by seals 386 and 384, respectively.
The 360° vanes 330, 332, possibly together with other structures, each form a part of one wall of an associated purge chamber. The purge chamber associated with vane 330 in FIG. 3 is designated generally as 350, and the purge chamber associated with vane 332 is designated as 352. The surface of 360° vane 330 facing purge chamber 350 is perpendicular to the interior surfaces of cylindrical shells 40 and 42, and also perpendicular to at least a portion of the interior surface of support ring 64, in the local view of FIG. 3. Similarly, the surface of 360° vane 332 facing purge chamber 352 is perpendicular to the interior surfaces of cylindrical shells 40 and 42, and also perpendicular to at least a portion of the interior surface of support ring 64. Thus, vanes 330 and 332 are perpendicular to the axis 4 of bearing 20. The interior surface portions of cylindrical shell 40 and support ring 64 adjoining purge chamber 350 make up another wall of the purge chamber, and a rear (relative to the exterior of the tank) wall 340 of purge chamber 350, interrupted by bosses 310 and 312, is formed by a portion of support structure 26, as can be seen in FIG. 3. Rear wall 340, in the regions which are not interrupted by bosses, has an edge 340a which is contiguous with the adjacent vane 330, so that gas cannot flow past the junction of vane 330 and support structure 26. Rear wall 340 is at a predetermined distance from cylindrical shell 42 and support ring 64. Similarly, the interior surface portions of cylindrical shell 42 and support ring 64 adjoining purge chamber 352 make up another wall of the purge chamber, and a rear wall 342 of purge chamber 352, interrupted by bosses 314 and 316, is formed by another portion of support structure 26. Rear walls 340 and 342 extend essentially parallel to the corresponding interior surface portions of cylindrical shells 40,42 and of support ring 64. More specifically, vane 330, wall 340 of support structure 26, and those portions of cylindrical shell 40 and support ring 64 which are adjacent to butt junction 96 make up three walls of a roughly rectangular purge chamber 350, of which only a portion can be seen because of bosses 310, 312. Similarly, vane 332, wall 342 of support structure 26, and those portions of cylindrical shell 42 and support ring 64 which are adjacent to butt junction 94 make up three walls of another purge chamber 352. Both purge chambers are on the inside of the tank, on the opposite side from welding head 38.
A fourth wall of purge chamber 350, as seen in FIG. 3, is designated 366, and is a part of fixed structure 432. Wall 366 extends perpendicular to the interior surface of cylindrical shell 40 in the region illustrated in FIG. 3. A corresponding surface 368 of structure 382 forms at least a portion of the fourth wall of purge chamber 352. The two remaining walls which are required to close each of the purge chambers are made by a plurality of movable gates or tongues, controlled by cables. In FIG. 3, a first gate 536b is illustrated in its inserted position, in which it extends all the way from structure 432 on the left of purge chamber 350 to butt against wall 330 at the right of chamber 350. The position of gate 536b is controlled by a cable 538b which is attached to gate 536b at a flange 398. Also in FIG. 3, another gate 436a is illustrated in its retracted position, in which its control cable 438a pulls the gate to a position which places that edge of gate 537, which is remote from cable 438a, flush with wall surface 368 of purge chamber 352. With gate 436b in its retracted position, the surface of another gate 436b, which is in the inserted position, may be seen at the far end of purge chamber 352. Each purge chamber is associated with at least three gates, any two of which are always in the inserted position, to close off the two controllable sides of the purge chamber, while another gate may be retracted to clear a screw mounting boss such as 310 or 312.
Also visible in FIG. 3 is a pipe 454, which conducts inert gas to a plenum 455 extending through structure 432. Plenum 455 communicates with a diffuser 452, which allows the inert gas to enter purge chamber 350 by way of the gap between structure 432 and support structure 26. A similar arrangement, including pipe 554, plenum 555, and diffuser 552, is associated with purge chamber 352.
FIG. 4 is a perspective or isometric view, in somewhat more detail, of the welding arrangement of FIGS. 1, 2, and 3, with the workpiece consisting of cylindrical shell 42 and support ring 64 cut away along juncture 94 to reveal those portions of the vane 332 and support structure 26 associated with purge chamber 352, together with other portions of the structure of the purge chamber, and ancillary structures. In FIG. 4, several bosses 314a, 314b, 314c, and 314d, and their corresponding adjustment screws 324a, 324b, 324c, and 324d, are illustrated in the positions which they take, extending parallel to junction 94, for supporting support ring 64 in position. Similarly, bosses 316a, 316b, 316c, and 316d are illustrated, holding their corresponding radial adjustment screws 326a, 326b, 326c, and 326d, as would be required to hold cylindrical shell 42 in position. Vane 332 is positioned adjacent boss set 314, extending perpendicular to the local inner surface of support ring 64, and also perpendicular to the projection of the local inner surface of cylindrical shell 42. Structural element 382 is slotted, and extends parallel to vane 332, but on the side of boss set 316 remote from junction line 94. Thus, as mentioned, vane 332 acts as a side or wall of purge chamber 352, and structural member 382 is, in principle, a corresponding opposite wall. As illustrated in FIG. 4, structural member or wall 382 is slotted, having mutually parallel transverse slots 434a, 434b, 434c, and 434d, through which corresponding gates or tongues 436a, 436b, 436c, and 436d may extend. Gates 436a and 436c are illustrated in their "inserted" positions, in which they extend through their corresponding slots, and into contiguous relationship with vane 332. Gates 436b and 436d are illustrated in their "retracted" positions, in which the gates are withdrawn so that only their tips occlude the aperture of their corresponding slots, to tend to block the flow of gas through the slot. The purge chamber 352 in FIG. 4 is the volume indicated by hatching, and extending between the vane 332 and slotted wall 382, and between upper inserted gate 436a and lower inserted gate 436c. As mentioned, the "back" wall of the purge chamber is a portion of slotted structure 382.
In FIG. 4, gate 436a is actuated by a mechanical cable 442a, which terminates at a support bracket 440a, and which has an actuation cable 440a extending to a lip on gate 436a. Mechanical cable 442a may be actuated from a remote location by a solenoid, hydraulic cylinder, motor, or the like, under control of a proximity sensor, as described below. In a similar manner, mechanical cable 442b is supported by a bracket 440b, and has a central actuator cable 438b which extends to a lip on gate 436b. Mechanical cables 442c and 442d are supported by brackets such as 440c and 440d, and include actuator cables 438c and 438d which are connected to gates 436c and 436d, respectively.
In FIG. 4, inert gas is introduced into purge chamber 410 by way of a gas pipe 454, which allows inert helium gas to enter plenum 455 (not visible in FIG. 4) and to be coupled to a porous diffuser chamber 452. The diffuser chamber receives the inert gas from a pipe 454, and allows the gas to enter the purge chamber evenly, as mentioned above, by way of a gap in the structure. The helium gas is light, and tends to rise through the purge chamber. This tendency is counteracted by allowing a mixture of inert argon gas and inert helium gas to enter the upper end of the purge chamber by way of a pipe 456. The argon gas is heavier than helium, and its weight tends to hold the underlying helium gas in place. No exhaust port is necessary, as the structure has sufficient gaps associated with the seals so that the inert gas leaks out, but oxygen is purged from the interior of the purge chamber.
FIGS. 5a-5i (where the hyphen represents the word "through") are simplified representations of the positions of the various screw support bosses 316 and 324, as developed from a cylindrical surface to the plane of the FIGURES, together with the inserted and retracted positions of the gates 436 of the arrangement of FIGS. 1, 2, 3, and 4 at various times during their sequential operation. In FIG. 5a, vane 332 moves downward relative to structure 382, carrying with it bosses 314 and 316. As illustrated in FIG. 5a, bosses 314a, 314b, and 314c are interleaved in the direction of motion with bosses 316a, 316b, 316c, and 316d. Each boss bears a screw 324 or 326, seen in end view. In FIG. 5a, gates 436a and 436c are in their retracted positions, in which their tips occlude their respective slots 434a and 434c; gates 436b and 436d are in their inserted positions, with their tips contiguous with vane 332. The purge chamber is defined between the inserted gates 434b and 434d. The axis 36 of the welding head lies half-way between gates 436b and 436c. Two bosses are located within the purge chamber, namely bosses 316c and 314b, and boss 316c has its upper side contiguous with the lower side of gate 436b. Another boss 316b has its upper side contiguous with the lower side of lowermost gate 436d, but boss 316b is not within the purge chamber. Also illustrated in FIG. 5a is a first proximity sensor, illustrated as a light source 512 and a light sensor 510, and a second proximity sensor, illustrated as a light source 518 and light sensor 516. In the illustrated positions of the bosses, light sensor 510 receives light from source 512, and produces an output indicating that the bosses are not at gate 436d, while sensor 516 indicates that a boss is near gate 436c. As described below in conjunction with FIGS. 6 and 7a-7c, a control circuit, in the position of the gates illustrated in FIG. 5a, does not respond to the signal from sensor 516.
FIG. 5b represents the arrangement of FIG. 5a after a short interval. In FIG. 5b, vane 332 has moved downward relative to slotted structure 382, carrying bosses 314 and 316 with it. The upper side of boss 316c can be seen to have moved downward relative to gate 436b, but it remains within the purge chamber. The lower side of boss 314b is approaching the upper side of inserted gate 436d, and also is within the purge chamber. Boss 316b is receding from the lower side of inserted gate 436d. Light sensor 510 still receives light from source 512, and produces an output signal; the output signal from light sensor 516 is not used. A moment later, the lower edges of bosses 314b and 314c become contiguous with the upper sides of inserted gates 436d and 436b, respectively, as illustrated in FIG. 5c. At this time, proximity sensor 510 receives no light, and its output drops or makes a negative-going transition, indicating that a boss is adjacent gate 436d. Because the interval between bosses 314 equals the spacing between gates 436b and 436d, the sensing of boss 314b as contiguous to gate 436d corresponds to the position of boss 314c contiguous to gate 436a. The sensed boss positions cause the retracted and inserted positions of the gates 436a-436d to reverse, as illustrated in FIG. 5d. The control circuit, as described below, now ignores the signal from sensor 510, and responds only to a negative-going transition of the signal from sensor 516.
In FIG. 5d, gates 436a and 436c are inserted, and gates 436b and 436d are retracted. The motion of gate 436a has placed boss 314c within the purge chamber, and the motion of gate 434c places boss 314b without the purge chamber. A closed purge chamber continues to exist, but now between inserted gates 436a and 436c. In these positions of the gates, the bosses may continue to move downward relative to the gates. The gate position switching may result in a slight dilution of the inert gas in the purge chamber with oxygen-containing air, but the effect is slight, and the diluent is rapidly purged. Immediately after the gates switch position, boss 314b continues to prevent light from reaching sensor 510, but with the gates in the positions illustrated in FIG. 5d, its signal is ignored, and control is now established in sensor 516. FIG. 5e represents a position of vane 332 and bosses 324, 316 midway between the positions illustrated in FIG. 5d and FIG. 5f. In FIG. 5f, the lower edges of bosses 316c and 316d have become contiguous with the upper sides of inserted gates 436c and 436a, respectively, and the light to sensor 516 is cut off, resulting in a negative-going transition in the sensor signal. This transition indicates that the positions of the gates must once again be switched, in order to allow motion to continue. FIG. 5g represents a moment after that of FIG. 5f, and illustrates gates 436b and 436d switched to the inserted state, and gates 436a and 436c switched in the retracted state, thereby allowing the bosses to continue to move downward. In this state of the gates, the control circuit is no longer responsive to the signal from sensor 516, but responds instead to negative-going transitions of the signal from sensor 510. Sensor 510 is receiving light, and is producing an output signal. Bosses 314c and 316c are within the purge chamber. In FIG. 5h, the lower surfaces of bosses 316c and 316d have moved downward to a position which is contiguous with the upper surfaces of gates 436d and 436b, respectively. Light to sensor 510 is cut off, and the negative-going transition of its output indicates that the gate position must again be switched to allow motion to continue. FIG. 5i represents the gates in their switched positions, with gates 436a and 436c inserted, and with gates 436b and 436d retracted, to thereby include bosses 316d and 314c within the purge chamber, to exclude boss 316c from the purge chamber, and to make the control system sensitive to the signal from sensor 516. FIG. 5j represents the result of further motion of the bosses in a downward direction, bringing the lower surfaces of bosses 314d and 314c within the purge chamber into contiguous relation with the upper surfaces of gates 436c and 436a, respectively, thereby blocking light flow between source 518 to sensor 516, and causing a negative-going transition. The gates switch in response to the transition. At a time after the gate switching, the boss position, illustrated in FIG. 5k, displays the same state as that of FIG. 5a, except that a different set of the bosses, namely bosses 314c and 316d, is in position to continue through the purge chamber. The cycle of operation illustrated in FIGS. 5a-5k is repeated as many times as are necessary to cause all of the bosses to cycle through the purge chamber, so that welding can occur along the juncture of the two sheets of material along axis 36.
FIG. 6 is a simplified block diagram of a control circuit 600 which performs the control described in conjunction with FIGS. 5a-5k. In FIG. 6, sensor 510 couples its output signal over a signal path 610 to the normally-closed (NC) contacts of a relay 618, and sensor 516 couples its output signal over a path 616 to the normally-open (NO) contact. The movable element of relay 618 is coupled to the input port of a flip-flop (FF) 620, which switches state in response to a negative-going transition at its input port. The output of FF 620 is coupled back to control an actuating coil 624 of relay 620, and is also coupled by a path 622 to a noninverting driver 626 and an inverting driver 628. Driver 626 applies its drive signal by a path 630 to a solenoid (not illustrated) which actuates the cables attached to gates 436a and 436c. Inverting driver 628 drives applies its drive signal by a path 632 to a solenoid (not illustrated) which actuates cables attached to gates 436b and 436d.
FIGS. 7a, 7b, and 7c illustrate control waveforms associated with FIG. 6, in a time frame represented by FIGS. 5a-5k. In FIG. 7a, plot 610 represents the signal of sensor 510 on conductor 610 of FIG. 6, while plot 616 of FIG. 7b represents the signal of sensor 516 on conductor 616 of FIG. 6. More specifically, at the time of FIG. 5a, at the left of FIGS. 7a, 7b, and 7c, the signal on conductor 610 is logic high (or logic 1, or positive), and the signal on conductor 616 is logic low (logic 0, or negative). The state of FF 620 at that moment is such that its output is low, as indicated by plot 622 of FIG. 7c. With the output of FF 620 low, coil 624 is deenergized, and coil 618 is in the illustrated position, coupling the NC contact to the input port of the FF. Consequently, conductor 610 is coupled to the input port of the FF, and this relationship is indicated by the notation "610" adjacent plot 622 of FIG. 7c, in the time interval represented by 5a-5c,d. In the time interval represented by 5c,c to 5f,g of FIG. 7c, plot 622 is high, indicating that the output of FF 620 of FIG. 6 is logic high. With the FF output high, relay coil 624 is energized, and switches the movable contact of relay 618 to the NO contact, whereby the state of the FF becomes responsive to the signal on conductor 616, rather than to the signal from conductor 510, as suggested by the notation "616" adjacent plot 622 of FIG. 7c in the interval 5c,d to 5f,g. The state of FF 620 of FIG. 6 switches only in response to a negative-going transition in that one of the signals currently accessed by relay 618. More specifically, referring to FIGS. 7a, 7b, and 7c, the state of plot 622 (corresponding to the state of the FF) is responsive to signal 610 at times before time 5c,d, and switches at time 5c,d in response to the negative-going transition of plot 610 of FIG. 7a. At times after time 5c,d, the state of plot 622 is responsive to negative-going transitions in plot 616, which occurs at time 5f,g. After time 5f,g, the state of plot 622 is determined by a negative-going transition in plot 610, which makes such a transition at time 5h,i. Other aspects of the control should be obvious from the above description.
Other embodiments of the invention will be apparent to those skilled in the art. For example, the mandrel shaft may be vertical instead of horizontal. The tongues may be actuated by any type of motors, such as solenoids, pneumatic actuators, piezoelectric actuators, or the like. Any type of controller may be used to replace the controller of FIG. 6, so long as it provides the appropriate gate control. While light-actuated sensors are illustrated, the welding fumes may reduce the reliability of light transmission; mechanical switches may also be used. | An arrangement for butt-welding cylindrical sections of large, thin-wall tanks includes a rotatable mandrel with side-by-side sets of radial position adjusters. Each set of adjusters bears on one of the tank sections adjacent the seam, to prevent the sections from sagging out-of-round. The mandrel rotates relative to the welder, so that a continuous seam is formed. A purge chamber is fixed in position behind the seam at the weld head, and is flushed with inert gas. The purge chamber includes a two-sided structure which is contiguous with the cylindrical sections and a circumferential vane to form an open-ended tube-like structure, through which the radial position adjusters pass as the mandrel and cylindrical workpiece sections rotate. The tube-like structure is formed into a chamber by a plurality of movable gates which are controlled to maintain a seal while allowing adjusters to progress through the purge chamber. | 1 |
BACKGROUND OF THE INVENTION
In construction of microelectronic devices, it is well known that there is a constant pressure for reduction of device size and/or increase of device capability at a given scale.
In the actual construction of reduced scale devices, attention must be paid to higher precision in configuring the materials from which the device components are formed. Attention must also be paid to the interaction of the various materials used in device construction during the device manufacture process, during device testing, and during device operation. In this regard, finer sized device components are more sensitive to adverse materials interactions since the amount of material forming the component is smaller. For example, an interaction that might have only affected the border area of a large component would affect an entire component of smaller scale (e.g., where the scale of the smaller component is the same size as the border area of the larger component). Thus, reduction in component scale forces consideration of materials interaction problems which could have been viewed as non-critical for larger scale components.
In the context of devices such as deep trench capacitors in semiconductor substrates, the various materials used to form the components of the capacitor such as the capacitor plates (electrodes), the dielectric barrier between electrodes, oxide collar structures to prevent or minimize parasitic effects, surface or buried straps to provide contact between the capacitor and the other circuitry of the device, etc. For example, the electrode in the trench is typically a highly doped polycrystalline silicon (polysilicon) material, the buried or surface strap is typically an amorphous silicon, and the semiconductor substrate is a monocrystalline silicon. The successful functioning of the capacitor depends in part on the ability of these diverse materials to maintain their original or desirably modified character during manufacture/useful life of the device.
Unfortunately, the nature of these materials is such that unwanted interactions may occur unless otherwise prevented.
For example, a problem may be caused by the difference in crystallinity (or grain size) between the monocrystalline silicon substrate and the amorphous or polycrystalline silicon trench electrode material, especially where there is an intervening amorphous silicon material. In such configurations, the amorphous or polysilicon layer may template on the monocrystalline surface and recrystallize. Often, defects are created at the interface with the monocrystalline silicon during recrystallization which may propagate into the monocrystalline silicon. The occurrence of such defects is believed to adversely affect memory cell performance (the memory cell containing the capacitor). Specifically, the defects are believed to cause a lack of predictability of the charge retention time for the capacitor (so-called variable retention time). Such lack of predictability may limit the usefulness of the resulting device and/or the ability to maximize design performance.
Thus, there is a desire for improved capacitor structures which allow better control of materials interactions to enable construction of reliable reduced scale devices. It is also desired to meet these needs in an economical manner that minimizes or avoids compromise of other device or component properties.
SUMMARY OF THE INVENTION
The invention provides technology which enables reduced scale capacitor structures of improved reliability. More specifically, the invention enables these benefits by the creation and use of quantum conductive barrier layers between regions of differing degrees of crystallinity (or differing grain size).
In one aspect, the invention encompasses a deep trench capacitor in a monocrystalline semiconductor substrate, the capacitor (i) comprising a buried plate in the substrate about an exterior portion of a trench in the substrate, (ii) a node dielectric about at least a lower interior portion of the trench, (iii) an electrode in the trench, and (iv) a conductive strap extending away from the trench electrode, at least a portion of the conductive strap being electrically connected to the trench electrode and the monocrystalline substrate, the capacitor further comprising (v) a quantum conductive barrier layer between the monocrystalline substrate and the trench electrode.
In another aspect, the invention encompasses structures having regions of similar composition (e.g., differing only by amount of dopant or by dopant composition, or having essentially no difference in composition), but differing degrees of crystallinity (or differing average grain size), separated by a quantum conductive dielectric barrier layer. Preferably, a region on one side of the layer is amorphous or monocrystalline whereas a region on the other side of the layer is polycrystalline.
In another aspect, the invention encompasses methods of making trench capacitors containing quantum conductive layers, the methods comprising reacting a silicon surface with a nitrogen compound to form a thin silicon nitride compound layer.
In another aspect, the invention encompasses methods of making trench capacitors containing quantum conductive layers, the methods comprising depositing by chemical vapor deposition, physical vapor deposition or sputtering, a material layer which is sufficiently thin to be quantum conductive, the material being a dielectric in bulk form.
Preferred quantum conductive layers are silicon nitride compounds such as silicon nitride or silicon oxynitride.
These and other aspects of the invention are described in further detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross section of a structure having contiguous regions with a quantum conductive layer according to the invention.
FIG. 2 is a schematic plan view of a deep trench capacitor taken from trench top level with the buried strap exposed.
FIG. 3 is a schematic cross section of the deep trench capacitor structure of FIG. 2 at line A—A′.
FIG. 4 is a schematic cross section of the deep trench capacitor structure of FIG. 2 at line B—B′.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides quantum conductive barrier layers which are useful in control of stresses (e.g., associated with phase, lattice or thermal expansion mismatch, recrystallization or phase transformation) or other driving forces. The invention encompasses structures where such a quantum conductive layer is formed at an interface between two regions which form part or all of a contiguous body (e.g. a portion of a semiconductor device). The barrier layer may provide a benefit in one of the regions immediately adjacent to the interface and/or may provide a benefit in a contiguous region not directly located at the interface.
The invention provides trench capacitor structures containing one or more quantum conductive barriers at locations within the structure (i) between the strap and the monocrystalline substrate, and/or (ii) between the strap and the trench electrode.
The quantum conductive layers of the invention are very thin films of materials which in their bulk properties would be considered dielectrics (i.e., electrical insulators). In very thin layers, however, these materials become electrically conductive. Advantageously, these thin layers have the ability to prevent or reduce transmission of forces associated with recrystallization from one side of the layer to the other. The bulk resistivity (measured in a thick section at 25° C.) of the materials used to make up the quantum conductive layers of the invention is preferably at least about 10 6 ohm-m, more preferably at least about 10 8 ohm-m, most preferably at least about 10 11 ohm-m.
The quantum conductive layers preferably have a thickness of about 50 Å or less, more preferably about 5-30 Å, most preferably about 5-15 Å. The resulting films preferably have a film resistance of less than about 1 K-ohm-μm 2 , more preferably less than about 100 ohm-μm 2 . The series resistance introduced by the quantum conductive layer is equal to the film resistance (ohm-μm 2 ) divided by the cross sectional area (μm 2 ) of the quantum conductive layer normal to the direction of current.
The quantum conductive layers of the invention are preferably substantially uniform, however some variation in thickness may be permissible. Preferably, the layer thickness is kept in a range permitting the quantum conductive effect to take place for all points on the layer while performing the desired barrier function.
Preferred quantum conductive materials are inorganic oxides or nitrides, more preferably silicon nitride compounds selected from the group consisting of silicon nitride or silicon oxynitride. These compounds may be stoichiometric or non-stoichiometric. Alternatively, other ceramic materials such as, for example, alumina, germanium oxide, yttria-stabilized zirconia, or other forms of zirconia may also be used. The layer composition may be determined by secondary ion mass spectroscopy (SIMS) or other suitable technique.
In the broadest sense, the invention encompasses structures wherein the quantum conductive layer intervenes between two regions having differing degrees of crystallinity or differing average grain size. Turning to FIG. 1, the quantum conductive layer 10 , is preferably coextensive with at least one bordering region 12 . While the layer 10 is illustrated in FIG. 1 as being coextensive with one region on each side, it should be understood that the invention includes other structures where the layer is coextensive with a plurality of regions on one side of the layer. Also, the layer 10 may be coextensive with regions on both sides, as shown in FIG. 1, or just with the region(s) on one side. The quantum conductive layer 10 is preferably continuous.
In FIG. 1, the relative thickness of quantum conductive layer 10 has been exaggerated for ease of illustration. Structure 1 contains regions 12 and 16 on a first side 20 of quantum conductive layer 10 and regions 14 and 18 on the second side 30 of layer 10 . Preferably, the structure is such that at least one on first side 20 differs from at least one region on second side 30 either in (a) average grain size or (b) degree of crystallinity. The quantum conductive layers of the invention preferably act to control the effect of such differences between the regions on one side of the layer and the regions on the other side over the thermal history experienced by the structure .
Thus, the quantum conductive layers of the invention may be used to prevent or hinder forces associated with recrystallization of a region (e.g., region 12 ) from inducing changes in the crystallinity or crystal structure of regions 14 or 18 on the other side of layer 10 . For example, if region 12 were a polycrystalline silicon and region 18 were a monocrystalline silicon, quantum conductive layer 10 could be used to prevent or inhibit stresses associated with recrystallization of region 12 (e.g., as might occur in thermal processing of the overall structure 1 ) from being transmitted to monocrystalline region 18 where those stresses could cause an undesired propagation of defects in the monocrystalline structure.
While the invention is not limited to any specific compositional makeup for the regions of the structure bordering or contiguous with the quantum conductive layer, preferably, at least one of the regions directly contacting the quantum conductive layer is a silicon material selected from the group consisting of monocrystalline silicon, amorphous silicon or polycrystalline silicon. The silicon material may be doped or undoped. A typical example structure might have a polycrystalline silicon on one side of the layer and an amorphous or monocrystalline silicon region on the other side.
The quantum conductive layers of the invention are especially useful in trench capacitor structures. Examples of typical trench capacitor structures are shown in U.S. Pat. Nos. 5,283,453; 5,395,786; 5,434,109; 5,489,544; 5,512,767; 5,576,566; 5,656,535; and 5,677,219, the disclosures of which are incorporated herein by reference. The trench capacitor structures of the invention are not limited to any specific configuration.
FIG. 2 shows a schematic plan view of a typical trench capacitor structure 40 taken at the top of the trench in substrate 60 with the buried strap 56 exposed to reveal interface 58 between substrate 60 and strap 56 . Shallow trench isolation (STI) 66 surrounds the top area of capacitor 40 on three sides.
FIG. 3 shows a schematic side view of the trench capacitor of FIG. 2. A buried plate electrode 42 is located about the exterior of a lower portion of the trench 44 . A node dielectric 46 is present about the lower portion of the interior of trench 44 . About the upper interior of trench 44 is an oxide collar 48 . Trench 44 is filled with a conductive trench electrode material 50 . A conductive strap 56 resides over and is electrically connected to trench electrode 50 . Strap 56 thus provides electrical access to capacitor 40 . While FIGS. 2-4 show a buried strap, the invention is not limited to any specific strap configuration. For example, the invention is equally applicable in the context of surface straps, lip straps (e.g., as disclosed in U.S. patent application Ser. No. 09/105739, filed on Jun. 26, 1998, the disclosure of which is incorporated herein by reference) or other strap configurations.
The quantum conductive layers of the invention may be located at one or more locations within the trench capacitor structure as desired to prevent unwanted interactions . For example, a quantum conductive layer may be located at interface 58 between conductive strap 56 and substrate 60 . Such a quantum conductive layer would be useful in preventing or inhibiting undesired transmission of recrystallization forces from strap 56 and/or trench electrode 50 to substrate 60 . A quantum conductive layer may also be located at interface 62 between trench electrode 50 and strap 56 . Such a quantum conductive layer would also be useful in preventing or inhibiting undesired transmission of recrystallization forces from trench electrode 50 to strap 56 and substrate 60 . A side-effect of the use of the quantum conductive layers of the invention may be an inhibition of dopant diffusion from one side of the barrier layer to the other.
The invention encompasses trench capacitor structures where quantum conductive layers are located at one or more of the interfaces described above and/or at other locations within the capacitor structure as desired. Where the quantum conductive layer is formed by chemical vapor deposition, physical vapor deposition or sputtering, the layer may also optionally be present at the interface 64 between collar oxide 48 and strap 56 .
The composition and physical characteristics of the quantum conductive barriers used in the trench capacitors of the invention are preferably those described above with regard to general structures incorporating quantum conductive barriers. Advantageously, the quantum conductive layers can perform the desired barrier function without adversely affecting the electrical performance of the trench capacitor.
The invention is not limited to any specific material compositions for the various components of the trench capacitor. If desired, materials described in the art may be used. Thus, the trench electrode 50 would typically be made of a doped polycrystalline silicon or other suitably conductive material. Strap 56 would typically be made of amorphous silicon. Substrate 60 would typically be a monocrystalline semiconductor material (most typically silicon, lightly doped silicon or silicon having lightly doped bands). The buried plate 42 is typically a high dopant (e.g., arsenic) region within the substrate. The collar 48 and shallow trench isolation 66 are typically a silicon dioxide.
The use of alternative or modified materials may be enabled by the presence of the quantum conductive barriers of the invention. For example, trench electrode materials having very high dopant levels may be used (e.g., 5×10 18 −10 21 , more preferably 5×10 19 −10 20 dopant atoms per cm 3 ). Alternative trench electrode materials (e.g., silicides, conductive metal nitrides, etc.) may also be used in place of conventional doped polysilicon. The composition of the strap may also be altered in the presence of suitable quantum conductive barrier layers.
While the quantum conductive layers of the invention are especially useful in trench capacitor structures, it should be understood that the layers may be used in other integrated circuit components where very thin conductive barrier layers are desired to prevent transmission of recrystallization forces.
The quantum conductive layers of the invention may be made by various methods. The choice of method may depend on the composition of the surface on which the layer is to be formed and/or the desired quantum conductive layer composition.
Where the surface on which the layer is to be formed has a high silicon content (e.g., a conventional (doped or undoped) polycrystalline, amorphous or monocrystalline silicon), the quantum conductive layer is preferably formed by reacting a portion of the silicon at the immediate surface with a nitrogen-containing compound in the atmosphere contacting the surface. Preferred nitrogen-containing compounds are those which are easily handled in a gaseous state. Examples of preferred nitrogen compounds are selected from the group consisting of ammonia, NO, N 2 O or (under plasma conditions) monatomic nitrogen. Ammonia is the most preferred nitrogen compound. The atmosphere may also contain one or more diluent gases such as N 2 , helium or argon. The partial pressure of the nitrogen compound is preferably about 1-760 Torr, more preferably about 5-10 Torr. The reaction is typically facilitated by heating to a temperature of about 300-950° C., more preferably about 350-750° C. The reaction may be conducted until the desired layer thickness is formed. Preferably, the reaction is conducted for about 1-30 minutes, more preferably about 10-20 minutes. The reaction is typically self-limiting under these conditions.
If desired, the substrate may be precleaned by a chemical etch (e.g. HF solution and/or by a high temperature (e.g., about 900°-1000° C.) bake in a hydrogen atmospher (or other appropriate reducing atmosphere) to remove some or all of any pre-existing oxide surface layer. The techniques described in U.S. Pat. No. 5,194,397 may also be used to control the presence of oxide film. Other known methods for removal of residual films may also be used where appropriate.
Where an oxynitride quantum conductive layer is desired, the above nitrogen reaction process may be conducted with a substrate having a pre-existing very thin oxide layer. In such instances, the relative contents of oxygen and nitrogen in the quantum conductive layer can be controlled by the temperature and time of the nitrogen compound reaction, with higher temperatures and longer reaction times giving a more nitrogen-rich layer. Alternatively, if desired, oxynitride layers may be formed by introducing a very minor amount of oxygen into the nitrogen compound-containing atmosphere. In general, this method is generally less preferred since control of the oxygen content and/or layer thickness may be difficult.
Where reaction of the underlying surface is not desired or not practical, the quantum conductive layer may be formed by chemical vapor deposition, physical vapor deposition or sputtering. In such instances, the reactants for forming the quantum conductive layer may be those typically used to form thin film layers of the corresponding dielectric material, however the reaction conditions (time, temperature, pressure) and/or proportions of the reactants must be appropriately reduced to avoid deposition of an excessively thick film. See for example the process for forming germanium oxide thin films described in U.S. Pat. Nos. 5,648,861 and 5,051,786, the disclosures of which are incorporated herein by reference. Alternative methods for forming the desired thin films may be found in the “Handbook of Thin Film Technology” by Maissel & Glang, McGraw-Hill Book Co. (1970) and in similar treatises.
Trench capacitor structures containing the quantum conductive layers of the invention may be formed by inserting one of the above layer formation techniques at an appropriate point(s) in the overall process of capacitor manufacturing process. The overall trench capacitor manufacturing process used may be any of those known in the art such as those described in the patents mentioned above. Alternatively, other variations on trench capacitor manufacturing processes may also be used (e.g., processes involving formation of collar oxides by the LOCOS technique).
One method of forming a deep trench capacitor in a monocrystalline semiconductor substrate, with quantum conductive layers at both the interface of the strap and the substrate and the interface of the strap and the trench electrode, comprises:
(a) providing a monocrystalline semiconductor substrate having (i) a buried plate about an exterior portion of a trench in the substrate, (ii) a node dielectric about at least a lower interior portion of the trench, and (iii) an electrode in the trench,
(b) removing an upper portion of the electrode to provide space for a conductive strap, thereby exposing electrode and substrate surface,
(c) reacting the exposed surface of the electrode and the substrate about the space with a nitrogen compound to form a quantum conductive layer on the electrode and substrate surfaces, and
(d) filling the space over the quantum conductive layer with a conductive strap material.
Preferably, a collar oxide is provided about the upper interior portion of the trench in step (a). Shallow trench isolation would typically be formed after filling step (d) by etching to define a space for the isolation and filling that space with the desired shallow trench isolation material. Where formation of the quantum conductive layer(s) by reaction with the underlying surface is not desired, the quantum conductive layer may be formed by processes where chemical vapor deposition, physical vapor deposition, sputtering or other appropriate deposition technique is substituted for reacting step (c).
Where a quantum conductive layer is desired only at the interface of the strap and the trench electrode, a mask layer may be directionally deposited (e.g., by HDP deposition) over the layer formed in step (c) whereby the mask is thicker over the quantum conductive layer on the trench electrode surface. This mask may be removed from the quantum conductive layer on the substrate surface by isotropic etching (with partial reduction in thickness of the mask over the quantum conductive layer on the trench electrode surface. The quantum conductive layer on the substrate surface is then preferably removed by a selective isotropic etch to re-expose the substrate surface first exposed in step (b). The remaining mask over the quantum conductive layer on the trench electrode surface may then by removed by a further selective etch process. The process could then continue with filling step (d).
Alternatively, a deep trench capacitor according to the invention with a quantum conductive layer at the interface of the strap and the trench electrode may be formed by:
(a) providing a monocrystalline semiconductor substrate having (i) a buried plate in an exterior portion of trench in the substrate, (ii) a node dielectric about at least a lower interior portion of the trench, and (iii) an electrode in the trench,
(b) removing an upper portion of the electrode to provide space for a conductive strap, thereby exposing electrode and substrate surface,
(c) directionally depositing a thin dielectric material layer on the electrode surface,
(d) isotropically etching the thin dielectric material layer to remove any dielectric material deposited on the exposed substrate surface, thereby leaving a quantum conductive layer on the electrode surface only, and
(e) filling the space formed in step (b) with a conductive strap material.
Preferably, a collar oxide is provided about the upper interior portion of the trench in step (a). Shallow trench isolation would typically be formed after filling step (e) by etching to define a space for the isolation and filling that space with the desired shallow trench isolation material.
Where a surface strap is used, the above processes would be modified by eliminating steps for forming space for the buried strap. Where a trench capacitor formation process does not naturally provide the surface where a quantum barrier is desired, such a process can be modified by adding appropriate etch back, layer formation and fill steps, the etch and fill steps being selected from those known in the art for the specific materials involved. | Reduced scale structures of improved reliability and/or increased composition options are enabled by the creation and use of quantum conductive recrystallization barrier layers. The quantum conductive layers are preferably used in trench capacitors to act as recrystallization barriers. | 7 |
[0001] This document is protected by copyright except to the extent required by law to obtain and continue all available patent protection.
FIELD OF THE INVENTION
[0002] These inventions relate to the manufacture of high density computer systems using circuit board assemblies having very small pads (4-12 mil) for connection of flip chips and wire bond chips and/or very fine conductors for fan out from ball grid array modules, fine pitch (0.3-0.6 mm spacing) leaded components, flip chips, or wire bond chips that are attached to the circuit board assemblies. These inventions also relate to the manufacture of chip carriers in which flip chips and/or wire bond chips are connected to such very small pads and in which very fine conductors fan out from the chip connection pads to terminals for connection to circuit board assemblies. More specifically these inventions relate to an additive processes in which metal is fully electrolessly deposited onto substrates to form these very fine conductors and very small pads.
BACKGROUND
[0003] The following background is for convenience of those skilled in the art and for incorporating the listed citations by reference. The following background information is not an assertion that a search has been made, or that the following citations are analogous art, or that any of the following citations are pertinent or the only pertinent art that exists, or that any of the following citations are prior art.
[0004] The continued introduction of higher I/O and higher density surface mount components especially 0.3-0.6 mm gull wing leaded components, 40 mil ball grid array BGA modules, as well as the direct connection flip chips and wire bond chips to circuit boards, has resulted in a need for very fine conductors on organic circuit boards for fan out at these components. Also, the introduction of connecting flip chips and wire bond chips directly onto organic and metal circuit boards requires very small pads to be reliably formed. Furthermore, the introduction of chip carrier modules with organic and organic coated metal substrates has created a demand for very fine conductors and very small pads on organic surfaces.
[0005] Commonly, circuit boards include buried power planes (ground and other voltage levels) and signal planes on the surface. Such wiring layers are separated by layers of fiberglass filled epoxy (FR4 and G10). Connections between wiring layers are formed by drilling holes and plating the holes with copper to form plated through holes (PTHs). The power planes are pre-patterned with openings so that not all PTHs are required to connect to all the power planes. The PTHs and their surrounding lands require substantial surface area which can not be easily reduced because plating requires circulation of fluids in the holes.
[0006] More exotic circuit boards include multiple exterior signal wiring layers which may be separated by thin dielectric layers known as thin film. In order to provide higher density of conductors and pads, holes are formed through the thin dielectric layers by photolithography (producing photo vias) and plated to electrically connect between adjacent exterior wiring layers.
[0007] In subtractive processing, copper is plated over the entire surface of the substrate and onto the walls of through holes. Usually the copper is provided by electrolessly plating a thin strike layer, then electroplating a thick coating over the strike layer. Then the surface is coated with a photoresist that tents over the through holes, the photoresist is exposed and developed to provide a pattern that covers only the desired copper, and then the exposed copper is etched away to form an exterior wiring layer.
[0008] Another commonly used process is partial additive or semi-additive plating. In this process a very thin flash layer of copper is electrolessly deposited over the entire surface and in the through holes. Then the surface is coated with a photoresist which is exposed and developed to provide a pattern that covers the flash layer except the desired wiring pattern. Then copper is electroplated onto the exposed portion of the strike layer, a protective metal may be electroplated over the copper, the photoresist is stripped away, and the exposed flash layer is etched away.
[0009] In electroless plating the surface of a substrate is seeded by a catalyst material and then submerged in an electroless plating bath in which copper is chemically plated over the catalyst without providing any external electrical potentials. Deposition by electroless plating requires far more time than electroplating; thus, electroless plating is commonly used only for a thin layer called a flash or strike layer to allow subsequent electroplating.
[0010] For providing very fine conductors, full additive electroless copper plating is preferred in order to provides finer conductors and eliminate the risk of tenting failure causing etching away of copper plated in very small photo vias. In one method the surface is seeded, then a photoresist pattern is formed over the surface, a wiring layer is electrolessly formed at openings in the photoresist pattern, the photoresist is stripped and the remaining catalyst is removed. Alternately, the photoresist is deposited and patterned, the seeding layer is deposited over the exposed surface of the substrate and photoresist and then the photoresist is stripped to remove the undesired copper.
[0011] Those skilled in the art are directed to the following references. U.S. Pat. No. 4,908,087 to Murooka describes laminating to form a substrate structure. U.S. Pat. No. 3,163,588 to Shortt suggests stripable frisket, seeding and electroplating. U.S. Pat. No. 5,166,037 to Atkinson describes forming wiring layers on circuit board substrates with electroless plating. Printed Circuit Base by Marshall in IBM TDB Vol. 10, No. 5, October 1967, describes a sensitizing material. U.S. Pat. No. 4,590,539 to Sanjana discloses epoxies, fillers, curing agents, and catalysts. U.S. Pat. No. 4,217,182 to Cross, U.S. Pat. No. 4,378,384 to Murakami, U.S. Pat. No. 4,495,216 to Soerensen, U.S. Pat. No. 4,528,245 to Jobbins, U.S. Pat. No. 4,631,117 to Minten, U.S. Pat. No. 4,639,380 to Amelio, U.S. Pat. No. 4,684,550 to Milius, U.S. Pat. No. 4,601,847 to Barber, U.S. Pat. No. 4,820,388 to Kurze, U.S. Pat. No. 4,716,059 to Kim, and U.S. Pat. No. 5,250,105 to Gomes suggests treatment with surfactant before electroless plating. Also, Japanese patent JP 02-22477 to Takita suggests treating with surfactant prior to electroless plating. In the prior art surfactant treatment was followed by applications of catalyst, acid, or rinsing prior to electroless plating. U.S. Pat. No. 4,448,804 to Amelio, U.S. Pat. No. 4,964,948 to Reed, and U.S. Pat. No. 5,348,574 to Tokas suggests methods and materials for seeding a substrate prior to electroless plating. U.S. Pat. No. 5,200,026 to Okabe and U.S. Pat. No. 5,266,446 to Chang suggest processes for forming thin film structures on substrates. U.S. Pat. No. 4,897,338 to Spicciati, U.S. Pat. No. 4,940,651 to Brown, U.S. Pat. No. 5,070,002 to Leech, U.S. Pat. No. 5,300,402 to Card, U.S. Pat. No. 5,427,895 to Magnuson, and U.S. Pat. Nos. 5,026,624 and 5,439,779 to Day discuss photoresists.
[0012] The proceeding citations are hereby incorporated in whole by reference.
SUMMARY OF THE INVENTION
[0013] In the inventions of Applicants, a layer of fluid containing surfactant is applied over a catalyst layer on a substrate and the wet substrate is treated in an electroless bath. The level of surfactant in the bath is approximately ascertained by determining the surface tension of the electroless solution and surfactant is metered into the bath depending on the determination of surface tension.
[0014] The invention reduces the number of voids in a full electroless additive circuitization of small features which allows very fine line widths and very small pad sizes to be reliably formed. The invention allows flip chip and wire bond pads to be reliably formed on organic surfaced component substrates and also on organic surfaced circuit board substrates to greatly increase device density on the circuit board. The invention includes circuit boards made by the process of the invention in which surface mount components may be placed at a higher density to allow reduced signal flight times and faster circuit board speeds. Furthermore, the invention includes a computer system which operates faster due to the shorter signal flight times which result from the higher wiring densities of the invention.
[0015] Other features and advantages of this invention will become apparent from the following detailed description of the presently preferred embodiments of the invention illustrated by these drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1( a )- 1 ( g ) is a flow diagram illustrating a specific embodiment of the process of the invention.
[0017] [0017]FIG. 2( a )- 2 ( b ) is another flow diagram illustrating an alternative specific embodiment of the invention.
[0018] [0018]FIG. 3 schematically shows a portion of a circuit board assembly of the invention.
[0019] [0019]FIG. 4 schematically shows a portion of the manufacturing line for making another embodiment of the invention.
[0020] [0020]FIG. 5 schematically shows a computer system of the invention.
DETAILED DESCRIPTION
[0021] In steps 100 - 108 of FIG. 1( a ), a substrate structure is formed. The substrate may include ceramic plies (e.g. alumina, or berillia); or a metal plies (e.g. Cu, Al, Invar, Kovar, or Cu-Invar-Cu) covered with dielectric material (e.g. polyimide, or epoxy); or organic plies (e.g. epoxy) preferably filled with axially stiff fibers (fiberglass or polyaride fibers); or flexible plies of dielectric films (polyimide).
[0022] As shown in FIG. 1( a ) in step 100 , a B-stage epoxy sheet is made such as directing continuous woven fiberglass through a bath of epoxy precursor to form a sheet, and heating the sheet to partially cure the sheet to form a B-stage. Then in step 102 , the sheet is cut into plies. Copper foils are formed for wiring layers openings are punched in the foils for internal power planes which do not connect to vias which will be drilled through the openings. In step 106 , a stack of B-stage plies separated and covered with metal foils is formed and in step 108 , the stack is laminated with heat and pressure.
[0023] For example, in FIG. 3, circuit board substrate 302 includes two buried metal wiring layers 304 , 306 (power and ground planes) and three dielectric layers 308 , 310 , 312 . The dielectric layers may be ceramic or organic material or metal covered with dielectric. The substrate may have buried vias such as hole 316 which is an unplated hole filled with an electroconductive material such as epoxy filled with copper particles; or hole 318 which a plated through holes (PTH) filled with thermoconductive material such as epoxy filled with glass particles. Metal such as copper will be plated over the filled holes.
[0024] The metalized surface of the substrate structure may be vapor blasted and/or treated in a chloriting bath and/or micro-etched and/or treated with pumice to increase adhesion to a photoresist.
[0025] In step 110 of FIG. 1( b ), a layer of first photoresist is formed over the continuous layer of metal. Preferably a dry film photoresist about 0.1 to about 4.0 mils thick is used. Alternately a liquid photoresist may be applied for example by spinning. In step 112 , the photoresist is exposed to a pattern of electromagnetic radiation or a particle beam. The radiation may be produced in a pattern using a laser or a source of visible light, UV light, or X-ray may be directed through a mask to form a pattern. The type of radiation or particle beam depends on the availability of equipment and the chemistry of the photoresist. In step 114 , the photoresist is developed to form a first pattern of photoresist. Development usually includes rinsing with a solvent such as deionized water. The solvent is selected depending on the chemistry of the photoresist. The pattern covers portions of the metal layer which will form a wiring layer on the surface of the substrate. Other portions of the continuous metal layer are exposed and in step 116 , the exposed portions of the metal are etched away to form a first wiring layer (signal layer). For copper the preferred etchant is cupric chloride, but other etchants may be used. The first wiring layer 330 and 332 is shown in FIG. 3. In step 118 of FIG. 1( b ), the etchant is rinsed away, and in step 120 , the first photoresist is stripped away.
[0026] The photoresist may be a positive resist in which case the photoresist is exposed and the exposed portions become softened and are rinsed away to form the photoresist pattern and after etching the remaining photoresist is blanket exposed and rinsed away to strip the photoresist off the patterned wiring layer. In patterning negative photoresists, the exposed portions become hardened and the unexposed portions are rinsed away then after etching the pattern of the negative photoresist is removed using a solvent or enchant.
[0027] In step 122 , the substrate structure is rinsed with deionized water and in step 124 , the substrate is dried at an elevated temperature. The drying may include blowing heated air on the substrate in a convection oven.
[0028] The following steps 130 - 192 may be performed sequentially once or multiple times as desired, to provide one or more wiring layers on each of the surfaces of the substrate.
[0029] In step 130 in FIG. 1( c ), a layer of photoimagable dielectric is formed over the exterior wiring layer. Again, a dry film photoresist is preferred. The photoimagable dielectric can be the same material or a different material than the first photoresist and either a positive or negative photoresist.
[0030] In step 132 , the photoimagable dielectric is exposed as described above, and in step 134 , is developed as described above to form a pattern of photoimagable dielectric. Preferably as shown in FIG. 3, the pattern of photoresist layers 336 , 338 consist only of via holes such as at 340 , 342 that extend through the photoresist over pads or conductors of the first wiring layer. In step 136 , the photoimagable dielectric is treated to make it permanent for example by baking a positive photoresist so that it is not effected by subsequent exposure to light and subsequent plating, etching, developing steps do not affect the photoimagable dielectric. This step may not be required for some negative photoresists. In step 138 , the structure is rinsed in deionized water and in step 140 , is dried at elevated temperature as discussed above.
[0031] In step 150 in FIG. 1( d ), a third layer of photoresist is formed over the permanent photoimagable dielectric, and in step 152 , the third photoresist is exposed as described above. In step 154 , the third photoresist is developed to form a pattern of third photoresist.
[0032] The following steps 156 and 158 may be performed for any layer for electrical connection between layers. For buried layers preferably the holes are filled with electroconductive organic material or are plated and filled with organic material which may be thermoconductive as described above. The steps 156 , 158 are also performed when forming the last wiring layer on the surfaces of the substrate when PIH components are to be connected. For example in FIG. 3, three external wiring layers are provided and PTH 344 is provided when forming the final wiring layer for interconnection and/or PIH component connection.
[0033] In step 156 of FIG. 1( d ), holes are formed through the substrate to provide PTHs for PIH components and/or wiring layer interconnection. The holes may be formed by laser drilling, punching, or by mechanical drilling using a drill bit. In step 158 , the holes are treated to remove debris and improve electrical connection. For holes mechanically formed using a drill bit, the holes should be deburred and chemically cleaned in step 158 , to remove smear from internal wiring layers for electrical connection thereto. In step 160 , the substrate is rinsed in deionized water.
[0034] In steps 170 - 192 of FIG. 1( e ), the surface of the substrate including the photoimagable dielectric as well as the walls of the photo-vias and any holes for PIH components, are subjected to an electroless plating process. In step 170 , the surfaces are cleaned and micro-etched in an acid bath and in step 172 , the surfaces are rinsed in deionized water. In step 174 , the surfaces are seeded for electroless metal plating and in step 176 , the seeded layer is rinsed with deionized water. In step 178 , a solution of surfactant is deposited on the surfaces and then the surfaces are immediately exposed to an electroless plating solution. Applicants have discovered that coating the surfaces of the substrate with surfactant solution immediately prior to electroless plating greatly reduces the number of voids in very fine circuit lines and very small pads formed by full additive electroless plating. A residual amount of surfactant on the substrate appears to be more effective than just providing surfactant in the plating bath. However, the surface tension in the plating bath also contributes to reducing the voids as discussed below. In step 180 , the surface tension of the electroless plating solution is determined and in step 182 , the metering of surfactant into the plating bath is regulated depending on the determination of surface tension. Applicants have discovered that regulating the surface tension is critical for reliably forming void free very fine lines and very small pads during full additive electroless plating. The surface tension is controlled by adjusting the level of surfactant in the plating solution. The expense of determining the level of surfactant may be greatly reduced by measuring the surface tension (rather than the level of surfactant). Since the voids seem to be related to air bubbles trapped on the surface and in the holes and vias, the level of surface tension is the critical variable that need to be kept constant.
[0035] In step 184 , a full thickness of metal is formed on the seeded surfaces by electroless plating. Preferably the coating is copper with a thickness of 0.2 to 4 oz of Cu per square foot, more preferably about 1 oz (0.5-2 oz) per square foot. Preferably the copper is at least 1 mil thick in any plated through holes. Finally in step 186 , the layer of third photoresist is stripped to remove plated metal covering the third photoresist and form a second wiring layer. Alternatively, the surface of the substrate may be flattened using chemical-mechanical polishing to remove any metal plating the third photoresist to form the second wiring layer, and the third photoresist layer may be treated as described above to make it permanent.
[0036] In step 188 , the substrate is exposed to acid to clean the substrate and micro-etch the surface for adhesion to the next layer of photoresist or solder resist.
[0037] In FIG. 3, three external wiring layers are shown. This structure is produced by performing steps 130 - 192 twice in succession.
[0038] In steps 200 - 212 of FIG. 1( f ), surface mount technology (SMT) components (leaded and BGA), flip chips, and/or wire bond chips are connected to the substrate to form a circuit board assembly or a chip carrier module. In step 200 , a solder resist is applied to the surfaces of the circuit board to prevent solder from wicking down conductors away from SMT connection pads and any lands for PIH connection. The solder resist may be a photoimagable dielectric or a common solder resist. The solder resist may be applied by roll coating, curtain coating, print screening, or lamination of a dry layer onto the surface. Then in step 202 , windows may be formed photolithographically in the solder resist over pads for surface mount components and lands for PIH components. For screened solder resist larger windows may be formed during screening onto the wiring layer and smaller windows formed by photo processing if required. In FIG. 3, windows 350 , 351 , 352 expose pads 354 , 355 , 356 respectively for flip chip 358 , leaded component 359 , and BGA component 360 respectively. Pads 354 are spaced 5 to 15 mils apart for connection of the flip chip or wire bond chip, pads 355 are spaced at 10 to 30 mils for leaded components, and pads 356 are spaced at 30 to 50 mils for connection of a BGA module.
[0039] The circuitized substrate of the invention has improved wirability due to reduced via diameters and reduced land diameters of the first and second wiring layer. In step 204 of FIG. 1( f ), joining material 370 (FIG. 3) is screened into the windows onto the pads for surface mount connection. Alternately the joining material may be screened onto the component terminals or the pads or terminals may otherwise be coated with joining material. The joining material may be an ECA with conductive particles or a TLP system or a solder paste or a solder alloy may be provided on the pads or terminals and a flux applied to the pads and/or terminals for soldered connection). Solder paste consists of liquid flux and metal particles which melt during reflow heating to form molten solder alloy such as approximately eutectic Pb/Sn solder (e.g. Pb and 30-80% Sn preferably 55-70% Sn). In step 206 , the terminals (balls, leads, pads) of surface mount components are positioned at the pads (close enough for reflowed connection between the pads and the terminals). In step 208 , the solder material is cured. For solder paste the curing includes heating the paste above the melting temperature of the solder alloy. In step 210 , the joining material is cooled to form solid joints between the terminals and pads.
[0040] When PIH components are required then steps 220 - 228 of FIG. 1( j ) are also performed. In step 220 , PIH components are placed on the substrate with pins or leads of the component in PTHs. In step 222 , flux is applied into the holes to provide a more solder wettable metal surface. In step 124 , the substrate is moved over a wave or fountain of solder in contact with the molten solder which wets to lands on the bottom of the board and fills the PTHs by capillary action (surface tension). Then in step 226 , the solder is cooled to form solid joints of solder alloy.
[0041] Alternatively, solder paste may be applied to the top surface of the substrate over the lands around the PTHs and the pins of the components inserted through the paste deposits. Then during reflow for the surface mount components the solder paste reflows to form solder alloy which fills up the respective PTH.
[0042] Steps 250 - 284 in FIGS. 2 ( a )- 29 ( b ), illustrate an alternative embodiment for the steps 170 - 192 of FIG. 1( e ) of the process of the invention for forming additional wiring layers such as a second wiring layer on each side of the substrate. FIG. 1( e ) illustrates an additive process and FIGS. 2 ( a )- 2 ( b ) illustrate a subtractive embodiment. Steps 250 - 264 in FIG. 2( a ) are similar to steps 156 - 184 and the above discussion thereof applies. Also, steps 270 - 286 are similar to steps 110 - 124 in FIG. 1( b ) and the above discussion thereof applies.
[0043] [0043]FIG. 4( a )-FIG. 4( d ), illustrate a manufacturing line for another embodiment of the invention. Some process steps such as optional hole drilling for plated through holes discussed above, have intentionally been left out of the following process described for illustrative purposes. Substrate 400 is provided from roll 402 and first photoimagable dielectric 404 , 406 from roles 408 , 410 is laminated with heat and pressure to substrate 400 in oven 412 by heated rollers 414 , 416 to form structure 418 . The substrate in this embodiment is a patterned copper film or an organic substrate with surface wiring layers. Those skilled in the art will know how to modify this embodiment for substrates whith dielectric surfaces.
[0044] A source of light 420 is culminated by lens 422 and patterned by mask 424 to expose a part of the photoimagable dielectric 404 , 406 . At station 430 , development fluid 432 is delivered by pump 434 to nozzle 436 and sprayed onto the substrate structure 418 to remove the exposed portion of the photoimagable dielectric which is preferably via holes. At station 440 the structure is micro etched by acid 442 , and the structure is rinsed in station 450 . The structure is baked in convection oven 452 until dry. The substrate may be rolled and stored at this stage or the process may continue immediately.
[0045] In FIG. 4( b ), in oven 454 second layers of photoimagable dielectric 456 , 458 are laminated to each side of the structure 418 with heat and pressure using rolls 460 , 462 to form structure 464 . After each lamination step in this process the substrate may be rolled and stored for later processing or the process may continue immediately. In station 470 lasers 472 , 474 pattern the second layers of photoimagable dielectric. In station 472 which is similar to station 430 , the second layers of photoimagable dielectric are developed. In station 474 structure 464 is micro-etched and in station 476 the substrate structure is rinsed.
[0046] In FIG. 4( c ), in station 478 the surface of the substrate is catalyzed and in station 480 the catalyzed surface is rinsed. In station 482 solution with surfactant is deposited on the substrate and in station 484 copper is electrolessly plated on structure 464 . In station 484 meter 486 determines the surface tension of plating solution 488 and transmits a value signal to computer system 490 . The computer controls a valve 492 that regulates the flow of surfactant from source 494 into the plating solution. In station 496 the surface of the substrate structure is planerized to form an external wiring pattern and in station 498 the structure is rinsed, and in station 499 the structure is dried. Again, at this stage the substrate structure may be rolled up for later processing or processing may continue.
[0047] In FIG. 4( d ), in oven 500 layers of solder resist 502 , 504 are laminated to each side of the structure 464 with heat and pressure using hot rolls 506 , 508 to form structure 510 . Then mask 512 of a non solder wettable material is moved with the structure and solder 514 is injected into openings in the mask and onto the structure at pads for surface mount connection. The solder is cooled and the mask is separated from the structure. At station 520 components are placed on structure 510 with leads on solder on corresponding pads of the external wiring layer, and in oven 522 the solder is reflowed (heated to its liquidous temperature) to connect the components to the substrate. Finally in station 524 knives cut the substrate structure into individual circuit board assemblies or chip carrier assemblies 526 .
[0048] [0048]FIG. 5 illustrates computer system 600 of the invention with increased performance due to higher component densities and resulting shorter signal flight time. The system includes an enclosure 602 in which a power supply 604 and one or more circuit boards 606 , 608 , 610 are mounted. The circuit boards communicate through interconnect bus 612 . The circuit boards include multiple components including direct connect flip chips pin grid array module 614 , thin small outline package 616 , ceramic J-lead component 618 , ball grid array module 620 , quad flat pack 622 , flip chip 624 , column grid array module 626 . The components one or more CPUs, dynamic RAMs, static RAMs, and I/O processors connected to ports 626 , 628 for communication with computer peripherals such as keyboards, mice, displays, printers, modems, networks. Although the invention has been described specifically in terms of preferred embodiments, such embodiments are provided only as examples. Those skilled in the art are expected to make numerous changes and substitutions, including those discussed above, in arriving at their own embodiments, without departing from the spirit of the present invention. Thus, the scope of the invention is only limited by the following claims. | The present invention provides a method for electrolessly depositing metal onto a substrate, comprising: exposing a surface of the substrate to a first solution including a surfactant; and exposing the surface, having residual surfactant from the first solution thereon, to a second solution including ions of an electroconductive metal element for plating the surface with the electroconductive metal while exposed to the second solution; wherein the surface is exposed to the first solution immediately prior to exposing the surface to the second solution. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a purge control device for use in an internal combustion engine.
2. Description of the Related Art
It is well known in this field to fit a charcoal canister to an internal combustion engine as a part of a fuel vapor control system for the engine. The charcoal canister usually comprises a fuel vapor inlet connected to a fuel tank, a fuel vapor outlet connected to an intake passage in the vicinity of a throttle valve, and an air inlet connected to the intake passage upstream of the throttle valve and downstream of an air flow meter. In this system when the throttle valve is open, the fuel vapor outlet of the charcoal canister is connected to the intake passage downstream of the throttle valve, and consequently, a part of the air metered by the air flow meter at this time is fed into the charcoal canister, and the fuel component absorbed in activated carbons in the charcoal canister is desorbed by this air. The thus desorbed fuel component is then fed into the intake passage.
In this engine, however, when the temperature of exhaust gases fed into a catalyst of the exhaust emission system or the temperature of the catalyst bed is within a predetermined range, and when an air-fuel mixture fed into the engine cylinders temporarily becomes rich due to the supply of the purge gas purged from the charcoal canister, hydrogen sulfide (herein-after referred to as H 2 S) is produced, and therefore, a problem arises in that an unpleasant and toxic odor is produced.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a purge control device capable of reducing unpleasant odors emitted from the catalyst.
Therefore, according to the present invention, there is provided an internal combustion engine having an intake passage and an exhaust passage, comprising: a charcoal canister for storing fuel vapor therein; a catalyst arranged in the exhaust passage; a determining means for determining whether or not the catalyst is producing hydrogen sulfide and a control means for controlling the amount of purge gas purged from the charcoal canister and fed to the intake passage in accordance with a determination by the determining means, to reduce the amount of purge gas when the catalyst is producing hydrogen sulfide.
The present invention may be more fully understood from the description of preferred embodiments of the invention set forth below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematically illustrated view of an engine;
FIG. 2 is a block diagram of an electronic control unit;
FIG. 3 is a flow chart for executing the control of the control valve;
FIG. 4 is a flow chart for executing the calculation of the injection time TAU; and
FIG. 5 is a operational diagram of an embodiment of this invention, compared with the related art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a surge tank 2 is connected to an air cleaner (not shown) via an intake duct 4 and an air flow meter 6, a throttle valve 8, which is connected to an acceleration pedal (not shown), is arranged in the intake duct 4, and a throttle sensor 10 for detecting a degree of opening of a throttle valve 8 is connected to the throttle valve 8. A fuel injector 12 is attached to an intake manifold 14 and injects fuel toward an intake port of an engine 16, and a oxygen concentration detecting sensor (hereinafter referred to as an O 2 sensor) 18 for detecting an air-fuel ratio is arranged in an exhaust manifold 20. A three-way catalyst 24 is disposed in an exhaust pipe 22 and a bed temperature sensor 26 for detecting a temperature of a bed of the three-way catalyst 24 is arranged in the three-way catalyst 24. A distributor 28 having a distribution shaft (not shown) rotated in accordance with the engine speed, is provided with a crank angle sensor 30 which generates pulses by which the engine speed is determined. A cooling water temperature sensor 32 for detecting a cooling water temperature of the engine 16 is arranged in a cylinder block.
Further, a fuel tank 34 is connected to a charcoal canister 38 via a vapor conduit 36, and fuel vapor produced in the fuel tank 34 is absorbed by activated carbon 39 in the canister 38. In addition, the canister 38 is connected to a purge control valve 42 via a first purge conduit 40, and the purge control valve 42 is connected to the intake duct 4 at a purge port 46 via a second purge conduit 44. This purge port 46 is open to the intake duct 4 upstream of the throttle valve 8 when the throttle valve 8 is in the idling position, and is open to the intake duct 4 downstream of the throttle valve 8 when the throttle valve 8 is open. The control valve 42 is connected to a connecting portion 47 of the second purge conduit 44 by a bypass conduit 48 having a throat portion 50 provided therein. A sum of a flow resistance of the bypass conduit 48 and the second purge conduit 44 from the connecting portion 47 to the purge port 46 is about three times as large as a flow resistance of the second purge conduit 44 from the control valve 42 to the purge port 46.
The control valve 42 can assume three operating positions. When in the first operating position, the control valve 42 communicates the first purge conduit 40 with the second purge conduit 44, and shuts off the bypass conduit 48, and therefore, when the throttle valve 8 is open, the fuel component absorbed in the activated carbon 39 is desorbed therefrom and fuel vapor is fed into the intake duct 4 from the second purge conduit 44. When in the second operating position, the control valve 42 communicates the first purge conduit 40 with the bypass conduit 48, and blocks the direct communication between the first and second purge conduits 40 and 44, and therefore, when the throttle valve 8 is open, only a small amount of the fuel vapor from the canister 38 is fed into the intake duct 4 via the bypass conduit 48. In this case, the amount of purge gas fed into the intake duct 4 is about one third of the amount fed when the control valve 42 is in the first operating position. When in the third operating position, the control valve 42 closes the first purge conduit 40, and therefore, fuel vapor from the charcoal canister 38 is not fed into the intake duct 4.
Further, an actual injection time TAU of the fuel injector 12 is calculated in an electronic control unit 60, from the following equation.
TAU=TP.FAF.FOTP
Where
TP: a basic injection time
FAF: a feedback correction coefficient
FOTP: an acceleration increasing correction coefficient
In this equation, the basic injection time TP is calculated from the engine speed and the amount of air fed into the engine cylinders. The feedback correction coefficient FAF is controlled based on the output signal of the O 2 sensor 18, so that an air-fuel ratio becomes equal to the stoichiometric air-fuel ratio. The acceleration increasing correction coefficient FOTP is described hereinafter.
Referring to FIG. 2, the electronic control unit 60 is constructed as a digital computer and comprises a ROM (read only memory) 64, a RAM (random access memory) 66, a CPU (microprocessor, etc.) 68, an input port 70, and an output port 72. The ROM 64, the RAM 66, the CPU 68, the input port 70, and the output port 72 are interconnected via a bidirectional bus 62. The input port 70 is connected to the air flow meter 6, the throttle sensor 10, the O 2 sensor 18, the catalyst bed temperature sensor 26, and the cooling water temperature sensor 32 via corresponding AD converters 74 .The input port 70 is connected directly to the crank angle sensor 30.
The output port 76 is connected to the fuel injector 12 and the control valve 42 via corresponding drive circuits 76.
FIG. 3 illustrates a flow chart for executing the control of the control valve 42 to control the amount of purge gas purged from the charcoal canister 38. The routine illustrated in FIG. 3 is processed by sequential interruptions executed at 50 msec. intervals.
In step S1, it is determined whether or not the cooling water temperature TW is equal to or higher than 60° C. If TW<60° C., the routine goes to step S2, and the control valve 42 is placed in the third operating position so that fuel vapor absorbed by the activated carbon 39 is not fed into the intake duct 4. Therefore, when the engine is cold, the engine operating state can be stabilized. If TW≧60° C., the routine goes to step S3, and it is determined whether or not the temperature TB of the catalyst bed of the three-way catalyst 24 is within a predetermined temperature range, for example, higher than 600° C. and lower than 700° C. If TB≦600° C. or TB≧700° C., as H 2 S cannot be produced, the routine goes to step S4, and the control valve 42 is placed in the first operating position, whereby the first purge conduit 40 is communicated with the second purge conduit 44. Therefore, when the throttle valve 8 is open, the normal supply of the purge gas is started and fuel vapor absorbed by the activated carbon 39 is fed into the intake duct 4. If TB>700< C., the routine goes to step S5, and it is determined whether or not a flag F is set. The flag F is set, when an injection time of the fuel injector 12 is made longer to make an air-fuel mixture fed into cylinders rich, i.e., the flag F is controlled by, for example, the acceleration increasing correction coefficient FOTP described hereinafter. If the flag F is not set, the routine goes to step S6, and the control valve 42 is placed in the second operating position, whereby the first purge conduit 40 is communicated with the second purge conduit 44 via the bypass conduit 48. Therefore, in this case, since the amount of the purge gas purged from the charcoal canister 38 is about one third of the amount of purge gas purged when the control valve 42 is in the first operating position, an air-fuel mixture fed into the engine cylinders does not become rich. Consequently, even if the temperature TB of the bed of the three-way catalyst 24 is higher than 600° C. and lower than 700° C., H 2 S is not produced by the three-way catalyst 24. In step S5, if the flag F is set, the routine goes to step S2, and a purge of the charcoal canister is not carried out. Accordingly, since the air-fuel mixture does not become rich, H 2 S is not produced.
Table 1 shows an example of a relationship among an amount of purge gas purged from the charcoal canister 38, the temperature TB of the bed of the three-way catalyst 24, and the flag F. When TB≦600° C. or TB≧700° C., a usual amount of purge gas is purged from the charcoal canister 38, defined as 10 in the Table. When TB is higher than 600° C. and lower than 700° C., and the flag F has been reset, the amount of gas is equal to 3. When the flag F has been set, the amount of purge gas is equal to 0, i.e., the supply of purge gas is stopped.
TABLE 1______________________________________TBF TB ≦ 600° C. 600° C. < TB < 700° C. TB ≧ 700° C.______________________________________RESET 10 3 10SET 10 0 10______________________________________
In addition, as shown in Table 2, when the set flag F is set, the amount of purge gas may be stepwise changed into several separate amounts of purge gas in accordance with the temperature TB.
TABLE 2______________________________________TBF TB ≦ 600° C. 600° C. < TB < 700° C. TB ≧ 700° C.______________________________________RESET 10 3 10SET 8 0 6______________________________________
FIG. 4 illustrates a routine for the calculation of an actual injection time TAU. The routine illustrated in FIG. 4 is processed at a predetermined crank angle.
Referring to FIG. 4, in step S10, it is determined whether or not the cooling water temperature TW output by the cooling water temperature sensor 32 is equal to or higher than 35° C. If TW<35° C., the routine go step S11, and it is determined whether or not a degree TA of opening of the throttle valve 8 is larger than 70% of the fully open position, on the basis of signals output by the throttle sensor 10. In step S10, if TW≧35° C., the routine goes to step S12, and it is determined whether or not the engine is operating in an idling state, on the basis of signals output by the throttle sensor 10. If the engine is operating in an idling state, the routine goes to step S11. In step S11, if TA≦=70%, the routine goes to step S13, and 1.0 is memorized as FOTP. In step S14, the flag F is reset, and in step S15, 1.0 is memorized as a feed back correction coefficient FAF. In step S16, the basic injection time TP is calculated from the engine speed N and the amount of the air Q fed into the engine cylinders, on the basis of signals output by the crankangle sensor 30 and the air flow meter 6. In this step, K indicates a constant value, and Q/N corresponds to an engine load. Then, in step S17, TAU is calculated. In this case, TAU is calculated from the following equation.
TAU=TP
In step S11, if TA>70%, the routine goes to step S18, and 1.2 is memorized as FOTP. Then, in step S19, the flag F is set, and in step S15, 1.0 is memorized as FAF. In this case, TAU is calculated from the following equation.
TAU=TP.FOTP
and therefore, TP is made longer by FOTP to make an air-fuel mixture fed into cylinders rich.
In step S12, if the engine is not operating in an idling state, the routine goes to step S20, and it is determined whether or not a degree TA of opening of the throttle valve 8 is equal to or smaller than 70% of the fully open position. If TA>70%, the routine goes to step S18, but if TA≦70%, the routine goes to step S21, and 1.0 is memorized as FOTP. Then, in step S22, the flag F is reset, in step S23, FAF is calculated, and then the routine goes to step S16. In this case, a feed back control of the air-fuel ratio is carried out, and TAU is calculated from the following equation.
TAU=TP.FAF
FIG. 5 shows an operational diagram of this embodiment in comparison with a conventional system. In FIG. 5, "PURGE ON" means that purge gas purged from the charcoal canister 38 is fed into the intake duct 4, and "PURGE OFF" means that the first purge conduit 40 is closed by the control valve 42 and a purge is not carried out. The engine is operated to a point T 1 , and then stopped. In a period from T 1 to T 2 , fuel is supplied to the fuel tank 34, and at T 2 , the engine is restarted and TB starts to rise. Since a large amount of fuel component is absorbed by the activated carbon 39 in the charcoal canister 38, when the engine is operated again, a large amount of fuel vapor purged from the charcoal canister 38 is fed into the intake duct 4, and thus an air-fuel mixture fed into the engine cylinders becomes extremely rich. In a period from T 3 to T 4 , TB is in the temperature range between t 1 and t 2 . When the temperature TB of the bed of the three-way catalyst 24 is higher than t 1 and lower than t 2 , H 2 S might be produced. In the related art, in the period from T 3 to T 4 , since a purge is carried out, i.e., purge gas is fed into the intake duct 4, an air-fuel mixture fed into the engine cylinders becomes extremely rich, and therefore, H 2 S is produced. In this embodiment, in the period from T 3 to T 4 , since the purge is not carried out, i.e., purge gas is not fed into the intake duct 4 (when flag F is set), an air-fuel mixture fed into the engine cylinders does not become rich, and consequently H 2 S is not produced. Namely, after T 4 , since TB is higher than t 2 , H 2 S is not produced even when purge gas is fed into the intake duct 4.
While the invention has been described with reference to specific embodiments chosen for purposes of illustration, it should be apparent that numerous modifications can be made without departing from the basic concept and scope of the invention. | A purge control device comprising a determining unit and a control unit, whereby, when the determining unit determines that a catalyst arranged in a exhaust passage is in a state wherein hydrogen sulfide can be produced, the control unit reduces the amount of the purge gas purged from a charcoal canister and fed into an intake passage. | 8 |
This application is a continuation of U.S. patent application Ser. No. 13/669,809, filed on Nov. 6, 2012 (now U.S. Pat. No. 8,561,717), which in turn is a divisional of U.S. patent application Ser. No. 11/592,603, filed on Nov. 3, 2006 (now U.S. Pat. No. 8,322,456), which claims the benefit of provisional U.S. Patent Application No. 60/733,546, filed on Nov. 4, 2005, the disclosure of each of which are hereby totally incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to an electric hand tool and more particularly to an articulating power hand tool.
BACKGROUND
Power tools including battery operated tools are well-known. These tools typically include an electric motor having an output shaft that is coupled to a spindle for holding a tool. The tool may be a drill bit, sanding disc, a de-burring implement, or the like. The power source may be a battery source such as a Ni-Cad or other rechargeable battery that may be de-coupled from the tool to charge the battery and coupled to the tool to provide power.
The power source is coupled to the electric motor through a power switch. The switch includes input electrical contacts for coupling the switch to the power source. Within the switch housing, a moveable member, sometimes called a switch, is coupled to the input electrical contacts and to a wiper of a potentiometer. As the moveable member is pressed against the biasing component of the switch, it causes the input electrical contacts to close and provide current to one terminal of the electric motor and to the wiper of the potentiometer. The moveable member is biased so that the biasing force returns the moveable member to the position where the input electrical contacts are open when the moveable member is released. The current is coupled to a timing signal generator, such as a “555” circuit, through the potentiometer. As the member or trigger continues to be pulled against the biasing force so that the wiper reduces the resistance of the potentiometer from an open circuit to a low resistance or short circuit condition, the level of the current supplied to the timing signal generator increases.
The output of the timing signal generator is coupled to the gate of a solid state device, such as a MOSFET. The source and drain of the solid state device are coupled between a second terminal of the electric motor and electrical ground. In response to the timing signal turning the solid state device on and off, the motor is selectively coupled to electrical ground through the solid state device. Thus, as the timing signal enables the solid state device to couple the motor to electrical ground for longer and longer intervals, the current flows through the motor for longer intervals. The longer the motor is coupled to power, the faster the electric motor rotates the output shaft of the motor. Consequently, the tool operator is able to vary the speed of the motor and, correspondingly, the rotational speed of the tool in the spindle by manipulating the trigger for the power switch.
The timing signal generated by the timing circuit selectively couples the motor to the power source because it alternates between a logically on-state and a logically off-state. During the logically off-state, the motor is no longer coupled to the power source. The windings in the motor, however, still have current in them. To provide a path for this current, a freewheeling diode is provided across the terminals of the motor.
The trigger of the power switch is also coupled to two sets of contacts. One of these contact sets is called the bypass contact set. When the trigger reaches the stop position of its travel against the biasing component, it causes the bypass contacts to close. The closing of the bypass contacts causes the current through the motor to bypass the solid state device and be shunted to electrical ground. This action enables the motor to remain continuously coupled to the power source and reach its maximum speed.
The other set of electrical contacts controlled by the switch trigger are the brake contacts. These contacts are closed when the trigger is at the fully biased off position. As the trigger is moved against the biasing force, the brake contacts open. The brake contacts couple one terminal of the electric motor to the other terminal of the motor. In response to the trigger being released from a position that enables power to be supplied to the motor, the brake contacts close to provide a current path through the motor for dynamic braking of the motor. This enables the motor to stop more quickly than if the motor simply coasted to a stop under the effects of friction.
While the power switch described above is effective for tool speed control, it suffers from some limitations. Known power switches are limited because of the effect of carrying the battery current through the switch. When the battery current is first applied to the contacts, the current level may be sufficient to cause arcing. Arcing may cause the contacts to become pitted or otherwise damaged. Additionally, large currents also tend to heat the components within the switch. Consequently, the switch may require a heat sink or a larger volume to dissipate heat within the switch. The larger size of the housing for the switch may also impact the design of the tool housing to accommodate the switch geometry. Another factor affecting the geometry or size of the switch housing is the potentiometer that generates the variable speed signal. Typically, the distance traveled by the wiper of the potentiometer is approximately the same as the distance traveled by the trigger. In many cases, this distance is approximately 7 mm and this distance must be accommodated by the potentiometer and the housing in which the potentiometer is mounted.
The direction of motor rotation depends upon whether the battery current flows through the motor from the first terminal to the second terminal or vice versa. Because bidirectional rotation of battery operated tools is desirable, most tools are provided with a two position switch that determines the direction of battery current through the electric motor. In some previously known switches for battery operated tools, this two position switch is incorporated in its own housing that is mounted to the switch housing. The additional two position switch housing may exacerbate the space issues already noted. In other known switches, the two position switch may be integrated within the switch housing. This arrangement, while perhaps smaller than the two housing construction, adds another set of contacts to the switch with the attendant heat or contact deterioration concerns that arise from the motor current flowing through these contacts.
Another limitation of known power switches relates to the torque control for power tools. In some battery operated tools, mechanical clutches are used to set a torque limit for the tool. When the resistance to the rotation of the tool causes the torque generated by the tool to increase to the torque limit, the clutch slips to reduce the torque. The torque may then build again until it reaches the limit and the clutch slips again. The iterating action of clutch slippage followed by renewed torque buildup is sensed by the operator as vibration. This vibration informs the operator that the tool is operating at the set torque limit. This slippage also causes wear of the mechanical components from friction and impact.
Electric drills suffer the foregoing limitations. Moreover, electric drills are usually constructed as straight-drilling machines in which the drill spindle extends parallel to the motor shaft and axis of the housing and, for specific purposes, as angular-drilling machines in which the drill spindle is aligned at a right angle to the motor shaft and housing axis. In certain applications in which both straight and angular drilling must be carried out, as is the case in installations in wooden house construction, the two machines must be at hand for continuous alternation.
What is needed is an articulating power hand tool which does not require a large housing for mechanical switches. What is further needed is an articulating power hand tool with a reduced forward section and a compact articulating system to allow for use of the tool in confined areas.
SUMMARY
The present invention is an articulating hand power tool. In one embodiment, the tool includes an articulating hand power tool with a main housing having a longitudinal axis, a head portion rotatably engaged with the main housing for placement at a plurality of angles with respect to the longitudinal axis of the main housing, an integrated circuit board located within the main housing and at least one controller accessible from outside of the main housing for controlling the integrated circuit board.
In another embodiment, a hand power tool includes a longitudinally extending main housing, a head portion configured to be engaged with the main housing at a plurality of angles with respect to the longitudinal axis of the main housing, each of the plurality of angles within a single plane, an articulation gear system for providing motive force to a bit holder in the head portion including a motor side pinion gear having an axis of rotation generally parallel to a longitudinal axis of the housing and an output pinion gear having an axis of rotation generally parallel to a longitudinal axis of the head portion, wherein the motor side pinion gear is operatively connected to the output side pinion gear through a bevel gear, a controller operable from outside of the main housing and located generally on the plane and an integrated circuit located within the main housing and responsive to the controller.
One method in accordance with the invention includes rotating a head portion of a power tool to one of a plurality of angles with respect to the longitudinal axis of a main housing of the power tool, moving a variable speed trigger switch located outside of the main hosing, generating a variable speed signal with an integrated circuit located within the main housing in response to the movement of the variable speed trigger, controlling the speed of a motor located within the main housing based upon the variable speed signal and transferring motive force from the motor to a component within the head portion.
These and other advantages and features of the present invention may be discerned from reviewing the accompanying drawings and the detailed description of the preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may take form in various system and method components and arrangement of system and method components. The drawings are only for purposes of illustrating exemplary embodiments and are not to be construed as limiting the invention.
FIG. 1 shows a perspective view of an articulating drill incorporating features of the present invention;
FIG. 2 shows a side elevational view of the articulating drill of FIG. 1 with the rechargeable battery pack removed;
FIG. 3 shows a perspective view of the articulating drill of FIG. 1 with the battery pack, a portion of the main housing cover, and a portion of the head housing removed and a bit in the bit holder;
FIG. 4 shows a cross-sectional view of the head portion, the articulating gear system and the planetary gear system of the articulating drill of FIG. 1 ;
FIG. 5 shows an exploded perspective view of the head portion, including an automatic spindle lock system, of the articulating drill of FIG. 1 ;
FIG. 6 shows a top plan view of the head portion of the drill of FIG. 1 with some components located within bays in the head housing;
FIG. 7 shows a top plan view of a bracket used to support an output pinion shaft in the articulating drill of FIG. 1 ;
FIG. 8 shows a side plan view of the bracket of FIG. 7 ;
FIG. 9 shows a top elevational view of the planetary gear section, articulating section and head portion of the articulating drill of FIG. 1 with the main housing and a portion of the head housing removed;
FIG. 10 shows a side elevational view of the articulating gear system of the articulating drill of FIG. 1 including a bevel gear and two pinion gears;
FIG. 11 is a perspective view of a portion of the head housing of the drill of FIG. 1 with a plurality of teeth in a well which are formed complimentary to teeth on the articulation button;
FIG. 12 shows a perspective view of the articulating button of the articulating drill of FIG. 1 ;
FIG. 13 shows a perspective view of the bottom of the articulating button of FIG. 12 ;
FIG. 14 shows a partial top elevational view of the inner surface of the outer housing of the articulating drill of FIG. 1 with teeth formed complimentary to the teeth on the articulation button and a hole for receiving a raised portion of the articulating button;
FIG. 15 shows a top elevational view of the inner surface of the outer housing of the articulating drill of FIG. 1 ;
FIG. 16 shows a partial plan view of the articulating drill of FIG. 1 with the head portion aligned with the main housing portion and without a dust lid;
FIG. 17 shows a partial plan view of the articulating drill of FIG. 1 with the head portion aligned with the main housing portion with a dust lid;
FIG. 18 shows a side elevational view of the articulating drill of FIG. 18 with the head portion rotated to an angle of 90 degrees from the main housing portion of the drill and a portion of the main housing portion removed to show the position of the dust lid of FIG. 17 ;
FIG. 19 shows a side elevational view of the articulating drill of FIG. 18 with the head portion rotated to an angle of 180 degrees from the main housing portion of the drill and a portion of the main housing portion removed to show the position of the dust lid of FIG. 17 ;
FIG. 20 shows a detail view of the dust lid of FIG. 19 ;
FIG. 21 shows a perspective view of the articulating drill of FIG. 1 with the variable speed trigger switch, clutch control and a portion of the main housing removed;
FIGS. 22 a , 22 b and 22 c show various views of a printed circuit board of the articulating drill of FIG. 1 in accordance with principles of the invention;
FIG. 23 shows a perspective view of the articulating drill of FIG. 21 with a collapsible boot with an internal reflective surface installed over a light generator and a light sensor;
FIG. 24 shows a schematic/block diagram of the drill of FIG. 1 incorporating an optical switch for motor speed control;
FIG. 25 shows a side elevational view of a drill bit in the form of a screw driver bit that may be used with the articulating drill of FIG. 1 ;
FIG. 26 shows a cross-sectional view of the drill bit of FIG. 25 being inserted into the articulating drill of FIG. 1 ;
FIG. 27 shows a cross-sectional view of the drill bit of FIG. 25 inserted into the articulating drill of FIG. 1 ;
FIG. 28 shows a partial top elevational view of a bevel gear in accordance with principles of the invention with two pinion gears at a 90 degree spacing;
FIG. 29 shows a partial top elevational view of the bevel gear of FIG. 28 with the two pinion gears at a 180 degree spacing;
FIG. 30 shows an electrical diagram/schematic of a powered tool that dynamically brakes the tool motor using a motor interface circuit having a half bridge to provide vibratory feedback to the operator that the torque limit has been reached;
FIG. 31 shows an electrical diagram/schematic of a circuit that may be used with the drill of FIG. 1 which dynamically brakes the drill motor using a motor interface circuit having a full H-bridge circuit to provide vibratory feedback to the operator that the torque limit has been reached; and
FIGS. 32A and 32B show an electrical diagram/schematic of a powered tool that provides solid state motor speed control in correspondence with a variable speed signal from an optical switch and that dynamically brakes the motor to indicate a torque limit has been reached.
DESCRIPTION
An articulating drill generally designated 100 is shown in FIG. 1 . In the embodiment of FIG. 1 , the drill 100 includes a main housing portion 102 and a head portion 104 . The main housing portion 102 houses a motor and associated electronics for control of the drill 100 . The main housing portion 102 includes a battery receptacle for receiving a rechargeable battery pack 106 as is known in the art. In one embodiment, the rechargeable battery pack 106 comprises a lithium-ion battery. The battery pack 106 is removed by depression of the battery release tabs 108 . FIG. 2 shows the drill 100 with the battery pack 106 removed. The drill 100 may alternatively be powered by an external power source such as an external battery or a power cord.
A variable speed trigger switch 110 controls the speed at which the motor rotates. The direction of rotation of the motor is controlled by a reversing button 112 which slides within a finger platform 114 . Ventilation openings 116 allow for cooling air to be circulated around the motor inside of the main housing 102 . A clutch control 118 sets the maximum torque that may be generated when using the drill 100 . At the position shown in FIG. 1 , the clutch control 118 is at the highest setting or drill mode. At the highest setting, the clutch is disabled to provide maximum torque. By sliding the clutch control 118 downwardly from the position shown in FIG. 1 , a user may set a desired torque limit that is allowed to be generated by the drill 100 as discussed in more detail below. Accordingly, at settings other than the highest setting, a torque above the setting of the clutch control 118 causes the clutch to activate.
The main housing portion 102 also includes an articulation button 120 and a plurality of angle reference indicators 122 molded onto the outer surface 124 of the main housing 102 . In the embodiment of FIG. 1 , there are five angle reference indicators 122 used to identify five angular positions in which the head portion 104 may be placed.
The head portion 104 includes a collet locking device 126 and an angle indicator 128 . The angle at which the head portion 104 is positioned is indicated by the angle reference indicator 122 with which the angle indicator 128 is aligned. As shown in FIG. 1 , the head portion 104 is at a 90 degree angle with respect to the main housing portion 102 . In FIG. 2 , the head portion 104 is axially aligned with the main housing portion 102 . Although the embodiment of FIGS. 1 and 2 has five angle reference indicators 122 , there may be additional or fewer angle reference indicators 122 and corresponding angles at which the head portion 104 may be placed with respect to the main housing portion 102 .
Referring now to FIGS. 3-6 , the collet locking device 126 is located around a bit holder 130 which is in turn supported by a ball bearing 132 that is fixed within a bearing pocket 134 of the head housing 136 . The collet locking device 126 includes a sleeve 138 with recesses 140 . A spring 142 is positioned about the bit holder 130 . The bit holder 130 includes a hole 144 which receives a cylinder pin 146 and recesses 148 which receive steel balls 150 .
The bearing 132 abuts the head housing 136 of the head portion 104 at the outer rear periphery of the bearing 132 . More specifically, the bearing 132 abuts a flange 152 . In this embodiment, the flange 152 is continuous about the housing 136 , although a flange may alternatively be in the form of a plurality of fins located about the inner portion of the housing 136 .
The bit holder 130 is operably coupled to a drive collet 154 which is in turn connected to an output pinion shaft 156 through a drive plate 158 which is fixedly attached to the output pinion shaft 156 . A lock ring 160 surrounds the drive collet 154 and three locking pins 162 . The lock ring 160 , the drive collet 154 , the drive plate 158 , and the locking pins 162 all comprise an automatic spindle lock system such that the output bit holder 130 can only be driven from the pinion side as known in the art. When driven from the bit side, i.e., when the tool 100 is used as a manual screwdriver, the spindle lock system keeps the output pinion shaft 156 from rotating thus facilitating use of the tool 100 as a manual screwdriver. In an alternative embodiment, a manually manipulated locking device may be used.
A pinion gear 164 is located at the opposite end of the output pinion shaft 156 from the drive plate 158 . One end of the output pinion shaft 156 is maintained in axial alignment by a bearing 166 which fits within bearing pocket 168 . The opposite end of the output pinion shaft 156 is supported by a sleeve 170 . The sleeve 170 is supported on one side by a flange 172 on the head housing 136 . On the opposite side, the sleeve 170 is supported by a bracket 174 also shown in FIGS. 7 and 8 .
The bracket 174 includes a support area 176 configured complimentary to a portion of the sleeve 170 . Two connection arms 178 are configured to be attached to the head housing 136 as shown in FIG. 9 . The bracket 174 eliminates the need to provide a matching flange for flange 172 molded into the opposite side of the head housing 136 . The elimination of the need for an opposing flange allows for a significant increase in design freedom as the space requirements for the support structure for the sleeve 170 are reduced. The bracket 174 may be stamped from W108 steel to provide the needed rigidity and strength.
Referring now to FIG. 10 , the pinion gear 164 forms a portion of an articulating gear system 180 . The articulating gear system 180 further includes a bevel gear 182 which is engaged at the output portion of the articulating gear system 180 with the pinion gear 164 and further engaged on the motor portion by pinion gear 184 . The shaft 186 of the bevel gear 182 is supported at one end within a hole 188 (see FIG. 4 ) of the frame 190 . The frame 190 is made from a zinc and aluminum alloy ZA-8. This material provides a sufficiently low coefficient of friction to ensure relatively small frictional forces exist between the shaft 186 and the frame 190 .
The shaft 186 is radially and axially supported at the opposite end by a ball bearing 192 supported by the frame 190 . At this end of the shaft 186 , however, comparatively larger forces are generated than at the end of the shaft 186 inserted within the hole 188 . More specifically, as shown in FIG. 10 , both pinion gear 164 and pinion gear 184 are located on the same side of the bevel gear 182 . Accordingly, as the articulating gear system 180 rotates, a force is generated on the bevel gear 182 in the direction of the arrow 194 toward the base 196 of the bevel gear 182 . This force acts to disengage the bevel gear 182 from the pinion gear 164 and the pinion gear 184 . With this increased force acting upon the bevel gear 182 , an unacceptable amount of axial force would be transmitted to the bearing 192 . Accordingly, a thrust bearing 198 is provided to protect the ball bearing 192 and to provide a low friction support for the base 196 of the bevel gear 182 . The thrust bearing 198 is made of a material with an acceptably low coefficient of friction such as oil impregnated bronze commercially available from McMaster Carr of Chicago, Ill. Accordingly, the friction generated at the base 196 of the bevel gear 182 is maintained within acceptable levels.
Referring again to FIG. 4 , the pinion gear 184 is fixedly attached to a planetary gearbox shaft 200 which receives torque from a planetary gear system generally indicated as reference numeral 202 . The planetary gear system 202 receives torque from a motor as is known in the art. The planetary gear system 202 is located within a planetary gear housing 204 which is inserted partially within the frame 190 . This arrangement allows for the planetary gear system 202 to be separately manufactured from the other components while simplifying assembly of the planetary gear system 202 with the other components. This modularity further allows for alternative gearings to be provided in the planetary gear system 202 while ensuring a proper fit with the other components.
Generally, it may be desired to provide a simple friction fit between the planetary gear housing 204 and the frame 190 . In the embodiment of FIG. 4 , however, the articulating gear system 180 generates an axial force along the planetary gearbox shaft 200 . This axial force acts to disengage the planetary gear housing 204 from the frame 190 . Accordingly, pins 206 and 208 which extend through both the planetary gear housing 204 and the frame 190 are provided. The pins 206 and 208 ensure the planetary gear housing 204 does not become detached from the frame 190 during operation of the drill 100 . Alternatively, the planetary gear housing 204 and the frame 190 may be formed as an integral unit.
Continuing with FIG. 4 , the frame 190 is configured to slidingly mate with the head housing 136 . To this end, the head housing 136 includes a shroud portion 210 which is complimentarily formed to the frame 190 about the ball bearing 192 . The head housing 136 further includes a recess 212 which is configured to receive the portion of the frame 190 which defines the hole 188 . Also shown in FIG. 4 is a well 214 which includes a plurality of teeth 216 shown in FIG. 11 .
With further reference to FIGS. 12-14 , the well teeth 216 are formed complimentary to a plurality of teeth 218 which are formed in the articulation button 120 . The articulation button 120 includes a raised center portion 220 which is configured to fit within a hole 222 in the main housing portion 102 . The teeth 218 of the articulation button 120 are further configured to mesh with a plurality of teeth 224 formed on the inner side of the main housing portion 102 around the hole 222 . The articulation button 120 also includes a spring receiving well 226 on the side of the articulation button 120 facing the well 214 . When assembled, a spring (not shown) is located within the well 214 and extends into the spring receiving well 226 forcing the raised center portion 220 of the articulation button 120 toward a position wherein the articulation button 120 projects into the hole 222 .
Referring to FIGS. 4 and 15 , the frame 190 is supported axially in the main housing portion 102 , which in this embodiment is made of plastic, by a rib 228 . The rib 228 lies beneath a fin 230 of the frame 190 when the frame 190 is installed in the main housing portion 102 as shown in FIG. 3 . The planetary gear system 202 is mechanically secured to a motor 232 which is itself electrically connected to a printed circuit board 234 which in turn is electrically connected to a battery contact holder 236 . The contact holder 236 mates with battery pack receptacles on the battery pack 106 and transmits battery power to the electronic circuit board 234 through lead wires (not shown). Another pair of lead wires (not shown) extend from the circuit board 234 to the motor terminals 238 to deliver the required voltage level to the motor 232 .
Referring now to FIG. 5 , a gap 240 is provided in the portion of the head housing 136 surrounding the bevel gear 182 which allows the head housing 136 to be rotated with respect to the main housing portion 102 while the pinion gear 164 remains engaged with the bevel gear 182 . When the head portion 104 is axially aligned with the main housing portion 102 , however, the gap 240 is exposed as shown in FIG. 16 . The articulating gear system 180 is thus exposed allowing contaminants access to the articulating gear system 180 which could foul the articulating gear system as well as presenting a safety concern since clothing, fingers or hair could become enmeshed in the articulating gear system 180 . Accordingly, a floating dust lid 242 shown in FIG. 17 is used to prevent contamination of the articulating gear system 180 and to avoid exposure of moving gears to an operator through the gap 240 , particularly when the head housing 136 is axially aligned with the main housing portion 102 as shown in FIG. 17 .
The dust lid 242 is located in a channel 244 defined by the main housing portion 102 and the head housing 136 as shown in FIGS. 18-20 . The position of the dust lid 242 at the lower portion (as depicted in FIGS. 18 and 19 ) of the channel 244 is constrained either by a movable dust lid travel limiter 246 positioned on the head housing 136 , shown most clearly in FIGS. 11 and 20 , or by a portion 248 of the frame 190 . The position of the dust lid 242 at the upper portion of the channel 244 is constrained either by a neck portion 250 of the head housing 136 or by a lip 252 in the main housing portion 102 .
Referring now to FIGS. 3 , and 21 - 23 , the clutch control 118 is mechanically interfaced with a linear potentiometer 254 on the circuit board 234 . Also located on the circuit board 234 is a light sensor 256 which is covered by a collapsible rubber boot 258 which is in turn mechanically fastened to the variable speed trigger 110 . A reflective surface 260 (see FIG. 24 ) is located on the inside of the rubber boot 258 . A plastic spring locating member 262 which is mechanically secured to the circuit board 234 serves to locate and support a spring 264 which is mechanically fastened to the variable speed trigger 110 . The spring 264 biases the variable speed trigger 110 in a direction away from the circuit board 234 about a pivot 266 . The circuit board 234 also contains a two position slide switch 268 which is mechanically interfaced to the reversing button 112 .
Manipulation of the variable speed trigger 110 about the pivot 266 changes the position of the reflective surface 260 relative to the light sensor 256 to produce a variable speed control signal. While the embodiment of tool 100 incorporates an optical signal generator and receiver for provision of a variable speed control signal, such a tool may alternatively use a pressure transducer, a capacitive proximity sensor, or an inductive proximity sensor. In these alternative embodiments, a pressure sensing switch for generating the variable motor speed control signal may include a pressure transducer for generating a variable speed control signal that corresponds to a pressure applied to the pressure transducer directly by the operator or through an intermediate member such as a moveable member that traverses the distance between the stop position and the full speed position.
An embodiment of the variable motor speed control signal implemented with a capacitive proximity sensor may include a capacitive sensor that generates a variable speed control signal that corresponds to an electrical capacitance generated by the proximity of an operator's finger or moveable member's surface to the capacitive sensor. An embodiment implemented with an inductive proximity sensor generates a variable speed control signal that corresponds to an electrical inductance generated by the proximity of an operator's finger or moveable member's surface to the inductive sensor.
Referring to FIG. 24 , the variable speed control circuit 270 of the tool 100 is schematically shown. The variable speed control circuit 270 includes a power contact 272 which is operably connected to the variable speed trigger switch 110 . An optical signal generator 274 is coupled to the battery 106 and arranged on the circuit board 232 such that light emitted from the optical signal generator 274 is directed toward the reflective surface 260 of the variable speed trigger switch 110 and directed toward the light sensor 256 .
The light sensor 256 and the optical signal generator 274 may be located in the same housing or each may be within a separate housing. When the two components are located in the same housing, the light generator and sensor may emit and receive light through a single sight glass in the housing. Alternatively, each component may have a separate sight glass. An integrated component having the light generator and sensor in a single housing is a QRD1114 Reflective Object Sensor available from Fairchild Semiconductor of Sunnyvale, Calif. Such a housing is substantially smaller than a potentiometer that has a wiper, which traverses approximately the same distance as the trigger traverses from the stop to the full speed position.
The optical signal generator 274 and the light sensor 256 may be an infrared light emitter and an infrared light receiver. In an alternative embodiment, an IR transceiver may be contained within a flexible dust cover that is mechanically fastened to the back of the variable speed trigger switch. In such an embodiment, the inside of the cover in the vicinity of the moveable trigger reflects the optical signal to the receiver for generating the speed control signal.
Control of a tool incorporating the light sensor 256 may be adversely affected by external energy sources such as the sun. Accordingly, in one embodiment, the collapsible boot or dust cover 258 is made from an opaque material or coated with an opaque material such that energy from the sun which may leak past the housing and trigger arrangement does not affect the signal received by the light sensor 256 . Alternatively, a light sensor that is sensitive to a specific frequency band may be used with a device which shields the light sensor from only that specific frequency band. In further embodiments, other circuitry or coding which uniquely identifies the energy from the reflected signal from interfering energy may be used.
The light sensor 256 is an optical transistor having a collector 276 coupled to the battery pack 106 through the contact 272 and an emitter 278 coupled to electrical ground though a voltage divider 280 and a capacitor 282 . A timing signal generator 284 receives voltage from the voltage divider 280 . In the tool 100 , the timing signal generator 264 is a commonly known “555” timer, although other timing signal generators may be used.
The output of the timing signal generator 264 is coupled to a gate 286 of a MOSFET 288 that has a drain 290 coupled to one of the motor terminals 238 and a source 292 coupled to electrical ground. The other motor terminal 238 is coupled to the battery pack 106 through the contact 272 . A freewheeling diode 294 is coupled across the motor terminals 238 . A bypass contact 296 , which is operatively connected to the variable speed trigger switch 110 , is located in parallel to the MOSFET 288 between the motor terminal 238 and electrical ground and a brake contact 298 is in parallel with the freewheeling diode 294 .
Operation of the drill 100 is explained with initial reference to FIGS. 24-26 . The collet locking device 126 is configured to operate with bits such as the screw driver bit 300 shown in FIG. 24 . The screw driver bit 300 and the bit holder 130 are complimentarily shaped. In this example, both the screw driver bit 300 and the bit holder 130 are generally hexagonal in shape, although alternative shapes may be used. The screw driver bit 300 has a diameter slightly less than the bit holder 130 so that it may fit within the bit holder 130 . The screw driver bit 300 includes a notched area 302 and a tail portion 304 .
Initially, the sleeve 138 is moved to the right from the position shown in FIG. 4 to the position shown in FIG. 26 thereby compressing the spring 142 . As the sleeve 138 moves, recesses 140 in the sleeve 138 are positioned adjacent to the recesses 148 in the bit holder 130 . Then, as the screw driver bit 300 is moved into the bit holder 130 , the tail portion 304 forces the steel balls 150 toward the recesses 140 and out of the channel of the bit holder 130 , allowing the tail portion 304 to move completely past the steel balls 150 .
At this point, the notched area 302 is aligned with the recesses 148 . The sleeve 138 is then released, allowing the spring 142 to bias the sleeve 138 onto the bit holder 130 which is to the left from the position shown in FIG. 27 . As the sleeve 138 moves, the recesses 140 are moved away from the recesses 148 thereby forcing the steel balls 150 partially into the channel of the bit holder 130 as shown in FIG. 27 . Movement of the steel balls 150 into the channel of the bit holder 130 is allowed since the notched area 302 is aligned with the recesses 148 . At this point, the bit 300 is firmly held within the bit holder 130 .
The head housing 136 is then articulated to a desired angle with respect to the main housing portion 102 . Initially, the spring (not shown) in the spring receiving well 226 forces the articulation button 120 to extend into the hole 222 . Accordingly, the teeth 218 of the articulation button 120 are meshed with the teeth 224 in the main housing portion 102 as well as the teeth 216 in the well 214 of the head housing 136 , thereby angularly locking the articulation button 120 (and the head housing 136 ) with the main housing portion 102 . Additionally, the dust lid 242 is constrained at the upper portion of the channel 244 by the neck portion 250 of the head housing 136 and at the lower portion of the channel 244 by the portion 248 of the frame 190 as shown in FIG. 18 .
The operator then applies force to the articulation button 120 causing the spring (not shown) to be depressed thereby disengaging the teeth 218 from the teeth 224 . Thus, even though the teeth 218 remain engaged with the teeth 216 , the head portion 104 is allowed to pivot with respect to the main housing portion 102 . As the head portion 104 is articulated, for example, from the position shown in FIG. 1 to the position shown in FIG. 2 , the pinion gear 164 articulates about the bevel gear 182 . By way of example, FIG. 28 shows the positions of the pinion gears 164 and 184 with respect to the bevel gear 182 when the drill 100 is in the configuration shown in FIG. 1 . In this configuration, the pinion gear 164 is approximately 90 degrees away from the pinion gear 184 about the perimeter of the bevel gear 182 . As the head portion 104 is articulated in the direction of the arrow 306 , the pinion gear 164 articulates about the bevel gear 182 in the same direction. Thus, when the head portion 104 is aligned with the main housing portion 102 , the pinion gear 164 is positioned on the bevel gear 182 at a location 180 degrees away from the pinion gear 184 as shown in FIG. 29 .
Throughout this articulation, the pinion gears 164 and 184 remain engaged with the bevel gear 182 . Accordingly, the bit holder 130 may be rotated by the motor 232 as the head housing 136 is articulated. Additionally, the articulation of the head housing 136 causes the movable dust lid travel limiter 246 to contact the dust lid 242 and push the dust lid 242 along the channel 244 . Thus, the dust lid 242 , which is configured to be wider than the gap 240 as shown in FIG. 17 , restricts access from outside of the drill 100 to the articulating gear system 180 .
When the articulating drill 100 is rotated to the desired location, the operator reduces the force applied to the articulating button 120 . The spring (not shown) in the spring receiving well 226 is then allowed to force the articulation button 120 away from the well 214 until the articulation button 120 extends through the hole 222 . Accordingly, the teeth 218 of the articulation button 120 are meshed with the teeth 224 in the main housing portion 102 as well as the teeth 216 in the well 214 of the head housing 136 , thereby angularly locking the articulation button 120 (and the head housing 136 ) with the main housing portion 102 .
The desired direction of rotation for the bit 300 is then established by placing the reversing button 112 in the position corresponding to the desired direction of rotation in a known manner. Rotation is accomplished by moving the variable speed trigger switch 110 about the pivot 266 to close the power contact 272 . The closing of the contact 272 completes a circuit allowing current to flow to the optical signal generator 274 causing light to be emitted.
The emitted light strikes the reflective surface 260 and a portion of the light is reflected toward the light sensor 256 . The amount of light reflected by the reflective surface 260 increases as the reflective surface 260 is moved closer to the light sensor 256 . The increased light sensed by the light sensor 256 causes increased current to be conducted by the light sensor 256 and the flow of current through the light sensor 256 causes current to flow from the collector 276 to the emitter 278 . Thus, as the intensity of the light impinging on the light sensor 256 increases, the current conducted by the light sensor 256 increases. This increase in current causes the voltage level presented by the voltage divider 280 to the timing signal generator 284 to increase. The increased signal is the variable speed signal and it causes the timing signal generator 284 to generate a timing signal in a known manner. In the depicted drill 100 , the timing signal generator 284 is a commonly known “555” timer, although other timing signal generators may be used.
The timing signal generator 284 generates a timing pulse having a logical on-state that corresponds to the level of the variable speed signal. This signal is presented to the gate 286 of the MOSFET 288 . When the signal present at the gate 286 is a logical on-state, the MOSFET 288 couples one of the motor terminals 238 to ground while the other motor terminal 238 is coupled to battery power through the main contact 272 . Thus, when the variable speed trigger switch 110 reaches a position where the light sensor 256 begins to detect reflected light and generate a variable speed signal, the timing signal generator 284 begins to generate a signal that causes the MOSFET 288 to couple one of the motor terminals 238 to ground. Once this occurs, current begins to flow through the MOSFET 288 and the motor 232 begins to rotate in the direction selected by the reversing button 112 .
The freewheeling diode 294 causes appropriate half-cycles of the current in the windings of the motor 232 to flow out of the motor 232 , through the diode 294 , and back into the motor 232 when the MOSFET 288 does not conduct in response to the timing signal being in the off-state. This action is known as freewheeling and is well known.
When the variable speed trigger 110 is in the full speed position, the timing signal is predominantly in the on-state and the bypass contact 296 closes. The closing of the bypass contact 296 enables the battery current to continuously flow through the motor 232 so that the motor 232 rotates at the highest speed.
When rotation is no longer desired, the operator releases the variable speed trigger switch 110 and the spring 264 causes the variable speed trigger switch 110 to rotate about the pivot 266 causing the bypass contact 296 to open. Additionally, the brake contact 298 closes thereby coupling the motor terminals 238 . The coupling of the two motor terminals 238 to one another through the brake contact 298 enables dynamic braking of the motor.
The electronic control of the tool 100 thus requires less space for the components that generate the variable speed signal than prior art control systems. Because the distance traveled by the variable speed trigger switch 110 does not have to be matched by the light signal generator 274 and the light sensor 256 , considerable space efficiency is gained. Additionally, the light signal generator 274 and the light sensor 256 do not require moving parts, so reliability is improved as well. Advantageously, the light signal generator 274 and the light sensor 256 may be mounted on the same printed circuit board 234 on which the timing signal generator 284 is mounted.
As the drill 100 is operated, the bit 300 is subjected to axial forces. The axial forces may result from, for example, pressure applied by the operator or by an impact on the bit. In either instance, the articulating gear system 180 is protected from damage without increasing the bulk of the components within the articulating gear system 180 . This is accomplished by directing axial forces from the bit 300 to the main housing portion 102 of the drill 100 while bypassing the articulating gear system. With initial reference to FIG. 27 , an impact on the bit 300 tends to move the bit 300 further into the drill 100 , or to the left as depicted in FIG. 27 . In prior art designs, not only could such a force damage the gear system, but the steel balls used to retain the bit within the bit holder would frequently jam necessitating replacement of the collet locking device.
As shown in FIG. 27 , however, the cylinder pin 146 is positioned such that the tail portion 304 of the bit 300 will contact the cylinder pin 146 before the wall of the notched area 302 contacts the steel balls 150 . Thus, an axial impact will not cause the steel balls 150 to jam. Of course, the cylinder pin 146 must be made from a material sufficient to withstand the axial impact. In accordance with one embodiment, the cylinder pin 146 is made of AISI 4135 steel.
Referring now to FIG. 4 , in the event of an axial impact, the force is transferred from the cylinder pin 146 to the to the bit holder 130 . The axial force is transmitted from the bit holder 130 to the bearing 132 which is located within the bearing pocket 134 . Accordingly, the axial force is transferred into the flange 152 (see also FIG. 5 ) of the head housing 136 . The head housing 136 in this embodiment is made from aluminum alloy A380 so as to be capable of receiving the force transmitted by the bearing 132 . The force is subsequently transferred to the frame 190 and into the rib 228 of the main housing portion 102 .
More specifically, two paths for the transfer of axial forces are provided around the articulating gear system 180 . The first path predominantly transfers axial forces when the head housing 136 is axially aligned with the main housing portion 102 . In this configuration, axial forces pass from head housing 136 to the frame 190 primarily through the recess 212 where the head housing 136 engages the frame 190 about the hole 188 (see FIG. 4 ) and at the shroud portion 210 where the head housing 136 engages the frame 190 outwardly of the base of the bevel gear 196 .
The second path predominantly passes axial forces when the head housing 136 is at a ninety degree angle with respect to the main housing portion 102 . In this configuration, axial forces are again transferred from the cylinder pin 146 to the to the bit holder 130 . The axial forces then pass primarily from the teeth 216 in the well 214 of the head housing 136 to the teeth 218 on the articulation button 120 and then to the teeth 224 in the main housing portion 102 .
When the head housing 136 is neither completely aligned with the main housing portion 102 or at a ninety degree angle with respect to the main housing portion 102 , axial forces generally pass through both of the foregoing pathways. Accordingly, the effect of axial forces on the articulating gear system 180 of the drill 100 are reduced. Because the articulating gear system 180 is thus protected, the articulating gear system 180 may be constructed to be lighter than other articulating gear systems.
In one embodiment, a printed circuit board which may be used in the drill 100 or another power tool includes a circuit that provides vibratory feedback to the operator as shown in FIG. 30 . The vibratory feedback circuit 308 includes a microcontroller 310 , a driver circuit 312 , and motor interface circuit 314 . The driver circuit 312 in this embodiment is an integrated circuit that generates driving signals for a half-bridge circuit from a single pulse width modulated (PWM) signal, a torque limit indicating signal, which may be the same signal as the PWM signal, and a motor direction control signal. The driver circuit 312 may be a half bridge driver, such as an Allegro 3946 , which is available from Allegro Microsystems, Inc. of Worcester, Mass.
The output of the driver circuit 312 is connected to a motor 316 through two transistors 318 and 320 which may be MOSFETs, although other types of transistors may be used. The transistor 318 may be connected to either terminal of the motor 316 through switches 322 and 324 while the transistor 320 may be connected to either terminal of the motor 316 through switches 326 and 328 . A shunt resistor 330 is coupled between the transistor 320 and electrical ground. The high potential side of the resistor 330 is coupled to the microcontroller 310 through an amplifier 332 . A power source 334 is also provided in the vibratory feedback circuit 308 and a maximum torque reference signal is provided from a torque reference source 336 which may be a linear potentiometer such as the linear potentiometer 254 .
The half-bridge control of the motor 316 eliminates the need for a freewheeling diode because the driver circuit 312 generates motor interface circuit signals for selectively operating the motor interface circuit 314 to control the rotational speed of the motor 316 . More specifically, a variable speed control signal 338 , which may be from a trigger potentiometer or the like, is provided to the microcontroller 310 for regulation of the rotation of the motor 316 by the microcontroller 310 . Based upon the variable speed control signal 338 , the microcontroller 310 generates a PWM signal that is provided to the driver circuit 312 . In response to the PWM signal, the driver circuit 312 turns transistors 318 and 320 on and off.
During typical operations, the transistor 318 is the complement of the transistor 320 such that when the transistor 320 is on, the transistor 318 is off. The rate at which the transistor 320 is turned on and off determines the speed of motor 316 . The direction of rotation of the motor 316 is determined by the position of the switches 322 , 324 , 326 and 328 under the control, for example, of a reversing switch.
The current through the motor 316 is provided through the transistor 320 and the resistor 330 to electrical ground when the transistor 320 is in the on-state. This current is related to the torque at which the motor 316 is operating. Thus, the voltage at the high potential side of the resistor 330 is related to the torque on the motor 316 . This motor torque signal is amplified by the amplifier 332 and provided to the microcontroller 310 . The microcontroller 310 compares the amplified motor torque signal to the torque limit signal established by the torque reference source 336 . The torque limit signal, which may alternatively be provided by a different type of torque limit signal generator, provides a reference signal to the microcontroller 310 that corresponds to a current through the motor 316 that represents a maximum torque setting for the motor 316 .
In response to the microcontroller 310 receiving a motor torque signal that exceeds the maximum torque setting for the motor 316 , the microcontroller 310 generates a braking signal that is provided to the driver circuit 312 . In response to the braking signal, the driver circuit 312 turns transistor 320 to the off-state and leaves transistor 318 in the on-state. This enables regenerative current to dynamically brake the rotation of the motor 316 .
As dynamic braking occurs, the torque experienced by the motor 316 decreases until the sensed torque is less than the maximum torque setting for the motor 316 . The microcontroller 310 then returns the transistor 320 to the on-state, thereby rotating the motor 316 and increasing the torque experienced by the motor 316 . In this manner, the motor 316 alternates between rotating and dynamically braking which causes the tool to vibrate and alert the operator that the torque limit has been reached. An effective frequency for providing this vibratory feedback is 30 Hz. The torque limit indicating signal that results in this operation continues as long as the trigger remains depressed. Alternatively, the microcontroller may be programmed to generate the torque limit indicating signal for a fixed duration and then to stop to reduce the likelihood that the motor will be overpulsed.
In one embodiment, vibratory feedback is provided for the drill 100 with the circuit shown in FIG. 31 . The vibratory feedback circuit 340 includes a microprocessor 342 , an H-bridge driver circuit 344 and a motor interface circuit 346 . Four MOSFETs 348 , 350 , 352 and 354 control power to the motor 232 from the rechargeable battery pack 106 under the control of the H-bridge driver circuit 344 . A shunt resistor 356 is provided between the MOSFETs 352 and 354 and electrical ground. The signal at the high potential side of the resistor 356 corresponds to the torque being generated by the motor 232 . This motor torque signal is amplified by an amplifier circuit 358 , which may be implemented with an operational amplifier as shown in FIG. 31 , and provided to the microcontroller 342 . The microcontroller 342 compares the motor torque signal to the torque limit signal and generates a torque limit indicating signal in response to the motor torque signal being equal to or greater than the torque limit signal. The torque limit indicating signal may have a rectangular waveform.
In one embodiment, the microcontroller 342 provides a torque limit indicating signal that is a rectangular signal having an off-state of at least 200 μseconds at a frequency of approximately 30 Hz. This torque limit indicating signal causes the driver circuit 344 to generate motor interface control signals that disconnect power from the motor 232 and couple the MOSFETs 348 , 350 , 352 and 354 together so the current within the windings of the motor 232 flows back through the motor 232 to dynamically brake the motor 232 .
The dynamic braking causes the motor 232 to stop. Before application of the next on-state pulse, the microcontroller inverts the signal to the direction control input of the H-bridge driver 344 . Thus, the subsequent on-state of the rectangular pulse causes the H-bridge driver circuit 344 to operate the H-bridge to couple the motor 232 to the rechargeable battery pack 106 with a polarity that is the reverse of the one used to couple the motor 232 and the rechargeable battery pack 106 prior to braking. This brake/reverse/start operation of the motor at the 30 Hz frequency causes the tool to vibrate in a manner that alerts the operator that the torque limit has been reached while preventing the bit from continuing to rotate during the clutching operation. The dynamic braking may also be used without inverting the signal.
In yet another embodiment, the rectangular waveform may be generated for a fixed duration, for example, 10 to 20 pulses, so the motor is not over-pulsed. Also, the microcontroller 342 may invert the direction control signal to the H-bridge driver 344 during the off-time of the rectangular waveform so that the motor 232 starts in the opposite direction each time. This action results in the net output rotation being zero during the clutching duration. Additionally, the microcontroller 342 may disable the clutching function in response to the motor direction control signal indicating reverse, rather than forward, operation of the motor 232 .
FIGS. 32A and 32B show an embodiment of a circuit used in a tool that eliminates the need for mechanical contacts. The circuit 360 includes an optical speed control switch 362 , a two position forward/reverse switch 364 , a microcontroller 366 , a driver circuit 368 , an H-bridge circuit 370 , a motor 372 , a shunt resistor 374 , a motor torque signal amplifier 376 , and a torque limit signal generator 378 . In this embodiment, power is coupled to the motor 372 through the H-bridge circuit 370 , but the main contact, brake contact, and bypass contact are no longer required. Thus, this embodiment significantly reduces the number of components that are subject to mechanical wear and degradation. Because the optical control switch 362 , microcontroller 366 , driver circuit 368 , H-bridge circuit 370 , and torque signal amplifier 376 may all be implemented with integrated circuits, then ICs may be mounted on a common printed circuit and the space previously occupied by the mechanical contacts and variable signal potentiometer are gained. This construction further enables the tool components to be arranged in more efficient geometries.
In the circuit 360 , the optical speed control switch 362 operates as described above to generate a variable control signal from the reflection of an optical signal directed at the reflective surface of a pivoting trigger. The variable speed control signal is provided to the microcontroller 366 for processing. The microcontroller 366 , which may be a microcontroller available from Texas Instruments and designated by part number MSP430, is programmed with instructions to generate a PWM pulse with an on-state that corresponds to the level of the variable speed signal. The microcontroller 366 provides the PWM signal to the driver circuit 368 for generation of the four motor interface control signals used to couple battery power to the motor 372 . The direction in which the motor 372 is driven is determined by the contacts in the two position forward/reverse switch 364 through which a signal is provided to the microcontroller 366 . In the circuit 360 , the contacts of the two position forward/reverse switch 364 do not need to carry the current provided to the motor 372 so the contacts of the two position forward/reverse switch 364 may be smaller than contacts in other systems. The directional signal is also provided by the microcontroller 366 to the driver circuit 368 so the driver circuit 368 is capable of two directional control of current in the H-bridge circuit 370 .
The motor torque signal amplifier 376 provides the torque signal from the high potential side of the shunt resistor 374 to the microcontroller 366 . The torque limit signal generator 378 may be implemented with a potentiometer as described above to provide a reference signal for the microcontroller 366 . When the microcontroller 366 determines that the motor torque signal equals or exceeds the motor torque limit, the microcontroller 366 generates a torque limit indicating signal so the driver circuit 368 generates the motor interface control signals that operate the motor 372 in a manner that causes vibration. For the TD340 driver circuit, the torque limit indicating signal generated by the microcontroller 366 is a rectangular signal having an off-state of at least about 200 μseconds at a frequency of about 30 Hz.
While the present invention has been illustrated by the description of exemplary processes and system components, and while the various processes and components have been described in considerable detail, applicant does not intend to restrict or in any limit the scope of the appended claims to such detail. Additional advantages and modifications will also readily appear to those skilled in the art. The invention in its broadest aspects is therefore not limited to the specific details, implementations, or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept. | The present invention is an articulating hand power tool with a main housing having a longitudinal axis, a head portion rotatably engaged with the main housing for placement at a plurality of angles with respect to the longitudinal axis of the main housing, an integrated circuit board located within the main housing and at least one controller accessible from outside of the main housing for controlling the integrated circuit board. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to selected aryl N,N'-bis cinnamamide compounds and their use as ultraviolet light stabilizers.
2. Description of the Prior Art
Ultraviolet (UV) radiation having wave lengths from about 280 to about 400 nm may cause the degradation of exposed organic matter such as plastics and will burn and/or induce tumors in human skin. To negate these undesirable actions, plastics and the like are protected by chemical additives called UV stabilizers and the human skin and hair is protected by cosmetics containing UV stabilizers (e.g. sunscreens).
To be viable for commercial applications, a UV stabilizer should preferably have a strong ultraviolet light absorptivity at wave lengths between 280 and 400 nm, be photostable by itself, be compatible with the substrate (e.g. plastic or cosmetic emulsion) in which it is used as an additive, be non-volatile at the high temperatures involved during incorporation and processing stages as well as during certain end uses, possess low color, be chemically inert, have low or no toxicity or skin sensitization/irritation properties, be non-mutagenic, and be stable to the environments experienced during its processing and application. Furthermore, for human sunscreen use, it is also desirable that the UV stabilizer be relatively insoluble in water.
Accordingly, it is an object of the present invention to provide a novel class of UV light stabilizer compounds.
A specific object of this invention is to provide a novel class of UV light stabilizer compounds which may be used to stabilize ultraviolet degradable organic compositions against deterioration resulting from the exposure to such UV radiation.
Another specific object is to provide a novel class of UV light stabilizer compounds which may be used in human cosmetic products such as sunscreens, hair dyes and hair tinting compositions to prevent or retard UV radiation from penetrating the human skin or hair.
These and other objects and features of the invention will be made apparent from the following more particular description of the invention.
BRIEF SUMMARY OF THE INVENTION
The present invention, therefore, is directed to aryl N,N'-bis cinnamamide compounds having formula (I): ##STR2## wherein x equals an integer from 0 to 3; y equals an integer from 0 to 2; z equals an integer from 0 to 2; each R is individually selected from the group consisting of a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having from 1 to 4 carbon atoms, a halo group, a nitro group, an aryl group having 6 to 18 carbon atoms, and a fused unsubstituted or substituted aromatic ring when x is 2 or 3; and each R' and R" is individually selected from the group consisting of a lower alkyl group having from 1 to 4 carbon atoms, a lower alkoxy group having from 1 to 4 carbon atoms, a halo group, a nitro group or an aryl group having from 6 to 18 carbon atoms.
Also, the present invention is directed to organic compositions susceptible to ultraviolet degradation being stabilized against such degradation with an effective stabilizing amount of an aryl N,N-bis cinnamamide compound having formula (I) above.
Still further, the present invention is directed to a process for stabilizing an organic composition susceptible to ultraviolet degradation comprising incorporating into said organic composition an effective stabilizing amount of an aryl N,N'-bis cinnamamide compound having formula (I), above.
Furthermore, the present invention is directed to human sunscreen compositions which effectively prevent or retard UV light from penetrating human skin or hair, said sunscreen compositions comprising an effective screening amount of an aryl N,N'-bis cinnamamide compound having formula (I), above.
And even further, the present invention is directed to a process for substantially screening out UV light from human skin or hair comprising applying a sunscreen composition on said skin or hair to prevent or retard UV light from penetrating to said skin or hair, said sunscreen composition comprising an effective screening amount of an aryl N,N'-bis cinnamamide compound of formula (I), above.
DETAILED DESCRIPTION
These aryl N,N'-bis cinnamamides (also known as N,N'-dicinnamoyl-aryldiamines) of the present invention may be made by reacting 1 mole of the corresponding aryldiamine compound with 2 moles of a selected cinnamoyl acid chloride, preferably in the presence of a solvent such as 1,4-dioxane and an acid scavenger such as pyridine and at a reaction temperature from about 20° C. to about 50° C. This reaction is illustrated by the formation of N,N'-dicinnamoyl-2,4-toluenediamine by the reaction of 1 mole of 2,4-toluenediamine with 2 moles of cinnamoyl chloride as shown in the following equation (A): ##STR3##
These aryldiamine precursors may be unsubstituted (x=O) or contain from 1 to 3 substituents (x=1 to 3) of the selected classes mentioned above. Suitable lower alkyl substituents included methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl and isobutyl groups. Corresponding alkoxy groups may be also suitable. Halo groups include fluoro, chloro, bromo, and iodo groups. Suitable aryl groups include unsubstituted phenyl groups and alkyl-substituted phenyl groups. Furthermore, these aryldiamine compounds include fused ring compounds such as unsubstituted naphthalene or alkyl-substituted napthalenes. Because of cost considerations, it is now preferred to employ various toluenediamine (x=1, R=CH 3 ) or phenylenediamine (x=O) as the aryldiamine precursors.
Representative aryldiamine compounds which may be used as precursors for the compounds of the present invention include:
ortho-phenylenediamiane
2,3-toluenediamine
2,4-toluenediamine
2,5-toluenediamine
2,6-toluenediamine
3,4-toluenediamine
3,5-toluenediamine
4,5-dimethyl-ortho-phenylenediamine
diaminonaphthalene
These cinnamoyl acid chlorides may include unsubstituted cinnamoyl groups (y=O, z=O) or contain from 1 or 2 substituents (y=1 to 2, z=1 to 2) of the selected classes mentioned above. Suitable lower alkyl substituents include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl and isobutyl groups. Corresponding lower alkoxy groups may be also suitable. Halo groups include fluoro, chloro, bromo, and iodo groups. Suitable aryl groups include unsubstituted phenyl groups and alkyl-substituted phenyl groups. It is preferred, that the same cinnamoyl group (where R' and R" are the same) be added to each amine group on the aryl diamine precursor because then only one reaction step is needed. However, it may be desirable in certain instances to employ different cinnamoyl moieties. Most preferably, it is now desired to employ unsubstituted cinnamoyl moieties (y=z=O).
Representative cinnamoyl acid chlorides which also may be used as precursors for the compounds of the present invention include:
cinnamoyl chloride
p-methyl cinnamoyl chloride
2,5-dimethoxycinnamoyl chloride
3,4-dimethoxycinnamoyl chloride
o-nitrocinnamoyl chloride
m-nitrocinnamoyl chloride
p-nitrocinnamoyl chloride
2-methyl-4-nitrocinnamoyl chloride
4-methyl-3-nitrocinnamoyl chloride
Any conventional reaction conditions employed for the reaction between an amine compound with an acid chloride are the preferred synthesis parameters for the compounds of the present inventions. However, the present invention is not intended to be limited to any particular reaction conditions or precursors. Alternatively, cinnamic acid esters or anhydrides may be employed. Advantageously and preferably, the reaction is carried out with a 2:1 mole ratio of the cinnamoyl chloride precursor(s) to the aryldiamine precursor in the presence of a suitable inert solvent and an acid scavenger. Preferred solvents include 1,4-dioxane, tetrahydrofuran, hexane and the like. Preferred acid scavengers include pyridine and triethylamine and the like. However, the use of a solvent or an acid scavenger, or both, is only desirable, but not necessary. The reaction temperature and time will both depend upon many factors including the specific reactants used. In most situations, reaction temperatures may advantageously be from about 20° C. to about 50° C. and reaction times from about 15 minutes to about 300 minutes or more may be preferred. The product may be recovered from the reaction mixture by any conventional means such as filtration, extraction or the like. The product may be further purified by conventional means such as recrystallization in an inert solvent or the like.
The compounds of the present invention are believed to possess a combination of properties which make them advantageous as UV stabilizers. These desirable properties include their white or near-white color, their non-volatility, their stability under normal storage conditions, their insolubility in water but solubility in certain organic solvents, their exceptionally strong maximum absorptivity of UV light from about 280 to about 320 nm wave lengths as well as their low order of toxicity as exemplified by the data given below in the Examples.
Also in accordance with the present invention, it has been found that the compounds of formula (I) above may be utilized as effective ultraviolet stabilizers for UV degradable organic material or in human sunscreen compositions. In practicing the use as a UV stabilizer for such organic materials, an effective stabilizing amount of one or more of these compounds is incorporated into the organic composition susceptible to UV degradation. In practicing the use as a UV stabilizer in human sunscreen composition, an effective screening amount of one or more compounds of formula (I) is incorporated into the sunscreen composition which is applied to human skin or hair. It is to be understood that the terms "effective stabilizing amount" and "effective screening amount" as used in the specification and claims herein is intended to include any amount that will prevent or retard UV radiation from either degrading the organic material incorporated therein or penetrating the human skin or hair, respectively. Of course, these amounts may be constantly changing because of possible variations in many parameters. Generally, amounts from about 0.01% to about 10%, by weight, based on the weight of the organic or carrier material to which they are added. While a detectable amount of stabilization or screening may be obtained with amounts less than 0.01%, this amount of stabilization or screening would be of little practical utility in a commercial application. Moreover, while amounts greater than 10% by weight provide effective ultraviolet stability and screening, such concentrations are undesirable because of cost and the deleterious effect which such concentrations may have on the mechanical properties of the organic composition in which the UV stabilizer is incorporated. Preferably, the stabilizer is used in an amount of from about 0.1% to about 3% by weight.
Possible organic materials which are susceptible to UV degradation and which may have the compounds of formula (I) incorporated therein as UV stabilizers include organic polymers (both thermoplastic and thermosetting polymers). Wholly synthetic polymers such as addition polymers, condensation polymers and condensation polymers crosslinked by addition polymerization may be aided with these UV stabilizers. Natural polymers such as polysaccharides, rubber and proteins may also be aided. Also, chemically modified polymers may be employed as substrates as well as other substances such as natural and synthetic light-sensitive waxes, fats and oils, emulsions which contain light-sensitive fatty substances or the abovementioned polymers.
Exemplary lists of these polymers and other substances are shown in U.S. Pat. No. 4,127,586, which issued to Rody et al on Nov. 28, 1978, and U.S. Pat. No. 3,936,418, which issued to Pond et al on Feb. 3, 1976. Both of these U.S. Patents are incorporated herein by reference in their entireties.
Any suitable carrier material which is presently used for human sunscreen compositions may have the compounds of formula (I) incorporated therein. Examples of this carrier material for sunscreens include emollients or emulsions of conventional cosmetic chemicals known in the art.
Such organic compositions and sunscreen compositions may contain further additives, pigments, colorants, stabilizers and the like. These may include antioxidants, other UV stabilizers and sunscreens, metal like.
These aryl N,N'-bis cinnamamide compounds of formula (I) may be incorporated into these organic compositions or sunscreen compositions by any convention blending technique such as melt-blending, mixing or the like. Alternatively, they may add on the surface of such materials or adfixed thereto by means of a gel or the like.
The following examples further illustrate the present invention. All parts and percentages employed therein are by weight unless otherwise indicated.
EXAMPLE 1
Preparation of N,N'-Dicinnamoyl-2,4-Toluenediamine
In a 1 liter, 4 neck, flask equipped with a mechanical stirrer, thermometer, water condenser, and dropping funnel was placed 36.9 grams (0.3 moles) 2,4-toluenediamine, 48 grams pyridine, and 150 milliliters 1,4-dioxane. The flask and its contents were then cooled to 25° C. by means of an ice-water bath. To this cooled and stirred mixture was added by means of the dropping funnel a solution of 100 grams (0.6 moles) cinnamoyl chloride in 100 milliliters 1,4-dioxane. The addition required 0.5 hr. during which time the temperature of the flask and its contents was maintained between 25°-30° C. Upon completion of the addition the contents of the flask were allowed to stir at 25°-30° C. for an additional 0.5 hr. then poured into 500 milliliters of cold water which immediately caused the precipitation of light amber color solids. The solids were collected by suction filtration, partially dried, and recrystallized from 1,4-dioxane giving 98.0 grams (85.5% ) of light lemon color crystals. Recrystallization of this material from ethyl alcohol containing powdered charcoal gave 74 grams (64.6% yield) of pure white crystals which melted at 217°-219° C.
Nuclear magnetic resonance spectroscopy and elemental analysis confirmed the product to be N,N'-dicinnamoyl-2,4-toluenediamine.
EXAMPLE 2
Preparation of N,N'-Dicinnamoyl-ortho-Phenylenediamine
The procedure of Example 1 was repeated except ortho-phenylenediamine [5.41 grams (0.05 moles)] and 7.9 grams of pyridine were placed in a flask containing 100 milliliters of 1,4-dioxane. After cooling and stirring as before, a solution of cinnamoyl chloride [16.66 grams (0.1 mole)] dissolved in 100 milliliters of 1,4-dioxane was added to the flask. Upon completion of the reaction and following the recovery and recrystallization step as before, dried buff-colored crystals weighing 10.1 grams (55% yield) were collected which had a melting point of 212.3° C.
Elemental analysis was consistent with N,N'-dicinnamoyl-ortho-phenylenediamine.
EXAMPLE 3
Preparation of N,N'-dicinnamoyl-4,5-dimethyl ortho-phenylenediamine
The procedure of Example 1 was again repeated except 4,5-dimethyl-ortho-phenylenediamine [6.81 grams (0.05 moles)] and 7.9 grams of pyridine were placed in a flask containing 100 milliliters of 1,4-dioxane. After cooling and stirring as before, a solution of cinnamoyl chloride [16.6 grams (0.1 mole)] dissolved in 100 milliliters 1,4-dioxane was added to the flask. Upon completion of the reaction and following the same recovery and recrystallization steps as before, dried white crystals weighing 10.7 grams (54% yield) were collected which had a melting point of 243.5° C.
Elemental analysis was consistent with N,N'-dicinnamoyl-4,5-dimethyl-ortho- phenylenediamine.
EXAMPLE 4
Preparation of N,N'-di(p-methylcinnamoyl)-2,4-toluenediamine
The procedure of Example 1 was repeated except that p-methyl cinnamic acid [8.0 grams (0.05 moles)] was added to the flask. Then, SOCl 2 [8.9 grams (0.075 moles)] in 30 milliliters benzene was added to form the acid chloride. Next, 2,4-toluenediamine [3.05 grams , (0.025 moles)] in 100 milliliters of benzene and 4.0 grams of pyridine was added to the flask. Upon completion of the reaction and following the recovery and recrystallization (in THF/hexane) steps, white crystals weighing 6 grams (60% yield) were collected which had a melting point of 251.7° C.
Elemental analysis was consistent with N,N'-di(p-methylcinnamoyl)-2,4-toluenediamine.
EXAMPLE 5
Preparation of N,N'-dicinnamoyl-2,3-diaminonaphthalene
The procedure of Example 1 was repeated except that 2,3-diaminonapthalene [50 grams (0.03 moles)] and 4.8 grams of pyridine were placed in a flask containing 100 milliliters of 1,4-dioxane. After cooling and stirring as before, a solution of cinnamoyl chloride [10 grams (0.06 moles)] dissolved in 55 milliliters of 1,4-dioxane was added to the flask. Upon completion of the reaction and following the recovery and recrystallization (in glacial acetic acid), white crystals weighing 7.5 grams (60% yield) were collected which had a melting point of 276.4° C.
Elemental analysis was consistent with N,N'-dicinnamoyl-2,3-diaminonaphthalene.
EXAMPLE 6
Preparation of N,N'-dicinnamoyl-3,4-toluenediamine
The procedure of Example 1 was repeated except 3,4-toluenediamine [36.9 grams (0.03 moles)] and 48 grams of pyridine were placed in a flask containing 150 milliliters of 1,4-dioxane. After cooling and as before, a solution of cinnamoyl chloride [100 grams (0.60 moles)] dissolved in 100 milliliters of 1,4-dioxane was added to the flask. Upon completion of the reaction and following the recovery and recrystallization steps as before, white crystals weighing 9.2 grams (65% yield) were collected which had a melting point of 218° C.
Elemental analysis was consistent with N,N'-dicinnamoyl-3,4-toluenediamine.
The ultraviolet light absorptivity properties of the compounds of Examples 1-6 were measured by means of a spectrophotometer and are given in Table I. A comparison is also given for paraaminobenezonic acid (PABA), which is a well known UV stabilizer. This data indicates that all of these compounds of the present invention are very good ultraviolet absorbers. The photostability of the compound of Example 1 was also measured by subjecting a solution of the compounds to the UV radiation produced by a 450 watt medium pressure mercury lamp at 17°-25° C. in a Hanovia photochemical apparatus and periodically determining its absorbance by means of a spectrophotometer. The data as shown in Table II indicates excellent photostability.
TABLE I______________________________________ Wave Length MolarExample (λ), max. Absorptivity (l/g · cm).sup.1 Absorptivity.sup.2______________________________________1 292 130.8 49,9662 282 154.8 57,2623 282 139.5 55,5394 305 152.7 62,9225 284 158.2 66,4336 282 154.8 59,443PABA 290 132.8 18,200______________________________________ .sup.1 Measured on a PerkinElmer spectrophotometer, Model No. 330. ##STR4## (also called optical density) and is an observed (experimental determined value; b = cell size; and c = concentration of compound in solvent. .sup.2 Molar Absorptivity = absorptivity (a) times molecular weight.
TABLE II______________________________________Time (hrs.) Absorbance (A) at 292 nm______________________________________0 1.310.4 1.291.2 1.272.9 1.286.3 1.26______________________________________
TOXICITY TESTS
The oral LD 50 in rats for N,N,-dicinnamoyl-2,4-toluenediamine was greater than 5 grams/Kg of body weight. No signs of toxicity nor deaths occurred at this dose, equivalent to a human ingesting approximately 350 grams of the compound. The dermal LD 50 , determined by applying a 2 g/Kg of body weight dermal dose of this compound to the backs of rabbits for a 24 hour contact period, was greater than 2 g/Kg of body weight. No deaths occurred over the 14 day observation period.
Tests to determine the inhalation LC 50 in rats, by inhalation of 200 mg of compound per liter of air for one hour, produced no deaths. The LC 50 is greater than 200 mg/l.
This compound was not a skin sensitizer at a 50% by weight concentration in guinea pigs. It was a mild skin irritant in rabbits and an eye irritant in rabbits.
In summary, this toluenediamine derivative is not considered by the Federal Hazardous Substances guidelines to be toxic by ingestion, dermal exposure, nor inhalation exposure. This is important because in the factor situation, exposure to the compound is most likely to occur by ingestion, dermal contact or by inhalation.
MUTAGENIC TEST
N,N'-dicinnamoyl-2,4-toluenediamine was analyzed for mutagenic activity using the standard short term bacterial test for genetic toxicity called the Ames Salmonella/Microsome Plate Assay. The test was conducted in five strains of Salmonella, with an without metabolic activation, at concentrations of 1, 3, 10, 30 and 100 micrograms of the compound per plate.
The compound did not induce significant mutation in any of the strains, either in the presence or absence of metabolic activation. Under the conditions of this assay, the compound is not considered mutagenic. | An aryl N,N'-bis cinnamamide compound having a formula comprising: ##STR1## wherein x equals an integer from 0 to 3; y equals an integer from 0 to 2; z equals an integer from 0 to 2; each R is individually selected from the group consisting of a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having from 1 to 4 carbon atoms, a halo group, a nitro group, an aryl group having 6 to 18 carbon atoms, and a fused unsubstituted or substituted aromatic ring when x is 2 or 3; and each R' and R" is individually selected from the group consisting of a lower alkyl group having from 1 to 4 carbon atoms, a lower alkoxy group having from 1 to 4 carbon atoms, a halo group, a nitro group or an aryl group having from 6 to 18 carbon atoms. These compounds are useful as U.V. light absorbers in plastics and cosmetics (e.g. sunscreens). | 0 |
This is a Continuation of application No. 07/708,645, filed May 31, 1993, now abandoned which in turn is a continuation-in-part of application No. 07/556,153, filed on Jul. 23, 1990, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to a cassette container case for storing a magnetic tape cassette, and more particularly to an improved cassette container case for storing a magnetic tape cassette for audio use or the like.
When storing an audio type magnetic tape cassette, the cassette is generally placed in a magnetic tape cassette container case made of a plastic material. The magnetic tape cassette has a front open portion into which a magnetic head, etc., is inserted when loading the cassette into a recording/reproducing device, the magnetic tape running across the front open portion during recording and reproduction. However, without sole way of enclosing the cassette, dust is liable to enter the cassette through the front open portion, and there is a risk that the user's fingers, etc., may contact the magnetic tape. In order to prevent such difficulties and to protect the entire cassette, a cassette container case is commonly used.
FIG. 1 shows the basic construction of a conventional cassette container case. The cassette container case 31 has a lid 32 having a pocket portion 34 for receiving a cassette 20, and a casing 35 having a pair of rotation-preventing projections 7 which are adapted to be inserted into respective shaft insertion holes 22 of the cassette 20.
In the cassette container case 31, pivot pins formed on right and left side walls of the casing 35 are fitted in corresponding through-holes formed in the right and left side walls of the pocket portion 34. With this arrangement, the lid 32 and the casing 35 can be opened and closed much like a door. The thickness of the cassette container case 31 between its walls 33 and 36 opposed respectively to the front and rear faces of the cassette 20 corresponds to the thick portion 21 of a cassette 20 in the region of its front opening. Therefore, except for the thick portion 21, the thickness l 1 of the cassette container case 31 is considerably greater than the thickness l 2 of the cassette 20.
Thus, when the cassette 20 is placed in the cassette container case 31 for storage purposes, a considerably greater storage space is required than if the cassette 20 were stored without a case. For this reason, if the user wishes to store as many cassettes 20 as possible in a limited space, for example, in an automobile, the user often refrains from using cassette container cases 31. However, if the cassette 20 is stored without the use of a cassette container case 31, dust tends to enter the cassette as described above, which results in a problem in that the recording and reproducing characteristics of the magnetic tape are degraded.
In order to overcome the above problems, the Applicant of the present invention has earlier proposed thin-type cassette container cases. (See U.S. Pat. Nos. 4,648,507 and 4,627,534).
In such a thin-type cassette container case, recesses for receiving the thick portion of the cassette at the front portion of the cassette are formed in an openable distal portion of the cassette container case.
The improved cassette container case disclosed in U.S. Pat. No. 4,627,534 will now be described with reference to FIG. 2. The cassette container case 11 shown in FIG. 2 has a lid 12 having a pocket portion 14, and a casing 15 which is pivotally connected to the lid 12 as in the conventional cassette container case. A recess 18 for receiving the thick portion 21 of a cassette 20 is formed in a wall 13 of the lid 12 opposed to the face of the cassette. Another recess 18 for receiving the thick portion 21 of the cassette is also formed in a wall 16 of the casing 15 opposed to the face of the cassette. A pair of rotation-preventing projections 7, similar to those of the conventional cassette case, and which are insertable into reel shaft insertion holes 22, are also formed on the wall 16.
The two recesses 18 are provided in the inner surfaces of the case in opposed relation to each other. Each recess 18 is shaped to receive the thick portion 21, that is, each recess has a shape (for example, a trapezoidal shape) flaring outward away from the axis of rotation (opening and closing movement) of the lid 12 and the casing 15.
Although not shown in the drawings, protrusions are formed on right and left side walls 19 of the casing 15, and respective depressions are formed in right and left side walls of the pocket portion 14 opposed to the walls 19. The protrusions are engageable in the depressions when the lid of the cassette container case 11 is closed, thereby preventing the lid from being accidentally opened during the storage of the cassette.
When the lid of the cassette container case 11 is in the closed position, the spacing between the wall 13 and the wall 16 is only slightly greater than the thickness l 2 of the cassette 20 in areas other than the thick portion 21, and the spacing between the two recesses 18 is only slightly greater than the thickness l 5 of the thick portion 21.
Therefore, the improved cassette container case 11 shown in FIG. 2 has a much smaller thickness than the earlier cassette container case, the space required for storing it is much reduced, and the improved case is very handy for carrying.
An index card 41 as shown in FIG. 3 is attached to the cassette container case 31 shown in FIG. 1, and desired data can be written on the index card 41. More specifically, the index card is positioned in such a manner that a folded portion 42 of a channel-shaped cross-section is fitted in the pocket portion 34, with a flat portion 43 laid over the flat wall 33 of the lid 32.
However, when the index card 41 is applied to the improved cassette container case 11 shown in FIG. 2, a problem is encountered. That is, since the recesses 18 are provided at the open side of the thin-type cassette container case 11, when the index card 41 is provided on the lid 12, the recess 18 formed in the lid 12 is blocked by the index card, defeating the function of the recess 18. To overcome this drawback, the present inventor has disclosed an index card 51, as shown in FIG. 3, which avoids closing the recess 18.
The index card 51 of FIG. 3 has a folded portion 52 for fitting in the pocket portion 14 similar to that of the earlier index card, but a flat portion 53 is smaller in width than the above-mentioned flat portion 43. More specifically, there is established the relationship L b <L a -L c , where L a represents the width of the flat portion 43, L b the width of the flat portion 53, and L c the depth (width) of the recess 18. With this arrangement, the recess 18 formed in the open side of the lid 12 is not closed by the index card, so that the thick portion 21 of the cassette can be received in this recess.
However, with this configuration of the index card 51, the lid 12 is exposed at opposite sides of the recess 18, and a step is formed between such exposed portion and the portion where the index card 51 is present. This produces instabilities such as rattling. Moreover, powder tends to be produced as a result of the frictional contact between the cassette 20 and the lid 12. This is not desirable from the viewpoints of quality control and appearance.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the above deficiencies, and more specifically an object of the invention is to provide a thin-type cassette container case which can stably hold a magnetic tape cassette despite the provision of recesses for receiving the thick portion of a cassette.
The above and other objects of the invention have been achieved by a cassette container case wherein a lid having a pocket portion for receiving a magnetic tape cassette is pivotally connected to a casing having rotation-preventing projections in such a manner that the lid and the casing can be opened and closed like a door, recesses for receiving a thick portion of the magnetic tape cassette are formed in open sides of the lid and casing, and an index card having no region opposed to said recess is attached to the lid.
According to another embodiment of the invention, the index card includes a flap for covering the opening of the cassette through which the tape can be accessed. Further, a trapezoidal portion is either embossed or cut-out from the index card in order to accommodate the thick portion of the cassette.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a conventional cassette container case;
FIG. 2 is a perspective view of another conventional cassette container case;
FIG. 3 is a perspective view, showing a conventional index card and an index card having a reduced width;
FIG. 4 is a developed, perspective view of an index card according to an embodiment of the present invention;
FIG. 5 is a perspective view of the index card;
FIG. 6 is a perspective view of a cassette container case having the index card attached thereto;
FIG. 7 is a perspective view showing a conventional cassette case having an index card according to another embodiment of the invention;
FIG. 8 is a side view of the FIG. 7 embodiment;
FIG. 9 is a perspective view of the index card of FIG. 8;
FIG. 10 is a perspective view of an index card according to yet another embodiment of the invention; and
FIG. 11 is a perspective view of an index card according to still a further embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of a cassette container case of the present invention will now be described with reference to the drawings.
FIG. 4 is a developed, perspective view of an index card for use in the cassette container case of a preferred embodiment of the invention. FIG. 5 is a perspective view of the index card. FIG. 6 is a perspective view of the case having the index card attached thereto. The index card in this embodiment is designed to be attached to the cassette container case 11 shown in FIG. 2, and therefore this embodiment will be explained with reference to this cassette container case 11.
As shown in FIG. 4, the index card 1 is formed from an elongated thick paper sheet cut from a paper blank, the thick paper sheet having an opening 2 of a hexagonal shape formed therethrough. The thick paper sheet is folded inwardly at portions thereof indicated by dashed lines a, b and c. The area of the opening 2 is twice that of the recess 18, and the shape of the opening 2 is determined in accordance with the shape of the recess 18. The position of the opening 2 is such that the opening 2 is disposed in registry with the recess 18 when the index card 1 is attached to the lid 12.
By folding the thick paper sheet along the dashed lines a and b, a pocket insertion portion 3 of a channel-shaped cross-section is formed as shown in FIG. 5. By folding the thick paper sheet along the dash line c, the hexagonal opening 2 is converted into an opening 2a whose area is half that of the hexagonal opening 2. The opening 2a corresponds to the recess 18. In the folded condition shown in FIG. 5, the width L b of a double flat portion 4 is substantially equal to the above-mentioned width L a .
The cassette container case 11 having the index card 1 attached thereto will now be described.
As shown in FIG. 6, the pocket insertion portion 3 of the index card 1 is inserted into the pocket 14 portion of the lid 12. As a result, the double flat portion 4 is positioned so as to be laid over the wall 13 so that the recess 18 is exposed as part of the wall 13 through the opening 2a. Therefore, when the cassette 20 is inserted into the lid 12 as indicated by an arrow in FIG. 2, one side (the upper side in FIG. 2) of the thick portion 21 passes through the opening 2a and is received in the recess 18.
In this condition, when the casing 15 is closed, the recess 18 in the casing 15 is fitted on the lower side (FIG. 2) of the cassette thickened portion 21 already held in position, and at the same time the rotation-preventing projections 7 on the casing 15 are fitted in the respective shaft insertion holes 22 of the cassette 20, thereby completing the operation of placing the cassette 20 in the casing 15. Thus, the cassette 20 is positioned by the pocket portion 14 and the recess 18, and is resiliently held by the doubled index card 1. Therefore, rattling, etc., of the cassette 20 is less likely to occur.
Although a preferred embodiment of the invention has been described above, the invention itself is not to be restricted thereto, and various modifications can be made.
For example, the flat portion 4 of the index card 1 is not limited to the doubled form, and may be in a single form. In this case, the opening 2 is beforehand formed into a trapezoidal shape corresponding to the recess 18.
Also, the opening 2 may be slightly smaller in size than the recess 18 so that when the thick portion 21 passes through the opening 2, the edge portion of the opening 2 is turned or folded toward the recess 18. In this case, part of the index card 1 is interposed between the edge portion of the thick portion 21 and the edge portion of the recess 18, thereby further restraining rattling.
As described above, in the cassette container case according to the present invention, the lid having the pocket portion is pivotally connected to the casing having the rotation-preventing projections in such a manner that the lid and the casing can be opened and closed like a door, and the index card having the opening or the open area located so as not cover the recesses formed in the open sides of the lid and the casing is attached to the lid.
With the above construction of the cassette container case of the invention, the thick portion of the cassette passes through the opening or the open area of the index card and is received in the recess. Therefore, despite the fact that the index card is attached to the cassette container case, the cassette container case can be made thin as a whole.
Further, the index card also serves as a cushioning material so that rattling of the cassette is reduced, thereby decreasing the production of unpleasant noise and frictional contact between the cassette and the case.
FIGS. 7-11 illustrate further embodiments of the present invention. FIG. 7 is a perspective view of a further embodiment showing a state in which a cassette is being accommodated in the cassette containing case according to the invention, and FIG. 8 is a side view thereof.
The basic structure of the cassette containing case 41 shown in FIGS. 7 and 8 is the same as the cassette containing case described in Japanese Utility Model Unexamined Publication No. 52782/1988. More specifically, the cassette containing case 41 shown in FIGS. 7 and 8 includes a cover 42 having a pocket 44 and a casing 45. Both the cover and the casing are pivotably attached to the case. On a wall portion 43 of the cover 42 which confronts one of the opposing surfaces of a cassette 50 is formed a recessed portion 48 for accommodating a thick portion 51 of the cassette 50, the thick portion 51 constituting the front opening of the cassette 50. Further, on a wall portion 46 of the casing 45 which confronts the other opposing surface of the cassette 50 are provided a recessed portion 48 for accommodating the thick portion 51 and a pair of reel stopper projections 67 into which reel shaft holes 52 are inserted.
Both recessed portions 48 are arranged inside the case so as to confront each other in the open position of the case. The shape of the recessed portions 48 is trapezoidal so that the thick portion 51 of the cassette can be received therein.
A feature of this embodiment is an index sheet 61 disposed along the wall of the cover 42. Specifically, the index sheet 61 extends along the walls of the pocket 44 and wall 43 of the cover 42 with a front flap 62 that stands upright widthwise at a position confronting the bent portion of the pocket 44 so as to allow the cassette front opening to be covered thereby.
As shown in FIG. 9, the index sheet 61 is such that a portion 63 that corresponds to the thick portion of the cassette in an extensive area 64 confronting the wall 43 is formed into an embossed trapezoid to accommodate the thick portions 51 of the cassette. The front flap 62 is arranged so as to extend rectangularly along the trapezoidal portion 63 with a folding line 65 as a border. The folding line 65 is bent substantially at right angle in an L-like configuration, thereby allowing the front flap 62 to cover the front opening of the cassette.
Accordingly, when the rear portion of the cassette 50 is inserted into the pocket 44 of the cover 42, the front flap 62 of the index sheet 61 can instantly be set to the front opening of the cassette. Since the front opening of the cassette is covered by the front flap 62, the magnetic tape of the cassette from being touched by the user. Further, to open the cassette containing case 41, the magnetic tape is not directly touched by a hand or fingers because the front opening of the cassette is covered by the front flap 62.
The index sheet 61 of the invention may preferably be made of a material free from dust such as paper or a plastic sheet. An index sheet provided with anti-static finish may also be used.
The application of the device is not limited to the above embodiment, but may be modified to those shown in, e.g., FIGS. 10 and 11. In the modification shown in FIG. 10, the front flap 62 for covering the front opening of the cassette is formed so that the trapezoidal portion 63 protrudes from the extensive portion 64. In this construction, a portion of the front flap 62 on opposite sides of the trapezoidal portion 63 is cutout.
In the modification shown in FIG. 11, the trapezoidal portion is cutout, and the front flap 62 is wide enough to cover the entire side length of the front opening.
The front flap 62 may be arranged by modifying the index sheet as described in the above examples, but may be embodied in other ways as well. A front flap 62 formed separately from the index sheet may be assembled or adhesively fixed to the index sheet, or may be adhesively attached to the cover 42.
As described in the foregoing, the cassette containing case according to the invention includes a cover, a casing, and a recessed portion for accommodating the thick portion of the cassette. The cover and the casing are pivotably fixed so as to be freely opened and closed. Additionally, a sheet capable of extending across the width of the case is provided in the cover to cover at least the front opening of the cassette.
As a result of this construction, not only can the thickness of the case be reduced, but also the front opening of the cassette can be covered by the sheet, thereby preventing the magnetic tape from being touched at the time of opening and closing the case. This obviates risks not only of impairment of sound quality such as dropout due to contamination, scratching, folding, or the like of the magnetic tape, but also of tape jamming and defective tape travel due to folding of the tape. | A cassette container case including a casing having rotation-preventing projections formed thereon, a lid having a pocket portion for receiving a magnetic tape cassette pivotally connected to the casing in such a manner that the lid and the casing can be opened and closed like a door, recesses for receiving a thick portion of a magnetic tape cassette being formed in open sides of the lid and casing, and an index card attached to the index card covering the lid except for a region opposed to the recess which receives the thick portion of the cassette. In another embodiment, the index card includes a flap that covers the opening of the cassette through which the tape can be accessed. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to charging devices and more particularly to a charging device for charging a battery.
[0003] 2. Description of the Prior Art
[0004] Plenty electrical appliances (especially portable electrical appliances) are powered by built-in batteries. The batteries built in the electrical appliances are of two categories, namely non-separable batteries and separable batteries. Non-separable batteries are built in the electrical appliances and are not removable. To charge non-separable batteries, it is necessary to connect the electrical appliances directly with a utility power supply network, such as an indoor electrical outlet or the interface of another power supply end. However, those electrical appliances whose batteries are running out of power have to be connected to the utility power supply network continually in order to operate, albeit at the expense of portability. Separable batteries are removable from the electrical appliances so that the batteries are charged externally and independently. The advantage of separable batteries is that they are highly replaceable. For instance, when separable batteries of electrical appliances have run out of power, if another battery with appropriate specification is fully charged beforehand, it will be feasible to change the batteries instantly to thereby facilitate the subsequent use and portability of the electrical appliances. However, to meet the aforesaid requirement, the separable batteries require a self-contained charger for use in charging.
[0005] A commercially available charger essentially comprises a slot which a battery can be inserted into and a charging terminal fixed in place inside the slot. The charging terminal is connected to a power circuit built in a charger, and the power circuit is further connected to a utility power supply network or an interface of another power supply end. The charging terminal of the battery and the charging terminal of the slot correspond in position to each other. A user can insert the battery into the slot such that the charging terminal of the battery matches and connects with the charging terminal of the charger to thereby form a circuit, and therefore the battery can be charged. It is important that the charging terminal of the battery is fully and firmly connected to the charging terminal of the charger to thereby prevent power interruption which might otherwise occur because of loose contact or poor contact. To this end, a conventional charger is designed in a manner that a clamping structure disposed inside the slot can generate a large clamping force (under which, for example, a battery is snugly held by the clamping structure inside the slot and therefore fixed in place) or a fixing mechanism (such as a snap-engaging element for holding a battery by snap-engagement) is optionally disposed inside the slot.
SUMMARY OF THE INVENTION
[0006] To allow a charging terminal of a battery to be fully and firmly connected to a charging terminal of a conventional charger, the conventional charger is designed in a manner that a clamping structure disposed inside a slot can generate a large clamping force or a fixing mechanism is optionally disposed inside the slot. However, the aforesaid advantage is achieved at the expense of ease of use. For instance, it is time-consuming and laborious for the user to take out the battery, as the user must take out the battery by both hands, with one hand pressing on the charger and the other hand generating a pulling force for taking the battery out. Alternatively, the user has to perform a specific loosening operation on the fixing mechanism in order to take the battery out. In view of this, the present invention provides a charging device whereby not only can a battery be firmly inserted into the charging device but it is easy to insert and take out the battery.
[0007] In an embodiment of the present invention, a charging device comprises a charging base and at least one hook portion. The charging base has a receiving chamber for receiving a battery. The receiving chamber comprises a first sidewall. The first sidewall has a first side and a second side opposing the first side. The hook portion is disposed on the first sidewall, positioned proximate to the first side of the first sidewall, and adapted to fix the battery in place. When the battery begins to rotate under an applied force to thereby disconnect with the hook portion, the fulcrum of the rotating battery is positioned proximate to the second side of the first sidewall.
[0008] The receiving chamber further comprises a second sidewall. The second sidewall connects with the second side of the first sidewall and tilts. The second sidewall has a shortest distance between an end of an opening of the receiving chamber and an axis of the receiving chamber and has another shortest distance between an end of a bottom of the receiving chamber and the axis of the receiving chamber, wherein the former distance is larger than the latter distance.
[0009] In an embodiment of the present invention, the charging device further comprises at least two hook portions spaced apart from each other.
[0010] In an embodiment of the present invention, the charging base further comprises a charging terminal disposed on the first sidewall. The charging base further comprises a limiting rib. The limiting rib is disposed on the first sidewall of the receiving chamber. The limiting rib comprises a first end adjacent to an opening of the receiving chamber and a second end adjacent to the charging terminal. The height of the limiting rib increases gradually relative to the first sidewall in the direction from the first end to the second end. The second end of the limiting rib is positioned proximate to the charging terminal.
[0011] In an embodiment of the present invention, the charging base further comprises a charging terminal fixing portion disposed on the first sidewall of the receiving chamber. The charging terminal fixing portion comprises two spaced-apart lateral plates, a top plate and a guiding baffle. The two lateral plates are perpendicularly connected to the first sidewall. The top plate is connected to an end of each of the two lateral plates perpendicularly connected to the first sidewall, wherein the ends of the two lateral plates point away from the first sidewall, with the charging terminal disposed between the two lateral plates and the top plate, wherein the second end of the limiting rib is connected to the lateral plates and positioned proximate to an opening of the receiving chamber. The guiding baffle is disposed on the top plate.
[0012] In an embodiment of the present invention, the hook portion comprises a resilient arm and a protruding portion. The resilient arm has an end connected to the bottom of the receiving chamber. The resilient arm has another end corresponding in position to the first sidewall. Therefore, the other end of the resilient arm undergoes resilient displacement relative to the first sidewall. The protruding portion is disposed at the other end of the resilient arm.
[0013] The resilient arm comprises a first segment and a second segment connected to the first segment, and the first sidewall dents to form a way-giving recess, with the first segment connecting with bottom of the receiving chamber, the second segment corresponding in position to the way-giving recess, and the protruding portion being disposed at the second segment.
[0014] The protruding portion comprises an upward sloping surface facing an opening of the receiving chamber. The protruding portion comprises a downward sloping surface facing the bottom of the receiving chamber.
[0015] In conclusion, the present invention provides a charging device which comprises a charging base with a receiving chamber and a hook portion such that a user can put a battery in the receiving chamber easily to allow the battery to be fully and firmly engaged with the charging base and the hook portion, thereby preventing power interruption which might otherwise occur because of loose contact or poor contact. To take out the battery, the user rotates the battery slightly about a fulcrum to thereby detach the battery from the hook portion and take out the battery freely. A point of the bottom of the receiving chamber is in contact with a base angle of the battery and functions as the fulcrum. Accordingly, it is convenient, quick and easy for the user to operate the charging device of the present invention.
[0016] The features and advantages of the present invention are detailed hereinafter with reference to the preferred embodiments. The detailed description is intended to enable a person skilled in the art to gain insight into the technical contents disclosed herein and implement the present invention accordingly. In particular, a person skilled in the art can easily understand the objects and advantages of the present invention by referring to the disclosure of the specification, the claims, and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic view of a charging device according to an embodiment of the present invention;
[0018] FIG. 2 is a cross-sectional view of a charging base and a hook portion according to the embodiment of the present invention;
[0019] FIG. 3 is a partial cross-sectional view of the hook portion according to the embodiment of the present invention;
[0020] FIG. 4 is a cross-sectional view of the charging base and the hook portions taken at another angle according to the embodiment of the present invention;
[0021] FIG. 5 is a schematic view of a battery which matches the charging device;
[0022] FIG. 6 is a schematic view of the battery inserted into the charging base;
[0023] FIG. 7 is a partial cross-sectional view of the hook portion and the battery which are snap-engaged with each other;
[0024] FIG. 8 is a partial cross-sectional view of a guiding baffle and the battery which match each other; and
[0025] FIG. 9 is a schematic view of the process of taking the battery out of the charging base.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] Referring to FIG. 1 , there is shown a schematic view of a charging device 10 according to an embodiment of the present invention. In this embodiment, the charging device 10 has two charging bases 100 , but the present invention is not limited thereto. In another embodiment, the charging device has one or at least three charging bases.
[0027] FIG. 2 a cross-sectional view of the charging base 100 and a hook portion 200 according to the embodiment of the present invention. Referring to FIG. 1 and FIG. 2 , in this embodiment, the charging device 10 further comprises the hook portions 200 , and the charging bases 100 each have therein two hook portions 200 , but the present invention is not limited thereto. In another embodiment, each charging base has one or at least three hook portions. The charging base 100 has a receiving chamber 110 for receiving a battery applicable to the charging device 10 . The receiving chamber 110 comprises a first sidewall 111 , a second sidewall 112 , a third sidewall 113 and a fourth sidewall 114 . The first sidewall 111 has a first side 1111 and a second side 1112 opposite the first side 1111 . The second sidewall 112 connects with the second side 1112 of the first sidewall 111 . The third sidewall 113 is opposite the first sidewall 111 . The fourth sidewall 114 connects with the first side 1111 of the first sidewall 111 .
[0028] FIG. 3 is a partial cross-sectional view of the hook portion 200 according to the embodiment of the present invention. Referring to FIG. 2 and FIG. 3 , the hook portion 200 fixes the battery in place. In this embodiment, the two hook portions 200 are disposed on the first sidewall 111 and positioned proximate to the bottom of the receiving chamber 110 . The two hook portions 200 are positioned proximate to the first side 1111 of the first sidewall 111 . Therefore, the two hook portions 200 are closer to the fourth sidewall 114 than the second sidewall 112 . The two hook portions 200 are spaced apart from each other, with one hook portion 200 closer to the fourth sidewall 114 than the other hook portion 200 is. The hook portions 200 each comprise a resilient arm 210 and a protruding portion 220 . One end of the resilient arm 210 connects with the bottom of the receiving chamber 110 . The other end of the resilient arm 210 corresponds in position to the first sidewall 111 . The protruding portion 220 is disposed at the other end of the resilient arm 210 . In this embodiment, the resilient arm 210 comprises a first segment 211 and a second segment 212 which connect with each other. The first segment 211 and the second segment 212 together form an L-shaped structure. The first segment 211 connects with the bottom of the receiving chamber 110 . The second segment 212 corresponds in position to the first sidewall 111 . The protruding portion 220 is disposed at the second segment 212 and positioned distal to one end of the first segment 211 . The protruding portion 220 protrudes in the direction away from the first sidewall 111 . In this embodiment, the first sidewall 111 dents to form two way-giving recesses 1113 . The second segments 212 of the resilient arms 210 of the two hook portions 200 correspond in position to the two way-giving recesses 1113 , respectively. In another embodiment, there is only one way-giving recess, and the way-giving recess corresponds in position to one or more hook portions. The second segment 212 of the resilient arm 210 undergoes resilient displacement relative to the first sidewall 111 to the extent allowed by the limit of the resilience of the material which the resilient arm 210 is made of. The way-giving recesses 1113 provide the way-giving space required for the resilient displacement of the resilient arm 210 . Referring to FIG. 3 , in this embodiment, the protruding portion 220 comprises an upward sloping surface 221 and a downward sloping surface 222 . The upward sloping surface 221 of the protruding portion 220 faces the opening of the receiving chamber 110 . The downward sloping surface 222 of the protruding portion 220 faces the bottom of the receiving chamber 110 .
[0029] Referring to FIG. 4 , there is shown a cross-sectional view of the charging base 100 and the hook portions 200 taken at another angle according to the embodiment of the present invention. FIG. 4 differs from FIG. 2 by an angle of view of 90 degrees. In this embodiment, the second sidewall 112 tilts such that an included angle is formed between the second sidewall 112 and the perpendicular direction of the bottom of the receiving chamber 110 . The second sidewall 112 tilts slightly upward and outward (i.e., leftward in FIG. 4 ). The second sidewall 112 has the shortest distance D between one end of the opening of the receiving chamber 110 and the axis of the receiving chamber 110 . The second sidewall 112 has the shortest distance D′ between one end of the bottom of the receiving chamber 110 and the axis of the receiving chamber 110 . Distance D is larger than distance D′. In this embodiment, the fourth sidewall 114 also tilts such that an included angle is formed between the fourth sidewall 114 and the perpendicular direction of the bottom of the receiving chamber 110 . The fourth sidewall 114 tilts slightly upward and outward (i.e., rightward in FIG. 4 ). The shortest distance of the fourth sidewall 114 between one end of the opening of the receiving chamber 110 and the axis of the receiving chamber 110 is larger than the shortest distance of the fourth sidewall 114 between one end of the bottom of the receiving chamber 110 and the axis of the receiving chamber 110 . Therefore, the width of the opening between the second sidewall 112 and the fourth sidewall 114 is slightly larger than the width of the bottom between the second sidewall 112 and the fourth sidewall 114 . In another embodiment, the fourth sidewall does not tilt such that the fourth sidewall is perpendicular to the bottom of the receiving chamber. Referring to FIG. 4 , both the two hook portions 200 are disposed to the right of the axis such that the two hook portions 200 are closer to the fourth sidewall 114 than the second sidewall 112 . In another embodiment, there is only one hook portion, and the hook portion is disposed to the right of the axis. To enhance the stability of the battery fixed in place by the hook portion, it is feasible to increase the width of the hook portion and the protruding portion, wherein the width is measured horizontally as shown in FIG. 4 .
[0030] Referring to FIG. 2 , the charging base 100 further comprises a limiting rib 130 , a charging terminal (not shown) and a charging terminal fixing portion 140 . The charging terminal of the charging base 100 is fixed in place by the charging terminal fixing portion 140 . The charging terminal of the charging base 100 and the charging terminal of the battery correspond in position to each other, match each other, and connect with each other. The structures of charging terminals are understandable to persons skilled in the art and therefore are not reiterated herein. The charging terminal fixing portion 140 is disposed on the first sidewall 111 of the receiving chamber 110 . The charging terminal fixing portion 140 comprises two spaced-apart lateral plates 141 , a top plate 142 and a guiding baffle 143 . The two lateral plates 141 are perpendicularly connected to the first sidewall 111 . The top plate 142 connects with one end of each of the two lateral plates 141 , wherein the one end of each of the two lateral plates 141 faces away from the first sidewall 111 . A receiving space is formed between the two lateral plates 141 and the top plate 142 . The charging terminal of the charging base 100 is received in and fixed to the receiving space such that the charging terminal of the charging base 100 is disposed between the two lateral plates 141 and the top plate 142 and positioned proximate to the first sidewall 111 . The guiding baffle 143 is disposed on the top plate 142 and protrudes in the direction away from the first sidewall 111 . In this embodiment, the guiding baffle 143 is positioned proximate to one of the lateral plates 141 . A gap 144 is defined between the guiding baffle 143 and the top plate 142 with reference to the other lateral plates 141 . In this embodiment, the limiting rib 130 is disposed on the first sidewall 111 . The limiting rib 130 comprises a first end 131 and a second end 132 . The first end 131 is positioned proximate to the opening of the receiving chamber 110 . The second end 132 connects with the charging terminal fixing portion 140 (i.e., the second end 132 is positioned proximate to the charging terminal of the charging base 100 .) The height of the limiting rib 130 increases gradually relative to the first sidewall 111 in the direction from the first end 131 to the second end 132 . Therefore, the top surface of the limiting rib 130 tilts relative to the first sidewall 111 . The first end 131 is positioned at the lowest point of the top surface of the limiting rib 130 relative to the first sidewall 111 . The second end 132 is positioned at the highest point of the top surface of the limiting rib 130 relative to the first sidewall 111 . The second end 132 is connected to the lateral plates 141 and positioned proximate to the opening of the receiving chamber 110 . In this embodiment, the limiting ribs 130 are in the number of two and are spaced apart from each other. The limiting ribs 130 are spaced apart such that the charging terminal of the battery can pass through the space between the limiting ribs 130 . The two limiting ribs 130 correspond in position to the two lateral plates 141 , respectively, and therefore the second ends 132 of the two limiting ribs 130 are connected to the two lateral plates 141 , respectively, and positioned proximate to the opening of the receiving chamber 110 . In another embodiment, there is only one limiting rib, and the limiting rib connects with one of the two lateral plates.
[0031] Referring to FIG. 5 , there is shown a schematic view of a battery 300 which matches the charging device 10 according to the embodiment of the present invention. The battery 300 comprises a first surface 301 , a second surface 302 , a third surface (not shown) and a fourth surface 304 . The second surface 302 and the fourth surface 304 flank the first surface 301 . The third surface is opposite the first surface 301 . The battery 300 further comprises a charging terminal 310 , a guiding block 320 , a limiting oblique surface 330 and two engaging blocks 340 . The charging terminal 310 , the guiding block 320 , the limiting oblique surface 330 and the two engaging blocks 340 are disposed on the first surface 301 of the battery 300 . The charging terminal 310 is embedded under the limiting oblique surface 330 . The two engaging blocks 340 are disposed at the bottom of the battery 300 . The guiding block 320 is disposed between the charging terminal 310 and the two engaging blocks 340 . The charging terminal of the charging base 100 corresponds in position to the charging terminal 310 . The guiding baffle 143 corresponds in position to the guiding block 320 . The two limiting ribs 130 correspond in position to the limiting oblique surfaces 330 , respectively. The two hook portions 200 correspond in position to the two engaging blocks 340 , respectively. In this embodiment, the engaging blocks 340 , which the hook portions 200 correspond in position to, are hexahedrons. In another embodiment, depending on the structure difference between the engaging blocks for the battery (for example, the engaging blocks each have an upward sloping surface and/or downward sloping surface corresponding in position to the protruding portion of the hook portion), the protruding portion of the hook portion has an upward sloping surface, a downward sloping surface, or none.
[0032] FIG. 6 is a schematic view of the battery 300 inserted into the charging base 100 according to the embodiment of the present invention. Referring to FIG. 2 , FIG. 5 and FIG. 6 , to put the battery 300 into the charging base 100 for charging, a user aligns the first surface 301 , the second surface 302 and the fourth surface 304 of the battery 300 with the first sidewall 111 , the second sidewall 112 and the fourth sidewall 114 of the receiving chamber 110 , respectively, and then allows the battery 300 to fall under its own weight into the receiving chamber 110 .
[0033] FIG. 7 is a partial cross-sectional view of the hook portion 200 and the engaging block 340 of the battery 300 which are snap-engaged with each other. Referring to FIG. 2 , FIG. 5 and FIG. 7 , when the battery 300 falls under its own weight into the receiving chamber 110 and the engaging block 340 comes into contact with the protruding portion 220 , the upward sloping surface 221 of the protruding portion 220 spreads the stress passed by the engaging block 340 to the protruding portion 220 such that the stress component exerted on the protruding portion 220 goes in a direction perpendicular to the first sidewall 111 . Therefore, the first segment 211 of the resilient arm 210 undergoes resilient displacement toward the way-giving recesses 1113 of the first sidewall 111 , and the protruding portion 220 moves toward the first sidewall 111 to thereby give way to the engaging block 340 . After the engaging block 340 has moved downward and passed the protruding portion 220 , the resilient arm 210 moves resiliently, under a resilient restoring force thereof, away from the first sidewall 111 to therefore allow the protruding portion 220 to move away from the first sidewall 111 and engage with the top end of the engaging block 340 . Referring to FIG. 7 , in the aforesaid state, the hook portion 200 and the engaging block 340 are engaged with each other such that the battery 300 is firmly held in the receiving chamber 110 . Therefore, even if the charging device 10 is turned upside down, the battery 300 will not get detached and fall under its own weight.
[0034] During the process in which the battery 300 falls under its own weight into the receiving chamber 110 , the limiting oblique surface 330 comes into contact with the limiting ribs 130 first, and the gradient of the limiting oblique surface 330 equals the gradient of the top surface of the limiting rib 130 , and in consequence the limiting oblique surface 330 moves along the limiting ribs 130 to therefore allow the charging terminal 310 between the two limiting ribs 130 to ascend gradually and get aligned with the charging terminal of the charging base 100 .
[0035] FIG. 8 is a partial cross-sectional view of the guiding baffle 143 and the battery 300 which match each other. Referring to FIG. 2 , FIG. 5 and FIG. 8 , when the limiting oblique surface 330 moves along the limiting rib 130 to cause the charging terminal 310 to ascend gradually and get aligned with the charging terminal 310 of the charging base 100 , the guiding block 320 comes into contact with the guiding baffle 143 . Furthermore, due to the aforesaid structure-based guiding relationship between the guiding block 320 and the guiding baffle 143 , during the movement of the guiding block 320 toward the bottom of the receiving chamber 110 , the guiding block 320 tilts leftward (i.e., in the direction shown in FIG. 8 ) slightly to therefore abut against the gap 144 between the guiding baffle 143 and the top plate 142 . During the aforesaid process, the charging terminal 310 of the battery 300 is guided to be aligned with and inserted into the charging terminal 310 of the charging base 100 .
[0036] FIG. 9 is a schematic view of the process of taking the battery 300 out of the charging base 100 . Referring to FIG. 2 , FIG. 5 and FIG. 9 , in this embodiment, the battery 300 rotates under an applied force to thereby disconnect from the hook portion 200 . The fulcrum of the rotating battery 300 is positioned proximate to the second side 1112 of the first sidewall 111 and the second sidewall 112 . After the battery 300 has been disposed inside the receiving chamber 110 fully, a second surface base angle 3021 (shown in FIG. 5 ) of the battery 300 is located at the bottom of the receiving chamber 110 and positioned proximate to the second sidewall 112 . At the point in time when the user is going to take the battery 300 out of the charging base 100 , the fulcrum is located at a point of the bottom of the receiving chamber 110 , wherein the point of the bottom of the receiving chamber 110 is in contact with the second surface base angle 3021 . The user applies a small force for rotating the battery 300 clockwise (i.e., in the direction shown in FIG. 9 ) such that the two engaging blocks 340 are detached from the hook portion 200 . When the user applies the force, the second surface base angle 3021 of the battery 300 presses on the bottom of the receiving chamber 110 , and the second surface 302 of the battery 300 tilts toward the second sidewall 112 of the receiving chamber 110 . Since the second sidewall 112 tilts, the second sidewall 112 does not impede the tilting of the second surface 302 of the battery 300 . Furthermore, a fourth surface base angle 3041 (shown in FIG. 5 ) of the battery 300 rotates clockwise, and the two engaging blocks 340 exert a stress upon the protruding portion 220 . The downward sloping surface 222 of the protruding portion 220 spreads the stress such that the resilient arm 210 moves toward the first sidewall 111 to thereby allow the two engaging blocks 340 to move upward and pass the protruding portion 220 . After the two engaging blocks 340 have passed the protruding portion 220 , the battery 300 gets disengaged from the charging device 10 such that the user can take the battery 300 out of the receiving chamber 110 freely. In the course of the rotation of the battery 300 , a specific point of the receiving chamber 110 functions as the fulcrum and is subjected to a downward stress (which originates from the downward component of a force exerted by the user upon the battery 300 ), and therefore the user is able to press on the charging device 10 while applying a rotating force under which the two engaging blocks 340 rotate and escape from the hook portion 200 . As a result, the user can perform the aforesaid operation single-handedly to take out the battery 300 conveniently, quickly and easily, thereby dispensing with the hassles of pressing on the charging device 10 by one hand and pulling out the battery 300 by the other hand.
[0037] The present invention is disclosed above by preferred embodiments. However, persons skilled in the art should understand that the preferred embodiments are illustrative of the present invention only, but should not be interpreted as restrictive of the scope of the present invention. Therefore, slight changes and modifications made to the aforesaid embodiments should fall within the scope of the present invention. Accordingly, the legal protection for the present invention should be defined by the appended claims. | A charging device including a charging base and at least one hook portion is provided. The charging base has a receiving chamber for receiving a battery. The receiving chamber includes a first sidewall. The first sidewall has a first side and a second side opposing the first side. The hook portion is disposed on the first sidewall, positioned proximate to the first side of the first sidewall, and adapted to fix the battery in place. When the battery begins to rotate under an applied force and therefore disconnect from the hook portion, the fulcrum of the rotating battery is positioned proximate to the second side of the first sidewall. The battery can be firmly inserted into the charging device. It is easy to insert and take out the battery. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61/451,875, filed Mar. 11, 2011, entitled “Pivoting Cutting Elements for Projectiles,” the disclosure of which is hereby incorporated by reference herein in its entirety.
INTRODUCTION
Mechanical broadhead arrowheads (“mechanical broadheads”) are used for hunting and are configured to expand upon impact with the hide or skin of a target animal. This expansion increases the cutting diameter of the broadhead as it penetrates the target, ideally resulting in more humane kills. Many mechanical broadheads include one or more blades pivotably engaged with an arrowhead body proximate a rear portion of the blade. Leading contact edges of each blade are positioned towards the front of the arrowhead and contact the hide or skin of a target as the arrowhead tip penetrates the hide or skin surface. This contact compels pivoting movement of each blade, thus extending the blades away from the body of the arrowhead. This pivoting movement exposes a sharp inner edge of the blade that cuts the tissue of the target. Once open, the blades are forced through the hide or skin of the target as the projectile travels further into the target. As a result, known mechanical broadheads lose significant kinetic energy as the extended blades penetrate the hide. This problem is exacerbated on larger targets like big game, targets with thick hide or hair, or when the projectile contacts the target proximate bone. Indeed, if the leading edges contact bone proximate the outer hide (for example, the ribs), the blades may open prior to significant penetration of the arrow into the target, thus reducing lethality.
Another type of mechanical broadhead 100 is depicted in FIGS. 1A and 1B . The broadhead 100 may be attached to an arrow shaft, via a threaded connection 106 . The broadhead 100 includes a leading arrowhead or tip 104 and two or more blades 106 located within a slot 108 . The blades 106 include a lever portion 110 and a cutting portion 112 . A leading edge 110 a of the lever portion 110 and a cutting surface 112 a of the cutting portion 112 are sharpened. The blades 106 are pivotably connected to a body 114 of the broadhead 100 at a pivot connection proximate a rear portion of the blade 106 . A retention member 116 holds the blades 106 in the closed position, as depicted in FIG. 1A .
When the broadhead 100 first penetrates a target, the arrowhead 104 and the body 114 form a puncture wound within the target. As the broadhead 100 further penetrates the target, the leading edge 110 a of the lever portion 110 contacts the hide. Under desirable conditions, the force applied by this contact against the lever portion 110 compels the blades 106 to pivot, thus exposing the cutting edges 112 a of the cutting portion 112 . This pivoting P breaks the retention member 116 and the blades 106 open to the position depicted in FIG. 1B . There is a risk, however, that the broadhead 100 may not open as desired. Since the arrowhead 104 forms only a puncture wound as it penetrates the target, the leading edges 110 a of the lever portions 110 are sharpened, allowing those elements to cut the tissue of the target. Should the blades 106 fail to open (due to lack of contact with denser muscle or bone), the broadhead 100 should still inflict a degree of damage to the target. This damage is not, however, as significant as damage inflicted by the exposed cutting portions 112 . Accordingly, further improvements of mechanical broadheads are still desirable.
SUMMARY
In one aspect, the technology relates to a blade system for a projectile, the blade system including: a body having a front portion and a rear portion and an axis extending axially from the front portion to the rear portion; a blade pivotably secured to the body, wherein the blade includes: an outer cutting edge; an inner cutting edge; and a lever proximate a rear portion of the blade, wherein an application of a force to the lever pivots the blade from a closed position toward an open position, wherein the lever comprises an unsharpened leading edge. In an embodiment, the body is adapted to be secured to at least one of an arrow shaft and an arrowhead. In another embodiment, the body is integral with at least one of an arrow shaft and an arrowhead. In yet another embodiment, when in the closed position, the inner cutting edge is located proximate the axis. In still another embodiment, the body defines a slot, wherein when in the closed position, the inner cutting edge is located within the slot and the outer cutting edge is exposed.
In another embodiment of the above aspect, when in the open position, the inner cutting edge extends substantially orthogonal from the axis. In another embodiment, the blade system further includes a retention element for releasably holding the blade in the closed position. In yet another embodiment, the blade system of claim 1 , further includes a breakable retention member, and the blade includes a notch, wherein the retention member is located in the notch when the blade is in the closed position. In still another embodiment, the retention member is adapted to break when the blade moves from the closed position to an intermediate position. In another embodiment, the blade includes a plurality of blades. In another embodiment, the blade system includes a spring for biasing the blade toward the open position.
In another aspect, the technology relates to an arrow including the blade system described herein. In another aspect, the technology relates to an arrowhead including the blade system described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
There are shown in the drawings, embodiments which are presently preferred, it being understood, however, that the technology is not limited to the precise arrangements and instrumentalities shown.
FIGS. 1A-1B are rear perspective views of a prior art mechanical broadhead, in a closed position and an open position, respectively.
FIGS. 2A-2C are rear perspective views of a mechanical broadhead in a closed position, an intermediate position, and an open position, respectively.
FIG. 3 is a top view of the mechanical broadhead of FIGS. 2A-2C .
DETAILED DESCRIPTION
FIGS. 2A-2C are partial perspective views of an arrow having a mechanical broadhead or expandable blade system 200 . Although the following embodiments of the expandable blade system are described in the context of arrows, the technologies described herein may also be incorporated into bolts or quarrels for crossbows or for other types of substantially elongate projectiles launched from other implements. The figures depict the blade system 200 in a closed position ( FIG. 2A ), an intermediate position ( FIG. 2B ), and an open position ( FIG. 2C ). In the figures, the blade system 200 includes a body 214 that substantially surrounds an arrow shaft 202 , but other embodiments are contemplated. For example, the blade system may be an element that is integral with the arrow shaft. In another embodiment, the rear portion of the blade system body may be secured to a front end of an arrow shaft with a threaded, press fit, and/or chemical adhesive connection. An arrowhead or tip may be secured to a front portion of the body with a similar or different connection. In another embodiment, the blade system may be integral with an arrowhead, such that the arrowhead/blade unit may be secured to a front end of the arrow shaft. In still another embodiment, the blade system may be completely integrated with the arrow shaft.
Returning to the figures, the body 214 includes a front portion 214 a , a rear portion 214 b , and an axis A. In the depicted embodiment, the front portion 214 a is located just beyond a pivot point (defined by an axis B) of the blades 206 . In alternative embodiments, the front portion of the body may extend closer to or to touch an arrowhead. Each blade 206 includes a lever portion 210 and a cutting portion 212 , which may be formed as a unitary part or discrete from each other. In the latter embodiment, the lever portion may be secured to the cutting portion with mechanical and/or chemical fasteners. In this case, the body 214 defines a slot 222 or recess for receiving an inner edge 212 a of the cutting portion 212 of the blade 206 when the blade 206 is in the closed or non-deployed position. An outer edge 212 b of the cutting portion 212 projects away from the axis A, so as to be exposed. The distance from the outer edge 212 b of the cutting portion 212 to the axis A increases as a distance from the arrowhead 204 increases. The outer edge 212 b may define a notch 218 configured to receive a retention member 216 or other element when the blade 206 is in the closed position. The blade 206 may also define a number of through-holes 206 a or openings that reduce the weight of the blade 206 . In the depicted embodiment, both the inner edge 212 a and the outer edge 212 b are sharp to facilitate cutting of the target. In other embodiments, only the outer edge of the blade may be sharp though this may limit the cutting ability of the blades when deployed. The blade 206 is connected at a pivot pin proximate the rear portion of the blade 206 . Also located near a rear portion of the blade 206 is a lever portion 210 . When a force is applied to the lever portion 210 (as described in more detail below), the blade 206 is urged to pivot about the axis B defined by the pivot pin. In the embodiment depicted in FIGS. 2A-2C , a leading edge 210 a of the lever portion 210 is not sharp.
Operation of the depicted blade system 200 is described below, again in conjunction with FIGS. 2A-2C . FIG. 2A depicts the blade system 200 in the closed position. In the closed position, the inner edges 212 a of each blade 206 are located proximate and substantially parallel to the axis A of the body 214 , within the slots 222 . The retention member 216 is located within the notches 218 so as to hold the leading tips 220 of the blades 206 in the closed position. During aiming, release, flight, and initial penetration of the arrow into the target, the blade system 200 is in the closed position. Initial penetration of the arrow begins with penetration of the arrowhead 204 into the hide of a target animal. As the arrowhead 204 travels further into the hide, the sharp outer edges 212 b of the blades 206 cut the hide and outer muscles of the animal. This is a particular advantage over other expanding broadheads that do not have exposed outer blade edges. In such broadheads, initial penetration of the arrow causes only a puncture wound, prior to opening of the blade system. In the depicted embodiment however, the outer edges 212 b of the blades 206 cause a cutting wound during initial penetration. This increases the initial lethality of the arrow strike, generally resulting in a cleaner, more humane kill.
FIG. 2B depicts the blade system 200 in an intermediate position. This intermediate position may be defined as any position between the closed position and the open position, described below. In general, the intermediate position may be any position in which the blades 206 are located, after rupture of the retention element 216 , but prior to reaching the open position. The initial penetration phase ends when the forward advancement of the arrow causes the lever portions 210 to contact the outer hide, muscle, or bone of the target animal. As the arrow continues to move forward, the force applied by the hide, muscle, or bone against the lever portions 210 forces those elements backward, thus pivoting P open the blades 206 . Once the blades 206 pivot P sufficiently, the retention member 216 ruptures or breaks, allowing the leading tips 220 to protrude beyond an outer diameter of the arrowhead 204 . Unsharpened leading edges 210 a of the lever portions 210 help ensure movement of the lever portions 210 , as opposed to further cutting that may occur with sharpened leading edges of the levers of prior art systems. As the leading tips 220 of the blades 206 contact the muscle tissue, the blades 206 open rapidly while advancement of the arrow continues. Further opening of the blades 206 exposes a greater length of the inner edge 212 a to the internal muscular structure, organs, etc., again increasing the lethality of the shot. In certain instances, due to the length of the blades 206 , the blades 206 may penetrate beyond the ribs of a target animal. Once the lever portion 210 contacts the rib bones, expansion of the blades begins within the chest cavity of the target animal, causing considerable damage therein.
FIG. 2C depicts the blade system 200 in a fully-open or deployed position. This open position may be defined by the furthest range of rotation of the blades 206 . Contact between the blades 206 and the blade system body 214 (in this case a rear portion of the slots 222 ) may limit the final open position of the blades 206 . FIG. 3 depicts a top view blade system 200 of FIGS. 2A-2C . In certain embodiments, the open position may be reached when the inner edge 212 a of the blades 206 are at an angle α approximately orthogonal to the axis A of the body 214 . In alternative embodiments, the inner edges 212 a of the blades 206 may be at an angle α of about 80° to about 100°. Other ranges are contemplated. Of course, the blades 206 need not reach the full open position during penetration of the target, although the force of penetration and the pivoting movement P of the blades 206 make this likely.
Materials for the blade systems disclosed herein may be those known in the art. For example, the body may be manufactured of injection molded robust plastics such as those used typically used to manufacture arrow shafts. Additionally, the bodies may be made of lightweight aluminum or other metals. The blades may be manufactured of ceramic form, ceramic, or ceramic composites, or from high density plastics. More desirable, however, may be blades made from durable metals such as steel, stainless steel, titanium, brass, etc. Other non-corrosive materials may be utilized as desired for a particular application. Additionally, the blade systems described herein may include one, two, three, or more blades, blades having different lengths, or multiple rows of blades to open at different depths within a target. In that regard, the total number of blades utilized may be limited by projectile size, geometry, and/or weight, or other factors apparent to a person of skill in the art. The individual blades may have serrated or smooth cutting edges. While blade systems having outer cutting edges that project outward from the arrow shaft may be more desirable, embodiments having outer edges closer to the arrow shaft (that is, thinner blades) are also contemplated. The lever is but one mechanism that could be used to cause the blades to deploy after penetration. An alternative opening mechanism includes one or more springs that bias the blades into a deployed position. A catch may release the blade upon sufficient penetration, thus allowing the spring to deploy the blade.
While there have been described herein what are to be considered exemplary and preferred embodiments of the present technology, other modifications of the technology will become apparent to those skilled in the art from the teachings herein. The particular methods of manufacture and geometries disclosed herein are exemplary in nature and are not to be considered limiting. It is therefore desired to be secured in the appended claims all such modifications as fall within the spirit and scope of the technology. Accordingly, what is desired to be secured by Letters Patent is the technology as defined and differentiated in the following claims, and all equivalents. | A blade system for a projectile includes a body having a front portion and a rear portion and an axis extending axially from the front portion to the rear portion. At least one blade is pivotably secured to the body. The blade includes an outer cutting edge and an inner cutting edge. The blade also includes a lever proximate a rear portion of the blade. An application of a force to the lever, for example as the lever contacts the skin, hide, or bone of an animal, pivots the blade from a closed position toward an open position. The lever has an unsharpened leading edge to prevent cutting of the target animal tissue to help ensure pivoting of the blade. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to utilization of camera properties in image processing. The invention especially, but not necessarily, relates to improvement of the quality of an image produced by a digital camera.
BACKGROUND OF THE INVENTION
[0002] In digital cameras and digital video cameras an optical image is converted into an electronic format by an image sensor, which is typically a photosensitive semiconductor element (Charge Coupled Device CCD or Complementary Metal oxide Semiconductor CMOS). This element is a plate known as a detector matrix which consists of small and regular photosensitive and colour-sensitive picture elements, i.e. pixels. The resolution of the matrix varies according to its physical size and fineness. An image sensor typically comprises hundreds of thousands of pixels, e.g. 640×480=307 200 pixels are used in VGA resolution (video graphics array). Utilization of advanced CMOS technology in the production of image sensors has enabled integration of digital and analogue electronics and the image sensor into the same semiconductor element. The size and weight of the camera module have been reduced, which has made it possible to integrate it into smaller and smaller electronic devices, such as mobile imaging phones.
[0003] The quality of an image produced by a camera module is usually proportioned to the display properties of the communication device, e.g. a mobile imaging phone. On a small screen the size of the picture elements that create an image, i.e. pixels, is smaller than in monitors used in offices, and thus at a certain resolution the sharpness of the image appears to be better to the human eye. The image quality on the screen of the communication device can be improved e.g. by providing the image with a greater contrast and more saturated colours. This makes the image seen on the screen of the communication device appear more natural to the viewer and improves its visibility.
[0004] When an image produced by a mobile imaging phone is transferred e.g. onto a computer screen which has better display properties than the mobile imaging phone, errors will appear in the image on the computer screen, such as discoloration or distortions. Due to this the image quality may have to be adjusted or improved. Furthermore, since the computing capacity of computers is nowadays considerably greater, a better image quality can be achieved e.g. using a computer program intended for image improvement. However, the user may find computer program of this kind difficult to use, and thus the user must have basic knowledge about the function and properties of image processing software to achieve the desired result in image improvement. Furthermore, the image improvement operation has to be performed separately on each image, which the user may find troublesome and time consuming.
SUMMARY OF THE INVENTION
[0005] The present invention provides a method and an apparatus for improving the image quality and especially, but not necessarily, for improving the quality of an image produced in a mobile imaging phone in a peripheral device, such as a computer or a server. Properties resulting from the errors of the camera module used for taking images are stored as image correcting information either in the memory of the camera module or in the memory of the electronic device into which the camera module is integrated or to which it is otherwise connected. Alternatively, the correcting information can be stored in the memory of a peripheral device, such as a computer or a server, which is capable of processing the image information produced by the camera module.
[0006] The image correcting information of the camera module is stored preferably during the manufacture of the camera module or the electronic device, such as a mobile imaging phone. The errors the camera module has caused in the image it has produced, such as optical distortions of the camera module lens, discoloration, and problems resulting from the quality of the camera module, such as noise and focus errors, can be reduced by comparing the image taken by the camera module and a test image. One or more image correcting parameters obtained as a result of the comparison are stored as image correcting information. The parameters are preferably stored in the memory of the server, but the image correcting information can also be stored in the memory of the camera module, mobile imaging phone or computer, for example. Storing of the image correcting information during the manufacturing process improves the usability of the device, for example. In that case image conversion does not require information on the properties of the device that has taken the image (camera module, mobile imaging phone) because this information has been stored in the device in advance. Thus image processing can be automated further and made faster. Transmission of the image in the original format e.g. from a mobile imaging phone reduces the amount of capacity required from the mobile imaging device because image processing is not carried out until in a peripheral device, such as a computer or a server.
[0007] A first aspect of the invention relates to a method of improving the quality of an image produced by a camera module in an electronic peripheral device, which is capable of processing said image, characterized in that the method comprises: storing image correcting information related to said camera module in the memory of the electronic peripheral device, receiving the image produced by said camera module and identifying information related to said image correcting information in said electronic peripheral device, and performing an image improvement operation on said image in said peripheral device using the image correcting information to which said received identifying information relates.
[0008] A second aspect of the invention provides an electronic peripheral device for improving the quality of an image produced by a camera module in said peripheral device, which is capable of processing said image, characterized in that said peripheral device comprises: a memory for storing image correcting information related to said camera module in the memory of said peripheral device, receiving means for receiving the image produced by said camera module and identifying information related to said camera module, and image improvement means for improving the quality of said image using in image improvement the image correcting information to which said received identifying information relates.
[0009] A third aspect of the invention provides a system for improving the quality of an image produced by a camera module in an electronic peripheral device, the system comprising at least one camera module which can produce an image and at least one electronic device which can transmit said image and identifying information related to the image to an electronic peripheral device, characterized in that the system further comprises: a memory for storing the image correcting information related to said camera module for said peripheral device, means for transmitting the image produced by said camera module and the identifying information related to said image correcting information to a peripheral device, and image improvement means for performing an image improvement operation to improve the quality of said image using the image correcting information to which said identifying information relates.
[0010] A fourth aspect of the invention provides a computer program product for improving the quality of an image produced by a camera module in an electronic peripheral device, which is capable of processing said image, characterized in that the computer program product comprises: computer program means for making said peripheral device store the image correcting information related to said camera module in the memory of said peripheral device, computer program means for making said peripheral receive the image produced by said camera module and identifying information related to said image correcting information, and computer program means for making said peripheral device perform image improvement to improve the quality of said image using the image correcting information to which said received identifying information relates.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the following, the invention will be described in greater detail with reference to the accompanying drawings, in which
[0012] [0012]FIG. 1 illustrates a system according to an embodiment of the invention,
[0013] [0013]FIG. 2 is a flow chart showing a method according to an embodiment of the invention,
[0014] [0014]FIG. 3 illustrates a camera module according to an embodiment of the invention,
[0015] [0015]FIG. 4 illustrates a communication device according to an embodiment of the invention, and
[0016] [0016]FIG. 5 illustrates a peripheral device according to an embodiment of the invention.
DETAILED DESCRIPTION
[0017] [0017]FIG. 1 illustrates a system according to an embodiment of the invention, the system comprising one or more mobile imaging phones 101 , 102 , which comprise a camera module 111 , 112 . The system further comprises a server 106 and a communication network 103 . An image produced by the mobile imaging phone 101 , 102 can be transmitted over the network 103 to a server 106 , which can store the image in a storage medium 108 , or print the image by a printer 107 . The system may also comprise e.g. a communication device 110 , which can communicate over the network 103 , and a computer 104 , which can receive the image produced by the mobile imaging device 101 , 102 e.g. over the network 103 and e.g. print the image by a printer 105 . A camera module (references 109 , 113 ) can be connected to the communication device 110 and the computer 104 for transmitting the image produced over the communication network 103 to a server 106 , for example.
[0018] The image correcting information of the camera module 109 , 113 is stored in the memory of the server 106 preferably during the manufacture of the camera module. The image correcting information of the camera module 113 can also be stored in the memory of the computer 104 , for example, and the image correcting information of the camera module 109 in the memory of the communication device 110 , for example. The image correcting information of the camera module 111 , 112 is stored in the memory 108 of the server 106 preferably during the manufacture of the camera module or the mobile imaging phone 101 , 102 . The image correcting information of the camera module 111 , 112 can also be stored in the memory of the mobile imaging phone 101 , 102 or the computer 104 .
[0019] The mobile imaging phone 102 can receive and transmit images produced by the camera module to another mobile imaging phone 101 , computer 104 , or server 106 e.g. over a Bluetooth connection or a communication network 103 , such as a mobile communication network or the Internet. The image produced by the camera module 112 of the mobile imaging phone 102 can be transmitted to the server 106 , for example. The image to be transmitted is also provided with an identifier by means of which the server 106 can identify the mobile imaging phone 112 that has transmitted the image and perform an image improvement operation on the image received using the image correcting information that corresponds to the identifying information and is stored in the memory 108 . The server 106 can store the improved image in the memory 108 , or if the user of the mobile imaging device 112 so wishes, transmit the image to a printing service for printing by a printer 107 . The printing service can be implemented e.g. as follows: the user of the mobile imaging phone 112 informs the server 106 of his/her name and address when transmitting an image, after which the printed image can be mailed to the user of the mobile imaging phone 112 , for example. The user of the mobile imaging phone 102 can, if he/she so wishes, retrieve the improved image from the memory 108 for the computer 104 later e.g. via the Internet network and print the image by the printer 105 .
[0020] The camera module 109 can be connected to the communication device 110 e.g. by a cable, a Bluetooth connection or an optical connection, such as an infrared connection. The image produced by the camera module 109 can be transmitted e.g. by the communication device 110 over the communication network 103 to the server 106 . The identifier of the camera module 109 is also transmitted at the same time so that the server 106 can perform an image improvement operation on the basis of the image correcting information related to the identifier of the camera module 109 .
[0021] The camera module 113 can be connected to the computer e.g. by a cable, a Bluetooth connection or an optical connection, such as an infrared connection. The image produced by the camera module 113 can be transmitted e.g. by the computer 104 over the communication network 103 to the server 106 . The identifier of the camera module 113 is also transmitted at the same time so that the server 106 can perform an image improvement operation on the basis of the image correcting information related to the identifier of the camera module 113 . Alternatively, the image correcting information corresponding to the identifier of the camera module 113 can be retrieved for the computer 104 , and thus the computer 104 can perform an image improvement operation on the image produced by the camera module 113 .
[0022] The computer 104 may be a portable computer or a workstation and it is capable of receiving images produced by the mobile imaging phone 102 either via a communication network 103 , e.g. the Internet, or on the Bluetooth connection or on a similar wireless connection, or over a cable connecting the devices. From the image information the computer 104 receives it can separate camera information which is associated with image information in the mobile imaging phone. The computer 104 can process the images to be displayed on the basis of the above-mentioned camera information. A printer 105 can also be connected to the computer 104 for printing the images. The computer can display the processed images by means of a monitor or the above-mentioned printer.
[0023] [0023]FIG. 2 shows a method according to an embodiment of the invention. In step 201 image correcting information of the camera module is produced, preferably during the manufacture of the camera module. If the camera module is integrated into an electronic device, such as a mobile imaging phone, the image correcting information can be produced during the manufacture of said mobile imaging phone. Alternatively, said image correcting information can be produced e.g. when the camera module or the mobile imaging phone is used for the first time.
[0024] The image correcting information is produced by comparing the image taken by the camera module with a test image, and image correcting parameters can be generated on the basis of this comparison according to the error type. The correcting information may include optical errors or image correcting parameters for correcting errors resulting from the quality of the camera module. Optical errors include faults the camera module lens causes in the image and colours. Errors resulting from the quality of the camera module include fixed pattern noise caused by the pixel structure, i.e. thermal noise, which increases as the amount of light decreases. Focus errors, i.e. crispening errors, occur particularly in connection with lenses with a fixed focus, e.g. the whole image is not focused. In that case the centre of the image, for example, can be sharp whereas the edges are fuzzy. Noise and sharpness are geometrical distortions that change radially from the centre of the optics, in which case the image correcting parameters are expressed as the centre of distortion and elliptic form for each colour component R, G and B (red, green and blue). The darkness of the image also changes radially towards the image edges. Darkness can be eliminated e.g. using a function of the 6 th order having the form 1+ar 2 +br 4 +cr 6 , where r is the distance from the centre and constants a, b and c are numbers that are defined on the basis of the test image.
[0025] In step 202 the correcting information is stored preferably in the memory of the peripheral device, such as a server, a mobile imaging phone or a computer, but it can also be stored in the memory of the camera module. The identifying information of the camera module is stored at the same time. Alternatively, the correcting information can be transferred from the memory of the camera module, mobile imaging phone or computer into the memory of the server e.g. by transmitting the correcting information and identifying information of the camera module, mobile imaging phone or computer to the server. The server stores the correcting information and identifying information and links these data with each other. The server can perform an image improvement operation on the image information it has received on the basis of the correcting information stored in advance and the identifier it has received.
[0026] In step 203 an image is produced in the camera module or mobile imaging phone. The image can be a still image or a video image which can be stored e.g. in the memory of said mobile imaging phone.
[0027] In step 204 the identifying information of the camera module or the mobile imaging phone and the image information are transmitted to a peripheral device, such as a server or a computer. The identifying information can alternatively be inserted into the above-mentioned image information in the mobile imaging phone, for example.
[0028] In step 205 the image information and correcting information are received by a peripheral device, such as a server or a computer, and the image improvement operation is performed on the basis of the correcting information.
[0029] [0029]FIG. 3 illustrates a camera module 300 according to an embodiment of the invention. The camera module comprises a memory or a similar dataslot 301 for the image correcting information, one or more optical lenses 302 , a photosensitive CMOS element or a CCD sensor element 303 , a control unit 304 for controlling the sensor element, a programmable analogue amplifier 305 (Programmable Gain Amplifier PGA). An analogue image signal is converted into a digital format by an AD converter 306 , after which it can be processed (reference 307 ) by different image processing operations e.g. by adjusting the colour balance and/or the white balance. Via the connection 308 the image signal is transmitted e.g. into the memory of the electronic device, such as the mobile imaging phone, or for display on the screen of the mobile imaging phone.
[0030] The correcting information is stored in the memory 301 of the camera module, preferably during its manufacture. The memory 301 also comprises the identifier of the camera module, by means of which the peripheral device can identify the camera module and perform an image improvement operation on the image information corresponding to the identifying information.
[0031] [0031]FIG. 4 illustrates a communication device 400 according to an embodiment of the invention, the communication device comprising a camera module 300 for producing an image onto a screen 406 or into a memory 404 , a transceiver 402 and an antenna 408 for transmitting and receiving data, e.g. image information, wirelessly, at least one application 405 for carrying out operations of the communication device, a processor 403 and a memory 404 for performing operations of the communication device 400 and the application 405 , a keyboard 407 for feeding commands into the communication device 400 . In addition, the communication device 400 comprises image correcting information stored in the memory or in a similar storage medium 409 . The memory 404 may further comprise the identifier of the communication device, by means of which the peripheral device can identify the image information transmitted by the communication device and associate the image information with the corresponding image correcting information.
[0032] The image correcting information is stored in the memory 409 preferably during the manufacture of the communication device or it can be stored in a storage medium, such as a CD, a DVD, a floppy disk or the like, in advance in some other manner. Alternatively, the correcting information can be produced afterwards, e.g. when the communication device is used for the first time. The camera module of the communication device 400 is used for producing image information which is compared with the test image. The comparison can be performed and the image correcting information produced e.g. by a computer or a similar device. The result of the comparison is used for producing image correcting information, which comprises at least one parameter that describes the interference in the image.
[0033] The image information produced by the communication device is transmitted together with the image correcting information to a peripheral device, such as a server or a computer, which performs an image improvement operation on said image information on the basis of said image correcting information. If the image correcting information is already stored in the peripheral device, the identifying information of the communication device can be optionally transmitted with the image information.
[0034] [0034]FIG. 5 illustrates a peripheral device 500 according to an embodiment of the invention. The peripheral device is preferably a server, but it may also be a computer. The peripheral device 500 comprises a storage medium 501 for storing image correcting information, a processor 502 and a memory 504 for controlling the operations of the peripheral device, a network interface 507 for receiving the image information and the correcting information and for transmitting corrected image information. The peripheral device 500 also includes a storage interface for storing the received correcting information and the image information in a mass memory, such as a hard disk, and a printing interface 509 for printing the corrected image information received by a printer. The peripheral device 500 may also comprise a keyboard 506 for feeding commands into the peripheral device, a monitor 503 for displaying the image information in visual form and at least one application 505 e.g. for performing an image improvement operation on the received image information on the basis of the image correcting information that corresponds to the image information and is already stored in the memory 501 of the peripheral device.
[0035] The peripheral device 500 receives the image correcting information of the camera module, which is preferably produced already during the manufacture of the camera module or an electronic device, such as a mobile imaging phone, into which the camera module is integrated. At the same time the peripheral device 500 also receives identifying information related to said camera module, electronic device or both. The identifying information can also be a serial number or another similar identifying code.
[0036] The identifying information and image correcting information received are stored in the memory 501 of the peripheral device and linked with each other. When the peripheral device receives an image produced by the camera module, it also receives identifying information, which is preferably related to the camera module, for example. The peripheral device compares the identifying information it has received with the identifying information stored in the memory 501 , and if the identifying information received is found in the memory 501 , the peripheral device performs an image improvement operation on the image it has received based on the image correcting information to which said identifying information received and stored in the memory 501 relates.
[0037] The implementation and embodiments of the invention were described by means of examples above. It is obvious to a person skilled in the art that the invention is not limited to the details of the embodiments described above and that the invention can be implemented otherwise without deviating from the characteristics of the invention. The embodiments shown should be regarded as illustrative only, i.e. the embodiments and applications of the invention are limited only by the appended claims. Consequently, different optional embodiments of the invention defined in the claims, including equivalent embodiments, fall within the scope of the invention. | A method and an apparatus for improving the image quality. The method comprises steps of producing image correcting information to decrease errors in the image to be produced by a camera module ( 109, 111, 112 ) by comparing the image taken by said camera module ( 109, 111, 112, 113 ) with a test image, storing the image correcting information produced and identifying information related to said image correcting information in the memory of an electronic peripheral device ( 104, 106 ), receiving the image produced by said camera module ( 109, 111, 112, 113 ) and a second piece of identifying information related to said image in the electronic peripheral device ( 104, 106 ), comparing said identifying information with said second piece of identifying information in said peripheral device, and performing an image improvement operation on said image in said peripheral device in response to the comparison carried out. | 7 |
TECHNICAL FIELD
The disclosed embodiments relate to the construction and nailing of shear walls.
BACKGROUND INFORMATION
A shear wall is a wall that typically includes braced sheathing panels (also known as shear panels) nailed to framing members and an associated set of hold-downs. The shear wall counters the effects of lateral loads. When building a shear wall, structural plywood or particle-board sheathing panels are typically applied to cover wood stud framing. A nail gun is then typically used to nail the panels to the underlying framing in a specified nailing pattern. The particular pattern is important and is specified by a structural engineer.
One of several methods may be used to construct a shear wall in the field. In one method, the appropriate lengthwise (vertical) spacings between nails are measured and the nail locations are manually marked with a pencil. The marks on the sheathing are then used to place nails during the nailing operation. The manual pencil marking is time consuming. Moreover, the nails are to be properly spaced in not just one dimension (the lengthwise or vertical dimension), but rather are also to be properly spaced offset from the edge of the sheathing (the horizontal dimension). Typically the nails are specified to be spaced a certain distance from the edges of the sheathing panels or from edges of the underlying framing members, depending on the nailing pattern and nailing density specified. Sometimes a chalk line is used to accomplish this horizontal marking. Often, however, the extra trouble of using a chalk line is dispensed with and the horizontal spacing of the nails is just “eyeballed”. Due to this eyeballing, the horizontal spacing of the nails may be irregular and imprecise.
In a second method, no marking whatsoever is performed. The individual with the nail gun simply “eyeballs” both the vertical and horizontal placement of each nail at the time of nailing and then drives the nail using the nail gun. The resulting spacing of nails is therefore not always precise. The person doing the nailing may intend to place nails with a specified three inch vertical spacing, but when the spacing between the actual nails as placed is measured, the spacing may be four inches in places.
SUMMARY INFORMATION
A non-structural shear wall nailing template bears a pattern of shear wall nailing pattern markings. The template may, for example, be made of paper, mylar, or other printable substrate. In one example, the pattern is a “field” nailing pattern and the template also bears a second pattern. The second pattern is an “edge” nailing pattern. The template bears lettering (numerals and/or lettering and/or a symbol) that indicates the type of nailing pattern that the nailing pattern markings conform to. If, for example, the nailing pattern markings are for the nailing of a “type 3 shear wall”, then the lettering on the template might be a “3”. If, for example, the nailing pattern markings are for the nailing of a “type 4 shear wall”, then the lettering on the template might a “4”.
In one example, a very long length (for example, one hundred feet) of the template material is rolled into a roll. Such rolls are sold at the retail level. An individual who is constructing a shear wall in the field separates a length of the template material from such a roll to form the template. The length may, for example, be torn from the roll by hand without the use of any cutting tool. Alternatively, the length can be cut from the roll using a scissors or box cutter or knife or serrated edge or another suitable cutting implement. Alternatively, the length can be extended from a roll and then cut off from the roll using an ordinary handheld packing tape dispenser.
The template is then fixed to one or more sheathing panels that are to be nailed to framing members in accordance with a specified nailing pattern. The template may include an adhesive layer that is usable to fix the template in place to the sheathing panel(s). The template may be tacked in place using a few nails or staples. The template is fixed to the sheathing panel(s) such that the template is aligned in a pre-defined way with respect to a framing member behind the sheathing panel(s).
A different nail is then driven through the template at each different marking location of the pattern on the template. Each such nail is driven through the template, then through the sheathing panel, and then into the framing member. By driving a nail at the location of each marking on the template, the shear wall is constructed with proper nailing spacing. The manual measuring and pencil marking described above in the background information section can be avoided. The eyeballing described above in the background information section can be avoided.
The nailing template is made of a lightweight inexpensive non-structural material and need not be removed once construction of the shear wall has been completed. The template may, for example, be made of inexpensive and lightweight paper or mylar or another suitable inexpensive sheeting material that will not interfere with the further construction of the building if the template is not removed.
This summary does not purport to define the invention. The invention is defined by the claims.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a diagram of a shear wall nailing template in accordance with one novel aspect.
FIG. 2 is a diagram that illustrates one example of how the shear wall nailing template of FIG. 1 can be used in the making of a shear wall.
DETAILED DESCRIPTION
FIG. 1 shows a lightweight non-structural shear wall nailing template 1 in accordance with one novel aspect. Template 1 is a strip at least five feet in length. Template 1 preferably has a uniform width of between one inch and eight inches wide. The template material is therefore referred to here as “tape”.
In the specific example illustrated, template 1 is a portion of a roll of a one hundred foot length of tape, where the tape is two and one half inches wide. The one hundred foot roll of tape weighs less than one hundred sixty ounces (five pounds). The tape is made of an inexpensive, flexible, non-metallic, lightweight non-structural material (for example, paper or mylar or polyester) through which standard nails used in making shear walls can be easily driven using hand tools. The tape material is such that the tape can be cut easily with ordinary box cutters or scissors or a knife or a serrated edge such as that found on a typical packaging tape dispenser. In one embodiment, lengths of the non-structural template tape material can be torn from the roll by hand without the use of box cutters or scissors or any other tool. Template 1 may, for example, include an adhesive layer on one side such that the template strip can adhere to ordinary plywood or particle-board sheathing material. Template 1 may involve two layers where one of the layers is a disposable backing layer. When the backing layer is removed, an adhesive side of the other layer is exposed.
There are two sets of nailing pattern markings on template 1 . The markings are printed on the template tape material. The markings of the first set of nailing pattern markings are denoted 2 - 9 . This first set of markings is to be used when template 1 is used to determine nail placement at edges of panels. Instructional lettering 10 corresponds to the first set of nailing pattern markings. The instructional lettering 10 states “PANEL EDGE: FILL ALL RED SQUARES”. The markings of the first set are colored red so that the markings of the first set can be visually distinguished from markings of the second set.
Markings of the second set of nailing pattern markings are denoted 11 and 12 . Instructional lettering 13 corresponds to the second set of nailing pattern markings. Instructional lettering 13 states “FIELD NAIL: FILL ALL BLACK SQUARES”. The markings of the second set are colored black so that the markings of the second set can be visually distinguished from markings of the first set.
In addition to the first and second sets of nailing pattern markings, template 1 bears a heavy dashed centerline marking 13 as illustrated in FIG. 1 . Centerline marking 13 is usable to place and align template 1 properly with respect to a vertical joint between abutting plywood panels, or with respect to a vertical line such as a chalk line or a line of nails.
In addition, template 1 includes an indication of a particular nailing pattern to which to the markings on the template conform. One nailing pattern is commonly referred to as a “3” and the associated type of shear wall is commonly referred to as a “3 shear wall”. The numeral “3” lettering (the term “lettering” here is used to denote numerals and/or letters and/or symbols) in the triangular symbols 14 and 15 indicate that the nailing pattern marked on template 1 is the nailing pattern used to make a “3 shear wall”. The “3” is referred to as the nailing pattern type. In the “3” nailing pattern type, edge nail markings disposed along the same sheathing panel are separated by three inches and alternate between two vertical lines. Marks 2 and 3 are, for example, separated by a distance of three inches. Marks 2 and 4 are, for example, disposed along the same vertical line and are separated by six inches (three inches twice). Similarly, marks 3 and 5 are disposed along the same vertical line and are separated by six inches. Marks 7 and 9 are disposed along the same vertical line and are separated by six inches. Marks 6 and 8 are disposed along the same vertical line and are separated by six inches. The staggering of the markings in both the vertical and horizontal dimensions is as specified by the “3 shear wall” specification.
FIG. 2 is a diagram that illustrates a method of using template 1 of FIG. 1 . A frame includes horizontal framing members 20 - 22 and vertical framing members 23 - 27 . Vertical framing members 23 , 24 , 26 and 27 are, in this specific example, 2×4 wood studs that are pictured on edge in the diagram. Framing members 23 , 24 , 26 and 27 are approximately one and half inches wide as viewed in FIG. 2 . Framing member 25 is a 3×4 wood stud. The side of framing member 25 that is seen in FIG. 2 is the side of member 25 that is approximately two and one half inches wide.
Two standard four foot by eight foot plywood or particle-board sheathing panels 28 and 29 (also referred to as “siding panels”) are oriented edge-to-edge such that the large face-sides of the panels are disposed in the plane of the page in the illustration of FIG. 2 . Line 30 illustrates the vertical boundary between the two abutting edges of panels 28 and 29 . These two sheathing panels are to be nailed to the framing members to make the shear wall. In a first step, the two panels are tacked in place with a few holding nails. Rather than abutting one another, the two sheathing panels may actually be separated by a small specified gap.
Next, five template strips 31 , 32 , 1 , 33 and 34 of the novel template strip tape material are attached to the front side of the sheathing panels 28 and 29 as illustrated. Each of the templates is an eight foot piece taken from the same roll of the template strip material. If templates 31 , 32 , 1 , 33 and 34 are self-adhesive and have an adhesive on one side, then the adhesive holds the templates to the sheathing panels. Alternatively, templates are tacked in place with a few holding nails or staples.
Next, templates 31 , 32 , 1 , 33 and 34 are used in the nailing process. Templates 31 32 , 33 and 34 are disposed over framing members 23 , 24 , 26 and 27 as illustrated. These templates are not aligned along edges of the panels. The nails in these portions of the shear wall are therefore said to be in the “field” of the panels. Nails are therefore placed using the “field” nailing pattern of nail markings (see FIG. 1 ). Which markings are the field markings and which markings are the edge markings are designated by the instructional lettering on the template strips. A nail is driven through each of the field nailing markings in templates 31 , 32 , 33 and 34 such that the nail extends through the template, then through the sheathing, and then into the framing member behind the sheathing. The markings used are illustrated in FIG. 2 as solid black markings.
Template 1 , however, is disposed over the rightmost edge of panel 28 and over the leftmost edge of panel 29 . The centerline 13 of template 1 is aligned over the boundary 30 between the two panels 28 and 29 as illustrated in FIG. 2 . This template 1 is not disposed in the “field” of the panels, but rather is disposed along edges of the panels. The pattern of nails to be used in the nailing process is therefore said to be an “edge pattern”. Nails are therefore placed using the “panel edge” pattern of markings (see FIG. 1 ). A nail is driven through each of the panel edge markings in template 1 at a specified distance from an edge of the sheathing. The nail passes through the template 1 , then through the sheathing, and then into the framing member 25 behind the sheathing. The markings used are illustrated in FIG. 2 as solid black markings.
FIG. 2 shows the structure of the framing in the cutaway portion 35 at the top of the diagram. FIG. 2 also shows a cutaway portion 36 of how the structure would look with the sheathing applied but before the templates 31 , 32 , 1 , 33 and 34 are applied. The vertical dashed lines in cutaway portion 36 indicate where the framing members are located behind the sheathing. Cutaway portion 37 of FIG. 2 shows the structure after the templates 31 , 32 , 1 , 33 and 34 have been applied to the surface of panels 28 and 29 .
In one example, a selection of rolls of template strip material is made available to a framer. In this selection, there is a roll that bears nail markings for each nailing pattern to be used in the framing of a building. The framer uses a set of constructions plans, identifies from the construction plans the pattern of nailing specified for a particular shear wall, selects the associated roll whose marks 14 and 15 identify that nailing pattern, and then fixes strips of the template tape as illustrated in FIG. 2 . The framer works around a building being framed in this manner, attaching the proper types of templates. The templates are then used as guides in the subsequent nailing process so that the nailing schedule as specified on the construction plans is followed. The non-structural template tape material remains in place after nailing so that a subsequent inspection of the nailing is made easier. The non-structural template tape material is made from an inexpensive material so that using the template material does not add an undesirably large amount of material cost to the building. The non-structural template tape material is made of a material that can be readily pierced by nails and staples so that the presence of the in-situ template does not interfere with subsequent attachment of materials to the nailed surface of the finished shear wall.
Although certain specific exemplary embodiments are described above in order to illustrate the invention, the invention is not limited to the specific embodiments. In one embodiment, the nailing markings are actually small holes in the template tape material. Although an example of a shear wall nailing template is described above that is less than eight inches wide, a shear wall template in some novel embodiments is wider than eight inches and includes nailing markings usable for nailing a sheathing panel to two different parallel extending wall studs that are disposed at a distance (for example, twelve or sixteen inches) from one another. The template may, for example, be a sheet that covers the entire surface area of a four foot by eight foot sheathing panel. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the following claims. | A non-structural shear wall nailing template bears a pattern of shear wall nailing pattern markings. The template is made of an inexpensive sheeting material that will not interfere with the further construction of the building if the template remains in-situ after construction of the shear wall. In one example, the template is a strip. The strip bears lettering that indicates the type of nailing pattern to which the nailing pattern markings conform. After fixing the template to one or more sheathing panels such that the template is aligned in a predefined way with respect to framing members behind the panel(s), nails are driven at the locations of the markings on the template. By driving a nail at the location of each template marking, the shear wall is constructed with proper nail spacing. A set of templates is provided to facilitate nailing in different shear wall nailing patterns. | 4 |
This is a Continuation-In-Part of International Patent Application No. PCT/IL2005/000087, filed Jan. 25, 2005, and published as WO 2005/070583, which in turn takes priority from Provisional Patent Application No. 60/538,500 filed Jan. 26, 2004.
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to an apparatus and method for forming of a vehicle's driveshaft having an elongated shaft and two coupling end parts. This is achieved, in accordance with the invention, by a pulsed magnetic force (PMF) process.
A vehicle's driveshaft, having the general structure as outlined above, is commonly manufactured by welding ends of a cylindrical shaft to coupling end parts. Conventional welding is a time consuming and relatively expensive process.
Furthermore, the workpieces are typically heated in this process and therefore at times cooling installations need to be included.
A known way of rapid “cold” joining or welding of workpieces to one another is by the use of a PMF process. By this technology, a very short and intense electric pulse is discharged through a coil and this discharge induces eddy currents in a workpiece which yield magnetic repulsion between the electric coil and the workpiece. This repulsion then deforms the workpiece proximal to the forming coil causing its surface to rapidly move and impinge on another workpiece whereby it either pressure joins, and with higher energy surface welds to the other workpiece.
A particular application of this process is in joining or surface welding of a tubular workpiece onto a cylindrical one contained therein by inducing inward radial deformation of the tubular workpiece. PMF processes and some specific applications thereof are disclosed in the following U.S. Pat. No.: 3,654,787 (Brower), U.S. Pat. No. 3,961,639 (Leftheris), U.S. Pat. No. 4,170,887 (Baranov), U.S. Pat. No. 4,531,393 (Weir), U.S. Pat. No. 4,807,351 (Berg et al.), U.S. Pat. No. 5,353,617 (Cherian et al.), U.S. Pat. No. 5,442,846 (Snaper) and U.S. Pat. No. 5,824,998 (Livshitz et al.).
A specific application of the PMF process for the purpose of joining components for a vehicle's driveshaft is described in U.S. Pat. No. 5,981,921.
There are some specific problems in the realization of the PMF process for forming a driveshaft in that the end pieces radially protrude beyond the circumference of the shaft. In order to utilize the PMF process, the forming coil should be brought into close proximity to the deformed workpiece and in this case this means that the forming coil needs to be closely fitted around the shaft. After joining or surface welding of the shaft and the coupling end part, it is not possible, with the prior art methods, to release the coil turnover and the driveshaft. This is the reason, that the PMF process has not yet found a true application in practice in the field of forming of driveshafts.
SUMMARY OF THE INVENTION
In accordance with the invention an apparatus and method for forming a driveshaft is provided. In accordance with the invention, the above noted problems are overcome by providing an apparatus and utilizing a method in which the forming coil is assembled around the shaft from two or more coil sections which are firmly attached to one another. This forming coil is associated with a current generating unit such that through current discharge from said unit a PMF is produced to cause pressure joining or surface welding of the two driveshaft components.
In the following, the term “joining” will be used to jointly denote both joining of two workpieces, which means bringing their juxtaposed surfaces into very close proximity in a manner so that they pressure impact with one another, as well as surface welding which means in effect a molecular interaction between their juxtaposed surfaces of the two workpieces. In fact, whether joining or welding is achieved in the PMF process depends, to a large extent, on the amount of PMF energy and of the exact working parameters. The artisan will be able to define whether joining or surface welding is required and also to define the exact parameters needed to achieve either joining or welding. For parameters to achieve welding, reference is made to U.S. Pat. No. 5,824,998, which is incorporated herein by reference. As stated, the term “joining” should be construed as referring to either or both of joining and welding.
In accordance with the invention there is provided a novel apparatus and method for forming a driveshaft of the kind having a shaft and two coupling end parts of radial dimensions larger than those of the shaft.
The apparatus comprises one or two forming assemblies for forming one end or two ends of a driveshaft, respectively; the one or two forming assembles comprising each a holder and a forming unit. The holder is a adapted to receive and hold a driveshaft end part pre-assembly which after joining will form the end part of the driveshaft. The pre-assembly consists of two components, of which one is an end section of an elongated shaft that defines an axis, and the other is a coupling end part member, either the shaft end section or a portion of the end part member having a generally cylindrical shape with an axial cylindrical cavity that accommodates an axial cylindrical portion of the other snugly fitted therewith, the end section and said portion defining together a cylindrical joining section of the two components. The forming unit comprises a forming coil device that defines a forming space which can accommodate said joining section and comprises a current generating unit that is associated with the forming coil device, for generating a current pulse within the forming coil unit thereby to yield a PMF sufficiently strong to yield joining the two parts of the joining section. The forming coil device is assembled from two or more coiled sections which are firmly attached to one another at attachment faces thereof, which can be disassembled to permit release of the so formed driveshaft end part.
The method for forming a driveshaft in accordance with the invention comprises: (a) providing a shaft, the shaft defining an axis, and a coupling end part member; either the shaft end section or a portion of the end part member having a generally cylindrical shape with an axial cylindrical cavity and the other having an axial cylindrical portion that can fit within said cavity, and fitting said cylindrical portion into said cavity to define together a joining section with an external cylindrical shape cavity can accommodate of the other snuggly fitted therewithin and defining together a cylindrical joining section of the two components; (b) fitting a forming coil device around said joining section, the forming coil device being assembled from two or more coil sections firmly attached to one another at attachment faces thereof and being associated with a current generating unit; (c) generating an intense current pulse through said forming coil device to generate a pulsed magnetic force (PMF) sufficient for joining the two parts of the joining section; and (d) disassembling the forming coil device to free the so formed end section of the driveshaft. Steps (a) and (d) may either be performed simultaneously for the two ends of the shaft to simultaneously join two coupling end part members one to each end of the shaft Alternatively, these steps may be performed in sequence by first carrying out steps (a) to (d) for joining one coupling end part member to one end of the shaft and then repeating these steps for joining another coupling end part member to the other end of the shaft.
An apparatus for simultaneous forming of the two end parts of a driveshaft will comprise two forming assemblies. Where the apparatus comprises a single forming assembly, first one end will be formed, the shaft will then be reversed and the other end will then be formed.
In accordance with one embodiment of the invention, the forming coil is connected directly to a current discharge circuitry. In accordance with this embodiment, the coil device is comprised of two or more, typically three or more coil sections of which two are end section connected each to one pole of the current discharge circuitry. In the case of three coil sections, for example, two are such end sections and one is an interconnecting section. In accordance with one embodiment, a coil of this kind is formed from a dielectric, non-electrically conducting material with an inner layer made of an electrical material. The dielectric material there serves as a structured element. An example of such a material is epoxy glass. The conducting layer may be made of copper as well as any other suitable method substance. Typically, the conducting layer extends also to the attachment faces and serves as the electrical link between the different sections.
The different sections may be held together by a reinforcing structure, may be connected to one another by the use of screws and bolts and in general by any other suitable means.
In accordance with another embodiment, the forming coil device is an independent coil device being an inductive association with a primary coil which is in turn connected to a current discharge circuitry, whereby a current pulse discharged through the primary coil induces the generation of a forming current pulse within the forming coil. In accordance with the one preferred embodiment, a forming unit comprises a primary coil connected to a current discharge circuitry for generating an intense current pulse, and two or more inserts, each of which constitutes a section of a forming coil device accommodated within an opening defined by the primary coil, the opening being of a diameter sufficient to permit the coupling end part to pass therethrough, and defining in turn a forming space to accommodate said joining section; the inserts being made of or having at least outer, inner and radial faces being made of an electrically conducting layer and being attached to one another at attachment faces with an electrically insulating layer between them. The inserts, in accordance with this embodiment, are typically a trapezoidal cross-section with the broad base facing outwards and the narrow base facing inwards juxtaposing the joining section.
The method in accordance with the above preferred embodiment, comprises: fitting a forming coil device adjacent said joining section, the forming coil device comprises a primary coil connected to a current discharge circuitry for generating an intense current pulse, and two or more inserts, each of which constitutes a section of a forming coil device accommodated within an opening defined by the primary coil, the opening being of a diameter sufficient to permit the coupling end part to pass therethrough, and defining in turn a forming space to accommodate said joining section; the inserts being made of or having their external layer made of an electrically conducting layer and being attached to one another at attachment faces with an electrically insulating layer between them; generating an intense current pulse through said primary coil to induce a forming current in the inner face of the forming coil device to generate a pulsed magnetic force (PMF) sufficient for joining the two parts of the joining section; and disassembling said inserts and removing the primary coil by axially moving either the primary coil or the formed driveshaft end.
In accordance with one preferred embodiment, it was found that superior joining is achieved by the use of an auxiliary device which is temporarily fitted together with the end part member to yield together a body having axial symmetry.
After formation of the joins between the shaft and the end part member, the auxiliary device is removed.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out in practice, a preferred embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
FIG. 1A is a schematic longitudinal section through a prior art vehicle driveshaft.
FIG. 1B is a longitudinal section of the vehicle driveshaft of the invention.
FIG. 1C shows the end section of the shaft overlapping the end recess of the end part prior to constriction to form the driveshaft of FIG. 1B .
FIG. 2A is a partial longitudinal cross-section of an apparatus of the invention with a driveshaft to be formed therewith.
FIG. 2B is a view from the direction of arrow II in FIG. 2A .
FIG. 3A is a schematic longitudinal cross-section of an apparatus in accordance with another embodiment of the invention with the driveshaft to be formed therewith.
FIG. 3B is a cross-section through lines III-III in FIG. 3A .
FIG. 4 shows a typical fork-shaped driveshaft end piece.
FIG. 5 is a partial view of an apparatus of the invention adapted for joining an end piece of FIG. 4 .
FIG. 6 shows a coil device structure in accordance with another embodiment of the invention.
FIG. 7 is a view similar to FIG. 1C illustrating use of an intermediate driver element according to a further feature of the present invention.
FIG. 8 is a view similar to FIG. 3A illustrating use of an intermediate driver element according to a further feature of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first being made to FIG. 1A , which shows a prior art driveshaft.
The driveshaft 1 consists of a tubular shaft 2 and two coupling end parts 3 and 4 , one at each end of shaft 2 . The two ends 2 A and 2 B of shaft 2 are sealed each in a respective recess 3 A and 3 B of end parts 3 and 4 , respectively, and welded to it by conventional welds 3 B and 4 B, respectively.
In distinction from prior art driveshafts, driveshaft 6 made in accordance with the invention, shown in FIG. 1B (where like elements were given the same reference numeral with a prime indication), is formed by welding the shaft 2 ′ to the coupling end parts 3 ′ and 4 ′ by the use of a PMF process. The ends 2 A′ and 2 B′ are constricted and sealed in recesses 3 A′ and 4 A′, the constriction being achieved through a PMF process such as that will be described below. Through the PMF process ends 2 A′ and 2 B′ also become welded to respective recesses 3 A′ and 4 A′.
As will also be appreciated, while the shaft shown herein is a tube, in other embodiments of the invention it may be a solid, elongate cylindrical mass.
FIG. 1C shows the end 2 A′ of shaft 2 ′ overlapping the recess 3 A′ of end part 3 ′ prior to PMF application. There is a gap between these two workpieces such that ratio of h as the length l of the overlapping portion typically meet the formula h/l=0.1−0.5.
FIGS. 2A and 2B show a forming coil device generally designated 8 accommodating a driveshaft pre-assembly consisting of an end part member 10 having flange portion 12 and an end section 11 of tubular shaft. The coil device 8 is a single wind coil formed by three coil sections 14 A, 14 B and 14 C each of which is constituted from respective dielectric body 15 A, 15 B and 15 C and with respective conducting layers 16 A, 16 B and 16 C.
Layers 16 A, 16 B and 16 C may typically be made of copper or any other high conductive material. The dielectric body 15 A, 15 B and 15 C may, for example, be made of epoxy glass or any other suitable dielectric material which has the property of being able to resist strong and abrupt forces (the PMF process causes very strong radial forces on the forming coil). Each of the layers 16 A, 16 B and 16 C extend over attachment faces 17 by which the different coil sections are attached to one another. This ensures electrical contact between the conducting layers in the different coil sections whereby all conducting layers constitute together a single wind coil. At their other end conducting layers 16 A, 16 B terminate in two respective protruding conductor sections 18 A and 18 B linked to a discharge circuit 19 consisting of a capacitor battery 20 and a switch 21 . Bodies 15 A, 15 B and 15 C may comprise respective cooling channels 21 A, 21 B and 21 C having inlets and outlets, that is inlet 22 and outlet 23 , respectively, and transfer of a cooling fluid (a gas or liquid) therethrough. The different coil sections may be held together by a variety of means such as for example an external holding structure or any other suitable fixing arrangement as may be known per se.
As can be readily appreciated, after joining of a tubular section 10 to the end section 11 of the shaft, the coil device is disassembled to free the formed driveshaft end section.
Reference is now being made to FIGS. 3A and 3B showing an apparatus, generally designated 30 , with a driveshaft pre-assembly 31 consisting of a shaft 32 and two end part members 33 , one at each end of shaft 32 . In the apparatus of this embodiment, the two end parts of the driveshaft are formed simultaneously.
Pre-assembly 31 is mounted between two holders 35 having a stepped protrusion 36 with an inner section 37 fitted within the lumen of shaft 32 , an intermediate section 38 and an outer flange 39 . In this way, the pre-assembly is firmly held in a firm pre-assembly arrangement.
The apparatus comprises two forming assemblies 40 and 41 each including a multi-wind primary coil 44 and 45 , respectively, which are interconnected by a lead 46 and linked at their respective ends 47 to a current discharge circuitry 48 including a capacitor battery 49 and a switch 50 . The primary coils 44 and 45 are coaxial with shaft 32 . Two crescent shaped field shapers 42 and 43 are fitted within the space defined by the primary coils 44 , 45 and constitute together a forming coil device 51 also coaxially with the shaft 32 . The two field shapers 42 and 43 define together a forming space 52 fitted around the portions of the pre-assembly which are to be joined to one another. Holes 55 may be formed in the field shaper sections 42 , 43 for both cooling and current concentration. The ends 56 and 57 are insulated to avoid electric contact between the two inserts.
In operation, a very short and intense electric pulse is actuated by the discharge circuitry 48 which then passes through primary coils 44 , 45 inducing an oppositely directed current in field shapers 42 and 43 and this current circulating in each of the field shapers causes a magnetic repulsion between the field shapers and the pre-assembly portions contained within the forming space thereby causing the two to pressure join, and with higher energies to surface weld, to one another. In this embodiment, both joins are formed simultaneously. It is appreciated that it is possible, in accordance with other embodiments, to separate the primary coils 44 and 45 and provide each with an independent current discharge circuitry having each an independent ignition arrangement. Alternatively, coils 44 and 45 may also be in a parallel electrical conductor (i.e. both to the same discharge circuitry).
In the specific embodiments of the apparatus shown in FIGS. 3A and 3B , field shapers 43 are fixed onto a pole 60 while field shapers 42 are linked to an opening mechanism 61 . At the end of the operation, primary coils 44 and 45 can be moved axially to permit removal of field shapers 42 . After such removal, the so formed driveshaft may be removed.
When the coupling end part member has a significant axial asymmetry close to the portion which is to be joined or welded, for example, a fork-shaped end part as is typically the case with driveshafts end parts, the electromagnetic field generated by the PMF process, may become irregular near the asymmetrical end piece portion, which may cause non-uniformity of the joins. In order to overcome this problem, an auxiliary device may be used, aimed at temporal restoring the axial symmetry of the coupling end part member. The insert is preferably produced from a material similar in electromagnetic properties to the coupling end part member.
FIG. 4 shows a typical driveshaft coupling end part member which consists of a cylindrical joining portion 71 and a fork connector portion 72 .
In FIG. 5 the axial asymmetry of fork 70 is compensated for by the use of an auxiliary device 75 , which in this case constitutes an integral part of the holder 31 .
When the pre-assembly is fixed on holder 31 , the fork 72 combines with the auxiliary device 75 to induce a combined body with an axial symmetry. When the driveshaft is unloaded from the apparatus, the auxiliary device stays connected to a holder 31 .
A coil assembly useful in an apparatus in accordance with another embodiment of the invention is shown in FIG. 6 . Two forming coil members 81 and 82 , form part of structures 83 and 84 , respectively, shown herein in an exploded view but which in use are placed proximal to one another with a distance between them of about 2 mm or less.
Structure 83 is a closed loop conductor constituted by a planar conductive strip, but for coil member portion 81 . Structure 84 is constituted from a similar planar conductive strip, ending, however, at open ends 85 and 86 connected to a discharge circuitry (not shown).
In use, when current is discharged through conductor structure 84 , current progresses along arrows 90 and this causes a counter current in the direction of arrows 91 in conductor structure 83 . This yields an overall circular current around forming space 95 defined by two coiled sections 81 and 82 . Placed in this forming space 95 , is the portion to be joined of the driveshaft pre-assembly with the coupling end part facing towards the interior of conductor structures 83 and 84 .
Turning finally to FIGS. 7 and 8 , since the technique of PMF forming is based upon induced electric eddy currents within the workpiece, the energy efficiency of the technique is much lower for metals having relatively poor electrical conductivity (such as Steel, Titanium and Nickel alloys) than for those with high conductivity. In order to improve the efficiency of the technique, certain implementations of the present invention employ a driver element, formed from metal with a higher electrical conductivity than the workpieces, deployed around at least part of the joining region. The presence of this driver element reduces the energy required for a given welding effect. This feature will now be illustrated with reference to FIGS. 7 and 8 .
FIGS. 7 and 8 are generally similar to FIGS. 1C and 3A , respectively, and employ the same reference numerals for equivalent elements. As seen in FIG. 7 , the workpiece is here modified by addition of a driver element 99 deployed in close overlapping relation with at least part of the region of overlap of end 2 A′ and recess 3 A′. Driver element 99 is formed from a metallic material with electrical conductivity higher than that of the recessed element, and most preferably, from a high-conductivity metallic alloy such as an Aluminum or Copper alloy. Driver element 99 preferably extends around the entire circumference of the cylindrical joining region, and most preferably also overlaps substantially the entire length l of the joining region. The element may be implemented as a solid metal collar, or may be flexible foil wrapped around the joining region. The total thickness of driver element 99 is preferably in the range from 0.3 mm to 2 mm, and its width (i.e., the dimension parallel to the axis of the shaft) is preferably in the range from 1 mm to 30 mm. After welding, driver element 99 may remain as part of the joined structure, or may be removed (e.g., peeled off) by any suitable mechanical or other technique.
FIG. 8 shows a forming device similar to that of FIG. 3A , with equivalent elements labeled similarly. In this case, field shapers 42 and 43 have been modified to allow space of driver element 99 . In all other respects, the structure and operation of the device of FIG. 8 is essentially the same as that of FIG. 3A described above.
It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims. | An apparatus ( 30 ) and method for forming of a vehicle's driveshaft ( 32 ) is provided which makes use of a PMF process. The coil device used in the PMF apparatus is assembled around the shaft from two or more coil sections ( 40, 41, 43; 42, 44, 45 ) firmly attached to one another, and which may be disassembled from one another to allow to remove the formed driveshaft ( 32 ). | 1 |
BACKGROUND
[0001] 1. Field
[0002] The present disclosed embodiments relate to an automated messaging system and, more particularly to an artificial intelligence assisted live agent chat system.
[0003] 2. Background
[0004] In order to provide proper customer support and service, companies typically expend a large amount of funds to establish and support telephone call centers. To minimize customers being placed on hold when they call companies for support or service, call centers must be staffed with a sufficient number of customer support representatives (also referred to as agents), because each of them can normally only handle a single telephone call at a time.
[0005] Technical solutions such as online chat and instant messaging systems provide a less costly alternative to telephone call centers because a customer support representative may be able to handle multiple conversations (“chats” or “chat sessions”). However, the staffing of agents for backend operations centers required to implement live online chat applications can still be very expensive. Consequently, even though an average agent is now able to handle a few chat sessions simultaneously this solution may still remain fairly expensive.
[0006] Also, many times a large percentage of the customer queries are similar, if not identical to each other. Using a live agent to repeatedly read and respond to the same set of frequently asked questions is an inefficient use of an agent's time and the center's capacity.
SUMMARY
[0007] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overviews of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of an, or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
[0008] According to an aspect a method is disclosed for assisting a live agent in interacting with customer inquiries through a network chat messaging system for a website that includes detecting a customer interaction with the website, determining whether an automated response system is enabled to respond to the customer interaction, the automated response system being capable of interacting with the customer through the network chat messaging system using an artificial intelligence (AI) system; and, notifying the live agent regarding the customer interaction upon determining the automated response system is disabled.
[0009] According to another aspect, a computer interface is disclosed for a live agent to interact with a plurality of customers through a network chat messaging system having an artificial intelligence (AI) system for interacting with each customer in the plurality of customers that includes a list of live chat sessions being monitored by the live agent, the list comprising a chat session status indicator; and a chat session interface for monitoring the AI system and interacting with at least one customer in the plurality of customers. The chat session interface also includes a live agent message input field: a live agent message display; and an AI system proposed response display for displaying proposed responses generated by the AI system.
[0010] According to another aspect, a computer program product for assisting a live agent in interacting with customer inquiries through a network chat messaging system for a website is disclosed. The computer program product includes a computer readable medium having codes executable to detect a customer interaction with the website; determine whether an automated response system is enabled to respond to the customer interaction, the automated response system being capable of interacting with the customer through the network chat messaging system using an artificial intelligence (AI) system; and, notify the live agent regarding the customer interaction upon determining the automated response system is disabled.
[0011] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more aspects. These aspects are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed aid the described aspects are intended to include all such aspects and their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a system diagram illustrating a network of computer systems, configured in accordance with one approach of an artificial intelligence (AI) assisted live agent chat system.
[0013] FIG. 2 is a flow diagram illustrating an exemplary operation of the AI-assisted live agent chat system that can support interactions between a live agent and one or more customers.
[0014] FIG. 3 is a sample screen capture of a graphics user interface (GUI) implemented by a web page of a website's customer service section showing a chat window usable for a customer to interact with a chat system such as the AI-assisted live agent chat system of FIG. 1 .
[0015] FIG. 4 is a sample screen capture of a GUI of an agent interface illustrating the capabilities provided to a live agent for monitoring multiple chat sessions, enabling or disabling the AI system, repooling one or more chat sessions, pushing scripted lines generated by the AI-assisted live agent chat system ending chat sessions, and transferring chat sessions to a different live agent.
[0016] FIG. 5 is a sample screen capture of the agent interface of FIG. 4 illustrating an alert generated by the AI-assisted live agent chat system to the live agent that intervention by the live agent is needed.
[0017] FIG. 6 is a block diagram of a computer system usable in the AI-assisted live agent chat system of FIG. 1 .
DETAILED DESCRIPTION
[0018] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” An, embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.
[0019] Using an artificial intelligence (AI) system on the server-side of the live-agent interface, mane, of the frequently asked questions from customers may be answered without ever requiring the involvement of a live (i.e., human) agent. The AI system is used as part of an AI-assisted live agent chat system to assist live agents for handling customer inquiries. When the AI system cannot find a suitable response, a live agent can manually interact with the customer. The questions and responses are stored in a knowledge database accessible by the AI system. Specifically, depending on the type of website and profile of the customer base, a certain percentage of the questions normally presented to the live chat agent will be similar. These questions can be matched to a scripted natural language regular expression (search expression) on the server side. A response can be retrieved from a search of the knowledge database and then presented.
[0020] For example, for an e-commerce customer support system common responses answering questions about pricing, shipping, return policy and payment types, along with one or more matching search expressions, would be programmed into the knowledge database used by the AI system to implement the AI-assisted live agent chat system. Each time one of the questions is posed by the customer, the AI system can provide a response to the question, allowing the live agent to focus on more intricate or detailed questions from other customers.
[0021] In addition to the filtering of and responding to individual customer questions, the AI system has the ability to alert the live agent of chat sessions that need attention and can automatically enable a response based on keywords, or whether an answer is found. The live agent also has the ability to monitor ongoing AI-supported chat sessions and intercede at the live agent's choosing. The live agent can then allow the AI system to respond automatically when the agent feels the difficult part of the interaction with the customer has been handled.
[0022] The live agent is able to both type responses to the customer in addition to pushing pre-scripted responses that are automatically presented to the live agent by the AI system to the customer. These pre-scripted responses result from searches of the knowledge database by the AI system for the live agent and can supplement the live agent responses.
[0023] Other features include the ability to re-pool chat sessions into the chat system that are no longer chatting and/or needing monitoring, the ability to transfer chat sessions to other live agents (either with the AI system on or off) and the ability to manually end chat sessions if the live agent feels the conversation has been completed.
[0024] FIG. 1 illustrates a system diagram 100 in which an AI-assisted live agent chat system may be implemented in accordance with one aspect of the present disclosure, including a server system 110 having a chat server 120 for hosting an AI system 122 and a knowledge database 124 , and a web server 130 having an e-commerce engine 132 . A plurality of clients 152 - 152 n are coupled for communicating with the server system 110 through a network 140 . As described herein, a user, using software on a client computer such as a browser 162 on the client 152 , interacts with the server system 110 . Multiple server systems and clients, as well as other computer systems (not shown may also be coupled to the server system 110 . Also, the e-commerce engine 132 interacts with other application software on the web server 130 and the chat server 120 to perform the AI-assisted live agent chat system functionality as described herein, including receiving requests for Web pages from one or more client computers, generating and transmitting the necessary information for rendering the web pages on client computers (along with the client-side code that is deployed to manage chat windows), and receiving the results therefrom. The e-commerce engine 132 may access and present information from, as % ell as store information into, an e-commerce database (not shown). In certain applications where there is no e-commerce engine, the web pages containing the client-side code deployed to trigger the chat window may be provided directly by the web server 130 . Further, although the server system 110 is presented as two servers; with the web server 130 being hosted by one entity, and the chat server 120 including the AI system 122 being hosted by yet another entity, the AI-assisted live agent chat system functionality provided herein may be deployed using a single server or may be spread over multiple systems.
[0025] As described herein, the user may interact with the information stored in server system 110 through browser software. The browser presents a graphical user interface (GUI) to the user. In the following description, the GUI is implemented using one or more web pages (which may be referred to as “pages,” “screens,” or “forms”) provided by the web server 130 accessible by the user using any Internet web browser software, such as the Internet Explorer™ browser provided by Microsoft Corp., on a client computer such as the client 152 . In another embodiment, one or more custom software programs can be created to implement the system described herein. Of course, the web server 130 may itself have browser software installed on it so as to be accessed by a user. Further, throughout the description of the various embodiments of the invention herein, references are made to the user performing such actions as selecting buttons inputting information on forms, executing searches or updates. In one approach, these actions are generated by the user during the user's interaction with the browser. For example, one or more pages described herein are electronic forms (e.g., chat windows) that include fields in which the user may type. Once the user has provided such data, the user may select a button or link on the page to submit the information (e.g., a message) and cause an update of the chat server 120 with the information. For example, the browser will send the web server 130 the information retrieved from the user using the electronic form, which will cause the chat server 120 to be updated.
[0026] In the illustrated embodiment, the network 140 represents a variety of networks that may include one or more local area networks as well as wide area networks. The functionality provided by the chat server 120 , the web server 130 , the plurality of clients 152 - 152 n , as well as by any other computer systems necessary in the AI-assisted live agent chat system may be implemented using a computer system having the characteristics of the computer system described further herein. It should be noted, however, that the specific implementation of the computer system or systems used to describe the present system is not to be limiting unless otherwise specifically noted. For example, the functionality provided by the chat server 120 and the web server 130 may be combined in one computer system. Further, the functionality provided by the chat server 120 and the web server 130 may be distributed over several computer systems.
[0027] The following description is an exemplary operation of the AI-assisted live agent chat system where a customer, using the browser 162 on the client 152 , interacts with the AI-assisted live agent chat system implemented using the server system 110 . In one aspect; the interaction between the customer and the AI-assisted live agent chat system comprises a series of transmitted statements or questions, with one or more messages being provided by the AI-assisted live agent chat system. The customer may also be queried for more information by a the live agent or the AI system 122 . Each message sent from the client-side software (e.g., the browser 162 ) to the server application will be serviced by the server system 110 (e.g., the chat server 120 ), in accordance with the process as illustrated in FIG. 2 .
[0028] FIG. 2 illustrates au exemplary process 200 of the operation of the AI-assisted live agent chat system for supporting an interaction (e.g., a chat session) between a customer on a website hosted on the web server 130 and a live agent on the backend, with the AI system 122 of the chat server 120 handling a set of commonly asked questions and the live-agent being requested to interact with the customer when the AI system 122 is not able to address the message sent by the customer. The interaction between the customer, the AI system 122 and live agent occurs through the use by the customer of a chat window located in a web page, which is further described with reference to a screen capture 300 in FIG. 3 of a customer chat GUI presented to the customer as veil as through the use by the live agent of an agent control panel located in a web page, which is further described with reference to a screen capture 400 in FIG. 4 of an agent interface GUI presented to a live agent.
[0029] Beginning with step 202 , the customer enters text into a text entry box 312 of a chat window 310 in a web page 302 . The chat window 310 is the customer's view into, and interface for, the chat session. The customer is able to enter text and press a “send” button 314 or hit “enter” to deliver the text to the AI-assisted live agent chat system. Responses from the AI-assisted live agent chat system are displayed in the customer chat window 310 in a customer message display 316 . In one aspect, the functionality of the customer chat window 310 is implemented through a client-side script that runs on a client such as the client 152 . In addition, the chat session that is displayed in the customer chat window 310 , as triggered by the web pages transmitted to the client 152 by the web server 130 , is hosted by the chat server 120 . Thus, as described herein, the live agent and the AI system 122 interacts with the customer through the chat server 120 which itself reaches the customer through the browser 162 on the client 152 to implement the client-side customer experience.
[0030] Once a message has been received from the customer, the AI-assisted live agent chat system will prepare a response. In one aspect, the AI-assisted live agent chat system is able to operate in three modes to respond to the chat messages sent from the customer: (1) a fully automated chat mode, without intervention from the live agent (unless an AI disabling event occurs); (2) a fully live agent-based mode, where the live agent is fully engaged in the chat session without input from the AI system 122 ; or (3) a mixed mode where the AI system 122 provides proposed responses to the live agent, but the live agent is the one that controls the transmission of the chat message to the customer.
[0031] Based on whether the AI system 122 is enabled or disabled, as determined in step 204 , the chat message is either routed directly to the live-agent for handling in step 212 , or the AI system 122 will attempt to find an appropriate response in step 206 , respectively. Assuming it is determined that the AI system 122 is not disabled for this chat session in step 204 the AI system 122 will attempt to find a match for the text sent by the customer in step 206 .
[0032] In one approach, the AI system 122 is an automated response chat system implemented using artificial intelligence. The AI system 122 is able to interact with customers through a plurality of predefined rules and keywords. Specifically, the AI system 122 provides responses based on an analysis of the messages that the customer sends using responses stored in the knowledge database 124 . The analysis is performed using on keywords and rule matches. The list of keywords and rules are configured according to a customer support campaign. In addition to the preprogrammed keywords and rules, the AI system 122 may augment its responses by detecting whether and even how the customer has interacted with the AI-assisted live agent chat system to determine what responses may be provided to the customer.
[0033] For example, the AI system 122 may detect how the customer has interacted with e-commerce engine 132 and the web server 130 to attempt to ascertain what issues the customer may have with the web site. Thus, if the customer abandoned an e-commerce transaction during a check-out process, the AI system 122 may engage the customer to offer the customer a discount on shipping. In contrast, if the customer abandoned the e-commerce transaction during a review of a product, the AI system 122 may offer the customer a discount on the product or other incentive (including, again, discounted shipping). In another example, where the customer has, or is about to complete the e-commerce transaction, what the customer has purchased during the e-commerce transaction may affect the operation of the AI system 122 so that the AI system 122 agent may offer additional services (e.g., offering professional installation if the customer has purchased a wall-mountable flat-screen television set) or products (e.g., offering cables or other accessories for the television set).
[0034] Although the examples above are specific to e-commerce transactions such as online shopping, the scope of how the AI-assisted live agent chat system is not limited to these examples or, as certain provided examples have detailed, even limited to the “recapture” of customer interactions. Thus, for example, the term “e-commerce” as applied in the description contained herein should be applied broadly as to an, interaction with a customer, whether that interaction is related to the purchasing of a product or service or a filling out of a form for information gathering purposes. The specific information, promotion or marketing response implemented by the AI system 122 may be customized as needed.
[0035] Moreover, in addition to generating messages based on an analysis of the customer's action, the AI system 122 can also generate messages based on an analysis of the live agent's messages, and, in general, the interaction between the customer and the live agent.
[0036] If a matching response is found in step 206 , then an appropriate response is formulated in step 208 . In one aspect, if the AI-assisted live agent chat system is in the fully automated chat mode, as determined in step 210 , then the AI system 122 is allowed to send the formulated response automatically to the customer in step 212 . In this mode, the AI system 122 will send the response without any need for live agent intervention.
[0037] In one aspect, an unrecognized customer input will disable the AI system 122 . Further, the AI system 122 is also configured to detect a match of keywords or rules on the customer's input that will trigger the automatic disabling or the AI system 122 . Thus, where either: (1) the AI system 122 has not found a match to provide a proposed response, or (2) the AI system 122 has found a keyword or rule match that is purposefully designated to disable the AI system 122 —both or which are referred to as AI system disabling events—in one aspect the automated response feature of the AI system 122 will be disabled automatically in step 214 . Further, the AI system 122 can be manually disabled by the live agent for one or more chat session.
[0038] Referring to FIG. 4 , an agent interface window 402 illustrates a list of currently live chat sessions 420 that is assigned to the live agent. Each chat session is assigned with a chat identifier number (“chatID”), a source from which the chat session was initiated (“site”), an IP of the client associated with the chat session (“ip”), and a timer tracking the amount of time since the last activity in the chat session (“timer”). Chat sessions that are being handled successfully by the AI system 122 , such as a chat session 424 with a ChatID “178919397”, are displayed in the list as entries with white backgrounds. The live agent may: select a chat session, such as a chat session 424 with a ChatID “178919301”, to monitor the interaction between the customer and the AI system 122 using a live agent chat window 430 . The selected chat session 424 is indicated in the list of currently live chat sessions 420 by a hi-lighted entry.
[0039] In step 216 , the message from the customer will be routed to the live agent assigned to the chat session along with an alert notifying the live agent that this particular chat session requires manual intervention. Thus, in the event there is a detection of either: (1) an AI system disabling event such as a customer text input that disables the AI system 122 , or (2) a customer input on a chat session where the AI system 122 has been disabled by the live agent, the live agent is alerted through a red background for the chat session 422 in the list of currently live chat sessions 420 , as illustrated in a screen capture 500 of FIG. 5 . In one aspect, the live agent may also be alerted by a sound or by bringing the chat window associated with the chat session (e.g., the agent chat window 430 ) to focus in the live agent interface window 402 .
[0040] In step 218 the live agent may prepare and send a message to the customer in a variety of manners if the AI system 122 is disabled from sending automatic responses to the customer. Referring again to FIG. 4 , in one aspect the live agent can create a message to the customer by entering text into a text entry box 434 directly without the assistance from the AI system 122 . The live agent may also insert additional text into the message to be sent to the customer by copying and pasting text from other windows, such as a search window (not shown) used by the search agent to search the knowledgebase 124 for additional information, or any other windows (not shown) displayed to the live agent.
[0041] If, as determined in step 210 , the AI system 122 is enabled to generated proposed messages but is disabled from automatically sending a response to the customer, then the AI system 122 will present the one or more responses generated in step 208 to the live agent in step 220 as the message is routed to the live agent in step 216 . As discussed herein, the AI system 122 can generate proposed messages or responses based on an analysis of the customer's messages or interactions between the customer and the AI-assisted live agent chat system. The analysis may include an analysis of the customer's interaction with the web server 130 as tell as the information stored about the customer. For example, it may be that the customer has a history of shipping using methods that allow tracking. Thus, if the AI-assisted live agent chat system is engaged to respond to the customer based on a question from the customer about shipping or order status, then the AI system 122 can use this information to propose a list of responses having to do with the status or shipment of the order. Any proposed responses are listed in a proposed message panel 440 in the live agent chat window 430 . The live agent is able to use the text that is listed in the proposed message panel 440 by selecting a “Queue lines” link displayed next to each proposed message such as links 440 and 448 for proposed messages 442 and 446 , respectively. In one aspect, one or more proposed messages may be queued by the live agent to be sent to the customer: with or without additional editing or typing by the live agent. In another aspect, the AI-assisted live agent chat system will automatically send the proposed message associated with the link that is selected by the live agent without the live agent having to press the “Enter” key or selecting the “Send” button 438 .
[0042] Once a message has been generated by the live agent—either with or without the use of the proposed responses from the AI system 122 —the live agent can send the message either by pressing the “Enter” key on a keyboard or clicking on a “Send” button 438 . In one aspect the text that is in the text entry box 434 is first sent to the chat server 120 which in turn sends it to the client 152 to be displayed on the customer message displays 316 in the customer chat window 310 . In another aspect, the client 152 may be sent the message directly without the use of the chat server 120 . The message is also displayed in a live agent message display 432 .
[0043] In one aspect, the messages sent to the customer, whether they are generated by, the AI system 122 , typed by the live agent, or created from a combination of the two, are presented in the customer chat window 310 without differentiation. In other words, both the AI system 122 generated and live agent created answers are displayed the same way to the customer, with no indication of how the answer was generated. Thus, the customer should not be able to detect how the responses the customer receives are generated. However, the messages sent by the backend system (e.g., the live agent or the AI system 122 ) will be displayed differently from the customer to allow the customer to visually differentiate the messages.
[0044] In one aspect, the AI-assisted live agent chat system tracks details of the text in the live agent message display 432 in the live agent chat window 430 so that the presentation of the text is based on whether the text was generated by the AI system 122 or the live agent (e.g., by the live agent typing the text). This allows the live agent (or another entity such as a supervisor, a person debugging the system, or a person improving the matching script) to determine how the text in the messages sent to the customer as generated. For example, any text typed or pasted into the window by the live agent may be colored in blue, while any text generated by the AI system 122 may be colored in green, in addition to any other color that may be assigned to the customer to differentiate the text from each other. Thus, how well the AI system 122 is operating, at least with respect to the successfulness of its response rate can be determined by someone looking at the color of the text in the live agent message display 432 . Further, the log may be analyzed by the AI system 122 to continually update the knowledge database 124 automatically with updated or new responses.
[0045] As detailed in FIG. 4 , other features provided in the live agent interface window 402 to the live agent includes the ability to set a status of the live agent to being available or unavailable with an availability toggle 410 . The live agent is also able to set a maximum number of chat sessions the live agent wishes to have displayed in the list of currently live chat sessions 420 at one time using a “Max Chats” setting 412 in the live agent interface window 402 . An “Auto Focus” checkbox 414 will bring the window for the chat session that has last received a message to be brought to into focus and brought in front of other windows. A “Who's Online” button 416 will indicate who is online, while a “LogOut” button 418 will allow the live agent to logout of the system Further, in addition to the ability offered to the live agent of being able to type responses in the text entry box 434 , the live agent chat window 430 also provides the live agent the ability to perform: a re-pooling of a chat session by which a currently idle chat is sent back into the system but not closed, through the use of a “Re-Pool” button 460 ; a transferring of a chat session from the current live agent to another live agent through the use of a “Transfer Chat” button 462 ; and a manual termination of the chat session on both the live agent and customer's side through the use of an “End Chat” button 464 .
[0046] Also, although the automated chat interaction process is repeated ever) time a customer enters text into the chat window, as discussed herein, the live chat agent can intercede at any point in the conversation by using the live agent interface window 402 to override the AI system 122 and manually entering (e.g. typing) text to be displayed to the customer. In one aspect, through the live agent interface window 402 , the live agent has the ability to both enable/disable the AI system 122 for a particular chat session using an AI system toggle 436 in the live agent chat window 430 . Specifically, the live agent can manually disable the AI system 122 through the use of the radio button “AI Off” in the AI system toggle 436 . Once the AI system 122 has been disabled, the live agent can interact with the customer in the chat session and then simply re-enable the AI system 122 using the radio button “AI On” in the AI system toggle 436 if the chat session requires no further manual attention. In one aspect, the AI system 122 may continue to generate one or more proposed responses based on the interaction between the customer and the live agent whether or not the AI system 122 has been enabled.
[0047] It should be noted that chat sessions may be initiated through a variety of events, including a detection of a chat session request by the customer, an event by the customer interacting with the system, or a request from the live agent. Thus, chat sessions are not necessarily only started by a customer.
[0048] FIG. 6 illustrates an example of a computer system 600 in which the features of the present invention may be implemented. Computer system 600 includes a bus 602 for communicating information between the components in computer system 600 , and a processor 604 coupled with bus 602 for executing software code, or instructions, and processing information. Computer system 600 further comprises a main memory 606 , which may be implemented using random access memory (RAM) and/or other random memory storage device coupled to bus 602 for storing information and instructions to be executed by processor 604 . Main memory 606 also may be used for storing temporary variables or other intermediate information during execution of instructions by processor 604 . Computer system 600 also includes a read only memory (ROM) 608 and/or other static storage device coupled to bus 602 for storing static information and instructions for processor 604 .
[0049] Further, a mass storage device 610 , such as a magnetic disk drive and/or a optical disk drive, may be coupled to computer system 600 for storing information and instructions. Computer system 600 can also be coupled via bus 602 to a display device 634 , such as a cathode ray tube (CRT) or a liquid crystal display (LCD), for displaying information to a user so that, for example, graphical or textual information may be presented to the user on display device 634 . Typically, an alphanumeric input device 636 , including alphanumeric and other keys, is coupled to bus 602 for communicating information and/or user commands to processor 604 . Another type of user input device shown in the figure is a cursor control device ( 638 , such as a conventional mouse, touch mouse, trackball, track pad or other type of cursor direction key for communicating direction information and command selection to processor 604 and for controlling movement of a cursor on display 634 . Various types of input: devices, including, but not limited to the input devices described herein unless otherwise noted, allow the user to provide command or input to computer system 600 . For example in the various descriptions contained herein, reference may be made to a user “selecting,” “clicking,” or “inputting,” and any grammatical variations thereof, one or more items in a user interface. These should be understood to mean that the user is using one or more input devices to accomplish the input. Although not illustrated, computer system 600 may optionally include such devices as a video camera, speakers, a sound card, or many other conventional computer peripheral options.
[0050] A communication device 640 is also coupled to bus 602 for accessing other computer systems, as described below. Communication device 640 may include a modern, a network interface card, or other well-known interface devices, such as those used for interfacing with Ethernet, Token-ring, or other types of networks. In this manner, computer system 600 may be coupled to a number of other computer systems.
[0051] Those of skill in the art would understand that information and signals may be represented using any or a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves magnetic fields or particles, optical fields or particles, or any combination thereof.
[0052] Those of skill in the art would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying Evans for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.
[0053] The steps of a method or algorithm described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module ma) reside in RAM memory flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC, The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium ma) reside as discrete components in a user terminal. Moreover, in some aspects any suitable computer-program product may comprise a computer-readable medium comprising codes (e.g., executable by at least one computer) relating to one or more of the aspects of the disclosure. In some aspects a computer program product may comprise packaging materials.
[0054] The teachings herein may be incorporated into (e.g., implemented within or performed by) a variety of apparatuses (e.g., devices). Accordingly, one or more aspects taught herein may be incorporated into a computer (e.g., a laptop), a phone (e.g., a cellular phone or smart phone), a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a global positioning system device, or any other suitable device that is configured to communicate via a network medium.
[0055] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented within or performed by an integrated circuit (“IC”), in access terminal, or in access point. The IC mars comprise a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gale or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute codes or instructions that reside within the IC, outside of the IC, or both. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
[0056] The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present: disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | An artificial intelligence (AI)-assisted live agent chat system allows a single live agent to handle an increased number of simultaneous chat sessions by having an AI system handle the bulk of common, repeat questions. The AI system will allow the live agent to focus his or her attention on the few chat sessions needing unique service and will effectively lower the cost of supporting chat sessions. The server-side technology uses an AI-engine as ell as a live agent backend interface for a site to deliver live-agent experience without the customer having to know whether the answer is from the AI system or from the live agent. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and system for controlling the toner concentration in a developer for developing an electrostatic latent image, and in particular, to a toner concentration control method and system for use in electrophotographic copying machines.
2. Description of the Prior Art
In an electrophotographic copying machine employing the so-called two component developer comprised of toner and carrier beads, it has been known to control the concentration of toner in the developer. One approach to detect the toner concentration of developer relies on a variation in inductance depending on the toner concentration, and another approach is to detect the optical density of a reference pattern formed on a photosensitive drum. Conventionally, the toner concentration was measured by either of these approaches and the thus measured toner concentration was compared with a predetermined reference level at a predetermined interval, and when the measured toner concentration was found to be lower than the reference level, a toner replenishing unit was activated to supply a predetermined amount of toner to the developer.
In this manner, in accordance with the prior art technique, a predetermined amount of toner was replenished every time when the measured toner concentration was found to be lower than the reference level, so that the developer could be prevented from becoming toner scarce condition. However, in accordance with such prior art approach, since the developer was examined at regular intervals as to whether or not its toner concentration was lower than the reference level irrespective of the degree of toner concentration, data processing was carried out unnecessarily, which was a burden to a control unit. Besides, since a predetermined amount of toner was replenished irrespective of the degree of deviation of the detected toner concentration from the reference level, it was often observed that the toner concentration became excessive or too scarce, which thus caused instability in the performance of development.
SUMMARY OF THE INVENTION
In accordance with the principle of the present invention, there is provided a toner concentration control system which comprises a central processing unit (CPU) in which a plurality of control tables are stored. Upon receipt of a signal indicating the size of copy sheet to be used, one of the plurality of tables is selected for use. At the same time, the current level of toner concentration of developer is detected and its detected concentration signal is supplied to the CPU. Thus, the CPU determines the degree of deviation of toner concentration from a predetermined reference level and the CPU causes a toner replenishing unit to operate varyingly in accordance with the degree of deviation thus determined. Based on the detected level of toner concentration, the frequency of concentration detection is varyingly determined. In general, the frequency of detection increases as the deviation from the reference level increases. Moreover, the larger the deviation of detected toner concentration from the reference level, the more the amount of toner to be replenished. In this manner, in accordance with the present invention, the toner concentration of developer can be maintained at constant at all times, so that the quality of developed image can always be maintained high.
It is therefore a primary object of the present invention to obviate the disadvantages of the prior art as described above and to provide an improved method and system for controlling the toner concentration of developer.
Another object of the present invention is to provide a toner concentration control method and system capable of varyingly setting the concentration detecting period depending on the size of copy sheet to be used.
A further object of the present invention is to provide a toner concentration control method and system capable of varyingly setting an amount of toner to be replenished.
A still further object of the present invention is to provide an improved toner concentration control method and system accurate and reliable in operation.
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 schematic illustration showing the overall structure of a toner concentration controlling system constructed in accordance with one embodiment of the present invention; and
FIG. 2 is a flow chart useful for explaining the operation of the system shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is schematically shown a toner concentration control system constructed in accordance with one embodiment of the present invention. As shown, there is provided a developer tank T for containing therein a quantity of developer as located adjacent to a photosensitive drum D which is driven to rotate in a direction indicated by the arrow at constant speed. As well known in the art, around the drum D is disposed various components, such as a corona charger and an image exposing unit, for forming an electrostatic latent image on the outer peripheral surface thereof. These components are normally disposed upstream of the developer tank T with respect to the direction of rotation of the drum D. Typically, additional components, such as an image transfer unit and a cleaning unit, are disposed around the drum D and downstream of the developer tank T with respect to the direction of rotation of the drum D.
Within the tank T and adjacent to the drum D is disposed a developing sleeve B which is rotatably supported and normally driven to rotate, counterclockwise in the illustrated embodiment. Inside of the sleeve B is disposed a magnet roll so as to provide a magnetic field at the outer peripheral surface of the sleeve B so that magnetic brush comprised of a two-component developer including toner and carrier beads is formed on the outer peripheral surface of the sleeve B. As is well known, the magnetic brush is formed such that the toner electrostatically clings to the carrier beads which are magnetically attracted to the outer peripheral surface of the sleeve B. A toner container C is provided at the top of the tank T and a toner replenishing roller R provided with a plurality of longitudinal grooves in its outer peripheral surface is provided at the bottom of the toner container C, so that the toner stored inside of the container C is supplied into the tank T as the roller R is driven to rotate by means of a motor M. As will become clear later, in accordance with the present invention, the motor M drives to rotate the roller R at different speed so that the amount of toner to be replenished per unit time may be set differently.
Also provided in the tank T is a toner concentration detector 1 which is comprised of an inductance element for detecting the toner concentration of the developer in the tank T as derived from the value of detected inductance. The detector 1 is provided as mounted on a separator S which has its one end in sliding contact with the outer peripheral surface of the sleeve B on which the magnetic brush of developer is formed. Thus, the developer attracted to the sleeve B in the form of magnetic brush is brought into contact with the outer peripheral surface of the drum D on which a latent image to be developed is formed as the sleeve B rotates in the counterclockwise direction. And, as the sleeve B further rotates, the developer remaining on the sleeve B is removed from the sleeve B and then slides down along the inclined separator S.
The detector 1, on the other hand, is connected to a frequency-to-voltage converter 2 where a signal from the detector 1 is converted into an analog signal. The f/V converter 2 is connected to a CPU 5 through a variable gain amplifier 3 and an A/D converter 4. When the toner concentration of the developer inside of the tank T is at a predetermined reference level, the variable gain amplifier 3 supplies an output voltage of 2 V. The output voltage from the amplifier 3 is converted into a 4-bit digital signal by the A/D converter 4, whereby a deviation from the reference level or 2 V is converted into the 4-bit digital signal using 0.25 V as one unit. The thus obtained digital singal is then supplied into the CPU 5.
Also connected to the CPU 5 is a copy sheet size detector 6 which detects the size of copy sheets to be used and supplies this information to the CPU 5. Also provided is a counter 8 as connected to the CPU 5 and it counts the number of copies developed by the developer stored in the tank T. The CPU 5 has a memory in which a plurality of predetermined tables for use in toner concentration control operation are stored. It is to be noted that such a memory may be provided external to the CPU 5. Two examples of toner concentration control tables stored in the CPU 5 are shown below.
TABLE I______________________________________Bit Time Period Rotational Speed Detection8 4 2 1 per copy of Motor Interval______________________________________0 0 0 0 off off 110 0 0 1 0.5 sec 60 rpm 110 0 1 0 0.5 sec 60 rpm 110 0 1 1 0.5 sec 60 rpm 110 1 0 0 1.0 sec 60 rpm 110 1 0 1 1.0 sec 60 rpm 80 1 1 0 1.0 sec 60 rpm 80 1 1 1 1.0 sec 90 rpm 81 0 0 0 1.0 sec 90 rpm 51 0 0 1 1.5 sec 90 rpm 51 0 1 0 1.5 sec 90 rpm 51 0 1 1 1.5 sec 90 rpm 51 1 0 0 1.5 sec 90 rpm 51 1 0 1 2.0 sec 90 rpm 51 1 1 0 2.0 sec 90 rpm 21 1 1 1 2.0 sec 120 rpm 2______________________________________
TABLE II______________________________________Bit Time Period Rotational Speed Detection8 4 2 1 per copy of Motor Interval______________________________________0 0 0 0 off off 110 0 0 1 0.25 sec 60 rpm 110 0 1 0 0.25 sec 60 rpm 110 0 1 1 0.25 sec 60 rpm 110 1 0 0 0.5 sec 60 rpm 110 1 0 1 0.5 sec 60 rpm 80 1 1 0 0.5 sec 60 rpm 80 1 1 1 0.5 sec 90 rpm 81 0 0 0 0.5 sec 90 rpm 51 0 0 1 0.75 sec 90 rpm 51 0 1 0 0.75 sec 90 rpm 51 0 1 1 0.75 sec 90 rpm 51 1 0 0 0.75 sec 90 rpm 51 1 0 1 1.0 sec 90 rpm 51 1 1 0 1.0 sec 90 rpm 21 1 1 1 1.0 sec 120 rpm 2______________________________________
One of the toner concentration control tables as shown in Tables I and II above is selected for use depending on the size signal from the size detector 6. As shown in Tables I and II, the time period and the rotational speed of motor M for replenishing toner from the container C to the tank T increases proportionately as the deviation of the detected toner concentration from the reference level increases. On the other hand, the detection interval or the number of copies to be made between the two successive detecting operations decreases and thus the detection frequency increases as the deviation of detected toner concentration from the reference level increases. Put it another way, as the detected level of toner concentration becomes further away from the predetermined reference level, the detection of toner concentration is carried out more often.
The CPU 5 presets a count in the counter 8 depending on the deviation of the detected toner concentration from the reference level, and, thus, the count to be set in the counter 8 corresponds to the number of copies to be made between the two successive concentration detection operations. Every time when the counter 8 counts up to this preset value, the counter 8 is reset, and, at the same time, the counter 8 supplies as its output a sampling signal for causing the CPU 5 to detect the deviation of the current toner concentration from the reference level.
The control system also comprises a toner replenishing amount adjusting circuit 9 as connected to the CPU 5 for adjusting the amount of toner to be supplied in a single replenishing operation. Upon detection of a deviation of the current toner concentration from the reference level, a desired control data including the time period and rotational speed of motor M for replenishing toner from container C to the tank T is selected from the selected table and temporarily set in the toner replenishment adjusting circuit 9. Based on the thus set data, the circuit 9 activates the motor M through a toner replenishment driving circuit 10 so that the motor M drives to rotate the roller R for a selected time period at a selected rotational speed. As a result, a desired amount of toner is supplied to the tank T from the toner container C within a desired time period.
Now, the operation of the toner concentration control system illustrated in FIG. 1 having the structure as described above will be described with reference to a flow chart shown in FIG. 2.
When a copy button is depressed after turning on of a power switch of an electrophotographic copying machine in which the system of FIG. 1 is incorporated, the counter 8 is cleared and the size detector 6 detects the size of copy sheets selected for use. And, at the same time, the developer inside of the developer tank T is passed through the toner concentration detector 1 so that the detector detects the current toner concentration and this information is supplied to the CPU 5 in the form of a toner concentration deviation signal indicating how much the current concentration deviates from the reference level. On the other hand, in accordance with a copy size signal from the detector 6, the CPU 5 selects an appropriate one of the toner concentration control tables stored therein as described before. And, then, from the thus selected table, the CPU 5 chooses appropriate control information as to time period and rotation speed and supplies this information to the adjusting circuit 9.
Under the circumstances, as the copying operation has been initiated, the counter 8 starts to count the number of copies made. Upon completion of the first copy, if the toner concentration of the developer within the tank T is maintained at the reference level, the toner concentration deviation signal is "0,0,0,0" so that the copying operation proceeds without toner replenishing operation. On the other hand, if the toner concentration of the developer inside of the tank T has been found to deviate from the reference level, then, upon depression of the copy button for the next copying operation, the toner replenishing roller R is driven to rotate for a selected time period at a selected rotational speed based on the information currently set in the adjusting circuit 9, as described previously. Thus, a desired amount of toner is supplied to the tank T from the container C within a desired time period.
For example, if the toner concentration of the developer inside of the tank T deviates far from the reference level, whereby the toner concentration deviation signal indicates "1,1,1,1", then the rotation speed of motor M or roller R is set at 120 rpm and the time period for toner replenishment operation is set at 2 seconds, so that a relatively large amount of toner flows from the container C into the tank T for a short period of time. Accordingly, the toner concentration of the developer inside of the tank T rapidly increases toward the reference level. In this case, the count of 2 is preset in the counter 8 so that the toner concentration detecting operation is carried out every two copies made. In other words, under the condition, every time when the count of counter 8 reaches "2" as the copying operation is carried out, the counter 8 supplies as its output a sampling signal to the CPU 5 so that the CPU 5 implements the toner concentration detecting operation using the concentration detector 1.
However, since the toner concentration of the developer inside of the tank T has risen to approach the reference level due to the previous toner replenishing operation, e.g., the toner concentration deviation signal indicating "1,0,0,0", the condition of toner replenishing operation is reset, for example, such that the rotational speed of motor M or roller R is 90 rpm and the time period for toner replenishing operation is 1 sec. Thus, the toner replenishing operation now proceeds at a lower rate, and, at the same time, the count of "8" is preset in the counter 8. Then, the count of the counter 8 reaches "8" as the copying operation proceeds, the count is cleared and then "11" is preset in the counter 8 while detecting again the current deviation of toner concentration from the reference level. If the deviation has been found to be very small, such as "0,0,1,1", then the operating condition for motor M or roller R is reset to 60 rpm and 0.5 sec. Under the condition, a relatively small amount of toner is supplied from the container C to the tank T thereby making the toner concentration of the developer inside of the tank T arrive at the intended reference level. If the toner concentration of the developer inside of the tank T arrives at the reference level, "11" is preset in the counter 8, so that every time when the counter 8 counts up to "11", the CPU 5 carries out the toner concentration detecting operation.
If a copy has been made for an original of high image density, the toner within the developer inside of the tank T has been consumed significantly thereby causing to lower the toner concentration abruptly. Under the condition, when the toner concentration detecting operation is carried out, there is obtained a toner concentration deviation signal indicating a large deviation from the reference level. Even in this case, in accordance with the principle of the present invention, a relatively high rotational speed of the motor M or roller R and a relatively long time period of toner replenishing operation are set by the CPU 5 so that a relatively large flow of toner is established from the container C to the tank T. Accordingly, the toner concentration of the developer inside of the tank T can be rapidly recovered to the intended reference level, which, in turn, allows to maintain the developed image constant in density.
Now, if the size of copy sheets to be used has been changed, for example, from A4 to B4, then this fact is detected by the size detector 6 which supplies an appropriate size signal to the CPU 5. Thus, the CPU selects an appropriate one of the plurality of toner concentration control tables stored therein for use.
As described above, in accordance with the preferred embodiment of the present invention, it is so structured that the toner concentration detecting operation is carried out for every number of copies which is selected in inverse proportion to the degree of deviation of the detected toner concentration from the reference level, so that the unnecessary data processing is precluded as much as possible thereby lowering the burden of the control system. Besides, it is so structured that the amount of toner to be supplied in a single toner replenishing operation is varyingly set in proportion to the degree of deviation of the detected toner concentration from the reference level, so that the toner concentration of the developer within the tank T can be restored to the reference level as quickly as possible. Moreover, the flow rate of toner to be replenished is optimally set depending on the amount of toner to be replenished, so that there is created no overshoot in the replenishing operation, which has an advantage of stabilizing the developing operation.
In the system shown illustrated in FIG. 1, the detector 1 is provided for directly detecting the toner concentration of the developer. Alternatively, the present invention is also applicable to a system in which the toner concentration of developer is detected indirectly, for example, by forming a developed reference pattern on the peripheral surface of the drum D and measuring the optical density of the thus formed reference pattern using a sensor comprised of an L.E.D. and a light receiving element.
While the above provides a full and complete disclosure of the preferred embodiments of the present invention, various modifications, alternate constructions and equivalents may be employed without departing from the true spirit and scope of the invention. Therefore, the above description and illustration should not be construed as limiting the scope of the invention, which is defined by the appended claims. | A toner concentration control method and system for controlling the toner concentration of a developer which includes toner and carrier for use in electrophotography. A controller, typically including a central processing unit or CPU, first determines a degree of deviation of the current toner concentration from a predetermined reference level and then replenishes the toner to the developer at an optimal replenishing condition which is varyingly set in accordance with the detected degree of deviation. In the preferred embodiment, the flow rate of toner to be supplied and time period of replenishing operation are varyingly set. Besides, the frequency of toner concentration detecting operation is also varyingly set so as to alleviate the load of the CPU. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority of Provisional Patent Application No. 60/525,501 entitled “A Method and Apparatus for Logging, Warning, and Treatment of Seizures Using Cardiac Signals”, filed Nov. 26, 2003, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to medical devices and, more specifically without limitation, to implanted medical devices.
2. Description of the Related Art
Epilepsy affects about 2.3 million Americans, and its direct and indirect annual costs amount to approximately $12.5 billion. Although anti-epileptic drugs are useful, 20-30% of persons are not helped by them and up to 30% of those treated have intolerable or serious side effects.
Recently published studies demonstrate the importance of quantitative analysis of brain signals for automated warning and blockage of seizures, optimization of existing therapies and development of new ones. Cardiac activity is under cerebral control. That is, certain changes in global, regional or focal brain activity, either physiological or pathological, modify heart activity. Epileptic seizures are one of the pathological brain states associated with changes in heart activity including but not limited to changes in heart rate, most frequently an increase and referred to as ictal tachycardia, or in other indices of cardiac function such as R-R variability. The incidence of heart changes increases as the seizure spreads outside its site of origin to other brain regions being, for example invariably present in all subjects with primarily or secondarily generalized tonic-clonic seizures (“convulsions”), in whom purportedly, most or all of the brain is involved. These changes reflect shifts in the ongoing interplay between sympathetic and parasympathetic influences, which can be quantified using time or frequency domain methods of analysis. For example, tachycardia precedes electrographic onset of temporal lobe seizures by several seconds, as ascertained via scalp electrodes (EEG), while combined activation of parasympathetic and sympathetic systems as estimated by using spectral analysis of oscillations in R-R intervals at respiratory and non-respiratory frequencies, may be detectable minutes in advance of seizure onset. Since these changes may precede visible electrographic or behavioral manifestations indicative of seizures and even of the so-called “aura,” they may have predictive value. Real-time prediction or detection of epileptic seizures, based on extracerebral sources such as the heart, is of great clinical and practical value as it obviates the reliance on cerebral signals which are highly complex and of high dimensionality and whose origin may not only be difficult to localize but quite often requires invasive intracranial implantation of electrodes or other sensors.
While methods presently exist to detect seizures using cardiac signals and quantify their characteristics, for example as described in U.S. Pat. No. 6,341,236 which is incorporated herein by reference in its entirety, no system for logging the times of seizures and their quantitative characteristics, such as date and time of occurrence, and duration based on the degree of cardiac changes, and for using this information in the objective assessment of seizure frequency and of therapeutic intervention, presently exists. This is partially due to the impact of artifacts (noise) on EKG signal analysis which can lead to inaccuracies in heart rate assessments.
Thus, the need exists for a system and method for logging seizures, or other events originating in the brain that impact cardiac activity, and associated event characteristics such as frequency, duration, intensity, and severity. Moreover, this system and method needs to be robust in the presence of artifacts or other sources of noise. The need also exists for a minimally invasive system and method to provide effective and objective means for assessing the efficacy of therapies used to control seizures.
SUMMARY OF THE INVENTION
Changes in heart activity associated with seizures can be used to automatically and in real-time detect the seizures, quantify their frequency, duration, intensity, or severity as reflected in the cardiac signal changes, predict their electrographic or clinical onset in a subset of cases, and control the seizures via therapeutic intervention. The present invention enables the logging of this information and its utilization to objectively assess the efficacy of an applied therapy. To accomplish this task with improved robustness in the presence of signal artifacts or noise, the invention can utilize EKG and complementary information obtained from other signals representative of cardiac function such as the phonocardiogram (PKG), echocardiogram, or ultrasound.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a schematic representation of a system for receiving and analyzing cardiac signals and detecting and logging seizures according to the present invention.
FIG. 2 shows an EKG signal corrupted by artifact at the start of a seizure.
FIG. 3 illustrates simultaneously recorded EKG and PKG data and the ability of PKG to provide complementary information regarding cardiac function contained therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Changes in certain types of global, regional or focal brain activity, either physiological or pathological, modify heart activity. Epileptic seizures are one important example of a pathological brain state with demonstrated association to changes in heart activity. The incidence of heart changes increases as the seizure spreads outside its site of origin to other brain regions being, for example invariably present in all subjects with primarily or secondarily generalized tonic-clonic seizures (“convulsions”), in whom purportedly, most or all of the brain is involved. Real-time prediction or detection, and quantitative analysis of epileptic seizures, based on extracerebral sources such as the heart, is of great clinical and practical value as it obviates the reliance on cerebral signals which are highly complex and of high dimensionality, and whose origin may not only be difficult to localize but quite often requires invasive intracranial implantation of electrodes or other sensors. The invention disclosed herein, and depicted schematically in FIG. 1 , utilizes information present in signals 101 representative of the cardiac activity state, fed to system 100 that performs real-time quantitative analysis of this information in a processor 102 . This processor analyzes and measures relevant changes in the cardiac activity state in order to predict or detect and quantify underlying events occurring in the brain of a subject. The system is configured to include a clock 103 and non-volatile memory 104 to enable these events and relevant data and information about associated event features to be logged. These features may include, but are not limited to, start time, end time, or duration of detected cardiac changes which provide information about underlying seizures or other brain events, the frequency or relative intensity of these changes, and the evolution of the distribution of such features as inter-beat intervals. These and other features representative of cardiac state well known to one skilled in the art, such as heart rate and heart rate variability measures, can be measured and relevant changes logged. The system can be configured with a communication interface 105 that allows the subject or other user to access information from the logs stored in non-volatile memory 104 and/or to program parameters used in the operation of the system 100 , including parameters involved in the analysis of cardiac signals performed using processor 102 .
While methods presently exist to detect seizures using cardiac signals and quantify their characteristics, for example as described in U.S. Pat. No. 6,341,236, no system presently exists for logging these quantitative characteristics, such as times of occurrence, durations and degrees of cardiac changes associated with seizures or other underlying brain events and for using this information in objective assessment of the neurological disorder and of efficacy of therapeutic intervention. This is partially due to the impact of artifacts (noise) on EKG signal analysis which can lead to inaccuracies in heart rate assessments.
Seizures often are associated with movement, muscle, and other artifacts that can obscure or distort the EKG making it difficult or impossible to extract the important information contained in the contaminated signals. FIG. 2 illustrates an EKG signal from a subject just before and during the onset of an epileptic seizure in which there is significant artifact present as the seizure begins. This artifact makes it difficult to determine from this signal precisely when heart beats are occurring. One strategy to overcome noise is to simultaneously acquire other cardiac signals such as PKG to take advantage of the fact that these other signals have different sensitivities than EKG to certain types of noise. This approach increases the information content about the state of the heart, and indirectly about the state of the brain, and decreases the probability of signal loss or degradation by noise. FIG. 3 illustrates the differential sensitivity to noise: the EKG signal shown is contaminated by muscle artifact, a common source of noise during seizures, and is not easily recognizable visually or using spectral signal analysis while the simultaneously recorded PKG is virtually immune to this type of noise. The two arrows in FIG. 3 annotate time points when R-waves in the EKG are obscured by muscle artifacts; FIG. 3 also displays the simultaneously recorded PKG signal which is immune to this type of artifacts.
The PKG can be used instead of EKG for tracking heart rate and its variability given the high temporal correlation between the Si and the QRS complex. Simultaneous use of PKG and EKG allows the system access to good quality information for more complete and accurate tracking of the cardiac system dynamics and, indirectly, of brain dynamics effecting the heart. Those skilled in the art can appreciate that many other types of physical or chemical heart signals suitable for use with implantable devices can also be used in addition to, or instead of, EKG and PKG for this purpose.
In view of the clinical importance of real-time automated quantitative seizure analysis and the greater signal-to-noise ratio and shorter propagation time from source to sensor, and ease of use of heart signals (electrocardiogram, EKG, or phonocardiogram, PKG) compared to scalp signals (EEG) or intracranial recording of electrical signals (ECoG), the approach of the present invention disclosed herein makes use of these signals for a) the invasive or non-invasive extracerebral, real-time automated detection of seizures based on heart signals; b) the logging of frequency, date/time of occurrence, relative intensity and relative duration of seizures; c) the anticipation of electrographic or behavioral seizure onset and/or loss of function in a subgroup of subjects with epilepsy, for automated warning and other useful purposes; and d) the automated delivery of a selected therapy, either contingent or closed-loop. Additionally and of equal importance is the ability to detect, in real-time, cardiac rhythm abnormalities, which may be life-threatening and which are temporally correlated with seizures or occur in between seizures and to provide appropriate intervention such as pacing or defibrillation.
Use of cardiac signals such as EKG and/or PKG for the automated detection of seizures, and in certain cases for the anticipation of their onset, will complement and, in a subgroup of subjects with pharmaco-resistant epilepsy, may replace scalp or intracranial (invasive) acquisition of cortical signals for automated warning and/or therapy delivery and in either case will allow for seizure logging and other tasks. One of the main advantages of using EKG/PKG for seizure detection is that unlike methods based on cortical signals recorded either directly from the cortex, which requires a craniotomy or burr hole, or indirectly from the scalp (EEG), it is not critically dependent on accurate placement of electrodes and, in a subset of cases, the onset of heart changes may even precede scalp or behavioral changes providing yet another advantage.
Heart signals, can be obtained from several body sites obviating, in a subgroup of patients, the need for surgery, thus decreasing the inconvenience, stress, cost, potential morbidity and recovery time associated with such procedures. Furthermore, the wealth of commercially available, low power, implantable devices for analysis and control of heart signals can be easily leveraged for this application. Another advantage of EKG over EEG or ECoG is its lower dimensionality and relative simplicity wherein a single channel recording is sufficient for capturing all of the information necessary for the tasks at hand.
Those skilled in the art can appreciate that in certain cases or situations, dual, simultaneous monitoring of brain and heart may be necessary or useful to improve detection of changes in either organ or to improve the efficacy of control measures. Also, undesirable changes in heart activity caused by abnormal brain activity may be better controlled by directing the intervention to the brain rather than to the heart. For instance, while asystole caused by seizures can be controlled using a demand pacemaker, a more definitive and rational approach is to prevent or block asystole-inducing seizures. It is clear that the dynamic interactions between heart and brain can be exploited to detect changes and to control them by monitoring either organ or both and by applying control to either of them, or to both.
Frei and Osorio and others, see for example U.S. Pat. No. 6,341,236, have disclosed methods for automated EKG analysis and detection of cardiac signal changes associated with epileptic seizures. The methods developed by Frei and Osorio are especially well-suited for seizure detection using heart signals, a task which requires analysis of data over very short windows (1-2 sec). The length requirements of other methods for standard low/ultra-low frequency band power assessments of heart rate variability, typically five-minute segments assumed to be stationary, are much longer than the duration of a seizure or a dangerous cardiac abnormality that may lead to sudden death. In addition, the assumptions regarding stationarity of the system/signal are counter to the well-known nonstationarity of the normal cardiac system. Given these deficiencies, it is therefore impractical to apply methods of heart signal analysis that require long segments of data, minutes for example, for the detection of phenomena for which warning and control must take place in a very short time period (e.g., under ten seconds) for purposes of safety and efficacy. Another advantage of the methods of the present invention is that they can be used to quantify the intensity, type, and evolution of cardiac changes, which in turn may be used to detect and estimate the duration and intensity of underlying brain state changes whether physiological or pathological. The changes in heart activity that may indicate a possible onset of a seizure (a pathologic state change) include, but are not limited to, changes in heart rate and heart rate variability and their interrelationship, rhythm, morphology of the P-QRS-T complex or of the length of the different intervals (e.g., Q-T).
One skilled in the art can appreciate that, in addition to the aforementioned methods, a number of methods for detection and analysis of cardiac signal changes exist in prior art, many of which have been implemented in hardware, software, or in a hybrid configuration, and which can be used, for example, to obtain the time of each heart beat as well as the interbeat (e.g., R-R) interval. One skilled in the art will appreciate for example, that the R-R interval times or other quantities representative of cardiac state may be processed/analyzed using methods in the time or frequency domains to generate a multitude of derivative signals/sequences or ratios from which a wealth of information can be obtained about the heart, including instantaneous heart rate (IHR), its average rate in fixed or moving windows of any desired length, and measures of heart rate variability (“HRV”) (e.g., standard deviation of means of R-R intervals in a moving window, or the second derivative of instantaneous heart rate, etc.) on any desired timescale but with emphasis on those timescales suitable for seizure detection. Changes in the distributions of these, or any other quantity derived from the time-of-beat sequence, as time evolves can be detected and quantified in real-time, for example using the “lambda estimator” as disclosed in Nikitin et al, U.S. Patent Application Publication No. 20030187621, or other statistical methods. Stereotypical patterns, if found in these data, may be learned over time as more seizures are recorded and analyzed. For example, cardiac data from a subject can be used to establish normal or baseline patterns for this subject and compared against moving windows of new data to determine deviations from normalcy or baseline, proximity to dangerous or undesirable patterns, and to quantify these deviations. Degree of absolute or relative changes in heart rate, heart rate variability, and their interrelationship, ST-wave depression, and QT prolongation are examples of such quantities. The time of specific changes and their duration and/or intensity are obtainable from these analyses. As in the aforementioned Nikitin et al reference, one skilled in the art will appreciate that the analysis of interest can be multifactorial and/or multidimensional. For example, U.S. Pat. No. 6,341,236 of Osorio and Frei disclosed that changes in the relationship between IHR and HRV provide information about heart function which is not obtainable if IHR and HRV are analyzed separately.
The aforementioned lambda estimator provides one of many possible examples illustrating how statistical changes in feature signals, even when multi-dimensional, obtained from cardiac recordings, such as EKG, can be quantified as they evolve. By applying thresholding techniques or, more generally, by identifying values of quantified features that are associated with particular cardiac or body states, e.g., seizures, the start and end of these state changes can be localized in time and their relative intensity quantified.
These analyses may also be applied to PKG signals in order to detect similar, complementary, or different changes reflective of heart state. Other measures that may be used by the present invention include but are not limited to: duration including time of onset and termination of changes in heart rate or in any of its derivatives; changes in heart rate variability or in any of its derivatives; changes in rhythmicity or in generation and conduction of electrical impulses; or changes in the acoustic properties of heart beats and their variability. It will be appreciated that additional information may be obtained through analysis of occurrence times of other EKG waveforms such as Q-T intervals, changes in spectral properties of the EKG or signal morphology, as well as time-of-beat information obtained from PKG such as s1-s1 intervals, amplitude (magnitude) of the signal, or changes in its waveshape and/or spectral characteristics, etc. For example, changes in the magnitude or rate of change of the high- and low-frequency components of the heart beat, using autoregressive, Fast Fourier, wavelets, Intrinsic Timescale Decomposition (U.S. patent application Ser. No. 10/684,189, filed Oct. 10, 2003), or other suitable techniques, may be used alone or combined with other cardiac measures to increase the sensitivity, specificity, and/or speed of prediction or detection of seizures or in their ability to quantify brain state changes. Other measures derived from the raw or processed signals that may be of additional use in the present invention include, but are not limited to, analysis of entropy, correlation dimension, Lyapunov exponents, measures of synchronization, fractal analysis, etc.
The real-time prediction, detection and quantification of seizures that is possible by using the methods disclosed herein and/or associated systems may be adapted or tailored to fit an individual's cardiac state change patterns or characteristics, thereby increasing sensitivity, specificity or speed of detection of state changes. The performance of the detection methods, such as sensitivity, specificity and speed, may be enhanced, if necessary, by characterizing baseline patterns for a subject and comparing them against moving windows of current data to determine and quantify deviations from baseline and proximity to patterns indicative of state change. These can be used, together with the frequency, intensity, and duration of heart signal changes, time to maximal deviation from baseline, time to recovery to baseline rates, for assessing a patient's condition, safety risks, and even efficacy of therapy. Moreover, degree of conformance to stereotypical cardiac signal patterns that may be associated with certain seizure types can be used to infer other severity-related measures such as degree of seizure spread in the brain. Simultaneous recording and analysis of other non-cardiac signals, such as muscle, joints, skin or peripheral nerves, may also improve prediction, detection and quantification of state changes. For example, the recording, analysis, and comparison of changes in cardiac signals during the state change of interest, e.g., seizures, to that obtained during activities such as exercise, can increase their sensitivity, specificity, and/or detection speed for real-time seizure detection purposes, or for detecting changes of body state. These processes may be carried out on- or off-line.
The information about heart state provided by the present invention can be used to compute seizure index, which is defined as the fraction of time spent in a seizure over a moving window of a given size. The information can also be used to determine seizure severity, e.g., using the product of intensity and duration. These and other measures may be logged as part of the present invention (or later computed from other logged information) and can provide valuable diagnostic and prognostic information, as well as information regarding efficacy of any therapy attempted during the period of monitoring/analysis. The set of logged information stored by the present invention can also be used to develop models that may allow or refine seizure prediction or detection (using cardiac signals or in general) and shed light on an individual's seizure dynamics.
The implantable or portable device implementing the present invention is configured to include a real-time clock and a rewritable, non-volatile memory, as well as one or more sensors for use in recording EKG, PKG and/or other representative signals indicative of cardiac function and/or state, such as echocardiogram, ultrasound, blood pressure, blood flow rate or volume, heart muscle tension, etc., and processing components capable of receiving, conditioning, and analyzing the EKG and/or PKG signals to detect and/or quantify events of interest such as seizures. The logging process consists of reading the real-time clock each time an event or cluster of events of a certain designated type occurs, and logging the clock time and variables associated with the quantification of the event to the non-volatile memory. These variables may include but are not limited to information obtained through processing of the signals, and/or the raw signals themselves, i.e., “loop recordings” of events.
The system of the present invention may be further configured with an output mechanism to: a) warn the subject of an impending seizure or other type of detected event such as a cardiac arrhythmia, low system battery, full memory, etc., and b) deliver a selected therapy to the subject when heart activity reaches or exceeds safe or pre-specified limits. For example, Osorio and Frei in U.S. Pat. No. 6,341,236 disclose a means to trigger the pacing of the heart in the event of a seizure detected by analysis of EKG. Osorio et al., in U.S. Pat. No. 5,995,868, disclose a method of treating seizures by, among other methods, stimulating the brain, heart and/or vagus nerve when a seizure is detected. The output mechanism may include or be connected to a neurostimulator and/or a pacemaker to control brain and/or heart activity within prespecified tolerable/safe limits. Commonly used types of warnings include audio alarms with varied tones and/or combinations of short and long sounds, other types of acoustic devices, LED or other visual displays, e.g., flashing lights, etc., low-voltage so-called “tickler” stimulus, and communication with external devices, e.g., triggering an external device such as “calling 911,” etc.
Any additional implanted or portable device may also use the non-volatile memory for storing information about events through the use of a uni- or bi-directional communications protocol. For example, a pacemaker that detects an unusual EKG rhythm or heart beat pattern could trigger the device described herein that an event has occurred and potentially could communicate other features/attributes of the event, such as type, severity, etc., to the device for logging purposes. The system may also contain a display, or means to be externally interrogated, to review and/or download the information it has stored and/or logged for review by the user, subject, or physician. In addition to logging seizures or other events of neurological origin which impact the cardiac system, the system and method of the present invention can be used to objectively assess the efficacy of therapies used to control the occurrence or severity of these events. For example, when a subject takes medication in order to control his seizures, the availability of a seizure log that includes their time of occurrence, severity, and other features can be analyzed in reference to administration times and concentrations of medication or other therapy, which also can be logged by the system via the communication interface described above. Such comparisons enable the modeling and objective efficacy assessment of the effect of the therapy on the system. For instance, the seizure frequency measure plotted against the level of medication expected to be present in the subject's system as time evolves allows the user to optimize dosing levels and times to minimize seizure frequency.
Therapies administered to the subject based on the cardiac signal change may also include administration of a drug or medicament, features of which may include medicament type, dose, administration site, time of delivery, duration of delivery, rate of delivery, frequency of delivery, and inter-delivery interval. Therapies administered to the subject based on the cardiac signal change may include thermal regulation of the brain, features of which may include time of delivery, duration of delivery, rate of delivery, frequency of delivery, inter-delivery interval, administration site, intensity of therapy, and size of region affected by thermal regulation.
It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown. | A system and method for analyzing and logging changes in brain state of a subject for administering therapy to the subject based on the at least one cardiac signal wherein the system and method comprises the steps of receiving at least one cardiac signal of the subject into a processor, analyzing the cardiac signal to detect at least one cardiac signal change indicative of a brain state change, and logging at least one characteristic of the detected signal change or the brain state change. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for producing 100% cotton spunlace non-woven cloth and 100% cotton mixed with synthetic fibers spunlace non-woven cloth, a method for producing spunlace non-woven cloth with X-Ray detectable element and spunlace non-woven cloth with X-Ray detectable element produced by such method.
BACKGROUND OF THE INVENTION
[0002] At present, medical non-woven cloth is made of synthetic fiber. The components of synthetic fiber are commonly 70% Rayon and 30% Polyester (these are coming from petroleum). The raw material resources are non-renewable, the production cost is high, after using, the destroying cost is high, and it damages the environment. At the same time, some patients are sensitive to this material. Therefore the prospect of synthetic fiber non-woven medical dressing is not optimistic. However, the nature spunlace non-woven cloth medical dressing will be widely used, because the raw material of this non-woven cloth is naturally planted cotton; the raw materials are abundant and recycled. It is simply dealt with, as well as being soft, protecting environment, having good absorbency, no toxic, no stimulation, no sensibility, being convenient and comfortable to use. At present, the method for producing spunlace non-woven cloth is, clearing cotton—degreasing—bleaching—drying—carding cotton—spreading the web—water jetting—drying—rolling the finished products The disadvantages of this producing method are with more procedures, high cost and bigger waste of power. As this producing method is degreasing and bleaching the cotton fiber first, therefore the cotton fiber is not smooth, and it is difficult to spread fiber into the web. With this method, the impurity content of finished products is high, so the quality cannot be guaranteed. In a word, it is much more wasteful by this process, the good ratio of finished products is low, and the production cost is high, therefore the price is terribly high. In this case, till today, this type of spunlace non-woven cloth is not used widely.
[0003] In the medical trade gradually uses more and more non-woven cloth. The non-woven cloth is folded in multi layered dressing to use in hemostasia, examining blood, sucking blood or body fluid in operation. In operations, the dressings are dropped in human body because of subjective or objective reasons. And the dressings which are soaked with blood or body fluid have the similar color with the body tissue in human body or in the wound, which is hard to discover. Therefore they are difficult to discover so that they are left over in the human body. Moreover, they are difficult to be checked out after the wound is sewn up, unless cutting the seam again. Leaving the dressings in the human body is a very dangerous accident. If it cannot be checked out in time and be cleared, it will cause worse of patient's condition and even death. The disadvantage of present non-woven is that when they are left over in the human body, they are difficult to be checked out.
SUMMARY OF THE INVENTION
[0004] Accordingly, a primary objective of the present invention is to provide a method for producing spunlace non-woven, as well as reduce the consuming of energy sources, cut down the producing cost and decrease the impurity content of products to enable the hygiene of finished products and greatly reduce the bacteria content of products.
[0005] Another object of the present invention is to provide a method for producing water-jet non-woven that can be detected by X-Ray machine, which makes the spunlace non-woven can be irradiated by X-Ray machine and accurately detected the position and size of the leftover as well as removed immediately in case of being left over in the body of patients.
[0006] Still another object of the present invention is to provide a kind of producing method of spunlace non-woven that can be detected by X-Ray machine, which makes the X-ray detectable elements and non-woven cloth combine firmly and reliably, as well as being easy to use and no negative effect.
[0007] The further object of the present invention is to provide a kind of non-woven which can be detected by X-Ray machine. The producing cost of this non-woven is low and can make sure the X-ray detectable element will not break off and the quality is good.
[0008] For attaining the above-mentioned object, A method for producing spunlace non-woven cloth, A method for producing spunlace non-woven cloth with X-Ray detectable element, spunlace non-woven cloth with X-Ray detectable element thereby are featured as follows:
[0009] A method for producing spunlace non-woven cloth comprised the following steps in sequence:
A, clearing cotton: Loose the raw materials, get rid of impurity and mix; B, carding: Further get rid of impurity, clear and card the fiber smoothly; C, Spreading the web: For the fiber which has been carded, reciprocated and intervened or overlapped spreading the web according to direction of fiber; D, Water jetting: Employ jets of water at high pressure to puncture the fiber web, to entangle the cotton web. E, Degreasing: Remove the waxiness or grease from the non-woven cloth after water jetting; F, Bleaching: Bleach the spunlace non-woven cloth according to the requirements of pharmacopoeia to make it meet the medical standard. F, Rolling the finished products.
[0017] Before the water jetting procedure, the raw materials used have not been degreased.
[0018] The raw materials mentioned are pure cotton or cotton adds chemical fiber, for example, cotton adds polyester, cotton adds synthetic cotton, cotton adds viscose, cotton adds polypropylene fiber, cotton adds wood pulp fiber, etc.
[0019] Before clearing cotton there also can be a procedure which makes simple water treatment and boiling treatment on the above stated pure cotton or synthetic cotton.
[0020] To make optimum choose, the carding comprises the following steps:
[0021] 1) loosing: Loose the raw materials to make into single fiber, making them enter the carding machine smoothly;
[0022] 2) carding cotton: Continuously carry on one time or more times of carding on the single fiber, to remove the foreign materials, for example, cotton shells, etc.
[0023] For the present technology craftwork, as before water jetting only the procedure of clearing cotton has the function of removing impurity, the pressure of removing impurity in water jetting procedure is increased and impurity is apt to remain. In addition, there is no procedure to clear the relatively short and bad cotton fibers in the present technology. And the water jetting can only remove some cotton knots rather than remove short fibers. As a result, in the last tension test the relatively short and bad cotton fibers will cause the whole product not to meet the medical standard because they have small tension. The present invention adds carding procedure after clearing cotton. It uses carding machine to card the raw cotton to further remove impurity and select the superior, to remove some exiguous impurities (including cotton knots) and improve the cleanliness of products as well as clear and filter the relatively short and bad cotton fibers. This can ensure the fiber tension of cotton web entering the next procedure, therefore reducing the rejecting rate caused by defects of impurity, tensile force and so on in the latter procedure, that is, reducing the defect ratio of the products of the whole procedure.
[0024] The disadvantage of the prior art is that it degreases bleaches and dries the raw cotton after simple cleaning cotton, that is, to bleach all the sundries and impurities. Thus the characteristic of this bleaching craft is that it consumes too much energy, the cost is too high, and the unwanted 15-18% of the impurities are also bleached. The second aspect is that hygiene is the most important for medical dressings, but the process that first degreases and bleaches the cotton, later clears cotton, spreads web and water jets pollutes cotton another time. At the same time, in the present technology it is to degrease first and then water jet, so the absorbability of bleached cotton web is strengthened; as there are many exiguous impurities in the cotton web and these impurities are absorbed by the cotton webs that have strong absorbability after degreasing, so they are not easily rinsed out even in water jetting. The present invention rearranges the sequence of degreasing and water-jetting procedure, that is, to first water jet and then degrease. The raw material used before water jetting is purely natural cotton which has been not degreased and bleached. Can first remove the exiguous impurities in the cotton web and then degrease, which avoids the problem that the exiguous impurities are absorbed and not easily removed. This further improves the cleanliness of products and reduces the scrap ratio or rework ratio because of containing impurity.
[0025] Therefore the present invention not only reduces the procedures, but also improves the finish goods ratio of the whole procedure, accordingly reduce the producing cost and economize energy sources.
[0026] In order to achieve the above object, the present invention provides a method for producing spunlace non-woven cloth with X-Ray detectable elements comprises the following procedures: crossly spreading the web, water jetting, degreasing and rolling the finished products. And before rolling the finished products, plant or spray the X-ray detectable elements which can be detected by X-ray machine into the fiber web or onto the surface of fiber web of non-woven, or heat on the surface of spunlace non-woven cloth.
[0027] The above method for producing spunlace non-woven cloth with X-Ray detectable elements includes the following detailed procedures in sequence: clearing cotton—carding—spreading the web—water jetting—bleaching—drying—rolling the finished products. Specially, before water jetting, plant or spray the X-Ray detectable element threads into the fiber web or onto the surface of fiber web. Then make them into non-woven cloth with X-Ray or X-Ray detectable elements through water jetting, degreasing and bleaching. The prefer method is: in the procedure of crossly spreading the web, uniformly plant or spray the one piece or more pieces of X-Ray detectable element threads into the fiber web or onto the surface of fiber web. Then make them into non-woven cloth with X-Ray or X-Ray detectable elements through water jetting, degreasing and bleaching.
[0028] The method for planting or spraying the X-Ray detectable element onto the surface of fiber web includes the following procedures in sequence: clearing cotton—carding—spreading the web—water jetting—bleaching—drying—rolling the finished products. Specially, after water jetting, heat the X-Ray or X-Ray detectable elements onto the surface of non-woven. The prefer method is: after water jetting, uniformly heat one piece or more pieces of X-Ray detectable element threads on the surface of fiber web. Then make them into non-woven cloth with X-ray or X-Ray detectable elements through degreasing and bleaching. Said X-Ray detectable elements are X-Ray detectable element threads or X-Ray detectable element slices shaped as lines or tapes.
[0029] In order to achieve the above object, the present invention also provides a kind of spunlace non-woven cloth with X-Ray detectable elements, which comprises fiber web and X-Ray detectable elements that can be detected by X-Ray machine. The X-Ray detectable elements mentioned tangle with the single fiber in the cotton fiber web. Fiber web refers to the cotton fiber web formed by pure cotton or the fiber web mixedly formed by cotton adding a small part of synthetic fiber.
[0030] Further, the mentioned X-ray detectable elements are detectable element threads shaped as lines or tapes. There is at least one piece of X-Ray detectable element thread.
[0031] The present invention provides reliable assurance for using pure cotton or synthetic cotton non-woven at ease in the future. And also it resolves the problem of adding X-Ray or X-Ray detectable elements at the same time of producing non-woven, thus avoiding the additional procedure of adding X-Ray or X-Ray detectable elements when producing finished products. The present invention improves the quality of products or goods, and reduces elementary polluting bacteria of the finished products, which is really the biggest quality assurance for medical sterile products. The simultaneous finish of non-woven production and adding of X-Ray detectable elements reduces the stretch and out of shape of non-woven and form of flying wadding because of additional procedure and ensure the appearance quality of the products. Before water jetting, plant or spray the X-Ray detectable element threads to the fiber web. After the water jetting procedure, the X-ray detectable element threads and cotton fiber or synthetic fiber tangle together, thereby making the X-ray detectable element threads not easily break off and break down, which improves the safety of products or goods.
[0032] The invention, together with other objects and advantages thereof, will be best understood by reference to the following description taken in conjunction with the accompanying drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a producing procedure flow chart of a embodiment of the present invention;
[0034] FIG. 2 is a producing procedure flow chart of a preferred embodiment of the present invention;
[0035] FIG. 3 is the product sketch map which adding X-Ray detectable element threads when crossly spreading the web in the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] Referring to FIG. 1 , the manufacturing procedure of spunlace non-woven medical dressing comprises the following steps:
[0037] 1) preparing the materials: Prepare the raw materials, namely 100% natural cotton or a small part of synthetic fiber adding natural cotton;
[0038] 2) clearing cotton: First remove impurity of raw materials with cotton clearing machine to sift the foreign materials in the raw materials and loose the raw materials. This procedure is an acknowledged technology and it is the same with the present technology;
[0039] 3) carding: It includes loosing and carding cotton. Loosing is to loose the raw cotton after clearing cotton with carding machine to make into single fiber state. This is necessary for removing small impurities and carding cotton. Carding cotton is to comb the single fiber smoothly with carding machines according to the lengthways of raw cotton fiber to make the tensile force between fibers exert to the biggest. At the same time, small impurities (such as cotton knots) and short fibers in the raw cotton will be filtered in the process of carding. The task of removing impurities is mainly taken by puncturing roller part. It can remove 50% to 60% of impurities fed in cotton layer. Another small part of dust enters cotton covering board to be removed or fall in other parts. In the process of carding, long fibers and tin forest needle tooth are exposed to many areas, so they are easy to be taken away by the tin forest needle tooth; whereas short flosses and fibers often stay on the cover board needle tooth and are pressed into the needle tooth, and form cover board cotton then being removed. In order to further remove impurities, short flosses and fibers, as a preferred embodiment of the present invention, the carding of this procedure includes one time, two times or more times of carding cotton depending on specific products.
[0040] 4) Crossly spreading the web: For the fiber which has been preliminarily carded, reciprocated and intervened overlapped spreading the web depending on the direction of fiber according to the requirements of grammage specifications of products. The main purpose is to strengthen the tension between fibers (including cotton or synthetic fibers) and ensure the tensile strength of the ultimate finished products.
[0041] 5) feeding the fiber web: Fiber web includes cotton web, and the web which is composed of cotton and synthetic fiber;
[0042] 6) Pre-wetting the fiber web: To make sure a good moist condition before water jetting;
[0043] 7) water jetting: Employ the high pressure water needle of water jet machine to produce jet of water at high pressure to make obverse and inverse water jetting to the fiber web, which enables the fibers in the fiber web to fully tangle, further reinforce the tension between fibers and improve the tensile strength of the ultimate finished products. At the same time, the small impurities (including cotton knots) are eliminated, purity is further improved and the good ratio of products is improved. This procedure carries on one time, two times or more times of water jetting according to the different purposes of products. When water jetting for two times, rubbing may produce flosses in the course of using. The more times of water jetting, the better is the shaping of products and tension of fiber; however, if the time of water jetting is too much, the production cost will be increased, and as to the water jetting of more than three times the effect is very small. Therefore, as the preferred embodiment of the present invention, the water jetting of this procedure contains 1 to 3 times. The water jet machines used are web-leveling water jet machine and round drum water jet machine. The web-leveling water jet machine and round drum water jet machine can be alternately used, and can also be continuously used. For example, when water jetting for 3 times, the water jet machine in the first time of water jetting is web-leveling water jet machine, in the second time is round drum water jet machine, and in the third time is web-leveling water jet machine. The cotton webs pass three water jet machines one after the other in the equal speed. Different speeds are set according to the thickness of cotton web. For different specifications of products, the pressure of water jetting is also different, which is commonly controlled at about 120 Kg/cm 2 . The distance of spunlaces is within 1.8 m. Water jetting of three times can further make sure the good shape of appearance, thus resolves the bad shaping of the traditional spunlace non-woven medical dressing and very well deal with the problem that rubbing may produce flosses in the course of using products.
[0044] 8) ginning to dry: Extrude the water in the fiber web after water jetting to make the next procedure convenient;
[0045] 9) degreasing: Remove the waxiness or grease on the cotton fiber to strengthen the water absorbency of products. This procedure is the same with the degreasing procedure of the present technology.
[0046] 10) bleaching: Improve the whiteness of the raw cotton fiber. This procedure is the same with the bleaching procedure of the present technology.
[0047] 11) drying;
[0048] 12) rolling the finished products.
[0049] In sum, the key point of the present invention is that for the first time it directly uses the raw materials which have not been degreased and bleached in the production of non-woven cloth. It breaks the traditional procedures and boldly adopts the most advanced carding technology aiming at cotton, which is to first make into spunlace non-woven cloth and then carry on degreasing and bleaching. This reduces the impurity content and improves the tensile strength of products, thus improving the qualification rate of the finished products, reducing the working procedures, greatly economizing the energy consumption and cutting down the production cost. Besides, the main raw material of the direct products of the present invention is purely natural cotton, so they have the advantages of being soft, having good skin tolerance, no toxic, no stimulation, no sensibility, having good absorbency, convenient and comfortable to use.
[0050] Referring to FIG. 2 , that is the preferred embodiment of a method for producing spunlace non-woven cloth with X-Ray or X-Ray detectable elements. The producing procedure of spunlace non-woven cloth with X-Ray or X-Ray detectable elements comprises the following steps:
[0051] 1) preparing the materials: The same with the above embodiment.
[0052] 2) clearing cotton: The same with the above embodiment.
[0053] 3) carding: The same with the above embodiment.
[0054] 4) crossly spreading the web: At the same time of spreading the web, uniformly plant or spray the X-Ray detectable element threads as shaped solid line state with compressed gas to the process of spreading web; or spray the liquid X-Ray absorbing materials to the process of spreading web, to solidify into the X-ray detectable element threads. At the same time, for the fiber which has been preliminarily carded, reciprocated, intervened or overlapped spreading the web depending on direction of fiber according to the requirements of grammage specifications of products. X-ray detectable element threads can be planted or sprayed in the middle of fiber web, and can also be placed on the surface of fiber web.
[0055] 5) water jetting: The same with the above embodiments.
[0056] 6) degreasing;
[0057] 7) bleaching;
[0058] 8) rolling the finished products.
[0059] X-Ray detectable elements refer to substances which are made of X-Ray absorbing materials or can be detected by X-Ray machine. They can be shaped as thread, tape, block or slice.
[0060] Referring to FIG. 3 , the products sketch map after adding X-Ray detectable element threads in crossly spreading the web. X-ray detectable element thread 1 locates in the fiber web 2 or on the surface of fiber web 2 uniformly or in the equal space between, X-Ray detectable element thread 1 should have at least one piece. The number of X-Ray detectable element thread 1 can vary according to requirements, to make sure that each medical dressing has X-ray detectable element thread on it. After water jetting, X-ray detectable element thread 1 tangle up with the single fiber in the fiber web 2 , so the X-ray detectable element threads are not easily broken off and broken down.
[0061] The main component of X-Ray detectable element thread is barium sulphate. It mixes with chemical fiber, cotton fiber or nonpoisonous plastics to make into X-Ray detectable element thread. X-Ray detectable element threads can also be made of other X-Ray absorbing materials.
[0062] This embodiment is to first water jet and then degrease, which is different from the prior procedure of non-woven cloth (the prior procedure is to first deal with raw materials and then water jet, and the finished products form after water jetting). The producing method of this embodiment can first eliminate the small impurities in the cotton web and then degrease, thus avoiding the problem that the small impurities are not easily eliminated because they are absorbed by cotton fibers after degreasing, which further improves the cleanliness of products, decreases the probability of scrapping or doing over again because of containing impurity and reduces production cost.
[0063] The X-Ray detectable element threads can also be added in the procedure of crossly spreading the web, and can also be added after water jetting. It includes the following steps:
[0064] 1) Preparing the materials; The same with the above embodiment.
[0065] 2) Clearing cotton; The same with the above embodiment.
[0066] 3) Carding; The same with the above embodiment.
[0067] 4) Spreading the web; The same with the above embodiment.
[0068] 5) Water jetting; The same with the above embodiment.
[0069] 6) Heat the X-ray detectable element threads to the surface of non-woven cloth. The heat refers to make hot heating, hot pressing and ultrasonic wave treatment to the X-ray detectable element threads and stick them to the surface of non-woven cloth.
[0070] 7) Degreasing; The same with the above embodiment.
[0071] 8) Bleaching; The same with the above embodiment.
[0072] 9) Rolling the finished products. | A method for producing spunlace non-woven cloth includes the following steps: clearing cotton—carding—spreading the web—water jetting—bleaching—drying—rolling the finished products. This method improves the good ratio of the finished products of the whole procedure, reduces the producing cost, economizes raw materials and save the power as well as reduces the impurity content of products and ensures the hygiene of finished products and greatly reduces the bacteria content. Moreover, the direct products of the present invention have the advantages of being soft, having good skin tolerance, no toxic, no stimulation, no sensibility, having good absorbency, convenient and comfortable to use. | 3 |
BACKGROUND OF THE INVENTION
Avermectin compounds have been known for some time as potent anthelmintic agents and substantial research has been carried out preparing various substituted variations of such compounds. Some of the avermectin compounds have become commercially available as potent broad-spectrum anthelmintic and antiparasitic agents in animal health and agriculture. See US 4310519 to Albers-Schonberg et al and 4199569 to Chabala et al. Applicants are not aware of any avermectin compounds where the 23-ring carbon has been replaced by a heteroatom.
SUMMARY OF THE INVENTION
This invention is concerned with the preparation of 23-nor-23-thia avermectin compounds that are prepared from avermectin natural products or derivatives thereof in a series of reactions that first opens the avermectin spiroketal ring containing the C23 ring carbon atom. The 23-carbon atom is then replaced by a sulfur containing group which may also have additional substituents thereon and the compound is then ring closed to prepared the desired compounds. The 23-nor-23-thia compounds are highly effective anthelmintic and antiparasitic agents in animal health and agriculture.
DESCRIPTION OF THE INVENTION
The compounds of the instant invention are best realized in the following structural formula. ##STR1## where R 1 and R 2 are independently hydrogen, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 1 -C 10 alkoxy C 1 -C 10 alkyl or C 1 -C 10 alkylthio C 1 -C 10 alkyl group; a C 3 -C 8 cycloalkyl or C 5 -C 8 cycloalkenyl group, either of which may optionally be substituted by methylene or from 1 to 3 of C 1 -C 4 alkyl groups or halo atoms; phenyl, phenoxy, C 1 - 10 alkyl phenyl, C 2 -C 10 alkenyl phenyl, C 2 -C 10 alkynyl phenyl, substituted C 1 -C 10 alkyl wherein the substituents independently are 1 to 3 of C 1 -C 5 alkyl, C 3 -C 8 cycloalkyl or substituted C 1 -C 10 alkyl wherein the substituents are independently 1 to 3 of hydroxy, halogen, cyano, C 1 -C 5 alkyl thio, C 1 -C 5 alkyl sulfinyl, C 1 -C 5 alkyl sulfonyl, amino, C 1 -C 5 mono or dialkyl amino, C 1 -C 5 alkanoyl amino or C 1 -C 5 alkanoylthio; or a 3 to 6 membered oxygen or sulfur containing heterocyclic ring which may be saturated or fully or partly unsaturated and which may optionally be substituted independently by 1 to 3 of C 1 -C 5 alkyl or halogen; or
R 3 is hydroxy, C 1 -C 5 -alkoxy, hydroximino or --O--C 1 -C 5 alkyl-hydroximino;
R 4 is hydrogen, halogen, hydroxy, C 1 -C 5 alkanoyloxy, (C 1 -C 5 -alkoxy) n where n is 1-4, ##STR2## where R 5 is hydroxy, oxo, (C 1 -C 5 alkyl) m amino, C 1 -C 5 alkanoyl amino, (C 1 -C 5 alkyl) (C 1 -C 5 alkanoyl) amino, C 1 -C 5 alkyl-S(O) m , hydroxy substituted C 1 -C 5 alkyl S(O) m , where m is 0, 1 or 2 or (C 1 -C 5 -alkoxy) n where n=1-4.
In the foregoing structural formula and throughout the instant specification the alkyl, groups are intended to be of either a straight or branched configuration. The (C 1 -C 5 alkoxy) n is intended to include alkoxy and polyalkoxy groups of either a straight or branched configuration and where the polyalkoxy group can independently vary as to carbon atom content and configuration.
Preferred compounds of the instant invention are realized in the foregoing structural formula wherein:
R 1 and R 2 are independently hydrogen, C 1 -C 5 alkyl, C 2 -C 5 alkenyl, C 1 -C 5 alkoxy, a C 5 -C 6 cycloalkyl or C 5 -C 6 cycloalkenyl group, either of which may optionally be substituted by methylene or from 1 to 3 of C 1 -C 4 alkyl groups; phenyl, phenoxy, C 1 - 5 alkyl phenyl, C 2 -C 5 alkenyl phenyl, substituted C 1 -C 5 alkyl wherein the substituents independently are 1 to 3 of C 1 -C 3 alkyl, C 1 -C 3 alkyl thio, C 1 -C 3 alkyl sulfinyl, C 1 -C 3 alkyl sulfonyl, or a 5 to 6 membered oxygen or sulfur containing heterocyclic ring which may be saturated or fully or partly unsaturated; or
R 3 is hydroxy, C 1 -C 3 -alkoxy, C 1 -C 3 -alkanoyloxy hydroximino or --O--C 1 -C 5 alkyl-hydroximino;
R 4 is hydrogen, halogen, hydroxy, C 1 -C 3 -alkanoyloxy, (C 1 -C 3 alkoxy), where n is 1-2, ##STR3## where R 5 is hydroxy, C 1 -C 3 alkyl amino, C 1 -C 3 alkanoyl amino, (C 1 -C 3 alkyl) (C 1 -C 3 alkanoyl) amino, C 1 -C 3 alkyl-S(O) m , hydroxy substituted C 1 -C 3 alkyl S(O) m , where m is 0, 1 or 2 or (C 1 -C 3 -alkoxy) n where n=1-4.
More preferred compounds of the instant invention are realized in the foregoing structure where:
R 1 is hydrogen, C 1 -C 4 -alkyl;
R 2 is hydrogen, C 1 -C 5 alkyl, C 2 -C 5 alkenyl, C 1 -C 5 alkoxy, a C 5 -C 6 cycloalkyl or C 5 -C 6 cycloalkenyl group, phenyl, substituted C 1 -C 5 alkyl wherein the substituents independently are 1 to 3 of C 1 -C 3 alkyl; or
R 3 is hydroxy, hydroximino or --O--C 1 -C 2 alkyl-hydroximino;
R 4 is hydrogen, halogen, hydroxy, C 1 -C 2 -alkanoyloxy, (C 1 -C 3 alkoxy) n where n is 1-2, ##STR4## where R 5 is hydroxy, C 1 -C 2 alkyl amino, C 1 -C 2 alkanoyl amino, (C 1 -C 2 alkyl) (C 1 -C 2 alkanoyl) amino, C 1 -C 2 alkyl-S(O) m , hydroxy substituted C 1 -C 2 alkyl S(O) m , where m is 0, 1 or 2.
Additional preferred compounds of this invention are:
23-nor-23-thia-24-desmethyl-25-des(2-butyl) invermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-methyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-ethyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-isopropyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-tert-butyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-sec-butyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-[2-(4-methylpent-2-enyl)] ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-cyclohexyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-phenyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-(4-fluoro)phenyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-(4-methoxy)phenyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl) ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-methyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-isopropyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-tert-butyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-cyclohexyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-sec-butyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-ethyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-[2-(4-methylpent-2-enyl)] ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-25-phenyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl) ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-methyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-isopropyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-tert-butyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-cyclohexyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-sec-butyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-ethyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25des(2-butyl)-25-[2-(4-methylpent-2-enyl)] ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-phenyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-(4-fluoro)phenyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-4"-deoxy-4"-epi-amino-25-isopropyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-4"-deoxy-4"-epi-acetylamino-25-tert-butyl ivermectin B1;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-4"-deoxy-4"-epi-acetyl(methyl)amino-25-cyclohexyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-5-deoxy-5-ketoxime-25-sec-butyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-ethyl ivermectin B1 monosaccharide;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-[2-(4-methylpent-2-enyl)] ivermectin B1 aglycone;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-13-O-methoxymethyl-25-phenyl ivermectin B1 aglycone;
23-nor-23-sulfinyl-24-desmethyl-25-des(2-butyl)-13-deoxy-13-fluoro-25-(4-fluoro)phenyl ivermectin B1;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-13-O-methoxyethoxymethyl-25-isopropyl ivermectin B1 aglycone;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-13-deoxy-13-chloro-25-tert-butyl ivermectin B1 aglycone;
23-nor-23-thia-24-desmethyl-25-des(2-butyl)-13-deoxy-25-cyclohexyl ivermectin B1 aglycone;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-4"-deoxy-4"-epi-(2-acetylaminoethyl)thio-25-sec-butyl ivermectin B1;
23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-4"-deoxy-4"-epi-(2-acetylaminoethyl)sulfonyl-25-tert-butyl ivermectin B1.
The compounds of the instant invention are prepared in a series of reactions beginning with the natural product avermectins or derivatives thereof. The reaction sequence used to prepare the instant compounds is shown in Reaction Scheme 1. For clarity and simplicity, the Reaction Scheme shows only carbon atoms numbered 17 and higher. ##STR5##
The critical intermediate III is prepared in six steps from avermectin starting material I (for purposes of example shown as avermectin B 2 a) with the 6,6-spiroketal ring system and the appropriate substituents at the remainder of the molecule or with a substitution pattern from which the substituent groups at the remainder of the molecule can be prepared after the synthesis of the instant compounds.
Compound I, suitably protected at the hydroxy groups, is reacted with an oxidizing agent such as oxalyl chloride in DMSO in the presence of at least 2 equivalents of a base to react with the HCl liberated during the course of the reaction. The reaction is carried out initially in the cold at temperatures less than 0° C. and preferably less than -50° C. and is generally complete in from 1 to 10 hours affording the 23-keto compound.
In the next step the 23-keto compound is reacted with an alkali metal bis(trimethylsilyl)amide to form the enol ether with a 22,23-double bond. The reaction is carried out in the cold at a temperature less than 0° C. and preferably less than -50° C. under an inert atmosphere in a non-reactive solvent such as a hydrocarbon, preferably an alkane or other nonpolar solvents such as tetrahydrofuran that will remain liquid at reaction temperatures. Generally mixtures of C 6 to C 9 alkanes, preferably hexanes, are used. The reaction is generally complete in from 1 to 10 hours. The choice of the base in this reaction is very important since it is well known that strong bases readily epimerize the 2-position of the avermectin molecule and rearrange the 3,4-double bond to give analogs of low biological potency. It was found that from a selection of numerous bases, an alkali metal bis(trimethylsilyl)amide is capable of forming the desired silyl enol ether without any further side reactions.
In the next step the 22,23-double bond is epoxidized with a mild oxidizing agent, preferably a peroxy acid such as meta-chloroperbenzoic acid. The reaction is carried out in an inert solvent such as a chlorinated hydrocarbon such as chloroform or methylene chloride and the like at a temperature of from 0° to 50° C. and is generally complete in about 10 minutes to 2 hours.
In the final step of the reaction of compound I to prepare compound II the 22,23-epoxide is treated with acidic methanol to hydrolize the epoxide and form compound II. The reaction is carried out at about room temperature and is generally complete in from 5 minutes to 2 hours.
In the foregoing series of reactions the intermediates may be isolated and purified, however it has not been found necessary to do so and if desired, the reactions may be carried out in a single reaction vessel, only isolating compound II at the conclusion of the series of four reaction steps.
Compound II is then cleaved to form the critical intermediate III. Compound II is treated with lead tetraacetate which cleaves the 22,23-bond affording critical intermediate III.
Compound III may be transketallized in a protic solvent, preferably methanol or isopropyl alcohol, using an organic acid such as pyridinium p-toluenesulfonate. In methanol, transketallization of III replaces the large side chain containing atoms 23-25 with a smaller methoxy group, thereby forming methoxy-aldehyde IV. The aldehyde function of IV may be selectively reduced with hydride reagents to produce an intermediate alcohol which is converted into the trifluoromethanesulfonate Va. The aldehyde function of aldehyde-ester III is converted into an alcohol under identical conditions and subsequently sulfonylated to form trifluoromethanesulfonate Vb. Triflates Va and Vb differ only in the group R (methoxy for the former while the latter contains the original side chain). The reduction of the aldehyde group of III or IV was best accomplished using sodium borohydride in methanol at 0° C. Other reducing reagents such as LiAlH 4 , LiBH 4 , diisobutylaluminum hydride and the like in aprotic solvents such as THF or ether at low temperature also were satisfactory. Sulfonylation reactions were best performed using amine bases such as pyridine, 4-dimethylaminopyridine or diisopropylethylamine in inert chlorinated solvents, preferably methylene chloride or chloroform at 0° C.
Treatment of either Va or Vb with an appropriately substituted sulfur nucleophile in a polar aprotic solvent in the presence of base yields sulfide VI. The displacement reaction was facilitated by the addition of 18-crown-6, generally resulting in shorter reaction times. Alcohol VI was cyclized in an inert chlorinated solvent, preferably methylene chloride using a mixture of pyridinium p-toluenesulfonate and p-toluenesulfonic acid at room temperature to formation the new 23-nor-23-thia avermectin derivatives VII. Cyclization of VI to VII also could be run successfully in methanol using p-toluensulfonic acid, however these conditions entailed heating the reaction to 40° C.
Sulfide VII was oxidized in inert solvents, such as methylene chloride or chloroform, to form sulfinyl analogs VIII and sulfonyl analogs IX. The oxidant of choice was meta-perbenzoic acid. The oxidation of sulfide VII could also be performed using oxidants such as sodium metaperiodate in methanol:water (1:1) or periodic acid in methylene chloride or chloroform. The oxidations could be run to generate the sulfoxides or sulfones selectively or produce mixtures of both if so desired.
Additional strategies for the preparation of 23-nor-23-thia-modified avermectins VII were developed. Triflate Va or Vb could be treated with potassium thioacetate in dimethylformamide at room temperature to yield the corresponding acetylthio derivative. The acetyl function could be removed using hydride nucleophiles in ethereal solvents, such as ether or THF, to generate thiol XII. Appropriate reducing agents include, but are not restricted to LiAlH 4 , LiBH 4 and diisobutylaluminum hydride. Reaction of thiol XII with an appropriate alpha-halo ketone allowed for selective formation of XIII. The ketone of compound XIII may be reduced with a variety of hydride sources to form either racemic or optically pure VI. These hydride sources include, but are not restricted to, NaBH 4 , LiAlH 4 , LiBH 4 , diisobutylaluminum hydride and oxazaborolidines. As before, alcohol VI may be cyclized under acidic conditions to generate sulfide VII.
An alternative method for the production of sulfide VII is disclosed as follows. Alcohol VI, where R 1 =R 2 =H, may be oxidized to its corresponding aldehyde (X). Preferred oxidants include the Dess-Martin periodinane, pyridinium dichromate, pyridinium chlorochromate and methyl sulfoxide/oxalyl chloride. Aldehyde X reacts readily with aromatic and aliphatic Grignard reagents (RMgBr) or lithium reagents (RLi) to produce VI. As before, alcohol VI may be cyclized under acidic conditions to generate sulfide VII.
Deprotection to remove the silyl protecting groups of sulfides VII is best accomplished using HF.pyridine in THF.
Treatment of compounds VII, VIII or IX with 1% sulfuric acid in methanol at room temperature for twelve hours allows for the preparation of the aglycones in deprotected form. If this reaction is run for four hours in isopropanol using 1% sulfuric acid, formation of the monosaccharides occurs.
Deprotection is best achieved using HF.pyridine in THF at room temperature for 12-48 hours. Deprotection of Va/b to yield VIIa/b under the identical conditions also proceeds readily.
Separation of stereoisomers, if present, is possible while at the VII and deprotected stages. The isomers may be separated, if desired, by thin layer preparative chromatography, flash chromatography or high pressure liquid chromatography (normal or reverse phase). Isomer separation at these various stages is dictated primarily by ease of separation at any given point.
The foregoing series of reactions is carried out using protecting groups on the reactive functions, such as hydroxy groups, on the avermectin molecule. Following the completion of the reaction sequence, the protecting groups may be removed to afford the unprotected final product. The isomers can be readily separated from each other prior to the removal of the protecting groups using chromatographic techniques, such as column chromatography. If the protecting groups are removed, the separation of the isomer is still readily accomplished chromatographically using thin layer or preparative layer chromatography or reverse phase high pressure liquid chromatography. The mixtures of stereoisomers as well as the isolated stereoisomers have been found to have substantial activity as antiparastic or insecticidal products.
Some additional substituents can be prepared on the instant compound using techniques known to those skilled in the art, such as the introduction of alkylthio or substituted alkylthio substitutents at the 4'- and 4"-positions and the oxidized derivatives thereof. The substituents can be synthesized either prior to the preparation of the 23-nor-23-thia ring system or after the 23-nor-23-thia ring system is prepared. However, to avoid undesired side-reactions, in particular where the alkylthio group contains reactive substituents, it is often preferred to prepare the 4'- or 4"-alkylthio substituent after the reactions for the preparation of the 23-nor-23-thia ring system have been completed.
The preparation of the 4'- and 4"-alkylthio compounds of this invention is best accomplished when the avermectin starting materials are protected at the 5-hydroxy position to avoid substitution at this position. With this position protected, the reactions may be carried out at the 4"- or 4'-positions without affecting the remainder of the molecule. The 5-hydroxy group is protected by a tert.-butyldimethylsilyl group before displacement at the 4"- or 4'-hydroxyl group has occurred. The 7-hydroxy group is very unreactive and need not be protected.
The preparation of the 4'- and 4"-alkylthio compounds requires that the avermectin starting materials are converted into derivatives with good leaving groups at the 4"- or 4'-position, preferably halo- or alkyl-substituted sulfonyl groups, more preferably trifluoromethanesulfonyl- or iodo-groups. Subsequently, these leaving groups are displaced by sulfur-containing nucleophiles to obtain the desired 4"-deoxy-4"-alkyl-thio avermectin derivatives (which also may be modified further).
The 4"- or 4'-alkyl substituted sulfonyl intermediate is prepared from the 5-position protected avermectin using the appropriate sulfonic anhydride or the appropriate sulfonyl chloride in an inert solvent such as a chlorinated hydrocarbon, tetrahydrofuran (THF), or ether, preferably methylene chloride, in the presence of base at -15° to 10° C. over a period of 15 minutes to 1 hour. The 4"- or 4'-alkyl substituted sulfonyl compound may be isolated using techniques known to those skilled in the art. Then the 4"- or 4'-sulfonylavermectin is substituted at the 4"- or 4'-position by sulfur-containing nucleophiles. The reaction is carried out at or near at room temperature in an inert solvent such as dimethylformamide (DMF), dimethylsulfoxide (DMSO), THF, chlorinated hydrocarbons, or ether, preferably DMF, with the desired thiol nucleophile, either the metallic thiol or a thiol with a base such as potassium carbonate at 0° to 25° C. over a period of 1 to 4 hours. It has been found useful to include in the reaction mixture a small quantity of crown ethers such as 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane). The presence of the crown ether facilitates the reaction and generally significantly reduces the duration of the reaction. The products are isolated using known techniques.
There are two possible epimers at the 4"- or 4'-position; one with the stereochemistry exactly as in the natural avermectins with an equatorial (or α) substituent and one with the axial (or β) configuration. The latter is called 4"- or 4'-epi. The reaction with strong nucleophiles results predominantly in the product with the inverted configuration. The reaction with hard nucleophiles usually gives both compounds, which are separable, but since both possess high biological activities, they need not be separated. Both epimers are considered part of this invention, either separate or in a mixture.
Nucleophilic substitution of the leaving group can be also accomplished by iodine, by adding a halogen salt to a stirred solution of the avermectin substituted with a good leaving group at the 4"-position in DMF, DMSO, THF or a chlorinated hydrocarbon and allowing the reaction to stir at room temperature from 1 to 6 hours. The product is isolated using known techniques. The 4"-halogen atom can, in turn, be displaced by other nucleophiles, including other sulfur-containing nucleophiles.
In addition, the sulfur-containing 4"-substituent can be further modified. Oxidation of the 4"-sulfur in an unreactive solvent with an oxidizing agent such as m-chloroperbenzoic acid at -15° to 25° C. for a period of 30 minutes to 2 hours gives the sulfoxide and the sulfone. Both enantiomers of the sulfoxide are obtained.
The sulfur-containing 4'- and 4"-groups can be oxidized to the corresponding sulfinyl and sulfonyl groups in a solvent such as a chlorinated hydrocarbon, THF, ether, or lower alcohol, preferably methylene chloride. An oxidizing agent such as a peracid, preferably m-chloroperbenzoic acid, is added to a solution of the 4"- or 4'-substituted avermectin. By varying the temperature (from -30° C. to room temperature) and the number of equivalents of oxidizing agent, the relative yields of the sulfoxide and sulfone can be controlled. The products are separated and isolated using techniques known to those skilled in the art.
Further modifications of the side chain can be accomplished when a thio-alcohol is used as the nucleophile. The hydroxyl group of the alcohol on the sulfur-containing side chain can undergo any of the reactions and chemistry that is possible at the 4"- or 4'-hydroxy group, including, but not limited to, those described herein.
Following the desired substitution and modification at the 4"-position, the 5-hydroxy group is deprotected and, if desired, modifications of the molecule at the 5-position can occur.
The foregoing reactions carried out at the 4"-position of the avermectin can be carried out at the 4'-position of the avermectin monosacchoride to affect the correspondingly substituted monosacchoride derivatives.
The preparation of additional derivatives of the various reactive substituents can also be carried out using procedures well known to those skilled in the art. See for example U.S. Pat. No. 4,906,619 to Eskola et al, for the preparation of various alkylated avermectins; U.S. Pat. No. 4,427,663 to Mrozik for the preparation of various 4'- or 4"- keto or amino derivatives; U.S. Pat. No. 4,201,861 to Mrozik et al, for the preparation of various, acylated avermectins; U.S. Pat. Nos. Re. 32006 and Re. 32034 to Chabala et al for the preparation of various 13-substituted and 13-unsubstituted avermectins; U.S. Pat. No. 4,200,981 to Fisher et al for the preparation of various 5-alkylated compounds; and U.S. Pat. No. 4,895,837 to Mrozik for a discussion of various procedures for the protection of avermectin compounds.
The instant compounds are potent endo-and ecto-antiparasitic agents against parasites particularly helminths, ectoparasites, insects, and acarides, infecting man, animals and plants, thus having utility in human and animal health, agriculture and pest control in household and commercial areas.
The disease or group of diseases described generally as helminthiasis is due to infection of an animal host with parasitic worms known as helminths. Helminthiasis is a prevalent and serious economic problem in domesticated animals such as swine, sheep, horses, cattle, goats, dogs, cats, fish, buffalo, camels, llamas, reindeer, laboratory animals, furbearing animals, zoo animals and exotic species and poultry. Among the helminths, the group of worms described as nematodes causes widespread and often times serious infection in various species of animals. The most common genera of nematodes infecting the animals referred to above are Haemonchus, Trichostrongylus, Ostertagia, Nematodirus, Cooperia, Ascaris, Bunostomum, Oesophagostomum, Chabertia, Trichuris, Strongylus, Trichonema, Dictyocaulus, Capillaria, Habronema, Druschia, Heterakis, Toxocara, Ascaridia, Oxyuris, Ancylostoma, Uncinaria, Toxascaris and Parascaris. Certain of these, such as Nematodirus, Cooperia, and Oesophagostomum attack primarily the intestinal tract while others, such as Haemonchus and Ostertagia, are more prevalent in the stomach while still others such as Dictyocaulus are found in the lungs. Still other parasites may be located in other tissues and organs of the body such as the heart and blood vessels, subcutaneous and lymphatic tissue and the like. The parasitic infections known as helminthiases lead to anemia, malnutrition, weakness, weight loss, severe damage to the walls of the intestinal tract and other tissues and organs and, if left untreated, may result in death of the infected host. The compounds of this invention have unexpectedly high activity against these parasites, and in addition are also active against Dirofilaria in dogs and cats, Nematospiroides, Syphacia, Aspiculuris in rodents, arthropod ectoparasites of animals and birds such as ticks, mites, lice, fleas, blowflies, in sheep Lucilia sp., biting insects and such migrating diperous larvae as Hypoderma sp. cattle, Gastrophilus in horses, and Cuterebra sp. in rodents and nuisance flies including blood feeding flies and filth flies.
The instant compounds are also useful against parasites which infect humans. The most common genera of parasites of the gastro-intestinal tract of man are Ancylostoma, Necator, Ascaris, Strongyloides, Trichinella, Capillaria, Trichuris, and Enterobius. Other medically important genera of parasites which are found in the blood or other tissues and organs outside the gastrointestinal tract are the filiarial worms such as Wuchereria, Brugia, Onchocerca and Loa, Dracunuculus and extra intestinal stages of the intestinal worms Strongyloides and Trichinella. The compounds are also of value against arthropods parasitizing man, biting insects and other dipterous pests causing annoyance to man.
The compounds are also active against household pests such as the cockroach, Blatella sp., clothes moth, Tineola sp., carpet beetle, Attagenus sp., the housefly Musca domestica as well as fleas, house dust mites, termites and ants.
The compounds are also useful against insect pests of stored grains such as Tribolium sp., Tenebrio sp. and of agricultural plants such as aphids, (Acyrthiosiphon sp.); against migratory orthopterans such as locusts and immature stages of insects living on plant tissue. The compounds are useful as a nematocide for the control of soil nematodes and plant parasites such as Meloidogyne sp. which may be of importance in agriculture. The compounds are also highly useful in treating acerage infested with fire ant nests. The compounds are scattered above the infested area in low levels in bait formulations which are brought back to the nest. In addition to a direct-but-slow onset toxic effect on the fire ants, the compound has a long-term effect on the nest by sterilizing the queen which effectively destroys the nest.
The compounds of this invention may be administered in formulations wherein the active compound is intimately admixed with one or more inert ingredients and optionally including one or more additional active ingredients. The compounds may be used in any composition known to those skilled in the art for administration to humans and animals, for application to plants and for premise and area application to control household pests in either a residential or commercial setting. For application to humans and animals to control internal and external parasites, oral formulations, in solid or liquid or parenteral liquid, implant or depot injection forms may be used. For topical application dip, spray, powder, dust, pour-on, spot-on, jetting fluid, shampoos, collar, tag or harness, may be used. For agricultural premise or area application, liquid spray, powders, dust, or bait forms may be used. In addition "feed-through" forms may be used to control nuisance flies that feed or breed in animal waste. The compounds are formulated, such as by encapsulation, to lease a residue of active agent in the animal waste which controls filth flies or other arthropod pests.
These compounds may be administered orally in a unit dosage form such as a capsule, bolus or tablet, or as a liquid drench where used as an anthelmintic in mammals. The drench is normally a solution, suspension or dispersion of the active ingredient usually in water together with a suspending agent such as bentonite and a wetting agent or like excipient. Generally, the drenches also contain an antifoaming agent. Drench formulations generally contain from about 0.001 to 0.5% by weight of the active compound. Preferred drench formulations may contain from 0.01 to 0.1% by weight. The capsules and boluses comprise the active ingredient admixed with a carrier vehicle such as starch, talc, magnesium stearate, or di-calcium phosphate.
Where it is desired to administer the instant compounds in a dry, solid unit dosage form, capsules, boluses or tablets containing the desired amount of active compound usually are employed. These dosage forms are prepared by intimately and uniformly mixing the active ingredient with suitable finely divided diluents, fillers, disintegrating agents, and/or binders such as starch, lactose, talc, magnesium stearate, vegetable gums and the like. Such unit dosage formulations may be varied widely with respect to their total weight and content of the antiparasitic agent depending upon factors such as the type of host animal to be treated, the severity and type of infection and the weight of the host.
When the active compound is to be administered via an animal feedstuff, it is intimately dispersed in the feed or used as a top dressing or in the form of pellets or liquid which may then be added to the finished feed or optionally fed separately. Alternatively, feed based individual dosage forms may be used such as a chewable treat. Alternatively, the antiparasitic compounds of this invention may be administered to animals parenterally, for example, by intraruminal, intramuscular, intravascular, intratracheal, or subcutaneous injection in which the active ingredient is dissolved or dispersed in a liquid carrier vehicle. For parenteral administration, the active material is suitably admixed with an acceptable vehicle, preferably of the vegetable oil variety such as peanut oil, cotton seed oil and the like. Other parenteral vehicles such as organic preparation using solketal, glycerol formal, propylene glycol, and aqueous parenteral formulations are also used. The active compound or compounds are dissolved or suspended in the parenteral formulation for administration; such formulations generally contain from 0.0005 to 5% by weight of the active compound.
Although the antiparasitic agents of this invention find their primary use in the treatment and/or prevention of helminthiasis, they are also useful in the prevention and treatment of diseases caused by other parasites, for example, arthropod parasites such as ticks, lice, fleas, mites and other biting arthropods in domesticated animals and poultry. They are also effective in treatment of parasitic diseases that occur in other animals including humans. The optimum amount to be employed for best results will, of course, depend upon the particular compound employed, the species of animal to be treated and the type and severity of parasitic infection or infestation. Generally good results are obtained with our novel compounds by the oral administration of from about 0.001 to 10 mg per kg of animal body weight, such total dose being given at one time or in divided doses over a relatively short period of time such as 1-5 days. With the preferred compounds of the invention, excellent control of such parasites is obtained in animals by administering from about 0.025 to 0.5 mg per kg of body weight in a single dose. Repeat treatments are given as required to combat re-infections and are dependent upon the species of parasite and the husbandry techniques being employed. The techniques for administering these materials to animals are known to those skilled in the veterinary field.
When the compounds described herein are administered as a component of the feed of the animals, or dissolved or suspended in the drinking water, compositions are provided in which the active compound or compounds are intimately dispersed in an inert carrier or diluent. By inert carrier is meant one that will not react with the antiparasitic agent and one that may be administered safely to animals. Preferably, a carrier for feed administration is one that is, or may be, an ingredient of the animal ration.
Suitable compositions include feed premixes or supplements in which the active ingredient is present in relatively large amounts and which are suitable for direct feeding to the animal or for addition to the feed either directly or after an intermediate dilution or blending step. Typical carriers or diluents suitable for such compositions include, for example, distillers' dried grains, corn meal, citrus meal, fermentation residues, ground oyster shells, wheat shorts, molasses solubles, corn cob meal, edible bean mill feed, soya grits, crushed limestone and the like. The active compounds are intimately dispersed throughout the carrier by methods such as grinding, stirring, milling or tumbling. Compositions containing from about 0.005 to 2.0% weight of the active compound are particularly suitable as feed premixes. Feed supplements, which are fed directly to the animal, contain from about 0.0002 to 0.3% by weight of the active compounds.
Such supplements are added to the animal feed in an amount to give the finished feed the concentration of active compound desired for the treatment and control of parasitic diseases. Although the desired concentration of active compound will vary depending upon the factors previously mentioned as well as upon the particular compound employed, the compounds of this invention are usually fed at concentrations of between 0.00001 to 0.002% in the feed in order to achieve the desired antiparasitic result.
In using the compounds of this invention, the individual compounds may be prepared and used in that form. Alternatively, mixtures of the individual compounds may be used, or other active compounds not related to the compounds of this invention.
The compounds of this invention are also useful in combatting agricultural pests that inflict damage upon crops while they are growing or while in storage. The compounds are applied using known techniques as sprays, dusts, emulsions and the like, to the growing or stored crops to effect protection from such agricultural pests.
The following examples are provided in order that this invention might be more fully understood; they are not to be construed as limitative of the invention.
EXAMPLE 1
4",5-Di-O-t-Butyldimethylsilyl-Avermectin B2a
To a solution of 58.2 g (65 mmol) of dried avermectin B2a in 400 mL of sieve-dried dimethylformamide and 30 mL of freshly distilled triethylamine was added a solution of 29.8 g (198 mmol, 3 equiv.) of t-butyldimethylsilyl chloride in 200 mL of dichloromethane. The mixture was stirred at room temperature 16 hours then poured into ice water and extracted with dichloromethane. The organic phases were combined and washed with water, brine, and dried over magnesium sulfate. Evaporation of the solvent afforded an oil which was purified by silica gel liquid chromatography using 20% ethyl acetate-hexanes to yield 34.2 g of 4",5-di-O-t-butyldimethylsilylavermectin B2a characterized by its NMR and mass spectra.
EXAMPLE 2
4",5-Di-O-t-Butyldimethylsilyl-23-oxo-Avermectin B2a
A 5-L 3-neck flask equipped with a thermometer, mechanical stirrer, and dropping funnel was charged with 400 mL of dichloromethane and 16 mL (0.185 mol) of oxalyl chloride. The solution was cooled to -70° C., under nitrogen while a solution of 25 mL (0.350 mol) of dimethylsulfoxide in 200 mL of dichloromethane was added dropwise over 30 minutes keeping the internal temperature below -65° C. The mixture was stirred at -70° C. for 1 hour. A solution of 114.75 g (0.103 mmol) of 4",5-di-O-t-butyldimethylsilyl-avermectin B2a in 900 mL of dichloromethane was then added dropwise over 45 minutes keeping the temperature of the mixture below -65° C. After an additional 2 hours at -70° C., 115 mL of triethylamine was added dropwise over 10 minutes again keeping the temperature below -65° C. The reaction was then stirred at approximately 10° C. for 1 hour before the solvent was removed in vacuo. The residue was taken up in 1.5 L of ether and washed with 500 mL of water. The aqueous layer was extracted with 500 mL of ether. The combined ether layers were washed sequentially with 2×1 L of water, 1 L of saturated sodium bicarbonate, and 1 L of brine, then dried over magnesium sulfate. The solvent was removed to afford 100 g of yellow foam purified by column chromatography (4 kg silica gel, eluted with 5-25% ethyl acetatehexane eluant). The product was obtained as a yellow foam (101 g, 88% yield). NMR (300 MHz, TMS) δ0.08 (d, J=6 Hz), 0.14 (s), 0.9 (s), 0.93 (s), 0.98 (m), 1.16 (d, J=7 Hz), 1.2 (d, J=Hz), 1.24 (d, J=7 Hz), 1.45 (s), 1.5 (m), 1.8 (s), 2.22 (m), 2.44 (m), 3.12 (t, J=9 Hz), 3.2 (t, J=9 Hz), 3.32 (s), 3.42 (s), 3.6 (m), 3.81 (d, J=6 Hz), 3.93 (s), 3.98 (sh s), 4.44 (d, J=6 Hz), 4.62 (dq, J=2,14 Hz), 4.74 (d, J=3 Hz), 4.93 (t, J=7 Hz), 5.3 (m), 5.7 (m), 5.8 (m); mass spec: FAB 1123 (M+Li).
EXAMPLE 3
4",5-Di-O-t-Butyldimethylsilyl-7-O-trimethylsilyl-23-O-trimethylsilyloxy-Avermectin B1a
To a solution of 101 mg (0.09 mmol) of 4",5-di-O-t-butyldimethylsilyl-23-oxo-avermectin B2a in 2 mL of distilled tetrahydrofuran at -78° C. was added 0.400 mL of a 1.0M solution of lithium bis(trimethylsilyl)amide in a mixture of hexanes. The mixture was stirred at -78° C., under argon, for 1 hour before 0.20 mL of the supernatant of a centrifuged 1:3 mixture of triethylamine and trimethylchlorosilane was added dropwise via a syringe. After another 30 minutes, 2 ml of a saturated aqueous sodium bicarbonate solution was added and the mixture was allowed to warm to room temperature. The reaction mixture was then partitioned between water and ether and the ethereal extracts were combined and dried over magnesium sulfate. Filtration and evaporation of the ther afforded 120 mg of 4",5-di-O-t-butyldimethylsilyl-7-O-trimethylsilyl-23-O-trimethylsilyloxy-avermectin B1a characterized by its NMR δ0.08 (d, J=6 Hz), 0.12 (s), 0.18 (s), 0.88 (s), 0.92 (s), 1.18 (d, J=8 Hz), 1.23 (d, J=8 Hz), 1.26 (d, J=8 Hz), 1.5 (s), 1.51 (m), 1.78 (s), 2.3 (m), 2.58 (m), 3.12 (t, J=9 Hz), 3.22 (t, J=9 Hz), 3.25 (s), 3.32 (s), 3.4 (s), 3.8 (d, J=6 Hz), 3.82 (m), 3.98 (s), 4.39 (d, J=4 Hz), 4.6 (q, J=16 Hz), 4.68 (sh d, J=2 Hz, C22H), 4.8 (d, J=3 Hz), 4.9 (m), 5.1 (m), 5.25 (d, J=3 Hz), 5.45 (s), 5.7 (m).
EXAMPLE 4
4",5-Di-O-t-Butyldimethylsilyl-7-O-trimethylsilyl-22-hydroxy-23-oxo-Avermectin B2a
To a solution of 135 mg (0.107 mmol) of 4",5-Di-O-t-butyldimethylsilyl-7-O-trimethylsilyl-23-O-trimethylsilyloxy-Avermectin B1a in 2 mL of dichloromethane was added a solution of 21 mg (0.12 mmol) of m-chloro-perbenzoic acid in 1 mL of dichloromethane in one portion. After 20 minutes at 20° C., 0.2 mL of dimethylsulfide was added. The mixture was stirred another 30 minutes before the addition of aqueous sodium bicarbonate and extraction with ethyl acetate. The combined organic fractions were dried, filtered, and evaporated to afford 150 mg of solid. This product mixture was separated by preparative thin layer chromatography (20% ethyl actate-hexane) to afford 40 mg of 4",5-Di-O-t-butyldimethylsilyl-7-O-trimethylsilyl-22-hydroxy-23-oxo-Avermectin B2a. NMR δ0.08 (d, J=6 Hz), 0.14 (s), 0.88 (s), 0.92 (s), 0.96 (d, J=6 Hz), 0.98 (d, J=6 Hz), 1.16 (d, J=7 Hz), 1.20 (d, J=6 Hz), 1.23 (d, J=6 Hz), 1.43 (s), 1.50 (s), 1.52 (m), 1.78 (s), 2.24 (m), 2.4 (dd, J=6,12 Hz), 2.58 (m), 3.12 (t, J=9 Hz), 3.22 (t, J=9 Hz), 3.3 (s), 3.32 (s), 3.4 (s), 3.62 (m), 3.82 (m), 3.82 (d, J=6 Hz), 3.92 (d, J=7 Hz), 3.97 (s), 4.38 (d, J=3 Hz), 4.6 (q, J=15 Hz), 4.77 (d, J=3 Hz), 4.83 (m), 5.05 (br d, J=7 Hz), 5.25 (d, J=3 Hz), 5.5 (s), 5.7 (m); mass spec. FAB 1212 (M+Li+H).
EXAMPLE 5
Preparation of aldehyde-acid
To a solution of 600 mg (0.5 mmol) of 4",5-Di-O-t-butyldimethylsilyl-7-O-trimethysilyl-22-hydroxy-23-oxo-Avermectin B2a in 6 mL of benzene in an aluminum foil-covered glass vial was added 400 mg (0.9 mmol) of lead tetraacetate in one portion. After 30 minutes at 20° C., the solution was poured into a separatory funnel containing 12 mL of water and 600 mg of sodium sulfite. The mixture was then shaken and extracted with ethyl acetate. The combined extracts were dried (MgSO 4 ), filtered, and evaporated to afford 600 mg of solid. Flash chromatography through a column of silica gel eluting with 2:1 hexane:ethyl acetate, then acetone afforded 250 mg of starting material and 230 mg of aldehyde-acid. NMR δ0.08 (d, J=6 Hz), 0.13 (s), 0.89 (s), 0.92 (s), 1.15 (d, J=6 Hz), 1.18 (d, J=6 Hz), 1.20 (d, J=6 Hz), 1.26 (d, J=6 Hz), 1.5 (s), 1.53 (m), 1.78 (s), 2.3 (m), 2.78 (br s), 3.13 (t, J=9 Hz), 3.23 (t, J=9 Hz), 3.23 (s), 3.32 (s), 3.36 (m), 3.42 (br s), 3.68 (m), 3.81 (m), 3.82 (d, J=6 Hz), 3.98 (s), 4.38 (s), 4.6 (q, J=15 Hz), 4.79 (d, J=2 Hz), 4.86 (br s), 5.12 (br s), 5.3 (s), 5.44 (s), 5.7 (m).
EXAMPLE 6
Transketalization of Aldehyde-acid to Methoxy Aldehyde (III) and 2R,3R,4S-2,4-dimethyl-3-hydroxyhexanoic acid
To a solution of 8 g of pyridinium tosylate in 80 mL of dry methanol was added 16.3 g of the aldehyde-acid from Example 5. The mixture was stirred at 20° C. for 1.5 hours before 4 mL of triethylamine was added. The mixture was then transferred to a separatory funnel containing 4.4 g of sodium bicarbonate and 500 mL of water. The mixture was extracted with ether and the aqeuous layer was then acidified with 2N HCl and extracted with ethyl acetate to recover 1.6 g of 2R,3R,4S-2,4-dimethyl-3-hydroxyhexanoic acid as an amber oil. The ether extracts were combined and dried over magnesium sulfate. Filtration and evaporation of the solvent afforded 15.5 g of solid as a 1:1:1 mixture of methoxy ketals and the aldehyde-acid in addition to some minor products with a slower Rf than the methoxy ketal but faster than the aldehyde-acid. The mixture was separated by flash column chromatography on 550 g of silica gel eluted with 3:1 and then 2:1 hexane: ethyl acetate to yield 5.1 g and 4.0 g and 3.9 g of the methoxy ketals each characterized by NMR and mass spectroscopy. NMR of methoxy-ketal A: δ0.08 (d, J=6 Hz), 0.12 (s), 0.14 (s), 0.88 (s), 0.92 (s), 1.17 (d, J=7 Hz), 1.21 (d, J=7 Hz), 1.25 (d, J=7 Hz), 1.5 (m), 1.51 (s), 1.78 (s), 2.3 (m), 2.5 (m), 3.13 (t, J=9 Hz), 3.22 (t, J=9 Hz), 3.28 (sh d, J=2 Hz), 3.32 (s), 3.38 (s), 3.44 (s), 3.65 (m), 3.82 (d, J=6 Hz), 3.98 (s), 4.38 (d, J=3 Hz), 4.6 (dq, J=2,15 Hz), 4.7 (m), 4.78 (d, J= 3 Hz), 5.12 (d, J=11 hz), 5.30 (d, J=3 Hz), 5.48 (s), 5.57 (m), 5.75 (dd, J=11,16 Hz), 9.37 (s). NMR of methoxy ketal B: δ0.08 (d, J=6 hz), 0.13 (s), 0.88 (s), 0.90 (m), 0.92 (s), 1.18 (d, J=7 Hz), 1.21 (d, J=7 Ha), 1.26 (d, J=6 Hz), 1.42 (s), 1.5 (m), 1.52 (s), 1.6 (m), 1.78 (s), 1.90 (d, J=12 Hz), 2.35 (m), 2.58 (tt, J=6,2 Hz), 3.13 (t, J=9 Hz), 3.22 (t, J=9 Hz), 3.25 (s), 3.28 (s), 3.32 (s), 3.43 (s), 3.66 (m), 3.82 (d, J=6 Hz), 3.84 (m), 3.99 (s), 4.38 (d, J=3 Hz), 4.60 (dq, J=2,15 Hz), 4.80 (d, J=3 Hz), 4.90 (m), 5.15 (dd, J=5,12 Hz), 5.29 (d, J=3 Hz), 5.46 (s), 5.57 (m, J=9 Hz), 5.63 (d, J=12 Hz), 5.76 (dd, J=12,15 Hz), 9.39 (s). The stereochemical assignment at C21 for the methoxy ketal isomers A and B was based on the nonreversible conversion of A to B when each pure isomer was resubjected to acidic methanol. Isomer B being the thermodynamically stable isomer has been assigned the axial methoxy/equitorial formyl configuration. The chiral acid was esterified with excess diazomethane and purified by flash chromatography with 15% ethyl acetate-hexane to yield 1 g of methyl ester [α] D =-9.5°, c=8.9 g/dL dichloromethane, characterized by its NMR spectrum.
EXAMPLE 7
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23,24,25-nor-22-trifluoromethanesulfonate-Avermectin B 1 (Va)
520 mg Methoxy-aldehyde IV (509 μmol) was dissolved in 10 mL methanol at 0° C. to which was added 85 mg NaBH 4 (2.5 mmol). After 10 min at 0° C., 0.5 mL acetone was added to the reaction and the solution was poured into 30 mL saturated NH 4 Cl, extracted with methylene chloride and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure alcohol (390 mg, 75%) was obtained by flash chromatography on silica gel using 6:4 hexanes:EtOAc as eluant. This alcohol was dissolved in 3 mL methylene chloride at 0° C. to which was added 35 μL diisopropylethyl amine (200 μmol), 25 mg 4-dimethylaminopyridine (200 μmol) and 25 mL (CF 3 SO 2 ) 2 O (150 μmol). After 15 min at 0° C., the reaction was filtered through a 1.5 inch plug of silica gel using 6:4 hexanes:EtOAc as eluant to yield 375 mg Va (85%). This material was a pale yellow solid following lyophilization from benzene (hydroscopic!).
EXAMPLE 8
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-(methyl 2R,3R, 4S-2,4-dimethylhexanoate)-21,25-seco-24-desmethyl-25-des(2-butyl)-22-trifluoromethanesulfonate-Avermectin B 1 (Vb)
2.0 g Aldehyde-ester III (1.62 mmol) was dissolved in 20 mL methanol at 0° C. to which was added 65 mg NaBH 4 (1.71 mmol). After 15 min, the solution was poured into 40 mL saturated NH 4 Cl, extracted with EtOAc, washed with brine and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. The resultant alcohol was purified by flash chromatography on silica gel to yield 1.56 g alcohol (78%). 832 mg of this alcohol (674 mmol) was dissolved in 5 mL methylene chloride at -30° C. to which was added 247 mg 4-dimethylaminopyridine (2.02 mmol), 261 mg diisopropylethyl amine (2.02 mmol) and 285 mg (CF 3 SO 2 ) 2 O (1.01 mmol). The solution was warmed to 0° C. and stirred for 10 min. The solution was filtered directly through a 1.5 inch plug of silica gel using 1:3 EtOAc:hexanes as eluant. Pure Vb (801 mg, 87%) was obtained as a pale yellow solid after lyophilization from benzene (hydroscopic!).
EXAMPLE 9
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-hydroxy-23-this-invermectin B1 (VIa)
190 mg Triflate Va (164 μmol) was dissolved in 3 mL dimethylformamide at RT. To this was added 200 μL 2-mercaptoethanol, 100 mg K 2 CO 3 , and 10 mg 18-crown-6. The solution was stirred at RT for 1 hr, poured into 40 mL 1:1 water:saturated NaHCO 3 , extracted with methylene chloride and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure VIa (145 mg, 82%) was obtained by flash chromatography on silica gel using 1:1 hexanes:EtOAc as eluant.
EXAMPLE 10
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-(methyl 2R,3R,4S-2,4-dimethylhexanoate)-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-23-thia-25-hydroxy-ivermectin B1 (VIb)
800 mg Triflate Vb (585 μmol) was dissolved at RT in 5 mL dimethylformamide to which was added 20 mg 18-crown-6, 718 mg mercaptoethanol and 800 mg K 2 CO 3 . After 30 min at RT, the solution was poured into 20 mL saturated NaHCO 3 , extracted with EtOAc and dried (MgSO 4 ). The solution was filtered and concentrated to approximately 5 mL then filtered through a 1.5 inch plug of silica gel using 1:1 hexanes:EtOAc as eluant. The solvents were removed under reduced pressure and pure VIb (646 mg, 85%) was obtained after flash chromatography on silica gel using 1:3 to 2:3 EtOAc:hexanes gradient elution.
EXAMPLE 11
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsily-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-phenyl-25-hydroxy-23-thia-ivermectin B1 (VIc)
105 mg Aldehyde XI (91 μmol) was placed in 3 mL THF at 0° C. to which was added 61 μL PhMgBr (3M in THF, 182 μmol). After 30 min at 0° C., the solution was poured into 10 mL saturated NH 4 Cl, extracted with EtOAc and dried (MgSO 4 ). Pure VIc (61 mg, 54%) was obtained by flash chromatography on silica gel with 2:1 hexanes:EtOAc as eluant.
EXAMPLE 12
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-25-hydroxy-23-thia-ivermectin B1 (VId)
200 mg Aldehyde XI (173 μmol) was placed in 4 mL THF at 0° C. to which was added 260 μL i-PrMgBr (2M in THF, 519 μmol). After 30 min at 0° C., the solution was poured into 15 mL saturated NH 4 Cl, extracted with EtOAc and dried (MgSO 4 ). Pure VId (195 mg, 93%) was obtained by flash chromatography on silica gel with 2:1 hexanes:EtOAc as eluant.
EXAMPLE 13
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-cyclohexyl-25-hydroxy-23-thia-ivermectin B1 (VIe)
200 mg Aldehyde XI (173 μmol) was placed in 4 mL THF at 0° C. to which was added 260 μL c-C 6 H 11 MgBr (2M in THF, 519 μmol). After 30 min at 0° C., the solution was poured into 15 mL saturated NH 4 Cl, extracted with EtOAc and dried (MgSO 4 ). Pure VIe (165 mg, 77%) was obtained by flash chromatography on silica gel with 2:1 hexanes:EtOAc as eluant.
EXAMPLE 14
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-(methyl 2R,3R,4S-2,4-dimethylhexanoate)-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-tert-butyl-25-hydroxy-23-thia-ivermectin B1 (VIf)
127 mg Ketone XIIIc (94 μmol) was dissolved in 5 mL methanol at 0° C. to which was added 40 mg NaBH 4 . After 30 min at 0° C., the reaction was quenched with acetone, diluted with 2 mL saturated NH 4 Cl, extracted with EtOAc and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure VIf (120 mg, 94%) was obtained after flash chromatography on silica gel using 2:2:7 tert-BuOMe:CH 2 Cl 2 :hexanes.
EXAMPLE 15
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-24-desmethyl-25-des(2-butyl)-23-nor-23-thia-ivermectin B1 (VIIa)
120 mg Alcohol VIa (111 μmol) was placed in 5 mL methylene chloride at RT to which was added 5 mg p-toluenesulfonic acid. After 15 min, the reaction was poured into 10 mL saturated NaHCO 3 , extracted with methylene chloride and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure VIIa (101 mg, 86%) was obtained as a colorless glass by flash chromatography on silica gel using 2:1 hexanes:EtOAc as eluant.
EXAMPLE 16
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-24-desmethyl-25-des(2-butyl)-23-nor-25-phenyl-23-thia-ivermectin B1 (VIIb)
70 mg Alcohol VIc (60 μmol) was placed in 2.5 mL methylene chloride at RT to which was added 8 mg pyridinium p-toluenesulfonic acid and 2 mg p-toluenesulfonic acid. After 30 min at RT, 200 μL triethyl amine was added, the solution concentrated under reduced pressure and purified with no further workup by flash chromatography on silica gel using 3:1 hexanes:EtOAc as eluant. Sulfide VIIb (52 mg, 76%) was obtained as a white powder.
EXAMPLE 17
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-24-desmethyl-25-des(2-butyl)-23-nor-25-R-phenyl-23-thia-ivermectin B1 (VIIc)
54 mg Ketone XIIIb (44 μmol) was dissolved in toluene at -30° C. to which was added 5 mg (R)-(+)-oxa-zaborolidine.BH 3 (1.7 μmol) followed by 200 μL BH 3 .SMe 2 (0.5M in THF). After 1 hr, the solution was brought to 0° C. After 40 min at 0° C., the reaction was quenched with 10 mL saturated NH 4 Cl, extracted with EtOAc and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. With no further purification, the resultant alcohol was dissolved in 2 mL methylene chloride to which was added 50 mg pyridinium p-toluenesulfonic acid and 5 mg p-toluenesulfonic acid. The reaction was quenched with 2 mL saturated NaHCO 3 , extracted with EtOAc and dried (MgSO 4 ). Pure VIIc (47 mg, 89%) was obtained as a white powder after flash chromatography on silica gel using 3:1 hexanes:EtOAc as eluant.
EXAMPLE 18
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-thia-ivermectin B1 (VIId)
195 mg Alcohol VId (162 μmol) was placed in 4 mL methylene chloride at Rt to which was added 10 mg pyridinium p-toluenesulfonic acid and 5 mg p-toluenesulfonic acid. After 15 min at RT, 300 μL triethyl amine was added and the solution purified with no further workup by flash chromatography on silica gel using 2:1 hexanes:EtOAc as eluant. Pure VIId (130 mg, 68%) was thus obtained as a white powder.
EXAMPLE 19
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-24-desmethyl-25-des(2-butyl)-23-nor-25-cyclohexyl-23-thia-ivermectin B1 (VIIe)
165 mg Alcohol VIe (133 μmol) was placed in 4 mL methylene chloride at RT to which was added 10 mg pyridinium p-toluenesulfonic acid and 5 mg p-toluenesulfonic acid. After 15 min at RT, 300 μL triethyl amine was added and the solution purified with no further workup by flash chromatography on silica gel using 2:1 hexanes:EtOAc as eluant. Pure VIIe (130 mg, 81%) was thus obtained as a white powder.
EXAMPLE 20
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-24-desmethyl-25-des(2-butyl)-23-nor-25-tert-butyl-23-thia-ivermectin B1 (VIIf)
120 mg Alcohol VIf (94 μmol) was placed in 2 mL methylene chloride at Rt to which was added 108 mg pyridinium p-toluenesulfonic acid and 7 mg p-toluenesulfonic acid. After 10 min at RT, 200 μL triethyl amine was added and the solution purified with no further workup by flash chromatography on silica gel using 3:1 hexanes:EtOAc as eluant. Pure VIIf (108 mg, 97%) was thus obtained as a white powder.
EXAMPLE 21
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-23-thia-ivermectin B1
101 mg Tris-silyl ether VIIa (96 μmol) was placed in 5 mL THF at RT to which was added 1 mL HF.pyridine solution (25 g HF.pyridine, 10 mL pyridine, 25 mL THF). After 48 hrs, the solution was poured into 40 mL 1:1 water:Et 2 O. The layers were separated and neutralized separately with saturated NaHCO 3 . The aqueous layers were pooled and extracted with Et 2 O. The organic layers were combined and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure deprotected 24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-23-thia-ivermectin B1 (55 mg, 70%) was obtained by flash chromatography on silica gel using 3:1 EtOAc:hexanes as eluant.
EXAMPLE 22
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-thia-ivermectin B1
60 mg Tris-silyl ether VIIc (53 μmol) was placed in 4 mL THF at RT to which was added 1 mL HF.pyridine solution (25 g HF.pyridine, 10 mL pyridine, 25 mL THF). After 48 hrs, the solution was poured into 40 mL 1:1 water:Et 2 O. The layers were separated and neutralized separately with saturated NaHCO 3 . The aqueous layers were pooled and extracted with Et 2 O. The organic layers were combined and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure deprotected 24-desmethyl-25-des(2-butyl)-23-nor-25-phenyl-23-thia-ivermectin B1 (55 mg, 70%) was obtained by flash chromatography on silica gel using 3:1 EtOAc:hexanes as eluant.
EXAMPLE 23
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-thia-ivermectin B1
130 mg Tris-silyl ether VIId (111 μmol) was placed in 4 mL THF at RT to which was added 1 mL HF.pyridine solution (25 g HF.pyridine, 10 mL pyridine, 25 mL THF). After 48 hrs, the solution was poured into 40 mL 1:1 water:Et 2 O. The layers were separated and neutralized separately with saturated NaHCO 3 . The aqueous layers were pooled and extracted with Et 2 O. The organic layers were combined and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure deprotected 24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-25-iso-propyl-23-thia-ivermectin B1 (91 mg, 94%) was obtained by flash chromatography on silica gel using 3:1 EtOAc:hexanes as eluant.
EXAMPLE 24
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-25-cyclohexyl-23-thia-ivermectin B1
144 mg Tris-silyl ether VIIe (119 μmol) was placed in 4 mL THF at RT to which was added 1 mL HF.pyridine solution (25 g HF.pyridine, 10 mL pyridine, 25 mL THF). After 48 hrs, the solution was poured into 40 mL 1:1 water:Et 2 O. The layers were separated and neutralized separately with saturated NaHCO 3 . The aqueous layers were pooled and extracted with Et 2 O. The organic layers were combined and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure deprotected 24-desmethyl-25-des(2-butyl)-23-nor-25-cyclohexyl-23-thia-ivermectin B1 (91 mg, 84%) was obtained by flash chromatography on silica gel using 3:1 EtOAc:hexanes as eluant.
EXAMPLE 25
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-25-tert-butyl-23-thia-ivermectin B1
108 mg Tris-silyl ether VIIf (91 μmol) was placed in 4 mL THF at RT to which was added 1 mL HF.pyridine solution (25 g HF.pyridine, 10 mL pyridine, 25 mL THF). After 48 hrs, the solution was poured into 40 mL 1:1 water:Et 2 O. The layers were separated and neutralized separately with saturated NaHCO 3 . The aqueous layers were pooled and extracted with Et 2 O. The organic layers were combined and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure deprotected 24-desmethyl-25-des(2-butyl)-23-nor-25-tert-butyl-23-thia-ivermectin B1 (73 mg, 90%) was obtained by flash chromatography on silica gel using 6:4 EtOAc:hexanes as eluant.
EXAMPLE 26
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-23-sulfinyl-ivermectin B1 (VIIIa) and 24-desmethyl-25-des(2-butyl)-23-nor-23-sulfonylivermectin B1 (IXa)
40 mg of 24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-23-thia-ivermectin B1 (48 μmol) was cooled to 0° C. in 2 mL methylene chloride to which was added 15 mg meta-chloroperbenzoic acid (72 μmol). After 10 min at 0° C., the solution was warmed to RT and stirred for 1 hr. The solution was purified without workup by flash chromatography on silica gel using EtOAc to elute IXa (6 mg, 14%) and 1:9 MeOH:EtOAc to elute VIIIa (34 mg, 84%). Both VIIIa and IXa were white powders.
EXAMPLE 27
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-25-phenyl-23-sulfinyl-ivermectin B1 (VIIIb) and 24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-25-phenyl-23-sulfonyl-ivermectin B1 (IXb)
36 mg of 24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-thia-ivermectin B1 (40 μmol) was cooled to 0° C. in 2 mL methylene chloride to which was added 15 mg meta-chloroperbenzoic acid (72 μmol). After 10 min at 0° C., the solution was warmed to RT and stirred for 1 hr. The solution was purified without workup by flash chromatography on silica gel using EtOAc to elute IXb (12 mg, 34%) and 1:9 MeOH:EtOAc to elute VIIIb (21 mg, 59%). Both VIIIb and IXb were white powders.
EXAMPLE 28
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-sulfinyl-ivermectin B1 (VIIIc) and 24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-sulfonyl-ivermectin B1 (IXc)
27 mg of 24-desmethyl-25-des(2-butyl)-23-nor-25-iso-propyl-23-thia-ivermectin B1 (31 μmol) was cooled to 0° C. in 2 mL methylene chloride to which was added 15 mg meta-chloroperbenzoic acid (72 μmol). After 10 min at 0° C., the solution was warmed to RT and stirred for 1 hr. The solution was purified without workup by flash chromatography on silica gel using EtOAc to elute IXc (10 mg, 35%) and 1:9 MeOH:EtOAc to elute VIIIc (12 mg, 45%). Both VIIIc and IXc were white powders.
EXAMPLE 29
Preparation of 24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-25-cyclohexyl-23-sulfinyl-ivermectin B1 (VIIId) and 24-desmethyl-25-des(2-butyl)-23-nor-25-cyclohexyl-23-sulfonyl-ivermectin B1 (IXd)
31 mg 24-desmethyl-25-des(2-butyl)-23-nor-25-cyclohexyl-23-thia-ivermectin B1 (34 μmol) was cooled to 0° C. in 2 mL methylene chloride to which was added 15 mg meta-chloroperbenzoic acid (72 μmol). After 10 min at 0° C., the solution was warmed to RT and stirred for 1 hr. The solution was purified without workup by flash chromatography on silica gel using EtOAc to elute IXd (17 mg, 53%) and 1:9 MeOH:EtOAc to elute VIIId (14 mg, 44%). Both VIIId and IXd were white powders.
EXAMPLE 30
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-(methyl 2R,3R,4S-2,4-dimethylhexanoate)-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-phenyl-23-thia-25-oxo-ivermectin B1 (XIIId)
210 mg Triflate Vb (154 μmol) was dissolved in 1 mL dimethylformamide at RT to which was added 5 mg 18-crown-6, 250 mg α-mercaptoacetophenone and 200 mg K 2 CO 3 . After 30 min, 2 mL saturated NaHCO 3 and 2 mL brine were added, the solution extracted with EtOAc and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure XIIId (159 mg, 69%) was obtained as a white solid after flash chromatography on silica gel using 15:85 to 20:80 EtOAc:hexanes gradient elution.
EXAMPLE 31
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-(methyl 2R,3R,4S-2,4-dimethylhexanoate)-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-25-tert-butyl-23-thia-25-oxo-ivermectin B1 (XIIIe)
136 mg Triflate Vb (100 μmol) was dissolved in 2 mL dimethylformamide at RT to which was added 5 mg 18-crown-6, 249 mg α-mercaptopinacolone and 130 mg K 2 CO 3 . After 30 min, 2 mL saturated NaHCO 3 and 2 mL brine were added, the solution extracted with EtOAc and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure XIIIe (127 mg, 94%) was obtained as a white solid after flash chromatography on silica gel using 4:1:1 to 3:1:1 hexanes:CH 2 Cl 2 :tert-BuOMe gradient elution.
EXAMPLE 32
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-25-oxo-23-thia-ivermectin B1 (XI)
160 mg Alcohol VIa (138 μmol) was dissolved in 4 mL methylene chloride at RT to which was added 63 mg Dess-Martin reagent (150 μmol). After 20 min, the solution was purified without workup by flash chromatography on silica gel with 1:1 hexanes:EtOAc as eluant. Pure XI (105 mg, 66%) was thus obtained as a white powder.
EXAMPLE 33
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-methoxy-21,25-seco-24-desmethyl-25-des(2-butyl)-23-nor-22-hydro-25-phenyl-25-oxo-23-thia-ivermectin B1 (XIIIb)
100 mg Alcohol VIc (81 μmol) was dissolved in 2 mL methylene chloride to which was added 75 mg Dess-Martin reagent (178 μmol). After 15 min, the solution was placed directly on a flash chromatography column without workup and eluted with 1:3 EtOAc:hexanes to yield 54 mg XIIIb (54%) as a white powder.
EXAMPLE 34
Preparation of 4",5-bis-O-tert-butyldimethylsilyl-7-O-trimethylsilyl-21-(methyl 2R,3R,4S-2,4-dimethylhexanoate)-21,25-seco-24-desmethyl-25-des(2-butyl)-22-mercapto-ivermectin B1 (XII)
199 mg Triflate Vb (146 μmol) was dissolved in 2 mL dimethylformamide at RT to which was added 57 mg potassium thioacetate (500 μmol). After 1 hr, the solution was placed directly on a 1.5 inch silica gel plug and eluted with 1:3 EtOAc:hexanes to yield pure thioacetate (162 mg, 86%) as a white powder. The thioacetate (162 mg, 126 μmol) was dissolved in methanol at 0° C. to which was added 200 mg NaBH 4 . The solution was poured into 20 mL saturated NH 4 Cl, extracted with EtOAc and dried (MgSO 4 ). The solution was filtered and concentrated under reduced pressure. Pure XII (122 mg, 70%) was obtained as a white solid following flash chromatography on silica gel using 2:8 EtOAc:hexanes as eluant.
EXAMPLE 35
Preparation of 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-phenyl ivermectin B1 aglycone
Add 200 mg 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-phenyl ivermectin B1 to a 1% solution of sulfuric acid in 6 mL methanol at RT and stir the solution of 12 hrs. Pour the solution into saturated ice-cold NaHCO 3 , extract with EtOAc and dry (MgSO 4 ). Filter and concentrate the solution under reduced pressure. Pure 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-phenyl ivermectin B1 aglycone may be obtained following flash chromatography on silica gel.
EXAMPLE 36
Preparation of 23-nor-23-thia-24-desmethyl-25-des(2-butyl)-5-deoxy-5-ketoxime-25-sec-butyl ivermectin B1
Dissolve 200 mg 23-nor-23-thia-24-desmethyl-25-des(2-butyl)-25-sec-butyl ivermectin B1 in 4 mL EtOAc at RT and add to it 300 mg MnO 2 . Stir the solution for 1 hr, then filter the solution through a bed of celite and concentrate the solution under reduced pressure. Pure 23-nor-23-thia-24-desmethyl-5-keto-25-des(2-butyl)-25-sec-butyl ivermectin B 1 may be obtained following flash chromatography on silica gel. Place 100 mg 23-nor-23-thia-24-desmethyl-5-keto-25-des(2-butyl)-25-sec-butyl ivermectin B 1 in 4 mL EtOAc and add 0.150 mL 1.0M zinc chloride in ether followed by 0.10 mL TMSONH 2 . Stir for two hrs at RT, add 1 mL saturated NaHCO 3 and stir for 15 additional minutes. Dilute the solution with 4 mL water, extract with ethyl acetate and dry (MgSO 4 ). Filter and concentrate the solution under reduced pressure. Pure 23-nor-23-thia-24-desmethyl-25-des(2-butyl)-5-deoxy-5-ketoxime-25-sec-butyl ivermectin B1 may be obtained following flash chromatography on silica gel.
EXAMPLE 37
Preparation of 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-25-tert-butyl ivermectin B1
Place 200 mg 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-25-tert-butyl ivermectin B1 in 3 mL dimethylformamide at RT and add to it 66 mg imidazole and 73 mg tert-butyldimethylsilyl chloride. Stir for 2 hrs at RT and then pour into water, extract with EtOAc and dry (MgSO 4 ). Filter the solution and concentrate under reduced pressure. Pure 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-25-tert-butyl ivermectin B1 may be obtained following flash chromatography on silica gel.
EXAMPLE 38
Preparation of 23-nor-23-sulfonyl-24-desmethyl-25des(2-butyl)-5-O-tert-butyldimethylsilyl-4"-oxo-25-tert-butyl ivermectin B1
Place 200 mg 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-25-tert-butyl ivermectin B1 in 3 mL isopropyl acetate at -30° C. and to this solution add, sequentially, 0.056 mL diisopropylethylamine, 0.022 mL methyl sulfoxide and 0.044 mL phenylphosphonic dichloride. Warm this solution slowly to RT over 1 hr. Quench the reaction with 1 mL saturated NaHCO 3 , extract with methylene chloride and dry (MgSO 4 ). Filter and concentrate the solution under reduced pressure. Pure 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-0-tert-butyldimethylsilyl-4"-oxo-25-tert-butyl ivermectin B1 may be obtained following flash chromatography on silica gel.
EXAMPLE 39
Preparation of 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O -tert-butyldimethylsilyl-4"-deoxy-4"-amino-25-tert-butyl ivermectin B1
Place 100 mg 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O -tert-butyldimethylsilyl-4"-oxo-25-tert-butyl ivermectin B1 in 3 mL methanol with 160 mg ammonium acetate and to this add 12 mg sodium cyanoborohydride. Stir the reaction at RT for 1 hr and then pour into saturated NaHCO 3 . Extract the organic products with EtOAc, dry (MgSO 4 ), filter and concentrate the solution under reduced pressure. Pure 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O -tert-bytyldimethylsilyl-4"-amino-25-tert-butyl ivermectin B1 may be obtained following flash chromatography on silica gel.
EXAMPLE 40
Preparation of 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-4"-deoxy-4"-acetylamino-25-tert-butyl ivermectin B1
Place 50 mg 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-4"-amino-25-tert-butyl ivermectin B1 in 2 mL methylene chloride at 0° C. and add 0.20 mL pyridine, 25 mg 4-dimethyl-aminopyridine and 0.10 mL acetic anhydride. After 3 hrs at 0° C., pure 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-4"-acetylamino-25-tert-butyl ivermectin B1 may be obtained following flash chromatography on silica gel.
EXAMPLE 41
Preparation of 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-4"-deoxy-4"-acetylamino-25-tert-butyl ivermectin B1
Place 25 mg 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-5-O-tert-butyldimethylsilyl-4"-acetylamino-25-tert-butyl ivermectin B1 in 4 mL THF at RT and add 1 mL HF.pyridine solution (25 g HF.pyridine, 10 mL pyridine, 25 mL THF) and stir for 12 hrs. Pour the solution into 20 mL 1:1 water:Et 2 O. Neutralize each layer with saturated NaHCO 3 and extract the aqueous layer with ether. Dry (MgSO 4 ) the combined organic layers. Filter the solution and concentrate it under reduced pressure. Pure 23-nor-23-sulfonyl-24-desmethyl-25-des(2-butyl)-4"-acetylamino-25-tert-butyl ivermectin B1 may be obtained following flash chromatography on silica gel. | Avermectin analogs are prepared where the 23-position ring carbon atom is deleted and replaced by a sulfur atom. The compounds are prepared by opening the outer spiroketal ring to gain access to the 23-position atom, substituting the ring-opened compounds with a substituent containing the sulfur atom in the appropriate position and closing the ring to prepare the desired compounds. The compounds are potent anthelmintic agents and methods and compositions including such 23-nor-23-thia compounds are also disclosed. | 2 |
BACKGROUND OF THE INVENTION
Decontamination of sub-systems of LWR plants has now become relatively common in the United States and is important as a useful contributor to the reduction of radiation exposure of workers at these plants. Sub-system decontamination involves exposing a part of the reactor circuit to chemical decontamination solutions which dissolve radioactive deposits which have accumulated on process equipment which includes piping. The spent decontamination solutions may then be treated by ion exchange to retain the chemical and radioactive burden of the decontamination solution on the resin, while clean water is returned to the system. An example of such a process is the LOMI process, described in U.S. Pat. No. 4,705,573.
One of the purposes of decontamination is to remove the radioactive deposits which can represent a danger to plant workers. Decontamination of plant components which are intended to be returned to service should avoid any damage to materials exposed to the process. Such damage could occur due to corrosion resulting from the process or from normal operating conditions of the nuclear plant subsequent to decontamination. Certain processes which attempt to avoid damage do not attack base metal and operate by dissolving the overlying layer of corrosion product metal oxides.
Although effective in lowering or reducing the amount of radiation to which workers are exposed, such processes do not remove all radioactivity from treated surfaces and are therefore not capable of allowing the plant items to be treated as non-radioactive waste. In order to sufficiently decontaminate radioactive items to be able to classify them as non-radioactive, it is necessary to remove a thin layer of the underlying base metal, so as to release radioactivity trapped in fissures in the metal (occurring, for example, as a result of mild intergranular attack of the metal surface.) For decommissioning a reactor, restrictions concerning plant damage are not as stringent since the plant items are not required for further operational duty. The only requirement with regard to damage is that the plant items maintain their integrity against leakage during the operation of the process while remaining structurally sound. Although the removal of a thin layer of base metal is consistent with these requirements, removal of too much metal may cause a problem concerning the amount of radioactive waste generated.
Several processes have been described for removal of base metal. For example, U.S. Pat. No. 4,828,759 is directed to a process for using fluoroboric acid as a decontaminating reagent. The reagent is capable of dissolving a wide variety of metals and metal oxides. The patent details several methods for using the acid to minimize radioactive waste, for example, recovering the acid by distillation. The process described may be convenient for treating components which are immersed or sprayed in a bath for decontamination. The concentration of acid stated (0.05 to 50 moles per liter) is sufficiently great to avoid the complications of ineffectiveness referred to below.
In some instances, using a dilute chemical system may be advantageous when decontaminating large components of nuclear plants, such as steam generators. The purchase and handling of chemicals is difficult and expensive if concentrated chemical solutions are used, and it is difficult to manage the wastes in a minimum volume. Although a process described in U.S. Pat. No. 4,828,759 overcomes many of these difficulties, the type of equipment proposed is not commonly used in a temporary manner in nuclear plant decontamination, and the process does not easily allow the benefits of exposing the items to be decontaminated to a progressively cleaner decontamination solution. Use of progressively cleaner decontamination solutions is useful for obtaining high decontamination effectiveness in a large convoluted system of plant items contaminated on inaccessible internal surfaces.
Another decontamination solution capable of dissolving base metal involves cerium salts in an acid solution (e.g. German Patent No. DE-PS 2, 714,245). The oxidizing action of cerium (IV) in conjunction with a mineral acid such as nitric acid causes the metals to be dissolved. The cerium (III) resulting from oxidation of the metal can be reoxidized to cerium (IV) by the action of an oxidizing chemical such as ozone. The problem with systems based on cerium as oxidant is that cerium is cationic and is removed and depleted along with metals and radioactivity by ion exchange. It is therefore difficult to provide a system that allows continuous removal of cationic radioactive metals without consequent removal of cerium. The desired objective of treating the system with a progressively cleaner decontamination solution cannot therefore be accomplished conveniently.
SUMMARY OF THE INVENTION
The present invention provides a process for decontaminating a contaminated material which includes providing a solution containing from about 1 to about 50 milli-moles of fluoroboric acid per liter, contacting the solution with a material which causes the oxidation potential (Eh) of the fluoroboric acid solution to range from about 500 to about 1200 mV versus a Standard Calomel Electrode, and contacting the fluoroboric acid solution with the contaminated material and removing a contaminant by contacting the fluoroboric acid solution with a cation exchange resin.
The present invention also provides a process for removing metal from a substrate which includes providing a solution containing from about 1 to about 50 milli-moles of fluoroboric acid per liter, contacting the solution with a material which causes the oxidation potential (Eh) of the fluoroboric acid solution to range from about 500 to about 1200 mV versus a Standard Calomel Electrode, and contacting the fluoroboric acid solution with the substrate and removing metal from the substrate. The metal is removed or recovered from the fluoroboric acid solution by contacting it with a cation exchange resin.
In one aspect, it is an object of the invention to provide decontamination by progressively removing deposits and/or a layer of base metal from a surface in an even and controlled manner, thereby releasing radioactive contamination. In another aspect, it is an object of the invention to allow the surface to be treated with a progressively cleaner decontamination solution as the process proceeds. In yet another aspect, it is an object of the invention to create a minimum volume of radioactive waste from the process.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a process block diagram with the major components of the decontamination system of the present invention.
FIGS. 2a-d show a series of EDAX analyses of test coupon surfaces.
DETAILED DESCRIPTION OF THE INVENTION
The present invention was developed for the purpose of decontaminating items of nuclear plant which are no longer required for duty. Such items may arise because the whole facility has been taken out of commission, or because a single item (such as a steam generator of a PWR plant) is being replaced. In accordance with the present invention, a decontamination system is provided which uses a dilute reagent that affords easy and economical handling. The decontamination system evenly dissolves base metals and corrosive deposits and is especially well-suited for decontamination of reactor plant components which have been taken out of commission. Furthermore, the system also utilizes certain reagents which can be removed in the gas phase or be converted into species which can be removed in the gas phase, thus leaving no residue. It should be understood that the present invention is applicable not only to removal of radioactive deposits from a substrate, but to removal of non-radioactive deposits, metals, derivatives of metals, and other materials from an underlying substrate.
The chemical reagents used should be dilute (ideally no more than 10 milli-moles per liter) because the quantity of radioactive ion exchange wastes generated is heavily dependent on the quantity of reagents used. There are additional reasons for preferring a dilute chemical concentration, for example, simplification of handing the chemicals on a large plant scale. It was therefore desired to develop a chemical system which was dilute and could evenly dissolve base metal while at the same time being suitable for a recirculating clean up by ion exchange.
The present invention avoids the use of cationic chemical reagents in the decontamination solution for the following reason. In order to achieve a high degree of decontamination effectiveness in a plant system of complex geometry, it is necessary for the system to be treated with solution of progressively lower radioactive content, preferably at the same time as the base metal is being dissolved. In this way it is possible to avoid the potential for recontamination of freshly exposed clean steel surfaces. In a nuclear plant which has not been operational for a period in excess of one year most of the radioactivity typically present in the reactor circuits is in the form of elements which are cationic. Provided that the chemical reagent does not contain a cation (other than hydrogen ion) it is possible to remove the dissolved radioactive elements on a cation exchange resin without removing the chemical reagent. This principle has been used advantageously in other prior art processes which do not dissolve base metal. (e.g. the CANDECON process, See, P. J. Petit, J. E. LeSurf, W. B. Stewart and S. B. Vaughan, Corrosion '78, Houston, Tex., 1978).
Prior to the present invention, it was believed that use of fluoroboric acid as a decontamination reagent was ineffective when the concentration of the acid was reduced to an extent sufficient to make its use practical in a large plant system. The reason for this ineffectiveness is the nature of metal oxides deposited or grown on to metal surfaces at high temperatures during reactor operation. Such oxides are soluble only slowly in the dilute fluoroboric acid. The acid penetrates cracks in the oxide structure leaving islands of adherent oxide while the metal at the base of the cracks is dissolved. This behavior has been confirmed by electron microscopy of pre-oxidized metal samples exposed to dilute fluoroboric acid. We have undertaken tests of the effectiveness of fluoroboric acid at controlled conditions of oxidation potential, Eh. The Eh in these experiments has been monitored and controlled by additions of hydrazine, hydrogen peroxide or ozone. In these experiments we have found that the oxide is dissolved much more evenly particularly on stainless steel, as the Eh of the system is increased. Furthermore the rate of removal of oxide from stainless steel is affected far more by Eh than Inconel. The result is that at high values of Eh the rate of removal from both types of metal becomes approximately equal, which is convenient from the point of view of decontaminating a mixed stainless steel/Inconel system.
Turning now to FIG. 1, the items of a plant are formed into a flowpath typically with a process skid 10. The process skid 10 consists of equipment which can be transported easily between one site and another, and connected to the nuclear plant items by temporary pipework 12. The components of the process skid are typically a pump, in-line heater, ozone generator 14, ion exchange vessels 16 and 18, surge tank, and suitable equipment 20 for chemical injection.
The system is filled with water (preferably deionized) and the water is circulated through the system while being heated to the process temperature. The temperature in which the process operates can be from about ambient temperature to about 100° C., but the most preferable range is about 65° C. to about 100° C. The choice of temperature is based upon the rate of dissolution of metal desired. The metal must dissolve sufficiently slowly for the solution to have an invariant pH in all pans of the flowpath, but must dissolve sufficiently rapidly for the process application time to be convenient. Typically, a convenient time for application would be defined as between about two and about forty eight hours. Fluoroboric acid is then injected in concentrated solution, typically 48% (wt) in water, into the system to achieve a concentration in the desired range. This range is about 1 to about 50 milli-moles per liter, but more preferably about 10 milli-moles per liter. Periodically during operation of the process further fluoroboric acid can be injected to maintain the desired concentration. It is important that the desired pH and Eh be maintained throughout the decontamination process.
Ozone is injected from the ozone generator. The ozone generator may be any commercially available device for this purpose, for example, operating on the principle of electric discharge in air or oxygen. (Corona Discharge Ozone Generator, Peak Scientific, United Kingdom.) Optionally ozone present in off gases can be recycled through the solution. The ozone injection rate is controlled throughout the process to achieve the desired value of oxidation potential (Eh) which should be maintained in the range of about 500 to about 1200 mV versus the Standard Calomel Electrode. Off gases from the system should be vented though an ozone filter, of standard commercially available type, to prevent ozone from entering the atmosphere. From there, off gases should be vented to the plant extract system.
The cation exchange column is valved into the system. The rate of flow of solution through the cation exchange column is controlled to maintain the pH of the circulating solution in the correct range. This range is about pH 2 to about pH 3, but most preferably about pH 2.5. Cation and anion exchange resins used for the process may be any ion exchange resins typically used for water purification in the nuclear industry, preferably strong acid cation exchangers such as IR-120 and strong base anion exchangers such as IRA 400.
During the operation of the process the progress of the decontamination may be monitored by measuring the radioactivity circulating in the process solution (by sampling and analysis), and, if convenient, by direct gamma monitoring equipment adjacent to the items to be decontaminated. The majority of the radioactivity is removed by the cation exchange resin, so that the circulating solution has progressively lower levels of circulating radioactivity. The process is complete when no further radioactivity is being removed from the system. During the final cleanup stage, the process solution is circulated through the flowpath and through cation and anion exchange columns, until the desired purity of process water is achieved (e.g., conductivity of about 10 microSiemens). The fluoroboric acid is removed from the system by the anion exchange columns, leaving the system with clean water.
After completion of the process the water can be removed from the system, and the ion exchange resin can be disposed of as radioactive waste in any conventional manner, e.g., hydraulically transferred into a liner for dewatering or other treatment prior to transportation and disposal.
EXAMPLE 1
Sample coupons of Stainless Steel 304 and Inconel 600 were obtained from Metal Samples Inc., Alabama. Coupons were traceable to mill certificates, and were oxidized by the following procedure to produce an oxide coating which has been shown to simulate exposure of the materials to PWR reactor conditions. The samples were degreased in methanol and pickled for 2 minutes in 30% nitric acid (for stainless steel coupons) or 30% sulfuric acid for Inconel coupons. The coupons were washed in demineralized water, rinsed with methanol, and dried in a dessicator to constant weight. The coupons were heated in air at 800 C. for a period of 15 minutes. Average oxide film thicknesses (0.85 microns stainless steel and 0.58 microns Inconel) were calculated from weight gains assuming that the weight gain was due to incorporation of oxygen and that the oxide density was 1.5 gcm -3 . Scanning electron micrography and EDAX analysis of the coupon surfaces revealed enrichment in oxygen and chromium compared with the base metal, both in the case of the stainless steel and Inconel coupons (FIG. 2).
A recirculating decontamination rig was constructed with a PTFE sample chamber, generally according to the diagram in FIG. 1, though in this particular case no anion exchange column was employed. The system volume was 10 dm 3 and the linear flow rate over the coupons was 0.07 m s -1 . A cation exchange column of 0.5 dm 3 capacity (IR-120) in the hydrogen form was provided. The design allowed control of flow rates, temperature and chemical concentrations. Temperature, pH, Eh and flow rate were all recorded on a data logger system. Grab samples of the solution were taken from the bulk recirculating solution and in the outlet from the cation exchange column at various times, and sent for analysis (iron, chromium, nickel and pH). The specimens were placed in the sample chamber and the system filled with demineralized water. The solution was heated to 65 C. Fluoroboric acid was added (13.5 ml, 48% by weight in water) and the ozone generator switched on. Initially the cation exchange column was isolated, but after four hours the ion exchange column was valved in at a flow rate of 10 dm 3 h -1 . Analysis of the bulk solution and "after cation exchange" samples are given in Table 1. Eh was maintained between +600 and +1,000 mV versus Standard Calomel Electrode. The decontamination was continued for 24 hours. After this the coupons were removed, rinsed in demineralized water, dried in air and examined for weight loss and surface appearance and by scanning electron micrography and EDAX.
After exposure the coupons, which had previously had a dark oxide coating, were found to have a bright metallic appearance similar to that before the oxidation procedure. The absence of oxide was confirmed by EDAX analysis and the composition of the surface was equivalent to the base metal (i.e. no chromium enrichment). Weight loss calculation indicated that the coupons had lost approximately 5.44 mg cm -2 Inconel and 0.90 mg cm -2 Stainless Steel.
The ion exchange resin was visually examined, and no signs of damage had occurred, neither was there any reduction in flow rate or increase in pressure drop during the experiment, and there was no discernible loss in ion exchange capacity (conversion between hydrogen and sodium forms). It can be seen from the analytical results that the ion exchange column had operated exactly as predicted, lowering the pH and removing the metals.
TABLE 1______________________________________ ##STR1##______________________________________ * Commencement of Cation IX treatment ND = Not Detected = below 50 ppb
EXAMPLE 2
Sample coupons were obtained from the primary circuit of an operational PWR. These samples were a specimen of Inconel 600 Steam Generator tube and a stainless steel coupon (Type 304L) from a man access cover. Analysis of radionuclides on the two coupons indicated 126 kBq cm -2 Co-60 on the stainless steel and 103 kBq cm -2 Co-58, 0.18 kBq cm -2 Co-57 and 1.23 kBq cm -2 Mn-54 on the Inconel tube. Non-radioactive surfaces of the coupons were blanked off with a silicone coating to prevent exposure to the decontamination solution.
The sample coupons were treated in the decontamination rig as in Example 1, except that the ion exchange resin used was a 1:1 mixed bed of IR-120 cation resin and IRA-400 anion resin previously regenerated with fluoroboric acid (i.e. the anion resin was in the fluoroborate form). The samples were measured for radioactivity by gamma spectrometry.
The process was operated for a period of 31 (Thirty One) hours using the same conditions as in Example 1. The sample holder and ion exchange column were monitored for decreasing and increasing radioactivity (respectively). After decontamination the samples were again measured using gamma spectrometry. The decontamination factors (Co-60 on the specimens before decontamination divided by Co-60 on the specimens after treatment) were 28 (Twenty Eight) for Inconel and 4 (Four) for Stainless steel. The process was discontinued at 31 (Thirty One) hours, but it was estimated that further running time of about 12 (Twelve) hours would complete the oxide and radioactivity removal.
The above-described embodiments and examples are illustrative of the present invention and should not be construed as limiting. Consequently, modifications may be made by those with skill in the art that are intended to be covered by the following claims. | A process for removing undesirable material such as a radioactive contaminant from an underlying material. A solution containing fluoroboric acid and a material which affects oxidation potential (Eh) is contacted with the undesirable material to cause its removal. The material is removed from the fluoroboric acid solution by contacting the solution with a cation exchange resin and fluoroboric acid is regenerated in situ for continuous removal of undesirable material. | 2 |
CROSS REFERENCE TO RELATED APPLICATION(S)
This is a continuation of copending application(s) Ser. No. 07/484151 filed on Feb. 23, 1990, now abandoned.
TECHNICAL FIELD
This invention relates generally to electrophotographic or laser printers and more particularly to a laser printer having a large number of scalable typefaces available from a given amount of printer memory. These laser printers are manufacturable at a relatively low cost and they represent a significant price/performance breakthrough in the art and technology of laser printing.
BACKGROUND ART
Electrophotographic or laser printers have been commercially available for several years and are known to provide some of the highest forms of print quality on the printed media in all of the fields of both impact and non-impact printing. An example of these laser printers is the Hewlett-Packard LaserJet Series II printers which are described in the LaserJet Series II User's Manual, part number 33440-90901 available from the Hewlett-Packard Company (HP) of Palo Alto, Calif. These Hewlett-Packard LaserJet Series II printers include, among other things, means for receiving user input printer language commands via a computer interface cable, means for interpreting these user input printer language commands such as the Hewlett-Packard Printer Command Language (PCL), and means connected to these interpreting means for accessing the appropriate digital data from printer memory. This digital data is accessed and processed in order to obtain corresponding printable character data representative of a particular size, treatment (e.g., style and stroke weight), and print orientation. This type of character data is also known in the art as bitmap data. This character data is in turn used for controlling a laser beam of the laser printer, and the laser beam in turn is operative to write a printed image on a photoconductive drum of the laser printer. The printed image is then transferred from the photoconductive drum to an adjacent print media as is well known in this art.
As used herein and as is generally understood in this art, the term "typeface" is defined as a group of characters that have similar design features. Often a typeface will be available in several treatments, e.g., bold, italic, etcetera. Within the HP LaserJet Series II and all other HP PCL printers, characters within a typeface are accessed by a user through character sets. The term "character set" as used herein and as is generally understood by those skilled in the art is defined as a grouping of characters, generally containing many less characters than all characters designed for typeface, and arranged with a specific printer application in mind. For example, the legal and math character sets are generally designed to support legal and scientific applications, and they contain only those characters used in the particular application (e.g., there is no square root character in the legal character set).
Whereas these HP LaserJet Series II printers have been highly regarded and widely accepted by consumers throughout the world as the latest in state-of-the-art laser printing technology, these laser printers nonetheless have an upper limit on the number of characters in unique character sets and typeface treatments which are available from a given amount of memory storage capacity of the printer. This memory for the HP LaserJet Series II printer is read-only-memory (ROM).
One reason for this upper limit on the memory for character storage capability of the HP LaserJet Series II printer is that this printer was designed so that each character of each typeface in each treatment and for each size was stored separately in memory and represented with unique digital data (i.e., bitmap data) therein. This was true even though certain characters are common across multiple typefaces and typeface treatments. This latter design characteristic of the HP LaserJet Series II printer obviously required a significant duplication of memory storage for identical characters in the different available typeface treatments.
The above duplication of ROM memory storage is undesirable for a number of reasons. Firstly, the requirement for additional ROM to add character storage capability to a laser printer can mean an additional ROM cost of between $9.00 and $12.00 per ROM semiconductor chip. When this additional cost is multiplied by a standard manufacturing cost multiplier of typically between 3 and 4, this can mean adding as much as $50.00 to the consumer cost in an extremely competitive marketplace.
Secondly, the requirement for adding more ROM memory capability to a laser printer means the addition of more pins on the printed circuit board which supports the ROMs, and this in turn means lowering printer reliability. Thus, the high desirability of minimizing memory storage (ROM) requirements in laser printers while simultaneously maximizing the character storage capability of the printer is manifest.
DISCLOSURE OF INVENTION
Accordingly, the general purpose and principal object of the present invention is to maximize the number of available printable characters for a laser printer for a given amount of printer memory storage capacity, such as in a given number of semiconductor read-only-memories on a printer's controller board or in plug-in type cartridges therefor.
To accomplish this purpose, we have discovered and developed a method and system for processing information or data between an input/output data stream for a laser printer and an output print control mechanism therefor which includes storing in memory a plurality of character set mappings defined as "recipes" for creating character sets for a chosen application or language from the characters stored in the ROM memory. The characters stored in memory have numbers associated with them that are independent of particular characters sets and are organized into several categories including those characters specific to a given typeface and treatment (typeface sensitive), those characters whose design and appearance varies among several classes and/or treatments of typefaces but are common to more than one typeface (limited sensitivity), and finally those characters whose appearance does not vary between typefaces (universal), and are therefore in every typeface. A character set map is used to determine the number of the character specified by a user. The typeface sensitive characters group is the largest and most commonly used, and is therefore searched first for a character corresponding to the one the user has specified. If no match is found, the limited sensitivity characters are searched next. Again, if no match is found, the universal characters are searched. Once the character data is located, the character is scaled to a desired height and width, and this process may be repeated several times for characters that are composites of several pieces. The novel combination of: (1) the character set mapping and multiple use of limited sensitivity and universal characters and (2) the subsequent scaling and character composition thereof maximizes the character storage capability for the printer for a given amount of printer memory available.
Another object of this invention is to provide a new and improved laser printer of the type described whose manufacturing and consumer costs have been minimized, while simultaneously maximizing printer reliability.
A unique feature of this invention is the provision of character scaling means connected to receive character data stored in printer memory and operative for scaling a character selected from one of the memories or memory sites to a desired height and width, thereby providing variable size character input data for driving a printing mechanism.
Another feature of this invention is the provision of a method and system of the type described which includes means for dividing the characters for printing into a plurality of character groupings or collections which are based upon a need for character variability. These groupings or collections include typeface sensitive characters, limited sensitivity characters, and universal characters which are described below.
The above objects, features, and various other advantages of this invention will become better understood and appreciated with reference to the following descriptions of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of the laser printer and control system therefor according to the present invention.
FIG. 2 is a functional block diagram of one example of the organization of the typeface character data and memory interface shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the new and improved laser printer 10 according to the present invention includes therein a novel laser printer control system 12 which is connected to receive its input command data from an operator at a computer 14. The computer 14 is connected to the control system 12 by way of a cable 16, and the hardcopy output of the laser printer is derived from a sheet feed and collection mechanism 18. As is known in the art, the hardcopy output at the media collection stage 18 is produced by a laser printer mechanism 20 which includes, among other things, means for controlling a laser beam which is used to write a printed image on a photoconductive drum. This printed image is transferred from the photoconductive drum to an adjacent print media (neither shown) as is also well known in the art. In the embodiment shown in FIG. 1, the printed media will normally be cut sheets of laser printed output hardcopy available at stage 18.
The input command data received via cable 16 is received and interpreted by a printer language interpretation program 22 located on the printer controller board (not shown). This program 22 records the commands that specify the user's desired character set, size, treatment, and typeface. When this program subsequently receives commands to print particular characters, it generates a command signal on line 24 which is applied to a character processor 26. The character processor 26 in turn executes a character processing program that makes the appropriate electrical connections via line 37 to read the ROMs 28 containing scalable character data. The ROM containing the character set maps 30 is accessed first. The character set map corresponding to the user requested character set is located by way of a linear search. Once the map is located, the memory location within the map corresponding to the character set number of the character that the user requested is accessed; therein is stored a number that corresponds to the actual character requested. The character processing program then searches the Group 1 memory 32 containing the typefaces sensitive characters of the requested typeface for the character with the appropriate number. The typeface sensitive characters in Group 1 memory 32 are searched first because there is the greatest probability that the character will be found in this group.
If the requested character is not located among the typeface sensitive characters in the Group 1 memory 32, the appropriate limited sensitivity characters in Group 2 memory 34 are searched. If a requested character is still not located, the universal characters in Group 3 memory 36 are searched. Once the desired character is located, the data describing this character is copied by the character processor and applied via line 27 to a temporary location in a random-access-memory (RAM) 38. A character scaling program is then executed in a character scaler stage 40 by a signal applied via line 25 from the character processor 26. This program reads the character data stored in the RAM 38 via line 29 and generates a printable character that corresponds to the user requested character size. This printable character is then stored in RAM 38 for latter access by a program in an engine controller 42. The engine controller program in stage 42 then reads the RAM 38 via a signal on line 41 and sends the printable character data to the laser printing mechanism 20. The laser printing mechanism 20 places the character image on the photoconductive drum which is subsequently transferred to a sheet of paper, a process well known in the art.
As will be readily appreciated by those skilled in the art, this unique and elegantly simple division of characters which are grouped in the three memory locations 32, 34, and 36 and which are serially addressed and interrogated as described above using character set maps 30 has the effect of significantly reducing the overall amount of memory required to generate a given number of characters in a laser printer. Or conversely, given a certain upper limit on laser printer memory as dictated, for example, by printer cost and price limitations, the laser printer according to the present invention is constructed to contain and provide a heretofore unavailable maximum amount of character data from which a heretofore unavailable maximum number of unique printed images may be produced.
When used in combination with the above novel character storage and access method and system, the character scaler 40 provides an additional amount of memory saving which is made possible by its ability to scale every individual character to a desired height and width. Laser printers in the prior art, such as the Hewlett-Packard LaserJet Series II printer, have traditionally used separate memory to store the same character of a different size, and this size variability is now provided by the character scaler 40.
The printer command language interpreter 22 per se and the concept of character scaling per se are not new and are not individually claimed as new herein. The particular language used by the interpreter 22 is well known in this art as the HP PCL Printer Command Language, and a further detailed discussion of such language may be found in the LaserJet Series II Technical Reference Manual, HP part number 33440-90905. Similarly, character scaling has been used in various applications in the past to scale characters to a selected height and width. Typesetter controllers and typesetting proofing devices are examples of printing apparatus which have been previously equipped with a character scaling capability. One such typesetter controller device is sold by Compugraphic Division of Agfa Corporation under the tradename of GENICS. However, it will be understood and appreciated from the description herein that the use of character scaling in combination with the character storage format and access techniques represents a novel method combination and a novel system combination useful in maximizing the total character output printing capability for a given amount of printer memory.
Referring now to FIG. 2, the PCL character set maps 30 include for purposes of illustration a map 50 which is identified as "PC-8" and a map 52 which is identified as "Legal". These application-specific maps include therein the character set numbers 0-95 and the character look-up numbers, for example, (3), (34), and (64). These character look-up numbers (3), (34), and (64) are connected as shown, respectively, to the ROMs 34, 32, and 36 which store the Group 2, Group 1, and Group 3 memories, respectively. In FIG. 2, the character processing program in the character processor 26 in FIG. 1 accesses a PCL Printer Command Language character set map 36 that corresponds to the character set requested by the user. These maps contain the look-up number of each of the characters in the selected character set. This look-up number is used when searching the Group 1, 2, and 3 memories 32, 34, and 36.
As an example of operation, a so called " -- " or underscore character may be desirable for use within multiple character sets; however, the underscore character does not vary in appearance across multiple typeface treatments. Therefore, the same underscore character can be used with every one of a large variety of character sets such as those described by the character set maps 30. The underscore character is therefore defined herein as a "universal" character, since it may be used universally among many different typefaces and typeface treatments.
In accordance with the present invention, if a user selects the PC-8 character set followed by typing an underscore character " -- " from the keyboard of his or her computer and then requests that this character be printed, the printer language interpreter program in stage 22 in FIG. 1 then requests that the character processing program in the character processor 26 (FIG. 1) search the ROM 30 for the PC-8 character set map 50. Simultaneously, the character set number location 95 in FIG. 2 is accessed to identify the underscore character's look up number (64). The character processing program in the character processor 26 then searches the Group 1 characters in the ROM 32 for character number 64. Since the underscore character is not in Group 1, the next Group 2 is searched in the ROM 34. Finally, the character Group 3 in the ROM 36 is searched and the underscore character is located. This character data is then copied to the RAM 38 and the character scaler 40 (FIG. 1) uses this data to generate an image of the appropriate size. Therefore, it will be appreciated by those skilled in the art that only a single underscore character now need be stored in ROM, and that duplicate storage of this universal character is totally eliminated in accordance with the present invention.
If a typeface sensitive character such as the letter "A" is selected from the keyboard and printed in either the PC-8 or Legal character sets 30, the corresponding character look-up number (34) will be used to locate the "A" in the requested typeface and treatment. Again, the search begins with the memory in the ROM 32. In this case, the requested typeface sensitive character is found in this first search location. Since "A" is more commonly used than " -- ", the overall access speed of the system is enhanced by virtue of the order in which the three character groups in ROM 32, 34, and 36 are searched.
As a final example, assume that a limited sensitivity character such as the pound sign"#" or number abbreviation sign "#" is selected for printing. There is a need only for a restricted number of different treatments of this character, (medium and bold are shown), as compared to the four different treatments of the typeface "A" shown. This represents a savings in memory storage equivalent to the size of two pound sign characters.
It should be apparent from the above description of FIG. 2 that character set maps 30 are only two of a much larger number of character set maps which may be used in accordance with the present invention. Similarly, the universal characters, limited sensitivity characters, and typeface sensitive characters used for example and illustration in FIG. 2 are representative of a larger number of characters that may be added to the above three storage groupings and made available in accordance with the novel teachings of the present invention.
Various other modifications may be made in and to the above described embodiments without departing from the scope of this invention. For example, if required for certain printing applications, the above three character groupings can be either expanded to a larger number or reduced to two. Furthermore, the present invention is not limited to laser printers and may be used for memory saving purposes in other types of printers such as impact printers, thermal printers, ink jet printers and the like. Accordingly, these types of variations as well as design variations and changes of hardware and software for the systems described above are within the scope of our appended claims. | A novel method and system for operation in combination with a laser printer for expanding its character and typeface selection capability. The sequence and operation for this method and system include dividing a list of characters to be printed into a plurality of character groupings or collections, storing these character groupings or collections in a plurality of different memories or memory sites, and providing an input command signal to these memories or memory sites which corresponds to a selected character desired to be printed. The different memories or memory sites are addressed starting first with the memory or memory site storing the largest character grouping or collection having the most frequently used characters therein and then addressing the different memories or memory sites in sequence to or toward the memory or memory site storing the smallest number of less-frequently used characters therein. In this manner, the memory storage capability and computational speed of the laser printer are maximized, and the price/performance figure of merit and reliability of the printer are also maximized. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a rocker arm made of sheet metal for a valve mechanism of an automobile engine, and a method of manufacturing the same.
The rocker arm furnished to the valve mechanism of the automobile engine is provided with a body made of sheet metal, a roller disposed between side walls of the body, and an axis for rotatably supporting the roller via needle rollers. The axis is non-rotatably inserted in axial holes formed in the side walls of the body. A rotation of cam in contact with the roller oscillates the body, and the valve stem is vertically moved in cooperation with this oscillation to open and close a valve (see, for example, Patent Laid Open No. 2001-55912).
The body of the rocker arm receives load from the cam via the roller. In particular, the surrounds of the axial holes through which the axis passing through the body is inserted receives large load. Therefore, for securing rigidity in response to load, the sheet metal having thickness durable against the load is employed for the material of the body, so that the weight of the rocker arm increases by such an amount of the durable thickness.
Further, in general, the axial holes are formed by punching the sheet metal by an amount of the diameter of the axis, and punched circular parts are scrapped as they are, resulting in lowering yield rate.
SUMMARY OF THE INVENTION
In view of above, an object of the present invention is to provide a rocker arm in which weight is reduced, and a desired rigidity is secured.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) A rocker arm comprising:
a body that is made of sheet metal and includes a pair of side walls; and
a pair of axial holes that are respectively formed through the pair of side walls and have a first diameter and through which an axis is inserted,
wherein the pair of axial holes include thickened portions formed partially or overall of circumference of the pair of axial holes, and
wherein the thickened portion is formed by expanding a hole that has a second diameter smaller than the first diameter and is formed in a pre-arranged range for forming the axial hole in a blank material so as to causing plastic flow in a metallic material of the circumference of the hole.
(2) The rocker arm according to (1), wherein the thickened portion is formed at a portion of the circumference of the axial hole at sides of loading ranges. (3) The rocker arm according to (1), wherein only the thickened portion is projected from the side wall in a direction in which the axis is extended. (4) A method of manufacturing a rocker arm that includes a body that includes a pair of side walls, and a pair of axial holes that are respectively formed through the pair of side walls and have a first diameter and through which an axis is inserted, the method comprising:
forming a hole having a second diameter smaller than the first diameter in a pre-arranged ranges of a blank material; and
expanding the hole having the second diameter to form the axial hole having the first diameter so that a thickened portion is formed partially or overall of a circumference of the axial hole by causing plastic flow in a metallic material of the circumference.
(5) A rocker arm that includes a body that includes a pair of side walls, and a pair of axial holes that are respectively formed through the pair of side walls and have a first diameter and through which an axis is inserted, produced by a method comprising:
forming a hole having a second diameter smaller than the first diameter in a pre-arranged ranges of a blank material; and
expanding the hole having the second diameter to form the axial hole having the first diameter so that a thickened portion is formed partially or overall of a circumference of the axial hole by causing plastic flow in a metallic material of the circumference.
According to the invention, it is possible to attain reduction in weight, and secure a desired rigidity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a disassembled perspective view of the rocker arm concerned with the most preferred embodiment for practicing the invention;
FIG. 2 is a cross sectional view in the central part in the width direction of the rocker arm of FIG. 1 ;
FIG. 3 is a cross sectional view in the central part in the lengthwise direction of the rocker arm of FIG. 1 ;
FIG. 4 is a plan view of the blank for making the body of the rocker arm of FIG. 1 ;
FIG. 5 is a plan view showing the processing procedure of the body of the rocker arm of FIG. 1 ;
FIG. 6 is a disassembled perspective view of the rocker arm concerned with another embodiment of the invention; and
FIG. 7 is a perspective view of the simplex of the body of the rocker arm concerned with a further embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Description will be made to a preferred embodiment according to the invention with reference to the accompanying drawings. FIG. 1 is a perspective view showing the disassembled rocker arm, FIG. 2 is a cross sectional view showing a using condition of the rocker arm, FIG. 3 is a cross sectional view of a central part in the longitudinal direction of the rocker arm, FIG. 4 is a plan view of the blank work, and FIG. 5 is a cross sectional view showing a processing procedure of the body.
Referring to these drawings, reference numeral 1 denotes a cam, and reference number 2 denotes the rocker arm. The cam 1 is rotatably furnished around a cam shaft 3 at a predetermined position of the valve mechanism (not shown). The rocker arm 2 is used to OHC type engine, and is provided with a body 4 made of sheet metal, roller 5 , needle rollers 6 turnably disposed at the side of an inner diameter of the roller 5 , and an axis 7 inserted at the side of an inner diameter of the needle rollers 6 .
The body 4 includes a pair of side walls 8 , 9 being parallel to each other. The axis 7 is bridged between both side walls 8 , 9 and non-rotatably attached to the side walls 8 , 9 by fitting the axis 7 to circumferential faces of the axial holes 8 a , 9 a and expanding opposite end faces 7 a , 7 b outside in the radial direction.
As one of characteristics of the invention, the outer circumferential portions of the axial holes 8 a , 9 a are formed to be thickened portions 10 , 11 having thickness t 2 larger than thickness t 1 of blank materials of opposite side walls 8 , 9 constituting the body 4 . For example, t 2 =1.5×t 1 . Such thickened portions 10 , 11 are formed by causing a metallic material to generate plastic flow when forming the axial holes 8 a , 9 a.
A lash adjuster carrier 12 is provided between both opposite side walls 8 , 9 at one side in the longitudinal direction of the body 4 . A lash adjuster 14 slidably fits at its front end to the lash adjuster carrier 12 .
A valve carrier 13 is provided between opposite side walls 8 , 9 at the other side in the longitudinal direction of the body 4 . The valve carrier 13 is incorporated with a front end 15 a of a valve stem 15 . The body 4 is produced by pressing one sheet of metallic sheet, and opposite side walls 8 , 9 , lash adjuster carrier 12 and valve carrier 13 are formed as one body.
The body 4 of the above structure is made of the sheet metal. In regard to the manufacturing method, the first step is to perform a die-cutting treatment on one sheet of metallic sheet by a pressing process so as to produce a blank material 18 as shown in FIG. 4 . This case employs such a metallic sheet being thinner than metallic sheets used to forming of conventional rocker arms.
In FIG. 4 , reference numerals 19 , 20 denote pre-arranged ranges for forming the side walls 8 , 9 , reference numeral 21 denotes the pre-arranged range for forming the lash adjuster carrier 12 , and reference numeral 22 denotes the pre-arranged range for forming the valve carrier. Reference numerals 23 , 24 denote the pre-arranged ranges for forming the axial holes 8 a , 9 a . At a stage of this blank material, sizes of diameters d 1 of holes 23 a , 24 a formed in the pre-arranged ranges for forming the axial holes 8 a , 9 a are in advance prepared to be enough smaller than the diameter d 2 of the axis 7 .
Next, as shown in FIG. 5 , the diameter d 1 of the holes 23 a , 24 a of the pre-arranged ranges 23 , 24 is expanded for forming the axial holes 8 a , 9 a by means of a suited jig 25 . The expansion process is performed under a condition of holding the blank material 18 at its one side on a metal mold 28 . The metal mold is formed with a releasing part 27 corresponding to the ranges of the axial holes 8 a , 9 a , and the jig 28 is positioned to the holes 23 a , 24 a of the pre-arranged ranges 23 , 24 for forming axial holes 8 a , 9 a , and presses the other side of the blank material 18 . By this method, the holes 23 a , 24 a are expanded, and the metal material by an expanding amount is effected with plastic flow in order to increase thickness as swelling with respect to the pre-arranged ranges 19 , 20 so that thickened portions 10 , 11 are formed.
Then, the pre-arranged ranges 19 , 20 that form the side walls 8 , 9 are bent at the positions shown with imaginary lines 18 a , 18 b of FIG. 4 by a determined metal mold (not shown) so as to form the body having the side walls 8 , 9 , the lash adjuster carrier 12 and the valve carrier 13 as shown in FIG. 1 .
Subsequently, a assembly in which the needle rollers 6 are arranged on the inner circumference of the roller 5 is disposed between the side walls 8 , 9 as shown in FIG. 1 . The axis 7 is inserted from one-side axial hole 9 a toward the other axial hole 8 a , and is fitted to the circumferential face of the axial holes 8 a , 9 a of the side walls 8 , 9 and is expanded at opposite ends 7 a , 7 b outside in an axial direction so that the axis 7 is non-rotatably attached to the axial holes 8 a , 9 a.
An operation of the rocker arm 2 having the above mentioned structure will be explained with reference to FIG. 2 . When the cam 1 rotates under a condition that the cam 1 contacts at its outer circumference to an outer circumference of the roller 5 , the roller 5 rotates around the axis 7 in accordance with the rotation of the cam 1 , and the body 4 is pushed by the cam 1 from a position of a solid line toward a position of two-dotted line via the roller 5 .
Then, the body 4 oscillates around a fulcrum of a front end 14 a of the lash adjuster 14 , whereby the valve stem 15 is vertically reciprocated to open and close the valve of the engine.
In the rocker arm 2 having the above mentioned structure and operation, the axial holes 8 a , 9 a secure rigidity at the outer circumference of the axial holes 8 a , 9 a in such manners that, when forming the axial holes 8 a , 9 a , the metallic material of the blank material is caused with the plastic flow to make the thickened portions 10 , 11 thicker than the thickness of the blank material blank metal material of the side walls 8 , 9 . Therefore, in this rocker arm 2 , even if using the material thinner than the blank material of the body of the conventional rocker arm, the cam 1 is enough durable against such load from the cam 1 , and as a result, the rocker arm 2 is enough durable in the severely using circumstance of the valve mechanism of the engine, while realizing reduction in weight by using the thin metallic sheet of the body 4 .
Further, since the body 4 is formed with the metallic sheet thinner than the conventional ones, and the axial holes 8 a , 9 a are formed so that the holes 23 a , 24 a are expanded for causing the plastic flow in the thickness of the metallic sheet, an amount of scrapping metal parts is considerably reduced, and accordingly the body 4 of the rocker arm 2 can be heightened in a yield of production.
Another embodiment according to the invention will be explained with reference to FIG. 6 . In the rocker arm 2 according to this embodiment, the thickened portions 10 , 11 of the axial holes 8 a , 9 a of the body 4 are formed to be vertically long elliptical in response to the load when serving the rocker arm 2 . This rocker arm 2 can also perform similar working effects as that of the rocker arm 2 shown in FIGS. 1 to 3 .
A further embodiment according to the invention will be explained with reference to FIG. 7 . In the rocker arm 2 according to this embodiment, the thickened portions 10 , 11 of the axial holes 8 a , 9 a of the body 4 are formed to be semicircular corresponding to a large loading range in response to load when serving the rocker arm 2 . This rocker arm 2 can also perform similar working effects as that of the rocker arm 2 shown in FIGS. 1 to 3 . | A rocker arm includes: a body that is made of sheet metal and includes a pair of side walls; and a pair of axial holes that are respectively formed through the pair of side walls and have a first diameter and through which an axis is inserted. The pair of axial holes include thickened portions formed partially or overall of circumference of the pair of axial holes, and the thickened portion is formed by expanding a hole that has a second diameter smaller than the first diameter and is formed in a pre-arranged range for forming the axial hole in a blank material so as to causing plastic flow in a metallic material of the circumference of the hole. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to earth boring bits of both the fixed cutter and the rolling cutter variety. More specifically, the present invention relates to the cutting structures and cutting elements of such earth boring bits.
2. Description of the Prior Art
Commercially available earth boring bits can generally be divided into the rolling cutter bits, having either steel teeth or tungsten carbide inserts and fixed cutter or drag bits. Modern fixed cutter bits typically utilize either natural diamonds or artificial or man-made diamonds as cutting elements. The diamond containing fixed bits can be generally classified as either steel bodied bits or matrix bits. The steel bodied bits are machined from a steel block and typically have cutting elements which are press-fit into openings provided in the bit face. The matrix bit is formed by coating a hollow tubular steel mandrel in a casting mold with metal bonded hard material, such as tungsten carbide. The casting mold is of a configuration which will give a bit of the desired form. In the past, the cutting elements were typically either polycrystalline diamond compact (PDC) cutters braised within an opening provided in the matrix backing or are thermally stable polycrystalline diamond cutters which are cast within recesses provided in the matrix backing.
The rolling cutter bit employs at least one rolling cone cutter, rotatably mounted thereon. As with the fixed or drag bit, the rolling cutter bit is secured to the lower end of a drill string that is rotated from the surface of the earth. The cutters mounted on the bit roll and slide upon the bottom of the borehole as the drill string is rotated, thereby engaging and disintegrating the formation material.
Despite their generally similar overall function, fixed bits and rolling cutter bits are subjected to different operative forces which dictate fundamental design differences. For example, in the case of rolling cutter bits, the cutters roll and slide along the bottom of the borehole. The cutters, and the shafts on which they are rotatably mounted, are thus subjected to large static loads from the weight on the bit, and large transient or shock loads encountered as the cutters roll and slide along the uneven surface of the bottom of the borehole. Thus, earth boring bits of the rolling cutter variety are typically provided with precision formed journal bearings and bearing surfaces, as well as sealed lubrication systems to increase the drilling life of the bits. The lubrication systems typically are sealed to avoid lubricant lose and to prevent contamination of the bearings by foreign matter such as abrasive particles encountered in the borehole. A pressure compensator system minimizes pressure differential across the seal so that lubricant pressure is equal to or slightly greater than the hydrostatic pressure in the annular space between the bit and the sidewall of the borehole. These features would not normally be present in the fixed cutter or drag bit.
Super-hard materials, including natural and synthetic diamond materials, have been used in fixed cutter or drag type bits for many years. Recently, there has been a general effort to introduce the improved material properties of natural and synthetic diamond type materials into earth boring bits of the rolling cutter variety, as well. However, differences in the forces exerted upon the cutting elements of fixed cutter bits versus bits of the rolling cutter variety come into play. Fixed cutter bits employ the shearing mode of disintegration of the earthen formation almost exclusively. Although diamond and other super-hard materials possess excellent hardness and other material properties, they are generally considered too brittle for most cutting element applications in rolling cutter bits, with an exception being the shear cutting gage insert of such bits. The gage cutters, located on the corner and sidewall of the cutter are subjected to crushing and scraping or shearing actions, while the borehole wall is produced in a pure sliding and scraping (shearing) mode. In the corner and on the sidewall of the borehole, the cutting elements have to do most of the work and are subjected to extreme stresses, which makes them prone to breakdown prematurely and/or wear rapidly.
Recent attempts to introduce diamond and similar materials into rolling cutter bits have relied on a diamond layer or table secured to a substrate or backing material of fracture-tough hard metal, usually cemented tungsten carbide. The substrate is thought to supplement the diamond or super-hard material with its increased toughness, resulting in a cutting element with satisfactory hardness and toughness which diamond alone is not thought to provide.
In addition to the problem of brittleness, diamond inserts of the above general type have presented additional problems, such as the tendency of the diamond or super-hard material to delaminate from the substrate. Several attempts have been made to increase the strength of the interface. U.S. Pat. No. 4,604,106, to Hall et al., discloses a transition layer interface that gradually transitions between the properties of the super-hard material and the substrate material at the interface between them to resist delamination. U.S. Pat. No. 5,544,713, to Dennis, uses an interrupted interface on the metal carbide stud to reduce spalling. U.S. Pat. No. 5,351,772, to Smith, provides a non-planar interface between the diamond table and the substrate. U.S. Pat. No. 5,355,969, to Hardy et al. is another example of a non-planar interface between a super-hard material and the substrate in a PDC drill bit.
Thus, many of the prior art attempts to incorporate diamond or other super-hard materials into the cutting structures of earth boring bits have presented design problems which compromised the overall performance characteristics of the bits.
A need exists, therefore, for earth boring bits having super-hard cutting elements that are relatively easy to manufacture with a satisfactory combination of material properties.
A need also exists for an earth boring bit having wear surfaces, such as the cutting surfaces and cutting elements, with improved properties to extend the useful life of the bit.
Another object of the invention is to provide a earth boring bit having diamond reinforced wear surfaces which surfaces are less brittle and are less likely to delaminate from their substrate than were the prior art materials.
A need also exists for an earth boring bit having cutting elements with a lower coefficient of friction formed by finer diamond starting materials and possessing smoother surfaces than cutting elements of the prior art.
SUMMARY OF THE INVENTION
It is the general object of the present invention to provide an earth boring bit with improved wear-resistant surfaces which extend the useful life of the bit.
Another object of the invention is to provide an earth boring bit which has super-hard cutting elements with satisfactory material properties.
These and other objects of the present invention are achieved by providing an earth boring bit having a bit body with a plurality of wear surfaces. At least selected ones of the wear surfaces incorporate a nanocrystalline diamond material to improve the performance of the wear surface, thereby extending the surface life of the earth boring bit. Preferably, the earth boring bit includes a bit body having an upper extent with means for connection to a drill string for rotation about a longitudinal axis and having a lower extent. A plurality of cutting elements are mounted on the lower extent of the bit body and are adapted to engage an earth formation and cut the earth formation. At least selected ones of the cutting elements incorporate a nanocrystalline diamond material.
In the case of a rolling cone bit having at least one rotatable cone mounted thereon, the rotatable cone has a plurality of cutting elements arranged in circumferential rows thereon. At least selected ones of the cutting elements are formed at least partly of nanocrystalline diamond material. In the case of a fixed cutter bit, the bit body has a plurality of PDC cutting elements mounted thereon. At least selected ones of the cutting elements are formed at least partly of nanocrystalline diamond material.
Additional objects, features and advantages will be apparent in the written description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of an earth boring bit according to the present invention;
FIG. 2 is an elevational view of a nanocrystalline diamond cutting element for the heel or inner-rows of an earth boring bit according to the present invention;
FIG. 3 is an elevation view of a nanocrystalline diamond cutting element for the gage rows of an earth boring bit according to the present invention;
FIGS. 4-6 are simplified, isolated views of various forms of the nanocrystalline diamond cutting elements of the invention showing various forms of the nanocrystalline diamond material attached to a tungsten carbide substrate;
FIGS. 7-9 are simplified, isolated views of chisel type cutting elements showing the application of a layer of nanocrystalline diamond material to the wear surfaces thereof;
FIG. 10 is a side, elevational view of a rotary drag bit featuring cutting elements of the invention;
FIG. 11 is a side, sectional view of the bit of FIG. 10 showing a cutting element attached thereto;
FIG. 12 is a microscopic view of a microcrystalline diamond film applied by a chemical vapor deposition techniques to a silicon substrate; and
FIG. 13 is a microscopic view of a nanocrystalline diamond film applied by chemical vapor deposition techniques to a silicon substrate.
DETAILED DESCRIPTION OF THE INVENTION
Turning to FIG. 1, a rolling cone earth boring bit 11 of the present invention is illustrated. The bit 11 includes a bit body 13, which is threaded at its upper extent 15 for connection into a drill string (not shown) leading to the surface of the well bore. Each leg or section of the bit 11 is provided with a lubricant compensator 17 to adjust or compensate for changes in the pressure or volume of lubricant provided for the bit. At least one nozzle 19 is provided in bit body 13 to spray drilling fluid from within the drill string to cool and lubricate bit 11 during drilling operations. Three cutters 21, 23, 25 are rotatably secured to a bearing shaft associated with each leg of the bit body 13. Each cutter 21, 23, 25 has a cutter shell surface including an outermost or gage surface 31 and a heel surface 41 immediately inward and adjacent the gage surface 31. A plurality of cutting elements, in the form of hard metal, diamond or super-hard inserts, are arranged in generally circumferential rows on each cutter. For example, the bit 11 illustrated in FIG. 1 has gage elements 33 and heel inserts 43 arranged in circumferential rows on each cutter. A scraper element 51 is also secured to the cutter shell surface generally at the intersection of the gage and heel surfaces 31, 41 and generally intermediate a pair of heel inserts 43.
The outer cutting structure, comprising heel cutting elements 43, gage cutting elements 33 and a secondary cutting structure in the form of chisel-shaped trimmer or scrapper elements 51 combine and cooperate to crush and scrap formation material at the corner and sidewall of the borehole as cutters 21, 23, 25 roll and slide over the formation material during drilling operations. According to the preferred embodiment of the present invention, at least one, and preferably several, of the cutting elements in one or more of the rows is formed at least partly of a nanocrystalline diamond material.
FIG. 2 is an elevational view, partially in section, of a nanocrystalline diamond cutting element 51 according to the present invention. Cutting element 51 comprises a generally cylindrical base 53 which is secured in an aperture or socket in the cutter by interference fit or brazing. Cutting element 51 is a chisel-shaped cutting element that includes a pair of flanks 55 that converge to define a crest 57. Chisel-shaped cutting elements are particularly adapted for use as the trimmer elements (51 in FIG. 1), a heel element (43 in FIG. 1) or other inner-row cutting elements. A chisel-shaped element is illustrated as an exemplary trimmer, heel or inner-row cutting element. Other conventional shapes, such as ovoids, cones, or rounds are contemplated by the present invention, as well.
FIG. 3 is an elevational view, partially in section, of a nanocrystalline diamond gage row insert 33 according to the present invention. Gage row insert 33 comprises a generally cylindrical body 35 which is provided at the cutting end with a chamfer 37 that defines a generally frusto-conical cutting surface. The intersection between cutting surface 37 and flat top 39 defines a cutting edge for shearing engagement with the sidewall of the borehole.
Both the chisel-shaped element 51 and the gage insert 33 are formed at least in part of a super-hard material which, in the case of the present invention, is a nanocrystalline diamond material. The super-hard nanocrystalline diamond material will have a hardness in excess of 3500-5000 on the Knoop scale and is to be distinguished from merely hard ceramics, such as silicon carbide, tungsten carbide, and the like. Most nanocrystalline materials are in the range from about 10 to 100 nanometers. All materials in this size range are referred to herein as "nano" materials as distinguished from submicron materials.
Until recent years, only two crystalline forms of carbon were known to exist, graphite and diamond. Recently, a third form of carbon in polygonal arrangement of hexagonal and pentagonal faces has been characterized by Dr. Richard Smalley of Rice University in Texas. Dr. Smalley discovered that the carbon molecule formed a geodesic sphere similar to a soccer ball. In addition, he discovered that these structures of carbon contain anywhere from 32 atoms of carbon to hundreds of carbon atoms including C 60 , C 70 , C 76 , C 84 , C 90 and C 94 , with C 60 predominating. These molecules are referred to as "Buckminsterfullerenes" or "fullerenes" due to their geodesic shape and are sometimes referred to informally as "buckyballs." The three dimensional shape of these molecules gives them unique physical and chemical properties. The sphere shape provides the molecules with a high resistance to compressibility with a hardness which has been estimated to be near that of diamond.
More recent technology has made it possible to convert "buckyballs" to diamond using, for example, a high pressure, high temperature apparatus (HPHT). Other techniques also exist, for example, in January, 1992, a French team at the Center For Very Low Temperature Research, Grenoble, France, succeeded in converting C 60 to diamond in a high pressure apparatus at approximately room temperature. The C 60 powder was compressed in a diamond anvil cell. The diamond anvils in the cell are slightly slanted relative to each other, resulting in a considerable pressure gradient across the cell. The material retrieved from the cell after compression is a polycrystalline powder, confirmed as diamond by X-ray and electron diffraction analysis.
The price of a gram of commercially available mixed fullerenes has recently dropped from around $1,200.00 per gram to below about $50.00 per gram making these materials more commercially feasible for industrial applications. Such mixed fullerenes can be obtained commercially from Texas Fullerenes of Houston, Tex.; Materials And Electrochemical Research Corporation of Tucson, Ariz., Bucky U.S.A. of Bellaire, Tex., and others. The purity of the mixed fullerenes varies from about 92% C 60 to 98% C 60 with the balance being higher molecular weight fullerenes. Other versions of nanocrystalline diamond material are contemplated, as well. The fullerene starting materials of the invention are preferably at least about 95% C 60 , most preferably at least about 98% C 60 .
The nanocrystalline diamond materials of the invention are typically formed at high pressure and temperature conditions under which the materials are thermodynamically stable using conventional PDC technology known by those skilled in the art. For example, an insert may be made by forming a refractory metal container or can to the desired shape, and then filling the can with buckyball powder to which a small amount of metal material (commonly cobalt, nickel or iron) has been added. The container is then sealed to prevent any contamination. Next, the sealed can is surrounded by a pressure transmitting material which is generally salt, boron nitride, graphite or similar material. This assembly is then loaded into a high pressure and temperature cell. The design of the cell is dependent upon the type of high pressure apparatus being used. The cell is compressed until the desired pressure is reached and then heat is supplied via a graphite-tube electric resistance heater. Temperatures in excess of 1350° C. and pressures in excess of 50 kilobars may be employed. At these conditions, the added metal is molten and acts as a reactive liquid phase to enhance sintering of the buckyball material. After a few minutes, the conditions are reduced to room temperature and pressure. The insert is then broken out of the cell and can be finished to final dimensions through grinding or shaping.
In the typical PDC manufacturing method using the high pressure, high temperature (HPHT) apparatus, the high temperature and pressure conditions cause the cobalt binder to become liquid and to move from the substrate into the diamond causing diamond-to-diamond bonding to occur. Consequently, the diamond attaches itself to the carbide substrate. This procedure creates high residual stresses in the part, however, which can lead to premature failure. By substituting fullerenes or other nanocrystalline starting materials as the carbon source, the carbon material can be converted to diamond at lower pressure and temperatures than graphite in an HPHT apparatus.
Other techniques are known in the art for providing nanophase diamond layers and films including the use of nanocrystalline starting materials other than "buckyballs." For example, see U.S. Pat. No. 5,478,650, issued Dec. 26, 1995, to Davanloo et al. which teaches the production of nanometer scale nodules of diamond bonded carbon structures. The nanophase diamond films have diamond-like properties indicating a preponderance of sp 3 bonds within the nodules and a substantial absence of hydrogen and graphite within the nodules. The nanophase diamond films can be created to have a hardness exceeding that of natural diamond, depending on the quantity of graphite left in the voids between the nodules. The nanophase diamond films are characterized by a low coefficient of friction and by a low average internal stress.
In the Davanloo process, a moving sheet of hardened graphite foil is placed within a vacuum chamber with the chamber being evacuated and a laser beam being directed at an angle upon the graphite foil to obtain a plume of carbon substantially void of macroscopic particles having dimensions generally greater than 1 micron. A substrate is positioned in the chamber and an electrical field is disposed within the path of the laser beam between the substrate and the target. A portion of the plume is collected at selective points upon the substrate in accordance with the electrical field at a deposition rate greater than 0.1 microns per hour, more typically about 0.5 microns per hour.
Another technique for creating a nanocrystalline diamond material of the type useful for the purposes of the present invention has been developed by Diamond Partnership, Argonne National Lab, Argonne, Ill. In that procedure, films are produced of nanocrystalline diamond with 20 to 50 nanometers RMP roughness, independent of film thickness. They have an average grain size of 15 nm. The process employed uses either C 60 fullerenes or buckyballs or a hydrocarbon such as methane as the carbon source in an inert gas plasma to produce the carbon dimer C 2 , which acts as the growth species. Uniform growth and good adhesion has been demonstrated for silicon, silicon carbide, silicon nitride, tungsten and tungsten carbide substrates.
Chemical vapor deposition processes can also be used to apply the nanocrystalline diamond materials of the invention directly to a substrate. Chemical vapor deposition, as its name implies, involves a gas-phase chemical reaction occurring above a solid surface, which causes deposition onto that surface. CVD techniques for producing diamond films require a means of activating gas-phase carbon-containing precursor molecules. This generally involves thermal or plasma activation, or the use of a combustion flame. Growth of diamond normally requires that the substrate be maintained at a temperature in the range from about 1,000-1,400° K and that the precursor gas be diluted in an excess of hydrogen. The fact that diamond films can be formed by the CVD technique is linked to the presence of hydrogen atoms, which are generated as a result of the gas being "activated", either thermally or via electron bombardment. FIGS. 12 and 13 are SEM photomicrographs made by Dr. Paul May, School of Chemistry, University of Bristol, United Kingdom. In order to differentiate the prior art microcrystalline films from the nanocrystalline films of the invention, FIG. 12 shows the surface morphology obtained by the CVD deposition of a microcrystalline diamond film upon a silicon substrate. The film is polycrystalline, with facets appearing both as square and rectangular forms. FIG. 13 illustrates a nanocrystalline film of the invention which exhibits the "cauliflower" morphology typical of such materials. The nanocrystalline film is much smoother than the microcrystalline film allowing for the production of PDC parts with a significantly finer finish than conventionally made PDC parts.
A CVD technique for depositing ultra fine grained polycrystalline diamond films is disclosed in U.S. Pat. No. 5,425,965, issued Jun. 20, 1995, to Tamor et al. Diamond nucleation is enhanced by ultrasonic treatment of the substrate surface with a fluid which consists essentially of unsaturated oxygen-free hydrocarbons and diamond grit. Another article describing the application of diamond films generally using CVD techniques is "CVD Diamond-A New Technology For The Future", May, Endeavor Magazine, (1995), pp. 101-106.
In addition to the previously described techniques, including the conversion of fullerenes and vapor deposition of nanocrystalline diamond materials directly to an insert, other techniques may be employed as well. These techniques include the treating of a vapor coated insert in an HPHT apparatus to improve bonding; sintering of nanocrystalline diamond powder in an HPHT apparatus directly to the carbide element; layering of the nanocrystalline diamond on the surface with a conventional PDC layer underneath and between the nanocrystalline diamond and the carbide to create an especially wear-resistant surface and a courser, tougher intermediate diamond layer; vapor coating of a PDC coated insert with a nanocrystalline diamond film; and combinations of the above techniques.
According to one embodiment of the present invention, at least the cutting surfaces of elements 51, 33 are formed entirely of nanocrystalline diamond material. It will be understood, however, that all of the nanocrystalline diamond materials of the invention can contain at least traces of other materials such as the cobalt binder used in traditional polycrystalline diamond manufacturing techniques.
It may be desirable to provide a cutting element having a cutting end or surface which is formed entirely of nanocrystalline diamond material with a portion of the element formed of a less wear-resistant and more easily formed material. For example, FIG. 4 shows a cutting element 59 having a cylindrical body 61 formed of cemented tungsten carbide and a cutting surface or end 63 which is formed entirely of nanocrystalline diamond material. In FIG. 5, a cutting element 65 is shown having a cutting end with a layer of coarser or seed diamonds 67 sandwiched between an outer and inner layer 69, 71 of nanocrystalline diamond material. By "coarser" diamond layer is meant a layer made up of, e.g., microcrystalline diamond material. FIG. 6 shows a cutting element 73 in which the cutting end 75 includes coarser diamonds 77 interspersed with fullerene material 79. FIGS. 7-9 show chisel-shaped cutting elements 81, 83, 85, each of which includes a nanocrystalline diamond layer 87, 89, 91, respectively, applied to a wear surface thereof, as by chemical vapor deposition techniques.
FIGS. 10 and 11 illustrate a rotary drag bit 10 manufactured in accordance with the present invention. The fixed cutter bit 10 has a face 12 including waterways 13 at a distal end 14 and a connector 16 at a proximal end 18. A plurality of cutting elements 20 are attached to the face 12 oriented to cut a subterranean formation during rotation of the bit 10. The bit 10 also has a plurality of junk slots 22 on the face 12 so that drilling fluid and formation cuttings may flow up through the junk slots 22 and into the borehole (not shown) Generally the junk slots 22 are defined by a recessed portion 23 and a raised portion or gage pad 25 that may optionally contain one or more cutting elements 20.
Referring to FIG. 11, a perspective view of a cutting element 20 with a sectional view of the face 12 of the bit of FIG. 10 is illustrated. The cutting element 20 has a cutting face or surface 21 formed of the nanocrystalline diamond material which is bonded to and supported by a substrate 26. The cutting element 20 is then attached to the bit face 12 by methods known in the art (e.g., brazing) so that approximately 1/2 of the cutting face 21 is exposed above the face 12. Typically, the cutting elements are located adjacent a waterway 13 on the bit face or junk slot 22 so that formation chips generated during the drilling process may flow up through the recessed portion 23 and into the borehole (not shown).
A earth boring bit according to the present invention posses a number of advantages. A primary advantage is that the earth bore bit is provided with more efficient and durable cutting elements. Some time and temperature are needed in the HPHT process using a nanocrystalline starting material to allow the diamonds to bond to each other and to the substrate; however, the time will be relatively minimal which will reduce internal stresses. Due to the nano-size of the starting materials, more diamonds will be in contact with the formation being drilled, thereby improving penetration rates and longevity of PDC bits. In addition, the PDC parts of the invention have a significantly finer finish than conventionally made PDC parts. The finer finish helps to reduce post HPHT lapping, thereby reducing manufacturing costs. The finer finish and resulting lower coefficient of friction of the cutting elements produced helps prevent a drilled formation from sticking to the parts, further improving penetration rates. The size of the nanocrystalline diamond material lends itself more readily to producing different geometries with less internal stresses compared to conventional diamond materials either in whole or in combination in PDC parts.
While the invention has been described with reference to preferred embodiments thereof, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit thereof. | An earth boring bit is shown of the type used to drill subterranean formations. The bit body has an upper extent which is threaded for connection in a drill string extending to the earth's surface. A lower extent of the bit body has a number of cutting elements mounted thereon which engage an earthen formation and cut the formation. At least selected ones of the cutting elements incorporate a nanocrystalline diamond material. | 4 |
[0001] This application relates generally to methods of embedding digital watermarks in printed halftone images, and more particularly, to a method for embedding color digital watermarks in printed halftone images.
BACKGROUND & SUMMARY
[0002] Watermarks have long been used in the printing industry to identify the source or origin of a document. Generally, a watermark appears as a faint pattern in an image, which is visible only when the original document is viewed in a particular manner. Unless a counterfeiter had access to the watermarked paper, it would be difficult for him to reproduce the document without showing its inauthenticity. That is to say, without the paper on which the original image was originally printed, the copy should be readily detectable. However, as people move away from the use of watermarked papers for cost and other practical reasons, it is still necessary to identify the source or origin of a document image.
[0003] The introduction of the plain paper copier has resulted in a proliferation of paper copies of paper originals. A similar result is happening to electronic images, given the easy availability of digital scanners and quick and widespread access to images throughout the Internet. It is now very difficult for the creator of an image to generate an electronic original, for which he can be assured that illegal copies will not be spread to third parties. The use of a digital watermark is a technology that aims to prevent that spread, by incorporating an identifying mark within an image that allows one to identify the source of the image in an electronic copy. It is important that the identifying mark not be disturbing or distracting to the original content of the image, while at the same time, allowing easy identification of the source. The watermarks could be added either by the scanner, as or after the image is acquired, or by the halftoning software.
[0004] Watermark identification may be accomplished by embedding a digital watermark in a digital or printed page that will identify the owner of rights to the image. Watermarking can take two basic forms, visible or perceptible, and invisible or imperceptible. Visible watermarks are marks such as copyright logos or symbols or logos that are imprinted into the digital or printed image to be distributed. The presence of the watermark is made clearly visible in the image or rendered document in a way that makes it difficult to remove without damaging the image or document. The presence of the visible watermark does not harm the usefulness of the image, but it deters the use of the image without permission. However, visible watermarks may interfere with the use of the image or with the image aesthetics. The visible watermark is also a potential target for fraud, in that it is possible for a fraudulent copier of the image to identify the location of the watermark and attempt to reproduce the image without the watermark or try to transfer the watermark to another image.
[0005] Invisible watermarks are marks such as copyright symbols, logos, serial numbers, other identifiers, etc. that are embedded into digital or printed images in a way which is not easily discernible or perceptible by the unaided eye. At a later time, the information embedded in these watermarks can be derived or “retrieved” from the images to aid identification of the source of the image, including the owner and the individual to whom the image is sold. Such watermarks are useful for establishing ownership when ownership of an image is in dispute. They would be less likely to be useful as a deterrent to the theft of the image. While either or both visible or invisible watermarks are desirable in an image, they represent different techniques for either preventing copying or detecting copying. It is anticipated that document producers may wish to use both kinds of protection.
[0006] Embedded watermarks in printed halftone images, which can subsequently be detected using a visual aid or using a watermark detection algorithm on a scan of the image are of interest in wide range of applications. U.S. Pat. No. 5,790,703 to Shen-ge Wang for “Digital Watermarking Using Conjugate Halftone Screens,” describes a method for generating watermarks in black and white halftone printing using stochastic screens. In U.S. Pat. No. 5,790,703, monochrome digital watermarks are embedded as correlations in the halftone screen. U.S. Pat. No. 6,731,409 to Shen-ge Wang for “System and Method for Generating Color Digital Watermarks Using Conjugate Halftone Screens” extends the method of U.S. Pat. No. 5,790,703 to color printing. The method disclosed in U.S. Pat. No. 6,731,409 generates color watermarks by producing a halftone pattern in one or more color separations of the color document using a separate halftone screen for each separation. While the color contrast watermarks produced by U.S. Pat. No. 6,731,409 work well on digital bit-maps, the color watermarks are harder to detect in printed hardcopy. The contrast and signal-to-noise ratio of the color watermark produced can be quite weak because of screen interactions making it impractical for high resolution color printing applications. It is also harder to determine the shift required for performing a watermark estimation when detecting the watermark pattern in scanned images due to the use of different screens for the different color separations. What is needed is a method of generating color watermarks having good contrast and good signal-to-noise ratios for detection on scans of printed images.
[0007] Disclosed in embodiments herein is a method for generating color digital watermarks, which provides good contrast while maintaining good signal-to-noise ratios. Instead of using a separate screen for each separation, the method uses a single halftone screen for all color separations. In one embodiment, the method uses a stochastic halftone screen with an embedded watermark, i.e., a stochastic screen with a conjugate relationship to describe the location of the watermark. The conjugate relationship determines the placement or location of the dots corresponding to the digital watermark. A successive fill technique, such as the one described in U.S. Pat. No. 6,844,941 to G. Sharma et al. for Color Halftoning Using a Single Successive-Filling Halftone Screen, the contents of which are incorporated herein by reference in their entirety, may be used to color the dots forming the digital watermark within the halftone screen. For example, if an image has four separations, the successive fill technique will determine whether to color a particular dot black, cyan, magenta, yellow or not at all. By using a single halftone screen and a successive fill technique, the different separations work together to produce the watermark with a significantly higher signal to noise ratio. In addition, the use of a single screen significantly improves the synchronization for the watermark detection process.
[0008] For purposes of this disclosure, the term “screening” or “halftoning” refers to the process in which each pixel value of a 2D array of contone pixels is compared to one of a set of preselected thresholds (the thresholds may be stored as a 2D matrix and the repetitive pattern generated by this matrix is considered a halftone cell), which produces a binary output at each pixel according to the result of the comparison. The matrix of threshold values is often referred to as a “screen”, and the process of generating the binary image from the contone image using the screen is called “screening” or halftoning.
[0009] Also disclosed herein is a method for generating an authenticable color image, the color image including a plurality of color separations, wherein an authenticable image inserted in the color image is not readily visually perceptible. According to one embodiment, the method includes providing a single halftone screen, wherein the single halftone screen comprises a plurality of pixel locations with associated threshold values; wherein the halftone screen has a plurality of cells, each cell having a first region and a second region, each cell being spatially offset from a neighboring cell by a first distance; wherein a first region of a first cell is substantially identical to a first region of a second cell, and a second region of the first cell is substantially conjugate to a second region of the second cell; halftoning image data corresponding to a first color separation using the single halftone screen, wherein a corresponding first set of screen pixel locations associated with a first set of threshold values are filled by the first color separation; halftoning image data corresponding to a second color separation using the single halftone screen, wherein a corresponding second set of screen pixel locations are filled by the second separation, the second set having threshold values successive to the first set of threshold values. When a first copy of the color image is spatially offset from a second copy of the color image by at least the first distance, at least a first cell of each of the first and second copy of the color image align with at least a second cell of the first and second copy of the color image, and contrast of the identical and conjugate regions become visible to form the authentication image. The single halftone screen may be a stochastic screen.
[0010] The method can be expanded to cover placement and coloring of the third and fourth color separations. The method may further include halftoning image data corresponding to a third color separation using the single halftone screen, wherein a corresponding third set of screen pixel locations are filled by the third separation, the third set having threshold values successive to the second set of threshold values. For a fourth color separation, the method may further include halftoning image data corresponding to a fourth color separation using the single halftone screen, wherein a corresponding fourth set of screen pixel locations are filled by the fourth separation, the fourth set having threshold values successive to the third set of threshold values. The color separations may be black, magenta, cyan and yellow.
[0011] Further disclosed is a method for generating an authenticable color image, the color image including a plurality of color separations, wherein an authenticable image inserted in the color image is not readily visually perceptible. The embodiment includes providing a single stochastic halftone screen, the single stochastic halftone screen comprises a plurality of pixel locations with associated threshold values; wherein the stochastic halftone screen has a plurality of cells, each cell having a first region and a second region, each cell being spatially offset from a neighboring cell by a first distance; wherein a first region of a first cell is substantially identical to a first region of a second cell, and a second region of the first cell is substantially conjugate to a second region of the second cell; halftoning image data corresponding to the plurality of color separations using the stochastic halftone screen; further comprising, for each pixel, summing image values corresponding to the plurality of color separations in a predetermined order; comparing sums image values of at least the first and second color separations to the threshold values in the stochastic halftone screen; determining placement and color of the pixel in accordance with a predetermined relationship based on the comparison; wherein, when a first copy of the color image is spatially offset from a second copy of the color image by at least the first distance, at least a first cell of each of the first and second copy of the color image align with at least a second cell of the first and second copy of the color image, and contrast of the identical and conjugate regions become visible to form the authentication image.
[0012] For two separations, the predetermined relationship may be: if (i1>screen_threshold), printing a pixel with the colorant of the first separation; if ((i1+i2)>screen_threshold) and (i1<screen_threshold)), printing a pixel with the colorant of the second separation; and if ((i1+i2−M)>screen_threshold), printing a pixel with the colorant of the second separation; where i1, i2 are the image values of the image data for the first color separation and the second color separation, respectively, screen_threshold is the value of a threshold in the stochastic halftone screen, and M is the maximum threshold value. Note that with the use of this method a given pixel may be printed with none, one, or both of the colorants. The predetermined relationship may be extended to a third separation and include: if ((i1+i2+i3)>screen_threshold) and ((i1+i2)<screen_threshold)), printing a pixel with the colorant of the third separation; if ((i1+i2+i3−M)>screen_threshold) and ((i1+i2−M)<screen_threshold), printing a pixel with the colorant of the third separation; and if ((i1+i2+i3−M)>screen_threshold), printing a pixel with the colorant of the third separation.
[0013] A method for generating an authenticable color image, the color image including a plurality of color separations, wherein an authentication image inserted in the color image is not readily visually perceptible, according to another embodiment of the method for generating an authenticable color image, includes halftoning image data corresponding to a first color separation using a single halftone screen, wherein the single halftone screen includes means for generating an authentication image in a color image; and halftoning image data corresponding to a second color separation using the single halftone screen and dot placement information for the image data corresponding to the first color separation to form a multicolor image; wherein halftoning of image data corresponding to the second color separation includes placing dots for the second color separation in thresholds of the halftone screen relative to those thresholds occupied by the first color separation in the halftone screen in accordance with a predetermined relationship.
[0014] Examples of predetermined relationships include: placing thresholds for the second color separation adjacent to the thresholds of the first color separation, placing thresholds for the second color separation at a predetermined distance from the thresholds of the first color separation, and generating a modified value for the second separation by adding the “halftone error” from the first separation and obtaining the second separation by screening the modified value for this separation. For example, halftoning of image data corresponding to the second color separation may include placing halftone dots for the second color separation in thresholds of the stochastic halftone screen determined by: determining a halftone error between the first color separation image data and the second color separation image data; and adding the halftone error to the second color separation image data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates a “conjugate” pair of binary patterns generated using a monochrome conjugate halftone screen;
[0016] FIG. 2 illustrates the output of overlaying the two halftone images shown in FIG. 1 ;
[0017] FIG. 3 illustrates the output of overlaying two identical halftone images, shown as the left hand pattern of FIG. 1 ;
[0018] FIG. 4 illustrates the output of overlaying two halftone images generated by the pair of halftone screens described in Table 2;
[0019] FIG. 5 illustrates the output of overlaying two halftone images generated by the pair of halftone screens described in Table 3;
[0020] FIG. 6 illustrates the result of combining the output of FIG. 4 in cyan and the output of FIG. 5 in magenta;
[0021] FIG. 7 illustrates the result of combining in yellow and blue (left) and red and green (right);
[0022] FIG. 8 illustrates halftone images generated by an input with CMYK values K=C=M=Y=32 and the screens shown in Table 2, using successive-filling in colorant order K, M, Y, C;
[0023] FIG. 9 illustrates the output of overlaying the two halftone images in FIG. 8 ;
[0024] FIG. 10 illustrates a watermark to be included into an image; and
[0025] FIG. 11 illustrates a bias tile incorporating the watermark of FIG. 10 .
DETAILED DESCRIPTION
[0026] One embodiment of a method for generating an authenticable color image allows for a color pattern to be used on a color document, where the color pattern can be generated using a stochastic halftoning process to produce a desirable image. Using such techniques, the random nature of the stochastic screen affords the opportunity to include a unique authentication procedure in conjunction with correlations between different stochastic screens. As a primer to the principles of color stochastic halftone screening, monochrome stochastic halftone screening is discussed below. In various exemplary embodiments, this method for generating an authenticable color image uses the stochastic screening method described in U.S. Pat. No. 5,673,121 to Wang, hereby incorporated by reference in its entirety.
[0027] Each location in an image may be called a “pixel” or “dot”. In an array defining an image in which each item of data or image signal provides a value, each value indicating the color of a location may be called a “pixel value” or “dot value”. In monochrome stochastic halftone screening of monochromatic documents, halftone images are generated from constant gray-scale inputs by a screen matrix with N elements. If the overlap between adjacent pixels is ignored, a screen cell with n black pixels and N−n white pixels simulates the input with a gray scale (g) equal to
[0000] g =( N−n )/ N,
[0000] where 0≦n≦N, or 0≦g<1. The visual appearance of this pattern depends on whether the black pixels or the white pixels are minorities. If the black pixels are minorities, for example, 0.5≦g≦1.0, the best visual appearance of the halftone pattern occurs when all black pixels are “evenly” distributed, in other words, each black pixel should “occupy” 1/n, or 1/(1−g)N, fraction of the total area of the screen. Therefore, the average distance of adjacent black pixels should be equal to α(1−g) −1/2 , where α is independent of gray levels. On the other hand, if the white pixels are minorities, i.e., 0≦g≦0.5, each white pixel should “occupy” 1/(N−n) or 1/gN, fraction of the total area and the average distance of adjacent white pixels should be equal to αg −1/2 . An idealized stochastic dithering screen is defined as a threshold mask generating halftone images, which satisfy the above criterion for all gray levels.
[0028] In general, input gray-scale images are specified by integer numbers, G(x, y), where 0≦G≦M. As a result, the dithering screen should have M different threshold values spanning from zero to M−1. Moreover, at each level, there should be (N/M) elements having the same threshold value T. The ultimate goal of designing a stochastic screen is to distribute the threshold values T so that the resulting halftone images are as close as possible to the ones generated by an idealized stochastic screen.
[0029] Choosing an arbitrary pair of pixels from the dithering screen, it is assumed that the threshold values for these two pixels should be T 1 =T(x 1 , y 1 ) and T 2 =T(x 2 , y 2 ), respectively, where (x 1 , y 1 ) and (x 2 , y 2 ), are the coordinates of these pixels. As the result of dithering a constant input G, the outputs B 1 =B(x 1 , y 1 ) and B 2 =B(x 2 , y 2 ) have the following possible combinations:
B 1 =1 and B 2 =1, if G≧T 1 and G≧T 2 ; B 1 =0 and B 2 =0, if G<T 1 and G<T 2 ; B 1 ≠B 2 ,
where B=1 represents a white spot and B=0 represents a black spot for printing. When one output pixel is black and another is white, the distance between these two pixels is irrelevant to the visual appearance for the reasons outlined above. When both pixels are white, the visual appearance under the following case must be considered:
If M/2≧G, G≧T 1 , and G≧T 2 .
[0034] In this case, both output pixels are white, and white spots are minorities. Therefore, the corresponding distance between (x 1 , y 1 ) and (x 2 , y 2 ) is relevant to the visual appearance of the halftone images. According to the analysis outlined above, this distance is greater or equal to αg −1/2 , or α(G/M) −1/2 , for outputs of an idealized stochastic screen. Among all G under this case, the critical case of G is the smallest one, or G c =Max(T 1 , T 2 ), which requires the largest distance between the two pixels (x 1 , y 1 ) and (x 2 , y 2 ).
[0035] Similarly, when both dots or pixels appear as black dots or pixels, the visual appearance under the following case must be considered:
If G≧M/2, G<T 1 and G<T 2 .
Among all G under this case, the largest G is given by G c =Min(T 1 ,T 2 ), which requires the largest distance α(1−G c /M) −1/2 between (x 1 , y 1 ) and (x 2 , y 2 ).
[0037] Mathematically, a merit function q(T 2 , T 2 ) can be used to evaluate the difference between the idealized stochastic screen and the chosen one. For example, the following choice (Eq. 1) may be used:
[0000] q ( T 1 ,T 2 )=exp( Cd 2 /d c 2 ), (1)
[0000] where
d 2 =(x 1 −x 2 ) 2 +(y 1 −y 2 ) 2 ; d c 2 =M/[M−Min(T 1 , T 2 )], if T 2 >M/2 and T 1 >M/2, d c 2 =M/Max(T 1 , T 2 ), if T 2 ≦M/2 and T 1 ≦M/2, d c 2 =0, i.e., q=0, elsewhere; and C is a constant.
[0043] Since a dithering screen is used repeatedly for halftoning images larger than the screen, for any chosen pair of pixels from the dithering screen, the closest spatial distance in corresponding halftone images depends on the dithering method and should be used for the merit function. The overall merit function should include contributions of all possible combinations. In an experiment, the summation of q(T 1 , T 2 ) was for optimization, i.e.:
[0000] Q=Σq ( T 1 ,T 2 ), (2)
[0000] where Σ for all (x i , y 1)≠(x 2 , y 2 ).
[0044] The design of stochastic screens then becomes a typical optimization problem. When the threshold values of a chosen screen are rearranged, the merit function can be evaluated to determine the directions and steps. Many existing optimization techniques can be applied to this approach. The simplest method is to randomly choose a pair of pixels and swap threshold values to see if the overall merit function Q is reduced. Since only those Q values related to the swapped pair need to be recalculation, the evaluation of Q does not consume significant computation time. All initial threshold values were randomly chosen by a standard random number generator.
[0045] Alternatively, the threshold assignments from an existing screen may be used. Besides the Gaussian function described by Eq. (1) as the merit function, other functions were tested, such as the Butterworth function and its Fourier transform. Other optimization functions are possible. For each iteration, a pair of pixels was randomly chosen from the dithering screen, their threshold values swapped and the change of the merit function Q was calculated. If Q is not reduced, the threshold values are restored. Otherwise, the next iteration is performed. The optimization process continues until a satisfied distribution of threshold values is achieved.
[0046] The issues discussed above regarding monochrome stochastic screens can be developed to produce an invisible color watermark in a halftoned color document in accordance with various exemplary embodiments of the stochastic halftone screening methods according to this method for generating an authenticable color image.
[0047] U.S. Pat. No. 5,790,703 describes a method for generating watermarks in black and white halftone printing using conjugate stochastic screens, and is incorporated herein by reference in its entirety. Two screens, T 1 (x, y) and T 2 (x, y), having the same size and the same shape, are conjugate, if for all elements (x, y) the corresponding pair of threshold values have the following relation (Eq. 3):
[0000] T 1 ( x,y )+ T 2 ( x,y )= M, (3)
[0000] where M is the number of total possible levels. By the thresholding rule, which defines the binary status of the output B(x, y) based on the relation between an input value G(x, y) and the threshold value T(x, y) provides:
B(x, y)=1, if G(x, y)≧T(x, y); B(x, y)=0, if G(x, y)<T(x, y).
It is interesting to notice that if the input image has a constant value, G(x, y)=M/2, the two binary outputs B 1 (x, y) and B 2 (x, y), generated by two conjugated screens T 1 (x, y) and T 2 (x, y) in Eq. 3, are exactly binary complement for all pixels. In other words, any black pixel of B 1 has a corresponding white pixel of B 2 at the same pixel location (x, y), and vice versa. If the input level G(x, y)<M/2, the binary complement relation between B 1 and B 2 is still true for all white spots, as minorities in this case. If G(x, y)>M/2, the binary complement relation between B 1 and B 2 is true for all black spots, also as minorities in this case.
[0050] From the previous discussion on stochastic screens, it is not difficult to see that the conjugate screen T 2 (x, y), of a well-designed stochastic screen T 1 (x, y), is also a well-designed stochastic screen, because for every output level of T 2 there is a corresponding level of T 1 , which is optimized during the screen design process. The principal difference is that if the level of T 1 is with black minorities, the corresponding level of T 2 is with white minorities, and similarly so for T 1 with white minorities. Consider the following two cases:
[0051] In a first example, two identical halftone images are generated using a stochastic screen T 1 (x, y) and printed on two transparencies, respectively. If the two transparencies are laid over each other and viewed in a show-through mode, the overall appearance depends on the relative position between the two halftone images. The maximal, or the brightest, show-through can be obtained only with a perfect pixel-to-pixel alignment of the two images without any lateral shift or rotation. It should be appreciated that this statement is an analogue of a two-dimensional auto-correlation of the halftone image. The maximal show-through corresponds to the peak value of the auto-correlation, or in other words, the positive peak of the correlation.
[0052] In another example, two halftone images are generated by two conjugated stochastic screens, T 1 (x, y) and T 2 (x, y) defined by Eq. 3, respectively. The cross-correlation between the two halftone images, generated by two conjugated screens, behaves opposite to the auto-correlation described above such that, after the two halftone images are laid over each other and perfectly aligned, the overall appearance reaches the minimal, or the darkest, show-through. Mathematically, this corresponds to a negative peak of the cross-correlation, or simply, the negative peak of the correlation.
[0053] These two examples can be relatively combined so that some portions of the second halftone image are generated by using the conjugate screen T 2 (x, y) while the remaining portion of the second image are generated by the same stochastic screen T 1 (x, y), as used to generate the first halftone image. Laying a transparency of the second image over the first one, a strong contrast occurs between the brightest and the darkest show-through.
[0054] Practically, combining the two portions of the second halftone image described above can be realized by designing a new stochastic screen T 2 (x, y), which has the same shape and size as the first stochastic screen T 1 (x, y). A portion of the new stochastic screen T 2 is made conjugate to the corresponding portion of the first stochastic screen T 1 while other portion of the new stochastic screen T 2 is made identical to a portion of the first stochastic screen T 1 . By modifying the optimization condition for stochastic-screen design as described, for example, in U.S. Pat. No. 5,673,121, it is possible to make the boundary between the two portions of by the second screen visually seamless. Therefore, the halftone images generated by the new stochastic screen T 2 appear just as good as halftone images generated by the first stochastic screen T 1 . Although the watermark, defined by the shape of the portion for the conjugate relation, is visually imperceptible, the information is hidden, or incorporated into the halftone images generated by the stochastic screen in a manner according to the degree of correlation.
[0055] A concrete example of the monochrome technique described in U.S. Pat. No. 5,790,703 will be described: Define two conjugate halftone screens as two thresholding masks having identical shape and size and satisfying such conjugate relation that T1(i, j)=255−T2(i, j) for all corresponding pixels (i, j), where T1 and T2 are the thresholding values of the two masks, respectively. An exemplary pair of conjugate halftone screens is shown in Table 1 (note that the halftone screens in Table 1 can be considered two halftone cells of a single halftone screen). Note that the sum of two values in any pair of corresponding pixels shown in Table 1 is 255.
[0000]
TABLE 1
A pair of conjugate halftone screen cells.
1
172
24
232
80
168
254
83
231
23
175
87
228
88
154
104
208
40
27
167
101
151
47
215
32
200
56
36
8
252
223
55
199
219
247
3
219
116
240
137
188
16
36
139
15
118
67
239
65
160
103
209
72
138
190
95
152
46
183
117
202
125
172
96
248
40
53
130
83
159
7
215
[0056] If an input with a constant level 128 is halftoned by the conjugate screen cells shown in Table 1, the result will be a “conjugate” pair of binary patterns 110 A, 110 B as shown in FIG. 1 . By overlaying the two binary patterns in FIG. 1 , it is possible to obtain a complete black pattern as shown in FIG. 2 . On the other hand, if two identical halftone patterns are overlaid together, the output is exactly the same binary pattern as the overlaid patterns. For example, FIG. 3 shows the result of overlaying two identical patterns as the left binary image in FIG. 1 .
[0057] Consider the pair of halftone screen cells, as shown in Table 2, with the upper three rows (a first region of a first halftone cell and a first region of the second halftone cell) of the two screens/cells are conjugate while the lower three rows (a second region of the first halftone cell and a second region of the second halftone cell) are identical.
[0000]
TABLE 2
A pair of halftone screens, with a conjugate upper half and an identical lower half.
The overlaying of two binary patterns generated by these two screens and
a constant input 128 will appear as the pattern shown in FIG. 4.
1
172
24
232
80
168
254
83
231
23
175
87
228
88
154
104
208
40
27
167
101
151
47
215
32
200
56
36
8
252
223
55
199
219
247
3
219
116
240
137
188
16
219
116
240
137
188
16
65
160
103
209
72
138
65
160
103
209
72
138
202
125
172
96
248
40
202
125
172
96
248
40
[0058] Similarly, a pair of halftone screen cells with an identical first three rows (second region) and a conjugate second three rows (first region), shown in Table 3, will generate an overlaying pattern as shown in FIG. 5 .
[0000]
TABLE 3
A pair of halftone screens, with an identical upper half and a conjugate lower half.
1
172
24
232
80
168
1
172
24
232
80
168
228
88
154
104
208
40
228
88
154
104
208
40
32
200
56
36
8
252
32
200
56
36
8
252
219
116
240
137
188
16
36
139
15
118
67
239
65
160
103
209
72
138
190
95
152
46
183
117
202
125
172
96
248
40
53
130
83
159
7
215
[0059] The method described in U.S. Pat. No. 6,731,409 extends the monochrome conjugate screen method described in U.S. Pat. No. 5,790,703 for generating monochrome watermarks for color halftoning to create color contrast by using combinations of conjugate screens and identical screens (a different halftone screen is used for each color separation). For example, apply the conjugate halftone screen shown in Table 2 to one channel, say cyan, and apply the conjugate halftone screen shown in Table 3 to another channel, say magenta. The result provides the highest contrast between cyan and magenta. FIG. 6 illustrates the result of combining the output of FIG. 4 in cyan and the output of FIG. 5 in magenta, where it is assumed no yellow and black inputs are applied. Since most applications of color halftoning have 3 or 4 color channels, other variations of combining conjugate screens and identical screens are possible and two examples of the results are shown in FIG. 7 . FIG. 7 illustrates the result of combining in yellow and blue (left) and red and green (right). As noted earlier, this method sometimes produces images having less than desirable contrast and low signal-to-noise ratios for detection.
[0060] The method for generating an authenticable color image described herein extends the single conjugate halftone screen method to produce color digital watermarks. The method for generating an authenticable color image proposes a significantly improved system for color digital watermarks using a single halftone screen for all color separations. In one embodiment, the method uses successive filling with a stochastic screen designed with an embedded watermark, the different separations work together in producing the watermark. The resulting halftone screen process produces a significantly higher signal to noise ratio for the watermark. The method is applicable to single halftone screen techniques such as successive filling halftoning using stochastic screens and similar halftoning techniques. The method offers a significant improvement in watermark signal to noise ratio over the previously disclosed color watermarking method.
[0061] When the method is applied to a stochastic halftone screen, the authenticable color image (or watermark) is embedded in the single stochastic screen. The stochastic halftone screen includes a plurality of cells, each cell having at least one first region and at least one second region, wherein each cell is spatially offset from a neighboring cell by at least a first distance; wherein a first region of a first cell of the stochastic halftone screen is substantially identical to a first region of a second cell of the stochastic halftone screen, and a second region of the first cell of the first stochastic halftone screen is substantially conjugate to a second region of the second cell of the first stochastic halftone screen. The conjugate region provides the watermark in the resulting halftone image. When the watermark is to be detected from a scan or other electronically captured image of the printed color document, distortions in the printing and scanning process can make the alignment difficult. In such circumstances, the identical regions of the two cells can help determine the alignment between the scans of the regions corresponding to the two cells and thereby aid the process of “synchronization” of the image with a shifted version for the purpose of watermark detection. In this respect, the disclosed system and method are also advantaged because the same screen is utilized for the different separations and therefore more of the printed dot locations in the two cells will be common in the identical screen regions.
[0062] The same stochastic halftone screen is used for all color separations. Successive-filling is a technique proposed for color halftoning wherein a single halftone screen is used for multiple separations, the separations are allocated “successive levels” of the screen. Thus if the input CMYK (Cyan, Magenta, Yellow, Black) color image is spatially constant with values for the separations arranged in a specific order as i1, i2, i3, and i4 (for instance, typically in order darkest to lightest these would correspond to K, M, C, and Y, respectively) the first i1 levels of the halftone screen i.e. 1 through i1 are used for the first separation, the next i2 levels of the halftone screen, i.e. i1+1 through i1+i2 are used for the second separation, the next i3 levels of the halftone screen, i.e. i1+i2+1 through i1+i2+i3 are used for the third separation, and the next i4 levels, i.e. i1+i2+i3+1 through i1+i2+i3+i4 are used for the fourth separation. It is understood that in this process if the levels of the halftone screen are exhausted, they are re-used employing exactly the same order as for the initial screen.
[0063] The successive fill process may be mathematically performed using several equivalent methods. One method is the method described in U.S. Pat. No. 6,844,941. An alternate method may include the following steps: summing image values corresponding to the plurality of color separations in a pre-determined order; comparing the image value sums of at least two separations to the stochastic screen thresholds; and for each dot, selecting the dot's color and placement based on results of the comparisons. The following relationship may also be used:
if (i1>screen_threshold), printing a dot having the color of the first separation; if (((i1+i2)>screen_threshold)) and (i1<screen_threshold))), printing a dot having the color of the second separation; and if ((i1+i2−M)>screen_threshold), printing a dot having the color of the second separation;
[0067] where i1, i2 are the image values of the image data for the first color separation and the second color separation, respectively, screen_threshold is the value of a threshold in the stochastic halftone screen, and M is the maximum threshold value.
[0068] This relationship may be further extended to three and four color separations. For the third separation, the relation is given by:
if (((i1+i2+i3)>screen_threshold)) and ((i1+i2)<screen_threshold)), printing a dot having the color of the third separation; and if (((i1+i2+i3−M)>screen_threshold)) and ((i1+i2−M)<screen_threshold)), printing a dot having the color of the third separation;
if ((i1+i2+i3−2*M)>screen_threshold), printing a dot having the color of the third separation;
[0071] Similarly, the process for the fourth separation is
if (((i1+i2+i3+i4)>screen_threshold) and ((i1+i2+i3)<screen_threshold)), printing a dot having the color of the third separation; and if (((i1+i2+i3+i4−M)>screen_threshold) and ((i1+i2+i3−M)<screen_threshold)), printing a dot having the color of the third separation; if (((i1+i2+i3+i4−M)>screen_threshold) and ((i1+i2+i3−M)<screen_threshold)), printing a dot having the color of the third separation; if ((i1+i2+i3−M)>screen_threshold), printing a dot having the color of the third separation.
[0076] Since successive filling uses a single halftone screen for all the color separations, the watermarks in the different separations act in concert (unlike the color contrast halftone watermarks where the independent separations act independently). As a result the watermark pattern has a higher signal to noise ratio and the shift for obtaining the watermark pattern is also estimated more easily from the scan of a print bearing the embedded watermark.
[0077] For illustrating the method for generating an authenticable color image, consider the pair of screens shown in Table 2 and consider the result of halftoning a region with input CMYK values K=C=M=Y=32, using successive filling with the order black, magenta, cyan, yellow (increasing lightness order as is common for successive filling). The result of halftoning this color region with these two halftone screens is shown in FIG. 8 where the left hand side corresponds to the result of halftoning with the screen on the left in Table 2 and the right side corresponds to the result of halftoning with the screen on the right in Table 2. The result of overlaying these two halftone images (in the process of halftone detection) is shown in FIG. 9 , where the image on the left hand side indicates the overlay in color and the image onto the right shows the result of detecting the presence of a halftone dot (of any colorant) on each pixel—for instance through the process of taking the minimum of RGB values in each pixel. From FIG. 9 , it can be seen that the process of successive filling and detection of dots on each pixel makes the color halftoning watermark analogous to the black and white watermark thereby significantly improving its detectability.
[0078] While the bitmaps presented here illustrate the improvements with the method for generating an authenticable color image in halftone bitmaps, it is important to consider the full process of watermarking and detection wherein the halftone bitmaps are printed and scanned prior to detection of embedded information. Experiments were conducted to evaluate the performance of the new scheme and to compare it with color contrast watermarking.
[0079] In order to evaluate the proposed method for generating an authenticable color image and to compare its performance with the color-contrast watermarking method, an experiment was performed. A monochrome halftone stochastic screen with an embedded conjugate watermark in the shape of an X was designed. Two watermarked halftone bitmaps were created using this screen: the first bitmap used the existing color-contrast watermarking scheme disclosed in U.S. Pat. No. 6,731,409, hereby incorporated by reference in its entirety, and the second used the method for generating an authenticable color image with successive filling as described above.
[0080] Aspects of the disclosed system may be found in a color xerographic printing system. For example, the halftone bitmaps were printed on a Phaser 850 printer from Xerox Corporation at 300 dpi resolution. One print was printed with a color contrast watermark (U.S. Pat. No. 6,731,409) and a second print was printed with the successive fill color watermark generated by the method for generating an authenticable color image. The two printed images were scanned using a UMAX Powerlook desktop scanner 300 dpi resolution and a watermark detection algorithm, carried out on a workstation with hardware, software and circuitry (memory, processor, etc.) suitable for performing digital image processing operations (e.g., halftoning), was executed on the scans. The result of the watermark detection algorithm on the color contrast watermarked image showed that the watermark was extremely faint and visible only in certain regions. The result of the watermark detection algorithm on the successive fill color watermark showed the watermark “X” pattern was clearly visible over most smooth regions of the image. From the results, it is clear that the proposed successive filling color watermark offers a very significant improvement in detectability in comparison to existing methods.
[0081] The signal to noise ratio (SNR) of each watermark was also estimated using the watermark detection algorithm. The average SNR for the color contrast watermarking scheme is 0.88 and the average SNR for the successive filling watermarking scheme is 3.34. The much higher SNR for the successive filling watermarking is consistent with the visual results and indicates the significant improvement in performance offered by the method for generating an authenticable color image. The experimental results indicate that the method for generating an authenticable color image provides a very significant improvement in color halftone watermarks bringing this technology much closer to practical applications, most of which involve color.
[0082] While the description thus far has been directed to watermarking of color halftone images generated using stochastic halftone screens, the method of the proposed invention may also be applied for color data embedding using error diffusion. In one embodiment, this can be realized by adapting the monochrome halftone data embedding method disclosed in U.S. Pat. No. 6,636,616 to color using a successive filling technique such as the one described in U.S. Pat. No. 6,721,063. Both U.S. Pat. No. 6,636,616 and U.S. Pat. No. 6,721,063 are hereby incorporated by reference in their entirety.
[0083] This process is best illustrated by means of an example. It is to be noted that the example is for illustrative purposes and in actual practice several different realizations are possible. Suppose the pattern illustrated in FIG. 10 is to be embedded in a color halftone image consisting of CMYK planes. Embedding is accomplished by halftoning the multiple separations using a joint error diffusion method and introducing a bias in the error diffusion image halftoning process—through the addition of a watermark pattern dependent bias. An exemplary bias pattern is illustrated in FIG. 11 , where it is twice the size of the watermark pattern to be introduced. The pattern is zero except in regions corresponding to the watermark pattern where it is takes complementary values in the left and right halves 1110 and 1112 , respectively. This bias is added to the threshold for error diffusion. The values t and u may be chosen for instance as t=−u=64. The addition of this bias pattern to the threshold in the halftoning process favors the placement of printed halftone dots on pixels labeled as u's (because the threshold is lowered in these regions) and discourages the placement of dots in the pixels where the bias is t (because the threshold is raised in these regions). Since the bias pattern in FIG. 11 has the t's and the u's transposed on the right half in relation to their locations in the left half, the printed halftone dots in the output would have a propensity to lie in complementary locations. If the halftone image (or a suitable scan of the printed halftoned image) is shifted horizontally to the right by a displacement corresponding to half the size of the rectangle indicated in FIG. 11 and overlaid on itself, the dots in the regions corresponding to the “+” shaped watermark pattern would tend to lie on different locations while the dots in the regions outside the “+” shaped watermark pattern would tend to be randomly located in the shifted version. Thus the “+” shaped watermark pattern would appear as a darker region. The contrast of the watermark may be further improved by biasing the blank pixels shown in FIG. 2 to make dots in those regions have a higher propensity to lie in identical locations. The description thus far does not indicate how the color planes are accommodated; accordingly one algorithmic embodiment of the manner in which this may be accomplished is now presented:
[0084] Consider a CMYK (Cyan, Magenta, Yellow, Black) color image where the values for the separations are indicated in a specific order at pixel location (x,y) as i1(x,y), i2(x,y), i3(x,y), and i4(x,y), which are assumed to be distributed between 0 and 1 for our description in this part. Then the process may be described as follows:
[0085] Compute the sum of all colorants s(x,y)=i1(x,y)+i2(x,y)+i3(x,y)+i4(x,y)
[0086] Apply a multilevel error diffusion to the sum to quantize each pixel location to 0 (no dots), 1 (one colorant dot), 2 (two colorant dots), 3 (three colorant dots) and 4 (four colorants dots). This process can be achieved for instance by computing for each pixel a modified value i(x,y)=s(x,y)+e(x,y) where e(x,y) is the error diffused to the location (x,y) from previously processed locations in accordance with well-known error diffusion methods. Quantize i(x,y) to the four levels to obtain an output value o(x,y) as follows:
[0000]
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[0087] where w(x,y) is the bias at pixel location (x,y) determined in accordance with the watermark pattern as indicated above. Diffuse the quantization error i(x,y)−o(x,y) to the neighbors not processed yet in accordance with established error diffusion procedures.
[0088] Apply independent error diffusion with constraints to the individual separations to determine the colorants to be included as each of the locations identified in step 2. For example for the first separation, compute i1′(x,y)=i1(x,y)+e1(x,y) where e1(x,y) is the error diffused to the location (x,y) from previously processed locations of the first separation in accordance with well-known error diffusion methods. Similarly calculate i2′(x,y), i3′(x,y), i4′(x,y). For quantization of the values however use the constraints on the number of pixels to be printed that were previously established, i.e., if o(x,y) is non-zero, pick the largest o(x,y) values from i1′(x,y), i2′(x,y), i3′(x,y), i4′(x,y) and set the corresponding values for the corresponding outputs o1′(x,y), o2′(x,y), o3′(x,y), o4′(x,y) as 1 leaving other values as 0. For each of the separations compute and diffuse the quantization error to the neighbors not processed yet in accordance with established error diffusion procedures.
[0089] It will be appreciated that various of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. | A method for generating an authenticable color image, the color image including a plurality of color separations, wherein an authentication image inserted in the multicolor image is not readily visually perceptible, includes halftoning image data corresponding to a first color separation using a single halftone screen, wherein the halftone screen includes means for generating an authentication image in a color image; and halftoning image data corresponding to a second color separation using the halftone screen and dot placement information for the image data corresponding to the first color separation to form a multicolor image; wherein halftoning of image data corresponding to the second color separation includes placing dots for the second color separation in thresholds of the halftone screen relative to those thresholds occupied by the first color separation in the halftone screen in accordance with a predetermined relationship. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to the method according to the preamble of claim 1 for doping and/or colouring glass, and especially to a method for doping glass, in which a two- or three-dimensional layer is formed of nanomaterial on the surface of the glass and allowed to diffuse and/or dissolve into the glass to change the transmission, absorption, reflection and/or scattering of electromagnetic radiation of the glass. In this context, colouring refers to doping glass in such a manner that the transmission or reflection spectrum of glass changes in the visible light region (approximately 400 to 700 nm) and/or ultraviolet region (200 to 400 nm) and/or near infrared region (700 to 2000 nm) and/or infrared region (2 mm to 50 mm). According to the invention, glass can be coloured in such a manner that a nano-sized material (size below 100 nm in two or three dimensions) is directed to the surface of glass, the temperature of which is at least 500° C., and the material consists of at least a glass-colouring compound, such as a transition metal oxide, and an element or compound that lowers the melting temperature of the oxide, such as an alkali metal oxide. The material dissolves and/or diffuses on the surface of glass and dopes it in such a manner that it turns into the colour characteristic of the colouring compound.
[0002] So as to be able to colour glass efficiently, i.e. in a sufficiently short time, at a temperature of 500 to 800° C., the material used in the colouring must be in nanosize. There are two reasons for this. Firstly, the diffusion rate of particles in a medium depends essentially on the size of the particles, and typically, the diffusion rate of particles of 10 nm is three times faster than particles of 1 micrometer. Secondly, the surface area and surface energy required for colouring reactions is bigger when the material is in nanosize.
[0003] For the sake of clarity, it should be noted that the size of less than 100 nm in three dimensions refers to particles with a diameter of less than 100 nm, and the size of less than 100 nm in two dimensions refers to thin films with a thickness of less than 100 nm. In the following, the text refers mainly to nano-sized particles, but the invention can also be applied using thin films.
[0004] The method of the invention can be used to colour flat glass, packing glass, utility or household glass, and special glass, such as optical fibre blanks.
DESCRIPTION OF THE PRIOR ART
[0005] Colouring glass refers on a wide scale to altering the interaction between glass and electromagnetic radiation directed to it in such a manner that the transmission of the radiation through the glass, reflection from the surface of the glass, absorption into the glass, or scatter from the components in the glass changes. The most important wavelength regions are the ultraviolet region (e.g. preventing ultraviolet radiation of sun through glass), the visible light region (altering the colour of glass visible to the human eye), the near infrared region (altering the transmission of sun infrared radiation, or glass material used in active optical fibres), and the actual infrared region (altering the transmission of heat radiation).
[0006] Glass can be coloured in many different ways. Most typically, glass is coloured by adding into molten glass or its raw materials compounds of colour-producing metals, such as iron, copper, chromium, cobalt, nickel, manganese, vanadium, silver, gold, rare earth metals, or the like. Such a component will cause absorption or scattering of a certain wavelength region in the glass, thus producing a characteristic colour in the glass. However, adding a colouring substance in molten glass or raw materials makes changing the colour an extremely expensive and time-consuming procedure. Therefore, the manufacture of especially small batches of coloured glass is expensive.
[0007] Nickel oxide is used in colouring glass grey. When glass is made with a float process, the molten glass web runs on a tin bath. To prevent the tin bath from oxidizing, there is a reducing gas atmosphere on the tin bath. However, this causes nickel to reduce on the surface of glass, whereby metal nickel is formed on the surface of glass and creates a gauze or veil on the surface, which weakens the quality of the glass. To eliminate this problem, nickel-free grey glass compositions have been developed, such as the one disclosed in U.S. Pat. No. 4,339,541. The method is thus still based on colouring molten glass entirely.
[0008] U.S. Pat. No. 4,748,054 discloses a method for colouring glass with pigment layers. In this method, glass is sandblasted and different enamel layers are pressed on it to be then attached to the surface by burning. However, the chemical or mechanical wear resistance of such a glass is poor.
[0009] U.S. Pat. No. 3,973,069 discloses an improved method of colouring glass with diffusion. The improvement is provided with electric potential. The patent describes as a known method a method for colouring glass with colour metal ion diffusion in such a manner that glass is brought into contact with a medium that contains colouring ions, and the ions then diffuse from the medium to the glass. The glass colouring mechanism is then specifically based on the diffusion of ions and not on the diffusion of a nano-sized material with the glass. Similarly, the diffusing substance is not an oxide, but a metal ion. The patent only refers to colouring glass with silver. However, this colouring mechanism is not a pure diffusion, but an ion exchange reaction (silver/sodium ion).
[0010] U.S. Pat. No. 5,837,025 discloses a method for colouring glass with nano-sized glass particles. According to the method, glass-like, coloured glass particles are made and directed to the surface of the glass being coloured and sintered into transparent glass at a temperature of less than 900° C. The method differs from the present invention in that in the present invention, the particles diffuse inside glass and do not form a separate coating on the surface of the glass.
[0011] Finnish Patent FI98832, a method and device for spraying material, discloses a method that can be used in doping glass. In this method, the material being sprayed is directed in liquid form into a flame and transformed into droplets with the aid of a gas essentially close to the flame. This produces extremely small particles that are a nanometre in size quickly, inexpensively and in one step. The patent does not, however, describe the size of the produced liquid droplet. Neither does the patent describe the interaction between the produced particles and glass material.
[0012] Finnish patent FI114548 describes a method for colouring glass with colloidal particles. The patented method uses a flame spraying method to transport colloidal particles to the material being coloured. In the method, it is also possible to add other components to the flame, such as a glass-forming liquid or gaseous material, which assist the formation of correct-sized colloidal particles in the material. The patent does not state any other functions for the glass-forming liquid or gaseous material.
[0013] When using the method described in FI98832 for colouring glass, it has been found that a gauzy curtain may appear on the surface of the glass especially when colouring the glass in low temperatures of less than 700° C. The gauze is assumed to be due to crystalline areas remaining on the surface of the glass, whose proportion on the surface increases with the temperature difference between the melting point of the colouring component and glass surface. In cobalt oxide, whose melting point is 1795° C., the crystalline portion is larger than in iron oxide, whose melting point is 1369° C. or 1594° C. depending on the crystal form. In copper oxide, whose melting point is 1235° C. or 1326° C. depending on the crystal form, the crystalline portion is even smaller than in iron oxide.
[0014] When colouring glass with the method of FI98832 or some other method, in which the colouring is based on the diffusion and dissolution into glass of nanoparticles (particle diameter less than 100 nm), the colouring should, for economic reasons, be done when the temperature of the glass is 500 to 650° C. The colouring can then be done in a float line between the tin bath and cooling oven (temperature 550 to 630° C.) or in a glass tempering line (temperature approximately 620° C.). Colouring must then not produce crystal-line and/or gauzy areas on the surface of the glass.
SUMMARY OF THE INVENTION
[0015] It is thus an object of the present invention to provide a method for doping and/or colouring glass in such a manner that the above-mentioned prior-art drawbacks are eliminated. The object of the invention is achieved by a method according to the characterising part of claim 1 , which is characterised in that the layer of nanomaterial contains at least one component that provides the above-mentioned change, and at least one component that lowers the melting point of the component providing the above-mentioned change.
[0016] With the method of the present invention, glass can be coloured when the temperature of the surface of the glass is higher than 500° C.
[0017] The present invention is based on the idea that a nano-scale material is directed to the surface of the glass, the material consisting of at least two components: a metal compound providing a characteristic colour for the glass and a component lowering the melting point of the metal compound.
[0018] The lowering of the melting point of the compound can also take place in such a manner that the nanomaterial has components that trans-form the metal compound providing a characteristic colour into an amorphous form in the nanoparticle.
[0019] The lowering of the melting point of a compound can also take place in such a manner that the metal compound providing a characteristic colour and the component lowering the melting point of the compound are in different nanoparticles or films that are brought into contact with each other to produce essentially the same outcome as when these components are in the same nanoparticle or film.
BRIEF DESCRIPTION OF THE FIGURES
[0020] The invention will now be described in greater detail by means of preferred embodiments and with reference to the attached drawings, in which
[0021] FIG. 1 is a flow chart showing an implementation method of the invention, and
[0022] FIG. 2 shows equipment used in implementing the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention relates to a method for colouring glass in a wavelength region that extends from ultraviolet radiation to infrared radiation. The temperature of the glass being coloured is above 500° C. The invention is based on directing to the surface of the glass a material less than 100 nanometres in size and consisting of a metal compound that provides a characteristic colour for the glass and a component that lowers the melting point of the metal compound.
[0024] Combinations of the colouring metal compound and the component lowering its melting point include CoO—V 2 O 5 , CoO—CaO, CoO—B 2 O 3 , Cu 2 O—PbO, Cu 2 O—SiO 2 , CoO—SiO 2 , CoO—TiO 2 , MnO—SiO 2 , MnO—Al 2 O 3 —SiO 2 , MnO—Al 2 O 3 —Y 2 O 3 —SiO 2 , Fe 2 O 3 —P 2 O 5 , and Mno—P 2 O 5 . It is apparent to a person skilled in the art that there are numerous compounds of this type and that the melting point of the compounds is lower than that of the colouring compound possibly only in some mixture ratios. The best result is obtained when the components form a eutectic mixture ratio, but the formation of such a eutectic mixture ratio is not necessary.
[0025] The nano-sized material essential for the present invention can be produced in many ways, such as with a flame method, laser ablation, sol-gel method, chemical vapour phase deposition (CVD), physical vapour phase deposition (PVD), atom layer deposition (ALD) method, molecular beam epitaxy (MBE) method, or the like. The following presents the use of a hot aerosol layering method to produce the material of the invention.
[0026] According to the flowchart of FIG. 1 , the method of the invention forms a flame in step 11 . In this context, the term ‘flame’ refers to any method of producing a high, local temperature. These include a fuel/oxygen flame, a plasma flame, an electric arc, or a high temperature provided with laser heating.
[0027] In step 12 , a liquid raw material, for instance, is directed to the flame or close to it. The liquid raw material contains a metal compound that as a result of a chemical reaction or vaporisation/condensation in the flame produces nano-sized particles that contain a glass-colouring metal compound, typically metal oxide. The raw material fed into the flame in step 12 also contains a starting material that as a result of the chemical reaction and/or vaporisation/condensation in the flame produces nano-sized particles that contain a component that lowers the melting point of the compound of the glass-colouring metal compound. The nanoparticles created in step 12 can be particles that contain both the glass-colouring metal compound and the component that lowers the melting point of the metal compound. The nanoparticles created in step 12 can be crystalline or amorphous, as long as the melting temperature of the produced material is lower than that of the glass-colouring metal compound.
[0028] In the next step 13 of the method, at least one liquid component is transformed into droplets in such a manner that the formed droplets contain the colouring component, or a reaction in which the colouring component has partaken, the second component created as a result, or a compound of these two. Said droplets can preferably be made to contain said colouring component, if the colouring component is already dissolved in the liquid being made into droplets when it is fed into the flame.
[0029] It is essential for an efficient formation of nanoparticles created in the flame that the sprayed liquid material is brought into the flame in very small droplets. If the liquid material is brought into the flame in larger droplets, the process produces not only nanoparticles, but also larger particles that will not dissolve into the glass being coloured, and thus weaken the quality of the glass. The optically measured diameter of the droplets being created must therefore preferably be less than 10 micrometers, more preferably less than 6 micrometers, and most preferably less than 3 micrometers. The droplets can be produced by using generally known atomisation methods, such as gas-distributed atomisation, pressure atomisation, or ultrasound-based atomisation.
[0030] In the next step 14 of the method, the droplets and the components contained therein are evaporated and condensated, whereby the condensated components form ultra-small particles either through chemical reactions, mainly oxidisation reaction, or through nucleation/condensation. Evaporation and condensation can preferably be done with the heat of the flame or with an exothermally reacting solvent.
[0031] The composition, content, and size distribution of the created particles can be controlled by adjusting the operating parameters of the method, such as the temperature of the flame, flow rates of the gases, composition of the components fed to the flame, interrelations and absolute quantities of the components. Controlling the size distribution of the created particles is important, because the size of the particles plays a significant role in successful colouring of glass. It is especially essential that all particles be created through evaporation-nucleation, whereby no large residual particles are created in the process. The creation of residual particles can be avoided, if the droplet size of the liquid being sprayed is sufficiently small.
[0032] The particles created in the last step 15 of the method are brought into contact with the material to be coloured. The particles collect on the surface of the glass to be coloured mainly due to diffusion and thermophoresis. Owing to the large specific area of the particles, they diffuse and dissolve into the glass and provide to the glass a colour that is characteristic of the metal or metals in the particles. Due to the components that lower the melting point of the metal compounds in the particles, no crystalline or gauzy areas are formed in the glass, which would weaken the quality of the glass.
[0033] FIG. 2 shows equipment for colouring glass with the method of the invention. The shown equipment is a flame spraying apparatus based on a flame provided by burning gas, but it is clear to a person skilled in the art that instead of a gas flame, the heat source (thermal reactor) can also be a plasma flame, for instance.
[0034] The equipment 20 comprises a nozzle 21 that forms a flame 29 for spraying the colouring component 27 . The nozzle is preferably made up of nested pipes 22 a, 22 b, 22 c, 22 d, through which the components used in the spraying can be conveniently brought to the flame 29 .
[0035] To produce the flame 29 , a combustion gas, such as hydrogen, is brought to the nozzle 21 from container 23 b through pipe 22 b serving as a feed channel. Correspondingly, the oxygen required for producing the flame is brought from container 23 c to feed pipe 22 c. Feed pipe 22 c can be connected to feed pipe 22 b, if a premixed flame is to be used. The combustion gas and oxygen flowing through the nozzle S form the flame 29 . To control reactions in the flame or in its vicinity, it is also possible to feed a protective gas to the process from container 23 a through feed channel 22 a.
[0036] For the sake of simplicity, FIG. 2 only shows a situation, in which the component essential for colouring and the component essential for the formation of the eutectic mixture or partially eutectic mixture are already mixed or dissolved into the liquid to be atomised in container 23 d. Possible modifications to the device, such as arranging more liquid feeds, vapour feeds, or gas feeds by increasing the number of nested or adjacent pipes, or by connecting more containers to the same inlet, or by bubbling the component with combustion gases or a protective gas, are apparent to a person skilled in the art.
[0037] In the device of FIG. 2 , the liquid to be sprayed is fed from chamber 23 d to supply channel 22 d. Along the supply channel, the liquid is directed to the nozzle S that sprays it and is shaped in a manner known per se to achieve the desired flow properties. The liquid flowing through the nozzle S is made into droplets 28 preferably with a gas flowing from supply channel 22 b . To achieve an as efficient droplet-to-nanoparticle transformation as possible, the diameter of the droplets must be at most 10 micrometers. Under the thermal energy released from the flame 29 , the droplets 28 form particles 27 that are preferably directed to the glass being doped. Owing to the large specific area of the particles, they diffuse and dissolve into the glass and produce into the glass the colour characteristic of the metal or metals in the particles. Due to the components that lower the melting point of the metal compounds in the particles, no crystalline or gauzy areas are formed in the glass, which would weaken the quality of the glass.
[0038] The equipment 20 also comprises a control system 26 for controlling the operating parameters of the equipment in such a manner that as the droplets 29 and their contents evaporate and react/nucleate, the properties, such as content and particle size distribution, of the created particles 27 can be controlled.
EXAMPLES p In the following, the invention will be described in more detail with examples.
Example 1
Colouring Glass Blue with Cobalt
[0039] It is known that cobalt oxide and silicon oxide form a eutectic mixture whose melting point is approximately 1377° C., i.e. approximately 400° C. lower than that of cobalt oxide. Such a mixture contains approximately 75% cobalt oxide and 25% silicon oxide.
[0040] The raw material of cobalt oxide was prepared by dissolving 25 g cobalt nitrate hexahydrate, Co(NO 3 ) 2 •6H 2 O, into 100 ml methanol. This solution was fed to middle channel 22 d of the flame spraying equipment shown in FIG. 2 at 10 ml/min. The flame spraying equipment was positioned in such a manner that forming droplets and particles took place in an oven having a temperature of 600° C. Droplets were formed from the liquid by feeding hydrogen gas into channel 22 b at a volume flow of 20 l/min, whereby the speed of the hydrogen gas at the nozzle S was approximately 150 m/s. The fast hydrogen gas flow formed droplets of less than 10 micrometers of the liquid flow. Nitrogen gas was fed from channel 22 c at a flow rate of 15 l/min. Some of the nitrogen gas, approximately 5% of the volume flow, was first directed from feed bottle 23 c through a bubbler. The bubbler contained silicon tetrachloride, SiCl 4 , that evaporated with the nitrogen gas flow. After this, the nitrogen flow containing evaporated silicon tetrachloride was combined with the rest of the nitrogen flow and directed to channel 22 c. The temperature of silicon tetrachloride was adjusted so that silicon tetrachloride produced, in comparison with the cobalt nitrate flow, such a mass flow that the ratio of cobalt oxide and silicon oxide created in the process was 3:1. Oxygen gas was fed to channel 22 a at a volume flow of 10 l/min. The raw materials reacted in the flame and formed CoO—SiO 2 nanoparticles having an average diameter of approximately 30 nm. The particles partially agglomerated into particle chains. The particles were directed to flat glass that moved at a speed of 0.2 m/min in the 600-degree oven. The distance of the flame spraying equipment nozzle S from the surface of the glass was 155 mm. After the coating, the tensions in the glass were removed by keeping the glass for 15 minutes at a temperature of 500° C., after which the glass was cooled to room temperature during three hours. After the cooling, it could be seen that the glass had turned blue, and there was no gauze or crystalline materials in it.
Example 2
Colouring Glass Grey with Nickel
[0041] It is known that nickel oxide, NiO, and vanadium pentoxide, V 2 O 5 , form a mixture whose melting point at every mixture ratio is lower than the melting point of nickel oxide. In the exemplary test, nanoparticles were prepared containing approximately 60% nickel oxide and 40% vanadium pentoxide. The melting point of such a material is approximately 900° C., i.e. approximately 1000° C. lower than that of nickel oxide.
[0042] The raw material of nickel oxide was prepared by dissolving 25 g hexahydrate of nickel nitrate, Ni(NO 3 ) 2 •6H 2 O, into 100 ml ethanol. The raw material of vanadium pentoxide was prepared by dissolving 2.9 g vanadium chloride, VCl 2 , into 100 ml ethanol. The solutions were then mixed together. This solution was fed to middle channel 22 d of the flame spraying equipment shown in FIG. 2 at 10 ml/min. The flame spraying equipment was positioned in such a manner that forming droplets and particles took place in an oven having a temperature of 600° C. Droplets were formed from the liquid by feeding hydrogen gas to channel 22 b at a volume flow of 20 l/min, whereby the speed of the hydrogen gas at the nozzle S was approximately 150 m/s. The fast hydrogen gas flow formed droplets of less than 10 micrometers of the liquid flow. Oxygen gas was fed to channel 22 a at a volume flow of 10 l/min. The raw materials reacted in the flame and formed NiO—V2O5 nanoparticles having an average diameter of approximately 30 nm. The particles partially agglomerated into particle chains. The particles were directed to flat glass that moved at a speed of 0.2 m/min in the 600-degree oven. The distance of the flame spraying equipment nozzle S from the surface of the glass was 155 mm. After the coating, the tensions in the glass were removed by keeping the glass for 15 minutes at a temperature of 500° C., after which the glass was cooled to room temperature during three hours. After the cooling, it could be seen that the glass had turned grey, and there was no gauze or crystalline materials in it.
[0043] It is apparent to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many ways. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims. | The invention relates to a method for doping and/or colouring glass. In the method a two- or three-dimensional layer is formed on the surface of the glass, and the layer is further allowed to diffuse and/or dissolve into the glass to change the transmission, absorption, reflection and/or scattering of the electromagnetic radiation of the glass. The layer of nanomaterial includes at least one component that causes the above-mentioned change and at least one component that lowers the melting point of the above-mentioned component causing the change. | 2 |
FIELD OF INVENTION
[0001] The present invention relates to a CHO (Chinese hamster ovary) cell line transfected with 30 K gene. More particularly, the present invention is directed to a CHO cell line transfected with 30 K genes obtained from the silkworm Bombyx Mori , which has anti-apoptotic property.
DESCRIPTION OF THE RELATED ART
[0002] The CHO cell line of the present invention means a cell line obtained from Chinese hamster ovary, has been verified safety and stability, and thus can be easily approved by supervisory institutions such as the FDA in USA.
[0003] In the field of biology and medical science, a desired target protein can be obtained mainly by culturing transfected cell lines. The methods using CHO (Chinese Hamster Ovary) cell line, BHK (Baby Hamster Kidney) cell line, and NSO cell line (Murine myeloma cell line) are examples used for the production of target proteins in the industry (Ogata, et al., Applied Microbiology and Biotechnology, 1993, 38(4), 520-525; Kratje, et al., Biotechnology Progress, 1994, 10(4), 410-20; Peakman, et al., Human Antibodies Hybridomas, 1994, 5(1-2), 65-74).
[0004] Among the above cell lines, the CHO cell line is the most effectively used host cell line in the industry for the mass-production of target proteins using animal cells. There are five main reasons that the CHO cell line is industrially preferred:
(i) The posttranslational modification process of protein, that is, glycosylation or phosphorylation process, is similar to that of the human cells; (ii) Suspension culturing as well as adhesion culturing of the cell is possible; (iii) Relatively high concentrations of cells can be achieved compared with other cell lines cultured in a serum-free culture medium; (iv) The productivity of the target protein, which is significantly lower than that of other microorganisms, can be increased by the dihydrofolate reductase/methotrexate (DHFR/MTX) amplifying system; and (v) Since safety and stability of the CHO cell line has been verified, the cell line can be easily approved by supervisory institutions such as the FDA.
[0010] Recombinant CHO cell lines can be prepared by transfecting a target gene into the CHO cell line. To mass-produce target proteins industrially using a recombinant CHO cell line, the recombinant CHO cells should be cultured as suspended forms in culture medium.
[0011] By the way, the serum employed in the culture medium, may contain various unidentified proteins which should not be allowed for the preparation of pharmaceutical formalation. Therefore, in order to employ the serum as a component of the cell culture medium, the serum should be treated through expensive refining process.
[0012] In addition, recently, health supervisory institutions such as the FDA require the exclusion of serum throughout the entire process due to an outbreak of mad cow disease. When the CHO cell line is cultured as a suspended form in a serum-free culture media; however, the amount of produced target protein tends to decrease due to the apoptosis (Itoh, et al., Biotechnology and Bioengineering, 1995, 48, 118-122; Suzuki, et al., Cytotechnology, 1997, 23, 55-59; Simpson, et al., Biotechnology and Bioengineering, 1997, 54, 1-16).
[0013] Furthermore, the decrease in survival rate caused by programmed cell death not only lowers the productivity of target proteins but also affects the stability of target proteins as various proteases, present inside the cells, get secreted by cell lysis. Thus, the DNA and cell debris of the lysed cells complicate the subsequent purifying process.
[0014] In addition, when sodium butyrate (NaBu) is added in order to increase the amount of target proteins, apoptosis tends to be increased.
[0015] The mechanism of programmed cell death is as follows. When the initiator caspase, a kind of protease, is activated by various stimuli, the membrane potential of mitochondria is disintegrated. Thereafter, cytochrome C, which is involved in the electron transfer system of mitochondria, is released from the cytoplasm. Cytochrome C released into the cytoplasm activates the effector caspase such as caspase 3, and thus, phophatidylserine, one of the main components of the phospholipid in the cell membrane, flips towards the cytoplasm. Accordingly, the DNA is digested by the activated endonuclease, and thus, the cell eventually undergoes apoptosis.
[0016] Meanwhile, an apoptosis-inhibiting component of silkworm hemolymph, was isolated and characterized in the present inventor's previous research USA patent application Ser. No. 10/926,406 and Korean Patent Application No. 10-20020059686 of the present inventors disclose the facts that the expression of 30 K inhibited apoptosis comparably to that of whole silkworm hemolymph and that both intracellular expression and external supplementation inhibited apoptosis.
SUMMARY OF THE INVENTION
[0017] The primary purpose of the present invention is to provide a Chinese hamster ovary cell line (KCLRF-BP-00103) transfected lath 30 K gene of SEQ. ID. No. 1, which has anti-apoptotic property.
[0018] The present inventors prepared CHO cell lines transfected with 30 K genes, which is obtained from silkworm, coding for the anti-apoptotic 30 K proteins, and showed that the apoptosis can be decreased and consequently the target protein can be mass produced by employing the anti-apoptotic CHO cell line of the present invention.
[0019] Another object of the present invention is to provide the Chinese hamster ovary cell according to claim 1 , which further containing a gene encoding hematopoietic growth factor.
[0020] It is a still another object of the present invention to provide the Chinese hamster ovary cell lute according to claim 2 , wherein said hematopoietic growth factor is erythropoietin (EPO) protein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above objects and other advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings, in which:
[0022] FIG. 1 is the photograph of RT-PCR analysis of 30 K mRNA in the stable CHO cell lines transfected with 30 K expression construct.
[0023] FIG. 2 is a set of graphs comparing cell concentration of the CHO cell line overexpressing 30Kc6 protein with those of a control group of CHO cells cultured in serum-free medium.
[0024] FIG. 3 a is a set of graphs comparing EPO production per medium volume in serum-free medium.
[0025] FIG. 3 b is a set of graphs comparing EPO production per cells in serum-free medium.
[0026] FIG. 4 is a photograph of two-dimensional electrophoresis of EPO samples.
[0027] FIG. 5 is a photograph of lectin binding assay of EPO samples.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The object of the present invention can be achieved by providing a Chinese hamster ovary cell line (KCLRF-BP-00103) transfected with 30 K gene of SEQ. ID. No.1, which has anti-apoptotic proterty.
[0029] It has been shown that silkworm hemolymph inhibits apoptosis in insect, mammalian, and human cell systems. These results indicate that silkworm hemolymph contains a component that inhibits apoptosis. More recently, this anti-apoptotic fraction was isolated from silkworm hemolymph and characterized by the present inventors.
[0030] The fraction of silkworm hemolymph with the highest activity was found to contain 30 K proteins, which are a specific type of plasma protein called “storage proteins”. These proteins constitute a group of structurally related proteins of approximate molecular weight 30,000 Da. The 30 K protein group consists of five proteins, (30Kc6 (GenBank Accession No.:X07552), 30Kc12 (GenBank Accession No.:07553), 30Kc19 (GenBank Accession No.:X07554), 30Kc21 (GenBank Accession No.:X07555), 30Kc23 (GenBank Accession No.:X07556), which have common characteristics in amino acid composition and immunological activity, as well as molecular weight. We found that the intracellular expression of 30 K as a representative 30 K protein in mammalian cells inhibits apoptosis in this invention.
[0031] Recombinant CHO cell lines producing target proteins are produced by transfecting a target gene into the CHO cell line of the present invention. To mass-produce target proteins industrially using a recombinant CHO cell line, the recombinant CHO cells should be cultured as suspended forms in a serum-free culture media.
[0032] When the CHO cell line is cultured as suspended form in a serum-free culture media, the amount of produced target protein tends to decrease due to the apoptosis.
[0033] The expression of 30 K resulted in lower intracellular activity for caspase 3. However, the results of in vitro assay of caspase 3 show that the 30 K protein does not inhibit caspase 3 activity. This indicates that the 30 K protein inhibits the apoptosis by working in a further upstream event than caspase 3 activation.
[0034] The inhibition of apoptosis is expected to increase in productivity of target proteins by extending longevity of the transfected CHO cell line and to maintain the molecular integrity of unstable target proteins in a medium by decreasing cell lysis.
[0035] The present inventors deposited the CHO cell line transfected with 30 K gene at the gene bank of Korea Cell Line Research Foundation (KCLRF-BP-00103). The 30 K gene used in this invention is the DNA of SEQ. ID. No.1.
[0036] Another object of the present invention can be achieved by providing the Chinese hamster ovary cell line transfected with 30 K gene, which further containing a gene encoding hematopoietic growth factor.
[0037] The hematopoietic growth factor of the present invention is stimulating factor of hematopoiesis. Hematopoiesis is stimulated by a hematopoietic growth factor. Hematopoiesis is the process of renewal and replacement of the cells and formed elements of blood. Blood cells are constantly formed through a process called hematopoiesis.
[0038] There are GCSF (Granulocyte colony-stimulating factor), MCSF (Macrophage colony-stimulating factor), EPO (Erythropoietin) and IL (Interleukin), etc. in hematopoietic growth factor.
[0039] Erythropoiesis is a subset of this larger scheme and includes only these events that lead from the appearance of the committed erythroid progenitor cell through the formation of mature red blood cells.
[0040] The production of red blood cells is stimulated by hormone called erythropoietin which is secreted by the kidneys. The secretion of erythropoietin by the kidneys is stimulated whenever the delivery of oxygen to the kidneys and other organs is lower than normal.
[0041] Under these conditions which can occur, for example, when a person lives at high attitude the increased production of red blood cells allows the blood to carry a higher concentration of oxygen to the tissues.
[0042] Plasma erythropoietin is a sialoprotein consisting of 165 amino acids. This glycoprotein contains over 40% carbohydrate, consisting of sialic acid and a number of sugars. The sialic acid residues are necessary for biological activity in vivo as in the asialo form it is cleared too rapidly by the liver.
[0043] Hereinafter, the present invention will be described in greater detail with reference to the following examples. The examples are given for illustration of the invention and not intended to be limiting the present invention.
EXAMPLE 1
[0000] Cell Line and Culture Condition
[0044] The recombinant Chinese Hamster ovary (CHO) cell lines producing human erythropoietin (EPO) and 30 K protein originating from silkworm hemolymph were grown in DMEM/F-12 (1:1) (JRH Bioscience) supplemented with 10% fetal bovine serum (FBS, Gibco), L-glutamine, 15 mM HEPES buffer, and penicillin/streptomycin (Gibco). Cells were Captained at 37° C. in a humidified air atmosphere with 5% CO 2 . To produce recombinant human EPO, the growth medium with 10% FBS was replaced with serum-fee medium, EXCELL 301 (JRH Bioscience).
EXAMPLE 2
[0000] Establishment of Stable Recombinant CHO Cell Line Producing 30Kc6
[0045] A cDNA clone containing 30Kc6 was kindly provided by S. Izumi (Department of Biology, Tokyo Metropolitan University). He indicated that it was constructed as follows (personal communication): A DNA fragment for one component of 30 K proteins (30Kc6 GenBank accession number, X07552) was amplified by RT-PCR from fifth larval fat body RNA with synthetic oligonucleotide primers specifically used for 30Kc6.
[0046] The resulting DNA fragments were digested by EcoRI and inserted into the EcoRI site of pBluescript KS+. We cloned the entire open reading frame of the 30Kc6 into the mammalian expression vector pcDNA3 (Invitrogen).
[0047] The pcDNA3/30Kc6 or pcDNA3, the vector alone as a control, was transfected to CHO cells by the LipofectAMINE Reagent (Gibco) according to the manufacturer's instructions. For the establishment of stable cell lines expressing 30 K protein, CHO cells were transfected with the indicated plasmids and moved 48 h later into a selection medium containing 500 μg/mL G418 (Gibco). Selection media were changed every 2-3 days so as to form the colony.
[0048] After 3 weeks, clonal selection by picking the colonies was performed for single cell clones. Transfection efficiency was analyzed using a pEGFP expression vector. The cell lines were cotransfected with pEGFP expression vector and test plasmids, and successfully transfected cells were detected by green fluorescent protein (GFP) florescence.
[0049] FIG. 2 represents the effect of 30 K protein expression on the cell growth in serum-free medium.
EXAMPLE 3
[0000] RT-PCR
[0050] The total cellular RNA was extracted by RNA isolation kit PURESCRIPT (Gentra systems) according to the manufacturer's instructions. RNA concentration was measured spectrophotometrically. Using a sequence specific primer (30Kc6 reverse primer: 5-TCG TTT TCA GCT TCA GCT TTA-3), cDNA was synthesized from 3 μg of total RNA.
[0051] PCR was performed for 36 cycles by the following program for each cycle: denaturation at 95° C. for 1 min. annealing at 60° C. for 30 s, and extension at 72° C. for 1 min using a 30Kc6 forward primer (5-ACA GTG TTG TGA CTG cTT TCA-3) and reverse primer (5-TCG TTT TCA GCT TCA GCT TTA-3). The PCR product was analyzed on 1% agarose gel by electrophoresis.
[0052] FIG. 1 is the photograph of RT-PCR analysis of 30 K mRNA in the stable CHO cell times transfected with 30 K expression construct. The expected size for the PCR product is 890 bp for the 30 K protein. Lane M, 1 kb molecular weight ladder; lane 1, transfected with pcDNA3; lane 2, transfected with pcDNA3/30Kc6.
EXAMPLE 4
[0000] Establishment of Stable Recombinant CHO Cell Line Producing both 30Kc6 and Human Erythropoietin (EPO) Protein
[0053] Human EPO cDNA was amplified by PCR with synthetic oligonucleotide primers and then inserted into Nhe I and Apa I sites of the mammalian expression vector pcDNA3.1/Zeo (+) (Invitrogen). The EPO gene in this plasmid is expressed under the control of human cytomegalovirus immediate-early promoter, and this plasmid confers resistance to Zeocin on the host cells. The pcDNA3.1/Zeo (+)/EPO was transfected to CHO-30Kc6 cell lines expressing silkworm hemolymph 30Kc6 protein by the LipofectAMINE 2000 reagent (Invitrogen) according to the manufacturer's instructions.
[0054] For the establishment of stable cell lines expressing both 30 K and EPO, CHO-30Kc6 cells were transfected with the indicated plasmids and moved 48 h later into the selection medium containing 500 μg/ml Zeocin (Invitrogen). Selection media were changed every 2-3 days so as to form the colony. After 3 weeks, clonal selection by picking the colonies was performed for single cell clones.
[0055] The clone with highest EPO productivity was selected by the quantitative assay of secreted EPO concentrations in the supernatant. Quantikine IVD EPO ELISA (Enzyme linked immunosorbent assay) (R&D Systems) was used, and it is based on the double-antibody sandwich method.
EXAMPLE 5
[0000] EPO Assay
[0056] For the quantitative assay of secreted EPO concentrations in the supernatant, Quantikine IVD EPO ELISA (Enzyme linked immunosorbent assay) (R&D Systems Inc., Minneapolis, Minn.) was used, and it is based on the double-antibody sandwich method Each sample containing EPO secreted from recombinant CHO cells was incubated in microplate wells precoated with monoclonal (murine) antibody specific to EPO. EPO binds to the immobilized antibody on the plate, and an anti-EPO polyclonal (rabbit) antibody-HRP (horse radish peroxidase) conjugate binds to this immobilized EPO.
[0057] A chromogen was added into the wells and was oxidized by the enzyme reaction to form a blue colored complex. The reaction was stopped by the addition of acid, which turned the blue to yellow. The amount of color generated is directly proportional to the amount of EPO in the supernatant of production culture. The optical density (O.D.) of each well was determined using a microplate reader (Versamax, Molecular Devices, Sunnyvale, Calif.) set to 450 nm. The EPO concentration was determined by comparing the optical density of the sample to the standard curve. The standards used in this assay were recombinant human EPO calibrated against the Second International Reference Preparation (67/343), a urine-derived form of human EPO.
[0058] FIG. 3 a and FIG. 3 b represent the effect of 30 K protein expression on the EPO production in serum-free medium.
EXAMPLE 6
[0000] EPO Glycosylation Assay Using 2-DE
[0059] Culture supernatants were concentrated (20×) by centrifugal filter units (Milipore) prior to analysis by two-dimensional electrophoresis (2-DE). For analytical gels, samples of concentrated culture supernatant containing 5000 I.U./mL of EPO were combined with rehydration solution (8.0M urea, 2% CHAPS. 0.3% DTT, 0.5% CA, a few grains of bromophenol blue) in a total volume of 200 μL 7 cm pH 3-10 immobilized pH gradient (IPG) gel strip (Amersham Parmacia Biotech) was rehydrated with this solution overnight. JEF was conducted using an IPGphor unit at 20° C. and the voltage was increased stepwise from 250 V (0.5 h to 500 V (1 h), to 1000 V (1 h), than gradually increased to 8000 V (1 h finally maintained at 8000 V (5 h).
[0060] Prior to SDS-PAGE, the LPG gel strips were washed for 15 min in equilibration solution (6.0M urea, 30% glycerol, 2% SDS, 0.05M Tris-HCl) containing 0.1% DTT. This was followed by a 15 min wash in equilibration solution containing 0.25% iodoacetamide. After eqilibration steps, gel strip was loaded on 12% polyacrylamide gel and sealed with 0.5% molten agarose gel.
[0061] Proteins separated by SDS-PAGE were electrophoretically transferred onto PVDF membrane. The membrane was blocked by incubation at 4° C. with 5% skim milk for overnight and then incubated with purified mouse monoclonal anti-human EPO (5 mg/mL) at room temperature for at least 3 h Antibody binding was detected by incubation with 1:30,000 diluted alkaline phosphatase-conjugated goat anti-mouse IgG (Santacruz) for 2 h. Nitriblue tetrazolium (0.3 mg/mL; Sigma) and 5-bromo-4-chloro-3-indolyl phosphate (0.15 mg/ml; Sigma) in 5 mM MgCl2 plus 100 mM Tris Buffer were used as a substrate. The membranes were washed 5 times for 5-10 min with PBS/0.19% Tween20 between each step.
[0062] FIG. 4 is a photograph of two-dimensional electrophoresis of EPO samples. Stable expression of 30Kc6 significantly promoted the terminal sialylation of glycans of EPO and reduced the heterogeneity of the glycoforms as shown by a decreased pI range.
EXAMPLE 7
[0000] Sialic Acid Assay Using Lectin
[0063] To assay the terminal sialylation of EPO glycans, DIG glycans differentiation kit (Roche) was used. The EPO protein was transferred onto PVDF membrane after SDS-PAGE. Membranes were incubated at 4° C. for overnight in 20 mL blocking solution, and then incubated with 50 μL MAA (Maackia amurensis agglutinin) lectin at room temperature for 1 h. Lectin binding was detected by incubation with anti-digaxigenin-alkaline phosphatase for 1 h. Nitriblue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate in 5 mM MgCl2 plus 100 mM Tris Buffer were used as a substrate. The membranes were washed 5 times for 5-10 min with TBS buffer (pH 7.5).
[0064] FIG. 5 is a photograph of lectin binding assay of EPO samples. Stable expression of 30Kc6 significantly promoted the terminal sialylation of glycans of EPO as shown by a increased MAA lectin binding.
[0065] While the present invention has been described with reference to particular examples thereof, there can be various modifications on the basis of the spirit of the present invention. | The present invention relates to a CHO (Chinese hamster ovary) cell line transfected with 30 K gene. More particularly, the present invention is directed to a CHO cell line transfected with 30 K genes obtained from the silkworm Bombyx Mori , which has anti-apoptotic property. | 2 |
FIELD OF THE INVENTION
The present invention relates to vibratory screening or diagnostic tools that may be used, for example, to measure sensory disturbances such as carpal tunnel syndrome (CTS) and to systems that include such tools.
DESCRIPTION OF RELATED ART
By way of background, attention is called to two journal articles: "Increase of Vibration Threshold During Wrist Flexion in Patients With Carpal Tunnel Syndrome," Borg et al., Pain at p. 211 (1986); "Digital Vibrogram: A New Diagnostic Tool for Sensory Testing in Compression Neuropathy," Lundborg et al., The Journal of Hand Surgery, at p. 693 (1986). In the references of these two articles there are further articles noted later herein: Dellon (1980); Gelberman (1980); Moberg (1966); Gelberman et al. (1983).
Muscles, nerves, tendons, and joints are all susceptible to fatigue when repetitive motion is required. Symptoms include numbness, aching, inflammation, and loss of skin color. One area of particular concern--and the disturbance emphasized herein--is the carpal tunnel, a section of the wrist through which a number of tendons move in their sheaths. Twisting, hyperextension and related conditions can cause a pinching of the tendons and/or nerves associated with this congested area of the hand and wrist. This is commonly referred to as the carpal tunnel syndrome.
Vascular injury can occur when the walls of the blood vessels in the fingers and elsewhere become thicker and constrict, thereby reducing blood flow. When passage becomes blocked and blood fails to flow through the vessels, the skin may turn pale. This is known as white fingers, Raynauds phenomenon, VWF (vibration induced white fingers) or TVD (traumatic vasospastic disease).
Nerve injury can also be induced by excessive vibration. It is often exhibited by an inability to identify two adjacent pressure points acting on the skin of the finger as two separate points and not just one. The sensory threshold is increased for fingers that have been injured by vibration.
High vibration amplitudes (at low frequencies) combined with high feed forces can cause wear on the surfaces of the joints. Likewise, impact can cause microfractures in skeletal bones, thus interfering with the supply of nutrients to the joints and causing pain.
All of the above injuries can be prevented if a noninvasive device existed that could predict the injury to the hands before irreversible damage occurs. In this regard it is necessary to detect early sensory changes in compression neuropathy.
By way of historical review, it is to be noted that Dellon (1980) and Gelberman (1980) found that an increase in the perception threshold for vibration stimuli of the long finger at 256 hertz is the earliest detectable objective sign in patients with CTS. Before this body of work, the two-point discrimination test (2PD) was used as a standardized test for assessing sensory improvement, but in compression neuropathy, changes in two-point discrimination only occurs in advanced nerve lesions (Moberg, 58, 62, 66). Gelberman et al. (1983) used a biothesiometer allowing assessment of perception threshold for vibration with a specific frequency (125 or 256 hertz). Lundborg et al. (1986) hypothesized that to detect early sensory changes in compression neuropathy, assessment of vibration sense of the hand was useful; but an analysis within only one fixed frequency and receptor system, respectively, gave a limited amount of information. Therefore, Lundborg et al. (1986) built an instrument, actually a modified Bekesy audiometer, for use in analyses of vibrotactile sensibility of the hand at frequencies ranging from eight to 500 hertz. They found that changes in the shape of a plot of perception threshold vs. frequency were related to the patients' subjective symptoms.
However, the above Lundborg et al. system appears not to have the necessary interactive measurement circuits to provide a diagnosis. Recent research by the present inventors suggest that six different measurements are required to effect the proper analysis. They are: (1) a plot of the perception threshold of the long finger (of a patient) vs. frequency (8-800 Hz); (2) force on the pulp of the long finger (other fingers or other body parts may be tested) by a vibratory stimulator; (3) uniform pressure of the entire hand of the patient on a vibrotactal measurement platform; (4) angle of the wrist of the patient; (5) finger tip temperature of the long (or other) finger; and (6) the PPG (i.e., pulsed wave graph or monitor). The Lundborg et al. (1986) system measures only (1).
OBJECTIVES
Accordingly, it is a principal objective of the present invention to provide a screening or diagnostic system to measure the extent of sensory disturbances in neuropathies and/or any response to treatment of any such sensory disturbances.
Another objective is to provide a system to measure early occurrence of carpal tunnel syndrome.
These and still further objectives are addressed herein.
SUMMARY OF THE INVENTION
The foregoing objectives are attained, generally, in a system (or method) to sense a body pressure-sensitivity phenomenon of a patient or pressure-related disorder of that patient, that includes a vibratory stimulator to apply controlled and compensated vibratory force to a finger (or other body portion) of the patient; a drive mechanism connected to effect vibration of the vibratory stimulator and operable automatically to effect discrete, but variable, vibrations at many frequencies over a wide range of frequencies and at variable amplitude levels at each vibration frequency; and a response mechanism which permits the patient to record the onset of sensing by the patient of vibrations (that is, the smallest amplitude of vibration sensed) at each discrete vibration frequency. In a preferred embodiment, once vibrations are noted (the onset of sensing) in an up-cycle, i.e., a condition of increasing vibration amplitudes, the vibrations are then decreased, i.e., a down-cycle, until no longer sensed, and that loss of vibration sensing is noted.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is hereinafter discussed with reference to the accompanying drawing in which:
FIG. 1 is a diagrammatic representation of a system to sense a body pressure-sensitivity phenomenon or the like, that includes a vibratory tool, a computer, and a back-pressure monitor;
FIG. 2 is a diagrammatic representation showing in some detail the vibratory tool and the back-pressure monitor;
FIG. 3 is a graphical representation showing sensitivity of a normal patient to vibration of the vibratory tool of a body portion at discrete vibration frequencies over a range of frequencies;
FIG. 4 is an exemplary graphical representation of perceived thresholds of perception for diseased and nondiseased patients with respect to body parts (e.g., carpal tunnel syndrome);
FIG. 5 is a side-view schematic diagram of portions of a vibratory tool and the hand of a patient properly placed for testing;
FIG. 6 is a more detailed side view schematic diagram showing portions of the vibratory tool and back-pressure monitor of FIG. 1, i.e., the electromagnetic vibration amplitude circuit herein; and
FIG. 7 is a schematic representation at the back-pressure monitor of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning first to FIG. 1, there is shown a system 101 to sense a body pressure phenomenon of a patient and/or a pressure-related disorder of the patient. The system 101 includes a computer 102, a printer/display 109, a vibratory screening and diagnostic tool 103, a fingertip skin temperature sensor 104, a pulse wave monitor (PPG) 105, a back-pressure monitor 106 of the measured body part, a base pressure sensor 107 and an extremity angle sensor for CTS measurement 108, and a keyboard 110. The units 103, 104, 105, 106, 107, 108, and 110 provide inputs to the computer 102 which provides control and data inputs to each of the units: thus, the double arrows. For present purposes the tool 103 is considered to have the electrical and mechanical structures shown at 103 in FIG. 2, as later discussed, and later figures.
The tool 103 includes a test surface 1 in FIGS. 5 and 6 to receive the hand 2 of a patient. A vibratory mechanism or probe 3 (that is, the core of a linear, variable, differential transformer) applies a vibratory force to the tip of a finger (labeled 2A in FIG. 5), or other body portion or part of the patient. The pulp of the tip 2A of the finger of the patient extends downward through a hole (or opening) 1A in the test surface 1; the probe 3 (FIG. 6) extends upward into the hole (or opening) 1A to apply an upward force on the pulp of the fingertip 2A. A probe drive functions to provide discrete, but variable, and compensated, vibrations at vibration frequency outputs from the vibratory probe over a wide range of frequencies (e.g., eight to 800 hertz). The probe drive is described below, but, for now, it includes a high-compliance speaker 4 (which may be replaced by a piezoelectric or other driver) and most of the apparatus to the left of the speaker 4 in FIG. 2 (e.g., a function generator 10, timer 11 and amplifier 7). The probe drive is such that the output of the probe 3 is linearized (i.e., the computer 102 on the basis of the feedback information from the back-pressure monitor 106 compensates for differences in force by individual patients upon the probe 3 so that, so far as the system 101 is concerned, each patient applies the same down pressure on the probe 3 over the entire frequency range). An electromagnetic vibration amplitude measurement coil 6 in FIG. 6 is used to determine vibration amplitude and also to determine back pressure on the probe tip 3 (an accelerometer may be used for this purpose). The coil 6 is part of the circuit in the back-pressure sensor of the body part being measured, that is, the block 106 in FIG. 1. The circuit 106 interacts with the computer connection 151C in FIG. 2 which is labeled 153 in FIG. 1) to maintain linearity in the system. (For each vibration amplitude setting the throw would be the same at all frequencies.)
Thus, the probe 3 may be driven at some low frequency, say eight hertz, and at an amplitude below that at which the patient can sense. The amplitude of vibration is increased (i.e., an up-cycle) until it is sensed by the patient, the onset of sensing. At that juncture the patient inputs at 5A in FIG. 2 a control signal to close an analog switch 5 to record the onset of sensing of the probe vibrations at the frequency being checked, here eight hertz. (The threshold is sensed several times in order to establish a zone of sensitivity.) A signal is sent to the computer 102 which is orchestrating the test and the frequency of vibration is increased from some lower value to some new, higher value, f 1 , f 2 , f 3 . . . f n , and the operation is repeated. In this way the onset of incipient level of sensed vibration at each frequency, f 1 , f 2 , . . . f n , is obtained and from this information the body pressure or pressure-related disorder of the patient can be learned or inferred. Both the up-cycle onset of vibration sensing and the down-cycle loss of sensed vibration provide data for body-function evaluation. Of great interest is carpal tunnel syndrome whose early stages are important to note in the context of treatment.
It is of some importance to note, as suggested above, that the threshold or onset of sensing by the patient to an increasing amplitude of vibration (an up-cycle) at each individual vibration frequency of a plurality of vibration frequencies over a range is important for diagnosis purposes. It is also important to note once the onset of vibration is established on the up-cycle, that the lower level of vibration, on the down-cycle, at which sensing of those vibrations is lost, is also important. For, once vibration sensitivity is established in a patient, it has been found for present purposes that the acoustic vibrational level can be reduced and yet the perception of vibration remains with the patient. There is a residual retention. The level of vibration amplitude--after the onset of vibration is noted (e.g., by depressing the switch 5)--is reduced to a lower level (the down-cycle) at which sensing ceases. This lowered level is noted by the patient by releasing the switch 5. Thus, according to this aspect of the invention, the onset of vibration sensing is noted by the patient depressing the switch 5 at each frequency f 1 , f 2 . . . and the loss of sensing, as the vibrating amplitude is decreased is noted by the patient by releasing the switch 5. Both values are important for present purposes.
It is indicated above to be important that the fingertip 2A present about the same downward pressure onto the probe 3 in FIG. 5. For this and other reasons the arm 2B in FIG. 5 of the patient is oriented at an outside obtuse angle θ in FIG. 5 to the hand 2.
The patient is instructed to press the button 5A in FIG. 2 of the hand switch 5 when the vibrations of the probe 3 are first felt, thus causing an automatic attenuator to decrease the intensity (amplitude) and to release the button when the vibrations can no longer be felt. In this way the patients regulate the intensity (amplitude) of the vibrations, thereby tracking their threshold level. Since the frequency of the stimuli is automatically changed through the frequency range from eight hertz to 800 hertz, the perception threshold within this frequency range can be recorded. As noted above, simultaneously real PPG data can be seen at 109. A readout at 109 can also show pulse rate and skin temperature, finger back pressure, base pressure, and wrist angle.
The main elements of the tool 103 are the high compliance speaker 4 driven by an amplifier 7 in FIG. 2. A magnetic post 3 is mounted/glued to the top of the speaker cone 4. The amplifier 7 linearizes the response of the system so that each individual is allowed to sense the same vibration at each frequency. The rest of the system consists of a function generator chip 10 in FIG. 2, a counter/timer 11, the analog switch 5, and a few bias amplifiers. A graphical printer 109 displays vibratory information in plot form as well as table form. The label 10A in FIG. 2 designates a circuit which controls the rate of rise and fall for the onset of vibration amplitude and the reduction in the amplitude.
The probe 3, then, is vibrated at frequencies f 1 . . . f n , e.g., 8 . . . 800 hertz. At each frequency 8, 16 . . . the probe starts with a force on the fingertip of zero (no initial contact); the computer 102 through the circuit 103 (see connection 151 in FIG. 1) increases the amplitude of vibration to a value at which the patient senses the vibration. Typically a cycle at each frequency is ten seconds. Each set of vibrations, it will be understood, is about an average value at each amplitude level. Taking 8 hertz as an example, the computer 102 may cause the probe 3 to vibrate in an up-cycle at level L, for one second or eight vibrations, at level L 2 for one second . . . until level L n at which the vibrational force is sensed by the patient. At that juncture the patient closes the switch 5 and the computer systematically causes the vibratory pressure to decrease in a down-cycle. Meanwhile the patient keeps the switch 5 closed, until the sensing of vibration is lost; the switch 5 is then opened, beginning another up-cycle. Typically, there may be three up-cycles and three down-cycles at 8 hertz. The computer then repeats the process at 16 hertz, and so forth, up to, say, 800 hertz, but usually less. The number of frequencies f 1 , f 2 . . . and the duration of each frequency are controlled and controllable by the computer 102.
It will be understood by workers in this art that the vibrations represented by the graph in FIG. 3 do not, then, proceed immediately from zero amplitude to the vibration amplitude at the onset of sensing, as shown, but, rather, there are intermediate vibrations, undetected by the patient. The graph shows only the detected vibration level at each frequency of the range of frequencies, for this is what is important, as is the average trend, as denoted in FIG. 4, of amplitude between the upper vibration level (on the up-cycle) and the lower vibration level (on the down-cycle) at each frequency.
FIG. 4 shows how perceived thresholds can be used to diagnose diseased or non-diseased patients, such as carpal tunnel syndrome. Patient C senses a wider range of frequencies at a constant vibration amplitude than does patient A. Patient C is non-diseased; Patient A is diseased.
Turning to the back pressure circuit 106 in FIGS. 1 and 7, it includes a programmable amplifier 13 and resistors R 1 and R 2 . Its function is to compensate for mechanical bias applied to the end 3A of the probe 3 (FIG. 7) by a patient: patients will apply forces upon the probe 3 that vary from patient to patient and, as a function of time, even with the same patient. In the context of this specification, the circuit 106 includes the probe 3 and the coil 6. In the context of this explanation, feedback signals are applied at 160 from the coil 6 to the remaining circuitry in the circuit 106 and to the computer 102 (connection 151C). The circuit 106, on the basis of these feedback signals, compensates for the bias applied to the probe 3 by the patient to ensure that amplitude of vibration by the probe 3 to the finger tip 2A is the same for each patient as the vibrator tool 103 scans the frequencies f 1 . . . f n . The term "compensate" and variations thereof, as used herein, means compensation with respect to vibrations of the amplitude of the probe 3 at each frequency f 1 . . . to take into consideration, or compensate for, bias forces above or below some expected or average force by the patient.
A few matters touched on above are included in this paragraph. The computer 102 controls administration of the probe 3 to the patient and analysis of information received from the response recording devices 106, 107, 108, and the keyboard 110 (along connection 152, FIG. 1) provide feedback and other information to the computer 102. The feedback and other signals representing temperature (from the sensor 104) and the pulse wave monitor (PPG) 105 are used by the computer which is programmed to recalibrate and compensate respectively for temperatures of the fingertip that vary from an established standard and any functional vascular disorder of the patient. This latter technology is discussed at pp. 427 et seq. under the heading Photoplethysmography in Medical Instrumentation (Webster).
The connections 151A, 151B, 151D and 151E from the computer 102 are respectively to the function generator 10 (FIG. 2) to generate frequencies f 1 -f n , the amplifier 7 to amplify the signal out of the function generator 10 to drive the speaker 4, the timer 11 to control the timing of the sequence of test steps and the rate of change circuit 10A to control the rate at which vibration amplitude increases (or decreases) from some rate to a next different rate; the feedback signal at 151C to the computer 102 to provide information to enable the computer to provide compensation for back pressure.
The foregoing and further modifications of the invention will occur to persons skilled in the art and all such modifications are deemed to be within the scope of the invention as defined by the appended claims. | A method of (and apparatus for) diagnosing a patient to measure sensory disturbances of the patient that includes the steps of applying normalized vibrator forces to a body portion or part (e.g., the finger) of the patient; automatically effecting discrete, but variable, vibrations of the body portion over a wide range of frequencies and at various vibratory amplitude levels at each vibration frequency; and noting the onset of sensory perception by the patient on an up-cycle at each vibration frequency and correlating the information, so derived, with the physical condition of the body portion or part. The method contemplates, once the onset of vibratory perception is achieved, in an up-cycle, decreasing the amplitude of vibration at each vibration frequency until the patient ceases or fails to sense the vibration and, in part, correlating the lower level of sensory perception to the condition of the body portion or part. | 0 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to the fabrication of integrated circuit devices, and more particularly, to a method for the enhancement of Low Pressure Chemical Vapor Deposition (LPCVD).
(2) Description of the related Prior Art
The process of Chemical Vapor Deposition (CVD) is widely applied and well known in the art of creating semiconductor devices and it explained in detail in for instance the text Silicon Processing for the VLSI Era, Volume 1, by Stanley Wolf and Rickard N. Tauber, published by the Lattice Press. From this source the process and its salient features are briefly highlighted.
The CVD process can be summarized as consisting of the following sequence of steps:
a given composition and flow rate of reactant gasses and diluent inert gasses is introduced into a reaction chamber
the gas species move to the substrate
the reactants are absorbed on the substrate
the adatoms undergo migration and film-forming chemical reactions, and
the gaseous by-products of the reaction are de-sorbed and removed from the reaction chamber.
Energy to drive the reactions can be supplied by several methods such as thermal, photons or electrons, with thermal energy being the most frequently form of energy.
In practice, the chemical reactions of the reactant gasses leading to the formation of a solid material may take place not only on or very close to the surface of the wafers a so-called heterogeneous reaction, but can also take place in the gas phase, a so-called homogeneous reaction. Heterogeneous reactions are much more desirable since such reactions occur selectively only on heated surfaces and are known to produce good quality films of semiconductor material. Homogeneous reactions in the other hand are undesirable since these reactions form gas phase clusters of the depositing material, which can result in poorly adhering, low density films or in defects in the depositing film. In addition, such reactions also consume reactants and can cause a decrease in deposition rates. Thus, one important characteristic of a CVD process is the degree to which heterogeneous reactions are favored over gas phase reactions.
One of the key aspects and concerns of applying CVD processes is the uniformity with which the semiconductor material is deposited over the surface of a wafer, a concern that is further emphasized by the increased size of semiconductor wafers that are being used for the creation of semiconductor devices. A value of concentration gradient can be used in this respect, which is indicative of the amount of semiconductor material that is deposited over a unit of surface. Because of the impact of the concentration gradient, it has been found that the semiconductor material is deposited thinner in the center of the wafer than the average of the deposition thickness over the complete surface of the wafer. For the same reason, it has been found that the deposited material is thicker around the perimeter of the wafer than the average of the deposition thickness over the surface of the wafer. The variation of the concentration gradient of the deposition across the surface of a wafer leads to poor uniformity of the deposited material across the surface of the substrate.
Extreme uniformity of the deposited material over a semiconductor surface is required in order to achieve uniformity of the devices that are created using the entire surface of the wafer. With increased wafer size, this uniformity is more difficult to achieve and to maintain. The invention provides a method that addresses this concern.
U.S. Pat. No. 4,992,044 (Pillipossian) shows an LPCVD furnace with improved within wafer uniformity.
U.S. Pat. No. 5,976,990 (Mercaldi et al.) discloses a LPCVD SiN process.
U.S. Pat. No. 4,851,370 (Doklan et al.) shows a LPCVD SiN process.
U.S. Pat. No. 4,888,142 (Hayashi) and U.S. Pat. No. 4,395,438 (Chiang) are related patents.
SUMMARY OF THE INVENTION
A principle objective of the invention is to provide a method for enhanced uniformity of deposited layers over a semiconductor surface.
It is another objective of the invention to eliminate a temperature variation or gradient between the center of the substrate and the perimeter of the substrate during the process of CVD.
It is yet another objective of the invention to offset the conventional difference in temperature between the center of the substrate and the perimeter of the substrate during CVD processing, where conventionally the edge of the temperature will be elevated to a lower temperature than the center of the substrate.
It is a further objective of the invention to eliminate the effect that the temperature gradient has on the deposition rate of CVD deposited semiconductor material, by reducing the deposition rate of the semiconductor material when proceeding toward the perimeter of the substrate.
In accordance with the objectives of the invention a new method is provided for the application of Chemical Vapor Deposition (CVD) processes. Where conventional CVD processes are performed while maintaining one, constant temperature during the CVD process, from the start of the CVD process up to the point where the CVD process is completed, the invention provides for first raising the temperature to a processing temperature and then gradually reducing the applied temperature within the cycle time that is required for the completion of the CVD process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the cross section of the surface of a substrate over the surface of which conventionally is deposited a layer of semiconductor material using CVD processing.
FIG. 2 shows a temperature profile that is in force during conventionally CVD processing.
FIG. 3 shows a temperature profile of the invention that is in force during CVD processing.
FIGS. 4 a and 4 b show comparative cross sections of the surface of a substrate over the surface of which, FIG. 4 a , conventionally is deposited a layer of semiconductor material using CVD processing and, FIG. 4 b , over which is deposited a layer of semiconductor material using CVD processing in accordance with the invention.
FIGS. 5 a and 5 b show experimental results in support of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described in detail using FIGS. 3, FIG. 4 b and FIGS. 5 a and 5 b . Prior art methods have been highlighted in FIGS. 1, 2 and 4 a.
Referring first specifically to FIG. 1, there is shown a cross section of a silicon substrate 10 over the surface of which a layer 12 of semiconductor material has been deposited. From the cross section that is shown in FIG. 1 it is clear that the surface of the deposited layer 12 shows a significant degree of dishing. That is the deposited layer 12 of semiconductor material is considerably thinner in the center 14 of the substrate 10 than around the perimeter 16 of the substrate 10 .
As a material used for the creation of layer 12 can be considered any of the conventionally CVD deposited materials that are typically applied for the creation of semiconductor devices, such as silicon nitride, tetra-ethyl-ortho-silicate (TEOS), doped or undoped polysilicon, High Temperature Oxide (HTO) and the like.
The invention specifically addresses the deposition of a layer of silicon nitride, deposited using methods of CVD. As an example of such a deposition of a layer of silicon nitride can be cited depositing a layer of silicon nitride using LPCVD or PECVD procedures, at a temperature between about 200 and 800 degrees C., to a thickness between about 200 and 5,000 Angstrom.
The deposition rate or the previously introduced concentration gradient in the center of the substrate 10 is considerably lower in the center 14 of the substrate than the deposition rate or concentration gradient of the deposited layer 12 around the perimeter 16 of the substrate 10 . This difference in deposition rate prevents the creation of a layer of semiconductor material of good uniformity over the surface of substrate 10 , preventing uniform and identical creation of semiconductor devices over the surface of the substrate.
Conventional methods that are used for the CVD deposition of layer 12 , FIG. 1, use a constant temperature, which is the temperature that is for various reasons considered the optimum temperature for the deposition of layer 12 . This is highlighted in FIG. 2, which shows a first temperature Temp-1, which is typically an environmental temperature, and a second temperature Temp-2. The Temp-2 is the temperature to which the substrate is raised during the time of CVD deposition of a layer of semiconductor material. It must be noted that Temp-2 remains in force during the CVD deposition of a layer of semiconductor material over the surface of a substrate, this value remains in force until the process of CVD has been completed after which the elevated temperature is allowed to return to Temp-1.
FIG. 3 is a pictorial representation of the process of the invention, whereby the temperature of the substrate is, during the process of CVD, no longer held at one constant value but is varied. The objective of the temperature variation of the invention is to:
1. eliminate a temperature variation or gradient between the center of the substrate and the perimeter of the substrate
2. to offset the conventional difference in temperature between the center of the substrate and the perimeter of the substrate, where conventionally the edge of the temperature will be elevated to a lower temperature than the center of the substrate, and
3. eliminate the effect that the temperature gradient has on the deposition rate of the deposited semiconductor material by reducing the deposition rate of the semiconductor material when proceeding toward the perimeter of the substrate.
The depiction that is shown in FIG. 3 conveys the highlighted principles by showing a temperature curve that first is raised from a value of Temp-1 to a value of Temp-2, after which the temperature is maintained at a constant value of Temp-2 for a period 11 of time.
The time during which the CVD process is performed is plotted along the horizontal or X-axis, the temperature of the wafer over the surface of which the CVD process is applied is plotted-along the vertical or Y-axis.
After the time 11 has expired, the temperature is gradually reduced, time period 13 , to the point where the CVD process is completed. At that point the temperature is allowed to return to the value Temp-1.
The improvement that can be obtained using the principles that have been highlighted in FIG. 3 are shown in the cross sections of FIGS. 4 a and 4 b . FIG. 4 a represents the conventional method of performing a CVD process while the cross section of FIG. 4 b represents a CVD process in accordance with the invention. In comparing the two cross sections that are shown in FIGS. 4 a and 4 b it is clear that the deposited layer 18 of FIG. 4 a has a considerable amount of dishing, which is much more pronounced than the amount of dishing that is observed in the cross section of FIG. 4 b . This difference in the amount of dishing between FIG. 4 a and FIG. 4 b is representative of the improvement that is obtained by the invention by controlling the temperature gradient over the surface of the substrate.
The concept of the invention has further been experimentally verified by creating a layer of silicon nitride (Si 3 Ni 4 ) over the surface of a substrate applying two deposition sequences, the first sequence being a conventional method without temperature ramp-down, the second being the sequence of the invention by using temperature ramp-down during the CVD process. The thickness of the deposited layer of Si 3 Ni 4 was 1,625 Angstrom, deposited at a temperature of 780 degrees C. using a standard CVD deposition furnace and procedure.
For the standard or conventional CVD, the time of deposition was set at 1 hour and 38 minutes.
For the CVD of the invention, the processing temperature of 780 degrees C. was maintained for 1 hour and 12 minutes after which the temperature of the substrate was ramped-down from 780 degrees C. to 720 degrees C. over an elapsed time-span of 30, that is at a ramp-down rate of 2 degrees C./min.
For this experiment, seven wafers were used mounted within a tube comprising seven wafer positions, the wafers being referred to with a sequential wafer number of #1 through #7. The below indicated value of Std is the measured difference of the thickness of the deposited layer of Si 3 Ni 4 between the perimeter of the substrate and the center of the substrate. For instance, a value of Std=20.38 indicates that the layer of Si 3 Ni 4 was deposited at the perimeter of the substrate with a thickness that exceeded the thickness of the deposited layer of Si 3 Ni 4 in the center of the substrate by 20.38 Angstrom. The first two rows of the below listed table represent the standard CVD process, the second two rows represent the process of the invention in which temperature ramp-down is used, as indicated above.
Wafer
#1
#2
#3
#4
#5
#6
#7
Standard
Thickness
1614
1616
1619
1621
1626
1641
1594
CVD
Std
20.38
18.45
15.40
15.63
15.60
16.06
25.41
Ramp-
Thickness
1621
1609
1610
1618
1646
1675
1624
down
Std
14.13
14.15
12.87
13.46
14.73
17.63
23.83
CVD
It can be observed from the above highlighted experimental data that the value Std, the difference in thickness between the deposited layer of silicon nitride in the perimeter of the substrate and the center of the substrate, is smaller using the ramp-down method of deposition for every substrate #1 through #7 that was part of the experimental verification.
From this it may be concluded that the invention, by not maintaining the process temperature at one constant value for the full duration of the CVD based creation of a layer of semiconductor material and by ramping-down the temperature of the substrate at a selected point during the CVD based creation of a layer of semiconductor material, has improved the uniformity of the deposition of the layer of semiconductor material.
This is further confirmed by the curves that are shown in FIG. 5 a . Curve a, FIG. 5 a , shows the measured Deposition Uniformity (plotted along the vertical or Y-axis) of deposition of a layer of 1,625 Angstrom of silicon nitride for three different zones U (upper zone), C (center zone) and L (lower zone) within a CVD deposition furnace. The zones of the CVD furnace are plotted along the horizontal or X-axis. The two curves represent both the conventional or standard method of creating the layer of silicon nitride (curve a) and the method of the invention (curve “b”). Curve “b” (representing the CVD method of the invention) is located below curve “a” (representing the conventional method of CVD deposition) for all of the zones U, C and L of the CVD chamber. Lower values of the difference in deposition uniformity (plotted along the Y-axis) represent improved deposition uniformity over the surface of the substrate for each of the zones (plotted along the X-axis) of the CVD furnace. The uniformity of deposition has been increased for each of these zones.
This latter finding is further confirmed by the numerical values of the parameter U (uniformity of deposition) that are shown in FIG. 5 b for the three surface areas U, C and L.
It must further be pointed out that the invention is not limited to a linear reduction in processing temperature or that only one instance of temperature variation may be applied. The total processing time that is required for the completion of a LPCVD process can be sub-divided into multiple time interval. During each of these time intervals the applied temperature may be varied, a variation that may follow a linear variation of temperature versus time or a time variation that may follow a geometric dependency between temperature and processing time.
The invention, of performing a process of Low Pressure Chemical Vapor Deposition (LPCVD), can therefore be summarized as follows:
providing at least one substrate
providing a Low Pressure Chemical Vapor Deposition (LPCVD) processing chamber
preparing the Low Pressure Chemical Vapor Deposition (LPCVD) chamber for processing the at least one substrate by establishing operational processing conditions for the LPCVD processing chamber, the operational processing conditions comprising a first processing temperature in addition to other processing conditions, the operational processing conditions further comprising a processing time, the operational processing conditions further comprising a total processing time being the time that is required for completion of LPCVD processing of the at least one substrate
positioning the at least one substrate inside the LPCVD processing chamber
first LPCVD processing the at least one substrate during a first sub-period of the total processing time, thereby maintaining the other operational processing conditions of the LPCVD processing chamber, thereby specifically maintaining the first processing temperature
second LPCVD processing the at least one substrate as a continuation of the first LPCVD processing over a second sub-period of the total processing time, thereby maintaining the other operational processing conditions of the LPCVD processing chamber while reducing the first processing temperature, the second sub-period of the total processing time increased by the first sub-period of the total processing time being equal to the total processing time
terminating the LPCVD processing of the at least on wafer at termination of the second sub-period of the total processing time by discontinuing the other processing conditions for the LPCVD processing chamber, and
removing the at least one substrate from the LPCVD processing chamber.
The invention, of performing a process of low Pressure Chemical Vapor Deposition (LPCVD), can alternately be summarized as follows:
providing at least one substrate
providing a Low Pressure Chemical Vapor Deposition (LPCVD) processing chamber
preparing the Low Pressure Chemical Vapor Deposition (LPCVD) chamber for processing the at least one substrate by establishing operational processing conditions for the LPCVD processing chamber, the operational processing conditions comprising a multiplicity of processing temperatures in addition to other processing conditions, the other processing conditions being valid during a total processing time being the time that is required for completion of LPCVD processing of the at least one substrate, the total processing time comprising a multiplicity of processing time intervals which when added comprise the total processing time, processing time within the multiplicity of processing time intervals being recognized as within interval processing time, the multiplicity of processing temperatures being related to the within interval processing time by an interval equation for each of the multiplicity of processing time intervals
positioning the at least one substrate inside the LPCVD processing chamber
LPCVD processing the at least one substrate in accordance with the interval equation, thereby maintaining the other operational processing conditions of the LPCVD processing chamber
terminating the LPCVD processing of the at least on wafer at termination of the total processing time by terminating the other operational processing conditions for the LPCVD processing chamber, and
removing the at least one substrate from the LPCVD processing chamber.
Although the invention has been described and illustrated with reference to specific illustrative embodiments thereof, it is not intended that the invention be limited to those illustrative embodiments. Those skilled in the art will recognize that variations and modifications can be made without departing from the spirit of the invention. It is therefore intended to include within the invention all such variations and modifications which fall within the scope of the appended claims and equivalents thereof. | A new method is provided for the application of Chemical Vapor Deposition (CVD) processes. Where conventional CVD processes are performed while maintaining one, constant temperature during the CVD process, from the start of the CVD process up to the point where the CVD process is completed, the invention provides for first raising the temperature to a processing temperature and then gradually reducing the applied temperature within the cycle time that is required for the completion of the CVD process. | 2 |
This application is a continuation of U.S. patent application Ser. No. 09/008,945, filed Jan. 20, 1998, now U.S. Pat. No. 6,730,298, which is a continuation of U.S. patent application Ser. No. 08/056,140, filed Apr. 30, 1993 and issued as U.S. Pat. No. 5,709,854, all of the above being incorporated herein in their entirety by reference.
BACKGROUND OF THE INVENTION
The present invention is generally in the area of creating new tissues using polysaccharide hydrogel-cell compositions.
Craniofacial contour deformities, whether traumatic, congenital, or aesthetic, currently require invasive surgical techniques for correction. Furthermore, deformities requiring augmentation often necessitate the use of alloplastic prostheses which suffer from problems of infection and extrusion. A minimally invasive method of delivering additional autogenous cartilage or bone to the craniofacial skeleton would minimize surgical trauma and eliminate the need for alloplastic prostheses. If one could transplant via injection and cause to engraft large numbers of isolated cells, one could augment the craniofacial osteo-cartilaginous skeleton with autogenous tissue, but without extensive surgery.
Unfortunately, attempts to inject dissociated cells subcutaneously or to implant dissociated tissues within areas of the body such as the peritoneum have not been successful. Cells are relatively quickly removed, presumably by phagocytosis and cell death.
Cells can be implanted onto a polymeric matrix and implanted to form a cartilaginous structure, as described in U.S. Pat. No. 5,041,138 to Vacanti, et al., but this requires surgical implantation of the matrix and shaping of the matrix prior to implantation to form a desired anatomical structure.
Accordingly, it is an object of the present invention to provide a method and compositions for injection of cells to form cellular tissues and cartilaginous structures.
It is a further object of the invention to provide compositions to form cellular tissues and cartilaginous structures including non-cellular material which will degrade and be removed to leave tissue or cartilage that is histologically and chemically the same as naturally produced tissue or cartilage.
Summary of the Invention
Slowly polymerizing, biocompatible, biodegradable hydrogels have been demonstrated to be useful as a means of delivering large numbers of isolated cells into a patient to create an organ equivalent or tissue such as cartilage. The gels promote engraftment and provide three dimensional templates for new cell growth. The resulting tissue is similar in composition and histology to naturally occurring tissue. In one embodiment, cells are suspended in a hydrogel solution and injected directly into a site in a patient, where the hydrogel hardens into a matrix having cells dispersed therein. In a second embodiment, cells are suspended in a hydrogel solution which is poured or injected into a mold having a desired anatomical shape, then hardened to form a matrix having cells dispersed therein which can be be implanted into a patient. Ultimately, the hydrogel degrades, leaving only the resulting tissue.
This method can be used for a variety of reconstructive procedures, including custom molding of cell implants to reconstruct three dimensional tissue defects, as well as implantation of tissues generally.
DETAILED DESCRIPTION OF THE INVENTION
Techniques of tissue engineering employing biocompatible polymer scaffolds hold promise as a means of creating alternatives to prosthetic materials currently used in craniomaxillofacial surgery, as well as formation of organ equivalents to replaced diseased, defective, or injured tissues. However, polymers used to create these scaffolds, such as polylactic acid, polyorthoesters, and polyanhydrides, are difficult to mold and hydrophobic, resulting in poor cell attachment. Moreover, all manipulations of the polymers must be performed prior to implantation of the polymeric material.
Calcium alginate and certain other polymers can form ionic hydrogels which are malleable and can be used to encapsulate cells. In the preferred embodiment described herein, the hydrogel is produced by cross-linking the anionic salt of alginic acid, a carbohydrate polymer isolated from seaweed, with calcium cations, whose strength increases with either increasing concentrations of calcium ions or alginate. The alginate solution is mixed with the cells to be implanted to form an alginate suspension. Then, in one embodiment, the suspension is injected directly into a patient prior to hardening of the suspension. The suspension then hardens over a short period of time. In a second embodiment, the suspension is injected or poured into a mold, where it hardens to form a desired anatomical shape having cells dispersed therein.
Polymeric Materials.
The polymeric material which is mixed with cells for implantation into the body should form a hydrogel. A hydrogel is defined as a substance formed when an organic polymer (natural or synthetic) is cross-linked via covalent, ionic, or hydrogen bonds to create a three-dimensional open-lattice structure which entraps water molecules to form a gel. Examples of materials which can be used to form a hydrogel include polysaccharides such as alginate, polyphosphazines, and polyacrylates, which are crosslinked ionically, or block copolymers such as Pluronics™ or Tetronics™, polyethylene oxide-polypropylene glycol block copolymers which are crosslinked by temperature or pH, respectively.
In general, these polymers are at least partially soluble in aqueous solutions, such as water, buffered salt solutions, or aqueous alcohol solutions, that have charged side groups, or a monovalent ionic salt thereof. Examples of polymers with acidic side groups that can be reacted with cations are poly(phosphazenes), poly(acrylic acids), poly(methacrylic acids), copolymers of acrylic acid and methacrylic acid, poly(vinyl acetate), and sulfonated polymers, such as sulfonated polystyrene. Copolymers having acidic side groups formed by reaction of acrylic or methacrylic acid and vinyl ether monomers or polymers can also be used. Examples of acidic groups are carboxylic acid groups, sulfonic acid groups, halogenated (preferably fluorinated) alcohol groups, phenolic OH groups, and acidic OH groups.
Examples of polymers with basic side groups that can be reacted with anions are poly(vinyl amines), poly(vinyl pyridine), poly(vinyl imidazole), and some imino substituted polyphosphazenes. The ammonium or quaternary salt of the polymers can also be formed from the backbone nitrogens or pendant imino groups. Examples of basic side groups are amino and imino groups.
Alginate can be ionically cross-linked with divalent cations, in water, at room temperature, to form a hydrogel matrix. Due to these mild conditions, alginate has been the most commonly used polymer for hybridoma cell encapsulation, as described, for example, in U.S. Pat. No. 4,352,883 to Lim. In the Lim process, an aqueous solution containing the biological materials to be encapsulated is suspended in a solution of a water soluble polymer, the suspension is formed into droplets which are configured into discrete microcapsules by contact with multivalent cations, then the surface of the microcapsules is crosslinked with polyamino acids to form a semipermeable membrane around the encapsulated materials.
Polyphosphazenes are polymers with backbones consisting of nitrogen and phosphorous separated by alternating single and double bonds. Each phosphorous atom is covalently bonded to two side chains (“R”). The repeat unit in polyphosphazenes has the general structure (1):
where n is an integer.
The polyphosphazenes suitable for cross-linking have a majority of side chain groups which are acidic and capable of forming salt bridges with di- or trivalent cations. Examples of preferred acidic side groups are carboxylic acid groups and sulfonic acid groups. Hydrolytically stable polyphosphazenes are formed of monomers having carboxylic acid side groups that are crosslinked by divalent or trivalent cations such as Ca 2+ or Al 3+ . Polymers can be synthesized that degrade by hydrolysis by incorporating monomers having imidazole, amino acid ester, or glycerol side groups. For example, a polyanionic poly[bis(carboxylatophenoxy)]phosphazene (PCPP) can be synthesized, which is cross-linked with dissolved multivalent cations in aqueous media at room temperature or below to form hydrogel matrices.
Bioerodible polyphosphazines have at least two differing types of side chains, acidic side groups capable of forming salt bridges with multivalent cations, and side groups that hydrolyze under in vivo conditions, e.g., imidazole groups, amino acid esters, glycerol and glucosyl. The term bioerodible or biodegrable, as used herein, means a polymer that dissolves or degrades within a period that is acceptable in the desired application (usually in vivo therapy), less than about five years and most preferably less than about one year, once exposed to a physiological solution of pH 6-8 having a temperature of between about 25° C. and 38° C. Hydrolysis of the side chain results in erosion of the polymer. Examples of hydrolyzing side chains are unsubstituted and substituted imidizoles and amino acid esters in which the group is bonded to the phosphorous atom through an amino linkage (polyphosphazene polymers in which both R groups are attached in this manner are known as polyaminophosphazenes). For polyimidazolephosphazenes, some of the “R” groups on the polyphosphazene backbone are imidazole rings, attached to phosphorous in the backbone through a ring nitrogen atom. Other “R” groups can be organic residues that do not participate in hydrolysis, such as methyl phenoxy groups or other groups shown in the scientific paper of Allcock, et al., Macromolecule 10:824-830 (1977).
Methods for synthesis and the analysis of various types of polyphosphazenes are described by Allcock, H. R.; et al., Inorg. Chem. 11, 2584 (1972); Allcock, et al., Macromolecules 16, 715 (1983); Allcock, et al., Macromolecules 19, 1508 (1986); Allcock, et al., Biomaterials, 19, 500 (1988); Allcock, et al., Macromolecules 21, 1980 (1988); Allcock, et al., Inorg. Chem. 21(2), 515-521 (1982); Allcock, et al., Macromolecules 22, 75 (1989); U.S. Pat. Nos. 4,440,921, 4,495,174 and 4,880,622 to Allcock, et al.; U.S. Pat. No. 4,946,938 to Magill, et al.; and Grolleman, et al., J. Controlled Release 3, 143 (1986), the teachings of which are specifically incorporated herein by reference.
Methods for the synthesis of the other polymers described above are known to those skilled in the art. See, for example Concise Encyclopedia of Polymer Science and Polymeric Amines and Ammonium Salts , E. Goethals, editor (Pergamen Press, Elmsford, N.Y. 1980). Many polymers, such as poly(acrylic acid), are commercially available.
The water soluble polymer with charged side groups is crosslinked by reacting the polymer with an aqueous solution containing multivalent ions of the opposite charge, either multivalent cations if the polymer has acidic side groups or multivalent anions if the polymer has basic side groups. The preferred cations for cross-linking of the polymers with acidic side groups to form a hydrogel are divalent and trivalent cations such as copper, calcium, aluminum, magnesium, strontium, barium, and tin, although di-, tri- or tetra-functional organic cations such as alkylammonium salts, e.g., R 3 N + —\ /\ /\ /— + NR 3 can also be used. Aqueous solutions of the salts of these cations are added to the polymers to form soft, highly swollen hydrogels and membranes. The higher the concentration of cation, or the higher the valence, the greater the degree of cross-linking of the polymer. Concentrations from as low as 0.005 M have been demonstrated to cross-link the polymer. Higher concentrations are limited by the solubility of the salt.
The preferred anions for cross-linking of the polymers to form a hydrogel are divalent and trivalent anions such as low molecular weight dicarboxylic acids, for example, terepthalic acid, sulfate ions and carbonate ions. Aqueous solutions of the salts of these anions are added to the polymers to form soft, highly swollen hydrogels and membranes, as described with respect to cations.
A variety of polycations can be used to complex and thereby stabilize the polymer hydrogel into a semi-permeable surface membrane. Examples of materials that can be used include polymers having basic reactive groups such as amine or imine groups, having a preferred molecular weight between 3,000 and 100,000, such as polyethylenimine and polylysine. These are commercially available. One polycation is poly(L-lysine); examples of synthetic polyamines are: polyethyleneimine, poly(vinylamine), and poly(allyl amine). There are also natural polycations such as the polysaccharide, chitosan.
Polyanions that can be used to form a semi-permeable membrane by reaction with basic surface groups on the polymer hydrogel include polymers and copolymers of acrylic acid, methacrylic acid, and other derivatives of acrylic acid, polymers with pendant SO 3 H groups such as sulfonated polystyrene, and polystyrene with carboxylic acid groups.
Sources of Cells.
Cells can be obtained directed from a donor, from cell culture of cells from a donor, or from established cell culture lines. In the preferred embodiments, cells are obtained directly from a donor, washed and implanted directly in combination with the polymeric material. The cells are cultured using techniques known to those skilled in the art of tissue culture.
Cell attachment and viability can be assessed using scanning electron microscopy, histology, and quantitative assessment with radioisotopes. The function of the implanted cells can be determined using a combination of the above-techniques and functional assays. For example, in the case of hepatocytes, in vivo liver function studies can be performed by placing a cannula into the recipient's common bile duct. Bile can then be collected in increments. Bile pigments can be analyzed by high pressure liquid chromatography looking for underivatized tetrapyrroles or by thin layer chromatography after being converted to azodipyrroles by reaction with diazotized azodipyrroles ethylanthranilate either with or without treatment with P-glucuronidase. Diconjugated and monoconjugated bilirubin can also be determined by thin layer chromatography after alkalinemethanolysis of conjugated bile pigments. In general, as the number of functioning transplanted hepatocytes increases, the levels of conjugated bilirubin will increase. Simple liver function tests can also be done on blood samples, such as albumin production. Analogous organ function studies can be conducted using techniques known to those skilled in the art, as required to determine the extent of cell function after implantation. For example, islet cells of the pancreas may be delivered in a similar fashion to that specifically used to implant hepatocytes, to achieve glucose regulation by appropriate secretion of insulin to cure diabetes. Other endocrine tissues can also be implanted. Studies using labelled glucose as well as studies using protein assays can be performed to quantitate cell mass on the polymer scaffolds. These studies of cell mass can then be correlated with cell functional studies to determine what the appropriate cell mass is. In the case of chondrocytes, function is defined as providing appropriate structural support for the surrounding attached tissues.
This technique can be used to provide multiple cell types, including genetically altered cells, within a three-dimensional scaffolding for the efficient transfer of large number of cells and the promotion of transplant engraftment for the purpose of creating a new tissue or tissue equivalent. It can also be used for immunoprotection of cell transplants while a new tissue or tissue equivalent is growing by excluding the host immune system.
Examples of cells which can be implanted as described herein include chondrocytes and other cells that form cartilage, osteoblasts and other cells that form bone, muscle cells, fibroblasts, and organ cells. As used herein, “organ cells” includes hepatocytes, islet cells, cells of intestinal origin, cells derived from the kidney, and other cells acting primarily to synthesize and secret, or to metabolize materials.
Addition of Biologically Active Materials to the Hydrogel.
The polymeric matrix can be combined with humoral factors to promote cell transplantation and engraftment. For example, the polymeric matrix can be combined with angiogenic factors, antibiotics, antiinflammatories, growth factors, compounds which induce differentiation, and other factors which are known to those skilled in the art of cell culture.
For example, humoral factors could be mixed in a slow-release form with the cell-alginate suspension prior to formation of implant or transplantation. Alternatively, the hydrogel could be modified to bind humoral factors or signal recognition sequences prior to combination with isolated cell suspension.
Methods of Implantation.
The techniques described herein can be used for delivery of many different cell types to achieve different tissue structures. In the preferred embodiment, the cells are mixed with the hydrogel solution and injected directly into a site where it is desired to implant the cells, prior to hardening of the hydrogel. However, the matrix may also be molded and implanted in one or more different areas of the body to suit a particular application. This application is particlularly relevant where a specific structural design is desired or where the area into which the cells are to be implanted lacks specific structure or support to facilitate growth and proliferation of the cells.
The site, or sites, where cells are to be implanted is determined based on individual need, as is the requisite number of cells. For cells having organ function, for example, hepatocytes or islet cells, the mixture can be injected into the mesentery, subcutaneous tissue, retroperitoneum, properitoneal space, and intramuscular space. For formation of cartilage, the cells are injected into the site where cartilage formation is desired. One could also apply an external mold to shape the injected solution. Additionally, by controlling the rate of polymerization, it is possible to mold the cell-hydrogel injected implant like one would mold clay.
Alternatively, the mixture can be injected into a mold, the hydrogel allowed to harden, then the material implanted.
Specific Applications.
This technology can be used for a variety of purposes. For example, custom-molded cell implants can be used to reconstruct three dimensional tissue defects, e.g., molds of human ears could be created and a chondrocyte-hydrogel replica could be fashioned and implanted to reconstruct a missing ear. Cells can also be transplanted in the form of a thee-dimensional structure which could be delivered via injection.
The present invention will be further understood by reference to the following non-limiting examples.
EXAMPLE 1
Preparation of a Calcium-Alginate-chondrocyte Mixture and Injection into Mice to Form Cartilaginous Structures.
A calcium alginate mixture was obtained by combining calcium sulfate, a poorly soluble calcium salt, with a 1% sodium alginate dissolved in a 0.1 M potassium phosphate buffer solution (pH 7.4). The mixture remained in a liquid state at 4° C. for 30-45 min. Chondrocytes isolated from the articular surface of calf forelimbs were added to the mixture to generate a final cellular density of 1×10 7 /ml (representing approximately 10% of the cellular density of human juvenile articular cartilage).
The calcium alginate-chondrocyte mixture was injected through a 22 gauge needle in 100 μl aliquots under the pannus cuniculus on the dorsum of nude mice.
The nude mice were examined 24 hours postoperatively, and all injection sites were firm to palpation without apparent diffusion of the mixture. Specimens were harvested after 12 weeks of in vivo incubation. On gross examination, the calcium alginate-chondrocyte specimens exhibited a pearly opalescence and were firm to palpation. The specimens weighed 0.11±0.01 gms (initial weight 0.10 gms). The specimens were easily dissected free of surrounding tissue and exhibited minimal inflammatory reaction. Histologically, the specimens were stained with hematoxylin and eosin and demonstrated lacunae within a basophilic ground glass substance.
Control specimens of calcium alginate without chondrocytes had a doughy consistency 12 weeks after injection and had no histologic evidence of cartilage formation.
This study demonstrates that an injectable calcium alginate matrix can provide a three dimensional scaffold for the successful transplantation and engraftment of chondrocytes. Chondrocytes transplanted in this manner form a volume of cartilage after 12 weeks of in vivo incubation similar to that initially injected.
EXAMPLE 2
Effect of Cell Density on Cartilage Formation.
Varying numbers of chondrocytes isolated from the articular surface of calf forelimbs were mixed with a 1.5% sodium alginate solution to generate final cell densities of 0.0, 0.5, 1.0, and 5.0×10 6 chondrocytes/ml (approximately 0.0, 0.5, 1.0, and 5.0% of the cellular density of human juvenile articular cartilage). An aliquot of the chondrocyte-alginate solution was transferred to a circular mold 9 mm in diameter and allowed to polymerize at room temperature by the diffusion of a calcium chloride solution through a semi-permeable membrane at the base of the mold. The gels formed discs measuring 2 mm in height and 9 mm in diameter.
Discs of a fixed cellular density of 5×10 6 cells/ml were also formed in which the concentration of the sodium alginate and the molarity of the calcium chloride solutions were varied.
All discs were placed into dorsal subcutaneous pockets in nude mice. Samples were harvested at 8 and 12 weeks and examined for gross and histological evidence of cartilage formation.
Examinations of 8 and 12 week specimens revealed that a minimum cell density of 5×10 6 chondrocytes/ml was required for cartilage production which was observed only 12 weeks after implantation on gross examination, the specimens were discoid in shape and weighed 0.13±0.01 gms (initial weight 0.125 gms). The specimens were easily dissected free of surrounding tissue and exhibited minimal inflammatory reaction. Histologically, the specimens were stained with hematoxylin and eosin and demonstrated lacunae within a basophilic ground glass substance.
Cartilage formation was independent of calcium chloride concentration used in gel polymerization. Cartilage was observed in specimens with alginate concentrations varying from 0.5% to 4.0%; however, the lowest alginate concentration tested (0.5%) showed only microscopic evidence of cartilage.
Cartilage can be grown in a subcutaneous pocket to a pre-determined disc shape using calcium alginate gel as a support matrix in 12 weeks. Cartilage formation is not inhibited by either polymerization with high calcium concentrations or the presence of high alginate concentrations but does require a minimum cellular density of 5×10 6 cells/ml.
The ability to create a calcium alginate-chondrocyte gel in a given shape demonstrates that it is possible to use this technique to custom design and grow cartilaginous scaffolds for craniofacial reconstruction. Such scaffolds have the potential to replace many of the prosthetic devices currently in use.
EXAMPLE 3
Preparation of Implantable Premolded Cell-polymer Mixtures.
250 μl aliquots of an isolated chondrocyte suspension was mixed with 750 μls of a 2% (w/v) sodium alginate solution (0.1 M K 2 HPO 4 , 0.135 M NaCl, pH 7.4). A 125 μl aliquot was placed into 9 mm diameter cell culture inserts with 0.45 μm pore size semipermeable membranes. The cell-alginate mixture was placed into contact with a 30 mM CaCl 2 bath and allowed to polymerize for 90 minutes at 37° C. After 90 minutes, the cell-alginate gel constructs were removed from the mold and had a diameter of 9 mm and a height of 2 mm. The discs were placed into the wells of 24-well tissue culture plates and incubated at 37° C. in the presence of 5% CO 2 with 0.5 ml of a solution containing Hamm's F-12 culture media (Gibco, Grand Island, N.Y.) and 10% fetal calf serum (Gibco, Grand Island, N.Y.) with L-glutamine (292 μg/ml), penicillin (100 U/ml), streptomycin (100 μg/ml) and ascorbic acid (5 μg/ml) for 48 hrs.
Using this method, bovine chondrocyte-alginate discs were prepared, then implanted in dorsal subcutaneous pockets in athymic mice using standard sterile technique. After one, two, and three months, athymic mice were sacrificed, and the gel/chondrocyte constructs removed, weighed and placed in appropriate fixative. The cell-polymer complexes were studied by histochemical analysis.
Cartilage formation was observed histologically after three months of in vivo incubation at an initial chondrocyte density of 5×10 6 cell/ml.
The above protocol was modified by using a range of CaCl 2 concentration and a range of sodium alginate concentrations. Cartilage formation was observed using 15, 20, 30, and 100 mM CaCl 2 baths and 0.5, 1.0, 1.5, 2.0, and 4.0% sodium alginate solutions.
By changing the mold within which the cell-alginate construct is created, the shape of the implant can be customized. Additionally, the mold need not be semipermeable as calcium ion can be directly mixed with the cell-alginate solution prior to being placed within a mold. The key feature is that the construct can be fashioned into a given shape prior to implantation.
EXAMPLE 4
Preparation of Injectable Osteoblasts-hydrogel Mixtures.
Using the methodology described above, bovine osteoblasts have been substituted for chondrocytes and injected into animals using a hydrogel matrix.
Histology after 12 weeks of in vivo incubation showed the presence of early bone formation.
EXAMPLE 5
Use of the hydrogel matrix to form an immunoprotective matrix around the implanted cells.
By fashioning a cell-alginate construct as described above, one can use the hydrogel matrix to sterically isolate the encapsulated cells from the host immune system, and thereby allow allogenic cell transplants to form new tissues or organs without immunosuppression.
Bovine chondrocytes in an alginate suspension were transplanted into normal immune-competent mice. Histology after six weeks of in vivo incubation shows the presence of cartilage formation. Gross examination of the specimens does not demonstrate features of cartilage. Literature states that similar chondrocyte xenografts without alginate do not form cartilage.
Modifications and variations of the compositions and methods of the present invention will be obvious to those skilled in the art from the foregoing detailed description. Such modifications and variations are intended to come within the scope of the following claims. | Slowly polymerizing polysaccharide hydrogels have been demonstrated to be useful as a means of delivering large numbers of isolated cells via injection. The gels promote engraftment and provide three dimensional templates for new cell growth. The resulting tissue is similar in composition and histology to naturally occurring tissue. This method can be used for a variety of reconstructive procedures, including custom molding of cell implants to reconstruct three dimensional tissue defects, as well as implantation of tissues generally. | 2 |
This is a continuation of U.S. patent application Ser. No. 07/702,758 filed May 20, 1991, now abandoned.
BACKGROUND
The prevailing methods for parameter adjustment of monolithic filters by thin-film deposition are based on deposition on both sides of the filter wafer. The present application addresses the parameter adjustment based on deposition on only one side of the filter. Prior art information on this type of approach includes the E. C. Thomson U.S. Pat. No. 4,343,827, which discloses a method for fine-tuning a monolithic crystal filter having a solid electrode on one side of the crystal wafer and a pair of split electrodes on the opposite side.
The method has several disadvantages:
1) It does not provide for bandwidth adjustment. While normally it is desirable to adjust both the center frequency and bandwidth of a filter, the referenced method can only adjust the center frequency.
2) It requires deposition through at least two different-size mask apertures onto three fixed locations of the electrode, resulting in relatively complex deposition mechanisms.
3) It requires close-tolerance alignment between electrode and apertures. This can become critical in high-frequency filters, where the electrode areas become very small and the tolerance requirements very exacting.
4) It requires adherence to fixed areas of deposition. This restricts the freedom in optimizing the adjustment process.
Items 2) and 3) will be explained in more detail in the "Description of the Invention". Items 1) and 4) are explained as follows:
The parameter adjustment process, generally refers to the adjustment of the motional inductances L1, L2, and L' of the filter's electrical equivalent circuit, which is shown in FIG. 1. The circuit represents two coupled resonators 1 and 2 and includes an input terminal 1, an output terminal 2, and a common-ground terminal 3. The inductances can be determined by various different measurement approaches, each of them comprising a set of 3 electrical measurements. The F. L. Sauerland U.S. Pat. No. 4,725,971 discloses an adjustment based on the measurement of 3 frequencies, which are related to the equivalent-circuit parameters as follows: ##EQU1## F1 and F2 are the frequencies of resonators 1 and 2, respectively. In the Thomson patent, they are called the open circuit resonance frequencies. For the following, we will assume that we are dealing with symmetric or approximately symmetric filters, which are characterized by
L1≈L2≈L; C1≈C2≈C; CO1≈CO2≈CO(3)
In this case, a "symmetric frequency" is defined as ##EQU2## a "center" or "midband" frequency is defined as
Fc=F1=F2,
and a "bandwidth" is defined as
Bandwidth=Fa-Fs, (5)
where Fa is called the "antisymmetric" frequency and defined as ##EQU3## Fa is dependent on and determined by the choice of F1, F2, and Fs. The frequencies F1, F2, Fa, and Fs are in this application also called "characteristic" frequencies.
In a symmetric filter, the adjustment normally aims at equalizing F1 and F2 to the filter's target center frequency and (Fa-Fs) to the filter's target bandwidth. For this, the inductances are increased by mass deposition on the filter electrodes.
FIG. 2 shows a cross section of a monolithic crystal filter MCF with two coupled resonators 1 and 2, comprising a pair of electrodes 5 and 7 and an inter-electrode gap on one side of the wafer, and a common-ground electrode 9 on the other side. This is the schematic that will be used in the subsequent text, although the common-ground electrode may be implemented in different ways, such as shown in FIGS. 3 and 4. Electrodes 5 and 7 and the electrode areas opposite to and congruent with electrodes 5 and 7 will also be called "resonator electrodes", and the complete electrode configuration will also be called "electrode pattern".
In the conventional approach, the inductance L1 is increased by plating substantially the full area of one or both electrodes covering resonator 1. According to equation (1), this decreases the frequency F1 of resonator 1. Further, L2 is increased by plating substantially the full area of one or both electrodes covering resonator 2. According to equation (2), this decreases the frequency F2 of resonator 2. L' can be increased by plating the area of the inter-resonator gap on either side of the wafer. According to equations (1), (2), and (4), this will decrease F1, F2, and Fs, and it will decrease Fs more than F1 and F2, while it will not affect Fa. As a result, the bandwidth will be increased according to equation (5).
Consider now the adjustment method according to the Thomson patent, "which comprises the steps of a) plating additional electrode material on a selected portion of the solid electrode to balance open circuit resonant frequencies of the filter, and b) plating additional electrode material on substantially the entire solid electrode to adjust the filter to a desired midband frequency."
There is no claim nor provision for bandwidth adjustment in this method, nor is there the possibility for a bandwidth adjustment independent of the resonator-frequency adjustment: in step b) the frequencies F1, F2, Fa, and Fs are lowered simultaneously according to equations (1) to (3), but they cannot be changed independently from each other. This means that in step b) the bandwidth change will be small, and either the resonator frequencies or the bandwidth--but not both--can be adjusted to target values.
As is well-known to people skilled in the art, the lack of bandwidth adjustment is a disadvantage in the adjustment of monolithic filters. Accordingly, one purpose of this invention is to eliminate this disadvantage and to provide a method for adjusting both center frequency and bandwidth of a monolithic filter by deposition on only one side of the filter blank.
A further discussion will explain the disadvantage mentioned in item 4) above. As equations (1), (2), and (4) show, there are coupling effects that link the change of one characteristic frequency to changes in other characteristic frequencies. Since in practice, the placement of the deposition cannot be controlled exactly, the equations cannot exactly express these coupling effects. However, the coupling effects can be measured and expressed in terms of a "coupling matrix". A sample matrix might be ##EQU4##
This matrix describes the effect of changes in F1, F2, and Fs on Fa, Fs, and the difference (F1-FS), which is to be adjusted to zero in a symmetric filter. Practical values for the coupling coefficient might be ##EQU5##
This matrix gives vital information for the adjustment process for a given set of circumstances. For instance, coefficient C23 is relatively small. This means that a change in Fs causes only a small changes in Fa. According to equation 6 this implies that increasing L' (in order to change Fs) produces only a small change in L1 and/or L2. This in turn implies that in the case described by matrix (8), L' is being increased by deposition of a narrow strip in the vicinity of the inter-resonator gap, i.e. without simultaneously increasing L1 and/or L2. In the Thomson method, the C23 value would be close to 1, since the deposition covers the whole solid electrode, thereby decreasing L1 and L2 as well as L'. According to equations (1) to (6), this produces a major change in F1 and F2 and only a minor change in the bandwidth.
There are conventional adjustment methods, based on deposition on both sides of the filter, that provide for adjustment of both center frequency and bandwidth. They are normally based on deposition onto 3 fixed areas of the filter electrodes, and they are normally done in steps, alternating the plating between the 3 fixed electrode areas. A typical approach might first alternate between plating resonators 1 and 2 to equalize F1 and F2 and adjust them to an intermediate target, then adjust Fs, then if necessary repeat the steps until F1, F2, and Fs reach their final targets. During these steps, the coupling coefficients are essentially fixed within relatively narrow boundaries because the deposition areas are fixed. This is a limitation of the conventional approach. If the deposition areas were variable, the coupling coefficients could be changed and optimized during the process, and the number of plating steps and the total plating could be reduced. This is further explained in the description of the invention.
While there are various other conventional methods for adjusting monolithic filters, they all appear to share at least some or all of the described disadvantages. Accordingly, the primary purpose of this invention is to provide new and improved methods and apparatus for adjusting the electrical parameters of monolithic filters that are free of the described disadvantages.
SUMMARY OF THE INVENTION
In accordance with one method aspect of the invention, a method for adjusting the center frequency and bandwidth of a monolithic crystal filter having an electrode pattern that includes resonator electrodes and inter-resonator gap and constitutes two coupled resonators, based on thin-film plating on the electrode pattern on one side of the filter, and comprising the steps of
a) plating a thin film on substantially the full area of the resonator electrodes on said one side of the electrode pattern, for the purpose of adjusting the two resonator frequencies and the filter's center frequency, and
b) plating a thin film of a width approximately equal to the inter-resonator gap in the center of said one side of the electrode pattern, for the purpose of adjusting the filter's bandwidth.
In accordance with another method aspect of the invention, a method for adjusting the electrical parameters of a monolithic crystal filter to target values, said filter having an electrode pattern that includes resonator electrodes and inter-resonator gap and constitutes two coupled resonators, based on thin-film plating on the electrode pattern on one side of said filter, and comprising the steps of
a) plating a thin film onto a first area on said one side of said electrode pattern,
b) measuring the effect of said plating on said electrical parameters,
c) in response to said parameter measurements, changing said area of plating to another area of said one side of said electrode pattern, suitable for adjusting said parameters toward target values,
d) plating a thin film onto said other area of said electrode pattern,
e) repeating steps b, c, and d for further platings until the parameter targets are reached.
In accordance with an apparatus aspect of the invention, apparatus for adjusting center frequency and bandwidth of a monolithic crystal filter having an electrode pattern that includes resonator electrodes and inter-resonator gap and constitutes two coupled resonators, based on thin-film plating on the electrode pattern on one side of the filter, comprising
a) a mask with a first and a second aperture, said first aperture having substantially the dimensions of one of said resonator electrodes, and said second aperture having substantially the dimensions of said inter-resonator gap, said mask facing said one side of the electrode pattern and having relative mobility with respect to said filter such as to allow the alignment of said first aperture opposite one and the other of said resonator electrodes, as well as the alignment of said second aperture opposite said inter-resonator gap, said respective alignments being called the plating positions,
b) an evaporation source for plating a thin film through said apertures when they are aligned in their respective plating positions,
c) means for electrically contacting the terminals and for measuring the resonator frequencies and bandwidth of said filter,
d) means for evaluating said measurements and, in response to said evaluation, determining and causing the movements of said first and second apertures into respective plating positions for adjusting the center frequency and bandwidth of said filter.
In accordance with another apparatus aspect of the invention, apparatus for adjusting the electrical parameters of a monolithic crystal filter to target values, said filter having an electrode pattern that includes resonator electrodes and inter-resonator gap and constitutes two coupled resonators, based on thin-film plating on the electrode pattern on one side of said filter, comprising
a) a mask with a single aperture, said aperture having a width preferably smaller than the width of the resonator electrodes and larger than the width of the inter-resonator gap,
b) a mounting means for the filter and mask that affords mobility of said filter and mask relative to each other such as to allow alignment of said aperture opposite any part of said one side of the electrode pattern, said different alignments being called plating positions,
c) an evaporation source for plating a thin film through said aperture when it is in a plating position,
d) means for electrically contacting the terminals of said filter and for making measurements of the electrical parameters of said filter,
e) a plating control means for
e-1) evaluating said measurements when said aperture is in a plating position, and for determining a new plating position suitable for changing said electrical parameters to new values that converge toward target values,
e-2) moving said aperture to said new plating position for controlled plating to said new parameter values,
e-3) repeating steps e-1) and e-2) until the target values are reached.
The invention offers the following advantages over conventional approaches:
a) simpler construction, in that it requires a mask with only a single aperture.
b) substantially reduced tolerance requirements for the initial mask alignment, in that the mask aperture may be substantially smaller than the filter electrode and can be moved in relation to it,
c) substantially increased flexibility in the adjustment process, in that the deposition is not restricted within fixed boundaries but can be directed to any area of the filter electrode.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference is made to the following description, taken in connection with the accompanying drawings.
FIG. 1 shows an electrical equivalent circuit for a monolithic crystal filter comprising two coupled resonators.
FIG. 2 shows a cross section of a monolithic filter wafer with an electrode pattern comprising a pair of electrodes and an inter-electrode gap on one side and a solid common-ground electrode on the opposite side.
FIG. 3 shows the cross section of a monolithic filter wafer with an electrode pattern comprising a pair of electrodes and an inter-resonator gap on each side. One pair of electrodes on one side has been electrically interconnected to form a common-ground electrode.
FIG. 4 shows the cross section of a monolithic filter wafer with an electrode pattern comprising a pair of electrodes and an inter-resonator gap on each side. One electrode on one side has been electrically interconnected with the diagonally opposite electrode to form a common-ground electrode.
FIG. 5 shows a simplified schematic, comprising a monolithic filter and a mask with two apertures, for one approach according to the invention.
FIG. 6 shows a simplified schematic, comprising a monolithic filter and a mask with a single aperture, for another approach according to the invention.
FIG. 7 shows an electrode pattern of a monolithic filter and a superimposed pattern of a conventional mask aperture.
FIG. 8 shows an electrode pattern of a monolithic filter and a superimposed pattern of a mask aperture according to the invention.
FIGS. 9 and 10 show electrode patterns of a monolithic filters with a superimposed pattern of a mask aperture according to the invention shown in two different positions.
FIG. 11 shows an approach according to the invention, comprising a monolithic filter, a mask, and a scale x for the relative movement of mask versus filter.
FIG. 12 shows curves for three coupling coefficients as a function of x.
FIG. 13 shows another electrode pattern of a monolithic filter with a superimposed pattern of a mask aperture according to the invention.
FIG. 14 shows the top view of another simplified schematic for an approach according to the invention for adjusting the electrical parameters of a monolithic filter by thin-film deposition.
FIG. 15 shows a side view of the arrangement per FIG. 9, additionally including means for contacting the filter terminals and for measuring the filter parameters and controlling the plating.
DESCRIPTION OF THE INVENTION
FIG. 5 shows one adjustment scheme according to the present invention. It includes a monolithic filter MCF with an electrode pattern comprising two electrodes 5 and 7 on one side and a common ground electrode 9 on the other side, faced by a mask 11 with two apertures 10 and 12. Aperture 10 has a width approximately equal to the width of the gap between electrodes 5 and 7, while aperture 12 has a width approximately equal to the width of electrodes 5 and 7. Filter MCF and mask 11 can be moved relatively to each other in the direction of arrows 16. An evaporation source 14 is positioned such that it can deposit a thin film within the width W, which is approximately equal to the width of the common ground electrode 9.
The arrangement can be used for parameter adjustment as follows:
First, the resonator frequencies F1 and F2 are lowered and equalized. This is done by adjusting the relative position of filter and mask such as to alternately direct deposition through aperture 12 onto the areas on electrode 9 that are opposite to the two electrodes 5 and 7.
Second, the bandwidth is adjusted by lowering the symmetric frequency Fs. This is accomplished by adjusting the relative position of filter and mask such as to direct deposition through aperture 10 onto the area on electrode 9 that is opposite to the gap between electrodes 5 and 7. The first and second steps can be repeated until the targets for the resonator frequencies and bandwidth are reached.
The advantage of this adjustment scheme over the prior-art scheme according to Thomson is that it provides for adjustment of both center frequency and bandwidth of the filter.
FIG. 6 shows another adjustment scheme according to the present invention. It comprises a monolithic filter MCF with an electrode pattern comprising two electrodes 5 and 7 on one side and a common ground electrode 9 on the other side, faced by a mask 15 with a single aperture 13. Aperture 13 has a width preferably not larger than the width of electrodes 5 and 7 and not smaller than the width of the gap between electrodes 5 and 7. An evaporation source 18 is positioned such that it can deposit a thin film through aperture 13. Mask and filter can be moved relative to each other in the direction of the arrows 17, such that deposition can be directed during the adjustment process to any area of electrode 9.
The advantages of this approach over prior-art methods were mentioned in the "Summary" and can be further explained as follows:
a) the mechanical design is simplified, in that the need for multiple apertures or multiple deposition mechanisms has been eliminated.
b) the tolerance requirements, for the initial mask alignment have been reduced significantly. This can be seen from FIGS. 7 and 8.
FIG. 7 shows a conventional mask aperture 11, such as according to the cited Thomson patent, superimposed on the solid filter electrode 9. Normally the deposition is to cover as much of the electrode area as possible, but none of the surrounding areas. To keep (he deposition from spilling beyond the electrode boundaries, the mask must be initially aligned laterally within a tolerance of +/-D/2, where the value for D is given in FIG. 7.
FIG. 8 shows a mask aperture 13 according to the invention, superimposed on the solid filter electrode 9. The aperture is narrower than the width of electrode 9. Before starting the deposition, the aperture must be aligned anywhere within the area of the electrode. For this, the tolerance is +/-d/2, where the value for d as given in FIG. 8 is substantially larger than the value for D per FIG. 9.
c) the flexibility of the adjustment process is increased substantially, in that the deposition is not restricted by fixed mask boundaries but can be directed to any area of the electrode.
This can be explained by reviewing the adjustment process, with reference to FIGS. 9 and 10, which show two further positions of the aperture 13 superimposed on the common ground filter electrode 9, as well as the outlines of the two resonator electrodes 5 and 7 on the opposite filter side.
The arrangement can be used for parameter adjustment as follows:
First, the resonator frequencies F1 and F2 are lowered and equalized. This is done by adjusting the relative position of filter and mask such as to alternately direct deposition through aperture 13 onto the areas on electrode 9 that are opposite to the two electrodes 5 and 7, such as shown in FIGS. 9 and 10.
Second, the bandwidth is adjusted by lowering the symmetric frequency Fs. This is accomplished by adjusting the relative position of filter and mask such as to direct deposition through aperture 13 onto the area on electrode 9 that is opposite to the gap between electrodes 5 and 7.
The first and second steps can be repeated until the targets for the resonator frequencies and bandwidth are reached.
In this approach, the choice of the aperture width is important and is usually a compromise between two extremes:
If the aperture is narrow, such as on the order of the inter-resonator gap width, the coupling coefficient C23 will be small, allowing a bandwidth adjustment that has a negligible effect on the resonator frequencies F1 and F2. In other words, according to equations 5 and 6, the bandwidth can be adjusted by lowering the symmetric frequency Fs without simultaneously lowering the antisymmetric frequency Fa. However, the deposition for the adjustment of F1 and F2 covers a relatively small area opposite electrodes 5 and 7, which can produce undesired effects, such as spurious filter responses.
On the other hand, as the aperture is widened, the bandwidth adjustment will be accompanied by an increasing effect on lowering F1 and F2 until, when the aperture has the same width as electrode 9, it reaches the limitations of the prior-art method according to Thomson.
For the method according to FIG. 6, the coupling matrix can be expressed in terms of the aperture's position on the parameters (F1-F2), Fa, and Fs. This can be explained by reference to FIG. 11, which shows a monolithic filter MCF with two resonator electrodes 5 and 7 and a common-ground electrode 9. Aperture 13 of a mask 15 is positioned in the "center position", which for the present purpose is defined as the center of the gap between electrodes 5 and 7. A horizontal scale x is shown, with x=0 at the "center position". Further, the center lines for electrodes 5 and 7 are shown as being offset from the "center position" by x=-a and x=a, respectively. With, this, matrix (8) can be re-written in terms of the aperture's x-position as follows ##EQU6##
So far, the described adjustment sequence for the arrangement of FIG. 6 has been similar to the conventional approach in that the deposition has been implicitly restricted to 3 fixed areas of the electrode, and the coupling coefficients have been restricted accordingly. However, in the approach according to the invention, the deposition can be directed to any area of the electrode, and the coupling coefficients are continuously adjustable within their maximum and minimum limits.
If for example any one of the aperture positions in matrix (9) is changed, the coupling coefficients for that position will be changed. If for example the position x=-a in matrix (9) is changed to x=-a/2, the new matrix may look as follows: ##EQU7##
Compared to matrix (9), the values for coefficients C11, C12, and C13 are different in the new matrix (10). For example, C11 is smaller, because now the deposition is only partially covering the electrode area of resonator 1. Conversely, C13 is larger, because now the deposition is partially covering the area of the inter-electrode gap.
Matrix (10) can be written in a more general way in terms of three sets of coupling coefficients that are functions of x:
C<(F1-F2), x>C<Fa, x>C<Fs, x> (11)
By extending the reasoning used for C11 and C13 above to the coefficients (11), or by measuring the dependence of (F1-F2), Fa, and Fs on the aperture position x, one can determine and plot the values of the coupling coefficients (11) as a function of x. This is shown in a qualitative way in FIG. 12 over the width W of the common-ground electrode 9 of FIG. 11. The curve shapes for the coupling coefficients are strongly dependent on the relative width of aperture, resonator electrode, and inter-resonator gap.
FIG. 12 illustrates that if the aperture position is continuously adjustable, the coupling coefficients are continuously adjustable within minimum and maximum limits. This is an important feature. If, for example, during the adjustment process, both (F1-F2) and Fs are to be changed to specific intermediate target values, the aperture position x and thereby the coefficients C <(F1-F2),x> and C<Fs,x> can be chosen such that the two targets can be reached in a single deposition step. This is not possible in the conventional fixed-mask approach.
In an implementation of an adjustment system according to the invention, a step motor is used to provide the relative motion of mask versus filter. Electronic instrumentation, which can be of a conventional type, such as described in the Sauerland patent, is used to measure the characteristic frequencies. A computer is used to evaluate the coupling coefficients from these measurements, correlate them with the aperture position via the step motor position, and to memorize and if necessary update them. Various algorithms can then be used to choose the sequence and position for the aperture movement for optimum convergence of the adjustment process to the target values.
The adjustment does not have to begin with the aperture in any specific position. For high-frequency filters, the electrode pattern may be so small that an exact initial alignment is difficult to achieve. In the approach according to the invention, it is sufficient that the initial alignment falls anywhere within the confines of the electrode pattern. A first deposition in this position and a subsequent measurement of the coupling coefficients will provide information about the relative position of aperture versus electrode pattern. This information can then be used to guide the next deposition step.
The adjustment is not limited to a stepwise approach: with fast means for measuring and computing, the plating control can be done in real time, such that the aperture can be moved continuously rather than in steps.
Further flexibility is provided by the possibility of either increasing the bandwidth by depositing in the center per FIG. 8, or by decreasing it by depositing on the electrode edges opposite the center. The bandwidth decrease can be understood as follows: when plating on the outer electrode edges, L1 and L2 are increased, but L' is not. According to equations (4) and (6), the increase in L1 and L2 will lower Fa more than Fs. As a result, (Fa-Fs) will be decreased.
The approach is not limited to filters of the type depicted in FIG. 2 but can also be applied to other filter types, such as shown in FIGS. 3 and 4. For example, FIG. 13 shows an aperture 13 superimposed on two filter electrodes 5 and 7. In this case, the aperture can be moved anywhere within the confines of the two electrodes 5 and 7, and the coupling coefficients can be adjusted accordingly, although within a more limited range than for the configurations shown in FIGS. 8, 9, and 10.
In some cases it may be desirable to protect the deposition from spilling over the electrode borders. In these cases, an additional fixed mask may be used to cover the filter such that only the electrode areas can be exposed to deposition.
FIG. 14 shows the simplified top view of another scheme according to the invention, suitable for sequential adjustment of multiple filters. Three filters MCF are shown mounted on a "carrier" 33. Facing one filter is a mask 15 with an aperture 13. An evaporation source 31 is arranged such as to be able to evaporate through aperture 13 onto the solid filter electrode 9. Carrier 33 can be moved laterally as indicated by the arrows 35, such that all filters can be sequentially moved into position opposite mask 27 for adjustment. During the adjustment, carrier 33 can further be moved back and forth in the direction of the arrows 35 such as to direct the deposition to any desired area of the filter electrode.
FIG. 15 shows a side view of carrier 33 of FIG. 14 with 3 filters MCF, each of whose three contact pins 36, 37, 38 protrude through the carrier and can be accessed by contacts 39, 40, 41 for connection to circuit 43, which comprises means for parameter measurement and plating control. This circuit can be of a conventional type, such as described in the cited Sauerland patent.
In summary, two fundamental embodiments of the invention have been described, both based on thin-film deposition through a mask on the electrode pattern on one side of a monolithic filter, and both using relative mobility of the mask versus the filter. One embodiment comprises deposition through a single mask aperture onto any part of the electrode pattern. The other embodiment comprises deposition through two different mask apertures, with one aperture serving to direct the deposition to two areas offset from the center of the electrode pattern and essentially covering the areas of the two resonator electrodes, and the other aperture serving to direct the deposition to a narrow area in the center of the electrode pattern. From the description it will be obvious to those skilled in the art that various changes and modifications may be made--such as increasing the number of apertures beyond two--without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention. | Method and apparatus for adjusting the electrical parameters of monolithic crystal filters having an electrode pattern that includes resonator electrodes and inter-resonator gap and constitutes two coupled resonators, based on thin-film deposition on the electrode pattern of one side of the filter through a single-aperture mask, with mask and filter movable relatively to each other during the adjustment process, such as to be able to guide said deposition in response to measurements of said electrical parameters to any area of said electrode pattern for the purpose of adjusting said parameters to their target values. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The simultaneous staking of a plurality of wires into wire-in-slot blades on contact members positioned in two rows, one row being positioned over the other.
2. Description of the Prior Art
A U.S. Pat. No. 3,775,552 issued on Nov. 27, 1973 disclosing a ribbon coaxial cable of the type having a plurality of signal wires, each protected by its own shielding, and each being paralleled by a drain wire in contact with the shielding.
Subsequent thereto a connector was invented and disclosed in U.S. Pat. No. 3,864,011. This connector, developed for ribbon coaxial cable consisted of contact members having wire-in-slot blades and a housing having a plurality of passages arranged in two rows, one row over the other. Further, the passages in one row were designed to accept the contact members so that the blades or more particularly the openings to the wire-receiving slots faced in one direction and the passages in the other row were designed so that the openings to the slots in those contact members faced in the opposite direction.
Thereafter a tool was invented wherein the connector was inserted and the assembly therein would stake all the signal wires simultaneously into the wire-receiving slots on the contact members in one row. The connector would be withdrawn from the tool, turned over and reinserted. Thereafter all the drain wires would be staked simultaneously into the wire-receiving slots on the contact members in the second row. An application, Ser. No. 615,273, disclosing this tool was filed in the United States Patent and Trademark Office on Sept. 22, 1975 is now U.S. Pat. No. 4,017,954.
Subsequently a connector was invented which consisted of two sets of contact members, all having wire-in-slot blades but with one set having such blades offset to the right and the second set having such blades offset to the left. The housing for these contact members contains a plurality of passages arranged in two rows, one row over the other. The back face of the passages each have a rearwardly extending platform on which the blades rested: the platforms on one row being offset to the right and the platforms on the second row being offset to the left. This arrangement permitted the passages to be in direct overlying alignment while permitting direct and simultaneous access to all the wire-in-slot blades in both rows. This connector is disclosed in an application, Ser. No. 683,575, filed concurrently herewith and incorporated herein by reference.
The tool of the present invention was invented to simultaneously stake or terminate all signal and drain wires into the wire-in-slot blades in the above-described connector. With one stroke of the tool the signal wires are staked into the contact members occupying one row of passages and the drain wires are staked into the contact members occupying the other row.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a tool having a wire support assembly mounted on a lower, stationary base and a connector support assembly mounted on the upper, movable member. The connector support assembly, retains the connector during the staking operation. The wire support assembly consists of a series of functionally-related posts and slots. The connector, containing a plurality of contact members is placed in the connector support assembly so that the openings to the wire-in-slot blades are facing downwardly. Several sets of posts of the assembly restrain the blades in the upper rows of contact members against lateral movement. A wire cutoff plate is included as part of the moving assembly.
The several wires comprising a ribbon cable are placed in the wire support assembly, the comb dressing the wires so that they lay across the series of posts and slots in a predetermined order. As the connector support assembly descends, the wire cutoff plate shears and trims the ends of the wires protruding beyond the wire support assembly. Thereafter the wire-in-slot blades are pushed onto the wires, the posts and bases of the slots in the wire support assembly providing the wire support means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the tool containing the preferred embodiments of the present invention;
FIG. 2, taken along lines 2--2 of FIG. 1, is a side elevational view looking into the area where the cutting and staking operations occur;
FIG. 3 is an exploded, perspective view of the wire support assembly;
FIG. 4a, taken along lines 4--4 of FIG. 2, shows the floating comb optionally provided on the wire support assembly of FIG. 3;
FIGS. 4b and 4c are views taken along lines 4b--4b and 4c--4c of FIG. 4a;
FIG. 5 is an exploded, perspective view of the connector support assembly;
FIG. 6a is a perspective view of the back of the connector and the ribbon coaxial cable;
FIG. 6b is a view of a contact member housed in the connector of FIG. 6a;
FIGS. 7 and 8 are side elevational, cross-sectional views illustrating the staking, terminating and wire-cutting operations of the tool of FIG. 1; and
FIG. 9 is a side elevational, cross-sectional view of the connector of FIG. 6 subsequent to the staking operations depicted in FIGS. 7 and 8.
______________________________________LISTING OF THE ELEMENTS10 - Tool12 - C-shaped frame14 - Base16 - Upper support member18 - Work space20 - Lower assembly22 - Ram23 - Upper assembly24 - Handle (ram)20 - Lower Assembly26 - Base plate28 - Cable support block30 - Comb and stake assembly retaining unit32 - Guide block36 - Block38 - Comb and stake assembly40 - Side panels42 - Vertical posts46 - Dowel pins105 - Machine screws38 - Wire Support Assembly50 - Comb plate51 - Posts52 - Short slots54 - Long slots58 - First wire support plate60 - Posts62 - Slots64 - First blade support plate66 - Posts68 - Slots72 - Second wire support plate74 - Posts76 - Slots78 - Back side80 - Leg81 - Cross-tie portion84 - Upwardly facing shoulder86 - Second blade support plate220 - Posts222 - Slots88 - Third wire support plate90 - Posts92 - Slots94 - Floating comb96 - Arcuate notches98 - Posts100 - Slots102 - Leaf spring104 - Bight106 - Free ends23 - Upper Assembly48 - Wire cutoff plate110 - Connector support assembly112 - Upper mounting block154 - Shouldered pin160 - Shoulder162 - Four studs208 - Forwardly facing shoulder114 - Upper side panels116 - Upper block support plate110 - Connector Support Assembly122 - Cover plate124 - First support plate126 - Posts128 - Slots132 - First platform support plate134 - Second support plate136 - Posts138 - Slots140 - Second platform support plate142 - Locator plate144 - Beveled teeth146 - Slots147 - Rear bevel on teeth48 - Wire Cutoff Plate148 - Forward shelf150 - Forwardly facing shoulder152 - Forward bottom cutting edge156 - Opening (to receive pin 154)158 - Counterbore (to receive shoulder 160)170 - Connector172 - Housing174 - Passages175 - Back end176 - PlatformU - UpperL - Lower210 - Space between platforms206 - Front end178 - Contact membersU - UpperL - Lower180 - Terminal section182 - First wire-in-slot blades184 - Second wire-in-slot blades186 - Second side on U-shaped portion188 - Wide slot190 - Bight on the U-shaped portion192 - Wire-receiving slots194 - Contact arms196 - Intermediate section (between 180-194)198 - Ribbon coaxial cable200 - Signal wires202 - Drain wires204 - Insulating jacket205 - Cable end______________________________________
DESCRIPTION OF THE PREFERRED EMBODIMENT
The hand operated tool 10 shown in perspective in FIG. 1 is but one type of mechanism which can be used in practicing the present invention. The tool has a C-shaped frame 12 with a base 14, an overhead support member 16 and a work space 18 inbetween. The base 14 provides support for the lower assembly 20 of the present invention. The overhead support member 16 accommodates a movable ram 22, upper assembly 23, ram-actuating handle 24 and mechanism (not shown) connecting the two. These elements of tool 10, i.e., the frame, base, ram, handle and so forth (excluding assemblies 20 and 23) are well known in the industry and do not per se form a part of this invention.
The lower assembly 20 is shown in FIGS. 1-3, 5 and 7, 8. With reference specifically to FIG. 2 and generally to the others, the assembly includes a base plate 26 on which are positioned three units; the cable support block 28 to the left, a wire support assembly retaining unit 30 in the middle and the guide block 32 to the right.
The cable support block 28, in addition to providing a rest for the cable, aids in securing the wire support assembly in the front face of unit 30.
The retaining unit 30 includes a block 36, the wire support assembly 38 and a pair of side panels 40, one on either side of the block. The wire support assembly 38 is also shown in an exploded view in FIG. 3.
The two side panels 40 have a vertical post 42 which provides stop means for the tool's moving members.
Guide block 32 holds two vertical dowel pins 46, one on either side. The wire cutoff plate 48 slides up and down on these pins but only under an applied force.
Referring to FIG. 3, the wire support assembly consists of a number of plates beginning with the comb plate 50 which is on the left of the drawing.
Comb plate 50 has on its upper edge a plurality of beveled posts 51 defining short slots 52 alternating with long slots 54.
The second plate from the left is the first wire support plate 58. Its upper edge consists of a plurality of flat-topped posts 60 and a plurality of slots 62.
The third plate from the left is the first blade support plate 64. The upper edge of the plate consists of a plurality of posts 66 and slots 68.
The fourth plate from the left is the second wire support plate 72. Its upper edge consists of a plurality of T-shaped posts 74 and slots 76, the bases of which are also T-shaped.
Plate 72 is preferably milled out from a thick sheet of metal to provide the legs 80 of the T-shaped posts and slots bases. The cross-tie portions are designated by reference numeral 81. The base of the plate, on its back surface 78, has a thick section to provide an upwardly facing shoulder 84. With reference to FIGS. 4a and 4b, it can be seen that legs 80 need not extend much below the base of slots 76.
The fifth plate is the second blade support plate 86 and it too has a plurality of posts 220 and slots 222 on its upper edge.
The last plate shown in FIG. 3 is the third wire support plate 88. Its upper edge consists of a plurality of posts 90 and bottom slots 92. The third wire support plate has a second function of providing a shearing edge to cooperate with the wire cutoff blade 48. Slots 92 are V-shaped to provide better cutting by the blade 48.
The six plates shown in FIG. 3 are held together by three machine screws (not shown) passing through the openings in the lower half of each plate and received in threaded apertures (not shown) in block 36.
As shown in FIG. 2, 7 and 8, the wire support assembly may also include a second comb adapted to keep the wires aligned during the staking operation. FIGS. 4a, 4b and 4c illustrate this second comb which is hereinafter designated as floating comb plate 94. The comb itself consists of a half plate having three arcuate notches 96 along its bottom edge. Its upper edge consists of a plurality of posts 98 which define a plurality of slots 100. The comb is positioned against the back surface 78 of plate 72 with the legs 80 of the T-shaped posts and slot bases located in slots 100. FIGS. 4b and 4c illustrate this positioning quite clearly.
The floating comb 94 is biased upwardly by a simple V-shaped leaf spring 102. The bight 104 of the spring is positioned between the center screw 105 and shoulder 84 on plate 72. The two free ends 106 of the spring abut the bottom surface of plate 94. During the staking operation the floating comb is pushed down out of the way. The arcuate notches provide clearance of the attachment machine screws.
It is to be noted here that the wire support assembly can function with or without floating comb 94.
With reference to FIG. 2, upper assembly 23 includes the wire cutoff plate 48, the connector support assembly 110, an upper mounting block 112, a pair of upper side panels 114, and an upper block support plate 116 positioned between block 112 and ram 22. The function of the side panels are to insure lateral alignment of the assembly 110.
The connector support assembly 110 is shown in exploded fashion in FIG. 5. Its orientation in the drawing is the same as it is shown in FIGS. 1 and 2.
The first plate on the left is cover plate 122. Its function is to provide proper spacing of the following plates with respect to the underlying wire support assembly 38.
The second plate from the left is the first support plate 124. The lower edge consists of a plurality of depending posts 126 which define slots 128 therein between. The free ends of the posts are beveled on either side.
The third plate from the left is the first platform support plate 132. Its edges are straight.
The fourth plate from the left is the second support plate 134. Its lower edge is identical to that of plate 124 in that it consists of a plurality of posts 136 and slots 138.
The fifth plate from the left is the second platform support plate 140. Its edges are straight.
The sixth and last plate is locator plate 142. Its lower edge has a plurality of beveled teeth 144 and slots 146. In addition the back side of each tooth is beveled as shown in FIG. 7 and indicated by reference numeral 147.
With reference to FIG. 2, wire cutoff plate 48 has a forward shelf 148 and a forwardly facing shoulder 150. The forward bottom cutting edge 152 is inclined from one side to the other to provide a progressive cutting blade in conjunction with plate 88 of the wire support assembly 38.
Plate 48 is attached to block 112 by a shouldered pin 154 passing through an opening 156 which is centrally located between the openings (not shown) in the plate which receives the dowel pins 46. The base of opening 156 has a counterbore 158 on which the shoulder 160 on the pin bottoms. The plate slides freely on pin 154.
Four studs 162 (two of which are shown) on block 112 provide proper stand-off between that block and plate 48 during downward travel of the upper assembly 23.
The connector which is used in conjunction with tool 10 is shown in FIG. 6a and is designated by reference numeral 170. Connector 170 consists of a housing 172 of insulating material such as glass-filled nylon. Two rows of passages 174 extend through the housing from front to back end 175. The rows are arranged in overlying relations with the upper passages being in direct alignment with the lower passages. The letters "U" and "L", added to reference numeral 175, designate the upper and lower rows.
A platform 176 projects rearwardly from the top edge of each passage; however the platform adjacent the upper passages, hereinafter designated by the reference numeral 176-U are horizontally offset to the left relative to the platforms adjacent the lower passages, hereinafter designated by reference numeral 176-L.
With reference to FIG. 6b contact members 178 have on one end a terminal section 180 having first and second wire-receiving slotted blades 182 and 184 respectively. (See FIG. 9.) The second blade 184 is formed from one side of a U-shaped portion. The second side, positioned between blades 182 and 184 and designated by reference numeral 186, has a wide post receiving slot 188 therein and extending through bight 190, such width being compared to the smaller width slots 192 in blades 182 and 184 which receive the wires. Each wire-receiving slot 192 has a funnel shaped opening 193. The other end of the contact members 178 consist of a contact arm 194 (FIG. 9) suitable for electrical engagement with like contact arms in like connectors. An intermediate section 196 connects the contact arm to the terminal section.
The contact members, to the extent discussed, are identical. However the terminal sections 180 on the contact members which occupy the upper row of passages 174, hereinafter designated as contact members 178-U, are offset to the left relative to the intermediate section and the contact members occupying the lower row of passages, hereinafter designated as contact members 178-L, have their terminal section 180 offset to the right; all as viewed from the back as seen in FIG. 6a. The contact member in FIG. 6b is offset to the left as indicated by jog 197. The orientation permits the terminal sections to be aligned directly with the platforms 176 associated with the passages.
The ribbon coaxial cable 198 which is to be terminated to connector 170 is shown to the right in FIG. 6a. This cable consists of a plurality of signal wires 200 and a plurality of parallel drain wires 202. A dielectric sheath and foil sheath (neither are shown) surround each signal wire. An outer insulating jacket 204 provides a single covering for the signal and drain wires.
THE METHOD OF SIMULTANEOUS TERMINATION
Cable 198 is prepared for termination by removing jacket 204, the dielectric and foil so as to expose a length of signal and drain wires. Their are two options available with respect to such stripping and either is satisfactory. The stripping may be done at the end of the cable as shown in FIG. 6a or a section may be stripped at a short distance inwardly from end 205 as shown in FIG. 7. The latter method is preferred in that the insulation at the end of the cable maintains the wire alignment during storage and handling.
FIGS. 2 and 7 show that connector 170 is placed into the upper assembly 23 with the openings in the wire-in-slot blades facing downwardly toward the wire support assembly 38.
The front end 206 of the connector is slid into the space between block 112 and wire cutoff plate 48. Preferably the back end 175 is tilted downwardly until the front end 206 of the connector abuts a forwardly facing shoulder 208 on the underside of block 112. Then, as the back end of the connector is rotated or moved upwardly, the beveled portion 147 on teeth 144 enter into the spaces 210 (FIG. 6a) between platforms 176-U on the connector and in so doing align the connector. Further upward movment of the connector drives the first and second support plates 124 and 134 into position; i.e., the posts 126 and 136 rest against platforms 176-L as shown in FIG. 7 and the sides of the posts bear against the sides of blades 182 and 184 on contact members 178-U. Each blade is laterally supported between two adjacent posts. The beveled end on the posts facilitate the positioning. Further, the bottom edges of plates 132 and 140 are in abutting contact with platforms 176-U as well as the bases of slots 128 and 138 in plates 124 and 134 respectively.
The connector is held securely in the connector support assembly 110 by interference. As indicated in FIG. 7, the wire cutoff plate 48 is not in contact with connector housing 172 at this time.
Still with reference to FIG. 7, prepared cable 198 is placed into the wire support assembly 38 so that the signal wires 200 are lying through short slots 52 in comb 50 and on top of posts 60, 74 and 90 on plates 58, 72 and 88 respectively; the drain wires (not shown) are lying through long slots 54 in comb 50, and above slots 62, 76 and 92 in plates 58, 72 and 88 respectively. Note that the wires can be loaded into the assembly in the reverse order without material effect.
The next step is to move ram 22 and connector 170 downwardly. After traveling a short distance the upper assembly contacts wire cutoff blade 48 and it too is pushed downwardly toward the lower assembly 20. The aforementioned studs 162 on the underside of block 112 provides the proper spacing between that block and the forward shelf 148 on the plate 48 so that the connector housing 172 is now positioned between the two.
As the upper assembly approaches the lower assembly the blade or cutting edge 152 severs the end 205 of cable 198 extending back of plate 88 as shown in FIG. 8.
After the excess wire is cut off, the back end of connector 170 enters the wire support assembly 38, which projects up above block 36 and side panels 40.
As the lower contact members 178-L move down, blades 182 thereon pass directly in front of slots 62 on plate 58 and down into slots 68 on plate 64 so that the posts 66 bracket each blade. Blades 182 also pass directly in back of slots 76 on plate 72.
The second sides 186 and bights 190 move down into slots 76. Posts 74 bracket the sides.
The blades 184 pass directly in front of slots 76 and directly behind slots 92 in plate 88. The blades are moving down into slots 222 in plate 86 and down into slots 68 on plate 64 so that posts 66 and posts 220 bracket blades 182 and 184.
As the upper contact members 178-U move down, blades 182-U thereon pass directly in front of posts 60 on plate 58. As will be recalled, blades 182-U on the upper contact members are bracketed by posts 126 on plate 124 of the connector support assembly 110. Blades 182-U pass directly behind posts 74 on plate 72.
The second sides 186 and bights 190 move down onto posts 74, these posts being received in wide slots 188.
Blades 184-U pass directly in front of legs 80 on posts 74 and directly behind posts 90 on plate 88.
The lower platforms, 176-L, follow in the same path as the terminal sections 180 on the lower contact members 178-L; i.e., through the several slots defined by posts 68 (plate 64) and posts 74 (plate 72).
Further downward movement brings the signal and drain wires into contact with the wire-receiving slotted blades.
With respect to the lower contact members 178-L, first the drain wires 202, which initially were positioned across the several slots, are pushed down by the blades; i.e., the wires enter the funnel-shaped opening 193 but are stopped by the narrower slots 192 due to the lack of force on them initially. Further downward travel brings the wires into contact with the bottoms or bases of three slots, 62 (plate 58), 76 (plate 72) and 92 (plate 88). As the blades continue to move downwardly, the now stopped wires are staked or forced into the narrower portions of wire-receiving slots 192 on blades 182 and 184. Note that the wide slot 188 in second sides 186 and bights 190 permit blade 184 to travel down far enough to drive the wire to the bottom of the slot.
The upward forces created by the aforementioned staking operation are exerted on blades 182 and 184 and tends to cause them to move laterally. The posts 66 and 220 which bracket blades 182 and 184 respectively, restrain the two blades from such movement. The upward forces further push on platforms 176-L. That force is counteracted by downward pressure exerted on the top of the platforms by posts 126 (plate 124) and 136 (plate 134) on the connector support assembly 110.
Simultaneously, the signal wires 200 are being staked into the blades on the upper contact members 178-U. The comb 50 aligns the signal wires across the tops of posts 60 on plate 58, post 74 on plate 72 and posts 90 on plate 88.
As blades 182-U move down inbetween posts 60 and 74 the wires spanning the space between are driven into the wire-receiving slots. Concurrently as blades 184 move down inbetween posts 74 and 90, the wires are driven into the slots on those blades. Note that the T-shaped posts 74 move into the wide slot 188 on sides 186 and bights 190, thereby bringing the legs 80 on posts 74 close to the wire-receiving slot 192 in blades 184.
Lateral restraint is imposed on the blades on the upper contact members by virtue of being bracketed by posts 126 on plate 124 and posts 136 on plate 134. Upper pressure on platforms 176-U is counteracted by plates 132 and 140. As will be recalled, these plates are in connector support assembly 110.
FIG. 9 is a drawing showing cable 198 terminated to connector 172. As is well known, excellent electrical termination and mechanical gripping is achieved using the wire-in-slot technique.
While ribbon coax cable termination is the prime objective of this invention, it can also be seen that any cable having parallel wires can be terminated in the tool of the present invention. Further, the stripping of the cable does not require stripping of the wires per se to bare metal. As is well known, the wire-receiving slots have the capability of cutting through insulation. Accordingly wires coated with an enamel for example do not require that the enamel be removed beforehand. Note also that the connector need not have two rows; i.e., a single row connector can be terminated as well.
The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as some modifications will be obvious to those skilled in the art. | The invention relates to a tool and a method for simultaneously staking a plurality of wires into an electrical connector of the type having two rows of contact members, one row overlying the other. More particularly, the tool includes a connector support assembly on the moving ram member. This moving assembly holds the connector so that the openings of the wire-in-slot blades face downwardly. A wire support assembly is positioned on the lower, stationary member. The wires to be staked into the contact members are dressed across a series of plates having functionally-related posts and slots. The connector is brought down onto the stationary assembly which supports the wires so that the wire-in-slot blades may be pushed onto them. Both assemblies include lateral restraining members which confine the blades during the staking operation. | 8 |
RELATED APPLICATIONS
The present application is related to co-pending U.S. Patent Application entitled, “Enhanced Rapid Real Time Kinematics Determination Method and Apparatus,” by the present inventors, assigned to the present assignee, hereby incorporated herein by reference in its entirety and concurrently filed on even date herewith.
FIELD OF THE INVENTION
The present invention relates to a method of and apparatus for an improved real time kinematics (RTK) determination.
BACKGROUND
The standard mode of precise differential positioning uses one reference receiver located at a station whose coordinates are known, while determining a second receiver's coordinates relative to the reference receiver. In addition, the second receiver may be static or moving, and carrier phase measurements must be used to assure high positioning accuracy. This is the basis for pseudo-range-based differential global positioning system (GPS) (DGPS for short) techniques. However, for high precision applications, the use of carrier phase data comes at a cost in terms of overall system complexity because the measurements are ambiguous, requiring that ambiguity resolution (AR) algorithms be incorporated as an integral part of the data processing software.
Such high accuracy techniques result from progressive research and development (R&D) innovations, subsequently implemented by GPS manufacturers in top-of-the-line “GPS surveying” products. Over the last decade, several significant developments have resulted in the high accuracy performance also being available in “real-time”—that is, in the field, immediately following measurement, and after the data from the reference receiver has been received by the (second) field receiver for processing via a data communication link (e.g. very high frequency (VHF) or ultra high frequency (UHF) radio, cellular telephone, frequency modulation (FM) radio sub-carrier or satellite communication link). Real-time precise positioning is even possible when the GPS receiver is in motion through the use of “on-the-fly” (OTF) AR algorithms. These systems are commonly referred to as “real-time kinematic” (RTK) systems, and make feasible the use of GPS-RTK for many time-critical applications, e.g. machine control, GPS-guided earthworks/excavations, automated haul truck operations, and other autonomous robotic navigation applications.
If the GPS signals were continuously tracked (loss-of-lock never occurred), the integer ambiguities resolved at the beginning of a survey would be valid for the whole GPS kinematic positioning span. However, the GPS satellite signals are occasionally shaded (e.g. due to buildings in “urban canyon” environments), or momentarily blocked (e.g. when the receiver passes under a bridge or through a tunnel), and in these circumstances the integer ambiguity values are “lost” and must be re-determined or re-initialized. This process can take from a few tens of seconds up to several minutes with present OTF AR techniques. During this “re-initialization” period, the GPS carrier-range data cannot be obtained and there is “dead” time until sufficient data has been collected to resolve the ambiguities. If GPS signal interruptions occur repeatedly, ambiguity re-initialization is, at the very least, an irritation, and, at worst, a significant weakness of commercial GPS-RTK positioning systems (see upper plot in FIG. 1 ). In addition, the longer the period of tracking required to ensure reliable OTF AR, the greater the risk that cycle slips occur during the crucial (re-)initialization period. A loss of lock of a receiver phase lock loop causing a sudden integer number of cycles jump in a carrier phase observable is known as a cycle slip. Receiver tracking problems or an interrupted ability of the antenna to receive satellite signals causes the loss of lock. These shortcomings are also present in any system based on data post-processing as well.
A goal of all GPS manufacturers is to develop a real-time precise GPS positioning system, able to deliver positioning results on demand, in as easy and transparent a manner as is presently the case using pseudo-range-based DGPS techniques, which typically deliver positioning accuracies ranging from 1 to 10 meters. The ambiguity initialization period must be kept as short as possible, or even to the extreme case “instant”. Three general classes of AR techniques have been developed in the last decade: search techniques in the measurement domain; search techniques in the coordinate domain, and; search techniques in the estimated ambiguity domain using least squares estimation. In general, AR OTF using these techniques requires several epochs of data, causing a time delay for real-time applications. An integrated technique was then developed to take advantage of most positive characteristics from all three general classes of AR techniques, such as search efficiency or reliability, and hence make instantaneous AR more certain (Han & Rizos, “Integrated Method for Instantaneous Ambiguity Resolution Using New Generation GPS Receivers,” IEEE PLANS '96, (April, 1996), pp. 254–261. However, due to the smaller degrees-of-freedom in comparison to AR OTF, quality control is a very important issue. A three-step quality control procedure was further developed to solve these problems (Han, “Quality Control Issues Relating to Ambiguity Resolution for Real-Time GPS Kinematic Positioning,” Journal of Geodesy, Official Journal of the International Association of Geodesy (1997) 71(6), pp. 351–361.
There is a need in the art for an improved method of processing GPS signals to rapidly achieve high accuracy, reliable position determination. Further, there is a need in the art to apply quality control mechanisms to improve the position determination method.
SUMMARY
It is therefore an object of the present invention to provide a method of processing GPS signals for high accuracy, reliable position determination.
Another object of the present invention is to apply quality control mechanisms to improve a method of position determination.
An RTK (RTK) system of the present invention uses an integrated method incorporating a three-step quality control procedure using validation criteria. The integrated method combines the search procedures in the coordinate domain, the observation domain and the estimated ambiguity domain, and uses data from GPS receivers. The three-step procedure for enhancing the quality of AR is as follows. First, the stochastic model of the double-differenced functional model is improved. Second, discriminate between the integer ambiguity sets generating the minimum quadratic form of the residuals and the second minimum one. Third, perform the fault Detection, Identification and Adaptation procedure in which some global measures, e.g. TEC values, are used. If the AR is unsuccessful, the adaptation procedure eliminates the identified outlier observations and improves the functional model. The performance of iRTK can be shown by the lower plot in FIG. 1 .
The functional model includes determining the reference satellite, residuals, and design matrix. The stochastic model includes variance-covariance matrix determination for measurements and the variance-covariance matrix for dynamic noise in Kalman filtering.
A primary object of the present invention is to provide data processing techniques providing centimeter positioning accuracy once dual frequency GPS receivers track over 5 satellites. To improve the computational efficiency and to improve the reliability of the procedure, advances in data functional and stochastic modeling, validation criteria, adaptation and system design had to be made. None of the improvements on their own deliver the performance required, but the advance required the sum of combining the present novel techniques.
1. Stochastic Model
The RTK technique requires available dual frequency pseudo-range and carrier phase measurements. On-the-fly RTK might not necessarily need pseudo-range measurements because the float solution can be derived by the change of carrier phase measurements between epochs (or Doppler measurements). However, the float solution using data from a single epoch must be derived by pseudo-range measurements. The integrated function model means modeling carrier phase measurements and also pseudo-range measurements and their stochastic features are included. The stochastic model for carrier phase measurements and pseudo-range measurements, especially the ratio between standard deviations of carrier phase and pseudo-range, significantly affects the float solution and subsequently affects the RTK performance. The present invention provides appropriate stochastic models for both carrier phase and pseudo-range to enhance RTK performance.
2. Validation Criteria
Reliable results are dependent on the appropriateness of the stochastic model of the observations with respect to the functional model. The rejection criteria should be employed in order to check the fidelity of the stochastic and functional models. The main criterium is the ratio testing. The reliability was mainly controlled by the ratio testing criteria. This invention gives a validation criteria which were built up based on different cases, e.g. based on baseline length and/or based on the open or canopy environment. For each case, the same validation criteria functions are used. The validation criteria function is dependent on the number of satellites, baseline length, preset reliability, time-to-try and an ionosphere activity indicator. Moreover, this invention gives different validation criteria for different preset reliability levels. The criteria matrix and some parameters can be tuned based on the type of receiver used.
3. Adaptation
If the resolved integer ambiguities are wrong, in general the wrong integer ambiguities refer to more than one satellite, and it is almost impossible to identify which ambiguity is incorrect. The present invention provides an adaptation procedure to overcome this problem. Moreover, the flexible Kalman resets are used to make sure that the wrong ambiguity fixing is detected and adapted very quick.
4. Innovative System Design
The GPS RTK system is designed in both time-tagged mode and fast RTK mode. The time-tagged mode provides positioning results once the measurements from the base receiver arrive. The position latency varies at approximately 1 second and the position update is limited. The fast RTK mode provides positioning results once the measurements from the rover receiver are obtained using the predicted base station corrections. The position latency from fast-RTK is below 20 ms; however, the positioning accuracy of fast-RTK is worse than time-tagged mode. How to reduce time-tagged mode latency and increase positioning update rate are the challenge for current GPS RTK systems. The present invention provides a way to reduce data transmission latency and increase the positioning update rate to 5–10 Hz (dependent on data links) without degrading the positioning accuracy for time-tagged mode.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention.
DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:
FIG. 1A is a graph of position errors in estimates from prior art RTK systems;
FIG. 1B is a graph of position errors in estimates from an embodiment of the present invention;
FIGS. 2A–2F are graphs of criteria values with respect to pre-set reliabilities;
FIGS. 3A and 3B are radial coordinate graph plots depicting an open environment and a canopy environment, respectively;
FIG. 4 is a high level flow diagram of a process according to an embodiment of the present invention;
FIG. 5 is a flow diagram of a portion of the FIG. 4 flow diagram according to an embodiment of the present invention; and
FIG. 6 is a computer system on which an embodiment of the present invention may be used.
DETAILED DESCRIPTION
The enhanced RTK system of the present invention uses an integrated method incorporating a three-step quality control procedure. The integrated method combines the search procedures in the coordinate domain, the observation domain and the estimated ambiguity domain, and uses data from GPS receivers. The three-step procedure for enhancing the quality of ambiguity resolution is as follows. First, the stochastic model for the double-differenced functional model is improved in real-time. Second, the integer ambiguity sets which generate the minimum quadratic form of the residuals are discriminated from the second minimum quadratic form of residuals. An embodiment of the present invention uses a method deriving an empirical formula based on the different cases defined by baseline length in good or bad environments. Use of the method of the present invention overcomes the problem of the ratio test having no restrictive statistical meaning. Third, the method uses a fault detection, identification, and adaptation procedure. In this step, several receiver autonomous integrity monitoring algorithms were used, e.g. residual test, chi-square test, etc. Based on an unsuccessful ambiguity resolution, the adaptation procedure eliminates the identified outlier observations and improves the functional model, or executes a different type of Kalman filtering resets. The decision of whether to improve the functional model or execute the Kalman filtering reset is determined by receiver autonomous integrity monitoring algorithms and validation tests.
Functional Model
The relationship between carrier phase measurements and unknown parameters are derived using the following equations:
λ 1 ∇Δφ 1 =∇Δρ+λ 1 ∇ΔN 1 −∇Δd ion +(1+ε)·∇Δd trop +ε ∇Δφ 1 Equation 1A
λ 2 ∇Δφ 2 =∇Δρ+λ 2 ∇ΔN 2 −f 1 2 /f 2 2 ·∇Δd ion +(1+ε)·∇Δd trop +ε ∇Δφ 2 Equation 1B
and pseudo-range measurements are derived using the following equations:
∇Δ P 1 =∇Δρ+∇Δd ion +(1+ε)·∇Δ d trop +ε ∇ΔP 1 Equation 2A
∇ΔP 2 =∇Δρ+f 2 2 /f 2 2 ·∇Δd ion +(1+ε)·∇Δ d trop +ε ∇ΔP 2 Equation 2B
where:
Δ is a single differenced operator between receivers; ∇ is a single differenced operator between satellites; ∇Δφ and ∇ΔP are double differenced carrier phase measurements and pseudo-range measurements; ∇ΔN is a double differenced integer ambiguity; ∇Δρ is a double differenced geometric distance between satellite and antenna physical phase center; ∇Δd ion i and ∇Δd ion j are double differenced ionosphere delays; ∇Δd trop i and ∇Δd trop j are double differenced troposphere delays; ε is a scale factor of the troposphere delay computed based on models; and
ε ∇Δφ 1 , ε ∇Δφ 2 , ε ∇ΔP 1 , and ε 59 ΔP 2 are noise for L 1 , L 2 carrier phase, and pseudo-range measurements in meters. f 1 and f 2 are frequencies of L 1 and L 2 carrier signals, respectively.
Antenna position, ionosphere delay for each satellite, troposphere scale factor and integer ambiguities can be optionally set as unknown parameters in the optimal estimation system.
Stochastic Model
The measurement and modeling errors consist of measurement noise, multipath, ionosphere delay, troposphere delay, orbit bias, inter-channel bias and antenna offset and additional error sources indicated from warning messages. The warning message is received from a GPS receiver channel processing component which includes measurement quality, cycle slip flags etc. These biases are classified into two categories: distance-dependent biases and distance-independent biases. The biases are derived using the following equations:
R non-dist 2 =R noise 2 +R MP 2 +R wm 2 Equation 3A
R dist 2 =R ion 2 +R trop 2 +R orb 2 Equation 3B
Errors from inter-channel bias, antenna offset, etc. are assumed to be cancelled through double differencing in the above equations and only errors remaining in double differenced measurements are taken into account.
The standard deviation for errors from multipath and noise are derived using the following equations:
R non-dis,pseudorange 2 =σ P 2 ·(1.0+2.5·exp(− E/ 15)) Equation 4A
R non-dist,phase 2 =σ 100 2 ·(1.0+7.5·exp(− E/ 15)) Equation 4B
where E is the satellite elevation. The stochastic model is dependent on a multipath template index and is pre-set in the RTK system. The default values of σ P and σ φ for medium multipath or lower are σ P =1.5 m and σ φ =0.02 cycles. It is to be understood by those skilled in the art that the preset multipath template index may be modified by issuing appropriate commands.
The variance-covariance matrix for double differenced measurements from the distance-independent errors is also derived based on the variance-covariance matrix of measurement noise and double differenced operator. The double differenced operator is a transformation matrix which transfer one way measurements to double differenced measurements.
Significant distance-dependent errors are removed through a differencing operator between receivers. The remaining errors of the ionosphere delay, troposphere delay and orbit bias are represented as a function of the distance between receivers. The default model is 1.5 ppm·distance, 10 −4 ·HeightDiff+1.0 ppm·distance, and 0.1 ppm·distance for the residual ionosphere delay, troposphere delay, and orbit bias, respectively. If the distance-dependent errors are estimated in the Kalman filter state vector, the standard deviations are scaled by a factor, e.g. 0.2 or less. The variance-covariance matrix for double differenced measurements from the distance-dependent errors are derived based on the distance-dependent bias on single differenced measurements and single differenced operator which converts single differenced measurements to double differenced measurements.
The sum of the variance-covariance matrices from distance-independent errors and distance-dependent errors results in the variance-covariance matrix for double differenced measurements.
Kalman Filter Design
The Kalman filter state vector is shown in Table 1.
TABLE 1 Kalman Filtering State Vector Elements in State Vector Dimension Notes Position component X (or Easting) 1 Mandatory Velocity component X (or Easting) 1 Optional Acceleration component X (or Easting) 1 Optional Position component Y (or Northing) 1 Mandatory Velocity component Y (or Northing) 1 Optional Acceleration component Y (or Northing) 1 Optional Position component Z (or Height) 1 Mandatory Velocity component Z (or Height) 1 Optional Acceleration component Z (or Height) 1 Optional Residual troposphere delay 1 Optional Residual DD ionosphere delay Nsat-1 Optional L1 DD ambiguity Nsat-1 Optional L2 DD ambiguity Nsat-1 Optional
Transition Matrix and Dynamic Noise
Position Parameters
When the observer is nearly stationary, such as a buoy drifting at sea, or crustal dam deformation, the position could be assumed as a random-walk process. In this case, three coordinate parameters are enough in the Kalman state vector for coordinate prediction. The transition matrix and dynamic noise are determined based on random walk model using the equations below:
φ k,k-1 =e F(t k −t k-1 ) =1 Equation 5A
Q k =σ u 2 (t k −t k-1 ) Equation 5B
which is called a position model.
When the observer is not stationary but moving with nearly constant velocity, the velocity is not white noise but a random-walk process. In this case, three coordinate parameters and three velocity parameters must be included in the Kalman state vector for coordinate prediction. The transition matrix and dynamic noise can be determined based on an integrated random walk model according to the below equations:
ϕ k , k - 1 = [ 1 ( t k - t k - 1 ) 0 1 ] Equation 6 A Q k = σ u 2 [ ( t k - t k - 1 ) 3 3 ( t k - t k - 1 ) 2 2 ( t k - t k - 1 ) 2 2 ( t k - t k - 1 ) ] Equation 6 B
which is called a position-velocity model.
The position-velocity model is inadequate for cases where the near-constant velocity assumption is incorrect, that is, in the presence of severe or greater than nominal accelerations. Another degree of freedom is added for each position state becoming a Position-Velocity-Acceleration model or a Gauss-Markov process in place of the nonstationary random walk model for acceleration.
The specific model used depends on the intended application. For extremely high dynamic motion applications, the dynamic noise increases even using a Position-Velocity-Acceleration model. In this case, the dynamic noise compensates for errors which are not accounted for in the model. Spectral amplitude determination for position random processes is estimated based on expected vehicle dynamics. In many vehicular applications, the random perturbations are greater in the horizontal plane than in the vertical and are accounted for by selecting a lower spectral amplitude value for an altitude channel than for the other two horizontal channels.
Ambiguity Parameters
The transition matrix and dynamic noise for ambiguity parameters in Kalman state vector are derived using the following equations:
φ k,k-1 =e F(t k −t k-1 ) =1 Equation 7A
Q k =0 Equation 7B
Troposphere Scale Parameter
The troposphere scale parameter ε represents the percentage change of the troposphere delay. For a particular location, the troposphere delay for all satellites is scaled by the same factor independent of the satellite elevation and includes some approximation. Empirically, the scale factor is modeled as a Gauss-Markov process. The transition matrix and dynamic model is then derived using the following equations:
φ k,k-1 =e −β trop (t k −t k-1 ) Equation 8A
Q k =σ t trop 2 (1 −e −2β trop (t k −t k-1 ) ) Equation 8B
where 1/β trop is the correlation time of the troposphere wet component and σ 2 trop represents the wet component changing level, which are a function of the baseline length and the height difference.
Ionosphere Delay Parameters
The ionosphere delay difference between both ends of a baseline is specified as an unknown parameter in the Kalman filter state vectors and is a function of the local time, ionosphere activities, distance and direction of two intersections of the receiver-satellite rays with equivalent ionosphere layer from both ends of the baseline. Empirically, the ionosphere delay difference is estimated by a Gauss-Markov model. The transition matrix and dynamic model are expressed using the following equations:
φ k,k-1 =e −β ion (t k −t k-1 ) Equation 9A
Q k =σ i 2 (1 −e −2β ion (t k −t k-1 ) ) Equation 9B
where 1/β ion is the correlation time of single differenced ionosphere delay and σ 2 ion represents the variation level of the delay.
Ambiguity Resolution
The double differenced float solution and the variance-covariance matrix of these elements are extracted using Kalman filtering and are then provided to an ambiguity search procedure based on double differenced ambiguity Δ∇N and variance-covariance matrix D Δ∇N . The double differenced ambiguity is first decorrelated using a LAMBDA transformation approach.
After the decorrelation procedure, the ambiguity searching procedure is performed with the goal of finding an integer ambiguity set Δ∇n meeting the criteria below:
(Δ∇ N−Δ∇n ) T D Δ∇N −1 (Δ∇ N−Δ∇n )=min Equation 10
A detailed search procedure usable in conjunction with an embodiment of the present invention is described by equations (42–47) in Han & Rizos, “A New Method for Constructing Multi-satellite Ambiguity Combinations for Improved Ambiguity Resolution,” Proceedings of ION GPS -95, 8 th International Technical Meeting of The Satellite Division of The Institute of Navigation (1995), pp. 1145–1153. Once the integer ambiguity set deriving the minimum value of the above quadratic form is derived, the integer ambiguity set is verified by the ratio value of the minimum value and the second minimum value. If the ratio value is greater than the specified validation criteria, then the integer ambiguity set deriving the minimum value is identified as the solution for the ambiguity set. If the validation criteria is greater than the ratio value, the integer ambiguity set is rejected and the set of possible ambiguity fix solutions is reduced. On the other hand, if the validation criteria is set too small, the resultant integer ambiguity set might not be the correct one and the ambiguity fixed solution will be wrong. Therefore, validation criteria determination is key for improving RTK performance.
Once the integer ambiguities are fixed the corresponding rows and columns in the variance-covariance matrix are replaced with zeros. In this sense, ambiguity fixing means that the unknown initial integer cycles of the corresponding carrier phase measurements have been determined and the carrier phase measurements have been corrected by integer numbers.
Validation Criteria
Reliable results are dependent on the appropriateness of the stochastic model of the observations with respect to the functional model. The validation criteria are used to check the fidelity of the stochastic and functional models. Outlier detection, identification, and adaptation are important algorithmic tasks to increase the opportunity for ambiguity fixing as quick as possible. In fact, outliers or significant errors in pseudo-range or carrier phase measurements bias the float ambiguity estimation and, hence, offset the quadratic form of residuals. Once outliers are detected, identified and adapted through functional modeling and/or stochastic modeling, the correct integer ambiguity set is then successfully identified from other integer ambiguity sets.
A large number of integer ambiguity sets are included in the search region in the estimated ambiguity domain based on the results of the ambiguity float solution. A series of validation criteria are used to distinguish the correct integer ambiguity set from other integer ambiguity sets. The validation criteria are required to minimally accept wrong integer ambiguity sets and maximally accept the correct ambiguity set. Reliability is defined as the ratio between the number of correct solutions and the total number of solutions, which is controlled by validation criteria. Meeting the reliability requirement has the highest priority for determining whether the positioning solution is accepted or not, rather than time-to-fix. Time-to-fix is the resultant parameter indicating the length of the observation span required to select the integer ambiguity set.
The validation criteria and settings are developed based on different categories of data, e.g. based on baseline length and/or based on an open or canopy environment. For each category, we used the same validation criteria functions. The validation criteria function is dependent on the number of satellites, baseline length, preset reliability, time-to-try and an ionosphere activity indicator. Therefore, the validation criteria function is an empirical formula which is finalized using different data sets. The greater the number of typical data sets used, the more reliable are the coefficients of the empirical formula.
For each pre-set reliability, the following equation of baseline length and time-to-try can be fitted in each case classified based on ionosphere activities and environment conditions.
F ( t , d ) = { f ( d ) t <= t 1 f ( d ) - 2 · ( f ( d ) - f ( 0 ) ) ( t 2 - t 1 ) 3 · t 1 < t < t 2 ( 3 2 ( t 2 - t 1 ) ( t - t 1 ) 2 - ( t - t 1 ) 3 ) f ( 0 ) t >= t 2 Equation 11
where f(d) is a function of baseline length d according to the following equation:
f ( d ) = { f min d <= d 1 f min + 2 · ( f max - f min ) ( d 2 - d 1 ) 3 · d 1 < d < d 2 ( 3 2 ( d 2 - d 1 ) ( d - d 1 ) 2 - ( d - t 1 ) 3 ) f max d >= d 2 Equation 12
where t is the time-to-try starting from a first initialization epoch and d is the baseline length in kilometers.
If there are enough samples, t 1 , t 2 , d 1 and d 2 are estimated in addition to f min and f max . However, in the more frequent embodiment, t 1 , t 2 , d 1 and d 2 are empirically chosen to simplify the procedure, e.g. t 1 =20 s, t 2 =140+d*30 s, d 1 =3 km and d 2 =7 km in the RTK system for short-range applications. At least two baselines (one shorter than d 1 and the other longer than d 2 ) are required to tune f min and f max . As more baselines are used, the reliability of the estimation increases. Therefore, two numbers, f min and f max , are derived for each case. For example, the following matrix is derived for normal ionosphere activity and open environment, normal ionosphere activity and canopy environment, severe ionosphere activity and open environment, and sever ionosphere activity in canopy environment.
TABLE 2
f max values for normal ionosphere activity and good environment
5
6
7
8
9
10 or more
95%
3.0
2.75
2.5
2.0
2.0
1.75
99%
4.5
4.00
3.5
2.5
2.5
2.5
99.9%
5.0
4.50
4.5
3.5
3.0
3.0
TABLE 3
f min values for normal ionosphere activity and good environment
5
6
7
8
9
10 or more
95%
2.5
2.25
2.0
1.75
1.5
1.5
99%
3.0
2.75
2.5
2.0
2.0
2.0
99.9%
4.0
3.5
3.0
2.5
2.5
2.5
FIG. 2 depicts the criteria value as a function of reliability criteria, satellite number, baseline length and observation time used to derive a float solution. The top, middle, and bottom plots depict reliability levels at 99.9%, 99%, and 95%, respectively.
Based on normal or severe activity and open or canopy environment, the appropriate validation criteria table is picked. Based on the number of satellites, pre-set reliability, the appropriate maximum and minimum values are selected. Based on the baseline length and time-to-try, the validation criteria value is calculated using the selected maximum and minimum values.
In performing a check for an incorrect fix, either true ambiguities or true position must be known. If the true ambiguities are obtainable using post-processing software, making a comparison to determine whether an ambiguity fix is correct or not is easier to perform. If the baseline vector is known, the difference between derived coordinates and known coordinates should be less 8 cm+1 ppm and 12 cm+1.5 ppm for horizontal components and vertical components, respectively, but not over 12 cm and 18 cm. In this application, ppm means increase 1 mm per kilometer.
Based on the calculated vertical electron content (VEC) value from the broadcast ionosphere model, the ionosphere activity can be classified as either normal and severe ionosphere activity.
If 50% of directions are blocked over 30 degrees in elevation, the environment is defined as a canopy environment. Otherwise, the environment is defined as an open environment. The left skyplot in FIG. 3 depicts an open environment and the right skyplot depicts a canopy environment.
Adaptation
If the resolved integer ambiguities are incorrect, in general the incorrect integer ambiguities refer to more than one satellite, and the incorrect ambiguity is almost impossible to identify. However, the fact that some biases are present in the observations can be confirmed.
If instantaneous ambiguity resolution is required, the minimum number of satellites required is five. If six or more satellites are observed, some of the observations are eliminated. Because the outliers are not located, all combinations of five or more satellites from all observed satellites are tested. This procedure has been implemented in software by eliminating one (or more) satellite (at least five satellites are kept), starting with the lowest elevation satellite observation. If the ambiguity resolution fails, the procedure is repeated until ambiguity resolution is successful. If all possible sets of five or more satellites are combined and ambiguity resolution still fails, the ambiguity resolution procedure is considered to have failed. This procedure ensures that the ambiguity resolution success rate increases significantly.
The adaptation also includes a stochastic model adaptation based on the real environment and a Kalman filtering reset. The stochastic model parameter will be adapted using post-fit residuals in real-time.
Process Flow
FIG. 4 depicts the process flow of an RTK method according to an embodiment of the present invention. Low rate, nominally 1 Hz, base station measurements output from a base data decoder 400 are output to a polynomial fitting function executed in a phase predictor process 402 , e.g. second order or higher order polynomial, and a Kalman filter process 408 . Base data decoder 400 decodes raw GPS measurements received from a base GPS receiver (not shown). The sampling rate (or update rate) of base data decoder 400 is nominally 1 Hz. Higher sampling rates may be used with a proportional increase in cost and baud rate for the data link. In one embodiment of the present invention, the update rate does not exceed 1 Hz. If a higher sampling rate is required, an embodiment according to the description embodied in co-pending patent application titled, “Enhanced Rapid Real-Time Kinematic Determination Method and Apparatus,” by the present inventors and assigned to the present assignee would be used.
In order to reduce the position update time delay, phase predictor process 402 predicts corrections for the position calculation using available corrections transmitted from the base GPS receiver as decoded and output from base data decoder 400 in conjunction with polynomial filtering. The positioning accuracy degrades depending on the length of the predicted period.
Kalman filter process 408 , described in detail below with reference to FIG. 5 , calculates optimal solutions, i.e. position and/or velocity, based on currently available measurements from base data decoder 400 and rover data decoder 404 . An ambiguity resolution process 410 is a part of Kalman filter process 408 and is described in detail below with reference to FIG. 5 .
A rover data decoder 404 decodes raw GPS measurements and ephemeris received from the rover GPS receiver (not shown) and provides time tagged carrier phase measurements to a carrier phase process 406 . The sampling rate (or update rate) of rover data decoder 404 can be up to 10 Hz or higher.
Output estimated polynomial parameters from phase predictor 402 are used by carrier phase process 406 to predict the base station measurement at a rate matching the RTK update rate, typically 10 Hz or higher. The RTK solution latency is primarily determined by the rover measurement data collection time and the RTK position computation time. The base station prediction time is a negligible delay. Typically, RTK solution latency is less than 20 milliseconds depending on microprocessor speed.
For embodiments requiring an update rate in time-tagged mode of 1 Hz or lower, carrier phase process 406 uses the output from Kalman filter 408 to calculate and output the rover GPS receiver position and/or velocity. For embodiments requiring an update rate in RTK mode of 1 Hz or lower, carrier phase process 406 uses the most recent measurements from rover data decoder 404 and the predicted correction output from phase predictor 402 to calculate and output the most recent position and/or velocity of the rover GPS receiver.
To reduce the RTK position computation time, only an L 1 carrier phase measurement output from a rover data decoder 404 is used. The rover L 1 carrier phase measurement and the predicted base station L 1 carrier phase measurement output from phase predictor 402 are then used to derive L 1 double difference measurements in 406 . The estimated L 1 integer ambiguities, residual ionosphere delay, residual troposphere delay and other bias parameters are used to correct the double difference measurement in 406 . The corrected double difference measurement is output into a least squares (LSQ) estimator to calculate a rover position in 406 . The velocity is calculated in a similar manner using rover L 1 Doppler measurements and predicted base L 1 carrier phase rate. Because of the requirement of base station measurement prediction, the RTK solution accuracy is degraded in comparison to a matched time-tag RTK solution. With Selective Availability (S/A), the rate of degradation increases due to the inability to predict S/A. Selective availability is known to persons of skill in the art and refers to the intentional degradation of the absolute positioning performance capabilities of the GPS for civilian use accomplished by artificial “dithering” of satellite clock error.
With reference to FIG. 5 , details of Kalman filter process 408 and ambiguity resolution process 410 in FIG. 4 are now described. Data from both a base GPS receiver (not shown) and a rover GPS receiver (not shown) is received, decoded, and output by base data decoder 400 and rover data decoder 404 , respectively. Base data 500 and rover data 502 time tags are matched in match time tag step 504 , thereby matching the time when the respective measurements were made.
After the time tags are matched, the matched data output from match time tag step 504 is input to a Kalman filter. In step 506 , if the matched data output is in the first epoch or if a reset of the Kalman filter is required, the Kalman filter is initialized in step 506 . In step 508 , a reference satellite is selected to determine the double differenced measurement. Further, cycle slips are checked using cycle slip flags and a stochastic model is calculated.
The flow proceeds to step 510 for the preparation of the design matrix, variance-covariance matrix (stochastic model) and calculation of pre-fit residuals for all measurements, e.g. C/A pseudo-range, P 1 pseudo-range, P 2 pseudo-range, L 1 Doppler, L 2 Doppler, L 1 carrier phase and L 2 carrier phase measurements. The output of the pre-fit residual calculation is input to a Receiver Autonomous Integrity Monitoring (RAIM) algorithm to detect outliers. RAIM is a form of receiver self-checking using redundant pseudo-range observations to detect if a problem with any of the measurements exists.
The output of step 510 is provided as input to a Kalman filter measurement update step 512 to sequentially filter all measurements and provide filtered output measurements to an ambiguity resolution step 514 . The update step provides the optimal estimation results using all available measurements.
The validation criteria are calculated using the above-described method in step 514 and a determination of whether the integer ambiguities can be fixed or not is performed in step 516 . If the step 516 determination is positive (the integer ambiguities can be fixed), the float solution is updated to the fix solution in step 518 . If the step 516 determination is negative (the integer ambiguities cannot be fixed), the above-described adaptive fix procedure is performed in step 520 to attempt to fix ambiguities and a second determination of whether the integer ambiguities can be fixed or not is performed in step 522 . If the step 522 determination is positive (the integer ambiguities can be fixed), the float solution is updated to the fix solution in step 518 and the flow proceeds to step 524 wherein the post-fit residuals are updated and possible outliers are detected. If the step 522 determination is negative (the integer ambiguities cannot be fixed), the flow proceeds to step 524 described above.
The output of step 524 is provided to a Kalman filtering time update 526 , which is a Kalman filtering prediction step. In step 528 , all necessary information is outputted and in step 530 the measurements are stored and the processing information is updated based on the above-described method. The flow proceeds to process the next epoch of data returning to step 504 .
In coordination with the above-described technique, an embodiment of the present invention provides an improved method of and apparatus for determining real time kinematics, and more specifically determines the kinematics in an accurate manner.
FIG. 6 is a block diagram illustrating an exemplary computer 600 upon which an embodiment of the invention may be implemented. The present invention is usable with currently available handheld and embedded devices, e.g. GPS receivers, and is also applicable to personal computers, mini-mainframes, servers and the like.
Computer 600 includes a bus 602 or other communication mechanism for communicating information, and a processor 604 coupled with the bus 602 for processing information. Computer 600 also includes a main memory 606 , such as a random access memory (RAM) or other dynamic storage device, coupled to the bus 602 for storing GPS data signals according to an embodiment of the present invention and instructions to be executed by processor 604 . Main memory 606 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 604 . Computer 600 further includes a read only memory (ROM) 608 or other static storage device coupled to the bus 602 for storing static information and instructions for the processor 604 . A storage device 610 (dotted line), such as a compact flash, smart media, or other storage device, is optionally provided and coupled to the bus 602 for storing instructions.
Computer system 600 may be coupled via the bus 602 to a display 612 , such as a cathode ray tube (CRT) or a flat panel display, for displaying an interface to the user. An input device 614 , including alphanumeric and function keys, is coupled to the bus 602 for communicating information and command selections to the processor 604 . Another type of user input device is cursor control 616 , such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 604 and for controlling cursor movement on the display 612 . This input device typically has two degrees of freedom in two axes, a first axes (e.g., x) and a second axis (e.g., y) allowing the device to specify positions in a plane.
The invention is related to the use of computer 600 , such as the depicted computer of FIG. 6 , to perform accurate, real-time, kinematics determination. According to one embodiment of the invention, data signals are received via a navigation interface 619 , e.g. a GPS receiver, and processed by computer 600 and processor 604 executes sequences of instructions contained in main memory 606 in response to input received via input device 614 , cursor control 616 , or communication interface 618 . Such instructions may be read into main memory 606 from another computer-readable medium, such as storage device 610 . A user interacts with the system via an application providing a user interface displayed on display 612 .
However, the computer-readable medium is not limited to devices such as storage device 610 . For example, the computer-readable medium may include a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a compact disc-read only memory (CD-ROM), any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a random access memory (RAM), a programmable read only memory (PROM), an erasable PROM (EPROM), a Flash-EPROM, any other memory chip or cartridge, a carrier wave embodied in an electrical, electromagnetic, infrared, or optical signal, or any other medium from which a computer can read. Execution of the sequences of instructions contained in the main memory 606 causes the processor 604 to perform the process steps described above. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with computer software instructions to implement the invention. Thus, embodiments of the invention are not limited to any specific combination of hardware circuitry and software.
Computer 600 also includes a communication interface 618 coupled to the bus 602 and providing two-way data communication as is known in the art. For example, communication interface 618 may be an integrated services digital network (ISDN) card, a digital subscriber line (DSL) card, or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 618 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface 618 sends and receives electrical, electromagnetic or optical signals which carry digital data streams representing various types of information. Of particular note, the communications through interface 618 may permit transmission or receipt of instructions and data to be processed according to the above method. For example, two or more computers 600 may be networked together in a conventional manner with each using the communication interface 618 .
Network link 620 typically provides data communication through one or more networks to other data devices. For example, network link 620 may provide a connection through local network 622 to a host computer 624 or to data equipment operated by an Internet Service Provider (ISP) 626 . ISP 626 in turn provides data communication services through the world wide packet data communication network now commonly referred to as the “Internet” 628 . Local network 622 and Internet 628 both use electrical, electromagnetic or optical signals which carry digital data streams. The signals through the various networks and the signals on network link 620 and through communication interface 618 , which carry the digital data to and from computer 600 , are exemplary forms of carrier waves transporting the information.
Computer 600 can send messages and receive data, including program code, through the network(s), network link 620 and communication interface 618 . In the Internet example, a server 630 might transmit a requested code for an application program through Internet 628 , ISP 626 , local network 622 and communication interface 618 .
The received code may be executed by processor 604 as it is received, and/or stored in storage device 610 , or other non-volatile storage for later execution. In this manner, computer 600 may obtain application code in the form of a carrier wave.
It will be readily seen by one of ordinary skill in the art that the present invention fulfills all of the objects set forth above. After reading the foregoing specification, one of ordinary skill will be able to affect various changes, substitutions of equivalents and various other aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by the definition contained in the appended claims and equivalents thereof. | A method of and computer-readable medium containing instructions for high accuracy, reliable position determination. A high precision GPS-RTK system using the present novel techniques is initialized instantaneously or near instantaneously. To improve the computational efficiency and to improve the reliability of the procedure, advances in data functional and stochastic modeling, validation criteria, adaptation and system design were achieved. A position estimate using an integrated method is determined. Ambiguity resolution of the position estimate is enhanced by applying a quality control procedure using derived validation criteria. A second position estimate based on the enhanced ambiguity resolution is derived. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of, and claims the benefit under 35 U.S.C. § 120 of, application serial number 09/539,478, filed Mar. 30, 2000, now U.S. Pat. No 6,751,214.
BACKGROUND OF THE INVENTION
The present invention relates to improved methods and apparatus for transmitting information via a communication link. More importantly, the present invention relates to improved protocols, methods, and devices for transmitting both ATM and packet data over a transport-layer protocol such as SONET in a manner that facilitates more efficient dynamic allocation of bandwidth and traffic management.
The use of the SONET (Synchronous Optical Network) as a transport mechanism at the transport-layer for both (Asynchronous Transfer Mode) ATM and packet data is well known. As the term is employed herein, data includes any type of information that may be represented digitally, and includes such time-sensitive data such as streaming video or voice, and/or non time-sensitive data such as computer files. Packet technology includes TCP/IP, token ring, etc. One example of packet technology is IP (Internet Protocol) packets transmitted over OSI layer 2 . Another example of packet technology is Ethernet. ATM and SONET technologies are well known and well defined and will not be elaborated further here. Similarly, the various layers of the OSI 7-layer model are also well known and well defined.
Typically speaking, ATM traffic or packet traffic do not mix in the same unchannelized optical fiber, or in the same TDM channel if the optical fiber is channelized. In the former case, one may think of the entire fiber as a single channel, which is employed to transport either ATM traffic or packet traffic. To facilitate discussion, FIG. 1 is a prior art logical depiction of ATM cells transported within SONET frames in an arrangement commonly known as ATM-over-SONET in an unchannelized optical fiber. As can be seen in FIG. 1 , a plurality of ATM cells (53 bytes each) may be packed into a single SONET frames (such as in between SONET overhead blocks 102 and 104 ). Although only four full ATM cells 106 , 108 , 110 , and 114 are shown, one skilled in the art will appreciate that a typical. SONET payload may have the capacity to carry many cells. If there is no room left in a SONET frame to put an entire cell therein, the SONET circuitry may break up a cell and transport a partial cell in that SONET frame (as shown with partial cell 112 a ). The remaining portion of the cell that was broken up is then transported in the next SONET frame (as shown with partial cell 112 b ). Furthermore, if there are no ATM cells to transport in a SONET frame, idle cells are typically inserted to fill the frame. Note that since SONET operates at a lower level, as far as the ATM layer is concerned, the fact that an ATM cell was broken up and reassembled by the SONET layer is completely transparent.
FIG. 2 is a prior art logical depiction of packets transported within SONET frames in an arrangement commonly known as packet-over-SONET in an unchannelized optical fiber. Similar to the situation of FIG. 1 , a plurality of packets (which may be variable in length) may be packed into a single SONET frame (such as in between SONET overhead blocks 202 and 204 . However, since the packets may have variable lengths, flags are employed between packets to help delineate where the packets are in the data stream. With reference to FIG. 2 , these flags are shown as flags 206 , 208 , 210 , 212 , and 214 . Flag 214 is a flag inserted to fill in the frame if there is no packet data to fill. Again, if the frame is full, a packet may be broken up to be transported in different frames. This is shown with packet 216 , which is shown broken up into partial packets 216 a and 216 b and transported in two different frames. Again, since SONET operates at a lower level, as far as the packet layer is concerned, the fact that a packet was broken up and reassembled by the SONET layer is completely transparent.
In either case, the entire unchannelized optical fiber is used to transport only ATM traffic ( FIG. 1 ) or packet traffic ( FIG. 2 ). To allow ATM traffic and packet traffic to share a single optical fiber, the optical fiber may be channelized into different time division multiplex (TDM) channels. Within each channel, the traffic is again either entirely ATM or entirely packet. This situation is logically depicted in FIG. 3 .
In FIG. 3 , an STS-3 SONET transport arrangement is shown, wherein the full bandwidth of the optical fiber is channelized into three different STS-1 channels or time slots: slots 1 , 2 , and 3 . ATM cells are shown packed into slot 1 , while packets are shown packed into slot 3 to illustrate that ATM and packet traffic may occupy different channels to share the optical fiber. Again, both ATM cells and packets may be broken up for transport in parts if the bandwidth available in a slot is already full.
Prior art FIG. 4 shows, in a high level depiction, how ATM and packet data from various sources may be multiplexed into different separate channels in the same optical fiber. With reference to FIG. 4 , ATM data is destined for slot 1 , while packet data is destined for slots 2 and 3 . A multiplexer 402 takes data from the ATM stream 404 , the packet stream 406 , and the packet stream 408 , and multiplexes them using a time-division multiplexing scheme onto time slots 1 , 2 and 3 respectively. At the other end, a demultiplexer 410 demultiplexes the data into ATM stream 412 , packet stream 414 , and packet stream 416 respectively.
While the TDM multiplexing scheme of FIGS. 3 and 4 allow ATM traffic and packet traffic to share different separate channels in the same optical fiber, there are disadvantages. By way of example, within each STS-1 channel (which is 51.84 Mbps), the traffic within each channel must be either all ATM cells or all packets. Because of this limitation, the channels must be pre-allocated in advance for each type of traffic. If given type of high-priority traffic (e.g., streaming video over ATM) is assigned to a given channel or time slot, and the bandwidth requirement associated that traffic type increases beyond the capacity of the channel, transmission delay can occur. Even though the network operator can assign one or more additional channels to handle the increase in this ATM traffic, there is a nontrivial time delay associated with the detecting the congestion condition (and possibly concurrently coordinate to unallocate channels previously allocated to other non-priority traffic if there are no free channels left), coordinating with the receiving end to allocate the additional channels, and changing network parameters to allocate the additional channels to handle the increased bandwidth requirement of the high-priority traffic. As can be appreciated from the foregoing, the complex coordination, unallocation of channels and reallocation of them to the priority traffic involves a nontrivial amount of operational complexity and/or time delay. For some types of data (e.g., time-critical data), this delay is unacceptable. For this reason, many network operators tend to reserve an unduly large amount of bandwidth overcapacity to handle potential traffic increases when dealing with time-critical data, which leads to inefficient use of network bandwidth as the reserved bandwidth tends to stay unused most of the time. Furthermore, each traffic type can employ bandwidth only in a discrete, channel-size chunk. If additional bandwidth is allocated to a given traffic type, an entire slot (51.84 Mbits in case of STS-1) is added even if the increase in traffic only requires a portion of the capacity offered by an entire slot.
In view of the foregoing, there are desired improved techniques for allowing ATM traffic and packet traffic to share the bandwidth of a channel in a manner that facilitates dynamic allocation of bandwidth between traffic types and more efficient traffic management.
SUMMARY OF THE INVENTION
The invention relates to techniques for transmitting both ATM cells and packets over a single channel in an optical fiber. The technique includes providing a transport-layer device which is configured to transmit packet data on said optical fiber. The method also includes receiving the ATM cells at the transport-layer device and receiving the packets at the transport-layer device. These ATM cells and packets may come from multiple sources. The method further includes multiplexing, using the transport-layer device, the ATM cells and the packets onto the single channel for transmission. At the receiving end, innovative discrimination techniques facilitate discrimination of the ATM cells from the packets received from the single channel to allow the ATM cells and packets to be sent to their respective destinations.
The invention offers may advantages, including eliminating the need for dividing the optical fiber into separate rigid TDM channels to handle ATM and packet traffic separately therein, eliminating the need for separate optical fibers to handle ATM and packet traffic separately, more efficient traffic management and dynamic bandwidth allocation, and/or the ability to use packet-only network and switching resources to handle a mix of ATM cells and packets or even ATM cells alone.
In another embodiment, the invention relates to method for dynamically allocating bandwidth among ATM cells and packets transported in the same channel. The method includes receiving the ATM cells at an aggregation multiplexer and receiving the packets at the aggregation multiplexer. The method further includes ascertaining relative priorities of individual ones of the ATM cells and individual ones of the packets, the individual ones of the ATM cells representing ATM cells scheduled for output by the multiplexer, the individual ones of the packets representing packets also scheduled for output by the multiplexer. Additionally, the method also includes multiplexing, using the aggregation multiplexer, one of the ATM cells and the packets onto the channel, the one of the ATM cells and the packets being output having the highest relative priority among the relative priorities.
These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 is a prior art logical depiction of ATM cells transported within SONET frames in an arrangement commonly known as ATM-over-SONET in an unchannelized optical fiber.
FIG. 2 is a prior art logical depiction of packets transported within SONET frames in an arrangement commonly known as packet-over-SONET in an unchannelized optical fiber.
FIG. 3 shows a prior arrangement that allows ATM traffic and packet traffic to share a single optical fiber in separate time division multiplex (TDM) channels.
Prior art FIG. 4 shows, in a high level depiction, how ATM and packet data from various sources may be multiplexed into different separate channels in the same optical fiber.
FIGS. 5A and 5B are logical illustrations showing, in accordance with one aspect of the present invention, how both ATM cells and packets can be packed within a SONET frame.
FIG. 6 is a prior art logical illustration showing at a high level how ATM-over-SONET is accomplished at the transmitting end.
FIG. 7 is a prior art logical illustration showing how packet-over-SONET is accomplished at the transmitting end.
FIG. 8 is a logical illustration that illustrates at a high level, in accordance with one embodiment of the present invention, the transmitting circuit for aggregating both ATM cells and packets onto a single channel.
FIG. 9 is a prior art logical illustration of how ATM-over-SONET is accomplished at the receiving end.
FIG. 10 is a prior art logical illustration of how packet-over-SONET is accomplished at the receiving end.
FIG. 11 illustrates, in accordance with one embodiment of the present invention, the receiving circuit for resolving the mixed ATM/packet over SONET information into respective ATM cells and packet information.
FIGS. 12 and 13 show one advantageous application of the inventive aggregated ATM/packet over SONET transmission technique, which is within the switching facility.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail with reference to a few preferred embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
In accordance with one aspect of the present invention, there is provided an aggregated ATM/packet over SONET transmission technique for transmitting both ATM cells and packets over a channel, which may be the entire bandwidth of the optical fiber or part of the bandwidth of the optical fiber, such that the ATM bandwidth and the packet bandwidth can be dynamically allocated with substantially reduced delay and network overhead. In one embodiment, the packet-over-SONET transmission standard is extended to also allow ATM cells to be treated as if they are packets and transmitted in the SONET frame as if they are packets. Within a SONET frame, individual ATM cells and individual packets are delineated with flags of the type typically associated with the packet-over-SONET transmission standard. Since ATM cells are also delineated with flags of the type employed in the packet-over-SONET standard, the present invention is markedly different from the prior art technique of transmitting ATM cells over SONET (such as that shown in FIG. 1 ), in which flags of the type employed in the packet-over-SONET standard are not employed. Since the technique leverages on existing packet-over-SONET standards and architectures, it is highly user-friendly toward professionals who already are familiar with packet-over-SONET techniques, thereby lowering the training costs associated with implementing the inventive transmission technique. Additionally, many of the circuit components typically associated with packet-over-SONET transmission may be reused in systems that implement the inventive aggregated ATM/packet over SONET transmission technique, thereby lowering implementation and equipment production costs.
In one embodiment, the aggregation multiplexer at the transmit side, which performs the aggregation of ATM cells and packets to allow both to be transmitted over a single channel, is also endowed with traffic management capabilities to allow the aggregation multiplexer to locally decide whether an ATM cell, a particular ATM cell having a particular QoS priority, a packet, or a particular packet having a particular priority, should be multiplexed through next. As will be discussed later, this has important advantages.
As mentioned earlier, the prior art transmit either all ATM cells or all packets within a single optical fiber or within a single channel/time slot. In the channelized case in which the channels are preallocated to a particular type of traffic, the time slot from which the traffic is received yields information pertaining to whether the traffic received is ATM cells or packets. In the current invention, because ATM cells and packets are mixed within the same SONET frame, it is necessary to come up with another way to determine at the receiving end whether the received traffic is an ATM cell or a packet. In one embodiment, this decision is performed by the desegregation demultiplexer at the receiving end based on predefined desegregation criteria. Once the ATM cells and packets are separated, they may be forwarded on to their respective links to be transmitted to their respective destinations.
To facilitate discussion, FIG. 5A is a logical illustration showing, in accordance with one aspect of the present invention, how both ATM cells and packets can be packed within a SONET frame. In a nonobvious manner, the present invention treats ATM cells as if they are packets for the purpose of transporting them using a technique similar to those employed in packet-over-SONET systems yet still allows the receiving end to correctly discriminate between ATM cells and packets. Thus, ATM cells can be freely mixed with packets within the same SONET frame. With reference to FIG. 5A , both packets and ATM cells are shown in between SONET overhead blocks 502 and 504 of FIG. 5A . As before, individual packets are delineated by flags. This is illustrated by flags 506 and 508 , which delineates a packet 510 as shown. In a counter-intuitive manner, the ATM cells are also delineated with flags of the type employed in the packet-over-SONET transmission standard. With reference to FIG. 5A , the ATM cell 512 is shown delineated by flags 508 and 514 . This is so even though ATM cells are of a fixed length. The use of flags to delineate individual ATM cells is counter-intuitive since flag usage incurs bandwidth overhead, and the fact that ATM cells are always 53-byte in size mitigates against the use of flags for delineation purpose since the end of an ATM cell can be readily detected by counting bytes (which is not possible with variable-length packets). Nevertheless, the use of flags with ATM cells allows the inventive transmission system to treat ATM cells as if they are packets for the purpose of framing them within a SONET frame for transmission and yields important traffic management and cost benefits.
In FIG. 5A , it is shown that a packet 516 can be segmented for partial transmission as packet segments 516 a and 516 b in different SONET frames if there is not enough room left in one SONET frame for the entire packet 516 . In FIG. 5B , it is also shown that an ATM cell can be similarly segmented for partial transmission as ATM cell segments 518 a and 518 b in different SONET frames if there is not enough room left in one SONET frame for the entire ATM cell 518 . This is similar to what was done earlier in connection with FIGS. 1 and 2 , except that in the case of FIGS. 5A and 5B , both ATM cells and packets are mixed in the same SONET frame. Also, FIG. 5B shows an extra flag 522 being inserted into the frame. This is depicted to illustrate that like the packet-over-SONET situation, the present invention may fill up a frame with flags if there is not enough data (either ATM or packet) to fill the entire SONET frame.
FIG. 6 is a prior art logical illustration showing at a high level how ATM-over-SONET is accomplished at the transmitting end. In FIG. 6 , the ATM cells are received at the input of multiplexer 602 to be multiplexed with overhead information from overhead insert block 604 . The output of multiplexer 602 is substantially as shown in FIG. 1 .
FIG. 7 is a prior art logical illustration showing how packet-over-SONET is accomplished at the transmitting end. In FIG. 7 , the packet information is received at a scrambler 702 to be scrambled prior to being multiplexed via a multiplexer 704 with byte-stuffing information from a byte-stuffing block 706 . Byte-stuffing block 706 detects the presence of certain reserved octets in the input information, such as the Flag octet (7E hex) that delineates individual packets and Control Escape Octet (7D hex) , and replace each octet with a respective known two-octet sequence, such as the 7D5E for 7E and 7D5D for 7D. This byte-stuffing operation is done in accordance with the packet-over-SONET standard. However, since the byte-stuffing operation increases the number of bytes to be transmitted, it potentially exposes the network to a malicious bandwidth-crippling attack if someone sends a volume of packets full of the reserved character strings. Scrambler 702 , which was mentioned earlier, avoids this by scrambling the input packets. The output of multiplexer 704 is then multiplexed, via a multiplexer 708 , with flags from a flag insert block 710 , to delineate the individual packets. Generally speaking, multiplexer 708 receives the end of the packet and inserts the flag into the stream to mark where one packet ends and another begins. The output of multiplexer 708 is then multiplexed, using TDM multiplexer 714 , with overhead information from overhead insert block 712 . The output of multiplexer 714 is substantially as shown in FIG. 2 .
FIG. 8 is a logical illustration that illustrates at a high level, in accordance with one embodiment of the present invention, the transmitting circuit for aggregating both ATM cells and packets onto a single channel. In FIG. 8 , the packet information is received at a scrambler 802 to be scrambled prior to being multiplexed via an aggregation multiplexer 804 with byte-stuffing information from byte-stuffing block 806 . Both scrambler 802 and byte-stuffing block 806 work in substantially the same manner as scrambler 702 and byte-stuffing block 706 discussed earlier in connection with FIG. 7 .
However, aggregation multiplexer 804 also receives ATM cell traffic. Receiving ATM cell traffic at this point is nonobvious and counterintuitive because the received ATM traffic would be subject to flag insertion with flags typically employed in the packet-over-SONET standard. The use of flags with ATM traffic would be an operation that most ATM engineers would deem to be unwarranted since ATM cells, unlike packets, are always fixed in size (i.e., 53 bytes) and thus flags are ordinarily unnecessary to ascertain where an ATM cell ends.
Nevertheless, ATM traffic is received by aggregation multiplexer 804 , which outputs either the ATM cell or a packet, along with byte-stuffing information from byte-stuffing block 806 to a multiplexer 808 . In one embodiment, aggregation multiplexer 804 monitors the packets and ATM cells that are input and performs traffic management by deciding whether to output an ATM cell, a particular ATM cell with a particular class of service, a packet, or a particular packet with a particular class of service at its output. By way of example, if higher priority traffic is detected and that higher priority traffic needs additional bandwidth, aggregation multiplexer 804 may choose to output that traffic first and defer outputting other traffic that has a lower priority. This is accomplished by, for example, examining the packet header and the ATM cell headers as they are received and determine which of those has the highest relative priority for output. This lookup could be performed either at the aggregation multiplexer 804 or in advance by another logic block prior to multiplexing. Looking up the priority information of the ATM cells and packets in advance is advantageous as the transmission speed increases, since the processing power required to perform the lookup may be distributed to another processor or multiple processors. Aggregation multiplexer may then receive an input signal from the lookup logic which indicates the relative priority of the ATM cell or the packet.
Since it is not necessary to channelize the fiber optic into rigid TMD channels, aggregation multiplexer 804 has a tremendous flexibility to dynamically allocate as much or as little of the full bandwidth to a particular type of traffic. This particular implementation is particularly advantageous since the bandwidth of the entire optical fiber is available for the higher priority traffic if need be. Furthermore, there is no need to allocate bandwidth in large, discrete chunks such as in the case of TDM channels. The increase in bandwidth could be in smaller chunks (e.g., a predefined bandwidth amount with some extra to handle spikes), which more efficiently utilizes the totally bandwidth available. It is also possible to define in advance with aggregation multiplexer that certain type of traffic, or all traffic, should have a minimum guaranteed bandwidth. The aggregation multiplexer may also includes an output to provide statistical information pertaining to the different types and amount of traffic it receives and/or multiplexes through in order to allow the network operator to optimize network performance and/or alert the operator if certain bandwidth usage parameters associated with certain type of traffic or the entire channel is encountered.
One skilled in the art will realize that other traffic management schemes (including feedback or look-ahead schemes) may also implemented to ensure that the downstream link is not overflowed while the relative bandwidth allocated to different types of traffic are dynamically allocated properly to ensure that the higher priority traffic are given more bandwidth to have a higher quality of service. By way of example, aggregation multiplexer 804 may also employ any other traffic management technique to output the ATM cells and the packets, including round robin, statistical multiplexing, and the like. The output of aggregation multiplexer 804 is then multiplexed, via a multiplexer 810 , with flags from flag insert block 812 to delineate individual ATM cells and individual packets in the stream to be transmitted. The output of multiplexer 810 is then multiplexed, using a TDM multiplexer 814 , with overhead information from overhead insert block 816 . The output of multiplexer 814 is substantially as shown in FIGS. 5A and 5B .
FIG. 9 is a prior art logical illustration of how ATM-over-SONET is accomplished at the receiving end. In FIG. 9 , the stream of ATM-over-SONET information is received a demultiplexer 902 wherein the SONET overhead information is extracted using an overhead extract block 904 . The output of TDM demultiplexer 902 is a stream of ATM cells.
FIG. 10 is a prior art logical illustration of how packet-over-SONET is accomplished at the receiving end. In FIG. 10 , the packet-over-SONET information is received at a demultiplexer 1002 wherein the SONET overhead information is extracted using an overhead extract block 1004 . The output of demultiplexer 1002 is passed onto a demultiplexer 1006 , which extracts the flag information from the stream of packets using a flag extract block 1008 . The output of demultiplexer 1006 is then passed onto a demultiplexer 1012 and byte destuffing 1010 , which reverses the byte-stuffing process discussed earlier. The output of demultiplexer 1012 is then passed onto a descrambler block 1014 , which reverses the scrambling process discussed earlier. The recovered stream of packets is passed out on link 1016 of FIG. 10 .
FIG. 11 illustrates, in accordance with one embodiment of the present invention, the receiving circuit for resolving the mixed ATM/packet over SONET information into respective ATM cells and packet information. In FIG. 11 , the stream of mixed ATM/packet over SONET data is received at a demultiplexer 1102 , wherein the SONET overhead information is extracted using an overhead extract block 1104 . The output of demultiplexer 1102 is passed onto a demultiplexer 1106 , which extracts the flag information from the streams of ATM cells and packets using a flag extract block 1008 . Since the incoming stream is simply treated as a stream of packets at this point, the fact that there are 53-byte ATM “packets” in the stream of mixed ATM cells and packets is irrelevant from the perspective of demultiplexer 1106 . The output of demultiplexer 1106 is then passed to a desegregation demultiplexer 1110 . The job of desegregation demultiplexer 11 10 is to reverse the byte-stuffing process discussed earlier (using byte destuffing block 1130 ) and to discriminate ATM cells from packets and to separate the two.
The criteria by which desegregation demultiplexer 1110 discriminates ATM cells from packets vary depending on implementation. In one preferred implementation, packets are required to be larger than 53 bytes in size. Further, it is preferable that packets not be broken up into chunks less than 53 bytes in size to avoid being mistaken for an ATM cell. By way of example, the packets are required to have a minimum size of 64 bytes in one embodiment, which can be accomplished by padding smaller packets. Accordingly, this minimum size may be used as one criteria for discriminating between packets and ATM cells. In another embodiment, the ATM cells are tagged at the transmitting end with one or more special tags to identify them as ATM cells. These tags, which may be a unique pattern of bits/bytes, may then be employed as the discrimination criteria at the receiving end. In another embodiment, packets can have any size except 53 bytes (or the size that the ATM cell may have if the ATM cell is dressed up with additional information at the transmitting end). In this case, the ATM cell is preferably not broken up to avoid being mistaken for a packet, and the size may again be used as the discrimination criteria at the receiving end. In yet another embodiment, ATM cells are encapsulated in a packet-like envelope which are especially marked, thereby disguising them as simply packets so that they can be switched by switching equipment as if they are packets. This is particularly advantageous since the trend nowadays is toward packets, and more and more of the network comprises of packet switching and transmission equipment.
The output of desegregation demultiplexer 1110 are two streams: an ATM stream 1120 and a packet stream 1122 . The packet stream 1122 is then descrambled by descrambler 1124 to reverse the scrambling process discussed earlier.
As can be appreciated by those skilled in the art, the inventive aggregated ATM/packet over SONET transmission technique advantageously permits both types of traffic to be mixed and transmitted over a single channel, which is preferably the entire bandwidth of the optical fiber or may be a portion of the bandwidth of an optical fiber. This is particularly useful in view of bandwidth-increasing technologies such as dense wavelength division multiplex (DWDM), which vastly increase the bandwidth capacity of the existing fiber. For service providers, the ability to eliminate the use of two separate optical fibers for two different types of traffic is a huge cost advantage.
Furthermore, the invention accomplishes the aggregation of ATM and packet traffic without resorting to inflexible and slow-to-reallocate TDM channels. With the present invention, the relative bandwidth between ATM cells and packets can be dynamically allocated at the transmitting end. As long as the bandwidth capacity of the optical fiber is not exceeded, dynamic allocation of bandwidth between ATM cells and packets and among different classes of service/priorities associated with the ATM cells and packets can be handled locally and dynamically as the ATM cells and packets are received. Local and rapid dynamic allocation control is possible since little or no coordination is needed with the receiving end to allow the discrimination process at the receiving end to sort out ATM cells from packets. In this manner, changing the relative bandwidth to handle a sudden increase in the bandwidth demand of a given type of traffic does not involve the time delay and/or complexity associated with unallocating and reallocating TDM channels. If desired, virtual channels may be created. Unlike the TDM channels of the prior art, however, these virtual channels may be flexibly and dynamically changed in size almost instantaneously to handle an increase in a given type of traffic. The fact that local traffic management can take place on an ATM-cell-by-ATM-cell basis and a packet-by-packet basis means that the invention can accommodate almost any traffic management scheme.
FIGS. 12 and 13 show one advantageous application of the inventive aggregated ATM/packet over SONET transmission technique, which is within the switching facility. FIG. 12 shows a prior art switch architecture wherein multiple line cards 1202 , 1204 , 1206 , and 1208 are connected to a backplane bus 1210 . These line cards may receive input data from a variety of sources. The data received from one line card may be switched to another line card via the backplane bus. However, as the transmission speed increases, the backplane bus is incapable of handling the higher speeds. By way of example, at STS-192 speed, the transmission rate is 10 Gbps and to switch 64 STS-192 ports the required backplane bandwidth of 640 Gbps vastly exceeds the capability of most backplane buses. Further, most switches are designed to handle either all ATM cells or all packets. Thus, backplane bus 1210 is typically unable to handle a mixture of ATM cells and packets during switching
To resolve the speed bottleneck imposed by the prior art backplane bus approach of FIG. 11 , there are currently systems that employ optical fibers to connect the line cards to a switch card. FIG. 12 shows one such scenario wherein optical lines 1322 , 1324 , 1326 , 1328 , and 1330 are employed to connect line cards 1302 , 1304 , 1306 , 1308 , and 1310 respectively to a switch card 1340 . Since the backplane is not employed, the speed restriction of the backplane bus is not an issue, and the arrangement of FIG. 13 can handle a substantially higher transmission rate.
The present invention extends the architecture of FIG. 13 further in that the present invention permits both ATM cells and packets to be transmitted via a single optical link between each line card and the switch card 1340 . This reduces the number of optical links required if a line card is configured to handle both ATM cells and packets. Due to the simplicity of the dynamic bandwidth allocation and traffic management associated with the present invention, the implementation cost may be kept reasonable to be commercially viable. This is an important advantage since space is at a premium inside most switch cabinets or racks. Additionally, such implementation is local within the switch and is completely transparent to the outside world, which may not be ready to accept the proposed protocol as a standard. At the receiving switch card, the mixed ATM/packet over SONET stream may be resolved into ATM cells and packets in the manner discussed earlier for switching purpose (assuming that the switch card can handle both ATM cells and packets). After switching, the invention may again be employed to send the mixed ATM/packet information over a single fiber to the receiving line card. At the receiving switch card, the mixed ATM/packet over SONET stream may be resolved into ATM cells and packets in the maimer discussed earlier for transmission to the next hop.
Additionally, if switch card 1340 is only a packet-only switch, it is contemplated that the ATM cells may be disguised at the originating line card with additional information to make the ATM cells look substantially like packets and allow the packet-only switch card to handle the switching therefor. By way of example, an ATM cell may be examined to ascertain its destination port, and a packet header containing that information may be created and attached to the ATM cell to make it look like a packet heading for the same destination port. In the context of the present invention, this may be done prior to aggregating the ATM cells and packets for transmission, for example.
At the receiving line card after switching, the ATM cells may be recovered by stripping away the added information, and the recovered ATM cells may be sent by the receiving line card to its next hop. In this manner, not only can the invention allow both ATM cells and packets to be sent on the same optical fiber in a manner that facilitates a more efficient way of traffic management and dynamic bandwidth allocation, but also allows the ATM cells to be switched by a packet-only switch. This is extremely valuable in the current network environment wherein there is a trend toward a packet-dominant network and associated switching infrastructure while there is still a large installed based of ATM equipments and traffic that require support. One skilled in the art should readily recognize at this point that by so disguising the ATM, the aspect of allowing a packet-only switch to handle ATM cell switching can apply also to switch arrangements that do not employ optical links, e.g., the backplane bus-based switch arrangement of FIG. 12 .
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. By way of example, although SONET has been discussed as the preferred transport-layer protocol herein, it should be noted that the invention also extends to over transport-layer protocols such as SDH, SONET-LITE, DWDM, or the like and any other transport protocols capable of transporting variable length packets. Further, although optical fiber is discussed as the preferred physical medium, it should be noted that the invention may also apply to other physical medium such as electrically conductive media or wireless. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention. | A method for dynamically allocating bandwidth among ATM cells and packets scheduled for output from an aggregation multiplexer of a transport-layer device configured to multiplex both ATM cells and packets onto the same channel of an optical fiber. The method includes local control and relative priority lookup of incoming ATM cells and packets to support output decision. When compared to currently employed methods, the required level of coordination with the receiving circuit for dynamic bandwidth allocation is substantially lower, thereby reducing operational complexity for network operators and latency for critical data when reallocating bandwidth. | 7 |
CLAIM TO PRIORITY
This application claims priority to provisional application 60/895,104 filed on Mar. 15, 2007, the entire contents of which are incorporated herein by this reference for all purposes.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a smart monitor for fire hydrants. One embodiment of the smart monitor comprises an electronic module associated with operating nut and nut shaft. The electronic module may be an integral part of the fire hydrant design or it may be a part of an upgrade kit for upgrading existing fire hydrant installations.
BACKGROUND OF THE INVENTION
A fire hydrant, (a.k.a. fire plug, johnny pump) is an active fire protection measure. Fire hydrants provide a source of water in most urban, suburban and rural areas with municipal water service. The concept of fire plugs dates to at least the 1600s and during such era firefighters responding to a call would dig down to the water mains and hastily bore a hole to secure water to fight fires. When no longer needed, such holes were then plugged with stoppers. Thus was born the fire plug; a colloquial term still used for fire hydrants today. While U.S. Pat. No. 37,466, (issued in 1963 to Richard Stileman), concerns an early cast iron hydrant and patent U.S. Pat. No. 80,143, (issued in 1968 to Zebulon Erastus Coffin), concerns a cast iron hydrant very similar to modern fire hydrants, Birdsel Holly (U.S. Pat. No. 94,749) is often credited for inventing the cast iron fire hydrant. Such patents are incorporated by this reference for all that they disclose. Old fire hydrant designs and modern fire hydrants, such as the ones manufactured by Mueller Company, still have at least one important characteristic in common; they have not taken full advantage of the advances in electronics to provide needed monitoring and information recording/transmitting services.
First, there is a need for an electronic module that can provide information as to when a hydrant was last serviced. New hydrants normally have a one to five years warranty. Consequently, most water utilities require annual inspections and maintenance of their fire hydrants. Such inspections are generally only performed on fire hydrants that are owned by water utilities. However, there are some privately owned fire hydrants that may never be inspected after installation. In the city of Chicago, for example, there are over 30 million government owned and maintained fire hydrants. Clearly, maintaining a fire hydrant maintenance schedule can be a daunting task. What is needed is an electronic module associated with each fire hydrant that can (1) detect when it has been serviced, and/or (2) be “told” when it has been serviced (and retain such information in memory). Such a device would preferably be programmed to track time and inform the utility when it is time for it to be serviced.
Second, many fire hydrant manufacturers recommend lubricating the head mechanism and restoring the head gaskets and o-rings annually in order that the fire hydrant perform when needed. What is needed is an electronic module with sensors that can monitor such a hydrant's lubricating chamber for sufficient lubricant and notify the utility when insufficient lubricant is suspected.
Third, there is a need for an electronic module to monitor a fire hydrant for unauthorized access. To prevent casual use or misuse, modern hydrants typically require special tools to be opened. Such tools normally include a large wrench with a pentagon-shaped socket. However, such a wrench is not that difficult to fabricate for those who sometimes cause monetary loss by wasting water when they open hydrants. Such vandalism can also reduce municipal water pressure and impair firefighters' efforts to extinguish fires. Sometimes those simply seeking to play in the water remove the caps and open the valve, providing residents (especially children) a place to play and cool off in summer.
Still further, with so much development going on across the county, water utilities are noticing an increasing problem of people illegally tapping into the system. For example, the town of Oakland, Florida states that water theft from hydrants close to large construction job sites is becoming an increasing problem with larger amounts of water being stolen every month. Some unscrupulous subcontractors will illegally tap a fire hydrant to get water for cement mixing, fugitive dust control, equipment cleaning, and other construction-related uses. Additionally, others may illegally access fire hydrants to get water to fill swimming pools, wash down streets and water newly sodded lawns. All such activity is illegal, and utilities are vowing to prosecute anyone caught stealing water. One major problem with prosecuting water thief is lack of evidence as it is difficult to catch a person in the act of stealing water. What is needed is an electronic module that can notify a utility when their hydrant is accessed. Moreover, there is a need for an electronic module that can record sound and/or image data when a fire hydrant is accessed perhaps providing evidence for prosecuting those who steal water.
Fourth, there is a need for an electronic module that monitors back flow prevention valves to verify they are working properly. In most US areas, contractors who need temporary water may purchase permits to use hydrants. The permit will generally require a hydrant meter, a gate valve and sometimes a clapper valve (if not designed into the hydrant already) to prevent back-flow into the hydrant. Unfortunately, there is currently no method to detect when there has been a back flow condition due to a non existent or faulty backflow prevention element. Thus, there is a need for an electronic module that can detect and report such an event.
Fifth, in areas subject to freezing temperatures, there is a need to know the minimum temperature a hydrant has experienced and if the barrel of “dry hydrant” is truly dry. Typically in such areas, only a portion of the hydrant is above ground. The valve is located below the frost line and connected via a riser to the above-ground portion. A valve rod extends from the valve itself up through a seal at the top of the hydrant, where it can be operated with the proper wrench. This design is known as a “dry barrel” hydrant, in that the barrel, or vertical body of the hydrant, is normally dry. A drain valve underground opens when the water valve is completely closed; this allows all water to drain from the hydrant body to prevent the hydrant from freezing. However, if a hydrant is not properly drained or has not been turned off, the barrel will not be dry and freezing temperatures may damage such a hydrant. Thus, there is a need for an electronic module that can monitor the temperature of hydrant and the water level within a hydrant barrel.
Sixth, in warm areas, hydrants are used with one or more valves in the above-ground portion. Unlike cold-weather hydrants, it is possible to turn the water supply on and off to each port. This style is known as a “wet barrel” hydrant. There is a need for an electronic module that can monitor both the water level in a wet barrel hydrant as well as the water pressure inside the barrel. Additionally, there is a need for an electronic module that can monitor each port of a multiple port hydrant.
Seventh, there are several different types of hydrants in various states of operation that may be used by a water utility. Such hydrants may be painted in a color-coded manner to indicate the amount of water a hydrant is capable of providing to ad arriving firefighters in determining how much water is available and whether to call for additional resources, or locate another hydrant. In places such Ottawa, Canada, hydrant colors communicate different messages to firefighters; for example, if the inside of the hydrant is corroded so much that the interior diameter is too narrow for good pressure, it will be painted in a specific scheme to indicate to firefighters to move on to the next one. In many localities, a white or purple top indicates that the hydrant provides non-potable water. Thus, there is a need for a electronic module with a signaling device that may be user programmed to provide: (1) a visual and/or audible signal for locating a hydrant (e.g. in dark environments); (2) information as to the hydrant properties (e.g. flow rate and type of water); and (3) the operational status of the hydrant (e.g. operational, non-operational, low pressure, etc).
Preferably, the electronic module will comprise a transmitter for transmitting all or part of the above fire hydrant data to a utility provider perhaps using the utilities' existing automatic meter reading (AMR) system.
SUMMARY
Some of the objects and advantages of the invention will now be set forth in the following description, while other objects and advantages of the invention may be obvious from the description, or may be learned through practice of the invention.
Broadly speaking, a principle object of the present invention is to provide a fire hydrant with an integral smart monitor configured for monitoring and transferring information to firefighters and utility provides.
Another general object of the present invention is to provide a smart monitor configured for being associated with existing fire hydrant installations.
Still another general object of the present invention is to provide a smart fire hydrant monitor that can (1) detect when the fire hydrant has been serviced, and/or (2) be “told” when a fire hydrant has been serviced (and retain such information in memory). Such a device would preferably be programmed to track time and inform the utility when it is time for it to be serviced.
Yet another general object of the present invention is to provide a smart fire hydrant monitor comprising sensors that can monitor the hydrant's lubricating chamber for sufficient lubricant and notify a utility provider when insufficient lubricant is suspected.
Another object of the invention is to provide a smart monitor that can notify a utility when a hydrant is accessed with embodiments configured for recording sound and/or image data that may provide evidence useable for prosecuting those who steal water.
Still another general object of the present invention is to provide a smart monitor that monitors the fire hydrant for back flow.
A further general object of the present invention is to provide a smart monitor that monitors the temperature of a hydrant and the water level within a hydrant barrel.
Another general object of the present invention is to provide a smart monitor configured to monitor the water level in a “wet barrel hydrant” as well as the water pressure inside the barrel. Additionally, such a monitor may be configured to monitor each port of a multiple port hydrant.
Still another general object of the present invention is to provide a smart monitor comprising a signaling device that may be user programmed to provide: (1) a visual and/or audible signal for locating a hydrant (e.g. in dark environments); (2) information as to the hydrant properties (e.g. flow rate and type of water); and (3) the operational status of the hydrant (e.g. operational, non-operational, low pressure, etc).
Still another general object of the present invention is to provide a smart monitor comprising a transmitter for transmitting fire hydrant data to a utility provider.
Additional objects and advantages of the present invention are set forth in the detailed description herein or will be apparent to those skilled in the art upon reviewing the detailed description. Also, it should be further appreciated that modifications and variations to the specifically illustrated, referenced, and discussed steps, or features hereof may be practiced in various uses and embodiments of this invention without departing from the spirit and scope thereof, by virtue of the present reference thereto. Such variations may include, but are not limited to, substitution of equivalent steps, referenced or discussed, and the functional, operational, or positional reversal of various features, steps, parts, or the like. Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of this invention may include various combinations or configurations of presently disclosed features or elements, or their equivalents (including combinations of features or parts or configurations thereof not expressly shown in the figures or stated in the detailed description).
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the remainder of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling description of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
FIG. 1 is a side view of a prior art water hydrant;
FIG. 2 is a side view of the prior art water hydrant associated with a monitor according to one exemplary embodiment of the invention;
FIG. 3 is a top view of the hydrant depicted in FIG. 2 ;
FIG. 4 is a top perspective view of the monitor depicted in FIG. 2 ;
FIG. 5 is a side view of the monitor depicted in FIG. 4 ;
FIG. 6 is a bottom perspective view of the monitor depicted in FIG. 4 ;
FIG. 7 is a side view of one exemplary alternative embodiment of a hydrant monitor;
FIG. 8 is a top view of the hydrant monitor depicted in FIG. 7 ;
FIG. 9 is a partial exploded side view of the hydrant monitor depicted in FIG. 7 ;
FIG. 10 is a side view of the electronic insert depicted in FIG. 9 ;
FIG. 11 is a side view of the nut extension for holding an electronic insert; and
FIG. 12 is a block diagram representation of the components for one exemplary electronic module.
Repeat use of reference characters throughout the present specification and appended drawings is intended to represent the same or analogous features or elements of the present technology.
DETAILED DESCRIPTION
Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in or may be determined from the following detailed description. Repeat use of reference characters is intended to represent same or analogous features, elements or steps. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.
It should be appreciated that this document contains headings. Such headings are simply place markers used for ease of reference to assist a reader and do not form part of this document or affect its construction.
For the purposes of this document, two items are “electrically associated” by bringing them together or into relationship with each other in any number of ways. For example, methods of electrically associating two electronic items/components include: (a) a direct, indirect or inductive communication connection, and (b) a direct/indirect or inductive power connection. Additionally, while the drawings illustrate various components of the system connected by a single line, it will be appreciated that such lines represent one or more connections or cables as required for the embodiment of interest.
Referring now to FIG. 1 , one exemplary prior art water hydrant ( 10 ) is presented. Such water hydrant ( 10 ) comprises a top cap ( 14 ) mechanically associated with a barrel ( 12 ). Barrel ( 12 ) defines three access nozzles ( 13 ) configured for allowing access to the water supply associated with hydrant ( 10 ). At the top of hydrant ( 10 ) is a operating nut for “turning on” the hydrant to allow water to flow through the hydrant and out a access nozzle ( 13 ). Such technology is well known in the art.
Referring now to FIG. 2 , a side view of hydrant ( 10 ) associated with a monitor module ( 18 ) is presented. FIG. 3 shows a top view of the hydrant ( 10 ) configuration shown in FIG. 2 . Monitor Module ( 18 ) is configured to be associated with operating nut ( 16 ) and provide a module-nut ( 19 ) mechanically associated with operating nut ( 16 ) so that when one wishes to turn on/off hydrant ( 10 ), module-nut ( 19 ) is used.
Monitor Module ( 18 ) further comprises alert element ( 20 ) configured to generate a visual signal. Monitor module ( 18 ) is further configured with a transmitter (as described later) configured to generate RF signal ( 22 ).
Referring now to FIG. 4 , an elevated perspective view of monitor module ( 18 ) is presented. As noted above, monitor module ( 18 ) comprises alert element ( 20 ). As depicted in FIG. 4 , alert element ( 20 ) further comprises alert element ( 20 a ), ( 20 b ), and ( 20 c ) for generating alert signal in three different directions.
Referring now to FIG. 5 and FIG. 6 , a side view of monitor module ( 18 ) is presented. As shown in FIG. 6 , monitor module ( 18 ) comprises operating nut receiver ( 24 ) configured for receiving operating nut ( 16 ). For the present embodiment of the invention, operating nut receiver ( 24 ) is mechanically associated with operating nut ( 16 ) with one or more securing pens ( 28 ). One of ordinary skill in the art will appreciate that for such a configuration, when module nut ( 19 ) is rotated, operating nut receiver ( 24 ) is rotated thereby rotating operating nut ( 16 ).
Referring now to FIG. 7 , FIG. 8 , FIG. 9 , and FIG. 10 depicts one alternative embodiment of a monitor module. Monitor module ( 50 ) comprises a frame ( 42 ) mechanically associated with an electronic module ( 50 ).
Referring now to FIG. 11 , a side view of the operating nut extension is presented. The operating nut extension comprises a module-nut ( 19 ) at one end and a nut-receiver ( 54 ) at the opposing end. The nut extension extends through the approximate center of electronic module ( 50 ).
Block Diagram
Referring now to FIG. 12 , a block diagram representation of the various electronic components of the hydrant monitor ( 18 ) is presented. Initially it should be appreciated that FIG. 12 presents just one of a plurality of methods of electrically associating the various electronic components to achieve the features desired. For example, FIG. 12 presents the use of a common buss ( 502 ) for electrically associating the various components. It should be appreciated that embodiments where certain devices are electrically associated with each other without the use of a buss fall within the scope of the invention. In addition, various embodiments of hydrant monitor ( 10 ) ( 18 ) may include all the features presented in FIG. 12 , only a subset of subset of such features as well as features not specifically presented in FIG. 12 .
For the preferred embodiment, the functional blocks of FIG. 12 represent ASSPs (Application Specific Standard Product), Complex Programmable Logic Devices (CPLD), ASICs (application specific integrated circuit), microprocessors, or PICs. In addition, one or more functional blocks may be integrated into a single device or chip sets such as ASSP chip sets. For example, one or more of the various interfaces described below may be integrated into (or have its described functions performed by) processing device ( 500 ).
Manufactures of suitable ASSP devices include Motorola, and Texas Instruments. While most of the functions are preferably performed by ASSP chip sets, Complex Programmable Logic Devices (CPLD) may be used to interface the various ASSP blocks to system buss ( 502 ) allowing one system component to interface with another component. Manufactures of suitable CPLD devices include Lattice's (ispMACH 4000 family) and (Altera's MAX 7000-series CPLD).
For the presently preferred embodiment of the invention, processing device ( 500 ) is configured to perform various tasks including data management, data storage, data transfers, resource monitoring, and system monitoring. Processing device ( 500 ) may be a simple PIC (such as the ones manufactured by MicroChip) or a relatively more complicated processor configured for use with standard operating systems and application software. Other technologies that may be used include ASICs (application specific integrated circuit) and ASSPs (application specific standard product). Processing device ( 500 ) may comprise onboard ROM, RAM, EPROM type memories. Processing device ( 500 ) is electrically associated with buss ( 502 ).
Buss ( 502 ) is configured for providing a communication path between the various electronic devices electrically associated with buss ( 502 ). For example, Buss ( 502 ) is configured for transferring data signals between processing device ( 500 ) and other electronic devices electrically associated with buss ( 502 ). For the preferred embodiment, bus ( 502 ) also comprises electrical paths for transferring power between main power ( 504 ), EM power converter ( 501 ) and other electronic devices electrically associated with buss ( 502 ). Buss ( 502 ) my further comprise a data port and or a power port configured for supplying/receiving power or providing a communication path to electronic devices electrically associated with such port.
Memory ( 508 ) is electrically associated with buss ( 502 ) via memory controller ( 508 i ). Memory ( 508 ) may be any type of memory suitable for storing data such as flash memory, SRAM memory, hard drive memory, as well as other types of memories. Volatile memory continuously connected to a power source may be used, although, for the preferred embodiment, memory ( 508 ) is nonvolatile memory. Memory ( 508 ) may be used for storing all types of data including application programs, image data, sound data, customer information, sensor data, and warning-criteria. Memory ( 508 ) is electrically associated with processing device ( 500 ) via memory controller ( 508 i ) and buss ( 502 ).
DSP/ASSP ( 510 ) is electrically associated to processing device ( 500 ) via buss ( 502 ). DSP ( 510 ) is configured to perform signal processing tasks such as voice, audio, video, encoding, decoding as well as other data and signal processing functions.
Display ( 304 ) is configured for displaying the various hydrant monitor ( 10 ) ( 18 ) data. Display ( 304 ) is electrically associated with buss ( 502 ) and may include technology for providing a customizable touch screen controller configured for control and decoding functions for display ( 304 ). For the preferred embodiment display ( 304 ) is a LCD display. Additionally, for one embodiment, display ( 304 ) comprises a “memory” configured to provide an image when power is removed from the display. For this embodiment, an image is written on the LCD display and when power is removed, the display will retain the image virtually indefinitely. Such a LCD display uses a technique developed by Zenithal Bistable Devices (ZBD), which adds a finely ridged grating to the inner glass surface of an LCD cell of Super-Twist-Nematic (STN) construction. As is known in the art the presence of the grating “latches” the polarization state of the liquid crystals and retains it when power is removed.
Hydrant monitor ( 18 ) my further comprise a graphics accelerator that provides support for megapixel cameras and 3D graphics applications. One suitable graphics accelerator is the MQ2100 manufactured by MediaQ.
For the presently preferred embodiment, motor ( 100 ) is electrically associated with processing device ( 500 ) through motor interface ( 100 i ). Motor ( 100 ) is a small electric motor that may be used in some embodiments to make a visual element (such as a camera) move when active.
Exemplary communication circuitry is now considered. For one embodiment, relatively long range wireless communication circuitry includes RF transceiver ( 520 ) configured to transmit and receive data signals to/from a remote electronic device. It should be noted that embodiments where such communication circuitry comprises only a transmitter or only a receiver fall within the scope of the invention. For one embodiment, transceiver ( 520 ) comprises a relatively low power transmitter that transmits a data signal in an unlicensed frequency band. Other embodiments include a relatively longer range transmitter comprising any number of well known technologies for wireless communications transmitting at any legal power level. For example, transceiver ( 520 ) may be configured to communicate over GPRS, GSM, GPRS, 3G, and EDGE enabled networks as well as WAP networks.
To facilitate remote access to hydrant monitor ( 18 ), a networking system, such as a local area network (LAN) may be utilized. In this presently preferred embodiment, processing device ( 500 ) and memory ( 508 ) are configured to form a TCP/IP protocol suite and an HTTP (HyperText Transfer Protocol) server to provide two-way access to the apparatus ( 10 ) data. Such TCP/IP protocols and HTTP server technology are well known in the art. For such an embodiment, hydrant monitor ( 18 ) includes an HTTP server and a TCP/IP protocol stack. A gateway is provided that enables continuous remote access to the hydrant monitor ( 18 ).
Generally speaking, a gateway may simply be a means for connecting two already compatible systems. Alternatively, a gateway may be a means for connecting two otherwise incompatible computer systems. For such an alternative configuration, the TCP/IP protocol suite may be incorporated into a gateway serving multiple hydrant monitor ( 18 ) devices via a wired or wireless two-way network using, for example, Wireless Fidelity (Wi-Fi) technology. Such a gateway may incorporate an HTTP server for accessing data from multiple hydrant monitor ( 18 ) devices and for transmission of data to individual user interface ( 10 ) devices.
In the above described TCP/IP enabled hydrant monitor ( 18 ) system, a remote transceiver provides access to a first network operating in accordance with a predetermined protocol (TCP/IP is one example). A plurality of hydrant monitor ( 18 ) devices may comprise a second network, such as a LAN. A gateway operatively couples the first network to the second network. Finally, an HTTP server is embedded in either the gateway or the plurality of hydrant monitor ( 18 ) devices facilitating the transfer of data between the two networks. With such a configuration, one of ordinary skill in the art will appreciate that individual hydrant monitor ( 18 ) devices or groups of hydrant monitor ( 18 ) devices may be accessed as if the hydrant monitor ( 18 ) devices were a web site and their information could be displayed on a web browser.
Hydrant monitor ( 18 ) may further be configured for storing and/or generating location data ( 312 ). For embodiments that generate location data, hydrant monitor ( 18 ) includes a GPS device ( 526 ) electrically associated with processing device ( 500 ) via buss ( 502 ) and GSP Interface ( 526 i ). GPS ( 526 ) is one embodiment of a position-finder electrically associated with a processing device where GPS ( 526 ) is configured to generate position-data for the location of hydrant monitor ( 18 ). For such configurations, processing device ( 500 ) is configured to use such position-data to retrieve customer information stored in memory ( 508 ). If the customer information exists for a current position-data location, such customer information is retrieved and the user is provided an opportunity to use such data for the activity of interest. If the customer information does not exist, processing device ( 500 ) is further configured to create a new customer file with such position-data. The new position-data may be associated with customer information for further reference. Similarly, if apparatus ( 10 ) can not be located, processing device ( 500 ) is further configured to transmit a data signal using RF transceiver ( 500 ) at least one of random intervals, predefined cyclic intervals, and upon remote request.
The attributes of exemplary main power ( 504 ) are now considered. For the presently preferred embodiment, main power ( 504 ) is a long life depletable power source such as a Li Ion battery. For such embodiment, main power ( 504 ) comprises at least one long life rechargeable Li Ion battery such as the ones manufactured by A123 Systems®.
Extending the life of main power ( 504 ) or extending the time between recharging is one design concern addressed by power interface ( 504 i ). Power Interface ( 500 i ) is configured to perform power management functions for the system as well as monitor the status of main power ( 504 ) and report such status to devices electrically associated with buss ( 502 ) (such as processing device ( 500 )). Power interface ( 504 i ) dynamically addresses power management issues by selectively powering down unutilized devices. For the Preferred embodiment, power interface ( 504 i ) is a CPLD that generates chip-select signals and powers down the various ASSPs as desired. Alternatively, processing device ( 500 ) may perform such power management functions. Electronic lock ( 540 ) is electrically associated with processing device ( 500 ) through lock interface ( 540 i ) and buss ( 502 ). For this embodiment, lock interface ( 540 i ) is an ASSP or CPLD device configured to change the state of electronic lock ( 540 ) in response to control signals received from processing device ( 500 ). Similarly, lock interface ( 540 i ) may be further configured to communicate the status of electronic lock ( 540 ) to devices electrically associated with buss ( 502 ). Electronic lock ( 540 ) may be a software lock that prevents access to various functions provided by user interface ( 500 ). In addition, electronic lock ( 540 ) may further be a mechanical lock that prevents they hydrant output ports from being opened.
Imaging element ( 550 ) is electrically associated with processing device ( 500 ) through image interface ( 550 i ) and buss ( 502 ). Imaging element ( 550 ) and image interface ( 550 i ) are configured for acquiring and transferring images to electronic devices electrically associated with buss ( 502 ). For the preferred embodiment, imaging interface ( 550 i ) is configured to support CMOS image input sensors such as the one manufactured by Micron® and/or CCD (charge-coupled device) image input sensors such as the ones manufactured by ATMEL® sensors. Imaging interface ( 550 i ) performs the necessary processing functions to convert the imaging data into a desired format before transferring such data to other devices associated with buss ( 502 ).
A Low Power transceiver may be electrically associated with processing device ( 500 ) and would typically comprise a low power transmitter relative to transceiver ( 520 ). For the embodiment in FIG. 12 , the low power transceiver operates in an unlicensed band although frequencies requiring a license may be used. Suitable technologies include Bluetooth and Zigbee (IEEE 802.15). Zigbee is a low data rate solution for multi-month to multi-year battery life applications. Zigbee operates on an unlicensed, international frequency band. Such technologies are known and understood by those skilled in the art, and a detailed explanation thereof is not necessary for purposes of describing the method and system according to the present invention.
Attention now is directed to audio module ( 570 ). For the preferred embodiment, audio module ( 570 ) comprises speaker ( 572 ) and microphone ( 474 ) electrically associated with audio codex ( 576 ). Audio module ( 570 ) is configured for detecting sound waves and converting such waves into digital data of a predefined format such as MP3. Sound waves may also be generated by audio module ( 570 ) using speaker ( 572 ) to issue warnings and provide for other forms of communications. For example, audio module ( 570 ) may be used for voice communications between a person located at hydrant monitor ( 18 ) and a person located at a remote site, using, for example, VoIP for the IP enabled systems describe earlier.
EM (electromagnetic) Energy Converter ( 501 ) is associated with a portion of the outer sides of hydrant monitor ( 18 ). EM Energy Converter ( 501 ) is configured to convert electromagnetic energy (such as a radiated RF signal from a man made transmitter, sunlight, etc.) into a voltage for supplying power to system components and/or supplying energy to a power source. One well known EM Energy Converter is a photovoltaic cell.
The Biometric sensor ( 339 ) is used to keep a customer's personal information secure using biometric identification. Biometric identification refers to the automatic identification of a person based on his/her physiological or behavioral characteristics. A biometric system is essentially a pattern recognition system which makes a personal identification by determining the authenticity of a specific physiological or behavioral characteristic possessed by a user. The biometric system may include, for example, a handwriting recognition system, a voice recognition system and fingerprint recognition.
For the preferred embodiment of the invention, biometric sensor ( 339 ) is a fingerprint scanner. For such embodiment of the invention, a user initially places a finger on biometric sensor ( 339 ). The biometric sensor scans the finger and transfers a digital representation of the user's fingerprint to memory ( 508 ). Such an initial bio sample is called an enrolment sample. After an enrolment sample has been stored in memory, future hydrant monitor ( 18 ) transactions are authorized by processing device ( 500 ) using biosensor data.
While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily adapt the present technology for alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations, and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. | Disclosed is a smart monitor for monitoring fire hydrants and comprising an electronic module associated with an operating nut and nut shaft.
The electronic module is configured to monitor the fire hydrant operating nut to determine when the fire hydrant has been activated. When a hydrant is activated, the electronic module performs at least one of the following functions: stores activation time data, records sound data, records image data, turns on a signaling device, determines possible flow rate by counting the number of turns the operating nut has been turned, records elapsed time since hydrant activation, estimates consumption based on time data and possible flow rate data, transmits activation data to a remove receiver. Embodiments of the smart monitor also include a receiver configured for receiving a signal from remote transmitter for activating the signaling device. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to thrust nozzles for rocket missiles. More particularly, this invention relates to nozzles wherein the thrust vector of the exhaust gases may be altered by moving a portion of the nozzle. Still more particularly, but without limitation thereto, this invention relates to the application of insulation and a liner to the thrust nozzle.
2. Description of the Prior Art
Various techniques have been attempted in the prior art for means of steering missiles. An example of one such measure utilized in the prior art is the movement or deformation of the thrust nozzle in some manner so as to alter the direction of the exhaust gases flowing through the nozzle.
However, despite the well established reliability of this measure, there are two inherent problems with the use of movable nozzles: means to maintain a constant seal between the nozzle and the missile case; and lightweight means for mounting the nozzle so that it may be moved according to some constant relationship to the missile. The latter problem has been solved to some degree by the use of separate components such as gimbal rings for mounting a movable nozzle to a missile. Recent developments utilize a flexible bearing between the missile casing and the nozzle. In this manner, the bearing not only permits movement of the nozzle but also acts as a seal, along with eliminating a considerable amount of weight as compared to gimbal rings.
This invention utilizes the standard concepts of a flexible bearing but the inventive concept is the use of insulation and carbon-carbon at specific areas of the nozzle. The purpose of the nozzle is to convert the random heat or thermal energy released by the combustion of the propellants into directed energy of motion or mass kinetic energy of the exhaust gases. The use of lightweight insulation with a thin carbon-carbon liner provides for more efficient energy conversion.
SUMMARY OF THE INVENTION
An object of the present invention is to provide efficient energy conversion within the nozzle.
Another object of the invention is to provide an adequate gas seal between the nozzle and the missile casing.
A further object of the invention is to provide a reliable, lightweight thrust vector control nozzle for missiles.
These and other objects have been demonstrated by the present invention wherein insulation is applied to the thrust nozzle and a thin carbon-carbon liner allows exhaust gases to pass through the integral throat entry and expand within the exit cone, which may be moved to provide thrust vector control by means of two actuators.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be described in further detail with reference to the accompanying drawings wherein:
FIG. 1 is a cross-sectional view of the invention taken along the longitudinal axis.
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention includes the rocket nozzle 10 in FIG. 1. It consists of a stationary shell 12 and stationary shell insulation 14. The stationary shell 12 is preferably of forged aluminum, and stationary shell insulation 14 is carbon fiber filled ethylene propylenediene monomer (EPDM) tape which is wrapped around the shell 12 parallel to the centerline and cured in place. The shell 12 and insulation 14 interface with the motor aft port and are attached with a snap ring retention system, not shown.
The nozzle 10 further consists of a hollow divergent exit cone shell 16, preferably of forged aluminum, having exit cone insulation 18 and an exit cone liner 20. Positioned between the exit cone shell 16 and the exit cone insulation 18 is seal 22. The entrance cap 24, preferably three directional carbon-carbon, is threaded onto a throat support ring 26. The ring 26 is tape wrapped carbon/phenolic, and seal 28 is placed between the exit cone shell 16 and the ring 26. The integral throat entry 30, preferably three directional carbon-carbon, is threaded onto the exit cone liner 20, preferably carbon-carbon with seal 32 positioned between said entry 30 and liner 20.
An air gap 34, about 0.040 inches thick, is provided between the exit cone insulation 18 and the exit cone liner 20. This air gap 34 functions to allow thermal expansion of the exit cone liner 20 during operation. The exit cone insulation 18 is preferably of a low density silica/phenolic tape wrapped parallel to the centerline. The insulation 18 includes axial grooves to allow for the release of gases due to phenolic decomposition of the insulation 18 during operation.
Movement of the nozzle 10 is accomplished by means of a flexible seal configuration comprising a core 36, a forward end ring 38 and an aft end ring 40. The forward end ring insulation 42 is located adjacent to the forward end ring 38, and ozone barriers 44 and 46 are located on the external sides of the core 36. The insulation 42 is made of carbon fiber filled EPDM tape wrapped parallel to the centerline, and the ozone barriers 44 and 46 are made of a material such as chlorobutyl rubber. The core 36 is made of glass epoxy reinforcements sandwiched between rubber. Some reinforcements extend beyond the rubber to form a thermal barrier 48 which lies between the core 36 and the ozone barrier 44. The thermal barrier functions to protect the core 36 from the motor environment. A rubber insulator 50 is also located at the junction where the forward end ring insulation 42 and the core 36 meet.
The forward end ring 38 is bolted to the exit cone shell 16 by means of a plurality of bolts circumferentially positioned. Illustrative of this is bolt 52 shown in FIG. 1. Seal 54 is placed adjacent to said bolts. Similarly, the aft end ring 40 is bolted to the stationary shell 12 by means of a plurality of bolts. Illustrative of this is bolt 56 shown in FIG. 1. Seal 58 is placed adjacent to said bolts.
In operation, exhaust gases pass through the throat entry 30 and expand within the exit cone liner 20 which can be moved to provide thrust vector control. This is achieved by two actuators, not shown, one of which is operatively connected to an actuator bracket 60, which in turn is affixed to a compliance ring 62, integral with the exit cone shell 16. The second actuator is operatively connected to an actuator bracket 64 positioned 90 degrees from bracket 60, as is shown in FIG. 2, the end view of nozzle 10. Bracket 64 in turn, is affixed to the integral compliance ring 62. The point P, shown in FIG. 1, is the center of rotation for the movable nozzle when the exit cone shell 16 is moved by the actuators.
The key feature of this invention is the use of advanced materials for lightweight ablation protection and thermal insulation purposes. External insulation 66 is placed along the edge of the stationary shell 12 and insulation external 68 is placed along the edge of the exit cone shell 16. Both insulation 66 and 68 are preferably of cork. A strip of liner external insulation 70, preferably of graphite felt, is positioned along the edge of the exit cone liner 20 which extends beyond the exit cone insulation 18.
The foregoing description has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the scope of the invention should be limited solely with respect to the appended claims and equivalents. | A thrust nozzle of the hollow-cone type affixed to a stationary shell having external insulation on the nozzle and the shell and the nozzle having a liner extending beyond its edge and having insulation over the extended portion. | 5 |
[0001] This application is entitled to the benefit of, and incorporates by reference essential subject matter disclosed in PCT Application No. PCT/GB2011/001671 filed on Dec. 2, 2011, which claims priority to Great Britain Application No. 1020722.3 filed Dec. 7, 2010.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates to an accelerometer, and in particular to a microelectromechanical (MEMS) accelerometer of relatively small dimensions and low cost.
[0004] 2. Background Information
[0005] MEMS accelerometers are in widespread use, for example in automotive and other applications. One area in which they are used is in global positioning applications, to provide back-up information indicative of the movement of a vehicle for use during short intervals in which satellite communications links are temporarily interrupted. However, it will be appreciated that this is merely one possible application in which a MEMS accelerometer may be used, and that the invention is not restricted in this regard.
[0006] U.S. Pat. No. 7,047,808 describes a MEMS accelerometer suitable for use in such applications. The accelerometer comprises a proof mass of plate-like form surrounded by a ring-like support member. The support member and the proof mass are substantially coplanar, and the proof mass is connected to the support member by means of a series of mounting legs that are formed integrally with the mass and the support member. Each leg extends in a direction substantially perpendicular to a direction in which the accelerometer is sensitive to accelerations. In use, the accelerometer is mounted upon an object, the motion of which is to be monitored, the accelerometer being mounted in such a manner that the support member is rigidly secured to the object, the accelerometer being correctly orientated such that the mounting legs each extend in a direction substantially perpendicular to the sensing direction. If the object is accelerated in the sensing direction, it will be appreciated that the inertia of the proof mass will result in the proof mass moving relative to the support member, the mounting legs flexing and applying a restoring force urging the proof mass back towards its rest position.
[0007] In order to permit relative movement between the proof mass and the support member to be sensed and thereby to permit an electrical output indicative of the acceleration to be produced, the proof mass is provided with several groups of capacitor fingers, each of which extends substantially parallel to the mounting legs. Similarly, the support member is provided with several groups of capacitor fingers, the fingers of each group being interdigitated with the capacitor fingers of a corresponding group associated with the proof mass. Movement of the proof mass relative to the support member results in relative movement of adjacent ones of the interdigitated fingers. By taking appropriate capacitance measurements, the position or movement of the proof mass relative to the support member can be determined. As the movement of the proof mass relative to the support member arises in use from the object to which the accelerometer is mounted experiencing an acceleration, it will be appreciated that the movement output is also indicative of the experienced acceleration.
[0008] Other, similar devices are described in, for example, U.S. Pat. No. 7,562,573 and U.S. Pat. No. 7,267,006.
[0009] In an arrangement of this type there is a need to make drive electrical connections to the various groups of capacitor fingers provided on the support member. Thus, where the accelerometer includes, for example, four groups of capacitor fingers associated with the support member, four such connections need to be made in addition to the required ground and output connections. The provision of such connections takes up space, resulting in the accelerometer being relatively large, and there are also cost implications associated with the need to provide such connections, and additional manufacturing complexities.
[0010] It is an object of the invention to provide an accelerometer in which at least some of the disadvantages with known arrangements are overcome or are of reduced effect.
[0011] There is a desire to provide an accelerometer device that is sensitive to accelerations in two or more perpendicular directions, and it is another object of the invention to provide an accelerometer suitable for use in such a device.
SUMMARY OF THE DISCLOSURE
[0012] According to the present invention there is provided an accelerometer comprising a support, a first mass element and a second mass element, the mass elements being rigidly interconnected to form a unitary movable proof mass, the support being located at least in part between the first and second mass elements, a plurality of mounting legs supporting the mass elements for movement relative to the support, at least two groups of movable capacitor fingers provided on the first mass element and interdigitated with corresponding groups of fixed capacitor fingers associated with the support, and at least two groups of movable capacitor fingers provided on the second mass element and interdigitated with corresponding groups of fixed capacitor fingers associated with the support.
[0013] Such an arrangement has the advantage that the accelerometer is of relatively compact, space efficient form.
[0014] Conveniently, a single, shared electrical connection can be provided to permit connection to two of the groups of fixed capacitor fingers associated with the support. Likewise, a single electrical connection can be provided to permit connection to another two of the groups of fixed capacitor fingers associated with the support. As a result, manufacture can be simplified by reducing the total number of connections that are required. Consequential cost savings can be made, and additional space savings can also be achieved.
[0015] It is desirable for the accelerometer to be capable of withstanding very large accelerations without sustaining damage thereto. In order to assist with providing this functionality, the accelerometer is preferably provided with stop formations operable to limit the distance through which the mass elements are able to move. Conveniently, the stop formations are arranged to limit such movement to a degree sufficient to prevent contact between adjacent ones of the capacitor fingers.
[0016] In order to minimize disruption to the operation of the accelerometer following exposure to such a very large acceleration, preferably the stop formations are provided on a part of the support that is at the same electrical potential as the first and second mass elements. As a consequence, electrical grounding in the event of such a very large acceleration is avoided.
[0017] The mass elements and support are conveniently fabricated by etching of a silicon wafer supported, in use, between a pair of substrates, for example in the form of glass plates. The space between the mass elements and the support is conveniently sealed and gas filled so as to provide damping to movement of the proof mass.
[0018] The invention further relates to a two axis accelerometer device comprising a pair of accelerometers of the type described hereinbefore formed integrally with one another and orientated so as to be perpendicular to one another.
[0019] As the accelerometers are of relatively small size, and the number of electrical connections required is relatively low, the incorporation of two such accelerometers into a single device to provide a two axis accelerometer is relatively convenient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention will further be described, by way of example, with reference to the accompanying drawings, in which:
[0021] FIG. 1 is a diagrammatic representation of an accelerometer in accordance with one embodiment of the invention;
[0022] FIG. 2 is a perspective view illustrating an accelerometer device incorporating a pair of accelerometers of the type shown in FIG. 1 ;
[0023] FIGS. 3 and 4 are sections through parts of the device of FIG. 2 ;
[0024] FIG. 5 is a plan view illustrating the device of FIG. 2 ;
[0025] FIG. 6 is a diagrammatic view to an enlarged scale illustrating part of the device of FIG. 2 ; and
[0026] FIGS. 7 to 9 are views illustrating a modification to the arrangement of FIGS. 1 to 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring firstly to FIG. 1 , an accelerometer 10 is illustrated comprising a support 12 to which a proof mass 14 is movably mounted by means of a series of mounting legs 16 . The proof mass 14 , legs 16 and support 12 are formed integrally with one another and are substantially coplanar, for example being fabricated by appropriate etching or other processing of a silicon wafer.
[0028] The proof mass 14 is made up of a first mass element 18 , connected to the support 12 by a pair of the mounting legs 16 , and a second mass element 20 connected to the support 12 by another pair of the mounting legs 16 . A cross brace 22 interconnects the first and second mass elements 18 , 20 in such a manner as to ensure that they move together, in unison, in use and so act as a single mass.
[0029] The mounting legs 16 are all parallel to one another and extend substantially perpendicularly to a sensing direction (indicated by arrow A in FIG. 1 ) in which the proof mass 14 is movable relative to the support 12 , in use. The mounting legs 16 apply a biasing load to the proof mass 14 urging the proof mass 14 towards a central, rest position. In use, if the accelerometer 10 is subject to an acceleration in the sensing direction A, the inertia of the proof mass 14 will result in the proof mass 14 moving relative to the support 12 , such movement being accommodated by deflection of the mounting legs 16 , and taking place against the action of the restoring load applied by the resilience of the mounting legs 16 urging the proof mass 14 back towards its central position. The distance through which the proof mass 14 moves is related to the magnitude of the acceleration to which the accelerometer has been subject.
[0030] As shown, the first mass element 18 and second mass element 20 are spaced apart from one another, and the support 12 extends into the space therebetween. The brace 22 also extends across this space, and the support 12 is shaped to include a break through which the brace 22 extends so that the proof mass 14 is free to move relative to the support 12 . The support 12 thus takes the form of an upper support part 12 a and a lower support part 12 b, separated by the aforementioned break.
[0031] As shown in FIG. 6 , the first mass element 18 carries upper and lower groups 24 , 26 of movable capacitor fingers, each finger extending substantially parallel to the mounting legs 16 and so substantially perpendicular to the direction A in which the proof mass 14 is able to move. The term ‘movable’ is used to indicate that the fingers are able to move relative to the support 12 by virtue of the fact that they are provided on the proof mass which is, itself, movable relative to the support 12 , not to suggest that the individual fingers are able to move relative to the proof mass 14 . The support 12 has associated therewith a first pair of upper and lower groups 28 , 30 of fixed capacitor fingers. The fingers of the upper group 28 are interdigitated with those of the upper group 24 , and the fingers of the lower group 30 are interdigitated with those of the lower group 26 . Similarly, the second mass element 20 is provided with upper and lower groups 32 , 34 of movable capacitor fingers, interdigitated with a second pair of upper and lower groups 36 , 38 of fixed capacitor fingers associated with the support 12 . The first and second upper groups 28 , 36 are associated with the upper part 12 a of the support 12 and the first and second lower groups 30 , 38 are associated with the lower part 12 b of the support 12 . As best shown in FIG. 6 , the fingers of each interdigitated pair of groups are not equally spaced. In each case, the fixed fingers of each of the groups 28 , 30 , 36 , 38 associated with the support 12 lie closer to the adjacent moveable finger nearest the brace bar 22 than it does to the adjacent movable finger more remote from the brace bar 22 , when the proof mass 14 occupies its central, rest position. However, arrangements may be possible in which this is reversed.
[0032] As mentioned hereinbefore, the support 12 , proof mass 14 and mounting legs 16 are formed integrally with one another. As best shown in FIGS. 2 , 3 and 4 , the silicon wafer from which these components are formed is conveniently sandwiched between a pair of glass or other suitable material substrates 40 , 42 , the substrates 40 , 42 being appropriately recessed so as to result in the support 12 bearing against the substrates 40 , 42 so as to be supported thereby, whilst the mounting legs 16 and proof mass 14 are spaced therefrom by a small distance so as to ensure that the proof mass 14 is free to move in the sensing direction A in the event of the accelerometer 10 being subject to an acceleration in that direction.
[0033] The space between the substrates 40 , 42 , the proof mass 14 and the support 12 is filled with a damping medium, conveniently a gaseous damping medium, for example air, preferably at substantially atmospheric pressure. Consequently, the operation of the accelerometer will be subject to squeeze damping. By appropriate selection of the gaps between the fingers, the lengths of the fingers, etc., critical damping may be achieved if desired, which is desirable where the accelerometer is used in an open loop configuration.
[0034] The roots of the mounting legs 16 , i.e., the points at which they join the support 12 , are close to the axis of the support 12 , and so the roots of the mounting legs 16 attached to the upper part 12 a are close to one another, and the roots of the mounting legs 16 attached to the lower part 12 b are close to one another. As a consequence, stresses resulting from differential thermal expansion of the materials of the substrates 40 , 42 and the wafer from which the support 12 , proof mass 14 and mounting legs 16 are formed are minimized. This is important as the resonant frequency of the proof mass 14 is dependent, in part, upon the stressing of the mounting legs 16 .
[0035] FIGS. 2 , 3 and 4 further illustrate suitable locations whereby electrical vias or connections can be made to the capacitor fingers of each of the groups. As shown, the support 12 has two electrical connections 44 , 46 provided thereon. The connections or vias may be fabricated using a range of known techniques. One convenient technique involves powder blasting through the substrate 40 and into the material of the support 12 to form a, for example, substantially frustoconical recess, the surface of which is then metallized to provide a good electrical connection to the associated part of the support 12 . The connection 44 is provided on the upper part 12 a and provides an electrical connection to the first and second upper groups of fixed fingers 28 , 36 , and the connection 46 is provided on the lower part 12 b and provides an electrical connection to the first and second lower groups of fixed fingers 30 , 38 . It will be appreciated that as the first and second upper groups of fixed fingers 28 , 36 extend from opposite sides of the upper part 12 a of the support 12 , it is convenient to use a single, shared connection for both of these groups, and likewise it is convenient to use a single, shared connection for both of the lower groups of fixed fingers. In contrast to a typical differential capacitor accelerometer arrangement of the type described hereinbefore, it will be appreciated that the arrangement of the invention allows a reduction in the number of connections to be made. Consequently, significant space savings and size reductions can be achieved, and the manufacturing process can be significantly simplified.
[0036] In addition to the connections 44 , 46 , the accelerometer is further provided with a connection 48 whereby a drive signal can be applied to the groups of movable fingers associated with the proof mass 14 , and a ground connection 50 is also provided. These connections may be of a form similar to that described hereinbefore.
[0037] In use, if the accelerometer 10 is subject to an acceleration in the direction A resulting in an upward movement of the proof mass 14 relative to the support 12 , in the orientation shown in FIG. 1 , this will result in the spacing between the closest ones of the fingers of upper groups 24 , 28 , 32 , 36 reducing whilst the spacing between the closest ones of the fingers of the lower groups 26 , 30 , 34 , 38 will increase by an equal amount. It will be appreciated that the change in spacing of the fingers results in the capacitance therebetween also changing, and by appropriate monitoring of the differential capacitance, an output can be achieved that provides an indication of the position of the proof mass 14 relative to the support 12 . As the position occupied by the proof mass 14 is related to the magnitude of an applied acceleration, it will be appreciated that by monitoring of the capacitance, an indication of the magnitude of the applied acceleration can be output.
[0038] The manner in which the capacitance is monitored is conveniently substantially as described in U.S. Pat. No. 7,047,808, that is to say that a, for example, square wave drive voltage is preferably applied to the connection 44 and thus to the first and second upper groups 28 , 36 of fixed fingers associated with the support 12 whilst a similar, but anti-phase, square wave drive signal is applied to the connection 46 , and so to the first and second lower groups 30 , 38 of fixed fingers. By appropriate monitoring and processing of a signal derived from the groups of movable fingers mounted upon the proof mass 14 by way of the connection 48 , an output indicative of the applied acceleration can be achieved. The output may be derived either using an open loop type configuration or in a closed loop manner. As the manner by which the capacitance is monitored is largely in accordance with known techniques, for example as described in U.S. Pat. No. 7,047,808, it will not be described herein in further detail. It should be noted that the manner in which the differential capacitance is monitored need not be as outlined hereinbefore. For example, rather than apply antiphase inputs to the connections 44 , 46 and use the connection 48 to provide an output, an input signal could be applied to the connection 48 and the differential outputs at the connections 44 , 46 monitored to derive an output signal. Furthermore, although reference is made to the use of square wave signals, the invention is not restricted in this regard.
[0039] As shown in FIGS. 2 and 5 , the accelerometer 10 conveniently forms part of a larger accelerometer device 52 made up of two accelerometers 10 located adjacent one another and orientated such that the sensing directions A thereof are perpendicular to one another. If desired, the substrates 40 , 42 may be common to both accelerometers 10 . An accelerometer device 52 of this form allows accelerations in two perpendicular directions or axes to be monitored. As each individual accelerometer 10 is of relatively compact form and requires only a reduced number of electrical connections to be made, the accelerometer device 52 can also be of relatively compact and simply form.
[0040] The accelerometer 10 and device 52 may take a range of forms. It is envisaged that the device 52 may be of dimensions approximately 2.1 mm×4.2 mm. In such an arrangement, the silicon wafer from which the support 12 , mounting legs 16 and proof mass 14 are formed is conveniently of thickness approximately 150 μm, the mounting legs 16 may be of width approximately 7-8 μm, and so having an aspect ratio in the region of 20:1, the fingers being of length approximately 0.7 mm and width approximately 6 μm, with a finger spacing of 9-15 μm, and with each group of fingers including 18 fingers. In such an arrangement, the brace 22 may be of length approximately 0.85 mm and width 50 μm. It will be appreciated, however, that these dimensions are merely examples and that a wide range of other arrangements are possible.
[0041] It is desirable for the accelerometer 10 to be able to withstand significant accelerations without sustaining damage thereto. In the arrangement described hereinbefore, a very large acceleration in the sensing direction A would result in an end part of each of the first and second mass elements 18 , 20 butting against an adjacent part of the support 12 . Such contact would occur before contact is made between adjacent ones of the interdigitated fingers, and so the risk of damage thereto, or stiction between the fingers occurring is low. However, engagement between the parts of the proof mass 14 and the support 12 may result in electrical conduction therebetween, temporarily shorting the proof mass 14 to ground and so resulting in a temporary loss of output or reduction in output accuracy. Whilst, in some applications, such short-term, temporary shorting may not be problematic, there may be circumstances in which it would be desirable to avoid such shorting. FIGS. 7 to 9 illustrate a modification to the arrangement described hereinbefore in which such shorting can be avoided.
[0042] As shown in FIGS. 7 to 9 , the support 12 is provided with fixed stop members 54 which extend adjacent to, but spaced apart from, the mounting legs 16 , and which are non-movably fixed to the substrates 40 , 42 . The stop members 54 are electrically connected to, and so are constantly at substantially the same potential as, the various component parts of the proof mass 14 , and are shaped at their free ends to include abutment parts 56 arranged to abut or engage the end parts of the first and second mass elements 16 , 18 in the event that the proof mass 14 moves to a predetermined limit position, preventing further movement of the proof mass 14 . As the stop members 54 are held at the same potential as the proof mass 14 , it will be appreciated that such contact does not result in shorting of the proof mass 14 to ground.
[0043] In case the fingers do come into contact with one another, the fingers, as shown in FIG. 7 , may be provided with small pips 58 which are aligned in such a manner that the contact will be between the pips 58 of adjacent fingers, rather than substantially the entire surfaces thereof, and so further reduce the risk of stiction.
[0044] FIGS. 7 , 8 and 9 clearly shows which parts of the silicon wafer from which the support 12 , mounting legs 16 and proof mass 14 are formed are anodically bonded to the substrates 40 , 42 , and which parts are spaced therefrom by a small distance, arising from the formation of shallow recesses in the substrates 40 , 42 , and so are free to move relative thereto. Specifically, FIG. 7 shows that the support 12 and stop members 54 are bonded to the underlying substrate 40 , whilst the proof mass 14 and mounting legs 16 are free to move relative thereto, other than the very end part of each mounting leg 16 most remote from the associated mass element. It further shows that the support 12 is broken by the entire thickness of the relevant part of the wafer being etched away with the result that the upper and lower groups of fixed fingers are electrically isolated from one another. Although these features are shown most clearly in FIGS. 7 to 9 , it will be appreciated that the arrangement of FIGS. 1 to 6 is very similar in this regard.
[0045] Whilst specific embodiments of the invention are described herein, it will be appreciated that a wide range of modifications and alterations may be made to the arrangements described and illustrated without departing from the scope of the invention. | An accelerometer comprises a support, a first mass element and a second mass element, the mass elements being rigidly interconnected to form a unitary movable proof mass, the support being located at least in part between the first and second mass elements, a plurality of mounting legs securing the mass elements to the support member, at least two groups of movable capacitor fingers provided on the first mass element and interdigitated with corresponding groups of fixed capacitor fingers associated with the support, and at least two groups of movable capacitor fmgers provided on the second mass element and interdigitated with corresponding groups of fixed capacitor fingers associated with the support. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to compositions and methods for the surface treatment or coating of substrates. In particular, the invention relates to treatment of substrates to prevent migration to the surface of the substrate of water soluble substances, to confer resistance to water, and resistance to alkaline hydrolysis on the coating.
[0003] 2. Description of the Prior Art
[0004] Compositions used for the surface treatment of materials such as metals, paper, glass, wood or building materials can be aqueous or based on organic solvents.
[0005] Aqueous surface treatment formulations have practical and ecological advantages over organic formulations, but prior aqueous formulations have not adequately prevented migration of water-soluble coloring substances to the surface of the substrates. On contact with an aqueous formulation, any water-soluble substances in the substrate dissolve and rise to the surface.
[0006] The application of a solvent system resolves the various problems; with a system comprising water, the formulator has to select all the constituents (the binder(s), the pigmentation, the additives and the solvents) from the perspective of optimizing the isolating capability of the coating. However, there are certain disadvantages to solvent systems such as the ease of application, the open time, the appearance, the gloss, or the adhesion.
[0007] Some species of wood, in particular tropical species, are rich in water-soluble coloring substances known as tannins. When these untreated woods are coated with an aqueous system, such as a latex paint, the tannins are extracted from the substrate and migrate to the surface, which they color in an unsightly way. The coloring is apparent through the successive layers unless an isolating layer blocks the ascent of the coloring substance. Some coloring substances, soluble in water at basic pH, have an anionic nature. One strategy for immobilizing them has been to render them insoluble by precipitation on insoluble cationic resins.
[0008] U.S. Pat. No. 3,494,878 discloses blocking tannins and flash rusting by the combination of a film-forming latex and of an insoluble cationic or anionic resin.
[0009] PCT publication WO 94/29393 discloses the blocking properties of a non-film-forming cationic resin used in combination with a compatible film-forming aqueous dispersion to formulate an aqueous correction fluid.
[0010] European patent application EP-A-322,188 also discloses improving resistance to water and blocking tannins by incorporation of anionic surfactants in an aqueous dispersion of a non-film-forming and insoluble polymer functionalized by a weak base. It is noteworthy that the weakly basic resin loses its blocking effectiveness when it is film-forming according to U.S. Pat. No. 3,494,878, which discloses that some types of tannins escape the blocking capability of the cationic resin, which an anionic resin would be more efficient in immobilizing.
[0011] A combination of cationic and anionic functionalities offers a broader range of blocking effectiveness as disclosed by European patent application EP-A-837 110, wherein a cationic ion-exchange resin, e.g., a divinylbenzene-styrene copolymer carrying a quaternary ammonium, combined, as in U.S. Pat. No. 3,494,878, with a polymer in emulsion, is activated by a water-soluble anionic polymer.
[0012] U.S. Pat. No. 5,141,784 discloses a treatment of a wood rich in tannins by application of enough carboxylic acid salt and/or of a water-soluble polymer functionalized by quaternizable amino groups and with a molecular weight of 50 to 300,000.
[0013] U.S. Pat. No. 5,051,283 discloses an aqueous coating which comprises an alkaline salt of a mono- or di-carboxylic acid and a water-soluble polymer carrying quaternizable amino groups and with a molecular weight of 50 to 300,000.
[0014] U.S. Pat. No. 4,075,394 discloses the treatment of a wood rich in tannins with a polyaziridine.
[0015] It is known that functionalization of dispersions of addition polymers based on vinyl or ethylenically unsaturated monomers with amino monomers, which are optionally quaternized for coating. European patent application EP-A-290 777 and U.S. Pat. No. 4,760,110 disclose the production of amphoteric latices by a two-stage process.
[0016] United States patent U.S. Pat. No. 3,404,114 disclosed a sequential process for introducing an aminoacrylate, e.g., t-butylaminoethyl methacrylate (TBAEMA), into a functionalized latex by introduction in the second stage after neutralization to produce a stable latex.
[0017] European patent application EP-A-587 333 discloses a latex which comprises an insoluble polymer functionalized with tertiary amine grafted to a water-soluble polymer functionalized with acid wherein the latex is stable and is formulated as a semitransparent stain which is resistant to water and which exhibits a good open time. The blocking of water-soluble substances, however, is not claimed in said European patent application.
[0018] The presence of amino functional groups does not, ipso facto, confer effectiveness in blocking tannins and other blemishes because the formulation plays a determining role, specifically the formulation pH, the choice of neutralizing agent, the presence of zinc oxide, of zirconium salts, or of zinc salts contribute to the formation of effective complexes. According to European patent application EP-A-407 085, it is possible to block tannins equivalent to that of an alkyd primer in the solvent phase by formulating a functionalized latex which is cationic at acidic to neutral pH with an aminosilane dispersant.
[0019] European patent application EP-A-622,427 and U.S. Pat. No. 5,527,619 disclose a combination of an acid-functionalized polymer with an aminosilane which confers excellent properties of blocking tannins and various blemishes.
[0020] European patent application EP-A-192,077 discloses the formulation of a primer based on a dispersion comprising a water-soluble polymer amine-zinc complex. The primer in question effectively blocks wood tannins.
[0021] United States patent U.S. Pat. No. 5,681,880 discloses replacement of aforementioned zinc complexes by water-soluble zirconium complexes.
[0022] The same problem of migration is posed in the renovation of walls contaminated by a yellowish deposit left by cigarette smoke (nicotine), by the soot which migrates through the wall of the chimney or by the damp patches resulting from a water leakage or an absence of imperviousness of the building.
[0023] When an aqueous system is applied to untreated steel, rust stains appear virtually instantaneously at the surface. The phenomenon is known as flash rusting.
[0024] The prior state of the art relating to resistance to alkaline hydrolysis may be described as follows:
[0025] International application PCT WO-98/02491 discloses the synthesis of a polymer dispersion in the presence of a polyester seed which results in films exhibiting good resistance to alkaline hydrolysis but mediocre resistance to water.
[0026] International application PCT WO-95/01228 claims the use of a fatty alcohol (meth)acrylic ester which makes it possible to enhance the resistance to hydrolysis in an alkaline medium of dispersions synthesized on the basis of styrene-acrylic acid copolymers, the difficulty with such a system being that of optimizing the resistance to alkalis, the stability of the latex, and the like.
[0027] European patent application EP-A-478,193 discloses the synthesis and the use of a core-shell latex exhibiting a core which is insoluble in acidic medium and a quaternizable shell based on the use of dimethylaminoethyl methacrylate (DMAEMA), such that the core and shell are bonded chemically by use of a multifunctional monomer.
[0028] EP 0644205 Al discloses a process for producing a latex with a very fine particle size (less than 100 nm and preferably of between 5 and 40 nm), exhibiting rather low solid levels of the order of 25%, and its use in various fields related to coatings (wood preservation, water-repellent finishing product, product for the paper industry, and the like). Said patent is based essentially on the fine size of the particles of the latices, the applicative part being essentially exemplified in terms of penetration into wood and of textile treatment.
[0029] The painting of a new building or a building to be restored often requires the application of a base coat or of a primer which makes possible the attachment of the paint to the support, the requirements being different according to the circumstances, as, in the case of a renovation, the faces are crumbly and chalking, in contrast to a recent construction, where the supports are healthy.
[0030] Buildings are furthermore composed of supports of highly varied natures, such as cement, concrete, plaster or wood, and therefore require “universal or multibase” solvent- or aqueous-phase base coats.
[0031] The products used in this field are still mainly solvent-based, as is the case with Impriderme, which constitutes a problem in terms of emission of volatile organic compounds and in terms of smell. Other aqueous-phase products exhibiting extremely fine particle sizes are now proposed, but these products have the disadvantage of exhibiting only very low concentrations.
[0032] The Rhodopas Ultrafine products, such as Ultrafine PR 3500, manufactured and sold by Rhodia, have advantages in terms of particle size, of penetration and of rheology. For this reason, they are applied in the fields of the consolidation of chalking faces or of the blocking of the penetration of salts.
[0033] To our knowledge, the patent literature and the technical reviews relating to the formulations of isolating coatings do not disclose a technology which employs these polymers based on imidized maleic anhydride, such as imidized styrene-maleic anhydride (iSMA) copolymers:
[0034] U.S. Pat. No. 3,444,151 discloses the synthesis of iSMAs and their use in emulsion polymerization for the purpose of latex synthesis, is known. In this known emulsion polymerization, the iSMA is used in a proportion of 2 to 20% by weight with respect to the monomers, which is in fact insufficient for the production of latices which are correctly stabilized in the absence of a conventional surface-active agent; the examples of U.S. Pat. No. 3,444,151 are all based on the joint use of a conventional surfactant and the applications of the aqueous dispersions obtained in the presence of iSMA are only mentioned in a general way in this United States patent; and the use of latices synthesized on an iSMA base in a field other than those of the present invention, namely in the sizing of paper, is also known from the French patent application filed under No. 99/07910.
SUMMARY OF THE INVENTION
[0035] The invention relates to the field of the surface treatment of various materials, e.g., wood, metals, paper, glass, building materials, textile and leather, and to ink and varnish compositions, in particular to the surface treatment of wood and steel and more particularly to the isolating and protective coating which prevents the migration of water-soluble compounds present at the surface and within the material toward the surface of the coating.
[0036] The present invention also relates to another important aspect in the fields of coatings in general and in the field of painting in particular but also in other fields, such as those of inks and varnishes, leather or even textiles, namely the achievement of maximum resistance to alkaline hydrolysis, in order to limit the deterioration in the coating under the action of alkaline cleaning solutions, for example, or under the action of an alkaline substrate, such as concrete, for example.
[0037] The present invention also relates to the field of the treatment of surfaces, particularly to the reinforcing treatment of surfaces of porous substrates.
[0038] We have discovered that the migration of water-soluble substances can be prevented in a much simpler way than in the prior state of the art and with success by a surface treatment or a coating formulated with a polymer based on imidized maleic anhydride. The imidized polymer can also be formulated in combination with an aqueous polymer dispersion or with an aqueous dispersion based on olefinic or vinyl monomers polymerized under radical conditions in its presence, the imidized polymer acting as polymer surfactant, and/or of a combination of the two, it being possible for said imidized polymer advantageously to be used as dispersant at acidic pH of pigments, when the presence of the latter is envisaged or necessary. A good isolating capability is then obtained without employing specific additives and active pigments, and the applicative properties are satisfactory.
[0039] We have discovered that the aqueous dispersions based on olefinic or vinyl monomers polymerized under radical conditions in the presence of said imidized polymer acting as polymer surfactant, which are used alone or in formulation, result in coatings resistant to alkaline hydrolysis which can be used in the field of paint (in particular coatings for concrete), inks and varnishes, textiles and leather, as will also be expanded upon below.
[0040] A first subject matter of the present invention is therefore the use, in compositions for the surface treatment or coating of substrates and in ink and varnish compositions, of at least one polymer based on imidized maleic anhydride as agent which inhibits the migration toward the surface of water-soluble substances present in and on the substrate and/or which confers resistance to water and to alkaline hydrolysis on the coating.
[0041] In accordance with a first embodiment of the present invention, the polymer based on imidized maleic anhydride is applied after having been placed in aqueous solution and then neutralized with an acid in order to give a cationic polymer, said acid being a volatile weak acid, such as, for example, acetic acid or formic acid.
[0042] The aqueous solution of said cationic polymer can be applied as such, in particular as primer; it can also be applied in combination with at least one other constituent compatible with said cationic polymer. This or these other constituents can be chosen from latices, aqueous film-forming dispersions, pigments, cosolvents and the other normal additives of compositions for the surface treatment and coating of substrates, the copolymer based on imidized maleic anhydride also participating as dispersant in the preparation of these compositions. The term “compatibility” is understood to mean that the mixture is stable (no flocculation).
[0043] In particular, the aqueous solution of the cationic copolymer can be formulated in combination with an acrylic, vinyl or styrene-acrylic film-forming dispersion in order to form in particular a primer. It can also participate as dispersant in the preparation of pigment pastes in an acidic medium, it being possible for said pigment paste in particular to be incorporated in a paint or varnish composition.
[0044] In accordance with a second embodiment of the present invention, the copolymer based on imidized maleic anhydride is applied after having been used as polymer surfactant in the preparation of a latex, in particular as sole polymer surfactant.
[0045] The latex, in the preparation of which the polymer based on imidized maleic anhydride has been used as surfactant, can be applied as such or can be applied in combination with at least one other constituent compatible with said latex (the “compatibility” was defined above). This or these other constituents can be chosen from other latices, pigments, cosolvents and the other normal additives of compositions for the surface treatment and coating of substrates.
[0046] In particular, the resulting composition can be a paint composition, the latex, in the preparation of which the polymer based on imidized maleic anhydride has been used as surfactant, being incorporated as sole binder or as one of the binders in said paint or varnish composition. A pigment paste, prepared in an acidic medium with an aqueous cationic polymer solution as defined according to the invention, can advantageously be incorporated in said paint or varnish composition.
[0047] The polymer based on imidized maleic anhydride employed according to the present invention is a polymer which has been obtained by reaction of a diamine and of a polymer based on maleic anhydride, the diamine having in particular reacted completely with the anhydride functional group with a molar ratio of 1 to 1, said polymer having in particular a number- average molecular mass of 500 to 20 000, in particular of 2 000 to 5 000. This molar ratio of 1 to 1 should not, however, be regarded as limiting.
[0048] The synthesis of the polymers based on imidized maleic anhydride used according to the present invention is by reaction between the base polymer and a primary tertiary diamine, for example dimethylpropylenediamine (DMAPA), preferably by a bulk process. The primary amine functional group reacts with the anhydride functional group to form an amic acid and then the ring recloses to form the imide derivative.
[0049] The imidized polymers of use according to the present invention are preferably those in which the diamine reacts with the anhydride functional group with a molar ratio of preferably about 1 to 1. Imidized polymers exhibiting residual anhydride or acid functional groups are suitable but less preferred.
[0050] The polymer based on maleic anhydride according to the invention is advantageously a copolymer or terpolymer composed of maleic anhydride and of hydrophobic monomers chosen from ?-olefins, unsaturated ethylenic aromatic monomers, vinyl ethers and allyl ethers. A preferred polymer based on maleic anhydride is a copolymer based on styrene and on maleic anhydride with a styrene/maleic anhydride molar ratio of 1/1 to 6/1, in particular of 2/1 to 4/1; and with in particular an acid number of 500 to 200 KOH/g. Examples are the copolymers sold by “Atofina” under the names SMA 1000, SMA 2000, SMA 3000, SMA EF30, SMA EF40 and SMA EF60.
[0051] The present invention is also relates to a primer for the surface treatment of a substrate consisting of or comprising an aqueous solution of a polymer based on imidized maleic anhydride as defined above, said polymer having been neutralized with an acid in order to exhibit a cationic nature.
[0052] The aqueous solution can exhibit a solids content of 10 to 40% by weight.
[0053] The invention also relates to a composition for the surface treatment or coating of a substrate, characterized in that it consists of or in that it comprises an aqueous solution of a polymer based on imidized maleic anhydride as defined above, said polymer having been neutralized with an acid in order to exhibit a cationic nature, in combination with at least one other constituent chosen from latices, pigments, cosolvents and the normal additives, said aqueous solution also acting as dispersant.
[0054] The invention also relates to a pigment paste comprising, as dispersant at an acidic pH, an aqueous solution of a polymer based on imidized maleic anhydride as defined above, said polymer having been neutralized with an acid in order to exhibit a cationic nature.
[0055] In particular, the pigment paste can consist, per 100 parts by weight, of 20 to 90 parts by weight of pigments; 10 to 80 parts by weight of water; 0.5 to 5 parts by weight of an acid; and 0.05 to 50 parts by weight of the aqueous solution as defined above.
[0056] The invention also relates to a composition for the surface treatment or coating of a substrate, characterized in that it consists of or that it comprises a latex which has been synthesized by emulsion polymerization of monomers possessing ethylenic unsaturation in an aqueous solution comprising more than 20% by weight, in particular more than 20% to 30% by weight, with respect to the monomers of the polymer based on imidized maleic anhydride as defined above, said polymer having been neutralized with an acid in order to exhibit a cationic nature, said cationic imidized polymer being used as surface-active agent, in particular as surface-active agent, in the presence of a conventional radical initiating system.
[0057] The invention thus relates mainly to the use of imidized SMA in the surface treatment of various materials and in the formulation of an aqueous coating, in combination, if appropriate, with a latex synthe-sized in a conventional fashion or in the presence of imidized SMA and, if necessary, depending on the nature of the desired coating (pigmented or transparent coating), with various additives used conventionally in the formulation of paints and varnishes, including in particular the active pigments or additives generally used to reinforce the targeted protective and isolating effect.
DETAILED DESCRIPTION
[0058] The radical initiator may be a water-soluble initiator, such as ammonium persulfate, potassium persulfate or sodium persulfate, optionally in combination with a reducing agent of sodium metabisulfite type, or alternatively a hydrogen peroxide or a hydroperoxide, such as tert-butyl hydroperoxide, in combination with a reducing agent, such as ascorbic acid or sodium formaldehyde sulfoxylate. This initiator may also be soluble in organic solvents, such as azo derivatives, for example azobisisobutyronitrile, or organic peroxides.
[0059] The polymerization temperature is between 30° C. and 100° C., preferably between 60° C. and 90° C., and is appropriate to the initiating system used.
[0060] The monomers are chosen in particular so as to obtain the desired glass transition temperature (Tg) but also the desired polarity, the desired functionality or the desired degree of crosslinking. This Tg can be between −25° C. and 100° C., preferably between 0° C. and 50° C.
[0061] The monomers are generally chosen from (meth)acrylic esters, such as alkyl (meth)acrylates of formula:
[0062] in which R 1 represents H or —CH 3 ; and R 2 represents a C 1 -C 22 hydrocarbonaceous group or a —(CH 2 ) n —C n′ ,F 2n′ group with n=1 to 4 and n′=1 to 14; vinyl acetate; styrene; versatic esters; (meth)acrylic acid; acrylamide; ethylene glycol dimethacrylate. Mention may be made, as examples of (meth)acrylates, of: methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate or methyl methacrylate.
[0063] The latex of the invention has in particular a solids content of 20 to 50%, preferably of 40 to 50%, and a particle size of between 50 and 300 nm, with an average particle size preferably of less than 100 nm.
[0064] The composition can also comprise at least one other constituent chosen from other latices, dispersants, for example an aqueous solution as defined above, a pigment paste, for example as defined above, cosolvents and the normal additives.
[0065] In addition, it should be noted that imidized SMA has proved to be an excellent dispersant of pigments in an acidic medium, resulting in pigment pastes exhibiting good stability and low viscosity, which can therefore be incorporated, in particular, in paint formulations at acidic pH, characterized by an improved isolating capability and an improved resistance to water.
[0066] Depending on its composition and its formulation, the coating is suitable for the covering of inorganic substrates (masonry, walls to be renovated, and the like), organic substrates (wood, paper, leather, and the like) and metal substrates and is characterized by the ability to block the ascent of water-soluble entities, in particular those, such as nicotine, wood tannins or metal salts, which lead to coloring of the surface of the film.
[0067] When applied to metal, the coating according to the invention does not give rise to the phenomenon of flash rusting and makes it possible to obtain protection against corrosion superior to that achievable with a formulation based on a conventional latex.
[0068] According to a preferred process, the imidized SMA can finally be used for the purpose of the synthesis of an aqueous dispersion of acrylic, vinyl or styrene-acrylic polymer in the absence of any conventional surfactant; which makes it possible to also obtain a cationic latex resulting in a coating exhibiting good film-forming properties, a good isolating capability, good resistance to alkaline hydrolysis, in comparison in particular with a latex obtained on an SMA base, and resistance to water which is further improved because of the absence of conventional surfactant.
[0069] This latex can very obviously be formulated and can in particular be combined with the imidized SMA used in that case as pigment dispersant of the formulation, to result in an excellent compromise in properties.
[0070] The imidized SMA, according to the various forms of the invention, is characterized by a good isolating and protective capability, good resistance to water and good resistance to alkaline hydrolysis, without it being necessary to resort to specific active con- stituents, although it is possible to reinforce these effects by the addition of the latter.
EXAMPLES
[0071] The following examples illustrate the present invention without, however, limiting the scope thereof. In these examples, the percentages are by weight, unless otherwise indicated, and the following abbreviations were used:
SMA copolymer: styrene/maleic anhydride copolymer iSMA copolymer: imidized styrene/maleic anhydride copolymer DMAPA: dimethylaminopropylamine Sty: styrene MA: maleic anhydride [Mw]: weight-average molecular mass
Examples 1 to 4
[0072] Synthesis of the iSMA Copolymers Nos. 1 to 4 from the SMA Copolymers Nos. 1 to 4 Respectively
[0073] The starting SMA copolymers Nos. 1 to 4 are those available commercially from “Atofina” under the names SMA EF40, SMA 1000, SMA 2000 and SMA 3000 respectively.
[0074] The characteristics of the starting SMA copolymers No. 1 to No. 4 are quoted in table 1 below.
[0075] General Procedure
[0076] The DMAPA and then the SMA copolymer are first of all introduced at ambient temperature, in the amounts shown in table 1, into an electrically heated two liter reactor equipped with a stirring device suitable for viscous media. The reaction mixture is then heated to 150° C. before starting the stirring and then it is brought to 200° C. From this point, the reaction mixture is held under stationary reaction conditions for 75 minutes, before extrusion of the ISMA via the bottom valve of the reactor into a bath of liquid nitrogen.
[0077] The iSMA obtained is subsequently milled. Powdered iSMA copolymers Nos. 1 to 4 respectively are thus obtained, the characteristics of which are also quoted in table 1.
TABLE 1 Example 1 2 3 4 Characteristics of the starting SMA % by mass Sty 79.8 56.5 67.9 76.1 % by mass of MA 20.2 48.5 32.1 23.9 3 000 3 000 3 000 3 000 Amount of SMA (g) 830 690 760 800 Amount of DMAPA (g) 170 310 240 200 Characteristics of the IsmA obtained Acid number (mg KOH/g) 7.5 7 2.6 10.6 Level of residual DMAPA 600 600 600 6 000 (ppm) Tg (° C.) 112 82 82 91
Example 5
Dissolution of the Imidized iSMA Copolymer No. 1
[0078] 171 g of the ISMA No. 1, 644 g of water and 39 g of glacial acetic acid are introduced into a three-necked glass reactor with a capacity of one liter equipped with a central stirrer, a condenser, a temperature probe and a device for introducing acetic acid. The combined reactants are heated to 60° C. and are kept stirred until the oligomer has completely dissolved.
[0079] The aqueous solution obtained exhibits a concentration of iSMA No. 1 of approximately 20%.
Example 6
Synthesis of a Latex on an iSMA Base (Latex L iSMA No. 1 )
[0080] 642 g of the aqueous solution obtained in example 5, comprising 20% of iSMA oligomer No. 1, are introduced into a jacketed glass reactor with a capacity of 1 liter equipped with a central stirrer, a condenser, a temperature probe and a device for continuously introducing an initiator solution and a mixture or a preemulsion of monomers, and the reaction medium is brought to 85° C.
[0081] Furthermore, an initiator solution is prepared by dissolution of 3 g of ammonium persulfate in 60 g of demineralized water, and a mixture of monomers is prepared composed of 138 g of styrene and 162 g of butyl acrylate.
[0082] When the reaction medium is at 85° C., the initiator solution and the mixture of monomers are fed in over a period of 2 hours, with stirring and while maintaining the temperature at 85° C.
[0083] The reaction medium is then kept stirred for an additional two hours at 85° C., then cooled to ambient temperature, filtered through a 100 μm cloth and drained to result in a dispersion of particles (Latex L iSMA No. 1 ) which exhibits the characteristics reported in table 2.
Example 7 (Comparative)
Synthesis of a Latex on an SMA Base (Comparative Latex L SMA )
[0084] 932.64 q of ammoniacal SMA 2000H solution with a content of 19.3% are introduced into a glass reactor with a capacity of 3 liters equipped with a mechanical stirrer, followed by the addition of 267.36 g of demineralized water, and the mixture is brought to 85° C. with stirring. The SMA 2000H copolymer is a copolymer sold by “Atofina” which is a conventional nonimidized SMA neutralized with ammonia in aqueous solution.
[0085] Furthermore, an aqueous ammonium persulfate solution is prepared by dissolving 10.8 g of ammonium persulfate in 150 g of demineralized water.
[0086] The mixture of monomers, which is composed of 276 g of styrene and of 324 g of butyl acrylate, is also prepared.
[0087] When the reaction medium reaches 85° C., the feeding of the initiator solution and of the mixture of monomers is begun in parallel, the introduction taking place over 2 hours.
[0088] After the two materials have finished being run in, the reaction medium is maintained for an additional 2 hours at 85° C. Cooling is then carried out to ambient temperature, the reactor is emptied and filtration is carried out through a 100 micrometer cloth.
[0089] The latex obtained L SMA exhibits the characteristics shown in table 2 below:
TABLE 2 Latex L 1SMA No. 1 L SMA Solids content (%) 41 39.3 Viscosity, measured using a 35 7800 Brookfield apparatus at 25° C. (mPa · s) PH 4 8.3 Average diameter of the particles 95 126 (nm) Tg (° C.) 25 25
Example 8 (Invention) and 9 to 13 (Comparative)
Use of the iSMA Copolymer No. 1 and of Comparative Copolymers as Dispersants
[0090] Six pigment pastes having the following composition:
Water 50.0 g Dispersant 0.4 g Acetic acid 2.5 g Titanium dioxide 125 g Barium sulfate 125.0 g
[0091] were prepared while varying, on each occasion, the nature of the dispersant as shown in table 3.
[0092] The pigment pastes were prepared with stirring and at acidic pH and their quality was assessed by an evaluation of the viscosity, the desired object being a low viscosity.
[0093] The results are reported in table 3.
TABLE 3 Pigment paste 8 of (Inven- 9 (1) 10 (2) 11 (3) 12 (4) 13 (5) example tion) (Comp.) (Comp.) (Comp.) (Comp.) (Comp.) Disper- Solution Dow Surfynol Noramox Noramox Coatex sant of Corning 104 E C5 SD 15 P50 iSMA Z6020 No. 1 Vis- low high high High High high cosity of the paste
[0094] [0094] (1) Dow Corning Z6020: Polysiloxane, sold by “Dow Corning” (2) Surfynol 104 E: Tetramethyl-5-decyne-4,7-diol, sold by “Air Products” (3) Noramox C5: Polyoxyethylene cocoamine, sold by “Ceca” (4) Noramox SD 15: Polyoxyethylene tallow amine, sold by “Ceca” (5) Coatex P50: Polycarbonate, sold by “Coatex”
Example 14
Paint Formulation with a Solution of iSMA No. 1 as Dispersant and a Latex L iSMA No. 1 as Binder
[0095] A paint composition was prepared formulated as follows:
Formulation parts by weight Pigment paste Water 84.5 Biocide 2.0 Solution of 1SMA No. 1 1.0 as dispersant 20% Acetic acid 2.5 Titanium dioxide 132.0 Silica 218 222.0 Antifoaming agent (Byk 023) 1.5 Binder 38.6% Latex 1SMA 500.0 Additives 2,2,4-Trimethyl-1,3-hydroxypentyl 11.0 isobutyrate (Texanol) (coalescing solvent) Thickener based on associative 28.0 polyurethane (Rheolate 278) Water 14.0 Antifoaming agent (Byk 023) 1.5 1000
[0096] The constituents of the pigment paste were introduced in the order shown and the mixture was dispersed for 20 minutes at high speed with cooling.
[0097] The binder and the additives were successively added, in the order shown, with stirring to the pigment paste thus prepared, and the mixture was kept slowly stirred for 20 minutes.
[0098] The paint thus obtained exhibits the following characteristics:
PVC: 40 Solids content by mass: 55.7 Solids content by volume: 40.2 Density: 1.35
Examples 15 to 17 (Invention) and 18 and 19 (Comparative)
Evaluation of the Blocking of Tannins on Merbau
[0099] A first coat of the treatment or of the coating to be tested is applied to a merbau plank. These coatings are shown in table 4 below.
[0100] After drying for 4 hours, a coat of standard aqueous paint which has no ability to block tannins is applied as finish.
[0101] Depending on the isolating capability of the treatment or of the coating, a more or less pronounced yellowish coloring of the finishing coat may be observed in the minutes which follow. This coloring can be evaluated visually or by colorimetry by measuring the difference in color with respect to the finishing paint applied to a neutral support.
[0102] The difference in color DE* (in CIE Lab coordinates) is calculated by the formula:
DE*?{square root}{square root over (DL* 2 ?Da* 2 ?Db* 2 )}
[0103] with:
[0104] L*=the lightness
[0105] a*=the redness
[0106] b*=the yellowness
[0107] Evaluations lead to the results also reported in table 4.
TABLE 4 15 18 (Inven- 17 (Comp.) tion) (Comp.) Known 19 Solution 16 Paint of acrylic (Comp.) Example of (Invention) example dispersion* Known Treatment/ iSMA Latex 14 of the (nonactive active Coating No. 1 L 1SMA No. 1 invention latex) latex** Visual Faintly Faintly Faintly Strongly Colored appearance colored colored colored colored DE* 2.8 2.3 2.5 5.6 4.1
Examples 20 to 22 (Invention) and 23 (Comparative)
Evaluation of the Resistance of Coatings to Flash Rusting
[0108] The coating to be tested as shown in table 5 is applied to untreated steel and the appearance of rust stains at the surface of the film is recorded after drying.
TABLE 5 Example 20 21 22 23 Coating iSMA Latex Paint of Known solution L iSMA No. 1 example 14 acrylic No. 1 of the dispersion* invention Flash Very Very Very Pronounced rusting slight slight slight
Examples 24 (Invention) and 25 (Comparative)
Evaluation of the Resistance to Water and to Alkaline Hydrolysis
[0109] The latex to be tested is applied to a Leneta card for the purpose of obtaining a dry film with a thickness of 3 mm, and drying is allowed to take place for 2 hours before applying, at the surface of the film, for 10 minutes, a drop of demineralized water or a drop of 2% aqueous sodium hydroxide solution.
[0110] The deterioration in the film is then recorded qualitatively by assigning a grading ranging from 0 (film destroyed) to 5 (undamaged film).
[0111] The evaluations carried out lead to the results reported in table 6 below.
TABLE 6 Example 24 (Invention) 25 (Comparative) Latex L 1SMA No. 1 L SMA of example 7 Resistance to 5 5 water Alkaline 5 0 resistance
Example 26
Applicative Evaluation on a Chalking Face
[0112] A. Preparation of the Chalking Face
[0113] The chalking face is composed of a mixture of calcium carbonates and of titanium oxide (Durcal 10 and TiO2 RL 68) dispersed in a 2% solution of cellulose thickener based on Natrosol 250 HR, which is applied by spraying over an agglopan board (fiber cement) in increasing thickness.
[0114] B. Application of the Primers
[0115] The primer, composed of the unformulated latices, is applied with a brush and in excess to the chalking face prepared above, the primer being applied at different dilutions.
[0116] The reference primer in a solvent phase, sold by La Seigneurie under the name of Impriderme P, is also applied to the same board, an area of primer-free nonchalking face also being retained as reference.
Without Solids 12% 6% 3% 1.5% Impriderme primer content ? ? ? ? ? ? Thickness of 20 μm ? the chalking 50 μm ? face 100 μm ? 150 μm ?
[0117] Diagram of the Application to the Board
[0118] C. Application of the Finish
[0119] After drying for 24 h at 23° C. and 50% RH, a finish based on a gloss paint exhibiting a Pigment Volume Concentration (PVC) of 17% or a matt paint exhibiting a PVC of 81% is applied with a roller and drying is allowed to take place for 8 days at ambient temperature.
[0120] D. Adhesion Measurements
[0121] The adhesion of each finish to the primer-impregnated face is evaluated. To measure this adhesion, a cross is drawn with a cutter by incising as far as the support, a piece of adhesive tape is adhesively bonded to the cut region and then it is torn off in a swift movement.
[0122] The deterioration in the film is evaluated by a grading from 0 (bad) to 10 (excellent), according to the level of residual adhesion of the paint film and to its degree of deterioration.
Without Ultrafine Test L 1SMA No. 1 primer Impriderme PR 3500 12% 5.5 1 9 5.7 6% 9 1 9 8.9 3% 7.1 1 9 6.4
[0123] E. Grading* Obtained for the Latices Examined
[0124] The grading is the mean value of all 3 of the measurements carried out for each example at a given dilution.
Example 27
Applicative Evaluation on Plaster
[0125] The substrate is a square of prefabricated plaster with a smooth (slightly glossy) and cohesive (no chalking) surface. The primer is applied with a brush and in excess in one pass, at different dilutions (solids content of 12% to 1.5%).
[0126] After drying for 24 h, the system is brought to completion by application of a coat of matt or gloss paint identical to the paints mentioned above and the adhesion is tested in the same way as on a chalking face.
Dilution/ Without Ultrafine Product L iSMA No. 1 Impriderme primer PR 3500 12% 8.6 7.3 3 7.1 6% 8.8 8.0 3% 9.0 6.2 1.5% 8.0 6.8
[0127] Grading Obtained for the Latices Examined
[0128] * The grading is the mean value of all 3 measurements carried out at a given dilution. | Substrates having a water-soluble substance subject to migration toward the surface of the substrate are treated or coated with a composition comprising a a latex or solution of a film forming polymer and sufficient imidized maleic anhydride polymer dispersant or emulsifier to inhibit the migration toward the surface of the water-soluble substance. Preferably a styrene-maleic anhydride polymer is imidized with a diamine and is made cationic by neutralizing with an acid. The imidized polymer is preferably the only surfactant or dispersant in the latex composition. Pigment pastes and primers comprising the imidized polymer can be applied to substrates to confer water and alkaline hydrolysis resistance and to prevent the migration of any water soluble substance in the substrate. | 2 |
BACKGROUND
[0001] This disclosure relates to a metering valve for a fuel metering system.
[0002] Gas turbine engines are known, and typically include a compressor compressing air and delivering it to a combustor. The compressed air is mixed with fuel in the combustor, combusted, and the products of combustion pass downstream over turbine rotors, driving the rotors to create power.
[0003] The metering valve provides metered flow to the combustor, provides position feedback to the full authority digital engine controller (FADEC), moves in response to a FADEC command, shuts fuel flow off in response to a FADEC command and provides pressure signals to various fuel system components.
SUMMARY
[0004] In one exemplary embodiment, a metering valve for a gas turbine engine fuel system includes a sleeve including first, second, third, fourth, fifth and sixth ports respectively axially spaced apart from one another. A spool is slidably received in the sleeve and includes first, second and third seal lands. The first seal land selectively connects the first and second ports to one another, and the third seal land selectively connects the third and fourth ports to one another and the fifth and sixth ports to one another.
[0005] In another exemplary embodiment, a fuel system for a gas turbine engine includes a pump configured to pump fuel from a tank. A metering valve is fluidly connected to and arranged downstream from the pump. The metering valve includes a sleeve including first, second, third, fourth, fifth and sixth ports respectively axially spaced apart from one another. A spool is slidably received in the sleeve and includes first, second and third seal lands. The first seal land selectively connects the first and second ports to one another, and the third seal land selectively connects the third and fourth ports to one another and the fifth and sixth ports to one another. The first and fourth ports are fluidly connected to one another irrespective of spool position. The second port is fluidly connected to and downstream from the pump.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The disclosure can be further understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
[0007] FIG. 1 is a schematic of a portion of a fuel system for a gas turbine engine.
[0008] FIG. 2A is a cross-sectional view of a metering valve with a housing, sleeve and spool.
[0009] FIG. 2B is a perspective view of the sleeve illustrating various ports.
[0010] FIG. 3A is a cross-sectional view of the metering valve with the spool in a position permitting partial flow through a P 2 port in the sleeve.
[0011] FIG. 3B is a cross-sectional perspective view of the metering valve with the spool in a position permitting flow through a P 2 port in the sleeve to a PGI port.
[0012] FIG. 4A is a cross-sectional view of the metering valve with the spool in the position fully blocking flow through the P 2 port.
[0013] FIG. 4B is a cross-sectional view of the metering valve with the spool in the position permitting full flow through the P 2 port.
[0014] FIG. 5A is a cross-sectional perspective view of the metering valve with the spool in a position permitting flow through a PR port in the sleeve to a BDCV port.
[0015] FIG. 5B is an enlarged cross-sectional perspective view of the metering valve illustrating the unblocked BDCV port.
[0016] FIG. 6 graphically depicts the flow regulating area of various ports at particular spool positions; graph A depicts the flow regulating area connecting the P 1 and P 2 ports; graph B depicts the flow regulating area connecting the P 2 and PGI ports; graph C depicts the flow regulating area connecting the PR and BDCV ports.
DETAILED DESCRIPTION
[0017] A highly schematic view of a fuel system 10 for a gas turbine engine 30 is shown in FIG. 1 . It should be understood that various fluid connections and components are omitted from the schematic for clarity. The fuel flowing in the various lines within the system 10 are labeled with the prefix “P.”
[0018] The system 10 includes a main pump 14 that pumps fuel from a tank 12 . Fuel from the pump 16 flows through the main filter 18 to the metering valve (MV) 26 and the pressure regulating valve (PRV) 28 . The pump 14 also supplies fuel PFA to fueldraulic actuators 21 and the servo pressure regulator (SPRV) 24 .
[0019] Upstream fuel P 1 from the pump 14 is provided to a metering valve (MV) 26 . The MV 26 is responsive to main gear pump inlet fuel PGI, SPRV regulated pressure fuel PR, and a modulated pressure PM. The regulated pressure fuel PR is provided by a servo pressure regulator (SPR) 24 that is responsive to the main gear pump inlet fuel PGI and pump outlet fuel PFA. The modulated pressure PM is from a servo valve 22 that responds to FADEC commands for positioning the MV 26 . The MV 26 produces a downstream pressure P 2 that is provided to the engine combustor. The PRV 28 is also responsive to the upstream fuel P 1 via port 44 and downstream fuel pressure P 2 via port 42 to produce a bypass flow, discharge pressure fuel PDI. This bypass flow is sent to a bypass directional control valve (BDCV) 32 , which sends the bypass flow back to one of two possible low pressure locations upstream of the pump, depending on the state of the BDCV. The BDVC 32 is also responsive to the pressure regulator fuel PR, the PBDCV signal from the MV and PGI.
[0020] The ports and their respective flow directions are shown in FIGS. 2A and 2B . A FADEC 39 is in communication with the MV 26 through a servo valve 22 which positions the MV using the modulated pressure PM. The FADEC also receives MV position information through an LVDT connected to the MV.
[0021] The MV 26 includes a housing 34 , which contains various fuel lines, schematically depicted in FIG. 1 . A sleeve 36 is received in the housing 34 and sealed relative thereto by seals, such as O-rings, to fluidly separate the fuel inlets and outlets provided in the housing 34 . A spool 38 is slidably received within the sleeve 36 and is responsive to fuel pressures acting on the spool 38 to selectively communicate fuel to various components within the system 10 . To this end, the spool 38 includes first, second and third seal lands 56 , 58 , 60 . The first and third seal lands 56 , 60 selectively block and unblock some of the ports 40 - 54 .
[0022] Referring to FIG. 3A , the sleeve 36 includes a first P 1 port selectively in fluid communication with the first P 2 port 42 . In particular, the first seal land 56 selectively fluidly connects the first P 1 port through the annular space between the first and second seal lands 56 , 58 when the first seal land 56 moves from the fully blocked position ( FIG. 4A ) to the fully open position ( FIG. 4B ). The timing of this event is determined in part by the first diameter D 1 , first W 1 and position L 1 of the first seal land 56 relative to the left end of the spool 38 . In the example, the ratio L 1 /W 1 is 1.40-1.50, and for example, 1.44; the ratio W 1 /D 1 is 0.58-0.68, and for example, 0.63.
[0023] The second P 2 port 46 is fluidly connected to the first P 2 port 42 through housing plumbing lines.
[0024] The first P 2 port 42 includes two windows having a total area of 0.261 inch 2 (0.66 cm 2 ) with axially elongated portions that permits a gradual flow (as the spool 38 moves from right to left in the figure) before becoming fully opened, as graphically depicted in FIG. 6A . The first P 1 port 40 includes four windows that are generally rectangular in shape to maximize flow through the port during the entire opening stroke of the spool 38 . The first P 1 port 40 includes a total area of 1.712 inch 2 (4.35 cm 2 ).
[0025] Referring to FIG. 3B , the second P 2 port 46 and the PGI port 48 are fluidly connected (with the spool 38 all the way to the right in the figure) and the first P 2 port 42 fully blocked. In this position, the BDCV port 50 is blocked by the third seal land 60 . The third seal land 60 is at a second position L 2 from the left end and includes a second width W 2 and a second diameter D 2 . The ratio of D 2 /W 2 is 6.32-6.42, and for example, 6.37; the ratio of W 2 /D 2 is 0.95-1.10, and for example 1.05. The timing of the fluid connection and change in flow regulating area between the second P 2 port 46 and the PGI port 48 is graphically shown in FIG. 6B .
[0026] Referring to FIGS. 5A and 5B , the PR port 52 and the BDCV port 50 are fluidly connected with the spool 38 to the left. The BDCV port 50 is rectangular in shape to maximize flow through the port. The total area of the BDCV port 50 is less than the total area of the PR port 52 . The timing of the fluid connection and change in flow regulating area between the PR port 52 and the BDCV port 50 is graphically shown in FIG. 6C .
[0027] Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For example, part areas may be within +/−5% of the specified areas. For that reason, the following claims should be studied to determine their true scope and content. | A metering valve for a gas turbine engine fuel system includes a sleeve including first, second, third, fourth, fifth and sixth ports respectively axially spaced apart from one another. A spool is slidably received in the sleeve and includes first, second and third seal lands. The first seal land selectively connects the first and second ports to one another, and the third seal land selectively connects the third and fourth ports to one another and the fifth and sixth ports to one another. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-In-Part of application U.S. Ser. No. 728,229, filed Oct. 10, 1996 in the name of Sohan L. Uppal for a "STEERING CONTROL UNIT", now U.S. Pat. No. 5,799,694, and is also a Continuation-In-Part of co-pending application U.S. Ser. No. 862,887, filed May 23, 1997, in the name of Sohan L. Uppal, for an "IMPROVED COUPLING FOR USE IN A GEROTOR DEVICE".
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE DISCLOSURE
The present invention relates to torque generator steering devices, and more particularly, to such devices in which a relatively low torque steering input is translated into a relatively high torque steering output, with the assistance of a source of pressurized fluid.
Torque generators of the type to which the present invention relates have been in commercial use for many years, have been commercially quite successful, and are illustrated and described in greater detail in U.S. Pat. Nos. Re. 25,291 and 4,936,094, both of which are assigned to the assignee of the present invention and are incorporated herein by reference.
In the typical prior art torque generator of the type illustrated and described in the above-incorporated patents, there are three sections: (1) an input section including an input shaft; (2) a fluid displacement mechanism (typically a gerotor gear set); and (3) a valving section, including an output shaft. In the commercially available torque generators, these three sections have always been arranged "serially", i.e., one section after another, axially, starting with the input section and ending with the output section. As a result, the commercial torque generators have been fairly large (i.e., long in the axial direction).
Although the prior art torque generator has been commercially successful, and its design has remained basically unchanged for many years, its market penetration has been somewhat hindered by the overall size of the device. For example, there are many small tractors in use on which torque generator steering devices could be applied on an "after-market" basis, but the overall length of the prior art torque generator prevents it from physically fitting within the available length of the steering column on a number of tractors.
The torque generator currently commercially available from the assignee of the present invention includes two sets of internal splines, and two dogbone shafts which together include three sets of crowned, external splines. The result can be an undesirable amount of looseness or backlash in the mechanical connection between the input shaft and the output shaft, thus hindering the use of the prior art torque generator in certain vehicle applications.
BRIEF SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved torque generator steering device which is inherently smaller and more compact than in the prior art, thus providing greater value to the vehicle manufacturer.
It is a more specific object of the present invention to provide an improved torque generator steering device which does not consist of different sections arranged axially, but instead, overlaps or "nests" the various sections to reduce substantially the overall length of the device.
It is a related object of the present invention to provide an improved torque generator steering device having fewer spline connections, thus substantially reducing the backlash of the device.
The above and other objects of the invention are accomplished by the provision of an improved torque generator steering device adapted to receive a relatively low torque steering input and generate a relatively high torque steering output by means of a source of pressurized fluid. The steering device comprises housing means defining a fluid inlet port in communication with the source, and a fluid outlet port. A fluid energy-translating displacement means is associated with the housing means and includes a rotor member having relatively high torque rotary motion in response to the flow of the pressurized fluid through the displacement means. A valve means is disposed in the housing means and has a neutral position and an operating position in which the valve means and the housing means cooperate to define a fluid path communicating pressurized fluid from the inlet port to the displacement means, and-from the displacement means to the outlet port. The valve means comprises a rotatable, primary valve member and a relatively rotatable follow-up valve member. An input shaft is operable to transmit the relatively low torque steering input into movement of the valve means from the neutral position to the operating position. A follow-up means is operable to transmit the rotary motion of the rotor member into follow-up movement of the valve means from the operating position toward the neutral position. An output shaft is operable to transmit the relatively high torque rotary motion of the rotor member into the relatively high torque steering output.
The improved steering device is characterized by the housing means comprising, at its upstream end, an endcap member having the input shaft extending therethrough. The displacement means comprises a gerotor gear set disposed adjacent the endcap member and including an internally toothed ring member fixed relative to the housing means, the rotor member comprising an externally toothed star member having orbital and rotational movement relative to the ring member. The input shaft extends axially through the star member and is fixed to rotate with the primary valve member. The primary and follow-up valve members are disposed on the output shaft end of the gerotor gear set. The follow-up means comprises the follow-up valve member including a terminal portion disposed immediately adjacent the star member and the terminal portion and the star member including coupling means operable, in response to the rotational movement of the star member, to transmit the orbital and rotational movements into a rotational follow-up movement to the follow-up valve member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial cross-section of a torque generator steering device made in accordance with the present invention.
FIG. 2 is a fragmentary, flat, plan view illustrating the primary valve member of the steering device of FIG. 1.
FIG. 3 is a fragmentary, flat, plan view, similar to FIG. 2 illustrating the follow-up valve member of the steering device of FIG. 1.
FIG. 4 is an enlarged, fragmentary view, similar to FIG. 1, illustrating the coupling arrangement of the present invention, for providing follow-up movement to the follow-up valve member.
FIG. 4a is an axial cross section, similar to FIG. 4, but illustrating only the coupling member which comprises one important aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, which are not intended to limit the invention, FIG. 1 illustrates a torque generator steering device, generally designated 11, which is made in accordance with the teachings of the present invention. The steering device 11 includes several sections, held in tight sealing engagement by a plurality of bolts 13 (only one of which is shown in FIG. 1. Thus, the steering device 11 includes an endcap member 15, a gerotor displacement mechanism 17, and a valve housing section 19. Extending through a central opening in the end cap member 15 is an input shaft 21, and similarly, extending through a central opening in the valve housing section 19 is an output shaft 23.
The valve housing section 19 defines an inlet port 25, which is typically connected to a source of pressurized fluid (not shown herein), and an outlet port 27, which is typically connected to the system reservoir, or to a downstream fluid pressure operated device (neither of which are shown herein).
The gerotor displacement mechanism 17, as is well known to those skilled in the art, includes an internally toothed ring member 29, and an externally toothed star member 31. Typically, the star member 31 has one less tooth than the ring member 29, and is eccentrically disposed therein for relative orbital and rotational movement. In the subject embodiment, the ring member 29 is stationary, having the bolts 13 extending therethrough, such that the star member 31 has both the orbital and rotational movements.
As the orbital and rotational movement of the star member 31 occurs, the toothed interaction between the members 29 and 31 defines a plurality of expanding fluid volume chambers 33 (see FIG. 4), and a plurality of contracting fluid volume chambers 35, in a manner also well known to those skilled in the art.
Disposed within the valve housing section 19 is the appropriate valving to effect the communication of fluid from the inlet port 25 to the expanding volume chambers 33, and from the contracting volume chambers 35 to the outlet port 27.
As is generally well known in the art, the torque generator valving includes a primary, rotatable valve member 37, and a relatively rotatable follow-up valve member 39. It is one important aspect of the present invention that the primary valve member 37 is fixed to rotate with the input shaft 21, and that the follow-up valve 39 is fixed to rotate with the output shaft 23. Furthermore, in the subject embodiment, the primary valve member 37 is formed integrally with the input shaft 21, while the follow-up valve member 39 is formed integrally with the output shaft 23, thus reducing the overall number of parts from that needed in the prior art torque generator.
The valve housing section 19 defines a valve bore 41, which receives the follow-up valve member 39 therein, in a relatively close fit relationship. Similarly, the follow-up valve member 39 defines an internal bore 43 which receives the primary valve member 37 therein in a relatively close fit relationship. The fits among the bores and valve members can be substantially the same as those currently utilized in torque generators, and because such fits are not an essential feature of the invention, they will not be discussed further herein.
The valve housing section 19 defines a fluid passage 45 extending from the inlet port 25 to the valve bore 41, and a fluid passage 47 extending from the bore 41 to the outlet port 27. Either or both of the passages 45 and 47 may comprise annular grooves defined by the housing section 19, and "surrounding" the valve bore 41. In addition, the valve housing section 19 defines a plurality of angled passages 49, each of which communicates from the valve bore 41 to a rearward surface of the housing 19, at a location such that each passage 49 is in fluid communication with one of the volume chambers 33 or 35.
Referring now to FIG. 2, the valving of the torque generator steering device will be described in some detail. The primary valve member 37 is also referred to as a "spool" valve, and the follow-up valve member 39 is also referred to as a "sleeve" valve. The spool valve 37 includes an annular groove 51, disposed toward the left end of the spool 37, and in fluid communication with the groove 51 is a plurality of axially extending slots 53. Disposed between each pair of adjacent slots 53 is a shorter axial slot 55, each of which includes a radial bore 57 providing communication between the slot 55 and a central, axial drain bore 59 (see FIG. 1).
Disposed to the right in FIG. 2 of the slots 53 and 55, the spool 37 defines a pair of diametrically opposite, circumferentially-elongated openings 61. To the right of the openings 61 is another pair of diametrically opposite, circumferentially-elongated openings 63, and as may best be seen in FIG. 2, the openings 63 are elongated further in the circumferential direction than are the openings 61 for reasons which will become apparent subsequentially.
Referring now primarily to FIG. 3, the sleeve 39 defines a reduced diameter portion 65 at the junction of the sleeve valve 39 and the output shaft 23, and that reduced diameter portion 65 defines several openings 67 which facilitate communication of case drain fluid from the drain bore 59 out to the outlet port 27.
To the right of the openings 67 the sleeve 39 defines a plurality of pressure ports 69 which are in continuous fluid communication with the passage (annular groove) 45, such that the ports 69 contain pressurized fluid from the inlet port 25. To the right of the ports 69, the sleeve 39 defines a plurality of meter ports 71 which are in commutating fluid communication with the angled passages 49, in a manner well known to those skilled in the steering art. Disposed to the right of the meter ports 71, the sleeve 39 defines a pair of diametrically opposite openings 73, disposed in a reduced diameter portion 75 located at the right end of the sleeve (see FIG. 1). The function of the openings 73 and the portion 75 will be described subsequently.
As illustrated in FIGS. 2 and 3, the torque generator steering device of the present invention includes valving which may be characterized as "open-center". With no manual steering input being exerted on the input shaft 21, a centering spring 76 biases the spool valve 37 and the sleeve valve 39 toward the neutral position, relative to each other. When the spool 37 and sleeve 39 are in neutral, each of the meter ports 71 overlaps both a slot 53 and an adjacent slot 55. Therefore, pressurized fluid entering the inlet port 25 flows through the passage 45, then through the pressure ports 69 into the annular groove 51. From there, fluid flows into the slots 53, then radially out through one of the meter ports 71, then radially inward into the adjacent slot 55. Fluid in the slots 55 then flows radially inward through the bores 57, then to the left (in FIG. 1) in the drain bore 59, and then radially out through notches 60 (see FIG. 2) in the spool 37, then through the openings 67 to the outlet port 27.
When an input steering torque is applied to the input shaft 21, the spool 37 is rotated relative to the sleeve 39, in opposition to the biasing force of the centering spring 76, such that each of the meter ports 71 is no longer communicating with both a slot 53 and a slot 55. Instead, each meter port 71 which is instantaneously in communication with an expanding volume chamber 33, through one of the angled passages 49, is in communication with only a slot 53, and thus communicates pressurized fluid from the inlet port 25 to the expanding chambers 33. At the same time, each of the meter ports 71 which is in communication with one of the contracting fluid volume chambers 35, through an angled passage 49, is in instantaneous communication with only an axial slot 55, such that fluid being exhausted from the contracting chambers 35 is communicated to the outlet port 27 in the manner described previously.
Referring now primarily to FIG. 4, in conjunction with FIG. 1, another important aspect of the present invention will be described. As was mentioned in the BACKGROUND OF THE DISCLOSURE, the prior art torque generator has included two dogbone shafts, one to transmit orbital and rotational movement of the star into rotary follow-up motion of the follow-up valve member, and the other to transmit orbital and rotational movement of the star into rotational motion of the output shaft. In accordance with the present invention, the need for those dogbone shafts is eliminated. Instead, the present invention utilizes a coupling arrangement of the type illustrated and described in co-pending application U.S. Ser. No. 862,887, filed May 23, 1997, in the name of Sohan L. Uppal, for an "IMPROVED COUPLING FOR USE WITH A GEROTOR DEVICE", which is incorporated herein by reference.
The coupling arrangement, generally designated 77, includes a hollow, generally cylindrical coupling member 79 which preferably may comprise a fairly simple and inexpensive member, such as a die cast member or a powdered metal part, etc. The coupling member 79 does not have a uniform wall thickness, as may best be seen in FIG. 4a, but instead, the outside diameter of the member 79 is cylindrical, while the inside diameter increases (and the wall thickness decreases) from the middle toward a forward end portion 79a and toward a rearward end portion 79b.
The coupling member 79 defines a pair of forward notches 81, disposed diametrically opposite each other, and a pair of rearward notches 83, also disposed diametrically opposite each other. In the subject embodiment, and by way of example only, the notches 81 and 83 are circumferentially aligned with each other.
The coupling arrangement 77 includes a forward pin 85 which extends through the openings 63 in the spool 37, and through the forward notches 81 in the coupling member 79. The outer, opposite ends of the pin 85 are pressed into recesses 87 formed in the forward, radially inner portion of the star 31. The coupling arrangement 77 also includes a rearward pin 89 which extends through the openings 61 in the spool 37, through the openings 73 in the sleeve 39, and then through the rearward notches 83 in the coupling member 79. The opposite ends of the pin 89 are restrained by the valve bore 41, or alternatively, by a slightly larger counter bore disposed toward the forward end (right end in FIG. 1) of the valve bore 41.
As the star 31 orbits and rotates, the forward end portion 79a orbits and rotates, because of the pin 85 and the notches 81. This orbital and rotational movement is translated, as is well known to those skilled sin the art, into pure rotational movement of the rearward end portion 79b. This rotational movement of the rearward end portion 79b is translated into follow-up rotation of the sleeve 39 by means of the notches 83 and the pin 89. The pins 83 and 85 pass through the circumferentially-elongated openings 61 and 63, respectively, such that there is a certain amount of relative rotation permitted between the spool 37 and the sleeve 39, even as the follow-up motion is being transmitted from the star 31 to the sleeve 39.
Those skilled in the art will understand that the present invention is not limited to the particular coupling arrangement 77 shown herein, but what is essential to the invention is that the sleeve 39 include a terminal portion disposed adjacent the star 31, so that the orbital and rotational movement of the star can be directly translated into follow-up movement of the sleeve, without interfering with the input shaft and spool valve, and the rotation thereof relative to the sleeve.
The invention has been described in great detail in the foregoing specification, and it is believed that various alterations and modifications of the invention will become apparent to those skilled in the art from a reading and understanding of the specification. It is intended that all such alterations and modifications are included in the invention, insofar as they come within the scope of the appended claims. | A torque generator steering device (11) including a gerotor gear set (17) disposed adjacent an end cap (15) and having the input shaft (21) extending through the end cap and through the orbiting and rotating star member (31). The valving of the device, including a spool valve (37) and a sleeve valve (39), is disposed on the side of the gerotor gear set (17) toward an output shaft (23). Preferably, the input shaft (21) is integral with the spool valve (37), and the sleeve valve (39) is integral with the output shaft (23). A coupling arrangement (77) is provided to translate orbital and rotational movement of the star (31) into rotational follow-up movement of the sleeve valve (39). The result is a very short, compact torque generator having substantially reduced backlash between the input shaft (21) and the output shaft (23). | 5 |
This application is a continuation of application Ser. No. 08/469,818, filed Jun. 6, 1995, now abandoned, which is a divisional of U.S. Ser. No. 08/238,055, filed May 4, 1994 abandoned.
The present invention relates to a process for molding a make-up composition by casting in a mold, in fluid form, and solidifying the composition, so as to obtain a solid molded product in the form of a block or cake, it being subsequently possible for the composition to be picked off from the molded product with the aid of a finger, a brush or of a puff; the invention also relates to the product obtained by this process.
The make-up composition to be molded may be in the form of a paste obtained by mixing a solid particulate phase either with an aqueous phase or with a binding agent, especially a fatty phase, in a solvent; it may also be in the form of a product based on a heat-fusible wax or of a gel which is cast in the hot state. Depending on the composition employed, the solidification therefore takes place either by evaporation of water or of solvent, or by cooling, or by chemical reaction.
It is known to cast a make-up composition in a mold of a certain volume including chiefly a molding surface which imparts its shape (flat, curved or provided with relief or indented figures) to the surface for taking off the composition and a bottom, in most cases flat, provided with one or more openings through which the composition to be molded is cast. Depending on the make-up composition which is processed, the phenomenon of shrinkage during the solidification may be considerable. This is the case especially with the compositions described in patents U.S. Pat. No. 4,804,538, EP-A-165,137 and DE-A-3,327,001. The molded block obtained is then packaged but, because of the shrinkage, its dimensions and its shape can vary, and it is difficult to keep it in place in this package and to wedge it against the rigid surface forming the bottom of the package such as a case; the main function of the rigid surface is to prevent the molded block from breaking up in the course of the various handling operations and to protect it, but the shrinkage destroys the wedging and prevents the packaging from fulfilling its function in a satisfactory manner. If the molded block is badly wedged it tends to break up in the course of storage; because of its nature it is actually very brittle because it must be capable of being disintegrated to allow it to be picked off.
To avoid this disadvantage it has already been proposed, in EP-A-191,198 and in EP-A-38,645, to perform the casting in a dish resting on a molding surface, the bottom of the dish being provided with crosspieces, reinforcement or other anchoring devices. On solidifying, the composition binds to the bottom of the dish and a product of molding is then packaged, including the solidified composition and its associated dish. The dish is used as a support for the solidified composition and, since the dish has determined dimensions, the molded product is easy to keep in place and to wedge in a rigid package. However, it has been found that after drying or cooling, cracks are formed because of shrinkage of the composition in relation to the dish and to the regions for bonding to the latter. The product sold is consequently embrittled and tends to fragment during the various subsequent handling operations, especially when the product is being used.
It is therefore desirable to define a packaging for this type of composition, which at the same time makes it possible to ensure the wedging and the maintaining of the solidified composition in a protective packaging eliminating the risk of breaking up and to permit the shrinking of the composition without embrittlement of the molded block; two functions must therefore be ensured simultaneously.
SUMMARY OF THE INVENTION
According to the present invention it has been found that the abovementioned disadvantages are avoided by employing a mold bottom including a sheet of open-cell foam which is partly impregnated with the cast composition. The process according to the invention makes it possible to ensure the two desirable functions defined above simultaneously with the product obtained.
The subject of the present invention is therefore a process for molding a make-up composition in a mold including a concave molding surface forming the base of the mold and a bottom forming an upper component of the mold and shutting off the space bounded by the said molding surface, the composition being cast in the mold in fluid form and subsequently solidifying to form a demoldable solid product capable of being packaged, characterized in that the said composition is cast in a mold the bottom of which is at least partly formed by a sheet of open-cell plastic foam, so as partly to impregnate the foam sheet with the composition. After solidification of the composition a molded product, including the solidified composition and the foam sheet which is bonded to it and which forms its support, is demolded by removing the molding surface.
It has been found that, in the process according to the invention, compositions exhibiting a high shrinkage during their solidification can be cast without the molded product obtained being fragile because the foam support adapts its shape to the dimensional changes in the solidified composition by virtue of its elasticity. Nevertheless, since the foam is partly impregnated with the composition, a bond is formed between the plastic foam sheet and the composition during the solidification and the said foam sheet forms a support for the solidified composition, a support which, of itself, contributes to the mechanical reinforcement of the molded block. A molded product is therefore prepared, including the combination of the solidified composition and the foam sheet. The unimpregnated portion of the foam sheet, more particularly the unimpregnated layer of the foam sheet, which has retained its elasticity, can be employed in the packaging of the molded product to wedge the latter onto a rigid surface by compensating the changes in dimensions of the solidified composition; the wedging is produced by a slight compression of the foam sheet. In addition, the solidified composition, being held in the package on an elastic surface, is properly protected against the impacts to which it might be subjected during the various handling operations. A good conservation of the molded product is therefore ensured as soon as it is manufactured, until it reaches the user's hands.
According to a first embodiment the composition is solidified after casting by cooling or by evaporation of a solvent present in the composition. According to another embodiment a composition which contains plaster (CaSO 4 .½H 2 O) and a sufficient quantity of water to obtain a pourable mixture is cast, the solidification taking place after casting by setting of the plaster. The molding process according to the invention is then particularly advantageous.
According to the invention the composition may be cast through the foam sheet; casting takes place preferably through an opening, advantageously a central opening, made in the foam sheet. The size of this opening is a function of the size of the mold and of the composition which is cast.
The foam sheet is preferably slightly compressed at the solidification stage, advantageously with the aid of a rigid plate; this rigid plate is advantageously provided with openings to facilitate the evaporation when the solidification takes place by evaporation.
The foam sheet employed according to the invention includes, as indicated above, an open-cell plastic foam. This foam is chosen so that it practically does not swell in the presence of the various ingredients of the make-up composition, such as water, oil and fatty substances, and so that it can be impregnated with the composition. A foam is advantageously employed which has a cell structure such that the volume occupied by the walls of the cells does not represent more than 3% of the total volume of the foam. The foam advantageously has a homogeneous cell structure, that is to say forming a three-dimensional network. Suitable plastic foams are, for example, crosslinked polyurethane foams, in particular those marketed under the names “Bulpren S 20”, “Bulpren S 30” and “Filtren S 2120” by the “Recticel” company.
The thickness of the foam sheet employed is a function of the size of the mold and of the composition which is cast. A suitable thickness is generally of the order of 3 to 6 mm.
Another subject of the present invention is the molded make-up product obtained by the process defined above.
This product is preferably packaged, after demolding, in a rigid display case including a component which supports the foam sheet and of a ring which surrounds the molded product and is integrally attached to the component.
In a first alternative form the component is a base which interacts with a ring which bears on the solidified composition to hold the molded product against the base, the base overlapping laterally in relation to the foam sheet.
In a second alternative form the component is a plate and the ring includes a means of integral fastening capable of ensuring peripherally, in a removable manner, its bonding to a cap in order to form a molding surface with it. In addition, the plate preferably includes at least one opening.
Provision can be advantageously made for the product according to the invention to contain hydrated plaster (CaSO 4 .2H 2 O), preferably in a proportion by weight of between 10 and 50%.
BRIEF DESCRIPTION OF THE DRAWINGS
The description given below, purely by way of illustration and without any limitation being implied, will make it possible to understand the invention better, reference being made to the attached drawings.
In the drawings:
FIG. 1 is a diagram of the various stages (a to f) of a first alternative form of the molding process according to the invention;
FIG. 2 shows an exploded view of a mold employed according to a second alternative form of the process according to the invention; and
FIG. 3 shows the various stages of use of the mold illustrated in FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the scheme shown in FIG. 1 :
in stage a, a thermoformed dish 1 , which forms a concave molding surface for the make-up composition is placed in position;
in stage b, a foam sheet 2 provided with a central opening 21 is placed in position in the dish 1 , this foam sheet 2 forming the bottom of the mold;
in stage c, a cosmetic composition A is poured in through the opening 21 , as shown by the arrow, and the mold is completely filled so as to impregnate the lower layer of the foam sheet 2 with composition A while leaving free the upper layer of the foam sheet, this upper layer consequently retaining its elasticity;
in stage d, the composition A is allowed to solidify; a mechanical bond is then formed between the foam sheet 2 and the solidified composition A;
in stage e, the molded product, including a curved tablet of solidified composition A and of the foam sheet 2 which forms its support, is removed from the mold;
stage f is the stage of packaging of the molded product; the molded product is held down on a rigid base 3 with the aid of a ring 4 while the foam sheet 2 is slightly compressed; the ring 4 bears on the tablet of composition A and the base 3 is integrally attached to the ring 4 to keep the foam compressed. In this way, by virtue of its elasticity, the foam sheet 2 makes it possible to compensate, in relation to the base 3 and the ring 4 , the deformations of the solidified tablet of composition A which are due to shrinkage during and after solidification. The tablet of composition A is therefore well supported and well wedged on the rigid base 3 without any risk of cracking of the solidified composition.
FIG. 2 shows an exploded view of the various parts forming a mold 100 for making use of a second alternative form of the process according to the invention, an alternative form which is preferred because it makes it possible to mold the molded product directly in the packaging. It is made up, firstly, of a molding surface in the form of a dish referred to as 101 as a whole, as can be seen in FIG. 3A, secondly of a foam sheet 102 in the form of a circular disc and, thirdly, of a rigid plate 103 also in the form of a circular disc, of the same area as that of the foam sheet 102 .
The molding surface 101 is made up, firstly, of a concave cap 111 on the edge of which is formed a cylindrical skirt 112 provided with an internal screw thread 113 and, secondly, with a removable ring 104 provided with an external screw thread 141 and capable of being fitted by screwing onto the skirt 112 . The screw thread 141 is situated slightly set back from a cylindrical surface 142 which extends the external surface of the skirt 112 when the ring 104 is screwed onto the cap 111 .
The inner surface of the ring 104 defines three zones of increasing diameter which are separated by shoulders: a zone of smallest diameter 143 which is situated on the side of the concave part of the cap 111 when the ring 104 is screwed onto the cap, a zone of larger diameter 144 which, allowing for the necessary clearance, is equal to the external diameter of the foam sheet 102 and a height which is lower than the thickness of the foam sheet 102 and, finally, a zone 145 of still larger diameter and of height which is close to the thickness of the rigid plate 103 . The foam sheet 102 is provided with a central opening 121 and the rigid plate 103 is provided with several openings 131 .
As illustrated in FIG. 3A, the ring 104 is fitted onto the cap 111 , the foam sheet 102 is arranged in the zone 144 of the ring 104 screwed onto the skirt 112 of the cap 111 , to form the molding surface 101 . The cosmetic composition is introduced through the central opening 121 in the foam sheet 102 until the cosmetic composition fills the zone 144 of the ring and impregnates the foam over a proportion of its thickness—generally half its thickness; a bond between the solidified composition and the foam sheet 102 is thus obtained after solidifying. The plate 103 is then fitted by pressure in the zone 145 of the ring 104 , slightly crushing the foam sheet 102 (see FIGS. 3B and 3C) on the shoulder between the zones 144 and 145 and thus ensures that the foam sheet is secured to the cast composition. This crushing can be performed before solidification is complete, in which case it takes part in the partial impregnation of the foam sheet 102 , or after solidification is complete.
The cosmetic composition is then allowed to dry. The cells in the foam and the openings 131 arranged in the sheet 103 permit the evaporation of the solvent when the cosmetic composition solidifies by evaporation and, consequently, final drying.
After drying, the cap 111 is parted from the ring 104 and a unit 103 , 102 , 104 is thus obtained which can be marketed directly; the marketing may also take place with the cap 111 which then serves as a lid for protecting the composition.
The solidified cosmetic composition is held on the plate 103 by virtue of the foam sheet 102 trapped between the ring 104 and the plate 103 . The stiffness of the plate 103 prevents any risk of breaking of the block forming the solidified composition. Nevertheless, the solidified composition can undergo shrinkage without cracking as a result of the elasticity of the foam sheet 102 .
It suffices for the user to unscrew the molding surface 101 to release the surface for picking off the molded makeup composition and to pick off the make-up composition with the aid of a brush or of a puff.
Two examples of application of the process according to the invention are given below (the quantities are shown in g).
EXAMPLE 1
Preparation of an eye shadow
A paste which has the following formulation is prepared:
Phase A
Talc
9.7
Chromium oxide
1.8
Ultramarine blue
0.7
Zinc stearate
0.7
Mica
5.3
Starch
1.7
Titanium mica
10.5
Hollow (single cavity) microspheres made of
1.4
vinylidene chloride-acrylonitrile copolymer
(density 0.02 g/cm 3 ) marketed under the name
“Expancel 551 DE” by the company.
“Kemanord Plast”
Phase B
Polyvinylpyrrolidone-hexadecene copolymer
0.2
Jojoba oil
0.5
Isopropyl myristate
0.7
Lanolin
0.4
Sweet almond oil
1.2
Preserving agents
Butylhydroxytoluene
0.015
Butylhydroxyanisole
0.015
Propyl para-hydroxybenzoate
0.1
Solvent
Cyclomethicone
65
In a first step the constituents of phase B are mixed with each other. The constituents of phase A are introduced, separately, into a mixer, followed by the solvent and the whole is homogenized. Then, phase B into which the preserving agents have been introduced, is in its turn introduced into the mixer and mixing again carried out until a homogeneous paste is obtained.
The paste obtained is cast, at ambient temperature, in the concave mold 1 shown in FIG. 1 . This mold is made of injection-molded polypropylene and is 60 mm in diameter and 20 mm in height. The bottom includes of a “Bulpren S 20” foam sheet 2 which is 6 mm in thickness and has a central opening 21 , 15 mm in diameter; the paste is introduced through the said central opening 21 . The molds are then placed in an oven at 40° C. for 55 hours. A product including the solidified composition integrally attached to the foam sheet 2 is then demolded; the demolded product is then held down on the rigid base 3 , of the same size as the foam sheet 2 , with the aid of the ring 4 , so as to leave free the surface for picking off. A lid can then be fitted onto the ring 4 or the whole (solidified composition bonded to the foam sheet 2 , ring 4 and base 3 ) can be introduced into a case.
The curved tablet of green-blue eye shadow which is obtained has a smooth and uniform surface which can be picked off easily with a finger or with a brush.
EXAMPLE 2
Blusher
A pulverulent mixture which has the following formulation is prepared:
Plaster (CaSO 4 .{fraction (1/2 )}H 2 O)
25
Talc
25
Talc coated with lauroyllysine, marketed under
10
the name “EP 90025 Talc Treated” by the
company “Mearl”
Hollow (single cavity) microspheres of
5
vinylidene chloride-acrylonitrile copolymer
(density 0.02 g/cm 3 ), marketed under the name
“Expancel 551 DE” by the company
“Kemanord Plast”
Mica
24
Calcium carbonate
5
Titanium dioxide
2
Red iron oxide
3.5
Black iron oxide
0.5
and an aqueous phase which has the following composition:
Water
120
Surfactant marketed under the name
4.5
“Glucquat 100” by the company “Amerchol”
4.5
Preserving agent
0.1
The pulverulent mixture and the aqueous phase are mixed in a mixer equipped with slow stirring for 5 minutes.
The mixture obtained is introduced into the mold shown in FIG. 2; this mold is identical in dimensions with the mold in Example 1. The molding surface 101 uses, in combination with the concave cap 111 , a ring 104 comprising three zones 143 , 144 , 145 , which have the following heights: 7, 2, 2.5 mm, and the following diameters: 66, 70, 71.5 mm, respectively.
A disc of a foam 102 sold under the trade name “Filtren S 2120” 3 mm in thickness and which has a central circular opening 121 20 mm in diameter is introduced by pressure into the zone 144 . The fluid composition is poured in through the opening 121 . A foam thickness of approximately 1.5 mm is impregnated with solution. Approximately 30 minutes after the mold is filled, a plate 103 which, allowing for the necessary clearance, has the same diameter as the zone 145 , is introduced by pressure into the ring 104 , and this compresses the foam layer on the shoulder between the zones 143 and 144 over 2 mm and secures the foam sheet onto the plate 103 . The plate comprises 24 uniformly distributed holes 1 mm in diameter to permit the final drying. The mold containing the solidified product is stored as is for approximately three days, and this allows the composition to dry because water vapor can escape through the openings 131 in the plate 103 . The product is then marketed as is. It suffices for the user to unscrew the cap 111 to release the surface for picking off and to pick off the make-up composition with the aid of a puff or of a brush. | Process for moulding a make-up composition in a mould comprising a concave moulding surface forming the base of the mould and a bottom forming the upper component of the mould and closing off the space bounded by the said moulding surface, the composition being cast in the said mould in fluid form and subsequently solidifying to form a demouldable solid product capable of being packaged, in which the said composition is cast in a mould ( 1 ) whose bottom consists at least partly of a sheet ( 2 ) of open-cell plastic foam, so as partly to impregnate the said foam sheet ( 2 ) with the said composition and in which, after solidifying of the said composition, a moulded product consisting of the solidified composition and of the foam sheet which is bonded to it and which forms its support, is demoulded by removing the moulding surface ( 1 ). | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of Ser. No. 705,333 filed July 14, 1976, and now U.S. Pat. No. 4,080,238 continuation-in-part of Ser. No. 763,145 filed Jan. 27, 1977 now U.S. Pat. No. 4,126,504 and is related to U.S. Pat. No. 3,994,764, all assigned to the assignee of the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for adhesively joining pipes.
2. Description of the Prior Art
Pipes are currently joined by soldering, welding, threading, bonding with epoxy adhesives, bonding with polyvinylchloride adhesives in the case of PVC pipe, or using butts and straps. Threading, soldering and welding methods require skilled tradesmen and are therefor costly.
Epoxy adhesives are the bonding material of choice where the pipes are to be used to convey hot water or steam since they have the requisite chemical inertness and resistance to high temperatures. In addition, epoxy adhesives are particularly useful to join pipes of diverse materials. Adhesiveness may vary significantly from material to material with particular adhesives. Thus, an adhesive which is satisfactory for bonding steel may be inadequate for bonding a glass fiber reinforced resin. Epoxy adhesives have good adhesiveness with a broad range of materials and thus are extremely useful in bonding pipes having different compositions. As used, the epoxy adhesive comprises a two package composition which is mixed together prior to coating. The pot life of the mixed adhesive is short, being less than 30 minutes. After the pipe ends are coated and joined together the joints are heated, as by heating blankets, to accelerate the cure. Depending on the size of the joint, this takes from 10 to 60 minutes. During the heating step the epoxy adhesive becomes very fluid prior to cure. As a result, the adhesive flows out of the joint to form "icicles" which eventually harden and impede the flow of fluid through the pipe. As much as 75% of a pipe opening can be closed off due to the formation of "icicles" in this manner, and increased pumping costs and reduced efficiency of the piping system are the inevitable result. Also, because of the limited pot life of the epoxy adhesives when working with large diameter pipes, i.e., 6-12 inches, it is difficult to completely seal the surface before the adhesive sets up.
SUMMARY OF THE PRESENT INVENTION
The present invention is directed to a process for joining pipe of the same or diverse compositions by coating the ends to be joined with adhesives which have long pot lives and which avoid the problems encounted heretofore.
The main object of this invention is to provide a simple and relatively inexpensive process to join together pipe sections of the same or diverse compositions employing an adhesive having a long pot life, and requires no heat treatment or other external manipulative treatment to effect a cure, which does not obstruct the pipe interior which forms a strong bond, and which retains sufficient strength under hot water or steam temperatures and under adverse environmental conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The difficulties enumerated above are obviated by employing the adhesives of U.S. Pat. No. 3,994,764 and applications Ser. Nos. 705,333 and 763,145 referred to above which are hereby incorporated by reference in this application.
The adhesive of U.S. Pat. No. 3,994,764 is a two part composition consisting of, as a first part, a solution of a non-reactive thermoplastic polyurethane polymer resin dissolved in a polymerizable acrylic monomer and copolymerizable acid monomer, the solution containing a non-activated free radical polymerization catalyst having a half-life of at least one half hour at 80° C. The second part of the adhesive composition comprises a tertiary amine free radical polymerization catalyst activator.
Examples given in the patent of the acrylic and acid monomer are methacrylate esters and amides, methacrylic and acrylic acids and half esters of 2-hydroxyethyl acrylate with dicarboxylic acids, such as maleic, oxalic, itaconic, terephathilic and the like. The preferred catalyst is benzoyl peroxide and the preferred activator is a tertiary amine such as R 1 R 2 R 3 N wherein R 1 and R 2 are lower alkyl and R 3 is phenyl, tolyl or xylyl. Illustrative are N N, dimethyl-p-toluidine, dimethyl aniline or diethyl aniline. Salts of copper, lead or other heavy metals may be added to the accelerator to act as activators.
The first part of the adhesive has a high degree of stability in the absence of an activator for polymerization catalyst. In use, one surface is coated with the first part and the other surface with the second part. On joining the surfaces bonding takes place.
Application Ser. No. 705,333 is directed to a one-liquid adhesive, similar in composition to that disclosed in U.S. Pat. No. 3,994,764. Here, however, the amine activator is encapsulated in pressure rupturable microspheres which are normally insoluble in the adhesive mixture. In use the adhesive is coated on one or both surfaces, which are then joined together with sufficient pressure to break the microspheres. Alternatively the microspheres are ruptured in the adhesive mixture which is then applied.
Application Ser. No. 763,145 is similar to both 3,994,764 and Ser. No. 705,333. Instead of thermoplastic non-reactive polyurethane, this application employs as non-reactive elastomers in the adhesive composition rubbery polymers and copolymers derived from diolefins such as butadiene-1,3; isoprene; 2-3-dimethylbutadiene-1,3; 2-methyl pentadiene-1,3; 2-methyl-3-butyl butadiene-1, 3; 2,3-diethyl butadiene. The rubbery material may consist entirely of a natural rubber or a synthetic rubber diolefin, i.e. a homopolymer, although the diolefin rubbery polymers usually contain from about 5% to 40% of an olefinic modifying comonomer, such as those specified above, e.g. styrene, acrylonitrile, methyl methacrylate. Thus, such rubbers as styrene butadiene, butadiene-styrene-acrylonitrile, neoprene rubber, butyl rubber, silicone rubbers preferably other than dimethylsiloxanes, polysulfide rubber, polyacrylate rubber, pyridine butadiene rubbers, chlorosulfonated polyethylene, etc., may be used. The styrene-butadiene and acrylonitrilebutadiene rubbers are now generally referred to as SBR and NBR rubbers. Additionally, grafted rubbers may constitute the elastomeric polymer of the adhesive system. Such rubbers are prepared by grafting vinyl monomers, e.g. those mentioned above, onto the rubber polymer backbone by methods known in the art, e.g. emulsion polymerization. In addition to the rubbery material exemplified by the aforesaid, other elastomers which are non-reactive in the sense used herein may be employed; such as for example, poly ethers of epichlorohydrin. The elastomers employed do not react to any notable degree with any component of the adhesive composition. Both a two part adhesive formulation as in U.S. Pat. No. 3,994,764 and a one liquid formulation employing pressure rupturable microspheres encapsulating a tertiary amine activator as in Ser. No. 705,333 is shown in each of these prior adhesive compositions. Improved heat resistance above temperatures of 150° C. may be obtained by incorporating up to 20% (preferably 6-12%) of an epoxide resin not reactive with any of the other components of the adhesive formulation.
No preliminary preparation of the pipe surfaces is required in employing these adhesives. This is in marked contrast to the current methods employed with epoxy adhesives which require degreasing, sanding to remove any glossy plastic and roughen the surface, and the use of gloves to prevent surface contamination.
In the two part application, employing the adhesives of Ser. No. 763,145, the adhesive solution part is applied to one end of a pipe section and the activator is applied to a mating end of a second pipe section. Both sections are then brought together to form the joint, at which time the adhesive starts to cure. The joint sets, i.e. not movable by hand, in about 3 to 7 minutes.
In employing the one-liquid adhesives of Ser. No. 763,145, having rupturable microspheres containing the activator two alternate methods may be used. In one, the adhesives are applied to one end of a pipe section. A mating pipe section having a corresponding end adapted to put into the first pipe end is then joined to the first pipe section. The pressure generated by the pipe ends being fitted together ruptures the microspheres, releasing the activator and causes the adhesive to set. If desired, both pipe ends may be coated with the one-liquid adhesives. In the other method the microspheres are ruptured in the adhesive composition, as by passing the mixture through a gear pump. The adhesive is then applied to one or both ends of the pipe sections which are then joined together.
The cure takes place at room temperature and no "icicles" are formed resulting in a completely open pipe interior. Polyester or epoxy fiberglass pipes, joined with the adhesives described may be employed at temperature as high as 300° F. (148.9° C.).
The method set forth can be used to join a pair of diverse pipes made of polyester fiberglass, epoxy-fiberglass, polyvinylchloride, black iron, galvanized iron, copper, stainless steel, etc. It can be used for joining pipes to reaction vessels or process equipment. Leaks can be sealed readily by use of the adhesive and cured at room temperature.
EXAMPLE
Two sections of polyester-fiberglass reinforced pipe were joined together employing the adhesive of example 1 of Ser. No. 763,145.
33 grams of a high acrylonitrile/butadiene rubber, Hycar 1431, a commercially available product of B. F. Goodrich Co., Inc., was dissolved in a mixture of 33 grams of acrylic acid and 34 grams of methyl methacrylate. Thereafter 5 grams of benzoyl peroxide and 0.1 gram of hydroquinone were dissolved in the solution.
The foregoing solution was applied at a 10 mil thickness to one end of a pipe section. Dimethyl aniline was applied to a mating end portion of the other pipe specimen in an amount to form a layer of 0.05 mil thick. The two pipe sections were then joined with a light pressure by fitting one mating surface into the other to form the joint. The bond developed at room temperature withstood water immersion for 8 months without loss of strength. No decrease in the inside diameter of the pipe due to any adhesive exceeding or "icicle" formation was observed.
A number of pipes were treated and joined in this manner. Curing started when the pipe sections were brought together. The joint became "set" (not movable by hand) in 3 to 7 minutes at room temperature. Bond values were about 1100 psi average in shear tested at 0.2 inches per minute. Bond of 1400 psi were obtained with rupture of the plastic pipe.
In addition for use under elevated temperatures, the method described may be employed to join pipes which are to be exposed to other adverse environmental conditions such as solvents or strong caustic or acids. Although in the long run the adhesives may be affected by these substances, only a small exterior adhesive surface comes into contact with them, and the bulk of the adhesive is unaffected over a considerable period. Thus, the pipe junctions may be employed in these environments for substantial time periods before being replaced. | Pipe sections of polyester fiberglass, epoxy fiberglass or of other diverse or same materials are adhesively joined together or to reaction vessels by applying to one mating surface an adhesive composition comprising a solution of non-reactive elastomer as for example, butadieneacrylonitrile rubber dissolved in a mixture of polymerizable acrylic monomers and acrylic acid monomer such as methyl methacrylate and acrylic acid, containing a polymerization catalyst such as benzoyl peroxide, and applying to the other mating surface a tertiary amine activator, bringing the mating surfaces together and allowing the adhesive to cure to a set. In another embodiment the tertiary amine is encapsulated in a rupturable microsphere and dispersed in the adhesive composition. The microspheres may be ruptured before or after the adhesive is applied. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application 61/546,334, filed on Oct. 12, 2011, entitled “SYSTEM AND METHOD FOR A REMOTE SERVICES SYSTEM”, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to remote servicing; and more particularly to a system and method of delivering remote servicing, wherein the use of photographic images of a device being serviced are electronically transmitted to the location of the service representative which would then be reviewed to determine if a service tech needs to make a service visit.
DESCRIPTION OF BACKGROUND
[0003] One way to provide support and repair of computers, electronic device and the like, of consumers is through on-site services. On-site support services may be delivered via technical labor visiting the location of the malfunctioning device to solve problems. Information about the malfunctioning device may be acquired in the form of emails, online chat and phone, or remotely attaching to the devices and providing direct support. The delivery of labor to the location of the malfunctioning device is immensely inefficient and expensive because of travel time and because the nature of the work is indeterminate. Resolving a problem in the location of the malfunctioning device may require a short visit or a long visit, and may not be known until the technical labor is on-site. As a result, in service providers typically schedule the availability of technicians with slack time to account for the indeterminate nature of the work as well as travel.
[0004] The use of slack time to account for the nature of the work is wasteful and increases the amount of additional labor that may needed as demand increases. Not using slack time or using less slack time may decrease the availability of technicians to handle the next customer. This may result in abandoned customers, decreased response time and decrease customer satisfaction. The nature of the on-site work may be broad in technical scope as it may involve many different devices and software. This makes it very difficult if not nearly impossible for a service provider to find someone who is able to address the full spectrum of work on-site. Often times follow-up visits must be scheduled to complete work which could not be resolved by the dispatched technician. This results in longer delays in resolving the issue at home decreasing the customer's satisfaction with the support experience.
[0005] On the other hand, purely remote service cannot resolve problems when access to the computer or other devices is constrained due to malfunction, network issues or connections. Further there may be a hardware issue which requires a physical presence to repair or replace in order to fix. Therefore, it is challenging to provide an optimum customer service experience by using either onsite support or remote customer support.
SUMMARY OF THE INVENTION
[0006] Embodiments of the present invention provide a system and method for delivering remote servicing services, wherein the use of digital images of a device being serviced are electronically transmitted to the location of the service representative which would then be reviewed to determine if a service tech needs to make a service visit.
[0007] An exemplary embodiment includes a method for delivering remote servicing embodied in a computer program product for execution on an instruction processing system. The computer system comprises a tangible storage medium readable by computer system and storing instructions for execution by the instruction processing system for performing the method. The method comprises receiving a phone call from a customer and receiving a digital image of a device being serviced by a service representative. The method further includes displaying the digital image of the device being serviced on a monitor to the service representative, and determining if a service tech needs to make a service visit.
[0008] Another exemplary embodiment includes a system for delivering remote servicing on a computer system. Briefly described in terms of architecture, one embodiment of the system, among others, is implemented as follows: The system includes a tangible storage medium readable by the computer system and storing instructions for execution by the computer system. The system further includes a means for receiving a phone call from a customer, and a means for receiving a digital image of a device being serviced by a service representative. The system further includes a means for displaying the digital image of the device being serviced on a monitor to the service representative, and a means for determining if a service tech needs to make a service visit.
[0009] A further exemplary embodiment includes a computer program product for providing vehicle valuation management services on a computer system. The computer program product includes a tangible storage medium readable by a computer system and storing instructions or execution by the computer system for performing a method. The method comprises receiving a phone call from a customer and receiving a digital image of a device being serviced by a service representative. The method further includes displaying the digital image of the device being serviced on a monitor to the service representative, and determining if a service tech needs to make a service visit
[0010] These and other aspects, features and advantages of the invention will be understood with reference to the drawing figure and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawing and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] 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 objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0012] FIG. 1 is a block diagram illustrating an example of the network environment for the remote servicing services of the present invention.
[0013] FIG. 2A is a block diagram illustrating an example of a server utilizing the remote servicing services of the present invention, as shown in FIG. 1 .
[0014] FIG. 2B is a block diagram illustrating an example of a remote device utilizing the remote device system, as shown in FIG. 1 .
[0015] FIG. 3A is a flow chart illustrating an example of the operation of the remote servicing system for the host of the present invention utilized by the server, as shown in FIG. 2A .
[0016] FIG. 3B is a flow chart illustrating an example of the operation of the remote servicing system for the remote device of the present invention, as shown in FIG. 2B .
[0017] FIG. 4A is a flow chart illustrating an example of the operation of the remote service call process of the present invention utilized by the server, as shown in FIGS. 2A & 3A .
[0018] FIG. 4B is a flow chart illustrating an example of the operation of the remote service call app for the remote device of the present invention, as shown in FIG. 2B .
[0019] FIG. 5 is a flow chart illustrating an example of the operation of the locate process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 4 A.
[0020] FIG. 6 is a flow chart illustrating an example of the operation of select service process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 4 A.
[0021] FIG. 7 is a flow chart illustrating an example of the operation of billing process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 4 A.
[0022] FIG. 8 is a flow chart illustrating an example of the operation of sales/service process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 4 A.
[0023] FIG. 9 is a flow chart illustrating an example of the operation of remote interaction process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 4 A.
[0024] FIG. 10A is a flow chart illustrating an example of the operation of the policy process the host of the present invention utilized by the server, as shown in FIGS. 2A & 3A .
[0025] FIG. 10B is a flow chart illustrating an example of the operation of the policy app for the remote device of the present invention, as shown in FIG. 2B .
[0026] FIG. 11 is a flow chart illustrating an example of the operation of the quote process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 10 A.
[0027] FIG. 12 is a flow chart illustrating an example of the operation of admin process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 10 A.
[0028] FIG. 13 is a flow chart illustrating an example of the operation of asset/claim process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 10 A.
[0029] FIG. 14 is a flow chart illustrating an example of the operation of agent interaction process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A , 3 A & 10 A.
[0030] FIG. 15 is a flow chart illustrating an example of the operation of the intelligent routing process that is utilized in the remote servicing system of the present invention, as shown in FIGS. 2A & 8A .
[0031] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention.
[0033] The invention described hereafter is applicable on all remote devices connected to a server hosting the remote servicing system and method of the present invention. While described below with respect to a single computer, the system and method for a webpage build system is typically implemented in a networked computing environment in which a number of computing devices communicate over a local area network (LAN), over a wide area network (WAN), or over a combination of both LAN and WAN.
[0034] In one embodiment, a user downloads application from Apple app store, Android Market, Amazon App store, direct email download, or from hosted web site to their mobile device, tablet, or computer. The application is opened by pressing on the touch screen on the device or clicked on with input device. Upon first launch of the application the application check to see what type of device it has been installed on and prompts user for geolocation access if device contains geolocation device such as a GPS receiver. If the GPS receiver is available and finds a valid location it passes on the information via cellular wi-fi or communications network (further referred to as network) to a geolocation server which cross checks the location to available services in the area. If the GPS receiver is unavailable or user opts to not allow this feature, the user is prompted via the device with a visual prompt on to enter the zip code of their service address. The zip code information is sent to a service cloud server via the network hosting a database of zip codes and service providers.
[0035] The list of services available in the area is passed on to the user in a list form of selectable icons or words of service providers. The user selects the icon or name of the provider in which they wish to connect and that selection is sent to the service cloud server. If the provider the user selects does not subscribe to the service, the user is prompted with a message requesting the service provider add support via the application. The user is presented with a preselected message requesting their service provider to add support. The user is also then presented with companies that do utilize the application in their area for subscribing to a new service.
[0036] The service cloud server returns a response to the application to prompt the user to enter the identification number of the account. If the user is unable to provide the account ID number a look-up service is available to utilize the account owners SSN number and birthday. The users IP address is also an authentication option if the subscriber is connected via WIFI. The service cloud server sends a request to a local server to provide a list array of subscribed or available services. The user chooses from the list and assuming an available, but not subscribed service is chosen they are routed to a sales lobby. The sales screen allows them to add or delete services on their account.
[0037] The user selects a service in which they need help with by pressing the word or icon of the service. The server checks to see if the account is current simultaneously while the user is presented the options, if an account is not current the user is routed to a billing screen. The user is able to make a payment to restore services and after the payment has been processed the user receives a message that the services will be restored. An order message is transmitted to the service provider to restore services. The order message could be machine to machine and restore the services automatically or could be a manual process.
[0038] If the account is current, the user is connected to a virtual lobby and routed to wait for support personnel to assist them. Messages to the lobby are available that indicate known physical issues in the service territory such as local or global outages. Messages for sales are also available to upgrade services such as adding premium channels.
[0039] The user is able to schedule an appointment for in real time collaboration with the sales representative identifying the appropriate equipment to interact with the users equipment including cables, remotes. The sales representative is able to view the equipment and identify and up sell services such as wireless connectivity. The account representative engages the user in a virtual private room and assists them by utilizing the camera on the device to visually support the needs of the user. The user has the ability to control the audio by activating the audio and the video by activating or disabling the video and controlling the light (if available) of the device via on screen controls.
[0040] The support representative utilizes a desktop application to connect into the lobby and private room via user name and password on the video sharing server. The support representative communicates to the user via the speaker of the device or a text field of a chat session based on the preference of the user. The video sharing server records the audio and video of the issue and is available for review to the field technician who is dispatched to the site to repair an issue that the user is unable to repair. Users can also initiate a support session for self installation or continuance of a session via a key code. The key code has been created by the sales or service technician and assigned to that order. This session information is initiated over a phone dialog or text chat support session where the subscriber has contacted the service provider for support or sales. The key code is generated for support for a self installation session and is embedded in a qr code or manually entered. Users log in to the application using the key code and are directly connected to a lobby to be met by a support representative.
[0041] In an alternative embodiment, the policy holder initiates application via mobile device with camera. User agrees that the content will be recorded. Policy holder enters account number or identification login or key code. Identification number is sent to server and checked for status of policy. The server returns a response asking the user to select whether to use the camera for a new quote or for a claim. The Policy holder then uses the device to provide video that is recorded by the remote server with the assistance of the Insurance Representative prompting for detail. The user is able to enable the flashlight while recording the information.
[0042] In another alternative embodiment, a rear view camera and light is utilized both during the interaction for troubleshooting and for policy adjustment. The software on the host is also capable of controlling the light during interaction for troubleshooting and for policy adjustment.
[0043] Referring now to the drawings, in which like numerals illustrate like elements throughout the several views. FIG. 1 illustrates an example of the basic components of a system 10 using the remote servicing system used in connection with the preferred embodiment of the present invention. The system 10 includes a server 11 and the remote devices 15 , 17 - 19 or 21 that utilize the remote servicing system of the present invention.
[0044] Each remote device 15 , 17 - 19 has applications and can have a local database 16 . Server 11 contains applications, and a database 12 that can be accessed by remote device 15 , 17 - 19 via connections 14 (A-C), respectively, over network 13 . The server 11 runs administrative software for a computer network and controls access to itself and database 12 . The remote device 15 , 17 - 19 may access the database 12 over a network 13 , such as but not limited to: the Internet, a local area network (LAN), a wide area network (WAN), via a telephone line using a modem (POTS), Bluetooth, WiFi, cellular, optical, satellite, RF, Ethernet, magnetic induction, coax, RS-485, the like or other like networks. The server 11 may also be connected to the local area network (LAN) within an organization (i.e. a university or industrial complex).
[0045] The remote device 15 , 17 - 19 may each be located at remote sites. Remote device 15 , 17 - 19 include but are not limited to, PCs, workstations, laptops, handheld computer, pocket PCs, PDAs, pagers, WAP devices, non-WAP devices, cell phones, palm devices, printing devices and the like. Included with each remote device 15 , 17 - 19 is an ability to obtain images of the client. In the remote device 15 , there is a special camera for capturing images of devices to be serviced. In remote devices 17 and 18 , they are maybe integrated cameras for acquiring images of the devices to be serviced or the ability to download photographs of devices to be serviced in a digital form.
[0046] Thus, when a user at one of the remote devices 15 , 17 - 19 desires to access remote servicing services status from the database 12 at the server 11 , the remote device 15 , 17 - 19 communicates over the network 13 , to access the server 11 and database 12 .
[0047] Third party vendors computer systems 21 and databases 22 can be accessed by the remote servicing system 100 on server 11 in order to access product offerings and ordered products. Data that is obtained from third party vendors computer system 21 and database 22 can be stored on server 11 and database 12 in order to provide later access to the user on remote devices 15 , 17 - 19 . It is also contemplated that for certain types of data that the remote devices 15 , 17 - 19 can access the third party vendors computer systems 21 and database 22 directly using the network 13 .
[0048] Illustrated in FIG. 2A is a block diagram demonstrating an example of server 11 , as shown in FIG. 1 , utilizing the remote servicing system 100 of the present invention. Server 11 includes, but is not limited to, PCs, workstations, laptops, PDAs, palm devices and the like. Illustrated in FIG. 2B is an example demonstrating a remote devices 15 , 17 - 19 utilizing the remote servicing app 500 of the present invention. The processing components of the third party vendors computer systems 21 are similar to that of the description for the server 11 ( FIG. 2A ).
[0049] Generally, in terms of hardware architecture, as shown in FIG. 2A , the server 11 include a processor 41 , memory 42 , and one or more input and/or output (I/O) devices (or peripherals) that are communicatively coupled via a local interface 43 . The local interface 43 can be, for example but not limited to, one or more buses or other wired or wireless connections, as is known in the art. The local interface 43 may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers, to enable communications. Further, the local interface 43 may include address, control, and/or data connections to enable appropriate communications among the aforementioned components.
[0050] The processor 41 is a hardware device for executing software that can be stored in memory 42 . The processor 41 can be virtually any custom made or commercially available processor, a central processing unit (CPU), data signal processor (DSP) or an auxiliary processor among several processors associated with the server 11 , and a semiconductor based microprocessor (in the form of a microchip) or a macroprocessor. Examples of suitable commercially available microprocessors are as follows: an 80×86 or Pentium series microprocessor from Intel Corporation, U.S.A., a PowerPC microprocessor from IBM, U.S.A., a Sparc microprocessor from Sun Microsystems, Inc, a PA-RISC series microprocessor from Hewlett-Packard Company, U.S.A., or a 68xxx series microprocessor from Motorola Corporation, U.S.A. or an ARMvX microprocessor licensed from ARM Holdings, U.K
[0051] The memory 42 can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as dynamic random access memory (DRAM), static random access memory (SRAM), etc.)) and nonvolatile memory elements (e.g., ROM, erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), programmable read only memory (PROM), tape, compact disc read only memory (CD-ROM), disk, diskette, cartridge, cassette or the like, etc.). Moreover, the memory 42 may incorporate electronic, magnetic, optical, and/or other types of storage media. Note that the memory 42 can have a distributed architecture, where various components are situated remote from one another, but can be accessed by the processor 41 .
[0052] The software in memory 42 may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. In the example illustrated in FIG. 2A , the software in the memory 42 includes a suitable operating system (O/S) 49 and the remote servicing system 100 of the present invention. As illustrated, the remote servicing system 100 of the present invention comprises numerous functional components including, but not limited to, the remote service call process 120 , and policy process 240 . The remote service call process 120 further includes, but is not limited to, the locate process 140 , select service process 160 , billing process 180 , sales/service process 200 and remote interaction process 220 . The policy process 240 further includes, but is not limited to a quote process 260 , admin process 280 , asset/claim process 300 and agent interaction process 320 .
[0053] A non-exhaustive list of examples of suitable commercially available operating systems 49 is as follows (a) a Windows operating system available from Microsoft Corporation; (b) a Netware operating system available from Novell, Inc.; (c) a Macintosh operating system available from Apple Computer, Inc.; (d) a UNIX operating system, which is available for purchase from many vendors, such as the Hewlett-Packard Company, Sun Microsystems, Inc., and AT&T Corporation; (e) a LINUX operating system, which is freeware that is readily available on the Internet; (f) a run time Vxworks operating system from WindRiver Systems, Inc.; or (g) an appliance-based operating system, such as that implemented in handheld computers or personal data assistants (PDAs) (e.g., Symbian OS available from Symbian, Inc., PalmOS available from Palm Computing, Inc., and Windows CE available from Microsoft Corporation).
[0054] The operating system 49 essentially controls the execution of other computer programs, such as the remote servicing system 100 , and provides scheduling, input-output control, file and data management, memory management, and communication control and related services. However, it is contemplated by the inventors that the remote servicing system 100 of the present invention is applicable on all other commercially available operating systems.
[0055] The remote servicing system 100 may be a source program, executable program (object code), script, or any other entity comprising a set of instructions to be performed. When a source program, then the program is usually translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory 42 , so as to operate properly in connection with the O/S 49 . Furthermore, the remote servicing system 100 can be written as (a) an object oriented programming language, which has classes of data and methods, or (b) a procedure programming language, which has routines, subroutines, and/or functions, for example but not limited to, C, C++, C#, Pascal, BASIC, API calls, HTML, XHTML, XML, ASP scripts, FORTRAN, COBOL, Perl, Java, ADA, .NET, and the like.
[0056] The I/O devices may include input devices, for example but not limited to, a mouse 44 , keyboard 45 , scanner (not shown), microphone (not shown), etc. Furthermore, the I/O devices may also include output devices, for example but not limited to, a printer (not shown), display 46 , etc. Finally, the I/O devices may further include devices that communicate both inputs and outputs, for instance but not limited to, a NIC or modulator/demodulator 47 (for accessing remote devices, other files, devices, systems, or a network), a radio frequency (RF) or other transceiver (not shown), a telephonic interface (not shown), a bridge (not shown), a router (not shown), etc.
[0057] If the server 11 is a PC, workstation, intelligent device or the like, the software in the memory 42 may further include a basic input output system (BIOS) (omitted for simplicity). The BIOS is a set of essential software routines that initialize and test hardware at startup, start the O/S 49 , and support the transfer of data among the hardware devices. The BIOS is stored in some type of read-only-memory, such as ROM, PROM, EPROM, EEPROM or the like, so that the BIOS can be executed when the server 11 is activated.
[0058] When the server 11 is in operation, the processor 41 is configured to execute software stored within the memory 42 , to communicate data to and from the memory 42 , and generally to control operations of the server 11 are pursuant to the software. The remote servicing system 100 and the O/S 49 are read, in whole or in part, by the processor 41 , perhaps buffered within the processor 41 , and then executed.
[0059] When the remote servicing system 100 is implemented in software, as is shown in FIG. 2A , it should be noted that the remote servicing system 100 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.
[0060] 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, propagation medium, 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.
[0061] More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic or optical), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc memory (CDROM, CD R/W) (optical). Note that the computer-readable medium could even be paper or another suitable medium, upon which the program is printed or punched (as in paper tape, punched cards, etc.), as the program can be electronically captured, via for instance optical scanning 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.
[0062] In an alternative embodiment, where the remote servicing system 100 is implemented in hardware, the remote servicing system 100 can be implemented with any one or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
[0063] Illustrated in FIG. 2B is a block diagram demonstrating an example of functional elements in the remote device 15 , 17 - 19 , that enables access to the remote servicing app 500 of the present invention, as shown in FIG. 2A . The remote devices 15 , 17 - 19 provides access to the remote servicing system 100 of the present invention on server 11 and database 12 using the remote servicing app 500 , including for example, but not limited to an Internet browser. The information accessed in server 11 and database 12 can be provided in the number of different forms including but not limited to ASCII data, WEB page data (i.e. HTML), XML or other type of formatted data.
[0064] Included with each remote device 15 , 17 - 19 is an ability to obtain images of the client. In the remote device 15 , there is a camera 58 for capturing images of client 20 . In remote devices 17 and 18 , they are maybe integrated cameras 58 for acquiring images of the client or the ability to download photographs of client 20 in a digital form.
[0065] As illustrated, the remote device 15 , 17 - 19 and 21 are similar to the description of the components for server 11 described with regard to FIG. 2A . Hereinafter, the remote devices 15 , 17 - 19 that will be referred to as remote devices 15 for the sake of brevity.
[0066] FIG. 3A is a flow chart illustrating an example of the operation of the remote servicing system 100 of the present invention utilized by the server 11 , as shown in FIGS. 1 and 2A . The remote servicing system 100 shows the combined embodiments of the service call process and the policy process. It is understood that normally only the service call process or the policy process would be active in the remote servicing system 100 . However, for illustration purposes, the remote servicing system 100 shows both of the embodiments of the service call process and policy process together.
[0067] The remote servicing system 100 of the present invention provides a support representative the ability to utilize a desktop application to connect into the lobby and private room via user name and password on the video sharing server. The support representative communicates to the user via the speaker of the device or a text field of a chat session based on the preference of the user. The video sharing server records the audio and video of the issue and is available for review to the field technician who is dispatched to the site to repair an issue that the user is unable to repair.
[0068] First at step 101 , the remote servicing system 100 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the remote servicing system 100 .
[0069] At step 102 , the remote servicing system 100 waits to receive an action request. After receiving an action request at step 102 , the remote service system 100 determines if the action to be performed is a remote service call at step 103 . If it is determined in step one of three that the action to be performed is a remote service call, then the remote servicing system 100 performs the service call process at step 104 . This service call process is here and find it further detail with regard FIG. 4A . After performing the service call process, the remote servicing system 100 returns to wait to receive an action request at step 102 .
[0070] However, if it is determined at step 103 that the action request is not a remote service call, then the remote servicing system 100 determines if the action request is a policy action at step 105 . If it is determined at step 105 that the action request is a policy action, then the remote servicing system 100 performs the policy process at step 106 . The policy process herein defined in further detail with regard FIG. 10A . After performing the policy process, the remote servicing system 100 returns to wait to receive an action request at step 102 .
[0071] However, if it is determined at step 105 that the action request is not a policy action, then the remote servicing system 100 determines if the action request is a intelligent routing action at step 111 . If it is determined at step 111 that the action request is a intelligent routing action, then the remote servicing system 100 performs the intelligent routing process at step 112 . After performing the intelligent routing process, the remote servicing system 100 returns to wait to receive an action request at step 102 .
[0072] However, if it is determined at step 111 that the action request is not a intelligent routing, then the remote servicing system 100 determines if the action request is a miscellaneous action at step 113 . If it is determined at step 113 that the action request is a miscellaneous action, then the remote servicing system 100 performs the miscellaneous process at step 114 . After performing the miscellaneous process, the remote servicing system 100 returns to wait to receive an action request at step 102 .
[0073] However, if it is determined at step 113 that the action request is not a miscellaneous action, then the remote servicing system 100 determines if the action request is an exit action at step 115 . If it is determined at step 115 that the action request is an exit action, then the remote servicing system 100 exits at step 119 .
[0074] FIG. 3B is a flow chart illustrating an example of the operation of the remote servicing app 500 of the present invention utilized by the remote device 15 , as shown in FIGS. 1 and 2B . The remote servicing app 500 shows the combined embodiments of the service call app and the policy app. It is understood that normally only the service call app or the policy app would be active in the remote servicing app 500 . However, for illustration purposes, the remote servicing system 100 shows both of the embodiments of the service call app and policy app together.
[0075] The remote servicing app 500 of the present invention provides a user the ability to utilize a remote device 15 to connect into the lobby and private room via user name and password on the video sharing server. The user support representative communicates to the support representative via the speaker of the remote device 15 or a text field of a chat session on the remote device 15 , based on the preference of the user. The video sharing server records the audio and video of the issue and is available for review to the field technician who is dispatched to the site to repair an issue that the user is unable to repair.
[0076] First at step 501 , the remote servicing app 500 is initialized. This initialization includes the startup routines and apps embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the remote servicing app 500 .
[0077] At step 502 , the remote servicing app 500 waits to receive a action request. After receiving an action request at step 502 , the remote servicing app 500 determines if the action to be performed is a remote service call at step 503 . If it is determined in step one of three that the action to be performed is a remote service call, then the remote servicing app 500 performs the service call app at step 504 . This service call app is here and find it further detail with regard FIG. 4B . After performing the service call app, the remote servicing app 500 returns to wait to receive a user's input of an action request at step 502 .
[0078] However, if it is determined at step 503 that the action request is not a remote service call, then the remote servicing app 500 determines if the action request is a policy action at step 505 . If it is determined at step 505 that the action request is a policy action, then the remote servicing app 500 performs the policy app at step 506 . The policy app herein defined in further detail with regard FIG. 10B . After performing the policy app, the remote servicing app 500 returns to wait to receive an action request at step 502 .
[0079] However, if it is determined at step 505 that the action request is not a policy action, then the remote servicing app 500 determines if the action request is a miscellaneous action at step 511 . If it is determined at step 511 that the action request is a miscellaneous action, then the remote servicing app 500 performs the miscellaneous app at step 512 . After performing the miscellaneous app, the remote servicing app 500 returns to wait to receive an action request at step 502 .
[0080] However, if it is determined at step 511 that the action request is not a miscellaneous action, then the remote servicing app 500 determines if the action request is an exit action at step 513 . If it is determined at step 513 that the action request is an exit action, then the remote servicing app 500 experts at step 519 .
[0081] FIG. 4A is a flow chart illustrating an example of the operation of the remote service call process 120 of the present invention utilized by the server 11 , as shown in FIGS. 2A & 3A . First, the remote service call process 120 waits for a user to initiate the application. Next, a welcome screen explaining the services provided is displayed. The remote service call process 120 then checks to see if the user input a key code. If the key code is input, then it is validated. If the key code is valid, then the customer is linked to a private session and the remote service call process 120 then skips to perform the remote interaction process below. However, if the key code is not input or is invalid, then the locate process is performed to determine the location of the service call. Next, the user selects the remote service to be performed from a list of service providers. At this time, the remote service call process checks to make sure that the users account is current. If the user's account is current, then the remote service call process 120 skips to perform the sales/service process. However, it is determined that the account is not current, and the remote service call process 120 performs the billing process in order to place the user's account into a current status. Next, the sales/service process is then performed. Next it is determined that the user has selected a service to be performed. If not, then the remote service call process 120 skips to see if there's more interaction with this user. However, it is determined that the user has selected a service to be performed, then the remote service call process 120 performs a remote interaction process. Last it is determined if there's more interaction with this user. If it is determined that there is more interaction with this user, then the remote service call process 120 returns to step one to wait for the user to initiate the application. However, if there is no more interaction with the user, the remote service call process then exits.
[0082] First at step 121 , the remote service call process 120 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the remote service call process 120 .
[0083] At step 122 , the remote service call process 120 waits to receive an action request. After receiving an action request at step 122 , the remote service call process 120 displays a welcome screen explaining the services provided, at step 123 . The remote service call process 120 then checks to see if the user input a key code at step 124 . If the key code is input, then it is validated, at step 125 . If the key code is valid, then the customer is linked to a private session at step 126 , and the remote service call process 120 then skips to step 137 to perform the remote interaction process.
[0084] However, if it is determined at step 124 that the key code is not input or it is determined at step 125 that the key code is invalid, then the remote service call process 120 performs the locate process at step 131 . The locate process determines the location of the service call and is herein defined in further detail with regard FIG. 5 . Next, the remote service call process 120 performs select service process at step 132 . The select service process enables the user to select the remote service to be performed from a list of service providers. The select service process is herein defined in further detail with regard FIG. 6 .
[0085] At step 133 , the remote service call process 120 checks to make sure that the users account is current. If the user's account is current, then the remote service call process 120 skips to step 135 to perform the sales/service process. However, if it is determined that the account is not current, then the remote service call process 120 performs the billing process in order to place the user's account into a current status at step 134 . The billing process enables the user to make their account. The billing process is herein defined for the detail with regard to FIG. 7 . Next, the remote service call process 120 performs the sales/service process, at step 135 . The sales/service process enables the user to purchase a service or implement a service. The sales/service process herein defined in further detail with regard to FIG. 8 .
[0086] Next the remote service call process 120 determines if the user has selected a service to be performed at step 136 . If the remote service call process 120 determines that a user has not selected a service to be performed at step 135 , then the remote service call process 120 skips to step 138 to see if there's more interaction with this user. However, if it is determined that the user has selected a service to be performed at step 135 , then the remote service call process 120 performs a remote interaction process at step 137 . The remote interaction process enables the user to have remote interaction with a trained representative to assist the user with a service.
[0087] At step 138 , it is determined if there's more interaction with this user. If it is determined that there is more interaction with this user, then the remote service call process 120 returns to step 122 to wait for the user to initiate the application. However, if it is determined that there is no more interaction with the user, the remote service call process 120 then exits at step 139 .
[0088] FIG. 4B is a flow chart illustrating an example of the operation of the remote service call app 600 for the remote device 15 of the present invention, as shown in FIG. 2B . the remote service call app 600 prompts a user to indicate the location of the service call, enables a user to display a list of service providers in and around that location and enables the user to select a service from the selective service provider.
[0089] First at step 601 , the remote service call app 600 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the remote device 15 . The initialization also includes the establishment of data values for particular data structures utilized in the remote service call app 600 .
[0090] The remote service call app 600 then waits to receive an action request at step 602 . Next, a welcome screen explaining the services provided is displayed in the user is prompted to initiate an application from the icon displayed a welcome screen. To initiate some applications, the user must enter a valid key code when initiating the application from an icon at step 603 . The remote service call app 600 then prompts the user to input a key code if required. At step 604 , the remote service call app 600 prompts the user to enter a location for the service call in order to determine a location of the server 11 to provide services. Next come the remote service call app 600 accesses the location server 11 to display a list of the service providers to provide by the requested service call, at step 605 .
[0091] At step 606 , the user is prompted to choose a provider from the list displayed at step 605 . After the user selects the provider to perform the service call at step 606 , the remote service call app 600 connects to the MSO (i.e. Multiple Service Operator) server 11 to display a list of services provided by that service provider. MSO's include but are not limited to, cable or telecommunications service providers. Next, the user selects a service to be performed, at step 612 . At step 613 , and user uploads the video/pictures to the video traffic server 11 . This is how the user is able to disclose the actual state of apparatus/device needing service.
[0092] Last, it is determined if there is more interaction with this user. If it is determined that there is more interaction with this user, then the remote service call app 600 returns to step 602 to wait for the user to initiate the action request. However, if there is no more interaction with the user, the remote service call app 600 then exits.
[0093] FIG. 5 is a flow chart illustrating an example of the operation of the locate process 140 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 4 A. locate process 140 utilizes a variety of different techniques to determine the location of where the service is to be provided. The different techniques to find the location of where the service is to be provided includes, but is not limited to GPS, zip code, cellular triangulation, input from the user and the like.
[0094] First at step 141 , the locate process 140 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the locate process 140 .
[0095] At step 142 , the locate process 140 receive an action request for geolocation allowance. Geolocation allowance enables the remote servicing system 100 to find the boundaries or distances from the location where the service to be provided and the service providers After receiving an action request at step 122 , the remote service call process 120 displays a welcome screen explaining the services provided, at step 123 .
[0096] At step 143 , the locate process 140 determines if GPS is to be utilized for location determination. It is determined at step 143 that GPS is not to be utilized, then the locate process 140 then skips the step 151 . However, if it is determined at step 143 that GPS is to be utilized to determine a location of where the services to be provided, then the locate process 140 then determines if the hardware to be service is returning a GPS fix at step 144 . If it is determined at step 144 that the hardware did return a GPS location, then the locate process 140 then skips to step 146 . However, it is determined at step 144 that the hardware did not return a GPS fix, then the hardware times out of GPS at step 145 and proceeds to step 151 .
[0097] At step 146 , the locate process 140 uses the GPS fix transmitted to a geolocation API (i.e. application programming interface). At step 147 , the GPS data is converted into a service area to determine a possible MSO. The locate process 140 then skips since 154 .
[0098] At step 151 , the locate process prompts the user for MS though ZIP code. After receiving the ZIP code data from the user, the ZIP code data is communicated to the server 11 at step 152 . The server 11 matches the ZIP code received from the user against the server master list of possible MSOs that provide service at step 153 .
[0099] At step 154 , the server 11 transmits the list of possible MSOs to the user to enable the user to select the MSO of choice.
[0100] The locate process 140 then exits at step 159 .
[0101] FIG. 6 is a flow chart illustrating an example of the operation of select service process 160 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 4 A. The select service process a 160 enables a user to select an MSO to provide a particular service.
[0102] First at step 161 , the select service process 160 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the select service process 160 .
[0103] At step 162 , the select service process 160 displays a list of MSOs to a user on the display screen. At step 163 , these select service process 160 enables a user to choose from a list of MSOs and the selection is transmitted to server 11 . Server 11 processes the selection and points to the MSO server to provide the service at step 164 . At step 165 , it is determined if the user is a supporter of the MSO selected. If it is determined at step 165 that the user is a supporter of the MSO selected, then the select service process 160 events gets to step 171 . However, it is determined in step 165 that the MSO selected by the user is not a supported MSO, then these select service process 160 sends a message to request the addition of the provider selected at step 166 . At step 167 , a message is generated and sent to operator of the remote service system 100 (i.e. Thruview LLC) to add the MSO selected at step 163 . At step 168 , the select service process 160 confirms to the user and sales offers to others of the newly added MSO. At step 169 , server 11 transmits the list of possible MSOs to the user and returns to display the list of MSOs at step 162 .
[0104] At step 171 , a login screen is provided to the user. At step 172 , it is determined if the Internet protocol (i.e. IP) address of the user is a valid IP address. If it is determined in step 172 that the IP address is not valid for the user, then a select service process 160 skips to step 174 . However, if it is determined at step 172 that the IP address for the user is verified, then the IP address of the user is cross checked with the Internet service provider (ISP) for authentication. The select service process 160 then skips to step 179 .
[0105] At step 174 , if it is determined at step 172 that the user IP address was not valid, then the user is prompted to enter the account number and phone number of the user's account. At step 175 , the account data is relayed to the MSO server. The MSO server then processes the login information at step 176 .
[0106] The select service process 160 then exits at step 179 .
[0107] FIG. 7 is a flow chart illustrating an example of the operation of billing process 180 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 4 A. the billing process 180 enables a user to display a bill amount due on a display screen, and pay a utilizing a variety of different payment methods. The payment methods include but are not limited to credit card payments, billing to telephone numbers, enabling payment over the phone and the like.
[0108] First at step 181 , the billing process 180 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the billing process 180 .
[0109] At step 182 , the billing process 180 displays an amount due on the display screen. At step 183 , it is determined if the user wishes to pay the bill with a credit card. If it is determined at step 183 that the user does not wish to pay by credit card, then the billing process 180 skips to step 191 . However, it is determined in step 183 that the user does wish to pay the bill by credit card, then the credit card and information is accepted in step 184 . In step 185 , it is determined if the payment amount is accepted. If it is determined in step 185 that the payment was accepted, then the billing process 180 events gets to step 194 . However, it is determined in step 185 that the payment was not accepted, and information about the billing issue is returned to be displayed to the user on a display screen at step 186 . The billing process 180 then returns to step 184 to except new or modified credit card information.
[0110] At step 191 , the phone number of the location being billed is display. At step 192 it is determined if the communication device is a non-phone device (i.e. a tablet, laptop, desktop PC, or the like). If it is determined at step 192 that the communication device being utilized by the user is not a non-phone device, then the billing process 180 skips to step 197 . However, if it is determined that the communication device utilized by the user is a non-phone device, and a video connection is established for payment with billing at step 193 .
[0111] At step 194 , the billing process 180 then determines if the restoration of services is to be established using a DAC plug-in. (i.e. Digital Addressable Controller) DACs are commonly made by Motorola and include a Motorola Cable Software program and server system which control set top boxes. Another type of DAC is a DNCS-Digital Network Control System made by Scientific Atlanta.
[0112] If it is determined at step 194 that the restoration of services is to be accomplished using a DAC plug-in, then the billing process 180 skips to step 196 . However, if it is determined at step 195 that the restoration of services is not to be accomplished using a DAC plug-in, then the billing process 180 sends an e-mail to the local MSO to manually restore the connection to the credit card user war sends a message in application for confirmation that payment was made. The billing process 180 then would skip to step 199 .
[0113] At step 196 , if the restoration of services via a back plug-in is to be performed, and the billing process 180 sends an e-mail to the local MSO to restore the connection of the credit card user or message in application for confirmation that payment has been received. The billing process 180 then would skip to step 199 .
[0114] At step 197 , the phone dialer is initiated to collect the billing. In one embodiment, the phone dialer information is established for the user at time of service activation. In another embodiment, the phone dialer information is determined by location of the user and does service to be provided. At step 198 , a phone call of billing information is made to the local MSO to restore the connection.
[0115] The billing process 180 then exits at step 199 .
[0116] FIG. 8 is a flow chart illustrating an example of the operation of sales/service process 200 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 4 A. The sales/service process 200 enables the user to purchase a remote service or to initiate a remote service.
[0117] First at step 201 , the sales/service process 200 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the sales/service process 200 .
[0118] At step 202 , the sales/service process 200 returns a list to be displayed of possible services to be provided to a user. At step 203 , it is determined if the user chooses to initiate a service. If it is determined at step two and three that the user is not choosing to initiate a service, then the sales/service process 200 skips to step 211 . However, if it is determined at step two of three that the user did select to initiate a service, then that's service selected for initiation is transmitted to the MSO server at step 204 . At step two of five, the user receives a response from the MSO server. At step two is six, the user is connected into the lobby with detailed information and service needs to be performed by the intelligent routing process. The intelligent routing process is herein defined in further detail with regard to FIG. 15 . The sales/service process 200 then skips the step 219 .
[0119] At step 211 , the MSO sales representative acknowledges the user and enters the private chat room. At step to 12, the user allows camera, audio, recording and/or a text chat to be initiated. The MSO sales representative acknowledges the initiation of the camera, audio, recording and or text chat at step 213 . The MSO sales representative then takes the video survey for the services to be performed. The sales representative then uses the camera to capture the ID and equipment to be serviced at step 214 .
[0120] At step 215 , the video, audio and text is transmitted to the appropriate service department to inform this service department of relevant connections and the equipment that will be needed for performing remote service. An order is generated and scheduled at step 216 . Confirmation is given via message to the user on the remote service call app 600 .
[0121] The sales/service process 200 then exits at step 219 .
[0122] FIG. 9 is a flow chart illustrating an example of the operation of remote interaction process 220 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 4 A. The remote interaction process 220 enables the interaction between the user and a remotely located service technician to resolve issues with the equipment to be serviced.
[0123] First at step 221 , the remote interaction process 220 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the remote interaction process 220 .
[0124] At step 222 , the remote interaction process 220 determines if the user allows remote interaction with a remotely located service technician to resolve issues with the equipment to be serviced. If the remote interaction process to 20 determines that the user does not allow remote interactions, and the remote interaction process to 20 then skips to step 239 to exit.
[0125] However, it is determined at step 222 that the user does allow remote interactions, then the user enters a private chat room with a trained representative to assist the user with the service or services at step 223 . While in the remote private chat room, the user or the agent can control the camera, light, audio CD, video feed and text chat. At step 224 , it is determined if the interaction with the trained representative was able to resolve the current issue. If it is determined at step 224 that the current issue was not resolved, then the remote interaction process to 20 then skips the step 231 . However, if it is determined that the current issue was resolved, then the remote interaction process 220 closes the session in recording for future training. At step 226 the user is disconnected from the remote services system. A confirmation message is sent to the user notifying them that the system has logged them out at step 227 . The remote interaction process 220 then skips the step 239 to exit.
[0126] At step 231 , after it is determined at step 224 that the current issue has not been resolved, then the current issue exists for further remedy and the recording session is closed and saved for future review. At step 232 , it is determined if the current issue requires a physical on-site presence of the technician. If it is determined at step 232 that the physical presence of a technician on-site is required, then the remote interaction process 220 sends a confirmation message to the user concerning the appointment time for the technician to provide on-site service. The remote interaction process 220 then skips the step 239 to exit. However, if it is determined at step 232 that the current issue does not require the physical on-site presence of a technician, and the equipment needed to correct the current issue issued to the customer or is made available for pickup with a key code for future login or set up of the equipment being sent.
[0127] The remote interaction process 220 then exits at step 239 .
[0128] FIG. 10A is a flow chart illustrating an example of the operation of the policy process 240 of the present invention utilized by the server 11 , as shown in FIGS. 2A & 3A . The policy process 240 enables a user to acquire a quote for remote support, perform administration changes/modifications to the current policy or perform a claim process on an existing policy.
[0129] First at step 241 , the policy process 240 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the policy process 240 .
[0130] At step 242 , the policy process 240 make sure user to initiate the application from an icon. In a preferred embodiment, the icon is displayed on the remote device 15 for the user to engage. In alternative embodiments there are numerous other ways to initiate the process including, but not limited to requesting a policy action. After receiving a request from the user to perform the policy process, it is then determined if the user input the login key at step 243 . If it is determined at step 243 that the user did not input the login key, then the policy process 240 determines that the user wants to have a quote generated for a service policy. The policy process 240 then skips to step 248 to perform the quote process. The quote process is herein defined in further detailed with regard to FIG. 11 . However, if it is determined at step 243 that the user did input the login key, then it is determined if the login key code was a valid login key at step 244 .
[0131] If it is determined in step 234 that the user did not input a login key code was a valid login key, then the policy process 240 returns to repeat step 243 . However, if it is determined at step 244 that the login key code input was a valid login key, then the policy process 240 determines if the task performed is to be an administrative task, at step 245 . If it is determined in step 245 that the task to be performed is not an administrative task, then the policy process 240 skips to step 247 . However, if it is determined in step 245 that the task be performed is an administrative task, then the policy process 240 performs the admin process at the step 246 . The admin process is herein defined in further detail with regard to FIG. 12 . After performing the admin process, the policy process 240 skips to step 251 .
[0132] At step 247 , the policy process 240 performs the asset/claim process. The asset/claim process is herein defined in further detail with regard to FIG. 13 . After performing the asset/claim process, the policy process 240 skips to step 251 .
[0133] At step 251 , the policy process 240 determines if agent interaction is required. If it is determined that agent interaction is not required, then the policy process 240 skips to step 253 . However, if it is determined at step 251 that agent interaction is required, then the policy process 240 performs at the agent interaction process, at step 252 . The agent interaction process is herein defined in further detail with regard to FIG. 14 .
[0134] At step 253 , the policy process 240 then uses the new information (i.e. information from the quote process, admin process, or asset/claim process) to updates the database 12 and counting ballots is account at step 254 . At step 255 , the policy process 240 determines if there are more policies to be processed. If it is determined at step 255 that there are more policy to be processed, then the policy process 240 returns to repeat steps 242 - 255 . However, if it is determined that there are no more policies to be processed, then the policy process 240 exits at step 259 .
[0135] FIG. 10B is a flow chart illustrating an example of the operation of the policy app 700 for the remote device 15 of the present invention, as shown in FIG. 2B . The policy app 700 enables a user to acquire a quote for remote support, perform administration changes/modifications to the current policy or perform a claim process on an existing policy.
[0136] First at step 701 , the policy app 700 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the policy app 700 .
[0137] At step 702 , the policy app 700 for the remote device 15 waits to receive an action request. Next, a welcome screen explaining the services provided is displayed in the user is prompted to initiate an application from the icon displayed a welcome screen at step 703 . At step 704 , the user enters a valid key code when initiating the application from an icon. The policy app 700 accesses the policy server 11 to display a list of the policy providers, at step 705 .
[0138] At step 706 , the user is prompted to choose a whether the current action is with regard to a claim or quote. After the user selects the type of action with regard to a claim or quote, the policy app 700 connects to an agent to explain the claim or policy quote, at step 711 . Next, the user enters a private chat room with an agent at step 712 . In the private chat room, the agent assists with services that either the user or agent can control. The services that the user or agent can control include, but are not limited to, camera light, audio feed, video feed, text chat and the like. This is how the user and agent are able to disclose the actual state of apparatus/device needing a policy claim or policy quote.
[0139] Last, it is determined if there is more interaction with this user, at step 713 . If it is determined that there is more interaction with this user, then the policy app 700 returns to step 702 to wait for the user to initiate the action request. However, if there is no more interaction with the user, the policy app 700 then exits at step 239 .
[0140] FIG. 11 is a flow chart illustrating an example of the operation of the quote process 260 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 10 A. The quote process 260 enables a national call center to receive a contact from a user that wants to receive a new quote for a policy or complete a policy quote that was already initiated. Once the location of the user is determined, then the proper a regional office to handle the policy is determined.
[0141] First at step 261 , the quote process 260 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the quote process 260 .
[0142] At step 262 , the quote process 260 server 11 is initiated for sales. At step 263 , the zip code of the user is input. At step 264 , the ZIP code is used to determine which network region to route the potential sale.
[0143] At step 265 , it is determined if the user wishes to generate a new quote for a policy. If it is determined at step 265 that a new quote is to be generated, then the quote process 260 then skips to step 273 . However, if it is determined in step 265 that a new quote is not to be generated, then the quote process 260 requests the user to enter a key code to a quote that needs to be completed at step 271 . At step 272 , the information and the user are routed to a agent affiliated with the key code. The quote process 260 then skips to step 279 .
[0144] At step 273 , the quote process 260 determines a policy type that they user wishes to create. The policy types include, but are not limited to auto, home, business, life insurance services, and the like. Then, based upon the policy type selection, the information is routed to the agent supporting that policy type in the user's geographical region at step 274 .
[0145] The quote process 260 then exits at step 279 .
[0146] FIG. 12 is a flow chart illustrating an example of the operation of admin process 280 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 10 A. The admin process 280 enables a user to make a payment, and change address type information.
[0147] First at step 281 , the admin process 280 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the admin process 280 .
[0148] At step 282 , the admin process 280 determines if the user wishes to make a payment or a change address type information. If it is determined in step 282 that the user wants to change address type information, then the admin process 280 then skips to step 291 . However, is determined at step 282 that the user does not want to change address information, then it is determined that the user wants to make a payment. At step 283 , they user is instructed to take a picture of a check or credit card and upload that information to the admin process to me. At step 284 , the check or credit card is processed for payment.
[0149] Step 285 , the admin process 280 determines if the payment was processed successfully. If it is determined that the payment was unsuccessfully processed, then the admin process 280 skips to step 287 . However, if it is determined at step 285 . Payment was processed successfully, then the admin process 280 e-mails a confirmation of the successful payment processing to the user. This e-mail confirmation is a receipt as evidenced to the successful payment processing. The admin process 280 then skips to step 299 .
[0150] At step 287 , the admin process 280 generate a notice of denied payment that is e-mailed to the user. This e-mail is to put the user on notice that the payment was not successful and therefore at the policy may be canceled if payment is not received in a predetermined period of time. The admin process 280 then skips to step 299 .
[0151] At step 291 , then admin process 280 displays a change address prompt. This enables the user to update their address information. After entering the change of address information, the admin process 280 confirmed the address update at step 292 . At step 293 , the admin process 280 displays the ZIP code change prompt. This enables a user to update their ZIP code information. After entering the change of ZIP code information, that admin process 280 confirms the ZIP code update at step 294 .
[0152] The admin process 280 then exits at step 299 .
[0153] FIG. 13 is a flow chart illustrating an example of the operation of asset/claim process 300 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 10 A. The asset/claim process 300 enables a user to document all their current assets protected by a policy. These records of assets may be added to, modified and removed. In one embodiment, pictures of each asset are input into the asset/claim process 300 in order to verify the assets, their serial numbers and the like.
[0154] First at step 301 , the asset/claim process 300 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the asset/claim process 300 .
[0155] At step 302 , the asset/claim process 300 determines if the user wants to modify the current records of the user's assets. If it is determined in step 302 that the user does not want to modify the current records of the user's assets, then the asset/claim process 300 then skips to step 311 . However, is determined at step 302 that the user does want to modify the current records of the user's assets, then the asset/claim process 300 displays all of the current asset records for the user at step 303 . At step 304 , it is determined if the user wishes to add one or more asset records to the asset/claim process 300 . If it is decided that the user does not wish to add any asset records, then the asset/claim process 300 skips to step 306 . However, if it is determined that the user does wish to add at least one asset record to the asset/claim process 300 , then the user is encouraged input the new asset data at step 305 . The asset/claim process 300 then skips to step 307 .
[0156] At step 306 , the user is prompted to modify or remove old asset data records. These asset records are kept in order to have itemized list of those assets covered by a policy.
[0157] At step 307 , the asset/claim process 300 displays all of the asset data records for the user. At step 308 , the asset/claim process 300 determines if the user wishes to modify more records regarding the user's assets. If it is determined in step 302 that the user does want to modify the current records of the user's assets, then the asset/claim process 300 then returns to repeat steps 304 - 308 . However, is determined at step 308 that the user does not want to modify the more records of the user's assets, then the asset/claim process 300 skips to step 319 .
[0158] At step 311 , the asset/claim process 300 displays all the current assets for the user and any open claims. At step 312 , it is determined whether or not the user is contacting the remote servicing system 100 regarding a new claim. If it is determined at step 312 that the user is not contacting the remote servicing system 100 regarding a new claim, then the asset/claim process 300 skips to step 315 . However, if it is determined at step 312 that the user is contacting the remote servicing system 100 regarding a new claim, then the asset/claim process 300 gets the new claim number at step 313 . At step 314 , the user inputs the new claim data, and then the asset/claim process 300 skips to step 316 .
[0159] At step 315 , the user inputs new data for an old claim. This new data for an old claim to be any relevant information including but not limited to estimates for repair, estimates for replacing and the like.
[0160] At step 316 , the new data from the new policy or the old policy are sent to the claims department.
[0161] At step 316 , the asset/claim process 300 then exits.
[0162] FIG. 14 is a flow chart illustrating an example of the operation of agent interaction process 320 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 10 A. the agent interaction process 320 enables a user to connect to an agent to capture video, audio, text and the like information.
[0163] First at step 321 , the agent interaction process 320 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the agent interaction process 320 .
[0164] At step 322 , the agent interaction process 320 connects a user with a video agent with policy information gathered from a phone call, email or web query. The information collected and displayed is obtained from the database 12 at step 323 . Will be agent interaction process enables video asset analysis for VIN, assets, inventory of home for policy quote, ID registration and payment. It is understood that either the user or agent can control the video, camera or any other data capturing device.
[0165] At step 325 and electronic signature of documents and insurance cards for proof of insurance are provided. At step 326 , the proofs of insurance cards are saved to preferences of the application for off-line use. The off-line use, may be, but is not limited to access by law enforcement to determine whether or not there is a insurance policy on a vehicle to be in compliance with state law.
[0166] A. e-mail confirmation is generated and sent to the user as a receipt at step 327 . The agent interaction process 320 then exits at step 329 .
[0167] FIG. 15 is a flow chart illustrating an example of the operation of the intelligent routing process 340 that is utilized in the remote servicing system 100 of the present invention, as shown in FIGS. 2A , 3 A & 8 A. The intelligent routing process is one that determines if a user has contacted customer service agent previously for processing a claim, verifies that that agent is available and connect that agent to the customer if that customers desires.
[0168] First at step 341 , the intelligent routing process 340 is initialized. This initialization includes the startup routines and processes embedded in the BIOS of the server 11 . The initialization also includes the establishment of data values for particular data structures utilized in the intelligent routing process 340 .
[0169] At step 232 , the intelligent routing process 340 enables a user to contact customer service. At step 343 , the user enters the account information such as a phone number for tracking policies and claims. At step 344 , this server 11 references a valid account information utilizing the account info captured at step 343 . At step 345 , the intelligent routing process 340 checks the account information of the user against recent issues and agents handling those issues.
[0170] At step 351 , it is determined is the user has had recent issues. If it is determined at step 351 that the user has not had recent issues, then the intelligent routing process 340 then skip to step 355 . However, if it is determined at step 351 , that the user has had recent issues, then the intelligent routing process 340 determines if the agent who previously assisted the user is available at step 352 . If it is determined at step 352 that the agent who previously assisted the user is available, then the intelligent routing process 340 then skip to step 355 . However, if it is determined at step 352 that the agent who previously assisted the user is available, then the intelligent routing process 340 determines if the user wants to contact that agent to discuss the recent issue. If it is determined at step 353 that the user does not wish to contact the agent who previously assisted user, then the intelligent routing process 340 then skip to step 355 . However, if it is determined at step 353 that the user does wish to contact the agent who previously assisted user, then the call is routed to that agent at step 354 . The intelligent routing process 340 then skips to step 359 .
[0171] At step 355 , the call is routed to any other unavailable agent.
[0172] The intelligent routing process 340 then exits at step 359 .
[0173] Any process descriptions or blocks in flow charts should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.
[0174] It should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims. | An exemplary embodiment includes a system and method for delivering remote servicing on a computer system. The computer system includes a tangible storage medium readable by the instruction processing system and storing instructions for execution by the instruction processing system. The method comprises receiving a phone call from a customer and receiving a digital image of a device being serviced by a service representative. The method further includes displaying the digital image of the device being serviced on a monitor to the service representative, and determining if a service tech needs to make a service visit. | 7 |
RELATED APPLICATION
This application is a continuation in part of application Ser. No. 10/770,735 entitled “Apparatus and Method for the Repair and Stabilization of Underground Pipes” filed Feb. 3, 2004, now U.S. Pat. No. 7,135,087 and application Ser. No. 10/182,889 entitled “Apparatus, Methods, and Liners for Repairing Conduits” and filed Apr. 28, 2003 now U.S. Pat. No. 7,073,536.
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to an “insitu” method to repair underground pipes and conduits to reduce or eliminate ground water infiltration while stabilizing the proximate ground formation surrounding the pipes.
2. Background of the Invention
The Clean Water Act has mandated that ground water infiltration into our sewer systems be substantially reduced or eliminated. Many methods of repair have been devised over the last thirty years. Some of those repair methods include slip lining, pipe bursting, cured in place pipe lining (CIPP), fold and form thermoplastic lining, spot repairs, as well as the traditional dig and removal/replacement of pipelines.
It is a known fact that the federal interstate highway system has met and in certain cases exceeded its design life by controlling or reducing incidents of pavement collapse, settling and irregular surfaces. This has been achieved with the development of techniques for the injection of grouts or placement of epoxy patches. In addition, the concrete repair industry has developed and refined the utilization of expandable structural closed cell foams to raise, level and stabilize concrete slabs, foundations, pavements and buildings.
The “insitu lining” repair of pipes has been the most effective alternative to pipe “dig and replacement” for many year. Occasionally an existing annular space or void adjacent to the outside surface of the pipe or conduit has been injected with gelatinous grout materials to eliminate water infiltration into the pipe. This repair has been only temporary since the gelatinous material is not dimensionally stabile and often requires later replacement. The grout is not capable of stabilizing the ground around the pipe even if the entire annular space is filled with the gelatinous grout. The lack of stability and support can result in additional stress on the pipe structure, with eventual degradation of the pipe and resulting water infiltration.
Injection of expanding closed cell foams has seldom been used to repair pipes. Where the closed cell foams have been used to level or reinforce pipe sections, there has been migration of the foam into the pipe/conduit joint that, if left in place, can cause an occlusion or blockage. When this migration into the interior diameter of the pipe does occur, a cutting or grinding device must be inserted as a subsequent step to remove the excess foam.
Another issue is the typical foams being used today are polyurethane's which often contain isocyanate, a groundwater contaminant. Some research has been conducted to determine if the closed cell foam chemistry could be used with grout packers. The blowing agents in the foam, however, create a near immediate reaction that will not allow the annular space to be filled with the foam.
There are hybrid polyester/urethanes expandable closed cell foams that could be used and avoid isocyanate. However, these alternate foam formulations have not been well suited to curing in the ambient underground soil conditions.
Another method for repair of pipes has been to excavate a damaged pipe section and wrap the outer pipe wall with a high tensile strength material having an elasticity maintaining the band in contact with the pipe. See for example U.S. Pat. No. 4,700,752 of Norman C. Fawley. Another method has been to repair or reinforce a pipe section by wrapping the outer pipe wall with a composite material having a multiplicity of high tensile strength filaments encapsulated in a resin matrix. The wrapping material is manufactured in a coiled structure and installed by deflecting portions of the material into an uncoiled configuration and then wrapping those portions of the material around the pipe. The material may be applied with an adhesive coating on the pipe surface and between each coil layer. See for example Fawley, U.S. Pat. No. 5,683,529 and 5,677,046.
The measure of physical properties of materials relevant to the present invention include ASTM D1621 Compressive Strength, ASTM D790 Flexural Strength, ASTM D1622 Density, ASTM C 273 Shear Strength, ASTM D 2126 Dimensional Stability, ASTM D696 Coefficient of expansion, ASTM D 543 Chemical Resistance, and ASTM D 2842 Water Absorption.
SUMMARY OF INVENTION
Insitu pipe repair methods have been developed utilizing techniques for heat assisted cured in place pipe lining (“CIPP”) utilizing epoxy repair materials. This technology has allowed the use of styrene free thermosetting or thermoplastic resins in an impregnated (“prepreg”) composite repair material that is cured with an expandable and heatable bladder. Thermoset resins are curable resins that can be introduced or impregnated into a fibrous repair material. The curing of the resin results in a change of phase of the resin from a liquid to a solid. As a solid, the repair material continues to have the fiber structure. This technology has been adapted for use in the repair or sealing of pipes or conduits, including sewer mains and lateral lines, (“pipes”) and the junctions or interfaces of multiple pipelines.
This invention teaches the use of this technology in combination with the injection of chemical reactants creating expanding closed cell foam (“foaming liquids”) for stabilization of the surrounding ground proximate to the underground pipes. The heat assisted CIPP mechanisms and techniques for interior pipe repair thereby allow the use of more environmentally friendly foaming liquids than feasible in ambient conditions to stabilize the ground surrounding the pipe. The inflated bladder can provide a heat source for curing of the resin of the prepreg repair materials, closed cell foaming liquid resin and limiting resin redistribution, and a supporting mechanism for maintaining the pipe diameter and to prevent infiltration of the foam or foaming liquid into the pipe interior.
The invention also teaches use of the expandable bladder alone within the inside diameter of the pipe in combination with the injection of foaming liquids proximate to the exterior of the pipe surface. The invention also teaches use of an expandable and heatable bladder within the inside pipe diameter to assist in the cure of the injected foaming liquids.
The present invention provides for an improved method of stabilizing the adjacent underground soils or formation around the pipe, minimizing ground water infiltration into the pipe, while repairing the host pipe/conduit or connection. The invention also minimizes exfiltration of sewerage from the pipe. Such exfiltration is a problem particularly when the pipe system is fully charged during a rainfall event,
This invention also teaches the use of an elastically coilable and radially outward expandable material to support and repair pipes. The teaching of this invention includes use for the internal repair of the pipe wall. This may be used in conjunction with other embodiments of the invention such as soil compaction and stabilization using closed cell foam and resin cured pipe wall repair materials.
The invention also teaches use of a exterior tensioned support exerting a radially compressive force that may be used in conjunction with the interior support, an interior inflated bladder, or alone as a heat source combination with heat responsive repair materials.
Other benefits of the invention will also become apparent to those skilled in the art and such advantages and benefits are included within the scope of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention. These drawings, together with the general description of the invention given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1 illustrates a typical sewer pipe and lateral connection.
FIG. 2 illustrates typical defects necessitating repair of a sewer pipe and sewer pipe connection.
FIG. 2A represents a cross sectional view of a defective pipe.
FIG. 3A illustrates the prior art use of foaming liquids.
FIGS. 4A and 4B illustrate the use of the inflatable bladder in combination with injection of foaming liquid.
FIG. 5 illustrates the pipe repair equipment utilized with simultaneous repair of the pipe interior and ground stabilization.
FIGS. 5A through 5E further illustrate the pipe repair equipment.
FIG. 6 illustrates a detail of the woven repair material for a pipe interface repair.
FIG. 7 illustrates a woven repair material utilized in one embodiment of the invention.
FIGS. 8 and 8A are cross sectional views of a hybrid woven repair material.
FIGS. 9A and 9B are additional cross sectional views of other hybrid fiber woven repair material.
FIG. 10 is an illustration of the braided repair material.
FIG. 10A is an illustration of a rochelle knit.
FIG. 11 is an illustration of the helically wound repair material.
FIG. 12 is an illustration of multiply aligned pipe segments.
FIG. 12A is an illustration of misaligned pipe segments.
FIGS. 13 and 13A illustrate the realignment of pipe segments utilizing the invention.
FIGS. 14 and 14A further illustrate the realignment of pipe segments utilizing the invention.
FIGS. 15A through 15H provide a cross sectional view of the operation of one embodiment of the invention.
FIGS. 16A through 16C Illustrate cross sectional views of the tensioned support.
FIG. 16D illustrates a prior art method.
FIG. 17 illustrates the relationship of the pipe surface to the resin impregnated tensioned support with electrically conductive fibers for heating.
FIGS. 18A and 18B illustrate the combined application of internal and external tensioned supports.
DETAILED DESCRIPTION OF THE INVENTION
The above general description and the following detailed description are merely illustrative of the subject invention and additional modes, advantages and particulars of this invention will be readily suggested to those skilled in the art without departing from the spirit and scope of the invention. The teaching of this invention will be understood to be applicable for both the repair or support of sewer pipe connecting interface, as well as for linear and non linear pipelines.
FIG. 1 illustrates typical underground sewer pipe configuration that can be the object of repair by the method and apparatus of this invention. The pipes comprise a lateral line 500 typically emerging from a single building or home (not shown). The lateral line is installed for gravity drainage 640 into a collector sewer or sewer main pipe 200 through a connection or connecting interface 400 . Sewerage is gravity conveyed 650 through the diameter 300 of the sewer pipe 200 . The lateral pipe and the main sewer pipe each has a longitudinal axis 350 . However, over time, the orientation of the individual pipe segments may change from the original longitudinal axis, creating a “non linear” pipe. (Reference is made to FIGS. 14 and 14A .) Non linear pipe can also, of course, include curved pipe.
The lateral pipeline and the main sewer pipe are typically comprised of separate segments jointed by a male-female type connecting end flange. The female flange component 210 and corresponding male component 211 are illustrated in FIG. 2 . It will be appreciated that the sewer pipe system is buried within the ground 100 beneath the ground surface 105 . The system can be accessed through various ports such as manholes (not shown).
FIG. 2 is a cross sectional schematic of the sewer pipe 200 along the longitudinal axis 350 . The direction of the gravity flow of sewerage is shown by vector arrow 650 . The male 211 -female 210 coupling of the separate sewer pipe sections is also illustrated.
FIG. 2 illustrates a common problem experienced with sewer pipe systems. Due do a variety of causes, including the aging of the pipe material, ground shifts or settlement, etc., ground water 175 migrates into the sewer pipes 200 . This can cause the exfiltration of sewerage into the surrounding soil or ground water, particularly when the sewer lines are heavily charged, such as during a significant rain event. Alternatively, the infiltration of ground water can burden the sewerage treatment system thereby increasing treatment costs or causing inadequate treatment. (In addition to the obvious environmental is damages that may result from inadequate sewer treatment, the inadequate treatment may result in fines and other damages being imposed by regulatory agencies.)
The infiltration of ground water often carries particles of the adjacent soil 100 into the sewer system, which can over time result in voids 150 being created surrounding the pipe 200 . The creation of voids or increased interstitial spaces results in groundwater collecting proximate to the pipe. This groundwater can then pass, i.e., infiltrate, into the sewer pipe wall 250 through the cracks 240 or holes 255 . It can also pass through defects, such as gaps, in the junctions of each pipe segment 210 211 .
FIG. 2A is a schematic illustration across the longitudinal axis 350 of a section of the damaged sewer pipe 200 beneath the ground surface 105 and adjacent void 150 in surrounding soil 100 . Also illustrated are the pipe diameter 300 and cracks 240 and voids 255 through the thickness 251 of the pipe wall 250 . The several vector arrows 175 illustrate the flow of ground water from the soil 100 into the void 150 surrounding the pipe 200 and through the cracks 240 and holes 255 within the sewer pipe wall 250 . It will be appreciated that the voids intended to be remedied by the subject invention need not be of the large size depicted in these illustrations. Further, it will be appreciated that the subject invention is not limited to repair holes or cracks in pipes, but can be used to seal connections (or “couplings”) between pipe segments, or between pipe lines, e.g., a sewer collection pipe and one or more lateral pipes convey waste (“sewerage”) from individual residences, etc.
Use of close cell expandable foams have been used to fill subsurface voids in soils, including use to mechanically raise objects supported by the soil. This has been used in foundation leveling, etc., as taught by U.S. Pat. Nos. 4,567,708, 6,521,673 and 6,634,831. However, this technology has important limitations for use in filing voids surrounding sewer pipes or sealing/repairing pipe defects. One disadvantage is the infiltration of the closed cell foam into the interior pipe diameter (through which sewerage is intended to flow), thereby creating an occlusion that must be mechanically removed to prevent blockage of the sewage flow. In addition, the expansive pressure of the closed cell foam (useful in filling or compacting the soil particles or interstitial voids within the soil or between the underground soil and the structure, e.g., sewer pipe or lateral collector, to minimize water collection/infiltration), may also further damage the pipe wall.
FIG. 3A is a schematic illustration across the longitudinal axis 350 wherein closed cell foam 600 is injected from the ground surface 105 through the injection mechanism 650 into the void 150 within the ground 100 adjacent to damaged sewer pipe wall 250 . The foam equipment combines static head mixers 650 with a strong insertion device attached to pumps (not shown) located at the ground surface 105 . The cross section view illustrates the closed cell foam filling the void 150 and infiltrating into the diameter 300 of the sewer pipe 200 through the holes 255 and cracks 240 within the pipe wall 250 . The infiltrating foam is shown to create obstructions 337 338 339 within the pipe diameter 300 . It will be appreciated that the foam may not fill the entire void 150 , perhaps due to the presence of entrapped ground water (not shown), thereby allowing for the continued collection of ground water proximate to the repaired pipe. The
migration of foam into the pipe can ultimately block the pipe diameter 300 unless a cutter/grinder unit (not shown) is inserted into the pipe and the occlusion is removed. It will be appreciated that it is desirable to avoid this time consuming and expensive step.
One embodiment of the apparatus and methods taught in this specification is the advantageous use of techniques for installing a thermally responsive pipe repair material (thermoset or thermoplastic impregnated liner) within the interior diameter of a sewer pipe in combination with injection of expanding closed cell foam proximate to the outer diameter of the sewer pipe. The repair material for the interior pipe diameter may be of a variety of structures, including a structure being defined as an arrangement of fibers such that the repair material has similar dimensions as the pipe diameter or pipe interface to be repaired or sealed. The arrangement of fibers further allows the repair material to be flexible and seamless. FIG. 7 illustrates an example of a woven structure 410 having a longitudinal axis 350 . In the illustration, fibers 118 119 are intersecting at a variable angles 125 . It will be appreciated that the composition of fibers and fiber architecture can be varied, as shown in the cross sectional illustrations along the axis AA in FIGS. 8 , 8 A, 9 A and 9 B discussed later. In a preferred embodiment utilizing the repair material, the material includes a resin having a viscosity. An additive may be provided to alter the resin viscosity. It will be appreciated that it may be advantageous to increase resin viscosity to retard resin redistribution within the fiber repair material or fiber liner prior to and during the installation process.
A flexible and inflatable bladder is inserted within the pipe diameter. The bladder serves as a mold to press and hold the repair material to the interior surface of the pipe during the repair process. The inflated bladder, which, in an alternate embodiment of the invention, can be used without the resin impregnated repair material or liner, also minimize the migration of the chemical reactant or resulting foam injected into the underground soils proximate to the pipe. The migration of chemical reactants or foam can result in occlusion or obstruction of the pipe diameter. This would obviously hinder the flow of sewerage through the pipe.
The fibrous construction of the repair material, or the components of the inflatable bladder, can include conductive fibers, e.g., carbon fibers, that can be connected to an electrical power source. These conductive fibers, when powered with electric current, may provide electrically resistive or impedance heating (termed herein as “resistive heating”) directly through or immediately proximate to the thermosetting resin contained in the repair material. The combined and concurrent pressing of the resin impregnated fibers to the inner pipe wall surface with the heating of the thermosetting resin allows an improved repair and support. The addition of heat, in contrast to ambient conditions, allows more rapid curing. Further, this allows the bladder to remain in place as a mold pressing the repair material for a greater portion of the cure and minimizes the degradation of the repair by resin redistribution. It will be appreciated that the use of the expanding and heatable bladder also minimizes the formation of “annulae” between the interior pipe wall surface and the liner.
Further, heat from the bladder or repair material is also available to radiate through the thickness of the pipe wall to facilitate to the cure of the foaming liquid exterior to the pipe wall. Curing of the foam creates a phase change in the foam to a closed cell solid. The closed cell foamed solid can compact the underground proximate to the pipe, decrease voids or interstitial space containing infiltrating ground water, as well as support and seal the pipe and pipe junctions.
The availability of the proximate heat source also allows use of alternate foaming agents, particularly agents not containing isocyanates. It will be appreciated that isocyanates are considered to be a source of environmental contamination. These alternate reactants include hybrid polyurethane or polyester/polyurethane blend resin, and epoxy resins combined with diluents, catalysts, blowing agents and surfactants, an acrylimide, and cementitous slurry.
FIG. 4A is a schematic cross sectional illustration along the longitudinal axis 350 illustrating an embodiment of the method and apparatus of the invention by placing a flexible and inflatable heating bladder 450 inside the pipe diameter 300 . The bladder is placed in the area of the pipe having holes 255 or cracks 240 in the pipe wall 250 . In this manner, the inflated bladder can provide support to the damaged pipe and facilitate maintaining the pipe diameter 300 during the repair process. The bladder may have resistively heatable sub-components to facilitate the curing of the chemical reactant injected proximate to the exterior pipe wall surface 254 .
FIG. 4B is a schematic illustration across the longitudinal axis 350 of the pipe after inflation of the bladder 450 . The bladder, if used as a heat source, may assist in the curing of the closed cell foam. It will restrain the injectable chemical reactant and resulting foam 600 from permeating the pipe through coupling connectors ( 211 210 of FIG. 2 ) or cracks 240 or holes 255 in the pipe wail 250 . The migration of foam is illustrated in FIG. 3A by the multiple vector arrows. The liner 410 (not shown) may be placed over the bladder for reinforcement or to minimize binding of the bladder to the cured foam.
An embodiment of the invention includes the use of resistive energy as a source of heat for curing the injected chemical reactant, as well as to block the migration into the pipe diameter. This heat curing can be accomplished in combination with the placement of a resin impregnated (“prepreg”) repair material within the pipe diameter. As mentioned above, the repair material or the flexible bladder may contain electrically conductive fibers. Alternatively, the fiber can be a combination of electrically conductive fibers and non-conductive fibers, which include polyester, glass, aramid, and quartz fibers, and thermoplastic fibers such as, but not limited to polypropylene, nylon and polyethylene.
The repair process is illustrated in FIGS. 4A , 4 B and FIGS. 15A-H where one skilled in the respective arts observes that there are similarities in both systems, which require 50 K.W. generators and 150 CFM compressors and various cables and hoses. The present invention demonstrates the synergies between the two systems, which eliminates boiler trucks, and on site mixing and impregnation of repair material.
An alternative embodiment that can be used alone or in conjunction with the bladder is inserting an elastically coilable and radially expandable material. This can be of differing materials, including metal. Important features will be the elasticity, high strength and shape memory, thereby allowing the material to be wound into a tighter coil with a more compact diameter or shorter radius and expansively returning to its original shape. Upon release of the winding energy, the material relaxes and returns to its original coil diameter. This relaxed diameter will be greater than the internal pipe diameter, thereby causing a relative uniform radial outward pressure force.
It will be appreciated that the mechanism will maintain an open annulus within the pipe thereby allowing the continued passage of fluids through the pipe. Of course this can permit the relaxed coil to remain in place during the curing process, and thereafter without interruption of service.
This invention addresses the cause and repair of connection offsets or misalignment of pipes and conduits. The misalignment of an originally installed linear pipe may result from faulty bedding surrounding the pipe, which is not tested as it is in pressure pipe/conduit situations, and ultimately can crack or offset the joints after the pipeline is back-filled. Another cause of misalignment is the result of the movement of ground water as already discussed. While some may contend this method is redundant and more costly, one skilled in the art will easily recognize the efficiencies and safety elements of the present invention.
This embodiment of the invention provides methods of repairing the misalignment of pipe sections 250 A such as that shown in FIG. 12A . In this case, the non-linear conduit is buried below the ground surface 105 predominantly in a horizontal orientation as part of a pipe network, e.g., sewer system. The non-linear pipe consists of separate pipe or conduit segments 25 A, 25 B, 25 C, 25 D, 25 E, 25 F, 25 G that have moved from the original longitudinal axis 350 illustrated in FIG. 12 to a non congruous longitudinal orientation 351 and thus does not follow a strictly linear path.
The embodiment of the method taught by this invention comprises providing the inflatable bladder dimensioned to fit within the interior diameter 300 of the pipe 250 A, and particularly each non-congruous pipe segment 25 A, 25 B, 25 C, 25 D, 25 E, 25 F, 25 G. The bladder is dimensioned so as, when inflated, presses against the interior surface of each damaged, e.g. mis-aligned, cracked or broken, section of conduit. The bladder can be made of any strong flexible material. It will be appreciated that it may be advantageous to fit the bladder with one or more layers of protective outer sleeves or liners (“liners”). The liners can provide a repair material (sometime referred to as “material structure”) as discussed elsewhere herein, but may also provide protection to the bladder from sharp or jagged surfaces within the conduit sections. The bladder may be filled/inflated with fluid, such as water or air, and the effectiveness of the bladder would be compromised if the bladder was punctured.
FIGS. 13 and 13A illustrate an embodiment of the invention wherein the bladder 450 is placed within the diameter 300 of several mis-aligned pipe segments 25 A, 258 , 25 C, 25 D, 25 E, 25 F, 25 G beneath the ground surface 105 . FIG. 13 illustrates the bladder with several pipe segments 25 B 25 E removed for clarity of illustration. The original or intended longitudinal axis of orientation 350 is also shown. It will be appreciated that the mis-alignment may be in any of the three axes of orientation (X, Y, Z),
FIG. 14 illustrates the next step of the repair method. Multiple chemical reactant insertion ports 650 are installed from the ground surface 105 to a desired location proximate to the pipe. In the illustrated situation, the ports are installed to be beneath the mis-aligned pipe segments 25 B, 25 C, 25 D, 25 E, 25 F. The goal of the repair is to push the pipe segments into closer alignment with the longitudinal axis 350 . A chemical reactant is injected through the ports into the ground 100 creating the expanding foam 600 . FIG. 14A illustrates the result of the injection of expanding thermosetting foam 600 , causing pipe segments 25 B, 25 C, 25 D, 25 E, 25 F to be pushed upward as shown by vector arrow 675 . The inflatable bladder 450 acts as a flexible mold having a control or guiding function in the realignment of the pipe sections, particularly with regard to the continuity of the pipe diameter 300 and common longitudinal axis of orientation 350 .
As suggested by the FIGS. 12 through 14A , substantial length of pipe can be simultaneously repaired by the invention. The length of inflatable and heatable bladder is not limited. Lengths of pipe extending from one access manhole to a second manhole may easily be simultaneously repaired by a single use of the method and apparatus of the invention.
Based upon the foregoing disclosure, it will be readily appreciated that the above method can be combined with the embodiment utilizing a repair material liner impregnated or containing a curing thermosetting or thermoplastic material to seal the pipe from the interior diameter. The repair material structure may be defined by a plurality of fibers such that the repair material is flexible and seamless. This structure is sometimes referred to as a woven “preform”.
The resin may be in the form of prepreg fibers or as a resin matrix surrounding the woven structure. The resin can be a polyester resin, a vinylester resin, a urethane polyester resin, a urethane-vinylester resin, an epoxy resin of a polyurethane resin. The resin is introduced into the repair material by either injection of infusion depending on the type of resin utilized.
A flexible and seamless repair material is able to adapt and conform to of the interior repair material will neither bind nor wrinkle to cause obstructions to material flow in the conduit. The construction and selection of the repair material also allows it to be used in conjunction with the inflatable bladder. The repair material may be placed as an outer liner on the deflated bladder.
Next, the repair material and bladder is placed in the conduit in close proximity to a damaged portion of the conduit. As the bladder is inflated, the repair material is pressed against the inner surface of the conduit wall. Finally, the resin is cured. Curing can be achieved in a number of ways, including but not limited in using hot water, steam, resistive heating, or infrared and ultraviolet radiation.
Preferably the material structure 410 is substantially cylindrical (as shown in FIGS. 7 and 11 ) to facilitate conformity with the non-linear conduit. The cylindrical structure has an interior diameter 301 oriented about a longitudinal axis 350 . However, the material structure is flexible and can be formed by braiding the fibers. A repair material 410 having a braided configuration of fibers 411 is shown in FIG. 10 . In braiding most, if not all, of the fibers 118 119 are arranged in a helical pattern (as shown in FIG. 11 ). However, triaxial braiding can be used to combine fibers at two different axial or helical angles with a non-helical, longitudinal fiber. Repair materials fabricated by braiding processes offer exceptional ability to conform to irregular conduit geometries. Because a braided repair material is formed with its reinforcing fibers positioned helically rather than perpendicularly to the longitudinal axis of the material structure, these fibers have the ability to change their braid angle 125 , and conform simultaneously in both the inside radius and outside radius of a section of a non-linear conduit.
Depending on the desired mechanical properties the density of the fiber braid can be varied to pack more fibers into the tubular arrangement to provide an increase in strength. Conversely, if the structural requirements are minimal, the braid density can be adjusted to where the material present in a volumetric area can be reduced. The angle 125 at which the fibers intersect each other, otherwise known as the braid angle, can also be varied. When the braid angle is increased, the fibers are positioned closer to perpendicular or vertical and the hoop strength of the finished repair material increases. This is desirable for conduits that are required to support a great amount of weight or withstand high Internal pressures. The varying mechanical fiber compaction can be used, e.g., knitting, weaving and braiding,
Use of braid or similar types of mechanical fiber compaction construction also will facilitate the unlimited lengths of pipe that may be simultaneously repaired.
FIGS. 8 , 8 A 9 A and 9 B are cross sectional representations of the fiber layers of a repair material Illustrated in FIGS. 7 and 11 . Various reinforcing materials can be included in the braided construction to accommodate both performance and cost issues. FIG. 8 illustrates a combined placement of reinforcing fibers 122 , e.g. glass or nylon, with fibers 124 constructed of thermoplastic material. These fibers can be one of a combination of various engineered thermoplastics. In addition, thermoplastic films 130 may be used. These fibers, films and reinforcing fibers can be consolidated using any of the aforementioned methods. FIG. 8A illustrates repair material 410 comprised of a combination of reinforcing fibers 122 impregnated within a matrix of resin 131 . Various nonelectrically fibers can be employed as reinforcement. The fiber construction can be varied as shown in FIG. 9A . The combination of fibers forms the material structure 410 . Additionally FIG. 9A also shows a film 130 of thermoplastic material that forms part of the material structure 410 .
Additionally, FIG. 9B illustrates that the material can include electrically conductive fibers 120 , for example carbon fibers, in order to cure the resin and electric current can be caused to flow through the conductive fibers to resistively heat the repair material. The fibers can be a combination of electrically conductive fibers 120 , thermoplastic fibers 124 and non-conductive fibers 122 e.g., polyester, glass, aramid, and quartz fibers. Other combinations and architectures will be apparent to persons skilled in the art.
When electrically conductive fibers are used in conjunction with the thermoplastic fibers and films, as illustrated in FIG. 9B , resistive heating can be generated. The heat causes the thermoplastic materials to melt and flow, permeating the electrically conductive fibers and other non-electrically conductive fibers. A reinforced thermoplastic composite results when the materials cool and harden. In this embodiment, the need for liquid thermosetting resin (which phase change solidification may be enhanced by the addition of heat) is eliminated offering unlimited shelf life and case of handling. Finished composite properties can be customized with the selection of an appropriate thermoplastic matrix and reinforcing fibers.
As shown in cross section in FIGS. 8 and 9A the repair material can contain fibers having both structural properties 122 and thermoplastic fibers 124 . Alternatively separate bundles of electrically conductive fibers 120 can be co-mingled with bundles of thermoplastic fibers 124 and structural or reinforcing fibers 120 as shown in FIG. 9B . In both cases, the bundles may be braided together to form the repair material.
In another preferred embodiment, the electrically conductive fibers have an exterior layer or coating of electrically conductive fibers than are then braided. In another preferred embodiment, the seamless material structure is formed by knitting the fibers. In knitting, the repair material is produced by inter looping continuous chains of fibers in a circular fashion. An enlarged view of knitted fibers 118 119 120 is shown In FIG. 10A . In a rochelle knit, it is possible to introduce the fibers in a basically longitudinal direction. Because the fibers 118 119 are looped in a circular fashion at every stitch, the finished tubular structure is inherently flexible. For example, in one linear inch of fiber stitch, the actual fiber length may be as long as two inches. This allows continuity in the fibers throughout the length as well as allowing the fiber loops to stretch or open up to variances in the conduit geometry. Various reinforcing materials can also be included in the knit construction to accommodate both performance and cost issues. In addition, electrically conductive fibers 120 can be used such that resistive heating is feasible to cure the resin.
In another preferred embodiment, the seamless material structure is formed from a combination of two or more material layers. A first material layer is a seamless, cylindrical tube configured to fit within a second material layer that has a seamless, cylindrical tube configuration. The material layers are formed from an arrangement of fibers, preferably either braided or knitted fibers. The first material layer is nested within the second material layer and then stitch-bonded together with a stitching thread to form the materials structure. Preferably, the stitch-in thread is elastic to further ensure flexibility of the repair material. In addition, electrically conductive fibers can be used such that resistive heating is feasible to cure the resin.
Stitch bonding is a method by which different materials can be consolidated into various forms including seamless, tubular products. The consolidating results from either continuous or intermittent stitching or sewing through the various layers materials. Reinforcing fibers can be used and aligned in a helical arrangement to a accommodate geometry changes much like a braided composite. Stitch bonding also allows the use of a wider variety of electrically conductive material formats such as non-woven graphite formed into tapes. These tapes would be introduced into the composite at a helical angle.
In another preferred embodiment, the seamless material structure is formed from a combination of two ore more material layers. A first material layer is a seamless, cylindrical tube configured to fit within a second material layer that also has a seamless, cylindrical tube configuration. The material layers are formed from an arrangement of fibers, preferably either braided or knitted fibers. The first material layer is nested within the second material layer and then needle punched with a needle board to form the material structure. The needle board has a plurality of needles such that the needles penetrate the first material layer. When needles are driven through the first material layer, varying amounts of fibers from the first material layer are pulled through the cross section of the adjacent second material layer. These fibers effectively bind the material layers together. In addition to consolidation, the fibers also provide reinforcement in the Z axis, defined as the axis corresponding to the material layer thickness. The characteristics of the repair material, including flexibility, can be altered by varying the force applied to the needle board, the type and number of needles used, and the number of needle penetrations per square inch. In addition is electrically conductive fibers can be used such that resistive heating is feasible to cure the resin.
In another preferred embodiment, an additive adapted to increase the resin viscosity is provided. The additive is mixed with the resin to form a resin-additive mixture whereby the resin viscosity is increased after a period of time has elapsed. The additive should be formulated such that the resin viscosity does not immediately increase because this could preclude either resin introduction or resin permeation of the repair material. The resin additive adheres to the fibers in the first and second material layers. As a result, the resin additive mixture stabilizes the fibers and the material layers. In addition electrically conductive fibers can be used such that resistive heating is feasible to cure the resin.
FIGS. 15A through 15H illustrate the sequential steps of the combined application of curing a foaming chemical reactant proximate to the exterior of underground 100 pipes, with placement of a curable liner on the interior pipe surface. FIG. 15A is a cross sectional view of a pipe 250 beneath the ground surface 105 and having an interior diameter 300 . The pipe has a longitudinal
axis of orientation 350 . The pipe has an inner wall surface 256 , an exterior wall surface 254 and a wall thickness 251 . Also illustrated is an insertion port 650 for injecting expanding foam reactant at a selected location in relation to the buried pipe. Also shown is the deflated bladder 450 and separate material structure 410 positioned as an outer liner to the bladder.
FIG. 15B illustrates the same components within the ground 100 , but with the bladder 450 now inflated and placing the material structure/repair material 410 into near contact with the inner pipe surface 256 . The diameter 301 of the material structure is shown. In this cross sectional view, only a small to portion of the original pipe diameter 300 is not occupied by the inflated bladder and material structure.
It will be appreciated that the bladder 450 is to be inflated to press the structural material 410 into contact with the inner pipe wall 254 and the space shown in the following Figures is for clarity of illustration only.
FIG. 15C illustrates the foaming chemical reactant 600 being injected into the ground 100 . The foam variously expands in all directions, as illustrated by the several vector arrows, creating a force compacting the underground soil, driving away interstitial groundwater and pressing against the outer pipe wall 254 now reinforced by the inflated bladder 450 . FIG. 15D illustrates this process with multiple injecting foams, causing the pipe to be substantially encased in the expanding foam 600 , thereby compacting the ground, driving interstitial groundwater, minimizing or filling voids adjacent to the pipe and thereby stabilizing the pipe.
FIG. 15E illustrates the curing of the foam assisted by electrically resistive heat created from current within the electrically conductive fibers within the repair material 410 . A portion of the radiating heat travels outward into the thickness of the pipe wall 251 and into the surrounding ground or foam. The distance or range of significant heat transfer 005 may be less than the area occupied by the foam 600 . However, within this area 605 , effective curing of the foam can be achieved, thereby effectively encapsulating the pipe wall, while simultaneously installing an interior reinforcing material. (In another embodiment discussed previously herein, the conductive fibers can be contained within the bladder or a protective liner of the bladder separate from any repair material.)
FIGS. 15F and 15G illustrate a cross sectional area of the invention, illustrating the interior diameter 301 of the repair material 410 containing the inflated bladder 450 , the pipe thickness 251 , the area 605 of foam cured by the radiant heat, the outer area of foam 600 and the surrounding ground 100 .
The present invention also provides methods and apparatus for repairing a section of non-linear pipe such as the junction or interface 400 between two pipes 200 500 as illustrated in FIG. 1 . A preferred embodiment of the apparatus of the present invention is depicted in FIG. 5 . In accordance with the invention, the apparatus includes a main body 460 that is positioned in a first conduit 200 . The first conduit 200 may be pipe forming a main line of a sewer system. The main line 200 intersects a second conduit or lateral line 500 . Lateral line 500 is shown here in a perpendicular position essentially at a 90 angle to the main line pipe and intersects the main line pipe at the top portion. This condition is typical but may also be arranged in other configurations. For example, the lateral pipe may intersect the main line pipe at ±45 and can be located radially anywhere from the nine o'clock position to the 3 o'clock position.
Radial and vertical positioning of the apparatus is achieved remotely using appropriate controls, and communicated to the apparatus through an umbilical 350 . The entire assembly 460 is delivered to the point of repair using a winch or similar device (not shown) attached to the unit via cable assemblies 345 . Also illustrated are the heatable caul plates 465 and the flange portion of the repair material 411 . (It will be appreciated after reading the following paragraphs that FIG. 5 illustrates the repair material in a loaded position within the main body 460 of the apparatus.
FIG. 5A provides a cross sectional view of the apparatus depicted in FIG. 5 , showing the heatable caul plates 465 in a retracted position on an upper portion of the body 460 of the apparatus, thereby affording a minimal cross section and allowing passage into a main line that may contain offsets, protrusions, etc. The caul plates 465 (hereinafter referred to as “wings”) are articulated to allow this reduced cross section by the use of hinges 466 .
FIG. 5A illustrates the loading of the repair material 410 into the apparatus 460 in preparation for insertion at the intersection of the main line and lateral line. Repair material 410 is preferably constructed of a fibrous woven material capable of holding a heat hardenable or formable resin matrix. Material 410 is also constructed of a material that would be expected to include a portion 412 that conforms to the interior geometry of the lateral pipe wall, and be flexible enough to provide a flange face 411 in the main line pipe. (Reference is also made to FIG. 6C .) It is shown that the repair material is wrapped around the retractable/inflatable bladder segment 440 . In 5 C, the method for loading the repair material 410 is also illustrated. Applying a fluid pressure to the body 460 through umbilical 350 pressurizes an inflation device in the form of a bladder 440 . This fluid pressure is regulated through the use of electro-pneumatic regulators located in rear housing 461 in the body 460 , and controlled remotely through signal wires in umbilical 350 . Pressure sensing is accomplished by sending units located within main body and transmitted through umbilical. All of the signal wires in the umbilical terminate at an operator interface control station (not shown). The force required during this step in minimal and sufficient to cause the bladder 440 to rigidize.
The repair material is constructed in such a fashion as to incorporate both the tubular lateral lining portion 412 as well as the flanged area 411 without the undesirable effect of a potentially weak seam at the transition from tubular to planar. With the bladder 440 pressurized, the material 410 , which may be pre-impregnated with a resin as described elsewhere in this specification, is wrapped 412 around the extended bladder 440 as shown by the vector arrow 676 and caused to lay flat 411 on the surface of the wings 465 . Depending on the structural requirements, layers of material can continue to be plied to achieve the desired strengths. With the lay-up complete, the pressure of the bladder 440 is lowered the material 410 can be inverted into the main body of the apparatus as shown in FIG. 5C . The main body contains a spindle 453 capable of rotation that is fixably attached within the body 460 at a posterior location. The spindle is sealed from the atmosphere to the use of o-rings and protrudes slightly from the body to allow attachment of a tool to cause rotation.
As shown in FIG. 5D , the bladder construction contains an internal tether 451 that is permanently attached to the interior of the bladder at fitting and removably attached to spindle 453 within the main body 460 . To invert the bladder 440 and repair material 410 into the main body for safe transport to the repair location, the tether is wound about the spindle causing the bladder to retract. With the repair material loaded into the device, a winch, or similar device is employed to pull the apparatus to the desired location within the pipeline. A closed circuit television camera (not shown) can be used to assist in determining the correct location and positioning. Once the entire assembly has been satisfactorily located in proximity to the repair area, final positioning commences vial remote control.
FIG. 5D shows the internal working of the apparatus. In order to facilitate rotary position, the apparatus contains a powered rotation mechanism located in the rear housing 461 . The rotational mechanism is attached to the main body by use of a coupling. The front section 462 of the body 460 contains a rotary bearing to compliment this action. Skids 472 are attached to both the front 462 and rear 461 sections to afford minimal surface contact with the main line pipe and ease pulling forces required.
FIG. 5D illustrates the apparatus used for placement of the flexible bladder 440 at the pipe interface section 400 . The apparatus is positioned in radially and longitudinally within one pipe 200 . The lift cylinders can be elevated by hydraulics or compressed air using a suitable medium. The lift cylinders are firmly attached to the front section 462 and rear section 461 with cylinder rams attached to the main body. When activated, cylinders 473 effectively lift the main body to force the top portion of the caul plate 465 to be in contact with the interior wall of the main line pipe at the area surrounding the lateral pipe opening. As the main body lifts, actuator arms 474 encounter the main line pipe wall, as depicted in FIGS. 5D and 5E . In FIG. 5E , the actuator arm bearings 474 convert the vertical motion to a lifting motion through a fulcrum attached to the main body. The opposite ends of the actuator arms are position under the wings 465 and cause the wings to unfold and compress the flanged area 411 of the repair material firmly against the main line pipe walls.
By introducing pressure to the interior of the main body through umbilical, the bladder and repair material is caused to invert into the lateral pipe. Increasing the pressure inside the bladder causes the tubular section of the repair material to conform to the inside geometry of the lateral pipe section.
The bladder and the caul plates may be constructed of a temperature resistant material and contain within the outer skin surface, electrically conductive fibers that are employed to produce heat when an electrical current passes through the fibers. The material surrounding the conductive fibers is a flexible, resilient substance such as silicone, fluorosilicone or fluoropolymer. Electrical wires conduct the electrical energy from remotely stationed, controllable power supplies to the electrically conductive fibers. Heating temperatures may be produced range between 200° F. to 400° F. depending on the cure requirements of the resin matrix selected for use in the repair material. These temperatures can be achieved in as little as 10 minutes enabling an extremely fast cure cycle.
In conjunction with the inflation of the bladder into the interior diameter of the pipe interface and the heating of the bladder and caul plate, reactants can be injected into the ground proximate to the interface to compact the soil and stabilize the soils adjacent to the pipe similar to the manner discussed earlier in regard to FIGS. 2 through 4B above. The inverted bladder thereby also serves to minimize the infiltration of injected reactant or reaction product into the interior diameter. Further, it will be readily appreciated that the heat of the bladder, caul plates or liner may be available to radiate through the thickness of the pipe wall to facilitate the cure of the injected reactant. Again, this heat source may also allow the use of reactants that are not effective in the ambient subsurface environment.
An alternate method and apparatus to the inflatable bladder is the utilization of a radially expanding interior support. The support taught by this specification utilizes a tensionable and compressible coil. The coil possesses a memory of its original coil radius. After the compressive means are removed, the coil returns (“relaxes”) to its original radius. This characteristic is a property of material elasticity. When subjected to a stress, e.g. tensile or compressive, the dimensions of the material change, i.e., strain. For an elastic material, the strain is recovered when the stress is removed. When properly dimensioned, as taught herein, the interior pipe wall surface retains the coil in a partially tensioned stated, with a residual outer pressing force. This force, like the outward pressure of the inflated bladder, can be used to form a repair liner or surface patch within the pipe. Unlike the bladder, the coil does not impede the flow of liquid through the pipe and can remain in the pipe as a structural support element, as well as a mechanical means to press and cure repair materials such thermosetting or thermoplastic materials. It can also block the infiltration of injected reactant, or the resulting cured closed cell foams that are also taught by the invention.
The coil apparatus can be constructed in various forms. One embodiment may utilize a resinous plastic material having sufficient elasticity to allow compression without permanent deformation of shape. The material may be constructed to also include electrically conductive fibers or wire that can be connected to either a dc or ac power source to provide resistive or impedance heating (generally termed resistive heating herein). As already discussed herein, the heat may be utilized in curing or shaping thermally responsive materials that may be used in conjunction with this invention.
The coil support structure may also have a fibrous structure that may be impregnated with resinous thermal responsive materials. These materials may be thermal plastic or thermal setting resins. In the case of thermal setting materials, the ability to provide heat while in a pressed state to the interior pipe wall may shorten the repair cycle. It may also provide for improved repair by minimizing voids between the pipe wall and the material caused by shrinkage during the material cure or setting.
The material may utilize ester or epoxy resin systems that are allowed to partially cure, preferably to a B stage, without significant cross-linking, prior to release of the tension coil energy. At this partially cured stage, the impregnating resin remains malleable to conform to the vagaries of the interior surface of the pipe wall. This will minimize voids or undesired annular spacing remaining between the relaxed support surface and the interior pipe wall. It will be appreciated by persons skilled in the art that a B stage cured resin is at a highly viscous state, substantially able to retain a shape, but sufficiently plastic to be malleable to the irregularities of a contacting surface. As curing progresses to a C stage and to final cure, cross linking of the polymer molecules increases and thereby creating increasing rigidity of the material, resulting in a solid material at completion.
The support structure may also incorporate multiple layers of reinforcement material combined together as a single layer coiled within the interior with minimal overlap (as illustrated in FIG. 16B ). The multiple layers may be attached by needle punching or mechanical means. Lateral movement of the layers as a result of the coiling process may be contained by the mechanical intra-laminar attachments, thereby enhancing the shape memory, i.e., the recovery of the shape after removal of the stress or tension force. The support structure may also utilize adhesive properties or materials to bind to the pipe wall.
FIG. 16A illustrates a cross section of a pipe 250 having an interior diameter of D 2 . FIG. 16B Illustrates a flexible coil 480 having an outer diameter of D 1 that is larger than the interior diameter of the pipe. FIG. 16C illustrates the flexible coil wound into a tighter coil with a new diameter D 3 . This second diameter, achieved by the tighter winding of the coil, is smaller than the first diameter and the interior diameter of the pipe. This relationship can be expressed as D 1 >D 2 >D 3 .
FIG. 16D illustrates a prior art method of pipe 250 repair utilizing a tensioned coil 499 that is wrapped around the exterior of the pipe. The method utilizes wrapping a multi-layered coil having a radius smaller than the exterior diameter of the pipe. The coil material possesses memory of its first coil radius. It there for tends to adhere closely to the outer surface of the pipe (the circumference of the pipe having a larger radius than the first radius of the coil). Of course, the coil can only be wrapped around a pipe having a 360′ exposed surface. This would require a buried pipe to be excavated for application of such a coil wrapping.
FIG. 17 illustrates a cross section view of a coil 480 in relation to the interior surface 256 of the pipe. Also illustrated are electrically conductive wires or fibers 122 that are surrounded by a B stage ester or epoxy resin matrix 130 . The shape memory properties of the coil material matrix cause the outer coil surface 481 to press the resin matrix to the inner pipe surface as shown by vector arrow 640 . Also illustrated is a tension support substrate 132 that may comprise a resinous plastic material or a metal or combination of both.
Another embodiment of the invention subject of this specification teaches utilization of internal support with the exterior wrapped tension coil support to create an interior and exterior walled mold. A defect cavity enclosed within the walled mold or “form” can be then injected with repair material. In one embodiment, the repair material can be injected closed cell foam creating chemical reactants. The reactants will be maintained under pressure within the form, thereby creating enhanced density of the foaming reaction products. The pressure or material strength of the repair mold is attributed to the combination of material strength and the tensioned architecture.
FIG. 18A illustrates a cross sectional view of across the longitudinal pipe axis 350 . FIG. 18B illustrates a cross sectional view of one section of pipe wall along the longitudinal axis 350 .
FIG. 18A shows the pipe wall 250 having a inner surface wall 256 and an outer surface 254 . Within the pipe annulus 301 , the tensioned coil 480 support is released and allowed to unwind, resulting in the outer surface of the support pressing radially outward in the direction of the vector arrows 640 . It will be appreciated that the radially directed force applied to the inner pipe surface 256 will be substantially uniform around the circumference of the pipe.
The outer surface of the tension support may be coated (not shown) with an adhesive or thermal responsive material, e.g., thermal setting, thermal plastic or a resin chemical reactant. Alternatively, the support material may impregnated with such components. As described elsewhere herein, the tensioned support may also incorporate electrically conductive materials for heating. The outer pipe wall surface 254 is tensioned wrapped with a material 299 similar to the internal tensioned support, i.e., an elastic material with a matrix memory resulting in it contracting to its relaxed radius (being smaller than the radius of the outer pipe wall). The inner surface of the outer wrap, placed in contact with the outer pipe wall, may also have an adhesive coating or coating of a thermal responsive material. The outer wrap also will have a radially inward compressive force illustrated by the vector arrows 641 . This compressive force will also be substantially uniform around the circumference of the pipe 250 . The outer wrap may also contain electrically conductive materials for heating. The pipe wrapping action is indicated by vector arrow 643 . The outer wrap may also have one or more inlets 498 through which expansive foaming chemical reactants may be injected. It will be appreciated that the gap or space shown in FIG. 18A between the pipe and each tensioned support is for clarity of illustration only and that the surfaces will be in close contact.
FIG. 18B illustrates a cross sectional view of the pipe 250 along the longitudinal axis 350 . The inner tensioned support 480 is shown in contact with the inner pipe wall 256 . The surface interface 484 may contain a coating or thermal responsive material. The outer wrapped tension support 499 has a similar interface 497 with the outer surface 254 of the pipe wall 250 . FIG. 18B also illustrates a hole or defect 255 in the pipe wall that is contained with the tension inner and outer supports. This void or “repair cavity” 255 may be filled by material injected through the injection port 498 via a pipe or hose 605 . The inner and outer tensioned support will have sufficient strength to contain the foam reactant. Due to the confined fixed volume of this repair cavity, the injected reactant (not shown) may achieve increased density that if permitted unrestricted expansion.
While specific embodiments have been illustrated and described, numerous modification are possible without departing from the spirit of the invention, as the scope of protection is only limited by the scope of the accompany claims,
This specification is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and describe are to be taken as the presently preferred embodiments. As already stated, various changes may be made in the shape, size and arrangement of components or adjustments made in the steps of the method without departing from the scope of this invention. For example, equivalent elements may be substituted for those illustrated and described herein and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of is the invention.
Further modifications and alternative embodiments of this invention will be apparent to those skilled in the art in view of this specification. | The apparatus and method for eliminating ground water infiltration while stabilizing the ground and repairing underground pipe/conduit and connections is taught in this art. The steps are to first inject, under pressure, expandable structural foam in the space adjacent and outside the pipe while blocking any infiltration of the foam into the interior of the pipe, conduit or connection. Concurrently or separately the inside diameter of the pipe is receiving a structural repair. The result is stabilized ground, elimination of ground water infiltration and repair of the host pipe conduit or connection. The invention also teaches a novel method of utilizing a tensioned and compressive support on the outer pipe surface. | 4 |
BACKGROUND
Microencapsulation of cells and/or cell aggregates for implantation in an animal is an area or research currently attracting much interest. The use of microcapsules provides the potential for such medically important procedures as treatment of insulin-dependent diabetes mellitus (IDDM) in humans through transplantation of insulin-producing cells or cell aggregates, and timed release or long term delivery of drugs to an animal.
A variety of procedures for encapsulating useful cells have previously been tried. These procedures include coating cells with both polyanionic and polycationic layers to create a membrane around the cells which is impermeable to antibodies and other elements of the immune response. See for example Lim U.S. Pat. No. 4,352,883, Lim U.S. Pat. No. 4,391,909, Lim U.S. Pat. No. 4,409,331, Tsang et al. U.S. Pat. No. 4,663,286, Goosen et al. U.S. Pat. No. 4,673,566, Goosen et al. U.S. Pat. No. 4,689,293, Rha et al. U.S. Pat. No. 4,744,933, Rha et al. U.S. Pat. No. 4,749,620, and Goosen et al. U.S. Pat. No. 4,806,355.
Biocompatibility problems have arisen with a number of these prior art methods. The body soon rejects the material, creating a coat of fibroblasts which impair transport of oxygen and other nutrients into the microcapsules and the desired cell products out of the microcapsules. Hubbell et al. U.S. Pat. No. 5,232,984, Hubbell et al. U.S. Pat. No. 5,380,536 and Hubbell U.S. Pat. No. 5,410,016 describe methods for increasing the biocompatibility of the encapsulation material.
These prior art capsules are formed either by (i) the formation of ionic cross-linking (e.g. alginate or carrageenan), (ii) a change in temperature (e.g. agarose or carrageenan), (iv) photopolymerization, or (iv) solvent precipitation (e.g. p(HEMA), Crooks, C. A., et al., J. Biomed. Mater. Res. 24:1241-1262 (1990)).
Other methods, such as the use of a surrounding device, have been employed in an attempt to permit integration of the implanted cells or cell aggregates into the body without immune rejection of the cells. Altman et al. (Diabetes 36:625-633 (1986)) have placed portions of insulinomas inside tubular membranes for implantation, and Reach et al. (Diabetes 33:752-761 (1984)) have used a U-shaped ultrafiltration design for implantation. Brauker et al. U.S. Pat. No. 5,314,471 describes a relatively small, compact implant assembly capable of inducing appropriate vascularization while providing immunoprotection for enclosed cells or cell aggregates.
SUMMARY OF THE INVENTION
The present invention provides a means for encapsulating cells and/or cellular aggregates in a very small volume of a gellable material to enable implantation of the cells and/or cellular aggregates into a patient. The capsules created are called minimum volume capsules, or MVCs, due to the small volume encapsulated. This has tremendous advantages of creating very little wasted space and being amenable to providing the immunoprotection necessary for implantation.
The invention further provides means for creating MVCs in a manner which does not damage the cells and/or cellular aggregates so that viable cells and/or cellular aggregates are made available for implantation.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows an apparatus for continuous encapsulation of biological material.
FIG. 2 shows fibroblast outgrowth from free and encapsulated islets of Langerhans.
FIG. 3a shows insulin secretion by porcine islets in response to a glucose or glucose plus IBMX stimulus; FIG. 3b shows the same for MVC encapsulated porcine islets.
FIG. 4 shows STZ-diabetes correction in athymic mice using MVC encapsulated porcine islets.
FIG. 5 shows a glucose-tolerance test on an athymic mouse implanted with rat islets in MVCs, both before and after removal of the implanted MVCs.
DESCRIPTION OF THE INVENTION
The present invention provides methods for encapsulating biological material by engulfment of the biological material by dispersed liquid droplets of water-soluble polymeric materials in an immiscible continuous phase. The dispersed liquid droplets containing biological materials are subsequently gelled to form solid polymeric particles containing encapsulated cells and/or cellular aggregates. The volume of the dispersed liquid droplets allowed to come in contact with each piece of biological material is kept to a minimum to limit the size of the microcapsule and to avoid aggregation of microcapsules.
In a preferred embodiment, a three phase system is formed, consisting of a continuous aqueous phase, a dispersed aqueous phase, and a solid phase. The aqueous phases are composed of water soluble polymers which are mutually immiscible. The solid phase is comprised of the biological material to be encapsulated.
Batch Encapsulation
Encapsulation can be performed on a batch of biological material. In the preferred embodiment, an aqueous solution to form the dispersed phase is rapidly mixed with the continuous phase to form a uniform emulsion. The dispersed phase is itself capable of gelation or contains a component capable of gelation. The biological material is then added to the emulsion with gentle mixing.
The biological material is coated with the contents of the dispersed phase by collision of liquid droplets with the biological material. Gelation is then induced.
In an alternative embodiment, an aqueous solution of biological material is added to the continuous aqueous phase. The water solution added with the biological material is dispersed in the continuous phase, leaving solid particles of biological material suspended in the continuous phase. The second aqueous liquid phase is then dispersed into the continuous phase in the form of small droplets. As with the previous embodiment, the biological material is coated with the contents of the dispersed phase by collision of liquid droplets with the biological material, and gelation is then induced.
In a third embodiment, an aqueous solution of biological material is added to the to-be-dispersed phase before dispersion. The water from the aqueous biological material solution disperses into the to-be-dispersed phase, leaving solid particles of biological material suspended in the to-be-dispersed phase. This mixture is then dispersed into the continuous phase to form small droplets. As the droplets form, excess dispersed phase material is stripped from the droplets, leaving a sufficient amount to coat the biological material. Gelation is then induced.
Continuous Encapsulation
Alternatively, encapsulation can be a continuous procedure with all components flowing together continually to create microcapsules. Both components for the continuous and dispersed phases are fed into a chamber with continuous mixing to create the emulsion. The emulsion flows through the chamber past the feed of biological material, which joins the flow. Gentle mixing is provided, either by configuration of the tubing or by external means, and engulfment of the biological material occurs. The engulfed biological material continues to flow into a curing compartment where gelation is induced.
FIG. 1 shows a device for the continuous production of MVCs. This device is optionally sterilizable in order to maintain the sterility of the biological material and the MVCs. This can be accomplished for example by assembling the apparatus aseptically from sterilized parts, such as autoclaved components, or the apparatus can be constructed of materials that allow for the system to be sterilized using steam-in-place or other sterilizing techniques.
Peristaltic or other pumps (2a and 2b) are connected to tubing (4a and 4b) through which the continuous phase and the dispersed phase materials are pumped. In-line mixer elements (6) mix the materials and create an emulsion (8). Another peristaltic or other pump (10) attached to a feed line (12) for biological material (14) pumps the biological material into the emulsion stream. Gentle mixing is provided in the stream beyond the joint (16). Engulfment occurs in the stream. The outlet (20) provides a gentle steady stream of effluent collected into a tank (22) containing physiologically compatible solution containing the curing material (24). The curing material will vary depending on the method of gelation. Optionally a light source (28) is present to provide light (30) of the appropriate wavelength for photopolymerization. Gentle stirring as by a stirrer (26) such as a magnetic stirrer prevents aggregation of nascent capsules during curing.
Engulfment
Compounds for the continuous and dispersed phases are chosen so as to create the appropriate differential in surface tension relative to the biological material. This allows the dispersed phase to engulf the biological material, while the continuous phase does not. The thermodynamic equation governing particle engulfment is as follows: for a particle (P) suspended in a continuous phase (C) coming into contact with a disperse phase (D), the interfacial tension between each of these components can be expressed in the form γ ij where γ pc , γ pd , and γ dc represent the interfacial tensions between the particle and continuous phase, the particle and discontinuous phase and the continuous and discontinuous phases respectively. The thermodynamic work of engulfment (ΔF engulf ) is the sum of the interfacial tensions formed and the interfacial tensions lost:
ΔF.sub.engulf =γ.sub.pd -γ.sub.pc -γ.sub.dc
Engulfment occurs when the Helmholtz free energy of the system is negative (ΔF engulf <0). See Omenyi, S. N. et al., J. Appl. Phys. 52:789-802 (1980).
Further, compounds for the two aqueous phases must be biocompatible. By "biocompatible" is meant materials which produce a minimal or no adverse response in the body at the concentrations used.
METHODS IN ENZYMOLOGY Vol. 228, esp. pp. 3-13, (1994) (eds.) Academic Press Limited, London, (incorporated herein by reference) provides an in depth description of methods for determining the usable combinations of polymers to induce partitioning of the biological material into the dispersed phase. Further, Table I lists a variety of polymer combinations which are effective in partitioning. Id. at 4.
For example, the continuous phase polymer can be selected from, but is not limited to, the following group: poly(ethylene glycol), poly(ethylene glycol propylene glycol), poly(vinyl alcohol), benzoyldextran, hydroxypropyl dextran, Ficoll, polyvinylpyrrolidone, poly(styrene sulfonate), DEAE-dextran and acrylic copolymers. The dispersed phase polymer can be selected from, but is not limited to, the following group: dextran, benzoyldextran, hydroxypropyl starch, poly(vinyl alcohol), maltodextrin, pullulan, poly(vinyl methyl ether), dextran sulfate, carboxymethyl dextran, poly(acrylic acid) and poly(acrylamide).
An example of a polymer combination which can be used for the present invention is the preferred embodiment of poly(ethylene glycol) (PEG) (Fluka Biochemika) in isotonic saline to create the continuous phase in combination with dextran (ICN Biomedical) in isotonic saline to create the dispersed phase. The PEG is dissolved in physiologic saline at a concentration of between 5 and 50% (w/w), preferably between 5 and 25% (w/w), more preferably between 5 and 15% (w/w), and most preferably at about 10% (w/w). The molecular weight of the PEG is between 1 and 100 kD, preferably between 1 and 40 kD, more preferably between 6 and 10 kD, and most preferably about 8 kD. The dextran is dissolved in physiologic saline at a concentration of between 5 and 50% (w/w), preferably between 5 and 25% (w/w), more preferably between 5 and 15% (w/w), and most preferably at about 10% (w/w). Molecular weight of the dextran is between 10 and 400 kD, preferably between 10 and 200 kD, more preferably between 100 and 200 kD, and most preferably about 150 kD.
Gelation
The discontinuous phase is either itself capable of gelation or includes a gellable component.
The gelling agent must be gellable under conditions which do not damage the biological material. Thus, gelation can occur for example by changing the conditions of temperature, pH or ionic environment, or by photopolymerization.
Ionic bonding of the compound to physiologically compatible ions such as Ca++ or Ba++ to form polymers is one acceptable mode. Examples of compounds capable of such gelation are acidic, water-soluble polysaccharides such as alginate, carrageenan, guar gum, xanthan gum, gum arabic, pectin and tragacanth gum. In the preferred embodiment, alginate (Pronova Biopolymer) is dissolved in the dispersed phase at a concentration of 0.4 to 4.0% (w/w), preferably 0.4 to 2.0% (w/w), more preferably 1.2 to 1.8% (w/w), and most preferably about 1.6% (w/w). Alginate high in guluronic acid content is preferred. Gelation is induced by the addition of divalent cations such as Ca++ or Ba++.
Other means of gelation such as photopolymerization are also acceptable. Hubbell et al. U.S. Pat. No. 5,410,016 (incorporated herein by reference) and Hubbell et al. U.S. Ser. No. 07/958,870 (now, U.S. Pat. No. 5,529,914) (incorporated herein by reference) describe a variety of compounds which can be photopolymerized to create a microcapsule. Examples of such compounds include macromers which are water soluble compounds and are-non-toxic to biological material before and after polymerization, and contain at least two free radical-polymerizable regions. The macromers can optionally have a biodegradable region. Examples of macromers for photopolymerization include unsaturated derivatives of poly(ethylene oxide) (PEO), PEG, poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), poly(ethyloxazoline) (PEOX), poly(amino acids), polysaccharides such as alginate, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, chitosan, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives and carrageenan, and proteins such as gelatin, collagen and albumin
The macromers are mixed with photosensitive chemicals or dyes to allow gelation by shining light of the appropriate wavelength on the engulfed biological material.
Further, mild heating which does not harm the biological material can be used for gelation. Example of a gellable material in this category is low-temperature melting agarose.
Biological Material
By "biological material" is meant mammalian tissue, cellular aggregates, individual cells, sub-cellular organelles and other isolated sub-cellular components. Examples of cells which can be encapsulated are primary cultures as well as established cell lines, including transformed cells. These include but are not limited to pancreatic islets of Langerhans, hepatocytes, parathyroid cells, foreskin fibroblasts, Chinese hamster ovary cells, beta cell insulomas, lymphoblastic leukemia cells, mouse 3T3 fibroblasts, dopamine secreting ventral mesencephalon cells, neuroblastoid cells, adrenal medulla cells, and T-cells. As can be seen from this partial list, cells of all types, including dermal, neural, blood, organ, muscle, glandular, reproductive, and immune system cells can be encapsulated successfully by this method. Additionally, proteins (such as hemoglobin), polysaccharides, oligonucleotides, enzymes (such as adenosine deaminase), enzyme systems, bacteria, microbes, vitamins, cofactors, blood clotting factors, drugs (such as TPA, streptokinase or heparin), antigens for immunization, hormones, and retroviruses for gene therapy can be encapsulated by these techniques.
Removal of Biological Material Partially Encapsulated
Fully encapsulated biological material does not adhere to tissue culture gel matrix. However, partially encapsulated biological material can be induced to adhere to the gel matrix through outgrowth of associated anchorage-dependent fibroblasts. Relying on this characteristic, an assay was developed to determine the percent of microcapsules which only partially encapsulated the biological material. Microcapsules can be plated on a suitable medium such as Matrigel (Collaborative Biomedical Products) and allowed to grow in culture conditions for a period of around two weeks. The Matrigel or its equivalent enables anchorage of the cells. Fully encapsulated biological material will remain in suspension, while partially encapsulated biological material will adhere to the gel matrix. The supernatant can be removed along with the suspended microcapsules as a means for purifying the fully encapsulated biological material from that only partially encapsulated.
Further Modifications
The microcapsules of this invention can be further modified to create additional layers and/or membranes such as by the addition of polycationic layers. These additional layers can provide added structural stability and/or permselectivity. For example, when the gelled material is a polyanionic polymer such as alginate, polylysine or other polyamines can be ionically bound to the outside to create a membrane. See Lim U.S. Pat. No. 4,352,883, Lim U.S. Pat. No. 4,391,909, Lim U.S. Pat. No. 4,409,331, Tsang et al. U.S. Pat. No. 4,663,286, Goosen et al. U.S. Pat. No. 4,673,566, Goosen et al. U.S. Pat. No. 4,689,293, Rha et al. U.S. Pat. No. 4,744,933, Rha et al. U.S. Pat. No. 4,749,620, Goosen et al. U.S. Pat. No. 4,806,355, and Hubbell et al. U.S. Pat. No. 5,380,536, incorporated herein by reference, for descriptions of methods for making such a membrane.
Alternatively, additional membranes can be created around the microcapsules without relying on interactions with the gelled material. For example, the methods of Hubbell et al., U.S. Ser. No. 07/958,870 (now, U.S. Pat. No. 5,529,914) can be utilized to create an additional photopolymerized coat around the microcapsules of this invention.
Implantation
The microcapsules are preferably gently washed and collected after gelation and any additional modifications. The encapsulated biological material can be implanted in a patient to provide compositions secreted by the encapsulated material, or to provide the encapsulated material itself. For example, with encapsulation of islets of Langerhans, the microcapsules can be implanted in a diabetic animal for treatment of diabetes through the production of insulin.
EXAMPLE 1
Batch Encapsulation of Islets of Langerhans
A batch of Islets of Langerhans was prepared for encapsulation. 100 to 50,000 islets, preferably between 5,000 and 30,000 islets, and most preferably between 15,000 and 25,000 islets were used. Islets were maintained in culture for from 0 to 72 hours, preferably between 6 and 24 hours, and most preferably overnight after isolation. Islets were pooled to a single 50 ml centrifuge tube. The islets were centrifuged to form a pellet (40 g for 4 minutes). The culture supernatant was removed and the islet pellet resuspended in isotonic saline containing 10 mM HEPES. The washing procedure was preferably repeated three times to remove excess proteins from the islets.
A sample of washed resuspended islets was removed for counting to determine the correct volume to use for the procedure. The appropriate number of washed islets were then pelleted and the supernatant replaced with a 5:1 volume ratio of 10% dextran and 1.6% alginate mixture. The islets were gently mixed in this solution. Alternatively, the pelleted islets were directly resuspended in about 1 ml isotonic saline.
A uniform emulsion containing a 20:5:1 volume ratio of 10% PEG:10% dextran:1.6% alginate was prepared in a separate 50 ml centrifuge tube by vigorous mixing using a vortex mixer or equivalent. The islets in the dextran-alginate mixture were pelleted and the supernatant removed to leave a concentrated islet suspension in about 1 ml of solution.
The freshly prepared uniform emulsion was quickly added to the islet suspension, and the tube was gently mixed using a rocking table or by hand to prevent distinct phase separation of the dextran and PEG phases. This mixing lasted for between 1 and 15 minutes, preferably between 5 and 15 minutes, and most preferably between 8 and 12 minutes.
The emulsion containing islets was then slowly poured into a 250 ml beaker containing 150 ml of gently stirred curing buffer containing 10 mM HEPES isotonic saline supplemented with barium or calcium chloride between 10 and 100 mM, preferably between 10 and 50 mM, and most preferably between 10 and 30 mM divalent metal salts. The stirring was used to prevent aggregation of the nascent capsules during ionic cross-linking and to ensure dissolution of the water-soluble dextran and PEG away from the capsules.
The nascent capsules were then allowed to settle and cure in the curing buffer for between 2 and 30 minutes, preferably between 2 and 20 minutes, most preferably between 5 and 15 minutes. The supernatant above the settled capsules was slowly decanted and the capsules were rinsed with fresh curing buffer. By repeating the process of resuspension and decanting, empty capsules can be removed from the preparation.
The resuspended capsules were transferred to a fresh 50 ml centrifuge tube and centrifuged at 40 g for 4 minutes in the cold (2° C. to 8° C.). The supernatant was removed and the capsules resuspended and washed in buffered isotonic saline. The fully cured encapsulated islets were resuspended and washed three times in culture media. The encapsulated islets were resuspended in culture media and maintained in culture using standard methods for islet culture.
EXAMPLE 2
Continuous Encapsulation of Islets of Langerhans
A batch of Islets of Langerhans is prepared for encapsulation. 100 to 50,000 islets, preferably between 5,000 and 30,000 islets, and most preferably between 15,000 and 25,000 islets are used. Islets are maintained in culture for from 0 to 72 hours, preferably between 6 and 24 hours, and most preferably overnight after isolation. Islets are pooled to a single 50 ml centrifuge tube. The islets are centrifuged to form a pellet (40 g for 4 minutes). The culture supernatant is removed and the islet pellet resuspended in isotonic saline containing 10 mM HEPES. The washing procedure is preferably repeated three times to remove excess proteins from the islets.
The islets are resuspended to a concentration of between 1,000 to 40,000 islets/ml, preferably between 5,000 and 30,000 islets/ml, and most preferably to between 18,000 and 22,000 islets/ml in an isotonic saline solution.
The apparatus for continuous encapsulation of islets is prepared as follows. Peristaltic pumps are attached to tubing such that a controlled feed of PEG at a rate of about 20 ml/min is maintained through one tube and a controlled feed of dextran or a solution containing dextran and alginate at a volume ratio of 5:1 at a rate of about 5 ml/min is maintained through the other tube. The tubes are arranged so that they join together into one channel with the PEG and dextran or dextran/alginate flows concomitantly joining together. In-line mixing elements then act on the mixture in the channel to create an emulsion wherein the PEG is in the continuous phase and the alginate and/or dextran are in the dispersed phase. An additional tube joins the channel, and islets suspended in either saline or alginate are pumped through this third tube at a rate of about 1 ml/min. The islet feed stream is gently mixed with the emulsified carrier stream through the configuration of the islet feed stream inlet into the channel; The channel outlet, provides a gentle steady stream of effluent collected into a gently stirred tank containing curing buffer composed of 10 mM HEPES isotonic saline supplemented with barium or calcium chloride between 10 and 100 mM, preferably between 10 and 50 mM, and most preferably between 10 and 30 mM divalent metal salts. The stirring was used to prevent aggregation of the nascent capsules during ionic cross-linking and to ensure dissolution of the water-soluble dextran and PEG away from the capsules.
The nascent capsules are then allowed to settle and cure in the curing buffer for between 2 and 30 minutes, preferably between 2 and 20 minutes, most preferably between 5 and 15 minutes. The supernatant above the settled capsules is slowly decanted and the capsules are rinsed with fresh curing buffer. By repeating the process of resuspension and decanting, empty capsules can be removed from the preparation.
The resuspended capsules are transferred to a fresh 50 ml centrifuge tube and centrifuged at 40 g for 4 minutes in the cold (2° C. to 8° C.). The supernatant is removed and the capsules resuspended and washed in buffered isotonic saline. The fully cured encapsulated islets are resuspended and washed three times in culture media. The encapsulated islets are resuspended in culture media and maintained in culture using standard methods for islet culture.
EXAMPLE 3
Separation of Fully Encapsulated Islets of Langerhans
To estimate the number of partially encapsulated islets, a fibroblast outgrowth assay was developed. Anchorage-dependent fibroblasts are routinely found associated with islets even after several days of culture. Encapsulated islets were plated onto Matrigel gel matrix which provides support for the rapid growth of anchorage dependent cells such as fibroblasts. Full encapsulation of an islet would prevent fibroblast outgrowth from the islet to the growth matrix, hence fibroblast only occurs from partially encapsulated islets.
Two batches of free or encapsulated islets were tested. Approximately 100 islets or encapsulated islets were counted out into tissue culture treated wells coated with Matrigel. The number of islets from which fibroblast outgrowth occurred was measured over a 2 week study period. FIG. 2 shows the percent fibroblast outgrowth of two encapsulated cultures and two unencapsulated control cultures over time. Approximately 10% of the encapsulated islets demonstrated fibroblast outgrowth, indicating approximately 90% of the islets were completely encapsulated by the method.
The fully encapsulated islets were then segregated from the partially encapsulated islets. This was accomplished by culturing the encapsulated islets on Matrigel coated tissue culture plates for between 3 and 7 days. Partially encapsulated islets demonstrated fibroblast outgrowth and were irreversibly adhered to the Matrigel by the fibroblasts. Fully encapsulated islets remained in suspension and were removed by removal of the growth medium. The capsules were then washed prior to either further culturing or implantation.
EXAMPLE 4
In Vitro Characterization of Encapsulated Islets
The ability of encapsulated porcine islets of Langerhans to respond to a change in glucose concentration was measured using a static glucose stimulation assay performed either in the presence or absence of isobutyl methyl xanthine (IBMX), a potentiator of insulin secretion in response to a glucose challenge. These results were compared to those obtained for free pig islets. The results of these assays are summarized in FIG. 3a and 3b. FIG. 3a shows the response of unencapsulated islets, while FIG. 3b shows the response of capsules encapsulated according to the invention. This figure demonstrates that the encapsulated islets are responsive to glucose concentration and secrete insulin in the same manner as unencapsulated islets.
EXAMPLE 5
In Vivo Performance of Encapsulated Islets
The ability of encapsulated porcine islets to function in vivo was assayed using diabetes correction studies with STZ-diabetic athymic mice. See Juno, A. et al., J. Clin. Invest. 48:2129-2139 (1969) for a description of STZ induced diabetes. The number of islet equivalents implanted into the kidney capsule of STZ-athymic mice, either as free or encapsulated islets, required to achieve correction was measured.
The results of these assays are presented in FIG. 4. As can be seen from the data, islets encapsulated according to the present invention are equally effective as unencapsulated islets in correcting STZ-diabetes.
The in vivo effectiveness of islets encapsulated in MVCs was further analyzed using glucose tolerance testing (GTT) in athymic mice. FIG. 5 shows the results of GTT in mice six months after implantation of rat islets in MVCs both prior to () and after (▪) explantation of the MVCs. As can be seen from the figure, the implanted MVCs were capable of maintaining glucose at appropriate levels, while after explantation of the MVCs, the blood glucose returned to diabetic levels.
The Examples included herein are not to be construed as limiting on the invention, but are provided to illustration some variations of the invention. The invention is to be limited only by the claims that follow. | The present invention provides methods and a device for producing minimal volume capsules containing viable cells or cellular aggregates. The methods and device use a two-phase aqueous emulsion system to form a dispersion of liquid capsule-forming materials in a continuous liquid phase to which is added a suspension of biological material. Alternatively, the biological material can be added to one or the other of the liquid phases. The composition of this emulsion is adjusted to promote the thermodynamically-driven process of particle engulfment by the dispersed droplets of liquid capsule-forming materials. Subsequently, the droplets engulf the biological material to form a liquid film surrounding the tissue and are converted to solid form, resulting in encapsulation of the biological material in minimum volume capsules. | 8 |
FIELD OF THE INVENTION
This invention is directed to improved coated optical elements that can be used for the transmission of below 250 nanometer (nm) electromagnetic radiation, and in particular to improved coated alkaline earth metal fluoride optical elements that thereby have greater durability and improved transmissivity for use in the area of optical lithography; and additionally to a method for making such optical elements.
BACKGROUND OF THE INVENTION
The use of high power lasers, for example, those with pulse energy densities (fluence) above 20 mJ/cm 2 , with pulse lengths in the low nanosecond range, can degrade the optics used in laser lithography systems. T. M. Stephen et al., in their article “Degradation of Vacuum Exposed SiO2 Laser Windows” SPIE Vol. 1848, pp. 106–109 (1992), report on the surface degradation of fused silica in Ar-ion laser. More recently, it has been noticed that there is optical window surface degradation in high peak and average power 193 nm excimer lasers using window materials made from substances other than silica. It is a concern that such degradation will be more severe when existing optical materials are used in 157 nm laser systems. While some solutions, for example, such as using MgF 2 as the window or lens material for existing 193 nm laser systems have been proposed, it is believed that such materials will also experience surface degradation with time, leading to the requirement that the expensive windows be periodically replaced. It is further believed that the problem with window degradation will be exacerbated with the advent of laser systems operating at wavelengths below 193 nm. In addition, the use of MgF 2 as a window material, while it might be successful from a mechanical viewpoint, presents a problem of color center formation that is detrimental to transmission performance of the laser beam.
Excimer lasers are the illumination sources of choice for the microlithographic industry. While ionic materials as such as crystals MgF 2 , BaF 2 and CaF 2 are the materials of choice for excimer optical components due to their ultraviolet transparencies and to their large band gap energies, the preferred material is CaF 2 . However, crystals of CaF 2 and the optical elements made from CaF 2 , are difficult to optically polish. Furthermore, polished but uncoated surfaces of CaF 2 are susceptible to degradation when exposed to powerful excimer lasers operating in the deep ultraviolet (“DUV”) range, for example at 248 and 193 nm and the vacuum ultraviolet (“VUV”) range, for example at 157 nm. For lasers operating at 193 nm, 2 KHz or 4 KHz, with pulse energy densities of 20–40 mJ/cm 2 , the surfaces or the optical elements made from these ionic materials are known to fail after only a few million laser pulses. The cause of the damage is thought to be fluorine depletion in the top surface layers of the polished surface. U.S. Pat. No. 6,466,365 (the '365 patent) describes a method of protecting metal fluoride surfaces, such as CaF2, from degradation by use of a vacuum deposition, of a silicon oxyfluoride coating/material. While for the moment this is a reasonable solution, the microlithographic industry constantly demands more performance from excimer sources, and consequently from optical components used in connection with Excimer laser based systems. Therefore, in view of the expected increased industry demands for improved laser performance, it is desirable to find a solution to the optical element degradation problem that will either eliminate the problem or will greatly extend the durability, and consequently the length of time, that existing and future optical components can be used.
SUMMARY OF THE INVENTION
In one aspect, the invention is directed to coated optical elements made from metal fluoride single crystals of formula MF 2 , where M is calcium, barium, magnesium, or strontium, or mixtures of the foregoing, that are used in below 250 nm lithography, and particularly in below 200 nm lithography.
In another aspect the invention is directed to a coated alkaline earth metal fluoride single crystal optical element suitable for use in optical lithography systems using below 200 nm electromagnetic radiation, said optical element comprising a shaped metal fluoride single crystal having a selected coating material on the element surfaces through which said electromagnetic radiation enters and exits; wherein said coating is on a surface that has been substantially cleaned of the quasi-Bielby layer present on the surface prior to the application of the coating material.
In another aspect the invention is directed to coated CaF 2 optical materials that are useful in laser lithography. In particular embodiments, the invention is directed to coated optical path materials for use as windows, lenses and other optical elements below 250 nm, as especially below 200 nm, laser lithography.
The coating material used in accordance with the invention can be any material being transmissive in the X-ray, infrared, UV and visible regions of the electromagnetic spectrum. For applications operating at wavelengths below 250 nm, the preferred coating materials for metals fluoride optical elements, as especially CaF 2 optical elements, are silicon nitride, silicon oxynitride, MgF 2 , doped high purity silica and fluorine doped high purity silica. The coatings are typically deposited on the surface of the optical material by methods known in the art; for example, vapor deposition, chemical vapor deposition (“CVD”), plasma enhanced chemical vapor deposition (“PECVD”), and other “plasma” deposition methods including sputter deposition.
The invention is further directed to a method of making a coated metal fluoride single crystal optical element that is resistant to laser-induced damage by a below 250 nm laser beam, and especially by a below 200 nm laser beam. The method includes the steps of providing an uncoated alkaline earth metal fluoride crystal or element: cutting, grinding and polishing the surface of the crystal or element; etching the cut, ground and polished surface to remove impurities present on the surface in a quasi-Bielby layer; and coating the metal fluoride element surface with a coating of a selected material to thereby form a coated material resistant to laser induced damage. In particular, the invention is directed to CaF 2 optical elements made according to the foregoing method.
The invention is further directed to a method for making an alkaline earth metal fluoride single crystal optical element suitable for use in optical lithographic systems using below 250 nm electromagnetic radiation, said method comprising the steps:
obtaining an alkaline-earth metal fluoride single crystal,
shaping the single crystal into an optical element using, as necessary, cutting and grinding steps,
polishing the surfaces of the shaped element through which the below 250 nm electromagnetic radiation enters and exits,
etching the polished surfaces to remove the quasi-Bielby layer resulting from the polishing,
coating the etched surface with a selected optical material, and
polishing the coated surfaces to thereby form a coated alkaline earth metal fluoride single crystal optical element;
wherein said alkaline earth metal is selected from the group consisting of calcium, barium, magnesium and strontium, or mixtures of any of the foregoing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the morphology of a polished CaF 2 surface
FIG. 2 illustrates the precipitated layer and the DI water revealed SSD of a polished CaF 2 .
FIG. 3 illustrates the behavior of polished CaF2 with DI water.
FIG. 4 illustrates the measured percent transmission through a polished CaF 2 crystal before and after washing with DI water.
FIG. 5 a illustrates a polished CaF 2 surface before washing with DI water, the Bielby layer being present.
FIG. 5 b illustrates a polished CaF 2 surface after washing with DI water, the Bielby layer having been removed.
FIG. 6 illustrates the morphology of a CaF 2 crystal after water washing and deposition of a coating material according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following description and in the Figures, CaF2 is used as the exemplary alkaline earth metal fluoride single crystal material that is made into a coated optical element in accordance with the invention. However, it should be remembered that the invention applies to all optical elements made of alkaline earth metal fluorides or elements made from mixtures of such alkaline earth metal fluorides. In addition, the invention applies to all optical element surfaces subjected to cutting, grinding and polishing; for examples the two faces of a laser window or lens.
The invention is directed to coated optical elements made from alkaline earth metal fluorides, and especially to coated optical elements made from calcium fluoride, CaF 2 , or a mixture of calcium fluoride with one or more other alkaline earth metal such as barium, magnesium or strontium; and to a method of making such elements. The optical elements according to the invention have improved transmission properties and durability.
Metal fluoride single crystals for use in optical lithography method are formed into optical element by cutting, grinding and polishing the surface of a crystal blank. When the metal fluoride is calcium fluoride, or a mixture of calcium fluoride and another alkaline earth metal, it has been found that there is a small but measurable absorption in the polished surfaces of elements made of such crystals. When the surfaces of such elements are subjected to the powerful laser beams, for example, in optical lithographic processes, this small adsorption leads to significant heating and thermal gradients in the optical element. Temperature rises in a CaF 2 or other metal fluoride optical element can accelerate damage to the element through a mechanism believed to involve fluorine loss from the element. As a result of this damage the element has a shortened lifetime and powerful wavefront distortions occur particularly for CaF 2 due to the fact that it has a large coefficient of thermal expansion. Wavefront distortion degrades optical performance in high precision lens systems such as used in optical lithographic systems. The invention described herein removes or minimizes the substances that cause the absorption and results in surfaces that have improved transmission performance and durability when used for wavelengths below 200 nanometers. This will result in the optical elements having an improved lifetime when used in excimer laser systems that operate at high repetition rates and energy densities.
CaF 2 is generally the preferred optical material for DUV and VUV excimer based microlithography due to its isotropic properties and its availability in as a high purity material that can be formed into optical elements (components). Generally, the optical axis of the component is selected as the <111> direction, where the <111> direction is perpendicular to the (111) plane which is the preferred cleavage plane for the material. Like other ionic crystals such as MgF 2 and BaF 2 , CaF 2 is prone to chipping and cleavage during mechanical cutting and grinding operations, and is subject to thermal shock. The mechanical operations necessary to shape the optic leave behind deep fractures, known as sub-surface damage (“SSD”), that are very difficult to remove by subsequent fine grinding and polishing operations. Ellipsometric techniques for SSD evaluation of polished crystal surfaces have been developed [see J. Wang et al., “Surface characterization of optically polished CaF 2 crystal by quasi-Brewster angle technique”, SPIE Proc., Vol. 5188 (2003), pages 106–114].
In general, when optical blanks are shaped, the sawing, grinding and shaping operations are done using diamond and/or alumina based abrasives and saws. Subsequently, the resulting shaped element is subjected to several polishing steps using increasingly finer abrasives to remove specified thicknesses of material at each step. This methodology was developed over the years for amorphous materials such as glass or HPFS (high purity fused silica), and has been found to be useful for crystalline materials, for example, CaF2, using magneto-rheological finishing (MRF) methods. When we used ellipsometry to evaluate the morphology of surfaces polished by such techniques, the ellipsometric analysis revealed that considerable SSD often remains. Hard abrasives, for example, diamond, remove material from the substrate surface by brittle fracture. Considerable force is exerted down into the crystal, causing additional fracturing, or the further propagation of existing fractures from earlier operations, as chunks of material are dislodged. The result is a rough top surface with deep fractures.
Polishing slurries are typically water based, and CaF 2 has a small but finite solubility in water. At some point, sufficient CaF 2 becomes dissolved in the slurry and precipitates back onto the substrate, along with small particulates removed in polishing, thus filling in voids and producing a smooth top surface. For glass or silica polishing, this smooth top layer containing the particulates is commonly known as the Bielby layer. While in the case of glass and silica very little of the glass or silica is actually dissolved in the slurries, this is not the case for CaF 2 polishing. In the case of CaF 2 , while the top surface of the polished CaF 2 looks quite smooth, it is not single crystal material, but instead a contaminated layer comprised mostly of polycrystalline CaF 2 . The precipitate layer, which we may call the quasi-Bielby layer, contains various contaminants from the slurry, notably metallic impurities, in addition to the polycrystalline CaF 2 . FIG. 1 illustrates the schematic morphology of typical polished CaF 2 element having a top surface 20 of μ-roughness (RMS); an SSD region 24 ; a precipitate layer 22 (the quasi-Bielby layer) located between the top surface 20 and the SSD region 24 ; an undisturbed single crystal area 28 ; and a region of crystal dislocation 26 located between the SSD region 24 and the undisturbed area 28 .
In accordance with the invention, the quasi-Bielby layer on optical element surfaces that have been polished is removed by treatment using an etching method such as water washing, ion milling, ultrasonic cleaning, or dissolved by other appropriate solvents. In the case of CaF2, the etching is easily done using deionized water. FIG. 2 illustrates a polished CaF 2 surface that has been half submerged in deionized water to reveal the quasi-Bielby layer 30 and the SSD structure 32 . Once the quasi-Bielby layer has been removed, the “polished and etched” surfaces of the element are coated with a selected material as taught in U.S. Pat. No. 6,466,365 (the '365 patent) or other coating material known in the art to be useful for coating element operating at wavelengths below 200 nm, to produce an optical element that has improved durability over that of the '365 patent.
We have found that the quasi-Bielby layer of a CaF 2 element is quite porous, quite water soluble, and absorbing to wavelengths below 200 nm. FIG. 3 illustrates the measured dissolution rate of the quasi-Bielby layer of a polished CaF 2 crystal in deionized water at room temperature. In the limit, the dissolution rate of a polished surface approaches that of a cleaved surface which has been measured at 1.5 nm/hour. The dissolution rate is proportional to the surface area of the material; in this case, the CaF 2 surface undergoing deionized water treatment. Dissolution of the quasi-Bielby layer reveals the subsurface structure (SSD). The deionized water removal rate, R(z), of the quasi-Bielby layer to various depths is represented by Equation (1),
R ( z )= R o +R s e −z/D (1)
where R o is the bulk dissolution rate of CaF 2 , as measured from a cleaved sample. The surface effect of the precipitated layer originating from optical polishing described by R s and D; the former being the dissolution rate at the surface (that is, z=0) and the latter being the characteristic depth of the precipitated layer. R s and D can be determined by fitting the experimental data. As noted above, Equation (1) is proportional to the effective surface area or porosity distribution.
The experimental results shown in FIG. 3 were obtained at room temperature. In order to obtain accurate dissolution rate distribution, the polished surface was used as the reference for the determination of the removal depth. As a result, the measured removal rate is an average or mean rate over the total removed region as described by in Equation (2). The results obtained using Equations (1) and (2) are shown in FIG. 3 .
R
_
(
z
)
=
1
z
∫
0
z
R
(
z
)
ⅆ
z
=
R
o
+
R
s
D
z
(
1
-
ⅇ
-
z
/
D
)
(
2
)
In addition to being a refuge for microcrystals of CaF 2 removed from the crystal surface and for the polishing agent, the quasi-Bielby layer is also a refuge for contamination by impurities from the slurry. This was verified by ToF-SIMS analysis. These impurities lead to absorption by the element when used in a laser system. Absorption in polished CaF 2 surfaces has been reported at 248 nm by S. Gogall et al. [“Laser damage or CaF 2 (111) surfaces at 248 nm”, Appl. Surface Science, 96098 (1996), pages 332–340], and will be worse at sub-200 nm wavelengths. FIG. 4 illustrates the measured transmission of a well polished CaF 2 crystal before and after treatment with deionized water in accordance with the invention to remove the quasi-Bielby layer that resulted from the polishing procedure on all polished surfaces. The transmission was measured in the range of 150 to 248 nm. The transmission increased after the quasi-Bielby layer was removed; thus demonstrating the absorption within quasi-Bielby layers. It should be specially noted that as the wavelength decreases, the difference between deionized water etched sample, and the non-etched sample becomes greater; thus demonstrating the significant effect that the quasi-Bielby layer has on transmission properties as wavelength decreases. FIG. 5A illustrates a polished CaF 2 crystal surface before treatment with deionized water and FIG. 5 b illustrates one after deionized water treatment. The deionized water treatment removes the quasi-Bielby layer and reveals the SSD.
The method of the invention can be used with a metal fluoride single crystal grown by any method known in the art; for example, the Bridgman-Stockbarger method. Methods of growing and/or annealing single crystals are also described in U.S. Pat. Nos. 6,395,657 B2, 6,309,461 B1, 6,562,126 B2; 6,332,922 B1; 6,620,347; 6,238,479 B1; and other patents and technical literature known to one skilled in the art. In addition, the method of the invention can be used with a single crystals having any orientation; for example, <100>, <110> and <111> oriented crystals. Once the single crystal was grown, it was cut and polished by methods known in the art; for example, using a diamond blade to cut the crystal to the proper shape, a diamond grinding powder or wheel to give it a final shape, and then polishing the surfaces using any polishing method known in the art; for example, using aluminum oxide as a polishing agent. While the grinding and polishing should be carried out in a manner so as to minimize SSD, it was not necessary to focus on obtaining very smooth top surface roughness (TSR). If the optical material is CaF 2 , its polished surfaces are next soaked in deionized water or otherwise etched (for example, etched using ion milling) for sufficient time to allow complete dissolution, or removal, of the precipitated layer that results from the polishing step. The water etching can be done by soaking the surface in deionized water at room temperature for a time in the range of 5 to 120 minutes, depending upon the polishing methods used, or by spraying the surface with a gentle stream of deionized water such as may come from a shower head or a kitchen sink water sprayer. Soaking is the preferred method. If the optical material is barium or magnesium fluoride, ion milling or a similar technique using an appropriate solvent is the preferred method of removing the quasi-Bielby layer from the optical element due to the low solubility of these materials in water.
After optical element's surface was etched with deionized water, or otherwise etched, the surface was cleaned using one of the generally accepted methods used prior to vacuum deposition of a material. Such methods include but are not limited to acetone or alcohol drag wipe, alcohol or acetone rinse followed by drip dry or blow dry using filtered air or dry nitrogen. In the subsequent step a dense coating layer as described in U.S. Pat. No. 6,466,365, or otherwise known in the art to be useful for use with optical elements operating at wavelengths below 250 nm, was deposited on the cleaned surfaces of the optical element. Such coating materials include high purity silicon dioxide, silicon nitride, silicon oxynitride, magnesium fluoride, aluminum oxide, fluorine-doped high purity silica and high purity silica doped with a substance other than fluorine such as, for example, aluminum. High purity oxide materials are preferred and fluorine-doped high purity silica is the particularly preferred coating agent. The coating layer was deposited to a thickness in the range of 10 to 10,000 nm. The deposited film replicates the rather large micro-roughness of the etched MgF 2 or BaF 2 surface, or deionized water etched CaF 2 surface. The deposited coating was then optically polished to achieve the desired smoothness. In the case of CaF 2 , the 0.3 nm rms of the original polished element was re-achieved, but now without the contamination carried by the quasi-Bielby layer. Since there is normally a slight index of refraction difference between the metal fluoride substrate, and the deposited film, care must be taken to control the amount of coating thickness removal in this final polishing step. The desired thickness of the remaining deposition being generally integral multiples of quarter wave optical thickness for the wavelength of use.
In an embodiment of the invention, the quasi-Bielby is removed as described above and the elements are coated as described in the preceding paragraph using the same coating materials. However, after the coating is applied, the element is used as-is in an optical lithography system, and particularly in the laser portion of the lithography system.
FIG. 6 illustrates the morphology of the coated single crystal of the invention. These crystals are produced according to the method of the invention for producing smooth, transparent surfaces on single crystals of metal fluorides of formula MF 2 , where M is calcium, barium, magnesium or strontium, or a mixture of any of these in any proportion. The quasi-Bielby layer was first removed using an etching method such as deionized water etch in the case of CaF 2 or ion milling in the case of BaF 2 and MgF 2 . A thick layer of the selected coating material was then deposited on the surface of the etched optical element. The deposited oxide coating 40 replicates the TSR of the underlying crystal. The deposited layer is then optically polished or ion milled to a surface roughness typically in the range of 0.1–0.4 nm rms as measured by AFM (atomic force microscope). The vacuum deposited layer 44 replaces the quasi-Bielby layer 20 illustrated in FIG. 1 . In FIG. 6 , numeral 46 represent the underlying crystal with SSD and numeral 48 is directed to the underlying bulk crystal.
Finally, it is known that laser damage in optical surfaces is more readily initiated at the sharp edges of a surface since the electric field strengths increase in such locations. A further embodiment of the invention is to ion mill a sufficient amount from the deposited film surface (either polished or unpolished). This milling removes any surface contaminants and in addition anneals (heals) the fine structure of the surface. This annealing effect after ion milling was confirmed by power spectral density (PSD) calculations from AFM measurements of the surface.
The present invention has been described in general and in detail by way of examples. Persons skilled in the art understand that the invention is not limited necessarily to the specific embodiments disclosed. Modifications and variations may be made without departing from the scope of the invention as defined by the following claims or their equivalents, including equivalent components presently known, or to be developed, which may be used within the scope of the present invention. Hence, unless changes otherwise depart from the scope of the invention, the changes should be construed as being included herein. | The invention is directed to improved coated metal fluoride single crystal optical elements suitable for use in below 250 nm optical lithography, and particularly below 200 nm lithography. The coated elements of the invention can be lenses, windows, prisms and other elements used in lithographic methods, including the laser sources used therein. The invention is also directed to a method of removing the quasi-Bielby layer formed when a shaped optical element is polished. Removal of the quasi-Bielby layer prior to coating results in improved durability and optical transmission characteristics of the coated lenses. The coating material can be any material that does not impede the transmission of below 250 nm electromagnetic radiation. Fluorine doped silicon dioxide is the preferred coating material. | 6 |
This application is a continuation of application Ser. No. 739,424, filed on Aug. 2, 1991, now abandoned, which is a continuation of Ser. No. 520,620 filed on May 8, 1990, now U.S. Pat. No. 5,042,010 which is a continuation of Ser. No. 358,262 filed on May 30, 1989, now U.S. Pat. No. 4,924,439, which is a continuation of Ser. No. 121,914 filed on Nov. 17, 1987, now U.S. Pat. No. 4,858,189, which is a continuation of Ser. No. 701,226 filed on Feb. 13, 1985, now U.S. Pat. No. 4,713,796.
FIELD OF THE INVENTION
The present invention relates to a semiconductor integrated circuit in which memory cells are integrated on a large scale.
BACKGROUND OF THE INVENTION
A well-known type of semiconductor integrated circuit in which memory cells are integrated on a large scale (hereinbelow termed the "semiconductor memory") is the so-called RAM. The RAM (random access memory) is a device capable of storing information temporarily and reading it out when required. This type of memory is also called a "read/write memory".
Typically, a RAM includes memory cells which store information, an address circuit which externally selects a specified memory cell, and a timing circuit which controls the reading and writing of information.
In a RAM, a plurality of memory cells are arranged in the shape of a matrix. The operation of selecting a desired memory cell from among the plurality of memory cells is performed by selecting an intersection point in the matrix. The access time is therefore constant irrespective of the position (addresses) of the selected memory cells within the matrix.
RAMs are broadly classified into two sorts; bipolar RAMs and MOSRAMs.
The bipolar RAM has the following merits:
(1) As compared with the MOSRAM, it operates faster.
(2) The operation of the memory cell is of the static type, and the controls of timings, etc. are simple.
On the other hand, the bipolar RAM has the following demerits:
(3) As compared with the MOSRAM, it exhibits a higher power consumption (especially when it does not operate).
(4) As compared with the MOSRAM, it requires a more complicated manufacturing process and is more difficult to attain a high density of integration.
Bipolar RAMs are presently generally classified into the two types of the TTL type and the ECL type, depending upon differences in input/output levels. The access time (reading time) of the bipolar RAM of TTL interface falls within a range of 30-60 (nsec.), while the access time of the bipolar RAM of ECL interface falls within a range of 4-35 (nsec.).
Accordingly, bipolar RAMs are applied to various memory systems where high speed operations are required.
Meanwhile, when compared with the bipolar RAM, the MOSRAM is simpler in structure and in the manufacturing process. It is also more advantageous in terms of power consumption, storage density and price. Therefore, it is used in fields which do not require high speed operations.
MOSRAMs are classified into the dynamic type and the static type.
The dynamic type MOSRAM has its memory cell composed of a comparatively small number of transistors, namely, 1-3 transistors per bit (1-3 transistors/bit). With an identical chip area, therefore, the bit density becomes higher than that of the static type MOSRAM to be described later.
In the dynamic MOSRAM, information is stored as charges in a capacitance within the memory cell. Since the charges stored in the capacitance are discharged due to a leakage current, etc., the information of the memory cell needs to be read out within a predetermined period of time and to be rewritten again (i.e., refreshed).
On the other hand, in the static MOSRAM, a flip-flop circuit which is usually composed of 6 elements is used as the memory cell. For this reason, the refresh which is required in the dynamic MOSRAM is not necessary.
The access time of the dynamic MOSRAM falls within a range of 100-300 (nsec.), while the access time of the static MOSRAM falls within a range of 30-200 (nsec.). Thus, it can be seen that the access time of the MOSRAM is a larger value when compared with that of the bipolar RAM.
Meanwhile, owing to improvements in photolithographic technology, reduction in the element dimensions of MISFETs within a semiconductor integrated circuit has been promoted. In IEEE Journal of Solid-State Circuit, Vol. SC-17, No. 5, pp. 793-797, issued in October 1982, there is contained a static MOSRAM of 64 kbits which employs wafer processing techniques based on design rules of 2 (μm) and which exhibits an access time of 65 (nsec.), an operating power consumption of 200 (mW) and a stand-by power consumption of 10 (μW).
Meanwhile, as an example of the bipolar RAM of the ECL type, an ECL type bipolar RAM of 4 kbits which exhibits an access time of 15 (nsec.) and a power consumption of 800 (mW) is manufactured and sold by Hitachi, Ltd. under the product name "HM100474-15".
As explained above, there has been a definite technical trend to enlarge the storage capacity of semiconductor memories which has taken place in the increments of 1 kbit, 4 kbits, 16 kbits, 64 kbits, 256 kbits, 1 Mbit, . . . , quite independently of the features of the bipolar RAM of high speed and high power consumption and the features of the MOSRAM of low speed and low power consumption.
At the present time, when the power consumption of the semiconductor memory and the present-day photolithographic techniques determining the element dimensions of bipolar transistors are taken into consideration, the storage capacity of the bipolar RAM will be limited to 16 kbits.
Meanwhile, with the enlargement of the storage capacity of the semiconductor memory (particularly, at and above 64 kbits), the area of a semiconductor chip increases, and the signal line of the address circuit of the RAM is arranged over a long distance on the semiconductor chip of large area. When the length of the signal line of the address circuit lengthens, naturally the stray capacitance of the signal line increases, and also the equivalent distributed resistance of the signal line increases. When, for the purpose of microminiaturization, the wiring width of the signal line of the address circuit is established as 2 (μm) or less by improving photolithography, the equivalent distributed resistance of the signal line increases more. In addition, since the fan-out of each circuit enlarges with the increase of the storage capacity, a load capacitance attributed to the gate capacitance of a MOSFET at the succeeding stage becomes high. Accordingly, in the 64-kbit MOSRAM which employs the photolithography of 2 (μm) and whose address circuit is entirely constructed of CMOSFETs, the access time of addresses will be limited to 30 (nsec.).
The present invention has been made by the inventors in developing a semiconductor memory which has an access time equivalent to that of an ECL type bipolar RAM and a power consumption equivalent to that of a static MOSRAM.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a semiconductor memory of high speed and low power consumption.
The above and other objects and novel features of the present invention will become apparent from the description of the specification and the accompanying drawings.
SUMMARY OF THE INVENTION
An outline of a typical embodiment disclosed in the present application to achieve the above and other objects will be briefly explained below.
In an address circuit, a timing circuit, etc. within a semiconductor memory, an output transistor for charging and discharging a signal line of relatively great length and an output transistor of large fan-out are constructed of bipolar transistors. On the other hand, logic circuits for executing logic processing, for example, inversion, non-inversion, NAND and NOR operations are constructed of CMOS circuits.
The logic circuit constructed of the CMOS circuit has low power consumption, and the output signal of this logic circuit is transmitted to the signal line of relatively great length through the bipolar output transistor of low output impedance. Since the output signal is transmitted to the signal line by the use of the bipolar output transistor having low output impedance, the dependence of the signal propagation delay time upon the stray capacitance of the signal line can be diminished. Therefore, using the arrangement of the present invention, the object of providing a semiconductor memory of low power consumption and high speed can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show a block diagram showing the internal arrangement of a static RAM according to one embodiment of the present invention;
FIGS. 2A and 2B show a block diagram showing an address buffer ADB and row decoders R-DCR0, R-DCR1, R-DCR2 in FIG. 1 in greater detail;
FIGS. 3A and 3B show a block diagram showing the address buffer ADB, a column decoder C-DCR1, etc. in FIG. 1 in greater detail;
FIG. 4 is a circuit diagram showing a quasi-CMOS non-inverting/inverting circuit for use in the present invention;
FIG. 5 is a circuit diagram showing a quasi-CMOS 3-input NAND circuit for use in the present invention;
FIG. 6 is a circuit diagram showing a pure CMOS 3-input NAND circuit for use in the present invention;
FIG. 7 is a circuit diagram showing a quasi-CMOS 2-input NOR circuit for use in the present invention;
FIG. 8 is a circuit diagram showing a pure CMOS 2-input NOR circuit for use in the present invention;
FIG. 9 is a circuit diagram showing a pure CMOS 2-input NAND circuit for use in the present invention;
FIG. 10 is a circuit diagram showing a quasi-CMOS inverter for use in the present invention;
FIGS. 11A and 11B show a circuit diagram showing a sense amplifier selector circuit SASC and an internal control signal generator circuit COM-GE in FIG. 1 in greater detail;
FIG. 12 is a circuit diagram showing a sense amplifier SA1, a data output intermediate amplifier DOIA, a data output buffer DOB, etc. in FIG. 1 in greater detail;
FIG. 13 is a circuit diagram showing a data input buffer DIB, a data input intermediate amplifier DIIA1, etc. in FIG. 1 in greater detail; and
FIG. 14 is a diagram of the signal waveforms of the various parts of the static RAM of the embodiment shown in FIGS. 1 to 13, in a read cycle and a write cycle.
DETAILED DESCRIPTION
Now, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows the internal arrangement of a static RAM which has a storage capacity of 64 kbits and the input/output operation which is executed in single bit units. Various circuit blocks enclosed with a broken line IC are formed in a single silicon chip by semiconductor integrated circuit technology.
The static RAM of the present embodiment includes four matrices (memory arrays M-ARY1 to M-ARY4) each having a storage capacity of 16 kbits (=16384 bits), thereby to have a total storage capacity of 64 kbits (more specifically 65536 bits). The four memory arrays M-ARY1 to M-ARY4 have arrangements similar to each other, and each of them has memory cells arranged in 128 rows×128 columns.
An address circuit for selecting a desired memory cell from the memory arrays each having the plurality of memory cells is constructed of an address buffer ADB, row decoders R-DCR0, R-DCR1 and R-DCR2, column decoders C-DCR1 to C-DCR4, column switches C-SW1 to C-SW4, etc.
Although not especially restricted, a signal circuit which handles the reading and writing of information is constructed of a data buffer DIB, data input intermediate amplifier D-IIA1-D-IIA4, a data output buffer DOB, a data output intermediate amplifier DOIA, and sense amplifiers SA1-SA16.
Although the invention is not especially restricted thereto, a timing circuit for controlling the operations of reading and writing information is constructed of an internal control signal generator circuit COM-GE and a sense amplifier selector circuit SASC.
A decode output signal which is obtained on the basis of address signals A 0 -A 8 is transmitted from the row decoder R-DCR1 or R-DCR2 to any of row-group address selection lines (word lines WL11-WL1128, WL21-WL2128, WR11-WR1128 and WR21-WR2128). Among the address signals A 0 -A 8 , those A 7 and A 8 are used for selecting one memory matrix from among the four memory matrices M-ARY1 to M-ARY4.
The address buffer ADB receives the address signals A 0 -A 15 , and forms internal complementary address signals a 0 -a 15 based on them. The internal complementary address signal a 0 is composed of an internal address signal a 0 which is inphase with the address signal A 0 , and an internal address signal a 0 whose phase is inverted to that of the address signal A 0 . The remaining internal complementary address signals a 1 -a 15 are similarly composed of internal address signals a 1 -a 15 and internal address signals a 1 -a 15 .
Among the internal complementary address signals a 0 -a 15 formed by the address buffer ADB, those a 7 , a 8 and a 9 -a 15 are supplied to the column decoders C-DCR1 to C-DCR4. The column decoders C-DCR1 to C-DCR4 decode these internal complementary address signals, and supply selection signals (decode output signals) obtained by the decoding, to the gate electrodes of switching insulated-gate field effect transistors (hereinbelow termed "MISFETs") Q 1001 , Q 1001 , Q 1128 , Q 1128 , Q 2001 , Q 2001 , Q 3001 , Q 3001 , Q 4001 and Q 4001 within the column switches C-SW1 to C-SW4.
Among the word lines WL 11 -WL 1128 , WL 21 -WL 2128 , WR 11 -WR 1128 and WR 21 -WR 2128 , one appointed by the combination of the external address signals A 0 -A 8 is selected by the row decoders R-DCR1 and R-DCR2 described above. One complementary data line pair appointed by the combination of the external address signals A 7 , A 8 , and A 9 -A 15 is selected from among a plurality of complementary data line pairs D 1001 , D 1001 -D 1128 , D 1128 ; D 2001 , D 2001 -D 2128 , D 2128 ; D 3001 , D 3001 -D 3128 , D 3128 ; and D 4001 , D 4001 -D 4128 , D 4128 by the column decoders C-DCR1 to C-DCR4 and the column switches C-SW1 to CSW4 described above. Thus, the memory cell M-CEL which is located at the intersection point between the selected word line and the selected complementary data line pair is selected.
In the reading operation, switching MISFETs Q 1 Q 1 -Q 4 , Q 4 , Q 8 , Q 8 , Q 12 , Q 12 , Q 16 and Q 16 are brought into "off" states by a control signal which has been delivered from the internal control signal generator circuit COM-GE, though this is not especially restrictive. Thus, common data lines CDL 1 , CDL 1 -CDL 4 , CDL 4 and write signal input intermediate amplifiers DIIA1-DIIA4 are electrically isolated. The information of the selected memory cell is transmitted to the common data lines through the selected complementary data line pair. The information of the memory cell transmitted to the common data lines is sensed by the sense amplifier, and is delivered out through the data output intermediate amplifier DOIA as well as the data output buffer DOB.
In the present embodiment, sixteen sense amplifiers are provided. Among these sense amplifiers SA1-SA16, one sense amplifier, i.e., the sense amplifier whose input terminals are coupled to the selected complementary data line pair through the common data lines, is selected by a sense amplifier selection signal from the sense amplifier selector circuit SASC, and it executes the sensing operation.
In the writing operation, the switching MISFETs Q 1 , Q 1 -Q 4 , Q 4 , Q 8 , Q 8 , Q 12 , Q 12 , Q 16 and Q 16 are brought into "on" states by the control signal from the internal control signal generator circuit COM-GE. In a case where the column decoder C-DCR1, for example, has brought the switching MISFETs Q 1001 and Q 1001 into "on" states in accordance with the address signals A 7 -A 15 , the output signal of the data input intermediate amplifier DIIA1 is transmitted to the complementary data line pair D 1001 , D 1001 through the common data line pair DCL1, CDL1 and the MISFETs Q 1 , Q 1 , Q 1001 , Q 1001 . If, on this occasion, the word line WL11 is selected by the row decoder R-DCR1, information corresponding tot he output signal of the data input intermediate amplifier DIIA1 is written into the memory cell which is disposed at the intersection point between the word line WL11 and the complementary data lines D 1001 , D 1001 .
Although not especially restricted thereto, the common data line pair DCL1 and CDL1 is composed of four sets of common data line pairs (subcommon data line pairs) in the present embodiment. Among these four sets of common data line pairs, two sets of common data line pairs are shown in the figure. Likewise to the illustrated common data line pairs, the remaining two sets of common data line pairs are coupled to the data input intermediate amplifier DIIA1 through the switching MISFETs Q 2 , Q 2 and Q 3 , Q 3 respectively. The input terminals of one sense amplifier, and one input and output electrode of each of the 32 sets of switching MISFETs are coupled to each of the four sets of common data line pairs. That is, the input terminals of the sense amplifier SA1 and the input and output terminals of the switching MISFETs Q 1001 , Q 1001 -Q 1032 , Q 1032 are coupled to the first common data line pair; the input terminals of the sense amplifier SA2 and the input and output terminals of the switching MISFETs Q 1033 , Q 1033 -Q 1064 , Q 1064 are coupled to the second common data line pair; the input terminals of the sense amplifier SA3 and the input and output terminals of the switching MISFETs Q 1065 , Q 1065 -Q 1096 , Q 1096 are coupled to the third common data line pair; and the input terminals of the sense amplifier SA4 and the input and output terminals of the switching MISFETs Q 1097 , Q 1097 -Q 1128 , Q 1128 are coupled to the fourth common data line pair. In the writing operation, the four sets of common data line pairs are electrically coupled to each other through the switching MISFETs Q 1 , Q 1 -Q 4 , Q 4 , whereas in the reading operation, they are electrically isolated from each other. Thus, it is possible in the reading operation to reduce stray capacitances which are coupled to the input terminals of the sense amplifier, so that enhancement in the speed of the reading operation can be achieved. In the reading operation, only the sense amplifier having its input terminals coupled to the subcommon data line pair to which the information from the selected memory cell has been transmitted through the switching MISFETs is selected to execute the sensing operation. Each of the other common data line pairs CDL2, CDL2-CDL4, CDL4 has an arrangement similar to that of the common data line pair CDL, CDL1 described above.
Although, in the present embodiment, the common control signal WECS is supplied to the switching MISFETs Q 1 , Q 1 -Q 4 , Q 4 , Q 8 , Q 8 , Q 12 , Q 12 , Q 16 and Q 16 , the selection signals from the column decoders may well be supplied to the respective switching MISFETs. Thus, it is possible in the writing operation to reduce the load capacitance of the data input intermediate amplifier, so that enhancement in the speed of the writing operation can be achieved.
The internal control signal generator circuit COM-GE receives two external control signals, CS (chip select signal) and WE (write enable signal), and generates a plurality of control signals CS 1 , CS 2 , CS 3 , WECS, WECS, DOC, etc.
The sense amplifier circuit SASC receives the chip select signal CS and the internal complementary address signals a 7 -a 15 , and forms the foregoing sense amplifier selection signal and internal chip select signals CS, CS.
FIG. 2 is a block diagram which shows the address buffer ADB and row decoders R-DCR0, R-DCR1 and R-DCR2 in FIG. 2 in greater detail.
In FIG. 2, the circuits of those logic symbols whose output sides are marked black are quasi-CMOS circuits wherein an output transistor for charging and discharging an output signal line is made of a bipolar transistor, while transistors for logic processing such as inversion, non-inversion, NAND or NOR operations are made of CMOSFETs. The circuit of an ordinary logic symbol is a pure CMOS circuit.
As shown in FIG. 2, in the address buffer ADB, there are arranged non-inverting/inverting circuits G 0 -G 8 whose inputs receive the address signals A 0 -A 8 of TTL levels from outside and which serve to transmit the non-inverted outputs a 0 -a 8 and the inverted outputs a 0 -a 8 to complementary output signal lines.
Each of the non-inverting/inverting circuits G 0 =14 G 8 is constructed of a quasi-CMOS circuit as shown in FIG. 4.
In FIG. 4, Q 40 , Q 42 , Q 44 , Q 46 , Q 50 , Q 52 and Q 53 indicate N-channel MISFETs; Q 41 , Q 43 , Q 45 and Q 49 P-channel MISFETs; and Q 47 , Q 48 , Q 51 and Q 54 N-P-N bipolar transistors.
A resistor R 40 and the MISFET Q 40 constitute a gate protection circuit which serves to protect the gate insulator film of the MISFETs Q 41 , Q 42 from an external surge voltage applied to an input terminal.
Since the MISFETs Q 41 , Q 42 , Q 43 and Q 44 constitute a CMOS inverter of two-stage cascade connection, a signal inphase with the signal of a node N 1 is transmitted to a node N 3 .
Since also the MISFETs Q 45 and Q 46 constitute a CMOS inverter, a signal antiphase to the signal of the node N 3 is transmitted to a node N 4 .
The transistor Q 47 is an output transistor for charging the capacitive load C 41 of an output terminal OUT, while the transistor Q 48 is an output transistor for discharging the capacitive load C 41 .
Since also the MISFETs Q 49 and Q 50 constitute a CMOS inverter, a signal antiphase to the signal of the node N 3 is transmitted to a node N 5 .
The MISFET Q 52 is a source-follower MISFET which is turned "on" by the signal of the node N 3 so as to apply a base current to the transistor Q 54 for discharging the capacitive load C 42 of an output terminal OUT. The MISFET Q 53 operates, not only as the load of the source-follower MISFET Q 52 , but also as a switching MISFET for discharging charges stored in the base of the transistor Q 54 .
In order to prevent the transistor Q 48 from being driven in its saturation region, the source of the MISFET Q 45 is connected to the collector of the transistor Q 48 , not to a power source V CC . Likewise, in order to prevent the transistor Q 54 from being driven in its saturation region, the drain of the MISFET Q 52 is connected to the collector of the transistor Q 54 , not to the power source V CC . This point is also an important feature in improvements.
Accordingly, when a signal of high level is applied to the input terminal IN in the non-inverting/inverting circuit of FIG. 4, the node N 3 becomes the high level, and the nodes N 4 and N 5 become a low level, to supply a base current to the base of the transistor Q 47 through the transistor Q 43 , so that the transistor Q 47 is turned "on". When the output terminal OUT is at the high level, the MISFET Q 52 is turned "on", so that the base current is supplied to the transistor Q 54 through this MISFET Q 52 . At this time, the MISFETs Q 46 and Q 50 are "on" because the node N 3 is at the high level. In consequence, the transistors Q 45 and Q 54 turn "off" because charges stored in their bases are discharged through the MISFETs Q 46 and Q 50 . Therefore, the capacitive load C 41 is charged rapidly by the bipolar output transistor Q 47 of low output impedance, while the capacitive load C 42 is discharged rapidly by the bipolar output transistor Q 54 of low output impedance. When the charge of the capacitive load C 41 has ended, current stops flowing through the collector-emitter path of the transistor Q 47 . When the discharge of the capacitive load C 41 has ended, currents stop flowing through the drain-source path of the MISFET Q 52 and and the collector-emitter path of the bipolar transistor Q 54 .
When a signal of low level is applied to the input terminal IN of the non-inverting/inverting circuit in FIG. 4, the transistors Q 47 and Q 54 turn "off" and those Q 48 and Q 51 turn "on", so that the capacitive load C 41 is discharged fast, while the capacitive load C 42 is charged fast. At this time, the MISFET Q 53 turns "on" because the node N 5 becomes the high level. In consequence, charges stored in the base of the bipolar transistor Q 54 are fast discharged to a ground potential point through the MISFET Q 53 , so that the turn-off speed of the bipolar transistor Q 54 is enhanced. When the discharge of the capacitive load C 41 has ended, currents stop flowing through the drain-source path of the MISFET Q 45 and the collector-emitter path of the bipolar transistor Q 48 . When the charge of the capacitive load C 42 has ended, current stops flowing through the collector-emitter path of the bipolar transistor Q 51 .
If the charge and discharge of the capacitive loads C 41 and C 42 are not executed by the bipolar output transistors Q 47 , Q 48 , Q 51 and Q 54 but are instead executed by MISFETs, they will be executable only at low speed because the "on" resistance of the MISFET becomes a much larger value as compared with that of the bipolar transistor.
In contrast, in the address buffer of the embodiment in FIG. 2, the output transistors of the non-inverting/inverting circuits G 0 -G 8 for delivering the internal address signals a 0 , a 0 -a 8 , a 8 to the output signal lines thereof are made of the bipolar transistors as shown in FIG. 4, so that even when the output signal lines of the non-inverting/inverting circuits G 0 -G 8 are arranged over relatively long distances on the surface of the semiconductor chip, the non-inverting/inverting circuits G 0 -G 8 are permitted to operate at high speed.
The row decoder R-DCR0 in FIG. 2 operates as the predecoder of the address circuit. This row decoder R-DCR0 is constructed of 3-input NAND circuits G 16 -G 23 , G 24 -G 31 and G 40 -G 47 to which the internal address signals a 0 , a 0 -a 8 , a 8 obtained from the address buffer ADB are applied, and 2-input NOR circuits G 32 -G 39 to which the chip select signal CS and the output signals of the 3-input NAND circuits G 24 -G 31 are applied.
The output signal lines (that is, the output signal lines of the 3-input NAND circuits G 16 -G 23 and G 40 -G 47 and the output signal lines of the 2-input NOR circuits G 32 -G 39 ) of the row decoder R-DCR0 as the pre-decoder are arranged over long distances in the vertical direction within the row decoders R-DCR1 and R-DCR2, which are the decoder drivers of the address circuit, as illustrated in FIG. 2.
Each of the 3-input NAND circuits G 16 -G 23 , G 24 -G 31 and G 40 -G 47 within the row decoder R-DCR0 in FIG. 2 is constructed of a quasi-CMOS circuit as shown in FIG. 5.
The quasi-CMOS 3-input NAND circuit in FIG. 5 includes an input logic processing portion which is composed of P-channel MISFETs Q 55 -Q 57 and N-channel MISFETs Q 58 -Q 61 , and an output portion which is composed of N-P-N bipolar output transistors Q 62 , Q 63 . The MISFET Q 61 operates as a switching MISFET for discharging charges stored in the base of the bipolar transistor Q 63 .
When input signals of high level are applied to all of three input terminals IN 1 -IN 3 , the transistors Q 55 -Q 57 turn "off", the transistors Q 58 -Q 60 turn "on", a node N 7 becomes a low level, and the transistor Q 61 turns "off". Then, in the output portion, the transistor Q 62 turns "off", and when an output terminal OUT is at the high level, the transistor Q 63 is supplied with a base current through the transistors Q 58 -Q 60 and turns "on". Charges in the capacitive load C 43 of the output terminal OUT are rapidly discharged to a ground potential point through the collector-emitter path of the transistor Q 63 , while at the same time, a discharge current flow through a route which extends along the capacitive load C 43 , a diode Q 64 , the MISFETs Q 58 -Q 60 and the base-emitter junction of the bipolar transistor Q 63 . A voltage drop across both the ends of the diode Q 64 at this time controls the transistor Q 62 into its "off" state reliably.
When an input signal of low level is applied to at least one of the three input terminals IN 1 -IN 3 , the node N 7 becomes the high level, the transistor Q 62 turns "on", and the capacitive load C 43 is rapidly charged through the collector-emitter path of the transistor Q 62 . According to the high level of the node N 7 , the transistor Q 61 turns "on", and the charges stored in the base of the transistor Q 63 are rapidly discharged through the drain-source path of the transistor Q 61 , so that the turn-off speed of the transistor Q 63 can be enhanced.
In this manner, the output portion of the quasi-CMOS 3-input NAND circuit in FIG. 5 is constructed of the bipolar transistors Q 62 and Q 63 , and hence, the charge and discharge of the capacitive load C 43 are executed at high speed.
Incidentally, since the 3-input NAND circuits G 24 -G 31 within the row decoder R-DCR0 in FIG. 2 have their outputs connected to the inputs of the 2-input NOR circuits G 32 -G 39 which is only a relatively short distance connection, each of them may well be constructed of a pure CMOS circuit as shown in FIG. 6.
The pure CMOS 3-input NAND circuit in FIG. 6 is composed of P-channel MISFETs Q 64 -Q 66 and N-channel MISFETs Q 67 -Q 69 . Since the length of a signal line from an output terminal OUT is short as described above, the capacitance value of the stray capacitance C 44 of the output terminal OUT is small.
Accordingly, even when the charge and discharge of the small stray capacitance C 44 are executed by the MISFETs Q 64 -Q 66 and Q 67 -Q 69 having comparatively great "on" resistances, they can be executed at comparatively high speed.
Each of the 2-input NOR circuits G 32 -G 39 within the row decoder R-DCR0 in FIG. 2 is constructed of a quasi-CMOS circuit as shown in FIG. 7.
The quasi-CMOS 2-input NOR circuit in FIG. 7 includes an input logic processing portion which is composed of P-channel MISFETs Q 70 , Q 71 and N-channel MISFETs Q 72 -Q 74 , and an output portion which is composed of N-P-N bipolar output transistors Q 75 , Q 76 . The MISFET Q 74 operates as a switching MISFET which serves to discharge charges stored in the base of the bipolar transistor Q 76 .
When input signals of low level are applied to both of two input terminals IN 1 and IN 2 , the transistors Q 70 and Q 71 turn "on", the transistors Q 72 and Q 73 turn "off", and a node N 9 becomes a high level. Then, the transistor Q 75 turns "on", and the capacitive load C 45 of an output terminal OUT is rapidly charged through the collector-emitter path of the transistor Q 75 . The high level of the node N 9 turns "on" the transistor Q 74 , and the charges stored in the base of the transistor Q 76 are rapidly discharged through the drain-source path of the transistor Q 74 , so that the turn-off speed of the transistor Q 76 can be enhanced.
When an input signal of high level is applied to at least either of the two input terminals, for example, the input terminal IN 1 , the transistor Q 70 turns "off", the transistor Q 72 turns "on", and the node N 9 becomes the low level. Then, in the output portion, the transistor Q 75 turns "off", and when the output terminal OUT is at the high level, the transistor Q 76 is supplied with a base current through the transistors Q 72 , Q 77 and turns "on". Charges in the capacitive load C 45 of the output terminal OUT are rapidly discharged through the collector-emitter path of the transistor Q 76 , while at the same time, a discharge current flows through a route which extends along the capacitive load C 45 , a diode Q 77 , the drain-source path of the MISFET Q 72 and the base-emitter junction of the bipolar transistor Q 76 . Owing to a voltage drop across both the ends of the diode Q 77 at this time, the bipolar transistor Q 75 is reliably controlled into its "off" state.
The row decoders R-DCR1 and R-DCR2 in FIG. 2 operate as the decoder drivers of the address circuit. The row decoder R-DCR1 includes a 2-input NOR circuit G 48 which receives the output signals of the row decoder R-DCR0 2-input NAND circuits G 49 -G 56 which receive the output signal of the 2-input NOR circuit G 48 and the output signals of the row decoder R-DCR0, and inverters G 57 -G 64 which receive the output signals of the 2-input NAND circuits G 49 -G 56 .
The distances of the signal lines between the output of the 2-input NOR circuit G 48 and the inputs of the 2-input NAND circuits G 49 -G 56 are relatively long, and the stray capacitance values of these signal lines are large. Accordingly, the 2-input NOR circuit G 48 is constructed of the quasi-CMOS circuit as shown in FIG. 7.
Since the 2-input NAND circuits G 49 -G 56 within the row decoder R-DCR1 in FIG. 2 have their outputs connected to the inputs of the inverters G 57 -G 64 which is only a relatively short distance connection, each of them is constructed of a pure CMOS circuit as shown in FIG. 9.
The pure CMOS 2-input NAND circuit in FIG. 9 is composed of P-channel MISFETs Q 82 , Q 83 and N-channel MISFETs Q 84 , Q 85 . Since the length of the signal line from an output terminal OUT is short as described above, the capacitance value of the stray capacitance of the output terminal OUT is small.
Accordingly, even when the charge and discharge of the small stray capacitance C 47 are executed by the MISFETs Q 82 , Q 83 , Q 84 and Q 85 having comparatively great "on" resistances, they are executed at high speed.
The outputs of the inverters G 57 -G 64 within the row decoder R-DCR1 in FIG. 2 are connected to the word lines WL 11 -WL 18 of the memory array M-ARY1. Accordingly, the output signals lines (that is, the output signal lines of the inverters G 57 -G 64 ) of the row decoder R-DCR1 as the decoder driver are arranged to cover relatively long distances in the lateral direction inside the memory array M-ARY1 as the word lines WL 11 -WL 18 , so that the stray capacitances of the word lines WL 11 -WL 18 become quite large.
Thus, each of the inverters G 57 -G 64 within the row decoder R-DCR1 in FIG. 2 is constructed of a quasi-CMOS circuit as shown in FIG. 10.
The quasi-CMOS inverter in FIG. 10 is composed of a P-channel MISFET Q 86 , N-channel MISFETs Q 87 -Q 89 , and N-P-N bipolar output transistors Q 90 , Q 91 . The operation of this quasi-CMOS inverter is the same as the operation of the circuit Q 49 -Q 54 for obtaining the inverted output OUT of the non-inverting/inverting circuit in FIG. 4, and the detailed description shall therefore be omitted. The charge and discharge of a great stray capacitance C 48 are executed at high speed by the N-P-N bipolar output transistors Q 90 , Q 91 .
In FIG. 2, the row decoder D-DCR2 is constructed similarly to the R-DCR1 stated above.
FIG. 3 is a block diagram which shows the address buffer ADB, the column decoder C-DCR1, etc. in FIG. 1 in greater detail.
Also in FIG. 3, the circuits of those logic symbols whose output sides are marked black are quasi-CMOS circuits wherein an output transistor for charging and discharging the stray capacitance of an output signal line is made of a bipolar transistor and wherein logic processing such as inversion, non-inversion, NAND or NOR is executed by a CMOS circuit. The circuit of an ordinary logic symbol is a pure CMOS circuit.
As shown in FIG. 3, in the address buffer ADB, there are arranged non-inverting/inverting circuits G 7 -G 15 whose inputs receive the address signals A 7 -A 15 of TTL levels from outside and which serve to transmit the non-inverted output a 7 -a 15 and the inverted outputs a 7 -a 15 to their complementary output signal lines.
Each of the non-inverting/inverting circuits G 7 -G 15 is constructed of the quasi-CMOS circuit as shown in FIG. 4. Accordingly, the output transistors of each of the non-inverting/inverting circuits G 7 -G 15 are made of the bipolar transistors as illustrated in FIG. 4, so that even when the output signal lines of the non-inverting/inverting circuits G 7 -G 15 are arranged to extend relatively long distances on the surface of the semiconductor chip, the non-inverting/inverting circuits G 7 -G 15 are permitted to operate at high speed.
The column decoder C-DCR1 includes 2-input NAND circuits G 74 -G 77 , G 78 -G 81 and G 82 -G 85 to which the internal address signals a 7 -a 15 and a 7 -a 15 obtained from the address buffer ADB are applied, and 3-input NAND circuits G 86 -G 93 .
Further, as shown in FIG. 3, the output signal lines of the NAND circuits G 74 -G 93 are arranged with long distances and are connected to the input terminals of a large number of NOR circuits G 94 -G 95 inside the column decoder C-DCR1, so that the stray capacitances of the output signal lines of the NAND circuits G 74 -G 93 become large capacitance values.
Accordingly, each of the 3-input NAND circuits G 86 -G 93 is constructed of the quasi-CMOS 3-input NAND circuit as shown in FIG. 5, and each of the 2-input NAND circuits G 74 -G 85 is constructed of a quasi-CMOS 2-input NAND circuit which is obtained by omitting the input terminal IN 3 and the MISFETs Q 57 , Q 60 from FIG. 5.
On the other hand, in FIG. 3, the output signal lines of the 3-input NOR circuits G 94 , G 95 are connected to the inputs of inverters G 100 , G 101 with short distances, so that the stray capacitances of the output signal lines of the 3-input NOR circuits G 94 -G 95 have small capacitance values. Accordingly, each of the 3-input NOR circuits G 94 -G 95 is constructed of a pure CMOS 3-input NOR circuit.
Further, the output signal lines of the inverters G 100 , G 101 are connected to the input terminals of 2-input NOR circuits G 98 , G 99 with a relatively short distance connection so that the stray capacitances of the output signal lines of the inverters G 100 G 101 have small capacitance values. Accordingly, each of the inverters G 100 , G 101 is constructed of a well-known pure CMOS inverter.
Further, the output signal lines of the 2-input NOR circuits G 98 , G 99 are connected to the gate electrodes of the switching MISFETs Q 1001 , Q 1001 of the column switch C-SW 1 with comparatively short distance connections, so that the stray capacitances of the output signal lines of the NOR circuits G 98 , G 99 are small. Accordingly, each of these NOR circuits is constructed of a pure CMOS 2-input NOR circuit as shown in FIG. 8.
The pure CMOS 2-input NOR circuit in FIG. 8 is composed of P-channel MISFETs Q 78 , Q 79 and N-channel MISFETs Q 80 , Q 81 . Since the distance of the signal line from an output terminal is comparatively short, the stray capacitance C 46 of the output terminal OUT has a small capacitance value.
Accordingly, even when the charge and discharge of the small stray capacitance C 46 are executed by the MISFETs Q 78 , Q 79 Q 80 and Q 81 having comparatively great "on" resistances, they are executed at high speed.
Each of the aforementioned 3-input NOR circuits G 94 -G 95 is constructed of a pure CMOS 3-input circuit wherein a third input terminal IN 3 is added to the 2-input NOR circuit in FIG. 8, a third P-channel MISFET whose gate is connected to a third input terminal IN 3 is inserted in series with the MISFETs Q 78 and Q 79 , and a third N-channel MISFET whose gate is connected to the input terminal IN 3 is inserted in parallel with the MISFETs Q 80 , Q 81 .
In addition to the above, it can be seen that, in FIG. 3, the 1-bit memory cell M-CEL of the memory array M-ARY1 in FIG. 1 is shown in greater detail. Specifically, the memory cell M-CEL is shown as being composed of a flip-flop in which the inputs and outputs of a pair of inverters consisting of load resistances R 1 , R 2 and N-channel MISFETs Q 101 , Q 102 are cross-connected, and N-channel MISFETs Q 103 , Q 104 which serve as transmission gates.
The flip-flop is employed as a means for storing information. The transmission gates are controlled by the address signal which is applied to the word line WL 11 connected to the row decoder R-DCR1, and the information transmission between the complementary data line pair D 1001 , D 1001 and the flip-flop is controlled by the transmission gates.
FIG. 11 is a circuit diagram in which one example of the essential portions of the sense amplifier selector circuit SASC and one example of the internal control signal generator circuit COM-GE in FIG. 1 are shown more in detail.
Shown in the figure is the circuit of that part of the sense amplifier selector circuit SASC which receives the external chip select signal CS and which forms the control signals CS, CS to be supplied to the data output intermediate amplifier DOIA, the row decoder R-DCR0 and the column decoder C-DCR1.
The circuit of this portion to which the external chip select signal CS is applied is constructed of the same circuit as the non-inverting/inverting circuit in FIG. 4. Since the output signal CS of this circuit is obtained from bipolar output transistors R 1 , T 2 , T 3 and T 4 , the capacitance dependences of the charging and discharging speeds of the outputs CS, CS of the sense amplifier selector circuit SASC are low. Accordingly, even when the output CS of the sense amplifier selector circuit SASC is connected to the input terminals of the NOR gates G 32 -G 39 of the row decoder R-DCR0 in FIG. 2 and to the input terminals of the NOR gates G 94 -G 95 of the column decoder C-DCR1 in FIG. 3, this output CS becomes fast. Besides, even when the output CS of the sense amplifier selector circuit SASC is connected to the gate electrodes of a plurality of switching MISFETs within the data output intermediate amplifier DOIA, this output CS becomes fast.
Although no illustration is made in the figure, the sense amplifier selector circuit SASC includes a decoder circuit which receives the internal complementary address signals a 7 -a 15 and the aforementioned control signal CS and which forms a selection signal S1 to be supplied to the sense amplifier. Among the sense amplifiers SA1-SA16, the sense amplifier whose input terminals are electrically coupled to the complementary data line pair to be selected is selected by this decoder circuit, whereupon the sensing operation thereof is executed. The output portion of this decoder circuit is constructed of a quasi-CMOS circuit so as to lower the capacitance dependences of the charge and discharge of the output. Thus, the speed of the operation of selecting the sense amplifier can be enhanced. Even in a case where the above control signal is supplied to the decoder circuit, the control signal CS is fast because it is formed by the bipolar transistors as stated above.
Although, in the present embodiment, the decoder circuit is disposed in the sense amplifier selector circuit SASC in order to select the sense amplifiers, the selection signals formed by the column decoders C-DCR1 to C-DCR4 may well be utilized for the selection signals of the sense amplifiers. This measure can reduce the number of elements, and therefore permits enhancing the density of integration.
The internal control signal generator circuit COM-GE in FIG. 11 includes a circuit portion which is supplied with the external chip select signal CS, thereby to generate a plurality of internal delay chip select signals CS 2 , CS 1 , CS 1 and CS 3 . The greater part of this circuit portion is constructed of CMOS circuits. Since, however, the outputs CS 2 , CS 1 , CS 1 and CS 3 are respectively obtained from bipolar output transistors T 5 , T 6 ; T 9 , T 10 ; T 11 , T 12 ; and T 7 , T 8 , the capacitance dependences of the charge and discharge of these outputs are low.
The internal control signal generator circuit COM-GE in FIG. 11 is further provided with a circuit portion which is supplied with the external write enable signal WE and the internal delay chip select signals CS 1 , CS 2 , thereby to generate the write control signals WECS, WECS and a data output buffer control signal DOC. The greater part of this circuit portion is similarly constructed of CMOS circuits. Since, however, the signal WECS is obtained from bipolar output transistors T 14 , T 15 , the capacitance dependences of the charge and discharge of this output WECS are low. Accordingly, even when the output WECS is applied to the large number of input terminals of the NAND circuits (not shown) of the column decoder C-DCR1 in FIG. 3 or the gate electrodes of the switching MISFETs Q 1 , Q 16 -Q 16 , Q 16 in FIG. 1, this output WECS becomes fast.
FIG. 12 is a circuit diagram in which the sense amplifier SA1, the data output intermediate amplifier DOIA, the data output buffer DOB, etc, in FIG. 1 are shown more in detail.
FIG. 13 is a circuit diagram in which the data input buffer DIB, the data input intermediate amplifier DIIA1, etc. in FIG. 1 are shown more in detail.
FIG. 14 is a diagram of the signal waveforms of various parts in the read cycle and write cycle of the static RAM which is one embodiment shown in FIGS. 1 to 13.
First, the operation of the static RAM in the cycle of reading information will be described with reference to FIGS. 12 and 14.
It is assumed that, as illustrated in FIG. 14, simultaneously with the application of the address signals A 0 -A 15 , the chip select signal CS is changed to the low level, whereas the write enable signal WE is held at the high level as it is. As shown in FIG. 14, the internal delay chip select signals CS 1 , CS 2 , CS 3 , the write control signal WECS and the data output buffer control signal DOC are produced from the internal control signal generator circuit COM-GE at that time.
In a case where the supplied address signals A 0 -A 15 are, for example, those which appoint the word line WL 11 and the complementary data line pair D 1001 , D 1001 , the memory cell M-CEL which is disposed at the intersection point between the word line WL 11 and the complementary data line pair D 1001 , D 1001 is selected. The internal information of the selected memory cell M-CEL is transmitted to both the inputs of the sense amplifier SA1 through the complementary data line pair D 1001 , D 1001 and the switching MISFETs Q 1001 , Q 1001 . The sense amplifier SA1 is composed of a differential pair of emitter-coupled transistors T 21 , T 22 and a constant current source MISFET T 20 . When the selection signal S1 of high level is applied from the sense amplifier selector circuit SASC to the gate electrode of the constant current source MISFET T 20 , the sense amplifier SA1 executes the sensing operation.
When the internal chip select signal CS of high level is applied from the sense amplifier selector circuit SASC to the gate electrodes of constant current source MISFETs T 23 -T 26 of the data output intermediate amplifier DOIA, this data output intermediate amplifier executes the amplifying operation.
Accordingly, the output signal of the sense amplifier SA1 is transmitted to the output node N 11 of the data output intermediate amplifier DOIA through grounded-base transistors T 27 , T 28 , emitter-follower transistors T 29 , T 30 and output MISFETs T 35 -T 38 .
As illustrated in FIG. 12, the data output buffer DOB is supplied with the data output buffer control signal DOC from the internal control signal generator circuit COM-GE. In addition, as shown in FIG. 12, the data output buffer DOB is composed of a pure CMOS inverter of T 39 and T 40 , a quasi-CMOS 2-input NAND circuit of T 41 -T 48 , a quasi-CMOS 2-input NOR circuit of T 49 -T 56 , a P-channel switching MISFET T 57 , an N-channel switching MISFET T 58 , a P-channel output MISFET T 59 , and an N-channel output MISFET T 60 .
When the data output buffer control signal DOC is at the high level, the switching MISFETs T 57 , T 58 are turned "on", and the output MISFETs T 59 , T 60 are simultaneously turned "off", so that the output D out of the data output buffer DOB falls into a high impedance state (floating state).
In the cycle of reading information, the data output buffer control signal DOC becomes the low level to turn "off" the switching MISFETs T 57 , T 58 , and the gate electrodes of the output MISFETs T 59 , T 60 are controlled by the output of the quasi-CMOS 2-input NAND circuit and the output of the quasi-CMOS 2-input NOR circuit, the outputs being responsive to the signal level of the output node N 11 of the data output intermediate amplifier DOIA, whereby valid data is obtained from the output terminal D out .
In order to reduce the "on" resistances of the output MISFETs T 59 , T 60 , the channel widths W of these MISFETs are set at very large values. Then, the gate capacitances of these MISFETs T 59 , T 60 become very large. Since, however, the output portion of the quasi-CMOS 2-input NAND circuit is composed of the bipolar output transistors T 47 , T 48 and the output portion of the quasi-CMOS 2-input NOR circuit is composed of the bipolar output transistors T 55 , T 56 , the charge and discharge of the gate capacitances of the output MISFETs T 59 , T 60 are executed at high speed.
Referring now to FIGS. 13 and 14, the operation of the static RAM in the cycle of writing information will be described.
As illustrated in FIG. 14, simultaneously with the application of the address signals A 0 -A 15 , the chip select signal CS changes to the low level, whereupon the write enable signal WE changes to the low level. As shown in FIG. 14, the internal delay chip select signals CS 1 , CS 2 , CS 3 , the write control signal WECS and the data output buffer control signal DOC are produced from the internal control signal generator circuit COM-GE at that time.
As shown in FIG. 13, input data D in and the inverted internal chip select signal CS 1 are applied to the data input buffer DIB. In writing information, the signal CS 1 changes to the low level. Then, a P-channel switching MISFETT 61 of the data input buffer changes into the "on" state, and an N-channel switching MISFET T 62 into the "off" state. Thus, the input data D in is transmitted to an output node N 12 through pure CMOS inverters in multi-stage connection.
In writing information, the write control signal WECS changes to the low level. Then, within the data input intermediate amplifier DIIA1 in FIG. 13, P-channel MISFETs T 63 , T 65 turn "on", and N-channel MISFETs T 64 , T 66 turn "off", so that a signal inphase with the signal of the output node N 12 of the data input buffer DIB appears at a node N 13 , while a signal antiphase thereto appears at a node N 14 .
The signal of the node N 13 is transmitted to the common data line CDL 1 through a quasi-CMOS inverter composed of transistors T 67 -T 72 , while the signal of the node N 14 is transmitted to the common data line CDL 1 through a quasi-CMOS inverter composed of transistors T 73 -T 78 . Since the charge and discharge of the common data line pair CDL 1 , CDL 1 of great parasitic capacitances are executed by the bipolar output transistors T 71 , T 72 and T 77 , T 78 of these quasi-CMOS inverters, they are executed at high speed.
Thus, the complementary output signals of the data input intermediate amplifier DIIA1 are transmitted to the memory cell M-CEL through the common data line pair CDL 1 , CDL 1 , the switching MISFETs Q 1 , Q 1 , Q 1001 , Q 1001 , and the complementary data line pair D 1001 , D 1001 , whereby the writing of the information into the memory cell is executed.
As a result of the structure described in the foregoing description, the following advantages are achieved:
(1) Each of the non-inverting/inverting circuits G 0 -G 15 of an address buffer ADB is constructed of a quasi-CMOS circuit. Since, in the quasi-CMOS circuit, the greater part of a logic processing portion of non-inversion/inversion is constructed of CMOS circuits, a low power consumption is possible. Further, output transistors which execute the charge and discharge of non-inverted and inverted outputs are made of bipolar transistors, so that even when the stray capacitances of the output signal lines of the non-inverting/inverting circuits G 0 -G 15 become large, a high speed operation is obtained since the bipolar transistors can afford a lower output resistance with smaller element dimensions than a MISFET.
(2) Circuits whose output signal lines have large stray capacitances, such as the NAND circuits G 16 -G 23 , G 24 -G 31 , G 40 -G 47 , the NOR circuits G 32 -G 39 , G 48 -G 65 and the inverters G 57 -G 64 of row decoders R-DCR0, R-DCR1, R-DCR2 are constructed of quasi-CMOS circuits, so that these circuits will be low in the power consumption and high in operating speed.
Further, circuits whose output signal lines have small stray capacitances, such as NAND circuits G 49 -G 56 , are constructed of pure CMOS circuits, so that these circuits can be low in the power consumption.
(3) Circuits whose output signal lines have large stray capacitances, such as the NAND circuits G 74 -G 93 of column decoders C-DCR1 to C-DCR4, are constructed of quasi-CMOS circuits, so that these circuits will be low in the power consumption and high in operating speed.
Further, circuits whose output signal lines have small stray capacitances, such as NOR circuits G 94 -G 99 and inverters G 100 , G 101 , are constructed of pure CMOS circuits, so that these circuits will be low in the power consumption.
(4) Since a non-inverting/inverting circuit constituting a sense amplifier selector circuit SASC is constructed of a quasi-CMOS circuit, a low power consumption is achieved. Also, since outputs CS, CS are obtained from bipolar output transistors, these outputs CS, CS become fast even when their stray capacitances are large.
(5) Since an internal control signal generator circuit COM-GE is constructed of a quasi-CMOS circuit, a low power consumption is achieved, and since outputs CS 2 , CS 3 , CS 1 , CS 1 , WECS are obtained from bipolar output transistors, these outputs CS 2 , CS 3 , CS 1 , CS 1 , WECS become fast even when their stray capacitances are large.
(6) Since a data output buffer DOB is constructed of a quasi-CMOS circuit, a low power consumption is achieved.
Further, since the large gate capacitances of the output MISFETs of the data output buffer DOB are charged and discharged by bipolar output transistors, the charge and discharge of the gate capacitances are executed at high speed.
(7) Since a data input buffer DIB is constructed of a pure CMOS circuit, a low power consumption is achieved.
(8) Since a data input intermediate amplifier DIIA1 is constructed of a quasi-CMOS circuit, a low power consumption is achieved.
Further, since the charge and discharge of common data line pair CDL 1 , CDL 1 , which have large parasitic capacitances, are executed by bipolar output transistors, they are executed at high speed.
Owing to the synergistic effect of the above, the following characteristics could be obtained in the static SRAM described in the foregoing embodiment:
(a) The propagration delay time t pd from the input to the output of each of the non-inverting/inverting circuits G 0 -G 15 of the address buffer ADB was shortened to about 3.0 (nsec). The stand-by power consumption of all the non-inverting/inverting circuits G 0 -G 15 was reduced to about 33.7 (mW), and the operating power consumption to about 45.8 (mW).
(b) The propagation delay time t pd from the input to the output of each of the row decoders R-DCR0, R-DCR1, R-DCR2 and the column decoders C-DCR1 to C-DCR4 was reduced to about 4.8 (nsec). The stand-by power consumption of all the decoders was reduced to substantially zero, and the operating to about 153 (mW).
(c) The propagation delay time t pd of all of a memory cell M-CEL, a sense amplifier SA1 and a data output intermediate amplifier DOIA was reduced to about 5.0 (nsec). The stand-by power consumption of all memory cells M-CEL numbering 64 k (65536), all sense amplifiers SA1-SA16, and the data output intermediate amplifier DOIA was reduced to about 0.6 (mW), and the operating power consumption to about 160 (mW).
(d) The propagation delay time t pd from the input to the output of the data output buffer DOB was shortened to 2.8 (nsec). The stand-by power consumption was reduced to substantially zero, and the operating power consumption to 23.5 (mW).
(e) Owing to the above (a)-(d), the access time (read time) was shortened to about 15.6 (nsec). This value is substantially equal to the 15 (nsec) access time of presently known ECL type bipolar RAMs.
(f) Owing to the above (a)-(d), the stand-by power consumption of the static SRAM of the present embodiment was reduced to about 34.3 (mW), and the operating power consumption to about 382.3 (mW). These values represent relatively low power consumption characteristics intermediate between those of a prior-art bipolar RAM and a prior-art static MOSRAM (and actually closer to those of the prior-art static MOSRAM).
Although, in the above, the invention made by the inventors has been concretely described on the basis of a preferred embodiment, it is needless to say that the present invention is not restricted to the foregoing embodiment. On the contrary, it can be variously modified within a scope not departing from the subject matter thereof.
For example, in the memory cell M-CEL in FIG. 3, the load resistances R 1 , R 2 may well be replaced with P-channel MISFETs so as to construct the flip-flop out of CMOS inverters. Besides, the flip-flop may well be constructed of multi-emitter N-P-N transistors.
Further, by performing refresh, the memory cell M-CEL may well be constructed of an information latch circuit based on the storage of charges in a cell capacitance, not of the flip-flop circuit.
The signal level of the address signals A 0 -A 15 which are applied to the address buffer ADB may well be set to be ECL levels, rather than TTL levels, with the address buffer ADB executing a proper level conversion operation.
An input D in or output D out may well be constructed in the form of a plurality of bits (for example, 4 bits, 8 bits, . . . ), not 1 bit.
Also, of course, the number of the memory matrices is not restricted to four, but it may well be larger or smaller.
Further, although specific values have been given for various parameters on characteristics, it is to be understood that these are illustrative only, and do not serve to limit the present invention.
Finally, while , in the above, the invention made by the inventors has been chiefly described as to the case of application to the semiconductor memory, it is not restricted thereto.
For example, it is needless to say that, not only memory cells, address circuits for selecting a specified cell, signal circuits for handling the reading and writing of information, and the timing circuits for controlling the operations of reading and writing information can utilize the present invention. On the contrary, a variery of other circuits such as bipolar analog circuits, MOS analog circuits, P-channel MOS logic, N-channel MOS logic, CMOS logic, I 2 L circuits and ECL circuits can be arranged on the semiconductor chip as may be needed to incorporate the principles of the present invention. | In order to provide high speed and low power consumption, a semiconductor integrated circuit is constructed to utilize both CMOS elements and bipolar transistors. The bipolar transistors are used in the output portions to take advantage of their speed of operation to allow rapid charging and discharging of output lines. In the meantime, the principal operating portions of the circuit use CMOS elements of low power consumption. This arrangement is particularly advantageous in memory circuits. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an electrically operated fitting with a fitting body which has a valve means and an electrically operated drive means for the valve means.
2. Description of the Related Art
An electrically operated fitting of the initially mentioned type is already known from practice. In the known fitting, there are switches on the fitting body for actuating the drive means. Placing the switches on the fitting body makes it complex to build. In addition, the design of this known fitting leaves much to be desired. Finally, cleaning of the fitting in the area of the switches becomes difficult.
SUMMARY OF THE INVENTION
The object of the invention is, therefore, to make available an electrically operated fitting of the initially mentioned type which is simple and economical to build and which in addition has a pleasing, aesthetic form.
In an electrically operated fitting of the initially mentioned type, in accordance with the present invention, this object is essentially achieved by there being a housing for attachment and especially for sealing contact against the installation wall and by there being an actuation device of an electronic module on the housing for triggering the drive means. In the invention therefore the actuation means is moved from the fitting body to a separate housing which can be attached to the installation wall. The fitting body can, therefore, be made simply and economically in the conventional manner, while the housing with the actuation means is used for actuation and can be easily cleaned. The housing in the installed state is preferably sealed relative to the installation wall so that water cannot splash behind the housing and collect there.
Feasibly, the housing has not only the actuation means, but also the electronic module which is especially integrated into the housing, therefore is made in one piece with it. The housing with the actuation means and the electronic module can be easily installed as a unit, and in case of repair, can be removed easily. The inside and outside seal of the electronic module relative to the housing ensures that no malfunctions occur.
To impart a pleasing design to the housing, there is a cover to be placed on the housing to essentially conceal the housing. In the cover, there is an opening which unblocks the actuation means on the housing. The cover offers the advantage that, on the one hand, attachment points, connections or openings in the housing are not visible from the outside and that, on the other hand, when using one type of housing, via the cover different external designs can be chosen according to taste.
It is especially advantageous when the housing conceals the fitting body and/or the drive means, preferably completely. In this case, the entire fitting body with the drive means disappears behind the housing and can no longer be recognized from the outside. With a corresponding seal of the housing relative to the installation wall, it is guaranteed that water cannot splash behind the housing, which could adversely affect the operation of the electrically operated fitting.
Good attachment and a reliable seal of the housing on the installation wall can be achieved, for example, via screw connections, the housing being attached to the installation wall, the drive means and/or the fitting body and being drawn against the installation wall as screwing is being done and seals against the installation wall.
Other features, advantages and possible applications of this invention follow from the following description of embodiments using the drawings and the drawings themselves.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an overhead view of a fitting as claimed in the invention without the housing,
FIG. 2 shows a perspective view of the fitting as claimed in the invention with the housing removed,
FIG. 3 shows a perspective view of the fitting with the housing attached to the installation wall,
FIG. 4 shows a side view of the fitting as claimed in the invention with the housing swivelled out and
FIG. 5 shows a perspective view of a fitting as claimed in the invention in the assembled state.
DETAILED DESCRIPTION OF THE INVENTION
In the figures, one electrically operated fitting 1 is shown at a time, the fitting being a surface-type fitting for attachment to an installation wall 2 . The fitting could also be a flush-mounted fitting. The fitting 1 has a fitting body 3 which is provided with a supply housing 4 with a hot water supply 5 and a cold water supply 6 . Furthermore, the fitting 1 has a valve means 7 which is located within the fitting body 3 and which is not detailed. The valve means 7 is used for cutting off and mixing hot and cold water.
While the hot water supply 5 and the cold water supply 6 are located in a common supply plane, which in the installed state of the fitting, runs roughly at a right angle to the installation wall 2 , the valve means 7 is not located in the supply plane, but underneath this supply plane. It goes without saying that the valve means could, of course, also be located above the supply plane. This arrangement underneath one another yields a very low construction depth of the fitting 1 .
The valve means 7 , which is not explained in detail, in particular, has a thermostatic mixing valve unit (not shown) and a cutoff valve unit. The mixing valve unit is used to mix hot water and cold water to produce mixed water of stipulated temperature. The cutoff valve unit is used to open and close the fitting 1 and for adjusting the amount. Feasibly, the cutoff valve is located in the flow direction behind the mixing valve unit.
In addition to the fitting body 3 , the fitting 1 has another electrically operated drive means for the valve means 7 . In this embodiment, the drive means has two servomotors 8 , 9 which are each connected via a corresponding transmission to the mixing valve unit or the cutoff valve unit. The valve means 7 can be adjusted via the servomotors 8 , 9 for adjusting temperature and amount of the water.
It is significant here that a housing 10 is assigned to a fitting 1 and is designed for attachment and especially for sealing contact against the installation wall 2 . There is a control panel 11 of an electronic module 12 , outside on the housing 10 , for triggering the drive means. The control panel 11 has a keyboard 13 and a display 14 . The keyboard 13 and the display 14 are located on a board which is not shown and which is part of the electronic module 12 . The housing 10 is made in one piece with the control panel 11 and the electrical module 12 . The control panel 11 and also the electronic module 12 are both sealed on the front and back relative to the housing 10 such that water cannot reach the electronic and electrical components of the control panel 11 and/or the electronic module 12 .
Furthermore, there is a cover 15 to be placed on the housing 10 . The cover has an opening 16 which opens to the control panel 11 , but otherwise completely conceals the housing 10 . In this embodiment, the cover 15 is made in one piece in the manner of a lid. In any case, multi-piece versions are possible, for example, there being two cover parts which run vertically and two which run horizontally.
As follows from FIG. 4, the cover 15 can be detachably joined to the housing 10 . Between the housing 10 and the cover 15 , there is a pivot bearing 17 which is located on the top end of the housing 10 . Opposite the pivot bearing 17 , therefore on the bottom end of the housing 10 and the cover 15 , there is a catch connection 18 . The catch connection 18 has a spring-loaded catch pin 19 which is supported on the housing 10 and a catch opening which is not shown and which corresponds to the catch pin 19 .
The fitting 1 is battery-operated in this embodiment, and for this reason, has a battery compartment 20 . The battery compartment 20 has an elongated, especially tubular shape. The battery compartment can hold a row of batteries 21 for supply of the electronic module 12 and the servomotors 8 , 9 . The battery compartment 20 is made in one piece with the housing 10 and as shown in FIG. 3, is located above the supply housing 4 . To insert the batteries 21 , the tubular battery compartment 20 has an insertion opening 22 which can be sealed tight via a cover 23 with a handle section 24 . The cover 23 feasibly can be made of a elastomer material or has on the edge side, a corresponding seal so that a good sealing action results.
In this embodiment the housing 10 completely conceals the fitting body 3 and the valve means 7 . When the housing 10 is attached to the installation wall 2 and the cover 15 is seated, the fitting body 3 and the valve means 7 cannot be seen (compare FIG. 5 ). In addition to optical-aesthetic advantages, there are also practical advantages, since with corresponding sealing of the housing 10 relative to the installation wall 2 , water cannot penetrate into the area behind the housing 10 . In any case, it should be pointed out that it is not absolutely necessary to use the housing to conceal the fitting body or the valve means. The housing with the control panel, and optionally, the electronic module can also simply be assigned to the fitting body and attached elsewhere. It is also possible for the housing to only partially conceal the fitting body or the valve means, but for the cover to fully conceal these components.
The housing 10 is screwed to the fitting body 3 . For this purpose, as is shown in FIG. 2, there are screws 26 which can be screwed from the outside into the corresponding threaded holes 27 on the fitting body 3 via corresponding openings 25 in the housing 10 . The advantage of this type of attachment lies in that only the fitting body 3 requires attachment to the installation wall 2 via the corresponding screw connections with screws 28 . Therefore there need be no additional holes in the installation wall 2 for attaching the housing 10 . When the screws 26 are tightened to attach the housing 10 , the latter is then pressed against the installation wall 2 . To achieve a good sealing action, there should be a seal between the housing 10 , preferably in the area of the peripheral outside edge 29 and the installation wall 2 .
The electrical connection between the electronic module 12 and the battery compartment 20 with the servomotors 8 , 9 takes place via connecting cables 30 with the corresponding plug connectors (not shown). The electrical connection can be easily established by using plug connectors (not shown).
As was explained above, because the supply housing 4 and the valve means 7 are located underneath one another, the fitting 1 is especially flat. So that the flat construction can also be preserved when using the housing 10 , the electronic module 12 , in the installed state of the housing 10 , is located in front of the comparatively flat supply housing 4 , while the battery compartment 20 is located above the supply housing 4 running parallel to an edge of housing 10 and parallel to a transverse axis of the cover 15 . In this way, the free space between the fitting body 3 and the outside of the housing 10 is optimally used since, underneath the supply housing 4 of the fitting body 3 , there is the comparatively low valve means 7 with the servomotors 8 , 9 .
In the area of the outlet 31 of the fitting body 3 there is a manually actuated cutoff 32 . The manual cutoff 32 is used to actuate the fitting 1 if the motor-driven cutoff valve unit which is (not shown) should fail. To be able to operate the cutoff 32 easily, in the housing 10 , there is the corresponding opening 33 so that after removing the cover 15 , the cutoff 32 is accessible and can be actuated, for example, via a tool, without the need for disassembly of the housing 10 .
Mounting of the fitting 1 as claimed in the invention proceeds as follows. First, the fitting body 3 with the corresponding eccentric connections 34 which project out of the installation wall 2 in a surface-type fitting is screwed via screws 28 . Then, the connecting cables 30 are connected, on the one hand, to the housing 10 , and on the other hand, to the servomotors 8 , 9 (compare FIG. 2 ). Then, the housing 10 is screwed to the fitting body 3 via the screws 26 , and in doing so, the housing 10 is pressed against the installation wall 2 . In this state, the outlet 31 projects out of the corresponding opening 35 which is provided on the bottom of the housing 10 .
After the housing 10 has been attached, the batteries 21 can be inserted into the battery compartment 20 . Afterwards, the battery compartment 20 is sealed via the cover 23 . At this point, for example, a shower hose is attached to the outlet 31 , while between the outlet 31 and the opening 35 a seal may be provided. Finally, the cover 1 is first placed on the housing 10 and then swivelled on until the catch pin 19 engages. This results in the state shown in FIG. 5 .
The fitting 1 can then be actuated via the control panel 11 . The electronic module 12 is made such that the functions of opening, closing, quantity and temperature adjustment can be set via the keyboard 13 of the control panel 11 . Furthermore, it is also possible to input certain individually user-related programs. Adjustment of the desired mixed water amount and temperature or the desired program is done via corresponding pressure and/or proximity switches (not numbered) on the keyboard 13 . | An electrically operated fitting with a fitting body that has a valve arrangement and an electrically operated drive arrangement for operating the valve arrangement. In order to produce an electrically operated fitting which is of simple and economic construction while having an attractive aesthetic design, a housing is provided for mounting purposes, in particular, for sealing abutment with an installation wall. Disposed on the housing is an actuating arrangement for an electronic unit for controlling the drive arrangement. | 4 |
RELATED U.S. APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 10/134,664, filed Apr. 29, 2002.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] This invention relates to flexible intermediate bulk containers (FIBC) utilized for material transfer, particularly relates to net-based baffles for minimizing the space occupied by the FIBCs in the container while transferring thereof.
BACKGROUND OF THE INVENTION
[0005] Flexible intermediate bulk containers (FIBC) are extensively used for various bulk materials including industry-based granule, powder materials, food grade materials like sugar, flour, etc and even for quasi-fluid materials. Once the FIBCs are packed, they are accommodated into containers, trucks etc. for transferring thereof to another location.
[0006] Perhaps, one the most important aspects that is regarded as far as transferring the FIBCs are concerned is to achieve maximum amount of material transfer while minimizing the transfer sequence. This is the optimization problem leading the practitioners to minimize the space or volume occupied by the FIBCs in the container.
[0007] As a part of underlying physical effects, when bulk material, most of the time fine material, is introduced into an FIBC, it is tended (inclined) to move towards empty space or volume. It is interesting to note that, since edges of the FIBC are not available to promote such a tendency of bulk material movement, because of the physical restriction, the bulk material moves towards the lateral sides of the FIBC leading lateral bulged surfaces of the FIBC. Consequently, when the FIBCs are accommodated next to each other, simply some idle spaces are originated in the region of top and bottom corners of the FIBCs due to contact of the bulging surfaces of different FIBCs. However, these idle spaces occupy some considerable amount of volume, which is not filled by the material to be intended to transfer, in the container. The major requirement of a baffle is therefore to provide sufficient structural integrity so that bulging of the container sides is minimized and, at the same time, provide the maximum bulk material transmission through the baffle such that all of the spaces within the container are filled uniformly.
[0008] As a solution serving to overcome the above-mentioned problem in this technical field, numerous proposals have been made. Probably the most efficient proposals are focusing on sewing baffles to the edges of FIBCs diagonally. By doing so, movement tendency of bulk material towards the lateral sides of the FIBCs is decreased and potential bulging formation of the lateral sides is prevented.
[0009] The baffles accompanied with these solutions have hole-shaped formation and are sewed from the top region to the bottom region of the four edges of the FIBCs diagonally. The idea underlying the formation of these holes is to provide material penetration between the baffles and the edges in addition to essential part of the FIBCs.
[0010] It is acknowledged that the above-referenced solution put forwards sound advantages with respect to the deficiencies in the relevant technical field, however, another problems arise due to the physical nature of this solution such as interference of the baffle material to the bulk material carried due to spots of the holes. For instance, since the baffle is not a continuous part i.e. comprising holes, spots of the holes are likely to interfere with the bulk material. On the other hand, the present baffles are not able to be sewed through the edges i.e. from top to bottom, because of the idea that filling the space between the baffle and the edges of the FIBCs. In other words, in order to utilize the space between the sewed baffle and the edge, so providing bulk material transfer between the essential part and the space between the baffle and the edge, the baffle cannot be sewed through the edges i.e. through the top and bottom limits of the edges. As a consequence of this practice, the top and the bottom regions of the FIBCs become bulging driving indirectly volume loss in the container.
[0011] Another disadvantage accompanied with the state of the art is referred to structural deficiency in terms of functionality of the baffles. In fact for contributing the bulk material penetration through the holes of the baffles to the space between the baffle and the edge, a propeller is provided to promote uniform distribution of the bulk material in the FIBC. However, utilization of such a propeller induces many resources including labor, time.
[0012] It should also be noted that the normal method of fabricating baffles or similar structural maintenance means for a FIBC is to knit flaps to the side walls of the container and then to pass ropes through openings in the flaps. Thus, at least two separate process steps are required to anchor the baffles with the container. It would be advantageous if the baffles could be fixed to the container in a single step process.
BRIEF SUMMARY OF THE INVENTION
[0013] An object of the present invention is to provide substantially rectangular prism formation of the FIBCs so that the volume occupied thereof is minimized in the container. This is achieved by utilizing diagonally situated baffles which provide sufficient structural integrity to substantially eliminate bulging of the container sides and, at the same time, permit maximum bulk material transmission across the plane of the baffle to promote even filling of the central space and side spaces defined by the baffles and the container walls.
[0014] That object is achieved in part by forming the baffles of the present invention of filaments which are knitted. For purposes of this patent, the term “filament” is used to mean a single thread or a thin flexible thread-like object that has a substantially diametric geometry when viewed in cross-section. It is meant to exclude fabric strips or other long, narrow pieces of material.
[0015] Forming the baffles of the present invention of knitted filaments provides the necessary strength and promotes maximum material flow between the spaces which they define by reducing the surface area of the baffle to a minimum. The filaments, that is, a single thread or a thin flexible thread-like material, form the baffles which are sewed diagonally to the edges of the FIBCs through the top and bottom limits of the edges. Once the baffles are sewed to the edges, two volumetric regions or spaces are defined in the FIBC; one of these volumetric regions is referred to essential part in which most of the bulk material is held and the other volumetric region is referred as subsidiary part formed between the baffle and the edge of the FIBC.
[0016] The baffles of the present invention are formed of vertically extending elements and horizontally extending elements connected to the vertically extending elements. It is important that the elements which form the overall baffle be knitted together in the same production step, as explained in greater detail below. This means that the vertically extending elements are not produced with an independent production step and then the horizontally extending elements are attached to them in some manner, or visa versa. Further, the vertically extending elements are preferably composed of one or more threads and not a woven material.
[0017] The development introduced by the present invention is based upon net-based baffles promoting bulk material transition between the essential and subsidiary volumetric parts and simultaneously providing reducing movement tendency of bulk material towards the lateral surfaces of the FIBCs.
[0018] The net-based baffle in the scope of the present invention may be in a conventional fishing net or alternatively various net patterns. One significant technical feature proposed by this embodiment is that the plurality of passages and filaments providing structural integrity of the net. A second significant feature proposed by applicant's embodiment is that the baffles can be affixed to the container walls utilizing a single step method.
[0019] The requirement preventing a bulging formation of the FIBCs is that having a hexagon or octagon geometrical formation when viewed the FIBC from the top rather than having quadrangle once the baffles are sewed to the FIBCs, whereby bulk material movement tendency towards the lateral surfaces is reduced. In addition to this effect, the net-based baffles contribute to bulk material transition between the essential and subsidiary volumetric parts by means of the net structure.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] Further objects and advantages of the present invention will become apparent upon reading the following description taken in conjunction with the appended drawings wherein:
[0021] FIG. 1 illustrates a perspective view of a FIBC with net-based baffles sewed to the edges thereof;
[0022] FIG. 2 illustrates a top view of a FIBC with net-based baffles;
[0023] FIG. 3 a illustrates two column net-based baffles;
[0024] FIG. 3 b illustrates four column net-based baffles;
[0025] FIG. 4 a illustrates net-based baffle with triangle structure;
[0026] FIG. 4 b illustrates net-based baffle with diagonal structure;
[0027] FIG. 4 c illustrates net-based baffle with hexagonal structure;
[0028] FIG. 5 illustrates net-based baffle with quadrangle structure;
[0029] FIGS. 6 a and 6 b are respectively a front view of a typical baffle of the present invention and an enlarged section thereof showing the knitted structure thereof in detail;
[0030] FIGS. 7 a , 7 b and 7 c respectively illustrate the three types of threads that form the knitted structure of FIG. 6 b ; and
[0031] FIG. 8 is a schematic representation of the machine used to form the knitted structure of FIG. 6 b.
DETAILED DESCRIPTION OF THE INVENTION
[0032] In FIG. 1 , net-based baffles and the location thereof in the FIBC are illustrated. Conventionally, a FIBC, flexible intermediate bulk container ( 1 ) is a means for transferring materials and having a rectangular prism geometry carried by holders ( 2 ). The baffles ( 3 ) are sewed to the connection edges ( 9 ) of the FIBC ( 1 ) diagonally so as to obtain a relatively rounded geometry in the essential volume ( 11 ) of the FIBC, i.e. independent of sharp geometry due to edges. The lateral surfaces ( 7 ) are attached to each other by connection edges ( 9 ) so that the FIBC ( 1 ) is formed.
[0033] Net-based baffles ( 3 ) comprise preferably two vertically extending strips ( 8 ) and horizontally extending elements provided between the vertically extending strips, and net filaments ( 4 ). One of the vertically extending strips ( 8 ) is sewed to the lateral surface ( 7 ) and the inner one is embodied for connecting the net filaments ( 4 ) thereto. As an alternative structure, the vertically extending strips ( 8 ) of different baffles ( 3 ) may be sewed as one on the top of the other to the lateral surfaces ( 7 ).
[0034] As it is proposed, the net-based baffles ( 3 ) comprise plurality of net passages ( 10 ) providing bulk material transition between the essential volume ( 11 ) and the subsidiary volume ( 12 ). Furthermore, the net-based baffles ( 3 ) are sewed through the top limit ( 5 ) and bottom limit ( 6 ) of the FIBC ( 1 ). Whereby, potential bulging formation in the top and bottom regions is prevented.
[0035] In FIG. 2 , top view of a FIBC with sewed net-based baffles ( 3 ) is illustrated. As seen in the figure, the essential volume ( 11 ) gains a rounded and compact geometry. In other words, once the net-based baffles ( 3 ) are sewed to the edges, the essential volume ( 11 ) become more rounded shape by hexagon or octagon geometries with respect to an essential part lacking baffles.
[0036] A preferred embodiment of the present invention is based upon an octagonal geometry when viewed from the top, however it may be possible to have a FIBC structure based upon a hexagonal geometry when baffles ( 3 ) are connected on a lateral surface ( 7 ).
[0037] In FIG. 3 a , an alternative baffle ( 3 ) with double column is illustrated. As seen in the figure, there is an intermediate connection ( 13 ) between the columns. Similarly, various embodiments can be derived as seen in FIG. 3 b showing an baffle ( 3 ) with quartet columns. The number of columns and intermediate connections ( 13 ) can be enhanced optionally. For baffles ( 3 ) having plurality of columns, the net filaments ( 4 ) are fixed from one end to the vertically extending strips ( 8 ) and connected to intermediate connections ( 13 ) from the other ends.
[0038] In FIG. 4 a , an alternative structure having triangle shaped net passages ( 10 ) is illustrated. As mentioned above, similarly, the number of columns can be increased optionally.
[0039] Similarly, in FIG. 4 b , an alternative structure having diagonal shaped net passages ( 10 ) is illustrated.
[0040] FIG. 4 c illustrates net passages ( 10 ) having hexagonal shaped formation.
[0041] In FIG. 5 , quadrangle shaped net passages ( 10 ) are shown.
[0042] In the preferred embodiment, the space occupied by the horizontally extending threads of the baffle is about 3-20% in each one meter of baffle length. In other words, the area occupied by the threads connecting the vertically extending elements is about 3-20% of the rectangular area defined by the baffle, for each one meter of baffle length. In the most preferred embodiment, the space occupied by the horizontally extending threads is approximately 7% of each one meter of baffle length. In conventional baffles, this ratio is in the order of 70%, ten times that of the present invention. Furthermore, the thickness of those threads is preferably 0.5-5 nm.
[0043] The method of forming the net-based baffles of the present invention is illustrated in FIGS. 6 through 8 .
[0044] The baffle is a knitted structure formed of three types of elements, each element being a filament, that are knitted together is a single operation by the machine illustrated in FIG. 8 . FIG. 6 b illustrates in detail the structure that results from knitting the three types of elements, designated as first type, second type and third type, respectively. The first type element and the second type element are knitted to extend vertically. The third type element is knitted to extend horizontally to connect the first type and the second type.
[0045] FIGS. 7 a , 7 b and 7 c show the elements separately for clarity. FIG. 7 a shows the horizontally extending third type element. FIG. 7 b shows the first type vertically extending element and FIG. 7 c shows the second type vertically extending element.
[0046] In the preferred embodiment, the first type of element is formed of thread that is 1900 dtex (thread “gram” weight in each 10,000 “meter”), the second type element is formed of thread of 1100 dtex and the third type element is formed of thread of 3000 dtex. However, different relative and absolute thread gram weights may be utilized.
[0047] The vertically extending elements are formed by the side knots (first type) and by the side knot connecting threads (second type). As seen in the FIG. 8 , the thread bobbins of the knitting machine are first arranged to a creel and threaded in to the machine. Knitting is performed by knitting heads being swinging and the knitting heads having needles at the tips thereof. Driving motion of the knitting heads is controlled by a computer programmed to form the baffle.
[0048] Three knitting heads are required to form the baffle of the present invention. Since there are six heads mounted on the machine, two baffles can be formed simultaneously.
[0049] Once the threads in the creel are threaded into the machine, the operator drives the machine to start the knitting process and the machine continuously knits the vertically extending elements and the connecting horizontal extending element. The knitted baffle is drawn by drums arranged to the machine. Although it is theoretically possible to continue knitting to form a baffle of any length, as a practical matter, the baffle is cut to a predetermined length size based upon the height of the container by the cutting and winding machine.
[0050] This baffle production method utilizes only threads as an input and only a single knitting machine is required to form the baffle. No manual intervention or additional devices are required. The baffle produced in this manner are directly sewn to the flexible containers.
[0051] One of the most important advantages of producing the baffles in a single (structurally integrated) process is to prevent baffle material involvement into bulk material which is most of the time food-based or chemical-based fine material or granule material. By way of contrast, baffles produced by discrete processes have a potential risk to be torn and contaminate the bulk material due to bulk material charging or discharging load.
[0052] Although only a limited number of preferred embodiments of the present invention have been disclosed for purposes of illustration, it is obvious that many variations and modifications could be made thereto. It is intended to cover all of those variations and modifications which fall within the scope of the present invention, as set forth in the following claims: | A flexible intermediate bulk container (FIBC) for transferring various type of materials, including industry-based granule materials, fine materials like sugar, flour, comprising baffles sewed to edge region of the FIBCs for preventing bulging formation on lateral surfaces thereof so defining an essential volume and subsidiary volume in the FIBC and said baffles having holes for promoting material transfer between the essential volume and subsidiary volume the development comprising said baffle ( 3 ) formed as a net structure having plurality of filaments ( 4 ), plurality of net passages ( 10 ) between these filaments ( 4 ) and connection elements ( 8 ) the filaments ( 4 ) are attached thereon. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing a head suspension for a disk drive incorporated in an information processing unit such as a personal computer.
2. Description of the Related Art
A hard disk drive (HDD) used for an information processing unit has magnetic or magneto-optical disks to write and read data and a carriage. The carriage is turned around a spindle by a positioning motor. The carriage is disclosed in, for example, U.S. Pat. No. 4,167,765. This carriage has arms, a head suspension attached to each arm, and a head attached to the suspension and having a slider.
When each disk in the HDD is rotated at high speed, the slider slightly floats above the disk and air bearings are formed between the disk and the slider.
FIG. 1 shows atypical suspension 101 of an HDD. The suspension 101 has a load beam 103 . The load beam 103 is fixed to a base plate 105 by, for example, laser welding. The base plate 105 is fitted to a carriage arm of the HDD.
The load beam 103 consists of a rigid part 107 of L 1 in length and a resilient part 109 of L 2 in length. A flexure 111 is fixed to the rigid part 107 by, for example, laser welding. An end of the flexure 111 has a tongue 113 to which a slider 115 is attached. The tongue 113 is pushed by a dimple 117 , which is formed at an end of the rigid part 107 . Although the dimple 117 is depicted with a solid line in FIG. 1, it is actually on the back of the tongue 113 .
The rigid part 107 is provided with positioning holes 121 and 125 , and the flexure 111 is provided with positioning holes 123 and 127 .
The holes 121 , 123 , 125 , and 127 are set on positioning pins of a jig to align the rigid part 107 and flexure 111 with each other, and the rigid part 107 and flexure 111 are fixed to each other by, for example, laser welding. The positioning and fixing of the flexure 111 to the rigid part 107 determine the vibration characteristics of the suspension 101 .
Disks of recent HDDs are designed to densely record data and revolve at high speed. It is required, therefore, to provide a suspension of improved vibration characteristics to carry out precision positioning of a head on an HDD disk surface, To meet the requirement, the suspension 101 must be compact. Namely, the distance A between the dimple 117 and a fitting center of the base plate 105 must be short. The distance A, however, must sufficiently be long to secure a proper distance between the holes 121 and 125 for correct positioning of the flexure 111 with respect to the rigid part 107 .
If the distance A is excessively shortened to improve vibration characteristics, the holes 121 and 125 will be too close to each other, thereby deteriorating positioning accuracy.
To solve this problem, FIGS. 2A to 2 C show a head suspension 101 A for a disk drive according to a prior art. This prior art forms a positioning hole 125 on the side of a base plate 105 . Even if the distance A (FIG. 1) between a dimple 117 and a fitting center of the base plate 105 is short, a sufficient distance is secured between positioning holes 121 ( 123 ) and 125 ( 127 ) for correct positioning of a flexure 111 to a rigid part 107 .
Formation of the suspension 101 A will be explained FIG. 2A is a plan view showing parts of the suspension 101 A before assembly, and FIG. 2B is a plan view showing the parts after assembly. In FIG. 2A, the flexure 111 is provided with the positioning holes 123 and 127 . The base plate 105 is fitted to a reinforcing plate 129 . The reinforcing plate 129 is solidly joined with the rigid part 107 of a load beam 103 through a bridge 131 , to form a semi-finished suspension 133 . The rigid part 107 is provided with the positioning bole 121 , and the reinforcing plate 129 with the positioning hole 125 .
A resilient material 135 is used to form a resilient part 109 of the load beam 103 . The resilient material 135 is placed over the rigid part 107 and reinforcing plate 129 and is fixed thereto by, for example, laser welding. Thereafter, the base plate 105 is fitted to the reinforcing plate 129 and is fixed thereto by, for example, laser welding
The semi-finished suspension 133 with the resilient material 135 and base plate 105 is set on a jig by passing pins of the jig through the holes 121 and 125 , and the flexure 111 is laid thereon by passing the jig pins passed through the holes 121 and 125 through the holes 123 and 127 respectively. This precisely positions the flexure 111 with respect to the rigid part 107 as shown in FIG. 2 B.
The distance between the holes 121 ( 123 ) and 125 ( 127 ) is appropriate for precision positioning between the rigid part 107 and the flexure 111 . Under this state, the flexure 111 is fixed to the rigid part 107 by, for example, laser welding.
Thereafter, the bridge 131 is cut off by, for example, a press, to complete the suspension 101 A of FIG. 2 C.
One problem of this prior art is to leave the peripheries of the holes 125 and 127 on the base plate 105 , to cause a horizontal imbalance on the base plate 105 . This imbalance deteriorates the vibration characteristics of the suspension 101 A.
SUMMARY OF TE INVENTION
An object of the present invention is to provide a method of manufacturing a bead suspension or a semi-finished suspension that is compact, secures a sufficient distance between positioning holes, and involves no base-plate imbalance.
In order to accomplish the object, a first aspect of the present invention provides a method of manufacturing a head suspension for a disk drive. The head suspension has a base plate to be supported by a carriage, a load beam including a rigid part resiliently supported by the base plate, to apply load onto a slider, and a flexure positioned and fitted to the load beam and having a read-write head. The method includes a first step of forming a semi-finished suspension having the base plate, the rigid part solidly joined with the base plate through a bridge, and a protrusion protruding from one of the base plate and rigid part and having a positioning bole to be aligned with a positioning hole formed through part of the flexure, a second step of fixing a resilient material to the base plate and rigid part of the semi-finished suspension so that the base plate may resiliently support the rigid part through the resilient material, a third step of aligning the positioning hole of the flexure with the positioning hole of the protrusion and fixing the flexure to the rigid part, and a fourth step of cutting off the positioning-hole-formed part of the flexure, the bridge, and the protrusion including the positioning hole.
The first aspect may form the positioning hole of the protrusion in the vicinity of the base plate, to secure a proper distance between the positioning hole and a positioning hole formed through the rigid part. This results in precisely positioning the flexure with respect to the rigid part and correctly fixing the flexure thereto. The first aspect cuts off the bridge, the protrusion having the positioning hole, and the positioning-hole-formed part of the flexure. As a result, the suspension manufactured from the semi-finished suspension has no positioning holes including their peripheries, to cause no horizontal imbalance and improve the vibration characteristics of the suspension. In addition, the suspension of the first aspect is compact to further improve the vibration characteristics thereof.
A second aspect of the present invention makes the bridge serve as the protrusion.
The second aspect forms the positioning hole to be aligned with the positioning hole of the flexure on the bridge that solidly joins the rigid part to the base plate. The second aspect provides the same effect as the first aspect.
A third aspect of the present invention forms, in the first step, the positioning hole through one of the protrusion and bridge in the vicinity of the base plate.
The third aspect secures a proper distance between the positioning hole on one of the protrusion and bridge and a positioning hole on the load beam, to correctly position the flexure with respect to the load beam.
A fourth aspect of the present invention provides, in the first step, one of the protrusion and bridge with a corner in the vicinity of the base plate and forms the positioning hole at the corner.
The fourth aspect secures a long distance between the positioning hole on one of the protrusion and bridge and a positioning hole on the load beam, to make the suspension compact and correctly position the flexure with respect to the load beam.
A fifth aspect of the present invention provides a semi-finished suspension used for manufacturing a head suspension for a disk drive. The head suspension has a base plate to be supported by a carriage, a load beam including a rigid part resiliently supported by the base plate, to apply load onto a slider, and a flexure positioned and fitted to the load beam and having a read-write head. The semi-finished suspension has the base plate, the rigid part solidly joined with the base plate through a bridge, and a protrusion protruding from one of the base plate and rigid part and having a positioning hole to be aligned with a positioning hole formed through part of the flexure.
The fifth aspect cuts off the bridge and protrusion so that the base plate may have no positioning holes and their peripheries. As a result, a suspension manufactured from the semi-finished suspension of the fifth aspect involves no horizontal imbalance and shows improved vibration characteristics.
A sixth aspect of the present invention makes the bridge serve as the protrusion.
The sixth aspect forms the positioning hole to be aligned with the positioning hole of the flexure on the bridge that solidly joins the rigid part to the base plate. The bridge is cut off in the last stage so that the base plate may have no positioning holes including the peripheries of the holes. As a result, a suspension manufactured from the semi-finished suspension of the sixth aspect involves no horizontal imbalance and shows improved vibration characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing a head suspension for a disk drive according to a prior art;
FIG. 2A is a plan view showing parts of a head suspension for a disk drive before assembly according to a prior art;
FIG. 2B is a plan view showing an assembled state of the parts of FIG. 2A;
FIG. 2C is a plan view showing a finished suspension formed from the assembled parts of FIG. 2B;
FIG. 3 is a sectional view partly showing an HDD having head suspensions according to an embodiment of the present invention;
FIG. 4A is a plan view showing parts of the suspension of the first embodiment before assembly;
FIG. 4B is a plan view showing an assembled state of the parts of FIG. 4A; and
FIG. 4C is a plan view showing a finished suspension formed from the assembled parts of FIG. 4 B.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is a sectional view partly showing an HDD having head suspensions according to an embodiment of the present invention. The HDD 1 has a carriage 5 that is turned around a spindle 3 by a positioning motor 7 such as a voice coil motor.
The carriage 5 has a plurality of (four in FIG. 3) arms 9 each having the suspension 11 of the present invention. The suspension 11 has a write-read head 13 .
The carriage 5 is driven around the spindle 3 by the motor 7 , to move the head 13 onto a required track on a disk 15 .
The head 13 has a slider 17 to face a track on the disk 15 , and the slider 17 has a transducer (not shown). When the disk 15 is revolved at high speed, air enters between the slider 17 and the disk 15 to form air bearings between them to slightly float the slider 17 above the disk 15 .
The present invention is characterized by removing positioning holes from the suspension 11 before completing the manufacturing of the suspension 11 . First, the structure of the suspension 11 will be explained, and then, a method of manufacturing the same will be explained.
FIGS. 4A to 4 C show the details of the suspension 11 , in which FIG. 4A is a plan view showing parts of the suspension 11 before assembly, FIG. 4B is a plan view showing an assembled state of the parts, and FIG. 4C is a plan view showing a finished state of the suspension 11 .
The suspension 11 shown in FIG. 4C is compact and has a base plate 19 and a load beam 21 . The base plate 19 is fitted to the carriage arm 9 (FIG. 3 ). Referring also to FIG. 4A, the base plate 19 is made of, for example, stainless steel and has a flange 23 and a boss 25 . The flange 23 is circular in plan view. The boss 25 protrudes in the thickness direction of the flange 23 . The boss 25 is fitted to a hole 9 a of the arm 9 .
The load beam 21 applies load onto the slider 17 and consists of a rigid part 27 and a resilient part 29 . The resilient part 29 is made of a resilient material 31 that is independent of the rigid part 27 . The rigid part 27 is made of, for example, stainless steel. The rigid part 27 may be made of an alloy of light metal (lighter than Fe) such as aluminum (Al) and titanium (Ti), or synthetic resin to reduce weight and increase rigidity. Alternatively, the rigid part 27 may be made of layers of two or more materials including light metal such as aluminum and titanium, alloys of light metal, and other metals such as stainless steel.
The resilient material 31 has a rectangular shape and extends over the base plate 19 (reinforcing plate 37 ) and rigid part 27 . The resilient material 31 is, for example, a thin stainless steel plate and has an accurate spring constant lower than that of the rigid part 27 . The resilient material 31 has a hole 33 fitted to the boss 25 of the base plate 19 . The diameter of the hole 33 is equal to or slightly larger than the diameter of the boss 25 .
When the resilient material 31 is laid on the reinforcing plate 37 , a side 31 a of the resilient material 31 protrudes from the reinforcing plate 37 . A rectangular opening 35 is formed through the side 31 a by etching, precision press, etc. The opening 35 partially reduces the bending rigidity (spring constant) of the resilient material 31 and forms the resilient part 29 between the sides 31 a and 31 b . The side 31 a overlaps a base end 27 b of the rigid part 27 and is fixed thereto by laser welding, adhesives, etc. At this time, a front edge of the opening 35 is substantially on a rear edge 27 c of the rigid part 27 .
The hole 33 of the resilient material 31 is fitted to the boss 25 of the base plate 19 , so that the side 31 b overlaps the flange 23 . Namely, the side 31 b is sandwiched between the flange 23 and the reinforcing plate 37 . The reinforcing plate 37 and the base plate 19 commonly serve as a base plate to be attached to the carriage arm 9 (FIG. 3 ).
The reinforcing plate 37 is made of, for example, stainless steel and has a positioning hole 39 . The hole 39 is made by, for example, etching to be precisely fitted to the boss 25 for correct horizontal positioning.
When the boss 25 is inserted into the hole 39 , the side 31 b of the resilient material 31 is sandwiched between the flange 23 and the reinforcing plate 37 and is fixed there by, for example, laser welding. In this state, a front edge of the reinforcing plate 37 is substantially on a rear edge of the opening 35 of the resilient material 31 .
A flexure 41 is attached to the rigid part 27 . The flexure 41 has a metal base 43 made of, for example, a thin resilient stainless steel rolled plate. An insulating layer is formed on the metal base 43 , and a conductor 45 is formed on the insulating layer. An end of the conductor 45 is connected to a terminal of the head 13 and the other end thereof is connected to an external terminal (not shown). The flexure 41 is fixed to the rigid part 27 by laser welding, adhesives, etc. The flexure 41 has a tongue 47 to which the slider 17 of the head 13 is attached.
The suspension 11 of the structure mentioned above is fixed to the carriage arm 9 of FIG. 3 . More precisely, the boss 25 is inserted into the hole 9 a of the arm 9 and is plastically widened by a jig, to fix the suspension 11 to the arm 9 .
The flange 23 of the base plate 19 is opposite to the arm 9 with the resilient material 31 interposing between them, to secure a gap between the load beam 21 and the disk 15 . Namely, the suspension 11 is compact, and at the same time, is capable of securing a sufficient inclination angle for the load beam 21 with respect to the disk 15 .
Since the rigid part 27 and resilient part 29 (i.e., the resilient material 31 ) that form the load beam 21 are discrete, they can be made of different materials with different thicknesses. As a result, requirements such as high rigidity for the rigid part 27 and a low spring constant for the resilient material 31 can simultaneously be met.
The resilient material 31 may be made of precision rolled material to provide a stable low spring constant. The resilient material 31 is sandwiched between the flange 23 and the reinforcing plate 37 both being thicker than the resilient material 31 . As a result, the resilient material 31 is stably supported by the base plate 19 , and the rigid part 27 is stably and resiliently supported by the base plate 19 through the resilient material 31 .
A method of manufacturing the suspension 11 of the present invention will be explained.
The flexure 41 is provide with positioning holes 49 and 51 in advance. The hole 49 is formed close to the tongue 47 , and the hole 51 is formed through a protrusion 53 protruding from the metal base 43 . The protrusion 53 has a hooked shape so that is may stably be set on a bridge 57 of a semi-finished suspension 55 .
A first step of the method forms the semi-finished suspension 55 by, for example, etching. The semi-finished suspension 55 consists of the rigid part 27 and reinforcing plate 37 that are connected to each other through the bridge 57 . The bridge 57 has a rectangular shape in plan view and has a corner 57 a on the reinforcing plate 37 side and a corner 57 b on the rigid part 27 side. The reinforcing plate 37 is connected to a scrap area (not shown) through legs 59 . Namely, many rigid parts 27 and reinforcing plates 37 are chained in rows and connected to the scrap area.
A front end 27 a of the rigid part 27 has a positioning hole 61 , and the corner 57 a of the bridge 57 has a positioning hole 63 . In this embodiment, the bridge 57 serves as a protrusion provided for the reinforcing plate 37 (serving as part of the base plate) or the rigid part 27 . The front end 27 a has a dimple 60 .
The scrap area connected to many rigid parts 27 and reinforcing plates 37 has positioning boles, which are set on positioning pins of a jig. At this time, other positioning pins of the jig are inserted into the positioning holes 61 and 63 of each semi-finished suspension 55 .
A second step of the method sets chained resilient materials 31 over the chained semi-finished suspensions 55 by passing the positioning pins of the jig through positioning holes of a scrap area of the chained resilient materials 31 .
Each base plate 19 is set on each resilient material 31 , and the boss 25 is passed through the hole 33 and fitted to the hole 39 . In FIGS. 4A to 4 C, the base plate 19 , resilient material 31 , and reinforcing plate 37 are laid in this order from the bottom, and are fixed together by, for example, laser welding.
A third step of the method passes the jig pins through the positioning holes 49 and 51 of the flexure 41 and the positioning holes 61 and 63 of the semi-finished suspension 55 , to align the positioning holes with each other. As a result, the flexure 41 is correctly positioned with respect to the rigid part 27 . At this time, the positioning hole 63 on the corner 57 a of the bridge 57 is sufficiently distanced from the positioning hole 61 on the rigid part 27 even if the distance between the dimple 60 and a fitting center of the base plate 19 is short to improve the vibration characteristics of the suspension 11 . Due to the sufficient distance between the holes 61 and 63 , the flexure 41 is correctly positioned and fitted to the rigid part 27 .
Due to the correct positioning of the flexure 41 , the finished suspension 11 shows improved vibration characteristics. The correctly positioned flexure 41 and rigid part 27 are fixed to each other by, for example, laser welding in the third step as shown in FIG. 4 B.
A fourth step of the method cuts off the bridge 57 from the rigid part 27 and reinforcing plate 37 , as well as the legs 59 , to complete the suspension 11 of FIG. 4 C.
The completed suspension 11 has no positioning hole 63 and the periphery thereof around the base plate 19 , nor the positioning hole 51 and protrusion 53 around the flexure 41 . As a result, the base plate 19 is horizontally balanced to greatly improve the vibration characteristics of the suspension 11 .
In this way, the present invention secures a proper distance between the holes 61 and 63 for correct positioning of the flexure 41 to the rigid part 27 , horizontally balances the base plate 19 , and miniaturizes the suspension 11 as a whole. These effects synergistically work to improve the total vibration characteristics of the suspension 11 .
The embodiment forms the positioning hole 63 on the corner 57 a of the bridge 57 . The hole 63 may be shifted from the corner. The bridge 57 may have any configuration if it can solidly connect the rigid part 27 and reinforcing plate 37 to each other. The bridge 57 is not always required to have the corners 57 a and 57 b . For example, the bridge 57 may have only the corner 57 a and may be curved toward the rigid part 27 without a corner on the rigid part 27 side.
The embodiment forms the positioning hole 63 on the bridge 57 . Instead, the hole 63 may be formed through a protrusion, which is separately formed from the bridge 57 , to protrude from the reinforcing plate 37 or rigid part 27 . In this case, the protrusion may have a corner in the vicinity of the reinforcing plate 37 , and the positioning hole 63 may be formed through the corner to secure the distance between the hole 63 and the hole 61 on the rigid part 27 . This protrusion is prepared with the semi-finished suspension 55 .
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A method manufactures a head suspension for a disk drive. The method includes a first step of forming a semi-finished suspension ( 55 ) having a base plate ( 37 ), a rigid part ( 27 ) solidly joined with the base plate through a bridge ( 57 ), and a positioning hole ( 63 ) formed through the bridge. This positioning hole is aligned with a positioning hole ( 51 ) formed through part of a flexure ( 41 ). A second step of the method fixes a resilient material ( 31 ) to the base plate and rigid part of the semi-finished suspension so that the base plate may resiliently support the rigid part through the resilient material. A third step of the method aligns the positioning hole of the flexure with the positioning hole of the bridge and fixes the flexure to the rigid part. A fourth step of the method cuts off the positioning-hole-formed part of the flexure and the bridge including the positioning hole. This suspension is compact and the load beam and flexure thereof are correctly positioned to secure balance. | 8 |
BACKGROUND
The invention relates to a control device, in particular for a heating and/or air conditioning system, for controlling air flows in motor vehicles.
DE 44 42 000 A1 relates to a control device of this type for a heating and/or air conditioning system which is designed as a louver cassette and is inserted into air ducts of a heating and/or air conditioning system for a motor vehicle. The control device regulates the amount and also the direction of the air flow passing through it. The control device is formed by a frame in which a multiplicity of pivotable slats which form a flap-type louver is arranged. Pivoting of the slats in a range of from 0 to 90° enables the passage cross section for the air flow to be completely closed, completely opened or partially opened up, the direction of the air flow also being influenced by the position of the slats. This louver cassette has a multiplicity of parts, caused by the slat design and the activating means associated therewith. In the case of narrow air gaps, whistling noises and possibly also rattling noises may occur. In addition, a louver cassette of this type has a relatively high air resistance, i.e. decrease of pressure.
DE 35 14 385 A1 has already disclosed replacing conventional flaps for controlling the air flows in a heating and/or air conditioning system by a “roller-type louver”. The latter comprises a roller band which is partially provided with cutouts and closes or partially or completely opens up the passage openings of air flow ducts. The roller band is wound up and unwound in a manner guided via individual rollers, and is brought by means of a servomotor via a drive roller into a closing, opening or intermediate position.
SUMMARY
EP 0 705 725 A1 has disclosed a development of a roller-type louver of this type. In this, a film-like roller band which has, distributed over its length, a multiplicity of different cutouts for the passage of an air flow is guided past the outlet openings of the air conditioning system housing and therefore controls the outlet cross section for the air. In a further application, a roller band of this type is arranged directly in front of the heating element and controls the amount of air passing through the heating element and the bypass flow flowing around the heating element. This type of roller-type louver is adapted in each case to the specific installation conditions and configurations of a specific heating and/or air conditioning system.
It is the object of the present invention to improve a control device, in particular for a heating and/or an air conditioning system, to the effect that the control device has a minimal construction space, can be used universally and can be installed in a simple manner into the heating and/or air conditioning system, with it being possible for the control device to be assembled in a simple manner.
The main concept of the invention involves designing the frame of a control device for controlling air flows in motor vehicles in such a manner that the roller-type louver can be inserted into the frame and removed therefrom in a simple manner. This is achieved by two hollow bodies which are open along the longitudinal side and accommodate the drive shaft or the return shaft for the roller-type louver, the hollow bodies each having a pivotable cover for opening the particular hollow body. The roller band of the roller-type louver is preferably designed in such a manner that it accommodates both shafts in the manner of an endless band. In this case, there can be a fixed connection between the roller band and shaft, in particular on the drive shaft, for example by the roller band being attached fixedly to the shaft in some regions, in particular being clamped in a manner such that it runs in the longitudinal direction of the shaft.
In one advantageous embodiment, the pivotable cover is connected to the hollow body by means of a hinge, the hinge being designed, for example, as a film hinge.
In one particularly advantageous embodiment of the invention, at least parts of the hollow body are integrally formed on the housing, the at least one passage opening being arranged between the two hollow bodies.
In a further embodiment, the roller-type louver is connected fixedly to the drive shaft, the drive shaft comprising, for example, at least two parts between which the roller-type louver is clamped, the two parts being connected to each other by means of clipping or locking.
In one particularly advantageous embodiment of the invention, the roller-type louver is designed as an endless roller band with clearances for opening up the at least one passage opening.
In a preferred embodiment, the roller band is guided in two layers past the at least one passage opening, the clearances being distributed on the roller band in such a manner that, when a passage opening is closed, each layer of the roller band covers approximately half of the passage opening, the passage opening being opened by the two layers of the roller band moving in opposite directions and opening up the passage opening from the center outward. The two-layered structure advantageously avoids a fluttering of the band and, as a result, reduces the production of noise. The described manner of opening up the passage opening means that only half of the actuating path is required for opening or closing the passage opening.
For better guidance and actuation of the roller band, the at least one passage opening is divided by lattice bars into a plurality of apertures.
The drive shaft is driven by means of a servomotor, which is, for example, flanged directly onto the frame, or via a Bowden cable or a flexible shaft.
In another embodiment, the servomotor is integrated into the drive shaft, which is designed as a hollow shaft.
In a particularly advantageous embodiment of the invention, one frame is used to change two air flows, the frame comprising for this purpose two passage openings, the passage cross sections of which are changed, in which, in a first starting position, a first passage opening is completely opened and a second passage opening is completely closed, in which, in a second starting position, the first passage opening is completely closed and the second passage opening is completely opened, and in which any desired passage cross sections for the particular passage opening can be set between the first and the second starting position. In this case, the passage openings may also be arranged at predeterminable angles, for example of up to 90°, with respect to one another, as a function of the installation situation.
In one embodiment having two passage openings of the same size, the sum of the passage cross sections of the two passage openings always produces the maximum possible passage cross section of a passage opening.
For better guidance of the roller band in the case of a plurality of passage openings, the frame includes at least one supporting device between two passage openings, the supporting device being connected, preferably releasably, for example to the two side parts and, as a result, preventing a leakage from one passage opening to the other passage opening.
A particularly simple installation on the basis of a small number of individual parts and a simple insertion of the drive shaft and/or return shaft arises if the hollow body is designed in such a manner that at least one bearing point is provided in side walls of the hollow body, in which the drive shaft or the return shaft is mounted, in particular a respective half bearing being formed in side walls, both in the lower part and in the upper part, in each hollow body. However, it is also possible to form the bearing point completely in the upper part or in the lower part.
The previously described control device is preferably used in heating or air conditioning systems for motor vehicles.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are illustrated in the drawings and are described in more detail below.
In the drawings:
FIGS. 1 a - d show a control device having a roller-type louver for changing one passage cross section;
FIGS. 2 a - d show a control device having a roller-type louver for changing two passage cross sections;
FIG. 3 shows a sectional illustration of the control device according to FIG. 1 b;
FIG. 4 shows a sectional illustration of the control device according to FIG. 2 b;
FIGS. 5 a - b show a sectional illustration of the region of the return shaft according to FIGS. 1 b and 2 b;
FIGS. 6 a - b show a sectional illustration of the drive shaft with the roller band;
FIGS. 7 a - c show various roller bands in a schematic illustration;
FIG. 8 shows an enlarged detail of the drive shaft with the roller band;
FIGS. 9 a - c show a sectional illustration of the control device according to FIG. 1 ;
FIGS. 10 a - c show a control device according to FIG. 2 ;
FIG. 11 shows an alternative embodiment of the control device for controlling two air flows;
FIGS. 12 a - d show an alternative embodiment of the control device;
FIGS. 13 a - c show a further embodiment; and
FIGS. 14 a - c show sections through various roller bands.
DETAILED DESCRIPTION
FIG. 1 shows a control device 1 , having a frame which comprises a housing 2 and two side parts 3 . The housing encloses a passage opening 4 which is divided by lattice bars 4 . 1 into a plurality of apertures 4 . 2 . These lattice bars 4 . 1 , which are arranged in parallel, serve to strengthen the housing 2 and also to orient the air flow passing through it. In the exemplary embodiment illustrated, on the longitudinal sides, a respective lower part 8 . 1 of a hollow body 8 , which is open along one longitudinal side, is integrally formed on the housing 2 , the hollow body in the exemplary embodiment illustrated being designed as a hollow cylinder, and the two hollow bodies 8 either accommodating a drive shaft 6 or a return shaft 7 . An upper part 8 . 3 is connected pivotably to the lower part 8 . 1 via a movable element 8 . 2 . When the hollow body is opened, the roller-band subassembly, comprising a roller band 5 , the drive shaft 6 and the return shaft 7 , can be inserted in a simple manner from above into the housing 2 . The upper part 8 . 3 is then pivoted onto the lower part and the housing 2 is closed on its transverse sides by the side parts 3 .
The control means for changing the passage cross section of the passage opening comprise the endless roller band 5 , the drive shaft 6 and the return shaft 7 . The drive shaft 6 and the return shaft 7 are mounted rotatably in corresponding bearing points of the side parts 8 by means of end-side pins or hollow pins (not illustrated specifically). The roller band 5 is guided over the circumference of the drive shaft 6 and the return shaft 7 . The roller band 5 has cutouts 5 . 1 which correspond in their cross sections to that of the apertures 4 . 2 in the housing 2 . The cutouts 5 . 1 are divided by individual, narrow strips 5 . 2 , so that in the roller band 5 the required tensile stress is maintained over the entire width and an airtight contact of the roller band 5 against the two shafts 6 and 7 is ensured.
FIGS. 1 a to 1 d show the individual parts of the control device 1 and the sequence during the assembly of the control device 1 . FIG. 1 a shows the housing 2 with the upper part 8 . 3 of the hollow body 8 pivoted open.
FIG. 1 b shows the housing with the roller-band subassembly inserted in it, the drive shaft and the return shaft being inserted into the two lower parts 8 . 1 of the hollow bodies.
FIG. 1 c shows the housing with the hollow body closed, i.e. the upper part 8 . 3 has been pivoted onto the lower part via the moveable element, which is designed in the exemplary embodiment illustrated as a film hinge, as a result of which the hollow body 8 is closed apart from a longitudinal slot 8 . 5 through which the roller band 5 is guided.
FIG. 1 d shows the control device with the housing 2 closed by the side parts 3 .
The control device described is inserted into a heating and/or air conditioning system (not illustrated here) for a motor vehicle, the control device being adapted with regard to its external dimensions to the particular air flow duct, so that the entire air flow cross section can be controlled by the cassette. In the exemplary embodiment illustrated, the passage cross section of a passage opening 4 can be controlled by five apertures 4 . 2 .
FIG. 2 shows a control device 1 having a frame which comprises a housing 2 and two side parts 3 . In contrast to the exemplary embodiment in FIG. 1 , the housing here encloses two passage openings 4 which are divided by lattice bars 4 . 1 into a plurality of apertures 4 . 2 . As is apparent from FIG. 2 , the control device, analogously to the control device according to FIG. 1 , likewise comprises a housing 2 with hollow bodies 8 integrally formed on it for accommodating the drive shaft 6 and the return shaft 7 , and two side parts 3 and a roller band 5 . In addition, a supporting device 9 for the additional guidance of the roller band 5 is arranged between the two passage openings 4 . In the exemplary embodiment illustrated, the passage cross section can be controlled by two passage openings 4 . The illustration shows a first starting position in which the left passage opening is completely opened and the right passage opening is completely closed.
FIGS. 2 a to 2 d show the individual parts of the control device 1 for controlling two passage openings and the sequence during the assembly of the control device 1 . FIG. 2 a shows the housing 2 with the upper part 8 . 3 of the hollow body 8 pivoted open.
FIG. 2 b shows the housing with the roller-band subassembly (roller band 5 , drive shaft 6 , return shaft 7 ) inserted and with a supporting device 9 placed between the passage openings 4 , the drive shaft 6 and the return shaft 7 being inserted into the two lower parts 8 . 1 of the hollow bodies 8 .
FIG. 2 c shows the housing 2 with the hollow body 8 closed, i.e. the upper part 8 . 3 has been pivoted onto the lower part 8 . 1 via the moveable element 8 . 2 , which is designed in the exemplary embodiment illustrated as a film hinge, as a result of which the hollow body 8 is closed except for a longitudinal slot 8 . 5 through which the roller band 5 is guided.
FIG. 2 d shows the control device with the housing 2 closed by the side parts 3 , the supporting device 9 likewise being connected, for example clipped, to the side parts.
FIG. 3 shows a sectional illustration of the control device 1 according to FIG. 1 b without a roller band 5 , in order to illustrate the pivoting movement 8 . 6 of the upper part 8 . 3 of the hollow body 8 about the pivot axis 8 . 7 which runs approximately centrally through the moveable element 8 . 2 . As is apparent from FIG. 3 , a lug 8 . 4 is integrally formed on the open end of the upper part 8 . 3 , the lug facilitating the guidance of the roller band 5 when the hollow body 8 is closed.
FIG. 4 shows a sectional illustration of the control device 1 according to FIG. 2 b with the roller-band subassembly (roller band 5 , drive shaft 6 , return shaft 7 ) inserted and the supporting device 9 placed on it.
FIG. 5 shows a section through the region of the return shaft 7 according to FIGS. 1 b and 2 b . FIG. 5 a shows the region with the roller-band subassembly inserted into the housing 2 and with the hollow body opened. FIG. 5 b shows the region of the roller-band subassembly inserted into the housing 2 and with the hollow body 8 closed. As is apparent from FIG. 5 , the roller band 5 is guided in two layers 5 . 3 , 5 . 4 over the passage openings 4 . The lug 8 . 4 which is integrally formed on the upper part 8 . 3 of the hollow body facilitates the guidance of the roller band 5 through the longitudinal opening 8 . 5 of the hollow body 8 .
FIG. 6 shows a schematic illustration of the connection of the roller band 5 to the drive shaft 6 . As is apparent from FIG. 6 a , the drive shaft 6 comprises a lower part 6 . 1 and an upper part 6 . 2 , it being possible for the upper part 6 . 2 to be connected to the lower part 6 . 1 by means of a clip connection 6 . 3 . For the connection to the drive shaft 6 , at its ends the roller band has, for example, holes 5 . 5 through which it is fixed on the lower part 6 . 1 of the drive shaft 6 . When the upper part 6 . 2 is clipped to the lower part 6 . 1 , the roller band is then clamped and, as a result, is connected fixedly to the drive shaft. For clarification, FIG. 6 b shows an illustration of the lower part 6 . 1 of the drive shaft 6 with the corresponding clips 6 . 3 for the clip connection to the upper part 6 . 2 .
FIG. 7 shows various roller bands 5 in a schematic illustration. Thus, FIG. 7 a shows a roller band 5 for controlling two passage openings. The roller band 5 has cutouts 5 . 1 which correspond with regard to their cross sections to that of the apertures 4 . 2 in the housing 2 . The cutouts 5 . 1 are divided by individual, narrow strips 5 . 2 . The edges 5 . 6 of the cutouts are preferably beveled in order to ensure that the two roller-band layers easily run over one another. At the two ends, the roller band 5 has holes 5 . 5 for the fastening to the drive shaft 6 . FIGS. 7 b and 7 c show roller bands for controlling a passage opening having a different number of apertures 4 . 2 .
FIG. 8 shows an enlarged detail of the roller band 5 in the region of the drive shaft 6 corresponding to the illustration in FIGS. 1 d and 2 d , the same reference numbers being used to a very great extent. As is apparent from FIG. 8 , the roller band 5 is connected at its two ends fixedly to the drive shaft 6 . The design of the roller band 5 as an endless band causes the formation of an upper layer 5 . 4 and a lower layer 5 . 3 which move in relation to each other when the drive shaft 6 is rotated. A suitable arrangement of cutouts therefore makes it possible to open the passage openings from the center of the passage opening outward or to close them from the outside to the center. The drive shaft 6 is situated in the hollow body 8 of the housing 2 , the hollow body 8 having a slot 8 . 5 in the direction of the center of the housing. The upper part 8 . 3 of the hollow body 8 merges into a resiliently designed lug or tongue 8 . 4 having a radius R, above which the roller band 5 is introduced into the hollow body 8 and is led out of it again. The endless roller band 5 has an upper layer 5 . 4 and a lower layer 5 . 3 which move in an opposed manner with respect to each other. The roller band 5 loops around approx. ¾ of the circumference of the drive shaft 6 and is tensioned by the resilient tongue 8 . 4 . The tongue 8 . 4 therefore replaces a tensioning roller.
As further possibilities for the connection of the roller band 5 to the drive shaft 6 , the roller band 5 may also be fastened at its two ends to the drive shaft 6 by the roller-band ends being welded to the drive shaft 6 in the longitudinal direction thereof. In the case of the described fastenings to the drive shaft, the adjustment path for the roller band is dependent on the circumference of the drive shaft or on the angle of wrap.
A further possibility for connecting the roller band 5 to the drive shaft 6 is explained in more detail with respect to FIGS. 13 a to 13 c . In this case, the drive shaft 6 is of two-part design with a lower part 6 . 1 and an upper part 6 . 2 , the two parts 6 . 1 and 6 . 2 being connected integrally to each other via two connecting webs 6 . 4 , which basically have a type of hinge function. The connecting webs 6 . 4 have an essentially rectangular cross section of 0.5 mm×2 mm and are formed by spray ducts, with a buckling point being provided approximately centrally. In this case, the connecting webs 6 . 4 are designed in such a manner that they are arranged in the interior of the drive shaft 6 when the two parts 6 . 1 and 6 . 2 are folded together.
The roller band 5 is in principle positioned in the abovementioned manner by means of fixing pins 6 . 5 and is clamped between the two parts 6 . 1 and 6 . 2 by means of snap hooks 6 . 6 (clip connection). The connection of the two parts 6 . 1 and 6 . 2 takes place, as is apparent from FIG. 13 b and FIG. 13 c (see the corresponding arrows in the figures) by means of a combined pivoting/longitudinal movement, with essentially a longitudinal movement taking place for the clipping (cf. FIG. 13 c ). With regard to the design of the roller band 5 , reference is made to FIGS. 7 a to 7 c , in particular with regard to the holes 5 . 5 on the two edges thereof.
The roller band 5 may be a single-layer film (monofilm), as illustrated in FIG. 14 a . A film of aluminum or a multilayered film having a layer of aluminum, as illustrated in FIGS. 14 b and 14 c , is particularly suitable in particular with regard to a low heat conductivity. The layer of aluminum may be, for example, vapor-deposited or bonded on, if appropriate also only in one region of the roller band. The roller band 5 consists, in particular, of readily glidable, abrasion-resistant material which is thermally stable in a region of from −40° C. to 100° C. Furthermore, the roller band should be low in noise and water-repellent. The layer thicknesses may differ here.
FIGS. 9 a to 9 c show a sectional illustration of the control device according to FIG. 1 during the transition from a first starting position (passage opening closed) into a second starting position (passage opening opened) via an intermediate position (passage opening partially opened). As is apparent from FIG. 9 , because of the use of the two layers 5 . 3 , 5 . 4 of the roller band 5 , the roller band 5 requires a shorter adjustment path in order to bring the passage opening from the closed starting position into the opened starting position, since each layer has to be moved only by an adjustment path which corresponds approximately to half of the width A of the passage opening 4 . For this purpose, the drive shaft has to be rotated further through an angle of approximately 270°. It emerges from this that, in the case of the exemplary embodiment illustrated, ¾ of the circumference of the drive shaft or of the return shaft corresponds approximately to half of the width A of the passage opening.
FIGS. 10 a to 10 c show the control device according to FIG. 2 during the transition from a first starting position (left passage opening opened, right passage opening closed) into a second starting position (left passage opening closed, right passage opening opened) via an intermediate position (both passage openings partially opened). As is apparent from FIG. 10 , opened apertures are closed from the outside to the center and closed apertures are opened from the center to the outside.
FIG. 11 shows an embodiment of the control device for controlling two air flows which run at a predetermined angle with respect to one another. For this purpose, the two passage openings are arranged at the predetermined angle with respect to each other. The angle is achieved by a corresponding design of the region between the two passage openings.
FIGS. 12 a to 12 d show an embodiment, in which bearing points 8 . 6 which are integrated into the hollow bodies 8 are provided for the drive shaft 6 and return shaft 7 . In this case, regions which are cut out or recessed in the form of a semicircle are provided in the lower part 8 . 1 and upper part 8 . 3 on side walls 8 . 7 and form the bearing points 8 . 6 . In this case, the side walls 8 . 7 can be of widened design in this region, so that the material is subjected to a lower loading. A side part 3 which is placed on, as illustrated, for example, in FIG. 1 a , can be omitted, since the two side walls 8 . 7 , which are formed on the housing 2 with lower parts and upper parts 8 . 1 and 8 . 3 , take on the function thereof.
The two shafts are inserted together with the roller band 5 into the lower bearing points 8 . 6 in the direction of the two arrows of FIG. 12 d . The upper parts 8 . 3 are then pivoted shut, so that the upper bearings 8 . 6 come into contact with the shafts. The locking of lower and upper part takes place by means of a clip connection 8 . 8 which is provided on the side walls 8 . 7 , as can be gathered in particular from FIG. 12 d . For the positioning and improved transmission of force in the radial direction of the side walls 8 . 7 with respect to the bearing points 8 . 6 , a lug 8 . 9 is provided on the side walls 8 . 7 of the upper part 8 . 3 and, during the closing process, passes into a corresponding receptacle 8 . 10 which is formed on the side walls 8 . 7 of the lower part 8 . 1 . | The invention relates to a control device ( 1 ) for controlling airflows in motor vehicles, comprised of a frame having at least one passage opening ( 4 ) and at least one controlling means, which is provided in the form of a roller louver ( 5 ) and which serves to modify the passage cross-section for the air flowing through the passage opening ( 4 ). The frame comprises a housing ( 2 ) with at least two hollow bodies ( 8 ) that are open along the longitudinal sides. These hollow bodies ( 8 ) accommodate the drive shaft ( 6 ) or the return shaft ( 7 ) for the roller louver ( 5 ), and each have a pivotal cover ( 8.3 ) for opening the respective hollow body ( 8 ). The control device ( 1 ) can be mounted inside airflow ducts of a heating and/or air-conditioning system for motor vehicles. | 8 |
The present invention claims priority to co-pending Great Britain Patent Application No. 0304060.7 filed 21 Feb. 2003, incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The invention relates to a method for authenticating a user of a mobile station for accessing to private data or services, and more particularly to a text-message based authentication method.
BACKGROUND OF THE INVENTION
A user of a mobile station, such as a mobile phone, a feature phone, or an evolved laptop computer or a personal digital assistant (pda) having communication capabilities (compliant with GSM, CDMA, 2.5G, 3G, UMTS . . . etc networks), or a smart-device (i.e. a combination of pda and mobile phone) enables its user to have access to remote source of data or services.
As an example described in WO 02/076122, it is possible for a user of a mobile station to have access to a telephone directory service. Typically, the user place a call to a specific number and request a phone number. The requested phone number is received via a short message services (SMS) and can be further stored in the mobile station for later use. In such a system, the user selects the requested information by either accessing a web interface or indirectly through an operator.
This access to the information is quite complicated and do not offer sufficient security, in particular when an access to private data or services is required.
OBJECT AND SUMMARY OF THE INVENTION
Therefore it is an object of the present invention to provide a method and system that overcomes the at least one shortcoming of the prior art system.
The present invention provides a method for accessing private data or services over a public network including the step of authenticating a user of a mobile station (MS) for accessing to private data/services (D, S), comprising the steps of:
composing a text-based request message on the mobile station using a standard public text messaging protocol, said message including a request for private data (SP), and sending said request message to a private server (MG, PS) offering the access to said private data/services (D, S), via the telephone network (N), checking the authenticity of the user based on the request message received by the server (MG, PS), if the user authenticity is confirmed, composing a text based response message using a standard public text messaging protocol, the response message including the requested private data/services (D, S) of the private server, and sending back to the user said text based response message, via the telephone network (N),
wherein the request message additionally includes a user unique identifier (AP), and is received by the private server with an appended user mobile station number,
wherein the authenticity checking performed by the private server comprises the steps of:
checking whether the user unique identifier (AP) is stored in a private directory database (DB), and checking whether the appended user mobile station number matches with the user mobile station number allocated to the user unique identifier stored in the private directory database (DB);
and wherein the interaction between the private server and the mobile station is limited to the exchange of the text-based request message and the text based response and further interaction between the private server and the mobile station require the sending of a new request message.
From the mobile station user perspective, the security is improved because the user knows to which private server number he has to send the request message, and he knows his own user unique identifier to be included in the request message. Security can be additionally enhanced if these data are not stored in the mobile station.
From the private data or service provider, the security is improved because authorized mobile station user are listed in the private directory database of the corporation or organization, and two particular fields (i.e. the user mobile station number and the user unique identifier) are checked for authentication. Additionally, the response message is sent back to the originating mobile station number requesting the data/service. Security can be further enhanced if the request and response message are encrypted, particularly when routed on the telecommunication network.
It is understood that such private data or services can be, as an example, corporate data or corporate services offered by a company to selected employees. Corporate data can be data of a corporate directory such as lightweight directory access protocol (ldap) database (also called ldap directory). Such a database offers professional and/or personal data about employees of a corporation, or known or authorized persons of an organization. Such data can be name, employee number, employee unique identifier, alias, e-mail address, phone number, location, office number, personal picture, function, . . . etc. Corporate service can be for example technical data service, like providing an access to real-time data related to the corporate operations, e.g. providing measurement given by a remote sensor.
The message based authentication method of the invention provides a reasonable first-level identification and authorization of a mobile station user for accessing to private data or services which do not need a strong or high-level of security.
Also, the method is simple and easy to use for any kind of mobile station that supports SMS (short message services), EMS (enhanced message services) or MMS (multimedia message services) type message. Today SMS message and in a close future EMS and MMS message are/will be available for users outside their home networks when roaming on visited networks. Thus, the authentication mechanism based on standard text message can use the worldwide available mobile phone infrastructures and services.
Another advantage is that the method of the invention works independently of the mobile station identification and authentication of the network operators. Therefore, this method can be implemented smoothly without interfering in the phone network operation.
Other characteristics and advantages of the invention will be described in more detailed in the following description of the invention and in one practical example of application.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description, given by way of example, will be best understood with the accompanying drawings in which:
FIG. 1 represents schematically a system for implementing the authentication method of the invention;
FIG. 2 shows a flowchart representing the different steps of the authentication method of the invention;
FIG. 3 illustrates the layout of a request message of the SMS type.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates schematically the different elements of a system and their interaction for implementing the authentication method of the invention. This figure will be described in combination with FIG. 2 which represents the different steps of said authentication method.
In a first step 1 , the user of mobile station MS compose a request message on his mobile station. This request message can be formatted as a SMS, EMS or MMS type message and is written with a specific layout.
The request message comprises an authentication part and a data or service request part. Advantageously, the authentication part comprises a unique identifier of the mobile station user. The specific layout will be presented in more details with the description related to FIG. 3 below.
The request message is sent to a specific telephone number corresponding to the messaging gateway MG. The request message is routed across the telephone network N to the messaging gateway MG. The telephone network architecture, functionality and way of routing calls or message are well know by the man skilled in the art and therefore will not be further detailed. It is well known that the telephone network N can comprise, while not being limited to, a first mobile phone network GSM 1 of a first mobile telecommunication operator covering a first area, a second mobile phone network GSM 2 of a second mobile telecommunication operator covering a second area, and a public switched telecommunication network PSTN of fixed telecommunication operator. Said network N comprises at least one messaging center MC dedicated to manage and route SMS, or EMS, or MMS type message. Obviously, the structure, number of sub-networks and inter-connection can be more complex than what is shown on FIG. 1 . Each of these local networks are inter-connected to each other to provide local, regional, national and international communication to any user of mobile station having subscribe to roaming capability outside its telecommunication operator home network.
The messaging gateway MG will receive the request message. The messaging gateway is an interface between the network N and a private infrastructure PI. The private infrastructure PI comprises all the resources (internal network, server, computer, databases . . . etc) of e.g. a corporation or an organization. The private infrastructure PI shown in FIG. 1 comprises a processing server PS, a corporate directory database DB, a database or an equipment (e.g. a sensor) providing data D and a service node S. All other elements of this private infrastructure are omitted for sake of drawing clarity.
In a second step 2 , the received request message is routed by the messaging gateway to the processing server PS. The server separates the authentication part, the data or service request part, and the originating mobile station phone number from the request message. It is to be noted that originating mobile station phone number is tagged to the incoming message as indicated in ETSI standard TS 100 901 related to Technical realization of the Short Message Service (SMS) (GSM 03.40 version 7.4.0 Release 1998). Then the server check whether the user unique identifier of the authentication part is present on the private directory database DB.
Here, the processing server PS has two functions, one is to process the message and the other is to authenticate the message. As an alternative (not shown on Figures), it is possible to have a message processing server and a distinct authentication server. In this case, the message processing server role is only to separate the authentication part, the data or service request part, and the originating mobile station phone number from the request message, while the authentication server only performs a look-up request on the private directory database DB.
If the user unique identifier is not present in the private directory database DB, then an error sequence is generated by the processing server PS (step 3 ) and access to private data or services is denied. In this case, either a error response message is sent back to the mobile station, or alternatively not any response message is sent back to the mobile station in order to avoid possible unauthorized access through probing.
In case, the user unique identifier of the authentication part is present on the private directory database DB, the user mobile station number assigned to the user unique identifier and stored in the private directory database DB is retrieved from the database DB by the processing server PS (step 4 ) or alternatively by the authentication server.
This mobile station user number is recognized as being known and authorized to communicate with the corporation or the organization.
After this successful private directory look-up, a second checking is performed (step 5 ). This second check consists in comparing the user mobile station number attached to the request message with the user mobile station number assigned to the user unique identifier and stored in the private directory database DB.
It is to be noted that the user mobile station number is the cell-phone, mobile phone, feature phone or a smart-device number that is allocated and stored on the originating mobile station and allocated to this particular user in the ldap directory. As an example, this number is the assigned phone number of the SIM-card (SIM stands for Subscriber Identity Module) present in the mobile station for authorizing access to the telecommunication network.
If there is no match between the two mobile station number than an error sequence is generated by the processing server PS (step 6 ) and access to private data or services is rejected. In this case, either a error response message is sent back to the mobile station, or alternatively not any response message is sent back to the mobile station.
If there is a perfect match between the two mobile station number than the processing server PS performs the request for data or services asked by the user in the request message (step 7 ).
After the processing server obtains the requested information from either the private directory database DB, or the database/equipment D or the services node S, a response message is composed which includes the requested private data and send back to the user mobile station number (step 8 ) via the network N.
Depending of the request, either a SMS type message containing only text, or a EMS type message or a MMS type message containing image, video or graphics is sent back to the user.
The authentication method can be used for authenticated access to a range of private, or corporate data or services independently of the mobile station type and independently of the wireless telecommunication services provider. It is understood that a user/mobile station combination can access multiple data/services offered by different company or organization. In this case, the user/mobile station combination needs to be known from the different company or organization providing the data/services (i.e. at least the user mobile station number and user unique identifier needs to be stored in a corporate directory of each company or organization).
FIG. 3 illustrates a particular example of realization of the layout of a request message of the SMS type used by the method of the invention.
As described in ETSI standard TS 100 901 related to Technical realization of the Short Message Service (SMS) (GSM 03.40 version 7.4.0 Release 1998), a SMS type message can contain a maximum of 140 octets of data.
The SMS request message comprises three fields F 1 , F 2 and F 3 . In this example, the fields F 1 and F 3 correspond to the service request part SP of the message, while the field F 2 corresponds to the authentication part AP of the message.
The field F 1 can be a keyword for the service required on the remote private server PI, for example a ldap directory look-up service.
The field F 2 can be a keyword or a unique mobile station user identifier for the authentication of the mobile station user, for example a unique personal identifying alias of the ldap directory of the corporation.
The field F 3 can be a command, an action or a look-up request for data or services, for example contact details to be retrieved for a specified name in the ldap directory of the corporation.
As an alternative, the field F 1 can be omitted if a unique telephone number is assigned to each type of private service. This has also the advantage of simplifying the generation of the request message on the mobile station.
A first application using the method of authentication of the invention is the authentication of a user to query remotely a corporate ldap directory, namely to look up contact details of an employee in the company database.
As an example, a request message composed by the user Bob Jones for having contact details of a colleague Alice Smith would be:
“LDAP Bjones2 Alice Smith*” LDAP being the keyword for directory look-up service (field F 1 , Bjones2 being the alias or unique mobile station user identifier of Bob Jones in the corporate ldap directory (Field F 2 ), and Alice Smith* being the name of the person for which contact details are needed. The star * representing a wild card.
As an example, the response message will show the result of the corporate ldap directory look-up:
“Contact details for Alice Smith-Cooper: Tel: +23-4472-6468 Mobile: +23-6721-3234 Email: asmithcooper@corporation.com”
From the mobile station user perspective, the security is improved because the user knows the specific layout required to compose the request message and also its own unique identifier (alias).
From the private data or service provider, the security is improved because only a request message in the required layout with a matching unique mobile station user identifier/mobile station phone number combination can succeed the authentication checks.
Obviously, the request message is not limited to the particular layout described. The different fields F 1 , F 2 , F 3 , and the different parts AP, SP can be ordered and arranged differently. Nevertheless, it is necessary that both the user and the data/service provider use the same request message layout so that the service provider, in particular the processing server, is able to separate the authentication part from the service request part of the request message.
Also the content of the fields are not limited to what is described as an example. In particular, the user unique identifier is a data that identify the user uniquely. The user unique identifier can be the user alias, or any other uniquely identifying field allocated to this particular user in the ldap directory.
Advantageously, in order to further improve security, the request message and the response message can be ciphered by well known methods of the man skilled in the art which will not be describe (algorithms using symmetric or asymmetric keys).
A second application using the method of authentication of the invention is the authentication of a user to query technical or financial information on:
settings and status of remote system and equipment, namely temperature sensor, pressure sensor, valve, flow-rate sensor of an oil rig . . . etc; value of particular company share on the stock exchange market, PER, income, debt . . . of a company . . . etc.
A third application using the method of authentication of the invention is the authentication of a user to remotely control a system or an equipment. In this case, the field F 3 is a command like open, close, stop, start, adjust, set . . . etc, associated to an identification number of the system or equipment or part thereof to be controlled. | A method for accessing private data/services from a mobile station over a public network is described including: composing a text-based request message on the mobile station, sending the request message to a private server offering access to private data/services, and checking the authenticity of the user based on the request message received by the server. If user authenticity is confirmed, a text-based response message is composed and sent to the mobile station. The request message includes a user-unique identifier received by the private server with an appended user mobile station number. Authenticity checking (by the private server) includes checking whether (1) the user-unique identifier is stored in a private directory database, and (2) the appended user mobile station number matches the number allocated to the user-unique identifier stored in the private directory database. The interaction is limited to the exchange of pairs of text-based request message(s) and response(s). | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention covers the field of conveying technology and is concerned, in particular, with conveying printed products.
2. Description of Related Art
Apparatuses in the form of paddle wheels for transferring sheet-like products are generally known. They are used, for example in printing technology, to receive folded printed products coming from a rotary printing machine, or from the folding unit thereof, and to deliver them in imbricated form onto delivery belts arranged beneath the paddle wheel. The resulting imbricated formation can then be fed for further processing.
The products are fed to the paddle wheel usually from above or from the side, with the folding edge in front, and are discharged again approximately after a half revolution of the wheel, with the assistance of gravitational force, at the lowermost point of the path. A fixed-location stripping device is usually present in order to assist this process, the stripping device acting on the leading edge (folding edge) and pushing the product out of the compartment as the wheel rotates further.
In order for a constant imbrication spacing to be produced on the delivery belt, it is desirable for the movement of the product to be well-controlled as the products exit from the paddle wheel.
In order for a regular imbrication spacing to be produced, it is known, for example from EP-A 0 739 840, EP-A 1 510 488 or WO 98/16455, for controlled grippers to grip the printed products in the lower part of the movement path, shortly before they exit from the compartments of the paddle wheel, at their edge which rests on the base of the compartments (compartment base), i.e. at the leading edge, as seen in respect of the formation of products entering the paddle wheel. The grippers here also perform the function of the aforementioned stripper. The printed products secured by the grippers are removed from the paddle-wheel compartments on account of the movement of the gripper and paddle-wheel compartment relative to one another. Since the grippers accompany the compartments, or compartment bases, some way, the products are moved, and conveyed further, at the receiving location in the direction of circulation of the paddle wheel. The products are then deposited in imbricated form from above on a removal conveyor or transferred to a further gripper conveyor. The imbricated formation produced is one in which the leading edges—as in the original formation—are arranged upstream of the trailing edges. Since the grippers only act on the products in the lower part of the movement path of the paddle wheel, there is a risk of the products sliding out of the compartments in an uncontrolled manner, on account of gravitational force, before being gripped. This can also give rise to irregularities in the formation produced.
In order for it to be possible, in the case of such apparatuses, for the grippers to act on the leading edge, which is located in the region of the compartment base, the movement path of the grippers is located well within the paddle wheel, as seen in a plan view of the axis of rotation of the paddle wheel. The products are guided out of the compartments in the downward direction and conveyed further by the gripper conveyor beneath the paddle wheel and/or deposited, with the assistance of gravitational force, on a conveying belt arranged beneath the paddle wheel. This requires the apparatus as a whole (paddle wheel and conveying belt arranged therebeneath) to be of a certain minimal overall height. As seen in a projection of the axis of rotation of the paddle wheel, the circulatory path of the grippers, and of the drive means thereof, is located, at least in part, within the surface area of the paddle wheel. The gripper conveyor has to engage in the paddle wheel, which is mechanically complex.
A further disadvantage resides in the fact that the leading edge is gripped. At the exit of a rotary printing machine, the leading edge is usually the folding edge of the product. It is precisely in the case of relatively thick or multi-part printed products, prior to stitching or stapling, that gripping of the folding edge can result in product parts falling out. Moreover, the product, for the purpose of further processing, often has to be introduced into a further-processing station with the folding edge in front, e.g. it has to be introduced into an insertion or cutting drum in order for further products to be inserted or for the edge located opposite the folding edge to be cut. In such cases, therefore, engagement around the product is necessary, and this requires transfer to a further gripper conveyor or depositing and regripping operations. The additional component which is necessary for engaging around the product renders this practice complex and expensive.
ER-A 0 265 735 discloses the practice of evening out the products, in order to produce a constant imbrication spacing, by action on their trailing edges once they have been removed from the compartments. For this purpose, a conveying belt with an auxiliary conveyor is arranged beneath the paddle wheel, and this auxiliary conveyor moves in the same direction as the direction of circulation at the receiving location. The auxiliary conveyor has a plurality of clamping elements. The products are pushed out of the compartments of the paddle wheel in the downward direction on account of gravitational force, and with the assistance of strippers acting on the leading edges, and end up located in an imbricated formation on the conveying belt. The clamping elements serve as a stop for the trailing edges of the already deposited products and clamp the same firmly against the conveying belt. They thus ensure a constant spacing of the trailing edges on the conveying belt. Once the product has been evened out in this way, the clamping elements are removed and the products are conveyed further in the evened-out imbricated formation.
As in the case in the above described apparatuses, there is the disadvantage here that the products can slide out of the compartments in an uncontrolled manner. For this reason, the known apparatus has guide elements for the products, e.g. lateral directing plates or supporting belts, which are intended to support, in particular, the trailing edges. It is, thus, not possible to prevent slipping of product parts, for example of different formats, within a product. Moreover, the conveying belt moves in the same direction as the paddle wheel in its lower region. It is, thus, also the case here that the role of the leading and trailing edges in the exiting formation remains unchanged in relation to the original formation.
It is, thus, an object of the invention to reduce the disadvantages described above. In particular, the intention is to provide a method and an apparatus which make it possible for products, in particular folded printed products, to be transferred in a well-controlled and reliable manner between a paddle wheel and a further conveying device.
BRIEF SUMMARY OF THE INVENTION
The method according to the invention and the apparatus according to the invention, both for conveying sheet-like products, in particular printed products, proceed from the fact that the products are introduced into compartments of a circulating system, these compartments moving along a closed circulatory path, at a transfer location in a manner known per se, with their leading edge in front. The circulating system is a paddle wheel like that in the prior art cited above. The products are fed preferably in a feed direction which corresponds to the orientation of the compartments as they pass the transfer location. Since compartment bases are spaced apart from the axis of rotation of the paddle wheel and the compartments are open in a direction other than the radial direction, pronounced acceleration and changes in direction of the product during transfer are avoided and the products are therefore treated very carefully. The leading edge is usually—but not necessarily—a folding edge of a printed product. If the product is folded a number of times, the leading edge is, in particular, the final folding edge. The products are conveyed further, by way of their compartments, to a receiving location, for example by rotation of the paddle wheel. Individually fed products. here are usually braked in comparison with the conveying speed of the feed conveyor by being rearranged into a more compact formation as they are introduced into the circulating system. If they have been fed already in a compact formation, e.g. an imbricated formation or in small stacks, they are usually separated as they are introduced into the compartments. Following passage through part of the circulatory path of the compartments, e.g. following rotation of the paddle wheel through 60 to 180°, the products are received at the receiving location by grippers of a gripper conveyor and are conveyed away by the same. According to the invention, the trailing edge is gripped here. The products are preferably oriented here such that the trailing edge is located above the leading edge, that is to say the product is supported, on account of gravitational force, on the compartment base and thus assumes a well-defined position prior to, and as it is, being received. As a result of the movement of the compartment and gripper relative to one another, the product is released from the circulating system and can be conveyed further by the gripper conveyor.
The practice of gripping the trailing edge, which is preferably a non-folded, open product edge, has the advantage that it can be realized in a space-saving manner, which is straightforward in design terms, without any complicated interengagement of the circulating system and gripper conveyor. The grippers can act, in particular in the immediate vicinity of the compartment openings, on the trailing edge of the product arranged in the respective compartment, in which case the products are optimally supported by the compartment wall until being gripped. For adaptation to various formats, the compartment bases or a stripper which is preferably present, and acts on the leading edge butting against the compartment base, may be adjustable, in which case the receiving operation can take place always at the same location.
The practice of gripping the trailing edge has the additional advantage of, in particular, folded printed products being moved into a position which is optimal for further processing. They can be introduced into an insertion or cutting drum for example with the folding edge in front, in which case the open edge (“bloom”), which is located opposite the folding edge, can be processed. A further advantage resides in the fact that gripping of the product at the open edge means that it is not possible for any constituent parts of the product to fall out.
Finally, the fact that the products are present within the circulating system, usually already in a separated state, is utilized in order for them to be conveyed further, and processed further, individually by way of the gripper conveyor. If required, it is also possible for two or more products to be introduced into one compartment and into one gripper.
The invention has the further advantage that it is possible to compensate for timing inaccuracies in the fed formation which have not already been compensated for by the circulating system or which arise within the circulating system. This is because the grippers are conveyed preferably at a constant spacing and grip the products always at the same location, while the latter are still essentially fully supported by the compartments and are, thus, positioned in a very well-controllable manner.
Paddle wheel is understood as being any conveyor with a plurality of compartments which move along a circular path and into which the products are inserted without necessarily being actively fixed. Active fixing (e.g. clamping), however, is possible. The paddle wheel, for example, is a rotary body which has one or more compartments or pockets which can receive products and convey them along a circular path as a result of the rotary body being rotated above an axis of rotation. The aforementioned paddle wheels (star wheels) can usually be rotated about a horizontal axis. The compartment base is spaced apart from the axis of rotation by a certain spacing r which is greater than zero, in order for it to be possible for the products to be pushed out of the compartments, in dependence on the rotary position, by action on the leading edges. The compartments open at an angle relative to the radial direction, counter to the direction of circulation, in which case the leading edge of the products is located upstream of the trailing edge, as seen in the direction of circulation of the paddle wheel. The compartments are located, for example, one above the other in an imbricated manner in cross section, in order to achieve the greatest possible conveying capacity. These observations are also transferrable to differently configured circulating systems. The compartments are fastened for example, to conveying means, e.g. a chain or a cable, and are moved by a drive along the circulatory path at a constant or variable spacing. It is preferred, but not necessary, for the circulatory path of the circulating system to be located in a vertical plane.
In an advantageous variant of the invention, the leading edge of a product, during conveying through the circulating system, at least until the product is gripped, is located beneath the trailing edge of the product. This has the advantage that the position of the leading edge, on account of gravitational force, is defined at any point in time by the position of the compartment base or of a stripper which may be present. The situation where the product slides out of the compartment or is displaced within the compartment on account of the gravitational force is prevented. A defined position of the leading edge means that the position of the trailing edge is also well defined at any point in time of the movement operation. The trailing edges are gripped directly, in this defined position, by the grippers, which, for this purpose, are located in particular above, or to the side of, the circulating system and approach the same from above. The conveying direction and speed of the gripper conveyor are adapted to the conveying direction and speed of the circulating system. After the product has been gripped, the leading edge may also be located above the trailing edge, since the product position is then well defined by the gripper.
The products are introduced into the compartments in a state ranging from preferably essentially horizontal (trailing edge directed toward the feed means) to upright (trailing edge at the top). When they are gripped at the receiving location, the products are located in a position ranging from upright (trailing edge at the top) to approximately horizontal (trailing edge directed toward the gripper). The above described orientation of the leading and trailing edges means that there is no need for any additional elements in order to fix the products in the compartments.
In order to achieve the described orientations of the product, the conveyor for feeding the products and the gripper conveyor for conveying the products away are arranged such that the products are transferred, and respectively received, at a point in time after, or respectively before, the compartments are inclined such that the leading edge (or a point on the compartment base) would be located beneath the trailing edge (or a point in the opening region of the compartment). The transfer location is located, for this purpose, preferably in an upper region of the circulating system. The receiving location is located, for this purpose, usually vertically beneath the transfer location. The receiving location is located preferably laterally alongside the circulating system, as seen in the plan view of the axis of rotation. This also has the advantage of a low overall height, and a more straightforward design, of the apparatus, since the movement paths of the compartments (or the opening regions thereof) and of the grippers have to overlap only to a slight extent, if at all.
The transfer location, i.e. the location at which the products are transferred to the compartments of the circulating system, and the receiving location are preferably arranged, and the compartments are preferably formed, such that the horizontal position of the leading edge and of the trailing edge is swapped over between the transfer location and receiving location by the movement of the compartments along the circulatory path of the circulating system. That is to say that, as seen from the receiving location, the leading edge is located horizontally upstream of the trailing edge at the transfer location and in the region of, or downstream of, the trailing edge at the receiving location. The product executes a kind of switchback turn during conveying. This easily makes it possible without any great acceleration, and thus without the products being adversely affected, to produce formations in which the (originally) trailing edge is leading, as seen in the conveying direction of the gripper conveyor, and/or in which the products are arranged in a hanging, and thus spatially compact, state. This has advantages, as explained in the introduction, for the further processing of the products. It also gives rise to better accuracy in the exit formation since the compartment base acts as a stop and the opposing edge (trailing edge) is gripped. This is more precise than the operations of gripping the edge butting against the compartment base and of conveying away in the direction of circulation of the compartment.
The products can be conveyed to the circulating system, for transfer to the circulating system, individually, in an imbricated formation and/or in small stacks. The products come, for example, directly from a rotary printing machine, from an interim store (e.g. product roll) or from some other upstream process.
The operation of the product being received by the grippers is preferably assisted in that the products are displaced relative to the compartment, counter to gravitational force, e.g. by action on the leading edges by means of a stripping device, in which case they project a little way out of the compartment and can be gripped more easily. For a product position which is stable at all points in time, the amount by which the products project out of the compartment, preferably in relation to the overall length of the product, is small, particularly preferably smaller than a quarter, to smaller than a tenth, of the overall length of the product. The stripping device can be displaced preferably for adaptation to different product formats, in order to achieve the situation where the trailing edge, despite different product lengths, is always located in the same position in the region of the receiving location.
A monitoring device preferably serves for monitoring the formation of products which is fed to the circulating system, in particular for determining irregularities or defective products. This monitoring device may be, for example, an optical sensor. The monitoring device communicates with a control device by emitting a corresponding signal, for example when a product arrives or in the presence of an irregularity or of a defective product. The control device uses this signal to control the movement of the circulating system and/or of the gripper conveyor and/or of the gripper, in particular with the aim of compensating for defects and irregularities in the exiting formation produced by the gripper conveyor. For example, when each product arrives, the monitoring device emits a clock signal to the control device, and this signal serves for controlling the circulatory movement of the circulating system and of the gripper conveyor. In another variant, the circulating system and gripper conveyor are driven synchronously in the customary manner, but the circulatory speed, on account of a signal from the monitoring device, is adapted in a controlled manner in order to compensate for, for example, gaps (e.g. brief standstill period). In a further variant, the grippers are activated individually in order for, for example, defective products to be specifically deflected rather than picked up. A corresponding method has already been described in Swiss Patent Application No. 1806/07, which was not published before the priority date and to which reference is made here. In all cases, the control device is connected in control terms to the drive of the circulating system and/or of the gripper conveyor and/or of any controllable guide tracks, and can transmit signals to these components.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of the invention will be described hereinbelow and are illustrated in the drawings, in which, purely schematically:
FIG. 1 shows an apparatus according to the invention with a paddle wheel as the circulating system, as seen in a side view of the axis of rotation of the paddle wheel, during processing of products of a first format;
FIG. 2 shows the apparatus from FIG. 1 during processing of products of a smaller, second format;
FIG. 3 shows the operations of folded products being conveyed by the gripper conveyor and transferred to a belt conveyor; and
FIG. 4 shows the operations of folded products being conveyed by the gripper conveyor and processed further in an insertion or cutting apparatus.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows, schematically, an apparatus 10 according to the invention with a paddle wheel 20 as the circulating system, with a gripper conveyor 30 and with a feed conveyor 40 , as seen in a projection of the axis of rotation D of the paddle wheel 20 .
The paddle wheel 20 has a plurality of compartments 22 which are defined by supporting/separating elements 23 which are curved slightly convexly relative to the axis of rotation D. The separating elements 23 wind around the axis of rotation D in the manner of a very elongate helix. The walls 26 , 27 of a compartment 22 are defined by the facing surfaces of two adjacent separating elements 23 . The separating elements 23 run toward one another and in this way, and/or by way of a connecting piece, define the compartment base 24 . The compartment bases 24 are spaced apart from the axis of rotation D approximately at a constant spacing r. The compartments 22 open counter to the direction of rotation of the paddle wheel, which in this case rotates in the clockwise direction. Located in the region of the lower half of the paddle wheel 20 is a horizontally displaceable stripping device 28 which does not circulate along with the paddle wheel and has a guide surface 29 which is curved in the upper region and, for the rest, is oriented approximately vertically. The stripping device 28 can be displaced in the horizontal direction by means of a suitable drive 28 ′.
The feed conveyor 40 here is a belt conveyor, which has the products 12 resting individually on its conveying belt. It is likewise possible for small stacks or an imbricated formation to be fed by the feed conveyor. The front region 42 of the feed conveyor 40 projects into the paddle wheel 20 . For this purpose, the feed conveyor 40 and/or the separating elements 23 are/is of interrogating configuration. The location at which the products 12 are introduced into the compartments 22 is denoted as transfer region A. The transfer region A is located just upstream, as seen in the direction of rotation, of the upper vertex S of the movement path U of the compartments 22 , approximately at the “11-o-clock” position. U is used here to denote, by way of example, the movement path of a radially outer point on the separating elements 23 . The feed direction F is predetermined by the orientation of the belt conveyor. The orientation of the compartments 22 (e.g. orientation of the trailing compartment wall 26 ) corresponds, in the transfer region A, approximately to the feed direction F.
The gripper conveyor 30 has a plurality of individually controllable grippers 32 which are moved along a closed circulatory path U′. U′ is used here to denote, for example, the movement path of drive means (not illustrated specifically here) to which the grippers 32 are connected. The grippers 32 can be pivoted relative to the circulatory path U′ in a manner known per se by means of suitable guide tracks. It is likewise possible for the position of the two gripper jaws 34 , 35 , e.g. open or closed gripper mouth, to be set using suitable guide tracks. The gripper 32 , for this purpose, has control elements 36 , 37 in the form of control rollers, which interact with the aforementioned guide tracks in order for the gripper 32 to be closed, opened and/or pivoted. The region in which the grippers 32 are closed is also denoted as receiving location B. The receiving location B is located to the side of the paddle wheel 20 , approximately at the “3-o-clock” position. It is located vertically beneath the transfer location A.
A supporting surface 50 is located beneath the gripper conveyor 30 .
The function of the apparatus will be described hereinbelow: at the transfer location A, the products 12 of product length L, as measured between the leading edge 14 and trailing edge 16 , are introduced into the compartments 22 with their leading edge 14 in front, in which case the leading edge 14 is located in the region of the compartment base 24 and the trailing edge 16 is located in the region of the compartment opening 25 . The compartments 22 are oriented in the region of the transfer location A such that the compartment base 24 is located beneath the front end 42 of the feed conveyor 40 . The spacing r from the axis of rotation means that the compartment base 24 , as the product 12 is being received in the compartment 22 , and after it has been received therein, moves initially with a movement component in the original conveying direction F. The product 12 , immediately after having been introduced into the compartment 22 , is thus moved further essentially in its original conveying direction F, and it is only as the paddle wheel rotates further that it is subjected gently to a change in direction. Pronounced acceleration is thus avoided.
As they are conveyed further in the compartments 22 , the products 12 butt, in the first instance, against the trailing compartment wall 26 , as seen in the direction of revolution, and, as movement progresses, against the leading compartment wall 27 , as seen in the direction of revolution. In this position, they reach the receiving location B. The position of the latter is selected such that the leading edges 14 , at least until the products 12 are gripped by the grippers 32 , are located beneath the trailing edges 16 . In other words, the compartments 22 are oriented between the transfer location A and receiving location B such that the compartment bases 24 are located beneath the compartment openings 25 . The grippers 32 are moved in an open state to the receiving location B and are closed there. As they approach the receiving location B, they can engage slightly, by way of their gripper jaws 34 , 35 , between the compartment walls 26 , 27 , and this allows them to be closed together as they approach. However, the actual receiving operation by virtue of the gripper 32 being closed takes place, in the present example, outside the circulatory path U and/or outside the surface area which is covered over by the paddle wheel 20 , as seen in a plan view of the axis of rotation D thereof. There is therefore no need for the compartment walls 26 , 27 to have any recesses for engagement of the grippers 32 . The stripping device 28 serves to push the products 12 a little way out of the compartment, counter to gravitational force, by action on the leading edges 14 , which are initially located on the compartment base 24 , and this means that the trailing edges 16 are moved into the region of the grippers 32 , or of the distal ends of the gripper jaws 34 , 35 and can be gripped securely there. The products 12 are, thus, in a well-defined position at any point in time during the movement operation.
Once gripped, the products 12 are drawn out of the compartments, and conveyed further, by the gripper conveyor 30 . It is possible here to produce a spatially very compact formation made up of separated products 12 conveyed in a hanging state one beside the other. At least immediately following gripping, the trailing edge 16 is located upstream of the leading edge 14 , as seen in the conveying direction of the gripper conveyor 30 . The roles of the leading and trailing edges 14 , 16 have thus been swapped over in relation to the original formation.
It is also possible, as shown here schematically, for the products 12 to be supported at the hanging-down (originally) leading edge 14 by a supporting surface 50 . The supporting surface 50 may also be the conveying belt of a further belt conveyor, on which the products can then also be deposited in their entirety. This makes it possible for the products to be carefully rearranged (leading edge becomes the trailing edge, and vice versa). This is shown by way of example in FIG. 3 .
The control device 70 serves for synchronizing the movement of the feed conveyor 40 , circulating system 20 and gripper conveyor 30 . It optionally receives, from a monitoring device 72 a signal which serves for adapting the movements of these components in the manner mentioned in the general part of the description. It is thus possible to compensate for irregularities or to eject defective products.
FIG. 2 shows the apparatus from FIG. 1 during processing of products 12 of a product length L′, which is smaller than the product length L of the products from FIG. 1 . These products 12 likewise end up located with their leading edge 14 on the compartment base 24 . The shorter product length L′ means that the trailing edge 16 is positioned further into the compartment 22 . The stripping device 28 can be displaced in a horizontal direction in order to compensate for the differences in length of the products 12 such that the operation of the products being received by the grippers 32 can take place at always the same position.
FIG. 3 shows the transfer of the products 12 to a belt conveyor 52 , of which the conveying belt constitutes the aforementioned supporting surface 50 . The latter moves in the same direction as the grippers 32 of the gripper conveyor 30 arranged above. The products 12 are conveyed in a hanging position downstream of the receiving location B, wherein the (originally) leading edge 14 rests on the supporting surface 50 and is arranged downstream of the gripped (originally) trailing edge 16 , as seen in the conveying direction of the gripper conveyor 30 . A triggering element 38 opens the grippers 32 at a discharge location C. This results in an imbricated formation in which the open (originally) trailing edges 16 are leading, and rest on the preceding product 12 , being produced on the conveying belt.
The removal of the products 12 from the paddle wheel 20 by way of grippers 32 gives rise to a precisely timed imbricated formation as the products are being received and, consequently, also as they are deposited.
FIG. 4 shows the transfer of the products 12 from the gripper conveyor 30 to an insertion or cutting drum 60 . The grippers 32 are opened by a triggering element 38 at a discharge location C, in which case the products 12 fall downward into compartments of the insertion or cutting drum 60 . The folded open (originally) leading edge 14 is located on the compartment base and the (originally) trailing edge 16 is located in the region of the opening of the compartment, and thus in the correct position for the cutting operation. It is thus possible, using little outlay, to achieve the correct product position in order for it to be possible for the desired processing to be carried out. | A method and to a device for conveying planar products ( 12 ), particularly folded printed products. At a transfer point (A), the products ( 12 ) are inserted with the leading edges ( 14 ) thereof ahead into compartments ( 22 ) of a revolving system ( 20 ) in the form of a paddle wheel, the compartments moving along a closed revolving path (U), and removed from the compartments ( 22 ) at a transfer point (B) by way of grippers ( 32 ) of a gripper conveyor ( 30 ) and conveyed away. The products are seized by the grippers ( 32 ) at the trailing edges ( 16 ). The seizing of the trailing edge ( 16 ), which preferably is not the folded open product edge, has the advantage that it can be implemented without a complicated engagement of the revolving system ( 20 ) and gripper conveyor ( 30 ) and that the further conveyance and further processing of the products ( 12 ) are simplified. | 1 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a camshaft with a carrier shaft which can be mounted rotatable in a shaft axis, wherein at least one cam pack is disposed axially displaceable on the carrier shaft, and wherein the cam pack comprises at least two cams and at least one adjusting member for the axial adjustment of the cam pack.
Such camshafts are used for internal combustion engines, which can be operated with an adjustable valve lift or with adjustable valve control times. The valves of the internal combustion engine are controlled by means of cam packs, which are disposed axially displaceable on the rotating carrier shaft. The valves can be controlled with different cams by the axial displacement of the cam pack on the carrier shaft, wherein the different cams can have different cam shapes. The cam lobes can be more or less geometrically pronounced or the position of the cam lobes can be varied relative to one another in the circumferential direction. Cams are also known that are constituted as zero-lift cams.
Cam packs comprise a plurality of cams, wherein at least one adjusting member is a component of the cam pack, by means of which the axial displacement is introduced into the cam pack.
There is known from DE 10 2009 022 657 A1 a camshaft with a carrier shaft, which can be mounted rotatable in the shaft axis in order to be operated in an internal combustion engine. Disposed on the carrier shaft is a cam pack, which is constituted for example by four cams. The cam pack comprises a carrier tube, which is disposed axially displaceable on the carrier shaft by means of an inner toothing and an outer toothing, so that the rotary motion of the carrier shaft is transmitted via a geometrical form-fit connection to the carrier tube. A plurality of cams is disposed on the carrier tube, so that the cam pack comprises four cams with two different cam contours. For the axial displacement of the cam pack, the carrier tube comprises axial stops, in which curved paths are introduced on the external periphery, said curved paths being able to cooperate with a transmission element.
DE 10 2004 011 586 A1 shows a further camshaft with a carrier shaft, and a carrier tube is shown which is constituted in one piece with a plurality of cams. The carrier tube comprises an inner toothing, which engages with an outer toothing of the carrier shaft in order to dispose the cam pack in an axially displaceable manner on the carrier shaft, and at the same time to produce a rotary transmission of the carrier shaft to the cam pack by means of a geometrical form-fit connection. The carrier tube comprises a bearing element between the cam contours in order to mount the cam pack rotatable in a bearing block, which can for example be a component of the cylinder head.
The camshafts according to the prior art disadvantageously comprise cam packs which necessitate a carrier tube in an assembled variant in order to combine various control elements and adjusting members with a cam pack, or which have to be produced in solid form. The carrier tube serves for the mounting on the carrier shaft and comprises the necessary inner toothing which can engage with the outer toothing on the carrier shaft. Disadvantageously, an expensive design arises due to the use of a carrier tube for mounting the cams and adjusting members, and the cams have to be disposed with a necessary jointing technique on the carrier tube. If the carrier tube and the cams and also, for example, the adjusting member are constituted as a whole in one piece, a component arises which is expensive to produce and on which a large number of processing operations have to be carried out. However, it is technically advantageous to be able to carry out individually both the machining and heat treatment of various elements of the cam pack.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention consists in providing a camshaft with a cam pack, which overcomes the aforementioned drawbacks of the prior art and has a simple structure, wherein the various elements of the cam pack can also be machined and heat-treated individually.
This object is solved proceeding from a camshaft with a carrier shaft which can be mounted rotatably in a shaft axis, wherein at least one cam pack or package is disposed axially displaceably on the carrier shaft and wherein the cam pack includes at least two cams and at least one adjusting member for the axial adjustment of the cam pack. The cams and the at least one adjusting member are connected to one another in an axially adjacent configuration by an integrally molded body. The body is integrally molded on at least one cam and the adjusting member by an original molding process and a composite structure is formed by the integrally molded body. The composite structure is able to be mounted in a direct configuration on the carrier shaft so as to be axially displaceable on the latter. Advantageous developments of the invention are given in the dependent claims.
The invention includes the technical teaching that the cams and the at least one adjusting member are connected to one another in an axially adjacent arrangement by means of an integrally moulded body, wherein the body is integrally moulded on at least one cam and the adjusting member by an original moulding process and wherein a composite structure is formed by means of the integrally moulded body, said composite structure being able to be mounted in a direct arrangement on the carrier shaft so as to be axially displaceable on the latter, wherein the cams and the adjusting member comprise an inner toothing which engages in an axially displaceable manner with an outer toothing of the carrier shaft.
The invention proceeds from the idea of connecting the individual control elements of the cam pack directly to one another in order to constitute the cam pack without the use of a carrier tube. As a result of the direct connection of the cams and of the at least one adjusting member to the cams disposed adjacent to the latter, in the general idea of the invention also each element participating in a cam pack, the use of a carrier tube becomes unnecessary, and the cams and the at least one adjusting member can be disposed axially displaceable directly on the carrier shaft. As a result of the direct connection of the cams to one another and of the adjusting member to the cams disposed adjacent to the latter, a composite structure of individual elements is created which can be machined individually before being connected jointly to one another. After the composite structure comprising the cams and the adjusting member has being created, the latter can be disposed directly on the carrier shaft without further use of a carrier tube or any other element.
In order to produce the composite structure, at least one and preferably a plurality of cams and the adjusting member are connected to one another, i.e. for example cast with one another, by means of the integrally moulded body. For this purpose, the body can be integrally moulded on the at least one cam and the adjusting member by means of an original moulding process, as a result of which the integrally moulded body forms a stable, mechanically loadable connection between the cam and the adjusting member.
The body can be integrally cast on the at least one cam and on the adjusting member in an injection moulding process or in a die-casting process, wherein the material of the body preferably comprises aluminum, magnesium or plastic. For example, if the material comprises plastic, the body can be injection moulded on the at least one cam and the adjusting member in an injection moulding process. If the material comprises magnesium and/or aluminum, a metal die-casting process for example can be used. As an alternative to a casting method, the integrally moulded body can also be integrally moulded on the at least one cam and the adjusting member in a sintering process, e.g. from a granulate or a powder.
Within the scope of the invention, provision can also be made such that, for example, only the connection between two or more of cams is produced with the integrally moulded body.
The invention offers the particular advantage of constituting the cams and the adjusting member with an inner toothing, which can engage in an axially displaceable manner with an outer toothing of the carrier shaft and can at the same time transmit torques in the circumferential direction. The inner toothing is preferably introduced directly into the cams and/or into the adjusting member in order to dispose the cam pack already formed with the cams and/or the adjusting member in an axially movable and rotation-transmitting manner on the carrier shaft. As a further advantage, it is possible for example for only outer elements, for example a first outer cam and a mutually opposite second outer cam, to be constituted with an inner toothing, which can engage with a, for example, continuous outer toothing on the carrier shaft. The advantage is thus obtained that only two elements of the cam pack have to be constituted with an inner toothing, which preferably terminate the cam pack on the outside. Further elements of the cam pack, which are disposed between the elements disposed on the outside with the inner toothing, can optionally comprise further inner toothings.
As a further advantage, at least one latching groove can be introduced into at least one of the cams, but preferably in the adjusting member, said latching groove being able to cooperate with a latching means for the axial latching of the cam pack, said latching means being disposed in the carrier shaft. The latching means can for example be a spring-loaded ball, which is pressed into the latching grooves. Defined axial positions of the cam pack can thus be defined by the axial adjustment, wherein the number of latching grooves preferably corresponds to the number of cams of differing cam contour. The latching grooves can be introduced particular advantageously into elements of the cam pack that are not constituted with an inner toothing.
The cams and the adjusting member can be connected to one another at least over partial regions of their respective end faces. The end faces can be formed by plane faces, with which the shaft axis forms a surface normal. Once the cams and the adjusting member are brought flat one against the other in an axially adjacent arrangement, the connection can be made between the cams and/or the adjusting member. The connections can be constituted particularly advantageously as firmly bonded connections.
The firmly bonded connections between the cams and the at least one adjusting member and the cams adjacent thereto can be carried out by means of weld joints, and weld joints can be disposed for example on the outer periphery and/or on the inner periphery. The weld joints can be produced for example with a laser beam welding method or with an electron beam welding method, in order to minimize the thermally influenced material zone in the cams and/or in the adjusting member. Furthermore, the thermal distortion of the pack arrangement of the cam pack can be minimized by these welding methods. The weld joint can be produced particularly advantageously with the formation of a vapour capillary, in order to produce a particularly deep weld between the end faces of the cams and/or the adjusting member, so that the weld joint is capable of withstanding particularly high mechanical loads.
According to a possible embodiment of the invention, the firmly bonded connections between the cams and the at least one adjusting member can be carried out by means of solder joints and/or adhesive joints. In principle, finish machining of the functional surfaces of the cams and/or the adjusting member can take place after the firmly bonded connections are have been produced between the cams and/or the adjusting member.
As a further advantage, the connections between the cams to one another and the adjusting member to the cams disposed adjacent thereto can be constituted by at least one and preferably a plurality of tie rods distributed uniformly on the periphery of the cam pack, said tie rod or rods extending through the cams and the adjusting member. The tie rods can be constituted by threaded bolts or suchlike and can take up a tensile stress after arrangement in the cam pack. The cams and the adjusting member are consequently pressed axially against one another in order to form a mechanically loadable composite structure comprising the cams and the adjusting member. Alternatively, it is also conceivable to connect the cams to one another and the adjusting member to its adjacent cams by means of one or more rivet joints. As a further advantage, the cams and the adjusting member can for example be pinned together, or form-fit geometries can be provided on the end faces of the cams and the adjusting member in order then to pass the tie rods through the cams and the adjusting member and thus to place them under tensile stress.
As a further possible embodiment of the invention, the connections of the cams and of the at least one adjusting member to its adjacent cams can be constituted in each case by at least one jointing element acting in a form-fit manner which is preferably disposed on the cams and/or at least one adjusting member or is constituted between the end faces. The jointing elements acting in a form-fit manner can be constituted in one piece with the cams and/or the adjusting member or can even be moulded onto the latter. For example, threaded joints, bayonet joints, undercut joints or other joints can be provided between the cams and/or the adjusting member, or jointing elements such as slot nuts or suchlike are provided. In principle, any possible connection embodiment can be provided between the cams and/or the adjusting member in order to connect the latter to one another in a mechanically loadable manner. The connection of the cams and/or the adjusting member should preferably be able to be produced free from play, and the connection should maintain the rotational position of the elements around the common shaft axis.
According to a further advantageous embodiment, the cam pack can comprise at least one bearing element, which is preferably constituted for the formation of a zero-lift cam. A zero-lift cam comprises a cylindrical lateral surface, wherein the bearing element can have an axial width which enables both the bearing of the cam pack by means of the bearing element as well as the simultaneous active connection of the bearing element to a tappet of the valve control. The bearing element can also be connected by means of the integrally moulded body to at least one cam and/or to the adjusting member.
According to an advantageous development of the camshaft according to the invention, a plurality of cams can comprise at least one multiple cam element, wherein at least one multiple cam element is connected to the adjusting member by means of the integrally moulded body in an axially adjacent arrangement with respect to the adjusting member, and the multiple cam element comprises a plurality of cam contours preferably differing from one another. The multiple cam elements can comprise a through-bore, in which the inner toothing is introduced. Consequently, a plurality of cams can be provided uniformly and comprising one component as a result of the multiple cam elements for the production of the cam pack. The integrally moulded body can be integrally moulded, in particular integrally cast, integrally injected or integrally moulded in the die-casting process, between the multiple cam elements and the adjusting member, so that a connection arises between the multiple cam elements and the adjusting member.
According to a further advantageous embodiment, the adjusting member can be constituted at least in two parts, wherein a first part of the adjusting member is constituted by a control contour element and a second part of the adjusting member is constituted by the integrally moulded body. Introduced in the control contour element is a control path, which cooperates with an external element in order to displace the cam pack axially along the shaft axis on the carrier shaft.
The multiple cam element can comprise a jointing section, wherein at least one jointing section of a multiple cam element is introduced at least partially into the control contour element constituted ring-shaped, and wherein the integrally moulded body connects the jointing section and the control contour element to one another. In particular, the material of the integrally moulded body fills the radial gap between the jointing section of the multiple cam element and the inner side of the control contour element. The integrally moulded body can be constituted wider in the direction of the shaft axis than the control contour element, so that the control contour element is embedded in the integrally cast body and is thus accommodated by the latter. At the same time, a mechanically loadable connection between the control contour element and the multiple cam element arises as a result of the integrally moulded body, so that the integrally moulded body forms both a part of the adjusting member and a means for connecting the adjusting member to the multiple cam element. In the same way, the integrally moulded body can also form a part of the adjusting member, and can also connect the control contour element to the cam body.
A form-fit shoulder can be disposed on the jointing section of the multiple cam element, so that a form-fit connection between the adjusting member and the multiple cam element is formed with the integrally moulded body at least in the direction of the shaft axis. The form-fit shoulder can for example constitute a collar at the end of the jointing section of the multiple cam element, said collar being cast around or encapsulated by the integrally moulded body.
In addition or as an alternative, a number of holes can be introduced into the jointing section, in which holes the material of the integrally moulded body engages in a form-fit manner. A form-fit connection can thus be produced between the integrally moulded body and the jointing section, said connection being capable of withstanding high mechanical loads.
An advantageously constituted cam pack can be formed especially when a first multiple cam element with a first to jointing section is disposed on a first side of a control contour element and a second multiple cam element with a second jointing section is disposed on a second, opposite side of the control contour element, so that the two multiple cam elements are connected to one another by the integrally moulded body, and wherein in particular the control contour element is embedded in the integrally moulded body for the formation of the adjusting member. The integrally moulded body thus forms a connecting body between the adjusting member and a first and a second multiple cam element. The jointing sections of the mutually opposite multiple cam elements can abut against one another with their end faces, and form-fit shoulders are integrally moulded at the end on the jointing sections, said form-fit shoulders thus forming a common collar, which is surrounded by the material of the integrally moulded body and thus forms a connection in a form-fit manner between the two multiple cam elements.
The invention further relates to a cam pack comprising at least two cams and at least one adjusting member for the axial adjustment of the cam pack on a carrier shaft, wherein the cams and the at least one adjusting member are connected to one another in an axially adjacent arrangement by means of an integrally moulded body, wherein the body is integrally moulded on at least one cam and the adjusting member by an original moulding process and wherein a composite structure is formed by the integrally moulded body, said composite structure being constituted for direct arrangement on the carrier shaft, wherein the cams and the adjusting member comprise an inner toothing, which can be engaged in an axially displaceable manner with an outer toothing of the carrier shaft. The advantages and embodiments of the aforementioned camshaft with a corresponding cam pack are also taken into account for the generic cam pack.
The invention further relates to a method for producing a camshaft with a carrier shaft which can be mounted rotatably in a shaft axis, wherein at least one cam pack is disposed axially displaceable on the carrier shaft and wherein the cam pack comprises at least two cams and at least one adjusting member for the axial adjustment of the cam pack, wherein according to the invention the method comprises at least the steps of the arrangement of at least two cams in a position adjacent to the adjusting member, the integral moulding of a body on the at least one cam and the adjusting member by means of an original moulding process, so that a composite structure comprising at least one cam and the adjusting member is formed and comprises the direct arrangement of the composite structure on the carrier shaft, wherein the cams and the adjusting member comprise an inner toothing, which is engaged in an axially displaceable manner with an outer toothing of the carrier shaft.
The method can be carried out by means of an original moulding tool, and the at least one cam and/or the at least one multiple cam element as well as the adjusting member are introduced into the original moulding tool in an axially adjacent arrangement with respect to one another. The introduced components can be fixed in their position in the original moulding tool, so that the latter already occupy a position which corresponds to the subsequent position for the formation of the cam pack. The material of the integrally moulded body can then be introduced into the original moulding tool, for example by an injection moulding process or a die-casting process. After hardening of the integrally moulded body, the composite structure thus formed can be removed from the original moulding tool. For example, finish machining of the components can then also take place. Thus, for example, provision can be made such that the cams are ground and polished in their assumed position in the composite structure of the cam pack in order to create a final cam contour.
Instead of an already complete adjusting member, the described method can be carried out with a control contour element, and the integrally moulded body forms beside the control contour element a further part for the completion of the adjusting member. As an alternative to individual cams, at least one multiple cam element can also be provided, and the multiple cam element is disposed in the original moulding tool in an axially adjacent arrangement with respect to the adjusting member or the control contour element, so that the material for forming the integrally moulded body is then added. Particularly advantageously, two multiple cam elements can comprise respective jointing sections, which are disposed in the original moulding tool pointing towards one another along a common shaft axis. An adjusting member and preferably a control contour element can also be introduced in the region of the jointing plane, in which the multiple cam elements point towards one another with their jointing sections and lie adjacent to one another with their end faces, so that the material for the formation of the integrally moulded body is then introduced, and preferably injected or cast, into the radial region between the approximately ring-shaped control contour element and the jointing sections of the multiple cam elements.
The method can further comprise the introduction of an inner toothing into the cams and/or into the adjusting member in order to engage in an axially displaceable manner with an outer toothing on the carrier shaft. The inner toothing is introduced directly into the material of the cams and/or of the adjusting member. According to a further method step, there is introduced into at least one cam and/or into the adjusting member at least one latching groove, which can cooperate with a latching means, which is disposed in the carrier shaft, for the axial latching of the cam pack.
According to a possible embodiment of the method according to the invention, the inner toothing can be introduced in each case individually into the cams and into the adjusting member, the cams and the adjusting member only being mutually jointed subsequently in an axially adjacent arrangement.
Alternatively, the cams and the adjusting member can be mutually jointed in an axially adjacent arrangement, the inner toothing only then being introduced into the cams and into the adjusting member. In the same way, the at least one latching groove can be introduced before or after the jointing of the cams and the adjusting member with one another.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Further features improving the invention are represented in greater detail below with the aid of the figures, together with the description of preferred examples of embodiment of the invention. In the figures:
FIG. 1 shows a cross-sectional view through a camshaft with a cam pack, which is constituted with the features of the present invention,
FIG. 2 shows a cross-sectional view of a cam pack according to a first example of embodiment for the formation of the connections between the cams and the adjusting member,
FIG. 3 shows a cross-sectional view of a cam pack according to a second example of embodiment for the formation of the connections between the cams and the adjusting member,
FIG. 4 shows a cross-sectional view of a cam pack according to a further example of embodiment for the formation of the connections between the cams and the adjusting member,
FIG. 5 shows a further example of embodiment of a cam pack, which comprises a bearing element for the mounting in a bearing,
FIG. 6 shows a further example of embodiment of a cam pack, which comprises an integrally moulded body according to the invention
FIG. 7 shows the example of embodiment of the cam pack according to FIG. 6 in an exploded view.
DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of embodiment of a camshaft 1 with a cam pack 12 , which is constituted with the features of the present invention. Camshaft 1 comprises a carrier shaft 10 , which is shown interrupted in the seating region of cam pack 12 . Carrier shaft 10 can be mounted rotatably in a shaft axis 11 , for example in the cylinder head of an internal combustion engine.
Cam pack 12 comprises for example six cams 13 , 14 , 26 , 27 , 28 and 29 , wherein an adjusting member 15 is provided, and a groove guide 30 is introduced in adjusting member 15 on the outer periphery of the adjusting member 15 . Cams 13 , 14 and 26 are located on a first side of adjusting member 15 , and cams 27 , 28 and 29 are located on an opposite, second side of adjusting member 15 . A through-bore, through which carrier shaft 10 is passed, extends through cams 13 , 14 , 26 , 27 , 28 , 29 and through adjusting member 15 . An inner toothing 16 is introduced in this through-bore formed by the individual components of cam pack 12 , said inner toothing engaging with an outer toothing 17 on carrier shaft 10 in an axially displaceable and torque-transmitting manner. Outer toothing 17 of carrier shaft 10 is constituted wider in the direction of shaft axis 11 than the width of cam pack 12 , and cam pack 12 can be adjusted axially in the direction of the shaft axis, whereby an adjusting element is guided in groove guide 30 of adjusting member 15 . As a result of the form-fit connection of inner toothing 16 and outer toothing 17 , a rotary motion of the carrier shaft 10 is at the same time transmitted to cam pack 12 .
Cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 are connected to one another in an axially adjacent arrangement with one another, so that, as a result of the connection of these components of cam pack 12 via their respective end faces constituted in the axial direction, a composite structure is created which forms cam pack 12 . According to the invention, this does not require a carrier tube on which the individual components such as cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 have to be disposed. Inner toothing 16 and latching grooves 18 can thus be introduced directly into cams 13 , 14 , 26 , 27 , 28 , 29 and into adjusting member 15 , wherein for example three latching grooves 18 are introduced on the inside into adjusting member 15 , which are able to cooperate with a latching means for the axial latching of cam pack 12 , said latching means being disposed in carrier shaft 10 in a manner not shown in detail.
Cams 13 , 14 , 26 , 27 , 28 , 29 each have different cam contours, for example cams 13 , 14 , 26 , 27 , 28 , 29 can have different cam lobes or the cam lobes are constituted at different angles around the circumference. As a result of the axial adjustability of cam pack 12 , tappets having a fixed axial position can cooperate with different cams 13 , 14 , 26 or 27 , 28 , 29 , in order for example to change the valve lift, but also for example to change the valve control times.
FIG. 2 shows a first example of embodiment for the formation of the composite structure of cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 . The connection is constituted by tie rods 22 , and by way of example two tie rods 22 are represented over the periphery of cam pack 12 , wherein in particular more than two tie rods 22 can be provided, which are disposed uniformly distributed on the periphery of cam pack 12 . Tie rods 22 extend parallel to shaft axis 11 through cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 and are placed under axial tensile stress. The components of cam pack 12 are thus pressed against one another at the end faces in order to form a mechanically loadable composite structure. Tie rods 22 can be constituted as screw elements or as dowel pins, in order to introduce a tensile stress into tie rods 22 .
FIG. 3 shows a further example of embodiment for the formation of cam pack 12 , wherein the connections between cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 are constituted by weld joints 19 , 20 . Weld joints 19 are constituted as weld joints on the outer periphery and weld joints 20 are constituted as weld joints on the inner periphery. Weld joints 19 and 20 constituted on the outer periphery and on the inner periphery are shown merely by way of example, wherein for example only weld joints 20 on the inner periphery may be sufficient to form a mechanically loadable composite structure of the components of cam pack 12 . Weld joints 19 and 20 can be produced for example by laser beam welding procedures or by electron beam welding procedures, in order to minimise the thermal effect on cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 .
FIG. 4 shows a further example of embodiment for the formation of cam pack 12 , wherein cams 13 , 14 , 26 , 27 , 28 , 29 are connected to one another and adjusting member 15 to adjacent cams 26 , 27 by solder joints 21 . Solder joints 21 can be prepared for example by soldering foils, which are disposed between the individual components of cam pack 12 and, after the arrangement of cams 13 , 14 , 26 , 27 , 28 , 29 and adjusting member 15 in an axially adjacent arrangement with respect to one another, cam pack 12 thus prepared can be brought to the solder melting temperature in order to finish solder joints 21 . As an alternative to shown solder joints 21 , adhesive joints can be provided between the components of cam pack 12 .
Finally, FIG. 5 shows a further embodiment of a cam pack 12 with an adjusting member 15 and cams 13 , 14 , 26 , 27 ′, 28 , 29 , wherein cam 27 ′ is also constituted as a bearing element 23 . The cam 27 ′ is constituted as a zero-lift cam and has a cylindrical outer circumference. Besides the tapping—not shown in detail—by means of a tappet for the valve control, cam pack 12 is mounted in a bearing block 24 , into which a bearing 25 is introduced. Cam 27 ′ thus performs both as a zero-lift function for the valve control as well as the function for the bearing of cam pack 12 . The connection between the components of cam pack 12 can be constituted according to the example of embodiment in FIG. 2 , in FIG. 3 or in FIG. 4 .
As a result, a cam pack 12 is created which can be constituted without the use of a carrier tube. Furthermore, the possibility remains of feeding the different components of cam pack 12 in each case individually to mechanical and/or thermal processing steps, the components only then being connected to one another to form a cam pack 12 .
Inner toothing 16 , which is introduced into cams 13 , 14 , 26 , 27 , 28 , 29 and into adjusting member 15 , can be introduced individually into the respective components before the creation of the jointing connections or inner toothing 16 is introduced into cam pack 12 when the jointing connections between the individual components have already been created.
FIG. 6 shows a cam pack 12 with which the features of the present invention are represented. Cam pack 12 has a structure comprising two multiple cam elements 35 and an adjusting member 36 . Each of multiple cam elements 35 comprises cams 32 , 33 and 34 , and the two multiple cam elements 35 are disposed adjacent to one another at their end faces along a common shaft axis 11 . Multiple cam elements 35 comprise on the inside inner toothings 16 , which do not extend continuously over the entire circumference of the through-bore in multiple cam elements 35 , but rather inner toothing 16 is constituted only over partial regions of the inner wall of multiple cam elements 35 . It is also possible for multiple cam elements 35 to lie opposite one another with their end faces, but not to make contact, but rather to have an axial spacing from one another, as a result of which weight advantages are obtained.
Adjusting member 36 is constituted by a control contour element 37 made of a metallic material, which has a ring-shaped embodiment. Control contour element 37 surrounds jointing sections 38 integrally moulded on multiple cam elements 35 , with which jointing sections multiple cam elements 35 lie adjacent to one another, so that jointing sections 38 extend roughly on the inside into control contour element 37 . To complete adjusting member 36 , the radial region between ring-shaped control contour element 37 and jointing sections 38 is filled with the material of a body 31 to be integrally moulded. The filling of the material can take place for example by means of a casting process in an original moulding tool, into which multiple cam elements 35 and control contour element 37 are introduced beforehand and positioned with respect to one another. The original moulding tool can comprise a tool mould with which the free surfaces of the integrally moulded body are defined.
After injection or casting of the material for the formation of integrally moulded body 31 , a mechanically loadable, firm composite structure arises with multiple cam elements 35 and control contour element 37 , by means of which composite structure cam pack 12 is formed in one part. In order to create a form-fit connection between jointing sections 38 of multiple cam elements 35 and the material of integrally moulded body 31 , collar-shaped form-fit shoulders 39 are integrally moulded at the edge-side end of jointing sections 38 , so that a geometrical form-fit connection between jointing sections 38 and integrally moulded body 31 is formed in the axial direction of shaft axis 11 .
The representation shows, merely by way of example, the connection between an adjusting member 36 and two multiple cam elements 35 , wherein only one multiple cam element 35 can be disposed with an adjusting member 36 . In the same way, a connection between an adjusting member 15 and one or more cams 13 , 14 , 26 , 27 , 28 , 29 can also be created with an integrally moulded body 31 , as they are represented for example in FIG. 1 .
FIG. 7 shows, in an exploded view, a cam pack 12 with two multiple cam elements 35 and a control contour element 37 , which together with a part of integrally moulded body 31 forms adjusting member 36 . Integrally moulded body 31 is represented detached, as a result of which the developing geometrical shape of body 31 can clearly be seen, without integrally moulded body 31 being assembled as an individual part. The example of embodiment shows multiple cam elements 35 with an inner toothing 16 and cams 32 and 33 , which are located on the outer periphery of multiple cam elements 35 . Multiple cam elements 35 also comprise holes 40 , and if multiple cam elements 35 are located in a position adjacent to one another with their end faces, holes 40 lie in the inner region of control contour element 37 . If the material of integrally moulded body 31 thus formed is then cast, the material of body 31 passes partially into holes 40 , as a result of which a geometrical form-fit connection arises between body 31 and multiple cam elements 35 . Likewise in this example of embodiment, form-fit shoulders 39 are shown on the end of multiple cam elements 35 , in order to create a further geometrical form-fit connection between shoulders 39 and the material of body 31 .
The invention is not limited in its implementation to the aforementioned preferred examples of embodiment. On the contrary, a number of variants are conceivable, which make use of the presented solution even with fundamentally different embodiments. All the features and/or advantages emerging from the claims, the description or the drawings, including structural details or spatial arrangements, may be essential to the invention both in themselves and as well as in the most varied combinations.
LIST OF REFERENCE NUMBERS
1 camshaft
10 carrier shaft
11 shaft axis
12 cam pack
13 cam, 13 a end face
14 cam, 14 a end face
15 adjusting member, 15 a end face
16 inner toothing
17 outer toothing
18 latching groove
19 weld joint on the outer periphery
20 weld joint on the inner periphery
21 solder joint
22 tie rod
23 bearing element
24 bearing block
25 bearing
26 cam
27 cam
27 ′ cam
28 cam
29 cam
30 groove guide
31 integrally moulded body
32 cam
33 cam
34 cam
35 multiple cam element
36 adjusting member
37 control contour element
38 jointing section
39 form-fit shoulder
40 hole | A camshaft includes a carrier shaft to be mounted rotatably in a shaft axis and at least one cam pack axially displaceable on the carrier shaft. The cam pack includes at least two cams and at least one adjusting member for axial adjustment of the cam pack. The cams and adjusting member are interconnected in an axially adjacent configuration by an integrally molded body. The body is integrally molded on at least one cam and the adjusting member by an original molding process and a composite structure is formed by the integrally molded body. The composite structure can be mounted in a direct configuration on the carrier shaft to be axially displaceable thereon. The cams and the adjusting member include inner toothing engaging in an axially displaceable manner with outer toothing of the carrier shaft. A cam pack and a method for producing a camshaft are also provided. | 5 |
[0001] The present invention relates to a vehicle tailgate or door opening switch, of the type manually actuated by the user in order to open the lock of the opening leaf (door or tailgate), after the lock has been unlocked by means of the corresponding catch.
PRIOR ART OF THE INVENTION
[0002] Switches applicable in the tailgate and side doors of vehicles are known, these switches comprising a flexible membrane, in particular made of a black elastomer, which surrounds a microswitch. When the user presses the flexible membrane with his fingers, he actuates the microswitch and a corresponding relay causes the lock to open.
[0003] As an example, Spanish patent application No. 99/00840, the proprietor of which is the same as that of the present application, discloses a switch for a vehicle door in which the lock is opened by means of a microswitch; the switch comprises a case provided with an opening closed by a membrane, by means of which a user presses on an actuating bar, the displacement of which acts on the contact of the microswitch.
[0004] Although these switches operate satisfactorily, they do have the drawback that, when the user has to open the door of the vehicle at night or in a dark place, it is difficult for him to locate the position of the switch and of the membrane that he has to press.
DESCRIPTION OF THE INVENTION
[0005] The objective of the opening switch of the present invention is to remedy the drawbacks of the devices known in the prior art, by proposing for this purpose a switch that can be located and actuated easily under low-light conditions.
[0006] The switch of the present invention comprises means for actuating a lock, said means comprising a plastic or elastomeric membrane which is pressed in order to actuate the lock, and is characterized in that the plastic or elastomeric membrane is at least partly translucent and in that a light source is housed inside the switch.
[0007] Thanks to these features, the user locates the switch more easily. Moreover, the translucent membrane allows the light source in the switch to be located and avoids having to modify in any way the body of the vehicle, so that this solution is inexpensive.
[0008] In addition, the fact of placing the light inside the switch allows it to be better protected and makes its simpler to mount it.
[0009] Said membrane is preferably at least partly transparent.
[0010] In one embodiment, the membrane is a single part and is translucent or transparent in its entirety.
[0011] In an alternative embodiment, the membrane is only partly translucent or transparent; in this case, the membrane may be formed from two parts joined together.
[0012] Advantageously, the switch furthermore includes means for turning said light source on, said means being associated with a catch for unlocking the lock.
[0013] As a consequence, the light is turned on only when the user actuates the remote control in order to effect the unlocking operation, before acting on the switch, without unnecessary consumption of energy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] To make the description of what has been explained above easier to understand, a drawing is attached in which one practical embodiment of the switch of the invention is shown schematically and solely by way of non-limiting example, in which:
[0015] [0015]FIG. 1 is a view of the inside part of the opening switch of the invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0016] As may be understood from FIG. 1, the switch of the invention, applicable for example to a vehicle tailgate or door, comprises a case, identified by the reference 1 , provided with conventional elements allowing it to be fitted into the vehicle and containing a microswitch 2 . Said case 1 furthermore includes a membrane 3 , the outer face of which has a plurality of projections 4 which make it more pleasant to touch.
[0017] Inside the case 1 is also a rigid plastic part 6 constituting the actuator of the switch 2 . Said part initially remains separated from the microswitch 2 by two resilient elements 7 placed on each side of the entire switch of the invention. When the user presses the flexible membrane 3 , the part 6 is pushed toward the microswitch 2 and a corresponding relay causes the lock to open. As soon as the user stops exerting pressure on the membrane 3 , the part 6 returns to its initial position, thanks to the abovementioned resilient elements 7 .
[0018] Inside the switch is also, in accordance with the invention, a small lamp 5 that provides sufficient light to be visible from the outside, so as to indicate the switch under low-light conditions.
[0019] To do this, in accordance with the invention, the membrane 3 , which may be made of a plastic or an elastomer, is translucent.
[0020] In the present specification, the concept of “translucency” refers to the ability of allowing light to pass, and it also encompasses in this regard the concept of “transparency”.
[0021] The membrane may be translucent or transparent in its entirety, or else it may comprise only a translucent or transparent region through which light can pass; in the latter case, the membrane may be made from a single part or else may have two parts joined together.
[0022] In one embodiment, the light of the device is turned on when the user unlocks the lock, for example by means of the remote control; to do this, the switch has suitable actuation means, these being connected for example to the same electronic control element that unlocks the lock.
[0023] The supply source for the lamp 5 is the battery of the vehicle, which in turn supplies the microswitch 2 . The inclusion of the lamp in the switch therefore requires no substantial modifications of the latter since the battery voltage is already present in this region.
[0024] The materials employed in the manufacture of the constituent elements of the opening switch that has just been described are independent of the subject matter of the present invention, just as the shapes and dimensions of the latter, together with all the ancillary details that it is likely to have, which may be replaced with other technically equivalent elements without in any way departing from the scope of the protection defined in the claims appended hereto.
[0025] As an example, although a lamp was mentioned as light source, this could be replaced with any other type of illumination, for example LEDs or the like. | A switch that is used to open vehicle rear doors or openings comprising means for manually actuating the lock. Said means comprise a plastic or elastomer membrane ( 3 ) which is pressed by the user in order to actuate the lock. The plastic or elastomer membrane ( 3 ) is partially translucent and a light source ( 5 ) is housed inside the switch. | 7 |
[0001] The present application is underlayerd on and claims priority of Japanese patent application No. 2007-327596 filed on Dec. 19, 2007, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the invention
[0003] The present invention relates to a semiconductor manufacturing apparatus for manufacturing semiconductor devices, and more specifically, relates to a dry etching technique for etching semiconductor materials such as silicon and silicon oxide films using plasma into profiles corresponding to a mask pattern formed of a resist material and the like.
[0004] 2. Description of the related art
[0005] In the art of dry etching, material gas is introduced into a vacuum reactor having an evacuation means, and the material gas is turned into plasma via electromagnetic waves so as to expose the sample being processed to plasma to etch the areas of the surface of the sample being processed not covered by a mask, to thereby obtain the desired profile. High frequency voltage independent from plasma generation is applied to the sample being processed, and via the high frequency voltage, ions in the plasma are accelerated toward the surface of the sample being processed, by which the etching efficiency is improved and a perpendicular processing profile is obtained (refer for example to Japanese Patent Application Laid-Open Publication No. 2002-184766, hereinafter referred to as patent document 2).
[0006] In the art of dry etching, an endpoint detection for judging whether the etching of a predetermined quantity has been completed or not is normally performed by observing the plasma emission. Actually, the end point detection is performed by monitoring the quantity of emission of the reaction products of the material being etched in the plasma or the underlayer material exposed when etching is completed. However, from viewpoints of improvement of etching accuracy and reduction of costs by simplified processes, there are demands for not completing the etching when the underlayer material is exposed, but for stopping the etching process in midway of etching a single material or immediately prior to completing the etching.
[0007] According to such demands, the end point detection of etching cannot be performed by monitoring the emission from plasma as described above, but must be performed by monitoring either the etching quantity of the material being etched directly or the residual film thickness. A method for monitoring the etching quantity of the material being etched or the residual film thickness includes receiving light reflected on the surface of the sample being processed from plasma or from an independently-disposed light source, so as to analyze the interference pattern of the light accompanying the reduction of the material being etched on the surface of the sample being processed (refer for example to Japanese Patent No. 3643540, hereinafter referred to as patent document 1).
[0008] In etching apparatuses for etching insulating film materials such as silicon oxide films, a shower plate formed of a conductor such as silicon is disposed on an opposite side of the sample being processed, and high frequency power is applied to the whole body of the conductor including the shower plate to generate plasma. Thus, it is necessary to arrange a light transmitting unit to a conductor electrode portion opposed to the sample being processed, so as to monitor the etching quantity by performing analysis of the interference pattern of light accompanying the reduction of the material being etched. In general, a light transmitting unit has a structure to conduct light to the exterior of the vacuum reactor via a light guide rod formed for example of quartz or sapphire, and then to conduct the light via an optical fiber to a light interference pattern analysis unit composed for example of a spectroscope.
[0009] If the light guide formed for example of quartz or sapphire as the light transmitting unit is exposed directly to the shower plate surface formed for example of silicon, the end surface of the light guide rod is consumed by accelerated ions from the plasma or is subjected to deposition, making it impossible to receive light in an extremely short time. In order to overcome the problem, patent document 1 discloses a structure in which a plurality of penetrating holes 115 B through which plasma cannot pass are formed to a portion of the silicon shower plate, and an optical transmitting rod 141 is arranged on the rear side of the shower plate.
[0010] According to the prior art example having the above-described structure, it becomes possible to significantly elongate the life for receiving light compared to when the light guide rod is directly exposed to plasma.
[0011] However, even by adopting the structure illustrated in patent document 1, it becomes difficult to receive light in approximately 100 to 200 hours of discharge time, which is an insufficient life according to the level of production performed in some semiconductor devices. Further, by taking measures such as reducing the diameter of the through holes formed to the shower plate and improving the aspect ratio, it becomes possible to extend the life of the light transmitting unit for some time, but the quantity of light passing therethrough is reduced, and the required accuracy cannot be ensured.
[0012] Further, in volume-production processes of semiconductors, it becomes necessary to replace the light guide rod when the light transmission rate of the rod is deteriorated. However, the prior art method has a drawback in that the replacement operation could not be performed easily.
SUMMARY OF THE INVENTION
[0013] The object of the present invention is to provide a plasma processing apparatus for determining the end point of etching by monitoring the etching quantity of the material being processed via light interference on the surface of the sample being processed, wherein a means is provided to realize both longer life of the light transmitting unit and ensured light receiving quantity, and to enable long-term stable operation and improved processing accuracy by accurately detecting the etching quantity.
[0014] The present invention provides a plasma processing apparatus comprising an upper electrode for supplying material gas into a vacuum reactor via a shower plate, a lower electrode opposed to the upper electrode on which is placed a sample being processed, and a detector for detecting light from a surface of the sample being processed via the shower plate, so as to process the sample by generating plasma between the shower plate and the lower electrode; wherein the detector comprises a light transmitting unit including a light guide into which the light is entered and a spectroscope for analyzing the light obtained through the light transmitting unit; and an end surface of the light transmitting unit through which the light is entered is positioned at a distance of five times or greater of a mean free path of a gas molecule within the vacuum reactor from an end surface of the shower plate facing the plasma.
[0015] Further, the present invention provides a light guide rod having a hollow structure in which a space is formed in the interior of the light guide rod. Further, the present invention provides a light guide rod having a convex shape so as to facilitate replacement of the light guide rod. Moreover, the rod may have a cylindrical member disposed within the hollow structure so as to prevent deposits from sticking to the light guide rod. Furthermore, the rod may have an insulating member disposed in the hollow structure so as to prevent abnormal plasma generation in the hollow structure.
[0016] The effects of the present invention are as follows. By arranging the end surface position of the light detecting unit at a distance of five times or greater of the mean free path of the gas within the vacuum reactor from the plasma boundary, it becomes possible to reduce the percentage of ions being accelerated from the plasma reaching the light transmitting unit directly in a collision less manner to 1/100 or smaller. Thus, it becomes possible to significantly suppress the consumption of the end surface of the light transmitting unit, and to elongate the life of the light transmitting unit to 1000 hours of discharge time or longer. Furthermore, by adopting a convex structure to the light guide rod, it becomes possible to reduce the operation time for exchanging rods to 1/10 or shorter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a view showing the basic structure of a plasma processing apparatus according to a first embodiment of the present invention;
[0018] FIG. 2 is a detailed explanatory view showing the structure of a light detecting unit according to the first embodiment of the present invention;
[0019] FIG. 3 is a view showing the multiples of mean free path and the ratio of molecules and atoms passing the distance in a collisionless manner;
[0020] FIG. 4 is a detailed explanatory view of the structure of a light detecting unit according to a first modified example of the present invention; and
[0021] FIG. 5 is a detailed explanatory view of the structure of a light detecting unit according to a second modified example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Now, the preferred embodiments of the present invention will be described with reference to the drawings.
[0023] FIG. 1 is a drawing showing the configuration of a plasma processing apparatus according to a first embodiment of the present invention, which illustrates an example in which the present invention is applied to a magnetic field UHF band electromagnetic radiation discharge-type plasma etching apparatus. FIG. 1 is a frame format showing the cross-section of the plasma etching apparatus according to the first embodiment.
[0024] In FIG. 1 , a processing chamber 100 is disposed in the interior of a vacuum reactor capable of achieving a vacuum degree of approximately 10 −6 Torr, and defines therein a space in which a substrate-shaped sample such as a semiconductor wafer is processed via plasma generated therein. An antenna 110 as plasma generating means for radiating electromagnetic waves is disposed on the upper portion in the interior of the vacuum reactor, and a lower electrode 130 on which the sample W such as a wafer is to be placed is disposed below the antenna 110 .
[0025] The antenna 110 and the lower electrode 130 are disposed in parallel and opposed to one another. A magnetic field forming means 101 composed for example of an electromagnetic coil and a yoke is arranged in the circumference of the processing chamber 100 , by which a magnetic field having a predetermined distribution and intensity is formed. By the interaction with the electromagnetic waves radiated from the antenna 110 and the magnetic field formed by the magnetic field forming means 101 , plasma is generated from the processing gas supplied to the interior of the processing chamber, and the generated plasma P is used to process the wafer W placed on the lower electrode 130 .
[0026] The processing chamber 100 is evacuated and pressure-controlled via an evacuation system 104 and a pressure control means 105 connected to the vacuum chamber 103 , and the inner pressure of the chamber can be controlled to a predetermined value, which, for example, is in the range between 0.5 Pa and 4 Pa. The processing chamber 100 and the vacuum chamber 103 are set to earth potential. The temperature of the side wall 102 of the processing chamber 100 is controlled for example to 50° C. via a temperature control means not shown.
[0027] The antenna 110 for radiating electromagnetic waves is composed of a disk-shaped conductor 111 , a dielectric body 112 and a dielectric ring 113 , and supported on a housing 114 which constitutes a portion of the vacuum reactor. A structural body or disk-shaped plate 115 is disposed on one side of the disk-shaped conductor 111 which comes into contact with plasma, which is opposed to a wafer W or a circular sample-mounting plane of the upper surface of the lower electrode 130 described in detail later on which the wafer W is placed. The plate 115 is a circular plate-shaped conductive member, and the plate is fixed to position with respect to the disk-shaped conductor 111 on the outer circumference-side thereof. The diameter of the substantially circular portion of the plate 115 facing the plasma in the processing chamber 100 is either the same or greater than the diameter of the circular wafer W or the sample mounting plane.
[0028] The processing gas for subjecting the wafer W to processes such as etching and film deposition is fed from a gas supply means 116 with a predetermined flow rate and mixing ratio, which is homogenized in the interior of the disk-shaped conductor 111 and fed into the processing chamber through a plurality of holes formed to the plate 115 . The temperature of the disk-shaped conductor 111 is controlled for example to 30° C. via a temperature control means not shown. An antenna power supply system 120 composed of an antenna power supply 121 , an antenna bias power supply 123 and a matching circuit/filter system 122 , 124 and 125 is connected via an introduction terminal 126 to the antenna 110 . The antenna power supply 121 supplies a UHF-band frequency power preferably between 300 MHz and 900 MHz, so as to radiate UHF-band electromagnetic waves via the antenna 110 .
[0029] The antenna bias power supply 123 applies a bias with a frequency of approximately 100 kHz or a few MHz to 10 MHz, for example, via the disk-shaped conductor 111 to the plate 115 , and controls the reaction on the surface of the plate 115 . Especially, in an oxide film etching process using CF-under layered gas, the material of the plate 115 is preferably formed of high-purity silicon or carbon, so as to enable control of the reaction of F radicals and CFx radicals on the surface of the plate 115 and to control the composition ratio of radicals. In the present embodiment, high-purity silicon is used for forming the plate 115 .
[0030] The disk-shaped conductor 111 and the housing is formed of aluminum, and the dielectric body 112 and the dielectric ring 113 is formed of quartz. The distance between the lower surface of the plate 115 and the wafer W (hereinafter referred to as gap) is 30 mm or greater and 150 mm or smaller, preferably 50 mm or greater and 120 mm or smaller. In the present embodiment, the frequency of the antenna power supply 121 is set to 450 MHz, the frequency of the antenna bias power supply 122 is set to 13.56 MHz, and the gap is set to 70 mm.
[0031] A lower electrode 130 is disposed to face the antenna 110 at the lower portion of the processing chamber 100 . On the upper surface or sample mounting surface of the lower electrode 130 is placed a wafer W, which is fixed thereto via an electrostatic chuck device 131 . A sample stage ring 132 formed for example of high-purity silicon is disposed on an insulating body 133 at the outer circumference portion of the wafer W. A bias power supply 134 for supplying bias power in the range of preferably 400 kHz to 13.56 MHz is connected via a matching circuit/filter system 135 to the lower electrode 130 , by which the bias power applied to the sample W is controlled.
[0032] In the present embodiment, the frequency of the bias power supply 134 is 800 kHz. Furthermore, an evacuation system 104 comprising a vacuum pump such as a turbo molecular pump is connected to the lower portion of the vacuum reactor disposed below the lower electrode 130 , which is communicated with the interior of the processing chamber 100 via a port disposed at the bottom portion of the processing chamber 100 . Through the operation of the evacuation system 104 , the gas, plasma and particles generated by products formed by the processes in the processing chamber 100 are evacuated to the exterior of the processing chamber 100 , and the interior of the processing chamber 100 is set to a pressure of a predetermined vacuum degree.
[0033] Next, a measurement port 140 disposed to measure the surface condition of the sample W, which is the substantial portion of the present embodiment, will be described. In the present embodiment, the measurement port 140 is attached by being inserted to the inner side of the antenna 110 facing the sample W, and through the multiple through holes formed to the plate 115 , the status of the thin film or the like on the surface of the wafer W can be measured from the perpendicular upper direction. Of course, the mounting position of the measurement port is not restricted to the middle area as described above, but can be one or more than two locations arranged in different positions such as on the circumference area.
[0034] An optical transmission means 151 such as an optical fiber or lens is disposed on the opposite side from the wafer W via the plate 115 of the measurement port 140 , and the optical information reflecting the surface condition of the wafer W, such as the direct light from the plasma P or the reflected light or interference light on the wafer W surface of the plasma P or the reference light such as the white light supplied into the processing chamber 100 are transmitted from the plate 115 via the optical transmission means 151 to a measuring equipment 152 composed for example of a camera, an interference film meter or an image processing apparatus for measurement. The measuring equipment 152 is controlled via a measuring equipment control/calculation means 153 , and further connected to an upper system controlling means 154 . The system controlling means 154 monitors and controls the status of the system via a control interface 155 .
[0035] The plasma etching apparatus according to the present embodiment is composed as above, and the actual process for etching silicon oxide films or the like using the present plasma etching apparatus is as follows.
[0036] At first, a wafer W, which is the object being processed, is carried into the processing chamber 100 from a sample transfer mechanism not shown, which is then mounted and attracted to the lower electrode 130 , and the height of the lower electrode is adjusted according to need to set the gap to a predetermined distance. Thereafter, the interior of the processing chamber 100 is vacuumed by the evacuation system 104 , while gases required for the etching process of the wafer W, such as C 4 F 8 , Ar and O 2 , are supplied from the gas supply means 116 with a predetermined flow rate and mixing ratio, such as 1000 sccm Ar, 43 sccm CHF 3 and 10 sccm CF 4 , through the plate 115 of the antenna 110 to the processing chamber 100 . At the same time, the interior of the processing chamber 100 is set to a predetermined processing pressure, such as 2 Pa.
[0037] On the other hand, a substantially horizontal magnetic field of substantially 160 Gauss corresponding to the intensity of an electron cyclotron resonance magnetic field with respect to the antenna power supply 121 with a frequency of 450 MHz is formed in the area below the plate 115 . Then, electromagnetic waves in the UHF band is radiated via the antenna 110 from the antenna power supply 121 , and plasma P is generated in the processing chamber 100 by the interaction with the magnetic field. Processing gas is dissociated and ion radicals are generated in the plasma P, and by further controlling the antenna bias power supply 123 and the bias power supply 134 , the wafer W is subjected to etching and other processes.
[0038] The input power of the respective power supplies are, for example, 300 W for the antenna power supply 121 , 200 W for the antenna bias power supply 123 and 160 W for the bias power supply 141 . Then, at the end of the etching process, the supply of power and processing gas are stopped and the etching is ended.
[0039] Optical information reflecting the plasma emission and the surface condition of the wafer W during the process is transmitted through the measurement port 140 via the optical transmission means 151 to the measuring equipment 152 where measurement is performed, then underlayerd on the measured result, a measuring equipment control/calculation means 153 performs calculation, transmits the result to the upper system control means 154 , and the plasma processing device system is controlled via a control interface 155 .
[0040] Next, the detailed structure of a measurement port 140 will be described with reference to FIG. 2 .
[0041] FIG. 2 is a cross-sectional view showing in enlarged view a portion of the measurement port 140 attached to the antenna 110 in the embodiment of FIG. 1 . As already described in FIG. 1 , the disk-shaped conductor 111 and the dielectric body 112 forming the antenna 110 is supported by the housing 114 , and a plate 115 is attached to the disk-shaped conductor 111 . A number of gas through holes 115 A are formed to the plate 115 , and processing gas is supplied into the processing chamber 100 through gas through holes 111 A formed at corresponding positions to the gas through holes 115 A on a disk-shaped conductor 111 disposed above and adjacently covering the plate 115 .
[0042] The gas through holes 115 A formed to the plate 115 are through holes having a diameter in the range of approximately 0.1 mm to 5 mm, for example, preferably approximately 0.3 mm to 2 mm, and the gas through holes 111 A formed on the disk-shaped conductor 111 are holes having an equal or greater diameter to the gas through holes 115 A, the diameter of which is in the range of approximately 0.5 mm to 5 mm, for example, preferably approximately 2 mm. The thickness of the plate 115 is approximately 3 mm to 20 mm, and in the present embodiment, the thickness thereof is 10 mm.
[0043] A plurality of through holes 115 B for receiving light which are cylindrical pores penetrated through the plate 115 are densely formed to the plate 115 at a position corresponding to the measurement port 140 disposed on the rear side of the plate. Above the opening on a rear side (side opposite from the plasma P) of the through holes 115 B for receiving light on the plate 115 is disposed a light guide 141 , which is placed at a position close to the rear side of the plate 115 either with a given gap therebetween, or with a minute gap therebetween so that the plate and the light guide are substantially considered to be in contact with each other, or mounted on the rear side.
[0044] The light guide 141 according to the present embodiment is composed of two parts that are separable into top and bottom portions, wherein the lower light guide 141 A has its lower end arranged to face or substantially contact the plate 115 , and the upper light guide 141 B is mounted in a vacuum-sealed manner to the housing 114 via a retention means 142 and a vacuum sealing means 143 A such as an O-ring. Then, an optical transmission means 151 such as an optical fiber or lens is disposed at the atmospheric end surface of the light guide 141 . The direct light from the plasma P or the reflected light and interference light form the surface of the wafer W of the plasma P are transmitted through the through holes 115 B for receiving light of the plate 115 , transmitted through the light guide 141 to the optical transmission means 151 , and further transmitted to the measuring equipment 152 for measurement.
[0045] The upper light guide 141 B is positioned between the lower light guide 141 A and the optical transmission means 151 to transmit the transmitted light or the optical information from the light guide 141 A to the optical transmission means 151 . The light guide 141 B is a cylindrical member formed of quartz having a stepped shape in which the lower diameter is greater, wherein the lower large-diameter portion is inserted to the stepped upper surface of the cylindrical opening with multiple steps and having a diameter formed to correspond to the diameter of the lower large-diameter portion, by which the vertical position thereof is determined. The light guide is further covered by a retention means 142 fit thereto from above, and then screwed and attached to the housing 114 being grounded to ground potential. During this attaching operation, an o-ring disposed around the large-diameter portion is pressed against the light guide 141 B by the engagement force by which the retention means 142 is screwed, by which the interior of the vacuum reactor is airtightly sealed from the exterior.
[0046] According to the present embodiment, the light guides 141 A and 141 B are cylindrical rods formed of quartz with steps and having multiple varying diameters. The diameter at the upper portion of the light guide 141 A is preferably between approximately 5 mm and 30 mm, and in the present embodiment, the diameter is 8 mm. The light guide 141 A has a cylindrical hole, in other words, a hollow structure or hollow space 141 C, that is recessed to a predetermined depth in the axial direction of the cylinder from the end surface that faces or opposes to the through holes 115 B for receiving light of the plate 115 when the measurement port 140 is attached thereto.
[0047] In the present embodiment, the inner diameter of the cylindrical hollow space 141 C is 6 mm, and the depth thereof is 15 mm. Similar to the gas through holes 115 A, the through holes 115 B for receiving light has a diameter of approximately 0.1 mm to 5 mm, preferably approximately 0.3 mm to 2 mm, and in the present embodiment, the diameter of the through holes 115 B is 0.5 mm. Further, a multiple number of through holes 115 B for receiving light should be provided so as to improve the measurement sensitivity. Seven through holes are provided in the present embodiment.
[0048] The area in which the through holes 115 B for receiving light are formed is within the opening on the lower end of the hollow space 141 C when the light guide 141 A is attached to the antenna 110 , and the outer edge of the hollow space 141 C of the light guide 141 A is arranged to surround the multiple through holes 115 B for receiving light. The hollow space 141 C can be formed by cutting and hollowing the interior of the cylindrically-shaped quartz material along the axis of the cylinder from one end to the other end, as according to the present invention, or by attaching a cylindrical member to a pipe-like member.
[0049] Further, the light guide 141 A is structured so that the outer diameter of the portion positioned toward the plate 115 is formed greater than the rod diameter (projected or convex structure) so as to facilitate the replacing operation of the light guide 141 A. According especially to the present embodiment, the lower end portion facing the plate 115 of the light guide is extended outward in a flange to form a flange portion 141 D having a diameter of 10 mm and a length of 1.5 mm. In order to prevent supplied gas from directly flowing into the hollow space 141 C of the light guide 141 , vacuum seal means 143 B and 143 C, such as o-rings, are disposed in the circumference of the light guide 141 .
[0050] In other words, an o-ring, which is the vacuum seal means 143 B, is disposed on the outer circumference of the side wall of the upper cylindrical portion or small-diameter portion, sealing the space between the side wall and the gas reservoir space at the inner side of the cylindrical conductor 111 . Further, an o-ring, which is the vacuum seal means 143 C, is fit to the outer circumference of the flanged portion 141 D and the inner wall of the cylindrical recess disposed on the lower surface facing the plasma of the disk-shaped conductor 111 , airtightly sealing the space between the disk-shaped conductor 111 and the gas through holes 111 A and 115 A. The two vacuum seal means 143 B and 143 C prevent the particles of gas supplied to the processing chamber 100 or particles from the gas and plasma in the processing chamber from entering the upper portion of the light guide 141 A and contaminating the interior of the antenna 110 or the surface of the light guides 141 A and 141 B.
[0051] Further, a cylindrical recess is arranged around the through hole at the lower surface of the disk-shaped conductor 111 into which the light guide 141 A is inserted, and when the light guide 141 A is inserted to the through hole of the disk-shaped conductor 111 , the flange portion 141 D is stored in the interior of the recess and the vertical position of the light guide is determined by the upper surface of the stepped portion 111 B of the recess. Moreover, an o-ring which is the vacuum seal means 143 C is fit to the recess of the disk-shaped conductor 111 at the outer circumference portion of the flange portion 141 D.
[0052] As described, when the plate 115 is supported and fixed at the outer circumference to the disk-shaped conductor 111 , the vacuum seal means 143 C is sandwiched and supported by the plate 115 , the upper or side surface of the stepped portion 111 D of the recess and the flange portion 141 D and pressed thereto, so as to seal the space between the interior of the light guide 141 C, the through holes 115 B for receiving light and the gas through holes 111 A and 115 A, and the vertical and horizontal position of the light guide 141 A is determined and fixed thereby.
[0053] Further, the material of the light guide 141 A and 141 B is selected from a group consisting of quartz, sapphire, YAG (yttrium-aluminum-garnet) and yttria crystal (Y 2 O 3 ), preferably sapphire, YAG and Y 2 O 3 . Sapphire, YAG and yttria crystal are expensive but generally not easily sputtered compared to quartz, and therefore, a longer life is expected by using these materials instead of quartz.
[0054] According to the present embodiment, light guide rods 141 A and 141 B are disposed to receive the reflected light from the wafer W via through holes 115 B for receiving light formed to the shower plate 115 and the hollow space 141 C. Further, the length of the hollow space 141 C is set so that the distance from the plasma P side of the shower plate 115 to the upper end of the hollow space 141 C of the light guide rod 141 A, that is, to the opposite end farthest from the plasma P via the plate, is five times or greater of the mean free path of the gas molecules under a gas pressure condition in the plasma generating atmosphere within the vacuum reactor 144 .
[0055] The through holes 115 B for receiving light formed to the shower plate 115 has a function to block plasma P. In the present embodiment, the diameter of each of the through holes 115 B for receiving light is 0.5 mm. This arrangement enables to prevent gas and charged particles in the plasma P from entering the hollow space 141 C. According to the present embodiment, the end surface of the light guide rod 141 disposed at the depth of the hollow space 141 C formed on the rear surface of the plate 115 from the processing chamber is arranged at a position sufficiently spaced apart from the plasma P. In other words, according to the present embodiment, the end surface of the light guide rod is disposed via the hollow space 141 C with a length of 15 mm.
[0056] Accordingly, the distance from the plasma P to the end surface of the light guide rod is 25 mm, which is seven to eight times the mean free path of the gas molecules in a 2 Pa atmosphere. Therefore, the end surface of the rod for introducing light is exposed to very little ion radiation, by which the chances of the end surface of the rod being consumed are reduced, so that the rod can have a longer life. As described, by forming a hollow space 141 C in the light guide rod 141 , the life of the light guide rod 141 can be extended, and since the light guide rod 141 is projected at the outer circumference portion, the operator can easily grip and handle the light guide 141 , by which the time required for the replacing operation of components can be shortened.
[0057] Further, since the inner diameter of the hollow space 141 C is approximately 5 mm or greater, the light guide rod 141 A can be cleaned easily for recycle, so that the cost of replacing the components can be reduced. According further to the present embodiment, the light guide 141 is divided into the lower light guide 141 A and the upper light guide 141 B. The light guides 141 A and 141 B are respectively inserted to the through holes of the disk-shaped conductor 111 and the housing 114 and supported within the antenna 110 , and the light guides are respectively determined of their positions on the surface of the stepped portion 111 B of the recessed portion and the stepped portion 114 A of the housing 114 .
[0058] By screw-engaging the retention means 142 , the upper light guide 141 B is pressed against the upper surface of the stepped portion 114 A by the vacuum seal means 143 A and the retention means 142 , by which the vertical position thereof is determined and retained. Further, the lower light guide 141 A is designed so that when the housing 114 is rotated upward to release the processing chamber 100 by which the plate 115 is separated from the disk-shaped conductor 111 , the lower light guide 141 A can be attached and detached substantially perpendicularly with respect to the antenna 110 or the disk-shaped conductor 111 . When the lower light guide 141 A is inserted to the through hole of the disk-shaped conductor 111 and the flange portion 141 D is fit to the stepped portion 111 B of the recess, and when the vacuum seal means 143 C on the outer circumference is mounted to the recessed portion and the plate 115 is attached, the upper surface of the flange portion 141 D opposing to the disk-shaped conductor 111 is positioned with respect to the surface of the stepped portion 111 B.
[0059] For example, the o-ring or vacuum seal means 143 C is positioned between the plate 115 and the flange portion 141 D to apply a force to press the flange portion 141 D toward the stepped portion 111 B of the disk-shaped conductor 111 (toward the upper direction when the housing 114 is closed), so as to hold the light guide 141 A between the disk-shaped conductor 111 (or the stepped portion 111 B thereof) and the vacuum seal means 143 C (or plate 115 ) and determine the vertical position thereof.
[0060] In this case, a minute gap is formed between the end surface of the flange portion 141 D facing the plate and the rear surface of the plate 115 , and the shapes of the stepped portion 111 B and the flange portion 141 D are designed so that the size of the gap does not cause abnormal electrical discharge by the electric field formed by the supplied high frequency. It is also possible to dispose the flange portion 141 D and the rear surface of the plate 115 to either contact one another or be closely arranged so that they are substantially considered to be in contact with one another, and to form a minute gap between the flange portion 141 D and the stepped portion 111 B of the disk-shaped conductor 111 small enough not to cause abnormal electrical discharge.
[0061] Moreover, the cylindrical light guides 141 A and 141 B having their vertical positions determined respectively are also positioned so that the space between the upper end surface and the lower end surface of the light guides 141 A and 141 B is small enough so as not to cause abnormal electrical discharge by the above-mentioned electric field formed via high frequency. According to such arrangement of positioning, it becomes possible to prevent the occurrence of abnormal electrical discharge in the gap formed between and around the light guides 141 A and 141 B, and also suppress the light in the processing chamber 100 passing through the through holes 115 B for receiving light and the hollow space 141 C and through the light guide 141 A to the light guide 141 B from being attenuated by abnormal reflections or inflections, by which the reliability of the light guide 141 is improved, along with the suppression of optical attenuation caused by contamination and damage of the interior of the hollow space 141 C by particles from the plasma P.
[0062] With reference to FIG. 3 , a collisionless passage ratio of molecules and atoms with respect to the multiple of mean free path will be described. The collisionless passage ratio of molecules and atoms is reduced exponentially with respect to the multiple of the mean free path. From FIG. 3 , when molecules and atoms pass approximately five times the distance of the mean free path, the percentage in which the molecules and atoms can pass the distance in a collisionless manner is 1% or less, meaning that most molecules and atoms experience collision within the gas phase and lose their initial kinetic energy. When the distance is approximately seven to eight times the mean free path, the percentage in which the molecules and atoms pass in a collisionless manner is 0.1% or smaller.
[0063] Thus, according to the arrangement illustrated in the present embodiment, the percentage of the ions accelerated in the plasma P and reaching the end surface of the light guide rod in a collisionless manner is 0.1% or smaller. According to the prior art method in which the end surface of the light guide rod is positioned immediately behind the shower plate 115 , the distance is two to three times the mean free path, meaning that according to FIG. 3 , the percentage of ions reaching the end surface of the light guide rod in a collisionless manner is approximately 5 to 15%. Therefore, according to the arrangement of the present embodiment, the percentage of ions reaching the end surface of the light guide rod in a collisionless manner is 1/50 to 1/150 the percentage thereof according to the prior art arrangement, so that according to the present invention, the life of the end surface of the light guide rod cab be extended significantly. As a result of actual evaluation, the arrangement of the present invention enables to ensure sufficient lighting quantity after a discharge time of 1000 hours, which is five times or greater than the prior art method.
MODIFIED EXAMPLE 1
[0064] A modified example of the present invention will now be described with reference to FIG. 4 . Similar to FIG. 2 of the first embodiment, FIG. 4 is a view showing the detailed structure of a measurement port 140 . FIG. 4 characterizes in that a pipe member 145 is disposed in the interior of the hollow space 141 C of the light guide rod 141 . The pipe member 145 is positioned inside the hollow space 141 C of the light guide rod 141 .
[0065] If the pipe member 145 is not arranged, the ions, molecules and atoms scattered in the hollow space 141 C stick to the side wall of the hollow space 141 C, by which deposits are formed on the side walls. The deposits stuck to the side wall will come off within a time shorter than the life of the end surface of the light guide rod 141 , causing contaminants that may interrupt the production processes of etching, by which the light guide rod 141 may have to be replaced. However, by placing a pipe member 145 in the hollow space 141 C of the light guide rod 141 , it becomes possible to attach the deposits such as scattered ions, molecules and atoms to the inner wall of the pipe member 145 , and to enable the replacement operation to be performed in a short time since only the pipe member 145 must be replaced.
[0066] Further, by creating a multilayered wall surface within the hollow space 141 C by placing the pipe member 145 , and by further forming patterns on the inner wall thereof so as to increase the surface area of the inner wall, it becomes possible to reduce the thickness of the deposits on the inner wall of the pipe member 145 , so as to extend the replacement life of the pipe member 145 . For example, if grooves with a width of 0.1 mm with an inner diameter of 4.75 mm are patterned on the pipe member 145 having an inner diameter of 4.5 mm and a length of 14.5 mm, the surface area of the inner wall will be increased from 230.5 mm 2 to 770 mm 2 , so that the surface area is increased by approximately 3.3 times, and if grooves with a width of 0.01 mm are patterned on the pipe member, the surface area becomes 5508 mm 2 , by which the surface area is increased by approximately seven times, and the life thereof is extended.
[0067] As described, the arrangement of the pipe member 145 enables to extend the life of the light guide rod 141 and to reduce the operation time required for replacing the components when particles are generated. Further, by extending the life of the light guide rod 141 , it becomes possible to reduce the costs of the replaced components. Further, it is possible to position at least one of the multiple through holes 115 B for receiving light to the area between the outer circumference of the inner wall of the hollow space 141 C on the end adjacent to the plate and the outer circumference of the end portion of the pipe member 145 , so as to allow particles from the plasma P to enter the space formed therebetween.
MODIFIED EXAMPLE 2
[0068] A second modified example of the present invention will be described with reference to FIG. 5 . FIG. 5 is a view illustrating the detailed structure of a measurement port 140 , similar to FIG. 2 of embodiment 1 . FIG. 5 characterizes in that an insulating member component 146 formed of a cylindrical quartz extended from the bottom portion of the hollow space 141 C toward the rear surface of the plate 115 is arranged in the interior of and in correspondence with the center axis of the hollow space 141 C which is a cylindrically recessed portion of the light guide rod 141 .
[0069] The cylindrical insulating member component 146 can be formed integrally when forming the main body of the light guide 141 A, or by inserting a separately formed cylindrical component to the hollow space 141 C of the light guide 141 A and assembling the components together. Further, it is preferable that a minute gap is formed between the leading end disposed toward the plate 115 of the insulating member component 146 and the rear surface of the plate 115 opposed thereto, and that no through holes 115 B for receiving light are positioned in this area on the rear surface of the plate 115 .
[0070] If there is no insulating member component 146 , according to some etching conditions (such as when the gas pressure is high, the power of the antenna power supply 121 is high, the power of the antenna high frequency power supply 123 is high, or the power of the bias power supply 141 is high), the electric field formed by the disk-shaped conductor 111 surrounding the light guide rod 141 may create a strong electric field (hollow electric field) in the hollow space 141 C.
[0071] This electric field may accelerate the ions in the hollow space portion 141 C and ionize the gas, by generating plasma in the hollow space 141 C. The electric field intensity is greatest at the center of the hollow space portion, so that by inserting an insulating member component 146 in this area, it becomes possible to suppress acceleration of ions and ionization, and to prevent the generation of plasma. Further, the life of the insulating member component 146 can be extended if no through holes for receiving light are formed immediately below the insulating member component 146 , so as to prevent ions from passing through the through holes 115 B for receiving light formed to the plate 115 toward the insulating member component 146 . Thus, the life of the light guide rod 141 can be extended effectively by inserting an insulating member component 146 and preventing abnormal plasma generation. | The invention provides a plasma processing apparatus for measuring the etching quantity of the material being processed and detecting the end point of etching using optical interference on the surface of a sample being processed, so as to simultaneously realize long life and ensure sufficient light to be received via a light transmitting unit, to enable long term stable operation and to improve the processing accuracy via accurate etching quantity detection. In a plasma processing apparatus for processing a sample being processed by generating plasma between a shower plate and a lower electrode, a detector for detecting light from a surface of the sample being processed via the shower plate includes a light transmitting unit composed of a light guide into which light is entered and a spectroscope for analyzing the light obtained by the light transmitting unit, wherein the end surface of the light transmitting unit through which light is entered is arranged at a distance of five times or greater of the mean free path of gas molecules within the vacuum reactor from the end surface of the shower plate facing the plasma. | 7 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a Reed-Solomon decoder. More particularly, the invention relates to a multi-mode Reed-Solomon decoder based upon the Peterson-Gorenstein-Zierler (PGZ) algorithm.
2. Related Art
The Reed-Solomon (RS) codes have a strong error-correcting ability for burst transmission errors. Therefore, the RS codes have been widely used for error correction in digital communication and storage systems such as the xDSL, the cable modem, between a processor and a memory, the CD and the DVD.
Among various RS decoding algorithms, the Peterson-Gorenstein-Zierler (PGZ) algorithm provides the simplest method for implementing a RS decoder for t≦3. This is a low-cost solution for such systems as the error control code (ECC) between a processor and a memory that requires smaller error-correcting ability. Unlike an iterated RS decoding algorithm, such as the Berlekamp-Massey algorithm, the main drawback of the conventional PGZ algorithm is that it can perform only single mode correction. In other words, the PGZ decoding circuit for t=3 cannot make t=1,2 correction. Therefore, a PGZ decoding circuit for t≦3 conventionally requires three sets of different circuits to compute the t=1, t=2, and t=3 corrections independently, as shown in the circuit block diagram of FIG. 2 .
Apparently, implementing three sets of hardware circuits in an IC is a burden for manufacturing cost and chip design. To implement the Reed-Solomon decoder using the conventional PGZ algorithm, individual hardware circuits for different error corrections are required (the number of error correction abilities t=0,1,2,3 . . . ). As the number of error codes increases, the required chip area also grows exponentially. This inevitably increases the manufacturing cost and lowers the efficiency of the hardware utility. In addition, the Reed-Solomon decoder has a finite field inverter (FFI), which occupies a large area and needs a long calculation time. With the increasing error-correcting abilities, the circuit design becomes very complicated. Moreover, the number of required finite field adders (FFA) and finite field multipliers (FFM) grows exponentially.
SUMMARY OF THE INVENTION
In view of the foregoing, the invention provides a VLSI architecture to build a multi-mode Reed-Solomon decoder that can perform all sorts of corrections using the PGZ algorithm.
An objective of the invention is to provide a multi-mode Reed-Solomon decoder that can make corrections in response to error situations based upon the PGZ algorithm.
Another objective of the invention is to provide a multi-mode PGZ decoder circuit in a VLSI architecture that has a lower cost and uses fewer area resources to solve various error correction problems.
A further objective of the invention is to provide an improved Reed-Solomon decoder based upon the PGZ algorithm that modifies the hardware circuit with error-correcting ability t=3, so that the circuit has the abilities to solve all t=0,1,2,3 errors.
For the implementation of a Reed-Solomon decoder based on the PGZ algorithm in the prior art, the VLSI architecture uses the redundant hardware circuits to achieve various types of error corrections (t=1, t=2, and t=3). The implementation requires a larger area and results in lowering the efficiency of hardware resources. Additionally, the implementation of the algorithm includes the operation of the FFI. This inevitably increases the complexity of the circuit calculation and deteriorates the calculation speed. Therefore, the invention ultilizes the derivation of the algorithm to obtain the disclosed Reed-Solomon decoder without requiring FFI. The occupied area resource is thus reduced, whereas the operation efficiency is enhanced. Furthermore, the invention improves the hardware circuit of the Reed-Solomon decoder with error-correcting ability t=3 based on the PGZ algorithm, so that it becomes a multi-mode PGZ decoder circuit that can process t≦3 error corrections.
In one embodiment of the present invention, a Reed-Solomon decoding method comprises the steps of: computing the syndromes of received data; solving the key equation; and evaluating error locations and error value, wherein the step for solving the key equation is based upon a simplified PGZ algorithm and a solution that does not need FFI in operations. This greatly reduces the complexity of the computation and the area resources occupied by the hardware. A multi-mode decoding method is employed to obtain the number of errors. Accordingly, the invention proposes a multi-mode PGZ decoding architecture that can process t=0,1,2,3 error corrections.
In another embodiment of the invention, the Reed-Solomon decoder comprising: a syndrome calculator to compute the syndromes of received data; a key equation solver to receive a syndrome equation from the syndrome calculator; and an error location and error value evaluator to receive the syndrome equation and obtain the error locations and error value. The key equation solver uses a simplified PGZ decoder as the basis thereof. The PGZ decoding architecture comprises FFA and FFM without requiring FFI. The PGZ decoder contains a multi-mode decoding controller for obtaining the number of errors so that the PGZ decoding architecture can process t=0,1,2,3 error corrections.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows a block diagram of the Reed-Solomon decoding procedure;
FIG. 2 is a circuit block diagram for the conventional PGZ decoding architecture that uses the duplicate hardware circuits to achieve error corrections;
FIG. 3 is a circuit block diagram of the multi-mode PGZ decoder with a single hardware to perform different error corrections according to one embodiment of the present invention;
FIG. 4 shows an RTL hardware architecture of the t=1 PGZ decoding architecture;
FIG. 5 shows an RTL hardware architecture of the t=2 PGZ decoding architecture;
FIG. 6 shows an RTL hardware architecture of the simplified t=3 PGZ decoding architecture according to one embodiment of the present invention;
FIG. 7 shows an RTL hardware architecture of the simplified t=3 PGZ decoding architecture that does not need FFI operations according to one embodiment of the present invention;
FIG. 8 shows a flowchart of the multi-mode decoding method according to one embodiment of the present invention; and
FIG. 9 shows an RTL hardware architecture of the multi-mode PGZ decoding architecture according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , a Reed-Solomon decoding procedure comprises computing the syndromes of a reception polynomial r(x) to obtain a syndrome polynomial S(x); solving the key equation to obtain an error location polynomial σ(x) and an error value polynomial ω(x) in accordance with the syndrome polynomial S(x); evaluating error locations and error value in accordance with the error location polynomial σ(x) and the error value polynomial ω(x); and correcting the errors in the received data in accordance with the error locations and the error value to obtain a transmitted codeword polynomial c(x).
In the above-mentioned procedure, the transmitted codeword polynomial c(x) and the reception polynomial r(x) can be related by the following expression:
r ( x )= c ( x )+ e ( x ), (1)
where e(x) represents the error pattern. The syndrome values S i obtained from α i in the reception polynomial r(x) can be expressed as:
S i = r ( α i ) = ∑ j = 0 n - 1 r j ( α i ) j , 1 ≤ i ≤ 2 t . ( 2 )
Therefore, the syndrome polynomial S(x) is defined as:
S
(
x
)
=
∑
i
=
0
2
t
-
1
S
i
+
1
x
i
.
(
3
)
The PGZ algorithm for solving the key equation includes the step of solving the Newton Identity:
[
S
2
S
3
…
S
t
+
1
S
3
S
4
…
S
t
+
2
⋮
⋮
⋰
⋮
S
t
+
1
S
t
+
2
…
S
2
t
]
[
σ
t
-
1
σ
t
-
2
⋮
σ
0
]
=
[
-
S
1
-
S
2
⋮
-
S
t
]
(
4
)
The syndrome values S i are used to solve for σ in Eq. (4). The error location polynomial σ(x) is defined as:
σ( x )=σ 0 +σ 1 x+ . . . +σ t−1 x t−1 +x t . (5)
The key equation to be solved is shown in the following equation:
σ( x ) S ( x )=−ω( x )+μ· x 2t , (6)
where the error value polynomial ω(x) is defined as:
ω( x )=ω 0 +ω 1 x+ . . . +ω t−1 x t−1 . (7)
When t=1:
According to the PGZ algorithm, Eq. (8) is obtained from Eq. (4).
[ S 2 ] [ σ 0 ] = [ - S 1 ] and σ 0 = S 1 S 2 ( 8 )
Thus, the error location is computed as
σ( x )=σ 0 +x
Then the t=1 key equation could be solved
σ( x ) S ( x )=−ω( x )+μ· x 2 ω( x )=−(σ 0 +x )( S 1 +S 2 x )mod x 2 ,
where the error value polynomial is
ω( x )=ω 0 and ω 0 =σ 0 S 1 (9)
For t=1, the register transistor level (RTL) hardware architecture that uses the foregoing PGZ algorithm to solve Eqs. (8) and (9) is shown in FIG. 4 , including:
FFA×1; FFM×2; FFI×1
When t=2:
According to the PGZ algorithm, Eq. (10) is obtained from Eq. (4)
[ S 2 S 3 S 3 S 4 ] [ σ 1 σ 0 ] = [ - S 1 - S 2 ] ⇒ σ 0 = S 1 S 3 + ( S 2 ) 2 S 2 S 4 + ( S 3 ) 2 , σ 1 = S 2 S 3 + S 1 S 4 S 2 S 4 + ( S 3 ) 2 . ( 10 )
The error value polynomial for solving the t=2 key equation is:
ω( x )=ω 0 +ω 1 x and ω 0 =σ 0 S 1 , ω 1 =σ 0 S 2 +σ 1 S 1 (11)
For t=2, the RTL hardware architecture using the PGZ algorithm to solve Eqs. (10) and (11) is shown in FIG. 5 , which includes:
FFA×4; FFM×1; FFI×1
When t=3:
According to the PGZ algorithm, Eq. (12) is obtained from Eq. (4):
[
S
2
S
3
S
4
S
3
S
4
S
5
S
4
S
5
S
6
]
[
σ
2
σ
1
σ
0
]
=
[
-
S
1
-
S
2
-
S
3
]
⇒
σ
0
=
S
2
S
3
S
4
+
S
2
S
3
S
4
+
S
1
S
3
S
5
+
S
1
S
4
S
4
+
S
2
S
2
S
5
+
S
3
S
3
S
3
S
2
S
4
S
6
+
S
3
S
4
S
5
+
S
3
S
4
S
5
+
S
4
S
4
S
4
+
S
3
S
3
S
6
+
S
2
S
5
S
5
σ
1
=
S
2
S
2
S
6
+
S
1
S
4
S
5
+
S
3
S
3
S
4
+
S
2
S
4
S
4
+
S
1
S
3
S
6
+
S
2
S
3
S
5
S
2
S
4
S
6
+
S
3
S
4
S
5
+
S
3
S
4
S
5
+
S
4
S
4
S
4
+
S
3
S
3
S
6
+
S
2
S
5
S
5
σ
2
=
S
1
S
4
S
6
+
S
2
S
4
S
5
+
S
3
S
3
S
5
+
S
1
S
5
S
5
+
S
2
S
3
S
6
+
S
3
S
4
S
4
S
2
S
4
S
6
+
S
3
S
4
S
5
+
S
3
S
4
S
5
+
S
4
S
4
S
4
+
S
3
S
3
S
6
+
S
2
S
5
S
5
(
12
)
The error value polynomial for solving the t=3 key equation is:
ω( x )=ω 0 +ω 1 x+ω 2 x 2 and ω 0 =σ 0 S 1 , ω 1 =σ 0 S 2 +σ 1 S 1 , ω 2 =σ 0 S 3 +σ 1 S 2 +σ 2 S 1 (13)
For t=3, the RTL hardware architecture using the PGZ algorithm to solve Eqs. (12) and (13) includes:
FFA×19; FFM×49; FFI×1
Therefore, the Reed-Solomon decoder based upon the conventional PGZ algorithm requires a larger area in an IC and has a low hardware resource utilization. Furthermore, the implementation of the algorithm requires the FFI operations, which complicates the circuit design and deteriorates the calculation speed. The invention simplifies the algorithm so that the disclosed Reed-Solomon is less complicated in calculations. Furthermore, it requires no FFI operations when solving key equations. This can effectively reduce die size while increasing the calculation efficiency.
The Reed-Solomon decoding procedure further simplifies Eq. (12) in the t=3 PGZ algorithm according to the present invention. For the denominators of σ 0 , σ 1 , σ 2 , two terms of S 3 S 4 S 5 are cancelled in FFA. Analogously, the numerator of σ 0 has two terms of S 2 S 3 S 4 that can be cancelled in FFA. In addition, the product terms S 2 S 2 S 5 , S 2 S 3 S 5 , S 2 S 4 S 5 , S 2 S 5 S 5 of σ 0 , σ 1 , σ 2 in Eq. (12) have a common term S 2 S 5 . Therefore, the disclosed solving procedure first computes the value of S 2 S 5 to reduce the calculation complexity. Other common terms S 2 S 6 , S 4 S 4 , S 3 S 3 , S 1 S 5 , and S 1 S 6 can be similarly computed, too. In this manner, the RTL hardware architecture of Eqs. (12) and (13) solved using the PGZ algorithm for t=3 can be simplified ( FIG. 6 ) to include:
FFA×12; FFM×27; FFI×1
Moreover, the solving process of the PGZ algorithm involves FFI operation. This does not only lower the computing speed of the hardware but also occupy die size area. Thus, the invention further simplifies the PGZ algorithm so as to reduce FFI operation 106 .
With reference to Eq. (4), we further define the syndrome matrix S t×t , the error location vector σ t×1 , and the syndrome vector s t×1 as follows:
S
t
×
t
=
[
S
2
S
3
…
S
t
+
1
S
3
S
4
…
S
t
+
2
⋮
⋮
⋰
⋮
S
t
+
1
S
t
+
2
…
S
2
t
]
,
σ
t
×
1
=
[
σ
t
-
1
σ
t
-
2
⋮
σ
0
]
,
s
t
×
1
=
[
-
S
1
-
S
2
⋮
-
S
i
]
Therefore, the Newton Identity can be expressed as
S t×t σ t×1 =s t×1 , (14)
and the determinant of the syndrome matrix S t×t is denoted by
A t =det( S t×t ). (15)
When multiplying the determinant A t by Eqs. (5) and (7), a new error location polynomial Φ(x) and a new error value polynomial Ω(x) are obtained. They can be expressed as:
Φ( x )= A t σ( x )= A t σ 0 +A t σ 1 x+ . . . +A t σ t−1 x t−1 +A t x t
Φ( x )=Φ 0 +Φ 1 x+ . . . +Φ t−1 x t−1 +Φ t x t (16)
Ω( x )= A t ω( x )= A t ω 0 +A t ω 1 x+ . . . +A t ω t−1 x t−1
Ω( x )=Ω 0 +Ω 1 x+ . . . +Ω t−1 x t−1 (17)
When t=1:
A 1 =S 2 ; (18)
Φ 0 =A 1 σ 0 , Φ 1 =A 1 ; (19)
Ω 0 =A 1 σ 0 S 1 =A 1 ω 0 . (20)
When t=2:
A 2 =S 2 S 4 +( S 3 ) 2 ; (21)
Φ 0 =A 2 σ 0 , Φ 1 =A 2 σ 1 , Φ 2 =A 2 ; (22)
Ω 0 =A 2 σ 0 S 1 =A 2 ω 0 Ω 1 =A 2 σ 0 S 2 +A 2 σ 1 S 1 =A 2 ω 1 . (23)
When t=3:
A 3 =S 2 S 4 S 6 +S 3 S 4 S 5 +S 3 S 4 S 5 +S 4 S 4 S 4 +S 3 S 3 S 6 +S 2 S 5 S 5 ; (24)
Φ 0 =A 3 σ 0 , Φ 1 =A 3 σ 1 , Φ 2 =A 3 σ 2 Φ 3 =A 3 ; (25)
Ω 0 =A 3 σ 0 S 1 =A 3 ω 0 , Ω 1 =A 3 σ 0 S 2 +A 3 σ 1 S 1 =A 3 ω 1 ;
Ω 2 =A 3 σ 0 S 3 +A 3 σ 1 S 2 +A 3 σ 2 S 1 =A 3 ω 2 . (26)
In comparison with the conventional PGZ algorithm for computing σ for t=3, the invention greatly simplifies the PGZ algorithm so that the FFI operation is not needed when computing Φ for t=3. The RTL hardware of the simplified PGZ algorithm that does not need FFI operations for t=3 is shown in FIG. 7 , which only requires:
FFA×12; FFM×24; FFI×0
However, the conventional PGZ architecture utilizes the redundant hardware circuits to achieve different error-correcting abilities (t≦3), as shown in FIG. 2 . An objective of the invention is to use a single hardware circuit to achieve all theses error-correcting abilities (t=0,1,2,3), as shown in FIG. 3 .
Furthermore, for the conventional PGZ algorithm, the PGZ decoding circuit for t=3 cannot correctly solve the t=1, 2 error(s). This is because when t is less than 3, divided-by-zero problems occur. For t=3, the equation to be solved is:
[
S
2
S
3
S
4
S
3
S
4
S
5
S
4
S
5
S
6
]
[
σ
2
σ
1
σ
0
]
=
[
-
S
1
-
S
2
-
S
3
]
.
(
27
)
If the number of error is less than 3, the rows or columns in the matrix S 3×3 will be linearly dependent; that is
[ S 2 S 3 S 4 ] = α [ S 3 S 4 S 5 ] = β [ S 4 S 5 S 6 ] ,
where α and β are constants.
Accordingly, the denominator and the three numerators in Eq. (12) will be 0. In other words,
S 2 S 4 S 6 +S 4 S 4 S 4 +S 3 S 3 S 6 +S 2 S 5 S 5 =0
S 1 S 3 S 5 +S 1 S 4 S 4 +S 2 S 2 S 5 +S 3 S 3 S 3 =0
S 2 S 2 S 6 +S 1 S 4 S 5 +S 3 S 3 S 4 +S 2 S 4 S 4 +S 1 S 3 S 6 +S 2 S 3 S 5 =0
S 1 S 4 S 6 +S 2 S 4 S 5 +S 3 S 3 S 5 +S 1 S 5 S 5 +S 2 S 3 S 6 +S 3 S 4 S 4 =0 (28)
Similarly, if the number of errors is less than 2, the two sets of denominators and numerators in Eq. (10) will be 0 too. That is,
S 2 S 4 +S 3 S 3 =0
S 1 S 3 +S 2 S 2 =0
S 1 S 4 +S 2 S 3 =0 (29)
Once divided-by-zero problems occur when computing σ, the conventional PGZ algorithm cannot perform error corrections. To solve this problem, the prior art requires the use of the redundant duplicate hardware circuits, as shown in FIG. 2 . A state machine that checks error states is employed to correct different numbers of errors.
In order to correct different numbers of errors using a single hardware circuit, the invention extracts important information from Eqs. (28) and (29). Such information can be used to find out the number of errors. Explicitly,
when t=0: S 2 =0; when t=0,1: S 2 S 4 +S 3 S 3 =0; when t=0,1,2: S 2 S 4 S 6 +S 4 S 4 S 4 +S 3 S 3 S 6 +S 2 S 5 S 5 =0
From Eq. (15), the following expressions are obtained:
A 1 =S 2 ;
A 2 =S 2 S 4 +S 3 S 3 ;
A 3 =S 2 S 4 S 6 +S 4 S 4 S 4 +S 3 S 3 S 6 +S 2 S 5 S 5 .
Therefore, using A 1 , A 2 , and A 3 can determine the number of errors. Multi-mode decoding procedure based on the simplified PGZ algorithm is shown in FIG. 8 .
The simplified t=3 PGZ algorithm shown in FIG. 7 implements the RTL hardware without FFI operations. A controller 107 is capable of obtaining the number of errors as shown in FIG. 8 . The multi-mode PGZ decoder 100 accomplishes the goal of using one circuit to solve different errors (t≦3). FIG. 9 shows an RTL hardware embodiment of the multi-mode PGZ decoder 100 according to the present invention, which includes:
FFA×15; FFM×27; FFI×0
Based upon the simplified PGZ algorithm, the Reed-Solomon decoding procedure according to the present invention comprises the steps of: computing the syndrome of received data; solving a key equation; and evaluating error locations and error value, wherein the step for solving the key equation is based upon the simplified PGZ algorithm. For t=3 PGZ algorithm, one first computes the common term of σ(x) in the error location polynomial (12) to reduce the number of the required FFA and FFM. Then perform a solving procedure without requiring FFI operations. This greatly reduces the calculation complexity and the occupied die area. In the invention, a multi-mode decoding method uses the determinant A t to determine the number of errors for implementing the multi-mode Reed-Solomon decoding procedure.
In another embodiment of the invention, the multi-mode Reed-Solomon decoder comprising: a syndrome calculator 101 to calculate syndromes of received data; a key equation solver 102 to receive a syndrome equation output from the syndrome calculator 101 ; and an error location and error value evaluator 103 to obtain the error locations and error value. The key equation solver uses a simplified PGZ decoder as the basis thereof. The improved PGZ decoder comprises FFA 104 and FFM 105 without requiring any FFI 106 . The PGZ decoder contains a multi-mode decoding controller 107 , which determines the number or errors from the determinant value A t so that the improved PGZ decoder can simultaneously perform t=0,1,2,3 error corrections. Thus, the invention discloses a multi-mode PGZ decoder 100 to implement the key equation solver 102 .
Effects of the Invention
In accordance with the invention, the multi-mode Reed-Solomon decoder and method are based upon a simplified PGZ algorithm to solve key equations. The key equation solver is a multi-mode PGZ decoder that includes FFA and FFM without the need of any FFI. The multi-mode PGZ decoder further comprises a multi-mode decoding controller, which determines the number of errors using the determinant value A t , so that the improved PGZ decoder can perform error corrections with t=0,1,2,3. Therefore, the disclosed Reed-Solomon decoder lowers the cost and reduces the die size. The simplified PGZ algorithm also greatly reduces the calculation complexity, to enhance the operation speed of the key equation solver.
While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | A multi-mode Reed-Solomon decoder is disclosed. According to the invention, by simplifying the Peterson-Gorenstein-Zierler (PGZ) algorithm the goal of correcting different numbers of errors (t≦3) using a single hardware architecture is achieved. Through optimization without requiring finite field inversion operations, the hardware and the computing efficiency are both improved. The invention also discloses a register transistor level (RTL) hardware architecture to applied in error control codes (ECC) between a processor and a memory and other high-speed communication systems. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of and claims the benefit of U.S. patent application Ser. No. 10/396,619, filed Mar. 25, 2003, now U.S. Pat. No. 7,044,684, entitled “PLOW BLADE WITH WATER PASSAGEWAY.”
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
Many types of services are delivered to homes through conduits installed in relatively shallow underground trenches. These include telephone, television, natural gas, electricity, and drainage. These utilities are often installed with a plow. FIG. 1 illustrates an example installation of a utility 20 with a prior art plowing process. A plow 30 is attached to a prime mover, typically a tractor 10 . The tractor 10 propels the plow through the ground. The plow 10 is relatively narrow and will split the ground open with a sharpened steel blade. The utility line 20 is introduced into the ground through a chute 40 that is attached to and directly behind the blade. The chute 40 holds the ground open as the utility line 20 is being fed into the desired vertical position and places the utility line 20 into a horizontal position at the desired depth under ground.
An alternate configuration is illustrated in FIG. 2 where the utility line 20 is laid out on the ground behind its intended position and then the plow 30 is connected to one end. The plow is then pulled through the ground in order to pull the utility line 20 into the correct position. In this configuration there is no chute.
Depending on the desired depth, size of utility line, and the ground (soil) conditions (clay, sand, loam, etc.). This process may be slow and require a large amount of power from the tractor 10 to pull the blade/chute through the ground. To reduce this loading various efforts have been made to inject liquid to the plow and to the utility being installed to wet the ground.
In some past designs the liquid was water, ejected in the direction of travel of the plow blade, and at the edge of the plow blade, utilizing the water to assist in the cutting action required to slice the ground.
In other designs, useful for applications as illustrated in FIG. 2 , the liquid has been water directed to the area around the utility line being pulled through the ground to lubricate and reduce the frictional drag.
In still other designs water has been directed through long holes 36 drilled into the blade 34 of the plow 30 . Additional cross-drilled holes threaded to accept cooperating nozzles 38 are drilled near front edge 32 , as illustrated in FIGS. 3 and 4 . Water was then pumped into inlet fitting 37 to route water to the sides of the plow. This design has proven successful as the lubrication provided by the water significantly reduces the power necessary to pull the plow. However this requires complicated manufacturing processes, with the result that a wear item, the blade, becomes a relatively expensive component. There exists a need for a blade to provide this water distribution in a manner that is less expensive to initially manufacture and to maintain.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a novel design for a plow blade which provides a fluid passage and points of fluid ejection which is produced with basic manufacturing processes allowing efficient production.
Another aspect of the present invention is a blade construction including a multiple component assembly. This provides the ability to rebuild a blade, replacing a portion of the blade that may be worn.
In another aspect of the present invention a process of ejecting a specific fluid at specific points along a plow blade the desirable characteristics are maximized, while the volume of ejected fluid is minimized. This method is adaptable in static plowing and vibratory plowing utilities. Lubricating the sides of the blade/chute that come into contact with the ground with fluid has been found to greatly reduce the amount of drag (friction).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a prior art tractor propelling a plow through the ground and installing a utility line that is being ejected through a chute attached to the plow;
FIG. 2 is a side view of a prior art tractor propelling a plow through the ground and installing a utility that is being pulled through the ground and attached to the plow;
FIG. 3 is side view of a prior art plow;
FIG. 4 is cross section of the prior art plow taken along line 4 - 4 as illustrated in FIG. 3 ;
FIG. 5 is a side view of one embodiment of a plow constructed in a manner of the present invention;
FIG. 6 is an isometric view of a portion of another embodiment of the plow of the present invention;
FIG. 7 is a cross-section taken along plane 7 - 7 as illustrated in FIG. 6 ;
FIG. 8 is an isometric view of a front edge section;
FIG. 9 is an isometric view of a portion of still another embodiment of the plow of the present invention;
FIG. 10 is a cross-section taken along plane 10 - 10 as illustrated in FIG. 9 ;
FIG. 11 is a side view of another preferred embodiment of a plow constructed in a manner of the present invention;
FIG. 11A is an enlarged view of the part marked 11 A in FIG. 11 ;
FIG. 12 is a cross-section taken along plane 12 - 12 as illustrated in FIG. 11 ;
FIG. 13 is cross-section taken along plane 13 - 13 as illustrated in FIG. 11 ;
FIG. 14 is a partial cross-section taken along plane 13 - 13 as illustrated in FIG. 11 : and
FIG. 15 is a view like FIG. 7 but showing an alternate embodiment with the void or channel formed in the blade instead of in the back of the front edge section.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, like reference numerals designate identical or corresponding parts throughout the several views. The included drawings reflect the current preferred and alternate embodiments. There are many additional embodiments that may utilize the present invention. The drawings are not meant to include all such possible embodiments.
FIG. 5 illustrates a plow 100 constructed according to the principles of the present invention. Plow 100 consists of blade 110 , leading edge sections 120 , point 130 and a fluid tube 140 . Chute 40 is attached to the rear edge 114 of blade 110 , and is constructed to receive and guide utility line 20 from above the ground to the desired depth where it is oriented generally parallel to the ground surface. In other embodiments, the chute may be replaced by a puller adapted to hold a utility line that is being pulled through the ground, similar to the arrangement shown in FIG. 2 .
The blade 110 further includes a front edge 112 , a top end 116 and a bottom end 118 . The top end 116 includes apertures 117 which will serve as attachment points, to adapt to a power unit. Many different types of power units can be used in conjunction with the preset invention.
The bottom end 118 is adapted to support a variety of points 130 . The type of point to be installed may be dependent upon the soil conditions of a particular job.
A component of the present invention is the manner in which the components are assembled to form flow paths for fluid to exit the blade at controlled locations and with a controlled flow rate. The flow paths of this first embodiment illustrated in FIG. 5 are defined when the front edge 120 is attached to the blade 110 . FIG. 8 illustrates a void 124 in surface 122 of leading edge section 120 . Fluid tube 140 is adapted to travel in void 124 to transfer pressurized fluid from the top of plow 100 into the void 124 , and may be sealed with weld 152 illustrated in FIG. 6 . Other forms of sealing the connection between the tube 140 and the front edge sections 120 are possible, but are not illustrated herein as they are not a critical element of the present invention. Tube 140 has a top end 144 and a bottom end 146 and may extend into void 124 for any desired distance, as will be explained later.
As illustrated in FIGS. 6 and 7 the leading edge sections are attached to blade 110 with stitch welds 150 . Flow paths are defined by providing a small gap 154 between the front surface 112 of the blade and the rear surface 122 . The spaces between the stitch welds 150 results a flow path for the pressurized fluid, allowing fluid to pass from the void 124 , through the gap 154 between surfaces 122 and 112 , and out between the stitch welds 150 . In this manner, the location and length of the stitch welds 150 defines the location at which the fluid will exit the blade 110 . The gap 154 ( FIG. 7 ) between the Surfaces 112 and 122 combined with the total amount of weld gap will define the volume at which the fluid will be ejected from the blade 110 at a certain fluid pressure.
FIG. 15 shows an alternate arrangement of the FIG. 7 structure, having the void or groove 224 formed in the front of the blade instead of having the void or groove 124 formed in the back of the leading edge section as shown in FIG. 7 .
The fluid pressure at a certain point along the blade's length will vary. If the tube 140 terminates at the top of blade 110 , the fluid pressure will be highest at that point and will decrease at points closer to the bottom. This is not ideal as there tends to be more resistance from the soils near the bottom of the blade, which requires the highest fluid pressure near that area. This is due to the types of soils typically encountered at lower depths. The surface soils typically include some percentage of organic matter, and higher percentage of air pockets: it is typically less dense. The soils encountered at points deeper can include the more difficult soils including clay. Thus there is an area, illustrated in FIG. 5 , as a critical high friction area. This is the area in which the fluid is most critical. In order to assure that the fluid is ejected most aggressively in this area tube 140 can be extended so that it terminates at a position towards the bottom of this critical high friction area, the tube end 146 is located near the bottom end 118 of the blade 110 . The fluid pressure in void 124 will be highest at the point the tube terminates. In this manner the volume of fluid at this point can be maximized.
In addition to varying the length of tube 140 , the number of leading edge sections 120 that are welded onto blade 110 can be varied to match the requirements of a specific job, including specific installation depths. The number of and location of the stitch welds can also be adjusted to tailor a plow 100 for a specific application. In this manner it is possible to provide a nearly infinite variety of configurations in an economic manner.
Another embodiment is illustrated in FIGS. 9 and 10 . In this configuration a manifold 160 is installed in between the blade 110 and the leading edge sections 120 . The manifold includes drilled holes 166 extending from a front side 164 to a rear side 162 , as illustrated in FIG. 10 . The drilled holes 166 intersect at the middle, and when the leading edges 120 are installed onto the front side 164 the drilled holes 166 will terminate at the void 124 in the leading edge 120 . In this manner a flow path is defined by the void 124 and the holes 166 which will allow fluid to be routed from tube 140 to nozzles 168 that are installed at the rear side 162 of the manifold 160 .
In this embodiment varying the nozzles 168 utilized in the assembly allows control of the flow rates and location of the fluid injection. The nozzles 168 can be replaced by plugs (not shown) if there are areas where fluid is not required, and the size of the nozzles 168 can be varied if the there are areas where extra flow is required. It provides a plow that can be modified using hand tools, without welding.
Still another preferred embodiment is illustrated in FIGS. 11 , 11 A, 12 and 13 . In this embodiment the fluid tube 140 has been located on the opposite side of blade 110 , the rear side 114 . As can be seen in FIG. 12 the fluid tube is located between the blade 110 and the chute 40 . In this configuration it is protected by plates 42 . The fluid tube includes an inlet fitting 142 at the top and travels to the bottom end 118 of blade 110 where it terminates at tube end 146 . The cross hatched portion shown in FIG. 11A represents a weld.
Tube end 146 is adapted to attach to a bottom end section 126 , as illustrated in FIG. 13 . Bottom end section 126 includes void 128 in the top side 127 as illustrated in FIG. 14 . Tube 140 includes a bend that allows it to enter into void. The tube 140 is then sealed by welding it to the bottom end section 126 and the blade 110 with weld 156 such that the fluid is forced into void 128 . The bottom end section 126 is also welded to the blade 110 at the locations where it contacts the blade 110 , thus sealing the void 128 .
Void 128 intersects void 124 at the bottom-front corner of blade 110 . At this point the fluid is transferred to void 124 and will flow along the front edge 112 of blade 110 . As described for the previous two embodiments, the fluid can then be allowed to travel to the edge of the blade and out to the soil either through a gap and spaces between stitch welds 150 , or through a manifold 160 between the front edge sections 120 and the blade 110 . FIGS. 11 and 12 illustrate the use of the stitch welds 150 and gaps 151 between stitch welds 150 . However, the manifold 160 would work equally well.
All the previously described embodiments provide a plow that can be tailored to provide fluid injection characteristics to match specific job requirements. The components are all manufactured with traditional manufacturing processes. The flow paths are defined by stacking together leading edge sections with flow voids, and welding or otherwise attaching them to a blade. This configuration provides appropriate function and provides an easily tailored configuration.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A plow blade having a fluid passageway and points of fluid ejection is produced with basic manufacturing processes allowing for efficient production. The blade construction has a multiple component assembly for providing the ability to rebuild a blade and replacing a portion of the blade that may be worn. In another aspect of the invention a process of ejecting a specific fluid at specific points along a plow blade the desirable characteristics are maximized, while the volume of ejected fluid is minimized. This method is adaptable in static plowing and vibratory plowing utilities since lubricating the sides of the blade/chute that come into contact with the ground with fluid has been found to greatly reduce the amount of drag (friction). | 4 |
FIELD OF INVENTION
[0001] The present invention relates generally to photovoltaic and Light emitted diode device manufacturing, using micro and nano-scale structure layers, depositing Quantum Dots onto the micro-nanostructures and using nonradiative energy transfer for energy conversion.
BACKGROUND OF PRIOR ART
[0002] Photovoltaic is the field of technology, which directly converts sunlight to electricity. The solar cell is the elementary building block of the photovoltaic (PV) technology. Solar cells are made of semiconductor materials, such as silicon. One of the properties of the semiconductors that makes them most useful is that their conductivity may easily be modified by introducing impurities into their crystal lattice. On one side of the cell the impurities, which are phosphorus atoms with five valence electrons, on the other side, atoms of boron with three valence electrons create a greater affinity than silicon to attract electrons.
[0003] The layers of the photovoltaic cells made of semiconductor materials, which should be light responsive. The materials include Group I-III-VI, Group IV and Group III-V, as well as II-VI semiconductor materials, such as CdTe, CdSe, CdS, CdO, ZnS, and so on.
[0004] Chanyawadee, S. et al, fabricate a hybrid nanocrystal quantum-dot patterned p-i-n structure that utilizes nonradioactive energy transfer from highly absorbing colloidal nanocrystal quantum dots to a patterned semiconductor slab to demonstrate a six fold increase of the photocurrent conversion efficiency compared to the bare p-i-n semiconductor device. The heterostructure was grown by molecular beam epitaxy on a (100) GaAs substrate in a p-i-n configuration that consists of 20 periods of 7.5 nm thick GaAs quantum wells with 12 nm thick AlGaAs barriers, (Physical Review Letters, 102, 077402, 2009.
[0005] In another article by Chanyawadee, S. et al, (Applied Physics Letters, 94, 233502, 2009), demonstrate photocurrent enhancement of a hybrid PV device consisting of highly absorbing colloidal Nanocrystals (NC) and a patterned bulk p-i-n heterostructure at both low 25 K and room temperature. The patterning is designed to bring the colloidal NCs into close proximity with the intrinsic region of the p-i-n heterostructure so that the excitation energy of the deposited NCs is efficiently transferred to the patterned bulk p-i-n heterostructure by means of nonradiative energy transfer. This hybrid NC/bulk p-i-n device offers about two orders of magnitude higher photocurrent than the hybrid NC/Quantum Well p-i-n PV device from their previous work above and releases the potential of high efficiency PV cells and optoelectronic devices.
[0006] Kiravittaya, S. et al, proposes Quantum Dots (QD) using InGaAs on InAs of size 40-50 nm in diameter and 4-7 nm in height to be used for PV applications because of its wider spectral response, better temperature stability and possibility of carrier storage feature, (PV Conference 2000, 28 th IEEE Conf., P 818-821, 2000).
[0007] Patent application (WO 2008/137995) discloses an improved photovoltaic devices and methods. A photovoltaic device includes a semiconductor layer and a light-responsive layer which form a junction, such as a p-n junction. The light-responsive layer can include a plurality of carbon nanostructures, such as carbon nanotubes, located therein. In many cases, the carbon nanostructures can provide a conductive pathway within the light-responsive layer. In other photovoltaic devices include semiconductor nanostructures, which can take a variety of forms, in addition to the carbon nanostructures. Methods of fabricating photovoltaic devices are also disclosed.
[0008] Another Patent application US 2008/0216894 A1 suggests Nanostructures and quantum dots are used in photovoltaic cells or solar cells outside of the active layer to improve efficiency and other solar cell properties. In particular, organic photovoltaic cells can benefit. The quantum dot layer can be found between the light source and the active layer or on the side of the active layer opposite the light source. Quantum dots can also be used in electrode layers.
[0009] A prior art suggests several QD layers to be deposited in the active layer of the solar cell having several bandgaps and Fermi levels. Particularly, the size and composition of a QD can determine its bandgap and Fermi level, (US 2009/0255580 A1).
[0010] Patent application (US 2008/0130120 A1) suggests nanostructured layers absorbing IR and/or UV in a photovoltaic device increases efficiency of solar cells. The nanostructure materials are integrated with one or more of: crystalline silicon (single crystal or ponlycrystalline) solar cells and thin film (amorphous silicon, microcrystalline silicon, CdTe, CIGS and III-V materials) solar cells whose absorption is primarily in the visible region. The nanoparticle materials are comprised of quantum dots, rods or multipods of various sizes.
DETAILED DESCRIPTION
[0011] An electrode system comprising anode and cathode, and photovoltaic device comprise an active layer, where light energy is absorbed and converted to electrical energy, as well as, if needed a mechanical support system like a substrate and other optional layers like hole injection layers, hole transport layers, additional substrates, reflective layers, encapsulants, barriers, adhesives, and the like. The photovoltaic device can comprise organic active layer components, or can be a hybrid.
[0012] The quantum dot layer comprises one or more nanoparticle. The quantum dots in the layer can be the same material or can be mixtures of different materials including two or more materials. For example, the quantum dot layer can comprise of three different quantum dot materials or more. The different dots function together to produce a desired result. The quantum dots in the layer can be the same size or can be mixture of various sizes. Different particles can be combined to provide mixtures. Particle sizes and particle size distributions provide the desired fluorescent properties of light absorption and light emission, functioning together with the light absorption of the active layer. Particle size can be based on a variety of quantum dot. The optical absorption and emission can be shifted to the blue with decreasing particle size. Quantum dots can exhibit broad absorption of high-energy or blue, and UV light energy, and narrower emission to the red of the wavelength of absorption.
[0013] The incident radiation upon the quantum dot layer is red-shifted to form red-shifted radiation, and an active layer which absorbs red-shifted radiation. Red-shifting by quantum dots is known. Nanostructures are generally known in the art, and quantum dots are also generally known in the art and can be distinguished from quantum wells and quantum wires. Nanostructures can comprise nanoparticle. Nanostructures can exhibit fluorescent properties and comprise fluorophores.
[0014] The quantum dots can be inorganic materials, metallic materials, and can be semiconductor materials including, and not limited to, for example elements from Group II, Group III, Group IV, Group V, or Group VI including II-VI and III-V materials. Examples include CdS, CdSe, CdTe, InP, InAs, ZnS, ZnSe, HgTe, GaN, GaP, GaAs, GaSb, InSb, Si, Ge, AlAs, AlSb, PbSe, PbS, and PbTe. Further example, InGaAs and InGaN, AlInGaP. In particular, quantum dots which absorb the UV and blue light range emit in the visible or near infrared, and particularly, CdS and CdSe can be used.
[0015] The layer comprising quantum dots can absorb radiation of a first wavelength range and may exhibit a peak or maximum absorption, in some limited cases, as well as peaks on shoulders, overlapping peaks, and cutoff wavelengths. Wavelength ranges for absorption can be determined by methods known in the art. The first wavelength range can include absorption bands consistent with efficient solar energy collection and conversion to electric power. The quantum dot layer can have an absorption peak at about 250 nm to about 2800 nm. The range of desired absorption wavelengths and peaks in any given device may span on any range within the above limits.
[0016] The quantum dots layer in general can be adapted to absorb light which is not absorbed by the active layer. For example, the active layer may absorb light in the red or near infrared and the quantum dot layer can absorb at shorter and higher energy or wavelengths. The quantum dot layer can then reemit radiation in the abruption spectra for the active layer. The maximum emission wavelength of the quantum dot can be chosen to overlap with the maximum absorption wavelength of the active layer.
[0017] Quantum dots can be used in colloidal forms using wet chemical methods including with carrier solvents. Homogeneous nucleation in a fluid solvent can be carried out. Alternatively, quantum dots can be formed by making a thin film (e.g., by molecular beam epitaxy (MBE) or chemical vapor deposition (CVD)) and heating to convert the film to dot form, or alternatively by nanolithography. Many existing techniques face difficulties with exciton recombination, charge transport, and limited device efficiency. The present invention is directed to a nanostructure layers and quantum dot on an epitaxial wafer having greater efficiency.
[0018] In the present invention, quantum dots are used onto a very thin nanostructure layer near the active material in the photovoltaic cell for harvesting more light to convert photons into charge carriers. Quantum dots have many desirable physical properties in photovoltaics, such as a tunable bandgap and Fermi level. A quantum dot's bandgap can be much different from the bulk material due to the small size of the quantum dot. In general, the bandgap of a quantum dot is inversely related to the quantum dot size, thereby quantum dots can be tuned to have the desired bandgaps.
[0019] It is important to note that the size of a quantum dot also determines its Fermi level. Similar to the bandgap, the location of the Fermi level of a quantum dot is inversely related to the quantum dot size; quantum dots of smaller sizes generally have higher Fermi levels than larger quantum dots of the same composition.
[0020] The photovoltaic device includes QD deposited on the first nanostructure layer, a first conductor layer, a second conductor layer, an active layer and a second nanostructure layer. The first and second conducting layers can be any material suitable for conducting charges (e.g. electrons, holes, or any other charge carriers). In operation, a photon is absorbed in the active layer and dissociates at least one excite, thereby creating pairs of charge carriers. The charge carriers are transported to the first and second conductor layers. The first conductor layer and the first nanostructure layer allowing the photon to pass through it and be absorbed in the active layer. Additionally, the second conductor layer can be optically reflective to increase the probability that the photon will interact with the active layer.
[0021] Methods utilized for growing high quality flat and thick compound semiconductors onto foreign substrates using nanostructure compliant layers. These methods uses structures of substantially constant diameter along the majority of their length like nanorods, or other structures that vary in diameter along their dimensions like pyramids, cones or spheroids. Nanorods of semiconductor materials can be grown on any foreign substrates by molecular beam epitaxy (MBE), chemical vapor deposition (CVD), metalorganic chemical vapor deposition (MOCVD), metalorganic vapor phase epitaxy (MOVPE) or hydride-vapor phase epitaxy (HVPE) methods. Such nanorods may typically have a diameter of about 10 to 120 nm. Further growth of continuous compound semiconductor thick films or wafer can be achieved by epitaxial lateral overgrowth. The topography of nanorods with a narrow air gap permits coalescence with a very thin overgrown layer. Typically only 0.2 μm thicknesses are required for continuous overgrown layer. For example, the use of GaN nanorods as the compliant layer to grow thick GaN has several advantages. The stress and dislocations are mostly localized in the interface between the GaN nanorods and the substrate. Thus growth leads to the top part of the GaN nanorods being nearly free of stress and dislocations. A high-quality thick GaN can therefore be grown on this nanorods compliant layer, and has very little tilting in the coalesced front either on top of the nanorods or on top of the air gap. A protection area on the wafer's edge has been introduced to reduce the overall stress of the surface in the process of the fabrication of epitaxial growth wafer, and that is the epitaxial growth will happen only on the nanostructured area of the wafer producing a stress free epitaxial wafer.
[0022] GaN nanorods with their inbuilt flexibility, due to their aspect ratio and nano-dimensions, will develop minimal internal stress. In order to separate the thick GaN from the substrate with ease and reproducibility, an AlN nucleation layer, under tensile stress, with a critical dimension may be used. Rapid cooling or mechanical twisting will push the local stress to exceed the critical value to separate the thick film. An alternative method of separating the GaN from the substrate is using anodic electrochemical etching. To perform this method, a thin p-GaN layer to be grown on top of the nanorods before the epitaxial lateral overgrowth for thick GaN. A suitable electrolyte and bias voltage results in p-GaN being selectively etched off, to leave the n-GaN untouched.
[0023] The above method is utilized to provide a PV wafer. It is produced by growing an epitaxial initiating growth surface onto a nanostructured substrate, and then grows a semiconductor material, e.g., but not limited to, Si, GaAs, InP onto the nanostructure using epitaxial lateral overgrowth of thickness 20-50 micrometers. Separate the grown semiconductor material from the substrate. Provide a nanostructure onto the semiconductor material using nanoimprint lithography methods.
[0024] The quantum dot composition is selected from the group consisting of PbS, PbSe, PbTe, CdS, CdSe, CdTe, HgTe, HgS, HgSe, ZnS, ZnSe, InAs, InP, GaAs, GaP, AlP, AlAs, Si, and Ge. More generally, the quantum dots can comprise metallic quantum dots, semiconducting quantum dots, or any combination thereof.
[0025] As one of ordinary skill in the art will appreciate, various changes, substitutions, and alterations could be made or otherwise implemented without departing from the principles of the present invention, e.g. other materials not listed herein can be used for the various layers and quantum dots.
SUMMARY OF THE INVENTION
[0026] A photovoltaic device comprising an epitaxial wafer comprises of a plurality of layers, wherein said wafer is epitaxial grown material includes but not limited to InP, InAs, ZnS, ZnSe, GaN, GaP, GaAs, GaSb, InSb, Si, SiC, Ge, AlAs, AlSb, PbSe, PbS, PbTe, InGaAs, InGaN and AlInGaP, wherein the said wafer is epitaxial grown on a nano-structured surface where a space in the outer edge of the surface is protected in order to limit the epitaxial growth on the outer edge, wherein the said wafer is epitaxial grown on a nano-structured surface to thickness 20-100 micrometers, wherein the said epitaxial grown wafer will be separated from the nano-structured surface, a first nanostructure layer with quantum dots, having different compositions and having different sizes, wherein the said nanostructure layers are produced using nanoimprint lithography methods wherein a plurality of said quantum dots deposited onto the said first nanostructure layer which increases the radiation absorption from the incident solar spectrum, a first conductive layer, wherein the said quantum dots can be inorganic materials, metallic materials, and semiconductor materials including, elements from Group II, Group III, Group IV, Group V, or Group VI including II-VI and III-V materials, wherein the materials of the said groups includes but not limited to, CdS, CdSe, CdTe, InP, InAs, ZnS, ZnSe, HgTe, GaN, GaP, GaAs, GaSb, InSb, Si, Ge, AlAs, AlSb, PbSe, PbS, PbTe, InGaAs, InGaN and AlInGaP, an active layer comprises of at least one np-junction, which can be multi-junction, which is situated between the said first and second conductive layers comprises of material exhibiting absorption of radiation, a second conductive layer, and a second nanostructured layer, wherein the said second nanostructure layer situated at the bottom of the photovoltaic cell, which increases the internal reflection inside the substrate and the nanostructure surfaces are structured by a nanoimprint lithography method;
[0027] A light emitting device comprising an epitaxial wafer comprises of a plurality of layers, wherein said wafer is epitaxial grown material includes but not limited to InP, InAs, ZnS, ZnSe, GaN, GaP, GaAs, GaSb, InSb, Si, SiC, Ge, AlAs, AlSb, PbSe, PbS, PbTe, InGaAs, InGaN and AlInGaP, wherein the said wafer is epitaxial grown on a nano-structured surface where a space in the outer edge of the surface is protected in order to limit the epitaxial growth on the outer edge, wherein the said wafer is epitaxial grown on a nano-structured surface to thickness 20-100 micrometers, wherein the said epitaxial grown wafer will be separated from the nano-structured surface, a first nanostructure layer with quantum dots having different compositions and having different sizes, wherein the said nanostructure layers are produced using nanoimprint lithography methods, wherein a plurality of said quantum dots deposited onto the said first nanostructure layer for purpose of non-radiative energy transfer in color-conversion emission, a first conductive layer, wherein the said quantum dots can be inorganic materials, metallic materials, and semiconductor materials including, elements from Group II, Group III, Group IV, Group V, or Group VI including II-VI and III-V materials, wherein the materials of the said groups includes but not limited to, CdS, CdSe, CdTe, InP, InAs, ZnS, ZnSe, HgTe, GaN, GaP, GaAs, GaSb, InSb, Si, Ge, AlAs, AlSb, PbSe, PbS, PbTe, InGaAs, InGaN and AlInGaP, an active layer comprises of at least one np-junction, which can be multi-junction, which is situated between the said first and second conductive layers comprises of material exhibiting excitation of radiation, a second conductive layer, and a second nanostructured layer, wherein the said second nanostructure layer situated at the bottom of the device, which increases the reflection from the backside of the substrate and the nanostructure surfaces are structured by a nanoimprint lithography method.
DESCRIPTION OF THE FIGURES
[0028] FIG. 1 : Structured Silicon Substrate ( 1 ), and a protection area ( 10 ).
[0029] FIG. 2 : Epitaxial Wafer ( 2 ) Grown on top of the Structured Substrate ( 1 ) having a protection area ( 10 ).
[0030] FIG. 3 : The Epitaxial Wafer ( 2 ).
[0031] FIG. 4 : Using NIL for producing Nanostructure layers ( 3 , 4 ) on the top and the bottom of the Epitaxial Wafer ( 2 ).
[0032] FIG. 5 : Finished device comprises of plurality of layers: Protective Glass Layer ( 5 ), First Conductive Layer ( 6 ), First Nanostructure Layer ( 3 ) using NIL and QDs ( 7 ), The Epitaxial Wafer, including n-p Active Layer ( 2 ), Second Nanostructure Layer ( 4 ), Second Conductive Layer ( 8 ), and the light radiation ( 9 ).
[0033] FIG. 6 : Shows surface (silicon substrate) structured only partially ( 62 ) and outer area left unstructured ( 61 ). The epitaxial growth will happen only on the nanostructured area ( 62 ) of the wafer producing a stress free epitaxial wafer. | Photovoltaic and Light emitted diode devices comprise of epitaxial wafer of plurality of layers has been proposed. Quantum Dots are deposited onto the micro-nanostructure layer from the light incident direction to increasing light transmission to the active layer. Quantum dots deposited between the light source and the active layer, on the micro-nanostructure layer, to improve light excitation, since it can absorb wavelengths, which are not absorbed by the active layer, and the size and composition of quantum dots can determine its bandgap. A micro-nanostructured layer at the bottom of the PV wafer, which is produced by Molecular Beam Epitaxy (MBE), increases the internal light reflections in the active layer, which increases the efficiency of light absorption and that leads to a photocurrent enhancement. | 7 |
FIELD OF THE INVENTION
The present invention relates to magnetic field sensing.
BACKGROUND OF THE INVENTION
It has long been known that when an electric current flows in a wire it generates a magnetic field about that wire. The magnetomotive force generated by the current in the wire can be strong enough to reverse the magnetic polarity of a retentive magnetic material placed within the magnetic influence of that magnetomotive force. When the retentive material changes polarity, it induces a voltage pulse in the wire, as well as in a second sense wire if placed within the magnetic influence of the magnetic material. Such a voltage pulse can be used to indicate that the magnetic material has changed polarity. This is the technique used to interrogate the intelligence stored in toroidal ferrite cores used in the memories of digital computers.
When an external magnetomotive force field, as from a magnetic recording tape or the Earth's magnetic field is to be sensed, a magnetically permeable material, whether retentive or not, is brought within that magnetic field. The magnetic field can magnetically saturate the material or at least distort the symmetry of its response to the magnetomotive force generated by an alternating current in an associated drive wire, sometimes called an excitation winding. If the magnetic material saturates, a sense wire or winding associated therewith will note a sharp reduction in the transformer coupling that otherwise exists from the excitation winding, through the magnetic material, and to the sense winding. The excitation winding and the sense winding correspond to the primary and secondary windings, respectively, of a transformer.
When the external magnetic field only distorts the symmetry of the response of the magnetic material, the output voltage from the sense winding contains an increased proportion of even-numbered harmonics of the excitation alternating-current signal impressed on the excitation winding. Saturable reactors, magnetometers, and transformer-like structures of all types have long been known and used for magnetic field sensing.
U.S. Pat. No. 3,521,261 granted on July 21, 1970, to J. L. Metz is one example of such a magnetic sensor. The prior art is filled with physical arrangements of a magnetic material and its primary and secondary windings. Two examples of such prior art are shown in U.S. Pat. Nos. 2,916,696 granted on Dec. 8, 1959, and 3,439,264 granted on Apr. 15, 1969, both to E. O. Schoenstedt. These two patents show a very thin "Permalloy" strip wrapped about one or more conductors and in turn surrounded by a sense winding.
The prior-art magnetic sensing devices are limited since they use intrinsic, quantitative characteristics of the magnetic material, such as coercive force or saturation flux density, to sense the presence or magnitude of a magnetic field. Therefore, these prior-art sensing devices lack absolute accuracy and linearity, in the quantitative sense, in the measurement of a magnetic field or the electric current that develops it.
SUMMARY OF THE INVENTION
In accordance with the present invention, an energizing coil switches a square-loop magnetic material in the presence of a magnetic field, and a sensing coil senses the change of polarity of the magnetic material. The output of the sensing coil is used to sample the amplitude of the driving current. The sampled driving signal current is averaged over time, which results in a voltage level that is a linear representation of the magnitude of the magnetic field being sensed.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by referring to the following detailed description when considered in conjunction with the accompanying drawings wherein like reference numbers refer to the same or similar parts throughout the several views:
FIG. 1 is a simplified drawing depicting a probe including a sensing coil to show how the present invention would be used to test for current in the conductors of a printed circuit pattern;
FIG. 2 is a greatly enlarged, detail drawing of a sensing coil magnet system used in the present invention;
FIG. 3 is a schematic circuit diagram of a system for processing signals in accordance with the present invention in order to determine true magnitude of a magnetic field; and
FIG. 4 (on the same sheet as FIG. 1) is a series of waveforms depicting the operation of the circuit of FIG. 3.
DETAILED DESCRIPTION
Referring now to the accompanying drawings and more particularly to FIG. 1, a printed circuit board 10 is shown generally in isometric view having a conductor 12 formed by printed-wiring techniques on one surface thereof. A pencil-like probe 14 has an electrical insulating tip 16 about 1/32-inch in diameter. The tiny, insulating tip 16 can actually be touched to the printed-wiring conductor 12 without fear of upsetting the operation of the circuit formed on the printed circuit board 10. The tip of the probe 14 contains a sensing coil system behind the insulation 16. In use, the flat insulating tip 16 is preferably placed flat against the conductor 12.
Referring now to FIG. 2, there is shown a simplified schematic diagram of a suitable sensing coil based upon the magnetic-ribbon type of computer memory commonly referred to as a "TWISTER." A Twister memory includes a conductive wire 20 which comprises a single-turn conductive coil. A flat ribbon or tape 22 of retentive magnetic material, preferably Permalloy, is wrapped in a 45° helix around the conductor 20. The Permalloy ribbon 22 is formulated and heat treated according to the prior art to exhibit a square hysteresis loop characteristic such that it switches rapidly from one polarization to the opposite polarization as the applied magnetomotive force reaches and exceeds the coercive force. The ribbon 22 is also treated so as to have a preferred magnetization direction along its length.
A sensing coil 24 is wrapped around the ribbon-wrapped wire 20 such that whenever the Permalloy ribbon 22 switches from one polarity to the other, a momentary voltage pulse is induced in the coil 24.
The structure shown in FIG. 2 is mounted in the end of the probe 14 of FIG. 1 just behind the insulating tip 16. An intermediate segment of the wire 20 is preferably oriented perpendicular to the axis of the body of the probe 14.
Referring now to FIGS. 3 and 4, the wire 20, with the ribbon 22 wrapped around it, is formed with two right-angle bends into the shape illustrated in the upper, left-hand corner of FIG. 3. The Permalloy ribbon 22 is continuous from one end of the wire 20 to the other, even around the right-angle bends. The coil 24 is wrapped about the central portion of the structure comprising the wire 20 and the ribbon 22.
Two prenucleation coils 26 and 28 are wound around the ends of the wire-ribbon structure. One end of each of the coils 26 and 28 is connected directly to its associated end of the wire 20. The coils 26 and 28 are polarized in such a way that when an increasing current flows through the coil 26, the wire 20, and the coil 28, the two portions of the ribbon 22 that underlie the coils 26 and 28 undergo a polarity switch before the one portion of the ribbon that underlies the coil 24 undergoes a polarity switch--all three of the magnetic fields of the ribbon 22 are in aiding magnetic polarization.
The purpose of pre-switching the ends of the ribbon 22 is to eliminate magnetic end effects which can cause a small amount of indecision on the part of the magnetic material as it changes polarity. Indecision is manifest as timing jitter of successive polarity changes. The magnitude of the indecision dictates the responsiveness of the measuring system. More jitter requires averaging over a longer time period to obtain accuracy.
In order to drive the coils 26 and 28 and the wire 20, a ramp oscillator 30 generates ramp-type signals as illustrated in waveform A of FIG. 4. The ramp signals are amplified in an amplifier 32 and delivered to the other end of the coil 26. The other end of the coil 28 is connected via a current-sensing resistor 34 to ground. While ramp signals are preferred, sinusoidal signals, or any other signals without undesirable step changes in current, can be used.
Referring again to waveform A of FIG. 2, as the current increases through the coils 26 and 28 as well as through the wire 20, the Permalloy ribbon 22 switches polarity at its ends inside the coils 26 and 28. As the current through the wire 20 continues to increase, a point is reached at which the Permalloy ribbon 22 within the sensing coil 24 also changes or switches polarity. The polarity change or reversal of the portion of the Permalloy ribbon 22 within the coil 24 generates a voltage pulse in the coil 24, which is illustrated in waveform B of FIG. 4. This voltage pulse is coupled by a step-up transformer 36 to a differential amplifier 38.
The differential amplifier 38 produces two conjugate outputs, one identical to the input pulses of waveform B and one the inverse of the input pulses. The normal or uninverted pulses pass through a current-limiting resistor 40 to a differentiating capacitor-resistor network 42,43. Similarly, the inverted output from the differential amplifier 38 passes through a current-limiting resistor 44 to another differentiating capacitor-resistor network 46,47.
Pulses of negative polarity are dropped across the current-limiting resistor 40 and are shunted to ground by a shunt diode 50. The diode 50 prevents the negative pulses from having any effect on the capacitor 42. However, pulses of a positive polarity as shown in waveform C of FIG. 4 produce a voltage across the resistor 43 of the differentiating capacitor-resistor circuit 42,43 as shown in waveform E of FIG. 4.
Similarly, a positive pulse passing through the current-limiting resistor 44 (see waveform D of FIG. 4) is differentiated by the capacitor-resistor circuit 46,47. Negative pulses passing through the current-limiting resistor 44 are shunted to ground by a diode 54. The differentiated, inverted signal at the junction of the capacitor 46 and the resistor 47 is depicted in waveform F of FIG. 4.
To minimize losses in the pulses depicted in waveforms C and D of FIG. 4, the resistance of each of the resistors 40 and 44 should be low with respect to the values of the resistors 43 and 47.
The two voltage signals depicted in the waveforms E and F and issuing from the two R-C differentiating circuits 42,43 and 46,47 are delivered to an OR-gate 56. The OR-gate 56 ignores the negative portions of the differentiated pulses applied to it. The output of the OR-gate 56 is depicted in waveform G of FIG. 4.
The output of the OR-gate 56 is delivered to the gate terminal of an insulated-gate field-effect transistor 58. Each positive pulse depicted in waveform G of FIG. 4 turns ON the field-effect transistor 58. When a field-effect transistor is in its OFF condition, a very high impedance exists between its controlled terminals--commonly referred to by the polarity-dependent designations "source" and "drain." However, when the field-effect transistor is in the ON condition, a very low impedance exists between its controlled terminals. When a field-effect transistor is ON, it can conduct current in either direction between its controlled electrodes.
The voltage appearing across the current-sensing resistor 34 is proportional to the current flowing through the wire 20 at any given instant. When the field-effect transistor 58 turns ON, it conducts current in either direction between the ungrounded end 60 of the current-sensing resistor 34 and a capacitor 62 of an averaging circuit or low-pass filter comprised of a resistor 64 and a capacitor 66. The ON duration of the field effect transistor 58 is determined by the R-C time constants of the capacitors 42 and 46 with their associated resistors 43 and 47. This ON duration is sufficiently long to allow the capacitor 62 to charge to the voltage present across the current-sensing resistor 34. An example of a typical voltage pattern across the capacitor 62 is depicted in waveform H of FIG. 4. The voltage across the capacitor 62 is filtered through a relatively long time constant of the resistor 64 and the capacitor 66.
The purpose of the field-effect transistor 58 is to sample the level of the current through the wire 20 and assure that the capacitor 62 is storing a voltage exactly proportional to the magnitude of that current at the instant that the Permalloy ribbon 22 changes polarity. Therefore, the pulses depicted in the waveforms C and D are differentiated to produce the waveforms E and F. The differentiated pulses have a sharp drop from the positive polarity pulse to and beyond zero exactly at the center of the polarity reversal of the Permalloy ribbon 22. Waveform G shows that the field-effect transistor 58 turns OFF at exactly the instant of that peak flux change and isolates, on the capacitor 62, the instantaneous voltage level that represents the magnitude of the energizing current that was needed to reverse the polarity of the Permalloy ribbon 22.
The voltage at the filter capacitor 66 represents the average or mean of the magnitudes of the levels of current at each instant of magnetic polarity reversal. This average-representing voltage is thus proportional to the difference between the current required in the wire 20 to produce a magnetic change in the ribbon 22 to one polarity and the current required in the wire 20 to produce a magnetic change in the ribbon to the opposite polarity. The difference between the current required to change to one polarity and the current required to change to the opposite polarity is directly and linearly proportional to the strength of the magnetic field surrounding the Permalloy ribbon 22. Therefore, the voltage across the capacitor 66 is linearly proportional to the strength of the magnetic field around the Permalloy ribbon 22. Since only differences in drive current magnitude survive the averaging process of the resistor 64 and the capacitor 66, the magnitude of the magnetic parameters, such as coercive force, of the material of the ribbon 22 are not reflected in the average voltage across the capacitor 66.
Referring again to the waveform H of FIG. 4, if the area under the positive polarity portions of waveform H exactly equals the area under the negative polarity portions of that waveform, the voltage across the capacitor 66 is zero. However, if the area under the positive polarity portions of waveform H is larger than the area under the negative portions of waveform H, a positive voltage will appear across the capacitor 66. The voltage across the capacitor 66 is delivered to the normal or non-inverting input of a final differential amplifier 70. The differential amplifier 70 has a zero adjusting variable resistor 72 which is used to null miscellaneous d.c. voltage offsets due to characteristic variations of the components.
A variable resistance 74 operates in a feedback loop and is connected from the output of the differential amplifier 70 back to its inverting input. The purpose of this resistor 74 is to adjust the gain of the amplifier 70 so as to calibrate the system to achieve a direct, linear measurement of the magnetic field being sensed or the current level in a given conductor which produces that magnetic field. In the case of a flat, printed conductor, the tip 16 of the probe 14 can be positioned near the center of that conductor and deliver an output calibrated directly in amperes. For a thicker conductor with the probe farther from the center of the conductor, different feedback resistance can be used to compensate for conductor cross-section geometry.
The output from the differential amplifier 70 can be used directly to drive a meter or an oscilloscope in order to sense, in a direct reading, the magnitude of the magnetic field and, thus, the magnitude of the current which produces that magnetic field in the conductor 12 of FIG. 1.
If the Permalloy ribbon 22 is placed in a magnetic field under test, that has flux lines extending substantially in the direction of the wire 20, these flux lines of the tested field and the magnetomotive force that they represent along the Permalloy ribbon 22 vectorially add to the magnetomotive force generated by the current through the wire 20 which produces flux lines perpendicular to the flux lines of the field under test. Therefore, when the polarity of the magnetic field surrounding the wire 20 vectorially adds to the polarity of the magnetic field being tested or sensed, the Permalloy ribbon 22 switches polarity at a lower value of current through the wire 20. Conversely, if the magnetic field due to the current flowing in the wire 20 vectorially opposes the magnetic field being sensed, the two magnetic fields will partially cancel one another; and a higher level of current is necessary in the wire 20 before the Permalloy ribbon 22 changes polarity.
Since the Permalloy ribbon 22 is treated so as to have a preferred magnetic direction along its length and is wound in a 45° helix about the wire 20, the vectorial sum of the orthogonal fields produces magnetization changes along the length of the ribbon 22 in a 45° helix about the wire 20.
It will be readily appreciated that the probe 14 senses and is influenced by the Earth's magnetic field as well as the local magnetic field around the conductor 12. In order to eliminate any errors which might arise from the influence of the Earth's magnetic field, another, identical sensor is mounted remote from the insulating tip 16 and well out of the influence of the magnetic field surrounding the conductor 12.
This sensor comprises a wire 20', a ribbon 22', a sensing coil 24' as well as two prenucleation coils 26' and 28'. The output of a sensing coil 24' is coupled by a step-up transformer 36' to a differential amplifier 38'. The pulses passing through two current-limiting resistors 40' and 44' are clipped by two shunting diodes 50' and 54' so that only positive pulses are differentiated by a capacitor 42' and a resistor 43' or a capacitor 46' and resistor 47'. The positive portions of the differentiated pulses pass through an OR-gate 56', momentarily to turn ON a field-effect transistor 58'.
The voltage generated across a current-sensing resistor 34', at its ungrounded end 60', is gated through the field-effect transistor 58' to charge a capacitor 62'. The output of an integrating circuit comprising a resistor 64' and a capacitor 66' is delivered to the normal or non-inverting input of a differential amplifier 70' having a zero adjust resistor 72' and a gain adjust resistor 74' which is used to adjust the gain of the amplifier 70' and thus null the effect of the Earth's magnetic field.
In order to subtract the influence of the Earth's and other ambient magnetic fields that are present in the measurement at the output of the differential amplifier 70' from the output of the differential amplifier 70, the amplifiers 70 and 70' must be counter-phased. That is, the outputs of the differential amplifiers 70 and 70' are connected in such a way that if a rising voltage at the output of the R-C integrator 64,66 produces a positive output from the differential amplifier 70, a rising voltage from the output of the R-C integrator 64', 66' must produce an output from the differential amplifier 70' that subtracts from the output of the differential amplifier 70. The counter-phasing of the differential amplifiers 70 and 70' is shown schematically in FIG. 3 with the output of the differential amplifier 70 connected through a resistor 76 to the normal or non-inverting input of a differential amplifier 78. The normal input of the differential amplifier 78 is also connected through a resistor 80 to ground. The resistors 76 and 80 form a voltage-divider network. The output of the differential amplifier 70' is connected through a resistor 81 to the inverting input of the differential amplifier 78. The output of the differential amplifier 78 is also connected through a feedback resistor 82 to the inverting input of the differential amplifier 78. The feedback resistor 82 is required to fix the gain of the differential amplifier 78. The resistor 81 is needed to prevent the low output impedance of the amplifier 70' from nullifying the effect of the feedback resistor 82. The resistors 81 and 82 together form a voltage divider. The voltage divider of the resistors 76 and 80 is needed merely to balance the effect of the voltage divider of the resistors 81 and 82.
The output of the differential amplifier 78 drives an operator interface, such as either a meter 84 or an oscilloscope 86. In this way, the reading at the meter 84 or the trace visible on the oscilloscope 86 is uninfluenced by the Earth's magnetic field, inasmuch as the effect of the Earth's magnetic field in the output of the differential amplifier 70 is diminished by the effect of that same field in the output of the differential amplifier 70'.
Although a particular embodiment of the invention is shown in the drawings and has been described in the foregoing specification, it is to be understood that other modifications of this invention, varied to fit particular operating conditions will be apparent to those skilled in the art; and the invention is not to be considered limited to the embodiment chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true scope of the invention. | A probe for sensing the strength of the magnetic field that surrounds a current-carrying conductor has a square-loop magnetic material wrapped about a conductor which is placed in the magnetic field to be sensed. An alternating signal is applied to the conductor, of sufficient intensity to cause successive reversals of the polarity of the magnetic material. A sense winding around the magnetic material issues a switch signal every time the magnetic material reverses polarity. The switch signal is used to sample the alternating drive signal current in order to store the amplitude of the drive signal at the instant at which the magnetic material reverses polarity. The sampled signal amplitude is averaged over a period of time, and the resultant amplitude is a linear function of the strength of the magnetic field. A second conductor, magnetic material and sense winding are arranged in a position remote from the magnetic field in order to sense the effect of the Earth's magnetic field. The averaged output signal resulting from the measurement of the Earth's magnetic field is then subtracted from the averaged output signal derived from the measurement of the magnetic field that surrounds the current-carrying conductor. The difference signal is displayed as an indication of the current-produced magnetic intensity or the magnitude of the electric current which produces it. | 6 |
RESEARCH GRANT
Some aspects of the invention were supported in part by U.S. Public Health Service Grant CA-02817 from the National Cancer Institute and support from the Northeast NMR Facility at Yale University insofar as the use of high resolution NMR spectra is concerned that was made possible by a grant from the Chemical Division of the National Science Foundation (Grant No. CHE-7916210).
INFORMATION DISCLOSURE UNDER 37 CFR § 1.97
5-Hydroxy-2-formylpyridine thiosemicarbazone is a well known compound that has been proposed as an anti-neoplastic agent and has received a Phase I trial in cancer patients. This agent was not chose for further development. Representative literature includes DeConti et al., "Clinical and Pharmacological Studies with 5-Hydroxy-2-formylpyridine Thiosemicarbazone", Cancer Res., 1972, 32, 1455-62. Similarly, 4-methyl-5-amino-1-formylisoquinoline thiosemicarbazone is also well known as manifested by Agrawal et al., "Potential Antitumor Agents. 13. 4-Methyl-5-amino-1-formylisoquinoline thiosemicarbazone", J. Med. Chem., 1976, 19, 970-72. Subsequent to this research, others have tried a variety of compounds which may be considered to be analogs of 2-formylpyridine thiosemicarbazones, as shown by the numerous compounds which have been synthesized and tested by French et al., "α-(N)-Formylheteroaromatic Thiosemicarbazones. * * *", J. Med. Chem., 1974, 17, 172-81. Among the various compounds reported by French et al. in Table I (page 174) may be mentioned 5-acetylamino-2-formylpyridine thiosemicarbazone (compound 49). A variety of compounds were synthesized with 4-position substitutions, as reported by Agrawal et al., "Potential Antitumor Agents. 14. 4-Substituted 2-Formylpyridine Thiosemicarbazones", J. Med. Chem., 1976, 19, 1209-14. This Agrawal et al. research reports on compounds which include 4-dimethylamino-2-formylpyridine thiosemicarbazone (page 1210, compound 5) and 4-piperidino-2-formylpyridine thiosemicarbazone (id., compound 20), 4-pyrrolidinoamino-2-formylpyridine thiosemicarbazone (page 1211, compound 28), 4-bis(hydroxyethyl)amino-2-formylpyridine thiosemicarbazone (id., compound 30) and structurally more remote forms; in no case is there a disclosure of a 2-formylpyridine thiosemicarbazone in this research of Agrawal et al. that has both one of the 4-position substituents and any substituent on the ring other than one example with a 3-methyl group (id., compound 37). French et al. have also made attempts to work in the field with 4-substitution. French et al. disclose only one compound which may be considered to be a (3 or 5)-substituted-4-methyl-2-formylpyridine thiosemicarbazone, i.e., the 3-species, 3-hydroxy-4-methyl-2-formylpyridine thiosemicarbazone, which is compound 51 and which is found to lack "significant activity." Most of the compounds among the 61 tabulated 2-formylpyridine thiosemicarbazones are indicated as possessing "significant activity," which is designated by an asterisk, as explained on page 175. An isomeric form is disclosed, namely, 3-hydroxy-6-methyl-2-formylpyridine thiosemicarbazone, which is compound 52 and which is also found to lack "significant activity."
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention there are provided compounds of the formula: ##STR2## wherein one of R 1 is NHR 4 or NR 4 R 5 or R 3 is NHR 4 , NR 4 R 5 or OH, and the other is hydrogen;
R 2 is hydrogen or C 1-4 lower alkyl;
R 4 is hydrogen, hydroxyl, or C 1-4 lower alkyl; and
R 5 is C 1-4 lower alkyl.
The term "C 1-4 lower alkyl" refers to alkyl groups of up to four carbon atoms, methyl, ethyl, propyl and butyl; in accordance with a preferred embodiment, C 1-4 lower alkyl represents methyl. In one embodiment there are provided compounds wherein R 4 is hydrogen. In a further embodiment there are provided compounds wherein R 2 is hydrogen. In a further embodiment there are provided compounds wherein R 2 is lower alkyl preferably methyl. In accordance with a preferred embodiment, R 4 is hydrogen, i.e., the compounds are 3- and 5-amino-2-formylpyridine thiosemicarbazones. The compounds may be free from further substituents in accordance with one embodiment, i.e., R 2 is hydrogen, or in a second and also preferred embodiment the compounds of the invention are 3- and 5-amino-4-methyl-2-formylpyridine thiosemicarbazones, i.e., R 2 is methyl. Representative compounds of the invention include 3-amino-2-formylpyridine thiosemicarbazone, 5-amino-2-formylpyridine thiosemicarbazone, 3-amino-4-methyl-2-formylpyridine thiosemicarbazone, 5-amino-4-methyl-2-formylpyridine thiosemicarbazone, and 5-hydroxyamino-4-methyl- 2-formylpyridine thiosemicarbazone. It is to be understood that any compound of the invention above or any other aspect should be understood as contemplating any pharmaceutically acceptable salts or hydrates thereof.
A method is provided for the treatment of tumors in mammals, e.g., cats, dogs, rats, mice, monkey and man. All of the compounds of the aforementioned first aspect of the invention are specifically considered to be useful in the treatment of tumors. For example, all compounds of the first aspect of the invention are useful in the treatment of the L1210 leukemia in mice. Dosages that are contemplated within the scope of the invention are from about 40 to about 100 mg/kg/day.
In accordance with a second aspect of the invention there is provided a method for the treatment of tumors in mammals, e.g., cats, dogs, rats, mice, monkey and man, which comprises administration of the compounds 3-hydroxy-4-methyl-2-formylpyridine thiosemicarbazone or 5-hydroxy-4-methyl-2-formylpyridine thiosemicarbazone. For example, among tumors which may be treated in accordance with the second aspect of the invention may be mentioned the treatment of the L1210 leukemia in mice. Dosages that are contemplated within the scope of the invention are from about 4 to about 600 mg/kg/day. As part of this second aspect of the invention there is also provided the novel compound 5-hydroxy-4-methyl-2-formylpyridine thiosemicarbazone.
DETAILED DESCRIPTION
The synthesis of the compounds of the first aspect of the invention is described in greater detail in the examples which follow. In general terms, there is first described the synthesis of various 3-amino, 5-amino- and 5-nitro-substituted 2-formylpyridine thiosemicarbazones. Oxidation of 3-nitro-, 5-nitro-, 3-nitro-4-methyl- and 5-nitro-4-methyl-2-picolines with selenium dioxide in refluxing dioxane yielded the corresponding 2-formylpyridines. To reduce the nitro groups to amino functions, the aldehydes were protected by conversion to the cyclic ethylene acetals, which were then reduced by catalytic hydrogenation using Pd/C as a catalyst to give the corresponding amino acetals. The resulting compounds were then reacted with thiosemicarbazide in ethanol containing 10% concentrated hydrochloric acid to form the desired thiosemicarbazone hydrochlorides; the free bases were liberated by treatment with aqueous sodium bicarbonate solution. Condensation of 5-nitro-2-formylpyridine and 5-nitro-4-methyl-2-formylpyridine, with thiosemicarbazide in the presence of hydrochloric acid, followed by treatment with sodium bicarbonate, yielded the corresponding 5-nitro-substituted thiosemicarbazones.
The acetamide and alkylsulfonamide derivatives of 3-amino- and 5-amino-2-formylpyridine thiosemicarbazone were prepared. Acetylation with acetic anhydride in anhydrous pyridine gave acetamide derivatives which were then condensed with thiosemicarbazide to produce 5-acetylamino-2-formylpyridine thiosemicarbazone and 3- and 5-acetylamino-4-methyl-2-formylpyridine thiosemicarbazones. During the process of acidic hydrolysis of the ethylene acetal groups, some hydrolysis of the acetamide functions occurred even though reaction conditions were carefully controlled. The desired pure compounds were obtained by recrystallization from ethanol or by silica gel chromatography. Treatment of 2-(1,3-dioxolanyl)-4-methyl-5-aminopyridine with methanesulfonyl chloride or p-toluenesulfonyl chloride in anhydrous pyridine afforded the corresponding 5-methanesulfonylamino and p-toluenesulfonylamino derivatives, 2-(1,3-dioxolanyl)-4-methyl-5-methanesulfonylaminopyridine and 2-(1,3-dioxolanyl)-4-methyl-5-p-toluenesulfonylaminopyridine, respectively, which were then treated with thiosemicarbazide in the presence of concentrated hydrochloric acid to afford the corresponding 5-methanesulfonylamino- and 5-p-toluenesulfonylamino-4-methyl-2-formylpyridine thiosemicarbazones, 5-methanesulfonylamino-4-methyl-2-formylpyridine thiosemicarbazone and 5-toluenesulfonylamino-4-methyl-2-formylpyridine thiosemicarbazone.
5-Hydroxyamino-4-methyl-2-formylpyridine thiosemicarbazone was synthesized by hydrogenation of 2-(1,3-dioxolanyl)-4-methyl-5-nitropyridine in ethanol using Pd(OH) 2 /C as a catalyst under 50 psi of hydrogen to yield the 5-hydroxyamino derivative contaminated with about 10-15% of the corresponding 5-amino derivative. 2-(1,3-Dioxolanyl)-4-methyl-5-hydroxyaminopyridine was easily purified by recrystallization from ethanol. The structure was assigned by NMR, mass spectroscopy and elemental analysis. During the reduction process, the rate of absorption of hydrogen decreased considerably after the formation of the 5-hydroxyamino derivative, 2-(1,3-dioxolanyl)-4-methyl-5-hydroxyaminopyridine, and the reaction was terminated at this stage. When the reaction was allowed to proceed until the absorption of hydrogen was complete (about 24 h), however, the 5-amino derivative,2-(1,3-dioxolanyl)-4-methyl-5-aminopyridine, was obtained in nearly quantitative yield.
Condensation of 2-(1,3-dioxolanyl)-4-methyl-5-hydroxyaminopyridine with thiosemicarbazide in the presence of concentrated hydrochloric acid, followed by treatment with sodium bicarbonate afforded the desired 5-hydroxyamino-4-methyl-2-formylpyridine thiosemicarbazone.
Melting points were determined with a Thomas-Hoover Unimelt apparatus and are uncorrected. 1 H NMR spectra were recorded on a Varian EM-390 90 MHz NMR spectrometer or a Bruker WM-500 500 MHz spectrometer with Me 4 Si as the internal reference. The mass spectra (at 70 eV) were provided by the Yale University Chemical Instrumentation Center. TLC was performed on EM precoated silica gel sheets containing a fluorescent indicator. Elemental analyses were carried out by the Baron Consulting Co., Orange, Conn. Where analyses are indicated only by symbols of the elements, the analytical results for those elements were within ±0.4% of the theoretical value.
Use of the compound of the present invention is preferably carried out when the compound is in a pharmaceutically acceptable salt form. Acceptable salts include, for example, inorganic acid salts such as hydrochloride and hydrobromide, organic salts such as acetate, tartrate, citrate, fumarate, maleate, toluenesulfonate, methanesulfonate, ethanesulfonate, hydroxymethanesulfonate, and hydroxyethanesulfonate, metal salts such as sodium salt, potassium salt, calcium salt, and aluminum salt, and salts with a base such as triethylamine salt, guanidine salt, ammonium salt, hydrazine salt, quinine salt, and cinchonine salt. The salts are made using procedures that will be readily apparent to those skilled in the art. Hydrates, which are also contemplated within the scope of the presently claimed invention, can be formulated using principles well known to those of ordinary skill in the art.
The presently claimed invention can be formulated as a pharmaceutical composition in accordance with procedures that will be readily apparent to those of ordinary skill in the art. Preferred pharmaceutical compositions are, for example, tablets, including lozenges and granules, caplets, dragees, pills, gelatin capsules, ampuls, and suppositories comprising the active ingredient together with a) diluents, e.g., lactose, dextrose, sucrose, mannitol, sorbitol, cellulose and/or glycine; b) lubricants, e.g., silica, talcum, stearic acid, its magnesium or calcium salt and/or polyethyleneglycol; for tablets also c) binders, e.g., magnesium aluminum silicate, starch paste, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose and/or polyvinylpyrrolidone; if desired d) disintegrants, e.g., starches, agar, alginic acid or its sodium salt, or effervescent mixtures; and/or e) absorbents, colorants, flavors and sweeteners. Injectable compositions are preferably aqueous isotonic solutions or suspensions, and suppositories are advantageously prepared from fatty emulsions or suspensions. Said compositions may be sterilized and/or contain adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure and/or buffers. In addition, they may also contain other therapeutically valuable substances. Said compositions are prepared according to conventional mixing, granulating or coating methods, respectively, and contain about 0.1 to 75%, preferably about 1 to 50%, of the active ingredient.
Suitable formulations for transdermal application include an effective amount of a compound of the invention with a carrier. Advantageous carriers include absorbable pharmacologically acceptable solvents to assist passage through the skin of the host. Characteristically, transdermal devices are in the form of a bandage comprising a backing member, a reservoir containing the compound optionally with carriers, optionally a rate controlling barrier to deliver the compound to the skin of the host at a controlled and predetermined rate over a prolonged period of time, and means to secure the device to the skin.
The following examples serve to further illustrate the invention.
EXAMPLE I
A mixture of 3-nitropyridine (1.3 g, 9.4 mmol) and selenium dioxide (1.1 g, 9.4 mmol) in 1,4-dioxane (30 mL), containing 0.8 mL of water, was refluxed under an atmosphere of nitrogen for 20 h. The reaction mixture was cooled and filtered to remove the precipitated black selenium. The filtrate was evaporated in vacuo to dryness and the residue was chromatographed on a silica gel column (CH 2 Cl 2 , R f 0.82) to afford 0.32 g (23%) of white crystals of 3-nitropyridine-2-carboxaldehyde: mp 61°-62° C. (lit. 63° C.); 1 H NMR (90 MHz, CDCl 3 ) δ 7.65 (d, 1H, 5-H, J 4 ,5 =6.0 Hz, J 5 ,6 =4.5 Hz), 8.32 (d, 1H, 4-H, J 4 ,5 =6.0 Hz), 9.05 (d, 1H, 6-H, J 5 ,6 =4.5 Hz), 10.31 (s, 1H, 2-CHO).
EXAMPLE II
5-Nitropyridine-2-carboxaldehyde was prepared from the nitro derivative, 2-methyl-3-nitropyridine, by the procedure employed for the synthesis of Example I, except that anhydrous dioxane was used as the solvent and the reaction time was 4 h. Yield: 2.0 g (42%); mp 66°-67° C. (lit. 66.5°-67.5° C.); TLC, R f 0.85 (EtOAc); 1 H NMR (90 MHz, CDCl 3 ) δ 8.0 (d, 1H, 3-H, J 3 ,4 =4.5 HZ), 8.30 (d, 1H, 4-H, J 3 ,4 =4.5 Hz), 9.25 (s, 1H, 6-H), 10.45 (s, 1H, 2-CHO).
EXAMPLE III
A mixture of 3-nitropyridine-2-carboxaldehyde (1.50 g, 9.70 mmol), ethylene glycol (7 g, 62 mmol) and p-toluenesulfonic acid monohydrate (60 mg, 0.24 mmol) in toluene (150 mL) was refluxed until the starting material was no longer observed by TLC (CH 2 Cl 2 /EtOAc, 4:1, v/v). The reaction mixture was cooled and washed with aqueous sodium bicarbonate solution, water, and brine. The organic layer was dried over MgSO 4 . The filtrate was evaporated in vacuo to dryness and the residue was chromatographed on a silica gel (120 g) column (CH 2 Cl 2 /EtOAc, 4:1, v/v, R f 0.50). The product was 2-(1,3-dioxylanyl)-3-nitropyridine, obtained as almost colorless needles (1.65 g, 87%): mp 65°-67° C.; 1 H NMR (90 MHz, CDCl 3 ) δ 4.15 (s, 4H, CH 2 CH 2 ), 6.52 (s, 1H, 2-CH), 7.52 (m, 1H, 5 -H), 8.15 (dd, 1H, 4-H, J 4 ,6 =1 Hz), 8.85 (dd, 1H, 6-H, J 5 ,6 =4 Hz, J 4 ,6 =1 Hz). Anal. (C 8 H 8 N 2 O 4 ) C, H, N.
EXAMPLE IV
2-(1,3-Dioxolanyl)-5-nitropyridine was prepared from 5-nitropyridine-2-carboxaldehyde by the procedure employed for the synthesis of Example III. Yield: 2.0 g (84%); mp 104°-105° C.; TLC R f 0.73 (CH 2 Cl 2 /EtOAc, 1:1, v/v); 1H NMR (90 MHz, CDCl 3 ) δ 4.10 (s, 4H, CH 2 CH 2 ), 5.92 (s, 1H, 2-CH), 7.72 (d, 1H, 3-H, J 3 ,4 =8 Hz), 8.50 (dd, 1H, 4-H, J 3 ,4 =8 Hz, J 4 ,6 =2 Hz), 9.42 (d, 1H, 6-H, J 4 ,6 =2 Hz). Anal.(C 8 H 8 N 2 O 4 ) C, H, N.
EXAMPLE V
A solution of 2-(1,3-dioxolanyl)-3-nitropyridine (1.00 g, 5.1 mmol) in ethanol (100 mL) was hydrogenated overnight in a Parr apparatus at 50 psi of hydrogen in the presence of 10% Pd/C (0.1 g). The reaction mixture was filtered through a Celite-pat and the catalyst was washed with ethanol. The combined filtrate and washings were evaporated in vacuo to dryness and co-evaporated with benzene. The resulting solid was recrystallized from benzene to afford 0.81 g (96%) of product, 2-(1,3-dioxolanyl)-3-aminopyridine, as white crystals: mp 73°-74° C.; TLC R f 0.4 (EtOAc); 1 H NMR (90 MHz, CDCl 3 ) δ 4.10 (m, 4H, CH 2 CH 2 ), 4.15 (br s, 2H, 3-NH 2 , D 2 O exchangeable), 5.80 (s, 1H, 2-CH), 6.90 (m, 2H, 4-H and 6-H), 7.95 (dd, 1H, 5-H). Anal. (C 8 H 10 N 2 O 2 .O.1H 2 O) C, H, N.
EXAMPLE VI
2-(1,3-Dioxolanyl)-5-aminopyridine was prepared from 2-(1,3-dioxolanyl)-5-nitropyridine by the procedure employed in Example V. Yield: 2.6 g (93%); mp 81°-82° C.; TLC R f 0.18 (EtOAc); 1 H NMR (90 MHz, CDCl 3 ) δ 3.85 (br s, 2H, 5-NH 2 , D 2 O exchangeable), 4.05 (m, 4H, CH 2 CH 2 ), 5.72 (s, 1H, 2-CH), 6.95 (dd, 1H, 4-H, J 3 ,4 =8 Hz, J 4 ,6 =2 Hz), 7.30 (d, 1H, 3-H, J 3 ,4 =8 Hz) 8.08 (d, 1H, 6-H, J 4 ,6 =2 Hz). Anal. (C 8 H 10 N 2 O 2 ) C, H, N.
EXAMPLE VII
To a solution of 2-(1,3-dioxolanyl)-3-aminopyridine (0.80 g, 4.8 mmol) in 10 mL of ethanol, 8 mL of water and 2 mL of concentrated hydrochloric acid was added 0.48 g (5.3 mmol) of thiosemicarbazide. The mixture was stirred at room temperature overnight and refluxed for 1 h, cooled and filtered. The crude yellow hydrochloride salt was dissolved in 50 mL of hot water and filtered. To the hot filtrate was added 10 mL of 5% sodium bicarbonate solution. The mixture was stirred at room temperature for 1 h, filtered and washed with water, followed by ethanol to yield 3-amino-2-formylpyridine thiosemicarbazone. Yield: 0.72 g (77%); mp 240°-241° C. dec; MS m/e 194 (M + ); 1 H NMR (90 MHz, DMSO-d 6 ) δ 6.48 (br s, 2H, 3-NH 2 , D 2 O exchangeable), 7.12 (m, 2H, 4-H and 6-H), 7.83 (dd, 1H, 5-H), 8.10 (br s, 2H, CSNH 2 , D 2 O exchangeable), 8.10 (s, 1H, 2-CH), 10.95 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 7 H 9 N 5 S) C, H, N.
EXAMPLE VIII
5-Amino-2-formylpyridine thiosemicarbazone was prepared from 2-(1,3-dioxolanyl)-5-aminopyridine by the procedure employed for the synthesis of Example VII. Yield: 1.9 g (82%); mp 205°-207° C.; MS m/e 194 (M + ); 1 H NMR (DMSO-d 6 , 500 MHz) δ 5.60 (br s, 2H, 3-NH 2 , D 2 O exchangeable), 6.95 (dd, 1H, 4-H, J 3 ,4 =8 Hz, J 4 ,6 =1.5 Hz), 7.65 (s, 1H, 2-CH), 7.75 (d, 1H, 6-H, J 4 ,6 =1.5 Hz), 7.90 (d, 1H, 3-H, J 3 ,4 =8 Hz), 7.85 and 8.10 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 11.05 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 7 H 9 N 5 S.O.4H 2 O) C, H, N.
EXAMPLE IX
3-Amino-4-methyl-2-formylpyridine thiosemicarbazone was prepared from 2-(1,3-dioxolanyl)-4-methyl-3-aminopyridine by the procedure employed for the synthesis of Example VII. Yield: 0.5 g (76%); mp 227°-228° C.; MS m/e 208 (M + ); 1 H NMR (500 MHz, DMSO-d 6 ) δ 2.25 (s, 3H, 4-CH 3 ), 6.18 (s, 2H, 3-NH 2 , D 2 O exchangeable), 7.01 (d, 1H, 5-H, J 5 ,6 =6 Hz), 7.78 (d, 1H, 6-H, J 5 ,6 =6 Hz), 7.90 (s, 2H, CSNH 2 , D 2 O exchangeable), 8.32 (s, 1 H, 2-CH), 11.31 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 8 H 11 N 5 S.HCl.H 2 O) C, H, N.
EXAMPLE X
5-Amino-4-methyl-2-formylpyridine thiosemicarbazone was prepared from 2-(1,3-dioxolanyl)-4-methyl-5-aminopyridine by the procedure employed for the synthesis of Example VII. Yield: 0.64 g (78%); mp 235°-236° C.; MS m/e 208 (M + ); 1 H NMR (500 MHz, DMSO-d 6 ) δ 2.10 (s, 3H, 4-CH 3 ), 5.48 (s, 2H, 5-NH 2 , D 2 O exchangeable), 7.80 (s, 2H, CSNH 2 , D 2 O exchangeable), 7.80 (s, 1H, 3-H), 7.95 (s, 1H, 6-H), 8.00 (s, 1H, 2-CH), 11.50 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 8 H 11 N 5 S.HCl.H 2 O) C, H, N.
EXAMPLE XI
A mixture of 5-nitropyridine-2-carboxaldehyde (0.50 g, 3.3 mmol) and thiosemicarbazide (0.36 g, 4 mmol) in 20 mL of 70% aqueous ethanol solution was refluxed for 2 h, cooled and filtered. The yellow precipitate that formed was washed with water and recrystallized from ethanol to give 0.54 g (73%) of product, 5-nitro-2-formylpyridine thiosemicarbazone: mp 215°-217° C.; 1 H NMR (90 MHz, DMSO-d 6 ) δ 8.25 (d, 1H, 3-H), 8.35 and 8.55 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 8.90 (dd, 1H, 4-H), 9.75 (d, 1H, 6-H), 10.15 (s, 1H, 2-CH), 11.95 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 7 H 7 N 5 O 2 S) C, H, N.
EXAMPLE XII
5-Nitro-4-methyl-2-formylpyridine thiosemicarbazone was prepared from 4-methyl-5-nitropyridine-2-carboxaldehyde by the procedure employed for the synthesis of Example XI. Yield: 0.38 g (88%); mp 220°-222° C.; 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.55 (s, 3H, 4-CH 3 ), 8.12 (s, 1H, 3-H), 8.30 and 8.50 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 9.15 (s, 1H, 6-H), 9.45 (s, 1H, 2-CH), 11.85 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 8 H 9 N 5 O 2 S) C, H, N.
EXAMPLE XIII
To a stirred solution of 2-(1,3-dioxolanyl)-5-aminopyridine (2.0 g, 12 mmol) in 15 mL of anhydrous pyridine in an ice bath was added dropwise 2 mL of acetic anhydride at 0.5° C. The reaction mixture was stirred overnight and evaporated in vacuo to dryness. The residue was co-evaporated with ethanol (10 mL) and recrystallized from ethanol to yield 2.1 g (82%) of product, 2-(1,3-dioxolanyl)-5-acetylaminopyridine: mp 145°-147° C.; 1 H NMR (90 MHz, CDCl 3 ) δ 2.05 (s, 3H, CH 3 ), 4.10 (m, 4H, CH 2 CH 2 ), 5.82 (s, 1H, 2-CH), 7.10 (dd, 1H, 4-H, J 3 ,4 =8 Hz, J 4 ,6 =2 Hz), 7.45 (d, 1H, 3-H, J 3 ,4 =8 Hz), 8.40 (br s, 1H, NH, D 2 O exchangeable), 8.68 (d, 1H, 6-H, J 4 ,6 =2 Hz). Anal. (C 10 H 12 N 2 O 3 ) C, H, N.
EXAMPLE XIV
A mixture of 2-(1,3-dioxolanyl)-4-methyl-3-aminopyridine (500 mg, 2.78 mmol), 5 mL of acetic anhydride and 15 mL of anhydrous pyridine was refluxed overnight and evaporated in vacuo to dryness. The residue was dissolved in CH 2 CH 2 (30 mL), washed with 10% sodium bicarbonate, brine, and water, then dried (anhydrous MgSO 4 ). The solvent was removed and the residue was purified on a silica gel column (CH 2 Cl 2 /CH 3 OH, 10:1, v/v, R f 0.67) to produce 440 mg (72%) of product, 2-(1,3-dioxolanyl)-4-methyl-3-acetylaminopyridine: mp 77°-79° C., 1 H NMR (90 MHz, CDCl 3 ) δ 2.10 (s, 3H, COCH 3 ), 2.17 (s, 3H, 4-CH 3 ), 2.20 (br s, 1H, NH, D 2 O exchangeable), 3.95 (m, 4H, CH 2 CH 2 ), 5.70 (s, 1H, 2-CH), 7.15 (d, 1H, 5-H, J 5 ,6 =6 Hz), 8.42 (d, 1H, 6-H, J 5 ,6 =6 Hz). Anal. (C 11 H 14 N 2 O 3 ) C, H, N.
EXAMPLE XV
2-(1,3-Dioxolanyl)-4-methyl-5-acetylaminopyridine was prepared from 2-(1,3-dioxolanyl)-4-methyl-5-aminopyridine by the procedure employed for the synthesis of Example XIV. Yield: 0.5 g (82%); mp 98°-99° C.; TLC, R f 0.65 (CH 2 Cl 2 /EtOH, 10:1, v/v); 1 H NMR (90 MHz, CDCl 3 ) δ 2.08 (s, 3H, COCH 3 ), 2.15 (s, 3H, 4-CH 3 ), 4.05 (m, 4H, CH 2 CH 2 ), 5.72 (s, 1H, 2-CH), 7.30 (s, 1H, 3-H), 8.05 (br s, 1H, NH, D 2 O exchangeable), 8.58 (s, 1H, 6-H). Anal. (C 11 H 14 N 2 O 3 ) C, H, N.
EXAMPLE XVI
A mixture of 2-(1,3-dioxolanyl)-5-acetylaminopyridine (0.60 g, 3.6 mmol), thiosemicarbazide (0.40 g, 4.4 mmol), 1 mL of glacial acetic acid and 10 mL of ethanol was heated with stirring at 50° C. for 6 h, cooled and filtered. The acetic acid salt was dissolved in hot water, filtered into 15 mL of 5% sodium bicarbonate solution and the mixture was stirred at room temperature for 1 h. The yellow precipitate that formed was filtered, washed with water, and recrystallized from ethanol twice to give 0.46 g (54%) of product, 5-acetylamino-2-formylpyridine thiosemicarbazone: mp 215°-217° C.; 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.05 (s, 3H, COCH 3 ), 8.00 (m, 3H, 2-CH, 3-H and 4-H), 8.05 and 8.15 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 8.80 (d, 1H, 6-H, J 4 ,6 =1.5 Hz), 10.30 (s, 1H, 5-NH, D 2 O exchangeable), 11 30 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 9 H 11 N 5 OS) C, H, N.
EXAMPLE XVII
A mixture of 2-(1,3-dioxolanyl)-4-methyl-3-acetylaminopyridine (0.41 g, 1.9 mmol), thiosemicarbazone (0.2 g, 2.2 mmol), 1 mL of concentrated hydrochloric acid and 10 mL of ethanol was stirred at room temperature overnight. The yellow precipitate (hydrochloride salt) that formed was filtered and washed with water, followed by ethanol. The hydrochloride salt was dissolved in hot water and stirred with 10 mL of 5% sodium bicarbonate solution for 1 h, filtered, and washed with water. The crude product was chromatographed on a silica gel column (CH 2 Cl 2 /CH 3 OH, 4:1, v/v, R f 0.52) to give 0.21 g (45%) of product, 3-acetylamino-4-methyl-2-formylpyridine thiosemicarbazone: mp 225°-227° C.; 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.05 (s, 3H, COCH 3 ), 2.18 (s, 3H, 4-CH 3 ), 7.30 (d, 1H, 5-H, J 5 ,6 = 6 Hz), 8.14 (d, 1H, 2-CH), 7.90 and 8.30 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 8.35 (d, 1H, 6-H, J 5 ,6 =6 Hz), 9.71 (s, 1H, 3-NH, D 2 O exchangeable), 11.53 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 10 H 13 N 5 OS) C, H, N.
EXAMPLE XVIII
5-Acetylamino-4-methyl-2-formylpyridine thiosemicarbazone was prepared from 2-(1,3-dioxolanyl)-4-methyl-5-acetylaminopyridine by the procedure employed for the synthesis of Example XVII. Yield: 0.42 g (76%); mp 229°-231° C.; TLC, R f 0.52 (CH 2 Cl 2 /CH 3 OH, 4:1, v/v); 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.10 (s, 3H, COCH 3 ), 2.25 (s, 3H, 4-CH 3 ), 7.90 (s, 1H, 3-H), 8.05 (s, 1H, 2-CH), 8.05 and 8.35 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 8.60 (s, 1H, 6-H), 9.62 (s, 1H, 5-NH, D 2 O exchangeable), 11.60 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 10 H 13 N 5 OS) C, H, N.
EXAMPLE XIX
To a stirred solution of 2-(i,3-dioxolanyl)-4-methyl-5-aminopyridine (0.8 g, 4.4 mmol) in 10 mL of anhydrous pyridine in an ice bath was added dropwise 0.6 g (5.3 mmol) of methanesulfonyl chloride at 0°-5° C. The mixture was stirred at room temperature overnight and evaporated in vacuo to dryness. The residue was co-evaporated with toluene (10 mL) and then partitioned between CH 2 CH 2 (30 mL) and water (10 mL). The organic layer was washed with 10% sodium bicarbonate, brine and water, dried with anhydrous MgSO 4 , and filtered. The filtrate was concentrated to a small volume and purified on a silica gel column (EtOAc, R f 0.40) to give 0.68 g of product, 2-(1,3-dioxolanyl)-4-methyl-5-methanesulfonylaminopyridine: mp 128°-130° C.; 1H NMR (90 MHz, CDCl 3 ) δ 2.40 (s, 3H, 4-CH 3 ), 3.03 (s, 3H, CH 3 SO), 4.12 (m, 4H, CH 2 CH 2 ), 5.65 (s, 1H, 2-CH), 7.40 (s, 1H, 3-H), 8.10 (br s, 1H, NH, D 2 O exchangeable), 8.52 (s, 1H, 6-H). Anal. (C 10 H 14 N 2 O 4 S) C, H, N.
EXAMPLE XX
2-(1,3-Dioxolanyl)-4-methyl-5-p-toluenesulfonylaminopyridine was prepared from 2-(1,3-dioxolanyl)-4-methyl-5-aminopyridine by a procedure similar to that employed in Example XIX. Yield: 0.75 g (77%); mp 155°-156° C.; 1 H NMR (90 MHz, CDCl 3 ) δ 2.05 (s, 3H, ArCH 3 ), 2.32 (s, 3H, 4-CH 3 ), 4.10 (m, 4H, CH 2 CH 2 ), 5.70 (s, 1H, 2-CH), 6.50 (br s, 1H, NH, D 2 O exchangeable), 7.20-7.40 (m, 5H, ArH and 3-H), 8.20 (s, 1H, 6-H). Anal. (C 16 H 18 N 2 O 4 S) C, H, N.
EXAMPLE XXI
A mixture of 2-(1,3-dioxolanyl)-4-methyl-5-methanesulfonylaminopyridine (0.93 g, 3.6 mmol), thiosemicarbazide (0.37 g, 4.0 mmol) and 10 mL of 5% hydrochloric acid solution was heated with stirring at 60° C. for 4 h and cooled. The yellow precipitate (hydrochloride salt) that formed was filtered and washed with a small amount of water. The hydrochloride salt was then stirred in 10 mL of 1 N NaOH solution for 30 min and filtered. The filtrate was neutralized with dilute acetic acid, filtered, washed with water followed by ethanol to give 0.65 g (63%) of product, 5-methanesulfonylamino-4-methyl-2-formylpyridine thiosemicarbazone: mp 210°-212° C.; 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.35 (s, 3H, 4-CH 3 ), 3.05 (s, 3H, 4-CH 3 SO), 8.05 (s, 1H, 3-H), 8.22 (s, 1H, 6-H), 8.30 (s, 1H, 2-CH), 8.15 and 8.35 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 9.45 (br s, 1H, SO 2 NH, D 2 O exchangeable), 11.45 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 9 H 13 N 5 O 2 S 2 .O.75 H 2 O) C, H, N.
EXAMPLE XXII
5-Toluenesulfonylamino-4-methyl-2-formylpyridine thiosemicarbazone was prepared from 2-(1,3-dioxolanyl)-4-methyl-5-p-toluenesulfonylaminopyridine by the procedure employed for the synthesis of Example XXI. Yield: 0.43 g (80%); mp 234°-236° C.; 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.12 (s, 3H, ArCH 3 ), 2.40 (s, 3H, 4-CH 3 ), 7.30-7.40 (m, 4H, ArH), 8.05 (s, 1H, 3-H), 8.20 (s, 1H, 6-H), 8.30 (s, 1H, 2-CH), 8.35 and 8.55 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 9.40 (br s, 1H, SO 2 NH, D 2 O exchangeable), 11.55 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 15 H 17 N 5 O 2 S 2 ) C, H, N.
EXAMPLE XXIII
A solution of 2-(1,3-dioxolanyl)-4-methyl-5-nitropyridine (1.8 g, 8.6 mmol) in ethanol (100 mL) was hydrogenated for 2 h in a Parr apparatus at 50 psi of hydrogen in the presence of 20% Pd(OH) 2 /C (0.2 g). The reaction mixture was filtered through a Celite-pat and the catalyst was washed with ethanol. The combined filtrate and washings were evaporated in vacuo to dryness. The residue was recrystallized from ethanol twice to give 1.0 g (60%) of product: mp 180°-181° C. as white crystals of 2-(1,3-dioxolanyl)-4-methyl-5-hydroxyaminopyridine; MS m/e 167 (M + +1); 1 H NMR (500 MHz, DMSO-d 6 ) δ 2.08 (s, 3H, 4-CH 3 ), 3.90-4.05 (m, 4H, CH 2 CH 2 ), 5.54 (s, 1H, 2-CH), 7.13 (s, 1H, 3-H), 8.18 (s, 1H, 6-H), 8.29 (s, 1H., NH, D 2 O exchangeable), 8.45 (s, 1H, OH, D 2 O exchangeable). Anal. (C 9 H 12 N 2 O 3 ) C, H, N.
EXAMPLE XXIV
5-Hydroxyamino-4-methyl-2-formylpyridine thiosemicarbazone was prepared from 2-(1,3-dioxolanyl)-4-methyl-5-hydroxyaminopyridine by the procedure employed for the synthesis of Example VII. Yield: 0.45 g (77%); mp 197°-198° C.; MS m/e 224 (M + ); 1 H NMR (90 MHz, DMSO-d 6 ) δ 2.35 (s, 3H, 4-CH 3 ), 8.12 (m, 3H, 3-H, 6-H and 2-CH), 8.55 and 8.75 (two br s, 2H, CSNH 2 , D 2 O exchangeable), 9.15 (br s, 2H, HONH, D 2 O exchangeable), 12.10 (s, 1H, NNH, D 2 O exchangeable). Anal. (C 8 H 11 N 5 OS) C, H, N.
The following discussion relates to the biological activities of the compounds of the first aspect of the invention represented by the experimental work of Examples I-XXIV.
The tumor-inhibitory properties of the substituted 2-formylpyridine thiosemicarbazones measuring their effects on the survival time of mice baring the L1210 leukemia.
EXAMPLE XXV
5-Hydroxy-2-formylpyridine thiosemicarbazone was used as a standard for comparison with the compounds of the invention which are tested in the following examples. The 5-hydroxy-2-formylpyridine thiosemicarbazone was administered by intraperitoneal injection, beginning 24 hours after tumor implantation with the maximum effective daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. (The number of mice tested was in the amount of 5-10 per dosage level). The average percentage change in body weight from onset to termination of the therapy was +2.0. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, which was determined to be 133.
It is noted that while a value of 133 was obtained, in reports by French et al., supra, a value of 268 was reported. The difference may be due to the L1210 leukemia cell lines employed or differences in the schedule of drug administration. Although the compound was administered by intraperitoneal injection starting 24 h after tumor inoculation both in this Example and in the French et al. study, the present Example employed six daily treatments, while French et al. used daily treatments, continued until half the test animals were dead.
EXAMPLE XXVI
3-Amino-2-formylpyridine thiosemicarbazone was administered by intraperitoneal injection to mice bearing the L1210 leukemia, beginning 24 hours after tumor implantation, with the maximum effective daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. (The number of mice tested was in the amount of 5-10 per dosage level). The average percentage change in body weight from onset to termination of the therapy was -5.9. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 187, which compares favorably with the value for the reference standard used in the test in Example XXV, 5-hydroxy-2-formylpyridine thiosemicarbazone, which has a value of 133.
EXAMPLE XXVII
5-Amino-2-formylpyridine thiosemicarbazone was administered by intraperitoneal injection to mice bearing the L1210 leukemia, beginning 24 hours after tumor implantation, with the maximum effective daily dosage being 20 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. (The number of mice tested was in the amount of 5-10 per dosage level). The average percentage change in body weight from onset to termination of the therapy was -2.8. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 140, which compares favorably with the value for the reference standard used in the test in Example XXV, 5-hydroxy-2-formylpyridine thiosemicarbazone, which has a value of 133.
EXAMPLE XXVIII
3-Amino-4-methyl-2-formylpyridine thiosemicarbazone was administered by intraperitoneal injection to mice bearing the L1210 leukemia, beginning 24 hours after tumor implantation, with the maximum effective daily dosage being 20 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. (The number of mice tested was in the amount of 5-10 per dosage level). The average percentage change in body weight from onset to termination of the therapy was -2.8. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 190, which compares favorably with the value for the reference standard used in the test in Example XXV, 5-hydroxy-2-formylpyridine thiosemicarbazone, which has a value of 133.
EXAMPLE XXIX
5-Amino-4-methyl-2-formylpyridine thiosemicarbazone was administered by intraperitoneal injection to mice bearing the L1210 leukemia, beginning 24 hours after tumor implantation, with the maximum effective daily dosage being 20 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. (The number of mice tested was in the amount of 5-10 per dosage level). The average percentage change in body weight from onset to termination of the therapy was -7.0. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 138, which compares favorably with the value for the reference standard used in the test in Example XXV, 5-hydroxy-2-formylpyridine thiosemicarbazone, which has a value of 133.
EXAMPLE XXX
5-Hydroxyamino-4-methyl-2-formylpyridine thiosemicarbazone was administered by intraperitoneal injection to mice bearing the L1210 leukemia, beginning 24 hours after tumor implantation, with the maximum effective daily dosage being 10 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. (The number of mice tested was in the amount of 5-10 per dosage level). The average percentage change in body weight from onset to termination of the therapy was -2.7. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 136, which compares favorably with the value for the reference standard used in the test in Example XXV, 5-hydroxy-2-formylpyridine thiosemicarbazone, which has a value of 133.
The following examples relate to the second aspect of the invention:
EXAMPLES XXXI-XXXII
Fuming sulfuric acid (1500 g, 15.3 mol) was added slowly to 2,4-lutidine (165 mL, 1.43 mol) and cooled in an ice bath with stirring. Potassium nitrate (262.5 g, 2.60 mol) was then added slowly. The reaction mixture was gradually heated to 100° C. and maintained at this temperature for 8 h. The reaction mixture was then heated at 120° C. for an additional 8 h. After cooling to room temperature, the reaction mixture was poured onto ice (2.5 kg). The solution was neutralized to pH 7 using potassium carbonate and extracted with chloroform (3×4 L). The organic layer was dried over anhydrous Na 2 SO 4 and the solvent was evaporated; the remaining solution was distilled under reduced pressure. 3-Nitro-2,4-dimethylpyridine (41.71 g, 0.27 mol, 19%, 37° C./0.24 mm Hg), 5-nitro-2,4-dimethylpyridine (38.18 g, 0.25 mol, 18%, 44° C./0.17 mm Hg) and a mixture of 3- and 5-nitro-2,4-dimethylpyridine (13.74 g, 0.09 mol) were obtained. 3-Nitro-2,4-dimethylpyridine: 1 H NMR (90 MHz, CDCl 3 ) δ 2.33 (s, 3H, 4-CH 3 ), 2.53 (s, 3H, 2-CH 3 ), 7.02 (d, 1H, 5-H, J 5 ,6 =4.5 Hz), 8.35 (d, 1H, 6-H, J 5 ,6 =4.5 Hz). 5-Nitro-2,4-dimethylpyridine: 1 H NMR (90 MHz, CDCl 3 ) δ 2.70 (s, 6H, 2- and 4-CH 3 ), 7.17 (s, 1H, 3-H), 9.10 (s, 1H, 6-H).
EXAMPLE XXXIII
To a solution of 3-nitro-2,4-dimethylpyridine of Example XXXI (31.4 g, 0.21 mol) in 200 mL of absolute ethanol was added 5% Pd-C (2 g). The mixture was hydrogenated under 59 psi of pressure for 2 h. The solution was filtered and the solvent was evaporated in vacuo to give a solid (24.0 g, 98%): mp 48°-50° C. (lit. 51°-53° C.). The product, 3-amino-2,4-dimethylpyridine, appeared homogeneous on TLC and by NMR analysis and was used without further purification. 1 H NMR (90 MHz, CDCl 3 ) δ 2.17 (s, 3H, 4-CH 3 ), 2.33 (s, 3H, 2-CH 3 ), 3.60 (s, 2H, 3-NH 2 , D 2 O exchangeable), 6.85 (d, 1H, 5-H, J 5 ,6 =4.5 Hz), 7.85 (d, 1H, 6-H, J 5 ,6 =4.5 Hz).
EXAMPLE XXXIV
5-Amino-2,4-dimethylpyridine was synthesized by methodology used for Example XXXIII except that the starting material was 5-nitro-2,4-dimethylpyridine. Yield: 24.1 g (98%); mp 62°-64° C. (lit. 66°-68° C.); 1 H NMR (90 MHz, CDCl 3 ) δ 2.10 (s, 3H, 4-CH 3 ), 2.37 (s, 3H, 2-CH 3 ), 3.33 (s, 2H, 3-NH 2 , D 2 O exchangeable), 6.70 (s, 1H, 3-H), 7.79 (s, 1H, 6-H).
EXAMPLE XXXV
To a solution of 3-amino-2,4-dimethylpyridine (25.0 g, 0.21 mol) in 10% sulfuric acid (405 mL) cooled to 0° C. by dry ice in acetone with stirring, a solution of sodium nitrite (16.2 g, 0.23 mol) in 160 mL of water was added dropwise at 0.5° C. over a period of 7 min. The solution was maintained at 0° C. for an additional 15 min and then heated in a steam-bath for 15 min. After cooling to room temperature, the solution was neutralized with K 2 CO 3 to pH 7. The product was then extracted with chloroform (3×500 mL). The organic layer was dried over anhydrous Na 2 SO 4 and the solvent was removed in vacuo. The product was recrystallized from acetone, and the mother liquid was purified by silica gel column chromatography (EtOAc) to afford an additional amount of the pure product, 3-hydroxy-2,4-dimethylpyridine. The total yield was 12.7 g (51 %) as a colorless solid: mp 105°-106° C. (lit. 99°-101° C.); 1 H NMR (90 MHz, CDCl 3 ) δ 2.25 (s, 3H, 4-CH 3 ), 2.50 (s, 3H, 2-CH 3 ), 6.97 (d, 1H, 5-H, J 5 ,6 =4.5 Hz), 7.95 (d, 1H, 6-H, J 5 ,6 =4.5 Hz), 11.20 (s, 1H, 5-OH, D 2 O exchangeable).
EXAMPLE XXXVI
5-Hydroxy-2,4-dimethylpyridine was synthesized by methodology used for Example XXXV except that the starting material was 5-amino-2,4-dimethylpyridine. Yield: 12.6 g (51%) as a colorless solid; mp 146°-148° C. (lit. 144°-146° C.); 1 H NMR (90 MHz, CDCl 3 ) δ 2.20 (s, 3H, 4-CH 3 ), 2.47 (s, 3H, 2-CH 3 ), 6.87 (s, 1H, 3-H), 7.97 (s, 1H, 6-H), 11.43 (s, 1H, 5-OH, D 2 O exchangeable).
EXAMPLE XXXVII
To a stirred solution of 3-hydroxy-2,4-dimethylpyridine (23.7 g, 0.19 mol) in 130 mL of glacial acetic acid was added dropwise 36 mL of 30% hydrogen peroxide. The reaction mixture was heated to 80° C. and two additional portions of 30% hydrogen peroxide (36 mL) were added at 3 h intervals. The solution was maintained at 80° C. for a total of 9 h and the solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (EtOAc-MeOH, 7:3, v/v) to give 10.3 g (38%) of product, 3-hydroxy-2,4-dimethylpyridine-N-oxide: mp 134°-136° C.; 1 H NMR (90 MHz, Me 2 SO-d 6 ) δ 2.17 (s, 3H, 4-CH 3 ), 2.32 (s, 3H, 2-CH 3 ), 6.94 (d, 1H, 5-H, J 5 ,6 =6 Hz), 7.72 (s, 1H, 6-H, J 5 ,6 =6 Hz); HRMS (FAB) m/z cacld. for C 7 H 9 NO 2 140.0711, found 140.0707. Anal. (C 7 H 9 NO 2 ) C, H, N.
EXAMPLE XXXVIII
5-Hydroxy-2,4-dimethylpyridine-N-oxide was synthesized by methodology used for Example XXXVII except that the starting material was 5-hydroxy-2,4-dimethylpyridine. Yield: 10.0 g (37%); mp 229° C. dec; 1 H NMR (90 MHz, Me 2 SO-d 6 ) δ 2.10 (s, 3H, 4-CH 3 ), 2.22 (s, 3H, 2-CH 3 ), 7.07 (s, 1H, 3-H), 7.70 (s, 1H, 6-H); HRMS (FAB) m/z cacld. for C 7 H 9 NO 2 140.0711, found 140.0722.
EXAMPLE XXXIX
A mixture of 3-hydroxy-2,4-dimethylpyridine-N-oxide (11.3 g, 81 mmol) and acetic anhydride (200 mL was heated at 110° C. with stirring for 2.5 h. After cooling, the solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (EtOAc-hexane, 1:1, v/v) to yield 13.5 g (74%) of product, 3-acetoxy-4-methyl-2-acetoxymethylpyridine, as a slightly yellow oil. 1 H NMR (90 MHz, CDCl 3 ) δ 2.20 (s, 3H, 4-CH 3 ), 2.37 (s, 6H, 2-OCOCH 3 ), 5.17 (s, 2H, 2-CH 2 ), 7.15 (d, 1H, 5-H, J 5-6 =4.5 Hz), 8.35 (d, 1H, 6-H, J 5-6 =4.5 Hz); HRMS (FAB) m/z cacld. for C 11 H 13 NO 4 224.0923, found 224.0935. Anal. (C 11 H 13 NO 4 ) C, H, N.
EXAMPLE XL
5-Acetoxy-4-methyl-2-acetoxymethylpyridine was synthesized by methodology used for Example XXXIX except that the starting material was 5-hydroxy-2,4-dimethylpyridine-N-oxide. Yield: 9.85 g (54%) as a yellow oil. 1 H NMR (90 MHz, CDCl 3 ) δ 2.15 and 2.25 (two s, 6H, 2-OCOCH 3 ), 2.35 (s, 3H, 4-CH 3 ), 5.13 (s, 2H, 2-CH 2 ), 7.23 (s, 1H, 3-H), 8.23 (s, 1H, 6-H); HRMS (FAB) m/z cacld. for C 11 H 13 NO 4 224.0923, found 224.0943. Anal. (C 11 H 13 NO 4 ) C, H, N.
EXAMPLE XLI
To a solution of 3-acetoxy-4-methyl-2-acetoxymethylpyridine (13.5 g, 60 mmol) in 74 mL of glacial acetic acid was added dropwise with stirring 21 mL of 30% hydrogen peroxide. The mixture was heated to 80° C. and two additional portions of 30% hydrogen peroxide (21 mL) was added at 3 h intervals. The solution was maintained at 80° C. for a total of 9 h. The solvent was evaporated in vacuo and the residue was purified by silica gel column chromatography (EtOAc-MeOH, 7:3, v/v) to give 2.62 g (18%) of product, 3-acetoxy-4-methyl-2-acetoxymethylpyridine-N-oxide: mp >360° C. The product was used immediately for the next step.
EXAMPLE XLII
A mixture of 3-acetoxy-4-methyl-2-acetoxymethylpyridine-N-oxide (2.77 g, 11.6 mmol) and 54 mL of acetic anhydride was heated with stirring at 110° C. for 2.5 h. After cooling, the solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (EtOAc-hexane, 1:1, v/v) to yield 1.54 g (47%) of product, 3-acetoxy-4-methyl-2-diacetoxymethylpyridine, as a yellow oil: 1 H NMR (90 MHz, CDCl 3 ) δ 2.10-2.40 (m, 12H, 2-C(OCOCH 3 ) 2 , 3-OCOCH 3 and 4-CH 3 ), 5.17 (s, 2H, 2-CH 2 ), 7.20-7.38 (m, 1H, 5-H), 8.37-8.52(m, 1H, 6-H); HRMS (FAB) m/z cacld. for C 13 H 15 NO 6 282.0978, found 282.0990. Anal. (C 13 H 15 NO 6 ) C, H, N.
EXAMPLE XLIII
To a slurry of thiosemicarbazide (0.26 g, 2.9 mmol) in 5 mL of conc. HCl and 15 mL of ethanol was added a solution of 3-acetoxy-4-methyl-2-diacetoxymethylpyridine (0.8 g, 2.9 mmol) in 10 mL of ethanol. The reaction mixture was stirred at 50° C. for 2 h and the precipitate was filtered after cooling. The yellow solid was recrystallized from aqueous ethanol solution (1:1, v/v) containing 5% conc. HCl to afford 0.25 g (35%) of product 3-hydroxy-4-methyl-2-formylpyridine thiosemicarbazone as the hydrochloride salt: mp 243° C. dec; 1 H NMR (500 MHz, Me 2 SO-d 6 ) δ 2.52 (s, 3H, 4-CH 3 ), 3.80 (br, s, 1H, 3-OH, D 2 O exchangeable), 7.73 (d, 1H, 5H, J 5-6 =4.5 Hz), 8.27 (d, 1H, 6-H, J 5-6 =4.5 Hz), 8.35 (s, 1H, 2-CH), 8.66 and 8.88 (two s, 2H, NH 2 , D 2 O exchangeable), 12.07 (s, 1H, NH, D 2 O exchangeable). HRMS (FAB) m/z cacld. for C 8 H 10 N 4 OS 211.0654, found 211.0651. Anal. (C 8 H 10 N 4 OS.HCl.H 2 O) C, H, N.
The hydrochloride was stirred in 10% sodium bicarbonate to yield the free base: mp 227°-228° C. dec (lit. mp 223°-224° C.); 1 H NMR (500 MHz, Me 2 SO-d 6 ) δ 2.23 (s, 3H, 4-CH 3 ), 4.80 (br s, 1H, 3-OH, D 2 O exchangeable), 7.26 (d, 1H, 5H, J 5 ,6 =5 Hz), 8.05 (d, 1H, 6-H, J 5 ,6 =5 Hz), 8.20 (s, 2H, NH 2 , D 2 O exchangeable), 8.35 (s, 1H, 2-CH), 11.80 (s, 1H, NH, D 2 O exchangeable).
EXAMPLE XLIV
To a solution of 2-(1,3-dioxolanyl)-4-methyl-3-aminopyridine (0.60 g, 3.3 mmol) in 15 mL of 10% H 2 SO 4 at 0° C. (ice bath) with stirring was added dropwise a solution of NaNO 2 (0.38 g, 5.5 mmol) in 3 mL of water. The mixture was stirred at 0° C. for 15 min and then heated in a steam-bath for 30 min. The resulting solution was evaporated at room temperature under reduced pressure to yield 3-hydroxy-4-methyl-2-formylpyridine as a syrup, which was dissolved in 15 mL of water, decolorized with charcoal and filtered. To the filtrate was added a solution of thiosemicarbazide (0.31 g, 3.3 mmol) in 5 mL of 5% HCl. The mixture was refluxed for 30 min, cooled and the yellow precipitate was filtered, washed with water, and recrystallized from aqueous ethanol solution (1:1, v/v) containing 5% conc. HCl to afford 0.21 g (30%) of product: the mp and all spectroscopic data were identical with those obtained in Example XLIII.
EXAMPLE XLV
A mixture of 5-acetoxy-4-methyl-2-acetoxymethylpyridine (6.2 g, 4.5 mmol) and 200 mL of conc. HCl was refluxed for 1 h. After cooling, the reaction mixture was evaporated to dryness under reduced pressure and the residue was purified by silica gel column chromatography (EtOAc-MeOH, 7:3, v/v) to give 3.8 g (97%) of product, 5-hydroxy-4-methyl-2-hydroxymethylpyridine: mp 161°-162° C.: 1 H NMR (90 MHz, Me 2 SO-d 6 ) δ 2.33 (s, 3H, 4-CH 3 ), 4.70 (s, 2H, 2-CH 2 ), 7.67 (s, 1H, 3-H), 8.22 (s, 1H, 6-H); HRMS (FAB) m/z cacld. for C 7 H 9 NO 2 140.0711, found 140.0736.
EXAMPLE XLVI
Method A. To a solution of 5-hydroxy-4-methyl-2-hydroxymethylpyridine (3.9 g, 28 mmol) in 100 mL of ethanol was added MnO 2 (10.0 g, 0.12 mmol) and the reaction mixture was heated to reflux for 2 h with stirring. The mixture was filtered and the filtrate was concentrated under reduced pressure to 80 mL. Because the aldehyde, 5-hydroxy-4-methyl-2-formylpyridine, is unstable, conc. HCl (8 mL) was added immediately. Thiosemicarbazide (1.5 g, 17 mmol) was added to the aldehyde solution with stirring and the reaction mixture was heated to reflux for 30 min. The precipitate was filtered upon cooling and recrystallized in aqueous ethanol solution (1:1, v/v) containing 5% conc. HCl to afford 3.3 g (81%) of product, 5-hydroxy-4-methyl-2-formylpyridine thiosemicarbazone: mp 229° C.; 1 H NMR (500 MHz, Me 2 SO-d 6 ) δ 2.33 (s, 3H, 4-CH 3 ), 4.01 (br s, 1H, 5-OH, D 2 O exchangeable), 8.02 (s, 1H, 3-H), 8.20 (s, 1H, 6-H), 8.22 (s, 1H, 2-CH), 8.58 (s, 2H, NH 2 , D 2 O exchangeable), 12.0 (s, 1H, NH, D 2 O exchangeable). HRMS (FAB) m/z cacld. for C 8 H 10 N 4 OS 211.0654, found 211.0671. Anal. (C 8 H 10 N 4 OS.HCl.H 2 O) C, H, N.
The hydrochloride was stirred in 10% sodium bicarbonate to yield the free base: mp 220°-222° C. dec; 1 H NMR (500 MHz, Me 2 SO-d 6 ) δ 2.15 (s, 3H, 4-CH 3 ), 7.95 (s, 1H, 3-H), 7.97 (s, 1H, 6-H), 8.01 (s, 1H, 2-CH), 8.04 and 8.18 (two s, 2H, NH 2 , D 2 O exchangeable), 10.1 (s, 1H, 5-OH, D 2 O exchangeable), 12.0 (s, 1H, NH, D 2 O exchangeable).
Method B. This compound was also prepared from the corresponding 5-amino derivative, 2-(1,3-dioxolanyl)-4-methyl-5-aminopyridine, via the aldehyde, 5-hydroxy-4-methyl-2-formylpyridine, by the same procedure described for the synthesis of 3-hydroxy-4-methy-2-formylpyridine thiosemicarbazone. Yield: 0.32 g (46%); the mp and all spectroscopic data were identical with those obtained in Method A.
EXAMPLE XLVII
A mixture of 2,4-dimethyl-3-nitropyridine (5.0 g, 33 mmol) and selenium dioxide (4.5 g, 42 mmol) in anhydrous 1,4-dioxane (100 mL) was refluxed under an atmosphere of nitrogen for 35 h. The reaction mixture was cooled and filtered to remove the precipitated black selenium. The filtrate was evaporated in vacuo to dryness and the residue was chromatographed on a silica gel (120 g) column (CH 2 Cl 2 -EtOAc, 10:1, v/v, R f 0.65) to afford 1.1 g (20%) of white crystals of 4-methyl-3-nitropyridine-2-carboxaldehyde: mp 101°-102° C.; 1 H NMR (90 MHz, CDCl 3 ) δ 2.35 (s, 3H, 4-CH 3 ), 7.47 (d, 1H, 5-H, J 5 ,6 =4.5 Hz), 8.72 (d, 1H, 6-H, J 5 ,6 =4.5 Hz), 9.95 (s, 1H, 2-CHO). Anal. (C 7 H 6 N 2 O 3 ) C, H, N.
EXAMPLE XLVIII
4-Methyl-5-nitropyridine-2-carboxaldehyde was prepared from the nitro derivative, 5-nitro-2,4-dimethylpyridine, by the same procedure described for the synthesis of Example XLVII, except that the reaction time was 4 h. Yield: 6.0 g (55%); mp 82°-83° C. (lit. 81°-82° C.); TLC, R f 0.86 (CH 2 Cl 2 /EtOAc, 3:2, v/v); 1 H NMR (90 MHz, CDCl 3 ) δ 2.70 (s, 3H, 4-CH 3 ), 7.90 (s, 1H, 3-H), 9.20 (s, 1H, 6-H), 10.10 (s, 1H, 2-CHO).
EXAMPLE XLIX
To 0.75 g (14 mmol) of 4-methyl-3-nitropyridine-2-carboxaldehyde in 100 mL of toluene was added 40 mg of p-toluenesulfonic acid monohydrate and 2 mL of ethylene glycol. The reaction mixture was refluxed with stirring, using a Dean-stark trap to remove the water formed during condensation until complete disappearance of the starting material was observed. The mixture was cooled and then washed with 25 mL of 10% NaHCO 3 solution, followed by 25 mL of water. The toluene layer was dried over anhydrous MgSO 4 and the solvent was removed under reduced pressure. The residue was chromatographed on a silica gel (120 g) column (CH 2 Cl 2 -EtOAc, 10:1, v/v, R.sub. 0.42) to afford 1.1 g (85%) of white crystals of 2-(1,3-dioxolanyl)-4-methyl-3-nitropyridine: mp 46°-48° C.; 1 H NMR (90 MHz, CDCl 3 ) δ 2.40 (s, 3H, 4-CH 3 ), 4.07 (s, 4H, CH 2 CH 2 ), 6.05 (s, 1H, 2-CH), 7.30 (d, 1H, 5-H, J 5 ,6 =4.5 Hz), 8.60 (d, 1H, 6-H, J 5 ,6 =4.5 Hz). Anal. (C 9 H 10 N 2 O 4 ) C, H, N.
EXAMPLE L
2-(1,3-Dioxolanyl)-4-methyl-5-nitropyridine was synthesized by the method of Example XLIX except that the starting material was 4-methyl-5-nitropyridine-2-carboxaldehyde. Yield: 2.3 g (91%); mp 77°-79° C.; (lit mp 77° C.); TLC, R f 0.74 (CH 2 Cl 2 /EtOAc, 3:2, v/v); 1 H NMR (90 MHz, CDCl 3 ) δ 2.65 (s, 3H, 4-CH 3 ), 4.10 (s, 4H, CH 2 CH 2 ), 5.85 (s, 1H, 2-CH), 7.50 (s, 1H, 3-H), 9.12 (s, 1H, 6-H). Anal. (C 9 H 10 N 2 O 4 ) C, H, N.
EXAMPLE LI
The nitro derivative, 2-(1,3-dioxolanyl)-4-methyl-3-nitropyridine (1.1 g, 5.2 mmol), was dissolved in 200 mL of ethanol and hydrogenated in a Parr apparatus under 50 psi of pressure in the presence of 10% Pd-C (200 mg) for 20 h. After filtration, the filtrate was evaporated under reduced pressure to give the product (0.9 g, 94%) as a syrup, ninhydrin positive 2-(1,3-dioxolanyl)-4-methyl-3-aminopyridine; 1 H NMR (90 MHz, CDCl 3 ) δ 2.12 (s, 3H, 4-CH 3 ), 4.05 (m, 4H, CH 2 CH 2 ), 4.10 (br s, 2H, 3-NH 2 , D 2 O exchangeable), 5.76 (s, 1H, 2-CH), 6.92 (d, 1H, 5-H, J 5 ,6 =4.5 Hz), 7.86 (d, 1H, 6-H, J 5 ,6 =4.5 Hz). Anal. (C 9 H 12 N 2 O 2 ) C, H, N.
EXAMPLE LII
2-(1,3-Dioxolanyl)-4-methyl-5-aminopyridine was synthesized by methodology used for Example LI except that the starting material was 2-(1,3-dioxolanyl)-4-methyl-5-nitropyridine. Yield: 1.2 g (92%); mp 79°-80° C.; 1 H NMR (90 MHz, CDCl 3 ) δ 2.15 (s, 3H, 4-CH 3 ), 3.70 (br s, 2H, 5-NH 2 , D 2 O exchangeable), 4.10 (m, 4H, CH 2 CH 2 ), 5.70 (s, 1H, 2-CH), 7.15 (s, 1H, 3-H), 8.00 (s, 1H, 6-H). Anal. (C 9 H 12 N 2 O 2 ) C, H, N.
The following examples show the usefulness of the compounds of the second aspect of the invention:
EXAMPLES LIII-LVI
This set of experiments contrasts the use of the compounds 3- and 5-hydroxy-2-formylpyridine thiosemicarbazone with the compounds of the invention which are the corresponding 4-methyl-substituted compounds. Examples LIII and LIV are reference examples, while Examples LV and LVI represent compounds of the invention. In each of these examples, DMSO is used for solubilization.
Example LIII
3-Hydroxy-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in DMSO solution as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average percentage change in body weight from onset to termination of the therapy was +1.5. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 114.
Example LIV
5-Hydroxy-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in DMSO solution as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average percentage change in body weight from onset to termination of the therapy was +1.8. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 132.
Example LV
3-Hydroxy-4-methyl-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in DMSO solution as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average percentage change in body weight from onset to termination of the therapy was +0.5. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 135.
Example LVI
5-Hydroxy-4-methyl-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in DMSO solution as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average percentage change in body weight from onset to termination of the therapy was -7.4. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 138.
EXAMPLES LVII-LIX
Example LVII
5-Hydroxy-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in suspension as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 60 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average percentage change in body weight from onset to termination of the therapy was +4.6. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 146.
Example LVIII
3-Hydroxy-4-methyl-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in a suspension as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 50 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average percentage change in body weight from onset to termination of the therapy was +0.9. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 168.
Example LIX
5-Hydroxy-4-methyl-2-formylpyridine thiosemicarbazone was administered to mice bearing the L1210 leukemia by intraperitoneal injection in a suspension as the injection form, beginning 24 hours after tumor implantation, with the optimum daily dosage being 40 mg/kg. Administration was once per day for a total of six consecutive days to a representative sample population. At least five mice were tested at each dosage level. The average change in body weight from onset to termination of the therapy was -3.4. A value T/C×100 is calculated, which is the ratio of the survival time of treated to control animals×100, and has a value of 186. | A method of treatment of tumors is provided based upon a compound of the formula ##STR1##
Some aspects of the invention were supported in part by U.S. Public Health Service Grant CA-02817 from the National Cancer Institute and support from the Northeast NMR Facility at Yale University insofar as the use of high resolution NMR spectra is concerned that was made possible by a grant from the Chemical Division of the National Science Foundation (Grant No. CHE-7916210). | 2 |
TECHNICAL FIELD
The present application relates generally to digital to analog conversion and, more specifically, to a system and method for cyclic digital-to-analog conversion for use with large sized liquid crystal displays.
BACKGROUND
Digital-to-analog converter (DAC) circuitry converts digital signals into analog signals for use by additional circuitry. Many devices can include DAC circuitry such as video components. Video signals from a digital source, such as a computer, are converted to analog form if they are to be displayed on an analog monitor. DACs are also incorporated in Liquid Crystal Display (LCD) column drivers.
Single rail LCD column drivers utilize a supply voltage (AVDD) as the main supply. Dual rail LCD column drivers may commonly use shield circuits (shields) to assure that the output transistors do not exceed a specified maximum voltage.
SUMMARY
A digital-to-analog (DAC) circuit is provided. The DAC circuit includes an upper voltage supply and a middle voltage supply. The DAC circuit also includes an upper DAC stage. The upper DAC stage includes an upper DAC switch circuit. The upper DAC switch circuit consists of a first set of transistors. A body of the first set transistors are coupled to the upper voltage supply, and a drain and source of the first set of transistors is configured to receive any voltage between the middle voltage supply and the upper voltage supply. The DAC circuit also includes a lower DAC stage. The lower DAC stage includes a lower DAC switch circuit. The lower DAC switch circuit consists of a second set of transistors. A body of the second set of transistors is coupled to a ground and a drain and source is configured to receive any voltage between the lower voltage supply and the middle voltage supply.
A digital-to-analog (DAC) circuit capable of operating over an upper range and a lower range is provided. The DAC circuit includes an upper voltage supply, a middle voltage supply, and a lower voltage node. The upper range is a first voltage between the middle voltage supply and the upper voltage supply, and the lower range is a second voltage between the lower voltage node and the middle voltage supply. The DAC circuit also includes an upper DAC stage. The upper DAC stage includes an upper DAC switch circuit. The upper DAC switch circuit consists of a first set of transistors. A body of the first set of transistors is coupled to the upper voltage supply, and a drain and source of the first set of transistors is configured to receive any voltage between the middle voltage supply and the upper voltage supply. The DAC circuit also includes a lower DAC stage. The lower DAC stage includes a lower DAC switch circuit. The lower DAC switch circuit consists of a second set of transistors. A body of the second transistor is coupled to the lower voltage node, and a drain and source of the second set of transistors is configured to receive any voltage between the lower voltage supply and the middle voltage supply.
A digital-to-analog (DAC) circuit capable of operating over an upper range and a middle range is provided. The DAC circuit includes an upper voltage supply, a middle voltage supply, a lower voltage node, and an upper DAC stage. The upper DAC stage includes an upper DAC switch circuit. The upper DAC switch circuit consists of a first set of transistors. A body of the first set transistors is coupled to the upper voltage supply, and a drain and source of the first set of transistors is configured to receive any voltage between the middle voltage supply and the upper voltage supply. The DAC circuit also includes a lower DAC stage. The lower DAC stage includes a lower DAC switch circuit. The lower DAC switch circuit consists of a second set of transistors. A body of the second set of transistors is coupled to the lower voltage node, and a drain and source of the first set of transistors is configured to receive any voltage between the lower voltage supply and the middle voltage supply. The DAC circuit also includes an upper output switch configured to switch an upper output node of the upper DAC stage to an output node when the output is in the upper range, and a lower output switch configured to switch a lower output node of the lower DAC stage to the output node when the output is in the lower range.
Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,”as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,”as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
FIG. 1 illustrates a single rail LCD driver circuit;
FIG. 2A illustrates a complementary switch structure according to embodiments of the present disclosure;
FIG. 2B illustrates a circuit architecture including complementary switches in which some of the complementary switches are shared with 2 DACs;
FIG. 3 illustrates a dual rail LCD driver circuit according to the present disclosure;
FIG. 4 illustrates complementary switch structure in upper and lower DACs according to embodiments of the present disclosure; and
FIG. 5 illustrates upper and lower DACs according to embodiments of the present disclosure.
DETAILED DESCRIPTION
FIGS. 1 through 5 , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system.
FIG. 1 illustrates a conventional single rail LCD driver circuit. The LCD driver circuit 100 includes a DAC 105 coupled between a supply voltage (hereinafter “AVDD”) 110 and ground 115 . AVDD 110 can be a sixteen volt (16V) maximum supply.
In the example shown in FIG. 1 , the DAC 105 receives Vrefs in a range from zero volts (0V) to AVDD. The DAC 105 includes one or more 16V compliance transistors. The configuration of the DAC 105 is further illustrated in greater detail in FIG. 2A , in which the DAC 10 includes switches in a complementary structure, that is, p-channel MOSFET (PMOS) transistor 205 and n-channel MOSFET (NMOS) transistor 210 switches are used together as a pair. In addition, the example shown in FIG. 2B illustrates a circuit architecture including complementary switches wherein some of the complementary switches may be shared with two DACs as described below. The internal switches 205 , 210 are in a complementary pair structure because the Vrefs can have any value between 0V and AVDD. Although not shown in FIG. 2B , the body of NMOS transistor 210 can be coupled to the ground (0V) 115 and the body of the PMOS transistor 205 can be coupled to AVDD 110 .
The DAC 105 outputs a signal (OUTDAC). The output is taken at 120 as shown. The OUTDAC signal is output from the DAC 105 to a number of switches 125 to produce switch outputs 130 . The switches 125 include one or more 16V compliance transistors in a complementary structure, that is, PMOS and NMOS switches used together as a pair. The PAD 135 has an output voltage swing between 0 and AVDD, which in this example is 16 volts.
FIG. 3 illustrates a dual rail LCD driver circuit according to the present disclosure. The embodiment of the dual rail LCD driver circuit 300 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure. In some embodiments, the LCD driver circuit 300 is configured as a LCD driver circuit disclosed in U.S. Pat. No. 7,589,653 to Guedon et al. entitled “OUTPUT ARCHITECTURE FOR LCD PANEL COLUMN DRIVER”, issued on Sep. 15, 2009, the contents of which are hereby incorporated by reference in their entirety.
The LCD driver circuit 300 includes an upper DAC (UDAC) 305 and a lower DAC (LDAC) 310 . LCD driver circuit 300 includes two supply voltages, AVDD 315 and HVDD 320 . The HVDD 320 can be an eight volt (8V) supply while the AVDD 315 can be a sixteen volt (16V) maximum supply, that is, AVDD 315 can be twice HVDD 320 .
The UDAC 305 is coupled between AVDD 315 and HVDD 320 . The LDAC 310 is coupled between HVDD 320 and ground 325 (0V). The UDAC 305 is coupled on an output to Upper switches (USwitches) 335 while LDAC 310 is coupled on an output to lower switches (LSwitches) 340 . The USwitches 335 and LSwitches 340 can be complementary MOS transistor switches. Therefore, the LCD driver circuit 300 includes an upper section and a lower section. Upper refers to an upper range which normally operates between HVDD-AVDD, and lower refers to a lower range which normally operates between 0-HVDD.
The dual rail LCD driver circuit 300 uses HVDD 320 and AVDD 315 as the main supply. The OUTUDAC 345 swings from HVDD to AVDD while the OUTLDAC 350 swings from 0V to HVDD. The PAD 355 swings from 0V to AVDD.
In some embodiments, the UDAC 305 and the LDAC 310 are manufactured using larger 16 volt compliance transistor. In this example, the OUTUDAC 345 and OUTLDAC 350 can each tolerate voltage swings from O-AVDD swing due to use of the 16V compliance transistors in the UDAC 305 and the LDAC 310 . In order to avoid turning on the intrinsic diodes of the transistors, the body of the NMOS transistors 405 and 410 in FIG. 4 are both coupled to the ground (0V) for both the upper and the lower DACs 305 , 310 while the body of the PMOS transistors 415 and 420 are coupled to the AVDD for both the upper and the lower DACs 305 , 310 .
In this embodiment, the size is potentially impacted due to the use of the larger 16 volt compliance transistors 405 - 420 . This could have impact on the body effect (becoming higher). Therefore bigger transistors are needed to achieve the same performance. The body effect and the process constraint result in comparatively large transistor size which will affect the speed performance of the DAC 305 , 310 .
In the example shown in FIG. 3 , the UDAC 305 and the LDAC 310 can be manufactured using eight volt (8V) compliance transistors and sixteen volt (16V) transistors as output switches 335 , 340 . The 16 volt compliance transistors are configured as shown in FIG. 4 . In this example, the OUTUDAC 345 can tolerate a Vref range that is an HVDD-AVDD swing and the OUTLDAC 350 can tolerate a Vref range that is an 0-HVDD swing due to use of the 8V compliance transistors in UDAC 305 and the LDAC 310 .
The single rail LCD driver 100 architecture uses only one supply voltage (AVDD 110 ). The dual rail LCD driver circuit 300 architecture makes use of two supply voltages (AVDD 315 and HVDD 320 ). The dual rail LCD driver circuit 300 provides the possibility to stack the DAC into upper and lower sections. By using an appropriate structure, the upper and lower DAC sections could utilize medium voltage compliance transistors, that is, 8V compliance, due to the smaller voltage requirement. The medium voltage compliant transistor has a smaller size and will result in fast DAC speed and smaller die area.
The area of the DAC can be a critical factor in designing a column driver. A smaller DAC area can result in a smaller die size because the number of outputs in the column driver is proportional to the number of DAC used. For example, a 420 output column driver consists of an upper DAC and a lower DAC.
FIG. 5 illustrates upper and lower DACs according to embodiments of the present disclosure. The embodiment of the upper and lower DACs shown in FIG. 5 is for illustration only. Other embodiments could be used without departing from the scope of this disclosure.
In some embodiments, to further reduce the area of the DAC, a smaller number of transistors are used in the dual rail LCD driver circuit 300 architecture. The dual rail LCD driver circuit 300 can include single type of MOS switches in the UDAC 305 and the LDAC 310 . For example, the UDAC 305 can include a single type of MOS switch (PMOS) 505 and the LDAC 310 can include a single type of MOS switch (NMOS) 510 .
The symmetric 8V transistors, in a 16V process, can sustain up to 16V between the gate/source and gate/drain. The CMOS switches in the UDAC 305 can be replaced by a single PMOS switch having a gate swinging from 0 to AVDD, and the CMOS switches in the LDAC 310 can be replaced by a single NMOS switch having a gate swinging from 0 to AVDD.
The PMOS switch 505 can be an 8V transistor with a 16V gate compliance. In addition, the drain or source voltage of the UDAC 305 can be within the HVDD-AVDD range. The NMOS switch 510 also can be an 8V transistor with a 16V gate compliance. Further, the drain or source voltage of the LDAC 310 can be within the 0-HVDD range. Therefore, the minimum Gate-Source voltage (Vgs) of the PMOS switch 505 is HVDD when it is on, which is the same as the minimum Vgs of the NMOS switch 510 .
Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. | A system for implementing a cyclic digital to analog converter (c-DAC) is capable of supporting a large size liquid crystal display. The system includes an upper DAC stage configured to output a first voltage between a lower voltage supply (HVDD) and an upper voltage supply (AVDD). The system also includes a lower DAC stage configured to output a second voltage between the lower voltage supply (HVDD) and a ground. The upper DAC stage includes a single PMOS switch and the lower DAC stage includes a single NMOS switch. | 7 |
FIELD OF THE INVENTION
The present invention relates to a method for producing L-isoleucine using a fermentation process. L-isoleucine is an amino acid which plays a nutritionally important role for both humans and animals and is used as pharmaceuticals, foods, feed additives and the like.
BACKGROUND OF THE INVENTION
Since isoleucine has four optical isomers, it is very difficult to economically produce L-isoleucine alone by chemical synthesis or by a combination of chemical synthesis and enzymatic partition. Thus, industrial production of L-isoleucine is performed mainly by a fermentation process.
As methods for producing L-isoleucine with a fermentation process, precursor addition methods are known wherein precursors for L-isoleucine such as DL-α-aminobutyric acid, α-ketobutyric acid and threonine are added to a fermentation medium or a microbial reaction system and converted into L-isoleucine (Japanese Examined Patent Publication Nos. 45347/60, 8709/68, 29789/71, etc.). However, the above-mentioned methods are not advantageous for industrial production, because they need expensive starting materials and result in low yields.
On the other hand, as direct fermentation methods wherein L-isoleucine is produced from sugar directly and accumulated in a culture broth, there are known methods which employ mutants induced from wild type strains of microorganisms belonging to the genera Corynebacterium, Brevibacterium, Escherichia, Serratia, Arthrobacter and the like. L-isoleucine producing mutants include, for example, auxotrophic strains which require amino acids or nucleic acids (Japanese Examined Patent Publication Nos. 7091/63 and 60237/89), strains having resistant mutation to amino acid analogs, vitamins and the like (Japanese Examined Patent Publication Nos. 21077/76, 62394/91, 62395/91; Japanese Unexamined Patent Publication Nos. 101582/75 and 130882/93), strains having both auxotrophic mutation and amino acid analogs-resistant mutation (Japanese Examined Patent Publication Nos. 6237/76 and 32070/79), strains having fluoropylvic acid-sensitive mutation (Japanese Examined Patent Publication No. 60236/89), strains with enhanced ability to grow utilizing L-aspartic acid as the sole nitrogen source (Japanese Examined Patent Publication No. 56596/92), or strains having a mutation of decreased substrate affinity in aminoacyl t-RNA synthase (Japanese Unexamined Patent Publication No. 330275/92). Furthermore, transformants produced by using recombinant DNAs including those genes involved in the biosynthesis of isoleucine or threonine are also known (Japanese Unexamined Patent Publication Nos. 893/83, 12995/85, 30693/85, 195695/86, 458/90, and 42988/90).
SUMMARY OF THE INVENTION
Recently, a demand for L-isoleucine for use in pharmaceuticals, foods, feeds, and so forth is increasing. Therefore, it is strongly desired to improve methods for producing L-isoleucine. Accordingly, it is an object of the present invention to provide an industrially efficient method for producing L-isoleucine which is useful as pharmaceuticals, foods or feed additives.
Microorganisms belonging to the genus Esherichia can not grow or grow very poorly in a medium containing L-homoserine as the sole nitrogen source. To date, there has not been known a method for producing L-isoleucine by using a microorganism belonging to the genus Escherichia which has acquired an ability to grow rapidly in the above-mentioned medium.
The present invention can provide a method for producing L-isoleucine comprising culturing in a nutrient medium a microorganism belonging to the genus Escherichia which is capable of growing rapidly in a medium containing L-homoserine as the sole nitrogen source and has an ability to produce L-isoleucine in the medium, producing and accumulating L-isoleucine in the culture, and recovering L-isoleucine therefrom.
Furthermore, the present invention provides a microorganism belonging to the genus Escherichia which is capable of growing rapidly in a medium containing L-homoserine as the sole nitrogen source and producing L-isoleucine in the medium.
DETAILED DESCRIPTION OF THE INVENTION
Hereinbelow, the present invention will be described in detail.
As the microorganism of the present invention, any microorganism may be used so long as it belongs to the genus Escherichia and can grow in a medium containing L-homoserine as the sole nitrogen source. Concretely, such a microorganism belonging to the genus Escherichia may be used which can form colonies more than 0.6 mm in diameter on the L-homoserine minimum agar plate medium described below when cultured at 30° to 35° C. for 3 to 7 days. The above-mentioned "L-homoserine minimum agar plate medium" is obtained by adding agar to a modified minimal medium (hereinafter referred to as "L-homoserine minimum medium") in which the nitrogen sources have been replaced with L-homoserine and which contains L-homoserine as the sole nitrogen source at a concentration of 0.01-0.1%. Examples of such microorganisms include Escherichia coli H-9146 and H-9156.
The L-Isoleucine producing strain of the present invention may be selected from those microorganisms which grow more rapidly than parent strains on the L-homoserine minimum agar plate medium. Microorganisms having such properties may be obtained by using known mutagenizing treatments, cell fusion, transduction, or other gene recombination techniques. In addition, those microorganisms may also have other properties to improve L-isoleucine productivity, such as auxotrophy, drug resistance, and drug sensitivity.
The production of L-isoleucine using the microorganism of the present invention may be carried out by conventional methods for bacterial culture.
As the medium used, any synthetic or natural medium may be used so long as it appropriately contains carbon sources, nitrogen sources, inorganic compounds, and traces amount of other nutrients required for the strain used.
As the carbon source, carbohydrates such as glucose, fructose, sucrose, lactose, molasses, cellulose hydrolysates, crude sugar hydrolysates, starch hydrolysates; organic acids such as pyruvic acid, acetic acid, fumaric acid, malic acid, and lactic acid; and alcohols such as glycerol, propanol and ethanol may be used.
As the nitrogen source, ammonia, ammonium salts of various inorganic acids and organic acids such as ammonium chloride, ammonium sulfate, ammonium acetate, and ammonium phosphate; other nitrogen-containing compounds; amines, peptone, meat extract, yeast extracts, trypton, corn steep liquor, casein hydrolysates, soybean cakes, soybean cake hydrolysates, various cultured cells of microorganisms, their digested products, etc. may be used.
As the inorganic compounds, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, magnesium hydrogen phosphate, magnesium sulfate, magnesium chloride, sodium chloride, ferrous sulfate, manganese sulfate, copper sulfate, calcium chloride, calcium carbonate, etc. may be used.
The microorganism of the invention is cultivated under aerobic conditions by shaking culture, submerged-aerial stirring culture or the like at 20° to 40° C., preferably 28° to 37° C. The pH of the medium ranges from 5 to 9. Preferably, it is maintained almost neutral. The adjustment of pH is carried out with calcium carbonate, inorganic or organic acids, alkaline solutions, ammonia, pH buffering solution, etc. usually, L-isoleucine is produced and accumulated in the culture by 1 to 7 day culture.
After the completion of the cultivation, precipitates such as cells are removed from the culture by centrifugation, etc. By using a combination of ion exchange treatment, concentration, salting out or the like, L-isoleucine can be recovered from the supernatant.
According to the present invention, L-isoleucine is efficiently produced industrially.
PREFERRED EMBODIMENTS OF THE INVENTION
The present invention will be described below in more detail with reference to the following Examples 1-3.
EXAMPLE 1
Acquisition of L-isoleucine producing mutants capable of rapidly growing in the L-homoserine minimum medium
L-isoleucine producing mutants capable of rapidly growing in the L-homoserine minimum medium were induced from 2 parent strains. Briefly, as the parent strains, the amino acid non-producing strain Escherichia coli ATCC 11105 J. Bacteriol., 60, 17(1950)! which has not received any mutagenizing treatment to improve its amino acid productivity and does not produce a detectable amount of amino acids in the culture and the L-isoleucine producing strain Escherichia coli H-8683(FERM BP-4052) were used.
According to known methods, both ATCC 11105 and H-8683 strains were treated with N-methyl-N'-nitro-N-nitrosoguanidine (0.5 mg/ml) as a mutagen at 33° C. for 30 minutes. Then, the treated strains were spread on the L-homoserine minimum agar plate medium (pH 7.2)(0.5% glucose, 0.02% L-homoserine, 0.3% potassium dihydrogen phosphate, 0.6% disodium hydrogen phosphate, 0.01% magnesium sulfate, 20 mg/liter calcium chloride, and 2% agar) supplemented with 20 mg/liter DL-methionine which is an auxotrophic amino acid. The cells were incubated at 33° C. for 4 to 7 days, and large colonies grown were separated as mutants which acquired an ability to grow rapidly in a medium containing L-homoserine as the sole nitrogen source.
Those mutants induced from ATCC 11105 were subjected to an L-isoleucine production test which was conducted according to the bioassay described below. In seven strains out of the one hundred mutants tested, a circular growth zone (halo)(which was formed by the growth of CGSC3516 strain and which shows the production of L-isoleucine) was observed. Among such halo forming mutants, the mutant which formed the largest halo was selected, and designated as Escherichia coli H-9146.
L-isoleucine production test by bioassay
The L-isoleucine auxotroph, Escherichia coli CGSC3516(ilvE316, trp-3, his-4, thi-1) J. Bacteriol., 98, 1179(1969)! is cultured in a natural medium (pH 7.2) (1% trypton, 0.5% yeast extract, 1% NaCl) for 24 hr. The cells are centrifuged and then washed with saline. These operations are repeated twice. After that, the cells are mixed with an agar medium for production test (0.5% glucose, 0.2% ammonium chloride, 0.3% potassium dihydrogen phosphate, 0.6% disodium hydrogen phosphate, 0.01% magnesium sulfate, 20 mg/liter calcium chloride, 20 mg/liter L-valine, L-leucin, L-tryptophan, L-histidine and DL-methionine, 1 mg/liter thiamin chloride salt, and 2% agar) (pH 7.2) to prepare a plate medium containing CGSC3516 strain at the final concentration of 10 6 cells/ml. A strain to be tested for its L-isoleucine productivity is replicated on this plate medium, and then cultivated for 1 day at 33° C. After cultivation, the L-isoleucine productivity is evaluated based on the size of the circular growth zone formed around the test strain by CGSC3516 strain.
On the other hand, the mutant strains induced from the L-isoleucine producing strain H-8683 were subjected to an L-isoleucine production test which was conducted in a similar manner (using a thick test tube) to that described in Example 3. One hundred mutants were tested and, as a result, about 8% of the mutants showed an enhanced L-isoleucine productivity compared to the parent. Among such mutant strains, the mutant which produced the largest amount of L-isoleucine was selected and designated as Escherichia coli H-9156.
Both Escherichia coli H-9146 and H-9156 were deposited with National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Japan, as of Mar. 28, 1996, under the accession numbers FERM BP-5055 and FERM BP-5056, respectively, both in terms of the Budapest Treaty.
EXAMPLE 2
Comparative growth test on the L-homoserine minimum agar plate medium
Two mutants, H-9146 and H-9156, obtained in Example 1 and the respective parent strains, ATCC 11105 and H-8633, were subjected to a competitive growth test on (20 mg/liter methionine containing) L-homoserine minimum agar plate medium described in Example 1, the medium containing L-homoserine as the sole nitrogen source. Each of these four strains was cultivated for 24 hr on the natural medium. After that, each strain was suspended in physiological saline. The cell suspension was spread on the agar plate medium at the concentration of 1 to 10 cells/cm 2 , and incubated at 33° C. for 5 days. Then, the growth of each strain was compared based on the sizes of colonies formed. Results are shown in Table 1.
Both parent strains, ATCC 11105 and H-8683, grew very poorly on the above-mentioned L-homoserine minimum agar plate medium containing L-homoserine as the sole nitrogen source, and only formed colonies smaller than 0.5 mm in size. However, both H-9146 and H-9156 could form clear colonies larger than 1 mm in size on the same agar plate medium. These results demonstrate that the both mutant strains, H-9146 and H-9156, have acquired ability to grow rapidly utilizing L-homoserine as the sole nitrogen source.
TABLE 1______________________________________ Nitrogen sourceStrain None L-homoserine (0.02%)______________________________________ATCC 11105 - ±H-9146 - ++H-8683 - ±H-9156 - +______________________________________ ++; very good growth, colony size ≧ 3 mm +; good growth, 1 mm ≦ colony size ≦ 3 mm ±; poor growth, colony size ≦ 0.5 mm -; no growth, no colony formation
EXAMPLE 3
L-isoleucine Production Test
An L-isoleucine production test was performed on the two mutants, H-9146 and H-9156, both obtained in Example 1, and their parent strains, ATCC 11105 and H-8683, as follows.
Each of these 4 strains were inoculated into a thick test tube containing 6 ml of a seed culture medium (2% glucose, 1% peptone, 1% yeast extract, 0.25% NaCl, 130 mg/liter DL-methionine, and 1% calcium carbonate) (pH 7.0), and cultivated with shaking at 30° C. for 16 hr. One tenth milliliter of each seed culture broth was inoculated into 5 ml of a production medium (6% glucose, 0.2% corn steep liquor, 1.6% ammonium sulfate, 0.1% potassium dihydrogen phosphate, 100 mg/liter DL-methionine, 4% magnesium phosphate, and 1% calcium carbonate) (pH 7.0) and then cultivated at 30° C. for 48 hr with shaking. After that, the amount of L-isoleucine accumulated in the culture was determined by HPLC.
Results are shown in Table 2. The mutant H-9146 induced from the amino acid non-producing strain ATCC 11105 showed that it acquired an ability to produce a detectable amount of L-isoleucine outside the cells in the culture broth. Another mutant H-9156 induced from the L-isoleucine producing strain H-8683 showed an enhanced L-isoleucine producing ability. H-9156 could accumulate more L-isoleucine than the parent strain by about 13%.
Consequently, it has become clear that, by using the procedures described in Example 1, a mutant having an enhanced L-isoleucine producing ability can be induced not only from an L-isoleucine producing strain but also from an amino acid non-producing strain which has received no mutagenizing treatment to improve its amino acid productivity.
TABLE 2______________________________________Strain L-isoleucine (g/liter)______________________________________ATCC 11105 0H-9146 0.5H-8683 13.4H-9156 15.1______________________________________ | The present invention provide a method for the industrial production of L-isoleucine which is useful as pharmaceuticals, foods, feed additives and the like. The method comprises cultivating in a nutrient medium a microorganism belonging to the genus Escherichia which is capable of rapidly growing in a medium containing L-homoserine as the single nitrogen source and has an ability to produce L-isoleucine in the medium, producing and accumulate L-isoleucine in a culture and recovering L-isoleucine therefrom. | 2 |
BACKGROUND OF THE INVENTION
[0001] This application is a nonprovisional application of U.S. Provisional Application No. 60/3183,48, filed Sep. 10, 2001.
[0002] The present invention relates to mining and construction cutting bits and holders, the holders being attached to a rotating cutting drum. In the past, rotatable cutting tools have been put to a number of uses, including use as a mine tool in a continuous mining machine. Typically, a continuous mining machine includes a driven rotatable drum having a plurality of support blocks affixed thereto.
[0003] The invention concerns a rotatable cutting bit, as well as the bit holder, wherein the cutting bit has a hard insert at the forward end thereof. The cutting bit rotatably mounts in the bit holder. More specifically, the invention pertains to such a rotatable cutting bit, as well as the bit holder, designed so as to exhibit a reduction in the impediment to rotation, and thereby provide for improved rotation, between the bit and the bit holder. The invention also provides for a rotatable cutting bit, as well as the bit holder, which provides for improved wear protection for the bit holder during operation.
[0004] In the prior art, such as U.S. Pat. No. 6,113,195, to Mercier et al., and U.S. Pat. No. 4,818,027, to Simon, the bit block holder is protected from wear caused by rotation of the cutter bit head and shank by a holding washer element and spring sleeve retainer respectively. In the cutter bit provided with the holding washer element, the clamping sleeve is held tightly enough that the cutter bit with the clamping sleeve can be pushed into the bore of the bit holder even manually over a great portion of its axial dimension, until, for example, the holding element abuts on the insertion side of the bit holder. The cutter bit can be driven to the shoulder of the bit head adjacent the bit holder by means of a hammer blow. By this means, the holding element is slid from the clamping sleeve, and reaches an area of the bit shank free from the clamping sleeve, so that the clamping sleeve, with the clamping force particular to it, can be tensed in the bore of the bit holder, whereby the tension force correspondingly increases with increasing drive-in depth.
[0005] In operation, the drum rotated whereby the rotatable cutting tools impacted the earth formation, such as, for example, coal, so as to cut and break up the earth formation. As can be appreciated, the earlier rotatable cutting bits operated in an environment in which small particles of the earth formation impacted by the bit, such as coal, impinged upon the cutting bit. As the length of operation increased, these contaminants or debris had the tendency to become sandwiched between the rotatable cutting bit and the bit holder. If the amount of contaminants or debris became too great, it impeded the rotation of the cutting bit. Despite prior art designs to allow free rotation, certain cutting applications such as asphalt milling and the continuous mining of coal cause tool rotation to be inhibited by fines accumulating between the mating surfaces of the tool holder and cutter tool. Once the accumulated fines become tightly packed between the tool retainer and the tool body and/or between the tool shoulder and the holder face, rotation is greatly reduced. Following reduced rotation, a wear flat will develop on the hard tip of the tool progressing down onto the steel body. After developing a wear flat, the tool rotation generally stops, whereby the remaining useful tool life is lost.
[0006] During the operation of the earlier cutting bits, the support block experienced wear due to the contact and rotation between the cutting bit and the support block, as well as the impingement of the debris from the cutting operation. In other prior art, such as U.S. Pat. Nos. 6,113,195 and 4,818,027, which incorporate a washer between the cutting bit and support block, the wear to the bit support block is reduced, however, during operation of said prior art and the holding element washer does not remain in a fixed position on the top face of the bit block. The holding washer elements in said prior art have a tendency to rotate on the top face of the bit block due to the contact between the washer and rotating cutter bit.
[0007] While the cutting bit was replaced on a periodic basis after the expiration of the useful life thereof, the support block was typically intended to be functional much longer than the cutting bit. As the bore and front face of the support block became worn, the support block lost its effectiveness due to deformation and wear of the bore and the front face thereof. In the case of the bore, it lost its initial cylindrical shape by becoming out-of-round, oversized or bell-mouthed. In the case of the front face of the support block, it lost its flatness. Each one of these conditions impeded the satisfactory rotation of the cutting bit in the support block.
[0008] In U.S. Pat. No. 5,931,542 to Britzke et al., the cutter bit assembly was designed to prevent rotation of the washer. The cutter bit assembly in Britzke et al. includes a substantially circular wear washer having a radially inwardly directed key. The wear washer key is adapted to fit within the retainer sleeve slot, thereby interlocking the retainer sleeve with the wear washer. This provided the benefit of greatly reducing wear on the top face of the bit block. This prior art design required additional cold work machining of the block and of the washer to form the key. In the field, upon insertion into the bit block, the washer key often became broken off in use or knocked out of its cooperating keyway groove so that the washer would not be fixed in position.
[0009] It is, therefore, apparent that in light of the past experience of earlier cutting bits, it would be beneficial to provide a rotatable cutting bit which has an improved ability to freely rotate during operation.
[0010] It would, therefore, be very advantageous to provide a cutting bit, which, during operation, protects the bore of the bit holder, as well as the front face of the support block, from deformation. By providing this protection, a cutting bit would help prolong the useful life of the support block, as well as help the rotation of the cutting bit.
SUMMARY OF THE INVENTION
[0011] It is an object of the invention to provide a rotatable cutting bit, and rotatable cutting bit-bit holder assembly and washer that have improved wear resistance characteristics.
[0012] It is an object of the invention to provide a rotatable cutting bit, and rotatable cutting bit-bit holder assembly, that has improved rotational characteristics between the cutter bit and top surface of the washer during operation.
[0013] An object of the present invention is to provide an efficient means for protecting holding support blocks, of the type used to hold cutting bits used in pulverizer and rotary drum or wheel machines, from excessive abrasion and impact damage. It is believed that the relative rotation between the rear face of the washer and front of the block face is reduced in the present invention.
[0014] The improved wear resistance properties of the invention reduce the amount of necessary maintenance of rotary drums in the field, resulting in reduced downtime and increased productivity. The invention is also simple to manufacture in a cost effective manner and easy to assemble in the field.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 illustrates a side view of a first embodiment of a cutting bit having a holding washer having ridges and recesses, the holding washer maintains the clamping sleeve in a loaded state with a smaller diameter than the bore in the bit holder block.
[0016] [0016]FIG. 2 illustrates a side view of a second cutting bit assembly embodiment having a holding washer having ridges and recesses inserted into its operating position in a bit holder block wherein the holding washer abuts against the top face of the block and has released the clamping sleeve which is now loaded against the bore of the bit block.
[0017] [0017]FIG. 3 is a bottom perspective view of the holding washer of the first embodiment shown in FIG. 1.
[0018] [0018]FIG. 4 illustrates a top view of the first embodiment of a holding washer illustrated in FIG. 3.
[0019] [0019]FIG. 5 is a cross sectional view along lines 5 - 5 of FIG. 4.
[0020] [0020]FIG. 6 illustrates a side view of the second embodiment illustrated in FIG. 2, wherein the holding washer is maintaining the clamping sleeve in a loaded state prior to insertion into the block with a smaller diameter than the bore in the bit holder block.
[0021] [0021]FIG. 7 is a perspective view of the holding washer of the second embodiment illustrated in FIGS. 2 and 6.
[0022] [0022]FIG. 8 illustrates a top view of the holding washer in the second embodiment.
[0023] [0023]FIG. 9 is a cross sectional view along lines 9 - 9 of FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In the embodiment shown in FIG. 1, bit shank 14 projects from bit head 11 . The transition between the bit head 11 and bit shank 14 is constructed as collar 12 , which forms the greatest external diameter of bit head 11 . The hard metal insert 8 is inserted into the bit tip in the known manner. The clamping sleeve 17 provided with the longitudinal slot 18 rests in circumferential groove on the bit shank 14 . Clamping sleeve 17 extends over the greatest portion of the axial dimension of bit shank 14 . Stop tabs 16 (in phantom lines) project radially inward for cooperation with a recessed annular groove 15 . The bottom end of the tabs abut against an annular surface of the groove that extends perpendicular to the longitudinal axis of the shank as well-known in the art. A holding washer element 19 is slid onto clamping sleeve 17 . The washer compresses the clamping sleeve 17 to such an extent that its external diameter is equal to or smaller than the diameter of bore 21 in bit holder 20 . Longitudinal slot 18 is wide enough so that clamping sleeve 17 can be pressed together far enough that its internal wall lies on bit shank 14 . Since bore 21 of bit holder 20 is provided with diverging frustoconical opening 22 , the bit shank 14 of cutter bit 10 can be easily inserted into bore 21 . This insertion process can be carried out manually, until holding element 19 strikes the frontal side of the bit holder 20 . Then with increased application of force, for example, by means of a blow from a hammer, the cutter bit 10 can be driven far enough into bore 21 so that collar 12 of bit head 11 , by means of the holding element 19 , is driven to face against the frontal side of bit holder 20 as illustrated in FIG. 2 (second embodiment). In this manner, holding element 19 formed as a holding washer is moved from clamping sleeve 17 down onto the free area 13 of the bit shank 14 between clamping sleeve 17 and the bit head 11 , so that it releases clamping sleeve 17 . Clamping sleeve 17 can now be tensed with the tensing force specific to it, in the bore 21 of bit holder 20 , since it would accommodate, in the unstressed condition, an external diameter which is greater than the diameter of bore 21 of bit holder 20 . The difference between both diameter values determines the tensing force of sleeve 17 , and thereby the force with which the cutter bit 10 is held in bore 21 of bit holder 20 .
[0025] In the embodiment in accordance with FIG. 1, the external diameter of the holding washer corresponds to the maximum external diameter of bit head 11 in the area of collar 12 . The holding washer thereby serves as a protective washer for bit holder 20 , since it cushions the impact forces acting on cutter bit 10 and prevents abrasion and wear of the bit block caused by the cutter bit bearing down upon the bit block as it rotates during operation. If the external diameter of the holding washer is expanded over the maximum external diameter of the bit head 11 , then the entire frontal side of the bit holder 20 is protected against wear, if the holding washer is made of wear-resistant material.
[0026] [0026]FIG. 5 illustrate a cross-sectional view of the holding washer in which each of the front and rear main surfaces 44 , 48 extends from the outer peripheral surface 50 to the inner peripheral surface of the central opening 52 which defines the center hole of the washer. The front main surface 44 is a generally flat shape and has a plurality of evenly spaced arcuate ridge segments 55 . Front face 44 also includes a bevel 56 (e.g., a bevel of 40-50 degrees.) at the intersection with the inner peripheral surface 52 that defines the central opening in the washer. Rear surface 48 is also generally flat and has a plurality of evenly spaced recesses 53 as best seen in FIG. 3. For the purpose of this invention it is not necessary that the rear surface is beveled at 60 or that the front face is beveled 56 .
[0027] Similar to FIG. 2, the holding washer of the first embodiment of FIG. 1 in its operating position is located between the cutting bit shoulder 12 and top face 23 of the bit block. The bottom face 9 of the cutter bit rests upon the top face of the ridges 55 . The top faces of the ridges form a bearing surface about which the cutter bit rotates. In the prior art the bottom horizontal surface 9 of the cutter bit abuts against a horizontal front surface of the washer as illustrated in FIG. 1 of U.S. Pat. No. 4,818,027. This '027 flat washer and a corresponding flat surface of the cutter bit shoulder cooperate to form a large contact area at a significant distance from the cutter bits axis of rotation. With the washer of the invention, only the top surfaces of the ridges 55 contact the bottom flat surface 9 of the cutter bit shoulder. This bearing surface contact between the holding washer and cutter bit bottom reduces torsion friction that inhibits relative rotation between the cutter bit and washer in comparison to a flat washer of the same size.
[0028] In prior art designs of rotating cutter bits, in some cutting applications such as asphalt milling and the continuous mining of coal, cause tool rotation to be inhibited by fines accumulating between the mating surfaces of the tool holder and cutter tool. It is believed the flat section gaps 57 between ridges 55 permit for uninhibited flow of fines and cut particles so as to help reduce accumulation of the fines in some milling and coal operation environments in which accumulation of fines and debris sandwiched between the top mating surface of holder washers and bottom mating surface of the cutting bit is more prevalent. The length of the gap may be varied as well as the height of the gap (i.e. ridge height) to appropriately accommodate the prevailing particle size that causes accumulation problems in certain mining and construction environments. In other mining and construction environments in which sandwiched accumulation of fines and debris between mating surfaces is not a problem, the gaps may not be necessary and a continuous concentric annular ridge may be constructed with smaller gaps or possibly without any gaps (not shown).
[0029] In some prior art designs, such as U.S. Pat. No. 6,113,195, which has a beveled washer, the cutter bit shoulder does not rest flatly on the holding washer element. However, in U.S. Pat. No. 6,113,195, the washer is beveled so that the rear surface of the washer does not rest flatly upon the top face of the block either, but makes minimal contact or line contact with the top face of the bit block about the circumference of the bore close to the cutter's central axis. The rear surface 48 of the invention sits flatly on a flat horizontal top face of the bit block. Hence, the radial outward surface contact between the washer and top face of the bit block is greater than such prior art designs as U.S. Pat. No. 6,113,195. This surface contact area between the washer and top face of the bit block is made at a greater distance from the central axis increasing torsion friction and resistance to relative rotation between the holding washer 19 and bit block face 23 . This reduction in rotation of the washer upon the bit block reduces undesirable wear such as countersinking.
[0030] The rear face 48 of the washer adjacent to the opening includes inner bevel portion 60 that forms an angle between 40-50 degrees with longitudinal axis. Bevel 60 will make surface contact with the holder face frustoconical opening 22 . That surface contact performs the advantage of aiding in the resistance to lateral displacement of the cutter bit 12 since it will abut the bevel 22 of the bore 21 .
[0031] [0031]FIGS. 2 and 6- 9 illustrate a second embodiment of the present invention wherein like and similar parts with the first embodiment are identified with the same numbers in the second embodiment. The holding washer element in FIGS. 2 and 6 is shown in its holding position in which the spring clamp is held in its loaded position prior to being inserted into a bit holder block. As can be seen in FIGS. 2 and 6, the tip 8 of the cutting tool is conical as opposed to the flatter cap shaped tip 8 in FIG. 1. The shape of the tip of the cutter bit should not be limited to just those disclosed in these two embodiments but could alternatively be constructed from a variety of different shapes and geometries well-known in the industry.
[0032] The front face 44 of the washer in FIG. 7 has a plurality of evenly spaced gaps 57 and ridges 55 in the general shape of a U that extends from near the opening 52 of the washer to the outer periphery 50 of the washer. The rear surface of the washer has a U-shape recess 53 corresponding in shape and size to the U-shaped ridge on the top surface. In the inventions described above and illustrated herein, the entire top surface area of all the ridges contacts the bottom face of the cutter bit head. It is contemplated, however, that in some cutting bit assemblies, near the outside diameter of the holding washer the top face of the ridges 55 extend beyond the outside diameter of the bottom surface 9 of the cutter bit head. Therefore, only the radially inward portion of each top face of the ridges 55 provides support and forms a bearing surface for the rotating cutting tool.
[0033] The rear surface 48 of the second embodiment also sits flatly on the top face of the bit block as illustrated in FIG. 2. Hence, the contact between the washer and top face of the bit block is at a greater distance from the axis of rotation of the cutter bit than some prior art designs increasing torsion friction and resistance to relative rotation between the holding washer 19 and bit block face 23 as discussed above.
[0034] The recesses 53 in the holding element washer shown in FIGS. 2 , 6 - 9 also prove to be useful in removing a cutter bit form the bit block. The recesses can be uniform depth, as best illustrated in FIG. 9, or have a tapered undercut to receive a bit removal tool as taught in U.S. Pat. No. 5,374,111, to Den Besten deceased et al., which is herein incorporated by reference in its entirety.
[0035] In a preferred embodiment, the undercuts taper upwardly from the underside surface of the flange toward the conical nose of the cutting bit. The undercuts taper upwardly at an angle of approximately 15 degrees from a line extending transversely from a longitudinal axis of the cutting bit.
[0036] The U-shaped ridges and recesses in the holding washer element disclosed in the second embodiment, FIGS. 2 , 6 - 9 , and the arcuate ridge segments and recesses in the first embodiment, FIGS. 1 , 3 - 5 , are exemplary only. The shape of the ridges and recesses on the holding washer elements should not be limited to just those disclosed in these two embodiments but could alternatively be constructed from a variety of different shapes and geometries.
[0037] The novel holding washer element 19 according to the present invention provides a very effective means for protecting the holding block 20 on which it is installed from abrasion and impact damage, thereby substantially increasing the useful life of the holding block. The holding washer 19 in the disclosed embodiments is generally ring shaped. It should be appreciated that said holding washer could instead have the general shape of a square, hexagon or other geometry. Further, it is not necessary that the holding washer 19 be employed to compress a clamping sleeve 17 . The washer can be used with other rotating cutter bits for the purpose of enhancing rotation and reducing wear to the top face of the holder block.
[0038] The embossed washers of the invention have added strength in comparison to flat washers of the prior art. It is contemplated that as a result of this added strength, the general thickness of the washer from the front face to rear face (not at ridges or recesses) can be reduced, providing for savings in material cost and shaping ease in manufacturing the embossed washer. The embossed washer invention is made from typical Spring Steel employed and well known in the industry. The embossed washer may or may not be heat-treated. A Rockwell hardness value between 43-48 can provide for satisfactory results in some environments, whereas different Rockwell hardness values of the Spring Steel are more suitable for other environments.
[0039] Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the invention as disclosed.
[0040] It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages described, the characteristics of the invention described herein are merely illustrative of the preferred embodiment. Accordingly, I do not intend that the scope of my exclusive rights and privileges in the invention be limited to details of the embodiment described. I do intend that equivalents, adaptations and modifications reasonably inferable from the invention described herein be included within the scope of the invention as disclosed. | A rotatable cutting bit, and rotatable cutting bit-bit holder assembly and washer that have increased wear resistance characteristics. The assembly incorporates a new holding washer design that has improved rotational characteristics between the cutter bit and top surface of the washer during operation. The washer includes a front face and a generally flat rear face, said front face has a plurality of ridges, said ridges each have a top face forming a bearing surface for the cutting bit to enhance rotation of the cutter bit and the flat rear face reduces rotation of said washer. The relative rotation between the rear face of the washer and front of the block face is reduced in the present invention. The improved wear resistance properties of the invention reduce the amount of necessary maintenance of rotary drums in the field resulting in reduce downtime and increase productivity. The washer is also simple to manufacture in a cost effective manner and easy to assemble in the field. | 4 |
RELATED APPLICATIONS
This application is a continuing application based upon co-pending application Ser. No. 916,613, filed June 19, 1978, Gordon Hine and Robert D. Mathis applicants, now U.S. Pat. No. 4,249,323; and having also the title hereinbelow.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an improved material handling or treating plow blade and mounting structure therefor that are attachable to a tractor, snow grooming vehicle, and similar self-propelled vehicles. The plow blade may be a scraper blade, a snow plow blade, or other plow blade for which, in operation, there is required adjustability in the height of the blade above the terrain, and adjustability, also, in the cutting angle or angle of attack of the blade in three dimensions, that is along three separate pivotal axes each of which is spaced 90° from the others.
2. Description of the Prior Art
Different forms of mounting structures for material handling or treating plow blades have been proposed in the prior art for providing height and three dimensional blade adjustability. One form disclosed in U.S. Pat. No. 3,157,099, granted Nov. 17, 1964, utilizes a C-frame pivotally mounted on a tractor and a two-section plow blade, a three-section plow blade being suggested but neither illustrated nor otherwise described, attached at a vertically hinged connection of the blade sections by a pivot pin or pintle to the C-frame, the pintle extending centrally and longitudinally of the tractor. The main thrust of the load on the plow blade is concentrated on the pintle connection to the C-frame. Therefore, in order to provide the essential strength the C-frame necessarily must be massive and heavy. As a result, the mounting structure is costly to manufacture and difficult to assemble. Moreover, special hydraulically actuated rams are needed to support and adjust the ends of the plow blade sections, further adding undesirably to the difficulty and cost of manufacture and assembly.
Another form of mounting structure for a material treating plow blade is disclosed in U.S. Pat. No. 3,822,751, granted July 9, 1974. The structure there shown provides, for a single section plow blade, adjustability in height and cutting angle in three planes, and comprises an assembly of five different frames that are pivotally connected to each other, the connection of the second and third frames to each other being by a single centrally located vertically disposed pivot carried at the vertex of a triangular portion of the second frame. The first frame is attached to a tractor and the fifth frame to the plow blade. Here, too, the main thrust of the load on the plow blade is concentrated on a single pivot, the vertically-disposed pivot connection between the second and third frames. This requires those frame, particularly, to be massive and heavy, adding further to the difficulty and cost of manufacture and assembly of a complex assortment of frames.
While the mounting structures of U.S. Pat. Nos. 3,157,099 and 3,822,751 both provide for height and three dimensional adjustability of the plow blade, the structures are such that adjustment of the blade height, in each case, undesirably alters the pitch or roll angle of the blade. Accordingly, a compensating pitch angle adjustment is required whenever the height of the blade is changed if the optimum pitch angle for the resistance characteristics of the material being handled or treated is to be maintained.
Three-section forms of plow blades for attachment to a tractor are disclosed in U.S. Pat. Nos. 3,477,151, granted Nov. 11, 1969 and 4,019,268, granted Apr. 26, 1977. Specifically, U.S. Pat. No. 3,477,151 shows a snow plow comprising a center or primary blade and two wings or flanking auxiliary blades, each pivotally connected about an upright or vertical axis at an associated end of the center blade, the manner of attachment of the snowplow to a self-propelled vehicle not being shown. The wing blades are connected for simultaneous limited inverse pivotal movement with respect to the center blade, from relative positions wherein one wing blade is aligned with the center blade when the other is at an angle rearward of less than 180° therewith. Forward pivotal movement of the wing blades with respect to the center blade is not permitted.
U.S. Pat. No. 4,019,268 shows a three-section plow blade for snow compacting equipment in which the blade is pivotally secured to a vehicle by first and second frames parallel to the blade and by a pair of third frames that extend normal to the second frame. The three-section blade includes a center blade and two wing blades, each pivotally connected to an associated end of the center blade. The pivotal connections are horizontal whereby the wing blades, when actuated relatively to the center blade, pivot upwardly. This facilitates transportation of the equipment to and from ski trails and for storage when not in use. The structure does not provide for either downward, rearward or forward pivotal movement of the wing blades with respect to the center blade.
Accordingly, there still exists a need for improvements in the mounting structures or assemblies for plow blades, particularly in respect to an arrangement for a plow blade having variably adjustable wings: (a) that simplifies the construction and reduces the size and weight of the components while maintaining the essential structural strength, reduces the number of component parts and their manufacturing and assembly cost; (b) wherein the height adjustment of the plow blade is substantially independent of the cutting angle adjustments thereof, and in particular, the pitch or roll angle adjustment, and (c) wherein the adjustable wings of the plow blade have greater freedom of movement independently of each other, including forward as well as rearward pivotal movement with respect to the center blade.
SUMMARY OF THE INVENTION
Among the objects of the invention is the provision of a variable wing plow blade and mounting structure therefor for attachment to tractors and similar self-propelled vehicles that avoids the problems and limitations of the prior art plow blades and mounting structures.
Another object of the invention is to provide such a variable wing plow blade and mounting structure therefor that is less expensive to manufacture and to assemble.
Another object of the invention is to provide an improved and simplified mounting structure for a variable wing plow blade wherein the load on the blade is distributed over a substantial area of the supporting components of the mounting structure whereby the size and weight of the components may be reduced while maintaining rigidity and structural strength, and wherein more strength is provided where the structure mounts to the vehicle chassis.
A further object of the invention is to provide such an improved mounting structure for a variable wing plow blade that provides a plurality of independent adjustments of the blade in three dimensions, including a height adjustment of the blade that is substantially independent of and does not adversely affect any of the other adjustments.
Still another object of the invention is to provide such an improved mounting structure for a variable wing plow blade that provides freedom of movement of the wing blades, selectively and independently of each other, both forwardly and rearwardly of the center blade.
Another object of the invention is to provide such an improved mounting structure for a variable wing plow blade that includes a plurality of control means, and particularly, hydraulic motor means, thereby to enable the vehicle operator to make the various plow blade adjustments from a readily accessible control panel in the cab.
Yet another object of the invention is to provide such an improved mounting structure for a variable wing plow blade wherein the hydraulic motor means includes relief valve means to prevent damage to the plow blade in the event either wing hits an immovable object.
In accomplishing these and other objectives of the invention, there is provided a mounting structure or assembly for attaching a plow blade having a center blade and variably adjustable wing blades to a vehicle such as a tractor, snow grooming vehicle, or the like. The mounting structure includes a first horizontally positioned rectangular mount frame that is pivotally attached at one end by a pivot mount to the vehicle. The mount frame extends forwardly of the vehicle from a position adjacent the front axle thereof. The mounting structure further includes a second horizontally positioned rectangular push frame that is rigidly attached at the rearward end thereof to the forward end of the first frame. For convenience hereinafter the first and second frames are designated first frame means. The forward end of the first frame means is pivotally attached by first connecting means to a second frame means, a generally vertically positioned rectangular mounting frame, at a position adjacent the lower edge of the latter. The second frame means includes a pair of spaced vertically extending members and a lower horizontal cross member on which three spaced vertical posts are mounted. The cross member and posts are positioned in a plane that is forward of the general vertical plane of the second frame means. The center blade of the plow is attached to the cross member by means designated second connecting means and to the posts by third connecting means. The cross member and posts provide support for the center blade of the plow over a substantial portion of the rear surface thereof, the third connecting means restraining movement therebetween except for limited relative tilting of the center blade about a pivotal axis provided by said second connecting means.
The mounting structure according to the invention further includes control means, specifically hydraulic motor means, so connected between the vehicle and the several frame means and between certain members of the frame means as to effect various adjustments of the plow blade in each of three dimensions, that is, along three separate pivotal axes that are spaced 90° apart, for convenience designated coordinate X, Y and Z axes. Each such adjustment is independent of the others including an adjustment of the height of the plow blade with respect to the vehicle and the terrain. One such pair of hydraulic cylinders is connected between the vehicle and the second frame means. These hydraulic cylinders, when actuated, raise or lower the forward end of the second frame means and thereby adjust the height of the plow blade about a horizontal transverse axis provided by the pivot mounts at the rear of the first frame means. The effective lever arm involved in making this adjustment is the combined length of the first and second frame means.
Another pair of hydraulic cylinders connected between the vehicle and the vertically extending members of the second frame means, when actuated, tip the second frame means and thereby the plow blade, backward or forward. This provides a pitch or roll adjustment of the plow blade. The pivotal axis of this adjustment is a horizontal transverse axis, for example, a Z--Z axis, located at the forward end of the first frame means. The invention features the use of extension arms in association with this pair of hydraulic cylinders of such length and so positioned that each extension arm and the lever arm for raising or lowering the plow blade effectively comprise opposite arms of a parallelogram. Consequently, as those skilled in the art will understand, adjustment of the height of the plow blade is substantially independent of and does not adversely affect the pitch or roll adjustment of the plow blade.
A hydraulic cylinder connected between a sideward extending pivot arm or tongue on the second frame means and the plow blade center section, when actuated, tilts the center blade of the plow relatively to the second frame means about the axis of the pivot connection of these components, for example, a Y--Y axis, thereby to raise or lower the ends of the plow blade.
A pair of hydraulic cylinders connected between rearwardly extending pivot arms or tongues on the plow center blade and on each of the wing blades, when actuated, horizontally adjust the cutting angle of the wing blades with respect to the center blade, such adjustment of the wing blades being about a generally vertical hinge pivot connection of each wing blade to a respective end of the center blade, and being either forward or rearward with respect to the center blade. Each such adjustment is about an X--X axis and is selectively independent of the other.
The various hydraulic cylinders are actuatable from a readily accessible control panel provided in the cab of the vehicle. Additionally, relief valve means are provided in accordance with the invention to release the pressure in the hydraulic cylinders to prevent damage to the plow blade in the event either adjustable wing hits an immovable object thereby to prevent damage to the plow blade.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention may be had from the following detailed description when read in connection with the accompanying drawings wherein:
FIG. 1 is a side elevation of the mounting structure or assembly of the variable wing plow blade of the present invention, taken along the line 1--1 of FIG. 2 with a forward portion of a tractor added in dot-dash lines;
FIG. 2 is a top plan view of the mounting assembly and plow blade structural arrangement of FIG. 1 showing certain portions in cross section;
FIG. 3 is an exploded perspective view of the mounting assembly frame and plow blade arrangement of FIGS. 1 and 2, with the variable wing blade sections omitted;
FIG. 4 is a rear elevation of the second frame means of the mounting assembly;
FIG. 5 is a bottom plan view of the center blade section of the variable wing plow blade;
FIG. 6 is a diagrammatic rear view of the plow blade center section;
FIG. 7 is a diagrammatic end view of the plow blade center section as seen from the left in FIG. 6;
FIG. 8 is a diagrammatic bottom plan view of the right-hand wing blade section of the variable wing plow blade of FIG. 2;
FIG. 9 is a diagrammatic rear view of the right-hand wing blade section of the variable wing plow blade of FIG. 2;
FIG. 10 is a diagrammatic end view of the right-hand wing blade section, as seen from the right in FIG. 8;
FIGS. 11 through 15 are schematic representations of the variable wing plow blade of the present invention, the several views illustrating typical controlled positions to which the wing blade sections may be moved with respect to the center blade section; and
FIG. 16 is a partial schematic piping diagram, including relief valve means, for controlling hydraulic motor means provided for actuating the wing blades of the variable wing plow blade.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 to 3 of the drawings, the mounting structure or assembly, indicated generally by reference numeral 10, comprises a frame 12, a frame 14, and a second frame means 16. The frames 12 and 14, collectively designated first frame means a unitary frame, and frame 16, designated a second frame means or mounting frame, are all rectangular in configuration and are formed of generally square tubular members. The first frame means 12, 14 are supported, in a manner to be described, in generally horizontal positions, the second frame means 16 being pivotally connected by first connecting means in a generally vertical position to the forward end of the first frame means 12, 14.
The first frame 12, includes side by side frame members 18 and 20 that are connected together at one end, the end facing toward the rear of the vehicle to which the assembly 10 is to be attached, by a cross or transverse member 22. Outboard of and connected to the side frame members 18 and 20 and cross member 22 are additional wedge shaped side frame members 24 and 26 that extend rearwardly and upwardly, slightly above cross member 22. Pivot bearings 28 and 30 are provided in the ends of side frame members 24 and 26, respectively, immediately above the cross member 22, for the pivotal attachment of the end of frame 12 to the vehicle chassis, indicated by dot-dash lines 32 in FIG. 1, by means of pivot mounts 34 and 36. Both ends of the pivot mounts 34 and 36 are bolted to the chassis 32, as by cap screws 38. The forward end of each pivot mount 34 and 36 is provided with a clevis, indicated, respectively, at 40 and 42, that cooperates with an associated bearing 28, 30 and pivot pin 43, 44 for the pivotal attachment of the side frame members 24 and 26 to the pivot mounts. This arrangement provides for movement of the first frame means 12, 14 and thereby the assembly 10, as will become apparent, about the axis of the pivot pins 43 and 44, an axis that is substantially horizontal and perpendicular to the longitudinal center line of the vehicle chassis 32.
The frame 14 includes side by side frame members 46 and 48 that are connected at one end by a cross member 50 and at the other end by a cross member 52, and that are additionally connected by diagonal members 54 and 56. Projecting forwardly of the side frame members 46 and 48, one on either side of the outboard of cross member 52, are pivot mounts 58 and 60. These pivot mounts are provided for the pivotal attachment of the frame 14 to the second frame means 16. Pivot mounts 58 and 60 each includes a forwardly extending fork shaped portion in which two vertically spaced bearings 62, 64, and 66, 68, respectively, are provided. Pivot mounts 58 and 60 are each connected to an associated clevis 70, 72 that is provided at the rear of the second frame means 16, as seen in FIG. 4, by a respective pivot pin 74 and 76. The pairs of vertically spaced bearings 62, 66 and 64, 68, respectively, provide lower and upper pivot positions for the frame means 16 to the first frame means 12, 14. Pivot mounts 58 and 60 each further includes a respective bearing 78 and 80 for the attachment of motor means to be described for lifting and lowering first frame means 12, 14 and second frame means 16 about the horizontal axis of the pivot pins 43 and 44.
The second frame means 16, as seen particularly in FIGS. 3 and 4, includes a pair of vertically spaced generally horizontal cross members 82 and 84, a pair of elongated upstanding angle end members 86 and 88, and three intermediately located upstanding posts 90, 92 and 94, the horizontal members 82 and 84 being connected at their ends by the upstanding end members 86 and 88. Members 86 and 88 each have the form of a right angle and are inversely positioned with respect to each of members 82 and 84 as to present a side to each of said members, an edge of member 86 being presented to one side of frame 16 and an edge of member 88 to the other side of the frame. Thus, cross member 84 extends between a pair of facing sides of members 86 and 88 and the other sides of members 86 and 88 face the rear side of cross member 82, each such side being adjacent an associated end of member 82.
Each of the spaced posts 90, 92 and 94 is positioned on the upper surface of cross member 82, being rigidly connected thereto, and extends vertically for a distance such that the rear top edge of each post is adjacent the lower forward edge of cross member 84, being connected together, as by welding. The posts 90, 92 and 94 are each provided with an individual curved slot, indicated respectively at 96, 98 and 100, and the center of curvature of which is a pivot 102 provided at the center of and extending through the cross member 82 substantially parallel to a longitudinal center line of the vehicle chassis 32.
As seen in FIG. 3, particularly, pivot bearings 104 and 106 are provided at the extreme upper ends of arms 86 and 88, respectfully. Further, a pivot arm or tongue 108 is provided at the right end of cross member 82, the pivot arm in effect comprising an extension of member 82. The pivot bearings 104 and 106 and the pivot arm 108 comprise motor means connections for providing pitch angle and tilt angle adjustments of the variable wing plow blade in a manner to be described.
The variable wing plow blade, indicated generally by reference numeral 110, includes an elongated center blade or section 112, a right wing blade or section 114 and a left wing blade or section 116. The wing blades 114 and 116 are hinged on substantially vertical pivots to the right and left ends, respectively, of the center blade or section 112, in a manner to be described, for angular movement in a horizontal plane in both directions from a position of alignment with the center blade 112.
The plow blade center section 112, as illustrated in detail in FIGS. 5, 6 and 7, is comprised of a blade 118 having at its lower front or material engaging edge an elongated protective angle iron or wear bar 120 which may include a snow blade tooth 121, as indicated. The blade 118 is supported at the lower rear side thereof by a generally rectangular elongated tube 122 the ends of which are closed by plates 124 and 126. Supported on the upper surface of tube 122, at the left and right ends, respectively, as seen in FIG. 6, are upstanding U-shaped frame members 128 and 130. The tube 122 additionally supports on its upper surface, intermediate the ends thereof, three upstanding spaced U-shaped members 132, 134 and 136, the size and spacing of which may be substantially the same as that of the upstanding posts 90, 92 and 94 of the push frame 16.
The plow blade center section 112 further includes on its rear side, at the left and right ends thereof, as seen in FIG. 6, upper and lower sets of spaced rectangular hinge pads 138, 140 and 142, 144, and wedge shaped pivot mounts or tongues 146 and 148. Specifically, the upper sets of hinge pads 138 and 142 are attached to the outboard side of the respectively associated upstanding member 128 and 130, and the lower sets of hinge pads 140 and 144 are attached to the outboard side of the respectively associated elongated tube end plate 124 and 126. Pivot mounts 146 and 148 are attached, one adjacent each side of center section 112, to the rear side of an associated U-shaped member 128 and 130, each extending at an outward angle to the rear.
At the upper end of the U-shaped member 128, as seen particularly in FIGS. 5 and 6, there is provided an additional U-shaped member 150 that extends to the rear from member 128 and includes, centrally thereof, a bearing 152. The upstanding U-shaped members 132, 134 and 136 are each provided with an individual curved slot 154, 156 and 158, respectively, the curvature of the slots corresponding to that of the slots 100, 98 and 96 of the posts 94, 92 and 90 of the push frame 16. Additionally, the rectangular tube 122 is provided with a bearing 160 at a center portion thereof that is in alignment with the bearing 102 in the horizontal member 82 of the push frame when the plow center blade 118 positioned for proper support with respect to the push frame 16. With the center blade 112 so positioned, the rear surface of tube 122 abuts cross member 82, the rear surfaces of the U-shaped members 132, 134 and 136 abut the front surfaces of the posts 94, 92 and 90, and the slots 154, 156 and 158 are generally in alignment respectively, with the slots 100, 98 and 96.
As shown in FIG. 3, the plow blade center section 112 is pinned or bolted to the push frame 16 by a hex head cap screw 162 and uni-torque nut 164, a flat washer being provided, as suitable, these members, for convenience, being designated second connecting means. The plow blade center section 112 is also held to the push frame 16 by third connecting means, specifically hex head cap screws 166, 168 and 170 that extend, respectively, through the associated pairs of slots 96 and 158, 98 and 156, and 100 and 154, and respectively associated uni-torque nuts 172, 174 and 176, flat washers being provided as suitable.
In accordance with the invention the several cap screws and nuts holding the plow blade center section 112 to the push frame 16 are tightened sufficiently to hold these members snugly together thereby providing firm support for the plow blade 118 over a substantial portion of the rear surface of the center section 112, but allowing limited relative pivotal movement of the center section 112 with respect to the push frame 16 about the pivot of bearings 102 and 160. The manner in which such pivotal movement is effected is described hereinafter.
The plow blade wing sections 114 and 116 may be of identical structure but opposite hands. Hence, for purposes of illustration, there is described by reference to FIGS. 8, 9 and 10 the right wing section 114 only. The wing section 114, as shown particularly in FIG. 10, includes a blade 178, the curvature of which corresponds to that of center blade 118. At the lower front edge the blade 178 is provided with an elongated angle iron or wear bar 180 including a snow blade tooth 181. Blade 178 is supported at the lower rear side by a generally rectangular elongated tube 182 the ends of which are closed by plates 184 and 186. Provided on and supported by the upper surface of tube 182, as seen in FIGS. 8 and 9, are two upstanding U-shaped frame members 188 and 190. An upper pivot arm 192 is attached to the inboard side of U-shaped member 190 and a lower pivot arm 194 is attached to the adjacent closure plate 184. Pivot arms 192 and 194 are each provided with a respective bearing 196 and 198. Additionally, a rearwardly extending pivot arm 200 having a bearing 201 is provided on U-shaped member 188.
It will be understood that the several structural members or components of which the center blade section 112 and the wing blade sections 114 and 116 are formed may be attached to each other in any suitable manner as by welding, for example, to the end that each section in practice, is made to comprise a unitary rigid structure. When formed of materials conventional for the purpose the center blade 112 and the wing blades 114 and 116 may be made to embody the necessary and desired strength required for material treating or handling plows.
The wing blade section 114 is hinged to the right end of center blade section 112, as seen in FIG. 2, by placing the upper pivot arm 192 between the upper hinge pads 142 of the center blade section, placing the lower pivot arm 194 between the hinge pads 144, and as indicated in FIG. 6, inserting a hinge pin 202 and 204 through the respectively associated bearings.
As seen in FIG. 2, a hydraulic motor 206, comprising a cylinder and ram, has one end connected to the pivot arm 200 of the wing blade section 114 and the other end connected to the pivot arm 148 of the center blade section 112. Hydraulic motor 206 is operative when actuated to move the wing blade section 114 with respect to the center blade section 112 in a generally horizontal plane about the vertical pivotal axis provided by the hinge pins 202 and 204 from a position in which the center and wing blade sections are in alignment, as illustrated in FIG. 1, to positions in which the wing blade section 114 is moved forwardly of the center blade section 112, as shown in FIG. 13, and in which the wing blade section 114 is moved rearwardly of the center blade section 112, as shown in FIG. 15. A hydraulic motor 208 which may be identical to the motor 206 is connected in a similar manner between the left wing section 116 and the center blade section 112 for effecting forward and rearward movements of the wing blade section 114, as seen in FIG. 2, with respect to center blade section 112, from a position of alignment therewith.
FIGS. 11-15 illustrate typical ones of a wide range of positions to which each of the wing blades or sections 114 and 116 can be adjusted in a generally horizontal plane with respect to the center blade section 112, from a rear angle position to a forward angle position. Thus, with both wing blades 114 and 116 parallel to or in alignment with the center blade 112, the variable wing plow blade 110 is operative as a straight plow blade, as shown in FIG. 11. With both wing blades 114 and 116 angled forward in the direction of movement of the vehicle, as shown in FIG. 12, the variable wing plow blade 110 is operative as a conventional U-blade for pushing forward the material being handled. With wing blade 114 angled forward and wing blade 116 angled backward, as shown in FIG. 13, the variable wing plow blade 110 is operative to move the material being handled to one side of the vehicle. In this condition of adjustment, snow, for example, can be transferred from the edges to the centers of narrow trails. In order to transfer the material to be handled to the opposite side of the vehicle, the wing blades 114 and 116 may be adjusted to the positions illustrated in FIG. 14. With the wing blades 114 and 116 in the positions illustrated in FIG. 15, the variable wing plow blade 110 is operative to drag the material being handled backwards when the vehicle is moving in reverse. This latter condition of adjustment is particularly advantageous for clearing or cleaning out ditches or culverts into which it is not practical for the vehicle to enter for pushing the material out.
In accordance with the invention the hydraulic motors 206 and 208 are controlled from a central control panel preferably provided in the cab of the vehicle for easy access by the operator. Also, in accordance, with the invention, additional hydraulic motor means controlled from the same central control panel may be provided for effecting the desired tilt angle, pitch angle and height adjustments of the variable wing plow blade 110. Specifically, for varying the tilt angle, there is provided, as shown in FIG. 1, a hydraulic motor 210 having a cylinder and ram with one end connected by a clevis to the pivot arm 108 on the end of the push frame 16 and the other end connected by a clevis to the bearing 152 on the U-shaped frame 150 of the center blade section 112.
For varying the height of the variable wing plow blade 110 off the ground, there is provided two hydraulic motors 212 and 214 each having a cylinder and ram. Motor 214, as seen in FIGS. 1 and 3, has one end connected by a clevis to bearing 80 in pivot mount 60 of mount frame 14 and the other end connected by a clevis to a mounting plate 216 that is bolted in any suitable manner to the side of vehicle chassis 32. Motor 212, as best seen in FIG. 2, has one end connected to the bearing 78 in pivot mount 58 of mount frame 14 and the other end connected by a clevis to a mounting plate 218 that is bolted in any suitable manner to the side of the vehicle chassis 32 opposite that to which mounting plate 216 is attached. Upon actuation, motors 212 and 214 raise or lower frames 12, 14 and 16 as a unit and thereby the variable wing plow blade 110 about the axis of pivot arms 43 and 44 at the forward ends of the pivot mounts 34 and 36.
In order to vary the pitch angle of the plow blade there is provided a pair of hydraulic motors 220 and 222 and a pair of respectively associated extension arms 224 and 226. Each of the motors include a cylinder and ram and for added rigidity and strength is telescoped within the forward end of its associated arm. One end of the motor 222, as seen in FIGS. 1 and 2, is connected to the bearing at the upper end of upstanding member 88 of the second frame means or push frame 16 and the other end is connected by a pin indicated at 228 in the adjacent end of the extension arm 224. The other end of extension arm 226 is attached by the mounting pin 230 to an anchor pad 232 that is bolted to the side of the vehicle chassis 32, above the hydraulic motor mounting plate 216 and further to the rear of the vehicle.
Similarly, one end of hydraulic motor 220, as seen in FIG. 2, is connected by a clevis to the bearing 104 at the upper end of upstanding member 86 of the push frame 16, the other end of motor 220 being connected by a pin 234 to the extension arm 226 near one end thereof. The other end of extension arm 226 is attached by a mounting pin 236 to an anchor pad 238 that is bolted on the other side of the vehicle chassis 32, at a position substantially directly opposite the position at which anchor pad 232 is bolted to the chassis 32.
Actuation of hydraulic motors 220 and 222 is in unison. Upon such actuation the push frame 16 and thereby the variable wing plow blade 110 are tipped forwardly or backwardly about the axis of the pivot bearings 62, 66 or 64, 68 in the pivot mounts 58 and 60 to position the plow blade to the desired pitch angle position. With the length of each of the arms 224 and 226 selected to form a parallelogram with the combined length of frames 12, 14 and 16, such adjusted pitch angle of the plow blade is not changed upon variation in the height above the ground of the plow blade.
In general the fluid supply means, the hydraulic piping or circuitry, and the control panel means for selectively actuating the several hydraulic motor means form no part of the present invention and have not been illustrated in order to avoid undue complication of the drawing. The invention features, however, the use of relief valve means in connection with the hydraulic motors 206 and 208 provided for actuating the wing blades 116 and 114, respectively, for releasing pressure in the associated hydraulic motor cylinder in the event either wing blade hits an immovable object while the vehicle is in motion. Upon such release in pressure in the hydraulic cylinder, the associated wing blade is allowed to deflect around its hinge connection to the center blade 112, thereby avoiding damage to the wing blade and also to the center blade.
Specifically, there are provided relief or cushion valves 240 and 242 in the hydraulic fluid line connections 244, 246 and 248 to the hydraulic motors 206 and 208, as illustrated in FIG. 16. Relief valves 240 and 242 may be of known type, and for example, may each comprise a Vickers relief valve, a balanced piston type relief valve with piston of equal areas on both sides and which provides for the escape of hydraulic fluid directly to the tank in the event of excessive fluid pressure in the lines to motors 206 and 208. As shown in FIG. 16, fluid line 244 is a common line connected through both of relief valves 240 and 242 to one fluid input of both of the hydraulic motors 206 and 208. Line 246 is connected through relief valve 240 to the other fluid input of motor 206. Similarly, line 248 is connected through relief valve 242 to the other fluid input of motor 208. It is believed that the operation of the relief valves in releasing pressure in the associated motor in the event that either wing blade 114 and 116 hits an immovable object will be apparent to those skilled in the art.
Thus, there has been provided in accordance with the invention a novel variable wing plow blade and a novel mounting structure or assembly therefor that avoids the problems and limitations of the prior art blades and mounting structures or assemblies. The novel mounting assembly provides the essential structural strength required while permitting a reduction in the size, weight and number of components required, thus achieving a desired reduction in cost of manufacturing and assembly. The assembly further provides improved performance in respect of rendering substantially independent of each other the height and pitch angle adjustments of the plow blade. Additionally, the assembly and novel plow blade provide greater freedom of movement of the plow blade with respect to the assembly than is possible with the prior art constructions, including movement, both independently of each other and with respect to the center blade, of the wing blades, rearwardly as well as forwardly of the center blade. Motor means comprising double acting hydraulic cylinders or jacks enable the various plow blade adjustments to be made from a control panel in the cab, relief valve means being provided for avoiding damage in the event either wing blade hits an immovable object while the vehicle is in motion. | A variable wing plow blade and mounting structure for attaching the plow blade to a tractor, snow grooming vehicle, and the like feature distribution of the load on the blade over a relatively wide area of the supporting structural members thereby to permit reduction in their size, weight and number and in their manufacturing and assembling costs while maintaining the essential structural strength, and are further characterized in the attainment of improved performance and utility in respect of independence of the plow blade height and pitch or roll, tilt and wing blade adjustments, and greater freedom of movement of the wing blades of the plow blade, both forwardly and rearwardly, from a position of alignment with the center section of the plow blade. | 4 |
FIELD
The present application relates to means for controlling the passage of items from an area to another. More specifically, but not exclusively, the present invention is concerned with a gate system and method for monitoring and controlling the flow of items such as persons or objects, particularly for assessing flow direction and detecting, signaling and discouraging counter-flow passages.
BACKGROUND
In many circumstances, it is desired to provide a gate to enable access of persons in one direction, i.e. from a first area to a second area, while preventing or at least detecting circulation in the opposite direction. Such control is required for example to enable people to freely enter a store through certain portals while exit is only permitted through other portals.
Turnstiles are often used for such a purpose, but they present important limitations since they do not provide detection of a person jumping across the gate to exit, they present a serious hindrance to the passage of handicapped persons and shopping carts, and they are not adapted to enable free circulation in the opposite direction to let people freely exit the controlled area in case of emergency such as in the event of a fire alert. Similarly, gates comprising two or more sequential interlocked arms, wherein the first arm must be opened to unlock the second arm, may also be fooled by having a person keeping the first arm open thus enabling other persons to exit.
A number of more sophisticated gates and barriers have been provided in the prior art in attempt to overcome the above limitations and drawbacks, most of them relying on a simple motor driven pivotal arm and different sensing devices to manage arm operation in connection with people detection to allow one-way or two-way circulation of incoming persons while preventing arm/people interferences. This prior art solution discloses a passage barrier comprising a swiveling barrier and at least one sensor technology located in the sidewalls along the passageway and emitting a detection wave to detect the presence of a person in the swiveling area and/or the swiveling angle of the barrier. The prior art further teaches that multiple sensors may be used to determine the position and direction of movement of the person and that the barrier is at least partly made of detection wave transparent material.
However, it is well known that this type of system based on a motor driven barrier automatically opening when presence of an incoming person is detected presents a poor performance for preventing persons from exiting through the barrier when it is open to let other persons enter. While gates according to this concept keep the barrier arm locked in a closed position as long as no person has been detected at the entry end, they suffer from the same limitation as the interlocked arms when presence is detected at the entry end. Furthermore, in addition to presenting a risk of hurting a person in case of misdetection; this type of motor driven barriers moving slowly for safety concerns limits the circulation flow speed. In spite of the number of sensors that can be used according to concepts of the prior art, no indication is disclosed as to the method of controlling the barrier as a function of the signals provided by these sensors, especially in the case of multiple discontinuous detections along the passageway, momentary detections, etc.
It would therefore be a significant advance in the art of gate systems to provide a gate and method enabling accurate detection and tracking of the flow of individual detectable items, such as persons, animals or objects, passing through a gate system and taking appropriate actions without the need for a motor driven barrier arm, thereby providing accurate flow control as a turnstile, without the associated drawbacks.
Therefore, there is a need to provide a flow control gate and associated advanced method to obviate the limitations and drawbacks of the prior art.
SUMMARY
It is a broad aspect of an embodiment to provide flow control gate system comprising:
a first and second elongated barrier members defining a passageway between a first area and a second area;
a plurality of narrow beam presence sensors with substantially constant spacing therebetween defining a linear array mounted along a barrier member and defining a presence detection beam orientation crosswise and substantially perpendicular to the passageway, and
a controller electrically connected to the plurality of narrow beam presence sensors and implementing an operating program to process signals from the plurality of narrow beam presence sensors and define valid detection periods to determine that an item is detected when a detection period is equal to or longer than a predetermined value and invalid detection periods interpreted as no detection when a detection period is shorter than said predetermined value.
It is another broad aspect of an embodiment to provide a method for monitoring and controlling a flow of detectable items through a passageway, the method comprising:
providing a linear array having a plurality of narrow beam presence sensors along the passageway, from an entry end to an exit end, for generating detection signals indicative of the presence of a detectable item;
reading signals from the plurality of narrow beam presence sensors in sequence at predetermined time intervals;
allocating a detection value to each sensor, the detection value for each sensor is zero (0) if a detection period of the corresponding signal is less than a predetermined value and one (1) if the detection period is equal to or larger than the predetermined value;
generating an item variable when the detection values of a first sensor (S 1 ) and a second sensor (S 2 ) at the entry end pass from zero (0) to one (1) and one (1) to zero (0) respectively from a first reading time interval to a second time interval; and
storing detection values representative of an item in the corresponding item variable for a plurality of time intervals, so that a position number representative of the physical position of the item in the passageway at a given time may be calculated by summing the detection values in the item variable for the corresponding time interval and dividing the result by the number of consecutive detection values that are different from zero (0) in the item variable.
BRIEF DESCRIPTION OF THE DRAWINGS
Similar parts are identified by identical or similar numbers throughout the drawings. In the appended drawings:
FIG. 1 a is an isometric view of a flow control gate according to an embodiment;
FIG. 1 b is a side elevation view of the gate of FIG. 1 a;
FIG. 1 c is an elevation view of the gate of FIG. 1 a , as seen from the exit end thereof;
FIG. 2 is a schematic top view of the passageway;
FIGS. 3 a and 3 b are right side isometric views of a flow control gate according to an alternate embodiment, respectively with and without top rail covers installed; and
FIGS. 4 a and 4 b are respectively a left side isometric view of the gate of FIG. 3 a and a left hand side isometric view of the gate of FIG. 3 b.
DETAILED DESCRIPTION
In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures or techniques. It will be apparent to those skilled in the art that the system and method described hereinafter may be practiced in other embodiments that depart from these specific details.
Referring to FIGS. 1 a - c , the non-restrictive illustrative embodiment is basically concerned with a flow control gate system 100 for monitoring and controlling a flow of items such as persons, animals or objects circulating in a passageway 20 , from an entry end 21 to an exit end 22 .
The flow control gate system 100 basically comprises a first top rail 101 provided with a plurality of sensors 102 forming a longitudinal linear array on the inner side of the top rail 101 . The flow control gate system 100 may use, for example, from four (4) to approximately eight (8), while not being limited to this number of sensors. Sensors 102 may be retro-reflective photo-sensors projecting a narrow beam B of infrared radiation substantially perpendicularly across the passageway 20 . Alternatively, sensors 102 may comprise receptors paired with corresponding emitters provided in an opposite top rail 106 , or a combination of sensors of different types. Each sensor 102 is self-contained and comprises an infrared radiation emitter and a detector for detecting IR radiation scattered by an object, an animal or a person passing in passageway 20 . Accordingly, other types of narrow beam presence sensors could be used such as ultrasound sensors or active or passive optical sensors using a laser or a narrow beam of light in an appropriate frequency range which provides reliable object detection and prevents false detection. Although a passive type may be preferred for simplicity of construction, an active type of sensor comprising a beam detector to be located across the passageway 20 in alignment with the emitter could be contemplated as well. Such an arrangement is shown in the alternate embodiment illustrated in FIGS. 3 a , 3 b , 4 a and 4 b , wherein each one of the presence sensors 102 comprises a photoelectric receptor 102 ′ and the second top rail 106 comprises photoelectric emitters 202 in operative alignment with the receptors 102 ′. The eight photoelectric receptors 102 ′ are conveniently mounted by pair on four printed circuit boards 115 inside the first top rail 101 , under the cover 116 provided with narrow beam shaping windows 117 in optical register with each receptor 102 ′. Reciprocally, the eight photoelectric emitters 202 are conveniently mounted, for example, by pair on four printed circuit boards 215 inside the second top rail 206 , under the cover 216 provided with windows 217 in optical register with each photoelectric emitter 202 to enable photo-beams such as B′ to exit the rail 201 and strike the detectors 102 ′ when no item, such as an object, an animal or a person may obtrude the direct lines of sight.
In FIGS. 1 a to 4 b , the rail 101 is supported on a structure to form a first upright elongated barrier side member 103 anchored to the ground G through legs 104 a , 104 b , and defining one side of passageway 20 for preventing passage of items through the side member.
The opposite side of passageway 20 is defined by a second upright elongated structure defining a second barrier side member 105 comprising a second top rail 106 , anchoring legs 107 a , 107 b mounted on ground G, and a radiation absorbing panel 108 extending from the top rail 106 to absorb energy from beams emitted by sensors 102 when no item is located between a sensor and panel 108 . In another embodiment, the panel 108 can be replaced by adapting the second top rail. In FIGS. 3 a , 3 b , 4 a and 4 b a second top rail 206 is adapted to enclose photoelectric emitters 202 as described above.
A barrier arm 109 can further be mounted to top rail 101 for swiveling movement between a first position across the passageway 20 as illustrated in FIGS. 1 a and 1 c , and a second open position wherein the barrier arm 109 extends substantially parallel along rail 101 . The barrier arm 109 is invisible for sensors 102 and creates no interference with item detection. For example, the arm 109 can be strategically positioned between the second (S 2 ) and the third (S 3 ) sensors of array 102 for proper operation as described in the following. The barrier arm 109 can be alternatively swiveled towards entrance 21 or towards exit 22 . The barrier arm 109 can be mechanically locked in closed position to prevent opening and thereby allow a one-way or two-way flow control gate system 100 through the lock actuating mechanism 118 , under the electrical control of a controller 120 .
The controller 120 may be remotely connected to the flow control gate system 100 or may be partly or completely integrated into the rail 101 . When the controller 120 is integrated into the rail 101 , the controller is electrically connected to each sensor 102 through input ports and has output ports driving visual displays 111 and 112 , respectively providing green and red gate status signals for indicating a normal or alert condition.
Further peripherals such as a speaker 113 may be connected to and activated by the controller 120 according to detection conditions. The speaker may be replaced with a buzzer, a beeper, etc. The flow control gate system 100 may further comprise a key switch 114 mounted on an outer side of rail 101 and electrically connected to an input of the controller to allow an operator to disable the flow control gate system 100 and allow free circulation across the passageway 20 .
In normal operation, when manager key switch 114 is turned ON, the green display 111 is lit and the barrier arm 109 can be freely pushed by a an item such as person, an animal or an object entering the passageway 20 by the entry end 21 , as detected by photoelectric sensors 102 . If by analysis of the signals from the sensors 102 , the controller determines that an item (object, animal, person) or group is entering by the exit end 22 or is circulating from the exit end 22 toward the entry end 21 , it can take an action such as locking the barrier arm 109 in its closed position, sounding an alarm through speaker 113 , activating the red display 112 (and disabling the green display 111 ), or driving any other peripheral connected to the controller 120 such as a camera to record a picture or video sequence of the scene taking place within the passageway 20 . Even if the barrier arm 109 is open the lock will not be engaged but the rest of the safety devices (buzzer, camera, etc.) will remain functional. If the key switch 114 is turned to OFF, the controller 120 stops monitoring the passageway 20 and the barrier arm 109 can be freely moved in both directions or can be attached along rail 101 in a steady open position and no action will be taken by the controller in any circumstances. Similarly, an input signal from a fire alarm system 300 detected by the controller at any time would also disable the flow control gate system 100 to leave free access from the exit end 22 to the entry end 21 of the flow control gate system 100 .
According to the internal operation of the flow control gate system 100 , an operating program in the controller 120 monitors signals from the plurality of sensors 102 , for example, about ten times per second and carries out calculations to define items (actually objects, persons or animals) and enable determination of item variables such as the current position of each item along the linear axis defined by the sensor array within the passageway 20 (alignment with sensors 102 or exit of the item), specific item flow direction and speed, mean flow direction and speed of items, as well as item passage counters. The operation program operates according to a method described in detail in the following.
Referring to FIG. 2 , a schematic top view of the passageway 20 is represented showing an item identified as OBJECT in the passageway monitored by x photo-beams B from x photoelectric sensors 102 individually identified as S 1 to Sx, from the entry end 21 to the exit end 22 of the flow control gate system 100 . As long as the objects or persons to be detected are larger than the spacing between adjacent sensors 102 , the concept is analog to taking an x pixel image of the passageway 20 and analyzing the image to locate items. Therefore, appropriate spacing of the sensors 102 must be implemented according to the expected size of the items to be detected. For example, it has been found that a sensor spacing between six (6) to ten (10) inches may provide adequate resolution for reliable monitoring of individuals circulation. Each sensor is being allocated a weight value as follows: S 1 =1, S 2 =2; S 3 =3; S 4 =4; . . . Sx=x.
At every polling sequence, which may occur 10 times per seconds (reading intervals of 0.1 second), if a presence is detected by a sensor 102 for at least a predetermined time period T, the sensor is being attributed an ON status, otherwise, it is being attributed an OFF status. It has been found that positive results were obtainable using a minimal detection time period T of 0.1 second to attribute an ON status to a sensor, and by maintaining the ON status for a predetermined period of time, for example, about 0.3 second after the sensor stops outputting a detection signal. This feature, comparable to a key debouncing feature, is required to take into consideration that a sensor 102 may be momentarily triggered by something that cannot be considered as a person, an object or a group circulating in the passageway 20 at a predictable speed. For example, balancing arms of a person, carried objects or small parts of a shopping cart or basket may thereby be eliminated from the objects/person recognition algorithm for optimal accuracy. Detection values representative of an item, may be stored in an x-dimensional variable for each reading time interval, sensor Sn being given a value equal to 0 for an OFF status and to “n” for an ON status.
Object monitoring: Letting T 0 be the current time and T−1 the time before the last time increment, a new item variable is generated every time sensors S 1 and S 2 were OFF at time T−1 (previous time interval) and S 1 becomes ON at time T 0 (current time interval) while sensor S 2 is still OFF. An item is represented by a y-dimensional variable representing a series of y consecutive ON sensors, wherein Sn takes the weight value n. Therefore, an item variable takes the form O=(Sn, Sn+1, Sn+y). For example, the object in FIG. 2 would be attributed the variable (2, 3) or (0, 0, 2, 3, 0, . . . , 0), for y=2 consecutive sensors ON, sensor S 2 and sensor S 3 .
The current position of an object is then calculated by summing the numbers in the object variable O (2+3=5 in this example) and dividing by the number y of ON sensors (2 in the example), giving a position of 2.5 for this example, meaning that the object is considered to be located between sensor 2 and sensor 3 along the linear axis defined by the photo-sensors array in rail 101 along the passageway 20 . Thus, the current position (distance) Do of any object is given by: Do=Σ(Sn, Sn+1, Sn+y)/y. This method can thus be applied to track more than one object simultaneously if more than one series of consecutive ON sensors separated by at least one OFF sensor can be identified in an x-dimensional variable representing the status of all the sensors S 1 -Sx at a given time. An item continues to exist in the passageway 20 as long as its position value Do is ≧1 and ≦x, and that at least one sensor in its item variable O remains ON.
Every distinct virtual item created at sensor S 1 and reaching sensor Sx corresponds to an actual person or object that really crossed the flow control gate system 100 from the entry end 21 to the exit end 22 of the passageway 20 . Therefore, an item counter can be incremented within the controller 120 to accurately track the number of items (persons, animal or objects) who/which crossed the flow control gate system 100 within a given period of time.
Flow determination: The specific flow of an item is given by: Fo=Do (T 0 )−Do (T−1). If Fo=0, the item is not moving; if Fo, >0, the item is moving in the right direction (toward exit 22 ), and if Fo is <0, the item is moving in the wrong direction (toward entry 21 ), which may cause the controller 120 to take an appropriate action.
A representation of the total flow of items in the passageway 20 may also be calculated to determine if an item is trying to circulate in the wrong direction (from the exit end toward the entry end) while at least another item is moving in the right direction at the same time. The total flow Ft=Σ (all Sn ON)/(total number of ON sensors in the array). If Ft=0, the mean flow in the passageway is null; if Ft, >0, all items are moving in the right direction, and if Ft is <0, at least one item is moving in the wrong direction, which may cause the controller 120 to take an appropriate action.
Speed: Since the position of all items is known at all time, and the poling interval is known, a progression speed may be calculated and associated with each item.
According to the above described structure and operation of an embodiment, it is contemplated that operating features may be incorporated as follows, as described in the context of a store entry control, to allow control of a store access with a flow control gate system 100 . It can be understood that the flow control gate system 100 is not limited to a store entry control but can also be used in premises or area where the entrance is required or wished to be controlled. For example, the flow control gate system 100 can be used in subway, government facilities, industrial facilities, production lines, etc.
Normal Flow into the Store:
A green light 111 may indicate that a client can walk through the passageway 20 . An optional welcome message may be emitted through the speaker 113 to greet a customer while entering the flow control gate system 100 .
Should a client stall in the passageway 20 , then he/she may be prompted to move forward by a single BEEP alarm signal (SB) from speaker 113 .
Should anyone move backward to exit the store through the flow control gate system 100 , then a warning message may first warn the client that he/she is circulating in the wrong direction. For example, if a client backs-up a little, a more insistent double BEEP alarm signal (BB) may be sounded through speaker 113 .
Should the sensors 102 detect that a client keeps on moving in the wrong direction, creating a negative flow, then a loud alarm sound from a buzzer (LB) in the speaker 113 may be trigged.
If a client moves past sensor S 3 (past barrier arm 109 ), the lock actuating mechanism 118 will not be engaged if whichever other event occurs until the client who entered in the right direction is out of the flow control gate system 100 .
Unauthorized Flow from the Store Towards the Entrance:
If no presence is detected, then the system is on standby and the green light 111 is on.
If someone triggers sensor S 8 , then the flow control gate system 100 will lock the barrier arm 109 and SB will be sounded until the intruder moves back out past sensor S 8 , unless intruder disappears without passing back out sensor S 8 , in which case lock would be maintained and a 5 second LB would be triggered.
Whenever an alarm is triggered and sounded through the speaker 113 or whenever the barrier arm 109 is locked, the red light signal 112 at the front end of the flow control gate system 100 may indicate an entering client not to engage in the passageway 20 .
The flow control gate system 100 may unlock the barrier arm 109 and return to the green light only if the client leaves the sensor area or generates a positive flow by entering the store.
Should sensors S 1 and S 2 be triggered by an entering client without opening the arm 109 while sensor S 8 is triggered, then the barrier arm 109 will lock and LB will be sounded.
Should sensors S 1 , S 2 and S 3 be triggered and the barrier arm 109 is opened by an entering client while sensor S 8 is triggered, the LB will be sounded and the lock actuating mechanism 118 will not be engaged.
In any of the preceding events, the flow control gate system 100 will automatically reset itself if there is no presence and if any extended programmed alarm is completed or disabled.
Emergencies, Fire Alarm, Manager Control, Customer Service Control and Power Failures, etc:
If no electrical power supplies the flow control gate system 100 , then when the lock actuating mechanism 118 will be disabled and if the barrier arm 109 is fully opened a spring loaded mechanism (not shown) will keep the barrier arm 109 open until power comes back. Then the flow control gate system 109 will reboot and the barrier arm 109 will be released back to its closed normal position.
If the manager's key switch 114 is turned from active to disabled position, the flow control gate system 100 will enter a sleep mode as for power off above, except that the green light 111 will flash until the key switch is positioned to the active mode, which will return the system to its active mode. The key operated mechanism may thus allow a manager to disable the flow control gate system 100 and leave the barrier arm 109 open.
The flow control gate system 100 can be linked to any fire alarm system to be disabled in case of emergency and let a free flow passage in both directions. If the fire alarm input 300 is triggered, then the system 100 may enter a sleep mode as above, with the green light flashing until fire alarm is cancelled. Then, the system returns to its active mode.
A customer service button (not shown) may further be provided on the top rail 101 . If the Customer service button is activated and held, then the gate system 100 will enter a sleep mode as above, with the green light flashing, until the button is released. Then the flow control gate system 100 returns to its active mode.
A panic button (not shown) may be provided on the flow control gate system 100 or remotely located to be usable from the store side, and connected to controller 120 . If the panic button is activated, then LB will be sounded, the green light 111 will flash alternatively with the red light 112 and the arm 109 will be locked for a period of time such as fifteen (15) seconds, then the lock actuating mechanism 118 will be disabled enabling the barrier arm 109 to be maintained open if moved to its fully opened position in which it would be held by the spring loaded mechanism (not shown). Then the barrier arm 109 can be rearmed by resetting the panic button and operating the manager's key switch 114 to reboot the system.
If the panic button is activated, then LB will be sounded, the green light 111 will flash alternatively with the red light 112 and the arm 109 will be locked. If the panic button is reset within a period of time such as fifteen (15) seconds, the flow control gate system 100 will return to its active mode.
In any event, the flow control gate system 100 will automatically reset itself if there is no presence and if any extended programmed alarm is completed or disabled.
On top of the aforementioned functions, the flow control gate system 100 can also deliver a true count, in real time of the traffic entering the store and can be linked to other electronic systems to study and control traffic in the store, time of the day clientele profile, forecast rushes at the cashiers and much more.
It can thus be easily appreciated that the above-described non-restrictive illustrative embodiments. More specifically, the gate and associated method of operation enable accurate detection and tracking of the flow of individual detectable items, such as persons, animals or objects passing through the gate, calculation of their position, speed, direction, etc. and taking appropriate actions, without the need for a motor driven barrier arm or turnstile, thereby providing accurate flow control as a turnstile.
Although the flow control gate system has been described in the foregoing Detailed Description and illustrated in the accompanying Figures, it will be understood that the flow control gate system and associated method are not limited to the embodiments disclosed, but are capable of numerous rearrangements, modifications and substitutions, without departing from the scope of the claims. | A flow control gate system that comprises a first and second elongated barrier members defining a passageway between a first area and a second area. The gate system also comprises a plurality of narrow beam presence sensors with substantially constant spacing therebetween defining a linear array mounted along the first barrier member and defining a presence detection beam orientation crosswise and substantially perpendicular to the passageway. The gate system further comprises a controller electrically connected to the plurality of narrow beam presence sensors. The controller implements an operating program to process signals from the plurality of narrow beam presence sensors and define valid detection periods to determine that an item is detected when a detection period is equal to or longer than a predetermined value and invalid detection periods interpreted as no detection when a detection period is shorter than the predetermined value. A flow control method is further provided. | 4 |
This invention relates to exciter circuits for operating fuel igniters in gas turbine engines. More specifically, this invention relates to circuits and method for delaying a high current igniter pulse to reduce wear and erosion of igniter contacts and surfaces.
BACKGROUND OF THE INVENTION
Jet engine igniters are used, in a manner similar to automobile spark plugs, to ignite an air-fuel mixture in the combustion chambers of gas turbine engines. Igniters typically comprise two concentric electrodes separated by an insulator, for example, aluminum oxide. A high voltage is applied to the central electrode to initiate an electric discharge in the air-fuel mixture. Current in the electric discharge then rises to deliver sufficient energy to initiate ignition of the mixture.
Jet aircraft engine igniters are utilized during engine startup and are, additionally, operated as a precaution against flame-out during take off, landing, and poor weather conditions. Typically, an igniter is operated approximately ten percent of engine running time.
Igniters for engines in heavy jet aircraft typically operate under particularly severe conditions. For example, in the General Electric Company CF6-50 engine, which powers the McDonald-Douglas DC 10 aircraft, a power supply (the exciter) delivers brief, high voltage pulses to the igniter with a pulse energy in the range of from 1 to 2 joules at a repetition rate of 2 pulses per second. The igniter must operate over a pressure range from approximately 5 psia to over 200 psia at shell temperatures which range to approximately 2000° F. Frequently, igniters become covered with liquid jet fuel under cold starting conditions. The lifetime of an igniter is, therefore, limited to approximately 100 hours of exciter operation.
The insulator in prior art igniters has frequently been shunted with a body of semiconductor material, for example, a thin film on the insulator surface. Such "shunted igniters" have been found to fire at substantially lower voltages than unshunted igniters and thus tend to reduce the weight and cost of associated exciter circuits. The high power required for reliable ignition in heavy jet engines has, however, been found to cause a rapid erosion of the semiconducting film, a condition which leads to unreliable ignition.
SUMMARY OF THE INVENTION
I have conducted high speed, photographic studies of arc discharges on igniters of heavy jet aircraft engines and have determined that the discharge initiates along an insulator surface and, after delay of several microseconds, tends to move away from the insulator surface at near sonic velocities. With prior art exciter circuits, substantial energy is delivered in a short arc, close to the insulator surface subjecting the insulator ceramic to severe thermal stress.
I have, further, determined that thermal stress on igniter insulators may be reduced by use of an exciting current waveform which initiates a discharge under relatively low power conditions and, after the discharge has moved away from the insulator surface, increases the discharge power to assure reliable fuel ignition. Thermal stress is thus reduced and igniter lifetime increased by a circuit which provides substantially more reliable ignition than did prior art exciter circuits.
It is, therefore, an object of this invention to provide exciter circuits for increasing the lifetime of jet engine fuel igniters.
Another object of this invention is to increase the reliability of jet engine fuel igniter equipment.
Another object of this invention is to delay the main pulse in jet engine igniter circuits until a discharge column has separated from the igniter surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features which are believed to be characteristic of the present invention are set forth in the appended claims. The invention itself, together with further objects and advantages thereof, may best be understood by reference to the following detailed description, taken in connection with the appended drawings in which:
FIG. 1 is the current waveform which is delivered to a jet engine igniter by an exciter circuit of the prior art;
FIGS. 2a-2c are improved current waveforms for use with jet engine igniters in accordance with the present invention; and
FIG. 3 is a circuit for generating the waveform of FIG. 2c.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a tracing of an oscillogram of the waveform delivered by a prior art exciter to an igniter in a General Electric CF6-50 jet engine. The exciter pulse, which provides high power required for fuel ignition, is approximately a damped sine wave with a main power pulse which reaches a level of approximately 2000 amperes within approximately 8 microseconds. High speed photographs of arc discharge columns produced by this exciter waveform in various models of shunted and unshunted igniters indicate that a discharge first forms as a narrow arc channel near the insulator surface. This channel does not move or change shape significantly during the first two microseconds, but then expands greatly and shoots up from the igniter surface at near sonic velocities (i.e., approximately 200 meters/second) as the current rises to 2000 amperes. On some igniters, the discharge concentrates again near the insulator surface on later half cycles of the discharge.
The movement of the discharge away from the surface is probably partially due to evaporation and expansion of material near the igniter surface. The movement may also be partly due to the well-known outward force exerted on a current in a curved path which is caused by the interaction of the current with its own magnetic field.
In accordance with the present invention, the performance of igniters may be improved by modifying the exciter circuit to delay the high current pulse of the main discharge until after approximately 30 microseconds of an intermediate current discharge (i.e., approximately 500-1000 amperes), have elapsed. In this manner, the high current pulse is delivered after the discharge has moved a few millimeters away from the igniter surface. Delayed application of the main discharge pulse provides more reliable ignition because the discharge path is longer and extends further into the fuel-air mixture. It also tends to increase igniter life since the peak power is delivered further away from the delicate igniter surface.
FIG. 2a-2c waveforms of improved current pulses of the present invention. In all cases, the application of the high current pulse is delayed for approximately 30 microseconds after the initiation of the discharge.
FIG. 3 illustrates an exciter circuit for delivering a current waveform of the type illustrated in FIG. 2c. An igniter 10 is connected in series with a high voltage pulse capacitor 12, a triggered spark gap 14, and a current limiting inductor 18. A second pulse capacitor 20, which should have a larger energy storage capability than the first capacitor 12 and may have a lower voltage rating than that of the first capacitor, is connected in series with a second triggered spark gap 22 directly across the igniter 10. A high voltage charging circuit 16 which may be any of the various types of charging circuits utilized in capacitor discharge type circuits, is connected to the capacitor 12 while a second charging circuit 24, which may have a lower voltage rating than the charging circuit 16, is connected to the capacitor 20. A trigger input signal 26, which may be supplied by conventional exciter trigger circuitry, is initially delivered to the spark gap 14 which is connected in series with the high voltage capacitor 12. The trigger signal 26 is also applied to the spark gap 22 through a delay circuit 28 which, typically, provides approximately 30 microseconds delay.
The high voltage capacitor 12 provides a pulse which breaks down the igniter 10 gap and then provides a moderate current discharge through the igniter which is limited by series inductor 18. After a suitable delay, which allows the discharge to separate from the igniter surface, the second capacitor 20 delivers a larger main current pulse, at much lower voltage, to the igniter. The basic circuit illustrated in FIG. 3 may, if desired, be modified with voltage doubling circuits, output transformers, and other accessories which are well known and utilized in exciter circuits of the prior art.
The ratios of the magnitude of the current pulse delivered in the first portion of the waveform and that delivered during the main current pulse will, of course, be determined by the requirements of the particular igniter and engine configuration utilized. The low current pulse at the beginning of the waveform should typically have an amplitude from approximately ten percent to approximately 50 percent of the main current pulse. For the CF6-50 engine and igniters, a delay of 20-40 microseconds is indicated. If the delay is too short, the discharge will not separate sufficiently from the insulator surface while, if the delay is too long, the discharge may revert to a shorter path.
The circuits and methods of operation of the present invention provide increased ignition reliability in gas turbines and jet aircraft engines and extend the life-time of igniters which operate under high energy pulse conditions.
While the invention has been described in detail herein, in accord with certain preferred embodiments thereof, many modifications and changes therein may be effected by those skilled in the art. Accordingly, it is intended by the appended claims to cover all such modifications and changes as may fall within the true spirit and scope of the invention. | Jet engine fuel igniters are excited with a current waveform which maintains an intermediate current value until a discharge has separated from the igniter surface. The current then rises to a higher level to provide sufficient energy for ignition of an air-fuel mixture. Ignition reliability is thus increased and the effects of erosion on the igniter surface are decreased. | 5 |
BACKGROUND OF THE INVENTION
The present invention is directed toward an extracting device, and more particularly, to an extracting device for removing objects from the nasal and ear passages, wherein the device may be used by physicians, other health care providers, and by laypersons as a home remedy.
Human nature leads children, and sometimes adults, to put objects where they don't belong. All too frequently, these places are a part of the human body. Nasal cavities, ear canals and throats are the most common areas into which objects are placed haphazardly or accidently lodged, causing discomfort, injury and occasionally, serious injury. Physicians frequently are visited by children having potentially dangerous foreign objects lodged in these or other places. Forceps are the most common device for removing such foreign objects from the passageway being blocked. However, forceps can be damaging to the sensitive tissues which often make up these passageways and thus, further damage may result during the attempted removal of the object. This method is often lengthy and traumatic for a child, and it may be unsuccessful, resulting in surgery.
Medical technology does include devices for removing objects from human body passages. Such devices are most frequently used for removing naturally formed stones or the like from areas such as the urinary passage. These devices are generally directed toward use with these particular passages and frequently are complex, frightening in appearance and require professional expertise and training as well as considerable and excessive manipulation and/or stabilization. These common traits of these devices are incompatible with the uses to which the instant invention are directed, i.e. toward children requiring immediate and minimally irritating and frightening attention. These devices are frequently expensive and not available for use by laypersons. Several of these devices are discussed below.
U.S. Pat. No. 4,295,464 to Shihata discloses a ureteric stone extractor with two balloon catheters. The extractor includes an inner catheter having an eccentric balloon attached to its distal end. The device also includes an outer dilatator catheter having a balloon attached to its distal end. In operation, the catheter is inserted into the ureter so that the balloon in a deflated state moves behind an object to be removed such as a stone. The balloon is then inflated and moved into contact with the object to be removed. The two balloon design of the Shihata device is more complex than necessary for the instant application, would require sedation, and would result in unnecessary discomfort to the patients. Additionally, the means of inflation and general complex appearance of the device are not conducive to reducing the escalation of anxiety in patients, particularly young patients, which frequently accompanies medical treatment. Finally, unlike the instant invention, the Shihata device would require two hands to operate as well as additional assistance to stabilize the child or other patient.
U.S. Pat. No. 4,469,100 to Hardwick is related to an extraction device for removing foreign bodies, such as a stone, lodged in a human body passage, such as a ureter. The device includes a double lumen catheter with one lumen attached to a pressure source and the second lumen attached to a suction source. A balloon surrounds the catheter and is inflated about the stone to be removed. Similar to Shihata, the Hardwick device is too complex for the instant application, requiring both a suction and pressure source whose appearance would tend to instill great anxiety in young patients. Also, the need for suction and pressure lines would make the use of the Hardwick device in homes nearly impossible and the design of the Hardwick device would also require two hands to operate.
Finally, U.S. Pat. No. 4,597,389 to Ibrahim et al. relates to a device for removing objects from tubular body passages. The device includes an elongated element having a ring at its distal end. A balloon is mounted within the ring. The balloon communicates with an air line in the tube and can be inflated after the ring has been moved about an object to be withdrawn. A syringe is used to inject air into the airline and thereby inflate the balloon. The Ibrahim device would be unacceptable for the use to which the present invention is directed in that the ring is too intrusive for use in a nasal or ear passage and the use of a syringe for inflation requires two hands for operating the device, one to hold the device and one to operate the syringe. When working with children, one hand is necessary for controlling the child where the other is necessary to control the device. Accordingly, like the other devices discussed above, without assistance, control of the patient would be lost while using the Ibrahim et al. device.
Hence, there exists a need in the medical care industry for a nasal and ear foreign body extracting device that is easy and safe to use for physicians, other health care providers, and laypersons for at home care, inexpensive to manufacture and purchase, and which is gentle to delicate tissues and gentle in appearance.
SUMMARY OF THE PRESENT INVENTION
The primary object of this invention is to provide an effective foreign body extracting device which is easily manipulated and held with one hand.
Another object of this invention is to provide a foreign object extracting device which is simple and safe to use for home care as well as physician care.
Yet another object of this invention is to provide a foreign object extracting device which is inexpensive to manufacture and purchase.
A still further object of this invention is to provide a foreign object extraction device which has an appearance which minimizes anxiety in patients, particularly young patients.
A still further object of this invention is to provide a foreign object extraction device comprised entirely of soft and gentle materials which is not traumatic to sensitive tissues comprising body passages.
An even further object of this invention is to provide a foreign object extraction device having utility in removing objects from nasal and ear passages.
The foregoing objects are attained by the inventive foreign body extracting device of the present invention which includes an elongated tubular rod, preferably comprised of a soft material, having a compressible bulb means attached to its proximal end. The bulb means is in fluid communication with the rod in order to pump air through the rod. In addition, an inflatable balloon means is attached to a distal end of the tubular rod and is in fluid communication with the rod. The balloon means is positioned and connected with the rod so as to receive the air from the bulb means and as a result, become inflated. A gripping means may also be included for more firmly holding the extracting device and compressing the bulb means with one hand.
In using the extractor of the present invention, the end of the extractor having the uninflated balloon means attached thereto is inserted into a body passage such as the nasal passage. The rod and balloon means are carefully pushed upwardly past the foreign object and because of the preferred small size, softness and flexibility of the rod, there is little danger in forcing the object upward further into the passage. At this point in the procedure, using only one hand, the bulb means is compressed once and the balloon means is inflated within the passage. While maintaining compression, the extractor is then pulled gently from the passage, causing the balloon means to engage the foreign object and drag it out of the passage thereby clearing the same.
In one embodiment of the invention, the tubular rod is a hollow catheter comprised of a soft and flexible TEFLON material. In the same embodiment, the balloon means is comprised of a latex material which upon inflation, forms a bell shaped balloon having sloping sides for engaging the foreign object. In the same embodiment, the bulb means includes a semi rigid collapsible member having a volumetric capacity which displaces enough air for inflating the balloon on one squeeze. Also, an air tight seal is formed between the catheter and the balloon and the catheter and the collapsible member.
This embodiment also includes a hand grip means for additional dexterity and control which is comprised of a semi rigid compressible member extending over and invaginating the collapsible member. The compressible member can be easily gripped and used to compress the collapsible member, hold the extractor and maintain compression with one hand.
The details of the present invention are set out in the following description and drawings wherein like reference characters depict like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an extractor in accordance with the present invention with a balloon attached to one end in an uninflated state.
FIG. 2 is a cross sectional view of the extractor taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged cut away view of the balloon end of the extractor showing the uninflated balloon and catheter air holes used for inflating the balloon.
FIG. 4 is a side elevational view of the extractor with the balloon in an inflated state.
FIG. 5 is a cross sectional view of the extractor taken along line 5--5 of FIG. 4.
FIG. 6 is an overhead view of a second embodiment of an extractor in accordance with the present invention which includes a set of hand grips adjacent a compressible bulb and an uninflated balloon.
FIG. 7 is a cross sectional view of the second embodiment of the extractor taken along line 7--7 of FIG. 6.
FIG. 8 is an overhead view of the second embodiment of the extractor showing the specially shaped balloon inflated, the hand grips closed and the bulb compressed.
FIG. 9 illustrates the process of inserting the extracting device into a body passage.
FIG. 10 illustrates the process of removing a foreign object from the body passage via the extracting device.
DETAILED DESCRIPTION
Referring now to the drawings in detail, there is shown in FIG. 1 a side elevational view of the extracting device constructed in accordance with the principles designated generally as 10. As shown in FIG. 1, the extracting device generally includes a bulb 12 connected on one end to an elongated tubular rod or catheter 14, and a balloon 16 connected to the other end of the rod or catheter 14.
Referring now to the cross sectional view shown in FIG. 2, the elements of the extractor will be described in detail. The bulb 12 is used for inflating the balloon 16 with air. The bulb 12 is constructed from semi-rigid flexible rubber or similar resilient material. Accordingly, the bulb is molded or otherwise formed into a substantially egg shape configuration, being circular in frontal projection and discoid in lateral projection. The bulb comprises a shell portion 18, forming a chamber 20, and a nipple 22, for connection to the catheter 14. The bulb may also be formed by other configurations having a hollow center. The bulb 12 may be compressed by squeezing it but because of the semi-rigid yet flexible nature of the shell portion 18, it will return to the original shape after compression. The strength of the material is such that an average person may easily compress the bulb 12 with the application of a nominal squeezing force from the hand.
The volume of the chamber 20 of the bulb 12 is such that upon one compression of the bulb, the balloon will inflate to or below the maximum volume of inflation of the balloon. The volume of the bulb may be such that it displaces 2-3 cc of air when fully compressed. In order to maintain the inflation of the balloon 16, the bulb 12 must be held compressed, as illustrated in FIGS. 4 and 5. The need to hold compression acts as a safety measure for avoiding over inflation of the balloon 16. That is, if the compression is released the balloon will deflate, thus avoiding inflation of the balloon to a volume exceeding the volume of air in the bulb 12.
The bulb 12 is attached to the catheter 14 via a nipple 22. As shown in FIG. 2, the nipple 22 is formed along with the shell portion 18 during the molding process. The nipple extends outwardly from the shell portion 18 for connection to the catheter 14. The nipple 22 is also hollow, and defines an output port 24 of the bulb 12 for release of the air from the chamber 20 to the catheter 14. The nipple may be securely attached to the catheter 14 via gluing or via the elastic material comprising the nipple tightly fitting and gripping the catheter, or via any other suitable manner which causes an air tight seal between the nipple and the catheter for unrestricted flow of air from the chamber 20 to the balloon 16. In any case, the interior diameter of the nipple 22 is minimally larger than the outside diameter of the catheter 14 for causing a force fit.
The catheter 14, referring still to FIG. 2, is tubular in shape comprising a wall 26 which encompasses the air flow passage 28. The catheter 14 is preferably constructed from 18 gauge TEFLON but other materials may be suitable. The catheter has one open end 29, which connects to the bulb nipple 22, and one closed end 30 which extends into the balloon 16. The open end 29 allows flow of air into the catheter 14 and the closed nature of the end 30 blocks flow of air out of the catheter end. However, and referring to the enlarged view of a portion of the catheter adjacent end 30 in FIG. 3, the air from the bulb exits the catheter through openings 32 which are formed through the wall 26 of the catheter 14, adjacent the closed end 30 of the catheter. As shown in FIG. 3, the openings 32 are positioned adjacent the end 30 so that while the catheter is connected to the balloon 16, the openings are inside the balloon 16. Accordingly, air from the bulb is distributed evenly within the balloon for consistently inflating the same.
Referring still to FIG. 2, the balloon 16 is preferably constructed from latex and is fused, glued or otherwise suitably attached to the catheter 14, adjacent the closed end 30 of the catheter. As discussed above, the balloon 16 is positioned adjacent the catheter end so as to envelope the openings 32. The balloon is preferably of a size to inflate to a 1 cc volume with a maximum capacity of 3 cc, upon compressing the bulb 12. Although 2-3 cc of air may be displaced upon compression of the bulb 12, due to the imperfect nature of such compression, not all of the air displaces into the balloon 16, thus allowing for a typical inflation volume of the balloon of approximately 1 cc.
A second embodiment of the invention is shown in FIG. 6 wherein two elements, the bulb and the balloon are shown in altered designs. Each of these altered elements can be used alone or in combination with the remaining elements of the main embodiment. Referring to FIG. 6, the bulb 112 is substantially similar to as described above with similar volume capacities. However, the bulb includes a compressible hand grip 150 which may be molded with, or otherwise attached around the bulb 112. The compressible hand grip comprises two elongated portions 152 and 154 which extend over and invaginate the bulb 112. As shown in the cross sectional view of FIG. 7, the elongated portions 152 and 154 are also constructed from a semi-rigid rubber and are hollow, forming air chambers, and thus compressible and are connected at a central portion 155. The elongated portions preferably have an ergonomic semi-circular and elongated shape with outlet ports 156 and 158, shown in FIG. 7, for the release of displaced air upon compression of the portions to the atmosphere. To make the device 110 more gentle in appearance, the central portion 155 has a cartoon face or the like painted or otherwise formed thereon, as shown in FIG. 9.
As the elongated portions are squeezed, as shown in FIG. 8, the bulb is compressed. As the bulb becomes more compressed, the elongated portions become compressed thereby limiting the force which may be applied to the bulb via the members. Accordingly, by using the hand grip 150, the extractor 110 may be securely held and manipulated with one hand while the other hand is free to hold the patient. The bulb and hand grip assembly are attached to the catheter 114 similar to as described above and the catheter 114 is substantially identical to as described above.
Referring still to FIG. 8, the balloon 116 of the second embodiment preferably takes on a substantially bell shaped configuration upon inflation. The narrow end of the bell shaped balloon is fused to the catheter circumference adjacent to the catheter end 130, similar to as described above. As with the balloon 16, the balloon 116 is preferably formed from latex having a 1 cc preferred capacity and a 3 cc maximum capacity. The sloping sides of the balloon 116 cause the balloon to engage the object on a surface which tends to conform more gradually to the shape of the object. As with the catheter 14, the catheter 114 has openings which are located on the catheter so as to be encased within the balloon 116 and to inflate the same. The balloon 116 may be used with or without the hand grip 150.
The extractors 10 and 110 are used as described below. The main steps of the procedure are applicable to both embodiments, however, the figures illustrate the procedure with the second embodiment only. Referring to FIGS. 9 and 10, the catheter 114 with the balloon 116 fused to the closed end 130 of the catheter is inserted into a body passage 160, such as a nasal passage, having a foreign object 162 lodged therein. The catheter and balloon are manipulated past the object 162, as shown in FIG. 9. Once past the object, the bulb 112 is compressed via the hand grip 150 and the balloon 116 is inflated, as shown in FIG. 10, within the passage 160. The extractor 110 is then removed from the passage and the balloon 116 drags the object 162 out of the passage, clearing the same. The first embodiment is used as described above except that the bulb 12 is directly compressed by the hand. The extractor of the present invention has particular utility in removing foreign objects from nasal and ear passages.
The primary advantage of this invention is that it provides an effective foreign body extracting device which is easily manipulated and held with one hand. Another advantage of this invention is that the extracting device is simple and safe to use for home care as well as physician care. An additional advantage of this invention is that the extracting device is inexpensive to manufacture and as a result thereof, inexpensive to purchase. Still another advantage of the foreign object extraction device of the present invention is that it has an appearance which minimizes anxiety in patients, particularly young patients. An even further advantage is that the foreign object extraction device of this invention has particular utility in removing objects from nasal and ear passages.
It is apparent that there has been provided in accordance with this invention a body passage foreign object extraction device which fully satisfies the objects, means, and advantages set forth hereinbefore. While the invention has been described in combination with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. | A body passage foreign body extracting device includes an elongated flexible tubular rod having a compressible bulb attached to its proximal end. The bulb is in fluid communication with the rod in order to pump air through the rod. In addition, an inflatable balloon is attached to a distal end of the tubular rod and is in fluid communication with the rod. The balloon is positioned and connected with the rod so as to receive the air from the bulb and, as a result, become inflated. The extractor also includes a hand grip which is used for holding the extractor, compressing the bulb and maintaining compression with one hand. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to U.S. Utility patent application Ser. No. 12/185,007, entitled DEEP SUBMERSIBLE LIGHT WITH PRESSURE COMPENSATION, the content of which is incorporated by reference herein in its entirety for all purposes.
FIELD
[0002] The present invention relates generally to lighting fixtures used on manned and remotely piloted submarines. More particularly, but not exclusively, the invention relates to lights of for use at great depths that are configured to be subjected to very high ambient water pressure.
BACKGROUND
[0003] Prior art underwater lighting fixtures have used gas discharge or incandescent filaments housed in thin glass envelopes as the light source. These glass envelopes collapse at depths as shallow as 100-ft, and cannot operate in contact with any liquids. To go any deeper, these glass envelopes must be protected from direct ocean pressure to prevent them from imploding. Typical designs use a glass dome or flat window, with a metal or heavy plastic housing. A pressure proof underwater electrical bulkhead connector brings electrical power across the interface.
[0004] FIG. 1 illustrates a Multi SeaLite® light fixture 102 commercially available from DeepSea Power & Light of San Diego, Calif., assignee of the instant application. The light fixture 102 utilizes a halogen gas-filled glass envelope lamp that must be protected from direct exposure to high ocean pressure. More particularly, referring to FIG. 2 , a halogen lamp 204 is included in the light fixture 102 . The halogen lamp 204 includes a thin inert gas-filled glass envelope that is only designed to survive atmospheric pressure differences found in typical applications from sea level to mountain tops. In order to survive at great ocean depths, e.g. 3,000 meters, the light fixture 102 includes a pressure protected housing is comprised of a glass hemisphere 202 , metal back shell 206 , cowl 212 , and bulkhead connector 210 . An internal reflector 214 redirects lights from the halogen lamp 204 forward through the glass hemisphere 202 . A mount 208 permits the light assembly to attach to a manned or remotely piloted submarine. See U.S. Pat. Nos. 4,683,523 and 4,996,635 both of Mark S. Olsson et al. for further details regarding the construction of light fixture 102 .
[0005] Recently, high brightness light emitting diodes (LEDs) have begun to be used in terrestrial markets as a reliable, efficient solid state light source capable of narrow or wide chromatic bandwidth. FIG. 3A illustrates an individual Cree XRE high brightness LED 302 . It comprises light-emitting die 306 ( FIG. 3B ) illustrated centrally situated above a ceramic base 312 , encapsulated with silicone gel 310 , contained by a metallic ring 308 , that supports a transparent dome-shaped lens element 304 . Electrical contacts 314 and 320 are placed on top of the ceramic base 312 , and a duplicate pair 316 and 322 are placed on the underside. A thermal-transfer pad 318 is also located in the center of the underside of the ceramic base to aid in drawing heat away from the die 306 .
[0006] It would be desirable to provide a deep submersible light that takes advantage of the new high brightness LEDs that have become commercially available. LEDs in such a light can accommodate very high ambient water pressures directly, but due to the electrical nature of the LEDs requires that they be isolated from seawater, which is electrically conductive.
SUMMARY
[0007] In accordance with one aspect, a deep submersible light includes a body defining a hollow interior and a solid state light source such as a plurality of high brightness LEDs mounted in the interior of the body. A transparent window may be mounted over the LEDs. The space between the transparent window and the LEDs may be filled with an optically transparent fluid, gel, or grease, which allows light to pass through and ambient water pressure to pass in, thus pressure compensating the LEDs by allowing them to see ambient water pressure. The transparent window may be mounted in the body for reciprocation in both a forward direction and a rearward direction to accommodate volumetric changes in the compensating fluid, gel, or grease caused by changes in temperature and water pressure as the manned or remotely piloted submarine travels from the sea surface to deep ocean depths.
[0008] Various additional aspects, details, and functions are further described below in conjunction with the appended Drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an isometric view of a prior art deep submersible light fixture that incorporates a halogen gas-filled glass envelope lamp that must be protected from direct exposure to high ocean pressure.
[0010] FIG. 2 is a sectional side view of the light fixture of FIG. 1 taken along line 2 .
[0011] FIG. 3A is an isometric view of a prior art high intensity LED.
[0012] FIG. 3B is a sectional view of the LED of FIG. 3A taken along line 3 B- 3 B.
[0013] FIG. 3C is an isometric view of a metal core printed circuit board (MCPCB) assembly populated with eighteen LEDs.
[0014] FIG. 3D is a section view of the LED assembly of FIG. 3C taken along line 3 D- 3 D.
[0015] FIG. 3E is an isometric view of a molded reflector.
[0016] FIG. 3F is a section view of the molded reflector of FIG. 3E taken along line 3 F- 3 F.
[0017] FIG. 4 is an isometric view of a deep submersible light incorporating an embodiment of the present invention.
[0018] FIG. 5 is a section view of the light of FIG. 4 taken along line 5 - 5 .
[0019] FIG. 6A is an enlarged portion of FIG. 5 illustrating details of the LED light head of the light of FIG. 4 .
[0020] FIG. 6B is an enlargement of the portion of FIG. 6A circled in phantom lines illustrating details of the high pressure puck sub-assembly of the light of FIG. 4 .
[0021] FIGS. 7A , 7 B, and 7 C are similar sectional views illustrating the range of motion of the pistoning front window of the light of FIG. 4 .
[0022] FIG. 8 is an exploded view of the light of FIG. 4 illustrating its thermal sensor.
[0023] FIG. 9 is a block diagram of the LED driver circuit of the light of FIG. 4 .
[0024] FIGS. 10A and 10B illustrate the manner in which the prior art light fixture of FIG. 1 can be retrofitted with the LED light head that forms a portion of the light of FIG. 4 .
[0025] FIG. 11 is a section view illustrating an alternate embodiment of the present invention in which the interior window centering O-ring is replaced by a spring engaging the perimeter of the window.
[0026] FIG. 12 is a section view illustrating an alternate embodiment of the present invention in which the interior window centering O-ring is replaced by six short springs located on the reflector.
[0027] FIG. 13 is an exploded view illustrating construction details of the embodiment of FIG. 12 .
[0028] FIG. 14 is an isometric view illustrating the light head and retaining collar of the FIG. 4 embodiment fitted to an alternate embodiment of the back housing and light mount.
[0029] FIG. 15 is a section view taken along line 15 - 15 of FIG. 14 .
[0030] FIG. 16 is a section view rotated ninety degrees relative to FIG. 15 .
[0031] FIG. 17 illustrates an alternate embodiment of the light head of the FIG. 4 embodiment, mounted to the back housing illustrated in FIG. 14 .
[0032] FIG. 18 is a section view taken along line 18 - 18 of FIG. 17 .
[0033] FIG. 19 is a section view rotated ninety degrees relative to FIG. 18 .
[0034] FIGS. 20A , 20 B, 20 C and 20 D illustrate four alternate miniature reflector shapes for redirecting the edge light of the LEDs.
[0035] FIGS. 21A , 21 B, 21 C and 21 D illustrate in diagrammatic fashion the resultant light patterns from the four alternate miniature reflector shapes embodied in FIGS. 20A , 20 B, 20 C and 20 D, respectively.
[0036] FIG. 22 is a section view of an alternate embodiment of a deep submersible light in accordance with the present invention illustrating the use of a piggyback circuit board to dim the light output of the LED driver board by external control.
[0037] FIG. 23 is an isometric view of an alternate embodiment of a deep submersible light in accordance with the present invention incorporating a cast soft elastomeric window and an in-line driver circuit.
[0038] FIG. 24 is a section view of the light of FIG. 23 taken along line 24 - 24 .
[0039] FIG. 25 is an enlarged exploded section view of the light head assembly of the light of FIG. 23 .
[0040] FIG. 26A is an alternate embodiment similar to the light of FIG. 23 in which the shape of the cast soft elastomeric window blends to match the adjacent hydrodynamic shape of an underwater control surface of a deep submersible vehicle.
[0041] FIG. 26B is a section view of FIG. 26A taken along line 26 B- 26 B.
[0042] FIG. 27 is a partially exploded view of FIG. 26
[0043] FIG. 28A is an alternate embodiment similar to the light of FIG. 26A .
[0044] FIG. 28B is a section view of FIG. 28A taken along line 28 B- 28 B.
[0045] FIGS. 29A and 29B illustrate an alternate embodiment of the LED/reflector sub-assembly for the light of FIG. 4 .
[0046] FIG. 30 is a section view of the alternate light head embodiment for the light of FIG. 4 .
DETAILED DESCRIPTION OF EMBODIMENTS
[0047] The entire disclosure of co-pending U.S. patent application Ser. No. 12/036,178 filed Feb. 22, 2008 of Mark S. Olsson et al. is hereby incorporated by reference. That application is entitled “LED Illumination System and Methods of Fabrication.”
[0048] FIGS. 3C , 3 D, 3 E and 3 F illustrate structure that is incorporated into the deep submersible light of FIGS. 4 and 5 . More particularly, FIG. 3C illustrates an array of eighteen Cree XRE high brightness LEDs 302 combined with a metal core printed circuit board (MCPCB) 332 in an assembly 330 , which may referred to as a light engine. FIG. 3D illustrates a section view of the assembly 330 . FIG. 3E illustrates a metalized molded plastic multiple-reflector plate 340 , which is designed such that the light-emitting parts of the LEDs 302 ( FIG. 3C ) protrude through the reflector openings when aligned for placement above the LED/MCPCB assembly 330 ( FIG. 3C ). FIG. 3F illustrates a section view of the multiple-reflector plate 340 .
[0049] Referring to FIGS. 4 and 5 , in accordance with an embodiment of the present invention a deep submersible light 402 includes a cylindrical light head sub-assembly 502 , a hemispherical back shell 206 , a cylindrical cowl 504 , a bulkhead connector 210 , an electronic LED driver 506 , a miniature candelabra lamp screw base 508 , and a mount 208 . The volume inside the back shell 206 is protected from high exterior ambient water pressure, e.g. that which would be encountered at depths of 1,400 meters and greater. At 1,400 meters, the ambient water pressure is approximately 2,000 PSI. The light head subassembly 502 functions as a pressure resistant forward bulkhead, while the bulkhead connector 210 seals the rear of the back shell 206 . The screw base 508 adapts the screw socket plug of the bulkhead connector 210 to allow wires to pass to the electronic LED driver 506 . The interior volume of the light head sub-assembly 502 is filled with an optically transparent dielectric fluid, grease, or gel 510 in sufficient volume to allow for volumetric change due to a combination of the cold temperature and high pressure of the deepest ocean depths. Examples of suitable fluids include Dow Corning 200, Dow 705, Dow 710, and 3M FC-70. Optical Gels include Dow Optical Coupling Gel, OE-4000. Optical Greases that are suitable include Saint-Gobain BC-630.
[0050] Referring to FIG. 6A the LED light head sub-assembly 502 includes a generally cylindrical ribbed metal body 602 , a cylindrical pistoning transparent plastic window 604 extending across and sealing one end of the metal body 602 , a radially sealing O-ring 614 , two longitudinal centering O-rings 612 and 616 , and an upper spiral retaining ring 610 to hold the window 604 in position. The metal body 602 defines a hollow interior in which the LED/MCPCB sub-assembly 330 is mounted. The plastic window 604 is substantially rigid and may be made from Acrylic, polycarbonate, Trogamid, or other materials combining suitable qualities for use at deep underwater depths. Alternatively, the window 604 could be made of various suitable non-plastic transparent materials such as glass and sapphire. The window 604 is sealed using the single radial O-ring 614 seated in a groove cut into the metal body 602 . The window 604 is capable of moving axially relative to the longitudinal center line of the generally cylindrical light head sub-assembly 502 as the ambient water pressure varies during descent and ascent of a deep submersible vehicle carrying the light of FIG. 4 . The forward and rearward edges of the window 604 are beveled where they engage the centering O-rings 612 and 616 to facilitate such longitudinal or reciprocal pistoning movement of the window 604 . The O-ring 614 provides a water-tight seal between the window 604 and the metal body 602 . This water-tight seal need not be provided by an O-ring, but could instead be provided by other means including a bellows or a flat clamp gasket.
[0051] The reciprocal transparent window 604 allows light generated by the LEDs 302 ( FIG. 3C ) to pass through the window outward and ambient water pressure to pass inward, thus pressure compensating the LEDs 302 ( FIG. 3C ). In fluid mechanics, “ambient pressure” refers to the pressure of the surrounding fluid medium, either gas or liquid, which comes into contact with an apparatus. As a submarine dives deeper into the sea, pressure increases due to the increased weight of water above it. This increase in pressure can cause materials to compress if exposed to that pressure. Systems can either be built strong enough to resist that pressure, and thus “pressure protected”, or allowed to equalize to that pressure, and thus “pressure compensated.” In the embodiment of this invention, the fluid, gel, or grease is the material that compresses according to pressure, and the reciprocal transparent window 604 is the mechanism that allows the volume to change as necessary. Since the fluid, gel, or grease is in direct contact with the LEDs 302 ( FIG. 3C ), the ambient pressure is thereby transmitted directly to the LEDs 302 ( FIG. 3C ).
[0052] Referring still to FIG. 6A , the LED/MCPCB sub-assembly 330 , is thermally connected to a thick rear wall of the generally cylindrical metal body 602 using a Phase Change Material (PCM) 622 , such as Laird Technologies T-pcm 583, and restrained and clamped by a centering collar 620 and a wave spring 618 . By way of example, the metal body 602 may be made of 6061-T6 aluminum, with a Type III hard anodize conversion coating on its interior surface that provides an additional electrical isolation layer between the metal core board and the aluminum housing. The multiple-reflector plate 340 is held in position by a hex nut 624 . The construction of the high pressure puck sub-assembly 630 is described below in conjunction with FIG. 6B . The interior open volume surrounding the LED/MCPCB sub-assembly 330 is filled with an optically clear, dielectric fluid, gel, or grease 510 . The two longitudinal centering O-rings 612 and 616 are useful in keeping the pistoning clear plastic window 604 axially aligned down the center of the cylindrical interior of the metal body 602 , eliminating the danger of tipping and wedging. A large thickness-to-bore diameter ratio would otherwise be needed.
[0053] Referring still to FIG. 6A , a seal screw 606 extends through a bore in the center of the window 604 and allows for installation of the window 604 and subsequent fluid filling during final assembly. The screw 606 is screwed into a threaded segment of a through-bore formed in the center of the window 604 . An unthreaded outer extension of the through-bore in the window 604 is sealed beneath a cast-in-place, or injection molded and pressed in place, clear elastomeric plug 608 . Alternatively, a pair of seal screws (not illustrated) may be inserted through bores in opposite sides of the metal body 602 , to permit fluid insertion and air extraction.
[0054] Referring to FIG. 6B , the high pressure puck sub-assembly 630 includes a high pressure puck 642 made of high strength thermosetting epoxy with molded insert electrical contacts 644 , installed in a matching bore machined or otherwise formed in the metal body 602 . The electrical contacts 644 are made with pins on one end and sockets on the other. The sockets are positioned to face the LED/MCPCB sub-assembly 330 . The puck 642 is sealed by use of a radial O-ring 638 , centered between two Teflon® back-up rings 636 and 640 . The rings 636 and 640 are squeezed into position by an upper O-ring 634 , which itself is held in position by a spiral retaining ring 632 . Electrical pins 652 pass from the LED/MCPCB sub-assembly 330 , through an insulating centering plate 654 , and into the electrical sockets in the puck 642 . The electrical pins 652 are held against the LED/MCPCB sub-assembly 330 and prevented from rotating by an insulating top cap 650 . This stack-up is sandwiched together by use of a through-bolt 648 , and a hex nut 646 . The multiple-reflector plate 340 is then added to this stack-up and held by a hex nut 624 .
[0055] FIGS. 7A , 7 B and 7 C illustrates the range of motion of the pistoning transparent plastic window 604 . FIG. 7A illustrates the position of the window 604 at average sea level conditions (72 degrees F. at 14.70 psi.), centered in the bore or hollow interior of the light head sub-assembly 502 with a starting volume of dielectric fluid, grease, or gel 510 . FIG. 7B . illustrates the position of the window 604 centered in the bore of the light head sub-assembly 502 after it has moved axially forward as heat generated by the illumination of the LEDs causes the dielectric fluid, grease, or gel 510 inside the light to expand. FIG. 7C illustrates the position of the window 604 centered in the bore of the light head sub-assembly 502 after it has moved axially rearward due to the influence of deep ocean ambient high water pressure and cold temperatures (40 degrees F. at 10,000 psi) on the dielectric fluid, grease, or gel 510 .
[0056] FIG. 8 is an exploded view of the deep submersible light 402 showing the thermal sensor 802 on the electronic LED driver 506 and thermal conductive pad 804 that thermally connects the thermal sensing component of the LED electronic driver 506 to the light head sub-assembly 502 .
[0057] FIG. 9 is a block diagram of the LED driver circuit illustrating the power flow from an AC/DC power source 902 , through input filter elements 904 (over voltage clamp, current limit, and inrush current limit), to an input voltage rectifier 906 , switch mode current regulator 908 , to an LED Light engine 910 . The LED driver circuit further includes circuit feedback and self-regulating control elements in the form of a temperature monitor 912 to test for overheating, a dimming interface 914 to reduce heat by lowering power, and an AC line monitor 916 to test for under voltage conditions.
[0058] An important aspect of the embodiment of FIG. 4 is that its LED light head sub-assembly 502 can be retrofitted into the body 206 of existing prior art Multi SeaLite® lights 102 manufactured for many years by DeepSea Power & Light, Inc., the assignee of the subject application, in place of the halogen light head sub-assembly, creating the LED Multi SeaLite® 402 . This retrofit capability is illustrated by the side-by-side views of FIGS. 10A and 10B .
[0059] FIG. 11 illustrates an alternate embodiment 1102 of light head sub-assembly 502 ( FIG. 5 ) in which the interior window centering O-ring 616 ( FIG. 6 ) is replaced by a single coil or wave spring 1104 that engages the rear face of the window 604 and rests on an internal land or flange of the metal body 602 .
[0060] FIG. 12 illustrates an alternate embodiment 1202 of light head sub-assembly 502 ( FIG. 5 ) in which the interior window centering O-ring 616 ( FIG. 6 ) is replaced by six compression springs 1204 that press on the multiple-reflector plate 340 , and push against the rear side of the window 604 . The springs 1204 provide uniform force to keep the window 604 aligned axially within the bore or hollow interior of the metal body 602 .
[0061] The exploded view of 1202 in FIG. 13 further illustrates the relationship of the window 604 , the six compression springs 1204 , the multiple-reflector plate 340 , a hex nut 646 , and the metal body 602 . In the event of maximum inward movement of the window 604 , the hex nut 646 fits within a recess in the backside of the window 604 , precluding mechanical interference.
[0062] Referring to FIG. 14 in an alternate embodiment 1402 a back housing 1404 replaces the back shell 206 ( FIG. 2 ). The light is centered in a U-shaped light mount 1412 using a shoulder bolt 1408 , and secured with two cap screws 1410 . FIG. 15 is a section view taken along line 15 - 15 of FIG. 14 , and illustrates the increased volume of 1402 with the larger back housing 1404 , permitting more LED drive circuitry to be placed inside the same. FIG. 16 is a section view of the alternate embodiment 1402 rotated ninety degrees about the axial centerline relative to FIG. 15 . FIG. 16 illustrates a fiber or rubber washer 1602 that functions as a friction element of the mounting mechanism, allowing the light mount 1412 to positively clamp to the back housing 1404 , with all three structures held in alignment by the shoulder bolt 1408 .
[0063] FIG. 17 illustrates an alternate embodiment 1702 in which the light head 1704 is mounted to the back housing 1404 . The embodiment 1702 uses the same light mount 1412 as the embodiment 1402 ( FIG. 14 ). FIG. 18 is a section view of the embodiment 1702 of FIG. 17 along the line 18 - 18 , illustrating the alternate embodiment 1702 , composed of the light head 1704 mounted to the back housing 1404 . An O-ring 1802 is used to keep sea water and debris out of the mating threads to prevent corrosion, fouling, and galling. FIG. 19 is a section view of the alternate embodiment 1702 rotated ninety degrees about the axial centerline relative to FIG. 18 , showing details of the same light mount 1412 as the embodiment 1402 ( FIG. 14 ).
[0064] FIG. 20A . illustrates an alternate miniature smooth parabolic spot pattern reflector 2000 for use with the multiple-reflector plate 340 ( FIG. 3 ). The resultant light pattern with substantially parallel rays is illustrated in FIG. 21A .
[0065] FIG. 20B illustrates an alternate miniature parabolic flood pattern reflector 2002 with circumferentially extending convex or concave stepped rings 2004 for use with the multiple-reflector plate 340 ( FIG. 3 ). The resultant light pattern with spread rays is illustrated in FIG. 21B .
[0066] FIG. 20C illustrates an alternate miniature parabolic flood pattern reflector 2006 with micropeened surface made up of a plurality of miniature convex or concave surfaces 2008 for use with the multiple-reflector plate 340 ( FIG. 3 ). The resultant light pattern with spread rays is illustrated in FIG. 21C .
[0067] FIG. 20D illustrates an alternate miniature isoradiant flood pattern reflector 2010 for use with the multiple-reflector plate 340 ( FIG. 3 ). A Cree four-die MCE LED 2012 is mounted so that its transparent dome-shaped lens element 2014 extends within the reflector cavity, and the four dies are at an optimal position with respect to the focal point of the reflector, either congruent with or offset from said focal point. The resultant even flood light pattern is illustrated in FIG. 21D .
[0068] By way of example, the Cree four die MCE LED 2012 are illustrated in FIGS. 21A , 21 B, 21 C, and 21 D mounted in its operative position relative to the reflectors 2000 , 2002 , 2006 , and 2010 respectively, with resultant light patterns.
[0069] FIG. 22 illustrates the use of a piggyback circuit board 2202 with the alternate embodiment 1702 to dim the light output of the electronic LED driver 506 by external control. The modular piggyback circuit board 2202 may be selected based on the type of dimming interfaces encountered, including isolated and non-isolated control voltage (0-10 VDC), current loop (4-20 mA), pulse width modulated (PWM), and serial communications.
[0070] FIG. 23 illustrates an alternate embodiment 2302 of LED light head sub-assembly 502 ( FIG. 5 ) that incorporates a cast soft elastomeric transparent window 2306 for pressure compensation. The light illustrated in FIG. 23 also incorporates an in-line LED driver assembly 2304 , wherein a circuit board is encapsulated within a cylindrical elastomeric housing providing similar pressure compensation.
[0071] FIG. 24 is a section view of FIG. 23 along the lines 24 - 24 , showing the alternate embodiment of the light head 2302 , composed of a metal housing 2402 that encloses the LED/MCPCB sub-assembly 330 that is thermally connected to the metal housing 2402 using a phase change material (PCM) 622 . Machine screws 2506 (illustrated in FIG. 25 ) hold the LED/MCPCB sub-assembly 330 to the metal housing 2402 . A center screw 2508 (shown in FIG. 25 ) holds the multi-cavity reflector plate 340 over the LED/MCPCB sub-assembly 330 . An optically transparent, high dielectric, non-hygroscopic, soft durometer, castable elastomer 2306 fills all voids. The two-part castable elastomer 2306 preferably has a low viscosity and a one-hour minimum pot life during its working phase in order to fill every small crevice and void. After it cures, the compliance of this material to external pressure provides the means of compensation to the LEDs. One suitable commercially available material for the elastomer 2306 is NuSil LS-6143. The LED driver assembly 2304 is shown remote from the LED light head sub-assembly 2302 , separated by an appropriate length of underwater electrical cable 2408 , here shown at minimum length. The cable entry to the LED light head 2302 is sealed with a low cost compression fitting 2406 , such as a Heyco Liquid Tight Cordgrips (p/n M3210). The LED driver assembly 2304 is comprised of an LED driver electronics 2410 encapsulated by a thermally conductive, non-hygroscopic, soft durometer castable elastomer 2412 , which has no requirement for optical clarity. One suitable commercially available material for the elastomer 2412 is Dow Corning Thermally Conductive Elastomer SYLGARD Q3-6632. An additional length of underwater electrical cable 2414 connects the LED driver electronics 2410 to electrical power. The cables 2408 and 2414 are cast in place and sealed watertight within the body of 2304 by the castable elastomer 2412 , requiring no additional seal fitting such as 2406 . The principal advantage of the embodiment of FIGS. 23 and 24 is that the light head is placed where light is needed, but minimum profile is required, such as the inside wrist of a vehicle manipulator (robotic arm) on a deep submersible vehicle.
[0072] FIG. 25 further illustrates the mounting relationship of the components of the LED light head assembly 2302 and the metal housing 2402 , LED/MCPCB sub-assembly 330 , phase change material (PCM) 622 , held by three machine screws 2506 , multiple-reflector plate 340 , held by machine screw 2508 , and the optically clear, high dielectric, non-hygroscopic, soft durometer, castable elastomer window 2306 . A rib extends around the perimeter to help seal and retain the window 2306 . The compression fitting 2406 is shown as part of the LED light head assembly 2302 .
[0073] FIG. 26A illustrates an alternate embodiment 2602 of castable elastomer window 2306 ( FIG. 23 ). The shape of the cast soft elastomeric window 2604 is blended to match or conform to the adjacent hydrodynamic shape of a control surface 2610 of an underwater vehicle. The control surface 2610 could either be a fixed dive plane, active dive plane, or a rudder. The LED driver assembly 2304 and underwater electrical cable 2408 are shown recessed within the leading edge of the dive plane.
[0074] FIG. 26B is a section view of 2602 in FIG. 26A taken along line 26 B- 26 B, showing the LED driver assembly 2304 remote from the LED light engine 2606 , separated by an appropriate length of underwater electrical cable 2408 , here shown at minimum length, and sealed through a low cost compression fitting 2406 . This allows placement of the driver electronics 2410 at any distance convenient to the submarine builder. The elastomeric window 2604 is shown as a functional mechanical part of the control surface 2610 . An appropriate length of underwater electrical cable 2414 connects the LED driver assembly 2304 to electrical power.
[0075] FIG. 27 illustrates a partially exploded view of the castable window 2604 and LED light engine 2606 removed from its recessed pocket in the control surface 2610 . Though shown separated, the castable window 2604 fully encapsulates the LED light engine 2606 . LED driver assembly 2304 with underwater electrical cables 2408 and 2414 , is shown removed from the recess inside the leading edge of the control surface 2610 , and separated from the compression fitting 2406 .
[0076] FIG. 28A is an alternate embodiment similar to 2602 of FIG. 26A , showing the cast soft elastomeric window 2604 blended to match or conform to the adjacent hydrodynamic shape of a control surface 2610 of an underwater vehicle. The LED driver assembly 2304 and underwater electrical cable 2414 are shown extending from the recess pocket within the leading edge of the control surface 2610 . An appropriate length of underwater electrical cable 2414 connects the LED driver assembly 2304 to electrical power.
[0077] FIG. 28B is a section view of FIG. 28A taken along line 28 B- 28 B, showing the LED driver assembly 2304 remote from the LED light engine 2606 , separated by an appropriate length of underwater electrical cable 2408 , here shown at minimum length, bonded to an underwater in-line connector pair 2608 rated for depth and power. An in-line underwater electrical connector 2608 allows simple assembly of the LED driver assembly 2304 and LED light engine 2606 , and allows placement of the LED driver assembly 2304 at any distance convenient to the submarine builder. The elastomeric window 2604 is shown as a functional mechanical part of the control surface 2610 . An appropriate length of underwater electrical cable 2414 connects the LED driver assembly 2304 to electrical power.
[0078] FIG. 29A illustrates the assembly of an LED light engine subassembly 2902 using LED/MCPCB sub-assembly 330 , electrical pins 652 ( FIG. 6 ), insulating centering plate 654 ( FIG. 6 ), insulating top cap 650 ( FIG. 6 ), through-bolt 648 ( FIG. 6 ), and a hex nut 646 ( FIG. 6 ). The multiple-reflector plate 340 is then added to this stack-up and held by a hex nut 624 ( FIG. 6 ). This entire sub-assembly is then encapsulated in an optically clear, high dielectric, non-hygroscopic, soft durometer castable elastomer 2306 , which fills all voids between the front of LED light engine 330 , and the entirety of the multiple-reflector plate 340 . The back of the LED light engine 330 is left bare, as is its edge, and a small land area on the front for final assembly in the same manner illustrated in FIG. 6A . The elastomer 2306 provides pressure compensation, reduces the volume of compensating dielectric fluid, grease, or gel 510 ( FIG. 5 ) required, and eliminates any undesirable chemical affects of the compensating dielectric fluid, grease, or gel 510 ( FIG. 5 ) on the LED dies 306 ( FIG. 3 ).
[0079] FIG. 29B is a section view of the light engine subassembly 2902 of FIG. 29A taken along line 29 B- 29 B. This subassembly is shown in a full light assembly in FIG. 30 .
[0080] FIG. 30 illustrates an alternate embodiment of the invention 3002 that incorporates the cast light engine sub-assembly 2902 as part of a hybrid pressure compensation technique. The cast light engine sub-assembly 2902 is constrained in the same manner illustrated in FIG. 6A . A pressure compensating dielectric fluid, grease, or gel 510 fills the remaining void between the cast light engine sub-assembly 2902 , and the pistoning clear plastic window 604 .
[0081] While several embodiments of deep submersible lights and light head assemblies have been described and illustrated in detail, it should be apparent to those skilled in the art that our invention can be modified in arrangement and detail. For example, other solid state sources of illumination could be used besides LEDs. The relatively thick, substantially rigid window 604 could be replaced with a thinner flexible, but otherwise hard window, as taught in the Ser. No. 12/036,178 application incorporated by reference above. Therefore, the protection afforded our invention should only be limited in accordance with the scope of the following claims. | A deep submersible light may include a body defining a hollow interior and a solid state light source such as a plurality of high brightness LEDs mounted in the interior of the body. A transparent window may be mounted over the LEDs. The space between the transparent window and the LEDs may be filled with an optically transparent fluid, gel, or grease, which allows light to pass through and ambient water pressure to pass in, thus pressure compensating the LEDs by allowing them to see ambient water pressure. The transparent window may be mounted in the body for reciprocation in both a forward direction and a rearward direction to accommodate volumetric changes in the compensating fluid, gel, or grease caused by changes in temperature and water pressure as the manned or remotely piloted submarine travels from the sea surface to deep ocean depths. | 5 |
BACKGROUND OF THE INVENTION
[0001] Technical Field
[0002] The present technique relates to a current detection device and a semiconductor device.
[0003] Background Art
[0004] Recent years have seen the continued development of semiconductor devices known as Insulated Gate Bipolar Transistors (IGBTs), and Intelligent Power Modules (IPMs) containing driver circuits for driving IGBTs.
[0005] An IPM is a power semiconductor module for power switching, and supplies power to powered electronic products such as motors, robots, inverters, and converters. An IPM also detects current flowing in a semiconductor element and protects the semiconductor element on the basis of the detected current information.
[0006] As a conventional current detection technique, a technique has been proposed in which the direction of an output current flowing in a power semiconductor device equipped with a sense function is detected and outputted to a CPU. Then, a gain amount, offset amount, and the like of current detection properties are adjusted by a setting signal outputted from the CPU in accordance with the direction of the output current (Patent Document 1).
RELATED ART DOCUMENT
Patent Document
[0000]
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2012-90499
SUMMARY OF THE INVENTION
[0008] A typical configuration for current detection has a current detection unit provided on the main line of the IPM or on a bus bar provided in the main line, such that a load current is detected.
[0009] However, according to such a configuration, the current detection unit detects a main current, which is a large current flowing in the main line, as the load current. If a current transformer, for example, is accordingly used as the current detection unit, the size of the unit will increase. This leads to a problem in that the scale of the device will increase as well.
[0010] Having been achieved in light of such circumstances, it is an object of the present invention to provide a current detection device and a semiconductor device that achieve a reduction in the scales of the devices. Accordingly, the present invention is directed to a scheme that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
[0011] Additional or separate features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
[0012] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, in one aspect, the present disclosure provides an inverter circuit having a current detection circuitry, including: a pair of DC input nodes configured to receive a DC voltage: a main bridge circuit connected between the pair of DC input nodes, the main bridge circuit converting the received DC voltage to a primary AC current so as to output the primary AC current through an output terminal to be connected to a load; a supplementary bridge circuit connected in parallel to the main bridge circuit between the pair of DC input nodes for calculating an amount of the AC current outputted by the main bridge circuit, the supplementary bridge circuit having a circuit configuration identical to that of the main bridge circuit with smaller circuit parameters in at least some of constituent circuit elements so as to generate a detection-use AC current that is a prescribed fraction of said AC current outputted by the main bridge circuit, an output line of the supplementary bridge circuit carrying the detection-use AC current being connected to the output terminal of the main bridge circuit to supplement the primary AC current; and a current detector disposed on said output line of the supplementary bridge circuit to detect the detection-use AC current and output a signal corresponding to the detected detection-use AC current that is said prescribed fraction of the primary AC current from the main bridge circuit.
[0013] In another aspect, the present disclosure provides a three-phase semiconductor inverter circuit having a current detection circuitry, including: a pair of DC input nodes configured to receive a DC voltage; a U-phase main bridge circuit connected between the pair of DC input nodes, the U-phase main bridge circuit converting the received DC voltage to a primary U-phase AC current so as to output the primary U-phase AC current through a U-phase output terminal to be connected to a load; a U-phase supplementary bridge circuit connected in parallel to the U-phase main bridge circuit between the pair of DC input nodes for calculating an amount of the U-phase AC current outputted by the U-phase main bridge circuit, the U-phase supplementary bridge circuit having a circuit configuration identical to that of the U-phase main bridge circuit with smaller circuit parameters in at least some of constituent circuit elements so as to generate a detection-use U-phase AC current that is a prescribed fraction of said U-phase AC current outputted by the U-phase main bridge circuit, an output line of the U-phase supplementary bridge circuit carrying the detection-use U-phase AC current being connected to the U-phase output terminal of the U-phase main bridge circuit to supplement the primary U-phase AC current; a U-phase current detector disposed on said U-phase output line of the U-phase supplementary bridge circuit to detect the detection-use U-phase AC current and output a U-phase signal corresponding to the detected detection-use U-phase AC current that is said prescribed fraction of the primary U-phase AC current from the main bridge circuit; a V-phase main bridge circuit connected between the pair of DC input nodes, the V-phase main bridge circuit converting the received DC voltage to a primary V-phase AC current so as to output the primary V-phase AC current through a V-phase output terminal to be connected to the load; a V-phase supplementary bridge circuit connected in parallel to the V-phase main bridge circuit between the pair of DC input nodes for calculating an amount of the V-phase AC current outputted by the V-phase main bridge circuit, the V-phase supplementary bridge circuit having a circuit configuration identical to that of the V-phase main bridge circuit with smaller circuit parameters in at least some of constituent circuit elements so as to generate a detection-use V-phase AC current that is a prescribed fraction of said V-phase AC current outputted by the V-phase main bridge circuit, an output line of the V-phase supplementary bridge circuit carrying the detection-use V-phase AC current being connected to the V-phase output terminal of the V-phase main bridge circuit to supplement the primary V-phase AC current; a V-phase current detector disposed on said V-phase output line of the V-phase supplementary bridge circuit to detect the detection-use V-phase AC current and output a V-phase signal corresponding to the detected detection-use V-phase AC current that is said prescribed fraction of the primary V-phase AC current from the main bridge circuit; a W-phase main bridge circuit connected between the pair of DC input nodes, the W-phase main bridge circuit converting the received DC voltage to a primary W-phase AC current so as to output the primary W-phase AC current through a W-phase output terminal to be connected to the load; a W-phase supplementary bridge circuit connected in parallel to the W-phase main bridge circuit between the pair of DC input nodes for calculating an amount of the W-phase AC current outputted by the W-phase main bridge circuit, the W-phase supplementary bridge circuit having a circuit configuration identical to that of the W-phase main bridge circuit with smaller circuit parameters in at least some of constituent circuit elements so as to generate a detection-use W-phase AC current that is a prescribed fraction of said W-phase AC current outputted by the W-phase main bridge circuit, an output line of the W-phase supplementary bridge circuit carrying the detection-use W-phase AC current being connected to the W-phase output terminal of the W-phase main bridge circuit to supplement the primary W-phase AC current; and a W-phase current detector disposed on said W-phase output line of the W-phase supplementary bridge circuit to detect the detection-use W-phase AC current and output a W-phase signal corresponding to the detected detection-use W-phase AC current that is said prescribed fraction of the primary W-phase AC current from the main bridge circuit.
[0014] The U-phase bridge circuit includes a U-phase main bridge circuit that outputs a first U-phase current through a first U-phase output line connected to a load, and a U-phase current detection bridge circuit that is connected in parallel to the U-phase main bridge circuit and that outputs a second U-phase current through a second U-phase output line connected at one end to the first U-phase output line.
[0015] The V-phase bridge circuit includes a V-phase main bridge circuit that outputs a first V-phase current through a first V-phase output line connected to the load, and a V-phase current detection bridge circuit that is connected in parallel to the V-phase main bridge circuit and that outputs a second V-phase current through a second V-phase output line connected at one end to the first V-phase output line.
[0016] The W-phase bridge circuit includes a W-phase main bridge circuit that outputs a first W-phase current through a first W-phase output line connected to the load, and a W-phase current detection bridge circuit that is connected in parallel to the W-phase main bridge circuit and that outputs a second W-phase current through a second W-phase output line connected at one end to the first W-phase output line.
[0017] The U-phase current detection unit is disposed in the second U-phase output line and detects the second U-phase current. The V-phase current detection unit is disposed in the second V-phase output line and detects the second V-phase current. The W-phase current detection unit is disposed in the second W-phase output line and detects the second W-phase current.
[0018] The present invention makes it possible to reduce the scale of a device. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a diagram illustrating an example of the configuration of a current detection device.
[0020] FIG. 2 is a diagram illustrating an example of the configuration of a conventional inverter constituted by an IPM.
[0021] FIG. 3 is a diagram illustrating a current transformer.
[0022] FIG. 4 is a diagram illustrating an example of the configuration of an IPM.
[0023] FIG. 5 is a diagram illustrating a correspondence relationship between a surface area ratio and a current ratio.
[0024] FIG. 6 is a diagram illustrating a correspondence relationship between a surface area ratio and a current ratio.
[0025] FIG. 7 is a diagram illustrating a correspondence relationship between a surface area ratio and a current ratio.
[0026] FIG. 8 is a diagram illustrating the configuration of a variation on a current detection bridge circuit.
DETAILED DESCRIPTION OF EMBODIMENTS
[0027] Embodiments will be described hereinafter with reference to the drawings.
[0028] FIG. 1 is a diagram illustrating an example of the configuration of a current detection device (i.e., an inverter circuit having a current detection circuitry). A current detection device 1 includes a bridge circuit 1 a (a first bridge circuit or main bridge circuit), a bridge circuit 1 b (a second bridge circuit or supplementary bridge circuit), a current detection unit 1 c (current detector), and driver circuits 30 - 1 and 30 - 2 .
[0029] The bridge circuit 1 a is a main bridge circuit that supplies current to a load M, and includes transistors Tr 1 a and Tr 2 a and diodes D 1 a and D 2 a . The bridge circuit 1 b is a bridge circuit for detection current in addition to supplying current to the load M, and includes transistors Tr 1 b and Tr 2 b and diodes D 1 b and D 2 b.
[0030] The bridge circuit 1 a outputs a current Im (a first current or primary AC current) through an output line Lm (a first output line) connected to the load M. The bridge circuit 1 b is connected in parallel to the bridge circuit 1 a , and outputs a current Is (a second current or detection-use AC current) through an output line Ls (a second output line) connected at one end to the output line Lm. The current detection unit 1 c is disposed in the output line Ls and detects the current Is.
[0031] With respect to the connection relationships between the elements, a collector of the transistor Tr 1 a is connected to a collector of the transistor Tr 1 b , cathodes of the diodes D 1 a and D 1 b , and a P terminal. The P terminal corresponds to a power source terminal, for example.
[0032] An emitter of the transistor Tr 2 a is connected to an emitter of the transistor Tr 2 b , anodes of the diodes D 2 a and D 2 b , and an N terminal. The N terminal corresponds to a GND terminal, for example.
[0033] Meanwhile, an emitter of the transistor Tr 1 a , a collector of the transistor Tr 2 a , an anode of the diode D 1 a , and a cathode of the diode D 2 a are connected to an output terminal OUT through the output line Lm, and the load M is connected to the output terminal OUT.
[0034] Furthermore, an emitter of the transistor Tr 1 b , a collector of the transistor Tr 2 b , an anode of the diode D 1 b , and a cathode of the diode D 2 b are connected to the output line Ls. One end of the output line Ls is connected to a node n on the output line Lm, and the current detection unit 1 c is inserted into the output line Ls.
[0035] Bases of the transistors Tr 1 a and Tr 1 b are connected to an output terminal of the driver circuit 30 - 1 , and bases of the transistors Tr 2 a and Tr 2 b are connected to an output terminal of the driver circuit 30 - 2 .
[0036] Here, a current transformer is employed as the current detection unit 1 c . The current transformer is inserted onto the output line Ls, and current information of the current Is detected by the current transformer (i.e., a signal corresponding to the detected current Is) is inputted to, for example, a host control unit (controller) 4 (the structure of the current transformer will be described later with reference to FIG. 3 ).
[0037] On the basis of the current information, the control unit 4 generates drive control signals s 1 and s 2 for controlling switching of the transistors, and sends those signals to the driver circuits 30 - 1 and 30 - 2 , respectively. The driving of the high-side transistor Tr 1 a in the bridge circuit 1 a and the high-side transistor Tr 1 b in the bridge circuit 1 b is controlled by the same high-side driver circuit 30 - 1 .
[0038] Meanwhile, the driving of the low-side transistor Tr 2 a in the bridge circuit 1 a and the low-side transistor Tr 2 b in the bridge circuit 1 b is controlled by the same low-side driver circuit 30 - 2 .
[0039] Additionally, a surface area ratio between a first active surface area of first semiconductor devices (the transistors Tr 1 a and Tr 2 a and the diodes D 1 a and D 2 a ) included in the bridge circuit 1 a and a second active surface area of second semiconductor devices (the transistors Tr 1 b and Tr 2 b and the diodes D 1 b and D 2 b ) included in the bridge circuit 1 b is equal to a current ratio between the current Im and the current Is. Accordingly, the second active surface area is made smaller than the first active surface area and the current Im is made lower than the current Is (correspondence relationships between the surface area ratio and the current ratio will be described later with reference to FIGS. 5 to 7 ).
[0040] Thus the current detection device 1 is configured such that the bridge circuit 1 b for detection current, which is constituted of the second semiconductor devices whose current capacities are lower than the first semiconductor devices in the bridge circuit 1 a , is connected in parallel to the bridge circuit 1 a , and detects the current Is (<the current Im) flowing in the bridge circuit 1 b . This makes it possible to reduce the size of the current detection unit 1 c that detects the current Is, which in turn makes it possible to reduce the scale of the device.
[0041] A conventional current detection configuration and issues therewith to be solved will be described next, before going into detail about the technique according to the present invention. First, the configuration of an IPM that detects current by having a current transformer inserted onto a main line thereof will be described.
[0042] FIG. 2 is a diagram illustrating an example of the configuration of a conventional inverter constituted by an IPM. This diagram illustrates a conventional configuration that detects current by having a current transformer inserted into a main line.
[0043] An inverter 100 includes an IPM 110 and a host controller 40 . The IPM 110 includes diodes D 1 to D 6 and D 11 to D 16 , a capacitor C 1 , and IGBTs 11 to 16 .
[0044] In the IPM 110 , the diodes D 1 to D 6 , which form a three-phase rectifying bridge circuit, the smoothing capacitor C 1 , the IGBTs 11 to 16 , which are semiconductor switches, and the diodes D 11 to D 16 are disposed between a high-voltage bus L 1 and a GND bus L 2 . Driver circuits 31 to 36 for driving the IGBTs 11 to 16 , respectively, are connected to the IGBTs 11 to 16 , respectively.
[0045] A load M is connected to output terminals OUT 1 to OUT 3 of the IPM 110 . The IPM 110 transforms a DC high voltage flowing in the bus L 1 into three-phase alternating current and supplies power to the load M from AC main lines La, Lb, and Lc.
[0046] The IPM 110 drives the load M by switching a current of an inductive load such as a motor on and off, and thus the diodes D 11 to D 16 , which are freewheeling diodes (FWDs), are connected to the IGBTs 11 to 16 in order to return the load current.
[0047] In other words, counter EMF is produced from the inductive load such as a motor the instant the IGBTs 11 to 16 turn off, and thus the load current at this time is returned by connecting the diodes D 11 to D 16 in reverse-parallel to the IGBTs 11 to 16 , respectively.
[0048] Connection relationships among the constituent elements will be described next. An anode of the diode D 1 is connected to an output end a 1 of an AC source A 0 and a cathode of the diode D 2 . An anode of the diode D 3 is connected to an output end a 2 of the AC source A 0 and a cathode of the diode D 4 . An anode of the diode D 5 is connected to an output end a 3 of the AC source A 0 and a cathode of the diode D 6 .
[0049] Meanwhile, cathodes of the diodes D 1 , D 3 , and D 5 , one end of the capacitor C 1 , collectors of the IGBTs 11 , 13 , and 15 , and cathodes of the diodes D 11 , D 13 , and D 15 are connected by the bus L 1 to a P terminal.
[0050] Furthermore, anodes of the diodes D 2 , D 4 , and D 6 , another end of the capacitor C 1 , emitters of the IGBTs 12 , 14 , and 16 , and anodes of the diodes D 12 , D 14 , and D 16 are connected by the bus L 2 to an N terminal.
[0051] Meanwhile, an emitter of the IGBT 11 is connected to an anode of the diode D 11 , a collector of the IGBT 12 , a cathode of the diode D 12 , and the output terminal OUT 1 . The output terminal OUT 1 is connected to the load M by the main line La.
[0052] An emitter of the IGBT 13 is connected to an anode of the diode D 13 , a collector of the IGBT 14 , a cathode of the diode D 14 , and the output terminal OUT 2 . The output terminal OUT 2 is connected to the load M by the main line Lb. Meanwhile, a current transformer CT 1 b is inserted into the main line Lb between the output terminal OUT 2 and the load M.
[0053] An emitter of the IGBT 15 is connected to an anode of the diode D 15 , a collector of the IGBT 16 , a cathode of the diode D 16 , and the output terminal OUT 3 . The output terminal OUT 3 is connected to the load M by the main line Lc. Meanwhile, a current transformer CT 1 c is inserted into the main line Lc between the output terminal OUT 3 and the load M.
[0054] The current transformers CT 1 b and CT 1 c are connected to the controller 40 . Drive control signals s 1 to s 6 from the controller 40 are connected to input terminals of the driver circuits 31 to 36 , respectively. Output terminals of the driver circuits 31 to 36 are connected to bases of the IGBTs 11 to 16 , respectively.
[0055] Here, the controller 40 generates the drive control signals s 1 to s 6 . The drive control signals s 1 to s 6 are pulse signals (Pulse Width Modulation (PWM) signals) that repeatedly alternate between H level and L level, and pulsewidths thereof are determined on the basis of received current information.
[0056] The drive control signals s 1 to s 6 sent from the controller 40 are inputted into the driver circuits 31 to 36 , respectively, and switching of the IGBTs 11 to 16 is controlled by the driver circuits 31 to 36 driving the gates thereof.
[0057] In the switching control, for example, in the case where a gate driving level outputted from the driver circuit 31 is H level, a gate voltage is applied to the IGBT 11 , and the IGBT 11 turns on and enters a conductive state as a result. Meanwhile, in the case where the gate driving level outputted from the driver circuit 31 is L level, the IGBT 11 turns off and enters a non-conductive state as a result. The same switching control is carried out for the IGBTs 12 to 16 as well.
[0058] Current detection by the current transformer will be described next. FIG. 3 is a diagram illustrating a current transformer. A current transformer CT is a hollow coil in which an electric line is wrapped around a core material made from a ferromagnetic body.
[0059] When a line L 11 in which current flows is passed through a hole of the current transformer CT, current can be obtained from a line L 12 connected to the current transformer CT at a winding number ratio of 1:n. For example, if a current i 1 flows in the line L 11 , a current i 2 flowing in the line L 12 will be i 2 =i 1 /n. Additionally, if a resistor R is connected to the line L 12 and the resistor R is taken as a load, a voltage V 2 in proportion to the current i 1 (=i 1 ·R/n) can be obtained.
[0060] In this manner, information of the current detected by the current transformer CT is fed back to the controller 40 . On the basis of this current information, the controller 40 outputs the drive control signals s 1 to s 6 for controlling the IGBTs 11 to 16 on and off.
[0061] Issues to be solved will be described next. As illustrated in FIG. 2 , with the IPM 110 , the current transformer CT 1 b is inserted into the main line Lb and the current transformer CT 1 c is inserted into the main line Lc, and a load current (output current) is detected.
[0062] Note that if the load currents flowing in two of the three main lines La, Lb, and Lc are known, the load current flowing in the remaining main line can be found through calculations, and it is for this reason that the current transformers CT 1 b and CT 1 c are inserted into the main lines Lb and Lc in the IPM 110 illustrated in FIG. 2 .
[0063] In this manner, the conventional IPM 110 is configured such that the load currents flowing in the main lines are detected by current transformers, which makes it necessary for the IPM 110 to handle thick main lines or a wide bus bar attached to the main lines. This results in an increase in the sizes of the current transformers and an increase in the space needed to dispose the current transformers, and thus it has been difficult to reduce the size of the device.
[0064] Additionally, the greater the current rating of the IPM 110 , the more the widths of the main lines will increase. This increases the diameter of the holes in the current transformers, which in turn increases the sizes of the current transformers.
[0065] Furthermore, it is desirable that parasitic inductance and parasitic impedance be reduced in order to realize lower noise, lower loss, and so on in the IPM 110 . In this case, the main lines, the bus bar, and so on are made wider and shorter, but making these elements wider also increases the sizes of the current transformers. There is thus a problem in that if an attempt is made to reduce the size it becomes difficult to reduce the parasitic elements.
[0066] Meanwhile, according to the above-described Patent Document 1 (Japanese Patent Application Laid-Open Publication No. 2012-90499), the semiconductor device is divided into a main region and a sense region (a current detection region). Current is detected by obtaining current flowing in the sense region as detection current (sense current) and using a sense resistor to transform the current into a voltage signal.
[0067] However, insulation is a problem when sending a current signal detected using the configuration according to Patent Document 1 (that is, current information transformed into a voltage signal by the sense resistor) to a host controller. For safety reasons, sufficient insulation is required between the host controller and the IPM. Thus components such as an insulation amplifier for transmitting the current information, as well as an A/D converter, a digital isolator, and the like for transmitting the current information as a digital signal, are necessary.
[0068] Here, insulation amplifiers capable of transmitting signals with a high level of precision are expensive, and lead to an increase in costs. Furthermore, the number of components will increase both in the case where an insulation amplifier is used, and in the case where a configuration that transmits using digital values.
[0069] Having been achieved in light of such circumstances, the present invention provides a current detection device and a semiconductor device that solve the above-described conventional issues with current detection, and achieve a reduction in the scales of the devices.
[0070] A configuration and operations in the case where the current detection device 1 according to the present invention is applied in an IPM semiconductor device will be described next. FIG. 4 is a diagram illustrating an example of the configuration of the IPM. Note that in FIG. 4 , a rectifying bridge circuit that takes an AC voltage from an AC source (corresponding to the diodes D 1 to D 6 illustrated in FIG. 2 ) and a smoothing capacitor (corresponding to the capacitor C 1 illustrated in FIG. 2 ).
[0071] An IPM 1 - 1 corresponding to the semiconductor device according to the present invention includes main bridge circuits 10 u , 10 v , and 10 w , current detection bridge circuits 20 u , 20 v , and 20 w , current transformers CT 1 to CT 3 , and driver circuits 31 to 36 . In the same manner as the configuration illustrated in FIG. 2 , the IPM 1 - 1 operates a load M connected to output terminals OUT 1 to OUT 3 on the basis of switching control implemented by a host controller 40 .
[0072] For a U phase, the main bridge circuit 10 u (a U-phase main bridge circuit) and the current detection bridge circuit 20 u (a U-phase current detection bridge circuit) are disposed as a U-phase bridge circuit 1 u.
[0073] The main bridge circuit 10 u includes IGBTs 11 and 12 and diodes D 1 l and D 12 as first U-phase semiconductor devices. The current detection bridge circuit 20 u includes IGBTs 21 and 22 and diodes D 21 and D 22 as second U-phase semiconductor devices.
[0074] For a V phase, the main bridge circuit 10 v (a V-phase main bridge circuit) and the current detection bridge circuit 20 v (a V-phase current detection bridge circuit) are disposed as a V-phase bridge circuit 1 v.
[0075] The main bridge circuit 10 v includes IGBTs 13 and 14 and diodes D 13 and D 14 as first V-phase semiconductor devices. The current detection bridge circuit 20 v includes IGBTs 23 and 24 and diodes D 23 and D 24 as second V-phase semiconductor devices.
[0076] For a W phase, the main bridge circuit 10 w (a W-phase main bridge circuit) and the current detection bridge circuit 20 w (a W-phase current detection bridge circuit) are disposed as a W-phase bridge circuit 1 w.
[0077] The main bridge circuit 10 w includes IGBTs 15 and 16 and diodes D 15 and D 16 as first W-phase semiconductor devices. The current detection bridge circuit 20 w includes IGBTs 25 and 26 and diodes D 25 and D 26 as second W-phase semiconductor devices.
[0078] Note that Si (silicon), SiC (silicon carbide), or the like is used as the material of the IGBTs 11 to 16 and 21 to 26 in FIG. 4 . The diodes D 11 to D 16 and D 21 to D 26 , meanwhile, are constituted of Si-FWDs or Schottky barrier diodes (SiC-SBDs). Additionally, although IGBTs are used as the semiconductor switches in FIG. 4 , Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) may be used instead.
[0079] Here, the main bridge circuit 10 u outputs a main current Im_U (a first U-phase current) through an output line Lm 1 (a first U-phase output line) connected to the load M. The current detection bridge circuit 20 u is connected in parallel to the main bridge circuit 10 u , and outputs a sense current Is_U (a second U-phase current) through an output line Ls 1 (a second U-phase output line) connected at one end to the output line Lm 1 .
[0080] The main bridge circuit 10 v outputs a main current Im_V (a first V-phase current) through an output line Lm 2 (a first V-phase output line) connected to the load M. The current detection bridge circuit 20 v is connected in parallel to the main bridge circuit 10 v , and outputs a sense current Is_V (a second V-phase current) through an output line Ls 2 (a second V-phase output line) connected at one end to the output line Lm 2 .
[0081] The main bridge circuit 10 w outputs a main current Im_W (a first W-phase current) through an output line Lm 3 (a first W-phase output line) connected to the load M. The current detection bridge circuit 20 w is connected in parallel to the main bridge circuit 10 w , and outputs a sense current Is_W (a second W-phase current) through an output line Ls 3 (a second W-phase output line) connected at one end to the output line Lm 3 .
[0082] The current transformer CT 1 (a U-phase current detection unit), which is a first current transformer, is disposed in the output line Ls 1 and detects the sense current Is_U. The current transformer CT 2 (a V-phase current detection unit), which is a second current transformer, is disposed in the output line Ls 2 and detects the sense current Is_V.
[0083] The current transformer CT 3 (a W-phase current detection unit), which is a third current transformer, is disposed in the output line Ls 3 and detects the sense current Is_W. The flow of current is indicated by double-ended arrows in FIG. 4 , and this is to indicate the flow of current from the bridge circuits to the load M and the return of current from the load M to the bridge circuits.
[0084] Connection relationships among the constituent elements will be described next. Collectors of the IGBTs 11 , 13 , 15 , 21 , 23 , and 25 and cathodes of the diodes D 11 , D 13 , D 15 , D 21 , D 23 , and D 25 are connected by a bus L 1 to a P terminal.
[0085] Emitters of the IGBTs 12 , 14 , 16 , 22 , 24 , and 26 and anodes of the diodes D 12 , D 14 , D 16 , D 22 , D 24 , and D 26 are connected by the bus L 2 to an N terminal.
[0086] An emitter of the IGBT 21 , an anode of the diode D 21 , a collector of the IGBT 22 , and a cathode of the diode D 22 are connected by the output line Ls 1 of the current detection bridge circuit 20 u.
[0087] An emitter of the IGBT 11 , an anode of the diode D 11 , a collector of the IGBT 12 , a cathode of the diode D 12 , and the output terminal OUT 1 are connected by the output line Lm 1 of the main bridge circuit 10 u . The current transformer CT 1 is inserted into the output line Ls 1 , and the output line Ls 1 and output line Lm 1 are connected by a node n 1 .
[0088] Meanwhile, an emitter of the IGBT 23 , an anode of the diode D 23 , a collector of the IGBT 24 , and a cathode of the diode D 24 are connected by the output line Ls 2 of the current detection bridge circuit 20 v.
[0089] An emitter of the IGBT 13 , an anode of the diode D 13 , a collector of the IGBT 14 , a cathode of the diode D 14 , and the output terminal OUT 2 are connected by the output line Lm 2 of the main bridge circuit 10 v . The current transformer CT 2 is inserted into the output line Ls 2 , and the output line Ls 2 and output line Lm 2 are connected by a node n 2 .
[0090] Furthermore, an emitter of the IGBT 25 , an anode of the diode D 25 , a collector of the IGBT 26 , and a cathode of the diode D 26 are connected by the output line Ls 3 of the current detection bridge circuit 20 w.
[0091] An emitter of the IGBT 15 , an anode of the diode D 15 , a collector of the IGBT 16 , a cathode of the diode D 16 , and the output terminal OUT 3 are connected by the output line Lm 3 of the main bridge circuit 10 w . The current transformer CT 3 is inserted into the output line Ls 3 , and the output line Ls 3 and output line Lm 3 are connected by a node n 3 .
[0092] The current detection lines of the current transformers CT 1 to CT 3 are connected to the controller 40 . An output terminal of the driver circuit 31 is connected to bases of the IGBTs 11 and 21 , and an output terminal of the driver circuit 32 is connected to bases of the IGBTs 12 and 22 .
[0093] An output terminal of the driver circuit 33 is connected to bases of the IGBTs 13 and 23 , and an output terminal of the driver circuit 34 is connected to bases of the IGBTs 14 and 24 . An output terminal of the driver circuit 35 is connected to bases of the IGBTs 15 and 25 , and an output terminal of the driver circuit 36 is connected to bases of the IGBTs 16 and 26 .
[0094] Here, on the basis of the information of currents detected by the current transformers CT 1 to CT 3 , the controller 40 generates driving control signals (not illustrated) for controlling switching of the transistors and sends the generated signals to the driver circuits 31 to 36 , respectively.
[0095] The driving of the IGBT 11 within the main bridge circuit 10 u (a first U-phase high-side transistor) and the driving of the IGBT 21 of the current detection bridge circuit 20 u (a second U-phase high-side transistor) are controlled by the same driver circuit 31 (a U-phase high-side driver circuit).
[0096] The driving of the IGBT 12 within the main bridge circuit 10 u (a first U-phase low-side transistor) and the driving of the IGBT 22 of the current detection bridge circuit 20 u (a second U-phase low-side transistor) are controlled by the same driver circuit 32 (a U-phase low-side driver circuit).
[0097] Meanwhile, the driving of the IGBT 13 within the main bridge circuit 10 v (a first V-phase high-side transistor) and the driving of the IGBT 23 of the current detection bridge circuit 20 v (a second V-phase high-side transistor) are controlled by the same driver circuit 33 (a V-phase high-side driver circuit).
[0098] Additionally, the driving of the IGBT 14 within the main bridge circuit 10 v (a first V-phase low-side transistor) and the driving of the IGBT 24 of the current detection bridge circuit 20 v (a second V-phase low-side transistor) are controlled by the same driver circuit 34 (a V-phase low-side driver circuit).
[0099] Furthermore, the driving of the IGBT 15 within the main bridge circuit 10 w (a first W-phase high-side transistor) and the driving of the IGBT 25 of the current detection bridge circuit 20 w (a second W-phase high-side transistor) are controlled by the same driver circuit 35 (a W-phase high-side driver circuit).
[0100] Additionally, the driving of the IGBT 16 within the main bridge circuit 10 w (a first W-phase low-side transistor) and the driving of the IGBT 26 of the current detection bridge circuit 20 w (a second W-phase low-side transistor) are controlled by the same driver circuit 36 (a W-phase low-side driver circuit).
[0101] As described above, the IPM 1 - 1 has a configuration in which in each phase, a current detection bridge circuit constituted of current detection IGBTs and diodes (FWDs) and a main bridge circuit constituted of main IGBTs and diode (FWDs) are connected in parallel.
[0102] In other words, in the U phase, the current detection bridge circuit 20 u including the IGBTs 21 and 22 and the diodes D 21 and D 22 , and the main bridge circuit 10 u including the main IGBTs 11 and 12 and the diodes D 11 and D 12 , are connected in parallel.
[0103] In the V phase, the current detection bridge circuit 20 v including the IGBTs 23 and 24 and the diodes D 23 and D 24 , and the main bridge circuit 10 v including the main IGBTs 13 and 14 and the diodes D 13 and D 14 , are connected in parallel.
[0104] In the W phase, the current detection bridge circuit 20 w including the IGBTs 25 and 26 and the diodes D 25 and D 26 , and the main bridge circuit 10 w including the main IGBTs 15 and 16 and the diodes D 15 and D 16 , are connected in parallel.
[0105] Additionally, the current transformer CT 1 is inserted into the output line Ls 1 of the current detection bridge circuit 20 u , and the current transformer CT 1 detects the sense current Is_U flowing in the current detection bridge circuit 20 u.
[0106] Likewise, the current transformer CT 2 is inserted into the output line Ls 2 of the current detection bridge circuit 20 v , and the current transformer CT 2 detects the sense current Is_V flowing in the current detection bridge circuit 20 v.
[0107] Furthermore, the current transformer CT 3 is inserted into the output line Ls 3 of the current detection bridge circuit 20 w , and the current transformer CT 3 detects the sense current Is_W flowing in the current detection bridge circuit 20 w.
[0108] On the other hand, the output lines of the current detection bridge circuits in each phase are connected to the output lines of the main bridge circuits into which the current transformers have been inserted. In other words, the output line Ls 1 of the U-phase current detection bridge circuit 20 u is connected to the output line Lm 1 of the main bridge circuit 10 u at the node n 1 located beyond where the current transformer CT 1 is inserted.
[0109] Additionally, the output line Ls 2 of the V-phase current detection bridge circuit 20 v is connected to the output line Lm 2 of the main bridge circuit 10 v at the node n 2 located beyond where the current transformer CT 2 is inserted.
[0110] Furthermore, the output line Ls 3 of the W-phase current detection bridge circuit 20 w is connected to the output line Lm 3 of the main bridge circuit 10 w at the node n 3 located beyond where the current transformer CT 3 is inserted.
[0111] As such, in the U phase, the sense current Is_U flowing in the current detection bridge circuit 20 u is added to the main current Im_U flowing in the main bridge circuit 10 u , and thus a load current I_U outputted from the output terminal OUT 1 is I_U=Im_U+Is_U.
[0112] Likewise, in the V phase, the sense current Is_V flowing in the current detection bridge circuit 20 v is added to the main current Im_V flowing in the main bridge circuit 10 v , and thus a load current I_V outputted from the output terminal OUT 2 is I_V=Im_V+Is_V.
[0113] Furthermore, in the W phase, the sense current Is_W flowing in the current detection bridge circuit 20 w is added to the main current Im_W flowing in the main bridge circuit 10 w , and thus a load current I_W outputted from the output terminal OUT 3 is I_W=Im_W+Is_W.
[0114] Next, a ratio between the main current Im and the sense current Is will be described. As described above, the IPM 1 - 1 is configured such that the load current outputted from a single output terminal is divided into a main current and a sense current flowing in two current paths, namely the output line of the main bridge circuit and the output line of the current detection bridge circuit, and the sense current is detected by the current transformer.
[0115] In this case, a current ratio between the sense current flowing in the output line of the current detection bridge circuit and the main current flowing in the output line of the main bridge circuit is the same as a surface area ratio between a chip surface area of the semiconductor devices in the current detection bridge circuit and a chip surface area of the semiconductor devices in the main bridge circuit. Note that the surface area referred to here is, for example, an active surface area of the semiconductor devices (a surface area of active layers).
[0116] FIGS. 5 to 7 are diagrams illustrating correspondence relationships between the surface area ratio and the current ratio. In the U phase illustrated in FIG. 5 , a surface area ratio between a surface area of the IGBTs 21 and 22 and the diodes D 21 and D 22 of the current detection bridge circuit 20 u (a second U-phase active surface area) and a surface area of the IGBTs 11 and 12 and the diodes D 11 and D 12 of the main bridge circuit 10 u (a first U-phase active surface area) is 1:4, for example.
[0117] Because the surface area ratio and the current ratio are equal, the current ratio between the sense current Is_U outputted from the current detection bridge circuit 20 u and flowing in the output line Ls 1 , and the main current Im_U outputted from the main bridge circuit 10 u and flowing in the output line Lm 1 , is also 1:4.
[0118] Accordingly, the sense current Is_U in the U phase is ⅕ the total load current I_U in the U phase. In other words, Is_U=I_U/(1+4). Therefore, because the surface area ratio is determined at the design stage and is known, the U-phase load current I_U can be found by multiplying the current value detected by the current transformer CT 1 inserted into the output line Ls 1 of the current detection bridge circuit 20 u by 5.
[0119] Likewise, in the V phase illustrated in FIG. 6 , a surface area ratio between a surface area of the IGBTs 23 and 24 and the diodes D 23 and D 24 of the current detection bridge circuit 20 v (a second V-phase active surface area) and a surface area of the IGBTs 13 and 14 and the diodes D 13 and D 14 of the main bridge circuit 10 v (a first V-phase active surface area) is 1:4, for example.
[0120] Because the surface area ratio and the current ratio are equal, the current ratio between the sense current Is_V outputted from the current detection bridge circuit 20 v and flowing in the output line Ls 2 , and the main current Im_V outputted from the main bridge circuit 10 v and flowing in the output line Lm 2 , is also 1:4.
[0121] Accordingly, the sense current Is_V in the V phase is ⅕ the total load current I_V in the V phase. In other words, Is_V=I_V/(1+4). Therefore, because the surface area ratio is determined at the design stage and is known, the V-phase load current I_V can be found by multiplying the current value detected by the current transformer CT 2 inserted into the output line Ls 2 of the current detection bridge circuit 20 v by 5.
[0122] Likewise, in the W phase illustrated in FIG. 7 , a surface area ratio between a surface area of the IGBTs 25 and 26 and the diodes D 25 and D 26 of the current detection bridge circuit 20 w (a second W-phase active surface area) and a surface area of the IGBTs 15 and 16 and the diodes D 15 and D 16 of the main bridge circuit 10 w (a first W-phase active surface area) is 1:4, for example.
[0123] Because the surface area ratio and the current ratio are equal, the current ratio between the sense current Is_W outputted from the current detection bridge circuit 20 w and flowing in the output line Ls 3 , and the main current Im_W outputted from the main bridge circuit 10 w and flowing in the output line Lm 3 , is also 1:4.
[0124] Accordingly, the sense current Is_W in the W phase is ⅕ the total load current I_W in the W phase. In other words, Is_W=I_W/(1+4). Therefore, because the surface area ratio is determined at the design stage and is known, the W-phase load current I_W can be found by multiplying the current value detected by the current transformer CT 3 inserted into the output line Ls 3 of the current detection bridge circuit 20 w by 5.
[0125] To generalize the details described above, the surface area ratio between the surface area of the semiconductor devices in the current detection bridge circuit and the surface area of the semiconductor devices in the main bridge circuit is s:m. In this case, the current ratio between the sense current outputted from the current detection bridge circuit and the main current outputted from the main bridge circuit is s:m as well. Accordingly, a relational expression between the sense current Is and a total load current I is Is=I·s/(s+m).
[0126] In this manner, the sense current flowing in the current detection bridge circuit and the main current flowing in the main bridge circuit are determined by the chip surface area ratio between the IGBTs and FWDs within the current detection bridge circuit and the IGBTs and FWDs within the main bridge circuit. Thus the total load current can be found by detecting the sense current using the current transformers and factoring in the surface area ratio of the semiconductor devices.
[0127] Additionally, in this case, the chip surface area of the IGBTs and FWDs within the current detection bridge circuit is smaller than the chip surface area of the IGBTs and FWDs within the main bridge circuit. As a result, the sense current flowing in the current detection bridge circuit becomes lower than the main current flowing in the main bridge circuit (sense current Is<main current Im). This makes it possible to employ small current transformers, which in turn makes it possible to reduce the scale of the device.
[0128] For example, in the case where the IPM has a current rating of 300 A, an IPM in which a current transformer is inserted into the main line as illustrated in FIG. 2 will require no less than 300 A as an input current range of the current transformer used therein, resulting in an increase in size.
[0129] As opposed to this, with the IPM 1 - 1 illustrated in FIG. 4 , the sense current flowing in the current detection bridge circuit connected in parallel to the main bridge circuit is detected. As such, in this example, a current transformer having an input current range of no less than ⅕ the current rating, namely 60 A, can be used. This makes it possible to use a small-size current transformer.
[0130] Conventionally, the current information obtained by detecting the load current flowing in the main line is received by the controller, whereupon the controller generates the driving control signals to carry out switching control. As opposed to this, according to the present invention, the current information of the current flowing in the current detection bridge circuit is received by the controller, but as described above, the total load current can easily be calculated from the received current information. Thus no impediments to the switching control will arise.
[0131] Additionally, according to the IPM 1 - 1 illustrated in FIG. 4 , current detection is carried out for all three phases, namely U, V, and W, using the three current transformers CT 1 to CT 3 . The information of the detected currents is obtained for each of the phases using the information of the detected currents so that, for example, the controller can carry out protection control for overvoltage and the like in each phase.
[0132] Thus in the case where the state of each phase is obtained from the current information, the current is detected for all of the three phases, namely U, V, and W (if the function is only for finding the load current, the configuration may be such that the current is detected for only two of the three phases).
[0133] Variations on the current detection bridge circuit will be described next. FIG. 8 is a diagram illustrating the configuration of a variation on the current detection bridge circuit. A current detection bridge circuit 20 u - 1 according to this variation has resistors Rgs 1 and Rgm 1 and resistors Rgs 2 and Rgm 2 as new elements.
[0134] One end of the resistor Rgs 1 is connected to a gate of the IGBT 21 , and another end of the resistor Rgs 1 is connected to an output end of the driver circuit 31 and one end of the resistor Rgm 1 . Another end of the resistor Rgm 1 is connected to a gate of the IGBT 11 .
[0135] One end of the resistor Rgs 2 is connected to a gate of the IGBT 22 , and another end of the resistor Rgs 2 is connected to an output end of the driver circuit 32 and one end of the resistor Rgm 2 . Another end of the resistor Rgm 2 is connected to a gate of the IGBT 12 .
[0136] The stated resistors Rgs 1 and Rgm 1 and resistors Rgs 2 and Rgm 2 are gate resistors for timing adjustment. Providing such resistors makes it possible to eliminate gate timing differences. In other words, providing the resistors Rgs 1 and Rgm 1 reduces a gate driving timing difference for the IGBT 11 and the IGBT 21 . Likewise, providing the resistors Rgs 2 and Rgm 2 reduces a gate driving timing difference for the IGBT 12 and the IGBT 22 .
[0137] Furthermore, providing the resistors Rgs 1 and Rgm 1 and the resistors Rgs 2 and Rgm 2 makes it possible to avoid a situation where current concentrates in the diodes. Although FIG. 8 only illustrates the configuration of the variation on the U-phase current detection bridge circuit, the configuration is the same for the V- and W-phase current detection bridge circuits as well.
[0138] Effects of the present invention will be described next, including points of difference from the conventional technique. Rather than detection a main current flowing in a main line using a current transformer as with the conventional IPM 110 illustrated in FIG. 2 , the IPM 1 - 1 according to the technique of the present invention illustrated in FIG. 4 is configured such that the bridge circuits are divided into main bridge circuits and current detection bridge circuits, and currents flowing in the current detection bridge circuits are detected by current transformers.
[0139] The sense current flowing in the current detection bridge circuit is determined by a surface area ratio between the active surface area of the semiconductor devices constituting the current detection bridge circuit and the active surface area of the semiconductor devices constituting the main bridge circuit.
[0140] Accordingly, if the design is such that the active surface area ratio is a ratio of approximately 1:several thousand, for example, the sense current can be brought to a small current on the order of 1/several thousand, compared to the main current. Accordingly, the sense current detected by the current transformer is much smaller than the main current, which makes it possible to use small current transformers. This in turn makes it possible to reduce the scale and costs of the device.
[0141] Additionally, reducing the size of the current transformers makes integration into the IPM possible. In this case, no current transformer is inserted into the main line located between the output terminal of the IPM and the load, and thus a compact product form can be achieved. Furthermore, as an advantage for IPM developers, the current detection circuit can be integrated into a module, which makes designing a current detection circuit unnecessary. This can contribute to a reduction in the product design lead time.
[0142] Furthermore, integrating the current transformers into the IPM makes it possible to make the main line, the bus bar, and so on short and thick, which in turn makes it easy to reduce parasitic elements.
[0143] On the other hand, according to the above-described Patent Document 1, the semiconductor device is divided into a main region and a sense region (a current detection region), and current is detected by transforming current flowing in the sense region into a voltage signal using a sense resistor.
[0144] As opposed to this, according to the present invention, bridge circuits in which the main bridge circuits and the current detection bridge circuits are connected in parallel are provided, and the configuration is such that currents flowing in the current detection bridge circuits are detected using current transformers rather than sense resistors.
[0145] Additionally, the current transformer is a hollow coil in which an electric line is wrapped around a core material made from a ferromagnetic body, as illustrated in FIG. 3 , and is a device in which the current transformer itself is insulated.
[0146] Although Patent Document 1 requires a new component for insulation, the present invention uses current transformers and thus does not require insulating devices for signal transmission. Accordingly, increases in the number of components and costs can be suppressed.
[0147] Furthermore, according to Patent Document 1, an emitter terminal is split between use for a main region and a sense region to obtain current, and thus a current detection circuit is provided for each semiconductor device. As opposed to this, the configuration of the present invention is such that the bridge circuit itself is divided into a main bridge circuit and a current detection bridge circuit, and a current transformer is inserted into the output line of that current detection bridge circuit.
[0148] Thus comparing the three-phase full bridge circuit, while Patent Document 1 requires a maximum of six current detection circuits, the present invention only requires three current detection units (three current transformers), which makes it possible to achieve further miniaturization.
[0149] While embodiments have been described thus far as examples, the configurations of the elements described in the embodiments can be replaced with other elements having equivalent functions. Other desired configurations, processes, and so on may be added as well.
[0150] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents. In particular, it is explicitly contemplated that any part or whole of any two or more of the embodiments and their modifications described above can be combined and regarded within the scope of the present invention. | An inverter circuit with a current detection circuitry includes a main bridge circuit connected between the pair of DC input nodes, the main bridge circuit converting the received DC voltage to a primary AC current so as to output the primary AC current through an output terminal to be connected to a load; a supplementary bridge circuit connected in parallel to the main bridge circuit between the pair of DC input nodes, the supplementary bridge circuit having a circuit configuration identical to that of the main bridge circuit with smaller circuit parameters in at least some of constituent circuit elements so as to generate a detection-use AC current that is a prescribed fraction of said AC current outputted by the main bridge circuit. The detection-use AC current is detected by a current detector so as to calculate the amount of the primary AC current. | 7 |
BACKGROUND
This invention relates to methods and systems for operating revolving credit programs and, more specifically, to revolving credit programs in which the interest rate applied to an outstanding balance is varied.
Revolving credit programs typically are offered by banks, savings and loans, federal savings banks, credit unions and other credit providers, and operate to advance funds as cash advances or to pay for purchases made by a customer, such as through a credit card or a personal line of credit, and in some instances to pay for checks written by the customer, or to cover funds provided through other access devices, such as automatic teller machines, telephone communication devices and personal computers. Under such revolving credit programs, the customer enters into an agreement with a credit provider in which the unpaid balance of the customer's loan is assessed a finance charge which represents either a fixed interest rate or a variable interest rate which is tied to the prime rate or some other interest rate index.
Once debt is incurred, the customer generally has three options for repayment of the debt. One option is for the customer to pay the entire outstanding balance and avoid assessment of any interest or finance charges, in the case of purchase transactions. A second option is for the customer to pay a minimum amount required by the credit provider to reduce the amount of the outstanding balance and defer the remaining outstanding balance for later payment. In that case, the customer is assessed interest or finance charges based on the remaining outstanding balance.
Under the third option, the customer pays more than the minimum required by the credit provider but less than the entire outstanding balance. If this alternative is chosen, the customer is assessed interest or finance charges in the same way as the second option.
There presently exist programs in which a tiered interest rate is applied to an outstanding balance. Specifically, different interest rates are applied to various levels of an outstanding balance. Further, systems exist in which different interest rates are applied to varying levels of purchases, or to types of purchases. All such programs are designed to encourage the credit customer to increase purchase volume and/or increase outstanding balance.
Levels of personal debt are reaching record-breaking highs and as a result, credit card delinquency rates are increasing. The ratio of total household debt to disposable income has reached a record high. Accordingly, there is a need for a revolving credit system which provides an incentive to encourage a credit customer to pay off his or her outstanding balance quickly. Furthermore, such a system should be entirely automated and operable on the platform of a personal computer or computer network.
SUMMARY
The present invention is a fully automated system and method for providing a revolving credit program through a credit provider which helps revolving credit customers gain control over their finances and encourages responsible financial management. In a preferred embodiment of the invention, a revolving credit system and method are provided in which the interest rate finance charge applied to the outstanding balance of a customer's account varies according to the percentage of the outstanding balance paid by a customer in a billing cycle. The greater the percentage of the outstanding balance paid off by the customer in a billing cycle, the lower the interest rate applied to the remaining unpaid outstanding balance during the next billing cycle. In the alternative, the interest rate finance charge can be varied according to the percentage of other parameters of the account, such as beginning balance, highest balance or average balance in the billing cycle.
Also in the preferred embodiment, the system and method provides a tiered interest rate structure. For example, if the credit customer pays 2% of the outstanding balance in a billing cycle, the interest applied to the remaining outstanding balance is 16.5%; if the credit customer pays 3% of the outstanding balance, the applied interest rate is reduced to 12.9%; and if the credit customer pays 5% or more of the outstanding balance, the applied interest rate is further reduced to 8.9%. Of course, other interest rates and payment percentages can be applied, as well as different numbers of interest rate “tiers,” without departing from the scope of the present invention.
Consequently, the system and method of the present invention is sufficiently flexible to accommodate month-to-month variations in a credit customer's financial situation by offering a number of different payment options. The tiered applied interest rate structure of the invention allows the credit customer to choose his or her minimum payment and interest rate.
The system and method of the preferred embodiment of the present invention also provides a display, which may be on a monitor or in printed form, of the previous outstanding balance, the payments received, the finance charge applied, the new outstanding balance and the minimum payment amounts necessary to qualify the credit customer for each interest rate level.
The system is designed to be operable on a personal computer, or network of personal computers, and includes software having a set of instructions for operating the personal computer. The software is stored on a disk, tape, hard drive or other storage media, and is loaded into the memory of the computer from storage during use. All information pertaining to the account is kept in storage in the computer, as is the table of percentages and corresponding interest rates. Each transaction, whether it is a payment or a debit to the account, is also entered and stored for each account.
The system is adaptable to be used with credit card programs, home equity loan programs, and unsecured lines of credit, to consumers for personal, family and household purposes, as well as to business entities for business, agricultural, and governmental uses.
Accordingly, it is an object of the present invention to provide a system and method for operating a revolving credit program; a system and method for operating a revolving credit program which encourages a credit customer to pay off an outstanding account balance quickly; a system and method for operating a revolving credit program having a tiered interest rate structure such that a lower interest rate is applied to a remaining outstanding balance in response to higher balance percentage pay off in a billing period; and a system and method for operating a revolving credit program which runs from a personal computer and/or network platform.
Other objects and advantages of the present invention will be apparent from the following description, accompanying drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE is a flow chart showing the operation of the method of the present invention on a personal computer or computer network.
DETAILED DESCRIPTION
The FIGURE shows a flow chart which represents the operation of a personal computer or computer network programmed to embody the system of the present invention and to perform the method of the present invention. The instructions for performing the process of the system preferably are in the form of computer software which is kept in a storage medium, such as a disk, tape, hard drive or the like. The software is loaded into computer memory from storage when the program is to be implemented.
The Functional block 10 represents the “wait state” of the system. The method of the invention is triggered by the occurrence of either the end of a billing period or a transaction being entered into a credit customer's account. In the preferred embodiment, a timing program (not shown) internal to the computer platform operated according to the method of the invention will signal the system of the end of a billing period, which may correspond with the end of a calendar month. Accordingly, functional block 12 indicates that the system is activated at the end of a billing period, or, as shown in block 14 , if a transaction is entered. If no transaction occurs, and the end of a billing cycle has not occurred, the system remains in the wait state of block 10 .
If there is a transaction, as shown in block 14 , the operator or system enters the credit customer's account number, the nature of the transaction (i.e., payment, debit or the like) and the date of the transaction, as shown in block 16 . This information is stored in the computer system, as shown in block 18 .
The central processing unit of the computer system then reads into memory from storage the current outstanding balance of the credit customer's account, as shown in block 20 . Once the current outstanding balance is read into memory, the outstanding balance is adjusted by the transaction amount in order to arrive at a new, interim outstanding balance (“I.O.B.”), as shown in block 22 . This new interim outstanding balance is then stored in the system, as shown in block 24 . The system then returns to the wait state of block 10 . This iteration through blocks 10 - 24 may occur several times in the course of a billing cycle, each time a transaction is entered. A billing cycle typically is a one month or thirty day calendar period, but may be any time period contracted upon by the credit provider and the credit consumer.
At the end of the billing period, shown at block 12 , the system is programmed to calculate an average daily balance, shown in block 26 . The average daily balance method is a conventional calculation in which the interim outstanding balance at each day of the current billing period is determined, then averaging the daily balances over the billing period. In the alternative, the system may be programmed to calculate finance charges based on ending balance, two cycle average daily balance, and the like, without departing from the scope of the present invention. This average daily balance, or amount calculated using an alternative method as explained above, is then stored in the system, as shown in block 28 . In addition, the total payments made during the current billing period are summed and stored, as shown in block 30 .
The central processing unit next calculates the percentage the total payments made during the current billing period comprise of the previous month's outstanding balance, or the percentage of balance reduction, as shown in block 32 . The unit then reads a stored table of percentages and corresponding tiered interest rates, as shown in block 34 , and compares the calculated percentage of balance reduction of block 32 to match it with one of the stored percentages of the table. Each stored percentage on the table has a corresponding interest rate. In the alternative, the system can utilize other customer account parameters, such as comparing the balance reduction to the beginning balance or to the highest balance in the billing cycle to determine a percentage, without departing from the scope of the invention.
The interest rate corresponding to the percentage which matches the percentage of balance reduction calculated in block 32 is then selected as the applied interest rate, all as shown in block 34 . The applied interest rate selected in block 34 is then applied to the average daily balance calculated in block 26 and stored in block 28 , to arrive at a finance charge, as shown in block 36 .
The finance charge is then added into the interim outstanding balance, calculated in block 24 , to arrive at a new balance. This new balance value is then stored, as shown in block 38 . The new balance then becomes the “outstanding balance” which is read and adjusted pursuant to the process shown in blocks 14 - 24 in the next billing cycle.
Using the new balance calculated in block 38 , the system then calculates the minimum payments necessary to meet the threshold percentages necessary to qualify for the varying tiered interest rates of block 34 , as shown in block 40 . Finally, a statement (or terminal display) is generated by the system which shows values for the new balance calculated in block 38 , the finance charge calculated in block 36 , and the proposed minimum payments calculated in block 40 to qualify for each tiered level of interest, as shown in block 42 . The statement may contain any or all of this information in addition to other account information and disclosures as required by federal law and subject to change from time to time.
If the display is in the form of a statement, the statement is then sent to the credit customer. Therefore, the credit customer not only receives a current status report of his or her account, showing the current new balance, the finance charge applied and the payments received in the just-completed billing cycle, but the credit customer also receives a schedule of minimum payments necessary to qualify for each tier of reduced interest rates effective for the customer's next billing cycle.
Specific Example
In a specific example, the table of percentages which is read in block 34 may be as follows:
TABLE 1
Percent of Outstanding Balance Paid
Applied Ann. Int. Rate
5% and over
8.9%
3% to 4.99%
12.9%
2% to 2.99%
16.5%
If a credit customer has an outstanding balance at the end of a billing period of, for example, $2,000.00 (comprising, for example, principal of $1985.00 and a finance charge of $15.00), and during the course of the subsequent billing period makes a payment on day 14 of that subsequent billing period of $100.00, the balance at the end of that subsequent billing period (before the finance charge is applied) will be $1,900.00, a balance reduction of 5%. Then, according to the Table I set forth above, the credit customer qualifies for an applied annual interest rate of 8.9%, which is a monthly periodic rate of 0.7416%.
This 0.7416% is applied to the average daily balance to arrive at the finance charge. In this example, the average daily balance would be $1936.83, which is arrived at by adding up the outstanding unpaid principal balance for each day of the billing period and dividing the total by the number of days in the billing period (for example, 30 days): ( $1985 .00 × 13 days ) + ( $1900 .00 × 17 days ) 30 days = $1936 .83
The finance charge would then be $14.36 ($1,936.83×0.7416%), making a new balance of $1,914.36. The calculations would be similar for any ending balance representing an outstanding balance reduction of 5% or more, up to but not including full payment of the outstanding balance. Specifically, the same monthly periodic rate would be applied from the table, but the average daily balance, and therefore the finance charge, would be less.
If the credit customer pays only $60.00, which would result in a balance reduction of 3%, according to Table 1, an annual interest rate of 12.9% (which is a monthly periodic rate of 1.075%) is applied to the average daily balance, which would be $1,959.76 (assuming payment of the $60.00 is made on day 14 of the billing cycle), resulting in a finance charge of $21.06, which is added to the interim outstanding balance of $1,940.00, for a new balance of $1961.06. The system would perform similar calculations for any ending balance representing an outstanding balance reduction of at least 3% and up to 5%.
Similarly, if the credit customer pays only 2% of the $2,000.00 outstanding balance, a payment of $40.00, the average daily balance would be $1,970.83 (again assuming the payment of $40.00 is made on day 14 of the billing cycle), and the applied annual interest rate for a 2% balance reduction taken from Table I is 16.5%, a monthly periodic rate of 1.375%. The finance charge is then $27.09. Accordingly, the new balance would be $1,987.09. However, if the credit customer pays less than 2% of the outstanding balance, the same annual interest rate is applied, but that credit customer would be considered delinquent.
Of course, the look-up table represented by Table I above and utilized in block 34 of the Figure can be varied to provide for different numbers of “tiers,” or for different interest rates for each percentage tier, or for different percentages of balance reduction without departing from the scope of the present invention.
Applying the values set forth to the display block 42 of FIG. 1, for a 5% balance reduction (i.e., a payment of $100.00 toward an outstanding balance of $2,000.00 in the specific example), the display would include a listing of the new balance of $1,914.36. Furthermore, the display of block 42 would also include a listing of the minimum payments necessary to meet the 5%-3%-2% outstanding balance reduction to qualify for each of the tiered interest rates of 8.9%, 1-2.9% and 16.5%, respectively, namely, payments of $96.00, $58.00, and $39.00, respectively, for the outstanding balance of $1914.36 discussed above. These minimum payment amounts may be rounded up or down to the nearest dollar amount without departing from the scope of the present invention.
In conclusion, the credit customer is encouraged to make larger payments which represent larger percentages of the outstanding balance in order to qualify for the corresponding lower applied interest rate. The end result desired by the credit provider who utilizes this system would be fewer delinquent accounts.
The tiered interest rate system of the present invention can be utilized with any revolving credit program, including credit card programs, home equity lines of credit, and secured and unsecured lines of credit. Such programs can be used by individuals for home, consumer product and automobile purchases, and by businesses and governmental entities for commercial and agricultural purchases.
While the form of apparatus and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to these precise forms of apparatus and methods, and that changes may be made therein without departing from the scope of the invention. | A method and a system for operating a revolving credit program utilizing a table of tiered interest rates in which one of the interest rates is applied as a finance charge to a remaining outstanding balance ( 20 ) of an account depending upon the percentage that payments made during a billing cycle ( 12 ) comprise of an account parameter, such as the outstanding balance, a highest balance or a beginning balance. In the preferred embodiment the applied interest rate ( 34 ) is determined by the percentage the outstanding balance ( 32 ) is reduced by payments on the balance during a billing cycle. Also in a preferred embodiment of the invention, the tiered interest rate table is structured to apply progressively reduced interest rates to outstanding balances reduced by progressively greater payment percentages from the previous billing cycle, thereby encouraging a credit customer to make larger payments and pay down the outstanding balance faster. Also in the preferred embodiment, the system calculates and displays ( 42 ) the minimum payments necessary to reduce the outstanding balance to meet each tier of the interest rate table. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
CITED REFERENCES
The following references are cited within this invention description:
[1] Telatar, I. E., ‘Capacity of multi-antenna Gaussian channels’, Technical Memorandum, Bell Laboratories, Lucent Technologies, October 1995 [2] Conway, J. H., Sloane, N. J. A., ‘Sphere Packings, Lattices and Groups’, Springer-Verlag, 3rd Edition, 1998 [3] Nissani (Nissensohn), D. N., ‘Memory Capacity Enhancement Method and Apparatus’, March 2008, U.S. application Ser. No. 12/074,287 [4] Nissani (Nissensohn), D. N., ‘Memory Capacity Enhancement Method and Apparatus’, June 2009, U.S. application Ser. No. 12/455,287 [5] Nissani (Nissensohn), D. N., ‘Communication and Memory Capacity Enhancement Method and Apparatus’, August 2010, U.S. Pat. No. 8,307,184 [6] Sommer, N., Feder M., Shalvi, O., ‘Low Density Lattice Codes’, IEEE International Symposium on Information Theory, Seattle, July 2006 [7] Lang, G. R., Longstaff, F. M., ‘A Leech Lattice Modem’, IEEE JSAC, August 1989 [8] Forney, G. D., Gallager, R. G., Lang, G. R., Longstaff, F. M., Qureshi, S. U., ‘Efficient Modulation for Band-Limited Channels’, IEEE JSAC, September 1984 [9] Gallager, R. G., ‘Low Density Parity Check Codes’, Ph D Dissertation, MIT, 1963 [10] Yona, Y., Feder, M., ‘Efficient Parametric Decoder of Low Density Lattice Codes’, ISIT 2009, July 2009 [11] Viterbo, E., Boutros, J., ‘A universal lattice code decoder for fading channels’, IEEE Transactions on IT, July 1999 [12] Nissani (Nissensohn), D. N., ‘Multi-input-multi-output wireless communication Method and Apparatus’, July 2006, U.S. Pat. No. 7,583,763 [13] Forney, G. D., ‘Coset Codes—Part I: Introduction and Geometrical Classification’, IEEE Transactions on IT, September 1988 [14] Conway, J. H., Sloane, N. J. A., ‘Fast Encoding Method for Lattice Codes and Quantizers’, IEEE Transactions on IT, November 1983 [15] Duda, R. O., Hart, P. E., ‘Pattern Classification and Scene Analysis’, John Wiley & Sons, 1973
BACKGROUND OF THE INVENTION
Since its inception in 1995 (see Telatar [1]) Multi-Input-Multi-Output (MIMO) technology has become a keystone of wireless standards. Based upon simultaneous transmission and reception through multiple antennas, it enables information capacity increase, proportionate to the number of either transmitting or receiving antennas (specifically, to the smallest of these two). This increase, relative to transmission and reception through a single antenna at each side, is achieved with neither power nor spectrum penalty. The only cost then is merely the cost of the extra implementation hardware. MIMO has been adopted by both Wireless LAN and Cellular standards, with MIMO dimension increasing and antenna arrays as big as 8×8 being defined in next generation standards.
Error Correction Coding (ECC) methods by which the distance (as defined in some suitable abstract space) between transmitted information messages is increased, relative to the distance between uncoded messages, so that their resilience to transmission channel distortion and noise is enhanced have been known and widely utilized for more than 60 years. These codes have been traditionally designed over binary spaces. The metric defined in these spaces is usually the so called Hamming distance.
Binary ECC is implemented by mapping an information binary vector into a longer binary vector. Better error performance (i.e. lower Bit Error Rate (BER) or, equivalently, coding gain) is achieved then at the expense of extra bits. When the transmission channel is limited to a maximal signaling rate (channel uses per unit of time) longer transmission vectors are equivalent to lower information rate; so binary ECC achieves better BER than uncoded information bits at the usual penalty of lower information rate.
ECC may be also implemented in other spaces. In particular coded modulation schemes in which distinct messages are mapped in the modulated signal space, so that their Euclidean distances from each other (or other related metrics) are optimized in some way have been known for a long time (see e.g. Forney [13]). Said schemes are also known as signal coding, or signal space coding methods. An important example of this class of methods (but certainly not exclusive) is Lattice Coding (see Conway and Sloane [2]). In Lattice Coding, messages represented by, say, binary vectors are efficiently mapped into signal space, resembling efficiently packed solid spheres in a given volume; Lattice Coding falls then under the theory of Sphere Packing.
It should be noted that while we use the term Lattice Code in the sequel, the proposed invention is equally applicable to other signal space coding schemes, and adaptations of the present invention to fit such schemes should be easily made by those skilled in the art.
Since the transmitted coded message is transmitted at the same channel signaling rate as an uncoded message, then no information rate penalty is incurred in their use, and their BER coding gain comes practically for free (except of course for the cost of the implementation machinery).
As mentioned above, Lattice Codes are usually generated by mapping a (usually) binary information vector message into a suitable integer vector (i.e. a vector in which its elements are integer numbers) such that the eventually resulting lattice point is confined to a specified transmission efficient closed region of space, typically a hyper-cube or hyper-sphere; this process may be called the Lattice Encoding process (see Nissani [3], [4], [5] and Conway and Sloane [14]) or the ‘shaping’ process (see Sommer et al [6]); this process includes linearly acting upon this said integer vector by means of a Lattice Generator matrix, resulting in a real vector (i.e. lattice point) positioned inside said specified closed space region.
The Lattice Generator matrix columns (or in some notations, its rows) comprise in fact a basis vectors set of the Lattice Code. At the receive side, due to transmission channel and receiver effects, a noisy version of the transmitted lattice point is received. This vector is usually processed by a so called Lattice Detection method, associated with the selected Lattice Code and a lattice point, hopefully the originally transmitted, is recovered. This is then decoded by a Lattice Decoding process, the counterpart of the fore mentioned Lattice Encoding process (Nissani [3], [4], [5]) and the received information bits are then delivered to the user.
Use of Lattice Coding in communication applications has been limited so far (see Lang and Longstaff [7]). This is probably due to several factors: a. relatively few Lattice Codes were available with known and feasible Lattice Detection methods, which resulted in little flexibility to system designers, b. no general method was known for the above mentioned Lattice Encoding process (see Forney et al. [8] and, again, Sommer et al [6]); c. only moderate coding gain was achieved by those few Lattice Codes (such as the Leech lattice, denoted L 24 ) with feasible detection methods.
Most recently, Lattice Codes were discovered for which BER performance approximates the Shannon Capacity bounds. These Lattice Codes, called Low Density Lattice Codes (LDLC, see Sommer et al [6]) closely resemble (and were actually inspired by) the so called Low Density Parity Check (LDPC) binary codes (see Gallager [9]), which have gained wide acceptance in recent years. Like LDPC, LDLC are characterized by a sparse Lattice Generator matrix inverse (or sometimes, sparse Lattice Generator matrix itself); and the Lattice Detection process (i.e. the said process of association of the noisy received vector to a near, hopefully the nearest, lattice point) is done by probabilistic methods (e.g. message passing or belief propagation), closely resembling those of LDPC.
Concurrently, the long time said open Lattice Encoding and Decoding problem was solved in recent years by a computationally efficient, universal (i.e. suitable to any lattice) method (see Nissani [3], [4] and [5]).
The fore mentioned obstacles preventing Lattice Code acceptance seem to have now been solved: a. an arbitrary variety of Lattice Codes of different dimensions with efficient Lattice Detection methods are now developed (Yona and Feder [10]), which trade off coding gain for latency and complexity, b. a universal and computationally efficient Lattice Encoding and Decoding method was devised (Nissani [3], [4] and [5]), and c. Lattice Codes with high coding gain (close to Shannon Capacity) are contained in this family.
Outstandingly, these codes get close to Shannon Capacity bounds at no information rate penalty at all, so they may be naturally considered as a coding method of choice as bandwidth and spectrum are generally a scarce resource.
Since MIMO is a well based keystone of wireless, for Lattice Coding (and other signal space coding methods) to be adopted, it should be able to be seamlessly integrated with MIMO transmission systems, without incurring any BER performance degradation. As was already pointed out (see Sommer et al [6]) and as will be described in the sequel, direct (‘natural’ or ‘nave’) integration between MIMO and Lattice Coding will in general cause severe link (BER) performance problems.
The proposed invention presents a simple and feasible solution to these problems which enables Lattice Coded information to be transmitted through MIMO channels with no link performance penalty, i.e. practically achieving the designed coding gain.
It should be noted again that while the term Lattice Coding is used along this proposed invention, the method proposed herein is equally applicable to any other signal space coding scheme characterized by Euclidean or related metrics as the distance measure between different transmission messages.
OBJECTIVES AND ADVANTAGES OF THE INVENTION
It is the main objective of this proposed invention to present a method and corresponding apparatus to enable seamless and effective transmission of Lattice Coded information through MIMO channels.
It is the main advantage of this proposed invention to offer a simple method and corresponding apparatus which may achieve the designed Lattice Code coding gain even when transmitted across MIMO channels.
SUMMARY OF THE INVENTION
Direct or ‘natural’ integration of MIMO and Lattice Coding in a transmission system incurs the mapping of Lattice Code points, into MIMO transmitted vectors (MIMO lattice points, denoted m-lattice points in the sequel to prevent confusion). The MIMO signal is then propagated, in its way to the MIMO receiver, through a channel. This propagation causes a distortion of the MIMO m-lattice, so that the received m-lattice point is (aside from noise) a scaled and rotated version of the transmitted m-lattice point. This in turn, when reflected back into the Lattice Code points, causes the received lattice to have different distance properties than the original Lattice Code, i.e. the transmitted lattice; since in many Lattice Codes the distance between lattice points is tightly controlled for optimal coding gain, the change in this distance would usually cause significant coding gain degradation.
In addition, the said received lattice is now represented by a different Lattice Generator matrix. In the case of LDLC this change in Lattice Generator matrix is reflected in loss of sparseness and other properties of the Lattice Generator matrix inverse (or the Lattice Generator matrix itself, depending on implementation), which are essential for state of the art LDLC detection methods; these problems are well known (see e.g. Sommer et al [6] where it is stated that, ‘ . . . Therefore, the usage of LDLC for MIMO systems is a topic for further research’).
It is reasonably assumed, in the context of this proposed invention, that the MIMO propagation channel, represented by a matrix, is nearly time invariant during the transmission of a packet or burst, or, if varying, its time variations are reasonably tracked by means which are well known to those skilled in the art. It is also assumed in the context of the present invention that an estimate of the MIMO channel matrix is made available to the receiver prior to the beginning of the Lattice Code detection process, with estimate updates during transmission if required.
A vital observation in the context of the present invention is that while the distance ratios between, say, several neighboring received m-lattice points, is not conserved (relative to the distance ratios of the corresponding transmission m-lattice points) the general lattice structure is conserved. This means, for example, that the ratio of the distances between 3 collinear received m-lattice points, and in particular between m-lattice points residing along a single m-lattice basis vector, are, actually preserved (while the ratio of distances between non-collinear points is not preserved).
This key observation is exploited in the present invention: in a selected embodiment, instead of encoding the information by means of a single Lattice Code and then directly mapping the resulting lattice points into the m-lattice points, the information bits block is splitted into several sub-blocks (specifically at least as many sub-blocks as the MIMO m-lattice dimension). Each of these sub-blocks is then separately Lattice Encoded by existing means (such as Nissani [3], [4] and [5]) and each resulting Lattice Code lattice point vector is then serialized; the serialized coordinates (scalar numbers) of each such Lattice Code vector are sequentially transmitted, during consequent time slots, on a selected dimension of the MIMO m-lattice (the term ‘dimension’ as used in the sequel interchangeably denotes the minimal number of spanning vectors required to span the MIMO signal space, or any distinct MIMO space spanning vector; the actual meaning should be clear from the context).
The transmitted m-lattice vectors are propagated and distorted by the transmission channel. The distorted received m-lattice points are not immediately detected as in the direct or ‘natural’ said method of MIMO and Lattice Codes integration. Rather, in said selected embodiment of this proposed invention, each m-lattice received vector is de-rotated (and de-scaled) by means of the inverse of an estimate of the channel matrix; the resultant vector is (up to the estimated channel matrix error) a noisy version of the transmitted m-lattice point. These vectors, received and gathered during consequent time slots (as many as the dimension of the Lattice Code), are separated into their components (as many as the MIMO m-lattice dimension); each separated sub-block is then parallelized and input into a Lattice Code detector.
Since each Lattice Code is fed by lattice coordinates which were all transmitted along a single MIMO dimension, the distances of the original transmitted Lattice Code are preserved (up to errors caused by imperfect channel estimate). The Lattice Code lattice points may then be detected by well known specialized (as opposed to universal) Lattice Code detectors (such as Yona and Feder [10]) and achieve similar BER results as if transmitted through a simple (i.e. non-MIMO) channel. The detected lattice points are then Lattice Decoded (again Nissani [3], [4] and [5]). Finally, since different MIMO basis vectors are affected by different noise variance (as will be explained in the sequel), then different Lattice Code points will generally yield different BER; if this is undesirable interleaver and de-interleaver functions may be inserted at the transmitter and receiver side correspondingly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 presents transmitted and received m-lattices of a MIMO transmission system.
FIG. 2 shows a Lattice Code and the effects of a direct or ‘natural’ integration of MIMO and Lattice Codes, in accordance with current art.
FIG. 3 describes a selected embodiment of the proposed invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 presents transmission and reception MIMO m-lattices related to the exposition of the present invention. A transmission m-lattice of a simple (M=) 2 dimensional MIMO system, 4-PAM (Pulse Amplitude Modulation) real modulation is depicted in 10 of FIG. 1 . Generalization to M>2 sub-streams and to more common complex modulations is straightforward and could be easily devised by anyone reasonably skilled in the art. Such transmission m-lattices are essentially an infinite set of regularly spaced points in a multi-dimensional space. Any m-lattice point x 101 can be conveniently described by means of an integer linear combination of basis column vectors a 1 102 and a 2 103 , namely
x=n 1 a 1 +n 2 a 2 =An (1)
where n=(n 1 n 2 ) t is any integer vector, A=[a 1 a 2 ] is a MIMO Lattice Generator matrix composed of the m-lattice basis vectors a 1 =(1 0) t 102 and a 2 =(0 1) t 103 , and where ‘( ) t ’ denotes the vector or matrix transpose operator.
In a typical MIMO communication system transmission constellations are confined to a bounded region 104 of the m-lattice space 10 , such as an hyper-cube (square in our simple case) or a hyper-sphere. An m-lattice vector x 101 can then be selected for transmission, subject to equation (1) and to the said confinement constraint, and then transmitted through the MIMO channel.
The array of received points shown in 11 of FIG. 1 , such as the point r 111 , though rotated and scaled by the random channel matrix H, maintain the general lattice structure. Any received point such as r 111 is expressed by
r=Hx=HAn=Bn=n 1 b 1 +n 2 b 2 (2)
where B=H A=[b 1 b 2 ]=[Ha 1 Ha 2 ] may be considered the reception m-lattice Generator Matrix, composed of reception basis vectors b 1 112 and b 2 113 , and where receiver noise has been momentarily omitted. Hence the array of received points maintains the general lattice structure, but the basis vectors of the reception m-lattice are rotated and scaled. This scaling and rotation is in general different for different basis vectors so that a different m-lattice with different distance properties than those of the transmitted m-lattice results.
It can be further observed from 11 of FIG. 1 that the reception bounded region 115 of the reception m-lattice 11 has been also scaled and rotated and is not an hyper-cube (square) anymore.
It should be still further observed that the transmitted m-lattice point x 101 of 10 described by its integer vector n (aside of its Lattice Generator matrix A) has been transformed to the received m-lattice point r 111 of 11 , residing inside the reception bounded region and preserving the same integer descriptive vector n. In a MIMO system any reception m-lattice point such as the point r 111 is also affected by receiver noise, so that the actual received point y 115 is
y=r+z=B n+z (3)
where the noise z is usually assumed to be i.i.d. and normally distributed.
It is the main function of an optimal MIMO Lattice Detector to associate any noisy received vector such as y 115 of 11 to the closest reception m-lattice point, such as r 111 in 11 of FIG. 1 . Since the transmission channel is usually random, the received m-lattice is of general (i.e. not a-priori specified) structure. Universal Lattice Detection methods for such general m-lattices can be used in these cases, such as the well known Sphere Decoding (see Viterbo and Boutros [11]) or the more efficient Directional Lattice Descent method (see Nissani [12]). Another, simple universal Lattice Detection method exists, denoted Zero Forcing, by which the said received vector y is first de-rotated by the inverse of a channel matrix estimate ^H −1 (the superscript ‘^’ here and elsewhere denotes an estimate) and then rounded or ‘sliced’; however, said de-rotation has the severe effect of correlating the fore mentioned receiver i.i.d. noise z (transforming it into the ‘colored’ ^H −1 z noise) and significantly modifying the optimal decision surfaces (see e.g. Duda and Hart [15]), so that the resulting BER is severely impaired (relative to optimal detection).
The transmitted m-lattice 10 of FIG. 1 can be also interpreted as a Lattice Code of dimension L=2, with orthogonal basis vectors (i.e. with A=I, the identity matrix) and lattice points p=A n. This Lattice Code is called the cubic or integer lattice, and is usually denoted by Z L (i.e. Z 2 since L=2 in our simple example). Since no special effort is made in efficiently placing the lattice points of Z 2 so that a greater distance between neighboring lattice points results (while maintaining the same number of points in a given volume), then this trivial Lattice Code is also usually denoted as ‘uncoded’ transmission.
Interpreting 10 of FIG. 1 as a Lattice Code shows that direct or ‘natural’ MIMO and Lattice Code integration implies in fact, in the simple case where the MIMO and Lattice Codes dimensions are equal (i.e. L=M), just simply transmitting the lattice point itself, i.e. setting the transmitted vector x=p. In contrast with the proposed invention, as will be shown in the sequel, a single Lattice Code point is calculated at a time and is directly mapped into the MIMO m-lattice transmission vector (or consecutive vectors if L>M).
Denote by N the number of possible different messages carried by a Lattice Code, that is the number of Lattice Code points enclosed in said lattice (say hyper-cubic) bounded region such as 104 of 10 of FIG. 1 . The number of information bits carried by each such message is log 2 (N); and the number of information bits per dimension of the said Lattice Code, denoted by D, is D=log 2 (N)/L where L is (as defined above) the Lattice Code dimension. By inspection of 104 of 10 of FIG. 1 we note that N=16, and since L=2 (in this illustrative case) D=2 (D needs not be an integer in the general case, see e.g. Nissani [3], [4], [5]).
We now turn our attention to FIG. 2 which illustrates the severe problem (pointed out by e.g. Sommer et al [6] as mentioned above) resulting from directly or ‘naturally’ integrating MIMO and Lattice Codes. Refer to 20 of FIG. 2 , which we shall first interpret as a Lattice Code with generator matrix A=[a 1 a 2 ] with basis vectors a 1 =(1 0) t 202 and a 2 =(−½ sqrt(3)/2) t 203 . This is the densest lattice in R 2 : a specified bounded region such as the hyper-cube 204 is able to contain a given number of lattice points with maximal distance between neighboring points (compared with any other lattice in R 2 ). This Lattice Code is usually denoted A 2 and its fore mentioned distance property ensures the highest coding gain out of all other lattices in R 2 (though still low, because of its small dimension L=2).
As with the cubic lattice of FIG. 1 , its lattice points such as p 201 may be described by p=A n, with n an integer vector. Lattice Encoding, that is mapping between binary information bits and an integer vector n so that the resulting point p is confined to a bounded region of the lattice space (such as an hyper-cube 204 of 20 ) is not trivial anymore as was for the cubic lattice depicted in 10 of FIG. 1 and should be implemented by such means as described in Nissani [3], [4] and [5].
Direct or ‘natural’ MIMO and Lattice Code integration, just as in the said case of the cubic Lattice Code of FIG. 1 above, would mean to simply transmit the Lattice Code points, i.e. x=p (assuming for simplicity as before that L=M).
In the more general and typical case, with L>M, such direct MIMO and Lattice Code integration would imply, in terms of implementation: a. picking D×L information bits, b. Lattice Encoding said bits into a single confined Lattice Code point of dimension L, c. mapping said Lattice Code point into MIMO m-lattice points, M coordinates at a time slot, till all L coordinates are used (L/M total time slots, assuming for simplicity and w.l.o.g. that L/M is an integer), d. transmitting the m-lattice point through a channel H during said L/M time slots, e. detecting at the receiver side, either a single received m-lattice vector at each time slot, or the aggregate of L/M m-lattice vectors received over consecutive time slots, in both said cases by means of a said universal Lattice Detector, and, f. Lattice Decoding the detected vector(s) back into L×D information bits.
Note that aggregating said L/M noisy received MIMO vectors (such as 211 of 21 ) during L/M time slots as mentioned above, and then executing said Lattice Code specialized Lattice Detection (rather than said universal Lattice Detection as described above) is not an option since (as will momentarily be described) the received Lattice Code Generator matrix will in general be significantly modified by the transmission channel.
The transmitted m-lattice vector x 201 is transmitted through a MIMO propagation channel described by its matrix H. Just as in FIG. 1 above, the channel separately rotates and scales each of the basis vectors as is shown by b 1 212 and b 2 213 of 21 of FIG. 2 . This may severely distort the carefully designed distance properties of the original (transmitted) Lattice Code A 2 which in general results in significantly degraded BER and coding gain.
In addition, at the receiver side, the Lattice Code generator matrix is modified from A to B=H A. In the case of LDLC this causes loss of said sparseness property in the Lattice Generator matrix inverse (or in some Lattice Code implementations, in the generator matrix itself) which is essential for efficient Lattice Detection. Similarly, for other Lattice Codes, characterized by algebraic detection methods (such as the Leech L 24 lattice, see Lang and Longstaff [7]) this generator matrix modification impedes application of known and efficient detection methods. As result of this, a noisy received vector such as 211 of 21 of FIG. 2 cannot be efficiently associated to its nearest Lattice Code point 215 of 21 .
It should be noted that these severe problems of distances distortion and Lattice Generator matrix modification similarly occur for the (more typical) cases whereby L>M in which the direct or ‘natural’ integration of MIMO and Lattice Codes is implemented by mapping coordinates of the Lattice Code vector into an m-lattice point, a few coordinates at a time slot, during consequent time slots, till the whole vector is transmitted (as described above). Similarly, the same problems persist regardless of whether the lattices (either Lattice Code, MIMO m-lattice or both) are defined over the real or complex numbers fields.
Finally, it should be noted that although distances between neighboring received m-lattice points is severely distorted, the general lattice structure of the received points set is preserved. In particular neighboring collinear points (e.g. points along any selected m-lattice basis vector) preserve, after reception, equal distances between themselves. This observation is vital to our herein proposed invention.
It is the main idea behind this invention to a. split an information data bits block into M (or more) separate sub-blocks, i.e. (at least) as many as the MIMO dimension, optionally interleaved, b. separately code each said sub-block by means of a Lattice Code resulting in M (or more) Lattice Code points, each of dimension L, c. transmit the coordinates of each said Lattice Code point, sequentially during L time slots, each said Lattice Code point through a selected MIMO m-lattice dimension. Since, as explained above in the context of FIG. 2 , the MIMO channel preserves the general lattice structure, so that distances along basis vectors are conserved (up to a scalar multiplication) then the precise and original Lattice Code structure is preserved, efficient specialized Lattice Detection methods can be applied, and the maximal possible coding gain can be achieved.
We refer now to FIG. 3 which depicts a selected embodiment of the herein proposed invention. A block, denoted d, of information bits, of length L×D×M is fed into a block Interleaver 301 which spreads (for reasons that will become clear ahead) the information bits d into M sub-blocks, denoted i=1, 2, . . . , M, each of length L×D. Each sub-block e i is separately Lattice Encoded into a distinct lattice point integer vector descriptor n i , i=1, 2, . . . , M by a Lattice Encoder E 302 (which implements a method such as Nissani [3], [4], [5]); the said lattice point descriptors n i are multiplied by the Lattice Code generator matrix A as indicated by 303 ; by merit of said Lattice Encoding E 302 the resulting lattice point p i, =A n i , i=1, 2, . . . , M, is confined to a bounded region of the lattice space such as an hyper-cube or hyper-sphere. Said M lattice points p i , are fed as L dimensional vectors into Parallel to Serial (P2S) converters 304 , from which they exit, one coordinate at each transmission time slot. These M coordinates are represented by x i (l) i=1, 2, . . . , M, l=1, 2, . . . , L (index l is omitted from FIG. 3 for the sake of clarity); the vector x(l) is in fact the MIMO transmitted m-lattice vector at a given time slot 1 .
The transmitted MIMO vector x(l) is propagated through the channel, represented by the matrix H 305 . As mentioned above in the context of FIGS. 1 and 2 , the channel rotates and scales the transmitted vector x(l) and adds noise z(l), usually assumed normal and i.i.d., thus
y ( l )= H ×( l )+ z ( l ) l= 1,2, . . . , L (4)
where the channel matrix H 305 is assumed memoryless, and constant or slowly varying with time.
The M components of the noise vector z(l) have, by usual assumption, identical variance; however, since the m-lattice basis vectors have been separately scaled, these said vectors will generally vary in their norms, hence the Signal-to-Noise Ratio (SNR) of different m-lattice basis vectors will generally vary; this fact will be elaborated in later paragraphs.
In the selected embodiment of our present invention, the received vector y(l) will not be detected by a (universal) MIMO Lattice Detector as in the direct or ‘natural’ MIMO and Lattice Code integration scheme described above in the context of FIG. 2 .
Instead, in said selected embodiment of this proposed invention, each received vector y(l) is de-rotated (and de-scaled) by the channel matrix estimate, denoted ^H −1 306 . This channel matrix estimate is calculated in Channel Estimator 311 by means well known to those skilled in the art; if the channel H is reasonably time invariant during the transmission of L time slots then a single estimate is sufficient; otherwise channel estimate updates may be calculated and fed into 306 . Following this de-rotation we have
w ( l )=^ H −1 Hx ( l )+ z ( l )≅ x ( l )+^ H −1 z ( l ) l= 1,2, . . . , L (5)
so w(l) is a noisy (due to the noise (^H −1 z(l)) and approximate (due to channel estimate errors) reconstruction of the transmitted vector x(l).
It is important to note, and a key feature of this proposed invention, that although the de-rotated noise vector is now correlated (‘colored’) as was noted above in the context of FIG. 1 , this is not a degrading effect anymore, since detection will not be conducted upon vectors w(l) of dimension M but upon vectors q i of dimension L (as will be momentarily described) all affected by i.i.d. noise.
The different components of the de-rotated vectors w(l) are in general still subject to different SNR as mentioned above.
The de-rotated vectors w(l) are hereon treated component-wise; for each of M m-lattice dimensions, L consecutive components w i (l), i=1, 2 . . . , M, l=1, 2 . . . , L, are received during L time slots and are converted into a vector q i of dimension L by means of a Serial-to-Parallel (S2P) converter 307 . As mentioned above the L components of each of these M vectors are affected by statistically independent (assuming memoryless channel, as is usually the case) noise of identical variance (though, as mentioned above, the variances of different vectors q i , i=1, 2 . . . , M, will generally differ).
Since the Lattice Code original structure is precisely preserved during this process (except for implementation impairments such as channel estimator errors) as explained above, then each of these M vectors q i can be detected by means of a specialized Lattice Detector 308 resulting in an estimated integer vector ^n i , i=1, 2, . . . , M; for example, if the selected Lattice Code is an LDLC then Lattice Detector 308 may be implemented by methods such as those described in Yona and Feder [10], etc. Each of the M detected integer vectors ^n i , i=1, 2 . . . , M is then decoded by a Lattice Decoder D 309 , the inverse operation of said Lattice Encoder E 302 , resulting in M binary estimated sub-blocks ^e i of length L×D bits. Finally these M sub-blocks are de-interleaved by means of De-Interleaver 310 resulting in estimated information block ^d.
As described above, the different received m-lattice basis vectors have in general different SNR; to evenly distribute detection errors in the block ^d the selected embodiment of the present invention included an Interleaver and De-Interleaver pair; other embodiments of this invention may omit this operation.
In the selected embodiment of the proposed invention a channel de-rotation (and de-scaling) ^H −1 306 operation was included at the receiver side. In other embodiments the received vector y may be instead projected upon the distinct m-lattice basis vectors b i ; in this case the noise of different m-lattice dimensions will be of equal variance, but the SNR of different noisy Lattice Code points q i will still vary due to said basis vectors usually different norms, resulting in coding gain (of each individual Lattice Code) similar to that of the selected embodiment.
In some embodiments of the proposed invention the depicted parallel machinery 302 to 304 at the transmitter side and/or 307 to 309 at the receiver side can be implemented by shared resources and need not be physically distinct entities.
While the selected embodiment of the proposed invention made explicit use of Lattice Codes, this proposed invention should be equally applicable to other signal space coding techniques (such as, but not limited to, those referred above); in particular, these include all those that make use of Euclidean or related metrics (rather than Hamming or related binary metrics) to distinguish amongst different messages. Adaptation to these other said techniques should be easily done by those skilled in the art.
Other embodiments of the proposed invention may include transmitted and received vectors defined over the complex numbers field (rather than over the real numbers field as in the selected embodiment); adaptations to such complex constellations (and associated channel matrix) should be easily made by those skilled in the art.
The present proposed invention is equally applicable to single carrier MIMO as well as to other, multi-carrier schemes (such as MIMO-OFDM); adaptations to these schemes should be easily made by those skilled in the art.
Some MIMO schemes are based upon non-availability of channel state information at the transmitter side; some are based upon knowledge, full or partial of channel state information at said transmitter side. The proposed invention is equally applicable to both, and adaptations to each should be easily made by those skilled in the art.
The selected embodiment of the proposed invention assumed an equal number of antenna elements at both the transmitter and receiver sides of the MIMO system, or equivalently, a square channel matrix H 305 . Other embodiments may contain a different number of antenna elements at each side (equivalently, a non-square channel matrix H 305 ); adaptations to these schemes should be easily made by those skilled in the art.
The selected embodiment of the proposed invention has assumed that identical Lattice Codes (represented by operators E 302 and A 303 in FIG. 3 ) are applied to all m-lattice dimensions. In other embodiments different Lattice Codes may be applied to different m-lattice dimensions, for example (but not limited to) where channel state information is available at the transmitter side; adaptations to these schemes should be easily made by those skilled in the art.
In the selected embodiment of the proposed invention the information block was divided into precisely as many sub-blocks as the dimension of said m-lattice. In other possible embodiments of this proposed invention the information block may be divided into a number of sub-blocks greater than said m-lattice dimension; in such embodiments more than a single Lattice Code would be encoded on some or all of m-lattice dimensions, the vital point still being that no Lattice Code be encoded and transmitted upon more than one single said m-lattice dimension. | A method and corresponding apparatus for signal space information encoding through a multi-input-multi-output communication system of given dimension, with no or little degradation in link performance (relative to non-multi-input-multi-output systems), said method and corresponding apparatus comprising, splitting said information into at least as many separate parts as said dimension of said multi-input-multi-output communication system, separately signal space encoding each of these said parts, and transmitting each of said separate encoding results on a selected dimension of said multi-input-multi-output communication system along sequential usages of the transmission channel. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for synthesis of nucleic acids, especially to a method for synthesis of nucleic acids by means of a polymerase chain reaction (hereinafter abbreviated as a PCR).
2. Description of the Related Art
A PCR method is a procedure capable of amplifying an intended DNA fragment as much as several hundred thousand-fold by repeating a process comprised of dissociation of a DNA strand into single strands, binding of primers with sandwiching a particular region of the DNA strand, and a DNA synthesis reaction by the action of a DNA polymerase. The PCR method is described in Japanese Laid-open Patent Publication No.S61-274697 which is an invention by Mullis et al.
A PCR procedure can be used as a highly sensitive method for analyzing nucleic acids in various samples, and particularly it can be used in analysis of nucleic acids in a sample derived from an animal body fluid. The PCR procedure is therefore used for such a purpose of diagnosis or monitoring of an infection, a hereditary disease, and a cancer. The PCR procedure is also suited to DNA typing tests for a transplantation, a paternity test, medical treatments based on an individual genetic information, and the like. For these purposes, a peripheral blood is often selected as a test object.
One drawback of the PCR procedure is that the reaction is inhibited by pigments, proteins, saccharides, or unknown contaminants. Namely, many DNA polymerases including TaqDNA polymerase derived from Thermus aquaticus, a typical thermostable DNA polymerase, are widely known to allow the PCR to be inhibited potently by even a trace amount of living body-derived contaminants existing in the PCR reaction solution. Therefore, the PCR procedure requires a process in which a cell(s), a protozoan (protozoa), a fungus (fungi), a bacterium (bacteria), a virus(es) and the like (hereinafter referred to as a gene inclusion body) are isolated from a subject and then nucleic acids are extracted from the gene inclusion body prior to a DNA amplification. Such process has conventionally been a procedure in which the gene inclusion body is decomposed using an enzyme, a surfactant, a chaotropic agent, or the like, and then nucleic acids are extracted from the decomposed product of the gene inclusion body using, for example, phenol or phenol/chloroform. Recently, an ion-exchange resin, a glass filter, or a reagent having an effect of agglutinating proteins is used in the step of the nucleic acid extraction.
It is difficult, however, to completely remove impurities by purifying nucleic acids in a sample using these procedures, and furthermore, an amount of nucleic acids in a sample recovered by these purification procedures often varies among experiments. For these reasons, a subsequent nucleic acid synthesis may sometimes be unsuccessful, especially when a content of the intended nucleic acid in the sample is low. In addition, these purification procedures involve complicated manipulations and are time-consuming, and there is a high opportunity for contamination during the procedures. Therefore, a simpler, more convenient and effective method of a sample pretreatment is desired in order to solve these problems.
SUMMARY OF THE INVENTION
Thus, an object of the present invention is to provide a novel method for removing nucleic acid synthesis inhibitory substances and thereby amplifying a nucleic acid in a sample efficiently.
The present inventor found that nucleic acid synthesis inhibitory substances in a biological sample can be removed by bringing the substances into contact with an insoluble polymer of a polyanion, and thus arrived at the present invention.
The present invention is a method for synthesis of nucleic acids to amplify an intended nucleic acid in a sample which comprises bringing the sample in advance into contact with an insoluble polymer of a polymer compound having a repeating structure containing at least one anion (polyanion) and/or a salt thereof (hereinafter collectively referred to as a polyanion).
The present invention is the method for synthesis of nucleic acids wherein the polyanion is a polymer compound having a repeating structure containing at least one sulfate group (polysulfate) and/or a salt thereof (hereinafter collectively referred to as a sulfated polymer).
The present invention is the method for synthesis of nucleic acids wherein the sulfated polymer is selected from the group consisting of sulfated polysaccharides and salts thereof (hereinafter collectively referred to as a sulfated polysaccharide).
The present invention is the method for synthesis of nucleic acids wherein the sulfated polysaccharide is selected from the group consisting of heparin and a salt thereof, and dextran sulfate and a salt thereof.
The present invention is the method for synthesis of nucleic acids wherein the sample is a living body-derived sample itself.
According to the present invention, by conducting a simple and convenient treatment in which a sample, such as serum or plasma, containing a lot of PCR inhibitory substances is brought in advance into contact with an insoluble polymer of a polyanion, it becomes possible to directly amplify an intended nucleic acid efficiently without undergoing a process of isolating and purifying nucleic acids from the sample. It becomes also possible by the present invention to perform procedures for nucleic acid synthesis more simply, conveniently and rapidly, and thereby reduce the opportunity for contamination.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an electrophoretogram of amplified products obtained by the PCR in which a serum is directly added to a PCR reaction solution.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a method for synthesis of nucleic acids to amplify an intended nucleic acid in a sample which comprises bringing the sample into contact with an insoluble polymer of a polyanion prior to a nucleic acid amplification reaction.
As used herein, the term “polyanion” refers to a polymer compound and a salt thereof, having a repeating structure containing at least one anion. Examples of the anion include, but not limited to, sulfate, sulfite, phosphate, carboxyl, and thiocarboxylic groups. Particularly preferred is a polymer compound having a repeating structure containing at least one sulfate group and a salt thereof (a sulfated polymer).
As the sulfated polymer, a sulfated polysaccharide is preferred. The preferred sulfated polysaccharide includes, but not limited to, heparin and a salt thereof as well as dextran sulfate and a salt thereof. Other sulfated polysaccharides such as heparan sulfate, chondroitin sulfate, dermatan sulfate, funoran, sulfated agarose, carrageenan, porphyran, fucoidan, and sulfated curdlan may also be used.
The sulfated polymers other than those mentioned above may include, but not limited to, polyvinyl sulfate and a salt thereof.
Examples of the salts include, but not limited to, sodium and potassium salts.
Insoluble polymers of the polyanion may be used individually or as a combination of several kinds of such polymers. These insoluble polymers do not need to be homogeneous, and they may be composite insoluble polymers containing the polyanion, or the polyanions attached to some insoluble support.
In order to bring a sample in advance into contact with an insoluble polymer of a polyanion, various procedures may be adopted, including, but not limited to, the following methods. For example, the sample may be passed through a column packed with said insoluble polymer or through a filter made of said insoluble polymer. Alternatively, said insoluble polymer and the sample may be put into a container to mix together, and then the sample may be recovered from the container. Furthermore, the sample may also be put into a container of which inner wall is coated with said insoluble polymer or into a container which itself is made of said insoluble polymer, and then recovered from the container. As used herein, the phrase “in advance” means the step is done before an amplification reaction, and the sample is brought into contact with the insoluble polymer of the polyanion before the sample is added to a reaction solution for gene amplification.
In the present invention, the term “sample” refers to a living body-derived sample itself or a living body-derived sample which is subjected to some treatment, and the term “living body-derived sample” refers to an animal or a plant tissue, a body fluid, an excretion, and the like. The body fluids include blood, cerebrospinal fluid, saliva, and milk, and the excretions include feces, urine, and sweat, although they are not so limited. The living body-derived sample may, but not necessarily, be directly added to a reaction solution for gene amplification without particular treatments other than bringing it into contact with the insoluble polymer of the polyanion, other treatments such as a nucleic acid extraction may also be additionally adopted in combination.
The reaction solution for gene amplification conventionally contains a pH buffer as well as salts such as MgCl 2 and KCl, primers, deoxyribonucleotides, and a nucleic acid polymerase. The salts mentioned above may be replaced with other salts as appropriate. In addition, various substances including proteins such as gelatin and albumin and dimethyl sulfoxide are sometimes added.
The pH buffer is prepared by a combination of tris(hydroxymethyl)aminomethane and a mineral acid such as hydrochloric, nitric, or sulfuric acid, and a preferred mineral acid is hydrochloric acid. Alternatively, various other pH buffers, including pH buffers comprising a combination of Tricine, CAPSO (3-N-cyclohexylamino-2-hydroxypropanesulfonic acid), or CHES (2-(cyclohexylamino)ethanesulfonic acid) and caustic soda or caustic potash, may be used. The pH-adjusted buffer is used at a concentration between 10 mM and 100 mM in the reaction solution for gene amplification.
The term “primer” refers to an oligonucleotide that acts as an initiation site of synthesis in the presence of nucleic acids, reagents for amplification and other substances. The primer is desirably single-stranded, and a double-stranded primer may also be used. When the primer is double-stranded, it is desirable to convert it into its single-stranded form prior to the amplification reaction. The primers may be synthesized using known methods, or may be isolated from living organisms.
The term “nucleic acid polymerase” means an enzyme that synthesizes nucleic acids by adding deoxyribonucleotides or a chemical synthesis system doing so. Suitable nucleic acid polymerases include, but not limited to, DNA polymerase I derived from E. coli, the Klenow fragment of a DNA polymerase derived from E. coli, T4 DNA polymerase, TaqDNA polymerase, T. litoralis DNA polymerase, TthDNA polymerase, PfuDNA polymerase, and a reverse transcriptase.
Furthermore, according to the present invention, pH adjustment of the reaction solution for gene amplification produces a synergistic effect. For example, at a temperature of 25° C., the pH is 8.1 or more, and preferably from 8.5 to 9.5.
In the present invention, polyamines may also be added to the reaction solution for gene amplification.
The steps constituting a method for synthesis of nucleic acids of the present invention are not different from those steps in the conventional methods with the exception that the sample is brought into contact with the insoluble polymer of the polyanion, the sulfated polymer, or the sulfated polysaccharide, in advance of amplification of nucleic acids in the sample. Thus, a living body-derived sample is used as a template for nucleic acid synthesis directly after being treated in the manner described above, or after being subjected to the above treatment combined with other treatments such as the nucleic acid extraction. For example, when the PCR is used as a method for synthesis of nucleic acids, an intended double-stranded DNA fragment to be amplified is firstly heat-denatured into single-stranded DNAs (a denaturation step). Next, primers by which the region to be amplified is bounded are allowed to hybridize (an annealing step). Then, DNA polymerase is allowed to act in the presence of four deoxyribonucleotides (dATP, dGTP, dCTP and dTTP) to conduct a primer extension reaction (a polymerization step).
EXAMPLES
The present invention is further described in the following examples which are not intended to restrict the invention.
A human serum was passed through a spin column packed with sulfated dextran gel, Dextran beads, sulfated D5650 (SIGMA, Missouri, USA), and recovered as a sulfated dextran gel-treated serum.
To a PCR reaction solution (50 μl), 10 to 0 μl volume of an untreated serum and the sulfated dextran gel-treated serum were added to conduct the PCR. As a template for the PCR, cDNA reverse transcribed from 5,000 copies of GeneAmplimer pAW109RNA (PE Biosystems, Foster, USA) was used. Primers for the PCR were DM151 and DM152 (PE Biosystems, Foster, USA), of which sequences are as below. The PCR using these two primers may produce a 308 bp amplification product.
DM151, SEQ ID. NO. 1
5′ GTCTCTGAATCAGAAATCCTTCTATC 3′
DM152, SEQ ID. NO. 2
5° CATGTCAAATTTCACTGCTTCATCC 3
The PCR reaction solution used contained 10 mM Tris-HCl, 50 mM KCl, 1.5 mM MgCl 2 , 200 μM each of dATP, dCTP, dGTP and dTTP, 0.4 μM each of the primers, and 1.25 units/50 μl of Taq DNA polymerase (TaKaRa Taq: Takara Shuzo, Kyoto, Japan).
The PCR involved a preheating at 94° C. for 3 minutes, 40 cycles each of which consists 30 seconds at 94° C. followed by 30 seconds at 60° C. followed by 1 minute at 72° C., and then the final polymerization at 72° C. for 7 minutes. After the completion of the PCR, 5 μl of the reaction solution was subjected to an electrophoresis on a 2.5% agarose gel in TAE (40 mM Tris-acetate, 1 mM EDTA) containing 0.5 μg/ml ethidium bromide to detect the amplification products.
FIG. 1 shows the electrophoretogram of amplified products obtained by the PCR in which serum was directly added to the PCR reaction solution. In the FIGURE, a lane M indicates size makers (250 ng of φ X174-RF DNA cleaved with HincII); a lane P indicates a positive control (without added serum); a lane N indicates a negative control; lanes 1 and 9 indicate the results obtained with 10 μl serum; lanes 2 and 10 indicate the results obtained with 5 μl serum; lanes 3 and 11 indicate the results obtained with 2.5 μl serum; lanes 4 and 12 indicate the results obtained with 1.25 μl serum; lanes 5 and 13 indicate the results obtained with 0.63 μl serum; lanes 6 and 14 indicate the results obtained with 0.31 μl serum; lanes 7 and 15 indicates the results obtained with 0.16 μl serum; and lanes 8 and 16 indicate the results obtained with 0.08 μl serum. The lanes 1 to 8 indicates the results obtained with the untreated serum and the lanes 9 to 16 indicate the results obtained with the sulfated dextran gel-treated serum.
As a result, it can be seen that the untreated serum exhibits extremely potent PCR inhibition so that no PCR amplification product is obtained with any amount of added serum, whereas the sulfated dextran gel-treated serum satisfactorily provides the PCR amplification product with any of the amounts of added serum.
2
1
26
DNA
Artificial Sequence
misc_feature
(1)..(26)
Artificial primer DM151 (PE Biosystems,
Foster, USA)
1
gtctctgaat cagaaatcct tctatc 26
2
25
DNA
Artificial Sequence
misc_feature
(1)..(25)
Artificial primer DM152 (PE Biosystems,
Foster, USA)
2
catgtcaaat ttcactgctt catcc 25 | An object of the present invention is to provide a novel method for suppressing the action of nucleic acid synthesis inhibitory substances and thereby amplifying a nucleic acid in a sample efficiently.
According to the present invention, in a method for synthesis of nucleic acids to amplify an intended nucleic acid in a sample, the sample is brought in advance into contact with an insoluble polymer of a polyanion, a sulfated polymer or a sulfated polysaccharide, to remove nucleic acid synthesis inhibitory substances. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application No. PCT/EP2007/058476 filed Aug. 15, 2007 and which claims the benefit of Finland Patent Application No. 20065557, the disclosures of all applications being incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for filling and cleaning a pulp tower. The invention is most suitable for filling and cleaning high-consistency pulp towers, bleaching towers, storage tanks and similar towers containing fiber suspensions, within the wood-processing industry.
Pulp towers within the wood-processing industry are in most cases tanks containing high-consistency pulp, whose consistency is about 10-20 percent, occasionally also pulp of low consistency, and which are used, e.g., for pulp storage or processing. Moreover, pulp towers are used as a blow tank for some devices or to store, e.g., pulp arriving periodically from batch digesters, which pulp is used as a steady flow in following processing devices. In other words, it is characteristic of the towers of the invention that they are basically large (diameter is generally on the order of 4-12 meters, and their height around 20-30 meters, although both smaller and larger towers exist), and that their surface level varies greatly, even if in most cases they have an optimal surface level, and it is generally desired to maintain the pulp surface at that level.
Many problems have been observed concerning the use of these towers or tanks. They relate mainly to the filling or emptying of the towers, or the inside fouling of the tower due to the stored or processed material adhering to the wall of the tower. In the following, the focus will be on discussing how the tower is filled and its fouling prevented, which is the subject matter of the present invention.
Many different solutions for filling the towers of the type mentioned above are previously known. The oldest known methods consist in pumping pulp to the top of the tower and allowing it to fall more or less directly downward. If pulp is allowed to fall directly downward on top of existing pulp, it is obvious that the pulp falling from above will pass through the surface of the pulp layer in the tower and penetrate deep into the old pulp. This gives rise to many disadvantages. First of all, if pulp dilution is performed at the tower bottom, as is very often the case, the pulp fed into the tower may penetrate as far as to the dilution zone. Hence pulp is discharged uncontrollably into the dilution zone, and dilution uniformity no longer corresponds to the requirements of the apparatus downstream of the tower. Another problem is that the pulp penetrating into the old pulp drifts closer to the tower discharge opening than does the pulp already in the tower, so that the content of the tower will not be evenly changed-instead a part of the pulp is carried out of the tower in a few minutes while a part of the pulp remains in the tower in the worst case even for days or weeks. More problems ensue in turn from this. First of all, it is impossible to imagine that pulp staying in the tower for days or even weeks may retain a quality similar to that of fresh pulp. Secondly, performing a complete change of grade in such towers may take days, or at best several hours, whereby the pulp discharged from the tower during the change period is a mixture of the new and old pulp grade. Depending on the subsequent use of the pulp, this so-called intermediate pulp may, in the worst case, be completely useless. Furthermore, old pulp remaining for a longer period in the same place in the tower, and new pulp flowing therethrough and deeper into the tower, gradually allow liquid to seep away from the surface of the pulp layer, whereby the surface layer hardens and may become more easily decayed. At the same time, old pulp also adheres more easily to the tower walls, from which it may detach as large solid pieces, which no longer disperse properly at the dilution zone of the tower.
Of course, the pulp may also be discharged into a distributor, e.g. a rotating disk arranged on top of the tower (e.g., SE-B-463 030), which distributes the pulp more evenly over the whole cross-section of the tower. While the distributor disperses the pulp flow into droplets, or at least relatively small-sized particles, a considerable amount of air is bound to the pulp as it descends, which air must be removed at a later stage of the process by vacuum pumps or by similar systems consuming a great deal of energy. In some towers, the pulp is carried from below to the bottom of a rotating disk provided with vanes (SE-C-502,971) so that the vanes spread the pulp over the cross-section of the tower. The publication states that the rotational speed of an electric motor used to rotate the disk may be changed in order to obtain the various degrees of spreading, whatever this means. This procedure is affected by the same problems as the rotating disk; i.e., the pulp forms droplets and a great deal of air is bound to the pulp. Another problem that may be mentioned is that rotating disks or the like described in the prior art do not allow for surface level variations in the tower, and instead are only suitable at some constant surface level, which practically in most cases means a full tower, whereby the disk or the like is placed only a little above the surface of the pulp in the tower. In an emptier tower the rotating disk throws the pulp against the wall of the tower, whereby it at the latest falls into drops and absorbs a great amount of air.
U.S. Pat. No. 4,278,496 discloses a filling arrangement for a bleaching tower within the pulp industry, wherein pulp is delivered to the tower through a rotating pipe fitting such that the pulp is spread in layers in the tower. However, this is a continuous process, where the surface level in the tower remains practically constant, and it is not critical that the pulp be spread out completely evenly into the tower, since the consistency of the pulp delivered to the tower is in the HC [high-consistency] area, in other words according to the publication, between 35 and 50 percent. With such high consistencies, there is no substantial danger of the pulp permeating deep into the pulp layer already in the tower, when the direction of pulp feed is not completely vertical. Nor is the mixing of the air into the pulp of any significance, since high-consistency pulp inherently contains large amounts of air.
A further problem that is not addressed concerns the storage of the bleached pulp. In some cases, it is namely of paramount importance that the pulp be discharged from both the bleaching tower and a possibly following storage or blow tank to ensure that the time the pulp stays in the tower or tank is kept constant. In other words, no part of the pulp may be left standing in the tower, since this will compromise its quality in one way or another. It was found, among other things, that the brightness of the pulp is reduced when the surface in the tower is lowered. This means in practice that the longer the pulp stays in the tower, the lower its brightness will be, or in the optimal case, the aim would be to discharge pulp from the tower in exactly the same order as it was fed in, or to maintain the time the pulp stays in the tower constant. It was furthermore observed that restarting the filling of the tower according to a prior-art method (direct blow via the top of the tower) increases the brightness of the pulp removed from the tower very quickly again. The only explanation for this would be that the blow coming from the tower continues almost directly to the tower discharge opening, whereby the pulp remaining in the tower will stay at the areas closer to the tower wall and not reach the tower discharge in time for removal.
Finnish patent application 971330 deals with a feed device, which aims to solve as efficiently as possible the problems of the previously described prior art devices. The apparatus in question includes a rotating feeder means arranged in connection with the upper part of the pulp tower, preferably its top or cover, preferably a central shaft relative to the tower, devices for its rotation, devices for delivering the pulp to the feeder means, as well as devices for controlling the operation of the feeder means. The devices for delivering pulp to the tower, except for the pipe leading through the cover, may also consist of a pipe extending through the side wall of the tower substantially to the central shaft of the tower, or the like. A pulp feeder means according to a preferred embodiment of the invention discussed in the publication consists of an elbow pipe arranged at the bottom end of a vertical pulp pipe or a similar entering the tower from above, the discharge opening of the elbow being substantially directed toward the wall of the tank or pulp tower. An important feature of the feeder means of the preferred embodiment described above is that its form does not disperse the pulp flow, i.e. produce sprinkles—instead the aim is to keep the pulp flow uniform, preventing as much as possible the binding of air among the pulp. It is not essential for the invention described in the publication that the discharge opening of the elbow pipe is in the horizontal direction, or tilted slightly up or down, but the direction of the pulp discharged from the discharge opening, along with the rotational speed of the feeder means, should ensure that under all operating conditions of the tower, pulp is discharged also to the proximity of the tower wall. The rotating device for the feeder means is preferably an electric motor with adjustable rotational speed, and optionally provided with a reduction gear. The control devices mentioned for the operation of the feeder means consist of a level sensor and a control unit, as standard equipment for each tower.
Thus it is possible with at least one or perhaps more of the devices mentioned above to feed pulp into the tower such that the tower is filled evenly from above, and the pulp fed to the tower cannot penetrate directly from the feed into the dilution zone.
Another problem with towers is, as pointed out previously, the adhesion of pulp to the tower wall. In practice, this always occurs, i.e. regardless of whichever device is used to feed pulp to the tower. When the pulp has adhered to the wall of the tower, it gradually dries and hardens, whereby it detaches as hard flaky lumps. These lumps do not necessarily disperse sufficiently in the dilution zone, but are instead carried forward to the pump and through it further into the process, where they hamper the process. Another disadvantage, which these cakes of pulp adhered to the wall of the tower may cause, is pulp deterioration. If the pulp remains in the tower for a sufficiently long period, the favorable conditions in the tower, i.e. temperature and moisture, promote deterioration of the pulp due to the influence of various microbes. The deterioration of the pulp may lead to greater pulp lots being deteriorated and also compromise the quality of the end product, unless the problem is noticed and corrected in a timely fashion.
For the above reasons, among other things, the cleanliness of the pulp towers is checked periodically, and the towers are cleaned either manually or by various washing devices arranged in the pulp towers, the washing operation being either continuous or intermittent. Among the washing methods used, manual washing, usually performed with a pressure washer, is the traditional way of handling this. This, however, involves problems of its own. First of all, it is almost impossible to perform washing when the process is ongoing, so that in practice cleaning is limited only to any downtime. Moreover since washing is manual, it is expensive and also somewhat hazardous work.
Thus, to clean the tower, various mechanical devices are proposed, most of which are based on the use of pressurized water or, more broadly, pressurized washing liquid in the washing of the tower. In principle, the devices come in three basic types. There are fixed nozzles and spray pipes, from which washing liquid is sprayed onto the desired portion of the tower wall. Moreover, there are rotating nozzle devices in connection with the cover of the tower, preferably arranged at the central shaft of the tower, where there generally are a large number of pressure liquid nozzles fixed on one or more stems producing the desired washing action in the tower. Further, fixed washing devices are known, consisting of a more or less round distributing chamber, a large number of nozzles being provided at its walls in such a way that they will cover the area to be washed in the inner surface of the tower.
The solutions known from the prior art, however, have their own problems. First of all, the fixed nozzles placed on separate sides of the tower have a relatively complex design requiring ramified liquid piping and numerous attachments, or in some cases, even numerous inlets through the cover of the tower. Also, when using the rotating feed devices known from the patent publications mentioned above, there is the risk of a pulp jet discharging from the feed devices breaking the nozzle pipes, or at least clogging the nozzles. A similar problem also concerns other solutions, in which the nozzle devices are exposed to a pulp jet. Thus, no matter how the washing devices according to the prior art are placed in the tower, there is great risk that they will either become clogged and/or break down due to the action of the pulp that is fed into the tower. Moreover, when the tower filling devices are located at the tower centerline, prior art nozzle solutions to be placed in the same way at the tower centerline, whether rotating or fixed, cannot be placed at the same point, but instead they need to be installed at the side of the tower centerline, thus in turn becoming exposed to the pulp jet.
SUMMARY OF THE INVENTION
The various problems of the previously described prior art solutions may be solved by the method and apparatus according to our invention.
Using the method and apparatus according to the invention, the filling and cleaning of the pulp tower may be done almost without any supervision at all. The washing apparatus is placed so that the pulp jet may neither break nor clog the washing device or its nozzles. The apparatus according to the invention is simple because it exploits already existing structures, as much as possible. Hence, if the tower already has a rotating feed device, its drive mechanism, and the attachment, sealing and bearings provided for it at the cover of the tower, may also be used when installing the device according to the invention.
The invention will be described below in more detail in reference to the attached drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is an elevational view of an exemplary apparatus for filling and cleaning a pulp tower.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus according to the invention comprises, according to the FIGURE, a filling unit 12 provided at the top of the pulp tower, preferably at the cover of the tower 10 , preferably placed centrally to the shaft of the tower, the filling unit being provided with a lid 14 , and one or more connections 16 located at the side of the unit for a pipe or pipes delivering pulp to the tower. Inside the unit 12 below this connection there is situated preferably, but not necessarily, a baffle 18 or a funnel guiding pulp entering the tower from the connection 16 in the direction of the shaft of the tower. The lid 14 of this filling unit is provided with a seal and a bearing 20 on a shaft 22 , below which there is fastened a scooping feeder means 24 , which may be, e.g., an elbow pipe, whose discharge opening or edge is substantially directed toward the wall of the tank or pulp tower. An important feature of a feeder used in connection with the invention is that in terms of its form, it does not disperse, i.e. sprinkle, the pulp flow—instead the aim is to keep the pulp flow uniform and prevent as much as possible binding of the air among the pulp. It is not essential, for the feeder means according to the present invention, whether the direction of feed of the feeder means 24 is horizontal, or titled slightly up or down, but the direction of the pulp discharged from the discharge opening, along with the rotational speed of the feeder means 24 , should ensure that under all operating conditions of the tower, pulp is discharged also to the proximity of the tower wall. The rotating device 26 of the feeder means, which according to a preferred embodiment of the invention is preferably a speed-adjustable electric motor, which may optionally be provided with a reduction gear, is arranged outside the tower either in connection with the unit 12 or at a distance from it (as shown in the FIGURE).
This feeder means 26 according to a preferred embodiment of the invention is rotated, e.g. so that the rotational speed of the feeder means is changed both relative to the tower diameter and according to the surface level in the tower. Thus, with each pulp surface level in the tower, the rotational speed of the feeder means is changed such that the feeding of the pulp to the tower occurs at its maximum distance to the vicinity of the tower wall, without the pulp jet hitting the tower wall, and at its minimum close to the shaft of the tower. When the surface level decreases from the one described above, the rotational speed of the feeder means is reduced, since already with the lower rotational speed the pulp jet discharging from the feeder means extends to the vicinity of the tower wall. Similarly, when the surface level rises, the rotational speed is increased.
The apparatus according to the invention includes furthermore an axial channel 28 arranged in the shaft 22 of the feeder means 24 , at the upper end of which channel there is a rotating coupling arrangement 30 for delivering washing liquid to the channel 28 . This coupling arrangement may be such, as represented in the FIGURE, that at a suitable point along the length of the shaft, there is a substantially radial opening in the shaft arranged for carrying washing liquid to a preferably, but not necessarily, central washing-liquid channel of the shaft, or the coupling arrangement may optionally be placed at the upper end of the shaft. It is, of course, possible also to arrange this channel outside the shaft, even if the technical implementation is significantly more complex. Similarly, the shaft 22 is equipped at its lower section with devices 32 for carrying washing liquid from the shaft channel 28 to nozzles. By means of washing-liquid jets discharging from the nozzles either the tower walls or the tower ceiling or both are kept clean. These devices 32 carrying washing liquid are formed by one or more pipes permanently fastened to the shaft or the feeder means 24 , which pipe/s is/are provided with nozzles preferably so that they will not directly contact the pulp that is fed into the tower. One possibility is therefore, as shown in the FIGURE, to place both the devices 32 carrying washing liquid and the nozzles at the back, so that in practice the feeder means 24 feeds the pulp in the opposite direction relative to the washing nozzles.
Depending on the size of the tower, the washing arrangement of the tower according to the invention may also, except for the nozzle pipe 32 in connection with the nozzle arrangement shown in the FIGURE, consist of a solution in which one or more pipes are fastened on the shaft 22 or the feeder means (when the pipe is fastened on the feeder means 24 , devices for carrying washing liquid from the channel 28 of the shaft 22 to the pipe are needed), the pipe/s carrying the washing liquid to a proper nozzle system located further away from the shaft, and the pipes at the same time acting as supports for the nozzle system—or of a solution where one or more nozzles are arranged in direct connection with the feeder means 24 , and by means of the nozzle/s, both the walls and the ceiling of the tower, or either one of them, may be kept clean. The nozzle arrangement mentioned above may, e.g., be a larger chamber located at the end of one or more pipe/s delivering washing liquid, several nozzles having been fastened at the walls of the chamber—or one or more transversal pipe/s provided with one or more nozzles, the pipe/s having been fastened to one or more pipe/s at its/their opposite end/s with regard to the shaft 22 or in proximity thereof.
As a further embodiment of the invention, an apparatus may be devised where in connection with the top of the tower, regardless of whether the tower is provided with a ceiling or a cover, or whether the tower is open at the top, there is arranged a feeding and washing device, which is either continuously or intermittently rotating. This device may preferably, but not necessarily, consist of, e.g., a vertical pipe located in the middle of the tower, the bottom of the pipe being sealed except for a few (e.g., three or four) feed pipes arranged at regular intervals to the circumference of the pipe, from which pipes pulp is discharged at a desired distance toward the side wall of the tower. Between the relevant feed pipes either directly in contact with a vertical pipe or arranged via a stem at a distance therefrom there is arranged a suitable nozzle apparatus, with which the space surrounding the feeding and washing apparatus of the tower is washed. This space refers either to the tower wall, the suspension device of the feeding and washing apparatus, the ceiling of the tower, or any other structure inside the tower, or some combination thereof. The relevant feeding and washing apparatus may be rotated continuously, and at a variable speed, whereby the device is essentially operated the same way as in the previous embodiment; i.e., the distance at which pulp is fed depends on the rotational speed of the feed device.
This embodiment also affords the possibility of keeping the feed device stationary for a while, which, of course, is also possible with the previously discussed embodiment shown in the FIGURE. The idea is now that the tower is filled a few sectors at a time, at the same time as the space surrounding the feed and washing device is washed from the area of the remaining sectors. Characteristic of both this and the prior embodiments of the invention is that the washing process need not be continuous, instead the washing may be pre-set to occur in a desired way, e.g. according to the degree of fouling of the tower.
A feed device feeding in several directions may, except for the previously described sealed-pipe, also be of the open scoop type, as shown in the FIGURE, in which there are several scoops, however. Thus, the washing devices are placed between the scoops, and the feeding of the washing liquid occurs in different directions relative to the directions in which the pulp is fed.
It should be further noted that the washing arrangement according to the invention may be suspended in a tower without any ceiling or cover. This means that both the pulp feeder arrangement and the washing apparatus for the tower walls are suspended either on the tower walls or on a special support structure arranged either in connection therewith or outside thereof.
As can be understood from the above a new method and apparatus for filling/cleaning pulp towers has been designed which corrects the numerous drawbacks of prior art apparatus and methods. However, only a few advantageous embodiments of the invention have been described above, which do not limit the scope of the invention from what has been defined in the appended patent claims. | The present invention relates to a method and apparatus for filling and cleaning a pulp tower. The invention is most suitable for filling and cleaning high-consistency pulp towers, bleaching towers, storage tanks and similar towers containing fiber suspensions, of the wood-processing industry. The apparatus and method according to the invention for filling and cleaning a pulp tower, in which method pulp is fed into the pulp tower either through its cover ( 10 ) or at least feed devices ( 24 ) arranged at its top, are characterized in that the space surrounding the feed device ( 24 ) is washable at the same time as the pulp is fed into the tower by means of washing devices ( 28, 30, 32 ) arranged in connection with the feed devices. | 3 |
BACKGROUND OF THE INVENTION
[0001] 2. Field of the Invention
[0002] This invention relates to novel fused pyrrolecarboxamides which selectively bind to GABAa receptors. This invention also relates to pharmaceutical compositions comprising such compounds. It further relates to the use of such compounds in treating anxiety, sleep and seizure disorders, and overdoses of benzodiazepine-type drugs, and enhancing alertness.
[0003] 2. Description of the Related Art
[0004] γ-Aminobutyric acid (GABA) is regarded as one of the major inhibitory amino acid transmitters in the mammalian brain. Over 30 years have elapsed since its presence in the brain was demonstrated (Roberts & Frankel, J. Biol. Chem 187: 55-63, 1950; Udenfriend, J. Biol. Chem. 187: 65-69, 1950). Since that time, an enormous amount of effort has been devoted to implicating GABA in the etiology of seizure disorders, sleep, anxiety and cognition (Tallman and Gallager, Ann. Rev. Neuroscience 8: 21-44, 1985). Widely, although unequally, distributed through the mammalian brain, GABA is said to be a transmitter at approximately 30% of the synapses in the brain. In most regions of the brain, GABA is associated with local inhibitory neurons and only in two regions is GABA associated with longer projections. GABA mediates many of its actions through a complex of proteins localized both on cell bodies and nerve endings; these are called GABAa receptors. Postsynaptic responses to GABA are mediated through alterations in chloride conductance that generally, although not invariably, lead to hyperpolarization of the cell. Recent investigations have indicated that the complex of proteins associated with postsynaptic GABA responses is a major site of action for a number of structurally unrelated compounds capable of modifying postsynaptic responses to GABA. Depending on the mode of interaction, these compounds are capable of producing a spectrum of activities (either sedative, anxiolytic, and anticonvulsant, or wakefulness, seizures, and anxiety).
[0005] 1,4-Benzodiazepines continue to be among the most widely used drugs in the world. Principal among the benzodiazepines marketed are chlordiazepoxide, diazepam, flurazepam, and triazolam. These compounds are widely used as anxiolytics, sedative-hypnotics, muscle relaxants, and anticonvulsants. A number of these compounds are extremely potent drugs; such potency indicates a site of action with a high affinity and specificity for individual receptors. Early electrophysiological studies indicated that a major action of benzodiazepines was enhancement of GABAergic inhibition. The benzodiazepines were capable of enhancing presynaptic inhibition of a monosynaptic ventral root reflex, a GABA-mediated event (Schmidt et al., 1967, Arch. Exp. Path. Pharmakol. 258: 69-82). All subsequent electrophysiological studies (reviewed in Tallman et al. 1980, Science 207: 274-81, Haefley et al., 1981, Handb. Exptl. Pharmacol. 33: 95-102) have generally confirmed this finding, and by the mid-1970s, there was a general consensus among electrophysiologists that the benzodiazepines could enhance the actions of GABA.
[0006] With the discovery of the “receptor” for the benzodiazepines and the subsequent definition of the nature of the interaction between GABA and the benzodiazepines, it appears that the behaviorally, important interactions of the benzodiazepines with different neurotransmitter systems are due in a large part to the enhanced ability of GABA itself to modify these systems. Each modified system, in turn, may be associated with the expression of a behavior.
[0007] Studies on the mechanistic nature of these interactions depended on the demonstration of a high-affinity benzodiazepine binding site (receptor). Such a receptor is present in the CNS of all vertebrates phylogenetically newer than the boney fishes (Squires & Braestrup 1977, Nature 166: 732-34, Mohler & Okada, 1977, Science 198: 854-51, Mohler & Okada, 1977, Br. J. Psychiatry 133: 261-68). By using tritiated diazepam, and a variety of other compounds, it has been demonstrated that these benzodiazepine binding sites fulfill many of the criteria of pharmacological receptors; binding to these sites in vitro is rapid, reversible, stereospecific, and saturable. More importantly, highly significant correlations have been shown between the ability of benzodiazepines to displace diazepam from its binding site and activity in a number of animal behavioral tests predictive of benzodiazepine potency (Braestrup & Squires 1978, Br. J. Psychiatry 133:249-60, Mohler & Okada, 1977, Science 198:854-51, Mohler & Okada, 1977, Br. J. Psychiatry 133:261-68). The average therapeutic doses of these drugs in man also correlate with receptor potency (Tallman et al. 1980, Science 207:274-281).
[0008] In 1978, it became clear that GABA and related analogs could interact at the low affinity (1 mM) GABA binding site to enhance the binding of benzodiazepines to the clonazepam-sensitive site (Tallman et al. 1978, Nature, 274:383-85). This enhancement was caused by an increase in the affinity of the benzodiazepine binding site due to occupancy of the GABA site. The data were interpreted to mean that both GABA and benzodiazepine sites were allosterically linked in the membrane as part of a complex of proteins. For a number of GABA analogs, the ability to enhance diazepam binding by 50% of maximum and the ability to inhibit the binding of GABA to brain membranes by 50% could be directly correlated. Enhancement of benzodiazepine binding by GABA agonists is blocked by the GABA receptor antagonist (+) bicuculline; the stereoisomer (−) bicuculline is much less active (Tallman et al., 1978, Nature, 274:383-85).
[0009] Soon after the discovery of high affinity binding sites for the benzodiazepines, it was discovered that a triazolopyridazine could interact with benzodiazepine receptors in a number of regions of the brain in a manner consistent with receptor heterogeneity or negative cooperativity. In these studies, Hill coefficients significantly less than one were observed in a number of brain regions, including cortex, hippocampus, and striatum. In cerebellum, triazolopyridazine interacted with benzodiazepine sites with a Hill coefficient of 1 (Squires et al., 1979, Pharma. Biochem. Behav. 10:825-30, Klepner et al. 1979, Pharmacol. Biochem. Behav. 11:457-62). Thus, multiple benzodiazepine receptors were predicted in the cortex, hippocampus, striatum, but not in the cerebellum.
[0010] Based on these studies, extensive receptor autoradiographic localization studies were carried out at a light microscopic level. Although receptor heterogeneity has been demonstrated (Young & Kuhar 1980, J. Pharmacol. Exp. Ther. 212:337-46, Young et al., 1981 J. Pharmacol Exp. ther 216:425-430, Niehoff et al. 1982, J. Pharmacol. Exp. Ther. 221:670-75), no simple correlation between localization of receptor subtypes and the behaviors associated with the region has emerged from the early studies. In addition, in the cerebellum, where one receptor was predicted from binding studies, autoradiography revealed heterogeneity of receptors (Niehoffet al., 1982, J. Pharmacol. Exp. Ther. 221:670-75).
[0011] A physical basis for the differences in drug specificity for the two apparent subtypes of benzodiazepine sites has been demonstrated by Sieghart & Karobath, 1980, Nature 286:285-87. Using gel electrophoresis in the presence of sodium dodecyl sulfate, the presence of several molecular weight receptors for the benzodiazepines has been reported. The receptors were identified by the covalent incorporation of radioactive flunitrazepam, a benzodiazepine which can covalently label all receptor types. The major labeled bands have molecular weights of 50,000 to 53,000, 55,000, and 57,000 and the triazolopyridazines inhibit labeling of the slightly higher molecular weight forms (53,000, 55,000, 57,000) (Seighart et al. 1983, Eur. J. Pharmacol. 88:291-99).
[0012] At that time, the possibility was raised that the multiple forms of the receptor represent “isoreceptors” or multiple allelic forms of the receptor (Tallman & Gallager 1985, Ann. Rev. Neurosci. 8, 21-44). Although common for enzymes, genetically distinct forms of receptors have not generally been described. As we begin to study receptors using specific radioactive probes and electrophoretic techniques, it is almost certain that isoreceptors will emerge as important in investigations of the etiology of psychiatric disorders in people.
[0013] The GABAa receptor subunits have been cloned from bovine and human cDNA libraries Schoenfield et al., 1988; Duman et al., 1989). A number of distinct cDNAs were identified as subunits of the GABAa receptor complex by cloning and expression. These are categorized into α, β, γ, δ, and provide a molecular basis for the GABAa receptor heterogeneity and distinctive regional pharmacology (Shiwers et al., 1980; Levitan et al., 1989). The γ subunit appears to enable drugs like benzodiazepines to modify the GABA responses (Pritchett et al., 1989). The presence of low Hill coefficients in the binding of ligands to the GABAa receptor indicates unique profiles of subtype specific pharmacological action.
[0014] Drugs that interact at the GABAa receptor can possess a spectrum of pharmacological activities depending on their abilities to modify the actions of GABA. For example, the beta-carbolines were first isolated based upon their ability to inhibit competitively the binding of diazepam to its binding site (Nielsen et al., 1979, Life Sci. 25:679-86). The receptor binding assay is not totally predictive about the biological activity of such compounds; agonists, partial agonists, inverse agonists, and antagonists can inhibit binding. When the beta-carboline structure was determined, it was possible to synthesize a number of analogs and test these compounds behaviorally. It was immediately realized that the beta-carbolines could antagonize the actions of diazepam behaviorally (Tenen & Hirsch, 1980, Nature 288:609-10). In addition to this antagonism, beta-carbolines possess intrinsic activity of their own opposite to that of the benzodiazepines; they become known as inverse agonists.
[0015] In addition, a number of other specific antagonists of the benzodiazepine receptor were developed based on their ability to inhibit the binding of benzodiazepines. The best studied of these compounds is an imidazodiazepine (Hunkeler et al., 1981, Nature 290:514-516). This compound is a high affinity competitive inhibitor of benzodiazepine and beta-carboline binding and is capable of blocking the pharmacological actions of both these classes of compounds. By itself, it possesses little intrinsic pharmacological activity in animals and humans (Hunkeler et al., 1981, Nature 290:514-16; Darragh et al., 1983, Eur. J. Clin. Pharmacol. 14:569-70). When a radiolabeled form of this compound was studied (Mohler & Richards, 1981, Nature 294:763-65), it was demonstrated that this compound would interact with the same number of sites as the benzodiazepines and beta-carbolines, and that the interactions of these compounds were purely competitive. This compound is the ligand of choice for binding to GABAa receptors because it does not possess receptor subtype specificity and measures each state of the receptor.
[0016] The study of the interactions of a wide variety of compounds similar to the above has led to the categorizing of these compounds. Presently, those compounds possessing activity similar to the benzodiazepines are called agonists. Compounds possessing activity opposite to benzodiazepines are called inverse agonists, and the compounds blocking both types of activity have been termed antagonists. This categorization has been developed to emphasize the fact that a wide variety of compounds can produce a spectrum of pharmacological effects, to indicate that compounds can interact at the same receptor to produce opposite effects, and to indicate that beta-carbolines and antagonists with intrinsic anxiogenic effects are not synonymous.
[0017] A biochemical test for the pharmacological and behavioral properties of compounds that interact with the benzodiazepine receptor continues to emphasize the interaction with the GABAergic system. In contrast to the benzodiazepines, which show an increase in their affinity due to GABA (Tallman et al., 1978, Nature 274:383-85, Tallman et al., 1980, Science 207:274-81), compounds with antagonist properties show little GABA shift (i.e., change in receptor affinity due to GABA) (Mohler & Richards 1981, Nature 294:763-65), and the inverse agonists actually show a decrease in affinity due to GABA (Braestrup & Nielson 1981, Nature 294:472-474). Thus, the GABA shift predicts generally the expected behavioral properties of the compounds.
[0018] Various compounds have been prepared as benzodiazepine agonists and antagonists. For Example, U.S. Pat. Nos. 3,455,943, 4,435,403, 4,596,808, 4,623,649, and 4,719,210, German Patent No. DE 3,246,932, and Liebigs Ann. Chem. 1986, 1749 teach assorted benzodiazepine agonists and antagonists and related anti-depressant and central nervous system active compounds.
[0019] U.S. Pat. No. 3,455,943 discloses compounds of the formula:
[0020] wherein R 1 is a member of the group consisting of hydrogen and lower alkoxy; R2 is a member of the group consisting of hydrogen and lower alkoxy; R 3 is a member of the group consisting of hydrogen and lower alkyl; and X is a divalent radical selected from the group consisting of
[0021] and the non-toxic acid addition salts thereof.
[0022] Other references, such as U.S. Pat. No. 4,435,403 and German patent DE 3,246,932 disclose compounds containing the following structural skeleton:
[0023] where A is carbon or nitrogen.
[0024] A variety of indole-3-carboxamides are described in the literature. For example, J. Org. Chem., 42:1883-1885 (1977) discloses the following compounds.
[0025] J. Heterocylic Chem. 14:519-520 (1977) discloses a compound of the following formula:
[0026] None of these indole-3-carboxamides includes an oxy substituent at the 4-position of the indole ring.
SUMMARY OF THE INVENTION
[0027] This invention provides novel compounds of Formula I which interact with a GABAa binding site, the benzodiazepine receptor.
[0028] The invention provides pharmaceutical compositions comprising compounds of Formula I. The invention also provides compounds useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory. Accordingly, a broad embodiment of the invention is directed to compounds of general Formula I:
[0029] or the pharmaceutically acceptable non-toxic salts thereof wherein:
[0030] G represents
[0031] where
[0032] Q is phenyl, 2- or 3-thienyl, or 2-, 3-, or 4-pyridyl, all of which may be mono or disubstituted with hydroxy or halogen;
[0033] T is halogen, hydrogen, hydroxyl, amino or alkoxy having 1-6 carbon atoms;
[0034] W is oxygen, nitrogen, sulfur, or CR 7 R 8 where R 7 and R 8 are the same or different and represent hydrogen, alkyl, or R 7 -R 8 taken together represents a cyclic moiety having 3-7 carbon atoms;
[0035] X is hydrogen, hydroxyl, or alkyl;
[0036] Z is
[0037] hydroxy, C 3 -C 7 cycloalkylC 1 -C 6 alkoxy, or C 1 -C 6 alkoxy where the alkyl portion is optionally substituted with amino, mono- or diC 1 -C 6 alkylamino, or azaC 1 -C 6 cycloalkyl;
[0038] amino, or mono- or diC 1 -C 6 alkylamino, (trifluoromethyl)methyl, C 3 -C 7 cycloalkyl optionally substituted with C 1 -C 6 alkyl, or C 3 -C 7 cycloalkylC 1 -C 6 alkyl;
[0039] phenyl or phenyl(C 1 -C 6 )alkyl where the phenyl portion is optionally substituted with C 1 -C 6 alkyl, hydroxy, C 1 -C 6 alkoxy, triflouromethyl, halogen, amino, or mono- or diC 1 -C 6 alkylamino;
[0040] 2-, 3-, or 4-pyridyl, 1- or 2-imidazolyl, 1-, 2-, or 3-pyrrolyl, or adamantane-2-yl; each of which may be substituted on a tertiary carbon or a secondary nitrogen with C 1 -C 6 alkyl;
[0041] NR 9 COR 10 where R 9 and R 10 are the same or different and represent hydrogen or C 1 -C 6 alkyl or C 3 -C 7 cycloalkyl; or
[0042] Z is connected, optionally through W, to Q to from a 1-6 membered ring; or
[0043] Z represents
[0044] a group of the formula:
[0045] where
[0046] p is 1, 2,or3;
[0047] D and D′ independently represent oxygen, NR y or CHR y provided that only one of D and D′ may be NR y where each R y is hydrogen or C 1 -C 6 alkyl; or and
[0048] R z is hydrogen or C 1 -C 6 alkyl;
[0049] a group of the formula;
[0050] where
[0051] p is 1, 2, or 3;
[0052] q is 0, 1, or 2;
[0053] R z is hydrogen or C 1 -C 6 alkyl; or
[0054] a group of the formula:
[0055] where
[0056] s is 0, 1, 2 or 3, and the sum of s and m is not less than 1;
[0057] R 0 is hydroxy, C 1 -C 6 alkoxy, amino, mono- or diC 1 -C 6 alkylamino where each alkyl is independently optionally substituted with amino, mono- or diC 1 -C 6 alkylamino, or
[0058] R 0 is a group of the formula
[0059] where p, D, D′, and R z are as defined above;
[0060] independently represent a carbon chain optionally substituted with hydrogen, halogen, or straight or branched chain lower alkyl having 1-6 carbon atoms;
[0061] wherein
[0062] k is 0, 1, 2, or 3;
[0063] m is 0, 1, 2, or 3; and
[0064] n is 0, 1, 2, or 3;
[0065] R 3 , R 4 , R 5 , and R 6 are the same or different and are selected from hydrogen, alkyl , —COR 11 or —CO 2 R 11 where R 11 is alkyl or cycloalkyl having 3-7 carbon atoms; or —CONR 12 R 13 where R 12 and R 13 are selected independently from hydrogen, alkyl, cycloalkyl having 3-7 carbon atoms, phenyl, 2-, 3-, or 4-pyridyl, or NR 12 R 13 forms a heterocyclic group which is morpholinyl, piperidinyl, pyrrolidinyl, or N-alkyl piperazinyl; or
[0066] R 3 -R 4 may be taken together to form a cyclic moiety having 3-7 carbon atoms; or
[0067] R 5 -R 6 may be taken together to form a cyclic moiety having 3-7 carbon atoms; and
[0068] where each alkyl group forming an R 3 , R 4 , R 5 , or R 6 substitutent or portion thereof may be substituted independently with hydroxy or mono- or dialkylamino where each alkyl is independently alkyl or cycloalkyl having 3-7 carbon atoms.
[0069] These compounds are highly selective agonists, antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptors. In other words, while the compounds of the invention all interact with GABAa brain receptors, they do not display identical physiologic activity. Thus, these compounds are useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory. For example, these compounds can be used to treat overdoses of benzodiazepine-type drugs as they would competitively bind to the benzodiazepine receptor.
DETAILED DESCRIPTION OF THE INVENTION
[0070] The novel compounds encompassed by the instant invention can be described by general formula I set forth above or the pharmaceutically acceptable non-toxic salts thereof.
[0071] In addition, the present invention encompasses compounds of Formula II.
[0072] wherein Y is hydrogen, halogen, or hydroxy; and W, Y, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0073] The present invention also encompasses compounds of Formula III
[0074] wherein Y is hydrogen, halogen, or hydroxy; and W, Y, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0075] The present invention also encompasses compounds of Formula IV, IVa, IVb, and IVc.
[0076] wherein Y is hydrogen, halogen, or hydroxy; and W, Y, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0077] The present invention also encompasses compounds of Formula V.
[0078] wherein Y is hydrogen, halogen, or hydroxy; and W, Y, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0079] The present invention also encompasses compounds of Formula VI.
[0080] wherein Y is hydrogen, halogen, or hydroxy; and W, Y, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0081] The present invention also encompasses compounds of Formula VII.
[0082] wherein W, Z, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0083] The present invention also encompasses compounds of Formula VIII.
[0084] wherein W, Z, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0085] The present invention also encompasses compounds of Formula IX.
[0086] wherein W, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0087] The present invention also encompasses compounds of Formula X.
[0088] wherein W, Z, k, m, n, R 3 , R 4 , R 5 , and R 6 are defined as above.
[0089] Preferred compounds of the invention are those where n is 1 or 2. Particularly preferred are those where X and T are both hydrogen. Thus, preferred compounds of the invention have formulas Ia and Ib.
[0090] Preferred G substituents of the invention include the following:
[0091] where R a represents hydrogen or alkyl where the alkyl is optionally halogenated; and e is an integer of 1-3.
[0092] More preferred G substituents of formula A include those where e is 1, 2, or 3, and R a is hydrogen, methyl, ethyl, isopropyl, or cyclopropyl. Particularly preferred G substituents of formula A include those where e is 1, 2, or 3, and R a is hydrogen or methyl.
[0093] Another preferred G substituent is the following formula:
[0094] where R a represents hydrogen or alkyl where the alkyl is optionally halogenated; and e is an integer of 1-3.
[0095] More preferred G substituents of formula B include those where e is 1, 2, or 3; and R a is hydrogen, methyl or ethyl. Particularly preferred G substituents of formula B include those where e is 1 or 2, and R a is hydrogen or methyl.
[0096] Another preferred G substituent is the following formula:
[0097] where
[0098] Hal represents a halogen, preferably fluoro, bromo, or chloro;
[0099] R a and R b independently represent hydrogen, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloalkylC 1 -C 6 alkyl where the cycloalkyl group may be substituted with halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, or mono- or diC 1 -C 6 alkylamino; and
[0100] e is an integer of 2-3.
[0101] Preferred compounds having formula C as the G group include those where Hal is fluoro and e is 2, 3, or 4.
[0102] More preferred G substituents of formula C include those where R a is hydrogen, methyl or ethyl; and R b is hydrogen. Particularly preferred G substituents of formula C include those where e is 2; R a is hydrogen or methyl; and R b is hydrogen.
[0103] Another preferred G substituent is the following formula:
[0104] where
[0105] Hal represents a halogen, preferably fluoro, bromo, or chloro;
[0106] R a and R b independently represent hydrogen, C 1 -C 6 alkyl C 3 -C 7 cycloalkyl, C 3 -C 7 cycloalkylC 1 -C 6 alkyl where the cycloalkyl group may be substituted with halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, or mono- or diC,-C 6 alkylamino; and
[0107] e is an integer of 2-3.
[0108] Preferred compounds having formula C-1 as the G group include those where Hal is fluoro and e is 2, 3, or 4.
[0109] Another preferred G substituent is the following formula:
[0110] where R a represents hydrogen, alkyl, or C 3-7 cycloalkyl, or a group of the formula:
[0111] where
[0112] p is 1, 2, or 3;
[0113] D and D′ independently represent oxygen, NR y or CHR y , provided that only one of D and D′ may be NR y , where each R y is hydrogen or C 1 -C 6 alkyl; and
[0114] R z is hydrogen or C 1 -C 6 alkyl; and
[0115] R b represents hydrogen, alkyl, or acyl;
[0116] Y and Y′ independently represent hydrogen or halogen; and
[0117] e is an integer of 1-3.
[0118] More preferred G substituents of formula D are those where Y is hydrogen or fluorine; and e is 1 or 2. Particularly preferred G substituents of formula D are those where Y is hydrogen or fluorine; e is 1 or 2; R a is hydrogen, C 1 -3 alkyl, or cyclopropyl, and R b is hydrogen, methyl, or acyl. Other particularly preferred G substituents of formula D are those where Y is hydrogen and Y′ is fluorine. Still other particularly preferred G groups of Formula D are those where e is 1 or 2; R a is hydrogen, C 1 -3 alkyl, cyclopropyl or cyclopropylmethyl, and R b is hydrogen, methyl, or acyl.
[0119] Another preferred G substituent is the following formula:
[0120] where R a represents hydrogen, alkyl, or C 3-7 cycloalkyl; and
[0121] R b represents hydrogen, alkyl, or acyl; or
[0122] R a and R b independently represent hydrogen, C 1 -C 6 alkyl, C 3-7 cycloalkylC 1 -C 6 alkyl; and
[0123] Y and Y′ independently represent hydrogen or halogen; and
[0124] e is an integer of 1-3.
[0125] More preferred G substituents of formula D are those where Y is hydrogen or fluorine; and e is 1 or 2. Particularly preferred G substituents of formula D are those where Y is hydrogen or fluorine; e is 1 or 2; R a is hydrogen, C 1-3 alkyl, or cyclopropyl, and R b is hydrogen, methyl, or acyl. Other particularly preferred G substituents of formula D are those where Y is hydrogen and Y′ is fluorine. Still other particularly preferred G groups of Formula D are those where e is 1 or 2; R a is hydrogen, C 1-3 alkyl, cyclopropyl or cyclopropylmethyl, and R b is hydrogen, methyl, or acyl.
[0126] Another preferred G substituent is the following formula:
[0127] where Z is oxygen, nitrogen, or methylene; and m is 1 or 2.
[0128] Particularly preferred G substituents of formula E are those where Z is oxygen, and m is 1 or 2. Other particularly preferred G substituents of formula E are those where Z is nitrogen, and m is 1 or 2.
[0129] Another preferred G substituent is the following formula:
[0130] where Z is oxygen or nitrogen; and m is 1 or 2.
[0131] Particularly preferred G substituents of formula F are those where Z is nitrogen, and m is 1 or 2.
[0132] Another preferred G substituent is the following formula:
[0133] where Z is oxygen, nitrogen, or methylene; and m is 1 or 2.
[0134] Particularly preferred G substituents of formula H are those where Z is nitrogen, and m is 1 or 2.
[0135] Another preferred G substituent is the following formula:
[0136] where R a represents hydrogen, alkyl, or C 3-7 cycloalkyl;
[0137] R b represents hydrogen, alkyl, or acyl;
[0138] Y and Y′ independently represent hydrogen or halogen; and
[0139] e is an integer of 1-3.
[0140] More preferred G substituents of formula J are those where Y and Y′ are independently hydrogen or fluorine; and e is 1 or 2. Particularly preferred G substituents of formula J are those where and Y′ are independently hydrogen or fluorine; e is 1 or 2; R a is hydrogen, C 1-3 alkyl, or cyclopropyl, and R b is hydrogen, methyl, or acyl.
[0141] Another preferred G substituent is the following formula:
[0142] where
[0143] R a and R b independently represent hydrogen, C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl, C 3 -C 7 cycloalkylC 1 -C 6 alkyl where the cycloalkyl group may be substituted with halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, or mono- or diC 1 -C 6 alkylamino; and
[0144] e is an integer of 2-3.
[0145] Another preferred G substituent is represented by the following formula:
[0146] where
[0147] R h is hydrogen, halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, or trifluoromethyl;
[0148] s is 0, 1, 2 or 3, and the sum of s and m is not less than 1;
[0149] R 0 is hydroxy, C 1 -C 6 alkoxy, amino, mono- or diC 1 -C 6 alkylamino where each alkyl is independently optionally substituted with amino, mono- or diC 1 -C 6 alkylamino, or
[0150] R 0 is a group ofthe formula
[0151] p is 1, 2, or 3;
[0152] D and D′ independently represent oxygen, NR y or CHR y provided that only one of D and D′ may be NR y where each R y is hydrogen or C 1 -C 6 alkyl; or and
[0153] R z is hydrogen or C 1 -C 6 alkyl.
[0154] Preferred M groups are those where R h is hydrogen or halogen, most preferably fluoro, and R 0 is a group of the formula:
[0155] where
[0156] R 14 is hydrogen or C 1 -C 6 alkyl;
[0157] R 5 is hydrogen or C 1 -C 6 alkyl;
[0158] R 16 is hydrogen, ethyl, or methyl;
[0159] R 17 is C 1 -C 6 alkyl; and
[0160] J is a C 1 -C 4 alkylene group, preferably methylene, ethylene, or propylene.
[0161] Particularly preferred groups of Formula M include those where s is 1 and R 0 is ethoxy, hydroxy, ethylamino, diethylamino, morpholinyl, piperazinyl, 4-methylpiperazinyl,
[0162] Representative compounds of the invention are shown below in Table 1.
TABLE 1 Compound 1 Compound 2 Compound 3 Compound 4 Compound 5 Compound 6 Compound 7 Compound 8 Compound 9 Compound 10 Compound 11 Compound 12 Compound 13 Compound 14 Compound 15 Compound 47 Compound 86 Compound 95 Compound 115 Compound 145 Compound 148 Compound 149 Compound 179 Compound 222 Compound 226 Compound 227 Compound 229 Compound 235
[0163] The following numbering conventions are used to identify positions on the ring systems in the compounds of the invention:
[0164] Representative compounds of the present invention, which are encompassed by Formula I, include, but are not limited to the compounds in Table I and their pharmaceutically acceptable salts. Non-toxic pharmaceutically acceptable salts include salts of acids such as hydrochloric, phosphoric, hydrobromic, sulfuric, sulfinic, formic, toluenesulfonic, methanesulfonic, nitric, benzoic, citric, tartaric, maleic, hydroiodic, alkanoic such as acetic, HOOC—(CH 2 ) n —COOH where n is 0-4, and the like. Those skilled in the art will recognize a wide variety of non-toxic pharmaceutically acceptable addition salts.
[0165] Representative compounds of the present invention, which are encompassed by Formula I, include, but are not limited to the compounds in Table 1 and their pharmaceutically acceptable salts. The present invention also encompasses the acylated prodrugs of the compounds of Formula I. Those skilled in the art will recognize various synthetic methodologies which may be employed to prepare non-toxic pharmaceutically acceptable addition salts and acylated prodrugs of the compounds encompassed by Formula I.
[0166] By “alkyl” or “lower alkyl” in the present invention is meant straight or branched chain alkyl groups having 1-6 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl, and 3-methylpentyl.
[0167] By “alkoxy” or “lower alkoxy” in the present invention is meant straight or branched chain alkoxy groups having 1-6 carbon atoms, such as, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentoxy, 2-pentyl, isopentoxy, neopentoxy, hexoxy, 2-hexoxy, 3-hexoxy, and 3-methylpentoxy.
[0168] By “diC 1 -C 6 alkylamnino” is meant an amino group carrying two C 1 -C 6 alkyl groups that are the same or different.
[0169] By “benzoxazinyl” as used herein is meant a moiety of the formula:
[0170] A benzoxazin-6-yl group is depicted.
[0171] By “halogen” in the present invention is meant fluorine, bromine, chlorine, and iodine.
[0172] By “2-hydroxyethoxy” is meant a group of the formula: —OCH 2 CH 2 OH.
[0173] By a 2-, 3-, or 4-pyridyl, 1- or 2-imidazolyl, 1-, 2-, or 3-pyrrolyl, or adamantane-2-yl group that is substituted on a tertiary carbon or a secondary nitrogen with C 1 -C 6 alkyl is meant any such group in which a hydrogen atom is replaced with an appropriate alkyl group. By way of example, such groups include the following:
[0174] By “N-alkylpiperazyl” in the invention is meant radicals of the formula:
[0175] where R is a straight or branched chain lower alkyl as defined above.
[0176] The pharmaceutical utility of compounds of this invention are indicated by the following assay for GABAa receptor binding activity.
[0177] Assays are carried out as described in Thomas and Tallman (J. Bio. Chem. 156:9838-9842 , J. Neurosci. 3:433-440, 1983). Rat cortical tissue is dissected and homogenized in 25 volumes (w/v) of 0.05 M Tris HCl buffer (pH 7.4 at 4° C.). The tissue homogenate is centrifuged in the cold (4°) at 20,000×g for 20′. The supernatant is decanted and the pellet is rehomogenized in the same volume of buffer and again centrifuged at 20,000×g. The supernatant is decanted and the pellet is frozen at −20° C. overnight. The pellet is then thawed and rehomogenized in 25 volume (original wt/vol) of buffer and the procedure is carried out twice. The pellet is finally resuspended in 50 volumes (w/vol of 0.05 M Tris HCl buffer (pH 7.4 at 40° C.).
[0178] Incubations contain 100 ml of tissue homogenate, 100 ml of radioligand 0.5 nM ( 3 H-RO15-1788 [ 3 H-Flumazenil] specific activity 80 Ci/mmol), drug or blocker and buffer to a total volume of 500 ml. Incubations are carried for 30 min at 4° C. then are rapidly filtered through GFB filters to separate free and bound ligand. Filters are washed twice with fresh 0.05 M Tris HCl buffer (pH 7.4 at 4° C.) and counted in a liquid scintillation counter. 1.0 mM diazepam is added to some tubes to determine nonspecific binding. Data are collected in triplicate determinations, averaged and % inhibition of total specific binding is calculated. Total Specific Binding=Total−Nonspecific. In some cases, the amounts of unlabeled drugs is varied and total displacement curves of binding are carried out. Data are converted to Ki's; results for compounds of this invention are listed in Table 2.
TABLE 2 Compound Number K i (nM) 1 90 2 29 3 49 4 0.24 5 9 6 9 7 30 8 27 9 1.3 10 37 11 7 12 5 13 24 14 3 15 12
[0179] The compounds of general formula I may be administered orally, topically, parenterally, by inhalation or spray or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition, there is provided a pharmaceutical formulation comprising a compound of general formula I and a pharmaceutically acceptable carrier. One or more compounds of general formula I may be present in association with one or more non-toxic pharmaceutically acceptable carriers and/or diluents and/or adjuvants and if desired other active ingredients. The pharmaceutical compositions containing compounds of general formula I may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs.
[0180] Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monosterate or glyceryl distearate may be employed.
[0181] Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin or olive oil.
[0182] Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example, lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.
[0183] Oily suspensions may be formulated by suspending the active ingredients in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide palatable oral preparations. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.
[0184] Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.
[0185] Pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol, anhydrides, for example sorbitan monoleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monoleate. The emulsions may also contain sweetening and flavoring agents.
[0186] Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitor or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be sterile injectable solution or suspension in a non-toxic parentally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are 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. In addition, fatty acids such as oleic acid find use in the preparation of injectables.
[0187] The compounds of general formula I may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials are cocoa butter and polyethylene glycols.
[0188] Compounds of general formula I may be administered parenterally in a sterile medium. The drug, depending on the vehicle and concentration used, can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as local anaesthetics, preservatives and buffering agents can be dissolved in the vehicle.
[0189] Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment of the above-indicated conditions (about 0.5 mg to about 7 g per patient per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Dosage unit forms will generally contain between from about 1 mg to about 500 mg of an active ingredient.
[0190] It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
[0191] An illustration of the preparation of compounds of the present invention is given in Scheme I.
[0192] where:
[0193] Ar is
[0194] where Q, W, k, m, n, Z, R 3 , R 4 , R 5 , and R 6 are as defined above.
[0195] Those having skill in the art will recognize that the starting materials may be varied and additional steps employed to produce compounds encompassed by the present invention, as demonstrated by the following examples.
[0196] In some cases protection of certain reactive functionalities may be necessary to achieve some of the above transformations. In general the need for such protecting groups will be apparent to those skilled in the art of organic synthesis as well as the conditions necessary to attach and remove such groups. Representative examples of the preparation of various protected aniline derivatives are shown in Schemes II (1), (2) and (3).
[0197] Compounds of Formula I where G is a group of, for example, formulas C, C-1, D, D-1, K or M can be made using the above outlined methods and, e.g., additional ester and amide coupling reactions. In certain situations, protection of the indole ring nitrogen will be necessary.
[0198] For example, compounds where R 0 is a dialkylamino group can be prepared from a 2-(4-nitrophenoxy)ethan-1-ol made as described above and oxidation of the hydroxy group, and subsequent formation of an acid chloride or active ester. The active ester or acid chloride may then be coupled to an appropriate amine and the resulting nitrophenyl compound used as shown in the above schemes.
[0199] The disclosures in this application of all articles and references, including patents, are incorporated herein by reference in their entirety.
[0200] One skilled in the art will recognize that modifications may be made in the present invention without deviating from the spirit or scope of the invention. The invention is illustrated further by the following examples which are not to be construed as limiting the invention or scope of the specific procedures or compositions described herein.
EXAMPLE 1
[0201] Preparation of starting materials and intermediates
[0202] The starting materials and various intermediates may be obtained from commercial sources, prepared from commercially available organic compounds, or prepared using well known synthetic methods.
[0203] Representative examples of methods for preparing intermediates of the invention are set forth below.
[0204] 1. 4-oxo-4,5,6,7-etrahydrobenzofuran-3-carboxylic acid
[0205] 4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid is prepared according to the following procedure. Potassium hydroxide (345 g, 6.15 mol) is dissolved in methyl alcohol (1.2 L) then cooled in an ice water bath. A solution of cyclohexanedione (714 g, 6.15 mol) in methyl alcohol (1.2 L), dissolved using gentle heat, is added dropwise to the cold, stirred KOH solution over 2 h. A solution of ethyl bromopyruvate (1200 g, 6.15 mol) in methyl alcohol (1.5 L) is then added dropwise over 3 h. The reaction mixture is allowed to reach ambient temperature and stirred an additional 14.5 h. While cooling the reaction mixture via a water bath, a solution of sodium hydroxide (492 g, 12.4 mol) in water (984 mL) is added dropwise over 2.5 h. After stirring at ambient temperature for 15.5 h, the reaction mixture is cooled in an ice water bath, 500 g of ice added, and the resulting mixture is then acidified with concentrated hydrochloric acid (ca 1 L) to pH 1. The reaction mixture is concentrated in vacuo, 1 L of ice is added, and the precipitate filtered, washed with ice water (3×200 mL), and then dried in a vacuum oven at 75° C. to afford 4-oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid (560 g). m.p. 137-138° C.
[0206] 2. 4-oxo-4,5,6,7-tetrah droindole-3-carboxylate
[0207] To a stirred mixture of 4-oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid (640 g, 3.55 mol), potassium carbonate (1.7 kg, 10.65 mol) and cesium carbonate (100 g, 0.32 mol) in N,N-dimethylformamide (9.0 L) is added iodoethane (1250 g, 8.01 mol). The mixture is heated at 60° C. for 2 h. After cooling to ambient temperature, the mixture is filtered, the solid is rinsed with ethyl acetate, and the filtrate concentrated in vacuo. Water (2 L) is added then extracted with ethyl acetate (2×2 L); the combined organic extracts are washed with brine, dried over magnesium sulfate, filtered, and concentrated in vacuo to give ethyl 4-oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid (642 g). A mixture of this ester (640 g, 3.07 mol) and ammonium acetate (426 g, 5.53 mol) in N,N-dimethylformamide (320 mL) is heated to 100° C. for 2 h. The reaction mixture is concentrated in vacuo , ice water (2.5 L) is added, and extracted with dichloromethane (2×3 L); the combined organic extracts are washed with brine, dried over magnesium sulfate, filtered, and concentrated in vacuo to give ethyl 4-oxo-4,5,6,7-tetrahydroindole-3-carboxylate (357 g). A mixture of this ester (170 g, 0.82 mol) in ethyl alcohol (250 mL) and a solution of sodium hydroxide (165 g, 4.1 mol) in water (1 L) is heated at reflux for 1 h, then cooled in an ice water bath. Concentrated hydrochloric acid (350 mL) is added dropwise, the precipitate collected by filtration, rinsed with ice water (3 X), and dried in a vacuum oven at 75° C. to afford 4-oxo-4,5,6,7-tetrahydroindole-3-carboxylate (125 g). m.p. 269-270° C.
[0208] 3. 4-[N-trifluoroacetyl-(methvlaminomethyl)aniline
[0209] A solution of p-nitrobenzylbromide (5.40 g, 25 mmol) in acetonitrile (60 ml) is added dropwise to a stirred solution of aqueous methylamine (65 mL, 40 wt. %, 0.75 mol) in acetonitrile (50 mL) at 0°. After stirring an additional 15 minutes, the solution is poured into brine and extracted 2X with dichloromethane. The combined organic layers are washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 4-(methylaminomethyl)nitrobenzene (4.04 g).
[0210] A solution of trifluoracetic anhydride (4.46 mL, 31.6 mmol) in dichloromethane (10 mL) is added dropwise to a stirred solution of 4-(methylaminomethyl)nitrobenzene (4.04 g, 24.3 mmol) and pyridine (2.16 mL, 26.7 mmol) in dichloromethane (25 mL) at 0°. After stirring an additional 30 minutes, the solution is poured into aqueous 3.6N hydrochloric acid and extracted with dichloromethane. The organic layer is washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 4-[N-trifluoroacetyl-(methylaminomethyl)]nitrobenzene (6.55 g).
[0211] Crude 4-[N-trifluoroacetyl-(methylaminomethyl)]nitrobenzene (6.55 g) is dissolved in ethyl alcohol (75 mL), added to 10% Pd/C (655 mg) in a Parr bottle and shaken under Hydrogen (50 PSI) for 4 hours. The mixture is filtered through Celite and concentrated in vacuo to give 4-[N-trifluoroacetyl-(methylaminomethyl)aniline (5.75 g).
[0212] The 3-aminoalkylanilines are prepared in a similar fashion according to the procedure generally set forth in part (1) of Scheme II above.
[0213] 4. 4-amino-(N-trifluoroacetyl-2-methylaminoethoxy)benzene
[0214] A mixture of p-nitrophenol (1.39 g, 10 mmol), 2-chloroethoxytrimethylsilane (3.2 ml, 20 mmol), potassium carbonate (4.15 g, 30 mmol), cesium carbonate (163 mg, 0.5 mmol), and sodium iodide (149 mg, 1 mmol) in N,N-dimethylformamide ( 10 ml) is heated at 75° for 19.5 hours. After cooling to ambient temperature, the mixture is diluted with ethyl acetate and filtered. The filtrate is washed with saturated aqueous sodium bicarbonate, then washed 2X with water, dried over magnesium sulfate, filtered, concentrated in vacuo, and purified on Silica gel (1:1 ethyl acetate/hexanes) to give 4-nitro-(2-Hydroxyethoxy)benzene (1.25 g).
[0215] 4-Nitro-(2-Hydroxyethoxy)benzene (1.13 g, 6.2 mmol) in thionyl chloride (10 mL) is heated at reflux for 3 hours then concentrated in vacuo . After cooling the residue in an ice water bath, saturated aqueous sodium bicarbonate is added and the precipitate collected, rinsed with water, and dried to give 4-nitro-(2-chloroethoxy)benzene (909 mg).
[0216] A mixture of 4-nitro-(2-chloroethoxy)benzene (781 mg, 3.9 mmol) and aqueous methylamine (15 mL, 40 wt. %) in isopropyl alcohol (15 mL) is heated in a sealed tube at 100° for 4 hours. After cooling in an ice water bath, the mixtured is poured into brine and extracted 2X with dichloromethane, dried over sodium sulfate, filtered, and concentrated in vacuo to give 4-nitro-(2-methylaminoethoxy)benzene (697 mg).
[0217] To a solution of 4-nitro-(2-methylaminoethoxy)benzene (766 mg, 3.9 mmol) and pyridine (0.35 mL, 4.29 mmol) in dichloromethane (5 mL) at 0° C. is added dropwise trifluroacetic anhydride (0.72 mL, 5.08 mmol). After stirring at 0° C. for 3.5 hours, the mixture is poured into aqueous 1.2 N hydrochloric acid and extracted with dichloromethane. The organic layer is washed with saturated aqueous sodium bicarbonate then brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 4-nitro-(N-trifluoroacetyl-2-methylaminoethoxy)benzene (1.06 g). Treatment of this nitro compound with 10% Palladium on carbon in ethyl alcohol (18 mL) in a Parr bottle under Hydrogen (55 PSI) for 2.25 hours affords 4 -amino-(N-trifluoroacetyl-2-methylaminoethoxy)benzene (709 mg).
EXAMPLE 2
[0218] [0218]
[0219] To a stirred solution of 4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxylic acid (100 mg, 0.6 mmol) and triethylamine (0.15 mL, 1.1 mmol) in N,N-dimethylformamide (5 mL) at 0° C. is added ethyl chloroformate (0.1 mL, 1.1 mmol). After stirring an additional 1 hour, 3-(N-trifluoroacetyl-(methylaminomethyl)aniline (0.3 g, 1.3 mmol) is added. The reaction mixture is stirrred for 4 hours, then poured into saturated aqueous ammonium chloride and extracted 2X with ethyl acetate. The combined organic layers are washed sequentially with brine, aqueous 2N hydrochloric acid, then brine, dried over sodium sulfate, filtered, and concentrated in vacuo. To the residue is added 15% aqueous potassium bicarbonate (5 mL) and methyl alcohol (3 mL), then heated at reflux for 3 hours. After cooling, the reaction mixture is extracted with ethyl acetate, the organic layer dried over sodium sulfate, filtered, and concentrated in vacuo to give N-[3-(methylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide; (Compound 1) m.p. 130-132° C.
EXAMPLE 3
[0220] The following compounds are prepared essentially according to the procedures described in Examples 1-5:
[0221] (a) N-[3-(Methylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 1); mp 130-132° C.
[0222] (b) N-[4-(Hydroxyethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 16); mp 245-247° C.
[0223] (c) N-[4-(Methoxyethoxy)phenyl]-4-oxo- 4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 2).
[0224] (d) N-[-4-(3-Methylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 17); mp 233-236° C.
[0225] (e) N-[4-(Methoxymethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 18); mp 164-165° C.
[0226] (f) N-[4-(Aminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 6); mp >200° C. (d).
[0227] (g) N-[4-(Methylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 19); mp 217-219° C.
[0228] (h) N-[2-Fluoro-4-(methylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 3); mp 186-188° C.
[0229] (i) N-{4-[N-acetyl-(methylaminomethyl)phenyl])}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 20); mp 204-206° C.
[0230] (j) N-[4-(Ethylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 21); mp 194-195° C.
[0231] (k) N-[4-(Isopropylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 22); mp 164-166° C.
[0232] (l) N-[4-(Cyclopropylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 5); mp 171-173° C.
[0233] (m) N-[4-(Dimethylaminomethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 23); mp 216-218° C.
[0234] (n) N-[4-(2-Aminoethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-ndole-3-carboxamide (Compound 24); mp 85-90° C.
[0235] (o) N-[4-(2-Methylaminoethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 4); mp 197-200° C.
[0236] (p) N-[4-(Methoxymethyl)phenyl]-4-oxo-5,5-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 25).
[0237] (q) N-[4-(Methylaminomethyl)phenyl-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 7); mp 173-175° C.
[0238] (r) N-{4-[N-acetyl-(methylaminomethyl)phenyl]}-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 26); mp 159-161° C.
[0239] (s) N-[4-(Methylaminomethyl)phenyl]-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 27); mp 217-219° C.
[0240] (t) N-[4-(Hydroxymethyl)phenyl]-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 28); mp 260-262° C.
[0241] (u) N-[4-(2-Hydroxyethoxy)phenyl]-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 9); mp 245-247° C.
[0242] (v) N-[3-(Methylaminomethyl)phenyl]-4-oxo-6-methyl-4,5,6,7-tetraydro-1H-indole-3-carboxamide (Compound 29); mp 172 -174° C.
[0243] (w) N-[4-(2-Hydroxyethoxy)phenyl]-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 30); mp 268-270° C.
[0244] (x) N-[3-(Hydroxymethyl)phenyl]-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 8); mp 233-235° C.
[0245] (y) N-[4-(Hydroxymethyl)phenyl]-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 31); mp 245-247° C.
[0246] (z) N-[4-(Methylaminomethyl)phenyl]-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 32); mp 230-232° C.
[0247] (aa) N-(1,3-Benzodioxol-5-yl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 10); mp 248-249° C.
[0248] (bb) N-(2,3-Dihydro-1,4-benzodioxin-6-yl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 11); mp 254-256° C.
[0249] (cc) N-(3,4-Dihydro-2H-1,4-benzoxazin-6-yl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 33); mp 216° C.
[0250] (dd) N-(2,2-Dimethyl-1,3-benzodioxol-5-yl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 34).
[0251] (ee) N-(2,3-Dihydro-1H-indol-5-yl)4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 35); mp 283-286° C.
[0252] (ff) N-(2,3-Dihydro-1H-indol-6-yl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 13); mp 322-323° C.
[0253] (gg) N-(1,3-Benzodioxol-5-yl)-4-oxo-5,5-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 36).
[0254] (hh) N-(2,3-Dihydro-1,4-benzodioxin-6-yl)-4-oxo-5,5-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 37); mp 241-243° C.
[0255] (ii) N-(4H-1,3-Benzodioxin-7-yl)-4-oxo-5,5-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 38); mp 251-252° C.
[0256] (jj) N-(1,3-Benzodioxol-5-yl)-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 39); mp 210-212° C.
[0257] (kk) N-(2,3-Dihydro-1,4-benzodioxin-6-yl)-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 12); mp 222-223° C.
[0258] (ll) N-(2,2-Dimethyl-1,3-benzodioxol-5-yl)-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 40); mp 155-157° C.
[0259] (mm) N-(1,3-Benzodioxol-5-yl)-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 41); mp 297-299° C.
[0260] (nn) N-(2,3-Dihydro-1,4-benzodioxin-6-yl)-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 42); mp 290-292° C.
[0261] (oo) N-(1,3-Benzodioxol-5-yl)-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 43); mp 245-246° C.
[0262] (pp) N-(2,3-Dihydro-1,4-benzodioxin-6-yl)-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 44).
[0263] (qq) N-(4H-1,3-Benzodioxin-7-yl)-4-oxo-6,6-dimethyl-4,5,6,7-etrahydro-1H-indole-3-carboxamide (Compound 45); mp 234-236° C.
[0264] (rr) N-[(2-Hydroxyethoxy)pyrid-5-yl]-4-oxo-6-methyl-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 15); mp 221-223° C.
[0265] (ss) N-(3,4-Dihydro-2H-1,4-benzoxazin-7-yl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 46).
[0266] (tt) N-[3-(2-Pyrrolidinylethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide; [alternate name: (4-oxo(5,6,7-trihydroindol-3-yl))-N-[4-(2-pyrrolidinylethoxy)phenyl]carboxamide] (Compound 47);
[0267] (uu) N-[3-(2-Dimethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide [alternate name: (4-oxo(5,6,7-trihydroindol-3-yl))-N-[4-(2-Dimethylaminoethoxy)phenyl]carboxamide] (Compound 48);
[0268] (vv) N-[3-(2-n-Propylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 49).
[0269] (ww) N-[3-(2-n-Butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 50).
[0270] (xx) N-[3-(2-Isobutylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 51) (syrup).
[0271] (yy) N-[3-(2-Cyclobutylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxarnide (Compound 52).
[0272] (zz) N-[3-(2-t-Butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 53).
[0273] (aaa) N-[3-(2-Cyclopropylmethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 54).
[0274] (bbb) N-{3-[2-(4-Methylcyclohexyl)aminoethoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 55).
[0275] (ccc) N-{3-[2-(3-Trifluoromethylbenzylamino)ethoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 56).
[0276] (ddd) N- {3-[3-(3-Trifluoromethylbenzylamino)propoxy]phenyl}-4-oxo-4,5 ,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 57).
[0277] (eee) N-[4-(2-Dimethylaminoethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 58).
[0278] (fff) N-[4-(2-Pyrrolidin-1-ylethyl)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 59); mp 184-186° C.
[0279] (ggg) N-[4-(2-Diisopropylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 60).
[0280] (hhh) N-[4-(2-Methylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 61).
[0281] (iii) N-[4-(2-Ethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 62); mp 140-141° C.
[0282] (jjj) N-[2-Fluoro-4-(2-ethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 63).
[0283] (kkk) N-[4-(2-n-Propylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 64); mp 130-133° C.
[0284] (lll) N-[2-Fluoro-4-(2-n-propylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 65).
[0285] (mmm) N-[3-Fluoro-4-(2-n-propylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 66).
[0286] (mmm-a) N-[3-Fluoro-4-(2-n-propylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 67); mp 373° C.
[0287] (nnn) N-[4-(2-Cyclopropylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 68).
[0288] (ooo) N-[4-(2-Isopropylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 69); mp 284-286° C.
[0289] (ppp) N-[4-(2-Cyclopropylmethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 70).
[0290] (ppp-a) N-[4-(2-Cyclopropylmethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hemifumarate (Compound 71); mp234-234° C.
[0291] (qqq) N-[2-Fluoro-4-(2-Cyclopropylmethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 72); mp 247-250° C.
[0292] (rrr) N-[3-Fluoro-4-(2-Cyclopropylmethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 73).
[0293] (rrr-a) N-[3-Fluoro-4-(2-Cyclopropylmethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide tosylate (Compound 74); mp 222° C.
[0294] (sss) N-[4-(2-Isobutylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 75); dust.
[0295] (ttt) N-[2-Fluoro-4-(2-Isobutylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 76); mp 152-155° C.
[0296] (uuu) N-[3-Fluoro-4-(2-Isobutylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 77); mp 147-149° C.
[0297] (vvv) N-[4-(2-n-Butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 78).
[0298] (vvv-a) N-[4-(2-n-Butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 79); mp 187-190° C.
[0299] (www) N-[3-Fluoro-4-(2-n-butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 80).
[0300] (xxx) N-[4-(2-t-Butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 81); mp 290-292° C.
[0301] (yyy) N-[3-Fluoro-4-(2-t-butylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 82).
[0302] (aaaa) N-[4-(2-adamant-2-ylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 83); mp 144-149° C.
[0303] (bbbb) N-{4-[(R)-Pyrrolidin-2-ylmethoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 84); mp 164-167-170° C.
[0304] (cccc) N-{4-[(S)-Pyrrolidin-2-ylmethoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 85); mp 165-167° C.
[0305] (dddd) N-[4-(Piperidin-3-ylmethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 86).
[0306] (dddd-a) N-[4-(Piperidin-3-ylmethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 87); mp 196-199° C.
[0307] (eeee) N-[4-(2-Dimethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 88); mp 201° C.
[0308] (ffff) N-[3-Fluoro-4-(2-dimethylaminoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 89); mp 203° C.
[0309] (gggg) N-[4-(2-Pyrrolidin-1-ylethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 90); mp 164-168° C.
[0310] (hhhh) N-[4-(2-Imidaz-1-ylethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 91); mp 226-230° C.
[0311] (iiii) N-[3-Fluoro-4-(2-moropholin-1-ylethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 92); mp 200° C.
[0312] (jjjj) N-[3-Fluoro-4-(2-pyrrolidin-1-ylethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 93).
[0313] (kkkk) N-[4-(2-Piperidin-2-ylethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 94); mp 281-285° C.
[0314] (llll) N-{4-[3-(2,2,2,-Trifluoroethyl)aminopropoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 95).
[0315] (mmmm) N-[4-(3-Isopropylaminopropoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 96).
[0316] (nnnn) N-{4-[3-(2-Methylpropyl)aminopropoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 97).
[0317] (oooo) N-[4-(3-Isobutylaminopropoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 98).
[0318] (pppp) N-[4-(3-Cyclopropylmethylaminopropoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 99).
[0319] (qqqq) N-{4-[3-(3-Ethylpropyl)aminopropoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 100).
[0320] (rrrr) N-[4-(3-Cyclopentylaminopropoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 101).
[0321] (ssss) N- {4-[3-(N-Cyclopropylmethyl,N-propyl)aminopropoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 102).
[0322] (tttt) N-[4-(2-Methylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 103).
[0323] (uuuu) N-[4-(2-Ethylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 104).
[0324] (uuuu-a) N-[4-(2-Ethylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 105); mp 178-180° C.
[0325] (vvvv) N-[4-(2-n-Propylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 106).
[0326] (vvvv-a) N-[4-(2-n-Propylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 107); mp 177-178° C.
[0327] (wwww) N-[4-(2-Isopropylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 108).
[0328] (wwww-a) N-[4-(2-Isopropylaminoethoxy)pyrid-3-yl]-4-oxo4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 109); mp 167-169° C.
[0329] (xxxx) N-[4-(2-n-Butylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 110).
[0330] (xxxx-a) N-[4-(2-n-Butylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 111); mp 157-159° C.
[0331] (yyyy) N-[4-(2-t-Butylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 112); mp 274-278° C.
[0332] (zzzz) N-[4-(2-Benzylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 113)
[0333] (zzzz-a) N-[4-(2-Benzylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 114); mp 143-145° C.
[0334] (aaaaa-a) N-[4-(Pyrid-3-ylmethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 115).
[0335] (aaaaa) N-[4-(Pyrid-3-ylmethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 116); mp 276-277° C.
[0336] (bbbbb) N-[4-(Pyrid-4-ylmethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 117).
[0337] (bbbbb-a) N-[4-(Pyrid-4ylmethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 118); mp 293° C.
[0338] (ccccc) N-{4-[(R)-Pyrrolidn-2-ylmethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 119); mp 195-198° C.
[0339] (ccccc-a) N-{4-[(R)-Pyrrolidn-2-yhnethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 120); mp 289-291° C.
[0340] (ddddd) N-{4-[(S)-Pyrrolidn-2-ylmethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 121); mp 138-141° C.
[0341] (eeeee) N-[4-(2-Dimethylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 122); mp 163-166° C.
[0342] (fffff) N-[4-(3-Dimethylaminopropoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 123); mp 247° C.
[0343] (ggggg) N-[4-(2-Pyrrolidin-1-ylethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 124)
[0344] (ggggg-a) N-[4-(2-Pyrrolidin-1-ylethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 125); mp 188-245° C. (d).
[0345] (hhhhh) N-[4-(2-Dimethylaminoethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 126).
[0346] (iiiii) N-{4-[2-(4-Methyl-piperazin-1-yl)ethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 127).
[0347] (jjjjj) N-{4-[2-Morpholin-1-ylethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compotnd 128).
[0348] (kkkkk) N-{4-[2-Piperidin-1-ylethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 129).
[0349] (kkkkk-a) N-{4-[2-Piperidin-1-ylethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrochloride (Compound 130); mp 208-211° C.
[0350] (lllll) N-{4-[(1-Methyl-pyrrolidin-3-yl)methoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 131); mp 209-211° C.
[0351] (mmmmm) N-{4-[(1-Ethyl-pyrrolidin-3-yl)methoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 132).
[0352] (nnnnnn) N-{4-[2-(1-Methyl-pyrrolidin-2-yl)ethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 133).
[0353] (ooooo) N-{4-[2-(1-Methyl-pyrrolidin-2-yl)ethoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide hydrate (Compound 134).
[0354] (ppppp) N-[4-(3-n-Propylaminopropoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 135).
[0355] (qqqqq) N-[4-(3-Cyclopropylmethylaminopropoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 136).
[0356] (rrrrr) N-{4-[3-(2-Ethylbutyl)aminopropoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 137).
[0357] (sssss) N-[4-(3-Cyclohexylaminopropoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 138).
[0358] (ttttt) N-[4-(3-Cyclohexylmethylaminopropoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 139).
[0359] (uuuuu) N-{4-[3-(Pyrid-4-ylmethyl)aminopropoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 140).
[0360] (vvvvv) N-[4-(2-Pyrrolidin-1-ylethoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 141); mp 148-150° C.
[0361] (wwwww) N-[4-(3-Di-n-propylaminopropoxy)pyrid-3-yl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 142).
[0362] (xxxxx) N-{4-[3-Di(c-propylmethyl)aminopropoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 143).
[0363] (yyyyy) N- {4-[3-Di(2-ethylbutyl)aminopropoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 144).
[0364] (zzzzz) N- {4-[3-Di(pyrid-4-ylmethyl)aminopropoxy]pyrid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 145).
[0365] (aaaaaa) N-{4-[2-(2-Pyrrolidin-1-ylethoxy)ethoxy]prid-3-yl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 146).
[0366] (bbbbbb) N-{4-[2-(2,2-Dimethylaminoethylamino)-2-oxoethyl]phenyl}-4-oxo -4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 147).
[0367] (cccccc) N-{4-[2-(4-Methylaminopiperizin-1yl)-2-oxoethyl]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 148); oil.
[0368] (dddddd) N-{4-[7-azabicyclo(2,2,1)hept-2-yloxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 149).
[0369] (eeeeee) N-[3-(2-Diethylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 150).
[0370] (ffffff) N-[3-(2-Pyrrolidin-1-ylethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 151).
[0371] (gggggg) N-[3-(2-Di-Isopropylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 152).
[0372] (hhhhhh) N-[3-(2-n-Propylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 153).
[0373] (iiiiii) N-[3-(2-n-Butylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole -3-carboxamide (Compound 154).
[0374] (jjjjj) N-[3-(Methylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 155).
[0375] (kkkkkk) N-{3-[3-(N-Ethyl,N-Methyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 156).
[0376] (llllll) N-{3-[3-(N-Cyclopropylmethyl,N-n-propyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 157).
[0377] (mmmmmm) N-[3-(Azeditinylpropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 158).
[0378] (nnnnnn) N-[3-(3-Ethylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 159).
[0379] (oooooo) N-{3-{3-(2,2,2-Trifluoroethyl)aminopropoxy]phenyl}-4-oxo- 1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 160).
[0380] (pppppp) N-[3-(3-n-Proplaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 161).
[0381] (rrrrrr) N-[3-(3-Isopropylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 163).
[0382] (ssssss) N-[3-(3-Cyclopropylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 164).
[0383] (tttttt) N-[3-(3-Cyclopropylmethylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 165).
[0384] (uuuuuu) N-[3-(3-Cyclobutylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 166).
[0385] (vvvvvv) N-[3-(3-Cyclohexylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 167).
[0386] (wwwwww) N-{3-[3-(3-Ethylpropyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 168).
[0387] (xxxxxx) N-{3-[3-(2-Methylpropyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 169).
[0388] (yyyyyy) N-[3-(3-Isobutylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 170).
[0389] (zzzzzz) N-[3-(3-t-Butylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 171).
[0390] (aaaaaaa) N-{3-[3-(2-Methylbutyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 172).
[0391] (bbbbbbb) N-[3-(3-Isoamylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 173).
[0392] (ccccccc) N-{3-[3-(4-Methylpentyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 174).
[0393] (ddddddd) N-{3-[3-(1,1 -Dimethylpropyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 175).
[0394] (eeeeeee) N-{3-[3-(3,3,-Dimethylbutyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 176).
[0395] (fffffff) N-{3-[3-(2,4-Dimethylpent-3-yl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 177).
[0396] (ggggggg) N-{3-[3-(4-Methylcyclohexyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 178).
[0397] (hhhhhhh) N-{3-[3-(4-t-Butylcyclohexyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 179).
[0398] (iiiiiii) N-{3-[3-(2,6-Dimethylcyclohexyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 180).
[0399] (jjjjj) N-{3-[3-(1-Phenylethyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 181).
[0400] (kkkkkkk) N-[3-(3-Norborn-2-ylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 182).
[0401] (lllllll) N-[3-(3-Adamant-1-ylaminopropoxy)phenyl]4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 183); mp 175-176° C.
[0402] (mmmmmmm) N-[3-(3-Norborn-2-ylmethylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 184).
[0403] (nnnnnnn) N-[3-(3-Adamant-2-ylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 185).
[0404] (ooooooo) N-[4-(2-Ethylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 186).
[0405] (ooooooo-a) N-[4-(2-Ethylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide hydrochloride (Compound 187); mp 227-228° C.
[0406] (ppppppp) N-[2-Fluoro-4-(2-Ethylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 188).
[0407] (qqqqqqq) N-[4-(2-n-Propylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 189).
[0408] (rrrrrrr) N-[4-(2-Cyclopropylaminoethoxy)phenyl]-4-oxo- 1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 190).
[0409] (sssssss) N-4-(2-n-Butylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 191).
[0410] (ttttttt) N-[4-(3 -Ethylaminopropoxy)phenyl]-4-oxo- 1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 192).
[0411] (uuuuuuu) N-{4-[3-(1-Phenyl-1-methylethyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 193).
[0412] (vvvvvvv) N-[4-(Pyrid-3-ylmethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 194); mp 241-243° C.
[0413] (wwwwwww) N-[4-(Pyrid-4-ylmethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 195).
[0414] (wwwwwww-a) N-[4-(Pyrid-4-ylmethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide hydrochloride (Compound 196); mp 235-240° C. (d).
[0415] (xxxxxxx) N-[4-(2-Dimethylaminoethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 197).
[0416] (yyyyyyy) N-[4-(2-Diethylaminoethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 198).
[0417] (zzzzzzz) N-[4-(2-Pyrrolidin-1-ylethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 199).
[0418] (zzzzzzz-a) N-[4-(2-Pyrrolidin-1-ylethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide hydrochloride (Compound 200); mp 160-162° C.
[0419] (aaaaaaaa) N-[4-(2-Piperidin-1-ylethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 201).
[0420] (bbbbbbbb) N-{4-[2-(1-Methyl-pyrrolidin-2-yl)ethoxy]pyrid-3-yl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 202).
[0421] (cccccccc) N-{4-[(1-Ethyl-pyrrolidin-3-yl)methoxy]pyrid-3-yl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 203); oil.
[0422] (dddddddd) N-[4-(2-Morpholin-1-ylethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 204).
[0423] (eeeeeeee) N-[4-(2-Diethylaminoethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 205).
[0424] (ffffffff) N-[4-(2-n-Propylaminoethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 206).
[0425] (ffffffff-a) N-[4-(2-n-Propylaminoethoxy)pyrid-3-yl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide hydrochloride (Compound 207); mp 210° C.
[0426] (gggggggg) N-[4-(2-Isopropylaminoethoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 208).
[0427] (hhhhhhhh) N-[4-(3-Isopropylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 209).
[0428] (iiiiiiii) N-[4-(3-Cyclopropylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 210).
[0429] (jjjjjjjj) N-[4-(3-Cyclobutylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 211).
[0430] (kkkkkkkk) N-[4-(3-Cyclopropylmethylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 212).
[0431] (llllllll) N-[4-(3-Isobutylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 213).
[0432] (mmmmmmmm) N-{4-[3-(2,2-Dimethylpropyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 214).
[0433] (nnnnnnnn) N-{4-[3-(3-Ethylpropyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 215).
[0434] (oooooooo) N-{4-[3-(2-Methylbutyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 216).
[0435] (pppppppp) N-{4-[3-(2-Methylpropyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 217).
[0436] (qqqqqqqq) N-[4-(3-i-Pentylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 218).
[0437] (rrrrrrrr) N-[4-(3-Cyclohexylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 219).
[0438] (ssssssss) N-{4-[3-(N-Cyclopropylmethyl,N-n-propyl)aminopropoxy]phenyl}-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 220).
[0439] (tttttttt) N-[4-(3-Indan-2-ylaminopropoxy)phenyl]-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxamide (Compound 221).
[0440] (uuuuuuuu) N-[3-Fluoro-4-(2-ethoxy-2-oxoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 222); mp 192-196° C.
[0441] (vvvvvvvv) N-[3-Fluoro-4-(2-hydroxy-2-oxoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 223); mp 246-248° C.
[0442] (wwwwwwww) N-[3-Fluoro-4-(2-ethylamino-2-oxoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 224).
[0443] (xxxxxxxx) N-[3-Fluoro-4-(2-diethylamino-2-oxoethoxy)phenyl]-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 225); mp 193-196° C.
[0444] (yyyyyyyy) N-{3-Fluoro-4-[2-(4-methylpiperizin-1-yl)-2-oxoethoxy]phenyl}-4-oxo-4,5,6,7-tetrahydro-1H-indole-3-carboxamide (Compound 226).
[0445] (zzzzzzzz) N-ethyl-N-[2-(ethylamino)ethyl]-2-{4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 227).
[0446] (aaaaaaaaa) N-[2-(dipropylamino)ethyl]-2-{4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 228); mp 148-150° C.
[0447] (bbbbbbbbb) N-[2-(diethylamino)ethyl]-N-methyl-2-{4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 229); mp 220-228° C.
[0448] (ccccccccc) N-[2-(diethylamino)ethyl]-N-ethyl-2-{4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 230); mp 165-167° C.
[0449] (ddddddddd) N-[4-(2-morpholin-4-yl-2-oxoethoxy)phenyl](4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carboxamide (Compound 231).
[0450] (eeeeeeeee) N-[3-fluoro-4-(2-morpholin-4-yl-2-oxoethoxy)phenyl](4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carboxamide (Compound 232); mp 110° C.
[0451] (fffffffff) (4-oxo-(4,5,6,7-trihydroindol-3-yl))-N-[4-(2-oxo-2-piperazinylethoxy)phenyl]carboxamide (Compound 233).
[0452] (ggggggggg) N-[3-(diethylamino)propyl]-2-{4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 234).
[0453] (hhhhhhhhh) N-[3-(diethylamino)propyl]-2- {2-fluoro-4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 235).
[0454] (iiiiiiiii) N-[4-(diethylamino)-1-methylbutyl]-2-{4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 236).
[0455] (jjjjjjjjj) N-[4-(diethylamino)-1-methylbutyl]-2-{2-fluoro-4-[(4-oxo-(4,5,6,7-tetrahydroindol-3-yl))carbonylamino]phenoxy}acetamide (Compound 237).
EXAMPLE 4
[0456] Water solubility for various compounds within the invention was determined and compared with that for compounds outside the scope of the invention. The compounds evaluated are encompassed within formula II:
II Water Solubility (μg/ml) R x R y n R 23 H H 1 203 H H 1 143 H H 2 15 H H 1 1.0 H H 1 0.58 H H 1 0.34 H H 1 0.26 CH 3 CH 3 1
[0457] The invention and the manner and process of making and using it, are now described in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same. It is to be understood that the foregoing describes preferred embodiments of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification. | Disclosed are compounds of the formula:
or the pharmaceutically acceptable non-toxic salts thereof wherein:
G, X, T, n, and R 3 -R 6 are as defined herein, which compounds are highly selective agonists, antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptors. These compounds are useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of invention relates to sprinkler apparatus, and more particularly pertains to a new and improved sprinkler shield wherein the same is arranged to receive a sprinkler head therethrough to afford protection and minimize vegetation growth about the sprinkler head.
2. Description of the Prior Art
Sprinkler heads that project through a surrounding lawn are typically subject to blockage from vegetation growth and overgrowth relative to the sprinkler head. Various prior art structure has been implemented to minimize such growth and such is exemplified in U.S. Pat. No. 3,514,040 to Carson utilizing a sprinkler cage positioned about a sprinkler head to afford protection to the sprinkler head.
The U.S. Pat. No. 3,762,642 to Di Santo sets forth a grass guard for sprinkler heads to surroundingly protect a sprinkler head relative to vegetation growth utilizing various sections that are of a step fit or relatively securable relative to one another.
U.S. Pat. No. 3,801,014 to Cantales sets forth a sprinkler cover to provide cover for sprinkler heads utilizing symmetrical parts forming a hollow cavity therebetween to receive a fluid pipe and sprinkler head therebetween.
U.S. Pat. No. 4,146,181 to Soos sets forth a guard ring for surroundingly receiving a sprinkler head therethrough.
It may be appreciated therefore that there continues to be a need for a new and improved sprinkler shield as set forth by the instant invention which addresses both the problems of ease of use as well as effectiveness in construction in accommodating sprinkler heads mounted within a lawn environment within various geographical and geometric positions within that lawn environment and in this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of sprinkler shield construction now present in the prior art, the present invention provides a sprinkler shield wherein the same is arranged to afford a cover for securement into an underlying surface surroundingly protecting a sprinkler head directed through the shield structure. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved sprinkler shield which has all the advantages of the prior art sprinkler shield construction and none of the disadvantages.
To attain this, the present invention provides a sprinkler shield arranged to receive a sprinkler head in a surrounding relationship to minimize vegetation growth thereabout. The shield is arranged with frangible portions to permit geometric tailoring of the shield relative to a sprinkler head environment. The shield structure further includes spike members mounted to a bottom surface of the shield for projection into an underlying ground surface.
My invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this particular combination of all of its structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention in order 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. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 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 designing of other structures, methods and systems for carrying out the several purposes to the present invention. It is important, therefore, 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.
Further, the purpose of the foregoing abstract is to enable the U.S. patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved sprinkler shield which has all the advantages of the prior art sprinkler shield construction and none of the disadvantages.
It is another object of the present invention to provide a new and improved sprinkler shield which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved sprinkler shield which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved sprinkler shield which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such sprinkler shields economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved sprinkler shield which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is an orthographic side view of the instant invention.
FIG. 2 is an orthographic bottom view of the instant invention.
FIG. 3 is an orthographic top view of a modification of the invention.
FIG. 4 is an orthographic view, taken along the lines 4--4 of FIG. 3 in the direction indicated by the arrows.
FIG. 5 is an orthographic view, taken along the lines 5--5 of FIG. 3 in the direction indicated by the arrows.
FIG. 6 is an orthographic top view of the shield structure utilizing a variously configured grooved surface construction to permit selective removal of portions of the
FIG. 7 is an isometric illustration of a spike member utilized by the invention.
FIG. 8 is an orthographic view, taken along the lines 8--8 of FIG. 7 in the direction indicated by the arrows.
FIG. 9 is an isometric illustration of the shield construction utilizing the spike members as illustrated in FIG. 7.
FIG. 10 is an orthographic view, taken along the lines 10--10 of FIG. 9 in the direction indicated by the arrows.
FIG. 11 is an isometric illustration of the invention arranged in various positions within a lawn environment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 to 11 thereof, a new and improved sprinkler shield embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
More specifically, the sprinkler shield 10 of the instant invention essentially comprises a rigid cylindrical plate 11, including a planar top surface 12 spaced from and parallel a planar bottom surface 13. A plurality of rigid mounting spikes 14 extend orthogonally downwardly relative to the planar bottom surface 13 terminating at a lowermost pointed end. A central bore 15 is coaxially directed through the cylindrical plate 11 and includes a plurality of radial slots 16 extending from the central bore 15 as the slots 16 are spaced ninety degrees apart to effect flexure in the plate construction in accommodating a sprinkler head to be received therethrough. The FIG. 2 illustrates a plurality of frangible grooves 17 intersecting one another at ninety degrees at a perimeter of the plate 11 to permit removal of segments of the plate to provide for positioning of a sprinkler head relative to a corner portion of a lawn, such as in the FIG. 11 set forth as item 23.
The FIGS. 3 and 5 illustrate the pairs of coextensive and aligned grooves 18 that extend radially relative to the bore 15, with confronting grooves directed into the top surface and bottom surface defining a pair to permit ease of separation of various segments of the plate to provide for the custom fitting of the plate structure relative to the lawn, such as the use of a corner segment 23 or a semi-circular segment 24 as illustrated in the FIG. 11. The FIG. 6 illustrates a further configuration utilizing the radial grooves as well as a plurality of concentric grooves to permit the use of a smaller circular plate if required.
The FIGS. 4 and 7-10 illustrate the plate structure 11 including a torroidal tube 19 coaxially and fixedly mounted to the bottom surface 13, with the tube including a liquid adhesive 20 contained therewithin. A plurality of spike base plates 21 are provided, with each spike base plate 21 including a spike 14 projecting downwardly and orthogonally relative to each spike base plate in a coaxial relationship, with the spike base plate orthogonally oriented relative to the axis of the spike 14, with the spike base plate further including a plurality of base plate spikes 22 projecting upwardly relative to the spike base plate 21. The plurality of base plate spikes 22 are arranged for projection into the torroidal tube 19 permitting the liquid adhesive 20 to fixedly secure the spike base plate 21 in an adjustable relationship relative to the tube 19 and the plate 11 to permit adjustment of the spikes relative to the plate to permit positioning of the spikes in a most advantageous position relative to a lawn environment.
As to the manner of usage and operation of the instant invention, the same should be apparent from the above disclosure, and accordingly no further discussion relative to the manner of usage and operation of the instant invention shall be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and 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. | A sprinkler shield is arranged to receive a sprinkler head in a surrounding relationship to minimize vegetation growth thereabout. The shield is arranged with frangible portions to permit geometric tailoring of the shield relative to a sprinkler head environment. The shield structure further includes spike members mounted to a bottom surface of the shield for projection into an underlying ground surface. | 1 |
APPLICATION FIELD OF THE INVENTION
[0001] The present invention refers to a medical device for detecting, measuring, and transmitting, in a non-invasive, continuous and instantaneous way, vital parameters of the human body, and other biomedical parameters, and consequent operations, especially for indicating the need of an intervention.
DESCRIPTION OF THE PRIOR ART
[0002] WHO (World Health Organization) defines health as “A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”.
[0003] Such definition defines the fundamental right to health.
[0004] Therefore a broader and broader demand is increasingly developing, not only for treating the different diseases, but above all for:
preventing the illnesses due to the increase of the average life expectancy; intervening in an early, prompt and adequate way for those acute diseases, above all cardiovascular and respiratory, which are a potential cause of death and which may provoke disabilities; controlling and monitoring vital parameters and clinical data in life-threatening chronic illnesses and/or to prevent the development of secondary handicaps.
[0008] In parallel to such a pressing demand, in all domestic economies the need for coherent and documented diagnosis arises, in order to give a justified access to both hospitalization and sophisticated, and therefore expensive, medical examinations and procedures, and thus avoid wasting precious economical resources.
[0009] Currently, by activating the different medical diagnostic devices, both in acute and in chronic diseases, it is not possible to obtain an immediate and general evaluation of those parameters, that in some patients are crucial to define the diagnosis and start a treatment, above all in the most urgent cases.
[0010] It is important to have access, above all, to fundamental detections:
in patients with chronic cardiovascular, respiratory diseases and in their emergencies due to relapse or complications; in healthy subjects which have an acute symptomatology referring to the cardiovascular and/or respiratory apparatus; in patients having chronic diseases for which some vital parameters need to be monitored.
[0014] Currently, medical devices that are able to provide and, at the same time, to send data in an instantaneous or continuous non-invasive way, in order to respond to such medical and diagnostic needs, for both acute and chronic cardiovascular and respiratory diseases, are not known in the art.
[0015] The known devices, such as for example the ones described in US2007/142738-A1 or in US2006/184059-A1, allow to record and to send heartbeat, and to record electromyography graphs in a non-invasive way, to evaluation centres.
[0016] In recent times, modern smartphones and tablets, which are actually starting to include pre-installed medical software applications, are also used for both receiving and transmitting analysis and responses to detection centres, also as a support of amateur and agonistic sport activities.
[0017] US2013/014706-A1 describes a collar-type device for veterinary applications to animals, which comprises some sensors adapted to measure the animal's parameters and to transmit them, also remotely. The device comprises an inflatable band adapted to create a tension of the collar against the neck of the animal, so as to keep it still and adherent in order to press the sensors against the neck of the animal itself. In addition to the functional limitations of such device, and to the dangerousness of pressing a collar against the neck of a person, it is not adapted to applications to the human body, as it is not possible to obtain reliable detections for critical parameters, nor for other complex parameters that are useful and necessary in the cardiovascular and respiratory emergencies.
[0018] Currently, medical devices adapted to the use on human body that have all the following requirements are not known in the art:
ability to detect, record and transmit vital parameters and complex biomedical parameters to the home or to the hospital; ability to carry out immediate or remote operations for cardiovascular emergencies, using a single or multiple parameters; easy application to patient; ability to store the parameters detected, both wired and wireless interactivity on smartphones, PCs and networks; ability to localize and identify the device and thus the patient; flexibility to implement the connection of detectors of other parameters; non-invasiveness; simple management.
SUMMARY OF THE INVENTION
[0027] Therefore the aim of the present invention is to provide a medical device adapted to detect, to measure, in a bloodless and non-invasive way, and to transmit vital, biomedical parameters, such as cardiovascular and respiratory ones, of the human body, able to overcome all the aforementioned drawbacks.
[0028] It is an object of the present invention a medical device adapted to detect, to measure, in a bloodless and non-invasive way, and to transmit vital, biomedical parameters, such as cardiovascular and respiratory ones, of the human body, the device being characterized in that it comprises:
a flexible strip-shaped support (COL, SUP) adapted to be applied on the human body in the area of the neck; one or more units (U 1 , U 2 , . . . Un) adapted to detect body parameters; one or more connection interlaces (USB, WL) for transmitting and receiving data and said parameters towards external units; hardware and software electronic components integrated inside the flexible support and adapted to receive said body parameters from said one or more units (U 1 , U 2 , . . . Un), to store them, to organize them and to transmit them as encrypted or not encrypted by means of said one or more connection interfaces (USB, WL). said device being adapted to record an electrocardiography in a continuous or instantaneous way, to acquire the Doppler ultrasonography of ascending aorta, to acquire m-B mode echocardiography, to immediately or remotely operate on emergency intervention units such as a temporary transcutaneous pacemaker and/or a cardiac defibrillator.
[0034] It is particular object of the present invention a medical device adapted to detect, to measure, in a non-invasive way, and to transmit vital, biomedical parameters, such as cardiovascular and respiratory ones, of the human body, as described more fully in the claims that are considered as an integral part of the present description.
BRIEF DESCRIPTION OF THE FIGURES
[0035] Further aims and advantages of the present invention will become more apparent from the following detailed description of an embodiment thereof (and of its alternative embodiments) and from the annexed drawings, which are supplied by way of non-limiting example, wherein:
[0036] FIG. 1 shows a first embodiment of the device that is object of the present invention;
[0037] FIG. 2 shows the device of FIG. 1 extended in a straight line, with indication of the elements connected to it;
[0038] FIGS. 3 and 4 show a second embodiment of the device that is object of the present invention, with units that can be assembled separately or that are assembled on one single support;
[0039] FIG. 5 shows an example of application of the device for measuring medical parameters in some body areas;
[0040] FIGS. 6.1, 6.2 show two possible embodiments of the device.
DETAILED DESCRIPTION OF EMBODIMENTS
[0041] In a first embodiment, with reference to FIGS. 1 and 2 , the device is shaped, by way of example, as a collar COL formed by a strip-shaped flexible support made of suitable material, an appropriate fastening device (not shown), for example a clip or a button, being placed at its ends.
[0042] A number of units U 1 , U 2 , . . . made in a way per se known and able to detect body parameters are connected to the device COL. Each unit is adapted to be connected to one or more relating explorers EXP 1 , EXP 2 , . . . EXPn either by means of possibly extendable and retractable wires, or in wireless mode.
[0043] In addition, further connection interfaces, such as USB, WL (wireless) are connected to the device COL for transmitting and receiving data and parameters towards suitable external units.
[0044] The device (COL) further comprises connections for battery recharging (RB), by using modern technology for installing batteries that ensures its safety and durability, possibly using micro solar panels to have another energy source.
[0045] For the identification and localization of the patient, to which the device is applied, GPS satellite localizers are placed on the site LI. Also, in such site, a microchip is positioned for the identification of the patient using a PIN or other identification sequence.
[0046] Furthermore, in such site LI a SIM card is inserted which provides both the patient localization and identification either on WEB or on other detection device, protecting his/her privacy.
[0047] By adding a SIM card, the device acquires an important smartphone function, with all its current and future operating potential. That, in addition to all of its multiple applications (for example a micro-camera), allows the patient to have a normal cell phone available that connects him/her directly (also using speakerphone or earphones) to other apparatuses or to a help centre, providing immediately his/her position, his/her identification and the possibility of talking directly to the operators.
[0048] The device COL, of reduced dimensions, may become a smartphone by just inserting the SIM card, freeing the patient's, or any possible user's, hands and being itself either only a smartphone or a device able to send an help request to help centres.
[0049] What just said about localization and identification of the patient, may and will be improved by new micro-technologies.
[0050] The eccentric, namely peripheral, position of the site LI (Localization, Identification) and KB (battery recharging) on the collar allows to avoid any interference with the normal bioelectric activity of the heart.
[0051] The units U 1 , U 2 , . . . Un and the interfaces USB, WL are connected to suitable hardware and software components integrated in the device, and adapted to receive the data detected by the units, store them, organize them and transmit them, in a not encrypted or encrypted way for privacy reasons, immediately or at suitable times, even on demand, to external units such as PC, tablets, smartphones, being them single or organized in a network, placed at the patients' home or in evaluation centres where data can undergo further processing and integration using hardware and software suitable for the detected data. The latter may, in its turn, offer immediate responses or communicate with patients or medical, paramedical personnel at the patients' home or at a hospital.
[0052] The electronic components of the collar COL are battery-powered: the batteries BT can be integrated inside the collar.
[0053] The collar or necklace shape is important as it is anatomical and can be applied in an anatomically suitable area on the human body. Thus the collar or necklace shape is crucial for making its usage easy and effective; this is because it can be worn fast and easily, as it is located in the proximity of most of the organs of cardiovascular and respiratory interest that is object of the detection of biomedical parameters.
[0054] The device COL can be made in a single piece or by articulated meshes, for example of the modular type, each mesh being able to connect a respective unit, so as to combine consecutive units.
[0055] The collar can be made of light, anallergic material, made of carbon fibre with a fastener, e.g. having dimensions 3 cm×80 cm.
[0056] The different units U 1 , U 2 , . . . Un can be activated only if needed, not necessarily all together. They can be connected externally to one or both most elongated sides of the collar.
[0057] The different units are expected to communicate with each other by means of the electronic components of the collar, for example defibrillator and cardiac arrhythmia detector: once the arrhythmia is detected, it is communicated to the defibrillator which is immediately activated.
[0058] A second embodiment of the medical device is shown in FIGS. 3, 4 e 5 .
[0059] The device comprises essentially:
a flexible strip-shaped support SUP, preferably collar or necklace shaped; it comprises folds RB 1 , RB 2 at the edges of the longer sides so as to make a rail on which the different detection or possibly transmission operating units U 21 . . . U 2 n , or a single case containing tile different units U 21 , . . . U 2 n , can be inserted in a sliding and removable way. The strip of the flexible support is thus turned towards the inner side of the support towards the body of the person, while its opposite outer side remains open, in order to show most of the surface of the elements accommodated inside the support. detection and possibly transmission operating units U 21 . . . U 2 , Un, which can be made by single components which carry out the different functions, or a single case that supports the different operating units. exploring probes EXP 1 , EXP 2 , . . . EXPn adapted to be connected to said operating units UI . . . Un by means of connections E 21 . . . E 23 and possibly extendable and retractable wires or in wireless mode. plates placed on the anatomical sites of the person to be analyzed, adapted to connect said explorers and wires to the body. Plates are of a type known in the art, adapted to ensure a long adherence, in an anallergic way, and make the adherence, the data transmission and thus the reading perfect, reducing the recording errors. Said plates may serve as detectors, data integration and transmission in wireless, Bluetooth or other mode, to allow a new type of mobility in the data transmission. at least one display D preferably of the touchscreen type. Time presence of the touchscreen display may allow the user or the operator, with respective suitable icons, to use immediately all the functions of the device, including all its operations and data storing. at least one SIM card with the functions described above with reference to the first embodiment of the device. at least one battery BT compartment, preferably of the rechargeable type. miniaturized solar panels PS for battery recharging and for increasing the endurance and the mobility of the device. USB ports to connect other devices wireless, Bluetooth telecommunication devices connection (not shown), also of the wireless type, for a keyboard for the input of data and commands.
[0071] Other general characteristics can be referred to what described above with reference to the first embodiment of the device.
[0072] FIG. 5 shows examples of anatomical sites, where the mentioned detections and operations take place, such as:
area of the neck, at the base of the neck right and left second parasternal intercostal space fifth space on the left midclavicurlar line right dorsal scapular and interscapular area.
[0077] FIGS. 6.1, 6.2 show two possible embodiments of the device with flexible collar or necklace shaped support, to allow an easy application on the neck area of the person.
[0078] The flexible support can be made of plastic or carbon fibre with a fastener, e.g. having dimensions 3 cm×80 cm.
[0079] The particular shape of the device allows, for example:
any easy application on the neck area of the patient; an easy access for the detectors to the anatomical sites from which they can
[0082] a—display the vital parameters that are object of the detection, namely: skin temperature, arterial pressure, Sp02%; heartbeat;
[0083] b—acquire the Doppler ultrasonography of ascending aorta;
[0084] c—record the ECG (electrocardiography) in a continuous and instantaneous way;
[0085] d—acquire M-mode and B-m echocardiography (parasternal and apical 5 chamber view)
[0086] e—intervene, from an operation point of view, with PM (temporary transcutaneous pacemaker) and cardiac defibrillator.
[0087] f—localize and identify the patient quickly;
[0088] g—make its shape flexible, which can be modified and lightened;
[0089] h—have pre-programmed cut-offs, which can be visual or acoustic, thus limiting the data transmission and providing immediately an alert warning to the user;
[0090] i—reduce improper or incoherent hospitalization having documented the data of the diseases that are object of the detection;
[0091] l—have fast operating responses with an overall picture documented by the diseases that are object of the data detection;
[0092] m—communicate, also using the smartphone function inserted in the collar, with the patient providing him/her with indications;
[0093] n—let the patient free from the fear to be far from an help centre.
[0094] o—access to the display for setting, desired information and necessary operations.
[0095] Indeed, the clinical data acquired by the device, by using detectors placed in well-defined anatomical areas, are not just relating to vital parameters detected by a generic rescuer, by the so-called “primary exam” (arterial pressure, heartbeat, body temperature, consciousness), but also to more complex cardiovascular and respiratory data (electrocardiography, Doppler ultrasonography of carotid axis, percentage of oxygen saturation), that, in acute emergencies, above all cardio-respiratory ones, may provide documented data adapted to provide operating responses at different levels, namely:
immediately on the patient; by activating a complete information that may remotely command the response units inserted in the device (temporary transcutaneous pacemaker; defibrillator); by creating an information flow that allow the highest promptness and effectiveness in the medical intervention (ambulance, emergency room, etc.).
[0099] The device that is object of the patent is a medical device, in the sense that its application, management, and the interventions that are considered appropriate are in charge of specialized medical personnel only. Users may possibly have access to simple detections (skin temperature, arterial pressure, heartbeat), but always under medical supervision.
[0100] It will be apparent to the person skilled in the art that other equivalent embodiments, and their combinations, of the invention can be conceived and reduced to practice without departing from the scope of the invention.
[0101] The elements and the characteristics shown in the different preferred embodiments can be combined with each other without departing from the scope of the present patent.
[0102] From the description set forth above the person skilled in the art is able to realize the object of the invention without introducing further constructive details. | A medical device for detecting, measuring and transmitting vital parameters and biomedical data such as the continuous or instantaneous recording of an electrocardiography, acquisition of a Doppler ultrasonography of ascending aorta and of a echocardiography, with immediate or remote operations, by means of units inserted in the device, on the human body, in a non-invasive way, comprising: a flexible strip-shaped support adapted to be applied on the human body in the area of the neck; one or more units adapted to detect body parameters; one or more connection interfaces for transmitting and receiving data and the parameters towards external units; hardware and software electronic components integrated inside the flexible support and adapted to receive the body parameters from the one or more units, store them, organize them and transmit them by connection interfaces; a sim card allowing transmission and reception. | 0 |
BACKGROUND OF THE INVENTION
[0001] A. Field of the Invention
[0002] The present invention relates to point of sale equipment and, more particularly, to methods and apparatus for generating secure endorsed transactions. The invention facilitates the generation of secure endorsed transactions by combining data representative of a transaction with a unique human identifier representative of the human that endorsed the transaction, such as a biometric, in a way that neither the transaction data nor the human identifier can be altered without detection.
[0003] B. Description of the Related Art
[0004] The credit card has become one of the primary methods of paying for goods and services throughout the world. People use credits cards every day to pay for a wide variety of goods and services, such as: food at a grocery store, clothes at a department store, gas at a gasoline station, airline tickets at a travel agent, automobiles at a car dealer, etc. Because of the nature of credit cards they have also become a primary means for transacting business over the Internet, another source of goods and services.
[0005] In order for a credit card transaction to be processed, a merchant must collect a variety of data associated with the transaction. This data typically includes the purchase price and date of the transaction, the account number and expiration date of the credit card, and the cardholder's name. The merchant may also collect the cardholder's signature, although it is generally not considered a part of the transaction data.
[0006] Once the transaction data is collected, the merchant transmits it, along with data identifying the merchant, to a credit card transaction processor. The credit card processor sorts the data according to the company that issued the credit card, and forwards the data to the appropriate company. At that point, the credit card issuer posts the transaction to the cardholder's account and the purchase amount is credited to the merchant.
[0007] In the past, credit card transaction data was recorded, transferred, and stored in the form of paper receipts. Over the years, the credit card industry has developed equipment that provides for the electronic acquisition, transmission, and storage of transaction data. This equipment, which is sometimes referred to a point of sale (POS) equipment, usually includes electronic terminals that read the account number and expiration date from a magnetic stripe on the credit card and transmit the transaction data to the credit card processor. In addition to reducing the industry's reliance on paper records, this equipment expedites the processing of credit card transactions and minimizes errors associated with the entry of transaction data.
[0008] Despite these advances, the typical credit card transaction still relies primarily on paper. For example, a cardholder presents a credit card to a merchant, who records transaction data using an electronic terminal. The recorded data includes the amount of the purchase, the cardholder's account number, the card's expiration date, the merchant identification number, and the date of the transaction. Once the terminal accumulates the transaction data, the terminal automatically dials the merchant's credit card processor or other authorization source and initiates an authorization request. When the transaction is authorized, the terminal displays and/or stores the approval code or authorization indicia received from the credit card processor. The approval code is recorded along with the other transaction data. The POS equipment typically includes a printer that is capable of printing a sales receipt. The sales receipt includes the transaction data and approval code, and provides a space for the cardholder's signature.
[0009] These prior art devices allow numeric data, such as purchase price, date, account number, and merchant identification number to be easily accumulated, stored, and transmitted between the merchant and credit card processor. Consequently, numeric transaction data may be transferred and stored without the use of paper receipts. Although this numeric data is sufficient to process the transaction, it is generally regarded as insufficient to validate or authenticate a transaction that is disputed by the cardholder. In the event a cardholder questions or denies the legitimacy of a transaction that appears on his or her credit card statement, it may be necessary for the merchant to produce a copy of the signed receipt as evidence that the cardholder was a party to the transaction. The signed receipt contains all of the necessary transaction data (date, time, store identification, sale items, prices, taxes, and signature) to verify the transaction. Therefore, it is necessary that a copy of each signed receipt be retained by the merchant for some period of time.
[0010] The storage and retrieval of signed receipts is costly, in terms of space, resource, and labor. Since the receipts must be stored for a long period of time, it is not uncommon for merchants to have a centralized storage area that encompasses tens of thousands of square footage of file cabinets containing the paper slips. Many merchants elect to convert the paper to microfiche and pay fees for shipping, conversion and storage. There is cost associated with the paper itself, as well as postage in sending the paper slips from the retail stores to the centralized storage location. Labor costs occur all throughout the handling process, from the shipment of the paper to the storage and retrieval of the paper. It is also not uncommon for a large merchant to staff 20 or more full-time employees whose sole function is to retrieve the paper slips to settle customer disputes.
[0011] Beyond the storage and retrieval of the receipts, lies a cost associated with the failure to locate them when necessary. Failure to locate a receipt is not uncommon because of the inherent difficulties of storing large quantities of paper, (especially in retail because the physical size of the paper is small) and the fact that there is typically a time frame associated with retrieving the paper. When working with credit card issuers, the time frame can be as short as 48 hours. This means that if the receipt is not located in 48 hours, then the receipt is considered either lost or was never in existence. In either case, the merchant will lose the amount of the sale that is sometimes referred to as a charge back.
[0012] This process of retaining and retrieving signed receipts is made easier if the merchant employs POS equipment that allows the cardholder's signature to be digitized, transmitted, and stored along with the numeric data associated with the transaction. See, for example, U.S. Pat. No. 5,448,044. In such cases, the signature is digitized the cardholder signs the credit card receipt. The digitized signature data and numeric transaction data are combined and transmitted to the credit card processor, where the data is stored for a predetermined period of time. If a cardholder disputes the validity of a transaction, the entirety of the transaction data, including a facsimile of the signature, may be provided by the credit card processor, and may serve as evidence of the legitimacy of the transaction. See, for example, U.S. Pat. No. 5,428,210 for a “Data card terminal with embossed character reader and signature capture.”
[0013] While the combination of digitized signature data and numeric transaction data provides evidence of the legitimacy of the transaction when a dispute arises, it is not tamper resistant. Specifically, conventional systems that provide a combined digitized signature data and transaction data fail to address the problems associated with security of the combined data. For example, the digitized signature data associated with the transaction data for one transaction may be misappropriated and assigned to the transaction data for a different transaction. Similarly, transaction data itself may be modified or altered, thereby corrupting the data and making it, as well as the associated digitized signature data, unreliable.
SUMMARY OF THE INVENTION
[0014] Accordingly, the present invention is directed to methods and apparatus for generating secure endorsed transactions that obviate one or more of the problems due to limitations and disadvantages of the related art.
[0015] Features and advantages of the invention 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 invention. The objectives and other advantages of the invention will be realized and attained by the method and apparatus particularly pointed out in the written description and claims thereof as well as the appended drawings.
[0016] To achieve the objective of this invention and attain its advantages, broadly speaking, this invention includes a method of generating secure endorsed transactions comprised of transaction data representative of transactions and unique identifiers corresponding to parties endorsing the transactions. In its broadest sense, the method has two steps, which would be performed by a data processing system. First, the system receives transaction data and unique identifiers. Then it generates unique codes from the transaction data and unique identifiers. The unique codes constitute secure endorsements of the transaction data by the parties corresponding to the unique identifiers.
[0017] According to another aspect of the present invention, there is provided a method of generating tamper resistant secure endorsed transactions comprised of transaction data representative of transactions, unique human identifiers corresponding to at least one party, called first party, endorsing a transaction, and public keys corresponding to at least a second party endorsing a transaction. The public keys have corresponding private keys maintained in secret by the second party. The method has three steps, which are performed by a data processing system. First, the system receives a transaction data, a unique human identifier, and a public key. Next, a unique code is generated from the transaction data, the unique human identifier, and the public key. The unique code constitutes a secure endorsement of the transaction data by the first party. Lastly, using a private key corresponding to the received public key, a digital signature is generated by encrypting the unique code using the private key. The digital signature constitutes a secure endorsement of the transaction data by the second party.
[0018] The present invention also involves methods for verifying the secure and tamper resistant secure endorsed transactions. Further, smart cards may be used to provide part of the transaction data being used for the secure and tamper-resistant secure transactions, and to store the previously generated secure and tamper-resistant secure transactions.
[0019] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings which are incorporated in and which constitute part of this specification, illustrate a presently preferred implementation of the invention and, together with the description, serve to explain the principles of the invention.
[0021] In the drawings:
[0022] FIG. 1 is a block diagram of the hardware architecture for a secure endorsed transaction system according to an embodiment of the present invention;
[0023] FIG. 2 is an operational flow chart of the process used for generating a unique code based on both data representative of a transaction and a unique human identifier, according to the embodiment of the present invention;
[0024] FIG. 3 is an operational flow chart of the procedure used to create single whole representations of secure endorsed transactions according to the embodiment of the present invention;
[0025] FIG. 4 is an operational flow chart of the procedure used to verify the integrity of a secure endorsed transaction according to the embodiment of the present invention;
[0026] FIG. 5 is an operational flow chart of a process used for generating a digital signature based on data representative of a transaction, a unique human identifier corresponding to one party who has endorsed the transaction, and a public key corresponding to a second party who has endorsed the transaction, according to the embodiment of the present invention;
[0027] FIG. 6 is an operational flow chart of the procedure used to create single whole representations of secure endorsed transactions using digital signatures, according to the embodiment of the present invention;
[0028] FIG. 7 is an operational flow chart of the procedure used to verify the integrity of a secure endorsed transaction using digital signatures, according to the embodiment of the present invention;
[0029] FIG. 8 is a process flow chart of the steps used to create a secure endorsed transaction, according to the embodiment of the present invention;
[0030] FIG. 9 is a process flow chart of the steps used to verify a secure endorsed transaction, according to the embodiment of the present invention;
[0031] FIG. 10 is a process flow chart of the steps used to create a secure endorsed transaction using digital signatures, according to the embodiment of the present invention; and
[0032] FIG. 11 is a process flow chart of the steps used to verify a secure endorsed transaction created using digital signatures, according to the embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] Reference will now be made in detail to the preferred implementation of the present invention as illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same or like parts.
[0034] The present invention provides the capability for generating secure endorsed transactions. In the area of credit card transactions, secure endorsed transactions are created, for example, at the POS, by (1) combining data representative of a transaction (e.g., date, time, merchant identification, sale items, prices, and taxes) with a unique human identifier associated with the credit card holder (e.g., digitized signature, biometric, retinal pattern, and finger print), and (2) generating a unique code based on the combination that is representative of the endorsed transaction. The unique code may be generated by using a checksum algorithm such as CRC or XOR or a message digest from RSA Data Security, Inc., USA (see BSAFE, User's Manual, Version 2.1, p. 42, 1992), or other algorithms with similar characteristics. This unique code is stored for use during verification process.
[0035] Verification that the combined data is unmodified, and thus, original, is done by recalculating a new computed unique code based on the combined data and comparing the new computed code with the original stored unique code. If the comparison is a match, the data is unmodified and thus, original. If the comparison fails, the data is modified and thus, not original.
[0036] By use of public keys or like algorithms, the combined data can be further processed to demonstrate authenticity.
[0037] FIG. 1 shows the hardware architecture for a secure endorsed transaction system 100 according to an embodiment of the present invention.
[0038] The system 100 includes a workstation 110 , which includes hardware for a standard personal computer (for example, an IBM compatible personal computer) and an identification input device 120 , and an optional smart card I/O device 130 . For credit card applications, the system 100 may be located at the POS. Other examples, such as online insurance enrollment, may have the system 100 functioning as a laptop computer and be located at the enrollment location, or for medical treatment authorization, the system 100 may be located at the patient admissions office, or for finance applications, the system 100 may be located at the bank's branch office, or for I-9, W4, and related personnel files, the system 100 may be located in the human resource department, or for an online driver license application, the system 100 may be located at the Department of Motor Vehicles branch locations.
[0039] Alternatively, part of the system, i.e., workstation 110 may be located at a remote location with electrical connections to the identification input device 120 .
[0040] The workstation 110 consists of a microprocessor 140 , random access memory (RAM) 150 , hard disk 160 , floppy disk and drive 170 , video display 180 , keyboard 190 , and mouse 195 . These may be standard off-the-shelf hardware. For example, the microprocessor 140 may be a Pentium® processor manufactured by Intel Corp., USA, and the video display 180 may be a NEC MultiSync 3V monitor manufactured by NEC Corp., Japan. Alternatively, the workstation 110 may include one or more specialized digital signal processing chips as coprocessors to support processing functions described below.
[0041] The RAM memory 150 may be substituted with other memory devices such as PROM that are suitable for storing programs. The storage devices, hard disk 160 , floppy disk 170 are optional and only necessary for local storage. Alternatively, the storage may be located remote from the microprocessor 140 and RAM memory 150 with appropriate interconnections to access the storage devices. Further, other storage devices such as CD-ROMs, Hierarchial File Systems, Magnetic Tapes, may be employed. The video display 180 , keyboard 190 , and mouse 195 are optional devices and not necessary to the invention.
[0042] The identification input device 120 may be a signature capture device such as the PenWare2000 manufactured by PenWare, Inc., Palo Alto, Calif., USA, or other similar device capable of capturing a digitized signature, which is a unique identifier associated with its author. Alternatively, the device 120 may be a finger print scanner, retinal scanner, or other biometric input device. The one thing common to all of the these exemplary input devices is that they generate a unique identifier associated with an individual that is unique to the individual and non-transferable.
[0043] The optional smart card I/O device 130 may also be comprised of conventional hardware. One such smart card I/O device is manufactured by Neuron Electronics Inc., U.S.A. Alternatively, the smart card may be attached directly to the system 100 .
[0044] The system 100 may also include a telephone port or other communication port (not shown) for connecting the workstation 110 to a public switched telephone network or another type of network, such as the Internet, an Intranet, LAN, WAN, etc. Such a telephone port would include a switch, which may be controlled by the microprocessor 140 (and also by DTMF tone receivers in the telephone port), that can connect a telephone (not shown) to the public switched telephone network or to the microprocessor 140 . A telephone port would be required if the workstation 110 is connected to the identification input device 120 at a remote location, in which case both the workstation 110 and remote POS equipment such as the remote input identification device 120 may include conventional modems capable of electrically connecting them via a public switched telephone network. Those skilled in the art will recognize that there are many other methods for electrically connecting identification input device 120 of the type described above with the workstation 110 .
[0045] (1) Creating Tamper-Resistant Secure Endorsed Transactions
[0046] FIG. 2 is an operational flow chart of the procedure used by the workstation 110 to combine transaction data 210 , which in this example, is a credit card transaction receipt, with a unique human identifier 220 associated with an individual, for example, a credit card holder, who has endorsed the transaction, in this example, a credit card transaction, and to generate a unique code 240 based on the combination that is representative of the endorsed transaction. As shown, both transaction data 210 , which is data representative of a transaction and may include, among other items, date, time, merchant identification, sale items, prices, and taxes, as well as printer language commands, form description language commands, form definition commands, and a unique human identifier 220 , which may be a digitized signature, biometric, retinal pattern, and finger print, or the like, are provided to a unique code processor 230 that generates a unique code corresponding to the inputs 210 and 220 . Those skilled in the art will recognize that various other transactions, such as on-line insurance enrollment forms, patient admission forms, finance applications, personnel files, on-line driver license applications and the like, may be used in place of the POS credit card example without detracting from the scope of the present invention.
[0047] The unique code processor 230 is a software program, for example, executed by the microprocessor 140 , that satisfies the following conditions: (1) The processor 230 generates a unique code based on the inputs 210 and 220 that is computationally infeasible to duplicate. (2) It is computationally infeasible for the processor 230 to produce the same code from different combinations of the inputs 210 and 220 .
[0048] In the preferred implementation, the processor 230 is comprised of a message digest software program produced by RSA Data Security, Inc., USA. Alternatively, checksum software programs or other comparable software may be used, provided they meet the criteria outlined above.
[0049] FIG. 3 is an operational flow chart of the procedure for generating a secure endorsed transaction using the unique code 240 . First, it should be understood that the unique code 240 generated by the unique code processor 230 is a secure endorsement of the transaction in the transaction data 210 by the individual identified in the human identifier 220 , which was used by the processor 230 to generate the unique code 240 . A secure endorsed transaction consists of a combination of the transaction data 210 , human identifier 220 , and unique code 240 . As shown in FIG. 3 , the transaction data 210 , human identifier 220 , and unique code 240 are combined by a formatter 310 , and the resulting combination constitutes a secure endorsed transaction 320 of the transaction specified in the transaction data 210 . The formatter 310 is a software program, for example, executed by the microprocessor 140 that combines the three inputs 210 , 220 , and 240 into a single representation, called a single whole representation of the secure endorsed transaction, which may be stored in the hard disk 160 , floppy disk 170 , or another storage device such as a WORM (write once readable memory) like a CD-ROM.
[0050] The single whole representation of the secure endorsed transaction 320 may also be stored on a smart card using the device 130 . According to this aspect of the present invention, the smart card may contain both credit card information for the transaction as well as a copy of single whole representation of the secure endorsed transaction 320 . The device 130 could be used to read the credit card information from the smart card and to store the transaction information onto the smart card. This way the credit card (read, smart card) holder has an electronic copy of the transaction data or receipt or single whole representation of the secure endorsed transaction 320 that may be compared with a copy stored by the merchant for verification purposes.
[0051] For credit card transactions, the unique code processor 230 and formatter 310 may be employed in POS equipment to allow merchants to store the single whole representations of secure endorsed transactions. In such cases, the transaction data 210 and the human identifier 220 would be captured at the POS as the cardholder, for example, signs the credit card receipt. The unique code processor 230 and formatter 310 would then generate the single whole representation of secure endorsed transaction 320 that can be transmitted to the credit card processor, where the data is stored for a predetermined period of time. Alternatively, the single whole representation of secure endorsed transaction 320 may be stored at the merchant's site, removing the dependency a merchant has on the transaction processor. Because the integrity of the single whole representation of the secure endorsed transaction 320 is critical to the operation of the system 100 , mass storage devices that provide write-once read-many times capability are particularly appropriate for storing the single whole representation of the secure endorsed transaction 320 when the underlying transaction involves the use of a credit card.
[0052] FIG. 8 illustrates the procedure 800 used by the system 100 to generate secure endorsed transactions. In the preferred embodiment, the procedure 800 is implemented in software executable by the microprocessor 140 .
[0053] As a first step in the process, the microprocessor 140 receives transaction data and a human identifier (step 810 ). As explained above, the transaction data typically includes data related to a transaction such as a retail purchase. The human identifier (such as a biometric, signature, finger print, retinal print, etc.) corresponds to a human that has endorsed the transaction, for example, the individual making the retail purchase. (The transaction data and human identifier may come from POS equipment in a merchant's establishment or from comparable equipment located elsewhere. For example, it may be possible to connect the POS-type equipment to computers connected to the Internet, thus using the Internet for secure endorsed transactions.)
[0054] Next, using the unique code processor 230 , the microprocessor 140 , generates a unique code from the transaction data and human identifier (step 820 ). The combination of this unique code and the input transaction data and human identifier constitute a secure endorsed transaction because if either the transaction data or human identifier is altered in any way, a unique code matching the endorsed transaction data could not be recreated. This is, however, a function of the unique code processor 230 , as explained above.
[0055] The secure endorsed transaction may be stored in a database, with the component parts (transaction data, human identifier, and unique code) in tables or the like (step 840 ), as shown in the procedure 800 by the broken line connecting steps 820 and 840 . Alternatively, before storing the secure endorsed transaction (step 840 ), the secure endorsed transaction may also be combined into a single whole presentation of the secure endorsed transaction. Using the formatter 310 , the microprocessor 140 would combine the individual components of the secure endorsed transaction into a single whole representation of the secure endorsed transaction (step 830 ). The single whole representation of the secure endorsed transaction could then be stored as one data item representing the transaction (step 840 ). One advantage of step 830 is that it permits a subsequent transmission of the single whole representation of the secure endorsed transaction as one data item to, for example, a credit card transaction processor for approval of the transaction and/or long term storage.
[0056] (2) Verifying Tamper-Resistant Secure Endorsed Transactions
[0057] FIG. 4 is an operational flow chart of the procedure used, for example, by microprocessor 140 , to verify a secure endorsed transaction 320 . As shown, the verification procedure is substantially the reverse of the procedures outlined in FIGS. 2 and 3 for creating the secure endorsed transaction. First, the formatter 310 is used to decompose the secure endorsed transaction into the component parts: transaction data 210 , human identifier 220 , and unique code 240 . The decomposed transaction data 210 and human identifier 220 are then processed by the unique code processor 230 to generate a new, computed unique code 410 . The decomposed unique code 240 from the secure endorsed transaction 320 and the computed unique code 410 are then processed by a compare processor 420 to determine whether there is a match. If not (i.e., the computed code does not equal the decomposed unique code), then the secure endorsed transaction 320 was changed and, thus, tampered with prior to execution of the verification procedure (and an appropriate error message or other signal is generated). The compare processor 420 is a software program, for example, executable by the microprocessor 140 . The program compares two inputs to determine if they are identical.
[0058] Alternatively, if the compare processor 420 determines that the codes 410 and 240 match, then the secure endorsed transaction 320 (is original and) was not tampered with prior to verification. At this time, the secure endorsed transaction 320 can be processed, for example, displayed, faxed, printed, etc. In the credit card example, the secure endorsed transaction 320 could be printed as a signed credit card receipt for visual inspection and verification by humans.
[0059] Those skilled in the art will recognize that various modifications may be made to the preferred embodiment without detracting from the scope of the present invention. For example, instead of using the formatter 310 to create a single whole representation of the secure endorsed transaction 320 , the human identifier 220 , transaction data 210 , and unique code 240 may be stored in a database, such as a relational database, located, for example, on the hard disk 160 . In this case, the verification process would also not involve the use of the formatter 310 . Instead, transaction data 210 and a corresponding human identifier 220 are extracted from the database, processed by the unique code processor 230 to generate a new computed unique code 410 , which would then be compared by the compare processor 420 with the unique code 240 stored in the database as corresponding to the transaction data 210 and human identifier 220 . If the two codes 240 and 410 match, verification was successful; otherwise, at least one part of the transaction data 210 , human identifier. 220 , and unique code 240 was altered prior to execution of the verification process.
[0060] FIG. 9 illustrates the procedure 900 used by the system 100 to verify secure endorsed transactions, and to ensure that neither the transaction data nor the human identifier of the secure endorsed transaction has been altered. In the preferred embodiment, the procedure 900 is implemented in software executable by the microprocessor 140 .
[0061] As a first step, the microprocessor 140 receives the secure endorsed transaction (step 910 ). If the secure endorsed transaction was formatted by, for example, the formatter 310 , into a single whole representation of the secure endorsed transaction then it may be necessary for the microprocessor 140 to decompose the single whole representation of the secure endorsed transaction (step 920 ). Next, or after step 910 , the microprocessor 140 , using the unique code processor 230 , generates a new unique code from the transaction data and human identifier found in the secure endorsed transaction (step 930 ). This computed unique code is then compared with the unique code that was a part of the input secure endorsed transaction (step 940 ). If the two codes match, then the verification process confirmed that neither the transaction data nor the human identifier of the secure endorsed transaction has been altered. Otherwise, then one of the items was altered, in which case the appropriate error or signal is generated. (By further analysis of the secure endorsed transaction, it may also be possible to determine which of the transaction data and human identifier was altered. This information may be displayed as well. One way to determine which data item has been altered would be to add a checksum to each data item when they are initially created.)
[0062] (3) Creating Forge-Resistant, Tamper-Resistant Secure Endorsed Transactions
[0063] As more fully explained below, tamper-resistant secure endorsed transactions may be made forge-resistant by adding the digital signature endorsement of a second party, for example, the merchant making a credit card sale. See BSAFE, User's Manual, Version 2.1, p. 51, 1992, RSA Data Security, Inc.
[0064] FIG. 5 is an operational flow chart of a procedure for generating a digital signature for use in creating a forge-resistant secure endorsed transaction. A forge-resistant secure endorsed transaction is endorsed separately by both the individual associated with the human identifier and the second party to the transaction, i.e., the merchant. The properties essential to ensuring forge-resistancy are that with a public key system, one key can decrypt the other key's encrypted data and it is impossible to determine the key value of one key from examination of the other key. Further, encrypted data from one key can not be decrypted using the same key. The procedure illustrated in FIG. 5 uses public key cryptography of the type suggested by RSA Data Security, Inc., USA, and involves assigning a public key and private key pair to the merchant, in the credit card example, for use in encrypting and decrypting a digital signature associated with a secure endorsed transaction.
[0065] As shown in FIG. 5 , the transaction data 210 and human identifier 220 are provided to the unique code processor 230 along with a public key 510 associated with the merchant identified, for example, with the transaction data 210 . The unique code processor 230 generates a unique code 520 , which, like the unique code 240 , is unique to the inputs 210 , 220 , and 510 and is computationally infeasible to duplicate, is computationally infeasible to produce from a different combination of the inputs 210 , 220 , and 510 , and can be verified by code processor 230 as having been derived from the inputs 210 , 220 , and 510 .
[0066] The unique code 520 is then provided to a digital signature processor 540 along with a private key 530 corresponding to the public key 510 and owned by the merchant. The digital signature processor 540 generates a digital signature 550 , encrypting the unique code 550 using, as input, private key 530 , that guarantees the identity of the author of the secure transaction.
[0067] In the preferred implementation, the digital signature processor 540 is a software program produced by RSA Data Security, Inc., USA. It generates an output, known as a digital signature, using a private key 530 that can only be decrypted using the associated public key 510 . Other comparable software programs may be used without detracting from the scope of the present invention.
[0068] FIG. 6 is an operational flow chart of the procedure for generating a forge-resistant secure endorsed transaction using the digital signature 550 . First, it should be understood that the unique code 520 generated by the unique code processor 230 is a secure endorsement of the transaction by the human identified in the human identifier 220 , which was used by the processor 230 to generate the unique code 520 . The digital signature 550 provides a further level of security to the stored representation of the secure endorsed transaction by providing a unique identifier (private key 530 ) indicating endorsement of the transaction (specified in the transaction data 210 ) by the owner of the private key 530 (e.g., a merchant).
[0069] As shown in FIG. 6 , the transaction data 210 , human identifier 220 , public key 510 , and digital signature 550 are combined by a formatter 610 , and the resulting combination constitutes a secure endorsed transaction 620 that is both tamper-resistant and forge-resistant. In this case, the represented transaction has been endorsed by both the individual specified by the human identifier 220 and owner of the private key 530 used to generate the digital signature 550 .
[0070] The formatter 610 is a software program, for example, executed by the microprocessor 140 that combines the four inputs 210 , 220 , 510 , and 550 into a single representation, called a single whole representation of the tamper-resistant secure endorsed transaction 620 , which may be stored in the hard 160 , floppy disk 170 , or another storage device such as a WORM (write once read many) like a CD-ROM. The single whole representation of the tamper-resistant secure endorsed transaction 620 may also be stored on a smart card in a manner similar to the representation 320 described above with reference to FIG. 3 .
[0071] The single whole representation of tamper resistant secure endorsed transactions may be stored on a write-once, read-many times device as described earlier, however, this is no longer necessary. The digital signature 550 is encrypted which protects the identity to unauthorized individuals. As such, it is computationally infeasible for unauthorized individuals (individuals without knowledge of the private key 530 ) to replicate the secure endorsed transactions.
[0072] For credit card transactions, the unique code processor 230 and formatter 610 may be employed in POS equipment to allow merchants to store a plurality of single whole representations of secure endorsed transactions. In such cases, POS equipment would generate the transaction data and the human identifier would be captured at the POS as the cardholder, for example, signs the credit card receipt using a signature capture device or another identification input device 120 . The unique code processor 230 and formatter 610 would then generate the single whole representation of secure endorsed transactions that can be transmitted to the credit card processor, where the data is stored for a predetermined period of time.
[0073] FIG. 10 illustrates the procedure 1000 used by the system 100 to generate forge-resistant secure endorsed transactions. In the preferred embodiment, the procedure 1000 is implemented in software executable by the microprocessor 140 .
[0074] As a first step in creating a forge-resistant secure endorsed transaction, the microprocessor 140 would receive the transaction data itself as well as a human identifier, for example the buyer, for one party to the transaction as well as public key for the other party, for example the merchant, to the transaction (step 1010 ).
[0075] The transaction data and unique identifier are used to generate a unique code (step 1020 ), in the same manner as that discussed above with reference to FIG. 8 .
[0076] For the second endorsement, the second party to the transaction, the party associated with the public key (received in step 1010 ), the microprocessor 140 receives a private key, which corresponds to the public key and is maintained secret by the second party to the transaction. (step 1030 ). The unique code generated in step 1020 is then encrypted with the private key to generate a digital signature (step 1040 ).
[0077] The secure endorsed transaction may be stored in a database, with the component parts (transaction data, human identifier, unique code, and public key) in tables or the like (step 1060 ), as shown in the procedure 1000 by the broken line connecting steps 1040 and 1060 . Alternatively, before storing the secure endorsed transaction (step 1060 ), the secure endorsed transaction may also be combined into a single whole representation of the secure endorsed transaction. Using the formatter 610 , the microprocessor 140 would combine the individual components of the secure endorsed transaction into a single whole representation of the secure endorsed transaction (step 1050 ). The single whole representation of the secure endorsed transaction could then be stored as one data item representing the transaction (step 1060 ). One advantage of step 1050 is that it permits a subsequent transmission of the single whole representation of the secure endorsed transaction as one data item to, for example, a credit card transaction processor for approval of the transaction and/or long term storage.
[0078] (4) Verifying Forge-Resistant, Tamper-Resistant Secure Endorsed Transactions
[0079] FIG. 7 is an operational flow chart of the procedure used, for example, by microprocessor 140 , to verify a forge-resistant single whole representation of a secure endorsed transaction 620 . As shown, the verification procedure is substantially the reverse of the procedures outlined in FIGS. 5 and 6 for creating the secure endorsed transaction 620 . First, the formatter 610 is used to decompose the forge-resistant secure endorsed transaction 620 into the component parts: transaction data 210 , human identifier 220 , and public key 510 , and digital signature 550 . The decomposed transaction data 210 , human identifier 220 , and public key 510 are then processed by the unique code processor 230 to generate a new, computed unique code 720 . The public key 510 and digital signature 550 are processed by the digital signature processor 540 to decrypt the digital signature 550 and to determine the unique code 710 . The compare processor 420 is then used in the same fashion as that described above with reference to FIG. 4 , to compare the unique codes 710 and 720 to determine whether there is a match. If not, then the secure endorsed transaction 620 was tampered with prior to execution of the verification process. If the codes 710 and 720 match, the forge-resistant, tamper-resistant secure endorsed transaction 620 can be processed, for example, displayed, faxed, printed, etc. In the credit card example, the forge-resistant resistant tamper-resistant secure endorsed transaction 620 could be printed as a signed credit card receipt for visual inspection and verification by humans.
[0080] Those skilled in the art will recognize that various modifications may be made to the preferred embodiment without detracting from the scope of the present invention. For example, instead of using the formatter 610 to create a single whole representation of the secure endorsed transaction, the human identifier 220 , transaction data 210 , public key 510 , and digital signature 550 may be stored individually in a database, such as a relational database, located, for example, on the hard disk 160 . In this case, the verification process of FIG. 7 would also not involve the use of the formatter 610 . Instead, the human identifier 220 , transaction data 210 , public key 510 , and digital signature 550 are extracted from the database, processed by the unique code processor 230 to generate the new computed unique code 720 , which would then be compared by the compare processor 420 with the unique code 710 . If the compare processor 420 determines that the codes 710 and 720 match, then the forge-resistant, tamper-resistant secure endorsed transaction 620 (is original and) was not tampered with prior to verification. At this time, the secure endorsed transaction 620 can be processed, for example, displayed, faxed, printed, etc. In the credit card example, the tamper-resistant secure endorsed transaction 620 could be printed as a signed credit card receipt for visual inspection and verification by humans.
[0081] Yet another type of unique code may be generated by the unique code processor 230 by processing the human identifier 220 and transaction data 210 along with other data such as a time stamp specifying the time of the transaction. Furthermore, the secure endorsed transactions 320 or 620 can undergo further processing for additional security. For example, additional endorsements, such as a human identifier of a third party, may be appended to either of the transactions 320 or 620 to create secure endorsed transactions with multiple endorsements. In the preferred implementation, only appended endorsements specified in the transaction data 210 are permitted. Thus, before appending additional endorsements, the transaction data 210 is verified to determine whether the transaction data is unmodified and allows additional endorsements.
[0082] Additionally, secure endorsed transaction 620 may be verified by a separate certification authority that has an escrow copy of the public key 510 . In this way the public key 510 may be compared with an escrow copy of the public key assigned to the merchant to ensure that the specific merchant associated with the secure endorsed transaction 620 endorsed the transaction with its private key 530 . This step validates the authenticity of the merchant's public key by a third party and, thus, the authority of the secure endorsed transaction.
[0083] FIG. 11 illustrates the procedure 1100 used by the system 100 to verify secure endorsed transactions having digital signatures, and to ensure that neither the transaction data, the human identifier, nor the public key of the secure endorsed transaction has been altered. In the preferred embodiment, the procedure 1100 is implemented in software executable by the microprocessor 140 .
[0084] As a first step, the microprocessor 140 receives the secure endorsed transaction (step 1110 ). If the secure endorsed transaction was formatted by, for example, the formatter 310 , into a single whole representation of the secure endorsed transaction then it may be necessary for the microprocessor 140 to decompose the single whole representation of the secure endorsed transaction (step 1120 ). Note that in this case the secure endorsed transaction includes transaction data, a human identifier, a digital signature, and a public key.
[0085] Next, or after step 1110 , the microprocessor 140 , using the digital signature processor 540 , decrypts the digital signature of the secure endorsed transaction (step 1130 ). This step, which uses the public key portion of the secure endorsed transaction, provides the underlying unique code, the endorsement by human identifier) of one party to the transaction. Subsequently, or even simultaneously, three components of the secure endorsed transaction, i.e., public key, transaction data, and human identifier-, are processed by the unique code processor 230 to generate a unique code (step 1140 ). The two unique codes (one from step 1130 and the other from step 1140 ) are then compared (step 1150 ). If the two codes match then the verification process confirmed that neither the transaction data, the human identifier, nor the public key of the secure endorsed transaction has been altered. Otherwise, one of the items was altered, in which case the microprocessor 140 provides this information to the user via, for example, the display 180 . (By further analysis of the secure endorsed transaction, it may also be possible to determine which of the components, transaction data, human identifier, or public key was altered. This information may be displayed as well. One way to determine which data item has been altered would be to add a checksum to each data item when they are initially created.)
[0086] Throughout the above description of the preferred implementation, other implementations and changes to the preferred implementation were discussed. Thus, this invention in its broader aspects is therefore not limited to the specific details or representative methods shown and described. | To ensure the data corresponding to transactions has not been altered, a method and system are provided for generating secure endorsed transactions having transaction data representative of transactions and unique identifiers corresponding to parties endorsing the transactions. After receiving input, including transaction data and unique identifiers, unique codes are generated from the transaction data and unique identifiers. The unique codes constittue secure endorsements of the transaction data by the parties corresponding to the unique identifiers. | 6 |
This is a continuation of application Ser. No. 08/110,408, filed Aug. 20, 1993, now abandoned. Priority of the prior application is claimed pursuant to 35 USC §120.
BACKGROUND
Catalytic partial oxidation of hydrocarbons results in a gas product containing varying proportions of hydrogen, carbon monoxide, carbon dioxide, and other components. Steam reforming of hydrocarbons also results in a gas product of similar composition. The above gas products are hereafter referred to as "synthesis gas" and the present invention is related to its production by catalytic partial oxidation of hydrocarbons. In addition, whenever the process steps of partial oxidation or steam reforming are referred to, such steps refer to the catalytic partial oxidation or steam reforming of hydrocarbons.
Commercial production of hydrogen, ammonia, and methanol depends primarily on the use of synthesis gas produced by steam reforming combined with additional downstream process steps. The steam reforming reaction is an endothermic reaction and can be represented by the reaction of methane with water, as follows:
CH.sub.4 +H.sub.2 O→CO+3H.sub.2 ( 1)
Partial oxidation, on the other hand, is an exothermic reaction, which can be represented by the reaction of methane with oxygen, as follows:
CH.sub.4 +1/2O.sub.2 →CO+2H.sub.2 ( 2)
An undesirable secondary reaction may occur in catalytic partial oxidation, where oxygen may react with hydrogen to produce H 2 O, and subsequently form carbon dioxide.
The formation of carbon dioxide by catalytic partial oxidation and steam reforming occurs as a secondary reaction, to those indicated as (1) or (2). That secondary reaction is the exothermic water gas shift reaction, as follows:
CO+H.sub.2 O→CO.sub.2 +H.sub.2 ( 3)
The selectivities of catalytic partial oxidation and steam reforming to produce the various proportions of hydrogen, carbon monoxide, carbon dioxide, and water are controlled by several factors, but one of the most important of these factors is the choice of catalyst composition. Difficulties have arisen in the prior art in making such a choice economical. Typically, catalyst compositions have included precious metals and/or rare earths. The large volumes of expensive catalysts needed by prior art catalytic partial oxidation processes have placed those processes generally outside the limits of economic justification. However, for the following reasons, steam reforming remains a very expensive process for production of synthesis gas as well.
To produce synthesis gas by steam reforming, high temperature heat input is primarily required at two process steps. First, sufficient steam at a high temperature and high pressure must be generated for mixing with the hydrocarbon feedstock and, secondly, the steam reforming of the steam and hydrocarbon mixture must take place at relatively high temperatures and pressures through a bed of solid catalyst. The equipment needed for these two heat transfers at high temperature and high pressure is necessarily quite expensive. The equipment for the steam reforming step is also costly because it must be adapted to permit the changing the solid catalyst when that catalyst is spent or poisoned. Heat sources appropriate for the above two process steps are typically provided by fired heaters at high, continuing utility costs, also with high fluegas NOx production consequential to the high temperatures required in the furnace firebox.
Prior art has suggested that synthesis gas production by catalytic partial oxidation could overcome some of the above disadvantages and costs of steam reforming, as follows: "Production of Methanol from Hydrocarbonaceous Feedstock", PCT Application No. PCT/US89/05369 to Korchnak et al (International Publication No. WO 90/06282)(Korchnak et al '369) and "Production of Methanol from Hydrocarbonaceous Feedstock", PCT Application No. PCT/US89/05370 to Korchnak et al (International Publication No. WO 90/06297)(Korchnak et al '370) each describe an identical process for catalytic partial oxidation. The asserted advantages of Korchnak et al '369 and '370 are relatively independent of catalyst composition, i.e. in Korchnak et al '369 the authors state that " . . . partial oxidation reactions will be mass transfer controlled. Consequently, the reaction rate is relatively independent of catalyst activity, but dependent on surface area-to-volume ratio of the catalyst." (pp. 11-12). A monolith catalyst is used with or without metal addition to the surface of the monolith at space velocities of from 20,000-500,000 hr -1 . The suggested metal coatings of the monolith are selected from the exemplary list of palladium, platinum, rhodium, iridium, osmium, ruthenium, nickel, chromium, cobalt, cerium, lanthanum, and mixtures thereof in addition to metals of the groups IA, IIA, III, IV, VB, VIB, or VIIB. The catalyst surface area-to-volume ratio is in the range of 5-40 cm 2 /cm 3 . None of the detailed embodiments indicate any preference for metal coatings, specifically or in general. The feed mixture of methane and an oxygen-containing gas to the catalyst bed must be preheated to within 200° F. of the mixture's ignition temperature, but then the reaction proceeds autothermally. Steam is generally required in the feed mixture to suppress carbon formation on the catalyst. The conclusion reached by one skilled in the art is that Korchnak et al '369 and '370 attempt to solve the problem of high catalyst volumes and subsequent high costs in the use of catalytic partial oxidation by virtually eliminating the need for expensive metal coatings for the catalyst. The high catalyst volumes also require exceptional devices to attempt to evenly distribute the feed to the top of the catalyst bed, i.e., a number of tubes direct the flow of the feed gas to the top of the catalyst bed to reduce the severity of unstable operation through vapor phase combustion of the feed gas before it enters the catalyst bed.
U.S. Pat. No. 4,844,837 to Heck et al (Heck et al '837) discloses a catalytic partial oxidation method for methane using a monolith catalyst with platinum-palladium, palladium-rhodium, or platinum-rhodium coatings. There is a specific teaching "that the palladium-rhodium and platinum-rhodium combinations are rather ineffective for methane oxidation." (col. 8, 11. 28-30). The exclusion of rhodium from the monolith catalyst coating is highly preferred. The catalyst bed path required for the feed gas conversion described in this patent is calculated to be approximately one meter long.
U.S. Pat. No. 4,087,259 to Fujitani et al (Fujitani et al '259) describes a monolith catalyst with a rhodium coating to perform catalytic partial oxidation on gasoline and heavier petroleum fractions. The catalyst bed must be externally heated to maintain the reaction and the maximum space velocity is about 110,000 hr -1 .
SUMMARY OF THE INVENTION
The present invention uses a structurally specific monolith catalyst coated with rhodium or nickel to achieve dramatic increases in space velocity for catalytic partial oxidation. Such dramatic increases in space velocity necessarily result in lower required catalyst volume while retaining the advantages in selectivity and conversion of using the expensive rhodium or nickel monolith coatings. The space velocity range for the present invention using methane in a reactor near atmospheric pressure is between 120,000-12,000,000 hr -1 . Optimum space velocities have been determined to be about 800,000-1,000,000 hr -1 .
The use of the above catalyst to increase space velocity has produced several surprising results. The mass transfer characteristics of the catalyst are so improved that preheating of the feed gas is no longer necessary, i.e., the reaction is so rapid at the catalyst surface that heat from the partial oxidation exothermic reaction is transferred almost instantaneously to the feed gas entering the catalyst monolith. Although preheating the feed mixture of methane and oxygen-containing gas improves conversion and selectivity, ambient temperature feed gas mixtures (25° C.) entering the monolith maintained at an autothermal temperature of about 1000° F. result in conversion and carbon monoxide and hydrogen selectivities at greater than 95%. In addition, although generally required in Korchnak et al '369 and '370 to prevent carbon formation on the catalyst, steam addition is not needed or preferred.
The thickness of the catalyst monolith through which the feed gas mixture must pass is from 1 mm to 2 cm for the present invention. For Korchnak et al '369 and '370, the catalyst monolith required to achieve its objects are determined to be almost one meter thick. The difference in catalyst monolith volumes between the present invention and the prior art is several orders of magnitude apart. Such small catalyst volumes in the present invention eliminate radial temperature variation, i.e. hot spots, typical of all relatively thick catalyst beds.
Ceramic foam monoliths have been found, in the present invention, to create the superior mass transfer characteristics resulting in such dramatic increases in space velocity. Although metal gauzes or extrudates are effective as monoliths to achieve the objects of the present invention, ceramic foam monoliths are preferred where hydrogen production is the desired process use of the synthesis gas. Although the monolith geometries and orientation contribute to the enhanced mass transfer increasing space velocities for the present invention, the high space velocities themselves also add to maximizing the mass transfer coefficients at the monolith catalyst surfaces. Rhodium or nickel loadings on the monoliths of 1 to 15 percent as applied by washcoats is the preferred metals content range.
The reactor is started from ambient temperatures through the use of a mixture of light hydrocarbons or ammonia and air preheated to about 200° C. and then introduced to the monolith catalyst, or an appropriate temperature at which combustion will occur. After combustion has established a monolith catalyst temperature of near 1000° C., preheat and use of the mixture of light hydrocarbons or ammonia and air is stopped. The feed gas mixture of methane and an oxygen-containing gas is then fed to the monolith catalyst is begun at a mixture temperature of from 25° C. to 450° C.
The concept of Korchnak et al '369 and '370 is especially susceptible to unstable operation resulting from dominance of the vapor phase combustion reaction taking place in the preheated feed gas mixture. Such combustion reactions result in carbon dioxide and water as products, reducing the selectivity for hydrogen and carbon monoxide in partial oxidation processes with unstable operation. The elimination of high temperature preheating of the feed gas mixture in the present invention solves this problem. The feed gas mixture in the present invention does not require preheating to near its ignition temperature prior to introduction to the metal-coated catalyst.
In addition, because the catalyst volumes of the present invention are so small, they may be economically be contained in tubes. Thus, the feed gas distribution problems encountered in applying the concept of Korchnak et al '369 and '370 are eliminated for the present invention.
Although for ease in comparison with prior art, space velocities at standard conditions will be used to describe the present invention. It is well recognized in the art that residence time is the inverse of space velocity and that the disclosure of high space velocities equates to low residence times. The present invention has been demonstrated, for low pressure applications at a monolith catalyst temperature range from 850° C. to 1150° C., to perform optimally in the range of from 10 -2 to 10 -4 seconds.
DESCRIPTION OF THE DRAWINGS
FIG. 1A is a drawing of the reactor of the present invention with a cylindrical disk of monolith catalyst within a passage for a feed gas mixture of methane and an oxygen containing gas.
FIG. 1B is a schematic drawing of the adsorption, desorption, and surface reaction steps occurring on the monolith catalyst of the present invention.
FIG. 2 illustrates the results of (A) hydrogen and (B) carbon monoxide selectivities, (C) methane conversion, and (D) autothermal temperatures for a 50 ppi×7 mm, 11.6 wt % Pt monolith and an 80 ppi (pore per inch)×10 mm, 9.8 wt % Rh monolith as a function of a range of volume percent methane in the feed gas mixture composition and the feed gas mixture preheat temperatures for a total flow rate of 4 standard liters per minute (slpm) methane and air (as the oxygen-containing gas). Squares represent Rh, circles represent Pt, open symbols represent feed gas mixture temperature of 25° C., and filled symbols represent a feed gas mixture temperature of 460° C.
FIG. 3 illustrates the results of (A) hydrogen and (B) carbon monoxide selectivities, (C) methane conversion, and (D) autothermal temperatures as a function of a range of methane to oxygen ratios for an 80 ppi×10 mm, 9.8% Rh monolith using air (open symbols) and pure oxygen (closed symbols) as the oxygen-containing gas of the feed gas mixture at a total flow rate of 4 standard liters per minute (slpm) methane and oxygen-containing gas. Circles represent a feed gas preheat temperature of 25° C. Closed squares represent a feed gas preheat temperature of 300° C. Open squares represent a feed gas preheat temperature of 460° C.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1A-B, 2A-D, and 3A-D, the experimental apparatus developed for actual use of the present invention will now be discussed as a specific embodiment. For the purposes of this detailed description section, rhodium will be used as exemplary of similar results of the present invention to be obtained through the use of nickel as applied to monolith catalysts. The use of the term monolith catalyst is not intended as a specific limitation on catalyst structure to attain the objects of the present invention. As described above, metallic gauze or metal coated gauze may also be used efficiently. Extrudates may also be used if sufficient mass transfer across the boundary layer to the catalyst surface may be attained in a manner similar to that achieved by the ceramic foams.
A small, adiabatic reactor has been constructed to approximate the conditions of an industrial scale reactor. As constructed and shown in FIG. A, the reactor tube 100 is an insulated quartz tube with an 18 mm diameter. The reactor tube 100 contains a monolith catalyst disk 101 located so that the feed gas mixture 102 flows through the monolith catalyst disk 101. For this specific embodiment, the monolith catalyst disk 101 is 10 mm thick, cylindrical, and composed of alumina foam monolith (about 30-80 ppi, preferably 80 ppi) with rhodium deposited thereon by rhodium washcoats. In addition, the alumina foam monolith is an open, cellular, sponge-like structure cut into 17 mm cylinders. Generally, the rhodium content of the monolith catalyst disk 101 is between 0.1-20 weight percent. For this specific embodiment, rhodium content of the monolith catalyst disk is 9.8 weight percent.
Also for this specific embodiment, another metal coating is used for the monolith catalyst disk 101 so that its comparative performance in catalytic partial oxidation can be measured at high space velocities. Platinum is applied at 11.6 weight percent to a similar alumina foam monolith with 50 ppi and with a length of 7 mm and a diameter of 17 mm. That platinum coated monolith catalyst is subjected to feed gas mixture 102 compositions described above at appropriate conditions in monolith catalyst disk 101 so as to provide comparison with the results from use of the rhodium-coated monoliths.
For both the rhodium and platinum coated monolith catalyst disks, feed gas mixture 102 is comprised of either (1) light hydrocarbons or ammonia and an oxygen-containing gas for initial heating of monolith catalyst disk 101 as described above or (2) methane and an oxygen-containing gas (CH4 and O2 respectively in FIG. 1A). The feed gas mixture of type (2) is introduced to the reactor tube 100 at 25° C. or 460° C. during continuous operation after start-up. The temperature of the monolith catalyst disk 101 is within the range of 850°-1150° C. corresponding to the range of inlet temperatures for the feed gas mixture 102, i.e., 25°-460° C. The pressure at which the feed gas mixture 102 reacts with the monolith catalyst disk 101 is 1.4 atmospheres.
Feed gas mixture 102 was prepared using air and pure oxygen as the oxygen-containing gas. The results for use of pure oxygen as the oxygen-containing gas, as in the description of FIGS. 3A-D above, are reported only for a monolith catalyst disk 101 with 9.8 weight percent rhodium.
Now referring to FIGS. 2A-D, it is apparent that the Heck et al conclusion is incorrect that rhodium would yield less favorable results as a monolith catalyst than platinum. Using preheat temperature of 25° C. for feed gas mixture 102, the highest hydrogen and carbon monoxide selectivities (S H2 and S CO respectively) attainable for platinum are 0.43 and 0.89 respectively. The rhodium monolith catalyst hydrogen and carbon monoxide selectivities are 0.73 and 0.89 respectively. Selectivities are defined as: ##EQU1## where F i is the molar flow rate of species i.
It is also apparent with respect to FIGS. 2A-B that increasing the feed gas mixture 102 preheat temperature improves hydrogen and carbon dioxide selectivities for both rhodium and platinum coated monolith catalysts.
Referring now to FIG. 1B, note from the progress of reactants on monolith catalyst surface 104 that the measure of efficiency of the catalytic partial oxidation reaction in forming hydrogen and carbon monoxide depends (1) on the degree to which the methane and oxygen combine on the catalyst surface and the initial partial oxidation products (CO+O and 20H+2H to form carbon monoxide and hydrogen respectively) are removed before they further react to ultimately form carbon dioxide and water and (2) on the degree to which the monolith catalyst surface reactions take place over mere vapor phase combustion of the feed gas mixture which form carbon dioxide and water. The rapid mass transfer to and from monolith catalyst surface 104 is thus one of the most important aspects of the present invention. That rhodium has such superior efficiency to platinum in causing the partial oxidation reaction at the same space velocities is shown in FIGS. 2A-B by higher selectivities, in FIG. 2C by higher conversion of methane at equivalent methane concentrations in the feed gas mixture, and in FIG. 2D by such higher selectivities and methane conversions achieved at lower monolith catalyst temperatures.
The superior results shown in FIGS. 3A-D for the use of pure oxygen instead of air as the oxygen-containing gas are generally consistent with the similarly superior results using a preheat temperature of 460° C. instead of 25° C. The hydrogen and carbon monoxide selectivities of FIGS. 3A-B are improved for the use of pure oxygen over that of air. The amount of that improvement is, for a feed gas mixture preheat temperature of 25° C., approximately the same improvement shown in FIGS. 2A-B for increasing the preheat temperature from 25° C. to 460° C. Preheat temperatures of 300° C. for feed gas mixtures using pure oxygen as the oxygen-containing gas achieve hydrogen selectivities of up to 90 percent and carbon monoxide selectivities of up to 96 percent.
FIG. 3C presents data showing that the use of pure oxygen, as opposed to air, as an oxygen-containing gas improves methane conversion at equivalent methane to oxygen ratios by as much as 19 percent. FIG. 3D presents data showing that the use of pure oxygen, as opposed to air, as an oxygen-containing gas increases the monolith catalyst temperature by as much as 90° K., thus improving selectivities and methane conversion. The nitrogen in air is non-reacting and becomes a heat sink for the exothermic reactions in the monolith catalyst. To the extent that nitrogen is desirable in a downstream process or that an oxygen-rich gas not an economical choice for the oxygen-containing gas, air provided as the oxygen-containing gas for a feed gas mixture at 25° C. to the monolith catalyst accomplishes dramatic improvements over the prior art in catalyst volume reduction, hydrogen and carbon monoxide selectivities and methane conversion. | A process for the catalytic partial oxidation of methane in gas phase at very short residence time (800,000 to 12,000,000 hr -1 ) by contacting a gas stream containing methane and oxygen with a metal supported catalyst, such as platinum deposited on a ceramic monolith. | 2 |
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