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BACKGROUND
This invention relates to the construction of concrete slabs, and in particular to a support structure that is rapidly and efficiently put in place, and rapidly and efficiently removed in condition for re-use.
Concrete slab construction is, of course, a routine method for horizontally covering open areas between columns and girders affixed to the walls of buildings, parking garages, and so on. A typical procedure for installing these concrete "floors" is to first place shoring members across the columns and girders, with shoring support posts rising from the ground or the deck below to the concrete floor being installed. Corrugated decking is then placed on the surface of the shoring, with the edges of the decking overlapping flange edges on the permanent building wall, girders and columns. Post-tensioning steel cables are then placed over the decking to add strength to the resultant structure. Wet concrete is then poured over the corrugated decks. Alternately the post tensioning cables can be placed in the wet concrete as opposed to prior to the pouring. The concrete is then allowed to harden over a period of time. The supporting members can be so designed as to be removable after the concrete has hardened, simplifying concrete slab maintenance, and permitting re-use of the support structure on additional floors.
Various methods have been proposed for removable concrete slab support systems as is evident from the following examples. Keppler, in U.S. Pat. No. 1,707,226, discloses a supporting structure for concrete construction. This invention teaches a height adjustable shore 12 (centering post) cooperating with flanged 18 sheet metal members 16 (corrugated decking) connecting to height adjustable recesses 21 in soffit chairs. The invention notes (col. 2, lines 01-109), " a!fter the concrete has been sufficiently set, the shoring may be removed and the ledgers taken down, whereby the centering forms with the soffit chairs may be removed and permanent shoring mounted in place to engage the soffit plates or boards for continuing to support the concrete until it is firmly set with full strength". Lutz, in U.S. Pat. No. 3,059,738, discloses a removable concrete slab support wherein a portion of the support may be removed for the sake of economy prior to the concrete being fully set. An intermediate support 2 upheld by a prop 3 holds concrete slab supporting girders 1 and end supports 4 in place during the initial phase of setting wet concrete. Cornell, in U.S. Pat. No. 4,856,252, discloses a joist hanger 10 for removably securing a joist 38 during concrete slab construction. The joist hanger 10 has a box like metal configuration for securing the end of a suitable joist in the hanger. The joist hanger 10 has an extension section 18 for overlapping the top surface of a wall or girder 52, with a roll bar 22 acting as a pivot located a spaced distance below the extension section. After a concrete slab 34 is solidified on as suitable support 36, a sharp blow to the hanger causes it to pivot on roll bar 22, thereby releasing the hanger 10, joist, and support form the hardened concrete slab.
While these devices and methods disclose useful details for installation and removal of concrete slab support systems, they do not envision the efficiencies and conveniences inherent in the present invention. As will be more fully discussed below, this invention discloses a removable structure and method for supporting wet concrete during concrete slab construction without making use of vertical posts or shoring members which have to be supported down through the floors below to the ground. Accurate set up of corrugated decks is quickly accomplished to accept wet concrete. After the concrete has hardened all support members are quickly removed, ready for re-use as required.
It is therefore a primary object of the invention to provide a removable structure for supporting concrete slab construction that can be quickly put in place prior to the pouring of wet concrete, and quickly removed in re-usable condition after the concrete has hardened.
A further object of the invention is to eliminate the necessity for using vertical posts or shoring members which would have to be supported down through the floors below to the ground.
Another object of the invention is to permit the pouring and forming of a number of levels of concrete slabs in any desirable sequence.
Still another object of the invention is to provide for the plane of the shoring to always be automatically in the plane of the floor being formed.
Yet another object of the invention is to provide for rapid and convenient adjustment of the thickness of the concrete slab being formed.
A further object of the invention is to eliminate the necessity for permanently affixing structural support members to each other.
An additional object of the invention is to provide for most efficient placement of steel tendons within the concrete if post tensioning reinforcement concrete slab production is employed.
SUMMARY
These and other objects are obtained by the removable concrete slab construction and method of the present invention.
As has been noted above, in building construction, concrete floors are routinely installed horizontally between permanent building columns and girders supporting the walls of the building. Wet concrete is poured over usually temporary corrugated decking erected between the building girders and columns. Typically shoring posts are required, the posts extending vertically from the ground or a previously formed floor, in order to support the temporary shoring. For a variety of reasons, including economy in building construction and ease of maintenance of the finished building, removal of the corrugated decking, temporary shoring, and vertical post supports is desirable.
I have found that concrete floors can be constructed faster and more efficiently by eliminating any necessity for temporary vertical shoring supports. This permits forming floors at any convenient level without concerns regarding foundation supports for temporary shoring. In addition, my method provides for precise, accurate placement of temporary supports in that when all elements are positioned they are all in their proper location with minimal field measuring or adjusting.
For example, my method makes use of a right angle grid of shoring girders and shoring beams positioned between the permanent steelwork comprising the building columns and girders. The shoring girders and shoring beams can be constructed from conventional steel "I" beams with their ends modified with a latch device which allows insertion into a support for quick erection, adjustment, and removal. The purpose of the shoring girders is to provide support for the shoring beams, with the shoring beams providing the support for the corrugated decks. Conventional corrugated decking is employed with the exception that the ends of the decking to be supported by the building "I" beams have a bearing shoe added to the closed end of the corrugated decking to facilitate removal from the hardened concrete which will be more fully described below. The bearing shoe also prevents vertical displacement of the decking due to wind and other construction forces. The bearing shoe further allows exact bearing length of the decking over the building girder. Locking straps, placed at the opposite end of the decking to be supported by the shoring beams, complete the precise, accurately secured concrete slab, construction support system.
To construct a concrete floor, the end latches on the shoring girders are secured in pre-cut holes in the permanent building girders and/or columns, with the latches then being firmly secured so as to lock the shoring girders accurately in place. Similarly shoring beams are quickly secured at right angles to the shoring girders again making use of pre-cut holes in the shoring girders to which the end latches on the shoring beams are secured. Corrugated decking is then positioned perpendicular to and between the permanent girders and the shoring beams, with the bearing shoe end of the deck engaging a top flange edge of the permanent girder, and with the opposite end of the deck, overlapping the end of a second corrugated deck, and being held in position by locking straps, all supported by the shoring beams. The locking straps secure the open ends of the decking together, and also insure that the bearing shoe end of the deck is held firmly in place against movement caused by workers or the elements, as well as facilitating removal of the decking.
With the removable support structure now quickly, accurately, and firmly in place the wet concrete can be poured onto the surface of the corrugated decks with reinforcement rods inserted, if required. For those applications requiring post tensioning of the concrete, steel tendons can now be placed not only above the furrows of the decking, but also within the furrows. The more favored placement of steel tendons is possible here where the decking is secured perpendicular to the permanent girders, and not parallel thereto, which is typical in existing concrete slab construction. After the concrete has hardened sufficiently to be self supporting, the complete removable support structure is quickly removed, all components being ready for re-use. The latch mechanism on the shoring girders and shoring beams is simply retracted and the shoring girder or beam lowered on the threaded latch, retracted and moved to the right, permitting removal from below the decking. The bearing shoe construction now permits the decks to be quickly removed from the cured concrete by simply lowering the open ends and rocking them in a downward direction, which movement can be facilitated by making use of the locking straps which had previously been holding the decks in place. The shape of the shoe end allows the rocking motion to break the deck free of the hardened concrete.
Thus a new convenience in forming concrete slabs in buildings, parking garages, and the like is disclosed. A wet concrete support structure is described which is set in place with heretofore unobtainable speed and efficiency. Vertical support posts for the shoring are completely eliminated, permitting flooring levels to be constructed in any convenient sequence, while at the same time assuring that the shoring is always automatically in the plane of the floor being formed whether level or on a slope as in ramped floors. The perpendicular placement of the corrugated decks also permits placement of post tensioning steel tendons in the most favored position for strengthening the concrete. While the shoring girders and shoring beams have been described as preferably being modified steel "I" beams, it is to be noted that other shoring materials, including wood, plastic, and concrete, can be similarly employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a floor framing plan for one version of the invention.
FIG. 2 is a side elevational view of one version of the invention showing the bearing shoe modified end of a corrugated deck in contact with the top flange of a permanent building girder.
FIG. 3 is a side elevational schematic view of one version of the invention showing a strap securing the open ends of corrugated decks together.
FIG. 4A illustrates a similar version of the invention shown in FIG. 3, showing the strap further securing the corrugated decks to a top flange of a shoring beam.
FIG. 4B illustrates a similar version of the invention shown in FIGS. 3 and 4A, additionally showing a second strap securing a corrugated deck to a top flange of a shoring beam.
FIG. 4C illustrates a similar version of the invention shown in FIG. 3, showing a wooden platform placed on the top flange of a shoring beam for supporting the open ends of corrugated decks.
FIG. 5A is a side elevational view of one version of the invention illustrating the latch device on the end of a shoring girder engaging an opening in a permanent building girder.
FIG. 5B is a front view of the latch device of FIG. 5A prior to the latch being secured to the opening in the building girder.
FIG. 5C is a view taken along the line 5C of FIG. 5A showing the latch device as engaged in the hole in the building girder, the latch device being further temporarily secured to the building girder by means of threaded bolts.
FIG. 6 is a fragmentary top plan view of one version of the complete removable support structure of one version of the invention prior to the pouring of the wet concrete.
FIG. 7 is a schematic representation of an end portion of a concrete slab supported by the removable support structure of one version of the invention, illustrating the placement of post tensioning steel tendons within the furrows of the corrugated decks.
DETAILED DESCRIPTION
Turning now to the drawings wherein like structures having the same function are referred to with the same numerals, in FIG. 1 a floor framing plan 10 according to the invention is shown. Building columns 16 and girders 14 form the permanent structural elements for holding up the walls of a building, parking garage, and the like. Shoring girders 18 are shown schematically as spanning the horizontal distance between oppositely positioned building columns 16, or girders 14. Shoring beams 20 also shown schematically interconnect the shoring girders 18, and are spaced approximately equidistant and parallel to the girders 14, spanning between the opposed walls of the building. Reference numerals 14A and 18A show permanent and shoring girder members positioned between respective columns 16. Either can be used as the concrete support system design dictates. The shoring girder design, 18A, similar to shoring girder 18, has a suitable interface at each respective column to accept the latch portion of the latch engaging means as described generally hereinafter.
Corrugated decks 12 are shown positioned perpendicular to the permanent girders, with one end of each deck being supported by a shoring beam 20, and the other end being supported by the top flange of a permanent girder or a plate attached to the top of a column. The number of individual corrugated decks is obviously not limited to two to span the entire distance between building walls. Intermediate sections of decking can be employed depending on particular building dimensions. The shoring girders and shoring beams of the invention can be standard, I-beam, steel building girders modified to have a latch device at each end as will be fully described. These shoring support members can also be fabricated in wood, plastic, or concrete. Standard steel corrugated decks can be employed as support members of the invention, modified to have a closed end 22 (FIG. 2) with bearing shoe structure 23 as will be more fully discussed.
In FIG. 2 the end of the corrugated deck 12 that rests on the building girder 14 is shown. Concrete 30 has been poured and hardened on the surface of the corrugated deck. Typical decks employed are normally longer in length than in width and will be so considered for the discussion of this invention. The upraised end portion adjacent each furrow 25(see FIG. 6) at this end of the deck has a metal closure plate 22 to prevent passage of concrete through the open end to avoid encasement of the deck in concrete.
A bearing shoe 23 is affixed along the width of this end of the deck and secured to its underside. It contacts a top flange 15 of a building girder. The bearing shoe is comprised of four segments: a first segment 24 angled downward from the deck underside and contacting the top surface of the flange 15; a second segment 27 affixed to the underside of the deck immediately adjacent the closed end of the deck; a third segment 26 extending downward in a generally perpendicular direction to the second segment 27, to a point just about even with the underside of the flange; and a fourth segment 28 extending under the flange 15 at an obtuse angle to the third segment. The purpose of this bearing shoe structure is to provide a means for raising the front end of the corrugated deck 12 above the top surface of the top flange 15 of the building girder to facilitate the deck's subsequent removal; and to provide a means for grasping the extended lateral edge 15A of the flange so as to accurately secure the decking in position, ready to accept the pouring of the wet concrete and to prevent accidental dislodgement by workers or the elements.
The straps 34 (FIG. 3) employed at the open, opposite end of a deck, which will be fully explained hereinafter, further insure the accurate, rigid deployment of the corrugated decks. After the concrete has hardened, the deck itself is not encased by the concrete. In FIG. 2, the deck 12A shown in phantom, together with third and fourth bearing shoe segments, 26A, 28A, shown also in phantom, illustrate the ease with which the corrugated decking 12 can be removed after the concrete has hardened by simply pivoting about the contact surface between first segment 24 and the top of the flange while rocking the deck in a downward motion.
FIGS. 3-4C illustrate the strap securing method of the invention for connecting the open ends of the corrugated decks together where the decks 12, 13 overlap the shoring beams 20. In FIG. 3 a strap 34 is shown securing a first deck 12 in contact with the top surface of flange 21 of a shoring beam 20 to a second deck 13 extending in the opposite direction, and positioned at its open end directly over the first deck. The ends of the strap 34 are shown before they are bent in a downward direction as indicated by the arrows, thereby linking the two open ends 32A, 32B, of the two decks together. FIG. 4A shows the strap ends bent over the end of the respective deck sheet. Straps 34 can be made out of metal or plastic, sheet metal being preferred for its combination of strength and bendability. The straps are a few inches in width so as to fit into the furrows 25 of the corrugated decks, and of appropriate length so as to securely link the decks together. Usually one strap per deck pairing would be used, with the strap pre-hooked so as to engage the first deck 12 before the second deck unit is placed over the first deck. Before it is hammered in place to lock the decks together, the operator pulls on the strap so as to urge each deck 12, 13, away from supporting beam 20. This procedure keeps the bearing shoe end of the deck firmly and accurately secured on its girder flange 15 or column plate, and prevents dislodgement during construction due to workmen's activities, the elements, etc. The strap also assists in deck removal since the lower end of the strap can be grasped to pull the deck downward for removal.
Depending on particular building requirements different strap arrangements can be employed to provide additional security. For example, FIG. 4A illustrates bending a strap 34 to encompass not only the top and bottom positioned decks, but also the top flange 21 of shoring beam 20. FIG. 4B illustrates a double strap method: one strap 34A to secure the top deck to one side of a shoring beam top flange 21; and, a second strap 35 to secure the bottom deck to the opposite side of the same shoring beam top flange 21.
FIG. 4C illustrates utilizing a wooden platform 36 placed on the top level surface of a top flange 21 of a shoring beam for providing a platform for the placement of the open ends of the decking. The wood platform 36 comprises one or more piece(s) of plywood stacked on top of each other. The platform extends in width just beyond the top flange 21, thus providing a larger contact surface beneath the decking for a more stable condition. Further the wood is not as slippery as steel-on-steel when the decking is placed directly on the flange. Also, self-tapping screws can be used to secure corners, etc. of the decking down to the wood. Still further with the use of an appropriate thickness for the plywood piece(s), the height of the decking at the bearing shoe end 23 above the building girder top flange is compensated for at the shoring girders. As a result, the cooperating elements of the latching device disclosed hereinafter will lie essentially in the same plane. This facilitates the fabrication of substantially similar, support structure members, since the latch receiving openings are identically located in relation to the horizontal datum.
FIG. 5A illustrates the latch device employed by the invention for rapid erection, adjustment, and removal of the shoring support system. A latch enclosure 45, comprised of left and right side channels 46, a front plate 52, and a base plate 51, is connected at each end of the shoring girders and shoring beams. Alternately, flat plate members can be used instead of the channels 46. The channels or flat plates can be welded or bolted to the web of the shoring member. If bolted, the parts can be easily removed and reused on other shoring members.
A latch 40 together with its threaded latch column 42 is positioned within the enclosure with the latch 40 extending above the channels 46, with the latch column 42 extending through and below the base plate 51. The base plate has a slot 50 (shown in dotted lines--FIG. 5A) to facilitate movement of the latch 40--latch column 42 during erection or removal of the support structure. A nut 44 is threaded onto the end of the latch column protruding below the base plate to raise and lower the shoring beam or girder to the appropriate height and for securing the latch in place. In FIG. 5A a shoring girder 18 is shown being connected to a permanent building girder 14, using the latch device. This same structure is employed for connection of shoring girders to building columns as well, and for connection of the shoring beams 20 to the shoring girders.
As best seen in FIG. 5C, an opening 54 is pre-cut in the building girder 14 into which the latch 40 on the end of the shoring girder 18 is secured. The opening 54 is made wide enough to receive two such latches, one from each side. The latch is shaped to allow easy insertion into the support hole. Facing the opening 54 from the shoring girders side the latch is always positioned to the right side of the opening in order to minimize confusion by providing uniformity during the erection procedure; and, uniformity on the positioning of the temporary bolts (66--FIG. 5C). Referring to FIG. 1, this positioning of the latch to one side results in the skewing of the members as reflected by the centerlines, 55 and 57 of respective shoring girders and shoring beams, 18 and 20. The center or middle points, 55A and 57A, of each shoring member is in its true "center" position in the beam--girder support system.
FIG. 5B illustrates a front view of the latch enclosure 45, showing temporary bolt holes 56, 58 in the front plate 52 of the enclosure. FIG. 5C illustrates the latch 40 as being secured within the opening 54 in the building girder with threaded bolts 66 passing through bolt holes 56 and 58 in the enclosure front plate, and through two matching bolt holes 60, 62 in the building girders. The temporary bolts 66 engage the end plates of two opposing shoring girders and secure the assembly to the web of the support girder with nuts 64 threaded onto the bolts. The bolts 66 are a safety feature to prevent the shoring girders and shoring beams from dislodging and moving away from the permanent girders or from each other during the pour and subsequent concrete hardening. A bolt (not shown) is secured in a bolt hole 48 positioned directly behind the latch 40 when the latch is firmly secured in the building girder opening 54. The purpose of the bolt within bolt hole 48 is to prevent any dislodgement of the latch device during construction. Spacer plates 67 can be positioned between the channels 46 and the web of the shoring girder or beam.
These provide a means to adjust the lateral position of the latch 40 in relation to the opening 54 and the latch on the opposing shoring beam or girder.
The elements of the removable support structure 70 of the invention are shown in FIG. 6. Two sections of corrugated decking 12,13 are shown overlapping at a shoring beam 20. One of the decks spans the distance between the permanent building girders 14 and the shoring beam 20. The bearing shoe 23 at the first end of the deck envelopes the top near edge of the top flange 15 of the building girder 14. The front section 24 of the bearing shoe 23 raises the deck a spaced distance above the surface of the building girder top flange 15. The second end of the deck is shown supported by the top flange 21 of the shoring beam 20, being overlapped by a second deck 13. The two decks are secured together by a strap 34 as best seen in FIG. 3. The shoring beam 20 itself is secured at each end to two shoring girders 18, the shoring beam being positioned at a right angle to the shoring girders, with the shoring girders positioned perpendicular to, and spanning the distance between, the permanent building girders 14 and columns 16. They are similarly secured at their ends to the permanent girders and columns.
FIG. 7 illustrates a unique advantage of the structure and method of the invention for those applications in which steel tendons 72 are employed to post tension a concrete slab. When corrugated decks are placed parallel to the permanent building girders and columns, as is typically the case in prior technology, the steel tendons, which need to be placed perpendicular to the permanent girders and columns, can only be placed above the furrows of the decks. Since the present invention calls for the placement of the decks perpendicular to the building girders and columns, it is now possible to place steel tendons within the furrows in the decking thus providing the same strength with a thinner deck| The removable support structure of the present invention utilizing the latch engaging means provides a technique for enhancing the post- tensioning ability of the system. Referring to FIG. 1, by way of illustration a pair of shoring girders 14A and 18A are shown disposed between a respective pair of building columns 16. Permanent girders 14 are secured to the columns 16 and run perpendicular to the shoring girders. The ends of intermediary shoring girder 18 engage the web portions of respective girders 14 employing the latching device described. Intermediary, shoring beams 20 are disposed between 14A and 18, and between 18 and 18A. They are removably secured to the shoring girders, again, by means of the latch device set out above. Disposed between the permanent girders 14 and the shoring beams 20 are deck members 12 and 13 which span the entire area. The vertical distance between the top flange of the shoring beams 20 and the underside of the deck members 12 and 13, can be varied by adjusting the nut 44 securing the latch column 42 on the latch mechanism at each end of a typical shoulder beam 20. Thus the vertical distance at the shoring beams can be made greater than the vertical spacing of the shoe end of the deck plates at respective girders 14, thus increasing the thickness of the concrete deck at the center, above the shoring beams 20. As such, when the concrete hardens, the post-tensioning effect is enhanced thereby increasing the structural strength of the deck. The thickness at the shoring beams 20 can also be reduced using additional layers of plywood or raising the location of the latch support openings 54 in the shoring girders 14A, 18, 18A, etc.
After the wet concrete has been poured and then permitted to harden, and the post-tensioning effected, the weight of the system is now supported by the permanent structure. The removable support structure 70 is now taken down with heretofore unobtainable ease and convenience, ready for re-use. The temporary bolts 66 are removed from the bolt holes in the beam, building girder or column and the front plate of the latch enclosure. The nut 44 securing the latch column 42 within the opening 54 in the building girder, beam or column, is simply lowered and the bolt within bolt hole 48 is removed. The shoring girder or beam is raised slightly to free the latch. The shoring girder or beam is now free to be moved to the right or left for easy removal. Similar actions at each shoring girder or beam, latch mechanism release these support structures for rapid removal. The straps at the open end of the decks can now be grasped and pulled downward to facilitate the downward motion of the bearing shoes 23 at the building girder or column supported ends of the decks. This motion causes the bearing shoes to break clear of the concrete at the supported end of the deck, with the complete corrugated deck now being free of the concrete slab, in condition for re-use.
While the present invention has been disclosed in connection with versions shown and described in detail, various modifications and improvements will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be limited only by the following claims. | A removable support structure for concrete slab fabrication is described. A latch device secured to the ends of both shoring girders and shoring beams permits rapid and accurate placement of the shoring support across a span to be structured in concrete. Vertical shoring posts and supports are eliminated, with the added advantage of the plane of the shoring always being automatically in the plane of the floor being formed. Bearing shoes on the ends of corrugated deck members, secured to building girders, cooperating with straps at their other ends, accurately and securely positions the corrugated decking in place. After the concrete has hardened, the entire support structure, including the shoring girders, shoring beams, and corrugated deck members, are rapidly and efficiently removed, ready for re-use. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/648,965, filed Feb. 1, 2005. The entire contents of that provisional application are incorporated herein by reference.
BACKGROUND & SUMMARY
[0002] As both the equity and fixed income markets have experienced lackluster returns, growth in alternative investments as an asset class has exploded. With this growth investors are looking for smart ways to invest: principal protection, tax efficiency, reduced income volatility, favorable capital treatment, etc.
[0003] The present invention relates to a principally protected hedge fund linked municipal note for clients wanting to avoid phantom income tax and recognize long term capital gains/losses.
[0004] In general terms, the invention is directed to providing an investor with a note that has two main components: a municipal (i.e., tax-free) bond and a (preferably European) hedge fund option. As is known in the art, a European option may be exercised only at the expiry date of the option, i.e. at a single pre-defined point in time, as opposed to an American option, which may be exercised at any time before the expiry date.
[0005] In one aspect, the invention comprises a method comprising: (1) selling a note to an investor for a specified amount; and (2) using proceeds from selling the note to purchase (a) one or more zero coupon municipal bonds, and (b) an option on at least one of the group comprising: a hedge fund, a fund of funds, and a hedge fund index; wherein the note entitles the investor to substantially all of the returns on the one or more bonds and on the option, wherein the one or more bonds are configured to provide a return substantially equal to the specified amount, and wherein the option is a European option.
[0006] In various embodiments: (a) the option is a variable option; (b) the one or more zero coupon municipal bonds mature on a specified maturity date, and the option is exercisable on a date within 12 months of the specified maturity date; (c) the variable option is a periodic reset call option; and (d) a sum of an amount paid to purchase the one or more zero coupon municipal bonds and an amount paid to purchase the option is equal to the specified amount, less commercially reasonable fees.
[0007] Some embodiments of the present invention comprise computer components and computer-implemented steps that will be apparent to those skilled in the art. For example, calculations and communications can be performed electronically, and agreements can be composed, transmitted and executed electronically.
[0008] For ease of exposition, not every step or element of the present invention is described herein as part of a computer system, but those skilled in the art will recognize that each step or element may have a corresponding computer system or software component. Such computer system and/or software components are therefore enabled by describing their corresponding steps or elements (that is, their functionality), and are within the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0010] In one embodiment, a 7.5 year note, priced at par ($100), can be viewed in two parts: a zero coupon municipal bond and a leveraged hedge fund investment (i.e., an option). The zero coupon bond, worth approximately $80 (in this example), accretes to par ($100), guaranteeing principal.
[0011] The invention advantageously uses a hedge fund option instead of a direct hedge fund investment. Direct hedge fund investments subject investors to short term gains/losses due to the trading nature of the fund, yet the investor does not reap actual benefits until her stake in the fund is sold.
[0012] In a preferred embodiment, the remaining $20 of the note purchases an option on a fund of funds. Since the $20 purchases an option, the investor is not subject to short term gains/losses (which are taxed at the same rate as ordinary income) but rather long term capital gains/losses (which are taxed at a lower rate than ordinary income) at the expiration of the option.
[0013] The option preferably is a variable option—that is, it represents a variable interest in the fund of funds. Initially the note has 100% participation in the performance of the fund of funds (see Notional Amount in Appendix A). On a monthly basis, the participation in the fund of fund return will be adjusted based upon the performance of the fund of funds and the accretion rate charged by a note issuer. Positive performance of the fund of funds may result in an increased participation in the fund of funds (i.e., additional leverage provided by the note issuer). Negative performance of the fund of funds may result in reduced participation in the fund of funds. This feature is often referred to as a Periodic Reset Option (see “Option Adjustment” in Appendix A).
[0014] Table A below illustrates the possible outcomes of this note at maturity.
TABLE A Return Tax implication <$100 N/A* since the zero accretes to $100 $100 to $120 Tax loss since the purchase price of the option was not recouped >$120 Long term capital gain *N/A assuming that the municipal note does not default.
[0015] As depicted in FIG. 1 , in a preferred embodiment a 7.5 year note 100 is sold by a note issuer to an investor. The note entitles the investor to receive the proceeds (less a fee charged by the issuer) from two investments: a tax-free municipal bond 110 and a hedge fund option 120 . Preferably, approximately 80% of the funds received for the note are invested in one or more (tax-free) zero coupon municipal bonds, and approximately 20% is used to purchase a hedge fund option (preferably an option on a 100% participation—that is, five times the value of the option). At the end of the 7.5 year period, the investor receives the return 140 on the mature bond (approximately 100% of the price of the note) and the option is either exercised or expires, resulting in a gain or loss 160 .
[0016] An important feature of at least one embodiment is variability of the participation related to the option. As stated above, for each $20 invested in the option, the holder is given an initial participation in a fund of funds of $100. However (see Appendix A), on a monthly or other periodic basis, that participation may be adjusted, based on the performance of the fund of funds. Appendix A provides exemplary adjustment formulas, but these are intended to be only exemplary—those skilled in the art will recognize that various other adjustment formulas could be used without departing from the scope of the present invention.
[0017] An exemplary INDEX (see Appendix A) used in an embodiment of the invention is the Dow Jones Hedge Fund Balanced Portfolio Index.
[0018] In an alternate embodiment, certificates (due, say, October 2012) are issued by a trust established pursuant to a series Trust Agreement between a Depositor and a Trustee. The Trust Agreement incorporates the standard terms for trust agreements. Each certificate represents a fractional undivided ownership interest in the Trust.
[0019] The principal assets of the Trust are (i)(a) a (for example) $2,950,000 principal amount of a Zero Coupon Custodial Receipt (see Appendix B) due Jul. 1, 2012, issued by a Custodial Receipt Agent, and (b) a Final Interest Payment Custodial Receipt (see Appendix B) issued by the Custodial Receipt Agent; and (ii) the rights of the Trust under a 1992 ISDA Master Agreement (Multicurrency—Cross Border) (a Periodic Reset Call Option Agreement—see Appendix C) with a Call Option Seller pursuant to which, in exchange for a Call Option Premium received from the Trust on an Effective Date, the Call Option Seller pays each Call Option Settlement Amount, if any, on any Call Option Settlement Date. The amount of a Call Option Settlement Amount is determined based on performance of an Index (e.g., the Dow Jones Hedge Fund Balanced Portfolio Index). Each certificate entitles the holder to a pro rata share of distributions from the Trust.
[0020] While particular elements, embodiments, and applications of the present invention have been shown and described, it should be understood that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teaching. The appended claims are intended to cover all such modifications that come within the spirit and scope of the invention. This description does not constitute and is not intended to provide tax or accounting advice. Those seeking to implement any aspect of the described invention should seek the advice of their own accounting and legal advisors as to the treatment of proposed implementations in the context of specific circumstances.
APPENDIX A PRINCIPAL PROTECTED [INDEX] LINKED NOTE USD DENOMINATED PRINCIPAL PROTECTED NOTE LINKED TO THE [INDEX] Note Issuer: Special Purpose Issuer [Delaware business trust] Principal USD 100,000,000 Amount: Denominations: USD 1,000 - minimum purchase of USD 100,000 Maturity Date: Oct. 31, 2012, subject to adjustment in accordance with the Following Business Day Convention, an Early Redemption Event or if the Valuation Date is postponed. Maturity Value: 100% + Cash Settlement Amount Index: [INDEX description] Index Level: INDEX value as of Apr. 27, 2005. Trade Date: TBD Issue Date: Apr. 27, 2005 Deposited Assets: USD 100,000,000 Municipal Certificate maturing Jul. 1, 2012. USD 100,000,000 Notional amount of the Index Option. Municipal A certificate representing the right to receive the principal paid on Certificate: AAA/Aaa rated municipal bonds on the Jul. 1, 2012. Index Option: Cash settled option contract between the Note Issuer and the Option Seller under which the Note Issuer will pay the Premium and the Option Seller will pay the Cash Settlement Amount, as described below. Early Redemption Upon the occurrence of an Early Redemption Event, the Notes will Events: be redeemed on the Early Redemption Date at a price equal to the Early Redemption Amount. An “Early Redemption Event” means the occurrence of any of the following events, as determined by the Calculation Agent: 1. The occurrence of an Early Termination Event with respect to the Index Option; or 2. The Deposited Bonds default or are deemed taxable. If an Early Redemption Event occurs, the Note Issuer will send notice of early redemption to Note holders, the Notes will be redeemed as of the Early Redemption Date and the Note Issuer will pay to Note holders on the Early Redemption Date the Early Redemption Amount. Early Redemption An amount equal to the market value of the Municipal Certificate, as Amount: determined by the Calculation Agent, plus the Early Termination Amount. Early Redemption The date provided in the Note Issuer's notice of early redemption to Date: the Note holders, provided that such date shall be no later than 60 calendar days following the day the Calculation Agent determines that an Early Redemption Event has occurred. Municipal Certificate Terms Certificate USD 100,000,000 Payment Amount: Certificate Jul. 1, 2012 Payment Date: Municipal A trust which holds the Deposited Municipal Bonds and issues the Trust: Municipal Certificate to the Note Issuer. The Municipal Certificate represents the right to receive an amount of principal paid on the Deposited Bonds equal to the Certificate Payment Amount. Deposited Municipal bonds in an aggregate principal amount no greater than Bonds: USD 100,000,000 which mature no later than Certificate Payment Date and are rated AAA/Aaa at the time such bonds are deposited into the municipal trust. Depositor: [Depositor] Substitution of The Depositor shall have the right to deposit additional municipal Deposited bonds into the Municipal Trust and withdraw a like principal amount Bonds: so long as the delivered bonds mature no later than Oct. 31, 2012 and are rated at the time of substitution AAA/Aaa. Index Option Terms Option Seller: [ ] Option Style: European (exercisable only on the Exercise Date) Exercise Date: [Jan. 1, 2012], subject to adjustment in accordance with the Following Business Day Convention, an Early Termination Event or if the Valuation Date is postponed. Valuation The Valuation Date for automatic exercise of the Index Option on the Date: Exercise Date shall be the last Calendar day of the month prior to the Exercise Date, provided that if such date is not an Index Business Day, the Calculation Agent shall refer to the Index Level for the immediately preceding Index Business Day. in determining the Index Level for such Valuation Date; provided further that if the Calculation Agent determines that a Market Disruption Event has occurred on such day, such Valuation Date shall be the next succeeding end-of-month calendar day upon which no Market Disruption Event occurs. If a Valuation Date is postponed due to a Market Disruption Event or otherwise (such Valuation Date, a “Postponed Valuation Date”), the subsequent Valuation Date shall be the last calendar day of the month after the month in which the Postponed Valuation Date occurs. Assuming no Market Disruption Events occur, the Valuation Date is scheduled to be Sep. 28, 2011 The Valuation Date for an Early Termination Event shall be the last business day of the month that ends after the [30 th ] calendar day after the Option Seller has sent its notice of early termination, provided that if such date is not an Index Business Date, the next following Index Business Date. Expiration 10:00 a.m., New York time Time: Units: Units (each, a “Unit”) representing interests in the [Index] (the “Index”). Hedge Shares: Shares (each, a “Share”) representing interests in the [Index Tracker] (the “Fund”). Number of Initially [100,000] Units: Upon the occurrence of a Downward Adjustment Event, the Number of Units shall be reduced on the relevant Adjustment Date, by an amount equal to the Adjustment Amount divided by the Index Level for the relevant Index Business Day for a hypothetical investor that initiated a redemption of its Hedge Shares on the Observation Date. If a Downward Adjustment Event results in more than one Adjustment Date, the Number of Units shall be reduced on such dates as determined by the Calculation Agent. Upon the occurrence of an Upward Adjustment Event, the Number of Units shall be increased on the relevant Adjustment Date, by an amount equal to the Adjustment Amount divided by the Index Level for the relevant Index Business Day for a hypothetical investor that initiated a subscription for the Hedge Shares on the Observation Date. Option [USD 20,000,000] in cash (20% of the initial Notional Amount) Premium: Notional The product of the Index Value times the Number of Units, as Amount: determined by the Calculation Agent. Initially, the Notional Amount will equal [USD 100,000,000] and will be adjusted as described in “Option Adjustment”. Strike Price: Initially, [USD 80,000,000] (80% of the Notional Amount), accreting daily at the Floating Rate plus the Spread on the basis of Act/360, compounded monthly from the Effective Date to but not including the Payment Date, and adjusted as described in “Option Adjustment”. Floating Rate: USD-LIBOR-BBA with a designated maturity of 1 month, determined two Business Days prior to the first of each month commencing with the Effective Date. Spread: [1.75] percent Adjustment On any Observation Date, Ratio: Adjustment Ratio = Notional Amount/(Notional Amount − Strike Price) For purposes of determining the Adjustment Ratio on any Observation Date, the Calculation Agent may use the lesser of the last estimated Index value as provided by the Administrator of the Hedge Shares or the last available Index value as published. Solely for purposes of determining the Adjustment Ratio between an Observation Date and the corresponding Adjustment Date, the Calculation Agent shall treat the Notional Amount and the Strike Price as if each had been adjusted by the Adjustment Amount on such Observation Date. Initial 5.0 as of the Effective Date Adjustment Ratio: Target 5.0 Adjustment Ratio: Maximum 6.0 Adjustment Ratio: Minimum 4.0 Adjustment Ratio: Option If on any Observation Date the Calculation Agent determines that the Adjustment: then-current Adjustment Ratio exceeds the Maximum Adjustment Ratio (a “Downward Adjustment Event”), the Strike Price and the Notional Amount shall be reduced by the same Adjustment Amount on the relevant Adjustment Date (a “Downward Adjustment”). The Calculation Agent shall determine the Adjustment Amount on the Observation Date pursuant to the following formula: Adjustment Amount = Notional Amount on the Observation Date − ((Notional Amount on the Observation Date − Strike Price on the Observation Date) × Target Adjustment Ratio) In the event that the Strike Price is reduced to or below the Minimum Strike Price, the Index Option will terminate early pursuant to the “Early Termination Events” section. If on any Observation Date the Calculation Agent determines that the then-current Adjustment Ratio is below the Minimum Adjustment Ratio (an “Upward Adjustment Event”), the Strike Price and the Notional Amount shall be increased by the same Adjustment Amount on the relevant Adjustment Date (an “Upward Adjustment”). The Calculation Agent shall determine the Adjustment Amount on the Observation Date pursuant to the following formula: Adjustment Amount = ((Notional Amount on the Observation Date − Strike Price on the Observation Date) × Target Adjustment Ratio) − Notional Amount on the Observation Date However, under no circumstances shall the Strike Price be increased above the Maximum Strike Price pursuant to an Upward Adjustment. If the Strike Price is adjusted such that it equals the Maximum Strike Price, the Adjustment Amount for purposes of calculating the Number of Units and Notional Amount shall be the amount by which the Strike Price is actually adjusted. Minimum USD 25,000,000 Strike Price: Maximum USD 160,000,000 Strike Price: Adjustment For Downward Adjustments: Dates: The day that a hypothetical investor in the Hedge Shares would receive proceeds with respect to redeeming Hedge Shares if it initiated such redemption on the applicable Observation Date, as determined by the Calculation Agent. If such proceeds would be received on more than one date, the Adjustment Dates will be each date that such proceeds would actually be received, with the Number of Units, Notional Amount and Strike Price adjusted on such dates as determined by the Calculation Agent. For Upward Adjustments: The day that a hypothetical investor in the Hedge Shares would deliver proceeds with respect to subscribing for Hedge Shares if it initiated such subscription on the applicable Observation Date, as determined by the Calculation Agent. Observation Dates on which the Index Level is published, commencing with May 2, Dates: 2005 and ending with Aug. 31, 2012 Index Business Any day (a) as of which the Index Level is published and (b) on which a Days: Market Disruption Event has not occurred. Cash The Note Issuer shall receive on the Payment Date the following Settlement amount in USD: Amount: Max [Notional Amount f − Strike Price f ; 0] Where “Notional Amount f ” means the Notional Amount as of the Valuation Date “Strike Price f ” means the Strike Price as of the Payment Date Payment Date: The fifth Business Day after the day that a hypothetical investor in the Hedge Shares would receive proceeds with respect to redeeming Hedge Shares if the NAV Date for such redemption were the Valuation Date, as determined by the Calculation Agent. If such proceeds would be received on more than one date, the Payment Dates will be the fifth Business Day after each date that such proceeds would actually be received, with the Cash Settlement Amount proportionately paid on such dates as determined by the Calculation Agent. Early An “Early Termination Event” means the occurrence of any of the Termination following events, as determined by the Calculation Agent in its sole Events: discretion: 1. The Index Sponsor fails to comply with the index methodology or any of the funds underlying the Index fails to comply with the asset allocation policy, each as represented by the Index Sponsor to the Calculation Agent, unless such failure is waived by the Calculation Agent; 2. The Index Sponsor fails to provide the Calculation Agent with information the Calculation Agent deems necessary to determine compliance with the index methodology or asset allocation policy in a timely manner; 3. The Index Sponsor announces that it will make a material change in the formula for or method of calculating that Index or in any other way materially modifies the Index; 4. The Index Sponsor fails to calculate and publish the Index Level for more than 5 consecutive Business Days; 5. The Index is terminated; 6. The Index, the Index Sponsor, the Administrator (defined below) or the Investment Manager (defined below) materially breaches any applicable law or regulation or any regulatory or governmental authority brings an administrative or judicial proceeding or commences an inquiry against the Index Sponsor, the Administrator or the Investment Manager alleging any misconduct or wrongdoing; 7. The annualized volatility of the Index Level exceeds 15% for a six-month rolling window; 8. There is a change in tax law, tax regulations or the interpretation of tax law or tax regulations by any court, tribunal or regulatory authority which could have an adverse economic impact for the Note Issuer with respect to the Notes or its hedge (as defined below); 9. The occurrence of a Hedging Disruption Event that is not waived by the Note Issuer. A “Hedging Disruption Event” means that the Note Issuer, or any affiliate, is unable, after using commercially reasonable efforts, to hedge or would incur a materially increased amount of tax, duty, expense or fee, as compared to its costs and anticipated costs as of the Trade Date, to hedge. As used in this termsheet, “hedge” means: (A) acquire, establish, re-establish, substitute, maintain, unwind or dispose of any transaction(s) or asset(s) the Note Issuer deems necessary to hedge the risk of entering into and performing its obligations with respect to the Index Option or (B) to realize, recover or remit the proceeds of any such transaction(s) or asset(s). 10. The administrator or investment manager of a transaction or asset deemed necessary by the Note Issuer, or any affiliate, to hedge (the “Administrator” and the “Investment Manager”, respectively) ceases to act in the capacity of administrator or investment manager and a replacement administrator or investment manager is not appointed immediately and/or is not acceptable to the Calculation Agent. 11. The Index Level is no longer calculated in USD; 12. Index Option Seller is unable to purchase or sell the Hedge Shares on at least a monthly basis; If an Early Termination Event occurs, the Option Seller will send notice of early termination to the Note Issuer, the Index Option shall be cancelled as of the Valuation Date and the Note Issuer shall be entitled to an amount equal to the Cash Settlement Amount, as determined by the Calculation Agent, less the cost to the Option Seller, or any affiliate, of unwinding any related hedging arrangements, as determined by the Option Seller. Early An amount equal to the market value of the Option as of the last Termination calendar day of the month immediately preceding the month in which Amount: the Early Termination Date occurs, as determined by the Calculation Agent, less the cost to the Option Seller, or any affiliate, of unwinding any related hedging arrangements, as determined by the Option Seller; provided that if the Calculation Agent determines that a Market Disruption Event has occurred on such day, the Calculation Agent shall determine the Early Termination Amount with reference to the next succeeding end-of-month calendar day upon which no Market Disruption Event occurs.. In determining the Early Termination Amount, the Calculation Agent may, but need not, consider any relevant information, including, without limitation, information consisting of relevant market data in the relevant market including, without limitation, relevant rates, prices, yields, volatilities, spreads, correlations or other relevant market data from internal sources (including any affiliates of the Calculation Agent) or otherwise. The “Early Termination Amount” shall be determined by the Calculation Agent. Early The date provided in the Option Seller's notice of early termination to Termination the Option Buyer. Date: Market Market Disruption Event means, on any day, any event that disrupts or Disruption impairs the ability of the Issuer, or any affiliate, to obtain values for Event: such day for any transaction or asset deemed necessary by the Issuer, or any affiliate, to hedge, at which value the Issuer, or any affiliate, could subsequently unwind or dispose of such transaction or asset. Business Days New York, London Calculation [ ], whose determinations and calculations shall be binding absent Agent: manifest error.
[0021]
APPENDIX B
Zero Coupon Custodial Receipt:
CUSIP:
[ ].
Original Aggregate Principal
$2,950,000.
Amount Outstanding:
Issue Date:
Apr. 27, 2005.
Maturity Date:
Jul. 1, 2012.
Initial Deposit Price:
80%.
Original Issue Price:
80%.
Adjusted Issue Price:
80%.
Initial Market Value:
Initial Deposit Price multiplied by the Original
Aggregate Principal Amount Outstanding.
Interest Rate per Annum:
No interest will be paid on the Zero Coupon
Custodial Receipt.
Interest Payment Dates:
No interest will be paid on the Zero Coupon
Custodial Receipt.
Redemptions:
See details of Custodial Receipt Underlying
Bonds in Exhibit A attached hereto.
Specified Private Activity Bond
No.
(Subject to AMT):
Pre-Refunded Bonds:
No.
Principal Credit Source:
The governmental issuer of the Custodial Receipt
Underlying Bonds described in Exhibit A attached
hereto or, if any other Principal Credit Source is
identified in such Exhibit A hereto, such other
Principal Credit Source.
Principal:
Principal will be paid on the Maturity Date.
Final Interest Payment Custodial Receipt:
CUSIP:
Notional Principal Amount:
$50,000.
Issue Date:
Apr. 27, 2005.
Maturity Date:
Jul. 1, 2012.
Initial Deposit Price:
80%.
Original Issue Price:
80%.
Adjusted Issue Price:
80%.
Initial Market Value:
Initial Deposit Price multiplied by the Original
Aggregate Principal Amount Outstanding.
Yield per Annum:
3.1331% (331.31 bps per annum) yield.
Interest Payment Date:
Jul. 1, 2012.
Redemptions:
See details of Custodial Receipt Underlying Bonds
in Exhibit A attached hereto.
Specified Private Activity Bond
No.
(Subject to AMT):
Pre-Refunded Bonds:
No.
Principal Credit Source:
The governmental issuer of the Custodial Receipt
Underlying Bonds described in Exhibit A attached
hereto or, if any other Principal Credit Source is
identified in such Exhibit A hereto, such other
Principal Credit Source.
Principal:
No principal will be paid on the Final Interest
Payment Custodial Receipt.
Underlying Securities
No transfer of a Custodial Receipt (including
Transfer Restrictions:
transfers of beneficial ownership not registered on
the books of the Custodian and over which the
Custodian has no direct control) will be made
unless the transferor obtains from the transferee
holder or beneficial owner of such Custodial
Receipt (and presents a copy of the same to the
Depositor) a letter describing the nature of the
transferee and its holding of such Custodial
Receipt and also certifying to the effect that: (i) the
transferee is either (a) an “Accredited Investor,”
as that term is defined in Rule 501(a) of Regulation
D under the Securities Act, is purchasing for its
own account and for investment purposes only and
has such knowledge and experience in financial or
business matters that it is capable of evaluating the
merits and risk of an investment such as the
Custodial Receipt or (b) a “Qualified
Institutional Buyer,” within the meaning of Rule
144A under the Securities Act (“Rule 144A”), in
which case the Custodial Receipt is to be
registered with The Depository Trust Company
(“DTC”), New York, New York, or any other
securities depository and the transferee has
provided the required information relating to its
status as a “Qualified Institutional Buyer” within
the meaning of Rule 144A; (ii) the transferee has
provided the required information relating to its
status as a “Qualified Purchaser,” as that term is
defined in Section 2(a)(51) of the Investment
Company Act, and the Depositor reasonably
believes such information to be true, accurate and
complete; (iii) the transferee was not formed solely
to acquire the Custodial Receipt and is not an
investment company (or other entity) relying on
Section 3(c)(1) or Section 3(c)(7) of the
Investment Company Act for an exemption from
registration thereunder as an investment company;
subject in each case to such additional conditions
imposed on permitted investors as may be set forth
in a supplement hereto; (iv) the transferee, and
each subsequent transferee, may not sell or
otherwise dispose of the Custodial Receipt except
to a further transferee who provides or has
provided a written certificate to similar effect; and
(v) the transferee has received all information
regarding the Custodial Receipt necessary to make
an informed decision to invest in the Custodial
Receipt, including information requested to verify
other information received, and has received all the
information that it has requested from the seller,
and the transferee has been afforded a reasonable
time to ask questions about the tents and
conditions of the offering of the Custodial Receipt
and has received complete and satisfactory
answers to all such questions. The transferee, and
each subsequent transferee, may not sell or
otherwise dispose of the Custodial Receipt except
to a further transferee who provides or has
provided a written certificate to similar effect.
Form of
The Zero Coupon Custodial Receipt and the Final
Underlying Securities:
Interest Payment Custodial Receipt will initially be
held at DTC in book-entry form and exchangeable,
at the option of the registered owner thereof, to
physical form.
Amendments Not Requiring Consent of
The form of the Custodial Receipts and any
Beneficial Owners of Custodial
provisions of the Custody Agreement may be
Receipts:
amended at any time by agreement between the
Custodian and the Depositor without the consent of
any of the beneficial owners of the Custodial
Receipts for purposes of (i) providing for a
qualified securities depository to replace DTC, (ii)
modifying any provisions to the extent necessary
to maintain the tax-exempt treatment or securities
treatment of the Custodial Receipts, or (iii) curing
any formal defect, omission, inconsistency or
ambiguity deemed necessary or desirable by the
Depositor; provided that, in the case of (iii)
above, the Custodian shall have received an
opinion of counsel satisfactory to the Custodian
that such amendment will not adversely affect the
interests of any beneficial owners of the Custodial
Receipts.
Amendments Requiring Consent of
All other amendments to the form of the Custodial
Beneficial Owners of Custodial
Receipts or to any provisions of the Custody
Receipts:
Agreement may be made only with the consent of
100% of the beneficial owners of the affected
Custodial Receipts, which consent will be executed
by the DTC participant (as listed on either an
official DTC position listing or an official DTC
proxy that holds the Custodial Receipts on behalf
of the registered owner).
[0022]
APPENDIX C
EXEMPLARY PERIODIC RESET CALL OPTION AGREEMENT
Periodic Reset Call
On the Closing Date, the Trust will enter into an option
Option Agreement:
transaction (the “Periodic Reset Call Option”) with the
Call Option Seller. The Periodic Reset Call Option will be
documented using ISDA documentation.
Effective Date:
Apr. 27, 2005.
Periodic Reset Call Option Style:
European (exercisable only on the Expiration Date).
Expiration Date:
Oct. 31, 2012, subject to adjustment in accordance with
the Following Business Day Convention, an Early
Termination Event or if the Valuation Date is postponed.
Expiration Time:
10:00 a.m., New York time.
Call Option Seller:
[Call Option Seller]
Call Option Guarantor:
The obligations of the Call Option Seller under the Periodic
Reset Call Option Agreement will be unconditionally and
irrevocably guaranteed by [Call Option Guarantor] pursuant
to a guarantee issued in favor of the Trust.
Notional Amount:
The product of (a) the Index Level and (b) the Number of
Units, each as determined by the Calculation Agent plus (i)
the Upward Adjustment Amount on each day between and
including the Upward Adjustment Date and the Relevant
Index Business Day or (ii) the Downward Adjustment
Amount on each day between and including the Relevant
Index Business Day and the Downward Adjustment Date,
as applicable. On the Effective Date, the Notional Amount
will equal $3,000,000 and is subject to adjustment as set
forth in “-Adjustment” herein.
“Relevant Index Business Day” means the Index Business
Day on which a hypothetical investor who initiated a
subscription or redemption of its Hedge Shares on the
Observation Date would receive or lose its exposure to the
Funds, as applicable.
“Index Level” means the published level of the Index on
an Index Business Day with the initial Index Level being
the published level of the Index on Apr. 29, 2005 (or, if
such day is not an Index Business Day, the next following
Index Business Day) (the “Initial Index Level”).
Strike Price:
Initially $2,400,000 (originally 80% of the Notional
Amount), accreting daily at the Call Option Strike
Accretion Rate, compounded monthly from the Effective
Date to, but not including, the Call Option Settlement Date,
subject to adjustment as set forth in “-Adjustment” herein.
Amounts Payable by
Under the Periodic Reset Call Option Agreement, on each
Call Option Seller:
Call Option Settlement Date the Call Option Seller is
obligated to pay to the Trust the related Call Option
Settlement Amount, if any, for such date.
Call Option Premium:
Under the Periodic Reset Call Option Agreement, the Trust
is obligated to pay to the Call Option Seller USD 600,000
(originally 20% of the Notional Amount) (the “Call Option
Premium”) on the Effective Date.
Valuation Date:
The Valuation Date for automatic exercise of the Periodic
Reset Call Option on the Expiration Date shall be the last
calendar day of the month prior to the Expiration Date (the
“Valuation Date”); provided that if the Index Level is not
published as of such date, the Calculation Agent shall refer
to the Index Level for the immediately preceding Business
Day as of which the Index Level is published in
determining the Index Level for such Valuation Date. If the
scheduled Valuation Date is not an Index Business Day due
to a Market Disruption Event, the Valuation Date shall be
postponed until the last Index Business Day of the
succeeding month; provided that if there are no Index
Business Days in the succeeding month, an Early
Termination Event shall occur.
Assuming no Market Disruption Event occurs, the
Valuation Date is scheduled to be Sep. 28, 2012.
“Index Business Day” means any day (a) as of which the
Index Level is published and (b) on which a Market
Disruption Event has not occurred.
“Market Disruption Event” means on any day, any event
that disrupts or impairs the ability of the Calculation Agent,
or any affiliate, to obtain values for such day for any
transaction or asset deemed necessary by the Call Option
Seller, or any affiliate, to Hedge, at which value the Call
Option Seller, or any affiliate, could subsequently unwind
or dispose of such transaction or asset.
Calculation Agent:
[Calculation Agent]
Index:
The Dow Jones Hedge Fund Balanced Portfolio Index, each
interest therein represented by units (each, a “Unit”). A
description of the Index is attached as Annex A hereto.
“Index Publisher” means Dow Jones Hedge Fund Indexes,
Inc.
“Index Platform Provider” means [Index Platform
Provider].
“Funds” means each of the six investable portfolio funds
underlying the Dow Jones Hedge Fund Balanced Portfolio
Index.
“Hedge Shares” mean shares (each, a “Share”)
representing interests in all of the Funds.
“Number of Units” means, initially, 1000 divided by the
Initial Index Level.
Upon the occurrence of a Downward Adjustment Event, the
Number of Units shall be reduced on the Relevant Index
Business Day, by an amount equal to the Downward
Adjustment Amount divided by the Index Level for the
Relevant Index Business Day. If a Downward Adjustment
Event results in more than one Relevant Index Business
Day, the Number of Units shall be reduced on such dates as
determined by the Calculation Agent.
Upon the occurrence of an Upward Adjustment Event, the
Number of Units shall be increased on the Relevant Index
Business Day, by an amount equal to the Upward
Adjustment Amount divided by the Index Level for the
Relevant Index Business Day.
Call Option Strike Accretion
The Base Rate plus the Spread multiplied by the Day Count
Rate:
Fraction.
Base Rate:
USD - LIBOR - BBA
Designed Maturity:
One Month.
Spread:
1.75%.
Day Count Fraction:
Actual/360.
Reset Dates:
Two Business Days prior to the first day of each month
commencing on the Effective Date.
Business Day:
Any day, other than a Saturday or Sunday, that is neither a
legal holiday nor a day on which banking institutions and
trust companies in New York City or London are
authorized or obligated by law or executive order to close.
Call Option Settlement
As of any Call Option Settlement Date, the greater of (a)
Amount(s):
the Notional Amount as of the Valuation Date minus the
Strike Price as of the Call Option Settlement Date and (b)
zero; provided that in the event there is more than one Call
Option Settlement Date, the Call Option Settlement
Amount, if any, will be proportionately paid on each such
Call Option Settlement Date.
Call Option Settlement Date(s):
Each fifth Business Day after the day that a hypothetical
investor in the Hedge Shares would receive proceeds with
respect to redeeming Hedge Shares if the Index Business
Day for such redemption were the Valuation Date, as
determined by the Calculation Agent. If such proceeds
would be received on more than one date, the Call Option
Settlement Dates will be the fifth Business Day after each
date that such proceeds would actually be received.
Adjustment:
If on any Observation Date:
(a) the Calculation Agent determines that the then-current
Adjustment Ratio exceeds the Maximum Adjustment Ratio
(such occurrence, a “Downward Adjustment Event”), the
Strike Price and the Notional Amount will be reduced by
the Downward Adjustment Amount on the related
Downward Adjustment Date (a “Downward
Adjustment”); or
(b) the Calculation Agent determines that the then-current
Adjustment Ratio is below the Minimum Adjustment Ratio
(such occurrence, an “Upward Adjustment Event”), the
Strike Price and the Notional Amount will be increased by
the Upward Adjustment Amount on the related Upward
Adjustment Date (an “Upward Adjustment”).
As used herein.
“Adjustment Amount” means any Upward Adjustment
Amount or Downward Adjustment Amount, as applicable.
“Adjustment Ratio” means the Notional Amount divided
by the difference between the Notional Amount and the
Strike Price. As of the Effective Date, the Adjustment
Ratio will equal 5.00. To determine the Adjustment Ratio,
the Calculation Agent will use the Index Level as of the
Observation Date. In the event that the Adjustment Ratio
must be calculated during the period between an
Observation Date and the corresponding Adjustment Date,
the Calculation Agent will treat each of the Notional
Amount and the Strike Price as though the Adjustment
Amount had been applied as of such Observation Date.
“Downward Adjustment Amount” means, with respect to
any Downward Adjustment, the (i) Notional Amount as of
the Observation Date related to such Downward
Adjustment minus (ii)(a) the difference between the
Notional Amount and the Strike Price, each as of the
Observation Date related to such Downward Adjustment,
multiplied by (b) the Target Adjustment Ratio; provided
that if the Downward Adjustment Amount decreases the
Strike Price to an amount below the Minimum Strike Price,
such event will constitute an Early Termination Event.
“Downward Adjustment Date” means, with respect to a
redemption of the Hedge Shares on the related Observation
Date, the day on which a hypothetical investor in such
Hedge Shares would receive proceeds with respect to such
redemption, as determined by the Calculation Agent. In the
event such proceeds would be received on more than one
date, the Downward Adjustment Date will be each date
such proceeds would actually be received.
“Maximum Adjustment Ratio” means 6.00.
“Maximum Strike Price” means $4,800,000.
“Minimum Adjustment Ratio” means 4.00.
“Minimum Strike Price” means $750,000.
“Observation Date” means a day on which the Index
Level is published commencing with May 2, 2005 and
ending with Aug. 31, 2012.
“Target Adjustment Ratio” means 5.00.
“Upward Adjustment Amount” means, with respect to
any Upward Adjustment, the difference between (i) the
product of (a) the difference between the Notional Amount
and the Strike Price, each as of the Observation Date related
to such Upward Adjustment and (b) the Target Adjustment
Ratio and (ii) the Notional Amount as of the Observation
Date related to such Upward Adjustment; provided that if
the Upward Adjustment Amount increases the Strike Price
to an amount greater than the Maximum Strike Price, the
Adjustment Amount will equal the difference of the
Maximum Strike Price and the Strike Price before such
adjustment.
“Upward Adjustment Date” means, with respect to a
subscription for Hedge Shares on the related Observation
Date, the day that a hypothetical investor in the Hedge
Shares would deliver proceeds with respect to such
subscription, as determined by the Calculation Agent.
Events of Default and
The Event of Default specified in clause (c) under the
Termination Events:
heading “The Periodic Reset Call Option Agreement -
Events of Default” and only the Termination Event
specified in clause (c) under the heading “The Periodic
Reset Call Option Agreement - Termination Events”
applies with respect to the Periodic Reset Call Option
Agreement. See “The Periodic Reset Call Option
Agreement” in the Private Placement Memorandum.
Additional Termination Events:
The following constitute Additional Termination Events
under the Periodic Reset Call Option Agreement:
(i) The Index Publisher or the Index Platform Provider
fails to provide the Calculation Agent with the
information the Calculation Agent deems necessary to
determine compliance with the index methodology or
asset allocation policy in a timely manner;
(ii) The Index Publisher or the Index Platform Provider
(a) fails to comply with the Index methodology as
stipulated on the Effective Date or (b) announces that it
will make, or does make, a material change in the formula
for or the method of calculating the Index or in any other
way materially modifies the Index or the Hedge Shares or
permanently cancels the Index;
(iii) The Index Publisher or the Index Platform Provider
fails to calculate and publish the Index Level for more
than 5 consecutive Business Days;
(iv) The Index is terminated;
(v) The Index, the Index Publisher, the Index Platform
Provider, the Administrator or the Investment Manager
(as defined herein) materially breaches any applicable law
or regulation or any regulatory or governmental authority
brings an administrative or judicial proceeding or
commences an inquiry against the Index Publisher, the
Administrator or the Investment Manager alleging any
misconduct or wrongdoing;
(vi) The annualized Volatility of the Index Level
exceeds 15% for a six-month rolling window.
“Volatility” for a given time window, means, as of any
date of determination and with respect to the Index, the
annualized standard deviation of the monthly percentage
changes in the level of the Index for the particular time
window preceding such date of determination, expressed
as a percentage, as determined by the Calculation Agent;
(vii) There is a change in tax law, tax regulations,
practice or the interpretation of tax law or tax regulations
or practice by any court, tribunal or regulatory authority
which could have an adverse economic impact for the
Trust with respect to the Notes or the Call Option Seller's
Hedge (as defined below);
(viii) The occurrence of a Hedging Disruption Event that
is not waived by the Call Option Seller. A “Hedging
Disruption Event” means that the Call Option Seller, or
any affiliate, is unable, after using commercially
reasonable efforts, to Hedge or would incur a materially
increased amount of tax, duty, expense or fee, as
compared to its costs and anticipated costs as of the
Effective Date, to hedge. As used herein, “Hedge”
means: (A) acquire, establish, re-establish, substitute,
maintain, unwind or dispose of any transaction(s) or
asset(s) the Call Option Seller deems necessary to hedge
the risk of entering into and performing its obligations
with respect to the Periodic Reset Call Option or (B) to
realize, recover or remit the proceeds of any such
transaction(s) or asset(s).
(ix) The Administrator or the Investment Manager
ceases to act in the capacity of administrator or
investment manager and a replacement administrator or
investment manager is not appointed immediately and/or
is not acceptable to the Calculation Agent.
(x) The Index Level is no longer calculated in US
Dollars;
(xi) The occurrence of an Early Redemption Event
under the Trust Agreement that results in the early
redemption of the Certificates;
(xii) The Downward Adjustment Amount decreases the
Strike Price to an amount below the Minimum Strike
Price;
(xiii) A termination of the License Agreement or the
Sublicense Agreement;
(xiv) A Market Disruption Event occurs on the scheduled
Valuation Date and there are no Index Business Days in
the succeeding month;
(xv) There is a change in or adoption of any law due to
the promulgation of, or any change in interpretation by
any court, tribunal or regulatory authority of any law
which causes it to become unlawful for the Call Option
Seller, the Call Option Guarantor or any of their affiliates
to perform any obligations hereunder or otherwise has
material adverse consequences for the Call Option Seller,
the Call Option Guarantor or any of their affiliates; or
(xvi) The Index Publisher is no longer Dow Jones Hedge
Fund Indexes, Inc. or the Index Platform Provider is no
longer Lyra Capital LLC.
As used herein:
“Administrator” means an administrator of a transaction
or asset deemed necessary by the Issuer, or any affiliate, to
Hedge.
“Investment Manager” means an investment manager of a
transaction or asset deemed necessary by the Issuer, or any
affiliate, to Hedge.
Early Termination Amount:
An amount equal to the market value of the Periodic Reset
Call Option as of the last Business Day of the month
immediately preceding the month in which the Early
Termination Date occurs, as determined by the Calculation
Agent, less the cost and total losses to the Call Option
Seller, or any affiliate, of unwinding any related Hedge
positions, as determined by the Call Option Seller; provided
that if the Calculation Agent determines that a Market
Disruption Event has occurred on such day, the Calculation
Agent shall determine the Early Termination Amount with
reference to the next succeeding end-of-month Business
Day upon which no Market Disruption Event occurs;
provided, further, that if a Market Disruption Event occurs
on each of the six succeeding end-of-month Business Days,
then the Calculation Agent shall make a good faith estimate
of the market value of the Periodic Reset Call Option as of
such sixth end-of-month Business Day.
In determining the Early Termination Amount, the
Calculation Agent may, but is not required to, consider the
following: (i) relevant market data in the relevant market
including, without limitation, relevant rates, prices, yields,
volatilities, spread or correlations, (ii) relevant market data
from internal sources, including any affiliates of the
Calculation Agent, and (iii) any other information deemed
relevant by the Calculation Agent.
“Early Termination Date” means the date provided in the
Call Option Seller's notice of early termination to the Trust.
The Early Termination Amount, if any, will be paid by the
Call Option Seller to the Trust. | In one aspect, the invention comprises a method comprising: (1) selling a note to an investor for a specified amount; and (2) using proceeds from selling the note to purchase (a) one or more zero coupon municipal bonds, and (b) an option on at least one of the group comprising: a hedge fund, a fund of funds, and a hedge fund index; wherein the note entitles the investor to substantially all of the returns on the one or more bonds and on the option, wherein the one or more bonds are configured to provide a return substantially equal to the specified amount, and wherein the option is a European option. This option can be a variable option. | 6 |
BACKGROUND
The ability to make decisions by conditional branching is an essential requirement for any computer system which performs useful work. The decision to branch or not to branch may be based on one or more events. These events, often referred to as conditions, include: positive, negative or zero numbers, overflow, underflow, or carry from the last arithmetic operation, even or odd parity, and many others. Conditional branches are performed in digital computers by conditional branch instructions. Conditional branch instructions may be used to construct such high level programming constructs as loops and if-then-else statements. Because the loops and if-then-else programming constructs are so common, it is essential that the conditional branch instructions which implement them excecute as efficiently as possible.
A computer instruction is executed by performing one or more steps. Typically, these steps are first to fetch the instruction pointed to by a program counter, second to decode and perform the operation indicated by the instruction and finally to save the results. A simple branch instruction changes the contents of the program counter in order to cause execution to "jump" to somewhere else in the program. In order to speed up the execution of computer instructions, a technique of executing more than one instruction at the same time, called pipelining, was developed. Pipelining permits, for example, the central processing unit, CPU, to fetch one instruction while executing another instruction and while saving the results of a third instruction at the same time. In pipelined computer architectures, branching is an expensive operation because branch instructions may cause other instructions in the pipeline to be held up pending the outcome of the branch instruction. When a conditional branch instruction is executed with the condition true, it causes the CPU to continue execution at a new address referred to as a target address. Since instruction fetching is going on simultaneously with instruction decoding and execution in a pipelined computer, the computer has already fetched the instruction following the branch instruction in the program. This is a different instruction than the instruction at the target address. Therefore, the CPU must hold up the instruction pipeline following the branch instruction until the outcome of the branch instruction is known and the proper instruction fetched. In order to maximize throughput of the computer, computer designers have attempted to design computers which maximize throughput by minimizing the need to hold up the instruction pipeline.
In the prior art, several schemes have been used to avoid holding up the instruction pipeline for conditional branches. First, some high performance processors have used various branch prediction schemes to guess whether the conditional branch will be taken or not. This approach requires extensive hardware and is unacceptable in all but the highest performance computers because of the expensive hardware required. Second, other architectures have fetched both the instruction in the program following the branch and the instruction at the branch target address. This approach is unacceptable because it also requires expensive hardware and additional memory accesses to always fetch both instructions. Third, some architectures have a bit in the instruction to tell the computer whether it is more probable for the instruction following the branch or the instruction at the branch target address to be executed. The computer then fetches the more probable instruction and holds up the pipeline only if the guess is wrong. This approach requires expensive hardward and if the guess is wrong causes additional time to be spent backing up the pipeline and fetching appropriate instruction. Fourth, other architectures allow two bits which instruct the CPU to always or never execute the instruction following the branch instruction based on whether the branch is taken or not taken. This architecture uses too many bits from the instruction thereby reducing the maximum range of the branch instruction. Finally, still other architectures always execute the instruction in the program following the branch instruction before taking or not taking the branch.
The technique of executing the instruction in the program following the branch instruction is known as delayed branching. Delayed branching is desirable since the instruction in the pipeline is always executed and the pipeline is not held up. This occurs because delayed branching gives the computer time to execute the branch instruction and compute the address of the next instruction while executing the instruction in the pipeline. Although this technique avoids holding up the instruction pipeline, it may require placing a no operation instruction following the branch instruction, which would not improve performance since the additional memory access negates any improvement.
One software technique which takes advantage of delayed branching is merger. The concept of merger described here is where the loop branch instruction is at the end of the loop. Merger takes advantage of delayed branching by duplicating the first instruction of the loop following the loop's branch instruction and making the branch target address the second instruction of the loop. One potential problem with merger is that on exit from the loop, the program does not necessarily want to execute the merged instruction following the branch instruction again. This is a problem for architectures which always use delayed branching.
When many prior art computer systems determine that a branch is about to be executed, the computer systems hold up, or interlock, the instruction pipeline. Interlocking the pipeline involves stopping the computer from fetching the next instruction and preventing the pipeline from advancing the execution of any of the instructions in the pipeline. Interlocking reduces the performance increase gained by pipelining and therefore is to be avoided.
What is needed is a method of conditional branching which minimizes the amount of hardware and performance reductions. The method should take as few bits of the instruction as possible since each bit taken effectively halves the maximum range of the branch instruction.
SUMMARY
In accordance with the preferred embodiment of the present invention, a method and apparatus are provided for conditional branching within a digital computer. The preferred embodiment of the present invention provides a branch instruction which statically predicts whether the branch will be taken or not taken based on the branch displacement. The method uses delayed branching where possible but also provides for nullification of the delay slot instruction following the branch instruction where the delay slot instruction cannot be used efficiently.
The present invention is superior to the prior art in several ways. First, the preferred embodiment of the present invention is capable of a branch frequently/branch rarely prediction for conditional branch instructions based on the existing sign bit of the branch displacement without requiring any other bit in the instruction. Second, the preferred embodiment of the present invention optimizes the use of the instruction immediately following the conditional branch which reduces the probability of holding up the instruction pipeline and its resulting reduction in performance. Third, the preferred embodiment of the present invention nullifies the instruction following the branch only in cases then the instruction cannot be used. Finally, the preferred embodiment of the present invention provides a more flexible and efficient nullification scheme based on direction of branching rather than always executing or never executing the instruction following the branch.
DESCRIPTION OF DRAWINGS
FIG. 1 is a branch instruction in accordance with the preferred embodiment of the present invention.
FIG. 2 illustrates a method of branching in accordance with the preferred embodiment of the present invention.
FIG. 3 is a flow chart of the method of branching.
FIG. 4 is a functional block diagram of an apparatus in accordance with the preferred embodiment of the present invention.
FIG. 5 is a timing state diagram of the apparatus in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a branch instruction in accordance with the preferred embodiment of the present invention. The branch instruction 501 consists of 32 bits of information used by the computer to execute the instruction. This instruction combines the function of branching with the operation of comparing two operands, although the present invention could be implemented by a branch only instruction as well. The instruction 501 contains a six bit operation code field 502, a five bit source register address field 503, a five bit second source register address field 504, a three bit condition code field 505, a eleven bit branch displacement field 506 and one bit displacement field sign bit 508, and a nullify bit 507. The operation code field 502 identifies this instruction as a compare and branch instruction. The first and second source register address fields 503 and 504 identify the registers whose contents will be compared. The branch displacement, which may be positive or negative, is determined by fields 508 and 506. This displacement is used to calculate the target address for the branch. The next instruction in the instruction pipeline may be nullified according to the preferred embodiment of the present invention by setting the nullify bit 507.
In the preferred embodiment of the present invention, the execution of the current instruction may be nullified. The purpose of nullification is to make the instruction appear as if it never existed in the pipeline even though the instruction may have been fetched and its operation performed. Nullification is accomplished by preventing that instruction from changing any state of the CPU. To prevent changing the state of the computer, the nullification process must prevent the writing of any results of the nullified instruction to any registers or memory location and prevent any side effects from occurring, for example, the generation of interrupts caused by the nullified instruction. This is performed in the preferred embodiment by qualifying any write signals with the nullify signal generated in the previous instruction thus preventing the instruction from storing any results of any calculation or otherwise changing the state of the computer system. A simple way of qualifying the write signals of the current instruction is by `AND`ing the write signals with a retained copy of the nullify signal generated in the previous instruction. The nullify signal generated by an instruction may, for example, be saved in the processor status word for use in the following instruction. Nullification is a very useful technique because it permits an instruction to be fetched into the pipeline without concern as to whether a decision being made by another instruction in the pipeline may cause this instruction not to be executed. The instruction simply progresses through the pipeline until it comes time to store its results and the instruction may then be nullified at the last minute with the same effect as if the instruction never existed in the pipeline.
In a pipelined computer system there are two distinct concepts as to the next instruction to be executed. The first concept is a time sequential instruction, which is the next instruction in the instruction pipeline after the current instruction. This instruction will be executed after the current instruction and the results of the operation stored unless nullified. The second concept is a space sequential instruction. This is the instruction immediately following the current instruction in the program. Generally, the space sequential instruction for the current instruction will be the time sequential instruction. The execption to the rule occurs with taken branch instructions, where the time sequential instruction is the instruction at the target address which is generally not the space sequential instruction of the branch instruction.
The delay slot instruction is the time sequential instruction of a branch instruction. Generally, the delay slot instruction will be the space sequential instruction of the branch instruction. The exception to this rule is the case of a branch following a branch instruction. For this case, the delay slot instruction for the second branch instruction will be the target address of the first branch instruction rather than the space sequential instruction of the second branch instruction.
Unconditional branching in the preferred embodiment of the present invention clearly illustrates the concept of nullification and the delay slot instruction. With the nullify bit off, the delay slot instruction of the unconditional branch instruction is always executed. With the nullify bit off, the delay slot instruction of the unconditional branch instruction is always nullified. This is equivalent to never executing the delay slot instruction.
FIG. 2 illustrates a method of conditional branching in accordance with preferred embodiment of the present invention. A computer practicing the method of FIG. 2 has a program 101 consisting of instructions 100 including a conditional branch instruction 102. The space sequential instruction to the branch instruction 102 is instruction 103. For a conditional branch instruction 102 with negative branch displacement, instruction 104 is at the target address. For a conditional branch instruction 102 with a positive branch displacement, instruction 105 is at the target address. The execution of the program is illustrated by graphs 110, 111, 112, 113, and 114. During normal execution, the program executes the current instruction and then executes the space sequential instruction to the current instruction.
Graphs 110, 111 and 113 illustrate the operation of a branch instruction with the nullify bit off. This corresponds to the `never nullify` or `always execute` case. The delay slot instruction following the branch instruction is always executed regardless of whether the branch if taken or not and whether it has a positive or negative displacement. When the branch condition is false, execution continues with the space sequential instruction 103 as shown in graph 110. When the branch condition is true, the delay slot instruction is executed and then the instruction at the target address is executed as shown in graph 111 for a negative displacement branch and in graph 113 for a positive displacement branch.
Graph 110, 111, 112 and 114 illustrate the operation of a branch instruction with the nullify bit on. This corresponds to the `sometimes nullify` case as described below. With the nullify bit on, the delay slot instruction may be nullified depending on the direction of the branch and whether the condition determining whether the branch is taken or not is true or false. Graphs 110 and 114 illustrate the operation of the branch instruction when the condition triggering the branch is false causing the branch not to be taken. If the branch displacement is positive, the delay slot instruction is executed as shown by graph 110. If the branch displacement is negative, the delay slot instruction is nullified as shown by graph 114. The dotted line on graphs 112 and 114 indicate that the delay slot instruction, although fetched, will be nullified as it if never existed in the instruction pipeline.
Graphs 111 and 112 illustrate the operation of the branch instruction with the nullify bit on when the condition triggering the branch is true causing the branch to be taken. If the branch displacement is positive, the delay slot instruction is nullified as shown in graph 112 and execution continues at the target address. If the branch displacement is negative, the delay slot instruction is executed as shown in graph 111 before continuing at the target address.
FIG. 3 is a flow chart of the method of branching. The graphs 111 through 114 may be more clearly understood by referring to the flow chart. The first step is to determine whether the nullify bit is on. If the nullify bit is off, then the delay slot instruction for the branch instruction is always executed. This occurs whether or not the branch is taken. If the nullify bit is on, then the delay slot instruction following the branch is not executed unless the branch is taken and the branch displacement is negative, or unless the branch is not taken and the branch displacement is positive.
The operation of the preferred embodiment of the present invention embodies a very simple but effective method of static branch prediction which predicts whether the branch will be taken or not, and therefore which instruction to fetch, based on whether positive or negative displacement branches are taken. Its effectiveness depends on computer software following a set of software conventions in implementing certain higher level program control constructs by means of a conditional branch instruction. For example, a loop construct is implemented by a backward conditional branch, so that a branch instruction with a negative displacement will be taken frequently. In fact, it will be taken N-1 out of N times for a loop that is executed N times. Another example of the softward conventions assumed is that an if-then-else construct is implemented by a forward branch to the rarely taken part, allowing the more frequently executed part to lie immediately following the branch instruction in the not taken branch path. For example, the forward branch may be to an error handling routine which rarely gets executed in a normal program. In addition, the preferred embodiment of the present invention having a nullify bit generalizes and optimizes the use of the delay slot instruction in conjunction with the static branch prediction technique described above. With the nullify bit on, a backward conditional branch that is taken or a forward conditional branch that is not taken, being the tasks that are predicted to be frequent by the static branch prediction technique, cause the delay slot instruction to be executed. Hence, some useful instruction in the frequent path may be executed as the delay slot instruction, for example, as described in the merger technique above. With the nullify bit on, a backward conditional branch that is not taken or a forward conditional branch that is taken, being the tasks that are predicted to be rare, cause the delay slot instruction to be nullified. Hence, nullification which reduces performance occurs only in the rare case.
With the nullify bit off, the delay slot instruction is always executed. This corresponds to the case where an instruction common to both the branch taken and the branch not taken paths can be designated as the delay slot instruction.
FIG. 4 is a functional block diagram of an apparatus in accordance with the preferred embodiment of the present invention. The apparatus contains six functional elements: an instruction memory 301, an optional virtual address translation unit 302, an instruction unit 303, an execution unit 304, an optional floating point unit 305 and an optional register file 306. These functional elements are connected together through five busses: a result bus 310, a first operand bus 311, a next instruction bus 312, a second operand bus 313 and an address bus 314. Only the execution unit 304 and the instruction unit 303 are involved in performing the operation of the preferred embodiment of the present invention. The execution unit generates and/or stores the conditions on which the decision to branch or not to branch is made. The instruction unit performs the branch by generating the address of the next instruction to be fetched from the memory and provides means for storing the address into the program counter. In the preferred embodiment of the present invention, the memory unit is a high speed cache with speed on the order of the logic used in the execution unit.
FIG. 5 is a timing state diagram of the apparatus in FIG. 4. The timing diagram illustrates four stages involved in the execution of instructions 401, 402, 403 and 404. Time line 460 is divided into stages with the time progressing to the right. The four timing stages for each instruction are: an instruction address generation stage 410, an instruction fetch stage 411, an execute stage 412, and a write stage 413. The execution of instructions may be pipelined to any depth desired. The preferred embodiment of the present invention contains a four stage pipeline. As shown in FIG. 5, four instructions are being executed at any one time. At time 450, the write stage of instruction 401 is overlapped with the execution stage of instruction 402, the instruction fetch stage of instruction 403 and the instruction address generation stage of instruction 404. This means for a branch instruction that next instruction will have been fetched while the branch instruction is in the execution stage. During the instruction address generation stage, the address of the next instruction is calculated from the program counter which contains the address of the next instruction to be executed and is located in the instruction unit 303. During the instruction fetch stage, the next instruction is fetched from the instruction memory 301. This is performed by applying the contents of the address calculated in the instruction address generation stage onto the address bus 314 and transferring the contents of that address to the next instruction bus 312 where it is decoded by the instruction unit. The branch instruction may be combined with other operations, for example, a compare operation, which would be also decoded and performed at this time in the execution unit 304.
In the execute stage 412, the branch instruction is performed. During the execute phase 412 both the target address of the branch instruction and the address of the space sequential instruction to the branch instruction are generated. At this time if the instruction is combined with another operation, that operation is performed. At the end of the execution phase, one of the two addresses is transferred into the program counter. Which address to transfer to the program counter is determined by the condition generated or stored in the execution unit 304. During the write phase 413, no operation occurs unless a result from a combined instruction needs to be stored. By performing all writing of any results to memory or registers and any side effects like interrupt acknowledgement caused by an instruction no earlier than stage 412 and 413, this approach enables a simpler implementation of the concept of nullifying an instruction which is always in the pipeline. | A method and apparatus for efficient branching within a central processing unit with overlapped fetch and execute cycles which optimizes the efficient fetching of instructions. | 6 |
FIELD
[0001] The present invention relates to packages for holding adhesives.
BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
[0003] In many roofing applications, for example in large, flat commercial roof decks, a roofing membrane is used to seal and protect the roof deck from environmental weather conditions. The roofing membrane may be made of various materials, such as polymeric materials including EPDM (ethylene propylene diene M-rubber) or TPO (thermoplastic polyolefin). The roofing membrane is adhered overtop insulation boards or panels. The insulation boards are typically secured to the roofing substrate or roof deck via an adhesive composition. A conventional adhesive composition used to adhere the insulation boards to the roof deck includes polyurethane. The polyurethane adhesives are oftentimes applied directly onto the roof deck via an applicator system and the insulation boards are then laid onto the roof deck surface. Conventional polyurethane adhesives oftentimes include two separate parts that are mixed by an applicator just prior to being applied onto the surface of the roof deck. The two parts include an isocyanate blend and a simple polyol blend. Upon mixing, the isocyanate blend reacts or crosslinks with the simple polyol blend to form the polyurethane adhesive.
[0004] However, these conventional two-part polyurethane adhesives are sensitive to weather conditions due to the effects of temperature on the viscosity, and therefore the reaction speed, of the adhesive. Accordingly, conventional two-part polyurethane adhesives are packaged and formulated into various grades, such as Summer, Winter, and Regular, that vary the composition of the adhesive in order to account for temperature.
[0005] Therefore, there is room in the art for adhesive packages for a pump driven applicator system that reliably pumps adhesives.
SUMMARY
[0006] A packaging unit for holding an adhesive or a component of an adhesive includes an outer container and an inner member placed in the outer container. The outer container has a generally box shape and further has a perforation around the perimeter of the container. The inner member has a spout through which the adhesive or component of the adhesive is received and dispensed. Tearing the perforation separates the outer container into a top portion and a bottom portion so that the inner member is removable from the outer container.
[0007] Further features, advantages, and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0008] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the views. In the drawings:
[0009] FIG. 1 is a perspective view of a bulk packaging unit for adhesives in accordance with the principles of the present invention;
[0010] FIG. 2 is a top view of the bulk packaging unit of FIG. 1 ;
[0011] FIG. 3 is a partial view of the bulk packaging unit of FIG. 1 illustrating a handle;
[0012] FIG. 4 is a perspective view of the bulk packaging unit of FIG. 1 with the top of an outer container removed;
[0013] FIG. 5 is a view of a die cut panel from which an outer container of the bulk packaging unit of FIG. 1 is formed;
[0014] FIG. 6 is an alternative bulk packaging unit for adhesives in accordance with the principles of the present invention; and
[0015] FIG. 7 is yet another alternative bulk packaging unit for adhesives in accordance with the principles of the present invention.
DETAILED DESCRIPTION
[0016] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.
[0017] Referring now to the drawings, a bulk packaging unit for storing and transporting an adhesive or a component of an adhesive is shown at 10 in FIGS. 1-3 . The packaging unit 10 can be used, for example, with adhesive applicators such as those described in U.S. patent application Ser. No. 13/246,482, filed Sep. 27, 2011 and entitled “Adhesive Bead Applicator,” and U.S. patent application Ser. No. 13/399,417, filed Feb. 17, 2012 and entitled “Adhesive Applicator,” the contents of which are incorporated in their entirety. The packaging unit 10 includes an inner flexible member or bag 12 contained in an outer container or carton 14 . The bag 12 is made of a water-impermeable flexible material and has a spout 26 . The bag 12 is filled with an adhesive or a component or part of an adhesive. In some arrangements, a screw cap is removed from the spout and then the adhesive or adhesive component is poured into the bag 12 until the adhesive or adhesive component fills the bag 12 . When the bag 12 is being filled, the bag 12 can reside in the carton 14 or can be outside the carton 14 and then placed into the carton after the bag is filled. In either case, the bag 12 closely conforms to the interior of the carton 14 when the bag 12 is filled with the adhesive or adhesive component.
[0018] The bag 12 receives the adhesive or adhesive component for pre-use storage, shipping, use in an adhesive applicator, and post-use storage. The bag 12 is generally made of a suitable plastic material that can be translucent or transparent to facilitate viewing of the contents in the bag 12 . The spout 26 generally includes threads to allow threading of the spout with the threads of the cap. After the bag is filled with the adhesive or adhesive component, the screw cap can be twisted on the spout 26 or a valved device 28 can be connected or attached, for example, by threading threads of the valved device 28 to the spout 26 to seal the contents of the bag 12 . Accordingly, the bag 12 and its contents can be shipped in the carton 14 with a screw cap or the valved device 28 . The valved device 28 can include a poppet valve 30 that engages a stem member of a conduit to facilitate flow of the contents of the bag 12 from the bag. The valved device can be a quick release or connect nozzle for faster change outs and connection with a conduit. Such quick connect couplers or nozzles include those available from Colder Products of St. Paul, Minn. The bag 12 can further include a handle 24 that allows the bag 12 to be carried and to be placed and removed from the carton 14 . In a particular arrangement, the handle 24 extends through an opening 29 in the carton 14 after the carton 14 is closed off to enclose the bag 12 in the carton 14 to enable the bag 12 with its contents and the carton 14 to be carried together.
[0019] The carton 14 is in some arrangements is a corrugated rigid or semi-rigid, box-like structure made from a die cut panel shown in FIG. 5 . The carton 14 encloses the bag 12 and, hence, supports and protects the bag 12 and its contents for transportation and use of the packaging unit 10 . The carton 14 includes two inner panels 16 and 18 and two outer panels 20 and 22 . After the bag 12 is placed in the carton 14 , the two inner panels 16 and 18 are folded in and then the outer panels 20 and 22 are folded in on top of the inner panels 16 and 18 . Again, the bag 12 can be filled with its contents prior to being placed in the carton 14 or after it is placed in the carton 14 . The panels 20 and 22 can be sealed shut with a piece of tape 60 on one or both sides of the seam formed by the adjacent edges of the panels 20 and 22 or the panels 20 and 22 can be sealed by any other suitable means.
[0020] The panel 20 is provided with a flap portion 21 than can be pulled out to define the opening 29 . In some arrangements the panel 20 includes a small opening 23 that allows the placement of a finder or thumb to pull out the flap portion 21 so that the handle 24 of the bag 12 can extend through the opening 29 as described previously.
[0021] To form the box like structure of the carton 14 , the four sections of the panel shown in FIG. 5 are folded along the line 50 , 52 , and 54 . A smaller section 48 is folded along the line 56 such that the section 48 can be sealed to the section 58 with tape, glue, or any other suitable means. The carton 14 further includes bottom panels 40 , 42 , 44 , and 46 that are folded inwards to form the bottom of the carton 14 .
[0022] In particular arrangements, the carton includes a tear tape 34 that is pulled to separate the carton 14 along a perforation 32 . Specifically, as shown in FIG. 4 , the perforation allows the carton 14 to be separated into a top portion 14 A and a bottom portion 14 B. The perforation 32 is located about a distance, /, from the top of the carton 14 . Accordingly, when the packaging unit 10 is in use, an operator can remove the top portion 14 A to allow access to the bag 12 with its contents so that the bag 12 can be removed from the bottom portion 14 B and connected to an adhesive applicator with the valved device 28 , such as the quick connect device described above.
[0023] Referring now to FIG. 6 , there is shown at 100 another arrangement of a packaging unit for an adhesive or adhesive component for use in an adhesive applicator. The packaging unit 100 includes a flexible inner member or bag 112 enclosed in a container or carton 114 . The bag 112 includes a spout 126 with a screw on cap. Alternatively, the spout 126 can include a valved device such as, for example, a quick connect coupler that was described previously. The bag 112 also includes a handle 124 to enable placing the bag 112 and its contents into the container 114 and removing it from the container 114 , as well. Unlike the packaging unit 10 described earlier, the carton 114 of the packaging unit 100 does not include an opening through which the handle 124 extends. The carton 114 , however, does include a perforation 132 that facilitates separating the carton 114 into a bottom portion 114 A and a top portion 114 B, for example, by pulling on a tear tape as discussed previously. The packaging unit can include a single carton 114 or it can include a four sided stack liner 113 to increase crush resistance of the packaging unit. Note that any of the other packaging units described herein can include a stack liner as well. The stack liner 113 is made of a corrugated construction or any other suitable construction. The carton 114 and the bag 112 can be formed and made of the same materials as the carton 14 and the bag 12 .
[0024] Another arrangement of a packaging unit is shown in FIG. 7 at 200 . The packaging unit 200 includes a carton 214 with a first section 260 and a second section 262 into which respective bags 12 or 112 can be placed. Again the spout 126 can be sealed with a screw cap or a valved device. The carton 214 includes a perforation 232 that facilitates separating the carton 214 into a bottom portion 214 A and a top portion 214 B, for example, by pulling on a tear tape as discussed previously. The carton 214 can include an inner carton and an outer carton or it can be a single carton in which the bags 112 are placed. The carton 214 and bag 112 can be formed and made of the same materials as the carton 14 and the bag 12 . The packaging unit 200 allows the transportation, use, and storage of both components in respective sections 260 and 262 for both components of a two-part adhesive.
[0025] Any of the aforementioned cartons 14 , 114 , or 214 can be provided with an opening in a side of the carton to allow viewing of the bag inside the carton. Further, any of the aforementioned cartons 14 , 114 , or 214 can be provided with a coating on the inside, outside, or both the inside and outside of the carton. The coating can be water resistant or water proof.
[0026] The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A packaging unit for holding an adhesive or a component of an adhesive includes an outer container and an inner member placed in the outer container. The outer container has a generally box shape and further has a perforation around the perimeter of the container. The inner member has a spout through which the adhesive or component of the adhesive is received and dispensed. Tearing the perforation separates the outer container into a top portion and a bottom portion so that the inner member is removable from the outer container. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to electrical test apparatus, and more particularly to a low cost indicator of excessive temperature at the terminals of an electrical device.
Most items of electrical apparatus intended for operation from commercial power sources characteristically employ terminations for the wiring that supply them with power. For proper and safe operation, these items of electrical apparatus must be wired correctly at their terminations. An improperly terminated conductor, whether the termination be the contacting blade surfaces of a plug-in type connection or a terminal contacting a stranded or solid conductor, may overheat at such termination when carrying current, bringing with it the hazard of damaging any combustible material that may happen to be in contact with the overheated terminal. If detected early, however, this hazard can be overcome by correcting the wiring which brought it about. Therefore, it would be desirable to provide a simple, low cost temperature sensor that can reliably provide a warning of potential hazard due to electrical wiring overheating. In the event the terminations which might be subject to overheating are located within a junction box housing a duplex receptacle, it would be convenient to employ such sensor in a form which readily lends itself to being plugged into the receptacle. Alternatively, if the terminations to be monitored are located in a cube tap, the sensor may conveniently be built into the tap as an integral portion thereof.
Indicator devices are disclosed and claimed in Kornrumpf et al.--U.S. Pat. No. 4,310,837, issued Jan. 12, 1982, and assigned to the instant assignee. However, for the devices shown in U.S. Pat. No. 4,310,837, the temperature sensor (e.g. thermistor) relies on the material composition of the prongs to couple heat from the electrical termination to the sensor and with respect to the terminations the sensor is located at the distal end of the prong. This causes a lag between changes in temperature at the termination and the instant they are detected by the sensor. Further, the devices of U.S. Pat. No. 4,310,837 use current supplied to the electrical termination being monitored to provide an indication of overheating, thereby increasing heating of the termination.
Additionally, no means is disclosed in U.S. Pat. No. 4,310,837 to provide a quantitative indication of the temperature of the electrical termination. A temperature rise at an electrical termination caused by electrical losses and sufficient to issue an excessive temperature warning by devices of U.S. Pat. No. 4,310,837 may not occur until a substantial current flows through the termination. By monitoring the actual temperature rise of an electrical termination and the amount of current supplied thereby, the adequacy of termination wiring based on predetermined safe temperature rise limits for a known current may be determined without disassembling hardware to gain access to the termination.
Accordingly, an object of the present invention is to provide low cost apparatus for sensing overheating of current-carrying electrical conductors wherein a quantitative indication of a temperature of the conductors is provided.
Another object is to provide apparatus for reliably identifying improper termination of electrical conductors without need for line voltage power.
Another object is to provide a cube tap which signals an indication of overheating therein.
Another object is to provide a plug-in type device for sensing overheating of a duplex receptacle wherein the sensing means is in close proximity to the terminals.
SUMMARY OF THE INVENTION
In accordance with the present invention, a temperature indicator for an electrical power circuit connected to at least one termination comprises a thermocouple for producing a voltage at an output thereof wherein the thermocouple is thermally coupled to and electrically isolated from the at least one termination and wherein the voltage is proportional to the temperature of the at least one termination, and display means coupled to the thermocouple output for exhibiting the temperature of the termination in response to the voltage.
Further, in accordance with the present invention a method for identifying an improperly terminated power circuit connected to at least one termination comprises determining the temperature of the termination, injecting a known quantity of current through the termination, redetermining the temperature of the termination, subtracting the temperature first determined from the temperature redetermined and dividing the remainder by the known quantity of current injected to generate a rate of temperature rise, comparing the rate of temperature rise generated with a predetermined rate of temperature rise and identifying the power circuit as improperly terminated if the rate of temperature rise generated exceeds the predetermined rate of temperature rise.
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the detailed description taken in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of one embodiment of the invention, shown thermally coupled to terminations supplying power to a load circuit.
FIG. 2 is a sectional view of a prong contact fabricated in accordance with the present invention.
FIG. 3 is a part sectional and part schematic view of an embodiment of the invention shown thermally coupled to terminations supplying power to a load circuit.
FIG. 4 is a part sectional and part schematic view of a self-contained device employing a thermocouple to sense overheating in a duplex receptacle.
DETAILED DESCRIPTION
FIG. 1 illustrates the circuit embodying the instant invention. A power source 10, such as the conventional 110-120 volt, 60 hertz, AC type common in the United States, is connected to a load 13 through a pair of terminations 11 and 12. In many instances, these terminations are of the screw-down terminals type which contact the wires with a compressive force. In the majority of such instances, the contact is properly terminated and provides a path of very low resistance for the load current, so that overheating is not likely to occur. In those few instances where the contact is not properly terminated, however, a path of much higher resistance may be presented to the load current as where, for example, an insufficient number of strands in the wire make contact with the terminal because they were cut too short or are bent away from the terminal, or where some amount of insulation exists between the terminal and the wire. The high resistance path, if carrying sufficient current, may undergo a large temperature rise because of the power loss occurring therein. The temperature thus reached conceivably could exceed the safe temperature of many combustible materials which, if in contact with the wire of termination in the region of high power loss, might be damaged. To provide warning of the resulting safety hazard, an on/off indicator, typically a light emitting diode (LED) 29 (having relatively low current activation to minimize drain on the power source), is connected in series to the parallel outputs of amplifiers 22 and 23 such as differential operational amplifiers available from Analog Devices, Norwood, Mass. through blocking diodes 24 and 25, respectively, and a threshold detector 26, having a high input impedance, such as a temperature compensated electronic reference junction available from Hy-Cal Engineering Co., Santa Fe Springs, Calif. Adjustable level set resistor 27, which is connected between the inverting (-) input of threshold detector 26 and ground potential, controls the threshold voltage value above which a value of voltage supplied to the non-inverting (+) input of threshold detector 26 from amplifiers 22 and 23 induces threshold detector 26 to provide a voltage at its output sufficient to cause LED 29 coupled thereto to be lit. The inputs of amplifiers 22 and 23 are each respectively connected to the output of a thermocouple 20 and 21, each thermocouple providing a voltage signal at its output directly proportional to its temperature and each thermally responsive (or thermally coupled, as through heat paths 15 and 16, respectively) to and electrically isolated from terminals 11 and 12, respectively. Power source 19, such as a battery, is electrically isolated from terminals 11 and 12 and provides operating voltage +V to amplifiers 22 and 23 and threshold detector 26. Of course, voltage from terminals 11 and 12 may be conditioned, as by a rectifier to provide operating voltage +V with the understanding that additional current and therefore an additional heating source is thereby added to terminals 11 and 12. Additionally, meter 28 may be connected in series to the parallel outputs of amplifiers 22 and 23 through block diodes 24 and 25, respectively. The ground references of battery 19, amplifiers 22 and 23, threshold detector 26, meter 28 and LED 29 may all be coupled to the same point or potential wherein the point is electrically isolated from the ground of the circuit from power source 10.
The wired OR configuration of diodes 24 and 25, ensures that only the higher of output voltage signals from amplifiers 22 and 23 will be applied to both meter 28 and threshold detector 26. Meter 28 may be calibrated to provide a direct indication of the temperature of termination 11 and 12 having the higher temperature in response to the voltage provided thereto. The voltage gains of amplifiers 22 and 23 may be selected such that the voltage outputs thereof exceed the saturation voltage drop (generally about 0.6 V) of diodes 24 and 25 for termination temperatures below the protection level threshold such that meter 28 and threshold detector 26 operate in a linear voltage range. The gains of amplifiers 22 and 23 may also concurrently be selected such that the output voltages therefrom are minimized for ambient temperatures, say below about 37° C., in order to minimize current drain on battery 19 for temperatures which do not pose a potential hazard.
FIG. 2 illustrates a prong configuration which may be used with a high temperature indicating device in accordance with the present invention. For convenience, only a single prong 30 is shown. It is to be understood that generally prongs are employed in pairs.
Prong 30 comprises an elongated sheath 37 having a void 40 therein fabricated of a conductive material, such as copper or brass, and sized to conduct current from terminals 11 and 12 (FIG. 1) without undergoing a significant temperature rise, and a pair of dissimilar metal wires 32 (shown as a single wire for convenience), such as copper and constantan (55% copper, 45% nickel) or chromel™ (90% nickel, 10% chrome) (available from Hoskins Mfg. Co., Detroit, Mich.) and constantan, situated within void 40 of sheath 37 and physically isolated from each other along their length except at ends 39 where they are connected together to form a thermocouple. A material 38, such as aluminum oxide or magnesium oxide, fills void 40 of sheath 37, so as to electrically insulate wires 32 from sheath 37 and provide good thermal conductivity between thermocouple 39 and sheath 37. In order that thermocouple 39 provide an accurate temperature indication at all times, wires 32 and thermocouple 39 must be electrically insulated from sheath 37 such that currents and voltages in sheath 37 do not affect the voltage output of thermocouple 39 and do not couple signals onto wires 32. Thermocouple 39 provides a voltage output, typically less than 100 mv, proportional to its temperature. Wires 32 are connected to the input of amplifier 22 (FIG. 1). Prong 31 may be fabricated identically as prong 30 having wires 33 from the thermocouple of prong 31 connected to the input of amplifier 23 (FIG. 1).
Shown in FIG. 3 is a high temperature indicating cube tap incorporating the circuitry of FIG. 1, with like reference numbers designating like components, which provides an indication of temperature and overheating therein. In the circuitry of FIG. 3, however, prongs 30 and 31 are substituted for terminals 11 and 12 respectively, of FIG. 1. Some of the electronic components, namely, amplifiers, 22 and 23, diodes 24 and 25, comparator 26 and variable resistor 27, may be encapsulated or potted in an integral unit 14 of plastic or nylon for structural rigidity and electrical insulation from prongs 30 and 31 and female connectors 35 and 36. Terminals are provided at the margin of unit 14 to provide appropriate electrical connections for wires 32 and 33, meter 28, indicator 29 and battery 19. An adjustment access 17 coupled to variable resistor 27 is provided at the margin of unit 14 to enable the threshold of comparator 26 to be set by adjusting variable resistor 27. The entire assembly may be supported by a single piece 34 of plastic or nylon into which it is molded, ensuring that access is maintained to adjustment 17 and to battery 19 such that the battery can be replaced with a new battery when its voltage falls below a predetermined level. Meter 28 and indicator 29 are exposed for visual observation and a portion of prongs 30 and 31 protrude from supporting means 34 so as to facilitate their insertion into a duplex receptacle. Although only one pair of female connectors 35 and 36 are illustrated in the cube tap, common practice is to employ three pairs of such connectors and it will be understood by those skilled in the art that the instant invention may be employed irrespective of the number of pairs of female connectors situated in the cube tap.
In the event poor contact exists between any pair of female connectors 35 and 36 and the prongs of a male plug (not shown) situated therein and connected to a load, overheating may occur within the cube tap. Alternatively, overheating may occur if excessive loads are connected to the cube tap. In either event, overheating of the cube tap is sensed by thermocouple 39 (FIG. 2) which along with its related circuitry energizes indicator 29 to provide the user with a visual indication of excessive cube tap temperature and also activates meter 28 to provide an indication of actual cube tap temperature.
FIG. 4 illustrates a high temperature indicating device incorporating the circuitry of FIG. 1, with like reference numbers designating like components. The device senses the temperature of terminals 11 and 12 when prongs 30 and 31 are inserted into a duplex receptacle desired to be monitored for overheating. Prongs 30 and 31 may be fabricated as shown in FIG. 2 and described in conjunction therewith. The entire assembly as shown in FIG. 4 may be supported by a single piece 39 of plastic or nylon into which it is molded while ensuring that access is maintained to adjustment 17 and battery 19 as hereinbefore described. Thus all components of the circuit are surrounded and enclosed by supporting means 39 with the exception of a portion of meter 28 and indicator 29 which are exposed for visual observation and a portion of each of prongs 30 and 31 which protrude from supporting means 39 so as to permit insertion of each of them into a duplex receptacle.
In accordance with the method of the present invention, the apparatus as shown and described with respect to FIGS. 3 and 4 may be used to determine improper wiring at terminations without disassembly and before the overtemperature threshold limit (as signified by energization of indicator 29) has been exceeded. By periodically observing the highest temperature of the terminations provided by meter 28 and monitoring the current supplied to load 13 (FIG. 1), the rate of temperature rise for a known magnitude of load current may be determined. If the rate of temperature rise is greater than a predetermined limit, which limit is readily obtainable from the maximum allowable resistance of terminations or without undue experimentation, then examination of wiring integrity at the terminations is necessary. The current provided to load 13 may be measured by any conventional means such as a series or clip-on ammeter. The allowable rate of temperature rise may be calculated from an estimation of the maximum resistance allowable at the terminations and the known heating value of current (I 2 R) or may be specified by industry standards. A termination posing a potential hazard may thus be identified without need for disassembly or for gaining prior access thereto. Once a potential hazard has been identified, access to the terminations for examination and indicated corrective action may be obtained.
Thus has been described an apparatus and method for sensing overheating of current-carrying electrical conductors wherein a quantitative indication of temperature of the conductors is provided and wherein improper termination of electrical conductors is provided without need for line voltage power or disassembly to gain access to the terminations.
While only certain preferred features of the invention have been shown by way of illustration, many modifications and changes will occur to those skilled in the art. It is to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention. | Temperature indicating apparatus for sensing overheating at a pair of terminals on an electrical power line comprises a pair of thermocouples, each thermally coupled to and electrically isolated from a different one of the terminals, and a light emitting diode (LED) coupled to the output of the thermocouples through a conditioning circuit. An excessive temperature rise at either terminal causes the output voltage of the thermocouple coupled thereto to increase, thus causing the LED +o to be lit and to provide a visual indication of overheating. A meter display may be provided to show the actual temperature of the terminals in response to thermocouple voltage output. A method for determining heating at a termination without physical intervention comprises determining the rate of temperature rise of the termination for a known current therethrough and comparing the rate to a predetermined rate threshold. | 6 |
BACKGROUND OF INVENTION
1. Technical Field
The present invention relates generally to corrosion inhibition for semiconductor devices. More particularly, the present invention relates to an improved method of dicing semiconductor wafers which reduces corrosion of bonding pads.
2. Related Art
It is common in the semiconductor industry to employ aluminum to interconnect structures on integrated circuits and to form the input/output bonding pads. To improve electromigration characteristics and other properties, additives such as copper, e.g. up to 2 percent by weight, or silicon, e.g. up to 1 percent by weight, are typically incorporated into the aluminum conductors. Combinations of aluminum with several of these additives are also known in the art.
After forming the integrated circuits on a wafer, dicing or sawing of the wafer is carried out to provide chips by use of a computer-controlled dicing blade. Because the bonding pads are exposed during dicing operations, they are susceptible to corrosion. One approach to reducing corrosion during dicing, involves the use of high purity deionized water as a coolant for the dicing blade. However, this can lead to a build up of static charge, resulting in accumulation of silicon particles on the bonding pads, as well as contributing to corrosion.
In an effort to address these problems, U.S. Pub. No. US2002/0081776A1 describes affixing a sacrificial anode contacting magnesium to the dicing blade.
Another proposed technique for reducing adherence of silicon particles to bonding pads is described in U.S. Pat. No. 5,461,008, in which the pH of the deionized water is lowered to less than 5.5.
However, there still exists a need in the industry for an improved method for reducing the corrosion of bonding pads on a wafer during dicing, and an improved dicing apparatus for use in practicing the method.
SUMMARY OF INVENTION
It is against this background, that the present invention introduces an improved method for reducing corrosion of integrated circuit bonding pads during wafer dicing. In general, it has been found that this can be achieved by contacting the bonding pads with deionized water and a copper corrosion inhibiting amount of a copper corrosion inhibiting agent. It has been found that an improvement occurs by reducing or even eliminating bond pad darkening due to excessive oxide growth or by reducing or even eliminating pitting of bonding pads due to direct dissolution of localized regions of the bonding pad. Although a variety of mechanisms are believed to be responsible for producing this result, they generally involve a modification of the kinetics of oxidation or dissolution at the corroding surface or at a surface electrically connected to and cathodic with respect to the corroding surface. In accordance with the invention, the contacting is carried out continuously during the dicing operation, and preferably during cooling of the dicing apparatus.
The present invention also provides an improved dicing apparatus, which reduces corrosion of integrated circuit bonding pads on the wafer. In accordance with this aspect of the invention, deionized water and a copper corrosion inhibiting amount of a copper corrosion inhibiting agent are included in the cooling system for cooling the dicing blade of the apparatus.
An advantage that can be achieved by employing the improved method or improved apparatus of the invention is reduced product scrap, and hence reduced costs associated with scrapping product at such a late point in fabrication, i.e. in dicing operations.
The foregoing and other features and advantages will be apparent from the following more particular description of embodiments of the invention.
BRIEF DESCRIPTION OF DRAWINGS
The embodiments of this invention will be described in detail, with reference to the following figures, wherein like designations denote like elements, and wherein:
FIG. 1 is a schematic section view of a dicing blade that can be used in the practice of the invention;
FIG. 2 is an SEM micrograph showing corrosion of a bonding pad, typically encountered in the prior art; and
FIG. 3 is an SEM micrograph showing a corrosion-free bonding pad, resulting from the practice of the present invention.
DETAILED DESCRIPTION
FIG. 1 illustrates a dicing operation, in which a dicing blade or saw 1 has engaged a semiconductor wafer 2 . Typically, the dicing blade 1 is mounted to a rotatable shaft, which in turn is connected to a motor (not shown). The details of a conventional dicing apparatus are known to those skilled in the art, and a more detailed description can be found, for example, in U.S. Pat. No. 5,461,008 or U.S. Pub. No. US2002/0081776 A1, the descriptions of both of which are incorporated herein by reference. FIG. 1 also illustrates a cooling system 3 for delivering high purity or deionized water to the dicing blade 1 and the surface of the wafer 2 . The cooling system 3 is employed to cool the dicing blade 1 and the wafer 2 during a dicing operation. As also known, the wafer 2 contains numerous integrated circuit patterns, which have been defined in a predetermined manner. During dicing, the wafer 2 is cut or diced into individual chips. The integrated circuit pattern are covered with a protective coating, except at portions where bonding pads are located.
The bonding pads are usually aluminum, containing copper which is less than about 2 percent, preferably less than about 1 percent, and more preferably less than about 0.5 percent, by weight. In addition, the aluminum may contain other additives, such as, for example, silicon. Due to the presence of copper, it has been found that corrosion of the copper may occur, leading to corrosion of the bonding pads, as shown in FIG. 2 .
In accordance with the invention, corrosion of the bonding pads is substantially reduced or eliminated by contacting the bonding pads with an effective amount of a copper corrosion inhibiting agent. Preferably, the contacting is carried out continuously during the dicing operation. It is also preferred that the copper corrosion inhibiting agent be added to the cooling system, for example, by admixture with deionized water delivered to the cooling blade 1 and the surface of the wafer 2 . In carrying out the invention, minimal or no residuals occur on the wafer surface, and copper is effectively passivated at the grain boundaries of the aluminum. As a result of corrosion prevention, black stains are not visible as shown in FIG. 3 . As a particular advantage of the invention, no additional treatment or processing step is required, due to avoidance of residue on the bonding pads.
Suitable copper corrosion inhibiting agents include alkyl or alkoxy benzotriazole, mercaptobenzothiazole, alkyl or alkoxy mercaptobenzothiazole and ammonium or alkali metal salts thereof, tolyltriazole, benzotriazole, a substituted benzotriazole and/or 1-phenyl-5-mercaptotetrazole, etc.
Other suitable copper corrosion inhibiting agents include polyphosphates (acid form, or ammonium or alkali metal salt). The polyphosphates can include but are not limited to the following compounds: Methyl diphosphonic acid, aminotris (methylene phosphonic acid), ethylidene diphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, 1-hydroxypropylidene-1,1-diphosphonic acid, ethyl aminobis (methylene phosphonic acid), dodecylaminobis (methylene phosphonic acid), nitrylotris (methylene phosphonic acid) or nitrilotris (methylene) triphosphonic acid, ethylenediaminebis (methylene phosphonic acid), ethylenediamine-tetrakis (methylene phosphonic acid), hexenediamine-tetrakis (methylene phosphonic acid), diethylene-triaminepenta (methylene phosphonic acid), ammonium salts thereof, lithium salts thereof, sodium salts thereof, potassium salts thereof, rubidium salts thereof, cesium salts thereof (i.e. ammonium and alkali salts thereof), and so forth.
Additionally, suitable copper corrosion inhibiting agents include organic carboxylic acids and organic polycarboxylic acids (ammonium and alkali salts thereof). For example, such organic acids can include but are not limited to the following compounds: Citric acid, succinic acid, glutaric acid, adipic acid, malic acid, malonic acid, oxalic acid, fumaric acid, polytartaric acid compounds having the generalized formula
HO—(CRCOOHCRCOOHO) n -H
wherein each R is independently selected from the group consisting of H and C1 to C4 alkyl, n is less than 4 and the average molecular weight of the mixture corresponds to an average n in the range 1.2 to 3, erythraric-tartaric acid, polytartaric acid, L-tartaric acid, mucic acid and ammonium salts thereof, lithium salts thereof, sodium salts thereof, potassium salts thereof, rubidium salts thereof, cesium salts thereof (i.e. ammonium and alkali salts thereof), and so forth.
Further examples of suitable copper corrosion inhibiting agents, include chelation compounds, and acid forms or ammonium and alkali salts thereof. Such chelation compounds can include but are not limited to the following compounds: CDTA, trans-1,2-Diaminocyclohexane-N,N,N,N-tetraacetic acid (or a mixture of the trans and cis isomers), EDTA (ethylenediaminetetraacetic acid) and ammonium salts thereof, lithium salts thereof, sodium salts thereof, potassium salts thereof, rubidium salts thereof, cesium salts thereof (i.e. ammonium and alkali salts thereof), and so forth.
In addition, it should be understood, of course, that mixtures of suitable copper corrosion inhibiting agents can also be employed in accordance with the present invention.
Further, as noted above, it is preferred that the copper corrosion inhibiting agent be added to the cooling system, but this can be accomplished in any suitable manner, such as mixing with the deionized water in the supply line, addition to the reservoir of deionized water, etc. While many of the copper corrosion inhibiting agents can be satisfactorily added to the deionized water, it may be preferred, particularly if the copper corrosion inhibiting agent is not soluble in water, to first add it to a solvent which is miscible with water, such as an alcohol, e.g. isopropanol, then dissolve in a suitable volume of water. The resulting solution can then be added to the deionized water of the cooling system.
The amount of copper corrosion inhibiting agent that is employed can vary over a wide range, depending generally upon the exact copper corrosion inhibiting agent or mixture of agents selected, as well as the proportion of copper in the bonding pads of the integrated circuits and other features of the wafer being diced. However, an amount ranging from about 0.01 to about 200 mmoles per liter would be typical, with a preferred amount ranging from about 0.1 to about 20 mmoles per liter. In a particularly preferred embodiment of the invention, the copper corrosion inhibiting agent is benzotrizole, used in an amount ranging from about 1 to about 10 mmoles per liter. Preferably, the bonding pads are contacted with deionized water and a copper corrosion inhibiting agent for a period of time ranging from about 0.3 to about 4.5 hours, depending upon the characteristics of the wafer being diced, particularly the composition of the bonding pads.
Accordingly, the embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims. | An improved method of dicing a semiconductor wafer which substantially reduces or eliminates corrosion of copper-containing, aluminum bonding pads. The method involves continuously contacting the bonding pads with deionized water and an effective amount of a copper corrosion inhibiting agent, most preferably benzotriazole. Also disclosed, is an improved apparatus for dicing a wafer, in which a copper corrosion inhibiting agent is included in the cooling system for cooling the dicing blade. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority of the German patent application 103 37 767.0 which is incorporated by reference herein.
FIELD OF THE INVENTION
The invention concerns a method for measuring overlay shift.
BACKGROUND OF THE INVENTION
In the production of a semiconductor module, its patterns are fabricated in a variety of planes. A completed semiconductor module encompasses a plurality of planes in which the individual patterns are located. The orientation of the individual planes with respect to one another is of considerable importance. If a plane were shifted too much with respect to a previous or subsequent plane, this could result in an interruption of the connection between elements in one plane and the next. The orientation, shifting, and alignment of two successive planes is referred to as “overlay shift.” In semiconductor production, wafers are sequentially processed during the production process in a plurality of process steps. As integration density increases, requirements in terms of the quality of the patterns configured on the wafers become more stringent. To allow the quality of the configured patterns to be checked and any defects to be discovered, commensurate demands are placed on the quality, accuracy, and reproducibility of the components and process steps with which the wafers are handled. This means that in the production of a wafer, with the many process steps and many layers of photoresist or the like that must be applied, reliable and prompt detection of defects is particularly important. Equally significant for the quality of a semiconductor component is the overlay of the individual planes in the semiconductor component. It is thus particularly important that the shift of the individual planes remain within a tolerance range.
SUMMARY OF THE INVENTION
It is the object of the invention to create a method with which the overlay (the shift of successive planes) of a semiconductor substrate can be determined in simple fashion.
This object is achieved by way of a method for measuring overlay shift, comprising the following steps:
acquiring an image of at least one reference element that has at least one first pattern element in a first plane and at least one second pattern element in a second plane; traveling to at least one measurement element and acquiring an image of the measurement element; ascertaining a shift value between the reference element and the at least one measurement element by comparing the image of the reference element with the image of the measurement element; and generating an output if the shift value between the reference element and the measurement element exceeds a predefined tolerance value.
It is particularly advantageous if the following steps are performed in order to measure the overlay shift. Firstly, at least one image is acquired of a reference element that comprises at least one first pattern element in a first plane and at least one second pattern element in a second plane. Then at least one measurement element is traveled to, and an image of the measurement element is acquired. A shift value between the reference element and the at least one measurement element is then ascertained by comparing the image of the reference element with the image of the measurement element. If a predefined tolerance value is exceeded, an output to an operator is made on a user interface.
Several reference elements on one substrate can also be imaged, an average for evaluation of the measurement elements then being determined therefrom.
It is particularly advantageous if the reference element comprises a first pattern element that surrounds the second pattern element. The first pattern element and the second pattern element can each be constructed from an n-sided polygon. It is particularly suitable for determination of the overlay if the first pattern element and the second pattern element are each constructed from a regular rectangle or a square.
The operator selects a reference element, for example, via a user interface in such a way that a border is drawn around the reference element. The inspection arrangement encompasses a microscope that is equipped with a camera which acquires an image of a substrate region, of the reference element, and/or of the measurement element. The comparison of the image of the reference element with the image of the measurement element is performed by sub-pixel-accuracy pattern matching.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter of the invention is depicted schematically in the drawings and will be described below with reference to the Figures, in which:
FIG. 1 schematically depicts a system for ascertaining the overlay in semiconductor substrates;
FIG. 2 schematically depicts a user interface with which a user performs the overlay check;
FIG. 3 a is a schematic view of a first embodiment of a reference element with which the overlay is determined;
FIG. 3 b is a schematic view of the first embodiment of the reference element with which the overlay is determined, the matrix of a CCD being superimposed;
FIG. 4 a is a schematic view of the first embodiment of the reference element with which the overlay is determined, the first plane being shifted with respect to the second plane;
FIG. 4 b is a schematic view of the first embodiment of the reference element, the first plane being shifted with respect to the second plane and the matrix of a CCD being superimposed.
FIG. 5 a is a view of a second embodiment of a reference pattern or reference element with which the overlay is determined;
FIG. 5 b is a schematic view of the second embodiment of the reference pattern or reference element with which the overlay is determined, the first plane being shifted in the X direction with respect to the second plane; and
FIG. 6 is a view of a third embodiment of a pattern on the basis of which the overlay is checked.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an exemplary embodiment of an inspection arrangement 1 with which planar substrates S, for example wafers, can be investigated microscopically. In the context of the invention described here, for example, the shift of two successive planes of a wafer is investigated in order to ascertain any misalignment of the individual planes. Inspection arrangement 1 is equipped, for that purpose, with a microscope 2 . For image processing, microscope 2 can be equipped with a camera 3 having a CCD chip, the imaged microscopic subregion of the wafer being digitized.
Microscope 2 of inspection arrangement 1 can be directed onto a substrate S, in this case a wafer, located at an inspection location I. Inspection location I is enclosed by a housing 4 in which microscope 2 is simultaneously also received. Also provided in housing 4 is a conveying device 5 for transporting substrates S to and from inspection location I.
Inspection arrangement 1 furthermore encompasses a first magazine 6 for receiving several substrates S. Additionally provided is a transfer device 7 which transfers substrates S from first magazine 6 to conveying device 5 . After inspection, substrates S are collected in a second magazine 8 . A further transfer device 9 serves to transfer substrates S from conveying device 5 into second magazine 8 . Magazines 6 and 8 are preferably embodied as replaceable magazines in which substrates S are stacked one above another. Each of magazines 6 and 8 is, for that purpose, coupled separately onto housing 3 .
Inspection arrangement 1 furthermore encompasses an operating console 10 that is arranged on one side of housing 4 at operating position P. Provided for that purpose, on viewing port 12 for microscope 2 projecting out of housing 4 , are two eyepieces 14 that extend over operating console 10 .
In addition to viewing port 12 for microscope 2 , a first viewing field 16 (display) for displaying an image or image area of substrate S, and a second viewing field 18 for direct viewing of substrate S or a subregion of substrate S, are provided on housing 4 . The two viewing fields 16 and 18 are arranged at an inclination with respect to an operator 20 in such a way that operator 20 , located in front of viewing port 12 of microscope 2 , looks at the respective viewing field 16 and 18 in substantially perpendicular fashion. Also provided in housing 4 is at least one computer 22 that is also used, among other purposes, for processing the images acquired with microscope 2 .
FIG. 2 schematically depicts a user interface 22 with which a user performs the overlay check or adjusts inspection arrangement 1 for the overlay check. On user interface 22 , an overview image of substrate S is displayed in a first window 24 . Substrate S is subdivided into multiple image windows 26 that can be imaged by microscope 2 of inspection arrangement 1 . It is self-evident to one skilled in the art that the size of image window 26 depends on the selected magnification of microscope 2 . Image window 28 currently being imaged by microscope 2 is displayed on user interface 22 as a solid rectangle. The center of substrate S is identified by a cross 30 . A further cross 30 identifies an image window in which a pattern for determining the shift of two planes on substrate S is also located.
In a second window 32 on user interface 22 , an image 34 of the current image window 28 imaged by means of camera 3 of microscope 2 is displayed. The acquired image encompasses at least one reference element 36 or measurement element on which the shift of two planes with respect to one another is to be determined. Reference element 36 encompasses at least one first pattern element 36 a in a first plane 38 , and at least one second pattern element 36 b in a second plane 40 . Although the description mentions only two planes whose overlay is to be determined, this is not to be construed as a limitation. It is equally conceivable for the measurement elements or reference elements 36 to comprise more than two pattern elements that are arranged in more than two different planes. The task is thus to ascertain the shift of the individual planes with respect to one another. Operator 20 selects the reference element in such a way that a border 42 is drawn around reference element 36 . Operator 20 can do this by way of operating console 10 or a mouse (not depicted).
Provided above second and first windows 32 and 24 is a bar 44 that encompasses several click buttons 45 . Each of click buttons 45 stands for a tool that operator 20 can call. The callable tools can encompass, for example, saving, calculation, measurement, magnification selection, image acquisition, etc. User interface 22 furthermore encompasses several subregions 46 a , 46 b , 46 c , 46 d that are provided for controlling the inspection arrangement or for outputting information for operator 20 . A first subregion 46 a concerns input and output of a substrate S into inspection arrangement 1 . The data already saved in inspection arrangement 1 can also be managed here. Data already saved for overlay checks of previous substrates S can be retrieved, new data saved, or other data deleted. A second subregion 46 b concerns focus and position determination for a substrate S. Here, for example, it is possible to select between a laser focus and a TV focus. A third subregion 46 c concerns the detection and programming mode. Here, for example, the inspection arrangement can be used to program in an overlay shift that is then utilized for further measurements on substrates S of a batch. The limit values within which an overlay shift is still regarded as acceptable are defined in the programming mode. A fourth subregion 46 d concerns the inspection position. Here operator 20 can store or edit several operating positions so that inspection arrangement 1 travels to the corresponding positions on the substrate.
A control element 47 is depicted on user interface 22 below first window 24 . With control element 47 , operator 20 can displace substrate S in such a way that a specific region is imaged by microscope 2 and camera 3 . The displacement of substrate S can be accomplished with a conventional motor-controlled XYZ stage (not depicted). Also provided in the vicinity of control element 47 are several windows 48 which display, for example, the X position and Y position of the image window of substrate S that is currently located in the observation position of microscope 2 . Further windows 49 display to operator 20 the row and column on substrate S in which the image window of substrate S currently being imaged is located.
First window 24 is moreover equipped with a plurality of tabs 50 . Using the tabs, operator 20 can make selections such as Wafer Boat, Wafer Map, Statistic, Info, Gallery, etc.
FIG. 3 a is a schematic view of a first embodiment of a reference pattern or reference element 36 with which the overlay is determined. Reference element 36 encompasses at least one first pattern element 36 a in a first plane 38 , and at least one second pattern element 36 b in a second plane 40 . Note that first plane 38 lies below second plane 40 . FIG. 3 b is a schematic view of the first embodiment of reference element 36 with which the overlay is determined, a matrix 50 of a CCD of camera 3 being superimposed on reference element 36 . Matrix 50 of the CCD comprises a plurality of pixels 52 that acquire the image of reference element 36 . As compared with FIG. 3 a , FIG. 4 a depicts a schematic view of the first embodiment of reference element 36 with which the overlay is determined, first plane 38 having been shifted with respect to second plane 40 . The difference as compared with FIG. 3 a results from a shift of second pattern element 36 b in the X direction with respect to first pattern element 36 a . A shift in the X direction and Y direction is likewise possible, but is not mentioned here for reasons of simplicity.
FIG. 4 b is a schematic view of the first embodiment of reference element 36 , first plane 38 having been shifted with respect to second plane 40 , and matrix 50 of the CCD of camera 3 being superimposed. The signals of individual pixels 52 of the CCD are employed to ascertain the shift. Determination of the overlay requires the presence of at least one substrate S or wafer that comprises reference elements having either a correct alignment or a known misalignment. From that substrate S or wafer, an image of the reference element is grabbed. This has already been described in FIGS. 3 b and 4 b . For example, individual pixels 52 of matrix 50 of a CCD acquire the image of reference element 36 . Reference element 36 possesses patterns that are contained in both layers or planes whose mutual alignment is to be measured. Operator 20 must define which patterns belong to which layers. In the exemplary embodiment disclosed in FIG. 3 a , this is a so-called box-in-box pattern, and definition is performed by drawing the rectangular border 42 (see FIG. 2 ). Patterns of any desired complexity are also, however, possible as reference elements (see FIG. 5 and FIG. 6 ). For determination of a shift value between reference element 36 and the at least one measurement element, a comparison is made between the image of reference element 36 and the image of the measurement element. The comparison is performed for each of the two planes 38 and 40 by sub-pixel-accuracy pattern matching against the image of reference element 36 . Only the pattern elements of one plane or layer are searched for in each case. The misalignment M is calculated in accordance with equation 1:
M =(( A−A 0 )−( B−B 0 ))×(pixel size)+ M 0 , (Equation 1)
where A denotes the position of first pattern element 36 a in first plane 38 and B the position of second pattern element 36 b in second plane 40 of pattern element 36 ( FIG. 4 a ) in the measured image. Similarly, A 0 denotes the position of first pattern element 36 a in first plane 38 , and B 0 the position of second pattern element 36 b in second plane 40 of pattern element 36 ( FIG. 4 a ) in the reference image. M 0 is the misalignment of reference element 36 on substrate S or the reference wafer.
FIG. 5 a is a view of a second embodiment of a reference element (or reference pattern) 60 with which the overlay is determined. Reference pattern 60 comprises a plurality of first pattern elements 60 a and a plurality of second pattern elements 60 b . Reference element 60 is a comb-like pattern, first pattern elements 60 a being arranged in a first plane and second pattern elements 60 b in the second plane. Reference pattern 60 comprises a first sub-pattern 62 , a second sub-pattern 63 , a third sub-pattern 64 , and a fourth sub-pattern 65 . First and second sub-patterns 62 and 63 are arranged in such a way that longitudinal axes of first and second pattern elements 60 a and 60 b are parallel to the Y direction. Third and fourth sub-patterns 64 and 65 are arranged in such a way that longitudinal axes of first and second pattern elements 60 a and 60 b are parallel to the X direction. The depiction in FIG. 5 a shows reference pattern 60 in which no shift exists between the first and second planes.
FIG. 5 b is a schematic view of the second embodiment of reference pattern (or reference element) 60 with which the overlay is determined, the first plane being shifted in the X direction with respect to the second plane. The shift is evident from the fact that in first and second sub-patterns 62 and 63 , second pattern elements 60 b are shifted more toward first pattern elements 60 a . In third and fourth sub-patterns 64 and 65 , second pattern elements 60 b and first pattern elements 60 a are pulled apart in the X direction relative to one another. The magnitude of the shift is determined, as in the first exemplary embodiment, with sub-pixel accuracy.
FIG. 6 is a view of a third embodiment of a pattern on which the overlay of a first and a second plane is checked. Any pattern on a substrate S or wafer that has defined pattern elements in different planes is suitable for overlay checking. In the exemplary embodiment depicted in FIG. 6 , reference pattern 70 comprises a first pattern element 70 a and a second pattern element 70 b . First pattern element 70 a comprises a flat portion 72 and an angled extension 73 . First pattern element 70 a is arranged in a first plane. Adjoining the first pattern element is a second pattern element 70 b that extends substantially parallel to the X direction. The second pattern element is arranged in a plane that differs from the first plane. A shift of the first plane with respect to the second would result, in this embodiment, in a defective transition from first pattern element 70 a to second pattern element 70 b. | A method for measuring overlay shift is disclosed. An image is acquired of at least one reference element that comprises at least one first pattern element in a first plane and at least one second pattern element in a second plane. An image of a measurement element is likewise acquired. The shift value between the reference element and measurement element is ascertained by comparing the image of the reference element with the image of the measurement element. An output on a user interface indicates whether a predefined tolerance value is being exceeded. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present Application claims the benefit of priority as a continuation of U.S. patent application Ser. No. 11/515,080. titled “Vehicle Barrier System” filed on Sep. 1, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 10/897,417, titled “Vehicle Barrier System” filed on Jul. 21, 2004, which issued on Oct. 31, 2006 as U.S. Pat. No. 7,128,496, the disclosure of which are hereby incorporated by reference.
FIELD
The present invention relates to an installed vehicle barrier system that protects at-risk sites from vehicle born attacks. The present invention of the barrier system uses a combination of a number of vehicle attenuating devices to prevent the passage of vehicles. These devices include a traffic control zone, followed by a first impact element that is backed by a bed of deformable material, and followed by a second impact element.
BACKGROUND
Barriers for restricting the passage of vehicles (such as automobiles, trucks, busses, airplanes and the like) are generally known. Barriers that are fixed in the roadway, meaning they do not move by device or mechanism, are typically categorized as “passive” or “inoperable” barriers. These types of barriers are either removably placed on the roadway or sidewalk surrounding an at-risk site, or they are installed into the ground or built into the landscape/streetscape. Known installed “passive” barriers typically include foundation walls (typically at least 36″ high), or bollards in the form of “posts” embedded in a concrete foundation, and beds of a crushable material (such as concrete). Walls and bollards are intended to stop vehicles through impact resistance, having sufficient shear strength to remain intact at impact and relying on the inertia of their foundations to bring a vehicle to a halt.
In addition to vehicle barrier systems, vehicle arresting systems are also known. Where vehicle barrier systems are intended to immediately stop a vehicle, vehicle arresting systems are intended to control the stopping of a vehicle over a given time and/or distance. Known arresting systems include beds of a crushable material (such as concrete), fences and gates, and cable and elastic (e.g. “bungee cord”) systems. Crushable beds tend to utilize the interaction between the bed and the tire(s) of the vehicle. As a vehicle moves across the crushable material, the weight of the vehicle causes it to sink into the bed. At the same time, the spinning of the tire “rips” through the crushable material. As the vehicle drops farther into the bed, the tires' rotation tends to become slower until finally the vehicle is stopped. For example, crushable beds at the ends of aircraft runways for aircraft that “overshoot” the runway are generally known for gradually decelerating the aircraft over an extended distance to minimize injury to occupants and damage to the aircraft. Examples of such crushable bed systems are described in U.S. Pat. Nos. 5,885,025; 5,902,068 and 6,726,400.
These known vehicle barriers present a number of functional problems. Walls significantly impede pedestrian traffic and can cause pedestrian “herding” and “bottle necking.” Additionally, walls, and bollards as well, are somewhat visually restricting. The inherent height of the two, that is necessary for their function as a vehicle barrier, reduces the visual “openness” of the landscape/streetscape. Crushable beds are not optimal because they typically require an extended length of the crushable bed (upwards of 50 feet or more) to arrest a vehicle (and substantially longer for aircraft and the like). Such long lengths are generally not compatible with most urban applications, where space between a roadway and a building line or perimeter line is fairly small (e.g. 5-30 feet) and a primary objective of the barrier is to stop the progress of the vehicle within a relatively short distance. Such known vehicle barrier systems tend to provide limited application and flexibility to designers in providing an effective vehicle barrier system intended to meet applicable government performance standards, and is minimally obtrusive, for use in areas such as urban settings that typically have limited space for installation of such barriers.
Accordingly, it would be desirable to provide an installed vehicle barrier system or the like of a type disclosed in the present Application that include any one or more of these or other advantageous features:
1. A system providing a barrier that is resistant to unauthorized breach by vehicles. 2. A system that minimizes the restriction of pedestrian traffic flow. 3. A system that provides a less visually obtrusive installed vehicle barrier system. 4. A system that stops a vehicle in the short distance between a roadway and the protected site. 5. A system that rapidly arrests a vehicle without regard to vehicle damage. 6. A system that is integrated into the landscape/streetscape, employing similar elements such as curbs, sidewalks, benches, etc. 7. A system that combines a trafficable roadway surface, a curb, a bed of compressible material covered by a surface cover layer, and a low wall line or low bollard line. 8. A system in which the required height of the impact element line is interdependent with the characteristics of the bed of compressible material, so that the various components of the system may be adjusted to suit the needs of a particular application.
SUMMARY
One embodiment of the present invention relates to a barrier system for use between a roadway and a site requiring protection from advancing vehicles. The system includes a trafficable surface and a first impact element (such as a “curb” as typically included along an edge of a trafficable surface). The trafficable surface may include certain features to reduce the speed of an approaching vehicle before reaching the first impact element. Such features include frictional elements and barriers arranged to create traffic flow patterns. Vehicles that reach the first impact element will have their trajectory redirected upwardly from impact with the curb. Beyond the first impact element is a deformable bed intended to lower the elevation of a vehicle that encounters the bed by including a material or infrastructure configured to collapse, breakaway, crush, compress, yield or otherwise deform under the weight of the vehicle when the vehicle descends onto the bed after impacting the first impact element. The bed may be contained in a confining structure such as a foundation and topped by a surface cover layer at a substantially equivalent elevation with the top of the first impact element, configured to spread the weight of loads due to pedestrian and the like. Beyond the bed a second impact element in the form of an impact element line extends upwardly from grade level, separating the barrier system from a protected zone adjacent to a site requiring protection. The components of the system may be flexibly adapted in various combinations to suit installation in a particular application while providing performance that is consistent with applicable barrier performance standards.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a top view of the vehicle barrier system according to an embodiment.
FIG. 2 is a schematic representation of a sectional view of the vehicle barrier system according to the embodiment of FIG. 1 .
FIG. 3 is a schematic representation of a sectional view of a vehicle impacting the first impact element of the vehicle barrier system of FIG. 1 and FIG. 2 .
FIG. 4 is a schematic representation of a sectional view of a vehicle jumping as a result of impacting the first impact element of the vehicle barrier system of FIG. 1 and FIG. 2 .
FIG. 5 is a schematic representation of a sectional view of a vehicle entering the compressible bed of the barrier system of FIG. 1 and FIG. 2 .
FIG. 6 is a schematic representation of a sectional view of a vehicle impacting the impact element line of the barrier system of FIG. 1 and FIG. 2 .
FIG. 7 is a schematic representation of a top view of the vehicle barrier system according to another embodiment.
FIG. 8 is a schematic representation of a sectional view of the vehicle barrier system according to the embodiment of FIG. 7 .
FIG. 9 is a schematic representation of a top view of a vehicle barrier system according to another embodiment.
FIG. 10 is a schematic representation of a sectional view of the vehicle barrier system according to the embodiment of FIG. 9 .
FIG. 11 is a schematic representation of a sectional view of a variation of the vehicle barrier system according to the embodiment of FIG. 9 .
FIG. 12 is a schematic representation of a sectional view of another variation of the vehicle barrier system according to the embodiment of FIG. 9 .
FIG. 13 is a schematic representation of a sectional view of another variation of the vehicle barrier system according to the embodiment of FIG. 9 .
FIG. 14 is a schematic representation of a sectional view of another variation of the vehicle barrier system according to the embodiment of FIG. 9 .
FIG. 15 is a schematic representation of a sectional view of another variation of the vehicle barrier system according to the embodiment of FIG. 9 .
FIG. 16 is a schematic representation of a sectional view of another variation of the vehicle barrier system according to the embodiment of FIG. 9 .
DETAILED DESCRIPTION
According to the illustrated embodiments, the vehicle barrier system provides an arrangement or combination of installed, vehicle arresting and barrier devices to be used along a security perimeter to create an area 5 protected from vehicle intrusion (e.g. to provide protection of facilities, buildings, restricted areas, etc.). This arrangement of vehicle arresting and barrier devices is intended to stop vehicles within a relatively short distance traveling at varying rates of speed, according to pre-established crash barrier rating systems and/or criteria. The vehicle barrier system is shown composed of a combination of distinct regions (shown for example as four regions). A vehicle attempting to breach the security perimeter may progressively encounter all four of these regions and each region, in turn, is intended to reduce the vehicle's speed or control the vehicle's approach and thus reduce its speed.
A first region includes a trafficable surface (e.g. asphalt, concrete, paving, etc.) using friction and/or traffic patterns to slow the vehicle (e.g. traffic patterns, friction elements, etc.), as the surface material can have a higher coefficient of friction than a traditional asphalt roadway. After encountering the first region, the vehicle may encounter a second region.
The second region includes an upwardly extending first impact element 2 (e.g. a fixed barrier, or vertical element, shown for example as a “curb,” etc.) disposed at the edge of the trafficable surface 1 or other desired location. The curb 2 is intended to reduce the vehicle's speed through inertial impact resistance. The curb 2 also serves to cause the vehicle to be directed at least partially upward (e.g. “jump”), where the vehicle's front wheels temporarily lose contact with the trafficable surface as the vehicle's trajectory is redirected upwardly from the impact with the curb. After the vehicle impacts the curb 2 , the vehicle moves upward and forward and descends upon a third region.
The third region includes a deformable zone 3 . The deformable zone 3 is intended to lower the elevation of the vehicle below the top of curb 2 by providing a bed 9 having an infrastructure or material that is configured to collapse, breakaway, crush, compress, yield or otherwise deform under the weight of the vehicle when the vehicle descends onto the bed after impacting the curb (see FIGS. 5-6 ). According to a preferred embodiment, the bed 9 of the deformable zone 3 has a length 15 within a range of one foot to thirty feet, and a depth 17 having any suitable depth for containing a deformable infrastructure or material intended to lower the elevation of a vehicle that encounters bed 9 by a sufficient amount so that a structural portion of the vehicle contacts the impact element line in the event that the vehicle traverses the entire length 15 of bed 9 . However, the length and depth may have any suitable dimensions for use in combination with a curb 2 and impact element line 4 for installation in a particular application. The deformable zone 3 is shown to include a cover surface layer 7 (e.g. paving, concrete, sedum, planting, soil, etc.) disposed on the surface of bed 9 . The cover surface layer 7 is intended to spread relatively smaller bearing loads (e.g. pedestrian, horse, carts, handtrucks, etc.), so as not to substantially deflect (or otherwise fail) under such loads or deform the deformable infrastructure or material of bed 9 below. The cover surface layer 7 is designed to fail under higher bearing loads and higher impact loads resulting from vehicles (e.g. automobiles, trucks, buses, etc.) having a sufficient weight (e.g. weighing at least approximately 2,500 lbs, and either crack (in the case of, for example, concrete, paving, etc.) or deflect (in the case of, for example, sedum, planting, etc.) so that the vehicle's weight bears on the deformable infrastructure or material of bed 9 below.
According to a preferred embodiment, the bed 9 comprises a deformable structure (e.g. lattice, honeycomb, etc.) constructed of metal, polycarbonate, plastic, composite metal, wood, etc. and configured to breakaway, collapse, crush, sink or otherwise deform under the weight of the vehicle. The bed 9 may also comprise a material (e.g. uniform or composite), alone or in combination with a structure, having characteristics that permit the material to crush, compress, yield, displace, or otherwise deform, such as, for example, cellular concrete, metallic foam, synthetic foam, or any other suitable material of combination of such materials, having a predefined compression strength, sufficient to crush under a tire(s) of a vehicle weighing at least approximately 2,500 pounds (lbs). The vehicle's weight combined with the rotation (e.g. “spinning” etc.) of the vehicle's tires is intended to deform (e.g. collapse, crush, compress, yield, displace, etc.) the deformable structure or material 9 , so that the elevation of the vehicle “drops” or is otherwise “lowered.” The deformation of the structure or material of bed 9 tends to lower the effective height of the vehicle, as the elevation of the vehicle decreases (e.g. sinks, falls, etc.) into the bed 9 , as well as reducing the vehicle's speed, due at least in part to the friction between the tires and the compressible structure of material. The desired deformability (e.g. strength, compressibility, etc.) of the structure or material of bed 9 will generally be determined by the length 15 of bed 9 and the height 16 of the impact element line 4 (shown for example as a low wall, etc.) backing the bed, on a case-by-case basis considering the available length for placement of the bed and the available height for the impact element line 4 . For example, if the area available for the bed is relatively short, then there will be a relatively small “drop” in elevation of the vehicle within the bed (as the vehicle traverses the length of the bed) and the impact element line 4 (e.g. wall, bollard, etc.) should be relatively high (e.g. sufficient to contact a structural portion such as a chassis of the vehicle, accounting for the relatively small drop in elevation of the vehicle within the bed). Conversely, if the area available for the bed is relatively long, then there will be a correspondingly greater “drop” in elevation of the vehicle within the bed (as the vehicle traverses the length of the bed) and the impact element line (e.g. a wall, bollard, etc.) may be correspondingly lower (or in certain cases, for example, essentially non-existent) such that the height or elevation of the impact element line 4 remains sufficient to contact the chassis of the vehicle to prevent further progress of the vehicle into the protected zone 5 .
The deformable zone 3 of the third region also includes a confining structure 8 for containing the bed 9 . The confining structure (e.g. a concrete foundation, metal trough, wood form-work, fabric mesh, etc.) is shown to surround the deformable structure of material of bed 9 , holding it in place, so that when the bed 9 is “loaded” it deforms and the deformed structure of material of the bed 9 is generally contained by the confining structure 8 . After encountering the third region having the deformable zone 3 , the vehicle may encounter a fourth region in the even that the vehicle traverses the length 15 of bed 9 .
The fourth region is shown located beyond the compressible zone, and includes an impact element line 4 . The impact element line (comprised of, for example, walls, bollards, posts, planters, projections, obstacles, etc.) is shown to have a sufficient height to impact a structural portion (e.g. the chassis, etc.) of the vehicle once the vehicle has dropped in elevation due to deformation of bed 9 of the deformable zone 3 . The resistance provided by the impact element line 4 is intended to be sufficient to stop any consequential progress of the vehicle after encountering the trafficable surface 1 , the curb 2 , and the bed 9 , so that the vehicle does not enter the area 5 to be protected.
In the wall or line construction of conventional vehicle barriers (e.g. “anti-ram” type, etc.) impact elements are typically specified as having a height of approximately three (3) feet tall, above a finish grade elevation. For example, in the case of the U.S. Department of State (DOS), a generally recognized national authority on vehicle barrier rating and authorization, “passive anti-ram” type impact barriers are specified to have heights within the range of 30-39 inches tall, (such as described in DOS design specifications DS-1, DS-7, and DS-50 for use with a “rigid” trafficable surface (e.g. roadway, etc)). According to the illustrated embodiment of the present invention, the height 16 of the impact element line 4 may be “lowered” or reduced by an amount corresponding to the deformability (e.g. compressibility, etc.) characteristics of the bed 9 . The greater the deformability of the material, the greater the degree of deformation and corresponding “drop” in elevation of the vehicle when the vehicle encounters bed 9 . As the bed's capability to deform (e.g. collapse, breakaway, compress, crush, yield, etc.) and thus lower the elevation of a vehicle increases, the height 16 of the impact element line 4 necessary to contact the chassis of a vehicle tends to decrease. The deformability of bed 9 serves to lower the effective height of a vehicle prior to encountering the impact element line 4 . As the approaching vehicle encounters the bed 9 , it drops below the grade of trafficable surface 1 or the height of curb 2 (based on a particular application), as its wheels “grind” through or deform the structure or material of bed 9 and the vehicle's inherent weight causes the material to deform under the bearing load of its wheels. As a result, in the event that the vehicle has traversed the length 15 of bed 9 and reached the impact element line 4 , the elevation of the vehicle has been lowered in relation to the finish grade and the height 16 of the impact element line 4 . The reduction in elevation of the vehicle is believed to be attributable to the length 15 of bed 9 and to the strength characteristics (e.g. yield, compressibility, deformability, etc.) of the structure or material of bed 9 .
According to a preferred embodiment, the length 15 of bed 9 , and the deformability of the structure or material and the height 16 of the impact element line 4 are related in an interdependent relationship and may be combined in a wide variety of combinations and permutations to accomplish the intended objective of providing an effective barrier system that is suitable for use in locations with reduced space and that provides an aesthetically and architecturally pleasing appearance. As previously described, a typical minimum height of a conventional “anti-ram” type impact element for use in connection with a conventional roadway is approximately three (3) feet. The use of the bed 9 in connection with the curb 2 and the impact element line 4 permits the height 16 of the impact element line 4 to be reduced below the conventional standard of three (3) feet, by an amount generally corresponding to the “drop” in vehicle elevation resulting from the length 15 and or the strength characteristics of the structure or material of bed 9 . For example, if the strength of the structure or material of bed 9 is increased, then the length 15 of the bed and/or the height 16 of the impact element line 4 can be increased accordingly. Likewise, as the strength of the structure or material of bed 9 is reduced, then the length 15 of bed 9 and/or the height 16 of the impact element line 4 may be reduced. According to a preferred embodiment, the height 16 of the impact element line 4 for use in combination with bed 9 and the curb 2 is within a range of approximately six (6) inches to thirty (30) inches, however, other heights of the impact element line above the finish grade elevation may be used to suit an installation for a particular application, such as within a range of approximately zero (0) inches above grade to several feet or more above grade.
According to any preferred embodiment of the present invention, the interaction of the length 15 of bed 9 , and the strength characteristics of the structure or material of bed 9 , and the height 16 of the impact element line 4 is intended to provide an adaptable barrier system configured to ensure that the chassis of any vehicle that traverses the length 15 of bed 9 will come in contact with the impact element line 4 . The barrier system of the present invention is intended to avoid the use of conventional approaches that include high walls, large impact elements and/or long expanses of crushable material. The embodiments of the present invention disclosed herein are intended to provide an adjustable and adaptable system comprising combinations of “stages” or “layers” of protective elements that provide flexibility to designers for adaptation to various applications having needs such as small installation areas, required pedestrian access, or when the barrier system is desired to be unobtrusive and to minimize the appearance of the barrier from detracting from (or drawing attention from) the surroundings.
In conventional barrier applications involving a “rigid” trafficable surface, the typical height of an impact element that is necessary to contact the chassis for most “high threat” type vehicles is approximately 18 inches. Accordingly, the Applicants believe that the height of an impact element line used in combination with a bed of a deformable structure or material according to the present invention, may be reduced by an amount corresponding to the drop in elevation experienced by the vehicle as it traverses the bed. For example, if a bed of a deformable structure or material is configured to provide a drop in elevation of the vehicle by twelve (12) inches, then the height of the impact element line may also be generally reduced by a corresponding twelve inches, in order to maintain the height of the impact element line at an effective height of 18 inches with respect to the vehicle.
Referring to FIGS. 1 and 2 , the vehicle barrier system 11 is shown according to one embodiment. The system is shown to include a trafficable surface 1 , over which all vehicles can generally pass. A first impact element shown for example as curb 2 lies along the trafficable surface 1 and is backed by a compressible zone 3 and a second impact element shown as an impact element line 4 . The impact element line 4 is shown to separate the barrier system from the protected region 5 . Beyond the protected region 5 is shown the asset 12 (e.g. building, etc.) that is intended to be protected by the barrier system. The trafficable surface 1 may form a part of the barrier system by modifying its surface through addition of frictional elements (e.g. paving, aggregates, etc.) that allow it to contribute to the attenuation of an advancing vehicle.
According to a preferred embodiment as shown in FIGS. 7 and 8 , the first region including trafficable surface 1 can be comprised of three distinct sub-regions. Trafficable surface 1 A is separated by a generally upright impact element (shown as a vertical element line 1 B) from trafficable surface 1 C. In this embodiment, vertical element line 1 B (e.g. wall, bollard line, wall segment line, median, curb, tree line, planter, line of benches, etc.) serves to reduce the speed of vehicles attempting to breach the barrier system. The vertical element line 1 B tends to reduce a vehicle's speed by “forcing” a vehicle to drive around the vertical element, causing the vehicle to reduce speed to maintain steering, or to drive through the vertical element, causing the vehicle to reduce speed through impact or vehicle damage or destruction. Additionally, trafficable surfaces 1 A and 1 C can be modified through addition of a frictional element (e.g. paving, aggregate, etc.) that is intended to improve the ability of the trafficable surfaces to contribute to the reduction in speed of an advancing vehicle.
In the embodiment shown in FIGS. 1 and 2 , trafficable surface 1 can also be modified to become a vehicle attenuating device by changing the surface composition to a material (e.g. pavers, concrete or asphalt with added aggregates such as sand or stone, etc.) that has a higher coefficient of friction than a standard roadway wearing course. The curb 2 is intended to reduce the speed of the vehicle through impact, and also cause the vehicle to “jump”. According to the embodiment, when the vehicle reaches the deformable zone 3 , it not only bears on bed 9 , but it also descends upon the surface cover layer 7 and bed 9 with a generally vertical impact force, (as shown schematically in FIG. 5 ). The first impact element in the form of the curb 2 may be formed of stone, reinforced concrete, wood, etc. As well, the curb may be capped with steel and/or pinned to a foundation below (not shown) for additional strength. According to a preferred embodiment, the curb 2 has a height that is typically in a range of approximately 3 inches to 12 inches high above the level of the trafficable surface, but may be provided with any suitable height for use with a barrier for intended vehicle types.
According to the illustrated embodiment the deformable zone 3 comprises a surface cover layer 7 , a bed 9 having a deformable structure or material for lowering the elevation of the vehicle, and a confining structure 8 . The top of surface cover layer 7 (e.g. formed from a material such as concrete, brick, pavers, tiles, cobble, planting, soil, sedum, sand, wood, plastic, etc.) is shown at approximately the same elevation as the top of the curb 2 . Surface cover layer 7 serves to spread relatively small bearing loads so that bed 9 , below, does not substantially deform, thus allowing pedestrians and the like (e.g. horses, light vehicles such as golf carts, hand trucks, etc.) to travel over this region of the vehicle barrier system without deforming the structure or material of bed 9 below. According to a preferred embodiment, the structure or material of bed 9 is designed to fail (e.g. deform, crush, collapse, compress, breakaway, yield, deflect, etc.) under loads generally equal or greater to the loads created by the tires of a vehicle having a weight of approximately 2,500 lbs. According to alternative embodiments, the bed may be configured for suitable deformation with vehicles having other loading conditions as determined in a particular application.
According to one preferred embodiment the bed 9 comprises a compressible material formed from cellular concrete having a compression strength within the range of approximately 30 pounds per square inch (psi) to 60 psi and formed with a substantially uniform density, such as may be commercially available from the Engineered Arresting Systems Corporation of Aston, Pa. According to an alternative embodiment, the compressible material may be other suitable materials (e.g. wood, plastics, metallic and/or polymeric materials, etc.) that are configured to crush or collapse under a predetermined loading condition, or may have different or other strength characteristics, or may have variable density (such as by containing voids of air ranging in sizes from small to large). For example, the material may be a metallic or polymeric material formed with a plurality of voids therein, such as a metallic foam or synthetic foam material, or any suitable combination of such materials and configured to compress or crush under predetermined loading conditions. By further way of example, the bed may comprises a structure configured to deform under predetermined loading conditions, such as a framework, lattice, honeycomb, or other deformable support structure and constructed of any suitable material such as metal, polycarbonate, plastic, composite metal, etc. According to other alternative embodiments, the material may be a generally incompressible material that is configured to deform under certain predetermined loading conditions, such as a liquid, slurry, gel, or other suitably deformable material.
The bed 9 is shown contained by a confining structure 8 . According to a preferred embodiment, the confining structure is provided in the form of a reinforced concrete foundation (e.g. trench, pit, etc.). According to other embodiments the confining structure may be formed from a metal trough, wood form-work, fabric mesh or other suitable material. The confining structure 8 is intended to retain the structure or material of bed 9 so that when the structure or material deforms, the confining structure 8 restrains the structure or material. For example, when the material comprises a cellular concrete material, the material crushes “in place,” thus the need for “empty pockets” in the confining structure and other supporting foundations (not shown), to accommodate for any displaced material can be minimized or avoided.
Referring to FIGS. 3-6 the impact element line 4 is shown as a “foundation” type impact element where the structure of the impact element extends below grade and “links” (or is otherwise coupled) to a relatively significant subsurface foundation such as, for example, the confining structure 8 , a building foundation, or the like). Such foundation type impact elements are intended to provide a relatively “heavy” ballast material below grade to minimize the volume of the impact elements above the trafficable surface, thus increasing the ease of pedestrian access and minimizing visual obstructions along the security perimeter.
According to one embodiment, the impact elements are “bollards” formed from a shell of material (e.g. steel, etc.) having a cavity containing a fill material (e.g. cement, reinforced concrete, metal, stone, wood, plastic, etc.). The shell may include internal braces (not shown), such as steel plates, to provide additional strength. The shell and fill material may be integrally formed with a foundation below grade so that loading from vehicle impact upon the impact elements can be transferred to the foundation. Use of foundation type barriers are generally desirable for installed “permanent” type barrier systems, in which the impact elements are intended to be present for an extended time period. According to one embodiment the foundation impact elements include a steel shell filled with reinforced concrete and having a minimum cross section area of approximately 144 square inches. According to an alternative embodiment, the foundation impact element line is a wall or line of wall sections having a thickness up to and including approximately 12 inches. In the embodiments where the impact elements of the impact element line 4 are bollards or walls, the height of said impact elements is intended to be smaller than the typical 30 inch height of most conventional vehicle “anti-ram” type barriers. The height of the impact element 4 may be lower than a typical “standard height” barrier because the impact elements are backing the deformable zone 3 that tends to lower the effective height of threatening vehicles. According to an alternative embodiment, the impact elements may be provided in various shapes, sizes and materials. For example, the cross sectional area may be decreased with the use of higher strength materials or the cross sectional area may be increased with the use of lower strength materials, etc. According to another alternative embodiment where the impact element line is made up of bollards, the bollards may be connect by beams (e.g. steel, concrete, reinforced concrete, wood, etc.). According to a further alternative embodiment where the impact element line is made up of bollards connected or linked by beams or low walls, these impact elements may be covered in a suitable pedestrian seating material (metal, wood, concrete, glass, etc.) and used as a bench or other suitable article.
According to a particularly preferred embodiment the trafficable surface 1 (e.g. roadway, parking lot, etc.) includes trafficable surfaces 1 A and 1 C separated by a vertical element 1 B. Vertical element 1 B is shown as a low concrete wall configured to separate traffic from surfaces 1 A and 1 C. Surfaces 1 A and 1 C may be formed from standard roadway asphalt or the like. The first impact element in the form of a curb 2 is preferably a granite curb that is “pinned” to a foundation below the trafficable surface 1 . The curb 2 preferably extends approximately six (6) inches above the grade of the trafficable surface 1 , and is six (6) inches in length. The foundation is shown continuous with the confining structure 8 that contains the structure or material of bed 9 . The confining structure 8 is preferably a reinforced concrete foundation having a depth 17 that is approximately four (4) feet deep. Contained in the concrete foundation of the confining structure 8 is a deformable material preferably made from a crushable cellular concrete material having a compressive strength within a range of approximately 30-60 psi. The bed 9 preferably has dimensions of approximately 48 inches in length, 36 inches in depth, and may have any suitable width to accommodate the intended application. Above the bed 9 having the deformable material is shown the surface cover layer 7 . Surface cover layer 7 is preferably made from stone pavers or the like and has a depth of approximately three (3) inches. As shown in FIGS. 3-6 , the top of the surface cover layer 7 is preferably at approximately the same elevation as the top of curb 2 . Beyond the bed 9 is shown the impact element line 4 . Impact element line 4 preferably comprises either a low wall formed from one or more sections extending approximately sixteen (16) inches above the top of cover layer 7 , and having a length of approximately twelve (12) inches and may have any suitable width corresponding to the width of bed 9 . Alternatively, the impact element line may formed from rows of bollards comprising steel shells containing concrete or the like and having a diameter within the range of approximately twelve (12) inches to sixteen (16) inches, and a height of approximately sixteen (16) inches above the surface layer. According to the embodiment, the bollards are configured in groups of at least two and spaced at intervals of approximately 48 inches on center.
According to another preferred embodiment the first impact element 2 is a granite curb that is “pinned” to a foundation below grade. The curb 2 extends approximately six (6) inches above the trafficable surface 1 , and is approximately six (6) inches in length. The foundation is preferably substantially continuous with the confining structure 8 that contains the structure or material of bed 9 . The confining structure 8 is preferably a reinforced concrete foundation that is approximately 48 inches deep. Contained in the concrete foundation 8 is the bed 9 having a deformable material preferably made from crushable cellular concrete or the like and having a compressive strength within the range of approximately 30-60 psi. The bed 9 preferably has dimensions of approximately 20 feet in length, 36 inches in depth, and variable width to accommodate the intended application. Shown above bed 9 is the surface cover layer 7 that is preferably a sedum planting or the like, such as typically used in green roof installations, etc. and having a depth of approximately two (2) inches. As shown in FIGS. 3-6 , the top of the surface cover layer 7 is configured at approximately the same elevation as the top of curb 2 . Behind the bed 9 and cover layer 7 is the impact element line 4 that preferably includes a low wall extending approximately sixteen (16) inches above the top of the cover layer, and having a length of approximately twelve (12) inches and a width corresponding to the width of at least one of the bed, the cover layer 7 , and the foundation 8 . According to alternative embodiments, the dimensions of the curb, and the bed, and the confining structure and the impact element line may be varied to suit a particular application.
The impact element line 4 of the vehicle barrier system 11 may also be provided as “inertia” or “friction” type barriers that are intended to rely on their weight and friction with the surface on which they are placed to provide a desired degree of impact resistance. Such inertia type impact elements may be “preformed” concrete structures (such as commonly known as “jersey barriers”) or concrete “planters” or the like that are intended for placement at a desired location. The inertia type impact elements are advantageous for “temporary” type barrier systems, in which the impact elements may only be required for a relatively short time period, or where subgrade conditions prevent easily constructing a foundation, as in the case of shallow depth utility lines, etc.
According to another embodiment of the vehicle barrier system as shown in FIGS. 9 , 10 and 16 , a sidewalk 120 is disposed between the curb 102 and a bed system 103 . The bed system 103 comprises a composite, multi-layer arrangement of materials or structure intended to arrest the progress of a vehicle, yet permit unimpeded pedestrian traffic in a pedestrian area. For example, the bed system 103 is shown to comprise a first layer, shown as a deformable material layer 109 and a second layer, shown as a pedestrian cover surface material layer or structure 107 , substantially overlying a deformable material layer or structure 109 . The sidewalk 120 is intended for pedestrian traffic, but may support incidental vehicular traffic. Typical construction for the sidewalk 120 involved a decorative paving layer (e.g. cobble, stone, brushed concrete, soil, gravel, asphalt, etc.) over compacted earth with or without a concrete sub-base in between. The sidewalk 120 serves to provide a buffer zone between the trafficable surface 101 and the bed system 103 , so that incidental vehicular traffic adjacent to the trafficable surface 101 does not disturb the deformable structure or material layer 109 of the bed system 103 . The sidewalk 120 may be constructed to building code standards for sidewalks or terraces subject to vehicular traffic, as indicated in building codes such as the New York City Building Code or the International Building Code, where such a sidewalk would typically be required to have a Minimum Uniform Live Load capacity of 250 pounds per square foot (psf) or Minimum Concentrated Live Load requirement of 8,000 lbs. In this embodiment the curb 102 may be used, as in previous embodiments, to direct a potential threat vehicle upwards so that it descends into the bed 103 . According to a preferred embodiment, the curb has a height that extends within a range of substantially one (1) inch to ten (10) inches above the trafficable surface. Under other scenarios, the curb may not serve to direct the vehicle upwards, for example, in the case where a vehicle's speed might not be high enough or its suspension calibrated so that the vehicle's wheels do not lose contact with the trafficable surface 101 , curb 102 , or sidewalk 120 . In this scenario, the curb would serve as a visual indicator to vehicle drivers, signaling the end of the trafficable zone and the beginning of the pedestrian sidewalk 120 .
In related embodiments, as shown in FIGS. 11 , 12 , 13 , 14 , and 15 the curb 102 is replaced with a visual indicator element 121 . The visual indicator element 121 provides a recognizable cue to the driver of a vehicle of the delineation of the trafficable surface 101 and the pedestrian sidewalk 120 . The visual indicator element 121 is shown as generally flush (e.g. having a substantially equivalent top elevation) with both the trafficable surface 101 and the pedestrian sidewalk 120 . The visual indicator element 121 alerts drivers through a difference in appearance such as painting or markings (e.g. in pattern(s), distinctive color scheme, etc.) or having a distinct material and/or texture (e.g. stone, concrete, wood, metal, etc.) from the surrounding paving conditions of the trafficable surface 101 and the sidewalk 120 .
In a preferred embodiment the confining structure 108 of the bed system includes retaining walls 122 (e.g. formed from reinforced concrete, stone, sheet metal, wood, compacted soil, masonry, etc. or any suitable combination). These walls 122 serve to separate the deformable material layer 109 from the surrounding sub-grade condition (e.g. soil, sand, concrete, utility lines, etc.). In related embodiments, the walls are defined as having four (4) or more distinct sides (i.e. front 122 A, left 122 B, right 122 C, and rear 122 D). Accordingly, the rear wall 122 D is intended to bear the impact of a vehicle that has traversed the bed system 103 , broken through the pedestrian cover surface layer 107 , and deformed the deformable material layer or structure 109 (such as described in previous embodiments as being performed by the impact element line 4 ). The rear wall 122 D is designed to stop (e.g. arrest, halt, disable, etc.) a vehicle that impacts it (as described in previous embodiments). In some embodiments, such as those indicated in FIGS. 10 , 11 , 12 and 15 , the top of the rear wall is shown at an elevation substantially equivalent with the top of the pedestrian cover surface layer 107 . In other embodiments, such as shown in FIG. 13 , the height of the top elevation of the rear wall 122 D is above the top elevation of the pedestrian cover surface layer 107 (such as, but not limited to, a height within the range of approximately 0-24 inches above the pedestrian cover surface). In this embodiment, the rear wall 122 D can be equipped with an architectural cover (e.g. bench, wall, curb, etc.) of unique material (stone, metal, glass, wood, composite, polymer, etc.) in order to enhance its aesthetic appearance. In other embodiments, such as FIG. 14 , the top elevation of the rear wall 122 D is below the top elevation of the pedestrian cover surface layer 107 . The relative elevation of the rear wall 122 D is determined by the expected elevation of a potential attacking vehicle after it has been lowered in elevation by compressing into the deformable material layer 109 .
According to a related embodiment as shown for example in FIGS. 12 and 15 , a second visual indicator element 123 is disposed between the sidewalk 120 and the bed 103 . The second visual indicator element 123 is intended to provide a second cue to a vehicle that has already crossed over the first indicator element and is driving on the sidewalk 120 . The second visual indicator element 123 may be similar to the first visual indicator element 121 in that it is distinct in appearance from the sidewalk 120 , the trafficable surface 101 , and the pedestrian cover surface layer 107 (as shown to substantially overlie the deformable material layer 109 ).
According to a further embodiment as shown for example in FIG. 16 , both the first indicator element 121 and the second indicator element 123 are replaced by curbs 102 and 124 respectively, curb 102 shown for example as having an equivalent top elevation with the pedestrian sidewalk, and curb 124 shown for example as having an equivalent top elevation with the top of the pedestrian cover surface 107 of the bed 103 . This “double curb” system serves to provide visual as well as an elevation change (e.g. tactile indication) to alert a driver that the vehicle has left the trafficable surface and is approaching a restricted area, and imparts a vertical velocity component on the vehicle as it enters the bed system 103 .
According to a further embodiment, the pedestrian cover surface layer 107 is intended to spread pedestrian loads over the deformable material layer 109 in the bed system 103 . The pedestrian cover surface layer 107 comprises a sidewalk paving material (e.g. paving elements such as masonry, bricks, stone, cobbles, pavers, etc.—which may be provided in the form of a “loose” unit paving system where the paving elements are laid loose and adjacent to one another over the deformable material) or a planting system (e.g. a material such as soil, sand, grass, sedum, bushes or other planting material, etc.) configured to support pedestrian loads, but configured to give way under vehicle loads and/or the tire motion (spinning, turning, etc.) of a vehicle that drives over the pedestrian cover layer 107 so that the tires of the vehicle breach (e.g. crush, tear, break, etc.) the pedestrian cover layer 107 and come in contact with the layer of deformable or compressible material 109 below. Once the pedestrian cover surface layer 107 is breached, the spinning motion of the vehicle's tires combined with the weight of the vehicle cause it to deform the deformable material layer 109 so that the deformable material layer 109 fails inelastically (i.e. breaks, tears, or is crushed, etc.). According to a preferred embodiment, the deformable material layer 109 comprises a structure (e.g. lattice, honeycomb, etc.) constructed of metal, polycarbonate, plastic, composite metal, wood, etc. and configured to breakaway, collapse, crush, sink or otherwise deform under the weight of the vehicle. The deformable material layer 109 may also comprise a substance (e.g. uniform or composite), alone or in combination with a structure, having characteristics that permit the material to crush, compress, yield, displace, or otherwise deform, such as, for example, cellular concrete, resin, metallic foam, synthetic foam, polymeric foam, (or other material having voids filled with air or the like) or any other suitable material of combination of such materials, having a predefined compression strength, sufficient to crush under a tire(s) of a vehicle weighing at least approximately 2,500 pounds (lbs). The vehicle's weight combined with the rotation (e.g. “spinning” etc.) of the vehicle's tires is intended to deform (e.g. collapse, crush, compress, yield, displace, etc.) the deformable material layer 109 , so that the elevation of the vehicle “drops” or is otherwise “lowered.” The deformation of the deformable material layer 109 of the bed system 103 tends to lower the effective height of the vehicle, as the elevation of the vehicle decreases (e.g. sinks, falls, etc.) into the deformable material 109 , as well as reducing the vehicle's speed, due at least in part to the friction between the tires and the compressible structure of material.
According to any exemplary embodiment of the present invention, the vehicle barrier system is intended to provide an installed barrier for use along a boundary or border such as a security perimeter to protect sites that may be susceptible to a vehicle born intrusion or attack. The vehicle barrier system is designed so that in can be crossed by pedestrians and the like, but prevents passage by vehicles such as automobiles. The vehicle barrier systems employs a variable “composite” approach, using a combination of different attenuation devices and methods in succession to stop a vehicle within a short distance or limited space, such as are typically encountered near buildings and the like. The vehicle barrier system is intended to provide an installed barrier having a “rating” as a crash type barrier consistent with applicable governmental rating criteria. For example, the vehicle barrier system is intended to provide a rating of at least any one of the following K ratings (i.e. a measure of the barrier's potential to stop a vehicle at escalating speed as dictated by standards determined by the U.S. Department of State: K4 (15,000 lb vehicle traveling at 30 miles per hour (mph)), K8 (15,000 lb. vehicle traveling at 40 mph), or K12 (15,000 lb. vehicle traveling at 50 mph.
It is also important to note that the construction and arrangement of the elements of the vehicle barrier system as shown in the preferred and other exemplary embodiments is illustrative only. Although only a few embodiments of the present inventions have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sequence, sizes, dimensions, structures, shapes, profiles and proportions of the various elements, values of parameters, mounting arrangements, use of materials, ballast, orientations, compositions of compressible materials, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements show as multiple parts may be integrally formed. By further way of example, the deformable zone may include a bed having any suitable structure or material configured to support the weight of pedestrians and other generally permissible loads, but is configured to deform sufficiently under the weight of a vehicle or other generally impermissible loads so that the elevation of the vehicle is lowered in relation to the surface grade and to facilitate contact of the vehicle chassis with a second impact element that may have a generally lowered elevation. It should also be noted that the system may be used in association with a wide variety of applications (e.g. corporations, government facilities, entertainment venues, private residences, hospitals, hotels, religious and cultural institutions, etc.) and that the elements of the system may be provided in any suitable size, shape, material and appearance that meets applicable design and performance standards and that creates a desired appearance corresponding to the location of the system. Accordingly, all such modifications are intended to be included within the scope of the present inventions. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present inventions.
The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the inventions as expressed in the appended claims. | A security barrier system for use with a trafficable surface and a site requiring protection from advancing vehicles includes a composite bed system having a plurality of elevations and comprising a first layer beneath a second layer. The first layer includes a deformable material configured to collapse when subjected to vehicle loads, and the second layer includes a pedestrian cover surface over the deformable material that conceals the deformable material. The pedestrian cover surface is configured to support pedestrian traffic over the deformable material without permanently collapsing the deformable material and to collapse along with the first layer when subjected to vehicle loads. A structure beyond the bed system is provided to resist the impact of a vehicle that has traversed the bed system. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is the U.S. national stage of International application PCT/DE2010/000966, filed Aug. 11, 2010 designating the United States and claiming priority to German applications DE 10 2009 038 024.8, filed Aug. 19, 2009 and DE 10 2010 23 113.4, filed Jun. 3, 2010.
BACKGROUND OF THE INVENTION
The invention relates to power station monitoring and regulating concepts taking into account the further development of requirements for the operation of photovoltaic energy generation installations.
The expansion of renewable energies results in new requirements for the availability and operational reliability of energy supply networks as time-dependent fluctuations in energy demand are now accompanied by a fluctuating, hard-to-predict energy supply.
In order to ensure a highly available and stable supply network also for the future, the legislator and the association of energy network operators laid the legal and technical bases for integrating regenerative energy generation installations with more than 100 kWp as controllable power stations into the existing supply networks by adopting the amendment of the Renewable Energies Sources Act (EEG) (October 2008) and the Medium-Voltage Directive of the BDWE (January 2009).
This creates new requirements for the planning, system engineering and operation of photovoltaic power stations. A safe process control system and an intelligent power station management are particularly important for an efficient and cost-effective realisation.
Network operators have not yet been able to define uniform, detailed requirements for network security management, power station regulation, protective functions and the used process control interfaces. At present, this results in very different requirements depending on the voltage level of the network connection point and the responsible network operator. A consultation with the responsible network operator on the requirements for participating in network security management is therefore recommended when applying for network connection.
In general, installations with an installed capacity of more than 100 kW are required to participate in network security management. In this respect, the network operator may limit the active power supplied by the photovoltaic power station to a certain percentage of the power station's installed capacity (currently 100%, 60%, 30%, 0%) by specifying a capacity level. This is accomplished by means of a process control interface defined by the network operator to which the power station regulating system is connected. The network operator may have to be informed of the successful realisation of this specification via the process control system.
So far, capacity reduction has only been described in the art as pure control. This means, a set point command coming from the electric utility is directly sent to all inverters present in the power station, and all are reduced to the same percentage value. Due to losses in the internal power transfer within the power station and possible unavailability of inverters (e.g. units shut down for repair purposes), this causes yield losses beyond the required reduction.
The object of the invention is to provide a system which is free of the disadvantages of the state of the art.
SUMMARY OF THE INVENTION
This object is solved by means of the features of claims 1 , 9 and 12 . Advantageous embodiments of the invention are defined in the dependent claims.
According to a first aspect of the invention, a system for regulating a regenerative energy generation installation comprising a plurality of energy generation units comprises a signal input for receiving a pre-determined set value, a measuring device for measuring an actual value on an output of the energy generation installation, and a regulating device for regulating the actual value to the set value by regulating the individual energy generation units. Instead of simple monitoring, the invention provides a regulating device, which increases reliability and efficiency.
Regulated variables of the regulating device may be active power, reactive power, displacement factor, power factor, mains frequency and/or mains voltage.
The regulating device can additionally process measured values of the energy generation units.
The system for dynamic regulation may comprise one or several interface units for different types of energy generation units.
Passive elements of the energy generation installation can be taken into account by the regulating device.
The system for dynamic regulation may comprise a signal output for information feedback to a superordinate system, such as a network control centre or a control computer of a power station. Thus, the regulating device can also be extended to the superordinate level.
The set value can be received by a superordinate system, such as a network control centre or a control computer of a power station.
The regulating device can have a PID controller which can be realised in an easy and sturdy manner. Other classical controllers and further controllers such as neural networks can be used.
According to another aspect of the invention, a regenerative energy generation installation comprising a plurality of energy generation units comprises a system for dynamic regulation of the energy generation installation as described above. The connection of the regenerative energy generation installation and the system for dynamic regulation of the energy generation installation has the advantage that no or only few measures are required regarding logs and/or interfaces.
The energy generation unit can, e.g., be an inverter, rectifier or DC/AC converter.
The regenerative energy generation installation may comprise a photovoltaic energy generation installation. At times, photovoltaic energy generation installations can exhibit a strongly fluctuating output power, such that they are predestined for the invention.
According to another aspect of the invention, a method for regulating a regenerative energy generation installation comprising a plurality of energy generation units comprises the steps:
receiving a set value, measuring an actual value on an output of the energy generation installation, and regulating the individual energy generation units for regulating the actual value to the set value.
The set value can be received by a superordinate system, such as a network control centre or a control computer of a power station.
Information can be sent to a superordinate system, such as a network control centre or a control computer of a power station. Thus, the regulating device can be extended to the superordinate level.
Further measured values from the energy generation installation and/or external measured values can be processed for rendering the control even more intelligent, i.e. rendering it even more adjustable to the given situation.
The invention extends the range of photovoltaic system technology from comprehensive, manufacturer-independent monitoring of large photovoltaic power stations to complete control room functionality with intelligent concepts of power station regulation.
The concepts support and improve the power stations with monitoring. The main purpose is capacity reduction upon request by the electric utility. A regulation by measuring the actual output power of the power station and comparison to the specification and a corresponding readjustment of inverter control in a closed-loop regulation chain can help avoid said yield losses.
This concept of closed-loop regulation can be additionally improved by using the data obtained through monitoring. To this end, the current availability and load of all installation components are included in regulation calculation and thus, the capacity to be reduced is spread over individual inverters. On the one hand, this helps to regulate the power station in any state very quickly and efficiently. On the other hand, it is also possible to integrate inverters of different installed capacity and even of various manufacturers into the power management of one power station and distribute the load (or reduced load due to reduction) dynamically.
This concept can also be applied to the regulation of electrical parameters at the network connection point (such as displacement factor cos-phi, mains frequency or mains voltage). In particular, the compensation of reactive power would be advantageous for active power yield and load distribution in the power station thanks to a differentiated regulation designed for every inverter.
Possible additional requirements of individual photovoltaic power stations which can be operated by the regulating device of the invention may include the following points, but are not limited to this list:
stabilisation of the displacement factor (cos φ) to a fixed, pre-determined value at the network connection point; stabilisation of the displacement factor (cos φ) to a variable value pre-determined by the network operator via a process control interface at the network connection point; readjustment of the displacement factor (cos φ) depending on the active power fed in or the existing mains voltage according to a pre-determined curve at a pre-determined speed; provision of short-circuit current (fault ride through); active power reduction up to over- or underfrequency tripping according to a pre-determined diagram; disconnection of the generation installation in case of under- or overvoltage according to a pre-determined voltage-time diagram; transmission of the actual values to the network operator via a pre-determined process control interface.
The invention covers the following points:
hard- and software for the process control system with interfaces to:
transducers in the power station and at the network connection point radio ripple receivers and process control interfaces of the network operator inverters of various manufacturers;
active power limitation according to specifications by the network operator to a pre-determined limitation level within a pre-determined time (standard: one minute); slow, controlled start-up of derated power stations after lifting of the active power limitation by the network operator; reactive power regulation at the network connection point to a pre-determined static or variable displacement factor (cos φ); reactive power regulation at the network connection point to a pre-determined displacement factor (cos φ) independent of active power or mains voltage; reactive power compensation of passive reactance in the energy distribution of the power station (e.g. long underground cable routes to a transmission substation) from a minimum active power fed in. mains frequency-based active power reduction in case of deviations in mains frequency for network stability; monitoring of all switching operations of the power station's protective functions (over- or undervoltage tripping); partial realisation of the power station's protective functions, such as tripping of continued short circuits (unless this is ensured by each individual inverter on the low-voltage side); actual and set value feedback of the power station regulating system to the network operator via multiple communication and process control interfaces; feedback of a real-time yield prediction of the currently possible active power supply to the network operator (for determining the yield losses in case of active power limitation); integration of all measured and regulating values and all parameters of the power station regulating system into the continuous power station monitoring for:
status feedback of the power station regulating system functional and error check of the power station regulating system automatic error message in case of deviations from set standards of the power station regulating system archiving of all specification events of the network operator and the corresponding control and regulation operations in monitoring for subsequent verification of reaction times and yield losses.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, drawings are used to describe the invention in greater detail, in which is shown:
FIG. 1 a block diagram of a system for monitoring a regenerative energy generation installation.
FIG. 2 a block diagram of a power station regulating system.
The drawings merely serve the purpose of illustrating the invention and are not intended as a limitation. The drawings and the individual parts are not necessarily to scale. The same reference signs refer to same and similar parts.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 schematically shows a block diagram of the system for dynamic monitoring of a regenerative energy generation installation. As an example, the energy generation installation may be a solar, wind or hydroelectric power station. The energy generation installation comprises a plurality of energy generation units in the form of inverters. Such inverters are regulated for adjusting the capacity (P, Q) and/or electrical parameters (displacement factor, power factor, mains frequency and/or mains voltage) on the output or network feed-in point of the energy generation installation to certain specifications. In a first step, the system monitors the regenerative energy generation installation and, in a second step, the system regulates the installation.
The specifications may, for instance, be transmitted as individual values or common vector by a superordinate system such as a network control centre to the energy generation installation or originate from a control computer of the energy generation installation. The specifications or set values can be dynamic or static. For the reactive power Q, e.g. a fixed value or dependence on the active power supplied or on the mains voltage can be specified. A specification of a fixed value or a specification of a certain reduction or increase within a certain time can be realised by the regulating device.
The specification or the set value is provided to the regulating device, e.g. a PID controller. Just like an actual value which is measured on the output or network connection point of the energy generation system by a transducer or measuring converter. The controller controls several inverters which may also be of different design. For this purpose, one or several interface units can be provided for operating the various logs or signal levels of the inverters. The interface unit can be integrated into the controller or be a stand-alone unit.
The regulating system can receive measured values of the inverters in order to, e.g., integrate their availability, load, operating point into regulation for minimising losses. Furthermore, the controller can take into account passive power elements such as transformers, lines, etc. and the topology such as different line lengths or qualities for regulation in order to minimise losses.
This system regulates the distributed system of energy generation units in order to prevent or minimise losses due to reduced feed-in or non-optimum use of the resources of the energy generation installation.
FIG. 2 shows a schematic representation of the power station regulating system, i.e. the environment into which the system of FIG. 1 is embedded. As an example, a control centre of the network operator comprising a control system communicates with the power station regulating system in order to specify values and obtain information and measured values on the state of the power station. To this end, the power station regulating system has a control system interface. The communication between the control system interface and the control system of the network operator occurs via wired or wireless communication channels known in the art.
The control system interface is directly or indirectly connected to the controller functions of the power station regulating system. The controller functions correspond to the inner part of the regulation loop of FIG. 1 , i.e. to the controller and the consideration of the passive power elements according to FIG. 1 . The controller functions have one or several bidirectional interfaces to the inverters as already discussed in FIG. 1 .
In addition, the controller functions have one or several bidirectional interfaces to the power station monitoring in order to obtain and take into account information on the state of the overall power station for regulation. Moreover, the controller functions can output values and/or results from the regulating device to the power station monitoring such that the latter can process them.
The controller functions have one or several bidirectional interfaces to special measuring systems in order to be able to include further information into the regulating device. The special measuring systems can e.g. comprise transducers monitoring the network feed-in point. The special measuring systems can provide further measured values from the power station and external data, such as real-time insolation data, temperature influences, wind measurement data and weather forecasts for intelligent regulation. Moreover, the special measuring systems can provide all measured values, conditions or specifications important or desirable for regulation to the controller functions.
As additional input data for the regulating device or the controller functions, energy forecast values for both the primary energy supply (sun, heat, wind) and the load demand in the energy network (load profiles) are used. Such input data can be obtained via data interfaces from the electric utility, power station operator or an external service provider and used for regulating the installation.
Furthermore, energy storage concepts are integrated into the power station regulating system. To this end, data interfaces are intended to energy storage systems such as flywheel mass storage systems, battery systems, compressed-air storage systems, pumped-storage systems, etc. Moreover, the system analyses requirements of the electric utility or operator in order to provide energy quantities on a short- and medium-term basis via input interfaces. The data and input interfaces can be analogous or digital. A feedback on the amount of energy available in the storage systems and an intelligent estimate as to the energy reserves to be expected in the forecast period is intended to be provided to the electric utility, power station operator or other superordinate control system.
The system also regulates and monitors cogenerative systems. These are combined systems of generation units with different primary energy sources. Thus, a complete installation, comprising, e.g., photovoltaic inverters, wind turbines, a battery storage system and emergency power system running on diesel, can be regulated and monitored by a central controller to and for external requirements regarding active and reactive power, frequency and mains voltage behaviour, etc. | The invention relates to a system for the dynamic regulation of a regenerative energy generation installation comprising a plurality of energy generation units. The system has a signal input for receiving a pre-determined set value, a measuring device for measuring an actual value on an output of the energy generation installation, and a regulating device for regulating the energy generation units based on the set value and the measured actual value. | 7 |
RELATED APPLICATIONS
This application contains subject matter related to U.S. application Ser. No. 09/826,423 of Maslov et al., filed Apr. 5, 2001, now U.S. Pat. No. 6,492,756; U.S. application Ser. No. 09/826,422 of Maslov et al., filed Apr. 5, 2001, U.S. application Ser. No. 09/966,102, of Maslov et al., filed Oct. 1, 2001, U.S. application Ser. No. 09/993,596 of Pyntikov et al., filed Nov. 27, 2001, U.S. application Ser. No. 10/173,610 of Maslov et al., filed Jun. 19, 2002, now U.S. Pat. No. 6,727,668; U.S. application Ser. No. 10/353,067 of Maslov et al., filed Jan. 29, 2003, and U.S. application Ser. No. 10/386,599 of Maslov et al., filed Mar. 13, 2003, all commonly assigned with the present application. The disclosures of these applications are incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to electric vehicles, and more particularly to adaptive cruise control system utilizing phase advance angle adjustment and selection of control current waveform profiles for adaptively controlling the electric motor of a vehicle.
BACKGROUND
A cruise control system in a vehicle provides automatic speed control to enable the vehicle to maintain constant speed under variable driving conditions without driver's intervention. A conventional cruise control system in an electric vehicle controls an electric motor of the vehicle to request a torque value required to achieve a desired speed.
Under typical driving conditions, torque values required to achieve a desired speed are subject to wide variability with little, if any, long term predictability. Moreover, driving conditions, such as steep uphill grade or heavy vehicle load or the like, may impose limitations on available speed and acceleration.
Higher acceleration or greater speed may be required than the system can accommodate at maximum torque restricted by available motor power supply. In particular, the voltage signal that the motor control needs to produce in order to request the torque required to achieve the desired speed may be greater that the supply voltage. Therefore, the motor would not be able to develop the required torque.
In addition, in a vehicle drive environment, wherein power availability is limited to an on-board supply, it is highly desirable to attain a high torque output capability at minimum power consumption. Motor structural arrangements described in the copending applications contribute to these objectives. As described in those applications, electromagnet core segments may be configured as isolated magnetically permeable structures in an annular ring to provide increased flux concentration. Isolation of the electromagnet core segments permits individual concentration of flux in the magnetic cores, with a minimum of flux loss or deleterious transformer interference effects occurring from interaction with other electromagnet members.
The above-identified co-pending application Ser. No. 10/173,610 describes a control system for a multiphase motor that compensates for variations in individual phase circuit elements. A high degree of precision controllability is obtained with each phase control loop closely matched with its corresponding winding and structure. Successive switched energization of each phase winding is governed by a controller that generates signals in accordance with parameters associated with the respective stator phase components. The phase windings are energized with current of sinusoidal waveform for high efficiency operation. The control system varies the output current to respond to, and accurately track, the torque command input.
The sinusoidal current waveform profile obtained with this commutation strategy can extend battery life through efficient operation. However, in vehicle driving operation there may be a need for torque capability in excess of that available from the most efficient control scheme. Typically, the power supply is rated for a maximum current discharge rate, for example, 10.0 amps. If the cruise control system requests a torque command that correlates to this maximum current draw, then the motor torque output for a sinusoidal current waveform profile is limited, for example, to approximately 54.0 Nm in a motor with a configuration such as described above.
The above-identified copending application Ser. No. 10/386,599 describes a cruise control system including a control circuit for producing a control signal to control an electric motor of the vehicle. The control signal is formed based on a control current required to achieve the desired speed. The system determines a motor control scheme that provides an appropriate waveform profile of the control current for available driving conditions. In particular, the system performs switching between a high-efficiency motor control scheme that provides a substantially sinusoidal waveform profile of the control current for achieving operating efficiency of the motor, and a high-torque motor control scheme that provides a substantially rectangular waveform profile of the control current for achieving high torque. The replacement of the high-efficiency control scheme with the high-torque control scheme results in a higher torque needed when torque obtainable with the high-efficiency control scheme is not sufficient for the cruise control system to maintain a desired speed. However, the motor operating at the high-torque control scheme sacrifices some of the efficiency achievable with the sinusoidal waveform profile.
Accordingly, it would be desirable to maintain operations with a substantially sinusoidal waveform profile as long as the required torque is achievable using a high-efficiency control scheme.
Hence, the need exists for precision adaptive motor control that would extend a range of motor operation at a high-efficiency motor control scheme in a cruise control system having various motor control schemes.
DISCLOSURE OF THE INVENTION
The present invention fulfills this need by providing a novel cruise control system for adaptively controlling an electric vehicle to maintain desired speed under variable driving conditions. This system comprises a control signal generating circuit that produces a control signal to energize an electric motor of the vehicle based on control current required to achieve the desired speed. A phase advance angle adjustment circuit is provided for adaptively controlling a phase advance angle between the control current and back-EMF in response to changes in driving conditions to produce the control current sufficient to achieve the desired speed.
In accordance with one aspect of the invention, the cruise control system utilizes multiple motor control schemes for controlling the motor using various waveform profiles of the control current. A motor control scheme selection circuit enables the cruise control system to select a current waveform profile appropriate for present driving conditions. The motor control scheme may adaptively modify a present current waveform profile, if the control current with the adjusted phase advance angle is not sufficient to achieve the desired speed.
For example, the cruise control system may utilize a high-efficiency motor control scheme with a substantially sinusoidal current waveform profile to provide efficient motor operation, and a high-torque motor control scheme with a substantially rectangular waveform profile to provide higher torque required to maintain a desired speed. The phase advance angle adjustment circuit enables the cruise control circuit to maintain the high-efficiency motor control scheme as long as the phase advance angle can be adjusted to provide torque sufficient to maintain a desired speed.
If the cruise control system determines that a change in driving conditions makes it impossible to maintain a desired speed at the high-efficiency motor control scheme even with the adjusted phase advance angle, the motor control scheme selection circuit selects a high-torque motor control scheme to modify a substantially sinusoidal current waveform profile into a substantially rectangular current waveform profile in order to increase torque.
Hence, phase advance angle adjustment enables the cruise control system to provide precision adaptive motor control for maintaining efficient motor operation as long as driving conditions allow the system to maintain a desired speed at a high-efficiency motor control scheme.
In accordance with an embodiment of the present invention, the motor may be a multiphase permanent magnet motor having a stator with a plurality of phase windings. The control signal is provided to energize each phase winding of the motor. The phase advance angle adjustment circuit may set the phase advance angle for each phase of the motor.
In accordance with another aspect of the invention, the phase advance angle may be optimized to maximize torque value and minimize motor phase current for the actual speed of the vehicle and torque required to achieve the desired speed.
The phase advance angle adjustment circuit may comprise a look-up table responsive to actual speed of the vehicle and torque required to achieve the desired speed, for outputting the control current with the adjusted phase angle. The look-up table may be configured to output the control current with the modified waveform profile, if the current with the adjusted phase advance angle is not sufficient to achieve the desired speed.
In accordance with a method of the present invention, the following steps are carried out to adaptively control an electric vehicle to maintain desired speed under variable driving conditions:
producing a control signal to energize an electric motor of the vehicle, based on control current required to achieve the desired speed, and adaptively controlling a phase advance angle between the control current and back-EMF to produce the control current sufficient to achieve the desired speed.
The method may further involve the step of adaptively modifying waveform profile of the control current if the control current with the adjusted phase advance angle is not sufficient to achieve the desired speed.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the invention is 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. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawing and in which like reference numerals refer to similar elements and in which:
FIG. 1 is an exemplary view showing rotor and stator elements in a configuration that may be employed in the present invention.
FIG. 2 is a block diagram of an adaptive cruise control system in accordance with the present invention.
FIG. 3 is a flow chart illustrating operations of the adaptive cruise control system in accordance with the present invention.
FIG. 4 is a curve representing motor control scheme selection for ranges of torque and speed in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is applicable to a vehicle driven by an electric motor such as disclosed in the copending application Ser. No. 09/826,422, although the invention can be used with various other permanent magnet motors. FIG. 1 thus is an exemplary view showing rotor and stator elements of a motor 10 as described in that application, the disclosure of which has been incorporated herein. Rotor member 20 is an annular ring structure having permanent magnets 21 substantially evenly distributed along cylindrical back plate 25 .
The permanent magnets are rotor poles that alternate in magnetic polarity along the inner periphery of the annular ring. The rotor surrounds a stator member 30 , the rotor and stator members being separated by an annular radial air gap. Stator 30 comprises a plurality of electromagnet core segments of uniform construction that are evenly distributed along the air gap. Each core segment comprises a generally U-shaped magnetic structure 36 that forms two poles having surfaces 32 facing the air gap. The legs of the pole pairs are wound with windings 38 , although the core segment may be constructed to accommodate a single winding formed on a portion linking the pole pair.
Each stator electromagnet core structure is separate, and magnetically isolated, from adjacent stator core elements. The stator elements 36 are secured to a non-magnetically permeable support structure, thereby forming an annular ring configuration. This configuration eliminates emanation of stray transformer flux effects from adjacent stator pole groups. The stator electromagnets are thus autonomous units comprising respective stator phases.
The concepts of the invention, more fully described below, are also applicable to other permanent magnet motor structures, including a unitary stator core that supports all of the phase windings.
FIG. 2 is a block diagram of an adaptive cruise control system in accordance with the present invention. A plurality of stator phase windings 38 of the multiphase motor 10 (shown in FIG. 1 ) are switchably energized by driving current supplied from d-c power source 40 via power block 42 . The power block 42 may comprise electronic switch sets that are coupled to controller 44 via a pulse width modulation converter and gate drivers. Each phase winding is connected to a switching bridge having control terminals connected to receive pulse modulated output voltages from the controller. Alternatively, the switching bridges and gate driver components may be replaced by amplifiers linked to the controller output voltages. Rotor position and speed sensor 46 provides rotor position and speed feedback signals to the controller 44 . The sensor 46 may comprise a well-known resolver, encoder or their equivalents and a speed approximator that converts the position signals to speed signals in a well-known manner.
The controller 44 may comprise a microprocessor or equivalent microcontroller, such as Texas Instrument digital signal processor TMS320LF2407APG. Coupled to the controller may be RAM and ROM memories for storing programs and data used in the controller's operation.
Phase advance and profile memory 48 is shown separately in the drawing for purposes of illustration of the inventive concepts. The phase advance and profile memory 48 may comprise a look-up table for storing phase advance and motor control scheme data that determine phase advance angle and motor current waveform profiles selectable in accordance with driving conditions.
The phase advance angle and motor control schemes stored in the profile memory 48 are selected based on a torque command τ d , actual speed ω of the vehicle and rotor position θ that may be determined by the position/speed sensor 46 . The torque command τ d determines torque required to achieve the desired speed ω d maintained by the cruise control system.
In a well known manner, the desired speed is defined by set/resume switch 50 that sets the desired speed in the cruse control system, or commands the system to resume the desired speed set previously. The desired speed value is supplied to latch 52 that monitors cruise control switch 54 to determine whether a cruise control mode is set, and monitors brake pedal 54 to determine whether the cruise control mode is released. Subtracting unit 58 determines the difference Δω between the actual speed and the desired speed. Based on this difference, acceleration/deceleration characteristics unit 60 determines the torque command τ d required to achieve the desired speed. The acceleration/deceleration characteristics unit 60 calculates torque using a well-known algorithm for determining torque for particular acceleration and deceleration characteristics.
In order to develop the desired phase currents, the controller 44 of the cruise control system generates the following control voltage:
V i ( t )= L i dI di /dt+R i I i +E i +k si e i
where
V i (t) is the voltage across the phase winding; I di (t) is the desired phase current to be produced to obtain torque required to achieve the desired speed ω d ; I i (t) is the phase current; R i is the winding resistance; E i (t) is the back-EMF; L i is the winding self-inductance; k si is the current loop feedback gain; and e i is the phase current error.
The methodology by which the controller 44 derives the components of this voltage control expression is described in more detail in copending application Ser. No. 10/386,599 entitled “ELECTRIC VEHICLE WITH ADAPTIVE CRUISE CONTROL SYSTEM” and in copending application Ser. No. 10/353,067 entitled “PHASE ADVANCE ANGLE OPTIMIZATION FOR BRUSHLESS MOTOR CONTROL” both incorporated herein by reference. The desired phase current I di required to obtain torque needed to achieve the desired speed is provided by the phase advance and profile memory 48 in accordance with a phase advance angle and a motor control scheme selected by the cruise control system.
The desired phase current I di (t) defines a control scheme which determines a manner in which the cruise control system responds to the torque command requested by the system to achieve the desired speed. Each control scheme effects a particular motor current waveform profile having unique characteristics with respect to efficiency, torque capacity, response capability, power losses, etc., in comparison to other control schemes. In particular, substantially sinusoidal waveform profile of the desired phase current I di (t) defines a high-efficiency control scheme that enables the motor to achieve high operating efficiency.
A significant aspect of the present invention is provision of phase advance angle optimization in a cruise control system having a plurality of available motor control schemes adaptively selected to obtain a desired response. For example, the introduction of the phase advance angle adjustment enables the motor to achieve higher torque at a high-efficiency control scheme using substantially sinusoidal waveform profile of desired phase current I di . As a result, a range of motor operation at the high-efficiency control scheme may be extended.
FIG. 3 is a flow chart illustrating operation of the adaptive cruise control system of the present invention. After an appropriate delay to wait until a cruise control loop begins (step 82 ), the cruise control system checks whether or not the switch for engaging cruise control operation is in ON state (step 84 ). If so, the cruise control system checks whether the brake pedal 56 was pressed after engaging the cruise control operation (step 86 ). If so, the cruise control operation is terminated. However, if the brake pedal was not pressed, the system determines the desired speed ω d to be maintained (step 88 ). The desired speed is defined in a well know manner by set/resume switch 50 that sets the desired speed in the cruse control system, or commands the system to resume the desired speed set previously.
The actual speed ω measured in a well-known manner (step 90 ) is compared with the desired speed ω d to calculate the speed error Δω as the difference between the actual speed and the desired speed (step 92 ). The torque command τ d that defines torque required to achieve the desired speed ω d is determined based on the speed error and a desired acceleration/deceleration characteristics (step 94 ). For example, the torque command may be determined for linear or S-curve acceleration/deceleration characteristics based on well-known algorithms.
In step 96 , the torque command, actual speed and rotor position are input to a pre-computed 2-D look-up table containing phase advance and motor control scheme data in the phase advance and profile memory 48 . The look-up table stores motor control scheme data for supporting various modes of operation manifesting different operational aspects. For example, the cruise control system may operate using a high-efficiency motor control scheme utilized to energize the phase windings with current of sinusoidal waveform trajectory I sin (t) for high efficiency operation. The sinusoidal current waveform profile obtained with this motor control scheme can extend battery life.
Other control schemes may be utilized to manifest particular operational aspects of the cruise control system. For example, for higher torque operation, a high-torque motor control scheme may be utilized to obtain a square wave current waveform trajectory I sq (t) of the desired phase current I di (t) supplied to the controller 44 .
The replacement of the high-efficiency control scheme with the high-torque control scheme results in a higher torque needed when torque obtainable with the high-efficiency control scheme is not sufficient for the cruise control system to maintain a desired speed. However, the motor operating at the high-torque control scheme sacrifices some of the efficiency achievable with the sinusoidal waveform profile.
Accordingly, it would be desirable to maintain operations with a substantially sinusoidal waveform profile of the phase current I di as long as the required torque is achievable using the high-efficiency control scheme. The cruise control system of the present invention utilizes the phase advance technique to achieve an extended range of operation with current of sinusoidal waveform trajectory I sin (t) for achieving higher efficiency. The extended range is provided by controlling the phase advance angle α between the current vector and the back-EMF vector.
For achieving a higher torque using the phase advance technique, the per-phase desired current trajectories are selected according to the following expression:
I di ( t )= I opti sin( N r θ i +α opti ),
where I di denotes per-phase desired current trajectory, I opti is per-phase optimal current amplitude, N r is the number of permanent magnet pole pairs, θ i represents relative positional displacement between the i th phase winding and a rotor reference point, and α opti is per-phase optimal phase advance angle.
An optimization scheme such as described in the copending application Ser. No. 10/353,067 entitled “PHASE ADVANCE ANGLE OPTIMIZATION FOR BRUSHLESS MOTOR CONTROL” may be used to determine per-phase optimal phase advance angle α opti and per-phase optimal phase current amplitude I opti utilized to determine per-phase current I di (t) required to enable the motor to develop a torque needed to maintain a desired speed. The per-phase optimal phase advance angle α opti and per-phase optimal phase current amplitude I opti are set to obtain a maximum torque value for actual speed of the vehicle, and to minimize motor phase current for the actual speed of the vehicle and torque required to achieve the desired speed.
The 2-D look-up table in the phase advance and profile memory 48 responsive to the motor speed and user requested torque command inputs provides the optimal values of phase current amplitude and phase advance angle for various combinations of torque command τ d and actual speed ω. Since the optimal values of phase current amplitude and phase advance angle are determined based on phase dependent parameters such as reactance of phase windings, torque coefficient and back-EMF, the optimization processes are performed for each phase to determine control signals V i (t) for respective phase windings. As a result, the phase advance angle optimization process of the present invention accounts for the parameter variations in the separate phase windings and stator phase component structures.
Further, the look-up table in the phase advance and profile memory 48 stores motor control scheme data formulated to enable selection between different motor control schemes for various combinations of torque command τ d and actual speed ω. While the motor control scheme selection can be performed by repeated calculation of a torque capacity threshold on a real time basis, calculations of voltage for various combinations of torque request and motor speed can be made in advance and linked with the appropriate motor control scheme in the lookup table.
For example, FIG. 4 shows a curve that represents a boundary in such a lookup table between ranges for high-efficiency motor control scheme selection and high-torque motor control scheme selection. With the abscissa of the graph in FIG. 4 representing actual speed and the ordinate representing requested torque, the curve is asymptotic to both axes with speed/torque combinations above the curve being beyond the capacity of the system to obtain torque in the high efficiency profile operational mode.
For each combination of torque command τ d and actual speed ω corresponding to the high-efficiency motor control scheme with current of sinusoidal waveform trajectory, the look-up table in the phase advance and profile memory 48 stores per-phase optimal phase advance angle α opti and per-phase optimal phase current amplitude I opti determined to maximize torque value for actual speed of the vehicle, and to minimize motor phase current for the actual speed of the vehicle and torque required to achieve the desired speed.
Hence, the controller 44 at step 96 interacts with the look-up table in the phase advance and profile memory 48 to determine a control strategy appropriate for current driving conditions. For example, the controller 44 may determine whether phase advance angle α opti stored in the look-up table for a particular combination of torque command τ d and actual speed ω is valid, i.e. whether the phase advance angle is not less than zero (step 98 ). If the controller 44 determines that for the current combination of torque command τ d and actual speed ω, the look-up table stores a valid phase advance angle α opti , a high-efficiency motor control scheme with the respective phase advance angle α opti is selected (step 100 ).
The selection of high-efficiency motor control scheme results in energizing the phase windings with current of sinusoidal waveform for high efficiency operation.
The sinusoidal wave current trajectory I sin (t) of the desired phase current I di (t) supplied to the controller 44 is generated from the following equation:
I sin ( t )= I opti sin( N r θ i +α opti ).
Application of the phase advance angle optimized to maximize torque needed to achieve a desired speed enables the cruise control system of the present invention to extend a range of operation at the high-efficiency control scheme beyond limits available without phase advance angle adjustment. As a result, the cruise control system of the present invention provides precision control of the motor to minimize power consumption while achieving torque required to maintain the desired speed.
If no valid phase advance angle is found in the look-up table for the current combination of torque command τ d and actual speed ω, the controller 44 selects a high-torque motor control scheme to obtain a square wave current waveform trajectory I sq (t) of the desired phase current I di (t) supplied to the controller 44 (step 102 ). The square wave current waveform trajectory I sq (t) may be obtained using the following expression:
I sq =I rn sgn (sin( N r θ i ))
where sgn (x) denotes the standard signum function and is defined as 1 if x>0, 0 if x=0, and −1 if x<0. The square wave current waveform I sq (t) may have a trapezoidal shape with configurable rising and falling edges.
Based on selected motor control scheme with respective waveform profile of the desired phase current I di (t), the controller 44 of the cruise control system generates the following control voltage:
V i ( t )= L i dI di /dt+R i I i +E i +k si e i
utilizing the torque command value and the signals received from phase current sensors, position sensor and speed detector (step 104 ). The computations of V i (t) may be performed successively for each phase in real time.
The look-up table in the phase advance and profile memory 48 may store the term L i dI di /dt, as well as the back-EMF value E i used in the calculation of the voltage V i (t). The value E i may be selected from the lookup table based on a combination of speed and rotor position.
Then, the controller 44 successively outputs calculated control signals V i (t) for each phase to the power block 42 for individual energization of respective phase windings in a sequence established in the controller 44 (step 106 ). Each successive control signal V i (t) is related to the particular current sensed in the corresponding phase winding, the immediately sensed rotor position and speed, and also to model parameters, K ei and K τi , that have been predetermined specifically for the respective phases.
In this disclosure there is shown and described only preferred embodiments of the invention and a few examples of its versatility. It is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein. As can be appreciated, the cruise control system with precision motor control of the present invention can be utilized in a wide range of applications in addition to vehicles.
Further, various other motor control schemes defining different current waveform profiles may be utilized. The profile memory thus may store a plurality of motor control scheme data sets accessible by the controller in response to receipt of specific motor control scheme selection commands. Various lookup tables of varying complexities can be formulated for appropriate profile mode selection by the controller. | A novel cruise control system is provided for adaptively controlling an electric vehicle to maintain desired speed under variable driving conditions. This system utilizes multiple motor control scheme for controlling the motor using various waveform profiles of the control current, and involves phase advance angle adjustment provided for adaptively controlling a phase advance angle between the control current and back-EMF in response to changes in driving conditions to produce the control current sufficient to achieve the desired speed. A motor control scheme selection circuit enables the cruise control system to select a current waveform profile appropriate for present driving conditions. A selected current waveform profile is modified, if the control current with the adjusted phase advance angle is not sufficient to achieve the desired speed. | 8 |
FIELD OF THE INVENTION
This invention relates to countercurrent extraction, and more particularly to an elution system combining countercurrent distribution and countercurrent chromatography.
BACKGROUND OF THE INVENTION
Various separation methods have been applied to macromolecules and cell particles. Among the various processes, partition with aqueous/aqueous polymer phase systems has several desirable features; and consequently this method provides great advantage over other separation methods. Various types of new polymer phase systems have been introduced for separation of a variety of biological samples. However, high viscosity, low interfacial tension, and relatively low density difference between the two solvent phases have produced various technical problems in performing partition with the polymer phase systems. In general, these partition methods may be divided into two categories: one is the countercurrent distribution method (CCD) and the other is the countercurrent chromatography method (CCC).
CCD uses a discontinuous partition procedure consisting of the following three steps: mixing of the two solvent phases by shaking, settling them into two layers, and transfer of the mobile phase (usually the upper phase) of each partition unit to the next partition unit. Because of high viscosity and low interfacial tension between the two phases, the use of the conventional Craig apparatus becomes impractical due to the long settling times required. A substantial improvement in separation times has been achieved by introduction of a thin-layer countercurrent distribution apparatus which provides an extremely short settling distance of a few millimeters for each phase, thus reducing the settling time down to a few minutes. More recently, a fully automated centrifugal thin-layer CCD apparatus which permits both phase separation and transfer processes in a strong centrifugal force field has been designed. However, that method still requires a considerably long separation time of one theoretical plate or one operational cycle every two minutes.
CCC has also been used for partition of various biological samples under continuous elution of the mobile phase. The method generally uses a coiled column under a centrifugal force field. High speed CCC recently developed can yield an extremely high partition efficiency of one theoretical plate per second with conventional organic/aqueous two-phase solvent systems. However, when the method is applied to partition with aqueous/aqueous polymer phase systems, high viscosity of the polymer phases causes insufficient mixing of the two solvent phases in the coiled column resulting in poor peak resolution. Consequently, the method fails to produce significant improvement over the CCD method previously described. The best results have been obtained with a special type of the coil planet centrifuge called the nonsynchronous flow-through coil planet centrifuge which generates slow rotation of a coiled column under a strong centrifugal force field. However, this apparatus is extremely complex and expensive and in addition the applicable flow rate of the mobile phase is limited due to carry over of the stationary phase.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to obviate problems of the prior art, such as discussed above.
It is another object of the present invention to provide for improved countercurrent extraction; and yet another object to provide a novel method and apparatus for countercurrent extraction.
It is a further object of the present invention to combine the advantages of the countercurrent distribution method (CCD) with the advantages of countercurrent chromatography (CCC).
The present invention introduces a separation column construction which enables efficient partitioning with aqueous/aqueous polymer phase systems and therefore permits universal application for separation and purification of various biological samples such as proteins, nucleic acids, polysaccharides, cell organelles, etc.
When a straight elastic rod (tubular or solid), one end of which is supported by a stopper, is inserted into the separation column, high frequency vibration will cause the free end of the rod to vibrate back and forth inside the column unit. This procedure efficient mixing of the two solvent phases, while in the phase at the opposite end of the rod (close to the stopper) the effect of the vibration is negligible leaving that phase relatively undisturbed. The rod should extend at least far enough into the receptacle to produce efficient mixing of the phase furthest from the stopper. Generally, the rod should extend for at least a majority of the length of the receptacle. Preferably, the rod should extend almost to the distal end of its receptacle.
In one embodiment of the invention, the above hydrodynamic effect can be effectively utilized for performing continuous partitioning by replacing the rod with a flow tube for elution of the mobile phase. Multiple units can be connected in series with flow tubes in such a way that the outlet of each receptacle tube extends toward the other end of each next tube. The mobile phase at the vicinity of the stopper, where the mixing effects is minimized, becomes almost free of the stationary lower phase and is then transferred to the next column unit to repeat the process. Finally, all the column units reach hydrostatic equilibrium and thereafter the mobile phase is collected from the outlet of the column. Similar hydrodynamic process can be observed with the lower phase eluting through an inverted column.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1D show cross-sectional views of chromatography columns before and after the introduction of a mixing rod.
FIGS. 2A and 2B show cross-sectional views of three column units connected in series with flexible flow tubes acting as the mixing rods according to the present invention.
FIG. 3 is a diagram of the motion developed in various synchronous coil planet centrifuges.
FIG. 4 is a diagram of the typical centrifugal force field generated by Type J synchronous planetary motion.
FIG. 5 is a diagram of the design principle of a Type J centrifuge.
FIG. 6 shows a cross-sectional view of the Type J coil planet centrifuge which can be employed to provide a strong oscillating centrifugal force field according to the present invention.
FIGS. 7A-7C show cross-sectional views of possible column designs according to the present invention.
FIG. 8 shows a cross-sectional view of a block with cavities in it according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A-1C illustrate the general principle of the present invention. In FIG. 1A a column unit contains nearly equal volumes of two solvent phases which are separated by a stable force field as indicated by an arrow at the bottom. Application of an oscillating force field at a high frequency fails to mix the two solvent layers because of their high viscosity as indicated in FIG. 1B. However, when a straight elastic rod 12, one end of which is supported by a stopper 14, is inserted, the high frequency vibration causes the free end of the rod 12 to vibrate back and forth inside the column unit producing efficient mixing of the two solvent phases (FIGS. 1C and 1D), while at the opposite end of the rod the effect of vibration becomes negligible leaving the upper (FIG. 1C) or the lower (FIG. 1D) phae undisturbed as illustrated.
The above hydrodynamic effect can be effectively utilized for performing continuous partitioning by replacing the rod 12 with a flow tube 16 for elution of the mobile phase as shown in FIGS. 2A and 2B where three column units are connected in series with flow tubes 16 in such a way that the outlet of each tube extends toward the other end of column unit as illustrated in FIGS. 2A and 2B. In FIG. 2A the column is first completely filled with the lower stationary phase (dark) and the upper mobile phase is eluted with a pump while applying an oscillating force field to induce vibration of the free end of the flow tube. As the mobile phase enters the first column unit through the vibrating flow tube 16, it is immediately dispersed and mixed with the stationary phase to establish a hydrostatic equilibrium of the two solvent phases where the mixing effects of the vibrating flow tube and the settling effects of the force field are balanced to form a density gradient of the two solvent phases along the length of the column unit. The mobile phase at the vicinity of the stopper, where the mixing effects is minimized, becomes almost free of the stationary lower phase and is then transferred to the next column unit to repeat the process. Finally, all three column units reach the hydrostatic equilibrium and thereafter the mobile phase is collected from the outlet of the column. Similar hydrodynamic process can be observed with the lower phase eluting through the inverted column as shown in FIG. 2B. In either elution mode (FIGS. 2A and 2B), samples introduced locally at the inlet of the column are continuously subjected to an efficient partition process between the two phases and separated according to their partition coefficients.
The present method can satisfactorily utilize the flowthrough coil planet centrifuges which have been developed for performing CCC with conventional two-phase solvents systems. Among various synchronous coil planet centrifuges illustrated in FIG. 3, four schemes including types J, J-L, L, and X may provide a suitable oscillating force field with sufficient strength required for phase settling.
A typical centrifugal force field generated by Type J synchronous planetary motion is shown in FIG. 4 where point O indicates the center of revolution (center of the centrifuge) and point O b , the center rotation (center of the holder). Several concentric circles indicate the location of the point on the holder, i.e., B=r/R where r is the radius of the holder and R, the radius of centrifuge arm. As shown by distribution of th centrifugal force vectors (arrows), strength of the field increases B values while accompanied by reduced amplitude of oscillation.
The design principle of the Type J centrifuge is shown in FIG. 5. A cylindical holder is equipped with a planetary gear which is coupled to an identical stationary sun gear mounted on the central axis of the centrifuge. This gear coupling produces the desired planetary motion of the holder as indicated by a pair of arrows. The coiled column 20 on the holder is replaced by the multistage mixer-settler column in the present invention.
FIG. 6 shows a cross-sectional view of a planet centrifuge (Type J) which can provide a strong oscillating centrifugal force field and therefore is useful for the present purpose. The motor 30 drives the rotary frame around the central stationary pipe 34 (shaded) via a pair of toothed pulleys 36 and toothed 38 belt. The rotary frame consists of a pair of aluminum plates rigidly bridged with links (not shown in the diagram) and holds a column holder 42 and a counterweight holder 44 in the symmetrical positions at 10 cm from the central axis of the centrifuge. The column hoder shaft is equipped with a planetary gear 48 which is coupled with an identical stationary sun gear 50 mounted around the central stationary pipe 34. This gear coupling produces the desired planetary motion of the holder 42 as was shown in FIG. 5. The multistage mixer-settler column 52 is mounted on the holder rigidly between a pair of flanges 54. The feed and return flow tubes 56 connected to the column are first led through the center hold of the holder shaft and then making a loop reach the side-hold of the short coupling pipe 58 to enter the opening of the central stationary pipe as illustrated in FIG. 6. These flow tubes can rotate freely around the central axis of the centrifuge without twisting.
The separation column based on the principle described in FIG. 2 can be made in various ways. FIGS. 7A-7C show one embodiment of the column design. The column unit in FIG. 7A is made from a glass sample bottle 62 equipped with a perforated screw cap 64 and a teflon stopper 66. The flow tubes 68 are inserted into the bottle cavity through the holes of the teflon stopper which tightly fit to the tubing. A series of column units (FIG. 7B) is arranged radially into a plastic mold which is supported between the flanges on the holder. The response of the flow tubes to high frequency vibration can be enhanced by attaching a weight 70, typically a glass of teflon bead, at the tip of the flow tube held in place with a flanged top 72 as shown in FIG. 7C. The column can also be made by making multiple cylindrical cavities directly into a inert plastic block 70 such as Kel-F (trifluoromonochloroethylene) and closing the opening with stoppers 72 equipped with flow tubes 74 as illustrated in FIG. 8.
In each separation the column is filled with the stationary phase and the sample solution is locally introduced at the inlet of the column. Then, the apparatus is rotated at a given speed typically 800-1000 rpm while the mobile phase is eluted through the column. The effluent from the outlet of the column is continuously monitored with a UV monitor and fractionated into test tubes with a fraction collector.
Various changes can be made without departing from the scope of the invention and the invention is not to be considered limited to what is described in the specification and drawings. | A method and apparatus for chromatography employ a vibration driven mixing device mounted inside a column. One end of the mixing device is held in place by a stopper while the other end is free to vibrate back and forth. The mixture at the free end is efficiently mixed while the mixture at the held end remains undisturbed. The undisturbed portion can then be removed. This invention is particularly applicable to centrifugal chromatography where the vibration is produced by high frequency oscillation in the centrifugal force field. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a demountable interior partition system, components therefor, a method of making such components, and more particularly to a unified partition system wherein readily manufactured, modular structural components may be easily assembled and disassembled with various head and base assemblies to create a variety of different screen or partition systems, and still more particularly to such a partition system with accessory supporting capabilities.
Traditionally, partition systems have been designed at various times to meet specific requirements and performance levels, which over the years has culminated in a multitude of different generally incompatible structural components and different kinds of hardware. For example, screen assemblies have been commonly designed with different requirements in mind than full height partitions, and therefore, have required different manufacturing procedures as well as their own supporting hardware. Even though the structural components are of similar construction, each often has its own configuration and is mounted in a different manner using its own variety of clips, posts, verticals and the like, notwithstanding that the function of a given part may be identical to that of another part.
As mentioned generally above, assembly of several structural components, such as panels, into a composite partition wall in accordance with prior art practice requires auxiliary panel interconnecting components such as verticals or posts as the panels are normally fabricated to be placed in edge abutting relationship. Such auxiliary components may be provided with vertically-spaced mounting slots from which accessories are hung. One of the more common auxiliary components for such panels is a U-shaped vertical that is received into channels at opposite vertical edge portions of the panels. The verticals of adjacent edge portions are secured together such as by fasteners to form a rigidly secured assembly. Providing and installing of these U-shaped verticals, however, adds considerably to the expense of the partition wall system.
An example of a partition screen assembly having similar accessory support capabilities may be seen in applicant's assignee's U.S. Pat. No. 3,886,698, dated June 3, 1975. In such partition assembly, panels are provided at their vertical mounting edges with reinforced flanges which in turn are provided with vertically-spaced mounting slots from which the accessories are hung. Heretofore, the reinforced flanges required forming by expensive press-brake bending or when separate verticals are employed by extrusion techniques to assure the required strength and alignment of the slots provided in the reinforced flanges, rather than roll-forming techniques where tolerances are less exacting but production capabilities greatly increased.
Another drawback in previous assemblies of the type described is that the number of interfitting parts makes it a difficult and time-consuming job first to assemble and then install or reinstall the partitions. Moreover, the use of fastening members or certain types of panel connecting keys present time-consuming assembly and disassembly problems, most of which require the removal of panels or post caps for access. The removal and replacement of such parts can wear the surface finish, particularly when a tool such as a screwdriver is employed. Examples of such verticals and key connected partition systems may be seen in Bohnsack U.S. Pat. Nos. 3,120,031 or 3,180,457.
SUMMARY OF THE INVENTION
This invention provides a unified modular partition system comprises of a family of design and functionally compatible, structural components which are simple in construction, few in number, and which may be readily assembled into a variety of screen or full height partition systems.
The panel system of the invention is characterized by a demountable panel construction formed of spaced-apart face plates. Each face plate is bent inwardly at its vertical edge and then upon itself to form double thickness, vertically extending, recessed J-shaped flange and terminates in outturned connecting edges by which reversely positioned face plates are interconnected. Fasteners hold together the juxtaposed connecting edges to secure adjacent face plates together. With such an arrangement, partition panels having reinforced mounting panel edges may be employed in either partition wall or screen assemblies. The various other modular structural components of the invention include at least one such mounting panel edge of similar shape for interconnection of the same at such mounting edges to provide any variety of partition layouts.
The recessed J-shaped flanges of the panel face plates as above described have a plurality of vertically-spaced mounting slots provided in the folded recessed flanges from which accessories may be hung. According to the method of the invention, such face plates are made first by forming a double parallel row of slots in the edges of planar sheet metal blanks with the slots of one row larger than those in the other. The edge is then roll-formed into a double-thickness flange such that the smaller slots of one row are aligned with any portion of the larger slots of the other row. Accurate and precise alignment of the slots is then no longer required.
According to another embodiment of the invention, an integrated demountable panel construction comprises spaced-apart face plates, each having inturned vertical edge flanges which terminate in outturned connecting edges by which opposite face plates are interconnected. Separate vertical elements include central channels enclosing the outturned connecting edges to secure the face plates together. The vertical elements further have edge flanges which form J-shape projections extending from each inturned vertical flange of the face plates, and may be provided with vertically spaced mounting slots from which accessories may be hung. With such integrated construction, the bent edges and separate vertical elements combine to define reinforcing mounting panel edges of similar shape and compatible with the mounting panel edges of the aforenoted demountable panel construction. Accordingly, panels of either construction may be used interchangeably in the partition system.
The demountable panel construction of the invention is further characterized by the recessed J-shape flanges of the panel edges which may be juxtaposed and secured together by an elongated plastic connector strip. The connector strip has a central U-shaped body or bight portion adapted to embrace and hold together the juxtaposed J-shape flanges. The connector strip further has at least one flexible wing extending laterally of the central body portion into close proximity or sealing engagement with the inturned edge flange of the panels to conceal, yet allow access to, the mounting slots for the hanging of accessories thereform. The connector strip may be a plastic coextrusion with the plastic of the wings being more flexible than the plastic of the central body portion.
It is accordingly a principal object of this invention to provide a unified partition system comprised of relatively few and easily constructed modular structural components which are design and functionally compatible and may be easily assembled and disassembled in any of a variety of partition systems.
It is another principal object of the invention to provide an improved demountable panel construction having integral, strengthened mounting edges that may be used in either wall or in screen assemblies with or without supporting structural posts.
It is still another principal object of the invention to provide a demountable panel construction including an elongate plastic connector strip for quickly and easily fastening the mounting edges of adjacent structural components together.
It is yet another object of the invention to eliminate to a significant extend the use of high cost metal extrusions or press formed components.
It is a further object of the invention to provide a partition system that may be manufactured by a single inexpensive system in areas having a low skill working force.
It is still a further object of the invention to facilitate the assembly and disassembly of partition panel assemblies.
A further important object is the provision of a partition system where the panels or components may be held together solely by a multi-purpose plastic strip.
It is also an important object to provide such strip fastening system which is completely accessible from the exterior of the panel not requiring the removal of parts for access to connectors.
To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed drawings:
FIGS. 1-4 disclose a preferred panel face plate in accordance with the invention and its method of fabrication;
FIG. 5 discloses two such face plates assembled back-to-back to form a screen or wall panel mono-element;
FIG. 6 discloses an alternative form of panel in accordance with the present invention;
FIGS. 7-11 disclose various other modular structural components and their constructions which make up a family of modular components in accordance with the invention;
FIG. 12 is an enlarged horizontal section showing a preferred panel connector strip in accordance with the invention by which adjacent structural components may be interconnected;
FIG. 13 is a perspective elevation and in FIGS. 14-25 various horizontal sections relating to a particular full height partition assembly showing exemplary intersections between the various modular components in accordance with the invention; and
FIGS. 26-30 relates to various other exemplary intersections between the various modular components in accordance with the invention.
More particularly:
FIG. 1 is a plan view of a preferred panel face plate prior to its being formed in accordance with the invention;
FIG. 2 is a front elevation of the formed panel face plate constructed in accordance with the invention;
FIG. 3 is a side elevation of the face plate of FIG. 2 as seen from the plane of line 3--3 thereof;
FIG. 4 is a top view of the face plate of FIG. 2 as seen from the plane of line 4--4 thereof;
FIG. 5 is a fragmentary, broken perspective of a demountable panel construction in accordance with the invention employing two face plates of the type shown in FIGS. 2-4;
FIG. 6 is a fragmentary, broken perspective of an alternative panel construction in accordance with the invention;
FIG. 7 is a schematic section of a door panel construction utilized in the partition assembly of the invention;
FIG. 8 is a schematic section of an alternate door panel construction utilized in the partition assembly of the invention;
FIG. 9 is a schematic section of an adjustable half panel or end filler panel construction utilized in the partition assembly of the invention;
FIG. 10 is a schematic section of a two-way, curved corner panel construction utilized in the partition assembly of the invention;
FIG. 11 is a schematic section of a three-way, curved corner panel construction utilized in the partition assembly of the invention;
FIG. 12 is an enlarged fragmentary horizontal section illustrating the intersection between the mounting edges of adjacent demountable panels employing a preferred panel connector strip in accordance with the invention;
FIG. 13 is a fragmentary perspective elevation of a particular interior partition layout in accordance with the present invention employing the various modular components of the invention;
FIG. 14 is a fragmentary schematic section taken from the line 14--14 of FIG. 13 illustrating a utility panel construction in accordance with the invention;
FIG. 15 is a fragmentary schematic section taken from the line 15--15 of FIG. 13 illustrating the jamb side of an exemplary door unit assembly in accordance with the invention;
FIG. 16 is a fragmentary schematic section taken from the line 16--16 of FIG. 13 illustrating an exemplary three-way panel intersection in accordance with the invention;
FIG. 17 is a fragmentary schematic section taken from the line 17--17 of FIG. 13 illustrating an exemplary intersection between two glass panel assemblies in accordance with the invention;
FIG. 18 is a fragmentary schematic section taken from the line 18--18 of FIG. 13 illustrating the upper portion of the hinge side of an exemplary partial height door unit assembly in accordance with the invention;
FIG. 19 is a fragmentary schematic section taken from the line 19--19 of FIG. 13 illustrating the lower portion of the jamb side of another exemplary partial height door unit assembly;
FIG. 20 is a fragmentary schematic section taken along the line 20--20 of FIG. 13 illustrating the upper portion of an exemplary intersection between a door unit assembly and chair rail assembly in accordance with the invention;
FIG. 21 is a fragmentary schematic section taken along the line 21--21 of FIG. 13 illustrating the upper portion of an exemplary intersection between a chair rail assembly and solid panel in accordance with the invention;
FIG. 22 is a fragmentary schematic section taken along the line 22--22 of FIG. 13 illustrating the lower portion of the exemplary intersection of FIG. 21;
FIG. 23 is a fragmentary schematic section taken along the line 23--23 of FIG. 13 illustrating an exemplary end filler panel assembly in accordance with the invention;
FIG. 24 is a fragmentary schematic section taken along the line 24--24 of FIG. 13 illustrating an exemplary two-way curved corner panel assembly in accordance with the invention;
FIG. 25 is a fragmentary schematic section taken along the line 25--25 of FIG. 13 illustrating an exemplary three-way curved corner panel assembly in accordance with the invention;
FIG. 26 is a fragmentary schematic section of an exemplary flexible corner partition assembly in accordance with the invention;
FIG. 27 is a fragmentary schematic section of an exemplary screen partition assembly showing the intersection between adjacent panels in accordance with the invention;
FIG. 28 is a fragmentary schematic section of an exemplary wall or screen partition assembly showing a two-way construction in accordance with the invention;
FIG. 29 is a fragmentary schematic section view of an exemplary wall or screen partition assembly showing a form of corner post construction in accordance with the invention; and
FIG. 30 is a schematic section of a wall or screen assembly using a corner cap.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in greater detail to the drawings, and initially to FIG. 5, there is designated generally by reference number 10 a unified, demountable panel constructed in accordance with the invention. The panel 10 is constructed from a pair of substantially parallel, spaced-apart metal face plates 11 of a preferably thin gauge sheet metal having substantially rectangular planar central portions 12 and opposite edge portions 14. The space between central portions 12 may be reinforced by a honeycomb or rib structure and/or filled with suitable fire and sound insulating material such as rock wool, foamed plastics, etc., whereby the panel may meet the various strength and fire resistance codes.
As best seen in FIGS. 2-5, each edge portion 14 of the face plates 11 is bent inwardly to define web portions 15 extending the full height of the metal plates 11. The web portions 15 extend substantially perpendicular to central portions 12. Edge portions 14 are further bend outwardly from web portions 15 and are reversely folded to define recessed, J-shaped flanges 16 having main double folded portions 18, intermediate double folded portions 19 and terminal folded portions 20. Main folded portions 18 extend outwardly from web portions 15 substantially perpendicular thereto. Intermediate folded portions 19 extend outwardly from main folded portions 18 substantially perpendicular thereto, and accordingly parallel to web portions 15. Terminal folded portions 20 extend inwardly from intermediate folded portions 19 and outwardly away from main folded portions 18, thereby being inclined back toward the web portions 15. Preferably, the terminal folded portions 20 approach but do not intersect a plane through the corners 21 of the face plates at 45° to the plane of the face plates 12. Preferably, the terminal folded portions 20 are inclined at 45° to the central portions 12 of the face plates. The terminal folded portions 20 terminate at terminal folded portion edges 22 which are spaced outwardly from web portions 15 to define recesses 23. Longitudinally-spaced slots 24 are formed through main folded portions 18 of the recessed flanges 16 and are in the backs of the recesses 23. The edge portions 18 extend further inwardly from recessed flanges 16 to form inner web portions 26 which extend substantially from web portions 15. The inner web portions 26 terminate in outwardly bent terminal connecting flanges 28 which extend substantially perpendicular to inner web portions 26.
The face plates 11 with the configuration described are reversely positioned with the central portions 12 thereof spaced apart, and with the terminal flanges 28 thereof juxtaposed or butted so as to form panel 10 with mounting panel edges 29. Abutting terminal flanges 28 are then secured together by suitable fasteners such as elongate clips 30, only one of which is shown at the right-hand side of the panel 10 of FIG. 5. The clip 30 is comprises of U-shape portions 31 which are adapted to enclose and hold together the juxtaposed terminal flanges 28. The U-shape portions 31 are maintained in spaced-apart relationship by flange portions 32 which extend outwardly substantially perpendicular from the tops of the stems 34 of the U-shape portion substantially along the length of terminal flanges 28. The stems 34 of the U-shape portions 31 are of sufficient length so that the flange portions 32 abut substantially the inner web portions 26 when properly in position. The inner edges of the flange portions 32 form slots intermediate the U-shape portion through which the butted terminating flanges 28 extend. As shown in FIG. 5, the butted terminated flanges 28 are cut as with sheet metal shears adjacent the U-shape portions 31, and the tabs 35 formed thereby are bent outwardly away from one another so as to overlap flange portions 32 of the clip 30 thereby locking the same in place. Alternatively, those portions of the butted terminal flanges 28 extending through the slots intermediate the U-shape portions 31 need only be mechanically deformed, for example as by twisting, to prevent passage of the same through the slots to maintain the clip in place. Obviously, the butted terminal flanges 28 could also be secured together by other fasteners, such as rivets, screws, other clips, or welding. Even the clips employed may be secured to the flanges by fasteners rather than by the deformed edge as illustrated.
It should be appreicated that the bending and folding of the sheet metal face plates 11, and their manner of securement together, provides opposite mounting panel edges 29 which are very strong and capable of serving as structural supporting members themselves with or without structural posts. Accordingly, such panel 10 can be used as a wall panel with or without structural posts or a screen panel with or without such posts as is customary in interior partition assemblies. This will become more evident as the discussion of the invention proceeds.
With reference to FIG. 1 which shows the sheet metal face plate 11 prior to forming, there are formed in the opposite edges 14 of the planar sheet inner and outer parallel rows of longitudinally-spaced slots, 36 and 37, respectively. The slots of the outer rows 37 are larger in size than those of the corresponding inner rows of slots 36. When bent and folded by roll forming, the larger slots of the outer rows 37 are aligned behind the smaller slots of the inner rows 36 to form the slots 24 in the recesses flanges 16. No longer is exact alignment required because the smaller slots of rows 36 need only fall in alignment with any portion of the larger slots of rows 37. Although either row of slots may have the larger slots, it is preferred for aesthetic reasons that the outer row 37 have the larger so that they are hidden behind the smaller slots of the row 36.
As should be apparent from FIG. 1, the inner web portions 26 and connecting flanges 28 need not extend the entire length of the face plate 11. The face plate 11 further may be provided with top and bottom inwardly folded flanges 38 and 39 along the upper and lower edges thereof for stiffening or to facilitate assembly with ceiling and floor channels, for example.
Referring now to FIG. 6, in another fabricating embodiment, an intregrated panel construction is designated generally by reference numeral 40. The panel 40 is constructed from a pair of substantially parallel spaced-apart light gauge sheet metal face plates 41 having substantially rectangular planar central portions 42 and opposite edge portions 44. The space between central portions 42 of face plates 41 may be filled as above described. Each edge portion 44 of face plates 41 is bent inwardly to define web portions 45 extending the full length of face plates 41. Web portions 45 extend substantially perpendicular to central portions 42. The web portions 45 terminate in connecting folded flanges 46 which extend outwardly substantially perpendicular to web portions 45.
The above described face plates 41 are reversely positioned with central portions 42 thereof spaced apart, and with connecting flanges 46 juxtaposed. Juxtaposed connecting flanges 46 are then secured together by vertical member 48 which extends substantially the height of the face plates 41.
Vertical member 48 is of heavier gauge sheet metal or may be an extrusion and has a central channel 49 which encloses connecting flanges 46 to hold them together. The vertical member 48 is bent outwardly at the edges of the central channel to define web portions 50 which extend substantially perpendicular thereto. When assembled, the web portions 50 are adjacent to and extend substantially parallel to the web portions 45 of the face plates 41. The web portions 50 of the vertical members 48 terminate at outwardly bent edge flanges 52. The edge flanges 52 form J-shape projections and include main portions 53, intermediate portions 54 and terminal portions 55. Main portions 53 of the edge flanges 52 extend outwardly substantially perpendicular to web portions 50. Intermediate portions 54 extend outwardly away from the main portions 53. Terminal portions 55 extend inwardly from intermediate portions 54, thereby being inclined back toward the web portions 45 of the face plates. The terminal portions 55 terminate at edges 58 which are spaced outwardly from the web portions to define recesses 59. Longitudinally-spaced slots 60 are formed in main portions 53 of the vertical member and are in the back of recesses 59.
It should be appreciated that bent edge portions 44 of the face plates 41 and the vertical members 48 combine to form reinforced mounting panel edges 61 which are very strong and capable of serving as structural supporting members themselves with or without metal posts commonly employed in partition screen assemblies.
It should also be appreciated that unified panel 10 and integrated panel 40 have respective outwardly extending, recessed, J-shape flanges 16 and 52 of like shape and accordingly may be used interchangeably in the overall partition system of the present invention.
While the panel of FIG. 5 is preferred, the panel of FIG. 6 may be substituted where the skill and investment for roller die tooling is not available.
CONNECTOR STRIPS--FIG. 12
Referring now to FIG. 12, the intersection of two adjacent screen or wall panels can be seen. Although the following description would apply to connections between panels of either of the above described construction (or between any of the below described modular components), only the details of the connection between panels 10 is shown for the sake of convenience. The panels 10 are positioned in in-line relationship with central portions 12 of the face plates forming the partition wall surfaces. The mounting panel edges 29 of the panels 10 are adjacent one another with the intermediate folded portions 19 of the recessed J-shape flanges 16 juxtaposed. The J-shape flanges 16 of adjacent panels then may br readily joined together by connector strips 70 preferably on both sides of the panels.
The connector strip 70 of the invention is preferably a plastic extrusion having a central U-shape body 71, the legs of which are adapted to embrace and hold together the adjacent J-shape flanges 16 of the panels along their full vertical height. The U-shape portion 71 is formed with a bight portion 73 and inwardly extending legs 74 having inturned edges 75 which extend over the terminal folded portion edges 22. The U-shape body 71 is sufficiently flexible, although relatively stiff, to allow placement of the connector strip 70. The strip is also sufficiently rigid to provide for securely holding the panels together. The connecting strip 70 readily can be attached to the J-shape flanges 16 by starting the strip at top or bottom of the panel plates and depressing the same over the flanges 16 along the length thereof in zipper-like fashion. The dimensions of the strip are such that at least two continuous seal lines are provided for the full height of the partition.
The connector strip 70 is also formed with flanges or wings 76 extending outwardly from the bight portion 73. The wings 76 span across recess 23 toward web portions 15 of the panels for overlying and concealing slots 24 in main folded portions 18. Preferably, the distal ends of the wings are spaced apart a distance greater than that between web portions 15 of the adjacent panels so that they are partially inwardly flexed. The wings 76 may readily be deformed inwardly for attaching a mounting member such as support bracket 77 for an accessory. The panels 10 may also be clad with an optional surface material 78, i.e., fabric, wood veneer, vinyl, etc. In such case, the wing is inwardly deformable to account for the decreased spacing between opposite web portions 15 of adjacent panels. Connector strips 70 also provide a decorative recessed covering which hides the vertical slots and presents a pleasing appearance. The connecting strips also provide a sound and light barrier between opposite sides of the panels.
The connecting strip 70 is preferably a plastic coextrusion with the plastic of the wings being more flexible than the plastic of the central body portion. The strip may be compounded from a variety of materials such as vinyl in any desirable color for complementing the decorative surface color provided on the metal face plates. Contrasting colors have been found to give the assembled wall partition a pleasing delineated effect.
Additional Modular Components--FIGS. 7-11
It will be appreciated that the above described panel constructions and interconnection therebetween from the basis for a family of modular components constructed in accordance with the invention. The remaining modular components which may form the family are shown in FIGS. 7-11. It will be appreciated that each modular component includes at least one mounting panel edge similar in shape to the above described mounting panel edges for interconnection thereat with adjacent structural components. From this family of modular components, any variety of floor plans can be assembled in either full or screen height systems. Of course, other modular components may exist or be developed in addition to those illustrated and described.
FIG. 7 shows a door frame 80 constructed in accordance with the invention. The door frame 80 includes substantially parallel, spaced-apart metal face plates 81 having central portions 82 and opposite edge portions 83 and 84. The edge portions 83 are formed the same as the edge portions 14 of the panel 10 and include J-shaped recessed flanges 86 and terminal flanges 87 of like construction. Accordingly, such door side panel 80 may be connected at edge portions 83 as by connector strip 70 to panel 10 or any other panel provided with a like edge construction. Opposite edge portions 84 are bent reversely and inwardly to define arms 88 having inwardly extending edge restrictions 89. The rebent portions 88 terminate in inwardly extending web portions 90 which extend substantially perpendicular to central portions 82. The web portions 90 terminate in outwardly bent connecting flanges 92 which extend substantially perpendicular to the web portions 90.
The face plates 81 of the above-described construction are reversely positioned with the central portions 82 thereof spaced-apart and parallel, and the respective terminal flanges 87 and 92 thereof juxtaposed so as to form door side frame panel 80. Juxtaposed connecting flanges 87, 92 may be secured together in the manner described in connection with panels 10. When so assembled, the arms 88 of the face plates 81 form a relatively deep channel 93 and edge portions 83 form reinforced mounting panel edges 94.
In FIG. 8, there is shown another form of door frame panel constructed in accordance with the invention which is designated generally be reference numeral 100. Door panel 100 is constructed from a pair of substantially parallel, spaced apart face plates 101 and 102. Face plate 101 has central portion 103 and opposite edge portions 104 and 105. Face plate 102 has central portion 106 and opposite edge portions 107 and 108. Edge portions 104 and 107 of the respective face plates 101 and 102 are formed in identical manner as edge portions 14 of face plates 11 of panel 10. Accordingly, edge portions 104 and 107 have respective recessed J-shaped flanges 110 and 111 and respective connecting flanges 112 and 113. The opposite edge portion 105 of face plate 101 is reversely folded to define door jamp portion 115 and then rebent back toward central portion 103 to define inturned edge restriction 116. The inturned edge restriction 116 terminates in web portion 117 which is bent inwardly and extends substantially perpendicular to central portion 103. Edge portion 108 of the other face plate 102 is similarly formed to edge portion 105, but without a reversely folded jamb portion 115. Accordingly, edge portion 108 has inturned edge restriction 118 and web portion 119.
The face plates 101 and 102 are reversely positioned with central portions 103 and 106 spaced apart and parallel. The connecting flanges 112 and 113 of the respective face plates 101 and 102 are juxtaposed and may be secured together by suitable means such as described above. The web portions 117 and 118 of the opposite edge portions 105 and 108 overlap one another and may also be secured together by any suitable means. A spacer member 120 is provided nearest the opposite edge portions 105 and 108 to ensure proper spacing of the central portions 103 and 106 thereat. The spacer member 120 includes a spacer portion 121 which extends substantially perpendicular to the central portions 103 and 106 and is of a width equal the spacing between the interior surfaces of such central portions. The spacer portion 121 terminates in flanges 122 which extend substantially perpendicular to the spacer portion 121 and abut central portions 103 and 106.
Referring now to FIG. 9, there is shown an end filler or half panel 140. The half panel 140 is constructed from a pair of sheet metal face plates 141 each having central planar portions 142, edge portions 143 and opposite edge portions 144. Edge portions 143 of face plates 141 are bent and folded in like manner as edge portions 14 of panel 10. Accordingly, there is formed recessed J-shaped flanges 146 and connecting flanges 147. Edge portions 144 of face plates 141 are reversely inwardly folded to form double thickness terminal edges 148. The face plates 141 of such configuration are reversely positioned with the central portions 142 thereof spaced apart. Juxtaposed terminal flanges 147 may be secured together by suiable fasteners, such as by clip 30 shown in FIG. 5. The double thickness terminal edges 148 may be maintained in spaced-apart relationship by a suitable core or filler.
The inner surfaces of the folded edges 148 are preferably spaced-apart by an amount substantially equal to the thickness of the panels 10. Without a core or filler, an adjustable panel may then be formed by telescopically inserting one end of a panel 10 between the face plates 141 of half panel 140. The extent of overlapping of the panel 10 with half panel 140 will determine the width of the composite panel formed thereby. Reference may be had to FIG. 23 where such an adjustable composite panel is shown and used as an end filler and which will be described in greater detail below.
Referring now to FIG. 10, there is shown a two-way curved corner panel 170 which is constructed with inner and outer curved face plates 171 and 172 which are concentrically arranged. Inner face plate 171 has curved central portion 173 and opposite edge portions 174. The edge portions 174 are bent radially outwardly yet inwardly of the panel to define web portions 175 extending the full height of the face plate 171. Edge portions 174 are further bent inwardly from web portions 175 and then again to form flanges 176 which extend parallel to web portion 175. The outer face plate 172 has curved central portion 177 and opposite edge portions 178. The edge portions 178 are bent radially inwardly from curved portion 177 to form web portions 179. Edge portions 178 are further bent inwardly and then again to define flanges 180 which extend parallel to web portions 179.
The inner and outer face plates 171 and 172 are reversely positioned with the curved central portions 173 and 177 thereof concentrically arranged, and with flanges 176 and 180 in overlapping relationship. When properly positioned, there is formed by the flanges 176 and 180 outwardly opening channels 182. The channels 182 are adapted to receive vertical elements 183 which are U-shaped. The distal arms of the U-shaped element 183 form J-shaped flanges 186 whereby such curved corner panel may be connected to adjacent panels as by connector strip 70 in the before described manner. The vertical elements are adapted to snugly fit in channel 182 with the base thereof in abutment with overlapping flanges 176 and 180. The vertical element 183 and face plates 171 and 172 may be readily secured together at the base of the channel 182 by suitable fasteners.
It should be appreciated that instead of the above-described construction of edge portions 174 and 178, such could instead be formed in the same manner as the edge portions 14 of panels 10, but additional roll tooling would be required to form the major curve of the face plates and the volume in such components may not warrant the investment in such tooling.
Moving now to FIG. 11, there is shown a three-way curved corner panel 190 which is constructed with planar face plate 191 and curved face plates 192. Planar face plate 191 is identical in construction to face plate 11 of panel 10 but is of a substantially lesser width. Accordingly, the planar face plate includes central planar portion 193 and edge portions 194, the edge portions having J-shaped flange 195 and connecting flange 196. Curved face plates 192 have curved central portions 197 and edge portions 198. Edge portions 198 are bent inwardly (radially outwardly) similar to edge portion 194 and have J-shaped flanges 199 and connecting flanges 120. The terminal flanges 196, 120 of adjacent face plates are positioned in abutting arrangement and secured to form the panel 190.
It will again be appreciated that FIGS. 10 and 11 show two different forms of the curved corner face plates, one (FIG. 11) wherein the edges are roll formed, and the other (FIG. 10) wherein the edges are not. Such face plates and the modules formed thereby may be used interchangeably in the systems of the invention.
An Exemplary System--FIGS. 13-25
Referring now to FIG. 13, there is illustrated a full height partition system constructed in accordance with the invention employing the above-described family of modular components. Such partition construction may extend from the floor 200 to a suspended ceiling 201 and comprises, reading from left to right, a three-way curved corner panel assembly 203 made up of three-way curved corner panel 204 and solid panels 205-207. In line with solid panel 207 and connected thereto is utility panel 208 which in turn is in line with and connected to solid panel 209. Solid panel 209 is in line with and connected to full-height door unit assembly 210. Full-height door unit assembly 10 comprises door frame panels 212, 213 and full height door 214. Further in line with utility panel 209 and full-height door unit assembly 210 is another solid panel 217 which forms a three-way intersection with yet another solid panel 219 and glass panel assembly 220. Glass panel assembly 220 extends in a direction normal to solid panels 217, 219, and along with in-line glass panel assemblies 221-224, forms a substantially transparent partition wall. Each glass panel assembly, such as glass panel assembly 223, comprises a pane of glass 228 extending between frame panels 229 and 230.
Moving now to the more distant partition walls of FIG. 13, there is shown a partial height door unit assembly 240 comprised of door panels 241, 242, lintel panel 243 and door 244. Door panel 241 is connected in-line to solid panel 245 while door panel 242 is connected at a three-way intersection to another solid panel 247 and chair rail assembly 248. Such chair rail assembly 248 extends normal to door panel 242 and solid panel 247 and comprises frame panels 250, 251, chair rail panel 252 and glass panel 253 mounted above chair rail panel 252 and between frame panels 250, 251. The chair rail assembly 248 is connected at frame panel 251 to another partial height door unit assembly 255 which comprises door panel 256, frame panel 257, lintel panel 258, and door 259. Continuing from left to right, the door unit assembly 255 is connected in-line to another chair rail assembly 260 which comprises frame panels 261, 262, chair rail panel 263, and glass panel 264. The frame panel 262 is connected in line with solid panel 266 which forms two-way curved panel assembly 268 along with two-way curved corner panel 269 and solid panel 270 extending normal to solid panel 266. Finally, there is shown an end filler panel assembly 274 comprised of half-panel 275 and solid panel 276 which abut against solid panel 277 in a direction normal thereto.
Now referring to the manner in which the various components may be secured together, reference may be had to FIGS. 14-25. Referring first to FIG. 14, it may be seen that utility panel 208 may be secured at its mounting edges 280 to respective mounting edges 282 and 283 of solid panels 207, 209 as by connector strips 70 in the above described manner. The utility panel 208 is essentially a hybrid of above-described panel 10 and comprises a pair of face plates 286 and 287. Face plate 286 is of identical construction as the face plates 11 of panel 10. Face plate 287, however, has formed in its central portion 289 intermediate its rolled edge portions 290 a U-shaped channel 292 which may house, for example, electrical conduit and the like. The channel 292 includes sides 293 which extend substantially perpendicular to the faces 294 of the central portion 289 and base 295 which extends parallel to such faces. As shown, the base 295 may be substantially in abutment with planar central portion 298 of face plate 286. After necessary utility connections are made, a cover plate 299 may be secured to the face plate 287 to conceal the channel 292 as well as its contents. Such cover plate 299 includes planar face portion 300 which extends substantially the full width of the face plate 287. The edges of the face plate 300 are reversely folded and then bent inwardly to form flanges 302 which interfit within the channel 292. The flanges 302 are bent at their ends to form terminal flanges 304, which extend parallel to and adjacent the base 295 of the channel 292. The cover plate 299 thereby may be readily secured to the face plate 287 by a suitable adhesive or magnetic tape 306 applied to the terminal flanges and brought into contact with the base 295 of the channel 292. With reference to FIG. 13, the cover plate 299 may be provided with suitable openings for electrical wall sockets 308 or the like.
In FIG. 15, there is shown the jamb side of door unit assembly 210. Connector strips 70 are again employed to secure door frame panel 212 to solid panel 209 at their respective mounting edges 321 and 322 in the above described manner. Affixed at the other edge 323 of door panel 213 is a vertically extending door jamb 324 of the configuration shown which comprises body portion 325 and door stop portion 326. Body portion 325 includes inwardly directed spring leg portions 326 and 327 that snap over the inturned edge restrictions 328 of the door frame panel to secure the door jamp 324 to the door frame panel. The door stop portion 326 may have attached inside its folded distal end a resilient bumper and door seal 327 against which the door 215 closes.
FIG. 16 shows an exemplary three-way intersection between solid panels 217 and 219 and frame panel 233 of glass panel assembly 220. Solid panels 217 and 219 are secured at their respective mounting edges 330 and 331 by connector strips 70. To provide a mounting edge to which frame panel 233 can be secured, a vertically extending channel-shape element 334 is secured to a recessed flange of one of the panel mounting edges such as recessed flange 335 of mounting edge 330 by bracket or key 336. Key 336 may have suitable hook tabs 550 which engage in aligned slots provided in recessed flange 335 and channel-shape element 334. Preferably, several such keys 336 are vertically spaced along the length of the panels rigidly to secure the channel 334 thereto. The channel 334 has a main body portion 337 which spans the gap 338 between adjacent panels 217 and 219. The vertical edges of the main body portion 337 are bent outwardly away from the faces of panels 217 and 219 to define J-shaped edge flanges 339. The J-shaped flanges 340 of frame panel 233 are secured to J-shaped flanges 339 by connector strips 70. As shown, glass pane 232 may be secured along its vertical edge in central channel 342 of glazing frame panel 233 by glazing strip 343.
FIG. 17 shows an exemplary two-way in-line intersection between adjacent glass panel assemblies 222 and 223. The frame panel 229 comprises two frame panels 233 which are reversely positioned and secured together at their mounting edges 350 by connector strips 70. The glass panes 232 of the glass panel assemblies 222 and 223 may be secured in the frame panel central channels 352 by glazing strips 353.
Turning now to FIG. 18, there is shown the upper portion of an exemplary intersection between chair rail panel assembly 252 and partial height door unit 255. Door frame panel 256 and frame panel 251 are secured together at their respective mounting edges 360 and 361 by connector strips 70. Lintel panel 258 is of a construction similar to the solid panels such as shown in FIG. 5 but has a height sufficient to fill the space between door 259 and ceiling 201. The lintel panel 258 may be interconnected to door panel 256 by fitting the recessed flanges 363 behind channel edge restrictions 364 of the panel 256. This may conveniently be done by endwise inserting the recessed flanges 363 behind the edge restrictions 364 at one end of the door panel 256 and slidably moving such panels relative to each other into their proper relationship prior to assembly of the same into the partition wall.
FIG. 19 shows the jamp side of partial height door unit 240 which employs door frame panel 241 of like construction as the door panel 100 shown in FIG. 8. Door panel 241 is secured to solid panel 245 at the respective mounting edges 370 and 371 by connecting strips 70. At the other edge 373 of door panel 241 is door jamp 374 of the configuration shown. Affixed to the door jamb portion 375 of door panel 241 is a bumper and door seal 376 against which the door 244 closes. The dove-tail channel of the door frame includes a snap-in insert or filler 377 so that the frame has a recessed edge 378 in the plane of the door 244 when closed.
FIG. 20 shows the intersection of door frame 251 to glazing frame panel 261 of chair rail assembly 260. Such panels are fastened together at their adjacent mounting edges by connector strips 70. The bottom of the glass panel is supported by a glazing frame 387, which is the same as frame 251, which also then becomes the chair rail.
FIG. 21 shows the intersection between frame panel 262 and solid panel 266. The same may be fastened together at their adjacent mounting edges again by connector strips 70. It is noted that FIG. 21 is simply the reverse of FIG. 20.
FIG. 22 shows the lower portion of the intersection between chair rail assembly 260 and solid panel 266. The frame panel 262 is secured to solid panel 266 at the adjacent mounting edges by connector strips 70. The chair rail panel 263 comprises face plates 391 having inturned edge portions 392 which terminate in outwardly bent terminal flanges 393 adapted to interfit within central channel 394 of the frame panel 262.
FIG. 23 shows the end filler assembly 274. Solid panel 276 is telescoped within the open end of half panel 275 and adjusted so that the mounting edge 399 of half panel 275 is adjacent solid panel 277. An elastomeric gasket 400 is positioned between mounting edge 399 and solid panel 277. Gasket 400 preferably extends the full length of mounting edge and includes central portion 401 spanning the J-shaped flanges 402. Gasket 400 has inclined flange portions 403 overlying the flanges 402 and flexible wings 404 extending oppositely the flange portions 403 into sealing engagement with solid panel 277. There may also be provided wing portions 405 on flange portions 403 which substantially span across mounting spaces 405 of half panel 275 to conceal slots in the J-shape flanges 402. Once the half panel face plates are in place, they may be secured to the exterior of the solid panel 276 by the double sided adhesive tape shown at 408.
FIG. 24 shows the two-way curved panel 269 secured to adjacent solid panels 266 and 270 at their respective mounting edges again by connector strips 70. The two-way curved panel 269 is the same as the panel 170 of FIG. 10.
FIG. 25 shows the three-way curved panel assembly 203. Instead of a three-way curved panel of the type shown in FIG. 11, there is shown a three-way curved panel 205 of like shape but constructed with non-roll formed curved face plates 409 and 410 and planar face plate 411. The mounting edges formed by the face plates are similar in construction to those of the two-way curved panel of FIG. 11. Such mounting edges may be fastened by connector strips 70 to the adjacent mounting edges of panels 205-207.
Referring now to FIG. 26, there is illustrated a flexible corner or curved partition assembly designated generally by reference numeral 410. Flexible partition assembly 410 comprises a series of relatively narrow vertical elements 411 interfitting to form the partition. Each element 411 includes at one end a relatively deep female channel 412 having inturned edge restrictions 413. The opposite ends of each element 411 include outturned J-shape edge flanges 415 adapted to fit behind the corresponding edge restriction 413 of the channel 412 of the adjacent element with sufficient clearance so that each element may be positioned at a slight angle with respect to the adjacent element. The arcuate extent of the flexible corner or curved partition may be governed by the extent of the J-shape flange or the extent of the female channel in which it is received.
Screens--FIG. 27
Screens generally do not go full height floor to ceiling. Such screens may vary in height from relatively low screens to screens which almost extend to the ceiling. Such screens are generally supported on posts extending from the floor. Such screens are also generally more narrow than conventional full height partitions although they need not be. Moreover, many screens in office layouts today support accessories such as work surfaces, storage units, or filing cabinets, shelves and the like. Therefore, sturdy panels are often required in screens and there is no reason why screen partition panels cannot be of the same construction as full height partition panels.
One of the most commonly employed forms of posts for screens is shown in FIG. 27. The post 500 is circular and permits the panels connected thereto such as seen at 501 and 502 to be pivoted about the vertical axis 503 of such post. Conventionally, the panels are supported on the post by hooks, top and bottom. It will be noted that the panels 501 and 502 are identical to the monoconstruction panel seen in FIG. 5.
In order to provide an appearance cover between the panels and posts, each panel is provided with a vertically extending plastic gasket as seen at 504 and 505. Each gasket comprises a vertically extending planar base portion 506 seating against the exterior of the J-shape flanges of the panel. Extending therefrom are two legs 507 and 508 symmetrically arranged which project initially toward the post at approximately 45°. The legs then extend radially of the post and terminate in L-shape legs 509, the short leg of which snaps behind the edge 22 of the J-shape flange. Continuing from the long leg of the L is a feathered more flexible edge 510 which functions to conceal and yet provide access to the slotted recess of the panel. Again, the gasket may be a coextrusion to obtain the different required characteristics in different areas. In any event, precisely the same panel is employed as in the full height partitions.
Screen or Highwall--FIGS. 28-30
With reference to FIG. 28, some screens or partitions have panels 512 and 513 seen in FIG. 28 and are spaced and interconnected by vertically extending spring metal panel connectors seen at 514 and 515. Each panel connector has a spring leg which extends inwardly as seen at 516 and is bent to extend outwardly, such outwardly extending portion seen at 517 including a reentrant portion 518 terminating in stop flange 519 which extends parallel to the face of the panel connector. Such panel connectors or post caps are generally conventional and widely used in existing partition systems. They may be snapped in or out to provide access to the space indicated at 520 between the panels. In FIG. 28 the panels are spaced yet held together solely by the post caps. Accordingly, the universal panel of the present invention lends itself to use with old or conventional partition components.
As seen in FIG. 29, the same panels seen at 521 and 522 may be employed with post 523. Such post has a recessed relatively shallow channel 524 in each of the four faces thereof which accommodate the extending J-shape flanges as shown. In the manner indicated, the post acts as a key slot for the panels. The post nonetheless provides access to the slotted recesses for the hanging of accessories.
In FIG. 30, there is illustrated again the same partitions 527 and 528 interconnected in a two-way construction such that the interior slotted recesses are available for modular hanging capabiity as indicated at 529 and 530. To accomplish this each end of the respective panels is provided with a metal clip 531 fitting over a gasket 532, both being folded in the U-shape manner shown at 533 to clinch the flanged interior edges of the panel face plates. The gasket may be a coextrusion and includes the feathered edges seen at 534 concealing yet providing access to the recesses. The clip 531 in effect repeats the J-shape flange configuration as seen at 535 so that a corner cap or connector 536 may be secured as shown. Again the connector, as in FIG. 28, is provided with spring legs which cooperate with the repeated J-shape flanges of the clip releasably to secure the corner cap in place.
It will be appreciated that the illustrations seen in FIGS. 27-30 are exemplary only and that in each situation, one-, two-, three- or four-way connections may be employed.
It can now be seen that the present invention provides a unified product or partition system modules whereby high volume can be achieved so that the components can readily be roll formed. It will be appreciated that where the components are not roll formed, they may be should volume considerations warrant. In any event, whether roll formed or formed otherwise, the relatively few modular components fit together in an almost endless variety of high or low screens or full height partitions. Moreover, the components may all have modular hanging capability for accessories and are readily compatible with existing partition systems.
Other modes of applying the principles of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed. | An interior partition system wherein with relatively few components, most of which can be roll formed from common sets of roller dies, a wide variety of interior screens or full height partitions can be constructed, thus avoiding the necessity of the manufacture and inventory of a large number of parts. For some parts, where volume may not justify the investment in the required roll sets, other manufacturing techniques may be employed, but such parts are readily compatible with the high volume components and usable interchangeably therewith. In the preferred form, a verticaless panel is constructed having a roll formed slotted, recessed edge which includes a double thickness folded flange of special configuration so that adjacent panels may readily be secured together either with a multipurpose co-extruded plastic zipper strip which will provide the desired light and sound seal, accommodate a wide variety of surface finishes and provide an appearance cover for the recessed slots yet providing access thereto for hanging components or accessories to the screen or partition, or a spring metal panel connector. | 4 |
TECHNICAL FIELD
The present invention relates to an anode active material which may intend to improve safety of a battery.
BACKGROUND ART
A lithium ion battery is a battery such that an Li ion moves between a cathode and an anode. The lithium ion battery has the advantage that energy density is high. In contrast, a sodium ion battery is a battery such that an Na ion moves between a cathode and an anode. Na exists so abundantly as compared with Li that the sodium ion battery has the advantage that lower costs are easily intended as compared with the lithium ion battery. Generally, these batteries have a cathode active material layer containing a cathode active material, an anode active material layer containing an anode active material, and an electrolyte layer formed between the cathode active material layer and the anode active material layer.
It is known that a carbon material is used as an anode active material used for these batteries. For example, in Patent Literature 1, a nonaqueous electrolyte secondary battery is disclosed, in which lithium iron phosphate represented by Li x FePO 4 is used as a cathode active material and a carbon material such that average action potential is 0.3 V or less on the basis of lithium is used as an anode active material.
Incidentally, in Non Patent Literature 1, K 4 Nb 6 O 17 is disclosed as a photocatalyst material. Also, in Patent Literature 2, an electrode for a lithium secondary battery containing Li 4 Nb 6 O 17 as an active material for an electrode is disclosed.
CITATION LIST
Patent Literature
Patent Literature 1: Japanese Patent Application Publication (JP-A) No. 2010-231958
Patent Literature 2: JP-A No. 2001-052701 Non Patent Literature
Non Patent Literature 1: Shigeru Ikeda et al., “Effect of the particle size for photocatalytic decomposition of water on Ni-loaded K 4 Nb 6 O 17 ”, Microporous Materials 9 (1997) 253-258
SUMMARY OF INVENTION
Technical Problem
For example, with regard to the carbon material described in Patent Literature 1, average action potential is 0.3 V or less on the basis of lithium, so that the problem is that metal Li is easily precipitated. Also, examples of an anode material useful for a sodium ion battery include hard carbon, which is around 0 V in average action potential, so that the problem is that metal Na is easily precipitated. Thus, action potential of an anode active material is so low that metal is easily precipitated on the surface of the anode active material, so that the problem is that it is difficult to secure the safety of a battery.
The present invention has been made in view of the above circumstances, and a main object thereof is to provide an anode active material which can improve the safety of a battery.
Solution to Problem
In order to achieve the problems, the present invention provides an anode active material used for a sodium ion battery or a lithium ion battery, wherein the anode active material has an A 4 Nb 6 O 17 phase (A is at least one kind of H, Na and K).
According to the present invention, the A 4 Nb 6 O 17 phase acts at comparatively high electric potential, so that an improvement in safety of the battery may be intended.
In the invention, the A is preferably K.
In the invention, the A is preferably Na or H.
The present invention also provides a sodium ion battery comprising a cathode active material layer containing a cathode active material, an anode active material layer containing an anode active material, and an electrolyte layer formed between the cathode active material layer and the anode active material layer, wherein the anode active material is the anode active material described above.
According to the present invention, the use of the anode active material described above allows the sodium ion battery with high safety.
The present invention further provides a lithium ion battery comprising a cathode active material layer containing a cathode active material, an anode active material layer containing an anode active material, and an electrolyte layer formed between the cathode active material layer and the anode active material layer, wherein the anode active material is the anode active material described above.
According to the present invention, the use of the anode active material described above allows the lithium ion battery with high safety.
Advantageous Effects of Invention
An anode active material of the present invention produces the effect to improve the safety of the battery.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic cross-sectional view showing an example of a sodium ion battery or a lithium ion battery of the present invention.
FIG. 2 is a result of measuring XRD of an active material obtained in Example 1.
FIG. 3 is a schematic view showing a crystal structure of a K 4 Nb 6 O 17 phase.
FIG. 4 is a result of a charge and discharge test of an evaluation battery (a sodium ion battery) using an active material obtained in Example 1.
FIG. 5 is a result of a charge and discharge test of an evaluation battery (a lithium ion battery) using an active material obtained in Example 1.
FIGS. 6A and 6B are each a result of a charge and discharge test of an evaluation battery (a sodium ion battery and a lithium ion battery) using an active material obtained in Example 2.
FIGS. 7A and 7B are each a result of a charge and discharge test of an evaluation battery (a sodium ion battery and a lithium ion battery) using an active material obtained in Example 3.
FIGS. 8A and 8B are each a graph showing a relation between ionic radius of an A element (A=H, Na and K) and reversible capacitance in an evaluation battery (a sodium ion battery and a lithium ion battery) using an active material obtained in Examples 1 to 3.
DESCRIPTION OF EMBODIMENTS
An anode active material, a sodium ion battery and a lithium ion battery of the present invention are hereinafter described in detail.
A. Anode Active Material
The anode active material of the present invention is an anode active material used for a sodium ion battery or a lithium ion battery, wherein the anode active material has an A 4 Nb 6 O 17 phase (A is at least one kind of H, Na and K).
According to the present invention, the A 4 Nb 6 O 17 phase acts at comparatively high electric potential, so that an improvement in safety of the battery may be intended. For example, in the after-mentioned Example 1, it was confirmed that action potential of the anode active material having a K 4 Nb 6 O 17 phase was in the vicinity of 1 V. The action potential in the vicinity of 1 V is such a moderate electric potential as the anode active material as to have the advantage that battery voltage may be increased while restraining metal Na or metal Li from precipitating. Also, the anode active material of the present invention has the advantage that heat resistance is favorable by reason of being ordinarily an oxide active material.
On the other hand, in Non Patent Literature 1, K 4 Nb 6 O 17 is described but no description nor suggestion is made about an active material. Also, in Patent Literature 2, an electrode for a lithium secondary battery using Li 4 Nb 6 O 17 , not K 4 Nb 6 O 17 , as an active material is disclosed. Also, in recent years, research and development of a sodium ion battery have been actively conducted, and various materials have been proposed for a cathode active material; however, hard carbon has been reported at most for an anode active material. In the present invention, it has been first found out that an oxide with Nb, that is, the A 4 Nb 6 O 17 phase is useful as the anode active material for a sodium ion battery or a lithium ion battery.
The anode active material of the present invention has the A 4 Nb 6 O 17 phase. An A element in the A 4 Nb 6 O 17 phase is at least one kind of an H element, an Na element and a K element. The A element may be one kind of an H element, an Na element and a K element, or two kinds or more thereof. The case where the A element is an H element or an Na element has the advantage that reversible capacitance increases as compared with the case of being a K element. The presence of the A 4 Nb 6 O 17 phase may be confirmed by X-ray diffraction (XRD) measurement. Ordinarily, the A 4 Nb 6 O 17 phase preferably has typical peaks in 2θ=10.01°, 12.89°, 14.68°, 15.67°, 17.63°, 23.30°, 25.10°, 27.60°, 30.20°, 40.50° and 46.40° in X-ray diffraction measurement using a CuKα ray. Incidentally, the peak position may be within a range of ±2.00° or within a range of ±1.00°. The space group of the A 4 Nb 6 O 17 phase is preferably P21nb. Also, the crystal system of the A 4 Nb 6 O 17 phase is preferably an orthorhombic crystal.
Also, the anode active material of the present invention is preferably large in the ratio of the A 4 Nb 6 O 17 phase; specifically, the anode active material preferably contains the A 4 Nb 6 O 17 phase mainly. Here, “containing the A 4 Nb 6 O 17 phase mainly” signifies that the ratio of the A 4 Nb 6 O 17 phase is the largest in all crystal phases contained in the anode active material. The ratio of the A 4 Nb 6 O 17 phase contained in the anode active material is preferably 50 mol % or more, more preferably 60 mol % or more, and even more preferably 70 mol % or more. Also, the anode active material of the present invention may include only the A 4 Nb 6 O 17 phase (a single-phase active material). Incidentally, the ratio of the A 4 Nb 6 O 17 phase contained in the anode active material may be determined by a quantitative analysis method through X-ray diffraction (such as a quantification method by R-value and a Rietveld method), for example.
The anode active material of the present invention contains an A element, an Nb element and an O element, and has the A 4 Nb 6 O 17 phase described above. The composition of the anode active material of the present invention is not particularly limited if the composition has the crystal phase described above. Above all, the anode active material of the present invention preferably has a composition of A 4 Nb 6 O 17 and the adjacent thereof. Specifically, the anode active material preferably has a composition of A x Nb y O z (3≦x≦5, 5≦y≦7, 16≦z≦18).
The shape of the anode active material of the present invention is preferably a particulate shape, for example. Also, the average particle diameter thereof (D 50 ) is preferably, for example, from 1 nm to 100 μm, above all, from 10 nm to 30 μm.
Also, a method for producing the anode active material of the present invention is not particularly limited if the method is such as to allow the anode active material described above, but examples thereof include a solid-phase method, a sol-gel method, a spray-drying method, an atomized pyrolysis method, a hydrothermal method and a coprecipitation method. Also, the anode active material having an H 4 Nb 6 O 17 phase may be obtained by substituting part or all of the K element of the anode active material having a K 4 Nb 6 O 17 phase with an H element, for example. Also, the anode active material having an Na 4 Nb 6 O 17 phase may be obtained by substituting part or all of the H element of the anode active material having an H 4 Nb 6 O 17 phase with an Na element, for example. Examples of a substitution method include an ion exchange method.
B. Sodium Ion Battery
FIG. 1 is a schematic cross-sectional view showing an example of a sodium ion battery of the present invention. A sodium ion battery 10 shown in FIG. 1 comprises a cathode active material layer 1 , an anode active material layer 2 , an electrolyte layer 3 formed between the cathode active material layer 1 and the anode active material layer 2 , a cathode current collector 4 for collecting the cathode active material layer 1 , an anode current collector 5 for collecting the anode active material layer 2 , and a battery case 6 for storing these members. The anode active material layer 2 contains the anode active material described in the “A. Anode active material”.
According to the present invention, the use of the anode active material described above allows the sodium ion battery with high safety.
The sodium ion battery of the present invention is hereinafter described in each constitution.
1. Anode Active Material Layer
The anode active material layer in the present invention is a layer containing at least the anode active material. The anode active material layer may contain at least one of a conductive material, a binder and a solid electrolyte material in addition to the anode active material.
The anode active material in the present invention is ordinarily the anode active material described in the “A. Anode active material”. The content of the anode active material is preferably larger from the viewpoint of capacity; preferably, for example, from 60% by weight to 99% by weight, above all, from 70% by weight to 95% by weight.
Examples of the conductive material include a carbon material. Specific examples of the carbon material include acetylene black, Ketjen Black, VGCF and graphite. The content of the conductive material is preferably, for example, from 5% by weight to 80% by weight, above all, from 10% by weight to 40% by weight.
Examples of the binder include polyvinylidene difluoride (PVDF), polyimide (PI), carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR). The content of the binder is preferably, for example, from 1% by weight to 40% by weight.
The solid electrolyte material is not particularly limited as long as the material has desired ion conductivity, but examples thereof include an oxide solid electrolyte material and a sulfide solid electrolyte material. The content of the solid electrolyte material is preferably, for example, from 1% by weight to 40% by weight.
The thickness of the anode active material layer varies greatly with the constitution of the battery, and is preferably from 0.1 μm to 1000 μm, for example.
2. Cathode Active Material Layer
The cathode active material layer in the present invention is a layer containing at least the cathode active material. The cathode active material layer may contain at least one of a conductive material, a binder and a solid electrolyte material in addition to the cathode active material.
Examples of the cathode active material include bed type active materials, spinel type active materials, and olivine type active materials. Examples of the cathode active material include an oxide active material. Specific examples of the cathode active material include NaFeO 2 , NaNiO 2 , NaCoO 2 , NaMnO 2 , NaVO 2 , Na(Ni x Mn 1-x )O 2 (0<X<1), Na(Fe x Mn 1-x )O 2 (0<X<1), NaVPO 4 F, Na 2 FePO 4 F, Na 3 V 2 (PO 4 ) 3 , and Na 4 M 3 (PO 4 ) 2 P 2 O 7 (M is at least one kind of Co, Ni, Fe and Mn).
The kinds and content of the conductive material, the binder and the solid electrolyte material used for the cathode active material layer are the same as the contents described in the anode active material layer described above; therefore, the description herein is omitted. The thickness of the cathode active material layer varies greatly with the constitution of the battery, and is preferably from 0.1 μm to 1000 μm, for example.
3. Electrolyte Layer
The electrolyte layer in the present invention is a layer formed between the cathode active material layer and the anode active material layer. Ion conduction between the cathode active material and the anode active material is performed through the electrolyte contained in the electrolyte layer. The form of the electrolyte layer is not particularly limited but examples thereof include a liquid electrolyte layer, a gel electrolyte layer and a solid electrolyte layer.
The liquid electrolyte layer is ordinarily a layer obtained by using a nonaqueous liquid electrolyte. The nonaqueous liquid electrolyte ordinarily contains a sodium salt and a nonaqueous solvent. Examples of the sodium salt include inorganic sodium salts such as NaPF 6 , NaBF 4 , NaClO 4 and NaAsF 6 ; and organic sodium salts such as NaCF 3 SO 3 , NaN(CF 3 SO 2 ) 2 , NaN(C 2 F 5 SO 2 ) 2 , NaN(FSO 2 ) 2 and NaC(CF 3 SO 2 ) 3 .
The nonaqueous solvent is not particularly limited as long as the solvent dissolves the sodium salt. Examples of the high-dielectric-constant solvent include cyclic ester (cyclic carbonate) such as ethylene carbonate (EC), propylene carbonate (PC) and butylene carbonate (BC), γ-butyrolactone, sulfolane, N-methylpyrrolidone (NMP), and 1,3-dimethyl-2-imidazolidinone (DMI). Meanwhile, examples of the low-viscosity solvent include chain ester (chain carbonate) such as dimethyl carbonate (DMC), diethyl carbonate (DEC) and ethyl methyl carbonate (EMC), acetates such as methyl acetate and ethyl acetate, and ether such as 2-methyltetrahydrofuran. A mixed solvent such that the high-dielectric-constant solvent and the low-viscosity solvent are mixed may be used.
The concentration of the sodium salt in the nonaqueous liquid electrolyte is, for example, from 0.3 mol/L to 5 mol/L, preferably from 0.8 mol/L to 1.5 mol/L. The thickness of the electrolyte layer varies greatly with kinds of the electrolyte and constitutions of the battery, and is preferably, for example from 0.1 μm to 1000 μm.
4. Other Constitutions
The sodium ion battery of the present invention ordinarily comprises a cathode current collector for collecting the cathode active material layer and an anode current collector for collecting the anode active material layer. Examples of a material for the cathode current collector include SUS, aluminum, nickel, iron, titanium and carbon. Meanwhile, examples of a material for the anode current collector include SUS, copper, nickel and carbon. Examples of the shape of the current collectors include a foil shape, a mesh shape and a porous shape. In addition, examples of a method for forming the active material layers on the current collectors include a doctor blade method, an electrostatic coating method, a dip coat method and a spray coat method.
The sodium ion battery of the present invention may include a separator between the cathode active material layer and the anode active material layer. A material for the separator may be an organic material or an inorganic material. Specific examples thereof include porous membranes such as polyethylene (PE), polypropylene (PP), cellulose and polyvinylidene fluoride. The separator may be a single-layer structure (such as PE and PP) or a laminated structure (such as PP/PE/PP). A case for a general battery may be used as a battery case. Examples of the battery case include a battery case made of SUS.
5. Sodium Ion Battery
The sodium ion battery of the present invention is not particularly limited as long as the battery has the cathode active material layer, anode active material layer and electrolyte layer described above. In addition, the sodium ion battery of the present invention may be a primary battery or a secondary battery, preferably a secondary battery among them. The reason therefor is to be repeatedly charged and discharged and be useful as a car-mounted battery, for example. The primary battery includes an application as a primary battery (an application intended to use only for one discharge). Examples of the shape of the sodium ion battery of the present invention include a coin shape, a laminate shape, a cylindrical shape and a rectangular shape. A producing method for the sodium ion battery is not particularly limited but is the same as a producing method for a general sodium ion battery.
C. Lithium Ion Battery
FIG. 1 is a schematic cross-sectional view showing an example of a lithium ion battery of the present invention. A lithium ion battery 10 shown in FIG. 1 comprises a cathode active material layer 1 , an anode active material layer 2 , an electrolyte layer 3 formed between the cathode active material layer 1 and the anode active material layer 2 , a cathode current collector 4 for collecting the cathode active material layer 1 , an anode current collector 5 for collecting the anode active material layer 2 , and a battery case 6 for storing these members. The anode active material layer 2 contains the anode active material described in the “A. Anode active material”.
According to the present invention, the use of the anode active material described above allows the lithium ion battery with high safety.
Incidentally, the lithium ion battery of the present invention is basically the same as the contents described in the “B. Sodium ion battery”; therefore, only different points are hereinafter described.
Examples of the cathode active material include bed type active materials, spinel type active material, and olivine type active materials. Examples of the cathode active material include an oxide active material. Specific examples of the cathode active material include LiCoO 2 , LiMnO 2 , LiNiO 2 , LiVO 2 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 , LiMn 2 O 4 , Li(Ni 0.5 Mn 1.5 )O 4 , LiFePO 4 , LiMnPO 4 , LiNiPO 4 and LiCuPO 4 .
Examples of a supporting salt (a lithium salt) used for the electrolyte layer include inorganic lithium salts such as LiPF 6 , LiBF 4 , LiClO 4 and LiAsF 6 ; and organic lithium salts such as LiCF 3 SO 3 , LiN(CF 3 SO 2 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiN(FSO 2 ) 2 and LiC(CF 3 SO 2 ) 3 .
Incidentally, the present invention is not intended to be limited to the embodiment described above. The embodiment described above is given only for illustrative purposes, and any embodiment having substantially the same configuration as the technical idea described in the claims of the present invention and provides similar operating effects, is construed to be included in the technical scope of the present invention.
EXAMPLES
The present invention is described more specifically while showing examples hereinafter.
Example 1
K 2 CO 3 and Nb 2 O 5 as raw materials were weighed at a molar ratio of K 2 CO 3 :Nb 2 O 5 =2:3, and kneaded in ethanol. Thereafter, the solution was molded into pellets, which were burned in a muffle furnace on the conditions of 1000° C. and 12 hours. Thus, an active material having a composition of K 4 Nb 6 O 17 was obtained.
[Evaluations]
(X-Ray Diffraction Measurement)
X-ray diffraction (XRD) measurement by using a CuKα ray was performed for the active material obtained in Example 1. The results are shown in FIG. 2 . As shown in FIG. 2 , with regard to the active material obtained in Example 1, the typical peaks appeared in 2θ=10.01°, 12.89°, 14.68°, 15.67°, 17.63°, 23.30°, 25.10°, 27.60°, 30.20°, 40.50° and 46.40°, and it was confirmed that the active material contained the K 4 Nb 6 O 17 phase as the main body. Incidentally, FIG. 3 is a schematic view showing a crystal structure of the K 4 Nb 6 O 17 phase (orthorhombic crystal, space group P21nb). As shown in FIG. 3 , the K 4 Nb 6 O 17 phase has a layer structure in which an NbO 6 octahedron layer and a K layer were laminated.
(Charge and Discharge Test)
An evaluation battery using the active material obtained in Example 1 was produced. First, the obtained active material, a conductive material (acetylene black), and a binder (polyvinylidene fluoride, PVDF) were mixed and kneaded at a weight ratio of active material:conductive material:binder=85:10:5 to thereby obtain a paste. Next, the obtained paste was coated on a copper foil by a doctor blade, dried and pressed to thereby obtain a test electrode having a thickness of 20 μm.
Thereafter, a CR2032-type coin cell was used, the test electrode was used as a working electrode, metallic Na was used as a counter electrode, and a porous separator of polypropylene/polyethylene/polypropylene (a thickness of 25 μm) was used as a separator. A solution in which NaPF 6 was dissolved at a concentration of 1 mol/L in a solvent, in which EC (ethylene carbonate) and DEC (diethyl carbonate) were mixed by the same volume, was used as a liquid electrolyte.
Next, a charge and discharge test was performed for the obtained evaluation battery. Specifically, the test was performed on the conditions of an environmental temperature of 25° C. and a voltage range of 10 mV to 2.5 V. The electric current value was determined at 3 mA/g. The results are shown in FIG. 4 .
As shown in FIG. 4 , it was confirmed that reaction potential in accordance with the Na desorption reaction appeared in the vicinity of 0.8 V (vs Na/Na + ) during desorption of Na to obtain reversible capacitance of 84 mAh/g as Na desorption capacitance. Thus, it may be confirmed that the active material having the K 4 Nb 6 O 17 phase is useful as an anode active material of a sodium ion battery. Also, this active material acts in the vicinity of 1 V (vs Na/Na + ), so as to allow safety of the battery to be improved.
Also, an evaluation battery (supporting salt: LiPF 6 =1 mol/L, solvent: EC/DMC/EMC=3/4/3) was produced in the same manner as the above by using metallic Li as a counter electrode to perform a charge and discharge test in the same manner as the above. The results are shown in FIG. 5 .
As shown in FIG. 5 , it was confirmed that reaction potential in accordance with the Li desorption reaction appeared in the vicinity of 1.5 V (vs Li/Li + ) during desorption of Li to obtain reversible capacitance of 84 mAh/g as Li desorption capacitance. Thus, it may be confirmed that the active material having the K 4 Nb 6 O 17 phase is useful as an anode active material of a lithium ion battery. Also, this active material acts in the vicinity of 1 V (vs Li/Li + ), so as to allow safety of the battery to be improved.
Example 2
The active material (K 4 Nb 6 O 17 ) obtained in Example 1 was stirred in HNO 3 aqueous solution of a concentration of 7 M at room temperature for 24 hours to ion-exchange K ion contained in the active material for H ion. Thus, an active material having a composition of H 4 Nb 6 O 17 was obtained.
Example 3
The active material (H 4 Nb 6 O 17 ) obtained in Example 2 was stirred in NaOH aqueous solution of a concentration of 1 M at room temperature for 48 hours to ion-exchange H ion contained in the active material for Na ion. Thus, an active material having a composition of Na 4 Nb 6 O 17 was obtained.
[Evaluations]
(Charge and Discharge Test)
Evaluation batteries (a sodium ion battery and a lithium ion battery) using the active materials obtained in Examples 2 and 3 were produced. A specific producing method is the same as Example 1. A charge and discharge test was performed for the obtained evaluation battery. Specifically, the test was performed on the conditions of an environmental temperature of 25° C. and a voltage range of 0.1 V to 2.5 V. The electric current value was determined at 3 mA/g. The results are shown in FIGS. 6 and 7 .
As shown in FIG. 6A , in Example 2, it was confirmed that reaction potential in accordance with the Na desorption reaction appeared in the vicinity of 0.9 V (vs Na/Na + ) during desorption of Na to obtain reversible capacitance of 110 mAh/g as Na desorption capacitance. On the other hand, as shown in FIG. 6B , in Example 2, it was confirmed that reaction potential in accordance with the Li desorption reaction appeared in the vicinity of 1.5 V (vs Li/Li + ) during desorption of Li to obtain reversible capacitance of 156 mAh/g as Li desorption capacitance. Also, it may be confirmed from the results of the charge and discharge test that the active material having the H 4 Nb 6 O 17 phase is useful as an anode active material of a lithium ion battery.
As shown in FIG. 7A , in Example 3, it was confirmed that reaction potential in accordance with the Na desorption reaction appeared in the vicinity of 0.8 V (vs Na/Na + ) during desorption of Na to obtain reversible capacitance of 113 mAh/g as Na desorption capacitance. On the other hand, as shown in FIG. 7B , in Example 3, it was confirmed that reaction potential in accordance with the Li desorption reaction appeared in the vicinity of 1.6 V (vs Li/Li + ) during desorption of Li to obtain reversible capacitance of 178 mAh/g as Li desorption capacitance. Also, it may be confirmed from the results of the charge and discharge test that the active material having the Na 4 Nb 6 O 17 phase is useful as an anode active material of a lithium ion battery.
Also, a relation between ionic radius of an A element (A=H, Na and K) and reversible capacitance of an active material obtained in Examples 1 to 3 is shown in Table 1 and FIG. 8 .
TABLE 1
A
Ionic
Reversible
Crystal
Ele-
Counter
Radius
Capacitance
Phase
ment
Electrode
(Å)
(mAh/g)
EXAMPLE 1
K 4 Nb 6 O 17
K
Na
1.38
84
EXAMPLE 2
H 4 Nb 6 O 17
H
Na
0.37
110
EXAMPLE 3
Na 4 Nb 6 O 17
Na
Na
1.02
113
EXAMPLE 1
K 4 Nb 6 O 17
K
Li
1.38
84
EXAMPLE 2
H 4 Nb 6 O 17
H
Li
0.37
156
EXAMPLE 3
Na 4 Nb 6 O 17
Na
Li
1.02
178
As shown in Table 1 and FIGS. 8A and 8B , it was confirmed that reversible capacitance increased by substituting the K element of K 4 Nb 6 O 17 of Example 1 with an H element and an Na element with smaller ionic radius. A mechanism of an increase in reversible capacitance by smaller ionic radius is probably guessed to be such that Na insertion sites and Li insertion sites in a zigzag interlayer formed by the NbO 6 octahedron increased.
Also, in Example 2, reversible capacitance increased from Example 1 whereas reversible capacitance decreased slightly as compared with Example 3. The reason therefor is guessed to be that Na ions and Li ions in Example 2 were stably inserted into sites different from Examples 1 and 3. Incidentally, a plateau was confirmed in the vicinity of 2 V in FIGS. 6A and 6B , and there is a possibility that this plateau exhibits a reaction in the sites different from Examples 1 and 3.
REFERENCE SIGNS LIST
1 . . . cathode active material layer
2 . . . anode active material layer
3 . . . electrolyte layer
4 . . . cathode current collector
5 . . . anode current collector
6 . . . battery case
10 . . . sodium ion battery or lithium ion battery | The present invention aims to provide an anode active material which may intend to improve safety of a battery. The object is attained by providing an anode active material being used for a sodium ion battery or a lithium ion battery, wherein the anode active material has an A 4 Nb 6 O 17 phase (A is at least one kind of H, Na and K). | 2 |
BACKGROUND
Currently, most motor vehicles are equipped with disk brakes, in which a metal, carbon or ceramic disk is rigidly affixed to a car wheel. To cause braking, a pair of pads, one on either side of the disk, is pressed onto the surface of the disk, causing friction and slowing the vehicle. One challenge in the design of disk brakes is the need to absorb and dissipate the great amount of heat that is generated, as the kinetic energy of the vehicle is converted to heat energy by brake friction.
In currently available disk brakes systems, the heat of braking is absorbed by the material mass between the two rubbing surfaces of each disk. This heat is dissipated, as the disk spins, through a) air convection on the two rubbing surfaces, b) air convection in ventilation passageways cast into the disk, and c) heat radiation of the two rubbing surfaces, if the surfaces become red hot. A high surface temperature reduces a brake pad's life and friction coefficient dramatically, and is therefore highly undesirable.
Another problem encountered with disk brakes is that of incomplete outer brake pad disengagement after braking. Although the inner brake pad is affirmatively withdrawn a slight distance (0.15 mm), the outer brake pad tends to gently rub against the disk, after braking. This reduces fuel efficiency.
Also, as in any automotive component, the weight of a disk brake must be carried by the vehicle, so that any reduction in weight is desirable.
SUMMARY
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
In a first separate aspect, the present invention may take the form of an automotive disk brake assembly installed in an automobile having a wheel. The assembly includes a floating caliper supporting an inner and outer brake pad and a brake rotor having a disk, and a hat, and wherein the hat is bolted to the wheel. A hydraulic cylinder is adapted to push the inner brake pads into the disk surface, thereby causing the floating caliper to move so as to bring the outer brake pad into contact with the disk surfaces. Finally, the rotor is made at least in part of a material having a thickness and a coefficient of thermal expansion and a thermal conductivity, such that a complete 100 kilometer per hour, 0.9 gross vehicle weight braking causes the disk to expand in thickness by at least 0.15 mm and to cool to shrink in thickness, relative to its expanded thickness, by at least 0.1 mm within 60 seconds of the cessation of braking, in an ambient temperature of less than 30° C.
In a second separate aspect, the present invention may take the form of a disc brake rotor that includes a mounting hat and a solid disc, rigidly affixed to the mounting hat. The solid disk has a transverse dimension core, made of a first metal and two rubbing-surface claddings, set on either transverse side of the core, the claddings made of a second metal and having a thickness of 1-10 mm, and further defining physical engagement features. Also, a third metal is interposed between the first metal and the second metal, such that the second metal is bonded with the first metal metallurgically through the third metal and mechanically by the engagement features.
In a third separate aspect, the present invention may take the form of a method of fabricating a disk for a disk brake system. The method starts by the formation of a cladding workpiece having a first major external surface defining engagement features. Then the first major external surface is coated with a second metal. A mold is provided, defining an interior shape of a rotor and the cladding workpiece is inserted into the mold. A molten third metal is into the mold so that it engages to the engagement features and reacts with the second metal and is permitted to cool, thereby forming a disk made of the third metal, which is metallurgically bonded and mechanically interlocked to the cladding workpiece.
In a fourth separate aspect, the present invention may take the form of a disk braking system having a rotor that has a conductance of greater than 2 Watts/° C.
In a fifth separate aspect, the present invention may take the form of a disk braking system having a rotor hat that has a conductance of greater than 4 Watts/° C.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments are illustrated in referenced drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.
FIG. 1 shows a cross-sectional view of a disk braking assembly having a disk attached to an automobile wheel.
FIG. 2 shows a plan view of a cladding workpiece that is incorporated into the assembly of FIG. 1 .
FIG. 2 a shows a detail view of a portion of FIG. 2 , indicated by circle 2 a.
FIG. 3 shows a plan view of three of the cladding workpieces of FIG. 2 , shown arranged as in the disk, and oriented so that the side facing into the disk is shown.
FIG. 4 shows a cross-sectional view of the rotor of the assembly of FIG. 1 .
FIG. 4 a shows a detail view of the rotor of FIG. 4 , as indicated by circle 4 a of FIG. 4 .
FIG. 5 shows a plan view of an alternative embodiment of the rotor of FIG. 4 .
FIG. 6 shows a cross-sectional view of the wheel-disk-axle junction of an alternative embodiment of the assembly of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Definition: In this application the term “inward” means toward the longitudinal center line of a vehicle in which the brake assembly is installed or into which it will be installed, and “outward” means away from this centerline.
Referring to FIGS. 1 and 4 , a brake assembly 8 , includes a brake rotor 10 , which includes a disk 11 and a mounting hat 12 , made up of a mounting hat side wall 12 ′ and a mounting hat top wall 12 ″ (see FIG. 4 ) mounted on a vehicle wheel 13 .
A floating caliper 14 , defines a hydraulic cylinder 16 into which a piston 18 is set. An inner brake pad 20 is mounted on piston 18 , such that when piston 18 is pushed outwardly from cylinder 16 , inner brake pad 20 contacts disk 11 . This in turn causes caliper 14 to be pulled inwardly so that an outer brake pad 22 , held by caliper 14 contacts disk 11 .
In currently available brake assemblies, when braking is no longer applied, the inner brake pad 20 retracts slightly, but the outer brake pad 22 does not necessarily retract adequately, and may continue to contact the rotor, causing a drag on movement and reducing fuel efficiency. In brake assembly 8 , however, rotor 10 is made in part of a metal that has a high coefficient of thermal expansion and a high thermal conductivity, so that disk 11 expands during braking. Heat is then quickly conducted away by hat 12 into wheel 13 , so that disk 11 shrinks when braking is no longer applied. As a result, outer brake pad 22 is not positioned as far inward as it would be if not for the disk 11 expansion, and when disk 11 contracts, it withdraws from contact of outer brake pad 22 , thereby avoiding the problems caused by this contact. The other alternative in addressing the problem of the outer pad 22 not retracting sufficiently after braking would be to enlarge the spread of the caliper 14 , thereby spreading the pads 20 and 22 apart. This, however, worsens the brake pedal response, forcing the driver to press the brake pedal down farther before braking begins. The slightly slower braking response would add to the number of automobile accidents occurring every year.
Many aluminum alloys have the thermal properties required to effectuate the present invention. These are a high coefficient of thermal expansion and high thermal conductivity (such as A308, A355, A356, A357, A443, A514, A850, and pure aluminum). Unfortunately, however, aluminum alloys are typically too soft to use in a brake rotor. In a preferred embodiment this problem is addressed by providing a steel cladding 30 affirmatively attached to a second metal disk core 32 . The rotor 10 is connected to a wheel 13 made of a material with high thermal conductivity and high specific heat such as an aluminum alloy. In order to maximize the flow of heat through and out of rotor 10 , it is solid (as opposed to vented) and the thickness of the mounting hat side wall 12 ′ is greater than 0.024 of disk 11 diameter, preferably much greater if the brake assembly space allows, the mounting hat height should be lower, preferably less than 5 cm for a front disk brake, or less than 8 times of the thickness of the mounting hat side wall, the mounting hat outer diameter is greater than 0.5 of disk 11 outer diameter, and the diameter of the contact area 5 between the mounting hat 12 and the wheel 13 is preferably equal to the mounting hat outer diameter. If not, a thermal coupler can be designed, fabricated and installed to increase the contact area, therefore, the heat transfer from the mounting hat to the wheel. A thermal conductive paste can be applied between the mounting hat and the wheel contact to further improve heat transfer.
Equation (1) describes the theoretical temperature increase in ° C., of a front disk brake (which generates the bulk of the heat in an automobile, relative to the rear brakes).
T th = ( 1 - ϕ ) 2 [ w ( v 1 2 - v 2 2 ) 2 g ( ρ r c r v r + ρ c c c v c ) ] ( 1 )
Where T th =theoretical temperature increase, ° C.
φ=the percentage rear braking W=vehicle weight, kg V 1 =initial velocity, m/s V 2 =final velocity, m/s g=gravitational constant, 9.8 m/s 2 ρ r =rotor body material density, kg/m 3 c r =rotor body material specific heat capacity, J/kg° C. ν r =rotor body material volume, m 3 ρ c =clad material density, kg/m 3 c c =clad material specific heat capacity, J/kg° C. ν c =clad material volume, m 3
In addition, we can define the following two quantities, the conductance of the rotor (Conductance rotor ) and the conductance of the hat (Conductance hat ), using the parameters defined for the.
Conductance
rotor
=
k
r
A
cross
H
hat
+
Th
1
/
2
d
+
D
d
-
h
One braking system design goal is to limit the theoretical temperature increase to less than 230° C. after a complete stop from 100 kph. The use of a brake body material with high specific heat and a solid disk brake help to meet this goal. Aluminum and its alloys are good candidate materials for this application.
The calculation for heat dissipation from a traditional vented disk brake is based on the sum of convective cooling of rubbing surfaces, convective cooling of ventilation surfaces, and radiative cooling of rubbing surfaces. The disk brake disclosed in this application is of a solid type, and has the same convective cooling and radiative cooling of rubbing surfaces, but replaces the convective cooling of ventilation surfaces (Eq. 2) with conductive cooling to a connected metal wheel (Eq. 3).
q vent =h vent A vent ( T r −T ∞ ) (2)
Where q vent =heat dissipation by convection at ventilation surfaces, Joules/hour
h vent =heat transfer coefficient of convection at ventilation surfaces, Joules/(hour*m 2 *° C.) A vent =ventilation surface area, m 2 T r =rotor body temperature, ° C. T ∞ =ambient temperature, ° C. h=hours
q cond =k r A cross ( T r −T wh-C )/( H hat +Th 1/2d +D d-h ) (3)
Where q cond =heat dissipation by conduction to metal wheel, J/h
k r =rotor body thermal conductivity, J/(h m° C.) A cross =cross section area of rotor mounting hat side wall, m 2 T r =rotor body temperature, ° C. T wh-C =wheel temperature at the contact surface with rotor, ° C. H hat =height of rotor mounting hat, m (reference number 36 is FIG. 4 ) Th 1/2d =half thickness of rotor disk, m D d-h =the distance between the disk middle circle and the mounting hat middle circle ( FIG. 4 .), m (reference number 34 in FIG. 2 .)
In addition, we can define the following two quantities, the conductance of the rotor (Conductance rotor ) and the conductance of the hat (Conductance hat ), using the parameters defined for the heat dissipation equation, above:
Conductance
rotor
=
k
r
A
cross
H
hat
+
Th
1
/
2
d
+
D
d
-
h
Watts
/
°
C
.
(
4
)
Conductance
hat
=
k
r
A
cross
H
hat
Watts
/
°
C
.
(
5
)
In a preferred embodiment, a disk braking system has a rotor that has a conductance of greater than 4 W/° C. when used for stopping a movement with a maximum (270 kJ) kinetic energy loaded on the brake system. For stopping a movement with higher kinetic energy, the conductance should be increased proportionally.
Also, in a preferred embodiment, a disk braking system has a rotor hat that has a conductance of greater than 8 W/° C. when used for conducting a maximum heat converted from 270 kJ kinetic energy at once from the rotor disk to a contacted wheel. For conducting a greater heat flow, the conductance should be increased proportionally.
EXAMPLE
A 2002 Dodge Neon passenger car has 1,542 kg or 15,129 Newton GVWR, 70% braking on front brakes, 85% heat distribution onto rotor, 15% onto pads, 8% tire slip. The car decelerates from a speed of 128.7 km/h or 35.76 m/s without brake lockup. The entire vehicle braking energy is
E
b
=
(
15
,
129
)
(
35.76
)
2
2
(
9.81
)
=
986
,
067
Nm
=
0.274
kWH
The converted braking heat absorbed by one front brake is
E b-fr =(0.274)(1−0.08)(0.70)(0.5)(0.85)=0.075 kWh=270 kJ
The Dodge Neon disc brake has an aluminum body with k r =166 W/(m° C.), a mounting hat with wall cross section 29.35 cm 2 , hat height 3.81 cm, disc thickness 2.03 cm, and D d-h 1.78 cm. Its rotor conductance and hat conductance are 0.00639 kW/° C. and 0.0128 kW/° C. respectively.
The heat stored in the connected wheel is then dissipated by convective cooling of outer wheel surfaces.
q wh =h wh A wh ( T wh-A −T ∞ ) (6)
Where q wh =heat dissipation by convection of wheel surfaces, Joules/hour
h wh =heat transfer coefficient of convection at wheel outer surfaces, Joules/(hour*m 2 *° C.) A wh =wheel outer surface area, m 2 T wh-A =average wheel temperature, ° C.
Proper design of disk brake and wheel shapes and dimensions and proper selection of materials can make the conductive cooling of the present invention, q cond and q wh , much greater than q vent , for a traditional vented disk brake. This results in the wheel acting as the main heat sink and radiator, and lower brake working temperatures, up to several hundred degrees lower than temperatures reached at identical braking conditions by conventional cast iron disk brakes. Lower working temperatures reduce the pad wear considerably. All passenger cars, except for very small ones, use vented disk brakes for their front brake applications because they can take heavier duty. Unfortunately, the vents of the vented disk brakes of cast iron rust readily and get air blocked quickly, causing their heat dissipation capabilities to decline dramatically after a moderate period of use. The preferred embodiment described above makes nonferrous metal based and solid (not vented) disk brake suitable for front brake applications of most passenger cars. This preferred embodiment of disk brake does not rely on vents, which have proven so problematic, for heat dissipation and does not rust readily, resulting in consistent and excellent capability of heat dissipation during its entire life. The invented disk brake is also suitable for rear brake applications. The parking brake shoes, which contact the rear brakes on the interior surface of the hat side wall, can be made of softer material, as they are contacting an aluminum alloy, which is softer than the cast iron that similar pads contact in currently available rear disk brakes.
In one preferred embodiment, the disk brake and wheel assembly can absorb and dissipate heat during repeated 100 kph (kilometer per hour) 0.9 GVWR (deceleration of gross vehicle weight rating with 0.9 gravitational constant) braking without exceeding 480° C. GVWR is the weight that a vehicle is designed to carry. The GVWR includes the net weight of the vehicle, the weight of passengers, fuel, cargo, and additional accessories.
EXAMPLE
A brake rotor's performance is evaluated quantitatively using a brake dynamometer. It can simulate precisely the brake working conditions and obtain the brake's response as in a real vehicle, such as GVWR, vehicle weight center, wheel rolling radius, static and dynamic wheel loads, wheel inertia, vehicle speed, deceleration speed, stop distance, pressure on brake pad, friction coefficient, and rubbing surface temperatures of inboard pad, outboard pad and rotor before and after a stop. Brake fade test is a standard test procedure to evaluate the temperature performance of a brake rotor and pads by 15 continuous stops at GVWR, 120 kph speed, 0.3 g deceleration, and 45 second stop intervals.
A SCA solid brake rotor for the 2002 Dodge Neon front brake used with an aluminum wheel mounted together has been tested on a brake dynamometer by a commercial brake testing lab following the FMVSS-135 certification test procedure. The fade test included in the FMVSS-135 certification test shows that the final temperature of the rotor rubbing surface is 365° C. and 150° C. lower than the final pad temperature immediately after the 15th stop. In contrary, the final rotor temperature of the corresponding cast iron vented rotor is 569° C. and 144° C. higher than the final pad temperature with the identical testing conditions. It shows that the SCA brake rotor surface temperature is 204° C. cooler than the corresponding cast iron brake rotor surface temperature under identical fade test conditions. The corresponding cast iron brake rotor means identical outer dimensions in comparison with the SCA brake rotor.
Fabrication
Referring to FIG. 2 , FIG. 2 a and FIG. 4 a , in a preferred embodiment, rotor 10 is manufactured by producing three steel cladding work pieces 30 ′, each in the shape of a 118° arc, and forming a set of through cuts 34 and step cuts 15 .
A binder, preferably organic, such as rosin, gum, glue, oil, dextrin, acrylic, cellulose, syrup, phenolic, or polyurethane, is applied to a portion of said preliminary cladding work piece 30 ′ evenly or in a predetermined pattern. As an alternative embodiment, the binder is blended with additives. These additives may consist of metal, metal oxide and/or carbon particles in the size range from 0.1-500 μm, preferably 1-147 μm, in the binder and additive weight ratio preferably 1:2 to 1:10.
Metal beads 40 ( FIG. 3 ), which may be of either regular or irregular shapes, adhere on the binder-applied surface 41 of the preliminary cladding work piece 30 ′ ( FIG. 2 ). The regular or irregular shapes may include spherical, cylindrical, polyhedral, ellipsoidal, T-shape, I-shape, L-shape, V-shape, screw, cone, staple, and other shapes which can generate mechanical interlocking. Equal-size metal spheres of 2-20 mm in diameter or 3.14-314 mm 2 in cross-section are used in one preferred embodiment. These metal beads 40 adhere on the binder-bearing surface 41 in a predetermined distribution pattern in conjunction with the said slot 34 ( FIG. 2 ) pattern to arrange the slots 34 ( FIG. 2 ) between beads to reduce thermal stress between beads during fabrication and service.
Alternatively, binder may be applied to the beads 40 , rather than, or in addition to, the cladding workpiece 30 ′. The distance between beads is preferably 1.5-10 times of said bead's diameter.
The workpiece 30 ′, now including the binder and the beads 40 , is loaded into a furnace. At an elevated temperature, the metal oxide reduces by carbon if metal oxide powder is used, the binder and possibly a portion of the beads 40 and the surface material of cladding workpiece 30 ′, form a transient metal liquid. The transient metal liquid forms necks 42 ( FIG. 4 a ) on the beads 40 . Due to atomic diffusion of elements in the metal necks to adjacent regions, the metal necks become solid at said elevated temperature. The cross-sectional diameter of a metal neck 42 is smaller than the bead's diameter, preferably ⅓-⅔ of the bead's diameter. After cooling, the beads 40 are welded onto the preliminary cladding workpiece 30 ′ through the metal necks 42 . As an alternative embodiment, the binder itself forms metal liquid and builds metal necks at an elevated temperature. The metal necks become solid after cooling.
The cladding workpiece can be further shaped by bending, straightening, punching, drawing or welding. The metal beads 40 can be deformed by pressing to form them into shapes better adapted for mechanical interlocking. The workpiece 30 , is coated with a second metal which can form metallurgical bonding or interface compounds with both steel and a third metal. The second metal can be selected from Cu, Zn, Ni, Cr, Al, Fe, Si, Mn, Mg, Ti and their alloys. The workpiece is coated partially or entirely by chemical vapor deposition, physical vapor deposition, thermal spray coating, plating, spraying, brushing, or dipping.
The cladding workpiece is then inserted into a sand or metal mold. The third metal 32 ( FIG. 1 ), preferably an aluminum alloy, is melted and cast into this mold to form a solid disk brake with the cladding workpiece 30 ′. Any metal casting methods commonly used by the metal casting industry, such as green sand casting, die casting, squeeze casting, permanent mold casting, coremaking and inserting, investment casting, lost foam casting, and others, can be used in this invention. During casting, the molten third metal 32 is poured into the mold so that it flows about and covers the beads and reacts with the second metal and permits the molten third metal 32 to cool. The first metal surface, including the surface of the beads 40 and the necks 42 , the cladding workpiece 30 ′, and the step cut 15 surface bonds with the third metal body 32 in the combination of metallurgical bonding and mechanical interlocking, such as the third metal catches both the necks 42 of beads 40 and the step cuts 15 . The resulting disk brake is heat-treated to release residual stress, machined to produce the final product with the required dimensions and enhanced properties on the rubbing surfaces, and painted with a high temperature paint in part to prevent salt corrosion.
Referring to FIG. 5 , in an alternative preferred embodiment, wider cladding slots 50 are cut to allow molten third metal 32 ( FIGS. 1, 4 a , and 4 ) into the slots 50 during casting. After machining, the rubbing surfaces present a steel and aluminum hybrid structure as shown in FIG. 5 . If carbon-kevlar pads are used such, the friction coefficient can be further increased to shorten stop distance.
Referring to FIG. 6 , in a preferred embodiment, the inwardly facing surface of hat top wall 12 ″ is thermally and sonically separated from the bearing hub 60 by a thin gasket 62 , preferably made of poly tetrafluoroethylene. Gasket 62 also prevents the rotor 10 from sticking to the bearing hub 60 by way of a rust buildup. As another alternative to using a gasket 62 , poly tetrafluoroethylene can be coated on the hat top wall 12 ″ inwardly facing surface.
While a number of exemplary aspects and embodiments have been discussed above, those possessed of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. | An automotive disk brake assembly installed in an automobile having a wheel. The assembly includes a floating caliper supporting an inner and outer brake pad and a brake rotor having a disk, and a hat, and wherein the hat is bolted to the wheel. A hydraulic cylinder is adapted to push the inner brake pads into the disk surface, causing the floating caliper to move bringing the outer brake pad into contact with the disk. Finally, the rotor is made such that a complete 100 kilometer per hour, 0.9 gross vehicle weight braking causes the disk to expand in thickness by at least 0.15 mm and to cool to shrink in thickness, relative to its expanded thickness, by at least 0.1 mm within 60 seconds of the cessation of braking, in an ambient temperature of less than 30° C. | 5 |
The present application is based on and claims priority of Japanese patent application No. 2009-290042 filed on Dec. 22, 2009, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control system of a galley installed in an aircraft.
2. Description of the Related Art
Conventionally, there are various galley-mounted equipments (hereinafter referred to as “insert equipments”) disposed in a kitchen facility (hereinafter referred to as “galley”) on an aircraft. The respective insert equipments have their own dedicated control panels, and the equipment is usually manipulated through the control panels. Therefore, it was not possible to provide control commands integrally for controlling the multiple insert equipments, or to monitor the insert equipments collectively. Therefore, a control system for correctly controlling these insert equipments in a short time in a prompt manner is desired.
However, in order to realize such a control system, it is necessary to constitute a certain communication system within the aircraft so as to enable frequent exchange of information between the respective insert equipments and the controller (display/control panel). Since the existing control system installed in the aircraft is subjected to complex and bothersome aviation communication restrictions, it was not easy to constitute a communication system between the insert equipments and the controller.
Therefore, a local communication network is to be constructed in order to establish an information and telecommunication with which the controller monitors and operates the insert equipment. It is expected that such galley control system is to be constructed into aircraft.
A proposal to adopt a Controller-area network (CAN bus) as a communication means for a galley control system of an aircraft has been deliberated in ARINC (ARINC project paper 812; Definition of Standard Data Interfaces for Galley Insert (GAIN); Equipment; CAN Communications), but it has not yet been officially announced. In the proposal of ARINC specification 812, a galley data bus network is constructed between insert equipments and a master galley control unit (MGCU) as master via a CAN bus interface for performing mutual communication and exchanging information, and necessary information is communicated with the aircraft system by connecting to the communication network of the aircraft via the MGCU. Special attention is given to the point that a peak of the total consumption power at meal time during which all the insert equipments are used at the same time can be reduced and dispersed by adjusting the start time of operation of the insert equipments through the network, which is considered to be an indispensible method for reducing the capacity of the generator disposed on the aircraft and saving energy.
There is another proposal related to utilizing the network of the galley data bus as a local network for controlling the insert equipments within the galley. Such art can be realized by additionally providing a CAN bus interface to the insert equipments, arrange a CAN bus wiring within the main body of the galley and disposing a MGCU additionally.
On the other hand, along with the diversification of lighting devices, much attention is recently given to an illumination light communication system that does not use the CAN bus interface. Japanese patent application laid-open publication No. 2008-271317 (patent document 1) discloses an example of an illumination light communication system enabling a large amount of data to be transmitted at high speed. According to the disclosed illumination light communication system, a transmitter emits modulated light that is modulated in accordance with data to be transmitted from an organic electroluminescence (EL) light source (commonly known as “OLED”: organic light-emitting diode). A receiver receives the modulated light emitted from the OLED, converts the received light into an electric signal and demodulates data from the converted electric signal. Since the system adopts an organic EL element formed of a material having a high speed response performance as the illumination light source of the illumination light communication system, the system can increase the amount of data transmission per unit time compared to a white light-emitting diode (LED), for example, and can transmit a large amount of data at high speed.
Further, Japanese patent application laid-open publication No. 2003-115803 (patent document 2) proposes a light emitting device and a communication system including the same, in which the communication speed is accelerated in a communication using light. According to the communication system, the light emitting device is provided with a light emitting element capable of transmitting signal light composed of light modulated on the basis of input data, the light emitting element being an EL element. Further, the light emitting element emits non-signal light composed of non-modulated light and signal light in different periods, wherein the non-signal light also functions as illumination. Further, the signal light also functions as illumination. Moreover, a means for storing transmitted information is connected to a light receiving element, for storing and writing in transmitted information.
Further, Japanese patent application laid-open publication No. 2008-227944 (patent document 3) proposes a receiver for visible light communication which does not require supply of power, and a visible light communication system using the same. Data transmission equipment modulates the driving current of lighting element (LED) with the received data, and changes the level of the light of LED according to the driving current. The data receiver detects the received illumination light from a change of output of a solar cell panel, demodulates this detected signal, and displays the demodulated data on a display section.
On the other hand, a communication system using infrared light is widely used in private households. Recently, much attention is given to visible light communication using visible light, along with the widespread use of illumination equipments using elements having good optical response such as LED and OLED. Visible Light Communications Consortium (VLCC) and Infrared Data Association (IrDA) have published on Mar. 6, 2009 a “visible light communication standard” version 1.0 compatible with the IrDA communication system.
In order to realize a control system for controlling insert equipments used within the galley, it is necessary to construct some type of control system as proposed in ARINC specification 812 and to enable frequent data exchange between the respective insert equipments and the controller (display/control panel) disposed on the aircraft. However, the controller disposed on the aircraft already has a constructed network for performing control operation of the aircraft, and in order to communicate with this network and exchange information with the aircraft, it is necessary to design a system satisfying the aviation communication regulations and having a high reliability. However, such control system integrated with the aircraft system could not be realized easily at a low cost.
On the other hand, a system having given up the communication with the aircraft system and constructed as a network using a CAN bus as a local communication system, such as the one proposed in ARINC specification 812 for enabling communication between the insert equipments within the galley and a controller, a failure caused by wire connection may occur. The respective electronic equipments including the network environment within the galley must satisfy a series of regulations regarding a sequence of typical environment testing conditions determined to comply with aviation regulations, such as an RICA/DO•160 standard specification determined by the special committee of the Radio Technical Commission for Aeronautics. Especially in section 21.0 of RICA/DO 160, there is a standard specification regarding radio frequency (RF) energy emission which restricts radiated RF emission and conducted RF emission of electromagnetic noises leaking from electronic equipments, and at present, much work and costs are required to comply with this regulation. The CAN bus interface is not an exception and the regulations related to the standard specification of radio frequency energy emission cannot be avoided easily.
As described, there are various problems to be solved in designing a simple and inexpensive network system, and such system has not yet been realized. We consider that the construction of a wireless communication network that does not use any wired electric signal communication is most appropriate as a galley control system. Optical communication using no wires is considered to function sufficiently within the narrow galley space. In order to perform mutual communication between the insert equipments and the controller, it is necessary to realize a mutual direction communication using two kinds of lights. For example, a visible light and an infrared light can be used.
SUMMARY OF THE INVENTION
This invention describes the method of composing the galley control system by constructing the optical communication network where a radiated RF emission and conduction RF emission that becomes a problem in the wired network are not generated, and using this in the galley for the aircraft.
The purpose of this invention offers the control system by the optical communication network to the galley for the aircraft, and makes each insert equipment function more efficiently and more certainly.
In order to solve the above-mentioned problems, the present invention provides a galley control system of an aircraft comprising an insert equipment having a visible light receiving element and an infrared (hereinafter referred to as “IR”) emitting element and disposed in the galley of an aircraft, and a galley controller for controlling the insert equipment disposed in the galley or in a circumference thereof and having a visible light emitting panel, an IR receiving element and a display/control panel, wherein the galley control system is equipped with a mutual communication function between the galley controller and the insert equipment and a remote control function for controlling the insert equipment from the galley controller via transmission of visible light communication data from the visible light emitting panel of the galley controller to the visible light receiving element of the insert equipments and via transmission of IR communication data from the IR emitting element of the insert equipment to the IR receiving element of the galley controller.
According to the above-described galley control system of an aircraft, the insert equipments disposed in the galley of an aircraft and the galley controller disposed within the galley or in the circumference area thereof can either mutually communicate via visible light and IR light and, as a result, be designed so that the galley controller can remote control the insert equipments in a wireless manner.
According further to the galley control system of an aircraft, the visible light emitting panel of the galley controller has both the function to emit light for transmitting visible light communication data to the insert equipment and a function to emit light for illuminating the interior of the galley. The visible light emitting panel can have both a visible light communication function and an illuminating function for illuminating the galley, so that the use of such equipment having multiple functions contributes to reducing the number of components, reducing weight, and saving the space within the aircraft.
According to the galley control system of an aircraft, the visible light receiving sensor and the IR emitting element of the insert equipment is disposed on a front panel thereof, and the visible light emitting panel and the IR receiving element of the galley controller is either disposed to face the front panel of respective insert equipments or on a ceiling or at a high position close to the ceiling within the galley or in a circumference area thereof. By disposing the visible light emitting panel and the IR receiving element of the galley controller at a position facing the front panel of the respective insert equipments, communication is enabled by minimizing the possibility of visible light and IR light for communication being blocked between the galley controller and the respective insert equipments. Furthermore, by disposing the visible light emitting panel and the IR receiving element of the galley controller at an appropriate position on or near the ceiling of the galley or in the circumference area thereof, communication is enabled by minimizing the possibility of visible light and IR light for communication being blocked between the insert equipments and the galley controller, by emitting light from the ceiling or near the ceiling above the respective insert equipments and by emitting light toward the ceiling or near the ceiling.
In the present galley control system of an aircraft, a deflection angle conversion element for changing a deflection angle of visible light and IR light entering or exiting the insert equipment is disposed on an upper surface of the visible light receiving sensor and the IR emitting element of the insert equipment. By attaching light deflection elements on the visible light receiving and visible light emitting elements disposed on the front panel of the insert equipments and using the same, it becomes possible to solve the problem of orientation of the lights when visible light and IR light are used as means for communication, that is, the communication accuracy can be improved by aligning the deflection angles thereof.
According to the galley control system of an aircraft of the present invention, upon executing the remote control function, the insert equipment receives information for enabling the remote control function from the galley controller and transmits a own operating status information related to the remote control function to the galley controller within a given period of time. And according to this aspect of the present invention, information related to executing the remote control function from the galley controller to the insert equipments can be communicated between the galley controller and the insert equipments.
According to the present galley control system of an aircraft, a control switch for performing operation setup and manipulation of the remote control function of the insert equipment is provided on the display/control panel of the galley controller.
According further to the present galley control system of an aircraft, the galley controller is equipped with a memory for storing information transmitted from the insert equipment, and the galley controller displays necessary information included in the received information on the display/control panel to enable operation statuses of respective insert equipments to be monitored collectively. Moreover, the galley controller can output an alarm or a warning to the circumference if necessary based on the monitored operation statuses of the insert equipments.
According to the present galley control system of an aircraft, a back light of the display/control panel can be used instead of the visible light emitting panel of the galley controller for transmitting the visible light communication data.
Construction of a network using wires within the galley of an aircraft requires much time and costs to comply with the restrictions of aviation regulations and the cost-related effect is deteriorated thereby, while the galley control system of an aircraft according to the present invention having the above-described aspects constructs a wireless optical communication network using visible light and IR light, according to which a network free from restrictions of aviation regulations can be constructed. Therefore, the cost-related effect can be improved by suppressing the costs related to constructing the communication network.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an image showing an optical communication between a galley of an aircraft and a control system to which a galley control system of an aircraft according to the present invention is applied;
FIG. 2 is an image showing the data communication between a controller (master) and an insert equipment (slave) in the galley control system of an aircraft shown in FIG. 1 ;
FIG. 3 is a block diagram showing the galley control system of an aircraft illustrated in FIG. 1 ;
FIG. 4 is an image showing the installation of the insert equipments and the galley controller according to the galley control system of an aircraft illustrated in FIG. 3 ;
FIG. 5 is an image showing a display/control panel of a controller according to the galley control system of an aircraft of the present invention; and
FIG. 6 is an image showing a deflection angle conversion element of a front panel of an insert equipment according to the galley control system of an aircraft of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the preferred embodiments of a galley control system of an aircraft according to the present invention will be described with reference to the drawings.
FIG. 1 shows in perspective view an example of an outline of a galley of an aircraft to which the galley control system according to the present invention is applied. A galley of an aircraft is a kitchen facility disposed within an aircraft, having a large number of insert equipments (galley hardware) such as ovens, microwaves, coffee brewers, freezers and refrigerators for storing cooled or frozen food, heating food, or making coffee, tea and other beverages. There are no insert equipments illustrated in the galley in FIG. 1 , but in general, ovens, microwave ovens, coffee brewers and other cooking equipments are disposed on the upper shelf, and freezers, refrigerators and other storage equipments are disposed on the lower shelf.
The galley of an aircraft has a very compact size so as not to take up much space in a passenger aircraft. On the other hand, cabin attendants on board the aircraft are constantly entering and exiting the galley to respond to the needs of passengers or to provide service to the passengers, and various operations such as inserting, cooking, and removing food and drinks from various insert equipments are performed frequently in the galley. Therefore, it is bothersome to respectively manipulate the various insert equipments by entering the galley, and the complication within the galley of the aircraft can be solved if the insert equipments can be controlled collectively via a galley controller.
As shown in FIG. 1 illustrating the image of a visible light and IR light optical communication of the galley control system, a display/control panel 3 of a galley controller 2 is disposed at a given position within a galley 1 of an aircraft. The galley controller 2 controls a plurality of insert equipments (preferably all the equipments disposed in the galley) through manipulation of the display/control panel 3 , which enables to control the operation of insert equipments through mutual communication or via remote control. Visible light communication is a communication means making use of the blind spot that the human eyes cannot sense the change of visible light luminosity in short periods (approximately 1 ms or shorter).
A visible light emitting panel 4 or an IR receiving element 5 disposed in the galley controller 2 for controlling transmission and reception of communication with insert equipments are disposed within or near the galley 1 of an aircraft at a high position such as on a ceiling or near the ceiling. Since transmission and reception of visible light and IR light for communication with various insert equipments disposed within the galley 1 of an aircraft is performed from such a high position, it becomes possible to prevent transmission and reception errors caused by visible light and IR light being blocked for a long period of time by cabin attendants entering and exiting the galley 1 of the aircraft.
FIG. 2 is a chart showing the order of data transmission between a controller (master) and insert equipments (slave) in a galley control system of an aircraft according to the present invention. It shows that when the data transfer quantity of data communication is 7 bits, the frame length is 60 bites, the number of slaves is eight, and the data communication speed is 9600 bps, the time required for a single communication cycle in which the communication between the master and eight slaves takes a round is 0.8 seconds. After communication from the master to a specific slave is performed, the slave sends a response to the master, and such transmission and reception of data is performed sequentially for all the respective slaves. Upon executing the remote control function, the insert equipments receive information related to enabling the remote control function from the galley controller 2 , and transmits a own operating status information related to the remote control function to the galley controller 2 within a given period of time.
FIG. 3 is a view showing one example of a system block of the galley control system of an aircraft according to the present invention. The galley controller 2 comprises a display/control panel 3 , a visible light emitting panel 4 , an IR receiving element 5 and a CPU 11 , wherein the CPU 11 is connected to an input/output interface 12 connected to a key matrix 13 and receiving input of input data 14 and outputting output data 15 , a ROM 16 , a display/control panel data processor 17 for controlling the display/control panel 3 , a RAM 18 as memory, a transfer data processor 19 for controlling a driver 21 for driving the visible light emitting panel 4 by receiving supply of power from a power supply 20 , and a data processor 22 for processing data received via the IR receiving element 5 .
On the other hand, the insert equipment 6 is equipped with a visible light receiving sensor 7 which is a visible light receiving element for receiving visible light communication data 9 sent from a visible light emitting panel 4 disposed on the galley controller 2 , and an IR emitting element 8 for transmitting IR light communication data 10 to the IR receiving element 5 disposed on the galley controller. A visible light sensor such as an amorphous silicon can be used as the visible light receiving sensor 7 for receiving the visible light subjected to luminosity modulation via communication data, according to which the communication data contained in the visible light can be identified. At this time, the identification of communication data is affected if other visible light sources exist in the surrounding area, so extra attention is required. The insert equipment 6 further includes a CPU 31 for controlling the overall equipment, wherein the CPU 31 is connected to an input/output interface 32 connected to the visible light receiving sensor 7 and the IR emitting element 8 , a ROM 33 , a display data processor 34 for controlling the display panel 35 , and a RAM 36 .
The IR light communication data transmitted from the IR emitting element 8 of each insert equipment 6 must not interfere with the visible light spectrum (380 nm to 780 nm in normal wavelength) emitted as transmission light from the visible light emitting panel 4 on the galley controller 2 . In other words, special care is required since the IR receiving element 5 may have a region that responds to visible light (the generally used wavelength region is a short wavelength region from 750 nm to 1000 nm, which overlaps with the visible light region). In order to correctly perform the identification of various insert equipments 6 , an ID indicating which position within the galley 1 of the aircraft the insert equipment 6 is disposed is provided, and the insert equipment 6 corresponding to the ID is associated when performing communication. For example, an installation position information corresponding to an ID code is provided to a vacant pin of a connector through which the insert equipment 6 receives power supply from the galley 1 of the aircraft, and the slave (insert equipment 6 ) having received a call from the master (galley controller 2 ) via the ID code starts communication. When a response from a slave cannot be recognized during start up of the system, that specific ID is skipped thereafter during operation.
FIG. 4 is an image showing how the insert equipments and the galley controller are disposed according to the galley control system of an aircraft according to the present invention. A plurality of insert equipments 6 a , 6 b and 6 c are disposed in the galley 1 of an aircraft, wherein the insert equipments 6 a through 6 c include visible light receiving sensors 7 and IR emitting elements 8 disposed on front panels thereof.
On the other hand, a common galley controller 2 for performing control of the insert equipments 6 a through 6 c is disposed in the galley 1 of an aircraft. The galley controller 2 has a visible light emitting panel 4 for transmitting visible light communication data to the insert equipments 6 a through 6 c , and an infrared receiving element 5 for transmitting infrared communication data from the insert equipments 6 a through 6 c , wherein the visible light emitting panel 4 and the infrared receiving element 5 are either disposed to face the front panels of the insert equipments 6 a through 6 c or disposed on a ceiling or a high position near the ceiling or near the galley 1 of an aircraft, as illustrated. Therefore, nothing will interrupt the visible light and IR light between the front panels of the insert equipments 6 a through 6 c and the visible light emitting panel 4 and the IR receiving element 5 at any given point of time, and therefore, visible light and IR light communication can substantially be ensured. The visible light emitting panel 4 is considered to use elements such as organic ELs and LEDs having a good response, which is disposed on the ceiling of the galley, so that the panel 4 can also have a visible light emitting function for illuminating the interior of the galley 1 of an aircraft.
The galley controller 2 is equipped with a display/control panel 3 connected via wires with the visible light emitting panel 4 and the IR receiving element 5 . The height and position of the display/control panel 3 is determined so as to enable cabin attendants to easily view and manipulate the panel. Since elements such as organic EL and LED having a good response is also used as the backlight of the display/control panel 3 , the panel 3 can be used instead of the visible light emitting panel 4 of the galley controller 2 for illuminating and for transmitting visible light communication data, by supplying signals of a driver 21 to the visible light emitting element of the display/control panel 3 and providing a panel surface luminance of approximately 1000 cd/m 2 .
FIG. 5 is an image showing one example of a display/control panel of a galley controller. The display/control panel 3 includes a display 40 displaying the operation statuses of specific equipments such as the mode, time and temperature etc. corresponding to the respective insert equipments (nine equipments denoted by numbers 00 through 08 according to the illustrated example) disposed in the galley 1 of an aircraft. The galley controller 2 has a memory for storing information transmitted from the insert equipments, wherein the galley controller 2 displays necessary information out of the received information on the display/control panel 3 , so as to collectively monitor the operation statuses of the insert equipments 6 . The galley controller 2 can further output an alarm or a warning if necessary to the surrounding area based on the monitored operation statuses of the insert equipments 6 . The display/control panel 3 has a row of manipulation switches 41 including a select switch, an up/down switch, an enter switch, a cancel switch and a page switch, and through these switches, the operator can set and manipulate the operation during execution of a remote control function of the insert equipments 6 .
FIG. 6 is an image illustrating the state in which a deflection element is disposed on a front panel of an insert equipment. On an upper side of a front panel having the visible light receiving sensor 7 and the IR emitting element 8 of the insert equipment 6 is disposed a deflection angle conversion element 50 composed of a prism or a mirror for changing the deflection angle of the entering or exiting visible light and IR light. The directions of the visible light and the IR light entering or exiting the visible light receiving sensor 7 and the IR emitting element 8 can be changed from the horizontal direction to the perpendicular upper direction (or from the perpendicular upper direction to the horizontal direction) by using the deflection angle conversion element 50 to deflect the directions of the visible light and the IR light by 90 degrees as shown in the drawing, so that the visible light emitting panel 4 and the IR receiving element 5 of the galley controller 2 can be disposed directly above the insert equipments 6 .
The deflection angle conversion element 50 has a function to monitor the amount of received light of the visible light receiving sensor 7 via a display on the front panel of the insert equipment 6 and to adjust the angle so that the amount of received light becomes maximum, in order to perform visible light and IR light communication at a more precise position. According to one example of such mechanism, the mounting angle of the deflection angle conversion element 50 with respect to the insert equipment 6 can be varied along a long hole (long circular hole) and the deflection angle conversion element 50 can be fixed within the long hole at a position where the amount of received light becomes maximum. | A control system is provided that adopts a communication network using wireless visible light and IR light communications in a galley of an aircraft which is subjected to limitations of aviation regulations regarding wired communications. Insert equipments each having a visible light receiving element and an IR emitting element are disposed in a galley of an aircraft, and a galley controller is disposed within the galley or a circumference area thereof having a visible light emitting panel, an IR receiving element and a display/control panel for controlling the insert equipments. A mutual communication function between the galley controller and the insert equipments and a remote control function for controlling the insert equipments from the galley controller are realized via transmission and reception of visible light communication data and IR communication data. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to the field of steam cooking appliances or implements, and concerns more particularly multifunction steam cookers provided for cooking on a perforated support as well as in a vessel.
A steam cooking appliance or implement has a base provided for the production of steam that is to be supplied to a cooking enclosure. Steam cooking appliances also have heating means, for example of the electric type, while cooking implements do not have a separate heating means.
Appliances and implements are provided with a cooking enclosure that generally includes a lower receptacle atop which one or several cooking vessels, or supports, and a lid, are provided. The lower receptacle is used to collect cooking liquids and condensates. However, the cooking enclosure can have an external wall that is independent of the vessels and/or the cooking supports, and/or the collecting receptacle.
Slow cooking or simmering is effectuated at a temperature below 100° C., but can last for several hours. Steam can thus be utilized to perform this cooking. A cooking vessel adapted to such slow cooking has a lateral wall and a bottom that are not provided with openings. A lid closing the cooking vessel enables the food products to be protected from the vapor. Heat is transmitted to the food products via the walls.
Steam cooking of dry food products, such as rice, is carried out in water and utilizes a cooking vessel having a bottom that is not provided with openings and a lateral wall whose lower part is also not provided with openings. It is preferable to not use a lid to close the cooking vessel. In effect, the absence of a lid permits the steam to be in contact with the food products or the liquid in order to accelerate the cooking. Liquid foods such as sauces and soups can equally be cooked or reheated in this manner.
Steam cooking of other food products is generally performed on perforated supports through which steam passes.
U.S. Pat. No. 4,509,412 discloses a steam cooker having a cooking vessel provided with a curved bottom having openings at the periphery of the bottom. The openings are arranged above a receptacle for recovering cooking liquids. This arrangement avoids disturbing water in the reservoir arranged at a central position in the base of the appliance.
The patent document WO 88/07829 discloses a steam cooker having a cooking enclosure with a lid that is provided with an internal peripheral groove communicating with a pouring tube opening above the water reservoir. This arrangement permits condensates to be collected.
It has been noted that none of these appliances allows the recycling of condensates to be reconciled with the separate collection of cooking juices in a simple manner.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a steam cooker that does permit the recycling of condensates to be reconciled with the separate collection of cooking juices in a simple way. Thus, the invention provides a steam cooker of the type described above, in which the utilization of cooking juices is facilitated.
To achieve these and other objects, the invention provides a steam cooker having a water reservoir supplying or constituting a steam production chamber, and a cooking enclosure supplied with steam from the steam production chamber, having an intermediate collecting receptacle provided with a means for pouring liquid into the water reservoir, in which can be arranged a cooking vessel and/or support provided with a means permitting liquid to flow into the intermediate collecting receptacle. According to the invention, pouring means is associated with a removable blocking, or closing, means.
References herein to a cooking vessel are intended to encompass a vessel having an imperforate bottom and sidewalls that are imperforate to a sufficient height to avoid overflow or escape of the food products. Steam can reach the food products if no lid is provide on the vessel. However, cooking juices will remain within the vessel. The vessel can be closed by a lid for a slow cooking of the simmering type, at a temperature below 100° C.
A support having a flow means refers to a support having lower and/or side openings, and/or lateral cutouts provided for flow of cooking liquids. Steam can thus pass through the support, through the openings or cutouts, and pass around the food products.
The removable closing means permits the user to employ the intermediate collecting receptacle either to allow condensates to flow into the water reservoir, or as a recovery basin, or bowl, for the cooking juices.
When the food products are placed in a cooking vessel, the cooking juices remain confined in the cooking vessel. Steam coming into contact with the interior walls of the cooking enclosure or with the outer walls of the cooking vessel form condensates that can flow along those walls to be collected in the intermediate collecting receptacle. The condensates not coming back into contact with the food products contained in the cooking vessel, then, constitute a water reserve that can be reused for cooking without risk of polluting the steam production chamber. In order to recycle the condensates toward the water reservoir, the user opens the pouring means of the intermediate receptacle by withdrawing, or removing, the closing means. This arrangement eliminates the need for the user to add water during a cooking operation, or at least reduces the frequency at which water must be added.
When the food products are placed on the cooking support, the user puts the closing means in place to block the pouring means of the intermediate collecting receptacle. This arrangement prevents the cooking juices coming from the food products placed in the cooking support from disturbing, or mixing with, the water in the reservoir. The user can then easily gain access to the cooking juices collected in the intermediate collecting receptacle.
An appliance or implement according to the invention is thus versatile and efficient.
Advantageously, the closing means is fixed to the intermediate collecting receptacle. This arrangement helps to prevent the closing means from being lost. Alternatively, the closing means can be independent or even fixed to another element of the steam cooker.
According to one embodiment, the closing means is composed of a valve having a closing surface connected to a shank engaged in the pouring means, the shank being pivotably supported by a lever along an off-center pivot axis. The lever has a bearing surface whose distance from the pivot axis increases between a first zone, in which the closing surface is moved to a position that opens the pouring means, and a second zone, in which the bearing surface is in contact with a surface of the intermediate collecting receptacle in order to maintain the closing surface against an opposed face of the receptacle. Thus, the position of the lever permits a control of the closing or opening of the pouring means by the valve.
Advantageously, then, the pouring means is an orifice arranged in a wall of the intermediate collecting receptacle, the closing surface being a ring and the shank extending from the interior of the ring. The orifice can then be provided in the bottom of the intermediate collecting receptacle.
Advantageously, also, the pivot axis between the shank and the lever is form by two aligned tenons, or pins, engaged axially in two cavities each having a lateral cutout permitting a force-fitted insertion of the tenons. This arrangement facilitates assembly of the device.
Advantageously then, the lever has a pair of cheeks, or side pieces, each carrying one of the tenons on its interior face, the bearing surface being arranged on the periphery of the side pieces. Such a part can easily be produced by molding. Also advantageously, the side pieces are connected by a tongue. Such a lever can be easily maneuvered by the user.
Also advantageously, the lever is arranged on an interior surface of the intermediate collecting receptacle. In other words, when the intermediate collecting receptacle is in place on the water reservoir, the user can gain access to the lever without having to withdraw the receptacle.
Also advantageously, the closing surface is formed by a joint, or seal, mounted on a flange fixed to the shank. Alternatively, the joint can be mounted on the intermediate collecting receptacle.
According to another embodiment, the closing means is formed by a supple plug, or stopper.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an elevational, cross-sectional view of an electric steam cooker according to the invention having a first example, or embodiment, of the means for closing the pouring means of the intermediate collecting receptacle.
FIGS. 2 and 3 are perspective views of the two components of a second example of construction of the means for closing the pouring means of the intermediate collecting receptacle.
FIGS. 4 and 5 are front elevational views of the second example showing, respectively, the open position and the closed position.
FIGS. 6 and 7 are side elevational views of the second example showing, respectively, the open position and the closed position.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an electric steam cooking appliance according to the first embodiment having a base 1 , provided for the production of steam, the base being provided with a water reservoir 2 and a heating element 3 associated with an electronic control device 9 permitting operation of the appliance at full power during an initial phase of heating and operation at reduced power during the cooking phase. The reduced power can be furnished in the form of a continuous current or current pulses separated by intervals during which the electric power supply is disconnected. An annular wall 4 is arranged around heating element 3 . Wall 4 is provided with a lower passage 5 separating reservoir 2 from a steam production chamber 6 .
On top of base 1 there is provided a cooking enclosure 10 having a bottom 11 , lateral walls 12 , 13 and 14 , and a lid 15 . Lid 15 has a concave lower face 16 , a gripping element 17 and a vent 18 .
An intermediate collecting receptacle 20 arranged on base 1 forms the bottom 11 of cooking enclosure 10 . Receptacle 20 has a peripheral wall 21 supporting lateral wall 12 . Wall 21 surrounds a basin, or bowl, 22 provided to collect cooking juices or condensates. An annular wall 23 extends upwardly form the bottom of basin 22 . Wall 23 has orifices 24 near its top provided for the passage of steam coming from chamber 6 . Receptacle 20 has a pouring means 25 associated with a removable closing means 26 . Pouring means 25 is formed by an orifice formed in the bottom of basin 22 .
According to the form of construction shown in FIG. 1, closing means 26 is formed by a supple, or flexible, plug, or stopper, 27 connected to receptacle 20 by an attachment piece 28 . Plug 27 is made, for example, of an elastomer.
A cooking support 30 is mounted on an internal rim, or flange, of wall 12 . Cooking support 30 is formed by a removable plate 31 provided with perforations 32 , the perforations forming a means 33 that permit liquid to flow into receptacle 20 disposed under plate 31 .
A cooking vessel 40 has an imperforate bottom 41 and a lateral wall 42 that is imperforate up to the top of an upper rim 43 . Openings 44 are provided in a wall 45 that forms a part of vessel 40 and connects vessel 40 to lateral wall 14 of enclosure 10 . Openings 44 permit steam to reach the interior surface 16 of lid 15 , where the steam condenses. Because of the concave form of lower surface 16 , the condensates flow along that surface in order to form a liquid seal by condensation at the level of rim 43 , due to the small distance provided between rim 43 and surface 16 . Steam coming from stream production chamber 6 then continues to heat bottom 41 and lateral wall 42 of cooking vessel 40 , without penetrating to the interior of the vessel.
When the user wishes to cook food products on support 30 , cooking juices can flow through perforations 32 in plate 31 . The user must insert plug 27 into pouring means 25 to block pouring means 25 if the user wants the cooking juices to be collected in receptacle 20 . The user can easily gain access to the cooking juices collected in receptacle 20 by withdrawing the other elements of cooking enclosure 10 .
When the user wants to cook food products in vessel 40 , condensates can form on the wall of the cooking enclosure outside of vessel 40 and flow back into collecting receptacle 20 . In order to prolong unattended operation of the appliance, the user can withdraw plug 27 . The condensates collected in receptacle 20 can then flow back into reservoir 2 and can again supply water to steam production chamber 6 .
Recycling of the condensates can equally be envisioned during cooking in a vessel placed on support 30 . In effect, cooking juices remain confined in that vessel.
A second embodiment is illustrated in FIGS. 2-7, in which closing means 26 ′ is formed by a valve 50 pivotably connected to a lever 60 along an off-center pivot axis 61 .
Valve 50 has a closing surface 51 connected to a shank 52 pivoted with respect to lever 60 . Closing surface 51 is an annulus and shank 52 emerges from the portion of valve 50 that is enclosed by this annulus. Closing surface 51 is formed by a joint, or seal, 57 mounted on a flange 58 fixed to shank 52 . Shank 52 is engaged in an orifice forming pouring means 25 arranged in the bottom of receptacle 20 . Two cavities 53 and 54 forming part of the pivot mechanism are formed in shank 52 .
Lever 60 is composed of a pair of cheeks, or side pieces, 67 , 68 connected together by a tongue 69 . The inner face of each of cheeks 67 , 68 carries a respective tenon, or pin, 65 , 66 . The two pins 65 , 66 , are aligned with one another. The axes of pins 65 , 66 form the pivot axis 61 . Lever 60 is arranged on an inner face 29 of receptacle 20 . Lever 60 has bearing surfaces 62 . The distance between each bearing surface 62 and axis 61 increases between a first bearing zone 63 and a second bearing zone 64 .
Each bearing surface 62 is extended, at one side and the other of bearing zones 63 and 64 , on the one hand by a first rest zone 70 and on other hand by a second rest zone 71 . As shown in FIG. 3, rest zones 70 and 71 are formed by two preferably opposed faces of the periphery of each of side pieces 67 and 68 . On each of the side pieces, the first rest zone 70 is connected to the second rest zone 71 by a circular sector on which bearing zones 63 and 64 are arranged.
The pivot axis, or articulation, between shank 52 and lever 60 is formed by the two tenons, or pins, 65 and 66 concentric with axis 61 and engaging in cavities 54 and 53 , respectively. Each of cavities 54 and 53 has a lateral cutout 55 or 56 permitting insertion of tenons 65 and 66 , possibly with a force fit.
As shown in FIGS. 4 and 6, when first rest zone 70 is in contact with the inner face 29 of receptacle 20 , bearing zone 63 is situated in proximity to face 29 . Bearing zone 63 being relatively close to axis 61 , shank 52 articulated in axis 61 is in a lower position with respect to pouring means 25 . Blocking surface 51 is spaced from the opposite, or outer bottom, surface of receptacle 20 and opens pouring means 25 . Lever 60 then occupies the position that is desired during slow cooking, or simmering. The recycling of condensates enhances the capability to perform a cooking operation unattended.
As shown in FIGS. 5 and 7, when second rest zone 71 is in contact with inner face 29 of receptacle 20 , bearing zone 64 is situated in proximity to inner face 29 . Bearing zone 64 being relatively distant from axis 61 , shank 52 is brought into its upper position with respect to pouring means 25 . Blocking surface 51 is maintained against the opposite surface, or outer bottom surface, of receptacle 20 . Pouring means 25 is thus blocked. Lever 60 then occupies the position desired during steam cooking, allowing cooking juices to be collected in receptacle 20 .
The present invention thus provides a versatile steam cooker that is easy to use, allowing several types of steam cooking to be performed.
In order to pass from one position to the other of valve 50 , the user simply maneuvers lever 60 by acting on tongue 69 . Supporting contact between lever 60 and receptacle 20 is transferred from rest zone 70 to rest zone 71 while passing through bearing zones 63 and 64 , and vice versa.
According to one alternative feature of the first embodiment, plug 27 can be made of rigid material, and a joint, or seal, can then be provided on plug 27 or in receptacle 20 . Attachment piece 28 is not essential.
According to one alternative form of construction for the second exemplary embodiment, lever 60 can be mounted on the lower surface, or outer bottom surface, of receptacle 20 . A spring would then be used to push shank 52 back in order to open pouring means 25 . Tenons 65 and 66 can be mounted on shank 52 and cavities 53 and 54 can then be provided in lever 60 . Joint 57 can be disposed around orifice 25 .
According to a further alternative, pouring means 25 is not necessarily formed in the bottom of receptacle 20 , but can alternatively be formed in a lateral wall of receptacle 20 , adjacent its bottom.
According to yet another alternative, cooking receptacle 40 can be associated with a lid that is independent of the lid of cooking enclosure 10 , or need not have a lid.
This application relates to subject matter disclosed in French Application Number 01 14345, filed Nov. 6, 2001, the disclosure of which is incorporated herein by reference.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.
Thus the expressions “means to . . . ” and “means for . . . ”, or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation. | A steam cooker composed of: a water reservoir for water that is to be converted into steam by a steam generator; a cooking enclosure for receiving a cooking vessel and/or a support provided with flow passages, the cooking enclosure being arranged to be supplied with steam from the steam generator; an intermediate collecting receptacle associated with the cooking enclosure and disposed for collecting liquid that appears in the cooking enclosure during a cooking operation, the intermediate collecting receptacle having a pouring orifice via which liquid can flow from the intermediate collecting receptacle into the water reservoir; and a removable closing member associated with the pouring orifice for selectively blocking flow of liquid via the pouring orifice. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to poly[alkylene-4,4'-(ethylenedioxy)bis benzoate] copolymers as well as surgical devices formed therefrom. More particularly, this invention relates to flexible monofilament surgical sutures having unique handling and knot-tying characteristics.
Many natural and synthetic materials are presently used as surgical sutures. These materials may be used as single filament strands, i.e. monofilament sutures, or as multifilament strands in a braided, twisted or other multifilament construction. Natural materials such as silk, cotton, linen, and the like, do not lend themselves to the fabrication of monofilament sutures and are accordingly used mostly in one of the multifilament constructions.
Certain synthetic materials which are extruded in continuous lengths can be used in monofilament form. Common synthetic monofilament sutures include polypropylene, polyethylene and nylon 6. Such monofilament sutures are preferred by surgeons for many surgical applications due to their inherent smoothness and noncapillarity to body fluids.
Available synthetic monofilament sutures all suffer to a greater or lesser degree from one particular disadvantage, that is relative stiffness. Besides making the material more difficult to handle and use, suture stiffness or low compliance can adversely affect knot-tying ability and knot security. It is because of the inherent stiffness of available monofilament sutures that many suture materials are braided or have other multifilament constructions with better handling, flexibility and conformity.
Most monofilament sutures of the prior art are also characterized by a high degree of stiffness. This makes knot-tying difficult and reduces knot security. In addition, the low compliance and limited ductility prevent the suture from "giving" as a newly sutured wound swells, with the result that the suture may place the wound tissue under greater tension than is desirable, and may even cause some tearing, cutting or necrosis of the tissue.
The problems associated with the use of low compliance sutures in certain applications were recognized in U.S. Pat. No. 3,454,011, where it was proposed to fabricate a surgical suture composed of Spandex polyurethane. Such sutures, however, were too elastic and did not find general acceptance in the medical profession.
Recently issued U.S. Pat. No. 4,224,946 describes a monofilament suture with good flexibility and knot strength, which suture is composed of segmented polyetheresters which contain (1) a polymeric block of polyalkylene ethers and (2) a polymeric block of aromatic dicarboxylic acids or cycloaliphatic acids with short chain aliphatic or cycloaliphatic diols. Similar subject matter is disclosed in Belgian Pat. No. 880,486.
The ethylene glycol polyester of the subject diacid moiety, 4,4'-(ethylenedioxy)bis benzoic acid, has been known for some time, (C.A. Registry No. [24980-45-8] if prepared from the acid, [26373-72-8] if prepared from the dimethyl ester) and, in fact, its ethylene glycol/polytetramethylene oxide copolymers (C.A. Registry Nos. [9071-04-9] and [51884-53-8] have been prepared:
CA 76 114610y
CA 80 83814u mentioned in index only
CA 81 171028s
CA 81 P12175g
CA 83 P195002w manufacture of elastic fiber
CA 84 P75556d polyester composite fibers with rubber-like elasticity)
as well as copolymers based on polyethylene oxide. These polyesters have been described as possessing improved crimpability, dyeability, and moisture absorption properties.
The 1,4-butanediol polyester of the subject diacid moiety is disclosed in Chemical Abstracts [52826-06-9]. In a 1978 paper (C.A. 89 60077c) which relates to the transesterification of dimethyl esters of aromatic dicarboxy acids with α-hydro-ω-hydroxy poly(oxyethylene)s and α,ω-alkanediols, a polytetramethylene oxide/1,4-butanediol copolymer based on the subject diacid moiety was made.
In spite of the fact that several polyethers could be incorporated chemically to toughen and lower the modulus of related polyesters, it is generally accepted that linear thermoplastics possessing a high initial modulus are more difficult to modify to increase compliance. Fibers of the (all hard) homopolymers of the subject invention were found to possess moduli in excess of 1.5 million psi, which renders it unsuitable for producing monofilament sutures. Patents that relate to (2-alkenyl or alkyl)succinates are U.S. Pat. No. 3,542,737 and U.S. Pat. No. 3,890,279. None of these patents discloses the present copolymers or modifications thereof.
Theory and experience in the art of fiber chemistry predict that branching (such as that present in the instant copolymers) may inhibit fiber formation and will exert a deleterious effect on the tensile properties of any resulting fibers due to the inability of the unoriented branch to contribute to the load bearing capacity of the fiber; and by the stearic interference posed by the branch to chain alignment during fiber orientation. It is therefore surprising that strong fibers, in particular strong, flexible compliant fibers may be formed from the present copolymers with pendant hydrocarbon chains. As will be seen from Table 1, Example (i), homopolymers prepared from the 1,4-butanediol polyester of the subject diacid moiety, have a modulus of 1,678,000 psi. It is surprising that the modulus of certain of the copolymers of the present invention is reduced to only 64,000 psi.
It is an object of the present invention to provide a novel copolymer of poly(alkylene-4,4'-(ethylenedioxy)bis benzoate) as well as surgical devices formed therefrom. It is a further object of the present invention to provide a novel flexible, thermoplastic monofilament suture or ligature of said copolymer, having a diameter of from about 0.1 to 50 mil and possessing unique and desirable physical properties. Yet a further object of the present invention is to provide a Cobalt 60 sterilizable monofilament with lower modulus, better hand and more desirable tie-down characteristics than those of monofilaments of polypropylene. It is a further object of this invention to provide a monofilament suture with a desirable degree of ductility to accommodate changing wound conditions. It is yet another object of this invention to provide a monofilament suture with the flexibility and knot-tying characteristics of a braided suture. These and other objects will be made apparent from the ensuing description and claims.
SUMMARY OF THE INVENTION
The present invention relates to a copolymer comprising a multiplicity of recurring A and B units having the following general formula: ##STR1## wherein x and y are numbers having average values such that the B units comprise from 1 to 55 weight percent of the copolymer, and the A units comprise the remainder,
n is 2 to 8, and
R represents a linear or branched alkyl or alkenyl radical with a chain length of 4 to 30 carbon atoms, or a mixture of such radicals with different chain lengths.
In accordance with an embodiment of the invention, n is 4 and R has a chain length of 14-18 carbon atoms, the copolymer having an inherent viscosity of between 0.5 and 2.2 and a melting temperature of between 100° and 200° C. Preferably B comprises from 20-40 weight percent of the copolymer. A preferred copolymer composition has an inherent viscosity of between 0.8 and 1.5, and a melting temperature of between 135° and 170° C.
The most preferred embodiments of this invention include those copolymers in which R is a hexadec-2-enyl group CH 2 CH═CH--(CH 2 ) 12 CH 3 , and the A and B units are present on about a 72/28 mole basis; and R being a mixture of tetradec-2-enyl and octadec-2-enyl groups, the latter two R groups being present in about a 50/50 ratio (molar), the A and B units being present on about a 72/28 mole basis.
The invention also comprises surgical devices (especially sutures and clips) formed from the copolymer.
A size 3/0 strand of a filament of the present invention, has the following combination of mechanical properties:
Knot strength--at least 20,000 psi
Tensile strength--at least 30,000 psi
Young's modulus--less than about 600,000 psi
Elongation--from about 20% to 80%
Monofilament sutures of the present invention (having a size 3/0 strand) are preferably characterized by the following combination of mechanical properties:
Knot strength--30,000 to 65,000 psi
Tensile strength--45,000 to 100,000 psi (more preferably 60,000 to 100,000 psi)
Young's modulus--75,000 to 600,000 psi (more preferably 75,000 to 250,000 psi)
Elongation--from 20% to 55%
Sutures possessing the above characteristics may be prepared by melt extrusion, forming a continuous filamentry strand, and drawing the extruded filament to obtain the desired suture properties.
Monofilament sutures having physical properties in accordance with the present invention are particularly useful in many surgical procedures where the suture is used to close a wound which may be subject to later swelling or change in position. The combination of low Young's modulus and moderate to high elongation provides the suture with an appreciable degree of ductility and high compliance under low applied force. As a result, the suture is able to "give" to accommodate swelling in the wound area. In addition, the ductility and high tensile strength of the suture allow the suture to stretch during knot tie-down so that the knot "snugs down" for improved tying ability and knot security with a more predictable and consistent knot geometry regardless of variations in suture tying technique or tension.
Within the scope of the present invention is a filament as described above having a surgical needle attached to at least one end and useful as a surgical suture. Also within the scope of the present invention is such a filament or surgical suture in a sterile condition, and in addition such filament or sterile suture, packaged in a sterile enclosure. Also within the scope of the present invention is a method of closing a wound by approximating and securing the wound tissue with a filament or surgical suture of the present invention.
As may be seen from the attached Table 1, the copolymers of the present invention may be melt extruded into filaments suitable for use as synthetic sutures which are compliant and yet strong. Table 1 compares the properties of fibers formed from the present copolymer with those formed from other polymers. Specifically, Example (i) is the homopolymer of the 1,4-butanediol polyester of the subject diacid moiety. The remaining copolymers listed in Table 1 are, in each case, copolymers of the 1,4-butanediol polyester of the subject diacid moiety, with different types of non-crystallizable chain sequences (a) (known as soft-segments) which are listed at the bottom of Table 1. It will be noted that the homopolymer of Example (i) gives rise to fibers possessing moduli in excess of 1.5 million psi. Copolymers based in part on dimer acids (4G-D) according to Example (iv) as well as copolymers based in part on polyether [Examples (ii) and (iii)] give rise to values between about 250,000 and 500,000 psi even though the weight percent of the "soft" non-crystallizable portion ranges from 20% to 30%. Indeed even a polymer made to contain 30 weight percent of tetramethylene-2-octadecenyl succinate (Example IX) gives rise to fibers exhibiting a 350,000 psi Young's modulus. Polymers of Examples I, II and X provide unexpected results. The copolymer of Example I which contains 30 weight percent tetramethylene-2-hexadecenyl succinate moieties and the copolymer of Example II in which the "soft" segment is based on a mixture of tetramethylene-2-tetradecenyl succinate and tetramethylene-2-octadecenyl succinate give rise to compliant yet relatively strong fibers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The copolymers of the present invention are prepared by the polycondensation of a 4,4'-(ethylenedioxy)bis benzoate (preferably the dimethyl ester); a diol (preferably 1,4-butanediol); and a (2-alkenyl or alkyl) succinic anhydride. A (2-alkenyl or alkyl) succinic acid or a suitable derivative, such as a dialkyl ester [for example, dimethyl(2-alkenyl or alkyl)succinate], may be substituted for the anhydride and, in addition, a mixture of more than one(2-alkenyl or alkyl) succinic anhydride may be used. The diacid, 4,4'-(ethylenedioxy)bis benzoic acid, may be used instead of the corresponding ester. ##STR2##
The diacid 4,4'-(ethylenedioxy)bis benzoic acid is prepared by reaction of 1,2-dihaloethane and p-hydroxybenzoic acid in the presence of a suitable base, the reaction being followed by acidification to produce the free acid (which, after purification, can be used in a direct polymerization). The dimethyl ester is prepared by Fisher esterification and purified by recrystallization from ethyl acetate. Alternatively, the diester can be prepared directly by the reaction of a 1,2-dihaloethane with methyl p-hydroxy benzoate, prepared in a nonaqueous medium in the presence of a suitable base. The dimethyl ester is used to prepare by polycondensation techniques the polyesters listed in Table 1.
The required diols are commercially available. The substituted succinic anhydrides can be prepared by the "ene" reaction of maleic anhydride and an olefin (preferably a terminal olefin): ##STR3## wherein R' is alkyl.
In the instance wherein R is alkyl, rather than alkenyl, the reactant may be prepared by hydrogenation of the corresponding alkenyl-succinic anhydride.
The polymerization may be run in the absence or, preferably, in the presence of stabilizers such as hindered phenols, {e.g., Irganox 1098 sold by Ciba-Geigy [N,N'-hexamethylene bis(3,5-ditertbutyl-4-hydroxy hydrocinnamide)]} or secondary aromatic amines, {e.g., Naugard 445 sold by Uniroyal [4,4'-bis(α,α-dimethylbenzyl)diphenylamine]}. Acetates, oxides and alkoxides of numerous polyvalent metals may be employed as the catalyst such as, for example, zinc acetate, or magnesium acetate in combination with antimony oxide, or zinc acetate together with antimony acetate. However, the preferred catalyst for the polymerization is a mixture of about 0.04 to 0.1% (based on total charge weight) tetrabutyl orthotitanate and about 0.004 to 0.006% magnesium acetate. If a dyed product is desired, a compatible dye such as, for instance, D&C Green No. 6, can be added to the polymer or monomer mixture in concentrations of up to 0.5% based on expected polymer yield.
The polymerization is run in two stages. In the first stage, run under nitrogen at temperatures ranging from about 160° to 250° C., polycondensation via transesterification and esterification occurs, resulting in lower molecular weight polymers and oligomers. These are converted to higher molecular weight materials in the subsequent step run at about 220° to 255° C., at pressures of less than 1 mm of mercury. The resulting polymers, exhibit inherent viscosities (measured at a 0.1 g/dl concentration in hexafluoroisopropyl alcohol at 25° C.) of 0.5 to 2.2, and crystallinity of about from 20% to 50%. The Tm of the polymers (by microscopy), depending on composition, varies from about 90° to 230° C.
A summary of polymer properties is set forth in Table 1.
The polymers are readily extruded in a ram-type extruder, as for an example an Instron Capillary Rheometer at about 10° to 70° C. above the resin Tm, depending on the polymer's molecular weight. The resulting extrudates can be drawn and the total draw ratio may vary from 3X to 7X.
The unique oriented fibers exhibit an unexpected combination of properties. For example, strands of about 6 to 8 mil diameter displayed knot strenghts of 23,000-37,000 psi, straight tensile strengths of 50,000-69,000 psi and a Young's modulus of less than 350,000 psi. Percent elongations range from 23% to 37%.
In summary, the polymers described lend themselves to ready extrusion and drawing to strong and supple fibers which are useful as high compliance "ultra limp" sutures. The fibers are Cobalt 60 sterilizable without significant change in properties (in contrast to polypropylene fibers) and retain their strength in aqueous biological environment (in contrast to nylon 6 fibers).
The present polymers may also be used to prepare solid products (molded or machined) such as clips.
GENERAL POLYMERIZATION PROCEDURE
The desired amounts of dimethyl 4,4'-(ethylenedioxy)bis benzoate, a 2-alkenyl succinic anhydride (or an alkyl succinic anhydride), a 1.3 to 2.0 molar excess of an alkylene diol per mole of diacid moieties (benzoate plus anhydride) and a given stabilizer are placed under nitrogen into a dry reactor fitted with an efficient mechanical stirrer, a gas inlet tube and a takeoff head for distillation. The system is heated under nitrogen to 160° C. and stirring is begun. To the stirred reaction mixture the required amount of catalyst is added. (Alternatively, the catalyst may be added along with the other reagents at the start, if they are dry). The mixture is then stirred and heated under nitrogen for given time periods at 190° C. (2 to 4 hours) and 220° C. (1 to 3 hours). The temperature is subsequently raised to 230° to 255° C. and over a period of 0.4 to 0.7 hours, the pressure is reduced in the system to about 1 mm/Hg (preferably 0.05 mm to 0.1 mm). (Alternatively, after reaction under nitrogen, the mixture may be allowed to cool to room temperature, vacuum applied at a later date and the batch heated to the reaction temperature). Stirring and heating under the above conditions is continued to complete the polymerization. The endpoint is determined by either (a) estimating visually the attainment of maximum melt viscosity, (b) measuring inherent viscosity or melt indices of samples removed from the reaction vessel at intermediate time periods, or (c) using a calibrated torquemeter (attached to the stirrer of the reactor).
At the end of the polymerization cycle the molten polymer is extruded and pelletized (or slow cooled in the glass reactor, isolated and ground in a mill). The polymer is dried at 80° to 110° C. for 8 to 16 hours under reduced pressure. One alternate method of polymerization is set forth in U.S. Pat. No. 3,890,279.
GENERAL EXTRUSION PROCEDURE
Extrusion using the Instrom Capillary Rheometer produces an extrudate which upon drawing (3× to 7× ratio) yields fibers in the 7 to 13 ml diameter range. The polymers are packed in the extrusion chamber and extruded through a 40 mil die after a dwell time of 9 to 13 minutes at the extrusion temperature. The ram speed is 2 cm/minute. While extrusion temperatures depend both on the polymer Tm and on the melt viscosity of the material at a given temperature, extrusion at temperatures of 10° to 70° C. above the Tm is usually satisfactory. The extrudate is taken up at a speed of about 18 to 24 feet per minute.
GENERAL DRAWING PROCEDURE
The extrudate (diameter range, 19-23 mils) is passed through rollers at an input speed of four feet per minute and then over a hot shoe or into a heated draw bath of glycerine. The temperatures of the hot shoe or draw bath vary from about 50° C. to 120° C. The draw ratio in this first stage of stretching varies from 3× to 6×. The drawn fibers are then placed over another set of rollers into a glycerine bath (second stage) kept at temperatures ranging from 60° C. to 100° C. Draw ratios of up to 2× are applied but usually only a slight amount of fiber extension (1.25×) is found desirable at this stage. Finally, the fiber is passed through a water wash, dried and taken up on a spool.
The copolymers of the present invention may be spun as multifilament yarn and woven or knitted to form sponges or gauze, (or nonwoven sheets may be prepared) or used in conjunction with other compressive structures as prosthetic devices within the body of a human or animal where it is desirable that the structure have high tensile strength and desirable levels of compliance and/or ductility. Useful embodiments include tubes, including branched tubes, for artery, vein or intestinal repair, nerve splicing, tendon splicing, sheets for tying up and supporting damaged kidney, liver and other abdominal organs, protecting damaged surface abrasions, particularly major abrasions, or areas where the skin and underlying tissues are damaged or surgically removed.
In more detail, the surgical and medical uses of the filaments of the present invention include, but are not necessarily limited to:
Knitted products, woven, or nonwoven including velours
a. burn dressings
b. hernia patches
c. medicated dressings
d. fascial substitutes
e. gauze, fabric, sheet, felt or sponge for liver hemostasis
f. gauze bandages
In combination with other components
a. arterial graft or substitutes
b. bandages for skin surfaces
c. burn dressings (in combination with polymeric films)
Solid products, molded or machined
a. orthopedic pins, clamps, screws and plates
b. clips
c. staples
d. hooks, buttons, and snaps
e. bone substitutes (e.g., mandible prosthesis)
f. needles
g. intrauterine devices
h. draining or testing tubes or capillaries
i. surgical instruments
j. vascular implants or supports
k. vertebal discs
l. Extracorporeal tubing for kidney and heart-lung machines
m. artificial skin and others.
TABLE 1__________________________________________________________________________Physical Properties of Fibers of Poly[tetramethylene-4,4'-(ethylenedioxy)bis benzoate] and itsCorresponding Polyether, Dimerate and Alkenyl Succinate Copolymers Example No. (i) (ii) (iii) (iv) I II VIII IX X__________________________________________________________________________Type of non-crystallizable None (b) PTMO-- PTMO-- 4G-- 4G-- 4G-- 4G 4G 4Gchain segment (a) EDBB EDBB D S.sub.16 S.sub.14 /S.sub.18 S.sub.18 S.sub.18 S.sub.18Wt. % of non-crystallizable 0.00 20 30 25 30 14 25 30 40chain segment 16Mole % of non-crystallizable 0.00 7 11 16 28 14 22 27 36chain segment 14Polymer Inherent Viscosity, 1.40 1.70 1.13 0.99 1.06 0.88 0.78 0.66 0.72dl/g (HFIP, 25° C., 0.1 g/dl)Polymer Tm (by 198 180 173 166 150 150 158 163 150microscopy), °C.Extrusion Temperature, °C. 260 240 200 250 200 200 240 175 185Drawing ConditionsOne Stage "Hot-Shoe": Ratio 5X 5X -- -- -- -- -- -- --Temp., °C. 101 101 -- -- -- -- -- -- --Multi-Stage Glycerin Draw Bath:1st Stage: Ratio -- -- 5X 5X 5X 5X 5X 7X 5XTemp., °C. -- -- 53 55 55 52 55 58 502nd Stage: Ratio -- -- 1.2X 1.3 1.2X 1.2 1.3X -- 1.2XTemp., °C. -- -- 70 70 70 70 75 -- 75Overall Draw Ratio 5X 5X 6X 6.5X 6X 6X 6.5X 7X 6XPhysical Properties of FibersDiameter, mil 9.5 9.3 8.9 7.5 7.7 7.9 6.6 6.5 8.1Straight Tensile Strength, 59 65 51 71 65 65 69 53 50psi × 10.sup.-3Knot Tensile Strength, 48 39 31 30 31 35 37 28 23psi × 10.sup.-3Elongation, % 27 45 42 24 31 36 26 23 37Modulus, psi × 10.sup.-3 1678 471 283 356 166 140 314 350 64__________________________________________________________________________ (a) PTMO--EDBB = polytetramethylene oxide4,4(ethylenedioxy)bis 4G--D = tetramethylene dimerate (from oleic acid dimerization) 4G--S.sub.16 = tetramethylene2-hexadecenylsuccinate (i.e. n = 4 and R = 2hexadecenyl) 4G--S.sub.14 = tetramethylene2-tetradecenylsuccinate (i.e. n = 4 and R = 2tetradecenyl) 4G--S.sub.18 = tetramethylene2-octadecenylsuccinate (i.e. n = 4 and R = 2octadecenyl) (b) The 1,4butanediol based homopolymer, poly[tetramethylene4,4(ethylenedioxy)bis benzoate]
The following are specific examples for producing new copolymers in accordance with the present invention.
EXAMPLE I
To a flame dried mechanically stirred, 100 ml two-neck glass reactor, suitable for polycondensation, is charged 19.60 g of dimethyl 4,4'-(ethylenedioxy) bis benzoate (59.34 mmoles), 7.41 g of 2-hexadecenylsuccinic anhydride (23.0 mmoles), 14.83 g of 1,4-butanediol (164.6 mmoles), and 0.1510 g Erganox 1098 (0.5% of expected weight of formed polymer).
After purging the reactor and venting with nitrogen, the reactor is immersed in a silicone oil bath and connected to a gas supply to maintain nitrogen at 1 atmosphere of pressure. The stirred mixture is heated to 160° C.; the side neck is unstoppered and under a flush of nitrogen, 0.16 ml of an alcoholic tetrabutyl orthotitanate/magnesium acetate solution is carefully injected. (Preparation of catalyst solution: to 0.5000 g of anhydrous magnesium acetate is added 16.5 ml of methanol and 33 ml of a tetrabutyl titanate in n-butyl alcohol solution, previously prepared by mixing 12.3 ml of tetrabutyl titanate in 100 ml of n-butyl alcohol). After restoppering, the stirred mixture is heated to and maintained at 190°, 200°, and 220° C. for 1, 2, and 3 hours respectively, during which time the distillate is collected. The reactor is allowed to cool to room temperature. Some time later, the reactor is evacuated and heated to 150° C. to melt the reaction mass. Over the course of one hour, the temperature is slowly raised to 240° C. which is maintained for 6 hours. The collection of distillates is continued during the low pressure (less than 100 microns) stage of the polymerization. The reactor is removed from the oil bath and allowed to cool. The formed polymer is isolated, ground and then dried at 80° C. for 8 hours in vacuo. The polymer has an inherent viscosity of 1.06 dl/g as determined in hexafluoroisopropanol at 25° C. and a concentration of 0.1 g/dl.
EXAMPLES II TO X
A polymerization is carried out as described in Example I except that the reactor is charged with the ingredients listed in Table 2. The temperature at which the polymers melt is dependent on the composition so that in the transition from reaction under nitrogen to reaction under vacuum, a higher or lower temperature may have to be employed to melt the cooled reaction mass.
Table 3 lists the types of A and B units present in the copolymers obtained according to each of Examples I through X, as well as the weight and mole percent of each unit present in each copolymer.
TABLE 2__________________________________________________________________________Amount of DimethylExample4,4'-(ethylenedioxy) Anhydride DiolNo. bis benzoate (g) Type Amount (g) Type Amount (g)__________________________________________________________________________I 19.60 2-hexadecenylsuccinic 7.41 1,4-butanediol 14.83II 19.60 2-tetradecenylsuccinic 3.38 1,4-butanediol 14.83 2-octadecenylsuccinic 4.03III 19.60 2-butenylsuccinic 6.17 1,4-butanediol 17.91IV 19.60 2-triacontenylsuccinic 7.96 1,4-butanediol 13.46V 26.60 2-decenylsuccinic 1.16 1,4-butanediol 15.39VI 14.00 2-hexadecenylsuccinic 12.34 1,4-butanediol 14.54VII 21.28 2-hexadecenylsuccinic 7.97 ethylene glycol 11.06VIII 21.00 2-octadecenylsuccinic 6.26 1,4-butanediol 14.68IX 19.60 2-octadecenylsuccinic 7.52 1,4-butanediol 14.56X 16.80 2-octadecenylsuccinic 10.02 1,4-butanediol 14.32__________________________________________________________________________ In addition to the diester, the anhydride, and the diol, to each run is charged 0.1510 g of Erganox 1098 and 0.16 ml of a catalyst solution. Preparation of catalyst solution: to 0.5000 g of anhydrous magnesium acetate is added 16.5 ml of methanol and 33 ml of a tetrabutyl titanate i nbutyl alcohol solution, previously prepared by mixing 12.3 ml of tetrabutyl titanate in 100 ml of nbutyl alcohol.
TABLE 3__________________________________________________________________________Example Weight Percent Mole PercentNo. Type of A Unit Type of B Unit A B A B__________________________________________________________________________I Tetramethylene-4,4'- Tetramethylene-2-hexadecenylsuccinate 70 30 72 28(ethylenedioxy)bisbenzoateII Same as in I Tetramethylene-2-tetradecenylsuccinate 70 14 72 14 Tetramethylene-2-octadecenylsuccinate 16 14III Same as in I Tetramethylene-2-butenylsuccinate 70 30 60 40IV Same as in I Tetramethylene-2-triacontenylsuccinate 70 30 79 21V Same as in I Tetramethylene-2-decenylsuccinate 95 5 94 6VI Same as in I Tetramethylene-2-hexadecenylsuccinate 50 50 53 47VII Ethylene-4,4'- Ethylene-2-hexadecenylsuccinate 70 30 72 28(ethylenedioxy)bisbenzoateVIII Same as in I Tetramethylene-2-octadecenylsuccinate 75 25 78 22IX Same as in I Tetramethylene-2-octadecenylsuccinate 70 30 73 27X Same as in I Tetramethylene-2-octadecenylsuccinate 60 40 64 36__________________________________________________________________________
EXAMPLE XI
Ten grams of the copolymer described in Example I are packed into the extrusion chamber of an Instron Rheometer equipped with a 40 mil die and, after 10 minutes of dwell time, the sample is extruded at a ram speed of 2 cm/minute, and a temperature of 200° C. The takeup speed of the extrudate is 18 ft/minute and the extrudate is quenched in ice water. The diameter of the extrudate is 19 to 23 mils.
The extrudate is drawn at 5× through a glycerine bath held at a temperature of 55° C. and at 1.2× through a second glycerine bath heated to 70° C. The resulting fiber is washed in a water bath (room temperature) to remove the glycerine and taken up on a spool. The total draw ratio for both the first and second drawing stage is 6×. Tensile data for fiber obtained by this and other extrusion and draw experiments are shown in Table 1. | Copolymers of an (ethylenedioxy)bis benzoate, an alkylene diol and a (2-alkenyl or alkyl) succinic anhydride, as well as surgical devices formed therefrom; especially, flexible monofilament surgical sutures having unique handling and knot-tying characteristics. | 2 |
BACKGROUND
[0001] In the hydrocarbon recovery industry, many different tubular well tools and components are run in the hole over the life of the well. These components are required to be connected to a work string and then generally released in the downhole environment and the workstring removed from the well. While there are several methods for accomplishing this result, there are infinitely more possible situations encountered in the downhole environment that need to be overcome than methods and apparatus to address them. In view of this reality, the art is always receptive to alternative configurations to assist in delivering tubular well tools into the downhole environment.
SUMMARY
[0002] A torque transfer arrangement includes a relatively immobile construct; a relatively mobile construct radially adjacent the relatively immobile construct; and one or more torque valve assemblies mounted to the relatively mobile construct and radially responsive to applied hydraulic pressure to contact a surface of a separate structure and transmit torque from the arrangement to the separate structure.
[0003] A torque valve assembly includes a torque valve; and a torque button movably attached to the valve.
[0004] A torque transfer arrangement includes a first mandrel and a second mandrel interconnected by a mandrel piston; a torque button carrier having one or more torque valve assemblies mounted therein disposed about the first mandrel; a hydraulically sealed annular space defined between the first mandrel and the carrier, the one or more assemblies in operable communication with the space; and a sleeve fixedly attached to the carrier and in hydraulically sealed contact with the mandrel piston, the sleeve further being fixedly attached to a deactivate piston, the sleeve, mandrel piston, second mandrel and deactivate piston defining a hydraulically sealed chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0006] FIG. 1 is a schematic cross-sectional view of a torque transfer arrangement in an unactuated position;
[0007] FIG. 2 is a schematic cross-sectional view of the FIG. 1 embodiment in an actuated position but in the sequence to deactivate;
[0008] FIG. 3 is a schematic cross sectional view of the embodiment of FIG. 1 in a fully deactivated position;
[0009] FIG. 4 is an enlarged schematic cross-section view of a pressurization check valve of the arrangement;
[0010] FIG. 5 is an enlarged schematic cross-section view of a torque valve and torque button in situ; and
[0011] FIG. 6 is a perspective view of the torque valve and torque button of FIG. 5 removed from the arrangement.
DETAILED DESCRIPTION
[0012] Referring to FIGS. 1-3 simultaneously, three sequential positions of the torque transfer arrangement 10 are illustrated. In FIG. 1 , the arrangement 10 is in a position where it has been introduced to a tubular member 12 , which may be a casing or other tubular member and before actuation of the arrangement 10 to engage the tubular member 12 in a way that is effective in transferring torque from the arrangement 10 to the tubular member 12 . FIG. 2 illustrates the arrangement 10 in a position wherein it is engaged with the casing 12 but is also in a position where that engagement is about to be removed. FIG. 3 illustrates the arrangement 10 in a fully deactivated position.
[0013] Referring to FIG. 1 , the arrangement 10 includes a first mandrel 14 and a second mandrel 16 . It is to be understood that the terms first and second are not intended to indicate order but rather are used only to distinguish different structural features of the arrangement 10 . The two mandrels are interconnected physically and fluid conveyingly by a mandrel piston 18 . Components 14 , 16 and 18 (a relatively immobile construct) in this embodiment are relatively fixedly connected to a remote location through a running string (not shown) such as the surface of the well while other components to be introduced hereunder are movable thereon.
[0014] Disposed about the first mandrel 14 is a torque button carrier 20 . Torque button carrier 20 houses one or more torque button valves 22 which each make up a part of a torque valve button assembly 24 . The assemblies 24 , in one embodiment, are equidistantly spaced about a periphery of the carrier 20 since distribution as such will tend to center the arrangement 10 in the tubular member and thereby equally distribute stresses therearound. It is noted, however, that it is also possible to arrange the assemblies in an eccentric arrangement if desirable for a particular situation. In the illustrated embodiment, the cross-section shows only two of the torque button valve assemblies 24 but one of ordinary skill in the art will appreciate the possible spacing of other valves in the event that the arrangement 10 constructed includes more than two assemblies 24 . The number of assemblies employed is limited only by the practicality of available space and is thus somewhat dictated by the diameter of the arrangement 10 . It is noted that with increasing number of assemblies 24 , a greater total piston surface area is available to create radially directed force and so the torque holding ability of the arrangement 10 increases proportionally with the number of assemblies 24 .
[0015] In addition to the assemblies 24 , the torque button carrier 20 also houses a check valve 28 (see FIG. 4 ) that is not visible in FIGS. 1-3 because it is located, for this embodiment, out of the plane of the cross-section taken. The placement is for manufacturing and durability reasons and may be changed at will by a manufacturer without change of function of the arrangement 10 .
[0016] The carrier 20 is movably disposed about the first mandrel 14 and fluid sealingly engaged therewith through seals 30 and 32 , which in some embodiments are O-rings. Between the seals 30 and 32 is created an annular space 34 (see also FIGS. 4 and 5 ) through which hydraulic fluid is supplied to the one or more assemblies 24 . Hydraulic fluid is supplied to the annular space 34 through the check valve 28 . While the arrangement 10 is in the position illustrated in FIG. 1 , pressure supplied through check valve 28 is directed through the annular space 34 to the assemblies 24 . The reaction of the assemblies to the hydraulic fluid pressure will be addressed hereunder. It should be pointed out now, however, that the positions in which the arrangement 10 is illustrated in FIGS. 2 and 3 , are both incapable of holding the hydraulic fluid pressure in the annular space 34 as seal 32 will leak that pressure into recess 36 in mandrel 14 .
[0017] The carrier 20 is connected to a sleeve 38 that is fixedly attached to the carrier 20 at interconnection 40 , which may be a threaded connection. The sleeve 38 is also fixedly interengaged with a deactivate piston 42 at interengagement 44 , which may be a threaded connection. The carrier 20 , sleeve 38 and deactivate piston 42 (a relatively mobile construct) thus move as a unit when an appropriate stimulus is present. In order to move the carrier, sleeve and piston, pressure is applied at the inside dimension 46 of the arrangement 10 . The pressure in one embodiment is applied from a surface location. Such pressure in the inside dimension of the arrangement 10 is channeled through one or more (three visible) channels 48 to a chamber 50 . The chamber 50 is fluidically sealed at each end thereof by seals 52 , 54 and 56 . Pressure in the chamber 50 thus acts on the only volumetrically changeable surface, piston face 58 , of the chamber 50 . Upon the application of sufficient pressure in chamber 50 , the piston 42 will move in a direction away from the mandrel piston 18 , pulling sleeve 38 and consequently carrier 20 with it. In this way the arrangement 10 can be disengaged from the tubular member 12 and thereafter retrieved or otherwise as desired. Further details of this process are provided hereunder.
[0018] Referring now to FIGS. 4 , 5 and 6 a more detailed explanation of the check valve 28 , torque valve assemblies 24 and their functions are provided. The check valve 28 is disposed in a fluid conduit 60 that is connectable to a fluid pressure source (not shown) such as a hydraulic control line that may extend from a surface location. The check valve is configured to allow hydraulic fluid to flow therepast in a direction toward the annular space 34 . The valve itself includes a check valve cap 62 with a check valve o-ring 64 sealingly disposed about the cap 62 . The cap 62 is fixedly connected to a check valve stem 66 around which is disposed a check valve spring 68 . A spring retainer 70 is disposed about the spring to hold it in place. Once fluid is urged past the check valve 28 by unseating the o-ring 64 from an o-ring seat 72 with which it is sealingly engaged during times when the valve 28 is at rest, the fluid pressurizes the annular space 34 . Once a desired pressure inside annular space 34 is achieved, the valve 28 will close due to a lack of excess pressure applied to the valve from the remote location. At that point, pressure in the control line (not shown) can be reduced or eliminated, as the pressure created in the space 34 cannot escape back through the valve 28 . This is because the greater pressure in the annular space 34 urges the valve into a position where the o-ring 64 is repositioned back into sealing engagement with the o-ring seat 72 thereby preventing fluid movement out of the annular space 34 .
[0019] The pressure in annular space 34 directly acts on the assembl(ies) 24 , urging them to move radially. In the illustrated embodiment, the radial movement is outwardly but it is to be appreciated that the parts hereof could be reversed to cause the actuation to move the assemblies radially inwardly if desired. Focusing on FIGS. 5 and 6 , one of the assemblies 24 is illustrated in an enlarged view. Each of the assemblies 24 includes a torque valve 22 that comprises a valve stem 80 having a seal 82 such as an o-ring therearound to seal against a bore 84 in the torque valve carrier 20 . This seal, and others of the one or more assemblies 24 , provides a pressure tight moveable portion exposed to the pressure of the annular space 34 . Upon rising pressure in the space then, the assemblies 24 will move radially outwardly (illustrated embodiment).
[0020] Additional components of the assemblies 24 include a return spring 86 disposed about the valve stem 80 and bounded by a valve cap 88 . The valve cap 88 is fixedly positioned within the bore 84 by any affixing means such as threads, press fit, adhesive, welding, brazing, etc. as the force borne thereby is only that generated by the spring 86 . The valve stem 80 includes a flange 90 that is used as a bearing surface for bearing or bushing 92 . Riding upon bearing 92 is a torque button 94 . The torque button 94 is attached to the valve stem 80 with fastener 96 , which may be a threaded fastener or other similar affixing means. Referring to FIG. 6 , the button 94 includes an elongated opening 98 for fastener 96 to slide in during operation of the device as described in greater detail hereunder. Such sliding is assisted by the bearing 92 , which as noted could also be a type of bushing and ultimately need only reduce a coefficient of friction at an interface 100 between the button 94 and the valve stem 80 . Each torque button 94 is rotationally fixed within the carrier 20 while being radially and axially movable therein by being disposed in a respective opening 102 such as a slot in an outer surface 104 of the carrier 20 . Visible in FIG. 5 are a lateral wall 106 , an axial wall 108 and a radially inwardly positioned wall 110 of the slot 102 . The dimensions of the slot are such that the button 94 (one embodiment of which is shown in FIG. 6 ) is allowed to move radially and axially in at least one axial direction based upon the movements of the arrangement 10 disclosed herein.
[0021] Still referring to FIG. 5 , when pressure in the annular space 34 is sufficiently raised to overcome the spring force of spring 86 , the assembly 24 will react by moving radially outwardly until a surface 112 of the button 94 contacts an inside dimension surface 114 of the tubular member 12 . The degree of force to be generated upon the surface 114 depends upon desired torque holding capacity and the conditions (such as temperature and pressure) at the location of the intended use of the torque holding capacity. The capacity is adjusted by the pressure supplied to the annular space 34 with higher pressures yielding higher torque carrying capacity. Care should be taken not to over pressurize the annular space 34 to prevent the tubular member 12 itself failing.
[0022] Referring back to FIGS. 1-3 , operation of the arrangement 10 is described in greater detail. As noted, FIG. 1 illustrates the arrangement within the tubular member 12 but in an unactuated condition. In other words, the annular space has not yet been provided with a pressurization. Upon pressurization of the annular space 34 , the assemblies 24 react as above stated and bring the buttons 94 into contact with the inside surface 114 of the tubular member 12 . The force will be as selected using the pressure source. Once the desired pressure is supplied to the annular space 34 and the buttons have consequently generated the desired contact force against the tubular member 12 , the arrangement 10 and the member 12 are run into the hole. When the position of the tubular member 12 is as selected by an operator and it is desired to release the tubular member, pressure is applied to an inside of the running string (not shown) which is fluidly connected to the inside dimension 46 of the arrangement 10 . This pressure as noted above will migrate to chamber 50 ultimately causing carrier 20 to move relative to the mandrel 14 . In order to prevent damage to the inside surface 114 of the tubular 12 , the buttons 94 will not move with the carrier 20 but rather will stay in place while the carrier 20 moves. This is illustrated in FIG. 2 . The reader should view the position of the torque valve 22 relative to the button 94 in FIG. 1 and then FIG. 2 to appreciate the movement described. When the carrier 20 reaches the position illustrated in FIG. 2 , it is to be appreciated that seal 32 is very close to an edge of recess 36 and so will bleed pressure from annular space 34 . As pressure is bled from the space 34 , the spring(s) 86 of the various one or more torque valves 22 will begin to provide more force than that of the hydraulic fluid acting thereagainst. At this point, the buttons will disengage the surface 114 and the stroke of the carrier 20 can continue until complete disassociation of the button(s) 94 with the surface 114 is achieved. The arrangement is then ready to be retrieved from the hole and is as it appears in FIG. 3 .
[0023] It is to be understood that although the above description with regard to release of the tubular member is directed to hydraulic pressure buildup within an ID of the string, it is also possible to mechanically shift the arrangement 10 by such as a pick up and slack off sequence.
[0024] While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A torque transfer arrangement includes a relatively immobile construct; a relatively mobile construct radially adjacent the relatively immobile construct; and one or more torque valve assemblies mounted to the relatively mobile construct and radially responsive to applied hydraulic pressure to contact a surface of a separate structure and transmit torque from the arrangement to the separate structure and method. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the liners for end burning solid rocket propellant motors. More particularly, this invention relates to an ablative liner. Additionally, this invention relates to a liner which reduces the coning effect in end burning solid rocket propellant motors.
2. Description of the Prior Art
The coning of a solid rocket propellant grain has been a problem in prior end burning rocket motors. Coning results from the more rapid burning of propellant grain near the casing than in the center of the motor. Various liners have been used to protect rocket motor casings from the heat evolved during burning and certain liners can help reduce coning. Some liners, containing fiberous materials such as asbestos, give increased protection against high temperatures by functioning as ablators. The use of asbestos, however, has raised enviromental concerns due to its carcinogenic effects. An asbestos free ablative liner which reduces the coning of the burning propellant grain has been sought.
SUMMARY OF THE INVENTION
This invention employs noncarcinogenic fibers of novoloid mixed in a polymeric rubber liner. Upon burning of the propellant, the novoloid fibers resist burning and produce a charred mat of carbonized fibers. This charred mat gives additional protection from the high temperature exhaust gases to the motor casing. It is an object of the present invention to provide an improved ablative liner for rocket motors.
A further object of this invention is to provide an ablative lining which reduces the coning of the propellant and the amount of carcinoginic by-products.
Another object of the invention is to provide a method of manufacturing a rocket motor utilizing the ablative liner. These and other objects of the invention will become more readily apparent from the ensuing specification when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a rocket motor;
FIG. 2 is a view taken along line 2--2 of FIG. 1 showing the fibers throughout the liner; and
FIG. 3 is a flow diagram of a method of production.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a rocket motor 10 is shown as including a casing 11, which is constructed from steel or any other suitable metal. Adjacent to casing 11 is a thin layer of silicone rubber 12. By applying a silicone rubber primer to casing 11, a strong bond may be achieved to silicone rubber 12. An ablative lining 13 is shown interior to silicone rubber 12. Lining 13 is made from a combination of a prepolymer and a premix. Their required ingredients include polypropylene glycol (PPG), N-Mono(hydroxyethyl)-N,N',N'-tris(2-hydroxypropyl) ethylenediamine (MTDA), tolylene-2,4-diisocynate (TDI), N-phenyl-N'-cyclohexyl-p-phenylenediamine (PCHPDA), titanium dioxide, activated ferric acetylacetonate (FeAA), and novoloid fibers which are cross-linked phenol-formaldehyde. The nominal chemical composition of lining 13 is as follows:
______________________________________Constituent % by Weight______________________________________PPG 74.50MTDA 1.00TDI 10.38PCHPDA 0.62TiO.sub.2 (ground) 10.00Fibers (1 millimeter in length and 2.0014 microns in diameter)FeAA (activated) 1.50______________________________________
A rocket propellant grain 14 fills the inner core within lining 13.
In operation lining 13 bonds to grain 14, but does not bond to silicone rubber 12. By releasing from casing 11, lining 13 and propellant 14 remain in a low stress condition, because they are free to contract and expand independently of casing 11 during temperature changes. Lining 13 serves to protect the surface of grain 14 from the hot gases circulating within the motor during combustion, preventing backside grain ignition. Further, lining 13 ablates as the end burning grain face advances along the length of casing 11. The remaining char mat containing carbonized novoloid fibers helps protect the sidewalls of casing 11 from the high temperature exhaust gases.
Referring to FIG. 2, the novoloid fibers 16 are shown interspersed throughout lining 13.
Referring to FIG. 3, the flow diagram illustrates a method of manufacture of the invention. A silicon rubber primer is applied as indicated by box 20 to a clean motor casing 11 and allowed to run the full length of the case. The casing is spun by any suitable method to spread the primer evenly over the inner surface of the casing. The primer is air dried at ambient conditions for at least one hour, the primer effects a strong bond between the case interior wall and the silicone rubber. Silicone rubber is mixed with suitable catalyst, poured into the casing and then spread over the casing at a nominal length of 0.005 inches by means of a paint brush, roller, or other suitable means as indicated by box 21. The casing is spun and heated to cure the silicone rubber layer. A suitable temperature has been found to be 90° F. when spinning is for 24 hours.
Next, the prepolymer and premix are prepared. The percentages of ingredients in the prepolymer and premix are dependent upon the laboratory determined values of hydroxyl equivalents per hundred grams of PPG and isocyanate equivalents per hundred grams of TDI. Typically, these numbers vary with different lots of PPG and TDI and thus the percentages of ingredients in the prepolymer and premix change whenever there is a lot change in PPG or TDI.
Four equations have been developed to describe the quantities of the required ingredients as parts of a 200-part system of prepolymer and premix. The amount of the PCHPDA, TiO 2 , FeAA and the novoloid fibers are kept at a constant total value of 28.24 parts of a 200 part system. The equations with experimentally developed constants are: ##EQU1## A=PPG in Premix (parts/200); B=PPG in Prepolymer (parts/200);
Y=MTDA in Premix (parts/200);
Z=TDI in Prepolymer (parts/200);
E x =Hydroxyl (OH) equivalents/100 grams of PPG;
E z =Isocyanate (NCO) equivalents/100 grams of TDI; and
E y =Hydroxyl (OH) equivalents/100 grams of MTDA=1.437 (theoritical value).
The four equations are solved simultaneously for A, B, Y and Z. Then, K 1 and K 2 are calculated with ##EQU2##
This allows the percentages of each ingredient in the respective prepolymer and the premix to be determined. Additionally, K 2 /K 1 defines the mix ratio of prepolymer to premix required to produce lining 13.
______________________________________Ingredient Prepolymer % Premix %______________________________________PPG BK.sub.1 AK.sub.2MTDA -- YK.sub.2TDI ZK.sub.1 --PCHPDA 0.8K.sub.1 0.44K.sub.2TiO.sub.2 20.0K --Novoloid fibers 4.0K.sub.1 --FeAA -- 3.0K.sub.2______________________________________
To prepare the prepolymer as indicated by box 22, a mixing pot is preheated, as shown in box 24, by a water jacket for at least 30 minutes at 95° F. to 105° F. Preground titanium dioxide is screened through a number 10 mesh Tyler screen. Both the titanium dioxide and the novoloid fibers are preheated at 170° F. to 190° F. for a minimum of 24 hours prior to mixing.
As indicated by box 26, the next step in prepolymer preparation 22 is to add the PPG, TDI, PCHPDA, titanium dioxide and the novoloid fibers to the preheated pot. Then, as shown in box 28, mixing is conducted under a nitrogen atmosphere. Following about 24 hours of mixing in box 28 with the water jacket at 150° F., chilled water of about 50° F. is introduced into the water jacket to cool the mixture as indicated by box 30. The mixing is continued until the product temperature reaches 120° F. to 130° F. The prepolymer is then poured into cans of suitable size and aged, as indicated by box 32, for ten days at 70° F. to 80° F. The prepolymer should then be stored in refrigeration between 35° F. and 45° F.
To prepare the premix as indicated by box 34, a mixing pot is preheated, as shown in box 36, by a water jacket for at least 60 minutes at 175° F. to 185° F. The FeAA is activated by heating for eighteen days while exposed to slowly circulating air at 175° F. to 185° F. It is screened through a number 32 mesh Tyler screen and preheated at 175° F. to 185° F. for a minimum of 24 hours prior to mixing.
As indicated by box 38, the next step in premix preparation 34 is to add the PPG, PCHPDA, MTDA and FeAA to the preheated pot. Then, as shown in box 40, mixing is conducted under a vacuum (˜5 mm Hg). Following about 4 hours of mixing with the water jacket at 180° F., chilled water of about 50° F. is introduced into the water jacket to cool the mixture as indicated by box 42. The mixing is continued until the product temperature reaches 140° F. to 145° F. The premix is poured into one gallon cans for convenience and stored at an ambient temperature of 60° to 95° F.
Both the premix and the prepolymer should be used within ninety days of preparation. After the preparation of the premix and the prepolymer, the ablative lining can be applied to the casing 11 over the silicone rubber layer 12. As indicated by box 43, the ablative lining is most effectively applied by sling lining. Any other suitable method, such as spin lining, maybe substituted. The final step, as indicated by box 44, is to cast the grain 14 into the rocket motor.
One specific mixture tested and found suitable had the following composition:
______________________________________ Prepolymer Prepolymer Premix PremixIngredient (%) (weight) (%) (weight)______________________________________PPG 55.3257 93.29 lbs 94.4487 153.07 lbsMTDA -- -- 2.0417 1500.9 gramsTDI 20.3557 34.32 lbs -- --PCHPDA 0.7845 600.0 grams 0.4489 330.0 gramsTiO.sub.2 19.6114 33.07 lbs --(Ground)Fibers 3.9223 3000.0 grams -- --(Kynol)FeAA -- -- 3.0606 2250.0 grams(Activated) 100.000% 76,486 grams 100.000% 73,514 grams______________________________________
The prepolymer was mixed with the premix for these particular batches in a ratio of 1.0404 parts prepolymer per part premix.
The foregoing description taken together with the appended claims constitute a disclosure such as to enable a person proficient in the rocket motor arts and having the benefit of the teachings contained therein to make and use the invention.
Obviously, many modifications and variations of the present invention are possible in the light of the above teachings, and, it is understood that within the scope of the disclosed inventive concept, the invention may be practiced otherwise than specifically described. | An improved rocket motor has a first layer of silicone rubber and a secondayer of an ablative lining placed between the rocket motor casing and the propellant grain. The ablative lining layer contains chopped novoloid fibers 14 microns in diameter and nominally 1 mm in length interspersed throughout a polymeric composition. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a latch apparatus for a blast-resistant container, particularly to a latch apparatus for a blast-resistant container having a latch with a curved surface and a wedge plate which during a locking process push a chain hook tightly into a seat, so that in a locked state the chain hook will not loosen and will expose only a short lever arm, providing improved protection from a blast.
DESCRIPTION OF RELATED ART
[0002] As shown in FIG. 7 , Chinese patent no. CN ZL02230761.3 discloses a strengthened door structure having four sides each being furnished with a hook A and a hook seat C on a sliding door plate B. During a closing movement of the sliding door towards a closing edge (right side in the Fig.), the hook seat C to the right on the sliding door plate B engages with a chain hook D. For convenience of engaging chain hook D and hook seat C, the chain hook D is given a generous angular range. To prevent the chain hook D from disengaging from the hook seat C, which would impair resistance against a blast, at least one latch secures the chain hook D in the engaged position thereof.
[0003] As shown in FIG. 8 , the engagement structure cited above further has a clamp E attached to the sliding door plate B for preventing the chain hook D from disengaging from the hook seat C. However, this arrangement does not provide for a sufficiently precise movement of the chain hook, and a test of resistance against blasts requires a large amount of time for position checking.
[0004] Referring now to FIG. 9 , Taiwan patent no. 171592 discloses a latch apparatus comprising a handle F mounted on a sliding door plate B, a latch G, and a supporting spring H, which after releasing the handle F drives automatic closing of the latch apparatus.
[0005] As shown in FIG. 10 , Taiwan patent no. 197769 discloses a latch apparatus similar to the latch apparatus shown in FIG. 9 , comprising a handle I and a latch J, but having a wave-shaped plate spring K substituted for the supporting spring for positioning the handle I.
[0006] To summarize, The latch apparatuses shown in FIGS. 8-10 provide only for blocking in a horizontal direction, preventing the chain hook D from disengaging from the hook seat C, but not for positioning of the chain hook D relative to the hook seat C. Usage and looks of these latch apparatuses are in need of improvement.
[0007] Above conventional latch apparatuses all do not allow to fix the relative positions of the chain hook D and the hook seat C, with a gap left in between. As shown in FIGS. 11A and 11B . When an explosion occurs in the container. The shock wave will indure extremely high membrane stress on the container structure instantly. If lever arms L 1 >L 2 formed by the chain hook D and the hook seat C. Since the lever arms are relatively large, high bending stress and subsequent damage result, and resistance against blasts is lost.
SUMMARY OF THE INVENTION
[0008] It is the object of the present invention to provide a latch apparatus for a blast-resistant container having a latch with a curved surface and a wedge plate which during a locking process push a chain hook tightly into a seat, so that in a locked state the chain hook will not loosen and will expose only a short lever arm, providing improved protection from a blast.
[0009] The present invention can be more fully understood by reference to the following description and accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] The latch apparatus for a blast-resistant container of the present invention comprises: a door plate 10 with a front side and a rear side; a base 20 ; a connecting piece 30 ; a latch 40 ; a nut 50 ; and a chain hook 60 fastened to an edge of a container. The base 20 and the connecting piece 30 together pass through the doorplate 10 . The latch 40 is mounted on the connecting piece 30 , performing a turning movement thereon. Further details will be explained below.
[0011] A hook seat 11 is fastend on the doorplate 10 . The doorplate 10 has a through hole 12 surrounded by holes 13 .
[0012] The base 20 comprises an axis 21 and a base plate 22 attached thereto. The base plate 22 is placed on the rear side of the door plate 10 , with the axis 21 reaching through the through hole 12 , having a far end with a thread 24 on the front side of the door plate 10 . Positioning holes 23 on the base plate 22 surround the axis 21 .
[0013] The connecting piece 30 comprises a tubelet 31 with a front end and a rear plate 33 attached to the tubelet 31 opposite to the front end thereof. The connecting piece 30 is put over the base 20 , with the tubelet 31 surrounding the axis 21 and the rear plate 33 being set on the front side of the door plate 10 . A step 32 is cut into the tubelet 31 near the front end thereof. The rear plate 33 has a rear side from which several pins 34 extend rearward.
[0014] The latch 40 at a central hole 41 thereof is set on the rear end of the tubelet 31 of the connecting piece 30 . A handle 42 is integrated into the latch 40 . Opposite to the handle 42 the latch has an engaging section with a curved surface 43 . A wedge plate 44 with a wedge-shaped cross section is attached to the latch 40 . The central hole 41 is surrounded by a circular depression 41 a.
[0015] The nut 50 is screwed on the thread 24 of the axis 21 of the base 20 .
[0016] The chain hook 60 is fastened to the container and is, as well as the hook seat 11 , made using conventional art, which does not need to be explained further.
[0017] The present invention is assembled by first having the axis 21 of the base 20 pass through the through hole 12 of the door plate 10 , so that the base plate 22 leans close to the door plate 10 at the rear side thereof. Then the tubelet 31 of the connecting piece 30 is put on the far end of the axis 21 , with the pins 34 passing through the holes 13 in the door plate 10 and the positioning holes 23 of the base 20 , preventing the connecting piece 30 from turning around the axis 21 . After that, the latch 40 is at the central hole 41 thereof set on the tubelet 31 of the connecting piece 30 , allowing the latch 40 to turn around the tubelet 31 . Finally, the nut 50 is put on the far end of the axis 21 and screwed tight on the thread 24 thereof, preventing the latch 40 from separating from the connecting piece 30 .
[0018] As shown in FIGS. 2A and 2B , in an open state, the latch 40 is placed to the left of the chain hook 60 , with the curved surface 43 thereof leaning against a hook 61 of the chain hook 60 . In this state, the hook 61 is not engaged with a groove 14 of the hook seat 11 . Therefore, the doorplate 10 can be freely opened or closed using the handle 42 .
[0019] Referring to FIGS. 2C and 2D , in a locked state, the handle 42 has been moved down, as indicated by the arrow, resulting in the curved surface 43 pushing the hook 61 of the chain hook 60 into the groove 14 of the hook seat 11 . At the same time, the wedge plate 44 , due to the shape thereof, pushes the hook 61 close to the hook seat 11 , minimizing a resulting lever arm composed of the hook 61 and the hook seat 11 (see FIGS. 11A and 11B , L 2 <L 1 ). Thus resistance against a blast is improved.
[0020] In the embodiment shown, the latch 40 undergoes a turning angle of 90 degrees between the open and locked states. By altering the dimensions of the curved surface 43 and the wedge plate 44 , the turning angle is variable. FIGS. 3A and 3B show a latch with a turning angle of 180 degrees.
[0021] Referring to FIG. 4 , in a second embodiment of the present invention, a helical spring 70 is inserted into said circular depression 41 a of said latch 40 . After the chain hook 60 having entered the groove 14 of the hook seat 11 , the spring 70 stably holds the latch 40 .
[0022] Referring to FIG. 5 , in a third embodiment of the present invention, the latch 40 has a positioning device 401 for positioning of the latch 40 in several steps. The positioning device 401 comprises several depressions 35 on a peripheral outer surface of the tubelet 31 of the connecting device 30 , a tunnel 45 on the curved surface 43 , which is connected with the central hole 41 , a steel ball 46 , a spring 47 , and a threaded worm 48 . The steel ball 46 and the spring 47 are inserted into the tunnel 45 and held there by the threaded worm 48 . The steel ball 46 is pressed against the peripheral surface of the tubelet 31 . Turning of the latch 40 causes the steel ball 46 to wander around the tubelet 31 , stably remaining in the depressions 35 thereof at certain angular positions of the latch 40 , thus providing angular positioning of the latch 40 .
[0023] Referring to FIG. 6 , in a fourth embodiment of the present invention, the handle 42 has a handle grip 49 that perpendicularly extends away. In the open state, the handle grip 49 is oriented perpendicular to an opening direction of the doorplate 10 , allowing to open the doorplate 10 by pushing the handle grip 49 .
[0024] The main characteristic of the present invention, as compared to conventional art, lies in that upon closing the door, the latch at the curved surface and wedge plate thereof quickly and precisely pushes the hook into the hook seat, keeping the hook in a tight position, thus achieving maximum resistant against various kinds of blasts.
[0025] While the invention has been described with reference to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention which is defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view of the latch apparatus of the present invention when disassembled.
[0027] FIGS. 2A-2E are schematic views of the latch apparatus of the present invention with the hook seat and the chain hook disengaged or engaged.
[0028] FIGS. 3A and 3B are perspective views of the latch of the present invention designed for a turning angle of 180 degrees.
[0029] FIG. 4 is a perspective view of the latch apparatus of the present invention in the second embodiment when disassembled.
[0030] FIG. 5 is a perspective view of the latch apparatus of the present invention in the third embodiment when disassembled.
[0031] FIG. 6 is a perspective view of the latch of the present invention in the fourth embodiment.
[0032] FIG. 7 (prior art) is a side view of a conventional blast-resistant container structure.
[0033] FIG. 8 (prior art) is a perspective view of a chain hook engaged with a hook seat of a conventional latch apparatus.
[0034] FIG. 9 (prior art) is a side view of another conventional latch apparatus.
[0035] FIG. 10 (prior art) is a side view of a further conventional latch apparatus.
[0036] FIG. 11 (prior art) is a schematic illustration of lever arms resulting from the hook seat engaging with the hook of a conventional latch apparatus. | A latch apparatus for a blast-resistant container, comprising a chain hook on an edge of the container, a hook seat on a sliding door, a base, a connecting piece, a latch and a nut. The latch has a curved surface next to the hook seat and a front plate with a wedge-shaped cross-section. When the latch is turned into a locked state, the curved surface and front plate thereof push a hook on the chain hook tightly into the hook seat, so that in the locked state the chain hook will not loosen and will expose only a short lever arm, providing improved protection from a blast. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an electrophoresis apparatus and method suitable for electrophoretically altering the original composition of a mixture that contains at least one ampholytic component.
[0002] When ampholytic compounds, such as amino acids, peptides, oligopeptides, proteins, and the like are present in a solution at a low concentration, their charge-state depends on the pH of their environment. At a certain characteristic pH value, the net charge—and consequently, the electrophoretic mobility—of an ampholytic compound becomes zero. That pH value is called the pI value of the ampholytic compound. When two ampholytic compounds have different pI values, their net charge becomes zero at different pH values. Thus, if a pH gradient is established in an electric field, the two ampholytic species achieve zero net charge at different points of the pH gradient that can result in their separation. Such separations are called isoelectric focusing (IEF) separations. IEF separations have been achieved in (i) artificial pH gradients created from non-amphoteric buffers either at constant or spatially varying temperatures, (ii) natural pH gradients created from carrier ampholytes or from the very components of the mixture to be separated (autofocusing), and (iii) immobilized pH gradients.
[0003] IEF separations typically rely on anti-convective means to preserve the stability of the pH gradient. The IEF principle has been utilized for both analytical and preparative-scale separation of both simple and complex mixtures of ampholytic components. IEF separations have been obtained in thin-layer format, column-format and in multi-compartment format, in both static and flowing media. In flowing media, separations have been achieved in both straight-through and recycling format. IEF separations often take considerable time because the electrophoretic mobility of each ampholytic species becomes low as they approach the point in the pH gradient where they become isoelectric.
[0004] Therefore, there is a need for IEF separation schemes and equipment which (i) minimize the distance the components have to migrate electrophoretically to achieve separation, (ii) maximize the electric field strength that brings about the electrophoretic separation without causing detrimental heating effects, (iii) maximize the production rate that can be achieved in unit separation space and time, and (iv) minimize the use of auxiliary agents needed for the electrophoretic separation.
[0005] The present invention provides an apparatus and method which can electrophoretically alter the original composition of a mixture that contains at least one ampholytic component.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, there is provided an electrophoresis apparatus and method which can electrophoretically alter the original composition of a mixture that contains at least one ampholytic component.
[0007] Further, in accordance with the present invention, there is provided an electrophoresis apparatus and system which (i) minimizes the distance the components have to migrate electrophoretically to achieve separation, (ii) maximizes the electric field strength that brings about the electrophoretic separation without causing detrimental heating effects, (iii) maximizes the production rate that can be achieved in unit separation space and time, and (iv) minimizes the use of auxiliary agents needed for the electrophoretic separation.
[0008] Still further, in accordance with the present invention, there is provided an electrophoretic apparatus comprising:
[0009] a first electrolyte chamber containing a first electrode;
[0010] a second electrolyte chamber containing a second electrode, wherein the second electrolyte chamber is disposed relative to the first electrolyte chamber so that the electrodes are adapted to generate an electric field in an electric field area upon application of a selected electric potential between the electrodes;
[0011] a first sample chamber disposed between the first and second electrolyte chambers and proximate to the first electrolyte chamber so as to be at least partially disposed in the electric field area;
[0012] a second sample chamber disposed between the first sample chamber and the second electrolyte chamber so as to be at least partially disposed in the electric field area;
[0013] a first ion-permeable barrier separating the first and second sample chambers so as to impede convective mixing of the contents in each of the first and second sample chambers;
[0014] a second ion-permeable barrier separating the first electrolyte chamber and the first sample chamber so as to impede convective mixing of the contents in each of the first sample chamber and the first electrolyte chamber;
[0015] a third ion-permeable barrier separating the second electrolyte chamber and the second sample chamber so as to impede convective mixing of the contents in each of the second sample chamber and the second electrolyte chamber;
[0016] a first electrolyte reservoir and a second electrolyte reservoir in fluid communication with the first and second electrolyte chambers, respectively;
[0017] a first sample reservoir and a second sample reservoir in fluid communication with the first and second sample chambers, respectively;
[0018] means adapted for communicating an associated first electrolyte between the first electrolyte chamber and the first electrolyte reservoir;
[0019] means adapted for communicating an associated second electrolyte between the second electrolyte chamber and the second electrolyte reservoir;
[0020] means adapted for communicating a first fluid between the first sample chamber and the first sample reservoir; and
[0021] means adapted for communicating a second fluid between the second sample chamber and the second sample reservoir, wherein at least one of the first and second fluid contains at least a sample,
[0022] wherein application of the selected electric potential causes migration of at least one component through at least one of the ion-permeable barriers.
[0023] In one preferred form, the first ion-permeable barrier is a membrane having a characteristic average pore size and pore size distribution. In one form, all the ion-permeable barriers are membranes having a characteristic average pore size and pore size distribution. This configuration of the apparatus is suitable for separating compounds on the basis of charge and or size.
[0024] In another preferred form, the first ion-permeable barrier is an isoelectric membrane having a characteristic pI value. Preferably, the isoelectric membrane has a pI value in a range of about 2 to about 12.
[0025] In another preferred form, the second and third ion-permeable barriers are membranes having a characteristic average pore size and pore-size distribution.
[0026] In another preferred form, at least one of the second or third ion-permeable barriers is an isoelectric membrane having a characteristic pI value. Preferably, the at least one isoelectric membrane has a pI value in a range of about 2 to about 12. In another preferred form, both the second and third ion-permeable barriers are isoelectric membranes each having a characteristic pI value. Preferably, the isoelectric membranes have a pI value in a range of about 2 to about 12. When both the second and third ion-permeable barriers are isoelectric membranes, the membranes can have the same or different characteristic pI values.
[0027] The isoelectric membranes are preferably polyacrylamide-based membranes. It will be appreciated, however, that other isoelectric membranes would also be suitable for the present invention.
[0028] In another preferred form, the apparatus further comprises means for circulating electrolyte from each of the first and second electrolyte reservoirs through the respective first and second electrolyte chambers forming first and second electrolyte streams in the respective electrolyte chambers; and means for circulating contents from each of the first and second sample reservoirs through the respective first and second sample chambers forming first and second sample streams in the respective sample chambers.
[0029] Preferably, means for circulating the electrolyte and sample streams are pump arrangements separately controllable for independent movement of the electrolyte streams and the sample streams.
[0030] The apparatus may further include means for removing and replacing sample in the first or second sample reservoirs. The apparatus may also further include means to maintain temperature of electrolyte and sample solutions.
[0031] In another preferred form, the separation unit is provided as a cartridge or cassette fluidly connected to the electrolyte reservoirs and the sample reservoirs. In one preferred form, the separation unit is provided as a cartridge or cassette connected to the electrolyte reservoirs and the sample reservoirs.
[0032] Still further, in accordance with the present invention, there is provided a method for selectively removing at least one component from a selected sample comprising:
[0033] communicating a first electrolyte to a first electrolyte chamber containing a first electrode wherein the first electrolyte chamber is in fluid communication with a first electrolyte reservoir;
[0034] communicating a second electrolyte to a second electrolyte chamber containing a second electrode, wherein the second electrolyte chamber is disposed opposite the first electrolyte chamber and wherein the second electrolyte chamber is in fluid communication with a second electrolyte reservoir;
[0035] communicating a first fluid to a first sample chamber disposed between the first and second electrolyte chambers and proximate to the first electrolyte chamber, wherein the first sample chamber is in fluid communication with a first sample reservoir;
[0036] communicating a second fluid to a second sample chamber disposed between the first sample chamber and the second electrolyte chamber, wherein the second sample chamber is in fluid communication with a second sample reservoir, wherein a first ion-permeable barrier separates the first and second sample chambers, a second ion-permeable barrier separates the first electrolyte chamber and the first sample chamber, and a third ion-permeable barrier separates the second sample chamber and the second electrolyte chamber, wherein the ion-permeable barriers impede convective mixing between the respective chambers, wherein at least one of the first and second fluids contains at least a sample; and
[0037] applying a selected electric potential to cause migration of at least one selected component through at least one of the ion-permeable barriers. Preferably, at least one sample component has a pI value.
[0038] In a preferred form, electrolyte from at least one of the first and second electrolyte reservoirs is circulated through the first or second electrolyte chamber forming a first or second electrolyte stream.
[0039] The choice of electrolyte in the first and second electrolyte chambers will depend on the compound or compounds to be treated, separated or transferred from a sample chamber to the other sample chamber, or one or both of the electrolyte chambers. Similarly, the choice of the pI of the isoelectric membranes will also depend on the compound or compounds to be treated, separated or transferred from a given sample.
[0040] Electrolytes such as acetic acid as the anolyte, and triethanol amine as the catholyte, have been found to be suitable for the separation of a number of components from biological samples. Salt such as NaCl may also be added to the electrolyte to assist. It will be appreciated, however, that other electrolytes would also be applicable, depending on the desired separation or treatment.
[0041] In another preferred form, electrolyte from both the first and second electrolyte reservoirs is circulated through the first and second electrolyte chambers forming first and second electrolyte streams.
[0042] In another preferred form, the contents of the first or second sample reservoir is circulated through the first or second sample chamber forming a first or second sample stream through the first or second sample chamber. In another preferred form, sample or liquid in the first or second sample reservoir is removed and replaced with fresh sample or liquid.
[0043] Preferably, substantially all transbarrier migration occurs upon the application of the electric potential. In another preferred form, the application of the electric potential is maintained until at least one desired component reaches a desired purity in at least one of the first and second sample chamber or in the first or second sample reservoirs.
[0044] Still further, in accordance with the present invention, there is provided an electrophoretic separation unit comprising:
[0045] a first electrolyte chamber containing a first electrode;
[0046] a second electrolyte chamber containing a second electrode, wherein the second electrolyte chamber is disposed relative to the first electrolyte chamber so that the electrodes are adapted to generate an electric field in an electric field area upon application of a selected electric potential between the electrodes;
[0047] a first sample chamber disposed between the first and second electrolyte chambers and proximate to the first electrolyte chamber so as to be at least partially disposed in the electric field area;
[0048] a second sample chamber disposed between the first sample chamber and the second electrolyte chamber so as to be at least partially disposed in the electric field area;
[0049] an isoelectric barrier separating the first and second sample chambers so as to impede convective mixing of the contents in each of the first and second sample chambers;
[0050] a first ion-permeable barrier separating the first electrolyte chamber and the first sample chamber so as to impede convective mixing of the contents in each of the first sample chamber and the first electrolyte chamber;
[0051] a second ion-permeable barrier separating the second electrolyte chamber and the second sample chamber so as to impede convective mixing of the contents in each of the second sample chamber and second electrolyte chamber;
[0052] means adapted for communicating an associated first electrolyte to the first electrolyte chamber;
[0053] means adapted for communicating an associated second electrolyte to the second electrolyte chamber;
[0054] means adapted for communicating a first fluid to the first sample chamber; and
[0055] means adapted for communicating a second fluid to the second sample chamber, wherein at least one of the first and second fluids contains at least a sample;
[0056] wherein application of the selected electric potential causes migration of at least one component through at least one of the ion-permeable barriers.
[0057] Still further, in accordance with the present invention, there is provided a method for selectively altering the concentration of a selected sample:
[0058] communicating a first electrolyte to a first electrolyte chamber containing a first electrode;
[0059] communicating a second electrolyte to a second electrolyte chamber containing a second electrode;
[0060] communicating a first fluid to a first sample chamber disposed between the first and second electrolyte chambers and proximate to the first electrolyte chamber;
[0061] communicating a second fluid to a second sample chamber disposed between the first sample chamber and the second electrolyte chamber, wherein an isoelectric barrier separates the first and second sample chambers, a first ion-permeable barrier separates the first electrolyte chamber and the first sample chamber, and a second ion-permeable barrier separates the second sample chamber and the second electrolyte chamber, wherein the barriers impede convective mixing between the respective chambers, wherein at least one of the first and second fluids contains a sample; and
[0062] applying a selected electric potential to cause migration of at least one selected component through at least one of the barriers.
[0063] An advantage of the present invention is that the apparatus and method have scale-up capabilities, increased separation speed, lower cost of operation, lower power requirements, and increased ease of use.
[0064] Yet another advantage of the present invention is that the apparatus and method have improved yields of the separated component, and improved purity of the separated component.
[0065] These and other advantages will be apparent to one skilled in the art upon reading and understanding the specification.
[0066] Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
[0067] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] [0068]FIG. 1 is a schematic diagram of a separation unit for use in the present invention.
[0069] [0069]FIG. 2 is a schematic diagram of an apparatus according to the present invention utilizing the separation unit of FIG. 1.
[0070] [0070]FIG. 3 is an exploded view of a cartridge which may be used with the separation unit of FIG. 1.
[0071] [0071]FIG. 4A is a plan view of a grid element which may be incorporated as a component of a cartridge of a separation unit.
[0072] [0072]FIG. 4B is a reverse plan view of the grid element of FIG. 4A.
[0073] [0073]FIG. 5 is a cross-sectional view on the lines X-X of FIG. 4A.
[0074] [0074]FIG. 6 is a cross-sectional view on the lines XI-XI of FIG. 4A.
[0075] [0075]FIG. 7 is a cross-sectional view on the lines XII-XII of FIG. 4A.
[0076] [0076]FIG. 8 is a plan view of an alternative embodiment of a grid element which may be incorporated as a component of a cartridge of a separation unit.
[0077] [0077]FIG. 9 shows an apparatus utilizing the separation unit of FIG. 1.
[0078] [0078]FIG. 10 shows the image, at 280 nm, of the protein bands separated by the iCE280 full-column-imaging capillary isoelectric focusing instrument, from a chicken egg-white sample, used as the starting material for the electrophoretic separation experiments described in Examples 1 to 3. The peaks labeled pI 3.52 and pI 9.61 correspond to dansyl phenylalanine and terbutaline, respectively, used as isoelectric point markers. The egg-white sample was diluted 1:25 with deionized water and filtered prior to analysis. Analysis conditions: instrument: iCE280 full-column imaging capillary IEF system, separation capillary: 5 cm long, 100 micrometer I.D. fused silica, focusing medium: 8% carrier ampholytes for pH 3-10 in aqueous 0.1% methylcellulose solution, focusing time: 5 minutes, applied potential: 3,000 V.
[0079] [0079]FIG. 11 shows the image, at 280 nm, of the protein bands separated by the iCE280 full-column-imaging capillary isoelectric focusing instrument, from aliquots collected at the end of the experiment from the first sample reservoir (bottom panel) and second sample reservoir (top panel) of the electrophoretic apparatus disclosed here and described in Example 1. Separation conditions: anolyte: 60 mL of 80 mM acetic acid, pH=2.9, catholyte: 60 mL 8 mM triethanol amine, pH=9.9, sample: 60 mL aqueous egg-white sample diluted 1:25 in deionized water, separation time: 15 minutes, applied potential: 250 V, first ion-permeable barrier between the first electrolyte chamber and the first sample chamber: pI=4.0 isoelectric membrane, second ion-permeable barrier between the first sample chamber and the second sample chamber: pI=5.0 isoelectric membrane, third ion-permeable barrier between the second sample chamber and the second electrolyte chamber: pI=7.0 isoelectric membrane. The peaks labeled pI 3.52 and pI 9.61 correspond to dansyl phenylalanine and terbutaline, respectively, used as isoelectric point markers. Analysis conditions: instrument: iCE280 full-column imaging IEF system, capillary: 5 cm long, 100 micrometer I.D. fused silica, focusing medium: 8% carrier ampholytes for pH 3-10 in aqueous 0.1% methylcellulose solution, focusing time: 5 minutes, applied potential: 3,000 V.
[0080] [0080]FIG. 12 shows the image, at 280 nm, of the protein bands separated by the iCE280 full-column-imaging capillary isoelectric focusing instrument, from aliquots collected at the end of the experiment described in Example 2 from the first sample reservoir (bottom panel) and the second sample reservoir (top panel) of the electrophoretic apparatus disclosed here. Separation conditions: anolyte: 60 mL 2 mM acetic acid, catholyte: 60 mL 8 mM triethanol amine, sample: 60 mL aqueous egg-white sample diluted 1:25 in distilled water, separation time: 15 minutes, applied potential: 250 V, first ion-permeable barrier between the first electrolyte chamber and the first sample chamber: polyacrylamide membrane with a nominal molecular mass cut-off of 5,000 dalton, second ion-permeable barrier between the first sample chamber and the second sample chamber: pI=5.0 isoelectric membrane, third ion-permeable barrier between the second sample chamber and the second electrolyte chamber: polyacrylamide membrane with a nominal molecular mass cut-off of 5,000 dalton. The peaks labeled pI 3.52 and pI 9.61 correspond to dansyl phenylalanine and terbutaline, respectively, used as isoelectric point markers. Analysis conditions: instrument: iCE280 full-column imaging IEF system, capillary: 5 cm long, 100 micrometer I.D. fused silica, focusing medium: 8% carrier ampholytes for pH 3-10 in aqueous 0.1% methylcellulose solution, focusing time: 5 minutes, applied potential: 3,000 V.
[0081] [0081]FIG. 13 shows the image, at 280 nm, of the protein bands separated by the iCE280 full-column-imaging capillary isoelectric focusing instrument, from aliquots collected at the end of the experiment described in Example 3 from the first sample reservoir (bottom panel) and the second sample reservoir (top panel) of the electrophoretic apparatus disclosed here. Separation conditions: anolyte: 60 mL 2 mM acetic acid, catholyte: 60 mL 8 mM triethanol amine, sample: 60 mL aqueous egg-white sample diluted 1:25 in deionized water, separation time: 15 minutes, applied potential: 250 V, first ion-permeable barrier between the first electrolyte chamber and the first sample chamber: polyacrylamide membrane with a nominal molecular mass cut-off of 1,000,000 dalton, second ion-permeable barrier between the first sample chamber and the second sample chamber: pI=5.0 isoelectric membrane, third ion-permeable barrier between the second sample chamber and the second electrolyte chamber: polyacrylamide membrane with a nominal molecular mass cut-off of 1,000,000 dalton. The peak labeled pI 3.52 corresponds to dansyl phenylalanine, used as isoelectric point marker. Analysis conditions: instrument: iCE280 full-column imaging IEF system, capillary: 5 cm long, 100 micrometer I.D. fused silica, focusing medium: 8% carrier ampholytes for pH 3-10 in aqueous 0.1% methylcellulose solution, focusing time: 5 minutes, applied potential: 3,000 V.
[0082] [0082]FIG. 14 shows the image of an SDS-PAGE gel used to analyze the protein bands present in the aliquots collected from the first and second sample reservoirs of the electrophoretic apparatus disclosed here and described in Example 4 during the isolation of IgG from human plasma. Molecular weight markers (Sigma, St. Louis, Mo., USA) were applied onto Lane 1 , a pharmaceutical-grade IgG preparation used as reference material onto Lane 2 . Samples taken at 0, 10, 20, and 40 minutes respectively from the first sample reservoir were applied onto Lanes 3 , 4 , 5 , and 6 . Samples taken at 0, 10, 20, and 40 minutes respectively from the second sample reservoir were applied onto Lanes 7 , 8 , 9 , and 10 . Separation conditions: anolyte: 2 L 2 mM 5-aminocaproic acid adjusted to pH 4.8 with HCl, also containing 5 mM NaCl, catholyte: 2 L 2 mM MOPSO adjusted to pH 6.8 with NaOH, also containing 5 mM NaCl, sample: 10 mL human plasma sample diluted 1 to 3 with deionized water, separation time: 40 minutes, applied potential: 250 V, first ion-permeable barrier between the first electrolyte chamber and the first sample chamber: polyacrylamide membrane with a nominal molecular mass cut-off of 150,000 dalton, second ion-permeable barrier between the first sample chamber and the second sample chamber: pI=5.8 isoelectric membrane, third ion-permeable barrier between the second sample chamber and the second electrolyte chamber: polyacrylamide membrane with a nominal molecular mass cut-off of 150,000 dalton.
DETAILED DESCRIPTION OF THE INVENTION
[0083] Before describing the preferred embodiments in detail, the principal of operation of the apparatus will first be described. An electric field or potential applied to ions in solution will cause the ions to move toward one of the electrodes. If the ion has a positive charge, it will move toward the negative electrode (cathode). Conversely, a negatively-charged ion will move toward the positive electrode (anode).
[0084] In the apparatus of the present invention, ion-permeable barriers that substantially prevent convective mixing between the adjacent chambers of the apparatus or unit are placed in an electric field and components of the sample are selectively transported through the barriers. The particular ion-permeable barriers used will vary for different applications and generally have characteristic average pore sizes and pore size distributions and/or isoelectric points allowing or substantially preventing passage of different components.
[0085] Having outlined some of the principles of operation of an apparatus in accordance with the present invention, an apparatus itself will be described.
[0086] Referring to FIG. 1, a schematic representation of separation unit 2 is shown for the purpose of illustrating the general functionality of a separation device utilizing the technology of the present invention. Separation unit 2 comprises first electrolyte inlet 4 , and second electrolyte inlet 6 , first sample inlet 8 , and second sample inlet 10 , first electrolyte outlet 12 , and second electrolyte outlet 14 , and first sample outlet 16 and second sample outlet 18 . Between first electrolyte inlet 4 and first outlet 12 is first electrolyte chamber 22 . Likewise, between second electrolyte inlet 6 and second electrolyte outlet 14 is second electrolyte chamber 24 . First sample and second sample inlets and outlets also have connecting chambers. First sample chamber 26 running adjacent to first electrolyte chamber 22 connects first sample inlet 8 to first sample outlet 16 . Similarly, second sample chamber 28 running adjacent to second electrolyte chamber 24 connects second sample inlet 10 to second sample outlet 18 . Ion-permeable barriers 30 and 32 separate electrolyte chambers 22 and 24 from first sample and second sample chambers 26 and 28 , respectively. Between first sample and second sample chambers 26 and 28 is ion-permeable barrier 34 . In one embodiment, when in use, first and second electrolyte 36 and 38 occupy first and second electrolyte chambers 22 and 24 . It should be understood that during operation, first and second electrolyte 36 and 38 , as well as first and second sample 56 and 66 may be stagnant in, or flow through, the respective chambers.
[0087] A schematic diagram of an apparatus utilizing separation unit 2 of FIG. 1 is shown in FIG. 2 for the purpose of illustrating the general functionality of an apparatus utilizing the technology of the present invention. In this purely illustrative example, four chambers (first electrolyte chamber 22 , second electrolyte chamber 24 , first sample chamber 26 , and second sample chamber 28 ) are connected to four flow circuits. First electrolyte flow circuit 40 comprises first electrolyte reservoir 42 , electrolyte tubing 44 , and electrolyte pump 46 . Second electrolyte flow circuit 41 comprises second electrolyte reservoir 43 , electrolyte tubing 45 , and electrolyte pump 47 . In the configuration shown in FIG. 2, electrolyte flow circuits 40 and 41 are running independently from each other so that the composition, temperature, flow rate and volume of first electrolyte 36 and second electrolyte 38 can be suitably adjusted independently of one another.
[0088] In the embodiment shown, first electrolyte 36 flows from first electrolyte reservoir 42 through tubing 44 to pump 46 to first electrolyte chamber 22 . Second electrolyte 24 flows from second electrolyte reservoir 43 through tubing 45 to pump 47 to second electrolyte chamber 24 . First electrolyte 36 flows through inlet 4 and second electrolyte 38 flows through inlet 6 . First electrolyte 36 exits separation unit 2 through outlet 12 and second electrolyte 38 exits separation unit 2 through outlet 14 . After exiting separation unit 2 , electrolytes 36 and 38 flow through tubing 44 and 45 back into respective electrolyte reservoirs 42 and 43 . In one embodiment, electrolytes 36 and 38 are held stagnant in electrolyte chambers 22 and 24 during separation. Electrolytes 36 and 38 can also act as a cooling medium and help prevent a build up of gases generated during electrophoresis.
[0089] First sample flow circuit 48 contains first sample reservoir 50 , tubing 52 and pump 54 . First sample 56 flows from first sample reservoir 50 through tubing 52 to pump 54 , then through inlet 8 into first sample chamber 26 . In one embodiment, the flow directions of first sample 56 and electrolytes 36 and 38 in first sample chamber 26 are opposite. First sample 56 exits separation unit 2 at outlet 16 and flows through tubing 52 , then heat exchanger 68 that passes through second electrolyte reservoir 43 before returning to first sample reservoir 50 through tubing 52 . In an alternative embodiment, heat exchanger 68 passes through first electrolyte reservoir 42 . In another embodiment, the flow directions of first sample 56 and electrolytes 36 and 38 in first sample chamber 26 are the same.
[0090] In addition to components of interest, first sample 56 may contain any suitable electrolyte or additive known in the art as demanded by the procedure, application, or separation being performed to substantially prevent or cause migration of selected components through the ion-permeable barriers. In a preferred embodiment, sample from which constituents are to be removed is placed into first sample reservoir 50 . However, it is understood that in an alternative embodiment, sample from which constituents are to be removed is placed into second sample reservoir 60 .
[0091] Similarly, second sample flow circuit 58 contains second sample reservoir 60 , tubing 62 and pump 64 . Second sample 66 flows from second sample reservoir 60 through tubing 62 to pump 64 , then through inlet 10 into second sample chamber 28 . In one embodiment, the flow directions of second sample 66 and electrolytes 36 and 38 in second sample chamber 28 are opposite. Second sample 66 exits separation unit 2 at outlet 18 and flows through tubing 62 , then heat exchanger 70 that passes through second electrolyte reservoir 43 before returning to second sample reservoir 60 through tubing 62 . In an alternative embodiment, heat exchanger 70 passes through first electrolyte reservoir 43 .
[0092] Second sample 66 may contain any suitable electrolyte or additive known in the art as demanded by the procedure, application, or separation being performed to substantially prevent or cause migration of selected components through the ion-permeable barriers. In a preferred embodiment, sample from which constituents are to be removed is placed into second sample reservoir 60 . However, it is understood that in an alternative embodiment, sample from which constituents are to be removed is placed into first sample reservoir 50 .
[0093] Individually adjustable flow rates of first sample, second sample, first electrolyte and second electrolyte, when employed, can have a significant influence on the separation. Flow rates ranging from zero through several milliliters per minute to several liters per minute are suitable depending on the configuration of the apparatus and the composition, amount and volume of sample processed. In a laboratory scale instrument, individually adjustable flow rates ranging from about 0 mL/minute to about 50,000 mL/minute are used, with the preferred flow rates in the 0 mL/min to about 1,000 mL/minute range. However, higher flow rates are also possible, depending on the pumping means and size of the apparatus. Selection of the individually adjustable flow rates is dependent on the process, the component or components to be transferred, efficiency of transfer, and coupling of the process with other, preceding or following processes.
[0094] Preferably, all tubing 44 , 52 , and 62 is peristaltic tubing that is autoclavable, chemically resistant, and biologically inert. One such tubing is Masterflex® C-FLEX® 50 A tubing. Also, pumps 46 , 47 , 54 and 64 are preferably peristaltic pumps. In the presently preferred embodiment, heat exchangers 68 and 70 are constructed from stainless steel, although other materials known in the art are suitably used. Preferably, heat exchangers 68 and 70 are autoclavable, chemically resistant, biologically inert and capable of facilitating heat exchange.
[0095] Furthermore, it is preferable that first sample flow circuit 48 , second sample flow circuit 58 , first electrolyte flow circuit 40 and second electrolyte flow circuit 41 are completely enclosed to prevent contamination or cross-contamination. In a preferred embodiment, reservoirs 42 , 43 , 50 , and 60 , are completely and individually enclosed from the rest of the apparatus.
[0096] The separation unit further comprises electrodes 88 a and 88 b. Preferably, the respective electrodes are located in the first and second electrolyte chambers and are separated from the first and second sample chambers by ion-permeable barriers.
[0097] Electrodes 88 a and 88 b are suitably standard electrodes or preferably are formed from platinum coated titanium expanded mesh, providing favorable mechanical properties, even distribution of the electric field, long service life and cost efficiency. Electrodes 88 a and 88 b are preferably located relatively close to ion-permeable barriers 30 and 32 providing better utilization of the applied potential and diminished heat generation. A distance of about 0.1 to 6 mm has been found to be suitable for a laboratory scale apparatus. For scaled-up versions, the distance will depend on the number and type of ion-permeable barriers, and the size and volume of the electrolyte and sample chambers. Preferred distances would be in the order of about 0.1 mm to about 10 mm.
[0098] Separation unit 2 also preferably comprises electrode connectors 78 that are used for connecting separation unit 2 to power supply 72 . Preferably, power supply 72 is external to separation unit 2 , however, separation unit 2 is configurable to accept internal power supply 72 . Electrode connectors 78 are preferably autoclavable.
[0099] Separation is achieved when an electric potential is applied to separation unit 2 . Selection of the electric field strength varies depending on the separation. Typically, the electric field strength varies between 1 V/cm to about 5,000 V/cm, preferably between 10 V/cm to 2,000 V/cm and leads to currents of up to about 1 A. It is preferable to maintain the total power consumption of the unit at the minimum, commensurable with the desired separation and production rate.
[0100] In one embodiment, the applied electric potential is periodically stopped and reversed to cause movement of components that have entered the ion-permeable barriers back into at least one of the fluid streams, while substantially not causing re-entry of any components that have entered other fluid streams. In another embodiment, a resting period is utilized. Resting (a period during which fluid flows are maintained but no electric potential is applied) is an optional step that suitably replaces or is included after an optional reversal of the electric potential. Resting is often used for protein-containing samples as an alternative to reversing the potential.
[0101] Separation unit 2 is suitably cooled by various methods known in the art such as ice bricks or cooling coils (external apparatus) placed in one or both electrolyte reservoirs 42 and 43 , or any other suitable means capable of controlling the temperature of electrolytes 36 and 38 . Because both first sample flow circuit 48 and second sample flow circuit 58 pass through either electrolyte reservoir 42 or 43 , heat is exchanged between first and second samples and one or both of first and second electrolytes. Heat exchange tends to maintain the temperature in first sample 56 and second sample 66 at the preferred, usually low levels.
[0102] In another form, there is provided an electrophoresis unit that comprises four chambers (first electrolyte chamber 22 , second electrolyte chamber 24 , first sample chamber 26 , and second sample chamber 28 ). Ion-permeable barriers 30 and 32 separate electrolyte chambers 22 and 24 from first sample and second sample chambers 26 and 28 , respectively. Between first sample and second sample chambers 26 and 28 is ion-permeable barrier 34 . Electrodes are housed in the first and second electrolyte chambers and sample and/or fluid is placed into first sample chamber 26 and second sample chamber 28 . In use, an electric potential is applied between the electrodes and one or more components in the first sample chamber 26 or second sample chamber 28 are caused to move to the other sample chamber or to one of the electrolyte chambers.
[0103] [0103]FIG. 3 is an exploded view of cartridge 100 which is preferably a modular component of separation unit 2 . When configured as a modular unit, cartridge 100 preferably comprises housing 102 for holding in place or encasing the component parts of cartridge 100 . In a presently preferred embodiment, cartridge 100 is generally elongated and has side walls 104 which are generally parallel to one another and the longitudinal axis A of cartridge 100 . The cartridge is suitably generally octagonal, hexagonal, or ovular. In an octagonal configuration, cartridge 100 has three end walls 106 on each side of side walls 104 forming an octagon. However, two end walls on each side 106 are suitably used to form a hexagon, or one curved end wall 106 on each side is suitably used to form a generally ovular shape. Furthermore, end walls 106 are suitably either straight or generally curved.
[0104] Extending around the base of side walls 104 and end walls 106 is a small flange 108 that is generally perpendicular to side walls 104 and end walls 106 and projects inward toward the center of cartridge 100 . Along the exterior of either side walls 104 or end walls 106 is preferably a handle 110 to facilitate placement of cartridge 100 into separation unit 2 . Flange 108 is preferably configured to interact with lower gasket 112 . In a preferred embodiment, lower gasket 112 is generally planar and configured to fit inside walls 104 and 106 of cartridge 100 . In a presently preferred embodiment, lower gasket 112 is made from silicon rubber. Lower gasket 112 may be configured so that it has an aperture 114 extending in an elongated manner through the center of lower gasket 112 . Also extending through and adjacent each end of lower gasket 112 are alignment holes 116 . In a preferred embodiment, alignment holes 116 are circular, forming generally cylindrical channels through lower gasket 112 . However, it is also contemplated that alignment holes 116 are suitably triangular, square, rectangular, hexagonal, octagonal, or similarly shaped.
[0105] Above lower gasket 112 is a generally planar lower ion-permeable barrier 32 . The external shape of ion-permeable barrier 32 is generally the same as that of lower gasket 112 and the interior of cartridge 100 so that ion-permeable barrier 32 is configured to fit inside cartridge 100 . Like lower gasket 112 , ion-permeable barrier 32 preferably has two alignment holes of the same location and configuration as alignment holes 116 in lower gasket 112 . Ion-permeable barrier 32 substantially prevents convective mixing of the contents of first electrolyte chamber 22 and first sample chamber 26 , while permits selective trans-barrier transport of selected constituents upon application of the electric potential.
[0106] In one embodiment, ion-permeable barrier 32 is formed from a membrane with a characteristic average pore size and pore-size distribution. The average pore size and pore size distribution of the membrane is selected to facilitate trans-membrane transport of certain constituents, while substantially preventing trans-membrane transport of other constituents.
[0107] In another embodiment, ion-permeable barrier 32 is an isoelectric ion-permeable barrier, such as an isoelectric membrane that substantially prevents convective mixing of the contents of first electrolyte chamber 22 and first sample chamber 26 , while permits selective trans-barrier transport of selected constituents upon application of the electric potential. Suitable isoelectric membranes can be produced by copolymerizing acrylamide, N,N′-methylene bisacrylamide and appropriate acrylamido derivatives of weak electrolytes yielding isoelectric membranes with pI values in the 2 to 12 range, and average pore sizes that either facilitate or substantially prevent trans-membrane transport of components of selected sizes.
[0108] Above lower ion-permeable barrier 32 is lower grid element 118 that is generally planar and also shaped like lower gasket 112 and the interior of cartridge 100 so that lower grid element 118 is configured to fit inside cartridge 100 . One of the functions of lower grid element 118 is to separate lower ion-permeable barrier 32 from ion-permeable barrier 34 . Another function of lower grid element 118 is to provide a flow path for first sample 56 . Like lower ion-permeable barrier 32 and lower gasket 112 , lower grid element 118 suitably also has alignment holes 116 .
[0109] Above lower grid element 118 is generally planar ion-permeable barrier 34 . The external shape of ion-permeable barrier 34 is generally the same as that of lower gasket 112 and the interior of cartridge 100 so that ion-permeable barrier 34 is configured to fit inside cartridge 100 . Ion-permeable barrier 34 substantially prevents convective mixing of the contents of first sample chamber 26 and second sample chamber 28 , while permits selective trans-barrier transport of selected constituents upon application of the electric potential.
[0110] In one embodiment, ion-permeable barrier 34 is formed from a membrane with a characteristic average pore size and pore-size distribution. The average pore size and pore size distribution of the membrane is selected to facilitate trans-membrane transport of certain constituents, while substantially preventing trans-membrane transport of other constituents.
[0111] In another embodiment, ion-permeable barrier 34 is an isoelectric ion-permeable barrier, such as an isoelectric membrane that substantially prevents convective mixing of the contents of first sample chamber 26 and second sample chamber 28 , while permits selective trans-barrier transport of selected constituents upon application of the electric potential. Suitable isoelectric membranes can be produced by copolymerizing acrylamide, N,N′-methylene bisacrylamide and appropriate acrylamido derivatives of weak electrolytes yielding isoelectric membranes with pI values in the 2 to 12 range, and average pore sizes that either facilitate or substantially prevent trans-membrane transport of components of selected sizes.
[0112] Above ion-permeable barrier 34 are three upper components: upper grid element 120 , upper ion-permeable barrier 38 , and upper gasket 124 . These three components are placed so that upper grid element 120 is immediately above ion-permeable barrier 34 , ion-permeable barrier 38 is immediately above upper grid element 120 , and upper gasket 124 is immediately above ion-permeable barrier 38 . The configuration of the three upper components suitably mirrors that of the lower three components.
[0113] Components below ion-permeable barrier 34 having alignment holes 116 may be connected together with a fastener, which is any type of connector configured to interact with alignment holes 116 and facilitate through flow of first sample 56 . Similarly, components above ion-permeable barrier 34 having alignment holes 116 may be connected together with a fastener, which is any type of connector configured to interact with alignment holes 116 and facilitate through flow of second sample 66 .
[0114] Components of cartridge 100 are suitably held in cartridge 100 by clip 126 . Clip 126 is suitably snap fitted or glued around the top of walls 104 and 106 of cartridge 100 .
[0115] Ion-permeable barrier 38 substantially prevents convective mixing of the contents of second electrolyte chamber 24 and second sample chamber 28 , while permits selective trans-barrier transport of selected constituents upon application of the electric potential.
[0116] In one embodiment, ion-permeable barrier 38 is formed from a membrane with a characteristic average pore size and pore-size distribution. The average pore size and pore size distribution of the membrane is selected to facilitate trans-membrane transport of certain constituents, while substantially preventing trans-membrane transport of other constituents.
[0117] In another embodiment, ion-permeable barrier 38 is an isoelectric ion-permeable barrier, such as an isoelectric membrane that substantially prevents convective mixing of the contents of second electrolyte chamber 24 and second sample chamber 28 , while permits selective trans-barrier transport of selected constituents upon application of the electric potential. Suitable isoelectric membranes can be produced by copolymerizing acrylamide, N,N′-methylene bisacrylamide and appropriate acrylamido derivatives of weak electrolytes yielding isoelectric membranes with pI values in the 2 to 12 range, and average pore sizes that facilitate or substantially prevent trans-membrane transport of components of selected sizes.
[0118] Preferred grid elements 118 and 120 are shown in more detail in FIGS. 4 to 7 . FIG. 4A shows a plan view of a preferred grid element which is incorporated as a component of cartridge 100 for separation unit 2 . An elongate rectangular cut-out portion 128 which incorporates lattice 131 is defined in the center of the grid element. At each end of the grid element, an alignment hole 116 is suitably provided for alignment with the other components of cartridge 100 . Preferably, a triangular channel area 130 having sides and a base, extends and diverges from each alignment hole 116 to cut-out portion 128 . Upstanding ribs 132 , 134 , and 136 (best shown in FIGS. 6 and 7) are defined in channel area 130 . Liquid flowing through hole 116 thus passes along triangular channel area 130 between ribs 132 , 134 , and 136 and into lattice 131 . Ribs 132 , 134 , and 136 direct the flow of liquid from hole 116 so that they help ensure that liquid is evenly distributed along the cross-section of lattice 131 . Ribs 132 , 134 , and 136 also provide support to ion-permeable barrier 34 disposed above or below the grid element.
[0119] Lattice 131 comprises a first array of spaced parallel members 138 extending at an angle to the longitudinal axis of the grid disposed above and integrally formed with a second lower set of spaced parallel members 140 extending at approximately twice the angle of the first array of parallel members 138 to the longitudinal axis of the grid. In the presently preferred embodiment, the first array of parallel members 138 extend at approximately a 45 degree angle from the longitudinal axis and the second array of parallel members 140 extend at approximately 90 degrees to the first array of parallel members 138 , however, other angles are also suitably used.
[0120] Referring to FIG. 4B, the reverse side of the grid element is illustrated. The reverse side is suitably relatively smooth and flat aside from cut-out area 128 and alignment holes 116 . The smooth, flat surface tends to ensure sealing between ion-permeable barriers 32 and grid element 118 , and ion-permeable barrier 38 and grid element 120 , respectively.
[0121] Referring to FIG. 5, the upper and lower surfaces of first and second parallel members 138 and 140 are preferably rounded. When parallel members 138 and 140 are rounded, the absence of any sharp edges help prevent damage to ion-permeable barrier 34 and provide extra support. Lattice 131 evenly distributes the flow of liquid over the surface of ion-permeable barrier 34 . The use of a first set of members 138 disposed above a second set of members 140 tends to ensure that the liquid in a stream is forced to move up and down, changing direction frequently, which helps to encourage mixing of the liquid and tends to inhibit static flow zones.
[0122] The thickness of the grid element is preferably relatively small. In one presently preferred embodiment, exterior areas 144 of the element are 0.8 mm thick. Sealing ridge 142 (also shown in FIGS. 4A and 4B) extends around the periphery of lattice 131 to improve sealing. Ridge 142 is preferably approximately 1.2 mm thick measured from one side of the grid element to the other. The distance between the opposite peaks of lattice elements 138 and 140 measured from one side of the grid to the other is preferably approximately 1 mm. The relatively small thickness of the grid provides several advantages. First, it results in a more even distribution of liquid over ion-permeable barrier 34 and assists in inhibiting its fouling by macromolecules.
[0123] Also, the volume of liquid required is decreased by the use of a relatively thin grid which enables relatively small sample volumes to be used for laboratory-scale separations, a significant advantage over prior art separation devices.
[0124] Finally, if the electric field strength is maintained constant, the use of a relatively thinner grid element enables less electrical power to be deposited into the liquid. If less heat is transferred into the liquid, the temperature of the liquid remains lower. This is advantageous, since high temperatures may destroy both the sample and the desired product.
[0125] [0125]FIG. 8 illustrates grid element 144 for an alternative embodiment of the present invention. Grid element 144 utilizes an ion-permeable barrier having a much larger surface area than that of grid elements 118 and 120 . The principal operation of grid element 144 is suitably generally the same as that of the smaller grid elements although holes 146 through which first sample 56 or second sample 66 are fed are located in two opposite corners of grid 144 and there are many more channels 148 feeding streams from holes 146 to central portion 150 of grid 144 . The cartridge, cartridge casing, and other components are increased in size and shape so as to match that of grid 144 .
[0126] [0126]FIG. 9 is a diagram of a presently preferred embodiment of a separation apparatus 200 for use in accordance with the present invention. The separation apparatus comprises separation unit 2 configured to accept cartridge 100 and clamp 86 . Clamp 86 is used to fix separation unit 2 in place once a component cartridge is placed into separation unit 2 . In the presently preferred embodiment, clamp 86 is constructed from aluminum and is preferably anodized. Clamp 86 is preferably a simple screw clamp unit so that a screw-operated knob may be used to open and close clamp 86 . The separation apparatus shows first sample reservoir 50 , second sample reservoir 60 , and first and second electrolyte reservoirs 42 and 43 in electrolyte compartment 202 .
[0127] In order that the present invention may be more clearly understood, examples of separation methodology are described with reference to the preferred forms of the separation technology as described.
EXAMPLE 1
[0128] An apparatus according to the present invention, shown in FIG. 9, was used to separate the proteins present in chicken egg-white into two fractions. An electrophoresis separation cartridge, shown in FIGS. 3 to 7 , was adapted to be used in the apparatus. The first ion-permeable barrier placed between the first electrolyte chamber and the first sample chamber was a pI=4.0 isoelectric membrane prepared from Immobiline chemicals (Pharmacia, Sweden), acrylamide and N-N′-methylene bis-acrylamide. The second ion-permeable barrier placed between the first sample chamber and the second sample chamber was a pI=5.0 isoelectric membrane prepared from Immobiline chemicals (Pharmacia, Sweden), acrylamide and N-N′-methylene bis-acrylamide. The third ion-permeable barrier placed between the second sample chamber and the second electrolyte chamber was a pI=7.0 isoelectric membrane prepared from Immobiline chemicals (Pharmacia, Sweden), acrylamide and N-N′-methylene bis-acrylamide.
[0129] The first electrolyte reservoir was filled with 60 mL of an 80 mM acetic acid solution, pH 2.9. The second electrolyte reservoir was filled with 60 mL of an 8 mM triethanol amine solution, pH 9.9. The first and second sample reservoirs were filled with 30 mL each of a filtered chicken egg-white solution, diluted with deionized water at a rate of 1 to 25. The anode was placed into the first electrolyte chamber, the cathode into the second electrolyte chamber. The applied potential was 250 V, the separation time was 15 minutes. Aliquots were taken for analysis from the sample reservoirs before separation and at the end of the separation.
[0130] Full-column-imaging capillary isoelectric focusing on an iCE280 instrument (Convergent Bioscience, Toronto, Canada) was used to analyze the egg-white samples. The fused silica separation capillary was 5 cm long, its internal diameter was 100 micrometer. The focusing medium contained 8% carrier ampholytes to cover the pH 3-10 range, in an aqueous, 0.1% methylcellulose solution. Seventy-five microliter of the sample to be analyzed was mixed with 150 microliter of the focusing medium, filled into the capillary and focused for 5 minutes at 3,000 V. Dansyl phenylalanine (pI=3.52) and terbutaline (pI=9.61) were used as pI markers.
[0131] [0131]FIG. 10 shows the results for the egg-white feed sample. The peaks between pixels 650 and 850 correspond to ovalbumin isoforms, those between pixels 1250 and 1350 correspond to ovotransferrin isoforms.
[0132] As a result of the electrophoretic separation, proteins with pI values lower than 5.0, such as ovalbumin (pI=4.7), accumulated in the first sample reservoir, on the anodic side of the pI=5.0 isoelectric membrane (bottom panel in FIG. 11). Proteins with pI values greater than 5.0, such as ovotransferrin (pI=6.1) accumulated in the second sample reservoir, on the cathodic side of the isoelectric membrane (top panel in FIG. 11).
EXAMPLE 2
[0133] The same apparatus as in Example 1 was used to separate the proteins present in chicken egg-white into two fractions. An electrophoresis separation cartridge, shown in FIGS. 3 to 7 , was adapted to be used in the apparatus. The first ion-permeable barrier placed between the first electrolyte chamber and the first sample chamber was a polyacrylamide membrane with a nominal molecular mass cut-off of 5,000 dalton. The ion-permeable barrier between the first sample chamber and the second sample chamber was a pI 5.0 isoelectric membrane prepared from Immobiline chemicals (Pharmacia, Sweden), acrylamide and N-N′-methylene bis-acrylamide as in Example 1. The third ion-permeable barrier placed between the second sample chamber and the second electrolyte chamber was a polyacrylamide membrane with a nominal molecular mass cut-off of 5,000 dalton.
[0134] The first electrolyte reservoir was filled with 60 mL of a 2 mM acetic acid solution, pH 3.8. The second electrolyte reservoir was filled with 60 mL of an 8 mM triethanol amine solution, pH 9.9. The first and second sample reservoirs were filled with 30 mL each of a filtered chicken egg-white solution, diluted with deionized water at a rate of 1 to 25. The anode was placed into the first electrolyte chamber, the cathode into the second electrolyte chamber. The applied potential was 250 V, the separation time was 15 minutes. Aliquots were taken for analysis from the sample reservoirs at the end of the separation.
[0135] Full-column-imaging capillary isoelectric focusing on an iCE280 instrument (Convergent Bioscience, Toronto, Canada) was used to analyze the egg-white samples. The fused silica separation capillary was 5 cm long, its internal diameter was 100 micrometer. The focusing medium contained 8% carrier ampholytes to cover the pH 3-10 range, in an aqueous, 0.1% methylcellulose solution. Seventy-five microliter of the sample to be analyzed was mixed with 150 microliter of the focusing medium, filled into the capillary and focused for 5 minutes at 3,000 V. Dansyl phenylalanine (pI=3.52) and terbutaline (pI=9.61) were used as pI markers.
[0136] As a result of the electrophoretic separation, proteins with pI values lower than 5.0, such as ovalbumin (pI=4.7), accumulated in the first sample reservoir, on the anodic side of the pI=5.0 isoelectric membrane (bottom panel in FIG. 12). Proteins with pI values greater than 5.0, such as ovotransferrin (pI=6.1) accumulated in the second sample reservoir, on the cathodic side of the pI=5.0 isoelectric membrane (top panel in FIG. 12). Neither ovalbumin nor ovotransferrin were lost into the first or second electrolyte chambers despite the fact that the first and third ion-permeable barriers were not isoelectric membranes as in Example 1. At the end of the separation, the solution pH in the first and second sample reservoirs was 4.7 and 6.7, respectively.
EXAMPLE 3
[0137] The same apparatus as in Example 1 was used to separate the proteins present in chicken egg-white into two fractions. The first ion-permeable barrier placed between the first electrolyte chamber and the first sample chamber was a polyacrylamide membrane with a nominal molecular mass cut-off of 1,000,000 dalton. The ion-permeable barrier between the first sample chamber and the second sample chamber was a pI 5.0 isoelectric membrane prepared from Immobiline chemicals (Pharmacia, Sweden), acrylamide and N-N′-methylene bis-acrylamide as in Example 1. The third ion-permeable barrier placed between the second sample chamber and the second electrolyte chamber was a polyacrylamide membrane with a nominal molecular mass cut-off of 1,000,000 dalton.
[0138] The first electrolyte reservoir was filled with 60 mL of a 2 mM acetic acid solution, pH 3.8. The second electrolyte reservoir was filled with 60 mL of an 8 mM triethanol amine solution, pH 9.9. The first and second sample reservoirs were filled with 30 mL each of a filtered chicken egg-white solution, diluted with deionized water at a rate of 1 to 25. The anode was placed into the first electrolyte chamber, the cathode into the second electrolyte chamber. The applied potential was 250 V, the separation time was 15 minutes. Aliquots were taken for analysis from the sample reservoirs at the end of the separation, and analyzed by full-column-imaging capillary isoelectric focusing on an iCE280 instrument.
[0139] As a result of the electrophoretic separation, proteins with pI values lower than 5.0, such as ovalbumin (pI=4.7), accumulated in the first sample reservoir, on the anodic side of the pI=5.0 isoelectric membrane (bottom panel in FIG. 13). Proteins with pI values greater than 5.0, such as ovotransferrin (pI=6.1) accumulated in the second sample reservoir, on the cathodic side of the pI=5.0 isoelectric membrane (top panel of FIG. 13). Neither ovalbumin nor ovotransferrin were lost into the first or second electrolyte chambers despite the fact that the average pore size of the first and third ion-permeable barriers was large enough to permit their passage through these barriers. At the end of the separation, the solution pH in the first and second sample reservoirs was 4.7 and 6.2, respectively.
EXAMPLE 4
[0140] The same apparatus as in Example 1 was used to purify immunoglobulin G (IgG) from human plasma. The first ion-permeable barrier placed between the first electrolyte chamber and the first sample chamber was a polyacrylamide membrane with a nominal molecular mass cut-off of 150,000 dalton. The ion-permeable barrier between the first sample chamber and the second sample chamber was a pI 5.8 isoelectric membrane prepared from Immobiline chemicals (Pharmacia, Sweden), acrylamide and N-N′-methylene bisacrylamide. The third ion-permeable barrier placed between the second sample chamber and the second electrolyte chamber was a polyacrylamide membrane with a nominal molecular mass cut-off of 150,000 dalton.
[0141] The first electrolyte reservoir was filled with 2 L of a 2 mM 5-amino caproic acid solution that also contained 5 mM NaCl, its pH was adjusted to 4.8 with HCl. The second electrolyte reservoir was filled with 2 L of a 2 mM MOPSO solution that also contained 5 mM NaCl, its pH was adjusted to 6.8 with NaOH. The anode was placed into the first electrolyte chamber, the cathode into the second electrolyte chamber. The applied potential was 250 V. Initially, both sample reservoirs were filled with deionized water. Potential was applied for 2 minutes to remove any unpolymerized material from the membranes. After 2 minutes, all reservoirs were emptied, the electrolyte reservoirs were refilled with fresh electrolytes, the sample reservoirs were filled with 15 mL each of human plasma diluted 1 to 3 with deionized water. Potential was applied for 40 minutes. Aliquots were taken for analysis from the sample reservoir chambers at 0, 10, 20, and 40 minutes, respectively.
[0142] [0142]FIG. 14 shows the image of an SDS-PAGE gel used to analyze the protein bands present in the aliquots collected from the first and second sample reservoirs of the electrophoretic apparatus during the isolation of IgG from human plasma. Molecular weight markers (Sigma, St. Louis, Mo., USA) were applied onto Lane 1 , a pharmaceutical-grade IgG preparation used as reference material onto Lane 2 . Samples taken at 0, 10, 20, and 40 minutes respectively from the first sample reservoir were applied onto Lanes 3 , 4 , 5 , and 6 . Samples taken at 0, 10, 20, and 40 minutes respectively from the second sample reservoir were applied onto Lanes 7 , 8 , 9 , and 10 . IgG was purified within 40 minutes.
[0143] These examples indicate that remarkably rapid separation of ampholytic components can be achieved using the apparatus and method disclosed here. The high production rates are attributed to the short electrophoretic migration distances, high electric field strength and good heat dissipation characteristics of the system.
[0144] The invention has been described herein by way of example only. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Other features and aspects of this invention will be appreciated by those skilled in the art upon reading and comprehending this disclosure. Such features, aspects, and expected variations and modifications of the reported results and examples are clearly within the scope of the invention where the invention is limited solely by the scope of the following claims. | An electrophoretic apparatus comprising:
a first electrolyte chamber containing a first electrode;
a second electrolyte chamber containing a second electrode;
a first sample chamber disposed between the first and second electrolyte chambers and proximate to the first electrolyte chamber;
a second sample chamber disposed between the first sample chamber and the second electrolyte;
three ion-permeable barriers separating the first electrolyte chamber, the first sample chamber, the second sample chamber, and the second electrolyte chamber, respectively, wherein the ion-permeable barriers impede convective mixing of the contents in each of the respective chambers;
a first electrolyte reservoir and a second electrolyte reservoir in fluid communication with the first and second electrolyte chambers, respectively;
a first sample reservoir and a second sample reservoir in fluid communication with the first and second sample chambers, respectively;
means adapted for communicating a first electrolyte and a second electrolyte between the respective electrolyte chambers and reservoirs;
means adapted for communicating a first fluid and a second fluid between the respective sample chambers and reservoirs,
wherein at least one of the first and second fluid contains at least a sample, wherein application of an electric potential causes migration of at least one component through at least one of the ion-permeable barriers. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application 61/374,510 filed Aug. 17, 2010, which is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to blood glucose sensing methods and devices.
BACKGROUND OF THE INVENTION
Glucose sensors are of great interest for the medical application of blood glucose sensing. Their optimization (in terms of response time, lifetime, sensitivity and selectivity) is highly necessary to improve the treatment of Diabetes Mellitus, a chronic disease affecting millions of 37 people around the world.
Most studies on this subject have involved the use of enzymes. Although enzymatic detection usually shows good selectivity and high sensitivity, the enzyme is easily denatured during its immobilization process.
Non-enzymatic glucose sensors have been studied to develop an effective enzyme-free sensor; in particular the direct electrochemical oxidation of glucose in alkaline medium was investigated at Cu, Ni, Fe, Pt and Au electrodes. Of these electrodes, platinum was the most promising, but it proved to be extremely non-selective and susceptible to poisoning by various components of blood and other physiological media over extended use.
A different approach to the subject involves performing a cyclic-voltammetric study of glucose oxidation at a gold electrode. Using this approach, the occurrence of a positive current peak was observed during the cathodic sweep, and highlighted a highly linear dependence between current value maxima and glucose concentration. The application of the method in blood glucose sensing, however, has been hindered by the presence of inhibitors; chlorides, amino acids, and human albumin were observed to inhibit the reaction. Among them, chlorides are the most problematic because of their high concentration in the blood, (about 0.1 M) and the difficulty inherent in trying to separate them from glucose.
The present invention advances the art by providing new technology for blood glucose sensing to overcome at least some of these problems.
SUMMARY OF THE INVENTION
The present invention provides a method and device for electrochemically sensing glucose from a sample containing chlorides. A first working electrode (e.g. silver) is used for removing chlorides from the sample. A second working electrode (e.g. gold) is used for absorbing glucose from the sample. A current collector electrode (e.g. platinum) is used for establishing current flow between the first and second working electrodes, while during the removal of chlorides the pH of the sample increases towards basic pH. In one example, the pH increases to about 11.5 or at least 11.5. A sensing device is used for sensing oxidative current peaks caused by the absorption of the glucose. In general, the first and second working electrodes and the current collector electrode are made from non-toxic materials to the human body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-4 show according to exemplary embodiments of the invention cyclic voltammograms (20 mV s-1) ( FIG. 1 ) and pulsed technique (chronoamperometry) of a 50 mM buffer (K2HPO4/KH2PO4) ( FIG. 3 ), pH 11.5 solution at different glucose concentrations: electrolyte, 1 mM, 2 mM, 5 mM, 10 mM, and 20 mM, Calibration curves of ( FIG. 2 ) cyclic voltammetry technique and ( FIG. 4 ) pulsed technique.
FIG. 5 shows a four-step pulsed electrochemical detection schematic according to an exemplary embodiment of the invention.
FIGS. 6-9 show according to exemplary embodiments of the invention cyclic voltammograms (20 mV s-1) ( FIG. 6 ) and ( FIG. 8 ) pulsed technique (chronoamperometry) of a 50 mM buffer (K2HPO4/KH2PO4), pH 7,4 (blood pH) solution at different glucose concentrations: electrolyte, 1 mM, 2 mM, 5 mM 10 mM, and 20 mM. Calibration curves of ( FIG. 7 ) cyclic voltammetry technique and ( FIG. 9 ) pulsed technique.
FIGs. 10-13 show according to an exemplary embodiments of the invention cyclic voltammograms (20 mV s-1) ( FIG. 10 ) and ( FIG. 12 ) pulsed technique (chronoamperometry) of a 50 mM buffer (K2HPO4/KH2PO4) pH 7.4, 100 mM NaCl solution at different glucose concentrations after chloride removal step:
electrolyte, 1 mM, 2 mM,) 5 mM, 10 mM, and 20 mM Calibration curves of ( FIG. 11 ) cyclic voltammetry technique and ( FIG. 13 ) pulsed technique.
FIG. 14 shows according to exemplary embodiment of the invention a schematic of a blood glucose sensing device 1400 including an Ag electrode, an Au electrode, a Pt electrode and a sensor for sensing current.
DETAILED DESCRIPTION
To overcome at least some of the problems of chlorides in blood samples, the mechanism of glucose oxidation at gold electrodes was investigated, The glucose molecule is first electrochemically adsorbed at the surface of the electrode by dehydrogenation (peak I in FIG. 1 ). The dehydrogenated molecule can be transformed to gluconate either by direct oxidation or through a δ-gluconolactone intermediate step. At room temperature these two processes cannot be distinguished (peak II in FIG, 1 ). At higher potentials, the gold surface is oxidized to gold hydroxide (peak III in FIG. 1 ), which is inactive towards glucose electro-oxidation. During the cathodic scan, gold hydroxide is reduced, and therefore glucose can be readsorbed and oxidized, generating the oxidative peak in the cathodic scan (peak IV in FIG. 1 ).
Chloride ions inhibit the formation of the “sensing peak” in two ways:
1) In the presence of chlorides gold gets oxidised to gold tetrachloroaurate instead of forming the hydroxide (reaction III). 2) Chlorides, adsorbing at gold active sites, inhibit glucose oxidative adsorption (reaction I), first and key step of the oxidation mechanism.
In the present invention, a further solution to this problem is provided which involves a three electrodes setup, and a four-steps pulsed electrochemical detection technique (see FIG. 5 ).
In one example, D(+)-Glucose anhydrous, sodium chloride, potassium phosphate dibasic, potassium phosphate monobasic and silver gauze (80 mesh 0.115 mm diameter wire, 99.9% 2×2 cm) were used (e.g. from Sigma Aldrich). Gold pin electrode (Surface Area 0.0314 cm2) and platinum counter electrode were also used (e.g. from Amel Electrochemistry). The electrochemical characterization was carried out using a BioLogic VMP3 potentiostat-galvanostat multichannel equipped with EIS board, the experimental setup of the device and method has a total of four electrodes (see FIG. 5 ):
Two working electrodes (WE): a silver gauze for chlorides removal-pH increase ( FIG. 5 , steps 1 and 4) and a gold pin for glucose sensing ( FIG. 5 , steps 2 and 3). Their connection with the potentiostat could be switched manually. Nevertheless, in this example, they were both present in the solution during the entire experiment. A platinum counter electrode (CE). A double junction Ag|AgCl|KCl (3.5 M) reference electrode (RE).
Before each experiment, the gold pin electrode surface has been activated and stabilized in 0.1 M KOH by CV scans at 100 mV s-1 between −0.7 and 0.8 V vs. RE until stable voltammograms have been observed. All the measurements have been performed at room temperature under nitrogen atmosphere.
FIG. 1 shows cyclic voltammetries performed in a 50 mM buffer (K2HPO4/K3PO4), of pH 11.5 at different glucose concentrations ranging from 1 to 20 mM, corresponding to a 18-360 mg/dl glycemia range. According to our studies, these are the best operating conditions for optimal sensitivity of the return peak.
In these conditions ( FIG. 2 ) it is evident that a linear relationship exists between the cathodic oxidative peak current density and glucose concentration in the investigated range. The preparation of the circuits to perform a CV and analyze the peak current value in a real application is complex, therefore the next step was to develop and optimize a pulsed two-step electrochemical technique, which would be easier to realize in practical applications. In the first step (0.8 V vs. RE, 40s), gold hydroxide is generated, followed by the second step (0.15V vs. RE, 15s), where gold hydroxide is reduced and glucose sensing performed. Potential and step time have been optimized for the operating conditions. In FIG. 3 , it is shown that one of the 10 cycles performed for each glucose concentration to evaluate the reproducibility of the measurement. Even with this type of measurement, we saw a highly linear relationship between glucose concentration and current density as reported in FIG. 4 . In this case the stationary value of current vs. glucose concentration is reported instead of the peak current value, since it is more reproducible and easier to measure in a real device application.
After proving the efficiency of the pulsed technique at pH 11.5, the next step was to test it at pH 7.4, (blood pH), while keeping all other parameters constant.
In FIG. 6 the cyclic voltammograms in the same glucose concentration range are shown. The current output is lower with respect to the previous conditions, and therefore the sensitivity on the return peak is also lower. Moreover, ( FIG. 7 ) at higher glucose concentrations the response is not linear. This is due to the lower OH-concentration that limits the gluconate formation, as previously supra.
Despite this, the pulsed technique has been tested in these conditions ( FIG. 8 ). Changing the pH requires a modification in the steps potentials, as both the gold hydroxide and return peak potentials are pH dependent. In this case, the gold hydroxide is generated at 0.9V vs. RE (40s) and the subsequent reduction/sensing step performed at 0.3 V (15 s). Thus it was demonstrated that it is possible to apply the pulsed method at blood pH, though the sensitivity and linearity range are diminished ( FIG. 9 ).
The following step was to test the method in the presence of 100 mM potassium chloride at pH 7.4 buffered with 50 mM K2HPO4/144 KH2PO4, thus partially recreating the physiological conditions of human blood. In this case, in both CV and the pulsed technique, instead of the oxidative peak in the cathodic scan, a reduction process is observed. In the presence of chlorides, it is known that gold is oxidized to AuCl-4, a reaction that takes place at a lower potential than Au(OH)3 formation. In the cathodic scan the gold tetrachloroaurate, previously generated in the anodic scan, is reduced.
However, upon analyzing the Pourbaix diagram of gold in the presence of chlorides, it is evident that at pH values higher than 9, gold hydroxide is the most stable phase, even in the presence of up to a 2 M chloride concentration. Therefore, it is not necessary to remove all the chlorides from the solution to perform the sensing step, but it is enough to locally increase the pH to over 9. On the basis of these considerations, a four-step, three electrode (silver gauze, gold pin and platinum counter electrode) measurement has been performed. The optimized operating conditions are reported in FIG. 5 .
The first step is a chronopotentionietry step, (I=10 mA) in which a silver gauze working electrode is oxidized to silver chloride, while water is reduced at the platinum counter electrode. In the overall reaction, for every chloride ion removed, a hydroxide ion is generated; therefore to shift the solution pH from 7.4 to 11.5 it is necessary to remove only 10% of the chlorides present in the solution. Thus the charge flow needs to be controlled, and it depends on the volume of solution employed (in the exemplary case we used 15 ml of solution and the charge was limited to 5 mC).
The second step corresponds to the first step of the pulsed technique described supra, in which the gold pin electrode surface is oxidized to gold hydroxide (0.7 V vs. RE, 40 s) and subsequently reduced (0.3 V vs. RE, 15 s) in the third step: once the gold surface is regenerated, glucose can be re-adsorbed and an oxidative peak is generated. In this case, both the peaks observed in the CV, ( FIG. 10 ) as well as the steady state current in the pulsed technique, ( FIG. 11 ) show a very strong linear dependence on glucose concentration in the investigated range, coupled with high sensitivity. In the last (fourth) step, the silver electrode (partially covered with silver chloride from step 1) is reduced and regenerated, ready for the next sensing.
In the present invention, we identified a device and method for electrochemically sensing glucose in the presence of chlorides. These electrochemical devices and methods grant higher accuracies and sensitivities than enzymatic methods. All the materials employed (silver, platinum and gold) are fully compatible with in vivo sensing applications.
The examples reported have been tested in 15 ml of solution, which necessitates long time steps. The invention is not limited to the implementation of a miniaturized device which reduces each step time signitifantly. | An oxidative peak in a cathodic scan is observed in the cyclic voltammetry of glucose at gold electrodes, its peak current density being proportional to glucose concentration in a wide potential range. The application of this phenomenon in blood glucose sensing has been hindered by the presence of inhibitors: the most problematic are chlorides due to their high concentration and difficult separation from glucose. The present invention provides a solution to this problem involving a three electrode, four step pulsed electrochemical detection technique. | 6 |
PRIORITY INFORMATION
[0001] This application claims benefit of priority from U.S. Provisional Patent Application No. 60/368,054, filed Mar. 27, 2002.
FIELD OF THE INVENTION
[0002] This invention relates to a sheath for integrating sewer hose and television (TV) cable lines for sewer cleaning and inspection, and is more particularly directed to such a sheath which can encapsulate both a jet hose and a TV camera cable useful in detecting a blockage, and cleaning a clogged sewer from a mobile truck or trailer sewer cleaning machine.
BACKGROUND
[0003] Mobile truck and trailer sewer cleaning machines have become popular for use by municipalities and others. These machines include pumping mechanism connecting a fluid supply for delivering water and other fluids under jet pressure through one or more hoses wound on a reel. The hose may be wound onto or unwound from the reel to thread the hose into or withdraw it from a sewer line. This hose may have, connected to its remote end, a variety of cutting implements useful in clearing clogged sewer lines. It has also become important to provide means for viewing the interior of the sewer line as the jet hose travels through it. The viewing means is typically a TV camera carried by a skid on the remote end of the hose line, and a cable which may be extended into the sewer line as the hose is advanced. These actions are preferably managed from a control panel on the sewer cleaning machine. Typical jet sewer cleaning machines usable in these procedures are shown in O'Brien et al U.S. Pat. No. 5,636,648, Prange U.S. Pat. No. 4,838,302, and Schmidt Jr. et al U.S. Pat. No. 4,896,686.
[0004] The TV camera in such an operation is often used to locate trouble in the sewer line, such as a clogged location or a broken and misaligned sewer pipe. Usually, the hose is used to force the camera carrier through the sewer line by fluid jet pressure. Sometimes, in doing so, it is necessary to cleanse the sewer line of caked mud or vegetation in order to view a suspected trouble spot. The jet fluid hose and the TV cable are usually introduced into the sewer line in tandem. In conventional systems, the TV cable and the jet hose are usually separate and are fed into the sewer separately—but sometime side by side. In such a maneuver, the operator must be particularly careful not to tangle the TV cable and jet hose lines, which are payed out remote from the operator's location and are very difficult to untangle. The effort to untangle them may result in substantial risk to the equipment and personnel when such a tangle of the cable and hose lines occurs. Usually, this effort in feeding the jet hose and TV cable lines requires substantial skill on the part of the operator who must synchronize the entries and movements of the lines. To minimize such a problem, the operator may feed the TV cable and the jet hose lines into the sewer separately and to a selected point, one line at a time. Such an action may at least double the time required to locate and cleanse a clogged area, particularly where the sewer line is uneven or clogged with debris or vegetation.
[0005] In the prior art, others have attempted to secure the TV camera to an end of the jet hose line. For example, see Van Norman U.S. Pat. No. 4,107,738 and McLeod et at U.S. Pat. No. 6,111,600. However, in these arrangements, there still is the probability that the TV cable line and the jet hose line will be snagged on a root or broken pipe, or turn relative to one another and thus create a tangle of the lines which is difficult to remove. Others have tried to join the TV cable line and the jet hose line within a metallic coil spring arrangement, as in Irwin U.S. Pat. No. 5,996,159. However, such springs have been found inadequately flexible and too stiff to make all the necessary turns in a sewer line. Accordingly, they require a beefed up mechanism including a special swivel assembly or the like to drive and manipulate them. Additionally, if a coil of such a spring becomes hung up in the sewer line or broken out, there is a danger that the jet hose or the TV cable line or camera will be damaged, and become inoperable. There is also the danger that the coil spring will not pay out smoothly, and may hang up on its feed mechanism, or that the metallic line will become corroded, oxidized or inoperable. There may also be a problem where the metallic coil spring is conductive, and has the capacity to damage or short out the cable line if it contacts an open circuit.
[0006] Normally, when the TV cable and jet hose lines are separate, they terminate at the machine separately, too. Thus, the operator is often required to view two control areas, one for the TV cable monitor and another for the jet hose, sometimes requiring added personnel to adequately supervise the inspection and cleansing jobs, and increasing the cost of the cleaning and inspection job. Additionally, in cold or stormy weather, the operator faces an uncomfortable task of threading out or winding in the line for a longer time under difficult circumstances.
SUMMARY, OBJECTS AND ADVANTAGES OF THE INVENTION
[0007] The present invention provides a rubber-like, non-corrosive, non-metallic, smooth-skin sheath, which may be integral with and encapsulates both the jet hose and TV cable lines. In an embodiment, such a sheath is fabricated from tough, flexible rubber or plastic polymers, to protect both the jet hose and TV cable lines, and to keep them separated. The sheath, with the jet hose and TV cable lines enclosed therein, is wound on a typical reel of a sewer jet cleaning machine. At the hub of the reel, there may be exit connections for both the TV cable and jet hose lines. The termination of the TV cable line will connect to a TV monitor and controls, and the termination of the jet hose line will connect to a fluid supply and pump unit for delivering fluid through that line under pressure. In another embodiment, the sheath is coated with a silicone material to make it slick to slide easily in the sewer line, so the sheath can travel through the sewer line under the least possible resistance. The forward end of the jet hose line may have connected to it a root cutter or other tool, which may be manipulated by water pressure or other means. The forward end of the TV cable will be connected to a TV camera, usually fit with a lamp. These implements may be connected conventionally to the jet hose and TV cable line, respectively.
[0008] The sheath can have many cross-sectional configurations, including circle, oval, square, etc. In one embodiment, the sheath has a cross section which is wider than it is high, has chamfered edges, and is biased to roll on the reel, so that it will pay out without damage to the TV cable or jet hose lines, and will lay flat on the sewer line and properly wind up, without hanging up in the sewer or on the reel. Also, the sheath is solid and dense, to protect the enclosed lines. Because of the juxtaposition of the lines, the control panel may contain controls for the jet hose and the TV cable, thus controlling pay-out, fluid pressure, reel operation, and other operations for the jet hose, as well as viewing of the monitor necessary to see the interior and condition of the sewer line.
[0009] Where it is desirable to provide a jet hose line separate from the sheathed integrated jet hose and TV cable lines, in order to provide another jet cleaning source, which may be of another size (to accommodate a larger or smaller sewer line), or to cleanse the line in advance of or after TV surveillance of the sewer line, another hose reel and hose can be mounted on the same reel axle and separately controlled.
[0010] The arrangement of the sheath in the present invention also permits connection of the TV camera to the TV cable line other than at the end of the jet hose, by merely connecting to the TV cable line at an intermediate point with conventional connection members. Thus, the TV camera does not necessarily have to pay-out at the same point as the jet stream is delivered in the sewer line.
[0011] Additionally, if the sheath become cut or damaged, it can be inserted into a repair fixture, where rubber-like polymer material can be poured into the fixture to bind the sheath, and set up to repair the sheath. Such a fixture will have the configuration of the sheath exterior. Many conventional plastic polymers can be used in making such a repair, for example polyurethane or other conventional cold curing polymers.
[0012] This invention provides a sheath for integrating sewer hose and TV cable of the character described herein. It also provides a unitary sewer hose and TV cable. One embodiment provides a sheath for integrating sewer hose and TV cable which is dense and flexible. Another embodiment provides a sheath for integrating sewer hose and TV cable which has a cross-section wider than it is high, and is adapted for unwinding on a hose reel of a mobile sewer cleaning machine to enter a sewer line, and for winding on the hose reel for removing it from the sewer line. A further embodiment provides a sheathed integrated sewer hose and TV cable arrangement which can accommodate one or more additional hose lines on the same or a related reel axle. A further embodiment provides a smooth skin non-corrosive, non-conductive rubber-like sheath which can integrally encapsulate a jet hose and TV cable for the purposes described herein. Another embodiment provides a sheath integrating jet hose and TV cable lines which is easy to repair without disassembling the sheath and lines from the reel or machine. Another embodiment provides a sheathed integrated sewer hose and TV cable arrangement which is easy, inexpensive, efficient and effective to manufacture, and which is simple and efficient and expedient in use.
[0013] These and other objects and advantages will become more apparent as this description proceeds, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a perspective view of a typical mobile trailer sewer cleaning machine having a sheathed integrated jet hose and TV cable lines and controls.
[0015] [0015]FIG. 2 is a perspective view of a reel upon which is wound a sheathed integrated jet hose and TV cable lines embodying the invention, and control panels for the jet hose and TV cable lines.
[0016] [0016]FIG. 3 is a longitudinal view of a length of the sheathed integrated jet hose and TV cable lines, partially broken away in section.
[0017] [0017]FIG. 4 is a cross-sectional view of the sheathed integrated jet hose and TV cable lines taken on line 4 - 4 of FIG. 3.
[0018] [0018]FIG. 5 is a perspective view of the exiting line of TV cable terminating at a reel hub and entering and connected to a TV monitor assembly.
[0019] [0019]FIG. 6 is a perspective view of an alternative arrangement of the mobile trailer sewer cleaning machine having two reels, one of which may have a hose carrying a TV camera and the other used for providing pressurize water for cleaning the sewer.
[0020] [0020]FIG. 7 is a perspective view of a skid carrying a TV camera and connected to the novel hose sheath embodying the present invention.
DETAILED DESCRIPTION
[0021] The invention is described by the following illustrations. It should be recognized that variations based on the inventive features disclosed herein are within the skill of the ordinary artisan, and that the scope of the invention should not be limited by the examples. To properly determine the scope of the invention, an interested party should consider the claims herein, and any equivalent thereof. In addition, all citations herein are incorporated by reference.
[0022] As shown in FIGS. 1 and 2, a typical jet hose sewer cleaning machine consists of a trailer body 10 on which may be mounted a reel 11 carried by a frame 12 having wound thereon a length of a tubular structure or line comprising an outer sheath 13 which encapsulates a fluid jet hose 33 and TV cable 34 . The reel frame 12 may be carried by a telescoping platform 14 , and may include a jet hose control panel 15 , having instruments such as an ignition switch 16 , choke 17 , throttle 18 , tachometer 19 , oil pressure gauge, voltmeter, water temperature gauge, circuit breaker, and possibly other instruments. Another control panel 24 , which may also be mounted on the reel frame 12 , is provided for the TV cable and monitor, which may comprise TV and monitor switches 25 and 26 , respectively, and a TV monitor screen 27 , as well as conventional TV controls 28 , all of which are available for viewing by a single operator located at the control panels. This reel-frame assembly 11 - 12 of the trailer 10 may have control handles 29 and 30 for the jet hose and TV cable mechanism, respectively. A fluid line 31 enters the interior of the trailer 10 connecting the jet hose through a high pressure pump to a source of fluid (not shown).
[0023] When in operation, the trailer 10 , with its warning beacon 32 operating, is positioned over a sewer manhole M and the reel 11 is rotated in the frame 12 to thread the sheath 13 into the manhole of a sewer S and into a selected one of several sewer lines L. Should the operator wish to use a stream of fluid from the hose jet or operate the TV camera, he may do so, using the features of the invention hereinafter described.
[0024] The sheath 13 wound on the reel contains integrally therein a length of heavy duty jet hose 33 and a TV cable 34 line. In an embodiment, this sheath 13 is fabricated from heavy, dense rubber-like plastic and may be coated with a silicone material to make it slick. In another embodiment, the sheath 13 is oriented so that its width 35 is greater than its height 36 , thus making it biased to a flat position in the sewer line L. In a preferred embodiment, the sheath 13 has chamfered edges 37 , so that it will not hang up on obstacles, such as a broken sewer pipe or tree root or other obstacle, in the sewer line L. A conventional TV camera 60 (see FIG. 7) is connected to the end of the TV cable line 34 at the end of the sheath 13 , or at any point along its length, by merely cutting the wall of the sheath to gain access to the TV cable.
[0025] The reel 11 may be constructed with movable side plates 38 a and 38 b , or there may be more than one reel mounted on the frame, such as additional reel 42 (see FIG. 6), so that they may be in position to accommodate more than one length of hose, perhaps of different sizes, or another sheath 13 . In FIG. 2 the reel plates 38 a and 38 b may be spaced apart to accept a length of jet sewer cleaning hose (not shown). These plates 38 connect to a reel hub 39 (FIG. 5), though which connections may be made to the fluid lines (not shown) or to a TV monitor 27 which may be mounted on the control panel 24 or elsewhere on the machine. The TV cable line 34 may exit the reel hub 39 and terminate in the control panel 24 , as shown in FIG. 5.
[0026] As shown in FIG. 6, an alternative trailer 40 may include the novel sheath 13 and its associated reel 11 previously described in association with a typical water hose 41 and its associated reel 42 , in situations where it is desired to deliver a large volume of jet pressured water to the target sewer or if sewer cleaning is to proceed without monitoring by a described TV camera arrangement.
[0027] An embodiment with a TV camera skid 50 is shown in FIG. 7. A preferred embodiment of this skid 50 has multiple wheels 51 which span the sewer line, making it easy to maneuver the TV camera 60 through the sewer line. This TV camera 60 is supported on a frame 52 , which carries the wheels 51 , and has a tube 53 for mounting the TV camera. The frame 52 also has connections for receiving the fluid line 33 and the TV cable line 34 when they exit the sheath adjacent the TV camera 60 . Jet fluid exiting from the fluid line 33 propels the skid 50 forward in the sewer line.
[0028] Should the sheath 13 be damaged from cuts, wear or otherwise, it can be repaired by merely placing the damaged areas within a fixture approximating the exterior width and height dimensions of the sheath and pouring a liquid polymer into the fixture to set up and bind with the damaged sheath, thus making the sheath useful again.
[0029] The sheath may consist of a length of jet hose 33 and a length of television cable 34 appropriately joined together by fusing or other means so that they may be wound and unwound from and upon rotation of a single rotationable reel 11 , as to prevent the lengths from being tangled with one another during their entry and manipulation into and removal from a sewer line.
[0030] While a preferred embodiment of the invention has been shown and described in considerable detail, it should be understood that the structural elements of the invention may be varied, and it is not desired that the invention should be limited to the exact structure described. | A novel tubular rubber-like non-corrosive sheath, which may be wound on a reel of a mobile sewer cleaning and inspection machine for entry into a sewer line, which encapsulates or joins together a length of jet hose and a length of television cable for a television camera. The invention also includes a novel skid mounting a television camera at the end of a sheath, which carries a television camera, and which in arranged in a position to permit fluid exiting the jet hose to propel the skid in a sewer line. | 4 |
FIELD OF THE INVENTION
The present invention pertains generally to an ergonomic chair that improves strength, endurance, and flexibility of the user. The present invention is more particularly, though not exclusively, useful as a chair which is designed to avoid work station related back pain and neck pain for people sitting for a long period of time at work by adopting a dynamic hemispherical seat to allow the harmony of the spine, muscles, ligaments, and discs. The present invention also provides an ergonomic chair that can be used as an office stretch GYM ball, when a back support and folding hinges are folded under the chair.
BACKGROUND OF THE INVENTION
Recent studies show that many cases of back pain and neck pain in a modern society are related to work stations that require people to sit for an extended period of time, since the human spine is not originally designed to sit for more than 10 to 15 minutes. Sitting for a long period of time puts a lot of strain on discs of the lumbar, or lower back, and the pressure on the discs increases dramatically when people lean forward while sitting, to write or use a computer. This bad posture exerts uneven forces to the intervertebral discs that lie between each of the vertebral bodies, and results in a loss of anterior longitudinal ligaments.
It has been known that a majority of back pains are caused by strains and/or sprains of the lordotic curve consisting of muscles, ligaments and tendons. People with jobs that require sitting at a work station for a long period of time tend to have their muscles become lax and lose the ability to support the spine correctly, due to the stress on the cervical spine. As a result, the ligaments and tendons in such people can also lose the ability to function properly. Unfortunately, sitting on a regular chair at work does not usually support the lordotic curve, and thus, various types of ergonomic chairs have been developed.
Ergonomic seating units adopting a gas-filled ball or a balloon which allows lateral movement and deformation when a user sits on the chair have been invented and widely used. These ergonomic chairs may be helpful to adjust sitting comfort, balance, and endurance. However, people on the ball-shaped chairs tend to forget about their sitting posture during work and currently available ergonomic chairs include seats which deform to accommodate the user's poor posture. Thus, currently available ergonomic chairs are not able to properly maintain the user's posture upright. The currently available ergonomic chairs can support the user's back only when the user leans on the chair, but not when the user leans forward towards the desk to write or type on the computer.
In light of the above, it would be advantageous to provide an ergonomic chair that can subconsciously adjust the user's position for a better posture as the user sits, by maintaining the spine of the user in the same alignment as when the user stands. It would also be advantageous to provide an ergonomic chair with a seat which does not allow any deformation on the seat. It would further be advantageous to provide an ergonomic chair that helps the nerve system to transmit 100% of the signals to the user's organs for a better internal function, through the correct posture. In addition, it would be advantageous to provide an ergonomic chair that can be used as a stretch GYM ball at the office, and which is simple to use, and comparatively cost effective.
SUMMARY OF THE INVENTION
The present invention includes an ergonomic chair that improves strength, endurance, and flexibility of the user. The present invention is useful for people who sit for an extended period of time at work and minimizes work station related back pain and neck pain. The present invention incorporates a hemispherical seat which can be locked in position and comprises a fixed inner hemisphere, a movable outer hemisphere, and a circumferential shroud. The inner hemisphere is fixed to a support pole which absorbs the load from the user, and a movable cuter hemisphere of the hemispherical seat is positioned over the fixed inner hemisphere and attached to tension springs which maintain the movable outer hemisphere in place. The movable outer hemisphere may be equipped with elastic ends or springs having hydraulic or pneumatic resistance devices, forming a rigid frame for a balanced movement of the outer hemisphere. The rigid outer hemispherical of the present invention does not allow deformation on the hemispherical seat when a user sits on the chair and the present invention keeps the spine of the user in the same alignment as when the user stands, further improving the internal function of the user's organs. Furthermore, the present invention can also be used as an office stretch GYM ball, when the folding hinges and a back support are folded and slid in under the chair.
BRIEF DESCRIPTION OF THE DRAWING
The nature, objects, and advantages of the present invention will become more apparent to those skilled in the art after considering the following detailed description in connection with the accompanying drawings, in which like reference numerals designate like parts throughout, and wherein:
FIG. 1 is a perspective view of the Ergonomic Göbelek Chair of the present invention, showing a hemispherical seat, a pair of folding hinges having a pair of armrest supports, a back support, a base support, and a pedestal;
FIG. 2 is a vertical cross-sectional view of the Ergonomic Göbelek Chair of the present invention, consisting of multiple layers of hemispheres and a shroud connected through tracks of ball bearings or a sheet of soft and breathable foam, wherein an inner hemisphere is attached to the support pole, an outer hemisphere attached to a series of tension springs is freely movable while maintaining its orientation over the inner hemisphere and also can be locked in position, and a shroud encircles the outer hemisphere and is equipped with a pair of folding hinges to support a pair of armrests;
FIG. 3 is a perspective view of a movable outer hemisphere equipped with resistance elements, such as elastic ends or springs, and hydraulic or pneumatic resistance devices at its bottom, forming a rigid frame structure to the hemispherical seat;
FIG. 4 is a bottom view of a movable outer hemisphere equipped with resistance elements, such as elastic ends or springs and hydraulic or pneumatic resistance devices;
FIG. 5 is a top view of a fixed inner hemisphere permanently equipped with ball bearings placed on the circular tracks;
FIG. 6 is a top view of a fixed inner hemisphere permanently equipped with ball bearings, with an alternative placement on the tracks in a radial arrangement;
FIG. 7 is a top view of a fixed inner hemisphere with grease bearings placed on the circular tracks;
FIG. 8 is a top view of a fixed inner hemisphere with polymer bearings consisting of a circular strip on the top of the inner hemisphere, and multiple strips attached to the circular strip and extended radially therefrom;
FIG. 9 is a detailed vertical cross-sectional view depicting the inner hemisphere, bearing layer, and outer hemisphere and a shroud connected through the ball bearings with rows of balls for a fixed inner hemisphere and a movable outer hemisphere, and a soft and breathable foam for a movable outer hemisphere and a shroud;
FIG. 10 is a detailed top view of the horizontally cut shroud, where a top of a soft and breathable foam is visible through the center circular cutout of the shroud;
FIG. 11 is a cross-sectional view of the Ergonomic Göbelek Chair of the present invention depicting an installment of a bottom cover to the base frame of a shroud, with the support pole inserted through the circular opening on the bottom cover;
FIG. 12 is a detailed cross-sectional view of the left-end edge of the Ergonomic Göbelek Chair of the present invention shown in FIG. 11 , when the outer edge of a shroud is installed to a bottom cover;
FIG. 13A is a cross-sectional view of the Ergonomic Göbelek Chair of the present invention with a support ring attached to fix the locking system to the support pole;
FIG. 13B is a top view of the locking system in the Ergonomic Göbelek Chair of the present invention attached to the support ring as installed on the support pole;
FIG. 14A is a detailed cross-sectional view of the left-end edge of the movable outer hemisphere equipped with a locking system extending underneath the movable outer hemisphere to lock the hemisphere in place to prevent movement;
FIG. 14B is a detailed cross-sectional view of the locking system attached and fixed to the support pole through the support ring, illustrating bores extending radially outwards through the support ring and corresponding to holes formed in the support pole for such attachment;
FIG. 15A is a diagrammatic view of the locking system in the Ergonomic Göbelek Chair of the present in an unlocked configuration;
FIG. 15B is a top view of the locking system in the Ergonomic Göbelek Chair of the present invention in the unlocked configuration, illustrating the locking bar shafts pulled back into the tubing posts;
FIG. 16A is a diagrammatic view of the locking system in the Ergonomic Göbelek Chair of the present invention in a locked configuration;
FIG. 16B is a top view of the locking system in the Ergonomic Göbelek Chair of the present invention in a locked configuration, illustrating the locking bar shafts extended underneath the movable outer hemisphere, locking the chair from tilting;
FIG. 17 is a diagrammatic view of the Ergonomic Göbelek Chair of the present invention when it is equipped with a base support having a shock absorber, a height adjustment lever, and a pedestal;
FIG. 18 is a back view of the Ergonomic Göbelek Chair of the present invention when it is equipped with an alternative pedestal having a heavy base and side wheels for easier movement of the chair when tilted;
FIG. 19 is a diagrammatic view of the Ergonomic Göbelek Chair of the present invention equipped with a pedestal having wheels and a back support when the back support is positioned beneath the chair such that the Ergonomic Göbelek Chair of the present invention is used as an office stretch GYM ball;
FIG. 20 is a partial vertical cross-sectional view of an alternative embodiment of the Ergonomic Göbelek Chair of the present invention when it is equipped with a shroud and a movable outer hemisphere which sits on five (5) single bearings;
FIG. 21 is a side view of an alternative embodiment of the Ergonomic Göbelek Chair of the present invention equipped with ergonomic armrests installed with springs inside for easier movement of the armrests depending on the users need; and
FIG. 22 is a diagrammatic view of the alternative embodiment of the Ergonomic Göbelek Chair of the present invention when the back support and the armrests are positioned beneath the chair such that the Ergonomic Göbelek Chair of the present invention is used as an office stretch GYM ball.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIG. 1 , a perspective view of a preferred embodiment of the Ergonomic Göbelek Chair of the present invention is depicted and generally designated 100 . The preferred embodiment 100 of the Ergonomic Göbelek Chair of the present invention depicted in FIG. 1 shows a hemispherical seat consisting of multiple layers of hemispheres and a shroud 118 including a sheet of soft and breathable foam 110 attached on top of a movable outer hemisphere 108 (not shown) for the user's comfort while sitting on the chair, a pair of folding hinges 126 equipped with a pair of armrest supports 127 , a back support 132 , a base support 130 and a pedestal 134 . A back support 132 is equipped with a lumbar cushion 133 for the user's comfort.
Now referring to FIG. 2 , a vertical cross-sectional view of a preferred embodiment of the Ergonomic Göbelek Chair of the present invention is depicted. The preferred embodiment 100 of the Ergonomic Göbelek Chair of the present invention consists of multiple layers of hemispheres (a fixed inner hemisphere 102 and a movable outer hemisphere 108 ) and a shroud 118 connected through tracks of ball bearings 106 and a sheet of soft and breathable foam 110 . The preferred embodiment 100 of the present invention further comprises a support pole 104 , round mounting ring 112 , a circular metal or plastic sheet 114 , a bottom cover 140 (shown in FIG. 11 ), a series of tension springs 116 , support bars 122 , a pair of folding hinges 126 equipped with a pair of locking hinges 124 and a pair of armrest supports 127 , a shock absorber 128 (shown in FIGS. 17 , 18 , and 19 ), a base support 130 (shown in FIGS. 1 , 17 , 18 , and 19 ), a back support 132 (shown in FIGS. 1 and 19 ), a pedestal 134 (shown in FIGS. 1 , 17 , and 19 ), and a locking system 200 (shown in FIGS. 13A , 13 B, 14 A, 14 B, 15 A, 15 B, 16 A, and 16 B).
With regard to the fixed inner hemisphere 102 , a support pole 104 is secured to an inner center and sides of the fixed inner hemisphere 102 , through a circular opening 138 , to support the load from the user. The tracks of ball bearings 106 are permanently attached to the fixed inner hemisphere 102 . The movable outer hemisphere 108 is then placed on top of the tracks of ball bearings 106 . A sheet of soft and breathable foam 110 is attached on top of the movable outer hemisphere 108 , and the support pole 104 is inserted into the round mounting ring 112 . The outer surface of the round mounting ring 112 is attached to a circular metal or plastic sheet 114 where the movable outer hemisphere 108 is connected by a series of tension springs 116 .
Through such connections, when the movable outer hemisphere 108 rotates, the series of tension springs 116 helps the circular metal or plastic sheet 114 rotate together. Indeed, the outer hemisphere 108 rotates about its center on fixed inner hemisphere 102 . The tension springs 116 , by allowing tension only, not compression, help the movable outer hemisphere 108 about its center (tilts on the “Y” axis) yet maintains the orientation of the hemispherical seat during such movement. On top of the movable outer hemisphere 108 , a shroud 118 having a larger diameter than those of the fixed inner hemisphere 102 and the movable outer hemisphere 108 , is added covering the foam layer 110 over the fixed inner hemisphere 102 , and the movable outer hemisphere 108 .
The shroud 118 is used as a shell for the chair and it is horizontally cut along the line A-A in FIG. 2 , leaving the top (above the line A-A) of the shroud 118 open, yet concealing the tracks of ball bearings 106 and tension springs 116 . By adopting a seat consisting of multiple layers of rigid hemispheres and a rigid shroud, the present invention does not allow any deformation on the seat when a user sits on the chair. Even though a sheet of soft and breathable foam 110 is used as a cushion for the user's comfort while sitting on the chair, such a cushion forming on the foam 110 does not results in any deformation on the hemispherical seat of the chair. In addition, a support pole 104 where the fixed inner hemisphere 102 is supported absorbs the load from the user.
At the base frame of the shroud 118 , the bottom cover 140 (shown in FIGS. 11 and 12 ) of the chair is installed and the bottom cover 140 is formed with a groove (shown in FIG. 12 ) to receive the outer edge of the shroud 118 . The support bars 122 are attached underneath the circular metal or plastic sheet 114 and they prevent the circular metal or plastic sheet 114 from bending when the movable outer hemisphere 108 is pushed or pulled in the Y-direction by user's movement. Each of the folding hinges 126 is connected to an armrest support 127 , and an extension 129 can be extended for an extra length. For each of the folding hinges 126 , one end of the folding hinge 126 is locked and stands vertically, and the other end of the folding hinge 126 is unlocked. The folding hinge 126 is then folded 90 degrees out and partially slid into the rails. By moving freely both to the right and left sides, in direction of arrows 144 and 146 respectively, as depicted in FIG. 2 , the folding hinges 126 connected to the armrest supports 127 can be positioned under the chair.
FIG. 3 depicts a movable outer hemisphere 108 equipped with elastic ends or springs 150 and hydraulic or pneumatic resistant devices 152 . The elastic ends or springs 150 equipped with hydraulic or pneumatic resistance devices 152 are connected to the hub 154 . As a result, a rigid frame is created on the elastic ends or springs 150 , allowing a balanced movement of the movable outer hemisphere 108 while maintaining the orientation upon the application of the load on the chair.
FIG. 4 is a bottom view of the movable outer hemisphere 108 equipped with elastic ends or springs 150 having hydraulic or pneumatic resistance devices 152 . Multiple elastic ends or springs 150 in the same length equipped with hydraulic or pneumatic resistance devices 152 are connected to the hub 154 at the center.
Referring to FIG. 5 , a top view of the fixed inner hemisphere 102 permanently equipped with the ball bearings 106 on the circular tracks, is depicted. As shown in FIG. 5 , in a preferred embodiment, the ball bearings 106 are placed on a series of circular tracks, on top of the fixed inner hemisphere 102 .
FIG. 6 is a top view of the fixed inner hemisphere 102 permanently equipped with the ball bearings 106 with an alternative placement. In this alternative placement, the ball bearings 106 can be placed on the tracks in a radial arrangement.
Referring to FIG. 7 , the Ergonomic Göbelek Chair of the present invention can also alternatively adopt grease bearings 107 . As shown in FIG. 7 , the grease bearings 107 can be placed on top of the fixed inner hemisphere 102 , in a series of circular arrays. Similar to the alternative arrangement for the ball bearings of FIG. 5 , the grease bearings 107 can also be alternatively adopted on top of the fixed inner hemisphere 102 , either on the tracks in a radial arrangement or in an orthogonal arrangement.
FIG. 8 depicts a top view of the fixed inner hemisphere 102 with polymer bearings. The polymer bearing is a strip or strips made of polypropylene, polyethylene, or Delrin®, which allows metal parts to easily slide with low friction. By adopting polymer bearings, the movable outer hemisphere 108 can slide easily over the fixed inner hemisphere 102 . As shown in FIG. 8 , a circular strip 109 is placed at the top of the fixed inner hemisphere 102 and the ends of a number of rectangular strips 111 are screwed to the circular strip, with an aid of screws 113 . A number of rectangular strips 111 are extendedly and radially positioned on top of the fixed inner hemisphere 102 .
Now referring to FIG. 9 , a detailed cross-sectional view of a portion of FIG. 2 , depicting layers of the fixed inner hemisphere 102 , ball bearings 106 , the movable outer hemisphere 108 , soft and breathable foam 110 , and the shroud 118 , is shown. The ball bearings 106 comprise rows of balls which allow the movable outer hemisphere 108 to move freely in any direction. Specifically, as shown in FIG. 9 , there is a fine gap of approximately 2 mm, between the foam 110 covering the movable outer hemisphere 108 , and the shroud 118 . This gap prevents the movable outer hemisphere 108 and the shroud 118 from contacting each other, and minimizes the space for clothing to be pinched between the movable outer hemisphere 108 and the shroud 118 . It is to be appreciated that this gap can be increased or decreased for any particular chair design, and the specific measurement of 2 mm in a preferred embodiment is not to be considered limiting.
FIG. 10 is a detailed top view for the horizontally cut shroud 118 placed on top of a medium of soft and breathable foam 110 . As shown in FIGS. 9 and 10 , the shroud 118 is installed on top of a medium of soft and breathable foam 110 , which covers the movable outer hemisphere 108 , with a fine gap of approximately 2 mm between the foam 110 and the shroud 118 . This provides a soft seating surface for the user, while also providing a rigid chair structure with the shroud 118 for stability.
FIG. 11 is a cross-sectional view of Ergonomic Göbelek Chair of the present invention depicting an installment of a bottom cover 140 to the base frame of the shroud 118 , when the support pole 104 is inserted through the circular opening 138 on the bottom cover 140 . The circular opening 138 does not rotate and is placed on the bottom cover 140 for an installation of the upper part of the chair to the base part of the chair. The bottom cover 140 is made with a groove for a proper installation of the shroud 118 into the bottom cover 140 . FIG. 12 is a detailed cross-sectional view of the left-end edge of the Ergonomic Göbelek Chair of the present invention, when the outer edge of the shroud 118 is installed with a bottom cover 140 . As shown in FIGS. 11 and 12 , the bottom cover 140 is formed with a groove at the outer edge to receive the edge of the shroud 118 , and the base frame of the shroud 118 is pushed up when the bottom cover 140 is installed.
FIG. 13A is a cross-sectional view of the Ergonomic Göbelek Chair of the present invention depicting a support ring 220 attached to the support pole 104 to attach and fix the locking system 200 . Since the locking system 200 is attached to the support ring 220 and the support ring 220 is fixedly attached to the support pole 104 , when the cone shape cylinder 212 moves up forcing the locking bar shafts 216 to extend outwards underneath the movable outer hemisphere 108 to lock the movable outer hemisphere 108 , the movable outer hemisphere 108 is accordingly prevented from tilting. FIG. 13B is a top view of the locking system 200 in the Ergonomic Göbelek Chair of the present invention, when it is attached to the support ring 220 .
FIG. 14A is a detailed cross-sectional view of the left-end edge of the movable outer hemisphere 108 shown in FIG. 13A , equipped with a locking system 200 which extends outwards underneath the outer hemisphere 108 , when it is locked. As the locking bar shafts 216 in the locking system 200 extend outwards underneath the movable outer hemisphere 108 , the movable outer hemisphere 108 is prevented from tilting.
FIG. 14B depicts a detailed cross-sectional view of the locking system 200 attached and fixed to the support pole 104 through the support ring 220 . As shown in FIG. 14B , the tube 104 is formed with apertures 224 which align with bores 222 formed in support ring 220 such that the locking bar shaft 216 of the locking system 200 can penetrate through the support ring 220 . The support pole 104 also includes A roller bearing 210 formed on the end of the bar shaft 216 . The roller bearing 210 has an outer diameter that is less than or equal to the diameter of bar shaft 216 such that when the bar shaft 216 is urged outwards from tube 104 , the roller bearing 210 can pass through the aperture 224 in tube 104 and into bore 222 of support ring 220 . The locking system 200 is attached to the support ring 220 and the support ring 220 is further attached to the support pole 104 with an aid of screws or bolts 226 .
Referring to FIGS. 15A and 15B , the locking system 200 for the Ergonomic Göbelek Chair of the present invention is depicted. The locking system 200 is placed under the movable outer hemisphere 108 and primarily consists of two (2) tubing posts 202 , and a cylinder cover 206 . The tubing posts 202 further consist of compression springs 208 and the locking bar shafts 216 equipped inside the tubing posts 202 . The locking bar shafts 216 are attached to the compression springs 208 on one (distal) end and the wheel or roller bearings 210 on the other (proximal) end. The diameter of the locking bar shaft 216 is equal or greater to that of the wheel on the wheel bearing 210 . The cylinder cover 206 consists of a cone shape cylinder 212 and is inserted into the support pole 104 . A locking handle 214 which is equipped on the support pole 104 moves up and down to lock or unlock the system.
Specifically, FIG. 15A is a diagrammatic view and FIG. 15B is a top view of the locking system 200 for the Ergonomic Göbelek Chair of the present invention when it is unlocked. As shown in FIG. 15A , when the locking handle 214 moves up, the cone shape cylinder 212 moves down and the system is unlocked, rendering the movable outer hemisphere 108 to move freely. As a result, in its unlocked position, the compression springs 208 urge the locking bar shafts 216 to be pulled back into the post tubing 202 , in the direction of arrows 203 and 205 , respectively. Therefore, in its unlocked position, as shown in FIG. 15B , there is no locking bar shaft extended underneath the movable outer hemisphere 108 . In addition, as shown in FIG. 15B , the locking system 200 is attached to the support ring 220 , and the support ring 220 is further attached to the support pole 104 , as described above.
FIGS. 16A and 16B illustrate a locking system for the Ergonomic Göbelek Chair of the present invention when it is locked. As shown in FIG. 16A , when the locking handle 214 moves down, the cone shape cylinder 212 moves up forcing the locking bar shafts 216 attached to the wheel bearings 210 to be pushed out within the tubing posts 202 , in the direction of arrows 207 and 209 , respectively. As a result, as shown in FIG. 16B , the locking bar shafts 216 are extended under the movable outer hemisphere 108 and prevent the movable outer hemisphere 108 from tilting. As shown in FIG. 16B , the locking system 200 is attached to the support ring 220 , and the support ring 220 is further attached to the support pole 104 , as described above.
FIG. 17 depicts a diagrammatic view of the Ergonomic Göbelek Chair of the present invention with its base support 130 and a pedestal 134 equipped. A pair of the folding hinges 126 having armrest supports 127 are folded 90 degrees out in the direction 142 (shown in FIG. 2 ), and slid in under the chair when the chair is used as an office stretch GYM ball, or upon any other needs of the user. The folding hinges 126 can also be extended by use of an extension 129 (shown in FIG. 2 ) for an extra length, when the user needs longer folding hinges. The shock absorber 128 is attached to absorb any shock from an excessive load applied on the chair. The base support 130 is equipped with a height adjustment lever 120 which enables the chair to move up and down for the desirable height depending on the user's need. In addition, a locking handle 214 for the locking system 200 is equipped on the support pole 104 . Selectively, a wheel assembly can be installed at the end of the pedestal 134 .
FIG. 18 is a back view of the Ergonomic Göbelek Chair of the present invention with its base support 130 and an alternative pedestal 135 equipped. Differently from the pedestal 134 having legs described in FIG. 17 , the alternative pedestal 135 may be formed with a heavy base which does not have any legs. The alternative pedestal 135 with the heavy base can provide more stability to the user when the chair does not need to be moved often, or the chair is used for over-weighted people. For easier movement of the chair with such a heavy base, a handle 131 is equipped. The handle 131 is placed at the top of a back support 132 , on the back of the lumbar cushion 133 . With an aid of the handle 131 , the user of the Ergonomic Göbelek Chair of the present invention can tilt the heavy chair when the chair needs to be moved to some other locations. When the chair is tilted, the side wheels 137 placed on the side of the alternative pedestal 135 enable the user to easily move the chair along the ground, by a rolling movement of the side wheels 137 . The use of the side wheels 137 along with the handle 131 further enables the user to move the Ergonomic Göbelek Chair of this invention along the slope.
FIG. 19 is a diagrammatic view of the Ergonomic Göbelek Chair of the present invention equipped with a back support 132 . The back support 132 for the Ergonomic Göbelek Chair of the present invention is folded 180 degrees out and positioned under the chair when the chair is used as an office stretch GYM ball, or upon any other need of the user. The lumbar cushion 133 is installed on top of the back support 132 for the comfort of the user. As shown in FIG. 19 , a wheel assembly 136 may be attached to the end of the pedestal 134 , providing mobility of the chair.
FIG. 20 is a partial vertical cross-sectional view of an alternative embodiment 300 of the Ergonomic Göbelek Chair of the present invention. In the alternative embodiment 300 , the Ergonomic Göbelek Chair can be equipped with a movable outer hemisphere 308 and a shroud 318 , without an installation of the fixed inner hemisphere disclosed in the preferred embodiment. The movable outer hemisphere 308 simply sits on the five (5) single bearings 306 . Each of the single bearings 306 is equipped with a roller within a socket to allow the movable outer hemisphere 308 to move into various directions. The inside surface 309 of the movable outer hemisphere 308 rolls along the single bearings 306 which are installed at the end of the vertical support 303 and four (4) lateral supports 304 . The vertical support 303 primarily absorbs the load from the user, and may be made of materials having more strength for the structural durability and integrity of the chair. A series of tension springs 316 and a circular metal sheet 314 are also used as in the preferred embodiment. By doing so, when the movable outer hemisphere 308 rotates, the series of tension springs 316 helps the circular metal sheet 314 rotate together. Also as in the preferred embodiment, the tension springs 316 allow tension and help the movable outer hemisphere 308 move up and down and serve to maintain the orientation of the hemispherical seat during such movement.
As disclosed in the preferred embodiment, the movable outer hemisphere 308 is covered with a soft and breathable foam layer 310 , which is used as a cushion for the user's comfort while sitting on the chair. The shroud 318 placed on top of a soft and breathable foam layer 310 is used as a shell for the chair and it is horizontally cut as in the preferred embodiment. At the base frame of the shroud 318 , a bottom cover 340 of the chair is installed. In addition, as in the preferred embodiment, the vertical support 303 is inserted into a base support 330 which is further equipped with a pedestal 334 at its end and a height adjustment lever (not shown in FIG. 20 ) for the desirable height adjustment for the user.
Referring now to FIG. 21 , a side view of an alternative embodiment of the Ergonomic Göbelek Chair of the present invention is depicted and designated 400 . As shown in FIG. 21 , similar to the preferred embodiment 100 , the alternative embodiment 400 of the Ergonomic Göbelek Chair of the present invention is formed with a shroud 402 , a sheet of soft and breathable foam 404 , a back support 410 equipped with a lumbar cushion 412 , a base support 416 , a height adjustment lever 418 and a pedestal 420 . The back support 410 is extendable in direction of arrow 422 for a desirable height of the back support 410 . Specifically, the alternative embodiment 400 of Ergonomic Göbelek Chair of the present invention includes a pair of folding hinges 406 equipped with ergonomic armrests 408 . The folding hinges 406 can extend in direction of arrow 424 , for an adjustable height of the armrests 408 depending upon the user's desire. The ergonomic shape of the ergonomic armrests 408 can provide for more comfort when the user leans his or her arms on the armrests. FIG. 22 is a diagrammatic view of the alternative embodiment of the Ergonomic Göbelek Chair of the present invention when the back support 410 and the ergonomic armrests 408 are positioned beneath the chair. Both back support 410 and the ergonomic armrests 408 are foldable. As shown in FIG. 22 , the back support 410 is folded 180 degrees out and the ergonomic armrests 408 are folded 90 degrees out to be positioned folded and slid in under the chair such that the alternative embodiment of Ergonomic Göbelek Chair of the present invention is used as an office stretch GYM ball. It is also convenient for the user of the Ergonomic Göbelek Chair of the present invention to store the chair in a smaller space by folding the back support 410 and the ergonomic armrests 408 .
While there have been shown that are presently considered to be preferred embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope and spirit of the invention. | The Ergonomic Göbelek Chair of the present disclosure is useful for avoiding work related back and neck pain associated with extended periods of time sitting by providing a hemispherical seat which promotes correct posture and spine alignment as a user sits. The hemispherical seat includes a fixed inner hemisphere, a movable outer hemisphere received by and positioned over the inner hemisphere, and a shroud enclosing a portion of the inner and outer hemispheres. Affixed to the inner hemisphere, between the inner hemisphere and the outer hemisphere, is a series of bearings which allow the outer hemisphere to move adjacent to the inner hemisphere. A locking system locks and unlocks the outer hemisphere. The Ergonomic Göbelek Chair further includes foldable back and arm rests capable of folding away from the hemispherical seat for use of the hemispherical seat as a stretch gym ball. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to pressure responsive valve assemblies and in particular to such a valve assembly adapted for use in a decanting apparatus in a wastewater treatment facility.
Certain wastewater treatment processes, especially those utilizing sequential batch reactor techniques or processes, require that clarified fluid be periodically withdrawn from the reactor or digester within which the process is occurring. During certain cycles within the reactor, especially mix cycles, sludge is agitated with all of the fluid in the reactor in order to mix organic degrading bacteria with organic materials in the water being treated. It is important that the decanting system not allow the sludge to enter the decanter during the mix cycles or have sludge settle within the decanting system so that when the sludge is settled and clarified liquid is withdrawn from the reactor, no sludge is withdrawn with the clarified liquid. Sludge discharged with the clarified liquid causes substantial downstream pollution.
One of the major problems with certain prior art decanter systems for use in batch reactors has been that a receiver for the decanter has had the interior thereof open to fluid within the reactor during sludge mixing cycles. When the sludge is being mixed with the incoming effluent and the entire reactor is in a generally mixed state, sludge is near the top of the reactor as well as the bottom. If the receiver is open at this time, the sludge usually enters the receiver and settles therein during settling cycles. Thereafter, when the clarified fluid is withdrawn through the receiver, the sludge that is within the receiver is entrained with the clarified fluid to pollute the effluent.
Over the years, engineers have developed various devices to solve this problem. In one such device, an initial quantity of clarified effluent removed from the reactor during each decanting cycle is flushed back into the reactor so as to return the entrained sludge. However, such a solution requires a pump and control mechanisms which complicate the system and can easily fail leading to substantial downstream pollution.
Other attempts to resolve the problem of sludge settling within the receiver have been directed to physically removing the receiver from the tank during mixing cycles. This typically requires a cumbersome and expensive structure which is suitably strong to hold a decanting system out of the reactor fluid during the mix cycle. In addition, where freezing is likely to occur, fluid within the decanting structure may freeze if raised from the liquid in the reactor, or the fluid level at the top of the reactor may freeze which may make it difficult or impossible to raise and lower the decanting structure.
Finally, various types of pressure responsive valves or flaps have been placed in the openings to the decanting system to keep sludge out of the system when the contents of the reactor are being mixed. While such valves or flaps have reduced the sludge in the decanted fluid, none have been successful in keeping sludge sufficiently out of the effluent to satisfy many pollution control requirements, especially at relatively high wastewater flow rates. In particular, such prior art valves often have provided surfaces onto which the entrained sludge may settle during the settling cycles. Then during decanting cycles, the sludge becomes entrained in the clarified effluent withdrawn from the reactor through the receiver. In many pressure responsive valves, the structure forming the valve seat extends beyond the interface of the valve member with the valve seat. If such a valve were used in a decanting apparatus for a wastewater treatment reactor, the structure forming the valve seat would extend beyond the valve member into the reactor providing significant surface area for sludge to settle on during the settling cycles.
SUMMARY OF THE INVENTION
The present invention provides a pressure responsive valve assembly particularly well adapted for use in a decanting apparatus of a batch wastewater treatment system.
The valve assembly is adapted to prevent the inadvertent discharge of sludge with clarified water from the reactor during the decanting of the clarified water from the reactor by reducing the ability of sludge to be carried into or settle onto the valve assembly during the preceding settle period.
The valve assembly generally comprises a valve plate, a valve member and a valve member support structure. The valve plate is generally cylindrical, having an inner and an outer planar surface. An inner frusto-conical wall which diverges outward from the outer planar surface to the inner planar surface defines a valve seat and a discharge passageway through the valve plate. The valve seat includes a circular interface formed at the intersection of the outer planar surface and the inner frusto-conical wall.
The valve member has a valve head and a centrally and perpendicularly aligned valve stem. The valve head is also generally frusto-conical, having a peripheral edge diverging outward from a frontal circular surface to a rearward circular surface. The angle of divergence of the valve head is smaller than the angle of divergence of the valve seat and the valve head is sized proportionally to the valve seat, so when the valve head is biased against the valve seat the circular interface of the valve seat sealingly engages the peripheral edge of the valve head between the frontal and rearward circular surfaces.
The valve member support structure includes a pair of upstanding support members which maintain a valve stem receiving tube in a central, axially aligned, and spaced relation behind the discharge passageway of the valve plate. A coil spring is axially aligned within and at a distant end of the valve stem receiving tube. The valve stem is received within the valve stem receiving tube through an open, near end. The coil spring biases the valve stem outward towards the valve plate so that the valve head sealingly engages the valve seat.
The valve assembly is preferably securely mounted in ports in a clarified liquid receiver on the decanting apparatus so that the valve plate extends across the port and the valve assembly extends inside the receiver, so as to block flow into the receiver through a port when the respective valve assembly is in a closed position thereof. The differential pressure across the valve head between the reactor and the receiver is preferably controlled by a control valve downstream and in flow communication with the receiver. When the control valve is opened, the differential pressure across the valve head increases so as to compress the coil spring and advance the valve head away from the valve seat thereby allowing clarified wastewater to drain from the reactor. When the control valve is closed the differential pressure across the valve head is decreased so that the coil spring biases the valve head into sealing engagement with the valve seat.
OBJECTS OF THE INVENTION
Therefore, the objects of the invention are: to provide a pressure responsive valve assembly for use in conjunction with a decanting apparatus of a wastewater treatment reactor and system which is highly effective in preventing sludge from being drawn from the reactor with clarified or treated effluent during decanting cycles; to provide such a valve assembly which greatly reduces the ability of sludge to settle on the valve during a settling cycle of the reactor; to provide such a valve assembly which is opened and closed by pressure changes in the reactor system; to provide such a valve assembly which is relatively inexpensive, easy to install, and has a relatively long life expectancy. Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.
The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic cross-sectional view of a wastewater treatment facility having a decanting apparatus including pressure responsive valve assemblies in accordance with the present invention.
FIG. 2 is an enlarged and fragmentary view of the decanting apparatus, taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged and fragmentary front elevational view of the decanting apparatus, with portions broken away therefrom to show one of the valve assemblies.
FIG. 4 is an enlarged and fragmentary cross-sectional view of the decanting apparatus showing one of the valve assemblies, taken generally along line 4--4 of FIG. 3 and showing the valve assembly in a closed position.
FIG. 5 is an enlarged and fragmentary cross-sectional view of the decanting apparatus and one of the valve assemblies, taken along line 5--5 of FIG. 4 with portions broken away to show interior detail thereof and showing the valve assembly in an open position.
FIG. 6 is an enlarged and fragmentary cross-sectional view of the decanting apparatus and one of the valve assemblies, taken along line 6--6 of FIG. 4.
FIG. 7 is an enlarged and fragmentary cross-sectional view of the decanting apparatus and one of the valve assemblies, taken along line 7--7 of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Referring to the drawings in more detail, the reference numeral 1 generally represents a pressure responsive valve assembly of the present invention. A plurality of the valve assemblies 1 are spaced in a row in spaced relationship to one another in a decanting apparatus 2, as shown in FIG. 1. Each valve assembly 1, as shown in FIG. 5, generally comprises a valve plate 10, a valve member support structure 11, a coil spring 12, and a valve member 13, having a valve head 14 and a valve stem 15.
For purposes of locating various parts and as seen in FIGS. 4 and 5, the valve plate 10 is generally cylindrical or annular in shape having an inner, interior, or upper planar surface 20 and a generally parallel outer, exterior, or lower planar surface 21. A radially inward frusto-conical wall 23 which diverges outward from the lower planar surface 21 to the upper planar surface 20, forms or defines both a valve seat 24 and a discharge passageway 25 through the valve plate 10. (As used herein, the terms "upper" and "lower" are utilized for describing the parts relative to the drawings only and are not intended to be limiting). The valve seat 24 includes a circular interface 26 formed at the intersection of the lower planar surface 21 and the frusto-conical wall 23.
The valve member support structure 11 includes a pair of upstanding support members 30 and a valve stem receiving tube 31. The receiving tube 31 is generally cylindrical having an internal passageway 33, an open end 34 and a closed end 35. The upstanding support members 30 are secured to and extend away from the upper planar surface 20 of the valve plate 10 and are secured to the valve stem receiving tube 31 so as to space the valve stem receiving tube 31 away from the discharge passageway 25 in axial alignment therewith and perpendicular to the interface 26. The valve stem receiving tube 31 is centrally aligned with the discharge passageway 25 and positioned so that the open end 34 of the valve stem receiving tube 31 is closer to the discharge passageway 25 than the closed end 35, and the open end 34 is spaced away from the discharge passageway 25.
As shown in FIG. 5, the spring 12 is a compression type spring having a diameter slightly smaller than the diameter of the internal passageway 33 of the valve stem receiving tube 31 and is placed within the internal passageway 33 so that an abutting end 41 of the spring 12 abuts against the closed end 35 of the valve stem receiving tube 31 and an extending or opposite end 42 of the spring 12 extends along the internal passageway 33 towards the open end 34 of the valve stem receiving tube 31.
The valve stem 15 of the valve member 13 is generally cylindrical having a diameter slightly smaller than the diameter of the internal passageway 33 of the valve stem receiving tube 31 and equal to or larger than the diameter of the spring 12. The valve head 14 of the valve member 13 is generally frusto-conical, having a frontal circular surface 45 (lower surface in FIG. 5), a rearward circular surface 46 (upper surface in FIG. 5), and a circumferential surface 47 having an upper cylindrical section 48 and a lower frusto-conical section 49 diverging outward from the frontal circular surface 45 to the rearward circular surface 46.
A proximate end 55 of the valve stem 15 threadingly engages a threaded collar 56 axially and centrally mounted on the rearward circular surface 46 of the valve head 14 such that the valve stem 15 extends perpendicularly away from the rearward circular surface 46. A distal end 57 of the valve stem 15 is slidingly received within the valve stem receiving tube 31 and abuttingly engages the extending end 42 of the spring 12. The spring 12 thereby operably functions as biasing means and biases the valve stem 15 outward towards the valve seat 24 so that the valve head 14 sealingly engages the valve seat 24 at the circular interface 26 when in a closed position thereof, as shown in FIGS. 4 and 7.
The diameter of the circular interface 26 is greater than the diameter of the frontal circular surface 45 and smaller than the diameter of the rearward circular surface 46. Also, the angle of divergence of the frusto-conical surface 47 of the valve head 14 from the frontal circular surface 45 to the rearward circular surface 46 is smaller than the angle of divergence of the inner frusto-conical wall 23 from the lower planar surface 21 to the upper planar surface 20 so that when the valve head 14 is biased against the valve seat 24, the frontal circular surface 45 of the valve head 14 extends beyond the circular interface 26 and the frusto-conical surface 47 of the valve head 14 sealingly engages the valve seat 24 along the circular interface 26, as shown in FIG. 7.
When the differential pressure across the valve head 14 exceeds the biasing force of the spring 12, the valve head 14 is forced out of sealing engagement with the valve seat thereby compressing the spring 12 and opening the discharge passageway 25, so as to place the valve assembly 1 in an open configuration thereof as is seen in FIG. 5. Conversely, when the differential pressure across the valve head 14 drops below the biasing force of the spring 12, the spring 12 biases the valve head 14 into sealing engagement with the valve seat 24.
Although it is foreseen that the pressure responsive valve assembly 1 of the present invention may be used in a variety of applications, it is particularly well adapted for use with a decanting apparatus 2 such as that disclosed in FIG. 1. The decanting apparatus 2 is adapted for use in a wastewater batch reactor 71 to decant clarified wastewater from a high water level 72 to a low water level 73. The decanting apparatus 2 comprises support means, such as illustrated supporting structure 75, a clarified liquid receiver 76, flotation means, such as illustrated floats 77, and a discharge manifold 78. The discharge manifold 78 sealably passes through a sidewall 79 of the wastewater batch reactor 71 and empties into a municipal sewer, discharge stream or the like (not shown).
The discharge manifold 78, which includes a flexible segment 85, extends to and is in flow communication with the clarified liquid receiver 76. The floats 77 which are secured to the clarified liquid receiver 76 maintain the clarified liquid receiver 76 at a position normally one to two feet below the surface of the liquid in the wastewater batch reactor 71. The flexible segment 85 which is positioned below the low water level 73 allows the clarified liquid receiver 76 to rise and fall in correspondence to the liquid level in the wastewater batch reactor 71.
A control valve 86 is positioned along the discharge manifold 78 below the low water level 73. The valve 86 may be selectively activated to allow or prevent flow through the manifold 78.
The clarified liquid receiver 76 is an elongate tube centrally located relative to an end of the discharge manifold 78 and flow communicating internally therewith. The clarified liquid receiver 76 is generally horizontally positioned and remains horizontally aligned along its axis as it correspondingly rises and descends with the liquid level.
Located at spaced locations along the receiver 76 near the lower side thereof are a plurality of openings, apertures or ports 90, as shown in FIG. 2. The ports 90 open into a central collecting chamber or cavity 92 of the receiver 76, as shown in FIG. 3. It is foreseen that other receiving configurations such as circular cross-shaped would function as the illustrated elongate tube receiver 76. A valve assembly 1 is located in each port 90. The valve assemblies 1 are preferably all positioned or aligned so as to face in a downwardly direction throughout the range of operation of the clarified liquid receiver 76 from the low water level 75 to the high water level 72. For example, at the low water level 73, the valve assemblies 1 are positioned so as to generally face directly downward. As the water level rises, the clarified liquid receiver 76 remains in fixed relation with the discharge manifold 78 so that, as the discharge manifold pivots in response to the rising fluid level, the downward positioning of the valve assemblies 1 correspondingly pivots, such that at the high water level 72, the valve assemblies 1 are positioned so that the axis of the valve stem 15 is angled approximately 45° relative to vertical and the frontal circular surface 45 of the valve head 14 as shown in FIG. 3.
A circular valve support member 93 extends downward from the clarified liquid receiver 76 along the outer edge of each port 90 so as to be in flow communication with the cavity 92. A circular flange 94 having a bore 95 therethrough is secured to each circular valve support member 93 at the end of the valve support member 93 spaced away from the clarified liquid receiver 76. The inner diameter of the bore 95 is smaller than the inner diameters of the ports 90 and the valve support members 93 and slightly greater than the diameter between the upstanding support members 30 of the valve member support structure 11. The valve plate 10 is secured to the circular flange 94 by a set of bolts 96 so that the valve plate 10 extends completely across the bore 95 and the valve member support structure 11 and the valve member 13 extend within the cavity 92 of the receiver 76 as shown in FIG. 3. A spacer or gasket 97 is positioned between the circular flange 94 and the valve plate 10.
The valve head 14 is constructed of a suitable elastomeric composition for sealing with the valve seat 24 which is constructed of metal such as stainless steel. A suitable elastomeric composition for the valve head 14 has been found to be a two-part polyurethane rubber that is moulded to form, such as is available in a 65A diameter from Dennis Chemical Company of St. Louis as a two component mixture under the names Denflex 9811-2 (polyurethane base) and Denflex 9800-T (isocyanate prepolymer).
In use, the wastewater batch reactor 71 is typically partially prefilled with fluid to the low water level 73. This fluid is generally from a previous usage of the reactor 71 and includes a substantial amount of activated sludge (not shown) in a layer settled on the bottom of the reactor 71. Additional wastewater to be treated is added to the reactor to bring the fluid level up to the high water level 72. Thereafter, the fluid is agitated and/or aerated in accordance with the desired sequential batch reactor treatment selected for such wastewater, after which all agitation of the liquid is stopped, so that the sludge therein may again settle to the bottom. During agitation, microorganisms in the sludge modify biological wastes in the reactor so as to effectively remove the waste from the water. After settling, a clarified liquid layer at the top of the reactor remains so as to extend at least between the low water level 73 and the high water level 72. During the agitation and settling steps, the control valve 86 is closed so that the differential pressure between the frontal circular surface 45 and the rearward circular surface 46 of the valve head is negligible so that the spring 12 maintains the valve head 14 in sealing engagement with the valve seat 24, thereby operably preventing fluid inside the reactor 71 from entering the cavity 92 of the receiver 76. The downward angled valve head 14 and the seating of the valve head 14 at the outer planar surface 21 of the valve plate 10 greatly reduces the ability of sludge to settle onto the valve assembly 1 during the settle stage and to later be drawn out of the reactor 71 with clarified effluent.
When it is desired to drain the clarified liquid layer 101, the control valve 86 is opened so that clarified fluid maintained in the discharge manifold 78 drains from the manifold 78 and the receiver 76. This produces a partial vacuum within the receiver 76 and a substantial differential pressure across the outer planar surface 20 and the inner planar surface 21 of the valve seat 24 separating the cavity 92 of the receiver 76 from the fluid in the reactor 71. The differential pressure causes the spring 12 to compress and the valve assembly 1 to open, allowing clarified fluid to flow through the valve assembly 1 into the receiver 76 and through the discharge manifold 78 to a predetermined discharge site. The control valve 86 is selectively maintained open by an operator, computer control or the like, until the clarified fluid is drained to the low water level 73, after which the control valve 86 is shut. The differential pressure across the valve head 14 again becomes negligible and the spring 12 biases the valve head 14 into sealing engagement with the valve seat 24.
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 pressure responsive valve assembly for use in a decanting apparatus for a wastewater treatment reactor. The valve assembly includes a cylindrical valve plate, a valve member support structure, a valve spring, and a valve member comprising a valve stem and a valve head. A discharge passageway extending through the valve plate has a frusto-conical valve seat located therein. The valve head also has a frusto-conical design having an angle of divergence smaller than that of the valve seat so that when the valve head is biased against the valve seat by the valve spring, the valve seat sealingly engages a peripheral edge of the valve seat. The valve member support structure maintains the valve member in proper alignment with the valve seat and in engaging relationship with the valve spring. The valve assembly is configured so as to reduce the ability of sludge to pass through the valve during mix cycles or to settle on the valve assembly during settling cycles of a wastewater treatment process thereby reducing the possibility that such sludge will subsequently be withdrawn from the reactor with decanted liquid during the decanting cycle. | 1 |
TECHNICAL FIELD
This invention relates generally to multi-class digital networks and, in particular, to a multi-class digital network in which network functions are shared by a network control element and node control elements to ensure efficient utilization of network resources.
BACKGROUND OF THE INVENTION
A multi-class digital network must accommodate traffic having different characteristics, quality of service (QOS) requirements, and transport modes. For example, a multi-class backbone network may be required to support both connection-based traffic and connectionless traffic. Further complication is traffic may include several classes differentiated by their characteristics and service requirements. The traffic classes may require different and possibly conflicting controls in order to satisfy service commitments and ensure acceptable service quality.
Asynchronous Transfer Mode (ATM) switching technology was developed to provide multi-service digital transport. It was assumed that ATM networks would provide the flexibility and quality of service required to satisfy the demand for digital services.
One disadvantage of ATM networks is that they are adapted to transport packets of only one size and format. Consequently, the packets of services which do not use ATM format must be deconstructed on admission to the ATM network by network edge devices and reconstructed by network edge devices on egress from the ATM network. This slows service delivery, increases computational requirements and complicates the structure and functionality of edge device interfaces.
The varying service requirements in a multi-class network are difficult to satisfy without traffic segregation and network partitioning. For example, certain services such as voice and video are somewhat loss tolerant but delay intolerant, while other services such as the exchange of data packets between computers are quite delay tolerant but completely loss intolerant. In accommodating such variations in service, a multi-service network naturally segregates into a plurality of layers or “bands” which respectively serve the requirements of different types of traffic. This natural division of a network into service bands is well understood and has been widely discussed in the relevant literature.
A challenge in network management is designing network routing and admission controls to manage the service bands in a multi-class network to efficiently accommodate fluctuating service demands. It is well understood that while total network traffic may change relatively slowly over time, the traffic mix in a multi-class network may fluctuate rapidly and unpredictably. To date, efficient methods of accommodating rapid and unpredictable fluctuations in traffic service demand have eluded network designers and traffic managers. There therefore exists a need for a multi-service, multi-class digital network and methods for controlling the network which can accommodate the increasing demand for digital services without unreasonable investment in network infrastructure.
SUMMARY OF THE INVENTION
It an object of the invention to provide a multi-class digital network which includes a network control element for performing network-wide functions including network topology monitoring and computation and distribution of network traffic routing sets to network nodes in response to changes in network topology.
It is a further object of the invention to provide a multi-class digital network in which node control elements perform distributed traffic admission control, traffic routing and service-rate allocation for each class of service served by an egress link when traffic connections are set up through the egress link.
It is yet a further object of the invention to provide a multi-class digital network in which service-rate controllers are adapted to control egress on an egress link, the service-rate controller receiving service-rate allocations from associated node control elements.
It is yet a further object of the invention to provide a multi-class digital network wherein the network is a multi-service network adapted to transport digital packets that require different transport modes, each transport mode consisting of at least one transport protocol.
It is another object of the invention to provide a multi-class digital network wherein a network control element also performs network sizing computations which produce periodic specifications for inter-nodal link sizes.
The invention therefore provides a multi-class digital network, comprising:
a network control element which periodically receives network traffic and network state information from network nodes, the network control element performing at least the functions of:
a) network topology monitoring; and
b) computing and distributing network traffic routing sets to network nodes as required;
node control elements which perform at least the functions of:
a) traffic admission control;
b) connection routing; and
c) computation of a service rate allocation for a class served by an egress link when a new traffic connection is set up through the egress link; and
a service rate controller adapted to control egress on the egress link, the service rate controller receiving the service rate allocations from an associated node control element after they are computed.
The invention also provides a network control element for a multi-class digital network, comprising:
at least one connection with the network adapted to periodically receive network traffic and network state information from node control elements in the network;
at least one algorithm for maintaining a current network topology using the network state information; and
at least one algorithm for computing routing sets for switching nodes in the network based on the network traffic and network state information.
The multi-class digital network in accordance with the invention distributes the network processing load between a network control element which handles global functions that are best performed at the network level and traffic functions which are best performed in a distributed fashion at the node level of the network. This distribution of functionality minimizes computational effort and maximizes transmission efficiency.
The network control element in accordance with the invention receives traffic intensity and network state information from the nodes in the network which periodically report such information to the network control element. Using the network state information, the network control element maintains a network topology. The network topology and the traffic intensity data are used by the network control element to compute network traffic routing sets which are identified to the nodes along with an order of preference. The computed routing sets are distributed to the network nodes and used by the network nodes in processing traffic admission requests.
The network nodes include node control elements which control traffic admission, traffic routing and the computation of service-rate allocations for classes of traffic served by egress links at the node.
Edge network node control elements receive traffic admission requests from traffic sources. The edge node control elements compute an equivalent bit rate for each traffic admission request based on a novel method in accordance with the invention. In order to minimize further processing when it is necessary to establish a connection across the network, the edge node control element also computes variables which enable subsequent nodes involved in the connection to rapidly compute an approximate equivalent bit rate used in route selection.
The multi-class digital network in accordance with the invention preferably supports a plurality of digital services which may require different transport modes, each transport mode consisting of at least one transport protocol. Since different transport protocols require different packet sizes, a link controller is provided which accommodates variable packet sizes so that packets need not be disassembled and converted to a standard format by edge device interfaces.
The multi-class digital network adopts a service-rate discipline comprising a guaranteed minimum rate per class in order to ensure efficient use of the network while meeting transmission rate and quality of service commitments. In order to minimize computing requirements for routing, high-frequency, low bit-rate traffic is preferably served by paths commonly referred to as direct routes set up through the network. High bit-rate connection-oriented traffic is preferably served by connections set up on demand. Each service type is preferably assigned to at least one class and each class is preferably assigned to a separate band in the network. The bands are dynamically configured and have elastic boundaries which fluctuate with traffic load. Unused time slots accept traffic from any waiting source in a predetermined hierarchical order in which connectionless traffic without a quality of service is served last.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be further explained by way of example only and with reference to the following drawings wherein:
FIG. 1 is a schematic diagram of a multi-class digital network in accordance with the invention;
FIG. 2 is a schematic diagram showing cost ellipses used by a network control element to compute routing sets for the network node shown in FIG. 1;
FIG. 3 is a schematic diagram of an example network used to illustrate determining the routing sets for network nodes by a network control element;
FIG. 4 is a routing table for a destination node 11 shown in FIG. 3;
FIG. 5 is a schematic diagram showing network links partitioned into banks corresponding to classes of traffic;
FIG. 6 is a schematic diagram illustrating network paths and network connections through a sample network;
FIG. 7 is a graph illustrating the relationship between transport efficiency and processing throughput in relation to a network which uses connections or paths;
FIG. 8 is a schematic diagram depicting intraband and interband controls in a multi-class digital network in accordance with the invention;
FIG. 9 is a schematic diagram illustrating capacity management in a multi-class digital network with paths and connections where connection-level sharing is practised;
FIG. 10 a is a schematic diagram illustrating capacity management with paths and connections in a network link;
FIG. 10 b is a schematic diagram illustrating capacity management, as in FIG. 10 a , except that a connection band is not subdivided, and any unallocated capacity is granted to connectionless-mode traffic;
FIG. 11 is a schematic diagram illustrating a rate controller in a node control element for a transport link in a multi-class digital network in accordance with the invention;
FIG. 12 is a schematic diagram of class allocations for variable packet sizes in a multi-class, multi-service network in accordance with the invention;
FIG. 13 is a schematic diagram illustrating a preferred arrangement for processing connection admission requests at node control elements in accordance with the invention; and
FIG. 14 is a graph illustrating a method used for minimizing processing required to compute equivalent bit rates as connections are established across a multi-class digital network in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a schematic diagram of a multi-class network in accordance with the invention, generally indicated by the reference 20 . The network includes a plurality of switching nodes 22 , hereinafter referred to simply as “nodes”. The nodes are interconnected by transport links 24 , hereinafter referred to simply as “links”. The links 24 may be any one of a number of types of transport links well known in the art. The links 24 are designed to support a transfer rate appropriate for the traffic loads that they must transport. The multi-class network 20 in accordance with the invention includes a network control element 26 which preferably performs at least the functions of network topology monitoring, and computing and distributing network traffic routing sets to the nodes 22 , as required. The network control element 26 also preferably performs the function of network sizing computations which produce periodic specifications for the sizes of the inter-nodal links 24 . The network control element 26 is, for example, a server connected to a one of the nodes 22 , or the like.
In the multi-class network 20 , other network functions are preferably distributed among node control elements 28 . Consequently, the node control elements 28 perform traffic admission control, connection routing for connection-oriented traffic and the computation of service-rate allocations for classes served by egress links managed by a node control element 28 . Each of these functions will be described below in detail. Even though only one node control element 28 is shown in FIG. 1, it will be understood that each node 22 includes a node control element 28
The multi-class network 20 may carry classes of traffic having distinctly different characteristics and service requirements. The different service requirements for the various traffic classes are difficult to meet without traffic segregation and network partitioning into layers or “bands”. For example, open-loop controls and closed-loop controls have conflicting attributes and require distinctly different handling. Both can, however, operate efficiently in the same network if each control is applied to a separate network band. Connection-based traffic and connectionless traffic also have other distinctly different service requirements. For example, human-to-human communications such as voice and video are somewhat loss-tolerant in that a certain number of packets can be lost without detection by the human participants, yet they are quite delay-intolerant in that any delay or “jitter” in packet delivery is quite noticeable. Data communications between computers on the other hand are quite delay-tolerant but strictly intolerant to packet loss.
Network segregation into bands is preferably done so that each network band corresponds to a traffic class. The same control method applied to a given class should be practised across the network. In order to efficiently use the network, the boundaries between successive bands must be elastic to permit band capacity to expand and shrink in response to variations in network traffic.
Topological design and overall network dimensioning are based on long-term traffic forecasts and other considerations well known in the art. Aggregate network design is a slow process which takes place over time. Network sizing is therefore preferably a function performed by the network control element 26 . Network sizing requires traffic characterization. Performance estimation is a function of traffic load and estimates of spatial traffic distribution. Given the difficulty of traffic characterization in a multi-band, multi-service network, effective network sizing computations may be based on traffic and performance measurements. As shown in FIG. 1, the network control element 26 therefore receives traffic measurement data from the node control elements 28 . The traffic measurement data is transferred to the network control element 26 through the network. The traffic measurement data is accumulated in appropriate tables and periodically analyzed in order to determine appropriate sizes for the links 24 in the network. The entire network 20 must be provisioned to serve the combined traffic load of all classes. The combined traffic load is, of course, variable over time, however, the combined traffic load is less volatile than the traffic loads of the individual classes. The network traffic data may be sorted to determine traffic loads on each inter-nodal link 24 and the data can be used to determine when a link size is inadequate or when a direct link between unlinked nodes is warranted. Consequently, in addition to traffic data each node control element 28 involved in traffic admission control should report to the network control element 26 the details of admission request denied and the cause of admission failure. The frequency at which an analysis of this data is conducted depends on a number of factors well known in the art, including storage capacity at the network control element 26 .
The node control elements 28 also pass network state information messages to the network control element 26 to permit the network control element 26 to maintain topological awareness of the network 20 and its state. In some networks, a topological map of the network is maintained in every node. Consequently, “flooding” of state information is required. This flooding of information uses network resources and ties up node computing cycles. In order to free resources for transport control, in the multi-class network in accordance with the invention, a complete topological network map is maintained only at the network control element 26 . To ensure that the topological information is accurate and complete, each link 24 is preferably monitored by each of the nodes 22 at its opposite ends. Consequently, if the status of a link 24 changes, the change is reported by two nodes 22 to the network control element 26 . Likewise, the state of each node 22 is monitored by two neighbouring nodes 22 appointed by the network control element 26 . If any node 22 malfunctions or becomes inoperable, the network control element 26 appoints alternate monitor(s) for any other nodes that were monitored by that node. This method ensures that the network control element 26 receives accurate network state information to guarantee that network topology is accurate and up to date.
The network topology is used, as required, to compute network routing sets which are used by node control elements 28 to route traffic admission requests across the network. Direct routes, which may include direct links or shortest route paths through the network, are the routes of first preference. Indirect routes from an originating node 22 to a destination node 22 are preferably sorted according to cost ellipses 30 illustrated in FIG. 2 . In using the cost ellipses 30 to sort route sets, the origin and destination nodes, X and Y, are placed at the two foci and paths along intermediate nodes are sorted according to cost as determined by an acceptable model. Transport cost models are well known in the art and a number of good models are publicly available. Any path having intermediate nodes which fall between the same elliptical cost boundaries is considered to be of comparable cost. For example, the paths x-d-y and x-f-y in FIG. 2 are of comparable cost and are considered as equal alternatives.
FIG. 3 is a schematic diagram of an example network for illustrating the route sets computed by the network control element 26 . Each node control element 28 is provided with a list of candidate routes to each destination. The list from node 0 to node 11 includes a direct route, a set of first-choice routes and a set of second-choice routes, etc. The list includes only the first adjacent node along the shortest path to the destination. Routes from each origin to the destination are determined according to cost criteria described above. The routes are sorted according to static cost and assigned a selection priority. Each network node control element 28 maintains a table of routes received from the network control element 26 . Whenever network topology changes, the network control element 26 determines which links 24 are affected by the change and recomputes network routing sets accordingly. In order to conserve time and ensure that nodes use effective routing sets, only those links 24 affected by a change in network topology are recomputed. When a new route set is recomputed for any particular network node 22 , the recomputed route set is preferably transferred immediately to the associated node control elements 28 .
FIG. 4 shows an exemplary routing table computed by the network control element 26 for the destination 11 from each of the other 10 nodes in the network. As is apparent, a direct route is specified whenever it is available. The direct route is always preferred in traffic routing if free capacity exists on that route. As an alternative to the direct route, a first set of lowest-cost routes is specified. For example, from node 0 to node 11 , the first alternate set includes nodes 5 and 6 . The network control element 26 specifies only the immediately adjacent node for route selection. As will be explained below, during traffic admission the node control elements 28 select the two immediate links which are least occupied to find a route to service an admission request.
In a multi-class network in accordance with the invention, network traffic is divided into a manageable number of classes, whose definition preferably depends on:
1) the transaction format (synchronous transfer mode (STM), asynchronous transfer mode (ATM), Internet protocol (IP), etc.);
2) the method of transaction processing, e.g., connection-oriented or connectionless; or
3) the method of flow control (open-loop or closed-loop).
The term “transaction” as used in this document is to denote the process of transferring information from a source to a sink in a single session. A class may include several connections of similar traffic or may represent a single connection which has a high bit-rate requirement. A class may also include connectionless traffic with no quality of service (QOS) requirements.
FIG. 5 shows the links 24 of a network node 22 partitioned into a plurality of bands, each of which supports one class of traffic. The total capacity of each link 24 is divided among the classes it supports. The links 24 may be partitioned differently since the same mix of traffic is not necessarily transported over each link. Different routing schemes and admission criteria may be applied to the various network bands. For example, a voice service class may use a simple routing scheme while classes of higher-speed connections may use an elaborate state-dependent selective routing scheme as will be explained below in some detail. In addition to the difference in routing and admission criteria, operational measurements, tariff setting and billing procedures may differ among the classes of traffic.
In order to maximize transport efficiency and minimize processing load, at least certain classes of traffic preferably use paths through the network for traffic routing. FIG. 6 schematically illustrates a relation between a path and a connection. In FIG. 6, a solid line through a node indicates a path 32 between non-adjacent nodes and the line connecting nodes indicates a connection 34 . A path and a connection may exist on the same link at the same time and within the same class. A path 32 is a reserved route between two nodes 22 , possibly traversing several intermediate nodes 22 . Intermediate nodes 22 in a path are involved in the path allocation process only when the path is first established or when its capacity allocation is modified. A path 32 may accommodate a large number of connections, possibly several hundreds, between its origin and destination nodes. The originating node 22 views the path as a direct connection to the destination node 22 . The intermediate nodes 22 in a path are not involved in the admission of the individual connections belonging to the path 32 . A path 32 may serve more than one class of traffic. However, the class definition is only relevant to the end nodes 22 .
A connection 34 seeks admission at a specific ingress point in the network. A connection specifies a destination, but there is no fixed route between the originating node and the destination node of the connection. Rather, a route is negotiated when the connection is set up. Each node 22 traversed by a connection is involved in the interrelated decision regarding the admission, or otherwise of the traffic admission request for a connection and the actual selection of the end-to-end route for the request.
Paths and connections may or may not have a capacity reservation. A capacity reservation is necessary to achieve a specified QOS. Without a capacity reservation, the QOS is based only on a weighted priority, or some other class differentiation, and the path 32 or connection 34 are used only to facilitate the forwarding of packets at the nodes.
As shown in FIG. 7, paths maximize processing throughput since admission control may be handled exclusively by an edge node which receives a traffic admission request. Establishing paths, however, is not the most efficient use of network resources unless adequate stable traffic exists to keep the path full. In general as shown in FIG. 7, transport efficiency decreases as the paths' allotment in the network increases. Conversely, transport efficiency increases with the increase in the connections' allotment, however processing throughput is significantly affected.
In the network 20 in accordance with the invention, flexible controls which permit two degrees of freedom are realized by employing adaptive routing in addition to adaptive network partitioning. The two degrees of freedom are depicted in FIG. 8 which illustrates the intra-band and inter-band controls that may be used in a network 20 in accordance with the invention. Within each network band 36 , adaptive alternate routing may be used to balance the traffic intensity across the network and thereby increase the efficiency of the band. The elastic boundaries of a band 36 may vary slowly, typically in seconds, between successive changes while adaptive routing is applied on a per-connection basis. The two degrees of freedom compliment each other to ensure a balanced, efficient network. The principal control element within a band is the routing scheme. State-dependent routing results in load distribution across the network band. The load distribution is further improved with selective state-dependent routing.
As will be explained below, the network nodes 22 use rate controllers to divide the capacity of each link among the network bands 36 in accordance with predefined rules. Because a large proportion of connections traverses more than one link 24 in the network 20 , the rate allocations for the bands cannot be done independently at each node. The rate allocations must be coordinated amongst the nodes in order to ensure that the physical constraints of the link capacity are observed and that end-to-end service requirements are met.
As described above, a network band 36 may include both paths 32 and connections 34 . Low bit-rate admission requests which occur at high frequency are prime candidates for paths 32 . High bit-rate connections which are requested at a low frequency are better served by independent connections 34 . By appropriately selecting path sizes, and with proper splitting of traffic between paths 32 and connections 34 , a network divided into bands 36 with elastic boundaries can be almost as bandwidth-efficient as a fully shared network, while call processing load is reduced and QOS differentiation is facilitated. The word “bandwidth” as used in this document is intended to denote capacity in bits/second.
The prior art approach to configuring a communications network has been to seek an optimal trade-off between transport efficiency and processing efficiency. Consequently, traffic was divided between a set of paths 32 and connections 34 . Paths 32 consume less processing resources than connections 34 . However, due to the random fluctuations of traffic intensity, a path 32 may occasionally suffer from low utilization. This is particularly the case for low-intensity traffic streams which are normally quite variable in their volume. Connections 34 require more processing capabilities due to the signaling load and processing at one or more intermediate nodes 22 .
The traffic efficiency of a path 32 can be increased by allowing limited queuing of traffic admission requests at edge nodes. Normally, if a path 32 does not have sufficient free capacity to accommodate a traffic admission request, the traffic admission request is either overflowed to a connection band or it is refused. However, permitting traffic admission requests to wait until a sufficient free capacity in the designated path becomes available, or a time-out threshold is reached, significantly improves the path utilization while decreasing overall network processing effort. A compromise arrangement in accordance with the invention is to use paths 32 to reduce processing effort combined with a shared capacity allocation for connections 34 . Such an arrangement is shown in FIG. 9 . Traffic admission requests that occur too infrequently to justify establishing a path 32 may use the connections allocation. As shown in FIG. 9, several paths are permitted to overflow to the connection allocation which may be within the same network band 36 . Each of the paths shown in FIG. 9 is sized to accommodate most of the traffic between its end nodes. At the connection level, traffic admission requests allocated to a path may overflow to the shared connection allocation if the path cannot accept the admission request. At the data level, packet-type connection traffic may use vacant time slots allocated to paths, as illustrated in FIG. 10 a . This significantly increases the traffic capacity of the link and brings the overall bandwidth efficiency closer to that of a fully-shared link without affecting the path's performance. The optimal splitting of a link capacity between paths and connections is determined dynamically to follow the traffic load variation.
FIG. 10 b shows a preferable pattern of partitioning the network transport capacity among the network links. End-to-end paths 32 are used for direct connections, and are established whenever the end-to-end traffic volumes exceed a certain threshold. The remaining capacity in each link, if any, is divided into bands, each of which corresponds to a traffic class. The capacity of each band is dynamically adjusted by the connection-admission process. The capacity of a band increases with each new connection admission, and decreases with each connection departure. Any leftover capacity is used for connectionless-type traffic. The arrows in FIG. 10 b indicate that packets belonging to connections of any traffic class may exploit the unused time slots allocated by the rate controller to any path. The reverse is not allowed; packets belonging to a path may not be transmitted during unused time slots allocated by the rate controller to any connection class.
In order to ensure that each traffic class is guaranteed a minimum service rate, it is necessary to provide some form of service-rate controller at the link level. In accordance with the invention there is provided a link service-rate controller shown in FIG. 11 and generally referred to by the reference 50 . The combined service-rate allocations for all classes of traffic being served by an egress link must satisfy the condition: 0 < f j = F j R < 1 , j = 0 , … , K - 1 , with ∑ j = o K - 1 f j < 1
wherein:
K is the number of classes;
R is the link rate in bits per second; and
F j is the required service allocation for class j in bits per second; and
f j is the normalized service rate for class j.
Since the allocated service rate per class is less than the link rate, and since it is not possible to transfer a fraction of a packet at any time, it is necessary to wait for several clock cycles to be able to transfer a first packet from a given class buffer. In the link service-rate controller shown in FIG. 11, which shows four classes (K=4), a clock pulse transferred on a clock line 52 provides a clock signal to sampling frequency circuits 54 . The clock pulse on clock line 52 is regulated to a predetermined nominal packet size, preferably equal to the minimum sized packet transfer rate of a link 24 served by the link service-rate controller 50 . Other clock speeds may also be used. Consequently, the clock pulse can be set to a rate which is some integer multiple of the minimum size packet transfer rate.
Each sampling frequency circuit 54 includes a memory register which stores a class service allocation represented by the character “Δ”. This is, hereafter, called the class credit. The value of Δ is dynamically computed for each of classes 0 through K−1. The class service allocation Δ is preferably a floating point number between 0 and 0.99. When a connection admission request is accepted into a class band, an equivalent bit rate (EBR) normalized to the link capacity is added to the value of Δ. When the connection is released, the normalized EBR is subtracted from Δ. The process for computing EBR is described below in detail.
The credit Δ for a given class is the ratio of the required service rate of the class (occasionally called the “bandwidth of the class”) divided by the capacity of the link under consideration. For example, the credit Δ of a class requiring a 100 Mb/sec in a link of capacity 620 Mb/sec is approximately:
Δ≈0.16.
Note that Δ is dimensionless.
The accumulated credit for a given class is to be compared with the normalized packet size. The normalized packet size is the packet length (in bytes, say) divided by a nominal packet size (64 bytes, say) which is applied uniformly for all classes traversing a link. Preferably, the normalized packet size should be standardized across the network using a value of 64 bytes, for example.
Each time a clock signal is received by the sampling frequency circuit 54 , the value of Δ stored in the memory register is added by a adder 56 to a memory register which accumulates a class allocation sum. A comparator 58 compares the class allocation sum with the “normalized packet size” 64 . If a class buffer 62 is empty, the class allocation sum is set to zero.
FIG. 12 shows a schematic representation of the transmission of packets of variable size. At a top of the figure, a schematic representation of clock cycles is shown. At each clock cycle δ, which equals the transfer time for a predetermined nominal packet size, the value Δ is transferred from the sampling frequency circuit 54 (FIG. 11) to the adder 56 . At each clock signal, the comparator 58 compares the value of the memory register in adder 56 with the normalized packet size 64 .
The accumulated credit in the adder 56 is stored in the memory register of the corresponding comparator 58 and used for comparison with the contents of adder 56 memory register. When the accumulated sum in the adder 56 is greater than or equal to the normalized packet size 64 , a selector 66 writes an eligible class number 68 in the ready queue 60 and the comparator 58 subtracts the normalized packet size 64 from the accumulated sum in the adder 56 so that the balance is added to the class allocation A at the next clock signal, as shown in the table in FIG. 12 . When an eligible class number 68 arrives at the head of the ready queue 60 , the link service-rate controller 50 selects a packet at a head of the corresponding class buffer 62 and transmits that packet over the link.
If the ready queue 60 becomes empty because there are no classes with a specified QOS to be transferred, traffic without a specified QOS is transferred until another class number 68 appears in the ready queue. In order to ensure equitable treatment, a rotating pointer is preferably used to track a next class to be served when the ready queue 60 is empty.
The traffic transferred through the network is preferably classified by the node control elements 28 into three types: connection-based traffic with a specified QOS; connection-based traffic without a specified QOS; and connectionless traffic without a specified QOS. Each node control element preferably monitors the amount of the connection-based traffic without a specified QOS and assigns it an appropriate service rate if there is an appreciable amount of that type of traffic and there is unused capacity on the link. If the link capacity is required by traffic with a specified QOS, however, the service rate is withdrawn from that traffic.
As noted above, an important aspect of the invention is the distributed control of routing through the network. The network in accordance with the invention preferably supports a plurality of routing disciplines. The preferred routing disciplines are:
1) shortest path hop-by-hop routing;
2) selective routing by a conservative scheme; and
3) selective routing by a true state scheme.
Preferably, the different routing disciplines are assigned to different classes in order to best serve the requirements of the class.
In the shortest path hop-by-hop routing, each node has a list of candidate routes to a destination. The list includes a direct route, if one exists, a set of first-choice routes, and a set of second-choice routes, etc. As described above, the list includes only the next node 22 to a destination along the shortest path. The routes from origin to each destination are determined according to cost criteria, as also described above. Each node only maintains information about the occupancy of its outgoing links. When a new traffic admission request is received at a node 22 , the node control element 28 first checks the occupancy of its outgoing link associated with its direct route, if one exists. If the direct route is full or not available, the node control element 28 compares the occupancy state of the outgoing links of the first-choice set of routes and selects the most vacant route. If the available capacity is still not sufficient to accommodate the new traffic admission request, the second-choice set of routes is inspected, and so on. The number of hops to a destination using a given egress port is known by the node control element 28 . The edge node control element 28 therefore assigns a number of “route selection credits” to a traffic admission request which is equal to the number of hops along path selected by the edge node to the destination, plus 2 to allow some variation in downstream route selection to accommodate link congestion. The traffic admission request is then forwarded to the next node selected from the routing table. Upon arrival at the next node, the node control element 28 of that node deducts 1 from the route selection credits assigned by the edge node control element 28 , and checks the availability of its link to the shortest path to the destination. Each traversed node 22 subtracts 1 from the route selection credits. By ensuring that the number of remaining hops along the path is not greater that the available route selection credits, and by avoiding a return to the immediately preceding node, the route is guaranteed to be cycle-free. By always looking for the most vacant link in the preferred order, the route is guaranteed to be efficient. Shortest path hop-by-hop routing is best suited for low-bit-rate traffic where strict route optimization is not warranted.
For high-volume low or medium bit-rate traffic where more powerful route optimization is warranted, a conservative routing scheme may be used to route connections through the network 20 in accordance with the invention. A conservative routing scheme for ATM networks was published by M. Beshai and J. Yan in November of 1996 at the International Network-Planning Symposium in Sydney, Australia in a paper entitled “Conflict-free Selective Routing in an ATM Network”. In accordance with the conservative scheme, when a traffic admission request is received at an edge node 22 , the node control element 28 computes an EBR for the connection and examines the availability of its outgoing links in the preferred order to determine which link(s) can accommodate the traffic admission request. On locating at most two available links with adequate bandwidth, the node control element 28 deducts the EBR from the available capacity of each link, computes the route selection credits for the traffic admission request message and forwards the traffic admission request message to the next node(s) in the route path(s). Meanwhile, other traffic admission requests permitted to use the conservative routing scheme are allowed to proceed, even though the prior traffic admission request may be denied at some other point in the network and, consequently, the available capacity of the link(s) may not reflect the true state of the link's current usage. Since only relatively low or medium bit-rate connections use this scheme, the waste of network resources is minimal. The purpose of the conservative routing scheme is to find a lowest-cost route for the connection in a reasonable time without sacrificing too many network resources.
The third routing discipline is a true-state scheme in which traffic admission requests are processed sequentially and, while a true-state connection is being set up, no other traffic admission request is permitted to proceed in the same class of service. A true-state routing scheme for an ATM switching network is described in applicants' U.S. Pat. No. 5,629,930 which issued on May 13, 1997.
When a traffic admission request is received at an edge node and the traffic admission request is determined to belong to a class of service which requires true-state routing, all other traffic admission requests in that class of service are held until a connection for the request is established or denied. In true-state routing, the node control element 28 searches its links in the preferred order for the two links which have the highest free bandwidth to serve the request after the EBR for the connection request is computed. If a link(s) is found, the route selection credits are computed for the traffic admission request and the request is forwarded to a next node(s) in the route. Thereafter processing proceeds as described above until the connection is established or denied because of a lack of link capacity at some point in the route. While the true-state scheme has the advantage of admission given the true bandwidth capacity of the available link(s), it has the disadvantage of delaying the progress of other connections in the same class. Note that connection admission processing for other classes can proceed while a connection belonging to the true-state class, if any, is being processed.
It is estimated that in a typical case about 300 conservative scheme traffic admission requests can be processed per second assuming a processing time of about 1 millisecond per request. For a processing true-state routing, it is estimated that only about 20 requests per second may be processed for an average link length of about 200 kilometers.
Preferably, a network 20 in accordance with the invention uses a hybrid scheme in which true-state routing coexists with conservative routing and shortest path routing. In that instance, true-state routing is limited to connections with high EBR values while conservative routing is used for connections with lower EBR values, in order to increase the permissible attempt rate. Hop-by-hop routing is used for lowest EBR values where there is no value in using resources to find a least-cost route.
As described above, the EBR must be computed for each traffic admission request received at an edge node 22 of the network 20 . The value of the EBR is determined by traffic descriptors; QOS; and service rate for the class. The traffic descriptors include a peak rate of emission from the source; a mean rate of emission from the source; and, a mean packet size. These values are generally provided by the source when a traffic admission request is received. In some cases, however, they can only be determined by measurement. A QOS request is submitted with the admission request and defines the delay tolerance and loss tolerance for the connection.
In a single class network, the service rate at an egress port in a node is the entire link rate. In a multi-class, multi-band network where the bands do not share their free time slots the service rate for a class is the capacity allocated to the band associated with the class. Since the service rate fluctuates dynamically, the boundaries between classes are elastic and the capacity per class varies over time. This means that an EBR for a given connection which is computed at a given instant may need to be revised when the band capacity changes. Such recomputation is impractical.
In the method in accordance with the invention, a policy of guaranteed minimum capacity allocation along with sharing among the bands is adopted. The computation of the EBR for a connection in any band can therefore be based on the entire link capacity, thus eliminating the need to revise EBR calculations. When a traffic admission request is accepted, the computed EBR is added to the memory register in the sampling frequency circuit 54 of the link service-rate controller 50 (FIG. 11 ). When a session ends and the connection is torn down, the EBR is deducted from the memory register in the sampling frequency circuit 54 . Thus the size of a band 36 for a class of traffic fluctuates with traffic load. The EBR is readily calculated using, for example, the extended Gibbens-Hunt formula which is known in the art. The computation is preferably completed in the edge node while new traffic admission requests are queued for treatment, as shown in FIG. 13 . If the EBR is calculated while the traffic admission request is queued, traffic admission request delay is reduced. In accordance with the method described above for computing EBR, the EBR is dependent on link capacity. It is therefore necessary when setting up a connection through several nodes 22 to compute an EBR at each intermediate node. In order to accomplish this, prior art methods forwarded the traffic descriptors and QOS along with a traffic admission request message, and each subsequent node involved in the admission request recomputed the EBR using the extended Gibbens-Hunt formula which is known in the art. Other methods can also be used. For example, the EBR can be calculated using the Buffet-Duffield formula, as described in U.S. patent application Ser. No. 08/723,649 filed Oct. 3, 1996.
In accordance with the methods of the invention, recomputation is minimized and connection request processing is facilitated by computing parameters which are forwarded with traffic connection request messages that permit subsequent nodes to rapidly compute approximate EBRs. The approximate EBRs are adequately accurate to permit connections to be established with a high level of quality assurance. In accordance with the method, in order to reduce the computational effort, interpolation is used to derive approximate EBRs at subsequent links involved in the processing of traffic admission requests. In a method in accordance with the invention, a hyperbolic interpolation is used to yield a reliable approximation for EBR based on link capacity. Other types of interpolators may be used which could produce equally good results.
FIG. 14 shows a graph of a hyperbolic interpolator in accordance with the invention. Using the interpolator, when an edge node 22 receives a traffic admission request, it computes an EBR value for the connection using the capacity R 1 of one of the links which the node control element 28 found to have adequate free capacity for the admission connection request. Thereafter, the node control element computes values for Ω ∞ , a, and b, and R using the following formulas:
Ω ∞ =γθ;
where
γ is the peak rate of the traffic stream requesting admission to the network; and
θ is the proportion of time that the source is active.
The value of b is computed using the formula: b + γ = ( R 1 - γ ) Ω 1 - Ω ∞ Ω ^ - Ω 1
wherein
R 1 is a selected service rate, as indicated above;
{circumflex over (Ω)} is determined using the Gibbens-Hunt formula, which is well-known in the art; and
Ω 1 is determined using the extended Gibbens-Hunt method described in U.S. patent application Ser. No. 08/723,649 filed Oct. 3, 1996 and entitled ADMISSION CONTROL IN AN ATM SWITCHING NODE, which is incorporated herein by reference. Although the above-referenced application is related only to ATM networks, the methods it teaches are also applicable to unfragmented variable-sized packets.
The value of a is computed using the formula:
a =( b+y )({circumflex over (Ω)}−Ω ∞ ).
The values of Ω ∞ , a and b are then passed in the service admission request message to other nodes involved in connection setup. On receipt of those values, the following formula is used compute the approximated EBR: Ω = Ω ∞ + a R + b
where:
Ω is an approximate EBR; and
R is the link capacity of the link selected in response to the traffic admission request.
Using the formula a node is enabled to compute an approximated EBR with much less computational effort than recomputing EBR using the extended Gibbens-Hunt method or some other similar method. This significantly speeds up traffic admission request processing and thereby enhances overall network efficiency. This method is particularly useful in establishing multicast connections since dozens or hundreds of EBRs may have to be computed in order to establish the multicast connections. Using this method significantly improves the efficiency of processing traffic admission requests for multicast connections.
The invention therefore provides a multi-class network which is capable of transmitting variable-size packets without packet deconstruction. The multi-class network operates efficiently with reliable quality assurance. Since admission control, connection routing and service-rate control are distributed at the node level of the network, control messaging overhead is minimized and network resources are available for transport functions.
Modifications of the above-described embodiments will no doubt become apparent to those skilled in the art. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims. | A multi-class digital network is described. The network supports a plurality of digital services using dynamically-configured service bands to support various transport modes and qualities of service. A network control element receives traffic and network state information from the nodes. The network control element maintains a network topology and uses the network topology to compute route sets for the nodes. The network control element uses the traffic information to compute network size specifications. The switching nodes use rate controllers to divide the capacity of each link among the connection classes according to rules which ensure consistent service attributes for each band across the network. The rate controllers are adapted to support different transport modes and different packet sizes so that the deconstruction and reconstruction of packets at network edge devices is eliminated. The advantage is a flexible multi-class network which dynamically reconfigures to service traffic loads as service demands fluctuate. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No. 12/854,481, filed Aug. 11, 2010, now U.S. Pat. No. 7,997,777, which is a continuation of U.S. patent application Ser. No. 12/037,409, filed Feb. 26, 2008, now U.S. Pat. No. 7,784,983, which is a continuation of U.S. patent application Ser. No. 11/505,268, filed on Aug. 16, 2006, now U.S. Pat. No. 7,334,925, which is a continuation of U.S. patent application Ser. No. 10/287,565, filed Nov. 4, 2002, now U.S. Pat. No. 7,140,755, which is a continuation of U.S. patent application Ser. No. 09/938,182, filed on Aug. 23, 2001, now U.S. Pat. No. 6,474,853, which is a continuation of U.S. patent application Ser. No. 09/630,332, filed on Jul. 31, 2000, now U.S. Pat. No. 6,280,069, which is a continuation of U.S. patent application Ser. No. 09/420,658, filed on Oct. 19, 1999, now U.S. Pat. No. 6,099,155, which is a continuation of U.S. patent application Ser. No. 09/232,316, filed on Jan. 18, 1999, now U.S. Pat. No. 6,074,077, which is a continuation of U.S. patent application Ser. No. 08/934,490, filed on Sep. 19, 1997, now U.S. Pat. No. 5,863,116, which is a continuation of U.S. patent application Ser. No. 08/607,285, filed on Feb. 26, 1996, now U.S. Pat. No. 5,669,705, which is a continuation of U.S. patent application Ser. No. 08/333,412, filed on Nov. 2, 1994, now U.S. Pat. No. 5,497,305, which is a continuation of U.S. patent application Ser. No. 08/011,947, filed on Feb, 1, 1993, now U.S. Pat. No. 5,371,659.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to security systems for vehicles and, more particularly, to remotely actuated, personal safety lighting systems. The invention is particularly adapted to incorporation in the exterior mirrors of a vehicle.
[0003] Personal security in and around vehicles has become an important concern. In particular, an increasing number of assaults and robberies are committed in parking lots while occupants are entering and exiting vehicles. While remote-operated, keyless entry systems have been incorporated in vehicles in order to unlock the vehicle and illuminate interior lights, such systems merely expedite entry to the vehicle and do not, per se, enhance security around the vehicle. Accordingly, a need exists for a vehicle security system to increase the security for vehicle occupants while entering and exiting the vehicle. Any such system would need to be aesthetically pleasing and not burdensome in use.
SUMMARY OF THE INVENTION
[0004] The present invention is intended to provide a personal safety feature for a vehicle in the form of a floodlight adapted to projecting light generally downwardly on an area adjacent a portion of the vehicle in order to create a lighted security zone in the area. Advantageously, the floodlight is preferably positioned in the housing of an exterior mirror having a reflective element also positioned in the housing, According to an aspect of the invention, an actuator is provided for the floodlight including a base unit in the vehicle and a remote transmitter. The base unit is responsive to a signal from the remote transmitter in order to actuate the floodlight. This allows the vehicle operator to actuate the floodlight from a distance in order to establish the security zone prior to approaching the vehicle.
[0005] According to another aspect of the invention, an actuator for the floodlight includes a lockout device in order to prevent actuation of the floodlight during operation of the vehicle. According to yet a further aspect of the invention, a signal light that is adapted to projecting light generally rearwardly of the vehicle is included in the exterior mirror housing. An actuator for the warning light is connected with the stoplight circuit, turn signal circuit, or both the stoplight and turn signal circuit, of the vehicle in order to actuate the warning light when either the stoplight or turn signal is being actuated.
[0006] According to yet another aspect of the invention, the floodlight is adapted to projecting a pattern of light from the housing on an area adjacent a portion of the vehicle that extends laterally onto the vehicle and downwardly and rearwardly of the vehicle. In this manner, a security zone is established from the vehicle door to the rear of the vehicle. The signal light is adapted to projecting a pattern of light extending laterally away from the vehicle and rearwardly of the vehicle. In this manner, the pattern generated by the signal light cannot be substantially observed by a driver of the vehicle. However, the pattern generated by the signal light may be observed by a driver of another vehicle passing the vehicle equipped according to the invention.
[0007] The floodlight and signal lights may be generated by a light emitting diode positioned in the housing, a vacuum fluorescent lamp positioned in the housing, an incandescent lamp positioned in the housing or a light source in the vehicle and a light pipe between the light source and the mirror housing.
[0008] By providing a lighted security zone adjacent the vehicle, users can observe suspicious activity around the vehicle. The pattern of light generated by a security light according to the invention establishes a security zone around, and even under, the vehicle in the important area where the users enter and exit the vehicle. The provision for remote actuation of the security light provides a deterrent to ward off persons lurking around the protected vehicle while the users are still at a safe distance from the vehicle. The provision for a lockout circuit ensures that the security light will not inadvertently be actuated while the vehicle is in motion. The invention, further, conveniently combines a signal light that acts in unison with the vehicle's turn signal, brake light, or both, with the security light in an exterior mirror assembly. The signal light may be designed to be observed by other vehicles passing the equipped vehicle but not directly by the driver of the equipped vehicle.
[0009] These and other objects, advantages and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view taken from the front of a mirror assembly (rear of the vehicle) incorporating the invention;
[0011] FIG. 2 is a rear view of the mirror assembly in FIG. 1 ;
[0012] FIG. 3 is a top view of the mirror assembly in FIG. 1 ;
[0013] FIG. 4 is the same view of FIG. 1 of an alternative embodiment of the invention;
[0014] FIG. 5 is a block diagram of a control system according to the invention;
[0015] FIG. 6 is a block diagram of an alternative embodiment of a control system according to the invention;
[0016] FIG. 7 is a breakaway perspective view of the system in FIG. 1 revealing internal components thereof;
[0017] FIG. 8 is a sectional view taken along the lines VIII-VIII in FIG. 7 ;
[0018] FIG. 9 is a sectional view taken along the lines IX-IX in FIG. 7 ;
[0019] FIG. 10 is a side elevation of a vehicle illustrating the security zone light pattern generated by a security light according to the invention;
[0020] FIG. 11 is a top plan view of the vehicle and light pattern in FIG. 10 ;
[0021] FIG. 12 is a rear elevation of the vehicle and light pattern in FIG. 10 ;
[0022] FIG. 13 is a side elevation of a vehicle illustrating the light pattern generated by a signal light useful with the invention;
[0023] FIG. 14 is a top plan view of the vehicle and light pattern in FIG, 13 ;
[0024] FIG. 15 is a rear elevation of the vehicle and light pattern in FIG. 13 ;
[0025] FIG. 16 is the same view as FIG. 7 of a first alternative light source according to the invention;
[0026] FIG. 17 is the same view as FIG. 7 of a second alternative light source;
[0027] FIG. 18 is the same view as FIG. 7 of a third alternative light source;
[0028] FIG. 19 is the same view as FIG. 7 of a fourth alternative light source; and
[0029] FIG. 20 is the same view as FIG. 7 of the invention embodied in an alternative mirror structure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Referring now specifically to the drawings, and the illustrative embodiments depicted therein, a vehicle personal security lighting system 25 includes an exterior mirror assembly 26 having a conventional reflectance element 28 , a security light 30 , preferably white, or clear, and a signal light 32 , preferably red, incorporated in a housing, or casing, 34 . Casing 34 is connected by a neck 36 to a stationary panel or sail 38 adapted for incorporation with the forward portion of the vehicle side window assembly, and which mounts mirror assembly 26 to the door of a vehicle 40 (see FIG. 10 ). Reflectance element 28 may be any of several reflectors, such as glass coated on its first or second surface with a suitable reflective layer or layers, such as those disclosed in U.S. Pat. No. 5,179,471, the disclosure of which is hereby incorporated by reference herein, or an electro-optic cell including a liquid crystal, electrochromic, or electrochernichromic fluid, gel or solid-state compound for varying the reflectivity of the mirror in response to electrical voltage applied thereacross as disclosed in U.S. Pat. No. 5,151,824, the disclosure of which is hereby incorporated by reference herein.
[0031] With reference to FIGS. 7 and 8 , as is conventional, reflectance element 28 is mounted to a bracket 43 by an actuator 42 . Casing 34 is mounted to bracket 43 . Actuator 42 provides remote positioning of reflectance element 28 on two orthogonal axes. Such actuators are well known in the art and may include a jackscrew-type actuator 42 such as Model No. H16-49-8001 (right-hand mirror) and Model No, H16-49-8051 (left-hand mirror) by Matsuyama of Kawagoe City, Japan, as illustrated in FIG. 7 , or a planetary-gear actuator 42 ′ such as Model No. 540 (U.S. Pat. No. 4,281,899) sold by Industrie Koot BV (IKU) of Montfoort, Netherlands, as illustrated in FIG. 20 . As is also conventional, the entire casing 34 including actuator 42 , 42 ′ is mounted via bracket 43 for breakaway motion with respect to stationary panel 38 by a breakaway joint assembly 44 . Breakaway joint assembly 44 ( FIG. 9 ) includes a stationary member 46 attached to vehicle 40 , a pivoting member 48 to which bracket 43 and casing 34 are attached, and a wire-way 50 through which a wire cable 52 passes. Wire cable 52 includes individual wires to supply control signals to actuator 42 , 42 ′, as well as signals to control the level of reflectivity, if reflective element 28 is of the variable reflectivity type noted above, such as an electrochromic mirror. Power may also be supplied through cable 52 for a heater 53 as disclosed in U.S. Pat. No. 5,151,824 in order to evaporate ice and dew from reflective element 28 .
[0032] With reference to FIG. 5 , actuator 42 , 42 ′ receives a first set of reversible voltage signals from a switch 54 , in order to bidirectionally pivot in one axis, and a second set of reversible signals from a switch 56 , in order to bidirectionally pivot in the opposite axis, as is conventional. Switches 54 and 56 are actuated by a common actuator (not shown) that is linked so that only one of the switches 54 and 56 may be actuated at a time. In this manner, actuator 42 , 42 ′ may utilize one common conductor for both switches 54 , 56 .
[0033] Each of the security light 30 and signal light 32 includes a light source 60 and reflector 62 behind a lens 64 ( FIG. 8 ). Light source 60 , reflector 62 and lens 64 are designed for security light 30 to project a pattern 66 of light, such as white light, through a clear, non-filtering lens, in order to establish a security zone around the vehicle ( FIGS. 10-12 ). Pattern 66 extends rearward from mirror assembly 26 . Vertically, pattern 66 contacts the ground at 68 in the vicinity of entry and exit by the vehicle occupants ( FIGS. 10 and 12 ). Laterally, pattern 66 fans out into contact with the side 70 a, 70 b of the vehicle. This contact washes the sides of the vehicle to reflect the light in order to further illuminate the area in order to establish the security lighting zone ( FIGS. 11 and 12 ). In a preferred embodiment, pattern 66 extends rearwardly from mirror assembly 26 without projecting any portion of the pattern forwardly of the mirror assembly.
[0034] Signal light 32 generates a light pattern 72 , which is directed generally horizontally rearwardly of vehicle 40 ( FIGS. 13-15 ). Pattern 72 is laterally directed substantially away from side 70 a, 70 b of vehicle 40 so that the driver of vehicle 40 does not directly intercept pattern 72 , although a minor intensity (such as 10%) of the pattern is intercepted by the driver in order to provide awareness of the actuating of the signal light. Pattern 72 fans laterally away from side 70 a, 70 b to an extent that is parallel the face of reflectance element 28 , which is substantially perpendicular to side 70 a, 70 b ( FIG. 14 ). Thus, the driver of another vehicle (not shown) passing vehicle 40 on the left or right side of vehicle 40 will intercept pattern 72 while the vehicle is behind and beside vehicle 40 . Although, in an illustrated embodiment, lens 64 of signal light 32 is substantially planar, lens 64 of signal light 32 could be made to wrap around the outward side of casing 34 in order to function as a side marker for the vehicle as is required in some European countries.
[0035] Vehicle mirror assembly security system 25 is actuated by a control system 74 ( FIG. 5 ). Control system 74 includes means for actuating security light 30 including a remote transmitting device 76 and a stationary receiving device 78 . Transmitting device 76 may be remotely carried by the vehicle operator and includes switches 80 and 81 in order to actuate the transmitting circuitry to transmit a signal form antenna 82 , which is received by antenna 84 of receiving device 78 . Receiving device 78 is mounted in the vehicle, such as in the vehicle trunk compartment, and includes an output 86 in order to operate remote door lock circuit 88 , as is conventional. Output 86 is, additionally, provided as an input 90 of a lockout circuit 92 , whose output 94 is supplied to security lamp 30 . Input 90 may additionally be actuated by a timeout circuit 96 , which is conventionally supplied in a vehicle in order to dim the interior lights, following a slight delay, after the occurrence of an event, such as the opening and closing of the doors of the vehicle. Signal light 32 is actuated on line 98 from either a turn indicator circuit 100 or a stop lamp indicator circuit 102 , both of which are conventionally supplied with vehicle 40 .
[0036] In operation, when the operator actuates switch 80 of transmitting device 76 , receiving device 78 produces a signal on output 86 in order to cause remote door lock circuit 88 to unlock the doors. Alternatively, actuation of switch 81 on remote transmitting device 76 causes receiving device 78 to produce a signal on output 86 to cause remote door lock circuit 88 to lock the vehicle doors. The signal on output 86 actuates security lamp 30 provided that lockout circuit 92 does not inhibit the signal. Lockout circuit 92 responds to operation of the vehicle in order to avoid actuation of security lamp 30 when the vehicle is in motion. Such lockout circuits are conventional and may be responsive to placing of the vehicle transmission in gear of sensing of the speed of the vehicle, or the like. Security lamp 30 is also actuated, in response to interior lighting device timeout circuit 96 , whenever the interior lights of the vehicle are being actuated by timeout circuit 96 , provided that lookout circuit 92 does not inhibit the signal from security lamp 30 . This is provided in order to allow security lamp 30 to be actuated in response to the entry to, or exit from, vehicle 40 without the operator utilizing transmitting device 76 to lock or unlock the doors. Signal lamp 32 is actuated in response to turn indicator circuit 100 whenever the operator moves the indicator stick in the direction of that particular signal lamp 32 . Signal lamp 32 may additionally be actuated from stop lamp circuit 102 in response to the driver actuating the vehicle's brakes.
[0037] In the embodiment illustrated in FIGS. 1 and 5 , lens 64 of signal lamp 32 is adapted to filter the light provided from lamp 32 so as to be red and is provided for vehicles 40 in which the stop lamps and rear turn indicator lamps are, likewise, red, Because signal lamp 32 shines red, pattern 72 is restricted from extending forward of the vehicle. This is in order to comply with regulations prohibiting red lights from causing confusion with emergency vehicles by shining forward of the vehicle.
[0038] For vehicles having red stoplights and amber turn indicators in the rear, a vehicle mirror security assembly 25 ′ includes an exterior mirror assembly 26 ′ and a control system 74 ′ ( FIGS. 4 and 6 ). Exterior mirror assembly 26 ′ includes a security light 30 ′, preferably white or clear, and a pair of signal lights 32 a ′ and 32 b ′. Signal light 32 a ′ is amber and is actuated directly from turn indicator circuit 100 ′. This amber color can be provided either by an amber light bulb or source, or a filtering lens providing an amber color. Signal light 32 b ′ is red and is actuated directly from stop lamp circuit 102 ′. Each of the light patterns generated by signal lights 32 a ′ and 32 b ′ substantially correspond with light pattern 72 . The light pattern generated by security light 30 ′ is substantially equivalent to pattern 66 . With the exception that turn signal indicator circuit 100 ′ actuates signal light 32 a ′ and stop lamp circuit 102 ′ actuates signal light 32 W, control system 74 ′ operates substantially identically with control circuit 74 .
[0039] In the illustrated embodiment, light source 60 , for both security light 30 and signal light 32 , may be supplied as a conventional incandescent or halogen lamp 60 a (FIG, 7 ). Alternatively, a conventional incandescent fuse lamp 60 b may be used ( FIG. 16 ). Alternatively, a vacuum fluorescent lamp 60 c, which is available in various colors, may be used ( FIG. 17 ). Alternatively, a light emitting diode 60 d may be used ( FIG. 18 ). As yet a further alternative, a fiber optic bundle 104 forming a light pipe may be positioned to discharge light behind lens 64 . Fiber optic bundle 104 passes through breakaway joint 44 in wire-way 50 in order to transmit light from a source (not shown) within vehicle 40 . By way of example, lens 64 may be supplied as a segmented lens, a prismatic lens, or a Fresnel lens in order to generate light patterns 66 and 72 . Bracket 43 and breakaway joint 44 are marketed by Donnelly Corporation, the present assignee, of Holland, Mich. The remote actuator composed of remote transmitting device 76 and stationary receiving device 78 may be radio frequency coupled, as is conventional. Alternatively, they may be infrared coupled as illustrated in U.S. Pat. No. 4,258,352.
[0040] Although the invention is illustrated in a mirror assembly utilizing an automatic remote actuator, it may also be applied to manual remote actuators and handset actuators. As previously set forth, reflectance element 28 may be conventional or may be supplied as an electrochromic self-dimming mirror. Although the invention is illustrated with breakaway joint 44 , the invention may also be applied to mirrors that are rigidly mounted to the vehicle.
[0041] Changes and modifications in the specifically described embodiments can be carried out without departing form the principles of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the Doctrine of Equivalents. | A lighted exterior rearview mirror system includes an exterior rearview mirror assembly including a reflective element and an electrically-operable actuator. The exterior rearview mirror assembly includes a breakaway joint assembly. The reflective element has an electrically powered heater operable to remove ice or dew from the reflective element. The exterior rearview mirror assembly includes a turn signal indicator lamp that has a light source and a lens. The lamp is included in the exterior rearview mirror assembly and unaffected by operation of the actuator. The breakaway joint assembly includes a wire-way through which a wire cable passes. The wire cable includes wires for operating the actuator, the heater and the lamp. The light source includes at least one light emitting diode. | 8 |
FIELD OF INVENTION
[0001] This invention relates to Bicyclic triterpenoid Iripallidal as a novel anti-glioma and anti-neoplastic therapy in vitro.
BACKGROUND OF INVENTION
[0002] Glioblastoma multiformes (GBM) represents one of the most malignant and prevalent brain tumor that still remains incurable. Despite recent advances in understanding molecular mechanisms involved in GBM progression, the prognosis of the most malignant brain tumor continues to be dismal. Iripallidal [(−) (6R,10S,11S,18R,22S)-26-Hydroxy-22-α-methylcycloirid-16-enal NSC 631939] is bicyclic triterpenoid that displays anti-proliferative activity in a NCI 60 cell line screen both at micromolar to nanomolar range. It binds to RasGRP3, a phorbol ester receptor that links DAG/phorbol ester signalling with Ras activation. It also induces phosphorylation of ERK1/2 in a Ras dependent manner.
[0003] Ras proteins are members of a super family of related small GTPases implicated in cellular proliferation and transformation. Although Ras is usually associated with cell proliferation; growth arrest, senescence or apoptosis in response to activated Ras has also been reported. Ras not only differentially regulates discrete cell death programs through Ras/PKC mediated, but it also induces non-apoptotic cell death in GBM. Proapoptotic effects of Ras are mediated by the MAPK pathway. The major MAPK families include extracellular signal related kinases (ERK), c-Jun N-terminal kinases (JNK) and the p38MAPK. The alkyl phospholipid Perifosine inhibits Ras/ERK signaling pathways to induce apoptosis in gliomas. Besides, ERK activation plays an active role in mediating cisplatin-induced apoptosis of HeLa cells. Ras activation occurs in GBMs, this high level of active Ras has been a target for Ras inhibitors mediated glioma therapy. We therefore evaluated the ability of Iripallidal to induce cell death by modulating Ras.
[0004] Natural products continue to be an important source of chemotherapeutic agents. The plant-derived product is paclitaxel (currently marketed as TAXOL® by Bristol-Myers Squibb Oncology Division) is a classic example of natural products derived chemotherapeutic. Paclitaxel is a natural tubulin binding diterpene product isolated from Taxus brevifolia , inhibiting cancer cell and is an effective as chemotherapy for several types of neoplasms.
[0005] As both Paclitaxel and Iripallidal belong to the terpenoid family and Inventors observed an anti-proliferative effect of Iripallidal on GBM cell lines, Inventors investigated the effect of Iripallidal on the viability of human breast, cervical, liver, colon and acute myeloid leukemia cancer cell lines.
[0006] There is no literature available on the chemotherapeutic effect of Iripallidal on GBM and other cancer cell lines. The unique property of the therapy with Iripallidal is the killing of a wide range of human cancer cell lines without affecting normal human monocytes, in vitro.
[0007] There is no literature available regarding the use of Iripallidal as a therapeutic measure for treatment of glioblastoma, breast, colon, cervical, hepatocellular and cancer of the myeloid origin.
[0008] Extensive in vitro screening of compounds with anticancer activity performed by National Cancer Institute identified more than 70,000 compounds for their antiproliferation activities against a panel of 60 human cancer cell lines. Autodock program revealed that the Iridals dock to the same position on protein kinase C delta as do the phorbol esters. Biological analysis of two iridals, NSC 631939 and NSC 631941, revealed that they bound to (i) protein kinase C alpha (ii) RasGRP3, a phorbol ester receptor that directly links diacylglycerol/phorbol ester signaling with Ras activation. Both compounds induced phosphorylation of ERK1/2, a downstream indicator of Ras activation.
[0009] Besides this nothing is known regarding the effect of Iripallidal on the proliferation of human glioblastoma, breast, colon, cervical, hepatocellular and cancer of the myeloid origin in vitro.
OBJECTS OF THE INVENTION
[0010] The main object is to identify iripallidal as a new chemo-therapeutic agent against glioblastoma multiforme.
[0011] Other object is to identify the ability of Iripallidal to inhibit proliferation of human breast, colon, cervical, hepatocellular and myeloid leukemic cancer cell lines.
[0012] Another object is to overcome the nonspecific chemotherapy, which adversely affects normal cells.
[0013] Yet another object is to identify iripallidal wherein it decreases the proliferation and viability of several human cancer cell lines without effecting normal cells.
STATEMENT OF INVENTION
[0014] This invention relates to a Bicyclic triterpenoid Iripallidal as a novel anti-glioma and anti neoplastic agent in vitro, having the composition [(−) (6R,10S,11S,18R,22S)-26 Hydroxy-22-∝ methylcyloirid-16-enal NSC 631939], wherein it binds to Ras GRP3, a phorbol ester receptor that links DAG/phorbolester signaling with Ras activation and induces phosphorylation of ER K1/2 in a Ras dependent manner, reducing proliferation of cancer cell lines to the extent of 50-70%.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0015] FIG. 1 . Shows the anti-proliferative effect of Iripallidal on glioma cells. Viability of different glioma cell lines treated with Iripallidal was determined by MTS assay. The graph represents the percentage viable cells of control observed when U87MG, A172, LN229 and T98G cells were treated with different concentrations, of Iripallidal for 24 hours. Ctrl-control; I-Iripallidal.
[0016] FIG. 2 . Illustrates Western blot analysis demonstrating expression of Ras in A172 and U87MG cells treated with Iripallidal. A representative blot is shown from three independent experiments with identical results. Blots were reprobed for β actin to establish equivalent loading. C-control; IR1-Iripallidal 20 μM.
[0017] FIG. 3 . demonstrates Effect of Iripallidal on Ras activity. The level of Ras-GTP in protein extracts of control and Iripallidal treated glioma cells was determined by the ability of Ras-GTP to bind to a specific protein domain of Raf in the form of a GST-fusion protein. An increase Ras activity was observed in Iripallidal treated cells as compared to the control. The figure is representative from two independent experiments with identical results. C-control; IR1-Iripallidal 20 μM.
[0018] FIG. 4 . depicts the anti-proliferative effect of Iripallidal on breast, cervical, hepatocellular carcinoma, acute myeloid leukemia and colon carcinoma cell lines. Viability of MCF-7 (breast), HeLa (cervical), HepG2 (hepatocellular carcinoma), THP1 (acute myeloid leukemia), HT-29 (colon carcinoma) cells treated with different doses of Iripallidal for 24 hours was determined by MTS assay. The graph represents the percentage viable cells of control observed when cells were treated with different concentrations of Iripallidal for 24 hours.
Ctrl-control; I-Iripallidal.
[0019] FIG. 5 . Shows iripallidal does not effect the viability of normal human monocytes.
[0020] Graph depicts the effect of Iripallidal on normal human monocytes. Viability of monocytes treated with Iripallidal was determined by MTS assay. The graph represents the percentage viable cells of control observed when cells were treated with different concentrations of Iripallidal for 24 hours. Ctrl-control; I-Iripallidal.
DETAILED DESCRIPTION OF THE INVENTION
[0021] GBM represents one of the most malignant brain tumors and there is no effective treatment for GBM. In addition to inhibiting glioblastoma cell proliferation, Iripallidal also inhibited the proliferation of breast, colon, cervical, liver and cancer of the myeloid origin.
[0022] Results indicate that human glioma cell lines are sensitive to the anti-proliferative effect of Iripallidal and Iripallidal increases both Ras levels and activity in glioma cell lines. These results raise the possibility that Iripallidal may prove effective in the treatment of GBM, by inhibiting its proliferation.
[0023] As both Paclitaxel and Iripallidal belong to the terpenoid family and we observed an anti-proliferative effect of Iripallidal on GBM cell lines, we investigated the effect of Iripallidal on the viability of human breast, cervical, liver, colon and acute myeloid leukemia cancer cell lines.
[0024] Iripallidal decreased the viability of glioblastoma cell lines significantly in vitro. Iripallidal elevated both Ras levels and Ras activity in GBM cell lines. Ras is known to regulate discrete cell death programs through Ras mediated and Fas mediated apoptotic pathways. It also induces non-apoptotic cell death in GBM.
[0025] Inventors have procured Iripallidal from Calbiochem, USA for all our experiments.
[0026] In another embodiment GBM cell lines U87MG, A172, T98G, and LN229 were treated with different concentration of Iripallidal (in Dimethyl sulphoxide, DMSO) in serum free media for 24 hours and cell viability was assessed using the [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] (MTS) assay. Values were expressed as percent cell viability relative to control.
[0027] In another embodiment, protein isolated from glioma cells were treated with Iripallidal and electrophoresed on 6% to 10% polyacrylamide gel, Western blotting was performed and expression of Ras determined as described previously.
[0028] In another embodiment the Ras activity was performed using a commercially available kit from Upstate Biotechnology (Temecula, Calif., USA). Briefly, glioma cell lines (2×10 6 ) treated with Iripallidal were lysed and the cleared lysates were incubated with bead-bound RAS binding domain of Raf-1 protein to precipitate Ras-GTP. The precipitates were subjected to SDS-PAGE and Western blotting. Staining of the blots with a Ras Ab revealed the level of Ras activation in the lysate.
[0029] In another embodiment colon cancer cell line HT29, breast cancer line MCF-7, cervical cancer cell line HeLa, hepatocellular carcinoma cell line HepG2 and acute myeloid leukemic cell line THP1 were treated with different concentration of Iripallidal (in Dimethyl sulphoxide, DMSO) in serum free media for 24 hours and cell viability was assessed using the MTS assay. Values were expressed as a percentage relative to those obtained in controls.
[0030] In another embodiment normal human monocytes were treated with different concentration of Iripallidal in serum free media for 24 hours and cell viability was assessed using the MTS assay. Values were expressed as a percentage relative to those obtained in controls.
[0031] The following examples are given by way of explanation and for illustration only and these examples should not be construed in any manner to limit the scope of invention.
EXAMPLES
Example 1
Cell Culture and Treatment
[0032] Glioblastoma cell lines U87MG, A172, T98G, and LN229; breast cancer cell line MCF7, cervical cancer cell line HeLa, hepatocellular carcinoma cell line HepG2, acute myeloid leukemia THP1, colon carcinoma cell line HT-29 and acute myeloid leukemic cell line THP1 were obtained from American Type Culture Collection and cultured in DMEM supplemented with 10% fetal bovine serum. On attaining semi-confluence, cells were switched to serum free media and after 12 hours, cells were treated with different concentration of Iripallidal (in DMSO) in serum free media for 24 hours. Following treatment, the cells were processed for Western blot analysis. DMSO treated cells were used as controls.
Example 2
Preparation of Peripheral Blood Mononuclear Cells (PBMC) from Normal Human Ex Vivo
[0033] Whole blood (5 ml) was drawn from normal human volunteers and mononuclear cells were separated by Histopaque density gradient centrifugation. Briefly, blood was diluted twice with phosphate buffered saline (PBS) and layered over Histopaque (Sigma, Mo., USA) and centrifuged at 1500 rpm for 20 mins at room temperature. Peripheral blood mononuclear cells (PBMC) were collected carefully at the interface of Histopaque and plasma, diluted five times with PBS and centrifuged at 1500 rpm for 10 mins. PBMC thus pelleted were washed twice with PBS and seeded onto glass petri dishes and allowed to adhere for 3 hrs. Non adherent cells were removed by gentle washing with PBS twice and the adherent monocytes were used in MTS assay.
Example 3
Determination of Viability of Glioblastoma, Breast, Liver, Colon, Myeloid Leukemia Cancer Cell Lines and Normal Human Monocytes Upon Treatment with Iripallidal
[0034] Cell viability was assessed using the [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] (MTS) as described earlier. Following treatment of cancer cells (2×10 3 ) and normal monocytes (10×10 3 ) with different concentrations of Iripallidal for 24 hours in 96-well plates, 20 μl of MTS solution was added. After 4 hours of incubation the absorbance reflecting reduction of MTS by viable cells was determined at 490 nm. Values were expressed as a percentage relative to those obtained in controls.
Example 4
Western Blot Analysis Depicting Increased Ras Levels in Iripallidal Treated Glioma Cells
[0035] Protein from whole cell lysates were isolated as described previously. Twenty to fifty μg of protein isolated from cells treated with Iripallidal was electrophoresed on 6% to 10% polyacrylamide gel. Western blotting was performed and Ras expression was determined as described. The blots were stripped and reprobed with anti-β-actin to determine equivalent loading.
Example 5
Iripallidal Increases Ras Activity in Glioma Cells
[0036] Effect of Iripallidal on the level of GTP-bound Ras. The level of Ras-GTP in protein extracts of control and Iripallidal treated glioma cells was determined by the ability of Ras-GTP to bind to a specific protein domain of Raf in the form of a GST-fusion protein. An increase in Ras activity was observed in Iripallidal treated cells as compared to the control. IR1 denotes Iripallidal. | This invention relates to a Bicyclic triterpenoid Iripallidal as a novel anti-glioma and anti neoplastic agent, having the composition [(−)(6R,10S,11S,18R,22S)-26 Hydroxy-22-α methylcyloirid-16-enal NSC 631939], wherein it binds to Ras GRP3, a phorbol ester receptor that links DAG/phorbolester signaling with Ras activation and induces phosphorylation of ER K1/2 in a Ras dependent manner, reducing proliferation of cancer cell lines to the extent of 50-70%. | 0 |
RELATED APPLICATIONS
[0001] This nonprovisional application is a continuation of U.S. application Ser. No. 12/649,205, filed Dec. 29, 2009, and entitled “Circuit and Method for Distance Measurement Between Two Nodes of a Radio Network,” and claims priority to U.S. Provisional Application No. 61/141,501 filed Dec. 30, 2008, and to German Patent Application No. DE 102008063254.6, filed in Germany on Dec. 30, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system, a circuit, and a method for distance measurement between two nodes of a radio network.
[0004] 2. Description of the Background Art
[0005] In a radio network, it is desirable to locate the nodes of the radio network or to determine at least one distance between the nodes. As a result, for example, a defective node can be easily found. Slow movements of nodes, for example, a means of conveyance in a factory, can also be tracked. It is also possible to use the locating of the nodes in firefighting, when the nodes dropped by an airplane can be located and an increased temperature transmitted.
[0006] International Pat. Appl. No. WO 02/01247 A2 discloses a method for measuring the distance between two objects with the use of electromagnetic waves. An interrogation signal of a base station and a response signal of a portable code emitter are transmitted twice at different carrier frequencies. The carrier frequencies in this case are correlated; i.e., they are dependent on one another. The carrier frequencies are approximated to one another, so that a phase shift between the signals can be measured. The distance of the code emitter to the base station is calculated from this phase shift. The interrogation signal and the response signal can be transmitted at different carrier frequencies or at the same carrier frequencies. The carrier frequencies are altered for a renewed interrogation/response dialog.
[0007] If a transceiver of a node for a sensor network is laid out according to the industry standard 802.15.4 only for a half-duplex instead of for a full-duplex system, it cannot transmit and receive simultaneously. If said transceiver is to be used as an active reflector for phase measurement, the node therefore must store the phase of the received signal, for example, by a phase-locked loop and after switching from receiving to transmitting again use the same stored phase for transmitting. For example, during reception by an additional phase-locked loop, the crystal oscillator of the transceiver of the node functioning as the active reflector is adjusted so that the frequency and phase of the LO signal (LO—Local Oscillator) of the local oscillator match the receive signal. During switching to transmission, the additional phase-locked loop must be opened and the crystal oscillator now synchronized in frequency continues to run freely. As a result, the transceiver of the node functioning as the active reflector transmits with the same or proportional phase position and with the same frequency, as it had previously received a carrier signal. In this respect, very high requirements are placed on a free-running oscillator with regard to frequency stability and phase stability. Disturbances must be avoided, such as, for example, crosstalk of signals in the integrated circuit, which can cause phase changes.
[0008] U.S. Pat. No. 5,220,332 discloses a distance measuring system which has an interrogator and a transponder and enables nonsimultaneous measurement between two objects. A carrier signal is modulated with a (low-frequency) modulation signal with a variable modulation frequency to determine by a phase measurement or alternatively by a transit time measurement a distance from the change in the modulation signal.
[0009] U.S. Pat. No. 6,731,908 82 discloses a method for determining the distance between two objects for Bluetooth technology. In this case, the frequency is changed by frequency hops to measure a phase offset for multiple different frequencies. An object has a voltage-controlled crystal oscillator in a phase-locked loop (PLL), whereby the phase-locked loop is closed during the receiving and opened during the transmission, so that the receive signal and transmit signal have the same frequency. The phase of the local oscillator signal of the voltage-controlled crystal oscillator due to the synchronization by the PLL is thereby coherent to the received signal.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the invention to improve a method for distance measurement in a radio network as much as possible. Accordingly, a method for distance measurement between a first node and a second node of a radio network is provided. The radio network is formed, for example, according to the industry standard IEEE 802.15.1 or preferably according to the industry standard IEEE 802.15.4.
[0011] In an embodiment of the method, a first signal with a first frequency is transmitted by the first node and received by the second node by downmixing to a first intermediate frequency. The first signal is preferably generated by a local oscillator of the first node with the first frequency as a transmission frequency. Advantageously, the first signal is a first unmodulated carrier signal. An unmodulated carrier signal is, for example, a high-frequency sinusoidal oscillation. Preferably, the first frequency is varied between multiple first frequency values for the distance measurement.
[0012] A first value of a first phase can be determined by the second node for a first frequency value of the first frequency from the received first signal. Preferably, the second node determines the first value of the first phase in regard to a reference signal of the second node. Preferably, the value of the determined first phase is stored in the second node.
[0013] A second signal with a second frequency can be transmitted by the second node and received by the first node by downmixing by means of a local oscillator signal to a second intermediate frequency. The second signal is preferably generated by a local oscillator of the second node with the second frequency as the transmission frequency. Preferably, the second signal is a second unmodulated carrier signal.
[0014] A first value of a second phase can be measured by the first node from the received second signal for a first frequency value of the second frequency. Preferably, the first node determines the value of the second phase in regard to a reference signal of the first node. The measurements in this regard are made preferably in the intermediate frequency domain.
[0015] The first frequency and the second frequency are changed. For the change, a second frequency value of the first frequency and the first frequency value of the first frequency have a frequency difference. In addition, a second frequency value of the second frequency and the first frequency value of the second frequency also have a frequency difference. The frequency difference in this regard is sufficiently large to measure phase differences, based on this frequency difference. Preferably, the frequency difference is defined by a frequency interval of channels in the radio network.
[0016] A second value of the first phase is measured by the second node for the second frequency value of the first frequency. A second value of the second phase is measured by the first node for the second frequency value of the second frequency.
[0017] An amount of the first and second intermediate frequency can be the same. Both intermediate frequencies can have different signs, however.
[0018] The first frequency of the first signal and the second frequency of the second signal are spaced apart by an amount of the first and second intermediate frequency. The first node therefore transmits at the first frequency and receives at the second frequency for the distance measurement. The second node therefore transmits at the second frequency and receives at the first frequency for the distance measurement.
[0019] A distance between the first node and the second node is calculated from the first value and the second value of the first phase and from the first value and second value of the second phase and from the frequency difference.
[0020] Multiple values of the first phase and multiple values of the second phase are determined for the calculation for a plurality of frequency values. Advantageously, the determined values of the first phase and/or the second phase are transmitted to the first node as measured data via a communication service of the radio network for calculating the distance.
[0021] The invention has its object, further, to provide a circuit for a radio network node. Accordingly, a circuit of a radio network node is provided. The radio network is formed, for example, according to the industry standard IEEE 802.15.1 or preferably according to the industry standard IEEE 802.15.4.
[0022] The circuit can have a transceiver for receiving a first signal with a first frequency by downmixing to an intermediate frequency.
[0023] The circuit can have a phase measurement unit, which is set up to measure a first value of a first phase for a first frequency value of the first frequency.
[0024] The transceiver of the circuit can be set up to transmit a second signal with a first frequency value of a second frequency for determining a first value of a second phase. The determination in this case can occur by means of a circuit, set up for this purpose, of another node.
[0025] The control circuit can be set up to change the first frequency and the second frequency. In this regard, a second frequency value of the first frequency (after the change) and the first frequency value of the first frequency (before the change) have a frequency difference. A second frequency value of the second frequency (after the frequency change) has a frequency difference relative to the first frequency value of the second frequency (before the frequency change). The first frequency of the first signal and the second frequency of the second signal are spaced apart by an amount of the intermediate frequency.
[0026] The phase measurement unit can be set up to measure a second value of the first phase for the second frequency value of the first frequency after the frequency change.
[0027] The transceiver of the circuit can be set up to transmit the second signal with a second frequency value of the second frequency for determining a second value of the second phase. The determination of the second value can again occur by means of a circuit, set up for this purpose, of the other node.
[0028] The circuit can be set up to transmit the values of the first phase by means of the transceiver and/or to receive the values of the second phase. When the values of the second phase are received, the distance can be calculated by the circuit.
[0029] Another aspect of the invention can be a circuit of a radio network node, which has, for example, the aforementioned functions. The circuit has a control circuit, for example, in the form of an arithmetic unit, such as a microcontroller, which is set up to control a mode for distance measurement.
[0030] The circuit has a local oscillator for setting a transmission frequency for distance measurement. The local oscillator preferably has a phase-locked loop, an oscillator, and a frequency divider with a variable division factor.
[0031] The circuit has a sideband filter for filtering a receive signal of the distance measurement. Preferably, the circuit has in addition a mixer for downmixing a receive signal. The mixer is preferably connected to the local oscillator. The sideband filter is preferably formed as complex and/or differential. The sideband filter in one embodiment can also be called a single-sideband filter (SSBF).
[0032] The circuit can have a switching means, for example, a switch, which to control a switch position is connected to the control circuit. The switching means can have a number of switching transistors, whose control terminals are connected to the control circuit.
[0033] The sideband filter and the switching means can be connected for switching the filtering between the top sideband and the bottom sideband. This enables the circuit to operate with a different intermediate frequency position for the distance measurement. The switching of the filtering between the top sideband and the bottom sideband can be achieved, for example, by changing the phase relation of the mixer and of the sideband filter.
[0034] The control circuit can be set up to control the switching of the filtering as a function of the mode for distance measurement. For example, the control circuit initiates the mode for distance measurement and controls the switching means in a predefined switch position for distance measurement. Alternatively, the node receives a command to start the mode for distance measurement and controls the switching means in a predefined switch position as a function of the received command.
[0035] Another aspect of the invention is a system with a first node, preferably with an above-described circuit, and with a second node, preferably with an above-described circuit. The system comprising both nodes of the radio network is set up to carry out the above-described method.
[0036] The refinements described hereinafter refer to the method, as well as to the circuit and the system. Functional features of the circuit in this case emerge from the correspondingly set up process steps. Process steps can be derived from the functions of the circuit.
[0037] In an embodiment, the circuit is set up to calculate a distance to another node from the first value and second value of the first phase and from the first value and second value of the second phase and from the frequency difference, for example, by means of an arithmetic unit, such as a microcontroller.
[0038] According to an embodiment variant, the second signal is received by the first node. The received second signal in the bottom sideband passes through a first sideband filter of the first node below the first frequency of a first local oscillator. Preferably, the first signal is received by the second node. The received first signal in the top sideband passes through a second sideband filter of the second node above the second frequency of a second local oscillator. Accordingly, the other sidebands in each case are filtered out by the preferably complex sideband filters.
[0039] According to an embodiment, the first signal and the second signal are transmitted in a time interval with a time delay. To this end, the nodes are formed, for example, as a half-duplex system.
[0040] It is provided in another embodiment that the distance is calculated from a majority of determined values of the first phase and determined values of the second phase. The calculation occurs preferably by averaging or inverse fast Fourier transformation with an evaluation of amplitudes. Preferably, the frequency values of the first frequency and the second frequency are changed for a majority of determinations of the values of the first phase and the second phase. The frequency values of the transmission frequencies of the first node and of the second node in this case are changed preferably in the same direction, especially preferably with the same frequency offset. Preferably, in this case the distance of the frequency values of the transmission frequencies of the first node and of the second node does not change. The distance of the frequency values of the node transmission frequencies is preferably constant.
[0041] It is provided according to an embodiment that the first signal and the second signal for each change in the frequency values of the first frequency and the second frequency is transmitted in the same time interval delayed in time.
[0042] In a first embodiment variant, it is advantageously provided that the majority of determinations of the values of the first phase and the second phase for the changed frequency values of the first frequency and the second frequency in both nodes occurs equidistant in time to one another.
[0043] An embodiment provides that a time synchronization of the measurements of the values is performed. The time synchronization in this regard is performed in such a way that measurement times of the measurement of the values, therefore of the first, second, third, and fourth value, have a predefined temporal relationship to one another.
[0044] A first time interval and a second time interval can be the same. Preferably, the first time interval between a first measurement time of the first value of the first phase and a second measurement time of the second value of the first phase is defined. The second time interval is preferably defined between a third measurement time of the third value of the second phase and a fourth measurement time of the fourth value of the second phase. This temporal relationship has the effect that a third time interval as well between the first measurement time and the third measurement time is the same as a fourth time interval between the second measurement time and the fourth measurement time.
[0045] The time intervals embodiment predefined. The time intervals are therefore not determined first from the ongoing measurement. Preferably, the time intervals are fixedly predefined, for example, implemented as a set of parameters. Alternatively, the time intervals for a distance measurement as well can be agreed upon between the nodes. To this end, the nodes are set up accordingly. Advantageously, a respective circuit of nodes is set up to measure the values of phases at the time intervals by storing the phase value current at the measurement time, the values of the phases being determined continuously. Alternatively, the nodes are set up to measure the values of phase only at the measurement time and to store the measured value.
[0046] In an embodiment, a phase difference of the first value and the second value of the first phase and of the third value and fourth value of the second phase is calculated to determine the distance. The calculation is preferably performed using the formula:
[0000] Δφ=(φ A2 −φ B2 )−(φ A1 −φ B1 )
[0047] Here, the formula also comprises all algebraic conversions of its terms. In the formula, φA1 is the first value and φA2 is the second value of the first phase. φB1 is the third value and φB2 is the fourth value of the second phase.
[0048] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
[0050] FIG. 1A shows a schematic block diagram of two nodes of a radio network;
[0051] FIG. 1B shows a first schematic diagram;
[0052] FIG. 2 shows a second schematic diagram;
[0053] FIGS. 3A and 3B show schematically a course of a measurement process;
[0054] FIGS. 4A and 4B show schematic block diagrams of a part of a receiver;
[0055] FIG. 5 shows a fourth schematic diagram with phase measurements of two nodes of a radio network, and
[0056] FIG. 6 shows a fifth schematic diagram with phase measurements of two nodes of a radio network.
DETAILED DESCRIPTION
[0057] Distance measurements in a radio network with multiple nodes can be based on phase measurements. In this case, a preferably unmodulated carrier signal with the frequency fa and an unmodulated carrier signal with the frequency fb are transmitted one after another. The frequencies differ only in a small difference frequency Δf. In the receiver, the phase of the received wave is evaluated and stored as measured values φ1 and φ2. The distance d between the stations can be calculated from this:
[0000]
d
=
(
ϕ2
-
ϕ1
)
c
2
πΔ
f
(
1
)
[0058] Here, c is the speed of light.
[0059] Two circuits of a first node A and a second node B are shown in FIG. 1A , whereby none of the nodes A, B function as a mere active reflector. The circuit of the first node A has a transmitter/receiver circuit 130 (TRX), which is connected or connectable to an antenna 10 and is provided with a first local oscillator signal LO 1 by a crystal oscillator 110 as a reference clock generator (XOSC 1 ) and a phase-locked loop 120 (PLL). The arrangement comprising transmitter/receiver circuit 130 , phase-locked loop 120 , and reference clock generator 110 can also be called a radio 100 .
[0060] The circuit of the first node A furthermore has a frequency divider 150 , which in the exemplary embodiment of FIG. 1 divides the first reference frequency f(XOSC 1 ) of the first reference signal XOSC 1 of reference clock generator 110 by the division factor OF, for example, eight, to provide a first comparison signal SV 1 with a frequency f(SV 1 ), which is equal to an intermediate frequency ZF 2 and is, for example, about 2 MHz. Inputs of a phase measurement unit 140 (PMU) of the circuit of the first node A are connected to frequency divider 150 and transmitter/receiver circuit 130 . Transmitter/receiver circuit 130 is formed for downmixing a carrier signal RF 2 , received by second node B, to an intermediate frequency signal ZF 2 . The intermediate frequency signal ZF 2 in the exemplary embodiment of FIG. 1 has the intermediate frequency f(ZF 2 ) of about 2 MHz.
[0061] The phase φ of the received signal RF 2 is measured by phase measurement unit 140 , which can also be called a phase detector. The measurement occurs in the intermediate frequency domain, because during the frequency conversion in a mixer of transmitter/receiver circuit 130 , the phase position of the carrier signal RF 2 transmitted by second node B is maintained. Phase measurement unit 140 is therefore formed to measure the phase difference between the intermediate frequency signal ZF 2 and the divided-down reference frequency as comparison signal SV 1 . The measured values of the phase φ are preferably stored.
[0062] In the exemplary embodiment of FIG. 1A , the circuit of the second node B is made the same as that of the first node A. The circuit of the second node B also has a transmitter/receiver circuit 230 , which can be or is connected to an antenna 20 . Transmitter/receiver circuit 230 is provided with a second local oscillator signal LO 2 by a crystal oscillator 210 as reference clock generator (XOSC 2 ) and a phase-locked loop 220 . The arrangement comprising transmitter/receiver circuit 230 , phase-locked loop 220 , and reference clock generator 210 can also be called a radio 200 .
[0063] The circuit of the second node B also has a frequency divider 250 to provide a second reference signal SV 2 at an input of a phase measurement unit 240 . Frequency divider 250 for dividing down the reference frequency f(XOSC 2 ) of second reference signal XOSC 2 of reference clock generator 210 by the factor OF, for example, eight, is connected to reference clock generator 210 of the circuit of the second node. The phase of the received signal RF 1 is measured using phase measurement unit 240 . For this purpose, an input of phase measurement unit 240 is connected to an output of transmitter/receiver circuit 230 . Phase measurement unit 240 is therefore formed to measure the phase difference between an intermediate frequency signal ZF 1 and the comparison signal SV 2 . The measured values of the φ are preferably stored.
[0064] Reference clock generators 110 and 210 are formed as crystal oscillators and decoupled from one another. Because of fabrication variations or different temperatures, the first frequency f(XQSC 1 ) of reference clock generator 110 of the first node A and the frequency f(XQSC 2 ) of reference clock generator 210 of the second node B can deviate from one another. When the frequency f(XQSC 1 ) of reference clock generator 110 of the first node A and the frequency f(XQSC 2 ) of reference clock generator 210 of the second node B are unsynchronized, a time synchronization of the measurements of the phase in the first node A and the phase in the second node B is necessary to take into account the phase error caused by the frequency offset between the first reference clock generator and the second reference clock generator.
[0065] A schematic diagram with frequencies is shown in FIG. 1B . Both nodes A, B shown in FIG. 1A use the same (low) intermediate frequency fZF of, for example, 2 MHz. In this case, only the amount of the intermediate frequency is shown in FIGS. 1A and 1B . The intermediate frequencies fZF differ by the sign (not shown). Both transmitter/receiver circuits (transceivers) of nodes A, B operate at different intermediate frequency positions. One of the transmitter/receiver circuits is switched to the opposite intermediate frequency position of the other node A/B by filtering of the corresponding sideband.
[0066] For example, the first node A transmits at the oscillator frequency f LOA1 =2404 MHz and receives at the reception frequency f EA1 =2402 MHz. The second node B then transmits at the oscillator frequency f LOB1 =2402 MHz and receives at the reception frequency f EB1 =2404 MHz. For the distance measurement, the oscillator frequencies f LOA1 and f LOB1 are changed by the same frequency step Δf, which may be positive or negative. If the frequency step Δf=+10 MHz, then the first node A transmits at the oscillator frequency f LOA2 =2414 MHz and receives at the reception frequency f EA2 =2412 MHz, whereby the second node B then transmits at the oscillator frequency f LOB2 =2412 MHz and receives at the reception frequency f EB2 =2414 MHz. Transmission frequency f LOA1 , f LOA2 , f LOB1 , f LOB2 and reception frequency f EA1 f EA2 , f EB1 , f EB2 differ in each case by the same intermediate frequency fZF.
[0067] Therefore, the reception frequency of the first node A is above a frequency of the phase-locked loop 120 (PLL) to generate the local oscillator signal LO 1 in the first node A and the reception frequency of the second node B is below a frequency of the phase-locked loop 220 (PLL) to generate the local oscillator signal LO 2 in the second node B. It is especially advantageous in this regard that the frequency of phase-locked loops 120 , 220 for two measurements in both directions need not be switched between the nodes A, B, so that no settling process of the phase-locked loop 120 , 220 needs to occur. A better phase stability and therefore a higher measuring accuracy are achieved. Only after a frequency step Δf, do both phase-locked loops 120 , 220 need to settle quickly.
[0068] Transmitter/receiver circuit 130 of the first node A has a differential complex mixer 310 , 310 ′ and a differential complex filter 320 , 320 ′. Transmitter/receiver circuit 230 of the first node B also has a differential complex mixer 310 , 310 ′ and a differential complex filter 320 , 320 ′, as is shown schematically by way of example in FIGS. 4A and 4B .
[0069] For example, the signal RF, received in the first node A, is downmixed by means of a complex mixer 310 , 310 ′ to an intermediate frequency signal ZF and filtered by means of a first complex sideband filter 320 , 320 ′ of the first node A below the first oscillator frequency f LOA1 , f LOA2 of the oscillator signal LO. The signal RF, received in the second node B, is downmixed by means of a complex mixer 310 , 310 ′ to an intermediate frequency signal ZF and filtered by means of a second complex sideband filter 320 , 320 ′ of the second node B above the second oscillator frequency f LOB1 , f LOB2 . The two exemplal)′ embodiments of FIGS. 4A and 4B can be used alternatively in this case.
[0070] In the exemplary embodiment of FIGS. 4A and 4B , the inphase component I, the real part, and the quadrature phase component Q, the imaginary part, are applied as differential signals at mixer 310 , 310 ′ and sideband filter 320 , 320 ′. The filtering of the top or bottom sideband is set by switching by switching means 330 , 330 ′. Switching means 330 , 330 ′ are formed in the exemplary embodiments of FIGS. 4A and 4B as an intermediate switch, which for setting of the sideband to be filtered cause a 180° phase rotation of the quadrature phase Q in the exemplary embodiment of FIG. 4A and a 180° phase rotation of the inphase I in the exemplary embodiment of FIG. 4B . Switching means 330 , 330 ′ are controlled by a control circuit 160 or 260 , which may be, for example, a microcontroller of a node A, B.
[0071] In addition, for controlling switching means 330 or 330 ′, control circuit 160 of the first node A is set up to trigger the measurement of the phase φ at at least two predefined times t 2 , t 4 . To control the phase measurement at the at least two predefined times t 2 , t 4 , control circuit 160 is connected, for example, to a control input en of phase measurement unit 140 . For example, at the at least two predefined times t 2 and t 4 , a value of the phase cp is calculated or at the at least two predefined times t 2 and t 4 , the current value of the continuously calculated phase cp is stored.
[0072] Control circuit 260 of the second node B is also set up to trigger the measurement of the phase φ at at least two predefined times t 1 , t 3 . To control the phase measurement at the at least two predefined times t 1 , t 3 , control circuit 260 is connected, for example, to a control input en of phase measurement unit 240 .
[0073] A time interval between the at least two predefined times t 2 , t 4 of control circuit 160 in the first node A and a time interval between the at least two predefined times t 1 , t 3 of control circuit 260 in the second node B are the same in this case. Therefore, a time interval between phase measurements of the first frequencies and a time interval between phase measurements of the second frequencies is also the same after a frequency step M. If additional phases at additional (carrier) frequencies are to be measured, then, these as well are controlled by control circuit 160 , 260 in a same time interval.
[0074] Furthermore, control circuit 160 of the first node A is set up to control a first multiplication factor in phase-locked loop 120 . Control circuit 260 of the second node B is set up to control a second multiplication factor in phase-locked loop 220 of the second node B. The frequencies, differing by the intermediate frequency, of oscillator signals LO 1 , LO 2 of the first node A and of the second node B are controlled by the multiplication factors. For example, the frequencies of oscillator signals L 01 , LO 2 are changed in steps.
[0075] A diagram for a measurement process for phase measurement is shown schematically in FIG. 5 . In the method for distance measurement between the first node A and the second node B, a first unmodulated carrier signal with a carrier frequency f 3 is transmitted by the first node A and received by the second node B. A second unmodulated carrier signal with a carrier frequency f 1 is transmitted by the second node B and received by the first node A. Carrier frequency f 1 differs from carrier frequency f 3 by the amount of an intermediate frequency fZF. In the exemplary embodiment of FIG. 5 , the intermediate frequency fZF is the same in both nodes.
[0076] A first value φA1 of a first phase is measured at a first measurement time t 2 by the first node A. A third value φB1 of a second phase is measured at a third measurement time t 1 by the second node B.
[0077] This is followed by an increase in the carrier frequency f 3 by a frequency difference Δf to the increased carrier frequency f 4 . At the same time, an increase in the carrier frequency f 1 by the same frequency difference Δf to the increased carrier frequency f 2 occurs. The first unmodulated carrier signal is transmitted with the increased carrier frequency f 4 by the first node A and received by the second node B. The second unmodulated carrier signal is transmitted with the increased carrier frequency f 2 by the second node Band received by the first node A. The increased carrier frequency f 4 as well differs from the increased carrier frequency 12 by the amount of an intermediate frequency fZF. In the exemplary embodiment of FIG. 5 , the intermediate frequency fZF is again the same in both nodes.
[0078] After the increase in the carrier frequencies f 2 , f 4 , a second value φA2 of the first phase is measured at a second measurement time t 4 by the first node A. A fourth value φB2 of a second phase is measured at a fourth measurement time t 3 by the second node B. In an intermediate phase in each case, which is shown as shaded in FIGS. 5 and 6 , the first node A and the second node B switch between transmitting TX and receiving RX. The technical effect is achieved in this regard that the frequency of phase-locked loops 120 , 220 for two measurements in both directions is not switched between the nodes A, B, so that no settling process of the phase-locked loop 120 , 220 occurs.
[0079] In the rather theoretical case of FIG. 5 , there is no frequency offset between the frequencies f(XOSC 1 , XOSC 2 ) of first reference clock generator 110 for clocking phase-locked loop 120 of the first node A and of second reference clock generator 210 for clocking phase-locked loop 220 of the second node B. FIG. 5 is intended first to represent only the rather theoretical case that the frequencies f(XOSC 1 , XOSC 2 ) of the reference clock generators are exactly the same. The measured phase cp is therefore constant during the time 1 .
[0080] In the exemplary embodiment of FIG. 5 , phase-locked loops 120 , 220 require, for example, 50 μs or less to settle. Both phase measurements M 2 are then repeated at times t 3 and t 4 for the frequencies f 4 and f 2 , whereby the second phase value φA2 of the first phase are determined in the first node A and the fourth phase value φB2 of the second phase in the second node B. Thus, the first value φA1 of the first phase is assigned to carrier frequency f 1 and the third value φB1 of the second phase is assigned to carrier frequency f 3 . The second value φA2 of the first phase is assigned to the increased carrier frequency f 4 . The fourth value φB2 of the second phase is assigned to the increased carrier frequency f 2 .
[0081] A phase difference h.<p can be calculated from the phase values φA1, φB1, and φB2 as follows:
[0000] Δφ=(φ A2 −φ B2 )−(φ A1 −φ B1 ) (2a)
[0000] By conversion, one obtains:
[0000] Δφ=(φ A2 −φ A1 )−(φ B2 −φ B1 ) (2b)
[0082] Thus, the distance d can be calculated as follows:
[0000]
d
=
Δϕ
c
πΔ
f
(
3
)
[0083] In a departure from the rather theoretical presentation in FIG. 5 , in reality nodes A, B will have reference clock generators 110 , 210 , whose frequencies f(XOSC 1 ), f(XOSC 2 ) have a frequency offset, for example, because of fabrication tolerances or different temperatures. As a result, the phase φ in the respective receiving node changes, as is shown schematically by the slopes of the phase profiles in FIG. 6 .
[0084] The phase change in the measurement M 1 between the measurement times t 1 and 12 causes a phase error φerr in a specific phase φcalc. The same phase error φerr arises in the measurement M 2 at measurement times t 3 and t 4 , when a time interval between the phase measurement M 1 , M 2 is sufficiently small. If the time intervals t 2 -t 1 and t 4 -t 3 or the time intervals t 3 -t 1 and t 4 -t 2 are the same, the phase error φerr is also the same and drops out during the calculation of the phase difference Δφ (see Equation (2a/2b)). As a result, the distance measurement based on the phase measurement can also be used when reference clock generators 110 , 210 of both nodes A, Bare unsynchronized, as in the exemplary embodiment of FIG. 1A .
[0085] To circumvent the problem of multipath propagation, phase measurements are advantageously made over the entire available hand. A diagram of the measurements M 1 , M 2 , M 3 , etc., is shown in FIG. 2 . N+1 measurements are performed, whereby phase differences Δφ are being measured from adjacent frequencies N. It is necessary for this purpose that the individual measured phases φA1, φB1, φA2, φB2, φA3, φB3, etc., are brought together in an arithmetic unit of a node A, B. For example, the phases φB1, φB2, φB3 are transmitted by standard communication in the radio network from the second node B to the first node A.
[0086] The following applies for calculating two phase differences:
[0000] Δφ 1 =(φ A2 −φ B2 )−(φ A1 −φ B1 ) (4)
[0000] and
[0000] Δφ 2 =(φ A3 −φ B3 )−(φ A2 −φ B2 ) (5)
[0000] or in general for any number of phase differences:
[0000] Δφ N =(φ A,N+1 −φ B,N+1 )−(φ A,N −φ B,N ) (6)
[0087] Each phase difference can be converted to a distance dN using the equation
[0000]
d
N
=
Δϕ
N
c
πΔ
f
.
(
7
)
[0088] The distance values dN will differ clearly because of multipath propagation.
[0089] In a first exemplary embodiment for evaluating the N distance measurements, the average of the distance values dN is formed. Simulations have shown that this method produces relatively accurate results, when the multipath propagation is moderate. In other words, the component with the shortest connection (line of sight) of the channel impulse response dominates.
[0090] In a second exemplary embodiment for evaluation the N distance measurements, the amplitude of the receive signal is measured in addition in node A, B and stored for each frequency. The complex spectral component is calculated from the amplitude and phase for each frequency as
[0000] I N +jQ N =A N (cos(φ N )+ j ·sin(φ N )) (8)
[0091] The channel impulse response is calculated from the N spectral values by an inverse rapid Fourier transformation (IFFT). The first impulse (the component with the shortest line of sight) can be found using a search algorithm and thereby its transit time. This method is clearly more costly than averaging, but produces reliable results with strong multipath propagation as well.
[0092] A course of a measurement process is shown schematically as a diagram in FIGS. 3A and 3B . The first node A initializes the distance measurement and in step 1 transmits a frame to the second node B with the command to perform a distance measurement. The transmission frequency fTX in this case is set to the channel frequency fch for communication in the radio network. The setting for filtering of a sideband is transmitted with the frame to the second node B. Alternatively, it is also possible to predefine fixedly which node A, B filters out the top or bottom sideband. In addition, a sequence of measuring frequencies or frequency steps is transmitted to the second node B. Alternatively, the sequence of the measuring frequencies for a phase measurement can also be fixedly predefined.
[0093] In step 2 of the process in FIG. 3A , the second node B transmits a frame Fsync to the first node A for time synchronization of the further process course for the distance measurement. The frame Fsync for time synchronization is, for example, a standard frame, which is formed according to a standard (for example, industry standard IEEE 802.15.4) and may have, for example, a preamble, a data header, and data to be transmitted. No data transmission is necessary for synchronization, so that an empty frame can be transmitted. In this respect, the time necessary for the transmission of the frame Fsync for time synchronization is known, i.e., for transmission by the second node B and receiving by the first node A. The second node starting at end time TXE of the transmitted frame Fsync starts a timer with the length tAS, which ends at the start of the distance measurement. The first node A also starts a timer with the length tBS, which also ends at the start of the distance measurement. The timer of the first node A is started by the determination of the time SFD (in industry standard IEEE 802.15.4, this corresponds to an indicator of an end of the preamble in the frame) in the received frame Fsync for the time synchronization.
[0094] Proceeding from the end of the timer of the second node B, measurement times t 1 , t 3 , t 5 , etc., for measuring the phase are established. Proceeding from the end of the timer of the first node, measurement times t 2 , t 4 , t 6 , etc., for measuring the phase are established. To determine the distance, it is necessary in this case that the time interval between measurement times t 1 , t 3 , t 5 , etc., in the second node B and the time interval between the measurement times t 2 , t 4 , t 6 , etc., in the first node are the same and constant. The time interval is predefined. The predefined time interval can be fixedly implemented. Alternatively, the time interval for predefining is agreed upon between nodes A, B. Beyond the measurement times shown in FIG. 3A , additional measurement times, which are not shown in the simplified illustration in FIG. 3A , in the same time interval are necessary for the N measurements.
[0095] In step 3 , the transmission frequency FIX is switched from the preceding communication frequency fch to the lowest frequency. In this case, the local frequencies of the local oscillators differ by approximately the intermediate frequency of the intermediate frequency signal ZF. During the times tAS and tBS until the end of the timer, the phase-locked loops 160 , 260 of the nodes A, B settle. The setting of the lowest frequency in the ISM band, for example, to the value 2404 MHz is shown schematically for node A in FIG. 3B . First, the node A transmits in the transmission mode TX. In the meantime, the second node B receives in the receive mode RX and measures the phase at time t 1 and stores the phase value. Next, the second node B transmits without a change in the frequency of its local oscillation and a phase value is measured and stored in the first node A at measurement time t 2 .
[0096] The transmission frequency fTX is then increased in each node by a frequency step Δf and the phase-locked loops settle again, whereby the frequency offset between the local oscillators of nodes A and B is again equal to the intermediate frequency of the intermediate frequency signal ZF. Then, at times t 3 and t 4 new phase values are measured and stored. This process repeats up to the highest frequency in the band of 2480 MHz. The increase is shown schematically in FIG. 3B . In step 3 , therefore, N measurements are taken with different transmission frequencies fTX.
[0097] In step 4 , both nodes A, B switch back to the network frequency fch. The second node B transmits the measured and stored phase values back to the first node A by means of a standard communication in the radio network. In step 5 , the node A calculates the distance d between the nodes A, B from this phase information and its own phase measurements.
[0098] The invention is not limited to the shown embodiment variants in FIGS. 1A through 6 . For example, it is possible to provide a different sequence of frequencies for phase measurement, for example, from the highest to the lowest transmission frequency fTX.
[0099] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims. | In certain embodiments, a method includes transmitting, by a first node, a first signal with a first frequency. The method includes receiving a second signal with a second frequency by downmixing the second signal to an intermediate frequency. The method includes determining a first value of a first phase for the second frequency. The method includes transmitting a third signal with a third frequency, the first frequency and the third frequency having a frequency difference, and receiving a fourth signal with a fourth frequency, the second frequency and the fourth frequency having the frequency difference. The method includes determining a second value of the first phase for the fourth frequency. The first frequency and the second frequency are spaced apart by an amount of the intermediate frequency, and the third frequency and the fourth frequency are spaced apart by the amount of the intermediate frequency. | 6 |
This is a continuation of application Ser. No. 07/935,516 now abandoned, filed on Sept. 8, 1992, now abandoned, which is a continuation of Ser. No. 07/438,863, filed on Nov. 20, 1989, now U.S. Pat. No. 5,157,603 which is a division of Ser. No. 267,713 filed on Nov. 11, 1988, now U.S. Pat. No. 4,933,843, which is a continuation of Ser. No. 928,170, filed Nov. 6, 1986, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to microsurgical and ophthalmic systems and more particularly to a programmable control system and console for operating microsurgical instruments.
Present day ophthalmic microsurgical systems provide one or more pneumatically operated (fluid pressure operated) surgical instruments connected to a control console. The control console provides the fluid pressure signals for operating the instruments and usually includes several different types of human actable controllers for controlling the fluid pressure signals supplied to the surgical instruments. Usually included is a foot pedal controller which the surgeon can use to control a surgical instrument.
The conventional console also has push button switches and adjustable knobs for setting the desired operation characteristics of the system. The conventional control system usually Serves several different functions. For example, the typical ophthalmic microsurgical system has both anterior and posterior segment capabilities and may include a variety of functions, such as irrigation/aspiration, vitrectomy, microscissor cutting, fiber optic illumination, and fragmentation/emulsification.
While conventional microsurgical systems and ophthalmic systems have helped to make microsurgery and ophthalmic surgery possible, these systems are not without drawbacks. Microsurgical and ophthalmic systems are relatively costly and are often purchased by hospitals and clinics for sharing among many surgeons with different specialities. In eye surgery, for example, some surgeons may specialize in anterior segment procedures, while other surgeons may specialize in posterior segment procedures. Due to differences in these procedures, the control system will not be set up in the same manner for both. Also, due to the delicate nature of this type of surgery, the response characteristics or "feel" of the system can be a concern to surgeons who practice in several different hospitals, using different makes and models of equipment. It would be desirable to eliminate the differences in performance characteristics between one system and the next, while at the same time providing enough flexibility in the system to accommodate a variety of different procedures. The prior art has not met these objectives.
The present invention greatly improves upon the prior art by providing a programmable and universal microsurgical control system, which can be readily programmed to perform a variety of different surgical procedures and which may be programmed to provide the response characteristics which any given surgeon may require. The control system is preprogrammed to operate in a variety of different modes to provide a variety of different procedures. These preprogrammed modes can be selected by pressing front panel buttons.
In addition to the preprogrammed modes, each surgeon can be provided with a programming key, which includes a digital memory circuit loaded with particular response characteristic parameters and particular surgical procedure parameters selected by that surgeon. By inserting the key into the system console jack, the system is automatically set up to respond in a familiar way to each surgeon.
For maximum versatility, the console push buttons and potentiometer knobs are programmable. Their functions and response characteristics can be changed to suit the surgeons' needs. An electronic display screen on the console displays the current function of each programmable button and knob as well as other pertinent information. The display screen is self-illuminating so that it can be read easily in a darkened operating rooms.
More specifically, the microsurgical control system of the invention is adapted for controlling fluid pressure controlled microsurgical instruments. The term "fluid pressure", unless otherwise specified, includes both positive pressure and negative pressure (vacuum), as well as pneumatic imputations. The microsurgical control system comprises a means for providing fluid pressure couplable to the microsurgical instrument for delivering a fluid pressure signal to the instrument. A manually actuable controller is coupled with the means for providing fluid pressure for adjusting the fluid pressure signal in response to human actuation. A digitally programmed electronic circuit coupled to the controller selectively alters the manner in which the controller responds to human actuation.
Further, in accordance with the invention, the microsurgical control system includes a console and means on the console for connecting to at least one microsurgical instrument. The console has an electronic display screen and a plurality of manually actuable controllers disposed thereon at locations corresponding to predetermined regions of the display screen. The system includes a menu generating means coupled to the display screen for writing predetermined human readable messages at the predetermined regions of the display screen. A procedure control means is coupled to the connecting means for defining and providing a plurality of predetermined and selectable surgical procedures for controlling the inset. A procedure selection means is coupled to the procedure control means and is responsive to the human actuable controller, for causing the procedure control means to perform a selected one of the plurality of procedures.
Still further in accordance with the invention, the control means includes a means for defining predetermined and selectable surgical procedures. The defining means includes a jack on the console and at least one memory circuit removably connected to the jack, for storing parameters used to define the surgical procedures.
For a more complete understanding of the invention, its objects and advantages, reference may be had to the following specification and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the microsurgical system of the invention;
FIG. 2 is a front view of the system console showing the front panel layout in greater detail;
FIG. 3 is a system block diagram of the electronic control system of the invention;
FIG. 4 is a detailed schematic diagram illustrating the processor and related components of the electronic control system;
FIG. 5 is a detailed schematic diagram illustrating the reset and watchdog circuits of the electronic control system;
FIG. 6 is a detailed schematic diagram illustrating the system bus structure of the electronic control system;
FIG. 7 is a detailed schematic diagram illustrating the dual UART circuit of the electronic control system;
FIG. 8 is a detailed schematic diagram illustrating the memory circuits of the electronic control system;
FIG. 9 is a detailed schematic diagram illustrating the key memory circuits of the electronic control system;
FIG. 10 is a detailed schematic diagram illustrating the digital potentiometer circuits of the electronic control system;
FIG. 11 is a detailed schematic diagram illustrating the foot controller pedal circuitry of the electronic control system;
FIG. 12 is a detailed schematic diagram illustrating the interrupt request handling circuitry of the electronic control system;
FIG. 13 is a detailed schematic diagram illustrating the video circuitry of the electronic control system;
FIG. 14 is a detailed schematic diagram also illustrating the video circuitry of the electronic control system;
FIGS. 15-17 are detailed schematic diagrams illustrating the analog peripheral control circuitry of the electronic control system; and
FIGS. 18 through 31 depict various menus displayable on the display screen of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1 and 2, a microsurgical control system 10 is provided having a foot pedal assembly 24 according to the present invention. The control system 10 includes a system console 12 which has an upwardly and inwardly sloping front panel 14 and at least one removable access door 254 in one of the side panels. On the front panel 14 is an electronic display screen 16, a plurality of push button switches or touch sensitive pads 18 and a plurality of "endless" digital potentiometer knobs 20. The push buttons 18 and knobs 20 are actuable by the surgeon or nurse to select various different modes of operations and functions used in various surgical procedures.
The console 12 also includes a cassette eject button 36, an irrigation pinch valve 37, and a power on/off switch 38.
The electronic display screen 16 is controlled by a computer to provide one or more different menus or messages which instruct the operator as to the function of the buttons 18 and knobs 20 for the particular mode selected. The display screen 16 may be conceptually divided into display screen regions 22 with the buttons 18 and knobs 20 being positioned at locations around the periphery of the screen 16 corresponding to the regions 22. By virtue of the location of the buttons 18 and knobs 20 adjacent the screen 16, for example, a message in the upper left-hand comer of the screen 16 is readily understood by the operator as referring to the upper left most button. This arrangement allows the indicated function of each button 18 and knob 20 to be readily changed. The use of an electronic display screen 16 also permits the buttons 18 and knobs 20 to be labeled in virtually any language.
The microsurgical control system 10 is adapted for use with a number of different surgical instruments. As shown in FIG. 1, a fiber optic illumination instrument 214 is coupled to the console 12 via fiber optic cable 212. Also illustrated is a fragmentation emulsification instrument 28 coupled to the console 12 through an electrical cable 30. The instrument 28 is also coupled to a collection container or cassette 100 through an aspiration tube 31. A cutting instrument 32 is also shown which is coupled to the console 12 through tubing 34 and to the cassette 100 through tubing 35. The cutting instrument 32 may be a guillotine cutter for vitrectomy procedures, or it may be a microscissors inset for proportionate and multiple cutting. However, when the microscissors instrument is used, the instrument is not connected to the cassette 100.
While certain microsurgical instruments have been illustrated in FIG. 1, it will be understood that the microsurgical control system 10 can be used with other similarly equipped instruments. In general, any of the microsurgical instruments are actuated or controlled by fluid pressure (positive pressure or negative pressure). However, it should be appreciated that other suitable types of control signals may be used in the appropriate application.
To provide irrigation/aspiration capabilities, the control system 10 further includes the removable cassette 100 which may be inserted into a cassette slot 102 in the console 12. The cassette 100 has a passageway opening 148 to which an aspiration tube from an aspiration instrument may be connected. The console 12 also includes a plurality of couplers 40 to which surgical instruments described above may be attached. Above each coupler 40 is a light emitting diode 42 which is illuminated when the instrument connected to the associated coupler 40 is activated. To store the operating parameters of a particular microsurgical operation, the control system 10 electrically communicates with a digitally encoded memory key K21. The memory key K21 includes an integrated memory circuit which stores the operating parameters for a particular surgical procedure. The console 12 receives the key K21 through a slot J21. Suitable types of memory keys K21 are commercially manufactured by Data Key Inc., Burnsville, Minn. However, it should be appreciated that other suitable means for accessing specifically assigned memory locations may be used in the appropriate application.
A further description of the control system may also be found in the following commonly owned patent applications which were filed on even date herewith, and which are hereby incorporated by reference: Scheller, et al U.S. patent application Ser. No. 06/928,265, entitled "Collection Container For Ophthalmic Surgical Instruments" now U.S. Pat. No. 4,775,897; Scheller, et al U.S. patent application Ser. No. 06/927,827, entitled "Illumination System For Fiber Optic Lighting Instruments now U.S. Pat. No. 4,757,426; and Scheller U.S. patent application Ser. No. 06/927,807, entitled "Foot Pedal Assembly For Ophthalmic Surgical Instrument" now U.S. Pat. No. 4,837,857.
Referring now to FIG. 3, a system overview of the microsurgical control system will be presented. The control system of the presently preferred embodiment centers around a microprocessor 310, such as a Motorola 6809. Connected to the reset terminal of the microprocessor is a reset logic circuit 312 and watchdog circuit 314. Reset logic circuit 313 performs the power on reset and manual reset functions, while the watchdog circuit monitors the operation of the microprocessor and causes it to be reset in the event it should enter an endless software loop or wait state. The details of the reset logic and watchdog circuits will be discussed below in connection with FIG. 5.
Microprocessor 310 communicates with a processor address bus PAn and with a processor data bus PDn. In the presently preferred embodiment, the address and data bus structure is divided into two parts, one part for addressing the kernel of the machine and the other part for addressing the higher level system components. The kernel provides most of the peripheral device-independent functions and gives the control system its default or start up characteristics. The higher level system portion gives the control system the capability of being programmed to handle a variety of different surgical procedures with response characteristics tailor fit to a particular surgeon. As seen in FIG. 3, the processor address bus PAn and the processor data bus PDn both branch forming two portions. The resulting four branches are buffered in buffers 316, 318, 320 and 322. Buffers 316 and 318 address the kernel of the machine on address bus An and data bus Dn. Buffers 320 and 322 address the system portion of the machine on address bus BAnSYS and on data bus BDnSYS.
In order to select whether the kernel portion or the system portion is to be addressed by microprocessor 310 and in order to maintain control over the direction of data flow, a buffer control circuit 324 is provided. Buffer control circuit 324 is responsive to address lines A11-A15 of address bus An. It provides a plurality of control signals coupled to buffers 318 and 322 for selecting which of the two data buses (Dn or BDnSYS) are active and for controlling the direction of data flow. Thus by addressing buffer control circuit 324, microprocessor 310 can selectively address either the kernel portion or the system portion of the invention.
The bulk of the kernel appears generally at 326 and includes EPROM 328 and nonvolatile RAM 330. EPROM 328 contains the kernel operating system program instructions while nonvolatile RAM 330 contains the default data values used to define the system's default operating parameters. Also coupled to the kernel is dual UART (DUART) 332 which provides serial communication with microprocessor 310 via ports A and B. These ports my be accessed in order to monitor the microprocessor machine states during software debugging and programming and may also be used to connect to an external computer system for use in loading updated software into the machine and for testing the system. If desired, either or both of the ports can be connected to modem circuits for remote communication with the system via telephone lines. This feature would permit software updates to be made without requiring the unit to be shipped back to the factory.
Also part of the kernel 326 is a peripheral decoding circuit 334 which is coupled to address bas An and which provides a plurality of board select signals BOARDn and a plurality of chip select signals CSn, which microprocessor 310 can activate to select a particular peripheral controller board or to select a particular peripheral controller chip. These will be discussed more fully below.
The system portion of the invention is illustrated generally at 336. The system portion communicates with the system bases BAnSYS and BDnSYS. Included in the system portion are a plurality of universal memory sites 338 which can contain random access memory chips programmed to contain alternate response characteristics which differ from the default characteristics stored in RAM 330. Also provided is EEROM 340 which is an electrically erasable ROM used to store the calibration arrays for determining the response of the pneumatic systems or fluid pressure controlled systems of the invention. The values stored in EEPROM 340 represent calibration values preferably set and stored at the factory. Because an electrically erasable ROM is used, these values can presently preferred embodiment, this reprogramming is not available to the end user, but would normally be performed by a qualified technician via the serial ports A and B of dual UART 332. The microfiche appendix provides one example of a suitable program which could used in the control console according to the present invention. This microfiche appendix is hereby incorporated by reference.
Each of the universal memory sites 338, as well as EEROM 340, EPROM 328 and nonvolatile RAM 330 include a memory select control input MSn. Control circuit 324, under microprocessor control, provides the memory select signals used to activate a particular memory device. In addition to these memory devices, the invention also has the capability to address a removable memory device which can be removably connected to a jack accessible on the exterior of the system console. This removable memory device or key memory 342 may be programmed by the end user for storing parameters used to define particular surgical procedures and particular response characteristics desired by a given surgeon. Although the key memory devices may be implemented in a variety of different package configurations, the presently preferred configuration is in the form of a removable electronic key. The key has a plurality of electrical contacts connected to a nonvolatile electrically alterable memory chip which is encapsulated in the body of the key. When the key is inserted into the jack on the system console and turned, the encapsulated memory chip is coupled to the key memory space 342 of the system portion of the circuit. The particular parameters and surgical procedures stored in the key memory are then accessible to microprocessor 310 to override the default parameters stored in nonvolatile RAM 330. It should be noted, however, that the key is only necessary to override the default values, and that the system may be operated without the key using the default values.
In order to provide an interface between the human operator and the control system, several human actuable controllers are provided. These controllers include a plurality of "endless" digital potentiometers 20 and associated buffering circuitry 344 to which the front panel potentiometer knobs 20 are connected. In one embodiment according to the present invention, these digital potentiometers are Hewlett Packard Model HEDS7501 controllers. The signals generated by these potentiometers are related to specific operating parameters by the software. Accordingly, it should be that this feature permits multiple uses to be made of these potentiometers for different surgical procedures. As will be seen in connection with FIGS. 18-31, the display screen 16 is used to display an indication of the special operating parameters for these potentiometers.
The digital potentiometers are connected to the system data bus BDnSYS and are selected by activation of certain of the chip select lines (CS2-CS4). The foot controller pedal 24 coupled to foot control circuitry 346 also provides human actuable control via the system data bus. In addition, push buttons 18 likewise provide human actuable control. These buttons are coupled through push button interface circuitry 348 to the system data bus. Like the digital potentiometer circuitry, the foot control circuitry and the push button interface circuitry are selected by certain of the chip select lines. The foot controller is selected by chip select lines CS13-CS15, and the push button circuits are selected by CS8-CS9.
The human actuable controllers, i.e. the digital potentiometers, the foot controller pedal and the push button monitor switches, may be considered as peripheral devices. In addition to these peripheral devices, the microsurgical control system 10 also includes several analog peripheral devices, i.e. the fluid pressure actuated surgical implements. To simplify the illustration in FIG. 3, these analog peripherals and their associated control circuitry have been designated generally by block 350.
The microsurgical control system also includes a video monitor 352 which defines display screen 16 and on which human readable messages are displayed. As will be more fully explained below, monitor 352 displays a series of different menus which identify the current function of each of the monitor switches 18 and digital potentiometers 20. In addition, the menus also provide certain other information to the surgeon, such as the operating parameter values selected by the appropriate rotation of the digital potentiometers. The video monitor is supplied with horizontal and vertical sync signals and a video signal via signal processor circuit 354. Signal processor circuit 354 receives the 10 MHz. clock signal from oscillator 356 as well as the vertical and horizontal sync signals from CRT controller 358. Each of the pixel locations on monitor 352 has one or more corresponding memory cell locations within video RAM circuit 360. The video RAM circuit is a dual ported memory circuit which can be directly accessed by both the monitor via the shift register (SR) interface circuit 362 and which may be accessed by the microprocessor via buffer 364. The presently preferred video screen has a 256 by 512 pixel resolution. Data to be displayed on monitor 352 is input through buffer 364 to video RAM 360 during a first half of the microprocessor machine cycle. During the second half of the machine cycle, the data is converted to a video signal and written to the monitor for display. As illustrated in FIG. 3, the monitor circuit defines a separate buffer data bus BDnVID, which is coupled to the system data bus BDnSYS through buffer 366.
Because many of the peripheral devices are interrupt handled devices, a system timer and interrupt request circuit 368 is provided. When a peripheral device needs attention of the microprocessor, it generates an interrupt which is handled by the interrupt request circuit 368, causing the appropriate microprocessor interrupt to be generated. Circuit 368 also generates a system timer which is coupled to a speaker 370 to produce a periodic audible beeping tone. The audible beeping tone is presently tied to the aspiration function. It provides a tone which periodically beeps at a rate proportional to the aspiration rate. The audible beeping tone provides a continuous audible indication of the aspiration rate so that the surgeon does not need to look away from the surgical situs in order to determine the aspiration level.
Having given an overview of the microsurgical control system, a more detailed analysis of the circuit will now be presented.
The detailed schematic diagrams of FIGS. 4-17 have been provided with the customary pin designations where applicable. In these detailed schematic diagrams, many of the interconnecting leads and buses have been omitted for clarity; and it will be understood that the circuits with like pin designations share common signal lines and buses.
Referring now to FIG. 4, microprocessor 310 is illustrated. In FIG. 4, microprocessor 310 is also designated U1. The kernel address buffer 316 comprises two buffer circuits U27 and U28 which may be LS245 integrated circuits. The kernel data buffer 318 is implemented using buffer circuit U2 which may also be a LS245 integrated circuit. The DIR terminal of circuit U2 is responsive to the DIRKER* control signal and the E* terminal is responsive to the SELKER* control signal. The SELKER* control signal selects the kernel data bus as the active bus and the DIRKER* control signal controls the data flow direction. These control signals are generated by the buffer control circuit 324 which includes circuits U9 and U10, both programmable array logic chips, such as PAL16L8 integrated circuits. These circuits are coupled to the A11-A15 address lines and decode these lines to produce the control signals indicated in FIG. 4. Among the control signals provided are memory select signals MSN (MS0-MS7). These signals are used to select which of the memory chips is being accessed by microprocessor 310.
Also illustrated in FIG. 4 is EPROM 328 and nonvolatile RAM 330. These memory circuits are also designated U5 and U6, respectively. EPROM 328 may be a 2764 integrated circuit, while nonvolatile RAM 330 may be an HM6264-15 integrated circuit. As illustrated, EPROM 328 is enabled by MS7 memory select signal while RAM 330 is enabled by the MS0 memory select signal.
Also illustrated in FIG. 4 is peripheral decode circuit 334, which is also designated U7. This circuit may be a PAL20L10 integrated circuit. It provides the function selection and board selection by decoding address lines A4-A15. In addition to providing the BOARDn control signals (BOARD0-BOARD1), U7 also provides several other control signals indicated, including a control signal for operating dual UART 332. In addition to circuit U7, the peripheral decode circuit 334 also comprises circuit U8, shown in FIG. 6. Circuit U8 may be an LS154 integrated circuit which decodes address lines A0-A3 and provides a plurality of chip select signals CSn (CS0-CS15). As illustrated, circuit U* is enabled by the BOARD0* signal from U7.
Referring now to FIG. 5, the reset logic circuits 312 and watchdog circuit 314 are illustrated. The reset logic circuits provide an output at circuit U43 which is designated MPURST*. This signal is coupled to microprocessor 310 (FIG. 4) to provide a reset signal to the microprocessor. The reset circuits include a power on reset circuit 372 which couples to the reset logic circuit 374. The power on reset circuit provides a reset signal a sufficient time after powerup to ensure that the microprocessor is properly operating. Reset logic circuit 374, in addition to providing the microprocessor reset signal MPURST*, also provides hardware reset signals HDRST and HDRST* for resetting the peripheral devices connected to the system. This arrangement allows the microprocessor to be reset, to change memory banks for effecting different operations, for example, without requiring the hardware reset of the peripheral devices. The reset functions may be instigated by soft-ware control or by manually operated reset push buttons. The reset logic circuits 312 include a reset button control logic circuit 376 through which manual reset of both the microprocessor and the system can be accomplished using switches SW1 and SW2.
Watchdog timer circuit 314 is a resettable timer circuit. During normal operation, the microprocessor, acting through control signal WATCHDOGRST*, resets or reinitializes the watchdog circuit every 40 to 50 milliseconds. The watchdog reset control signal WATCHDOGRST* is provided by the dual UART 332, shown in FIG. 7. As long as the watchdog circuit is periodically reinitialized, it will not affect operation of the microprocessor. However, if not reinitialized after approximately 200 to 300 milliseconds, watchdog circuit 314 produces an output signal which causes the microprocessor reset signal MPURST* to be generated.
One purpose of the watchdog circuit is to reset the microprocessor and the system in the event the microprocessor loses program control due to a power surge or dropout. This is implemented by requiring the microprocessor to periodically generate the watchdog reset control signal as one of its many functions. If program control is lost, the microprocessor will not generate this control signal, whereupon the watchdog circuit 314 will cause a reset.
Another use for the watchdog circuit is in switching between memory banks. The control system of the invention employs several memory banks, which are discussed more fully below. These memory banks may be programmed to contain different sets of instructions, operating parameters, and the like. Normally, the microprocessor would operate based on instructions contained in one or more of the memory banks, with the remaining banks containing different instructions held in reserve for other users. For example, the memory banks may be programmed to display operating instructions in a variety of different languages: English, French, German, Japanese and so forth. In order to switch from one bank to another, the microprocessor executes program instruction code which appropriately changes the default memory to be selected. The microprocessor then purposefully fails to reinitialize the watchdog circuit, causing a reset to occur. When the reset occurs, the machine state reinitializes with the newly selected memory bank in place of the previously selected one. Also, if desired, hardware switches or jumpers may be used to determine which memory banks are active upon power up.
Also illustrated in FIG. 5, is the indicator driver circuitry 378 which is used to illuminate the LED indicators 42 above the couplers 40 on the front panel of console 12.
Referring now to FIG. 6, the system address buffers 320 and system data buffer 322 are illustrated. System address buffers 320 are designated U29 and U30 while system data buffer is designated U3. Like the kernel data buffer 318, the system data buffer 322 has its DIR and E* terminals connected to control lines DIRSYS* and SELSYS* which are provided by buffer control circuit 324.
FIG. 7 illustrates the dual UART circuitry 332 in greater detail. As illustrated, the dual UART circuitry includes a dual UART chip U4 which may be a 2681 integrated circuit. This circuit provides the various control signals indicated, including the watchdog reset control signal previously discussed. The dual UART circuit 332 provides two ports Port A and Port B, both complying with the RS232 standard. Although the uses of these two ports are many, one use is in loading new programs into the memory of the system. One of the ports can be connected to a remote terminal to receive commands, while the other terminal can be used to input the program to be loaded. In this fashion, the state of the machine can be monitored during the program loading procedure.
FIG. 8 depicts the universal memory sites 338 of the invention. These universal memory sites may be provided with either RAM or ROM, depending upon the desired application. The universal memory sites are presently illustrated as circuits U64-U68, which may be implemented using 2764 integrated circuits. As illustrated, each of these circuits is coupled to one of the memory select lines MSn (MS2-MS6). Also illustrated in FIG. 8 is EEROM ROM 340, also designated U69. This circuit may be implemented using a DS1216 electrically erasable ROM circuit. As illustrated, the EEROM 340 is coupled to the MS1 memory select line. Also illustrated for convenience is the system bas 380 to which the universal memory sites 338 and EEROM 340 are connected.
The key memory control circuitry is illustrated in FIG. 9. When the key K21 is inserted into jack J21, the key memory 342 is coupled to the KAn and KDn address and data bases. These buses are buffered through to the BAnSYS and BDnSYS system bases as illustrated. When the user physically turns the key in which the key memory 342 is encapsulated, a grounding signal is established with integrated circuit U32 (FIG. 12); and the KEY* signal enables the key memory 342 through Schmidt trigger 382.
With reference to FIG. 10, the digital potentiometer control circuits 344 are illustrated in detail. Presently four digital potentiometers are illustrated, although it will be recognized that a greater or fewer number may also be employed. Each of the digital potentiometers is coupled to a programmable array logic (PAL) circuit, designated U18-U21. These PALS or logic array circuits are used to encode the signals from the potentiometers in order to provide an input signal which may be readily counted by counter circuitry which is internal to the microprocessor. Additionally, it should be noted that while these potentiometers may continue to be endlessly turned in one direction or the other, the counter will not go below a zero value or go above its maximum value. These logic array circuits are coupled to the system bus BDnSYS as illustrated. Each logic array is activated by a given chip select line CSn (CS2-CS5). Each logic array provides a system interrupt request signal on the lead designated SYSIRQ*.
When any one of the "endless" digital potentiometers is turned, the corresponding array logic circuit issues a system interrupt request which is handled by the interrupt request circuit 368 shown in FIG. 12. Preferably the value of each digital potentiometer is stored in a software variable and is updated each time the setting of the potentiometer is changed.
FIG. 11 depicts the foot control pedal circuitry 346. The foot control pedal 24 is coupled by fiber optic cable 26 to the system console. A group of programmable array logic circuits designated U23, U24, U25 and U26 (FIG. 12) decode the foot pedal slide position settings indicative of the degree of rotation of the pedal about its generally horizontal axis of rotation. In addition to these values, the foot pedal also has an on/off switch which indicates that the foot pedal is in the fully up position. The foot pedal also has similar on/off switches which indicate when the foot switch has been moved to the right and left positions. These switches provide control signals via Schmidt triggers 384 designated FPUP, FPR and FPL.
FIG. 11 also illustrates the push button interface circuitry 348, comprising integrated circuits U11 and U12. The interface circuitry can be implemented using LS245 integrated circuits. The push buttons 18 (FIG. 1) are connected to jacks J6. Also connected to the interface circuitry 348 are the three control signals FPL, FPR and FPUP which are produced by the foot pedal switches discussed above. The circuits U11 and U12 couple all of the switches to the system bus BDnSYS.
The human actuable controllers are all transition detection interrupts peripheral devices. When the actuator setting is changed, a transition occurs which causes an interrupt signal to be generated. FIG. 12 illustrates the interrupt handling circuitry 368. The interrupt request handling circuit 368 includes integrated circuit U50 which may be an MC6840 integrated circuit. This circuit produces the system timer interrupt SYSFIRQ* which occurs every 40 to 50 milliseconds and is used for event counting and for resetting the watchdog circuit 314. This circuit also provides the audible beeping tone for driving speaker 370. Circuit 368 also includes logic gates 386 which are coupled to the foot pedal control signals FPUP, FPUR, FPR, FPRR, FPL and FPLR. The logic gates provide the system interrupt request signal SYSIRQ* which is coupled to U50 as shown.
FIGS. 13 and 14 illustrate the video portion of the control system. The video circuitry includes CRT controller 358 which may be a 6845 integrated circuit. The CRT controller is illustrated in FIG. 14 bearing the designation U47. Coupled to the CRT controller is data bus buffer U51 which buffers the system data bus BDnSYS to the video data bus BDnVID. The CRT controller provides the vertical and horizontal sync signals VSYNC and HSYNC, as well as other control signals as indicated.
The video RAM memory circuits 360 are illustrated in FIG. 13. They are coupled to the video address bus VAn and also to the video data buses UBDn and LBDn. Buffers 364 comprising circuits U34 and U35 provide the buffering between these data buses and the system video data bus BDnVID. Circuits U34 and U35 may be LS245 integrated circuits. The DIR terminal of those circuits are mutually coupled to the DIRSYS control line. In order to access video RAM 360, the microprocessor writes data to buffers 364 during a first half of the microprocessor machine cycle. This data is written to the display monitor screen during the second half of the machine cycle. A ten MHz. oscillator 356 provides the timing signal at which the video screen is refreshed during each other half cycle. Data is read from video RAM 360 into shift register (SR) interface circuits 362. This data is then shifted out at the ten MHz. rate into video signal processor circuit 354. The shift register interface circuits may be LS166 integrated circuits and are designated as U33 and U36 in FIG. 13. The signal processor circuit 354 is designated U58 and may be implemented using a PAL16R4 integrated circuit.
The output of signal processor circuit 354 provides the video and corresponding horizontal and vertical sync signals for driving the video monitor 352. Video RAM 360 is addressed using multiplexers U48, U49, U52 and U53, which are all implemented using LS157 integrated circuits. These multiplexers are in turn controlled by the timing and decoding circuitry 388 shown in FIG. 14. Timing decoding circuit 388 includes U38 which provides decoding for the video signal and U39 which provides timing for the system.
FIGS. 15, 16 and 17 depict the analog peripheral control circuitry which was designated generally by block 350 in FIG. 3. As noted above, many of the microsurgical implements are operated by fluid pressure signals. The control system console includes venturi pressure arrangement for providing the pneumatic signals used to control the surgical implements. The circuitry illustrated in FIGS. 15, 16 and 17 interfaces the microprocessor with the analog controlled valves (not shown) used to provide the specific pneumatic signals required by the surgical implements and by various pneumatically operated peripheral devices. In this regard, the presently preferred embodiment employs an illumination system with light dimming capabilities provided by a pneumatically controlled movable carriage. The analog peripheral control circuitry of FIGS. 15, 16 and 17 allow the microprocessor to control this light dimming device.
In addition, the cassette 100 for collecting aspiration fluids is also controlled by the analog circuitry. The cassette employs a light emitting diode and phototransistor pair for sensing the level of fluid within the cassette. This sensing mechanism provides an indication to the microprocessor of when the cassette is nearly full and needs to be replaced. The cassette is provided with a resilient-walled passageway which is blocked by squeezing action of a solenoid plunger operated by microprocessor 310. In addition to these functions, the analog circuitry also controls the BIPOLAR power used for cauterizing.
Referring more specifically to FIG. 15, the analog peripheral control circuitry couples to the microprocessor via the SYSAn and SYSDn system buses via jack J1. Interrupt requests from the analog devices are processed through logic gates U20 to provide interrupt request signal IRQ*. These two buses are buffered through buffers U4 and U5 while the interrupt request signals are buffered through U15. Referring to FIG. 16, which is a continuation of the schematic diagram of FIG. 15, the buffers U4 and U15 couple to the data bus D of the analog control circuitry, while buffer U5 couples to the address bus A of the analog control circuitry. The light dimming pneumatic controller is coupled to the control circuit via jack J2 and the cassette interface at jack J3. The BIPOLAR control circuitry is illustrated in FIG. 17.
In operation, the nurse or surgeon inserts cassette 100 into cassette slot 102, depressing it until it is locked into place. The act of sliding the cassette into place causes the aspiration vacuum system to be connected to the vacuum port of the cassette. The tubing for an aspiration instrument may then be inserted into the opening 148. At this time, the other surgical instruments are connected to the front panel couplers 40 as required. The fiber optic illumination instrument 214 is plugged into the fiber optic coupler 210. The system power switch 38 is then turned on, which causes powerup reset circuit 372 to reset microprocessor 310 after the appropriate time delay. In the presently preferred embodiment, the microprocessor controlled microcomputer system powers up in the initial function selection mode with the display screen 16 appearing as in FIG. 18. In this initial selection mode, only two of the switches 18a and 18b are active. The remaining push buttons and potentiometer knobs have no effect. In the screen region 22a, adjacent button 18a, appears the message "Anterior". In the screen region 22b, adjacent button 18b, appears the message "Posterior".
By depressing button 18a, the front panel display changes to display the anterior segment menu which provides the several different surgical procedures shown in FIG. 19. In addition to the surgical procedures offered on the menu, the user may also select information or help screens or the user may select return, which returns to the initial selection screen.
By pressing the button 18i adjacent the menu entry entitled "IRR ONLY", the screen displays a submenu which is illustrated in FIG. 20. This menu, in turn, offers other selections. Note that the IRR ONLY message is highlighted or emphasized in FIG. 20 and that two additional functions namely IRR PRIME and ASP PRIME, are added. FIGS. 21-24 illustrate the appearance of the display screen when the remaining selections are made from the menu of FIG. 19. With reference to FIGS. 21-24, it is seen that certain of the potentiometer knobs 20 have been made active and that adjacent each active knob there is a human readable indication of the function and current setting. In FIG. 23, for example, the cutting rate is indicated at 300 cpm, while the aspiration rate is indicated at 50 mm Hg.
Also shown in the display screen in FIG. 23, is the message indicating the actual aspiration vacuum level, as opposed to the maximum setting provided by the ASP potentiometer knob.
The remaining Figures relate to other functions provided by the control system and various menu levels of procedures selected from the initial selection menu of FIG. 18.
From the foregoing, it will be seen that the menus displayed on the screen change depending upon the selections made by the user. While the menus illustrated are in the English language, the invention is capable of displaying these menus in other languages as well, using the bank switching techniques previously described. In addition, the particular default setting of cutting rate aspiration vacuum, diathermy power, fragmentation power, etc. can be unique to each different surgeon who uses the control system, merely by inserting that surgeon's preprogrammed key into the jack on the system console.
While many of the functions are the same from menu to menu, certain groups of functions are mutually exclusive. The IRR ONLY, IRR/ASP and VITREOUS modes are mutually exclusive modes for the menu shown in FIG. 19. When one of these modes is in operation and a different one is selected, it automatically cancels the previous selection. Repressing the same mode switch a second time causes the mode to be cancelled. This allows other modes which may function simultaneously to be selected individually. For example, in the extracapsular mode, the user could select IRR ONLY and BIPOLAR allowing the foot pedal to control both of these functions. However, either function could be then eliminated by simply repressing its designated push button.
In the phacoemulsification mode, IRR ONLY, IRR/ASP, PHACO, and VITREOUS, FRAGMENTATION and SCISSORS are also mutually exclusive functions. BIPOLAR, ILLUMINATION and AIR EXCHANGE then become individually selected functions which can be used (in any combination) with one of those three principle functions, i.e. VIT, FRAG, and SCISSORS.
In all anterior segment procedures, both the IRR PRIME and ASP PRIME are illuminated. These allow the nurse or surgeon to reprime any of the lines without the need to access the surgeon's foot pedal. All posterior segment screens or menus, eliminate the IRR PRIME since continuous irrigation is generally used by the posterior segment surgeon.
The RETURN selection is continuously displayed to allow the user to traverse the menu screens without requiring the system to be shut off and reinitialized. The INFORMATION control button is a shift key which allows the user by depressing it to then select whichever modes information is desired. For example, if the user is in the extracapsular mode of FIG. 19 and depresses the information button while also depressing the IRR ONLY button, information about the IRR ONLY mode will be displayed on the screen.
With respect to the posterior segment menus (e.g., FIGS. 25-31), the selection of FRAGMENTATION preferably automatically cancels BIPOLAR, ILLUMINATION and/or AIR EXCHANGE modes since these are not used in conjunction with the fragmenter. Returning to a SCISSORS or VITREOUS mode thereafter requires the reinitialization of any of these modes desired. Also whenever VITRECTOMY and AIR EXCHANGE are selected together, the CUT RATE display will be extinguished and the AIR PRESSURE display illuminated and controlled by the appropriate potentiometer knob. Under such circumstances, the cutter will continue to function normally. Should the user require a change in cutting rate, the AIR EXCHANGE control is simply turned off to eliminate the cutting rate display in order to access the appropriate knob. The AIR EXCHANGE function can then be reinitiated.
In addition to the front panel controls, the foot pedal is also capable of controlling certain of the functions. Table I below describes the foot pedal functions for different surgical modes.
TABLE I______________________________________Mode Left Down Right______________________________________Anterior(Extracap &Phaco)IRR ONLY -- on/off --IRR/ASP Reflux IRR ONLY, -- on/off, linear 1 cycle aspirationPHACO Reflux IRR, ONLY on/off on/off, linear (momentary) 1 cycle aspirationVITREOUS Reflux IRR ONLY, -- on/off, cutting & 1 cycle linear aspirationBIPOLAR on/off -- -- (momentary)PosteriorVITREOUS -- linear on/off aspiration cutting (intermittent)FRAG- -- -- on/offMENTATION fragmentation (momentary)SCISSORS -- proportion proportionate/ or speed multicut (intermittent)BIPOLAR on/off -- -- (momentary)FIBEROPTIC -- -- --AIR EX- -- -- --CHANGE______________________________________
While the invention has been described in connection with its presently preferred embodiment, it will be understood that the invention is capable of certain modification and change without departing from the spirit of the invention as set forth in the appended claims. | The control system is programmable by the user by inserting a preprogrammed key into the system console. The key changes the default values normally used by the control system to those values selected by a particular surgeon. The control console thus emulates the performance characteristics of a wide variety of different types of microsurgical control systems, leaving the surgeon free to perform the operation without having to adjust to a new or unfamiliar system. The display screen is self-illuminating and provides a plurality of control menus generated by data stored in computer memory circuits. By bank switching the memory circuits, the display can be caused to appear in a wide variety of different languages. | 0 |
This is a nationalization of PCT/EP02/08357filed Jul. 26, 2002 and published in German.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a filter device having a housing, having at least two flow chambers separated from one another by membranes, having at least one connection for each flow chamber, and having at least one filter cap which is placed in the end region of the housing and is connected directly or indirectly thereto. Furthermore, the present invention relates to a housing of a filter device having at least two flow chambers separated from one another by membranes and having at least one end region which is connected to one of the flow chambers and is closable by a filter cap which may be put on the housing.
2. Description of the Prior Art
Filter devices of this type are used extensively in the fields of hemodialysis, hemofiltration, and hemodiafiltration. They typically include a housing in which a fiber bundle is positioned that includes multiple hollow fibers which separate two flow chambers from one another. While blood flows through the passages of the hollow fibers, the fiber outside space delimited by the chamber has dialysate flowing around it. The ends of the fibers are received in casting compounds located in the end regions of the housing. The casting compounds are typically extruded into casting caps in the end region of the housing. After sufficient hardening of the casting compound, the casting cap is removed and the cast cutting is performed, through which the fiber ends are opened. After the fiber ends are cut off, the filter caps are placed on the housing.
In previously known filter devices, each flow chamber is generally provided with two connections, through which the particular medium (blood/dialysate) is supplied and/or removed. These connections are located in the filter caps of the housing, so that the housing does not have any connections. Filter devices are also known in which the connections for the dialysate flowing around the hollow fiber bundle are positioned on the housing and the connections for the blood are positioned in the filter caps. A filter device in which all connections and/or connecting pieces are positioned in the filter caps is known from EP 887 100. In this filter device, all connections are aligned toward one side of the filter device and their center lines run parallel to one another. In this way, it is ensured that the filter device may be connected easily and reliably through plugging in to a filter or dialysis machines and/or a support in such a way that the connections or connecting pieces of the filter device form sealed connections with counter connections or counter connecting pieces.
However, a disadvantage of a filter device of this type is that because of tolerances during the placement of the filter caps on the housing, positioning problems arise as a filter device of this type is connected to the corresponding counterparts. These may lead to an optimal sealed connection not being provided between the connections and/or connecting pieces of the filter device and the corresponding counterparts, which may result in unsatisfactory functioning of the filter device and endangerment of the patient.
In order to avoid problems of this type during the positioning, it is suggested in EP 887 100 that the spacing of the connections of the holding part receiving the filter device be positioned precisely using a centering pin of the holding part in such a way that this spacing corresponds to the spacing of the connections on the filter device. Reliable connection is possible in this way, however, correction of this type is comparatively complex.
A filter device is known from U.S. Pat. No. 4,211,597 which does not include a housing and filter caps placed thereon, but rather two halves which are connected to one another in the lengthwise direction and receive the hollow fiber bundle. During the production of filter devices of this type, the filter housing is manufactured first and the hollow fiber bundle is manufactured separately therefrom in separate work steps. In a further manufacturing step, the hollow fiber bundle is placed in the housing halves and these halves are connected to one another fluid-tight.
It is the object of the present invention to refine a filter device according to the species in such a way that the positioning problems cited during the placement of the filter device on a holder do not occur.
SUMMARY OF THE INVENTION
This object is achieved, starting from a filter device according to the species, in that all connections for the flow chambers are positioned on the housing. The spacing of the connections and/or connecting pieces on the filter device is precisely determined in this way, so that the positioning problems cited may not occur. Tolerance variations during the production of the filter caps or during placement of the filter caps on the housing do not play a role for an optimum connection to the counterparts of a holder.
During the production of the filter device according to the present invention, the casting compound is extruded into the housing, a casting cap being put on which seals the end(s) of the housing. After extrusion of the casting compound and its hardening, this cap is removed and the fiber ends are cut off. The end cap(s) is/are now put on, tolerance variations being decisive neither in this work step nor in the production of the end cap(s) according to the present invention. The spacing of the connections and their alignment is independent of the execution and positioning of the filter caps, since all connections are positioned on the housing according to the present invention.
In a further embodiment of the present invention, the housing is implemented in the shape of a tubular section and two filter caps are provided which are put on both end regions of the housing and connected thereto. The housing is implemented in this case as a hollow cylinder which is sealed in both of its end regions using filter caps. According to the present invention, the filter caps have no connections, since all of these are positioned on the housing.
In a further embodiment of the present invention, two connections are provided for each flow chamber. In this case, one of the connections is used as an inlet for the blood to be purified and/or the fresh dialysate and the particular other connection is used as an outlet for the purified blood and/or the dialysate to be disposed of.
Two connections may be positioned in each of the end regions of the housing, which are positioned one above another or next to one another in the lengthwise direction of the housing. In both cases, one of the connections is connected to the chamber which blood flows through and the particular other connection is connected to the dialysate chamber. This may be achieved, for example, if the connections are received in a projection shaped onto the housing, and if corresponding lines which are connected to the connections and the flow chambers extend inside the projection.
In a further embodiment of the present invention, the connections have connecting pieces which extend in the radial or tangential direction in relation to the housing. For tangential positioning of the connecting pieces, it may be ensured through a corresponding design of the casting compound using blood guiding channels that the blood is distributed largely uniformly over the ends of the hollow fibers.
The blood connecting pieces may be implemented tangentially and discharge into a blood guiding channel extending at least partially around the circumference of the casting compound which encompasses the hollow fiber bundle of the filter device. The blood flows through the blood connecting pieces and subsequently the blood guiding channel, which extends partially around the circumference of the casting compound and using which the blood reaches the cut face of the casting compound and therefore the open ends of the hollow fibers. A tangential embodiment is, of course, also possible for the dialysate connection. In this case as well, a favorable flow of dialysate around the fiber outside space and therefore an optimum material exchange via the membranes may be achieved through suitable arrangement of the connection.
The end regions of the housing may have an enlarged diameter and a freely protruding projection of a smaller diameter which is embedded in the casting compound which receives a hollow fiber bundle. In this way, sealing of the dialysate chamber may be achieved without a further sealing means. The seal is produced by casting the freely protruding projection in the casting compound. The projection may have a force-ejected undercut collar that extends into the casting compound, which is typically made of polyurethane. The projection is typically made of polypropylene. The seal between blood and dialysate sides is performed by precisely pressing the casting compound against the projection through the shrinkage of the cast after its production. The freely protruding projection may be made especially adhesive through a plasma treatment, for example. Besides the cylindrical shape, further geometries, such as a “folded star”, are also conceivable.
The filter caps may be glued, welded, or screwed onto the housing.
In a preferred embodiment of the present invention, functional elements are integrated into or onto the housing, using which properties of the media guided through the filter device are detectable and/or changeable or the flow through the filter device may be influenced.
Functional elements of this type may include channels, valves, pumps, measurement chambers, filter and ventilation chambers and membranes. In this way, a highly integrated disposable may be provided which assumes not only the function of filtration, but also further important functions, such as ventilation, filtration, or even pumping. Functional elements of this type were previously generally positioned outside the dialysis disposable, the corresponding numerous connections between the individual components not only requiring complex production and assembly, but also resulting in corresponding seal problems. The functional elements may be positioned in the housing itself or even on the housing. In this way, an injection molded part containing many functions arises. A disposable of this type includes a single main body, and is therefore very material-saving and, particularly because of the connection processes dispensed with, is manufacturing-friendly and user-friendly and additionally seals well.
The housing and the filter caps may be manufactured from polypropylene.
In a further embodiment of the present invention, the connections have connecting pieces whose end regions lie in planes parallel to one another or in a shared plane. Depending on the embodiment of the holder on which the filter device is to be placed, corresponding different arrangements of the connecting pieces may be provided.
The connecting pieces may lie on a shared lengthwise plane or on lengthwise planes parallel to one another.
The present invention also relates to a housing of the filter device having at least two flow chambers separated from another by membranes and having at least one end region which is connected to one of the flow chambers and which is closable by a filter cap which may be put on the housing. Each of the flow chambers has at least one connection and all connections for the flow chambers are positioned on the housing.
The housing is preferably implemented according to one of the aforementioned housing embodiments.
Further details and advantages of the present invention will be described in greater detail on the basis of exemplary embodiments shown in the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic perspective illustration of a housing of a filter device according to the present invention,
FIG. 2 shows a side view of a filter device according to the present invention,
FIG. 3 shows a longitudinal section illustration of a housing of a filter device according to the present invention,
FIG. 4 shows a perspective illustration of a housing of a filter device according to the present invention having connecting pieces positioned next to one another,
FIG. 5 shows a cross-sectional view of the housing shown in FIG. 4 and a holder of a dialysis machine,
FIG. 6 shows a perspective illustration of an end region of a housing of a filter device according to the present invention having tangentially running connecting pieces,
FIG. 7 shows schematic lengthwise and cross-sectional views of an end region of the filter device according to the present invention having tangential connecting pieces, and
FIG. 8 shows perspective views of a housing of a filter device according to the present invention having tangential connecting pieces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
FIG. 1 shows a perspective illustration of the housing 10 of a filter device according to the present invention. The housing 10 is implemented in the shape of a tubular section. The two end regions of the housing are closed using filter caps 40 , 40 ′. The filter caps 40 , 40 ′ do not have any connections. The housing 10 has two connections 20 , 22 and 30 , 32 in each of the two end regions, which are implemented as connecting pieces 20 ′, 22 ′, 30 ′, 32 ′. Each of the connections 20 , 22 are connected to the chamber of the filter device which blood flows through and each of the other connections 30 , 32 are connected to the chamber of the filter device which dialysate flows through. The end regions of the connecting pieces 20 ′, 22 ′, 30 ′, 32 ′ are on a shared plane and, in addition, on a shared lengthwise plane. The position of the connections 20 , 22 , 30 , 32 is exactly fixed in the course of the manufacture of the housing 10 . When the filter device shown is connected to a corresponding holder of a dialysis unit, precise positioning and therefore a very well sealed connection may be achieved in this way. Positioning problems which arise in previously known achievements of the object using filter caps having connections are avoided in the filter device according to the present invention in that the filter caps do not have connections. Tolerance variations during the production or installation of the filter caps 40 , 40 ′ on the housing 10 therefore play no role in the exact connection of the filter device to a holder of a dialysis unit.
A hollow fiber bundle (not shown), which is fixed in the end regions by casting compounds which form a sealed connection to the housing 10 , is received in the housing 10 . The casting compounds separate the blood chambers, which are delimited by the filter caps 40 , 40 ′ and are connected to the connections 20 , 22 and to the passages of the hollow fibers, from the fiber outside space, which the dialysate flows through.
FIG. 2 shows a side view of a filter device according to the present invention. This filter device corresponds to the one schematically shown in FIG. 1 .
FIG. 3 shows a lengthwise sectional illustration of the positioning of the connecting pieces 20 ′, 22 ′, 30 ′, 32 ′ on the housing 10 . The crosshatched region shown on the right in FIG. 3 represents the casting compound 50 , which fixes the ends of the hollow fibers. The two connecting pieces 30 ′, 32 ′ distal from the end regions of the housing 10 are used to supply or remove dialysate into or out of, respectively, the fiber outside space enclosing the hollow fiber bundle. The connecting pieces 20 ′, 22 ′ are used to supply and/or remove blood. The blood is introduced into and removed from the filter device through the connections 20 , 22 and/or the connecting pieces 20 ′, 22 ′. These connections are connected to blood chambers which are formed between the filter caps and the casting compound 50 and into which the open ends of the fibers of the hollow fiber bundle discharge.
The connecting pieces 20 ′, 22 ′ may be connected permanently to the housing 10 or even screwed into a corresponding receiver.
An end region of a housing 10 of a filter device according to the present invention, in which the connections 20 , 30 and/or the connecting pieces 20 ′, 30 ′ are positioned next one another, is shown in FIG. 4 . The connecting pieces 20 ′, 30 ′ are formed here by an attachment positioned on the housing, in which channels extend that connect the connections 20 , 30 to the dialysate chamber and to the blood chamber. The end region of the housing 10 has an annular flange on which the filter cap (not shown) is placed and then connected to the housing.
FIG. 5 shows the housing shown in FIG. 4 and a holder of a dialysis unit in a cross-sectional view. The connecting pieces 20 ′, 30 ′ of the housing 10 are connected to corresponding counterparts 120 ′, 130 ′ of the holder 100 to form a seal. Because of the fixed predetermined positioning of the connections and/or connecting pieces on the housing 10 , correction devices on the holder, using which the position of the corresponding counterparts 120 ′, 130 ′ must be corrected, are not necessary.
The sealed connection between the connecting pieces 20 ′, 30 ′ and the counterparts 120 ′, 130 ′ is produced in the exemplary embodiment shown in FIG. 5 by O-ring seals received in the connecting pieces 20 ′, 30 ′.
FIG. 6 shows a perspective illustration of a housing 10 having tangentially implemented connecting pieces 20 ′, 30 ′, which have connections 20 , 30 , one of which is connected to the side of the filter device that blood flows through and one of which is connected to the side that dialysate flows through. The end region of the housing 10 has an enlarged diameter and a freely protruding, annular projection 80 of a smaller diameter, which is embedded in a casting compound (not shown in FIG. 6 ) that receives a hollow fiber bundle. This is shown in detail in FIG. 7 , FIG. 7 , top showing a sectional illustration in the lengthwise direction and FIG. 7 , bottom showing a sectional illustration in the transverse traction.
FIG. 7 shows the filter device in schematic and simplified lengthwise and cross-sectional illustrations. In the lengthwise sectional illustration shown in FIG. 7 , top, the outer contours of the filter device are not shown. Furthermore, the connecting piece 20 ′ is not shown in FIG. 7 , top.
As may be seen from FIG. 7 , top, the annular projection 80 of the housing 10 is embedded in the casting compound 50 . The seal between the blood and dialysate sides is produced by pressing the casting compound 50 against the cylindrical region 80 . This region has an undercut collar 82 , which extends into the casting compound 50 . Because of the pre-tension caused by the shrinkage of the casting compound 50 , the casting compound 50 presses against the projection 80 to form a seal. The seal between the blood and dialysate sides is produced here only by casting the projection 80 having force-ejected undercut collar 82 into the casting compound 50 . The projection 80 may be made more adhesive through plasma treatment. It may include not only the annular shape shown, but also other geometries, such as a “folded star”. In contrast to previously known achievements of the object, the seal is not produced through adhesion, but by pressing the casting compound 50 against the projection 80 using the pre-tension caused by the casting shrinkage.
The connecting pieces 20 ′, 30 ′ for blood and dialysate are positioned tangentially on the housing 10 , as shown in FIG. 7 , bottom. The cross-sectional illustration along line B—B is rotated by 180° in FIG. 7 , bottom in relation to the illustration in FIG. 7 , top. The section line of the projection 80 is not shown in FIG. 7 , bottom (section A—A). A blood guiding channel 60 is positioned in the casting compound 50 , which adjoins the blood connecting piece 20 ′ and which produces a connection of the blood connecting piece 20 ′ to the top of the casting compound 50 and therefore to the open end regions of the hollow fibers. In addition, the blood guiding channel 60 may be used for the purpose of distributing the blood supplied as uniformly as possible over the surface of the casting compound 50 . For this purpose, the blood guiding channel 60 may be implemented as rising in a spiral shape.
The housing 10 is closed by the filter cap 40 , which is connected flush to the housing 10 through a weld. A blood chamber is formed above the casting compound 50 by the filter cap 40 , from which the blood is guided into and/or out of the cavities of the hollow fibers.
As may also be seen from FIG. 7 , the filter cap 40 has no connections.
Finally, FIG. 8 shows perspective illustrations of the housing 10 of the filter device according to the present invention. It is clear once again from these that all connections 20 , 22 , 30 , 32 and/or the corresponding connecting pieces 20 ′, 22 ′, 30 ′, 32 ′ are positioned on the housing 10 . The weldable filter caps are used—as noted above—to delimit the blood chambers. In addition, they may have further functional elements such as air separation membranes.
The filter device according to the present invention not only allows simple connection to a holder of a dialysis unit having corresponding counterparts, but additionally allows the provision of a highly-integrated disposable. This may have functional elements, such as pumps, filters, measurement devices, control units, devices for temperature control, ventilation, etc. Because of the positioning of these functional elements in or on the housing, seal problems, which have occurred in previously known achievements of the object during the connection of these functional elements outside the housing, are dispensed with. In previously known achievements of the object, functional elements of this type are integrated into a complex tubing system, which may lead to seal problems because of the numerous connections and, in addition, is complex to produce and operate. In the achievement of the object according to the present invention, this problem may be solved through the integration of the functional elements into and/or on the filter device. For this purpose, no connectors are necessary, so that corresponding production difficulties (assembly, sterilization resistance) are dispensed with.
The further advantage results that the completely automated production of the filter device according to the present invention becomes significantly simpler, since the tolerances play no role for the precision of the connection during the production and/or during the placement of the filter caps. For the same reason, automatic connection of the disposable to the holder of the dialysis machine is made possible, which accordingly results in simpler handling.
The invention being thus described, it will be apparent that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims. | A filter device has a housing in the shape of a tubular section, with at least two chambers separated from one another by membranes, and with at least one connection for each flow chamber. The device has two filter caps, with one of each of the filter caps being located on each of the two end regions of the housing, and connected directly or indirectly thereto. All connections for the flow chambers are positioned on the tubular section in order to avoid tolerance variations that frequently occur during installation of the filter device. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Korean Patent Application No. 2006-0110884, filed on Nov. 10, 2006, which is incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates generally to multi-bank semiconductor memory devices and in particular, semiconductor memory devices having optimized memory block layouts and data line routing to enable chip size reduction and increase operating memory access speed.
BACKGROUND
[0003] Technological innovations in semiconductor fabrication technologies are driving market demands for semiconductor memory devices providing higher storage capacity, higher speed, higher integration density, and lower power consumption. The downscaling of semiconductor memory devices to submicron design rules and beyond, however, coupled with increased storage capacity poses technological challenges with respect to maintaining performance and reliability. For instance, as memory capacity increases and the pitch between adjacent patterns are made narrower, the layout of the memory arrays and peripheral devices become more problematic, especially with regard to memory core layout. When designing memory circuits, it is desirable to minimize the length and loading of word lines. Indeed, if word lines are too long/narrow and/or have too many memory cells connected to each word line (i.e., a large load), word line enable driver circuits will consume more power to drive the word lines, and the speed of driving word lines can decrease. To mitigate the impact on device performance with line rule downscaling and increased memory density, various memory circuit architectures have been employed including, for example, hierarchical memory bank architectures and hierarchical word line driver structures with sub word line architectures.
[0004] For instance, FIGS. 1A˜1C are schematic illustrations of a semiconductor memory device having a conventional hierarchical memory bank architectures and hierarchical word line driver framework. FIG. 1A illustrates a semiconductor integrated circuit memory chip ( 10 ) having a memory cell array with a memory capacity of 1 Gb, which is divided into a plurality of memory banks, Bank A, B, C and D (or more generally, Bank-i) (e.g., 4 memory banks of 256 Mb). Each memory bank Bank-i can be independently operated with associated peripheral circuits including column decoders ( 11 ) and row decoders ( 12 ), as well as other I/O circuitry for outputting/inputting data via peripheral data I/O pads ( 13 ). Each memory bank Bank-i comprises decoder circuits and core circuits that are arranged in “unit blocks,” as depicted in FIG. 1B . In particular, FIG. 1B schematically illustrates a conventional layout of each memory bank (Bank_i) in FIG. 1A , wherein each memory bank (Bank-i) comprises a plurality of 256 unit blocks BL(i) including 16 unit blocks along an x-direction (bitline/column direction) and 16 unit blocks along a y-direction (word line/row direction).
[0005] FIG. 1C schematically illustrates a conventional layout pattern for each unit block BL-i in the memory bank Bank-i for a memory device utilizing a hierarchical sub-word line driver scheme. Each unit block BL-i includes a cell array ( 20 ), sub-word line driver (SWD) arrays ( 21 ), bit line sense amplifier (BSLA) arrays ( 23 ) and conjunction circuit blocks including PXiD driver blocks ( 22 ) and LA driver (LADRV) blocks ( 24 ). The unit block pattern BL-i depicted in FIG. 1C is repeated in both x and y directions over the memory bank Bank-i such that each memory cell array block ( 20 ) is disposed between two BLSA blocks ( 23 ) in the x (column) direction of bit lines and such that each memory cell array block ( 20 ) is disposed between two sub-word line drivers ( 21 ) in the y (word line) direction. In one conventional hierarchical word line framework, each block sense amplifier ( 23 ) is shared by two memory cell array blocks ( 20 ) to the left and right of the BLSA ( 23 ) and each sub-word line driver ( 21 ) is shared by two memory cell array blocks ( 20 ) above and below the SWD block ( 21 ) using an interleaved layout framework, as is known in the art.
[0006] By way of specific example, FIG. 2 is a schematic illustration of one conventional framework of a unit block BL-i such as depicted in FIG. 1C in a semiconductor device having a hierarchical divided word line scheme. As shown in FIG. 2 , a memory cell array ( 20 ) includes an array of memory cells MC (each having a cell transistor and cell capacitor in a DRAM memory) located at the intersection of a bit line BL or BLB and a sub-word line WL. The bit lines are connected to the memory cells MC and to corresponding sense amplifiers SA in BLSA blocks ( 23 ) using an open bitline architecture, for example, as is known in the art. The BSLA blocks ( 23 ) are driven by control signals generated by drivers in respective LADRV blocks ( 24 ). In the hierarchical divided word line scheme, a word line is divided into a plurality of sub-word lines WL that are driven using corresponding sub-word line driver blocks ( 21 ) located above and below the memory cell array ( 20 ).
[0007] FIG. 3 , 4 and 5 are schematic diagrams to illustrate a conventional I/O architecture of for a multi-bank semiconductor memory device. In general, FIG. 3 is a schematic block diagram illustrating I/O circuitry for data read/write data paths for a conventional DRAM core comprising a plurality of banks. FIG. 4 schematically illustrates a layout arrangement of local and global data I/O bus lines providing a core data path from the memory cells and global bus lines for a multi-bank semiconductor device. FIG. 5 schematically illustrates a layout of the I/O circuitry and bus lines within the memory cell array regions and in peripheral regions of the memory arrays. FIGS. 3 , 4 , and 5 illustrate a typical device having an open bit line structure where bit lines BL and inverted bit lines BLB extend to both sides of a sense amplifier ( 23 i ) and where memory cells (MC) are formed at intersection region of the bit lines and word lines. Bit line pairs BL, BLB are respectively placed at both sides of each sense amplifier ( 23 i ) in a given array.
[0008] As shown in FIG. 3 , each sense amplifier ( 23 i ) is shared by two memory cell arrays and is connected to local data lines LIO and /LIO by pass gates M 1 , M 2 which are gated by the column select line CSL. As explained below, each column select line (CSL) may control multiple sense amplifiers per sense amplifier array, where each sense amplifier serves one data line pair. An LGIO multiplexer circuit ( 30 ) connects local data I/O line pairs LIO, /LIO to global data I/O line pairs GIO, /GIO. A GIO multiplexer circuit ( 31 ) connects the global data I/O line pars GIO, /GIO to data I/O line pairs DIO, /DIO at the input to a data read path and at the output of a data write path. The data read path includes IO sense amplifiers ( 32 ), a data bus multiplexer ( 33 ) and data output buffer ( 34 ) to output data to the appropriate output pads 13 upon memory read access operations. The data write path receives data input via the pads ( 13 ) at a data input buffer ( 35 ), a multiplexer circuit ( 36 ) and a data driver ( 37 ) to drive respective DIO line pairs.
[0009] To read out one or a plurality of data from the memory cells of the semiconductor memory device, the data stored in the cells are amplified in the bitline sense amplifier ( 23 i ). The data amplified in the bitline sense amplifier ( 23 i ) are transferred to the local data I/O lines LIO and /LIO) via a column selection line (CSL) switch, amplified in an LIO sense amplifier connected to the LIO bus, and then transferred to the global I/O buss. Data read from a selected memory block is transmitted to data line pairs DIO, /DIO via the GIO multiplexer ( 31 ). Data line sense amplifiers ( 32 ) sense data transferred via the data lines DIO and /DIO. The data line multiplexer ( 33 ) selects from among the output signals of the data line sense amplifiers ( 32 ), and transmits the selected output data signals to pads ( 13 ) via the data output buffer ( 34 ).
[0010] FIG. 4 schematically illustrates a layout structure of data lines from a memory cell to global I/O lines. As shown in FIG. 4 , the semiconductor memory device includes alternating odd and even numbered memory cell blocks ( 101 , 102 , 103 ) with array of sense amplifiers interposed between the arrays. The LIO bus lines include two pairs ( 110 ) and ( 111 ) local I/O lines LIO, LIOB that extends over the sense amplifiers (i.e., parallel to the word lines) between the arrays and service the bit line sense amplifiers located within an array. The global I/O lines extend parallel to the bit lines over the full length of the memory array. The LIO bus lines may be formed from a first metallization level whereas the GIO bus lines are formed using a second metallization level. In the exemplary embodiment of FIG. 4 , each CSL (column select line) is connected to the column switch circuit for 2 sense amplifiers on each side of the cell arrays and one CSL signal output form a column decoder ( 13 ) will activate the two pairs of sense amplifiers on each side of the cell arrays. This allows for DDR (dual data rate) memory access operations where 4 sets of LIO data can be transferred to the GIO lines for each CSL activation.
[0011] FIG. 5A illustrates an exemplary layout of the I/O circuitry and bus lines. As shown, the GIO bus lines extends over the entire memory bank towards a peripheral regions between the column decoders ( 130 ) of adjacent memory banks. The peripheral regions includes the GIO multiplexer circuit ( 31 ), the I/O sense amplifier circuit ( 32 ) and the DB multiplexer circuitry. Moreover, data I/O bus lines DIOB extend over substantially the entire length of the peripheral region between the top and bottom side of the memory banks and then extend across the top regions of the memory banks towards DOUT buffers and the DQ pads disposed at the peripheral edge regions of the semiconductor memory chip. Due to long lengths, repeater circuit ( 40 ) may be included along the DOIB bus lines. The repeaters ( 40 ) operate to buffer and transmit data on the DOIB lines between data pad and the DB multiplexer circuit ( 33 ) and thereby reduces the load and decreases the delay of the data signals of the DOIB lines.
[0012] When current sensing is used on the data lines, the transmission distances from the memory blocks to the data line sense amplifier vary. Accordingly, current from a memory block close to the data line sense amplifier travels a shorter length of the data lines and experiences less resistance on the data lines between the memory block and the data lines sense amplifier. Current from a memory block far away from the data line sense amplifier experiences more resistance on the data lines between that memory block and the data lines sense amplifier. Accordingly, the data line sense amplifier often has different sensing efficiency for different memory blocks. For instance, as shown in FIG. 5B , memory access operation to the upper left side of the memory bank (e.g., BANK A) must travel a long path along the GIO lines toward the column decoder ( 13 ) for the bank, and then up and down the FDIO and DOIB bus lines in the peripheral regions and then back towards the output pads over the top side of the memory bank A from between the column decoders ( 130 ). This can lead to differences in access times for read operations, which is particularly undesirable for a memory device such as a synchronous DRAM (SDRAM) where timing of data signals is critical. The problem becomes more significant for larger capacity memories because the relative differences in transmission lengths typically increase with an increase in the memory capacity and the integration density. Accordingly, a need exists for a semiconductor memory device capable of keeping the sensing efficiency of a data line sense amplifier uniform.
SUMMARY OF THE INVENTION
[0013] Exemplary embodiments of the invention generally include multi-bank semiconductor memory devices having optimized memory block layouts and data line routing to enable chip size reduction and increase operating memory access speed.
[0014] In one exemplary embodiment of the invention, a semiconductor memory device includes a memory array with a plurality of memory banks divided into a plurality of sub-banks. A first set of data I/O lines extend in a first direction between sub-banks, wherein the first set of data I/O lines are formed in a first metallization level. A second set of data I/O lines extend in a second direction, perpendicular to the first direction, across one sub-bank, wherein the second set of data I/O lines are formed in a second metallization level and connected to the first set of data I/O lines. A third set of data I/O lines extend in the first direction across the one sub-bank, wherein the third set of data I/O lines are formed in a third metallization level and connected to the second set of data I/O lines. The groups of data I/O lines are connected to I/O sense amplifiers disposed in regions of the memory array between adjacent banks.
[0015] In another embodiment, each subbank of a given memory Bank is arranged along a row in the first direction. Two banks have rows of subbanks that are adjacent to each other with word line decode circuitry interposed there between where two subbanks of a given bank may share a same column decoder for the bank.
[0016] The third set of data I/O lines are connected to I/O circuitry disposed in a central region between adjacent pairs of memory banks. A fourth set of data I/O lines connected to the I/O circuitry and extending in the first direction between the central region across one or more sub-banks toward a peripheral edge region and connected to I/O pads disposed on the peripheral edge region. The fourth set of data I/O lines are formed in the third metallization level.
[0017] These and other exemplary embodiments, aspects, and features of the present invention will become apparent from the following detailed description of exemplary embodiments, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1A˜1C are schematic illustrations of a semiconductor memory device having a conventional hierarchical memory bank architectures and hierarchical word line driver framework.
[0019] FIG. 2 is a schematic illustration of one conventional framework of a unit block BL-i such as depicted in FIG. IC in a semiconductor device having a hierarchical divided word line scheme
[0020] FIG. 3 is a schematic block diagram illustrating I/O circuitry for data read/write data paths for a conventional DRAM core comprising a plurality of banks.
[0021] FIG. 4 schematically illustrates a layout arrangement of local and global data I/O bus lines providing a core data path from the memory cells and global bus lines for a multi-bank semiconductor device.
[0022] FIG. 5A schematically illustrates a layout of the I/O circuitry and bus lines within the memory cell array regions and in peripheral regions of the memory arrays.
[0023] FIG. 5B schematically illustrates a data path for the read operation in the device of FIG. 5A .
[0024] FIG. 6 is a block diagram of a multi-bank semiconductor memory device according to an exemplary embodiment of the invention
[0025] FIG. 7 is an exemplary schematic diagram of a layout pattern of data I/O lines in a semiconductor device according to an exemplary embodiment of the invention.
[0026] FIG. 8 illustrates an exemplary layout of the I/O circuitry and bus lines of a semiconductor device according to an exemplary embodiment of the invention.
[0027] FIG. 9 schematically illustrates a data path for memory access operation a semiconductor device according to an exemplary embodiment of the invention.
[0028] FIG. 10 is an exemplary embodiment of a multibank semiconductor device according to an exemplary embodiment of the invention.
[0029] FIG. 11 schematically illustrates an memory access operation in a multibank semiconductor device according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0030] Exemplary embodiments of the invention will now be described more fully with reference to the accompanying drawings in which it is to be understood that the thickness and dimensions of the layers and regions are exaggerated for clarity. It is to be further understood that when a layer is described as being “on” or “over” another layer or substrate, such layer may be directly on the other layer or substrate, or intervening layers may also be present. Moreover, similar reference numerals used throughout the drawings denote elements having the same or similar functions.
[0031] FIG. 6 is a block diagram of a multi-bank semiconductor memory device according to an exemplary embodiment of the invention. FIG. 6 is an exemplary embodiment of a multi-bank semiconductor memory device in which memory banks are divided into subbanks to achieve a more uniform layout for data path lengths as well as the use of additional I/O bus formed on the cell arrays utilizing an existing metal layer to shorten the data path, which reduces the differences in access times for read operations, for a memory device such as a synchronous DRAM (SDRAM) where timing of data signals is critical. FIG. 6 illustrates a semiconductor integrated circuit memory chip ( 200 ) having a memory cell array with a memory capacity of 1 Gb, which is divided into a plurality of memory banks, Bank A, B, C and D (e.g., 4 memory banks of 256 Mb), a plurality of column decoders 211 a , 211 b , 211 c and 211 d associated with each bank, row decoders 212 a , 212 b , 212 c , 212 d and peripheral circuit blocks 214 , and peripheral pads including I/O pads ( 213 a , 213 b ) control/address signal pads 215 .
[0032] Each Bank is further divided into four sub-banks. In particular, the Bank A is divided into 4 sub-banks A 1 ˜A 4 , Bank B is divided into 4 sub-banks B 1 ˜B 4 , Bank C is divided into 4 sub-banks C 1 ˜C 4 and Bank D is divided into 4 sub-banks D 1 ˜D 4 . The sub-banks for each Bank include two pairs of sub-banks arranged adjacent to each other along rows and separated by corresponding column decoders. For instance, for Bank A, sub-banks pairs A 1 , A 2 and A 3 , A 4 are disposed adjacent to each other along a row and separated by column decoders 211 a . For Bank C, sub-banks pairs C 1 , C 2 and C 3 , C 4 are disposed adjacent to each other along a row and separated by column decoders 211 c . For Bank B, sub-banks pairs B 1 , B 2 and B 3 , B 4 are disposed adjacent to each other along a row and separated by column decoders 211 b . For Bank D, sub-banks pairs D 1 , D 2 and D 3 , D 4 are disposed adjacent to each other along a row and separated by column decoders 211 d . Moreover, row decoders 212 a / 212 c are provided between adjacent sub-banks of banks A and C in a row of sub-banks and row decoders 212 b / 212 d are provided between adjacent sub-banks of banks B and D in a row of sub-banks.
[0033] FIG. 6 depicts an exemplary embodiment of the memory device of FIG. 1 , wherein each 256 Mb Bank is divided into a plurality of smaller subbanks (e.g., 4 subbanks of 64 Mb) to achieve a more uniform layout. Moreover, an additional I/O bus is formed on the cell arrays utilizing an existing metal layer to shorten the data path. Accordingly, a semiconductor memory device capable of keeping the sensing efficiency of a data line sense amplifier uniform is required a multi-bank integrated circuit memory device is described including four banks, each of which consists of two sub-banks for lower byte data and upper byte data.
[0034] FIG. 7 is an exemplary schematic diagram of a layout pattern of data I/O lines in a semiconductor device ( 200 ) according to an exemplary embodiment of the invention. FIG. 7 is similar to FIG. 6 except for the addition of upper I/O data lines UIO ( 301 ) having data line pairs that connect to corresponding GIO line pairs, but extend orthogonal to the GIO lines and are formed on a different metal layer than the LIO or GIO lines, but on the same layer as the DIOB lines. The UIO bus lines ( 250 ) extends above the memory array perpendicular to the column decoder select lines CSL FIG. 8 illustrates an exemplary layout of the I/O circuitry and bus lines of the semiconductor device ( 200 ), which is to be compared with the conventional layout in FIG. 5 . The GIO bus lines extends over the entire memory bank towards a peripheral regions between the column decoders ( 211 a ) of adjacent subbanks of memory bank A. In FIG. 8 , GIO multiplexer circuit ( 231 ), I/O sense amplifier circuit ( 232 ) and the DB multiplexer circuitry ( 233 ) are disposed in the peripheral region between the rows of subbanks. The UIO lines ( 250 ) extend from the GIO lines over the cell array to the center peripheral region with I/O circuit ( 214 ). Moreover, data I/O bus lines DIOB extend over the cell array to the top regions of the memory banks and then towards the DQ pads ( 213 a ) Since the UIO extend over the cell array, the bussing lines in the peripheral region between the column decodes 211 is eliminated, thereby providing an area reduction.
[0035] FIG. 9 schematically illustrates a data path for memory access operation to the upper left side of the sub memory bank A 1 of memory bank (e.g., BANK A), where data that is read from the memory cell travels a short path along the GIO lines toward the column decoder ( 13 ) for the bank, and then down the UIO bus lines connected to the GIO line, input to the IO sense amplifiers ( 232 ) via the GIO multiplexer ( 231 ) and output over the FDIO lines to the DB multiplexer circuit ( 233 ) and then transmitted over the cell arrays of subbanks A 2 and C 2 of, where the data then travels a over a short path DOIB to the output buffer and pads. As compared to the data path of FIG. 5B , a more uniform data path length is achieved in FIG. 9 over all memory cells of the subbanks of a give bank.
[0036] FIG. 10 is another exemplary embodiment of a multiband semiconductor device that is similar in architecture to that of FIG. 6 , wherein repeater layers ( 260 ) are disposed between the row decoders for adjacent Banks, i.e., between row decoders 212 a and 212 c for subbanks A and C, and between row decoders 212 B and 212 D for subanks B and D. The repeater layers ( 260 ) include repeaters that can be connected to the DOIB bus lines or other buss lines that extend up and down over the rows of subbanks towards respective DQ pads 213 a , 213 b . With the exemplary layout of FIG. 10 , each memory bank A˜D shares the IOSA ( 214 ) in the center peripheral region. In particular, the subbanks of each Bank along a given column share the same IO sense amplifiers (e.g., A 1 , C 1 , B 1 , D 1 ) thereby resulting in a decrease in the amount of IOSA by half as compared to the conventional memory device of FIG. 1 , for example.
[0037] FIG. 11 schematically illustrates a method for performing a x32 DDR memory access with the multibank memory device of FIG. 6 . In this method, a total of 64 bits can be selected by activating all 32 I/O in Bank A, for example. In one clock cycle two Wordlines are activated and 4 columns select signals are activated. Since the column decoders 211 a separately control adjacent subbanks, A 1 , A 2 and A 3 , it is easier to control the access and I/O for the upper and lower DQ bits. Each CSL activate 4 sense amplifiers and thus selects 4 memory cells for a given WL activation. In this regard, 32 bits (4 cells×4 CSL×2 subbank) per one WL are selected. For example, subanks A 1 and A 3 can be activated on a first WL to access 32 bits for upper and lower DQs while subbanks A 2 and A 4 can be subsequent activated in the same clock cycle to access another 32 bits for upper and lower DQs.
[0038] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | Multi-bank semiconductor memory devices are provided having optimized memory block layouts and data line routing to enable chip size reduction and increase operating memory access speed. | 6 |
The present application claims priority to European Patent Application EP 00 105 569.8, filed Mar. 16, 2000.
FIELD OF THE INVENTION
The invention relates to a food cooler for the cooling, in particular deep freezing, of essentially flat and/or barlike foods produced as moldings, with a refrigerating space and with a conveyor belt for conveying the foods through this refrigerating space, the conveyor belt being assigned holding devices for the moldings.
BACKGROUND OF THE INVENTION
Food coolers of the type initially mentioned are known from prior public use, in which foods to be deep-frozen are laid onto a conveyor belt and are conveyed through the refrigerating space.
U.S. Pat. No. 2,254,420 discloses a food freezer with baskets arranged on a conveyor belt for the deep freezing of whole poultry bodies. The length of the baskets corresponds approximately to the greatest extent of the poultry bodies. U.S. Pat. No. 3,952,540 discloses a cooling appliance for the deep freezing of foods by means of refrigerating gas, in which holding devices for the foods are provided in the form of plate elements arranged approximately perpendicularly to the conveyor belt. The food reception spaces thereby obtained are delimited upwardly by a housing. The height of the holding plates corresponds approximately to the distance between them.
SUMMARY OF THE INVENTION
The object of the invention is to provide a food cooler of the type initially mentioned, in which the cooling operation proceeds more quickly and/or more efficiently.
The invention achieves this object in that the holding devices are designed for the defined holding of the moldings on the conveyor belt in a position inclined at at least 45° to upright.
The present invention provides food coolers for the cooling, in particular deep freezing, of essentially flat and/or barlike foods produced as moldings ( 3 ), with a refrigerating space ( 1 ) and with a conveyor belt ( 2 ) for conveying the foods through this refrigerating space ( 1 ), the conveyor belt ( 2 ) being assigned holding devices ( 6 ) for the moldings ( 3 ), wherein the holding devices ( 6 ) are designed for the defined holding of the moldings ( 3 ) on the conveyor belt ( 2 ) in a position inclined at at least 45° to upright. In some embodiments, the holding devices ( 6 ) are arranged with a spacing from one another which is smaller than the average extent of a molding ( 3 ) to be frozen. In alternative embodiments, the holding devices ( 6 ) are arranged with a spacing from one another which corresponds to the thickness of a molding ( 3 ) to be frozen, plus a clearance of at most 5 cm, preferably at most 3 cm, preferably at most 0.5 cm. In still further embodiments, the holding devices ( 6 ) are suitable for supporting the moldings ( 3 ) in a region which is at a distance from the lowest point of the moldings which corresponds to 50 to 100%, preferably 60 to 75%, of the molding width or molding height. In some preferred embodiments, the holding devices ( 6 ) comprise at least one holding rod ( 8 ) which extends approximately parallel to the conveyor belt. In additional embodiments, the holding devices ( 6 ) are gridlike. In some particularly preferred embodiments, the holding devices ( 6 , 12 ) have compartments for receiving food bodies. In further embodiments, a precooling stage ( 13 ) for precooling or prefreezing food bodies ( 3 ) is provided.
DESCRIPTION OF THE FIGURES
The invention is explained below by means of advantageous exemplary embodiments with reference to the following Figures.
FIG. 1 shows a diagrammatic side view of a food cooler.
FIG. 2 shows a view of a holding device fastened to the conveyor belt, from the conveying direction.
FIG. 3 shows a side view of a holding device fastened to the conveyor belt.
FIG. 4 shows a food cooler with a precooling stage.
DEFINITIONS
Some of the terms used within the scope of the invention will be explained first.
The term “cooling” may, on the one hand, mean cooling to temperatures of above freezing point, for example the cooling of heat-treated products from, for example, +70° C. to +10° C. Cooling also includes, in particular, deep freezing. Deep freezing (freezing) means that the foods are exposed for a sufficient period of time to a refrigerating medium of sufficiently low temperature, so that, after the freezing operation, a core temperature markedly below the freezing point of water prevails, as a rule below −18° C. The cooler is then designated as a freezer.
The refrigerating medium may be, for example, low-temperature gas or air which is cooled with the aid of compression refrigerating machines. In this case, heat exchange may be increased, if appropriate, by a convection flow being maintained in the refrigerating space with the aid of fans and cooling efficiency may be improved. The refrigerating medium may also be a low-temperature gas, condensed if appropriate, which is sprayed directly onto the food bodies.
“Moldings” within the meaning of the invention are all foods either which have from the outset a predetermined external shape recurring within the framework of the dispersions customary in foods or else which have been brought to a desired shape by means of a splitting or forming operation. Examples which may be mentioned are slivers or other preferably flat pieces of meat, fish fillets, fish fingers and the like.
In moldings formed essentially flat or else barlike, the smallest dimension (thickness) is markedly smaller than at least one of the other two dimensions in the other spatial directions (length or width). In an “essentially flat” food, the length of a so-called long side is greater by a multiple than the thickness, as a rule at least four times, six times or eight times the latter. In this context, “essentially” means that there may be deviations from the flat shape at individual points, without a generally flat character being lost thereby. The width of the flat foods is between the length and the thickness. In the case of a width corresponding approximately to the thickness, the food is essentially barlike. The discussion of flat foods also includes hereafter the barlike foods. The direction of the longest extent of the molding is designated hereafter as the “length.” The “width” is that direction perpendicular to the longitudinal direction which has the greatest extent. The “thickness” designates the direction perpendicular to the longitudinal direction and to the width.
Foods can be produced as sufficiently dimensionally stable moldings even at temperatures above a specific temperature, for example freezing point. They may consist, for example, of a homogeneous, sufficiently firm mass, for example a firm piece of meat. There may also be formed by a heterogeneous mixture of smaller ingredients, for example a vegetable mixture which is held together with the aid of a binding substance. It is therefore not the composition of a molding which is important, but solely the property of sufficient dimensional stability in a spatial arrangement of the molding under the effect of gravity. Also included are foods which, at temperatures, for example, above freezing point, consist of loose ingredients or, for example because of their water content, are not sufficiently dimensionally stable (soft pieces of meat), but, at temperatures below freezing point, are held together or stabilized by frozen liquid. In this case, when they enter the refrigerating space, the food bodies are already precooled to a suitable temperature, at least in the near-surface region. Cheese products are dimensionally stable, for example, at temperatures of below +40° C. They are therefore to be precooled correspondingly after the production process during which they reach temperatures of above +40° C. Finally, those foods are included which are not themselves dimensionally stable, but in which dimensional stability is achieved by means of packaging.
“Defined holding” within the meaning of the invention means that the moldings assume a spatial position on the conveyor belt which is predetermined by the holding devices. Within the scope of the invention, this may be any spatial position which deviates from the arbitrary position which a molding would assume on a flat conveyor belt without holding devices. In particular, there is provision, by the defined positioning provided according to the invention, for a larger part of the surface of the molding to be freely accessible to the refrigerating medium than if the molding were to rest, undefined, on the conveyor belt. Accordingly, as regards the flat or barlike moldings affected, the holding devices ensure that the moldings stand essentially with a narrow side on the belt, so that the largest part of their surface is freely accessible to the refrigerating medium. The holding of the flat moldings “in an inclined to upright position” refers to the angle which the area spanned in terms of length and width forms with the plane of the conveyor belt. Where barlike foods are concerned, this is the angle between the bar axis and the plane of the conveyor belt. This angle is at least 45°, preferably at least 60°, further preferably at least 75° to 90°. The underside is then formed by one of the narrow sides, in which case the longitudinal narrow side is often to be preferred for reasons of stability.
When the moldings are sprayed with condensed low-temperature gas or when a gaseous refrigerating medium is swept around them, the efficiency of cold transmission and therefore also the cooling rate depend directly on the freely sprayable or sweepable area. According to the invention, that fraction of the area of a molding which is not directly accessible to the refrigerating medium is preferably markedly reduced.
The term “conveyor belt” has a generalized meaning within the scope of the present invention. It designates an endlessly revolving conveying means for the conveyance of the food moldings over a predetermined conveying distance. It may consist of a unitary belt or of a plurality of members. The conveyor belt is not restricted to closed or sheetlike belts. Partially open versions, for example, chain conveyors known from the prior art, are advantageous, since they improve the accessibility of the underside of the food bodies lying on the belt to the cooling medium. Furthermore, the conveyor belt is not restricted to a belt which is flat in relation to the width. The extent of the conveyor belt perpendicularly to the conveying direction and to the lateral extent is, under some circumstances, no smaller than the width of the belt itself. As regards the dimensions of the conveyor belt, it is certain only that the belt length should be large in relation to the width and to the extent perpendicular to the latter. The conveyor belt is also not restricted to specific materials. It may, for example, consist of a plastic belt, but also be composed of metallic chain links. The length of the conveying distance predetermined by the conveyor belt is also independent of the extent of the refrigerating space. For example, the conveyor belt may be continued at one end or at both ends beyond the refrigerating space; it may also be that the conveyor belt does not extend at one end or at both ends as far as the edge of the refrigerating space. Moreover, the orientation of the conveyor belt is not fixed. While the conveyor belt will in many cases run horizontally, it may, under some circumstances, also be inclined, in so far as it can perform only its conveying function.
The refrigerating space is not restricted in terms of either its form or its nature, but is defined solely by its function of making available a refrigerating medium of sufficiently low temperature in a spatially delimited region and/or over a particular period of time. In the case of direct spraying with condensed gas, this is the space filled by the gas to be sprayed on. It is not even necessary, in this case, for the refrigerating space to be delimited materially by walls or in another way. It is also not necessary that the refrigerating medium be constantly available in the refrigerating space over a relatively long period of time; particularly when low-temperature gas is sprayed on directly, this may also take place in a pulsed manner. However, a space delimited by walls may be advantageous, in order to improve the refrigerating action of the refrigerating medium, fans also being used to maintain forced convection. In this case, expediently, inlet and outlet orifices (if appropriate, with cold locks) for conveying the food bodies respectively into and out of the cooler are provided in the cooler walls.
Nor are the holding devices restricted in terms of either the material or their form, but are likewise defined solely by their holding function. They may therefore be concrete devices, for example superstructures mounted on the conveyor belt or guides arranged above the latter. They may, however, also be, for example, depressions of any desired type in the conveyor belt. The holding devices may be separate parts or parts arranged on or above the conveyor belt and, if appropriate, fastened to the latter or be produced in one piece as part of the conveyor belt itself. They are suitably constituted and arranged in order to hold a food body to be cooled in a defined position on the conveyor belt. This is intended to refer to any position which deviates from the position which a food body to be cooled would normally assume on the conveyor belt if the holding devices were not present. In this context “normally” means that arrangements which are possible in principle, but are unlikely, can be ignored. The normally assumed position corresponds, as a rule, to that in which the food body has the lowest center of gravity. The feature of “defined positioning” therefore does not mean that the orientation of the moldings in relation to the conveyor belt is fixed, but the position is defined merely as deviating from the imaginary position which would normally be assumed without holding devices. If the holding devices are arranged above the plane of the conveyor belt, the position of a held molding is defined by a raised center of gravity, as compared with that of a molding lying on the conveyor belt without holding devices.
The invention recognized that flat moldings are positioned as “flat” as possible on a conveyor belt without holding devices under the effect of gravity, that is to say extend lengthways approximately parallel to the plane of the conveyor belt. As a result of the mass distribution of the molding being as “flat” as possible in the position without holding devices, the molding underside facing the conveyor belt forms a particularly large area. This is a disadvantage, since the molding surface facing the conveyor belt is less accessible or not accessible at all to the coolant, also because of the comparatively large amount of space required by the molding on the conveyor belt. By contrast, with the aid of the holding devices according to the invention, the moldings are held in an essentially inclined to upright position deviating from this unfavorable position. This leads to a reduction in a molding area facing the conveyor belt and therefore to an increase in the active area for the refrigerating medium and to a corresponding saving of space. As regards the flat foods affected, a saving of space and therefore an increase in efficiency are possible up to a factor which is determined by the ratio of width (or length) to thickness. The saving of space is limited, in practice, by the thickness of the holding devices and by some clearance between the holding devices and moldings.
The enlarged surface accessible to the refrigerating medium leads directly to an increase in efficiency in the case of the same overall length, since the necessary dwell time of the moldings in the refrigerating space is reduced. The conveying speed can be increased accordingly, thus leading directly to an increase in the throughput rate. Alternatively, the conveying speed can be kept constant and the overall length shortened correspondingly. It is also possible both to increase the throughput rate by a smaller amount and at the same time reduce the overall length by a corresponding amount. Finally, it may also be desirable to keep the overall length, the conveying speed and consequently the dwell time of the moldings in the cooling space constant. The improved cooling efficiency can then be used, for example, for lowering the temperature of the refrigerating medium, specifically until the cooling result corresponds to that of a conventional cooler without holding devices. This entails a saving of energy and therefore of cost.
The reduction in the area occupied by the moldings in the plane of the conveyor belt may be used, in particular, to arrange the moldings on the conveyor belt more densely. This results, in the case of a constant conveying speed, in an increase in the throughput rate. Similarly, instead of this or in combination with it, a shortened overall length or a reduced energy requirement of the cooler or freezer can be achieved.
Preferably, the conveyance of the moldings takes place with a long side oriented either transversely or parallel to the conveying direction. In the case of conveyance with a long side transverse to the conveying direction, the supporting parts of the holding devices are arranged essentially transversely to the conveying direction and are expediently fastened to the conveyor belt. Depending on the dimensions of the conveyor belt and moldings, a plurality of these can be conveyed next to one another.
In the case of conveyance with a long side parallel to the conveying direction, the holding devices or their supporting parts are arranged essentially likewise parallel to the conveying direction. They may, in this case, be fastened to the conveyor belt and be conveyed concomitantly. Advantageously, however, these are in this case fixed holding devices which are arranged above the conveyor belt and which extend over the entire conveying distance. The advantage of this arrangement is that fastening of the holding devices to the conveyor belt can be dispensed with. The conveying force is in this case generated by the friction between the moldings and the conveyor belt. Advantageously, a plurality of holding devices of this type are arranged parallel to one another, in order to increase the conveying capacity correspondingly. For example, by means of appropriate grids, a plurality of guide ducts can be formed, which are arranged above the conveyor belt and parallel to the conveying direction and through which a plurality of rows of moldings are conveyed next to one another on edge (with a narrow side lying on the conveyor belt).
In order to utilize the reduced area of the moldings and bring about a saving of space, the holding devices are arranged with a mutual spacing which is smaller than the average extent of a molding. The mutual spacing corresponds advantageously to the thickness of the moldings plus a clearance which may amount to 5 cm, but will often be smaller than 3 cm or 5 mm. By the holding devices being arranged closely to one another, there is an improvement in the saving of space. This concerns holding devices arranged both transversely and parallel to the conveying direction.
The holding devices are preferably designed to be as open as possible, that is to say essentially permeable to the refrigerating medium. The more open the holding devices are in this case, as compared with the conveyor belt, the greater is the increase in cooling efficiency brought about by the increased surface accessible to the refrigerating medium. For example, gridlike holding devices which are arranged transversely or parallel to the conveying direction may be envisaged. The moldings are positioned by lying at least partially against the grid or, in the case of an inclined orientation, on the latter. The permeability of the grid may be improved by the grid meshes being enlarged, specifically up to a mesh size in the region of the length or width of the molding. The holding devices are assigned to the conveyor belt. This means that they have a defined spatial arrangement in relation to the conveyor belt. Within the scope of the invention, the holding devices may be fastened to the conveyor belt and run concomitantly with the latter, alternatively they may be arranged fixedly, for example above the conveyor belt, and guide ducts may be formed, which extend in the conveying direction of the belt and through which the moldings run.
A holding device may also consist of an expediently arranged plurality of holding rods, the transitions to the grid form being smooth. Under some circumstances, a single approximately horizontal holding rod transverse or parallel to the conveying direction may be sufficient for performing the positioning function. The terms “horizontal” and “vertical” relate here and hereafter to the plane of the conveyor belt. Expediently, this holding rod is suitable for supporting the moldings in a region which is at a distance from the lowest point of the held molding which corresponds to 50 to 100%, preferably 60 to 75%, of the molding width (or of the molding height if the underside of the positioned moldings is the short narrow side). On the one hand, for reasons of stability, the distance should not be too low, in particular the upper supporting point should not lie below the center of gravity. On the other hand, there should be a sufficient safety distance from the top edge of the positioned moldings. In the lower region, the moldings can be additionally supported with the aid of holding devices, for example an approximately horizontal holding rod. Further approximately horizontal holding rods may be provided in between, for example, in order to prevent sagging or slipping in the case of a food body which is not entirely dimensionally stable. The horizontal holding rods are expediently held by vertical rods which, if appropriate, may be fastened to the conveyor belt.
In the case of holding devices arranged essentially transversely to the conveying direction, lateral holding parts may be provided, which prevent the moldings from drifting out laterally. These parts may likewise be gridlike or rodlike. The lateral holding parts may be expedient particularly in the case of round moldings, for example potato waffles. In this form, the holding devices provide compartments for receiving the food bodies.
As already mentioned, the term “molding” also includes those foods which do not have the presupposed dimensional stability at temperatures above a specific temperature (for example, freezing point), either because they are too soft or because they consist of individual ingredients held together only loosely. In this case, it is expedient to provide at the inlet end of the refrigerating space, a precooling stage in which the foods are precooled appropriately in order to generate the desired dimensional stability, for example to a temperature just below the dimensional stability temperature. In this case, partial cooling or freezing of the foods, for example in their near-surface region, may even be sufficient. The precooling stage is not restricted to an arrangement directly adjacent to the cooling space. For example, a further conveying distance may be arranged between the two cooling spaces. It is essential merely that the precooling precedes in time the cooling in the refrigerating space and that the food bodies, when they enter the refrigerating space, have sufficient dimensional stability.
DESCRIPTION OF THE INVENTION
A food cooler comprises a refrigerating space ( 1 ), in which is arranged a conveyor belt 2 for conveying food moldings ( 3 ) through the refrigerating space. Inside the refrigerating space ( 1 ) are provided cold generation devices, not shown, which generate, within the refrigerating space ( 1 ) or at least in the region through which the food bodies ( 3 ) run, a refrigerating medium, in the simplest case air, with a temperature sufficiently low for the deep freezing of the food bodies. The food bodies ( 3 ) enter on the inlet side ( 4 ) of the refrigerating space at an initial temperature, for example, in the range of +5° C. to +20° C., the inlet temperature also being capable of being substantially higher (up to 80° C.) than or just below freezing point (down to −4° C.). The cooling capacity, the length of the conveying distance in the refrigerating space (L) and the conveying speed of the conveyor belt ( 2 ) are dimensioned such that the food bodies ( 3 ) leave the refrigerating space ( 1 ) on the outlet side ( 5 ) in the cooled, for example deep-frozen state, that is to say with a core temperature of, for example, −18° C. or below. The conveyor belt ( 2 ) is designed as a chain conveyor which is partially permeable to the refrigerating medium. In the case of cryogenic freezing by a low-temperature condensed gas being sprayed on directly, spray nozzles are arranged above the plane (E) of the conveyor belt and preferably also below this. Both as regards cold generation by means of compression refrigerating machines and as regards cryogenic freezing, fans, not shown, for maintaining convection within the refrigerating space ( 1 ) may advantageously be provided, which accelerate the heat exchange and increase the freezing efficiency.
The food bodies ( 3 ) are flat moldings, for example pork cutlets, which have sufficient dimensional stability even before they enter the refrigerating space ( 1 ). In the example mentioned, they have dimensions of approximately 120 mm×80 mm×15 mm.
Holding grids ( 6 ) are fastened with regular spacing to the conveyor belt ( 2 ). As is evident from FIG. 1, they hold the moldings ( 3 ) in an essentially vertical position, in which their underside is formed by the longer narrow side (120 mm×15 mm). The moldings ( 3 ) are oriented transversely to the conveying direction and extend vertically by their width of 80 mm above the plane (E) of the conveyor belt. The positioning of the moldings ( 3 ) which is achieved with the aid of the holding grids ( 6 ) deviates from the position which the moldings would assume without the holding devices ( 6 ), to be precise a position lying flat, in which the moldings ( 3 ) would extend above the plane E of the conveyor belt merely by their thickness of 15 mm. In the case of an arrangement transverse to the conveying direction, each molding would extend 80 mm in the conveying direction, which is more than five times as much as the corresponding extent of the moldings ( 3 ) in the upright position.
The holding grids ( 6 ) are arranged along the conveyor belt ( 2 ) with a mutual spacing d of 25 mm. This corresponds to the thickness of the flat moldings 3 of 15 mm plus a clearance of 10 mm. The spacing (d) is therefore substantially smaller than the average extent of 65 mm of the moldings ( 3 ) (the average extent is determined by the diameter of a sphere of the same volume). The spacing (d) is to be compared with the abovementioned extent of the moldings ( 3 ) in the conveying direction without the holding grids ( 6 ) (80 mm), plus a mutual spacing of approximately 20 mm. Over the same conveying distance, therefore, with the aid of the holding grids ( 6 ), more than four times as many moldings ( 3 ) can be positioned transversely to the conveying direction as in the case of a corresponding arrangement without holding grids ( 6 ). Consequently, with the conveying distance length (L) being the same and the conveying speed being unchanged, the throughput rate of the moldings ( 3 ) through the freezer increases by the same factor. Alternatively, the increase in capacity may be used for reducing the conveying length (L) and/or for reducing the energy consumption, as explained above.
As is evident from FIG. 2, the holding devices ( 6 ) are gridlike, the size of the grid meshes both in the vertical and in the horizontal direction, corresponding to 0.2 to 0.5 times, preferably to 0.3 to 0.4 times, the width or length of the moldings ( 3 ). The holding grid ( 6 ) is formed by a plurality of interconnected rods consisting, for example, of high-grade steel. A holding device ( 6 ) comprises a holding rod ( 7 ) which extends horizontally transversely to the conveying direction. As is evident from FIG. 3, these holding rods ( 7 ) are suitable for supporting the moldings ( 3 ) at a point which is at a distance s from the lowest point a of the moldings which corresponds to approximately 70% of the molding width. The molding ( 3 ) is thereby supported reliably in the upper region. Support at the lower end may take place, for example, by frictional connection with the conveyor belt ( 2 ) or by support on one of the rods of the adjacent holding grid 6 . Below the supporting rod ( 7 ), further horizontal rods ( 8 ) may be provided, which serve for increasing the stability and/or, where not entirely dimensionally stable food bodies are concerned, prevent sagging or slipping underneath the supporting rod ( 7 ). The horizontal supporting rods ( 7 ), ( 8 ) are fastened to two or more vertical holding rods ( 9 ) which, in turn, are fastened to the conveyor belt ( 2 ) at ( 10 ). The rods ( 7 ), ( 8 ), ( 9 ) forming the holding grid ( 6 ) have a thickness which is small in comparison with the molding thickness. In the present example, it may be in the range of 3 to 4 mm. The vertical holding rods ( 9 ), in particular a rod ( 11 ) arranged between the outer rods, may also contribute, in particular, to supporting the moldings ( 3 ) in the lower region.
As indicated in FIG. 3 with the aid of broken lines, lateral strutting ( 12 ) of the holding grids ( 6 ) may be provided, in order to prevent the moldings ( 3 ) from slipping or drifting out. By virtue of the lateral holding rods or holding grids ( 12 ), the holding devices ( 6 , 12 ) acquire, in general, the form of compartments for receiving the moldings ( 3 ).
If the food bodies ( 3 ) are not readily dimensionally stable by nature or as a result of the production process, a precooling stage ( 13 ) for precooling or prefreezing the food body ( 3 ) is expediently arranged at the inlet end ( 4 ) of the refrigerating space ( 1 ). This may be a further refrigerating space ( 13 ) and a conveyor belt ( 14 ) which is arranged therein and on which the food bodies ( 3 ), lying flat, are guided through the refrigerating space ( 13 ), sufficient dimensional stability being achieved, at least in the outer region, as a result of the precooling of the moldings ( 3 ). When they enter the refrigerating space ( 1 ), the moldings are introduced into the interspaces formed by the holding grids ( 6 ) and preserve their form in the upright position when being conveyed through the refrigerating space ( 1 ). In the example of FIG. 4, because the food bodies ( 3 ) are arranged so as to lie flat, the conveying speed of the conveyor belt ( 14 ) in the cooling space ( 13 ) is substantially higher than the conveying speed of the conveyor belt ( 2 ). | The present invention provides food coolers the cooling, in particular deep freezing, of foods produced as moldings ( 3 ) comprising a refrigerating space ( 1 ) and a conveyor belt ( 2 ) for conveying the foods ( 3 ) through this refrigerating space ( 1 ). The conveyor belt ( 2 ) is assigned holding devices ( 6 ) for the defined positioning of the moldings ( 3 ) on the conveyor belt ( 2 ). | 5 |
RELATED APPLICATIONS
This application claims priority benefit of U.S. Ser. No. 60/889,710, filed Feb. 13, 2007.
BACKGROUND OF THE DISCLOSURE
Motorcycle tire and wheel assemblies are generally constructed of steel or alloy rim with a latticework of spokes that attach the rim to the hub. They may also be constructed of a cast alloy hub/rim assembly with open cutaway spaces between the rim and hub. Either type of wheel assembly would applicable to this invention.
Acceleration and deceleration of the motorcycle or other vehicle tends to cause the tire to rotate on the rim. Rotation of the tire on the rim is not desirable because it can cause the wheel assembly to become unbalanced. In the case of tubed tires (an inner air-filled bladder within the tire carcass) any rotation of the tire can cause the tube's valve stem to tear away from the main tube bladder, leading to a sudden and catastrophic loss of air pressure. In the case of tubeless tires (no inner air bladder) rotation of the tire on the rim can cause a gradual loss of air pressure, with an eventual loss of bead-to-rim contact, and potential catastrophic loss of air pressure.
When a rubber motorcycle tire is mounted to the metal hub/spoke/rim assembly, it is held in place with a combination of air pressure, tension of the rubber tire itself which exerts an outward (sideways) force, and friction between the rubber tire sidewall and the metal rim. Often the motorcycle manufacturer or tire installer uses special lubricant/adhesive solution that literally “glues” the rubber tire in place on the rim. Even without this solution the rubber tends to “fuse” itself to the rim over time and tire removal can become very difficult.
Additionally, motorcycle tires are often mounted on what's called “safety rims” or “locking rims”. The design of these rims is such that the tire's sidewall and annular bead is retained in such as manner as to prevent movement of the tire within the rim, when subjected to the high stresses involved in turning or cornering maneuvers. The design of these rims makes tire removal nearly impossible without specialty tools.
When it's time to change a motorcycle tire due to road wear or to make a repair of the tube or otherwise perform any repairs on the tire, it is necessary to “break the bead”. This is a commonly used term that refers to the process of breaking the adhesive and/or mechanical seal between the rubber sidewall of the tire, and the rim itself. Due to the design of modern tires, which are physically wider than the rim itself, and because of the widespread use of lubricant/adhesives holding the tire in place on the rim, this process can be extremely difficult (if not impossible) unless you have proper tools.
The process of changing or repairing a tire on an automobile is considered relatively easy because nearly every car has a spare tire, and when a flat tire has been removed from the automobile almost every service station has the necessary professional equipment and training to fix or replace an automotive tire.
However, the process of changing or repairing a motorcycle tire is a different story because most motorcycles can't carry spare tires. Motorcycle shops are few and far between so whenever a motorcycle has a flat tire the rider is often forced to make roadside repairs using whatever tools he/she might carry with them. The alternative is to call for a towing service and have the motorcycle hauled to the dealership for repair.
For those who attempt to repair motorcycle tires or for those who change their own tires when the tires become worn, the first step in the process is to deflate the tire (in the case of a flat tire this has already occurred). The second step is to remove the tire and wheel assembly from the motorcycle. The third step is to “break the bead” or otherwise break the seal between the rubber tire and the metal rim. Finally the tire can be removed from the rim and repaired or replaced.
Currently there are very few (if any) tools compact enough, lightweight enough, or otherwise suitable for this process. Motorcyclists have responded to this lack of suitable tools by concocting a variety of expedient devices, including C-clamps (or modifications thereof), or wedges driven between the tire and rim using a hammer or mallet, or some sort of pure brute force method, including jumping up and down on the side of the rubber tire (while trying to avoid jumping on the rim itself).
One popular technique is to use a second motorcycle's side stand as a tool to wedge between the tire and rim, while rocking the second motorcycle so that its' weight presses down on the side stand and hopefully breaks the bead. This method may work but often results in damage to the side stand, as well as damaging the rim. Whatever method is used the process is difficult and sometimes dangerous. It may be necessary to exert a force of more than 500 pounds to break the seal between the metal rim and tire. As rubber tires get older this bead breaking process becomes even more difficult because the rubber compounds become stiffer and less pliable. Also, as ambient temperatures drop the process becomes increasingly difficult.
This embodiment utilizes a simple fulcrum and lever device that compounds the user's downward weight, thereby forcing a wedge-shaped plunger member into the space between the rim and wheel. With sufficient extension of the lever the force exerted can easily exceed 1000 pounds, which has proven to be more than enough force to unseat a motorcycle tire bead from a rim.
This embodiment can be used in any location having a flat, relatively hard work surface. The tire assembly must first be removed from the motorcycle and placed in a horizontal position; in other words, the wheel assembly must be resting flat on the ground.
This embodiment can also be used in any location having a flat, soft surface such as sandy soil or bare earth. This can be accomplished by the addition of wooden or metal strips fixed at perpendicular angles to the device, placed so as to widen the “footprint” of the device and prevent it from sinking in the soil when downward pressure is applied to the embodiment or to the tire assembly.
Although the working model of this embodiment is sized as shown in the drawings, production models could be constructed to any scale, depending on the need of the user or the size of the wheel assembly.
Once the motorcycle operator has successfully “broken the bead” on the tire, they must then make repairs to the tire. This requires removing the pneumatic tire from the metal rim. This is done with a set of two or three metal “tire irons”, which are essentially flattened pry bars.
Tire irons can be of varying size and shape, but for practical purposes and ease of carry on a motorcycle they should be as compact and lightweight as possible. The typical tire iron used for this embodiment is about 0.25″ thick, 0.75″ wide, and about 8″ to 10″ long. Each end of the tire iron is shaped and designed to make tire removal process as easy as possible, and smooth to prevent damage to the tire carcass or the inner tube.
To remove a tire from a metal rim the user places a tire iron between the metal rim and the pneumatic tire and using the leverage provided by the tire iron forces the circumferential inner bead of the tire over the edge of the rim. The user repeats this process around the tire assembly until one side of the tire comes off the rim. The user then repeats the process on the remaining tire sidewall until the tire has been completely separated from the rim. At that point the tire can be repaired, replaced, or the inner tube can be repaired or replaced.
To install a tire on a metal rim the user places a tire iron between the metal rim and pneumatic tire and forces the tire bead over the edge of the rim, then repeats the process around the tire until the tire is on the rim. The user repeats the process on the other sidewall of the tire until the tire is fully onto the rim, at which time the tire is filled with air. In the case of a tubed tire the tube is inserted into the tire before the second sidewall is forced onto the rim.
SUMMARY OF THE DISCLOSURE
What is disclosed herein is a tool called a bead breaker for breaking a circumferential bead of a motorcycle tire from an associated rim comprising a plurality of parts. A group of tire irons, which are similar to those already known in the art, but in general will be described as a leveraged tire iron, a support tire iron, and the base tire iron. The tire irons are configured to couple either to extend the driving force of a user against the tire for separating a tire from a rim or alternatively to support said driving member in a vertical or horizontal orientation. The driving member comprises a channel-like apparatus which has a hole in one end for locating a pivot pin and a channel disposed in the opposite end for inserting one of the previously mentioned tire irons to extend the driving force. The central portion of the driving member is configured to accept a plunger member which directly couples to the tire. This connection between the driving member and the plunger member could be adjustable in its X&Y directions and should in one form be a pivotal connection. The plunger member is configured to pivot about the middle portion of the driving member and may have on one end a specifically designed tire engagement portion. An angle portion herein discussed as a base elbow is also disclosed wherein a first end of the base elbow is configured to fixedly and position-ably engage a support tire iron which forms the base portion of the apparatus when in use. The base elbow has a portion of which is generally an angle bracket and a second end which is configured to fixedly and positionably engage the end portion of the support tire iron. The support tire iron is substantially vertical in orientation to the ground when in use and having on its opposite end a pivotal engagement with the driving member.
When in use, the bead breaker will exert tremendous force upon the sidewall of the tire and may thus exert force upon the rim or wheel portion. As the assembly is substantially made from metallic parts, a plurality of scratch guards may be formed to temporarily and removably couple to and protect the base elbow from scratching the wheel.
One of the easiest ways to assemble the apparatus in one form is to utilize quick release pins which are common in the art. As these quick release pins are often very small, they may be connected by way of a lanyard which may be a bright color or otherwise aid in maintaining the quick release pins from being lost or misplaced.
As previously stated the bead breaker in operation may exert significant force against the tire portion and some of this force may be directed outward which will tend to slide the wheel and tire away from the base elbow and the vertical support tire iron. Thus, a lock bar which is slideably engaged with the base tire iron. As tires and wheels come in a wide variety of diameters and sizes it may be desirable that this lock bar be positionable along the length of the base tire iron.
As shown in the accompanying figures, it is possible to construct this apparatus using a plurality of tire irons which are each identical to one another. This would aid in construction and would also aid in manufacture and assembly.
Often it is desired to form a stable support base for this apparatus. For example, it may be necessary to remove a tire from a wheel where the only hard or flat surface available is soft such as sand or loose dirt. Thus, a base member is also disclosed which forms a larger and wider support structure for the assembly.
Recent advances in chemicals have created fluids which aid the removal of tires from rims. Once the bead has been broken between a tire and a wheel, application of this fluid may maintain the separation and keep the tire from re-adhering to the rim.
If the tire is not wholly damaged, it may be desired to remove the remainder of the air pressure from within the tire to aid in its removal. Thus a valve stem multi-tool may also be included which has a plurality of devices applicable to releasing the air from a tire or inner tube. The multi-tool may also be configured to aid in the replacement of a valve stem.
Once the bead has been broken, the tire irons are utilized to lever the tire around the rim. This may damage the rim which is obviously undesired. Thus, the plurality of rim protectors are also disclosed which are configured to temporarily and removably couple to the interior diameter of the rim. In one form all of these elements fit within a very small transportable container such as a bag. As motorcycle saddlebags are very small, space within them is at a premium so the smaller a kit may be preferred.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a tire and wheel combination;
FIG. 2 is a cross-sectional view of a tire and wheel as taken along line 2 of FIG. 1 ;
FIG. 3 is a side view of the assembly;
FIG. 4 is a side view of the assembly and operation;
FIG. 4A is a detailed view of FIG. 4 ;
FIG. 5 is a view of the tire and wheel assembly with components in place to remove the tire from the wheel;
FIG. 6 is a detailed view of a tire iron;
FIG. 7 is a detailed view of the base elbow;
FIG. 8 is a detailed view of the driving member;
FIG. 9 is a detailed view of the plunger member;
FIG. 10 is a detailed view of the lock bar;
FIG. 11 is a detailed view of a plurality of release pins and connecting lanyard;
FIG. 12 is a detailed view of the foot and scratch guards connected by a lanyard;
FIG. 13 is a detailed view of the rim protectors;
FIG. 14 is a detailed view of the valve stem multi-tool;
FIG. 15 is a view of a bottle for containment of releasing chemicals; and
FIG. 16 is an exploded view of the kit containing the entire apparatus in its component parts for storage or transportation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
To aid in the discussion of this disclosure, an axis system 10 is disclosed wherein the radially outward direction 12 defines that direction from the center of the wheel apparatus towards the tire 3 perimeter. FIG. 2 shows the axis system 10 including a vertical direction 14 . Each of these is applicable to a tire assembly lying flat on its side, as it would be configured to operate on the tire or to remove the tire from the rim.
To further aid in the understanding of the disclosure, a prior art example of a motorcycle wheel assembly is disclosed comprising a tire 3 often made of rubber, a rim 4 often made of metal and often comprising spokes. The wheel 6 comprises the hub 8 or center portion of the assembly and the rim 4 . The hub 8 and a rim 4 are often connected by spokes but may also be coupled by unitary structure. FIG. 2 is a prior art example of a tire 3 and wheel 6 taken along line 2 of FIG. 1 .
In general, the assembly 20 as first shown in FIG. 3 comprises a plurality of elements: a leverage tire iron 22 , a driving member 24 , a support tire iron 26 , a base elbow 28 , and a base tire iron 30 . The leveraged tire iron 22 has a first end 32 a and a second end 34 as shown in FIG. 6 . The second end 34 is adaptively configured to fit within a portion of the driving member 24 . This is accomplished by way of a channel 36 being disposed in the driving member 24 as shown in FIG. 8 . The leveraged tire iron 22 is maintained within the channel 36 of the driving member 24 by way of a pin 38 . In one form, the assembly 20 utilizes as many as five of these pins 38 . For ease of construction and assembly, each of the pins 38 may be made identically. To continue the discourse on the assembly 20 , the driving member 24 has a first end 40 configured to interoperate with the leveraged tire iron 22 and a second end 42 . The driving number 24 furthermore has a middle region 44 . The middle region 44 has a channel 36 including an open region 46 further comprising a plurality of holes 48 . This channel 36 is configured to accept a plunger 50 . As shown in FIG. 9 , the plunger 50 comprises a first end 52 , a plurality of holes 54 , and a tab 56 . The tab 56 may be formed as a unitary structure with the plunger 50 , or may be attached by other means such as a weld 58 . The holes 54 in the plunger member 50 are configured to accept with a pin 60 which is furthermore fit within with the holes 48 of the driving number 24 . This particular assembly allows the plunger 52 to rotate about a pivot point 62 comprised of the pin 60 and the holes 48 and 54 . The plunger 50 is configured such that it may also be used as a fourth tire iron by virtue of the design of end 52 . The particular advantages of this assembly will be discussed later.
The support tire iron 26 as detailed in FIG. 6 comprises a first end 32 b , and a second end 34 b . The support tire iron 26 further comprises a pivot point 64 being a hole similar to those previously discussed. A pin 66 is disposed through a hole in the second end 42 of the driving member 24 and a hole near the first end 32 b of the support tire iron 26 forming the pivot point 64 . This allows the driving member 24 to rotate substantially about the support tire iron 26 . The advantages therewith will be discussed later.
The assembly 20 furthermore comprises a base elbow 28 which has a first end 68 , an angle region 70 , and a second end 72 . Furthermore the base elbow 28 comprises a plurality of holes 74 . There are also holes 76 disposed in the second end 72 of the base elbow 28 . The base elbow 28 is further detailed in FIG. 7 . The base elbow 28 further comprises a back surface 78 and a front surface 80 . Furthermore a top surface 82 and a bottom surface 84 are disposed between the first side 86 and a second side 88 of the base elbow 28 . These surfaces of the base elbow 28 comprise a channel 90 . This channel 90 is configured to accept a plurality of tire irons. The support tire iron 26 is configured to be slideably positioned within the first end 68 of the base elbow 28 . In this embodiment it is held in position by the first side 86 , the second side 88 , the front surface 80 , and the back surface 78 . A plurality of holes 74 are disposed in the first side 86 and second side 88 . As seen in FIG. 3 , a pin 92 is placed through these holes and holds the support tire iron 26 in place. As a plurality of holes 74 are disposed in the base elbow 28 , the vertical position of the support tire 26 can be adjusted which furthermore adjusts the vertical position of the driving member 24 , increasing the distance between the tab 56 of the plunger 50 and the second end 72 of the base elbow. This is very useful when tires of varying widths are used by the apparatus. Having a wide range of applicability is very useful as not all tires are the same. A pin 94 is configured to interoperate with the hole 76 of the second end 72 of the base elbow 28 . This operates similarly to the above-mentioned pin 92 configuration however the second end 72 of the base elbow 28 is configured to interoperate with the base tire iron 96 .
To protect the apparatus and the interior portion of the wheel 6 a plurality of scratch guards 97 and 98 are disclosed. These are shown first in FIG. 3 , and detailed in FIG. 12 . The scratch guards 97 and 96 comprise a top surface 100 , a body 102 and a bottom surface 104 . A dado or channel 106 is disposed in the top surface 100 and configured to interoperate with the base elbow 28 . These scratch guards 97 and 98 may be formed of a malleable material such as plywood or polymer such that they will absorb impact and abrasion between the wheels 6 and the base elbow 28 . The rubber bands which can also be supplied with the kit can be wrapped around the base elbow and the scratch guards 97 to maintain their position upon the base elbow 28 . As shown, the scratch guards 97 and 98 may further comprise a plurality of staples 108 which are configured to couple to a lanyard 110 . In one form, the lanyard 110 is configured to couple to a foot 112 .
The foot 112 has a base 114 and an angle portion 116 . The base 114 further comprises a top surface 117 and a bottom surface 118 . The bottom surface 118 is configured to interoperate with the top surface 120 of the angle portion 116 . The top surface 120 is disposed on the horizontal portion 122 of the angle portion 116 . The angle portion 116 furthermore has a vertical portion 124 which in form has a channel 126 disposed therein and configured to interoperate with the base tire iron 96 . This foot 112 operates for two advantages, the first being that it prohibits the assembly 20 from rotating about base elbow 28 when it is in its upright position as shown in FIGS. 3 and 4 . The foot 112 has the added advantage of providing a wider base for the assembly 20 such that when forces applied to the leverage tire iron 22 at force vector 28 of FIG. 4 , the foot 112 resists any motion in the downward direction which would tend to push it into the ground if the ground is not of sufficient rigidity to support the assembly 20 without the foot 112 . For example by putting significant force on the leverage tire iron 22 when the assembly 20 is set on a sandy ground level, the assembly would tend to dig into the ground and be difficult to use. The lanyard 110 which in one form connects the scratch guards 97 and 98 to the foot 112 may be so configured to attach via a hole 131 disposed in one end of the foot 112 .
A stop member 130 comprising a first end 132 and a second end 134 is configured to interoperate with the base tire iron 96 . This is shown in FIGS. 3 and 4 , and detailed in FIG. 10 . The stop member 130 further comprises a slot 136 configured to accept the base tire iron 96 and be of sufficient size to allow the stop member 130 to slide substantially along the base tire iron 96 . The stop member 130 further comprises a front surface 138 which is configured to interoperate with the tire 3 . This can easily be seen in FIG. 3 wherein the stop member 130 is configured along the base tire iron 96 and is in contact with the tire 3 . In this position the stop member 130 maintains the position of the tire 3 and wheels 6 in relation to the apparatus 20 when force is applied along force vector 28 to the leverage tire iron 22 . Enabling the stop member 130 to be positioned along the base tire iron 96 allows for a wide range of tire sizes. The stop member 130 may also be utilized as a 5 th tire iron by virtue of it's size and design as the end 132 is similar to the profile of an end of the tire iron 144 .
To make the entire assembly and associated elements easy to carry, a kit 132 is disclosed comprising the elements previously discussed and furthermore including a bag 135 configured to hold all of the items when they are in their disassembled state. This is shown in FIG. 16 . Furthermore a multi-tool 134 as detailed in FIG. 14 may be included comprising a connective region 136 coupling on a first end 138 an air deflating head 140 and a valve core removal head 143 . On the second end of the multi-tool 134 is a valve stem puller head 143 . The deflating head 140 is used to deflate the tire in that it contains a core portion engaged to interoperate with a valve stem on a traditional tire and operates to release the pressure therein. The core removal head 143 is configured to move the valve portion from the valve stem of the tire for ease in removing the tire 3 from the rim 4 or alternatively to replace it if it becomes defective. The stem-puller head is provided to help a user pull a new valve stem into position on a wheel.
Additionally a plurality of rim protectors 142 are disclosed which are configured to be positioned on the rim 4 to protect the rim 4 from damage when the tire 3 is removed from the rim 4 after the bead has been broken. As shown in FIG. 5 , the rim protector 142 is placed between the tire iron 144 and the rim 4 . The tire iron can then be rotated about the rim protector 142 removing the tire 3 from the rim 4 in at least one position, the tire iron 144 is then rotated about the rim 4 as common in the art and the tire is removed from the rim.
The kit 132 may also comprise a chemical 146 which aids in keeping the tire from re-adhering to the rim after the bead has been broken. One such chemical is Bead Goop™. These chemicals 146 are common in the art and therefore will not be discussed further in this disclosure.
In one form, the kit 132 comprising all the elements previously discussed may be contained within a bag 135 . This bag 135 may optionally be tied shut using strings 148 and thus provide a compact kit which can easily be fit in to storage such as the saddle bags of a motorcycle. In one form the entire apparatus when the bag is tied shut takes up a space of approximately twelve inches in length, six inches in width, and three inches in height. Instructions may be provided within, or printed upon the bag or any tool element. Of course the size of the apparatus depends entirely upon the tools contained within.
To describe how the apparatus is used, it must be understood that oftentimes, the radially inward annular region of the tire 150 as detailed in FIG. 4A is in tight or even adhesive engagement with the inward annular region of the rim 152 . Therefore, a focused amount of force is required at point 154 by the plunger 50 to “break the bead” on a pneumatic motorcycle tire assembly. This forms a gap 156 between the inward annular region of the tire 150 and the inward annular region of the rim 152 . Once this is accomplished, it is a simple matter to either reposition the assembly 20 to a new position and further increase the gap 156 , or as known in the art you may “walk the rim” for any person literally stands upon the tire portion and breaks the bead around the tire and wheel assembly. It may be advantageous to use the chemical 146 to assist in breaking the bead. As shown in FIG. 15 a chemical is disclosed being contained within a bottle 158 having an optional flip top 160 . This first step of “breaking the bead” is often times the most difficult part of this process and therefore the assembly as disclosed is of great benefit to those wishing to repair their motorcycles in the field. Referring to FIG. 4 , it can be appreciated that the articulating portion of the assembly is repositioned with respect to the base tire iron 96 where the articulating portion operates in one form as a first-degree lever where pressure can be applied at point 154 shown in FIG. 4 a . This is accomplished by applying force along the line of force vector 28 . Further, because the driving member 24 generally follows a circular motion about the pivot location 64 , the longitudinal location of the pin 60 varies with respect to the degree of rotation. Therefore, in one form, the plunger adjustment system is comprised of a transverse pivot pin 60 which also allows the vertical adjustment of the plunger by way of the holes 54 .
As is detailed in FIG. 9 , the plunger 50 has a welded or formed tab 56 which is shaped and formed to minimize damage to the side wall of the tire 3 . The tab 56 is shaped such that when pressure is applied to the leverage arm, the plunger is forced against the tire 3 forcing it away from the rim 4 . This is accomplished in two directions such that the tab 56 moves away from the rim 4 which will assist in keeping the tab 56 from damaging the rim 4 while it is simultaneously pressing the tire down and away from the rim. Such damage is very undesirable as it could cause the tire to fail in its operation of maintaining air within.
The assembly 20 is configured to be capable of disassembling into component parts which can then be carried easily by a motorcycle driver. The components of the bead breaker assembly could include a group of tire irons usually combination of three tire irons. The three tire irons each have a first end, a second end, and a middle portion. A driving member is also disclosed having a central chamber region, a first end, a middle portion, and a second end. Transverse holes are disposed in the first end, middle portion and the second end and configured to accept a pin. The first end of the driving member is configured to accept the end portion of the leverage tire iron in such a way as to form an extension of the driving member. In one form, a pin is then passed through the transverse holes of the driving member and the leverage tire iron fixing it in place. Similar attachment methods can be utilized, such as a press-fit, magnetic coupling, ball and socket, and the like. A plunger member is also disclosed having a first end, a middle portion, and a second end. A plurality of transverse holes are provided in the middle section of the plunger member and configured to accept a pin. The holes in the middle portion of the plunger member are configured to align with transverse holes in the middle portion of the driving member thus forming a pivot point. A tab portion is also disposed on the second end of the plunger member and configured to engage the tire portion of a tire/wheel assembly.
The second end of the driving member is configured with a plurality of transverse holes configured to accept a pin. Transverse holes in the second end of the driving member are configured to accept the pin which is also passed through transverse holes in the second end of the support tire iron forming a pivot point such that the driving member which is coupled to the leverage tire iron pivots about the pin in the support tire iron. A base elbow is also disclosed having a first end, a second end, and a middle or angled portion. The base elbow also comprises a substantially channel portion configured to accept the second end of the support tire iron. A pin is then positioned through holes in the second end of the support tire iron and the first end of the base elbow which prohibits vertical movement of the support tire iron in relation to the base elbow. The channel is configured in such a way that the support tire iron is prohibited from rotating about the pin. The angled portion form substantially a 90° angle between the first end of the base elbow and the second end of the base elbow. The second end of the base elbow is configured to accept the end portion of the base tire iron and fix it in place as described with the support tire iron. It may be desired that each of the pins previously discussed are in the form of quick release pins which are common in the art.
As force applied to the leverage tire iron once the apparatus is assembled and in place may cause outward force from the base elbow, a lock bar is also disclosed configured to fixedly in positionably to engage the base tire iron. As such it can be slid up against the tire and forms a cam-like positioning member. This lock bar prohibits movement of the tire/wheel assembly outward away from the base elbow.
Also disclosed is a kit containing all of the elements previously discussed and many others which can be used to aid in repair or removal of a tire from a motorcycle in the field. Such a kit could contain the plurality of tire irons, the quick release pins, the plunger member, the base elbow, the driving member, a fluid such as bead goop (tm), a plurality of scratch guards. In addition a base member may also be provided which is configured to support the assembly while it is being assembled and while it is in use. Further included in the kit may be a valve stem multi-tool which is configured to remove the valve stem from the wheel and thus release air pressure therefrom. The valve stem multi-tool may have several different tools disposed thereon including a tool for releasing pressure from a tire, a tool to remove the valve stem from the tire, and a tool for reinserting a new valve stem then into the wheel or tire. A plurality of rim protectors may also be included in this kit as will be described later. As many as these parts are relatively small it may be desired to couple a plurality of these elements together by way of a lanyard. For example it may be beneficial to couple several of the pins together which enlarges their total size and aids in keeping them from being lost. It may optionally be desired to connect scratch guards by way of a lanyard to maintain their position on the base elbow and to keep them from getting misplaced. The tire iron 144 which in its independent forms may be the leverage tire iron 22 , the support tire iron 26 , or the base tire iron 96 . It may be identical in size and shape, but a variety of length may be selected at the option of the user. The tire iron 144 is constructed of a metal bar or other suitable material size as desired for use, but for this working model approximately point 25 inches thick, point 75 inches wide, and eight inches long. The first end 32 and second end 34 are tapered and formed as needed to facilitate the process of prying the rubber tire from the metal rim. Usually the first end 32 of the tire iron 144 will comprise a spoon-like bend, which is proven to assist in the tire removal process, and the second end 34 will be tapered and flattened.
Additionally, each tire iron 144 has a hole of sufficient size drilled or machined through the flat portion of each end, positioned and sized as required to provide for insertion of removable fixing pin as previously discussed. In one form, these holes are approximately 1 inch to 1.5 inches from the ends.
To assemble the assembly 20 in one form, a tire iron 144 is positioned into each end of the base elbow 28 , and a pin is placed in a hole selected by the user, so the end of each tire iron 144 is fixed within the ends of the base elbow. The base elbow is placed on a flat horizontal surface, preferably the ground or a workbench, with one tire iron 144 directed vertically upward, and one tire iron 144 resting on the work surface. The tire 3 and rim 4 assembly is placed down over the vertical tire iron so that the vertical tire iron penetrates the space between the spokes, in the open area between the metal rim 4 and the axial hob 8 . The tire and rim assembly will rest horizontally on the work surface. The base tire iron 96 should project outward from the hub 8 and should pass underneath the rim 4 and tire 3 . The weight of the rim 4 and tire 3 assembly will rest upon the base elbow 28 . The tire assembly and base elbow can be adjusted so that the support tire iron 26 is in close proximity to the inner edge of the rim 4 . A leverage tire iron 22 is inserted into the channel 36 of the driving member 24 so that the leverage tire iron 22 becomes an extension of the driving member 44 . A removable pin 38 is inserted as selected by the user, fixing the leverage tire iron in place within the channel 36 of the driving number 24 . The driving member 24 is held in a substantially horizontal position and the first end 52 of the plunger 50 is inserted upwardly into the channel 36 of the driving member 24 . The user selects an appropriate hole 54 and hole 48 , and inserts a pin 60 into the driving member 24 passing the pin through a hole 54 of the plunger 50 . This connection becomes a hinging point for the plunger 50 in relation to the driving member 24 . The tab 56 at the opposite end of the plunger 50 is pointing substantially downward.
The substantially parallel site extensions 158 and 160 of the driving member 24 are then positioned over the support tire iron 26 that is projection substantially vertically between the spokes of the tire assembly. A pin 66 is positioned through the holes 62 and 64 of these side extensions 160 and 158 , and simultaneously through the hole at the end of the end of the support tire iron 26 . The assembly of the bead braking device in one form is now complete.
The user can then adjust the various components relative to one another, such that each component achieves the best leverage and in addition the wedge-shaped tab 56 of the plunger 50 makes contact with the pneumatic tire, at the point 154 where the tire and rim meet. Once all adjustments are complete, the user may exert force upon the leverage tire iron 22 along force vector 28 thus compressing the tire 3 . Due to the particular configuration of the plunger and tab 56 , it will also tend to move the plunger 50 inward away from the rim 4 which is desirable for the purpose of breaking the bead. The more force the user exerts upon the leverage tire iron 22 , the more the side wall and bead are pushed downward and out of contact with the metal rim 4 . At some point the “bead will break” meaning that the adhesive or friction seal between the tire 3 and rim 4 will give way. The user can then reposition the assembly 20 to an adjacent position and repeat the process as needed until the entire side wall has broken contact from the rim. The user can then turn the entire assembly over, and repeat the bead breaking process on the other side of the tire assembly. Once the tire bead has been broken from both sides of the tire assembly, the rubber tire 3 and inner tube (if present) can be removed for repair or replacement. The user may then remove the appropriate pins from the assembly, freeing the assembly from its role and structural members of the bead breaking device releasing the tire irons 144 . The user may then employ the tire irons 144 as needed in the process of removing the tire 3 from the rim 4 . If the assembly is used in field conditions where a relatively hard work surface is not available, the assembly may be positioned on two or more plywood, wooden, or metal slats. One form of these slats is the foot 112 .
Once the tire 3 has been removed from the rim 4 , it is usually a simple matter to repair or replace the tire 3 and then reposition the repaired tire 3 upon the rim 4 and re-inflate the tire 3 to correct the damage that was initially caused. The wheel assembly may then be replaced on the motorcycle or vehicle and the user can go on their way.
While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants' general concept. | A portable tire bead breaker comprising a plurality of elements which can be disassembled to form a compact kit. Includes a base over which a tire and rim may be placed, a support member, and a lever arm. Also included is a plunger member configured to engage the tire and break the bead thereon. To break a tire bead, the elements are assembled and a force is extended upon the lever arm, engaging the plunger member upon the tire and creating sufficient force against the tire in opposition to the rim to disassociate therefrom. The tire bead breaker can be disassembled into a compact unit for storage and transportation. | 1 |
This application is a continuation of application Ser. No. 08/435,583, filed May 5, 1995 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a door locking mechanism, and in particular to a mechanism for activating a plurality of locking bolts in high security devices such as safes.
When securing a safe or other security enclosure, it is important to ensure that each possible method for opening the safe is guarded against unauthorized entry. In attempts to accomplish this, numerous different methods have been developed for ensuring that the door of the safe may not be easily opened, as the door is often the most vulnerable portion of the safe. If a burglar, etc., is able to pry the door of the safe open, the structural integrity of the remainder of the safe becomes irrelevant. In attempts to overcome this concern, numerous arrangements have been made which cause a plurality of locking bolts to extend from either side of the door and into the remainder of the safe so as to prevent the door from being opened by prying or other force.
While the use of locking bolts improves the security of the door, the present arrangements for engaging the locking bolts provide insufficient protection, are difficult to use, or are overly expensive. Other systems provide adequate protection, but are needlessly complex and have numerous moving parts. If the parts fail, the owner of the safe may be unable to retrieve his or her belongings without unnecessary delay, and the possibility of destroying the safe.
Thus, there is needed a simple, efficient and cost effective method to engage locking bolts on a safe door. Such a method would minimize the number of moving parts while providing secure protection against the door of the safe being opened without authorization.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the invention to provide a door locking mechanism for safes and the like which is inexpensive and simple to use.
It is another object of the present invention to provide a door locking mechanism for safes and the like which securely holds the safe door so as to prevent unauthorized entry.
It is another object of the present invention to provide a door locking mechanism with a minimum number of moving parts so as to decrease the risk of failure of the door locking mechanism.
It is yet another object of the present invention to provide a door locking mechanism in which the moving parts of the mechanism can be installed on a door without welding, and in which the parts are interchangeable.
The above and other objects of the invention are realized in specific illustrated embodiments of a door locking mechanism for safes and the like including a door lock in communication with a lock-actuated bolt which selectively allows rotation of an actuator plate member. The rotating actuator plate member is rotated by a handle, and when rotated, moves a plurality of actuator bars. Movement of the actuator bars moves a plurality of locking bolts disposed along a perimeter of the safe door so as to prevent the door from being pried open.
In accordance with one aspect of the invention, at least one of the actuator bars connected to the rotatable actuator plate member extends to an upper and lower end of the door and also serves as a locking bolt to engage a frame of the safe and provide resistance to opening along a central portion of the door.
In accordance with another aspect of the invention, the locking bolts are removably and adjustably connected to the actuator bars to facilitate attachment of the locking mechanism to the door without welding, provide the ability to adjust the locking mechanism once it is attached to the door, and to make respective parts interchangeable.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description presented in connection with the accompanying drawings in which:
FIG. 1 shows a rear view of a safe door having a door locking mechanism made in accordance with the principles of the present invention mounted on the door;
FIG. 1A shows a close-up, fragmented view of a preferred embodiment of the locking pins of the present invention.
FIG. 2 shows a close-up, fragmented view of the door locking mechanism of the present invention;
FIG. 3 shows a side view of the door shown in FIG. 1, so as to reveal the mechanisms for engaging and disengaging the door locking mechanism of the present invention, and a fragmented cross-sectional view of a safe body positioned about the door; and
FIGS. 4A and 4B show fragmented close-up views of a portion of the locking mechanism including attachment mechanisms for connecting the actuator bars and the locking bolts.
DETAILED DESCRIPTION
Reference will now be made to the drawings in which the various elements of the present invention will be given numeral designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. Referring to FIGS. 1, 1A and 2, FIG. 1 shows a rear view of a safe door, generally indicated at 10, having a locking mechanism, generally indicated at 14 disposed thereon. FIG. 2 shows a close-up view of the locking mechanism 14. The safe door 10 has a generally flat face 18 and a frame 22 extending rearwardly from the face such that the frame extends into the area defined by the safe when the door 10 is closed.
Typically, the door face 18 will be steel between 0.25 and 0.75 inches thick. Obviously, thicker door faces 18 are used to provide additional security for the contents of the safe. The door frame 22 will typically be an angle frame having dimensions about 0.375 inches by 1.5 inches by 2.5 inches.
Extending through the lateral sides of the door frame 22 are a plurality of locking bolts 26. The locking bolts 26 are typically short pieces of cylindrical steel, although other shapes may be used, and will have a diameter of about 0.5 to 1.25 inches depending on the desired security level of the safe. The locking bolts 26 along each lateral side of the frame 22 are attached to a locking bar 30. Moving the locking bars 30 from a first position away from the frame 22 to a second position adjacent the frame 22, causes a change in the distance which the locking bolts 26 extend beyond the frame. When the locking bars 30 are moved away from the frame 22, the locking bolts 26 are pulled toward a center of the door, and only a small portion of the locking bolt extends beyond the frame. In such a position, the locking bolts 26 will not engage a lip of the frame body (discussed with respect to FIG. 3).
The locking bars 30 are moved between the first and second positions by a pair of elongate actuator bars 40 which extend inwardly and generally horizontally. Each of the actuator bars is attached to a locking bar 30 at a distal end 44 and to a rotatable actuator plate 48 at a midsection 50 between the distal end and a proximal end 52. The attachment between the distal end 44 of the actuator bar 40 and the locking bar 30 will typically be an adjustable attachment such as the nut and bolt attachment shown in FIGS. 4A and 4B. At the midsection 50 the actuator bars 40 are attached to the rotatable actuator plate 48 by pivotal or rotatable attachment tabs 54. The rotatable attachment tabs 54 enable the actuator bars 40 to be moved horizontally by the actuator plate 48 as the actuator plate rotates. Guides 58 help to maintain the horizontal orientation of the bars 40. When the actuator plate 48 rotates in a clockwise direction, the locking bars 30 are moved from the first, open position to a second, locking position in which the locking bolts 26 are extended to a maximum extension through the frame 22. When the safe door 10 is closed and the locking bolts 26 are in this extended position, the door 10 cannot be opened without first moving the locking bolts.
The rotatable actuator plate 48 is attached to a handle mechanism (discussed with respect to FIG. 3) by a shaft 56. Rotation of the shaft 56 causes rotation of the actuator plate 48 in the same direction.
The rotatable actuator plate 48 is also connected to two elongate locking pins 60, one of which 62 extends from the rotatable actuator plate to a top side 66 of the door, and the other of which 64 extends to a bottom side 68 of the door. The locking pins 60 may serve the functions of both the actuator bar and the locking bolts. The pins 60 are pivotally attached to the rotatable actuator plate 48 by attachment mechanisms 72. The pins 60 (or a bolt attached thereto) extend to the frame in a similar manner as the actuator bars 40 and through the frame 22 in the same manner as the locking bolts. Thus, the pins may be both actuator bars and locking bolts. The actuator pins 60 provide support in the top and bottom of door 10 along the vertical center line so that the door cannot be buckled outwardly sufficient to overcome the locking effect of the locking bolts 26.
In a preferred embodiment, the locking pins have bolts disposed on an end thereof. Each of the locking pins 60 has an ending with male threads 69 which mates with female threads in a threaded locking bolt 71 as shown in FIG. 1A. An adjustment/locking nut 73 and washer 75 are also provided to allow locking the bolt 71 in various vertical/height positions as needed, e.g., to maintain the locking bolt generally flush with the surface of the frame 22 when retracted. Alternatively, shoulder 74 on the bolt 71 could be crimped by a crimping tool, after the locking pin 60 was screwed into the bolt 71.
While each of the actuator bars 40 and the locking pins 60 could be attached directly to the rotatable actuator plate 48, it is preferred that they be attached by small tabs 54 and 72, respectively, extending from the actuator bars 40 and locking pins 60 respectively. The tabs may also be slotted, as shown with the rotatable attachment tabs 54 of actuator bars 40 in FIG. 2, to facilitate smooth rotation. The slots help to maintain the actuator bars at the same vertical position as the actuator bars move back and forth.
Positioned above the rotatable actuator plate 48 is a locking member 84 which enables or disenables rotation of the actuator plate. A retractable lock-actuated bolt 88 extends downwardly from the locking member 84 so as to nest in a channel 92 formed in the rotatable actuator plate 48 when the locking member is turned to lock. When the locking member 84 is unlocked, the lock-actuated bolt 88 is lifted from the channel 92 so that the rotatable actuator plate 48 can be turned. Those skilled in the art will recognize numerous locking arrangements which could be used in the locking member 84 while still keeping within the scope and spirit of the invention.
Also illustrated in FIGS. 1 and 2 is a dual lock system to prevent the safe from being unlocked by a force which displaces the locking member 84 from the door face 18. One common method used to force open a safe is to cut an opening in the door face 18 at the location of the locking member 84. A tool is then pushed into the hole and hammered against the locking member 84 until the locking member is dislodged from the door face 18. With many safes, once the locking member 84 is moved, the safe may be freely opened by simply rotating the handle.
In the dual lock system shown in FIGS. 1 and 2, a safety locking bolt 96 is positioned above a notch 100 formed in the rotatable actuator plate 48. The safety locking bolt 96 is held in a raised (nonlocking) position by spring pin 120 which nests at least partially in the bolt. The spring pin 120 is held in a cocked position by plate 104 (shown by a dotted line in FIG. 2).
The safety bolt 96 is oriented in a generally vertical position by guides 108 and 112 which will typically be attached to the door face 18. The bolt 96 passes through openings in the guides 108 and 112.
A spring 116 is attached to the bolt 96 at one end and butts against the upper guide 108 at the other end. The spring 110 is held in a compressed state by a spring pin 120 which is removably attached to a midsection of the bolt 96. The lower guide 112 is positioned low enough that it will not interfere with extension of the spring 116 and the bolt 96 contacting the notch 100 in the rotating actuator plate.
When unauthorized entry to the safe is attempted in the manner described above, the force applied to the locking member 84 to dislodge it from the door 18 will cause the plate 104 to be dislodged, thereby dislodging the spring pin 120 from the safety locking bolt 96. Once the spring pin 120 is released, the bolt 96 is able to move. Thus, the spring 116 will act on the bolt 96 and force a lower end 124 of the bolt 96 down into the notch 100 in the rotatable actuator plate 48, thereby preventing rotation of the actuator plate even if the locking member 84 has been dislodged.
The safety locking bolt 96, of course could be actuated by gravity without a spring bias. A spring bias, however, is generally preferred inasmuch as the dual lock mechanism will then work regardless of the orientation of the safe, i.e., the safe can be upside down and the dual lock mechanism will effectively operate.
Referring now to FIG. 3, there is shown a side view of the door 10 and frame 22 discussed in FIG. 1, and a fragmented cross-sectional view of the safe body 130. The safe body 130 has a lip 134 which extends around an opening into which the door 10 fits. When locked, the locking bolts 26 and the locking pins 62 and 64 slide behind the lip 134 to prevent the door 10 from being opened.
When the locking member 84 is in an unlocked position, the locking bolts 26 and the locking pins 62 and 64 can be moved between first and second positions by rotating a handle 140 on a side of the door opposite the frame 22. When the handle 140 is rotated so that the rotating actuator plate 48 (FIGS. 1 and 2) rotates clockwise, the locking bolts 26 and locking pins 62 and 64, move behind the lip 134 to prevent opening of the door. When the handle 140 is rotated counter-clockwise, the locking bolts 26 and locking pins 62 and 64, retract through the frame 22 and allow the door to be opened.
Referring now to FIGS. 4A and 4B, there are shown close-up views of attachment mechanisms for connecting the locking bars 30 to the actuator bars 40 and to the locking bolts 26. The actuator bar 40 has a plate 150 extending transversely therefrom. The plate 150 has a pair of slots 154 formed therein for receiving a bolt 158. Likewise, the locking bar 30 has a pair of channels 162 which are generally transverse to the slots 154. When the slots 154 and the channels 162 are placed in an overlapping arrangement so that the bolts 158 may extend therethrough, an adjustable attachment mechanism is provided which enables horizontal and vertical adjustment of the position of the locking bar 30. This allows the actuator bar 40 to be attached to the locking bar 30 in situ without the need for welding. As will be appreciated by those skilled in the art, such an arrangement is less time consuming and enables the fine-tuning of the locking mechanism on the door before the bolts are tightened.
Additionally, the single actuator bar 40 connected by plate 150 to the locking bar 30 enables orientation between the locking bar and actuator bar to be adjusted vertically, horizontally and angularly, which is not the case with the prior art mechanisms in which the actuator bar equivalent is generally welded to the locking bar equivalent. Thus, if the holes in the frame (FIG. 1) are not formed in the proper position, the elongate bar 30 may be adjusted so that the locking bolts 26 better align with the holes.
Also shown in FIG. 4A are the locking bolts 26 which are attached to the locking bars 30 by bolts 170. As with the attachment mechanism for the actuator bars 40 and the locking bars 30, the bolts 170 enable fine adjustments in the position of the locking bolts 26, i.e. the distance which they extend through the frame, and thereby enable the locking mechanism to be fine-tuned on site. Of course, the locking bolts 26 could also be riveted to the locking bars 30.
Thus there is disclosed a door locking mechanism for safes. The mechanism provides a simple and effective way to prevent unauthorized entry into a safe, while minimizing the number of parts which may fail and prevent access to the contents of the safe. Additionally, the mechanism enables assembly and adjustment of some of the components of the locking mechanism on site, and without welding. Those skilled in the art will recognize numerous modifications which may be made while remaining within the scope and spirit of the invention. The appended claims are intended to cover such modifications. | A door locking mechanism is disclosed including a door locking member in communication with a lock-actuated bolt which selectively allows rotation of a rotatable actuator plate member. The rotating actuator plate member is attached to a rotatable handle and to a plurality of actuator bars which move locking bolts so as to selectively prevent opening of the door. The rotatable actuator plate member enables all of the actuators to be moved from a single location so that a plurality of cams, etc., are not needed to move locking bolts positioned about the perimeter of the door between open and locking positions. In an additional aspect of the invention, horizontally extending actuator bars are adjustably attached to elongate locking bars having a plurality of locking bolts attached thereto, so as to enable assembly of the locking structures of the door locking mechanism without assembly, and to enable interchangeability of parts. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improved process for producing alkoxy-substituted triphenylamines.
The alkoxy-substituted triphenylamines obtained by the process of the present invention are useful compounds as an intermediate for use in general chemical industries, particularly as an intermediate for dyes, agricultural chemicals, rubber chemicals and the like.
2. Description of the Related Art
It has hitherto been known to prepare triphenylamines by reacting cyclohexanones with diphenylamines, while forming the cyclohexanones in the same system from phenols used as the hydrogen acceptor in the presence of a hydrogen transfer catalyst (Japanese Patent Laid-Open No. 183250/1986). The reference describes that triphenylamine is obtained in an yield of 68.5% (selectivity: 85.1%) by reacting diphenylamine with cyclohexanone in an excess amount of phenol in the presence of a palladium catalyst.
However, when the present inventors traced the above-described process by using an alkoxy-substituted cyclohexanone and an alkoxy-substituted phenol as raw materials, they found that a triphenylamine with the alkoxy substituent eliminated was by-produced in a considerable amount, but an alkoxy-substituted triphenylamine, the desired product, could not be obtained in a satisfactorily high yield.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a highly efficient process for producing an alkoxy-substituted triphenylamine in a high yield from an alkoxy-substituted phenol and a diphenylamine or an aniline.
The present inventors have made an examination to establish a more industrially advantageous process for producing alkoxy-substituted triphenylamines. In the course of the examination, it was found that in the process of reacting an alkoxy-substituted cyclohexanone with a diphenylamine or an aniline, while forming the cyclohexanone in the same system from an alkoxy-substituted phenol by using the phenol as a hydrogen acceptor, in the presence of a hydrogen transfer catalyst and a catalytic amount of the alkoxy-substituted cyclohexanone corresponding to the alkoxy-substituted phenol used for the reaction, or in the process of converting an alkoxy-substituted phenol to a catalytic amount of the corresponding alkoxy-substituted cyclohexanone under a hydrogen pressure and continuously reacting the alkoxy-substituted cyclohexanone with a diphenylamine or an aniline, while forming the cyclohexanone in the same system from the remaining alkoxy-substituted phenol by using the phenol as a hydrogen acceptor, in the absence of the catalytic amount of the alkoxy-substituted cyclohexanone in the beginning but in the presence of a hydrogen transfer catalyst, a decomposition reaction, i.e., a dealkoxylation proceeded so that the yield of an alkoxy-substituted triphenylamine, the desired product, was reduced. Further, it was surprisingly found that a surface-supported catalyst controlled the dealkoxylation and was significantly effective also as the hydrogen transfer catalyst, and when the surface-supported catalyst was used as the hydrogen transfer catalyst in the above reaction, alkoxy-substituted triphenylamines, the desired products, could be obtained in high yields. The present invention has been completed on the basis of these findings.
Specifically, the present invention provides a process for producing an alkoxy-substituted triphenylamine comprising reacting an alkoxy-substituted cyclohexanone with a diphenylamine or an aniline, while forming the cyclohexanone in the same system from an alkoxy-substituted phenol by using the phenol as a hydrogen acceptor, in the presence of a hydrogen transfer catalyst and a catalytic amount of the alkoxy-substituted cyclohexanone corresponding to the alkoxy-substituted phenol used for the reaction, wherein a surface-supported catalyst is used as the hydrogen transfer catalyst.
The present invention also provides a process for producing an alkoxy-substituted triphenylamine comprising converting partially an alkoxy-substituted phenol to the corresponding alkoxy-substituted cyclohexanone under hydrogen pressure and continuously reacting the alkoxy-substituted cyclohexanone with a diphenylamine or an aniline while forming the cyclohexanone in the same system from the remaining alkoxy-substituted phenol by using the phenol as a hydrogen acceptor, in the presence of a hydrogen transfer catalyst, wherein a surface-supported catalyst is used as the hydrogen transfer catalyst.
According to the process of the present invention, the dealkoxylation of raw materials and the intermediates can be controlled by using a surface-supported catalyst as the hydrogen transfer catalyst, and therefore desired alkoxy-substituted triphenylamines can be obtained in high yields.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail hereinbelow.
The alkoxy-substituted phenol used in the process of the present invention is a phenol having at least one alkoxy group and may have other substituent or substituents, such as alkyl group, phenyl group, phenoxy group, cyclohexyl group and fluorine atom, in addition to the alkoxy group or groups.
The alkoxy-substituted phenol may include, for example, 4-methoxyphenol, 2-methoxyphenol, 4-ethoxyphenol, 4-butoxyphenol, 4-nonyloxyphenol, 2,4-dimethoxyphenol, 3-methyl-4-methoxyphenol, 2-methoxy-4-phenylphenol, 3-methyl-4-butoxyphenol, 2-methoxy-4-phenoxyphenol, 2-methoxy-4-cyclohexylphenol and 2-fluoro-4-methoxyphenol. However, the alkoxy-substituted phenol is not limited to only those illustrated above.
Regarding the amount of the alkoxy-substituted phenol used in the process of the present invention, no problem will arise as long as it is equivalent or more to that of a diphenylamine where the corresponding alkoxy-substituted cyclohexanone is present from the beginning and the diphenylamine is used as a raw material. However, when the alkoxy-substituted phenol is used in excess also as a solvent, the selectivity to the triphenylamine tends to be increased. Therefore, it is preferable to use the alkoxy-substituted phenol in an amount of 1.5 to 20 times, preferably 2 to 10 times by mole of the diphenylamine. Where an aniline is used, no particular problem will be raised as long as the alkoxy-substituted phenol is used in two equivalents or more to the aniline. Also in this case, however, the selectivity tends to be increased by using the phenol in excess also as a solvent. Therefore, it is preferable to use the phenol in an amount of 3 to 20 times, preferably 4 to 10 times by mole of the aniline.
The alkoxy-substituted phenol used in the process of the present invention is a hydrogen acceptor and is also the source of supply for the alkoxy-substituted cyclohexanone formed as a result of the acceptance of hydrogen. Accordingly, the hydrogen by-produced during the reaction is used within the system. Further, the alkoxy-substituted phenol containing the alkoxy-substituted cyclohexanone which has been separated on removing the desired product of an alkoxy-substituted triphenylamine can be reused by recycling it to the reaction system as the mixture. Even when a suitable alkoxy-substituted cyclohexanone corresponding to the desired alkoxy-substituted triphenylamine is hardly obtainable, if the corresponding alkoxy-substituted phenol is available, the reaction may be effected by using an excess amount of the alkoxy-substituted phenol, reacting hydrogen fed in advance with a part of the phenol to convert it into the corresponding cyclohexanone, and reacting concurrently or subsequently the cyclohexanone with a diphenylamine or an aniline. Thus, the process of the present invention has a number of merits including a wide scope of applications.
As the alkoxy-substituted cyclohexanone, there are used alkoxy-substituted cyclohexanones corresponding to the above-described alkoxy-substituted phenols. They may include, for example, 4-methoxycyclohexanone, 2-methoxycyclohexanone, 4-ethoxycyclohexanone, 4-butoxycyclohexanone, 4-nonyloxycyclohexanone, 2,4-dimethoxycyclohexanone, 3-methyl 4-methoxycyclohexanone, 2-methoxy-4-phenylcyclohexanone, 3-methyl-4-butoxycyclohexanone, 2-methoxy-4-phenoxycyclohexanone, 2-methoxy-4-cyclohexylcyclohexanone, and 2-fluoro-4-methoxycyclohexanone. However, the alkoxy-substituted cyclohexanone is not limited to only those described above, as is the case with the alkoxy-substituted phenol.
The amount of the alkoxy-substituted cyclohexanone to be used is a catalytic amount of 0.03 mole or more for each mole of a diphenylamine where the diphenylamine is used as a raw material. Where an aniline is used, there is no particular problem as long as the amount is a catalytic amount of 0.03 mole or more for each mole of the aniline. It is however preferable to use the cyclohexanone in an amount of 0.05 to 0.60 mole for each mole of the diphenylamine and 0.05 to 1.00 mole for each mole of the aniline.
The diphenylamine used as a raw material in the process of the present invention may be any diphenylamine known in the art. It may be unsubstituted or substituted by an alkyl group, alkoxy group, phenyl group, phenoxy group, cyclohexyl group, carboxyl group, hydroxyl group, fluorine atom and the like. For example, it may include diphenylamine, diphenylamines whose nuclei are substituted by one or more alkyl groups, such as 2-methyldiphenylamine, 3-methyldiphenylamine and 2,2'-dimethyldiphenylamine, similarly diphenylamines whose nuclei are substituted by one or more alkoxy groups, halogens, carboxyl groups or nitrile groups, and p-phenyldiphenylamine. Diphenylamines whose nuclei are substituted by different functional groups, such as 2-methyl-4-chlorodiphenylamine, may also be used.
The aniline used as a raw material in the process of the present invention may be any aniline known in the art. It may be unsubstituted or substituted by an alkyl group, alkoxy group, phenyl group, phenoxy group, cyclohexyl group, carboxyl group, hydroxyl group, fluorine atom or the like. For example, it may include aniline, alkyl-substituted anilines such as 2-methylaniline, 3-methylaniline and 4-methylaniline, alkoxy-substituted anilines such as 4-methoxyaniline, carboxy-substituted anilines such as 4-carboxyaniline, and p-phenylaniline. Anilines whose nucleus is substituted by different functional groups, such as 2-methyl-4-chloroaniline, may also be used.
In the process of the present invention, it is important to use a surface-supported catalyst (egg shell type) as the hydrogen transfer catalyst. Specifically, it includes surface-supported catalysts carrying nickel, surface-supported catalysts carrying cobalt, surface-supported catalysts carrying copper, surface-supported catalysts which carry a metal of Group 8 in the Periodic Table, surface-supported catalysts carrying rhenium and the like. Among those, surface-supported palladium catalysts are preferred. Particularly, catalysts having palladium supported on the surface of a carrier, such as surface-supported palladium-carbon, surface-supported palladium-silica, surface-supported palladium-alumina, surface-supported palladium-diatomaceous earth and surface-supported palladium-magnesia are preferred. Especially, surface-supported palladium-carbon catalysts are most preferred.
Then, the surface-supported catalyst is illustrated by reference to palladium-carbon (Pd/C). The conventional uniform-type Pd/C is prepared by impregnating completely carbon as a carrier with an aqueous solution of a water-soluble palladium compound. On the contrary, the surface-supported catalyst is obtained by drying a carrier completely, spraying on the carrier an aqueous solution of a water-soluble palladium compound such as palladium chloride and palladium acetate or adding dropwise an aqueous solution of the palladium compound while stirring the carrier moderately to impregnate only the surface layer of the carrier with the palladium compound, drying the resultant carrier, reducing the palladium compound with hydrazine, formalin or formic acid in a liquid phase or with hydrogen in a gas phase, washing the carrier with hot water, and drying the carrier. Thus, there can be obtained a palladium-carbon catalyst which carries palladium only in the surface layer thereof.
The use of the catalyst is effective in controlling the formation of by-products due to the elimination of alkoxy groups, leading to the accomplishment of a high selectivity to the desired product.
The reaction of the present invention is illustrated by the following reaction formulas where a methoxy-substituted phenol and aniline are used by way of example. ##STR1##
According to the examination by the present inventors, it has become apparent that the dealkoxylation reaction primarily proceeds not in the phase of compounds (b) and (d) and the starting material of 4-methoxyphenol, in which one or more alkoxy groups are bonded to one or more aromatic rings, but in the phase of compounds (a) and (c) and 4-methoxycyclohexanone, in which each alkoxy group is bonded to an aliphatic carbon. Since the dehydrogenation reaction in compounds (a) and (c) proceeds favorably by any catalyst of either the uniform-type or the surface-supported type, it is thought that the dehydrogenation reaction takes place in the surface section of the catalyst, while the dealkoxylation reaction occurs in the deep layer section thereof. After all, because of a high degree of freedom of the alkoxy groups bonded to the aliphatic carbons, it is possible that the alkoxy groups arrive at the bottom of pores of the catalyst, in other words, the deep layer section of the catalyst, as compounds (a) and (c) approach the catalyst. Therefore, it is thought that in the case of the uniform-type catalyst which carries palladium to the depth of the deep layer section of the carrier, the alkoxy groups having arrived at the deep layer section are subjected to dealkoxylation by the palladium carried, whereas in the case of the surface-supported catalyst which carries no palladium in the deep layer section of the carrier, the dealkoxylation reaction is controlled so that an alkoxy-substituted triphenylamine, the desired product, can be obtained with a high selectivity.
The amount of the catalyst used is generally 0.001 to 0.2 atomic gram, preferably 0.004 to 0.1 atomic gram in terms of its metallic atom based on a diphenylamine to be used as a raw material, or it is generally 0.001 to 0.2 atomic gram, preferably 0.004 to 0.1 atomic gram in terms of the metallic atom based on an aniline to be used as a raw material.
The surface-supported catalyst used in the present invention is a solid metal catalyst in which a metal is preferably supported on a carrier powder at a amount of about 0.5 to 10% by weight based on the carrier powder. The solid metal catalyst is an egg-shell type catalyst having at least 70% by weight of the metal supported within 2 μm from the surface of the carrier. More preferably, the catalyst has at least 80% by weight of the metal supported within 1 μm from the surface of the carrier. The metal supported state can be analyzed by use of EPMA (Electron Probe Micro-analyzer).
In the process of the present invention, it is preferable to recycle and reuse repeatedly and continuously the reaction liquid obtained by separating the desired product from the reaction mass having undergone the reaction, without separating the remaining alkoxy-substituted cyclohexanone from the reaction liquid. In this case, it is advantageous to use an excess amount of the alkoxy-substituted phenol also as a solvent. Although it is not necessary to use other reaction solvents, they may be used without any trouble, as a matter of course. The reaction temperature selected is generally in the range of 130° to 300° C., preferably in the range of 180° to 250° C. If the temperature is below the range, the reaction rate is small and a large number of by-products tend to be formed.
In the process of the present invention, a preferred embodiment of charging the raw materials into a reaction vessel is such that a catalyst and an alkoxy-substituted phenol are charged, stirred and heated in the vessel in advance, to which a diphenylamine or an aniline is added dropwise to cause the reaction.
It is advantageous to carry out the reaction while removing the water formed. Therefore, the water is suitably separated from the reaction mixture by an azeotropic distillation using a solvent such as benzene, toluene or xylene.
The produced alkoxy-substituted triphenylamine can be obtained by treating the mixture having undergone the reaction by a conventional procedure such as distillation, crystallization and extraction. For example, the reaction liquid having undergone the reaction is filtered to separate the catalyst. The catalyst thus recovered can be used again. Then, the filtrate is concentrated to recover, as a distillate, the excess amount of the alkoxy-substituted phenol and the alkoxy-substituted cyclohexanone involved therein, and the distillate is recycled to the reaction system as the mixture. The concentrated residue in the concentrator is further subjected to distillation, crystallization or the like to purify and separate the triphenylamine.
Now, the present invention will be described in detail with reference to the following examples, but the scope of the present invention should not be limited only to these examples.
EXAMPLE 1
In a round flask provided with a reflux condenser equipped with a separator, a thermometer and a stirrer were charged 1.23 g of a surface-supported 5% Pd/C (at least 80% by weight of the carried Pd was supported within 1 μm from the surface of active carbon: 50 wet %) manufactured by N. E. Chemcat Co., 62.07 g (0.5 mol) of p-methoxyphenol, 3.85 g (0.03 mol) of p-methoxycyclohexanone and 22.93 g (0.1 mol) of 4,4'-dimethoxydiphenylamine. While being stirred, the contents in the reactor were heated to 200° C. and reacted for 9 hours and further heated to 230° C. and reacted for 4 hours. The water thus formed was azeotropically distilled by the addition of toluene, condensed in the reflux condenser and then separated by the separator. Subsequently, the reaction liquid was cooled and the 5% Pd/C was separated by filtration from the liquid, reaction mixture. The filtrate was analyzed by means of gas chromatography. As a result, the conversion of the 4,4'-dimethoxydiphenylamine was found to be 99.2%, and the selectivity of 4,4',4"-trimethoxytriphenylamine was 91.5%. Further, the selectivity of its dealkoxylated compound, 4,4'-dimethoxytriphenylamine, was 5.4%.
EXAMPLES 2 to 6
The reaction was carried out in the same manner as in Example 1 using a variety of diphenylamines and phenols given in Table 1 and cyclohexanones corresponding to the phenols. The results are illustrated in Table 1.
TABLE 1______________________________________ Conversion SelectivityExample Diphenylamine Phenol (mol %) (mol %)______________________________________2 2-methyl- 4-methoxyphenol 93.2 82.4 diphenylamine3 diphenylamine 4-methoxyphenol 97.5 86.24 diphenylamine 2-methoxyphenol 88.6 83.55 ditolylamine 4-methoxyphenol 96.5 84.96 4-methoxy- 4-methoxyphenol 97.0 83.7 diphenylamine______________________________________
EXAMPLE 7
In an stainless steel autoclave with an internal volume of 500 ml were charged 91.7 g (0.4 mol) of 4,4'-dimethoxydiphenylamine, 248.3 g (2.0 mol) of 4-methoxyphenol and 4.92 g of a surface-supported 5% Pd/C (at least 80% by weight of the carried Pd was supported within 1 μm from the surface of active carbon: 50 wet %) manufactured by N. E. Chemcat Co. After replacing the air in the autoclave with nitrogen, the autoclave was pressurized to 10 kg/cm 2 G with hydrogen. Continuously, the contents were reacted by heating and treated in the same manner as in Example 1. As a result, the selectivity of 4,4',4"-trimethoxytriphenylamine was 81.7%. Simultaneously, the selectivity of 4,4'-dimethoxytriphenylamine, the dealkoxylated compound, was 10.7%.
Comparative Example 1
The reaction and the treatment were carried out in the same manner as in Example 1 except that a uniform type 5% Pd/C which was not of the surface-supported type and was manufactured by N. E. Chemcat Co. was used as the hydrogen transfer catalyst. As a result, the conversion of the 4,4'-dimethoxydiphenylamine was 75.2%, while the selectivity of 4,4',4"-trimethoxytriphenylamine was 71.8%. Simultaneously, the selectivity of 4,4'-dimethoxy-triphenylamine, the dealkoxylated compound, was 19.4%.
EXAMPLE 8
In a 200-ml round flask provided with a reflux condenser equipped with a separator, a thermometer and a stirrer were charged 1.23 g of a surface-supported 5% Pd/C (at least 80% by weight of the carried Pd was supported within 1 μm from the surface of active carbon: 50 wet %) manufactured by N. E. Chemcat Co., 99.31 g (0.8 mol) of p-methoxyphenol and 6.41 g (0.05 mol) of 4-methoxycyclohexanone, and separately 12.32 g (0.1 mol) of 4-methoxyaniline were charged in a dropping apparatus. While being stirred, the contents in the reactor were heated to 200° C., to which the 4-methoxyaniline in the dropping apparatus was added dropwise over 7 hours while maintaining the contents at the same temperature under stirring. After completion of the dropping, the contents were further heated to 220° C. at which they were reacted for 9 hours. The water thus formed was azeotropically distilled by the addition of toluene, condensed in the reflux condenser and separated by the separator. Then, the reaction liquid was cooled, and the 5% Pd/C was separated by filtration from the liquid reaction mixture. The filtrate was analyzed by means of gas chromatography. As a result, the conversion of the 4-methoxyaniline was found to be 99.0%, and the selectivity of 4,4',4"-trimethoxytriphenylamine was 84.4%. Simultaneously, the selectivity of 4,4'-dimethoxytriphenylamine, the dealkoxylated compound, was 12.2%.
EXAMPLES 9 to 13
The reaction was carried out in the same manner as in Example 8, using a variety of anilines and alkoxy-substituted phenols given in Table 2 and alkoxy-substituted cyclohexanones corresponding to the alkoxy-substituted phenols. The results are illustrated in Table 2.
TABLE 2______________________________________ Conversion SelectivityExample Aniline Phenol (mol %) (mol %)______________________________________9 2-methylaniline 4-methoxyphenol 95.2 83.410 aniline 4-methoxyphenol 99.5 86.911 aniline 2-methoxyphenol 90.2 82.712 4-methylaniline 4-methoxyphenol 99.5 87.913 4-methoxy- 4-methoxyphenol 98.5 83.2 aniline______________________________________
EXAMPLE 14
In a stainless steel autoclave with an internal volume of 500 ml were charged 223.5 g (1.8 mol) of 4-methoxyphenol and 4.92 g of a surface-supported 5% Pd/C (at least 80% by weight of the carried Pd was supported within 1 μm from the surface of active carbon: 50 wet %) manufactured by N. E. Chemcat Co., and separately 24.6 g (0.2 mol) of 4-methoxyaniline were charged in a dropping apparatus. After replacing the air in the autoclave with nitrogen, the autoclave was pressurized to 10 kg/cm 2 G with hydrogen. Continuously, the contents were reacted by heating and treated in the same manner as in Example 8. As a result, the conversion of the 4-methoxyaniline was 88.5%, and the selectivity of 4,4',4"-trimethoxytriphenylamine was 80.9%. Simultaneously, the selectivity of 4,4'-dimethoxytriphenylamine, the dealkoxylated compound, was 13.5%.
Comparative Example 2
The reaction and the treatment were carried out in the same manner as in Example 8 except that a uniform type 5% Pd/C which was not of the surface-supported type and was manufactured by N. E. Chemcat Co. was used as the hydrogen transfer catalyst. As a result, the conversion of the 4-methoxyaniline was 98.3% and the selectivity of 4,4',4"-trimethoxytriphenylamine was 54.8%. Simultaneously, the selectivity of 4,4'-dimethoxytriphenylamine, the dealkoxylated compound, was 23.5%. | A process for producing an alkoxy-substituted tri-phenylamine comprising reacting an alkoxy-substituted cyclohexanone with a diphenylamine or an aniline, while forming said cyclohexanone in the same system from an alkoxy-substituted phenol by using said phenol as a hydrogen acceptor, in the presence of a hydrogen transfer catalyst and a catalytic amount of the alkoxy-substituted cyclohexanone corresponding to the alkoxy-substituted phenol used for the reaction, or after converting partially the alkoxy-substituted phenol to a catalytic amount of the alkoxy-substituted cyclohexanone under a hydrogen pressure in the presence of a hydrogen transfer catalyst, wherein a surface-supported catalyst is used as the hydrogen transfer catalyst. | 2 |
BACKGROUND
In healthy individuals, the level of platelets and other blood cells is maintained in a narrow band by an active feedback mechanism that balances the rate of production with that of loss due to peripheral consumption and clearance. Certain disorders such as bone marrow hypoplasia or acute myelogenous leukemia depress the rate of production, while other conditions, such as certain viral infections, or alloimmunization following exposure to foreign antigens, during pregnancy or as a result of blood transfusion, contribute to accelerated clearance.
In addition, chemotherapy, for patients with hematologic malignancies, impairs or completely suppresses the production of platelets from megakaryocytes (HarkerFinch1969), and even with finite residual production, platelet function in such patients may be impaired. Thus, Psaila2012 reports reduced expression levels of membrane glycoproteins including GPIb which binds to von Willebrand factor on (sub-)endothelial cells at sites of vascular injury (“lesions”) and thereby mediates platelet adsorption.
Hemorrhages of varying degree of severity remain a principal factor contributing to morbidity and mortality of patients receiving chemotherapy for hematologic malignancies, including bone marrow transplant candidates. While low platelet count per se may not be the cause of bleeding, it may exacerbate the risk of an insufficient response in the event (HoTin-Noe2011, Loria2013). Under current treatment guidelines (Slichter2005), patients receiving chemotherapy are managed in accordance with “one-size-fits-all” algorithms including triggers for prophylactic platelet transfusion. Many clinical studies over the past decade or more have sought to identify an “optimal” value for such a trigger, often by looking for a significant increase in frequency and severity of bleeding episodes at lower platelet count (Estcourt2012). At present, only “bleeds” causing visible symptoms (including petechiae, bruises or external blood loss) are routinely monitored or assessed during treatment, and changes in transfusion trigger, while often based on bleeding episodes, may not be correlated to the trigger levels, or changes thereof seSee, -Rioux-Masse B, Laroche V, Bowman R J et al. The influence of bleeding on trigger changes for platelet transfusion in patients with chemotherapy-induce thrombocytopenia Transfusion. 2013 February; 53(2):306-14.
However, inflammation, has been has been recently shown to cause of bleeding by impairing vascular integrity (Ho-Tin-Noe2011), and platelets have been shown to be “vital in maintaining vascular integrity (Nachman2008), especially in inflamed tissue (Goerge2008) This is a concern for patients receiving chemotherapy who frequently present with symptoms of inflammation, ranging from fever to sepsis.
Recent work indicates a role of platelets, beyond that of maintaining hemostasis, in modulating inflammatory reactions and immune responses by direct interaction with leukocytes and epithelial cells and by releasing inflammatory mediators (Assinger2014). In fact, transfusions themselves are known to be associated with an increased risk of infection as well as inflammation, where the latter may be caused or exacerbated by chemotherapy (vanderMost2008) and by hemolytic transfusion reactions (Strobel2008). Moreover, it has been observed, in a mouse model, that severe platelet deprivation leads to splenic necrosis, with deleterious effects on innate and adaptive immune responses to certain infectious agents (Loria2013).
Thus, individual requirements for maintaining vascular integrity may change over time, and may differ between patients, in a manner reflecting inflammatory and perhaps other clinical conditions.
Accordingly, a method is needed to determine individual transfusion regimens, especially for severely thrombocytopenic patients, by assessing the individual (and possibly time-varying) need for support in relation to the condition of the patient, by assessing that condition, non-invasively and continually, and determining the requirement for maintaining an adequate level of platelets in circulation to ensure a protective immune response, and satisfying the demand for platelets in maintaining vascular integrity. To ensure adequate quantities of antigen-profiled platelets are available to needy patients, and to reduce cost, the method should avoid excess utilization of platelets (and related services), such as the administration of any particular antigen-profiled platelets. The method may also ensure that patients who may have developed allo-antibodies to platelets are administered sufficient quantities of platelets of the correct type to ensure a protective immune response, and maintain vascular integrity.
SUMMARY
The invention relates to treating patients and managing inventories of cells, particularly platelets. It includes methods to manage the transfusion support of patients in accordance with individual conditions, by providing a method for monitoring and assessing, in real time, the demand for platelets in maintaining vascular integrity and, on the basis of that assessment, determining an individual cell administration regimen for administering platelets or other cells—where the cells or platelets are preferably typed or profiled; and where the regimen avoids or minimizes excess administration of such platelets or other cells.
The methods of the invention comprise: determining and implementing individualized platelet support regimens (e.g., administering specified platelet cell numbers; and, schedules for administration or other intervention) by: monitoring platelet consumption kinetics; analyzing the kinetics to determine value(s) proportionally representing both the extent and frequency of vascular injury, estimating from these values a minimal demand for platelets (per time period, say 1 day) in repairing vascular injury, and using such value(s) to determine the momentary requirement for maintaining vascular integrity, and constructing a corresponding platelet administration regimen.
Preferably, the regimen utilizes typed or profiled platelets in accordance with the molecular attributes of patients, and comprises releasing from the platelet inventory system the particular typed or profiled platelet amounts required to satisfy the platelet administration regimen of each patient. Excess administration of particular typed or profiled platelets is avoided. Tracking of such cells, held in inventory for administration, ensures availability of needed typed cells, when required, and significantly enhances public health. The invention further relates to establishing a replenishing inventory of antigen-typed or antigen-profiled platelets or other cells, which are perishable and may be replaced after expiration, where the inventory can be virtual or held across several locations.
In another embodiment of the invention, an individual's platelet requirement is satisfied by adopting an optimized administration regimen whereby platelets are selected in accordance with the patient's molecular attribute profile and/or antigen status in order to avoid antibody binding and premature platelet removal. If the patient has formed antibodies in response to exposure to foreign antigens during pregnancy or by previous transfusion, or, on the basis of his or her antigen profile, is at risk of making antibodies in response to exposure to foreign antigens expressed on platelets from random donors, then such antibodies, by binding to such transfused platelets, mark the platelets for instant removal, as if they were senescent. To avoid exposure to such foreign antigens, the optimized administration regimen is used to maintain sufficient platelet levels.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a graph recording platelet count by date for a patient receiving transfusions in support of chemotherapy. There is an initial steep linear decay in platelet count, indicated by the dashed line, from levels at the upper end of the normal range (indicated by the two horizontal lines at approximately 130 K/μl and 450 K/μl) to approximately 60 K/μl.
FIG. 2A is a histogram (probability density vs. transfusion interval) of mean values of histograms of transfusion interval sets for a group of ˜200 antibody-negative patients receiving platelet transfusions in support of chemotherapy for hematologic malignancies. The solid line represents the gamma distribution with shape and scale parameters determined from the moments of the histogram, with mean=2.1 and variance=0.65.
FIG. 2B is a histogram of mean values of histograms of transfusion interval sets for a group of ˜200 patients (different from the group of patients in FIG. 2A , and including some antibody-positive patients) receiving platelet transfusions in support of chemotherapy for hematologic malignancies; as in FIG. 2A , the solid line represents the gamma distribution with shape and scale parameters determined from the moments of the histogram, with mean=2.1 and variance=0.65; in contrast to FIG. 2A , the histogram now is bi-modal, displaying an additional (“fast”) peak, at <1, attributable to a process of antibody-mediated platelet clearance that operates in parallel with the process of vascular injury repair described by the process of the invention.
FIG. 3 shows examples of survival curves for labeled and unlabeled platelets, predicted by the stochastic model of vascular injury repair. The x-axis shows time, in days, the y-axis shows the fraction of initial labeled and unlabeled platelets surviving.
FIG. 4 shows a Table 1, which is a summary of survival curves of 51 Cr-labeled platelets injected into normal subjects, with a pre-transfusion circulating platelet count of 250,000/μl and three groups of patients with bone marrow hypoplasia of differing severity, indicated by the decreasing pre-transfusion circulating platelet counts (FIG. 1 in Hanson&Slichter1985). For each group, the fraction of 51 C-labeled platelets surviving is shown as a function of time.
FIG. 5 shows a Table, which is a worksheet illustrating the determination of the rate λ (per μl per day) of consumption of platelets in maintaining vascular integrity that, in combination with the loss of platelets due to senescence, at a rate σ, expressed as a fraction of the number of platelets remaining in circulation, ensures a decrease in the circulating platelet count from the expected maximum attained immediately following a transfusion with the specified “Parameters,” (as indicated in the column) to the level of 10,000/μl (at which point intervention is triggered) within a preset period, here 2 days. Note that all values less than 0, i.e., negative numbers, are to be ignored.
FIG. 6 shows a plot of “Platelet Count Decay,” displaying the decrease in platelet count as a function of time. Note that all values less than 0, i.e., negative numbers, are to be ignored.
DETAILED DESCRIPTION
Definitions
“Platelet requirement” or “platelet transfusion requirement” refers to not substantially less than the amount of platelets required to be transfused to a patient to repair the estimated vascular injury and replenish platelets lost to senescence; where “not substantially less” refers to the amount of platelets required to produce a platelet concentration within a range of 10,000/μl, or preferably 5,000/μl or preferably 1,000/μl of the platelet concentration meeting the platelet requirement. “Instantaneous platelet requirement” refers to a platelet requirement determined to exist for a specific patient at a specific time
“Administration regimen” or “support regimen” refers to a schedule of platelet administration comprising amounts and types of platelets or other cells administered in accordance with a determined mode (such as continuous or intermittent) at a specific rate wherein mode or rate may vary with time. “Optimized administration regimen” or “optimized support regimen” refers to an administration or support regimen that is optimized by selecting platelets in accordance with a molecular attribute of the intended recipient
The invention includes a novel method for determining an individual platelet transfusion requirement, where, first, one assesses vascular injury by monitoring and analyzing platelet survival curves. For patients receiving chemotherapy, the survival curves may be recorded by taking periodic readings of the circulating platelets following a platelet transfusion. Next, one determines an individual platelet treatment regimen, reflecting the platelet requirement so determined. The regimen includes constructing a prescription of the number of platelets to be administered, and a schedule of administering said number of platelets including the possibility of continuous administration. In one embodiment, the prescription calls for the number of platelets given to be no less than the momentary rate of platelet consumption in the repair of vascular injury. In another embodiment, the prescription calls for the number of platelets to be given to be sufficiently large to ensure that the count stays above a preset threshold for at least a preset time, Δt. In yet another embodiment, the prescription calls for maintaining platelets at or near constant level, by setting the rate of infusion to balance or approximately balance the rate of loss.
By using the method of determining a platelet administration regimen and prescription in relation to a patient's condition, by reducing platelet utilization, platelets of particular types are preserved without risking adverse events for the patient. The inventory of platelets of particular types is tracked, when: they reach expiration, or are removed from inventory for administration, or are replenished. The inventory can be a virtual inventory of antigen-profiled platelets or cells, as described in US Publ'n No. US 2013/0317845 (incorporated by reference). In US Publ'n No. US 2013/0317845 the virtual inventory exists between an exchange and multiple entities which actually hold the inventory, and can involve a conditional sales agreement between the exchange and such entities, where the exchange has rights to specific inventory covered under the agreement.
Non-Invasive Assessment of Vascular Injury by Analysis of Platelet Survival Curves
At least two processes contribute to platelet consumption:
1. the steady removal of senescent platelets, in healthy individuals at a daily rate of ˜10% of the total number (Harker1969), as determined by an internal molecular clock (Dowling2010). In patients with existing antibodies directed to antigens expressed on the surface of platelets, notably including Human Leukocyte Antigens of class I (“HLA class I”) and Human Platelet Antigens (“HPA”), platelet opsonization marks platelets for clearance, thereby significantly reducing the normal platelet lifespan of ˜10 d. (Harker1969). Thus, for present purposes, unless explicitly mentioned, we include the clearance of antibody-decorated (“opsonized”) platelets under senescence; and 2. the recruitment of platelets to sites of vascular injury as an integral part of the process of maintaining vascular integrity: an estimate of 7,100/μl*day, in Hanson1985, has been widely cited in the literature; more recent work, on mouse models, places the estimate at 10-15% of the normal platelet level, corresponding, in humans to 35,000/ul-47,500/u (Loria2013).
Assuming this range of values, loss of platelets to senescence will be the pre-dominant process at normal levels; however, at low platelet levels, when the contribution to senescence (in the absence of antibodies) drops to low values, the fixed consumption in the repair of vascular injury may dominate. Hence, for patients with impaired platelet production, either congenital or acquired, the latter especially as a result of chemotherapy, it will be critical, in order to construct an optimized platelet prescription (quantity of platelets and interval of administration in relation to a momentary platelet requirement) to better understand the vascular repair process. Particularly important in this context is the observation, in recent work on a mouse model, that inflammation causes bleeding in thrombocytopenia, and that platelets are “indispensable to maintaining vascular integrity in inflamed tissue.” (Goerge2008).
Platelet Survival Curves
Over a period of 35 years, from the early fifties to the mid-eighties, the fundamentals of thrombokinetics, including the lifetime of platelets in circulation, their sequestration in spleen and liver, and the disorders of platelet production, distribution and consumption, were elucidated by injecting isotopically labeled platelets into normal subjects as well as patients with various disorders, and monitoring the decay of radioactivity over time, thereby generating survival curves (HarkerFinch1969). Labeling is necessary whenever the platelet level remains constant. When platelet production is attenuated or completely suppressed, counts may be determined directly, using a hemocytometer or other method of particle counting. Platelet survival curves simply record the count of labeled or unlabeled platelets remaining in circulation as a function of time after transfusion. Often, counts are normalized in a convenient manner, for example, for labeled platelets: to an initial reference level of radioactivity or fluorescence, or, for unlabeled platelets, by computing a corrected count increment.
Modeling Vascular Injury Repair as a Stochastic Process
The methods herein represent the process underlying the consumption of platelets in the repair of vascular injury as a stochastic process. Vascular injury is modeled in the form of lesions in the vasculature, which arise spontaneously, in accordance with a Poisson process of rate λ, and exponentially distributed severity or size, with mean μ. This stochastic process generates an average requirement for λμ platelets over a characteristic time period, say a day. In combination with the clearance of senescent platelets, at an internally preset rate a, the consumption of platelets in the repair of vascular lesions determines the kinetics of the platelet count evolution which may be recorded in the form of platelet survival curves.
Contrary to a widely cited view (Hillyer C D. Blood Banking and Transfusion Medicine: Basic Principles & Practice. Churchill, Livingston, Elsevier, 2 nd Ed, 2007. Chapt 33, p 458), originating with Hanson & Slichter (Hanson19985), that the platelet requirement for repairing vascular injury is a fixed requirement, the re-analysis of published survival curves using a stochastic model of vascular injury repair as disclosed herein does not support a fixed requirement (see also EXAMPLE 2, below). Rather, the number of requisite platelets is shown to depend on the patient's condition. Thus, a need arises to assess, in individual patients, the minimal level of platelets required to support the critical function of repairing vascular injury.
The method of the invention comprises the steps illustrated by the following pseudo-code:
# Definitions
σ: rate of removal of senescent platelets, that is: the percentage of platelets that have survived
to the end of their natural lifespan of typically 10d; thus, a typical value would be ≦10%
per day of the total number of platelets.
λ: the daily rate of occurrence of lesion “events”, expressed as a number of platelets per μl
per day: typical values may be in the range 5,000/μl to 15,000/μl.
μ: the mean value of lesion size, expressed as the number of platelet consumed in the repair
of a lesion of that size; thus, λμ represents the mean number of platelets consumed per day
in maintaining vascular integrity.
π: daily rate of production of platelets; in a healthy individual; typical value: 35,000/μl
(Harker&Finch1969).
N 0 : total number of platelets, including those sequestered in spleen; typical value for a healthy
individual: 350,000/μl, where typically 1/3 of this number is sequestered in the spleen
(Aster1966).
Φ 0 : percentage of labeled platelets, if any; typical value: 5-10% if autologous, 50% if
homologous platelets are used for generating survival curves.
T: maximum run time, in days; typical value: 10.
# define function
C <- function(n,UseExp=TRUE)
{
# set event size by sampling from a constant (UseExp=FALSE) or
# from an exponential (UseEXp=TRUE) event (“lesion”) size distribution
# n: integer, specifying mean event size
# UseExp: logical: if set, use exponential, otherwise constant event size distrib
return(if(UseExp) n*rexp(1) else n/exp(1))
}
# load data (to which model simulation is to be compared)
sCurve <- loadData(patientPlateletSurvivalCurve)
# initialize parameters (NOTE: λ, μ are the only adjustable parameters)
(λ, μ, σ, π) <- initializeParameters( )
(N 0 , (Φ 0 ) <- initializeParameters( )
T <- initializeParameters( )
# initialize variables using parameters set above
I <- 1
# indicator variable
t <- 0
# elapsed time
te <- -log(runif(1))/ λ
# time of next event for Poisson proc
b <- b0 <- (1- Φ 0 )* N 0
# b (“blue”): unlabeled plt;
r <- r0 <- Φ 0 * N 0
# r (“red”): labeled plt
db <- 0; dr <- 0;
# differentials for b, r
# initialize data structure holding simulation outputs
bPath <- as.vector(b)
# holds number of unlabeled platelets
rPath <- as.vector(r)
# holds number of labeled platelets
dbPath <- as.vector(0)
# holds decrement of unlabeled platelets
drPath <- as.vector(0)
# holds decrement of labeled platelets
tePath <- as.vector(te)
# holds event (“lesion”) times
ePath <- as.vector(0)
# holds event (“lesion”) sizes
# main loop
while( (te <= T) & (I ==1) ) }
# evolution of r and b platelet counts reflecting senescence and residual production of unlabeled
plt
b <- b - σ*b0*(te-t) + π *(te-t)
# balance of unlabeled plt: senescence and residual prod
r <- r - σ*r0*(te-t)
# balance of labeled plt: senescence
# vascular “lesion” event, at t=te:
evSize <- C(μ,UseExp)
# total plt consumed in event (= repair of vascular
lesion)
db <- evSize*b/(b+r)
# compute number of unlabeled platelets consumed in event
dr dr <- evSize*r/(b+r)
# compute number of labeled platelets consumed in
event
b0 <- b0 - ((b- π *(te-t))/b)*db
# adj b0 by fraction of ORIGINAL “b” plt consumed in
event
r0 <- r0 − dr
# adj r0 by fraction of ORIGINAL “r” plt consumed in event
b <- b - db
# adj number of “currently” remaining unlabeled
platelets, b
r <- r - dr
# adj number of “currently” remaining labeled platelets, r
if( (b <= 0)|(r <= 0) ) I <- 0
# check whether unlabeled and labeled plts remains positive
t <- te
# update elapsed time
te <- t - log(runif(1))/λ
# generate new event time
# record simulation output(s) (“book keeping”)
bPath <- c(bPath,b)
rPath <- c(rPath,r)
dbPath <- c(dbPath,db)
drPath <- c(drPath,dr)
tePath <- c(tePath,te)
ePath <- c(ePath,evSize)
{
The main loop may be deployed as part of a standard non-linear regression routine such as the R function “n1s2” (see e.g., website entitled “Non-linear regression with brute force” by G. Grothendieck) seeking optimal values for λ, μ, σ and π so as to minimize an r 2 -value computed from fits, notably the survival curve of labeled platelets (in rPath) or unlabeled (in bPath) and data (in sCurve). Typically, π, and, in some cases (for example for normal subject or patients, with high platelet count), σ, would be held fixed at their respective initial values, and only λ and μ would be varied. The optimal values for the latter two parameters then directly provide frequency and typical size of randomly occurring vascular lesions, in terms of the number of platelets required for lesion repair. In actual fact, what matters is the total, λμ, of platelets consumed in vascular lesion repair. Thus, when sampling event sizes from a constant distribution (UseExp=FALSE), the stochastic process simplifies to a pure Poisson process and μ may be set to 1 without restriction of generality
For platelet curves recorded with labeled platelets, the method of the invention yields curves which may vary in shape from linear to exponential, depending on the rate of production, π. For platelet survival curves recorded without labeling, the method of the invention yields a linear decay. In either case, λ and μ may be directly extracted from the regression analysis.
Thus, in contrast to the view expressed in the literature, namely “that analysis of platelet survival curves may not provide insight into the mechanism normally responsible for the removal of platelets from circulation” (Hanson1985 and refs therein), the method of the invention, by way of analyzing survival curves, permits the determination of the relevant parameters, λ, μ and σ; in addition, the method permits the detection of alloimmunization, which manifests itself in the form of accelerated senescence. In essence, this embodiment of the invention converts the platelet count evolution captured in the form of a survival curve into an internal indicator for the frequency and size of vascular lesions consuming a fraction of the platelets in circulation.
To the extent that the frequency and size of vascular lesions reflect inflammation, this determination also would represent a non-invasive method of assessing the “internal” inflammatory condition of the patient's vasculature.
In-Vivo Evaluation of Graft Donor Compatibility
A further application of the method of the invention is that of evaluating the recipient immune response to HLA-class I and/or HPA antigens expressed on the platelets of a prospective organ or stem cell donor. Radioactively or fluorescently labeled platelets, collected from the prospective donor, would be prepared by standard methods (Harker1969), injected into the recipient, and monitored to determine a survival curve for the labeled platelets, generating data such as those in Table 1. Differential labeling, e.g., with different fluorescent dyes, and monitoring by standard flow cytometry would permit the analysis of the differential clearance kinetics for the recipient's own platelets compared to that for the prospective donor platelets and thereby permit an assessment of the anticipated adverse immune response to a stem cell or organ graft expressing HLA-class I and/or HPA antigens.
Dosing by Individual Platelet Requirement
An additional aspect of the method of the invention is the administration of platelets in accordance with a dosing regimen reflecting the platelet requirement of individual patients at specific times, as determined from the platelet clearance kinetics, in accordance with the methods disclosed herein.
Transfusion Service Performance Assessment
In one respect, the invention provides a process for assessing the allo-antibody status of a patient population. Given the common current clinical practice of performing an antibody status determination (“screen”) and specificity determination only in special circumstances, such as in connection with the evaluation of hematology patients as stem cell transplant candidates, this process is especially useful as a means to assess the expected burden of managing patients expected to have, or to develop, antibodies directed to platelets (and by extension to other cells such as red cells), given that sensitized patients require support with special platelets and/or other cells selected to minimize adverse immune reactions; further, the process permits an assessment of the performance of providing this type of special support, assessed by the degree to which further sensitization (ak alloimmunization) has been avoided.
This assessment proceeds by analysis of platelet transfusion records, and especially of the distribution of transfusion intervals—that is: the time between successive transfusions—in order to estimate the percentage of patients in a selected sample population with antibodies directed to antigens expressed on platelet surfaces. This process comprises the following steps:
construct histograms of the histogram means for individual transfusion interval series such as those in FIG. 2A and FIG. 2B herein; applying the stochastic process of the invention, determine the contribution to platelet clearance attributable to vascular injury repair (see also Example 3). In a preferred embodiment, this step comprises parametrization in terms of a gamma distribution and reference to parameters determined for populations of patients known not to have been sensitized; identify any (remaining) contribution to the histogram not attributable vascular injury repair and attribute it to antibody-mediated clearance. Note thatFIG. 2 B displays a peak at ˜2 d attributable to the vascular injury repair process and a resolved “fast” peak, at <1 d, attributable to the antibody-mediated clearance process; estimate the magnitude of relative contributions to the clearance kinetics of the two processes operating in parallel, namely: vascular injury repair and antibody-mediated clearance, by comparing respective peak areas or amplitudes: these provide estimates of the proportion of “fast” transfusion intervals observed in the transfusion record; estimate the proportion of antibody-positive and anti-body negative patients in the population described by the transfusion records, by bootstrap sampling of the population, with reference of the probability, S(n)=prob(N>n), that a patient receives in excess of N transfusions.
In another embodiment of the invention, the regimen of administering platelets may be adjusted for patients so as to increase the volume transfused, thereby increasing the platelet count attained immediately following transfusion (see also: Example 3, below), thereby increasing the time to the next transfusion; and reflecting the operation of only the process of vascular injury repair. As the “fast” peak reflecting the operation off antibody-mediated clearance will remain unaffected, such an adjustment in transfused volume will increase the peak resolution in any bimodal histogram such as that in FIG. 2B .
In another respect, the method of the invention permits a real-time determination of the demand for platelets in maintaining vascular integrity (namely by mediating the repair of vascular injury). This demand may vary over time, reflecting, for example, the patient's inflammatory condition (Ho-Tin_noe2011). Thus, in contrast to the recommendation in current clinical guidelines, of relying on a universal minimal preset value of the platelet count to indicate a prophylactic platelet transfusion, the method of the invention permits the platelet support to be based on an individual value that that is close to the actual demand for platelets for the repair of vascular injury. This allows avoidance of over-administration of platelets.
The methods of the invention are illustrated by the following examples.
Example 1
Determine λμ from platelet count evolution for a patient receiving chemotherapy, with negative anti-HLA screen
FIG. 1 is a survival curve for a leukemia patient, generated by recording platelet count at approximately daily intervals following initiation of chemotherapy (hence at least partial suppression of platelet production). A linear fit to the initial decay produces a daily turnover of approximately ((435,000-60,000)/μl)6 d or 62,500/d. According to the method of the invention, the turnover rate represents the combination of clearance of senescent platelets and consumption in the repair of vascular lesions, in accordance with the stochastic model of vascular injury disclosed herein, namely:
T t =T 0 +(π−σ−λμ) t
and, for π=0:
T t =T 0 −(σ+λμ) t
With σ=0.1*T 0 , or 43,500/μl per day, this yields an estimate for consumption in vascular injury repair of λμ=19,000/0. In general, σ can be time-dependent.
Example 2
Concurrently determine σ, λμ and from survival curves recorded with labeled platelets for normal subjects and patients with stable thrombocytopenia (see Table 1 showing data extracted from FIG. 1 of HansonSlichter1985).
Survival curves recorded with 51 Cr-labeled platelets for normal subjects and for patients with thrombocytopenia secondary to bone marrow hypoplasia display a linear or near-linear decay in the normalized count, ν(t)=N(t)/N(t=0), of the number, N(t), of labeled platelets remaining at time t after (re-)transfusion of autologous platelets. In these subjects, platelets are produced at a rate, π, matching the rate of loss due to senescence, σ, and vascular injury repair, λμ, and in this steady state, the method of the invention, as disclosed in form of pseudocode, permits the determination of λ, and μ for fixed σ=0.1. Alternatively, the simulation of the stochastic process by the algorithm disclosed herein as pseudocode permits the estimation of λμ as follows:
Λμ
Cohort 1 (normal subjects,
1,300/μl
250,000, first set in Table 1):
Cohort 2 (thrombocytopenic,
3,300/μl
62,000/ul, second set in Table 1):
Cohort 3 (thrombocytopenic,
5,300/μl
37,000/ul, third set in Table 1):
Cohort 4 (thrombocytopenic,
9,700/μl
19,000/ul, fourth set in Table 1):
Example 3
Determine λμ from the distribution of transfusion intervals for individual patients receiving chemotherapy for the treatment of hematologic malignancies ( FIG. 2 , Table 2). From the transfusion history, comprising a record of multiple platelet transfusions, or a selected portion thereof, limited to a preset range of dates or times, generate a histogram of the interval, τ, between successive transfusions (aka “transfusion interval”): τ represents the nominal time for the platelet count to decay from the maximum attained following the infusion of platelets, corrected for splenic sequestration (Aster1966), to a predetermined minimal value of, e.g., 10,000/ul (aka “transfusion threshold” or “transfusion trigger”). Given the volume transfused, at the transfusion threshold, the rate λμ may be estimated from the distribution of τ by performing the following steps:
Step 1—Determine the expected maximum total platelet count following transfusion of a known volume of platelets;
NOTE—200 ml of a pooled platelet suspension, comprising 4 units of 0.5*10 11 platelets each, contains 4*10 11 platelets; transfusion, at a “trigger” level of 10,000/μl, to an individual with a typical blood volume of 5,000 ml, produces an expected maximum count increment of ˜40,000/μl, rapidly reduced to ˜26,000/μl by splenic sequestration of ˜35% of the newly transfused platelets (Aster1966, Harker1969), thus a maximum expected post-transfusion count of 36,000/μl (=10,000/ul+26,000/ul) in circulation, corresponding to a total platelet count of 55,380/μl (=(36,000/0.65)/μl)
Step 2—Tally total count reflecting the loss of senescent platelets, at a daily rate of 10% of 55,380/μl, as well as the consumption of platelets in maintaining vascular integrity, at the unknown rate, λ;
Step 3—Determine λ so as to ensure the reduction of the circulating count back to the trigger level in a preset elapsed time, τ;
With reference to FIG. 2 , this method yields the following estimates: with 200 ml of transfused platelets, a daily rate of λ=17,200/μl returns the count to the trigger level of 10,000 μl in τ=2 d, a rate of λ=10,300/μl does so in 3 d; with a volume of 250 ml of transfused platelets, a daily rate of λ=13,200/μl lowers the count to the trigger level in 3 d.
This method thus permits the determination of λ from the analysis of the patient's transfusion history comprising a record of dates and times of platelet transfusions.
Example 4
Optimize dosing: INCREASE the number of platelets transfused in order to DECREASE the frequency and cost of transfusion support.
As illustrated here for a linear decay in platelet count, for patients with minimal or no platelet production, a higher average level may be maintained, while reducing total expense, by increasing the volume of each transfusion, thereby increasing the time between transfusions.
A platelet transfusion comprising 3E11 platelets (e.g. in the form of a platelet pool of 6 units of 0.5E11 platelets each), given at a level of 10,000/μl, is expected to produce a maximum post-transfusion count of 70,000/μl (assuming a total blood volume of 5 liters) and 46,200/μl after splenic sequestration. Assuming removal of senescent platelets, at a rate of 10% of the initial value, and assuming a daily rate of platelet consumption for maintaining vascular integrity of kV=12,000/μl, the average transfusion interval, dt, would be 1.8 days, yielding an expected number of 60/dt transfusions over a 60 day period. Assuming $500 per platelet product, and $1,000 for the total cost of administering the platelets (Shander2010), the total expected cost would be ˜$49.2K.
Administering two bags of platelets, at a total cost of 2*$500+$1,000, increases the average dt to 2.92 days, and reduces the expected number of transfusions accordingly, thereby lowering the expected total cost to $41.1K.
Example 5
Continuous administration of platelets at a rate maintaining a preset platelet level.
To maintain the platelet count at a preset level, administer platelets continuously—for example by platelet drip—and set the rate of infusion so as to match the rate of loss determined by the methods disclosed herein, to establish a de-facto steady state (or near-steady state, with excursions of the platelet count maintained in a preset band), by adjusting the rate of infusion to match the rate of platelet loss due to clearance of senescent platelets and consumption of platelets in maintaining vascular integrity (and possible additional factors, notably the antibody-mediated accelerated clearance of opsonized platelets).
Thus:
determine the rate of platelet loss by analyzing survival curve(s) following platelet infusion for a patient receiving chemotherapy, with (at best) a low rate of platelet production; by the methods of the invention, determine the rate of consumption of platelets in maintaining vascular integrity; set a target platelet count no lower than the level corresponding to the total number of platelets lost per day, computed from the said rate of platelet loss; administer platelets by continual infusion at a rate exceeding the said rate of loss by a preset margin; after a preset time, reduce the said rate of administration to the said rate of loss in order to maintain the platelet count at a preset level
The specific methods and processes described herein are representative of preferred embodiments and are exemplary and not intended as limitations on the scope of the invention. Other objects, aspects, and embodiments will occur to those skilled in the art upon consideration of this specification, and are encompassed within the spirit of the invention as defined by the scope of the claims. It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, or limitation or limitations, which is not specifically disclosed herein as essential. Thus, for example, in each instance herein, in embodiments or examples of the present invention, any of the terms “comprising”, “including”, containing”, etc. are to be read expansively and without limitation. The methods and processes illustratively described herein suitably may be practiced in differing orders of steps, and that they are not necessarily restricted to the orders of steps indicated herein or in the claims. It is also noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference, and the plural include singular forms, unless the context clearly dictates otherwise. Under no circumstances may the patent be interpreted to be limited to the specific examples or embodiments or methods specifically disclosed herein. Under no circumstances may the patent be interpreted to be limited by any statement made by any Examiner or any other official or employee of the Patent and Trademark Office unless such statement is specifically and without qualification or reservation expressly adopted in a responsive writing by Applicants.
The stochastic process of the invention, preferably in its analytical formulation, provides the basis for the design of specific platelet administration regimens, as exemplified herein below, namely by permitting, in analogy to pharmacokinetic and pharmacodynamic (“PK/PD”) modeling of modern pharmacotherapy, where “pharmacokinetics describes the drug concentration-time courses in body fluids resulting from administration of a certain drug dose” and “pharmacodynamics the observed effect resulting from a certain drug concentration” (Meibohm1997, Int J Clin Pharmacoll Ther 1997, 35(10):401-13).
The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intent in the use of such terms and expressions to exclude any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention as claimed. Thus, it will be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.
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All References, Patents and Applications Mentioned Herein are Hereby Incorporated by Reference
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Hillyer2007—Hillyer C D. Blood Banking and Transfusion Medicine: Basic Principles & Practice. Churchilll, Livingston, Elsevier, 2 nd Ed, 2007. Chapt 33, p 458
Ho-Tin-Noe, B, Demers M, Wagner D D. How platelets safeguard vascular integrity. J Thromb Haemost 2011; 9(Suppl 1): 56-65.
Nachman2008—Nachman R L, Rafii S. Platelets, Petechiae, and Preservation of the Vascular Wall. N Engl J Med 2008; 359(12): 1261-70.
Psaila2011—Psaila B, Bussel J B, Frelinger A L, Babula B, Linden M D, Li, Y, et al. Differences in Platelet Function In Patients with Acute Myeloid Leukaemia and Myelodysplasia Compared to Equally Thrombocytopenic Patients with Immune Thrombocytopenia. J Thromb Haemost. 2011; 9(11): 2302-10.
Slichter2005—Slichter S J, Davis K, Enright H, Braine H, Gernsheimer T, Kao K J, et al. Factors affecting posttransfusion platelet increments, platelet refractoriness, and platelet transfusion intervals in thrombocytopenic patients. Blood. 2005; 105:4106-14
Shander2010—Shander A, Hofmann A, Ozawa S, Theusinger 0 M, Gombotz H, Spahn D R. Activity-based costs of blood transfusion in surgical patients at four hospitals. Transfusion 2010; 50: 753-65.
Strobe12008—Strobel E. Hemolytic Transfusion Reactions. Transfus Med Hemother 2008; 35:346-353
TRAP1997—TRAP Study Group. Leukocyte reduction and ultraviolet B irradiation of platelets to prevent alloimmunization and refractoriness to platelet transfusions. The Trial to Reduce Alloimmunization to Platelets Study Group. New Engl J Med 1997; 337(26):1861-69. | Determining and implementing individualized platelet support regimens (e.g., administering specified platelet numbers; and, schedules for administration or other intervention, in accordance with the requirements assessed for individual patients) by: monitoring platelet clearance kinetics; analyzing the kinetics to determine value(s) proportionally representing both the extent and frequency of vascular injury, and using such value(s) to determine the momentary requirement for maintaining vascular integrity, and constructing a corresponding platelet administration regimen where said regimen preferably provides for the utilization of platelets selected, from a platelet inventory, in accordance with the recipient's molecular “type”. Releasing from an inventory of a platelet inventory system the particular typed or profiled platelet amounts required to satisfy the platelet administration regimen of each patient. Establishing a replenishing inventory of antigen-typed or antigen-profiled platelets or other cells, which are perishable and may be replaced after expiration, where the inventory can be virtual or held across several locations. | 6 |
FIELD OF THE INVENTION
This invention relates to a method for extending multiple radial fractures obtained in a single wellbore during controlled pulse fracturing (CPF) of an underground formation by subsequent utilization of a blocking agent and hydraulic fracturing in such a manner as to create multiple sequential hydraulic fractures.
BACKGROUND OF THE INVENTION
It has been known for some time that the yield of hydrocarbons, such as gas and petroleum, from wells can be increased by fracturing the formation so as to stimulate the flow of hydrocarbons into the well. Various formation fracturing procedures have been proposed and many now are in use. Among these procedures are treatments with various chemicals (usually acids in aqueous solutions), hydraulic fracturing in which liquids are injected under high pressure (usually with propping agents), explosive methods in which explosives are detonated within a formation to effect mechanical fracture, and combinations of the above procedures.
A combustion method designed to stimulate a well through mechanical fracturing is known as controlled pulse fracturing (CPF) or high energy gas fracturing. A good description of this method appears in an article by Cuderman, J. F., entitled "High Energy Gas Fracturing Development," Sandia National Laboratories, SAND 83-2137, October 1983. Using this method enables the multiple fracturing of a formation or reservoir in a radial manner which increases the possibility of contacting natural fractures. Unfortunately, these radial fractures often do not penetrate deeply enough into the formation.
A hydraulic fracturing method designed to control fracture trajectories in a formation penetrated by two closely-spaced wells is known as sequential hydraulic fracturing. In sequential hydraulic fracturing, the direction that a hydraulic fracture will propagate is controlled by altering the local in-situ stress distribution in the vicinity of the first wellbore. By this method, a hydraulic fracturing operation is conducted at the first wellbore wherein a hydraulic pressure is applied to the formation sufficient to cause a hydraulic fracture to form perpendicular to the least principal in-situ stress. While maintaining pressure in this first hydraulic fracture, a second hydraulic fracture is initiated in the second wellbore. This second hydraulic fracture, due to the alteration of the local in-situ stresses by the first hydraulic fracture will initiate at an angle, possibly perpendicular, to the first hydraulic fracture. In propagating, this second hydraulic fracture then has the potential of intersecting natural fractures not contacted by the first hydraulic fracture, thereby significantly improving the potential for enhanced hydrocarbon production and cumulative recovery.
Therefore, what is needed is a method which combines both CPF and sequential hydraulic fracturing techniques in order to extend these controlled pulse fractures so as to permit removal of increased amounts of natural resources from an underground formation. Practicing the present invention will allow for the creation of fracture extensions emanating from CPF induced radial fractures so as to connect with natural fractures and allow for the production of increased amounts of natural resources from a formation. Even in the absence of natural fractures, productivity will be increased due to the additional multiple fracture surface areas created by practicing this invention.
SUMMARY OF THE INVENTION
This invention is directed to a method for extending multi-azimuth vertical radial fractures resultant from CPF treatments. To accomplish this, multiple vertical radial fractures are created in a subterranean formation by energy resultant from a CPF method. These multiple radial fractures are short in length. Following the CPF treatment, hydraulic pressure is applied to the wellbore in an amount sufficient to fracture the formation. Upon commencement of the hydraulic fracturing treatment, a first hydraulic fracture is initiated from the CPF created radial fracture which is closest to being substantially perpendicular to the least principal in-situ stress.
While maintaining the hydraulic pressure on the formation and propagating this first hydraulic fracture, alternating slugs of thin-fluid spacer and gelled proppant slurry, or quick-setting blocking polymer, with or without proppant, are pumped into this fracture. After penetrating into the formation for a substantial distance, this first instituted hydraulic fracture "screens out", thereby preventing additional fluid from entering the fracture.
The pumping rate and hydraulic pressure are maintained and not allowed to drop thereby causing a second hydraulic fracture to be initiated. The second hydraulic fracture initiates from the tip of another radial fracture. The specific radial fracture from which a hydraulic fracture will be initiated is that fracture which has the least closure stress resulting from the interaction of the first hydraulic fracture and the original in-situ stress. This second hydraulic fracture has a trajectory which curves away from the first hydraulic fracture and is subsequently propagated perpendicular to the least principal in-situ stress. As was done with the first hydraulic fracture, the second hydraulic fracture is propagated while pumping alternating slugs of spacer fluid and a temporary blocking agent with proppant therein.
Once the second fracture screens out, a third hydraulic fracture originates from the tip of the next radial fracture which has the least closure stress resulting from the interaction of said first and second hydraulic fractures and the original in-situ stress. Hydraulic fracturing pressure and the pumping rate are maintained as above mentioned and another curved fracture is propagated. These steps are repeated until a sufficient number of desired propped sequential hydraulic fractures are induced in the formation. Thereafter, increased volumes of desired natural resources are produced from the formation, particularly hydrocarbonaceous fluids.
It is therefore an object of this invention to create more than two simultaneous multiple radial vertical fractures near a wellbore in a formation.
It is another object of this invention to avoid damaging the rock near the wellbore when creating said multiple radial vertical fractures.
It is yet another further object of this invention to cause multiple hydraulic fractures to communicate with a natural fracture system.
It is yet another further object of this invention to obtain increased quantities of natural resources from a formation, particularly hydrocarbonaceous fluids.
It is a still further object of this invention to locally alter in-situ stress conditions and produce multiple vertical propped permeable sequential hydraulic fractures which curve away from the wellbore in different directions.
It is still yet another object of this invention to extend multiple vertical radial fractures resultant from controlled pulse fracturing (CPF) by application of hydraulic fracturing in combination with temporary blocking agents.
BRIEF DESCRIPTION OF THE DRAWING
The drawing, FIG. 1, is a schematic representation of a wellbore in a formation wherein multiple radial vertical fractures have been generated by controlled pulse fracturing (CPF). First and second hydraulic fractures formed subsequent to the CPF treatment are illustrated to show where the second hydraulic fracture communicates with a natural fracture system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the practice of this invention, referring to the drawing, a wellbore 10 is directed vertically into formation 12. Thereafter, a controlled pulse fracturing (CPF) method is utilized to produce more than two simultaneous multiple radial vertical fractures 14, 15, and 16 which originate at wellbore 10 and penetrate formation 12.
Once the CPF treatment has been completed, hydraulic fracturing is initiated by injecting alternating slugs of a thin-fluid spacer and a temporary blocking agent containing proppant into the wellbore 10. This temporary blocking agent is either a viscous hydraulic fracturing gel or a quick-setting temporary blocking polymer, both of which are well-known to those skilled in the art of hydraulic fracturing. When the injection fluid treating pressure applied to wellbore 10 is sufficient to fracture formation 12, a first hydraulic fracture 17 is initiated from the CPF created radial vertical fracture 14 which is closest to being substantially perpendicular to the least principal horizontal in-situ stress, "σ h , min" as indicated in the drawing. The Maximum principal horizontal in-situ stress is designated in the drawing as "σ h max". Each of these principal horizontal in-situ stresses is considered to be less than the vertical in-situ stress.
While maintaining pressure in the first hydraulic fracture 17 and propagating this fracture into formation 12, alternating slugs of a thin-fluid spacer and a temporary blocking agent containing proppant therein are injected into this fracture via wellbore 10. As this first hydraulic fracture 14 propagates, the thin-fluid spacer leaks off into the permeable formation 12, leaving behind the temporary blocking agent containing said proppant so as to eventually form a propped fracture 14 that cannot accept any more fluids. Proppants and methods for packing said proppants are discussed in U.S. Pat. No. 4,109,721 issued to Slusser on Aug. 29, 1978. This patent is hereby incorporated by reference. Said proppant should be of a size sufficient to prop any resultant fractures, and be about 10 to about 40 U.S. mesh size. Sand of about this mesh size can be used. The injected fluid is then automatically diverted due to this "screen out" phenomenon to another CPF created radial vertical fracture 15. The thin-fluid spacer can comprise water, diesel oils, alcohols, high gravity crude oils, petroleum distillates, aqueous acid solutions, and mixtures thereof.
The pumping rate and hydraulic pressure are maintained in wellbore 10 and not allowed to drop thereby causing a second hydraulic fracture 18 to initiate from CPF created radial vertical fracture 15. This second hydraulic fracture 18 emanates from the tip of CPF fracture 15 since CPF fracture 15 now exhibits the least closure stress due to the interaction of blocked first hydraulic fracture 17 and the original in-situ stresses. This second hydraulic fracture 18 has a trajectory which curves away from the first hydraulic fracture 17 and is subsequently propagated perpendicular to the least principal in-situ stress σ h , min. after intersecting natural fractures 19.
As was done with the first hydraulic fracture 17, the second hydraulic fracture 18 is propagated while pumping alternating slugs of a thin-fluid spacer and temporary blocking agent with proppant therein into wellbore 10. Once the second hydraulic fracture 18 screens out, a third hydraulic fracture originates from the tip of the CPF created radial vertical fracture which has the least closure stress resulting from the interaction of stresses from the first hydraulic fracture 17, the second hydraulic fracture 18, and the original in-situ stresses. Hydraulic fracturing pressure and the pumping rate are maintained as above and another curved fracture is propagated. These steps are repeated until a desired number of propped permeable sequential hydraulic fractures are created in formation 12 via wellbore 10.
As is known to those skilled in the art, multiple radial vertical fractures can be created at the wellbore and extended into the formation without crushing the formation adjacent to the wellbore when a propellant is utilized. A propellant means for creating more than two simultaneous multiple radial vertical fractures is placed in the well or wellbore substantially near the productive interval and ignited. As is known to those skilled in the art, the pressure loading rate is the primary parameter for the production of multiple fractures. The loading rate required to produce multiple fractures is an inverse function of well-bore or hole diameter. Hot gases are formed in the wellbore or borehole upon ignition of a propellant means thereby creating a pressure capable of fracturing rock formations. A method for creating said multiple radial vertical fractures by controlled pulse fracturing (CPF) is disclosed in U.S. Pat. No. 4,548,252 which issued to Stowe et al. on Oct. 22, 1985. This patent is hereby incorporated by reference.
In this present invention, a temporary blocking agent is utilized. One method for making a suitable temporary blocking agent is discussed in U.S. Pat. No. 4,333,461 which issued to Mueller on June 8, 1982 which patent is hereby incorporated by reference. The stability and rigidity of the temporary blocking agent will depend upon the physical and chemical characteristics desired to be obtained. As is known to those skilled in the art, the temporary blocking agent should be of a stability and rigidity sufficient to withstand environmental conditions encountered in the formation. The temporary blocking agent which is utilized can comprise a solidifiable gel which breaks with about 0.5 to about 4 hours.
A hydraulic fracturing technique which can be used in the practice of this invention is disclosed by Savins in U.S. Pat. No. 4,067,389 which issued on Jan. 10, 1978. This patent is hereby incorporated by reference.
The process of this invention can be utilized in many applications. These applications include removal of desired resources from a formation containing geothermal energy, tar sands, coal, oil shale, iron ore, uranium ore, and, as is preferred, hydrocarbonaceous fluids. The steps of this invention can be practiced until a desired number of sequential hydraulic fractures have been created which fractures communicate with a natural fracture or fractures in a resource bearing formation which fractures thereby communicate with a wellbore. Once in the wellbore a desired resource can be produced to the surface.
Sareen et al. in U.S. Pat. No. 3,896,879 disclose a method for increasing the permeability of a subterranean formation penetrated by at least one well which extends from the surface of the earth into the formation. Via this method, an aqueous hydrogen peroxide solution, containing therein a stabilizing agent is injected through said well into the subterranean formation. After injection, the solution diffuses into the fractures of the formation surrounding the well. The stabilizing agent reacts with metal values in the formation which allows the hydrogen peroxide to decompose. The decomposition of hydrogen peroxide generates a gaseous medium causing additional fracturing of the formation. Sareen et al. were utilizing a method for increasing the fracture size to obtain increased removal of copper ores from a formation. This patent is hereby incorporated by reference. Utilization of the present invention will increase the communication between the wellbore and natural resources in the formation by hydraulic extension of the fractures resultant from controlled pulse fracturing (CPF).
In addition to removing ores, particularly copper ores and iron ores from a formation, the present invention can be used to recover geothermal energy more efficiently by the creation of more fracture surface area. A method for recovering geothermal energy is disclosed in U.S. Pat. No. 3,863,709 which issued to Fitch on Feb. 4, 1975. This patent is hereby incorporated by reference. Disclosed in this patent is a method and system for recovering geothermal energy from a subterranean geothermal formation having a preferred vertical fracture orientation. At least two deviated wells are provided which extend into the geothermal formation in a direction transverse to the preferred vertical fracture orientation. A plurality of vertical fractures are hydraulically formed to intersect the deviated wells. A fluid is thereafter injected via one well into the fractures to absorb heat from the geothermal formation and the heated fluid is recovered from the formation via another well.
The present invention can also be used to remove thermal energy produced during in-situ combustion of coal by the creation of additional fracture surface area. A method wherein thermal energy so produced by in-situ combustion of coal is disclosed in U.S. Pat. No. 4,019,577 which issued to Fitch et al. on Apr. 26, 1977. This patent is hereby incorporated by reference. Disclosed therein is a method for recovering thermal energy from a coal formation which has a preferred vertical fracture orientation.
Recovery of thermal energy from subterranean formations can also be used to generate steam. A method for such recovery is disclosed in U.S. Pat. No. 4,015,663 which issued to Strubhar on Apr. 5, 1977. This patent is hereby incorporated by reference.
Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims. | A process for sequentially fracturing a subterranean formation containing desired natural resources in which controlled pulse fracturing (CPF) is combined with hydraulic fracturing in the same wellbore. After multiple radial vertical fractures have been created by CPF, a solidifiable gel material is directed into the created fractures during a subsequent hydraulic fracturing procedure. During this procedure, multiple vertical hydraulic fractures initiate in and propagate away from the CPF created fractures thereby bringing the wellbore into communication with the desired natural resources. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application 61/716,123, filed Oct. 19, 2012 and to U.S. Provisional Application 61/591,111, filed Jan. 26, 2012, which are hereby incorporated by reference. The subject matter disclosed in U.S. Application Nos. 61/186,610; 61/358,282; 61/476,110; 61/476,545; 12/797,286; 13/168,367; 61/591,111; and PCT/US2010/038160 is hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] (None)
REFERENCE TO MATERIAL ON COMPACT DISK
[0003] (None)
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] DNA can be amplified from human red blood cell samples by primers designed from DNA sequences encoding a bacterial major surface protein and 16 s ribosomal RNA (16s rRNA). Primer pairs based on DNA sequences for the major surface protein 2 (MSP2) of Ehrlichia/Anaplasma can amplify DNA homologous to DNA from human chromosomes 1 and 7 from red blood cell samples. Primers based on DNA sequences encoding 16s rRNA from Anaplasma species can amplify DNA from human red blood cells, but not from nucleated white blood cells. The amplified DNA is contained in samples of red blood cells from HIV infected individuals as well as from some healthy individuals of Caucasian or African origin and represents a risk factor for HIV infection. These primers can be employed in methods for assessing risk of HIV infection by amplifying DNA from red blood cell samples.
[0006] 2. Description of the Related Art
[0007] Chronic HIV infection causes strong immune depression (AIDS) in most patients leading to lethal opportunistic infections or cancers. Specific inhibitors of HIV multiplication are currently used for treating HIV infected patients before they reach the full-blown stage of AIDS. Such inhibitors act mostly on the reverse transcriptase and protease of HIV to efficiently suppress virus multiplication and reduce virus load to a low level of less than 40 viral RNA copies per ml of blood. Treatment results in a partial recovery of the patient's immune system as evidenced by an increase of CD4 lymphocytes and reduction of or lessened severity of opportunistic infections. However, this treatment has to be given without interruption in order to prevent rebound of virus multiplication and a subsequent reduction in the numbers of CD4 lymphocytes. Rebound of viral infection is evidence of a reservoir of HIV in infected patients that is not accessible to antiviral treatment and the existence of this reservoir is generally acknowledged. In addition to a reservoir of HIV in infected patients, such patients often carry other microorganisms that are associated with HIV infection or that cause opportunistic infections.
[0008] Microorganisms associated with HIV infection that are detectable in human red blood cells, but not in human leukocytes or other kinds of nucleated human cells have not been previously characterized. The identification and characterization of microorganisms associated with HIV infection is of interest for purposes of assessing risk of HIV infection or determining the status of an HIV infected patient, for assessing risk or status of opportunistic infections, and to evaluate modes of treatment for HIV infected subjects.
BRIEF SUMMARY OF THE INVENTION
[0009] The primers designed and discovered by the inventor provide ways to pursue these objectives. Three kinds of primers have been developed and studied by the inventor.
[0010] The first kind of primer was designed based on the gene encoding the outer surface protein 2 of Ehrlichia/Anaplasma a genus of rickettsiales, which are known endosymbionts of other cells. These primers amplified DNA homologous to segments of DNA from human chromosomes 1 and 7. These primers are described in Appendix 2.
[0011] This first kind of primers were initially designed to detect DNA encoding the major surface protein 2 (MSP2) of Ehrlichia/Anaplasma species. However, neither of the two pairs of primers described by Appendix 2 (Primer Pairs 1 and 2) detected at various annealing temperatures any related microorganism in the biological samples investigated.
[0012] Surprisingly, it was discovered that this first kind of primer amplified DNA from human red blood cell samples that was highly homologous to DNA sequences on segments of human chromosomes 1 and 7. Primer Pairs 1 and 2 amplified DNA by the polymerase chain reaction (“PCR”) that was 100% homologous with human sequences when the primer sequences themselves were excluded. The amplified DNA was sequenced and the sequences aligned to sequences described for human chromosome 1 (clone RP11-332J14 GI:22024579, clone RP11-410C4 GI:17985906, and Build GRCh37.p5 Primary Assembly —) and in human chromosome 7 (PAC clone RP4-728H9 GI:3980548; human Build GRCh37.p5, and alternate assembly HuRef SCAF — 1103279188381:28934993-35424761). This was not expected since the primer pairs had been designed to detect genes encoding a bacterial MSP2 gene, not human chromosomal sequences. Furthermore, the amplification of such sequences from samples of red blood cells was in itself surprising since red blood cells lack a nucleus containing chromosomes. The ability to amplify DNA homologous to human DNA from red blood cells is evidence that the target DNA amplified by these primers is present as an extranuclear or cytoplasmic element, such as a plasmid, or is contained in or bound by a microorganism that invades or is otherwise associated with red blood cells. This DNA component may be present on a plasmid or otherwise contained in or bound to a microbe associated with red blood cells. Its presence represents a risk factor for HIV infection or progression and/or opportunistic infections.
[0013] A second kind of primer was designed based on the sequences homologous to human chromosomes 1 and 7 that were amplified by the first kind of primers (MSP2 primers). This kind of primer is useful for identifying the target DNA homologous to human chromosomes 1 and 7 in a sample, such as a red blood cell sample. Such primers, including the first type of MSP2 primers, are used to detect risks of HIV infection, HIV progression, risks of opportunistic infections, disease prognosis and response to drug treatment in subjects where the presence of DNA homologous to segments human chromosomes 1 and 7 is a risk factor. This kind of primer is exemplified in Appendix 3.
[0014] A third type of primer was developed based on the genes from Anaplasma species encoding 16s rRNA. Anaplasma is a genus of rickettsiales. This type of primer was found to amplify a sequence of 700 bp of ribosomal DNA that was about 85% identical to the corresponding genetic regions of Rickettsia and about 99% identical to the corresponding genetic regions of Acinetobacter genus. Acinetobacter is a genus of gram negative bacteria within the class of gammaproteobacteria. The homology of amplified 16s rDNA with Acinetobacter DNA may be coincidental because DNA can be amplified from biological samples that pass through a 450 nM filter unlike classical Acinetobacteria.
[0015] These primers identify a bacterial agent associated with red blood cells that is related to but not identical to known Rickettsia species. This bacterial agent has been identified in red blood cells of not only HIV infected patients but also in some healthy individuals of Caucasian or African origin. This third type of primer is used to detect risks of HIV infection, HIV progression, risks of opportunistic infections, disease prognosis and response to drug treatment in subjects where the presence of a target containing the amplifiable 16s rRNA or 16s rDNA is a risk factor. These primers are described in Appendix 4.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1(A) and 1(B) were produced on different dates. Lane numbers 1 and 2 are duplicates (from HIV-negative source) and lanes 3 and 4 are duplicates (from HIV-positive source). All DNA samples were extracted from a third passage HL60 cells exposed to an agent originating from red blood cells of HIV-negative or HIV-positive patients. These panels represent gel electrophoresis pictures of amplicons obtained by 70 cycles of PCR using primers derived from the Ehrlichia MSP2 gene (213 bp) and primers derived from the 16s ribosomal gene of Anaplasma (690 bp). The bands on the left sides of FIGS. 1(A) and 1(B) show the 213 bp fragment mapped to human chromosome 7 amplified by the Ehrlichia MSP2 primers. The bands on the right sides of FIGS. 1(A) and 1(B) show the 690 bp fragment amplified by the Anaplasma primers (SEQ ID NOS: 24 and 25).
DETAILED DESCRIPTION OF THE INVENTION
[0017] Amplification of DNA from biological samples, including blood, plasma, and serum samples or samples obtained from cell culture can be performed using PCR or other nucleic amplification methods known in the art. These methods can be used to amplify or detect target DNA qualitatively or quantitatively to provide a “yes or no” determination of the presence of the target sequence or to quantitatively detect an amount of DNA amplified under controlled conditions.
[0018] The DNA amplified by the first and second kinds of primers is higher frequency in red blood cells obtained from patients infected with human immunodeficiency virus compared to healthy individuals. This is especially the case for patients who have undergone or are undergoing antiretroviral therapy. The quantity of DNA amplified by these primers is reduced after long-term treatment of a patient with antibiotics and the primers were found not to amplify DNA from white blood cells or from other human cell lines. DNA has also been amplified from the red blood cells of healthy African subjects not infected with HIV using these primers. These results suggest the amplified DNA is derived from an antibiotic sensitive microorganism associated with red blood cells.
[0019] Despite the apparent human origin of this DNA, the data herein show that the amplified sequences are associated with a transmissible agent and that the transmissible agent is closely associated with human immunodeficiency virus as explained below.
[0020] These sequences were easily detected in the DNA of anucleated red blood cells (RBCs) in 100% (35 out of 35 subjects) HIV-infected African and Caucasian patients and they could not be detected in the DNA of nucleated cells including in the white blood cell fraction of the same patients, nor in human DNA from cultured human cells.
[0021] These sequences were rarely detected in the red blood cell fraction of healthy African subjects and none were detected in the red blood cells of the healthy Caucasians tested.
[0022] Long term antibiotic treatment (e.g., with doxycycline or azithromycin) of HIV-positive patients for more than three months was found to decrease the intensity of the bands amplified using these primers suggesting that these bands are induced, generated or otherwise originate from an antibiotic sensitive microorganism.
[0023] Amplification of DNA from a supernatant of a short term culture of human cell line HL60 with an extract of RBC from an HIV-positive patient prepared by freeze-thawing RBC and then by removing heavy components by a low speed (10 mins at 1,500 g) centrifugation produced strong DNA bands. The intensity of these bands suggests growth and multiplication of a microorganism that contains DNA amplified by Primer Pairs 1 and 2.
[0024] To further explore this effect, new primers were designed that allow amplification of regions of human genomic DNA adjacent to or including those amplified by Primer Pairs 1 and 2. These new primers include:
[0025] primers “hChr1/14179308 S” upstream of, and “hChr1/14179853 AS” encompassing one end of the 237 bp amplicon related to chromosome 1 (546-bp long amplicon);
[0026] primers “hChr7/4292976 S” upstream of, and “hChr7/4294619 AS” downstream of the 213 bp amplicon related to chromosome 7 (1,643-bp long amplicon); and the primers described by Appendix 3.
[0027] These primers amplify DNA not only from the components of RBCs of HIV infected Caucasian or African patients, but also from the components of RBCs of healthy African subjects. However, these DNAs are lacking in all or most of HIV-negative Caucasian subjects. These sequences are amplified after antibiotic treatment of their carrier subjects indicating that the agent generating them is insensitive to antibiotic treatment. As in the case of the MSP2 primers-amplified sequences, these kinds of primer pairs amplify DNA present in or associated with anucleated RBC and not in white blood cells or human cell lines. It is possible that such a microorganism identified with these primers differs from the carrier of the initial short DNA sequences and will amplify or cause amplification of human genomic DNA sequences in an integrated or unintegrated manner. The primers disclosed herein permit the design of diagnostic tests and treatments aimed at reducing the risk of HIV infection in important segments of the human population in which this agent appears and can be detected by amplification of these DNA sequences.
[0028] The third kind of primers that identify a previously unknown bacterial agent that is associated with human red blood cells and related to, but not identical to, known Rickettsia species are provided. These primers are derived from the 16S ribosomal DNA sequences of an Anaplasma species and amplify a sequence of 700 bp of ribosomal DNA that is about 89% identical to the corresponding regions of the genome of Rickettsia . This sequence is about 99% identical to the corresponding regions of Acinetobacter genus DNA. Besides the primers exemplified herein, other primers that amplify the same 700 bp of ribosomal DNA or detectable fragments of this sequences may be designed based on this nucleotide sequence. These primers may amplify 20, 30, 50, 100, 200, 300, 400, 500, 600 or 700 nucleotides of this sequence. They may comprise short portions (e.g., 18-30 bp) of the 700 bp sequence and can be designed based on methods well known in the molecular biological arts. The table below depicts the various kinds of primers.
[0000]
Primers designed
Primers were designed to
based on
include a conserved 16S
rickettsiales16S
region of DNA which
ribosomal DNA
recognizes Rickettsiales
Appendix 1
gene
SEQ ID NO:
and also Propionobacter.
5′-GCAAC
1
Rick16S 929S (20 mer)
GCGAA AAACC
Tm = 45.0° C.
TTACC
5′-GACGG
2
Rick16S 1373AS (18 mer)
GCAGT GTGTA
Tm = 45.0° C.
CAA
Appendix 2
MSP2 Primers
MSP2 primer
5′ GCCTA
3
18 mer
pair 1
CAGAT TAAAG
GCT
5′ ATCAT
4
20-mer
ARTCA CCATC
ACCTA
MSP2 primer
5′ CYTAC
5
17-mer
pair 2
AGAGT GAAGG
CT
5′ ATCAT
6
20-mer
ARTCA CCATC
ACCTA
Appendix 3
Human chromosome 1 and 7 primers
Chromosome 1 primers
SEQ ID NO:
*primer #1
5′-CCT TAC
7
hChr1/14179308 S
ACT CAG CCA
GAC AT
*primer #2
5′-CCA GGT
8
hChr1/14179853 AS
GTG TGG CTT
ATA CA
primer #3
5′-CAT AGC
9
hChr1/14180006 S
TTC CTA GTA
AGT AGA CCA G
primer #4
5′-AGG GGA
10
hChr1/14180401 AS
GTC TGA GAT
GGT
primer #5
5′-ACT GGA
11
hChr1/14181093 AS
GAG GTG GAG
GTT
primer #6
5′-GGT AAT
12
hChr1/14181390 AS
TCC TAT GTG
CGA GGT
primer #7
5′-TCA AAA
13
hChr1/14177990 S
GAC AGT GGT
GAC TCT
primer #8
5′-ATG TCT
14
hChr1/14179327 AS
GGC TGA GTG
TAA GG
Chromosome 7 primers
SEQ ID NO:
primer #1
5′-ATG TAG
15
hChr7/4292976 S
TTG AGC AGT
TTT GAA TGA
primer #2
5′-TCC TGC
16
hChr7/4293490 S
CTT AGT GAG
GAT CT
primer #3
5′-ATG AAT
17
hChr7/4293941 AS
AGG TGA TGG
TGA TGA CT
primer #4
5′-CCG TCA
18
hChr7/4294102 S
TTT AAG CCT
TTA ATC TCA
primer #5
5′-GTA GTC
19
hChr7/4294619 AS
TTT TGG CAT
CTC TTT GTA
primer #6
5′-CAG CCT
20
hChr7/4294983 AS
GGA GAA CAG
AGT G
primer #7
5′-GAT CTA
21
hChr7/4295251 AS
GCA GTT CAT
AGG AAG GAA
primer #8
5′-GGC TGA
22
hChr7/4291579 S
AAC AAT GGG
GTT TT
primer #9
5′-TTT AGT
23
hChr7/4293175 AS
AGA CCC CTC
GAC CA
Appendix 4: Anaplasma 16s rDNA based primers
SEQ ID NO:
Primer
5′-CTG ACG
24
sense
ACA GCC ATG
CA
Primer
5′-GCA GTG
25
antisense
GGG AAT ATT
GGA CA
[0029] Specific embodiments of the invention include, but are not limited to those described below.
[0030] An agent that is associated with red blood cells, especially mature anucleated red blood cells, that passes through a 0.45 micron filter. This agent may be sensitive or insensitive to a particular antibiotic. Agents sensitive to azithromycin or to a cyclin antibiotic have been identified. This agent contains, induces, excises, or otherwise provides DNA that is amplified by (i) primer pairs 1 (SEQ ID NOS: 3 and 4) or 2 (SEQ ID NOS: 5 and 6), (ii) a pair of primers described by Appendix 3 (SEQ ID NOS: 7-14 or SEQ ID NOS: 15-23), (iii), the pair of primers described in Appendix 4 (SEQ ID NOS: 24 and 25); or a pair primers that amplify at least fifteen, twenty, twenty five, thirty, forty, fifty or more consecutive nucleotides of the same DNA as is amplified by the specific primers described herein.
[0031] The amplified DNA may be 80%, 85%, 90%, 95%, 99%, up to and including 100% identical or similar to human DNA, wherein sequence identity is determined by BLASTn using the default setting. Preferred parameters for determining the “nucleotide identity” when using the BLASTN program (Altschul, S. et al., Journal of Molecular Biology 215 (1990), pages 403-410) are: Expect Threshold: 10; Word size: 28; Match Score: 1; Mismatch Score: −2; Gap costs: Linear.
[0032] An agent that is associated with red blood cells, passes through a 0.45 micron filter, may be sensitive or insensitive to a particular antibiotic, can be detectable in red blood cells of an HIV patient, but not detectable in the white blood cells of said patient. Such an agent may become detectable in the red blood cells of an HIV-infected patient within the first year after HIV infection or after initiation of anti-retroviral treatment. Such an agent may appear or be associated with the red blood cells of an African subject or European subject who is HIV-negative.
[0033] The agent may be a microorganism, such as a bacterium, or a specific kind of bacterium such as Rickettsia or Rickettsia -like bacteria, Ehrlichia or Anaplasma or a component thereof. Such an agent may contain a plasmid, episome, or extra chromosomal element comprising human chromosomal DNA that is amplified by MPS2 gene primers; or that is contained in or associated with a red blood cell that contains a plasmid or extra chromosomal element comprising human chromosomal DNA that is amplified by MPS2 gene primers.
[0034] Isolated red blood cells may contain the agent as described herein as well as disrupted or lysed red blood cells, such as a supernatant produced by freezing and thawing red blood cells after removing white blood cells and then removing material that pellets by a low speed centrifugation, e.g., for 10 mins at 1,500 g. The red blood cells associated with the agent are detected by amplifying DNA from them using (i) primer pairs 1 (SEQ ID NOS: 3 and 4) or 2 (SEQ ID NOS: 5 and 6), (ii) a pair of primers described by Appendix 3 (SEQ ID NOS: 7-14 or SEQ ID NOS: 15-23), (iii), the pair of primers described in Appendix 4 (SEQ ID NOS: 24 and 25); or a pair primers that amplify at least fifteen, twenty, twenty five, thirty, forty, fifty or more consecutive nucleotides of the same DNA as is amplified by the specific primers described herein.
[0035] Another aspect of the invention is the DNA amplified from the agent or from red blood cells associated with the agent. This DNA is can be produced using the primer pairs described herein. The DNA that is present in a red blood cell may be from an infectious or replicating agent per se, from a component of an infectious organism present in the anucleated red blood cell, or from DNA that results from exposure of the red blood cell or its precursor cells to an infectious or replicating agent.
[0036] The amplified DNA from a red blood cell may comprise portions of human chromosome 1 or 7 including the sequences described in Appendix 5 or Appendix 6 or fragments of these sequences comprising 10, 20, 30, 40, 50, 100, 200 or more consecutive nucleotides of these sequences.
[0037] The DNA according to the invention may be contained or inserted into a vector, such as a plasmid or phage vector containing the isolated or purified amplified DNA. A host cell can be transformed with the isolated or purified amplified DNA from the agent or from red blood cells associated with the agent.
[0038] The invention is also directed to a method for detecting an agent as described herein comprising contacting material from anucleated red blood cells of a subject with primer Pair 1, primer Pair 2, or a pair of primers selected from the group consisting of those described in Appendix 3 under conditions suitable for amplification of DNA by said primers, and detecting said agent when amplified DNA is detected.
[0039] The primers used in this method may be selected from the group consisting of (i) primer pairs 1 (SEQ ID NOS: 3 and 4) or 2 (SEQ ID NOS: 5 and 6), or (ii) a pair of primers described by Appendix 3 (SEQ ID NOS: 7-14 or SEQ ID NOS: 15-23) or a pair primers that amplify at least fifteen, twenty, twenty five, thirty, forty, fifty or more consecutive nucleotides of the same DNA as is amplified by the specific primers described herein. Alternatively, a set of primers that amplify the same DNA fragment amplified by the two primers described above may be employed. These primers may be designed by methods known in the art and each may comprise 18-30 or more base pairs of the sequence amplified by the primers above.
[0040] A method for detecting an agent as described herein comprising: contacting under conditions suitable for amplification of target DNA material from red blood cells of a subject with a primer and detecting or recovering the amplified DNA, where the primers are described by Appendix 4:
[0000]
Primer (sense)
(SEQ ID NO: 24)
5′-CTG ACG ACA GCC ATG CA
Primer (antisense)
(SEQ ID NO: 25)
5′-GCA GTG GGG AAT ATT GGA CA.
[0041] Alternatively, a set of primers that amplify the same DNA fragment amplified by the two primers described above may be employed. These primers may be designed by methods known in the art and each may comprise 18-30 or more base pairs of the sequence amplified by the two primers above.
[0042] The biological sample used in the method described above or other methods described herein may be whole blood or a cellular component of whole blood, isolated anucleated red blood cells, isolated red blood cell precursors, such as erythroblasts, bone marrow or spleen cells, or subcellular fractions thereof, such as cellular lysates, supernatants or solid materials. Blood plasma or serum or other bodily fluids or tissues may also be used as a biological sample for the methods described herein. Those of skill in the art can select an appropriate biological sample for performance of PCR or select the appropriate conditions for producing an EMS signalized sample based on the disclosures of the patent applications incorporated by reference above. Representative biological samples include whole blood, isolated RBCs, subcellular components, extracts, or lysates of RBCs or their precursor cells, blood plasma or blood serum, spinal fluid, mucosal secretions, urine, saliva, bone marrow, or tissues.
[0043] A method for treating or for reducing the severity of a disease, disorder, or condition associated with the agent comprising treating a patient with an agent that reduces the titer of said agent or that reduces the amount of DNA amplified from a cell associated with it. This method may also comprise treating the patient with one or more antibiotics, such as azithromycin or a cyclin antibiotic; with one or more synthetic or natural immunostimulants, active vaccines, passive vaccines, antioxidants or antibiotics. A patient may also undergo treatment sequentially or simultaneously for viruses or other microorganisms or agents capable of causing an immunodeficient disease, disorder or condition. Treatment may be therapeutic or prophylactic and can include the administration of one or more anti-retroviral drugs or other antiretroviral treatments. The patient may be currently undergoing antiretroviral therapy or therapy to eradicate human immunodeficiency virus infection and treatment for the coinfecting bacterium initiated. Other modes of or supplemental treatments include treating the patient with one or more natural immunostimulants, antioxidants or antibiotics. The methods described herein may employ samples from subjects or patients of different geographic origins or racial or genetic backgrounds. A subject or patient may be HIV-negative, recently (e.g., less than one year) HIV-positive, a patient who has been HIV-position for more than one or two years, an HIV-positive patient who has undergone or is undergoing anti-retroviral treatments or other kinds of patients who are HIV-positive such as those with AIDS or subjects at risk of becoming HIV-positive, developing AIDS or opportunistic infections. Patients may be of African origin or may have lived in Africa and exposed to biological and environmental agents there. Similarly, a patient may be of European or Caucasian origin or may have lived in Europe or America and exposed to biological and environmental agents there.
[0044] The invention is also directed to a method for treating a disease, disorder or condition associated with an agent described herein comprising contacting red blood cells with a substance that reduces the amount of DNA amplified from a red blood cell using (i) Primer Pairs 1 or 2, (ii) primers described by Appendix 3, (iii) or the primers described in Appendix 4 or primer pairs that amplify at least 20 consecutive nucleotides of the amplicons amplified by the primer pairs described above. Such a method for treating a disease, disorder or condition associated with an agent described herein may comprise contacting red blood cells of a subject with a substance that reduces the transmission of said agent to the red blood cell; may comprise replacing the red blood cells in a subject with red blood cells that are not associated with said agent or by stimulating the development of new red blood cells in said subject; or may comprise treating blood or red blood cells with an agent that that degrades, crosslinks or otherwise interferes or inactivates nucleic acids inside of or associated with a red blood cell.
[0045] Another aspect of the invention is a method for screening blood for red blood cells from which DNA can be amplified using (i) primer pairs 1 (SEQ ID NOS: 3 and 4) or 2 (SEQ ID NOS: 5 and 6), (ii) a pair of primers described by Appendix 3 (SEQ ID NOS: 7-14 or SEQ ID NOS: 15-23), (iii), the pair of primers described in Appendix 4 (SEQ ID NOS: 24 and 25); or a pair primers that amplify at least fifteen, twenty, twenty five, thirty, forty, fifty or more consecutive nucleotides of the same DNA as is amplified by the specific primers described herein. This method comprises contacting a sample of blood or red blood cells with these pairs of primers and detecting amplified DNA and selecting a blood sample from which DNA was amplified or alternatively selecting a blood sample from which no DNA was amplified. For example, a blood sample from which amplified DNA is detected may be further evaluated or cultured to determine the sensitivity of the red blood cells or the agent associated with them to antibiotic or other therapeutic treatments. Alternatively, a blood sample in from which no DNA is amplified may be assessed as being free of the agent associated with the DNA amplified by these primers.
Example 1
Detection of Amplified DNA in Red Blood Cells
[0046] Separation of Red Blood Cells
[0047] Standard procedures for separating RBCs from buffy coat and other peripheral blood components are known. Peripheral blood was processed on a Ficoll gradient to separate the buffy coat from red blood cells. After such separation it was found that DNA extracted from buffy coat cells was completely negative as determined by PCR using the primers described above while the same primers amplified DNA in the fraction containing the separated red blood cells. While it cannot ruled out that the agent detected is externally associated with the red blood cell membranes, it was found that amplified DNA was only detected in a supernatant prepared by a low speed (1,500 g×10 mins) centrifugation to remove the heavy components of a red blood cell lysate. This lysate was prepared by repeated freeze-thawing of red blood cells isolated from the buffy coat, strong shaking by vortex, and a low speed centrifugation (1,500 g×10 mins). A pellet and supernatant fraction were obtained and tested. The primers described above only amplified DNA in the supernatant fraction, but not in the pellet.
[0048] Growth on HL-60 Cells
[0049] HL-60 cells are an ATCC cell line of promyelocytic origin. Samples of HL-60 cells at a density of 5×10 5 cells per ml in RPMI medium supplemented with 10% fetal calf serum were inoculated with the supernatant of the red blood cell lysate described above. This lysate was obtained from the red blood cells of HIV-positive patients after freezing, thawing and vortexing as previously described. After culturing for 3 days at 37° C. the low speed (1,500 g×10 mins) supernatants of the cultures were tested by PCR for DNA amplified using Primer Pairs 1 and 2. DNA was amplified from all of these cultures up to a dilution of 10 4 . The same results were obtained from culture supernatant that was passaged through a 0.45 micron filter.
[0050] Effects of Long-Term Antibiotic Treatment
[0051] Five HIV-positive patients were maintained on their antiretroviral therapy, but received for at least three months a daily antibiotic treatment (azithromycin 250 mg/day or doxycycline 100 mg/day). Blood samples were fractionated to recover a red blood cell fraction on day 0 and after 3 months of antibiotic. Results indicated that the amount of DNA amplified after 3 months of antibiotic treatment was significantly less than that amplified under the same conditions from the samples obtained on day 0.
[0052] Detection of Amplified DNA in Red Blood Cells of African and Caucasian Patients
[0053] Blood samples were obtained from African and European Patients who were HIV-negative or HIV-positive. Red blood cells were isolated from buffy coat and other blood components by separation on a Ficoll gradient as described above. Table 1 shows the results of amplification of red blood cell samples from these patients using Primer Pairs 1 and 2. Similar results were obtained using the primers described in Appendix 3. No DNA was amplified using Primer Pairs 3 and 4 for Chromosome 1 and 7 from the red blood cells of one European patient who was HIV-positive for a year or less. This suggests that in some Caucasians that the accumulation of this human DNA in the red blood cell fraction occurs late after infection and possibly under the selective pressure of antiretroviral treatment. However, amplified DNA was detected in this patient using the Primer Pairs 1 and 2 shown in Appendix 2, but the amplified DNA bands were weaker than those for chronically-infected HIV-positive patients.
[0000]
TABLE 1
Caucasian
Cultured cells (HL 60)
RBC from
HL 60 +
African
HIV+
RBC
RBC from
treated
extract
HIV+
with
from
treated
antibiotics
HIV+
with
for 3 mos
subject
RBC:
RBC:
WBC:
antibiotics
RBC:
RBC:
WBC:
(0 vs 3
No
(0 vs 3
HIV neg
HIV+
HIV+
for 3 mos
HIV neg
HIV+
HIV+
mos)
extract
days)
App. 2
Pair 1
rare
100%
0%
↓
0%
100%
0%
↓
−
↑
Pair 2
rare
100%
0%
↓
0%
100%
0%
↓
−
↑
Chr 1
Pair 1
+
+
−
+
−
+ or − *
−
+
−
Chr 7
Pair 1
+
+
−
+
−
+ or − *
−
+
−
+ in chronically infected and treated patients
− in recently infected patients
DNA Amplified Using Primer Pairs 1 and 2
[0054] MSP2 Primer Pairs 1 and 2 were used to perform PCR on red blood cells of HIV-positive subjects are removal of white blood cells and other blood components by Ficoll gradient separation. Primer Pairs 1 and 2 are shown below.
[0000]
Primer Pair 1
5′ GCCTA CAGAT TAAAG GCT
18 mer
5′ ATCAT ARTCA CCATC ACCTA
20 mer
Primer Pair 2:
5′ CYTAC AGAGT GAAGG CT
17 mer
5′ ATCAT ARTCA CCATC ACCTA
20 mer.
[0055] The DNA bands amplified by PCR using Primer Pairs 1 and 2 were 100% homologous with human sequences (primer sequences excluded) present in data-banks for human genomic sequences, respectively in human chromosome 1 (clone RP11-332J14 GI:22024579, clone RP11-410C4 GI:17985906, and Build GRCh37.p5 Primary Assembly—) and in human chromosome 7 (PAC clone RP4-728H9 GI:3980548; human Build GRCh37.p5, and alternate assembly HuRef SCAF — 1103279188381:28934993-35424761).
[0056] Human chromosome 1 and 7 DNA Sequences Described in Appendix 5
[0057] Appendix 5 shows the identities of human chromosome 1 and Chromosome 7 sequences that are amplified by primers described in Appendix 3. Primer sequences are underlined.
[0058] Primer Pair 3:
[0059] Primer “hChrl/14179308 S” upstream of, and “hChr1/14179853 AS” encompassing one end of the 237 bp amplicon related to chromosome 1 (546-bp long amplicon) were used to perform PCR on material from red blood cells isolated from other blood components by Ficoll gradient.
[0060] Primer Pair 4:
[0061] Primers “hChr7/4292976 S” upstream of, and “hChr7/4294619 AS” downstream of the 213 bp amplicon related to chromosome 7 (1,643-bp long amplicon); and the primers described by Appendix 3.
Example 2
Method for Detecting Risk of Acquiring HIV Infection or Opportunistic Infection Associated with HIV Infection or Risk of the Progression of an HIV Infection or Opportunistic Infection
[0062] Blood is collected from a subject in the presence of EDTA as an anticoagulant. The red blood cells in the sample are separated from buffy coat and plasma components of blood using a Ficoll-Hypaque gradient according to the manufacturer's current protocol. DNA in the red blood cell sample is prepared and amplified using a QIAGEN® Fast Cycling PCR Kit or Taq PCR Core Kit (as described in the current QIAGEN® product catalog) using MSP2 primer pair 1: 5′ GCCTA CAGAT TAAAG GCT (SEQ ID NO: 3) and 5′ ATCAT ARTCA CCATC ACCTA (SEQ ID NO: 4) or MSP2 primer pair 2: 5′ CYTAC AGAGT GAAGG CT (SEQ ID NO: 5)+5′ ATCAT ARTCA CCATC ACCTA (SEQ ID NO: 6).
[0063] Amplified DNA is resolved by gel electrophoresis and detected by staining with ethidium bromide.
[0064] A subject is classified as being at a higher risk for acquiring HIV or HIV-associated opportunistic infection or for when amplified DNA is detected.
Example 3
Method for Detecting Microorganism Associated with Risk or Progression of HIV Infection or Opportunistic Infection Associated with Infection with HIV
[0065] Blood is collected from a subject in the presence of EDTA as an anticoagulant. The red blood cells in the sample are separated from buffy coat and plasma components of blood using a Ficoll-Hypaque gradient according to the manufacturer's current protocol. DNA in the red blood cell sample is prepared and amplified using a QIAGEN® Fast Cycling PCR Kit or Taq PCR Core Kit (as described in the current QIAGEN® product catalog) using the primer pair 5′-CTG ACG ACA GCC ATG CA (SEQ ID NO: 24)+5′-GCA GTG GGG AAT ATT GGA CA (SEQ ID NO: 25).
[0066] Amplified DNA is resolved by gel electrophoresis and detected by staining with ethidium bromide.
[0067] A subject is identified as being infected with a microorganism when amplified DNA is detected.
APPENDIX 5
[0068] The human chromosome 1 sequence amplified by the MSP2 primers shown below:
[0000] primer identifiers sequences MSP2 primer #3) Ac/mMSP2-1019S 5′-CYTACAGAGTGAAGGCT where 7 = T or C MSP2 primer #5) Ac/mKSP2-1128AS 5′-ATCATARTCACCATCACCTA where R = G or A Sequence of the 237 bp amplicon generated with these two primers by PCR: 5′- ATCATAGTCACCATCACCTA CCAGCTGTATAAGCCACACACCTGGGAGTCCTCCTAGCCTTTTTCCTCCTCCTCTCATC CTCCATATCCCATTGACCGTCAGGGCCTACTGAGTCTACACTCCAATTTTCTTTTAAATCTATCCCCACTGCCACTGTCCTA GTCTAAGGCAATACCATCTGGTCACCCAGATCATTCCATAGCTTCCTAGTAAGTAGACC AGCCTTCACTCTGTAAG -3′ underlined nucleotides: primer sequences bold nuleotides: divergent nuleotides between MSP2 primers and the corresponding homologous human Chr 1 sequence.
The human chromosome 7 sequence amplified by the MSP2 primers shown below:
[0000] primer indentifiers sequences MSP2 primer #2) AphMSP2-1019S 5′-GCCTACAGATTAAAGGCT MSP2 primer #5) Ac/mMSP2-1128AS 5′-ATCATARTCACCATCACCTA where R = G or A (same as above) Sequence of the 213 by amplinon generated with these two primers by PCR : 5′- GCCTACAGATTAAAGGCT TAAATGACGGTGAAAACTTAGTATTCTTTGGGTGGACAATAGTGAAATTTGC ACTTTGGACAGAATGACATGTACAAAAAGAGTCAAGAAACTTTTTAATCTATTTAAAGGACTCAAAGTAATTT GTGAAGGCCATAGCGTAAAAATAACTTCAGTGGATGGAATGGGATGATGAA TAGGTGATGGTGACTATGAT -3′ underlined nucleotidese: primer sequences bold nucleotides : divergent nucleotides between MSP2 primers and the corresponding homologous human Chr 7 sequence.
Identities of the human sequences amplified by the human chromosome 1 primers or human chromosome 7 primers described in sections A) and B) respectively below.
The sequences described below, except for the primers and MSP2-derived amplicons, are corresponding to human genomic sequences available in NCBI genome databanks (www.ncbi.nlm.nih.gov/projects/genome).
[0000] A) Genomic human Chromosome 1 primers #1 (hChr1/14179308 S) and #2 (hChr1/14179853 AS) PCR-Smplified 546 by amplicon : identifier: Amplicon hChr1/14179308-14179853 5′- CCTTACACTCAGCCAGACAT ATATTTGTGTTTGTTATCCATGTGCACAGAGACTTTGGCATTCTGGGTGAGGAAGAAAGAAGAGAATATACATGGAAACCCAGGGGTAAGAGAAAAGGACAACAGAGAATGT GGCATGGGGAATGCTCTGCTGGGTCACATTGAATGGTTCTGAACCACTGTGGAAAAAAAGGAGTTAGAAAGAATCAGATGCCGAAGGAGCCAATTTTCACAATACTCCGAGACTCAGGGCAAAAGCAGCCTTGTTCTA GTAGCCTATGGGTAAAAGAAGACACAGAACTGAGGGGAGGACTTTTCCCCTGAGTCCACCACAAACCGCCATGGAGCTGAGGCAGCCTGAAGTCTCAGGGGCATGGGAGGGATTTGCCTTTTGGATTTCTCCAATGGG ATGTCTTACAGGCACTTCATATTTAGCAGATCCAAAACTTAACTCAGATACTCCTCTTGCCATATCTGTTCCTCTTGCTGTGTTCCTGACCATGATTATCACCATCACCTACCAGC TGTATAAGCCACACACCTGG -3′ underlined nucleotides: hChrl genomic primer sequences bold nucleotides: homologous extremity of the 237 bp amplicon obtained with the primers MSP2#3-5. B) Genomic human Chromosome 7 primere #1 (hChr7/4292976 S) and #5 (hChr7/4294619 AS) PCR-amplified 1,644 by amplicon*: identifier: Amplicon hChr7/4292976-4294619 5′- ATGTAGTTGAGCAGTTTTGAATGA GTTTCTTAATCCTGAGTTCTAGTTTAAGAAAATATTAAAAATAAAAAATTATGTCACCAACTAAATTTTTACTGCAGATAATCATAAGTTGGTTAGATTGGACCTTCATT GTGAAATGCAGTAACTTTGGTTTAAGCAATATCCAAAACCAGAAATTGGTCGAGGGGTCTACTAAATTCCGTTTTCTTTTGTTCTAAACAATTAAACATTCTAAAATTTAGGGAAAAGGACCAATGGTGCAAACATTT TAGAGCTGACAGTTGTGTGCCATATGCCATGATTCTGTTACAAATGAACAGTATTCAGATTCAAAATCAGTGTAAACACTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTATTTTACACAGCCATTTA AATATTAACCGCCTTTGAGTATTAGGGGAAAAAACAGAAACTAAAAGCGAATATATTTGTTTCCTGAATCCTCCCACCAAACCACTTTTTAAATTAATTATATT TCCTGCCTTAGTGAGGATC TTCCTATTCATCAAA GATAAAATACCAAATATAATTTACTCTCCTTCTCTACCTCACCCCCAATATTCAACAATTCCCTATTTTATTTTGATTTTACTTCCTATTGTCTCTCAGTGCATCCTTACTACTGGTTTCTGGCCTCAATGTCTCTTT CCATAAATACTTCCTCCAGGGCTTCAGCAGTGTATATTGCAATCCATGAGTGTGATGCCCTTATAAGCTGTACAGGCACAACCCAGGCAAACATACACAATGACCATAATCATAACAGTCATTACTGGTGCCTTTACT TCATCATCCCATTCCATCCACTGAAGTTATTTTACGCTATGGCCTTCACAAATTACTTTGAGTCCTTTAAATAGATTAAAAAGTTTCTTGACTCTTTTTGTACATGTCATTCTGTCCAAAGTGCAAATTTCACTATTG TCCACCCAAAGAATACTAAGTTTTCACCGTCATTTAAGCCTTTAATCTCAGGATCTCACAATAAATACAATCACTCTTTCCTATATGCCTAATCTTCTGCTTGAGCATAATTTTAATGTGCTAACTATTCTGTAATTA TATATATATTTTTAATTCAGCCACTTCTCTCACTAGAAAGTGAGTTTGTTGAAATCAGGGTAAGTATATTTTATGTTTGGATGAATTCCCCATCACAATACTTCACATGTAGTTATCTAGTCACCAATTTTTATTGAA ATTAATTGTACATATAATAAAACTTTAATATAAAATGTTTCTCTTGAGGGGAGATTTTCTTTGTAAAACTATCCTTCTGAGCTTTGTGATGTGATGATTGTCTAATGTCTGTTGCAAGATTAAGGAAAATGTATTTGA ATGCAAATGAACTTACACTGTCATACCAAAAGTGTGATAATTTCTTGCTCCTGAACTCACTCTCCCTACCTGCCTATTAAAATCAGAATACACAGATCTGTATCTG TACAAAGAGATGCCAAAAGACTAC -3′ underlined nucleotides: hChr7 genomic primer sequences bold nucleotideS: homologous sequence of the 213 bp amplicon obtained with the primers MS2P2#2-5. The internal underlined nucleotides correspond to the sequence of primer hChr7/4293490 S (hChr7#2). *please note that this amplime lenght bas been reported as 1,643 bp long in previous documents. The correct lenght is 1,644 bp.
Other amplicons obtained from HIV positive or HIV-negative patients or from both using the human chromosome 1 or human chromosome 7 primers described in sections C) and D) below.
[0000] C) Genomic human Chromosome 1 primers #3 (hChr1/14180401 AS) and #4 (hChr1/14180401 AS) PCR-amplified 396 bp amplicon: Identifier: Amplicon hChr1/14180006-14180401 5′- CATAGCTTCCTAGTAAGTAGACCAG CCTTCAGTCTGAGCCCTCCTCGGTCCTTCCTCCCCAGTGCTGCTGGAGTAATCCTTCTAACACAACAATGAAAGCAGGTCACTGCGGCTCAAATGATGTCAGCGGCTTT ATCATCCATGTTGCCTGGCTTTTCACAGGCATGTCTTGCAGTGCAGCCTTATAACTCTCTCAACACAACTCTGTATCCTCCTCATTCTTCATGCTTTTATAATGTCAAGCCATGTGACACTCCCTAAATATACCATGT TTTCTCTTTTTCCTCCTCCCCCTCTCTCATTTGCAGCTTCCCATACTTATCTTCCTAAACACTACTCTTTTGAAATGTTTATTTCAAGGGTTTCTTATCTTTTAA ACCATCTCAGACTCCCCT -3′ underlined nucleotide: primer sequences bold nucleotides: homologous extremity of the 237 bp amplicon obtained with the primers MSP2#3-5. D) Genomic human Chromosome 1 primers #3(hChr1/14180006 S) and #5 (hChr1/14101093 AS) PCR-amplified 1,088 bp amplicon: Identifier: Amplicon hChr1/14180006-14181093 5′- CATAGCTTCCTAGTAAGTAGACCAG CCTTCAGTCTGAGCCCTCCTCGGTCCTTCCTCCCCAGTGCTGCTGGAGTAATCCTTCTAACACAACAATGAAAGCAGGTCACTGCGGCTCAAATGATGTCAGCGGCTTT ATCATCCATGTTGCCTGGCTTTTCACAGGCATGTCTTGCAGTGCAGCCTTATAACTCTCTCAACACAACTCTGTATCCTCCTCATTCTTCATGCTTTTATAATGTCAAGCCATGTGACACTCCCTAAATATACCATGT TTTCTCTTTTTCCTCCTCCCCCTCTCTCATTTGCAGCTTCCCATACTTATCTTCCTAAACACTACTCTTTTTGAAATGTTTATTTCAAGGGTTTCTTATCTTTTAA ACCATCTCAGACTCCCCT GGGGATTACCCCTT TTCCTATGTTTTTATTGTAGCATCCTCACAAATTCACTTTAGTTCCTTCGCATTCTGGTGTCGCTATATATTAGTGGGACTATGTCCCCATTAACCTGTTAGATCTCTTGAGAAAAGGGACATGTCTTTTCATCTTGA GTTCCCCAATACTTAGTATTGTGCTTAGCATATGCTAGGTGCTCAGTAAATATTTGATATGTGTGTGAACGAATGAATCAATCAATCAATAACAAATGACAGACAAACTCCAACCCCCAAACCTAAAAAAAAAAAATC CAAACTTTCCCCTTGCTCTTAGTGTAGATACTGCTCATCAACATAAGGCAAATTCTTCCTGCGCGTCTCAATACAGAGGAGGCGAGAACTCACAGAATCACAGAATTAGAGCACTGGCTTTGGCATGAGAACACCCTC AGTTAAAATCTGGCTTCTGCTATTTATTAGCCACATGACAGTGAATCTCCTTGAGCTTCTGTTTTGTACAAACTTAAGTTTGGCTTTGTGATCTTATTCCTCTTTGGTGCATCTGTACAACCCAACTGCTTATTCATA TGACACTGCTAAAACATGCCTTGCCTTCTCCCCCACTTTTTTTTTTGGAGACAGAATCTCCCTTTGTCACCCAGGCTGGAATTCAGTGGCGTGATCTCGGCTCACTGC AACCTCCACCTCTCCAGT -3′ underlined nucleotides: primer sequences bold nucleotides: homologous extremity of the 237 bp amplicon obtained with the primers MSP2#3-5. The sequence of the 396 bp amplicon hehr1/14100006-14100401 (C) is included in the larger size amplicon 1,088 bp Amplicon hChr1/14180006-14181093 The internal underlined nucleotides correspond to the reverse-complement sequence of primer hChr1/14180401 AS (hChr1#4). E) Genomic human Chromosome 7 primers #2 (hCbr7/4293490 S) and #6 (hChr7/4294983 AS) PCR-emplified 1,494 bp amplicon Identifier: Amplicon hChr7/4293490-4294983 5′- TCCTGCCTTAGTGAGGATCT TCCTATTCATCAAAGATAAAATACCAAATATAATTTACTCTCCTTCTCTACCTCACCCCCAATATTCAACAATTCCCTATTTTATTTTGATTTTACTTCCTATTGTCTCTCAGT GCATCCTTACTACTGGTTTCTGGCCTCAATGTCTCTTTCCATAAATACTTCCTCCAGGGCTTCAGCAGTGTATATTGCAATCCATGAGTGTGATGCCCTTATAAGCTGTACAGGCACAACCCAGGCAAACATACACAA TGACCATAATCATAACAGTCATTACTGGTGCCTTTACTCTGGTTTTATCCATCCCCCAACAATCCTTTAATCCTCCACTAGAGTTTATTCTTTTAAGTGAAAATCTGGATTCTTATCTCCCCTAGTATGTATCTCTTA GTGAATTTTTATATGAGATAGTCATCACCATCACCTATTCATCATCCCATTCCATCCACTGAAGTTATTTTACGCTATGGCCTTCACAAATTACTTTGAGTCCTTTAAATAGATTAAAAAGTTTCTTGACTCTTTTTG TACATGTCATTCTGTCCAAAGTGCAAATTTCACTATTGTCCACCCAAAGAATACTAAGTTTTCACCGTCATTTAAGCCTTTAATCTCAGGATCTCACAATAAATACAATCACTCTTTCCTATATGCCTAATCTTCTGC TTGAGCATAATTTTAATGTGCTAACTATTCTGTAATTATATATATATTTTTAATTCAGCCACTTCTCTCACTAGAAAGTGAGTTTGTTGAAATCAGGGTAAGTATATTTTATGTTTGGATGAATTCCCCATCACAATA CTTCACATGTAGTTATCTAGTCACCAATTTTTATTGAAATTAATTGTACATATAATAAAACTTTAATATAAAATGTTTCTCTTGAGGGGAGATTTTCTTTGTAAAACTATCCTTCTGAGCTTTGTGATGTGATGATTG TCTAATGTCTGTTGCAAGATTAAGGAAAATGTATTTGAATGCAAATGAACTTACACTGTCATACCAAAAGTGTGATAATTTCTTGCTCCTGAACTCACTCTCCCTACCTGCCTATTAAAATCAGAATACACAGATCTG TATCTG TACAAAGAGATGCCAAAAGACTAC TTTCATGCTGCAACATGATTATGTGCCCCCAAAACCTGGATATTTATAGTATAGTATCCAGTATTTTCAATCTAAGCTGTACTGGAGCCCGAAGCTAAAGGAAAATTA GTAATACTGATGCTCCCTTTATTTAAACTTTTAAGACTTTATCATGGCATTAATTTTGACTTTTAAAAATATTATCATTTTTTTTGGACCCCCTTAAATTTTGTTCCCGAGTTGAATGCCTCACTGGGACTTGGGTGA ATGAATGCTCACCCTAGTCCTAGATTAGGTACTCATCTTAAATACTGTTAGTTTGGGGTGGTTTTTTTTTTTTTTTTTTTTTTTTTTTTGACAGAGCCT CACTCTGTTCTCCAGGCTG underlined nucleotides: hChr7 genomic primer sequences bold nucleotides: homologous sequence of the 213 bp amplicon obtained with the primers MSP2#2-5. A part of the sequence 1,644 bp Amplicon hChr7/4292976-4294619 (B) is included in the amplicon 1,494 bp AmpliCon hChr7/4293490-4294983 (E). The internal underlined nucleotides correspond to the reverse-complement sequence of primer hChr7/4294619 AS (hChr7#5).
For legibility, enlarged versions spanning two side-by-side pages of the sequences shown in Appendix 5 above are provided below. The human chromosome 1 sequence amplified by the MSP2 primers shown below:
[0000] primer identifiers sequences MSP2 primer #3) Ac/mMSP2-1019S 5′-CTTAACAGAGTGAAGGCT where Y = T or C MSP1 primer #5) Ac/mMSP2-1026AS 5′-ATCATARTCCCATCACCTAA where R = G or A Sequence of the 237 bp amplicon generated with these two primers by PCR: 5′- ATCATAGTCACCATCACCT ACCAGCTGTATAAGCCACACACCTGGGAGTCCTCCTAGCCTTTTCCTCCT CCTCTCATCCTCCATTCCCATTGACCGTCAGGGCCTACTGAGTCTACACTCCAATTTTCTTTTAAATCTATC CCCACTGCCACTGTCCTACTCTAAGGCAATACCATCTGGTCACCCAGATCATTCCATAGCTTCCTAGTAAGT AGACCAGCCTTCACTCTGTAAG-3' underlined nucleotides: primer sequence bold nucleotides: divergent nuleotides between MSP2 primers and the corresponding homologous human Chr 1 sequence.
The human chromosome 7 sequence amplified by the MSP2 primers shown below:
[0000] primer identifiers sequences MSP2 primer #2) AphMSP2-10196 5′-GCCTACAGATTAAAGGCT MSP1 primer #5) Ac/mMSP2-1128AS 5′-ATCATARTCACCATCACCTA where R = G or A (same as above) Sequence of the 213 bp amplicon generated with these two primers by PCR: 5′- GCCTACAGATTAAAGGCT TAAATGACGGTGAAAACTTAGTATTCTTTGGGTGGACAATAGTGAAATTTGC ACTTTGGACAGAATTTTTAATCTATTTAAAGGACTCAAAGTAATTTGTGAAGGCCATAGCGTAAAATAACTTC AGTTGACATGTACAAAAAGAGTCAAGAAACGGATGGAATGGGATGATGAATAGGTGATGGTGACTATAGAT-3′ underlined nucleotides: primer sequence bold nucleotides: divergent nuleotides between MSP2 primers and the corresponding homologous human Chr 7 sequence.
Identities of the human sequences amplified by the human chromosome 1 primers described in section A) below.
[0000] A) Genomic human Chromosome 1 primers #1 (hChr1/14179308 S) and #2 (hChr1/14179853 AS) PCR-amplified 546 bp amplicon: indentifier: Amplicon hChr1/14179308-14179853 5′- CCTTACACTCAGCCAGACAT ATATTTGTGTTTTGTTATCCATGTGCACAGAGACTTTGGCAT TCTGGGTGAAGGAAGAAAGAAGAGAATATACATGGAAACCCAGGGGTAAGAGAAAAGGACAACAG AGAATGTGGCATGGGGAATGCTCTGCTGGGTCACATTGAATGGTTCTGAACCACTGTGGAAAAAA AGGAGTTAGAAAGAATCAGATGCCGAAGGAGCCAATTTTCACAATACTCCGAGACTCAGGGCAAA AGCAGCCTTGTTCTAGTAGCCTATGGGTAAAAGAAGACACAGAACTGAGGGGAGGACTTTTCCCC TGAGTCCACCACAAACCGCCATGGAGCTGAGGCAGCCTGAAGTCTCAGGGGCATGGGAGGGATTT GCCTTTTGGATTTCTCCAATGGGATGTCTTACAGGCACTTCATATTTAGCAGATCCAAAACTTAA CTCAGATACTCCTCTTGCCATATCTGTTCCTCTTGCTGTGTTCCTGACCATGATTATCACCATCA CCTACCAGC TGTATAAGCCACACACCTGG -3′
Identities of DNA sequences amplified by Human chromosome 7 primers described in section B) below:
[0000] B) Genomic human Chromosome 7 primers #1 (hChr7/4262976 S) and #5 (hChr5/4294619 AS) PCR-amplified 1,644 bp amplicon*: identifier: Amplicon hChr7/4292976-4294619 5′- ATGTAGTTGAGCAGTTTTGAATGA GTTTCTTAATCCTGAGTTCTAGTTTAAGAAAATATTAAAAATAAAAATTAT GTCACCAACTAAATTTTTACTGCAGATAATCATAAGTTGGTTAGATTGGACCTTCATTGTGAAATGCAGTAACTTTGG TTTAAGCAATATCCAAAACCAGAAATTGGTCGAGGGGTCTACTAAATTCCGTTTTCTTTTGTTCTAAACAATTAAACA TTCTAAAATTTAGGGAAAAGGACCAATGGTGCAAACATTTTAGAGCTGACAGTTGTGTGCCATATGCCATGATTCTGT TACAAATGAACAGTATTCAGATTCAAAATCAGTGTAAACACTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGTGT GTGTATTTTACACAGCCATTTAAATATTAACCGCCTTTGAGTATTAGGGGAAAAACAGAAACTAAAAGCGAATATATT TGTTTCCTGAATCCTCCCCACCAAACCACTTTTTAAATTAATTATATT TCCTGCCTTAGTGAGGATCT TCCTATTCAT CAAAGATAAAATACCAAATATAATTTACTCTCCTTCTCTACCTCACCCCCAATATTCAACAATTCCCTATTTTATTTT GATTTTACTTCCTATTGTCTCTCAGTGCATCCTTACTACTGGTTTCTGGCCTCAATGTCTCTTTCCATAAATACTTCC TCCAGGGCTTCAGCAGTGTATATTGCAATCCATGAGTGTGATGCCCTTATAAGCTGTACAGGCACAACCCAGGCAAAC ATACACAATGACCATAATCATAACAGTCATTACTGGTGCCTTTACTCTGGTTTTATCCATCCCCCAACAATCCTTTAA TCCTCCACTAGAGTTTATTCTTTTAAGTGAAAATCTGGATTCTTATCTCCCCTAGTATGTATCTCTTAGTGAATTTTT ATATGAGATAGTCATCACCATCACCTATTCATCATCCCATTCCATCCACTGAAGTTATTTTACGCTATGGCCTTCACA AATTACTTTGAGTCCTTTAAATAGATTAAAAAGTTTCTTGACTCTTTTTGTACATGTCATTCTGTCCAAAGTGCAAAT TTCACTATTGTCCACCCAAAGAATACTAAGTTTTCACCGTCATTTAAGCCTTTAATCTCAGGATCTCACAATAAATAC AATCACTCTTTCCTATATGCCTAATCTTCTGCTTGAGCATAATTTTAATGTGCTAACTATTCTGTAATTATATATATA TTTTTAATTCAGCCACTTCTCTCACTAGAAAGTGAGTTTGTTGAAATCAGGGTAAGTATATTTTATGTTTGGATGAAT TCCCCATCACAATACTTCACATGTAGTTATCTAGTCACCAATTTTTATTGAAATTAATTGTACATATAATAAAACTTT AATATAAAATGTTTCTCTTGAGGGGAGATTTTCTTTGTAAAACTATCCTTCTGAGCTTTGTGATGTGATGATTGTCTA ATGTCTGTTGCAAGATTAAGGAAAATGTATTTGAATGCAAATGAACTTACACTGTCATACCAAAAGTGTGATAATTTC TTGCTCCTGAACTCACTCTCCCTACCTGCCTATTAAAATCAGAATACACAGATCTGTATCTG TACAAAGAGATGCCAA AAGACTAC -3′ underlined nucleotides: hChr7 genomic primer sequences with the primers MSP2#2-5. bold nucleotides: homologous sequence of the 213 bp amplicon obtained r7/4293490 S (hChr7). The internal underlined nucleotides corrsepond to the sequence of primer hCh previous documents. The correct lenght is 1,644 bp.
Other amplicons obtained from HIV positive or HIV-negative patients or from both using the human chromosome 1 or human chromosome 7 primers described in sections C) and D) below.
[0000]
C) Genomic human Chromosome 1 primer #3 (hChr1/14180006 S) and #4
(hChr1/14180401 AS) PCR-amplified 396 bp amplicon:
Identifier: Amplicon hChr1/14180006-14180401 AS) PCR-amplified 396 bp amplicon:
5′- CATAGCTTCCTAGTAAGTAGACCAG CCTTCAGTCTGAGCCCTCCTCGGTCCTTCCTCCCCAGTGCT
GCTGGAGTAATCCTTCTAACACAACAATGGAAAGCAGGTCACTGCGGCTCAAATGATGTCAGCGGCTTT
ATCATCCATGTTGCCTGGCTTTTCACAGGCATGTCTTGCAGTGCAGCCTTATAACTCTCTCAACACAAC
TCTGTATCCTCCTCATTCTTCATGCTTTTATAATGTCAAGCCATGTGACACTCCCTAAATATACCATGT
TTCTCTTTTTCCTCCTCCCCCTCTCTCATTTGCAGCTTCCCATACTTATCTTCCTAAACACTACTCTTT
TTGAAATGTTTATTTCAAGGGTTTCTTATCTTTTA AACCATCTCAGACTCCCCT -3′
underlined nucleotides: primer sequence
bold nucleotides: homologous extremity of the 237 bp amplicon obtained with
D) Genomic human Chromosome 1 primer #3 (hChr1/14180006 S) and #5
(hChr1/14161093 AS) PCR-amplified 1,088 bp amplicon:
Identifier: Amplicon hChr1/10180006-14181093
5′- CATAGCTTCCTAGTAAGTAGACCAG CCTTCAGTCTGAGCCCTCCTCGGTCCTTCCTCCCCAGTGCT
GCTGGAGTAATCCTTCTAACACAACAATGAAAGCAGGTCACTGCGGCTCAAATGATGTCAGCGGCTTTA
TCATCCATGTTGCCTGGCTTTTCACAGGCATGTCTTGCAGTGCAGCCTTATAACTCTCTCAACACAACT
CTGTATCCTCCTCATTCTTCATGCTTTTATAATGTCAAGCCATGTGACACTCCCTAAATATACCATGTT
TTCTCTTTTTCCTCCTCCCCCTCTCTCATTTGCAGCTTCCCATACTTATCTTCCTAAACACTACTCTTT
TTGAAATGTTTATTTCAAGGGTTTCTTATCTTTTAA ACCATCTCAGACTCCCCT GGGGATTACCCCTTT
TCCTATGTTTTTATTGTAGCATCCTCACAAATTCACTTTAGTTCCTTCGCATTCTGGTGTCGCTATATA
TTAGTGGGACTATGTCCCCATTAACCTGTTAGATCTCTTGAGAAAAGGGACATGTCTTTTCATCTTGAG
TTCCCCAATACTTAGTATTGTGCTTAGCATATGCTAGGTGCTCAGTAAATATTTGATATGTGTGTGAAC
GAATGAATCAATCAATCAATAAGAAATGACAGACAAACTCCAACCCCCAAACCTAAAAAAAAAAAATCC
AAACTTTCCCCTTGCTCTTAGTGTAGATACTGCTCATCAACATAAGGCAAATTCTTCCTGCGCGTCTCA
ATACAGAGGAGGCGAGAACTCACAGAATCACAGAATTAGAGCACTGGCTTTGGCATGAGAACACCCTGA
GTTAAAATCTGGCTTCTGCTATTTATTAGCCACATGACAGTGAATCTCCTTGAGCTTCTGTTTTGTACA
AACTTAAGTTTGGCTTTGTGATCTTATTCCTCTTTGGTGCATCTGTACAACCCAACTGCTTATTCATAT
GACACTGCTAAAACATGCCTTGCCTTCTCCCCCACTTTTTTTTTTGGAGACAGAATCTCCCTTTGTCAC
CCAGGCTGGAATTCAGTGGCGTGATCTCGGCTCACTCC AACCTCCACCTCTCCAGT -3′
underlined nuleotides: primer sequences
bold nucleotides: homologous extremity of the 237 bp amplicon obtained
with the primers MSP2#3-5
The sequence of the 396 bp amplicon hChr1/14180005-14180401 (C) is
included in the largers size amplicon 1,088 bp Amplicon hChr1/14280006-1418109
The internal underlines nucleotides correspond to the reverse-complement
sequence of primer hChr1/14180401 AS (hChr1#4).
E) Genomic hmman Chromosome 7 primers #2 (hChr7/4293490 S) and #6
(hChr7/4294983 AS) PCR-amplified 1,494 bp amplicon:
Identifier: Amplicon hChr7/4293490-4294983
5′- TCCTGCCTTAGTGAGGATCT TCCTATTCATCAAATATAAAAATACCAAATATAATTTACTCT
CCTTCTCTACCTCACCCCCAATATTCAACAATTCCCTATTTTATTTTGATTTTACTTCCTATTGT
CTCTCAGTGCATCCTTACTACTGGTTTCTGGCCTCAATGTCTCTTTCCATAAATACTTCCTCCAG
GGCTTCAGCAGTGTATATTGCAATCCATGAGTGTGATGCCCTTATAAGGTGTACAGGCACAACCC
AGGCAAACATACACAATGACCATAATCATAACAGTCATTCTGGCTGCCTTTACTCTGGTTTTATC
CATCCCCCAACAATCCTTTAATCCTCCACTAGAGTTTATTCTTTTAAGTGAAAATCTGGATTCTT
ATCTCCCCTAGTATGTATCTCTTAGTGAATTTTTATATGAGATAGTCATCACCATCACCTATTCA
TCATCCCATTCCATCCACTGAAGTTATTTTACGCTATGGCCTTCACAAATTACTTTGAGTCCTTT
AAATAGATTAAAAAGTTTCTTGACTCTTTTTGTACATGTCATTCTGTCCAAATGTGCAAATTTCA
CTATTGCCACCCAAAGAATACTAAGTTTTCAGCGTCATTTAAGCCTTTAATCTCAGGATCTCACA
ATAAATACAATCACTCTTTCCTATATGCCTAATCTTCTGCTTGAGCATAATTTTAATGTGCTAAC
TATTCTGTAATTATATATATATTTTTAATTCAGCCACTTCTCTCACTAGAAAGTGAGTTTGTTGA
AATCAGGGTAAGTATATTTTATGTTTGGATGAATTCCCCATCACAATACTTCACATGTAGTTATC
TAGTCACCAATTTTTATTCAAATTAATTGTACATATAATAAAACTTTAATATAAAATGTTTCTCT
TGAGGGGAGATTTTCTTTGTAAAACTATCCTTCTGAGCTTTGTGATGTGATGATTGTCTAATGTC
TGTTGCAAGATTAAGGAAAATGTATTTGAATGCAAATGAACTTACACTGTCATACCAAAAGTGTG
ATAATTTCTTGCTCCTGAACTCACTCTCCCTACCTGCCTATTAAAATCAGAATACACAGATCTGT
ATCTG TACAAAGAGATGCCAAAAGACTAC TTTCATGCTGCAACATGATTATGTGCCCCCAAAACC
TGGATATTTATAGTATAGTATCCAGTATTTTCAATCTAAGCTGTACTGGAGCCCGAAGCTAAAGG
AAAATTAGTAATACTGATGCTCCCTTTATTTAAACTTTTAAGACTTTATCATGGCATTAATTTTG
ACPTTTAAAAATATTATCATTTTTTTTGGACCCCCTTAAATTTTGTTCCCGAGTTGAATGCCTCA
CTGGGACTTGGGTGAATGAATGCTCACCCTAGTCCTAGATTAGGTACTCATCTTAAATACTGTTA
GTTTGGGGTGGTTTTTTTTTTTTTTTTTTTTTTTTTTTTGACAGAGCCT CACTCTGTTCTCCAGG
CTG
underlined nuclectides: hChr7 conomic primer sequences
bold nucleotides: homologous sequence of the 213 bp amplicon obtained
with the primers MSP2#2-5.
A part of the sequence 1,644 bp Amplicon hChr7/4292976-4294619 (B)
is included in the amplicon 1,494 bp Amplicon hChr7/4293490-4294983 (E).
The internal underlines nucleotides correspond to the revierse-complement
sequence of primer hChr7/4294619 AS (hChr7#5).
APPENDIX 6
[0069] An amplicon of the 16s rDNA primers (SEQ ID NOS: 24 and 25) is shown below. The amplified DNA originated from the red blood cells of an HIV-negative subject passaged in HL60 cells. Similar DNA is amplified from samples originating from red blood cells of HIV-positive subjects.
[0000]
Amplicon from HIV-negative subject obtained using primers.
>T56-EMK-4-HIV-_Anae#2-5 wo/ primers seq. = 681 bp
(SEQ ID NOS: 24 and 25)
GCACCTGTATGT GAATTC CCGAAGGCACTCCCGCATCTCTGCAGGATTCTCACTATGTCAAGACCAGGTAAGGTTCTTCGCGT
TGCATCGAATTAAACCACATGCTCCACCGCTTGTGCGGGCCCCCGTCAATTCATTTGAGTTTTAACCTTGCGGCCGTACTCCC
CAGGCGGTCTACTTATCGCGTTAACTGCGCCACTAAAGTCTCAAGGACCCCAACGGCTAGTAGACATCGTTTACGGCGTGGAC
TACCAGGGTATCTAATCCTGTTTGCTACCCACGCTTTCGAATCTCAGTGTCAATATTATGCCAGGAAGCTGCCTTCGCCATCG
GCATTCCTCCAGATCTCTACGCATTTCACCGCTACACCTG GAATTC TACTTCCCTCTCACATATTCTAGCACCACCAGTATCA
CATGCAGTTCCCAGGTTAAGCCCGGGGATTTCACATGTGACTTAATGAGCCACCTACACTCGCTTTACGCCCAGTAATTCCGA
TTAACGCTCGCACCCTCTGTATTACCGCGGCTGCTGGCACAGAGTTAGCCGGTGCTTATTCTGCAGGTAACGTCTAATCTAAT
GGGTATTAACCATTAGCCTCTCCTCCCTGCTTAAAGTGCTTTACAACCAAAAGGCCTTCTTCACACACGCGGCATGGCTGGAT
CAGGGTTGCCCCCCATT | A method for identifying a risk factor for diseases, disorders or conditions, such as those caused by human immunodeficiency virus, using the polymerase chain reaction and specific primers. Methods for treating patients having these diseases, disorders or conditions by antimicrobial treatment of the risk factor by combined antiviral and antibacterial treatment or by sustaining or stimulating the subject's immune system. Methods for screening biological products including red blood cell preparations. Primers and methods for detecting nucleic acids or microbial agents associated with red blood cells, such as those associated with red blood cells in subjects infected with HIV and undergoing antiretroviral therapy. | 2 |
RELATED PATENT APPLICATIONS
The present application is a continuation in part of application Ser. No. 09/653,489, filed Aug. 31, 2000, now U.S. Pat. No. 6,495,020 which is, in turn, a divisional of application Ser. No. 09/518,006, filed Mar. 2, 2000, now U.S. Pat. No. 6,368,147 issued Jun. 25, 2002.
STATEMENT OF GOVERNMENT SUPPORT
This invention was made with government support under 2R44NS33427 awarded by the SBIR. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
The present invention is a method of making a flexible brain probe assembly.
Creating a probe that contacts the brain tissue represents a challenge to researchers. Researchers typically wish to measure electrical activity at specific sites within the brain that share a well-defined physical relationship to one another. Probes produced by photolithographic techniques, such as the probe designed by personnel at the University of Michigan that is known in the industry and research community as the “University of Michigan Probe,” permit the accurate placement of electrode sites that are sufficiently small to permit the measurement of electrical activity at a specific set of predefined sites within the brain. Unfortunately, the desire to use photolithography has prompted the use of silicon as a substrate. Because this material is quite brittle, the use of it creates a risk of breakage inside the brain, endangering the subject or patient and limiting the insertion strategies available to researchers. Moreover, the use of silicon prevents the University of Michigan probe from moving with the brain, which does move about slightly within the skull. In addition, silicon is subject to some restoring force, which tends to cause a silicon probe to migrate over time. Both of these drawbacks have the potential result of causing trauma to the brain tissue.
Another type of probe that is currently available includes a set of insulated wires having laser created apertures exposing electrode sites. Although this type of probe is useful for many applications, it does not yield the precision or the freedom of electrode placement that the University of Michigan probe permits.
A nerve cuff is a device for wrapping about a nerve to electrically stimulate and/or receive electric signals from the nerve. The production of nerve cuffs has also been problematic as the fine scale of the needed features has been difficult to produce on a flexible substrate capable of being wrapped about a nerve.
What is needed but not yet available is an electrode probe and method of making the same that affords unconstrained and accurate placement of the electrodes, but offers flexibility and robustness and is thereby less susceptible to breakage than currently available probes.
SUMMARY
In a first separate aspect, the present invention is a method of producing an electrode bio-probe assembly, using a flexible substrate comprising a polymeric layer bearing a conductive material coating. Photolithography and electroplating are used to form a set of contacts and conductors on the polymeric layer of the flexible substrate. Also, the flexible substrate is shaped to have a distal end and to be greater than 5 mm long, less than 5 mm wide and less than 1 mm thick.
In a second separate aspect, the present invention is a method of producing a nerve cuff assembly for application to a target nerve. The method includes the use of photolithography and electroplating to form a set of contacts and conductors on the polymeric layer of a flexible substrate having a polymeric layer and bearing a conductive material coating. The flexible substrate is sized and shaped to fit about the target nerve.
The foregoing and other objectives, features and advantages of the invention will be more readily understood upon consideration of the following detailed description of the preferred embodiment(s), taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the connector of FIG. 1, shown attached to a skull and connected to a brain probe that is embedded in brain tissue.
FIG. 2 is an exploded perspective view of a connector according to the present invention.
FIG. 3 is a perspective view of the connector of FIG. 1, with the two connector halves mated.
FIG. 3A is a perspective of a portion of an alternative embodiment to FIG. 1, showing the differing structure of the alternative embodiment.
FIG. 4 is a greatly expanded plan view of a connective surface of the connector of FIG. 1 .
FIGS. 5 a - 5 g is a series of greatly enlarged side cross-sectional views showing the construction of the connector flex circuit, or thin film, which may include the brain probe flex circuit of FIG. 1 in a single unit.
FIG. 6 shows an expanded flexible brain probe, according to the present invention, and a tool for pushing this brain probe through brain tissue, also according to the present invention.
FIG. 7 shows the flexible brain probe and tool of FIG. 6, in a 180° rotated view.
FIG. 8 shows a nerve cuff produced in accordance with the present invention, wrapped about a nerve.
FIG. 9 shows a nerve cuff produced in accordance with the present invention.
FIG. 10 shows an alternative embodiment of a nerve cuff produced in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a percutaneous connector 10 is screwed into the skull 1 and is connected, by way of a multi-conductor microcable 20 , to a brain probe 24 that passes through an aperture 2 in the skull, through the dura 4 (and into the brain 6 ), for measuring brain activity at a specific set of points.
Referring to FIGS. 2, 3 and 3 A a percutaneous connector 10 according to the present invention includes a male-half 12 , a female-half bracket 14 and a female-half flex circuit (or flexible polymer) connective assembly 16 bearing a set of contacts 17 and conductive traces 19 . A multi-conductor microcable 20 forms a portion of assembly 16 and is threaded through an aperture 22 in bracket 14 . The microcable 20 attaches to and extends traces 19 to brain probe 24 . As shown in FIG. 3 a in an alternative embodiment, a connective assembly 16 ′ includes a microcable 20 ′ that includes a brain probe 24 ′ as a unitary part of its construction. The male-half includes a resilient clip portion 28 , the exterior of which is covered with a flex-circuit 34 bearing a set of contacts 36 (matching the arrangement of contacts 19 ) and conductive traces 38 .
A first prong 40 and a second prong 42 , which is physically coincident with an op-amp housing, partially defines clip portion 28 . A user can grasp male-half 12 by the first and second prongs 40 and 42 to squeeze these prongs 40 and 42 together. The male-half 12 can then be inserted into the female-half 14 , without exerting pressure against female-half 14 , which could cause pain or tissue trauma to the patient or test subject. Finally, the user releases prongs 40 and 42 so that the resiliency of clip 28 will force each exterior side of clip 28 , and therefore contacts 36 , to touch the contacts 17 in female-half 14 .
Referring to FIG. 4 and 5 a - 5 g , contacts 17 and traces 19 are made of conductive material, such as a metal (copper, gold or sliver) or a conductive polymer that has been deposited and etched on top of a laminate having a layer of dielectric substrate 50 and a base layer silicone 70 or some other biocompatible, compliant material. Semicircular isolation cuts 48 through the layers 50 and 70 (in an alternative preferred embodiment only layer 50 is cut through by the laser) positionally decouple a first contact 17 a from neighboring contacts 17 b , 17 c and 17 d , permitting contact 17 a to be depressed into the spongy layer of silicone 70 without pulling down the neighboring contacts 17 b , 17 c and 17 d . This independent depressability causes the protrusional misalignment of contacts 17 and 36 to be forgiven.
The miniature scale that is made possible by the use of photolithography and flex circuit technology, as described above, facilitates a further advantage that may be realized as part of the present invention. This is the placement of op amps in extremely close proximity to contacts 36 . For connectors in which the contacts are spread apart from each other, it is necessary to gather together conductive paths from all the different contacts prior to sending them all to a set of op amps. Because contacts 36 are all so close together, traces 38 are routed to a set of op amps 44 , that are about 0.5 cm away and are housed in the second prong 42 , which doubles as an op amp housing. As a result, signal line noise and cross talk are minimized.
Referring to FIGS. 5 a - 5 g , the photolithography process for making the brain probe 24 and the contacts of the percutaneous probe contact structure 30 are quite similar, except that different materials may be used and the percutaneous probe contact structure 30 includes a base layer of silicone 70 , that is only shown in FIG. 5 g , for the sake of simplicity. Referring specifically to FIG. 5 a , the photolithography process begins with a layer of dielectric substrate 50 , the composition of which is discussed below, that is coated with a base layer of conductive material 52 , such as a titanium-gold-titanium sandwich. FIG. 5 b shows the structure of FIG. 5 a , which at this point has been covered with a layer of photo resist material 54 , typically applied by spin-coating. FIG. 5 c shows the effect of exposing the photo resist material to a pattern of light and washing off the exposed (or not exposed if a negative process is used) material with a developing agent. Next, as shown in FIG. 5 d , additional conductive material (typically copper) is built up on the exposed base layer 52 , typically through electrolysis. As shown in FIG. 5 e , the remaining photo resist material 54 is washed off with a solvent and a layer of dielectric (and permanent) photo resist 58 is applied and patterned, via exposure to a pattern of light and subsequent washing with a developing agent or solvent. Then, additional electrolytic plating is performed (FIG. 5 f ) to create a contact 60 and the substrate is cut with an nd:YAG laser to form a kerf or cut 62 . When the process shown in FIGS. 5 a - 5 g is for producing connector 10 , cut 62 is the same as isolation cut 48 . When the process shown in FIGS. 5 a - 5 g is for producing a brain probe 24 , cut 62 separates a first brain probe 24 from a wafer or thin plastic film upon which several brain probes have been etched. In contrast to the situation with respect to silicon, which may be separated by etching, it appears that no etching process has been developed for cutting the materials used for substrate 50 , which are discussed below.
The dielectric substrate 50 that is used for the brain probe 24 is preferably a polymer material having a high glass transition temperature, high tensile strength and low elasticity. More specifically, substrate 50 may be made of polyether sulfone, polyimide or other material having the desired characteristics. If polyimide is used, it should be coated or treated so that it does not dissolve in the body's interstitial fluid, or used for a probe that is not to be implanted for long enough for the polyimide to dissolve. Photo resist material 54 may be a photosensitive acrylate, polyether or polyurethane, preferably having a high molecular weight. Permanent photo resist 58 may be a permanent polyimide, a type of material that is widely available from well-known photo resist companies. These companies typically sell a wet etch agent specifically designed to etch each permanent polyimide photo resist that they sell.
Brain probe 24 includes three prongs 72 . Each prong 72 is on the order of 15 mm long, 3 mm wide and 0.3 mm thick. During the manufacturing process each prong 72 is sharpened so that it may more easily be driven through the brain tissue. It is desirable that a brain probe, if it is to be implanted for a period of time on the order of weeks, be very pliable, so that it may conform to the brain tissue surrounding it and not cause further damage by pressing against the delicate brain tissue. If the brain probe is to be installed by being driven through brain tissue, however, it must be fairly rigid, requiring a strength layer, such as layer of steel or some other resilient material, laminated beneath layer 70 , typically before the production process begins.
Referring to FIGS. 6 and 7, in one preferred embodiment a brain probe 80 is constructed to be very pliable. In brain probe 80 only a single point 90 is provided, in order to facilitate the placement process, which is complicated by the three-pointed (or pronged) embodiment shown in FIG. 3 . FIG. 6 shows brain probe 80 in tandem with a placement tool 84 , which engages brain probe 80 at aperture 86 . Placement tool 84 is used to push the point of probe 80 through brain tissue 6 (FIG. 1) , to the point at which contact with brain tissue 6 is desired. For chronically implanted brain probes, the quality of being pliable may be very important, to avoid the damage that a rigid brain probe could inflict with patient movement. The brain moves about in the skull with patient head movement, and colliding with a rigid probe could easily damage the soft brain tissue.
In the embodiment of FIG. 6, electrodes 17 are from 12.56 square microns to 300 microns in surface area. In one preferred embodiment electrodes 17 are 176 have a surface area of 176 square microns. The probe 80 , itself is at least 5 mm long, and no more than 5 mm wide and 1 mm thick. In the preferred embodiment shown, cuts 48 are through-cuts and permit tissue ingrowth , which along with the tissue ingrowth at aperture 86 helps to anchor brain probe 90 , in the brain tissue. In an alternative preferred embodiment, cuts 48 are not present.
Referring to FIGS. 8, 9 and 10 , the method of construction shown in FIGS. 5 a - 5 g is used for the production of nerve cuffs 100 , 110 and 120 . A nerve cuff is a device that is adapted to be wrapped around a nerve 130 and used to electrically stimulate the nerve 130 . In nerve cuff 110 a set of twelve contacts 112 have been created through photolithography. In nerve cuff 120 four complex contacts 122 , designed for circumferentially contacting a nerve have been created by way of photolithography.
The terms and expressions which have been employed in the foregoing specification are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow. | A method of producing an electrode brain probe assembly, using a flexible substrate comprising a polymeric layer bearing a conductive material coating. Photolithography and electroplating are used to form a set of contacts and conductors on the polymeric layer of the flexible substrate. Also, the flexible substrate is shaped to have a distal end and to be at least 5 mm long, but less than 5 mm wide and less than 1 mm thick. | 0 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to the tracking of object states by a computer; more particularly, the invention aims at optimizing the encoding of the object states to reduce computer resources consumption when tracking object states.
BACKGROUND OF THE INVENTION
[0002] An application typically using object states encoding is static analysis of variables in compilers. In this step of static analysis, the compiler validates the code flow by detecting the impossible variable states or transitions in each branch of the code. One other application is inventory management of physical objects such as containers on which are attached Rfids able to record the container's id and states.
[0003] Objects states are well represented by a collection of Boolean properties such as a given local variable which can be deemed valued to null, or not, initialized, or not, etc., at a given point in time. Similarly, a container may have different states depending if it is in a warehouse, on board a truck, on board a train, on board a ship, etc. During the life of objects, events drive predictable changes in objects states, called states transitions, that programs must track. Transitions on those states are coded by use of Boolean arithmetic with the usual operands (and, or, not) to implement truth tables. Truth tables typically give, for a given operation, and the entry states of one to many objects, the expected states of the objects after the transition has occurred. Coming back to the example of a variable in a program, when a local variable that is not initialized is assigned a value, it becomes initialized: in other terms, its ‘initialized’ Boolean property changes from false to true; similarly, with the example of container, when a container is unloaded from a truck into a warehouse, its ‘on board truck’ property becomes false and its ‘in warehouse’ property becomes true. The use of Boolean variables is efficient for the storage of states and the computation of states transitions because the underlying technology (memory, buses and processors) uses bits sets, usually grouped by words that comprise 32, 64 or 128 bits, at the very heart of computing and storage systems. Moreover, it implements efficient Boolean operations on those sets.
[0004] When the number of objects for which the states must be tracked and computed becomes very large, one encoding technique that is eventually efficient both in terms of space and time is to use a set of large bitfields (each set typically comprised of an array of words), each bitfield coding one of the Boolean properties, and each object being associated to a specific rank within the bitfields. Using the bitwise operators of the used programming language to operate Boolean transformation one word at a time, states transformations can be operated for objects sets instead of demanding for a per object computation. For example, if we take 8 bit long bitfields and associate the lower order bit to object 1 , the following bitfield encodes a given Boolean property as being true for object 1 , false for object 2 , true for object 3 , false for others: “0000 0101”
[0005] There is a potentially big issue with this approach though. It is very weak at detecting impossible states, that is, states that the objects cannot reach. Taking an obvious example, a variable cannot simultaneously be initialized and not initialized, or a container cannot be at the same time on board a train and on board a ship (whereas it could be on board a truck and on board a ship). If the programmer initially chooses to code the ‘initialized’ and ‘uninitialized’ properties into two separate Boolean variables, the fact that those properties are always linked by a negation may go unnoticed for a while. If this remains unnoticed, the encoding will consume one more property than needed per object, resulting into space waste and superfluous calculations. This example is obvious but less obvious examples abound when the state variables number grows. For example, in the container case, ‘on board train’ and ‘on board ship’ are negatively correlated, whereas ‘on board truck’ and ‘on board ship’ are not.
[0006] There is also a considerable amount of prior art work related to the optimization of Boolean multi-variate transformations. For an example, see ‘Two-level logic optimization’, Coudert et al., 2001 (in IKLUWER INTERNATIONAL SERIES IN ENGINEERING AND COMPUTER SCIENCE SERIES) ([Coudert 2001]). Their main focus is on providing ways to produce near optimal Boolean logic for use in dedicated hardware circuitry. An elaboration of these is very useful in any multi-variate Boolean transformation. These do not fulfill the needs exposed above by themselves though, since they only tackle the reduction of the time needed to implement given truth tables. They do not address the reduction of the number of considered variables. When applied to the initial problem of optimizing object states and transitions, this prior art would deliver a gain in computation time but not in space.
[0007] Hence, there is a need for a solution that enables programmers to define states and transitions according to the desired semantics and still implement them in an efficient way in terms of space for encoding them.
[0008] A first step in space optimization for encoding object states and transitions has been observed at least in Eclipse, an open source project on the web site http://www.eclipse.org, and more particularly in the class: org.eclipse.jdt.internal.compiler.flow.UnconditionalFlowInfo for the 3.1 version of the product. This implementation uses natural Boolean sets to encode the states of numerous objects in a relatively efficient manner by using bitfield encoding. This implementation adds new functions to the compiler, and drives the number of Boolean properties up, raising concerns about a degradation of performances on time and space. An ad hoc approach enabled the development team to identify some of the unneeded combinations and to re-encode the states by coordinating some Boolean pairs (that is, for example, the meaning of the first bit depends on the value of the second bit).
[0009] This proved error prone, gave no warranty regarding optimality of the resulting encoding, and is very inflexible (the addition of a new state variable breaks the encoding). As a consequence, in order to save space and to keep complexity under control, developers cut back on functionalities. In conclusion, bitfield encoding is part of the solution but it is not sufficient for saving space with an important number of objects.
SUMMARY OF THE INVENTION
[0010] It is an object of the invention when a model has been defined in an intuitive way for accessing object states and transitions to provide an equivalent access to object states and transitions while making this access more efficient in terms of computer resources.
[0011] A first aspect of the present invention provides a method for creating a code implementing an API, wherein a set of objects has been numbered, the API accessing object states and transitions, the method comprising: reading the API and defining a corresponding set of object states expressed by a list of Boolean variables, initial object state values and object states transitions; reading the defined object states, the initial object state values, and transitions and creating a set of corresponding truth tables; reading the created set of truth tables and performing a transitive closure of the starting states providing as a result a list of possible object states among the defined object states; numbering the possible objects states; reading the set of truth tables and, using the numbered possible object states, creating a new set of truth tables; and reading the new set of truth tables and generating code for implementing the transitions by using a bitfield encoding of the numbered objects.
[0012] The bitfield encoding of the objects can be performed at any time before execution of step for generating the code.
[0013] The step of generating the code can be executed using the [Coudert 2001] algorithm.
[0014] A new numbering of the possible object states can be introduced after execution of the computer numbering the possible objects states.
[0015] A computing resource cost estimate function can be introduced and used to compute the cost estimate of the generated code. If all the possible numbering are not used, the numbering of the possible objects states can be changed, a new set of truth tables can be created, and code generated. The cost estimate of the generated code can be determined using the cost estimate function such that the generated code corresponds to the best cost estimate.
[0016] Before testing if all the numbering functions are used, testing can be done to determine if the end of a defined computing period is reached, and if so, the process ends.
[0017] The defining of a set of object states expressed by a list of Boolean variables comprises: defining a set of object states expressed by a list of Integral variable and Boolean variables; and encoding the integral variables of the list into Boolean variables.
[0018] Another aspect of the present invention provides a computer program product comprising programming code instructions for executing the steps of the method when the program is executed on a computer.
[0019] Another aspect of the present invention provides a system for carrying out the method.
[0020] With the solution of the invention object states, transitions, and the function to access the object states and transitions are provided as an initial Finite State Machine which may be implemented as a Java class. The result of the method is an optimized Finite State Machine providing the same function as the initial Finite State Machine but wherein the object states and transitions are encoded in a very efficient manner, and particularly in a reduced space.
[0021] A further advantage of the solution is to be compatible with a hardware logic implementation as being based on Boolean variables. For applications that demand extreme performances, transitions can even be implemented as specialized hardware circuitry, which gives the the encoding technique a further advantage.
[0022] Typically, the exploration of the needed states and transitions is led by the use of ‘natural properties’ of the objects. The programmer or analyst in charge of modeling the object states and transitions can create a model by introducing about each state property and each possible transition in a conceptual manner. The initial Finite State Machine is created in an intuitive way matching the application needs. Then, with the use of the method of the invention the resulting Finite State Machine will implement the same function than the initial one and will apply to object states and transactions encoded in a much more efficient way.
[0023] The present invention proposes a method that, given a set of Boolean state variables, a set of state transitions described as truth tables for the the state variables, a set of initial states (that is states that objects happen to be in when they are brand new or when they are introduced into the system), all established by a natural modeling of the application domain, can derive an encoding that is provably isomorphic to the initial one but smaller, and transitions that match exactly the initial transitions but operating upon the new encoding, without incurring a significant time penalty. This effect is obtained by generating the extensive set of significant states, renumbering those states, then modifying the transitions implementation so as to use the renumbered states in place of the original ones. If the variables describing an object state are not Boolean, this means that they are expressed by a n-uple of numerated variables, there is always a way to transform them into a set of Boolean variables as explained in FIG. 3 , step 310 .
[0024] In some situations, the invention mail fail to deliver a more efficient encoding than the natural one. We contend that in such cases the natural encoding is close to a near optimal one. This happens when, at the end of execution of Transitive closure (step 320 ), if the number of elements of the states set can be represented by a binary number which length—defined as its number of bits—is strictly smaller than the number of Boolean variables that describe the objects states, then let NB be the length of the the number, and proceed to the step of numbering the object states; else, the invention cannot be applied and the natural encoding should be considered as a near optimal encoding of the states.
[0025] After object state new encoding, the resulting state variables do no more bear any semantics. Which means that modifying any of the states or transitions without performing the complete method of the invention is due to break the program. However, the invention is due to offer smaller encoding, and to avoid many errors induced by wrong assumptions from the programmer about encoding equivalences.
[0026] Prior art used for performing the steps of bitfield encoding or the step of generation by [Coudert 2001] of the implementation of the API with the new encoding brings even more efficiency to the method of the invention. An even greater efficiency in terms of use of computer resources is obtained by optimizing the numbering of the object states by the extension of the method with the loop for cost estimate calculation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a system environment of a method in accordance with an embodiment.
[0028] FIG. 2 illustrates a use of a Finite State Machine to implement management of object states and transitions.
[0029] FIG. 3 is a general flowchart of the method in accordance with the embodiment.
[0030] FIG. 4A-4B depict the general flowchart of FIG. 3 extended with steps with computer resource cost estimate computation for improving transition implementation.
DETAILED DESCRIPTION OF THE INVENTION
[0031] FIG. 1 depicts a system environment of a method in accordance with an embodiment. In FIG. 1 the boxes represent the logical layers which could be implemented as software programs executing on one or more data processing systems. A hardware logic implementation can be also considered.
[0032] In the embodiment, a designer who may or not be the same designer who has designed a customer application ( 100 ) defines the objects, the objects states and transitions as well as functions to access them in an initial Finite State Machine SSM 1 ( 110 ). With this initial Finite State Machine SSM 1 , the customer application performs calls to an API for accessing the object states and transitions. The method of the invention is implemented as a transformation engine E ( 120 ) that derives a new Finite State Machine SSM 2 ( 130 ) from SSM 1 , taking into account the initial states of objects SInit ( 140 ). The new Finite State Machine SSM 2 provides the same functions than the initial one SSM 1 but in it the object states and transitions are encoded in a very efficient manner. According to the embodiment, the same Application Program Interface API 1 ( 150 ) used by the customer application to call SSM 1 is used to call SSM 2 . To make the access to SSM 1 or SSM 2 transparent to the customer application, a distinguishing component I 1 ( 160 ) in SSM 1 and I 2 ( 170 ) in SSM 2 implements the API by SSM 1 and by SSM 2 respectively.
[0033] The transformation engine E ( 120 ) provides an automated and reliable means to derive the state machine SSM 2 from SSM 1 . More particularly, it derives from the original implementation I 1 of the the API, another implementation I 2 that delivers exactly the same function, the I 2 implementation being code based, near optimal in space, and efficient in time.
[0034] It is noted that the transformation Engine ( 120 ) is applied on inputs prepared by a designer reading the API and interpreting the content for listing the object states, the initial object states and the transitions. Also during execution, the Engine uses numbering of objects as defined in the API. As it is described in the rest of the document, more than one Engine can be defined according to improvements brought in the execution of some steps (Use of a prior art [Coudert 2001] algorithm for the minimization of the code that implements the truth tables, choice of the best numbering of object states to provide the best computing resource cost).
[0035] FIG. 2 illustrates the use of a Finite State Machine to implement the management of object states and transitions. Such a Finite State Machine is preferably implemented as software, for instance as Java classes, fields and methods.
[0036] Such a State Machine comprises a set S of states Si, i taking values from the [1, NS] interval, that describes the states a given object can be in. It comprises also a non-empty subset SInit of S which describes the states an object may be in when entering the system (these are called the initial states; SInit is often a singleton); a set E of events Ei, i taking values for the [1, NE] interval, that describes the events that can be fired upon an object; transitions that each object will undergo as an effect of events, as a projection of the Cartesian product S×E upon S (for each i in [1, NS], each j in [1, NE], the transition defines STij as the state an object would be in after event Ej had been fired upon the the object while it was in state Si).
[0037] Continuing with the example of defining Set State Machine starting from states encoded as n-uples of Boolean values, S is then seen as B elevated to power NB, where B has only two elements, known as true and false. Let SBij, i taken from [1, NS], j taken from [1, NB], be the value of the jth Boolean value for state Si. It is noted that state machines implemented by software can always be considered as fulfilling this requirement, because, in the current state of the technology, numbers are stored and computed as bit sets, which can be equated to Boolean Cartesian products.
[0038] The simple state machines above, are extended to define transitions as a projection of S×S×E upon S (for each i in [1, NS], each j in [1, NS], each k in [1, NE], STijk defines the state an object would be after event Ek had been fired upon the the object while it was in state Si, under the additional condition that the event Ek would be further parameterized by the state Sj). Typical examples of such extended machines would include cases where events are parameterized by an object instance, potentially distinct from the object upon which the event is fired. In the context of flow analysis, this is what happens when the association of two code paths is computed to determine the downstream state of the considered object.
[0039] In the naive implementation of the above State Machine with the Java language, a class would describe objects. Boolean fields of that class would encode the states. Methods of the class would implement reactions to events and effect transitions by modifying the fields. S×E→S transitions would be implemented by such methods that would take no parameter. S×S×E→S transitions would be implemented by such methods taking one instance of the same class as parameter.
[0040] According to the embodiment, the state machines as described above are used upon sets of objects, this use being most pertinent when the the sets of objects contain numerous instances. Let O be an ordered set of objects that contains NO objects. The state of O takes its values into S power NO. By extension of the state machines described above, the system will consider a ‘state set machine’ specified by:
[0041] a set Q of queries Qn, n taking values from the [1, NQ] interval, that each, given an object set O, i taken from [1, NO], j taken from [1, NB], can answer SOij defined as the value of the jth Boolean value for the state of the ith object of O; such queries would typically be implemented as methods upon the class of O, taking an integral parameter (the object index) and returning a Boolean value, that would not modify O in any respect; the fact that O holds complete objects or only the representation of their states is unimportant for the invention;
[0042] a set P 1 of procedures P 1 n, n taking values from the [1, NP 1 ] interval, that each, given an object set O, i taken from [1, NO], j taken from [1, NE] and such that Ej is an event that is not further specialized by objects states, will apply to Oi, the ith object of O, the effect of event Ej; it is further assumed that the states of Ok for k different from i never affect the result of any of these procedures; such procedures would typically be represented as methods upon the class of O, taking an integral parameter (the object index) and returning nothing, that would only modify the internal representation of Oi's state;
[0043] a set P 2 of procedures P 2 n, n taking values from the [1, NP 2 ] interval, that each, given an object set O 1 , an object set O 2 , i taken from [1, NE] and such that Ei is an event that is further specialized by an object state, will apply to each object O 1 j, j from [1, NO] of O 1 the effect of Ei further specialized by the value of the object O 2 j of O 2 which as the same index as O 1 j; it is further assumed that the states of O 1 k and O 2 l for k and l different from j never affect the result of these procedures upon Oj when Oj is considered; note that NP 1 +NP 2 equals NE; such procedures would typically be represented as methods upon the class of O, taking an integral parameter (the object index) and an object parameter (O 2 ), and returning nothing, that would only modify the internal representation of O's state; and
[0044] SInit ( 140 ), the set of the initial states of an object of O; the notion of initial state of O itself is not important to the invention (in one other embodiment the State Machine could be defined as SInit power NO, without any condition of correlation between objects); such set would typically be represented by a non empty set containing at most NS instances of the class of O (or a derived class O′ holding only one object instead of NO objects).
[0045] The association of Q, P 1 and P 2 constitutes an API ( 150 , 210 ) that third party code can leverage to signal events to O and measure their effects upon the states of its constituting objects. In a concrete system, an implementation I 1 of that API would be provided, that would realize the API. Various techniques of implementation exist for I 1 , some being entirely code based, that is, only relying on code to define the transitions, others consisting into an interpreter that leverages explicit transition tables stored as data.
[0046] The inputs of the transformation engine E ( 120 ) of the method of the embodiment are SSM 1 Set State Machines comprised of an interface API 1 that defines queries (Q), procedures (P 1 and P 2 ) as specified above, and the set of initial states SInit as defined above.
[0047] FIG. 3 is the general flowchart of the method of the developer embodiment. In an initial step, the customer application has created a Set State Machine SSM 1 by developing queries (Q) to objects, and procedures (P 1 , . . . Pn) corresponding to the customer application needs. It has also developed code (I 1 ) for implementing queries and procedures while manipulating the object states and their state transitions. SSM 1 , for Set State Machine 1 , applies to a collection of objects of a same type. For instance, if the customer application is for managing traveling containers, SSM 1 applies to all the traveling containers which all have a same behavior in terms of possible states and state transitions. The flowchart describes the steps of the method for optimizing space for states encoding for a collection of same type of objects.
[0048] In a first step ( 300 ) a designer identifies by reading the SSM 1 :
[0049] the natural Boolean variables that describe the object states; this is done by reading the queries Q such as “is the container in the ship?” defining the state “in the ship”;
[0050] the set of starting states, comprising at least one element (SInit); and
[0051] the transitions, that is the procedures of I 1 that modify object states, and identifying them as P 1 (involve one object state and one event) or P 2 (involve two object states and one event), etc.
[0052] In a second step ( 310 ), the computer automatically creates as many truth tables as the number of transitions times the number of Boolean properties. This program executes each procedure upon each state, using the queries to read the resulting state of each computation. For each computation, separating the Boolean properties of the resulting state provides one truth table per Boolean property.
[0053] In a third step ( 320 ) the computer executes a program for performing the transitive closure of the set of starting states defined in step 300 using the set of truth tables created in the preceding step ( 310 ). This program implements algorithms well known from prior art since it was mathematically established, under the graph theory that transitive closure allows converging to a set of reachable graph nodes. The transitive closure allows identifying all the reachable nodes. Applying the graph theory, one can map graph nodes to object states and graph paths to transitions. The list of reachable nodes correspond to the set of states which are related to one or more of the initial states and it is what we want to identify. This known property is interestingly used here in the context of minimizing the object states and transition encoding. The program ( 320 ) can be easily written, for instance, from the Floyd-Marshall algorithm referred in the web page http://en.wikipedia.org/wiki/Floyd-Warshall_algorithm. The inputs for this program are the set of starting states defined in step 300 and the set of truth tables created in step 310 . The output provides all the possible states that one object can reach starting from the initial states as defined.
[0054] It is noted that step 320 for computing transitive closure of initial object states uses as inputs the truth tables as defined in the preceding steps. Truth tables are the easiest way to represent the transitions. As known by the person skilled in the art, any equivalent logical memory representation, such as a graph, of these data could be used as input of a program computing the transitive closure of the initial object states. In the embodiment a truth table representation is used. In the rest of the flowchart describing the method of the embodiment a new set of truth tables is created ( 340 ) and used as input to the step for generating code implementing transitions ( 360 ). Even if any other representation of transitions could be used the truth tables are preferred because they are easier to leverage in the described algorithms.
[0055] At the end of execution of step 320 we have a list of object states which are the only object states that will be used in the following steps of the method. The resulting object states are the ‘possible object states’, a subset of the input object states. The initial object states and the transitions are the same as the input ones. Then the computer encodes the truth tables by first numbering ( 330 ) each state of the object set resulting from the execution of the preceding step ( 320 ). The states are numbered with binary numbers, starting at 0; this numbering can be done automatically by the computer at random; any other numbering is possible and the designer could optionally decide to impose a numbering by interrupting ( 335 ) the execution by the computer. As explained later in the document in reference with the description of FIG. 4 , the choice of how the object states are numbered has an impact on the execution time of the implementation of the API used by the customer application in the final Set State Machine SSM 2 . With the extension of the method, the numbering can be optimized to reduce processing time.
[0056] In step 340 when generating a new set of truth tables, the computer takes into account the numbers assigned to object states in step 330 . For each procedure p and each Boolean variable b, a truth table is determined by considering in turn for each state s 1 the state s 2 resulting of the application of p to s 1 as determined in step 310 , and then extracting the valuation of b in s 2 . If the number of bits needed to number the states according to step 320 is k times smaller than the initial number of Boolean variables needed to describe a state, then the new set of truth tables will count k times less tables than the set of truth tables resulting from step 310 .
[0057] The next step ( 350 ) includes performing a bitfield encoding of the set of objects of the collection of objects of a same type for which the states and transitions are considered by the method of the embodiment. The bitfield encoding is automatically performed by the computer on the object states resulting from the execution of the preceding steps. In any case, the bitfield encoding process comprises the following substeps:
[0058] counting the objects of the collection of objects which states must be tracked; let NO be the result;
[0059] giving a distinct number to each object, comprised between 0 inclusive and NO exclusive; and
[0060] allocating NB bitfields, each capable to hold at least NO bits; it is noted that, in an architecture that provides 64 bits integers like Java, if the number of objects is lesser than or equal to 64, 64 bits can be used; if the number of objects is greater than 64 an array needs to be allocated.
[0061] The bitfield encoding of the objects will improve the manipulation of objects as memory words by the processor and this will improve processing for accessing object states and transitions.
[0062] It is noted that as the bitfield encoding step ( 350 ) uses as input the object numbering which is defined at the customer application level, it can be performed at any time before execution of the following step ( 360 ) for generating code implementing the transitions even if it immediately precedes the step for generating code in the embodiment.
[0063] In the next step ( 360 ), the computer automatically generates the I 2 program which implements the transitions using one of the methods for implementing transitions described by truth tables well known by the person skilled in the art. Using one of the methods for implementing transitions described by truth tables as described into [Coudert 2001], implies implementing a near optimal transformation routine for each transition.
[0064] The method has delivered a new implementation for the transitions (I 2 ), that is efficient in terms of time, and that has saved space. Using the same API 1 than with SSM 1 , the resulting SSM 2 Set State Machine comprising the same API 1 and the I 2 implementation, the same API is provided to the customer application for accessing object states and transitions starting from the same starting states but in an optimized way from a space point of view.
[0065] FIG. 4A-4B is the general flowchart of FIG. 3 extended with steps with computer resource cost estimate computation for improving transition implementation (I 2 ). The flowchart in FIG. 4A starts by executing the steps ( 300 , 310 , 320 , 330 , 340 , 350 ) of the method of the embodiment for creating the truth tables corresponding to the objects states, transitions, and starting states identified by the designer up to the generation ( 360 ) of code implementing the transitions. Then the designer intervenes at this point of execution of the method to define ( 400 ) in the computer a cost function that weights each transformation depending on its relative contribution to the program efficiency in time. Given a (set of) client application(s) ( 100 ), the designer gives each query of Q and each procedure of P 1 and P 2 a weight that represents the relative importance of each of these queries and procedures in the the client applications. The obtained weighting t-uple constitutes a cost function for I 2 . Typically, the most often a procedure p is called at runtime, the higher its weight in the cost function, and the more important it is to lower p's computational cost, possibly at the expense of other procedures. Other cost functions can be drafted depending on the client application objectives. A new step is added wherein the computer calculates the cost estimate ( 410 ) based on the defined cost estimate function ( 400 ). In this step ( 410 ), the computer rates the I 2 routine in the preceding steps in terms of time efficiency; this can be done by counting bitfields operations, or by measuring them at runtime with a profiling tool; with those times and the cost function established in step 400 , the computer calculates a total cost for the states numbering at hand.
[0066] In FIG. 4B a loop starts on choosing one other possible numbering generated by the computer (answer No to test 430 ) and performing the following steps of the method ( 330 , 340 , 360 ) for generating the code implementing the transitions on the basis of the same bitfield encoding as chosen once ( 350 ) in the execution of the first steps of the method ( FIG. 4A ). The total cost is computed as described above with the new numbering function and the computer retains the I 2 transition implementation that minimizes the total cost ( 440 ). The loop can stop if a limit of computing period has been introduced in the computer and is reached (answer Yes to test 450 ). If no limit has been introduced or if the computing period is not over (answer No to test 450 ), the loop is re-executed ( 420 , 430 , 330 , 340 , 360 , 440 , 450 ) until there is no more numbering to be explored (answer Yes to test 430 ) or the computing period expires. In such both cases where there is no more numbering to explore (answer Yes to test 430 ) or the end of (reasonable) processing period is reached (answer Yes to test 450 ) the last best I 2 transition implementation code is retained; the computer has picked up the one that minimizes the total cost computed as described here; the method has delivered the same implementation as at end of the first execution of step 360 in FIG. 4A , but further optimized in time.
[0067] It is noted that the technique used to encode the objects states into the bitfields ( 340 ) could include, for instance the following: bit n of bitfield p, counting bits from right to left, holds the p-th bit of the state number of variable numbered n. Other encodings are possible (code bits from left to right, etc.), that are compatible with the invention, as long as they do not waste space; the transitions are implemented as bitfields bitwise arithmetic operations; for example, in Java, the logical AND between two bitfields would use the & operator on integer values.
[0068] Optimization techniques to implement the transitions ( 360 ) as those described by [Coudert 2001] use tri-states truth tables instead of pure Boolean values; this is compatible with the present invention, with a caveat: minimizing the number of necessary bitfields may require that strict Boolean valuation be used while performing the transitive closure of the states set.
[0069] Transitive closure computation ( 320 ) is a well-know problem and easily coded program.
[0070] Costs calculations ( 410 ) and code generators ( 360 ) to provide the transitions routine do not seem difficult to implement once the needed operations are identified, and the prior art [Coudert 2001] points to additional resources to code a program able to find a near optimal set of operations for each transition.
[0071] One example of code based upon an obvious situation would consist first in considering the ‘null’ and ‘not null’ natural states coded for eight objects numbered from 0 to 7, into 8 bit words. The initial state of a variable would be (false, true). The interesting transitions would be markAsNull and markAsNonNull. In natural states terms, the implementation (in Java pseudo code) would then be:
[0000] byte nullState = 0; byte notNullState = OxFF; markAsNull(int n) { /* n is the number of the considered object */ byte mask = 1 << n; nullState |= mask; notNullState &= ~mask; } markAsNotNull(int n) { /* n is the number of the considered object */ byte mask = 1 << n; notNullState |= mask; nullState &= ~mask; }
truth table for markAsNull and null is:
[0000] not null true false null true true true false true true
truth table for markAsNull and not null is:
[0000] not null true false null true false false false false false
truth table for markAsNotNull and not null is:
[0000] not null true false null true true true false true true
truth table for markAsNotNull and null is:
[0000] not null true false null true false false false false false
The transitive closure starting with (false, true) gives a set of two states:
[0000] (false, true) numbered 0 (true, false) numbered 1
We only need one variable to hold the resulting states: byte state=0; // initial value
The resulting truth table for markAsNull and null is:
[0000] null true true false true
The resulting truth table for markAsNotNull and null is:
[0000]
null
true false
false false
[0072] This simplistic example happens to keep one of the existing Boolean variables as the only needed one; more elaborate situations would typically lead to a new set of Boolean variables of which few if any would equate a variable of the initial set.)
[0073] And the transitions can be re-encoded as:
[0000]
markAsNull(int n) { /* n is the number of the considered
object */
state |= 1 << n;
}
markAsNotNull(int n) { /* n is the number of the considered
object */
state &= ~(1 << n);
}
This saves one byte, three bitwise operations (one ~, one &, one |) and
four assignments.
[0074] In the embodiment, the object states are expressed as a combination, a n-uple, of a fixed number of Boolean values. The objects states are represented as an element of a Cartesian product of Boolean variables. In the case where the natural encoding of object states is an element of the Cartesian product of variables that are each valued into sets of more than two values instead of Boolean variables, the invention still applies, because each of the the variables can be coded upon a Cartesian product of Boolean variables. More specifically, given a state representation V 1 XV 2 X . . . Vn of states in SSM 1 , step ( 310 ) for creation of truth tables would be modified as follows. For each Vi, let NVi be the number of values it can take, and NBVi be the minimal number of bits needed to store the binary representation of NVi. For each i, step 310 would number each value of Vi as a distinct valuation in the Cartesian product of Boolean variables bi 1 Xbi 2 X . . . biNBVi, then proceed normally upon the representation resulting from the substitution in V 1 XV 2 X . . . Vn of each Vi by its bi 1 Xbi 2 X . . . biNBVi equivalent, b 11 Xb 12 X . . . b 1 NBV 1 Xb 21 X . . . bnNBVn, which is itself a Cartesian product of Boolean variables. We returned to the previous in which the objects states are expressed as elements of a Cartesian product of Boolean variables. | A method, computer program and system, which, given a set of Boolean state variables, a set of state transitions described as truth tables for the the state variables, a set of initial states (that is states that objects happen to be in when they are brand new or when they are introduced into the system), all established by a natural modeling of the application domain, can derive an encoding that is provably isomorphic to the initial one but smaller, and transitions that match exactly the initial transitions but operating upon the new encoding, without incurring a significant time penalty. This effect is obtained by generating the extensive set of significant states, renumbering those states, then modifying the transitions implementation so as to use the renumbered states in place of the original ones. | 6 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Prov. Appln. Ser. No. 60/433,332 filed Dec. 13, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to improved processes for the production of ALVAC viruses using avian embryonic stem cells.
BACKGROUND OF THE INVENTION
[0003] Current process of production of ALVAC vaccines on chicken embryo fibroblasts (CEFs) involves handling hundreds of embryonated eggs. After embryo dissociation, the cells are seeded in roller bottles before infection. Typically, about 200 eggs are needed for infection of 120 roller bottles. The use of a continuous cell line growing in suspension would allow to suppress handling of eggs and to replace roller bottles by a 20-liter biofermentor. After optimization of culture conditions, one can expect to increase the cell density, and, consequently the final viral yields. One suitable cell line that could be used for such purposes would be a stable chicken embryo fibroblast derived cell line that grows in suspension.
[0004] Avian embryonic cell lines have been generated by several different investigators. For example, Pettite, et al. (North Carolina State Univ.; U.S. Pat. No. 5,340,740) relates to the development of avian embryonic stem cells by culturing avian blastodermal cells in the presence of a mouse fibroblast feeder layer. Pettite (U.S. Pat. No. 5,656,479; WO 93/23528) also describes and claims an avian cell culture of undifferentiated avian cells expressing an embryonic stem cell phenotype.
[0005] Samarut, et al. (Institut National de la Recherche Agronomique, et al.; U.S. Pat. No. 6,114,168; WO 96/12793) describes methods for producing avian embryonic stem cells on CEFs using particular media. Bouquet, et al. (Institut National de la Recherche Agronomique; U.S. Pat. No. 6,280,970 B1; patent application No. 2001/0036656 A1, published Nov. 1, 2001) describes transformed avian embryonic fibroblasts that contain SV40 T Ag within their genome. Samarut and Pain (patent application No. 2001/0019840 A1, pub. Sep. 6, 2001) relates to culture medium for producing avian ES cells and methods for producing proteins in ES cells cultured in such medium. And, Han, et al. (Hanmi Pharm. Co. Ltd.; WO 00/47717) describes the processes for developing avian embryonic germ cell lines by culturing avian primordial germ cells in culture medium containing particular growth factors and differentiation inhibitory factors.
[0006] Avian embryonic stem cells have been shown to be suitable for producing recombinant viruses. For example, Foster, et al. (Regents of Univ. Minnesota, U.S. Pat. Nos. 5,672,485; 5,879,924; 5,985,642; 5,879,924) describes methods for growing viruses in stable cell lines derived from chicken embryo fibroblasts.
[0007] Reilly, et al. (Board of Trustees operating Michigan State University; U.S. Pat. No. 5,989,805; WO 99/24068) relates to the use of chicken embryonic stem cells modified with a chemical mutagen to produce Marek's virus, swine influenza virus, equine influenza virus, avian influenza virus, avian reovirus, folwpox virus, pigeon pox, canarypox, psittacine herpesvirus, pigeon herpesvirus, falcon herpesvirus, Newcastle disease virus, infectious bursal disease virus, infectious bronchitis virus, avian encephalomyelitis virus, chicken anemia virus, avian adenovirus, and avian polyomavirus. Coussens, et al. (Board of Trustees operating Michigan State University; U.S. Pat. Nos. 5,827,738; 5,833,980) also relates to propagation of Marek's disease virus in embryonic stem cells. Bouquet, et al. (Institut National de la Recherche Agronomique; U.S. Pat. No. 6,280,970 B1; patent application No. 2001/0036656 A1, published Nov. 1, 2001) describes methods for producing viruses from avian embryonic fibroblasts transformed by incoporation of the SV40 T Ag within their genome.
[0008] There is a need in the art for improved processes for producing ALVAC-based vaccines. Provided herein is one such method that provides for production of ALVAC vectors using avian embryonic stem cell lines growing in suspension. The method provides both production and safety advantages. The significant aspects of the present invention are described below.
SUMMARY OF THE INVENTION
[0009] The present invention provides methods for propagating ALVAC viruses, preparing vaccines and providing vaccines to hosts by culturing an ALVAC virus in avian embryonic stem cells and harvesting the virus from the cells. Preferred cells are EB1 or EB14 cells. In certain embodiments, the virus has within its genome exogenous DNA encoding an immunogen that, upon expression within a host to whom the virus has been administered, results in a protective immune response.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1. Progressive adaptation of cells to DMEM/F12 medium.
[0011] [0011]FIG. 2. Cell culture analysis for Test 1.
[0012] [0012]FIG. 3. Additional cell culture analysis for Test 1.
[0013] [0013]FIG. 4. EB1 infection with vCP205
DETAILED DESCRIPTION
[0014] The present application provides novel methods for culturing ALVAC viruses on embryonic stem cells. All references cited within this application are incorporated by reference.
[0015] Poxvirus is a useful expression vector (Smith, et al. 1983, Gene, 25 (1): 21-8; Moss, et al, 1992, Biotechnology, 20: 345-62; Moss, et al, 1992, Curr. Top. Microbiol. Immunol., 158: 25-38; Moss, et al. 1991. Science, 252: 1662-1667). The canarypox ALVAC is a particularly useful virus for expressing exogenous DNA sequences in host cells. ALVAC-based recombinant viruses (i.e., ALVAC-1 and ALVAC-2) are particularly suitable in practicing the present invention (see, for. example, U.S. Pat. No. 5,756,103). ALVAC(2) is identical to ALVAC(1) except that ALVAC(2) genome comprises the vaccinia E3L and K3L genes under the control of vaccinia promoters (U.S. Pat. No. 6,130,066; Beattie et al., 1995a, 1995b, 1991; Chang et al., 1992; Davies et al., 1993). Both ALVAC(1) and ALVAC(2) have been demonstrated to be useful in expressing foreign DNA sequences, such as TAs (Tartaglia et al., 1993a,b; U.S. Pat. No. 5,833,975). ALVAC was deposited under the terms of the Budapest Treaty with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va. 20110-2209, USA, ATCC accession number VR-2547.
[0016] ALVAC has been demonstrated to be useful for expressing exogenous DNA sequences in host cells (see, for example, U.S. Pat. Nos. 5,756,102; 5,833,975; 5,843,456; 5,858,373; 5,863,542; 5,942,235; 5,989,561; 5,997,878; 6,265,189; 6,267,965; 6,309,647; 6,541,458; 6,596,279; and, 6,632,438). In practicing the present invention, ALVAC may be cultured in its native state or as a recombinant containing an exogenous DNA encoding a protein such as an antigen. Particularly useful antigens would include those derived from pathogens that cause disease in humans (i.e., a human pathogen) such as a bacterium, fungus, or virus, among others, or antigens derived from tumors (i.e., tumor or tumor-associated antigens). Many such antigens are known in the art and would be suitable in practicing the present invention. The ALVAC vector may also encode immune co-stimulatory molecules such as B7.1, among others. The invention further includes compositions containing ALVAC vectors in pharmaceutically acceptable diluents. The administration of such compositions to animal or human hosts in need of immunization is also contemplated.
[0017] In one embodiment, the present invention demonstrates that it is possible to produce ALVAC virus, on continuous, non-tumorigenic avian cells derived from avian embryonic stem cells. Suitable cells for such purposes have been described in, for example, U.S. Pat. Nos. 5,340,740; 5,656,479; 5,672,485; 5,879,924; 5,985,642; 5,989,805; 6,114,168; 6,280,970 B1; U.S. patent application Nos. 2001/0036656 A1; 2001/0019840 A1; and, international applications WO 93/23528; WO 96/12793; WO 99/24068; WO 00/47717; FR02/02945; and WO 03/07661). In certain embodiments, such cells include, for example, EB1, EB2, EB3, EB4, EB5, and EB14 cells (as described in FR02/02945 and WO 03/07661). These cells were obtained from chick embryos at very early steps of embryogenesis and exhibit a stem cell phenotype. The cells are not genetically modified in their native state and grow in suspension. In one embodiment, the cells are EB1 cells obtained from VIVALIS SA (France; FR02/02945 and WO 03/07661). In a second embodiment, the cells are EB14 cells obtained from VIVALIS SA (FR02/02945 and WO 03/07661). EB1 and EB14 cells are an early expansion of avian embryonic stem cells. Suitable cells such as these are included within the definition of the term “avian embryonic stem cell line” (“AES”). Any of such cells, along with other AES that are known in the art, may be suitable in practicing the present invention.
[0018] A better understanding of the present invention and of its many advantages will be had from the following examples, given by way of illustration.
EXAMPLES
Example 1
Material and Methods
[0019] A. Cells and virus
[0020] EB1 cells (2×50×10 E 6 cells) were received at p139 (May 2001) or p148 (July 2001) from Vivalis. The culture medium (Modified McCoy 5% and 0% SVF), was provided with the cells. All infections were performed using ALVAC vCP205 (ATCC No. VR-2557; U.S. Pat. No. 5,863,542; HIV expression cassette—vaccinia H6 promoter/HIV truncated env MN strain, I3L gag with protease in ALVAC C3 insertion site), #362, clarified (titer 7.9 logTCID50/ml), purified (sucrose cushion+gradient, titer 8.5 log TCID50/ml), or semi-purified (sucrose cushion, titer 9.2 logTCID50).
[0021] The genealogy of EB1 cells is shown below:
[0022] B. Processing of Infected Cells
[0023] Infected cells were harvested by centrifugation. Cell pellets were resuspended in {fraction (1/20)} to {fraction (1/20)} of the initial volume of the culture medium without serum, sonicated briefly in culture medium and centrifuged again to obtain the clarified lysate.
[0024] C. Viral Quantification
[0025] In order to study ALVAC DNA replication in viral preparations, we developed an ALVAC DNA quantitative PCR assay with the LightCycler™ apparatus. ALVAC DNA was purified and amplified in presence of SYBR Green Dye using primers specific for KIOR region, encoding structural VP8 protein. A standard curve, established from known concentrations of purified viral DNA, was used to estimate the viral DNA concentration in each sample. ALVAC DNA was quantified by QPCR on LightCycler, following SOP V100501/01 as described below:
[0026] A. Equipment: L2 class zone; Type II flow laminar hoods in 2 separated rooms with 2 different colors coats; LightCycler with a carousel (Roche Diagnistics Ref:2011468); capillaries (Roche Diagnostics ref: 1909339); centrifuge adapters (Roche Diagnostics ref:1909312); centrifuge (Eppendorf Ref:5415D); carousel centrifuge (Roche Diagnostics Ref:2189682); box with ice; thin wall 96 well plate model M (COSTAR Ref:6511); micro test tube, 1.5 ml (Eppendorf Ref:24077); 8 channel electronic pipette, 0.2-10 μl (BIOHIT ref:710200); barrier tips 10, 20, 50, 200, 1000 μl; and, 10, 50, 200, 1000 μl manual pipettes.
[0027] B. Products: ALVAC standard DNA, 5 tenfold dilutions: 20 to 200,000 copies; internal reference for extraction and quantification: ALVAC virus, 10 7 TCID50/ml (about 2×10 9 copies/ml); FastStart DNA Master SYBR Green I kit ((Roche Diagnostics ref:2239264); H 2 O, DNase and RNase free (PROMEGA Ref: P1193); samples: ALVAC DNA or ALVAC virus; primers CPK1011 (5 μM) and CPK1012 (5 μM) (see below):
[0028] C. Precautions: wear gloves; Master Mix and DNA dilutions must be performed in 2 different hoods; SYBR Green must be protected from light and conserved at 5° C.±1° C.; Adapters must be pre-cooled at 5° C.±1° C. in the cooling block.
[0029] D. Procedure:
[0030] Start Lightcycler: Before sample preparation, using the LightCycler software, select the program (FastStart 50° C.) and define the number of samples, and label properly.
[0031] Prepare master mix preparation (on ice):
[0032] Prepare the reaction mix under the first hood, on ice. Use 1.5 ml reaction tubes, and calculate the volume needed for 5 standard points, 1 negative point, 1 reference point and n+1 samples.
[0033] Add 60 μl of 1b tube to 1a tube. Mix by pipetting (do not vortex).
Products [Final] Volume (μl) H 2 O (Promega) 11.6 MgCl 2 4 mM 2.4 CPK1011/CPK1012 0.5 μM/0.5 μM 2 SYBR Green mix 1× 2
[0034] Put 18 μl of mix in each capillary. The cooling block is then transferred under the second hood.
[0035] DNA preparation:
[0036] On ice, dilute ALVAC DNA samples with DNase/Rnase-free H 2 O in micro tubes or in 96 well plate, in order to have less than 200,000 copies (estimated) by capillary.
[0037] Dilute ALVAC DNA standard from 200,000 to 20 copies (tenfold dilutions).
[0038] Dilute ALVAC reference DNA 100 fold.
[0039] In each capillary, add 2 μl of DNA template, or 2 μl of H 2 O in the negative sample. Seal the capillary with a plastic stopper. Centrifuge the adapters (which contain the capillaries) 30 sec in a centrifuge at 100 g and put the capillaries into the carousel. Place the carousel containing the samples in the LightCycler and close the lid.
[0040] Start the run.
[0041] Analyzed by LightCycler software
[0042] For quantification select analysis method:
[0043] Chose “Fits Points method”
[0044] Step 1 :chose “arithmetic base line”
[0045] Select standard samples
[0046] Step 2: adjust the noise band to eliminate the fluorescence background.
[0047] Step 3: adjust the cross line so that the error value is lower than 0.1, with a slope value between −3.3 and −4.0 (optimal theoretical value 3.4) and an intercept value between 30 and 40. At the optimal setting for the line, the calculated values of the standard should be closest to their known values.
[0048] For Tm analysis select melting curve analysis:
[0049] Step 1: select “linear with background” method
[0050] Select samples
[0051] Step 2: adjust the cursors at the beginning and at the end of the melting pea, respectively.
[0052] Step 3: select “manual Tm”: the software calculates the Tm for the sample.
[0053] Controls
[0054] Baseline fluorescence values should be close to zero for all samples
[0055] Two parameters allow validation of the standard curve. The first one is the error that should be below 0.1. The second one is the second-degree equation, with a slope value comprised between −3.3 and −4.0 (optimal theoretical value 3.4) and an intercept value between 30 and 40.
[0056] The melting curve of the PCR product allows to control the specificity of primers: Tm value is usually about 78±1° C. Specificity can also be controlled on agarose gel electrophoresis: only one product should be amplified, at 110 bp.
[0057] The internal reference is used to control the quality of DNA extraction.
[0058] Infectious titers were measured by a standard PFU assay.
Example 2
Growth Optimization for EB1 Cells
[0059] Prior to use, the cells were analyzed to optimize conditions for growth. As described above, EB1 cells were provided by VIVALIS in the specific modified medium McCoy-5% FCS. The influence of two parameters FCS (2.5% versus 5%) and C02 (0% versus 5%) on EB1 cell growth has been tested. Adaptation of the cells to DMEM-F12 medium has also been tested. For each condition, the generation time was calculated.
[0060] To carry out the tests, spinners were inoculated at an initial concentration of 10 4 cells/ml in the chosen conditions and incubated at 37° C. under agitation. As soon as the medium became acidic, cells were diluted to a concentration of 10 4 to 10 5 /ml in fresh medium. Cell viability was measured by Trypan blue exclusion. In each instance in which cell viability was too low (i.e.<70%), a Ficoll gradient was performed to eliminate dead cells (indicated by arrows A and C on the graphs).
[0061] Progressive adaptation of cells to DMEM/F12 medium was accomplished by progressively diluting the initial medium (McCoy medium) with DMEM/F12 (indicated by arrow C on the graph). Generation time (G) corresponds to the number of doublings (or generations) per day, and is calculated according to G=N/D, where D is the number of days of culture and N is the number of generations determined from the equation C f =C i ×2 N , C f and C i being respectively the final and initial cell concentrations.
[0062] The data has been obtained by cell numeration of non-infected cells, and presented as a function of initial density of cells. The results of these studies are summarized in FIG. 1 and Table 1.
TABLE 1 Initial cell density culture days Cells/ml (× 1000) 1 2 3 4-20 1.09 +/− 0.42 1.24 +/− 0.61 nd 20-100 1.4 +/− 0.14 1.05 +/− 0.21 1.18 +/− 0.17 100-500 1.15 +/− 0.27 nd 0.19 +/− 0.14
[0063] From these studies, it has been concluded that:
[0064] The mean doubling time of EB1 cells in suspension is about 1.1 generation/day;
[0065] There is no significant difference in growth curves when cells are cultivated in presence of 2.5 or 5% FCS.
[0066] The cells are sensitive to Ficoll gradient centrifugation, and conditions should be optimized.
[0067] The maximal density of cells we have reached in our conditions is about 800,000 cells/ml. At higher density, culture medium becomes acid, cell growth is stopped, cells undergo apoptosis and degenerate rapidly.
[0068] EB1 cells can be grown as suspensions in standard DMEM-F12 medium containing 2.5% FCS, with an average doubling time of about 1 generation per day.
[0069] The maximum cell density in spinner is between 5×10 5 and 10 6 cells/ml, but culture conditions in a biogenerator may be useful for increasing the biomass.
Example 3
Infection of EB1 Cells in Spinner
[0070] A. Test 1
[0071] 100 ml of EB1 cells (P138) in DMEM-F12-0% FCS (initial density: 4×10 5 cells/ml) were incubated for 1 h at 37° C. with a clarified preparation of ALVAC-HIV vCP205 (m.o.i 0.1). The culture was then diluted with an equivalent volume of modified McCOY5A-5% FCS (final cell density: 2×10 5 cells/ml), and incubated at 37° C. under agitation (spinner) and 5% CO 2 . Both cell fraction and culture fluid were collected at 48 and 96 hours p.i., and analyzed for infectious virus (PFU assay on CEPs) and viral DNA content (qPCR). At each time point, 20 ml of the culture were analyzed. After centrifugation, the supernatant fraction (S) was collected and directly used for quantification. The pellet, corresponding to the cell fraction (C) was re-suspended in 1 ml (1:20 of initial volume) of Tris 10 mM pH9, before sonication and quantification. The titers are expressed per ml (left column) or per fraction (right column). The total viral material produced in the spinner was calculated by adding the 2 fractions: Total=(S/ml×200)+(C/ml×10). The total value per ml was obtained by dividing this result by 200. The results of this test are shown in Table 2.
TABLE 2 spinner 48 h spinner 96 h /ml /fraction /ml /fraction Log GEQ cell fraction 6.25* 7.55 5.76* 7.07 supernatant 4.75 7.04 6.42 8.72 Total 5.37 7.67 6.43 8.73 GEQ/cell 1.2 13.4 Log PFU cell fraction 4.95* 6.25 4.94* 6.25 supernatant 4.30 6.60 6.26 8.56 Total 4.45 6.75 6.27 8.57 PFU/cell 0.14 9.3
[0072] B. Test 2
[0073] 22.5 ml of cells (P138) in suspension in DMEM-F12-0% FCS (initial density: 5.6×10 5 cells/ml) were incubated for 30 min. at 37° C. with a clarified preparation of ALVAC-HIV vCP205 (m.o.i 0.1). The culture was then diluted with an equivalent volume of modified McCOY5A-5% FCS (final cell density: 2.8×10 5 cells/ml), and incubated at 37° C. under agitation (spinner) and 5% CO 2 . Both cell fraction and culture fluid were collected at 50, 74 and 96 hours p.i., and analyzed for infectious virus (PFU assay) and viral DNA content (qPCR). Cell culture analysis was performed as described for Test 1, above. Results of this test are summarized in Table 3.
TABLE 3 50 hours 74 hours 97 hours /ml /fraction /ml /fraction /ml /fraction Log GEQ Cell fraction 6.89* 7.54 7.15* 7.80 7.31* 7.97 supernatant 6.05 7.70 6.54 8.20 6.96 8.61 total 6.28 7.93 6.69 8.35 7.05 8.70 GEQ/cell 30.4 80 179 log PFU Cell fraction 6.40* 7.05 6.37* 7.02 5.99* 6.64 supernatant 5.56 7.21 5.8 7.45 6.29 7.94 total 5.78 7.44 5.94 7.60 6.31 7.96 PFU/cell 2.2 3.2 7.2
[0074] C. Test 3
[0075] EB1 cells at p148 were infected in a minimal volume (5 ml) of modified McCOY 5A medium −0%FCS at an m.o.i. of 0.1, and diluted at a final density of 1.5×10 5 cells/ml in 200 ml of modified McCoy medium 2% FCS. The experiment was done in duplicate (spinners A and B), cells were infected with semi-purified (sucrose cushion, spinner A) or purified (sucrose cushion+gradient, spinner B) preparations of vCP205 (#363). Both viral DNA and infectious virus were quantified in the cell fraction and in the supernatant of infected cells at time-points 24, 48, 72 and 116 h. P.I. No significant differences were obtained between spinner A and spinner B. Cell culture analysis was performed as described for Test 1, above. Results of this test are summarized in Tables 4 and 5 as well as FIGS. 2 and 3. Cell viability was also measured in parallel, as shown in FIG. 4.
TABLE 4 × 10E6 cells/ml cell number % cells hours p.i. A B Mean A B mean 0 31.4 31.4 31.4 100.0 100.0 100.0 24 38 42 40 121.0 133.8 127.4 48 30.2 27 28.6 96.2 86.0 91.1 72 20 20.6 20.3 63.7 65.6 64.6 116 2.75 2.75 2.75 8.8 8.8 8.8 24 8 72 116 /frac- /frac- /frac- /frac- /ml tion /ml tion /ml tion /ml tion spinner A log GEQ cell fraction 5.93 7.23 5.97 7.27 7.28 8.58 6.89 8.19 supernatant 4.8 7.1 6.03 8.33 6.39 8.69 6.18 8.48 GEQ total 5.17 7.47 6.07 8.27 6.64 8.94 6.36 8.66 GEQ/cell 0.9 7.4 27.7 14.6 log PFU cell fraction 5.9 7.2 5.7 7 6.13 7.43 6.60 7.9 supernatant 4.4 6.73 5.9 8.21 5.6 7.86 5.60 7.89 PFU total 5.43 6.73 5.91 8.21 5.56 7.86 5.59 7.89 PFU/cell 0.2 5.2 2.3 2.5 spinner B log GEQ cell fraction 5.86 7.16 6.07 7.38 7.19 8.49 6.99 8.29 supernatant 4.82 7.12 5.67 7.97 6.21 8.51 6.43 8.73 GEQ total 5.14 7.44 5.77 8.07 6.50 8.80 6.56 8.66 GEQ/cell 0.9 3.7 20.1 23.3 log PFU cell fraction 5.56 6.86 5.91 7.21 6.19 7.49 6.50 7.8 supernatant 5.3 7.56 5.84 8.14 5.2 7.5 5.50 7.81 PFU total 4.26 7.56 5.84 8.14 5.20 7.50 5.51 7.81 PFU/cell 1.2 4.4 1.0 2.1
[0076] [0076] TABLE 5 mean values spinners [A, B]/ml 24 h 48 h 72 h 116 h /frac- /frac- /frac- /frac- /ml tion /ml tion /ml tion /ml tion Log GEQ cell fraction 5.90* 7.20 6.02* 7.33 7.24* 8.54 6.94* 8.24 supernatant 4.81 7.11 5.85 8.15 6.30 8.60 6.31 8.61 GEQ total 5.16 7.46 5.92 8.22 6.57 8.87 6.46 8.76 GEQ/cell 0.91 5.6 24 19 log PFU cell fraction 5.73* 7.03 5.81* 7.11 6.16* 7.46 6.55* 7.85 supernatant 4.85 7.15 5.87 8.18 5.40 7.68 5.55 7.85 PFU total 4.84 7.15 5.87 8.18 5.38 7.68 5.55 7.85 PFU/cell 0.4 4.8 1.5 2.3
[0077] D. Infections in Static Conditions, Without Agitation (Flasks)
[0078] 75 cm culture flasks were seeded with 3×10 6 cells in a total volume of 50 ml of DMEM-F12 without FCS, and infected with vCP205 at an m.o.i. of 0.1 for 48 hours at 37° C., under 5% C0 2 . Culture fluids and cell fractions were collected and infectious virus (PFU assay) and viral DNA (qPCR) were quantified. The results of this test are summarized in Table 6 and FIG. 4.
TABLE 6 F75 n°1 F75 n°2 F75 n°3 F75 n°4 /frac- /frac- /frac- /frac- /ml tion /ml tion /ml tion /ml tion Log GEQ cell fraction 6.41* 6.41 6.37* 6.37 6.43* 6.43 6.37* 6.37 supernatant 6.24 7.94 6.28 7.97 6.26 7.95 6.25 7.94 total 6.25 7.95 6.28 7.98 6.26 7.96 6.25 7.95 GEQ/cell 30 32 30 30 Log PFU cell fraction 4.37* 4.37 4.31* 4.31 4.43* 4.43 4.52* 4.52 supernatant 4.45 6.15 4.61 6.31 4.43 6.13 4.33 6.03 total 4.46 6.16 4.61 6.31 4.44 6.14 4.34 6.04 PFU/cell 0.5 0.7 0.5 0.4
[0079] The following conclusions have been reached from this study:
[0080] Viral yields are higher when cells are cultivated in spinners instead of flasks (mean value: 5 PFU/ml versus 0.5 PFU/ml);
[0081] Mean PFU titer/cell: 6.3 (vs 2.5 TCID50/cell for CEPs grown virus as determined from the mean value calculated from vCP205 #S3317, #S3292, #3124, #LST011 and #LP012);
[0082] Mean GEQ titer per cell: 105 (vs125 GEQ/cell for CEPs grown vCP205). As a comparison, the viral yield in chick embryo fibroblasts (CEPs) is routinely about 2.5 TCID 50 /cell (5 to 20 PFU), corresponding to 125 GEQ/cell;
[0083] In McCoy Medium: DMEM/F12 (1:1) 2.5% FCS, maximal titer (both infectious and genomic) is reached between 72 and 97 hours p.i. In McCoy Medium 2.5% FCS, genomic titer increases until 116 h. p.i., while infectious titer is stable at 48 h.p.i.;
[0084] in Tests 1 and 2, the virus is mainly recovered from the cell culture supernatant, which is most likely a consequence of cell lysis;
[0085] EB1 cells replicate ALVAC vCP205 at similar yields than CEPs; and,
[0086] With no optimization, based on a viral yield of 6 PFU/cell and a cell density of 5×10 5 cells/ml, a standard production process of 120 roller bottles could be replaced by one 20-liter biogenerator.
[0087] While the present invention has been described in terms of the preferred embodiments, it is understood that variations and modifications will occur to those skilled in the art. Therefore, it is intended that the appended claims cover all such equivalent variations that come within the scope of the invention as claimed. | The present invention relates to methods for producing ALVAC virus on avian embryonic stem cells and compositions comprising ALVAC virus made using such methods. | 0 |
INTRODUCTION
[0001] The present invention relates to a bearing assembly for mounting an actuator to an aircraft wing and to an actuator system assembly comprising the bearing assembly of the invention and the actuators.
BACKGROUND
[0002] Aircraft need to produce varying levels of lift for take-off, landing and cruise. A combination of wing leading and trailing edge control surfaces are used to control the wing coefficient of lift. The leading edge control surface is known as a slat and a trailing edge control surface is known as a flap. During normal flight the slats and flaps are retracted against the leading and trailing edges of the wing, respectively. However, during take-off and landing they are deployed from the wing so as to vary the airflow across and under the wing surfaces. By varying the extent to which the slats and flaps are deployed from the wing, the lift provided by the wing can be controlled. Other trailing edge control surfaces include ailerons and spoilers.
[0003] The control surfaces are moved using hydraulic actuators mounted within the wing structure and coupled at each end to the wing and to the control surface via spherical bearing assemblies at both ends of the actuator.
[0004] As demands for thinner, more efficient wing profiles increase, it becomes increasingly difficult to fit all the necessary systems, structure and actuation devices within the wing outer mould line and the size of actuator that may be employed for controlling deployment of various control surfaces is severely limited. In particular, the length of conventional hydraulic cylinders is a problem, especially as the spherical bearing at each end of the actuator each add between 50 to 200 mm to the length of the actuator which is often unacceptable due to the tight space constraints within the wing structure.
[0005] To address the problems referred to above, it is known to employ trunion mounted cylinders as these are shorter in length. However, as these actuators rely on only one spherical bearing at the moving end of the hydraulic cylinder, the fixed end of the actuator is mounted for movement about one axis, and so they suffer from high wear on the cylinder bushes and seals resulting in premature failure due to hyperstatic loading caused by wing bending and manufacturing tolerances. Therefore, regular inspection and maintenance is necessary to avoid a potential failure.
[0006] It is therefore desirable to provide an assembly in which the actuator is mounted via a spherical bearing at both ends but which does not have the additional length suffered by conventional bearing assemblies. Embodiments of the present invention therefore seek to provide an actuator which substantially overcomes or alleviates the known problems with conventional bearing assemblies and to provide an actuator of reduced length that can withstand hyperstatic loads caused by wing bending.
SUMMARY OF THE INVENTION
[0007] According to the invention, there is provided a bearing assembly for mounting a pair of spaced parallel actuators between a wing and a control surface of an aircraft so that the actuators control deployment of said control surface from the wing in tandem, the bearing assembly comprising a fixed member for attachment to the aircraft and a movable member attachable to the actuators, wherein the fixed and movable members are coupled via a part-spherical bearing and are configured such that the part-spherical bearing is located in the space between the actuators.
[0008] Each actuator may comprise a hydraulic cylinder and a piston slideably received in the cylinder. The bearing assembly preferably comprises a first movable support member attachable to the hydraulic cylinders to couple each actuator together in spaced parallel relation, said first movable support member including a shaft that extends across the space between the cylinders and a first part-spherical bearing being mountable to said shaft.
[0009] In a preferred embodiment, a first fixed support member comprises an arm that extends into the space between the cylinders, the arm having an opening that forms a bearing seat to receive the first part-spherical bearing mounted on the shaft of the first movable support member such that the fixed and movable support members are rotatable relative to each other about the first part-spherical bearing.
[0010] The arm of the first fixed support member may be formed in two separable parts that combine to form the bearing seat and enclose the first part-spherical bearing.
[0011] In one embodiment, the first fixed support member has a flange at one end remote from the bearing seat, the flange having means to enable the arm to be fixed to the aircraft.
[0012] Preferably, the first movable support member comprises a collar at each end of the shaft to receive a cylinder of each actuator in respective collars.
[0013] A reinforcing plate may be coupled to, and extend between, each collar.
[0014] In a preferred embodiment, a second movable support member is attachable to the free end of each piston extending from their respective cylinders such that the pistons slide in unison into and out of their respective cylinders.
[0015] The second movable support member may have a central region that extends between the pistons and an aperture extending through said central region to receive and mount a second part-spherical bearing between said pistons.
[0016] The central region preferably has a hole in the central region to receive and mount a pin extending laterally through the aperture, the second part-spherical bearing being mountable on the pin.
[0017] In a preferred embodiment, a second fixed support member comprises an arm configured to extend into the aperture in the central region of the second movable support member, the arm having an opening that forms a bearing seat to receive the second part-spherical bearing mounted in said aperture in the second movable support member such that the second fixed and movable support members rotate relative to each other about the second part-spherical bearing.
[0018] The arm of the second fixed support member may be formed in two separable parts that combine to form the bearing seat and enclose the second part-spherical bearing.
[0019] Preferably, the second fixed support member has a flange at one end remote from the bearing seat, the flange having means to enable the arm to be attached to the aircraft.
[0020] In a preferred embodiment the bearing assembly comprises a manifold to fluidly connect a single fluid source to both cylinders. Preferably, a separate manifold is mountable at each end of the pair of cylinders.
[0021] The ends of each cylinder may be closed by a plate and the manifold is attachable to the plates at one end of the pair of cylinders so as to extend therebetween, the plates each having a passage therethrough to fluidly connect the manifold to the cylinders.
[0022] According to another aspect of the invention, there is provided an actuator system comprising the bearing assembly of the invention, the actuator system comprising a pair of spaced parallel cylinders each having a piston slideably received therein, a first movable support member being mounted to said cylinders and having a first part spherical bearing mounted on a shaft extending therebetween, a first fixed support member being coupled to said first part spherical bearing such that the first fixed and movable support members are rotatable relative to each other about said first part-spherical bearing.
[0023] In a preferable embodiment, the second movable support member is mounted to the free end of each piston and a second part-spherical bearing is mounted in the aperture in the central region of said second movable support member, the second fixed support member extending into said aperture and being coupled to the second-part spherical bearing such that the second fixed and movable support members are rotatable relative to each other about the second part-spherical bearing.
[0024] In one embodiment, a spring element is disposed in each cylinder to bias the pistons to a neutral position in the absence of hydraulic pressure acting on the pistons.
[0025] In one embodiment, the first fixed support member is mountable to an aircraft wing and the second fixed support member is mountable to a control surface.
[0026] In another embodiment, the first fixed support member is mountable to a control surface and the second fixed support member is mountable to an aircraft wing.
[0027] According to another aspect of the invention, there is provided an aircraft wing and a control surface coupled to said wing for deployment during take-off and/or landing, and an actuator system according to the invention extending between and coupled to said control surface and the wing to control deployment of said control surface from said wing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:
[0029] FIG. 1 is a front perspective view of an actuator system assembly according to the invention, including the bearing assembly of the invention, with the pistons of the hydraulic cylinders shown in a retracted state;
[0030] FIG. 2 is a rear perspective view of the actuator system of FIG. 1 ;
[0031] FIG. 3 is a front perspective view of the actuator system shown in FIG. 1 , but with the pistons of the hydraulic cylinders shown in their extended state; and
[0032] FIG. 4 is an exploded perspective view of the actuator system shown in FIGS. 1 to 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Referring now to the drawings, there is shown in FIGS. 1 and 2 an actuator system assembly 1 including a bearing assembly according to a preferred embodiment of the invention. The actuator system assembly 1 comprises a pair of spaced hydraulic cylinders 3 whose longitudinal axes (A-A in FIG. 4 ) are arranged parallel to each other. Each cylinder 3 comprises a cylinder housing 4 with a piston 5 (see FIG. 4 ) slideably received in the cylinder housing 4 to drive a control surface (not shown) towards and away from an aircraft wing (not shown) as the piston 5 slides into and out of the cylinder housing 4 in response to changes in hydraulic pressure on one side of the piston 5 . Each piston 5 has a shaft 6 that extends through a plate 7 closing an end of each cylinder housing 4 .
[0034] Referring to the bearing assembly, it comprises a first movable support element 8 having a pair of collars 9 spaced from each other by a shaft 10 , which is just visible in FIG. 4 between the collars 9 . The collars 9 are sized so as to receive and mount hydraulic cylinder housings 4 close to one end, and with their longitudinal axes (A-A in FIG. 4 ) parallel to each other. The longitudinal axis of the shaft 10 (B-B in FIG. 4 ) intersects and extends perpendicular to the longitudinal axis A-A of each cylinder housing 4 . The collars 9 and shaft 10 are all rigidly connected together and/or integrally formed so that there is no relative movement between them. The cylinders 4 are therefore held in fixed relative positions by the collars 9 . To further reinforce and maintain the relative positions of the cylinders 4 , two plates 12 extend between and are connected directly to the collars 9 at each end by screws 13 .
[0035] A first part-spherical bearing element 14 has inner and outer race portions 14 a , 14 b . The inner race portion 14 a is received on the shaft 10 and the outer race portion 14 b is seated within an aperture 15 formed in an arm 17 of a first fixed support member 18 that has a flange 19 with apertures 20 for attaching the first fixed support member 18 to a structural part of a wing of an aircraft using bolts inserted through said apertures 20 . Therefore, the first movable and fixed support members 8 , 18 are coupled so that they can rotate relative to each other about the first part-spherical bearing 14 .
[0036] It will be noted that the first fixed support member 18 may be formed in two parts 18 a , 18 b that attach to each other and together form the aperture 15 that encloses the first part-spherical bearing 14 . The two parts 18 a , 18 b may be coupled using bolts 21 a that locate in hollow dowels 21 in the arm 17 for accurate alignment between the two parts 18 a , 18 b . The bolts pass through the dowels 21 into the threaded arm 17 to provide purely a clamping force. It will be appreciated that the first spherical bearing 14 is located between the cylinders 4 and so does not contribute to an increase in the overall length of the assembly 1 .
[0037] It is possible for only one end of the assembly 1 to be provided with a spherical bearing assembly of the invention that does not contribute to the overall length of the assembly to the same extent as a conventional assembly would. However, in a preferred embodiment, both ends of the system are equipped with a bearing assembly of the invention in which a part-spherical bearing is mounted and positioned between the cylinders 4 so as to provide maximum reduction in the overall length of the assembly. In this case, the bearing assembly further includes a second movable support member 25 which is attached to the ends of both pistons 6 using, for example, bolts 26 . The pistons 5 are therefore constrained so that they slide in unison into and out of their respective cylinders 4 .
[0038] The second movable support member 25 has a central region 27 that extends inwardly towards the cylinders 4 between the piston shafts 6 . A generally rectangular shaped aperture 28 extends through the central region 27 in the same direction as the longitudinal axis A-A of the cylinders 3 . A hole 28 also extends laterally, at right-angles to the longitudinal axis A-A, through the central region 27 , intersecting the aperture 28 .
[0039] A second fixed support member 29 has an arm 30 with an aperture 31 in which is received a second part-spherical bearing 32 having inner and outer bearing races 32 a , 32 b . The arm 30 may be formed in two parts 30 a , 30 b which together combine to form the aperture 31 and enclose the second part-spherical bearing 32 . The two-parts of the arm 30 may be connected together using bolts 33 . that locate in hollow dowels 33 a in part 30 b for accurate alignment between the two parts 30 a , 30 b . The bolts 33 pass through the dowels 33 a into the threaded part 30 b to provide purely a clamping force.
[0040] Once the second part-spherical bearing 32 has been located in the arm 30 with the outer bearing race 32 b seated in the aperture 31 , the arm 30 is inserted through the rectangular shaped aperture 28 in the central region 27 of the second movable support member 25 so that the second part-spherical bearing 32 is positioned in the aperture 28 in the central region and aligned with the holes 28 . A pin 33 b having a hollow female threaded shaft 34 is then inserted through the holes 28 and second part-spherical bearing 32 and retained in place by a plug 35 having a threaded male shaft 35 a . The female thread in the shaft 34 is engaged with the male thread on the shaft 35 a . The two components together act as one but are expected to fail individually and so act as a failsafe pin arrangement. The inner race 32 a is thereby mounted on the shaft 34 and the second part-spherical bearing 32 is mounted in position within the aperture 28 of the central region 27 between the ends of the piston shafts 6 . Consequently, the second movable and fixed support members 25 , 29 are now connected via the second part-spherical bearing 32 so that they can rotate relative to each other about the second part-spherical bearing 32 . It will be appreciated that the arm 30 is a relatively loose fit in the rectangular shaped aperture 28 so that there is sufficient clearance to enable relative rotation between the second movable and fixed support members 25 , 29 through a limited angular range of movement.
[0041] The second fixed support member 29 has a flange 34 at the free end of the arm 30 remote from the aperture 28 that receives the second part-spherical bearing 32 to enable the second fixed support member 29 to be attached to a control surface of an aircraft using bolts that extend through apertures 35 in the flange 34 .
[0042] The cylinders 3 are configured so that they operate in tandem and so that the piston 5 associated with each cylinder housing 4 moves by exactly the same amount. Rigid twinning of the two cylinders 4 ensures that any asymmetry is eliminated or reduced. However, it is also envisaged that front and rear balance manifolds can be utilised to ensure that cylinders 4 do not fight each other and pressure equalisation is maintained. The use of a balanced manifold could also provide faster actuator response times.
[0043] With reference to the drawings, a manifold 36 is attached to each end of the cylinder housing 4 . Each manifold 36 has a fluid flow conduit therethrough to connect both cylinder housings 4 to a single fluid supply pipe 37 attached to each manifold 36 . This ensures that exactly the same amount of fluid is pumped into, and withdrawn from, each cylinder housing 4 . Movement of the pistons 5 may be monitored using a linear velocity displacement transducer (LVDT). If two LVDT's are used, feedback on each piston position can be obtained through a comparator. The comparator may be configured to actuate a shut-off valve in the event of any asymmetry between the cylinders 3 . Alternatively, LVDT's could inform a twinned servo valve arrangement so that corrections are made on a continuous basis.
[0044] In one unillustrated modified embodiment, a spring may be located in each cylinder housing 4 to bias the pistons 5 to a neutral position in the absence of hydraulic pressure acting on the pistons 5 .
[0045] It will be appreciated that as at least one spherical bearing element 14 , 32 is now disposed between a pair of cylinders 3 , rather than protruding from one end of the assembly. Therefore, the overall length of the actuator system 1 is reduced providing more design flexibility. Although the width of the actuator 1 is increased as a result of employing two cylinders 3 in side-by-side relation, the space in the across-wing direction is of less concern and so this is considered to be an acceptable compromise with the two cylinders 3 being more easily accommodated within the wing.
[0046] Reference is made above to movable and fixed support members. Movable support members are those that are coupled to and move together with the cylinders 3 , whereas the fixed support members are those that are coupled to the aircraft structure or control surface.
[0047] It will be appreciated that the foregoing description is given by way of example only and that modifications may be made to the support assembly of the present invention without departing from the scope of the appended claims. | A bearing assembly for mounting a pair of spaced parallel actuators ( 3 ) between a wing and a control surface of an aircraft so that the actuators control deployment of said control surface from the wing in tandem is disclosed. The bearing assembly comprises a fixed member ( 18 ) for attachment to the aircraft and a movable member ( 8 ) attachable to the actuators. The fixed and movable members are coupled via a part-spherical bearing ( 14 ) and are configured such that the part-spherical bearing is located in the space between the actuators ( 3 ). | 5 |
DESCRIPTION
This invention relates to a control for the automatic replacement of the lower thread bobbin for sewing machines, whereby mechanical pliers are sequentially actuated to remove a lower thread empty bobbin from its operating seat, unload the thread empty bobbin and replace it with another thread-loaded bobbin, taken from a special loading cartridge, wherein a plurality of said loaded bobbins is located. As is known, at present lower thread bobbins must be replaced by hand when they are empty. Because of the technical requirements which oblige said bobbin to be of a limited size, it is obvious that the amount of wound thread is proportionally limited. As a consequence, the replacement of empty bobbins by loaded bobbins is rather frequent.
Such operation, besides being complicated and uneasy, involves the standstill of the machine, the intervention of the operator for the replacement with ensuing periodical interruption of the working cycle and the obvious limitation of the real production possibilities within the frame of the industrial utilization for cloth-making and the like.
The object of this invention is to eliminate the above drawbacks. The invention, as is characterized by the claims, solves the problem by means of an automatic control of the lower thread bobbin for sewing machines, in particular for machines for industrial use for cloth-making and the like, by which invention the following results are obtained: on each sewing machine a loading cartridge is provided wherein a set of capsules is located containing bobbins loaded with wound thread; a device sliding transversely and longitudinally is aligned with the loading cartridge, which device carries a pliers; the movement device causes the above pliers to shift and align automatically in several positions, in alignment and sliding with the seat of the capsule, the collection basket, the loading cartridge, so that the automatic replacement is sequentially obtained of the capsule with a loaded bobbin directly in the sewing machine; the shifting of the handling means is coordinated through programmable electronic control devices. The advantages achieved by this invention lie essentially in that all the sliding, shifting, loading and unloading motions are fully automatic and take place in a rapid, precise and autonomous manner, with no need for hand operations, with part reduction of the operating times; such automation allows improvement of the working activity of industrial and non industrial sewing machines, utilized for the working of mass produced products for clothing and the like. Another advantage is that the operators can manage more easily several machines at the same time, while the loading cartridge can be preloaded, even in another location, and put at the disposal of said operators, who replace them only upon exhaustion of the capsule with full bobbins loaded on the same and utilized gradually during the sewing operating stages.
The invention is described in detail in the following according to a particular embodiment, proposed only by way of non limitative example, with reference to the attached drawings, wherein:
FIG. 1A shows a plan view of a mechanical pliers;
FIG. 1B shows a front view of a mechanical pliers;
FIG. 2 shows a front view of a seat for cartridges for loading capsules with lower thread bobbins, complete with said cartridge;
FIG. 3 shows the plan view of the same seat and the same cartridge of FIG. 2;
FIG. 4 shows the front view of a complete control applied to a sewing machine, and
FIG. 5 shows the side view of the same control of FIG. 4.
The figures illustrate a control for the automatic replacement of the lower thread bobbin for sewing machines, in particular for industrial sewing machines, substantially comprising a mechanical pliers (1) whose mobile arm (2) is activated by means of a piston (3). In particular, and by way of non limitative example, piston (3) is of the pneumatic type, as is the device for the sliding handling, which is formed by a couple of pistons (4) (4') vertically oriented on the side of a sewing machine (5), in alignment with the part of operating head comprising the dog and the cloth-presser foot.
In the embodiment illustrated by way of example, the handling comprises two pistons (4) and (4'), whose function is to support and cause the sliding of the support structure (6) on which a runner (7) activated by a piston (8) can freely slide orthogonally.
It must be stressed that the handling with the aforementioned pneumatic pistons has been illustrated and described according to a preferred embodiment from both the economic and functional point of view. In particular the coupling of pistons (4) and (4') has been used to restrain the stroke of the individual details. In any case, the above solution has been proposed only by way of non limitative example; in fact, handling may also be obtained by other known means of a mechanical, hydraulic, electromechanical, mixed nature or the like. In its vertical sliding the whole is kept regularly on line by means of a transverse carriage (9), which comprises two side supports (10) which run along vertical guides (11).
To runner (7) a supporting plate (12) is coupled to which the fixed part of the mechanical pliers (1) is connected. During operation of the sewing machine (5), a capsule (13) containing a lower thread bobbin (14) is engaged in its own seat (15) under the operating head.
When the thread wound on bobbin (14) ends, sewing stops and said bobbin must be replaced by a thread loaded bobbin.
The stopped feed of the lower thread causes the start of the operating stage of the invention, controlled by means of a programmable electronic device (31) (illustrated in FIG. 4 only) which acts on the electrovalves that activate pistons (3), (4), (4') and (8), regulating the stroke and the alignment in the required positions by means of proximity sensors, optical sensors or sensors of other suitable types, and/or by means of ends-of-stroke. Pistons (4) and (4') extend sequentially their frames until they lift the support structure (6) up to such a height as to coaxially align pliers (1) with the upper axis (16), corresponding to the axial position of capsule (13) with bobbin (14) without thread, positioned on seat (15). (Position A).
Now steps in piston (8) which, from the resting position pushes forward runner (7) until the mechanical pliers (1), applied at the top of the supporting plate (12) is brought in substantial contact with the front part of capsule (13), engaged in its own seat (15).
Piston (3) steps in causing the rotation of the mobile arm (2), until its spout-end (17) engages with the mobile lever (18) of capsule (13).
Said lever (18), as is known, hooks stably the empty bobbin (14), so that the following backwards movement of piston (3) up to its resting position causes the removal of both the bobbin and the capsule from seat (15), and their lasting connection with said mechanical pliers.
In the following stage, pistons (4) (4') re-enter, until the mechanical pliers (1) is brought in alignment with a basket (19) where, after a forward movement of runner (7) and the opening of the mobile arm (2), both the empty bobbin and the corresponding capsule are put down. (Position B).
Runner (7) is caused again to move backwards up to the end-of-stroke, and pistons (4), (4') extend again, bringing this time the mechanical pliers (1) into coaxial alignment with the restraining seat of a cartridge (21) loading capsules (13) with bobbins (14) loaded with wound thread. (Position C).
Piston (8) again pushes forward runner (7) until the mechanical pliers (1) is in substantial contact with the front part of the first capsule (13), with the related loaded bobbin (14) located in cartridge (21).
The rotation of the mobile arm (2) of pliers (1), induced by piston (3), causes the hooking of the aforementioned first capsule (13) with the related bobbin (14) to spout (17) of said arm.
Once hooking has taken place, piston (8) again causes runner (7) to move backwards up to the end-of stroke, pistons (4) (4') extend until the mechanical pliers (1) is coaxially realigned with seat (15) of the sewing machine (Position A), piston (8) causes runner (7) to move forward until the loaded bobbin (14) with the related capsule (13) is inserted in said seat, piston (3) causes the backward rotation of the mobile arm (2), with ensuing unhooking from said bobbin and said capsule and lastly runner (7) is repositioned at the end of stroke, together with pistons (4) (4'), which are lowered to a resting position (Position D), while the sewing machine restarts it operation.
The loading cartridge (21) is substantially constituted by a horizontal external box-shaped body (22) wherein a longitudinal pin (23) is comprised which forms the support for the loaded bobbins (14) with the relevant capsules (13). On the front a shaped stirrup (24) is provided which forms the bearing of said bobbin-capsule assemblies and which performs the function of a guide for the engagement of the mobile pliers (1); in its turn, the front part (25) of said pliers (1) is provided with guide elements (26) which shift with the configuration of said capsules. This has the purpose of ensuring always and certainly the coupling of the parts, their self-alignment and their sure connection during the catchings of the mobile arm (2) with spout (17).
The back part of the loading cartridge (21) comprises a spring-pusher (27) which keeps the bobbin-capsule assemblies always pushed towards the outlet.
Two side levers (28) with pawls (29) and elastic hooking side means (30) permits loading cartridge (21) to maintain the correct position during normal operation, and to unhook the same in a quick and safe manner for its replacement with another similar one, once it is unloaded.
In the described operating cycle a possible further stage may be added related to the control of the loading cartridge (21). In this case, pliers (1), before being brought to the resting position, after the replacement of an empty bobbin, is aligned again with said loading cartridge (21), and, with the forward motion of runner (7), it is controlled through a microsensor inserted in the device, if there still are capsules (13) with the relevant loaded bobbins (14) in its inside.
In case of absence, a sound or light or mixed signal is emitted which informs the operator about the need of a replacement operation of the empty cartridge with a loaded one, before the machine exhausts the last bobbin.
While this invention has been illustrated and described according to an embodiment proposed by way of example, it will be apparent to those skilled in the art that various modifications may be made in the mechanical details, the operating sequence, the orientation of the parts, the controls and the activating means thereof, without falling outside its field and scope. | With planned sequential movements a mechanical pliers (1) is coaxially aligned with seat (5) of capsule (13) wherein the empty bobbin (14) of the lower thread of a sewing machine engages, caused to move forward until it engages with said capsule and to move backward, taking the same out from its seat, aligned with a collection basket (19) wherein capsule (13) and the empty bobbin (14) are unloaded, shifted and aligned coaxially with a loading cartridge (21) of capsules (13) containing bobbins (14) loaded with wound thread, caused to move forward until it engages and hooks on to the first of said capsules with loaded bobbins, then to move backward with said capsule with the bobbin, realigned coaxially with seat (15) of the sewing machine, caused to move forward up to the engagement of the capsule with the loaded bobbin in seat (15), and lastly is caused to move backward and placed in resting position, on prior release of the capsule with the loaded bobbin in the aforementioned seat. The operation is performed with full automation of the replacement stages of the lower thread bobbins with loaded bobbins. | 3 |
BACKGROUND OF THE INVENTION
The invention relates to accessories to firearms, particularly such accessories as will assist a marksman in the loading in an ammunition loading bearing magazine with ammunition.
Many small arms, including both rifles and handguns, are in the category known as magazine or clip fed. In these firearms, ammunition is placed into an elongated, generally rectangular cross-sectioned container known as a magazine or clip which is then fitted into a portion of the firearm approximate to the firing chamber. The magazine or clip is closed on five sides and open on a rectangular shaped end. Such magazines or clips are spring loaded and further adapted with retaining members over the open end. Ammunition is then slipped into the open end of the magazine, piece by piece, and each piece slips past the retaining member to be held until used. As the magazine is being loaded each succeeding round of ammunition compresses the spring further and becomes harder to insert.
When the magazine is fully loaded it is fitted into a position adjacent to or fitted against the firing chamber of the weapon. Normally a bolt is used to extract a round and force it into the firing chamber. As each round is fired the bolt is forced back, picks up the next round, and forces the next round into the firing chamber. The force of the spring pushes each round up into a position of the magazine where the bolt can push it into the firing chamber.
It can readily be seen that the task of loading successive rounds of ammunition into a magazine is one which requires some care and manual dexterity. This is particularly true on cold days when a person's fingers are numb, or are enclosed in a glove or mitten, in a situation (such as military combat) when speed in reloading may be of the essence.
A number of devices exists which are adapted to assist the marksman in accomplishing this task. In particular U.S. Pat. No. 4,446,645 issued to Kelsey on May 8, 1984, U S. Pat. No. 4,413,437 issued to Anderson on Nov. 8, 1983, and U.S. Pat. No. 4,452,002 issued to Musgrave, on June 5, 1984, describe various forms of magazines which are adapted for easy loading. Each of these inventions is designed to provide a more satisfactory form of ammunition magazine or clip but do not realistically solve the problems encountered by fitting a round of ammunition into the magazine or cartridge opening.
U.S. Pat. No. 4,464,855, issued to Musgrave on Aug. 14, 1984, teaches a device somewhat useful in solving the above described problem. It teaches a slidably attached apparatus which is adapted with a pulling handle and a protrusion which is adapted to push a round of ammunition down into the magazine for insertion of the next round. After each successive round of ammunition is loaded into the magazine the apparatus must be removed from the magazine and reinserted for the next round. While it does facilitate in solving this problem, the requirement of removal and reinsertion makes its use somewhat tedious.
U.S. Pat. No. 4,689,909, issued to Howard on Sept. 1, 1987, teaches a device which can he fitted over an ammunition magazine. It is adapted with a spring loaded plunger which, when the device is fitted over the magazine and somehow held in place, is used to push the uppermost round down into the magazine to facilitate sliding in the next round. Then the plunger, which is spring loaded, is depressed and the cartridge is fitted all the way into the back of the magazine. Howard is also somewhat helpful, but difficulties may be encountered in holding the device in place against the magazine. It should also be noted that both Howard and Musgrave are, because of their structure, primarily useful only in magazines over a narrow range of sizes.
What is missing in the prior art is such a device which can be used on a variety of magazine sizes and types, which permits the plunging task to be repeatedly and continuously performed with one hand, and which comprises no moving parts.
SUMMARY OF THE INVENTION
The present invention is adapted to satisfy the needs described above. It comprises an elongated hollow rectangular shaped casing which is open at one rectangular end and substantially open, except for a plunging mechanism, at the other rectangular end. It further comprises one or more serrated surfaces to assist the marksman in gripping the device for loading the magazine or clip.
It is an object of the invention to provide an apparatus useful in assisting a marksman in quickly and easily loading an ammunition magazine or clip.
It is another object of the invention to provide such a magazine or clip loading apparatus which is useful with a variety of sizes and types of ammunition magazines or clips.
It is a further object of the invention to provide such an magazine or clip loading apparatus which may be easily used in very cold weather when a marksman's fingers are adversely affected by the effects of chill or when the marksman is required to wear gloves or mittens
Other features and advantages of the present invention will be apparent from the following description in which the preferred embodiments have been set forth in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an oblique view of the apparatus permitting the display of each major component.
FIG. 2 is a bottom view of the apparatus.
FIG. 3 is an oblique view of the apparatus at the beginning of use.
FIG. 4 is an oblique view of the apparatus during use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In describing the preferred embodiment of the invention reference will be made to the figures briefly described above. The apparatus will first be described with respect to its structure and then the use of the preferred embodiment will be detailed.
Making reference first to FIG. 1 the general structure of the device will be described. The preferred embodiment of the invention generally comprises an elongated rectangular structure generally (10) which is substantially hollowed out, said hollowed out area (11) also generally being an elongated and of rectangular cross section (12). The outside surface (14) of the elongated rectangular member (11) is adapted with at least one serrated area (15). The serrated area appears on an end (16) of one of the two narrow sides (17). Extending from the inner surface (18) of the opposite narrow side (17) at the opposite end (19) of the apparatus (10) generally extends a short rigid protrusion (20), which could have a concave lower surface (31).
Reference will now be made to FIG. 2 which is a view of the lower end (16) of the apparatus (10). From the view of the apparatus (10) afforded by FIG. 2, it can been seen that said apparatus (10) includes a rectangular opening (21) at its bottom end (16). The dimensions (22, 23) of this opening should be sufficient to permit the insertion of an ammunition magazine or clip (not depicted in FIG. 2). Furthermore, the hollowed area (12) should be of adequate dimensions throughout its length (24) to permit such an ammunition magazine or casing to slide freely throughout the apparatus (10) until making contact with the short and rigid protrusion (20).
At this point it is appropriate to make some comments regarding these dimensions (22, 23).
Ammunition magazines and clips for such small arms come in a variety of sizes in order to accommodate a variety of weapons and ammunition types. The apparatus as taught in the present embodiment can be made of any dimensions desired. There may be certain dimensions which are suitable for operation with a variety of different ammunition magazines and clips. There may also be situations however when it is only appropriate to manufacture such an apparatus for application to a specific ammunition or clip. In such cases these dimensions (22, 23) should be made to allow only a small gap between the interior surface (18) of the apparatus (10) and the specific ammunition magazine or clip in use.
Reference will now be made to FIG. 3 which is a depiction of the apparatus (10) in place over an ammunition magazine or clip (25) into which one or more rounds of ammunition (26) have been loaded. As shown, a magazine or clip (25) has been inserted through the apparatus (10) until a round of ammunition (26) makes contact with the rigid protrusion (20). It can been seen that such a magazine or clip (25) has a generally open end (27) to permit the insertion and removal of a round of ammunition (26). Said open end (27) is further adapted with a retaining member 28) which is positioned so as to hold a round of ammunition (26) in place for extraction from the magazine or clip (25) and insertion into the firing chamber of the weapon (not depicted). At the lower end (29) of the magazine (25) (within the magazine and not depicted here) exists a spring which serves to push each successive round of ammunition (26) to the retaining member (28) for such extraction.
In order to load a round of ammunition (26) into the open end (27) of the magazine (25) it is necessary to push the uppermost round of ammunition (26) down into the magazine (25) and slide another round of ammunition (26) in between the retaining member (28) and the present uppermost round of ammunition (26). Assistance with this task is the purpose of the present invention.
From the position depicted in FIG. 4, it can be seen that by putting pressure with one's finger or thumb against the serrated area (15) of the outer surface of the apparatus (10) the rigid protrusion (20) will force the uppermost round of ammunition along with the rigid protrusion (20) down into the interior of the magazine (generally 30). A new round of ammunition (26) can than be easily slid into the space between the retaining member (28) of the magazine (25) and the present uppermost round of ammunition (26) in the magazine (25). This operation is depicted in FIG. 4.
Without such an apparatus (10), a person would normally be required to use a finger or thumb to push to most uppermost round (26) out of the way and hold such round (26) in place while the next round is slipped into position. Not only does such a task require the full use of two hands but also requires substantial dexterity and strength of the hand responsible for pushing and holding the present uppermost round (26) into position. This task is particularly hard when the weather is cold as fingers either experience considerable discomfort or the person loading the ammunition is wearing gloves or mittens, making this task difficult from the standpoint from required dexterity.
After each successive round of ammunition (26) is loaded into the magazine (25) this process can be repeated as many times as necessary to fill the magazine (25) to capacity with rounds of ammunition (26). As each successive round of ammunition (26) is loaded into the magazine (25) it should also be noted that this task becomes more and more difficult as the tension on the spring at the spring (not depicted) at the lower end of the magazine (29) becomes more tense and difficult to operate.
It should be noted that the invention can be made to fit a particular sized ammunition magazine or clip. It can also be made to fit all the various sized ammunition magazines or clips of a given claibre. It can further be made to fit (or work in conjunction with) a number of different sized ammunition magazines or clips within a reasonable range of sizes.
Certain other modifications of the invention are clearly possible which do not depart from the true spirit of the invention. For instance, the serrated area (15) is described as being on the side opposite from the rigid protrusion (20). Such serrated surface however could easily be placed on any exterior surface of the apparatus, including the larger sides adjacent to the broad sides of the magazine. Such a serrated surface would be useful at any point along the exterior surface in keeping with the needs of an individual marksman. Additionally, a shell apparatus could be adapted with an overall hollowed out area large enough to accommodate virtually any sized ammunition magazine or clip, but then equipped with one or more interchangeable and removable rigid protrusions to enable such a shell to be used with a variety of ammunition calibres and lengths.
Modification and variation can be made to the disclosed embodiments without departing from the subject and spirit of the invention as defined in the following claims. Such modifications and variations, as included within the scope of these claims, are meant to be considered part of the invention as described. | An apparatus for assisting a marksman in loading ammunition into a magazine or clip generally comprising a rectangular sleeve which is adapted with an interior plunging member and an exterior serrated gripping surface. | 5 |
FIELD OF THE INVENTION
This invention relates generally to dry cleaning apparatus and methods and particularly to those directed toward reduced environmental impact from dry cleaning operations.
BACKGROUND OF THE INVENTION
Dry cleaning establishments have become extremely commonplace throughout most of the industrialized nations of the world and have, for many years, provided valuable services in cleaning, sanitizing and restoring the usefulness of many fabrics and clothing garments which are not suitable for laundering operations. While the specific structures used in such dry cleaning operations vary somewhat with design, generally all utilize a closed drum having a rotatable tumbling basket disposed therein for receiving a quantity of clothing articles or the like for dry cleaning. The drum is equipped with an access door which is closed and preferably sealed during cleaning operations. The basic cleaning cycle involves the introduction of cleaning solvent into the drum and basket which is circulated through various filters as the tumbling basket is agitated or rotated to tumble the clothing articles through the solvent. At some point, usually under the control of a master timer, the solvent is extracted in a cycle which culminates in a high speed spin operation. Thereafter, a drying cycle is carried forward in which heated air is circulated through the basket and clothing articles. Often, the heated air used in drying is repeatedly heated prior to passing through the clothing articles and cooled thereafter to condense solvent out of the air and then reheated prior to the next circulation through the drying clothing articles. Once the drying cycle is complete, a reduction or cool down cycle is carried forward afterwhich the dry cleaning operation is complete.
When originally employed, such dry cleaning operations were relatively free of environmental concerns and regulations. Thus, in many early dry cleaning machines, the circulated air was simply vented to the atmosphere to carry away the solvent during the drying operation. However, recent environmental laws and regulations have imposed very strict constraints upon dry cleaning operations. In general, these regulations and laws have mandated the use of closed systems which do not vent solvent into the atmosphere generally. In addition, the environmental laws and regulations have essentially made necessary more efficient solvent recovery throughout the entire dry cleaning operation. The objective in addition to concerns over directly vented air into the atmosphere has also focused upon minimizing the solvent vapor vented between operations during unloading and loading as well as minimizing the amount of solvent residual remaining in clothes articles at the completion of the dry cleaning cycle. Many of the regulations and laws recently enacted have the stated purpose of reducing the solvent contaminants in the environment to avoid damage to the health and well being of laborers operating such machines. These regulations have an additionally stringent aspect to them in that the dry cleaning establishment environment often includes multiple dry cleaning machines as well as substantial quantities of recently cycled clothing articles awaiting pickup and removal. Thus, measurements directed to the total solvent content within the air at the cleaning facility essentially monitor the cumulative effect of many solvent sources.
While present available dry cleaning systems if properly operated may, in most instances, meet the present environmental and workplace safety regulations, they do so only if properly maintained and operated and optimally constructed. In view of the clear trend of environmental laws and regulations as well as workplace safety laws toward evermore strict and demanding requirements, it appears to be clear that present day dry cleaning systems will not be capable of meeting such stricter laws and regulations. Thus, there remains a continuing need in the art for evermore environmentally acceptable and safe to operate dry cleaning systems.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide an improved dry cleaning system and method. It is a more particular object of the present invention to provide an improved dry cleaning system and method which more efficiently and thoroughly recover the cleaning solvent from the system's air and clothing articles being cleaned.
In accordance with the present invention, there is provided a dry cleaning system for use in dry cleaning cloth articles, the dry cleaning system comprises: a cloth article drum having a movable basket therein; solvent circulation means for circulating a solvent through the drum; air circulation means for circulating air through the drum; and steam injection means for intermittently injecting steam into the drum at predetermined times when the air circulation means is operating.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify like elements and in which:
FIG. 1 sets forth a block diagram of a dry cleaning system constructed in accordance with the present invention; and
FIG. 2 sets forth a flow diagram of the present invention dry cleaning system and method of operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 sets forth a block diagram of a dry cleaning system constructed in accordance with the present invention and generally referenced by numeral 10. Dry cleaning system 10 includes a large hollow drum 11 within which a mesh or foraminous basket 12 is rotatably supported by conventional support mean (not shown). A basket motor 25 comprising a conventional electric motor is operatively coupled to basket 12 such that basket 12 is rotated when motor 25 is energized. Drum 11 further defines an inlet portion 15 and an exit portion 14 forming respective parts of the air circulating system. A return duct 16 couples exit portion 14 to a conventional button trap 17. Button trap 17 is intended to provide a convenient drop basket within which buttons and other heavy articles inadvertently separated from the clothing within basket 12 are retained due to their substantial weight. Button trap 17 is coupled by an air duct 18 to a motor driven fan 19. Motor driven fan 19 is constructed in accordance with conventional fabrication techniques and provides 10 an air flow from button trap 17 into a solvent recovery station 20. In accordance with conventional fabrication techniques, solvent recovery station 20 includes a plurality of operative elements within the stream of fan driven circulating air which include a condensing coil 21, a heat pump coil 22 and a steam coil 23. A duct 24 couples solvent recovery station 20 to inlet 15 of drum 11 completing the air circulation path for dry cleaning system 10.
In addition to the air circulating system shown in FIG. 1, dry cleaning system 10 also includes a solvent circulating system. Thus, a solvent reservoir or base tank array 40 is coupled to a distilling unit 42 by a circulating pipe 41. The output of still 42 is coupled to a solvent filter 44 by a pipe 43. A solvent pump 46 is coupled to filter 44 by an input pipe 45 and is coupled to the interior of drum 11 by a pipe 47. A return pipe 48 is also coupled to drum 11 and to a water separating unit 49. The latter is further coupled to solvent reservoir 40.
Thus, a solvent circulating system is provided by solvent pump 46, filter 44, distilling unit 42 and water separator 49 together with the interconnecting coupling pipes which draws cleaning solvent from reservoir 40 processes it and circulates it through drum 11 to perform the above-described cleaning action. It will be apparent to those skilled in the art that the circulating systems shown in FIG. 1 are generalized and substantial variation of the relative locations within the circulating streams of each system may be changed without departing from the spirit and scope of the present invention and thus the systems shown are merely exemplary and should not be construed as limiting in any fashion.
In accordance with an important aspect of the present invention, dry cleaning system 10 further includes a steam injection system having a source of heated steam 60 constructed in accordance with conventional fabrication techniques for producing high pressure heated steam. Steam source 60 includes an output 65 which is coupled to a steam injection valve 63 by the series combination of a manual shut-off valve 61 and a filter 62. Injection valve 63 is further coupled to a steam injection nozzle 64 which extends into the interior of drum 11.
A cycle timer 50 includes conventional cycle timing apparatus and is coupled to motor driven fan 19, solvent pump 46, basket motor 25 and injection valve 63. Thus, timer 50 is, in its preferred form, a programmable timer which permits controlled operation of the various components within dry cleaning system 10 to provide the method of operation set forth below in FIG. 2 in greater detail. However, suffice it to note here that timer 50 provides the basic control for the operation of dry cleaning system 10 through the desired cycle.
In operation, a quantity of clothes articles 13 are introduced into drum basket 11 by the operator. Thereafter, timer 50 is activated to commence a dry cleaning cycle. Initially, timer 50 energizes basket motor 25 to tumble or otherwise agitate basket 12 while simultaneously energizing solvent pump 46. As clothing articles 13 tumble or are otherwise agitated within basket 12 of drum 11, solvent pump 46 circulates cleaning solvent from reservoir 40 to distilling unit 42 and thereafter through filter 40 to solvent pump 46. Still 42 provides a distilling operation upon the solvent circulated therethrough which in accordance with conventional distillation processes purifies the solvent and removes a variety of contaminants and undesired water or the like. Filter 44 provides a particulate matter separation to further purify the circulating solvent prior to its introduction into drum 11 and its circulation through clothing articles 13. The circulating cleaning solvent returns to reservoir 40 through a return pipe 48 from drum 11 and is passed through a water separator 49 prior to return to solvent reservoir 40. Water separator 49 operates as the name indicates to remove and separate any water within the circulating fluid prior to its return to reservoir 40.
This solvent fluid circulation and tumbling action continues for a predetermined cycle time set within programmable timer 50. Once timer 50 has timed out on this portion of the cleaning cycle, timer 50 ceases the operation of solvent pump 46 and activates basket motor 25 in accordance with the high speed spin extraction portion of the cycle. During the spin extraction portion of the cleaning cycle, basket 12 is rotated at a greatly increased speed forcing clothing articles 13 outwardly against the interior surfaces of basket 12. As the spin extraction continues, the centrifugal force produced operates to draw a substantial portion of the solvent remaining within the clothing articles. This additionally extracted solvent is returned to reservoir 40 through water separator 49. Once the spin extraction cycle is complete, timer 50 ceases the spin cycle and initiates the cycle portion dedicated to drying clothing articles 13. During the drying portion of the cycle, timer 50 energizes motor driven fan 19 while simultaneously returning the operation of basket motor 25 to its normal tumbling activity. Thus, under the urging of fan 19, air is circulated through solvent recovery station 20, drum 11, button trap 17 and is returned to motor driven fan 19. To enhance the operation of the drying cycle, the air passing through solvent recovery station 20 is initially cooled by condensing coil 21 which acts to condense out solvent vapors picked up by the air circulating through drum 11 and carried by the air circulation provided by fan 19. This condensing action cools the passing air and recovers an additional portion of the solvent which is returned to solvent reservoir 40 by coupling means not shown. The cooled circulating air is further moved under the urging of fan 19 through a heat 10 pump coil 22 and steam coil 23. The function of coils 22 and 23 within recovery station 20 is to provide a reheating of the circulating air passing through condensing coil 21. This heated air is more efficient at vaporizing and carrying away residual solvent material still present within clothes 13. This heated air is introduced into drum 11 through inlet 15 and is circulated therethrough as clothes 13 continue to tumble. The heated air having picked up additional solvent from clothes 13 is returned through return duct 16 and button trap 17 to motor driven fan 19 completing the circulation.
In accordance with an important aspect of the present invention, the heated air passing through drum 11 during the drying cycle is subjected to an injection of high temperature steam at the optimum cycle time in accordance with the programming of timer 50. This steam injection is provided by the operation of timer 50 in opening injection valve 63 which permits the flow of high temperature steam outwardly from source 60 through outlet 65, valve 61 and filter 62. The heated steam is injected within drum 11 through one or more nozzles represented by injection nozzle 64 to produce an injected steam flow 64. The steam injection bombards the internal solvent saturated air flow within drum 11 with a stream of water and steam particles to induce a momentary humidity increase within drum 11 which shocks the air therein and improves the saturation environment within drum 11. It has been found that this steam injection provides a substantial improvement in the efficiency of solvent recovery during the drying cycle. It has been further found that the cycle efficiency may be further enhanced by periodic repeated injections of high temperature steam during the drying cycle. The combined steam, water vapor and recovered solvent is carried from drum 11 through exit port 14 through button trap 17 and is driven by fan 19 through condensing coil 21. Once again, the cooling action of coil 21 causes the water vapor and steam as well as the captivated solvent within the circulated air stream to be largely removed as condensation of both solvent and water vapor occurs. This process continues until timer 50 terminates the drying cycle and initiates the portion of the dry cleaning cycle generally referred to as reduction. During reduction, the heating actions of coils 22 and 23 are ceased and circulating air continues as does the tumbling or agitating action upon clothes 13.
In accordance with a further important advantage of the present invention, it has been advantageous to provide one or more steam injections during the reduction or cool down portion of the cycle. Once again, the operation of the steam injection is controlled by timer 50 in accordance with the desired user program. The steam injection provides the above-described bombardment of solvent saturated air flow within drum 11 and once again carries off still further quantities of solvent vapor thereby further increasing the efficiency of solvent recovery of dry cleaning system 10.
FIG. 2 sets forth a flow diagram of the operation of dry cleaning system 10 in accordance with the present invention method. The dry cleaning cycle is initiated at a step 70 by depositing a quantity of to-be-cleaned clothing articles within the drum basket. Thereafter, the system moves to a step 71 in which solvent is circulated to fill the cleaning drum to the desired level. Next, the system moves to simultaneous steps 72 and 73 in which the cleaning basket is agitated or rotated and in which the solvent is circulated through the cleaning basket and clothing articles therein. Following the solvent circulation, the solvent is drained from the cleaning drum at a step 74. It may be desirable in system operation to maintain the agitation or tumbling operation of step 73 during the solvent draining process of step 74.
Once the solvent has been drained at step 74, the system moves to a spin extraction step 75 in which the cleaning basket is rotated at high speed to provide further solvent extraction. Thereafter, the system moves concurrently to step 76 and step 77. In step 76, heated air is circulated through the drum and drum motion is returned to agitation or tumbling action. At step 77, the circulating air is cooled to provide the above-described condensation of solvent and water vapor thereby enhancing drying action. In addition, the system also implements a predetermined time delay at step 78 afterwhich the system moves to a step 79 in which heated steam is injected into the drum in the manner described above. Thus, steps 76 and 77 continue while the steam injection step 79 is delayed with respect to steps 76 and steps 77 and is periodically operable during the continuing action of steps 76 and 77. As heated air is circulated together with drum agitation and solvent condensation is carried forward and as periodic steam injection cycles take place, the system determines at step 80 whether the drying cycle has timed out. So long as the drying cycle has not been found at step 80 to have timed out, the system continues to operate steps 76, 77, 78 and 79 until a determination is made that drying cycle time has expired. Thereafter, the system moves to a step 81 at which the reduction portion of the dry cleaning cycle is initiated. During the reduction portion of the dry cleaning cycle, the system simultaneously maintains the circulation of cool air and basket tumbling or agitation at step 82, recovers the solvent and water from the circulating cool air at step 84, and provides one or more timed steam injections at step 83. Steps 82 through 84 are maintained simultaneously until the time interval for the reduction portion of the drying cycle expires afterwhich the system moves to a step 85 ending the dry cleaning cycle.
Thus, what has been shown is an increased efficiency dry cleaning system and method which utilizes periodic steam injections during the drying and reduction portions of the dry cleaning cycle to increase the effectiveness of solvent recovery beyond that obtained by prior art systems and methods. It has been found that utilizing the present invention steam injection system significantly reduces solvent emissions during the dry cleaning process. It has been found that solvent vapor levels in the proximity to the dry cleaning equipment both during and after operation with door opening and loading and unloading activities taking place is significantly reduced. It has further been found that garments cleaned using the present invention system and method retain reduced amounts of solvent and thus provide safer work conditions for operating personnel and safer end products for the end user/consumer. In addition, the increased efficiency and greater solvent recovery has been found to decrease solvent consumption for the owner operator which provides significant savings of operating costs attributed to solvent use. Finally, it has been further found that the improved efficiency of the present invention system also reduces the drying cycle process time thereby increasing the through put capacity of the present invention system and method resulting in further savings to the owner operator of the dry cleaning establishment.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A dry cleaning system and method includes having a rotatable basket therein for receiving to-be-cleaned clothing articles. A fluid circulating system provides for the circulation filtering and cleaning of dry cleaning solvent through the cleaning basket and clothes therein. An air circulating system includes a motor driven fan together with a solvent recovery station utilized to pass heated air through the basket and clothing therein to extract the solvent therefrom. A steam injection system is periodically operated during the drying and reduction portions of the dry cleaning cycle to improve the efficiency of solvent recovery and increase the effectiveness of the dry cleaning system. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
Reference is made to commonly-assigned copending U.S. patent application Ser. No. 14/097,324 filed Dec. 5, 2013, entitled METHOD OF PRINTING INFORMATION ON A SUBSTRATE, by Pawlik et al., the disclosure of which is incorporated herein.
FIELD OF THE INVENTION
The invention relates in general to printing information on a substrate and in particular to migration of a portion of the printed information to a second surface of the substrate.
BACKGROUND OF THE INVENTION
Information printed with bleed through or penetrating ink is a document security feature that is common in checks and other monetary instruments. The bleed through effect makes alteration of the document much more difficult. Verification of the security feature is possible without additional tools.
Most commonly, bleed through inks consist of a black colorant that stays on the print side of the media and a magenta colorant that penetrates the media and creates a visible stain on the non-print side of the media. For printing of fixed data, inks can be printed specifically by dry or wet offset by screen-, flexo- and gravure-printing or by letterpress.
For variable data such as check numbers, this security feature is most commonly applied via impact printing. The inks used in impact printing are often oil based so that the drying time is extended, thus allowing the dye to penetrate as shown in European Patent No. 0 835 292 B1. Characters or linear barcodes are imprinted using coding wheels such as the impact numbering machines offered by the company Atlantic Zeiser.
A disadvantage of the impact printing approach is that there is limited flexibility to design the printed information. It is limited to a fixed number of digits of numbers and some one-dimensional barcodes of fixed length. Two-dimensional barcodes and graphics cannot be printed in this manner. Therefore, it is desirable to have a digital, non-impact way of delivering this security feature such as continuous inkjet printing. It can be difficult, however, to formulate a continuous inkjet ink that has the necessary penetrating and drying properties while maintaining good drop generation and recirculation properties and image quality. It is particularly difficult to generate a two component ink wherein one colorant stays on the print side of the media while the other penetrates to the non-print side.
An inkjet printing ink that does not need to have unusual penetrating properties, but that still forms an image on the non-print side of the media would therefore be desirable.
SUMMARY OF THE INVENTION
Briefly, according to one aspect of the present invention a system for printing information on a substrate includes a printer for printing the information on a first surface of the substrate; and a heater for heating the substrate causing at least a portion of the printed information to migrate to a second surface of the substrate.
The present invention is an integral printing ink that contains a black colorant and a magenta colorant. The black colorant may be, for example, carbon black and the magenta colorant is a sublimable pigment or dye. The document is printed with this combination. Subsequently, the printed document is exposed to a temperature above the sublimation temperature of the magenta colorant. In the gaseous state the magenta colorant will penetrate the porous substrate and after sufficient heating a mirror image of the printed information will be visible on the non-print side. Preferably, heating of the document will be performed using infrared dryers, such as manufactured by Adphos Innovative Technology GmbH and implemented on Prosper presses such as manufactured by Eastman Kodak Company.
The magenta and black components of the ink can also be printed in registration in separate passes. On some substrates the inks will form a mixed phase rather than a layered structure and the two pass printing will create the same result as one pass printing with a single ink that integrates both colorants. With a two pass approach, however, one has the opportunity to print different information with the two colorants. For example, one can print a text or number and then overprint this text with a solid area of black ink. The text or number will be invisible. After heating of the print media, the magenta ink component will become volatile and migrate such that the hidden information will become visible. This could serve as a security and authentication feature. Experiments with two pass printing have also shown that, in the absence of the black colorant, the magenta dye will not reach sublimation temperature in the IR dryer. Therefore this security ink relies on the two-step process of black colorant as IR absorber and heat generator and the magenta dye as the heat activated mobile component.
The invention and its objects and advantages will become more apparent in the detailed description of the preferred embodiment presented below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a printed substrate.
FIG. 2 is a schematic representation of a printed substrate under the influence of electromagnetic radiation.
FIG. 3 is the halftone image of the print side of a printed sheet of paper using black ink.
FIG. 4 is the halftone image of the non-print side of a printed sheet of paper using black ink.
FIG. 5 is the halftone image of the print side of a printed sheet of paper using black and magenta ink according to the invention.
FIG. 6 is the magenta extraction image of the non-print side of a printed sheet of paper using black and magenta ink according to the invention.
FIG. 7 is the halftone image of the print side of a printed sheet of paper using black and magenta ink in a two pass printing process according to the invention.
FIG. 8 is the magenta extraction image of the non-print side of a printed sheet of paper using black and magenta ink in a two pass printing process according to the invention.
FIGS. 9 a and 9 b are the magenta extraction image of the non-print side of a printed sheet of paper using alternating characters printed with black and magenta ink or magenta ink only, respectively.
FIG. 10 is the halftone image of the print side of a printed sheet of paper wherein magenta text and numbers were printed in a first pass.
FIG. 11 is the halftone image of the print side of a printed sheet of paper wherein magenta text and numbers and black overlapping rectangles were printed in two sequentially passes.
FIG. 12 is the magenta extraction image of the non-print side of a printed sheet of paper using where magenta text and numbers and black overlapping rectangles were printed sequentially in two passes.
FIG. 13 is a cross-sectional view of an embodiment of an inkjet printer as used in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be directed in particular to elements forming part of, or in cooperation more directly with the apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.
The present invention is a method of printing information on a first surface of a substrate using two ink components wherein the first ink component absorbs electromagnetic radiation converting it to heat and the second ink component is able to migrate to a second surface of the substrate. In preferred embodiments, the black colorant is carbon black and the magenta colorant is a sublimable pigment or dye although other colors and materials may be suitable. The document is printed with this combination either using the mixture of the two ink components in an integral printing ink, or applying the inks separately in a two pass printing step. Subsequently the printed document is exposed to a temperature above the sublimation temperature of the magenta colorant. In the gaseous state the magenta colorant will penetrate the porous substrate and after sufficient heating a mirror image of the printed information will be visible on the non-print side.
The printing ink can be delivered by conventional contact printing methods such as offset, gravure, flexography, letterpress. Preferably, a digital printing method like electrophotography or inkjet printing can be used because it allows for the printing of variable content. Drop-on-demand (DOD) liquid emission devices have been known as ink printing devices in ink jet printing systems for many years. Early devices were based on piezoelectric actuators such as are disclosed in U.S. Pat. Nos. 3,946,398 and 3,747,120. A currently popular form of ink jet printing, thermal ink jet (or “thermal bubble jet”), uses electrically resistive heaters to generate vapor bubbles which cause drop emission, as is discussed in U.S. Pat. No. 4,296,421. In another process, known as continuous inkjet (CIJ), a continuous stream of droplets is generated, a portion of which are deflected in an image-wise manner onto the surface of the image-recording element, while un-imaged droplets are caught and returned to an ink sump. Continuous inkjet printers are disclosed in U.S. Pat. Nos. 6,588,888; 6,554,410; 6,682,182, 6,793,328, 6,866,370, 6,575,566, and 6,517,197.
The inks used for inkjet printing are typically water-based and formulated to comprise a selection of water, dispersed pigment particles, dyes, humectants, dispersants, surfactants, biocides, polymers and organic solvents. Formulations for drop-on-demand (DOD) printing inks are disclosed in U.S. Patent Application No. 2013/0237661 which is incorporated herein in its entirety by reference. Likewise, formulations for CIJ inks are disclosed in U.S. Pat. No. 8,398,223 which is incorporated herein in its entirety by reference.
Examples of suitable sublimable dyes, including magenta, yellow, and cyan dyes, can include, but are not limited to, diarylmethane dyes; triarylmethane dyes; thiazole dyes, such as 5-arylisothiazole azo dyes; methine dyes such as merocyanine dyes, for example, aminopyrazolone merocyanine dyes; azomethine dyes such as indoaniline, acetophenoneazomethine, pyrazoloazomethine, imidazoleazomethine, imidazoazomethine, pyridoneazomethine, and tricyanopropene azomethine dyes; xanthene dyes; oxazine dyes; cyanomethylene dyes such as dicyanostyrene and tricyanostyrene dyes; thiazine dyes; azine dyes; acridine dyes; azo dyes such as benzeneazo, pyridoneazo, thiopheneazo, isothiazoleazo, pyrroleazo, pyrraleazo, imidazoleazo, thiadiazoleazo, triazoleazo, and disazo dyes; arylidene dyes such as alpha-cyano arylidene pyrazolone and aminopyrazolone arylidene dyes; spiropyran dyes; indolinospiropyran dyes; fluoran dyes; rhodaminelactam dyes; naphthoquinone dyes, such as 2-carbamoyl-4-[N-(p-substituted aminoaryl)imino]-1,4-naphthaquinone; anthraquinone dyes; and quinophthalone dyes. Specific examples of dyes usable herein can include:
C.I. (color index) Disperse Yellow 51, 3, 54, 79, 60, 23, 7, and 141; C.I. Disperse Blue 24, 56, 14, 301, 334, 165, 19, 72, 87, 287, 154, 26, and 354; C.I. Disperse Red 135, 146, 59, 1, 73, 60, and 167; C.I. Disperse Orange 149; C.I. Disperse Violet 4, 13, 26, 36, 56, and 31; C.I. Disperse Yellow 56, 14, 16, 29, 201 and 231; C.I. Solvent Blue 70, 35, 63, 36, 50, 49, 111, 105, 97, and 11; C.I. Solvent Red 135, 81, 18, 25, 19, 23, 24, 143, 146, and 182; C.I. Solvent Violet 13; C.I. Solvent Black 3; C.I. Solvent Yellow 93; and C.I. Solvent Green 3.
Further examples of sublimable or diffusible dyes that can be used include anthraquinone dyes, such as Sumikalon Violet RS® (product of Sumitomo Chemical Co., Ltd.), Dianix Fast Violet 3R-FS® (product of Mitsubishi Chemical Corporation.), and Kayalon Polyol Brilliant Blue N-BGM® and KST Black 146® (products of Nippon Kayaku Co., Ltd.); azo dyes such as Kayalon Polyol Brilliant Blue BM®, Kayalon Polyol Dark Blue 2BM®, and KST Black KR® (products of Nippon Kayaku Co., Ltd.), Sumickaron Diazo Black 5G® (product of Sumitomo Chemical Co., Ltd.), and Miktazol Black 5 GH® (product of Mitsui Toatsu Chemicals, Inc.); direct dyes such as Direct Dark Green B® (product of Mitsubishi Chemical Corporation) and Direct Brown M® and Direct Fast Black D® (products of Nippon Kayaku Co. Ltd.); acid dyes such as Kayanol Milling Cyanine 5R® (product of Nippon Kayaku Co. Ltd.); and basic dyes such as Sumicacryl Blue 6G® (product of Sumitomo Chemical Co., Ltd.), and Aizen Malachite Green® (product of Hodogaya Chemical Co., Ltd.).
Other suitable cyan dyes can include Kayaset Blue 714 (Solvent Blue 63, manufactured by Nippon Kayaku Co., Ltd.), Phorone Brilliant Blue S-R (Disperse Blue 354, manufactured by Sandoz K. K.), Waxoline AP-FW (Solvent Blue 36, manufactured by ICI), and cyan dyes of the structures
where R1 and R2 each independently represents an alkyl group, a cycloalkyl group, an aryl group, a heterocyclic group, or R1 and R2 together represent the necessary atoms to close a heterocyclic ring, or R1 and/or R2 together with R6 and/or R7 represent the necessary atoms to close a heterocyclic ring fused on the benzene ring; R3 and R4 each independently represents an alkyl group, or an alkoxy group; R5, R6, R7 and R8 each independently represents hydrogen, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, a carbonamido group, a sulfamido group, hydroxy, halogen, NHSO2R9, NHCOR9, OSO2R9, or OCOR9, or R5 and R6 together and/or R7 and R8 together represent the necessary atoms to close one or more heterocyclic ring fused on the benzene ring, or R6 and/or R7 together with R1 and/or R2 represent the necessary atoms to close a heterocyclic ring fused on the benzene ring; and R9 represents an alkyl group, a cycloalkyl group, an aryl group and a heterocyclic group.
Other suitable yellow dyes can include Phorone Brilliant Yellow S-6 GL (Disperse Yellow 231, manufactured by Sandoz K. K.) and Macrolex Yellow 6G (Disperse Yellow 201, manufactured by Bayer), and yellow dyes of the structures
Further examples of useful dyes can be found in U.S. Pat. Nos. 4,541,830; 4,698,651; 4,695,287; 4,701,439; 4,757,046; 4,743,582; 4,769,360; 4,753,922; 5,026,677; 5,101,035; 5,142,089; 5,804,531; and 6,265,345; and U.S. Publication No. 2003/0181331. If the dyes are insoluble in the ink, they can be milled into pigments of a suitable size distribution and incorporated into the ink as a dispersion.
In order to show the effect of colorant bleed through in a black and white figure, the following image transformation was used for most figures depicting the backside of printed and treated samples. The surface of the printed media was scanned using the scanning function of a Kodak ESP 5200 All In One printer. Scanning was performed in color at 300 dpi. The images were saved as jpeg files. Subsequently, the image files were loaded into Corel Photo Paint 10 (Corel Corporation, 2000) and the following image transformations were executed: The color image was split into the Cyan, Magenta, Yellow and Black components. The Magenta component, represented by a 8-bit grayscale image, was then converted into a binary (black/white) image using a threshold of 225 within the allowed range of 0-255. Images processed this way will be referred to as “magenta extraction images.” Images from the front side of media and the image shown in FIG. 4 were similarly scanned and were converted from the red, green, blue (RGB) color representation to binary images using Corel Photo Paint 10 by applying the standard halftone conversion (45 degree angle, 150 lines per inch). These images will be referred to as “halftone images.”
Referring now to FIG. 1 which shows a schematic representation of a printed substrate 100 . The ink applied to the print side of the substrate 102 consists of a first component 106 that is non-migrating under the influence of heat and a second component 108 that migrates under the influence of heat. The substrate is a porous medium such as paper. Therefore, the ink partially soaks into the substrate.
FIG. 2 shows the printed substrate 100 under the influence of electromagnetic radiation containing infrared radiation 110 . In this example, the first component of the ink 106 is able to absorb the electromagnetic radiation and convert it to heat. This leads to a local increase in temperature. The temperature increase is large enough such that the second component of the ink 108 is able to migrate through the porous structure of the substrate, and a fraction of the second component of the ink 108 appears on the non-print side of the substrate 104 creating a visible effect. If the electromagnetic radiation 110 is switched off and the temperature of the substrate returns to its ambient value, the second component of the ink 108 will no longer migrate and will be locked into position thus making the effect permanent unless the substrate is heated again.
Although paper was used as an example, this process can be used with other types of substrates, for example plastics, as long as the second component of the ink is chosen such that it has the ability to migrate through the substrate under the influence of heat.
Referring now to FIG. 3 which shows a halftone image of the print side of a letter size sheet of Glatfelter multi-purpose office paper, Material No. 22761, that was printed using a DOD inkjet printer with an ink that contained carbon back as a black colorant. This printed sheet was subjected to a radiative heating procedure by moving it on a conveyor beneath a stationary Adphos NIR40 infrared dryer (adphos Innovative Technologies GmbH). The direction of movement is indicated by the arrow. A 1.3 speed setting was used for the conveyor which represents a speed of 18.9 feet/minute. The infrared dryer only heats part of the sheet in an area that is indicated by the dashed box 120 .
FIG. 4 shows a halftone image of the non-print side of the paper in FIG. 3 . It is evident that none of the image content from the print side of the paper appears on the non-print side. In particular there is not any more print density in the inside the heated area 120 compared to outside the heated area. This shows that the infrared heating procedure does not lead to migration of the carbon black component of the ink.
FIG. 5 shows a halftone image of the print side of a letter size sheet of Glatfelter multi-purpose office paper, Material No. 22761, that was printed using a DOD inkjet printer with an ink that contained both a black and magenta colorant. The black colorant was carbon black, the magenta colorant was Disperse Red #60 which is a colorant that is able to migrate under the influence of heat. This printed sheet was subjected to a radiative heating procedure by moving it on a conveyor beneath the stationary Adphos NIR40 infrared dryer. A 1.3 speed setting was used for the conveyor which represents a speed of 18.9 feet/minute. The infrared dryer only heats part of the sheet in an area that is indicated by the dashed box 120 .
FIG. 6 shows the magenta extraction image of the non-print side of the paper in FIG. 5 . It is evident that a significant fraction of the image content from the print side of the paper appears in mirror image on the non-print side in the area 120 that is subject to the infrared heating process whereas outside of this area, no image appears. This shows that the infrared heating leads to migration of the magenta component of the ink.
FIG. 7 shows a halftone image of the print side of a letter size sheet of Glatfelter multi-purpose office paper, Material No. 22761, that was printed in registration in two passes using a DOD inkjet printer. The first pass was printed with an ink that contained and magenta colorant. The magenta colorant was Disperse Red #60 which is a colorant that is able to migrate under the influence of heat. In the second pass in ink that contained only carbon black as a colorant was used for printing. This printed sheet was subjected to a radiative heating procedure by moving it on a conveyor beneath the stationary Adphos NIR40 infrared dryer. A 1.3 speed setting was used for the conveyor which represents a speed of 18.9 feet/minute. The infrared dryer only heats part of the sheet in an area that is indicated by the dashed box 120 .
FIG. 8 shows the magenta extraction image of the non-print side of the paper in FIG. 7 . It is evident that the image content from the print side of the paper appears in mirror image on the non-print side in the area 120 that is subject to the infrared heating process whereas outside of this area, no image appears. This shows that the infrared heating leads to migration of the magenta component of the ink. The result of this two pass printing process is therefore similar to the case shown in FIG. 6 wherein a one pass printing process of a combined black and magenta ink was used. Printing a porous substrate such as the office paper in this example with two different inks will likely lead to a mixture of the two colorants on the printed substrate. In fact, reversing the order of printing had no effect on the non-print side image after the heating step. However, for other inks and substrates it may be conceivable that the sequence of printing could lead to different efficacy of migration, in particular if a multilayer structure is created on the print side of the substrate consisting of the individual inks One can then chose the sequence of printing that creates the optimal effect upon heat treatment.
FIG. 9 a shows a halftone image of the print side of a sheet of Glatfelter multi-purpose office paper, Material No. 22761 that was printed with a DOD inkjet printer in alternating fashion using two different inks. The first ink contained both black and magenta colorant according to the invention. Symbols printed with this ink are indicated by the reference number 140 and appear darker in the halftone image. The other symbols were printed with an ink that contained the magenta colorant only. These symbols, which appear lighter in the halftone image, are indicated by the reference number 142 . Two strings of numbers were printed in similar fashion. Since the assignment to the two inks is evident from the darkness of the characters in FIG. 9 a , only the first two numbers are explicitly assigned to 140 and 142 .
FIG. 9 b shows the magenta extraction image of the non-print side of the printed sheet of FIG. 9 a after heat treatment with the IR drying equipment at a nominal speed setting of 1.3. For better comparison of front side and back side images, FIG. 9 b was also flipped horizontally thus reversing the effect of the mirror image. It is evident from FIG. 9 b that only the characters that were printed with the combination of black and magenta colorant show on the back side of the paper after the heating process. This underscores that the black component of the ink is necessary to generate enough heat through absorption of the IR radiation to make the magenta colorant migrate through the paper.
FIG. 10 shows a halftone image of the print side of a sheet of Glatfelter multi-purpose office paper, Material No. 22761 that was printed with a DOD inkjet printer using magenta ink. Text and numbers were printed as a mirror image using ink with the magenta colorant Disperse Red #60 which is a colorant that is able to migrate under the influence of heat.
FIG. 11 shows a halftone image of the printed sheet of FIG. 10 that was overprinted in registration using a DOD inkjet printer with ink containing carbon black as a black colorant. Black rectangles were printed such that they completely overlap the text and numbers that were printed previously using magenta ink (compare FIG. 10 ). In the resulting halftone image, the printed text and numbers are obscured by the black rectangles, and therefore text and numbers are illegible.
FIG. 12 shows the magenta extraction image of the non-print side of the printed sheet of FIG. 11 after heat treatment with the IR drying equipment at a nominal speed setting of 1.5 corresponding to a conveyor speed of 22.8 feet/minute. It is evident in the figure that text and numbers that were printed using the magenta ink are now visible on the back side of the paper, but only inside the area 120 that experienced the heat from the IR dryer. This effect would be useful as a way of embedding hidden information in documents. The document containing the hidden information is issued subsequent to the printing step. At a later time and possibly in a different location, the document is subjected to heat either in a non-contact fashion as described in the prior examples, or through a contact heating process. After the application of heat, the document is inspected visually or via the use of electronic imaging equipment. The appearance of the hidden information pursuant to the heat treatment can be viewed as a proof of authenticity and the code that is revealed can be used as a key for other transactions such as a password or lottery number or can be checked against a second code printed in a different location. For authentication purposes, the mere effect that a bleed through feature appears after heat treatment can be viewed as a sign of authenticity.
Although carbon black was used in these examples as an efficient absorber for electromagnetic radiation in the infrared and visible spectrum, other compounds such as infrared radiation absorbing organic dyes or pigments, or inorganic infrared radiation absorbing materials can be used.
Typically, electromagnetic radiation for near-IR drying systems reaches maximum power at a wavelength (lambda max) of approximately 810 nm and the absorption spectrum of the absorbing material should overlap the spectrum of the electromagnetic radiation.
In one embodiment of the invention ink may be delivered by an inkjet printer. FIG. 13 illustrates schematically an exemplary inkjet printer 20 with a thin film of resistor 30 as the heat generating member of the inside surface of a pipe 29 . Electrodes 31 1 and 31 2 are formed on both ends of the pipe, and an orifice 32 is then mounted to one of the ends of the pipe, the fiber pipe is embedded in a heat sink 33 . Ink is supplied from an ink supplying means 34 , and square pulse of 5μ, sec. is applied to the heat generating member.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.
PARTS LIST
20 inkjet printer
29 pipe
30 resistor
31 1 electrode
31 2 electrode
32 orifice
33 heat sink
34 ink supplying means
100 printed substrate
102 print side of substrate
104 non-print side of substrate
106 first component of the ink (non migrating)
108 second component of the ink (migrating)
110 electromagnetic radiation including infrared radiation
120 area in the printed sheets that is subject to heating from the infrared dryer
140 symbols (letters and numbers) printed with an ink containing black and magenta colorant
142 symbols (letters and numbers) printed with an ink containing magenta colorant only | A system for printing information on a substrate includes a printer for printing the information on a first surface of the substrate; and a heater for heating the substrate causing at least a portion of the printed information to migrate to a second surface of the substrate. | 2 |
BACKGROUND OF THE INVENTION
The instant invention relates to eyeglasses in general and more specifically to eyeglass attachments that form a single functional unit with sunglasses or prescription glasses. The present invention is particularly directed towards a lightweight sun shield system for people who wear prescription eyeglasses. The sun shield component attaches to a slightly modified standard-style eyeglass frame (which thus can be fitted with standard size and shape prescription lenses) and provides further protection against ultraviolet and infrared rays as well as some protection from dust, debris, etc.
DESCRIPTION OF RELATED ART
Many attempts have been made to provide convenient to wear and use sun shields which will attach to conventional prescription eyeglasses to provide protection from the ultraviolet (UV) and infrared rays from the sun.
U.S. Pat. No. 3,171,869 to Weinberg describes a technique for making curved optical lenses. A curved eyeglass lens with UV-blocking/sun-glass properties can provide additional protection to the eyes. However, the technique is complex and requires an advanced process. Additionally, the curved lens would require new, more complex frame designs to mount the lenses. The curvature posteriorly adds another variable dimension to frame design and measurement.
U.S. Pat. No. 3,195,145 to Tisher et al provides a two lens system of a major protective lens and a smaller corrective lens. Significant features are that the corrective lens is mounted to fittings on the inner surface of the protective lens. The lens is fit into position with a heating technique. Optical properties are incorporated into the protective lens specific to the corrective lens used. Features for clasping a particular type corrective lens are designed into the corresponding protective lens.
With his invention, Tisher's goal is to optimize optical clarity, to create impact resistance to physical trauma, and to create a tight seal between the lenses which will prevent dirt and fluid contamination. He also wants his "spectacle lens system" to resemble everyday non-corrective sunglasses.
Although Tisher's device may reduce contamination between the tight-fitting lenses, his device is not readily dissembled when cleaning is required. More significant is that the corrective lens must be made specifically for this system. It must be made to fit into the mounting on the protective lens (which must also be made to match the type of corrective inner lens). The effort to manufacture this invention is refined, demanding, and somewhat complicated. Standardized frame sizes and current lens-making techniques can not be used to make Tisher's device. New lens-making technology is required. Since the lenses are substantially fixedly mounted into the outer shield, they can not be removed without access to a spanning wrench and a sand bath or heated air. Further Tisher's device offers virtually no ability to make available size and shape flexibility for individual variation.
U.S. Pat. No. 4,877,320 to Holden discloses eye-shielding glasses contoured to fit and completely cover the human eye area with a one-piece curved lens section provided with hinge-attached, removable temples. This invention offers the prescription lens wearer two pairs of eyeglasses worn simultaneously--i.e., one pair being worn over the other. This can be awkward, uncomfortable, unstable and so will not promote compliance with wearing a sun-shield.
U.S. Pat. No. 3,226,729 to Fucci discloses shields to be attached to the temple bars eyeglasses for protecting the eyes of the wearer from side lighting. Each shield comprises an elongated panel formed from a semi-rigid sheet material which is both transparent and tinted to filter out harmful components of the sun's rays. Since the shields must be attached to the temple bars before use, one must remember to carry them on one's person. Thus this is a three piece system which will quickly become tiring to assemble and use after a short time.
U.S. Pat. No. 3,932,031 to Johnston discloses a side shade attachable to the bow of a pair of spectacles and having a main portion hanging therebeneath but also a transverse shaped portion attached thereto and adapted to lap the adjacent side edge of a frame of the spectacles for preventing glare from coming to the wearer's eye from the area immediately rearward of the front of the spectacles. This is only a partial solution inasmuch as it does nothing to reduce UV and infrared radiation which enters through the lenses of the glasses to which the shades are attached.
U.S. Pat. No. 4,543,667 to Garbutt discloses a sun visor for attachment to a pair of eyeglass temples which includes a bill member having a flat, rigid stiffening member formed with a concave inner edge and a convex outer edge. Not directly covering the lenses of the glasses, this sun visor will only minimally reduce the UV and infrared radiation passing through the lenses of the glasses. This invention is primarily for reducing discomfort due to the glare from the sun.
None of these inventions provides a complete sunglass system for people who wear prescription eyeglasses. Further none of the background art inventions provides a combined sun shielding unit with a shield easily detachable from prescription eyeglasses, which shield is to provide enhanced UV and sun protection to the eye and proximal skin.
SUMMARY OF INVENTION, OBJECTS AND ADVANTAGES
Accordingly, the above mentioned problem is obviated by the present invention which provides a composite sunglass system for people who wear prescription eyeglasses. This system comprises a selection of substantially standard-size frames designed to accept a detachable sun shield. This sun shield is designed to provide enhanced UV and sun protection to the eye and proximal skin, over conventional, `prescription` sunglasses. The shields also offer a sequence of contour size and fit. Since the sun shield is readily removable, cleaning is facilitated when needed. This sun shield and the standard frame and lens system allow immediate utilization. By using standardized frame sizes, present lens-making techniques can be used. These methods are in current widespread use in the art so this system can be used immediately at standard costs. No new lens-making technology is required. Further a selection of shields could be provided so that facial fit could be optimized.
Additionally having a detachable sun shield allows not only `custom-fitting` the sun shield (by size and contour), but also the use of specialized shields (such as those for indoor and evening use). Since the eyeglass frame and detachable sun shield form a unit, the use of this unit is graceful, comfortable, stable, and conducive to continued use.
In particular when the instant invention is compared with the eyeglasses plus overglasses disclosed by the Holden patent, it can be seen that the one-piece composite unit of the instant invention is far less cumbersome and awkward to wear than eyeglasses plus overglasses. Especially when a doctor is prescribing a system with greater UV and sun protection, it can be seen that there will be greater compliance to the doctor's prescription by those who are to wear a one-piece system than by those who are to wear a two-piece system. Most people will find a two piece system very awkward to carry and to use. Further when the sun shield of the instant invention is removed from the eyeglasses, the result is a pair of virtually standard prescription eye glasses. And further, when the sun shield is upgraded as UV and other light-blocking materials and films improve, the upgraded sun shield can be used on the original eyeglass frame. Finally the sun shield is readily removable for thorough cleaning.
It is therefore an object of the present invention to provide a lightweight eyeglass sun shield to give better sun and UV protection for prescription eyeglass wearers.
A second object of this invention is to provide a lightweight sun shield which fits onto a substantially standard-style eyeglass frame which accepts standard prescription lenses.
A third object of this invention is to provide the eyeglass wearer with a single easy-to-carry and easy-to-use, comfortable, stable, one-piece functional unit--the eyeglasses and the sun shield forming one composite unit.
A fourth object of this invention is to provide a system which virtually becomes a standard pair of eyeglasses when the sun shield is removed.
A fifth object of this invention is to provide a sun shield which can easily be upgraded and used on the same frame as UV and other light-blocking materials and films improve.
A sixth object of this invention is to provide a sun shield which is readily removable without special tools so that it can easily be thoroughly cleaned.
A seventh object of this invention is to provide a sun shield with sufficient UV/sunlight blocking ability that no special UV/sunlight blocking quality need be built into the prescription lenses. And since the sun shield need not be designed to correct vision, the sun shield can be designed for optimum UV screening in terms of material and contouring around the face.
An eighth object of this invention is to provide a sun shield which fits over substantially conventional frames so that the frames can be sized to fit comfortably and securely for individual facial dimensions. The frame fits to the face, not the shield, and the shield fits to the frame. This allows a more precise alignment of the lens with the eye, which is critical in some prescriptions.
A ninth object of this invention is to provide a sun shield which can be made available in various sizes and contours to accommodate variations in facial shapes and taste and comfort, and the extent of shielding desired, thus allowing optimization of two aspects--frame fit and sun shield contour in one stable piece.
Further scope of applicability of the present invention will become apparent from the detailed description given hereafter. However, it should be understood that the drawings and the detailed description, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a diagrammatic perspective view illustrating a first embodiment of the instant invention in use.
FIG. 2 is a diagrammatic perspective exploded view thereof of the first embodiment per se.
FIG. 3 is a cross sectional view taken on line 3--3 of FIG. 1.
FIG. 4 is an elevational view taken in the direction of arrow 4 in FIG. 2 with parts broken away.
FIG. 5 is a diagrammatic perspective view illustrating a second embodiment of the instant invention in use.
FIG. 6 is a cross sectional view taken on line 6--6 of FIG. 5.
FIG. 7 is a diagrammatic perspective exploded view thereof of the second embodiment per se.
FIG. 8 is a diagrammatic perspective view illustrating a third embodiment of the instant invention in use.
FIG. 9 is a cross sectional view taken on line 9--9 of FIG. 8.
FIG. 10 is a diagrammatic perspective exploded view thereof of the third embodiment per se.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the various drawings, the Sun Shield Eyeglass System is generally shown as numeral 16 in FIG. 1. FIG. 1 shows the instant invention in use.
FIG. 2 shows a first embodiment of the instant invention. Here the sun shield component (generally shown as numeral 18) is shown removed from the eyeglass component (generally shown as numeral 20). The eyeglass component 20 will be described first. The crosspiece 22 holds the left rim 26 and the right rim 28. Each rim has a substantially flat upper surface and a bowed lower section 31. The two rims are in a spaced apart arrangement with respect to each other such that the crosspiece 22 and the two rims 26, 28 define a space 29 for the nose of the wearer. At each end of the upper surface of the crosspiece 22 are apertures 24 which define a bore which runs from the upper surface to and through the lower surface of the crosspiece 22. In the middle of the upper surface of the crosspiece is a positioning hole 25 which mates with a positioning pin 47 on the sun shield 18 in order to assist in holding the sun shield 18 in proper relationship to the eyeglasses 20. Between the apertures 24 and the positioning hole 25 on the upper surface of the crosspiece are patches of mating hook and loop pile fastener material 50. Mounted within the left and right rims 26, 28 are corrective lenses 30, 30. Attached at each end of the crosspiece 22 are hinges 32 (better shown in FIG. 3). Attached to each hinge are temple pieces 34, 34 each of which terminates in an ear piece 36.
As is shown in FIG. 2, the sun shield 18 is elongated and curve-shaped and terminates at its upper edge in a widened overhang 40, and is narrowed centrally along its lower edge by a bridge opening 42, and terminates at its left and right edges in curved side shielding 44, 44. Attached to, running the full length from left to right of, and projecting from the inner upper portion of the sun shield 18 is a ledge 46. At each end of the lower surface of the ledge 46 are downwardly projecting bifurcated pin members 48, 48 positionally matching the apertures 24, 24 at the two ends of the upper surface of the eyeglass crosspiece 22. In the middle of the lower surface of the ledge 46 is a downwardly projecting positioning pin 47 which, as before mentioned, positionally matches the positioning hole 25 in the middle of the upper surface of the eyeglass crosspiece 22. On the lower surface of the ledge 46 between each of the bifurcated pin members 48 and the positioning pin 47 are two patches of mating hook and loop pile fastener material 51 positionally matching the two sections of mating hook and loop pile fastener material on the upper surface of the eyeglass crosspiece 22.
FIG. 3 is a cross sectional view taken on line 3--3 of FIG. 1. FIG. 3 shows how a bifurcated pin member 48 secures the ledge 46 of the sun shield 18 to the crosspiece 22 of the eyeglasses. FIG. 3 also shows the hinge 32 which joins the temple piece 34 to the crosspiece 22 of the eyeglasses.
FIG. 4 shows in greater detail the positioning pin 47 and the two patches of mating hook and loop pile fastener material 51.
To remove the sun shield 18 from the eyeglasses 20, one would squeeze together the two prongs at the forked end of each of the two bifurcated pin members 48 and push the forked ends back through the apertures 24 in the crosspiece 22 of the eyeglasses.
FIG. 5 is a diagrammatic perspective view illustrating a second embodiment of the instant invention in use. In FIG. 5, the Sun Shield Eyeglass System is generally shown as numeral 51. In FIG. 7 the sun shield component (generally shown as numeral 52) is shown removed from the eyeglass component (generally shown as numeral 53). The eyeglass component 53 will be described first. The bridge 60 holds the left rim 54 and the right rim 55 in a spaced apart arrangement with respect to each other such that the bridge 60 and the two rims 54, 55 define a space 57 for the nose of the wearer. At the left edge of the left rim 54 and the right edge of the right rim 55 are two protuberances 56. In each protuberance there is an aperture 58 defining a bore which runs from the front surface to and through the rear surface of the protuberance 56. Mounted within the left and right rims 54, 55 are corrective lenses 62, 62. Attached to the upper left edge and the upper right edge of the left and right rims respectively 54, 55 are hinges 64, 64 (better seen in FIG. 6). Attached to each hinge 64 are temple pieces 66, 66 each of which terminates in an ear piece 68.
As is shown in FIG. 7, the sun shield 52 is elongated and curve-shaped and terminates at its upper edge in a widened overhang 72, and is narrowed centrally along its lower edge by a bridge opening 74, and terminates at its left and right edges in curved side shielding 78, 78. The section of the sun shield between the two curved side shielding sections 78, 78 will be referred to as the lens section 70. Attached to, running the full length from left to right of, and projecting from the inner upper portion of the sun shield 52 is a ledge 80. Near the left and right ends of the lens section 70 on its inner surface are two outwardly projecting bifurcated pin members 76, 76 positionally matching the apertures 58, 58 in the two protuberances 56, 56 on the left and right rims 54, 55.
FIG. 6 is a cross sectional view taken on line 6-6 of FIG. 5. FIG. 6 shows how a bifurcated pin member 76 secures the sun shield 52 to the protuberances 56, 56 on the eyeglass rims. FIG. 6 also shows the hinge 64 which joins the temple piece 66 to the rim 54 of the eyeglasses.
To remove the sun shield 52 from the eyeglasses 53, one would squeeze together the two prongs at the forked end of each of the two bifurcated pin members 76, 76 and push the forked ends back through the apertures 58, 58 in the protuberances 56, 56 on the left and right rims of the eyeglasses.
FIG. 8 is a diagrammatic perspective view illustrating a third embodiment of the instant invention in use. In FIG. 8, the Sun Shield Eyeglass System is generally shown as numeral 79. In FIG. 10 the sun shield component (generally shown as numeral 80) is shown removed from the eyeglass component (generally shown as numeral 81). The eyeglass component 81 will be described first.
The crosspiece 82 holds the left rim 84 and the right rim 92. Each rim has a substantially flat upper surface and a bowed lower section 90. The two rims are in a spaced apart arrangement with respect to each other such that the crosspiece 82 and the two rims 84, 92 define a space 93 for the nose of the wearer. At the left edge of the left rim 84 and the right edge of the right rim 92 are two protuberances 86, 86. In each protuberance there is an aperture 88 defining a bore which runs from the front surface to and through the rear surface of the protuberance 86. On the front surface of the crosspiece are two patches of mating hook and loop pile fastener material 114, 114. Mounted within the left and right rims 84, 92 are corrective lenses 94, 94. Attached at each end of the crosspiece 82 are hinges 96 (better seen in FIG. 9). Attached to each hinge are temple pieces 98, 98 each of which terminates in an ear piece 100.
As is shown in FIG. 10, the sun shield 80 is elongated and curve-shaped and terminates at its upper edge in a widened overhang 104, and is narrowed centrally along its lower edge by a bridge opening 106, and terminates at its left and right edges in curved side shielding 110,110. The section of the sun shield between the two curved side shielding sections 110,110 will be referred to as the lens section 102. Near the left and right ends of the lens section 102 on its inner surface are outwardly projecting bifurcated pin members 108, 108 positionally matching the apertures 88, 88 in the two protuberances 86, 86 on the left and right rims 84, 92. On the inner surface of the lens section 102 are two patches of mating hook and loop pile fastener material 112,112 positionally matching the two sections of mating hook and loop pile fastener material 114,114 on the front section of the eyeglass crosspiece 82.
FIG. 9 is a cross sectional view taken on line 9--9 of FIG. 8. FIG. 9 shows how a bifurcated pin member 108 secures the sun shield 80 to the protuberances 86 (better shown in FIG. 10) on the eyeglass rims 84, 92. FIG. 9 also shows the hinge 96 which joins the temple piece 98 to the crosspiece 82 of the eyeglasses.
To remove the sun shield 80 from the eyeglasses 81, one would squeeze together the two prongs at the forked end of each of the two bifurcated pin members 108 and push the forked ends back through the apertures 88, 88 in the protuberances 86, 86 on the left and right rims 84, 92 of the eyeglasses.
It is contemplated that the Sun Shield Eye Glass Attachment will be offered in a variety of colors, surface textures, print designs, coverings (leather, vinyl, etc.) and lengths for various size heads.
CONCLUSION, RAMIFICATIONS, AND SCOPE OF INVENTION
From the foregoing, it will be seen that I have provided a Sun Shield Eye Glass System to protect the eyes of a person who ordinarily wears prescription eyeglasses from the harmful UV and infrared rays in sunlight.
Thus the reader will see that my invention supplies a long felt need for a comfortable, easy to use Sun Shield Eye Glass System which combines in one unified system the most desired qualities and characteristics required to protect the eyes of the wearer from the harmful effects of the UV and infrared components of sunlight. There are many variations of this Sun Shield Eye Glass Attachment which can be made by those skilled in the art without departing from the inventive concepts expressed herein. Accordingly, the scope of my invention should be determined not by the embodiments described, but by the appended claims and their legal equivalents. | An eyeglass system comprising sunglasses or prescription eyeglasses and a detachable ultraviolet, infrared sun shield in one combined unit. The present invention is particularly directed towards a lightweight sun shield system for people who wear prescription eyeglasses. The sun shield component attaches to a slightly modified standard-style eyeglass frame (which thus can be fitted with standard size and shape prescription lenses) and provides further protection against ultraviolet and infrared rays as well as some protection from dust, debris, etc. | 6 |
This is a continuation of application Ser. No. 08/438,180, filed on May 9, 1995, U.S. Pat. No. 5,700,624.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the use of the novel polymers for the formulation of photoresists particularly suitable for deep U.V. exposure and having the capability of forming highly resolved features of submicron dimension.
2. Description of the Prior Art
Photoresists are photosensitive films used for transfer of images to a substrate. They form negative or positive images. After coating a photoresist on a substrate, the coating is exposed through a patterned photomask to a source of activating energy such as ultraviolet light to form a latent image in the photoresist coating. The photomask has areas opaque to activating radiation and other areas transparent to activating radiation. The pattern in the photomask of opaque and transparent areas defines a desired image that may be used to transfer the image to a substrate. A relief image is provided by development of the latent image patterned in the photoresist coating. The use of photoresists are generally described, for example, by Deforest, Photoresist Materials and Processes, McGraw Hill Book Company, N.Y. (1975), and by Moreau, Semiconductor Lithography, Principles, Practices and Materials, Plenum Press, N.Y. (1988).
Known photoresists can form features having resolution and size sufficient for many existing commercial applications. However for many other applications, the need exists for new photoresists that can provide highly resolved images of submicron dimension.
Highly useful photoresist compositions capable of fine line image resolution are disclosed in U.S. Pat. No. 5,128,232 to Thackeray et al. incorporated herein by reference. The patent discloses, inter alia, the use of a photoresist resin binder that comprises a copolymer of non-aromatic cyclic alcohol units and phenolic units. The disclosed photoresists are particularly suitable for exposure to deep U.V. (DUV) radiation. As is recognized by those in the art, DUV radiation refers to exposure of the photoresist to radiation having a wavelength in the range of about 350 nm or less, more typically in the range of about 300 nm or less.
A class of photoresists for which the copolymers of the non-aromatic cyclic alcohol and phenolic units are particularly suitable are the positive acting compositions that comprise a resin binder having an acid or base cleavable blocking group and a photobase or photoacid generator that generates base or acid respectively, upon exposure to activating radiation. It is know that some cationic photoinitiators have been used to induce selective photogenerated acid cleavage of certain blocking groups pendant from a photoresist binder, or cleavage of certain blocking groups that comprise a photoresist binder. See, for example, U.S. Pat. Nos. 4,968,581; 4,883,740; 4,810,613 and 4,491,628 and Canadian Patent Appln. No. 2,001,384, all of which are incorporated herein by reference for their teaching of the described binders and acid labile blocking groups, and for methods of making and using the same. Such cleavage is reported to create differential solubility characteristics in exposed and unexposed areas of the polymer. Upon selective cleavage of the blocking group through exposure of the photoresist, a polar functional group is said to be provided, for example, carboxyl, phenyl, or imide.
In U.S. Pat. No. 5,258,257, incorporated herein by reference, it is reported that high solubility differentials between exposed and unexposed regions of a coating layer of a photoresist composition are realized with only modest levels of substitution of acid labile blocking groups on a resin binder, for example, substitution of the labile groups for about 1% of the hydroxyl groups of the resin binder and preferably, 5 to 35% of the hydroxyl groups on the binder are blocked with acid labile groups. The binder used in this patent is preferably the above described copolymer of cyclic alcohol units and a phenol. In this patent, it is reported that the high solubility differential between exposed and unexposed regions with relatively low levels of blocking group substitution is possible because the cyclic alcohol units of the binder are less polar relative to the phenolic groups, effectively limiting the solubility of unexposed regions in aqueous alkaline developers, but enabling high solubility of those regions in suitable organic developers. Thus, in accordance with the invention set forth in said patent, a radiation sensitive composition is provided where a comparatively smaller mass of blocking groups is liberated upon photoinduced cleavage, thereby avoiding problems of prior systems such as shrinkage of the photoresist layer as a consequence of reduction in the mass of the resin binder by cleavage of the acid.
In accordance with U.S. Pat. No. 5,362,600, incorporated herein by reference, it is reported that by employing suitable blocking groups, a phenol-containing polymer binder comprising a high concentration of cyclic alcohol units may be employed. It is stated that this is accomplished by the highly polar groups that can be grafted onto the binder by the sequential steps of blocking at least a portion of the binder's hydroxyl groups, followed by acid catalyzed deprotection of the blocking groups. For example, acid catalyzed deprotection of a t-butyl acetate acid labile groups provide the acid ether moiety (--OCH 2 COOH). Such polar groups render exposed regions soluble in a polar developer thereby permitting increased concentrations of cyclic alcohol units in the polymer to 60 mole percent or greater of the total polymer without loss in the dissolution properties of the photoresist. This enables formulation of a photoresist having superior optical clarity properties.
An alternative to the method for forming positive tone photoresist images using acid labile blocking groups on a polymer involves the use of dissolution inhibitors having acid labile blocking groups. A dissolution inhibitor is a photoresist compatible component such as a phenol or bisphenol with pendant phenolic hydroxyl groups blocked with the acid labile group. In this embodiment, the acid labile group is substituted on the dissolution inhibitor rather than on the polymer. A sufficient amount of the dissolution inhibitor is used to insolubilize the otherwise alkali soluble phenolic component. Differential solubility is achieved in essentially the same manner as when the acid labile blocking group is substituted on the resin binder--namely, by exposure of a coating of the photoresist to activating radiation resulting in a photolysis reaction that releases acid which cleaves the acid labile blocking group on the dissolution inhibitor resulting in formation of an alkali soluble polar group that renders the photoresist soluble in light exposed areas of the photoresist coating.
It has been found that with substantial acid catalyzed deprotection of a photoresist coating, as a consequence of evolution of isobutylene during processing the photoresist coating, a dried film of the photoresist undergoes shrinkage during exposure and baking. This results in a lack of conformity between the transferred image and the desired image. In addition, it has been found that the photolithographic properties of a positive working photoresist using resins or dissolution inhibitors having phenolic hydroxyl groups blocked with acid labile groups undergo minor change during prolonged storage of the photoresist. It is believed that this may be due at least in part to instability of the acid labile groups and cleavage of a portion of these groups during storage and prior to use. Though the change in photolithographic properties during storage may be minor, because of the exacting specifications for such resists, even minor changes are undesirable for the fabrication of many electronic devices.
SUMMARY OF THE INVENTION
The subject invention relates to a positive acting photoresist composition comprising an acid generator and an alkali soluble resin having a portion of its phenolic hydroxyl groups blocked with an acid labile blocking group or an alkali soluble resin in combination with a dissolution inhibitor having at least a portion of its phenolic hydroxyl groups blocked with an acid labile group. In accordance with the invention, it has been found that the total number of acid labile groups required for adequate resolution may be reduced if inert blocking groups are substituted on the alkali soluble resin. If the photoresist utilizes an alkali soluble resin having acid labile groups substituted on the resin, then in that embodiment of the invention, the inert blocking groups are used in place of a portion of the acid labile groups. Unexpectedly, it has been found that a reduction in the number of acid labile blocking groups in the photoresist composition as a consequence of the use of inert blocking groups as described herein does not deleteriously effect the differential solubility properties of an exposed photoresist composition.
Based upon the above, the invention described herein comprises a positive working photoresist composition comprising a photoacid generator and an alkali soluble resin having ring substituted hydroxyl groups where a portion of the hydroxyl groups are blocked with an inert blocking group. In one embodiment of the invention, other of the hydroxyl groups on the alkali soluble resin are blocked with acid labile blocking groups. In a second embodiment of the invention, the resin having the inert blocking groups is used in combination with a dissolution inhibitor having acid labile blocking groups. Differential solubility in a coating of the photoresist is achieved by cleavage of acid labile groups resulting from photogenerated acid. In a further embodiment of the invention, both the resin and a dissolution inhibitor are provided with inert blocking groups.
The term "inert" as used in connection with the blocking groups is defined as chemically unreactive in the presence of acid generated during exposure and baking of the photoresist composition.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polymer binder of the invention may be a conventional alkali soluble resin typically used in positive acting photoresists such as a novolak resin or a polyvinylphenol resin. Preferably, the resin is a copolymer of phenolic and cyclic alcohol units. The most preferred polymers for purposes of this invention are those formed by the hydrogenation of a phenol formaldehyde (novolak) or a poly(vinylphenol) resin.
Procedures for the preparation of conventional novolak and poly(vinylphenol) resins used as photoresist binders are well known in the art and disclosed in numerous publications including those discussed above. Novolak resins are the thermoplastic condensation products of a phenol and an aldehyde. Examples of suitable phenols for condensation with an aldehyde, especially formaldehyde, for the formation of novolak resins include phenol; m-cresol; o-cresol; p-cresol; 2,4-xylenol; 2,5-xylenol; 3,4-xylenol; 3,5-xylenol and thymol. An acid catalyzed condensation reaction results in the formation of a suitable novolak resin which may vary in molecular weight from about 500 to 100,000 daltons. The preferred novolak resins conventionally used for the formation of photoresists are the cresol formaldehyde condensation products.
Poly(vinylphenol) resins are thermoplastic polymers that may be formed by block polymerization, emulsion polymerization or solution polymerization of the corresponding monomers in the presence of a cationic catalyst or free radical initiator. Vinylphenols useful for the production of poly(vinylphenol) resins may be prepared, for example, by hydrolysis of commercially available coumarin or substituted coumarins, followed by decarboxylation of the resulting hydroxy cinnamic acids. Useful vinylphenols may also be prepared by dehydration of the corresponding hydroxy alkyl phenols or by decarboxylation of hydroxy cinnamic acids resulting from the reaction of substituted or non-substituted hydroxybenzaldehydes with malonic acid. Preferred poly(vinylphenol) resins prepared from such vinylphenols have a molecular weight range of from abut 2,000 to about 100,000 daltons.
As noted above, preferred resins for purposes of this invention are copolymers of phenols and nonaromatic cyclic alcohols analogous in structure to the novolak resins or the poly(vinylphenol) resins. These copolymers may be formed in several ways. For example, in the conventional preparation of a poly(vinylphenol) resin, a cyclic alcohol may be added to the reaction mixture as a comonomer during the polymerization reaction which is thereafter carried out in normal manner. The cyclic alcohol is preferably aliphatic, but may contain one or two double bonds. The cyclic alcohol is preferably one closest in structure to the phenol. For example, if the resin is a poly(vinylphenol), the comonomer would be vinyl cyclohexanol.
The preferred method for formation of the polymer comprises partial hydrogenation of a preformed novolak resin or a preformed poly(vinylphenol) resin. Hydrogenation may be carried out using art recognized hydrogenation procedures, for example, by passing a solution of the phenolic resin over a reducing catalyst such as a platinum or palladium coated carbon substrate or preferably, over Raney nickel at elevated temperature and pressure. The specific conditions are dependent upon the polymer to be hydrogenated. More particularly, the polymer is dissolved in a suitable solvent such as ethyl alcohol or acetic acid and then the solution is contacted with a finely divided Raney nickel catalyst and allowed to react at a temperature of from about 100° to 300° C. at a pressure of from about 50 to 300 atmospheres or more. The finely divided nickel catalyst may be a nickel-on-silica, nickel-on-alumina, or nickel-on-carbon catalyst depending upon the resin to be hydrogenated. Hydrogenation is believed to reduce the double bounds in some of the phenolic units resulting in a random polymer of phenolic and cyclic alcohol units randomly interspersed in the polymer in percentages dependent upon the reaction conditions used.
A preferred polymer binder comprises units of a structure selected from the group consisting of: ##STR1## where each unit (I) represents a phenolic unit and unit (II) represents a cyclic alcohol unit; Z is an alkylene bridge having from 1 to 3 carbon atoms; A is a substituent on the aromatic ring replacing hydrogen such as lower alkyl having from 1 to 3 carbon atoms, halo such as chloro or bromo, alkoxy having from 1 to 3 carbon atoms, hydroxyl, nitro, amino, etc.; a is a number varying from 0 to 4; B is a substituent, such as hydrogen, lower alkyl having from 1 to 3 carbon atoms, halo such as chloro or bromo, alkoxy having from 1 to 3 carbon atoms, hydroxyl, nitro, amino, etc. provided that at least 3 of said B substituents are hydrogen; b is an integer varying between 6 and 10; x is the mole fraction of the units (I) in the polymer, y is the mole fraction of units (II) in the polymer and x+y equals 1.
To use the above binders in a photoresist composition, at least a portion of the available hydroxyl groups on the above polymer binder are bonded to suitable acid labile blocking groups. Suitable blocking groups in general are those that upon photocleavage provide a moiety that is more polar than hydroxyl. Further, the acid labile groups should generally be stable to any pre-exposure soft bake and should not substantially interfere with photoactivation of the composition.
In the above polymer, the percentage of cyclic alcohol units of the polymer preferably is not so high as to prevent development of an exposed film layer of the radiation sensitive composition in a polar developer solution. The polymer may have major portion of phenolic units and a minor portion of cyclic alcohol units, i.e., less than about 50 mole percent of cyclic alcohol units. However, as it has been found that transparency of the composition increases as the concentration of cyclic alcohol units in the polymer binder increases. Therefore, in certain instances, it may be desirable to employ a polymer having a major portion of cyclic alcohol units and a minor portion of phenolic units. This can be achieved by using blocking groups which upon acid catalyzed hydrolysis, provides polar functional groups rendering exposed regions more soluble in polar developer solutions. Thus, to provide a radiation sensitive composition having high transparency, the percentage of cyclic alcohol units of the subject polymer binder may be about 50 mole percent; to further enhance clarity of the composition, the percentage of cyclic alcohol groups may be about 60 mole percent; and to still further enhance the transparency of the composition, the percentage of cyclic alcohol groups may be about 70 percent or greater of the total polymer binder. Accordingly, x the mole fraction of units (I) in the polymer represented in the above formula may vary between about 0.30 and 0.99 and preferably varies between about 0.50 and 0.90; and y, the mole fraction of units (II) in the above polymer, may vary between 0.01 and 0.70 and preferably varies between about 0.10 and 0.30.
In that embodiment of the invention utilizing a resin having acid labile blocking groups, the acid labile blocking groups are generally employed by a condensation reaction with a compound that comprises an acid labile group to form polymers having the following general formulas: ##STR2## where A, a, B, b, Z and x and y are as defined above, x' and y' represent the mole fraction of the units having the acid labile group R, as defined below, and each varies between 0.01 and 0.5 and more preferably between 0.05 and 0.35. An alternative means for defining the above ranges is to state that preferably from about 1 to 50% of the total pendant hydroxyl groups on the polymer are condensed with acid labile groups, and more preferably, from about 5 to 35% of the total hydroxyl groups on the polymer are condensed with the acid labile blocking groups.
The acid labile group is typically formed on the polymer by an alkaline condensation reaction between the preformed polymer and a compound that comprises the acid labile group and a suitable leaving group, for example, a halogen such as bromide or chloride. For example, where R is a preferred t-butoxy carbonyl methyl group, t-butyl haloacetate (e.g., t-butyl chloroacetate) is added to a solution of the polymer and a suitable base, and the mixture stirred typically with heating. A variety of bases may be employed for this condensation reaction including hydroxides such as sodium hydroxide and alkoxides such as potassium t-butoxide. The condensation reaction is typically carried out in an organic solvent. A variety of organic solvents are suitable as should be apparent to those skilled in the art. Tetrahydrofuran, acetone and dimethylformamide are preferred solvents. Suitable conditions of the condensation reaction can be determined based upon the constituents used. For example, an admixture of sodium hydroxide, t-butylchloroacetate and a partially hydrogenated poly(vinylphenol) is stirred for about 15 to 20 hours at about 70° C.
The percent substitution on the polymer binder with the acid labile group can be controlled by the amount of the acid labile compound that is condensed with the binder. The preferred substitution of hydroxyl sites on the polymer binder can readily be ascertained by proton and 13C NMR.
Though constituting a lesser preferred embodiment of the invention, the polymer binder can be condensed with mixtures of two or more compounds to form acid labile groups to provide a mixture of acid labile groups bonded pendant to the polymer backbone. If the polymer is condensed with two or more acid labile groups, then groups R of the above formula will be a mixture of different groups. For example, if the subject polymer of phenolic groups and cyclic alcohol groups is first condensed with a compound of formula R 1 and then condensed with a compound of the formula R 2 , where R 1 and R 2 of said formula are two different acid labile moieties and the polymer with comprise a mixture of R 1 and R 2 acid labile groups.
When a photoresist comprising a polymer having the acid labile groups and a photoacid generator are exposed to radiation of the appropriate wavelength, an acid is produced which cleaves the acid labile group to form a polar group enabling development of the photoresist in a suitable developer. Suitable photoacid generating compounds are described below and are generally well-known to those skilled in the art.
It has been found that the acid labile groups add predominantly to the more reactive phenolic groups rather than the cyclic alcohol groups of the above described polymer binders when a base such as sodium hydroxide is employed in the condensation reaction. That is, primarily only the phenolic groups of the binder are bonded to the above defined R groups and the cyclic alcohol groups are substantially free of acid labile groups. It is believed that acid labile groups will add to both the phenolic a cyclic alcohol groups of the binder by use of stronger bases such as butyl lithium or alkyl lithium reagents.
Suitable acid labile groups include acetate groups such as acetate groups of the formula --CR 1 R 2 C--(═O)--O--R 3 , where R 1 and R 2 are each independently selected from the group of hydrogen, an electron withdrawing group such as halogen, lower alkyl having from 1 to about 10 carbon atoms, and substituted lower alkyl having from 1 to about 10 carbon atoms; and R 3 is substituted and unsubstituted lower alkyl having from 1 to about 10 carbon atoms, substituted and unsubstituted aryl having form 1 to about 10 carbon atoms, substituted or unsubstituted benzyl having 7 to about 13 carbon atoms. The substituents can be, for example, one or more halogen, lower alkyl, lower alkoxy, aryl or benzyl. R 1 and R 2 suitably are each hydrogen. It has been found that if R 1 and/or R 2 are halogen or other suitable electron-withdrawing group, upon acidic cleavage of the acetate group a highly polar moiety is provided along with enhanced solubility differentials between exposed and unexposed regions of a coating layer of the subject composition. The difluoro group (i.e., R 1 and R 2 both fluoro) is particularly suitable for such purposes and provides extremely high dissolution differentials between exposed and unexposed regions with only modest levels of substitution of hydroxy groups of the polymer binder. This difluoro group can be provided by alkaline condensation of the polymer with t-butyl chlorodifluoroacetate (ClCF 2 C(═O)OC(CH 3 ) 3 ). As noted above, R 3 is preferably tert-butyl (i.e., R is the tert-butyl acetate group). Acid degradation of this group liberates isobutylene to provide the polar acetic acid ether moiety pendant to the polymer backbone.
It is understood that a wide range of acid labile groups are suitable, including many of the groups described in the patents incorporated herein by reference. For example, suitable acid labile groups include oxycarbonyl groups of the formula --C(═O)--O--R 3 , where R 3 is the same as defined above. Preferably, R 3 is tert-butyl or benzyl (i.e., R is the t-butoxy carbonyl or benzyloxy carbonyl group).
In accordance with the invention, in addition to blocking a portion of the hydroxyl groups with an acid labile group, a fraction of the hydroxyl groups are also blocked with an inert blocking group whereby the resultant preferred polymer of the invention will have the following structures: ##STR3## where A, a, B, b, Z, x, y, x+y equals 1, x' and y' are as defined above, x" and y" represent the mole fraction of inert blocking groups, and I represents the inert blocking group. Preferably, the total of the pendant hydroxyl groups blocked with the combination of the acid labile group and the inert blocking group is within the same limits set forth above for the blocked hydroxyl groups, that is the mole fraction of blocked hydroxyl groups on the binder varies from about 0.01 to 0.5 and more preferably, the mole fraction of blocked hydroxyl groups varies between about 0.05 and 0.35. In other words, the total of x'+y'+x"+y" does not exceed 0.5. The relative proportion of acid labile groups to inert blocking groups can be seen from the following table:
______________________________________ Broad Preferred______________________________________x' + y' 0.00-0.45 0.05-0.30x" + y" 0.05-0.25 0.05-0.10x' + y ' + x" + y" 0.10-0.50 0.15-0.35______________________________________
With respect to the above table, x'+y' may be 0 when the system utilizes a separate dissolution inhibitor such as a blocked alcohol or the photoacid generator itself.
In a lesser preferred embodiment of the invention, the resin may be a conventional alkali soluble resin such as a novolak or poly(vinylphenol) phenol resin. In this embodiment of the invention, the resultant polymer would have a formula corresponding to one of the following structures: ##STR4## where A, a, x', x", Z, R and I are as defined above and the relative proportion of acid labile groups to inert blocking groups would be as defined in the table above where y' and y" are 0.
Any blocking group inert to generated acid at temperatures used to bake a photoresist and which does not interfere with the photolithographic reaction within the photoresist is suitable for purposes of the invention. Typical examples of suitable blocking groups include alkoxy groups such as methoxy, ethoxy, propoxy, n-butoxy, sec-butoxy, t-butoxy, etc.; alkyl esters represented by RCOO-- where R is preferably an alkyl group having 1-4 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, etc.; sulfonyl acid esters such as methane sulfonyl, ethane sulfonyl, propane sulfonyl, benzene sulfonyl and toluene-sulfonyl esters, etc.
In a lesser preferred embodiment of the invention, the condensation reaction used to substitute the acid labile blocking group onto the resin may also be used to substitute the inert blocking group onto the resin. Moreover, the inert blocking group may be substituted onto the resin simultaneously with the acid labile blocking group by providing a solution containing a mixture of reactants comprising the inert blocking group and the acid labile blocking group. The concentration of each substituted onto the resin may be controlled by the concentration of each in its reaction solution. However, it is desirable that the acid labile group and inert blocking group be substituted onto the resin sequentially rather than simultaneously with the inert blocking group substituted onto the resin first followed by the acid labile blocking group.
In an alternative embodiment of the invention, the polymer having the inert blocking groups are used in combination with a dissolution inhibitor having acid labile groups substituted thereon. In this embodiment of the invention, the dissolution inhibitor insolubilizes the resin. Upon exposure to activating radiation, the acid labile blocking groups are converted to polar groups by the photogenerated acid thus solubilizing the resin in alkali developer.
The dissolution inhibitor used may be any of the alcohol backbones used for the formation of photoactive compounds known to the prior art. Such alcohols include, by way of example, hydroquinone, resorcinol, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxy benzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2'4,4'-tetrahydroxybenzophenone, 2,3,4,2',4'-pentahydroxybenzophenone, 2,3,4,2',6'-pentahydroxybenzophene, 2,3,4,3',4',5'-hexahydroxybenzophenone, 2,4,6,3',4',5'-hexahydroxy-5-chlorobenzophenone, and 2,3,4,3',4',5'-hexahydroxy-5-benzoyl benzophenone, bis(3,4-dihydroxyphenyl) methane, 2,2-bis(2,4-dihydroxyphenyl) propane and 2,2-bis(2,3,4-trihydroxyphenyl) propane, bis(2,4-dihydroxyphenyl)methane, bis(2,3,4-trihydroxyphenyl)methane, 2,2-bis(2,4-dihydroxyphenyl)propane, 2,2-bis(2,3,4-trihydroxyphenyl)-propane, resorcinol, pyrogallol, glucinol, 2,4-dihydroxy phenolpropylketone, 2,4-dihydroxyphenyl-N-hexylketone, 2,3,4-trihydroxyphenyl-N-hexylketone, 3,4,5-trihydroxybenzoic ester, bis(2,4-dihydroxy benzoyl) methane, bis (2,3,4-trihydroxybenzoyl) methane, bis (2,4,6-trihydroxybenzoyl) methane, p-bis(2,5-dihydroxybenzoyl) benzene, p-bis(2,3,4-trihydroxybenzoyl) benzene and p-bis(2,4,6-trihydroxybenzoyl), ethyleneglycol di(3,5-dihydroxybenzoate), ethyleneglycol di(3,4,5-trihydroxybenzoate), 1,4-butanediol(3,4,5-trihydroxybenzoate) 1,8-octanediol, di (3,4,5-trihydroxybenzoate), polyethyleneglycol di (polyhydroxybenzoate), and triethyleneglycol di (3,4,5-trihydroxybenzoate).
The alcohol is converted to a dissolution inhibitor by reaction of the acid labile group with the hydroxyl group of the alcohol. The acid labile groups and reaction mechanisms described above are used to form the dissolution inhibitor. In this embodiment of the invention, the dissolution inhibitor is combined with the resin having the inert blocking group in an amount sufficient to insolubilize the resin. In general, the weight ratio of the resin to the dissolution inhibitor may vary between 2:1 to 10:1 and more preferably, between 3:1 and 6:1.
It should be understood that in a further embodiment of the invention, a photoresist can be formulated using a resin having both inert blocking groups and acid labile groups together with a dissolution inhibitor having the acid labile groups.
The polymer binders described above with or without the dissolution inhibitors are used in an acid catalyzed photoresist system comprising as additional ingredients, a photoacid generator and other components commonly found in such formulations such as sensitizers, anti-striation agents, etc. The photoacid generator may be chosen from a wide variety of compounds known to form an acid upon exposure to activating radiation. One preferred class of radiation sensitive compositions of this invention are compositions that use the copolymer of the phenol and cyclic alcohol substituted with acid labile groups as a binder and an o-quinone diazide sulfonic acid ester as a radiation sensitive component. The sensitizers most often used in such compositions are naphthoquinone diazide sulfonic acids such as those disclosed by Kosar, Light Sensitive Systems, John Wiley & Sons, 1965, pp. 343 to 352, incorporated herein by reference. These sensitizers form an acid in response to radiation of different wavelengths ranging from visible to X-ray. Thus, the sensitizer chosen will depend in part, upon the wavelengths used for exposure. By selecting the appropriate sensitizer, the photoresists can be imaged by deep UV, E-beam, laser or any other activating radiation conventionally used for imaging photoresists. Preferred sensitizers include the 2,1,4-diazonaphthoquinone sulfonic acid esters and the 2,1,5-diazonaphthoquinone sulfonic acid esters.
Other useful acid generator include the family of nitrobenzyl esters, and the s-triazine derivatives. Suitable s-triazine acid generators are disclosed, for example, in U.S. Pat. No. 4,189,323, incorporated herein by reference.
Non-ionic photoacid generators are suitable including halogenated non-ionic, photoacid generating compounds such as, for example, 1,1-bis p-chlorophenyl!-2,2,2-trichloroethane (DDT); 1,1-bis p-methoxyphenyl!-2,2,2-trichloroethane; 1,2,5,6,9,10-hexabromocyclododecane; 1,10-dibromodecane; 1,1-bis p-chlorophenyl!-2,2-dichloroethane; 4,4-dichloro-2-(trichloromethyl) benzhydrol (Kelthane); hexachlorodimethyl sulfone; 2-chloro-6-(trichloromethyl) pyridine; O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl)phosphorothionate; 1,2,3,4,5,6-hexachlorocyclohexane; N(1,1-bis p-chlorophenyl!-2,2,2-trichloroethyl)acetamide; tris 2,3-dibromopropyl!isocyanurate; 2,2-bis p-chlorophenyl!-1,1-dichioroethylene; tris trichloromethyl!s-triazine; and their isomers, analogs, homologs, and residual compounds. Suitable photoacid generators are also disclosed in European Patent Application Nos. 0164248 and 0232972, both referenced above.
Acid generators that are particularly preferred for deep U.V. exposure include 1,1-bis(p-chlorophenyl)-2,2,2- trichloroethane (DDT); 1,1-bis(p-methoxyphenol)-2,2,2-trichloroethane; 1,1-bis(chlorophenyl)-2,2,2 trichloroethanol; tris(1,2,3-methanesulfonyl)benzene; and tris(trichloromethyl)triazine.
Onium salts are also suitable acid generators. Onium salts with weakly nucleophilic anions have been found to be particularly suitable. Examples of such anions are the halogen complex anions of divalent to heptavalent metals or non-metals, for example, Sb, Sn, Fe, Bi, Al, Ga, In, Ti, Zr, Sc, D, Cr, Hf, and Cu as well as B, P, and As. Examples of suitable onium salts are diaryl-diazonium salts and onium salts of group Va and B, Ia and B and I of the Periodic Table, for example, halonium salts, quaternary ammonium, phosphonium and arsonium salts, aromatic sulfonium salts and sulfoxonium salts or selenium salts. Examples of suitable preferred onium salts can be found in U.S. Pat. Nos. 4,442,197; 4,603,101; and 4,624,912, all incorporated herein by reference.
Another group of suitable acid generators is the family of sulfonated esters including sulfonyloxy ketones. Suitable sulfonated esters have been reporting in J. of Photopolymer Science and Technology, vol. 4, No. 3,337-340 (1991), incorporated herein by reference, including benzoin tosylate, t-butylphenyl alpha-(p-toluenesulfonyloxy)-acetate, and t-butyl alpha-(p-toluenesulfonyloxy)-acetate.
The compositions of the invention are generally prepared following prior art procedures for the preparation of photoresist compositions with the exception that the polymer binder with the blocking group as described herein is substituted at least in part for the conventional resins used in the formulation of such photoresists. The compositions of the invention are formulated as a coating composition by dissolving the components of the composition in a suitable solvent such as, for example, a glycol ether such as 2-methoxyethyl ether (diglyme), ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether; a Cellosolve ester such as methyl Cellosolve acetate; an aromatic hydrocarbon such as toluene or xylene; or a ketone such as methyl ethyl ketone. Typically, the solids content of the composition varies between about 5 and 35 percent by weight of the total weight of the radiation sensitive composition.
The compositions of the invention are used in accordance with generally known procedures though exposure and development conditions may vary as a consequence of improved photospeed and altered solubility in developer. The liquid coating compositions of the invention are applied to a substrate such as by spinning, dipping, roller coating or other conventional coating technique. When spin coating, the solids content of the coating solution can be adjusted to provide a desired film thickness based upon the specific spinning equipment utilized, the viscosity of the solution, the speed of the spinner and the amount of time allowed for spinning.
The composition is applied to a substrate conventionally used in processes involving coating with photoresists. For example, the composition may be applied over silicon or silicon dioxide wafers for the production of microprocessors and other integrated circuit components. Aluminum-aluminum oxide and silicon nitride wafers can also be coated with the photocurable compositions of the invention as a planarizing layer or for formation of multiple layers in accordance with art recognized procedures.
Following coating of the photoresist onto a surface, it is dried by heating to remove the solvent until preferably the photoresist coating is tack free. Thereafter, it is imaged through a mask in conventional manner. The exposure is sufficient to effectively activate the photoactive component of the photoresist system to produce a patterned image in the resist coating layer and, more specifically, the exposure energy typically ranges from about 10 to 300 mJ/cm 2 , dependent upon the exposure tool and the components of the photoresist composition.
A wide range of activating radiation can be suitably employed to expose the photoacid or photo-base generating compositions of the invention, including radiation of wavelengths anywhere in the range of from about 240 to 700 nm. As noted above, the compositions of the invention are especially suitable for deep UV exposure. The spectral response of the compositions of invention can be expanded by the addition of suitable radiation sensitize compounds to the composition as would be apparent to those skilled in the art.
Following exposure, the film layer of the composition is preferably baked at temperatures ranging from about 70° C. to about 140° C. Thereafter, the film is developed. The exposed resist film is rendered positive working by employing a polar developer, preferably an aqueous based developer such as an inorganic alkali exemplified by sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, sodium metasilicate; quaternary ammonium hydroxide solutions such as a tetra-alkyl ammonium hydroxide solution; various amine solutions such as ethyl amine, n-propyl amine, diethyl amine, di-n-propyl amine, triethyl amine or, methyldiethyl amine; alcohol amines such as diethanol amine or triethanol amine; cyclic amines such as pyrrole, pyridine, etc. The developer strength can be higher using the modified resins in accordance with this invention compared to the resins used in the prior art in such compositions. Typically, developer strength can exceed 0.2N TMAH and typically can be as high as 0.3N TMAH with 0.26N TMAH being preferred.
Following development of the photoresist coating over the substrate, the developed substrate may be selectively processed on those areas bared of resist, for example by chemically etching or plating substrate areas bared of resist in accordance with procedures known in the art. For the manufacture of microelectronic substrates, for example, the manufacture of silicon dioxide wafers, suitable etchants include a plasma gas etch and a hydrofluoric acid etching solution. The compositions of the invention are highly resistant to such etchants thereby enabling manufacture of highly resolved features, including lines with submicron widths. After such processing, resist may be removed from the processed substrate using known stripping procedures.
The following examples are illustrative of the invention.
GENERAL COMMENTS
In the examples, the hydrogenated poly(vinylphenol) resin used was PHM-C grade obtained from Maruzen Oil of Tokyo, Japan. The degree of hydrogenation of these poly(p-vinylphenols) is expressed as a percentage of aromatic double bonds converted to single bonds, or equivalently as a percentage of hydroxyphenyl groups converted to hydroxycyclohexyl groups. All temperatures used throughout this disclosure are in degrees Celsius.
EXAMPLE 1
This example demonstrates that a positive tone resist image is obtained from the following photoresist and process free of acid labile blocking groups. In this system, the photoacid generator is also a functionally suitable dissolution inhibitor. The mesyl group on the polymer is the inert blocking group. Materials used to prepare the photoresist for this example are set forth below in parts by weight:
______________________________________Ethyl lactate (solvent) 83.97Poly(p-vinyl)phenol being 10% hydrogenated 15.38and 9% blocked with Mesyl groupsTrisaryl sulfonium triflate 0.62Polymethylsiloxane.sup.a 0.03______________________________________ .sup.a Silwet L7604 (Union Carbide Co.)
The photoresist was spin-coated onto bare silicon wafers (vapor-primed with HMDS) for 30 seconds, then softbaked at 90° C. for 60 seconds on a vacuum hotplate yielding a film of 0.54 micron thickness as determined by a Prometrix film thickness monitor. A GCA 0.35 NA excimer laser stepper was used to expose the coated wafers in a grid pattern with a varying exposure dose. The wafers were then immediately developed by immersion in 0.21 Normal tetramethylammonium hydroxide with an added surfactant (Shipley® MF-702) for 35 seconds. A resulting positive tone image was formed with the film thickness being inversely proportional to the exposure dose. The dose allowing complete clearing of the resist film was found to be 80 mJ/cm 2 . A film thickness loss of 10% was found in the unexposed areas. It is significant to note that no post exposure baking was necessary to achieve the positive tone image.
EXAMPLE 2
Example 1 was repeated except that the developer strength was increased to 0.26 Normal. The results obtained were similar to those in Example 1 except that the dose allowing complete clearing of the resist was found to be 50 mJ/cm 2 . There was a film thickness loss in the unexposed areas of 25%.
______________________________________Ethyl Lactate (solvent) 83.97Poly(p-vinyl)phenol being 10% hydrogenated 15.38and 9% blocked with Mesyl groupsTris -aryl sulfonium triflate 0.62Polymethylsiloxane.sup.a 0.03______________________________________ .sup.a Silwet L7604 (Union Carbide Co.)
EXAMPLE 3
The addition of an acid labile ester to the formulation as a dissolution inhibitor improves the contrast and resolution of the photoresist while minimizing the unexposed film thickness loss. Materials used to prepare the photoresist for this example are set forth below, in parts by weight:
______________________________________Ethyl Lactate (solvent) 83.14Poly(p-vinyl)phenol being 10% hydrogenated 14.68and 9% blocked with Mesyl groupst-Butyl Acetate blocked trihydroxyphenyl- 0.74ethaneTris-aryl sulfonium triflate 0.59Propylene glycol monomethyl ether acetate 0.82Polymethylsiloxane.sup.a 0.03______________________________________ .sup.a Silwet L7604 (Union Carbide Co.)
The photoresist was spin-coated onto bare silicon wafers (vapor-primed with HMDS) for 30 seconds, then softbaked at 110° C. for 60 seconds on a vacuum hotplate yielding a film of 0.54 micron thickness as determined by a Prometrix film thickness monitor. A GCA 0.35 NA excimer laser stepper was used to expose the coated wafers to a masking array of line space pairs with varying dimensions down to 0.25 μm at various exposure doses. The wafers were then post exposure baked on a vacuum hotplate at 90° C. for 60 s and developed by immersion in 0.21 Normal tetramethylammonium hydroxide with an added surfactant (Shipley® MF-702) for 120 s. There was a resulting positive tone image. Optical microscopy revealed 0.42 μm line space pairs were resolved at an exposure does of 25 mJ/cm 2 . There was a film thickness loss of 13% in unexposed areas of the photoresist.
EXAMPLE 4
This example illustrates the use of a polymer containing both inert and acid labile blocking groups which improves contrast and resolution of a photoresist while minimizing unexposed film thickness loss.
A photoresist was prepared having the following composition, in parts by weight:
______________________________________Ethyl lactate (solvent) 83.96Poly(p-vinyl)phenol being 10% hydrogenated 15.42and 5% blocked with Mesyl groups and 10%blocked with t-butylacetate groups.Tris-aryl sulfonium triflate 0.59Polymethyl siloxane.sup.a 0.03______________________________________ .sup.a Silwet L7604 (Union Carbide Co.)
The photoresist was spin-coated onto bare silicon wafers (vapor-primed with HMDS) for 30 seconds, then softbaked at 100° C. for 60 seconds on a vacuum hotplate yielding a film of 0.80 micron thickness as determined by a Prometrix film thickness monitor. A GCA 0.35 NA excimer laser stepper was used to expose the coated wafers to a masking array of line space pairs with varying dimensions down to 0.25 μm at various exposures. The wafers were then post exposure baked on a vacuum hot plate at 90° C. for 60 seconds and developed by immersion in 0.26 Normal tetramethylammonium hydroxide with an added surfactant (Shipley® MF-702) for 120 seconds. There was a resulting positive tone image. Optical microscopy revealed that 0.36 μm line space pairs were resolved at an exposure does of 35 mJ/cm 2 . There was a film thickness loss of 5% in the unexposed areas of the photoresist. | The invention comprises an acid hardened resist system consisting of a resin binder having acid labile blocking groups and inert blocking groups and a photoacid generator. The inclusion of inert blocking groups on the resin improves shelf life without deleteriously affecting photolithographic properties of the resist. | 8 |
BACKGROUND OF THE INVENTION
The semiconductor fabrication industry continues to demand novel metal source containing precursors for chemical vapor deposition processes including atomic layer deposition for fabricating conformal metal containing films on substrates such as silicon, metal nitride, metal oxide and other metal-containing layers using these metal-containing precursors.
BRIEF SUMMARY OF THE INVENTION
This invention is directed to metal containing tridentate β-ketoiminates and solutions wherein the tridentate β-ketoiminates incorporate nitrogen or oxygen functionality in the imino group. The tridentate β-ketoiminates are selected from the group represented by the structures:
wherein M is a metal having a valence of from 2 to 5. Examples of metals include calcium, magnesium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, vanadium, tungsten, manganese, cobalt, iron, nickel, ruthenium, zinc, copper, palladium, platinum, iridium, rhenium, and osmium. A variety of organo groups may be employed as for example wherein R 1 is selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, and aryl, having from 1 to 10 carbon atoms, preferably a group containing 1 to 6 carbon atoms; R 2 is selected from the group consisting of hydrogen, alkyl, alkoxy, cycloaliphatic, and aryl; R 3 is selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, and aryl; R 4 is a C 3-10 branched alkylene bridge having at least one chiral carbon atom, preferably a group containing 3 or 4 carbon atoms, thus making a five- or six-membered coordinating ring to the metal center; R 5-6 are individually selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, aryl, and they can be connected to form a ring containing carbon, oxygen, or nitrogen atoms. The subscript n is an integer and equals the valence of the metal M.
wherein M is a metal ion selected from Group 4, 5 metals including titanium, zirconium, and hafnium; wherein R 1 is selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, and aryl, preferably a group containing 1 to 6 carbon atoms; R 2 is selected from the group consisting of hydrogen, alkyl, alkoxy, cycloaliphatic, and aryl; R 3 is selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, and aryl; R 4 is a C 3-10 branched alkylene bridge having at least one chiral carbon atom, preferably a group containing 3 or 4 carbon atoms, thus making a five- or six-membered coordinating ring to the metal center; R 5-6 are individually selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, aryl, and they can be connected to form a ring containing carbon, oxygen, or nitrogen atoms; R 7 is selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, and aryl; wherein m and n are at least 1 and the sum of m+n is equal to the valence of the metal.
Several advantages can be achieved through these metal-containing tridentate β-ketoiminates as precursors for chemical vapor deposition or atomic layer deposition, and these include:
an ability to form reactive complexes in good yield; an ability to form monomeric complexes, particularly calcium and strontium complexes, coordinated with one kind of ligand, thus allowing one to achieve a high vapor pressure; an ability to significantly increase the thermal stability of resulting metal complexes via introduction of branched alkylene bridge having at least one chiral carbon atom between the two nitrogen atoms compared to those without chiral centers between the two nitrogen atoms an ability to produce highly conformal metal thin films suited for use in a wide variety of electrical applications; an ability to form highly conformal metal oxide thin films suited for use in microelectronic devices; an ability to enhance the surface reaction between the metal-containing tridentate β-ketoiminates and the surface of a substrate due to the high chemical reactivity of the complexes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing representative of the crystal structure of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium.
FIG. 2 is thermogravimetric analysis (TGA) diagrams of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium (solid line) vs bis(2,2-dimethyl-5-(dimethylaminoethyl-imino)-3-hexanonato-N,O,N′)strontium (dashed line), indicating the new Sr complex with a chiral center (solid line) is much more stable than that without chiral center between the two nitrogen atoms (dashed line), thus leaving almost no residue.
FIG. 3 is a drawing representing the crystal structure of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)nickel.
FIG. 4 is thermogravimetric analysis (TGA) diagrams of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)nickel (solid line) vs bis(2,2-dimethyl-5-(dimethylaminoethyl-imino)-3-hexanonato-N,O,N′)nickel (dashed line), indicating the new Ni complex with a chiral center (solid line) is much more stable than that without chiral center between the two nitrogen atoms (dashed line), thus leaving less than 2% residue.
FIG. 5 is comparison of vapor pressure of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium (solid line) vs bis(2,2-dimethyl-5-(dimethylaminoethyl-imino)-3-hexanonato-N,O,N′)strontium (dashed line), indicating the new Sr complex with a chiral center (solid line) is more volatile than that without chiral center between the two nitrogen atoms (dashed line) although the molecular weight of bis(2,2-dimethyl-5-(dimethylaminoethyl-imino)-3-hexanonato-N,O,N′)strontium is smaller than bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium.
DETAILED DESCRIPTION OF THE INVENTION
This invention is related to metal-containing tridentate β-ketoiminate precursors and their solutions which are useful for fabricating conformal metal containing films on substrates such as silicon, metal nitride, metal oxide and other metal layers via deposition processes, e.g., CVD and ALD. Such conformal metal containing films have applications ranging from computer chips, optical device, magnetic information storage, to metallic catalyst coated on a supporting material. In contrast to prior tridentate β-ketoiminate precursors, the tridentate β-ketoiminate ligands incorporate at least one amino organo imino functionality which is in contrast to the literatures reported alkoxy group as the donating ligand, most importantly they contain a branched alkylene bridge having at least one chiral carbon atom between the two nitrogen atoms.
Oxidizing agents for vapor deposition process include oxygen, hydrogen peroxide and ozone and reducing agents for deposition processes include hydrogen, hydrazine, monoalkylhydrazine, dialkylhydrazine, and ammonia.
One type of structure in the metal precursor is illustrated in structure 1A below where the metal M has a valence of 2 having the formula:
wherein M is selected from group 2, 8, 9, 10 metal atoms. In this precursor it is preferred that R 1 is a C 1-6 alkyl group, preferably a t-butyl or t-pentyl group when the metal is strontium and barium and C 1-6 when cobalt or nickel, R 2 and R 3 are methyl groups, R 5 and R 6 are individually lower C 1-3 , preferably methyl groups and R 4 is a C 3-10 branched alkylene bridge having at least one chiral carbon atom, preferably a group containing 3 or 4 carbon atoms. Preferred metals are calcium, strontium, barium, iron, cobalt, and nickel.
Another type of structure within the first class of metal complexes containing tridentate β-ketoiminate ligands is illustrated in structure 2A below where the metal M has a valence of 3 having the formula:
wherein M is selected from group 3 metal atoms. In this precursor it is preferred that R 1 is a C 4-6 alkyl group, preferably a t-butyl and t-pentyl group, R 2 and R 3 are methyl groups, R 5 and R 6 are individually lower C 1-3 alkyl, preferably methyl groups, and R 4 is a C 3-10 branched alkylene bridge having at least one chiral carbon atom, preferably a group containing 3 or 4 carbon atoms. Preferred metals are scandium, yttrium, and lanthanum.
The second class of metal-containing precursors are comprised of tridentate β-ketoiminate ligands as shown in formula B:
wherein M is a Group 4 or 5 metal such as titanium, zirconium, or hafnium. As shown the complex consists of at least one alkoxy ligand and a tridentate β-ketoiminato ligand having at least one amino organo imino functionality. The preferred R 1-6 groups are the same as in formula A. The preferred R 7 group is a linear or branched alkyl, e.g., iso-propyl, butyl, sec-butyl, and tert-butyl, m and n are at least 1 and the sum of m+n is equal to the valence of the metal.
The tridentateβ-ketoiminate ligands can be prepared by well known procedure such as the Claisen condensation of a bulky ketone and an ethyl ester in presence of a strong base such as sodium amide or hydride, followed by another known procedure such as Schiff base condensation reaction with alkylaminoalkylamine. The ligands can be purified via vacuum distillation for a liquid or crystallization for solid.
As a preferred method for the formation of high yield and thermal stable tridentate ligands, it is preferred to choose a bulky R 1 group, e.g., C 4-6 alkyl groups without hydrogen attached to the carbon connected to the ketone functionality, most preferred R 1 group is tert-butyl or tert-pentyl. The R 1 group prevents side reactions occurring in the following Schiff condensation and later protecting the metal centers from inter-molecular interaction. There is a competing issue and that is that the R 1-7 groups in the tridentate ligands should be as small as possible in order to decrease the molecular weight of the resulting metal-containing complexes and allow the achievement of complexes having a high vapor pressure. The preferred R 4 is a branched alkylene bridge having at least one chiral carbon atom, most preferably a group containing 3 or 4 carbon atoms in order to make the resulting complexes more stable via forming a five- or six-membered coordinating ring to the metal center. The chiral center in the ligand plays a crucible in terms of lowering down the melting point as well as increasing the thermal stability.
The metal-containing complexes can then be prepared via the reaction of the resulting tridentate ligands with pure metal, metal amide, metal hydride, and metal alkoxide. The metal-containing complexes can also be prepared via reacting the tridentate ligand with alkyl lithium or potassium hydride to provide the lithium or potassium salt of the ligand, then followed by reaction with metal halide, MX n (X═Cl, Br, I; n=2, 3). The group 4 and 5 mixed ligand complexes can be made via changing the ratio of metal alkoxide to the tridentate ligands.
These metal-containing complexes with tridentateβ-ketoiminate ligands can be employed as potential precursors to make thin metal or metal oxide films via either the chemical vapor deposition (CVD) or atomic layer deposition (ALD) method at temperatures less than 500° C. The CVD process can be carried out with or without reducing or oxidizing agents whereas an ALD process usually involves the employment of another reactant such as a reducing agent or oxidizing agent.
For multi-component metal oxide, these complexes can be premixed if they have the same tridentate β-ketoiminate ligands. These metal-containing complexes with tridentate β-ketoiminate ligands can be delivered in vapor phase into a CVD or ALD reactor via well-known bubbling or vapor draw techniques. A direct liquid delivery method can also be employed by dissolving the complexes in a suitable solvent or a solvent mixture to prepare a solution with a molar concentration from 0.001 to 2 M depending the solvent or mixed-solvents employed.
The solvent employed in solubilizing the precursor for use in a deposition process may comprise any compatible solvent or their mixture including aliphatic hydrocarbons, aromatic hydrocarbons, ethers, esters, nitrites, and alcohols. The solvent component of the solution preferably comprises a solvent selected from the group consisting of glyme solvents having from 1 to 20 ethoxy —(C 2 H 4 O)— repeat units; C 2 -C 12 alkanols, organic ethers selected from the group consisting of dialkyl ethers comprising C 1 -C 6 alkyl moieties, C 4 -C 8 cyclic ethers; C 12 -C 60 crown O 4 -O 20 ethers wherein the prefixed C i range is the number i of carbon atoms in the ether compound and the suffixed O i range is the number i of oxygen atoms in the ether compound; C 6 -C 12 aliphatic hydrocarbons; C 6 -C 18 aromatic hydrocarbons; organic esters; organic amines, polyamines and organic amides.
Another class of solvents that offers advantages is the organic amide class of the form RCONR′R″ wherein R and R′ are alkyl having from 1-10 carbon atoms and they can be connected to form a cyclic group (CH 2 ) n , wherein n is from 4-6, preferably 5, and R″ is selected from alkyl having from 1 to 4 carbon atoms and cycloalkyl. N-methyl- or N-ethyl- or N-cyclohexyl-2-pyrrolidinones, N,N-Diethylacetamide, and N,N-Diethylformamide are examples.
The following example illustrates the preparation of the metal-containing complexes with tridentate β-ketoiminate ligands as well as their use as precursors in metal-containing film deposition processes.
EXAMPLE 1
Synthesis of 2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanone
To a solution of 13.55 g (95.29 mmol) 2,2-dimethyl-3,5-hexanedione in 150 mL of THF containing with 20 g (140.81 mmol) of sodium sulfate was added 11.68 g (114.34 mmol) of 1-dimethylamino-2-propylamine. Reaction mixture was heated to 65° C. for 72 hours. After completion, THF was evaporated under vacuum and excess 1-dimethylamino-2-propylamine was distilled by heating the mixture at 80° C. under 140 mTorr vacuum for one hour. Residual oil was subjected to vacuum transfer heating at 110° C. under 100 mTorr vacuum. 18.75 g of a lime-green yellow oil was obtained and GC analysis indicates 99% purity. The yield was 87%.
1 H NMR (500 MHz, C 6 D 6 ): δ=11.51 (s, 1H), 5.20 (s, 1H), 3.24 (m, 1H), 1.91 (m, 2H), 1.91 (s, 6H), 1.60 (s, 3H), 1.32 (s, 9H), 0.94 (d, 3H).
EXAMPLE 2
Synthesis of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium
To a solution of 1 g (1.81 mmol) Sr(N(SiMe 3 ) 2 ) 2 ) .(THF) 2 in 10 mL THF was added 0.82 g (3.62 mmol) 2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanone in 10 mL of THF dropwise at room temperature. Stirred for 16 hours. THF was evaporated off under vacuum to provide an off-white solid that was taken up as a solution in hexanes. Evaporated off hexanes and dry solid was recrystallized in pentane at room temperature. 0.48 g of clear needle-like crystals were obtained (50% yield based on Sr).
Elemental analysis: calculated for C26H50N4O2Sr: C, 58.01; N, 10.40; H, 9.36. Found: C, 56.07; N, 10.10; H, 8.86. 1 H NMR (500 MHz, C 6 D 6 ): δ=5.12 (s, 1H), 3.42 (m, 1H), 3.32 (t, 1H), 1.96 (b, 2H), 1.83 (s, 6H), 1.72 (b, 2H), 1.41 (s, 9H), 0.94 (d, 3H).
A colorless crystal was structurally characterized by single crystal analysis. The structure shows strontium coordinated with two oxygen and four nitrogen atoms from the two tridentate ketominate ligands in a distorted octahedral environment. This is illustrated in FIG. 1 in which there are ethylene bridges between the two nitrogen atoms of the imino functionality for R 4 shown as C4, C5 and C18, C17. C4 and C17 are chiral atoms as they are connected to four different substituents, i.e. H, N1, C11, C5 for C4 and H, N3, C18, C24 for C17.
FIG. 2 shows a TGA of the compound of Example 2 having ethylene bridges with chiral centers between the two nitrogen atoms of the imino functionality for R 4 ; in contrast to the analogous compound where R 4 is an ethylene bridge without chiral centers. The compound of Example 2 is shown by the solid line, while the analogous compound where R 4 is an ethylene bridge is shown by the dotted line. A larger residue in a TGA analysis typifies compounds having less stability. Thus, the compound of Example 2 has less than 1% residue whereas the analogous compound without chiral centers over 14% residue, indicating a substantial enhancement in thermal stability necessary when used as a precursor to deposit metal-containing films in a deposition in semiconductor fabrication.
EXAMPLE 3
Synthesis of bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)nickel
To a solution of 3.49 g (15.43 mmol) 2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanone in 10 mL of hexanes at −78° C. in dry ice/acetone bath was added 6.17 mL (15.43 mmol) of 2.5M n-butyl lithium in hexanes dropwise. Warmed solution to room temperature and left to stir for one hour. Hexanes was evaporated from solution under vacuum and a residual sticky yellow oil was obtained. 20 mL of THF was added to the residual and this solution was added to 1.00 g (7.72 mmol) NiCl 2 in 10 mL of THF at room temperature. Stirred for 96 hours under argon heating at 60° C. Evaporated off THF under vacuum and residual dark green solid was taken up in hexanes, heated, and filtered. Evaporated hexanes under vacuum and obtained 3.5 g of a sticky dark green solid that was sublimed at 100° C. under 65 mTorr of vacuum for 48 hours yielding 2.8 g of a green solid (70% yield). Sublimed material was recrystallized by slow evaporation of pentane at room temperature.
Elemental Analysis: calculated for C26H50N4NiO2: C, 61.30; H, 9.89; N, 11.00. Found: C, 59.18; H, 9.09; N, 10.84.
A dark green crystal was structurally characterized by single crystal analysis. The structure shows nickel coordinated with two oxygen and four nitrogen atoms from the two tridentate ketominate ligands in a distorted octahedral environment. This is illustrated in FIG. 3 in which there are ethylene bridges between the two nitrogen atoms of the imino functionality for R 4 shown as C9, C11 and C22, C23. C9 and C22 are chiral atoms as they are connected to four different substituents, i.e. H, N1, C10, C11 for C9 and H, N3, C23, C24 for C22.
FIG. 4 shows a TGA of the compound of Example 3 having ethylene bridges with chiral centers between the two nitrogen atoms of the imino functionality for R 4 ; in contrast to the analogous compound where R 4 is an ethylene bridge without chiral centers. The compound of Example 3 is shown by the solid line, while the analogous compound where R 4 is an ethylene bridge without chiral centers is shown by the dotted line. A larger residue in a TGA analysis typifies compounds having less stability. Thus, the compound of Example 3 has approximately less than 3% residue whereas the analogous compound over 13% residue, indicating a substantial enhancement in thermal stability necessary when used as a precursor to deposit metal-containing films in a deposition in semiconductor fabrication.
EXAMPLE 4
Synthesis of Ti(O- i Pr) 3 (2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato
To a solution of 1 g (3.52 mmol) titanium(IV)isopropoxide in 15 mL of hexanes was added 0.80 g (3.52 mmol) 2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanone and reaction mixture was heated to 60° C. for 16 hours. Evaporated off volatiles under vacuum and obtained 1.59 g of a crude grainy oil.
1 H NMR (500 MHz, C 6 D 6 ): δ=5.32 (s, 1H), 5.10 (b, 3H), 3.20 (m, 1H), 2.40 (b, 2H), 2.40 (b, 6H), 1.64 (s, 3H), 1.39 (d, 18H), 1.36 (s, 9H), 1.27 (b, 3H).
One of the crucial requirements for precursors employed for chemical vapor deposition and atomic layer deposition is that the precursor has to be stable during the delivery temperature, generally ranging from 40 to 150° C. The thermogravimetric analysis (TGA) is widely used as a tool to screen compounds. The measurements of the compounds of the present invention were carried out in open aluminum crucibles with sample sizes of 10 to 20 mg inside a dry box. The temperature ramp rate is usually 10 C.°/min. As the temperature increases, the compound starts to undergo either vaporization or decomposition or both. Pure vaporization leads to almost no residue, whereas vaporization plus decomposition results in certain degree of residue. Generally speaking, less residue in a TGA diagram suggests the compound is more thermally stable, thus more suitable to be a precursor for fabricating thin films. As shown in FIGS. 2 and 4 , the compounds revealed in this invention have much less than residues than those prior analogues, suggesting they are more thermally stable and have a better capability to be employed as precursors. On the other hand, introduction of chiral centers is one approach to increase the thermal stability, as well as to lower the melting point of resulting metal compounds. A molecule is chiral if it cannot be superimposed on its mirror image, the two mirror images of such a molecule are referred to as enantiomers. If a carbon atom has four different substituents connected to it, it is chiral. For compounds in Example 2 and 3, there are two chiral carbon atoms, implying there are three enantiomers co-existing in the solid state, which scramble around, weakening the intermolecular interaction, thus increasing the volatility, as shown in FIG. 5 , although bis(2,2-dimethyl-5-(dimethylaminoethyl-imino)-3-hexanonato-N,O,N′)strontium is smaller than bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium, and, in theory, bis(2,2-dimethyl-5-(1-dimethylamino-2-propylimino)-3-hexanonato-N,O,N′)strontium should be less volatile than bis(2,2-dimethyl-5-(dimethylaminoethyl-imino)-3-hexanonato-N,O,N′)strontium. | Metal-containing complexes of a tridentate beta-ketoiminate, one embodiment of which is represented by the structure:
wherein M is a metal such as calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, vanadium, tungsten, manganese, cobalt, iron, nickel, ruthenium, zinc, copper, palladium, platinum, iridium, rhenium, osmium; R 1 is selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, and aryl, having 1 to 10 carbon atoms; R 2 is selected from the group consisting of hydrogen, alkyl, alkoxy, cycloaliphatic, and aryl; R 3 is linear or branched selected from the group consisting of alkylene, fluoroalkyl, cycloaliphatic, and aryl; R 4 is a branched alkylene bridge with at least one chiral center; R 5-6 are individually linear or branched selected from the group consisting of alkyl, fluoroalkyl, cycloaliphatic, aryl, and can be connected to form a ring containing carbon, oxygen, or nitrogen atoms; n is an integer equal to the valence of the metal M. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 10/276,203, filed Nov. 12, 2001, and claims a right of priority based upon PCT Application No. PCT/EP01/05157, filed May 7, 2001 and German Application No. 200 08 413.5 filed May 7, 2000, all of which are hereby incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to a detection system for sensing an object in motion relative to a container, especially tubular in design, whereby at least one magnetic unit is associated with the container and/or object, generating as well as measuring magnetic fields, and at least one evaluation device is connected to the magnetic units and serves to receive sensing signals from the magnetic units.
[0004] A detection system of this type is described in U.S. Pat. No. 3,103,976. That particular detection system is used in locating pipes, and especially pipe ends to be joined, in underwater drilling and similar operations. A guide tube, serving as a container extending between a topside derrick and a frame section anchored on the sea bottom, is equipped on its outside with a coil as the magnetic unit generating a magnetic field and with each two search coils respectively mounted above and below the first coil and serving as the magnetic-field measuring magnets. Electric cables connect these various coils with a topside evaluation unit within the derrick. The magnetic-held-generating coil produces a magnetic field inside the guide tube essentially along the longitudinal axis of the tube. That magnetic field also permeates the two magnetic-field-measuring coils. If and when within the guide tube a drill rod, tool, pipe or the like is shifted, the magnetic field in these measuring coils will change as a function of the position of the moving object, leading to a corresponding induction in these coils. It is thus possible to determine when the object concerned has reached one of these magnetic-field-measuring coils or for instance the blowout valve located on the sea bottom.
[0005] That earlier detection system, however, is essentially limited to sensing the position only of the forward end of the moving object, with the positional detection accuracy being determined by its distance from the coils which are mounted along the longitudinal axis of the guide tube, by the coil width in the longitudinal direction, and similar factors.
BRIEF SUMMARY OF THE PREFERRED EMBODIMENTS
[0006] It is the objective of this invention to provide an improved detection system of the type first above mentioned, the improvement consisting in the ability, in simple fashion and with a relatively high degree of accuracy, to determine not only the position of the object relative to the container in the longitudinal direction but also its position in the transverse direction relative to the container.
[0007] In conjunction with the characteristic features specified within the main concept of the claims, this is accomplished in that the magnetic units produce a maximum magnetic flux essentially perpendicular to the direction of relative movement between the object and the container. This causes a change in the magnetic field and in the magnetic flux when the object is close enough to the container that both are located within the magnetic field of the magnetic-field-generating magnetic unit. At the same time, given this position of the object and the container relative to each other, there will be a change in the magnetic field in the direction perpendicular to the relative movement, thus yielding for the evaluation device additional information on the position of the object and the container perpendicular to the direction of relative movement.
[0008] According to this invention, the functionality of the detection system does not depend on whether the container, for instance tubular in design, is stationary while the object moves relative to it, or vice versa, for as long as at least the moving part contains a magnetic element which triggers a corresponding change in the magnetic field between the magnetic units.
[0009] In oil-drilling or similar operations, it may be advantageous in this context if in particular the tubular container constitutes the aforementioned guide tube and the object is the part that moves relative to that tube. The latter should consist of, or contain, a magnetic material at least at the point which is to serve for the detection of the position and orientation of the object relative to the container. That point could for instance be the forward end of the object.
[0010] An object of this type typically moves within the container so that the corresponding magnetic units can be advantageously mounted in an inside area of the container. On the other hand, if the moving object consists of a non-magnetic material while the container is provided with a magnetic element in an appropriate location, the corresponding magnetic units may equally well be mounted on an outside surface of the object. It is also possible, for facilitated access, to position the magnetic units on an outside surface of the container with the generated magnetic field extending through the wall and into the interior of the container.
[0011] In one possible, simple configuration for the precise capture of the moving object the magnetic units are arranged along at least one orientational plane perpendicular to the direction of relative movement. For example, multiple magnetic units may be arranged in a circular array or in some other way depending on the cross-sectional shape of the container, with the possibility of mounting the magnetic units, with equidistant spacing from one another, in the circumferential direction of the container.
[0012] So as not to limit the detection of the object to essentially one such plane, magnetic units may be mounted perpendicular to the direction of relative movement in evenly spaced planar increments. This permits capture in each of these staggered planes as well as detection between these planes by means of suitably interconnected magnetic units.
[0013] Depending on the design of the magnetic unit, it is possible for such a magnetic unit to be switchable between magnetic-field generation and magnetic-field sensing. This can take place even during the course of a measurement. Evidently, such switchability of the magnetic units involves variable polarity of the magnetic units, variable magnetic-field intensity or the like.
[0014] A simple design example of a magnetic-field-generating magnetic unit can be implemented in the form of a permanent magnet.
[0015] For an expanded range of possibilities in object detection per the above, a magnetic unit may be constituted of an electrically powered coil which provides a simple way to permit operation both for magnetic-field generation and magnetic-field measurement. A coil also allows for easy variation of the magnetic-field intensity or polarity and the generation of alternating fields.
[0016] A magnetic-field-measuring unit that is at once precise, simple and inexpensive may be in the form of a magnetic-field sensor and in particular a Hall element. Magnetic-field sensors of that type can be installed, in simple fashion and at low cost, in arrays of the desired density and configuration for instance on the inside of the container.
[0017] Of course, a suitably designed magnetic unit can also detect magnetic attenuation instead of measuring the magnetic field or magnetic flux.
[0018] For an amplification of the magnetic field and thus of the magnetic flux perpendicular to the direction of relative movement, the magnetic unit may incorporate a magnetizable material, for instance a ferromagnetic or paramagnetic material.
[0019] To avoid having to separately provide each magnetic unit with a magnetizable material, the magnetic units may be interconnected by a magnetizable or magnetically conductive material.
[0020] For a secure installation of the magnetic unit, the unit may be placed for instance in a radial bore in the container wall. The radial bore should be at least deep enough in the radial direction for the magnetic unit to be fully insertable without protruding into the interior of the container.
[0021] To avoid having to drill a corresponding number of radial bores or similar recesses in the container wall while at the same time being able to simultaneously manipulate a larger number of magnetic units, it is possible to mount multiple magnetic units in a magnetic-detector insert which may be mounted for instance in a circumferential recess on the inside of the container. This recess can again be deep enough to prevent the magnetic-detector insert with the magnetic units from protruding into the interior of the container.
[0022] Suitably designed magnetic units allow for the deployment in objects with a variety of cross sections. Of course, for oil exploration and similar applications it will be advantageous, and at the same time the data capture for the detection of the object within the container will be simplified, if the container and/or object are essentially tubular in design. In applications related to oil and gas exploration, it is an essentially tubular object that is guided within an equally more or less tubular container. The object can be so guided that it is either in contact with or moves at a distance from the inside wall of the container.
[0023] In another possible, simple and space-saving design, a magnetic unit may be provided with a ramified and/or continuous helical, electrically conductive ribbon. Such a ribbon essentially corresponds to a coil and generates a comparable magnetic field.
[0024] For the convenient manipulation of ribbon-shaped magnetic units of this type, the ribbon may be mounted on a preferably annular insert. The insert, of course, is shaped to correspond to the cross section of the container, permitting easy installation on an inside surface of the container.
[0025] The insert can allow for further simplification in that the necessary electrical power-supply and/or signal-collecting leads are attached to the ribbon-shaped magnetic units mounted in the insert.
[0026] In analogous fashion it is possible in the case of the aforementioned magnetic-detector insert employing electrical coils to provide the electric coils with winding stems as magnetic units. The coils are wound on these winding stems which, like the entire magnetic-detector insert, may consist of a magnetizable material.
[0027] The evaluation especially of the signals received by the magnetic-field-sensing magnetic units is possible not only for determining the position of the object. A suitably equipped evaluation device may include a memory module and/or a display unit or may be connectable to the latter or for instance to a computer. Stored in the memory module may be the necessary mathematical evaluation algorithms and/or address tags permitting the analysis of the measured signals. The display unit may be used, for example, for a graphic illustration of the object or for detecting the object.
[0028] The evaluation device may also be so configured that in addition to merely detecting the presence of the object it also permits the determination of the position, shape, size or direction of movement of the object.
[0029] The analysis of the signals emanating from the magnetic units and the very positioning of the magnetic units can be simplified for instance by aligning the magnetic axes of the magnetic units with a longitudinal axis of symmetry of the container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The following describes desirable design examples of this invention in more detail with the aid of the figures in the attached drawings in which:
[0031] [0031]FIG. 1 is a perspective side view of a first design example of a detection system according to this invention, employing a tubular container;
[0032] [0032]FIG. 2 is a top view of a horizontal section through FIG. 1;
[0033] [0033]FIG. 3 is a perspective side view of a second design example of a detection system according to this invention;
[0034] [0034]FIG. 4 shows a partial vertical section through FIG. 3;
[0035] [0035]FIG. 5 is a perspective side view of a third design example of a detection system according to this invention;
[0036] [0036]FIG. 6 is an enlarged illustration of detail “A” in FIG. 5;
[0037] [0037]FIG. 7 is an enlarged illustration of detail “B” in FIG. 5;
[0038] [0038]FIG. 8 is a conceptual illustration of a horizontal cross section through a detection system according to this invention;
[0039] [0039]FIG. 9 is an illustration as in FIG. 8 with an object in central position;
[0040] [0040]FIG. 10 is an illustration as in FIG. 8 with an object in an off-center position;
[0041] [0041]FIG. 11 is an illustration as in FIG. 8 with an object in another off-center position;
[0042] [0042]FIG. 12 is an illustration as in FIG. 8 with an object in another central position;
[0043] [0043]FIG. 13 is a conceptual illustration explaining the magnetic flux; and
[0044] [0044]FIG. 14 shows in detail an area-array element per FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] [0045]FIG. 1 depicts a first design example of a detection system 1 according to this invention, with a tubular container 2 and a similarly tubular object 3 . The container extends for instance from an ocean-surface platform, not shown, to a frame section anchored on the sea floor. Inside the container 2 the object 3 is guided in the longitudinal direction 33 i.e. in the direction of relative movement 14 . The object may for instance be a section of a drill rod, a tool or similar implement employed in submarine oil exploration.
[0046] In an orientational plane 16 which extends perpendicular to the direction of relative movement 14 , the container 2 accommodates a number of magnetic units 4 to 9 . These are housed in corresponding radial bores of the container 2 and support at least one electric coil 17 each. The central axes of the coils 17 are positioned in the orientational plane 16 and point toward the center of the longitudinal bore 36 . All magnetic units 4 to 9 are mounted in an equidistant relation to one another on the inside 15 along the internal circumference of the container 2 . The coils 17 are positioned within the radial bore 19 so that the magnetic units 5 to 9 will not protrude past the inner surface 15 into the longitudinal bore 36 .
[0047] Each coil 17 connects to the appropriate electrical leads 35 which extend away from the container 2 from where they are bundled in omnibus cables, not shown, and run for instance to a topside point.
[0048] At least magnetic unit 4 is a magnetic-field-generating magnetic unit. Its magnetic field is modified by the object 3 which at least in part consists of a magnetizable or magnetically conductive material 18 , and the magnetic field, modified by the movement and changed position of the object 3 relative to the longitudinal bore 36 , can be captured by the magnetic-field-sensing magnetic units 5 to 9 . By way of their electrical leads 35 , the magnetic units 5 to 9 thus generate a corresponding induced voltage as a function of the magnetic flux permeating them and changing with time.
[0049] Instead of arranging the magnetic-field-generating magnetic unit 4 and the corresponding magnetic-field-sensing magnetic units 5 to 9 in one single plane 16 per FIG. 1, it is also possible to position the magnetic-field-sensing magnetic units for instance partly or entirely in different orientational planes which are spaced at a distance from and offset upward and/or downward relative to the orientational plane 16 per FIG. 1.
[0050] [0050]FIG. 2 shows a horizontal section through FIG. 1 in the area of the orientational plane 16 and more specifically in the area where magnetic unit 7 is located. The radial bore 19 in a wall 37 of the container 2 opens toward the inside surface 15 while at its opposite end a wire duct 38 allows the electrical leads 35 to run from the coil 17 to the outside and away from the longitudinal bore 36 . The wire duct 38 can be closed off with a cap 39 through which the leads 35 are passed via a water-tight seal.
[0051] The magnetic-field-generating magnetic unit 4 per FIG. 1 is configured in analogous fashion. It should be mentioned at this point that all magnetic units per FIG. 1 are capable of serving as magnetic-field-generating or magnetic-field-sensing magnetic units. For example, magnetic units 6 , 7 and 8 may be used as the magnetic-field-sensing units and the magnetic units 4 , 5 and 9 as the magnetic-field-generating units. Obviously, any arbitrary assignment of these magnetic units is possible both before and during a given detection process.
[0052] [0052]FIG. 3 is a perspective view, corresponding to FIG. 1, of a second design example of the detection system 1 according to this invention. In this figure and in the figures that follow as well as in FIGS. 1 and 2, identical components bear identical reference numbers which will be mentioned only occasionally.
[0053] [0053]FIG. 3 differs from FIG. 1 by the consolidation of the magnetic units 4 to 10 in one magnetic detection insert 20 consisting of a magnetizable or magnetically conductive material 18 . The magnetic detection insert 20 is suitably mounted in a circumferential recess 21 on the inside 15 of the wall 37 of the container 2 . The magnetic detection insert 20 has an essentially U-shaped cross section. The open end of the U-profile faces inward in the direction of the longitudinal bore 36 . Located at given points in the annular gap 40 between the legs of the U-profile is a winding stem 28 consisting of a magnetizable material and radially extending parallel with the U-legs toward the inside in the direction of the longitudinal bore 36 . Wound onto each such winding stem 28 is a coil 17 of the respective magnetic unit 4 to 10 . These magnetic units, i.e. coils, are arranged in one orientational plane 16 analogous to FIG. 1. It should be pointed out again that similar magnetic detection inserts can be mounted in more than one orientational plane.
[0054] [0054]FIG. 4 shows a partial vertical section through the design example per FIG. 3. It clearly illustrates that the coil 17 is wound on the winding stem 28 and that the associated electrical leads 35 of the coil 17 run through a hole in the wall 37 to the outside in a radial direction relative to the container 2 . As has been explained in connection with FIG. 1, the various magnetic units 4 to 10 may be optionally set to operate as magnetic-field-generating or magnetic-field-sensing units.
[0055] [0055]FIG. 5 is a perspective view, analogous to FIGS. 1 and 3, of a third design example of the detection system according to this invention.
[0056] In this design example, the magnetic units 4 to 11 are in the form of ribbons 22 applied on an insert 23 by a thin-film or similar technology process. The ribbons extend in a ramified and/or helical configuration. Each ribbon is provided at one end with an electrical connector 41 and at the other end with a corresponding electrical connector 42 for supplying power or collecting sensing signals. On the outside of the insert 23 opposite the longitudinal bore 36 the contacts 41 , 42 are connected, for instance as shown in FIG. 6, to electrical power supply lines 24 , 25 or electrical signal-processing lines 26 , 27 . These electrical lines 24 , 25 and 26 , 27 , for instance as shown in FIG. 7, can be switched to serve either as power-supply or signal-processing lines, thus affording the option of using the magnetic units.
[0057] The insert 23 consists of a thin ring of a magnetizable material which allows easy mounting on the inside wall 15 of the container 2 in essentially any desired location. Similar inserts 23 can be mounted in different orientational planes as described in connection with FIGS. 1 and 3.
[0058] At one point the insert 23 , by way of its leads 24 to 27 , is connected to an evaluation device 12 which in the case of submarine oil exploration is typically located in a suitable place on a surface platform. For other applications of the detection system according to this invention, such as land-based oil exploration, the evaluation device 12 will be set up in a conveniently accessible location.
[0059] In the design example per FIG. 5, the evaluation device 12 incorporates for instance a memory module 29 for saving the incoming sensing signals or for storing appropriate programs for the analysis of these sensing signals. The sensing signals, processed as necessary, can be viewed on a display monitor 30 connected to the evaluation device 12 . The evaluation device 12 may be computerized or connected to a remote computer 31 which may also allow the evaluation device to be programmed for instance to switch the magnetic units into the magnetic-field-generating or, respectively, magnetic-field-sensing mode.
[0060] At this juncture it should be mentioned that the magnetic-field-generating magnetic units may also be in the form of permanent magnets, for one example. The magnetic-field-sensing magnetic units on their part may be in the form of magnetic sensors such as Hall elements.
[0061] The evaluation device 12 also offers the possibility to change the polarity or field intensity of the magnetic field generated. Alternating magnetic fields can also be produced.
[0062] FIGS. 8 to 12 are conceptual illustrations of the detection system 1 according to this invention, showing different magnetic units 4 to 11 without an object 3 (FIG. 8) and, respectively, with different objects in different positions within the container 2 .
[0063] [0063]FIG. 8 shows the magnetic field generated by the magnetic unit 4 , unaffected, as in FIG. 1, by any object 3 . The corresponding magnetic-field flux lines 43 extend perpendicular to the longitudinal bore 36 and flow to the respective magnetic-field-sensing magnetic units 5 to 11 . The distance of the magnetic-field-sensing magnetic units 5 to 11 from the magnetic-field-generating magnetic unit 4 determines the extent to which the flux lines permeate the magnetic units. The magnetic flux itself varies accordingly.
[0064] The magnetic units 4 to 11 are arranged in a way that they, and in particular their respective magnetic axes 32 as shown for instance in FIG. 9, are oriented toward a central point 34 in the longitudinal bore 36 , i.e. toward an axis of symmetry 34 which extends in the longitudinal direction 33 per FIG. 1.
[0065] When an object 3 moves relative to the container 2 , the result will be a change in the path of the magnetic flux lines, as shown in FIGS. 9 to 11 . In FIG. 9 the object 3 is positioned at dead center 34 , causing a correspondingly symmetrical flux-line distribution pattern. In FIG. 10, the object is situated off-center and close to the magnetic-field-generating magnetic unit 4 .
[0066] In FIG. 11, the object 3 is again in an off-center position, in this case close to the magnetic-field-sensing magnetic unit 9 .
[0067] From the respective changes in the magnetic fields and the magnetic flux, detectable by the magnetic-field or magnetic-flux-sensing units 5 to 11 , conclusions can be drawn as to the presence of the object 3 in the vicinity of the magnetic unit as well as the distance between the object 3 and the individual magnetic units, the orientation and dimensions of the object 3 and its direction of movement. By means of appropriate imaging processes in the evaluation device 12 , for instance as shown in FIG. 5, it is possible to view on the display monitor 30 the object 3 , its position, orientation, size and movement.
[0068] [0068]FIG. 12 shows an object 3 larger in overall dimensions and wall thickness, with corresponding changes in the magnetic field and magnetic flux pattern. FIG. 12 thus shows what other conclusions are possible in terms of the dimensions of the object 3 .
[0069] [0069]FIG. 13 is a simplified representation of a magnetic-field-generating magnetic unit 4 , the magnetic field and flux line 43 generated by it, and the respective magnetic flux 13 through different area-array elements 44 . Traditionally, the magnetic flux is determined by the following equation:
φ = ∫ Δ Bx A
[0070] where
[0071] φ is the magnetic flux, B is the magnetic induction and dA is an infinitesimal vectorial area-array element. According to the invention, the magnetic units 4 to 11 are so arranged that the respective magnetic flux displays its maximum value perpendicular to the relative movement between the object and the container, meaning that the scalar product derived from magnetic induction and the vectorial area-array element takes on its maximum value for the respective area-array elements per FIG. 13.
[0072] [0072]FIG. 14 is a conceptual illustration showing that for each area-array element 44 the magnetic flux derives from the scalar product of magnetic induction B und ΔA as the vectorial area-array element. The applicable equation is a follows:
φ=|β x|ΔA|x cos α
[0073] where
[0074] α is the corresponding angle 46 between the vectors B and ΔA.
[0075] The following will briefly explain the operating mode of the detection system according to this invention with reference to the attached drawings.
[0076] By way of the magnetic flux and/or the magnetic attenuation, the detection system according to this invention measures any given object of any given shape, orientation, position and geometry within a magnetic field generated inside a container 2 . One or several magnetic units serve to generate the magnetic field and the corresponding magnetic flux. One or several additional magnetic units capture the magnetic flux that has been modified by the object and its movement or location and on the basis of the sensing signals received it is possible to determine the distance between the object and these magnetic units as well as the position, size and direction of movement of the object. The magnetic-flux-based measurement can take place in static and/or dynamic fashion through alternating fields, variable field intensity and variable polarity.
[0077] The magnetic-field-generating magnetic units may be in the-form for instance of a permanent magnet or electrically powered and controlled coil. The magnetic-field-sensing magnetic units can measure the magnetic flux produced in static fashion employing Hall elements and/or in dynamic fashion by way of electromagnetic induction. The configuration and the number of the magnetic-field-generating and magnetic-field-sensing magnetic units are variable, and especially when coils are used as the magnetic units a switchover between the magnetic-field-generating and the magnetic-field-sensing mode of the magnetic units is easily accomplished.
[0078] The sensing signals are evaluated using mathematical operations and/or address tags and it is possible to display them in graphic form on a display monitor per FIG. 5, showing the shape and position of the object under analysis.
[0079] The magnetic units can be arranged in a circular or other configuration in one or several planes and they are typically interconnected via a magnetically conductive or magnetizable material. The multiplicity of the different magnetic units and their utilization for generating or sensing and measuring magnetic fields produce magnetic flux patterns between all associated magnetic units which patterns, and any changes thereof, are used for the imaging and positional determination of the object to be measured. The varying magnetic flux is analyzed by appropriate metrics for a determination of the size, shape and position of drill pipes including their tool joints and any associated tools. It is also possible to detect the direction when the pipes or tools constituting the objects within the tubular container are moved. The magnetic units can further recognize drill pipes which are in contact with one of the inside walls of the container, causing the dreaded friction-induced wash-out of the equipment. | The invention relates to a measuring device for detecting a body moving in relation to an, in particular, tubular container. Said device comprises at least one magnet unit which generates a magnetic field, measures this magnetic field and which is assigned to the container and/or to the magnetic body. The device also comprises at least one evaluation device connected to the magnet units and provided for receiving measurement signals of the magnet units. The aim of the invention is to improve a measuring device of this type in order to be able to easily determine, in addition to the position of the body in relation to the container in a longitudinal direction, the position of the body in relation to the container in the transverse direction with a relatively high level of accuracy. To this end, the magnet units comprise a maximum magnetic flux that is essentially perpendicular to the direction of the relative motion of the body and container. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of U.S. application Ser. No. 10/885,072, filed Jul. 7, 2004, which is a continuation application of U.S. application Ser. No. 10/437,912, filed May 15, 2003, which is a continuation of U.S. application Ser. No. 10/067,817, filed Feb. 8, 2002, now U.S. Pat. No. 6,580,685, which is a continuation of U.S. application Ser. No. 09/809,048, filed Mar. 16, 2001, now U.S. Pat. No. 6,392,985, which is copending with U.S. application Ser. No. 09/808,993, filed Mar. 16, 2001, now U.S. Pat. No. 6,370,106, which are continuations of U.S. application Ser. No. 09/514,284, filed Feb. 28, 2000, now U.S. Pat. No. 6,262,968, which is a continuation of U.S. application Ser. No. 09/181,677, filed Oct. 29, 1998, now U.S. Pat. No. 6,064,644, which is a continuation of U.S. application Ser. No. 08/958,867, filed Oct. 27, 1997, now U.S. Pat. No. 5,898,663, which is a continuation application of U.S. application Ser. No. 08/733,924, filed Oct. 18, 1996, now U.S. Pat. No. 5,982,738, which is a continuation-in-part application of U.S. application Ser. No. 08/600,730, filed Feb. 13, 1996, now U.S. Pat. No. 5,805,565, the subject matter of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an optical recording medium and more particularly to a high-density optical recording medium having a track width smaller than an optical spot diameter.
[0003] An example of a medium for performing high-density (narrow track) recording is disclosed in, for example, JP-A-6-176404. According to this example, in an optical recording medium having grooves and lands which are formed on a substrate and information recording areas which are formed in association with both the groove and the land, prepits are disposed on a virtual extension line of the boundary between a groove and a land. In particular, the prepits are located on only one side of any specific position of the center line of each groove.
[0004] With this construction, recording information is formed on both the groove and the land, the prepits have charge of address data representative of the recording areas and one prepit is used in common to a pair of adjacent groove and land to provide address data therefor. When the technique as above is applied to, for example, a phase change recording medium or a magneto-optical recording medium, interference of information (crosstalk) between adjacent lands or grooves due to the optical interference effect within an optical spot can be prevented, thereby permitting narrowing of track.
[0005] On the other hand, in the prepit area free from the optical interference effect, the address data can be common to the paired groove and land and the effective track pitch can be increased to reduce crosstalk.
[0006] In the example of JP-A-6-176404, however, the disposition of the prepit area is offset on one side of the center line of the groove or land, so that when an optical spot is caused to track a groove or a land, a tracking error (tracking offset) increases, making it difficult to perform high-density recording in which the track pitch is narrowed.
SUMMARY OF THE INVENTION
[0007] The present invention achieves elimination of the above problems and it is a first object of the present invention to provide an optical recording medium which can suppress the tracking offset to a value or level which is sufficiently low for the practical use and permit efficient disposition of address data even when recording is effected on both the groove and the land.
[0008] A second object of the present invention is to provide a high-density optical recording medium which can ensure simple mastering and easy replica preparation and can permit decoding even when a readout error takes place.
[0009] To accomplish the above first object, the following expedients are employed.
[0010] (1) Grooves and lands are formed on a substrate of a recording medium, information recording areas are formed in association with both the groove and the land, and prepits are disposed on a virtual extension line of the boundary between a groove and a land.
[0011] The disposition of prepits satisfies the following requirements (a) to (c) at the same time.
(a) Prepits are located on both sides of a virtual extension of the center line of a groove; (b) Prepits are located on both sides of a virtual extension of the center line of a land; (c) Prepits are not located on the both sides of any specific position of the center line of a groove; and (d) Prepits are not located on the both sides of any specific position of a land.
[0016] With this construction, the arrangement of prepits is not offset on either one side of a virtual extension of the center line of the groove or the land to ensure that tracking offset hardly occurs and the prepits do not exist on both sides of any specific position of the center line of the groove or the land to prevent interference of prepit information between adjacent tracks from taking place within a reproduced spot so as to permit high-density narrow track recording.
[0017] (2) When prepits are disposed in the circumferential direction such that those on one side of a groove are not discriminative from those on the other side or those on one side of a land are not discriminative from those on the other side, at least consecutive two dispositions of prepits associated with the groove or the land are made to be different from each other to provide the same disposition of prepits periodically every two dispositions.
[0018] As the other option,
[0019] (3) A groove associated with at least one pair of pits disposed on both sides of the center line of the groove in a prepit area and an adjacent groove not associated with pits disposed on both sides of the center line of this groove within the prepit area are disposed alternately in the radial direction.
[0020] Through this, by merely reproducing the pits, prepits associated with the groove can be discriminated from those associated with the land to improve reliability of information recording reproduction.
[0021] (4) Either one of synchronous information and address data is represented by prepits disposed on either one of the both sides of a groove.
[0022] As the other option,
[0023] (5) Only one of synchronous information and address data is represented by prepits arranged on one side of a groove and both the synchronous information and the address data are represented by prepits arranged on the other of the both side of the groove.
[0024] Through this, address data can be reproduced under accurate synchronization. In addition, since the phase margin between prepits on the both sides can be extended, fabrication of a recording medium can be facilitated.
[0025] (6) The groove and the prepit have the same depth which is 70 nm or less. More preferably, the depth is 40 nm or more and 60 nm or less.
[0026] With this construction, an advantage of suitable crosstalk cancellation can be obtained between the groove and the land and besides an excellent tracking servo signal can be obtained. Formation and fabrication of the recording medium can be facilitated. With the groove depth exceeding 70 nm, the formation of the groove is difficult to achieve. When the groove depth is about 50 nm, the tracking servo is maximized and with the groove depth being about 50±10 nm, substantially the same effect can be attained.
[0027] (7) The groove and the land have substantially the same width which is between 0.3 μm and 0.75 μm.
[0028] With this construction, excellent tracking is compatible with high-density recording. If the groove and land have a width of not greater than 0.3 μm, then two of the groove and land will be confined within one optical spot and an excellent tracking signal cannot be obtained. On the other hand, if the groove and land have a width exceeding 0.75 μm, then effective high-density recording cannot be permitted.
[0029] (8) Of prepits, the smallest one has a diameter which is smaller than a width of each of the groove and the land. More preferably, the diameter is in the range from 0.25 μm to 0.55 μm.
[0030] Through this, an excellent prepit signal can be obtained without crosstalk. With the diameter being not greater than 0.25 μm, the prepit signal decreases in the extreme and with the diameter exceeding 0.55 μm, crosstalk is generated.
[0031] In the present invention, prepits are arranged on the both sides of a virtual extension line of the center line of a groove or a land in the optical spot scanning direction. Consequently, offset is decreased to make the tracking offset hardly occur and the prepits do not exist on the both sides of any specific position of the center line of the groove or the land to ensure that interference of prepit information between adjacent tracks within a reproduced spot can be prevented, and high-density narrow track recording can be permitted.
[0032] Further, even in the presence of tracking offset, the amount of tracking offset can be detected accurately by comparing amplitudes of signals representative of prepits on the both sides. Accordingly, by feedback-controlling the information indicative of a comparison result to a scanning unit, the tracking offset can be suppressed.
[0033] At a portion between a groove and a prepit area, between a land and a prepit area or between prepit areas, a gap takes place when a prepit train on a virtual extension line of the boundary between a groove and a land shifts to a prepit train on an adjacent virtual extension line. The aforementioned JP-A-6-176404, however, does not take the gap into consideration. Accordingly, in the absence of the gap or with the gap being very short, mastering of the substrate cannot be proceeded with by one-beam cutting and requires two-beam cutting. Further, during replica preparation, injection must be applied to a steep pattern, leading to a decrease in yield. In addition, during reproduction of signals, tolerance to distortion of the reproduced spot and the tracking offset is decreased and a readout error is liable to occur.
[0034] To accomplish the second object, the following expedients are employed.
[0035] (1) Grooves and lands are formed on a substrate and prepits are arranged on a virtual extension of the boundary between a groove and a land. In particular, the prepits are disposed on both sides of an extension of the center line of a groove or a land and therefore, the optical axis of a laser beam must be moved during cutting. An acoustic-optical deflector (AOD) is used to change the optical axis. But it takes a time for the AOD to cause the optical axis to reach a desired optical axis position after transmitting a signal for optical axis change and when a modulated laser beam is irradiated along the intact optical axis, pits are formed obliquely on the substrate. Accordingly, no pattern is formatted between the groove or the land and the succeeding prepits to provide a gap and an acoustic-optical modulator (AOM) is cut off corresponding to the gap to prevent laser irradiation and pit drawing. Thus, the substrate can be fabricated with a simple cutting machine. In addition, since a number of unevennesses are not formed on a narrow area on the substrate, the yield during preparation of replica can be increased.
[0036] (2) In the disposition in which prepits are arranged on a virtual extension of the boundary between a groove and a land, when the disposition of a prepit train on one side of a virtual extension of the boundary between the groove and the land is exchanged with the disposition of a prepit train on the other side or vice versa, the trailing edges of prepit trains on the respective one sides are aligned with each other in the radial direction of the substrate. The succeeding pit strains are spaced from those trailing edge positions in the circumferential direction or the recording/reproducing direction and the trailing edges of the succeeding pit trains are aligned with each other similarly. When the formed gap meets the recording rule, the substrate as a whole can be formatted conveniently and portions devoid of pits can be collected at a specified area on the substrate, thereby solving problems involved in cutting and replica preparation for reasons described previously.
[0037] (3) Radially adjacent pit trains each having only original information pits cannot be aligned with each other at the trailing edge in the radial direction. Accordingly, new pits are added to ensure the alignment of the trailing edges in the radial direction while observing the rule during recording.
[0038] (4) In the shift of the disposition of a pit train from one side to the other as described in the above (2), leading edges of pits in the disposition on the other side can be aligned in the radial direction to solve the problems involved in cutting and replica preparation for the same reasons set forth in the (2). In particular, from the standpoint of signal reproduction, a synchronous signal is allotted to pit information immediately after the shift of the pit train so that decision of a channel bit at the specified position may be thought much of, thereby ensuring that the tolerance to the leading edge position can be increased and a possibility that erroneous reading of important data of, for example, address at the position immediately before the shift of a pit train can be decreased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is an enlarged fragmentary plan view of a first embodiment of an optical recording medium according to the present invention.
[0040] FIG. 2 is a waveform diagram of reproduced signals from the medium of FIG. 1 .
[0041] FIG. 3 is a block diagram of an apparatus for recording and reproduction of the optical recording medium used in the present invention.
[0042] FIG. 4 is an enlarged fragmentary plan view of a second embodiment of the optical recording medium according to the present invention.
[0043] FIG. 5 is an enlarged fragmentary plan view of a third embodiment of the optical recording medium according to the present invention.
[0044] FIG. 6 is a similar view of a fourth embodiment of the optical recording medium according to the present invention.
[0045] FIG. 7 is a waveform diagram of reproduced signals from the optical recording medium of FIG. 6 .
[0046] FIG. 8 is an enlarged fragmentary plan view of a fifth embodiment of the optical recording medium according to the present invention.
[0047] FIG. 9 is a diagram showing an information structure in the fifth embodiment of the optical recording medium according to the present invention.
[0048] FIG. 10 is an enlarged fragmentary perspective view showing the relation between the prepit area and the groove in the fifth embodiment.
[0049] FIG. 11 is an enlarged fragmentary plan view showing details of positional displacement in the embodiments of the optical recording medium according to the present invention.
[0050] FIG. 12 is an enlarged fragmentary plan view of a sixth embodiment of the optical recording medium according to the present invention.
[0051] FIG. 13 is a diagram showing an example of a modulated code in the sixth embodiment of the optical recording medium according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1 (Optical Recording Medium)
[0052] Referring now to FIG. 1 , there is illustrated, in enlarged fragmentary plan view form, an optical recording medium of the present invention. Grooves 84 each having a width of 0.6 μm and a depth of 50 nm and lands 85 each having a width of 0.6 μm are arranged alternately in the radial direction of the medium and recorded marks 81 are formed on the two kinds of areas. In other words, each of the groove 84 and land 85 serves as a recording area. In a prepit area 83 , any groove is not formed but pits 82 are disposed on an extension of the boundary between a land and a groove. Each of the pits has a width of 0.35 μm and a depth of 50 nm. The prepit area is divided into a first prepit area 831 and a second prepit area 832 . In the first prepit region 831 , pits 82 are disposed on the upper side, as viewed in the drawing, of the center line of the land 85 and in the second prepit area 832 , pits 82 are disposed on the lower side, as viewed in the drawing, of the center line of the land 85 . Accordingly, when an optical spot 21 scans, for example, the land 85 , pits on only either one of the sides are always reproduced and there is no fear that crosstalk will occur between adjacent tracks. Therefore, address data recorded in the form of the prepits can duly be reproduced without crosstalk.
[0053] Since the pits 82 do not adjoin to each other in the radial direction, they can be formed with ease. Also, pits 82 are uniformly disposed on both sides of a track (a land or a groove) and hence the influence on a tracking servo signal, which is caused by the pits 82 , can be canceled. Accordingly, the tracking offset can be suppressed to a sufficiently small level.
[0054] Further, when reproducing, for example, a land 85 , reproduction of address data at the second prepit area 832 is carried out continuously with reproduction of address data at the first prepit area 831 . Accordingly, when the two areas are united into one area in which information is arranged to provide address data for one track, an address (track number) of a land and that of a groove can be set independently of each other. In other words, by sequentially reproducing the address data pieces in the first and second prepit areas 831 and 832 , discrimination between the land and the groove can be ensured.
[0055] More particularly, for reproduction of the groove, address data represented by prepits arranged in the first prepit area is made to be identical to that represented by prepits arranged in the second prepit area but for reproduction of the land, address data represented by prepits in the first prepit area is made to be different from that represented by prepits in the second area. When addresses represented by prepits in the first and second prepit areas are different from each other, a correlation may be set up between the two addresses and the efficiency of error correction code can be increased by utilizing the correlation.
[0056] Preferably, synchronous information (VFO) 86 and address data 87 may both be arranged in each of the first and second prepit areas.
[0057] While in this example the prepit area is divided into two of the first and second prepit areas, the number of division which is plural may suffice. For example, when the number of division is four, pits in first and third prepit areas may be arranged on one side of a groove and pits in the second and fourth prepit areas may be arranged on the other side of the groove. By increasing the number of division of the prepit area, reliability against, for example, defects can be improved.
[0058] Here, a phase change recording material (GeSbTe) is used for the recording film. Accordingly, the recorded mark is formed in the form of an amorphous domain.
[0059] Referring now to FIG. 3 , there is illustrated an example of a configuration in which the optical recording medium of the present invention is applied to an optical recording/reproducing apparatus. In the apparatus, a semiconductor laser 311 having a wavelength of 680 nm and a collimating lens 312 are used as a light source 31 . A beam profile former such as a prism may also be provided as necessary. Power of the semiconductor laser is controlled by a light power controller 71 having the auto-light-power-control function. A light beam 22 emitted from the light source 31 is focused on a magneto-optical recording medium 8 by means of a focusing optics 32 . The focusing optics 32 has at least one lens 321 and in this example, it also has a beam splitter 324 . An objective lens 321 for focusing the light beam on the optical recording medium 8 is designed to have a numerical aperture of 0.6. Therefore, an optical spot 21 on the optical recording medium 8 has a diameter of 1.0 μm. The optical spot can be moved to a desired position on the optical recording medium 8 by means of a scanning unit 6 . The scanning unit 6 includes at least a motor 62 for rotating the disc-like magneto-optical recording medium 8 and an auto-position controller 61 having the function of auto-focus control and auto-tracking. The auto-position controller 61 utilizes a reflected beam 23 from the magneto-optical recording medium 8 to cause a photodetection unit 33 to detect an optical spot position which is used for feedback control.
[0060] The optical spot position can be detected by detecting power of a diffracted light ray from a groove. The photodetection unit 33 is constructed of a lens, a beam splitter and a plurality of photodetectors, and output signals of the plurality of photodetectors are calculated to produce a servo signal and a reproduced signal.
[0061] With the optical recording medium as shown in FIG. 1 used, signals as designated at 14 in FIG. 2 are produced as prepit signals. The signal is inputted to an address detection unit to decode address data and at the same time, timings of signals of the first and second prepit areas are detected and on the basis of the timing information, the amplitude (averaged peak-to-peak amplitude) of the first prepit area and that of the second prepit area are stored. The thus stored amplitudes are compared with each other by means of an amplitude comparator to produce tracking offset information which in turn is fed back to the position moving unit (scanning unit). Referring to FIG. 2 , when the optical spot scans a groove, a magneto-optical reproduction signal 11 and a corresponding prepit signal 14 (an upper one in the drawing) are produced and when the optical spot scans a land, a magneto-optical reproduction signal 12 and a corresponding prepit signal 14 (a lower one in the drawing) are produced. Since in this example the optical spot is slightly offset as shown in FIG. 1 , an amplitude difference 13 takes place between a prepit signal from the first prepit area 831 and a prepit signal from the second prepit area 832 . This amplitude difference corresponds to a tracking offset amount.
[0062] By using the apparatus of FIG. 3 , the tracking offset could be reduced to 0.03 μm or less even when various kinds of external disturbance such as aberration of the optical spot are taken into consideration. Under the nominal state devoid of optical aberration, the tracking offset was ±0.015 μm or less.
[0063] As described above, in the present invention, prepits are disposed on both sides of a virtual extension of the center line of a groove or a land as shown in FIG. 1 . Consequently, offset is reduced to make tracking offset hardly occur. Since prepits do not exist on both sides of any specific position of the center line of a groove or a land, interference of prepit information between adjacent tracks does not take place within a reproduced spot and hence high-density narrow track recording can be ensured.
[0064] Further, if a tracking-offset occurs as shown in FIG. 2 , the tracking offset amount can be detected accurately by comparing amplitudes of signals of prepits located on both sides. Accordingly, by feedback-controlling the information indicative of a comparison result to the scanning unit, the tracking offset can be suppressed.
[0065] Furthermore, discrimination between the groove and the land can be effected with ease.
[0066] By using the optical recording medium of the present invention, the tracking offset can be suppressed to a practically sufficiently small level (0.03 μm or less) and besides, address data can easily be obtained even during high-density narrow track recording. Through the use of the optical recording/reproducing apparatus of the present invention, the tracking offset can readily be reduced by feedback control.
Embodiment 2
[0067] Referring now to FIG. 4 , there is illustrated a second embodiment of the present invention. A medium of the present embodiment differs from that of embodiment 1 in that only synchronous information pits 861 to 864 are disposed on the upper side (as viewed in the drawing) of the center line of a groove 841 , 842 , 843 , 844 or 845 and synchronous information pits 861 to 864 and address data pits 871 to 874 are both disposed on the lower side (as viewed in the drawing) of the center line of each of the grooves 84 . Preferably, the address data pits 871 to 874 are arranged continuously to the synchronous information pits 861 to 864 . For a land 85 , the upper and lower side relation is inverted.
[0068] Being different from the embodiment 1, the present embodiment has address data arranged on only the upper or lower side of the center line of the groove or the land and therefore the same address data is allotted to the land and groove. In the present embodiment, four divisional prepits areas 831 to 834 are provided with the aim of improving the reliability of the prepit area but the prepit area is not always divided. In the present embodiment, the synchronous pit 861 in the first prepit area 831 are designed to have a longer length than the synchronous pits in the second to fourth prepit areas by taking into account the influence of aliasing of a signal which has passed through a low pass filter. Preferably, pits disposed on the upper and lower sides are spaced apart from each other by 0.5 μm or more from the view-point of fabrication of the medium. More preferably, they are spaced apart by a distance of about 1 μm which is the diameter of the reproduced optical disc spot.
Embodiment 3
[0069] Referring to FIG. 5 , there is illustrated a third embodiment in which identification marks 88 are used to discriminate the land from the groove. In the present embodiment, identification marks 88 for discrimination between the land and the groove are provided independently of the prepit area in the embodiments 1 and 2.
[0070] In the present embodiment, a pair of pits (identification marks) 88 are arranged on the upper and lower (as viewed in the drawing) sides of the center line of a groove 841 , 843 or 845 but they are not provided for a groove 842 or 844 . On the assumption that an optical spot relatively moves from left to right as viewed in the drawing when the medium provided with the above identification marks is reproduced to provide a case of “presence” where the identification marks are seen by the optical spot and a case of “absence” where the identification marks are not seen, “presence, presence” is held for the groove 841 , “absence, presence” is held for a land 851 , “absence, absence” is held for the groove 842 and “presence, absence” is held for a land 852 . Further, “presence, presence” is held for the groove 843 , “absence, presence” is held for a land 853 , “absence, absence” is held for the groove 844 and “presence, absence” is held for a land 854 . Namely, either one of “presence, presence” and “absence, absence” is held for the groove and either one of “absence, presence” and “presence, absence” is held for the land. Accordingly, this can be utilized to effect discrimination between the land and groove on the basis of a reproduced signal. To secure reliability, a plurality of pairs of identification marks may preferably be provided and more preferably, the paired pits are spaced apart from each other by several μm or more in the circumferential direction or information track direction of the medium which is perpendicular to the radial direction. For example, the prepit area in the foregoing embodiments and the identification mark area may preferably be arranged alternately in the circumferential direction.
Embodiment 4
[0071] Referring to FIG. 6 , there is illustrated, in enlarged fragmentary plan view form, an optical recording medium according to a fourth embodiment of the present invention. Grooves 84 each having a width of 0.5 μm and a depth of 40 nm and lands 85 each having a width of 0.5 μm are arranged alternately and recorded marks 81 are formed on the two kinds of areas. In other words, each of the land 85 and groove 84 serves as a recording area. In a prepit region 83 , any groove is not formed but substantially circular pits 82 (each having a diameter of 0.3 μm and a depth of 40 nm) are disposed on an extension of the boundary between a land and a groove. The prepit area is divided into a VFO (variable frequency oscillator) area 833 and an address area 834 . Especially, in the VFO area, pits 82 are disposed alternately on the upper and lower sides of the center line of a land 85 . In the address area, pits 82 are disposed alternately at the same period as that in the VFO area. Accordingly, there are no pits which exist on both sides of a position of the center line of the land or the groove.
[0072] In addition, in the address area, data for a particular track is so encoded as to differ by one pit from data for an adjacent track. In other words, the data takes the form of a Gray code. With this construction, when an optical spot 21 scans, for example, a land 85 , only pits on either one side are always reproduced and there is no fear that crosstalk will occur between the adjacent tracks. Therefore, address data distributed to the prepits can duly be reproduced without crosstalk. Since pits 82 for adjacent tracks do not adjoin to each other, they can therefore be formed with ease. Also, pits 82 are uniformly disposed on both sides of a track (a land or a groove) and hence the influence on a tracking servo signal which is caused by the pits 82 can be canceled. Accordingly, tracking offset can be suppressed to a minimum.
[0073] When the medium of the FIG. 6 embodiment is reproduced with the apparatus of FIG. 3 , reproduced signals as shown in FIG. 7 are generated from the prepit area 83 , indicating that data pieces which differ track by track can be obtained and therefore address data is recorded very highly efficiently. Thanks to the use of the Gray code, an address can be reproduced even in the course of inter-track access, ensuring suitability to high-speed access. Further, with the Gray code used, an error hardly occurs even in the presence of crosstalk, thus ensuring suitability to narrowing of tracks.
Embodiment 5
[0074] Referring now to FIG. 8 , there is illustrated in enlarged fragmentary plan view form an optical recording medium according to a fifth embodiment 5 of the present invention. Groove 84 each having a width of 0.7 μm and a depth of 70 nm and lands 85 each having a width of 0.7 μm are arranged alternately in the radial direction and the two kinds of areas serve as information tracks on which recorded marks can be formed.
[0075] In other words, each of the land 85 and groove 84 serves as a recording area. In a prepit region 83 , any groove is not formed but pits 82 are disposed on an extension of the boundary between the land and the groove. The prepit area is divided into zones which are arranged in the radial direction over about 1800 information tracks, that is, 900 grooves.
[0076] The zones are arranged concentrically of the whole of a disc in such a manner that 24 zones in total are in a disc having a radius of 30 to 60 mm. More specifically, in each zone, the number of prepit areas to be detected during one revolution, that is, the sector number is constant and the sector number is larger in an outer zone than in an inner zone.
[0077] An example of structure of each sector 41 is shown in FIG. 9 . The sector 41 has a prepit area 83 at the head of a data recording area.
[0078] As shown in FIG. 8 , the prepit area is divided into a first prepit area 831 and a second prepit area 832 . In the first prepit area 831 , pits 82 are arranged on the upper side (as viewed in the drawing) of the center line of a land 85 and in the second prepit area 832 , pits 82 are arranged on the lower side of the center line of the land 85 . Consequently, for example, when an optical spot 21 scans the land 85 , only pits on either one side are always reproduced and there is no fear that crosstalk will occur between adjacent tracks. Accordingly, address data allotted to the prepits can duly be reproduced without crosstalk. Address data represented by the prepits is recorded in the form of a 1-7 modulation code (having a channel bit length of 0.2 μm). In other words, the linear recording density is 0.3 μm/bit. The relation between the prepit area and the groove in the present embodiment is illustrated in enlarged fragmentary section perspective view form in FIG. 10 .
[0079] In the present embodiment, a gap area 87 is provided between the first and second prepit areas 831 and 832 to space them apart by about 1.0 μm. Since in this embodiment data is recorded pursuant to the 1-7 recording, the gap distance corresponds to a length of about 5 channel bits. The 5 channel bit length is exactly the middle length between the longest mark length (8 channel bit length) and the shortest mark length (2 channel bit length). Therefore, the gap area between the first and second prepit areas can be reproduced having a length which lies between the shortest mark length and the longest mark length even when the pits undergo changes in shape and position during formation of the pits and the optical spot undergoes a change in shape and a change in scanning position (servo offset) thus ensuring very high reliability. In this example, the marks are designed to undergo, at the worst, a total change in position which is suppressed to 0.6 μm (3 channel bit length) and therefore, the effective length (during reproduction) is 2 channel bits in the case of the shortest length and 8 channel bits in the case of the longest length to match the rule of the 1-7 modulation code, thus raising no problem during reproduction. If the detection length is longer than 8 channel bit length, then it will adversely interfere with a special synchronous pattern such as a recorded address mark. If the detection length is shorter than 2 channel bits, then a small mark results which is less than resolution of the reproduction optical spot and cannot be detected. Accordingly, it is preferable that the gap length be suppressed to the middle between the longest mark length and the shortest mark length as in the present embodiment.
[0080] Depending on the specification of a pit forming apparatus, the change in mark position can be suppressed to one channel bit length or less. In this case, the nominal gap length may be suppressed to 3 to 7 channel bit length but the pit forming apparatus for this purpose becomes expensive. There is a high possibility that signals suffer an error attributable to a tracking offset during reproduction and therefore the medium is desired in which preferably, the gap length is exactly the middle between the longest mark length and the shortest mark length permissible for the recording as described hereinbefore.
[0081] In the present embodiment, pits 82 are uniformly disposed on both sides of the center line of a track (a land or a groove) and hence the influence on a tracking servo signal which is caused by the pits 82 can be canceled. Accordingly, the tracking offset can be suppressed to a sufficiently small level. In addition, for example, when a land 85 is reproduced, reproduction of address data at the second prepit area 832 is carried out continuously with reproduction of address data at the first prepit area region 831 . Accordingly, when the two areas are united into one area in which information is arranged to provide address data for one track, an address (track number) of a land and that of a groove can be set independently of each other. In other words, by sequentially reproducing the address data pieces in the first and second prepit areas 831 and 832 , discrimination between the land and the groove can be ensured.
[0082] More particularly, for reproduction of the groove, address data represented by prepits arranged in the first prepit area is made to be identical to that represented by prepits arranged in the second prepit area but for reproduction of the land, address data represented by prepits in the first prepit area is made to be different from that represented by prepits in the second area. When addresses represented by prepits in the first and second prepit areas are different from each other, a correlation may be set up between the two addresses and the efficiency of error correction code can be increased by utilizing the correlation.
[0083] Preferably, synchronous information (VFO) 86 and address data 87 may both be arranged in each of the first and second prepit regions.
[0084] While in this example the prepit area is divided into two of the first and second prepit areas, the number of division which Is plural may suffice. For example, when the number of division is four as shown in FIG. 5 , pits in the first and third prepit areas may be arranged on one side of a groove and pits in the second and fourth prepit areas may be arranged on the other side of the groove. By increasing the number of division of the prepit area, reliability against, for example, defects can be improved.
[0085] Here, a phase change recording material (GeSbTe) is used for the recording film. Accordingly, the recorded mark is formed in the form of an amorphous domain.
[0086] Referring now to FIG. 11 , amounts of positional displacement 963 between prepit areas of adjacent tracks, 961 between prepits of adjacent tracks and 962 between grooves of adjacent tracks in the medium are illustrated in greater detail. In the actual medium, positional displacement sometimes occurs between pits of adjacent tracks owing to various causes taking place during pit formation. Because of the positional displacement amounts 961 , 962 and 963 , the length of gap areas 86 and 87 is increased or decreased.
[0087] In addition to the above positional displacement, various kinds of variations (aberration, servo error and the like) during reproduction also cause apparent positional displacement of reproduced signals. Accordingly, the positional displacement possibly leads to a serious problem. But in the present invention, the nominal length of the gap area is set to the middle length between the shortest mark length and the longest mark length pursuant to the 1-7 modulation code and hence a positional displacement amount of ±0.6 μm is permissible.
[0088] The optical recording medium shown in FIG. 8 can be reproduced with the apparatus shown in FIG. 3 in a similar manner to that described in connection with embodiment 1, bringing about advantages that tracking offset can be reduced to ±0.03 μm or less even when various kinds of external disturbance such as optical aberration are taken into account and in particular, it can be reduced to ±0.015 μm or less under the nominal state devoid of optical aberration.
Embodiment 6
[0089] While the embodiment of FIG. 8 uses the 1-7 modulation coding as the recording modulation coding, the present embodiment uses eight to fourteen modulation (EFM) recording. The channel bit length is about 0.2 μm. In the present recording, the shortest mark length is 3 channel bit length and the longest mark length is 11 channel bit length. Practically, a mark having a length of 12 channel bits or more is available but this type of mark is limited to a special application such as a synchronous pattern. Accordingly, data must avoid inclusion of a pattern which may possibly interfere with the special pattern. The prepit area, groove and land are arranged similarly to the embodiment 5 of FIG. 8 excepting points to be described later. Namely, they are arranged as shown in FIG. 10 and especially, each groove and each have a width of about 0.75 μm and each groove and each prepit have a depth of about 0.075 μm.
[0090] In the present embodiment, the prepit area and the groove are disposed as shown in FIG. 12 . Four prepit areas 831 , 832 , 833 and 834 are allotted to the head of one sector. In each prepit area, a VFO area for synchronization to reproduced signals and an address area recording address data of the track and sector are arranged sequentially. Start positions of pits as well as end positions are so arranged as to be substantially aligned in the radial direction and a gap area 86 is provided between the end of the groove and the start of the pit area. Likewise, a gap area 87 , 88 or 89 is provided between adjacent prepit areas.
[0091] As described previously, details of positional displacement between the start position of a pit and the start position of a succeeding pit is depicted in FIG. 11 . With the displacement as shown in FIG. 11 , the effective length of the gap area 86 is decreased,or increased as in the embodiment 5 of FIG. 8 . In order to align ends of final pits of the prepit areas 831 , 832 and 833 in the radial direction, an additional pit pattern 110 as shown in FIG. 13 is used. The additional pattern selected from four types (a), (b), (c) and (d) in accordance with the preceding data is used. Through this, trailing edge positions 99 of the final pits can always be aligned to the same position regardless of the preceding data and the gap length and pit length can be limited to the lengths allowed for the modulation code. In this manner, the gap area between the succeeding prepit area 120 and the trailing edge position 99 of the final pit can be set to the middle length between the longest mark length and the shortest mark length pursuant to the modulation coding, so that the margin can be greatly increased during prepit formation and reproduction as in the embodiment 5.
[0092] In the foregoing embodiments, the medium of the phase change recording material is described but it may be of another material to attain the advantages of the present invention. For example, a magneto-optical recording film may be used as the recording film. In addition, the modulation code has been described as being of 2-7 and 8/9 coding but it may be of another type in which the previously described EFM is extended.
[0093] According to the present invention, in the optical recording medium having the lands and grooves, the substrate can be fabricated with a simple mastering apparatus and replica can also be prepared with ease, with the result that the medium fabrication margin and readout margin which are practically sufficiently large can be ensured. Accordingly, a cheap and high-density optical recording medium can be provided. | A recording apparatus for recording information to an optical recording medium having an aligned prepit portion straddled on a plurality of tracks in a radial direction, the prepit portion including first and second prepit portions divided in a track direction and arranged on a boundary line of the respective tracks, the first and second prepit portions each having address information prepits arranged at every two-track pitch in the radial direction. The address information prepit of the first and second prepit portions being arranged with one track displaced in the radial direction, and a trailing end of an end prepit of the first prepit portion being aligned with the radial direction. The recording apparatus includes an irradiation source for irradiating a light spot on the optical recording medium, and a controller for controlling an irradiation position of an optical spot from the irradiation source. | 6 |
BACKGROUND
1. Field of the Invention
The present invention relates to speech processing. More specifically, the invention relates to a method and apparatus for enhancing 3-D (three-dimensional) localization of speech.
2. Description of Related Art
Normal human speech contains a wide range of frequency components, usually varying from about 100 Hz (hertz) to several KHz (kilohertz). For instance, human speech has a low frequency fundamental, but the harmonics of human speech has a fairly wide scale. Due to the wide range of frequencies found in human speech, one is able to localize a source of speech when one is speaking to someone. In other words, one is generally able to locate and identify the source of speech with a particular individual.
In order to determine the intelligibility or message of the speech, a listener does not require the higher-frequency components contained in the speech. Therefore, many communication systems, such as cellular phones, video phones and telephone systems that use speech compression algorithms, discard the high-frequency information found in a speech source. Thus, most of the high-frequency content above 4 kilohertz (KHz) is discarded. This solution is adequate when localization of the speech is not needed. But for applications that require or desire localization of the speech (e.g., virtual reality), the loss of the high-frequency components of the speech proves to be detrimental. This is because the higher-frequencies are required for speech localization by a listener. The high-frequency content in speech helps a listener to mentally perceive where a sound is located. For instance, it helps the listener determine whether a sound is located above or below the listener, or to the right or to the left, or in front of or in back of the listener. Thus, what is needed is a method of converting speech that has been transmitted through a communication system that discarded its high-frequency content. This method should allow a listener to localize the converted speech without losing any intelligibility in the speech.
SUMMARY
A computer-implemented method for enhanced 3-D (three-dimensional) localization of speech is disclosed. A speech signal that has been sampled at a predetermined rate per second is received. A maximum frequency for the speech signal is determined. The predetermined rate of sampling is increased. A low-level, wide-band noise is added to the speech signal to create a new speech signal with higher-frequency components.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not a limitation in the figures of the accompanying drawings in which like references indicate similar elements.
FIG. 1 illustrates an exemplary computer system in which the present invention may be implemented.
FIG. 2 is a flow chart illustrating one embodiment of the present invention.
FIG. 3 illustrates one hardware embodiment that may be used in the present invention.
DETAILED DESCRIPTION
A method and apparatus for enhanced 3-D (three-dimensional) localization of speech are described. 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 these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.
The present invention enhances 3-D localization of speech by providing high-frequency content to speech. This is required because the high-frequency content (e.g., higher than 4 KHz) of speech is often removed by speech compression algorithms during transmission. As a result, the high-frequency components in speech, which may be used for spatial localization cues, are lost. Consequently, the listener of compressed and localized speech is unable to accurately perceive the location of a speech source. Thus, the present invention corrects this problem by adding high-frequency, wide-band noise to the compressed speech after increasing its sampling rate and before performing localization.
Referring to FIG. 1, an exemplary computer system upon which an embodiment of the present invention may be implemented is shown as 100. Computer system 100 comprises a bus or other communication device 101 that communicates information, and a processor 102 coupled to the bus 101 that processes information. System 100 further comprises a random access memory (RAM) or other dynamic storage device 104 (referred to as main memory), coupled to a bus 101 that stores information and instructions to be executed by processor 102. Main memory may also be used for storing temporary variables or other intermediate information during execution of instructions by processor 102.
Computer system 100 also comprises a read only memory (ROM) and/or other static storage devices 106 coupled to bus 101 that stores static information and instructions for processor 102. Data storage device 107 is coupled to bus 101 and stores information and instructions. A data storage device 107, such as a magnetic disk or an optical disk, and its corresponding disk drive, may be coupled to computer system 100. Network interface 103 is coupled to bus 101. Network interface 103 operates to connect computer system 100 to a network of computer systems (not shown).
Computer system 100 may also be coupled via bus 101 to a display device 101, such as a cathode ray tube (CRT), for displaying information to a computer user. An alpha numeric input device 122, including alphanumeric in other keys, is typically coupled to bus 101 for communicating information and command selections to processor 102. Another type of user input device is cursor control 123, such as a mask, a trackball, a cursor direction keys for communicating direction information and command selections to processor 102 and for controlling cursor movement on display 121. This input device typically has two degrees of freedom and two accesses, a first access (e.g., X) and a second access (e.g., Y), which allows the device to specify positions in a plane.
Alternatively, other input devices such as a stylist or pen can be used to interact with the display. A displayed object on a computer screen can be selected by using a stylist or pen to touch the displayed object. The computer detects a selection by implementing a touch sensitive screen. For example, a system may also lack a keyboard such as 122 and all the interfaces are provided via the stylist as a writing instrument (like a pen) and the written text is interpreted using optical character recognition (OCR) techniques. In addition, compressed speech signals can also arrive at the computer via communication channels such as an Internet or local area network (LAN) connection.
FIG. 2 illustrates one embodiment of the present invention. In step 200, a digital speech source (signal) is received from a communication network. For example, possible digital speech sources are cellular phones, video phones and video-teleconferencing. In these systems, the high-frequency content (e.g., greater than 4 KHz) found in the speech is often discarded. This is because the high-frequency components of speech are not required for intelligibility of the speech. Furthermore, the high-frequency components of the speech are also discarded by speech compression algorithms.
In step 202, the frequency content of the received digital speech is analyzed. In step 204, the maximum frequency of the digital speech signal is calculated from the sampling rate of the received signal according to Nyquist's Law. In other words, the sampling rate of a signal is assumed to be twice the maximum frequency of the transmitted signal. For example, if the sampling rate of the digital speech source is 8 kilohertz (KHz), then the maximum frequency is equal to half of (8 KHz), which is 4 KHz. Thus, the maximum frequency of the transmitted signal is 4,000 Hertz.
At this point, the high-frequency content of the speech has already been removed (e.g., by a speech compression algorithm) and may not be used to provide directionality via spatial cues. More high-frequency information must be added to the speech to enhance 3-D localization. This is accomplished by first resampling the speech at a higher rate. In step 208, the sampling rate (e.g., 8 KHz) is increased, typically by a factor of two-to-six over the initial sampling rate. In one embodiment, the sampling rate can be increased from 8 KHz to a value ranging between 16 KHz to 48 KHz. In one embodiment, the sampling rate is increased from 8,000 times per second to 22,050 times per second (or about 22 KHz). A sampling rate of 22,050 times per second is the standard sampling rate for mid-range music and is similar to FM (Frequency Modulation) radio quality. For example, at 22 KHz, one hears more than just speech; one is also able to hear the tonal quality of instruments and sound-effects. Thus, the sampling rate is increased, but no additional high-frequency components are added.
In step 210, wide-band Gaussian noise is added to the speech signal with the increased sampling rate. Typically, the added wide-band Gaussian noise is at the Nyquist frequency corresponding to the increased sampling rate. For example, if the sampling rate was increased to 22 KHz or 22,050 times per second, then the wide-band Gaussian noise will also have a frequency band of 11025 hertz or half of the increased sampling rate. It will be appreciated that the Gaussian noise may have a different frequency than the increased sampling rate. It will also be appreciated that the wide-band Gaussian noise can have a frequency that is proportional to the increased sampling rate. In one embodiment, the added wide-band Gaussian noise can range from between about 8 KHz to about 24 KHz. The energy of the wide-band Gaussian noise is usually kept low enough so that it does not interfere with the intelligibility of the speech. As a result, the wide-band Gaussian noise that is added is approximately 20 to 30 decibels lower than the originally received digital speech signal.
The wide-band Gaussian noise adds high-frequency components to the original digital speech source. This is important for enhanced 3-D localization of the sound which may be introduced via a filter, for example, to recreate the speech source for a listener in a virtual-reality experience. In one embodiment, the resulting wide-band speech can be transmitted to a 3-D speech localization routine in a computer system in step 212. In addition, positional information regarding the digital speech source can be added at this time.
Positional information that corresponds to the speech source creates a more realistic virtual experience. For example, if one is in a multi-point video conference with five different people, whose pictures are each visible on a computer screen, then this positional information connects the speech with the appropriate person's picture on the display screen. For instance, if the person, whose picture is shown on the left-hand side of the screen, is speaking, then the speech source should sound like it is coming from the left-hand side of the screen. The speech should not be perceived by the listener as if it is coming from the person whose picture is on the right-hand side of the screen.
Another application for this invention is in a 3-D virtual-reality scene. For example, one is in a shared virtual-space or 3-D room where people are meeting and talking to a 3-D representation of each person. If the 3-D representation of a particular person is speaking audibly and not as text, the present invention should enable the receiver of the speech to connect the speech with the appropriate 3-D representation as the speech source. Thus, if a user were to walk from one group of speakers to another group, the speech received by the user should vary accordingly.
One hardware embodiment 300 of the present invention is illustrated in FIG. 3. A digital speech signal 301 is received by a receiver 303. The digital speech signal 301 is transmitted from a communication network, such as a cellular phone. Often human speech is first received as an analog signal that is then converted to a digital speech signal. This digital speech signal 301 is often compressed or band-limited before it reaches the receiver 303. Thus, high-frequency components (e.g., greater than 4 KHz) of the digital speech signal 301 are often removed.
The receiver 303 also determines the maximum frequency of the received digital speech signal. In one embodiment, the receiver 303 utilizes Nyquist's Law to determine the maximum frequency of the digital speech signal according to the digital sampling rate. For example, if the sampling rate is 6 KHz, then the maximum frequency according to Nyquist's Law is 3 KHz, which is half of the sampling rate. The converter 305 then converts or increases this minimum sampling rate to an increased sampling rate. The increased sampling rate can be, in one embodiment, two-to-six times greater than the previous sampling rate.
A generator 307 then creates wide-band Gaussian noise in order to increase the high-frequency content of the received digital speech signal 301. This is necessary because the high-frequency content of the speech enables a listener to better localize the digital speech. In other words, after 3-D localization, the high-frequency content of the speech enables a listener to determine if the speech source is located to the listener's right or left, or above or below the listener, or in front of or behind the listener. The 3-D localization of the speech enhances a listener's experience of the speech. The speech signal with the increased sampling rate and the wide-band Gaussian noise are combined in the adder 309. The resulting wide-band speech signal is then stored in a memory 311 before being transmitted, in one embodiment, to a filter generation unit 313. This filter may be a finite-impulse response (FIR) filter in one embodiment. It is to be appreciated that other filters can be used. In the prior art, the digital speech signal 301, without its high-frequency content (e.g., above 4 KHz) was often directly transmitted to the filter generation unit 313. As a result, the resulting digital speech often lacked perceptible 3-D localization cues. In sharp contrast, the present invention allows a listener to have enhanced 3-D localization capabilities or perception of a speech source. Thus, the listener enjoys a more realistic experience of the speech source.
In the above description, numerous specific details were given to be illustrative and not limiting of the present invention. It will be apparent to one skilled in the art that the invention may be practiced without these specific details. Furthermore, specific speech processing equipment and algorithms have not been set forth in detail in order not to unnecessarily obscure the present invention. Thus, the method and apparatus of the present invention is defined by the appended claims.
Thus, a method is described for enhancing 3-D localization of a speech source. | A computer-readable medium stores sequences of instructions to be executed by a processor. These instructions cause the processor to perform the following steps to enhance 3-D localization of a speech source. A digital speech signal is received. The maximum frequency of the digital speech signal is determined. The sampling rate of the digital speech signal is increased. Next, wide-band Gaussian noise is added to the digital speech signal to create a wide-band digital speech signal with higher frequencies. Finally, the wide-band digital speech signal can be localized via an FIR (finite impulse response) filter. | 6 |
BACKGROUND
1. Technical Field
The disclosure generally relates to industrial gas turbine engines.
2. Description of the Related Art
Industrial gas turbine engines are used in a variety of applications such as power generation, for example. Oftentimes, efforts to improve the efficiency of these engines become difficult as emission requirements tend, over time, to become more stringent.
SUMMARY
Premix nozzles and gas turbine engine systems involving such nozzles are provided. In this regard, an exemplary embodiment of a premix nozzle for an industrial gas turbine engine comprises: a housing defining an interior and having an outlet communicating with the interior, the housing further having a housing opening communicating with the interior, the housing opening being operative such that air exterior to the housing is drawn into the interior of the housing through the housing opening, mixed with fuel, and directed out of the housing through the outlet; and a valve contacting the exterior of the housing and having a valve opening, the valve being movable between an open position, in which the valve opening is aligned with the housing opening such that air exterior to the housing is drawn into the interior of the housing through the valve opening and the housing opening, and a closed position, in which a reduced amount of air exterior to the housing is drawn into the interior.
An exemplary embodiment of a nozzle assembly for a combustion section of an industrial gas turbine engine comprises: an array of shuttered nozzles, each of the shuttered nozzles comprising: a housing defining an interior and having an outlet communicating with the interior, a housing opening communicating with the interior, the housing opening being operative such that air exterior to the housing is drawn into the interior of the housing through the housing opening, mixed with fuel, and directed out of the housing through the outlet; and a valve located exterior to the housing and having a valve opening, the valve being movable between an open position, in which air exterior to the housing is drawn into the interior of the housing through the valve opening and the housing opening, and a closed position, in which a reduced amount of air exterior to the housing is drawn into the interior.
An exemplary embodiment of an industrial gas turbine engine comprises: a combustion section having a nozzle assembly operative to provide a fuel-air mixture for combustion, the nozzle assembly having an array of shuttered nozzles and non-shuttered nozzles; each of the shuttered nozzles being operative in an open position, in which air is directed through the shuttered nozzle for mixing with fuel, and a closed position, in which a reduced amount of air is directed through the shuttered nozzle; each of the shuttered nozzles being operative to independently alter an amount of air being directed therethrough.
Other systems, methods, features and/or advantages of this disclosure will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be within the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a schematic diagram of an embodiment of an industrial gas turbine engine.
FIG. 2 is a schematic diagram of the embodiment of FIG. 1 showing orientation of premix nozzles of a nozzle assembly.
FIG. 3 is a partially cut-away view of an embodiment of a premix nozzle.
FIG. 4 is a partially cut-away view of the embodiment of FIG. 3 as viewed along line 4 - 4 .
DETAILED DESCRIPTION
Premix nozzles and gas turbine engine systems involving such nozzles are provide, several exemplary embodiments of which will be described in detail. In this regard, some embodiments involve the use of gas actuated shutter valves for metering the flow of air entering the nozzles. In some of these embodiments, such a shutter valve incorporates ports that selectively align with corresponding ports located on a housing of the nozzle. When the ports of the valve are aligned with the ports of the housing, air can enter the interior of the nozzle and mix with the fuel.
Referring to the schematic diagram of FIG. 1 , an exemplary embodiment of an industrial gas turbine engine is depicted. As shown in FIG. 1 , engine 100 incorporates a compressor section 102 , a combustion section 104 and a turbine section 106 , each of which is oriented along a longitudinal axis 108 . Compressor section 102 includes a low pressure compressor 110 and a high pressure compressor 112 . The turbine section 106 includes a high pressure turbine 114 , a low pressure compressor 116 and a power turbine 118 .
In operation, a fuel-air mixture provided to combustion section 104 is combusted and directed to the high pressure and low pressure turbines. A high shaft 120 interconnects the high pressure turbine and the high pressure compressor, and a low shaft 122 interconnects the low pressure turbine and the low pressure compressor. Exhaust from the low pressure turbine is directed to power turbine 118 , which is a free turbine, i.e., the power turbine is not rotated via a shaft that is interconnected with the high and/or low turbines.
FIG. 2 schematically depicts a portion of combustion section 104 . In particular, FIG. 2 depicts an annular assembly 130 of nozzles (e.g., nozzle 132 ) that provide fuel and air for combustion within combustion section 104 . In the embodiment of FIG. 2 , two types of nozzles are depicted. Specifically, shuttered nozzles (e.g., nozzle 132 ) and non-shuttered nozzles (e.g., nozzle 133 ) are provided. In the embodiment of FIG. 2 , each of the nozzle types forms an array of nozzles, with the eight nozzles of the array 134 of shuttered nozzles being interleaved with the eight nozzles of the array 135 of non-shuttered nozzles. This results in the nozzles of this embodiment alternating between shuttered and non-shuttered types about the circumference of assembly 130 . Notably, in other embodiments, various other numbers and/or orientations of nozzles can be used.
In operation, the non-shuttered nozzles of array 135 are used to provide fuel and air to combustion section 104 regardless of the demand for power. However, as an increase in power is requested, fuel and air is provided from the shuttered nozzles of array 134 in increasing increments that correspond to the amount of power requested. In this embodiment, each incremental increase in the metered flow of fuel and air corresponds to actuating another of the shuttered nozzles. Specifically, at 50% power, nozzle assembly 130 is controlled so that only the non-shuttered nozzles provide fuel and air for combustion. As an increase in power is requested, such as when power is requested at 56.66% power, for instance, a first shuttered nozzle is controlled so that fuel and air is now also provided from that shuttered nozzle. For each additional increment of requested power (in this case, each 6.66% increment), another shuttered nozzle is controlled to direct fuel and air. Notably, each increment in this embodiment corresponds to a 6.66% increase in power because there are eight shuttered nozzles providing additional fuel and air over a power range of 50%. In other embodiments, various other numbers and/or increments can be used.
The opening sequence of the shuttled nozzles of array 134 involves opening nozzles on opposite sides of the array sequentially in order to promote balanced combustion. By way of example, after nozzle 132 is opened, nozzle 142 is opened. Thereafter, nozzles 138 , 146 , 136 , 144 , 148 and 140 are opened in sequence. Clearly, various other opening sequences can be used in other embodiments. A representative closing sequence involves closing the nozzles sequentially, but in the reverse order.
It should be noted that in the embodiment of FIG. 2 , each shuttered nozzle selectively exhibits a closed position, in which air and fuel are not provided by the nozzle for combustion, an open position, in which air and fuel are provided, or an intermediate position, in which the nozzle is transitioning between the open and closed positions. In other embodiments, shuttered nozzles can be controlled to selectively maintain one or more of a range of intermediate positions that provide varying flows of fuel and air between the flow available at the closed position (i.e., no flow) and the open position (i.e., maximum flow). In such an embodiment, one or more of the shuttered nozzles can be modulated as desired (such as responsive to a feedback signal) for distributing the fuel and air among the nozzles.
An embodiment of a shuttered nozzle is depicted in FIG. 3 . As shown in FIG. 3 , nozzle 150 incorporates a housing 152 that extends between an end 154 and an end 156 . End 154 is used for mounting the nozzle to the combustion section of an engine and, in this embodiment, receives fuel provided by fuel lines 157 , 158 . Fuel and air mixed within the nozzle are expelled via an outlet 159 located at end 156 . Notably, housing 152 incorporates housing openings (e.g., opening 160 ) that permit air to flow from the exterior of the housing to the interior 162 of the housing for mixing with the fuel.
As shown in FIG. 4 , airflow to the interior of the housing is controlled by valve 170 , which also incorporates valve openings (e.g., opening 172 ). In the open position of the nozzle, valve 170 is controlled so that openings of the valve align with openings of the housing. In contrast, in the closed position of the nozzle, valve 170 is controlled so that openings of the valve do not align with openings of the housing, thereby restricting the flow of air into the nozzle.
In particular, when engine power reduction is required fuel is reduced. At a predetermined setting fuel is shut off to a nozzle and valve 170 is closed. Fuel is redistributed among the open nozzles (and/or partially open nozzles). Simultaneously, air also is redistributed among the nozzles that are at least partially opened. Notably, FIG. 4 depicts an intermediate position (i.e., partially opened), in which the openings of the valve are partially aligned with openings of the housing. This tends to promote lower exhaust emissions at reduced power settings.
Positioning of valve 170 is controlled by providing pressurized fluid to one side or the other of a piston head 180 that is housed within an annular cavity 182 . By way of example, providing pressurized fluid to side 184 of piston head 180 via line 185 causes the piston head (and the attached piston body 186 , which defines the valve openings) to move toward end 156 to achieve the open position. In contrast, providing pressurized fluid to side 188 via line 189 causes the piston head and piston body to move to the closed position.
It should be noted that the pressurized fluid can be one of a variety of fluids and, in some embodiments, may even be the same fluid used as the fuel, e.g., natural gas. In some embodiments, providing of pressurized fluid for controlling the piston position can be accomplished by use of one or more solenoids, for example.
Note also that, in the embodiment of FIGS. 3 and 4 , the piston body 185 is cylindrical in shape to correspond to the exterior shape of the corresponding portion 190 of the housing. In other embodiments, various other shapes of piston bodies and housings can be used.
In some applications, shuttered nozzles, such as the exemplary embodiments described above, can be used as retrofit components on gas turbine engines. By way of example, some engines may incorporate nozzles (e.g., non-shuttered nozzles) that are not configured for selectively reducing both the amount of fuel and air provided for combustion. That is, when fuel is cut off to a nozzle, air may still be provided for combustion via that nozzle. In such an engine, at least a subset of the nozzles may be replaced using shuttered nozzles. As such, an improvement in emission quality may be exhibited as a decrease in requested power of the retrofit engine may result in fuel and air being cut off to one or more of the shuttered nozzles and redistributed to the non-shuttered nozzles.
It should be emphasized that the above-described embodiments are merely possible examples of implementations set forth for a clear understanding of the principles of this disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the accompanying claims. | Premix nozzles and gas turbine engine systems involving such nozzles are provided. In this regard, a representative industrial gas turbine engine includes: a combustion section having a nozzle assembly operative to provide a fuel-air mixture for combustion, the nozzle assembly having an array of shuttered nozzles and non-shuttered nozzles; each of the shuttered nozzles being operative in an open position, in which air is directed through the shuttered nozzle for mixing with fuel, and a closed position, in which a reduced amount of air is directed through the shuttered nozzle; each of the shuttered nozzles being inoperative to independently alter an amount of air being directed therethrough. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to liquid crystal display devices and, more particularly, to a liquid crystal display apparatus suitable for projecting a graphic pattern or the like, written on a liquid crystal cell, onto a screen by using a liquid crystal light emitter actuated by the heat from a laser beam.
2. A Description of the Prior Art
As conventional liquid crystal display apparatus based on a liquid crystal light emitter actuated by the heat from a laser beam, there is known a projection type display or the like in which a laser beam is irradiated on a liquid crystal cell formed of a liquid crystal of smectic phase and an image written in the liquid crystal cell is projected onto a screen by utilizing a thermoelectric optical effect.
FIG. 1 of the accompanying drawings shows a structure of an optical system of the above conventional projection type liquid crystal display apparatus based on a liquid crystal light emitter actuated by the heat from a laser beam.
As shown in FIG. 1, a laser beam emitted from a laser diode 30 disposed within a laser block 1 is traveled through galvanoscanner mirrors 3a, 3b, which deflect a laser beam on a liquid crystal cell 7 (described later on) in the Y-axis direction and X-axis direction, a relay lens 2, a first condenser lens 4, and then reflected on a dichroic mirror 5 to become a writing laser beam 6. This writing laser beam 6 is focused on a liquid crystal surface of the liquid crystal cell 7. A point at which the writing laser beam 6 radiates the liquid crystal cell 7 is held in this state.
The writing laser beam 6 irradiated on the surface of the liquid crystal cell 7 is scanned by the two Y-axis and X-axis galvanoscanner mirrors 3a, 3b to thereby draw a graphic pattern or the like on an arbitrary position on the liquid crystal surface of the liquid crystal cell 7.
The graphic pattern or the like drawn on the liquid crystal surface of the liquid crystal cell 7 is projected on to a screen 9 by means of a projection light 10 from a projection lamp 8. That is, the projection light 10 from the projection lamp 8 is converged by a condenser lens 11 and irradiated on the the liquid crystal cell 7 from its rear side through the dichroic mirror 5, whereby the graphic pattern or the like on the liquid crystal surface of the liquid crystal cell 7 is projected on to the screen 9 via a projection lens 12.
A theory in which the graphic pattern or the like is drawn on the surface of the liquid crystal cell 7 by the heat from the laser beam as described above will be described with reference to FIGS. 2A through 2D of the accompanying drawings. As illustrated, the liquid crystal cell 7 comprises two glass substrates 14 and 15. Transparent electrode layers 16, 17 made of indium oxide-tin oxide (ITO) or the like and insulating layers 18, 19 made of silicon dioxide (SiO 2 ) or the like are respectively coated on the glass substrates 14, 15. A laser mirror 20 is formed on the glass substrate 14 which is located on the opposite side of the glass substrate 15 into which the writing laser beam 6 is introduced. The laser mirror 20 is formed of a dielectric optical multi-layer.
A space or vacant cell between the two glass substrates 14 and 15 is sealed by a sealing material 21 such as a thermosetting resin or the like.
A smectic liquid crystal 24 or the like is filled into the vacant cell sealed by the sealing material 21. The smectic liquid crystal 24 may be formed of a liquid crystal whose phase is changed in the order of a smectic A phase, a nematic phase and an isotropic phase.
If the liquid crystal 24 is returned in phase to the original smectic A phase after the phase transition from the smectic A phase to the isotropic phase occurred due to the heat from a laser beam, then a random orientation in the isotropic phase is retained in the smectic A phase and the light scattering state is formed, thereby retaining the memory state. If this memory state is erased, then the phase of the liquid crystal 24 is returned to the smectic A phase of the regular alignment by the application of a voltage.
The transparent electrode layers 16, 17 are formed in order to apply the voltage to the liquid crystal cell 7 when a displayed image is erased, while the insulating layers 18, 19 are formed in order to prevent the transparent electrode layers 16, 17 from being short-circuited by impurities doped into the liquid crystal 24. Further, the laser mirror 20 is coated on the glass substrate 14 in order to reflect the writing laser beam 6 introduced thereto from the laser diode 30 to thereby effectively utilize the energy of the laser beam.
A switch 22 and an AC power supply 23 are connected in series between the transparent electrode layers 16 and 17 of the above liquid crystal cell 7.
In the state shown in FIG. 2A, the switch 22 is in its off state and the liquid crystal 24 is in the smectic A phase of the regular alignment.
Then, when the writing laser beam 6 is introduced into the liquid crystal cell 7 from the glass substrate 15 side as shown in FIG. 2B, only a liquid crystal 24a irradiated with the writing laser beam 6 is changed in phase to the isotropic phase of the light scattering state and becomes a pixel 25 as shown in FIG. 2C so that a predetermined image may be drawn.
Then, when the switch 22 is turned on to apply a voltage across the transparent electrode layers 16, 17 from the AC power supply 23 as shown in FIG. 2D, the isotropic phase of the liquid crystal 24 is returned to the original smectic A phase of the regular alignment.
FIG. 3 of the accompanying drawings shows a structure of the optical system disposed within the above laser block 1 in the conventional liquid crystal display apparatus. In FIG. 3, like parts corresponding to those of FIG. 1 are marked with the same references and therefore need not be described in detail.
As shown in FIG. 3, a laser beam emitted from the laser diode 30 is introduced through a collimator lens 31 and an anamorphic prism 32 into a half-wave plate 33. A laser beam of a linear polarized P-component, for example, emitted from the laser diode 30 is collimated by the collimator lens 31. Then, the collimated laser beam from the collimator lens 31 is changed in spot shape from ellipse to circle by the anamorphic prism 32. A part of the laser beam (i.e., less than several percents) is changed by the half-wave plate 33 to a linear polarized S-component whose vibration direction is rotated 90 degrees.
The linear polarized P-component and S-component from the half-wave plate 33 are introduced into a polarizing beam splitter 34, in which they are separated into a traveling light and a reflected light. The S-component whose light amount is about 1 to 2% is reflected by the polarizing beam splitter 34 whereas other P-component is passed through the polarizing beam splitter 34.
The S-component reflected by the polarizing beam splitter 34 is converged by a collimator lens 35 that serves to monitor a laser beam and introduced into a photodiode 36 that is used to monitor the laser beam from the laser diode 30.
The laser beam passed through the polarizing beam splitter 34 is introduced into a quarter-wave plate 37. The linear polarized P-component is changed by the quarter-wave plate 37 into a circular polarized P-component and scanned by the galvanoscanner mirrors 3a, 3b shown in FIG. 1 so that it is focused on the liquid crystal 24 of the liquid crystal cell 7 as the writing laser beam 6, thereby writing a predetermined graphic pattern on the surface of the liquid crystal 24.
A position detecting reflected-back beam 39 that has been reflected by a reflecting layer (e.g., aluminum layer) 40 or the like disposed on predetermined positions (e.g., top and end of and right and left of X-axis and Y-axis directions) of the panel surface of the liquid crystal cell 7 is returned again into the laser block 1 by means of the galvanoscanner mirrors 3a, 33b. Of course, although the writing laser beam 6 is irradiated on the liquid crystal 24 of the liquid crystal cell 7 as the heat energy to change the liquid crystal cell 24 in phase from the smectic A phase to the isotropic phase thereby drawing a graphic pattern or the like, other extra energy is returned into the laser block 1 as the reflected-back beam 39.
The reflected-back beam 39 returned into the laser block 1 is changed again into the linear polarized S-component by the quarter-wave plate 37. The S-component is reflected by the polarizing beam splitter 34 and introduced into a collimator lens 41 that is used to detect a drawing position and a photodiode 42.
Further, when the surface of the liquid crystal cell 7 is scanned by the galvanoscanner mirrors 3a, 3b in the liquid crystal display apparatus based on a liquid crystal light emitter actuated by the heat from the laser beam, an automatic power control (APC) is effected such that an output power density of the laser diode 30 is made constant in response to the drawing speed.
FIG. 4 of the accompanying drawings shows in block form a conventional circuit for controlling a laser power density. In FIG. 4, like parts corresponding to those of FIGS. 1 and 3 are marked with the same references and therefore need not be described in detail.
As shown in FIG. 4, the laser block 1 that was earlier described with reference to in FIG. 3 includes therein the laser diode 30 serving as the laser beam source and the photodiode 36 that monitors the output of the laser diode 30. The output from the laser diode 30 which is detected by the photodiode 36 is fed through a current-to-voltage converter circuit 44 back to one input terminal of a comparator circuit 45 formed of an amplifier. Further, an output from the comparator circuit 45 is converted into a current by a voltage-to-current converter circuit 46 which is controlled by a pulse width modulation (PWM) wave from a PWM controller circuit 47 and then supplied to the laser diode 30 so that the output of the laser diode 30 is made constant.
The PWM controller circuit 47 and the comparator circuit 45 are both controlled by a computer (hereinafter referred to as a CPU (central processing unit)) 48 forming a system controller.
A reference voltage from a reference voltage setting circuit 52 is supplied to the other input terminal of the comparator circuit 45.
The reference voltage setting circuit 52 includes a first variable resistor VR 1 that sets a reference voltage used to draw a bold line, a second variable resistor VR 2 that sets a reference voltage used to draw a middle line and a third variable resistor VR 3 that sets a reference voltage used to draw a fine line. The first to third variable resistors VR 1 to VR 3 are connected in parallel to one another, and one common junction thereof is grounded, whereas the other common junction thereof is connected to the cathode of a power supply 53 whose anode is grounded. Thus, the output laser power is set such that it is maximized at the ground potential.
One ends of the sliding contacts of the first to third variable resistors VR 1 to VR 3 are connected to three-state circuits 55a, 55b and 55c each constructing a line-width reference voltage selector. Outputs of the three-state circuits 55a, 55b and 55c are commonly connected to the other input terminal of the amplifier that constructs the comparator circuit 45.
Laser drive signals LD 0 , LD 1 are output from the CPU 48 and fed to a decoder 54. The decoder 54 turns off the laser drive signal when the laser drive signal LD 0 is at "H" (high) level and the laser drive signal LD 1 is at "H" (high) level; the decoder 54 supplies a line type switching signal representative of a fine line drawing to the gate of the three-state circuit 55c when the laser drive signal LD 0 is at "L" (low) level and the laser drive signal LD 1 is at "H" (high) level; the decoder 54 supplies a line type switching signal representative of a middle line drawing to the gate of the three-state circuit 55b when the laser drive signal LD 0 is at "H" (high) level and the laser drive signal LD 1 is at "L" (low) level; and the decoder 54 supplies a line type switching signal representative of a bold line drawing to the gate of the three-state circuit 55a when the laser drive signal LD 0 is at "L" (low) level and the laser drive signal LD 1 is at "L" (low) level. Accordingly, reference voltages set by the resistance values of the variable resistors VR 1 through VR 3 in response to the types of the drawing lines are supplied to the comparator circuit 45 so that the output laser power of the laser diode 30 is made constant.
Potentiometers (X-axis and Y-axis scanners though not shown) or the like of an X-axis scanner driver circuit 50 and a Y-axis scanner driver circuit 51, controlled by the CPU 48 so as to drive the galvanoscanner mirrors 3a, 3b, are varied to output X-and Y-axis line drawing speed voltages V x and V y . Then, in response to the control signals from the CPU 48, the X-axis scanner driver circuit 50 and the Y-axis scanner driver circuit 51 drive galvano-motors 3 a 1 and 3 b 1 of the galvanoscanner mirrors 3a, 3b.
In the liquid crystal display apparatus based on the liquid crystal cell 7 actuated by the heat energy from the laser beam, as X-position signal V x and the Y-position signal V y supplied to the galvano-motors 3 a 1, 3 b 1 of the galvanoscanner mirrors 3a, 3b from the X-axis and Y-axis scanner driver circuits 50, 51, there are supplied sawtooth-waveform signals 56, 57 relative to the X axis and Y axis within the display area of the liquid crystal cell 7 as shown in FIG. 5.
As described above, in the conventional liquid crystal display apparatus based on the liquid crystal cell 7 actuated by the heat energy from the laser beam, the laser peak power is made constant in response to the line types regardless of the position at which a line is drawn. More specifically, the reference voltage that is determined by the set line width to be drawn is set by the reference voltage setting circuit 52 and supplied to the amplifier 45 forming the comparator circuit as the reference voltage, whereby the constant laser power output is generated from the laser diode 30.
However, when the laser peak power of the laser diode 30 is made constant irrespective of the line drawing position as described above, the following problems occur. That is, when the writing laser beam 6 is not properly focused on the interlayer of the liquid crystal 24 of the liquid crystal cell 7 due to the influence of the optical lens and the optical path difference upon drawing or a temperature at which a line is drawn on the liquid crystal 24 of the liquid crystal cell 7 by the heat energy from the writing laser beam 6 is not uniformly distributed, if the voltage of the variable resistor VR 1 is adjusted such that a line width 58 of a graphic pattern projected onto the display area of the liquid crystal cell 7 or on the screen 9 becomes a predetermined line width, e.g., bold line width at the central portion of the screen 9, then the line width 58 is reduced in width or cannot be drawn at all on the peripheral portion of the screen 9 as shown in FIG. 5.
FIG. 6 of the accompanying drawings shows another example of the conventional laser power density controller circuit. In FIG. 6, like parts corresponding to those of FIGS. 1, 3 and 4 are marked with the same references and therefore need not be described in detail.
As shown in FIG. 6, the laser diode drive data LD 1 , LDO are supplied from the CPU 48 to high-order addresses A 1 5, A 1 4 of the ROM (read-only memory) in the vector generator circuit 49 and also supplied to the power controller circuit (comparator circuit) 45. The ROM 49 derives laser-off data, fine line drawing data, middle line drawing data and bold line drawing data. In the laser diode drive data map stored in the ROM 49, an address of bold line, for example, is set to FF H , an address of middle line is set to BF H and an address of fine line is set to 7F H , respectively, whereby the maximum output powers of the laser diode 30 are made constant in response to the types of lines to be drawn.
Further, the X-axis scanning driver circuit 50 and the Y-axis scanning driver circuit 51 which drive the galvanoscanner mirrors 3a, 3b are operated to generate X-axis and Y-axis line drawing speed voltages V x and V y by varying the potentiometers thereof or the like. These voltages V x , V y are supplied to and converted into digital data by analog-to-digital (A/D) converter circuits 62, 63, respectively. Then, these digital data are supplied to lower-order bit addresses A 0 to A 6 and A 7 to A 1 3 of the ROM 49. Then, the output data X, Y corresponding to the drawing speeds and which are stored in the ROM 49 are supplied to the galvano-motors 3 a 1, 3 b 1 of the galvanoscanner mirrors 3a, 3b or the like, thereby constructing the laser driver unit 60.
In the projection type liquid crystal display apparatus based on the liquid crystal cell 7 that is actuated by the heat energy from the laser beam, as data corresponding to the drawing speed when the bold line drawing data, for example, is selected and which is derived from the ROM 49, there is stored data of value which is shown by a straight line 154 having a predetermined inclination in FIG. 7. In this case, the above drawing speed is a speed which results from synthesizing an X-axis indication speed V x and a Y-axis indication speed V y in a vector fashion.
Furthermore, the laser power of the laser diode 30 is controlled by varying pulse widths τ 1 and τ 2 of the pulse-width modulated (PWM) waveform in response to the drawing speed as shown in FIGS. 8A and 8B. That is, in the control of the laser power of the laser diode 30, the laser peak power is set and fixed in response to the types of lines to be drawn and the pulse width modulation is carried out in response to the drawing speed.
Bold line, middle line and fine line of predetermined widths are drawn on the liquid crystal surface of the liquid crystal cell 7 in response to the drawing speeds under the condition such that the laser power density of the laser diode 30 is made constant. However, if these lines are drawn on the liquid crystal surface of the liquid crystal cell 7 under the same laser power density in the beginning of and during the drawing, there is then the defect that the line width when the drawing is just started is reduced.
A cause that the line width is unavoidably reduced in the beginning of the drawing of line will be described with reference to FIG. 9.
As shown in FIG. 9 of the accompanying drawings, when bold lines 159a, 159b having a width W and lengths L 1 , L 2 , for example, are drawn on the liquid crystal cell 7 by the heat energy from the laser beam, the liquid crystal 24 is not heated sufficiently in the beginning of the drawing where a laser beam spot 156 of the laser beam from the laser diode 30 is irradiated on a position shown by a broken line portion 155 so that the liquid crystal 24 is not changed in phase to the isotropic phase. Under this condition, the beam spot 156 is moved at a predetermined drawing speed in the direction shown by an open arrow A in FIG. 9 so that a condition in which a temperature is raised becomes different from that in the beginning of the drawing because a midway portion 158 in which a beam spot 156a that has moved to the next position is moved is pre-heated.
That is, only a hatched portion 157 in the bold line 159b is written. Consequently, the line width in the beginning of the drawing is reduced so that the bold lines 159a, 159b having the predetermined lengths L 1 , L 2 cannot be drawn as they are instructed.
Furthermore, as shown in FIG. 3, although the writing laser beam 6 within the laser block 1 contributes to the drawing as the energy for changing the liquid crystal 24 in phase from the smectic A phase into the isotropic phase when it irradiates the liquid crystal 24 disposed within the liquid crystal cell 7, the extra energy is introduced into the photodiode 42 as a reflected-back light 39. The reflected-back beam 39 that has been reflected on the surface of the photodiode 42 is changed into a scattering beam 43. While the scattering beam 43 is partly reflected on the polarizing beam splitter 34, a part of the scattering beam 43 is passed through the polarizing beam splitter 34 and then introduced into the monitor photodiode 36.
In the above-mentioned liquid crystal display apparatus based on a liquid crystal light emitter actuated by the heat from the laser beam, the output laser power of the laser beam from the laser diode 30 relative to the drawing speed of the writing laser beam when the drawing is effected is controlled by the PWM system so that, if the output level of the laser diode 30 is varied, then the line width of the line to be drawn or the like is changed significantly.
For this reason, the output level of the laser diode 30 must be monitored accurately. Therefore, in the optical system shown in FIG. 3, the output level of the laser diode 30 is monitored by the monitor photodiode 36 and the detected output of the photodiode 36 is fed back to the laser diode 30 in an APC fashion,thereby stabilizing the output power of the laser diode 30.
However, if the scattering beam 43 whose intensity is fluctuated is introduced into the monitor photodiode 36 from the position detection photodiode 42, then the output power of the laser diode 30 is fluctuated.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a liquid crystal display apparatus in which the aforesaid shortcomings and disadvantages of the prior art can be eliminated.
More specifically, it is an object of the present invention to provide a liquid crystal display apparatus in which a line of a uniform line width can be drawn on the whole surface of a display area of a screen or liquid crystal cell.
Another object of the present invention is to provide a liquid crystal display apparatus in which an output of a laser diode can be stabilized.
A further object of the present invention is to provide a liquid crystal display apparatus which can be simplified in structure.
According to an aspect of the present invention, there is provided a liquid crystal display apparatus which comprises a laser beam source for emitting a laser beam, a liquid crystal cell for providing an image by means of the effect of the laser beam heating and which contains a liquid crystal layer positioned between a pair of substrates, scanning devices for scanning the laser beam to the liquid crystal layer to thereby produce a line drawing, and a modulation device for modulating a line width of the line drawing so as to keep a uniform line width.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing a structure of an optical system in a conventional liquid crystal display apparatus;
FIGS. 2A through 2D are diagrams used to explain a principle with which the conventional liquid crystal display apparatus shown in FIG. 1 is operated, respectively;
FIG. 3 is a diagram showing a structure of an optical system disposed within a laser block of the conventional liquid crystal display apparatus;
FIG. 4 is a block diagram of a laser driver unit of the conventional liquid crystal display apparatus;
FIG. 5 is a diagram used to explain a position signal of the conventional liquid crystal display apparatus;
FIG. 6 is a block diagram of another example of a laser driver unit of the conventional liquid crystal display apparatus;
FIG. 7 is a characteristic graph graphing measured results of characteristics of an image drawing speed versus ROM output;
FIGS. 8A and 8B are respectively diagrams showing a relation between ROM outputs and PWM waveforms;
FIG. 9 is a diagram used to explain the image drawing condition of the conventional liquid crystal display device;
FIG. 10 is a block diagram showing a first embodiment of a laser driver unit of a liquid crystal display apparatus according to the present invention;
FIG. 11 is a diagram used to explain an output waveform of a first absolute value generator circuit used in the liquid crystal display apparatus according to the first embodiment of the present invention;
FIG. 12 is a diagram used to explain an output waveform of a second absolute value generator circuit used in the liquid crystal display apparatus according to the first embodiment of the present invention;
FIG. 13 is a diagram used to explain a method of adjusting gain and balance adjustment variable resistors of the liquid crystal display apparatus according to the first embodiment of the present invention;
FIG. 14 is a diagram used to explain a set reference voltage in the liquid crystal display apparatus according to the first embodiment of the present invention;
FIG. 15 is a diagram showing a memory map of a ROM (read-only memory) used in a liquid crystal display apparatus according to a second embodiment of the present invention;
FIG. 16 is a characteristic diagram used to explain a relation between a drawing speed and a ROM output in the liquid crystal display apparatus according to the second embodiment of the present invention;
FIG. 17 is a block diagram showing a second embodiment of the laser driver unit according to the liquid crystal display apparatus according to the present invention;
FIGS. 18A and 18B are respectively diagrams of waveforms used to explain operation of the liquid crystal display apparatus according to the second embodiment of the present invention;
FIGS. 19A and 19B are respectively diagrams used to explain lines drawn by the liquid crystal display apparatus according to the second embodiment of the present invention;
FIG. 20 is a diagram showing an entire structure of a liquid crystal display apparatus according to a third embodiment of the present invention; and
FIG. 21 is a block diagram showing a structure of an optical system provided within a laser block used in the liquid crystal display apparatus according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A liquid crystal display apparatus according to a first embodiment of the present invention will now be described with reference to FIGS. 10 to 14. In FIGS. 10 to 14, like parts corresponding to those of FIGS. 1 to 9 are marked with the same references and therefore need not be described in detail.
FIG. 10 of the accompanying drawings shows in block form the whole circuit of a laser driver unit according to the first embodiment of the present invention, wherein like parts corresponding to those of FIG. 4 are marked with the same references. According to this embodiment, the arrangement of FIG. 10 is different from that of FIG. 4 in that a position adjusting circuit 61 is provided at the preceding stage of the reference voltage setting circuit 52 that sets a reference voltage in response to the type of line to be drawn.
As shown in FIG. 10, the position adjusting circuit 61 comprises first and second absolute value generator circuits 162, 163 to which there are respectively supplied the X-position signal voltage V x and the Y-position signal voltage V y (see FIG. 5) from the X-axis and Y-axis scanning driver circuits 50, 51 and an adder circuit 164 to which the outputs of the first and second absolute value generator circuits 162, 163 are supplied. An output of the adder circuit 164 is connected to the ground potential that is provided in the reference voltage setting circuit 52 as shown in FIG. 4.
The first and second absolute value generator circuits 162 and 163 are arranged so as to generate output signals whose waveforms are illustrated in FIGS. 11 and 12. That is, the X-axis position signal V x supplied to the input of the first absolute value generator circuit 162 is selected so that it is held at the maximum voltage level at the left end and right end of the display area of the screen 9 or the liquid crystal cell 7.
Similarly, the Y-axis position signal V y supplied to the input of the second absolute value generator circuit 163 is selected so that it is held at the maximum voltage level at the upper end and lower end of the display area of the screen 9 or the liquid crystal cell 7.
More specifically, the first and second absolute value generator circuits 162 and 163 each include a gain adjustment variable resistor VR 4 that determines the gain correcting amount and a variable resistor VR 5 that determines a balance to be adjusted. The variable resistors VR 4 , VR 5 are not shown in FIG. 10 but will be described later on with reference to FIG. 13. Accordingly, by adjusting the X-axis and Y-axis gain and balance adjustment variable resistors VR 4 and VR 5 , a relation between the voltage level and the screen position can be freely adjusted such that a waveform 165 shown by one-dot chain line in FIG. 13 and whose voltage level is zero at the center position of the screen 9 is changed to a waveform 166 shown by a solid line whose zero-cross point 168 is moved toward the right end or toward the lower end of the screen 9 or to a waveform 167 whose zero-cross point 168 is moved toward the left end or toward the upper end of the screen 9 as shown by a broken-line in FIG. 13.
With reference to FIG. 14, let us calculate set reference voltages V s c and V s s when a voltage waveform of a predetermined level which results from adding both outputs of the first and second absolute value generator circuits 162 and 163 by the adder circuit 164 is supplied to the variable resisters VR 1 to VR 3 of the line types in the reference voltage setting circuit 52.
Assuming now that resistance dividing ratio of the variable resisters VR 1 to VR 3 is R 1 :R 2 and that a voltage of the negative power supply 53 is represented as EV, then the set reference voltage V s c is expressed as V s c ={R 1 /R 1 +R 2 }·E at the center of the screen 9. Also, the set reference voltage V s s is expressed as V s s ={R 1 /R 1 +R 2 }·(V x +V y +E)={R 1 /R 1 +R 2 }·(V x +V y )-{R 1 /R 1 +R 2 }·E on the peripheral portions of the upper, lower, right and left ends of the screen 9. In this equation, {R 1 /R 1 +R 2 }·(V x +V y ) represents the increased amount of the voltage at the peripheral portion of the screen 9.
If now the line type switching signal is supplied to the gate of the three-state circuit 55a as the decoded output of the decoder 54, then the reference voltage signals for fine and middle lines are not supplied to the amplifier 45 forming the comparing circuit but only the reference voltage signal for the bold line is supplied to the amplifier 45. This reference voltage corresponds to the bold line and the reference voltage corresponding to the peripheral portion of the screen 9 is compensated for as compared with that of the center portion of the screen 9. This reference voltage is compared with the detected signal from the monitor photodiode 36 of the laser diode 30 and a difference component thereof is supplied to the voltage-to-current converter circuit 46.
At the drawing speed at which the X-axis and Y-axis speed signals V x and V y are synthesized by the vector generator circuit 49 in a vector fashion, the PWM waveform of pulse width corresponding to this drawing speed is supplied to the voltage-to-current converter circuit 46 from the PWM controller circuit 47. In this voltage-to-current converter circuit 46, the reference voltage is modulated in level and compensated by the X-axis and Y-axis position signal voltages such that the reference voltage is increased on the peripheral portion of the screen 9. As a result, the level of the PWM waveform is raised in the peripheral portion of the screen 9 and lowered at the center portion thereof.
Since the liquid crystal display apparatus according to the first embodiment of the present invention is arranged and operated as described above, even if the line width is reduced on the peripheral portion of the screen 9 or nothing can be drawn on the screen 9 when the laser beam is not properly focused on the surface of the liquid crystal 24 due to lens characteristics, displacement of optical axis and so on or the temperature distribution of the liquid crystal cell heated in the constant temperature oven is not uniform, the above problems can be solved electrically by fine adjusting the variable resistors in the gain and balance adjusting circuit within the first and second absolute value generator circuits 162, 163. Hence, a line of a uniform line width can be drawn.
According to the liquid crystal display apparatus according to the first embodiment of the present invention, the line of uniform line width can be drawn on the whole surface of the screen by varying the laser power level of the laser beam source in response to the drawing position.
A second embodiment of the present invention will now be described with reference to FIG. 15 to FIGS. 19A, 19B, wherein like parts corresponding to those of the first embodiment are marked with the same references and therefore need not be described in detail.
Prior to describing the liquid crystal display apparatus according to the second embodiment of the present invention with reference to FIG. 17, data stored in the ROM 49 of this embodiment will be first described with reference to FIGS. 15 and 16.
Referring to FIG. 15, bold line data (address FF H ), middle line data (address BF H ), fine line data (address 7F H ) and drawing starting data (address 3F H ) are stored in the addresses of the ROM 49 in a divided form.
As shown in FIG. 15, data from the addresses A 0 to A 5 from the CPU 48 are supplied through an input driver 262 to a decoder 263 and the above-mentioned respective data stored in the ROM 49 are input through an output buffer 264 to a counter or the like of the PWM controller circuit 47 as data D 1 to D 7 , whereby the the PWM waveform signal is output from the PWM controller circuit 47.
A relation between the drawing start data output and a drawing speed (i.e., speed which results from synthesizing V x +V y in a vector fashion) is selected such that a straight line 265 in FIG. 16 representative of the drawing start ROM data is started from high level as compared with the straight line 154 and that the drawing start ROM data is higher in level than the drawing ROM data during a line segment except the maximum speed.
That is, the pulse width τ 2 of the PWM waveform signal is increased in response to the drawing speed as shown in FIG. 8B.
FIG. 17 of the accompanying drawings shows a block diagram of the laser driver unit according to the second embodiment of the present invention which is used to switch the ROM data to the drawing start ROM output. In FIG. 17, like parts corresponding to those of FIG. 6 are marked with the same references and therefore need not be described in detail. The laser driver unit in the second embodiment shown in FIG. 17 is different from that of FIG. 6 is that the laser drive signal LD 0 from the CPU 48 is supplied to a one-shot or monostable multivibrator (simply referred to as M.M in FIG. 17) 261 whose output LD 0 ' is supplied to the address terminal A 1 4 of the ROM 49.
That is, according to the second embodiment, the ROM data is switched to the drawing start data only during a very short period of time when the drawing is started, whereby the laser power of the laser beam emitted from the laser diode 30 is increased.
FIGS. 18A and 18B of the accompanying drawings show a waveform of the laser drive signal LD 0 from the CPU 48 and a waveform of the output LD 0 ' from the monostable multivibrator 261. As shown in FIG. 18A, the CPU 48 derives the laser drive signal LD 0 which goes to "L" (low) level at the same time when the drawing is started and which goes to "H" (high) level at the completion of the drawing. At the same time when the drawing is started, the monostable multivibrator 261 is set to "L" (low) level during a predetermined period (e.g., 100 m sec) so that the address of the ROM 49 is switched to 3F H . Therefore, the data stored in this address is output from the output buffer 264 (see FIG. 15) so that the pulse width of the PWM waveform is changed from τ 1 of FIG. 8A to τ 2 of, for example, FIG. 8B. Thus, the laser diode 30 can generate a laser beam of large laser power at the beginning of the drawing.
Unlike the prior art in which the non-recording portion 155 is produced and the top of the writing start portion 156 is reduced in line width in the beginning of the drawing as shown in FIG. 19A so that only a line having a length of L 1 >L 3 is drawn when the line having the predetermined length L 1 and predetermined width W is drawn, according to the liquid crystal display apparatus of the second embodiment of the present invention, although the top of the drawing start portion 156 is rounded, the line having the predetermined length and width L 1 and W can be drawn correctly as shown in FIG. 19B.
Furthermore, since the modulation degree of the PWM is obtained only by switching the output data in the ROM 49, the degree of modulation can be varied with great ease so that the line of uniform line width can be drawn with ease.
According to the liquid crystal display apparatus of the second embodiment of the present invention, when a predetermined graphic pattern is drawn by the irradiation of a laser beam on the liquid crystal cell, only by increasing the laser power density of the laser beam in the beginning of the drawing, the line of the predetermined dimension, i.e., uniform line width can be drawn.
The liquid crystal display apparatus according to a third embodiment of the present invention will be described below with reference to FIGS. 20 and 21. In FIGS. 20 and 21, like parts identical to those of FIGS. 1 and 3 are marked with the same references and therefore need not be described in detail.
Prior to describing the structure of the laser block 1 according to the third embodiment of the present invention with reference to FIG. 21, the liquid crystal display apparatus according to the third embodiment of the present invention will be described below with reference to FIG. 20.
FIG. 20 of the accompanying drawings shows the whole structure of the liquid crystal display apparatus according to the third embodiment of the present invention.
As shown in FIG. 20, a host computer 345 is a CPU (central processing unit) and operates to control a signal generator circuit 346, from which there are generated various signals.
The signal generator circuit 346 generates the Y-axis and X-axis scanning signals X and Y to the galvanoscanner mirrors 3a, 3b to control the writing laser beam 6, thereby drawing a graphic pattern of a predetermined locus or the like on the liquid crystal cell 7.
Further, the laser diode 30 disposed within the laser block 1 is controlled in a PWM fashion by means of a voltage-to-current converter circuit 347 so that the laser power thereof is controlled. The voltage-to-current converter circuit 347 is supplied with a comparing voltage from a comparator circuit 348. The comparator circuit 348 is supplied at its one input terminal with a monitor current from the monitor photodiode 36 through a current-to-voltage converter circuit 49 and is also supplied at another input terminal with a reference voltage. Then, the comparator circuit 348 compares the monitor current with the reference voltage to thereby control the laser diode 36 base on the compared output in an APC fashion. Thus, the power source voltage of the laser diode 30 is stabilized. Of course, the output or the like from the detection photodiode 42 disposed within the laser block 1 is also supplied to the signal generator circuit 346 and the CPU 345, though not shown. A rest of the structure of this optical system is similar to that of the above embodiment.
FIG. 21 of the accompanying drawings shows the optical system disposed within the laser block 1 according to the third embodiment of the present invention.
The polarizing beam splitter 34 which is used in this embodiment and which is the same as that shown in FIG. 3 is arranged such that it separates a part of the writing laser beam 6 emitted from the laser diode 30 and passes the rest of the writing laser beam 6 therethrough, while it does not separate a detection reflected-back beam. Therefore, as shogun in FIG. 21, a second polarizing beam splitter 344 is disposed distant from the first polarizing beam splitter 34 on the optical path by a predetermined spacing.
The second polarizing beam splitter 344 passes the writing laser beam 6 passed through the first polarizing beam splitter 34 and reflects the reflected-back beam 39 reflected on the liquid crystal cell 7.
Accordingly, the monitor collimator lens 35 and the monitor photodiode 36 are disposed on an optical path of the reflected light of the writing laser beam 6 in an opposing relation to the first polarizing beam splitter 34.
Similarly, the collimator lens 41 and the position detection photodiode 42 are disposed on the optical path of the reflected light of the writing laser beam 6 in an opposing relation to the second polarizing beam splitter 344. A rest of the structure of this optical system is substantially the same as that in FIG. 3.
Operation of the liquid crystal display device according to the third embodiment of the present invention will be described.
As shown in FIG. 21, the writing laser beam 6 of the linear polarized P-component emitted from the laser diode 30 is collimated by the collimator lens 31 and corrected in shape by the anamorphic prism 32 from ellipse to circle.
Then, the linear polarized P-component is rotated 90 degrees by the half-wave plate 33 and a part thereof (less that several % is converted into the linear polarized S-component which is then introduced into the first polarizing beam splitter 34. The linear polarized P-component is passed through the first polarizing beam splitter 34, whereas a part of the S-component is reflected on the first polarizing beam splitter 34 and then introduced through the collimator lens 35 into the monitor photodiode 36. The laser beam introduced into the photodiode 36 is converted into an electrical signal. As shown in FIG. 20, this electrical signal is fed through the current-to-voltage converter circuit 349, the comparator circuit 348 and the voltage-to-current converter circuit 347 back to the laser diode 30 to effect the APC so that the output of the laser diode 30 is made constant.
The laser beam 6 of the linear polarized P-component passed through the first polarizing beam splitter 34 is passed through the second polarizing beam splitter 344 as it is and introduced into the quarter-wave plate 37. The linear polarized P-component is rotated 45 degrees by the quarter-wave plate 37 and converted into a circular polarized component. This circular polarized component scans the liquid crystal cell 7 via the galvanoscanner mirrors 3a, 3b to thereby draw a predetermined graphic pattern. An instruction of this drawing of the graphic pattern is issued from the input operation unit side of the CPU 345 shown in FIG. 20.
Although the graphic pattern thus drawn is projected on to the screen 9, the laser beam whose power does not contribute the drawing is returned through the same optical path into the laser block 1 as the reflected-back beam 39. At that time, since the reflected-back beam 39, which is passed through the quarter-wave plate 37 again, it is rotated 45 degrees, i.e., rotated 90 degrees in total by the quarter-wave plate 37. Thus, the circular polarized component is converted into the linear polarized S-component. Then, the S-component is reflected on the second polarizing beam splitter 344 and introduced through the position detection collimator lens 41 into the position detection photodiode 42, in which it is converted into the position detection signal.
The reflected-back beam 39 is not wholly absorbed on the surface of the photodiode 42 and then it is partly diffused thereon. In this case, since the monitor photodiode 36 that monitors the output of the laser diode 30 to effect the APC on the laser diode 30 is not disposed on the optical path of the scattering laser beam 43, the monitoring by the monitor photodiode 36 is not affected by the scattering beam 43.
Unlike the prior art in which the reflected-back beam 39 of the writing laser beam 6 drawn on the liquid crystal surface of the liquid crystal cell 7 is not always constant and fluctuated in level, according to the liquid crystal display apparatus of the third embodiment of the present invention, the reflected-back beam 39 whose level is fluctuated can be avoid from being introduced into the photodiode 36, thereby removing the factor with which the level of the reflected-back beam 39 is fluctuated when the laser power of the laser diode 30 is controlled. Therefore, the laser power of the laser diode 30 can be stabilized when the liquid crystal display apparatus is driven.
While the two polarizing beam splitters 34 and 344 are used as described above, the first polarizing beam splitter 34 may be formed of an ordinary beam splitter or may be replaced with a dichroic mirror or the like.
According to the third embodiment of the liquid crystal display apparatus of the present invention, when the laser output from the laser diode is controlled in response to the drawing speed, the scattering beam whose output level is fluctuated is prevented from being introduced into the photodiode that operates to monitor the output of the laser diode, thereby operating the APC circuit stably. Therefore, the output of the laser diode can be kept constant so that the line width of the line to be drawn can be kept uniform.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments and that various changes and modifications could be effected therein by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims. | A liquid crystal display apparatus comprises a laser beam source for emitting a laser beam, a liquid crystal cell for providing an image by means of the effect of the laser beam heating and which contains a liquid crystal layer positioned between a pair of substrates, a scanning device for scanning the laser beam to the liquid crystal layer to thereby produce a line drawing thereon, and a modulation device for modulating a line width of the line drawing so as to keep a uniform line width. | 6 |
FIELD OF THE INVENTION
[0001] This invention relates in general to a method and apparatus for the operation of a cell stack assembly during subfreezing temperatures, and deals more particularly with a method and apparatus by which cell stack assemblies may avoid structural damage to their constituent parts when experiencing harsh environmental conditions, especially during times of operational shut-down or start-up.
BACKGROUND OF THE INVENTION
[0002] Electrochemical fuel cell assemblies are known for their ability to produce electricity and a subsequent reaction product through the reaction of a fuel being provided to an anode and an oxidant being provided to a cathode, thereby generating a potential between these electrodes. Such fuel cell assemblies are very useful and sought after due to their high efficiency, as compared to internal combustion fuel systems and the like. Fuel cell assemblies are additionally advantageous due to the environmentally friendly chemical reaction by-products that are produced, such as water. In order to control the temperature within the fuel cell assembly, a coolant is provided to the fuel cell assembly. The coolant, typically water, is circulated throughout the fuel cell assembly via a configuration of coolant channels. The use of water within fuel cell assemblies makes them particularly sensitive to freezing temperatures.
[0003] Electrochemical fuel cell assemblies typically employ a hydrogen-rich gas as the fuel and oxygen as an oxidant where, as noted above, the reaction by-product is water. Such fuel cell assemblies may employ a membrane consisting of a solid polymer electrolyte, or ion exchange membrane, having a catalyst layer formed thereon so as to promote the desired electrochemical reaction. The catalyzed membrane is disposed between two electrode substrates formed of porous, electrically conductive sheet material—typically carbon fiber paper. The ion exchange membrane is also known as a proton exchange membrane (hereinafter PEM), such as sold by DuPont under the trade name NAFIONTM.
[0004] In operation, hydrogen fuel permeates the porous electrode substrate material of the anode and reacts at the catalyst layer to form hydrogen ions and electrons. The hydrogen ions migrate through the membrane to the cathode and the electrons flow through an external circuit to the cathode. At the cathode, the oxygen-containing gas supply also permeates through the porous electrode substrate material and reacts with the hydrogen ions, and the electrons from the anode at the catalyst layer, to form the by-product water. Not only does the ion exchange membrane facilitate the migration of these hydrogen ions from the anode to the cathode, but the ion exchange membrane also acts to isolate the hydrogen fuel from the oxygen-containing gas oxidant. The reactions taking place at the anode and cathode catalyst layers may be represented by the equations:
Anode reaction: H 2 →2H + +2 e −
Cathode reaction: ½O 2 +2H + +2 e − →H 2 O
[0005] Conventional PEM fuels cells have the membrane electrode assembly, comprised of the PEM and the electrode substrates, positioned between two gas-impermeable, electrically conductive plates, referred to as the anode and cathode plates. The plates are typically formed from graphite, a graphite-polymer composite, or the like. The plates act as a structural support for the two porous, electrically conductive electrodes, as well as serving as current collectors and providing the means for carrying the fuel and oxidant to the anode and cathode, respectively. They are also utilized for carrying away the reactant by-product water during operation of the fuel cell.
[0006] When flow channels are formed within these plates for the purposes of circulating either fuel or oxidant in the anode and cathode plates, they are referred to as fluid flow field plates. These plates may also function as water transfer plates in certain fuel cell configurations and usually contain integral coolant passages, thereby also serving as cooler plates in addition to their well known water management functions. When the fluid flow field plates simply overlay channels formed in the anode and cathode porous material, they are referred to as separator plates. Moreover, the fluid flow field plates may have formed therein reactant feed manifolds, which are utilized for supplying fuel to the anode flow channels or, alternatively, oxidant to the cathode flow channels. They may also have corresponding exhaust manifolds to direct unreacted components of the fuel and oxidant streams, and any water generated as a by-product, from the fuel cell. Alternatively, the manifolds may be external to the fuel cell itself, as shown in commonly assigned U.S. Pat. No. 3,994,748 issued to Kunz et al. and incorporated herein by reference in its entirety.
[0007] The catalyst layer in a fuel cell assembly is typically a carbon supported platinum or platinum alloy, although other noble metals or noble metal alloys may be utilized. Multiple electrically connected fuel cell assemblies, consisting of two or more anode plate/membrane/cathode plate combinations, may be referred to as a cell stack assembly. A cell stack assembly is typically electrically connected in series.
[0008] Recent efforts at producing the fuel for fuel cell assemblies have focused on utilizing a hydrogen-rich gas stream produced from the chemical conversion of hydrocarbon fuels, such as methane, natural gas, gasoline or the like. This process produces a hydrogen-rich gas stream efficiently as possible, thereby ensuring that a minimal amount of carbon monoxide and other undesirable chemical byproducts are produced. This conversion of hydrocarbons is generally accomplished through the use of a steam reformer and related fuel processing apparatus well known in the art.
[0009] As discussed previously, the anode and cathode plates may be provided with coolant channels for the circulation of a water coolant, as well as the wicking and carrying away of water produced as a by-product of the fuel cell assembly operation. The water so collected and circulated through a fuel cell assembly in the coolant channels is susceptible to freezing below 32° F. (0° C.) and may therefore damage and impair the operation of the fuel cell assembly as the water expands when it freezes. It is therefore necessary to provide a method and apparatus, which may protect the fuel cell assembly during times of harsh environmental conditions.
[0010] U.S. Pat. No. 5,798,186 issued to Fletcher et al. on Aug. 25, 1998 discloses various electrical heating configurations for directly and indirectly thawing a fuel cell stack, which has frozen. Additionally, mention is made as to having compliant or compressible devices located within the stack manifold headers to accommodate the expansion of freezing water within the fuel cell stack. Such a system, localized only within the stack manifold headers, will not fully protect the entirety of the fuel cell stack or coolant channels from the effects of freezing and expanding coolant.
[0011] In particular, there are those situations where the start-up of the fuel cell assembly is desired after a time of inactivity in subfreezing environmental conditions. In such cases it has been discovered that attempting to circulate coolant through the coolant channels, in order to alleviate the freezing conditions within the fuel cell assembly, does not result in acceptable performance characteristics. When, for example, water is utilized as the coolant, the temperature of the fuel cell assembly typically causes localized freezing at the input to the small-dimensioned coolant channels, thereby partially blocking circulation therethrough and unduly lengthening the time required for start-up. When non-porous coolant channels or plates are utilized in conjunction with an antifreeze solution coolant, similar problems exist due the high viscosity of the antifreeze solution at low temperatures, again lengthening the time required for start-up.
[0012] With the forgoing problems and concerns in mind, it is the general object of the present invention to provide a fuel cell assembly with a method and apparatus which overcomes the above-described drawbacks even in times of subfreezing temperatures.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide a method and apparatus for the operation of a cell stack assembly during subfreezing temperatures.
[0014] It is another object of the present invention to provide a shut-down procedure for a cell stack assembly which protects the cell stack assembly even during times of subfreezing temperatures.
[0015] It is another object of the present invention to provide a start-up procedure for a cell stack assembly which protects the cell stack assembly even during times of subfreezing temperatures.
[0016] It is another object of the present invention to utilize a thermally insulating coolant accumulator to assist in quickly raising the temperature of the cell stack assembly.
[0017] According to one embodiment of the present invention a coolant system is proposed for a cell stack assembly which includes a coolant pump for circulating a coolant and coolant channels in fluid communication with a coolant inlet manifold and a coolant exhaust manifold. The coolant system comprises a coolant exhaust conduit in fluid communication with the coolant exhaust manifold and the coolant pump, the coolant exhaust conduit enabling transportation of exhausted coolant away from the coolant exhaust manifold. A coolant return conduit is provided to be in fluid communication with the coolant inlet manifold and the coolant pump, the coolant return conduit enabling transportation of the coolant to the coolant inlet manifold. The coolant system further includes a bypass conduit in fluid communication with the coolant exhaust conduit and the coolant return conduit, while a bleed valve is in fluid communication with the coolant exhaust conduit and a gaseous stream. Operation of the bleed valve enables venting of the coolant from the coolant channels, and through said bypass conduit.
[0018] These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is a schematic illustration of a coolant system, according to one embodiment of the present invention.
[0020] [0020]FIG. 2 is a flow diagram illustrating the operation of the coolant system in FIG. 1 during a shut-down procedure.
[0021] [0021]FIG. 3 is a flow diagram illustrating the operation of the coolant system in FIG. 1 during a start-up procedure.
[0022] [0022]FIG. 4 is a schematic illustration of a coolant system, according to another embodiment of the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] [0023]FIG. 1 illustrates a coolant system 100 , according to one embodiment of the present invention which may be operated to protect a cell stack assembly 102 from the detrimental effects of subfreezing temperatures during start-up and shut-down procedures. As depicted in FIG. 1, the cell stack assembly (hereinafter ‘CSA’) 102 is comprised of a plurality of fuel cell assemblies 103 in electrical communication with one another. The fuel cell assemblies may each employ an ion exchange membrane consisting of a solid polymer electrolyte disposed between an anode electrode substrate and a cathode electrode substrate. An anode plate 107 and a cathode plate 109 support reactant fuel channels 111 and reactant oxidant channels 113 , respectively. The ion exchange membrane may be a proton exchange membrane (PEM) 105 comprising a polymer film approximately 0.001 inch thick. The cathode and the anode electrode substrates are typically formed of porous, electrically conductive sheet material—typically carbon fiber paper having a Teflon® coating. Coolant channels 104 are formed within typically porous coolant plates, or the like, in each of these PEM fuel cell assemblies 103 , wherein water is typically utilized as the coolant circulating through the coolant channels 104 .
[0024] While PEM fuel cell assemblies have been described, the present invention is not limited in this regard as other membranes and electrode materials may be alternatively utilized, providing they allow for the necessary flow of reactant and by-product molecules, ions and electrons. In particular, fuel cell assemblies utilizing an antifreeze solution circulating through coolant channels in non-porous coolant plates may also be employed without departing from the broader aspects of the present invention.
[0025] Still in reference to FIG. 1, a coolant inlet manifold 106 substantially evenly distributes a coolant to a plurality of coolant channels 104 , which are designed to uniformly circulate the coolant about each of the fuel cell assemblies 103 comprising the cell stack assembly 102 . The coolant channels 104 are themselves exhausted to a coolant exhaust manifold 108 after the coolant has circulated through the cell stack assembly 102 . Exhausted coolant leaves the coolant manifold 108 via a coolant exhaust conduit 110 under the dynamic force of a coolant pump 112 . The coolant is then directed to an accumulator 114 prior to being shunted, with varying ratios, to a heat exchanger 116 and an instantaneous heater 118 , as will be described in more detail later. A coolant return conduit 120 is subsequently provided to funnel the coolant once again to the coolant inlet manifold 106 .
[0026] When PEM fuel cell assemblies having porous coolant channels or plates are utilized in the cell stack assembly 102 , the coolant circulating through the various components of FIG. 1 is maintained at a subambient pressure by the coolant pump 112 and a coolant inlet pressure control valve 122 . By maintaining the coolant at subambient pressures while adapting the reactants flows to be above ambient pressures, the accumulation of liquid coolant in either the fuel or the oxidant reactant streams is effectively avoided. Moreover, the inclusion of the heat exchanger 116 provides a known means to remove the heat absorbed by the circulating coolant prior to the coolant being directed back to the cell stack assembly 102 .
[0027] As described above, the coolant system 100 of FIG. 1 thereby provides for the continuous supply and circulation of a coolant, typically water, throughout the cell stack assembly 102 during active operation thereof. While it should be readily apparent that utilizing a water coolant within the cell stack assembly 102 is beneficial for the purposes of water and thermal management, problems arise when the cell stack assembly 102 experiences temperatures at or below the freezing point of water; that is, temperatures at or below 32° F. (0° C.). During times when the cell stack assembly 102 experiences such temperatures, the water contained within the cell stack assembly 102 begins to freeze and expand, and may possibly cause damage to components of cell stack assembly 102 . It would therefore be very beneficial to equip the cell stack assembly 102 with an apparatus which compensates for the freezing of the water coolant and assuredly prevents corresponding damage during times of shut-down and start-up.
[0028] It is therefore an important aspect of the present invention to provide a method and apparatus for safely executing a shut down procedure for the cell stack assembly 102 during times of subfreezing temperatures. In known practices, when shut-down of the cell stack assembly 102 is ordered, the water coolant is allowed to drain from the cell stack assembly 102 under the force of gravity. In effect, this means that the pressure differential between the coolant supply and the reactant streams is no longer maintained by the coolant pump 112 and the pressure control valve 122 , hence, the coolant will slump down into the reactant flow fields leaving a portion of the cell stack assembly 102 immersed in a mixture of water, fuel and oxidant. This condition may last indefinitely during the shut-down period or, rather, may affect the cell stack assembly 102 for a shorter time. In either case, damage may be effected upon the cell stack assembly 102 during the time that the water coolant is allowed to pool within the cell stack assembly 102 in an environment of subfreezing temperatures.
[0029] [0029]FIG. 2 illustrates a shut-down procedure 200 according to one embodiment of the present invention which avoids the above-described drawbacks and ensures that a shut-down operation of the cell stack assembly 102 may be accomplished during subfreezing temperatures without harm to the cell stack assembly 102 . The shut-down procedure 200 described herein is preferably begun after the electrical load has been removed from the cell stack assembly 102 , and after the reactant flows have been stopped and any corrosion control steps have been completed.
[0030] The shut-down procedure 200 utilizes a shut-down bypass conduit 124 and an influx of venting air, or the like. With reference to FIGS. 1 and 2 in combination, the shut-down procedure 200 according to the present invention begins in step 202 by initiating, either manually or automatically, a shut-down sequence. As indicated in step 202 , the coolant pump 112 continues to operate after shut-down has been initiated in order to maintain the subambient pressure within the coolant conduits. In this manner, the present invention avoids the previously mentioned problem of the coolant slumping in the reactant and coolant flow fields.
[0031] Returning to step 204 of the shut-down procedure 200 of FIG. 2, a shutdown valve 126 is opened in order to divert a substantial portion of a coolant stream through the shut-down bypass conduit 124 . A coolant exit valve 128 , situated along the coolant exhaust conduit 110 , is then closed in subsequent step 206 in order to prohibit the flow of coolant through the cell stack assembly 102 . In step 208 the cell stack assembly 102 is isolated from any additional supply of coolant by closing the pressure control valve 122 , while step 210 operates to open a bleed valve 130 , thereby placing the coolant system 100 in communication with an air supply. In the preferred embodiment of the present invention, the bleed valve 130 is in communication with an external ambient air supply or atmosphere and serves to vent the coolant system by allowing ambient air to be bled into the coolant conduits and flow fields. As will be appreciated, the venting action is enabled by the continued operation of the coolant pump 112 which maintains a vacuum on the coolant conduits and flow fields.
[0032] While the present invention has been described as venting the coolant conduits and flow fields with an ambient air supply, alternative methods for evacuating the coolant from the coolant conduits and flow fields may be employed without departing from the broader aspects of the present invention. A pressurized source of air may alternatively be placed in communication with the coolant conduits and flow fields upon the opening of the bleed valve 130 , thus purging the coolant conduits and flow fields of any remaining coolant.
[0033] As discussed above, by closing the various valves of the coolant system 100 as described above, the air which is drawn through the bleed valve 130 serves to vent the coolant exhaust manifold 108 , the coolant channels 104 and the coolant inlet manifold 106 of any coolant remaining therein. The vented coolant is directed through the shut-down bypass conduit 124 and eventually deposited into the accumulator 114 , leaving the reactant and coolant channels in the cell stack assembly 102 free of substantially all of the water coolant, although some water may remain within the porous water transport plates.
[0034] During the venting process, it is determined in step 212 whether there still remains any coolant in the reactant and coolant channels in the cell stack assembly 102 . As long as coolant is detected, the purging process continues as described above. When it is determined that substantially no coolant remains in the cell stack assembly 102 , the shut-down bypass conduit 124 is closed and the coolant pump 112 is disabled in step 214 . The bleed valve 130 is subsequently closed in step 216 to end the purging process of the shut-down procedure 200 . As will be appreciated, various sensor assemblies may be situated in the coolant exhaust manifold 108 , the coolant inlet manifold 106 , or the coolant return conduit 120 to determine if there remains any excess water coolant in the cell stack assembly 102 , in accordance with step 212 .
[0035] The effect of the shut-down procedure 200 is to remove substantially all of the coolant from the cell stack assembly 102 , thereby preventing the detrimental expansion of the coolant within the cell stack assembly 102 during the period of time following shut-down in subfreezing temperatures.
[0036] After shut-down, the cell stack assembly 102 faces the related challenge of implementing a start-up command in subfreezing temperatures. For practical concerns, including economics and reliability, it is important that the cell stack assembly 102 begin producing electricity as soon as possible after receiving a start-up command. In addition, it is operationally critical that the cell stack assembly 102 be capable of quickly circulating the coolant and reactant flows immediately after start-up is initiated, as damage to the cell stack assembly 102 may occur should a significant time lag occur between these two events. It is therefore an important aspect of the present invention to provide a method and apparatus for a start-up procedure of the cell stack assembly 102 during times of subfreezing temperatures.
[0037] [0037]FIG. 3 illustrates a start-up procedure 300 for ensuring that a start-up operation of the cell stack assembly 102 may be accomplished during subfreezing temperatures by utilizing a start-up bypass conduit 132 . It has been discovered that by permitting a warmed coolant to flow through the inlet and exhaust coolant manifolds, 106 and 108 respectively, it is possible to quickly raise the temperature of the cell stack assembly 102 by conduction, without the need for significant flow through the coolant channels 104 themselves. As mentioned previously, by substantially avoiding the coolant channels 104 during the initial start-up of a subfreezing cell stack assembly, the formation of frozen blockages in the coolant channels, and hence possible harm to the cell stack assembly 102 as a whole, may be effectively avoided.
[0038] With reference to FIGS. 1 and 3 in combination, the start-up procedure 300 according to the present invention begins in step 302 by initiating, either manually or automatically, a start-up sequence. The start-up sequence in step 302 includes activating the coolant pump 112 , as well as ensuring that the shutdown valve 126 is closed and the pressure control valve 122 is open. In step 304 a bypass of the cell stack assembly 102 is accomplished by opening a start-up valve 136 located along the start-up bypass conduit 132 . In this manner, coolant which is provided to the coolant inlet manifold 106 is substantially entirely directed through the start-up bypass conduit 132 and back into the coolant exhaust manifold 108 , thereby initially avoiding the coolant channels 104 .
[0039] In step 306 the heat exchanger 116 is bypassed by opening the heat bypass valve 138 situated along the heat bypass conduit 140 . A thermostat-valve assembly 115 is utilized to ensure that no coolant is permitted to flow through the heat exchanger 116 until start-up of the cell stack assembly 102 has been accomplished and/or the coolant temperature exceeds a predetermined temperature.
[0040] Subsequent to opening the heat bypass valve 138 of FIG. 1, the coolant circulated by the pump 112 will be directed through the instantaneous heater 118 , which is activated in step 308 , for quickly raising the temperature of the coolant provided to the coolant manifolds, 106 and 108 , respectively. As discussed above, as the heated coolant is circulated through both the coolant inlet manifold 106 and the coolant exhaust manifold 108 the cell stack assembly 102 will quickly become heated due to heat conduction stemming from the coolant manifolds, 106 and 108 . A temperature sensor 142 monitors the temperature of the cell stack assembly 102 , in step 310 , to determine if the cell stack assembly 102 has risen above a predetermined temperature T. Once the cell stack assembly 102 has risen above the predetermined temperature T, step 312 of the start-up procedure 300 closes the start-up valve 136 and the heat bypass valve 138 , as well as shutting down the instantaneous heater 118 .
[0041] It will be readily appreciated that the predetermined temperature T is preferably set as a temperature threshold which would ensure that coolant provided to the coolant channels 104 will not freeze and block the coolant channels 104 . Most preferably, the predetermined temperature T is set at approximately 32° F. or higher. Moreover, the temperature sensor 142 may be oriented at various locations within the cell stack assembly 102 , however, orientation at a center-most location is preferable to ensure that warming of the entirety of the cell stack assembly has been substantially accomplished.
[0042] As described herein, the start-up procedure 300 is equally applicable to PEM fuel cells which utilize a water coolant with porous water transport plates, as well as for those fuel cells which utilize an antifreeze coolant having nonporous water transport plates.
[0043] Yet another important feature of the coolant system 100 , as depicted in FIG. 1, is the utilization of the accumulator 114 to assist in start-up procedures. In accordance with the present invention, the accumulator 114 is designed to be insulated so as to keep the coolant deposited therein at elevated temperatures, thereby assisting the start-up procedure 300 shown in FIG. 3. It will be readily appreciated that the accumulator 114 may be a thermos-type structure having thermally reflective components, including multi-walled structures, or any alternative design provided that the stored coolant retains significant thermal energy for periods extending to several days or more.
[0044] [0044]FIG. 4 illustrates a coolant system 400 according to another embodiment of the present invention. The coolant system 400 may be utilized to quickly raise the temperature of a cell stack assembly 410 by heating the coolant stream provided to the cell stack assembly 410 . As depicted in FIG. 4, a burner 412 combusts a residual fuel source, exhausted from unillustrated reactant fuel flow fields of the cell stack assembly 410 via a fuel exhaust conduit 411 . This heated burner exhaust is subsequently exhausted into a tube portion 414 of a shell and tube heat exchanger 420 . In conjunction with the heated burner exhaust being fed through the tube portion 414 , a shell 416 accepts a coolant stream therein so as to promote a heat exchange between the burner exhaust and the coolant stream. The newly heated coolant stream is subsequently introduced into the cell stack assembly 410 , resulting in an increased rate of warming for the cell stack assembly 410 .
[0045] To further increase the rate of heating the cell stack assembly 410 , the present invention further contemplates channeling the heated burner exhaust, via heat conduit 418 , to the anode and/or cathode flow fields of the cell stack assembly 410 . The present invention also contemplates incorporating the coolant system 400 of FIG. 4 into the coolant system 100 of FIG. 1, without departing from the broader aspects of the present invention.
[0046] While the present invention describes combusting residual, exhausted reactant fuel in the burner 412 , the present invention is not so limited as the burner 412 may be supplied with its own fuel supply without departing from the broader aspects of the present invention.
[0047] It is a major aspect of the present invention, therefore, to provide a coolant system for a cell stack assembly which not only provides protection against the destructive effects of subfreezing temperatures during shut-down and cell stack inactivity, but also operates to quickly raise the cell stack assembly above freezing temperatures during a start-up procedure.
[0048] While the invention had been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims. | A coolant system is proposed for addressing temperature concerns during start-up and shut-down of a cell stack assembly. The coolant system comprises a coolant exhaust conduit in fluid communication with a coolant exhaust manifold and a coolant pump, the coolant exhaust conduit enabling transportation of exhausted coolant away from a coolant exhaust manifold. A coolant return conduit is provided to be in fluid communication with a coolant inlet manifold and a coolant pump, the coolant return conduit enabling transportation of the coolant to the coolant inlet manifold. The coolant system further includes a bypass conduit in fluid communication with the coolant exhaust conduit and the coolant return conduit, while a bleed valve is in fluid communication with the coolant exhaust conduit and a gaseous stream. Operation of the bleed valve enables venting of the coolant from the coolant channels, and through said bypass conduit. | 7 |
BACKGROUND OF THE INVENTION
The invention concerns an analog-digital converter for the evaluation of the output signal of an optoelectronic sensor element wherein an inverter is provided having a switching transistor with a series connected load element, and a further transistor is provided which connects the sensor element to an input of the inverter.
Such an analog-digital converter is described in German patent application No. P 2,838,647.2 corresponding to U.S. application Ser. No. 069,788. It there consists of a converter, the input of which is connected on the one side via a series connection of two switching transistors with a supply voltage source, and on the other side via a third switching transistor with the output of an optoelectronic sensor element. When the charge which is optically generated in the sensor element within an integration time determined by the third switching transistor has attained a predetermined reference value, then the converter proceeds into a switching state in which at its output, a logic signal "1" can be obtained. In the case of non-attainment of the reference value, the converter remains in a state in which the logic output signal "0" is present. The converter and one of the two switching transistors which lie in series represent circuit parts of a shift register stage which is individually associated with the sensor element. An analog digital converter for the evaluation of the analog output signals of a linear image sensor is further referred to in the prospectus 77144 of the firm Reticon Corp., Sunnyvale, Calif., wherein the "Model LC 600 Digital Line Scan Camera" is specified. If one of the output signals of the consecutively scanned or interrogated sensor elements exceeds a predetermined threshold value, then a logic "1" is released via the converter. The next following output signal of a sensor element which does not attain the threshold value, on the other hand, results in the switchover of the converter to an output signal which corresponds to a logic "0."
SUMMARY OF THE INVENTION
An object of the invention is to provide an analog-digital converter of the kind described above which permits a very precise digitalization of the analog sensor signals to a large extent independently of parameter fluctuations of the converter established by the manufacturer. This problem is solved in the analog-digital converter system of the invention, by connecting the inverter input with a reset transistor which connects to a constant voltage. The transistor connecting the sensor element with the input of the inverter is designed as a transistor defining a potential barrier.
An advantage which is attainable with the invention is that parameter or characteristic tolerances of the converter do not influence the digitalization. Also tolerances of the cutoff voltage of the potential barrier defining transistor are compensated to a large extent since this transistor is part of a circuit for resetting the sensor element as well as a part of a circuit for the digital evaluation of the analog sensor signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a circuit diagram of a preferred embodiment of the analog-digital converter of the invention;
FIG. 2 shows the design of a circuit portion of FIG. 1;
FIG. 3 shows voltage-time diagrams for explaining operation of FIGS. 1 and 2;
FIG. 4 shows an alternative embodiment for the circuit of FIG. 2;
FIG. 5 shows a second embodiment of the circuit of FIG. 2; and
FIG. 6 shows a schematic representation of a circuit in which the analog-digital converter according to the invention is employed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the principal circuit of an analog-digital converter which is connected with its input (circuit point E) to the output of an optoelectronic sensor element SE. In series with the input E is a source-drain path of a field effect transistor T1, via which input E is connected with the input E1 of an inverter. This consists of the series connection of a switching transistor T2 and a load element L, which in FIG. 1 is represented as a field effect transistor of the depletion type, the gate of which is connected with circuit point 1. The latter is connected to the output A of the analog-digital converter, whereas the terminal-side leads 2 and 3 of the series circuit T2, L are connected to a constant voltage U DD and a reference potential, for example, ground. Between points 2 and E1 is the source-drain path of a field effect transistor T3. This represents a reset transistor, the gate of which, for purposes of resetting circuit points E1 and E, is provided with a set potential with a clock pulse voltage φ1. The field effect transistor T1 represents a potential barrier defining transistor, the gate of which is provided with a pulse voltage φ2.
The sensor element consists of a photodiode FD which is parallel to the sensor output E, the capacitance of which is designated C SE . The input capacitance of the inverter T2, L, which is measured at circuit point E1, is drawn in FIG. 1 with a broken line and is provided with the reference symbol C E1 .
FIG. 2 shows a design of the converter whereby a circuit portion of FIG. 1 which contains the photodiode is integrated on a semiconductor body 4 of a first conductivity type, which consists for example of p-doped silicon. The photodiode FD consists of a region 6 of a conductivity type which is opposed to the first, and which is arranged at the interface 5 of the semiconductor body 4. The region of the semiconductor body 4 which is adjacent to region 6 is covered by a gate 7, which is separated from the interface 5 by means of a thin insulating layer 8, for example of SiO 2 . The gate 7 together with a drain region 9 of a conductivity type which is opposed to the first forms the field effect transistor T1. The region 9 simultaneously represents input E1 of the inverter T2, L, and especially also represents the source region of the reset transistor T3. The circuit parts T2, L and T3 are represented in correspondence to FIG. 1. The input capacitance C E1 of the inverter is indicated in the same manner as in the case of FIG. 1. In operation, the circuit points E1 and E are first reset to high positive potentials. This occurs by means of a clockpulse φ1 and a pulse φ2 (FIG. 3), which begin at time t1 and which switch the reset transistor T3 and the transistor T1 in each case into the conducting state. The amplitude of φ2 is smaller than that of φ1, so that the transistor T1 is operated in the saturation region, for which the relationship U E1 -U E is greater than A.sub.φ2 -U T -U E applies. Accordingly, the voltages U E1 and U E in each case appear at the circuit points E1 and E, while A.sub.φ2 signifies the amplitude of the pulse φ2, and U T signifies the cutoff voltage of transistor T1. In this case, the voltage U E is set by means of A.sub.φ2, for which the relationship U E =A.sub.φ2 -U T applies.
Under the influence of the voltages U E , φ2 and U E1 which during the resetting are at region 6, the gate 7 and the region 9, in each case potential values P6, P7 and P9 of the surface potential φ S are set. In FIG. 2 these are drawn in the direction of arrow 10. Accordingly, the upper end of 10 represents the reference potential P 0 , on which is located semiconductor body 4 in the case of supplying of a substrate voltage U 0 via lead 11.
Following this, A.sub.φ2 is lowered to a smaller value A1.sub.φ2, which lies between U E and the substrate voltage U 0 . If A1.sub.φ2 lies below the voltage U E +U T , then the transistor T1 blocks, whereby below the electrode 7 a potential barrier P71 forms. The potentials P6 and P9 remain uninfluenced by this, so that the curve P6, P71 and P9, which was also drawn in FIG. 2, results in φ S .
If now the photodiode is exposed through the aperture of a stop 35 with light beams L1, then the voltage U E (FIG. 3) and the potential P6 (FIG. 2) decrease. In the course of a predetermined integration time, the end of which is determined by the backward trailing edge 12 of φ2, the potential P6 can attain the potential barrier P71 in the case of sufficiently strong exposure (time t2). In FIG. 3, this time is determined such that U E has attained a threshold value U B . Following this, a part of the charge of the photodiode FD flows via P71 into region 9 and lowers P9 to a value P91, whereby voltage U E1 drops off strongly, as indicated in FIG. 3 with 13. The cutoff voltage of T2 is set such that it is attained by means of this voltage drop 13 of UE1. This has the result that T2 blocks and in the fact that the voltage U A at output A is switched over from the logic signal "0," which was present after the resetting and which corresponds approximately to the reference potential, to the logic signal "1" which corresponds approximately to the voltage U DD . If on the other hand within the predetermined integration time, because of a weak exposure of FD the potential barrier P71 is not attained by the potential P6, then this inverter switch-over does not occur. With this, a logic evaluation of the analog sensor signal corresponding to voltage U E at the end of the integration time (12) is provided by the digital output signals "1" and "0."
According to a variance from the manner of operation specified above, the pulse φ2 is not disconnected, so that in FIG. 3 the broken line 14 takes the place of flank 12. A time span t1 to t3 is determined, after which, even in the case of a weaker exposure (curve 15 in FIG. 3), the voltage U E has attained the threshold value U B , or respectively, the potential P6 has attained the potential barrier P71. The voltage drop of U E1 (compare 13') and the switchover of the voltage U A from "0" to "1" (compare 13a') then occur at time t3. Thus the time span t1 to t3 is a measurement for the strength of exposure of the photodiode FD. The voltage U A with the voltage rise 13a' can bring about, in the case of other similarly constructed analog-digital converters, an ending of the integration time, which can occur by means of a disconnection of the clock pulse φ2. In this case, this photodiode FD of the converter under consideration is preferably designed longitudinally extended such that it lies near a plurality of sensor elements which are associated to the other converters and thus takes on an optically generated charge which corresponds to the mean value of the exposure of all of these sensor elements. The time span t1 to t3 thereby corresponds to an integration time, within which a part of the further converters which are post-connected to more strongly exposed sensor elements are switched over to the output signal "1," whereas the remaining part of these converters which are associated to less strongly exposed sensor elements, are not switched over and further release the output signal "0."
By means of a large capacitance C SE of the sensor element SE in comparison to the input capacitance C E1 of the inverter T2, L, a change in potential from P9 to P91 which is relatively large is attained, so that the cutoff voltage U T of T2 is attained reliably even in the case of larger tolerances which are conditioned by the manufacture during the voltage drop 13.
According to another design of the analog-digital converter, the sensor element SE consists of MIS capacitor K which is represented in FIG. 4. This has a gate electrode 16 which is separated from the interface 5 of the semiconductor body 4 by means of the thin insulating layer 8. It is provided with a lead 17, which is connected with a constant voltage U K . Under the influence of U K , a space charge zone which is indicated with 17a forms under the gate electrode 16. The remaining circuit parts of FIG. 4 correspond to the circuit parts of FIG. 3 which are provided with the same reference symbols. The voltage U K must be selected such that a surface potential φ S forms under the gate electrode 16. This surface potential approaches the potential value P6 (FIG. 2) or exceeds it. The use of an MIS capacitor K as sensor element brings with it the advantage of a large capacitance C SE .
FIG. 5 shows a further design of the analog digital converter, whereby a photodiode FD according to FIG. 2 and a MIS capacitor K according to FIG. 4 are arranged next to one another on the thin insulating layer 8 and together form the sensor element SE. The circuit parts explained already with the use of FIGS. 2 and 4 are provided in FIG. 5 with the same reference symbols. The capacitance C SE is even greater according to FIG. 5 than according to FIG. 4.
The load element L can also consist of a field effect transistor of the depletion type. Its gate is then connected with the circuit point 2, in contrast to FIG. 1. Besides this, the gate of the field effect transistor which forms the load element L can be connected with a control line independently of its type. This control line is at a set potential or at a clock pulse voltage.
The circuit of the analog digital transducer according to the invention is at least partially monolithically integrated upon a doped semiconductor body with special advantage. In the case of a circuit construction in n-channel MOS engineering, the potential and voltages related to the substrate voltage U 0 are provided with a positive sign. In the case of p-channel MOS engineering, the voltages and potentials display negative signs, whereby also the conductivity types of the doped semiconductor regions are to be replaced by the opposing ones in each case.
FIG. 6 shows an advantageous use of an analog-digital converter according to the invention. This corresponds to the circuit portion designated W, which is connected to the output E of a sensor element SE11, for example, of a photodiode. The output A of the converter is connected via a transfer transistor T4, the gate of which is connected with a clock pulse voltage φ 3 and a drain or source with the input of a stage or step 21 of a shift register 20. The same kinds of sensor elements SE12 . . . SE1n and SE21 . . . SE2n are connected via the same kind of converters and transfer transistors with the stages 22 . . . 2n of the shift register 20 and the stages 21 . . . 3n of a shift register 30. The clock pulse inputs of the dynamic shift registers 20 and 30, which for example are designed in two-phase fashion, are provided with two clock pulse voltages φ 20 , φ 21 , which for reasons of simple representation are supplied via a line 40 which is drawn in with one pole. In series with the clock pulse inputs of the shift register 30 is a gate circuit 41, which displays a second output 42 connected via a line 43 with a counter 60. The outputs 20a and 30a of the steps 2n and 3n are on the one side connected via lines 20b and 30b with the inputs of the steps 21, or respectively 31, and on the other side are connected with the inputs 51 and 52 of a circuit 50, which determines the coincidence or lack of coincidence of the signals supplied to it via 20a and 30a. In a practical manner, the circuit 50 consists of an exclusive OR gate. The output of 50 is connected with a counter 54. Its output is connected via a memory 54a with the first input of a digital comparator 55, the second input of which is connected to a memory 56. On the other side, the output of the counter is connected with the memory 56 via an electronic switch 57 which is controlled via the output of the comparator 55. The output of the comparator 55 also influences the control input of an electronic switch 61, via which the output of the counter 60 is connected with a memory 62. An output 63 of the latter is finally connected with a device 64. The circuit parts 50 through 57 and 60 through 63 represent an evaluating circuit 70.
The sensor elements SE11 . . . SE1n, which together form a linear image sensor S1, and the sensor elements SE21 . . . SE2n, which together form a second linear image sensor S2, are exposed through the apertures of a stop with light beams L1, or respectively L2, which are derived separately from an object, the distance of which is to be determined. The separate images of this object on the planes of S1 and S2 are in such a surface related association to the image sensors S1 and S2 that these are directed at lines of the images that correspond to one another. For a predetermined distance of the object, for example, for the distance "infinite," S1 and S2 display the same brightness curves over the entire length of the sensor lines, so that at the outputs A, digitalized sensor signals S1n . . . S11 and S2n . . . S21 which are present in the case of a serial read-out in the sequence of the sensor elements, produce signal sequences which display a maximum correlation. If the distance of the object changes, then the segments of the lines which correspond to one another and which are directed to S1 and S2, are displaced. Accordingly, the correlation between the signal sequences mentioned become smaller. If one displaces the serially read-out digitalized signal sequences S1n . . . S11 and S2n . . . S21 in a step-like manner with respect to one another, then one can determine the displacement whereby the greatest correlation again occurs. This displacement is then a measurement for the actual distance of the object.
The shift registers 20 and 30 serve for the serial read-out of the sensor signals S1n . . . S11 and S2n . . . S21. In these shift registers the sensor signals in each case circulate under the influence of the clock pulse voltages φ 20 , φ 21 . After n clock pulse periods of φ 20 which belong to a first read-out cycle, in each case a complete signal cycle has occured so that the signal S1n which was present at the beginning of this cycle at the output 20a is again present at 20a also at the end of the same. Analogously to this, the signal S2n is present at the output 30a at the beginning and at the end of the first read-out cycle. The gate circuit 41 is blocked after this first read-out cycle for the duration of a clock pulse period φ 20 , φ 21 , so that the shift register 20 is connected further by one step, while 30 remains in the switching state which was attained at the end of the first cycle. For a second read-out cycle which follows the last named clock pulse period, the blocking of the gate circuit 41 signifies that one begins from a new mutual association of the sensor signals which are read-out serially at 20a and 30a, whereby the signals S1(n-1) and S2n, S1(n-2) and S2(n-1) and so on appear simultaneously at 20a and 30a. The second read-out cycle thus runs with a mutual displacement of the sensor signal sequences by one signal width. Each further read out cycle begins with a displacement of the sensor signal sequences with respect to one another which is increased in each case by one signal width. The circuit 50 releases a pulse for each coincidence of the logic signals "1" and/or the logic signals "0," which occur during a complete signal cycle in the shift registers 20 and 30, that is, during a complete read-out cycle. The counter 54 which is reset to 0 before the beginning of each read-out cycle, counts the number of these coincidences per cycle. If during a read out cycle in 54 a higher counter result is attained than in the preceding read out cycles, then a control signal is released via the comparator 55. This control signal in each case connects the gate circuit 57 and, via the line 58, the gate circuit 61 to be conducting.
In the case of each clock pulse period which is suppressed in the gate circuit 41, via 42 a count pulse P1, P2 and so on is derived which is supplied via the line 43 to the counter 60. By means of the function of the gate circuit 61, then, in each case with the occurence of a new count of the counter in the counter 50 which is larger than the largest count of the counter up until then, the momentary count of the counter is transferred from the counter 60 into the memory 62. This momentary count of the counter corresponds to the number of the count pulses P1, P2 . . . which has occured all together up to this point in time and thus corresponds to the number of the relative displacements which have occurred up until then of the signal sequences S1n . . . S11 and S2n . . . S21. After n read-out cycles, then a digital signal is stored in the memory 62. This signal corresponds to the number of the relative displacements between the signal sequences, by means of which a maximum correlation between the same is attained. This digital signal is supplied via the output 63 to the device 64 which can consist of an indicating device which displays the distance of the object. On the other hand, the device 64 can also consist of an adjustment device which, in dependence upon the signal supplied via the output 63, adjusts a lens system to such a distance with respect to a focal plane that an image of the object which is obtained via the lens system is focused onto the focal plane. Circuits of this kind can be employed above all in photographic or electronic cameras.
Although various minor modifications may be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of our contribution to the art. | An analog-digital converter is disclosed which monitors an output signal of an optoelectronic sensor element for the attainment or non-attainment of a reference charge, whereupon switchover occurs from one logic signal to the other. An exclusion to a large extent of parameter or characteristic tolerance effects on the result of the evaluation is achieved. For this purpose, the converter contains an inverter, the input of which is connected via a reset transistor with a constant voltage source and which is connected via a potential barrier defining transistor with the output of the sensor element. The converter shows no dependence upon fluctuations of the inverter. Applications include distance measuring devices, and photographic and electronic cameras. | 6 |
This is a division of application Ser. No. 08/570,806, filed on Dec. 12, 1995, now U.S. Pat. No. 5,690,738 which is a continuation of 08/157,923 filed on Nov. 24, 1993 and now abandoned.
FIELD OF INVENTION
This invention relates to apparatus for applying a film of liquid to the surface of a workpiece by contact transfer, and more particularly to a device of this type which utilizes one or more roller members for rotatably contacting the workpiece as it is advanced for manufacture or finishing and transferring a desired liquid to the surface of the workpiece during such contact. In addition, the invention relates to liquid applicators of this general type which provide accurately metered supply of the lubricant to be applied, such that the amount so applied is accurately controlled and regulated, preferably by use of a positive displacement pump for repeatably metering out and directing metered volumes of the liquid to the applicator members, whether rollers or otherwise. The apparatus may include oppositely disposed applicators such as rollers, which contact the workpiece from opposite sides, to apply the liquid to both such sides, and in this configuration the invention provides means by which a single such pump may be utilized to provide adjustable and relatively variable amounts of the liquid to each of two such opposed applicator members. Accordingly, the invention also relates to means for providing metered amounts of such liquid to the applicator members of contact-type liquid dispensers.
BACKGROUND
Many different industrial processes involve a continuously-advancing supply of material which is machined and processed in various ways to produce finished products, for example, sheet metal and other such stock which progressively advances through various formative stages. Throughout these different stages of manufacture, the continuously-advancing stock often requires the application of liquid lubricants, coolants and the like, and the same is sometimes true with respect to individual workpieces which progress as a continuing stream through various additional processing steps. At times, such liquid lubricants and the like may be applied as a spray or mist, but in other instances it is more advantageous to transfer the liquid by contact with an applicator member which makes contact with the advancing workpieces as they pass a particular location.
One form of such an applicator device which has demonstrated its suitability for such processes is a roller, typically covered on its surface by some relatively soft material (e.g., felt or carpet stock) which will absorb and hold a certain amount of the liquid and readily transfer it by contact to the workpiece as it passes by the roller.
In most instances, the liquid lubricant or the like is applied to such rollers from the outside, by spraying the roller surface or by disposing a drip tube above it from which liquid may fall by gravity onto the surface of the roller. Sometimes, the roller is mounted above a supply tank or container in which the liquid is maintained at a level sufficiently high to contact the roller as it rotates in contact with the workpiece or stock. In either such case, the supply of liquid to the roller is not subject to careful or precise control, and in order to avoid running dry, the supply is usually maintained at a level sufficient to produce an excess on the roller, thereby inevitably causing spatter and throw-off of liquid from the roller and producing a corresponding messy and contaminated area which necessitates various other measures and expense, as well as wasting the liquid and, frequently, applying an undesirable excess amount to the workpiece or stock.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a new and improved form of contact liquid applicator for installations and uses of the above type, by which the indicated problems known in the prior art are resolved advantageously and effectively, as well as in a desirable cost-effective manner.
From a first perspective, the invention provides a new and accurately controlled surface applicator which utilizes a repeating cyclical positive-displacement pump for metering out accurate and controlled amounts of the liquid to the applicator member on an ongoing basis, such that the applicator member carries a predetermined amount of the liquid on its surface for transfer to the workpiece. In instances where (as is often true) the apparatus utilizes a pair of applicator members in mutually opposed and narrowly spaced relation, with the workpiece passing between the applicators, the invention provides means for proportionally varying the metered output of the pump so as to apply predetermined portions thereof to each of the two such applicators in a set thereof.
From another perspective the invention provides a new and advantageous structural configuration for such contact applicators, particularly suitable for applying liquid lubricants and the like in large-area surface applications, wherein at least one of the applicator members comprises a roller which is arranged to be contacted by and rotate with the advancing workpieces or stock and to apply the liquid lubricant or the like to surfaces of the workpiece or stock by contact therewith, and wherein such roller has a liquid-transmissible peripheral wall and the liquid is provided to the interior of the roller under pump pressure, from where it is distributed to the interior of the liquid-transmissible wall for conveyance through the latter to the outer surface, where it forms a dispersion over the entirety of such surface, for uniform application to the advancing workpieces during rotational contact therewith.
In a still further embodiment, the invention provides a surface lubricator for sheet stock and the like having at least one pair of elongated rollers disposed in mutual alignment and closely adjacent relation to receive and pass a workpiece therebetween, wherein at least one of the rollers in the pair is structurally configured to have a generally hollow rigid sleeve-like cylinder with multiple perforations which is readily transmissible by liquid lubricant, and an outer cover of generally resilient material telescoped over and carried on such cylinder. In one particular preferred embodiment, this outer cover is of open-celled foam-type material, although other generally similar media (e.g., felt) may also be used depending upon the circumstances, however, the cover must in any event be readily transmissible by the liquid lubricant, and the apparatus includes means inside the roller for spraying the liquid lubricant outwardly against the porous internal cylinder for migration therethrough to the resilient outer cover, through which the liquid is drawn by capillary action as the film or dispersion of liquid on the outer surface of the resilient cover is continuously depleted by transfer of liquid to the continuously-advancing workpiece.
The foregoing features and attributes of the invention will become increasingly clear upon consideration of the ensuing detailed specification and the attached drawings, depicting certain preferred embodiments of the invention, provided for illustration of the underlying concepts as well as of such particular embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view showing a first embodiment of the invention;
FIG. 2 is a side elevational view of the apparatus shown in FIG. 1;
FIG. 3 is a fragmentary end elevation showing the apparatus illustrated in FIGS. 1 and 2, with outer portions broken away to better show certain internal features;
FIG. 4 is a side elevation showing another embodiment or alternative configuration of the invention;
FIG. 5 is a fragmentary end elevation showing the structure illustrated in FIG. 4, with outer portions broken away to better show certain internal features;
FIG. 6 is an enlarged fragmentary end elevation similar to FIG. 3 showing further details of the structure;
FIG. 7 is a further enlarged fragmentary cross-sectional side elevation, taken along the plane VII--VII of FIG. 6, showing various structural details at one end of a roller, including the mounting thereof;
FIG. 8 is a fragmentary side elevational view of a preferred pump for usage in the invention;
FIG. 9 is an end elevational view of the pump shown in FIG. 8; and
FIG. 10 is a top plan view of the structure shown in FIG. 8.
DESCRIPTION OF PREFERRED EMBODIMENTS
As may be seen in FIGS. 1, 2, 3 and 4, the first embodiment of the invention comprises a single-station contact applicator 10 which basically includes a pair of vertically opposed, horizontally extending cylindrical rollers 12 and 14 that are mounted within trough-like housings 16, 18, respectively, and supported in position by brackets 20, 22 mounted on and projecting outwardly from upper and lower main supports 24, 26, respectively, that are mounted between end plates 28, 30. As illustrated, all such structural members are securely fastened together, as by the bolts illustrated, to form a rigid frame.
As best seen in FIGS. 3 and 6, the upper mounting bracket 20 is preferably a one-piece U-shaped member with downwardly-depending end extremities 20a, which preferably extend laterally from the main support 24 at an angle, to provide an offset mounting extremity 20b at their lowermost end. The aforementioned upper roller housing 16 is preferably mounted in a pivotal manner at extremity 20b by a pin 32, which thus provides an axle or trunnion about which the upper housing 16 and the roller 12 mounted therewithin may be pivoted so as to move the upper roller 12 toward or away from the lower roller 14. Preferably, such pivotal motion is controlled by a pneumatic cylinder 34 or the like which is mounted on the side of the upper support beam 34 and which has its piston 34a pivotally connected by a pin 36 or the like to the upper roller housing 16 by means of an angle bracket 38. Preferably, the pneumatic cylinder 34 is actuated through an adjustable pressure regulator 40 having a gauge 42, such that the amount of pressure applied may be adjusted for different operating conditions, as noted further below. Of course, this requires a pneumatic pressure input, which is supplied through an inlet tube 44 coupled by appropriate fittings to the regulator 40. Thus, pneumatic pressure applied to the inlet 44 at a first level will actuate the cylinder 34 at a second, typically lower and regulated level whereupon cylinder 34 will pivot the upper roller 12 and its housing 16 together in a counterclockwise direction about pin 32, so as to bring the upper roller 12 toward the lower roller 14 and into contact with workpieces, sheet stock, or the like passing between the upper and lower rollers at a predetermined pressure.
The apparatus 10 described above is designed to be modular in nature and may be readily moved from one location to another, and installed in a variety of different environments to accomplish a variety of different purposes. While the size of such a module may of course be widely varied to accomplish particular purposes and accommodate various working conditions, it may also be ganged together with other like modules to provide operating units of various different widths, to accommodate various lateral areas and various widths of sheet stock, etc. An illustrative such ganged apparatus is shown in FIGS. 4 and 5, wherein a pair of the modules 10, 10' are disposed in laterally adjacent, staggered relationship, such that their respective rollers 12, 12' and 14, 14' are disposed in coplanar relationship with one another but slightly offset laterally from one another.
In this ganged arrangement, each of the adjacent modules 10, 10' may have its own actuator 34, 34' for moving the upper rollers 12, 12' toward and away from the lower rollers 14, 14', although the two different such actuators may if desired be supplied pneumatic actuating pressure by a common regulator 40, particularly, where (as is typically true) simultaneous actuation of the rollers is desired. Alternatively, separate sources and different regulators may be utilized, particularly where non-simultaneous or differing-pressure applications are involved. As will be apparent, other components of the additional (ganged) module 10' which correspond to those of module 10 are designated by primed numbers corresponding to those used in the description of module 10, but end plates 28 and 30 thereof are replaced by directly similar but essentially double-sized end plates 128, 130 which are sized appropriately to mount the multiple modules 10, 10' involved.
The preferred structure for each of the rollers 12, 14 is illustrated in more detail in FIG. 7. Each such roller member comprises a cylindrical member having a generally rigid sleeve-like inner support member 50 of sheet metal or the like which is generally of an openwork nature, i.e., having numerous perforations or apertures extending throughout its peripheral wall. Telescoped over the perforate internal cylinder 50 is an outer cover 52 that, in a particular preferred embodiment, is of open-celled polymeric material, e.g., polyurethane foam. While various other materials may be used for the outer member 52, (e.g., resilient felt or the like) it must be moisture-transmissible and is preferably resiliently compressible in nature although it is to be noted that in certain circumstances a more rigid moisture-transmissible member may be utilized instead.
Each end of the perforated cylinder 50 is closed by an end cap 54 (FIG.7) (one such end being shown for illustration), generally comprising a flat cup-like member in its overall nature, having a central opening for insertion of a bearing 58 by which the cylinder is rotatably mounted. As illustrated, each of the end caps 54 mounts one end of its corresponding roller in a freely rotatable manner, supported upon the adjacent end wall 20a, 22a of the corresponding roller housing 16, 22. For example, each such end wall may have a mounting aperture at a predetermined position, for receipt of the protruding cylindrical end portion 60a of a corresponding fitting 60, with end portion 60a providing a trunnion in the form of a stub shaft 60c that receives the inside race 58a of the bearing 58. Preferably, the end cap 54 is press-fit into the end of the perforate cylinder 50, and the bearing 58 is press-fit into the end cap 54, such that the perforate cylinder 50, outer cover 52 and end cap 54 at each end all rotate with the respective bearings 58, about an axis defined by a pair of oppositely disposed stub shafts 60c, which support the roller unit at each opposite end. As illustrated, the central portion 60b of each fitting 60 is externally threaded, and carries a corresponding lock nut 62. The aforementioned aperture through the end wall of housing 16 and 18, through which the fittings 60 extend, is internally threaded to engage the threaded outer portion 60b of fittings 60, such that when the nuts 62 are then tightened against the face of the aforementioned housing end walls, they will lock the fittings 60 securely in place, thereby correspondingly mounting the roller units 12, 14 in position.
As also illustrated in FIG. 7, at least one of the fittings 60 supporting each roller unit 12, 14 has an axially extending internal passage 60c through which liquid may be conveyed. Inside each of the rollers 12, 14, an internal supply tube 68 extends axially between the corresponding stub shaft portions 60a of the two oppositely disposed fittings 60 carrying that roller, to convey liquid provided to the internal passage 60c by an external supply tube 70 which is disposed in flow communication therewith. Each such internal supply tube 68 has a predetermined number of spray apertures 66, which are preferably sized in accordance with the viscosity and surface tension of the liquid to be dispersed thereby, together with pressure under which such liquid is pumped, to thereby provide a desired spray patter or dispersion condition inside each roller, while at the same time retaining all liquid within tube 68 when the supply pressure is removed from it (i.e., not dripping). The downstream end 68a of internal tube 68 will normally be closed, since it typically need not convey liquid onwardly to other stations. Consequently, end 68a may merely be crimped off, as shown, or it may, like the upstream end, be press-fitted into the internal passage 60c of the corresponding downstream fitting 60, and the passage in the latter suitably closed by a plug or the like.
As indicated, each of the internal tubes 68 is provided liquid to be dispersed inside the rollers 12, 14 by the external supply tube 70 (FIG. 7) and the latter is secured to the fittings 60 in sealed relationship, as for example by a compression coupling 64 which is seated in the fitting 60. The external supply tubes 70 receive the liquid to be dispensed within the rollers 12, 14 from a pump 72 (FIGS. 1, 3, 4, 5 and 6), to which the liquid is supplied from a reservoir (not shown) through a supply tube 74. Pump 72 is preferably self-priming so that the liquid need not be supplied to it under pressure. In the ganged embodiment 10, 10' shown in FIGS. 4 and 5, separate pumps 72, 72' are shown, each for supplying a corresponding roller set 12, 14, although in some applications a single such pump may be used for this purpose, preferably with corresponding flow-dividers of a conventional nature (not shown) that may be adjustable to vary the proportional amount of liquid provided to each roller set as well as to each roller in a set.
The pump 72 is preferably, in accordance with preferred embodiments, a positive-displacement, cyclically operable volumetric metering device, preferably of the type shown in FIGS. 8, 9, and 10. As there illustrated, each such pump unit actually comprises a pump module 75 and a manifold block 76 by which fluid is provided to the pump module 75 and by which its output is distributed. As may be recognized, the preferred pump module 75 is preferably of a type whose overall nature is generally known, comprising a block-like housing 78 having a particularly configured longitudinal internal passage and corresponding piston to positively displace metered amounts of fluid from a metering chamber formed therein. In the embodiment shown, fluid from the external supply which is conveyed to the inlet aperture 82 of manifold 76 by supply tube 74 is routed to the pump module 75 through internal passages 83, 85 and passes into the pump chamber 87, in which the piston 80 is reciprocally disposed. The output of the pump module 75 is ejected through the dual outlet passages 84, 86 and their respective outlet apertures 98, 100, and comprises a continuing succession of precisely metered volumetric quantities.
The internal structure of the particular preferred embodiment of pump module 75 is shown in FIG. 8, where it will be seen that piston 80 is retained in place by annular bushing 88 which also provides a guide through which the forward end of piston 80 is reciprocated. Guide bushing 88 is secured precisely in place by a snap ring 90 or the like and preferably has an annular seal 91 around its outer periphery. Internally, a centrally disclosed pump section 92 of piston rod 80, of enlarged diameter, moves back and forth through the internal metering chamber as a function of mechanical pumping force applied to an outer end portion 94 of the piston rod 80 that preferably carries a replaceable, smoothly rounded bearing cap. Thus, as seen in FIG. 8, piston rod 80 is forced to the right by the application of such pumping forces, against the resilient pressure of a return spring 96 disposed in the pumping chamber, which normally keeps the forward face of the pump section 92 seated against the rearward face of the guide bushing 88.
Accordingly, the supply tube 74 provides the fluid which is to be metered out to the rollers 12, 14 through an inlet aperture 82 in the manifold block 76 (FIGS. 8 and 10), which communicates with an orthogonal passage 83 therewithin leading to the downwardly extending supply passages 85 that connect to the metering chamber within the pump housing 78. As the piston 80 is reciprocated back and forth laterally within the pump housing 78, the pump section 92 of the piston acts to displace a continuous succession of metered quantities of fluid, which are forced outwardly from the metering chamber and into one or the other of the outlet passages 84, 86 that lead to and communicate with the outlet apertures 98, 100 (FIG. 10) in the manifold block 76. More particularly, in the preferred embodiment shown, the pump 72 is double-acting, i.e., each time piston 80 moves to the right (as shown in FIG. 8) it ejects a metered charge of liquid out of the right-hand passage 86 and outlet 100 (FIGS. 9 and 10), as the piston moves to the left it ejects a basically identical charge out passage 84 and outlet 98.
In regard to the pumping action of piston 80 as just described, it should be noted that the pump 75 preferably includes certain check valves, e.g., valves 102, 104, 104' shown in FIGS. 8 and 9, which in this implementation are believed novel. More particularly, each such valve comprises a one-piece elastomeric device of the type known generally as a "Duck-bill" check valve, which is typically used in other types of applications, e.g., on the ends of conduits, etc. Thus, while of a nature generally known in the art, the use of such a device in a pump or the like, such as is illustrated in FIGS. 8 and 9 is believed novel, and contributes valuable efficiencies of manufacture and assembly, as well as good pumping operation. As will be understood, each such device comprises basically a small resilient tube extending from an annular collar at one end, with the other end of the tube forming a slit-like opening in the nature of a pair of lips. Thus, positive pressure from the collar end readily forces the "lips" open to pass fluid, whereas the opposite condition closes the "lips" to block fluid flow. The operation of such check valves to open or close passages 84, 85 and 86 for fluid flow during the pumping strokes of piston 80 is believed to be readily apparent, but it is to be expressly noted that, in accordance with the present invention, the annular collar mentioned above is used as a seal, analogous to an O-ring, between the pump module block 78 and the manifold block 76, thereby obtaining further economic advantage and manufacturing efficiency.
Reciprocation of the pump piston 80 in the aforementioned matter is desirably made to be synchronous with rotation of the rollers 12 and 14, so that the resulting quantities of liquid pumped to the rollers may maintain a predetermined continuous rate of application to the sheet stock or workpiece(s) continuously feeding between the rollers, in a manner that is independent of the workpiece feed rate. By doing so, the supply of liquid to the rollers may be made to be consistent with the transfer of liquid from their surface. While this desired end may be achieved in a number of different ways, one preferred way is to actuate the pump piston 80 directly by one or the other of the rollers themselves, as a function of its rotary movement, and in accordance with a preferred embodiment of the invention this is accomplished by mounting the pump assembly 72 directly adjacent one end of one of the rollers, e.g., the lower roller 14 (FIGS. 2-6) (or the upper roller 12, FIG. 1). By providing an appropriately positioned hole (FIG. 7) through the adjacent end wall of the lower trough or housing 18 (and its mounting bracket portion 22), the outer end portion and bearing cap 94 of the pump piston 80 may engage and ride against the annular interior surface of the adjacent end cap 54 and, by providing a rotary cam surface 56 on end cap 54, in the form of an undulating annular surface, the rotation of the roller unit is transferred directly to the bearing cap 94 on the end of the pump piston 80 thereby pushing the latter inwardly and allowing it to be returned back outwardly by return spring 96 upon each rotation of the roller. Of course, various cam configurations may be imparted to the end cap 94 to accomplish essentially any desired number of pump strokes per revolution (the particular example illustrated in FIG. 7 showing a single such stroke). At the same time, the pump piston motion is made to be synchronous with roller rotation, and it is also made smooth and consistent. As already indicated, pump action may be accomplished in a number of different ways, but the particular embodiment just described has definite advantages since few if any additional parts are needed, the pump-actuating motion is already present by virtue of roller rotation, and the action is positive, foolproof and extremely reliable. In addition, pump operation may readily be altered by substituting other end caps having other cam profiles machined or otherwise formed in them.
As may be seen from the foregoing, the reciprocal movement of the pump piston 80 by the cam surface 56 on end cap 54, and the resulting volume of liquid displaced outwardly by the pump each time the piston is reciprocated is, in the first instance, a direct function of the relative height of the cam surface 56 with respect to that at which the pump piston occupies the position shown in FIG. 8, with pump section 92 seated against the guide bushing 88. That is, the relative height of the cam surface 56 will determine the length of the pump piston stroke and the corresponding distance that the pump section 92 moves in traversing the metering chamber. A further and readily adjustable control over the amount of liquid pumped on each pump stroke is provided by the manually-adjustable nuts 108, 110, since by threading nut 108 further onto the threaded pump piston extremity 106 from the position shown in FIG. 8, the allowable return of the pump piston toward the bushing 88 becomes increasingly reduced, and as a result the effective length of the pump stroke is correspondingly reduced. Thus, continuous minute adjustments may be made in the amount of liquid metered by the pump in each of its cycles of operation. Of course, the second nut 110 is merely to lock the first such nut 108 in its position of adjustment.
As will now be understood, the described apparatus operates as a contact applicator for applying various liquid media to surfaces of workstock or workpieces moved continuously or intermittently between the two rollers 12 and 14. In this regard, the preferred form of roller shown and described in conjunction with FIG. 7 has definite advantages, in that it facilitates reliable, continuous, trouble-free distribution of the precisely metered liquid onto the outer roller surface, for transfer to even irregularly shaped or uneven workpieces by rolling contact with them. Further, the described resiliently compressible felt or open-celled polymeric foam outer cover 52 facilitates the overall uniformity and controlled dispersion of the liquid sprayed outwardly from internal roller tube 68, which passes outwardly to the cover through the numerous openings in the perforated cylinder 50. Of course, controlled operation of the actuating cylinder 34 may impart greater or lesser degrees of resilient compressive deformation of outer cover 52, whose thickness may vary from one application to another as a function of, and to best accommodate, the particular circumstances involved, and in this manner the liquid to be distributed may be applied at various depths to irregular or undulating surfaces of sheet stock or individual workpieces passing by in contact with the outer cover. Of course, such rolling deformation of the cover 52 also enhances the continuous distribution and redistribution of liquid through it in a uniformly dispersed manner, due to what is in effect capillary action within the minute passages extending throughout the cover.
The convenient precise control afforded by the preferred positive-displacement pump 72 facilitates the operational capability noted above, since it provides for ready adjustability as well as consistent precise control of the amount of liquid carried by the outer roller portion or cover 52. As a result, the application of liquid to the workpiece is always in the desired amount, and is always synchronized with the particular feed rate of the workpiece, increasing or decreasing automatically with feed rate. The preferred roller configuration insures that the liquid to be dispensed is distributed uniformly across the width of the roller for equal application to all parts of the workpiece, and in fact the modular configuration of the apparatus enables the system to apply different quantities of the liquid to different areas across the width of the workpiece in the event that is desired, since each different module may employ a different pump or metering orifice which may be adjusted for a different amount of liquid delivery that the other roller receives. At the same time the accurate liquid control provided by the system greatly reduces or eliminates throw-off or other inadvertent, extraneous dissipation of the liquid at the point of application, since an excess supply at the roller may be eliminated by proper adjustment of the system. Thus, little cleanup is required, and there is no excess liquid to be recovered, recirculated, or otherwise treated. This provides a cleaner work area, reduces waste and corresponding expense, and essentially eliminates an area of environmental concern. In addition, it enables increased production rates as well as improved product quality and lower overall system maintenance.
As may be perceived from the forgoing, the apparatus and system in accordance with the invention is particularly well-adapted to the application of liquid lubricants to sheet metal stock in metalworking operations such as punching, stamping, fine blanking, roll forming, etc., but it is also of considerable advantage in other such industrial processes and the like, e.g., application of various finished, protective coatings, etc.
The foregoing description is of preferred embodiments only, and it will be readily appreciated by those skilled in the art that modifications may be made to such embodiments, and the invention may be implemented in other particular ways without departing from the concepts disclosed. All such modifications and other embodiments are to be considered as included in the following claims, unless these claims by their language expressly state otherwise. | A liquid-dispenser and surface applicator for sheet stock or other such workpieces, including an applicator member which preferably comprises at least one generally hollow elongated roller which contacts advancing workpieces and applies liquid to surfaces thereof as they pass. A cyclically repeatable liquid-dispensing apparatus meters predetermined pulsed quantities of the liquid from a source and these are coupled to a dispensing tube disposed within and extending axially along the inside of the applicator roller. The dispensing tube has a closed end which causes the pulses of liquid coupled to it to be pressurized and thus expelled as a spray in metered quantities through a series of spaced apertures in the dispensing tube. The sprayed liquid passes into the hollow interior of the roller and the outer wall of the roller is perforate in nature, whereby the sprayed liquid passes through the wall and is absorbed by a resiliently compressible, liquid-transmissible outer cover, throughout which the liquid becomes dispersed for application to the advancing workpieces by direct contact with them. | 1 |
This is a continuation of co-pending application Ser. No. 08/150,938 filed Nov. 12, 1993 is a continuation-in-part of U.S. Ser. No. 07/554,615 for "Containerization System for Agrochemicals and the Like" filed Jul. 18, 1990now U.S. Pat. No. 5,080,226. This application is filed by the same inventors named in U.S. application Ser. No. 07/554,615, incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to a containerization system and to containers which are particularly suitable for storing, packaging and transporting toxic or hazardous products, e.g., agricultural chemical compounds, such as pesticides.
BACKGROUND AND PRIOR ART
At present, most hazardous and toxic liquids are stored in metal drums or, where smaller quantities are involved, in plastic containers. Hazardous or toxic compounds, such as agrochemical compounds, are formulated in various compositions.
The expression toxic or hazardous compounds as used herein means an industrial chemical or agrochemical compound, which, if released in the quantity or concentration normally present in storage and shipping containers, may cause damage to the environment or be injurious to a person contacted by it.
With respect to agricultural chemicals, liquid compositions, particularly in the form of concentrates, are most convenient for farmers because of the relative ease with which they can be handled, formulated and used. However, there are significant difficulties in handling such liquid compositions.
There is a danger of spillage or leakage if holes develop in the containers or if containers are accidentally dropped and thereby crack or fail. Containers have been developed which possess great resistance to impact and shock. While such containers are secure under normal storage and handling conditions, in the event of an accident, for example during transporting, there remains an appreciable risk of spillage or leakage with rapid loss of liquid. Leakage of toxic and hazardous chemicals can create damage to the environment.
The chemical and packaging industries have long sought a secure container which provides sufficient safeguards for those handling it, such as farmers and transporters, as well as adequate protection for the environment.
It is known, for example, to package agrochemicals in soluble bags or sachets made from films. However, such films may crack and break and thus cause leakage of the agrochemical contents. There are a variety of defects which can occur in films, which may lead to weaknesses of the film and become a potential source of leakage. For example, the presence of air bubbles, dust particles or foreign bodies in gel particles or the existence of thin points on or in the film are all potential weak points. If a film with such a weak point is subjected to a lot of handling or physical shock, the film may fail at a weak point. This is especially a problem in the agrochemical industry where containers may be subjected to repeated and uncontrolled handling by distributors, transporters or farmers.
In other industries such as pharmaceuticals and cosmetics, gel formulations have been used as a means for packaging pharmaceutical or cosmetic products. However, such gel formulations are often utilized for aesthetic and other reasons and not as part of a containerization system for holding and securing toxic or hazardous chemicals. Furthermore, the gels used for pharmaceutical or cosmetic purposes are generally water-based.
Another possibility is to provide agrochemicals in the form of wettable powders which can be contained within a bag which may be water soluble or water dispersible. However, when wettable powders are placed in water soluble bags and then added to water in spray tanks, the bag floats because the bulk density of the product is low. As the bag floats in the spray tank, it can become attached to either the side of the tank or recirculation piping within the tank. This is because the materials used in water soluble bags, such as polyvinylalcohol, tend to be sticky and become a very good adhesive when wet. The longer it takes to get the bag to dissolve, the higher the probability that the bag will adhere to some part inside the spray tank. Another problem is that as the bag dissolves and releases the powder, some powder gets bound to the bag and does not disperse. Also, in view of its relatively low density, the bag floats above the water level in the tank which further inhibits full dissolution of the bag. This problem can build up over time and cause numerous problems due to filters getting clogged by either undissolved bag or wettable powder that has not been properly wetted and which becomes stuck to the filter system of the spray tank or the spray nozzles. This causes serious problems since the farmer/applicator must clean this up, potentially exposing himself to the chemical itself.
Also suggested have been containing systems for pesticides in which the liquid-containing active ingredient is enclosed within soluble bags or sachets. However, the bags tend to develop pinholes and the contained liquid leaks under such conditions causing potential injury to the environment.
It has also been proposed for pesticides to be packaged in soluble bags or sachets which contain an air space to absorb shocks and to avoid leakage. This feature does tend to reduce bag failure. However, this does not avoid the problems of pinholes. Also, this approach has a disadvantage in that such bags cannot effectively be used as a self-dispensing container. The specific gravity of liquid and the included air space, causes such a bag to float and not to become immersed when placed in a spray tank. As a result, there is incomplete contact between water and the bag which is not adequate for rapid dissolution.
SUMMARY OF THE INVENTION
The present invention provides a containerization system comprising a water soluble or water dispersible bag which encloses, holds and secures a chemical compound which can be a toxic or hazardous chemical; the chemical compounds is present in a gel which is of essentially organic material. The present invention is also directed to a containerization system that can self-dispense the active ingredient contained therein when placed in an aqueous medium. The present invention also concerns a method for holding and securing chemicals in a manner which reduces the chances of the chemical spilling, leaking or contacting with the environment during shipping and storage.
An object of the instant invention is to provide a new method and system for storing, containing and packaging toxic and hazardous compositions such as agrochemicals which is safe for handling.
Another object of the instant invention is to provide a new system to contain agrochemicals which is easy to manipulate for the farmer.
Another object of the instant invention is to provide a new system for containing chemicals such as agrochemicals which enables such chemicals to be readily, rapidly and easily solubilized and/or dispersed in water, preferably in less than five minutes under normal agitation.
Another object of the instant invention is to provide a new system for storing, containing and packaging chemicals such as agrochemicals, said system utilizing a minimum amount of volumetric space.
Another object of the instant invention is to provide a new container and a new system for containing hazardous compounds which diminishes the risks of leakage and pollution.
Another object of the instant invention is to avoid leakage through pinholes of a bag containing hazardous compositions. Only one pinhole among thousands of bags is enough to cause a lot of trouble, because the liquid going through the pinhole contaminates all of its environment.
Another object of the instant invention is to avoid breakage of the container with its contents. When the container is rigid, there is substantial possibility of simple breakage. With a liquid in a bag this possibility is somewhat reduced, but the liquid still transmits the shocks and there is the problem of hydraulic hammer effect. An object of the instant invention is to avoid this hydraulic hammer effect. It has been proposed to reduce the possibility of breakage by means of an air space in the bag, but this represents some loss of storage space.
Another object of the present invention is to dissipate, as much as possible, the force of a shock to a container.
Another object of the present invention is to provide a shock absorbing system for containing agrochemicals, e.g., pesticides.
A further object of the present invention is to provide a containing system wherein less solvent is needed in the formulation of the chemical, which is a cost saving advantage both in shipping and manufacturing.
An additional advantage of the present invention is that higher concentrations of active ingredient can be obtained when using gels rather than liquids.
The present invention seeks to provide a new container system for agrochemicals which quickly dissolves when put into water. The invention further seeks to provide a new container system for agrochemicals which reduces the risk of clogging the spray nozzles or the filters of spray tanks.
Other objects and advantages of the invention will be apparent from the description which follows. Other objects of the invention will better appear from the following description. The objects of the invention can be achieved in full or in part by means of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The containerization system of the present invention comprises a bag composed of a water soluble or water-dispersible film which envelops and encloses a hazardous or toxic chemical present in a gel. The gel provides its own discrete advantages and applications as a concentrate for the chemical compound. When the gel of the present invention is used in conjunction with the enveloping bag, a containerization system is provided which is unique in its ability to maintain integrity and prevent leakage of the subject chemical into the environment.
The ultimate purpose of the containerization system is to preserve a toxic or hazardous chemical in a form which can be safely handled and which is secured in a manner preventing its rapid leakage into the environment. The invention achieves these objectives not merely by creating an enveloping barrier of protection but by employing a system integrally related to the subject chemical.
The present invention also includes a method for holding and securing chemical compounds, such as toxic and hazardous compounds, in a manner to prevent their contact with the environment during shipment and storage.
As already explained, a toxic or hazardous chemical can be any compound which can cause injury to persons exposed to the chemical or which can damage the environment. One class of such compounds is agricultural chemicals or agrochemicals such as pesticides (e.g., herbicides, fungicides, nematocides, insecticides, etc.) and plant protection agents (e.g., plant growth regulators, nutrients, etc.).
In practice, the gel material used in the invention comprises the active ingredient, which is the hazardous or toxic chemical in association with ingredients that participate in or assist in the formation of the gel, for example, surfactants, dispersants, thickeners, solvents and gelled or gelling agents.
A gel is generally a colloid in which the dispersed phase has combined with the continuous phase to produce a viscous, jelly-like product. A gel can be a dispersed system consisting typically of a high molecular weight compound or aggregate of small particles in very close association with a liquid. The gels used in the invention usually have an organic continuous phase, in contrast to most existing gel materials which are water-based and have an aqueous continuous phase. Furthermore, the gels used in the invention have essentially one physical phase, at least as can be seen when visually observed. Gels that are preferred for the invention are those which can be divided by cutting and whose cut parts are able to merge together by simple juxtaposition.
Solvents useful in the gel of the present invention are organic solvents such as petroleum hydrocarbons which include aliphatic and aromatic solvents. Surfactants that can be used in the invention are nonionic and anionic surfactants and combinations thereof. Illustrative gelling agents that can be used include mixtures of dioctyl sulfosuccinate salt and sodium benzoate, tetramethyl decynediol ethyoxylated dialkylphenol, combinations of modified clay and propylene carbonate, hydrogenated castor oil, ethoxylated vegetable oil, dioctyl ester of sodium succinic acid and sodium benzoate, diatomaceous earth, and mixtures of dimethyl hexane and hexyne diol.
The gel material which is used in the invention is essentially a material which has a phase difference L between the controlled shear stress and the resulting shear strain such that tgL is less than or equal to 1.5, preferably less than or equal to 1.2. TgL is the tangent of the L angle (or phase difference). The measurement of L is made by means of a rheometer having a flat fixed plate and a rotating cone above this plate such as the angle between them is less than 10°, preferably 4°. The cone is caused to rotate by means of a controlled speed motor; the rotation is a sinusoidal one, i.e., the torque and the angular displacement change as a sine function with time. This angular displacement corresponds to the hereabove mentioned shear strain; the torque of the controlled speed motor (which causes the angular displacement) corresponds to the hereabove mentioned controlled shear stress.
The gel which may be used in the invention is primarily organic, which means that it has a low water content, generally less than 5% (by weight), preferably less than 3%, more preferably less than 1%. Typically the gel is water soluble or water dispersible.
Generally, the gel which may be used in the invention is a material having a viscosity from 500 centipoise (measurement made with a Brookfield viscometer at 23° C. with a flat plate rotating at 20 round per minute) to 50000 centipoise, preferably between 1000 and 30000 centipoise, and still more preferably between 1 000 and 5 000 centipoise.
According to one embodiment of the invention, the gels which are used in the invention are successful when submitted to the following puncture test: 500 g of a material/gel are placed in a polyvinyl alcohol water soluble bag (having a 50 micron thick wall) and heat sealed. The bag is suspended using a binder clip at which time a dissecting needle (the diameter of which is 0.1 mm) is inserted into the lower third of the bag and withdrawn. The material/gel is observed for 30 minutes to determine leakage. A gel which is successful in the present test shows no leakage and preferably may be used in the invention. A droplet of material may appear on the hole, but no persistent flowing or leakage occurs.
Preferred characteristics of a gel which is appropriate for the invention are (alone or in combination):
* The viscosity should be generally between 500 and 50000 centipoise, preferably between 1000 and 30000 centipoise, and still more preferably between 1 000 and 5 000 centipoise (measurement made with a Brookfield machine).
* The dispersibility in water should be substantially complete when the gel is subjected to normal agitation in water after a 15-minute interval, preferably after a 10-minute interval.
* The gel preferably contains an essentially non-aqueous solvent.
The chemical nature of the enveloping film constituting the bag can vary quite widely. Suitable materials are water soluble (or possibly water dispersible) materials which are insoluble in the organic solvents used to dissolve or disperse the active ingredient (e.g., agrochemical). Specific suitable materials include polyethylene oxide, such as polyethylene glycol; starch and modified starch; alkyl and hydroxyalkylcellulose, such as hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropyl cellulose; carboxymethylcellulose; polyvinylethers such as poly methyl vinylether or poly(2-methoxyethoxyethylene); poly(2,4-dimethyl-6triazinylethylene; poly(3-morpholinyl ethylene); poly(N-1,2,4triazolylethylene); poly(vinylsulfonic acid); polyanhydrides; low molecular weight melamine-formaldehyde resins; low molecular weight urea formaldehyde resins; poly (2-hydroxyethyl methacrylate); polyacrylic acid and its homologs.
A preferred enveloping film comprises or is made from polyvinylalcohol (PVA). When PVA is used, it is preferably partially or fully alcoholyzed or hydrolyzed, e.g., 40-100%, preferably 80-99% alcoholyzed or hydrolyzed, as a polyvinyl acetate (or other ester) film. Copolymers or other derivatives of such polymers can also be used.
Additional preferred materials for constituting the bags in the invention are polyethylene oxide, methylcellulose, and polyvinylalcohol.
The following features, alone or in combination, constitute additional preferred features of the invention:
According to another feature, the gels and the bag containing gel of the invention preferably have a density greater than 1, preferably greater than 1.1.
According to another feature the gels contained in the bags of the invention preferably have spontaneity (as hereafter defined) less than 75, preferably less than 25.
According to another feature, the bags of the invention generally have a capacity of from 0.01 to 12 liters; preferably they have a capacity of from 0.2 to 12 liters, more preferably from 0.45 to 6 liters.
According to another feature the bag is preferably made of a polymeric water soluble film. The thickness of this film is generally between about 10 and about 500 microns, preferably between about 20 to about 100 microns.
According to another feature, the bags of the invention when filled to capacity can contain more than 90% gel by volume, preferably more than 95%, and more preferably more than 98% gel.
EXAMPLES
The following examples are given for illustrative purposes and should not be understood as restricting the invention.
In these examples, the Brookfield viscosity was measured, as previously indicated, with a Brookfield viscosimeter which had a flat plate rotating at 20 revolutions per minute. In all of the following examples, the prepared gels had a tgL of between 0.75 and 1.5.
The emulsion stability of the prepared gels is evaluated according to the following method: 1 ml of the gel is mixed with 99 ml water in a 150 ml tube; the tube is inverted 10 times at the rate of 1 complete inversion per second. Rating of the emulsion stability is made by reading the relative amount of phases after 24 hours. The emulsion stability is rated as follows: "excellent" if the amount of emulsion (phase looking like milk) represents 98 to 100% (v/v) of the total, the balance being cream or thin; "good" if the amount of emulsion represents 90 to 98% (v/v) of the total, the balance being mainly cream with no more than 5 ml being thin; "fair" if the amount of emulsion represents 70 to 90% (v/v) of the total, the balance being cream or thin; and "poor" if the total of emulsion represents 70 or less % (v/v) of the total.
The spontaneity is assessed according to the following method: A mixture of 1 ml gel with 99 ml water are put into a 150 ml glass tube which is stoppered and inverted by 180 degrees (upside down). The number of inversions required to completely disperse the gel is called the spontaneity.
EXAMPLE 1
A gel is made by stirring and shaking at 50° C. a mixture of the following ingredients until they are each dissolved or dispersed:
______________________________________active ingredient: the herbicide 2,4-D: 64.8%phenoxy benzoic acid (isooctyl ester):solvent: aromatic solvent with flash point 24.2%of 65° C.:adjuvants:non ionic/sulfonate blended emulsifier: 4%calcium alkylbenzene sulfonate: 1%mixture of dioctylsulfosuccinate salt and 6%sodium benzoate______________________________________
During stirring, a dissolution or dispersion appears, and thereafter gelation. Gelation increases as the mixture cools to room temperature (20° C.).
The Brookfield viscosity of the gel is 3000 centipoise.
The emulsion stability is "good" according to the above described test.
1100 g of this gel are put in a one-liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density of the gel and of the bag containing the gel is 1.1.
The bag is dropped 10 times from 1.2 m above the ground. No breaking or leakage is observed.
The bag is put into a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). The bag and its contents are dispersed within a 3 minute interval. There is no clogging in the filter, which is a screen having 0.28 mm openings.
EXAMPLE 2
The procedure of Example 1 is repeated, using the same active ingredient in a mixture containing the following adjuvants:
______________________________________non ionic/sulfonate blended emulsifier: 5.2%tetramethyl decynediol: 30%______________________________________
The Brookfield viscosity of the gel is 3000 centipoise.
The emulsion stability is good using the above described test.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 3 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 2
The procedure of Example 1 is repeated, using the same active ingredient in a mixture containing the following adjuvants:
______________________________________non ionic/sulfonate blended emulsifier: 21.5%calcium alkylbenzene sulfonate: 3.7%ethoxylated dialkylphenol: 10%______________________________________
The Brookfield viscosity of the gel is 3000 centipoise.
The emulsion stability is good using the above described test.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 3 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 4
A gel is made by stirring at 50° C. a mixture of:
______________________________________active ingredient: bromoxynil acid in the 61.15%form of an octanoate ester:solvent: aromatic solvent with a flash 22.85%point of 38° C.:polyaryl phenolethoxylated: 6%calcium alkylbenzene sulfonate: 2%clay which has been modified by addition of 6%methyl groups:propylene carbonate (activating the thickener): 2%______________________________________
These materials are mixed together while shearing with an attritor mixer. The product started to gel within a few minutes.
The Brookfield viscosity of the gel is 4200 centipoise.
The emulsion stability is good using the above described test.
The spontaneity is 38.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 10 minutes interval. There is no clogging in the filter which is a 50 mesh screen.
EXAMPLE 5
The procedure of Example 4 is repeated, using a mixture containing the following components:
______________________________________active ingredient:bromoxynil octanoate: 18.85%bromoxynil heptanoate: 13.85%methyl chloropropionic acid (isooctyl 37.4%estersolvent:aromatic solvent with a flash 11.1%point of 38° C.:hydrogenated castor oil: 3%ethoxylated vegetable oil: 3%non ionic/sulfonate blended emulsifier: 13%______________________________________
These materials are mixed together while shearing with an attritor mixer. The product started to gel within a few minutes.
The Brookfield viscosity of the gel is 3150 centipoise.
The emulsion stability is good using the above described test.
The spontaneity is 20.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 10 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 6
The procedure of Example 5 is repeated using a mixture containing the following components:
______________________________________active ingredient:______________________________________bromoxynil octanoate: 18.4%bromoxynil heptanoate: 14%methyl chloropropionic acetic acid 36.6%(isooctyl ester)non ionic/sulfonate blended emulsifier: 9%sodium sulfonate of naphthalene formaldehyde 3%condensate:dioctyl ester of sodium sulfosuccinic acid 2%and sodium benzoatediatomaceous earth: 17%______________________________________
These materials are mixed together while shearing with an attritor mixer. The product started to have the appearance of a smooth paste, and is a gel within a few minutes.
The Brookfield viscosity of the gel is 9000 centipoise.
The emulsion stability is good using the above described test.
The spontaneity is 9.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 10 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 7
The procedure of Example 5 is repeated, using a mixture containing the following components:
______________________________________active ingredient:bromoxynil octanoate 18.89%bromoxynil heptanoate: 12.59%atrazine 44.58%solvent:same as in example 5 18.54%amine salt of alkylarylsulfonate: 2.7%polyethylene glycol: 2.7%______________________________________
These materials are mixed together while shearing with an attritor mixer. The product started to have the appearance of a smooth paste, and is a gel within a few minutes.
The Brookfield viscosity of the gel is 7300 centipoise.
The emulsion stability is good using the above described test.
The spontaneity is 15.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 10 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 8
The procedure of Example 7 is repeated, using a mixture containing the following components using:
______________________________________active ingredient:bromoxynil octanoate: 33.7%methyl chloropropionic acetic acid 36.2%(isooctyl ester)solvent:solvent:aromatic solvent with a 3%flash point of 65° C.non ionic/sulfonate blended emulsifier: 8.5%calcium dodecyl benzene sulfonate: 1%tetramethyl decyne diol: 17.6%______________________________________
These materials are mixed together while shearing with an attritor mixer. The product started to have the appearance of a smooth paste, and is a gel within a few minutes.
The Brookfield viscosity of the gel is 2200 centipoise.
The emulsion stability is good using the above described test.
The spontaneity is 14.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 5 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 9
The procedure of Example 8 is repeated, using a mixture containing the following components:
______________________________________active ingredient and solvent are the same as inexample 8, and amount of active ingredient is the samesolvent is the same but the amount is 10.6%calcium dodecyl benzene sulfonate: 2%mixture of dimethyl hexane and hexyne 11.5%diol:calcium alkylaryl sulfonate and a 6%polyarylphenol ethyoxylate:______________________________________
These materials are mixed together at 90° C. while shearing with an attritor mixer. The product started to have the appearance of a smooth paste, and is a gel within a few minutes.
The Brookfield viscosity of the gel is 2500 centipoise.
The emulsion stability is good using the above described test.
The spontaneity is 5.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 5 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings.
EXAMPLE 10
The procedure of Example 5 is repeated, using a mixture containing the following components using:
______________________________________active ingredient:bromoxynil octanoate: 33.5%bromoxynil heptanoate: 33.5%solvent:aromatic solvent with a flash point 22.75%of 65° C.:non ionic/sulfonate blended emulsifier: 4.5%calcium dodecyl benzene sulfonate: 1%mixture of dioctyl sodium sulfosuccinate 4.25%and sodium benzoate:tetramethyl decyne diol: 0.5%______________________________________
These materials are mixed together at 50° C. while shearing with attritor mixer. The product started to have the appearance of a smooth paste, and is a gel within a few minutes.
The Brookfield viscosity of the gel is 4850 centipoise.
The emulsion stability is excellent using the above described test.
The spontaneity is 10.
1100 g of this gel are put in a 1 liter bag made of a film of PVA (88% hydrolyzed polyvinyl acetate; cold water soluble; thickness: 55 microns). The bag, which is almost full (about 95% v/v), is hot sealed. The density both of the gel and of the bag containing the gel is 1.1.
The bag is then dropped 10 times from 1.2 m upon the ground. No breaking or leakage is observed.
The bag is placed in a tank containing water under gentle agitation (that is to say such as that obtained with pump recycling). It is dispersed within a 3 minutes interval. There is no clogging in the filter which is a screen having 0.28 mm openings. | This invention relates to a containerization system and to containers which are particularly suitable for storing, packaging and transporting toxic or hazardous products, such as agricultural chemicals. The containerization system comprises the chemical in the form of a gel which is contained within a water-soluble or water-dispersible bag. | 0 |
FIELD OF THE INVENTION
The present invention relates to a fluff scattering preventing device in a winder.
RELATED ART STATEMENT
For the removal of fluff in a winder there have been proposed various devices, including a device wherein a car having a depending, cleaning pipe such as a suction pipe or a blow-off pipe is reciprocated along a ceiling rail disposed above the winder, and a device utilizing air curtain such as that shown in Japanese Patent Publication No. 6779/76.
In any of the above devices it is difficult to effect a complete removal of fluff produced in the winder. In the use of the moving cleaning pipe, the winding unit is cleaned only intermittently, that is, the effect of the cleaning is extremely unsatisfactory. On the other hand, in the device wherein a band-like air current is ejected concentratively from above the winder toward the front of the winding unit, like air curtain, the air pressure is diffused and reduced in the vicinity of the yarn feed bobbin located in a lower position where fluff is most likely to be produced, so that a large quantity of fluff from the bobbin is scattered into the atmospheric air, thus causing pollution of the air in the factory.
In an automatic winder, yarn which is rewound and drawn out from a yarn feed bobbin passes through a balloon guide called a balloon breaker, then travels through upper tenser, slub catcher, etc. and is wound up to a package being rotated by a traverse drum.
As such balloon guide there is used, for example, a balloon guide of the type wherein balloon is throttled at one point, or a mere cylindrical type having a certain length.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device capable of discharging fluff from a winder in an extremely effective manner.
According to the illustrated embodiment of the present invention, a cover is provided at a portion where fluff is very likely to occur, that is, the position of a yarn feed bobbin, to cover this portion, thereby enclosing the fluff therein, and a suction pipe is connected to a part of the cover to discharge the fluff by suction.
The cover of the present invention may be provided with a balloon guide at inner portion of the cover. The balloon guide is formed with a tapered throttling portion in a predetermined internal position of a cylindrical body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view showing an embodiment of the device of the present invention;
FIG. 2 is a plan view thereof;
FIG. 3 is a side view showing a rod drive mechanism;
FIG. 4 is a front view of a cover body;
FIG. 5 is a side view thereof;
FIG. 6 is a plan view thereof;
FIG. 7 is a front view of a balloon guide;
FIG. 8 is a perspective view thereof;
FIG. 9 is a schematic side view showing an example of construction of a winding unit;
FIG. 10 is a sectional front view showing a first embodiment of a balloon guide of the present invention;
FIG. 11 is a plan view thereof;
FIG. 12 is a sectional front view showing a second embodiment of the balloon guide of the invention;
FIG. 13 is a plan view thereof; and
FIG. 14 is a schematic side view showing an example of construction of a winding unit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 9 shows an example of a winding unit. The winding unit, indicated at 1, is held in place by a support pipe 2 and a suction pipe 3. A yarn feed bobbin 4 is brought into a predetermined position in the winding unit, and yarn Y, which is drawn out from the bobbin 4, passes through a tenser 7 and a slub catcher 8 along guides 9, 10, 11 and 12 and is wound up to a take-up package 14 which is rotated by a traverse drum 13. Numeral 15 denotes a yarn joining device; numeral 16 denotes a suction mouth for guiding the yarn on the package side to the yarn joining device 15; and numeral 17 denotes a relay pipe for guiding the yarn on the feed bobbin side to the yarn joining device 15. Each winding unit is provided with these components. A large number of such winding units 1 are arranged side by side to constitute one automatic winder.
Various methods are adoptable for supplying the yarn feed bobbin 4 to the predetermined position in the winding unit 1. In this embodiment there is shown a winder of the type in which the feed bobbin 4 is fitted upright on one of bobbin trays 18 which are independent of each other, and in this state the bobbin is conveyed to the winding unit, followed by winding and discharge from the unit. Of course, various types of winders are employable, including a winder wherein each winding unit has a magazine for storing plural bobbins, and a winder wherein, unlike the above, each winding unit is not a fixed type but circulates along an elliptical path.
In the case where a bobbin after spinning from a ring spinning frame, or a spinning bobbin, is used as the yarn feed bobbin in FIG. 1, a large quantity of fluff is produced at a yarn rewinding portion A or at a tenser portion B due to contact between yarn portions or contact between the yarn and the tenser portion. In such fluffing portions there are provided covers 19 and 20 to cover those portions.
The following description is now provided about covers for the bobbin with reference to FIGS. 1 to 6.
In FIGS. 1 and 2, a bracket 22 is fixed with bolts 23 to a frame 21 of the winding unit and a pair of covers 19a and 19b are connected to the bracket 22 through a shaft 24 pivotably for opening and closing motion.
In a closed state the covers 19a and 19b are in a generally square shape in plan view as in FIG. 2, while in an open position indicated by dash-double dot lines 19al and 19bl the covers are spaced away from bobbin passages 25 and 26, providing no obstacle to the discharge of the bobbin from the take-up position and taking-in of a new bobbin to the take-up position indicated at 27.
Such a square shape in transverse section of
covers 19a and 19b as in FIG. 2 is advantageous in that a rising air current is easily developed in the gap of each corner portion and so fluff rises smoothly
Further, the contact of ballooning yarn with the cover is less than that with a cylindrical cover, so the resistance and damage to the yarn are reduced.
One cover 19a is fixed to a pivotable member 28 which is pivotally supported by the fixed shaft 24, and an actuating rod 29 is connected to one end of the pivotable member 28. Likewise, the other cover 19b is fixed to a pivotable member 30 which is pivotally supported by the shaft 24, and a rod 31 is connected thereto. Numeral 32 denotes a stopper for defining the closed positions of the covers 19a and 19b.
Therefore, the rods 29 and 31 for opening and closing the covers 19a and 19 move in directions opposite to each other. More specifically, as shown in FIG. 3, the rod 29 for the cover 19a and the rod 31 for the cover 19b are connected to both end portions of a lever 34 which is pivotable about a single shaft 33 as a fulcrum. The lever 34 moves integrally with a rod 35 and a lever 36 both adapted to move in the direction of arrow 35 in accordance with a bobbin change command. A spring 37 shown in FIG. 2 is located to prevent damage of the lever 36 and the like.
The construction of the covers 19a and 19b will be described below. Since both covers are symmetric
In FIGS. 4 to 6, the cover body 19a is integrally formed by die casting of aluminum for example so that a vertically central portion is almost constant in sectional area, the upper portion gradually decreases in sectional area and the sectional area of the lower portion also becomes smaller downwards. The central portion, indicated at 38, covers the surface of the yarn layer on the feed bobbin. One side face of the cover 19a is formed with a mounting portion 40 for the mounting of a balloon guide 39 disposed inside the cover. The opposite side face is formed as a mounting portion 41 for the pivotable member 28.
As shown in FIGS. 1, 2, 7 and 8, the balloon guide 39, which is formed by cutting a part of a cylinder, comprises one semi-cylindrical body 42 fixed to one cover portion 19a of the opening/closing cover and the other semi-cylindrical body 43 fixed to the other cover portion 19b. A cylindrical body 44 is integrally formed above the semi-cylindrical body 43 and three blades 45, 46 and 47 are fixed onto the cylindrical body 44 toward the center. The balloon guide 39 is formed so that during travel of the yarn, the yarn passes through a gap 47 formed centrally by the blades as a balloon throttling portion, while when a yarn end in the central bore of the bobbin is blown up, the yarn easily passes through a large interblade gap 48. 50 are formed in the central portions of the covers 19a and 19b, that is, in the portions which cover the yarn layer portion of the bobbin. A transparent member is fixed to each said window so that the residual yarn can be seen from the exterior during the winding operation.
During winding of the yarn in the device of the above construction, as shown in FIGS. 1 and 9, the yarn being unwound at high speed is located inside the covers 19a and 19b, so that the fluff formed with unwinding of the yarn is sucked into the pipe 3 through a suction pipe 51 connected to the cover 20 which covers the upper tenser portion as shown in FIG. 9, and thereby removed without scattering. At the time of bobbin replacement, the covers 19a and 19b open to the dashdouble dot positions in FIGS. 2, thereby permitting easy replacement of bobbin.
According to the present invention, as set forth above, the fluff produced by rewinding of the yarn is prevented from being scattered by the covers 19a and 19b which cover the yarn feed bobbin.
The following is an explanation about the case where a balloon guide is provided outside the covers 19a and 19b.
Embodiments in which a balloon guide is provided outside of the covers 19a and 19b will be described hereinafter.
Where the take-up rate of the winder is high, the conventional types of balloon guides are insufficient at the point of the formation of balloon. When the yarn layer on the feed bobbin decreases and in this condition the yarn is rewound from the lower yarn layer of the bobbin, a large rewinding tension will be imposed on the yarn, which may cause breakage of the yarn or slip-off of a part of the yarn layer called sloughing.
To resolve the inconvenience it is preferred to use a balloon guide of the present invention. The balloon guide is formed with a tapered throttling portion in a predetermined internal position of a cylindrical body.
An embodiment of the balloon guide of the present invention will be described hereinunder with reference to the drawings.
FIG. 14 shows an example of a winding unit. This embodiment is applied to a winder of the type wherein bobbins 107 are fitted on coveying trays 110 separately from one another and in this state they are supplied to winding units. But it goes without saying that the invention is also applicable to a winder of the type wherein each winding unit has a magazine and bobbins are supplied to the magazines from a conveyor laid along the winding units.
In FIG. 14, a winding unit 101 is supported pivotably by a pivot shaft 103 of a side frame 102. During operation of the automatic winder, the winding unit 101 is also placed on and suitably fixed to a suction pipe 104. The winding unit 101 is provided with a spinning bobbin supplying device 105 in a lower position. The spinning bobbin supplying device 105 has inclination toward the front of the machine frame. It functions to receive a new spinning bobbin 107 from a spinning bobbin supplying conveyor belt 106 disposed along the back of the machine frame and discharge an empty bobbin 108 after the completion of winding of yarn to a package in the take-up position onto an empty bobbin discharging conveyor belt 109. Each bobbin is fitted upright on a tray 110 as an independent and separated conveyance medium. The tray 110 comprises a disc-like base 111 and a peg 112 projecting centrally from the base 111. A conduit communicating with an upper air passing port 113 is provided, extending to the lower surface of the base. A take-up position is determined at a suitable part of the spinning bobbin supplying device 105 and in this position the yarn on the spinning bobbin is wound up to a package 115. A pressurized air conduit communicating with a pressure source (not shown) is disposed under the take-up position of the bobbin supplying device 115 where a bobbin 116 lies, and a nozzle 118 at the tip end thereof is opposed to the conduit in the tray 110. As shown in FIG. 14, a front yarn end 119 of a new spinning bobbin 107 hangs down through the interior of a take-up tube 120.
Over the top of the bobbin 116 located in the take-up position there is supported a cylinder 121 to the winding unit 1 by means of a support member on the same virtual axis as the bobbin 116.
FIGS. 10 to 13 illustrate embodiments of the above cylinder or a balloon guide 121, of which FIGS. 10 and 11 illustrate a first embodiment wherein the balloon guide 121 is of an integral construction of a cylindrical body 123 and a throttle member 124 is fixed in the interior of the cylindrical body.
The throttle member 124 comprises a central, yarn passing hole 125 and upper and lower tapered surfaces 126 and 127. As the case may be, a pressurized air injection nozzle 128 is formed in the upper tapered surface 126 of the throttle member. At the time of yarn joining operation, the yarn end 119 in the central bore of the bobbin is blown upward by the air ejected from the nozzle in FIG. 13 positioned under the tray, and is sucked and held by a stand-by relay pipe.
The cylindrical body 123 extending below the throttle member 124 of the balloon guide 121 is set to a length sufficient to fit on the bobbin 116 in the rewinding position. In the normal winding state the yarn which is unwound from the bobbin travels upward while ballooning. In this case, the balloon expands in the presence of the throttle member 124 and the angle between the yarn being unwound and the yarn layer surface, namely, the angle between the axis of the bobbin and the yarn travelling direction, becomes large, thus resulting in improvement in the yarn rising performance, whereby the occurrence of sloughing and fluff can be suppressed. Further, since the cylindrical body 123 covers the upper end portion of the bobbin, even when the yarn is unwound from the lower portion of the bobbin in a decreased volume of the yarn layer, the balloon, indicated at Y1, expands and so the separation of the yarn being unwound from the yarn layer surface indicated at 116a can be done smoothly. Consequently, it is possible to prevent a sudden increase of tension; in other words, the breakage of yarn under increased tension as well as sloughing can be prevented until the end of unwinding of the yarn.
Referring now to FIGS. 12 and 13, there is illustrated a second embodiment. In this embodiment, a cylindrical body 129 is internally formed with a throttle portion 130 which comprises a plurality of generally triangular blades 131, 132 and 133. These blades are mounted in the axial direction of the bobbin. In the drawing, three blades are disposed to form a central, yarn passing hole 134. The yarn enters the yarn passing hole 134 through and between adjacent blades. For example, in a sucked-up state of the yarn end, the yarn passes through a space Sl formed by the blades 131 and 133 and an inner peripheral wall 129a and is blown upward sucked and held by the relay pipe As the yarn begins to travel, it gets into the central hole 134 through a gap 135 between the blades 131 and 133 under the action of its ballooning which is in a clockwise direction in FIGS. 12 and 13, and thus the winding unit assumes the normal winding state. Also in this embodiment an auxiliary air nozzle 136 is open into the cylindrical body 129, which nozzle is effective in the case of a thick yarn and when the distance between the upper end portion of the bobbin and the lower end portion of the cylindrical body 129 is large.
Further, in the foregoing first embodiment (FIG. 10), the cylindrical body has the tapered surface 127 above the bobbin, so this throttled portion can be an obstacle to the blowing-up of the yarn and 119 and to the passing of fluff. This point is overcome in the second embodiment (FIG. 12) and since there are formed large spaces S1, S2 and S3 between adjacent blades, the blowing-up of the yarn end and the passing of fluff during take-up are effected extremely smoothly and balloon is throttled by the throttle portion 130. Thus, the same effect as in the first embodiment is exhibited.
In FIG. 14, the numeral 137 denotes a relay pipe, which is supported pivotably about a hollow shaft 138. The relay pipe 137 has a tip end formed as an opening 139 for sucking the yarn end from the bobbin, and the hollow shaft 138 is connected to a suction device (not shown). When the relay pipe pivots and the bobbin yarn end suction port 139 approaches the top of the bobbin 116 located in the take-up position, suction is effected for the yarn end. Numeral 140 denotes a yarn joining device, numeral 141 denotes a suction mouth on the package side, and numeral 142 denotes a slub catcher. In supplying the bobbin on the tray 110 to the rewinding position in the winding unit, as shown in FIGS. 10 and 12, the cylindrical body 121 as a bisplit cylindrical body opens along the center thereof to take in the bobbin to the rewinding position. Alternatively, the balloon guide may be retracted upwards.
In the present invention, as set forth above, since a balloon guide having a cylindrical body and a throttle portion is disposed to cover the upper portion of a yarn feed bobbin, the formation of the balloon is improved and, thus it is possible to prevent a sudden increase of tension and sloughing even when the yarn layer decreases in volume. | In a winder, a cover is provided at a portion of the winder where fluff is very likely to occur; that is, the portion is the position of a yarn feed bobbin, and the cover operates to cover this portion, thereby enclosing the fluff therein, and a suction pipe is connected to a part of the cover to discharge the fluff by suction. | 3 |
This application is a continuation of application Ser. No. 07/099,048, filed Sep. 21, 1987, now abandoned.
BACKGROUND OF THE INVENTION
The present invention is directed to semiconductor devices such as transistors and the like, and more particularly is concerned with the modification of surface fields in the active regions of the devices.
The electrical field which inherently exists at the surface of an active region of a semiconductor device influences one or more of the operating characteristics of that device. For example, in an MOS field effect transistor, the field which exists at the interface of the gate oxide and the active channel region determines the threshold voltage of the device and the mobility of carriers. When the active channel region is comprised of doped silicon and the gate oxide comprises silicon dioxide, the nature of this interface is that it always has a positive charge. As a result, an n-channel MOS device typically operates in a depletion mode. It is desirable to be able to introduce a stable negative charge at the interface of the silicon and the gate oxide, to thereby reduce the positive field that exists at this interface and produce a more neutral device, or even an enhancement mode device.
Similarly, in bipolar transistors it is desirable to operate with low collector currents to thereby reduce power requirements. However, the low current gain of the transistor is affected by the recombination of carriers at the surface of the base region. This recombination is dependent upon the field which exists at this surface. If this field can be appropriately controlled, the surface recombination velocity can be influenced to bring the low current cutoff of the transistor lower.
Accordingly, it is desirable to be able to control the electric field that exists at the surface of a material in a monolithic device. In particular, it is desirable to be able to lower the net positive charge that is inherently present at the interface of a dielectric material and a semiconductor material.
BRIEF STATEMENT OF THE INVENTION
In accordance with the present invention, these objectives are achieved through the placement of atomic or molecular species within the crystal structure of a dielectric material. In a preferred embodiment of the invention, these species are selected from the group of alkaline earth metals. Placement of a constituent selected from this group at a location within the dielectric, but close to the interface of the dielectric material and the semiconductor material, results in an electronic density redistribution that donates electronic density to the structure. This change in electronic density contributes to a reduced positive interfacial charge or, in some cases, a negative effective interfacial charge.
The additive species must be placed sufficiently close to the interface that this reduction in the net charge is exhibited in the interfacial field. However, since the atoms of the alkaline earth metals contribute electrons to the structure, each atom has a net positive charge associated with it, i.e., it becomes a positive ion. Therefore, these ions must be at a distance from the interface that their net positive charge is insulated from the field at the interface, thereby permitting the electronic density shift to the other atoms in the structure to predominate.
In the preferred method, the species is introduced into the dielectric structure through ion implantation followed by thermal activation, such as annealing. The energy of the ion implantation process should be chosen such that the projected range of the implanted species insures that its distribution peak is on the dielectric side of the dielectric/semiconductor interface after the thermal activation. Preferably, the thermal activation comprises a multi-step annealing process. In the first step, the structure is annealed at a relatively low temperature, e.g. less than 600° C., in a non-oxidizing atmosphere. Subsequently, an anneal is carried out at a much higher temperature, e.g., in the range of 900-1100° C., in the same or a different non-oxidizing atmosphere. Either or both of these steps can be repeated to repair lattice damage as desired.
As an alternative, the species can be introduced into the host dielectric matrix through the ion cluster beam (ICB) technique. With this approach, both the host matrix and the additive species can be produced with good control of the deposition rate and stoichiometry.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the present invention and the advantages offered thereby are described in the following examples, and experimental results relating to these examples are illustrated in the accompanying figures.
FIG. 1 is a cross-sectional view of an MOS capacitor.
FIG. 2 is a collector/voltage (C/V) graph illustrating the capacitance of an MOS capacitor having various concentrations of calcium and krypton implanted into its oxide.
FIGS. 3a and 3b represent the C/V characteristics of another example of the invention prior to annealment and after a final annealing step, respectively.
FIGS. 4a and 4b are SIMS diagrams illustrating the distribution of calcium in the substrate before and after annealing.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the following description of examples of the invention, particular reference is made to MOS structures, where such reference facilitates an understanding of the invention. It will be appreciated, however, that the applicability of the invention is not limited to this particular type of structure. Rather, the field modification that is achieved with the present invention can be employed in bipolar devices as well as MOS structures.
Briefly, the basic principle underlying the present invention is the modification of surface fields in semiconductor structures through the placement of atomic species within a host lattice at a location in the vicinity of the surface of the host material. More particularly, the present invention is directed to the reduction, and more preferably polarity inversion, of the interfacial field between a dielectric material and a semiconductor material. In accordance with the invention, this reduction can be achieved by placing atoms of elements from groups 1a, 2a or 3a of the Periodic Table of Elements in a host dielectric structure. Since each of these elements has a relatively small number of valence electrons, it will readily donate electronic density to the structure. Therefore, by placing atoms of these elements at the dielectric/semiconductor interface, a net reduction of the positive electric charge can be achieved.
In the case of group 1a and group 3a elements, however, it has been found that the particular lattice site for the constituent is critical to the attainment of the desired results. More particularly, through theoretical modeling it has been found that placement of the group 1 elements sodium and potassium at one interstitial site of two linked oxide crystal cells will result in a negative effective charge at the surface of the material, but placement of these same elements at a different interstitial site will result in a net positive charge. In particular, placement of an atom at interstitial site 2, which is the site defined by the coordinates (-1.5258, 0, 4.3288) in two linked beta-cristobalite cells, results in the negative effective charge, but placement at site 1, which is the site having the coordinates (0, 0, 4.3288), results in the positive effective charge. Thus, to attain a net reduction in the field at the surface of the host material, it is necessary to ensure that the additive species are located at the proper lattice site. This critical dependence upon the particular site for placement of the atomic species is believed to be similarly applicable to group 3 elements.
In contrast, however, the alkaline earth metals of group 2a provide substantially increased results relative to site placement. For example, calcium exhibits a negative effective charge at all three available interstitial sites, although the magnitude of the charge is greatest if the calcium is located at site 2. Experimental results indicate that strontium and barium also produce negative effective charges regardless of the particular site location. Accordingly, the alkaline earth metals are the most preferred species for placement in a dielectric structure, since net reduction of the surface field is not dependent upon site placement.
The following examples are provided to illustrate the behavior of devices resulting from the implantation of calcium into silicon dioxide structures.
EXAMPLE I
Layers of oxide were thermally grown on wafers of 6-9 ohm-cm n-type 100 silicon. The average thickness of the oxide layers was 770 angstroms±10 angstroms.
The wafers were divided into three groups. One group of wafers was implanted with calcium at a dose of 1×10 12 cm -2 . A second group of wafers was implanted with calcium at a dose of 1×10 13 cm -2 . A third group, which functioned as the control group, was implanted with krypton at a dosage of 1×10 13 cm -2 . The implant energies were chosen so that the predicted range (R p ) for each implant would be in the oxide near the SiO 2 /Si interface.
All of the samples were then annealed in the following sequence:
1. 450° C. for 40 minutes in a forming gas comprised of 80% N 2 and 20% H 2 .
2. 1100° C. for 30 minutes in pure nitrogen.
3. 450° C. for 40 minutes in the forming gas.
MOS capacitors each having a silicon dioxide dielectric 10 interposed between an aluminum gate 12 and the silicon substrate 14, as shown in FIG. 1, were then constructed with each wafer. The capacitance of each capacitor was measured at a frequency of 1 MHz at room temperature and at a biased temperature of 300° C.
The results of these measurements are indicated in the capacitance-voltage (C/V) diagram of FIG. 2. As can be seen from the figure, the higher dose calcium implant shifts the capacitance of the structure to the right with respect to the lower dose calcium implant. Basically, the structure behaves as though an additional fixed negative charge is present at the dielectric/semiconductor interface.
The reduced capacitance curve resulting from the 10 13 cm -2 krypton implant coincides with the lower dose calcium curve. This data establishes the fact that the shift to the right which is found for the higher dose calcium implant is not due to lattice damage. Since krypton is more massive than calcium, a change in capacitance due to damage would have produced higher results for the krypton than for the equivalent dose of calcium.
EXAMPLE II
Layers of oxide were grown on silicon wafers. The wafers were SEH, 100, p-type, 11-18 ohm-cm substrates and SEH, 100, n-type, 5-9 ohm-cm substrates. The oxide layers were grown with dry HCl process at 900° C. to a thickness of 750 angstroms.
The samples were implanted with calcium at respective doses of 10 12 , 10 13 and 10 14 cm 2 . The implant energy was chosen at 70 KeV so that R p was about 560 angstroms. This depth insured that the distribution peak of the calcium remained on the oxide side of the silicon dioxide/silicon interface after annealing.
MOS capacitors were formed, and the samples were annealed in the following sequence:
1. 450° C. for 20 minutes in a mixture of 90% N 2 and 10% H 2 .
2. 750° C. for 30 minutes in pure nitrogen.
3. 450° C. for 20 minutes in a mixture of 90% N 2 and 10% H 2 .
4. 905° C. for 30 minutes in pure nitrogen.
5. 450° C. for 20 minutes in a mixture of 90% N 2 and 10% H 2 .
6. 500° C. for 20 minutes in a mixture of 90% N 2 and 10% H 2 A control group of samples, which did not have calcium implanted into the oxide, was annealed in the same manner. The capacitance-voltage characteristics of the samples were measured at high frequency (about 100 KHz) after each anneal step using a non-destructive mercury probe technique. Between each anneal, the samples were cleaned in a boiling H 2 O 2 /H 2 SO 4 solution to remove any trace of mercury.
Table I below shows the change in a relevant parameter of the implanted samples, V min , as a function of the various anneals, relative to the control group. V min represents the voltage at which the MOS structure is inverted and hence corresponds to the threshold voltage for a long-channel transistor. Therefore, this value directly senses the total charge at the structure at the inversion point. This parameter was chosen instead of the flat band voltage V fb for the structure, since it is easier to identify.
TABLE I______________________________________ V.sub.min Shifts Associated with CalciumImplant into SiO.sub.210.sup.13 Ca.sup.+ /cm.sup.2 implant into 750 Å oxide ANNEALS #1 #2 (#3 + #4) #5 #6______________________________________V.sub.min -5.7 -6.2 -1.0 +0.4 +0.8V.sub.min 0 0 0 0 0(control)______________________________________
The C/V data for the implanted samples prior to annealing and after the final anneal are illustrated, respectively, in FIGS. 3a and 3b.
The data contained in Table I indicates a maximum shift in V min of 7.0 volts, i.e., (+0.8-(6.2)). These shifts are in the positive direction for each anneal. Thus, the total field charge is becoming less positive (more negative). Examination of the practical C/V data illustrates that the maximum error in the location of V min is ±0.15 volts. Thus, the shifts in V min illustrated in Table I are so large, compared to either the uncertainty in the V min value or the maximum voltage that could be attributed to lattice damage, that the conclusion represented by the data is that the charge exchange is associated with the calcium atoms during the annealing procedure.
The samples implanted with the calcium also exhibit a low dissipation factor (D) of about 0.03, in contrast with that of the control sample, which is about 0.2. This parameter provides a good measure of the quality of the oxide in the MOS capacitor. The data indicates that the presence of the calcium atoms does not increase the resistive losses within the structure which might have been expected on the basis of damage to the oxide/silicon interface.
To provide optimum contribution to the change in the interfacial field, the species added to the dielectric should be located near, but not at, the interface. If located at the interface, the positive ions which result when the additive species give up a valence electron would cancel the effect which the free electrons have on the field. Thus, the implanted ions should be located at least two atomic layers away from the interface, and preferably be in the range of 2-20 atomic layers from the interface, to isolate them from the surface field. The implant energy should be chosen so that the implanted species becomes located within this range of distances from the interface after final processing.
EXAMPLE III
Samples having oxide layers with a thickness of 750 angstroms were implanted with calcium at a dosage level of 10 14 cm -2 and an implant energy of 70 KeV, as in Example II. The distribution of the calcium was determined using secondary ion mass spectroscopy (SIMS). The results of this determination are shown in FIG. 4a.
The samples were then annealed in the following sequence:
1. 500° C. in 90% N 2 , 10% H 2 for 40 minutes;
2. 950° C. in 100% N 2 for 30 minutes;
3. 500° C. in 90% N 2 , 10% H2 for 40 minutes.
The distribution of the calcium was again determined, and the SIMS data is shown in FIG. 4b.
A comparison of the data shown in FIGS. 4a and 4b reveals that the distribution of the calcium is substantially unaffected by the annealing process. Thus, the energy level for the implant process can be chosen so that Rp falls within the final range of desired locations for the additive species.
Since atoms of the alkaline earth metals strontium and barium are larger in size than those of calcium, they are less mobile than calcium in the silicon dioxide lattice structure. Accordingly, they are more stable and contribute even higher electronic density to the system.
It will be appreciated by those of ordinary skill in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. For example, the placement of the additive atomic species in the dielectric can be accomplished with an ion cluster beam (ICB) in place of ion implantation. With this technique the host lattice would be produced by means of the beam, and the additive ion introduced by switching to a different source in the beam generator.
The presently disclosed examples of the invention are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalence thereof are intended to be embraced therein. | Reduction in the net charge at the interface of a dielectric and a semiconductor material is achieved by placing atomic species in the dielectric near the interface. Preferably, these species are selected from the group of alkaline earth metals. The presence of these atoms results in a redistribution of the electronic density near the interface. The placement of the atoms is effected by ion implantation followed by multiple annealing steps at alternating low and high temperatures. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an aqueous ink for ink jet printing by use of a dot printer and for use with ball point pens and fountain pens.
Conventionally, there is known an aqueous ink for ink jet printing in which a halogenated xanthene-type dye having the following formula (I) is employed: ##STR3##
Although the above dye has an excellent color tone and high solubility in water and polyhydric alcohols, it has the shortcoming that it fades significantly when exposed to light.
There is also known an aqueous ink for ink jet printing in which another xanthene-type dye having the following formula (II) is employed: ##STR4## wherein R 1 and R 2 each represent ##STR5## (in which R 5 , R 6 , R 7 and R 8 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt); R 3 and R 4 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt; and k, l, m and n each represent an integer of 0, 1 or 2.
The above dye having the formula (II) does not fade when exposed to light since it has high light resistance, but the color tone is slightly inferior to the first mentioned dye and the solubility in water and polyhydric alcohols is not as high as the first mentioned magenta dye.
Generally, it is preferable that magenta dyes have high special absorption peaks in a wavelength range of 500 nm to 600 nm. However, most magenta dyes have also spectral absorption in the base of the absorption curves, for instance in the ranges of from 400 nm to 500 nm and from 600 nm to 700 nm and because of such spectral absorption, the color tone of such magenta dyes is not good. A magenta dye having a sharp peak in the first mentioned wavelength range, however, is somehow vulnerable to light and fades easily when exposed to light. Therefore it is not suitable for use as a dye of an ink jet printing ink.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an aqueous magenta ink for ink jet printing which is particularly improved with respect to the color tone and light resistance as compared with conventional aqueous magenta inks.
According to the present invention, the above object is attained by an aqueous ink comprising a mixture of the previously discussed magenta dyes having the following formulas, a water-soluble organic solvent having a boiling point of 100° C. or higher, water and a preservative and anti-mold agent: ##STR6## wherein R 1 and R 2 each represent ##STR7## (in which R 5 , R 6 , R 7 and R 8 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt); R 3 and R 4 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt, and k, l, m and n each represent an integer of 0, 1 or 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As mentioned previously, the dye having the formula (I) has high solubility in water and polyhydric alcohols and is excellent in color tone, but has poor light resistance. The dye having the formula (II) has excellent light resistance, but the solubility in water and polyhydric alcohols is not high and the color tone is slightly inferior.
Since the affinity between the dye of the formula (I) and the dye of the formula (II) is high and the dye of the formula (I) is very soluble in water and polyhydric alcohols, a mixture of the dye of the formula (I) and the dye of the formula (II) is highly soluble in water and polyhydric alcohols and significantly resistant to light, possibly because the dye of the formula (II) having high light resistance protects the dye of the formula (I) when they are mixed. As a result, this mixture is suitable as a magenta dye composition for ink jet printing.
It is preferable that the mixing ratio of the dye of the formula (I) to the dye of the formula (II) in terms of part by weight be (1:3) to (3:1) and the total amount of the two dyes in the aqueous ink according to the present invention be in the range of 2.0 wt. % to 5.0 wt. % of the entier weight of the aqueous ink.
As the water-soluble organic solvent having a boiling point of 100° C. or higher, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols (having a molecular weight of about 200, about 300 and about 400) and glycerol and mixtures thereof can be employed. When the boiling point of such organic solvents is below 100° C., the solvents readily evaporate from the ink composition, so that the nozzles are plugged with the solid components of the ink during a non-use period.
As the preservative and anti-mold agents, for example, 2,2-dimethyl-6-acetoxy-dioxane-1,3-dehydrosodium acetate, p-hydroxy benzoic acid butyl ester, potassium sorbate, 2-pyridine thiol-1-oxidesodium salt, anionic surface active agents, Deltop 33 (commercialy available from Takeda Chemical Industries Ltd.), and Bioside 880 (commercially avaialbe from Taisho Co., Ltd.) can be employed.
Further it is preferable that the pH of the aqueous ink according to the present invention be in the range of about 9.7 to about 10. If the pH is less than 9.7, the ink absorbs a CO 2 gas contained in the air, so that the pH of the ink is decreased and the metallic portions (for instance, made of Ni) of the nozzles are corroded with time.
Specific examples of the dye of the formula (II) for use in the present invention are as follows: ##STR8##
By referring to the following examples, the present invention will now be explained in detail.
EXAMPLE 1
A mixture of the following components was prepared:
______________________________________ Parts by Weight______________________________________Magenta dye (I) 2.5Magenta dye (II)-1 1.0Glycerol 10Diethylene glycol 10Preservative and anti-mold agent 0.5(Deltop 33 commercially available fromTakoda Chemical Industries, Ltd.Ion-exchanged water 75______________________________________
To the above mixture, a small amount of sodium carbonate was added so that the pH of the mixture was adjusted to be 10. The mixture was heated to 70° C., stirred at the same temperature for 4 hours and then filtered through a membrane filter with a 0.22 μm mesh, whereby an aqueous ink No. 1 according to the present invention was prepared.
EXAMPLE 2
A mixture of the following components was prepared:
______________________________________ Parts by Weight______________________________________Magenta dye (I) 2.5Magenta dye (II)-3 1.5Glycerol 20Diethylene glycol 25Preservative and anti-mold agent 0.5(Deltop 33 commercially available fromTakoda Chemical Industries, Ltd.Ion-exchanged water 60______________________________________
To the above mixture, a small amount of sodium hydroxide was added so that the pH of the mixture was adjusted to be 9.7. The mixture was heated to 70° C., stirred at the same temperature for 4 hours and then filtered through a membrane filter with a 0.22 μm mesh, whereby an aqueous ink No. 2 according to the present invention was prepared.
EXAMPLE 3
A mixture of the following components was prepared:
______________________________________ Parts by Weight______________________________________Magenta dye (I) 1.5Magenta dye (II)-4 1.0Magenta dye (II)-6 2.0Glycerol 25Diethylene glycol 20Preservative and anti-mold agent 0.5(Deltop 33 commercially available fromTakoda Chemical Industries, Ltd.Ion-exchanged water 50______________________________________
To the above mentioned, a small amount of sodium hydroxide was added so that the pH of the mixture was adjusted to be 9.8. The mixture was heated to 70° C., stirred at the same temperature for 4 hours and then filtered through a membrane filter with a 0.22 μm mesh, whereby an aqueous ink No. 3 according to the present invention was prepared. cl Comparative Example 1
A mixture of the following components was prepared:
______________________________________ Parts by Weight______________________________________Magenta dye (I) 3.5Glycerol 10Diethylene glycol 10Preservative and anti-mold agent 0.5(Deltop 33 commercially available fromTakoda Chemical Industries, Ltd.Ion-exchanged water 75______________________________________
To the above mixture, a small amount of sodium carbonate was added so that the pH of the mixture weas adjusted to be 10. The mixture was heated to 70° C., stirred at the same temperature for 4 hours and then filtered through a membrane filter with a 0.22 μm mesh, whereby a comparative aqueous ink No. 1 was prepared.
Comparative Example 2
A mixture of the following components was prepared:
______________________________________ Parts by Weight______________________________________Magenta Dye (II)-1 3.5Glycerol 10Diethylene glycol 10Preservative and anti-mold agent 0.5(Deltop 33 commercially available fromTakoda Chemical Industries, Ltd.Ion-exchanged water 75______________________________________
To the above mixture, a small amount of sodium carbonate was added so that the pH of the mixture was adjusted to be 10. The mixture was heated to 70° C., stirred at the same temperature for 4 hours and then filtered through a membrane filter which a 0.22 μm mesh, whereby a comparative aqueous ink No. 2 was prepared.
The thus prepared aqueous inks No. 1 through No. 3 according to the present invention and the comparative aqueous inks No. 1 and No. 1 and No. 2 were subjected to the following tests:
Test 1
100 g of each aqueous ink was filtered through a 0.5 μm mesh membrane filter under a pressure of 2 atm and the time t 1 required to filter the ink through the membrane filter was measured. Each ink, without being filtered, was preserved for 2 months at a cooling and heating cycle of -10° C. for 12 hours and 40° C. for 12 hours. After this preservation test, the ink was filtered through the same membrane filter in the same manner as mentioned above and the time time t 2 required to filter the ink was measured and the increased percentage of the time required for filtering the ink after the preservation test to the time required for filtering before the preservation test, that is,
(t.sub.2 -t.sub.1)/t.sub.1 ×100%
was calaculated.
Test 2
The same aqueous ink was charged in 10 ink jet heads each having one nozzle having a diameter of 40 μm, and was caused to issue from the ink jet heads with a pressure of 3.5 kg/cm 2 and with vibrations at a frequency of 100 KHz to a sheet of plain paper which was placed at a distance of 30 mm from the nozzles, whereby the first ink-impinging position was determined. The ink was allowed to stand at 40° C., 30% RH for 2 months without being used for subjecting the ink to a non-use test. After this non-use test, the ink was again caused to issue from the 10 ink jet heads to the plain paper under the same conditions as mentioned above, so that the second ejected position was determined. Thus the deviation of the second ink-impinging position from the first ink-impinging position was obtained.
Test 3
The density d 1 of an image printed on the plain paper in the above Test 2 was first measured and the image was exposed to light by a carbon arc lamp at 40° C., 80% RH for 5 hours, so that the image density d 2 of the image exposed to the light was measured. The percentage of the decrease in the image density after the exposure, that is,
(d.sub.1 -D.sub.2)/d.sub.1 ×100%
was obtained.
The results of the above tests are summarized in the following table:
TABLE______________________________________Aqueous Test 1 Test 2 Test 3Ink (%) (μm) (%)______________________________________No. 1 4 40 8No. 2 7 25 6No. 3 5 18 7Comp. Ink 21 23 35No. 1Comp. Ink 26 145 5No. 2______________________________________
In Test 1, it is preferable that the percentage of the increase in the filtering time be not more than 10%.
In Test 2, it is preferable that the derivation be not more than 100 μm.
In Test 3, it is preferable that the fading ratio be not more than 10%.
The results in the above table indicate that the aqueous inks according to the present invention are far better in the preservability, ejection stability and light resistance than the comparative aqueous inks in which not a combination of the magenta dye of the formula (I) and the magenta dye of the formula (II), but either the magenta dye of the formula (I) or the magenta dye of the formula (II) was employed. | An aqueous ink is disclosed, which comprises a first magenta dye having the formula (I), a second magenta dye having the formula (II), a water-soluble organic solvent having a boiling point of 100° C. or higher, water and a preservative and anti-mold agent: ##STR1## wherein K.and R 2 each represent ##STR2## (in which R 5 , R 6 , R 7 and R 8 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt); R 3 and R 4 each represent a lower alkyl group, an amino group, a sulfonic acid group in the form of an alkali metal salt, or a carboxyl group in the form of an alkali metal salt; and k, l, m and n each represent an integer of 0, 1 or 2. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation in part of U.S. patent application Ser. No. 12/898,835 filed on Oct. 6, 2010 entitled “Absorbency Pad for Use in Neonatal Care and Related Method of Use,” the contents of which are incorporated by reference herein, and claims priority to U.S. Provisional Patent Application Ser. No. 61/248,982 filed on Oct. 6, 2009 entitled “Perforated Absorbency Pad for Use in Neonatal Care,” the contents of which are incorporated by reference herein.
FIELD OF THE INVENTION
This invention is directed toward an absorbency pad for use with low birth weight or unstable infants incubated in a neonatal intensive care unit that reduces the amount of contact with the infant and a related method of use.
BACKGROUND OF THE INVENTION
Premature birth, also commonly known as preterm birth, occurs when the infant is born after less than 37 weeks of gestation. Statistically, premature infants are at a greater risk of short- and long-term complications, including impediments in growth and mental development. Long term health effects resulting from preterm birth can include cerebral palsy, blindness, lung disease, and learning disabilities. While the underlying cause of preterm birth is generally unknown, many factors appear to be associated with premature birth, making reduction of this health risk challenging.
In most developed countries and in Europe, the preterm birth rate is generally between 5 to 9 percent. However, in the United States, the rate has risen to an alarming 12 to 13 percent over the last several decades. In fact from 1990 to 2005, premature births in this country have risen over 20 percent. This translates to roughly 500,000 preterm births each year.
There are several classifications of preterm birth, based largely upon the gestational age and birth weight. A low birth weight infant (LBW) refers to any infant weighing less than 5 pounds, 8 ounces. A very low birth weight infant (“VLBW”) includes an infant born less than 3 pounds, 5 ounces. Finally, an extremely low birth weight infant (“ELBW”) is an infant who weighs less than 2 pounds, 2 ounces. Each year, approximately 40,000 ELBW infants are born in the United States.
Most hospitals in developed countries maintain neonatal intensive care units (“NICUs”) capable of treating preterm infants, as well as low birth weight infants (including VLBW and ELBW infants) or any infant requiring hospital intervention. Highly trained and specialized nurses who are capable of treating neonatal infants staff these NICUs. Most NICUs keep neonatal infants in specialized incubators that create a confined and isolated environment to provide regulated temperature and proper life support and respiratory systems.
When treating neonatal infants, especially VLBW and ELBW infants, most NICUs attempt to reduce or even eliminate physical contact as much as possible for the first 72 hours after birth (once these infants are placed into an incubator or onto a radiant warmer and connected to life support, respiratory systems and monitors). This is because these neonatal infants have extremely fragile skin, high sensitivity to touch, and are at a larger risk of intraventricular hemorrhaging (a rupturing of the capillaries in the brain, which can be caused in part in handling low birth weight infants).
Due to these risks, doctors and nurses try to adhere to a minimal stimulation protocol by clustering care, for example, to allow babies longer periods of rest. Currently, however, there is no simple or safe way to change neonatal bed linens. Instead, it is simply common practice to place an absorbent cotton blanket in the incubator (or on the radiant warmer) prior to treating the neonatal infant. Once a blanket becomes soiled with blood, urine, feces or materials used to treat the neonatal infant (i.e., betadine or saline), they are removed from the incubator or radiant warmer. This typically occurs through briefly lifting the neonatal infant, removing the soiled blanket and positioning a new and clean blanket (requiring multiple staff assisting in this process).
There are multiple drawbacks with this current system commonly used in NICUs. First, the brief relocation of the neonatal infant to remove the soiled blankets can cause trauma, bruising or even possible intraventricular hemorrhaging. Second, repositioning the neonate to remove the soiled blanket risks extubation of endotracheal tubes required for ventilation, which can cause damage, injury or even death to the neonate—or at the very least severe discomfort. Finally, even with removal of the top layered blanket, there is a risk that some secretion of fluid may seep onto the underlying incubator (or radiant warmer). Upon removal of the top cotton blanket, the neonatal infant is still exposed to this fluid, risking infection.
Accordingly, there is a need in the art of treating neonatal infants—especially those with VLBW and ELBW—or any unstable newborn within an incubator or radiant warmer to reduce the amount of physical contact with NICU personnel. Moreover, there is a need in the art to manufacture bed barriers that allow removal of soiled bed blankets without disrupting or moving the neonatal infant to reduce the risk of trauma and/or injury.
SUMMARY OF THE INVENTION
The present invention contemplates an essentially planar neonatal pad comprising a contact layer having a top side and a bottom side with a substantially medial perforation extending longitudinally to promote ease of separating the contact layer into a first panel and a second panel. The contact layer is selected from the material group comprising acrylics, high density polyethylene, low density polyethylene, polyester, polyolefins, polyurethanes, polyurethane-polyurea copolymers, rayons, spunbond polypropylene, and blends of these materials. In an alternate embodiment, the contact layer comprises material containing silver nano-particulates.
An absorbency layer is positioned to underlie the bottom side of the contact layer, and comprises a first half and a second half, the first half abutting the second half proximate the medial perforation of the contact layer to define an absorbency layer cleavage. The absorbency layer is generally coextensive with the contact layer to receive fluids passing through the contact layer, and is operable for dispersing and containing fluid within the neonatal pad. The pad is substantially rectangular in shape having an upper edge, a lower edge, a left side and corresponding right side.
The absorbency layer is selected from the material group comprising acrylics, bamboo, cellulose materials, cotton, high density polyethylene, low density polyethylene, polyester, polyolefins, polyurethanes, polyurethane-polyurea copolymers, rayons, superabsorbent polymers, wools, and blends of these materials.
A waterproof barrier layer having a top side and a bottom side is positioned to underlie the absorbency layer. The barrier layer comprises a first half and a second half, the first half abutting the second half proximate the absorbency layer cleavage to define a barrier layer cleavage that is generally coextensive with the contact layer. The absorbency layer is sandwiched between the contact layer and the waterproof barrier layer.
The waterproof barrier layer is selected from the material group comprising acrylics, spun bound high density polyethylene, high density polyethylene, layered low density polyethylene film, low density polyethylene, polyester, polyolefins, polyurethanes, polyurethane-polyurea copolymers, polytetrafluoroethylene, spunbond polypropylene, and blends of these materials.
A sealing pull strip having an anchoring end and a pull tab end is removably adhered to the top side of the barrier layer along the barrier layer cleavage to maintain the first half of the barrier layer in a position adjacent to the second half of the barrier layer. The pull strip underlies the absorbency layer, wherein the pull strip is a sufficient length to traverse substantially the length of the barrier layer along the barrier layer cleavage and maintain a fold in the pull strip to double back across the length of the barrier layer. The pull tab end of the pull strip extends beyond a first edge of the barrier layer. The purpose of the pull strip is to hold the barrier layer cleavage together until the pull strip is pulled away from the barrier layer so to disengage the first half of the barrier layer from the second half of the barrier layer.
In a preferred embodiment, the contact layer is bonded to the absorbency layer, and the barrier layer is bonded to the absorbency layer.
At least one handle tab is attached to the bottom side of the barrier layer, and protrudes past a second edge of the barrier layer substantially opposite the first edge of the barrier layer, the handle tab providing a handle for a user to hold for the purpose of stabilizing the neonatal pad while the pull strip tab end is being pulled.
The invention also comprises a method of maintaining a neonatal infant, the method comprising the steps of: placing a first pad assembly onto a bed portion of a neonate incubator; adding at least one additional pad assembly under the first pad, the additional pad having an essentially similar construction as the first pad; placing a neonatal infant on the first pad assembly; determining whether the first pad assembly has become soiled by the neonatal infant; pulling a pull strip of the first pad assembly to separate the first pad assembly into a first half, a second half, and an unattached pull strip; removing the first half of the first pad assembly from the incubator without picking up the neonatal infant; removing the second half of the first pad assembly from the incubator without picking up the neonatal infant; and exposing the adjacent additional pad assembly to the neonatal infant.
A preferred embodiment includes the step of holding a handle tab to assist in stabilizing the first pad assembly while the pull strip is being pulled from the first pad assembly.
A preferred embodiment of the method of treating a neonatal infant described herein specifically includes the utilization of the neonatal pad described above.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is made to the following detailed description, taken in connection with the accompanying drawings illustrating various embodiments of the present invention, in which:
FIG. 1 is a schematic illustration of a top view of a preferred embodiment of the invention;
FIG. 2 is a schematic illustration of a side cutaway view of the invention illustrated in FIG. 1 ;
FIG. 2A is a close-up schematic illustration of a side cutaway view of the indicated region of FIG. 2 .
FIG. 3 is a schematic illustration of a side cutaway view of the invention illustrated in FIG. 1 ;
FIG. 4 is a schematic illustration of a side cutaway view of the invention illustrated in FIG. 1 ;
FIG. 5 is a schematic illustration of an isometric view of the invention in use inside a neonatal incubator;
FIG. 6 is a schematic illustration of an isometric view of the invention in use;
FIG. 7 is a schematic illustration of an isometric cutaway view of the pull strip being removed from the pad assembly;
FIG. 8 is a close up schematic illustration of a side view of the pad assembly after the pull strip is removed from the pad assembly; and
FIG. 9 is a schematic illustration of an isometric view of the invention in use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternate embodiments.
The Pad Assembly
Referring initially to FIG. 1 , the invention is directed to a pad assembly 100 . Referring next to FIG. 2 and FIG. 2A , the pad assembly 100 comprises a plurality of layers including a contact layer 120 , a first absorption layer panel 122 a , a second absorption layer panel 122 b (collectively referred to as the absorption layer 122 ), and a barrier layer 124 . As shown in FIG. 1 , the pad 100 is essentially rectangular and includes an upper edge 101 , a lower edge 102 , a left side edge 103 , and a right side edge 104 . Moreover, the pad 100 is of a sufficient size and dimension to be placed and maintained within a NICU incubator.
As further illustrated in FIG. 1 , located approximately in the middle of the pad assembly 100 is a perforation 106 capable of being separated that, upon separation, divides the contact layer 120 into a first panel 108 and a second panel 110 . The perforation 106 extends from the upper edge 101 to the lower edge 102 . By pulling the left side edge 103 of the pad 100 apart and away from the right side edge 104 , the perforation 106 allows the first panel 108 to detach from the second portion 110 .
Referring to FIG. 1 , and to FIG. 1 of U.S. patent application Ser. No. 12/898,835, in one embodiment, the pad assembly 100 includes a depiction of a ruler or similar measuring device located on the contact layer 120 . Such ruler preferably includes a wetness indicator. Once a neonatal infant (N) ( FIG. 6 ) is placed onto the pad 100 , her height is measured through use of the ruler without moving or disturbing the infant (N), thus reducing risk of trauma and/or injury to the infant (N). In one embodiment, the pad assembly 100 comprises a thermo-indicator that allows detection of a fever and/or sudden change in body temperature. For example, should the neonatal infant (N) maintain a temperature above average, a thermo-chemical located on the pad assembly 100 will turn a distinct color to alert medical personnel of a potential medical issue. It is contemplated that one embodiment includes areas proximate the outer edges 101 , 102 , 103 , 104 of the contact layer 120 include regions of colored material (for example, the color green) that may be calming or soothing to the neonatal infant (N), and therefore useful for chromotherapy holistic healing and generally pleasing aesthetics. The contact layer 120 of the pad assembly 100 includes a recording area. The recording area provides a space for a medical professional to denote current medical information relating to the neonatal infant (N). Such medical information includes at least one of the patient name, date of birth, time of birth, weight, measurements (including head circumference, chest circumference, abdominal girth, length), pulse, respiratory rate, blood pressure, temperature, and location of intravenous access, and any other medically relevant information.
The Contact Layer
As illustrated in FIG. 1 , FIG. 2 and FIG. 2A , the pad assembly 100 comprises a contact layer 120 . The contact layer 120 is preferably positioned at the top surface of the pad assembly 100 such that it is the layer that interacts with the neonatal infant (N). Thus, the contact layer 120 must be capable of allowing a variety of bodily fluids such as urine, feces, blood and other effluvia to pass through the contact layer 120 so the bodily fluids are absorbed by the absorption layer 122 . This contact layer 120 must also be resistant to degradation mediated by bodily fluids and those fluids used during medical care, such as betadine, saline, alcohols, oil-based ointments, and any other liquids found in a medical environment.
Preferably, the contact layer 120 is manufactured from a soft, smooth and non-stick material. While such layer is non-abrasive and hypoallergenic, the contact layer 120 should be designed such that is not too slippery. Several materials can be used for the contact layer 120 including both woven and non-woven materials which are at least one of natural fibers, synthetic fibers, and combinations thereof. In a preferred embodiment, the contact layer 120 is made from 0.5 ounce spunbond polypropylene, which exhibits advantageous filtration properties, high tensile strength, and excellent chemical resistance. In one embodiment, the contact layer 120 is a blend of polymer fibers which are coated with polytetrafluoroethylene (Teflon™) or a similar non-stick material. In another embodiment, interdisbursed throughout the polymer fibers are nano-silver particulates. Such nano-silver particulates help to reduce bacterial and microbial build-up on the contact layer 120 due to their bacteriostatic and antimicrobial properties. It is important to note that the addition of nano-silver particulates to the contact layer 120 does not render the pad 100 incompatible for x-ray or similar imaging procedures.
As shown in FIG. 1 , the contact layer 120 includes a perforation 106 such that the contact layer can be split into two panels 108 and 110 for removal away from the neonate infant (N). The bottom side of the contact layer 120 includes an adhesive material sufficient to engage the absorption layer 122 . The bottom side of the contact layer 120 includes an adhesive material sufficient to engage the barrier layer 124 .
The Absorption Layer
Still referring to FIG. 2 , in addition to a contact layer 110 , the pad assembly 100 also preferably comprises an absorption layer 122 . The absorption layer 122 is positioned to underlie the bottom side of the contact layer 120 . Preferably, the length and width of the absorption layer 122 is substantially coextensive with the contact layer 120 . In a preferred embodiment, both the contact layer 120 and absorption layer 122 are bonded to each other.
The absorption layer 122 is preferably made of natural fibers, woven together, capable of absorbing various fluids. Alternatively, the absorption layer 122 can be manufactured from a high absorbency synthetic material. Regardless of structure (fill or fiber, woven or non-woven), it is preferable that the natural fiber be made out of bamboo due to its high absorbency and antimicrobial properties. However, other natural fibers such as merino wool and cotton are also contemplated. The absorption layer 122 is therefore made from at least one of bamboo, cotton, wools, spandex, and polyester. The materials are in the form of terry, double loop terry, fleece, jersey, flannel, batting, thermal, weave, interlock, rib, and combinations thereof.
The absorption layer 122 is of two-part construction such that it comprises a first panel 122 a and a corresponding second panel 122 b . The first panel 122 a abuts the second panel 122 b proximate the perforation 106 of the contact layer 120 . A cleavage point 126 is defined by the joint where the first half of the absorption layer 122 abuts the second half of the absorption layer 122 . The cleavage point 126 is the location where the absorption layer 122 separates into two separate halves upon breaking the perforation 106 of the contact layer 120 and separating the contact layer into two panels 108 , 110 .
It is also contemplated that a variety of thermo-chemicals, known to those of ordinary skill in the art, be utilized in the pad assembly 100 , proximate the absorption layer 122 , to create warmth for a neonatal infant (N) in addition to the warmth provided by the incubator.
The absorption layer 122 and the contact layer 120 can also act as treatment vehicles by the inclusion of compounds to help treat and/or prevent injury and infection to the neonatal infant (N). These medicines can include, but are not limited to, antibacterial agents (e.g. as Benzalkonium Chloride 0.1%), antiviral agents, antifungal agents, antiparasitic agents, moisturizing agents, and any other compounds known to help treat and/or prevent injury and infection, and combinations thereof.
The Barrier Layer
Still referring to FIG. 2 and FIG. 2A , the barrier layer 124 is positioned to underlie the bottom side of the absorption layer 122 . Preferably, the length and width of the barrier layer 124 is substantially coextensive with the contact layer 120 . In a preferred embodiment, both the barrier layer 124 and absorption layer 122 are bonded to each other.
The barrier layer 124 is preferably made of a waterproof material such as low density polyethylene bonded to 0.8 ounce spun bond polypropylene. Alternatively, the barrier layer 124 is made from at least one of acrylics, spun bound high density polyethylene, high density polyethylene, layered low density polyethylene film, low density polyethylene, polyester, polyolefins, polyurethanes, polyurethane-polyurea copolymers, polytetrafluoroethylene, spunbond polypropylene, and blends of these materials. The barrier layer 124 prevents liquids present in the absorption layer from passing below the barrier layer 124 .
The barrier layer 124 is of two-part construction such that it comprises a first barrier panel 124 a and a corresponding second barrier panel 124 b . The first barrier panel 124 a abuts the second barrier panel 124 b proximate the cleavage point 126 of the absorption layer. A barrier cleavage 128 is defined by the joint where the first half of the barrier layer 124 a abuts the second half of the barrier layer 124 b . The barrier cleavage 128 is the location where the barrier layer 124 significantly separates the barrier layer 124 into two separate panels 124 a , 124 b upon breaking the perforation 106 of the contact layer 120 and separating the contact layer into two panels 108 , 110 .
The Pull Strip
A sealing pull strip 130 having an anchored end 132 and a pull tab end 134 , as illustrated in FIG. 1 , is removably adhered to both the first barrier panel 124 a and the second barrier panel 124 b , along the length of the barrier cleavage 128 . The pull strip 130 seals the barrier panels 124 a , 124 b together so that the barrier cleavage 128 is watertight, thus preventing any liquids from passing beyond the barrier layer 124 . The adhesive to adhere the pull strip 130 to the barrier panels 124 a , 124 b is preferably a low-tack, pressure-sensitive adhesive.
As illustrated in FIG. 1 , FIG. 3 , and FIG. 4 , the pull strip 130 is a sufficient length to traverse the length of the barrier cleavage 128 , and fold over 136 on itself and double back across the length of the pad assembly 100 . The pull tab end 134 protrudes beyond the lower edge 102 of the pad assembly 100 . The pull strip 130 is sandwiched above the barrier layer 124 and below the absorption layer 122 . Pulling the pull tab end 134 away from the pad assembly 100 causes the pull strip 130 to release from the barrier panels 124 a , 124 b so that the barrier panels 124 a , 124 b are free to separate from each other at the barrier cleavage 128 . To anchor the pad assembly 100 when pulling the pull strip 130 from the assembly 100 , a handle tab 136 is attached to bottom side of the barrier layer proximate the upper edge 101 of the assembly 100 .
Method of Use
As illustrated in FIG. 5 , a plurality of pad assemblies 100 are stacked upon each other. These assemblies 100 are placed into a neonate incubator. This provides the bottom bedding for a neonatal infant (N). A determination is made as to whether the pad assembly 100 directly below the neonatal infant (N) is soiled by the neonatal infant (N) or from fluids used during medical care, such as betadine, saline, alcohols, oil-based ointments, and any other liquids found in a medical environment.
FIG. 6 illustrates a person pulling the pull strip 130 from the pull tab end 134 . As further illustrated by FIG. 7 , pulling the pull tab end 134 away from the pad assembly 100 causes the pull strip 130 to release from the barrier panels 124 a , 124 b so that the barrier panels 124 a , 124 b are free to separate from each other at the barrier cleavage 128 . The pull strip 130 is then discarded.
FIG. 8 illustrates the pad assembly 100 after the pull strip 130 has been removed from the assembly 100 . The barrier cleavage 128 is made free from the pull strip 130 , and the barrier panels 124 a , 124 b may be separated from each other. At this point the pad assembly 100 is a single assembly that is being held together solely by the perforation 106 in the contact layer 120 .
FIG. 9 illustrates the pad assembly 100 being separated into two halves. The perforation 106 is ripped separating the pad the contact layer 120 into a first panel 108 and a second panel 110 . At this point, the pad assembly 100 is three discrete pieces: a pull strip 106 that has been disengaged from the assembly 100 , a first half of the pad assembly 100 a and a second half of the pad assembly 100 b . The first half of the pad assembly 100 a and the second half of the pad assembly 100 b are removed from below the neonatal infant (N), and the next clean and dry pad assembly 100 on the stack is revealed. The neonatal infant (N) need not be lifted to be exposed to clean bedding.
Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims. | The invention is directed to a planar pad manufactured from three layers, each layer made from materials of differing properties. A contact layer being safe for a neonatal infant's skin is the top layer. The middle layer is an absorption layer positioned immediately below the contact layer. The absorption layer is of a two-part construction having a first half and a corresponding second half which abuts the first half. The absorption layer is operable for dispersing and containing fluids within the pad. The bottom layer is a waterproof barrier layer which is posited directly below the absorbency layer, preferably constructed of flashspun high-density polyethylene, and is also a two part construction. An internal pull tab maintains the pad in a single assembly. Upon removing the pull tab, the pad assembly splits into two separate assembly halves. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates principally to improving dewatering of a fibrous web by applying steam to the web, typically just as it passes over a vacuum box. In particular, the invention relates to a method and apparatus capable of adjusting the moisture content of a paper web on a paper machine in the cross machine direction to achieve a uniform moisture profile.
2. Review of the Prior Art
It is well known in the art of papermaking to employ steam showers or boxes to improve suction dewatering of pulp and paper webs at various locations on the paper machine. Such showers are especially useful at the "wet end" or forming sections of the paper machine where the web typically exceeds 50 percent moisture content by weight. They are also useful in improving press section dewatering.
A typical steam box impinges dry, saturated or superheated, steam onto the traveling web. The web, supported on a forming wire or drying felt, is simultaneously subjected to a vacuum. The vacuum pulls the steam into the sheet interior where it condenses, giving up its heat of condensation to the water content of the web. The increase in temperature dramatically lowers the viscosity and surface tension of the water content of the web, resulting in a more thorough extraction of water for a given vacuum.
The use of a steam hood generally decreases the overall moisture level of the web, across its entire width. It is the experience of papermakers, however, that significant non-uniformity of moisture content across the width of the web may occur which adversely affects paper machine operation. For example, on a typical machine, the outer edges of the web may be at three percent moisture in comparison with a seven percent moisture content at the center of the web.
It is further the experience of papermakers that various defects in machiney or in its operation in the forming section of a paper machine result in "wet streaks" or areas that have relatively high moisture content with respect to surrounding web areas. Wet streaks may also originate in the press machine section when portions of the press felts become plugged because of faulty felt cleaning shower systems. These streaks appear at unpredictable locations across the width of the web. Wet streaks can run for days before the source of difficulty is found.
The moisture profile uniformity of the web as it leaves the forming section determines to a large extent uniformity in finished paper at the reel. This is so because conventional pressing and can drying are not usually designed to correct local web nonuniformity across the paper machine width.
The speed of the entire machine may be determined by a wet streak, even if only two inches wide. Compensation for one or two regions of wet streaking will often necessitate a reduction in overall water content of the web by several percent in order to build an acceptable reel. These effects on machine speed and steam consumption thus have an important impact on the profitability of the papermaking operation.
The prior art describes a number of schemes for attempting to control the sheet moisture profile in the cross machine direction. Compartmentalized steam hoods, for example, shower a wet streak with extra steam in an effort to reduce overall variability and the potential for rejection at the reel for failure to meet maximum water content specifications.
Dupasquier, in the U.S. Pat. Nos. 3,726,757 and 3,795,578, describes a steam shower divided into 11 compartments across the width of the paper machine, each equipped with a separate steam flow valve. A vacuum box, opposite the shower and under the machine wire, draws steam into the web across the entire width of the machine. Chari et al. "Profile Analysis for Evaluation of a Compartmentalized Steam Box," TAPPI Annual Meeting Preprint (Mar. 15, 1976) describes operation of the Dupasquier hood. The object of the hood is to improve the basis weight and moisture profile by indiviudally controlling steam flow to each compartment. The Chari experiment shows that the profiling steam hood is effective in reducing long-term, cross machine moisture profile variation. The Dupasquier hood resulted in a total reduction of variance of moisture content of approximately 40 percent from a base line value without any significant change in bone dry fiber profiles.
Shelor, U.S. Pat. No. 3,516,607 and Dove, U.S. Pat. No. 3,945,570 also show compartmented steam boxes. In Dove, a portion of the steam is applied across the entire width of the web and another portion of steam is sent through compartmented sections over the web. Shelor is an example of many methods which control the flow of steam into each steam box or compartments by means of a flow control valve.
There are a number of problems with valve-controlled systems. Since typical boxes extend across the width of the web, which may be from 80 to 390 inches, as many as 65 valves may be used. This requires bulky structural systems suspended over the web to support the weight of the heavy valves of the box. Conventional hardware is heat sensitive and thus subject to excessive maintenance problems. Air controlled valves require plastic diaphragms which are so heat sensitive that desuperheated steam must be used. These valves also require pressure regulators, gauges and long control lines, all of which add to the complexity and unreliability of the resulting system.
A principal problem, however, is that the separately valved compartmented boxes lack precision in control. The amount of steam passing through the valve is often unknown and must be determined by means other than merely adjusting the valve control means.
In Wells, U.S. Pat. No. 4,249,992, a method and apparatus was disclosed which avoids a number of valving difficulties by varying the steam discharge opening of each compartment to the web, thus regulating the amount of steam absorbed by the web. These hoods are useful, but require rather complex, unique internal structures which are somewhat bulky and thus unsuitable for use in some mill locations.
SUMMARY OF THE INVENTION
It is an object of the invention herein to provide a steam shower or box which avoids the valving problems of the prior art and is capable of producing a uniform moisture profile across the width of a fibrous sheet.
It is further an object of the invention to provide a simplified control scheme suitable for modifying existing plenum-type steam hoods or boxes and for use in other mill applications such as in press sections where installation spaces are narrow.
The apparatus of the invention is generally used where it is an advantage to apply steam to a fibrous web traveling continuously through a process involving dewatering such as, for example, in forming, pressing, or otherwise treating a paper web. The apparatus includes a plenum extending across the width of the web for delivering substantially non-turbulent constant pressure steam adjacent to the web. A louver or steam outlet control means receives the steam from the plenum and delivers it onto the web. The amount of steam received by the web varies across its width, depending upon its local moisture content. The louver control means includes a plurality of side-by-side compartments across the width of the machine, each extending from the plenum close to the traveling web. Each compartment includes a damper capable of regulating the flow of steam from the plenum onto the adjacent web. The damper is adjusted to achieve the desired impact on the web at the particular point of application.
The machine operator is usually seeking to achieve a uniform moisture profile across the width of the web. The operator first observes or senses the average moisture content of the web adjacent the discharge of each hood compartment. The operator then adjusts the damper means for each compartment to achieve the overall uniform profile. After some time he re-observes the condition of the web and readjusts the damper means as necessary.
The damper is much like a butterfly valve, including a damper blade which, depending upon its position, controls flow through the compartment between no flow and a maximum. The damper blade is fixed to an axial means pivotally mounted in the compartment walls such that the damper blade is free to rotate about its axis. A control rod is attached either to the damper blade or the axial means and extends to an operating side of the paper machine for adjustment by the machine operator.
A number of means may be used to control the damper position such as pneumatic operators, gears and the like. Typically, a spring means positions the damper in a closed position until there is positive control action causing it to open.
The profiling apparatus of the invention is particularly useful in adjusting the moisture profile of a paper web on a forming wire. Its relatively small dimensions and compact shape are such that it is also useful in controlling the moisture profile of a paper web in the press section of a paper machine. In neither case will steam flow from the box disrupt the paper sheet itself.
BRIEF DESCRIPTION OF THE DRAWINGS OF THE PREFERRED EMBODIMENTS
FIG. 1 is an oblique view of a steam hood of the invention supplying steam to the forming section of a paper machine.
FIG. 2 is a sectional end view of a portion of the louver-control system.
FIG. 3 is a detailed plan view of a portion of the damper control means.
FIG. 4 is a graph showing steam added as a function of damper blade position.
FIG. 5 shows water removal as a function of steam added.
FIG. 6 shows the use of pneumatic controls to regulate damper positions.
FIG. 7 shows a double-damper blade control system.
FIG. 8 is a schematic showing an apparatus of the invention utilized in a press section of a paper machine.
FIG. 9 is a plan view of the press section apparatus louver control means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1-3, the preferred louvered moisture profiling steam box apparatus 10 of the invention is shown applying varying quantities of steam to a cellulosic web W transported on forming wire 11 across a vacuum box (not shown) under the wire. A plenum 12 is filled with substantially non-turbulent superheated steam flowing from an apertured steam pipe 13 extending across the width of the paper machine. The apertures 14 of the pipe 13 are sized to produce "choked flow" conditions, resulting in uniform flows of steam into the plenum 12 regardless of minor steam pressure variations locally along the distributor pipe 13. The velocity of the steam discharging from the orifices is dissipated by expanding into a triangular shaped plenum through a stainless steel wool packing 15 surrounding the pipe discharge orifices 14. The resulting non-turbulent steam completely fills the steam hood plenum at substantially atmospheric pressure.
The plenum discharges its steam into a louver control means 16 as shown in FIG. 2. The louver control means 16 includes a series of adjacent compartments 17 which, side-by-side, extend across the width of the paper machine. As typical of many compartmented hoods, the width of the compartments is usually selected to duplicate forming slice widths of about 6 inches. The length of each compartment, in the machine direction, is selected so that in conjunction with width, enough steam can be delivered to the web to achieve the dewatering impact desired. A typical dimension is 36 to 60 inches. The walls 18, 19 of each compartment extend from the plenum adjacent to, as close as practicable, the traveling web. Clearances on the order of 0.5-1.0 inches is typical.
Each compartment 17 includes a damper 20 for controlling the amount of steam discharged from the plenum onto the web. The damper is a blade 21 having a shape and cross sectional area to substantially close off the compartment to the plenum when in a substantially horizontal position. The blade 21 is fixed to an axial rod 22 which is mounted in compartment cross machine side walls 19. The mounting is such that the axial rod is free to rotate, thus rotating the damper blade 21 position. sidewall stops 23 limit rotation of the blade as it reaches the horizontal or closed position where steam flow is closed off. The blade 21 is biased closed against the stops 23 by a spring 24.
A control rod system allows the operator at an operating side of the paper machine to position the damper in each compartment. The control rod system includes a lever arm 25 attached to each damper blade 21. A control rod 26 is pivotally fixed to the lever arm 25, exiting at right angles to the blade 21, to an operating side 27 of the steam box. The rod 26 terminates on the operating side with a threaded portion. A wing nut 28 threads onto the rod to secure the damper plate 21 in position, after it is set, against the tension of the biasing spring 24. The control rods 26 are spaced along the blades 21 in the machine direction so that there is no interference between compartments.
In operation, steam in the plenum 12 flows into the control compartments 17 that are open. Steam, in an amount in direct proportion to the discharge area opening, determined by the position of the louver blade 21, passes through into contact with the web. Where the open cross sectional area is reduced, the steam moves laterally through the plenum to a compartment which is more open. There are sufficient numbers of dampers such that the opening or closing of them does not significantly affect the hood plenum steam pressure.
In the embodiment shown in FIG. 2, the width of the damper blade 21 is selected so that the blade is within about 1/8 inch of the sidewalls. As the damper blade 21 is rotated by the control rod means, the discharge opening increases as the blade moves away from the wall surface 18. The opening increases sinusoidally with the degree of rotation. The result, as shown in FIG. 4, is that, since steam flow is directly proportional to the cross sectional area of the opening, the flow or "steam added" to the web increases very gradually as the damper blade 21 begins to open. This is advantageous because, as shown in FIG. 5, the impact of steam on the WEB, i.e., "water removed" is greatest for the first amounts of steam used.
The overall impact of the steam hood on the web may be adjusted by changing the steam pressure input to the plenum once the cross machine profile is established. The steam input to the plenum can be varied to maintain a desired moisture level at the reel.
With respect to width of the compartment discharge opening, the opening increases as the cosine of the angle of rotation of the damper increases. It is an advantage to carefully regulate the first few pounds added to the web since this steam has the most dramatic impact on dewatering. Thus, it appears desirable in most cases to cause the damper to open very slowly initially. On the other hand, operators likely would prefer a more linear relationship between rod adjustment and water removal. As shown in FIG. 2, the angles of the sidewalls may be adjusted to achieve a more linear relationship between the effect on sheet drainage and damper position, if desired. Experimental data show that the last 10 percent opening of the damper has a much greater effect than the last 10 percent opening of typical steam control valves used in prior art compartmented hoods.
There are many modifications to the basic louver control system described above which will be apparent to those skilled in the art. FIG. 6, for example, shows controlling damper positions using air cylinders 30. The cylinder piston rod 31 advances, in response to a control action, to cause lever arm 32, fixed to axial shaft 22, to rotate the damper blade 21. A spring 33 biases the damper 21 in the closed position. Use of air cylinders are useful for remote control arrangements.
FIG. 7 shows a variation in damper configuration in which each compartment 17 is supplied with two damper blades 21. A gear pair 35 mounted on the damper axial shafts 22 intermesh such that movement of control rod 26 causes both dampers to change position. The gears 35 are actually made by cutting a single gear in half and fixing them to the damper axial rod ends 22 to operate the dampers 21 through a 90° rotation. The double damper system in some cases helps uniformly distribute the steam onto the web. A small electric gear motor (not shown) may be fitted to one gear to provide remote electric operation.
As another variation in damper control configuration, a single blade could be pivoted at or close to one edge of the blade. This arrangement is useful in achieving a linear steam effect.
FIGS. 8 and 9 show a louvered steam hood 10' apparatus of the invention employed in a paper machine press section. The paper web W travels supported on felts 41 through a number of dewatering press nips 42. The press roll 43 includes a suction gland 44 across which the felt-supported web W passes. The louvered steam box 10' is urged adjacent the web to improve web moisture profile by application of steam to the web exactly as described above with respect to the paper machine forming section shown in FIGS. 1-3. FIG. 8 shows apertured steam pipe distributor 45 discharging steam under choked flow conditions through steel wool packing 46 into plenum 47.
As shown in FIG. 9, louver control means 48 includes compartments 49 across the width of the web and the louver blades 50. The discharge compartment walls 51 may be contoured somewhat to better direct the steam into contact with the web.
The steam hood works best where the plenum is located above the zone of steam discharge to the sheet. In this position, the non-turbulent substantially zero velocity steam tends to float and disperse throughout the plenum rather than flow into any particular compartment. If the plenum were underdeath the compartments, steam would rise and try to escape out the closest opening. If the steam were introduced at one end of the box, it would tend to flow out the first available opening. The tendency of steam to rise and flow sideways rather than downwards distributes the steam evenly throughout the plenum without depending upon a substantial pressure differential. The plenum must be large enough so that it always remains at an insignificant pressure, i.e., 1/20 of an inch of water, whether the louvers are open or closed. The damper clearances between the damper blade and the compartment walls are enough so that even if all the dampers are closed, there is enough leakage so that pressure in the plenum never exceeds 1 psig. No safety valves or vents are required.
EXAMPLE
A non-compartmented steam hood, comprising substantially the plenum portion of the hood shown in FIG. 1 installed on Weyerhaeuser's NC 2 paper machine, was converted to the louvered profiling steam hood of the invention by adding the louver control means 16 (FIG. 2), described above. The hood plenum was raised about 6 inches and the louver control means was fixed thereunder. A compartment width of 6 inches, equivalent to the paper forming section slice width of about 6 inches, was chosen. The machine direction dimensions of each compartment was 36 inches. There were 28 compartments across the width of the machine. The paper machine speed was 425 feet per minute, running Weyerhaeuser pulp grade "416 Atlantic". The steam distributor 13 of the box was operated at 45 psig.
The following data shows the effectiveness of the hood in controlling wet streaks. The test consisted of choosing a slice position with moderate moisture content with its damper in the middle of its range and adjusting the damper from fully closed to fully open. Slice 9 was selected, showing the following results:
TABLE______________________________________EFFECT OF DAMPER POSITION AT SLICE 9 - NC2. % MOISTURE COUCH SHEETDAMPER POSITION* AT REEL** TEMPERATURE______________________________________15/8" (Pre-trial) 6.1% 158°1" 7.8% --1/2" (Fully Closed) 8.6% 121° (Minimum)1" 7.1% 128° (Minimum)11/2" 6.3% 132° (Minimum)2" 5.7% 152° (Minimum)21/2" 5.5% 160°-170° (Range)3" 5.4% 168°-178° (Range)33/4" (Fully Open) 5.1% 193°-202° (Range)______________________________________ *Damper position given in inches of adjustment rod 26. **Average reading over 10 min. period after adjustment.
closing and opening the slice 9 damper resulted in the moisture contents of the sheet passing beneath the hood adjacent slice 9 varying between 8.6 percent (closed) to 5.1 percent (wide open). In a test similar to the above, a wet streak of 10.5 percent moisture content was reduced to 6.0 percent. There are certain variations of the mechanical elements of the invention that are obvious to thos skilled in the art and are included within the scope of this invention. For example, the louver control mechanism may consist of replacing the pull rods with choke cables or the entire linkage may comprise a wire cable operating around pulleys. The push rods themselves could be operated by gear motors positioning the louver according to voltage supplied to the motor. | A steam box or hood for controlling the moisture profile of a fibrous web such as paper during forming and pressing is described. The steam hood includes a plenum filled with nonturbulent, substantially atmospheric pressure steam which delivers the steam into a series of side-by-side compartments which extend across the width of and adjacent to the web. Each compartment includes a damper, the position of which is individually controllable through a rod adjustment from the operating side of the machine. The position of the damper determines the amount of steam applied to the web from a compartment and hence the moisture content of the web adjacent to the particular compartment being adjusted. Each compartment is adjusted to achieve a desired uniform moisture content across the width of the web. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Patent Application No. PCT/CN2011/080401 filed on Sep. 30, 2011, which claims the priority benefit of China patent application No. 201110222300.0, filed on Aug. 4, 2011. All of these related applications are incorporated herein by reference in their entirety and made a part of this application.
FIELD OF THE INVENTION
The present invention pertains to the technical field of high-performance organic fiber and specifically relates to a high-strength high-modulus polyimide fiber and its preparation method.
BACKGROUND OF THE INVENTION
Polyimide (PI) fiber as one type of high-performance fiber has high strength, high modulus, resistance to high temperature, low temperature and radiation and other high performances in addition to good biocompatibility and dielectric properties. Extensive application is expected in the fields of atomic energy industry, space environment, wrecking, aerospace, national defense, new-type buildings, high-speed vehicles, oceanic development, sports equipment, new energy, environmental industry and protection equipment.
The current methods for preparing PI fiber mainly include one-step method and two-step method. The technical route of the one-step method: A PI solution is used as a spinning solution. PI fiber is spin by wet method or dry-wet method. After preliminary drawing, the fiber possesses certain strength. After the solvent is removed, thermal drawing and thermal treatment (300° C.-500° C.) is conducted. High-strength high-modulus PI fiber may be obtained. This method features a simple spinning process, but in view of the current synthesis of PI, the common solvents are phenols. Phenol solvents (such as: cresol and p-chlorophenol) not only have high toxicity but also have a large residual amount in fiber. They can hardly be thoroughly removed. It is not good for environmental protection, resulting in difficulty in industrialization. Moreover, the technology of one-step method has very high requirement on the solubility of PI. This greatly reduces the corrosion resistance and heat resistance of PI fiber. Chinese invention patent ZL O2112048.X and American patents U.S. Pat. No. 4,370,290 and U.S. Pat. No. 5,378,420 all disclose a method for preparing PI fiber by one-step method. The technical route of two-step method: Firstly, the concentrated solution of polyamic acid (PAA) is sprayed by wet method or dry-wet method to obtain PAA fiber. Then the PAA fiber obtained in the first step is chemically or thermally cyclized to obtain PI fiber. For example, Japanese published unexamined patent applications JP3287815 and JP4018115 both adopt this method to prepare PI fiber. The advantage of this method: It solves the processing difficulty caused by the infusibility and insolubility of PI fiber, the synthetic raw materials and solvents have many types and low toxicity. The residual amount of the solvents in the fiber is low. It is suitable for industrial production. The disadvantage of this method: The mechanical property of PI fiber prepared by this method is low in general.
Chinese patent (Application No.: 200710050651.1) discloses a PI fiber with a benzimidazole structure and its preparation method. In this method, PAA spinning solution is prepared from 2-(4-aminophenyl)-1H-benzimidazol-5-amine (BIA) and diandhydrides at a molar ratio of 1:1, then the PAA spinning solution is spun to obtain PAA precursor and in the end the PAA precursor is thermally imidized to obtain PI fiber. Its tensile strength is 0.73˜1.53 GPa and initial modulus is 45.2˜220 GPa. Chinese patent application (application No.: 201010572496.1) discloses a PI fiber made from 3,3′,4,4′-biphenyl tetracarboxylic diandhydride (BPDA), p-phenylenediamine (pPDA) and 2-(4-aminophenyl)-1H-benzimidazol-5-amine (BIA) and its preparation method, specifically: p-PDA and BIA with a molar ratio of 0.8˜0.95:0.05˜0.2 and BPDA are dissolved in a solvent to obtain a PAA spinning solution. Then the PAA spinning solution is spun to obtain PAA fiber. Then the PAA fiber is dried, thermally cyclized and thermally drawn to obtain PI fiber. Its strength is 2.5 GPa. In the foregoing two methods, the mechanical property of PI fiber is improved both by adding BIA. Although the mechanical property is improved remarkably, it sill does not meet the performance requirements of high-strength high-modulus polyimide. Greater breakthrough and change in synthesis method and preparation process are needed.
SUMMARY OF THE INVENTION
The problem that the present invention needs to solve is to overcome the defects of the foregoing preparation methods, further improve the mechanical property of PI fiber and make it meet the performance requirements of high-strength high-modulus polyimide fiber.
The present invention provides a PI fiber obtained from random copolymerization of BPDA, pPDA and BIA. The molar ratio between pPDA and BIA is 1:10˜3:1. The tensile strength of the obtained PI fiber is 3.0˜4.5 GPa and initial modulus is 110˜201 GPa.
The foregoing PI fiber also includes the copolymerization with other diamine or/and dianhydride monomers. The molar ratio between the addition amount of other diamines and the total addition amount of pPDA and BIA is 1:10˜1:4. The molar ratio between other dianhydrides and biphenyl dianhydride is 1:10˜3:7.
These diamines and diandhydrides are all kinds of diamine and diandhydride monomers used by those of ordinary skill in the art to synthesize PI. Below is the general formula:
Where, R and R 1 stand for conventional structural groups in diamines and diandhydride monomers in the art, such as: aromatic groups and heterocyclic structures.
The present invention also provides a method for preparing the foregoing PI fiber, which includes the following steps:
A: pPDA, BIA and BPDA are proportioned at a molar ratio of 1:0.95˜1:1.05 between diamines and diandhydrides. The molar ratio between pPDA and BIA is 1:10˜3:1. B: A measured solvent is added to the diamines in Step A under the protection of N 2 to dissolve it. Then diandhydrides are added to make the solid content of the solution be 5˜35 wt %. After sufficient reaction, a PAA spinning solution is obtained. C: The PAA spinning solution is spin by wet or dry-wet spinning process. One-step continuous preparation method is adopted, i.e.: after a spinning solution is sprayed out from a spinneret plate, it continuously undergoes solidification in a coagulating bath, water scrubbing bath, treatment in heat furnaces at different temperature and fiber collection to obtain high-strength high-modulus polyimide fiber.
In the foregoing method, other diamines are also added in Step A. The molar ratio between the addition amount of other diamines and the total addition amount of pPDA and BIA is 1:10˜1:4. Other diandhydrides are also added in Step A. The molar ratio between other diandhydrides and BPDA is 1:10˜3:7.
In this method, the solvent used in Step B is dimethylformamide (DMF), dimethylacetamide (DMAc) or N-methyl pyrrolidone (NMP). The synthesis of a PAA solution adopts gradient temperature reaction. There are 2˜5 temperature sections. The temperature in each section is 75° C.˜−10° C. The reaction time varies with temperature sections. The total reaction time is 2˜20 h. The preferred gradient temperature is of successive decrease.
In the foregoing method, the bore diameter of the spinneret plate used in Step C is 00.045 mm-0.75 mm, the number of bores is 50˜2000, the coagulating bath and washing bath when wet or dry-wet process is adopted are one of water, methanol, ethanol, glycol, acetone, toluene, N,N-DMF (DMF), N,N-DMAc, NMP and dimethyl sulfoxide (DMSO) or a mixture of a few of them. There are at least four stages of heat furnaces in the one-step continuous preparation method, the temperature of each heat furnace is 80° C.-550° C., the draw ratio is 1˜2, the total furnace passing time is 5˜30 min, and the gas in the furnaces is air or nitrogen. Drawing at a ratio of 3˜7 is conducted when the temperature is above 400° C., and the gas in the furnaces is nitrogen. Preferably, the temperature of the four-stage furnaces is successively increased.
Compared with the prior art, the present invention has the following innovations and desirable effects:
1. The present invention adopts BPDA, pPDA, BIA and other diamines and diandhydrides to synthesize and prepare multi-component copolymer system PI fiber. By proceeding from the structure-performance relationship of PI fiber and through changing the molecular structure of PAA and increasing intermolecular and intramolecular forces, the optimal proportioning range of monomers is determined. The PI fiber prepared in this range has a more reasonable molecular structure and intermolecular force, thereby greatly improving the performance of PI fiber. 2. The present invention adopts a reaction method of nitrogen protection and gradient temperature, overcomes the difficulty that the reaction activity decreases with the increase of BIA content which leads to the small molecular weight and the uneasy spinning property of the obtained PAA, guarantees the appropriate molecular weight and spinning property of PAA while BIA content is greatly increased. The strength of the PI fiber may reach 4.5 GPa and its modulus may reach 201 GPa (the comparison with the PI fiber prepared by other techniques is shown in Table 1). The PI fiber has a fairly high performance/price ratio. With the popularization of raw materials and fall of price, the performance/price ratio of this fiber will be raised further. 3. The present invention adopts the one-step continuous preparation method. From PAA spinning solution, spinning, solidification, water scrubbing, thermal cyclization, thermal drawing to final fiber winding and collection, they are all within the one-step continuous process. Further, drawing the fiber to different extent in different stages facilitates the rearrangement and orientation of the molecular chains. The high degree of imidization and few defects ensure the problem of poor uniformity and stability of the fiber is solved while the fiber obtains high performance. This method significantly raises production efficiency, reduces production cost, enhances fiber performance and is very favorable to industrial production.
TABLE 1
Performance comparison between the PI fiber in the
art and the PI fiber in other prior arts
Performance
Type of PI fiber
Strength (GPa)
Modulus (GPa)
PI fiber in prior art 1
0.73-1.53
45.2-220
PI fiber in prior art 2
2.5
—
PI fiber in the art
3.0-4.5
110-201
The PI fiber in prior art 1 is the fiber obtained from Chinese patent (application No.: 200710050651.1). The PI fiber in prior art 2 is the fiber obtained from Chinese patent (application No.: 201010572496.1).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a surface morphology of the PI fiber in Embodiment 1 of the present invention by scanning electron microscopy (SEM).
FIG. 2 is a thermogravimetric analysis (TGA) chart of the PI fiber in Embodiment 2 of the present invention.
FIG. 3 is a dynamic thermomechanical analysis (DMA) chart of the PI fiber in Embodiment 2 of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
It should be noted that the following embodiments are intended to illustrate the present invention and not to limit the technical solutions described by the present invention. Therefore, although this Description describes the present invention in details in connection with the following embodiments, those of ordinary skill in the art should understand that modifications or equivalent replacements may still be made to the present invention; and all technical solutions and their modifications not departing from the spirit and scope of the invention should be within the scope of claims of the present invention.
Further, it should be noted that the structures of BPDA, p-PDA and BIA used in the following embodiment are shown below:
Embodiment 1
Synthesis of a PAA solution: At a molar ratio BPDA:pPDA:BIA=4.2:3:1, two diamine monomers P-PDA and BIA are put in a three-necked flask at first, then measured solvent DMF is added, P-PDA and BIA are stirred at 50° C. under the protection of nitrogen and are fully dissolved, then BPDA is added in batches and stirred to ensure its solid content is 10%. Then under the protection of nitrogen, it is stirred 2 h at 50° C., 1 h at 10° C. and 2 h at −5° C. to obtain a viscous PAA solution with intrinsic viscosity of 3.0 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a dry-wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 100; bore diameter: 0.15 mm), goes through an air layer (length: 50 mm) and then enters a coagulating bath (it comprises water and ethanol, with a volume ratio of 1:1) to form PAA fiber. After it is washed in a washing bath (comprising water), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 200° C., 260° C., 300° C. and 400° C. respectively and the draw ratio is 1.5, 1.2, 1.1 and 3.5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Where, m:n=1:3, its tensile strength is 3.4 GPa and initial modulus is 153.5 GPa. FIG. 1 indicates that there is a regular groove structure on the surface of the PI fiber prepared by this method, and the fiber may generate stronger conjugation with resin matrix and widely applied in the field of compound materials.
Embodiment 2
Synthesis of a PAA solution: At a molar ratio BPDA:pPDA:BIA=21:13:7, two diamine monomers P-PDA and BIA are put in a three-necked flask at first, then measured solvent DMAc is added, P-PDA and BIA are stirred at 70° C. under the protection of nitrogen and are fully dissolved, then BPDA is added in batches and stirred to ensure its solid content is 15%. Then under the protection of nitrogen, it is stirred 5 h at 70° C., 2 h at 20° C. and 3 h at 0° C. to obtain a viscous PAA solution with intrinsic viscosity of 2.5 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 50; bore diameter: 0.075 mm) and enters a coagulating bath (it comprises water) to form PAA fiber. After it is washed in a washing bath (comprising water), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 200° C., 280° C., 350° C. and 450° C. respectively and the draw ratio is 1.5, 1.3, 1.2 and 3.5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Where, m:n=7:13, its tensile strength is 4.5 GPa and initial modulus is 201.3 GPa. FIG. 1 indicates that there is a regular groove structure on the surface of the PI fiber prepared by this method, and the fiber may generate stronger conjugation with resin matrix and widely applied in the field of compound materials. FIG. 2 and FIG. 3 indicate that the glass-transition temperature (Tg) of the PI fiber prepared in this embodiment reaches 341.7° C. and the thermal weight loss temperature when mass loss is 10% is 573.1° C. in nitrogen and 564.1° C. in air, suggesting the PI fiber in the art has superior thermal performance in addition to high strength and high modulus.
Embodiment 3
Synthesis of a PAA solution: At a molar ratio BPDA:pPDA:BIA=4.75:2:3, two diamine monomers P-PDA and BIA are put in a three-necked flask at first, then measured solvent DMAc is added, P-PDA and BIA are stirred at 75° C. under the protection of nitrogen and are fully dissolved, then BPDA is added in batches and stirred to ensure its solid content is 20%. Then under the protection of nitrogen, it is stirred 2 h at 75° C., 3 h at 30° C. and 10 h at 0° C. to obtain a viscous PAA solution with intrinsic viscosity of 2.3 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 500; bore diameter: 0.045 mm) and enters a coagulating bath (it comprises water and DMAc, with a volume ratio of 7:3) to form PAA fiber. After it is washed in a washing bath (comprising water and ethanol, with a volume ratio of 1:1), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 180° C., 280° C., 300° C. and 400° C. respectively and the draw ratio is 1, 1, 1 and 5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Where, m:n=3:2, its tensile strength is 3.1 GPa and initial modulus is 165.2 GPa.
Embodiment 4
Synthesis of a PAA solution: At a molar ratio BPDA:ODA:pPDA:BIA=6:1:3:2, three diamine monomers ODA, p-PDA and BIA are put in a three-necked flask at first, then measured solvent DMAc is added, ODA, p-PDA and BIA are mechanically stirred at 50° C. under the protection of nitrogen and are fully dissolved, then BPDA is added in batches and stirred to ensure its solid content is 25%. Then under the protection of nitrogen, it is stirred 10 h at 50° C. and 5 h at −10° C. to obtain a viscous PAA solution with intrinsic viscosity of 3.1 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 500; bore diameter: 0.55 mm) and enters a coagulating bath (it comprises water and DMAc, with a volume ratio of 1:1) to form PAA fiber. After it is washed in a washing bath (comprising water and ethanol, with a volume ratio of 3:1), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 160° C., 270° C., 350° C. and 500° C. respectively and the draw ratio is 2, 1.5, 1.1 and 5.5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Where, m:n:s=2:3:1, its tensile strength is 3.7 GPa and initial modulus is 146.2 GPa.
Embodiment 5
Synthesis of a PAA solution: At a molar ratio BPDA:m-PDA:p-PDA:BIA=14.7:2:5:7, three diamine monomers p-PDA, m-PDA and BIA are put in a three-necked flask at first, then measured solvent NMP is added, PPDA, MPDA and BIA are stirred at 75° C. under the protection of nitrogen and are fully dissolved, then BPDA is added in batches and stirred to ensure its solid content is 20%. Then under the protection of nitrogen, it is stirred 8 h at 75° C., 3 h at 15° C. and 9 h at −10° C. to obtain a viscous PAA solution with intrinsic viscosity of 2.8 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 1000; bore diameter: 0.065 mm) and enters a coagulating bath (it comprises water and NMP, with a volume ratio of 3:1) to form PAA fiber. After it is washed in a washing bath (comprising water), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 180° C., 240° C., 300° C. and 550° C. respectively and the draw ratio is 1.8, 1.5, 1.3 and 6 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Where, m:n:s=7:5:2, its tensile strength is 3.6 GPa and initial modulus is 178.1 GPa.
Embodiment 6
Synthesis of a PAA solution: At a molar ratio BPDA:PMDA:p-PDA:BIA=7.4:1:1:7, two diamine monomers p-PDA and BIA are put in a three-necked flask at first, then measured solvent DMF is added, p-PDA and BIA are stirred at 40° C. under the protection of nitrogen and are fully dissolved, then BPDA and PMDA are added in batches and stirred to ensure their solid content is 15%. Then under the protection of nitrogen, it is stirred 8 h at 40° C. and 4 h at 0° C. to obtain a viscous PAA solution with intrinsic viscosity of 2.60 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a wet process. After the spinning solution is pumped out by a metering pump. It passes the spinneret plate (number of bores: 2000; bore diameter: 0.055 mm) and enters a coagulating bath (it comprises water and DMF, with a volume ratio of 5:3) to form PAA fiber. After it is washed in a washing bath (comprising water and ethanol, with a volume ratio of 2:1), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 180° C., 260° C., 300° C. and 500° C. respectively and the draw ratio is 1.5, 1.3, 1.1 and 5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Its tensile strength is 3.3 GPa and initial modulus is 126.4 GPa.
Embodiment 7
Synthesis of a PAA solution: At a molar ratio BPDA:ODPA:p-PDA:BIA=6:2.4:6:2, two diamine monomers p-PDA and BIA are put in a three-necked flask at first, then measured solvent DMAc is added, p-PDA and BIA are stirred at 25° C. under the protection of nitrogen and are evenly dispersed, then BPDA and ODPA are added in batches and stirred to ensure their solid content is 5%. Then under the protection of nitrogen, it is stirred 5 h at 25° C., 5 h at −10° C., 2 h at 10° C. and 2 h at 0° C. to obtain a viscous PAA solution with intrinsic viscosity of 2.78 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a dry-wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 1000; bore diameter: 0.1 mm), goes through an air layer (length: 30 mm) and then enters a coagulating bath (it comprises water and methanol, with a volume ratio of 1:1) to form PAA fiber. After it is washed in a washing bath (comprising water and ethanol, with a volume ratio of 2:1), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 180° C., 280° C., 350° C. and 480° C. respectively and the draw ratio is 1.4, 1.2, 1 and 5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Its tensile strength is 3.5 GPa and initial modulus is 141.7 GPa.
Embodiment 8
Synthesis of a PAA solution: At a molar ratio BPDA:BTDA:p-PDA:BIA=8.55:3:2:9, two diamine monomers p-PDA and BIA are put in a three-necked flask at first, then measured solvent DMF is added, p-PDA and BIA are stirred at 50° C. under the protection of nitrogen and are fully dissolved, then BPDA and BTDA are added in batches and stirred to ensure their solid content is 10%. Then under the protection of nitrogen, it is stirred 3 h at 50° C., 3 h at 10° C. and 5 h at 0° C. to obtain a viscous PAA solution with intrinsic viscosity of 2.56 dl/g.
Preparation of PI fiber: After the PAA solution is filtered and defoamed, it is spun by a wet process. After the spinning solution is pumped out by a metering pump, it passes the spinneret plate (number of bores: 2000; bore diameter: 0.045 mm) and enters a coagulating bath (it comprises water and DMF, with a volume ratio of 5:3) to form PAA fiber. After it is washed in a washing bath (comprising water and ethanol, with a volume ratio of 2:1), it directly enters the four-stage heat furnaces in turn. The temperature of the heat furnaces is 180° C., 280° C., 350° C. and 510° C. respectively and the draw ratio is 1.9, 1.3, 1.1 and 5.5 respectively. In the end, the yarn is wound into a roll to obtain PI fiber.
The structure of the obtained fiber is as follows:
Its tensile strength is 3.6 GPa and initial modulus is 152.1 GPa. | A high-strength high-modulus polyimide fiber and its preparation method pertain to the technical field of high-performance organic fiber. This fiber includes the polyimide (PI) fiber made from 3,3′,4,4′-biphenyl tetracarboxylic diandhydride (BPDA), p-phenylenediamine (pPDA) and 2-(4-aminophenyl)-1H-benzimidazol-5-amine (BIA), wherein the molar ratio between PPDA and BIA is 1:10˜3:1. During the synthesis, other diamine and diandhydride monomers may also be added. In the preparation process, the gradient temperature reaction method and one-step continuous preparation method are adopted, the synthesis and processing difficulty caused by the increase of the content of BIA is overcome, the problem of poor uniformity and stability of fiber is solved and PI fiber with high strength and high modulus is obtained. Its strength may reach 4.5 GPa and modulus may reach 201 GPa. Moreover, the sources of the raw materials are extensive, the spinning process is continuous, the cost is low, the efficiency is high and industrial production may be realized. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for preparing functionalized alkynes having internal triple bonds.
2. Description of the Related Art
The preparation of acetylenic compounds by bromination followed by dehydrobromination is known in the art. Fatty alkynes such as stearolic acid, palmitolic acid, behenolic acid, and ricinstearolic acid have been prepared from the corresponding olefinic fatty acids by bromination and dehydrohalogenation with alcoholic potassium hydroxide (Ann., 1866, 140, 39; Ann., 1867, 143, 27; Ann., 1867, 143, 41; Ann., 1865, 135, 226). Aqueous potassium and sodium hydroxides have also been used along with a polyethylene glycol catalyst in the dehydrohalogenation of internal vicinal dibromohydrocarbons to acetylenic hydrocarbons. (J. Org. Chem., 47, 2493, 1982). Aqueous sodium hydroxide has similarly been used in the presence of tetrabutyl ammonium bisulfate to eliminate vicinal dibromo-hydrocarbons to acetylenic hydrocarbons (Tetrahedron Letters, 1976, 4723). Solid potassium hydroxide in the presence of phase transfer catalysts such as quaternary amines (Aliquat 336, tetraoctyl ammonium bromide) or crown ethers (18-crown-6) has been used to accomplish the dehydrohalogenation of vicinal dibromo hydrocarbons (Tetrahedron, 1981, 37, 1653). None of the prior art methods provides a process for preparing alkynes that uses an inexpensive base such as potassium or sodium hydroxide in the solid state in the presence of polyethylene glycols to produce alkynes. None of the prior art methods provides a process for preparing alkynes that utilizes solid sodium hydroxide in the presence of a phase transfer catalyst for dehydrohalogenation to yield an alkyne product that is easily separated from the reaction mixture.
SUMMARY OF THE INVENTION
The present invention provides an inexpensive and convenient process for the preparation of a functional alkyne having an internal triple bond which employs a solid alkali metal hydroxide as the base used for dehydrohalogenation and provides for the easy isolation of the reaction product from the reaction mixture. The process comprises (1) substantially completely brominating a functional internal olefin to form a dibromo compound; (2) contacting said dibromo compound with a liquid phase transfer catalyst and solid alkali metal hydroxide for a time period sufficient to form a reaction mixture comprising a liquid phase containing said alkyne and said phase transfer catalyst and a solid phase comprising an alkali metal bromide and said alkali metal hydroxide; (3) separating said solid phase from said liquid phase; and (4) isolating said alkyne.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a process for the preparation of a functional internal alkyne which employs a solid alkali metal hydroxide in the presence of a phase transfer catalyst and provides for the easy isolation of the reaction product from the reaction mixture. A functional internal alkyne is a compound of the formula 1 ##STR1## wherein at least one of R 1 and R 2 is a linear or branched alkyl group having from 1 to 19 carbons such that the total number of carbon atoms in the molecule is from about 7 to about 22 and having one or more --OH, --NH 2 , --NHR 3 , --NR 3 2 , or --OR 3 groups wherein R 3 is linear or branched alkyl group having from 1 to 19 carbon atoms and one of R 1 or R 2 is a linear or branched alkyl group having from 1 to 19 carbons such that the total number of carbon atoms in the molecule is from about 7 to about 22. Examples of such functional internal alkynes include but are not limited to 9-octadecyn-1-ol, 1-amino-9-octadecyne, 1-methoxy-9-octadecyne, di-(9-octadecynyl) ether.
Any functional internal olefin having at least one --OH, --NH 2 , --NHR 3 --NR 3 2 or --OR 3 functionality that is a liquid at about 140° C. may be used in the process of the present invention. A functional internal olefin is an olefinically unsaturated compound wherein the double bond is in other than a terminal position and having --OH, --NH 2 , --NHR 3 , --NR 3 2 , or --OR functionalities substituted on carbon atoms other than the olefinic carbon atoms. Examples of such functional alkenes having an internal double bond that are liquid at room temperature include alkenes having a total of from 7 carbon atoms to about 22 carbon atoms include but are not limited to oleyl alcohol, oleyl amine, and methyl oleyl ether.
The process of the present invention is particularly suited for the preparation of fatty functional internal alkynes since the olefinically unsaturated compounds from which they are made are relatively inexpensive and the alkyne product forms a readily separable oily layer in the reaction product mixture. Olefinically unsaturated compounds that are particularly preferred as starting materials are fatty alcohols such as undecylenyl alcohol, myristoleyl alcohol, palmitoleyl alcohol, and oleyl alcohol.
The bromination step of the process of the present invention can be carried out by adding approximately a stoichiometric amount of bromine (based on the total amount of unsaturation in the olefinically unsaturated compound) neat or in a solvent at room temperature. The bromination step substantially completely brominates the alkene which means that greater than about 99% of the alkene is brominated as can be noted by the appearance of a yellow-red color of unreacted bromine upon the addition of a slight excess of bromine. It is preferred that the bromination step be carried out in the absence of solvent (neat).
The dehydrohalogenation step can be carried out by contacting the dibromo compound formed in the bromination step with a solid alkali metal hydroxide such as potassium hydroxide or sodium hydroxide in the presence of a phase transfer catalyst. The preferred alkali metal hydroxide is sodium hydroxide. It is preferred that the sodium hydroxide be used as a finely divided powder. The amount of alkali metal hydroxide that can be used is from about 1.5 to about 10 moles per mole of dibromo compound. The preferred amount is from about 2 to about 5 moles per mole of dibromo compound.
The phase transfer catalysts that are suitable for use in the process of the present invention are liquid quaternary ammonium salts and polyethylene glycols. The preferred liquid quaternary ammonium salts are fatty quaternary ammonium compounds such as Aliquat 336 (tricaprylyl methyl ammonium chloride, a product of Henkel Corp).
The preferred phase transfer catalysts are polyethylene glycols. Polyethylene glycols (PEG) which can be used in the process of the present invention are those which have an average molecular weight of from 300 Daltons to 600 Daltons with polyethylene glycol 300 (PEG 300) being particularly preferred. The preferred amount of phase transfer catalyst is from about 0.1 to about 20 weight percent relative to the feed.
The dehydrohalogenation step can be continued until at least 65% of the dibromo compound has been converted to alkyne as determined by analysis of the reaction mixture preferably by gas chromatography. In order to realize a reaction mixture containing at least 65% by weight of alkyne product, the reaction mixture may have to be heated to a temperature of from about 80° C. to about 150° C., preferably 20° C. to about 150° C., for a period of time sufficient to convert the vinyl bromide intermediate to alkyne product as determined by analysis of the reaction mixture preferably by gas chromatography.
An advantage associated with the process of the present invention lies in the fact that since the process is carried out using solid alkali metal hydroxide and in the absence of reaction solvent, the isolation of the alkyne product is very simple.
After the dehydrohalogenation step has been completed, the reaction mixture is allowed to cool to room temperature whereupon a solid and a liquid phase separate from each other. The solid phase is composed of a sodium bromide formed in the reaction and the unreacted solid sodium hydroxide while the liquid phase contains the phase transfer catalyst and the alkyne product. The method of isolating the alkyne product depends upon the solubility of the alkyne product in the phase transfer catalyst. If the alkyne product is not soluble in the phase transfer catalyst, then the alkyne product is isolated by phase separation. If it is soluble in the phase transfer catalyst, the alkyne product is isolated by distillation.
In a preferred embodiment of the process of the present invention, approximately a stoichiometric amount of bromine is added to a neat functional internal olefin until a yellow color persists. After the bromination step, about 5% to about 10% by weight of PEG 300, is added to the reaction mixture along with about 2.5 equivalents (relative to moles of olefin) of powdered sodium hydroxide. The resulting reaction mixture is then heated to about 120° C. to 150° C. and maintained there for about 2 to 5 hours with vigorous stirring. The reaction mixture is then cooled to room temperature and the solid phase comprising sodium bromide formed in the reaction and the unreacted solid sodium hydroxide is then separated from the liquid phase by filtration. The alkyne product is isolated from the liquid phase, which contains the PEG 300 and the alkyne product, either by phase separation or by distillation to give about an 80% yield of product.
The following examples are meant to illustrate but not limit the invention.
EXAMPLE 1
Preparation of 9-Octadecyn-1-ol from Oleyl Alcohol
Oleyl alcohol (9.80 g, 36.5 mmoles, Sigma) was placed in a 25 ml 3-neck roundbottom flask equipped with a thermometer, an overhead mechanical stirrer, and a reflux condenser. The contents of the flask were cooled to 15° C. and bromine (5.83 g, 36.5 mmole) was added slowly with stirring at such a rate as to keep the reaction temperature below 30° C. After addition of the bromine, the reaction was stirred at room temperature for 10 minutes. Polyethylene glycol 300 (1.0 g, Fluka) was added followed by powdered sodium hydroxide (3.65 g, 91.3 mmoles). A large exotherm was noted which brought the reaction temperature to 150° C. The reaction was stirred vigorously with heating to maintain a temperature of 125° C. for 2.5 hours. The reaction was cooled and filtered to remove the solid sodium bromide. The filtered salts were washed with 25 ml of hexanes and the solvent removed. The crude product was kugelrohr distilled (ca. 200° C./ 0.20 torr) to yield 9-octadecyn-l-ol (7.89 g, 81% yield) as a clear colorless liquid which solidified upon standing. 1 H NMR (CDCl 3 ): 3.61 (q, 2H), 2.12 (m, 4H), 1.02-1.87 (m, 25H), 0.88 (t, 3H) 13 C NMR(CDCl 3 ): 79.94, 79.84, 62.33, 32.48, 31.65, 29.19, 29.04, 28.96, 28.66, 28.61, 25.58, 22.45, 18.52, 13.84.
IR (thin film): 3320, 2920, 2840, 1460, 1440, 1050.
MP: 33°-35° C. (uncorrected).
GC: 97%; C, H, Analysis: C: 81.72, H: 12.99
EXAMPLE 2
Preparation of 6-Octadecyn-1-ol from Petroselinyl Alcohol
Petroselinyl alcohol (0.66 g, 2.46 mmoles, Sigma) was placed in a 10 ml 3-neck roundbottom flask equipped with a reflux condenser. Bromine (0.40 g, 2.5 mmole) was added slowly with magnetic stirring. After addition of the bromine, polyethylene glycol 300 (60 mg, Fluka) was added followed by powdered sodium hydroxide (0.250 g, 6.25 mmoles). A large exotherm was noted. The reaction was stirred vigorously with heating to maintain a temperature of 125° C. for 2.5 hours. The reaction was cooled and filtered to remove the solid sodium bromide. The filtered salts were washed with 25 ml of hexanes and the solvent removed. The crude product was kugelrohr distilled (ca. 200° C./ 0.20 torr) to yield 6-octadecyn-1-ol (0.49 g, 75% yield) as a clear colorless liquid which solidified upon standing.
1 H NMR (CDCl 3 ) 3.60 (m, 2H), 2.12 (m, 4H), 1.054-1.86 (m, 25 H), 0.88 (t, 3H).
13 C NMR(CDCl 3 ): 80.38, 79. 77, 62.66, 32.18, 31.84, 29.56, 29.49, 29.28, 29.09, 28.83, 24.91, 22.61, 19.65, 14.02.
IR (thin film): 3310, 2920, 2840, 1460, 1050.
GC: 95% weight percent
EXAMPLE 3
Preparation of 11-Hexadecyn-1-ol from cis-11-Hexadecen-1-ol
Cis-11-Hexadecen-1-ol (4.94 g, 20.4 mmoles, Sigma) was placed in a 25 ml 3-neck roundbottom flask equipped with a thermometer, an overhead mechanical stirrer, and a reflux condenser. The contents of the flask were cooled to 15° C. and bromine (3.28 g, 20.4 mmole) was added slowly with stirring at such a rate as to keep the reaction temperature below 30° C. After addition of the bromine, the reaction was stirred at room temperature for 10 minutes. Polyethylene glycol 300 (0.5 g, Fluka) was added followed by powdered sodium hydroxide (2.05 g, 51.25 mmoles). A large exotherm was noted which brought the reaction temperature to 150° C. The reaction was stirred vigorously with heating to maintain a temperature of 125° C. for 2.5 hours. The reaction was cooled and filtered to remove the solid sodium bromide. The filtered salts were washed with 25 ml of hexanes and the solvent removed in vacuo. The crude product was kugelrohr distilled (ca. 160° C./ 0.20 torr) to yield 11-hexadecyn-1-ol (3.88 g, 80% yield) as a clear colorless liquid.
1 H NMR (CDCl 3 ): 3.67 (m) 2.45 (m), 1.03-1.68 (m)
13 C NMR(CDCl 3 ): 79.91, 79.88, 62.38, 32.50, 31.06, 29.40, 29.28, 28.96, 28.64, 25.61, 21.70, 18. 52, 18.21, 13.38.
IR (thin film): 3300, 2910, 2820, 1460, 1150
GC: 89% weight percent
EXAMPLE 4
Preparation of 9-Octadecyn-1-ol from Technical Oleyl Alcohol
Technical oleyl alcohol (40.0 g, 150 mmoles, Ocenol 90/95, Henkel KGaA) was placed in a 250 ml 3-neck Morton flask equipped with a thermometer, an overhead mechanical stirrer, and a reflux condenser. The contents of the flask were cooled to 15° C. and bromine (24.0 g, 150 mmole) was added slowly with stirring at such a rate as to keep the reaction temperature below 30° C. After addition of the bromine, the reaction was stirred at room temperature for 10 minutes. Polyethylene glycol 300 (4.0 g, Fluka) was added followed by powdered sodium hydroxide (15.0 g, 375 mmoles). A large exotherm was noted which brought the reaction temperature to 150° C. The reaction was stirred vigorously with heating to maintain a temperature of 125° C. for 2.5 hours. The reaction was cooled and filtered to remove the solid sodium bromide. The filtered salts were washed with 100 ml of hexanes and the solvent removed. The crude product was kugelrohr distilled (ca. 200° C./ 0.20 torr) to yield a clear colorless liquid (30.7 g) which was determined by gas chromatography to be 51% by weight 9-octadecyn-1-ol.
EXAMPLE 5
Preparation of 9-Octadecyn-1-ol from Technical Oleyl Alcohol Using Potassium Hydroxide
Technical oleyl alcohol (40.0 g, 150 mmoles, Ocenol 90/95, Henkel KGaA) was placed in a 250 ml 3-neck Morton flask equipped with a thermometer, an overhead mechanical stirrer, and a reflux condenser. The contents of the flask were cooled to 15° C. and bromine (24.0 g, 150 mmole) was added slowly with stirring at such a rate as to keep the reaction temperature below 30° C. After addition of the bromine, the reaction was stirred at room temperature for 10 minutes. Polyethylene glycol 300 (4.0 g, Fluka) was added followed by powdered potassium hydroxide (24.7 g of 85%, 375 mmoles). A large exotherm was noted which brought the reaction temperature to 135° C. The reaction was stirred vigorously with heating to maintain a temperature of 125° C. for 2.5 hours. The reaction was cooled and filtered to remove the solid potassium bromide. The filtered salts were washed with 100 ml of hexanes and the solvent removed in vacuo. The crude product was kugelrohr distilled (ca. 200° C. 0.20 torr) to yield a clear colorless liquid (28.4 g) which was determined by gas chromatography to be 58% by weight 9-octadecyn-1-ol.
EXAMPLE 6
Gas Chromatographic Conditions
Samples were silylated with trimethylsilylchloride for 45 minutes at 70° C. Pentadecanol was used as an internal standard. Column 23 meter× 0.32 mm I.D. capillary fused silica, DB-5 stationary phase. Injection temperature-290° C.; column temperature program of 3 min at 100° C., rising at 12° C./min to 320° C., and holding for 6 min. ECN (effective carbon number) response factors were used for 11-hexadecyn-1-ol and 6- and 16-octadecyn-1-ol. | Functional internal alkynes are conveniently and economically prepared by dehydrohalogenating a dibromide with an alkali metal hydroxide in the presence of a phase transfer catalyst. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for lifting, moving and positioning a workpiece. In particular, it relates to a device and method for lifting a circumferential heater used in the manufacture of silicon ingots by the Czochralski method.
2. Description of the Prior Art
Traditionally, devices used to lift circumferential heaters used in the manufacture of silicon ingots are lowered around the outside edge of the heater. Slider bars are then inserted under the heater, and secured to the lifter. In some instances, a cage is then placed around the heater. Prior devices required an operator to manually place support plates under the heater, attach a cage to the supports, and then attach this apparatus to a lifting device. The heater could then be lifted from the bottom chamber of a Czochralski-type crystal puller machine for machine cleaning or heater replacement. These same devices are also used to place a new heater in the puller machine.
The above device, and similar devices, are appropriate for silicon manufacturing operations. However, they have a number of parts that must be assembled prior to and during the lifting, thereby consuming operator and machine time. This assembly and disassembly results in metal-to-metal contact among the device's parts, within the assembly, potentially damaging the device. Additionally, heat transfer from the heater the lifter, resulting from contact between the heater and the lifter, can cause the lifter to warp, leading to the added cost and time of replacement parts; it also increases the temperature of the lifter, thereby requiring a cooling period before the lifter can be handled.
SUMMARY OF THE INVENTION
In view of the above problems, an object of the present invention is to provide an apparatus and method for lifting and positioning a device, such as a circumferential heater, with reduced operator “hands-on” activity. The present device can be lowered into the center of a circumferential heater, the sling foot pads positioned under the heater, and the heater and lifter combination lifted by a single operator, using a remote control box. The present invention improves on past devices due to an operator's ability to operate it from a distance, reduced metal-to-metal contact, and ease of use.
The present invention also has relatively few parts. This reduces the amount of time an operator must spend setting up and taking down the apparatus, thereby enabling a more efficient process. Additionally, the present invention is, essentially, a one-piece construction after assembly. This helps to control warpage and commensurate part misfits.
Another improvement over the prior art is the present invention's elimination of an exterior cage. As opposed to prior heater-lifting devices, which enclosed the heater within a cage or similar means, the present invention lifts a circumferential heater from within its center void. This interior placement eliminates the need for an exterior cage, thereby reducing operator time, warpage, and heat transfer, as described above.
The present invention also reduces metal-to-metal contact by using polymer-based, ceramic, graphite, carbon composite or equivalent bushings and pads. These pads protect both the lifter and the heater from damage, and keep the lifter cooler than the previous lifter devices. The pads have the additional benefit of not contributing metal contamination to the Czochralski process.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described by reference to the examples and the drawings, in which:
FIG. 1 is a side view of a preferred embodiment of the present invention, with slings extended and support rod in the up position.
FIG. 2 is a top view of a preferred embodiment of the present invention.
FIG. 3 is a side view of the support rod.
FIG. 4 is a top view of the top support.
FIG. 5 is a top view of the bottom support.
FIG. 6 is a front side view of an outer sling.
FIG. 7 is a front side view of a middle sling.
FIG. 8 is a side view of a representative sling.
DETAILED DESCRIPTION OF THE INVENTION
As delineated in the drawings, and shown in FIG. 1, the present invention comprises a support rod 10 , a top support 20 , a bottom support 30 , and a plurality of slings 40 .
As shown in FIG. 3, a support rod 10 comprises a support rod shaft 12 , a bottom pad 14 removably attached to a distal end of the shaft 12 , a top pad 16 removably attached to the end of the shaft 12 opposite the bottom pad 14 , and a hoist mechanism 18 attached to the surface of the top pad 16 opposite the shaft 12 .
The top support 20 , as shown in FIG. 4, comprises a hoist mechanism 22 attached to the top surface of the top support 20 , a center void 24 running vertically through the center of the top support 20 , and a plurality of removably attached pivot shafts 26 . In a preferred embodiment, the pivot shafts 26 as shown in FIG. 4 are seated in three-sided notches 28 spaced about the outer edge of the top support 20 . The shafts 26 and notches 28 are distributed reasonably equally about the circumference of the top support 20 , and are sized such that a sling 40 fits into a notch 28 . The notch 28 is wide and deep enough so that the sling 40 can swing freely, but narrow enough so that the sling 40 has limited horizontal play within the notch 28 .
The bottom support 30 , shown in FIG. 5, comprises a center void 32 and a plurality of circumferential slots 34 . The slots 34 are arranged substantially similar to the upper support pivot shafts 26 and notches 28 , but are located a greater distance from the bottom support center void 32 than the pivot shafts 26 are from the top support center void 24 .
A representative sling 40 is shown in FIG. 1 . The sling 40 has a rigid body 42 and foot plate 44 as shown in FIG. 8 . Fixed stoppers 46 are located approximately medially on the rigid body 42 of the slings. A cylindrical void 48 at one end of the rigid body 42 attaches to the top support pivot shafts 26 . The foot plate 44 attaches to the other end of the rigid body 42 . In a preferred embodiment of the invention, the slings comprise middle slings 50 (FIG. 7) and outer slings 52 (FIG. 6 ). In such an embodiment, the middle slings 50 are wider than the outer slings 52 . The differing widths are necessary in this embodiment because of the configuration of the workpiece supports. If required, all of the slings could be of varying or equal widths, depending on the workpiece.
As shown in FIGS. 1, 4 , and 5 , the invention is configured such that the support rod shaft 12 runs through both the top support center void 24 and the bottom support center void 32 . The bottom pad 14 is disposed below the bottom support 30 such that when the invention is in a substantially upright position, the bottom support 30 is supported by the bottom pad 14 . The support rod top pad 16 is disposed above the top support 20 such that the top support 20 is at all times between the top pad 16 and the bottom support 30 .
In a preferred embodiment of the invention, though it would not be so limited, a washer (not shown), composed of a polymer-based, heat-resistant material such as Teflon®, covers the inside surface of the top and bottom support center voids 24 and 32 so as to minimize metal-to-metal contact between the support rod 10 and the top support 20 and bottom support 30 .
The slings 40 are swingably connected by pivot shafts 26 to the top support 20 such that the cylindrical void 48 of the slings 40 fits into the notches 28 of the top support 20 . In a particular embodiment of the invention, though it would not be so limited, a bushing (not shown), composed of a polymer-based, heat-resistant material such as Teflon®, or another non-metallic, heat resistant material such as a ceramic, is utilized in combination with the pivot shaft 26 such that minimal metal-to-metal contact occurs between the sling 40 and the top plate 20 .
In a preferred embodiment, a polymer-based, heat-resistant material such as Teflon® can be used to form pads 45 . The pads 45 are fixably attached to the upper surface of the foot plate 44 of the sling 40 . In addition to a polymer-based material, other heat-resistant, non-metallic materials, such as ceramic, could be utilized in the bushings, washers, pads, and other heat protective elements included in the invention.
The slings 40 pass through the slots 34 of the bottom support 30 . The bottom support 30 has a range of motion slidably along the slings with upper and lower limits at the medially positioned stoppers 46 and the sling foot plate 44 . In a preferred embodiment of the invention, though it would not be so limited, the interior of the slots 34 are lined with a polymer-based, heat-resistant material such as Teflon® or equivalent. The heat resistant material would extend outwardly along the upper and lower surface of the bottom support 30 such that when in the open position there is minimal metal-to-metal contact between the bottom support 30 and the sling stoppers 46 .
In a preferred method, the apparatus would be used to raise, lower, and position a circumferential heater into the lower portion of a Czochralski-type puller machine utilized in the semiconductor industry. One skilled in the art, however, could utilize both the apparatus and the method in any situation where the workpiece has an interior void suitable for insertion of a circumferential lifter as disclosed herein.
In a preferred method, beginning with the step where the apparatus is outside the heater, and the heater is to be lifted out of the puller machine for cleaning, replacement, or other suitable reason, an operator attaches a support line or similar device to the top support hoist mechanism 22 . The support line could be secured to the hoist mechanism by means of a hook, or quick release securing device or equivalent. The operator then raises the apparatus, and lowers the apparatus into the pulling machine such that the apparatus is positioned in the interior of the circumferential heater. The operator then repositions the support line from the top support hoist mechanism 22 to the support rod hoist mechanism 18 . The operator then places tension on the support line, thereby causing the support rod 10 to rise. The rising support rod causes the slings 40 to extend outward and under the circumferential heater. The heater-lifter combination is then ready for lifting or repositioning. The operator can then raise the heater-lifter combination out of the puller machine, and position it on the shop floor or other desired location. After the heater-lifter combination is placed at the desired position, the support line is slacked, causing the support rod 10 to lower. The lowering support rod causes the slings 40 to retract, thereby disengaging the heater from the lifter. The lifter can then be extracted from the interior of the heater by repositioning the support line from the support rod hoist mechanism 18 to the top support hoist mechanism 22 , and lifting the lifter. | The heater sling according to this invention is capable of lifting, moving and positioning a workpiece. In particular, it relates to a device and method for lifting a circumferential heater used in the manufacture of silicon ingots by the Czochralski method. The invention operates by mechanically extending a plurality of slings under a workpiece, lifting the workpiece, and placing it in a desired location. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to insect repellents and more particularly to certain novel carboxamides containing an alicyclic moiety and their use as insect repellents.
2. Description of the Prior Art
There is a continuing need for insect repellents or formulations thereof that are significantly more effective or longer lasting than those now in use. All of the repellents now in use for application to the skin have disadvantages, that is, they are not effective for long enough periods of time and are subject to loss by abrasion, evaporation, absorption, and immersion in water. Moreover, all cause a stinging sensation when they contact the eyelids and lips, and are effective only when they are present on the skin or clothing in relatively large quantities. Mosquitoes, sand flies, black flies, stable flies, tsetse flies, gnats, and tabanids are among the many species of biting fly that cause annoyance and distress throughout the world. Many species of biting insects spread human and animal diseases. There are many areas throughout the world in both developed and developing nations where the use of protective clothing and repellents is the only means available to individuals for personal protection. Deet (N,N-diethyl-m-toluamide) has proved to be the most outstanding all-purpose individual repellent yet developed (Proceedings of a Symposium, University of Alberta, Edmonton, Canada, May 16-18, 1972, Defense Research Board, Ottawa, Canada, 1973. DR-217: 109-113). Deet was reported as a promising repellent in 1954 (Journal of Organic Chemistry, 19, 493, 1954). Since that time, no repellent has been reported as being superior to deet as an all-purpose repellent despite a continuing search for such a chemical.
SUMMARY OF THE INVENTION
An object of this invention is to provide a class of compounds that are useful as insect repellents.
The above object is accomplished by a number of novel carboxamides having from about 11 to about 18 carbon atoms and containing an alicyclic moiety. Many of these compounds are more effective than presently available repellents and many are effective against a wide variety of insects.
DESCRIPTION OF THE INVENTION
The compounds of this invention are represented by the formula below ##STR2## wherein R 3 is one of the groups A, B, or C ##STR3## R is hydrogen or lower alkyl, n is zero or the positive integer one, two, or three, each of R 1 and R 2 is alkyl, or taken together represent an alkylene, an alkenylene, an alkyl substituted alkylene, an alkylene ether, and alkyl substituted alkylene ether, or an alkyl substituted alkylene amine ring structure.
The compounds of this invention are useful as insect repellents and are particularly effective against many Dipteran.
The novel compounds of this invention are especially effective in repelling a wide variety of insects such as ticks, chiggers, cockroaches, and biting diptera such as mosquitoes, stable flies, deer flies, black flies, and sand flies. Certain novel amides reported in this invention are about equally as effective as deet against mosquitoes and are significantly more repellent than deet against other biting flies when tested on skin. The skin test is the obvious critical test when one considers personal protection; however, clothing repellents are also very important especially in areas of heavy mosquito infestations (The Journal of the American Medical Association, 196, 253, 1966). Certain amides of this invention provide exceptional protection against mosquitoes when applied to cloth.
The amides were synthesized as follows: the appropriate acid chloride was slowly added with stirring to an anhydrous ether solution of the amine cooled in an ice bath (either the amine itself or pyridine was used as a hydrochloric acid scavenger). The reaction mixture was allowed to warm to room temperature and then allowed to stand for several hours, usually overnight. The amides were isolated by routine extraction procedures and purified by distillation under high vacuum. Purity was checked by gas chromatographic analysis.
A typical procedure is illustrated by the following description of the synthesis of 1-(3-cyclohexenecarbonyl) piperidine, compound 20 in Table 1: 3-cyclohexenecarbonyl chloride, 28.9 grams (0.2 mole), was added dropwise to an ice cold solution (0°-10° C.) of piperidine, 34 grams (0.4 mole) in 250 ml of anhydrous ether. The solution was stirred vigorously during the addition. The reaction mixture was allowed to warm to room temperature and to stand overnight. Water was added to dissolve the precipitated piperidine hydrochloride salt. The organic layer was then washed sequentially with 5% hydrochloric acid and sodium bicarbonate solutions and finally with a saturated salt solution until the wash was neutral to litmus paper and dried over anhydrous magnesium sulfate. After filtering, the solvent was removed under reduced pressure (water pump). The crude amide was distilled under high vacuum to give 31.4 grams of product-b.p. 114°-15° C./0.2 mm Hg), n D 25 1.5159.
The physical constants of the compounds are presented in Table 1.
The repellent activity of the amides of the present invention was demonstrated by practical laboratory and field tests against mosquitoes and a variety of other biting diptera. The effectiveness of the repellents was determined by directly comparing their repellency with that of deet in tests on skin and with dimethyl phthalate in tests on cloth.
In the following description of the testing procedures the first confirmed bite is defined as a bite followed by another within thirty minutes.
For the purposes of this invention, the compounds were tested as solutes in alcohol, acetone, or other volatile solvent. However, other compatible liquid or solid carriers may also be used.
TESTING PROCEDURES
STABLE FLIES.
The repellents were applied as 1-ml aliquots of a 25% ethanol solution and spread evenly over the forearm of a subject from wrist to elbow. Since the ethanol solution was formulated on a weight-volume basis, 250 mg of repellent was applied to the forearm in each test. The most promising compounds (those equal to or better than the deet standard at the 25% dosage) were then tested as 12.5% and 6.25% ethanol solutions.
The evaluations were carried out in an outdoor cage (103 cm square and 133 cm high) constructed of aluminum and having a solid top and bottom and screen wire on four sides. Four of the sides had port openings covered with 30.5-cm (12-in.) tubular cloth stockinettes. The centers of the ports were 30 cm from the bottom of the cage, which rested on a table 80 cm high. One arm each of up to four treated subjects at a time could be inserted through the ports into the cage.
Approximately 12,000 S. calcitrans pupae were placed in cups and allowed to emerge in the test cage over an 8-day period. The tests were started the 4th day, when approximately 8000 flies had emerged. The remaining 4000 that emerged over the next 4 days maintained a relatively stable population in respect to numbers and avidity. Citrated beef blood on a cotton pad was offered for 45 minutes each day after the repellent tests were completed. This short-term feeding period provided a small but adequate food intake, and avidity was not reduced as a result of complete engorgement. Results obtained when an untreated forearm was inserted into the test cage before and during the tests each day gave a measure of the avidity of the flies, though it was impossible to count the attacks on the untreated arm.
The effectiveness of each chemical was determined by the protection time; that is, the time between treatment and the first confirmed bite. Therefore, 30 minutes after the application of the test chemical and every 30 minutes thereafter, the treated arms were inserted into the test cage for 3 minutes unless bites occurred sooner.
Since test subjects differ in attractiveness and insects differ in avidity, the best measure of the effectiveness of a repellent is its ratio of protection time vs. that of a standard repellent used in similar conditions. Deet was the standard in all of the tests reported here. It was paired with each of the other candidate repellents in 10 different test series.
The experimental design used was a round-robin series in which each repellent was paired concurrently against another repellent on the arms of a subject. An adjusted average protection time that allowed for individual variation between test subjects and test conditions was then computed (Soap and Chemical Specialties, 33, 115-17 and 129-133, 1957).
BLACK FLIES.
The principal test site was in the vicinity of Kidney Pond, Baxter State Park, Maine. Meadows bordered by fast moving mountain streams and an abundance of wildlife provided optimum breeding conditions in this area. Several species of blackflies were represented in the population attacking four test subjects. Of these, the two most abundant were identified as Simulium venustum Say and Prosimulium mixtum Syme and Davis. Repellents were applied as 1-ml aliquots of a 12.5 or 25% ethanol solution and spread evenly over the forearm of a subject from wrist to elbow. The ethanol solution was formulated on a weight-volume basis, so either 125 or 250 mg of repellent was applied in each test.
Treated arms were continuously exposed to the natural populations of flies. Subjects intermittently moved about with arms raised or on hips, squatted, or sat down for brief periods of 5 to 10 minutes. These positions, coupled with slow walking and standing every few minutes, appeared to be attractive to black flies (Simulids and Prosimulids) and were used as standard procedure in all tests. Heat-nets and gloves were worn by the test subjects to prevent attack on exposed untreated parts of the body.
Two series of round-robin tests were conducted in the spring of 1977 using 12.5 or 25% solutions of repellent in ethanol; one series was conducted during June 1978 using a 25% solution of repellent in ethanol. The effectiveness of each chemical was determined by the protection time, i.e., the time between treatment and the first confirmed bite. Since test subjects differ in attractiveness and insects differ in avidity, the best measure of the effectiveness of a repellent is the ratio of its protection time to that of a standard repellent under similar conditions. Deet was the standard repellent in these tests.
In the round-robin test each repellent was paired with each other repellent on the arms of a subject (four or five replicates). An adjusted average protection time that allowed for individual variations between test subjects and test conditions was then computed. Black fly landing rates ranged from 14 to 40/minute during the test period.
DEER FLIES.
The compounds and the standard repellent, deet, were tested on the forearms of human subjects against natural populations of the deer fly, Chrysops atlanticus. The materials were formulated as 25% ethanol solutions and applied at the rate of 1 ml per forearm. The field tests were conducted along logging roads adjacent to the marshes of the Ogeechee River at Richmond Hill, Ga., where C. atlanticus populations occur in great numbers annually. Since the flies are attracted to motion, the test subjects continually walked while exposing their treated arms to the flies. The tests were terminated when a confirmed bite was received. The chemicals were evaluated in round-robin tests with five compounds and a deet standard in each series. During the 3-week test period the landing rate averaged 33 flies/man and ranged from 13 to 54/man.
SAND FLIES.
Two test sites were used, one at YankeeTown, Fla. on the Gulf coast and one at Parris Island, South Carolina. The repellents were applied as 25% solutions in ethanol on the forearms (wrist to elbow) of test subjects. Because of the limited period of insect activity (early morning or late afternoon to dusk) the subjects were pretreated 2 hours prior to the test period to effect aging of the repellents. The repellents were evaluated against the standard repellent, deet, in paired tests (3 replications). A test repellent was applied to one arm of a subject and deet to the other. Effectiveness was determined by the number of bites received during the test period. A control (no repellent treatment) was included in each test to ascertain the level of insect pressure.
MOSQUITOES.
Tests on skin.
For laboratory tests, 1 ml of a 25% ethanol solution of the repellent was spread evenly over the forearm of the subject. The treated forearms were exposed to about 1500 female laboratory reared Aedes aegypti or Anopheles quadrimaculatus mosquitoes in cages. Effectiveness was based on complete protection, that is, the time between treatment and the first confirmed bite. The effectiveness of the compounds was compared to that of the standard repellent, deet. The chemicals were tested in a round-robin series in a balanced incomplete block design in which each repellent in the series was paired against each other repellent in the series on opposite arms of a given number of subjects.
The field tests were conducted at sites adjacent to Mosquito Lagoon near New Smyrna Beach, Fla. The repellents were applied in the same manner as for the laboratory tests. The treated arms were exposed continuously to the natural population of mosquitoes until the first confirmed bite was received. Protective clothing and head nets were worn by the test subjects to protect against attack on exposed untreated parts of the body. The experimental design used was a balanced incomplete block as in the laboratory tests.
Tests on cloth.
Test materials were applied at the rate of 3.3 g of compound per 0.1 m 2 cloth to a measured portion (0.03 m 2 ) of a cotton stocking as 10% solutions in acetone or other volatile solvent. After 2 hours, the treated stocking was placed over an untreated nylon stocking on the arm of a human subject and exposed for 1 minute in a cage containing about 1500 five- to eight-day old A. aegypti or A. quadrimaculatus. The test exposure was repeated at 24 hours and then at weekly intervals until five bites were received in 1 minute. Days to the first bite and to five bites were recorded. Between tests, the treated stockings were placed on a rack at room temperature, and evaporation was allowed to continue. A standard repellent, dimethyl phthalate, was tested concurrently and was effective for 11 to 21 days against both mosquito species.
The merits of the present invention are illustrated in the results shown in the tables.
The data in Table 2 show compounds 2, 7, 20, 33, 34, 47, and 49 were more active against the stable fly than the deet standard at all concentrations tested. Compounds 20 and 34 were significantly more effective than deet at all three dosages (0.05% level of confidence). Compounds 21 and 35 were more active than deet at two concentrations and equal to it at the lowest concentration tested. The repellent effect of certain of these chemicals was as much as 4.5× that of deet and provided protection up to 9 hours; the protection time of deet ranged from 2 to 3 hours. Data for compounds 4, 6, 17, 18, 19, 31, and 45 are shown to illustrate the unpredictability of repellent activity of closely related chemicals.
The data in Table 3 show all eight compounds and deet are very good black fly repellents. Compound 21 is significantly more effective than deet at the 25% dosage providing about 10.5 hours protection. There is no significant difference between the remaining compounds and deet at the 25% dosage. Although not significantly more effective than deet, the adjusted mean for compound 20 was 0.5 and 1.5 hours greater than that of deet at the two test dosages. Compounds 7 and 35 provided about 7 hours protection; compounds 20 and 47 provided over 8 hours protection; compounds 6 and 33 provided about 9 hours protection.
The data in Table 4 show 10 compounds that exceeded deet in repellency against deer flies. Compound 20 was significantly more effective than deet with an adjusted mean protection time of 6.3 hours.
The data in Table 5 show compounds 2, 7, 20, and 35 greatly superior to deet in tests conducted in Florida against the sand fly Culicoides mississippiensis. Compounds 2 and 20 were also superior to deet in the Parris Island tests against Culicoides hollensis. Deet is considered a good repellent for sand flies (Meditsinskaya Parazitologiya i Parazitarnye Bolezni, 35 (5), 549, 1963). A biting rate of about 5/hour would make the presence of sand flies tolerable to most people (Journal of Economic Entomology, 64 (1), 264, 1971). The data show certain compounds of this invention equalling or exceeding this criteria in one test and equalling or closely approaching it in the second test. The number of bites experienced by the check, clearly shows very high insect pressure during these tests, emphasizing the effectiveness of the repellents.
The data in Table 6 show the relative repellency of compounds of this invention against mosquitoes when applied to skin in laboratory and field tests. Deet is an excellent mosquito repellent (The Journal of the American Medical Association, 196, 253, 1966). Repellents 33 and 34 were about equally as effective against Aedes aegypti as deet; repellents 19, 20, 21, and 34 were about equally as effective against Anopheles quadrimaculatus as deet. In field tests, repellents 2 and 20 were 1.5 and 1.4 times as effective as deet against Aedes taeniorhynchus and 4, 6, 7, 21, 33, and 47 were about equally as effective as deet. Because deet is such an effective mosquito repellent, chemicals having 0.5 ratios to deet are considered good mosquito repellents.
The data in Table 7 show 91 of the repellents were more effective than the standard against one species of mosquito and 9 other compounds were about equally as effective as the standard. Repellents 91, 100, 101, and 115 provided outstanding protection of over 200 days and 29 other repellents provided exceptional protection of over 100 days against one species or the other. All chemicals providing 11 or more days protection are considered promising repellents.
The foregoing examples of repellent action of these novel amides against specific insect pests is meant to be illustrative rather than limiting. For example, the compounds of the present invention can be mixed with inert ingredients or with other known insect repellents. The compounds may also be formulated or embodied into repellent compositions in the form of creams, lotions, emulsions, suspensions, solutions, dusts, and aerosol or other type of sprays.
Although insect repellents are usually applied to the skin, the compounds of this invention and formulations containing them are also useful when applied to clothing, netting, packaging, shipping containers, animals, and growing plants.
TABLE 1__________________________________________________________________________Physical constants of compounds synthesized in accordance with theprocedures of this invention No. ##STR4## or m.p. (°C.)B.p. (°C./mmHg)Physical constants n.sub.D.sup.25 No. ##STR5## or m.p. (°C.)B.p. (°C./mmHg)Physical constants n.sub.D.sup.25__________________________________________________________________________ ##STR6##1 N,N-Dimethylamino 69-70/0.45 1.4794 9 4-Methyl-1-piperidyl 113-14/0.8 1.49702 N,N-Dipropylamino 93-5/0.45 1.4685 10 2-Ethyl-1-piperidyl 131/1.5 1.49703 N,N-Dibutylamino 133/1.5 1.4675 11 2,6-Dimethyl-1-piperidyl 109-11/0.5 1.49504 1-Pyrrolidyl 67-8 12 1,2,3,6-Tetrahydro-1- 107-9/0.5 1.5175 pyridinyl5 1-Piperidyl 108/0.45 1.5030 13 4-Methyl-1-piperazinyl 100-2/0.1 1.50416 1-Hexahydro-1H-azepinyl 120/0.25 1.5038 14 4-Morpholinyl 57-87 2-Methyl-1-piperidyl 110-13/0.7 1.5001 15 2.6-Dimethyl-4-morpholinyl 116-17/0.3 1.49198 3-Methyl-1-piperidyl 114-16/0.45 1.4974 ##STR7##16 N,N-Dimethylamino 75-6/0.4 1.4960 24 4-Methyl-1-piperidyl 110-12/0.15 1.508717 N,N-Dipropylamino 88/0.15 1.4804 25 2-Ethyl-1-piperidyl 114-15/0.1 1.506818 N,N-Dibutylamino 103/0.1 1.4775 26 2.6-Dimethyl-1-piperidyl 112-13/0.1 1.505519 1-Pyrrolidyl 44-5 27 1,2,3,6-Tetrahydro-1- 114-16/0.45 1.5315 pyridinyl20 1-Piperidyl 114-15/0.2 1.5159 28 4-Methyl-1-piperazinyl 112-14/0.1 1.518121 1-Hexahydro-1H-azepinyl 105-6/0.15 1.5151 29 4-Morpholinyl 114-16/0.25 1.519422 2-Methyl-1-piperidyl 110-12/0.1 1.5106 30 2,6-Dimethyl-4-morpholinyl 115-16/0.4 1.504323 3-Methyl-1-piperidyl 108-10/0.1 1.5087 ##STR8##31 N,N-Dipropylamino 100/0.7 1.4682 38 4-Methyl-1-piperidyl 108/0.8 1.490832 N,N-Dibutylamino 126/0.9 1.4669 39 2-Ethyl-1-piperidyl 175-8/18 1.493033 1-Pyrrolidyl 95/0.25 1.4941 40 2.6-Dimethyl-1-piperidyl 108-10/0.5 1.490534 1-Piperidyl 104-6/0.5 1.4970 41 1,2,3,6-Tetrahydro-1- 118-20/1.3 1.5100 pyridinyl35 1-Hexahydro-1H-azepinyl 115-18/0.9 1.5000 42 4-Methyl-1-piperazinyl 120-2/1.0 1.499036 2-Methyl-1-piperidyl 141-3/0.25 1.4930 43 4-Morpholinyl 108-9/0.4 1.497537 3-Methyl-1-piperidyl 168-70/18 1.4909 44 2,6-Dimethyl-4-morpholinyl 75-7 ##STR9##45 N,N-Dipropylamino 108/2.0 1.4794 52 4-Methyl-1-piperidyl 122-4/1.0 1.502046 N,N-Dibutylamino 120/0.45 1.4765 53 2-Ethyl-1-piperidyl 116-18/0.5 1.503647 1-Pyrrolidyl 133-6/0.2 1.5082 54 2.6-Dimethyl-1-piperidyl 115-17/0.5 1.501748 1-Piperidyl 109/0.5 1.5090 55 1,2,3,6-Tetrahydro-1- 113-15/0.7 1.5234 pyridinyl49 1-Hexahydro-1H-azepinyl 135/0.9 1.5116 56 4-Methyl-1-piperazinyl 105-7/0.3 1.510650 2-Methyl-1-piperidyl 120-2/1.1 1.5049 57 4-Morpholinyl 104-5/0.2 1.511551 3-Methyl-1-piperidyl 120-2/1.3 1.5035 58 2,6-Dimethyl-4-morpholinyl 122-5/0.4 1.4990 ##STR10##59 N,N-Dipropylamino 93-5/0.2 1.4900 66 4-Methyl-1-piperidyl 98-100/0.1 1.516360 N,N-Dibutylamino 100-2/0.1 1.4862 67 2-Ethyl-1-piperidyl 108-9/0.15 1.516861 1-Pyrrolidyl 105-8/0.15 1.5262 68 2,6-Dimethyl-1-piperidyl 100-1/0.15 1.516662 1-Piperidyl 111-13/0.2 1.5244 69 1,2,3,6-Tetrahydro-1- 110/0.1 1.5401 pyridinyl63 1-Hexahydro-1H-azepinyl 121-2/0.4 1.5262 70 4-Methyl-1-piperazinyl 103-4/0.1 1.525364 2-Methyl-1-piperidyl 108-9/0.2 1.5197 71 4-Morpholinyl 99-100/0.1 1.525865 3-Methyl-1-piperidyl 110-12/0.3 1.5169 72 2,6-Dimethyl-1-morpholinyl 100-2/0.1 1.5113 ##STR11##73 N,N-Dimethylamino 87-8/0.45 1.4780 81 4-Methyl-1-piperidyl 121/0.5 1.493574 N,N-Dipropylamino 108-9/0.45 1.4708 82 2-Ethyl-1-piperidyl 122-4/0.2 1.494375 N,N-Dibutylamino 139/0.75 1.4698 83 2,6-Dimethyl-1-piperidyl 121-3/0.3 1.494276 1-Pyrrolidyl 110-12/0.25 1.4977 84 1,2,3,6-Tetrahydro-1- 122-4/0.15 1.5114 pyridinyl77 1-Piperidyl 109-11/0.2 1.5000 85 4-Methyl-1-piperazinyl 109/0.15 1.501678 1-Hexahydro-1H-azepinyl 114-16/0.2 1.5019 86 4-Morpholinyl 68-7079 2-Methyl-1-piperidyl 105-7/0.2 1.4945 87 2,6-Dimethyl-4-morpholinyl 125-7/0.5 1.489280 3-Methyl-1-piperidyl 118/0.4 1.4942 ##STR12##88 N,N-Dimethylamino 100-2/0.4 1.4782 96 4-Methyl-1-piperidyl 136-7/0.5 1.491989 N,N-Dipropylamino 117-18/0.45 1.4715 97 2-Ethyl-1-piperidyl 126-7/0.1 1.493890 N,N-Dibutylamino 133-5/0.4 1.4701 98 2,6-Dimethyl-1-piperidyl 135/0.35 1.489591 1-Pyrrolidyl 126-7/0.2 1.4928 99 1,2,3,6-Tetrahydro-1- 134-5/0.5 1.5070 pyridinyl92 1-Piperidyl 129-31/0.2 1.4950 100 4-Methyl-1-piperazinyl 139- 40/0.1 1.496693 1-Hexahydro-1H-azepinyl 131-4/0.3 1.4985 101 4-Morpholinyl 122-4/0.1 1.496194 2-Methyl-1-piperidyl 128-30/0.35 1.4933 102 2,6-Dimethyl-4-morpholinyl 123-5/0.1 1.487695 3-Methyl-1-piperidyl 136-8/0.5 1.4912 ##STR13##103 N,N-Dimethylamino 109-10/0.4 1.4764 111 4-Methyl-1-piperidyl 145-7/0.45 1.4875104 N,N-Dipropylamino 128-30/0.4 1.4712 112 2-Ethyl-1-piperidyl 145/0.25 1.4910105 N,N-Dibutylamino 148/0.4 1.4705 113 2,6-Dimethyl-1-piperidyl 151-3/0.5 1.4874106 1-Pyrrolidyl 137-9/0.4 1.4905 114 1,2,3,6-Tetrahydro-1- 145-6/0.45 1.5035 pyridinyl107 1-Piperidyl 139-40/0.5 1.4920 115 4-Methyl-1-piperazinyl 134-5/0.15 1.4975108 1-Hexahydro-1H-azepinyl 153-4/0.5 1.4940 116 4-Morpholinyl 149-51/0.45 1.4932109 2-Methyl-1-piperidyl 142-3/0.45 1.4909 117 2,6-Dimethyl-4-morpholinyl 145-7/0.45 1.4828110 3-Methyl-1-piperidyl 143-5/0.5 1.4882__________________________________________________________________________
TABLE 2______________________________________Repellency of compounds to the stable fly Stomoxyxcalcitrans when applied to the skin at various concentrationsin ethanol and compared to deet as a test standard Protection time (minutes)% Adjusted Ratio to No. ofNo. Conc. Range mean deet.sup.a tests______________________________________2 6.25 30-90 55 1.7 312.5 300-360 315 4.50.sup.b 525.0 210-463 321 2.02.sup.b 54 25.0 30-270 103 0.4 56 25.0 30-268 183 0.71 57 25.0 120-300 246 2.01.sup.b 417 25.0 180-360 225 0.85 518 25.0 30-189 122 0.46 519 25.0 90-420 237 1.0 520 6.25 30-120 103 2.5.sup.b 312.5 60-240 128 2.4.sup.b 425.0 360-390 387 2.39.sup.b 521 6.25 30-60 33 1.0 512.5 270-450 306 1.42 525.0 300-510 457 3.78.sup.b 431 25.0 30-60 36 0.2 533 6.25 60-180 80 1.6 312.5 90-210 150 3.3.sup.b 425.0 240-270 266 1.6 434 6.25 30-120 118 2.4.sup.b 312.5 270-330 320 4.57.sup.b 525.0 390-510 419 2.6.sup.b 435 6.25 30-30 30 1.0 512.5 210-375 326 3.27.sup.b 525.0 390-510 459 2.9.sup.b 436 25.0 30-120 101 1.43 545 25.0 30-180 78 0.44 547 6.25 30-90 63 1.9 312.5 120-270 230 3.29.sup.b 525.0 150-405 264 1.66 549 6.25 30-60 38 1.15 512.5 150-330 306 1.42 525.0 480-510 538 3.02.sup.b 550 25.0 60-150 125 1.41 5______________________________________ .sup.a Data compiled from a number of different tests, accounting for the fluctuation between protection time and ratio to deet among the members o the series. .sup.b Significantly different from deet at the 0.05% level of confidence
TABLE 3______________________________________Repellency of compounds applied to the skin as 12.5 and/or25% ethanol solutions compared with deet againstblackflies in two series of field tests Protection time (min) % Adjusted Ratio to No. ofNo. Conc. Range mean deet tests______________________________________Test I (1977)Deet (Std) 12.5 145-283 161 1.00 5 25.0 287-511 426 1.00 420 12.5 123-314 193 1.20.sup.a 5 25.0 413-565 505 1.19.sup.a 4 7 12.5 26-222 95 0.59 5 25.0 309-515 424 1.00.sup.a 435 12.5 24-126 93 0.58 5 25.0 342-542 412 0.97.sup.a 4 2 12.5 25-112 71 0.44 5 25.0 198-375 314 0.74.sup.a 4Test II (1978)Deet (Std) 25.0 399-623 520 1.00 5 6 25.0 411-628 537 1.03.sup.a 521 25.0 524-725 632 1.21.sup.b 533 25.0 498-603 554 1.07.sup.a 547 25.0 425-649 486 0.94.sup.a 5______________________________________ .sup.a Not significantly different from deet at the 0.05% level of confidence. .sup.b Significantly different from deet at the 0.05% level of confidence
TABLE 4______________________________________Repellency of compounds applied to the skin as25% ethanol solutions and compared with deet againstdeerflies in field tests (Avg. of 5 tests)Protection time (min) Ratio toNo. Range Adjusted mean deet.sup.a______________________________________2 10-178 133 3.004 4-77 23 0.516 10-173 75 1.6917 15-143 62 1.3918 6-36 40 0.8920 363-421 380 5.83.sup.b21 91-203 91 1.131 10-44 45 0.6234 20-408 141 1.835 42-182 119 1.536 5-17 15 0.9445 4-110 18 0.2447 40-160 138 1.8949 37-244 129 1.7650 8-138 27 1.11______________________________________ .sup.a Data compiled from a number of tests, accounting for the fluctuation between the protection time and ratio to deet among the members of the series. .sup.b Significantly different from deet at the 0.05% level of confidence
TABLE 5______________________________________Repellency of compounds applied to the skinas 25% ethanol solutions and compared with deetagainst the sandflies Culicoides mississippiensisand Culicoides hollensis in field testsCompounds Average Averagepaired bites/test bites/hour______________________________________Tests at Yankee Town, Fla. (Avg. 3 tests)Deet 29.0 19.22 3.33 2.4Deet 31.67 21.020 5.0 3.6Deet 106.0 70.835 6.67 4.2Deet 45.0 30.07 10.0 6.6Check 1299 865.8Tests at Parris Island, S. C. (Avg. 3 tests)Deet 28.67 18.620 9.33 6.0Deet 85.0 54.62 16.33 10.8Deet 12.0 7.87 16.67 10.8Check 1566 1277.4______________________________________
TABLE 6______________________________________Repellency of compounds to mosquitoes when appliedto the skin as 25% ethanol solutionsRatio to deetLaboratory test Field test Aedes Anopheles AedesNo. aegypti quadrimaculatus taeniorhynchus______________________________________ 2 0.22 0.28 1.5 4 0.22 0.11 0.77 6 0.14 0.74 0.82 7 0.70 0.11 1.1517 0.24 0.33 0.5218 0.13 0.05 0.0719 0.20 0.73 0.4420 0.68 1.0 1.421 0.64 0.86 0.731 0.24 0.08 0.4533 1.12 0.86 0.6934 0.89 1.0 0.3445 0.23 0.11 0.1247 0.28 0.24 0.9949 0.55 0.09 0.65______________________________________
TABLE 7______________________________________Repellency of compounds to mosquitoes in tests on clothAedes aegypti Anopheles quadrimaculatusDays to Days toNo. 1st bite 5 bites 1st bite 5 bites______________________________________ 2 15 15 8 84 30 38 38 795 30 38 30 306 106 113 22 387 104 104 111 1118 104 104 22 229 52 104 0 2210 104 104 1 2211 104 104 1 3712 15 15 15 1513 7 15 7 11114 0 1 27 2715 15 28 35 3517 15 15 15 1518 0 30 0 119 28 28 70 9420 21 28 28 4821 64 87 70 7022 69 69 83 8323 36 36 36 5124 20 20 83 8325 83 83 83 8326 36 36 36 3627 36 36 63 6328 28 28 63 8329 0 0 35 3530 8 8 22 2231 15 15 1 133 21 28 28 2834 21 28 13 1335 28 28 6 636 23 43 0 037 23 51 0 038 36 36 21 2139 51 71 0 040 1 23 0 041 8 15 8 842 1 1 36 5043 36 77 64 7144 28 28 15 1545 27 27 1 147 27 27 1 148 33 41 1 149 27 47 1 150 23 51 0 2351 36 36 0 2152 36 36 8 3655 15 15 0 157 8 22 36 10558 1 28 22 2259 1 35 49 4961 34 55 28 2862 70 70 70 9163 70 128 0 11164 70 70 0 7665 35 70 0 4966 70 70 0 7767 21 34 47 4768 1 28 20 2069 28 28 20 2070 28 28 47 4771 0 0 47 4772 0 34 20 19074 0 0 28 2876 108 108 21 11977 28 108 28 2878 21 130 1 879 28 102 0 080 28 102 0 081 28 51 8 882 0 28 8 883 101 108 108 10884 8 28 28 2885 0 105 134 17586 0 1 1 1887 0 105 126 12688 21 21 24 2491 169 169 238 23892 29 29 7 18293 21 65 21 4494 7 21 1 195 7 21 1 12697 0 12 0 1298 0 21 126 12699 0 12 0 93100 7 7 21 268101 61 133 238 238102 61 93 133 133103 42 42 24 54106 61 160 160 160107 0 36 36 36108 22 22 36 134110 0 1 36 36111 0 0 52 94112 13 13 36 104113 0 1 134 134114 0 36 134 134115 0 51 310 318+116 77 134 134 134117 22 22 134 134______________________________________ +Compound still in test. | A number of alicyclic carboxamides of the formula ##STR1## wherein n, R 1 , R 2 , and R 3 are defined hereinbelow have been found to be useful insect repellents. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention is generally related to a cell which is inserted in the fluid flow line in such a manner to permit non-invasive monitoring of the fluid and is specifically directed to an assembly permitting sensors to interface with the fluid through semi-permeable membranes thereby allowing for photochemical reaction which may in turn be optically monitored through windows provided in the sensors. This combination provides for non-invasive real time monitoring of various entities contained in the fluid.
2. Description of the Prior Art
In most medical applications where fluids are either being introduced into the body or withdrawn from the body, the purity of the fluid must be maintained. Where such fluids have to be pumped, monitored, or subjected to temperature and other environmental controls, these activities must be done in a non-invasive manner. Over the years, a widely used non-invasive monitoring technique has been developed where the fluid is exposed to a light emitting device and a sensor, wherein the reflected light spectrum as modified by the photochemical reactions between the sensor elements and certain specific constituents within the fluid is monitored to determine the presence or lack of specific constituents, as well as the concentration of the constituents. The practice has become a widely accepted method for monitoring and diagnosing the condition of human blood. This methodology is particularly useful during the conduct of Cardio Pulmonary Bypass during open heart surgery because the information is received by the technician immediately.
A well known device specifically directed to directing a flow of blood through a photochemical monitoring zone is the Cardiovascular Devices Inc. (CDI) flow through cell, models 6640, 6630 and 6620, generally shown and described in U.S. Pat. Nos. 4,460,820 and 4,786,474. As there shown, the cell includes a flow through body having a window opening covered by a membrane. Sensors are seated adjacent to the membrane and may monitor the blood passing through the cell. While this device has gained widespread commercial acceptance over the last decade, there are several drawbacks which make it cost prohibitive in certain applications and certainly increase the costs of treatment wherever it is used as part of the diagnostic regimen. This is particularly true since such units are disposable and costs associated with their use is repeated each time the technique is employed.
One of the problems driving up the cost of the CDI cell is the assembly design coupled with the labor intensive methods required for fabrication. As particularly described in U.S. Pat. No. 4,640,820, the flow through cell includes a membrane support and a pair of membranes for isolating the sensors from the flowing blood. The means for mounting the membranes in the window under the lens of the sensor includes a groove in the support structure for receiving the edge portions of the membrane. Typically, two different membranes are utilized, each having a different optical response and a different permeability factor, depending on the application. In order to mount the membranes in the window, the edge portion of the first membrane is extended into the groove in the structure separating the two windows and the second membrane is extended over the retaining means outwardly from the groove and then into the groove in order to form a smooth transition with the first membrane. Specifically, one of the membranes is wrapped partially around the retainer which is then inserted in the groove.
As described in the '820 patent, a region of the end portion of one membrane extends beyond the end portion of the second membrane within the groove and is adhered to the wall of the groove. This allows a portion of the first membrane to be adhered directly to the support even if only one face of the membrane is capable of being adhesively attached. It is this wrapping feature which establishes the proper firmness of the membranes in the assembly.
While effective for the purpose of joining the adjacent edges of the two membranes, the remaining three sides of each of the two membranes must also be sealed in a separate groove around the perimeter of the cell and the quality of this seal is impaired by the excess material resulting from the aforementioned wrapping technique. The complicated wrapping technique and placement steps as defined in the '820 patent has resulted in an increase in costs while at the same time reducing the reliability of the assembly due to both the skill required and the narrow tolerances which must be maintained to assure a proper fit of the membranes in the cell.
Therefore, there remains a need for a high quality, low cost cell capable of being used in the existing equipment as a disposable flow through cell for non-invasive monitoring of bodily fluids, especially blood.
SUMMARY OF THE INVENTION
The subject invention is specifically directed to an improved flow through cell which maintains the high quality and high reliability standards of the prior art cells while being constructed with much less complexity and at a lower cost. In the preferred embodiment, the flow through cell of the subject invention includes a flow through body having nipple type connectors at opposite ends whereby the body may be inserted, in-line, in a fluid flow line as is customary for such devices. The upper side of the body is open to provide a window through which photochemical sensors and photo-optical transducers may monitor the fluid flowing therethrough a pair of stepped recess seats are provided about the perimeter of the window opening to accommodate the frame-membrane assembly. The geometry of the frame provides bonding surfaces which easily mate with the aforementioned recess seats and bond reliably with normal adhesives using easily learned skills.
The frame generally defines a pair of window openings which accommodate two membranes. A groove surrounds the perimeter of the two windows in the frame structure and the two windows share the groove between them such that the groove generally defines a squared off figure eight and provides a groove on all four sides of each membrane window. A pair of membranes are loosely placed over the windows and automatically aligned by the step geometry of the frame used in the assembly of the frame to the body. A retaining member which is generally shaped so as to fill the figure eight groove around the two windows, is pressed into the groove thereby trapping all four edges of both membranes simultaneously between the retainer inner and outer wall surfaces and the frame groove inner and outer wall surfaces. An adhesive may be used to supplement this mechanical assembly prior to final assembly to the body member.
The frame also serves as the receiver for the sensors and permits the sensors to be placed in close proximity to the membranes. In the preferred embodiment, a removable cover is placed in the frame so as to guard against contamination, damage to the membranes and leakage prior to insertion of the sensor.
Typically, the membrane and frame are secured in the cell by adhesive means, sonic welding or the like. The retainer and membranes are likewise secured in the assembly.
The flow through cell structure of the present invention permits the membranes to be assembled flat on the frame and cell body, and to be secured in place with a retainer "clamp". This greatly reduces the labor required in assembly, it relieves the tolerances required for a secure membrane assembly, and it reduces the skill level required for assembly when compared to the prior art devices. The clamping provided by the retainer assures proper tautness of the membranes in the window opening, assuring consistent and proper responsiveness of the sensor.
It is, therefore, an objective and feature of the subject invention to provide an improved flow through cell for non-invasive monitoring of fluids flowing therethrough.
It is a further objective and feature of the subject invention to provide a flow through assembly which is of high reliability while at the same time is simple to manufacture and assemble.
It is an additional objective and feature of the subject invention to provide a flow through cell maintaining the high performance standards of prior art cells while at the same time permitting a reduction in cost through the relief of tolerance requirements, reduction of labor cost and improvement in reliability and yield of assemblies produced.
Other objectives and features will be readily apparent from the accompanying drawings and description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the flow through cell assembly of the preferred embodiment.
FIG. 2 is a side plan view of the assembled flow through cell of FIG. 1.
FIG. 3 is a longitudinal cross-sectional of the flow through cell as shown in FIG. 2, and taken along the lines 3--3 of FIG. 4.
FIG. 4 is a lateral cross-sectional view of the flow through cell taken along lines 4--4 of FIG. 2.
FIG. 5 is a lateral cross-sectional view of the flow through cell taken along lines 5--5 of FIG. 2.
FIG. 6 is a lateral cross-sectional view of the flow through cell taken along lines 5.5 of FIG. 2 and similar to FIG. 5, but showing the cover removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The components of the flow through cell 10 of the preferred embodiment are shown in exploded, pre-assembled form in FIG. 1.
The cell body 12 includes an axial, through chamber 14. The end walls 16 and 18 of the body include openings in communication with the chamber 14 and having integral connectors, such as, by way of example, the ribbed nipple connectors 20, by which the cell may be coupled, in-line, in a fluid flow line.
The upper side of the body 12 is open, providing a window 22. As best shown in FIGS. 1 and 4-6, the perimeter of the window 22 is defined by a first recessed seat of ledge 24. Outboard of ledge 24 is a stepped or raised second recessed seat 26. Between the seats 24 and 26 is a longitudinal groove or channel 28 running down both sides of the body 12. A raised outer wall 30 defines the upper peripheral edge of the cell body 12.
A retainer 32 is adapted to allow it to fit against the first seat 24, inwardly of the channel 28, as best shown in FIGS. 3-6. The retainer 32 is substantially flat and includes outer perimeter walls 34 and a crossmember 36 for defining two sensor windows 38 and 39, which are aligned with cell body window 22, when assembled.
Typically, a separate membrane 42 and 40 is associated with each window 38 and 39, respectively, although a single membrane could be used. The inner edge 44 of membrane 42 and the inner edge 46 of membrane 40 are in an overlapping relationship and each are located over crossmember 36 of the retainer 32. The remaining outer edge portion 48 and 50 of the respective membranes extend beyond the outer perimeter walls 34 of the retainer 32.
A frame 52, as best shown in FIG. 1, has a substantially rectangular base 54 with interior openings or windows 56 and 58 which correspond with the windows 38 and 39, respectively, of the retainer 32. As best shown in FIGS. 3-6, the outer perimeter edge 60 of the frame base 54 fits snugly in the recessed seat 26. The frame has a pair of longitudinal, downwardly extending runners 62 and 64, adapted to be received in the channel 28 of the cell body. The frame 52 is positioned against the retainer 32 and the membranes 40 and 42 such that the outer edges 44, 46, 48 and 50 are trapped in a mating groove to the retainer 32 in the frame 52 causing the edges 44, 46, 48 and 50 of membranes 40 and 42 to fold around the walls 34 and cross member 36 of the retainer 32, thereby clamping the membranes in place with the desired firmness. Typically, adhesive may be applied to the contact surfaces of the retainer 32 and the frame 52 to secure the assembly. In the preferred embodiment, the frame 52 includes a frame crossmember 59 positioned in alignment with the crossmember of the retainer to engage the overlapping edges 44 and 46 of the two membranes 40 and 42, respectively.
An upper, sensor receptive chamber 63 is provided in the frame 52 and is defined by the upstanding wall 65. The various slots and openings in the wall 65 are adapted to mate with the specific sensors being utilized and are not an important feature of the invention. However, openings 66 are typically designed to receive detent retainers for holding the flow through cell in the appropriate position on the sensor body, and the slots 68 and 70 provide for proper alignment.
A cover assembly 72 is provided for protecting the exposed membranes 40 and 42 against damage during storage and shipment for supporting the membranes against internal fluid pressures that might exist prior to inserting the sensors, for guarding against fluid leaks which might occur through the semi-permeable membranes prior to inserting the sensors and for protecting the membrane surface from contamination during shipment, storage or use prior to inserting the sensor. In the preferred embodiment, a resilient seal 74 is positioned on the perimeter of the cover assembly 72 to seal between the chamber wall 65 and the membrane window openings 56 and 58 of the frame 52. The cover includes a plurality of detent tabs 76 adapted to be received in the receptive openings 66 of the frame wall 65 for securing the cover in place. Alignment tabs 78 may also be provided to mate with slots 68, 70, where desired. Upstanding thumb and finger tabs 80 and 82 are provided whereby the cover may be grasped and slightly squeezed so as to release the detent tabs 76 for removing the cover from the assembly. In the preferred embodiment, and as best shown in FIGS. 3, 5 and 6, the cover includes lower abutment surfaces 84 and 86, which engage the respective membranes and maintain them in a flat condition during shipment, storage and internal pressurization without a sensor present.
The assembled cell comprises the body 12, the retainer 32, the membranes 40 and 42, and the frame 52. The removable cover comprises the cover assembly 72 and the seal 74. When in use, the cover and seal are removed and the sensors are inserted in place of the cover in the sensor chamber or receptacle 63 of the frame of the assembled cell and positioned relative to the respective membranes 40 and 42 in alignment with the respective frame windows 56 and 58.
From the foregoing, it will be readily understood that the invention provides an improved, reliable, high quality flow through cell assembly. While certain features and embodiments of the invention have been described in detail herein, it will be apparent the invention includes all modifications and enhancements within the scope and spirit of the following claims. | A flow through cell for non-invasive monitoring of fluids flowing therethrough includes a membrane covered view window through which sensors may monitor the fluids. The membranes are secured in position by a frame and retainer assembly with the frame and retainer clamping the membranes in place between the frame support structure and the retainer. The frame is snugly fitted into the cell and includes a sensor receptive chamber for positioning the sensors in the window and in position with the membranes. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 14/ 584,368, filed December 29, 2014, which claims the benefit of U.S. Provisional Patent Application Ser. Nos. 61/922,572 and 61/922,582, each filed Dec. 31, 2013, the disclosures of which are expressly incorporated by reference herein.
FIELD
Provided herein are 5-fluoro-4-imino-3-(alkyl/substituted alkyl)1-(arylsulfonyl)-3,4-dihydropyrimidin-2(1H)-one and processes for their preparation.
BACKGROUND AND SUMMARY
U.S. patent application Ser. No. 13/090,616, U.S. Pub. No. 2011/0263627, describes inter alia certain N3-substituted-N1-sulfonyl-5-fluoropyrimidinone compounds and their use as fungicides. The disclosure of the application is expressly incorporated by reference herein. This patent describes various routes to generate N3-substituted-N1-sulfonyl-5-fluoropyrimidinone compounds. It may be advantageous to provide more direct and efficient methods for the preparation, isolation, and purification of N3-substituted-N1-sulfonyl-5-fluoropyrimidinone fungicides and related compounds, e.g., by the use of reagents and/or chemical intermediates and isolation and purification techniques which provide improved time and cost efficiency.
Provided herein are 5-fluoro-4-imino-3-(alkyl/substituted alkyl)-1-(arylsulfonyl)-3,4-dihydropyrimidin-2(1H)-one and processes for their preparation. In one embodiment, provided herein is a process for the preparation of compounds of Formula III:
wherein R 1 is selected from:
and R 2 is selected from:
which comprises contacting compounds of Formula II with a base, such as an alkali carbonate, e.g., sodium-, potassium-, cesium-, and lithium carbonate (Na 2 CO 3 , K 2 CO 3 , Cs 2 CO 3 , and Li 2 CO 3 , respectively) or an alkali alkoxide, for example, potassium tert-butoxide (KO t Bu) and an alkylating agent, such as an alkyl halide of Formula R 2 —X, wherein R 2 is as previously defined and X is a halogen, e.g., iodine, bromine, and chlorine, in a polar solvent, such as N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), dimethylacetamide (DMA), N-methylpyrrolidone (NMP), acetonitrile (CH 3 CN), and the like, at concentrations from about 0.1 molar (M) to about 3 M. In some embodiments, a molar ratio of compounds of Formula II to the base is from about 3:1 to about 1:1 and a molar ratio of compounds of Formula II to alkylating agent is from about 1:1 to about 3:1. In other embodiments, molar ratios of compounds of Formula II to the base and compounds of Formula II to the alkylating agent a about 2:1 and about 1:3, respectively, are used. In some embodiments, the reactions are conducted at temperatures between −78° C. and 90° C., and in other embodiments, the reactions are conducted between 22° C. and 60° C.
It will be understood by those skilled in the art that manipulation of the reaction parameters described above may result in the formation of product mixtures comprised of compounds of Formulas II, III, and IV, as shown in Scheme 1, wherein the ratios of compounds of Formulas II, III, and IV formed is from about 0:2:1 to about 1:2:0. In some embodiments, compositions comprising mixtures of compounds of Formulas II and III are preferred, as isolation and purification can be achieved through precipitation and recrystallization, and the intermediate compounds of Formula II can be recovered and recycled. In contrast, compositions comprising mixtures of compounds of Formulas III and IV require chromatographic separation to give III along with the undesired dialkylated by-product of Formula IV.
In another embodiment, the desired crude composition, i.e., mixtures of compounds of Formula II and compounds of Formula III, wherein R 1 is methoxy (OCH 3 ) and R 2 is methyl (CH 3 ), is obtained through contacting a compound of Formula II with Li 2 CO 3 and methyl iodide (CH 3 I) in DMF (1.0 M) in a molar ratio of about 1:0.6:3 at 45° C. Upon completion, dilution of the crude composition with a polar, aprotic solvent, such as CH 3 CN, wherein the ratio of CH 3 CN:DMF is from about 2:1 to about 1:2, followed by an aqueous solution of sodium thiosulfate (Na 2 S 2 O 3 ) with a pH from about 8 to about 10.5, wherein the ratio of 2.5 wt. % aqueous Na 2 S 2 O 3 :DMF is from about 1:2 to about 3:1, affords a precipitate which is isolable by filtration. In one embodiment, the ratio of CH 3 CN:DMF is about 1:2 and the ratio of 2.5% aqueous Na 2 S 2 O 3 :DMF is about 1:1, and the resultant solid is further purified by crystallization/precipitation from a warmed solution, about 30° C.-40° C., of the solid h a solution of a polar, aprotic solvent, such as CH 3 CN, by the addition of water (H 2 O), wherein the ratio of H 2 O:CH 3 CN is from about 1:2 to about 3:1, to give the purified compound of Formula III, and in another embodiment the ratio of H 2 O:CH 3 CN to affect precipitation of pure III is about 2:1.
In another embodiment, compounds of Formula II may be prepared by contacting compounds of Formula I with bis-N,O-trimetliyisilylacetamide (BSA) at an elevated temperature, such as 70° C., for a period of about 1 hour (h), followed by cooling and contacting the solution containing the protected pyrimidinol with a substituted benzene sulfonyl chloride, generalized by R 1 —PhSO 2 Cl, wherein R 1 is as previously defined, at 20-25° C. In some embodiments, the molar ratio of the compound of Formula I to BSA and the sulfonyl chloride is about 1:3:1.1, respectively, and in another embodiment reducing the molar ratio of the reactants to about 1:1.1:1.1 affords improved yields.
The term “alkyl” refers to a branched, unbranched, or saturated cyclic carbon chain, including, but not limited to, methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tertiary butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.
The term “alkenyl” refers to a branched, unbranched or cyclic carbon chain containing one or more double bonds including, but not limited to, ethenyl, propenyl, butenyl, isopropenyl, isobutenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and the like.
The term “aryl” refers to any aromatic, mono- or bi-cyclic, containing 0 heteroatoms.
The term “heterocycle” refers to any aromatic or non-aromatic ring, mono- or bi-cyclic, containing one or more heteroatoms.
The term “alkoxy” refers to an OR substituent.
The term “halogen” or “halo” refers to one or more halogen atoms, defined as F, Cl, Br, and I.
The term “haloalkyl” refers to an alkyl, which is substituted with Cl, F, I, or Br or any combination thereof.
Throughout the disclosure, references to the compounds of Formulas I, II, III, and IV are read as also including optical isomers and salts. Exemplary salts may include: hydrochloride, hydrobromide, hydroiodide, and the like. Additionally, the compounds of Formulas I, II, III, and IV may include tautomeric forms.
Certain compounds disclosed in this document can exist as one or more isomers. It will be appreciated by those skilled in the art that one isomer may be more active than the others. The structures disclosed in the present disclosure are drawn in only one geometric form for clarity, but are intended to represent all geometric and tautomeric forms of the molecule.
In one exemplary embodiment, a method of making compounds of Formula III is provided. The method includes contacting a compound of Formula II with an alkali alkoxide and an alkylating agent, and forming a compound of Formula III:
wherein R 1 is selected from the group consisting of:
and
R 2 is selected from the group consisting of:
In a more particular embodiment, the contacting step is carried out between 22° C. and 60° C.
In a more particular embodiment of any of the above embodiments, the contacting step further includes a solvent selected from the group consisting of DMF, DMSO, DMA, NMP, and CH 3 CN.
In a more particular embodiment of any of the above embodiments, the alkali alkoxide is selected from the group consisting of: KO t Bu, CH 3 ONa, CH 3 CH 2 ONa, CH 3 CH 2 OLi, CH 3 OLi, CH 3 CH 2 OK, and CH3CH 2 ONa.
In a more particular embodiment of any of the above embodiments, the alkylating agent is selected from the group consisting of: alkyl halides and benzyl halides.
In a more particular embodiment of any of the above embodiments, the alkyl halide and benzyl halide are selected from methyl iodide (CH 3 I), ethyl iodide (C 2 H 5 I), and benzyl bromide (BnBr).
In a more particular embodiment of any of the above embodiments, the alkali alkoxide is KO t Bu, and the solvent is DMF.
In a more particular embodiment of any of the above embodiments, a molar ratio of Compound II to alkali alkoxide is from about 3:1 to about 1:1 and a molar ratio of Compound II to alkylating agent is from about 1:1 to about 3:1. In an even more particular embodiment, a molar ratio of Compound II to alkali alkoxide base is about 2:1 a molar ratio of Compound II to alkylating agent is 1:3.
In a more particular embodiment of any of the above embodiments, the method includes diluting a completed reaction mixture with CH 3 CN and 2.5% aqueous Na 2 S 2 O 3 . In an even more particular embodiment, a ratio of DMF to CH 3 CN is from about 1:1 to about 3:1 and a ratio of DMF to 2.5% aqueous Na 2 S 2 O 3 is from about 1:2 to about 2.1. In another more particular embodiment, a ratio of DMF to CH 3 CN is about 2:1 and a ratio of DMF to 2.5% aqueous Na 2 S 2 O 3 is about 1:1.
In another embodiment, a method of preparing a compound of Formula II is provided. The method includes contacting a compound of Formula I with bis-N,O-trimethylsilylacetamide; and forming a compound of Formula II
wherein R 1 is selected from the group consisting of:
and
R 2 is selected from the group consisting of:
wherein a molar ratio of compound Ito bis-N,O-trimethylsilylacetamide (BSA) is 1:1.1. and the contacting step is carried out at about 22° C. to about 70° C.
In a more particular embodiment, the contacting step further includes contacting compound I with CH 3 CN. In another more particular embodiment, the method includes contacting a BSA treated reaction mixture with an arylsulfonyl chloride. In an even more particular embodiment, a molar ratio of Compound I to arylsulfonyl chloride is from about 1:2 to about 2:1, In another more particular embodiment, a molar ratio of Compound I to arylsulfonyl chloride is 1:1.1.
The embodiments described above are intended merely to be exemplary, and those skilled in the art will recognize, or will be able to ascertain using no more than routine experimentation, numerous equivalents of specific compounds, materials, and procedures. All such equivalents are considered to be within the scope of the invention and are encompassed by the appended claims.
DETAILED DESCRIPTION
5-Fluoro-4-imino-3-(alkyl/substituted alkyl)-1-(arylsulfonyl)-3,4-dihydro-pyrimidin-2(1H)-one as shown in Examples 1-2.
Example 1
Preparation of 4-amino-5-fluoro-1-(phenylsulfonyl)pyrimidin-2(1H)-one (1):
To a dry 500 milliliter (mL) round bottom flask equipped with a mechanical stirrer, nitrogen inlet, addition funnel, thermometer, and reflux condenser were added 5-fluorocytocine (20.0 grams (g), 155 millimole (mmol)) and CH 3 CN (100 mL). To the resulting mixture was added BSA (34.7 g, 170 mmol) in one portion and the reaction was warmed to 70° C. and stirred for 30 minutes (min). The resulting homogeneous solution was cooled to 5° C. with an ice bath and treated dropwise with benzenesulfonyl chloride. The reaction was stirred at 0° C.-5° C. for 1 h and then overnight at room temperature. The resulting pale yellow suspension was poured into cold H 2 O (1.5 liters (L)) and stirred vigorously for 1 h. The resulting solid was collected by vacuum filtration, washed with H 2 O, and dried under vacuum overnight at 40° C. to give 4-amino-5-fluoro-1-(phenylsulfonyl)pyrimidin-2(1H)-one (29.9 g, 72%) as a powdery white solid: 1 H NMR (400 MHz, DMSO-d 6 ) δ 8.56 (s, 1H), 8.35-8.26 (m, 2H), 8.07-7.98 (m. 2H), 7.84-7.74 (m, 1H), 7.72-7.61 (m, 2H); 19 F NMR (376 MHz, DMSO-d 6 ) δ −163.46; ESIMS m/z 270 ([M+H] + ).
The following compounds 1-3 in Table 1a were made in accordance with the reaction depicted in Scheme 1 and the procedures described in Example 1. Characterization data for compounds 1-3 are shown in Table 1b.
TABLE 1a
Compound
Yield
Number
R 1
Appearance
(%)
1
H
Powdery White Solid
72
2
CH 3
Powdery White Solid
61
3
OCH 3
Powdery White Solid
57
TABLE 1b
13 C NMR or
Compound
Mass
19 F NMR
Number
Spec.
1 H NMR (δ) a
(δ) b,c
1
ESIMS
1 H NMR (DMSO-
19 F NMR
m/z 270
d 6 ) δ 8.56 (s, 1H),
(DMSO-d 6 ) δ −163.46
([M + H] + )
8.35-8.26 (m, 2H),
8.07-7.98 (m, 2H),
7.84-7.74 (m, 1H),
7.72-7.61 (m, 2H)
2
ESIMS
1 H NMR (DMSO-
19 F NMR
m/z 284
d 6 ) δ 8.54 (s, 1H),
(DMSO-d 6 ) δ −163.62
([M + H] + )
8.40-8.16 (m, 2H),
8.05-7.76 (m, 2H),
7.66-7.36 (m, 2H),
2.41 (s, 3H)
3
ESIMS
1 H NMR (CDCl 3 )
19 F NMR
m/z 300
δ 8.10-7.91 (m,
(CDCl 3 ) δ −158.58
([M + H] + )
2H), 7.73 (d, J = 5.4 Hz, 2H),
7.11-6.94 (m, 2H),
3.90 (s, 3H), 3.32 (d, J = 0.6 Hz,
3H)
a All 1 H NMR data measured at 400 MHz unless otherwise noted.
b All 13 C NMR data measured at 101 MHz unless otherwise noted.
c All 19 F NMR data measured at 376 MHz unless otherwise noted.
Example 2
Preparation of 5-fluoro-4-imino-3-methyl-1-tosyl-3,4-dihydropyrimidin-2(1H)-one (5):
To a mixture of 4-amino-5-fluoro-1-tosylpyrimidin-2(1H)-one (20 mmol, 5.66 g) and Li 2 CO 3 (0.880 g, 12.0 mmol) in DMF (20 mL) was added CH 3 I (8.52 g, 60 mmol), and the resulting mixture was warmed to 40° C. and stirred for 5 h. The reaction mixture was cooled to room temperature, diluted with CH 3 CN (10 mL), and treated with 2.5% aqueous Na 2 S 2 O 3 (20 mL). The resulting mixture was stirred at room temperature for 10 min and the solids were collected by filtration. The filter cake was washed with aqueous CH 3 CN (10% CH 3 CN in H 2 O) and air dried for 2 h. The cake was dissolved in CH 3 CN (15 mL) at 40° C. and the solution was treated with H 2 O (30 mL). The resulting suspension was cooled to room temperature, stirred for 2.5 h, and filtered. The filter cake was again washed with 10% aqueous CH 3 CN and then dried under vacuum at 50° C. to give the title compound (2.70 g, 45%) as a white solid: mp 156-158° C.; 1 H NMR (400 MHz, DMSO-d 6 ) δ 8.54 (d, J=2.3 Hz, 1H), 7.99 (dd, J=6.0, 0.6 Hz, 1H), 7.95-7.89 (m, 2H), 7.53-7.45 (m, 2H), 3.12 (d, J=0.7 Hz, 3H), 2.42 (s, 3H); 19 F NMR (376 MHz, DMSO-d 6 ) −157.86 (s); ESIMS m/z 298 ([M+H] + ).
The following compounds 4-6 in Table 2a were made in accordance with the reaction depicted in Scheme 2 and the procedures described in Example 2. Characterization data for compounds 4-6 are shown in Table 2b.
TABLE 2a
Compound
Yield
Number
R 1
R 2
Appearance
(%)
4
H
CH 3
White Solid
64
5
CH 3
CH 3
White Solid
45
6
OCH 3
CH 3
White Solid
62
TABLE 2b
13 C NMR or
Compound
Mass
19 F NMR
Number
Spec.
1 H NMR (δ) a
(δ) b,c
4
ESIMS
1 H NMR (CDCl 3 ) δ
19 F NMR
m/z 284
8.14-8.02 (m, 2H),
(CDCl 3 ) δ −158.05
([M + H] + )
7.88-7.67 (m, 3H),
7.67-7.50 (m, 2H),
3.31 (d, J = 0.7 Hz,
3H)
5
ESIMS
1 H NMR (CDCl 3 ) δ
19 F NMR
m/z 298
8.54 (d, J = 2.3 Hz,
(CDCl 3 )
([M + H] + )
1H), 7.99 (dd, J = 6.0,
δ 157.86 (s)
0.6 Hz, 1H),
7.95-7.89 (m, 2H),
7.53-7.45 (m, 2H),
3.12 (d, J = 0.7 Hz,
3H), 2.42 (s, 3H)
6
ESIMS
1 H NMR (CDCl 3 ) δ
19 F NMR
m/z 314
8.10-7.91 (m, 2H),
(CDCl 3 ) δ −158.58
([M + H] + )
7.73 (d, J = 5.4 Hz,
2H), 7.11-6.94 (m,
2H), 3.90 (s, 3H),
3.32 (d, J = 0.6 Hz,
3H)
a All 1 H NMR data measured at 400 MHz unless otherwise noted.
b All 13 C NMR data measured at 101 MHz unless otherwise noted.
c All 19 F NMR data measured at 376 MHz unless otherwise noted. | Provided herein are 5-fluoro-4-imino-3-(alkyl/substituted alkyl)-1-(arylsulfonyl)3,4-dihydropyrimidin-2(1H)-one and processes for their preparation which may include the use of an alkali alkoxide and an alkylating agent | 0 |
This Application is a 371 of PCT/JP2006/301859, filed on Feb. 3, 2006, which claim priority of Japan 2005-046378, filed on Feb. 23, 2005.
FIELD OF THE INVENTION
The present invention relates to a membrane element of a membrane separation device for use in filtration or concentration of clean water or wastewater, and more particularly to a membrane element that is capable of maintaining a stable performance even if it has an enlarged size with a short side of about 0.5 m and a long side of about 1 m.
BACKGROUND OF THE INVENTION
As a membrane separation device of this type, an immersion type membrane separation device having plural membrane elements disposed parallel to each other with a given interval (5-10 mm) is known. These membrane elements each are made up of, for example, a plate for filtration that is made of a resin and has a rectangular flat plate shape, defining a filtered water flow passage that has a first end opening to the surface of the plate and a second end communicating to a filtered water suction conduit, an organic filtration membrane covering the surface of this resin plate, and a spacer disposed between the plate and the organic filtration membrane to have a given clearance.
The membrane separation device has membrane units each made up of a plurality of the aforesaid membrane elements that have the filtered water suction conduits connected together to have a common conduit, and these membrane units are immersed in water to be treated within a treated water tank, in which a negative pressure is applied to the filtered water flow passage to filter the water to be treated by an organic filtration membrane, thus obtaining filtered water. In the aforesaid membrane separation device, an air diffuser for generating air bubbles is disposed in a lower portion of each membrane unit, so that air bubbles generated move upward between the membrane elements to generate a cross-flow. This cross-flow removes cake layer formed on the membrane surface as the filtration progresses. This membrane separation device can deal with various filtration volumes by increasing or decreasing the number of membrane elements or increasing or decreasing the effective membrane area, and thus can be used for various purposes from a small scale filtration to a large scale wastewater treatment plant.
These membrane elements are subjected to pressure by the aforesaid cross-flow and therefore a measure to prevent the organic filtration membrane, which is disposed over the surface of a resin plate for filtration, from being peeled off by fixing the organic filtration membrane to a peripheral portion of the resin plate by adhesive has been employed. However, according to this fixing manner, the organic filtration membrane is fixed to the resin plate by having adhesive impregnated in nonwoven fabric that acts as a substrate of the organic filtration membrane. Therefore, the fixing strength is varied depending on the strength, durability or chemical resistance of the cured adhesive and there may be a problem in that the fixing strength is relatively low, the working environment is deteriorated by solvent, or the drying and curing takes time. Also, there has been used a method in which the fixing is made by a tape, but this physical fixing poses a problem in that the filter membrane is easy to be peeled off. Therefore, there have been proposed manufacturing methods disclosed in such as in Japanese Patent No. 3028900 and Japanese Patent Application Laid-open No. 2001-120958.
Patent Document 1: Japanese Patent No. 3028900 Patent Document 2: Japanese Patent Application Laid-open No. 2001-120958 Patent Document 3: Japanese Patent Application Laid-open No. Hei-5-68943 (page 3 paragraph [0002]) Patent Document 4: Japanese Patent Application Laid-open No. Sho-58-30378 (page 2 right upper column line 15 to left lower column line 7)
The aforesaid Japanese Patent No. 3028900 discloses a method in which a thermoplastic resin plate and an organic filtration membrane are fusion bonded together by ultrasonic wave. The aforesaid Japanese Patent Application Laid-open No. 2001-120958 discloses a method in which plural protrusions are formed on a thermoplastic resin plate of a fusion bonded portion to have a difference in fusing strength by the protrusions, thereby suppressing the occurrence of fatigue cracking due to heat applied to a microporous organic filter membrane during fusion bonding.
Japanese Patent No. 3028900 discloses in paragraph [0010] that nonwoven fabric made of such as saturated polyester is used as a substrate of a filtration membrane 2 ; and when the temperature in fusion bonding this substrate to a plate for filtration 1 made of such as an ABS resin by ultrasonic wave is lower than 140° C., the plate 1 is fused and the fused resin is impregnated into the nonwoven fabric so that the filtration membrane 2 can be fixed to the plate 1 ; and when the temperature is higher than 140° C., both the plate 1 and the nonwoven fabric are fused so that the filtration membrane 2 can be fixed to the plate 2 . However, in the fusion bonding by ultrasonic wave, which tends to cause uneven heating, controlling the temperature to below 140° C. is not preferable from the view point of securing a stable performance of a membrane element, and therefore it is assumed that the temperature was controlled to above 140° C. This is also apparent from Japanese Patent Application Laid-open No. 2001-120958 that discloses that nonwoven fabric made of synthetic resin fibers, which acts as a substrate, is partially fused and hence fatigue cracking is caused during the ultrasonic fusion bonding. Japanese Patent Application Laid-open No. 2001-120958 discloses a prior art in paragraphs [0007] to [0008] and in FIGS. 10 and 11, in which a filtration membrane 22B is pressed to a plate for filtration 22A by a rotating rotary horn 31 and fusion bonding is made by using ultrasonic wave, and the filtration membrane 22B is fusion bonded to the plate 22A by fusing the plate 22A thereby deforming the same into groove-like recesses in a water shutoff portion S. Since it discloses that fatigue cracking is easy to occur, it is assumable that the nonwoven fabric of synthetic resin fibers, which acts as the substrate, is partially fused.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
The methods disclosed in the aforesaid Japanese Patent No. 3028900 and Japanese Patent Application Laid-open No. 2001-120958 are intended to fusion bond a thermoplastic resin plate for filtration and a filtration membrane together rather than preventing fatigue cracking due to the fusion of nonwoven fabric of synthetic resin fibers, which acts as a substrate. In Japanese Patent Application Laid-open No. 2001-120958, an effect of preventing fatigue cracking may be obtainable by providing a protrusion on a thermoplastic resin plate and ultrasonic fusion bonding is made through this protrusion. However, in a case of breakage of the filtration membrane, a membrane cannot be replaced with a new one due to the deformation of the protrusion of the thermoplastic resin plate caused during ultrasonic fusion bonding, which necessitates the replacement of all the membrane element. This is not preferable from the view point of cost and waste treatment. Also, the manufacturing of a large sized membrane element as mentioned above by the ultrasonic fusion bonding invites increase in size of a facility or plant and hence increase in cost (cf. Japanese Patent Application Laid-open No. Hei-5-68943 and Japanese Patent Application Laid-open No. Sho-58-30378).
MEANS TO SOLVE THE PROBLEMS
The present invention has been conceived in consideration of the above problems. It is an object of the present invention to provide a method of manufacturing a membrane element that is capable of easily and securely fixing a thermoplastic resin plate for filtration to a microporous organic filtration membrane, and reusing a membrane element by replacing a membrane.
Specifically, according to the present invention, there is provided a membrane element, in which a microporous filtration membrane having micro pores including nonwoven fabric made of synthetic resin fibers, which nonwoven fabric acting as a substrate, is joined to a flat surface of a peripheral part of a thermoplastic resin plate for filtration (claim 1 ). In the membrane element, the peripheral part of the thermoplastic resin plate has a recess on the flat surface by being joined to the microporous filtration membrane without fusing the nonwoven fabric acting as the substrate (claim 2 ). In each of the aforesaid membrane elements, the microporous filtration membrane is joined to the flat surface of the peripheral part of the thermoplastic resin plate by applying pressure to the thermoplastic resin plate via the microporous filtration membrane by a hot plate whose temperature is controlled (claim 3 ). In the membrane element claimed in claim 3 , the microporous filtration membrane is joined to the thermoplastic resin plate by applying pressure to the thermoplastic resin plate via the microporous filtration membrane by the hot plate that has a frame-like shape corresponding to the shape of a joined portion of the microporous filtration membrane and the thermoplastic resin plate (claim 4 ). The frame-like hot plate has four rounded corners and four corners of the joined portion of the microporous filtration membrane and the thermoplastic resin plate are rounded (claim 5 ). In the membrane element as claimed in claim 3 , the temperature of the hot plate is controlled to be equal to or lower than the fusing point of the nonwoven fabric acting as the substrate and equal to or higher than the Vicat softening temperature of the thermoplastic resin plate (claim 6 ). The temperature of the hot plate is controlled to be equal to or lower than the deflection temperature under load of the nonwoven fabric acting as the substrate (claim 7 ). In each of the aforesaid membrane elements, a material of the nonwoven fabric acting as the substrate is polyester or polypropylene, and a material of the thermoplastic resin plate is polyethylene, ABS or polyvinylchloride (claim 8 ).
ADVANTAGES OF THE INVENTION
In the invention (claim 1 ), since the microporous filtration membrane is joined to the flat surface of the peripheral part of the thermoplastic resin plate for filtration, working for joining the microporous filtration membrane to the plate is not needed, which can contribute to the cost reduction of the membrane element. The invention (claim 2 ), in which the peripheral part of the thermoplastic resin plate has a recess on the flat surface by being joined to the microporous filtration membrane without fusing the nonwoven fabric acting as the substrate, produces an additional advantage in that since the filtration membrane is drawn into the recess and therefore can be kept in tension, a membrane element which can contribute to obtain uniform filtration performance is obtainable. In the invention (claim 3 ), it is possible to obtain a membrane element enabling the filtration membrane to be kept in tension and joined to the peripheral part of the thermoplastic resin plate by the application of pressure by the hot plate. In the invention (claim 4 ), in addition to the above advantages, the application of the pressure by the hot plate can be achieved by one action, which contributes to the simplification of the manufacturing process and is advantageous in manufacturing a large-sized membrane element. The invention (claim 5 ) can contribute to the improvement of the aforesaid advantages. In the invention (claim 6 ), the temperature is set to be within such a range as to soften the thermoplastic resin plate while not fusing the nonwoven fabric acting as the substrate. Therefore, the nonwoven fabric and the thermoplastic resin plate are not fused and mixed together. Thus, the joining can be achieved with recesses and protrusions of the surface of the nonwoven fabric held pressed into the softened thermoplastic resin plate, and hence the thermoplastic resin plate can be joined to the microporous filtration membrane with no great change in shape of the surface of the thermoplastic resin plate while maintaining the strength of the nonwoven fabric. It is also possible to replace a polymer filtration membrane by reutilizing the thermoplastic resin plate in breakage or deterioration of the microporous filtration membrane. In the invention (claim 7 ), it is possible to obtain a membrane element that can maintain the strength of the nonwoven fabric with a better condition. In the invention (claim 8 ), it is possible to obtain various membrane elements that can produce the above advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 are views of a membrane element of the present invention.
FIGS. 2 are views for explaining the manufacturing procedures of a membrane element of the present invention.
FIG. 3 is a view illustrating an essential portion of the manufacturing procedures of a membrane element of the present invention.
FIG. 4 is a view illustrating an essential portion of the manufacturing procedures of a conventional membrane element.
FIG. 5 is a view for explaining the replacement of a microporous filtration membrane in a membrane element of the present invention.
FIG. 6 is a view for explaining the replacement of a microporous filtration membrane in a conventional membrane element.
FIGS. 7 are cross sectional views of a fusion bonded portion of a membrane element of the present invention.
FIGS. 8 are cross sectional views of a fusion bonded portion of a conventional membrane element.
DESCRIPTION OF THE REFERENCE CODES
1 : Microporous filtration membrane
2 : Thermoplastic resin plate for filtration
3 : Hot plate
11 : Substrate
12 : Thermoplastic resin
21 : Positioning line
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now, the description will be made for the present invention based on its embodiment.
FIG. 1( a ) is a perspective view of a membrane element of the present invention. Specifically, as illustrated in this Figure, microporous filtration membranes 1 each having micro pores and nonwoven fabric made of synthetic resin fibers, which nonwoven fabric acting as a substrate, are respectively provided on front and rear sides of a thermoplastic resin plate for filtration 2 in tension between a positioning line 21 defined as an indicator in a peripheral part of the plate 2 . Both the front and rear sides of the peripheral part of the plate 2 each have a flat surface, and a center portion inside of the peripheral part forms filtrate flow passages enabling water to be treated to pass through the microporous filtration membranes 1 in a direction orthogonal to the membrane surface, thereby obtaining filtrate. The positioning line 21 is not necessarily provided but if it is provided, it is preferable to draw a line with a marker or the like. Both the front and rear sides of the peripheral part of the plate 2 each have a flat surface, but they may be provided with protrusions in the same manner as a filtration plate for fusing a microporous filtration membrane 1 by ultrasonic wave, the microporous filtration membranes 1 can be provided in tension by the following joining method, as long as the protrusion has a flat top. The microporous filtration membranes 1 each are made up by having nonwoven fabric made of synthetic resin fibers acting as a substrate 11 , and a thermoplastic resin 12 impregnated into this substrate 11 , thereby forming micro pores, as illustrated in a cross sectional view taken along a line A-A′ in FIG. 1( a ).
Providing each microporous filtration membrane 1 on the plate 2 in tension is achieved by joining the peripheral part of the plate 2 to the microporous filtration membrane without fusing the nonwoven fabric acting as the substrate 11 . Specifically, as illustrated in FIG. 2( a ), when pressed by a linear-shaped hot plate disposed along the positioning line 21 , the plate 2 is softened to have a recess, into which the microporous filtration membrane 1 is drawn, as represented by arrows. FIG. 2( b ) illustrates a state in which the linear-shaped hot plate 3 is located along the positioning line 21 , and FIG. 2( c ) illustrates a state in which the plate 2 is being pressed by the hot plate 3 via the microporous filtration membrane 1 . With this arrangement, the microporous filtration membrane can be provided in tension by the recess.
The arrangement as described above, in which the linear-shaped hot plate is disposed along the positioning line 21 and the microporous filtration membrane 1 is provided in tension by applying pressure by the hot plate, is employed for the reason that when a rectangular hot plate corresponding to the rectangular positioning line 21 is employed, the microporous filtration membrane 1 can be provided in tension on the plate 2 by one action, and the microporous filtration membrane 1 is drawn into the recess formed along the positioning line 21 and thus the tensioning effect can be enhanced. In order to further enhance the tensioning effect to prevent occurrence of creases on four corners, four corners of the rectangular hot plate are rounded and a recess having rounded corners at the four corners of the jointed portion of the microporous filtration membrane 1 and the thermoplastic resin plate for filtration 2 is formed. Contrarily to this, when ultrasonic wave is employed, a rectangular horn cannot be used and therefore the respective sides must be fusion bonded independently of each other through several actions. Thus, it does not make sense to provide rounded portions to the four corners of the protrusion for the ultrasonic fusion bonding, and it is not expectable to enhance the tensioning effect or prevent occurrence of creases on four corners. Accordingly, a large-sized membrane element having a short side of about 0.5 m and a long side of about 1 m, which may pose a problem on cost and performance of providing the microporous filtration membrane 1 in tension when it is manufactured by ultrasonic fusion bonding, can be manufactured so that a membrane element for use in a large scale wastewater treatment plant can be manufactured at low cost.
The aforesaid recess may have a depth of 50 to 500 μm (30 to 300% of the thickness of the nonwoven fabric) and a width of 0.5 to 25 mm, and preferably a depth of 100 to 300 μm and a width of 1.5 to 5 mm. In a case where the four corners are rounded, a curvature radius is 2 to 20 mm and preferably 3 to 10 mm. When the depth of the recess is larger than 500 μm, the nonwoven fabric may be deteriorated due to the mechanical stress caused when it is pressed into the recess. When the depth of the recess is smaller than 50 μm, there is a problem in that the nonwoven fabric cannot be satisfactorily pressed towards the thermoplastic resin plate for filtration 2 and therefore the fusion-bonding strength may not be secured. When the width of the recess is smaller than 0.5 mm, there is a problem in that the temperature of the hot plate during fusion bonding is lowered and therefore fusion bonding at an appropriate temperature is difficult to be made. When the width of the recess is larger than 25 mm, there is a problem in that a large displacement is caused by the pressing-in is caused and hence creases may be caused on the four corners of the microporous filtration membrane 1 . When a curvature radius is smaller than 2 mm, there is a problem in that creases are caused on the four corners of the microporous filtration membrane 1 . When the curvature radius is larger than 20 mm, there is a problem in that an effective membrane area of the microporous filtration membrane 1 is decreased although the occurrence of creasing can be prevented. The method of measuring the depth of the recess will be hereinafter described.
As an example of the microporous filtration membrane 1 , a Yumicron membrane manufactured by Yuasa Corporation, which has a number of micro pores with average pore size of 0.4 μm, can be used. The microporous filtration member 1 having such average pore size is called as a microfiltration membrane according to the definition of JIS K 3802. The aforesaid plate 2 as used is made of an acrylonitrile-butadiene-styrene copolymer (ABS) resin.
Polyethylene terephthalate acting as a substrate of the microporous filtration membrane has a fusing point of about 250° C., and when an ABS resin is used as a plate for filtration, the Vicat softening temperature is about 110 ° C. Therefore, as illustrated in FIG. 3 , when a linear-shaped hot plate corresponding in shape to the positioning line is located above the microporous filtration membrane and is pressed against the plate for filtration via the microporous filtration membrane while controlling the temperature of the linear-shaped hot plate to be equal to or lower than the fusing point of the nonwoven fabric acting as the substrate and equal to or higher than the Vicat softening temperature of the thermoplastic resin of the plate for filtration, the microporous filtration membrane and the plate for filtration are softened. Then, the substrate is pressed into the resin of the softened plate, thereby forming a recess, and then the application of pressure is stopped so that the microporous filtration membrane and the plate for filtration can be joined together. No detailed description will be made for the Vicat softening temperature of an ABS resin as a material of the plate for filtration, since its testing method is described in the JIS K 7206 (Testing method of the Vicat softening temperature of thermoplastic resin). Contrarily to this, according to the ultrasonic fusion bonding, as illustrated in FIG. 4 , an ultrasonic horn is activated on the protrusion of a plate for filtration via a microporous filtration membrane so that the microporous filtration membrane can be joined to the plate for filtration through the protrusion.
In a case where a microporous filtration membrane is fusion bonded to a plate for filtration by the linear-shaped hot plate, a recess is formed on nonwoven fabric as illustrated in a cross-sectional photograph of FIG. 7( a ). As being apparent from a bottom of the recess (an enlarged photograph of a B portion of FIG. 7( a ) illustrated in a cross-sectional photograph of FIG. 7( b )) and an edge of the recess (an enlarged photograph of a C portion of FIG. 7( a ) illustrated in the cross-sectional photograph of FIG. 7( c )), the cross-sectional shape of fibers of the nonwoven fabric is not changed although there is a difference as to whether the fibers of the nonwoven fabric have been thickened. Contrarily to this, in a case where nonwoven fabric acting as a substrate is fusion bonded to a plate for filtration by ultrasonic wave, as being apparent from a portion to be joined to a protrusion as illustrated in a cross-sectional photograph of FIG. 8( a ) (an enlarged photograph of a B portion of FIG. 8( a ) illustrated in a cross-sectional photograph of FIG. 8( b )) and a portion not to be joined to the protrusion (an enlarged photograph of a C portion of FIG. 8( a ) illustrated in a cross-sectional photograph of FIG. 8( c )), the cross-sectional view of fibers of the nonwoven fabric has been changed. It is assumed that the difference in cross-sectional shape of fibers of the nonwoven fabric is caused because the ultrasonic fusion bonding, which cannot control the temperature, causes deterioration of the nonwoven fabric due to heat, while the fusion bonding by the hot plate whose temperature is lower than the fusing temperature of the nonwoven fabric causes less deterioration of the nonwoven fabric due to heat. The depth of the recess in a case where the nonwoven fabric has been fusion bonded to the plate for filtration by the hot plate was measured as a distance between an upper surface of the bottom of the recess (an X portion in FIG. 7( a )) and an upper surface of the edge of the recess (a Y portion in FIG. 7( a )) upon observation of a cut plane by an electron microscope. It is to be noted that since the microporous filtration membranes 1 were placed upright on an adhesive tape when taking a cross-sectional photograph, holes opened through the adhesive tape are shown on the upper and lower sides of the nonwoven fabric, but the holes are not related to the present invention.
EXAMPLE 1
In joining a microporous filtration membrane to a plate for filtration of an ABS resin by using a linear-shaped hot plate having a width of 20 mm and a length of 500 mm, while the temperature of the hot plate was controlled to be equal to or lower than about 250° C. and equal to or higher than about 110° C., that is, to have a relation of: the fusing point of the nonwoven fabric acting as the substrate>the temperature of the hot plate≧the Vicat softening temperature of the thermoplastic resin plate for filtration, the temperature of the hot plate was controlled to 210° C., 180° C. and 150° C., respectively, and a pressure of 0.5 MPa was applied to the microporous filtration membrane for 10 seconds and then the microporous filtration membrane was joined to the plate for filtration. Then, an investigation was made by a tensile test to observe whether the microporous filtration membrane is peeled off from the plate for filtration. According to the test result, it has been found that, with a width of 20 mm and less than 15N, the microporous filtration membrane is not peeled off from the resin plate, and this is a value tolerable for practical use as a membrane element. From this, it is assumed that, when the temperature of the hot plate is controlled within the above range, a mixed resin of a thermoplastic resin of the plate for filtration and a resin of the microporous filtration membrane (mainly the resin of the plate) is generated in a joined portion, and recesses and protrusions of the surface of the nonwoven fabric of the substrate are pressed into the plate for filtration so that the strength of the joined portion can be secured without decreasing of the strength of the substrate. Upon measuring the tensile strength according to JIS L 1913 (general short fiber nonwoven fabric testing method) in the aforesaid tensile test, it has been found that a product of the present invention made by fusion bonding by using the hot plate has a strength about 30% higher than a conventional product made by ultrasonic fusion bonding.
EXAMPLE 2
In Example 1, in which the temperature of the hot plate is set to be equal to or lower than about 250° C., which is the fusing point of the nonwoven fabric, the microporous filtration membrane and the plate for filtration are subjected to thermal stress and mechanical stress in the recess formed by the application of pressure by the hot plate. An influence on deterioration of the substrate by thermal stress is suppressed by controlling the temperature of the hot plate to the aforesaid temperature, but no consideration is taken to the deterioration of the substrate due to the mechanical stress. Therefore, in Example 2, in order to suppress the deterioration of the substrate due to the mechanical stress, a test specimen of the same material as that of the substrate is subjected to JIS K 7191-2 (Plastic- Deflection Temperature Under Load Test-Section 2: Plastic and Ebonite) to determine the deflection temperature under load so that the temperature of the hot plate is controlled to be equal to or lower than the deflection temperature under load. Specifically, the testing was conducted according to the B method specified by the JIS for a test specimen manufactured from the aforesaid polyethylene terephthalate, and it was found that the deflection temperature under load was about 195° C. In view of this deflection temperature under load, the temperature of the hot plate is set to be equal to or lower than about 250° C., which is the fusing point of the nonwoven fabric of polyethylene terephthalate acting as the substrate, and preferably equal to or lower than about 195° C.
Now, the description will be made for the case in which a microporous filtration membrane of the thus manufactured membrane element is to be replaced. In the present invention, as illustrated in FIG. 5 , even if the used microporous filtration membrane is removed from the plate for filtration, the joined surface remains flat and therefore a positioning line is provided in a position different from the peeled-off position. The hot plate is placed on this positioning line to join a new microporous filtration membrane so that the membrane element can be reused by the replacement of the microporous filtration membrane. Contrarily to this, according to the ultrasonic fusion bonding, as illustrated in FIG. 6 , when the used microporous filtration membrane is peeled off from the plate, a deformed protrusion is left on the peeled-off position, which necessitates to reshape this protrusion to enable the ultrasonic fusion bonding for reuse (in a case where the fusion bonding is made by using the hot plate with the aforesaid protrusion acting as the positioning line, the protrusion is to be removed to have a flat surface before the replacement of the microporous filtration membrane). This is not preferable from view point of the cost for reuse, and is still not preferable from the view point of the waste treatment and cost even in a case where the membrane element is discarded and replaced with a new one.
As described above, in comparison between the present invention and the ultrasonic fusion bonding conventionally performed, both commonly perform thermal fusion bonding, but the present invention produces advantages which may not be achieved by the ultrasonic fusion bonding, in which the microporous filtration membrane can be joined to the plate while keeping the microporous filtration membrane in tensed state, providing the microporous filtration membrane in tension can be made by one action, and the microporous filtration membrane can be replaced with a new one.
In the aforesaid Examples, nonwoven fabric of polyethylene terephthalate is used for the substrate, but nonwoven fabric of synthetic fibers of such as other polyester or polypropylene. When polypropylene, which has a fusing point of 170° C., is used, the temperature of the hot plate is set to be equal to or lower than 170° C. and preferably equal to or lower than 130° C., which is its deflection temperature under load. Although an ABS resin is used for the plate for filtration, a polyvinylchloride or polyethylene plate may be used. When polyvinylchloride is used, the temperature of the hot plate is better to be set to be equal to or higher than 80° C., which is its Vicat softening temperature. When polyester is used and it is, for example, high density polyethylene, the temperature of the hot plate is better to be set to be equal to or higher than 100° C., which is its fusing point. In either case, the temperature of the hot plate is controlled to be equal to or lower than the fusing point of nonwoven fabric acting as the substrate (or when the material is such as an amorphous material having no fusing point, the Vicat softening temperature is employed, and accordingly the temperature of the hot plate is set to be equal to or lower than the Vicat softening temperature) and equal to or higher than the Vicat softening temperature of a thermoplastic resin plate for filtration (when the material has a fusing point, the temperature of the hot plate is set to be equal to or lower than the fusing point).
INDUSTRIAL APPLICABILITY
As described above, the present invention has high industrial applicability since it has a feature enabling the reuse of the membrane element and the like. | A membrane element in which, after membrane breakage or deterioration, the filtration plate made of a thermoplastic resin can be reused to replace the membrane with a fresh one. The membrane element comprises a filtration plate made of a thermoplastic resin and, bonded to a peripheral smooth surface thereof, a microporous filter membrane which has fine pores formed therein and employs a nonwoven fabric comprising synthetic resin fibers as a support. A hot plate having a shape corresponding to the peripheral shape of the resinous filtration plate is brought into contact with a peripheral smooth surface of the plate so as to form a recessed part in the surface. The temperature of the hot plate is regulated so as to be not higher than the melting point of the nonwoven fabric serving as the support and not lower than the Vicat softening temperature of the filtration plate made of a thermoplastic resin. The thermoplastic-resin filtration plate is pressed with this hot plate through the microporous filter membrane to bond it to the membrane. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Application Ser. No. 61/245,822 “Exhaust Process and Heat Recovery System” by James W. Birmingham and Kevin J. O'Boyle filed Sep. 25, 2009 and incorporates the material of the priority application to the extent that it does not contradict the present application.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to an exhaust processing and heat recovery (EPHR) system and method for use with fossil fuel fired furnaces. More particularly, the present invention relates to an EPHR system in which alkaline particles are introduced into a flue gas stream to allow additional heat extraction and reduce fouling of air preheater equipment.
[0004] 2. Discussion of Related Prior Art
[0005] Many power generation systems are powered by steam that is generated via furnaces fired by fossil fuels, such as, for example, coal or oil. A typical power generation system is generally depicted in the diagram shown in FIG. 1A .
[0006] FIG. 1A shows a power generation system 10 that includes a steam generation system 25 and an exhaust processing and heat recovery system (EPHRS) 15 and an exhaust stack 90 . The steam generation system 25 includes a furnace 26 . The EPHRS 15 may include a regenerative air preheater 50 , a particulate removal system 70 and a scrubber system 80 . A forced draft (FD) fan 60 is provided to introduce air into the cold side of the air preheater 50 via inlet 51 . The particulate removal system 70 may include, for example, an electrostatic precipitator (ESP), and/or a fabric filter system (Bag House), or the like. Scrubber system 80 may include, for example, a wet or dry flue gas desulphurization (WFGD/DFGD) systems.
[0007] The regenerative air preheater 50 helps increase the thermal efficiency of furnace 26 , thereby reducing its operating costs and emissions of greenhouse gases. An air preheater 50 is a device designed to heat air before it is introduced to another process such as, for example, the combustion chamber of a furnace 26 . There are different types of regenerative air preheaters, including those that include moving or rotating heat exchange elements, such as, for example, the Ljungstrom® air preheater. Other regenerative air preheaters utilize fixed heat exchange elements and/or internally rotating hoods or ductwork that is fixed to rigid air and/or gas ducts.
[0008] FIG. 1B and FIG. 1C are diagrams generally depicting a conventional rotary regenerative preheater 50 . The typical air preheater 50 has a rotor 512 rotatably mounted in a housing 524 . The rotor 512 is formed of diaphragms or partitions 516 extending radially from a rotor post 518 to the outer periphery of the rotor 512 .
[0009] The partitions 516 define compartments 520 there between. These partitions 516 contain heat exchange element basket assemblies 522 . Each basket assembly 522 includes one or more specially formed sheets of heat transfer surfaces that are also referred to as heat exchange elements 542 . The surface area of the heat exchange elements 542 is significant, typically on the order of several thousand square feet.
[0010] In a typical rotary regenerative air preheater 50 , the flue gas stream, FG 1 and the combustion air stream, A 1 , enter the rotor 512 from opposite ends/sides of the air preheater 50 and pass in opposite directions over heat exchange elements 542 that are housed within the basket assemblies 522 . Consequently, the cold air inlet 51 and the cooled flue gas outlet 54 are at one end of the air preheater 50 (generally referred to as the cold end 544 ) and the hot flue gas inlet 53 and the heated air outlet 52 are at the opposite end of the air preheater 50 (generally referred to as the hot end 546 ). Sector plates 536 extend across the housing 524 adjacent the upper and lower faces of the rotor 512 . The sector plates 536 divide the air preheater 50 into an air sector 538 and a flue gas sector 540 .
[0011] The arrows shown in FIG. 1B and FIG. 1C indicate the direction of the flue gas stream FG 1 /FG 2 and the air stream A 1 /A 2 through the rotor 512 . The flue gas stream FG 1 entering through the flue gas inlet 53 transfers heat to the heat exchange elements 542 in the basket assemblies 522 mounted in the compartments 520 positioned in the flue gas sector 540 . The heated basket assemblies 522 are then rotated to the air sector 538 of the air preheater 50 . The stored heat of the basket assembly 522 is then transferred to the air stream A 1 entering through the air inlet 51 . The cold flue gas FG 2 stream exits the preheater 50 through the flue gas outlet 54 and the heated air stream A 2 exits the preheater 50 through the air outlet 52 .
[0012] Referring back to FIG. 1A , air preheater 50 heats the air introduced via FD fan 60 . Flue gas (FG 1 ) emitted from the combustion chamber of the furnace 26 is received by the air preheater via inlet 53 . Heat is recovered from the flue gas (FG 1 ) and is transferred to input air (A 1 ). Heated air (A 2 ) is fed into the combustion chamber of the furnace 26 to increase the thermal efficiency of the furnace 26 .
[0013] During the combustion process in furnace 26 , sulfur in the fuel used to fire the furnace 26 is oxidized to sulfur dioxide (SO 2 ). After the combustion process, some amount of SO 2 is further oxidized to sulfur trioxide (SO 3 ), with typical amounts on the order of 1% to 2% going to SO 3 . The SO 2 and SO 3 will be passed from the combustion chamber of the furnace 26 and into the exhaust flue as part of the flue gas FG 1 that is then emitted from the steam generating system 25 and received by the inlet 53 of air preheater 50 . The presence of iron oxide, vanadium and other metals at the proper temperature range allows this oxidation to take place. Selective catalytic reduction (SCR) is also widely known to oxidize a portion of the SO 2 in the flue gas FG 1 to SO 3 .
[0014] As heat is being recovered/extracted by the air preheater from the flue gas FG 1 , the temperature of the flue gas FG 1 is reduced. It is desirable to remove the maximum amount of heat from the flue gas and transfer it to the heated air going to the furnace or the fuel pulverizer mills to optimize the thermal efficiency of the power plant. Additional heat extraction allows for the design/use of particulate collection equipment, gaseous cleanup equipment, ducting and stacks downstream of the flue gas outlet that are rated for lower temperature ranges and reduced volumetric flow rates. The lower temperature rating and lower flow rate mean that tremendous cost savings can be realized by not having to provide equipment capable of withstanding higher temperatures and higher flow rates. However, the lower flue gas temperature range may result in excessive condensation of sulfur trioxide (SO 3 ) or sulfuric acid vapor (H 2 SO 4 ) that may be present in the flue gas. As a result, sulfuric acid may accumulate on surfaces of the heat exchange elements 522 of the air preheater 50 . Fly ash in the flue gas stream can be collected by the condensed acid that is present on the heat transfer surfaces. This acid causes fly ash to stick more tightly to surfaces. This “fouling” process impedes the air and flue gas flow thru the air preheater, resulting in increased pressure drop through the air preheater plus lower heat transfer effectiveness.
[0015] After a period of time, accumulations of acid and flyash on surfaces of the air preheater 50 grow so large that they must be removed in order to maintain the thermal performance and an acceptable pressure drop the air preheater. This is typically accomplished by periodically (for example, 3 times daily) “sootblowing” the heat transfer surface with compressed air or steam to remove the deposits that have accumulated on the heat transfer surface while the air preheater is operating. In addition, if required, washing the air preheater with water may be conducted during an outage of the steam generation system 25 when the furnace 26 is shut down and maintenance operations are performed.
[0016] A potential benefit to reducing the flue gas outlet temperature is that the particulate removal system 70 and scrubbing equipment 80 may be designed for a lower operating temperature. The lower temperature flue gas also has a lower volumetric flow rate. The reduction in flue gas temperature, volume and acidity reduce operating and capital costs that are associated with equipment designed for the higher volumetric flow rates, higher operating temperatures, or higher SO 3 /H 2 SO 4 concentrations in the flue gas. These conditions would exist if the acid were not condensed and/or neutralized to prevent excessive fouling of the heat transfer surfaces. Once the flue gas exhaust has passed through particulate removal and scrubbing operations, it is then ready for introduction to the exhaust stack 90 for elevation and dispersion over a wide geographic area.
[0017] Extraction of heat from flue gases is beneficial and is used for performing various operations in a typical plant. However, in existing coal and/or oil fired steam generation systems, it is costly to remove additional heat from the exhaust gas stream. Excessive reduction of the flue gas temperature without consideration for the additional condensation of H 2 SO 4 vapors in the flue gas, will result in excessive fouling of the heat transfer surfaces in the air preheater. Thus, a need exists in the industry to address the aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
[0018] The invention may be embodied as a method of extracting heat from a flue gas stream FG 1 having acidic material and flue gas particulates using an air preheater 250 having a flue gas inlet 253 , flue gas outlet 254 and a plurality of heat exchange surfaces 542 , comprising the steps of:
[0019] receiving a flue gas stream FG 1 into the flue gas inlet 253 of the air preheater 250 ;
[0020] calculating a mass flow rate of acid material passing in the flue gases FG 1 ;
[0021] calculating a mass flow rate of alkaline particles 275 to be injected into the flue gas stream FG 1 to neutralize the acidic material;
[0022] injecting alkaline particles 275 with a distribution of particles sizes at the calculated mass rate into the flue gas stream upstream of the air preheater 250 ;
[0023] calculating a degree of accumulation of particulates;
[0024] based upon the degree of accumulation of particulates, adjusting at least one of a size distribution of the alkaline particles 275 being injected into the flue gases, and the mass flow rate at which the alkaline particles 275 are injected into the flue gases;
[0025] thereby reducing accumulation of flue gas particulates on the heat exchange elements 542 , plus reducing fouling within the air preheater, and thereby increasing the thermal efficiency of the air preheater 250 .
[0026] The degree of fouling may be calculated by measuring a pressure drop across the air preheater 250 from the flue gas inlet 253 to the flue gas outlet 254 and comparing the measured pressure drop to at least one predetermined threshold.
[0027] When using a rotary air preheater having a rotor that is rotated by an motor powered by electric current I of varying voltage V, the degree of fouling may be calculated by measuring the voltage V and electric current I, and comparing the measured current at the measured voltage to a predetermined current for the same voltage to determine a current difference. The current I difference is compared to prestored conversion information to determine a degree of fouling.
[0028] The present invention may also be embodied as a method of reducing fouling of an air preheater 250 used in recovering heat from a furnace 26 that creates flue gases with acidic materials and flue gas particulates, comprising the steps of:
[0029] providing an air preheater 250 coupled to said furnace 26 to receive said flue gases FG 1 at a flue gas inlet 253 , pass them over a plurality of heat exchange plates 542 and exhaust said flue gases out of a flue gas outlet 543 ;
[0030] sensing or calculating a mass flow rate of acidic material in said flue gases;
[0031] calculating a mass flow rate of alkaline particles required to adequately neutralize the acidic materials in the flue gases;
[0032] injecting the alkaline particles 275 at the calculated mass flow rate into flue gases entering the air preheater 250 ;
[0033] sensing a pressure drop from the flue gas inlet 253 to the flue gas outlet 254 of the air preheater 250 ;
[0034] increasing the mass rate of alkaline particles 275 injected into the flue gases when the sensed pressure drop is greater than a predetermined threshold, and
[0035] decreasing the mass rate of alkaline particles 275 injected into the flue gases when the sensed pressure drop is lower than a predetermined threshold; and
[0036] repeating the steps above during operation of the furnace 26 to reduce fouling of the air preheater 250 allowing it to more efficiently extract heat. Additional heat, beyond the levels that are achieved with current air preheater design technologies, can be extracted from the flue gas as a result of reducing the gas outlet temperature of the heat exchanger without excessive fouling or corrosion activities within the air preheater that would exist if the SO 3 /H 2 SO 4 were not condensed and neutralized by the alkaline material injected into the flue gas stream upstream of the air preheater.
[0037] The present invention may also be embodied as an exhaust processing and heat recovery (EPHR) system 215 for more efficiently recovering heat from a furnace 26 producing heated flue gases FG 1 having acid vapors and entrained flue gas particulates comprising:
[0038] an air preheater 250 coupled to said furnace 26 , the air preheater 250 having:
[0039] an flue gas inlet 253 adapted to receive said flue gases FG 1 ,
[0040] a plurality of heat exchange plates 522 for extracting heat from the flue gases; and
[0041] a flue gas outlet 254 for exhausting the flue gas stream FG 2 after it has passed over the heat exchange plates 522 ;
[0042] flue gas sensors 310 to monitor physical and chemical conditions within the flue gases;
[0043] pressure drop sensors 301 , 303 adapted to measure the drop in pressure from the air preheater inlet 253 to the air preheater outlet 254 ;
[0044] an alkaline injection system 276 responsive to control signals from another device, for introducing alkaline particles 275 into a flue gas stream FG 1 upstream of an air preheater 250 when actuated; and
[0045] a PLC controller 305 adapted to calculate a mass flow rate of alkaline particles 275 based upon the sensed flue gas conditions; and adapted to control the alkaline injection system 276 to inject the calculated mass flow rate of alkaline particles 275 to neutralize the acidic materials in the flue gases.
[0046] The present invention may also be embodied as an efficient, low cost furnace system having:
[0047] a. a fossil fuel furnace that produces heated flue gases;
[0048] b. an air preheater coupled to the furnace, adapted to receive the heated flue gases, neutralize acids in the heated flue gases, extract heated combustion air for the furnace, extract additional heated air to be used elsewhere in the system, reduce flue gas temperature below a flue gas acid dew point, reduce the volume of flue gases exiting the preheater; and
[0049] c. flue gas processing equipment coupled to, and downsteam of the air preheater that are more compact and less costly than those used on systems that do not have air preheaters that neutralize flue gas acids.
[0050] Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
[0052] FIG. 1A is a diagram depicting a typical steam generation system and associated exhaust processing equipment.
[0053] FIG. 1B is a diagram depicting a perspective view, partially broken away, of a conventional rotary regenerative air preheater.
[0054] FIG. 1C is a schematic diagram depicting a further perspective view of the conventional rotary regenerative air preheater of FIG. 1B .
[0055] FIG. 2A is a diagram generally depicting one embodiment of an exhaust processing and heat recovery system in accordance with the invention.
[0056] FIG. 2B is a diagram generally depicting a further embodiment of an exhaust processing and heat recovery system in accordance with the invention.
[0057] FIG. 3 is a schematic diagram depicting an embodiment of an air preheater having an auxiliary air inlet.
DESCRIPTION OF THE INVENTION
[0058] The purpose of this invention is to provide a means to extract more heat from the flue gas as it passes through the gas side of the regenerative air heater without the heat transfer surfaces of the equipment downstream of the regenerative air preheater becoming excessively fouled or corroded.
[0059] The present invention is directed to control the amount of acid that is condensed and accumulated on heat transfer elements of an air preheater and to thereby improve the effectiveness of the air preheater in extracting heat from a flue gas stream FG 1 from the combustion chamber of, for example, a furnace. A further aspect of the invention is directed to controlling the “wetness” of the deposit on the heat transfer surfaces so that the deposit can be maintained in a condition that allows it (the deposit) to be easily removed while the air preheater is in operation. A further aspect of the proposed invention is directed to an air preheater that is configured to allow for the distribution of additional heat extracted from the flue gas stream FG 1 due to the increased efficiency of the air preheater in extracting heat from the flue gas stream.
[0060] Reduction of the SO 3 concentration entering the air heater, plus an additional means to extract heat from the flue gas as it passes through the air preheater will have several benefits: (1) the volumetric flue gas flow leaving the air heater will be lower, (2) the preheat temperatures of the air side flows (generally called primary and secondary air) can be increased, and (3) Additional energy in the form of preheated air can be made available for use elsewhere in the plant. Potential uses of this additional energy are: preheating boiler feedwater, drying pulverized coal, conveying the pulverized coal to the burners, supplying energy to post-combustion CO 2 capture systems, reheating stack gas to reduce visible water vapor plume or for other uses where heat is needed within a power plant.
[0061] FIG. 2A and FIG. 2B are diagrams generally depicting embodiments of an exhaust processing and heat recovery system 215 in accordance with the proposed invention. FIG. 2A is a diagram depicting one embodiment of an EPRS 215 that is includes an alkaline injection system 276 to interactively introduce a sorbent of alkaline particles 275 into the flue gas stream FG 1 prior to FG 1 being received by the air preheater 250 via inlet 253 . Alkaline injection system 276 has the ability to selectively introduce various size distributions of alkaline particles 275 in the sorbent.
[0062] In this embodiment, the EPRS 215 includes a regenerative air preheater 250 , a particulate removal system 70 and a scrubber system 80 . An FD fan 60 is provided to introduce an air stream A 1 into the cold side of the air preheater 250 via inlet 251 . The particulate removal system 70 may include, for example, an electrostatic precipitator (ESP), and/or a fabric filter system (bag house), or the like. Scrubber system 80 may include, for example, a wet or dry flue gas desulphurization (WFGD/DFGD) system.
[0063] During operation of the EPRS 215 , sulfur trioxide (SO 3 ) and water vapor (H2O) in the flue gas FG 1 can combine to form an acid vapor in the operating temperature range of the flue gas upstream of the air preheater 250 . Once the flue gas containing this acid vapor reaches the air preheater 250 it will come in contact with, condense and accumulate on, various surfaces in the air preheater 250 , including heat transfer elements ( 542 of FIG. 1B ) when it is cooled below its acid dew point temperature. This accumulation of condensed acid will “foul” the air preheater operation by collecting and retaining flyash particles on the surface of the heat transfer surface, thus impeding the flow of flue gas FG 1 through the air preheater 250 . This results in an excessive pressure drop through the air preheater and overall drop in effective transfer of heat from the flue gas stream FG 1 to the input air stream A 1 .
[0064] The acid vapor and condensed acid may be referred to collectively as ‘acidic material’.
[0065] One embodiment of the present invention employs flue gas sensors 310 that monitor physical and chemical parameters of the flue gas. Depending upon their use they may be located at the inlet or outlet, or other location within the air preheater 250 .
[0066] A programmable logic controller (“PLC controller”) 305 reads the sensor information and determines a proper mass flow rate to neutralize the acidic material in the flue gases. This mass flow rate may also be determined by calculation from air and fuel firing conditions that are transmitted from the furnace by various methods of data communication in use in fossil fuel fired furnaces. It may also control an alkaline injection system 276 causing it to inject the calculated mass flow rate of correctly sized alkaline material into the flue gases upstream of the flue gas inlet 253 .
[0067] Alkaline particles 275 , such as powdered limestone or other alkaline materials are introduced as a sorbent into the flue gas stream FG 1 upstream of the air preheater 51 (i.e. before the flue gas stream FG 1 reaches the air preheater 50 ). These particles serve as condensation sites within the flue gas stream FG 1 for the acid vapors, and then function to neutralize the condensed acid. Both the condensation and neutralization of the acid occurs inside the air preheater when the flue gas is cooled to a temperature that will initiate condensation of the acid vapor. Introducing an adequate mass quantity, for example, 1% to 25% mass ratio of alkaline particles to flyash concentration into the flue gas stream FG 1 as it passes through the air preheater 250 causes most of the acid to neutralize. However, introducing alkaline material into the flue gas stream strictly on a stoichiometry basis does not result in the most effective control of fouling caused by the build-up of acid within the air preheater 250 . In order to more effectively control the creation and build up of acid within the air preheater, it is proposed that the alkaline particles that are introduced into the flue gas stream FG 1 have a varying range of sizes (diameters).
[0068] By measuring the temperature gradient of the flue gas as it passes thru the heat transfer surfaces within the air preheater, and controlling the mass quantity, and size distribution of the alkaline particles that are introduced into the flue gas stream FG 1 , it is possible to control the extent to which acid condenses and remains on the heat transfer surface and in the flue gas as the flue gas passes through the air preheater 250 .
[0069] The size of fly ash particles, produced from the typical combustion of coal, varies from below 0.01 microns to over 100 microns. The smaller diameter particles of fly ash or other particulate material in the flue gas stream FG 1 , generally less than 5 microns in diameter, tend to provide a good nucleus for condensation and potential neutralization of H2SO 4 vapor that may exist in the flue gas stream FG 1 .
[0070] If the condensation results in a deposit on the heat transfer surface that cannot be removed by cleaning methods employed while the air preheater is in operation, the deposit will accumulate to the point where the normal operation of the air preheater cannot be maintained. However, when the condensation process is combined with the neutralization process that can occur when an adequate mass quantity of alkaline materials of the proper particle size distribution are injected into the flue gas stream, successful operation of the air heater can be maintained. The neutralization process will result in the reduction in the amount of acid that remains on the heat transfer surface and embedded in the particulate deposits within the air preheater.
[0071] An important factor in the effectiveness of the control of fouling within the air preheater is the location where the flue gas particulates and alkaline particles in the flue gas contact the various heat transfer surfaces of the air preheater exchange elements ( 542 of FIG. 1B ), as well as the size of these particles. Smaller particles have a greater tendency to follow the flue gas flow and a lesser tendency to strike the surface of heat exchange elements. Large particles, generally greater than 15 microns, have more momentum and a greater tendency to impact the surface of the heat exchange elements. Large particles also have a greater tendency to fall off (without accumulating thereon) the surfaces of the heat exchange elements if there is little or no acid present on the surface of the particle or on the surface of the heat exchange elements. The large particles can also act to “scrub”, or erode, small particles from the air preheater surfaces, such as the heat transfer elements if the small particles are not strongly bonded to the surface.
[0072] Injection of alkaline particles downstream of the air preheater is typically done to control SO 3 plume emissions and to enhance mercury removal by the bag house or precipitator. However, this does not impact the fouling of the air preheater.
[0073] In the present invention, the alkaline particles are injected into the ductwork upstream of the gas inlet to the air preheater. They must be distributed via the injection system to insure that there is an adequate supply of the alkaline material is evenly dispersed throughout the cross-section of the ductwork to insure the condensation and neutralization processes can occur once the flue gas stream enters the air preheater and is cooled to its dew point temperature or comes in contact with the heat transfer surfaces within the air heater that are below the acid dew point temperature.
[0074] When flue gases containing sulfur trioxide and water vapor are at a temperature that is below the acid dew point, sulfuric acid condensates to a liquid. Condensation will occur on surfaces within the air preheater having temperatures that are below the local dew point temperature, and upon further cooling, it may also occur within the gas stream itself.
[0075] When the gas stream reaches a supersaturated state, sulfuric acid may condense by self-nucleation in the absence of entrained particulates. This generally occurs when the flue gas temperature is below the local acid dew point. If the gas stream contains entrained particles, these particles act as nucleation sites, and condensation occurs at temperatures closer to the local dew point.
[0076] In general, and when present, the small particles are the first to produce condensate when it appears within the gas stream. This is due to the fact that small particles have higher surface area to volume ratios, and this allows them to more closely follow flue gas temperature during cooling. Large particles have lower ratios that cause them to retain more heat, and upon cooling, they remain warmer than the surrounding flue gas. Therefore, in order to preferentially condense and chemically neutralize acid on an injected alkaline particle—as opposed to condensing on native flyash with little neutralizing capacity due to its composition, the size of the particle should be small compared to the majority of the native fly ash particles.
[0077] As previously stated, acid condensation begins on heat transfer surfaces with temperatures at or below the acid dew point. In order to adequately consume this acid to a level that results in a deposit on the heat transfer surfaces that can be removed by sootblowing or water washing, the alkaline particles must be deposited on the acid-wetted heat transfer surfaces at a suitable rate that adequately neutralizes the acid in the flyash. Thus, at this location the role of the alkaline particle has little in common with that of an optimum nucleation site, and its size requirements are different.
[0078] The physical momentum of the gas-entrained particles is the means by which the majority of the particles reach the surfaces of the heat transfer elements within the air preheater. Assuming that all particles have the same density, and travel through the air preheater with a velocity equal to that of the surrounding flue gas, small particles have a lesser momentum due to their lower mass. Therefore, given equal quantities entrained in flue gas, small particles will have a lesser deposition rate on the heat transfer surfaces. If greater deposition rates are required to consume acid condensed on the heat transfer surface, a large alkaline particle size may be preferable compared to increasing the quantity of small alkaline particles in the gas stream.
[0079] Optimum injection rates for alkaline particles may be achieved when the size distribution of the particles accounts for the two different purposes presented above. This size distribution is likely to be bimodal including ranges of both small and large particle sizes.
[0080] It is possible to further locate where within the air preheater acid will condense.
[0081] It is also possible to calculate and alter the alkaline particle distribution to ‘target’ locations with the air preheater to deposit the alkaline particles.
[0082] As flue gas passes through the air preheater, it cools. This causes a temperature gradient to be created. Knowing the inlet temperature and the outlet temperature, one can estimate the gradient across the air preheater.
[0083] As flue gas passes through the air preheater, it loses flow velocity. Again, this velocity gradient may be estimated knowing the inlet velocity and the outlet velocity.
[0084] The alkaline particles are subject to the force of the flowing flue gases. The flue gas force exerted on a particle depends upon the flue gas velocity, the particle's wind resistance and the weight of the particle.
[0085] The particles also have momentum due to their motion. The momentum of the particle is based upon the particle's velocity and mass.
[0086] When the flue gas force is not great enough to change the momentum of the particle directing it away from a surface, the particle impacts the surface. If the surface has condensed acid, the particle is very likely to stick to the surface. If the particle is an alkaline particle, it neutralizes some of the condensed acid.
[0087] Smaller particles have high surface area/mass ratio, and therefore a large wind resistance per unit mass. Larger particles have a smaller surface area to mass ratio, and have less wind resistance per unit mass and are less affected by the flue gas force.
[0088] For the same velocity, particles with greater mass have a larger momentum.
[0089] Assuming the same density for all particles, larger particles have larger mass.
[0090] As particles travel through the air preheater, they lose velocity. If the flue gas forces become weak enough (due to the lower velocity) so that they cannot alter the momentum of the particle away from a surface, the particles impact surfaces within the air preheater.
[0091] The distance that the particles travel through the air preheater before impacting a surface is dependent upon the particle size. Very small particles may be carried with the flue gas out of the preheater without impacting a surface at all. Therefore, the particle size is indicative of the location that a particle will be deposited and particle size distribution indicates how many particles will be deposited at various locations within the air preheater. If the particle size distribution is continuous in a proper size range, then the particles will blanket a contiguous region within the air preheater. Therefore, if one determines the location where the acids will condense, the particle size distribution may be chosen to deposit the majority of particles in the locations where acid is expected to condense.
[0092] The mass quantity of alkaline material, as well as the particle size distribution of the alkaline material, are factors in controlling the degree of fouling within the air preheater. The overall quantity of alkaline material introduced into the flue gas stream FG 1 must be adequate, however the particle size distribution must also be provided so that the alkaline particles actually contact the heat transfer surface locations within the air preheater at points where the acid condensation/accumulation tends to occur. As the acid in the flue gas stream FG 1 is neutralized and consumed, the accumulations become less sticky and can be more easily removed with soot blowing and/or water washing technologies. Without condensed acid present in the flue gas stream FG 1 , or on the heat transfer surface, particles, such as fly ash, do not form a deposit with strong adhesion properties on the surface of the heat exchange elements and thus, will not accumulate on the heat exchange elements to the thickness that will impede the flow of flue gas FG 1 thru the air preheater. The less that the flow of flue gas FG 1 thru the air preheater is impeded, the more heat the air preheater can extract from the flue gas stream FG 1 .
[0093] In one embodiment of the proposed invention, alkaline particles are introduced into the flue gas stream FG 1 have a bi-modal particle size distribution. These alkaline particles include “small” particles and “large” particles. The small particles are preferably sized to be within a range of 1 micron-15 microns in diameter, while the large particles are sized to be within a range of 15 microns to 150 microns. In general, all particles introduced into the flue gas stream FG 1 will be within a size range of 1 microns to 250 microns in diameter. The mass quantity of alkaline material required to be injected into FG 1 is a function of the SO 3 /H 2 SO 4 concentration in FG 1 , the flue gas flow rate, the mass quantity of flyash in FG 1 , and the chemical composition of the flyash in FG 1 . In general, the higher the concentration of SO 3 /H 2 SO 4 in FG 1 , the higher the mass quantity of alkaline material that must be injected. Flyash with a higher alkaline content will generally require less injection of alkaline material into FG 1 because the native alkalinity of the fly ash will aid the neutralization and consumption of H 2 SO 4 in the flue gas stream. The alkaline particles are preferably introduced into the flue gas stream FG 1 before the flue gas stream FG 1 reaches the air preheater. Flue gas sensors 310 may include a flue gas flow rate sensor, a particulate concentration sensor, and/or a sampling sensor, for measuring the alkalinity of the flue gas particulates.
[0094] These particles may be introduced into the flue gas stream FG 1 via, for example, as a dry material or as a liquid slurry that is injected via a distribution system, such as, for example, spray nozzles or injection devices (injectors) for introducing the particles into the flue gas stream FG 1 . The distribution system may be installed in the gas inlet ductwork leading to the air preheater. The distribution system is preferably configured to result in a uniform and adequate distribution of alkaline material across the flue gas stream FG 1 as it enters the air preheater. Alkaline distribution system 276 may employ compressed air to be utilized as a transport medium for the dry injection, or water supplied via a pump(s) could be used as the transport medium for the wet injection. Dry injection is the preferred method of introducing the alkaline particles into FG 1 , but a wet system designed to provide adequate dwell time in FG 1 for the evaporation of the water and drying of the alkaline particles is also a suitable method.
[0095] The mass quantity per unit time of alkaline sorbent injected can be controlled by monitoring several operating parameters associated with the air preheater and plant operation. This information can be collected from the overall plant control system, or obtained by the installation of specific data collection instrumentation. This input is provided to a PLC controller 305 controlling an alkaline injection system 276 . The quantity of sorbent to be injected will be a function of the mass flow rate and temperature of the flue gas entering the air heater, plus the concentration of the SO 3 and water vapor in the flue gas entering the air heater. The content of SO 3 in the flue gas entering the air preheater could be calculated from the sulfur content of the fuel, air/fuel ratio in the furnace, plus the temperature of the flue gas leaving the furnace and catalyst system installed upstream of the air preheater. The content of SO 3 in the flue gas can be calculated from the combustion efficiency characteristics of the fuel firing system. Most of these parameters may be read from an industrial system controller (not shown) that is used to operate the furnace 26 , directly measured in the flue gas stream by flue gas sensors 310 , or measured by means of wet chemistry or other suitable instrumentation that is commercially available. As a general rule, the lower the temperature of the flue gas leaving the air preheater, the lower the temperature of the heat transfer surfaces within the air preheater. Therefore, the amount of acid condensed and accumulated on the heat transfer surfaces will increase as the gas outlet temperature is decreased. As a result, lower gas outlet temperature or lower heat transfer surface temperature operation will require a higher rate of sorbent mass flow injection to prevent excessive fouling of the air preheater with a deposit that is too “wet” to be removed.
[0096] An added benefit of the large alkaline particles may be their natural tendency to aid in the “scrubbing” of deposits present on the heat transfer surfaces. Once again, the particle size that produces the scrubbing affect will have little in common with the size of an optimum nucleation site, and may not have the same size as a particle destined to consume acid condensed on the heat transfer surface.
[0097] The above parameters are measured and fed as inputs to the PLC controller 305 . The PLC controller 305 can be used to control the particle size distribution and/or the amount of alkaline sorbent injected into the air preheater over the entire operating range. For example, as the mass flow of flue gas entering the air preheater 250 is reduced, the PLC controller 305 will recalculate the quantity of sorbent required as a result of this change while also factoring in the current status of the other parameters being measured to complete the calculation of the required quantity of sorbent mass flow and its associated particle size distribution, and send a signal to the alkaline injection system to adjust the quantity of sorbent injected or the distribution of the particle sizes. If the sulfur content of the fuel is reduced (or increased), this input would be fed to the PLC controller 305 , and in combination of knowing the current status of the other parameters noted above, the quantity and sizing of sorbent to be injected would be adjusted.
[0098] The flue gas sensors 310 may include a flow rate sensor to determine the rate the flue gas is flowing through the preheater 250 , a particulate concentration sensor for measuring flue gas particulates, temperature sensors, and optionally sampling sensors to determine chemical properties of the flue gas particulates. PLC controller 305 reads information from these sensors to interactively calculate the proper mass flow rate of the alkaline particles 275 to be injected by alkaline injection system 276 .
[0099] It would be desirable to change the particle size distribution of the sorbent being injected in order to optimize the location of the sorbent deposition on the heat transfer surface. The objective is to predict the location of the mass distribution of condensed acid on the heat transfer surface, and size the sorbent particles so their momentum would enhance the distribution of the sorbent material on the heat transfer surface in direct relation to the distribution location of the condensed acid. In this manner, the ratio of sorbent material of the proper sizing can be deposited on the heat transfer surface in the optimum location to react with the amount of condensed acid at a given location.
[0100] In addition to the above control logic, a pressure drop across the air preheater 250 would be continuously measured by sensors 301 , 303 and compared to the calculated threshold (as defined in an algorithm installed in the PLC controller 305 ) as a function of the flue gas and air side flow rates and temperatures.
[0101] The predicted pressure drop vs. time relationship that would be desired to exist between sootblowing cycles of the heat transfer surface would also be an input to the PLC controller 305 . If the actual pressure drop increased at a faster rate, it would be indicative of a buildup of flyash deposit and sulfuric acid on the heat transfer surface due to an inadequate mass quantity of sorbent injection, incorrect particle size distribution of the sorbent material, or improper operation of the alkaline injection system 276 .
[0102] The PLC controller 305 would increase the sorbent injection rate in an attempt to return the pressure drop across the air heater vs. time relationship to the proper level. In addition, the sizing of the sorbent material would be altered by evaluating the various operating parameters used to control the system, and sending the proper signal to the pulverizing system to alter the sizing of the sorbent material as determined by the algorithm in the PLC controller 305 . Note that the sorbent particle sizing process would not be applicable if the sorbent was injected via a slurry or solution.
[0103] Conversely, if the rate of pressure drop increase was below the predicted level based on actual operating conditions as calculated in PLC controller 305 , the sorbent injection rate would be decreased to reduce operating costs.
[0104] During the sootblowing cycle, the flyash that has accumulated on the heat transfer surface since the last sootblowing cycle should be removed, and the resulting pressure drop across the air preheater would be reduced. However, if the deposit is too “wet” due to the presence of non-neutralized sulfuric acid, it will not be removed during the sootblowing cycle. Therefore, for a given flue gas flow rate and temperature, if the air preheater pressure drop vs. time relationship is greater than the standard profile that would be entered into the PLC controller 305 , it would indicate that not enough sorbent is available in the flue gas, and/or the particle size distribution of the sorbent material is incorrect for the current operating conditions. A signal would be sent from the PLC controller 305 to the alkaline injection system 276 to increase the sorbent injection rate and/or alter the sorbent particle size distribution.
[0105] If the proper mass rate of alkaline particles 275 is being provided according to PLC controller 305 , and the pressure drop exceed the calculated threshold, a larger relative ratio of large to small particles is provided as a sorbent 275 . More of the large particles will come in contact with the heat transfer surfaces and neutralize and consume the acids holding particulates to the surfaces. If the sensed pressure drop is below the threshold, a smaller relative ratio of large to small alkaline particles is provided, allowing for more small particles to act as nucleation sites in the flue gases.
[0106] PLC controller 305 may optionally control a pulverizer 277 to direct the pulverizer to grind of alkaline particles 275 of a desired size or a distribution of sizes.
[0107] Other operating parameters that could be integrated into the PLC controller 305 to determine the sorbent injection rate are the voltage and amperage of the electric motor that is used to drive the rotor ( 512 of FIG. 1B ) of the air preheater 250 . As the mass of particulate deposits increase on the heat transfer surface of the air preheater, the overall weight of the rotor will increase. For a given voltage to the motor, this will cause the amperage draw by the motor to increase due to the additional friction in the rotor support bearing system as a result of the increased weight of the rotor on the bearing assembly. Therefore, the rotor drive motor voltage and amperage would be continuously measured and fed to the PLC controller 305 and included in the overall calculation to determine the mass injection rate and particle size distribution of the sorbent. The PLC control logic would include the target amperage to be maintained, and the range of acceptable amperage swing that could result from the normal accumulation of flyash on the heat transfer surface that would occur during the sootblowing cycles for the heat transfer surface. The PLC controller 305 would include the calculation methods to accommodate voltage swings that might occur, and therefore, adjust the target amperage level to be maintained as a function of the actual voltage levels if necessary.
[0108] As noted above, the introduction of alkaline particles into the flue gas stream FG 1 greatly increases the effectiveness of the air preheater in capturing more heat from the flue gas stream FG 1 and reduces the fouling of the heat transfer surface. This permits the gas outlet temperature of the flue gas leaving the air heater to be reduced. Practical design and cost limitations tend to determine the temperature at which the preheated air will leave the air preheater. However, the maximum gas outlet temperature reduction can be achieved while maintaining the desired air temperature leaving the air preheater by increasing the mass flow of air passing through the air preheater. In view of this, some provisions may be made to distribute excess heat in the form of additional heated air side mass flow to operations other than furnace operations.
[0109] In a further embodiment of the proposed invention (See FIG. 2B ), an air preheater 250 is provided that is configured to distribute heat extracted from the flue gas FG 1 to the furnace 26 via air stream A 2 and to other purposes via auxiliary air stream(s) A 3 and/or B 2 . Possible uses for these auxiliary air streams may include, for example, coal mill drying and grinding operations and/or preheating boiler feed water, site heating or cooling processes, preheating of the air entering the air preheater by direct recirculation of a portion of the heated air leaving the air heater to the inlet side of the air preheater so that it is mixed with the ambient air prior to increase the temperature of the air flow entering the air heater, indirect heating of the ambient air via the use of a heat exchanger wherein a portion of the hot air leaving the air heater is used to preheat the incoming ambient air prior to entry into the regenerative air preheater. There are additional uses such as off site uses district heating for industrial processes requiring a source of heated air, and thermal energy provided to CO 2 capture systems, including but not limited to, chilled ammonia or amine injection processes.
[0110] With reference to FIG. 2B , the EPRS 215 includes a regenerative air preheater 250 , a particulate removal system 70 and a scrubber system 80 . An FD fan 60 is provided to introduce an air stream A 1 into the cold side of the air preheater 250 via inlet 251 . As described above, the particulate removal system 70 may include an ESP and/or a fabric filter system, or the like. Scrubber system 80 may include a WFGD/DFGD system.
[0111] In this embodiment, an additional FD fan 260 is provided to introduce an auxiliary air stream B 1 into the cold side of the air preheater 250 via inlet 256 .
[0112] FIG. 3B is a diagram generally depicting further details an air preheater 250 configured to provide an alternate stream of heated air to certain predefined operations other than to the furnace combustion chamber.
[0113] With reference to FIG. 3 , air preheater 250 is configured to include an inlet 251 for receiving an air stream A 1 and an auxiliary air inlet 256 for receiving an auxiliary air stream B 1 . An outlet 252 for outputting a heated air stream A 2 to a furnace ( 26 of FIG. 2B ). An auxiliary outlet 255 is also provided for outputting a second stream of heated air B 2 to one or more predetermined operations or pieces of equipment such as a mill ( 270 of FIG. 2B ). By having two separate outlets 252 and 255 , heated air streams A 2 and B 2 may be separately controlled and heat extracted from the flue gas stream FG 1 that is greater than is needed for proper operation of the furnace ( 26 of FIG. 2B ). Heated air streams A 3 , B 2 may be easily routed for use in other uses associated with the steam plant operations, or other plant related operations. Further, by providing two air inlets A 1 and B 1 , it is possible to selectively or variably control air input to the air preheater. The principles and concepts disclosed and claimed herein are applicable to all air preheater devices/systems, including but not limited to bi-sector, tri-sector and quad-sector air preheater devices and systems.
[0114] 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. | A thermally efficiency regenerative air preheater 250 extracts more thermal energy from the flue gas exiting a solid fuel fired furnace 26 by employing an alkaline injection system 276 . This mitigates acid fouling by selectively injecting different sized alkaline particles 275 into the air preheater 250 . Small particles provide nucleation sites for condensation and neutralization of acid vapors. Large particles are injected to contact and selectively adhere to the heat exchange elements 542 and neutralize liquid acid that condenses there. When the deposit accumulation exceeds a threshold, the apparatus generates and utilizes a higher relative percentage of large particles. Similarly, a larger relative percentage of small particles are used in other cases. Mitigation of the fouling conditions permits the redesign of the air preheater 250 to achieve the transfer of more heat from the flue resulting in a lower flue gas outlet temperature without excessive fouling. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a motor grader. More specifically, the invention relates to a motor grader with a multi-function operation lever which performs more than one function.
2. Description of the Related Art
A typical example of the conventional motor grader is illustrated in FIGS. 1. In the shown construction, the motor grader is provided with a draw bar 2 swingably mounted on the front end of a vehicle body 1. Left and right lifting cylinders 3 and 4 and a transporting cylinder 5 are connected between the draw bar 2 and the vehicle body 1. A swing circle 6 is mounted on the draw bar 2 for swing motion by means of a hydraulic swing motor 7. A blade 9 is mounted on the swing circle 6 via a bracket 8 of the latter for movement in lateral directions by means of a blade shifting cylinder 10. In addition, a leaning cylinder (not shown) is provided for front wheels 11 for leaning in the lateral directions.
Also, there are various known motor graders. For instance, a motor grader having a scarifier movable in the vertical direction by means of a scarifier cylinder has been known. Furthermore, a motor grader is known having an articulated vehicle body for arcuating by means of a steering cylinder.
In order to control the operations of various cylinders, a hydraulic swing motor and so forth, an output pressure of a hydraulic pump as a hydraulic pressure source is distributed to respective cylinders and the hydraulic motor via direction control valves. For controlling operation of respective direction control valves, a plurality of operation levers are provided in a work implement operating device of the motor grader. One example of the work implement operating device is illustrated in FIG. 2. As can be seen from FIG. 2, a plurality of operation levers which are generally represented by the reference numeral 12, are provided at both sides of a steering wheel 13. Respective operation levers 12 are connected to corresponding direction control valves via a link mechanism. In the example shown in FIG. 2, a right blade lifting operation lever 12a, a leaning operation lever 12b, and a blade shifting operation lever 12c are arranged at the right side of the steering wheel 13, and a draw bar shift operation lever 12d, a steering operation lever 12e, a swing circle operation lever 12f, a scarifier operation lever 12g and a left blade lifting operation lever 12h are arranged at the left side of the steering wheel 13.
With the operation device set forth above, since a plurality of operation levers are connected to the corresponding direction control valves by means of link mechanisms, the construction becomes complicated. Furthermore, for operating the work implement, one of more operation levers corresponding to a desired behavior of the work implement have to be selected, thus to make an operator's operation complicated. In addition, a plurality of operation levers arranged at both sides of the steering wheel may degrade forward sight.
For example, when the blade 9 is to be lifted or tilted, the left and right blade lifting operation levers 12a and 12h are operated. Also, when the blade 9 is to be shifted in the lateral direction, the blade shift operation lever 12c is operated, and when the swing circle 6 is to be swung, the swing circle operation lever 12f is operated. In addition, when the work implement has to be operated while the vehicle is running, the operator is required to operate both the steering wheel 13 and the operation levers 12 by frequently moving the hands between the steering wheel 13 and one more of the operation levers 12.
On the other hand, when the blade 9 is to be pivoted to vary an angle formed between the longitudinal axis of the vehicle body 1 and the blade 9, which angle will be hereafter referred to as a propulsion angle, the relevant operation levers 12 are operated to switch the valve positions of the corresponding direction control valves to drive the hydraulic swing motor 7 to pivot the blade 9 together with the swing circle 6. However, during this operation, the left and right ends of the blade 9 move along an arc so that the lateral positions of the left and right ends of the blade 9 may be differentiated between the positions before and after pivoting. Namely, when the propulsion angle of the blade is varied, the position of the ends of the blade 9 should be varied. This may cause a problem to cause collision of the blade with the shoulder of the road due to a difference in positions of the ends of the blade. To avoid this, it becomes necessary to cause a lateral shift of the blade upon varying the propulsion angle. This clearly requires extra operation for the lateral shifting of the blade to make the operator's operation more complicated.
On the other hand, in the prior art, there has been proposed a blade angle control device to automatically control a blade angle irrespective of variation of tilt angle of the vehicle body and/or the propulsion angle of the blade. The blade angle control device includes a target blade angle setting means, such as a dial, switch or so forth. The blade angle control device is designed to control the blade angle to the target angle set through the target blade angle setting means. For varying the target blade angle, it requires the manual operation of the operator against the target blade angle setting means.
Therefore, such blade angle control device is not applicable for the cases where the left and right cant of tilt angle varies sequentially with curving of the working road, or where the target blade angle has to be varied at the intersection with the other working road, for substantial difficulty occurs in setting or varying the target blade angle an appropriate value by the operator.
Also, when the blade is to be lifted up or down, both of the direction control valves corresponding to left and right lift cylinders 3 and 4 are to be operated. This requires operations of the left and right blade lifting operation levers 12h and 12a. Then, both hands of the operator are used for operating the left and right blade lifting operation levers 12h and 12a to make it impossible to operate the steering wheel 13. In addition, during lifting up and down of the blade 9, the blade may cause lateral shifting due to presence of the lateral feeding cylinder 5. Therefore, the operation of the lateral feeding cylinder 5 is further required to make the operator's operation more complicated in the extent that a qualified operator is required for performing the operation set forth above.
SUMMARY OF THE INVENTION
In view of various defects in the prior art, it is an object of the present invention to overcome problems in the prior art.
More specifically, an object of the present invention is to provide a work implement operating device which permits operation of a plurality of direction control valves with a reduced number of operation levers, which reduced number of operation levers will contribute to provide better forward sight to the operator.
Another object of the present invention is to provide a steering system for a road grader which permits steering operation of the vehicle without a steering wheel.
A further object of the present invention is to provide a blade pivoting system which can perform pivotal motion of the blade without varying the positions of the left and right side ends of the blade.
A still further object of the present invention is to provide a blade angle control system which permits variation of a blade angle irrespective of a target blade angle.
A yet further object of the present invention is to provide a blade lifting system which permits operation of left and right lifting cylinders and of the lateral feeding cylinder with a single operation lever.
A still further object of the present invention is to provide a blade lifting system which permits a lifting operation for one side of the blade while maintaining the other end at a constant level.
In order to accomplish the above-mentioned and other objects, according to a first aspect of the invention, an operation system for a motor grader including a plurality of hydraulic actuators for performing various functions and a plurality of valve means respective corresponding the actuators for controlling operation of the latter, comprises:
left and right operation levers provided within an operator cabin of the motor grader and operable in arbitrary directions for outputting operation command signals indicative of the operated directions;
a selector switch: and
a controller receiving the operation command signals from the left and right operation levers having values proportional to operation strokes thereof, and a select signal from the selector switch, the controller generating operation control signals to be supplied to at least one of the valve means corresponding to the operated direction represented by the operation command signal from one of the left and right operation levers, which operation control signal is supplied to different valve means depending upon the selection signal.
In the preferred construction, the left and right operation levers are operable in a back and forth direction and a left and right direction for producing the operation command signals representative of the operated direction and having a value proportional to the operation stroke. Each of the valve means comprises an electromagnetic proportioning valve, and the controller selects a work implement to be operated among a plurality of work implements carried by the motor grader on the basis of the operation command signals and the selection signal to output the operation control signals to the corresponding valve means.
According to a second aspect of the invention, an operation system for a motor grader including a plurality of hydraulic actuators for performing various functions and a plurality of valve means respectively corresponding the actuators for controlling operation of the latter, comprises:
left and right operation levers provided within an operator cabin of the motor grader and operable in arbitrary directions for outputting operation command signals indicative of the operated directions, the left operating lever being assigned for controlling a vehicular driving function and the right operation lever being assigned for controlling functions of work implements carried by the motor grader;
a selector switch; and
a controller receiving the operation command signals from the left and right operation levers having values proportional to operation strokes thereof, and a select signal from the selector switch, the controller generating operation control signal to be supplied to at least one valve means for at least one actuator for controlling vehicular driving behavior in response to the operation command signal from the left operation lever and for at least one of the actuators controlling operation of one of the work implements in response to the operation command signal from the right operation lever.
In this case, the left and right operation levers are operable in a back and forth direction and a left and right direction for producing the operation command signal representative of the operated direction and having a value proportional to the operation stroke. Each of the valve means comprises an electromagnetic proportioning valve, and the controller selects a work implement to be operated from among a plurality of work implements carried by the motor grader on the basis of the operation command signal from the right operation lever and the selection signal to output the operation control signal to the corresponding valve means.
According to a third aspect of the invention, a blade swing control system for a motor grader, in which a swing circle is mounted on a draw bar mounted on a vehicle body, for swing motion by means of a hydraulic swing motor, and a blade is mounted on the swing circle for lateral movement by means of a shift cylinder, comprises:
an operation lever operable at least in a back and forth direction and a left and right direction for generating an operation command signal representative of the operated direction and the operation stroke thereof;
a first electromagnetic proportioning valve for controlling pressure supply for the hydraulic swing motor;
a second electromagnetic proportioning valve for controlling pressure supply for the shift cylinder;
means for detecting a swing angle of the blade;
means for deriving lateral shifting magnitude of the blade; and
a controller for operating the first and second electromagnetic proportioning valves so that the second electromagnetic proportioning valve supplies a hydraulic pressure to the shift cylinder for causing lateral shifting of the blade in a magnitude corresponding to swing angle of the blade in conjunction with driving of the hydraulic swing motor for swinging the blade over an angle indicated by a swing angle commanded through the operation lever.
According to a fourth aspect of the invention, a control system for controlling a tilt angle of a blade of a motor grader, comprises:
an operation lever operable in an arbitrary direction to generate an operation command signal representative of the operated direction and the operation magnitude thereof;
left and right lifting cylinders for lifting up and down the blade;
means for detecting propulsion angle of the blade;
means for setting a target blade tilt angle;;
first and second electromagnetic proportioning valves for controlling pressure supply for the left and right lift cylinders; and
a controller for controlling the first and second electromagnetic proportioning valves on the basis of the target blade tilt angle and the blade propulsion angle in response to the operation of the operation lever in a first direction and for controlling the first and second electromagnetic proportioning valves for varying the tilt angle of the blade depending upon the operation command signal and updating the target blade tilt angle in response to the operation of the operation lever in a second direction different from the first direction.
According to a fifth aspect of the invention, a blade lifting control system for a motor grader including a draw bar supported on a vehicle body by means of left and right lifting cylinders for vertical swing motion, and a lateral feeding cylinder disposed between the draw bar and the vehicle body, comprises:
an operation lever operable in a back and forth direction for generating an operation command signal representative of the operated direction and the operation stroke;
a first electromagnetic proportioning valve for controlling pressure supply for the left lifting cylinder;
a second electromagnetic proportioning valve for controlling pressure supply for the right lifting cylinder;
a third electromagnetic proportioning valve for controlling pressure supply for the lateral feeding cylinder; and
a controller for outputting operation control signals to the first, second and third electromagnetic proportioning valves in response to the operation command signal from the operation lever.
According to a sixth aspect of the invention, a blade lifting control system for a motor grader including a draw bar supported on a vehicle body by means of left and right lifting cylinders for vertical swing motion, and a blade being mounted on the draw bar, comprises:
an operation lever operable in a back and forth direction for generating an operation command signal representative of the operated direction and the operation stroke;
a first electromagnetic proportioning valve for controlling pressure supply for the left lifting cylinder;
a second electromagnetic proportioning valve for controlling pressure supply for the right lifting cylinder; and
a controller responsive to the operation command signal from the operation lever for operating the first and second electromagnetic proportioning valves for establishing first and second fluid path areas in the first and second electromagnetic proportioning valves in a mutually independent manner.
According to a seventh aspect of the invention, a motor grader comprises:
a wheeled body for traveling and carrying at least one work implement;
at least one operation lever operable in a first direction for electrically generating a first operation command signal and a second direction perpendicular to the first direction for generating a second operation command signal;
a mode selector selectable at least between a first mode and a second mode for generating a mode selection signal; and
a controller receiving the first and second operation command signals and the mode selection signal for controlling different motor grader functions depending upon an input combination of the first and second operation command signals and the mode selection signal.
The controller may control a first motor grader function in response to the first operation command signal input while the mode selection signal is held at the first mode and a second motor grader function in response to the second operation command signal input while the mode selection signal is held at the first mode, a third motor grader function in response to the first operation command signal input while the mode selection signal is held at the second mode and a fourth motor grader function in response to the second operation command signal input while the mode selection signal is held at the first mode. The operation lever may be further operable in further directions oblique to the first and second directions, and the controller is responsive to the operation command signal from the operation lever as operated in one of a plurality of operating directions to control one of the motor grader functions unique to those to be controlled by the operation of the operation lever in any other directions.
In the preferred construction, the controller may control a first motor grader function to be performed by a first component of the motor grader in response to the first operation command signal input while the mode selection signal is held at the first mode and a second motor grader function to be performed by a second component different from the first component in response to the second operation command signal input while the mode selection signal is held at the first mode, a third motor grader function to be performed by a third component different from the first and second components in response to the first operation command signal input while the mode selection signal is held at the second mode and a fourth motor grader function to be performed by a fourth component different from the first, second and third components in response to the second operation command signal input while the mode selection signal is held at the first mode. In this case, at least one of the first, second, third and fourth motor grader functions is a composite function of a plurality of motor grader components including the corresponding one of the first, second, third and fourth components and at least one auxiliary component. Preferably, the auxiliary component is cooperative with the one of first, second, third and fourth components for compensating inherent undesirable action associated with operation of the one of first, second, third and fourth components.
In practice, the one of first, second, third and fourth components comprises a hydraulic motor for controlling swing motion of a blade, and the auxiliary component comprises a hydraulic cylinder for causing lateral shift of the blade for compensating lateral displacement inherently caused by swing motion of the blade.
In the alternative, the first function is vehicular traveling in forward and reverse directions and second function is a vehicular steering operation. In such case, the third function may be vehicular traveling in forward and reverse directions which is the same as the first function and the fourth function may be a leaning control function or a vehicular body arcuation control function.
In the further alternative, the controller is provided with a blade tilt angle adjusting function for adjusting a blade tilt angle toward a preset target tilt angle, and the controller is responsive to the first operation command signal from the operation lever while the mode selection signal is held at the first mode to perform automatic control of the blade tilt angle toward the target tilt angle, and to the first operation command signal while the mode selection signal is held at the second mode, to permit interactive blade tilt angle control through the operation lever for updating the target tilt angle with the manually set angle of the blade. The controller may also receive a first correction parameter representative of a propulsion angle of the blade and/or a second correction parameter representative of a tilt angle of the vehicular body for correcting the target blade tilt angle based thereon during operation in response to the first operation command input under the first mode of the mode selection signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.
In the drawings:
FIG. 1 is a side elevation showing a general construction of a motor grader;
FIG. 2 is a fragmentary illustration showing an example of an arrangement of operation levers in the conventional motor grader;
FIG. 3 is a perspective view of an operator cabin of the preferred embodiment of a motor grader according to the present invention;
FIG. 4 is an exploded and diagrammatic illustration showing components forming the preferred embodiment of an operation system for the motor grader according to the present invention;
FIG. 5 is a diagram of a hydraulic circuit of the preferred embodiment of the motor grader of the invention;
FIG. 6 is an illustration showing operating directions of a left operation lever in the preferred embodiment of the motor grader;
FIG. 7 is a chart showing a relationship between a magnitude of an operation command signal output from a left operation lever assembly and an operation stroke of a left operation lever;
FIGS. 8(a)˜8(f) are fragmentary illustrations of various attitudes of a blade to be situated by the preferred embodiment of the motor grader;
FIGS. 9(a)˜9(c) are illustrations showing a manner of swing motion of the blade in the preferred embodiment of the motor grader;
FIG. 10 is an illustration showing operating directions of a right operation lever according to the invention;
FIG. 11 is a chart showing a relationship between a magnitude of an operation command signal output from a right operation lever assembly and an operation stroke of a right operation lever;
FIG. 12 is a plan view showing an alternative arrangement of the operation levers of the present invention;
FIG. 13 is a side elevation of a portion where the operation lever is mounted;
FIG. 14 is a perspective view of the operator's cabin employing a further alternative arrangement of operation levers;
FIG. 15 is an enlarged plan view of the operation levers arranged in the manner illustrated in FIG. 14;
FIG. 16 is a perspective view of the operators cabin employing a still further alternative arrangement of operation levers;
FIG. 17 is an enlarged plan view of the operation levers arranged in the manner illustrated in FIG. 16;
FIG. 18 is a plan view showing a yet further alternative arrangement of the operation levers;
FIG. 19 is a perspective view of another embodiment of the motor grader according to the invention;
FIG. 20 is a diagram of a hydraulic circuit to be employed in the motor grader of FIG. 19; and
FIG. 21 is a front elevation of a display panel for setting a target blade tilt angle, which is employed in the preferred embodiment of the motor grader of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 3, there is illustrated the preferred embodiment of an operator's cabin or a cockpit 20 of a motor grader, according to the present invention. At both sides of a driver seat 21, a left operation lever assembly 22 and a right operation lever assembly 23 are arranged. The left and right operation lever assemblies 22 and 23 include operation levers 22a and 23a which can be manually operated by an operator. Also, a steering wheel 24 is positioned in front of the operator seat 21. The steering wheel 24 is supported on a supporting column 25.
The left and right operation lever assemblies 22 and 23 include electric signal generators, such as potentiometers for generating electric signals according to operation of the left and right operation levers 22a and 23a. The left and right operation levers 22a and 23a are designed to be operated in back and forth direction, a left and right direction, and in oblique directions, i.e. directions intermediate between the back and forth direction and left and right direction. Electric signals are generated in response to operation of the operation levers 22a and 23a representative of the operating direction of the operation levers. The magnitude of the electric signals is variable in proportion to the operation stroke of the operation lever. The electric signal generator, such as the potentiometer (not shown), is coupled with each operation lever 22a and 23a to generate the electric signal indicative of the operating direction and having the magnitude proportional to the operation stroke. The electric signals generated in response to the operation of the operation levers 22a and 23a will be hereafter referred to as "operation command signals".
The operation lever assemblies 22 and 23 are connected to a microcomputer based controller 26 for inputting the operation command signals thereto, as shown in FIG. 4. The controller 26 is also connected to an ON/OFF switch or mode selector switch 27 for generating an ON/OFF signal, a tilt sensor 28 for generating a vehicle body tilt angle indicative signal, and a rotation sensor 29 for generating a swing circle angular position indicative signal. The controller 26 receives the ON/OFF signal of the ON/OFF switch 27, the vehicle body tilt angle indicative signal of the tilt sensor 28 and the swing circle angular position indicative signal of the rotation sensor 29 in addition to the operation command signals of the operation levers 22a and 23a. The controller 26 processes these inputs to generate electric signals for controlling direction control valves, such as electromagnetic proportioning valves 30, for supplying hydraulic pressure to a hydraulic swing motor and various cylinders. The electric signals controlling the direction control valves will be hereafter referred to as "operation control signals". Also, the controller 26 outputs an electric signal to a display panel 31 for displaying the operating condition and so forth. The signal to be fed to the display panel will be referred to hereafter as a "display signal".
FIG. 5 shows a hydraulic circuit to be employed in the preferred embodiment of the motor grader according to the present invention. A first electromagnetic proportioning valve 30-1 is communicated with the left lifting cylinder 3 for supplying the hydraulic pressure thereto. A second electromagnetic proportioning valve 30-2 is communicated with the right lifting cylinder 4 to supply thereto the hydraulic pressure. Similarly, a third electromagnetic proportioning valve 30-3 is connected to a lateral feed cylinder 5 to supply thereto the hydraulic pressure. A fourth electromagnetic proportioning valve 30-4 is connected to a shift cylinder 10 for supplying the hydraulic pressure to the latter. A fifth electromagnetic proportioning valve 30-5 is connected to the steering cylinder 32 for arcuating the vehicle body 1 in order to bend the vehicle body at the front and rear portions. A sixth electromagnetic proportioning valve 30-6 is connected to the cylinder to supply the hydraulic pressure thereto. A seventh electromagnetic proportioning valve 30-7 is connected to a scarifier cylinder 34. An eighth electromagnetic proportioning valve 30-8 is connected to the hydraulic swing motor 7 to supply thereto the hydraulic pressure. These first to eighth electromagnetic proportioning valves 30-1˜30-8 are controlled as to the valve positions by the operation control signals from the controller 26. The first to eighth electromagnetic proportioning valves 30-1˜30-8 are connected to a hydraulic pump 35 as a hydraulic pressure source and are designed to be operated to vary the fluid path areas depending upon the magnitudes of the operation control signals so that the fluid path areas are proportional to the magnitude of the operation control signals.
As shown in FIG. 6, the left operation lever 22a is operated in the directions of backward (B), forward (F), leftward (L), rightward (R), forward right (FR), forward left (FL), backward right (BR) and backward left (BL) directions. At each operating directions illustrated in FIG. 6, the magnitude of the operation command signal is variable in proportion to the stroke of the operation lever 22a, as shown in FIG. 7. The example of FIG. 7 shows a relationship between the back and forth stroke and the operation command signal, in which the operation command signal becomes a maximum value at the full stroke position of the operation lever 22a in the forward direction and a minimum at the full stroke position in the backward direction. The operation command signal generated by the left operation lever assembly 22 is input to the controller 26. The controller 26 discriminates an operation pattern on the basis of the ON/OFF signal from the ON/OFF switch 27 for selecting a combination of the operation control signals.
For instance, at the OFF position of the ON/OFF switch 27, the controller 26 outputs the operation control signals of one of the combination shown in the following table 1.
TABLE 1__________________________________________________________________________Operation Pattern Operation Control Signals*1 Operation 30-1 30-2 30-3__________________________________________________________________________ON/ N Blade Stop 0 0 0OFF F Blade Down -1 -1 -β or -1/βSwitch FR Blade Right -1/2 or -α -1 -βOFF Down R Blade Stop 0 0 0 BR Blade Right Up +1/2 or a +1 +β B Blade Up +1 +1 +β BL Blade Left Up +1 +1/2 or +α 0 L Blade Stop 0 0 0 FL Blade Left Down -1 -1/2 or -α 0__________________________________________________________________________ Note: *1: Operating Direction α, β: Correction Coefficient
In the foregoing table 1, when the sign of the operation control signal is positive (+), the electromagnetic proportioning valves are switched to contract the corresponding cylinders, and when the sign of the operation control signals are negative (-), the electromagnetic proportioning valves are switched to expand the corresponding cylinders. With either sign, the value of the operation control signal is sequentially variable between 0to 1. Therefore, the indications +1 and -1 should be understood to indicate that the value of the operation control signal is within a range of 0 to +1 or -1 for adjusting the fluid flow path area in the electromagnetic proportioning valve.
Next, a discussion will be given for the operation of the blade in the operation patterns shown in the foregoing table 1. As shown in FIG. 8(a), when the left and right lifting cylinders 3 and 4 are expanded, the blade 9 is moved down. Conversely, by contracting the cylinders 3 and 4, the blade 9 is moved up. When the lateral feed cylinder 5 is expanded, the blade 9 is shifted toward the right. On the other hand, contraction of the lateral feed cylinder 5 causes shifting of the blade 9 toward the left. The shift cylinder 10 causes shifting of the blade 9 toward the left by expansion and toward the right by contraction.
When the blade 9 is to be moved down or lowered, the left and right lift cylinders 3 and 4 are simultaneously expanded. At the same time, the lateral feed cylinder 5 is expanded so that the blade 9 may be lowered on exactly the same vertical plane, as shown in FIG. 8(b). Namely, if the length of the lateral feed cylinder 5 is held constant, the downward movement of the blade 9 may cause a horizontal shift of the blade 9. In contrast, by adjusting the length of the lateral feed cylinder 5, the blade 9 can be moved down without causing shifting in the horizontal direction.
When the right side of the blade 9 is to be lowered, the left lift cylinder 3 is expanded in a given stroke, and the right lift cylinder 4 is also expanded in a stroke approximately double the given stroke of the left lift cylinder. In conjunction therewith, the lateral feed cylinder 5 is expended so that the blade 9 can be situated in the right side lowered position as shown in FIG. 8(c) without causing a variation of the position at the lower left side end 9a. Namely, by adjusting the length of the lateral feed cylinder 5, the blade 9 can be tilted with respect to the horizontal plane without causing shifting of the lower left side end of the blade 9.
On the other hand, when lifting up the right side of the blade 9, the left lift cylinder 3 is contracted for a given stroke, and the right lift cylinder 4 is contracted in a stroke approximately double the contraction stroke of the left lift cylinder 3. At the same time, the lateral feed cylinder 5 is also contracted to situate the blade at the right side risen position without causing a shifting of the lower left side end 9a as shown in FIG. 8(d).
When the left side is raised the left lift cylinder 3 is contracted in a given stroke and the right lift cylinder 4 is also lifted for a stroke approximately half the contraction stroke of the left lift cylinder 3. Then, the blade 9 can be situated at the left side raised position as shown in FIG 8(e). At this time, the position of the lower right side end 9b can be held in place.
When the left side is lowered, the left lift cylinder 3 is expanded for a given stroke and the right lift cylinder 4 is expanded for a stroke approximately half of the expansion stroke of the left lift cylinder 3.
On the other hand, when the ON/OFF switch 27 is held ON, the operation will take place in response to the operation of the operation lever 22a as shown in the following table 2.
TABLE 2______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-4 30-8______________________________________ON/OFF N Blade Stop 0 0Switch F Blade Turn Left +1 0ON FR Blade Turn Left While +1 +K.sub.1 (θ) Maintaining Right End Constant R Blade Shift Right 0 +1 BR Blade Turn Right While -1 +K.sub.2 (θ) Maintaining Right End Constant B Blade Turn Right -1 0 BL Blade Turn Right While -1 +K.sub.2 (θ) Maintaining Left End Constant L Blade Shift Left 0 -1 FL Blade Turn Left While +1 -K.sub.1 (θ) Maintaining Left End Constant______________________________________
The operation of the blade 9 in the case of the foregoing table 2 will be discussed.
When the blade 9 is turned or pivoted toward the left, the hydraulic swing motor 7 is driven to turn the blade 9 together with the swing circle 6 as shown by the arrow a of FIG. 9(a).
When the blade 9 is to be turned toward the left while maintaining the right end of the blade at the constant position, in conjunction with driving of the hydraulic swing motor 7 for driving the swing circle 6 to turn toward the left, the shift cylinder 10 is contracted to shift the blade 9 toward the right relative to the swing circle 6. By this, the right end 9c of the blade 9 can be maintained at the constant position as shown in FIG. 9(b).
Namely, when the blade 9 is turned toward the left as shown in FIG. 9(a), the right end 9c of the blade 9 is displaced toward the left depending upon the turning angle 8, i.e. K 1 , K 2 and the length of the blade. In practice, since the length of the blade 9 is known, the magnitude of a leftward shifting of the blade 9 can be arithmetically derived on the basis of the swing or pivoting angle 8 detected by the rotation sensor 29. Therefore, the stroke of the shifting cylinder 10 can be derived for compensating the arithmetically calculated leftward shift of the blade 9. By compensating such displacement by contraction of the shift cylinder 10, the right end 9c of the blade 9 can be held at the constant position.
When the blade 9 is to be shifted toward the right, the shift cylinder 10 is contracted to shift the blade toward the right.
When the blade 9 is to be turned to the right while maintaining the right end 9c at the constant position, the hydraulic motor 7 is driven in the direction opposite to the for a left turn. In conjunction therewith, the shift cylinder 10 is contracted to shift the blade 9. By this, the right end 9c of the blade 9 can be held at the constant position.
When the blade 9 is to be turned toward the right, the hydraulic swing motor 7 is driven in the opposite direction to that for a left turn, to turn the blade 9 in the direction of the arrow b of FIG. 9(a).
When the blade is to be turned toward the right while maintaining the left end 9d at the constant position, the shift cylinder 10 is expanded to shift the blade 9 toward the left in conjunction with turning the blade 9 toward the right by the hydraulic swing motor 7, as shown in FIG. 9(c). By this operation, the left end 9d of the blade 9 can be maintained at the constant position while the blade 9 is turned toward the right.
When the blade 9 is to be shifted toward the left, the shift cylinder 10 is expended to cause shifting of the blade 9 toward the left.
When the blade is to be turned to the left while maintaining the left end 9d at the constant position, the shift cylinder 10 is expanded to shift the blade 9 toward the left in conjunction with driving of the hydraulic swing motor 7 to turn the blade 9 toward the left. By this, left turn of the blade 9 while maintaining the left end 9d at the constant position can be achieved.
In the shown embodiment, the right operation lever 23a of the right operation lever assembly 23 is operable in the forward (F), backward (B), leftward (L) and rightward (R) directions, as shown in FIG. 10. At each operating direction, the operation command signal varies the magnitude thereof proportional to the operation stroke of the operation lever 23a, as shown in FIG. 41. Similarly to the operation through the operation lever 22a, the operation command signals of the operation lever assembly 23 are input to the controller 26. The controller 26 discriminates the operation pattern on the basis of the input operation command signal and the ON/OFF signal of the ON/OFF switch
The operation patterns to be commanded by the operation command signals while the ON/OFF switch 27 is held OFF are shown in the following table 3.
TABLE 3______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-3 30-7______________________________________ON/OFF N Stop 0 0Switch F Scarifier Down 0 +1OFF R Draw Bar Shift Right +1 0 B Scarifier Up -1 0 L Draw Bar Shift Left -1 0______________________________________
Namely, when the right operation lever 23a is operated frontwardly, the scarifier cylinder 34 is operated to lower the scarifier. When the right operation lever 23a is operated toward the right, the lateral feed cylinder 5 is expanded to shift the draw bar toward the right. When the right operation lever 23a is operated backwardly, the scarifier cylinder 34 is contracted to lift up the scarifier. On the other hand, when the right operation lever 23a is operated toward the left, the lateral feed cylinder 5 is contracted to shift the draw bar toward the left.
The operation patterns to be commanded by the operation command signals while the ON/OFF switch 27 is held ON are shown in the following table 4.
TABLE 4______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-3 30-7______________________________________ON/OFF N Stop 0 0Switch F Vehicle Body Arcuate toward +1 0ON Left R Front Wheel Right Leaning 0 +1 B Vehicle Body Arcuate toward -1 0 Right L Front Wheel Left Leaning 0 -1______________________________________
Namely, when the right operation lever 23a is operated frontwardly, the steering cylinder 32 is expanded to arcuate the vehicle body toward the left. When the right operation lever 23a is operated toward the right, the leaning cylinder 33 is expanded to cause a rightward leaning of the front wheel. When the right operation lever 23a is operated backwardly, the steering cylinder 32 is contracted to arcuate the vehicle body toward the right. On the other hand, when the right operation lever 23a is operated toward the left, the leaning cylinder 33 is contracted to cause a leftward leaning of the front wheel.
As shown in FIGS. 12 and 13, the left and right operation lever assemblies 22 and 23 are mounted on housings 40 provided at both sides of the operator seat 21 Namely, at both sides of the operator seat 21, boxes 41 are mounted. The housings 40 are respectively mounted on the front end faces 41a of the boxes 41. The upper plates 42 of respective housings 40 are descending frontwardly, while the left and right operation levers 22 and 23 respectively substantially perpendicular to the upper surfaces 42 of the housings 40.
With this arrangement, the left and right operation levers 22a and 23a are slightly tilted toward the front at the neutral positions so that they may be placed at vertical position as operated backwardly. This facilitates manual operation of these levers by the operator seated on the operator seat 21.
While the specific arrangement of the left and right operation lever assemblies 22 and 23 is illustrated and discussed hereabove, the arrangement of the operation lever assemblies 22 and 23 can be modified in various fashions. For instance, the operation lever assemblies 22 and 23 can be arranged as illustrated in FIGS. 14 and 15. In this case, housings 43 of the operation lever assemblies 22 and 23 are mounted on the supporting column 25 of the steering wheel 24. In this case, the operation levers 22a and 23a are extended from the upper surfaces of the housings 43.
Also, it is further possible to arrange both operation lever assemblies 22 and 23 on a common housing 43 at one side of the supporting column 25, as illustrated in FIGS. 16 and 17. Furthermore, as shown in FIG. 18, it is possible to arrange both operation lever assemblies 22 and 23 on the common housing 40 mounted on the operator seat 21.
As can be appreciated, the operating directions of the operation levers 22a and 23a and the associated operation patterns are not restricted to those set forth above and can be modified in various fashion. The following are examples of modifications of the operating directions of the operation levers 22a and 23a and the associated operation patterns.
When the left operation lever 22a is operated while the ON/OFF switch 27 is held OFF, the operation patterns illustrated in the following table 5 can be established:
TABLE 5______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-4 30-8______________________________________ON/OFF N Blade Stop 0 0Switch F Blade Turn Left +1 0OFF FR Blade Turn Left While +1 +K.sub.1 (θ) Maintaining Right End Constant R Blade Shift Right 0 +1 BR Blade Turn Right While -1 +K.sub.2 (θ) Maintaining Right End Constant B Blade Turn Right -1 0 BL Blade Turn Right While -1 +K.sub.2 (θ) Maintaining Left End Constant L Blade Shift Left 0 -1 FL Blade Turn Left While +1 -K.sub.1 (θ) Maintaining Left End Constant______________________________________
When the left operation lever 22a is operated while on the ON/OFF switch 27 is held ON, the operation patterns illustrated in the following table 6 can be established:
TABLE 6______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-3 30-7______________________________________ON/OFF N Stop 0 0Switch F Scarifier Down 0 +1ON R Draw Bar Shift Right +1 0 B Scarifier Up -1 0 L Draw Bar Shift Left -1 0______________________________________
When the right operation lever 23a is operated while on ON/OFF switch 27 is held OFF, the operation patterns illustrated in the following table 7 can be established:
TABLE 7__________________________________________________________________________Operation Pattern Operation Control Signals*1 Operation 30-1 30-2 30-3__________________________________________________________________________ON/ N Blade Stop 0 0 0OFF F Blade Down -1 -1 -β or -1/βSwitch FR Blade Right -1/2 or -α -1 -βOFF Down R Blade Stop 0 0 0 BR Blade Right Up +1/2 or -α +1 +β B Blade Up +1 +1 +β BL Blade Left Up +1 +1/2 or +α 0 L Blade Stop 0 0 0 FL Blade Left Down -1 -1/2 or α 0__________________________________________________________________________
When the right operation lever 23a is operated while the ON/OFF switch 27 is held ON, the operation patterns illustrated in the following table 8 can be established:
TABLE 8______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-5 30-6______________________________________ON/OFF N Stop 0 0Switch F Vehicle Body Arcuate toward +1 0ON Left R Front Wheel Right Leaning 0 +1 B Vehicle Body Arcuate toward -1 Right L Front Wheel Left Leaning 0 -1______________________________________
It should be noted that the practical operations according to the foregoing tables 5 to 8 are the same as those of the foregoing embodiment. With the shown arrangement, the turning of the blade can be controlled by the left operation lever 22a and the lifting up and down of the blade 9 can be controlled by the right operation lever 23a.
Also, it is possible to provide a function of steering for one of the operation lever assemblies 22 and 23. For instance, in the foregoing embodiment, it may be possible to provide functions of steering and vehicle drive direction switching for the left operation lever assembly 22 instead of functions for operating the scarifier, draw bar, arcuating of the vehicle body and leaning of the front wheel. Such embodiment is illustrated in FIGS. 19 and 20.
As shown in FIG. 19, the shown embodiment eliminates the steering wheel since the steering operation can be performed by the left operation lever assembly 22. For enabling switching of the driving direction of the vehicle, a forward/reverse switching cylinder 35 is provided in the hydraulic circuit as shown in FIG. 20. The forward/reverse switching cylinder 34 is connected to a forward/reverse switching direction control valve 30-8.
In such case, the operation patterns at the OFF and ON states of the ON/OFF switch are shown in the following tables 9 and 10.
TABLE 9______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-6 30-7 30-8______________________________________ON/OFF N Stop 0 0 0Switch F Forward 0 0 +1OFF FR Forward and Turn Right +1 0 +1 R -- -- -- -- FL Forward and Turn Left -1 0 +1 L -- -- -- -- B Reverse 0 0 -1 BR Reverse and Turn Right +1 0 -1 BL Reverse and Turn Left -1 0 -1______________________________________
TABLE 10______________________________________ Operation ControlOperation Pattern Signals*1 Operation 30-6 30-7 30-8______________________________________ON/OFF N Stop 0 0 0Switch F Forward 0 0 +1ON FR Forward and Turn Right +1 +1 +1 R -- -- -- -- FL Forward and Turn Left -1 -1 +1 L -- -- -- -- B Reverse 0 0 -1 BR Reverse and Turn Right +1 -1 -1 BL Reverse and Turn Left -1 +1 -1______________________________________
As can be seen, either at an ON or an OFF position of the ON/OFF switch, the forward driving of the vehicle can be commanded by operating the operation lever 22 frontwardly. The forward/reverse switching cylinder 34 is then expanded to establish a power transmission path in a power transmission for forward driving of the vehicle. The transmission speed ratio in the forward driving position may be selected through a shift lever or selector lever 36 provided at the left side of the operator seat 21, as shown in FIG. 19. On the other hand, when the operation lever 22 is operated backwardly, the forward/reverse switching cylinder 34 is contracted to establish a power transmission path in the power transmission for reverse driving of the vehicle. When the operation lever 22 is operated toward the front left or the back left, the steering cylinder 32 is contracted to steer the front wheel 11 toward the left. Similarly, when the operation lever 22 is operated toward the front right or the back right, the steering cylinder 32 is expanded to steer the front wheel 11 toward the right.
When the ON/OFF switch 27 is held ON, the leaning cylinder 33 is operated in addition to the steering cylinder 32 in response to operation of the operation lever 22 in the left and right directions. Namely, when the operation lever 22 is operated toward the front right or the back right while the ON/OFF switch 27 is held ON, the leaning cylinder 33 is expanded to cause a rightward leaning of the front wheel 11 to permit a smaller radius right-hand turn. Similarly, when the operation lever 22 is operated toward the front left or the back left while the ON/OFF switch 27 is held ON, the leaning cylinder 33 is contracted to cause a leftward leaning of the front wheel 11 for enabling a left-hand turning of the vehicle with a smaller radius.
The motor grader according to the present invention further has a feature of automatic an control of a tilt angle of the blade toward a target tilt angle. For enabling this, a display panel 51 (see FIG. 3) is provided on one side of the operator seat 21. FIG. 21 shows the detail of the display panel 51. The display panel 51 includes an automatic tilt angle control ON/OFF switch 52 for selecting an operational mode of the controller 26 between an automatic control mode and a manual control mode. The display panel 51 also includes a tilt angle setting UP/DOWN switch 53, through which the desired tilt angle of the blade 9 during automatic control mode operation can be set. During automatic control mode, the set target tilt angle is displayed on a display screen 54.
In an automatic control mode of operation, the controller 26 derives the expansion strokes of the left and right lift cylinders 3 and 4 in order to establish the blade tilt angle corresponding to the target tilt angle set through the display panel 51. On the other hand, the controller 26 monitors the actual tilt angle of the blade 9 on the basis of a blade tilt angle indicative signal input from a blade tilt angle sensor 55 which monitors a tilt angle of the blade in the lateral direction relative to the horizontal plan (see FIG. 1). Thus, the controller 26 may feedback control the blade tilt angle on the basis of the target tilt angle and the monitored actual tilt angle of the blade.
Also, the controller 26 derives a blade propulsion angle on the basis of the swing circle angular position indicative signal of the rotation sensor 29. On the basis of the propulsion angle and the vehicle body tilt angle indicative signal of the vehicle body tilt sensor 28, the controller 26 derives a correction value for the target blade tilt angle so that the blade tilt angle relative to the horizontal plane is maintained irrespective of variation of the propulsion angle and/or the vehicle body tilt angle.
When modification of the target blade tilt angle becomes necessary, modification of the target blade tilt angle can be performed in an interactive matter. Namely, for modifying the target blade tilt angle, the left operation lever 22a is operated to attain the desired tilt angle of the blade 9. Once the desired blade tilt angle is established, the operational force exerted on the left operation lever 22a is released. Then, the left operation lever 22a returns to the neutral position. In response to this, the controller 26 reads out the actual blade tilt angle from the blade tilt angle sensor 55 sets the read angle as the updated target blade tilt angle. Then, the modified blade tilt angle is displayed on the display screen 54.
With the construction set forth above, all of the objects and advantages sought for the present invention are achieved.
Although the invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodies within a scope encompassed and equivalents thereof with respect to the feature set out in the appended claims. | A motor grader includes a work implement operating device which permits operation of a plurality of direction control valve with reduced number of operation levers. The motor grader includes a wheeled body for traveling and carrying at least one work implement, at least one operation lever operable in a first direction for electrically generating a first operation command signal and a second direction perpendicular to the first direction for generating a second operation command signal and a mode selector selectable at least between a first mode and a second mode for generating a mode selection signal. A controller receives the first and second operation command signals and the mode selection signal for controlling different motor grader functions depending upon an input combination of the first and second operation command signals and the mode selection signal. | 4 |
BACKGROUND OF INVENTION
[0001] The present invention relates generally to diagnostic imaging systems and, more particularly, to a combined magnetic resonance (MR) and x-ray scanner having a rotatable anode.
[0002] A number of diagnostic imaging systems have been developed to assist physicians, radiologists, other healthcare providers, and researchers with non-invasive or minimally invasive detection and treatment of anatomical abnormalities and pathologies. These imaging systems include x-ray radiography, computed tomography (CT), single proton emission computed tomography (SPECT), positron emission tomography (PET), ultrasound, magnetic resonance imaging (MRI), and derivatives of each. Each of these diagnostic imaging systems, as well as other not specifically enumerated, are used to produce medical or other clinically valuable images based on the detection and processing of energy through a subject. Radiography was the first developed medical imaging technology and is predicated upon the projection of x-rays emitted by an x-ray tube toward a subject. A homogeneous distribution of x-rays then enters the subject and is modified by the degree to which the x-rays are removed from the beam by scattering and absorption within tissues in the subject. Since the attenuation properties of tissue, bone, soft tissue, and air inside the patient vary, a resulting heterogeneous distribution of x-rays emerges from the subject. This heterogeneous distribution of x-rays is detected by a typically flat x-ray detector on the other side of the subject and is used to generate a radiographic image of the heterogeneous distribution. The radiographic image is a picture of this heterogeneous x-ray distribution through the subject.
[0003] MRI is another diagnostic imaging technique or modality that uses magnetic fields that are approximately 10,000 to 60,000 times stronger than the earth magnetic field. When a substance such as human tissue is subjected to this extremely strong and uniform magnetic field, individual magnetic moments of the spins in the tissue attempt to align with this polarizing field, but precess about it in random order at their characteristic Larmor frequency. If the substance, or tissue, is subjected to a magnetic field (excitation field B 1 ) which is in the x-y plane and which is near the Larmor frequency, the net aligned moment, or “longitudinal magnetization”, in z, may be rotated, or “tipped”, into the x-y plane to produce a net transverse magnetic moment M t . A signal is emitted by the excited spins after the excitation signal B 1 is terminated and the signal may be received and processed to form an image.
[0004] When utilizing the signals to produce MR images, magnetic field gradients (G x , G y , and G z ) are employed. Typically, the region to be imaged is scanned by a sequence of measurement cycles in which these gradients vary according to the particular localization method being used. The resulting set of received NMR signals are digitized and processed to reconstruct an MR image using one of many well-known reconstruction techniques.
[0005] MRI produces a set of tomographic slices through the subject, where each point in the image is predicated upon the micromagnetic properties of corresponding tissue at that point. Since different types of tissue such as fat, white and gray matter in the brain, cerebral spinal fluid, and cancers all have different local magnetic properties, images generated using MRI demonstrate high sensitivity to anatomical variations and are, therefore, typically high in contrast. As a result of this relatively high sensitivity to anatomical variations, MRI is frequently used in neurological imaging, muscle skeletal applications, as well as blood flow imaging.
[0006] As noted with respect to MRI, each diagnostic modality may be the preferred depending upon patient characteristics as well as the goal of the diagnostic imaging process. For example, radiographic or x-ray imaging is typically utilized for the detection of skeletal pathologies such as bone fractures. Since ultrasound is less harmful than ionizing radiation to a growing fetus, ultrasound imaging is typically preferred in obstetric patients. CT is often utilized for the detection of cancers, ruptured discs, subdural hematomas, aneurysms, as well as a large number of additional pathologies. Because of this relative independence between each of the imaging modalities, recent developments in diagnostic imaging system design have included the combination of multiple imaging modalities into a single scanner. For example, a hybrid MRI and a digital subtraction angiography scanner has been proposed wherein each imaging system is maintained in separate rooms that utilizes a single table for transferring patients between the imaging units. With this combined or hybrid system, standard clinical imaging as well as interventional procedures may be carried out with minimal repositioning of the patient. A drawback of this proposed hybrid system, however, is that two separate and independent scanners must be housed and maintained. That is, the independence of each scanner is maintained with a minimal interdependence of a common table to transfer the patient from the MR scanner to the angiographic system and vice-versa.
[0007] Another proposed hybrid system combines MR and x-ray in a single scanner. Such a scanner enables both x-ray fluoroscopy and MRI in a single exam without requiring patient repositioning as was typically required of combination or hybrid systems. With this proposed scanner, a flat panel x-ray detector is placed underneath the patient bed and a fixed anode x-ray tube is positioned overhead with the anode-cathode axis aligned with the main magnetic field and a high frequency x-ray generator. Since an MR system must maintain a very stable, uniform high magnetic flux field in order for the system to acquire accurate signals for image reconstruction, this hybrid MR/x-ray system referenced above implements a fixed or stationary anode. Typically, a stand-alone x-ray scanner utilizes a rotating anode. The anode is typically rotated using an induction motor. An induction motor, however, generates a magnetic flux that is disruptive to the substantially homogeneous magnetic field required for effective MR data acquisition and, therefore, would cause artifacts in the reconstructed image. A stationary, or fixed, anode, however, greatly reduces the x-ray dose available for radiographic data acquisition.
[0008] As is generally well known, the anode is a metal target electrode that is maintained at a positive potential difference relative to a cathode. Electrons striking the anode deposit most of their energy as heat with a small fraction emitted as x-rays. Consequently, the production of x-rays, in quantities necessary for acceptable image quality, generates a large amount of heat in the anode. With stationary, or fixed, anode configurations, a tungsten insert is embedded in a copper block. The copper block serves a dual role as support for the tungsten target as well as for removal of heat from the tungsten target. However, the small target area limits heat dissipation and consequently limits the maximum tube current and thus the x-ray flux. Rotating anodes, in contrast, have superior heat-loading characteristics and, consequently, higher x-ray output capabilities than stationary, or fixed, anode configurations. Electrons impart their energy on a continuously rotating target thereby spreading thermal energy over a large area and mass of the anode disc. Generally, an induction motor is used to rotate the anode during data acquisition. This rotation not only fans the x-ray beam, but also dissipates heat from the tungsten target across the surface and mass of the anode disc. As a result of these improved heat dissipating characteristics, the tube current for rotating anode configurations may be significantly greater than that typically used for stationary anode configurations. X-ray dose is directly proportional to the tube current and, as such, an increase in tube current provides an increase in available x-ray dosage for data acquisition. However, as noted above, typical rotating anode assemblies utilize an induction motor to induce rotation. The induction motor, however, generates a magnetic flux that would be disruptive to the homogeneous magnetic field required for MR data acquisition if incorporated in a conventional MR scanner. In this regard, a rotating anode configuration has been deemed impractical for a hybrid or combined MR/x-ray scanner.
[0009] It would, therefore, be desirable to design a hybrid MR/x-ray scanner having a rotatable anode that may be rotated during data acquisition without disrupting the substantially homogeneous magnetic field required for MR data acquisition. It would be further desirable to have such a hybrid scanner that does not require patient repositioning to acquire the respective types of diagnostic data.
SUMMARY OF INVENTION
[0010] The present invention is directed to an MR/x-ray scanner having a rotatable anode that overcomes the aforementioned drawbacks.
[0011] A hybrid MR/x-ray scanner is disclosed that allows for the acquisition of x-ray as well as MR data in a single exam without requiring patient repositioning. As an MR scanner, the hybrid system is capable of providing images with soft tissue contrast, excellent 3D visualization, the ability to image in multiple scan planes, as well as the possibility of providing physiological information. The x-ray capabilities of the single hybrid scanner include providing high resolution, real-time 2D projections with excellent contrast for the guidance and placement of catheters, stints, platinum coils, and other metallic devices. A number of interventional procedures may benefit from using the disclosed scanner for both x-ray and MR image generation. For example, transjugular intrahepatic portosystemic shunt is a common clinical procedure that is used to treat bleeding esophageal varices due to portal-venous hypertension. The chemoembolization of hepatic tumors may also benefit from the disclosed hybrid scanner. A number of other applications may also benefit from the hybrid MR/x-ray system disclosed. Those procedures include vascular applications, biliary drainages, abscess drainages, gallstone removal, precutaneous nephrostomy, and kidney stone removal. Other interventional procedures as well as minimally invasive procedures may also benefit from the present invention.
[0012] The disclosed MR/x-ray system includes a rotatable anode that is driven by a motor such that the relatively homogeneous magnetic field necessary for MR data acquisition is not disturbed during the acquisition of radiographic data. The rotating anode has greater heat loading and consequent higher x-ray output capabilities compared to that of a fixed, or stationary, anode.
[0013] Therefore, in accordance with one aspect of the present invention, an imaging system is disclosed that includes an MR imaging apparatus to acquire MR data of a subject as well as an x-ray imaging apparatus having a rotatable anode integrally disposed in the MR imaging apparatus to acquire radiographic data of the subject.
[0014] In accordance with another aspect of the present invention, an MR apparatus is disclosed that includes an MR imaging system having a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images. The MR apparatus further includes a motor assembly configured to control rotation of a rotatable anode disposed in the bore of the magnet.
[0015] According to another aspect of the present invention, a method of diagnostic imaging includes the steps of impressing a substantially homogeneous magnetic field about a subject and projecting high frequency electromagnetic energy at the subject. The method further includes the steps of rotating an anode of a high frequency electromagnetic energy tube assembly in the magnetic field during the projecting, and acquiring MR and radiographic data from the subject.
[0016] Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0017] The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.
[0018] In the drawings:
[0019] FIG. 1 is a schematic block diagram of a combined MR and x-ray imaging system for use with the present invention.
[0020] FIG. 2 is a cross-sectional view of an x-ray tube assembly.
[0021] FIG. 3 is a partial cross-sectional view of the anode assembly shown in FIG. 2 .
[0022] FIG. 4 is a perspective view of a piezoceramic motor for use with the present invention.
DETAILED DESCRIPTION
[0023] A hybrid MR/x-ray scanner is disclosed. The scanner has a rotatable anode that is driven by a motor such that magnetic flux is not introduced into a relatively homogeneous B magnetic field during data acquisition. The disclosed scanner enables both x-ray and MR data acquisition in a single exam without requiring patient repositioning.
[0024] Referring to FIG. 1 , the major components of a hybrid magnetic resonance imaging (MRI) and x-ray system 10 incorporating the present invention are shown. The operation of the MRI system is controlled from an operator console 12 which includes a keyboard or other input device 13 , a control panel 14 , and a display screen 16 . The console 12 communicates through a link 18 with a separate computer system 20 that enables an operator to control the production and display of images on the display screen 16 . The computer system 20 includes a number of modules which communicate with each other through a backplane 20 a . These include an image processor module 22 , a CPU module 24 and a memory module 26 , known in the art as a frame buffer for storing image data arrays. The computer system 20 is linked to disc storage 28 and tape drive 30 for storage of image data and programs, and communicates with a separate system control 32 through a high speed serial link 34 . The input device 13 can include a mouse, joystick, keyboard, track ball, touch activated screen, light wand, voice control, or any similar or equivalent input device, and may be used for interactive geometry prescription.
[0025] The system control 32 includes a set of modules connected together by a backplane 32 a . These include a CPU module 36 and a pulse generator module 38 which connects to the operator console 12 through a serial link 40 . It is through link 40 that the system control 32 receives commands from the operator to indicate the scan sequence that is to be performed. The pulse generator module 38 operates the system components to carry out the desired scan sequence and produces data which indicates the timing, strength and shape of the RF pulses produced, and the timing and length of the data acquisition window. The pulse generator module 38 connects to a set of gradient amplifiers 42 , to indicate the timing and shape of the gradient pulses that are produced during the scan. The pulse generator module 38 can also receive patient data from a physiological acquisition controller 44 that receives signals from a number of different sensors connected to the patient, such as ECG signals from electrodes attached to the patient. And finally, the pulse generator module 38 connects to a scan room interface circuit 46 which receives signals from various sensors associated with the condition of the patient and the magnet system. It is also through the scan room interface circuit 46 that a patient positioning system 48 receives commands to move the patient to the desired position for the scan.
[0026] The gradient waveforms produced by the pulse generator module 38 are applied to the gradient amplifier system 42 having G x , G y , and G z amplifiers. Each gradient amplifier excites a corresponding physical gradient coil in a gradient coil assembly generally designated 50 to produce the magnetic field gradients used for spatially encoding acquired signals. The gradient coil assembly 50 forms part of a magnet assembly 52 which includes a polarizing magnet 54 and a whole-body RF coil 56 . A transceiver module 58 in the system control 32 produces pulses which are amplified by an RF amplifier 60 and coupled to the RF coil 56 by a transmit/receive switch 62 . The resulting signals emitted by the excited nuclei in the patient may be sensed by the same RF coil 56 and coupled through the transmit/receive switch 62 to a preamplifier 64 . The amplified MR signals are demodulated, filtered, and digitized in the receiver section of the transceiver 58 . The transmit/receive switch 62 is controlled by a signal from the pulse generator module 38 to electrically connect the RF amplifier 60 to the coil 56 during the transmit mode and to connect the preamplifier 64 to the coil 56 during the receive mode. The transmit/receive switch 62 can also enable a separate RF coil (for example, a surface coil) to be used in either the transmit or receive mode.
[0027] The MR signals picked up by the RF coil 56 are digitized by the transceiver module 58 and transferred to a memory module 66 in the system control 32 . A scan is complete when an array of raw k-space data has been acquired in the memory module 66 . This raw k-space data is rearranged into separate k-space data arrays for each image to be reconstructed, and each of these is input to an array processor 68 which operates to Fourier transform the data into an array of image data. This image data is conveyed through the serial link 34 to the computer system 20 where it is stored in memory, such as disc storage 28 . In response to commands received from the operator console 12 , this image data may be archived in long term storage, such as on the tape drive 30 , or it may be further processed by the image processor 22 and conveyed to the operator console 12 and presented on the display 16 .
[0028] Scanner 10 further includes an x-ray tube assembly 70 and detector assembly 72 for radiographic data acquisition. The x-ray tube assembly 70 is positioned within the bore of the magnet assembly 52 and includes a rotatable anode that is driven and controlled during data acquisition such that disturbances to the homogeneous magnetic field are avoided. Utilization of a rotating anode allows for increased x-ray dose availability relative to a stationary, or fixed, anode. Flat panel detector 72 is operationally connected to an x-ray data acquisition system 76 that is controlled by system control 32 or other central control. The system control includes an x-ray controller 74 designed to regulate operation of the x-ray components of the hybrid scanner.
[0029] Referring now to FIG. 2 , components of x-ray tube assembly 70 are shown. The x-ray system 70 includes an anode 78 and a cathode 80 that collectively form an x-ray generating device or x-ray tube 82 . A fluid chamber 84 is provided and housed within a lead-lined casing 86 . Fluid chamber 84 is typically filled with coolant 88 that will be used to dissipate heat within the x-ray generating device 82 . Coolant 88 is typically a dielectric oil, but other coolants including air may be implemented. An oil pump (not shown) circulates the coolant through the x-ray system 70 to cool the x-ray generating components 82 and to insulate casing 86 from high electrical charges found within vacuum vessel 90 . To cool the coolant to proper temperatures, a radiator (not shown) is provided. Fans (not shown) may also be mounted near the radiator to provide cooling air flow over the radiator as the dielectric oil circulates therethrough. Electrical connections are provided in anode receptacle 92 and cathode receptacle 94 that allow electrons 96 to flow through the x-ray system 70 .
[0030] Casing 86 is typically formed of an aluminum-based material and lined with lead to prevent stray x-ray emissions. A motor assembly 98 is also provided adjacent to vacuum vessel 90 and within the casing 86 . In a preferred embodiment, motor assembly is a radial flux motor. A window 100 is provided that allows for x-ray emissions created within the system 70 to exit the system and be projected toward a subject, such as a medical patient for diagnostic imaging. Typically, window 100 is formed in casing 86 . Casing 86 is designed such that most generated x-rays 102 are blocked from emission except through window 100 .
[0031] Anode 78 includes a rotating, disc-shaped anode disc 104 . Upon excitation of an electrical circuit connected to the cathode 78 and the anode 80 , electrons 96 which are directed and accelerated towards the anode 78 strike the surface of the anode disc 104 and thereby produce high frequency electromagnetic waves 102 in the x-ray spectrum. The x-rays are then directed out of the x-ray system 70 through transmissive window 100 toward the object. Rotation of the anode disc 104 improves the thermal load of the anode thereby allowing higher tube currents. Higher tube currents enable greater dose availability for data acquisition.
[0032] Referring now to FIG. 3 , anode 78 includes anode disc 104 that is attached to a rotor 108 and bearings 109 of motor assembly 98 via stem 106 . It is preferred that a poor heat conductive material be used to attach the anode disc to the rotor/bearing assembly. Molybdenum is commonly used in rotating anode configurations because of its poor heat conductive characteristics to reduce heat transfer from the anode disc to the bearings. Bearing mounted rotor 108 supports the anode disc 104 within the evacuated x-ray tube. Positioned around the rotor 108 , in the illustrated embodiment, is a stator assembly 110 that induces rotation of anode disc 104 . The anode disc 104 may be caused to rotate at speeds up to 10,000 revolutions per minute.
[0033] Still referring to FIG. 3 , anode 78 also includes, in one embodiment, an energy storage device such as a spring 112 operationally connected to rotor 108 and housed within bearing cartridge 109 . Spring 112 is attached to the rotor and configured such that energy is stored in the spring when the anode disc 104 is counter-rotated. In this regard, alternating current may be supplied to stator 110 so as to induce counter-rotation of rotor 108 . This counter-rotation effectively tightens or stores energy in spring 112 .
[0034] Prior to data acquisition, the rotor is caused to counter-rotate so as to store energy in spring 112 . Once a sufficient amount of energy is stored in the spring, the counter-rotational bias placed on the rotor is removed. As a result, the energy stored in spring 112 is allowed to release thereby causing rotation of rotor 108 . Since the motor is turned off and the anode disc is caused to rotate by spring 112 alone, magnetic field disturbances are not caused. Accordingly, MR and x-ray data acquisition may be carried out at higher x-ray dosage levels and with a relatively homogeneous magnetic field. Since most MR scans are completed within 60 minutes, it is preferred that spring 112 be constructed to support a 60 minute rotation of anode disc 104 so that higher dosage levels may be utilized throughout the entire MR data acquisition period.
[0035] In another embodiment, anode 78 is constructed without spring 112 . In this embodiment, rotation of rotor 108 is caused at a sufficient frequency or revolutions per minute such that once the rotational bias is removed, momentum generated in the rotor 108 will support rotation of the anode disc throughout the imaging exam. For example, anode disc 104 may be caused to rotate at a frequency of 200 Hz. Once a frequency of 200 Hz or higher is reached and maintained, the motor 98 is turned off and thereby is no longer inducing rotation of disc 104 . Momentum forces, however, cause continued rotation of the anode disc 104 despite removal of the bias placed thereon by the motor 98 . Preferably, the rotor and bearing assemblies are constructed such that the wind-down time of the anode disc 104 is approximately sixty minutes or the length of a conventional MR scan.
[0036] Referring now to FIG. 4 , a piezoceramic motor that is applicable with the present invention is illustrated. Piezoceramic motor 114 induces rotation in the anode disc without disturbing the relatively homogeneous B o magnetic field necessary for MR data acquisition. Piezoceramic motor 114 includes a slider component 116 and a piezoceramic vibrator component 118 . An elastic vibrator component 120 is sandwiched between slider 116 and piezoceramic vibrator 118 . As is generally well known, piezoceramic motors convert voltage and charge to force and motion. In this regard, an alternating current is supplied that through piezoelectric properties induces motion in slider component 116 . Slider 116 is operationally connected to the anode stem such that when a sufficient voltage and current is supplied rotation of the anode stem is caused. That is, in a power stroke, the slider disengages the anode stem and, in a thrust stroke, the slider engages the stem and imparts a force thereon. If the power thrust cycle is repeated at a sufficient frequency, rotation of the stem may be caused. One skilled in the art will appreciate that the voltage and current levels may be controlled so as to induce more motion and force in one direction than in another. As a result, rotation of the anode disc in a desired direction may be effectively achieved. Further, one skilled in the art will readily recognize that other piezoelectric or ultrasonic motors may be equivalently applicable with the present invention.
[0037] Therefore, in accordance with one embodiment of the present invention, an imaging system is disclosed that includes an MR imaging apparatus to acquire MR data of a subject as well as an x-ray imaging apparatus having a rotatable anode integrally disposed in the MR imaging apparatus to acquire radiographic data of the subject.
[0038] In accordance with another embodiment of the present invention, an MR apparatus is disclosed that includes an MR imaging system having a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images. The MR apparatus further includes a motor assembly configured to control rotation of a rotatable anode disposed in the bore of the magnet.
[0039] According to another embodiment of the present invention, a method of diagnostic imaging includes the steps of impressing a substantially homogeneous magnetic field about a subject and projecting high frequency electromagnetic energy at the subject. The method further includes the steps of rotating an anode of a high frequency electromagnetic energy tube assembly in the magnetic field during the projecting, and acquiring MR and radiographic data from the subject.
[0040] The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims. | A hybrid MR/x-ray scanner is disclosed that allows for the acquisition of x-ray as well as MR data in a single exam without requiring patient repositioning. As an MR scanner, the hybrid system is capable of providing images with soft tissue contrast, excellent 3D visualization, the ability to image in multiple scan planes, as well as the possibility of providing physiological information. The x-ray components of the hybrid scanner include a rotatable anode that rotates during data acquisition and is caused to rotate without introduction of unwanted magnetic flux to the MR magnetic field. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for making paper from a solution including various kinds of fiber base materials and fillers dispersed in water, and more particularly to a method and apparatus for making raw paper as an intermediate of a wet friction material for use as a friction plate.
2. Description of the Related Art
Conventionally, annular frictional materials for use as frictional plates and the like have been made by punching from sheets of paper before or after the paper are thermoset while impregnating with thermosetting resin. However, since the yield of the raw material under this method is low, there have recently been developed new methods of directly making such annular frictional plates out of raw paper (e.g., JP-A-2-91294, JP-A-3-76780, JP-A-3-107628, etc.).
On the other hand, in the case of obtaining discontinuous paper bodies such as handmade paper, there still exists a problem of bad formation, and JP-A-11-241290 discloses a method of improving the formation.
According to the conventional methods and apparatus for manufacturing discontinuous paper bodies such as annular bodies, the paper formation has not necessarily been satisfactory.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a paper making method and apparatus for obtaining discontinuous paper bodies with further good paper formation.
In order to solve the foregoing problem, according to the present invention, there is provided a method of making a discontinuous paper body, including the steps of: feeding a raw material with a predetermined concentration into water which is in a stirred condition; maintaining the stirring condition for a predetermined time after the feeding step is completed; and passing the raw material diluted with the water through a wire cloth, while the stirred condition is maintained. Further, there is provided an apparatus for making paper, including: a stirring tank including: an outer cylinder; a middle cylinder disposed concentrically with said outer cylinder; a raw-material feeding port for feeding raw-material into said stirring tank; stirring mechanisms; and a top plate for holding said outer and middle cylinders in a predetermined position, and a paper making portion installed below the stirring tank, said paper making portion including: a wire cloth; and a paper making frame having an opening for holding the wire cloth, the opening being connected to a suction unit, wherein the stirring mechanisms are uniformly disposed above the wire cloth.
In addition, there is provided a paper making method wherein raw material is supplied from a raw-material feeding port disposed above a wire cloth uniformly onto the wire cloth. Further, there is provided a paper making apparatus includes a stirring tank including an outer cylinder, raw-material feeding ports for supplying raw material, stirring mechanisms, and a top for holding these members in position, wherein a paper making portion which is disposed in the lower portion of the stirring tank, has a central body having an opening for holding wire cloth and is connected to a suction unit, wherein said raw-material feeding ports are uniformly disposed above the wire cloth or the raw material is supplied from the raw-material feeding ports alternately disposed with respect to the central annular line of the paper making portion of wire cloth or each raw-material feeding port is directed toward the outer peripheral face of the middle cylinder or each raw-material feeding port is directed toward the upper apex of the conical surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a paper making apparatus according to a first embodiment of the present invention;
FIG. 2 is a sectional view of FIG. 1 ;
FIG. 3 is a top view of a paper making portion according to the first embodiment;
FIG. 4 is a view showing a separate condition of a stirring tank and the paper making portion according to the first embodiment;
FIG. 5 is a top view of an arrangement of stirring mechanisms according to the first embodiment;
FIG. 6 is a top view of another arrangement of stirring mechanisms according to the first embodiment;
FIG. 7 is a top view of a paper making apparatus according to a second embodiment of the present invention;
FIG. 8 is a sectional view taken along the line VIII—VIII of FIG. 7 ;
FIG. 9 is a top view of a paper making portion according to the second embodiment;
FIG. 10 is a view showing an arrangement of raw-material feeding ports according to the second embodiment;
FIG. 11 is a view showing another arrangement of raw-material feeding ports according to the second embodiment;
FIG. 12 is a sectional view taken along the line XII—XII of FIG. 7 and showing a paper making apparatus that is separated;
FIG. 13 is a top view of a paper making apparatus according to a third embodiment of the invention;
FIG. 14 is a sectional view taken along the line XIV—XIV of FIG. 13 ;
FIG. 15 is a top view of a paper making apparatus according to a fourth embodiment of the invention;
FIG. 16 is a sectional view taken along the line XVI—XVI of FIG. 15 ;
FIG. 17 is a top view of a paper making apparatus according to a fourth embodiment of the invention;
FIG. 18 is a sectional view taken on line XVIII—XVIII of FIG. 17 ; and
FIG. 19 is a sectional view of a paper making apparatus according to a sixth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A paper making apparatus according to a first aspect of the invention is structured that an outer cylinder, a middle cylinder, stirring air nozzles, a cleaning fluid jet mechanism and a raw-material feeding port are secured to a top plate. The air nozzles are uniformly arranged above the central annular line of a paper making portion of a wire cloth or alternately arranged with respect to the central annular lines thereof. The paper formation is improved on a condition that the air nozzles are uniformly arranged without being biased to the upper portion of the paper making portion of the wire cloth. Consequently, it is also preferable to uniformly arrange the directions of openings for jetting air without being biased in one direction.
The middle cylinder is formed in a substantially conical shape and the raw-material feeding port is provided above the apex of the substantially conical portion, so that the thickness of a paper body can be uniformed.
Further, a water jet is used as the cleaning fluid jet mechanism. A jet of water from the water jet may be performed in the form of a mist, waterdrops or a line of water, but it is preferable that a plurality of water jets are provided so that the fluid can equally be sprayed on the whole inside of a stirring tank.
In addition, a paper making apparatus according to a second aspect of the invention is structured that an outer cylinder, a middle cylinder, stirring air nozzles, a cleaning fluid jet mechanism, raw-material feeding ports and the like are secured to a top. The raw-material feeding ports are uniformly arranged above the central annular line of a paper making portion of a wire cloth or alternately arranged with respect to the central annular lines thereof. Moreover, the raw-material feeding ports are directed to the outer peripheral surface of the inner cylinder. Otherwise, the central body of a paper making frame is formed in a conical shape, whereby to construct the raw-material feeding ports above the apex. By feeding the raw material from the raw-material feeding ports, the concentration of the raw material before the operation of making paper is uniformed without imbalance.
The paper making portion of the wire cloth means an exposed portion between the outer cylinder and the central body, that is, a portion where the paper body is remained on the wire cloth after the paper making operation. Further, the central body is structured to form a central hole of an annular paper body.
The raw-material feeding ports are only needed for allowing the raw material to be fed and the diameter of each jet hole is set to be large enough to prevent the raw material from being clogged.
[First Embodiment]
With reference to FIGS. 1 to 6 , a description will be given of a paper making apparatus according to a first embodiment of the invention. As shown in FIGS. 1 to 3 , a paper making apparatus 1 includes a stirring tank 2 and a paper making portion 3 . The stirring tank 2 includes a middle cylinder 21 , an outer cylinder 23 concentric with the middle cylinder 21 , a raw-material feeding port 24 , air nozzles 25 as stirring mechanisms and jet holes 28 , which are respectively secured to an aluminum top plate 26 . The middle cylinder 21 has a substantially conical portion 22 in the lower end portion thereof. The jet holes 28 jet water for cleansing the middle cylinder 21 and the outer cylinder 23 . A seal ring 27 is also secured to the lower end portion of the outer cylinder 23 .
The paper making portion 3 is structured such that a wire cloth 31 is fitted to the top of a paper making frame 32 and a cover 34 for collecting moisture component such as the overflowed raw material is located in the outside of the paper making frame 32 . Reference numeral 38 denotes a water supply port; 33 , a moisture suction port; 35 , a discharge port of the cover 35 ; 45 , a central body; and 46 , an opening. FIG. 3 is a top view of the paper making portion 3 .
The apparatus shown in the drawings is designed to form an annular paper body as a discontinuous paper body, and the central body 45 forms a central hole.
FIG. 4 shows a condition that the stirring tank 2 and the paper making portion 3 in the apparatus shown in FIGS. 1 and 2 are separated from each other. FIGS. 5 and 6 are top views showing an arrangement of air nozzles 25 as stirring mechanisms.
As shown in FIG. 4 , the stirring tank 2 is separated from the paper making portion 3 and cleansed in another place where smudges adhered to the inner wall of the outer cylinder 23 and the outer wall of the middle cylinder 21 .
In FIGS. 5 and 6 , a line X represents a central annular line of the paper making portion of the wire cloth 31 . In FIG. 5 , the air nozzles 25 are uniformly disposed along the central annular line X, whereas in FIG. 6 , the air nozzles 25 are alternately disposed with respect to the central annular line X. With these arrangements, the raw material within the stirring tank 2 is evenly stirred, whereby the formation of the paper body is improved.
A description will now be given of a method of making paper using the apparatus according the first embodiment. First, the stirring tank 2 and the paper making portion 3 are combined together as shown in FIG. 2 . When a predetermined amount of water is supplied via the water supply port 38 , the water is passed through an opening 46 to thereby be gathered inside the paper making frame 32 and between the middle cylinder 21 and the outer cylinder 23 . Further, the air is jetted out via the air nozzles 25 so as to stir the water gathered between the middle cylinder 21 and the outer cylinder 23 . In this condition, the raw material diluted to a predetermined concentration is fed from the raw-material feeding port 24 . While the stirred condition is kept even after the raw material has been fed for several ten seconds, the paper making is carried out. Then, moisture component (including moisture component contained in the raw material) is sucked from a suction port 33 and discharged. Thus, a paper body is made on the wire cloth 31 .
[Second Embodiment]
A description will be given of a paper making apparatus according to a second embodiment of the invention with reference to FIGS. 7 to 12 . As shown in FIGS. 7 to 9 , a paper making apparatus 101 includes a stirring tank 102 and a paper making portion 103 . The stirring tank 102 is formed by mounting raw-material feeding ports 150 , stirring air nozzles 160 , jet nozzles 170 and an outer cylinder 112 onto an aluminum top 110 integrally formed with a middle cylinder 111 . A seal 114 is secured to the lower portion of the outer cylinder so as not to leak the raw material outside.
On the other hand, the paper making portion 103 includes a paper making frame 115 , a cover 116 and a central body 120 . The paper making frame 115 holds a wire cloth 113 and has a suction port 117 . The cover 116 collects moisture component such as the raw material caused to overflow outside from the paper making frame 115 . The central body 120 has an opening 121 communicating with the suction port 117 . Reference numeral 118 denotes a discharge port of the cover 116 .
As shown in FIG. 7 , the raw-material feeding ports 150 and the air nozzles 160 are arranged equally on the annular wire cloth. With this arrangement, the raw material can equally be fed within the stirring tank and the concentration of the raw material within the stirring tank can also be equalized immediately before the operation of making paper is performed.
FIGS. 10 and 11 are views showing an arrangement of the raw-material feeding ports when viewed the paper making portion of the wire cloth 113 from the above; FIG. 10 illustrates as shown in FIGS. 7 and 8 the raw-material feeding ports that are equally arranged on the central annual line X of the paper making portion of the wire cloth 113 ; and FIG. 11 illustrates the raw-material feeding ports that are alternately arranged with respect to the central annular line X.
A description will now be given of a method of making paper using the apparatus according to the second embodiment of the invention. First, the stirring tank 102 and the paper making portion 103 are combined together as shown in FIG. 8 . ( FIG. 12 shows a separated condition. Incidentally, although FIG. 8 shows the sectional view taken along the line VIII—VIII of FIG. 7 , FIG. 12 shows a sectional view taken along the line XII—XII of FIG. 7 ). When a predetermined amount of water is supplied via a water supply port 122 to be gathered inside the paper making frame 115 and between the middle cylinder 111 and the outer cylinder 112 . Further, air is jetted via the air nozzles 160 so as to stir the water gathered between the middle cylinder 111 and the outer cylinder 112 .
In this condition, the raw material diluted to a predetermined concentration is fed from the raw-material feeding ports 150 . The stirred condition is kept even after the raw material has been fed for 30 seconds, and then, the paper making is carried out. Moisture component (including moisture component containing the raw material) is sucked from a suction port 117 and discharged. Thus, a paper body is made on the wire cloth 113 . The operation of making paper may be performed while the stirred condition is maintained or after the stirred condition is stopped.
FIG. 12 shows a condition that the stirring tank 102 and the paper making portion 103 in the paper making apparatus 111 are separated and further the stirring tank 102 is cleansed. The cleansing is carried out by jetting the water in the stirring tank 102 via the air nozzles 170 . The air nozzle 170 is installed in a plurality of places and the cleansing is carried out as a separate step separately from the paper making portion 103 .
[Third Embodiment]
A description will be given of a paper making apparatus according to a third embodiment of the invention with reference to FIGS. 13 and 14 . The third embodiment is different from the second one in that raw-material feeding ports 151 are provided on the sides of the middle cylinder 111 . The basic structure of the third embodiment is similar to what is shown in FIGS. 13 and 14 , and the constitutional elements identical with those of the second embodiment are given by like reference numerals. In the second embodiment of the invention shown in FIGS. 13 and 14 , as the raw-material feeding ports 150 , the air nozzles 160 and the jet water nozzles 170 are fitted to the top plate 110 , the space of the top is narrowed. In case where the diameter of the paper body to be made is large, there develops no problem, but in case where the diameter thereof is small, however, the installation area of such a top plate would cause a serious problem.
The apparatus structured according to the third embodiment of the invention can solve any problem of the sort mentioned above. Further, since the number of raw-material feeding ports 151 and air nozzles 160 can be increased, the concentration of raw material is uniformed further. Incidentally, the positions of the raw-material feeding ports may be above or below the water level Y in the stirring tank 102 .
Further, an inclination 152 directed upward from each raw-material feeding port 151 is formed such that no raw material is left on the bottom surface of the middle cylinder 111 . In addition, the raw-material feeding port 151 is also inclined so as to match with the inclination 152 .
[Fourth Embodiment]
A description will be given of a paper making apparatus according to a fourth embodiment of the invention with reference to FIGS. 15 and 16 . The constitutional elements identical with those of FIGS. 7 and 9 are given by like reference numerals. The fourth embodiment is different from the first and second embodiments in that the stirring air nozzles are not fitted to the top plate, but air is jetted from air jet holes 161 defined to the middle cylinder 111 . The rest of the formation of this embodiment of the invention is similar to what is shown in the second embodiment thereof.
Although not shown, the stirring tank may be cleansed by jetting the water from the holes bored in the middle cylinder.
[Fifth Embodiment]
A description will be given of a paper making apparatus according to a fifth embodiment of the invention with reference to FIGS. 17 and 18 . In this embodiment, the front end 153 of each raw-material feeding port 150 is directed to the outer peripheral face of the middle cylinder 111 and the fed raw material is flown along the outer peripheral face of the middle cylinder 111 . Further, the lower end of the middle cylinder 111 is formed in a conical surface 119 and with this arrangement, even though only one raw-material feeding port is provided, the raw material moves down on the outer peripheral face of the middle cylinder 111 and together with the conical surface at its lower end, the raw material is uniformly supplied onto the wire cloth 113 .
[Sixth Embodiment]
A description will be given of a paper making apparatus according to a sixth embodiment of the invention with reference to FIG. 19 . In this embodiment, the surface of the central body 120 is formed in a substantially conical shape, and the raw-material feeding port 150 is disposed above the apex of the cone.
With this arrangement, the raw material is caused to flow in the whole peripheral direction along the conical surface 154 , so that the raw material is uniformly supplied onto the wire cloth 113 .
According to the present invention, the paper making method and apparatus are thus arranged, it is possible to obtain the discontinuous paper body with an excellent paper formation.
While only certain embodiments of the invention have been specifically described herein, it will apparent that numerous modifications may be made thereto without departing from the spirit and scope of the invention. | An apparatus for making paper includes a stirring tank and a paper making portion. The stirring tank includes: an outer cylinder; a middle cylinder disposed concentrically with the outer cylinder; a raw-material feeding port for feeding raw-material into said stirring tank; a stirring mechanisms; and a top plate for holding the outer and middle cylinders in a predetermined position. The paper making portion is installed below the stirring tank and includes: a wire cloth and a paper making frame having an opening for holding said wire cloth, and the opening is connected to a suction unit. The stirring mechanisms are uniformly disposed above the wire cloth. In addition, a plurality of raw-material feeding ports are uniformly disposed above the wire cloth. | 3 |
RELATED APPLICATIONS
This application is a continuation of application Ser. No. 11/430,347, filed May 9, 2006 now U.S. Pat. No. 7,500,762, which application is a continuation-in-part of application Ser. No. 10/750,391, filed Dec. 31, 2003, now U.S. Pat. No. 7,070,303 and claims priority under 35 U.S.C. §120 therefrom.
FIELD OF THE INVENTION
The present invention relates indoor lighting with controlled uptight capability.
BACKGROUND OF THE INVENTION
In order to make a large area visually comfortable, downlight fixtures often include some uptight capabilities, to reduce the “cave” effect caused by ceiling fixtures being too intense for the viewer to see the ceiling beyond the fixtures. The cave effect causes a glare-filled, enclosed effect, which increases eyestrain.
However, too much uplighting is inefficient and wasteful, not reflecting a large portion of emitted light back to the space below the fixture.
To provide uptight, it is known to have an open top, which wastes light usage, as much of the light is not reflected back to the space below the fixture. In addition, in general, however, lamp fixtures with open tops have a susceptibility to dirt accumulation.
Among related patents include U.S. Pat. No. 2,281,377 of Ohm, which has a slanted transparent/translucent wall but no reflector, which does not control uptight to a preferable maximum of 5-19% (by bent and concave angles of the reflector). Ohm's wall 13 is convex, so most light is not controlled. If a fixture were made similar to that of Ohm '377, wherein it would be fabricated without the lens, the fluorescent lamps would extend beyond the plane of the side of the fixture, allowing for excessive dirt accumulation thereon. Furthermore, if one would make a fixture similar to that of Ohm '377 with a non-translucent wall, the fixture efficiency would be greatly diminished. In addition, the lack of a photometrically designed reflector would diminish the obtainable efficiency of the fixture.
U.S. Pat. No. 2,534,182 of Schwartz has different angles for reflectors 31, 32, 33 that don't control uplighting. Their rounded lenses are not as efficient as using a flat lens.
In U.S. Pat. No. 2,548,500 of Sachs, the position of the reflector 15 beneath the fluorescent lamp tubes causes 50% of light up and 50% down, not a preferable controlled 5-19% as uptight. Also, if one removes the item 15 of Sachs, one accumulates dirt within the fixture.
U.S. Pat. No. 6,428,183B1 of McAlpin gets 100 percent of light up with visual waste and needs extra upper lamps 32, 33 with separate mounts. These upper lamps are exposed and subject to dirt accumulation.
U.S. Pat. No. 2,619,583 of Baumgartner describes a fluorescent fixture with and end reflector 72 spaced from the outer edge of a vertical wall to direct a portion of the light upwardly.
U.S. Pat. No. 6,210,018 of Kassay describes an angled V-shaped lighting fixture having a seven-sided polygonal fastening bracket with angled bottom edges engaging the V-shaped top surface of the angled fixture.
U.S. Pat. No. 5,806,967 of Soorus is mainly a V-shaped uptight fixture open at top, so dirt will invariably accumulate therein.
U.S. Pat. No. 2,545,058 of Walsh has an open top with susceptibility to dirt accumulation. Walsh is mainly uptight only as in FIG. 10 therein.
U.S. Pat. No. 2,474,341 of Wince doesn't have a reflector.
U.S. Pat. No. 2,348,930 of Shepmoes has a V-shape end view configuration of lamp fixtures. Downward light is less than 70%.
U.S. Pat. No. 2,327,230 of Weber is only concerned with access removal of the lens portion 27. Lighting inefficiency is similar to Shepnoes.
U.S. Pat. No. 2,320,829 of Naysmith and U.S. Pat. No. 2,323,002 of Baker both describe V-shaped arrangement of lamps, which does not control uptight.
Therefore, there is a need to provide a fluorescent lamp fixture which controls uptight to a desirable level, without wasting excess light, while significantly reducing an undesirable cave effect and without the tendency to accumulate dirt within the fixture.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide a fluorescent lamp fixture which controls uptight to a desirable level, without wasting excess light, while significantly reduces an undesirable cave effect and without the tendency to accumulate dirt within the fixture.
It is a further object of the present invention to provide labor saving features to install fluorescent lamp fixtures rapidly where applicable.
SUMMARY OF THE INVENTION
In keeping with these objects and others, which may become apparent, the fixtures of this invention accommodate straight fluorescent tube lamps of a variety of lengths and electrical design, for example popular four foot sizes. These fixtures have a full upper housing protecting all lamps from the accumulation of dust and debris while providing a controlled amount (5 to 19%) of total light output to uplighting, thereby lighting ceiling and wall areas above the fixture, to negate the so-called “cave effect”. The percentage range of 5 to 19 percent of total uplighting is controlled relative to the quantity of lamps utilized, the angle of the reflector and the height of the outside section of the fixture, which also impacts the angle of the outboard reflector.
The fixtures of this invention have a central section (from an end view) aimed directly below the fixture with lamp or lamps within a concave reflector or reflectors. Wing sections at an oblique angle extend sideways from the central section, carrying their own lamps and reflectors with totally or largely open distal ends, thereby accommodating uplighting in a controlled fashion. The uplighting provided is at an oblique angle from the fixture, as contrasted from prior-art fixtures with dedicated uptight lamps, or direct vertical upward lenses or windows, which would reflect uptight directly down from the ceiling surface.
These lighting fixtures preferably incorporate a trapezoidal pendant bracket, which accurately positions the fixture with respect to a pendant pipe and prevents any tendency of the fixture from deviating from orthogonal orientation. However, the pendant bracket/stabilizer of the present invention is usable on any type of suspended light fixture, to stabilize the fixture in place.
By “pendant pipe” it is assumed that the vertically and longitudinally pipe is either a hollow conduit having electrical wiring therein or a solid rod having electrical wiring adjacent thereto.
In one embodiment the fixture has no lens and the oblique housing sides are shortened to accommodate uplighting. In a second embodiment, a high efficiency lens is used for downlighting. Then the oblique housing sides are fitted with windows also, which are glazed with flat high efficiency lens panels to accommodate uplighting. Each of these embodiments can accommodate a variety of lamp configurations ranging from three to eight fluorescent lamps per fixture.
A trapezoidal pendant bracket/stabilizer allows the fixture to be stem hung from a pipe, such as a ¾ inch galvanized conduit stem, creating a very strong and rigid installation. This is used for gymnasiums or other locations where impact is an issue. It also creates a clean aesthetically pleasing installation. This takes some of the stress off of the pipe connection at the top of the fixture, negating any torque if the fixture is hit in anyway. The impact is taken by the points of attachment of the pendant stabilizer. It also suspends the fixture level to the floor. The bracket has a screw which when tightened tightens the fit around the stem
While the pendant bracket/stabilizer and pendant pipe allow a fixture to be stem hung from a ¾ inch galvanized conduit stem creating a very strong and rigid installation, where impact resistance is not a factor, a toggle hanger of this invention can be used for a more rapid installation. The toggle hanger is installed at the top of the pendant pipe allowing the fixture to be quickly attached to a an eye bolt at ceiling level by just inserting a toggle bolt through both eye bolt and toggle hanger mounting flange and tightening.
The toggle hanger is an extension of the pendant bracket/stabilizer system. Because it is installed on the top of the stem that goes through the pendant bracket/stabilizer, it allows for a quick installation where an eye bolt is already existing/or will be installed at the ceiling. The installer installs the fixture by just inserting the toggle through the eye bolt and tightening, eliminating the need for an expensive connection point at the ceiling and streamlining the installation to save labor. The unit is designed to support the weight through the two sides of the toggle hanger and centers the hang point to directly above the stem to guarantee a level hang of the fixture. The toggle hanger's best feature is that it allows for very rapid installations.
A second alternative mounting feature is the cost-saving quick bracket™ of this invention which replaces both the pendant bracket/stabilizer and the pendant pipe. The quick bracket™ has the general trapezoidal shape of the pendant bracket/stabilizer, but it is sized vertically to place the fixture at the desired height from the ceiling, for example, lengths from 18 inches to 48 inches are available. The top of the quick bracket™ can be used with an existing threaded rod, a new threaded rod, or a hook can be installed to couple to an existing eye bolt. An optional removable handle is used to streamline the installation.
In the second alternative embodiment, the bracket, like the pendant bracket/stabilizer, also guarantees that the fixture suspends level to the floor due to the spread of the points of attachment and the width of the material. It is an economy hanging system that does not require a stem, thereby eliminating several costly components in the hanging of the fixture. It also allows for a rapid installation. The top of the bracket can be used with an existing threaded rod when replacing existing fixtures or with the installation of a new threaded rod. A hook can also be fastened to the top of the bracket to allow for rapid installation where an eye bolt is already existing (retrofit of existing lighting system) or will be installed. The handle is totally portable and goes from fixture to fixture to allow for ease of handling and ease of holding while installing it. This bracket can come in a plurality of sizes, in lengths from 18 inches to 48 inches.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
FIG. 1 is a Perspective view of a fluorescent lamp fixture of this invention with no lens;
FIG. 2 is a Perspective view of a fluorescent lamp fixture of a second embodiment of this invention incorporating lenses;
FIG. 3 is a Top plan view of a fluorescent lamp fixture of this invention (shown with lenses);
FIG. 4 is a Side elevational view of the fluorescent lamp fixture of FIG. 3 ;
FIG. 5 is an End view of the fluorescent lamp fixture of FIG. 3 ;
FIG. 5A is a close-up detail side view showing the reflectance of the light rays of fluorescent lamps of the fluorescent lamp fixture of this invention, due to the angle and arc of the reflector having an oblique portion and an arcuate portion;
FIG. 5B is a close-up detail side view showing the reflectance of the light rays of fluorescent lamps due to the angle and arc of another embodiment for the reflector having small arcuate concave portion, an oblique portion and an inner arcuate concave portion;
FIG. 6 is an End view of a 3-lamp configuration of a fluorescent lamp fixture of this invention;
FIG. 7 is an End view of a 4-lamp configuration of a fluorescent lamp fixture of this invention;
FIG. 8 is an End view of a 5-lamp configuration of a fluorescent lamp fixture of this invention, also indicating geometric features permitting a controlled amount of uplighting;
FIG. 9 is an End view of a 6-lamp configuration of a fluorescent lamp fixture of this invention;
FIG. 10 is an End view of an 8-lamp configuration of a fluorescent lamp fixture of this invention;
FIG. 11 is a perspective view of a toggle hanger of this invention showing attachments to a pendant pipe at the bottom and an eyebolt at the top;
FIG. 12 is a perspective view of the toggle hanger of FIG. 11 attached to a lighting fixture;
FIG. 13 is a perspective view of a quick bracket™ of this invention attached to a lighting fixture and also showing the removable mounting handle;
FIG. 14 is a front elevation of the quick bracket™ of FIG. 13 ; and,
FIG. 15 is a side elevation of the quick bracket™ of FIG. 13 showing one of the slotted holes for attachment of the mounting handle.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the first embodiment of this invention, wherein fixture 1 uses no lenses. Fixture 1 has six straight fluorescent tubes 4 within housing 2 with shortened oblique walls 3 . Central concave reflector 6 is aimed straight down while side reflectors 5 are angled obliquely and have no curved section (or a very truncated one) at their distal ends. Reflector surface finish can vary, however a white finish, a specular reflector, or an enhanced specular reflector surface with 95% reflectivity are currently offered.
Pendant pipe 11 is used to attach fixture 1 to a ceiling structure; it also carries wiring within. It is mounted in hub 8 and is located accurately by trapezoidal pendant bracket 10 and secured by pendant screw 12 . However, pendant bracket 10 is usable on any type of suspended light fixture, to stabilize the fixture in place.
In a second embodiment, fixture 20 of FIG. 2 has housing 21 with full oblique walls 22 . Walls 22 have three rectangular windows 24 with flat high efficiency lenses to permit a controlled amount of uplighting.
FIGS. 3 , 4 , and 5 present top, side and end views of fixture 20 respectively. Vent louvers 28 are used to permit air circulation for cooling of ballasts and lamps while excluding dust contamination. High efficiency downlight lens 30 covers the fluorescent tubes.
A variety of lamp configurations for the fixtures of this invention are shown in the end views of FIGS. 6-10 .
For example, FIG. 6 shows a 3-lamp fixture 40 with a single lamp 4 in central reflector 41 and a single lamp in each side reflector 42 .
FIG. 7 shows a 4-lamp fixture 50 with two lamps within central reflector 51 and single lamps within side reflectors 52 .
FIG. 8 shows a 5-lamp configuration 60 with a single lamp in central reflector 61 and two lamps in each side reflector 62 . Uplighting rays 64 are shown emanating from right side to illustrate the geometric relationships between the lamp 4 location with respect to reflector 62 , truncated end curve 63 and tube 4 surface. Reflector end 63 provides the uptight cut-off and the structural configuration of the reflectors, lamp location, oblique angle, and lamp fixture population permits design of fixtures with uptight percentage fixed as desired, preferably between 5-19% of total.
For example, FIG. 5A shows the reflectance of the light rays 64 , 65 and 66 of fluorescent lamps 4 due to the angle X and arc A of the reflector 42 . Reflector 42 has a straight oblique portion 42 a and an arcuate portion 42 b. A certain portion of rays, emitted from lamp 4 designated as rays 64 , are either emitted upward or are reflected off of portions of reflector 42 in an upward direction. Another portion of rays designated as rays 65 are emitted and directed up, but reflected down by either the straight oblique portion 42 a or the arcuate portion 42 b of reflector 42 . A third portion of rays designated as rays 66 are emitted and directed down. Therefore rays 64 are the only light rays which constitute any uplighting of light from fixture 42 . The amount of uplighting is controlled by controlling the angle X of straight oblique portion 42 a off of imaginary horizontal line H 1 and the arc A off arcuate portion 42 b, off of imaginary horizontal line H 1 . As a result, a certain percentage of light, such as, for example, 5 to 19 percent, constitutes uptight directed above imaginary horizontal line H 2 through the middle of lamp 4 , either directly upward from lamp 4 or indirectly upward from lamp 4 via reflector portions 42 a or 42 b. The remaining portion of emitted rays are either emitted indirectly downward from lamp 4 below imaginary horizontal line H 2 off of the center of lamp 4 , via reflector portions 42 a and/or 42 b, or directly downward in the form of rays 66 from lamp 4 .
FIG. 5B shows another embodiment of the reflectance of the light rays 64 , 65 and 66 of fluorescent lamps 4 due to the angle and arc of the reflector having a first arcuate concave outer portion 42 c, a second straight oblique portion 42 a and a third inner arcuate concave portion 42 b. While the preferable percentage of uplighting is 5 to 19 percent of emitted light reflected above imaginary line H 2 , that percentage of uplighting can be varied by adjusting the angle of oblique reflector portion 42 a, inner arcuate concave portion 42 b and/or outer arcuate concave portion 42 c of reflector 42 .
Besides the differences in the configuration of reflector 42 and in the variations in angle X shown in FIGS. 5A and 5B , the actual size of reflector 42 and its location (i.e. distance from) relative to lamp 4 also have a bearing on the percentage of uplighting.
FIG. 9 shows a 6-lamp design 70 with two lamps in central reflector 71 as well as in each of two side reflectors 72 . FIG. 10 shows an 8-lamp fixture 80 with two down reflectors 81 in the central section with two lamps each. oblique side reflectors 82 also have two lamps each.
While FIGS. 1 and 2 show pendant pipe 11 attached to pendant bracket/stabilizer 10 and to the lighting fixtures, the attachment at the top end is not defined. In an installation such as a gymnasium, where the fixture may be impacted, the top end is rigidly attached to a sturdy attachment, such as, for example, a ¾ inch galvanized conduit stem. The pipe end is retained by a screw; the installation insures proper leveling and is aesthetically pleasing.
However, if impact is not an issue, a more cost effective self-leveling method of attachment is possible. Toggle hanger 85 shown in FIGS. 11 and 12 easily permits attachment to a preattached ceiling mounted holder, such as an eyebolt 90 (or hook) using a toggle bolt 89 through a hole in mounting flange 87 of toggle hanger 85 . Toggle hanger 85 is an inexpensive sheet metal component with housing 86 portion, which permits attachment of the top end of pendant pipe 11 through a hole in the horizontal member and retention via a fastener, such as nut 91 . Proper leveling of fixture 93 is assured by the pivoting attachment.
A second cost effective and labor saving attachment method uses the quick bracket 95 of this invention as shown in FIGS. 13-15 . This is an economy hanger system which eliminates the need for the pendant pipe. Bracket 95 is available in stepped sizes (h=18″-48″) to accommodate a variety of hanging distances from the ceiling. The wide distance between attachment feet 96 , coupled with the wide width dimension act as a stabilizer to insure proper leveling of fixture 93 . Handle 97 is totally portable and goes from fixture to fixture to allow for ease of handling and holding during installation. Slotted holes 98 in the sides of quick bracket™ 95 permit entry of screw heads at the bottom end, but retain screws securely at the top end thereby facilitating convenient attachment and detachment of optional mounting handle 97 which has fasteners, such as screws, protruding each end. The distal end of quick bracket™ 95 accepts a threaded rod 99 as shown; alternatively, a hook can be fastened which would readily couple with a pre-installed eye bolt. The ceiling mounting hardware and labor involved is much reduced from that required for a properly installed stem hanger.
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims. | A fluorescent light fixture is suspended by a longitudinally extending trapezoidal pendant bracket/stabilizer. The trapezoidal pendant bracket/stabilizer includes a horizontally extending top brace and a pair of obliquely extending arms extending downward in opposite directions from the top brace in a trapezoidal crossection. Each obliquely extending arm has a flat, horizontally and outwardly extending attachment foot extending longitudinally along a flat top surface of the fluorescent lamp fixture, wherein each attachment foot is attached to the flat top surface of the fluorescent lamp fixture. The horizontally extending top brace is attachable to a ceiling mounted fastener, such as a toggle hanger or other downwardly extending fastener. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 62/040,086, entitled “System for Housing a Boat” and filed on Aug. 21, 2014 by inventor, Michael Mulhern.
[0002] The above cross-referenced related application is hereby incorporated by reference herein in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] None.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates principally to the field of boating, including recreational, commercial, and government/military, but can also be deployed in other fields where an object floats on bodies of water (this document will hereafter use the term “boat” to refer to any vessel or floating object that would benefit from the invention such as jet skis, wave runners, paddle boards, etc.).
[0006] 2. Brief Description of the Related Art
[0007] Among the principal challenges facing boaters is the destructive effects of marine life on boats and boat components when they are in their natural environment, water, whether salt, brackish, or fresh. Significant effort and costs are required to keeping boats clean, especially boat bottoms free of what is referred to in the industry as “foul”, the plant and algae slime and, in the case of boats that operate in salt or brackish water, marine organisms such as barnacles.
[0008] Many different systems and methods have been used over time to preserve boats, specifically boat hulls and propulsion equipment, including outdrives, propellers, trim tabs, and various other equipment outside the hull of the boat but submerged when the boat is in water. For example, boat owners often install boat lifts on personal piers or, when allowed, at a marina. A boat lift is a mechanical device that lifts a boat out of the water when the boat is not being used. Boat lists are very effective, but can be very expensive, often requiring special permits from local governing bodies, and are often unattractive, limiting and impeding often otherwise beautiful water views.
[0009] Though time-consuming and physically challenging for many, “trailering”, where a boat is hauled to and from the place of use, using a boat ramp, and is kept on a trailer on dry land when not in use, is commonly used and is an effective solution to prevent fouling. Many boat owners trailer their boats for economic reasons as well as boat slip rentals are beyond the means of many boaters. Effectively, however, trailering is limited to boats under 27 feet in length. Some over this size can be towed, but many exceed the 8½ beam (width) limit for public roads.
[0010] Because of size limitations, physical requirements, and the time required, many boats of all sizes stay in the water and are not trailered each tie they are to be used. As a result, they are housed in a rented slip in a marina or at a mooring, a permanent anchor placed within a harbor and accessible with a smaller craft (often a dingy) or via water taxi in some locations. When a boat owner has waterfront property, he/she will often install a boat lift. This is a viable option for maintaining a clean boat bottom, but requires significant investment, often requiring the installation of pilings on an existing pier (quotes for a 20,000 pound lift in the mid-Atlantic ranged from $15,000-$40,000 installed). Further, a waterfront homeowner must also install or reconfigure electric lines on the docks and must obtain permits for both the lift (sometimes requiring a variance, notification of neighbors, and hearings . . . often a lengthy and expensive process). The boat lift also reduces the ascetics of the waterfront property and usefulness of the boat while docked. Boats on a lift, with the boat bottom exposed, are an eyesore to some, particularly as compared to an often-attractive boat resting on the water. Further boat owners often enjoy entertaining on their boats, while moored at a dock. This is not possible, or at least very awkward with the boat on a lift.
[0011] On rare occasion, marinas allow boat lifts, but the investment is significant and this option largely limited to condominium marinas (where the slip is owned by the boat owner) or where marinas make the investment and charge a premium for the slip/lift. As a rule, however, most marinas prefer to avoid the cost and liability of boat lifts as well as the ascetics of having boats outside the water, which affects the waterfront view. Further, boat owners often entertain with the boat at the slip, which is not an option with the boat on a lift.
[0012] Boats that reside in water, as is almost always the case with large boats and often with smaller vessels, require regular service to prevent and limit fouling. According to industry experts, boats are used only about two percent of the time between when they're launched and hauled out. Most recreational boats sit for weeks and get used for a few hours on (some) weekends during the season. As a result, foul buildup is often significant.
[0013] Bottom painting and regular cleaning is the standard solution for any boat that resides regularly in water. With bottom painting the boat owner must periodically (one or two times a season) either remove the boat from the water and wash it down or have the boat cleaned by a diver in SCUBA gear. Regardless the owners of bottom-painted boats must periodically (usually annually) remove the boat from the water have it washed/scraped, which is a very involved and, often, expensive process and increasingly a process that has come under environmental scrutiny and tighter regulation.
[0014] Bottom paint, or antifouling paint, contains at least one biocide, an ingredient that is toxic to marine life that would otherwise cling to the boat hull. Tin was once used as the standard biocide but it has been banned because it leaves sediment that is harmful to the environment. Tributyltin, as known as TBT, was widely used until the 1980s, when it was outlawed by international convention.
[0015] Copper has more recently become the ingredient of choice as the toxin for paint. However, copper is expensive—retail price $200-$300 per gallon—plus it too has been found to cause damage to ecosystems. Copper has been banned in several European countries and in the state of Washington. Recently the state of California considered a ban on the substance as well. As a result, many expect copper-based paints to have a limited time on the market.
[0016] Because of the elements contained in bottom paint, it is generally classified as hazardous; it is widely restricted in its application and removal. Many marinas participate in “Clean Marina” program, which is rapidly becoming an industry standard. Among the elements of a clean marina are separate areas for boat cleaning, with containment provisions for run-off (run-off is recycled and cleaned rather than the old practice of allowing the residue to flow into the nearby body of water). They also require enclosed cleaning areas for stripping of bottom paint with technicians clad in haz-mat gear. It is highly likely that environmental requirements and restrictions will expand in the future, making the bottom-painting process increasingly expensive, time-consuming, and with reduced availability of qualified vendors.
[0017] Boat bottom paint and painting is already an expensive (usually annual) requirement for boat owners. In-water boats are often cleaned in water one or two times (or more for some) a season, at a cost of $100-500, depending on boat size. An annual haul out will cost about $8-10 per foot, cleaning about $5/foot, and painting about $70/foot. For a 34-foot boat, the annual cost for keeping the bottom usable is about $3000. Striping boat paint, which is also done periodically, but not annually, will cost about $6000.
[0018] This invention, to be known commercially, as the present invention is aimed at alleviating the need to paint boat bottoms and by removing the boat from water, as with a lift, but using an “outside hull” into which the boat is driven (the outside hull is larger than the vessel), is enclosed, and the water is removed from the area between the boat and the outside hull. This completely removes fouling water from contact with the boat, keeping the boat relatively clean and free of foul.
[0019] The invention provides many benefits to the boat owner, providing the hull-saving features of a boat lift in locations where lifts are not feasible.
SUMMARY OF THE INVENTION
[0020] The present invention uses an “outer hull” or “host hull,” which is opened and flooded to allow a boat to enter the inside while the outer hull is in a semi-submerged state. The invention involves closing the space once the boat is inside and pumping water from the enclosure, thereby reducing or eliminating bottom-fouling and staining water from making contact with the boat. As water is removed from the inside of the outer hull, it rises in the water until it meets the bottom of the boat that was driven into it. The invention can also involve changing buoyancy of the outer hull so that some of the water naturally flows out of the enclosure as the water is displaced by a boat, eliminating much of the fouling water from contact with the hull. The invention can also combine a change of buoyancy with a pump to remove the water.
[0021] The invention will allow the boat to remain in the water, as in a marina slip, while keeping the boat bottom dry, no longer exposed to fouling water.
[0022] The aim of the invention is to alleviate the need to regularly clean and paint the bottom of the boat by removing the boat from water, by using the “outer hull” into which the boat is driven (the outside hull may be slightly larger or because it is semi-submerged the “vee” angle of a boat hull allows a floating boat to fit inside). The water between the host hull and the boat is then removed, either using a pump or raising the outside hull through changing buoyancy, or a combination of both. This removes most, if not all, fouling water from contact with the boat, keeping the boat relatively clean and free of foul.
[0023] In a preferred embodiment, the system and method for housing a boat has an outer or host hull having a bow, a stern and an interior adapted to accommodate a hull of a boat. At the stern of the host hull is a door that can be opened or closed. In a closed position the interior of the host hull becomes water tight. A plurality of bumpers are attached to the host hull. A pump is in host hull to pump water out of the host hull when the door is closed. A portion of the outer hull adjacent the stern may be deeper than a portion of the outer hull adjacent the bow.
[0024] Recreational Boating is estimated to be more that a $50 billion (spend) market in the United States, employing close to 1 million people. There are over 12 million registered boats in the United States and at least double that number worldwide (boats without engines, principally smaller sail boats and self-propelled boats—e.g., rowboats, kayaks—do not require registration). Recreational boating has a rather high service-to-use ratio. Unlike cars, where one can travel 5,000 or even 15,000 miles without any service but gasoline, boats are regularly in need of service. As a result, the services component of the industry is significant.
[0025] Much of the servicing required for boats is a result of water-borne damage to the bottom of the boat and other parts exposed to water. The fouling of boat hulls and related beneath-the-surface parts has caused problems for water-borne vessels since man first began to use the water for navigation, commercial, and recreational purposes. While the degree of marine plant and animal buildup varies depending on a variety of factors, including water temperature (higher temperatures tend to breed higher concentrations of marine life), salinity, and location. Harbors, estuaries and similar environments, where boats tend to be moored and marinas concentrate, tend to be particularly productive breeding grounds for foul-producing marine life, as run-off from nearby land provides food on which much marine life exists. Speed of water and use of the boat also affects buildup (the more movement, water or boat, the less fouling). Regardless of location and usage, though, marine growth on objects in water in unavoidable whether fresh or salt water, making the avoidance of buildup of foul a necessary and increasingly costly task for recreational, government/military, and commercial boaters alike.
[0026] The present invention greatly reduces the exposure of most boats to fouling and the consequent damage caused by water. Recreational boats, in particular, will benefit from the invention, as they tend to move in the water much less frequently than commercial or government/military vessels. Recreational boats are used, on average, about 2% of the time during the season, equating to about three hours a week. Many boats sit in marinas and at docks for weeks on end, especially in marinas housing boats of out-of-town owners, allowing for significant foul build up during the hot summer months.
[0027] The present invention is a solution that provides the protection benefits of a boat lift, without the severe limitations inherent in lifts, namely, restrictions, whether by statute, home owner association, or marina restrictions, lifts almost always have to be placed on a dock at the property of the boat owner. Most boat owners do not live on waterfront property. Even for those who do, in many cases restrictions limit their use and the cost of permits and installation can be excessive.
[0028] The present invention can be used at a personal waterfront location, in marinas, both public and private, and can be attached to a mooring ball where mooring of boats is allowed.
[0029] The present invention provides benefits beyond protecting the hull and underwater components of the boat. In the situation where a boat owner has the option of installation a boat lift, the present invention is expected to be more cost effective and it provides both improved aesthetics and usefulness. The boat is not raised above a floating position, as a result, it does not block the waterfront view nearly as much as on a lift and the bottom of the boat, generally an ugly part of the boat, is not exposed, as with a boat lift. Further many boat owners enjoy spending time on a boat floating at a dock. Boat owners often entertain friends, read, sleep, and just enjoy the view and rocking motion of a boat in the water. This is not an attractive option with a boat on a lift.
[0030] For the vast majority of boat owners who do not trailer their boats, the reduction a bottom foul is by far the biggest benefit. Those who keep their boats, and a present invention, at a personal pier or in a marina do can expect further benefit. The present invention will be tied to the marina posts, just as a boat is when it is docked. With the present invention, the boater simply has to steer the boat into the present invention; this makes docking much easier, without requiring lines and coordination of others on the boat to assist with docking (lines are not required as the boat fits snugly into the present invention and the present invention itself is already appropriately tethered to the dock and/or pilings). In this manner, the present invention is similar to a lift, where boaters simply drive between posts to place the boat on the submerged lift. No lines are required and docking a far easier, regardless of wind or tide.
[0031] For a boat owner in a marina, the present invention retains the benefit of being able to work on the boat, to entertain on the boat, or simply to enjoy “hanging out” on the boat as it floats in the water.
[0032] Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating a preferable embodiments and implementations. The present invention is also capable of other and different embodiments and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description and the accompanying drawings, in which:
[0034] FIG. 1 is a top view of a preferred embodiment of an outer or host hull of the present invention with the stern door open and water inside the outer hull, such that the outer hull is in a semi-submerged position.
[0035] FIG. 2 is a top view of a preferred embodiment of an outer hull of the present invention with the door closed and water having been pumped out so that the hull is dry on the inside. There is no boat in this depiction.
[0036] FIG. 3 is a side view of the outer hull as shown in FIG. 1 , with the door open and the outer hull semi-submerged.
[0037] FIG. 4 is a side view of the outer hull as shown in FIG. 2 with the door closed and water pumped out. The outer hull is floating higher (the water line is lower on the hull) than in FIG. 3 because water has been removed, making the outer hull more buoyant.
[0038] FIG. 5 is a top view of a preferred embodiment of an outer hull of the present invention as shown in FIG. 1 with a boat inside the outer hull. There is water inside the hull, surrounding the boat.
[0039] FIG. 6 is a top view of the outer hull as in FIG. 5 with the door closed with a boat inside and water pumped out.
[0040] FIG. 7 is a side view of a preferred embodiment of the present invention, similar to FIG. 3 , but with a boat having entered the present invention. The boat floats inside the outer hull on its own as the outer hull is still semi-submerged, filled with water.
[0041] FIG. 8 is a side view of a preferred embodiment of the present invention with a boat inside the outer hull with the door closed and water pumped out. In this case, the outer hull has risen meeting the hull of the boat (note the water line is lower on the present invention than in FIG. 7 when it is still semi-submerged), which is no longer floating on water inside the present invention.
[0042] FIG. 9A is a side view of a first alternate preferred embodiment of the invention for potential use with a boat with an outboard engine. In this version, there is a smaller-than-normal transom on the stern of the hull which, along with appropriately placed buoyancy, allows the outer hull to fill with water on the rear of the hull only, putting the outer hull at an angle when it is semi-submerged.
[0043] FIG. 9B illustrates the outboard version as in FIG. 9A in a level position with the water pumped out.
[0044] FIG. 10A is a side view of a second alternate preferred embodiment of the invention for potential use with a boat with an outboard engine. In this version, there is a smaller-than-normal transom on the stern of the hull which, along with appropriately placed buoyancy, allows the outer hull to fill with water on the rear of the hull only, putting the outer hull at an angle when it is semi-submerged.
[0045] FIG. 10B illustrates the outboard version as in FIG. 10A in a level position with the water pumped out.
[0046] FIG. 11 is a top view the first alternate embodiment shown in FIGS. 9A and 9B , submerged and water flowing across the transom as shown in FIG. 9A .
[0047] FIG. 12 is a top view the first alternate embodiment shown in FIGS. 9A and 9B with the buoyancy adjusted and water removed as shown in FIG. 9B . The water is no longer inside the stern of the present invention.
[0048] FIG. 13A illustrates the first alternate embodiment of the present invention, as shown in FIGS. 9A , 9 B, 11 and 12 , from the rear view with the present invention in a semi-submerged position. This shows the water line right at the transom on the stern of the invention.
[0049] FIG. 13B shows a rear view of the first alternate embodiment shown in FIG. 13A , with the water removed and the water line below the transom on the stern of the present invention.
[0050] FIG. 14A illustrates the second alternate embodiment of the present invention, as shown in FIGS. 10A and 10B from the rear view with the present invention in a semi-submerged position. This shows the water line right at the transom on the stern of the invention.
[0051] FIG. 14B shows a rear view of the second alternate embodiment shown in FIG. 14A , with the water removed and the water line below the transom on the stern of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] The preferred embodiments of the inventions are described with reference to the drawings. The present invention is believed to offer a viable, cost-effective, and environmentally friendly alternative to painting and ongoing cleaning, scraping, and repainting of a boat's hull and under-water mechanical components. This represents what is expected to be a less expensive and more atheistically pleasing alternative to boat lifts at private residents and marinas. Further, by reducing dramatically the need for bottom painting and the consequent damaging chemical and processes that it entails, the present invention is expected to be far friendlier to the environment than that current state of the art.
[0053] The introduction of a present invention to the boating industry is expected to provide a viable alternative to boat lifts and to the time-consuming, expensive, and environmentally destructive bottom painting process currently used by many boaters. The key element of the invention is the introduction of a solid outer or host hull into which the boat is floated. Once the boat is inside the outer hull, the outer hull is closed off and the boat floats within outer hull. The outer hull is then drained of water, through displacement and via pump, which raises the outer hull to the point where the inside of the outer hull (or rails or bumpers within the outer hull) and the hull of the boat meet. In effect the two become a single floating object, raising and falling together with the tides and rocking back and forth together with wakes and waves. When the two are coupled, for example, touching in several places through the presence of strategically spaced bumpers (consistent with the shape of the hull of the boat), the structural integrity of the outer hull is supported by the integrity of the boat inside. As a result, the outer hull does not require significant reinforcement, including stringers (structural supports within a boats hull). When it's not supporting a boat, the present invention is light and floats on its own. When a boat is inside, the two are attached as one and the boat supports the outer hull.
[0054] FIGS. 1-14B illustrate the present invention from different angles, with and without a boat inside and in various states of open and filled with water and closed with the water pumped out.
[0055] FIG. 1 is a view from above the present invention. It shows the outer hull 100 , with a body 110 and a transom (the stern or back of the boat) 120 fully open in the water. The body 110 has a lower portion 112 for accommodating a propeller assembly. The opening at the stern of the outer hull 100 is made possible through the use of one or more hinges 130 (only one is showing because others are directly beneath so can not be seen from this perspective). In these diagrams, the squiggly lines represent water; these are an important part of each illustration as they illustrate when the outer hull is semi-submerged; their absence inside the present invention indicates the water has been pumped out. In FIG. 1 the water is both outside and inside the present invention. In this condition, the outer hull 100 is semi-submerged (there is water inside the hull but it remains adequately buoyant that it does not sink). With the door 120 open and water inside, the body 110 is ready to receive a boat, which will be floating in through the open door 120 . The boat's position in the body 110 is dictated by bumpers 150 , 160 placed strategically along the inside of the outer hull, including likely larger bumpers or rails 150 on the lower portion or bottom of the body 110 . These bumpers 150 , 160 are sized and positioned according to the size and shape of the boat to be kept in the outer hull 100 . Throughout these drawings, a solid bumper outlined with a dashed line is meant to convey the bumper is below the water line 200 . Similarly, where lines of the outer hull 1 are dashes, this is meant to represent the parts of the present invention that are below the water line 200 . In FIG. 2 , the door 120 at the stern is closed and the water is pumped out of the outer hull 100 using pump 140 .
[0056] This process is also illustrated in FIGS. 3-4 from a view from the side. Importantly, this shows the water line 200 , which illustrates how the present invention is semi-submerged with a higher water line 200 in FIG. 3 versus a water line 200 that is lower in FIG. 4 (of course, the water is not lower, but rather the present invention is floating higher in the water). The process of pumping the water out of the outer hull 100 using the pump 140 , or other known means, raises the outer hull as it becomes less dense, on average, and more buoyant in the water.
[0057] A boater pulls his/her boat 600 into the outer hull 100 as shown in FIG. 5 and FIG. 7 with the door 120 open. The boat 600 is positioned inside the outer hull 100 by the bumpers 150 , 160 that line the inside (boat facing) side of the body 110 . Using for example, a mechanical device (not shown) such as pulleys or gears or simply by hand, the boater closes the door 120 , making the outer hull 100 watertight, and turns on the pump 140 , removing the water that had flooded the outer hull 100 when the door 120 was open.
[0058] As the water is removed, the body 110 of the outer hull 100 raises such that the bumpers 150 , 160 meet the hull of the boat 160 as illustrated in FIG. 6 and FIG. 8 . As shown in these diagrams, the water is no longer inside the outer hull 100 and no longer separates the bumpers 150 , 160 from the boat 600 . The boat 600 is no longer floating inside the outer hull 100 but rather is coupled with the outer hull through the bumpers 150 , 160 and they are both floating as a single unit.
[0059] The outer hull 100 can be attached to whatever medium the boat owner had used previously when he/she kept a boat in the water. As an example, FIGS. 5 and 6 illustrate how a present invention might be positioned in at a marina or a private dock. The present invention is attached in four places to pilings 510 on the dock 520 and outside the dock and tethered to the pilings 510 using boats lines (ropes) 512 . The outer hull 100 is fastened to a dock 520 or marina in much the same manner as a boat would be floating in a boat slip, with the exception of the stern lines do not cross as that would impede entry and exit to and from the present invention.
[0060] A further feature of the invention is a deeper hull 112 at the stern of the body 110 to allow for machinery, primarily propellers, to be placed within the outer hull without being impacted by the outer hull as the water is emptied and outer hull rises to meet the boat. This feature is illustrated in FIGS. 7 and 8 , where the body 110 is slightly deeper in the stern portion 112 , allowing the shaft and propeller of the boat 600 , known as the screw, on an inboard (as depicted) or the outdrive for an inboard/outboard (I/O) engine, which would similarly extend below the bottom of the boat.
[0061] Outboard engines, which extend beyond the stern of the boat, attached to the transom, provide an opportunity for alternative embodiments for the present invention as shown in FIGS. 9-14B . While they can be housed in the traditional model, with an opening and closing door, as depicted in FIG. 1-8 , an outboard engine can use an alternative model.
[0062] FIGS. 9A-9B and 11 - 12 illustrate an alternative method of the invention. The principle of flooding the present invention, bringing a boat inside, and pumping out water is the same as in the prior discussion. Nevertheless, the outboard version does not have a door. Rather is has a transom 990 that is just above the water line when the outer hull 900 is drained of water (transoms on outboard engine boats are ordinarily 8 - 24 ″ above the water). The outboard version of the invention involves flooding the stern of the outer hull only. Either through weights 970 , which when moved to the stern of the out hull 900 causes the transom 990 to sink below the water line which allows water to flood into the stern of the body 910 or through openings 980 placed below the waterline in the stern of the boat. In FIGS. 9A and 9B these openings and open/shut valves 980 are placed on the sides of the outer hull, near the transom. They can be placed elsewhere, but they operate it the same manner. Opening the valves allows water to flow into the hull, flooding the stern. Those of skill in the art will understand that other arrangements may be used with the present invention. Through adjustments in buoyancy, where the bow is more buoyant than the stern, the present invention sinks to a greater degree in the stern. As a result, the when semi-submerged, the present invention is higher in the front (bow), floating at an angle to the water line (see FIG. 9A ).
[0063] With the present invention in this position, water will flow back and forth across the transom 990 as it is at or slightly below the water line. To enter the present invention, the boater simply noses the boat's bow into the transom thereby pushing the transom further beneath the surface. The boat can proceed inside the present invention with the stern of the present invention sinking further to accommodate the boat's hull. As the boat moves further, appropriately placed bumpers 960 will force the bow down, putting slight pressure on the stern to rise. Once the hull of the boat clears the transom 990 , the pressure of the bow being pushed down will naturally make the stern of the body 910 rise such that the transom 990 is again slightly above the water line 200 . At this point, the pump 940 can be engaged removing water from the outer hull 900 and it will rise to meet the hull of the boat.
[0064] As with the inboard/I/O version, the bumpers 960 will be strategically placed according to the shaped of the boat's hull and any mechanical equipment on the bottom and lower stern of the boat. While rails are not shown in FIGS. 9A and 9B it will be apparent to those of skill in the art that rails or the like may be used in this embodiment as well.
[0065] A second alternate embodiment is shown in FIGS. 10A-10B and 13 A- 13 B where a movable transom 992 and mechanical element 994 for raising the moveable transom 992 are added to assist in raising the outer hull in the water.
[0066] These versions of the invention are likely the most common uses for recreational boating and can be used for commercial, government, military and other purposes where a boat (or any other waterborne object) would benefit from device that protects it from water. However, other versions are possible.
[0067] Using the same principle being claimed, alternative versions can be created. For example, a sailboat version with a much deeper hull to accommodate the deeper keel or centerboard, and with a much deeper door, can be developed using the same principle.
[0068] Similarly, multi-hulled vessels can use a version of the present invention developed for this purpose, such as a double outer hull to be used for a pontoon boat.
[0069] The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein. | A system and method for housing a boat. The system has an outer or host hull having a bow, a stern and an interior adapted to accommodate a hull of a boat. At the stern of the host hull is a door that can be opened or closed. In a closed position the interior of the host hull becomes water tight. A plurality of bumpers are attached to the host hull. A pump is in host hull to pump water out of the host hull when the door is closed. A portion of the outer hull adjacent the stern may be deeper than a portion of the outer hull adjacent the bow. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
A container lid with integral scoop, and an open-mouthed container, the lid fitting onto the container mouth with the scoop inside the container. The lid with integral scoop is especially intended for usage in removal of dog droppings, i.e. dog feces, from the urban environment by manual manipulation of the lid to scoop up the dog feces, after which the lid is fitted over the open mouth of a used standard steel can such as a used and empty soup, vegetable or dog food can, with the scoop and dog feces inside the can, after which the can containing the removed dog feces may be suitably discarded.
2. Description of the Prior Art
The problem of dog feces deposited on sidewalks, walkways, in parks, etc., is ubiquitous, especially in urban areas. Although most cities and municipalities have adopted ordinances requiring the dog owner to curb his dog, this law is seldom observed in many areas and enforcement of the law is difficult since law enforcement officers are, in many instances, devoting their time to more serious crimes. Thus, deposited dog feces is prevalent in many urban areas. Besides being unsightly and unsanitary, typically soiling the shoes of unwary pedestrians, deposited dog feces is a serious health hazard to small children who often play with and even ingest the dog feces due to natural instinct and curiosity, thinking that it is food. This can lead to serious illness in the child such as worms or digestive upsets.
In addition, it is well known that flies, such as the common housefly, the blue-tailed fly and the horsefly, exhibit a natural predilection, a certain propensity and an unfortunate proclivity to swarm about, light on, and crawl over deposited dog feces. Flies are naturally attracted and drawn to deposited dog feces for several reasons, inter alia, the natural biological urge to deposit eggs which mature into maggots on the dog feces.
In any event, flies also endeavor to gain access to the premises of humans, wherein they proceed to land on and crawl over food, personal possessions and property such as kitchen utensils, and even to crawl on and bite human beings, especially small children, toddlers and infants. Thus, the flies tend to communicate and spread disease, and to soil the interior of dwellings, by the transmission of bacteria from the dog droppings into the presence of humans in houses and apartments, principally because the legs of flies terminate with porous and moist feet, to which dog feces naturally tends to cling. The present container and container lid clearly functions to preclude such unhealthy and unsanitary spread of dog feces and disease into the lives of humans, by eliminating the deposited dog feces from sidewalks, curbs, streets, parks, etc. in urban areas and suburban areas.
Other instances where a small, portable manual scoop is usable include diverse occupations such as park department employees, e.g. persons assigned to removal of leaves and small twigs from the ground, factory workers, homeowners, military personnel assigned to policing an area such as in the vicinity of the barracks, etc. In general, the present container and container lid provides a cheap and disposable means for the collection of refuse such as machine shop waste, e.g. nuts and bolts, glue, sawdust, waste such as suet generated during the slaughtering and/or butchering of animals, vegetable waste in canneries and packing plants, dog feces, household kitchen cleanup, engine grease, and so forth, or for the inexpensive storage of diverse collected materials.
With specific regard to dog drop scoops per se, a body of prior art has been developed in recent years because of the need for an inexpensive, workable device to accomplish the elimination of dog droppings, i.e. dog feces, from the urban environment, and also in response to the more stringent laws relative to pollution which have been enacted in recent years. The urging of environmentalists in this regard is well known, and there is a continuing debate between such groups and those who have dogs as pets or for security reasons, i.e. as protection against intrusion in the dwelling by criminals intent on burglary, robbery or even rape or murder. This is especially true in certain urban areas, where the vast majority of perceptive people keep one or more guard dogs in their dwellings.
Among the many prior art patents relating to the highly developed art of dog drop scoops which may be mentioned are U.S. Pat. Nos. 3,716,263; 3,733,098; 3,786,780; 3,819,220; 3,841,686; 3,912,316; 4,010,970 and 4,014,584.
Another prior art approach to the problem of dog feces entails the provision of a harness or framework including a plastic bag, which is mounted over the anal region of a small animal, such as a dog, so that when the animal has a bowel movement and defecates, the feces is caught in the bag which is disposable. Prior art relative to this approach to the solution of the problem of dog feces includes U.S. Pat. Nos. 3,656,459; 3,786,787; 3,792,687; 3,817,217 and 3,875,903.
With regard to containers and container lids, prior art configurations include those of U.S. Pat. Nos. 3,726,447; 3,894,650; 3,905,502; 3,910,444 and 3,913,774.
SUMMARY OF THE INVENTION
1. Purposes of the Invention
It is an object of the present invention to provide an improved container and container lid.
Another object is to provide an improved container lid with integral scoop.
A further object is to provide an improved article of manufacture for the removal and elimination of dog feces from the urban environment.
An additional object is to provide an inexpensive container lid with integral scoop for the transfer by manual manipulation of any solid substance such as a waste material from a surface on which it has been deposited into a container.
Still another object is to provide an improved means for removing deposited dog feces from a surface and cheaply containing the removed dog feces.
Still a further object is to provide a container and container lid with improved perimetral structure for the mounting of the lid to the container.
An object is to provide an improved container lid with integral scoop for usage with used standard steel cans.
An object is to provide a cheap and disposable means for refuse collection.
An object is to provide a container and container lid which can be used as a containing device for storage purposes or which can be disposed of, i.e. discarded, after a period of usage.
An object is to provide a container and container lid which can be suspended from its respective side or top by an integral hook which is part of the container or container lid.
An object is to utilize a previously discarded standard steel can after its primary and initial function of containing food or the like for transport to a consumer has ended.
An object is to provide a sealed sanitary container having an improved container lid, which container is suitable for disposal of refuse, e.g. dog feces, and will not easily open.
An object is to prevent flies and other parasites from infesting waste such as dog feces and possibly spreading disease.
An object is to provide a container and container lid for disposal of dog feces which can be suspended from the dog's own collar, if desired, until the actual cleanup is necessary.
These and other objects and advantages of the present invention will become evident from the description which follows.
2. Brief Description of the Invention
The present invention provides a cheap and disposable means for the collection of refuse such as dog feces, household kitchen scraps and peelings, shop waste, e.g. from a machine shop (nuts and bolts, turnings, shavings, engine grease), glue, sawdust, chips, trash, litter, etc. The invention consisting of a new configuration of container lid with integral scoop, and the container, can also be used as a containing device for storage purposes. After a period of usage, it can be disposed of, e.g. a last use containing an unsanitary material such as engine grease scooped off a surface, dog feces, etc. When used for storage, the lid or container can be suspended from the top or side by a hook means which is part of either the lid or container.
The lid alone (with integral scoop) can be used and sold, and because the scoop is molded to the lid's inside adjacent the inner protuberance, the lid can be made to fit over the upper edge of a standard steel can such as are used throughout the country for packing soups, vegetables, tuna fish, and even dog food. It is thus possible with the present invention, whether used as a whole or in part, i.e. the lid with integral scoop per se, to add more usage to a steel can that is normally thrown away after its primary purpose of holding a consumable material such as soup, vegetables, juice or even dog food is completed.
The lid with integral scoop could be manufactured in several sizes to make use of the various standard sized steel cans which are on the market and which are used to contain consumer products. The integral scoop of the lid, being adjacent the inner protuberance of the underside of the lid, is intended to fit also on the inside of whatever container the lid is fitted to; either the present new container configuration to be described infra, or the aforementioned standard steel can currently used for consumer products.
The present scoop in a preferred embodiment is intended to fit fairly closely to the side wall of the intended container, because in this manner the lid and integral molded scoop can easily be placed onto the open mouth and upper lid section of the container, because the scoop follows the side wall of the container down past what is being contained (dog feces, nuts and bolts, glue, sawdust, etc.), thereby insuring a more uniform fit to whatever container is being used.
The present lid and container can be made in small to even very large sizes, to accommodate varying disposal problems. The present invention, whether used as a complete unit (lid with integral scoop plus container), or the lid with integral molded scoop by itself, provides a sealed sanitary container suitable for disposal, which container will not open easily to inadvertently discharge the scooped-up contents. This is because the lid, when once emplaced, will not readily separate from the upper lip region of the present container or a standard steel can. Thus, one feature of the present lid with integral scoop, with or without the present container, is to prevent flies and other parasites from infesting contained waste and possibly spreading disease. When used for dog feces cleanup, the container and lid can be suspended from a molded hook on the side of the container or on the top of the lid, mounted on the pet's own collar (the owners of most dogs provide collars around the neck of their pets), until the actual cleanup is necessary.
Thus, the present lid with integral scoop is configured so that the scoop extends into the container at an angle when the lid is mounted to the container. Preferably, the scoop is perpendicular to the lid and thus parallel to the side wall of the container when the lid is emplaced on the open mouth of the container. Thus basically, the present invention brings together a disposable lid unit which is composed of a molded, e.g. plastic, self-sealing top and a disposable molded container (or standard steel can), with the top or lid designed to fit firmly onto and across the open mouth of the container.
The top or lid is molded as one piece, incorporating a hook on the center of the top, a self-sealing seal means about the perimeter of the disc-shaped lid which can be fitted to a standard steel can or to the present container configuration specifically made to fit the surfaces of the seal means. The lid or top is usually slightly hemispherical in shape and is disc-shaped, i.e. circular or round. Under the lid is a surface which is adjacent the outer perimeter of the lid. This is comparable to a skirt and is somewhat longer or wider than the actual outerside of the lid, and provides for ease of fitting a standard steel can or the present container, to close it with scooped-up contents inside, and to provide extra sealing and anti-collapsing if a very thin walled container is used, i.e. to support the upper mouth of the container.
As discussed supra, under the lid or top is also molded the scoop which is used for picking up dog feces or other wastes of a disposable nature, to be placed in a standard steel can, e.g. a soup can, or into the present new container.
The container is molded in one piece, as is the top or lid, with integral scoop. Generally, a pliable plastic material such as polyethylene, polypropylene or polyvinyl chloride will be employed as the material of construction. The entire container is generally cylindrical in configuration; however, the bottom of the container may be slightly smaller in diameter than the top (somewhat conical). The bottom of the container may be slightly hemispherical or flat. The present container also may have an outer hook on its side wall. This hook is similar in function and performance to the hook on the lid. Either hook can, while attached to the pet's collar, remain there through most of the pet's physical movements. The intended purpose is for the pet to carry the lid and/or the lid and container as a unit through the pet's normal exercise courses; then to be easily removed to recover any litter, i.e. dog feces, the animal has made; thereafter to be placed back on the collar whereupon the pet carries the lid and container as a unit to be properly disposed of in existing refuse containers or household garbage cans.
The present invention basically includes a container lid with integral scoop generally consisting of a disc-shaped member (the lid), means about the perimeter of the disc-shaped member for securing the disc-shaped member to the circular top free edge of an open cylindrical container, and a planar scoop means. The perimetral means includes at least inner and/or outer circular protuberances on opposite sides of an annular channel in the disc-shaped member. The scoop means depends from the annular inner portion of the disc-shaped member adjacent the inner circular protuberance. Preferably, the disc-shaped member is dome shaped.
In a preferred embodiment, the lid is provided with hook means which extend from generally the center of the disc-shaped member. The hook means preferably entails the provision of two hooks aligned on a common axis of symmetry and having opposed openings.
Typically the scoop means tapers inwards and away from the inner protuberance. Preferably an annular lip extends outwards from the perimeter of the disc-shaped member. In a preferred embodiment, a rectilinear spring clip is also provided in combination with the lid. The spring clip has upper and lower lateral extensions for engagement of, respectively, the edge of the disc-shaped member and the bottom edge of a container. Also, the spring clip will usually have a twisted portion along its length for manipulation of the spring clip.
In a preferred embodiment, the container lid is combined with a container of specific and optimum configuration. The present container is an open cylindrical container having a circular top free edge about its mouth, which free edge has a circular enlargement with an inner recess and an outer protuberance. Typically, the terminal surface of the free edge of the container is flat and inclined relative to the container wall, the terminal surface extending between the inner recess and the outer protuberance. The angle of inclination of the terminal surface is generally equal to the angle of enlargement of the scoop means adjacent the inner protuberance. Generally, a hook means will extend outwards from the surface of the wall of the container.
Preferably, the scoop means will have a curved surface, and in this case typically the scoop means will be concentric with the edge of the disc-shaped member.
The device of the present invention provides several salient advantages. The elimination of the dog feces from the urban environment has a salutary effect on the appearance and sanitary conditions in the public areas, as well as preventing soiling of shoes and even preventing disease among small children. The present device is inexpensive, rugged, serviceable, portable, and is manually operated and manipulated by young and old alike. Thus, the present device serves to aid in alleviating and arresting the highly prevalent urban decay which is due in some measure to the appearance of certain urban areas, i.e. litter, trash and other objects as well as dog feces may be removed from the urban areas, thus improving the cleanliness and appearance of even the worst slum areas.
Other significant advantages of the present invention have been discussed supra; however, it should also be mentioned that the present invention allows the user to remain clean and sanitary at all times; the present article of manufacture is cheap and easy to make and can be sold to the consumer at low cost; a previously wasted item (a used standard steel can) is salvaged and performs an additional useful function; the dog carries the unit like the Saint Bernard dog of Switzerland carries sustenance for stranded travelers in the ice and snows of the Alps; the present lid and container are easy to use and lawful; the can is easily removed and disposed of; and the present invention can be utilized and used generally around the dwellings or houses of people, in factories, machine shops, etc.
The invention accordingly consists in the features of construction, combination of elements, and arrangement of parts which will be exemplified in the article of manufacture hereinafter described and of which the scope of application will be indicated in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings in which are shown several of the various possible embodiments of the invention:
FIG. 1 is a perspective view of a dog with container per se, and lid with integral scoop per se, each separately attached to the dog's collar;
FIG. 1A is an enlarged view of the container showing the suspension hook thereof attached to the dog's collar.
FIG. 2 shows the container lid with the integral molded scoop being used to remove a solid substance from a surface;
FIG. 3 shows a preferred embodiment of container, and container lid in place on the container, the lid being that of FIG. 2 after the substance has been scooped up;
FIG. 4 is a sectional elevation view taken substantially along the line 4--4 of FIG. 3;
FIG. 5 is a sectional plan view taken substantially along the line 5--5 of FIG. 3;
FIG. 6 is a detail of a portion of an embodiment of the present lid with integral scoop as mounted to a standard steel can;
FIG. 7 shows another embodiment of the present lid as mounted to a standard steel can, together with associated rectilinear spring clip; and
FIG. 8 is a partial sectional elevation view taken substantially along the line 8--8 of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a dog 10 is held by a hand 12 of the owner via a leash 14 which extends to a collar 16 which circumscribes the neck of the dog 10. A plastic container lid 18 with integral molded scoop 20 is suspended from the collar 16 by means of a hook 22 which extends from the upper surface of the lid 18 about the collar 16. A plastic container 24 is also suspended from the collar 16, by means of a hook 26, which extends from the outer side surface of the container 24 about the collar 16 (see insert). As will appear infra, the open mouth of the container 24 is mateable with the lid 18, and these elements are mated with the scoop 20 inside the container 24, after the scoop 20 has been employed to manually scoop up feces discharged by the dog 10.
FIG. 2 shows the manual manipulation of the lid 18 and integral scoop 20, to pick up or scoop up a body 28 of dog feces deposited by the dog 10 on a surface 30. The hand 12 grasps the hook 22, typically between the thumb 32 and forefinger 34, so that the entire lid-integral scoop unit may be manually manipulated and moved in the direction shown by an arrow 36, thereby scooping up the feces 28 onto the upper surface of the scoop 20, and off of the surface 30. Thereafter, elements 18 and 20 are held so that the scoop 20 is generally horizontal, until the lid 18 is fitted onto the open mouth of the container 24, shown in FIG. 3, with the scoop 20 inside the container 24, and with a section 38 of the scoop 20 disposed generally parallel to a wall 40 of the container 24, and with the dog feces 28 now collected in the bottom 42 of the container 24 (FIG. 4). As shown in FIG. 5, the section 38 and in fact most of the entire scoop 20 has a curved planar surface and the scoop 20 (section 38) is concentric with the wall 40 of the container 24. As best seen in FIG. 2, the scoop 20 being curved and planar is also concentric with the outer circular edge of the lid 18.
The outer edge of the disc-shaped lid member 18 is preferably provided with structure of a configuration to accommodate emplacement of the lid 18 onto the open mouth of either the present plastic container 24 or a standard-sized used steel can or container. This latter usage of lid 18 with integral scoop 20 will be discussed infra. The outer edge of the lid 18 is thus provided with (see FIGS. 2 and 4) means about the perimeter of the disc-shaped member 18 for securing the member 18 to the circular top free edge of an open cylindrical container per se. The perimetral securing means includes an inner circular protuberance 44 and an outer circular protuberance 46. As shown, the protuberances 44 and 46 are disposed on opposite sides of an annular channel 48 in the disc-shaped member 18, which in this embodiment of the invention is dome-shaped (see FIG. 4).
As shown, the planar scoop means 20 extends and depends from an annular inner portion of the disc-shaped member 18 adjacent the inner protuberance 44. In this embodiment of the invention, the scoop means 20 has a curved surface and is concentric with the circular edge of the disc-shaped member 18.
As shown in FIG. 4, the perimeter of the disc-shaped member 18 is preferably provided with an annular lip 50, the lip 50 extending outwards from the perimeter of the disc-shaped lid member 18. The lip 50 is provided so that, at the discretion of the user, the lid 18--integral scoop 20 combination is detachable from its mounting to the container 24 by manipulation, i.e. by placing the finger 52 under the lip 50 and exerting force in the upwards direction shown by arrow 54.
The open-mouthed container 24, in this embodiment of the invention, is provided with structure about its open mouth which cooperates with the annuar lid structure (elements 44, 46, 48) to detachably secure the lid member 18 to the container 24. Thus, the container 24 is an open cylindrical container having a circular top free edge 56 about its mouth (FIG. 4). The free edge 56 is or has a generally circular enlargement with an inner circular channel 58 and an outer circular protuberance 60. As shown, the channel 58 receives and cooperates with the inner lid protuberance 44 described supra, with the protuberance extending into the channel 58. Concomitantly, the protuberance 60 extends into the channel 48 and is juxtaposed with the outer lid protuberance 46 described supra in a contiguous relationship, so that as seen in FIG. 4, the lid member 18 is firmly held to the free edge enlargement 56 of the container 24. This attachment is detachable, e.g. by moving the finger 52 upwards per arrow 54 as described supra, since the lid member 18 and the container 24 are composed of a flexible resilient plastic, e.g. polyvinyl chloride, polyethylene, or polypropylene, so that the lid 18 may be snapped on or off of the container 24.
In this preferred embodiment of the invention, terminal surface 62 of the free edge 56 of the container 24 is inclined, typically at an acute angle, relative to the container wall 40, with the terminal surface 62 extending between the inner channel 58 and the outer protuberance 60. As shown in FIG. 4, the angle of inclination of the terminal surface 62 is generally equal to the angle of enlargement of the scoop means 20 at 64 adjacent its inner protuberance 44.
In this preferred embodiment of the invention, the scoop means 20 is also characterized by the provision of additional structural features. Thus, the scoop means 20 tapers at 66 inwards and away from its inner protuberance 44. Also, as seen in FIGS. 2 and 4, the free working edge or tip 68 of the scoop means 20 curves inwards from its lateral ends so as to provide a central recess region which facilitates initial passage of the feces 28 centrally onto the upper surface of the scoop 20 (FIG. 2). Thus the feces 28 is not dispersed laterally when being removed from the surface 30, but instead is centrally directed along the longitudinal axis of the scoop means 20 and towards the lid member 18.
Referring now to FIG. 6, the lid member 18 with integral scoop 20 as described supra is shown in place in conjunction with a used standard sized steel can or container 70. The lid 18-scoop 20 combination has been emplaced over the open mouth of the can 70, which open mouth has the typical can edge 72 as commercially manufactured with a circular bead or folded over ridge edge enlargement which was made when the can 70 was previously top sealed with its original contents inside, e.g. soup, vegetables, juice, dog food, etc. As shown, the present lid configuration accommodates the securing of the lid 18 to the used standard sized steel can 70, with the outer protuberance 46 of the lid 18 fitting in under the outer portion of the bead or can edge 72.
In a preferred embodiment of the invention as shown in FIGS. 7 and 8, alternative and ancillary structure may be provided in instances when the lid-scoop combination is to be primarily made, sold and used specifically in conjunction with a used standard sized steel can. Thus, referring now to FIGS. 7 and 8, the invention in this instance includes a rectilinear spring clip 74 which is mounted to the balance of the members after a lid 76 has been emplaced over the open mouth of a used standard sized steel can 78. The spring clip 74 has an upper lateral extension 80 for engagement of the edge of the disc-shaped lid member 76. As last seen in FIG. 8, the lid member 76 in this embodiment of the invention has an annular channel 82 to accommodate the bent or curved end 84 of the upper lateral extension 80. The spring clip 74 also has a lower lateral extension 86 for engagement of the bottom edge 88 of the container 78. The provision of the rectilinear spring clip serves to supplement the primary mode of engagement of the lid 76 to the container 78, e.g. as shown in FIG. 8, the bead 90 about the edge of the mouth of the can 78 fits into a lateral channel 92 in the annular edge 94 of the lid 76, with the outer protuberance 96 of the lid 76 fitting in under the outer portion of the bead or can edge 90. The rectilinear spring clip 74 may be sold as a component of a unitary package including the present lid with integral scoop, a number of lids with a reusable clip.
Finally, referring to FIG. 7, in this preferred embodiment of the invention, the spring clip 74 has a twisted portion 98 along its length, for manipulation of the spring clip 74. Also, an alternative embodiment of hook means is shown in FIG. 7, i.e. two hooks 100 and 102 on the lid 76, the hooks 100 and 102 being aligned on a common axis of symmetry and having opposed openings.
It will be appreciated by those skilled in the art that the specific hook means selected in a particular instance, or for that matter other appurtenances to the invention as described supra, will be selected by one skilled in the art in a particular instance depending on the particular application of the invention. Thus, for example, in large scale applications, e.g. the moving or spreading of sand or rock salt, it would be advantageous to have the lid and scoop made thicker in dimension and/or material. In this case, the lid-scoop combination would not really be disposable, and a suitable handle could be provided on the top of the lid instead of a hook. This would be especially true if the lid was intended to fit onto the mouth of the larger used standard steel cans, e.g. juice cans originally used to contain orange, tomato, apple or grapefruit juice or vegetable juice cocktail.
It thus will be seen that there is provided a container and container lid which achieves the various objects of the invention and which is well adapted to meet the conditions of practical use.
As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. Thus, it will be understood by those skilled in the art that although preferred and alternative embodiments have been shown and described in accordance with the Patent Statutes, the invention is not limited thereto or thereby. | A container and lid therefor in which the lid has annular or perimetral structure for mounting the lid on the container, as well as a dependent integral scoop for removal of a substance from a surface. The lid and scoop combination per se is especially intended for the removal of dog droppings, i.e. dog feces, from sidewalks, etc. in the urban environment. Thereafter, the lid-scoop member laden with dog feces may be fitted onto the open end of a used container such as a used standard steel can, e.g. a used and empty soup, vegetable or dog food can. The container lid features, in addition to the integral scoop, perimetral elements about the disc-shaped lid for securing the disc-shaped lid member to the circular top free edge of the open cylindrical container, e.g. a used standard steel can. These perimetral elements include inner and outer circular protuberances on opposite sides of an annular channel in the disc-shaped member. | 4 |
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The invention relates to a circuit configuration for generating a boosted output voltage, having a p-channel MOS transistor and a boosting capacitor.
Such circuit configurations, which generate an output voltage that is boosted above the applied supply voltage, are employed in a large number of semiconductor circuits, in particular in semiconductor memories. A single-transistor memory cell of a semiconductor memory, for example of a DRAM, includes a storage capacitor for storing an information bit as well as a transfer transistor through which access is made to the memory cell by the storage capacitor being connected to a word line through the main current path of the transfer transistor. In order to store an information bit at the level of the complete level of the supply voltage in the cell, it is necessary for the gate potential at the transfer transistor to lie above the supply voltage by that transistor's own threshold voltage. However, due to the usually small channel width of the transfer transistor and the high substrate-source voltage thereof, the threshold voltage is relatively high.
A circuit configuration for generating the boosted voltage for driving a transfer transistor in a semiconductor memory is described in Published European Patent Application 0 635 837 A2. A charge pump shown therein contains a p-channel MOS transistor through which a charging capacitor on the output side is charged by a boosting capacitor. The charging operation is controlled by an oscillator and is carried out continuously, with the output voltage being permanently present. Therefore, additional switches are necessary in order to forward the boosted voltage to the transfer transistor. While the gate terminal of the p-channel MOS transistor is at 0V, one of the terminals of its main current path is already connected to the output voltage which is applied to the charging capacitor and is boosted beyond the supply voltage. The gate oxide of the p-channel charging transistor is exposed to elevated voltage stress. Furthermore, the voltage present between the terminals of the main current path of the load transistor changes its direction during the pumping operation. Therefore, special measures are described for avoiding current flow in the doping well in which the charging transistor is disposed.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a circuit configuration for generating a boosted output voltage, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and in which a p-channel MOS charging transistor is subjected to less voltage stress.
With the foregoing and other objects in view there is provided, in accordance with the invention, a circuit configuration for generating a boosted output voltage, comprising an output terminal for tapping a boosted output voltage; a p-channel MOS transistor having a main current path connected to the output terminal and having a gate terminal; a boosting capacitor having one terminal connected to and another terminal remote from the main current path of the p-channel MOS transistor; a first precharging transistor connected to the output terminal; a second precharging transistor connected to the boosting capacitor; and a control circuit for ensuring that during a first phase the gate terminal of the p-channel MOS transistor is held at a low potential and the precharging transistors are turned on, that during a second phase the gate terminal of the p-channel MOS transistor has a floating potential, and that the other terminal of the boosting capacitor has a low potential during the first phase and a high potential during the second phase.
As a result of the fact that the gate potential of the charging transistor is kept floating during the charge pumping phase, instances of impermissibly high voltage loading on the gate oxide are avoided. In this case, the pumping phase is that time period during which the output voltage is raised beyond the supply voltage. As a result of the parasitic capacitances at the charging transistor, the gate potential is incorporated during the voltage boosting, with the result that the transistor remains in the on state. However, the voltages between the gate and the doping regions for the drain and source of the charging transistor nevertheless remain smaller than the supply voltage.
In accordance with another feature of the invention, there is provided a terminal for a positive pole of a supply voltage; and a terminal for a negative pole of the supply voltage; the control circuit having a current path with a first transistor connected to the terminal for the positive pole of the supply voltage, and a second transistor connected to the terminal for the negative pole of the supply voltage; the first and second transistors interconnected at a coupling node connected to the gate of the p-channel MOS transistor; and the second transistor being switched on during the first phase, neither of the first and second transistors being switched on during the second phase, and the first transistor being switched on outside the first and second phases.
In accordance with a further feature of the invention, there is provided a circuit configuration driving the second precharging transistor and generating a boosted voltage during and at a time period before the first phase.
In accordance with an added feature of the invention, there is provided a first delay element having an output; a second delay element connected downstream of the first delay element and having an output; the control circuit receiving a control signal delayed by the delay elements; the output of the first delay element driving the first transistor; a logic gate connected between the output of the first delay element and the second transistor for driving the second transistor; the output of the second delay element driving the second transistor through the logic gate; the output of the second delay element driving the other terminal of the boosting capacitor; and a further logic gate receiving the control signal and connected to the other terminal of the boosting capacitor for driving the other terminal of the boosting capacitor.
In accordance with an additional feature of the invention, there is provided a limiting circuit connected to the gate terminal of the p-channel MOS transistor for limiting a potential at the gate terminal to the positive pole of the supply voltage.
In accordance with yet another feature of the invention, there is provided a discharge transistor connected to the output terminal and switched on outside the first and second phases.
In accordance with a concomitant feature of the invention, there is provided a circuit node coupled to the boosting capacitor, the p-channel transistor realized in an n-type well in a p-type substrate, and the well connected to the circuit node.
The effect achieved by precharging transistors at both terminals of the main current path of the charging transistor as well as a discharge transistor on the output side and a corresponding sequence controller, is that during each pumping cycle of the output voltage, a value range from 0 V up to the boosted output voltage value is traversed. At the same time, the voltage at the terminals of the main current path of the charging transistor persistently has the same orientation. The doping well in which the charging transistor is connected can therefore readily be connected to a voltage node located at the side of the boosting capacitor.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a circuit configuration for generating a boosted output voltage, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and block circuit diagram of an inventive circuit configuration for generating a boosted output voltage; and
FIG. 2 is a timing diagram of signals occurring in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a circuit which contains a p-channel MOS transistor 1, having a main current path that is connected between an output terminal or node 29 and a boosting capacitor 2 connected to a node 31. An output signal WDRV is present at the terminal 29 and yields a higher output voltage than that yielded by potentials VDD, VSS of a supply voltage. A first n-channel MOS transistor 3 is connected as a precharging transistor between the output terminal 29 and a terminal for the positive supply potential VDD. A second precharging transistor 4 is disposed between the boosting capacitor-side terminal of the transistor 1 and the supply potential VDD. An n-channel MOS transistor 6 serves as a discharge transistor and is disposed between the output terminal or node 29 and a terminal for the ground potential VSS.
While a terminal 30 of the boosting capacitor 2 which is remote from the transistor 1 is at low level (e.g. ground potential VSS), it is charged through the precharging transistor 4. The output terminal or node 29 is precharged in a corresponding manner through the precharging transistor 3. The transistor 1 is then switched on for the purpose of potential equalization between the nodes 29, 31. Afterwards, its gate terminal is held at a floating potential, and the terminal 30 of the boosting capacitor 2 is raised to high potential (e.g. the potential VDD), with the result that the output signal WDRV has a potential which is boosted by the boosting capacitor voltage above the positive supply potential VDD. During turn-off, the node 29 is discharged through the then switched-on transistor 6 and pulled to ground potential VSS, and the terminal 30 of the boosting capacitor is again put at low potential.
The method of operation of the circuit shown in FIG. 1 is described in detail below with reference to the signal profile diagram illustrated in FIG. 2. At the beginning, the node 31 is charged from the positive supply potential VDD through the transistor 4. A signal A at the node 31 then has the positive supply potential minus the threshold voltage of the n-channel transistor 4 (VDD-Vthn). When a signal RINTN is activated, i.e. when the signal RINTN changes from an H to an L level, a configuration 5 is activated which already generates a potential lying above the supply potential VDD, as a result of which the transistor 4 is driven with a sufficiently high gate voltage to cause the node 31 to be completely raised to the supply potential VDD (point 50 in FIG. 2). A pumping operation is initiated with an activation of a signal XVLD. In a semiconductor memory, the signal XVLD is generated when access addresses for the memory cell array are present in a stable manner. A signal D at a gate terminal of the transistor 6 is generated from the signal XVLD through the use of an invertor 7. It has the effect of turning off the discharge transistor 6. Slightly later, an edge of a signal E which drives the gate terminal of the precharging transistor 3 is generated from the signal XVLD through the use of two invertors 8, 9. As a result, the potential at the output terminal 29 is raised to the supply potential VDD minus the threshold voltage of the transistor 3 (point 51). It is important that the transistors 6, 3 be turned off and on, respectively, in a manner which is staggered over time in the way that has just been described, so that no conductive current path exists between the supply voltage terminals.
A gate terminal of the charging transistor 1 is connected to a current path which is connected between the supply voltage VDD, VSS and contains first and second p-channel MOS transistors 20, 21, that have main current paths connected in series. The gate terminal of the transistor 1 is connected to a coupling node of the transistors 20, 21. A gate terminal of the transistor 21 on the ground side is driven through a NAND gate 22. The NAND gate 22 has inputs which are controlled by the signal XVLD. On one hand, the signal XVLD is applied to the NAND gate 22 through a first delay element 23, and on the other hand, the signal XVLD is applied to the NAND gate 22 through a second delay element 24 connected in series with the first delay element 23 as well as an invertor 25. The effect of this configuration is that after the delay time caused by the delay element 23 has elapsed, a signal B at the gate terminal of the transistor 21 is pulled to ground (point 52). As a result, the gate potential of the transistor 1 is put at ground potential VSS plus the threshold voltage of the transistor 21 (VSS+VThp; point 53). The transistor 1 is thus completely switched on, with the result that potential equalization between the nodes 29, 31 ensues (point 54). After the delay caused by the second delay element 24 and the invertor 25, the transistor 21 is turned off again through the NAND gate 22 (points 55, 56).
The terminal 30 of the boosting capacitor 2 is connected through an invertor 28 to a further NAND gate 27. One input of the further NAND gate 27 is driven by the signal XVLD and another input thereof is driven by the signal XVLD delayed by the delay elements 23, 24, the invertor 25 and an invertor 26. The effect of this configuration is that the node 31 is raised from the ground potential VSS to the positive supply potential VDD (points 63, 57). Since the transistors 21, 20 of the current path which drives the gate terminal of the transistor 1 are both in the off state, the gate potential of the transistor 1 has a floating behavior. This means that the gate potential is not held actively at a fixed level, but rather behaves in accordance with the parasitically acting circuitry. What is particularly active in this case is a parasitic capacitance of the gate with respect to the channel and, moreover, its parasitic capacitance with respect to doping regions of a drain and a source of the main current path of the transistor 1. The capacitance per unit length is essentially set by the gate oxide thickness. The remaining capacitive loading of the gate terminal, for example, with respect to the drain and source doping regions of the transistors 20, 21, is significantly lower than the above-mentioned parasitic capacitances. Since the gate of the transistor 1 is floating, it is capacitively adjusted with the rise of the node 31 through the use of the positive supply potential VDD. The transistor 1 therefore remains sufficiently conductive to pass the potential present at the node 31 on to the output node 29 (point 58). The output signal WDRV is then at the desired boosted output voltage. This enables a transfer transistor driven by the signal WDRV in the cell array of a semiconductor memory to pass the entire operating voltage VDD on to a connected storage capacitor.
In order to increase operational reliability, a circuit 10 is provided which limits the gate potential of the transistor 1 to the positive supply potential VDD. This is intended to prevent a parasitic diode with respect to the n-type well of the p-channel MOS transistor 1 from being switched on. Conventional limiting circuits are provided for the circuit 10. Such a circuit includes, for example, an MOS diode formed by an n-channel MOS transistor having a gate terminal that is connected, together with a terminal of its main current path, to the gate terminal of the transistor 1, and having another terminal of the main current path that is connected to a potential VDD-VThn.
The turn-off operation is initiated by the falling edge of the signal XVLD. In response to this, after a delay provided through the use of the invertor 7, the transistor 6 is turned on and the signal WDRV is pulled down to ground potential (point 59). In the meantime, moreover, after a delay provided through the use of the invertors 8, 9, the signal E is switched over from an H level to an L level. In this case, it must be taken into account that the gate-source voltage of the transistor 3 always lies below its threshold voltage, so that the transistor 3 is turned off and no conductive current path is present between the supply voltage terminals. In an expedient manner, the signal WDRV is always greater than the potential at the gate of the transistor 3, since the discharge edge of the signal E falls more rapidly than the edge of the signal WDRV. This switching behavior of the signals D, E is achieved by appropriate dimensioning of the invertors 7 and 9, 8. When the transistor 6 is turned on, the potential of the node 31 is reduced since the transistor 1 momentarily switches on (point 60). With the falling edge of the signal XVLD, the node 30 is also pulled to ground through the NAND gate 27 and the invertor 28, thereby assisting the discharge of the node 31 (point 64). The transistor 1 is then completely turned off by the transistor 20 which is connected to the potential VDD being switched on (point 61). The node 31 is then once again pulled to the potential VDD-VThn (point 62), with the result that the initial state is present.
In the realization shown in FIG. 1, the terminal of the main current path of the transistor 1 which faces the node 31 always has a higher potential than the terminal of the main current path which faces the output terminal 29. It is therefore expedient to connect the n-type doping well in which the p-channel MOS transistor 1 is realized, given a p-type substrate, to the line path facing the boosting capacitor 2, for example to the corresponding doping region connected thereto. Substrate-well diodes are thus always reliably switched off.
The capacitance of the boosting capacitor 2 is calculated on the basis of capacitive voltage division between the boosting capacitor 2 and the capacitive loading connected to the output terminal 29, while taking account of the desired level of the output voltage. The circuit described herein takes up a relatively small area and has a small number of components. Although the entire voltage range from ground potential (0 V) up to the boosted output voltage lying above the positive supply potential VDD is traversed during each pumping operation, neither critical voltage ratios nor undesirable well effects are produced. The voltages occurring between the gate and the doping regions of the charging transistor 1 are smaller than the supply voltage VSS, VDD, with the result that excessive voltage stress on the gate oxide of the transistor 1 is avoided. The elements 20-28 may collectively be referred to as a control circuit. | A circuit configuration for generating an output voltage which is boosted beyond a supply voltage includes a boosting capacitor that is connected through a p-channel MOS transistor to an output node. A control circuit ensures that first of all the boosting capacitor and the output node are precharged through the use of respective precharging transistors when the p-channel MOS transistor is turned on, and that subsequently, during a shifting phase, the gate terminal of the p-channel MOS transistor is held at a floating potential. This prevents the voltage present between the gate and the main current path terminals of the p-channel MOS transistor from becoming greater than the supply voltage. | 6 |
BACKGROUND
In known looms of this type, the bulges in the teeth of the reed which form the guide channel for the fluid are so developed and the reed is so controlled in its forward and backward movement that the filling thread inserted remains in the guide channel during the beating-up and emerges from the guide channel only upon the subsequent rearward movement of the lay. The beating-up of the filling threads therefore is effected by the portions of the teeth of the reed which form the lowest point in the bulges.
With this known development, difficulties result with regard to the shaping and arrangement of the stretchers necessary to obtain a proper fabric. If the stretchers are of conventional development, they cannot be arranged at a sufficiently small distance in front of the place where the filling thread is beaten-up, since on the one hand the teeth of the reed have portions which extend forward beyond the place of beating-up in the beating-up position, said portions having the flanks of the bulges which form the guide channel, while on the other hand there is no room for the stretchers in the cross-section of the guide channel. However, an insufficiently small distance between the beating-up point and the stretchers results in the disadvantage that upon the beating-up of the filling yarn, the fabric shrinks somewhat in its width and as a result the warp yarns are no longer parallel in the regions of the edges of the shed, which may impede the movement of the reed and lead to a scraping of the teeth of the reed against the warp yarns. In order to exclude this disadvantage, it has been attempted to adapt the development of the stretchers and of the bulges of the reed teeth which form the guide channel to each other in such a manner that the stretchers enter the guide channel upon the beating-up movement of the reed. This, however, requires a special flat construction of the stretchers which is of little strength and is less protective of the cloth than the traditional stretchers for which there is no room in the cross-section of the guide channel.
Looms are also known in which the devices for the insertion of the filling yarns by means of a fluid have a comb of parallel confusor blades, each having a bulge to form the guide channel for the fluid serving for the insertion of the filling yarn, the confusor blades being separated from the reed teeth but being firmly connected with the lay in such a manner that they emerge completely from the shed during the beating-up movement of the lay so as to enable the reed to beat-up the filling yarn which has been previously inserted and upon the subsequent rearward movement of the lay again to move between warp yarns in order upon the next insertion of the filling yarn to provide the desired guidance within the shed of the fluid which inserts the warp yarn. With this development of the machine, the reed can be provided in conventional manner with linearly extending reed teeth and it is possible to mount the stretchers of ordinary construction sufficiently close to the fell of the cloth so that no problems occur in this respect. On the other hand, with this development of the loom, the insertion of the confusor blades between war yarns after the beating-up of each filling yarn is not without difficulties since at times a warp yarn may be caught on a confusor blade which leads to weaving defects and may cause the breaking of warp yarns.
SUMMARY
The present invention relates to devices for a loom of the aforementioned type capable of functioning in such a way, in a relatively simple manner, in order to avoid the above-described disadvantages of known embodiments that either require confusor blades which move in and out between warp yarns or special stretchers in order to be able to maintain the desirably small distance between the fell of the cloth and the stretchers. Therefore, the devices of the present invention will accommodate stretchers of conventional construction since they can be mounted directly in front of the fell of the cloth.
The objects of this invention are achieved essentially in a loom of the aforementioned type in the manner that an at least approximately linear portion of the tooth smoothly joins the bulge of each reed tooth and the forward and backward movement of the reed is conducted in such a manner that the bulges of the reed teeth lie within the shed when the reed is in the position in which the insertion of the filling yarn takes place and the linear portion of the reed tooth is located at the place of beating-up when the reed is in the filling-yarn beating-up position.
With this development the result is obtained that the filling yarn which is introduced into the guide channel by means of a fluid insertion, for instance compressed air, during the beating-up movement of the lay comes out of the bulges of the reed teeth and comes to lie in front of the linearly extending portions of the reed teeth and that the beating-up of the filling yarn against the cloth which has already been woven is effected by means of the linear portions of the reed teeth. The stretchers can therefore be arranged without difficulty at a sufficiently small distance from the place where the warp yarn is beaten-up even if they are of conventional development since upon the beating-up of the filling yarn the stretchers do not have to enter into the guide channel formed by the bulges in the reed teeth. Nevertheless there are no confusor blades to be moved in and out between warp yarns and which could give rise to weaving defects and the breaking of warp yarns. In one suitable embodiment the linearly extending portion and the adjoining flank of the bulge of each reed tooth are at an angle of between 135° and 180° and preferably 150° to 180° to each other while the other flank of the bulge and the linearly extending portion of each reed tooth are advantageously at an angle of about 90° apart.
The reed is preferably moved back and forth in known manner by means of swingably supported lay swords. In a preferred embodiment of the invention, the path of movement of the bulge of each reed tooth may extend along a circular arc which obliquely intersects the group of warp yarns facing the axis of swing of the lay swords when the shed is open and the linearly extending portion of the reed teeth, when the reed is in the beating-up position, extends at least approximately at right angles to the middle warp-yarn direction and is inclined with respect to a line radial to the axis of swing of the lay swords which passes through the vertex of the bulge.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details of the invention will become evident from the following description of specific embodiments and from the corresponding drawings which show the subject matter of the invention diagrammatically and by way of example, and which merely illustrate the subject matter of the invention, in which:
FIG. 1 shows in vertical view along the warp yarns a portion of a loom having the device of this invention, the device shown in solid lines in its position upon the insertion of the filling yarn, and in dot-dash lines in its position at the beating-up point of the filling yarn;
FIG. 2 shows a partial vertical view of an individual reed tooth of the part of the loom shown in FIG. 1;
FIG. 3 shows a second embodiment of reed tooth similar to the part of the loom illustrated in FIG. 1; and
FIG. 4 shows a partial vertical view of an individual reed tooth of the part of the loom shown in FIG. 3.
DESCRIPTION OF PREFERRED EMBODIMENTS
The loom shown in FIG. 1 has a lay 11 which bears a reed 12. The lay 11 is supported by lay swords 13 which are swingable around an axis lying outside the plane of the drawing. In known manner the lay swords 13 are so driven by cranks or eccentrics (not shown) of the main shaft of the loom via connecting rods that upon rotation of the main shaft a backward and forward swinging movement of the lay swords 13 and of the lay 11 takes place.
The reed 12 has blade shaped reed teeth 20 only one of which is visible in FIG. 1 since the reed teeth cover one another. Between the reed teeth there pass in customary fashion warp yarns 21 and 22 which, together with the filling yarns (not shown) form the cloth 23 which is to be produced. The shed 24 necessary for the insertion of the weft yarns between an upper group of warp yarns 21 and a lower group of warp yarns 22 is formed in known manner (not shown) by means of shafts. The beating-up of the previously inserted filling yarn against the cloth 23 which has already been produced is effected at the beating-up point (fell) 25 by means of the teeth 20 of the reed 12, as is generally known. At a slight distance from the beating-up point 25 there are located stretchers 26 of customary development each of which, by means of a fixed part 27 and a rotating part 28, grasps the selvage or edge portions of the cloth 23 produced and continuously pulls same outward so as to stretch the cloth in width so that the warp yarns 21 and 22 of the upper and lower groups of warp yarns always extend parallel towards the beating-up point 25.
Each reed tooth 20 is provided on the front side thereof facing the fell 25 with an inwardly directed bulge 30 which has its opening facing the fell 25. The bulges 30 of all the reed teeth 20 coincide with each other and together form a guide channel for a fluid serving for the insertion of the filling yarn, for instance compressed air. The said fluid is fed by means of a main nozzle located on one side of the shed and a plurality of auxiliary nozzles 31 from hoses 32 from a fluid source means 32A. The auxiliary nozzles 31 are distributed at suitable distances apart along the lay 11 and fastened to the lay. The outlet openings 33 of the nozzles 31 are so arranged and directed that a stream of fluid is produced in the guide channel formed by the bulges 30 transversely through the shed 24 when the nozzles are placed in operation. Immediately above the bulge 30, each reed tooth 20 has a linearly extending portion 34 which smoothly or directly joins the bulge 30. The said linearly extending portion 34 of the reed teeth serves for beating-up the previously introduced filling yarn against the cloth 23 which has already been produced.
The axis of swing of the lay swords 13 has a position which is so set back with respect to the beating-up point 25 that upon the forward and backward movement of the lay 11 the bulge 30 of each reed tooth 20 moves along an arcuate path 35 which obliquely intersects the lower group of warp yarns 22 in the open position of the shed. The guide channel for the fluid serving for the insertion of the filling yarn which is formed by the inwardly directed bulges 30 is located within the shed 24 when the lay 11 is moved towards the rear (towards the right in FIG. 1) into the filling yarn insertion position and is outside the shed when the lay 11 is moved into the filling yarn beating-up position (dot-dash lines in FIG. 1). In said last mentioned position of the lay 11, the linearly extending portion 34 of each reed tooth 20 is located at the beating-up point 25.
In order that the filling yarns can be properly beaten-up by the linearly extending portion 34 of each reed tooth 20, the reed 12 is so arranged that in the beating-up position of the reed the said linearly extending portion is approximately perpendicular to the middle direction 36 of the warp yarn and is thus not radial to the axis of swing of the lay swords 13 but differs by an angle α which lies for instance in the range of 25° to 30° from a radial line 37 to the axis of swing of the lay swords which passes through the vertex of the bulge 30.
As shown in the detailed view of FIG. 2, the bulge 30 of each reed tooth 20 has two approximately linear extending flanks 38 and 39 which are connected to each other by a circular arc 40 forming the vertex portion of the bulge. In the embodiment shown, the two extending flanks 38 and 39 form with each other an angle β which is approximately 60°, the linearly extending portion 34 and the adjoining upper flank 38 being at an angle γ to each other of about 150° while the lower flank 39 is approximately perpendicular to the linearly extending portion 34. By this development of the bulge 30, the result is obtained that on the one hand the filling yarn introduced by means of the fluid is secured by the lower flank 39 from dropping down while on the other hand upon the beating-up movement of the lay 11 the filling yarn slides along the upper flank 38 out of the bulge 30 to in front of the linearly extending portion 34 of each reed tooth 20 on a ridgeless smooth surface while the bulge 30 moves out of the shed 24 along its arcuate path of movement 35 (see FIGS. 1 and 3).
The manner of operation of the devices for the insertion and beating-up of the filling yarns which have been described is as follows:
When the lay 11 moves into its upper dead center position, i.e. into its greatest possible distance from the filling yarn beating-up point 25, the reed 12 and the nozzles 31 assume the solid line positions shown in FIG. 1. While the bulge 30 of each reed tooth 20 is within the open shed 24 and the nozzles 31 extend between warp yarns 22 of the lower group of warp yarns also into the shed 24, a filling yarn is introduced by the fluid flowing out of the main nozzle and the fluid from the auxiliary nozzles into the guide channel formed by the bulges 30 of the reed teeth 12. Upon the subsequent forward movement of the lay 11 towards the beating-up point 25, the bulges 30 of the reed teeth 12 move along the arcuate path of movement 35 obliquely downward out of the shed 24. In this connection the previously inserted filling yarn is moved by the reed 12 against the beating-up point 25 but it is prevented by the lower group of warp yarns 22 from following along in the downward movement of the bulges 30 of the reed teeth. Therefore, the filling yarn slides along the upper flank 38 of the bulges 30 upward until it emerges completely from the bulges and comes to lie in front of the linearly extending portion 34 of the reed teeth 12. When the lay 11 and the reed 12 assume the position shown in dot-dash outline as in FIG. 1, the filling yarn is beaten-up by the linearly extending portion 34 of the reed teeth 20 against the previously produced cloth 23 at the point 24 which is located in the immediate vicinity of the stretchers 26. Since the nozzles 31 are firmly arranged on the lay 11 and do not move relative to the reed 12, the nozzles move downward out of the shed upon the said beating-up movement of the lay 11 before the reed comes into the vicinity of the beating-up point 25. The beating-up of the filling yarn is therefore in no way impeded by the nozzles 31.
After the filling yarn has been beaten-up against the cloth 23, the lay 11, together with the reed 12 and the nozzles 31, moves back in opposite direction into the position which permits the introduction of the filling yarn, whereupon the processes described are repeated.
It will be appreciated that the values indicated in the above-described embodiment for the angles α, β, and γ can vary within limits. Thus, for instance, the angle β can be reduced to 45°, in which case the angle α assumes a value of 135°. Values of less than 45° for the angle β and 135° for the angle γ are inadvisable, since in such case the sliding of the filling yarn out of the bulges 30 along the upper flank 38 is made difficult or even impossible. Conversely, it may be advantageous to increase the angle β to for instance about 75°, in which case the angle γ assumes a value of about 165°. In the extreme case, the angle β may even amount to about 90° and the angle γ to 180°, as shown in the embodiment of FIGS. 3 and 4.
The second embodiment, shown in FIGS. 3 and 4, will be described below only with reference to its differences from the first embodiment. The same reference numbers as in FIGS. 1 and 2 have been used for identical parts. The main difference resides in the shape of the reed teeth. In the embodiment of FIGS. 3 and 4 reed 112 has bladelike reed teeth 120, each of which is provided with a bulge 130 on the front side thereof facing the beating-up point 25. This bulge 130 has two linearly developed flanks 138 and 139 which are connected to each other by an arcuate vertex portion 140. The two flanks 138 and 139 form an angle β' with each other which is substantially about 90°. The one flank 138 passes smoothly and without change of direction into a linearly extending portion 134 which serves to beat the inserted filling yarn against the cloth 23 which has already been formed. The other flank 138 is approximately perpendicular to the said linearly extending portion 134.
The axis of swing (located outside the sheet of the drawing) of the lay swords 13 is so far towards the rear with respect to the beating-up point 25, i.e. to the right in FIG. 3, that upon the backward and forward movements of the lay 11, the bulge 130 of each reed tooth 120 passes over an arcuate path of movement 135 which obliquely intersects the lower warp yarns 22 when the shed is open. The reed 120 is so arranged that in the beating-up position, shown in dot-dash line, the linearly extending portion 134 of each reed tooth is approximately perpendicular to the middle warp-yarn direction 36. This means that the said linearly extending portion 134 is not radial to the axis of swing of the lay swords 13 but is inclined with respect to a line 137 radial to the axis of swing rearward by an angle α' which is equal, for instance, to about 30°.
The manner of operation of the reed 112 and of the devices for the insertion of the filling yarns by means of a fluid is in principle the same as in the case of the first embodiment and therefore no description thereof is deemed necessary.
The second embodiment has advantages over the first embodiment since during the beating-up movement of the reed 112 the previously inserted filling yarn slides more easily out of the guide channel formed by the bulges 130 upwards to and in front of the linearly extending portions 134 of the reed teeth which serve for the beating-up of the filling yarn. On the other hand, however, there is the advantage in the case of the first embodiment that the jet of fluid emerging from the nozzles 31 is better held together in the guide channel, since the angle β is less than the angle β' forming the guide channel.
It is clear that in each of the embodiments of the invention described, the filling yarn beating-up point 25 lies at a very small distance from the stretchers 26 although these stretchers are of conventional construction and although no confusor blades, which are separate from the reed teeth and would have to be periodically moved out of the warp yarns and then introduced again between them, are necessary for the forming of the guide channel for the fluid serving for the insertion of the filling yarn.
It will be appreciated that various changes and modifications may be made within the skill of the art without departing from the spirit and scope of the invention illustrated and described herein. | The present invention relates to devices for use in a loom for fluid insertion of the filling yarn, the loom having a reed, each of whose teeth defines a bulge with the opening of the bulge facing the fell of the cloth being woven to provide for better beat-up, all of said bulges together forming a guide channel for the passage of fluid which serves for the insertion of the filling yarn. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention is directed to an improved data processing system. More specifically, the present invention is directed to an apparatus, system and method for providing speech recognition assist in call handover.
[0003] 2. Description of Related Art
[0004] In support operations it is customary to organize the call center in terms of “levels of support.” For example, level-1 support personnel are trained in basic diagnostic and remediation procedures only. Level-2 personnel are typically more specialized and are trained in a particular area of support. Calls are answered by level-1 personnel and if they determine that the assistance of level-2 personnel is required, they determine which specialization to hand the call over to, initiate a connection to the appropriate level-2 specialist, and inform the caller that they are being transferred to another support person. This organization allows many of the support calls to be handled by level-1 personnel who are typically paid less. This minimizes the overall cost of providing support without limiting the ability of the support center to handle difficult cases, requiring specialized training.
[0005] A caller who finds that the initial support personnel cannot handle their problem and is handed over to a level-2 support professional, often must repeat some or all of the information provided to the level-1 person. Basic identifying information, such as name, address, and product identification is often captured by the level-1 person using a computer-based software application, such as applications which store data provided by the operator by filling in a form. But often, the caller provides information relating to the reason for the call in an unstructured manner in response to questions posed by the call-taker, and this information is difficult to summarize and key into a computer system quickly.
[0006] More to the point, the call-taker may ultimately be able to resolve the caller's problem so that it will prove unnecessary to capture such information in a computer system. However, if the call is ultimately transferred to a level-2 specialist, this information may be of importance. Since most calls are handled by level-1 personnel, the default policy is not to take time to capture the caller-provided problem information. Rather, the level-1 personnel are forced to provide, if anything, a very concise summary of the caller's problem.
[0007] This is a source of potential error in that the level-1 personnel may not summarize the caller's problem appropriately or essential details may not be provided. Therefore, it would be beneficial to have an apparatus, system and method for capturing caller problem information to assist in call handover.
SUMMARY OF THE INVENTION
[0008] The present invention provides an apparatus, system and method for providing speech recognition assist in call handover. The apparatus, system and method provide a mechanism by which the capture of caller-provided information relating to the problem or reason for the call can be efficiently captured in a computer system so that it can be made available to level-2 specialists if necessary. This capturing of caller-provided problem information does not diminish the efficiency of the level-1 call taker since the mechanism of the present invention operates without requiring the level-1 call taker to learn new procedures. In fact, the mechanism of the present invention may increase the efficiency of the level-1 call taker since the level-1 call taker is no longer required to manually provide a brief summary of the caller's problem by keying the summary into a computer using a computer keyboard.
[0009] With the apparatus, system and method of the present invention, in a preferred embodiment, spoken utterances of the call taker, not the caller, are captured using speech recognition technology. This permits optimum use of speech recognition technology. The call taker can use a noise-canceling microphone placed optimally to receive voice input from the call taker. The speech recognition system can be trained to the specific speech patterns of the call taker and the vocabulary of the speech recognition system can be limited to the specific domain of discourse related to the job scope of the call taker.
[0010] With the mechanism of the present invention, the time a highly-trained and highly-paid specialist must spend with a caller who has been handed over to him/her is appreciably reduced. In addition, the caller experience is improved since the caller is not required to repeat information provided to the lower level call takers. Moreover, the present invention provides for capturing of problem information in a computer-accessible form so that the information may be analyzed at a later time in order to optimize the training and procedures of the level-1 and level-2 call takers. Other features and advantages of the present invention will be described in, or will become apparent to those of ordinary skill in the art in view of, the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
[0012] [0012]FIG. 1 is an exemplary block diagram of a distributed network in accordance with a known system for providing call support;
[0013] [0013]FIG. 2 is an exemplary block diagram of a distributed network in accordance with the present invention;
[0014] [0014]FIG. 3 is an exemplary block diagram of a speech recognition system in accordance with the present invention;
[0015] [0015]FIG. 4 is an exemplary diagram of a call-taker workstation interface in accordance with the present invention; and
[0016] [0016]FIG. 5 is a flowchart outlining an exemplary operation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] [0017]FIG. 1 is an exemplary block diagram of a distributed network of a known call support system. As shown in FIG. 1, the distributed network 100 includes a communication network 105 , a caller terminal 110 , and a call center 120 . The caller terminal 110 may be any type of mechanism capable of sending and receiving communication signals by way of a wired or wireless communication connection with the communication network 105 . The caller terminal 110 may be, for example, a conventional land-line telephone, a cellular telephone, an Internet based telephone device, a computer having a microphone or other audio input device, and the like. In a preferred embodiment, the caller terminal 110 is a conventional telephone of either the wired or wireless type.
[0018] The communication network 105 may be any type of network that provides communication pathways between caller terminals 110 and call center 120 . The communication network 105 may be, for example, a conventional telephone network, cellular telephone network, data network, satellite network, or the like. Moreover, the communication network 105 may be any combination of one or more of these types of networks. In a preferred embodiment, the communication network 105 is a conventional telephone network in which switches, routers, and the like, are used to route communication signals from a source terminal to a destination device or terminal. The routing of signals through a conventional telephone network is well known and thus, will not be further explained herein.
[0019] The call center 120 includes a call director 130 and a plurality of call taker workstations 140 - 180 . The call center 120 may further include computing devices and data storage (not shown) for controlling the operation of the call center 120 and storing data relevant to the operation of the call center 120 .
[0020] The call director 130 typically receives calls from caller terminals, such as caller terminal 110 , and determines to which call taker workstation 140 - 180 the call should be routed. Such routing of calls to call taker workstations 140 - 180 may be based on a workload management algorithm, a type of call being received, i.e. a call for technical assistance, a call for billing questions, etc., a type of caller placing the call, i.e. a good customer may be provided level-2 support rather than level-1 support, and the like. Any mechanism for determining which call taker workstation 140 - 180 is to handle the call is intended to be within the spirit and scope of the present invention.
[0021] For purposes of illustration, it will be assumed that a basic workload algorithm is used in which a call taker workstation that is not currently handling a call will be assigned to handle a currently pending call from a caller terminal. Thus, a first available call taker workstation will be assigned the task of handling the next call in a call queue of the call director 130 . In addition, while the present invention will be described in terms of tiers of support, e.g., level-1 and level-2 support, the present invention is not limited to such. Rather, these designations are only provided for illustration in order to differentiate between two human operator workstations rather than to imply any particular limitations of the present invention.
[0022] With the present invention, a caller initiates a call to call center 120 . The call may be initiated, for example, by a caller entering an address of the call center 120 via the caller terminal 110 , for example. As an example, the caller may initiate the call by dialing a telephone number associated with the call center 120 . The call director 130 of the call center 120 receives the call from the caller terminal 110 and places the call in a queue awaiting the first free level-1 call taker workstation 140 - 160 . When one of the level-1 call taker workstations 140 - 160 becomes free, i.e. is no longer involved in handling a call, the next call in the queue is forwarded to the free level-1 call taker workstation, e.g., workstation 140 .
[0023] The call taker workstation 140 answers the call. The call taker workstation 140 may be coupled to a caller id device (not shown) that is capable of obtaining information about the caller based on the caller terminal address. For example, the call signals provided by caller terminal 110 may include a telephone number of the caller terminal 110 . The caller id device may receive this telephone number of the caller terminal 110 and search a database that provides the caller name, address, telephone number, and any other pertinent information.
[0024] In the prior art, as shown in FIG. 1, the call from caller terminal 110 is first handled by one of the level-1 call taker workstations 140 - 160 . During this process, the caller may provide various information regarding the problem or reason of the call to the operator of the level-1 call taker workstation 140 - 160 .
[0025] After interacting with the operator of the level-1 call taker workstation 140 , for example, the operator of the level-1 call taker workstation may determine that the caller needs to be forwarded to a level-2 call taker workstation that is more specialized in handling the particular problem or concern of the caller. At such time, the operator of the level-1 call taker workstation 140 may place the caller on hold and then transfer the caller to a level-2 call taker workstation 170 - 180 .
[0026] After deciding to transfer the call to a level-2 call taker workstation, the operator of the level-1 call taker workstation 140 may enter a summary into a record stored in a computer system associated with the call center 120 . The summary is entered manually using, for example, a keyboard and pointing device, and is stored in a record associated with the call. In transferring the call from the level-1 call taker workstation 140 to a level-2 call taker workstation 170 , for example, the operator of the level-1 call taker workstation 140 may also inform the operator of the level-2 call taker workstation 170 of the record reference number associated with the call so that the operator of the level-2 call taker workstation 170 may review the summary entered by the level-1 call taker workstation 140 operator and other information gathered by the caller id device. The level-2 call taker workstation 170 operator may then retrieve the record using the reference number and continue handling the call.
[0027] In the above system, the caller will typically be required to repeat information provided to the level-1 call taker workstation 140 operator when interacting with the level-2 call taker workstation 170 operator. This is because the summary provided by the level-1 call taker workstation 140 operator usually does not contain enough information and details regarding the call to provide sufficient basis for the level-2 call taker workstation 170 operator to provide assistance. Thus, after having explained their problem to the level-1 support personnel, the caller must again explain the problem to the level-2 support personnel. This can be quite frustrating to the caller as well as costly if the call is not a toll free call. Such repetition extends the time required to handle a call, thereby reducing the number of calls that can be handled as well as increasing the cost of maintaining the call center 120 .
[0028] [0028]FIG. 2 is an exemplary block diagram of a distributed network in which the present invention may be implemented. Elements in FIG. 2 having similar reference numbers as elements in FIG. 1 are intended to refer to similar elements. As shown in FIG. 2, the distributed network system of the present invention augments the system shown in FIG. 1 by providing a speech recognition system 210 in the call center 120 that is coupled to the call director 130 .
[0029] With the system shown in FIG. 2, the handling of a call from a caller terminal 110 by an operator of the level-1 call taker workstation 140 is the same as in the prior art system with regard to the viewpoint of the caller and the operator. However, the level-1 call taker workstation 140 in the system according to the present invention is equipped with a microphone 220 . The microphone 220 is used by the present invention to provide speech input from the operator into the speech recognition system 210 while the operator is handling the call from the caller terminal 110 . The microphone 220 may be a separate device coupled to the call taker workstation or may be a part of the standard telephone hardware used by the operator to conduct a conversation with a caller, e.g., the microphone in a handset of a telephone.
[0030] The capture of the operator speech may be triggered in any manner deemed appropriate to the particular application of the present invention. For example, capturing of the operator speech may be triggered automatically when the operator begins the handling of a call from the caller terminal 110 . Such triggering may be, for example, voice activation of the speech capturing based on speech input received via the microphone 220 . Alternatively, the capturing of speech may be triggered manually by the operator by, for example, pressing a button or key on the level-1 call taker workstation.
[0031] The speech recognition system 210 is preferably trained to recognize words spoken by the particular operator. Training of speech recognition systems is generally known in the art. For example, the IBM ViaVoice™ software, available from International Business Machines, provides speech recognition in which the software is trained to a particular user's speech patterns using a number of predefined training sessions. During these sessions, the user is asked to read various text passages so that the software can “learn” the manner by which the user speaks various words and phrases. The software may then interpret spoken words and transcribe them as text.
[0032] With the preferred embodiment of the present invention, the speech recognition system 210 is trained to recognize the speech of the level-1 call taker workstation operator rather than the caller. Because the speech recognition system 210 is trained for one individual operator rather than attempting to recognize speech from various callers, a more accurate representation of the actual speech may be obtained. If a general speech recognition system were used to try and recognize the speech of hundreds of callers, the likelihood that errors are introduced is quite high.
[0033] Moreover, the speech recognition system 210 may have a vocabulary of recognized words that is limited to specific terminology generally used in the context of the types of problems handled by the level-1 support personnel. For example, if the call center 120 is used to handle technical support problems for a video card product, the vocabulary of the speech recognition system 210 may be limited to terminology generally encountered when discussing problems associated with video cards. Thus, words such as “fluffy,” “creepy,” “sneeze” and the like may be eliminated from the vocabulary of recognized words. This helps shorten the period of time necessary to train the speech recognition system as well as eliminates possible sources of error.
[0034] Of course, while the preferred embodiment of the present invention provides speech recognition for the operator of the level-1 call taker workstation, the present invention is not limited to such an embodiment. Rather, the speech recognition system of the present invention may be used at any level of the call center or multiple levels of the call center. Thus, both level-1 and level-2 support personnel may make use of the speech recognition system of the present invention. Moreover, the speech recognition system may be used to recognize words spoken by the callers. However, as mentioned above, doing so may introduce errors into the descriptions of the problems experienced by the callers.
[0035] In the preferred embodiment, during handling of the call from the caller terminal 110 , the capture of speech is activated. As mentioned above, this may be automatic or manual activation of speech capturing. For example, the operator may determine that the caller has verbally provided information relevant to the purpose of the call and may manually activate the speech capture.
[0036] The operator of the level-1 call taker workstation may then converse with the caller, preferably repeating or summarizing the problem information provided by the caller verbally. In repeating or summarizing the problem information, the operator speaks into the microphone 220 . The operator's speech input is received by the microphone 220 which transmits the speech as signals to the speech recognition system 210 . The speech recognition system 210 interprets the received signals as textual words and outputs the textual words to the call center computer system. The call center computer system may then store the textual words in a record associated with the call as well as provide the textual words as output to the level-1 call taker workstation for verification by the operator. The operator may be provided a mechanism through an interface associated with the level-1 call taker workstation to indicate whether or not to keep or discard the textual words.
[0037] In this way, if the call needs to be transferred to a level-2 specialist, the information stored by the speech recognition system 210 may be displayed to the specialist via his/her level-2 call taker workstation. The speech recognition system 220 or the computing devices of the call center may perform textual analysis of the recognized speech before displaying the information to the level-2 call taker workstation specialist in order to highlight or otherwise accentuate terms in the recognized speech. Similarly, the textual analysis may be used to abridge the recognized speech.
[0038] For example, assume that a caller initiates a call to the call center 120 . The call director 130 routes the call to one of the level-1 call taker workstations 140 . The caller then begins conversing with the operator of the level-1 call taker workstation 140 and describes the problem as: “I installed my video card according to the instructions but I keep getting a blue-screen error with the error code 06:0001:0054 when I try to run an application.” The operator may then repeat the problem statement by saying: “So, what you are saying is that you installed your video card and your computer boots properly but when you try to run an application, you get a blue-screen error code 06:0001:0054.”
[0039] This repetition of the problem statement is stated into the microphone 220 which picks up the voice input and converts it into electrical signals. These electrical signals are then transmitted to the speech recognition system 220 which translates the signals into recognized words based on pattern matching, which is generally known in the art. The resulting recognized speech is then stored in a record associated with the call and may also be output to the call taker workstation for verification.
[0040] When transferring the call to another call taker workstation, the operator may transfer the record of the call as well. This may include pressing a series of keystrokes on the call taker workstation to transfer the call and the call record to a particular other call taker workstation.
[0041] Prior to or during the transfer of the call record, the recognized speech may be analyzed to determine which words in the recognized speech are of importance to the particular other call taker workstation to which it is being transferred. Such a determination may be made based on stored information in the call center 120 identifying the specialty of each of the call taker workstations and/or a vocabulary of important words associated with that workstation. That is, the recognized words stored in the call record may be compared to a vocabulary associated with the call taker workstation to which the call record is being forwarded and any words appearing in both will be highlighted. Of course other mechanisms for displaying the important words in the transcription in a conspicuous manner may be used without departing from the spirit and scope of the present invention. For example, the words of importance may be displayed using a different color text, using a different size font, using a different font, and the like.
[0042] For example, after analysis the above recognized text may be displayed on the level-2 call taker workstation with highlighted text as: “So, what you are saying is that you installed your video card and your computer boots properly but when you try to run an application, you get a blue-screen error code 06:0001:0054.” In this way, the level-2 call taker workstation operator is informed of the problem being experienced by the caller in a manner so as to expedite handling of the call.
[0043] [0043]FIG. 3 is an exemplary block diagram of the speech recognition system according to the present invention. As shown in FIG. 3, the speech recognition system 300 includes a controller 310 , a workstation interface 320 , a speech pattern storage device 330 , a recognized speech analysis device 340 , a control program memory 350 , and a call center interface 360 . These elements 310 - 360 are coupled to one another via the control/data signal bus 370 . Although a bus architecture is shown in FIG. 3, the present invention is not limited to such. Any mechanism may be used that facilitates the exchange of control and data signals between the elements 310 - 360 without departing from the spirit and scope of the present invention.
[0044] The controller 310 controls the overall operation of the speech recognition system 300 and orchestrates the operation of the other elements 320 - 360 . The controller 310 receives speech input from the microphone associated with the call taker workstation via the workstation interface 320 . The controller 310 then performs speech recognition operations on the received speech input based on control programs stored in the control program memory 350 and speech pattern data stored in the speech pattern storage device 330 . The resultant recognized speech may then be stored in a record associated with the call in a storage device of the call center 120 via the call center interface 360 .
[0045] The speech recognition system 300 further includes a recognized speech analysis device 340 which may be used to analyze the recognized speech information to identify important words in the recognized speech. This may include, for example, comparing the words in the recognized speech information to words stored in a vocabulary of important terms. Based on this comparison, a tag may be stored in association with the words in the recognized speech information indicating that the word should be highlighted or accentuated when the recognized speech information is output to a call taker workstation. As mentioned above, this recognized speech analysis device 340 may be present in the speech recognition system 300 or may be part of the call center 120 computing devices, for example.
[0046] It has been stated above that the recognized speech may be stored in a record associated with the call. As mentioned above with regard to FIG. 1, a computer record may be established for a call when a call is received by the call center. This record will have an identifying reference number or tag that allows the record to be retrieved. This reference number or tag may be used to associate the recognized speech with the particular call and store the recognized speech in association with the call record. When the record is to be transferred to another call taker workstation, the record reference number or tag may be forwarded to the call taker workstation which may then retrieve the record and display it accordingly.
[0047] [0047]FIG. 4 is an exemplary diagram of a call taker workstation interface in accordance with the present invention. As shown in FIG. 4, the operator of the call taker workstation is interacting with a caller. In FIG. 4, the field 410 is a visual display of the caller's name and address, e.g., a telephone number, as captured from the network, via a caller-id feature for example. Fields 420 and 430 display product identification data captured in verbal dialog between the caller and the operator and entered by either the operator, an automated touch-tone response system, an HTML form, or the like, or using the speech recognition mechanisms of the present invention.
[0048] Fields 440 and 450 contain information generated within the computer system of the call center to identify the record of the caller's call. These fields 440 and 450 include a ticket number, i.e. a record reference number, and a date/time at which the call was received.
[0049] Field 460 within the workstation interface displays the transcribed text as recognized by the speech recognition system of the present invention. This is a transcription of utterances by the operator of the call taker workstation in response to information received verbally from the caller via the network. The text field displays the transcription itself. Scroll bar 465 permits the operator to review selected portions of the transcription at will.
[0050] The call taker workstation interface shown in FIG. 4 represents the interface provided to both the level-1 and level-2 personnel (as well as any other support level personnel) either when first handling the call or when the call has been handed over to them. The call taker workstation interface permits very efficient transfer of calls to other personnel and minimum need to reacquire problem information from callers via verbal dialog. In this way, the call experience of the caller is quicker and more friendly, thereby reducing caller frustration.
[0051] [0051]FIG. 5 is a flowchart outlining an exemplary operation of the present invention. As shown in FIG. 5, at system startup, the speech recognition system is initialized (step 510 ). This initialization includes commonly-needed functions such as the initialization of variables, the opening of a file for a transcription, and the like. The operator of the call taker workstation logs onto his/her workstation by inputting an appropriate operator identifier (step 520 ). Such log on can be done by typing in an appropriate operator identifier and password for example, by speaking into the workstation microphone and having voice identification software for identifying an operator based on voice input, or any other means by which the operator may identify himself/herself to the call center computing system. In one embodiment, the operator may utter a word or phrase and have the speech recognition system of the present invention attempt to correlate the voice input to stored voice pattern information for each of a plurality of operators to thereby identify the operator.
[0052] Once the operator is identified, the speech recognition system loads speech recognition parameters particular to the specific operator (step 530 ). This may include retrieving voice pattern information from a voice pattern storage device associated with the call center. The voice pattern information may be generated using the training mechanisms described previously.
[0053] Thereafter, a determination is made as to whether the speech recognition functions of the speech recognition system are activated (step 540 ). As mentioned above, the speech recognition functions may be activated manually by the operator or automatically upon receiving a call, for example. If the speech recognition functions are not activated, the operation returns to step 540 and continues to monitor for activation of the speech recognition functions.
[0054] If the speech recognition functions are activated in step 540 , the workstation microphone is enabled and utterances by the operator are recorded and transcribed (step 550 ). The transcription continues until the speech recognition functions are deactivated by the operator or the call terminates (step 560 ).
[0055] Once the speech recognition functions are deactivated, recording and transcription ceases (step 570 ). The operator may then review the transcription and input an indication of confirmation of the transcription (step 580 ). If the transcription is not confirmed, the operator may be provided with an ability to edit the transcription or provide his/her own summary of the reason for the call (step 590 ). If the transcription is confirmed, the transcription is stored in a record associated with the call (step 600 ).
[0056] A determination is then made as to whether the call is to be transferred to another operator (step 610 ). If the call is to be transferred, the identifier for the operator workstation to which the call is to be transferred is received and the call and record reference number are forwarded to the operator workstation identified (step 620 ). If the call is not to be transferred, a determination is made as to whether the call is to be terminated (step 630 ). If the call is to be terminated, the operation ends. Otherwise, if the call is not to be terminated, the operation returns to step 540 and awaits further activation of the speech recognition functions of the present invention.
[0057] Although the above description has been provided in terms of the level-1 operator and level-2 operator are both part of the same support organization, the invention disclosed herein is not limited to such an organization. Rather, the present invention is applicable to all business models without limitation. In one business model, for example, a product manufacturer may employ an independent specialist support service to handle product support of certain kinds requiring specialist training. First level call handling may be provided by the manufacturer himself while call handover is from the manufacturer to the independent support specialist. In this model, the call center is shared by two firms, one which uses it for level-1 support and the other, the specialist support company, retrieves call records from the call center having transcribed information for use in providing level-2 support.
[0058] In an alternative business model in which the present invention may be employed, herein called a “call-broker” business model, the level-1 support is in an independent firm. This firm provides level-1 support and call handover to specialist support, which may be in an independent firm or may be a customer of the call-broker. For example, a product manufacturing firm may have several highly-trained individuals capable of providing level-2 support on a part-time basis. However, the product manufacturing firm may not wish to invest in a call center system such as that described above with regard to the present invention. A second firm, the call-broker, provides the level-1 support and the call center facilities of the present invention for a fee. The second firm need not invest in the expertise necessary to provide level-2 support and the manufacturing firm can concentrate on its core business which is the design, manufacture, and product specific support of its products.
[0059] Although the foregoing description has been written in terms of exemplary embodiments in which call handover is to a support specialist, the present invention is not limited to such. The selective transcription herein disclosed may be applied to any context in which call handover is used. For example, the speech recognition and transcription apparatus and functions of the present invention may be used when transferring calls from a message service to a firm employing the message service, and the like.
[0060] Thus, the present invention provides a mechanism by which verbal information relayed to a human operator may be automatically recorded and transcribed for use by a second operator to which the call is handed off. The present invention reduces the amount of time that the second operator must spend with the caller to ascertain the source of his/her problem or reason for the call as well as reduces the frustration level of the caller by eliminating repetition on the part of the caller. The present invention further limits possible sources of error in describing the problem or reason for the call by providing an automatic mechanism for obtaining a description of the problem or reason rather than relying on a summary generated by a human operator.
[0061] In addition to the embodiments described above, the present invention may be further equipped with a data mining system capable of mining the transcriptions generated by the present invention to identify advice or recommendations for handling the call. The mining of transcription data can be combined with systems capable of planning and giving advice, such as artificial intelligence systems including expert systems, neural networks, rule-based systems, and the like. Artificial intelligence systems are generally taught by Russell et al., Artificial Intelligence, A Modern Approach, Prentice Hall, Upper Saddle River, N.J., 1995, chapter 13 (ISBN 0-13-103805-2), which is hereby incorporated by reference.
[0062] With the present invention, the transcription generated by the speech recognition system identifies the problem or reason for the call. A data mining and advice giving system may access a knowledge base of past problems based on important terms identified in the transcription, identify a similar or related problem, and ascertain a most probable solution to the problem of the present call. The data mining and advice giving system may then inform the operator, via the call taker workstation interface, of the advice and/or recommended solution so that the operator may use this advice and/or recommended solution in handling the call.
[0063] The transcription of problem-specific data as illustrated in the descriptions above, facilitates a mode of business in which this problem-specific data is mined by an off-line process for marketing opportunities. As an example, consider the call taker workstation interface and example field entries shown in FIG. 4. These field entries may be used to hypothesize that the customer has an early model of the product. If a subsequent model has been redesigned so that the problem no longer occurs, a marketing opportunity to upgrade the customer to a newer model exists. In this mode of operation, a marketing specialist could be provided with the transcription and other customer data from call center computing system using a workstation similar to the call taker workstation. Rather than accepting the call, the marketing specialist would originate a call to the customer and discuss the marketing opportunity with him or her.
[0064] It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system.
[0065] The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | An apparatus, system and method for providing speech recognition assist in call handover are provided. With the apparatus, system and method, spoken utterances of the call taker, not the caller, are captured using speech recognition technology and transcribed. The call taker can use a noise-canceling microphone placed optimally to receive voice input from the call taker. The speech recognition system can be trained to the specific speech patterns of the call taker and the vocabulary of the speech recognition system can be limited to the specific domain of discourse related to the job scope of the call taker. The transcription of the spoken utterances of the call taker may be stored in a record associated with the call. This record, and the corresponding transcription, may be transferred to another call taker upon handover of the call to the other call taker. | 7 |
FIELD OF THE INVENTION
The present invention relates generally to semiconductor devices and, more particularly, to metal-oxide semiconductor field-effect transistor (MOSFET) devices with a self aligned damascene gate and methods of making these devices.
BACKGROUND OF THE INVENTION
Scaling of device dimensions has been a primary factor driving improvements in integrated circuit performance and reduction in integrated circuit cost. Due to limitations associated with gate-oxide thicknesses and source/drain (S/D) junction depths, scaling of existing bulk MOSFET devices below the 0.1 μm process generation may be difficult, if not impossible. New device structures and new materials, thus, are likely to be needed to improve FET performance.
Double-gate MOSFETs represent devices that are candidates for succeeding existing planar MOSFETs. In double-gate MOSFETs, the use of two gates to control the channel significantly suppresses short-channel effects. A FinFET is a double-gate structure that includes a channel formed in a vertical fin. Although a double-gate structure, the FinFET is similar to existing planar MOSFETs in layout and fabrication techniques. The FinFET also provides a range of channel lengths, CMOS compatibility, and large packing density compared to other double-gate structures.
SUMMARY OF THE INVENTION
Implementations consistent with the principles of the invention provide FinFET devices that include a damascene gate formed with a self aligned gate mask and methods for manufacturing these devices.
In one aspect consistent with the principles of the invention, a method for forming a metal-oxide semiconductor field-effect transistor (MOSFET) includes patterning a fin area, a source region, and a drain region on a substrate, forming a fin in the fin area, and forming a mask in the fin area. The method further includes etching the mask to expose a channel area of the MOSFET, etching the fin to thin a width of the fin in the channel area, forming a gate over the fin, and forming contacts to the gate, the source region, and the drain region.
In another aspect consistent with the principles of the invention, a method for forming a MOSFET includes forming a fin on a substrate; forming a mask on the substrate; etching the mask to expose a channel area of the MOSFET; thinning a width of the fin in the channel area; and forming a gate over the fin, where the gate extends on each side of the fin.
In yet another aspect consistent with the principles of the invention, a MOSFET includes a fin having a width of approximately 100 Å to 400 Å formed on a substrate, a gate dielectric formed on side surfaces of the fin, and a gate electrode formed covering the fin.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings,
FIG. 1 illustrates an exemplary process for fabricating a MOSFET in accordance with an implementation consistent with the principles of the invention;
FIGS. 2A–6C illustrate exemplary top and cross-sectional views of a MOSFET fabricated according to the processing described in FIG. 1 ;
FIGS. 7A–7C illustrate a process for forming spacers according to another implementation consistent with the principles of the invention;
FIGS. 8A–8C illustrate an exemplary process for removing fin sidewall damage; and
FIG. 9 illustrates an exemplary process for improving mobility of a FinFET device.
DETAILED DESCRIPTION
The following detailed description of implementations consistent with the present invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and their equivalents.
Implementations consistent with the principles of the invention provide FinFET devices that include a self aligned damascene gate and methods for manufacturing these devices. Such FinFET devices have certain advantages. For example, only the active area of the fin is at the minimum channel length, which reduces source/drain resistance. The gate is also self aligned to the minimum channel area, which significantly reduces the parasitic source/drain resistance of the device. In traditional FinFET approaches, the narrow channel is usually significantly longer than the gate length in order to account for gate-to-fin overlay tolerance. Also, the gate patterning is done on a planar substrate (e.g., a polished damascene material), which provides increased lithography margin since the depth of focus of aggressive lithography schemes tends to be quite low. Also, critical dimension variation due to changes in resist thickness over topography (i.e., CD swing0 can be avoided since the resist coating is on a planarized surface.
Exemplary Mosfet
FIG. 1 illustrates an exemplary process for fabricating a MOSFET in accordance with an implementation consistent with the principles of the invention. FIGS. 2A–6C illustrate exemplary top and cross-sectional views of a MOSFET fabricated according to the processing described with regard to FIG. 1 .
With reference to FIGS. 1 and 2 A– 2 C, processing may begin with semiconductor device 200 . As shown in the cross-sectional views in FIGS. 2A and 2B , semiconductor device 200 may include a silicon on insulator (SOI) structure that includes a silicon (Si) substrate 210 , a buried oxide layer 220 , and a silicon layer 230 on the buried oxide layer 220 . Buried oxide layer 220 and silicon layer 230 may be formed on substrate 210 in a conventional manner. The thickness of buried oxide layer 220 may range, for example, from about 1,000 Å to 10,000 Å. The thickness of silicon layer 230 may range, for example, from about 400 Å to 1,500 Å. The silicon thickness may be as thick as possible since increased thickness leads to enhanced width of the device (i.e., more current flow along the sidewall of the fin and thereby higher drive current (in a MOSFET I∝W/L)). Usually it is difficult to use a thick silicon thickness in a conventional FinFET approach since that also leads to a bigger step in the gate lithography step and poor lithography margin.
It will be appreciated that silicon layer 230 is used to form the fin. In alternative implementations, substrate 210 and layer 230 may include other semiconductor materials, such as germanium, or combinations of semiconductor materials, such as silicon-germanium. Buried oxide layer 220 may include a silicon oxide or other types of dielectric materials.
A silicon nitride, or another type of material, may be formed on silicon layer 230 and may function as a bottom antireflective coating (BARC) 240 for subsequent processing, as illustrated in FIGS. 2A and 2B . The thickness of BARC layer 240 may range from approximately 150 Å to 350 Å. A photoresist 250 , or the like, may be deposited and patterned to facilitate formation of a large fin area and the source and drain regions (act 110 ), as shown in FIGS. 2A–2C . Photoresist 250 may be deposited to a thickness ranging from about 1,000 Å to 4,000 Å. FIG. 2C illustrates the top view of semiconductor device- 200 of FIGS. 2A and 2B . The cross-section in FIG. 2A is taken along line X in FIG. 2C and the cross-section in FIG. 2B is taken along line Y in FIG. 2C .
Silicon layer 230 may be etched to form a fin 310 (act 120 ), as shown in FIGS. 3A and 3B . For example, the portion of silicon layer 230 not located under photoresist 250 may be etched with the etching terminating on buried oxide layer 220 . Photoresist 250 may then be removed. The width of fin 310 , as shown in FIG. 3B , may range from approximately 500 Å to 800 Å.
A damascene mask may be formed in the area of fin 310 (act 130 ), as illustrated in FIGS. 3A–3C . For example, a damascene material 320 , such as silicon oxide, silicon nitride, SiCOH, etc., may be deposited over semiconductor device 200 to a thickness ranging from approximately 800 Å to 2,200 Å (to enclose fin 310 and BARC 240 ) and then polished using known techniques, as illustrated in FIGS. 3A and 3B . Damascene material 320 may function as a BARC for subsequent processing. Damascene material 320 may then be etched using a gate mask to expose a channel area 330 in the gate opening, as shown in FIGS. 3A–3C . The width of channel area 330 , as illustrated in FIG. 3C , may range from approximately 300 Å to 500 Å. The gate mask used to expose channel area 330 may be created using aggressive lithography and patterning techniques known to those skilled in the art.
The width of fin 310 may then be reduced (act 140 ), as illustrated in FIGS. 4A–4C . One or more etching techniques may be used to laterally etch fin 310 in channel area 330 . For example, a thermal oxidation of Si followed by a dilute HF dip may be used. Other types of etches may alter natively to be used. For example, Si may be etched in a downstream F plasma where the chemical selectivity of the Si etch in F species over oxide is very high, or a lateral Si etch in HBr based plasma chemistries may be used.
The amount of silicon removed may range from approximately 100 Å to 200 Å per side, as illustrated in FIG. 4B . The resulting width of fin 310 may range from approximately 100 Å to 400 Å. BARC 240 may remain in implementations consistent with the principles of the invention, as illustrated in FIG. 4B . In other implementations, BARC 240 may be removed. FIG. 4C illustrates a top view of semiconductor device 200 after fin 310 has been thinned in channel area 330 .
A gate may then be formed (act 150 ), as illustrated in FIGS. 5A–5C . For example, a gate dielectric material 510 may be deposited or thermally grown on the side surfaces of fin 310 using known techniques, as illustrated in FIG. 5B . Gate dielectric material 510 may include conventional dielectric materials, such as an oxide (e.g., silicon dioxide), silicon oxy-nitride, or high dielectric constant (high K) materials, such as HfO 2 . In other implementations, a silicon nitride or other materials may be used to form the gate dielectric. Gate dielectric material 510 may be formed at a thickness ranging from approximately 10 Å to 20 Å.
A gate electrode material 520 may then be deposited over semiconductor device 200 and polished, as illustrated in FIGS. 5A and 5B . Gate electrode material 520 may be polished (e.g., via chemical-mechanical polishing (CMP)) to remove any gate material over damascene material 320 , as illustrated in FIGS. 5A and 5B . A number of materials may be used for gate electrode material 520 . For example, gate electrode material 520 may include a polycrystalline silicon or other types of conductive material, such as germanium or combinations of silicon and germanium, or metals, such as W, WN, TaN, TiN, etc. Gate electrode material 520 may be formed at a thickness ranging from approximately 700 Å to 2,100 Å, as illustrated in FIG. 5B , which may be approximately equal to the thickness of damascene material 320 (some of which may be lost due to the polishing). FIG. 5C illustrates a top view of semiconductor 200 after gate electrode 520 is formed. The dotted lines in FIG. 5C represent the thinned portion of fin 310 . Gate dielectric layer 510 is not illustrated in FIG. 5C for simplicity.
Source, drain, and gate contacts may then be formed (act 160 ), as illustrated in FIGS. 6A–6C . For example in one implementation, large contact areas may be opened over fin 310 on either side of the gate, as illustrated in FIG. 6A . Source and drain contact areas 610 and 620 may be opened by etching through the extra amount of damascene material 320 left above fin 310 and also removing BARC 240 . Gate contact area 630 may also be formed on gate electrode 520 . It may be possible for these contact areas 610 – 630 to be larger than the actual dimensions of fin 310 and the source/drain.
Silicidation, such as CoSi 2 or NiSi silicidation, can then occur in these openings. The CoSi 2 or NiSi silicidation occurs only where there is polysilicon (i.e., gate) or silicon (i.e., source/drain) and whatever fin region (wide fin) is exposed. The unreacted cobalt or nickel (wherever there is no silicon) can be etched away just as is done in typical self-aligned silicide schemes in use by the industry today.
In another implementation, damascene material 320 and BARC 240 may be removed from the top of fin 310 and the source/drain. Then, a sidewall spacer may be formed on the sides of the gate and fin 310 . Next, a silicide metal, such as cobalt or nickel, may be deposited to form a self aligned silicide wherever there is silicon or polysilicon exposed at the top (i.e., on the gate and on the exposed fin channel).
The resulting semiconductor device 200 , therefore, may include a self aligned damascene gate formed on either side of fin 310 . Fin 310 is thinned in the channel area, as illustrated by the dotted lines in FIG. 6C .
According to another implementation consistent with the principles of the invention, spacers may be formed for the transfer of the damascene gate to make the gate length smaller. FIGS. 7A–7C illustrate an exemplary process for forming spacers according to an alternate implementation consistent with the principles of the invention. As illustrated in FIGS. 7A–7C , a hardmask 710 may be opened ( FIG. 7A ), spacers 720 may be formed ( FIG. 7B ), and the transfer of the damascene gate may be performed in the opening ( FIG. 7C ). The spacer formation inside the damascene gate opening may facilitate printing of small spaces (as mentioned above) in order to form small gate length devices. The spacer technique enables the formation of smaller spaces than may be attained by photolithographic shrinking alone.
In another implementation, damascene gate shrink techniques, such as the ones described in copending, commonly assigned applications entitled, “FINFET GATE FORMATION USING REVERSE TRIM AND OXIDE POLISH” (Ser. No. 10/459,589) (Docket No. H1122), filed Jun. 12, 2003, “FINFET GATE FORMATION USING REVERSE TRIM OF DUMMY GATE” (Ser. No. 10/320,536) (Docket No. H1121), filed Dec. 17, 2002, and “ETCH STOP LAYER FOR ETCHING FINFET GATE OVER A LARGE TOPOGRAPHY” (Ser. No. 10/632,989) (Docket No. H1172), filed Aug. 4, 2003, which are incorporated herein by reference.
In yet another implementation, a metal gate electrode may be used instead of the polysilicon damascene process described above.
Other Implementations
There is a need in the art to remove damage that may occur to the side surfaces (i.e., sidewalls) of a fin during processing. FIGS. 8A–8C illustrate an exemplary process for removing fin sidewall damage. A semiconductor device 800 may include a fin layer 810 and a cover layer 820 formed on a substrate 830 , as illustrated in FIG. 8A . Fin layer 810 may include a semiconductor material, such as silicon or germanium, or combinations of semiconductor materials. Cover layer 820 may, for example, include a silicon nitride material or some other type of material capable of protecting fin layer 810 during the fabrication process.
Fin layer 810 and cover layer 820 may be etched using a conventional dry etching technique to form fin 840 , as illustrated in FIG. 8B . A conventional wet etching technique may then be used to remove fin sidewall damage, as illustrated in FIG. 8C . During the wet etching, the width of fin 840 may be thinned by approximately 20 Å to 40 Å per side. Wet etching of silicon may also result in some buried oxide loss since it is difficult when wet etching to get good selectivity of silicon to silicon dioxide.
There is also a need in the art to improve the mobility of a FinFET device. FIG. 9 illustrates an exemplary process for improving mobility of a FinFET device. A die-attach material may be formed on a package, as illustrated in FIG. 9 . The die-attach material may be selected to induce stress (strain) in the FinFET channel. A die may then be attached to the die-attach material, as illustrated in FIG. 9 . Tensile stress induced in the silicon FinFET channel may result in enhanced hole mobility, which can help significantly improve PMOS FinFET performance. The die-attach material and process may be such that the residual stress in the silicon layer is tensile. For example, if the package material did not shrink as fast as the silicon layer after the (hot) die attach/solder/bump process, then the silicon layer could be in tensile stress when cooled to lower temperatures.
CONCLUSION
Implementations consistent with the principles of the invention provide FinFET devices that include a damascene gate formed with a self aligned gate mask and methods for manufacturing these devices. These FinFET devices have certain advantages. For example, only the active area of the fin is at the minimum channel length, the gate is self aligned to the minimum channel, and the gate patterning is performed on a planar substrate (e.g., a polished damascene material).
The foregoing description of exemplary embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention.
For example, in the above descriptions, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., in order to provide a thorough understanding of implementations consistent with the present invention. These implementations and other implementations can be practiced, however, without resorting to the details specifically set forth herein. In other instances, well known processing structures have not been described in detail, in order not to unnecessarily obscure the thrust of the present invention. In practicing the present invention, conventional deposition, photolithographic and etching techniques may be employed, and hence, the details of such techniques have not been set forth herein in detail.
While a series of acts has been described with regard to FIG. 1 , the order of the acts may be varied in other implementations consistent with the present invention. Moreover, non-dependent acts may be implemented in parallel.
No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. The scope of the invention is defined by the claims and their equivalents. | A method for forming a metal-oxide semiconductor field-effect transistor (MOSFET) includes patterning a fin area, a source region, and a drain region on a substrate, forming a fin in the fin area, and forming a mask in the fin area. The method further includes etching the mask to expose a channel area of the MOSFET, etching the fin to thin a width of the fin in the channel area, forming a gate over the fin, and forming contacts to the gate, the source region, and the drain region. | 7 |
TECHNICAL FIELD
The invention relates to key switch mechanisms used in keyboards and more particularly to the damping of acoustical noise generated by such key switch mechanisms.
BACKGROUND OF THE INVENTION
Key switch mechanisms utilizing buckling compression springs to move a switch actuator in response to the depression of a key are well known in the art and are described in U.S. Pat. No. 4,118,611 to R. H. Harris and U.S. Pat. No. 4,528,431 to E. T. Coleman.
Use of the buckling compression spring enables construction of a low cost key switch mechanism wherein the buckling spring is used to move the switch actuator in response to a force exerted upon a key to depress the key, and wherein the spring restores the key back to the normal position once the downward force is removed from the key. The buckling spring in operating the switch mechanism generates a substantial amount of acoustical noise which grows in intensity and volume almost directly proportional to the speed of the typing by a keyboard operator. Many keyboard operators find the noise irritating and tiring. The noise may disrupt an operator's concentration and may lead to typing errors.
The present invention is an improvement of the key switch mechanism of the aforesaid Harris and Coleman patents in that the acoustical ringing noise generates by the buckling spring is dampened to a point so as not to interfere and disrupt the keyboard operator's concentration.
SUMMARY OF THE INVENTION
In accordance with the present invention, acoustical noise generated by the buckling coil spring in a key switch mechanism is minimized by insertion into an opening formed by the coils of the spring, a cylindrical core formed from a foam type material and positioning it in a predetermined location within the opening in the spring.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of a key switch in its rest position showing a key cap, a switch actuator and a buckling coil spring with a cylindrical core of damping material.
FIG. 2 is similar to FIG. 1 but showing the key switch in its actuated position.
FIG. 3 is a partial enlarged, exploded view of the actuator before assembly.
FIG. 4 is similar to FIG. 3 showing the actuator after assembly.
DETAILED DESCRIPTION
Referring to the accompanying drawing and more particularly to FIG. 1, there is shown a key switch 10 of a keyboard (not shown) which may be used with a personal computer, teleprinter or the like to select one of the characters of the keyboard.
The key switch 10 has a key top or key button 30 which is slidably movable on a hollow cylindrical support 11 of a frame 12. The frame 12 is attached to a metal base 14 which is supported by the keyboard frame (not shown). A membrane contact switch assembly 15 rests on the upper surface of the base 14.
The key top 30 includes a downwardly extending stem 16 extending inside of the upstanding hollow cylindrical support 11 of the frame 12 and being slidably supported thereby. The exterior of the stem 16, which is bifurcated to have two separate skirts 17 (one shown), and the interior of the upstanding hollow cylindrical support 11 have cooperating ribs and slots to orient the key top 30 and to guide it during its vertical motion when it is depressed by a user and then released.
A spring 18 extends between the key top 30 and a pivoting rocking actuator 19, which causes closure of a contact switch 20 of the membrane contact switch assembly 15 when the key top 30 is depressed. The spring 18 has its upper end acting against a mounting base 21 in the stem 16 of the key top 30. The mounting base 21 is angled slightly to set the initial deflection of the spring 18 in a selected direction (to the right in FIG. 2). This is towards the back of the keyboard as an inclined surface 22 of the key top 30 is the front surface of the key top 30. Any sideways buckling of the spring 18 is limited by the skirts 17 of the stem 16 of the key top 30.
The spring 18 has its lower end surround an upstanding post 23 of the pivoting rocking actuator 19 and is attached thereto by a press fit. When the key top 30 is depressed from the position of the FIG. 1 to position of FIG. 2, the force exerted on the key top 30 is transmitted by spring 18 to the actuator 19. At the same time, during the depression of the key top 30, the spring 18 undergoes a catastrophic buckling causing the actuator 19 to pivot about its axis. When the key top 30 is released, the spring 18 unbuckles restoring the key top 30 to its normal position. The catastrophic buckling and unbuckling of the spring 18 generates acoustical noise which can be best described as having two components. The first component is a metallic "click" and the second is a decaying metallic "ring".
It has been experimentally determined that inserting a cylindrical core 26 made of foam material such as closed cell urethane within an opening 25 formed by coils of the spring 18 and positioning the core 26 just above the post 23 attenuates the acoustical noise to a point wherein the decaying metallic "ring" is inaudible and yet the performance of the key switch 10 as perceived by an operator remains the same. The diameter of the cylindrical coil 26 is slightly larger than the diameter of the opening 25 to insure an interference fit between the spring 18 and the core 26 as shown in FIG. 4. The length of the cylindrical core 26 is substantially equal to the diameter of the core. For example, in one implementation of the invention the diameter of the opening 25 of the spring 18 was 0.086", the cylindrical core 26 had a diameter of 0.130" and a length of 0.125". | A key switch utilizing a buckling compression spring to move a switch actuator mechanism includes a cylindrical core of resilient material located within an opening formed by the coils of the compression spring to attenuate the acoustical energy generated by the buckling and unbuckling action of the spring. | 7 |
This application is a continuation-in-part application based on patent application Ser. No. 09/357,036 filed on Jul. 20, 1999now U.S. Pat. No. 6,171,073, which was a continuation-in-part application based on previously filed patent application Ser. No. 08/901,849 filed on Jul. 28, 1997, now U.S. Pat. No. 5,947,700 granted on Sep. 7, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a safety device for fluid transfer systems and, more particularly, to a safety device for eliminating vacuum pressure in the system in response to an obstruction of one or more open intake lines, thereby removing a suction force at the open ends of intake lines in the system.
2. Description of the Related Art
Drowning is the second leading cause of unintentional injury related deaths to children 14 years old and younger. Most drownings occur in swimming pools and hot tubs, and in many incidents (involving both adults and children) the main culprit is the water circulation system. In a typical pool, the circulation system includes a main drain suction intake line and at least one skimmer suction intake line, both of which feed into a main intake line that leads to a pump. A return line directs water flow back into the pool.
Most people do not feel threatened by a pool's circulation system, including the main drain intake on the bottom of the pool, and the skimmer boxes along the side of the pool. However, if a person comes into contact with any of the suction intake lines of the circulation system (at either the main drain or skimmer intakes) causing the suction intake to be covered or obstructed, the immense suction of the pump forms an instant seal between the open end of the suction intake line and the person's skin or clothing. This may result if a person places their hand over the open end of the suction intake line or, as often happens with children, a person sits down on the suction intake. In either case, the force needed to pull them free often exceeds 800 pounds. Moreover, the injuries which are inflicted in a matter of a few seconds are horrific, usually permanent and sometimes fatal. If a person, especially a child, is sucked onto the main drain suction intake on the bottom of the pool, they usually drown.
The only way to free a person sucked onto the intake of a circulation system of this type, without causing severe injury or dismemberment, is to eliminate the vacuum (i.e. negative pressure) in the intake between the entrapped person and the pump, to thereby remove the intense suction force at the open end of the intake line. It is helpful to disable the source of the suction by interrupting power to the pump. However, even if the pump is shut down, a vacuum can remain in the intake side of the system between the pump and the obstructed end of the suction intake line. Sometimes, a victim could still be freed with some assistance, although serious injury or death may result. Ideally, if the vacuum in the intake line can be quickly eliminated after a victim becomes stuck to the intake, the victim will be freed with little or no assistance and without injury.
In the most instances wherein a victim becomes stuck to an intake of a circulation system, typically in a swimming pool or hot tub, rescuers fail to realize the need to immediately shut off the pump. Instead, in a panic, people tend to go the victim and attempt prying them free. In the rare instance this is successful, the injuries are often severe and permanent. Of course, there are also instances wherein there are no other people present to come to the victim's rescue. These situations are almost always fatal.
The imminent danger presented by fluid circulation systems of the type commonly found in swimming pools, hot tubs, and the like has been longstanding in the art. Little, if any attention has been given to providing a satisfactory solution to this deadly problem that exists in every swimming pool, hot tub, as well as all other fluid circulation systems wherein a fluid is drawn from a reservoir through one or more suction intakes by a pump. Accordingly, there has been and there remains an urgent need to provide an effective means of preventing death and injury to those otherwise unfortunate victims who become unexpectedly attached (i.e., entrapped) by suction to the intake of a fluid circulation system.
SUMMARY OF THE INVENTION
The present invention is directed to a device for use in a fluid transfer. and/or circulation system of the type including at least one pump which draws water from a reservoir through one or more intake lines each extending from an open end at the reservoir to an intake of the pump. The primary purpose of the invention is to save lives and property by alleviating the intense vacuum that builds when one or more of the suction intake ports of a pump assisted fluid circulation system becomes obstructed. The safety device includes means for sensing one or more operating conditions in the fluid transfer/circulation system (e.g., negative pressure levels, positive pressure levels, water flow rate, pump voltage and/or amperage) and means for analyzing the sensed operating conditions. When the pump is operating, the safety device continually analyzes the operating conditions of the system. If the device detects a deviation of the operating conditions outside of a normal operational range, the vacuum pressure relief means are actuated in order to eliminate negative pressure in the system, thereby removing suction at the open ends of the intake lines. The device also disables the pump, shutting it off, upon detecting the abnormal operation condition(s). In the event there is an absence of fluid movement when the pump is operating (e.g., broken pipes, reservoir dry, etc.), the device triggers the vacuum pressure relief means and disables the pump, thereby preventing damage to the system. Warning devices, including audible and visible alarms, may be provided to indicate that operation of the fluid transfer system has been interrupted. This is especially useful to alert users to the possible occurrence of an obstruction of the intake lines by a person or object and the need to inspect and reset the device prior to reactivating the fluid transfer system. Other options can also be integrated with the device, including remote audible alarms, visual indicators, a remote panic switch, and the like.
OBJECTS AND ADVANTAGES OF THE INVENTION
With the foregoing in mind, it is a primary object of the present invention to provide a safety device for use in a fluid transfer/circulation system, wherein the device is structured to eliminate negative pressure in the system upon detecting a negative pressure level being outside of a selected operational range, thereby removing suction at the open ends of the intake lines.
It is a further object of the present invention to provide a safety device which is particularly useful in the fluid circulation systems of swimming pools, hot tubs and the like for preventing death and injury to persons or animals which become attached (i.e., entrapped) by suction to the intake openings of the system.
It is still a further object of the present invention to provide a safe, reliable and relatively inexpensive safety device for easy installation to existing fluid transfer/circulation systems and which automatically adjusts to any system, each time the fluid begins to flow, thereby establishing a normal operating range of conditions for each system, and wherein the device is structured to eliminate negative pressure in the system upon detecting an operating condition being outside (high or low) of the normal operating range, thereby removing suction at the open ends of the intake lines.
It is still a further object of the present invention to provide a reliable, relatively inexpensive safety device for use in a fluid transfer/circulation system of the type including at least one pump which draws water from a reservoir through one or more intake lines, and wherein the device is structured to deactivate the pump(s) and to further eliminate negative pressure in the system upon detecting one or more operating conditions of the system being outside of a predetermined range.
It is still a further object of the present invention to provide a safety device, as described above, further including warning devices such as, but not limited to, audible and visible alarms, to indicate that the safety device has been triggered to eliminate negative pressure in the intake lines of a fluid transfer system.
It is still a further object of the present invention to provide a safety device, as described above, which is contained in a totally sealed, compact unit for convenient, easy installation in-line with any fluid transfer/circulation system.
These and other objects and advantages of the present invention are more readily apparent with reference to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a schematic block diagram of the primary components of the safety device in accordance with a first preferred embodiment of the present invention;
FIG. 2 is an elevational view, in partial section, illustrating a typical fluid circulation system for circulating fluid in a reservoir, such as a swimming pool, hot tub or the like, showing the safety device of the embodiment of FIG. 1 installed in-line on a main suction intake line of the system, between the intake of the system's pump and suction intake openings in the swimming pool;
FIG. 3 is a schematic block diagram of the primary components of the safety device in accordance with several other preferred embodiments of the present invention, wherein the sensor may be a positive pressure sensor, a negative pressure (i.e., vacuum pressure) sensor, a fluid flow meter, a voltage meter, or an amperage meter;
FIG. 4 is an elevational view, in partial section, similar to the view of FIG. 2, wherein the safety device includes a positive pressure sensor installed in-line with the return line of the fluid circulation system, on an output side of the pump, in accordance with another embodiment of the invention;
FIG. 5 is an elevational view, in partial section, similar to the views of FIGS. 2 and 4, wherein the safety device of the present invention is shown in accordance with yet another embodiment thereof, wherein a sensor is connected to the pump for measuring the voltage and/or the amperage drawn by the pump during operation thereof;
FIG. 6 is an elevational view, in partial section, similar to the views of FIGS. 2, 4 and 5 , showing the safety device in yet another embodiment thereof, wherein a fluid flow meter is installed in-line with the intake line, between the intake of the system's pump and the suction intake openings in the swimming pool or other fluid reservoir;
FIG. 7 is a cross-sectional view of yet another embodiment of the safety device of the present invention; and
FIG. 8 is an elevational view, in partial section, showing the safety device of the embodiment of FIG. 7 installed in-line on a main suction intake line of a fluid circulation system, between the intake of the system's pump and suction intake openings in the swimming pool or other fluid reservoir.
Like reference numerals refer to like parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to a fluid vacuum safety device for use in a pump assisted fluid circulation system for the purposes of alleviating an intense vacuum that builds in the system when one or more of the suction intake ports of the circulation system become obstructed.
Referring to FIGS. 2, 4 - 6 and 8 , a typical fluid circulation system of the type commonly found in swimming pools and hot tubs is shown. A reservoir of water W is contained within a structure having side walls 2 and a bottom 4 . A main drain 6 having a drain cover grating is provided on the bottom 4 . At least one skimmer box 8 is provided along one or more of the side walls 2 at the water surface level SL. A drain suction intake line 10 leads from the main drain 6 to a main suction intake line 20 . A skimmer suction intake line 12 has an open end 13 is the skimmer box 8 which is maintained below the water surface level SL. The skimmer suction intake line 12 feeds into the main intake line 20 . The main intake line 20 is directed to a pump 24 which may have a screen trap 26 connected to the main intake line 20 , just prior to the intake of the pump 24 . A main output line 28 leads to a filter 30 . One or more return lines 32 extend from the filter 30 back to the water reservoir W to return water that is circulation through the system back to the reservoir W.
FIG. 2 shows the fluid vacuum safety device 50 in accordance with one embodiment thereof installed in-line along the main suction intake line 20 of the circulation system, prior to the intake of the pump 24 and screen trap 26 . If an object or person is caused to be sucked onto one of the open ends of the suction intakes, such as the open end 13 of the simmer suction intake 12 , the drain plate 7 or, if the drain plate is removed, the drain suction intake line 10 at the main drain 6 , a vacuum will instantly develop throughout the intake lines, including the main suction intake line 20 . The fluid vacuum safety device 50 is designed to react to this situation to immediately eliminate the vacuum in the system and, accordingly, the suction force at the open ends of each of the suction intake lines, including the skimmer suction intake 13 and the main drain intake 6 . Upon reaching a predetermined vacuum level, which happens quite rapidly when one of the intakes becomes obstructed, the fluid vacuum safety device 50 causes air from atmosphere to be rapidly introduced into the main intake line 20 and throughout the other intake lines, thereby removing all suction force at the open suction intake ends 13 and 6 in the reservoir W. The air introduced into the system interrupts the prime of the pump 24 , thereby eliminating any further source of suction.
Referring now to FIG. 1, the principal components of the fluid vacuum safety device 50 are shown in block diagram form. Specifically, the principal components of the fluid vacuum safety device 50 include a sensor circuit 120 A which senses the vacuum pressure level in the fluid circulation system. The output of the sensor circuit 120 A is applied to an analyzer/control circuit 130 that allows selective setting (programming) of a particular negative pressure range (a predetermined high and low vacuum pressure level) which thereby defines a trip point (high or low) or emergency condition in the system. The output of the analyzer/control circuit 130 controls operational relays or contactors 150 to interrupt power to the pump 24 and triggers a vacuum breaker 170 upon detecting the trip point. In the preferred embodiment, the analyzer/control 130 is a programmable microprocessor and vacuum breaker 170 is a solenoid controlled valve. A power supply 160 furnishes voltage for the circuitry. The sensor 120 A utilizes a strain gauge to sense the vacuum in the pump return line 20 . The sensor 120 A converts vacuum pressure to voltage readings. Changes in voltage readings correspond directly to vacuum pressure level changes in the system. The voltage readings are amplified in the sensor and sent to the analyzer/control 130 for processing.
Referring to FIG. 3, the principal components of the fluid vacuum safety device are shown in block diagram form in accordance with several additional embodiments thereof. Specifically, the sensor 120 shown in FIG. 3, may include any of a number of different sensors for measuring operating conditions in the swimming pool. In addition to the negative pressure sensor for sensing vacuum pressure level in the fluid circulation system, as described in connection with FIGS. 1 and 2, the sensor 120 may include a positive pressure sensor, a fluid flow meter, a voltage meter/regulator, and/or an amperage meter. The sensor 120 , in accordance with the various embodiments represented by FIG. 3, communicates with the analyzer/control circuit 130 that allows selective setting “programming” of one or more particular operating conditions (e.g., vacuum pressure, positive pressure, water flow rate, pump voltage level and/or pump amperage level) which thereby defines a trip point (high or low) or emergency condition in the system. In several of the embodiments, the analyzer/control 130 is a programmable microprocessor and the vacuum breaker 170 is a solenoid controlled valve. When the analyzer/control 130 determines that the sensed one or more operating conditions, as sensed by the sensor 120 , have deviated outside of a normal operational range (i.e., beyond the trip point), the analyzer/control 130 triggers actuation of the vacuum breaker 170 to introduce air from atmosphere into the intake line 20 of the fluid circulation system, thereby eliminating vacuum in the intake lines and further eliminating suction at the open intake ends 6 , 13 within the reservoir W.
Referring to FIG. 4, the safety device 50 is shown installed in accordance with one preferred embodiment, wherein the safety device 50 includes a positive pressure sensor 120 B installed in-line along the return line 32 , between the output side of the pump 24 and the reservoir W. In this particular embodiment, the positive pressure sensor 120 B is structured to measure the positive pressure in the return line 32 when the pump 24 is operating. A normal operational positive pressure range is established and is maintained in memory in the analyzer/control 130 . In the event the positive pressure measured in the return line 32 deviates outside of a normal operational range, the analyzer/control 130 triggers the vacuum breaker 170 to introduce air into the main intake line 20 . The analyzer/control 130 is also structured to interrupt power to the pump 24 to thereby terminate operation of the pump 24 .
Referring to FIG. 5, the safety device 50 is shown in yet another embodiment of the invention, wherein the sensor 120 C is adapted to read voltage and/or amperage levels of the pump during operation thereof. A normal voltage and/or amperage operating range for the pump is determined and is stored in the microprocessor memory of the analyzer/control 130 . Should the voltage and/or amperage level drawn by the pump 24 deviate outside of the normal operational range, the analyzer/control 130 will trigger actuation of the vacuum breaker 170 to introduce air from atmosphere into the return line 20 , thereby relieving suction at the open intakes 13 and 6 within the reservoir W.
Referring to FIG. 6, the safety device 50 is shown installed in a fluid circulation system of a swimming pool, in yet another embodiment of the invention, wherein a fluid flow meter 120 D is installed in-line on the main intake line 20 of the system. The fluid flow meter 120 D is another type of sensor contemplated within the spirit and scope of the invention. In this particular embodiment, the analyzer/control 130 is programmed to store a normal operational range of water flow rates of water traveling through the main intake line 20 leading to the intake of the pump 24 when the system is operating normally. Should the water flow rate deviate outside a normal operational range, as sensed by the fluid flow meter 120 D, the analyzer/control 130 triggers actuation of the vacuum breaker 170 to introduce air into the intake lines, thereby relieving suction at the open ends 6 , 13 within the reservoir W.
Referring to FIGS. 7 and 8, yet another embodiment of the safety device 50 is shown, in accordance with a purely mechanical embodiment thereof. Specifically, the safety device 50 in the embodiment of FIGS. 7 and 8 includes a base unit 52 defined primarily by an inverted T-section formed of PVC and having a main through passage 54 defined along the bottom of the inverted T and having opposite open ends 55 , 55 ′ which connect in-line to the main intake line 20 , as seen in FIG. 8 . During normal operating conditions, water flow will travel in a direction of the arrow 56 and through conduit 54 towards the pump 24 . The inverted T section of the base unit 52 further includes an upwardly extending vent port 60 extending upwardly from the through passage 54 , in fluid communication therewith, to a top end 62 . The open top end 62 is surrounded by an annular flange 64 having an O-ring seal 67 fitted to a top face of the flange 64 .
A membrane 70 rests on the O-ring 67 in covering relation to the open top 62 of the vent port 60 . The membrane 70 may be structured of a frangible material, such as a glass or plastic film which is structured to break in response to a predetermined negative pressure level. Specifically, the thickness of the central zone 74 of the frangible membrane 70 may be determined in accordance with the shattering or disintegrating characteristics of the membrane material. More particularly, the thickness of the central zone 74 of the frangible membrane 70 may be gauged according to the desired predetermined vacuum pressure level at which the frangible membrane is caused to implode and disintegrate.
Alternatively, the membrane 70 may be structured and disposed to move or collapse, such as against a spring force, to introduce air into the through passage 54 and main intake line 20 , in response to a vacuum pressure level within the intake line 20 deviating beyond a predetermined maximum level.
Once the membrane 70 is caused to disintegrate, move or otherwise uncover the open top end 62 of the vent port, air from atmosphere is able to quickly enter through the open top to fill the intake lines of the fluid circulation system (as indicated by the arrow 76 ) thereby eliminating the vacuum in the system and relieving suction at the open intake end within the reservoir W.
The membrane 70 is maintained in place, in covering relation to the open end 62 , by a fitting 80 having a lower annular face 82 which opposes the flange 64 , sandwiching the rim 72 of the membrane 70 therebetween, as seen in FIG. 7 . The O-ring 67 absorbs pressure to prevent the membrane 70 from cracking as the fitting 80 is advanced and tightened towards the flange 64 and against the rim 72 of the membrane 70 . A female coupling 84 is provided to facilitate attachment of the fitting 80 to the base unit 52 , enabling threaded advancement and withdraw of the fitting 80 relative to the flange 64 and the membrane 70 . Threads 85 about the outer periphery of the fitting 80 intermesh with corresponding threads 86 on the inner face of the female coupling 84 . An inwardly directed flange 87 on the lower open end of the female coupling 84 engages the under side of the flange 64 of the vent port. The fitting 80 further includes a flat ledge 88 which proceeds inward to a reduced diameter extension 89 . The fitting 80 is open at both the opposite ends and has a larger diameter between the annular face 82 compared to a top open end 90 . The ledge 88 on the fitting is provided with a plurality of air inlet holes 94 which extend from the top ledge 88 through the thickness of the fitting 80 to provide air flow communication between the exterior atmosphere and an inner chamber 96 above the frangible membrane 70 . When the membrane 70 is caused to uncover the open end 62 of the vent port 60 , air from atmosphere enters through the inlet holes 94 and through the top opening 62 of the vent port 60 and throughout the suction intake lines of the system to eliminate vacuum therein. A cap 102 is fitted to the reduced diameter extension 89 to cover the open top end 90 .
While the instant invention has been shown and described in accordance with preferred embodiments thereof, it is recognized that variations, modifications and changes may be made to the instant disclosure without departing from the spirit and scope of the invention, as set forth in the following claims and within the doctrine of equivalents. | A safety device for use in a fluid transfer and/or circulation system of the type which uses a pump to draw water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The safety device connects to the fluid transfer/circulation system and includes a sensor, a triggering mechanism, and a vacuum breaker. When the pump is operating, the sensor monitors one or more conditions of the system. When one or more of the monitored conditions deviates outside of a normal operational range, as a result of an obstruction of any one or more of the open ends of the intake lines, the triggering mechanism triggers the vacuum breaker to eliminate negative pressure in the system by introducing air from atmosphere into the intake lines, thereby removing suction at the open ends of the intake lines. The safety device may further activate warning devices including audible and visible alarms to indicate that the system has been deactivated. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to molded plastic articles such as clothespins for suspending laundry from such as a clothesline, or multipurpose clamps such as bag clips, hobby clamps or ice tongs.
2. Description of Related Art
Wooden clothespins of the unitary simple split type and of the double jaw, spring-loaded type are well known.
However, the wood in both types is subject to rot and deterioration and the springs of the springloaded type are subject to rust and easy breakage, twist and disassemble and pinch the user.
Molded plastic clothespins and clamps are also available.
However, most are expensive or complicated in their construction and unreliable in their use and, when used as clothespins, allow the articles which they are intended to hold suspended from such as a clothesline to fall to the ground or floor.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to provide a simple, inexpensive reliable, unitary, clothespin or multipurpose clamp which may be molded as an integral unit fabricated from a resilient plastic.
Another object is to provide such a clothespin or multipurpose clamp having a hairpin like configuration to include a loop allowing its suspension from a line or the like and a pair of pivotally related jaws which may be moved between a gripping,confronting position wherein the jaws are in contact with one another and an open position wherein the jaws are separated by the application or release of a squeezing pressure on the loop.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a top plan view of the Clothespin or multipurpose clamp of the invention in an opened, or non-use position;
FIG. 2 is a bottom plan view of the Clothespin or multipurpose clamp of FIG. 1;
FIG. 3 is a top plan view of the Clothespin or multipurpose clamp of the invention in a closed, or use position;
FIG. 4 abottom plan view of the Clothespin or multipurpose clamp of FIG. 3;
FIG. 5 aside elevational view of the Clothespin or multipurpose clamp of FIG. 1, the opposite side being a mirror image;
FIG. 6 is an end elevational view as seen from the top of FIG. 1;
FIG. 7 is an end elevational view as seen from the bottom of FIG. 1;
FIG. 8 is an end elevational view as seen from the top of FIG. 3;
FIG. 9 is an end elevational view as seen from the bottom of FIG. 3;
FIG. 10 is a cross sectional view taken on line 10 — 10 of FIG. 1;
FIG. 11 is a cross sectional view taken on line 11 — 11 of FIG. 2;
FIG. 12 is a cross sectional view taken on line 12 — 12 of FIG. 3;
FIG. 13 is a broken top plan view of the Clothespin or multipurpose clamp of the invention laid flat to illustrate its inner planar face;
FIG. 14 is a top plan view of the Clothespin or multipurpose clamp of the invention in a closed, or use position, with the lower jaws spread apart and ready to accept clothes to be hung; and
FIG. 15 is a bottom plan view of the Clothespin or multipurpose clamp of FIG. 14 .
DETAILED DESCRIPTION OF THE INVENTION
A clothespin, or multipurpose clamp embodying the invention, generally indicated by the numeral 10 , is fabricated from a resilient plastic material such as high impact polystyrene or the like.
As shown in FIG. 13, clothespin or multipurpose clamp 10 is molded to provide an elongated, substantially rectangular integral unit having a substantially flat, outer face 12 and an inner face 14 which has a flat, central main body portion 15 , a first raised portion 16 extending inwardly from one of its free ends and communicating with one end of main body portion 15 , and a second raised portion 18 extending inwardly from its opposite free end and communicating with the opposite end of main body portion 15 .
First raised portion 16 includes, adjacent its outer end, a pair of spaced, parallel rounded projections 20 and 22 which extend across inner face 14 and are separated by a rounded depression 24 .
First raised portion 16 also includes, adjacent its inner end and one end of main body portion 15 , a combination locking/pivot member 26 having an annular crowned head 28 which extends across approximately one-half the width of inner face 14 and has an integral locking/pivot pin 30 disposed centrally thereof.
Locking/pivot pin 30 extends from a flat inner face 31 of crowned head 28 across inner face 14 of the clothespin and is split for a portion of its length as at 32 for purposes to appear.
A semi-circular depression 34 is provided in raised portion 16 immediately below locking/pivot pin 30 , also for purposes to appear.
Second raised portion 18 includes adjacent its outer end, a series of spaced, parallel, alternating rounded projections 36 and 38 and rounded depressions 40 and 42 which extend across inner face 14 .
Second raised portion also includes, adjacent its inner end, and the opposite end of main body portion 14 , an annular hub 44 which extends across approximately one-half the width of inner face 14 .
Hub 44 has a flat inner face 45 and is provided with a central through bore 46 of a diameter complemental to the outer diameter of locking/pivot pin 30 on locking/pivot member 26 of first raised portion 16 .
A semi-circular depression 47 is provided in raised portion 18 immediately adjacent hub 44 , also for purposes to appear.
In use, the opposite free ends of the clothespin or multipurpose clamp are grasped and raised portions 16 and 18 thereof are brought into a confronting, face-to-face relation, with main body portion 15 now having a curved configuration to form a loop 17 wherein the clothespin or multipurpose clamp assumes a hair-pin like or inverted U-shape as shown in FIGS. 1-4, and FIGS. 14 and 15.
At this time, the clothespin or multipurpose clamp now may be suspended from a clothesline C, or the like, with inner face 14 of main body portion 15 and loop 17 resting on the clothesline.
Raised portions 16 and 18 now may be inter-engaged, by being moved from the positions of FIGS. 1 and 2 to the positions of FIGS. 3, 4 , 14 and 15 .
Body portions 16 and 18 are interengaged by deflecting raised portion 18 to a position behind raised portion 16 , exerting an inward pressure on outer face 12 in the direction of the arrows a so as to bring locking/pivot pin 30 of locking/pivot member 26 into alignment with through bore 46 of hub 44 and pressing with the fingers on the outer surfaces of crowned head 28 of raised portion 16 and hub 44 of raised portion 18 to snap locking/pivot pin 26 into through bore 46 , with split 32 in pin 26 permitting compression of the pin for easy passage through the bore.
Body portions 16 and 18 may be separated by simply reversing the above noted procedure.
In the closed configuration of FIGS. 3 and 4, hub 44 is disposed in semi-circular depression 34 of raised portion 16 , annular crowned head 28 is disposed in semi-circular depression 47 of raised portion 18 , and the flat inner faces 31 and 45 of crowned head 28 and hub 44 respectively are resting against each other as shown in FIG. 12, with raised portions 16 and 18 now forming confronting faces of a pair of pivotally interrelated jaws 48 and 50 for firmly gripping miscellaneous items.
In the closed configuration of FIGS. 3 and 4, rounded projections 20 and 22 of raised portion 16 of jaw 48 are pressing firmly against the inner face of raised portion 18 of jaw 50 with rounded projection 20 being disposed immediately above rounded projection 36 of portion 18 , and with rounded projection 22 pressing into rounded depression 42 of raised portion 18 .
With the clothespin or multipurpose clamp in the closed position of FIGS. 3 and 4, the lower ends of jaws 48 and 50 may be opened or spread apart as shown in FIGS. 14 and 15 by applying a squeezing pressure to outer face 12 at pressure points b and c immediately above raised portions 16 and 18 respectively of the jaws to deflect loop 17 inwardly causing the lower ends of the jaws to move outwardly as the raised portions 16 and 18 pivot relative to each other relative to locking/pivot pin 30 .
When such squeezing pressure is released, the jaws return automatically to their closed, confronting positions. | A unitary clothespin or multipurpose clamp molded from a resilient plastic material having a hair-pin like configuration comprising a loop for permitting suspension, the loop terminating in a pair of confronting gripping jaws, the jaws being releasably, and pivotally interconnected and being movable between a closed, gripping position in contact with each other and an open, nongripping position not in contact with each other upon the application or. release of a squeezing compressive force upon the loop. | 3 |
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
BACKGROUND OF THE INVENTION
This invention relates to polymers, and in particular to p-benzobisoxazole, p-benzobisthiazole and p-benzobisimidazole polymers which contain 2,6-naphthalic segments.
Considerable research efforts in recent years have been directed toward the synthesis of extended chain or rod-like polymers. The unique ordering properties of these polymers into liquid crystalline solutions has led to the preparation of extremely high modulus/high strength fibers.
It is an object of the present invention to provide novel p-benzobisoxazole, p-benzobisthiazole and p-benzobisimidazole polymers.
It is another object of the present invention to provide novel monomers useful in preparing the above polymers.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following disclosure.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a novel polymer having repeating units of the general formula ##STR2## wherein BB is ##STR3## Y is ##STR4## Z is ═NH, --O-- or --S--, R is --H or a C1 to C3 alkyl group, and Q is --O-- or --S--.
Also provided in accordance with the inventions are novel monomers having the formula ##STR5## wherein Y is as described above.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment, the invention resides in novel 4,8-disubstituted-2,6-naphthalene dicarboxylic acid monomers. These monomers are prepared as illustrated by the following equations: ##STR6## In the foregoing equations, R and Y are as described previously.
Nitration of the naphthalene dicarboxylic acid ester as shown in equation (1) is conventional. It is known in the art that aromatic compounds can be nitrated using a mixture of sulfuric and nitric acids. The di-nitrated product is isolated by conventional techniques.
The dinitro dicarboxylate product (II) is reacted with an aromatic or heterocyclic phenol as shown in equation (2) in a suitable solvent, such as, for example DMSO, in the presence of a suitable weak base, such as, for example, potassium carbonate. The reactants and the weak base are added to the desired solvent in a suitable container, and heated to reaction temperature, generally about 75° to 150° C. with stirring for about 5 to 50 hours. Reaction onset and progress may be monitored by suitable means, such as by TLC. The diester (III) is hydrolyzed to the diacid (IV) by conventional techniques.
The polymers of this invention are prepared by the polycondensation of 4,6-diaminoresorcinol dihidrochloride, 2,5-diaminohydroquinone dihydrochloride, 4,6-diamino-1,3-benzenedithiol dihydrochloride, or 2,5-diamino-1,4-benzenedithiol dihydrochloride or 1,2,4,5-tetraaminobenzene tetrahydrochloride and one of the difunctional naphthenic monomers discussed above. The condensation reactions involved are illustrated by the following equations ##STR7## In the foregoing equations, Z and Y are as defined previously.
In conducting the process, the diamino dihydrochloride monomer is mixed with polyphosphoric acid. The mixture is heated, under vacuum or an inert gas atmosphere to about 70° to 130° C. over a period of about 3 to 4 hours, to dehydrochlorinate the diamino monomer. At the end of this period, the difunctional naphthenic monomer is added. An additional amount of phosphorous pentoxide and/or PPA may be added as required to provide a stirrable mixture. An equimolar amount of the naphthenic monomer as compared to the diamino monomer is generally used. The amount of PPA used is that which is sufficient to provide a stirrable mixture. In general, the concentration of monomers in the acid usually ranges from about 0.5 to 12.0 percent.
The reaction mixture is heated at a temperature in the range of about 75° to 225° C. for a period ranging from 24 to 96 hours. Preferably, the polymerization is carried out by stages, i.e., a step-wise heating schedule is employed. Step-wise heating is preferred because immediately exposing the reaction mixture to relatively high polymerization temperatures may cause decomposition of the monomers. The selection of a particular step-wise heating schedule is obvious to one of ordinary skill in the art. At the end of the reaction period, the polymer solution is in a very viscous or semi-solid state. After cooling, the product is washed repeatedly with water while stirring, after which it is dried under a high vacuum at an elevated temperature.
The molecular weight of these polymers is commonly indicated by the inherent viscosity of the polymer. The inherent viscosity is commonly determined at a concentration of 0.2 weight/volume percent in methanesulfonic acid at 25° C.
The polymers produced in accordance with the process of the present invention may be used to produce fibers and sheets. In order to form these polymers into fibers or sheets, dopes are prepared containing about 5 to 15 weight percent of the polymer in a strong acid, such as sulfuric acid, methanesulfonic acid, chlorosulfuric acid, and the like, including mixtures thereof. Such dopes may be spun or extruded into a coagulation bath comprising water or a water/methanesulfonic acid mixture.
The following examples illustrate the invention:
EXAMPLE I
4,8-di(m-phenoxyphenoxy)-2,6-naphthalene dicarboxylic acid
To a 3-neck flask equipped with stirrer, nitrogen inlet/outlet tubes and condenser was added 40.0 g (0.22 mole) of m-phenoxyphenol, 50.0 g of anhydrous potassium carbonate and 200 ml of DMSO. The mixture was stirred and heated in an oil bath under nitrogen for 30 min., after which, 25.0 g (0.075 mole) of 4,8-dinitro-2,6-dimethyl naphthalene dicarboxylate was added. The reaction, as monitored by TLC in methylene chloride solvent was found to begin at 85° C. and progressed to completion at this temperature in 24 hours. The reaction mixture was then cooled, added to water and extracted with toluene. The impure product from the toluene extraction was column chromatographed twice using methylene chloride as the elutant. Yield: 5.8 g (12.6%). mp 162°-4° C.
Analysis Calc'd for C 38 H 28 O 8 : C, 74.50; H, 4.61. Found: C, 74.04; H 4.64.
To a 1-liter flask containing 500 ml of 4% KOH solution was added the dicarbonoxylate obtained above. The mixture was heated to reflux, with stirring, until a clear solution was obtained. The hot solution was treated with charcoal, filtered and then acidified with HcL to provide 2.0 g of the diacid, which was then recrystallized from DMAC.
Analysis Calc'd for C 36 H 24 O 8 : C, 73.97%; H, 4.14%. Found: C, 73.54%; H, 4.15%.
4,8-di(p-phenoxyphenoxy)-2,6-naphthalene dicarboxylic acid, 4,8-di(m-pyridyloxy)-2,6-naphthalene dicarboxylic acid and 4,8-diphenoxy-2,6-naphthalene dicarboxylic acid were synthesized generally following the procedure given above.
EXAMPLE II
A slurry of 0.8532 g (0.0035 mole) of 2,5-diamino-1,4-benzenedithio dihydrochloride and 4.6 g of 85% polyphosphoric acid was stirred under vacuum at 85° C. until the solution became clear; indicating completion of dehydrochlorination. 1.40 g (0.0035 mole) of 4,8-di(m-pyridyloxy)-2,6-naphthalene dicarboxylic acid was added to the solution and the resultant mixture heated under nitrogen at 85° C. for 3 hours with stirring. The mixture was cooled to about 50° C., then 7.80 g of P 2 O 5 was added. The reaction mixture was then heated under nitrogen with stirring to 90° C. for 3 hours, followed by heating to 170° C. for 24 hours. The polymer was precipitated out in water. Yield: 1.63 g. Inh. visc. 2.25 dl/g.
Analysis Calc'd for (C 28 H 14 N 4 S 2 O 2 ): C, 66.91; H, 2.81; N, 11.15; S, 12.76, Found: C, 63.79; H, 2.71; N, 10.77; S, 12.70.
Various modifications may be made without departing from the spirit of the invention or the scope of the appended claims. | A polymer having repeating units of the general formula ##STR1## wherein BB is a benzobisaxazole, benzobisthiazole or benzobisimidazole group and Y is a phenolic, pyridyl or phenoxyphenyl group. | 2 |
BACKGROUND AND PRIOR ART
The invention relates to apparatus for converting gaseous or liquid fuel energy to mechanical and/or electrical energy.
The apparatus is based on the observation by the inventor that a plasma formed of hot burning gases can be turned into a double vortex with one part of the vortex rotating in an outer cylindrical stratum of a rapidly rotating, axially moving plasma mass, which by suitable means as explained in more detail in the present disclosure, can be formed into a double vortex having an inner vortex rotating in a cylindrical stratum inside the aforesaid outer cylindrical stratum, and wherein the gas plasma in the inner vortex is rotating at considerably greater speed of rotation in the same rotational direction as the outer vortex, but in opposite axial direction. The process of turning the outer vortex into itself, so to speak, has been named a "sustained implosion", which term shall be used in the following description, which discloses energy converting apparatus based on the principle of sustained implosion technology.
To more readily understand the phenomenon of sustained implosion it should be understood that a sustained implosion is formed by injecting, by suitable means, hot burning gases into a cylindrical chamber, in the following termed an exhaust chamber, in such a manner that the burning, still expanding gases enter one end of the cylindrical exhaust chamber in an outer spiral-shaped trajectory following the inward facing surface of the chamber. The burning gases are reflected from an opposite suitably curved end wall of the chamber, to again traverse the chamber in an inner spiral-shaped trajectory moving axially in opposite direction of the outer trajectory. Due to the continued combustion of the burning gases, the temperature increases as gases keep expanding while at the same time the rotational speed of the gases increase considerably. Due to the high rotational velocity and the resulting radial gravity gradient, the hot burning plasma separates with its lighter particles concentrating at the axis of the exhaust chamber and the heavier particles at its perimeter. The separation of the lighter and heavier particles also create opposite electrical polarities resulting in an electric charge of one polarity forming on the cylindrical wall of the combustion chamber and an electrical charge of the opposite polarity forming on conducting structures disposed along the axis of the cylindrical wall. These charges can be tapped off by suitable conducting means and converted to usable electric power in a power converter.
The sustained implosion in the form of highly heated, high velocity imploding vortex combustion is further enhanced by ionizing the fuel within an ionizing chamber prior to combustion. The ionizing chamber is located at the center of the vortex. The combustion chamber is constructed so as to stratify all molecular and atomic particles by particle mass. The flow patterns operate to trap the heavier particles in the very hot pressure regions so as to force them into giving up their kinetic energy in their inertial mass before they escape from the system, and then to return these lighter gases to a low pressure in the central core that subsequently causes a repetition of the cycle. The plasma combustion produces great quantities of free electrons that associate and exchange within the highly heated stratified gas particles in such a manner so as to separate into particles of heavier masses and lighter masses, with the gases containing large quantities of ionized particles, including electrons and small quantities of ionized electrons, stratification by mass and polarization by orbit, and great variation of electrical potentials.
The technology of forming a vortex in a burning mass of gases for the purpose of more intimately mixing fuel and air in order to attain more complete combustion is per se known from the prior art. As examples, U.S. Pat. No. 4,507,075 shows a combustion device using vortex technology to improve the combustion of coal dust. U.S. Pat. No. 4,351,251 shows combustion apparatus with two oppositely moving vortices. U.S. Pat. No. 4,144,019 shows a vortex burner with two vortices separated by an intermediate cylindrical wall, and U.S. Pat. No. 3,958,915 shows a method of burning heavy oil in a two-stage combustion process with exhaust gas recirculation.
None of the prior art, however, shows the use of a double vortex, i.e. a sustained imploding vortex to generate electric energy, nor to be used as an adjunct to a gas turbine to enhance the efficiency of the turbine. It is accordingly an object of the instant invention to provide apparatus in the form of a gas turbine to produce electric energy and/or simultaneously produce shaft energy.
SUMMARY OF THE INVENTION
An energy converting apparatus is provided for converting liquid or gaseous fuel to electrical and mechanical energy, including an exhaust chamber with external walls and an exhaust port; one or more gas turbine rotors in the exhaust chamber, with a central air inlet, a fuel inlet, and a plurality of tangentially oriented exhaust cone ports. The exhaust gases from the exhaust cone ports are ejected into the exhaust chamber wherein they form a sustained spiral-shaped imploding vortex of swirling burning gases. Air compressor means are provided for supplying air into the air inlet; fuel delivery means are provided for supplying fuel into the fuel inlet; an inwardly curved end wall in the exhaust chamber serves for receiving and reflecting exhaust gases ejected from the exhaust gas ports and sustaining the imploding vortex. The imploding vortex is reflected back from the curved end wall as an inner spiral-shaped vortex. The imploding vortex forms electric charges on the external walls and the exhaust gases are ejected from the exhaust gas ports to turn the turbine rotor. Electrical take-off means are provided for taking off the electrical charges as electrical energy.
The energy converting apparatus according to the invention includes a fuel-air mixing chamber in the turbine rotor, which fluidly communicates with the central air inlet, the fuel inlet, and the exhaust gas inlet. A plurality of combustion chambers are fluidly communicating with the mixing chamber, a plurality of tangentially outward facing exhaust cones having inlets fluidly communicating with the combustion chambers, and combustion outlets terminating the exhaust cones. Electric ignition means are connected with the combustion chambers for igniting the fuel-air mixture in the combustion chambers.
The energy converting apparatus according to the invention further includes an electric ignitor in each combustion chamber and a spark generator coupled to the ignitor, in the ignition means.
The energy converting apparatus according to the invention may further include a hollow shaft coupling the air compressor means with the turbine rotor, the hollow shaft having a hollow interior fluidly coupling the air compressor means with the turbine rotor air inlet.
According to a further feature, the energy converting apparatus includes a planar end wall opposite the curved end wall in the exhaust chamber, an opening in the planar end wall for receiving the hollow shaft, and bearing means in the planar end wall for supporting the hollow shaft, and it may further include a shroud enclosing the exhaust chamber forming an air space between the shroud and the outer wall of the exhaust chamber; a plurality of air intake openings at one end of the shroud and a plurality of air outlet openings at an opposite end of the shroud; and air intake means in the air compressor means fluidly communicating with the air outlet openings. The air space operates to preheat air being drawn into the air intake means of the compressor means.
According to another feature, the energy converting apparatus includes a high-voltage converter having a high voltage input connected to the electric take-off means, a low-voltage output for delivering low voltage energy from the high-voltage converter, an electric motor having an electric input connected to the low-voltage output, an external motor shaft, and a rotating shaft connected to the holoow shaft via the compressor rotor for receiving rotary energy from the turbine rotor.
According to still another feature, the energy converting apparatus includes reduction gear means between the motor shaft and the rotating shaft for matching the rotary speeds of the rotating shaft and the motor shaft, a first electric insulator for electrically insulating the external walls of the exhaust chamber from the planar end wall, and a second electric insulator for insulating the external walls of the shroud from the exhaust port.
According to yet a further feature, the converting apparatus includes a liquid fuel line for supplying liquid fuel, a heat exchanger having an outlet connected to the liquid fuel line for converting the liquid fuel into vapor fuel, and an ionization chamber connected to the heat exchanger outlet for receiving the vapor fuel and ionizing the vapor fuel.
The energy converting apparatus according to the invention may further include a fuel injector connected to the ionization chamber, disposed in the fuel inlet of the turbine rotor for injecting vapor fuel into the mixing chamber, an electric heating element in the heat exchanger, the heating element including a porous metallic heating body, and electric connection means for connecting the porous heating body to an electric power source for vaporizing liquid fuel traversing said porous heating body.
The energy converting apparatus according to the invention includes a compressor rotor mounted on the rotating shaft, a compressor air inlet, a compressor air outlet fluidly communicating with the air inlet of the turbine rotor via the hollow shaft, a plurality of radially extending rotor blades on the compressor rotor for radially compressing air into the compressor air outlet. Or the compressor may have a plurality of inward slanted air scoops peripherally disposed on the compressor rotor for radially inwardly compressing air into the compressor air outlet, or alternatively a plurality of radially extending axially slanted rotor blades on the compressor rotor for axially compressing air into the compressor air outlet.
The invention further includes apparatus for implementing a method to preheat and to completely vaporize the incoming fuel by the use of a fuel ball located close to, or in the middle of the imploding exhaust chamber, and dispersing and intimately mixing a vaporized fuel into the power turbine rotor so as to premix it with the superheated air prior to delivery to individual combustion chambers located on the periphery of the rotor, and further to ionize the fuel and combustion air with a surplus of electrons produced by the plasma of the combustion cycle by insulating the exhaust chamber from the power turbine rotor.
The invention further includes apparatus and a method of preconditioning the fuel by superheating and ionizing the fuel and air molecules in such a manner as to cause the fuel to produce a much hotter combustion than is commonly produced in other systems, and producing a plasma combustion cycle by preheating and ionizing the fuel and combustion air and causing their molecules to oxidize and so react with each other within an imploding vortex cycle.
The invention further includes a method of delivering liquid fuel and/or preheated fuel with a conventional spray nozzle to a vacuum in the vortex center that will cause the fuel to flash into a vaporized steam by the principle that a liquid fuel, when sprayed into a vacuum will easily vaporized and will then immediately co-mingle with the preheated incoming air of the expanding vortex located within the power turbine disc.
The invention also includes apparatus and a method of sratifying by molecular and atomic weight the combusting fuel and exhaust molecules in such a manner as to cause the heavier and hotter reacting molecules to be progressively located at the outer periphery of the imploding vortex of the exhaust chamber and the lighter molecules and particles to progressively be located toward the center of the imploding vortex, wherein long chain molecules of a combusting air fuel mixture are stripped of their electrons by inducing a plasma from the combustion cycle, stratifying the electrons within the imploding electron gas that is produced by the plasma in such a manner that the lighter elements of the plasma exhaust are recycled by the use of slots, scoops or openings to the low pressure center of the power turbine rotor so as to reassociate these elements with the incoming fuel air mix. This causes a recycling of the combustion and reacting elements, causing a disassociation of the polluting elements normally associated with a combustion cycle. The method causes a very small quantity of exhaust gases to enter the atmosphere by communicating via an exhaust pipe to the imploding cyclonic exhaust chamber in such a manner as to encourage the positively charged vortexing exhaust elements to choose the negatively charged low pressure center of the imploding power turbine rotor as a path of least resistance. Tests completed with a supportive prototype have produced exhaust readings showing that combustion temperature in excess of 2400° F. could be attained. Measured exhaust readings were CO 75 PPM., CO 2 23.5 ppm., SO 2 0.02 ppm., CH x or general hydrocarbons were 0.12 ppm. There were no noticeable odors.
The very high temperatures produced from the plasma combustion are imparted to the imploding exhaust vortex chamber and other elements of the system by utilizing well known principles related to control of electron beams by magnetohydrodynamics technology, wherein electricity is produced from polarized high temperature combustion. When a surplus of randomly polarized particles is released in a combustion plasma cycle, very high temperatures are released that need to be controlled or mitigated so as to prevent excessive heat damage to the system. Within the disclosed system, this is achieved by electrically insulating the exhaust vortex chamber from the rest of the system. This chamber thereby becomes an anode, and the center of the power turbine rotor and fuel ball become a cathode. It is also recognized that a spinning disc, as well as a gas vortex is magnetically polarized.
Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational diagrammatic cross-sectional view of the invention showing its major components and air flow through the apparatus;
FIG. 2 is an elevational fragmentary view of the invention showing structural details of the exhaust chamber and the compressor chamber;
FIG. 3 is a plan diagrammatic view showing a section through one embodiment of the turbine rotor;
FIG. 3a is a cross-section of the turbine rotor seen along the line 3a--3a of FIG. 3;
FIG. 4 is an elevational diagrammatic view of the invention showing compressor and other details;
FIG. 5 is an elevational diagrammatic cross-sectional view of the invention seen along the line 5--5 of FIG. 1 and 6 showing details of the internal construction;
FIG. 6 is an elevational diagrammatic cross-sectional view of the invention showing a section through the compressor rotor, the turbine rotor and the connecting hollow shaft;
FIG. 7 is an elevational plan diagrammatic view seen along the line 7--7 of FIG. 6 showing details of the compressor and turbine rotors;
FIG. 7a is a fragmentary detail section of the turbine rotor according to FIG. 3;
FIG. 8 is an elevational diagrammatic cross-sectional detail view showing details of an embodiment of a compressor and turbine rotor;
FIG. 8a is an elevational diagrammatic cross-sectional fragmentary view showing an ignitor unit;
FIG. 9a is a plan diagrammatic view seen along the line 9a--9a of FIG. 8 showing a compressor rotor according to the axial compression mode;
FIG. 9b is a diagrammatic cross-sectional view seen along the line 9b--9b of FIG. 9a showing an edge view of a compressor rotor according to the axial compression mode;
FIG. 10a is a plan diagrammatic view showing a compressor rotor according to a combined axial and radial compression mode;
FIG. 10b is an elevational diagrammatic view seen along the line 10b--10b of FIG. 10a showing the compressor rotor according to the combined axial and radial compression mode;
FIG. 11 is a cross-section of one version of the ionizing chamber;
FIG. 12 is a diagrammatic cross-sectional view showing a heat exchanger with a transducer;
FIG. 13 is a diagrammatic cross-sectional view showing a heat exchanger composed of multiple coaxial tube sections and an electrolysis electrode;
FIG. 14 is a diagrammatic cross-sectional view showing a heat exchanger with a coiled tubular heating element and an electrolysis electrode;
FIG. 15 is a diagrammatic cross-sectional view showing a heat exchanger with a coiled tubular heating element having its one electrical connection returned to ground potential;
FIG. 16 is an elevational cross-sectional view of the invention in an embodiment having the compressor air outlet injecting air from the air intake side of the air space between the exhaust chamber and the shroud.
FIG. 17 is a diagrammatic cross-sectional view showing an embodiment of the heat exchanger having a porous metal heating element;
FIG. 18 is a diagrammatic cross-sectional view seen along the line 18--18 of FIG. 17 showing the porous metal heating element;
FIG. 19 is a diagrammatic cross-sectional view showing an embodiment of the heat exchanger having a honeycomb metal thin wall heating element; and
FIG. 20 is a diagrammatic cross-sectional view showing the honeycomb metal heating element.
Before explaining the disclosed embodiment of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a diagrammatic cross-section of the gas turbine according to the invention.
Fuel in liquid form enters a liquid fuel intake line 1, passes through a one-way fuel valve 5c and through a heat exchanger 2 having a heating coil 3 or other suitable heat delivery component, which vaporizes the fuel, which enters through a vapor fuel line 4 an ionizing preheating chamber 6. The fuel line 4 is disposed inside an exhaust tube 7 disposed coaxially around the vapor fuel line 4 and rigidly supported in relation thereto. The vapor fuel enters the ionizing preheat chamber 6, and as it traverses the preheat chamber it becomes ionized as will be described in more detail later. The ionized vapor fuel next enters a fuel injector 8 disposed in a mixing chamber 37 in the center of a gas turbine rotor 9.
During operation the turbine rotor is rotating at a high rate of speed. Simultaneously, atmospheric air is transmitted into the mixing chamber 37 of the turbine rotor 9 through an air supply tube in the form of a hollow shaft 5 rigidly attached at its right hand end to the left hand side of the turbine rotor 9 and rotatably supported by a bearing 5d. At the left hand side the hollow shaft 5 is connected to the outlet of an air compressor 18 in a compressor chamber 20 drawing air from air intakes 19 at the right hand end of an exhaust chamber 10 as indicated by arrows D.
The air enters the mixing chamber 37 in the rotor 9 and is mixed with the vapor fuel in the rotor to form an intimately mixed combustible fuel-air mixture. The fuel-air mixture is ducted to a plurality of peripheral combustion chambers 34 (FIG. 3 and 3a) and ignited by an electric ignitor 11 disposed opposite the combustion chambers 34. Each combustion chamber is connected with a tangentially disposed combustion cone 36a which ejects the burning gases at high speed in a swirling clockwise (or counter clockwise) motion, as seen in direction of arrow B, into the exhaust chamber 10. The swirling burning gases ejected from the rotor 9 drive the rotor by the reaction of the ejected gases and continue to the right hand side in a spiral-shaped stream as indicated by arrow B along the inward facing cylindrical surface of the exhaust chamber 10, bounded by a cylindrical, high temperature resistant wall 12 having a right hand inward curved end wall 13, and an opposite left hand planar bearing support wall 15.
As the exhaust gases follow arrow B they form a sustained implosion as they leave the combustion cones 36, and are forced radially inward and reversed in axial direction by the curved end wall 13, to next follow a continued clockwise (or counter-clockwise) inner rotating vortex of a much smaller radius as indicated by the spiral-shaped arrow C. The inner part of the imploding vortex forms an extremely rapidly circularly rotating gas mass due to the small radius and the continued expansion of the hot gases axially moving in direction to the left.
The hot rapidly swirling gases form in this state a hot ionized gas plasma. Due to the rapid rotation, the plasma is stratified by the centrifugal force of the swirling gases so that it is separated with the lighter, electrically charged particles of the plasma drifting inward toward the central structures of the exhaust chamber 10, i.e. the fuel line 4, and ionization chamber 6, which become electrically charged to one polarity, while the heavier particles of the plasma of opposite polarity drift radially outward toward the outer wall 12 of the exhaust chamber 10, which becomes electrically charged to the opposite polarity. A circular insulator 16 between the planar end wall 15 and the exhaust chamber wall 12 and an inner circular insulator 17 between the exhaust tube 7 and shroud 22 provide electrical insulation between the inner structures and the cylindrical wall 12. A further circular electric insulator 17a insulates the vapor fuel line 4 from the heat exchanger 2. Two electric terminals 27 and 28 respectively connected to the fuel line 4 and to the exhaust tube 7 electrically connected to the inner wall 12, are wired by conductors 23, 24 to a high voltage converter 26, which converts the high voltage from terminals 27, 28 to a lower voltage usable to drive e.g. an electric motor 31 coupled by the rotating shaft 32 to both compressor 18 and further to the turbine rotor 9.
Two circular electric insulators 17b and 17c serve to insulate the planar wall 15 from outer shroud 22 to prevent electric conduction between the shroud 22 and wall 15. A circular electric insulator 17d between the compressor 18 and the rotating shaft 32 prevents electric conduction between shaft 32 and compressor 18.
The exhaust chamber 10 is surrounded by the shroud 22 that forms with the exhaust chamber wall 12 a cylindrical air space 21 with intake openings 19 which draw air as indicated by arrows D in a spiral formed path, created by obliquely positioned vanes (not shown) in the air space 21, to intake openings of the compressor 18, rotationally coupled by the hollow shaft 5 to the rotor 9 of the turbine. Due to the spiral shaped path of the air in intake air space 21, heat is effectively transmitted from the exhaust chamber 10 through the wall 12 to preheat the intake air in the air space 21.
On startup of the system, the electric motor 31 is connected via conductors 29 to an independent power source which turns the motor 31, mounted downstream of the gas turbine system, which subsequently turns the compressor 18 and the turbine rotor 9 to bring them up to starting speed. Once full operating speed has been reached the turbine rotor delivers rotational energy via rotating shaft 32 to an external mechanical load via motor shaft 33.
In accordance with one arrangement of the invention, part of the gases in the inner vortex indicated by arrow C reenter the turbine rotor 9 at a center opening 30 at the right hand side of the turbine rotor 9. Another part of burning gases in the inner vortex leaves the exhaust chamber 10 via the exhaust tube 7 in the form of exhaust gases which, due to the high temperature in the exhaust chamber 10, are broken down to the constituents of the air and fuel and consist mainly of water vapor, carbon dioxide, and nitrogen.
FIG. 2 is a cross-section of the fixed structures, including air supply hollow shaft 5, compressor chamber 20, the exhaust chamber 10, the intake air space 21 and other elements as described above. It additionally shows a wheel 36 connected to the air supply hollow shaft 5 by means of a flange 34a bolted to the wheel 36, which serves to protect the planar wall 15 from direct exposure to the hot gases in the exhaust chamber 10. It further shows a protective liner 35 which has an axially extended cross-section of a highly heat resistant material such as graphite, alumina, or other material which protects the exhaust chamber wall 12 against direct exposure to the exhaust gases from the turbine rotor 9. The wheel 36 also serves as a flywheel to even out rotational variations caused by fluctuations in the load on shaft 33.
FIG. 3 is a plan view of the turbine rotor 9, showing a central mixing chamber 37 which serves to receive and mix vaporized fuel from fuel injector 8, compressed and preheated air from the air compressor 18 via hollow shaft 5 and, if applicable, partially combusted fuel-air gases entering via intake opening 30. The mixed fuel-air gases from the mixing chamber 37 flow through channels 38 into a number of peripherally positioned combustion chambers 34, wherein the fuel-air mixture is ignited by means of secondary ignitors 39 (FIG. 3a) which receive electric sparks from the primary ignitor 11 (FIG. 1) in the combustion chamber wall 12 and shroud 22, as described above, as the combustion chambers rotate past the primary ignitor 11, which receive high voltage from a spark generator 41 (FIG. 1) via conductor 42. It follows that one or more primary ignitors 11 may be provided to provide more frequent ignition in the combustion chambers 34. As the fuel-air mixture in the combustion chambers is ignited the ignited mixture rapidly expands and is ejected through expansion cones or chambers 36. The ejected, partially combusted exhaust gases impart a reaction force to the turbine rotor 9 as indicated by arrow E.
It follows that the turbine rotor 9 can be constructed in different ways that would be obvious to a person of ordinary skills in the construction of high-temperature machine elements. Details of one construction mode is shown in FIG. 3a, which shows the rotor 9 constructed of a center core 9a as shown in FIG. 3a, and enclosed between two flanges 41 of high temperature alloy steel or the like. In another mode of construction seen in FIG. 8 the rotor 9 is made of two halfparts 9',9" with the mixing chamber 37, the combustion chambers 34 and the exhaust cones 36 formed into the two halfparts, which are joined by bolts 42 or rivets, welding or the like.
FIG. 4 shows a construction of the invention, which has various features as described below. The compressor rotor is formed as having a plurality of radially extending rotor blades 43 disposed in a circle around the rotating shaft 32, and rotating inside a compressor chamber 20. The intake air is preheated in the intake air space 21, as described above, through controlled air intake openings 44 in a rotatable choke plate 46, which can be turned by a pinion 47 controlled by an electric motor 48, in turn controlled by an exhaust gas analyzer 49, having an exhaust gas sensor 51 in the exhaust tube 7. A fixed choke plate 52 has intake openings that can be aligned with corresponding intake openings in the rotatable choke plate 46 to admit the proper amount of intake air for a stoichiometrically correct fuel-air mixture. The exhaust gas analyzer 49 is conventional and well known from other engine types. The compressor rotor blades 43 compress the intake air into the compressor chamber 20, from where it enters the air supply hollow shaft 5a, which has in the end of the shaft positioned in the compressor chamber 20 a plurality of peripheral air scoops 55 projecting away from the hollow shaft 5a so that air forced into the shaft 5a is given an additional pressure boost for enhanced operation of the system. In the construction according to FIG. 4 the intake air space 21 extends past the planar wall 15 of the exhaust chamber 10, wherein the intake air is preheated as described above and passes through small air vanes (not shown) that impart further rotational movement to the intake air, which is opposite the direction of rotation of the compressor rotor 43 for maximum compressor efficiency. Insulating air vanes 54 are inserted in the forward part of the intake air space 21 to impart rotation to the intake air, as described above, for improved heat transfer from the exhaust chamber 10. Circular electric insulators 16 are inserted between the wall 12 of the exhaust chamber 10 and the planar exhaust chamber end wall 15. The electric charge deposited on the exhaust chamber walls 12 and 13 is taken off at an electrode 60 connected to the converter 26 via conductor 54a, while the other metallic structures are connected to common ground (GRD). Slanted electrically insulating vanes 54, as described above serve to insulate exhaust tube 7 from shroud 22.
The flywheel 36 described under FIG. 2 is also shown in FIG. 4. A reduction gear assembly 56 is shown interposed between the rotating shaft 32 and the electric motor 31, in order to match the rpm of the turbine with the rpm of the motor 31 if necessary.
FIGS. 5, 6 and 7 and 7a show still another construction of the turbine rotor and compressor rotor, wherein the turbine rotor 57 has exhaust cones 59 that extend beyond the perimeter 61 of the turbine rotor 57, as shown in the fragmentary detail FIG. 7a, wherein the mixing chamber 37 is connected via channel 38 with the combustion chamber 59a, wherein the fuel-air mixture is ignited as described under FIG. 3a. The turbine rotor in this construction is more efficient because the expansion exhaust cone or chamber 58 is longer and more tangentially expelling the exhaust gases. The compressor rotor 63 (FIG. 7) seen along the line 7--7 of FIG. 6 is provided with intake scoops 62 (FIG. 7) which help to increase the compressed air pressure delivered to the turbine rotor as described above.
The turbine rotor described above is a radial rotor of the reaction type wherein the rotating moment is derived from the reaction of the ejected gases that exit the rotor in a radial plane. It follows that the rotor could be arranged with the expansion cones ejecting the exhaust gases in direction having one axial component and another component tangential to the perimeter of the rotor. It also follows that more than one turbine rotor could be mounted on a common shaft for generation of increased power, as is known from conventional gas turbines.
FIG. 6 is an edge view of the compressor rotor 63 and the turbine rotor 57, according to FIGS. 5 and 7 respectively.
FIG. 5 is a plan view of turbine rotor 57, seen along the line 5--5 of FIG. 6, which shows the projecting exhaust cones 59, and a plurality of circularly disposed exhaust intake scoops 64 on the side of the turbine rotor 57, which are placed in a circle around the lead-in opening 66 for the fuel injector 8 (FIG. 4). The exhaust gas intake scoops 64 lead into a central mixing chamber 37 (FIG. 7a) corresponding to the mixing chamber 37 of the turbine rotor 9 in FIG. 1. The exhaust gas intake scoops 64 are also seen in the edge view of FIG. 6.
FIG. 7a shows details of the turbine rotor 57 in FIGS. 5 and 7, which include a channel 38 from mixing chamber 37 leading into each combustion chamber 59, in turn connected with an expansion exhaust cone outlet 58.
FIG. 8 is a sectional view showing a compressor rotor 67 mounted on a conical flange forming an intake cone 68 attached to the hollow shaft 5, which are joined by two flanges 69, 71, connected by bolts or rivets 52. The turbine rotor 9 is formed of two halfparts 9', 9" of heat resistant material as described above, and joined by an outer flange plate 41 and an inner flange 74, partially formed as a cone which forms with a central part 37 of the turbine rotor an extended mixing chamber 76, which leads to a plurality of combustion chambers 34 through channels, not seen in the figure, but are similar to the channels 38, seen in FIG. 3. The combustion chambers 34 lead to the tangentially oriented expansion exhaust cones 59, not seen in the figure, but similar to the expansion exhaust cones 36 shown in FIG. 3. The two turbine rotor halfparts 9' and 9" and the flanges 41, 74 are held together by rivets, or bolts 42 or the like. A secondary ignitor 39 is seen connected with each combustion chamber 34 as shown above. The secondary ignitor 39 has, as shown in more detail in FIG. 8a, an insulator 78 and a center electrode 79. The compressor rotor 67 has intake openings 81, as seen in FIG. 9a, having slanted edges 82 that operate to draw air into the intake cone 68.
It follows that the compressor rotor 67 can be formed in several ways. For example, the arms, i.e. spokes 83 (FIG. 9a), between the intake openings 81 can be formed as slanted blades, as known from conventional axial compressors. It also follows that several rotors can be provided in a tandem configuration as known from high pressure axial compressors. Another compressor rotor, seen in FIGS. 10a and 10b has a rotor face plate 84 with radially oriented intake scoops 86, and a cylindrical portion 87 with axially oriented intake scoops 88, again leading into a conical intake chamber 68, wherein the air being compressed forms a vortex as indicated by arrow D in FIG. 8.
An ionizing preheating fuel chamber, seen in FIG. 1 with reference numeral 6, is shown in more detail in FIG. 11, wherein a spherical heating chamber 89 has a vaporized fuel intake line 4 leading into the spherical chamber 89 through an injection orifice 91 that distributes the injected vaporized fuel. Another tubular line 92 surrounds the fuel line 4 and serves to inject a combustion catalyzing agent, through orifices 93 so that a small amount of liquid catalyst is mixed into the fuel vapors in the spherical chamber 89 before the catalyzed mixture is injected into the mixing chamber 37 of the turbine rotor 9 (FIG. 1). The orifices 91, 93a are formed in a body 95 supporting the ends of fuel line 4 and the tubular line 92. A heat exchanger 2 (FIG. 1) is shown in FIG. 12, wherein liquid fuel enters at fuel inlet 95, traverses a heat transfer chamber 93, wherein the fuel is receiving an initial preheating by means of a heating coil 94 which vaporizes the fuel. In order to accelerate the preheating process, a vibrating transducer 96 is advantageously inserted into the heat transfer chamber 93 which sets the liquid fuel in vibrating motion that enhances heat transfer from the heating element 94. The transducer 96 is advantageously of the piezo-electric type. The transducer 96 is connected to a high-frequency generator 97. The heating coil 94 can be an electric heating element connected to an electric power source 98.
Other forms of heat exchange devices are shown in FIGS. 13, 14 and 15. In FIG. 13 concentric metallic tubular heating elements 101a and 101b are connected via terminal 104 and common ground GRD to an electric power source 98 (FIG. 12), and is traversed by liquid fuel entering at inlet 105 and being vaporized by contact with the electrically heated tubular elements 101a and 101b connected by apertures 125 in tubular element 101a. The tubular elements 101a and 101b are separated at one end by means of an electric insulator 102 to prevent short circuit between the elements, as electric power is connected to electrodes 104 and ground GRD. An external tubular element 101c is electrically insulated at its left hand end 131 at insulator 103 supported in a metallic body 135, and is connected via a terminal 106 to a negative pole of a high voltage power supply 132, which causes an electrostatic field to be formed between tubular elements 101c and 101b, which operates to ionize by electrolysis the fuel vapors exiting via apertures 133 in tubular element 101b. Due to electrolysis the fuel vapors are separated into negative and positive ions, including oxygen molecules exiting at exit 136 and hydrogen fuel particles exiting at aperatures 134. The entire mixture of positive and negative ions and molecules is ducted by ducting means 100, shown in phantom lines, into the fuel vapors line 4 from where it proceeds via ionizing chamber 6 to the mixing chamber 37 in the turbine rotor 9 as described above.
Another electrolyzing heat exchanger is shown in FIG. 14, wherein liquid fuel enters at fuel inlet 105, and traverses a coiled tubular heating element 105a to emerge as vapor fuel at coiled tube exit 140, from where it enters an electrolyzing chamber 108 formed by an outer tubular element 137. The outer tubular element 137 is connected to ground GRD via a metallic body 135 supporting the left hand end of tubular element 137. The left hand end of coiled tube element 105a is connected to a terminal 104 connected to one pole of a power source 98, as also shown in FIGS. 12 and 13, having its other pole connected to common ground GRD. A heating current flows from power source 98 through the coiled tubular element 105a, via metallic connection 138, through outer tubular element 137 via metallic body 135 to common ground GRD, which vaporizes the liquid fuel traversing coiled tubular element 105a. The vapor fuel in chamber 108 is exposed to an electrolyzing electric field formed by a high voltage source 132 connected to terminal 106, in turn connected to a central tubular element 139 insulated from the end wall 142 of vapor chamber 108 by an insulator 141. The vapor fuel in chamber 108 is electrolyzed into hydrogen atoms which exit via exit 107 of the central tubular element 139 and oxygen atoms O 2 which exit via apertures 143 and 142 in the tubular element 137. As described above under FIG. 13, the fuel molecules and hydroogen and oxygen atoms are ducted to the vapor fuel line 4 by suitable ducting means.
A non-electrolyzing heat exchanger is shown in FIG. 15, constructed along the lines shown in FIG. 14, except no high voltage field is provided, but only a coiled tubular heating element 105a traversed by fuel entering a liquid fuel inlet 105 and vaporized in heating element 105a to exit as vapor fuel at vapor exit 140. Heating power is provided by electric power source 98, having one pole connected via terminal 104 to one end of the coiled tubular element 105a, and the other pole to common ground GRD. A weeping hole 143 in the outer tubular element 137 allows condensed fuel vapors to escape from the chamber 108, and vapor fuel exits at vapor fuel outlet 107 ducted to vapor fuel line 4.
The tubular element 101c in FIG. 13 and the central tubular element 139 in FIG. 14 acting as electrolyzing electrodes may advantageously be made of thin-walled tubing stock of palladium, platinum, iron cobalt or nickel. These metals and any other metals capable of catalyzing the hydrogenation of the fuel vapors are known to enhance the process of catalyzing the hydrogenation process. Especially palladium is known to be an active catalyzer, and platinum is known to initiate low temperature oxidation. Alternatively the inner surfaces of the heat exchangers which are in contact with fuel vapors may be thinly plated with the aforesaid metals.
The ionizing chamber 6 shown in FIG. 1 is advantageously close to or in the center of the exhaust chamber 10 in the form of a fuel ball.
Further heat exchanger configurations suitable for greater fuel flow-through conditions are shown in FIGS. 17, 18 and 19, 20 wherein FIGS. 17 and 18 show cross-sections of a heat exchanger having a core 111 of porous metal connected between a liquid fuel inlet 112 and a fuel vapor outlet 113, and wherein electric terminals 114 and 116 serve to apply an electric current through the porous core 111, which heats the core to vaporize the fuel. FIG. 18 is a cross-section seen along line 18--18 in FIG. 17, showing terminal 116 in full lines, and terminal 114 in phantom lines.
A heat exchanger of similar construction, but provided with a reticulated honeycomb core 117 instead of the porous core 111 is shown in FIGS. 19 and 20, wherein liquid fuel enters at fuel inlet 118 and is atomized in a fuel nozzle 115, and vaporized fuel exits at fuel vapor exit 119.
FIG. 20 is a cross-section of the core 117 seen along the line 20--20 in FIG. 19.
FIG. 16 shows a version of the invention wherein an externally driven external compressor 121 injects air at the right hand end of air space 21, where it is preheated by contact with the wall 12 of the combustion chamber 10, as also shown in FIG. 1 and next enters the internal compressor intakes 81. The operation of the version according to FIG. 16 is in all other respects as described in connection with FIGS. 4 and 8.
The following section provides some additional clarifying information to the operation of the apparatus above.
The disclosed apparatus serves for combusting fuel by means of a so-called sustained imploding vortex applied to a super-heated, high velocity imploding power plasma turbine. It was discovered that when such a system was properly understood and utilized, it provided a very unique method of maximizing the liberation of energy from all forms of gas or liquid fuels. This invention also utilizes a discovered technology whereby the fuel is super preheated so as to make it chemically and molecularly very active and encases this preheated fuel into an electrically insulated ionizing chamber containing large amounts of free electrons. By actual prototype test results, these electrons are believed to attach themselves to the activated fuel molecules, causing the fuel to become ionized and behave as a gas plasma within the power turbine. The plasma greatly increases the combustion temperature which further increases the potential energy in the plasma. Diesel oil that normally burns at 1200° F. in present systems has a combustion temperature in excess of 2400° F. in a prototype model of the imploding vortex. The flow patterns within this vortex are of extreme importance as they create the sustained implosion within the plasma power turbine and the exhaust chamber. The system is designed to duplicate and to maximize the energy in the imploding vortex.
The imploding vortex is a stratified system of swirling gases, wherein the heavier gas masses become progressively stratified along the outer perimeter of the vortex and the lighter masses become progressively stratified around the central core. The pressure in the vortex is greater near the outer perimeter of the confining chamber and lighter near the central axis of the vortex due to the gravity gradient created by the mass and circular motion of the combusting particles. At the center of the combustion vortex the velocity is very high and the temperature is cool when compared to the condition at its periphery. The disclosed invention utilizes all of the peculiar characteristics of the imploding vortex to its advantage so as to increase thermal efficiency and to reduce polluting emissions normally associated with hydrocarbon fuel combustion.
The swirling electrically charged gas particles in the sustained imploding vortex generate a strong magnetic field in the vortex which further aids in stratifying the gases in the inner and outer vortex, which in turn leads to the separation of oppositely charged gas particles in separate layers. | An energy converting apparatus is provided for converting liquid fuel to electrical and mechanical energy, including an exhaust chamber with external walls and an exhaust port; a gas turbine rotor in the exhaust chamber, with a central air inlet, a fuel inlet, a central exhaust gas inlet and a plurality of tangentially oriented gas ports. Air compressor means are provided for injecting air into the air inlet; fuel delivery means are provided for injecting fuel into the fuel inlet; an inwardly curved end wall in the exhaust chamber serves for receiving and reflecting exhaust gases ejected from the exhaust gas ports and maintaining an imploding vortex, wherein the imploding vortex is reflected back from the curved end wall. The imploding vortex forms electric charges on the external walls and the exhaust gases are ejected from the exhaust gas ports to turn the turbine rotor. Electrical take-off means are provided for taking off the electrical charges as electrical energy. | 5 |
PRIORITY CLAIMS AND RELATED PATENT APPLICATIONS
[0001] This application claims the benefit of priority from U.S. Provisional Application Ser. No. 61/677,674, filed on Jul. 31, 2012, the entire content of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention generally relates to methods and compositions for identifying novel therapeutic agents, and related methods of use thereof. More particularly, the invention relates to novel methods for identifying agents, e.g., bitter tastants, which are useful in treating smooth muscle disorders, pharmaceutical compositions comprising such agents and related methods of use.
BACKGROUND OF THE INVENTION
[0003] Airway obstructive diseases, such as asthma and chronic obstructive pulmonary disease (COPD), have become increasingly prevalent, currently affecting more than 300 million people worldwide. Asthma is an obstructive lung disease where the bronchial tubes (airways) are extra sensitive and, when inflamed, can cause muscles around the airways to tighten making the airways narrower. Asthma is usually triggered by dust, pollen and other allergens, upper respiratory tract infections, etc. COPD, also known as chronic obstructive lung disease, is the occurrence of chronic bronchitis or emphysema, a pair of commonly co-existing diseases of the lungs in which the airways become narrowed, which limits air flow to and from the lungs and causes shortness of breath.
[0004] Dysfunction of airway smooth muscle (ASM) cells in the respiratory tree plays a pivotal role in promoting progression of airway obstructive diseases and in contributing to their symptoms. (Grainge, et al. 2011 New Engl J Med 364:2006-2015; Hershenson, et al. 2008 Annual Rev Pathol: Mechanisms of Disease 3:523-555; Tliba, et al. 2009 Annual Rev Physiol 71:509-535.) With their ability to contract and relax, smooth muscle cells regulate the diameter and length of conducting airways, controlling dead space and resistance to airflow. Excessive contraction of smooth muscle cells can be life-threatening as they can cause the airway to fully close.
[0005] There is an unmet clinical need for new and effective treatments for smooth muscle disorders: (1) their prevalence has almost doubled worldwide in the last few decades, (2) many asthmatics and COPD patients do not respond well to current bronchodilators, and (3) no major breakthrough in bronchodilator development has been achieved since the discovery of specific 132 adrenergic receptor agonists almost fifty years ago.
[0006] Bronchodilators have been used to treat asthmatic attacks and to manage COPD. (Fanta 2009 New Engl J Med 360:1002-1014; Han, et al. 2011 Proc of Am Thoracic Soc 8:356-362.) Existing bronchodilators, however, have undesirable side effects and are not sufficiently effective for severe asthmatics and many COPD patients. Understanding the mechanisms regulating ASM holds the promise of developing more effective and safe bronchodilators.
[0007] Bitter tastants represent a new class of compounds with potential as potent bronchodilators. Bitter taste, the most sensitive of the five basic tastes, is key to animal and human survival since it help them avoid harmful toxins and noxious substances. Deshpande et al. recently found that cultured ASM cells express G-protein coupled bitter taste receptors (TAS2Rs), a class of proteins long thought to be expressed only in the specialized epithelial cells in the taste buds of the tongue. (Deshpande, et al. 2010 Nat Med 16:1299-1304; Chandrashekar, et al. 2000 Cell 100:703-711; Ruiz-Avila, et al. 1995 Nature 376:80-85; Wong, et al. 1996 Nature 381:796-800; Zhang, et al. 2003 Cell 112:293-301.) Bitter tastants with diverse chemical structures have been shown to cause greater ASM relaxation in vitro than β2 adrenergic agonists, the most commonly used bronchodilators to treat asthma and COPD. (Deshpande, et al. 2010 Nat Med 16:1299-1304; Zhang, et al. 2012 Nat Med 18:648-650.) Moreover, these compounds can effectively relieve in vivo asthmatic airway obstruction than 132 adrenergic agonists in a mouse model of asthma, making them highly attractive bronchondilators for asthma and COPD.
[0008] Bitter tastant-induced bronchodilation was unexpected, because these agents appeared to increase intracellular Ca 2+ concentration ([Ca 2+ ] i ) to a level comparable to that produced by potent bronchoconstrictors, which should have led to smooth muscle contraction. (Deshpande, et al. 2010 Nat Med 16:1299-1304; Somlyo, et al. 1994 Nature 372:231-236.) To reconcile this apparent paradox, it was proposed that bitter tastants activate the canonical bitter taste signaling pathway (i.e., TAS2R-gustducin-phospholipase Cβ(PLCβ)-inositol 1,4,5-triphosphate receptor (IP3R)) to increase focal Ca 2+ release from endoplasmic reticulum, which then activate large-conductance Ca 2+ -activated K + (BK) channels thereby hyperpolarizing the membrane. (Deshpande, et al. 2010 Nat Med 16:1299-1304.) It was, however, subsequently demonstrated through patch-clamp recordings that bitter tastants do not activate BK channels but rather inhibit them. (Zhang, et al. 2012 Nat Med 18:648-650.) Moreover, three different BK channel blockers did not affect the bronchodilation induced by bitter tastants.
[0009] The apparent conundrum of putative [Ca 2+ ] I elevation leading to relaxation may be attributed to the fact that Ca 2+ responses to bitter tastants were assessed in cultured human ASM cells, while the contractile responses to them were investigated in freshly dissected ASM tissues. (Deshpande, et al. 2010 Nat Med 16:1299-1304.) It is well known that cultured smooth muscle cell lines alter their phenotype, i.e., losing their ability to contract and relax. (Chamley-Campbell, et al. 1979 Physiol Rev 59:1-61; Hall, et al. 1995 Am J Physiol 268:L1-11.) It is likely their Ca 2+ response is also modified. To understand bitter tastant-induced bronchodilation, it is necessary to study the contraction and the underlying signaling in freshly isolated ASM tissues and cells.
[0010] Thus, in addition to an ongoing need for agents, such as bitter tastants, that are therapeutically effective in treating ASM-related diseases, an urgent need remains for novel methodologies for screening and testing compounds, such as bitter tastants.
SUMMARY OF THE INVENTION
[0011] The invention provides a novel methodology for identifying agents that are useful as therapeutic agents for smooth muscle disorders. The invention also provides pharmaceutical compositions, and methods thereof, useful in preventing, treating or managing smooth muscle disorders.
[0012] In one aspect, the invention generally relates to a method for identifying a candidate compound for treating or preventing a smooth muscle disorder. The method includes: (1) contacting a test compound with a cell of a smooth muscle tissue or organ; and (2) measuring the intracellular Ca 2+ concentration before and after contacting the test compound, whereby a decrease of 30% or greater after contacting the test compound is indicative of the activity of the test compound. In certain preferred embodiments, the method further includes, after contacting a test compound: measuring the cell length before and after contacting with the test compound, wherein an increase of 20% or greater is indicative of the activity of the test compound. In certain preferred embodiments, the test compounds are bitter tastants.
[0013] In another aspect, the invention generally relates to a method for treating or preventing a smooth muscle disorder in a mammal, including human. The method includes administering to a subject in need thereof a therapeutically effective amount of a pharmaceutical composition comprising a compound having the structural formula of (I):
[0000]
[0000] or a pharmaceutically acceptable salt, ester or prodrug thereof, wherein each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is independently selected from hydrogen, OH, alkyl, alkoxy, and halogen; n is an integer from 0 to about 4.
[0014] In yet another aspect, the invention generally relates to a pharmaceutical composition for treating or preventing a smooth muscle disorder in a mammal, including human, comprising a therapeutically effective amount of a pharmaceutical composition comprising a compound having the structural formula of (I):
[0000]
[0000] or a pharmaceutically acceptable salt, ester or prodrug thereof, wherein each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is independently selected from hydrogen, OH, alkyl, alkoxy, and halogen; n is an integer from 0 to about 4.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows exemplary data demonstrating that bitter tastants induce bronchodilation in a concentration-dependent manner. (i) An original recording of chloroquine (chloro)-induced relaxation of bronchi pre-contracted with 100 μM methacholine (Mch). (ii) Concentration-responses of relaxation caused by denatonium (Denat), quinine, chloroquine, and five bile acids (chenodeoxycholic acid, CDCA; ursodeoxycholic acid, UDCA; deoxycholic acid, DCA; cholic acid, CA; and Lithocholic acid, LCA). As a comparison, the concentration-response to a 13 agonist, isoproterenol (ISO), is also included. To construct these curves, cumulative concentrations of bitter tastents and isoproterenol were administrated to the bronchi pre-contracted with 100 μM Mch.
[0016] FIG. 2 shows exemplary data demonstrating that bitter tastants inhibit or potentiate spontaneous tone in mouse internal anal sphincter. (i) An original recording showing bitter tastant (CDCA) reversed totally the spontaneous tone of mouse internal anal sphincter. (ii) A representative recording shows denatonium enhanced the spontaneous tone of mouse internal anal sphincter. The average results on CDCA, UDCA, DCA and chloroquine are shown in (iii). The average results on denatonium are shown in (iv). The spontaneous tone contributes about 70% of the basal tonus that maintains fecal continence in human and animals.
[0017] FIG. 3 shows exemplary data demonstrating that bitter tastants relax human bronchi and pulmonary arteries. (i) Bile acid DCA fully relaxed airways pre-contracted by KCl (which makes potential inside membrane more positive, leading to the opening of voltage-dependent Ca 2+ channels and Ca 2+ influx). (ii) Chloroquine caused a full relaxation while denatonium failed to exert any effect in human pulmonary arteries pre-contracted by KCl. This also indicates that bitter tastants differentially act on different types of smooth muscle, i.e., their action is specific). (iii) Bile acid DCA markedly relaxed human pulmonary artery pre-contracted by KCl. Human specimen were provided by Univ. Mass. Memorial Medical Center.
[0018] FIG. 4 shows exemplary data demonstrating that bitter tastants inhibit mouse urethral contraction induced by contractile agonists. Bitter tastants were pretreated with bitter tastants, and then stimulated with contractile agonists. Contractile agonists alone were used as the control. (A) Chloro (1 mM) blocked 60 mM KCl-induced contraction. (B) CDCA (100 μM) blocked 60 mM KCl-induced contraction. (C) Chloro (1 mM) inhibited alpha1-agonist phenylephrine-induced contraction. (D) 100 μM CDCA inhibited phenylephrine-induced contraction. (E) 100 μM CDCA inhibited 10 μM methacholine-induced contraction.
[0019] FIG. 5 shows exemplary data demonstrating that bitter tastants modestly increase intracellular Ca 2+ concentration ([Ca 2+ ] i ) by activating a canonical TAS2R signaling cascade in mouse ASM. (A) Chloroquine (Chloro) raised [Ca 2 ] i to a level much less than methacholine (Mch). [Ca 2+ ] i was measured with fluo-3 in the form of acetoxymethyl ester, loaded into isolated mouse airway smooth muscle cells, and expressed as ΔF/F 0 (%). (B) 1 mM chloro did not contract airways (using tension as its proxy) while 100 μM Mch caused a robust contraction. Data are mean±s.e.m (n=6 for chloro, and n=5 for Mch). (C) Pertussis toxin (PTX), gallein, Anti-βγ (MPS-phosducin-like protein C terminus, a Gβγ blocking peptide), U73122 and 2-APB inhibited chloro-induced increase in [Ca 2+ ] i (n=19-24 cells). Isolated mouse airway smooth muscle cells were either pretreated with 1 μg/ml PTX for 6-8 hrs or with 1 μM Anti-βγ for 1-2 hrs or with each of the other compounds listed for 5-10 min. The effects of PTX and Anti-βγ were calculated by normalizing the response of chloro to that from the time matched cells without the pretreatments, and the effects of other three compounds were analyzed by normalizing the response of chloro to its own control without the compound. (D) RT-PCR transcripts after amplification with primers to TAS2R107, TAS2R108, α-gustducin, Gβ3, Gγ13, PLCβ2 and β-actin. RNAs were isolated from mouse tracheas and mainstem bronchi, and reactions without complementary DNA were used as a negative control. (E) Cellular distribution of TAS2R107 in three focus planes (bottom, middle, and top) of an isolated mouse airway smooth muscle cell. The TAS2R107 immunostaining intensity after 3D deconvolution (see Methods) was pseudocolored with the color map on the right. This makes positive (but dim) pixels more easily distinguished from background. Eight cells showed a similar subcellular distribution pattern.
[0020] FIG. 6 shows exemplary data demonstrating that bitter tastants reverse Mch-induced increase in [Ca 2 ] i and cell shortening in mouse ASM. (A) Time course of the effect of chloro (1 mM) on a 100 μM Mch-induced increase in [Ca 2+ ] i (represented as ΔF/F 0 integrated over the entire cell) and cell shortening. Images show the changes in [Ca 2+ ] i displayed as fluorescence intensity (rather than ΔF/F 0 to aid visualization). Cell lengths are indicated by red lines. Images were taken at the time indicated on the time course of [Ca 2+ ] i (upper). (B) Relationships between [Ca 2+ ] i (left axis, blue bars) and cell length (right axis, red bars) in response to Mch and Chloro. The letters correspond to the time shown in the upper panel in A (n=23 cells, means±s.e.m; *P <0.05, **P<0.01 using two-tailed Student's t-test). ΔF/F 0 is zero by definition at a, so no blue bar is present at a.
[0021] FIG. 7 shows exemplary data demonstrating that suppression of [Ca 2+ ] i by inhibiting L-type VDCCs is necessary for bitter tastant-induced bronchodilation of Mch precontracted mouse airways. (A) Clamping [Ca 2+ ]; prevented bitter tastants from causing bronchodilation. Mouse airway strips were permeabilized with α-toxin as described previously (Kitazawa, et al. 1989 J Biol Chem 264:5339-5342), and extracellular [Ca 2+ ] i was set at 1 nM and then switched to 3 μM as indicated in the trace. Seven individual experiments (2 for denatonium, 2 quinine, and 3 chloro all at 1 mM) show responses similar to that shown on the left, so the results were pooled and displayed on the right. Each strip's normalized tension is its tension at the experiment's end divided by its tension just prior to application of bitter tastant, times 100. (B) Left panel: L-type VDCC blocker diltiazem dose-dependently reversed Mch-induced contraction (using tension as a proxy measure) (n=6). Right panel: results for n=6 strips. % relaxation=tension decrease due to diltiazem divided by tension increase due to Mch, times 100. The tension decrease at each concentration of diltiazem is measured once the tension stabilizes. The tension decrease at each increased concentration is always measured relative to the peak tension (i.e., it is total decrease, not the incremental decrease due to the additional diltiazem which was added). (C) FPL 64176 (FPL), a L-type VDCC agonist, prevented chloro from reversing the [Ca 2+ ] i rise induced by Mch. Left panel: a typical time course; ΔF/F 0 for each curve is scaled to have a value of 100 at the peak before chloro is added. Right panel: average results of 16 cells. The values are represented as (ΔF/F 0 at the peak after Mch−ΔF/F 0 at 30 sec after chloro)/(ΔF/F 0 at the peak after Mch−ΔF/F 0 at basal)×100 (i.e., the decrease due to chloro divided by the increase due to Mch). **P<0.01, control vs+FPL. (D) FPL dose-dependently reversed chloro-induced bronchodilation (using tension as a proxy measure) in Mch precontracted airways (n=5-7 independent experiments). Data on the right panels are means±s.e.m. % relaxation definition and analysis are the same as in panel B.
[0022] FIG. 8 shows exemplary data demonstrating that KCl only activates L-type VDCCs to increase [Ca 2+ ] i and cause contraction in mouse ASM. (A) KCl failed to generate any global [Ca 2+ ] i increase in the absence of extracellular Ca 2+ . (i) A representative [Ca 2+ ] i response to 60 mM KCl in the presence of extracellular Ca 2+ . (ii, iii, iv), three examples showing that the same concentration of KCl did not increase Ca 2+ in the zero Ca 2+ medium. This failure was not due to the depletion of intracellular Ca 2+ stores because 10 μM Mch still induced Ca 2+ release either as a single peak or as an oscillation. 8 cells gave rise to similar responses. ΔF/F 0 is the average over the entire cell. (B) KCl (60 mM) caused virtually no increase in tension in the absence of extracellular Ca 2+ . The airways were placed in the Ca 2+ free solution for 15 min before the measurement commenced. Left panel shows a pair of representative recordings and right panel the average results. **, P<0.01, Student's paired t-test, n=6 independent experiments. (C) KCl (60 mM)-induced increase in [Ca 2+ ] i was blocked by prior application of L-type VDCC blocker diltiazem (100 μM). **, P<0.01, Student's paired t-test, n=9 for each conditions. (D) Diltiazem relaxed KCl-induced contraction of mouse airways. Data are means±s.e.m. (n=6 independent experiments), and % relaxation definition and analysis are the same as in FIG. 7B .
[0023] FIG. 9 shows exemplary data demonstrating that bitter tastants block L-type VDCCs. (A) Chloro, denatonium and diltiazem relaxed KCl-induced contraction of mouse airways. Left panel shows representative force recordings in response to KCl followed by chloro and denatonium, and the right the mean values of the relaxation of KCl-induced contraction by chloro, denatonium and diltialzem (n=6-9 independent experiments). (B) Relationship between [Ca 2+ ] i and cell length in response to KCl and chloro. Left panel shows the time course of concomitant changes in [Ca 2+ ] i and cell length and the right the means±s.e.m (n=15 cells) at four time points marked on the left. (C) FPL dose-dependently inhibited chloro-induced bronchodilation of KCl precontracted airways. Left panel shows two representative recordings, and the right panel the means±s.e.m (n=5-7 independent experiments). Given the non-monotonic nature of the relaxation (left), both the greatest reduction in force after chloro (i.e., Maximum) and the force reduction 5 min after chloro were measured and divided by the peak force-resting force before application of chloro. (D) FPL 64176 (FPL) inhibited chloro-induced suppression of the rise in [Ca 2+ ] i produced by KCl. Left panel shows original recordings of Ca 2+ responses and the right panel the means±s.e.m (n=28 without FPL, n=16 with FPL). The values represent as (ΔF/F 0 at the peak after KCl−ΔF/F 0 at 30 sec after chloro)/(ΔF/F 0 at the peak after KCl−ΔF/F 0 at basal)×100. (E) Chloro blocked L-type VDCC currents. Left panel displays patch clamp recordings of L-type Ca 2+ currents in response to a voltage pulse from −70 mV to 0 mV in the control and in the presence of 1 mM Chloro, and the right panel the effect of chloro on the current-voltage (I-V) relationship of the Ca 2+ current (n=5). Ba 2+ was used as a charge carrier, and the peak current was used to construct the I-V relationship. The high voltage threshold for activation seen in the I-V relationship, and its sensitivity to FPL and nifedipine indicate these Ca 2+ currents resulted from the opening of L-type VDCCs. *P<0.05; **P<0.01. (Zhuge, et al. 2010 J Biol Chem 285:2203-2210.)
[0024] FIG. 10 shows exemplary data demonstrating that bitter tastants inhibit L-type VDCCs via a Gβγ dependent process. (A) Representative recordings of changes in [Ca 2+ ] in response to KCl followed by chloro (I mM) with and without pretreatment with PTX (1 μg/ml), gallein (1 μM), anti-βγ blocking peptide, U73122 (3 μM) and 2-APB (50 μM). The application protocols for these compounds were the same as in the experiments in FIG. 5C . All data were scaled to have a maximum of 100 and aligned at the time point when KCl was administrated. (B) Effects of compounds listed in A on chloro-induced suppression of KCl-induced increase in [Ca 2+ ] i . The values were calculated the same as in FIG. 8D . Compared to the control (i.e., chloro alone after KCl, FIG. 8D ), P<0.0001 for PTX, gallein, and anti-βγ; and P>0.05 for U73122 and 2-ABP. Data are shown as means±s.e.m (n=12-38 cells). (C) A model for TAS2R signaling and bitter tastant-induced bronchodilation.
[0025] FIG. 11 shows exemplary data demonstrating that bitter tastant chloroquine dose-dependently increased [Ca 2+ ] i in resting single cells (A) without a significant effect on the contractility (B) of relaxed mouse airways. Results are mean±s.e.m, (n=5-30 cells in A and 7 airways in B). Dose response in A was generated based on the responses to single dose administration, while that in B was based on accumulative administration. Mch produced a much larger response.
[0026] FIG. 12 shows exemplary characteristics of [Ca 2+ ] i and contractile responses to bitter tastants and diltiazem in human airway smooth muscle. (A) Bitter tastants reversed the [Ca 2+ ] i rise and cell shortening induced by Mch. Measurements were taken at the steady state levels in response to Mch and chloroquine. The cell length before stimulation was considered as 100%. *, P<0.05 paired student's t-test; ***. P<0.001; n=6-12. (B) L-type VDCC blocker diltiazem dose-dependently reversed 10 μM Mch-induced contraction (n=5 independent experiments). % relaxation=tension decrease due to chloroquine or diltiazem divided by tension increase due to KCl or Mch, times 100. The tension decrease at each concentration of diltiazem is measured once the tension stabilizes. The tension decrease at each increased concentration is always measured relative to the peak tension (i.e., it is total decrease, not the incremental decrease due to the additional diltiazem which was added). (C) Chloroquine and diltiazem relaxed human intrapulmonary bronchi precontracted by 60 mM KCl (n=3-5 independent experiments). Bar charts are means±s.e.m.
[0027] FIG. 13 shows exemplary data demonstrating that Ca 2+ influx plays a major role in producing and maintaining a Mch-induced increase in [Ca 2+ ] i and contraction in mouse ASM. (A) In Ca 2+ free medium (n=10 airways), the tension generated by Mch was less than 20% of that in the presence of extracellular Ca 2+ . ***, P<0.001, Student's paired t-test, n=9 airways. (B) Mch increased [Ca 2+ ] i less in Ca 2+ free medium (n=12 cells) than in the presence of extracellular Ca 2+ (n=9 cells). In the absence of extracellular Ca 2+ , Mch (10 μM) produced different patterns of changes in [Ca 2+ ] i , so the area under each curve was calculated for one minute of Mch stimulation and compared between the two conditions (right panel). ***, P<0.001 with Ca 2+ vs without Ca 2+ , Student's unpaired t-test, n=11. (C) Ca 2+ stores remained functional in the absence of extracellular Ca 2+ . The cells were placed in the absence of extracellular Ca 2+ for 15 min, and then stimulated with two Mch pulses 15 min apart. The chart on the right indicates that two Mch administrations produced comparable Ca 2+ response, i.e., Ca 2+ stores are intact under experimental conditions in the present study. N.S, P>0.05 for the response in the first pulse of Mch vs that in the second pulse, Student's paired t-test, n=10. ΔF/F 0 for B and C are the average over the entire cell.
[0028] FIG. 14 shows exemplary data demonstrating that bitter tastants reverse contractile agonist-induced increase in [Ca 2+ ] i in isolated smooth muscle cells from mouse internal anal sphincter. (A) CDCA (100 μM) reversibly inhibited the increase in [Ca 2+ ] i induced by 60 mM KCl. (B) Chloroquine (1 mM) fully reversed the increase in [Ca 2+ ] i induced by 60 mM KCl. (C) Denatonium (1 mM) did not affect the [Ca 2+ ] i response to 60 mM KCl.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The present invention provides novel methodologies for screening and testing compounds, such as bitter tastants. The unique approach disclosed herein is based on a better understanding of the underlining mechanisms regulating ASM. The invention also provides pharmaceutical compositions and methods of use of certain bitter tastants that are therapeutically effective in treating ASM-related diseases.
[0030] Smooth muscles express bitter taste receptors, the activation of which induces profound changes in the contractility of smooth muscle. Bitter taste receptors are believed to be targets for treating diseases or disorders in smooth muscle. Bitter compounds represent a good starting point for developing therapeutics that relax airway smooth muscle more effective than β 2 agonists, the commonly used bronchidilators for airway obstructive diseases. Some bitter compounds may be capable of relaxing bronchoconstrictor pre-contracted airways that are resistant to β 2 agonist treatment. A unique and effective screening methodology has been developed and disclosed herein that is promised to change the paradigm of research and development on smooth muscle disorders.
[0031] As disclosed first herein, bitter tastants activate the canonical bitter taste signaling cascade, slightly increasing global the intracellular Ca 2+ concentration ([Ca 2+ ] i ) in resting cells, but not to a level sufficient to cause contraction. However, bitter tastants reverse the increase in [Ca 2+ ] i evoked by bronchoconstrictors, leading to bronchodilation. This reversal is mediated by the suppression of L-type voltage-dependent Ca 2+ channels (VDCCs) in a gustducin βγ subunit-dependent, yet PLCβ- and IP3R-independent manner. Hence, it is believed that TAS2R activation in ASM stimulates two opposing Ca 2+ signaling pathways, both mediated by Gβγ subunits, which increases [Ca 2+ ] i at rest but blocks activated L-type VDCCs reversing the contraction they cause. Therefore, bitter tastants can generate different and opposing Ca 2+ signals depending upon the cellular environment.
[0032] The present invention revealed two major differences in Ca 2+ signaling compared to a prior study by Deshpande et al. (Deshpande, et al. 2010 Nat Med 16:1299-1304.) First, Desphande et al. reported that bitter tastant increased [Ca 2+ ] i to a level comparable to bronchoconstictors. In freshly isolated ASM, we found that bitter tastants only modestly increased [Ca 2+ ] i to a level much lower than that produced by bronchconstrictors. Second, Deshpande et al. reported that bitter tastants generate local Ca 2+ events. In freshly isolated ASM, in contrast, we found that bitter tastants did not increase local Ca 2+ releases such as Ca 2+ puffs and Ca 2+ sparks. A reason for these discrepancies may be because Despande et al.'s studies were conducted in cultured ASM cell lines, as oppose to freshly isolated ASM, which display a different phenotype by altering the expression of receptors, ion channels and contractile proteins. (Chamley-Campbell, et al. 1979 Physiol Rev 59:1-61; Hall, et al. 1995 Am J Physiol 268:L1-11.) Additionally, we found that bitter tastants do not activate BK channels. Thus, the evidence establish that bitter tastant-induced bronchodilation is highly unlikely to result from the generation of local Ca 2+ events, which in turn activate BK channel and hyperpolarize the membrane as proposed previously. (Deshpande, et al. 2010 Nat Med 16:1299-1304.)
[0033] By simultaneously measuring [Ca 2+ ] i and cell shortening, we found that bitter tastant's ability to reverse the increase in [Ca 2+ ] i caused by bronconstrictors is the underlying signal producing the bronchodilation. The conclusion that [Ca 2+ ] i is the critical signal governing ASM contractility was supported by at least three lines of evidence. First, in the presence of bronchoconstrictors, bitter tastants lowered [Ca 2+ ] i while at the same time relaxing the precontracted cells. This response was found to be reversible. Second, clamping intracellular [Ca 2+ ] i to levels produced by the bronchoconstrictors (low μM) prevented bitter tastants from relaxing airways. Third, enhancing and blocking Ca 2+ influx via L-type Ca 2+ channels oppositely regulated the relaxation mediated by bitter tastants.
[0034] Gustducin Gβγ inhibits L-type VDCCs to cause bronchodilation, highlighting the importance of these channels in mediating bronchoconstriction and their potential as a target for bronchodilators. Indeed, L-type VDCCs are expressed in ASM cells and their activation causes these cells to fully contract. (Du, et al. 2006 J Biol Chem 281:30143-30151; Kotlikoff 1988 Am J Physiol 254:C793-801; Liu, et al. 2006 Am J Physiol Lung Cell Mol Physiol 291:L281-288; Zhuge, et al. 2010 J Biol Chem. 285:2203-2210.) Activation of these channels is a key mechanism underlying bronchoconstrictor-induced contraction. (Gosens, et al. 2006 Respiratory Res 7:73; Hirota, et al. 2003 British J Anaesthesia 90:671-675; Kajita, et al. 1993 Am J Physiol 264:L496-503; Liu, et al. 2006 Am J Physiol Lung Cell Mol Physiol 291:L281-288.) Moreover, antagonists of L-type VDCCs are effective in relieving airway spasm in animal models of asthma and in at least a subset of asthmatic patients. (Ahmed, et al. 1988 J Allergy & Clinical Immunol 81:133-144; Barnes, et al. 1981 Thorax. 36:726-730; Harman, et al. 1987 Am Rev Respir Dis 136:1179-1182; Patel, et al. 1985 Eur J Respir Dis. 67:269-271.) Although L-type VDCCs in smooth muscle can be modulated by a variety of means including phosphorylation and Ca 2+ , this is the first demonstration that a Gβγ can inhibit L-type VDCCs in smooth muscle. (Gui, et al. 2006 J Biol Chem 281:14015-14025; Le Blanc, et al. 2004 Circulation Res 95:300-307; Liao, et al. 2005 Cardiovascular Res 68:197-203; Thakali, et al. 2010 Circulation Res 106:739-747; Zhong, et al. 2001 J Physiol 531:105-115.) Given that Gβγ can directly inhibit K + channels and N type Ca 2+ channels in several cell types (Herlitze, et al. 1996 Nature 380:258-262; Ikeda 1996 Nature 380:255-258; Reuveny, et al. 1994 Nature 370:143-146; Wickman, et al. 1994 Nature 368:255-257), it is likely that Gβγ acts on L-type VDCCs in a similar manner.
[0035] The opposing Ca 2+ signals mediated by Gβγ upon activation of G-protein coupled bitter taste receptors (TAS2Rs) revealed in this study are unique. It is expected that gustducin Gβγ activates PLCβ to generate IP3 and release Ca 2+ from endo/sarcoplasmic reticulum to raise [Ca 2+ ] i in ASM cells. But, unexpectedly, gustducin Gβγ also suppresses Ca 2+ signaling mediated by Mch, which largely activates M3 muscarinic acetylcholine receptor, a Gq family receptor. In general, Gβγ from the G i /G o family (to which TAS2Rs belong) tends to potentiate, rather than, inhibit the Ca 2+ responses caused by the Gq family. (Cheng, et al. 2002 Biochem J 364:33-39; Samways, et al. 2003 Biochem J 375:713-720.) It remains to be determined whether the inhibition of Ca 2+ signaling by TAS2R activation is Gβγ isoform specific. Since Gβγ also mediates the ASM contractions induced by activation of M2 muscarinic acetylcholine receptors and γ-aminobutyric acid-B receptors, our present findings suggested that Gβγ reversal of the rise in [Ca 2+ ] I caused by bronchoconstrictors is isoform specific, and is likely via Gβ3γ13 dimers which are released upon activation of TAS2Rs. (Mizuta, et al. 2011 Am J Respiratory Cell and Mol Biol 45:1232-1238; Nino, et al. 2012 PLoS ONE 7:e32078; Huang, et al. 1999 Nat Neurosci 2:1055-1062.)
[0036] Investigation was directed at how bitter tastants affected both [Ca 2+ ] i and ASM contraction in freshly isolated airway cells and tissue from mouse and human. Fluo-3 was used to assess the effect of bitter tastants on [Ca 2+ ] i . Chloroquine and denatonium, two substances commonly used to study bitter taste signaling, were used as bitter tastants.
[0037] It is worth mentioning that virtually all of the studies of bitter taste signaling in taste buds and extraoral tissues have focused on the responses mediated by bitter tastants alone. (e.g., Chandrashekar, et al. 2000 Cell 100:703-711; Ruiz-Avila, et al. 1995 Nature 376:80-85; Wong, et al. 1996 Nature 381:796-800; Zhang, et al. 2003 Cell 112:293-301; Janssen, et al. 2011 Proc of Nat Academy of Sci 108:2094-2099; Shah, et al. 2009 Science 325:1131-1134; Tizzano, et al. 2010 Proc of Nat Academy of Sci 107:3210-3215.) The opposing Ca 2+ signaling mediated by Gβγ as disclosed herein may operate in these systems when they are stimulated by a combination of bitter tastants and other activators.
[0038] Bitter tastants induce a stronger bronchodilation in both in vitro and in vivo asthmatic mouse models than do β2 agonists, the most commonly used bronchodilators for treating asthma and COPD. Therefore, these compounds are promising candidates to be developed as a new class of bronchodilators. The findings in the present study provide the cellular and molecular rationale for this line of inquiry. Searching for these bitter tastants is of clinical significance because the current bronchodilators are insufficient for treating severe asthma and many COPD patients.
[0039] TAS2Rs had long been thought to function only in specialized epithelial cells in the taste buds of the tongue. However, studies in recent years have demonstrated that activation of TAS2Rs can generate different biological responses in a variety of extraoral tissues. Bitter tastants were found to cause airway smooth muscle relaxation in vitro in normal mice and human lung specimens, and in vivo in asthmatic mice. This relaxation is greater than that produced by β2 adrenergic agonists, the most commonly used bronchodilators for symptomatic relief in asthma and chronic obstructive pulmonary disease.
[0040] To uncover the underlining mechanism, freshly isolated airway tissue and airway smooth muscle cells from mice and humans have been studied using a combination of Ca 2+ imaging, patch-clamp recording, single cell shortening/tissue contraction assay, and pharmacology. The results showed that activation of TAS2Rs in airway smooth muscle releases the G-protein gustducin βγ. Surprisingly, gustducin βγ, on the one hand, mediates an modest elevation in intracellular Ca 2+ concentration ([Ca 2+ ] i ) in resting cells and, on the other hand, reverses the rise in [Ca 2+ ] i seen in cells treated with bronchoconstrictors (e.g. Gq-coupled receptor agonists), meant to simulate asthma, by suppressing L-type voltage-dependent Ca 2+ channels, thereby producing relaxation.
[0041] Disclosed first herein is that Gβγ mediates opposing Ca 2+ signaling mechanisms, which uncovers a new form of signaling that integrates two major cellular signaling systems (i.e., G-protein coupled receptor and Ca 2+ ) since Gβγ from the G i /G o family usually potentiates, rather than, inhibits the responses by the Gq family. This mechanism likely operates in many types of smooth muscle—a tissue essential for virtually all the internal hollow organs in animals and human, and involved in an array of diseases or disorders such as hypertension and overactive bladder.
[0042] The present invention provides (1) a cellular and molecular basis of a new form of bronchodilation, bitter tastant-induced bronchodialtion, and (2) a molecular explanation for a new class of bronchodilators potentially better than β2 adrenergic agonists. More importantly from a drug development perspective, the invention reveals a Ca 2+ effect that is large enough to be well suited for screening and identifying potent bronchodilators from among the many thousands of available bitter tastants. A critical step in identifying highly potent bitter tastants is developing reliable and highly effective screening methodologies. The better understanding of Ca 2+ dynamics in response to bitter tastants enables a methodology that is promised to accelerate screening and identification of potent bronchodilators from a new class of compounds. Measurements of [Ca 2+ ] i (and optionally in conjunction with measurement of cell shortening) as disclosed herein provide a robust and quantitative approach that represents a powerful new paradigm for identifying bronchodilators from among the many bitter tastants available. Furthermore, the invention provides promising candidates for treating asthma and COPD.
[0043] Thus, in one aspect, the invention generally relates to a method for identifying a candidate compound for treating or preventing a smooth muscle disorder. The method includes: (1) contacting a test compound with a cell of a smooth muscle tissue or organ; and (2) measuring the intracellular Ca 2+ concentration before and after contacting the test compound, whereby a decrease of 30% or greater after contacting the test compound is indicative of the activity of the test compound.
[0044] In certain preferred embodiments, the intracellular Ca 2+ concentration decreased 40% or greater after contacting the test compound is indicative of the activity of the test compound. In certain preferred embodiments, the intracellular Ca 2+ concentration decreased 50% or greater after contacting the test compound is indicative of the activity of the test compound. In certain preferred embodiments, the intracellular Ca 2+ concentration decreased 60% or greater after contacting the test compound is indicative of the activity of the test compound. In certain preferred embodiments, the intracellular Ca 2+ concentration decreased 70% or greater after contacting the test compound is indicative of the activity of the test compound. In certain preferred embodiments, the intracellular Ca 2+ concentration decreased 80% or greater after contacting the test compound is indicative of the activity of the test compound. In certain preferred embodiments, the intracellular Ca 2+ concentration decreased 90% or greater after contacting the test compound is indicative of the activity of the test compound.
[0045] In certain preferred embodiments, the method further includes, after contacting a test compound: measuring the cell length before and after contacting with the test compound, wherein an increase of 20% or greater is indicative of the activity of the test compound. In certain preferred embodiments, the method further includes, after contacting a test compound: measuring the cell length before and after contacting with the test compound, wherein an increase of 25% or greater is indicative of the activity of the test compound. In certain preferred embodiments, the method further includes, after contacting a test compound: measuring the cell length before and after contacting with the test compound, wherein an increase of 30% or greater is indicative of the activity of the test compound. In certain preferred embodiments, the method further includes, after contacting a test compound: measuring the cell length before and after contacting with the test compound, wherein an increase of 35% or greater is indicative of the activity of the test compound. In certain preferred embodiments, the method further includes, after contacting a test compound: measuring the cell length before and after contacting with the test compound, wherein an increase of 40% or greater is indicative of the activity of the test compound.
[0046] In certain preferred embodiments, the test compounds are selected from bitter tastants.
[0047] In certain preferred embodiments, the smooth muscle tissue or organ is part of the respiratory tract. In certain preferred embodiments, the smooth muscle tissue or organ is part of a blood vessel. In certain preferred embodiments, the smooth muscle tissue or organ is part of the gastrointestinal tract. In certain preferred embodiments, the smooth muscle tissue or organ is part of the urinary tract. In certain preferred embodiments, the smooth muscle tissue or organ is part of internal anal sphincter. In certain preferred embodiments, the smooth muscle tissue or organ is part of pulmonary artery.
[0048] The invention is also directed at compounds identified, via the disclosed methods, to have activity in treating or preventing a smooth muscle disorder.
[0049] In another aspect, the invention generally relates to a method for treating or preventing a smooth muscle disorder in a mammal, including human. The method includes administering to a subject in need thereof a therapeutically effective amount of a pharmaceutical composition comprising a compound having the structural formula of (I):
[0000]
[0000] or a pharmaceutically acceptable salt, ester or prodrug thereof, wherein each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is independently selected from hydrogen, OH, alkyl, alkoxy, and halogen; n is an integer from 0 to about 4 (e.g., 0, 1, 2, 3, 4).
[0050] In yet another aspect, the invention generally relates to a pharmaceutical composition for treating or preventing a smooth muscle disorder in a mammal, including human, comprising a therapeutically effective amount of a pharmaceutical composition comprising a compound having the structural formula of (I):
[0000]
[0000] or a pharmaceutically acceptable salt, ester or prodrug thereof, wherein each of R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is independently selected from hydrogen, OH, alkyl, alkoxy, and halogen; n is an integer from 0 to about 4 (e.g., 0, 1, 2, 3, 4).
[0051] In certain preferred embodiments, the compound has the structural formula:
[0000]
[0052] In certain preferred embodiments, the smooth muscle disorder is an airway obstructive disease. In certain preferred embodiments, the airway obstructive disease is asthma. In certain preferred embodiments, the airway obstructive disease is chronic obstructive pulmonary disease (COPD). In certain preferred embodiments, the smooth muscle disorder is anal sphincter disorder. In certain preferred embodiments, the smooth muscle disorder is urethral obstruction. In certain preferred embodiments, the smooth muscle disorder is associated with cystic fibrosis. In certain preferred embodiments, the smooth muscle disorder is associated with fecal incontinence and constipation. In certain preferred embodiments, the smooth muscle disorder is associated with pulmonary hypertension.
[0053] In certain preferred embodiments, R 1 is hydrogen. In certain preferred embodiments, R 1 is OH. In certain preferred embodiments, R 2 is hydrogen. In certain preferred embodiments, R 2 is OH.
[0054] In certain preferred embodiments, the compound is:
[0000]
[0055] In certain preferred embodiments, the compound is:
[0000]
[0056] It should be noted that, although the disclosed screening methods are especially suited for bitter compounds, they can be adopted to effectively screen non-bitter compounds. Additionally, bitter compounds may be of a variety of chemical structures and may be naturally occurring or synthetic. Exemplary bitter compounds include those found at: http://en.wikipedia.org/wiki/Category:Bitter_compounds (accessed on Jul. 19, 2012) and derivatives and analogs thereof. For example:
[0057] Aloin
[0058] Alpha acid
[0059] Amarogentin
[0060] Andrographolide
[0061] Bitrex
[0062] Brucine
[0063] Caffeine
[0064] Denatonium
[0065] Eugenin
[0066] Hesperidin
[0067] Humulone
[0068] Isohumulone
[0069] Kaempferol 3-O-rutinoside
[0070] 6-Methoxymellein
[0071] Naringin
[0072] Papaverine
[0073] Phenylthiocarbamide
[0074] Propylthiouracil
[0075] Exemplary pharmaceutical compositions of the invention include: lung aerosol compositions to prevent, treat or manage asthma, chronic obstructive pulmonary disease, cystic fibrosis; topical preparations to prevent, treat or manage fecal incontinence, haemorrhoids and anal fissure; compositions suitable for oral administration to prevent, treat or manage fecal incontinence and constipation; compositions suitable for oral administration or injection to prevent, treat or manage pulmonary hypertension; compositions suitable for oral administration or injection to prevent, treat or manage urethral obstruction.
Examples
Bitter Tastants Modestly Raise Global [Ca 2+ ] i with No Change in Force Generation in Native ASM at Rest
[0076] Ca 2+ response to bitter tastants in resting cells was examined. In contrast to the marked increase in global [Ca 2+ ] i reported in resting cultured human ASM cells (Deshpande, et al. 2010 Nat Med 16:1299-1304), we observed, in resting native ASM from mouse, that chloroquine (0.1 mM) only modestly raised global [Ca 2+ ] i (and to a level much lower than when cells contracted after application of Mch at 0.01 μM-100 μM) ( FIG. 5A and FIG. 11A ). Chloroquine (330 μM) increased fluo-3 fluorescence (ΔF/F 0 ) (i.e., [Ca 2+ ] i ) both in the presence of extracellular Ca 2+ (37.7±8%, n=19) and in its absence (29.3±6%, n=15; P>0.05), indicating that the source for this chloroquine response is from internal Ca 2+ stores.
[0077] To examine whether this modest increase in [Ca 2+ ] i is sufficient to trigger contraction, smooth muscle force formation in mouse airways was measured. As shown in FIG. 5B and FIG. 11B , chloroquine (10 μM-1 mM) did not cause contraction of mouse airways, although there was a tendency to decrease the basal tone of airways. As a comparison, Mch at concentrations between 0.1 μM and 10 μM induced contraction markedly and in a dose-dependent manner ( FIG. 5B and FIG. 11B ).
Bitter Tastants do not Generate Localized Ca 2+ Events
[0078] Mouse ASM cells exhibit spontaneous Ca 2+ sparks resulting from the opening of ryanodine receptors in the sarcoplasmic reticulum (Zhuge, et al. 2010 J Biol Chem 285:2203-2210). To test whether bitter tastants generate local Ca 2+ events as proposed by others (Deshpande, et al. 2010 Nat Med 16:1299-1304), ASM cells were stimulated with chloroquine (10 μM, a concentration around EC50) for 2 mins and measured Ca 2+ sparks. Off 40 chloroquine-stimulated cells, 27 cells generated a global [Ca 2+ ] i increase that precluded an accurate estimate of Ca 2+ sparks. In the remaining 13 cells without a detectable global rise in [Ca 2 ] i , chloroquine inhibited the spark frequency but had no effect on the amplitude (Frequency (Hz): 2.13±0.24 in control and 1.62±0.21 with chloroquine (n=13, P<0.05, paired student's t-test); Amplitude (ΔF/F 0 at the brightest location): 20.6±1.69 in control and 18.1±1.3 with chloroquine (n=13, P>0.05, paired student's t-test)). To test whether spontaneous Ca 2+ sparks mask the effect of bitter tastants on other forms of local Ca 2+ releases, such as Ca 2+ puffs due to the opening of IP3Rs (Smith, et al. 2009 Proceedings the Nat Academy of Sci 106:6404-6409), the Ca 2+ responses to chloroquine in ASM cells pretreated with 100 μM ryanodine was examined. In these cells, prior to chloroquine application, no spontaneous sparks were observed (n=14). Chloroquine (10 μM) increased global [Ca 2+ ] by 12±4% (ΔF/F 0 at its brightest location) in 9 cells, and failed to cause any detectable Ca 2+ increase in 5 cells. There were no detectable local Ca 2+ events produced in any of the 14 cells. These results indicate that chloroquine at 10 μM does not increase local Ca 2+ events (either Ca 2+ puffs or Ca 2+ sparks).
Bitter Tastants Activate the TAS2R Signaling Pathway to Modesty Raise Global [Ca 2+ ] i in Native ASM at Rest
[0079] Next examined was the cause of the modest global [Ca 2+ ] i rise by bitter tastants. Since in taste cells, bitter tastants bind to TAS2R to activate the pertussis toxin (PTX) sensitive G-protein gustducin, which in turn induces a PLCβ2 and IP3 signaling cascade (Hoon, et al. 1995 Biochem J 309 (Pt 2):629-636; Spielman, et al. 1996 Am J Physiol 270:C926-931), it was studied whether bitter tastants activate this TAS2R signaling pathway. In native ASM cells, PTX (1 μg/ml, and 6-8 hr pretreatment), reduced the chloroquine-induced increase in global [Ca 2+ ] i to 21.1±8.6% of the control cells (n=20; FIG. 5C ). Also both gallein (20 μM and 30 min pretreatment), a blocker of the Gβγ dimer of PTX sensitive G proteins, and MPS-phosducin-like protein C terminus, a Gβγ blocking peptide (Anti-βγ; 1 μM, and 1 hr pretreatment) (Morrey, et al. 2008 J Pharmacol and Exp Therap 326:871-878; On, et al. 2002 J Biol Chem 277:20453-20460) reduced the bitter tastant-mediated increase in [Ca 2+ ] i to 19.9±8.5% (n=19; FIG. 5C ) and 18.4±4.8% of the controls, respectively. Finally, U73122 (3 μM), a blocker of PLCβ, and 2-Aminoethoxydiphenyl borate (2-APB) (50 μM), an IP3R antagonist, suppressed the bitter tastant-induced increases in [Ca 2+ ] i to 18.0±5.5% (n=24) and −10.5±7.3% of controls, respectively ( FIG. 5C ). These results indicate that bitter tastants do activate the BT2R signaling transduction pathway (i.e., TAS2R-PTX-sensitive G protein-PLCβ-IP3R) to release Ca 2+ from internal stores. This conclusion is further supported by the finding that mouse ASM express transcripts for TAS2R107, α-gustducin, Gβ3, Gγ13, and PLCβ2 ( FIG. 5D ).
[0080] Bitter Tastant-Induced Bronchodilation is Due to Reversal of the Rise in Global [Ca 2+ ] i Caused by Bronchoconstrictors
[0081] Bitter tastants at μM levels can modestly increase [Ca 2+ ] i in resting cells, but this raises a conundrum as they also can fully relax airways precontracted by bronchoconstrictors. (Deshpande, et al. 2010 Nat Med 16:1299-1304; Zhang, et al. 2012 Nat Med 18:648-650.) In light of the fact that an increase in [Ca 2+ ] i is the primary signal for contraction in all smooth muscle, we explored how bitter tastants affect [Ca 2+ ] i evoked by bronchoconstrictors. To better quantify these effects, we measured ASM Ca 2+ response and cell shortening at the same time. The cells were stimulated with methacholine (Mch), a stable analogue of acetylcholine that is the major neurotransmitter in parasympathetic nerves. As expected, Mch (100 μM) rapidly increased [Ca 2+ ] i as fluo-3 fluorescence increased by 162±26% (ΔF/F 0 ), and concurrently caused cell shortening by 49±8% (n=21; FIG. 6A and FIG. 6B ). Strikingly, chloroquine (1 mM) almost completely reversed this [Ca 2+ ] i increase (i.e., bringing [Ca 2+ ] i down to a level only 15±2% higher than pre-stimulation levels, n=12, P<0.01 Mch vs Mch+ chloroquine). The reversal of the increase in [Ca 2+ ] i was closely associated with relaxation in ASM cells from both mouse (back to 89±7% of the pre-stimulation length; FIG. 6B ) and human (back to 94±5% of the control length, FIG. 12A ). Denatonium (1 mM) generated similar effects on [Ca 2+ ] i and cell shortening in response to Mch in mouse ASM cells (n=9).
[0082] The inverse relationship between changes in [Ca 2+ ] I and the resulting cell length (i.e., lowering [Ca 2+ ] I results in cell lengthening) in response to bitter tastants indicates that bitter tastants reduce [Ca 2+ ] i , leading to bronchodilation. If this is the case, one would expect that bitter tastant-induced bronchodilation could be prevented if [Ca 2+ ] i was clamped to a physiologically high level. To test this possibility, we used staphylococcal α-toxin (16,000 μ/ml) to make the ASM membrane permeable to ions such that the intracellular [Ca 2+ ] i could be controlled at will. A major advantage of using this toxin is that it does not damage the cells; thus signaling processes such as the G-protein-coupled receptor mediated signaling remain intact. (Kitazawa, et al. 1989 J Biol Chem 264:5339-5342.) As shown in FIG. 7A , raising [Ca 2+ ] i to 3 caused a robust increase in tension in mouse airway. More importantly, at this fixed [Ca 2+ ] i level, denatonium, chloroquine and quinine (all at 1 mM) failed to relax ASM in the time frame they would have in Mch contracted airways without α-toxin treatment. Therefore, clamping [Ca 2+ ] i at μM levels can prevent bitter tastant-induced bronchodilation, strongly arguing that reduction of [Ca 2+ ] i by bitter tastants is necessary for their relaxation action. These results further imply that a decrease in Ca 2+ sensitivity is probably not a major mechanism underlying bitter tastant-induced bronchodilation.
Bitter Tastants Inhibit L-Type VDCCs to Decrease [Ca 2+ ] i Evoked by Bronchonconstrictors
[0083] Mch activates both the M3 muscarinic acetylcholine receptor (M3R)-Gq-PLCβ-IP3 pathway and the M2 muscarinic acetylcholine receptor (M2R)-Gi/o pathway to raise [Ca 2+ ] i by releasing Ca 2+ from internal stores and inducing Ca 2+ influx from the extracellular space (Gosens, et al. 2006 Respiratory Research 7:73; Hirota, et al. 2003 British J Anaesthesia 90:671-675; Kajita, et al. 1993 Am J of Physiology 264:L496-503; Liu, et al. 2006 Am J Physiol Lung Cell Mol Physiol 291:L281-288). It has been suggested that Ca 2+ release from the internal stores contributes to the early phase of Mch-induced contraction, and Ca 2+ influx via L-type voltage-dependent Ca 2+ channels (VDCCs) is largely required to sustain elevated [Ca 2+ ] i and for contraction. Indeed, the sustained contraction by Mch in mouse ASM is largely dependent on Ca 2+ influx ( FIG. 13 ). We established that L-type VDCCs are the major contributor to Ca 2+ influx and sustained contraction since diltiazem, an L-type VDCC blocker, reversed Mch-induced airway force generation dose-dependently in mouse and human airways ( FIG. 7B and FIG. 12B ), and reversed the Mch-induced increase in [Ca 2+ ] by 90.2±2.9% in single isolated mouse ASM cells (n=12 cells). Given the prominent role of L-type VDCCs in Mch-induced sustained contraction, and the fact that bronchodilation by bitter tastants acting during the sustained contractile phase (Deshpande, et al. 2010 Nat Med 16:1299-1304; Zhang, et al. 2012 Nat Med 18:648-650) has been demonstrated by us and others, we hypothesized that bitter tastants inhibit L-type VDCCs, leading to relaxation of airways precontracted by Mch. To test this possibility, it was investigated whether the L-type VDCC agonist FPL can prevent the inhibitory effect of bitter tastants on the Mch-induced [Ca 2+ ] i rise and contraction. At the single cell level, 10 μM FPL can prevent chloroquine from reducing the [Ca 2+ ] i increase caused by Mch ( FIG. 7C ). At the tissue level, FPL can prevent chloroquine from relaxing, in a dose-dependent manner, Mch precontracted mouse ASM ( FIG. 7D ). These results suggest that bitter tastants inhibit L-type VDCCs, which in turn leads to a decrease in [Ca 2+ ] i and resulting bronchodilation.
Bitter Tastants Reverse [Ca 2+ ] i Rise and Contraction Evoked by Depolarization Activation of L-Type VDCCs
[0084] To directly examine the inhibitory role of bitter tastants on L-type VDCCs, we studied the effect of bitter tastants on KCl-induced increases in [Ca 2+ ] i and contraction, and on L-type VDCC currents using patch clamp recording. KCl is a desirable bronchoconstrictor for this line of experiments because most likely it does not involve complex signaling processes (as does Mch). To test this, we compared the contraction and [Ca 2+ ] i response to KCl in the presence of extracellular Ca 2+ and in its absence. In Ca 2+ containing medium, KCl (60 mM) induced a prominent increase in [Ca 2+ ] i ( FIG. 8A ) and contraction ( FIG. 8B ). Yet in Ca 2+ free medium, the same KCl failed to cause any increase in [Ca 2+ ] i or a significant contraction ( FIG. 8A and FIG. 8B ). Since L-type VDCCs are the major Ca 2+ channel for Ca 2+ influx upon depolarization in ASM (Kotlikoff 1988 Am J Physiol 254:C793-801), the effect of diltiazem, a L-type channel blocker, on KCl-induced increase in [Ca 2+ ] i and contraction was examined. It was observed that 10 μM diltiazem pretreatment reduced the KCl-induced increase in ΔF/F 0 from 122±19% to 16.8±10% (n=9, FIG. 8C ); it also reversed the KCl-induced contraction by 93.1±4.8% (n=6, FIG. 8D ). Therefore in mouse ASM high KCl increases [Ca 2+ ] i and causes contraction by depolarizing the membrane and activating L-type VDCCs.
[0085] Give the action of KCl as revealed in FIG. 8 , it was expected that bitter tastants would also relax ASM precontracted by KCl if bitter tastant's inhibition of L-type Ca 2+ channels underlies its relaxation of ASM pre-contracted by Mch ( FIG. 7 ). Indeed, it was found that 60 mM KCl caused a robust increase in tension in mouse and human airways, and this increase could be fully reversed by either chloroquine (1 mM) or denatonium (1 mM) ( FIG. 9A and FIG. 12C ). Similar to their effects on Mch-induced responses ( FIG. 6B ), chloroquine reversed the KCl-induced increase in [Ca 2+ ] i and cell shortening ( FIG. 9B , n=7). Moreover, FPL dose-dependently reversed chloroquine-induced relaxation in ASM pre-contracted by KCl (60 mM, FIG. 9C ), and prevented the reduction of [Ca 2+ ] i by chloroquine in cells stimulated by KCl ( FIG. 9D ). Finally, patch clamping recordings directly showed that chloroquine (1 mM) fully inhibited L-type Ca 2+ channel currents within 2 minutes of application ( FIG. 9E ).
Gβγ Activation Mediates Bitter Tastant Suppression of the Rise in [Ca 2+ ] i Evoked by Activation of L-Type VDCCs
[0086] To address the signaling basis underlying bitter tastant inhibition of L-type VDCCs, we studied the impact of perturbing TAS2R signaling on bitter tastant-induced reversal of the [Ca 2+ ] i increase in response to KCl. Pretreatment with PTX at 1 μg/ml for 6-8 hours prevented chloroquine-induced reversal of the KCl-induced increase in [Ca 2+ ] i as did gallein (20 μM) and Anti-βγ, a Gβγ blocking peptide (1 μM) ( FIG. 10 ). However, U73122 and 2-ABP, at the concentrations that block the bitter tastant-induced increase in [Ca 2+ ] i in resting cells ( FIG. 5 ), failed to alter chloroquine's ability to reverse a KCl-induced increase in [Ca 2+ ] i ( FIG. 10 ). These results indicate that activation of Gβγ but not PLCβ and IP3R is required for bitter tastant-induced inhibition L-type VDCCs.
[0087] When administered alone to ASM cells at rest, bitter tastants activate the canonical TAS2R signaling pathway to modestly raise [Ca 2+ ] i ( FIG. 10C ) without affecting the contraction. Yet when applied in the presence of the bronchoconstrictor Mch, they inhibit L-type VDCCs, leading to a reversal of both the evoked [Ca 2+ ] i rise and the contraction ( FIG. 10C ). Remarkably, both types of Ca 2+ signals require Gβγ, while only the increase in resting [Ca 2+ ] i depends on PLCβ2 activation and IP3 generation.
[0000] Bitter Tastants Reverse Contractile Agonist-Induced Increase in [Ca 2+ ] i in Isolated Smooth Muscle Cells from Mouse Internal Anal Sphincter
[0088] As shown in FIG. 14 , bitter tastants reverse contractile agonist-induced increase in [Ca 2+ ] i in isolated smooth muscle cells from mouse internal anal sphincter. FIG. 14A shows that CDCA (100 μM) reversibly inhibited the increase in [Ca 2+ ] i induced by 60 mM KCl. FIG. 14B shows that chloroquine (1 mM) fully reversed the increase in [Ca 2+ ] i induced by 60 mM KCl. Denatonium (1 mM) did not affect the [Ca 2+ ] i response to 60 mM KCl ( FIG. 14C ).
Effects of Bitter Tastants on Smooth Muscle
[0089] Tests showed that bitter compounds including two bile acids (e.g., DCA and CDCA shown below) can fully relax smooth muscle from airways, internal anal sphincter, pulmonary artery, and urethra from mouse, and smooth muscle from airways and pulmonary artery from human ( FIGS. 1-4 ).
[0000]
[0090] Results also showed that some bitter compounds relax airway smooth muscle, yet contract internal anal sphincter smooth muscle ( FIG. 2 ). These compounds may be used to treat smooth muscle disorders due to weak contraction (e.g., hypotension, urinary incontinence, fecal incontinence and constipation).
Method for Screening Compounds and Identifying Smooth Muscle Relaxants
[0091] Based on the molecular mechanisms proposed herein by which bitter tastants relax smooth muscle, a method was developed for screening agents for smooth muscle relaxants. Results showed that bitter tastants reverse bronchoconstrictor-induced increase in intracellular Ca concentration ([Ca 2+ ] i ) is the underlying signal for their relaxation. This phenomon can be demonstrated robustly and quantatively by simulateous measurement of [Ca 2+ ] i and cell length change at single cell level. The screening method disclosed herein is well suited for identifying relaxants from among the many thousands of available bitter tastants.
Materials and Methods
Animal Tissue Handling
[0092] Experimental protocols for animal research were approved by the Institutional Animal Care and Use Committees at the University of Massachusetts Medical School (protocol A-1473 to R.Z).
Isolation of Mouse Airway Smooth Muscle Cells
[0093] C57/BL6 mice from 7 to 12 weeks of age were anesthetized with intraperitoneally injected pentobarbitone (50 mg kg −1 ), and the trachea and mainstem bronchi were quickly removed and placed in a pre-chilled dissociation solution consisting of (in mM): 135 NaCl, 6 KCl, 5 MgCl 2 , 0.1 CaCl 2 , 0.2 EDTA, 10 HEPES, and 10 Glucose (pH 7.3). The tracheas and bronchi were dissected free from the surface of the connective tissue. The tissue was incubated in the dissociation medium containing papain 30 unit/ml, 1 mM DTT, and 0.5 mg/ml BSA, at 35° C. for 30 min, and then transferred to a dissociation medium containing 3 unit/ml collagenase F and 0.5 mg/mL BSA, and incubated at 35° C. for another 15 min to produce isolated ASM cells. Finally, the tissue was agitated with a fire polished wide-bore glass pipette to release the cells.
Mouse Airway Smooth Muscle Contraction Bioassay
[0094] C57/BL6 mice at 7-12 weeks of age were sacrificed and the entire respiratory trees were rapidly removed and immersed in Krebs physiologic solution containing (in mM) 118.07 NaCl, 4.69 KCl, 2.52 CaCl 2 , 1.16 MgSO 4 , 1.01 NaH 2 PO 4 , 25 NaHCO 3 , and 11.10 glucose. Trachea and bronchi were isolated and cut into rings (4 mm in length). The rings were mounted on a wire myograph chamber (Danish Myo Technology, Aarhus, Denmark), and a PowerLab recording device (AD Instruments) was used to record isometric tension. The ring preparations with zero tension were immersed in 5 ml of Krebs physiologic solution, bubbled with 95% 02 and 5% CO2 at 37° C. The basal tones were set at the level of approximately 2 mN. The order and treatment time of agonists and antagonists are indicated in the figure captions.
Lung Tissue
[0095] Human lung tissue was obtained (with informed consent) from patients undergoing surgery (lobectomy) for lung cancer at the Department of Surgery and the Department of Pathology at the Univ. of Massachusetts Memorial Med Ctr (Worcester, Mass.). The tumors were identified as nonsmall cell carcinoma (adenocarcinoma, squamous cell carcinoma). Intrapulmonary airways were dissected out and cleaned free of the connective tissues. These airways were either cut into the rings (4 mM in length) for force measurements the same as for mouse airway tissues, or digested with the same enzymes, dissociation medium and isolation procedure as for single mouse ASM cells. The experimental protocols on human tissues were approved by the Committee for Protection of Human Subjects in Research at the University of Massachusetts Medical School (Protocol 13590 to R.Z).
Measurement of Global [Ca 2+ ] i and Ca 2+ Sparks
[0096] Fluorescence images using fluo-3 as a calcium indicator were obtained using a custom-built wide-field digital imaging system. The camera was interfaced to a custom made inverted microscope, and the cells were imaged using either a 20× Nikon 1.3 NA for global [Ca 2+ ] measurement or a 60× Nikon 1.4 NA oil for Ca 2+ spark measurement. The 488 nm line of an Argon Ion laser provided fluorescence excitation, with a shutter to control exposure duration, and emission of the Ca 2+ indicator was monitored at wavelengths >500 nm. The images were acquired at the speed of either 1 Hz for global [Ca 2+ ] measurement or 50 Hz for Ca 2+ spark measurement. Subsequent image processing and analysis was performed off line using a custom-designed software package, running on a Linux/PC workstation. [Ca 2+ ] i was represented as ΔF/F 0 *100 with F calculated by integrating fluo-3 over entire cells for global [Ca 2+ ], or just the value at the brightest pixel (i.e., epicenter pixel) for Ca 2+ sparks.
Patch-Clamp Recording
[0097] Membrane currents were recorded with an EPC10 HEKA amplifier under perforated whole-cell patch recording configuration. The extracellular solution contained (in mM): NaCl 126, Tetraethylammonium Cl 10, BaCl 2 2.2, MgCl 2 1, Hepes 10, and glucose 5.6; pH adjusted to 7.4 with NaOH. The pipette solution contained (in mM): CsCl 139, MgCl 2 1, Hepes 10, MgATP 3, Na 2 ATP 0.5; pH adjusted to 7.3 with KOH; amphotericin B was freshly made and added to the pipette solution at a final concentration of 200 μg/ml. Whole-cell Ba 2+ currents were evoked by step depolarization with 300 ms duration every 10 s from a holding potential of −70 mV at a 10 mV increment. Currents were leak corrected using a P/4 protocol.
Measurement of Cell Shortening
[0098] Myocytes were placed into a recording chamber superfused with the bath solution for patch clamp experiments at room temperature. Cells loaded with Fluo-3 were imaged using a custom-built wide-field digital imaging system and their lengths were determined using custom software to manually trace down the center of the cell.
[0000] RT-PCR to Detect mRNA
[0099] The connective tissues in trachea and mainstem bronchi were carefully removed and the ASM were then quickly frozen in dry ice. The total RNA of the ASM was isolated with the TRIzol™ (Invitrogen) method following the manufacturer's guidelines; and cDNA was synthesized using extracted RNA with an Omniscript Reverse Transcription Kit (Qiagen). The specific primers, synthesized by Invitrogen, are listed in Table 1. β-actin was used as a positive control and the absence of DNA as a negative control, and the PCR reaction was carried out in a PCR mastercycler.
[0000] Reagents and their Application
[0100] All chemicals, except fluo-3 (Invitrogen Co, San Diego, Calif., USA), gallein (Tocris Bioscience, Bristol, United Kingdom), and Anti-βγ blocking peptide (AnaSpec, Fremont, Calif., USA), were purchased from Sigma-Aldrich Co. (St. Louis, Mo., USA). For single cell studies, agonists and antagonists were applied locally to cells via a picospritzer at a constant pressure, so that the duration of its action and concentration could be controlled easily.
Statistics
[0101] Unless stated otherwise, data are reported as mean±s.e.m and n means numbers of cells or trachea and mainstem bronchi. Statistical analysis of differences was made with Student's paired or unpaired t-test and the significance level was set at p<0.05.
[0000]
TABLE 1
Primers for RT-PCR
Gene
Forward
Reverse
TAS2R107
TTCCAACTCTGTATTTCTCT
TAATTTTTCCGCTGGTGGA
GGC
TAS2R108
CTAATTTTCAACACCCAGTG
CCCAATTATGTGTTCAGGA
α-
TGGTTACAGCAAACAAGAAT
TTCAAAGCAGGCTTGGATT
gustducin
GC
Gβ3
CAGGACAGCAGAAGACAGTG
GTCATCTGAGCCAGTGCAG
Gγ13
CCCAGCCTCACTCCACAGAT
CCTCTTGAAGGCCAGTTGG
PLCβ2
ATGCAGCAGAACATGGCACT
CCAGCTCAGGCATCAAGAT
β-actin
AGGCCAACCGTGAAAAGAT
AGAGCATAGCCCTCGTAGA
[0102] In this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural reference, unless the context clearly dictates otherwise.
[0103] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described. Methods recited herein may be carried out in any order that is logically possible, in addition to a particular order disclosed.
INCORPORATION BY REFERENCE
[0104] References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made in this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material explicitly set forth herein is only incorporated to the extent that no conflict arises between that incorporated material and the present disclosure material. In the event of a conflict, the conflict is to be resolved in favor of the present disclosure as the preferred disclosure.
EQUIVALENTS
[0105] The representative examples are intended to help illustrate the invention, and are not intended to, nor should they be construed to, limit the scope of the invention. Indeed, various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including the examples and the references to the scientific and patent literature included herein. The examples contain important additional information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof. | The invention generally relates to methods and compositions for identifying novel therapeutic agents, and uses thereof. More particularly, the invention relates to novel methods for identifying agents useful in treating smooth muscle disorders. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a shoe, especially a slipper, having a slip-resistant, shape-retaining outsole.
[0003] 2. Description of the Related Art
[0004] A house slipper is typically designed for maximum comfort and is usually constructed of soft cushioned materials. The upper of the slipper is generally made with fabric-backed foam, and the lower of the slipper generally has foam inserts. The foam provides the desired comfort.
[0005] The outsole of many house slippers is usually entirely constituted of a fabric material. Although generally satisfactory, a slipper with an all-fabric outsole quickly loses its shape, thereby detracting from its appearance. Sometimes, a midsole board is inserted between the upper and the lower of the slipper. However, the midsole board is an extra component and renders the slipper less comfortable.
[0006] Other house slippers have outsoles made from rubber or plastic materials. Although generally satisfactory, a slipper with an all-rubber/plastic outsole is “noisier” during walking as compared to an all-fabric outsole and also tends to have less slip resistance.
SUMMARY OF THE INVENTION
Objects of the Invention
[0007] Accordingly, it is a general object of this invention to provide an outsole for a shoe, especially a slipper, that is shape-retaining even after prolonged usage, that is “quiet” in use, that has an increased slip resistance, and that does not require a midsole board.
FEATURES OF THE INVENTION
[0008] In keeping with the above object and others which will become apparent hereafter, one feature of the present invention resides, briefly stated, in a shoe having an upper, a lower attached to the upper, and an outsole attached to the lower, the outsole having an outer layer constituted of a fabric material and a backing layer constituted of a shape-retaining material, the outer and backing layers being integrally connected with each other, for example, by being molded in situ. In accordance with this invention, the outer fabric layer provides the increased slip resistance and the quieter usage, whereas the shape-retaining, molded backing layer provides the increased shape retention.
[0009] The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view on a reduced scale of a slipper having an outsole in accordance with this invention;
[0011] FIG. 2 is an enlarged, sectional view taken on line 2 - 2 of FIG. 1 ;
[0012] FIG. 3 is a perspective view of the slipper of FIG. 1 as seen from below; and
[0013] FIGS. 4, 5 and 6 are exploded sectional views of alternate embodiments in accordance with this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Reference numeral 10 in FIG. 1 generally identifies a shoe, especially a slipper, having an upper 12 , a lower 14 attached to the upper 12 , and an outsole 16 attached to the lower 14 .
[0015] As best seen in FIG. 2 , the upper 12 includes a soft cushioned material, such as a fabric-backed foam 18 at the interior of the shoe for resiliently engaging a wearer's foot, and an exterior cover, such as a high pile fabric 20 , stitched to the fabric-backed foam 18 . The foam 18 and high pile fabric 20 are merely exemplary materials since many other materials can be used to make the upper.
[0016] As also seen in FIG. 2 , the lower 14 includes a base material 22 at the interior of the shoe for engaging the wearer's foot, and a skirt material 24 at the exterior of the shoe. The base and skirt materials are typically constructed of a fabric, and preferably may be made of the same material as the high pile fabric 20 . An upper portion 28 of the skirt material is stitched to a lower portion of the upper, and is also stitched to opposite sides of the base material 22 along a peripheral seam 26 . A lower portion 30 of the skirt material is stitched to the outsole 16 , thereby forming an internal compartment 32 between the outsole 16 and the base material 22 . One or more foam inserts 34 , 36 are inserted into the compartment 32 to provide cushioning for the wearer's foot. Again, the described choice of materials for the lower is merely exemplary, since many other materials can be used to make the lower.
[0017] In accordance with this invention, the outsole 16 includes an outer layer 38 constituted of a thin, flexible, fabric sheet material, for example, a knitted or woven cloth, and a backing layer 40 constituted of a shape-retaining material, for example, a rubber or a plastic material. The fabric layer 38 and the backing layer 40 are integrally connected together, for example, by being molded in situ in a common mold.
[0018] The backing layer preferably has a raised and/or recessed tread pattern, as exemplified by the flower-like decorations 42 and diagonal ribs 44 visible on the underside of the shoe in FIG. 3 . The fabric layer 38 closely conforms to the pattern and, indeed, follows the contour thereof. Other tread patterns, are, of course, contemplated by this invention.
[0019] Also contemplated is the application of graphic markings on the fabric layer 38 . The graphic markings are applied in any known manner, for example, silk screening or printing. Virtually any markings can be employed.
[0020] Alternate shoe constructions are depicted in the remaining drawings. FIG. 4 depicts an outer fabric layer 138 integrally connected to a backing layer 140 . An upper 112 consisting of a flexible fabric is attached to the backing layer 140 by an adhesive as shown, or by stitching. A base material 122 overlies a foam insert. 134 and is attached to the upper 112 , again by using an adhesive or stitching.
[0021] FIG. 5 depicts an outer fabric layer 238 integrally connected to a backing layer 240 . An upper 212 consisting of a flexible fabric is attached to the backing layer 240 not through another fabric as in FIG. 2 , and not by an adhesive as in FIG. 4 , but instead, is inserted into the same mold in which the backing layer 240 and the fabric layer 238 are molded. The upper 212 is injection molded into the backing layer 240 . A base material 222 overlies a foam insert 234 and is attached to the backing layer 240 by using an adhesive or stitching.
[0022] FIG. 6 depicts an outer fabric layer 338 integrally connected to a backing layer 340 . An upper 312 consisting of a flexible fabric is attached to the combination of the backing layer 340 and the fabric layer 338 by stitching 339 . A base material 322 overlies a foam insert 334 and is inserted into a well of the backing layer 340 and is secured therein by using an adhesive or stitching.
[0023] Other variations are possible. In each case, however the outer fabric layer is integrally connected to the backing layer.
[0024] It will be understood that each of the elements described above, or two or more together, also may find a useful application in other types of constructions differing from the types described above.
[0025] While the invention has been illustrated and described as embodied in a shoe with slip-resistant, shape-retaining fabric outsole, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
[0026] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims. | An outsole for a shoe, especially a house slipper, has an outer layer constituted of a fabric material, and a backing layer constituted of a shape-retaining, moldable material. The fabric layer and the backing layer are molded integrally together to provide the outsole with increased slip resistance, quieter usage and increased shape retention. | 0 |
BACKGROUND OF THE INVENTION
This invention relates generally to the field of telecommunications and in particular to a queue management method for a wireless Asynchronous Transfer Mode (ATM) network interface card (NIC).
Asynchronous Transfer Mode (ATM) has long been advocated as an important technology for interconnecting wide area heterogeneous networks. In networks constructed utilizing ATM technologies, transported data is divided into small, fixed length units called cells. These cells are further divided into a header and data portion, with the header portion comprising identification, priority and routing information, and the data portion comprising actual data transported between systems.
An important distinguishing characteristic of ATM and networks constructed therefrom, is that it is an end-to-end technology, meaning that with ATM networks the protocols (ATM) are uniform throughout the entire network. That is to say, the ATM on the desktop is the same as the ATM on the Local Area Network (LAN), is the same as the ATM on the Wide Area Network. Consequently, organizations that employ ATM networks do not need extra equipment (like routers or gateways) to interconnect their networks thereby reducing the cost and complexity of the networks while at the same time improving their flexibility.
Due to these and other inherent advantages, there has been widespread and rapid deployment of ATM networks. This rapid deployment of ATM networks, and the contemporaneous need to provide reliable wireless ubiquitous information access to end users, has accelerated the development of Wireless ATM (WATM) networks. Presently, the development of WATM networks is still research oriented, and efforts to specify a standard for its protocol reference architecture are underway. See, for example, the article by D. Raychaudhury et al, entitled "ATM-Based Transport Architecture for Multiservices Wireless Personal Communication Networks", which appeared in Vol. 12, No. 8 of IEEE JSAC in October 1994, or proceedings. An example of a Wireless ATM network which has been prototyped to ascertain the requirements for future WATM network has been described by D. Raychaudhury et al., in an article entitled "WATMnet: A Prototype Wireless ATM System for Multimedia Personal Communication", ICC '96.
In WATMnet, as well as in other WATM networks, a Network Interface Card (NIC) is used to interface a piece of equipment to the WATM network. As can be readily appreciated by those skilled in the art, the architecture of a NIC plays an important role when accessing a high-performance network such as ATM. Specifically, the NIC can become a network bottleneck if its throughput characteristics are not taken into consideration while designing its architecture. Since the Data Link Control Layer (DLC), the Media Access Control Layer (MAC), and RPhy layers are integrated in a WATM NIC, the WATM NIC's processing requirements are more demanding than that of ATM NICS at equivalent transmission rates. (See, for example, R. Dighe et al., "The Multimedia C&C Platform (MCCP), A Network-Centric Architecture for Multimedia", IEEE ATM Workshop '95, October 1995; and C.A. Johnston, "Architecture and Performance of HIPPI-ATM-SONET Terminal Adapters", IEEE Communications, Vol. 33, No. 4, April 1995.) Thus, the design of a high-throughput WATM NIC software/hardware architecture remains a challenging problem.
Critical for the usefulness of such NIC adapters, is an efficient architecture that can allow network communications to proceed in parallel with other operations on a host without excessively slowing down those operations. Also critical to the efficiency of the entire network is a need that the adapter have minimal latency in reception and transmission of data. At the same time, the adapter must be economical to be suitable for accompanying host equipment.
Therefore, a need exists in the art for apparatus and methods which provide for the efficient and flexible wireless interfacing of computer and other electronic devices to ATM networks.
SUMMARY OF THE INVENTION
According to the invention, a network interface card that provides an interface between a host and a wireless asynchronous transfer mode based communications network, effectively and efficiently offloads and unburdens the host from the formatting, error checking and transmission of data over the wireless network. The network interface card advantageously employs an on-board controller, a local memory, on-board framing and error checking, as well as wireless transmission and receiving.
As a further aspect of the network interface card, data that is to be transmitted or received is advantageous stored within the network interface card according to type, thereby allowing the card to support a number of known, network protocols. As a still further aspect of the network interface card, an entire data link control protocol layer is provided on-board the card, further off loading the host from this low level function. Importantly, and in accordance with the method of the present application, data cells which are transmitted are transmitted in a particular sequence until an error in the data link occurs. Upon such condition, the data link recovery procedure is handled by a control processor on the card while, in parallel, remaining cells are transmitted in a particular sequence. Similarly, data cells which are received from the wireless network are received in a particular sequence until an error in the data link occurs. Upon such condition, the data link recovery procedure for is handled by a control processor on the card while, in parallel, remaining cells are received in a particular sequence.
A further understanding of the nature and advantages of this invention may be realized by reference the remaining portions of the specification and drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
FIG. 1 shows a block diagram of a WATM NIC according to the teachings of the present invention;
FIG. 2 shows a simplified block diagram of the WATM NIC architecture of FIG. 1;
FIG. 3 shows dual-port RAM partitioning according to the present invention;
FIG. 4 shows a Queue Control Region FIFI Data Structure;
FIG. 5 shows FIFO implementation according to the present invention;
FIG. 6 is a block diagram showing WATM AAL Co-Processor architecture according to the present invention;
FIG. 7(a) and 7(b) show examples of representative data structures in the v851 processor;
FIG. 8 depicts dual-port address generation;
FIG. 9 shows the Cell Pool RAM partitioning;
FIG. 10(a) shows Pointer Processor Transmitter RAM Partitioning;
FIG. 10(b) shows the XQueue Region functionality of FIG. 10(a);
FIG. 11 is a flow diagram showing connection setup of a terminal to the v851;
FIG. 12 is a flow diagram showing terminal data transfer to the NIC;
FIG. 13 is a flow diagram showing data transmission from NIC to wireless network;
FIG. 14 is a flow diagram showing DLC acknowledgment to NIC;
FIG. 15(a) shows Pointer Processor Receiver RAM Partitioning;
FIG. 15(b) shows the Queue Region functionality of FIG. 15(a);
FIG. 16 is a flow diagram showing connection setup from wireless network to v851;
FIG. 17 is a flow diagram showing terminal data transfer from NIC to terminal; and
FIG. 18 is a block diagram of the cell pool address generator.
DETAILED DESCRIPTION
A preferred embodiment of the invention will now be described while referring to the figures, several of which may be simultaneously referred to during the course of the following description.
Referring to FIG. 1, a block diagram is shown of a Wireless Network Interface Card (WATMNIC) according to the present invention for communications between a client terminal and a wireless Asynchronous Transfer Mode Network.
With further reference now to FIG. 1, multimedia applications 14, running under any one of a variety of well-known operating systems, interface with a Host Kernel to access networking software such as Transmission Control Protocol/Internet Protocol (TCP/IP), User Datagram Protocol (UDP), or MTP, 16. As is known in the art, TCP/IP is often used and well suited for applications which do not require real time performance. However, in order to support real-time traffic such as CBR or VBR, other protocols such as MTP must be supported at the Mobile as well.
With reference now to FIG. 2, there it shows a block diagram of a Network Interface Card 200 according to the present invention. The functional blocks comprising the Network Interface Card include PCMCIA interface 202, Dual-Port RAM 204, WATM/AAL processor 210, Cell Pool Ram 206, TDMA Framer 208, Pointer Processor 212, RAM 218, ROM 216 and Microcontroller 214 each interconnected via electrical and mechanical interconnect 201.
The PCMCIA Interface 202 is preferably implemented using a commercially available integrated circuit (IC) which supports the PCMCIA version 2.1 standard. Through the PCMCIA interface, Terminal equipment (not shown) accesses a Dual-Port RAM 204, in a PCMCIA Common Memory configuration, to move data in and out of the NIC. Access to the Dual-Port RAM is shared with the Microcontroller 214, i.e., v851 RISC processor, under the control of an arbiter 220, implemented within the PCMCIA block. The arbiter gives higher access priority to the Microcontroller, which also maps its memory space to access the Dual-Port RAM. Through the Dual-Port RAM, Terminal equipment communicates with the network, and also exchanges information with the Microcontroller. Similarly, the Microcontroller can also exchange data with the network. This architecture allows to implement functions such as ATM signaling on board the NIC.
The Dual-Port RAM 204 allows the decoupling of a terminal and network side of the NIC. In this configuration, the NIC throughput performance is improved by allowing the transfer of data from Terminal Equipment, or Microcontroller to the memory to occur while the network side simultaneously stores incoming data.
The Dual-Port RAM is partitioned in different regions as shown in FIG. 3. The Message region 302 allows for the exchange of control messages between the Terminal Equipment and the Microcontroller, and between the Microcontroller and the wireless network. The ABR 308, VBR 306, and CBR 304 regions implement a First In-First Out (FIFO) functionality to buffer the wireless traffic. Two FIFO's are incorporated per traffic class, one in the transmit direction and one in the receive direction. The Queue Control region 310 contains data structures to accomplish the FIFO functionality of the ABR, VBR, CBR, UBR, and Message regions. Those skilled in the art will quickly recognize that there can be many buffers contained within a region.
FIG. 4 shows the Queue Control Region FIFO Data Structure 400. This region consists of data structures required to achieve FIFO functionality of the ABR, VBR, CBR, and Message regions. The Offset parameter 408 indicates the start address of the FIFO in the RAM space. The Length parameter 406 indicates the size of the FIFO being implemented. The Write Pointer 404 stores the distance value from the Offset where data is stored. The Read Pointer 402 is used in combination with the Offset parameter to indicate where data is to be retrieved from.
Whenever the Write and Read pointers are of equal value, the FIFO is empty. If the Write pointer starts catching up with the Read Pointer after a number of writes, the FIFO is considered full if the Write Pointer plus one is equal to the Read Pointer. When a FIFO is full, incoming data is dropped. The values of the Write and Read pointers are always reset to zero when either pointer reaches the value of the Length parameter, effectively creating a circular buffer. FIFO occupancy can be determined by using the Length, Write and Read pointers. If the Write pointer value is greater than the Read Pointer, then the FIFO occupancy is determined by the difference between the Write and Read pointer values. Otherwise, the occupancy is determined by subtracting from the Length, the value of the difference between the Read and Write pointers.
FIFO functionality is implemented in each of the ABR, CBR and VBR regions to store and retrieve data. The ABR region stores Available Bit Rate data, the VBR stores Variable Bit Rate data, and the CBR region stores Constant Bit Rate data. Preferably, two FIFOs are implemented per region, one in the transmit direction and one in the receive direction. For each direction, a FIFO utilzes the structures previously described.
FIG. 5 shows an example of how FIFOs are implemented by partitioning the Dual-Port RAM. In this scheme, different FIFO sizes, based on the traffic class buffering requirements, can be obtained. By having different traffic class buffers, it is possible to implement a scheduling algorithm at the terminal to optimize the movement of time-sensitive data through the PCMCIA interface. Otherwise, it is also possible to implement a single FIFO area for movement of data across the PCMCIA interface to simplify the Terminal software implementation.
The Message region comprises four FIFOs implemented as described above. Two of the FIFOs provide for the storage of messages associated with Terminal to Microcontroller communications, while the other two provide for the transfer of messages between the Microcontroller and the wireless network. For example, before any connection can be established, the Microcontroller will use two of the FIFOs to run ATM signaling software with the WATM network. Once a signaling Virtual Circuit Identifier has been established, the Microcontroller will communicate with the Terminal thereby establishing connections in either the outgoing or incoming direction. When a Terminal requests to establish a connection, it will petition for permission to access the NIC resources through the Terminal to Microcontroller FIFOs.
The WATM Co-processor exhibits a pipeline architecture which allows for the flexible formatting of AAL 1, 3/4 and 5, as well as ATM, and WATM cells. The Co-processor architecture has been designed by identifying generic building blocks required in the implementation of the above named transfer protocols. The WATM AAL Co-processor attaches to a main RISC CPU, in this case the v851, to relieve it from the burden of time-consuming operations by offering fast customized hardware processing. In general, the v851 keeps track of data structures on a per connection basis while data movement and formatting is performed by the Co-processor. In this manner, the v851 operating cycles are saved and can be effectively used to perform other functions.
A block diagram of the Co-processor is shown in FIG. 6. It comprises seven pipeline stages containing generic blocks that can be effectively shared to obtain the formatting of the different AAL, ATM and WATM transport protocols. Preferably, the Co-processor is memory mapped to the v851 to control its operation. Sets of instructions implementing the AAL, ATM, and WATM protocols are stored in the Program RAM 604, where they are accessed and interpreted by the Instruction Controller 602.
The Registers 620 are accessed by the v851 to insert protocol overhead data. The overhead data is stored in firmware structures within the v851. With reference now to FIG. 7, there it shows C-language structures for an ATM header (atmh), AAL3/4 convergence sub-layer (cs34), and segmentation and reassemble sublayer overhead (sar34). In a transmission scenario, the v851 writes the contents of the software structures in the Registers, and it then initiates the Instructions Controller to start the desired protocol formatting program. At such time, the Co-processor handles data movement and data formatting. No further involvement is required by the v851. Thus, the v851 is relieved of time-consuming operations and can be effectively used in other operations. When the Co-processor is finished with its required instructions, the v851 data structures for a given connection can be updated with the values to be used in the next transmission cycle.
During data formatting, and with continued reference to FIG. 6, overhead is multiplexed by MUX1 618 from the Registers with data from the Dual-Port RAM (not shown) to form the desired overhead/data combination. The Co-processor incoming data is then circulated through the ALU stage 616 which performs operations such as adding one to increment Sequence Number (SN) overhead, or to perform comparison when SN are received from the network. Data is then operated on by the Shuffle stage 614, which performs dedicated AAL 1 and AAL 3/4 bit shifting manipulations in one cycle time. Subsequently, within the CRC Machine stage 612, specialized hardware implements CRC-3, CRC-8, CRC-10, and CRC 32 which operates simultaneously on the data continuously. When a CRC has been calculated, it is then inserted through the multiplexer MUX2 610 at a location controlled by the Co-processor program. For Wireless ATM applications the CRC-16 machine 608 allows the generation of CRC overhead and attaches it to the data through the control of the third multiplexer MUX3 606. The output of MUX3 is stored in the Cell Pool RAM (not shown) under the control of the Pointer Processor.
The Pointer Processor (PP) generates memory address locations where data is to be stored or retrieved by the WATM AAL Co-processor, and by the TDMA block of FIG. 2. The PP includes two parts, the first (PP-I) controls the information writing or reading of the Dual-Port RAM, and the second (PP-II) implements queue management of the Cell Pool RAM.
FIG. 8 shows one implementation of the PP-I address generator side 800. Through the v851 interface 802 internal registers are loaded with the values contained within the Queue Control Region. In a store cycle, the Write pointer is used, while in the retrieve cycle the Read pointer is used. These pointers are incremented by one by the `Carry In` signal. The Length value is compared with the adder output to rollover the Read or Write pointers to zero whenever the FIFO length is reached. In this manner, a circular queue functionality is effectively achieved. By adding the Read or Write pointers to the Offset value, the address where data is to be stored or retrieve at the Dual-Port RAM is obtained. After a write or read cycle is finished, the v851 retrieves the new Write or Read pointers and updates the Queue control structure for later use.
The PP-II generates the memory address locations for the Cell Pool RAM. It provides queue management control on a per connection basis, while also providing functionality that is required to support the DLC protocol. The Cell Pool RAM is partitioned as shown in FIG. 9. The WATM Cell Region 902 is partitioned into a number of 56 byte regions, each region having a header 906 and a body 908 and which serve to store WATM cells in the transmit and receive directions. WATM cells can then be linked by managing pointers using the following technique that merge FIFO Queue Management and DLC operation requirements in a single novel architecture.
Advantageously, ATM queue management and DLC is merged in such a manner as to support virtual queues on a per connection basis with the capabilities of WATM cell retransmission and cell reordering.
With reference now to FIG. 10 (a), there it shows the partitioning of RAM memory residing within the Pointer Processor Unit shown in FIG. 2 in the transmit direction. A VCI Region consists of data structures which permit the emulation of FIFO functionalities of the Xpointer 1004 and Xqueue 1006 regions, respectively. The Xpointer Region contains free start address pointers which indicate where WATM cells can be stored in the Cell Pool RAM. These pointers are stored in a FIFO manner using any of a variety of techniques. The XQueue region contains the address pointers of stored cells in the Cell Pool RAM.
FIG. 10(b) shows the structure of the Xpointer and XQueue Regions. The size of the Xpointer Region determines the queue size for a given connection based on its quality of service (QOS) requirements. A number of Address Pointers which guarantee the required QOS is stored in this region. These pointers are referred to as Free pointers, and are initially managed within the v851. Upon a connection setup request by the Terminal, the v851 is responsible for performing the operations shown in the flowchart of FIG. 11. A similar operation is also required to set up the received queue.
When a data transmission is made by the Terminal, the process depicted in the flowchart shown in FIG. 12 is performed thereby moving data through the Dual-Port RAM to the Cell Pool RAM. A Free pointer (FIG. 10(b)) in the Xpointer region is moved to the XQueue region when a cell has been written to the Cell Pool Ram. The X-Queue region implements the standard FIFO implementation. The `xqWritep` is incremented as WATM cells are stored in the Cell Pool RAM, while the `xqReadp` is decremented every time the TDMA Framer (FIG. 2), transmits data to the wireless network. The FIFO occupancy given by the `xqWritep` and `xqReadp` pointers is used by the Supervisory MAC to determine how much data is to be transmitted. FIG. 13 shows the steps required to transmit WATM cells by the TDMA Framer.
A `xqSvrdp` pointer is also part of the XQueue region, and it is used by the DLC to keep track of cell retransmissions. Initially, the `xqSvrdp` and `xqReadp` pointers are at the same location. But, as the Framer reads data, the `xqReadp` pointer advances, and the `xqSvrdp` value stays pointing at the First transmitted cell awaiting transmission acknowledgment. FIG. 14, shows the process required for DLC Acknowledgment to the NIC.
In summary, `xqsvrdp` is advanced every time a cell is acknowledged. If the acknowledgment matches the expected WATM cell, the XQueue region pointer returns to the Xpointer region. Otherwise, the v851 is called upon to perform WATM cell retransmission and to control the Cell Pool pointer. The v851 returns the Cell Pool pointer to the Xpointer region when retransmission has successfully been accomplished, or at retransmission time-out.
FIG. 15(a) shows the Pointer Processor's RAM structure in the receive direction. The VCI Region 1502, previously described, includes data structures which implement the Rpointer 1504 and Rqueue 1506 regions. The Rpointer region contains the Free Pointer to the Cell Pool RAM, and it is setup as shown in FIG. 16. An example of the Rpointer and Rqueue regions is shown in FIG. 15(b). When WATM data cells are received, a Free pointer is taken from the Rpointer region. If no pointers are found the cell is dropped. Otherwise, the pointer is stored in the Rqueue region. The `rqWritep` pointer is incremented when cells are received or whenever cell losses are detected by checking the SN value. When cells are lost, Free pointers to the Rqueue region should be proportional to the amount of lost cells. Also, whenever cells are lost, the `rqSvrdp` is frozen in value indicating the cells that are in correct sequence order. The difference between the `rqSvrdp` and `rqReadp` indicates to the Supervisory Mac (v851) which cells are in sequence order and therefore ready for transfer to the Terminal. Whenever the `rqSvrdp` and `rq Writep` pointers are equal, no out of sequence transmission has occurred. Out of order cell retransmissions are handled by the v851 which adjusts the `rqSvrdp` pointer as appropriate. The flowchart shown in FIG. 17 shows the operation of the receiver.
As can be readily appreciated by those skilled in the art, the implementation of PP-II is more complex than that of the PP-I. But, a similar datapath structure can be used to generate the required address pointers to the Cell Pool RAM. FIG. 18 shows such a possible implementation.
Specifically, a `VCI` value 1834 indicating which queue to access, and a `Transmit/Receive` signal 1836 indicating which direction data is coming from, is provided to the PP-II Controller 1830. The Controller then accesses the respective VCI Region and load the Xpointer and XQueue, or the RPointer and RQueue parameters in the PP-II registers. For instance, in the transmit direction the `xLength` value would be loaded in the Length 1 register 1802, and the `xqLength` in the Length2 register 1804. The `xOffset` and `xqOffset` are loaded in the Offset 1 1820 register and Offset 2 register 1824, respectively. The remaining parameters are then loaded in the Read or Write 1 and 2, and Svrdp registers (1812, 1816 and 1818 respectively). The controller then uses Finite State Machines (FSM) or a microprogram to synchronize and perform the WATM Cell Pool Management and DLC. The Controller also arbitrates through the effect of the arbiter 1850, access to the Cell Pool RAM by either the WATM/AAL Co-processor or the TDMA Framer (signals not shown). The controller also provides the pointer (address) to the Cell Pool Ram.
Preferably, the TDMA Framer should be given priority and the WATM/AALCo-processor functionality should be frozen. If Information is being transferred to the Cell Pool by the WATM/AAL Co-processor, its temporary Xpointer and XQueue register status should be stored in the Pointer Processor RAM, and then stored after the TDMA Framer is finished with its task. Finally, access to the Pointer Processor RAM should be arbitrated by the arbiter since the v851 also requires to set up and collect information about queue status on this memory component.
The function of the TDMA Framer is to transmit and receive WATM cells by structuring information in a TDMA/TDD format. It is preferably designed in a flexible manner so as to operate at both the Remote and Base stations. The TDMA Framer should be given priority access to the Cell Pool RAM by control of the PP block whenever data is to be stored or retrieved. Transmission by the Framer should be controlled by an internal table, which is setup by the Supervisory MAC functions running in software at the v851.
While there has been described and illustrated a method of utilizing , it will be apparent to those skilled in the art that modifications and variations are possible without deviating from the broad principle and spirit of the invention which shall be limited solely by the scope of the claims appended hereto. | A queue management method for a wireless asynchronous transfer mode Network Interface Card (NIC) for integrating computers and other electronic equipment to a Wireless Asynchronous Transfer Mode (WATM) network is constructed so as to efficiently exchange data between a host and the wireless network. In addition to providing both ATM and AAL layer transfer protocols, the NIC also provides Data Link Control (DLC), Media Access Control (MAC), and Radio Physical (RPhy) layers as well. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to devices for cleaning the inner walls of tubes and, in particular, to fluid driven projectiles used for cleaning condenser tubing and the like.
It is known that the cleaning of the inner walls of condensers and similar tubes can often be facilitated by driving a projectile having an attached scraper element through a tube with sufficient force so that the scraper element removes mud, slime, scale or other accumulated material from the tube wall. These scraper elements usually consist of one or more blades, bristles, or pieces of wire which extend perpendicularly from a forward elongated body section of the projectile so that, when the body section is disposed longitudinally in the tube, the scraper element is in contact with the tube wall. The body section, itself, is connected to a rearward head or terminal section which is usually cylindrical in shape and of a diameter that is somewhat less than the inner diameter of the tube. Thus, when the projectile is inserted, body first, into the tube opening and when sufficient fluid pressure is exerted on the rearward surface of the terminal section, the projectile will be driven before this fluid pressure through the length of the tube. In this way, the interior of the tube is cleaned by the projectile without need of any attached and externally manipulated lines or handles. Tube cleaning projectiles of this nature are described, for example, in U.S. Pat. Nos. 1,598,771, 2,170,997, and 2,734,208.
It is desirable that the diameter of the terminal section should approach the inner diameter of the tube, since where the gap between the terminal section and the inner wall of the tube is excessive, a large part of the propelling fluid may leak past the terminal section so that the fluid is lost for the purpose of driving the projectile. Notwithstanding the importance of minimizing the amount of fluid pressure which is lost in this manner, it is found that the maintenance of relatively tight seal between the projectile and the inner wall of the tube may not be feasible with many of the tube cleaning projectiles currently in use. That is, where the edge of the terminal sections of these projectiles is in close proximity to the tube wall there may be a danger that the forward motion of the projectile will be obstructed by irregularities in the tube wall. These irregularities may consist of dents in the tube wall or, as is more commonly the case, of insert obstructions, which are plastic tubular inserts placed in the tube at its opening for tube protection purposes. These insert obstructions abut the inner wall of the tube over a portion of its length and thereby effectively reduce the inner diameter of a tube over that length so as to make certain types of projectiles inefficient.
For example, the rigid, substantially flat terminal section shown in the projectile disclosed in U.S. Pat. No. 2,170,997 would not bend so as to pass an obstruction. When such a projectile is used to clean a tube in which an insert obstruction has been emplaced, the diameter of its terminal section must be less than that of the inner diameter of the insert obstruction. Thus, after the projectile passes the insert obstruction, the gap between the edge of the terminal section and the tube wall would increase so as to result in a loss of fluid pressure on the terminal section.
The projectile disclosed in U.S. Pat. No. 1,587,771, on the other hand, has a terminal section which is flared back so that, if sufficient fluid pressure were applied to the terminal section, it might be possible to axially compress or crush the terminal section so as to allow it to pass over an obstruction. There is, however, no indication that the terminal section disclosed in this patent has any feature which would enable it to recover its original form after it had been compressed in this manner so that fluid pressure might thereafter be lost by reason of the resulting deformation in the terminal section.
U.S. Pat. No. 2,734,208 discloses a projectile in which a rubber ring extends perpendicularly outward from the peripheral edge of the terminal section. While this ring may flex and then recover its original shape, certain disadvantages may also be associated with this design. That is, because it extends perpendicularly outward from the terminal section, the rubber ring may be pressed by the fluid on its rear side against an obstruction so that the flexing of the ring to the extent which would be necessary to bypass that obstruction might be impeded or prevented.
It is therefore an object of the present invention to provide a tube cleaning projectile which has a terminal section that has a sufficiently tight seal with the inner wall of the tube so as to allow for efficient use of its propelling fluid but which also easily flexes so as to allow it to pass obstructions in the tube.
SUMMARY OF THE INVENTION
The present invention is a tube cleaning projectile in which a rubber skirt extends outwardly and rearwardly from the terminal section of the projectile so as to allow the projectile to pass over obstructions in the tube wall without permitting excessive propelling fluid to leak past the terminal section. The terminal section is preferably formed of a cup-shaped rubber annulus which is inserted between two rigid perforated discs on a rearward axial extension of the body section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the projectile of the present invention;
FIG. 2 is a partially cut away view of the projectile shown in FIG. 1; and
FIG. 3 is a perspective view of the projectile showing the parts of the terminal section in a disassembled form.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the tube cleaning projectile P of the present invention may be propelled through a tube, the inner wall of which is shown at 2. The projectile has a body section 3 to which there is attached one or more cleaning or scraping elements such as scraper blades 4 and 5. Any of the large number of body and depending cleaning elements which are disclosed in the prior art may be used with this projectile. It is found, however, that particularly good results are obtained with the projectile of the present invention when the body section and scraper element arrangement are similar to those disclosed in the aforementioned U.S. Pat. No. 2,734,208. Accordingly, the contents of that patent are incorporated herein by reference.
Also shown in FIG. 1 is the rearward terminal section 6 of the projectile. Like other tube cleaning projectiles, pressure from fluid as at 7 is exerted on the rearward surface of terminal section 6 and drives the projectile forward through the tube 2 with sufficient force so that the blades 4 and 5 remove mud or other objectionable material as at 8. FIG. 1 also shows that the rearward terminal 6 includes a central rigid washer 9 and a rearwardly an outwardly extending rubber skirt 10. The skirt 10 has a plurality of peripheral grooves as at 11, which grooves facilitate its flexing and passage over tube wall obstructions.
FIGS. 2 and 3 show, in greater detail, the rearward terminal section 6 and the means by which this section is attached to the body section 3. The body section 3 has a rearward extension 12 of rearwardly increasing diameter. The rubber skirt 10 is an integral part of a cup-shaped rubber annulus 13 and the rigid washer 9 and the rubber annulus 13 are arranged on the extension 12 so that the extension first passes through the rigid washer 9, then through the rubber annulus 13, and then through a second rigid washer 14. The rubber annulus 13 and the rigid washers 9 and 14 are retained on the extension 12 between an annular crimp 15 on the extension and an annular shoulder 16 on the body 3. There is also a central bore 17 in extension 12. This bore 17 serves as a recess into which a nipple on a fluid gun, which is commonly used to insert the projectile into a tube, is inserted. It is also believed that the fluid pressure which is exerted on the forward wall of this bore may tend to help stabilize the forward movement of the projectile. Also shown in FIG. 2 is an insert obstruction 18. AS was explained earlier, this insert obstruction is a plastic tube which is commonly inserted in the end of a condenser tube such as tube 2 at the opening of that tube. While many conventional tube cleaning projectiles pass such insert obstructions only with difficulty, with the projectile of the present invention the rubber skirt 10 flexes so as to allow the projectile to easily pass the insert obstruction 18. When the obstruction is passed, the rubber shirt 10 is axially expanded by fluid pressure so that a seal is formed with the inner wall of the tube 2 in the manner shown in FIG. 1. It is also noted that flexing of the rubber skirt 10 also allows the projectile to easily pass other types of obstructions such as tube wall dents.
So as to better illustrate the unique advantages of this projectile, arrows representing some of the forces being exerted on the projectile by the fluid are included in FIG. 2. It will be observed that the fluid not only pushes the projectile forward but that it also controls the flexing of the rubber skirt 10 so as to allow the projectile to easily pass tube obstructions while at the same time maintaining a desirably tight seal with the tube wall. | A fluid propelled tube cleaning projectile in which the rearward head or terminal section has an outward and rearwardly extending rubber skirt, preferably formed as a cup-shaped rubber annulus which is inserted between two rigid perforated discs on a rearward axial extension of the body section of the projectile. | 1 |
This application is a continuation of application Ser. No. 10/004,956, filed Dec. 5, 2001, now U.S. Pat. No. 6,722,440, which claims the benefit of U.S. Provisional Application Ser. No. 60/251,293, filed Dec. 5, 2000. U.S. Pat. No. 6,722,440 is also a continuation-in-part of U.S. application Ser. No. 09/378,384, filed on Aug. 20, 1999, now U.S. Pat. No. 6,347,949, which claims the benefit of U.S. Provisional Application Ser. No. 60/097,449, filed on Aug. 21, 1998.
BACKGROUND OF THE INVENTION
The present invention relates to the field of well completion assemblies for use in a wellbore. More particularly, the invention provides a method and apparatus for completing and producing from multiple mineral production zones, independently or in any combination.
The need to drain multiple-zone reservoirs with marginal economics using a single well bore has driven new downhole tool technology. While many reservoirs have excellent production potential, they cannot support the economic burden of an expensive deepwater infrastructure. Operators needed to drill, complete and tieback subsea completions to central production facilities and remotely monitor, produce and manage the drainage of multiple horizons. This requires rig mobilization (with its associated costs running into millions of dollars) to shut off or prepare to produce additional zones from the central production facility.
Another problem with existing technology is its inability to complete two or more zones in a single well while addressing fluid loss control to the upper zone when running the well completion hardware. In the past, expensive and often undependable chemical fluid loss pills were spotted to control fluid losses into the reservoir after perforating and/or sand control treatments. A concern with this method when completing upper zones is the inability to effectively remove these pills, negatively affecting the formation and production potential and reducing production efficiency. Still another problem is economically completing and producing from different production zones at different stages in a process, and in differing combinations. The existing technology dictates an inflexible order of process steps for completion and production.
Prior systems required the use of a service string, wire line, coil tubing, or other implement to control the configuration of isolation valves. Utilization of such systems involves positioning of tools down-hole. Certain disadvantages have been identified with the systems of the prior art. For example, prior conventional isolation systems have had to be installed after the gravel pack, thus requiring greater time and extra trips to install the isolation assemblies. Also, prior systems have involved the use of fluid loss control pills after gravel pack installation, and have required the use of through-tubing perforation or mechanical opening of a wireline sliding sleeve to access alternate or primary producing zones. In addition, the installation of prior systems within the wellbore require more time consuming methods with less flexibility and reliability than a system which is installed at the surface. Each trip into the wellbore adds additional expense to the well owner and increases the possibility that tools may become lost in the wellbore requiring still further operations for their retrieval.
While pressure actuated valves have been used in certain situations, disadvantages have been identified with such devices. For example, prior pressure actuated valves had only a closed position and an open position. Thus, systems could not reliably use more than one such valve, since the pressure differential utilized to shift the first valve from the closed position to the open would be lost once the first valve was opened. Therefore, there could be no assurance all valves in a system would open.
There has therefore remained a need for an isolation system for well control purposes and for wellbore fluid loss control, which combines simplicity, reliability, safety and economy, while also affording flexibility in use.
SUMMARY OF THE INVENTION
The present invention provides a system which allows an operator to, perforate, complete, and produce multiple production zones from a single well in a variety of ways allowing flexibility in the order of operation. An isolation system of the present invention does not require tools to shift the valve and allows the use of multiple pressure actuated valves in a production assembly.
According to one aspect of the invention, after a zone is completed, total mechanical fluid loss is maintained and the pressure-actuated circulating (PAC) and/or pressure-actuated device (PAD) valves are opened with pressure from the surface when ready for production. This eliminates the need to rely on damaging and sometimes non-reliable fluid loss pills being spotted in order to control fluid loss after the frac or gravel pack on an upper zone (during the extended time process of installing completion production hardware).
According to another aspect of the present invention, the economical and reliable exploitation of deepwater production horizons that were previously not feasible are within operational limits of a system of the invention.
A further aspect of the invention provides an isolation sleeve assembly which may be installed inside a production screen and thereafter controlled by generating a pressure differential between the valve interior and exterior.
According to a still another aspect of the invention, there is provided a string for completing a well, the string comprising: a base pipe comprising a hole; at least one packer in mechanical communication with the base pipe; at least one screen in mechanical communication with the base pipe, wherein the at least one screen is proximate the hole in the base pipe; an isolation pipe concentric within the base pipe and proximate to the hole in the base pipe, wherein an annulus is defined between the base pipe and the isolation pipe; and an annulus-to-annulus valve in mechanical communication with the base pipe and the isolation pipe.
Another aspect of the invention provides a system for completing a well, the system comprising: a first string comprising: a first base pipe comprising a hole, at least one first packer in mechanical communication with the first base pipe, at least one first screen in mechanical communication with the first base pipe, wherein the at least one first screen is proximate the hole in the first base pipe, a first isolation pipe concentric within the first base pipe and proximate to the hole in the first base pipe, wherein a first annulus is defined between the first base pipe and the first isolation pipe, and a first annulus-to-annulus valve in mechanical communication with the first base pipe and the first isolation pipe; and a second string which is stingable into the first string, the second string comprising: a second base pipe comprising a hole, at least one second screen in mechanical communication with the second base pipe, wherein the at least one second screen is proximate the hole in the second base pipe, a second isolation pipe concentric within the second base pipe and proximate to the hole in the second base pipe, wherein a second annulus is defined between the second base pipe and the second isolation pipe, and a second annulus-to-annulus valve in mechanical communication with the second base pipe and the second isolation pipe.
According to an aspect of the invention, there is provided a system for completing a well, the system comprising: a first string comprising: a first base pipe comprising a hole, at least one first packer in mechanical communication with the first base pipe, at least one first screen in mechanical communication with the first base pipe, wherein the at least one first screen is proximate the hole in the first base pipe, a first isolation pipe concentric within the first base pipe and proximate to the hole in the first base pipe, wherein a first annulus is defined between the first base pipe and the first isolation pipe, and a first annulus-to-annulus valve in mechanical communication with the first base pipe and the first isolation pipe; and a second string which is stingable into the first string, the second string comprising: a second base pipe comprising a hole, at least one second screen in mechanical communication with the second base pipe, wherein the at least one second screen is proximate the hole in the second base pipe, a second isolation pipe concentric within the second base pipe and proximate to the hole in the second base pipe, wherein a second annulus is defined between the second base pipe and the second isolation pipe, and a second annulus-to-annulus valve in mechanical communication with the second base pipe and the second isolation pipe; and a third string which is stingable into the second string, the third string comprising: a third base pipe comprising a hole, at least one third screen in mechanical communication with the third base pipe, wherein the at least one third screen is proximate the hole in the third base pipe, a third isolation pipe concentric within the third base pipe and proximate to the hole in the third base pipe, wherein a third annulus is defined between the third base pipe and the third isolation pipe, and a third annulus-to-annulus valve in mechanical communication with the third base pipe and the third isolation pipe.
According to a further aspect of the invention, there is provided a method for completing multiple zones, the method comprising: setting a first string in a well proximate a first production zone, wherein the first string comprises: a first base pipe comprising a hole, at least one first packer in mechanical communication with the first base pipe, at least one first screen in mechanical communication with the first base pipe, wherein the at least one first screen is proximate the hole in the first base pipe, a first isolation pipe concentric within the first base pipe and proximate to the hole in the first base pipe, wherein a first annulus is defined between the first base pipe and the first isolation pipe, and a first annulus-to-annulus valve in mechanical communication with the first base pipe and the first isolation pipe; performing at least one completion operation through the first string; isolating the first production zone with the first string; and producing fluids from the first production zone.
According to a further aspect of the invention, there is provided a method for completing multiple zones, the method comprising: setting a first string in a well proximate a first production zone, wherein the first string comprises: a first base pipe comprising a hole, at least one first packer in mechanical communication with the first base pipe, at least one first screen in mechanical communication with the first base pipe, wherein the at least one first screen is proximate the hole in the first base pipe, a first isolation pipe concentric within the first base pipe and proximate to the hole in the first base pipe, wherein a first annulus is defined between the first base pipe and the first isolation pipe, and a first annulus-to-annulus valve in mechanical communication with the first base pipe and the first isolation pipe; performing at least one completion operation through the first string; isolating the first production zone with the first string; and producing fluids from the first production zone; stinging a second string into the first string and setting the second string proximate a second production zone, wherein the second string comprises: a second base pipe comprising a hole, at least one second screen in mechanical communication with the second base pipe, wherein the at least one second screen is proximate the hole in the second base pipe, a second isolation pipe concentric within the second base pipe and proximate to the hole in the second base pipe, wherein a second annulus is defined between the second base pipe and the second isolation pipe, and a second annulus-to-annulus valve in mechanical communication with the second base pipe and the second isolation pipe; performing at least one completion operation through the second string; and producing fluids from the second production zone through the second string.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is better understood by reading the following description of non-limitative embodiments with reference to the attached drawings wherein like parts in each of the several figures are identified by the same reference characters, and which are briefly described as follows.
FIGS. 1A through 1I illustrate a cross-sectional, side view of first and second isolation strings.
FIGS. 2A through 2L illustrate a cross-sectional, side view of first, second and third isolation strings, wherein the first and second strings co-mingle production fluids.
FIGS. 3A through 3K illustrate a cross-sectional, side view of first, second and third isolation strings, wherein the second and third strings co-mingle production fluids.
FIGS. 4A through 4N illustrate a cross-sectional, side view of first, second, third and fourth isolation strings, wherein the first and second strings co-mingle production fluids and the third and fourth strings co-mingle production fluids.
FIGS. 5A through 5E are a cross-sectional side view of a pressure actuated device (PAD) valve shown in an open configuration.
FIGS. 6A through 6E are a cross-sectional side view of the PAD valve of FIG. 5A through 5E shown in a closed configuration so as to restrict flow through the annulus.
FIGS. 7A through 7D are a side, partial cross-sectional, diagrammatic view of a pressure actuated circulating (PAC) valve assembly in a locked-closed configuration. It will be understood that the cross-sectional view of the other half of the production tubing assembly is a mirror image taken along the longitudinal axis.
FIGS. 8A through 8D illustrate the isolation system of FIG. 7 in an unlocked-closed configuration.
FIGS. 9A through 9D illustrate the isolation system of FIG. 8 in an open configuration.
FIG. 10 is a cross-sectional, diagrammatic view taken along line A—A of FIG. 9C showing the full assembly.
FIGS. 11A through 11D illustrate a cross-sectional side view of a first isolation string.
FIGS. 12A through 12I illustrate a cross-sectional side view of a second isolation string stung into the first isolation string shown in FIG. 11 .
FIGS. 13A through 13L illustrate a cross-sectional side view of a third isolation string stung into the second isolation string shown in FIG. 12 , wherein the first isolation string is also shown.
FIGS. 14A through 14L illustrate a cross-sectional side view of the first, second and third isolation strings shown in FIGS. 11 through 13 , wherein a production string is stung into the third isolation string.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, as the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION OF THE INVENTION
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to FIGS. 1A through 1I , there is shown a system for production over two separate zones. A first isolation string 11 is placed adjacent the first production zone 1 . A second isolation string 22 extends across the second production zone 2 . The first isolation string 11 enables gravel pack, fracture and isolation procedures to be performed on the first production zone 1 before the second isolation string 22 is placed in the well. After the first production zone 1 is isolated, the second isolation string 22 is stung into the first isolation string 11 . Without running any tools on wire line or coil tubing to manipulate any of the valves, the second isolation string 22 enables gravel pack, fracture and isolation of the second production zone 2 . The first and second isolation strings 11 and 22 operate together to allow simultaneous production of zones 1 and 2 without co-mingling the production fluids. The first production zone 1 produces fluid through the interior of the production pipe or tubing 5 while the second production zone 2 produces fluid through the annulus between the production tubing 5 and the well casing (not shown).
The first isolation string 11 comprises a production screen 15 which is concentric about a base pipe 16 . At the lower end of the base pipe 16 there is a lower packer 10 for engaging the first isolation string 11 in the well casing (not shown). Within the base pipe 16 , there is a isolation or wash pipe 17 which has an isolation valve 18 therein. A pressure-actuated device (PAD) valve 12 is attached to the tops of both the base pipe 16 and the isolation pipe 17 . The PAD valve 12 allows fluid communication through the annuluses above and below the PAD valve. A pressure-actuated circulating (PAC) valve 13 is connected to the top of the PAD valve 12 . The PAC valve allows fluid communication between the annulus and the center of the string. Further, an upper packer 19 is attached to the exterior of the PAD valve 12 through a further section of base pipe 16 . This section of base pipe 16 has a cross-over valve 21 which is used to communicate fluid between the inside and outside of the base pipe 16 during completion operations.
Once the first isolation string 11 is set in the well casing (not shown) by engaging the upper and lower packers 19 and 10 , fracture and gravel pack operations are conducted or may be conducted on the first production zone. To perform a gravel pack operation, a production tube (not shown) is stung into the top of a sub 14 attached to the top of the PAC valve 13 . Upon completion of the gravel pack operation, the isolation valve 18 and the PAD valve 12 are closed to isolate the first production zone 1 . The tubing is then withdrawn from the sub 14 . The second isolation string 22 is then stung into the first isolation string 11 . The second isolation string comprises a isolation pipe 27 which stings all the way into the sub 14 of the first isolation string 11 . The second isolation string 22 also comprises a base pipe 26 which stings into the upper packer 19 of the first isolation string 11 . The second isolation string 22 also comprises a production screen 25 which is concentric about the base pipe 26 . A PAD valve 23 is connected to the tops of the base pipe 26 and isolation pipe 27 . The isolation pipe 27 also comprises isolation valve 28 . Attached to the top of the PAD valve 23 is a sub 30 and an upper packer 29 which is connected through a section of pipe. Production tubing 5 is shown stung into the sub 30 . The section of base pipe 26 between the packer 29 and the PAD valve 23 also comprises a cross-over valve 31 .
Since the second isolation string 22 stings into the upper packer 19 of the first isolation string 11 , it has no need for a lower packer. Further, since the first isolation string 11 has been gravel packed and isolated, the second production zone 2 may be fractured and gravel packed independent of the first production zone 1 . As soon as the completion procedures are terminated, the isolation valves 28 and the PAD valve 23 are closed to isolate the second production zone 2 .
The production tubing 5 is then stung into the sub 30 for production from either or both of zones 1 or 2 . For example, production from zone 1 may be accomplished simply by opening isolation valve 18 and allowing production fluid from zone 1 to flow through the center of the system up through the inside of production tubing 5 . Alternatively, production from only zone 2 may be accomplished by opening isolation valve 28 to similarly allow production fluids from zone 2 to flow up through the inside of production tubing 5 .
Non-commingled simultaneous production is accomplished by closing isolation valve 18 and opening PAD valve 12 and PAC valve 13 to allow zone 1 production fluids to flow to the inside of the system and up through the center of production tubing 5 . At the same time, PAD valve 23 may be opened to allow production fluids from zone 2 to flow through the annulus between production tubing 5 and the casing.
The first isolation string 11 comprises a PAD valve 12 and a PAC valve 13 . The second isolation string 22 comprises a PAD valve 23 but does not comprise a PAC valve. PAD valves enable fluid production through the annulus formed on the outside of a production tube. PAC valves enable fluid production through the interior of a production tube. These valves are discussed in greater detail below.
Referring to FIGS. 2A through 2L , an isolation system is shown comprising three separate isolation strings. In this embodiment of the invention, the first production string 11 comprises a lower packer 10 and a base pipe 16 which is connected to the lower packer 10 . A production screen 15 is concentric about the base pipe 16 . A isolation pipe 17 extends through the interior of the base pipe 16 and has an isolation valve 18 thereon. The PAD valve 12 of the first isolation string is attached to the tops of the base pipe 16 and isolation pipe 17 . In this embodiment of the invention, a sub 14 is attached to the top of the PAD valve 12 . The first isolation string 11 also comprises an upper packer 19 which is connected to the top of the PAD valve 12 through a length of base pipe 16 . The length of base pipe 16 has therein a cross-over valve 21 .
The second isolation string 22 is stung into the first isolation string 11 and comprises a base pipe 26 with a production screen 25 therearound. Within the base pipe 26 , there is a isolation pipe 27 which is stung into the sub 14 of the first isolation string 11 . The isolation pipe 27 comprises isolation valve 28 . Further, the base pipe 26 is stung into the packer 19 of the first isolation string 11 . The second isolation string 22 comprises a PAD valve 23 which is attached to the tops of the base pipe 26 and isolation pipe 27 . A PAC valve 24 is attached to the top of the PAD valve 23 . Further, a sub 30 is attached to the top of the PAC valve 24 . An upper packer 29 is attached to the top of the PAD valve 23 through a section of base pipe 26 which further comprises a cross-over valve 31 .
The third isolation string 32 is stung into the top of the second isolation string 22 . The third isolation string 32 comprises a base pipe 36 with a production screen 35 thereon. Within the base pipe 36 , there is a isolation pipe 37 which has an isolation valve 38 therein. Attached to the tops of the base pipe 36 and isolation pipe 37 , there is a PAD valve 33 . A sub 40 is attached to the top of the PAD valve on the interior, and a packer 39 is attached to the exterior of the PAD valve 33 through a section of base pipe 36 . A production tubing 5 is stung into the sub 40 .
The first isolation string 11 comprises a PAD valve 12 but does not comprise a PAC valve. The second isolation string 22 comprises both a PAD valve 23 and a PAC valve 24 . The third isolation string 32 only comprises a PAD valve 33 but does not comprise a PAC valve. This production system enables sequential grave pack, fracture and isolation of zones 1 , 2 and 3 . Also, this system enables fluid from production zones 1 and 2 to be co-mingled and produced through the interior of the production tubing, while the fluid from the third production zone is produced through the annulus around the exterior of the production tube.
The co-mingling of fluids produced by the first and second production zones is effected as follows: PAD valves 12 and 23 are opened to cause the first and second production zone fluids to flow through the productions screens 15 and 25 and into the annulus between the base pipes 16 and 26 and the isolation pipes 17 and 27 . This co-mingled fluid flows up through the opened PAD valves 12 and 23 to the bottom of the PAC valve 24 . PAC valve 24 is also opened to allow this co-mingled fluid of the first and second production zones 1 and 2 to flow from the annulus into the center of the base pipes 16 and 26 and the sub 30 . All fluid produced by the first and second production zones through the annulus is forced into the production tube 5 interior through the open PAC valve 24 .
Production from the third production zone 3 is effected by opening PAD valve 33 . This allows production fluids to flow up through the annulus between the base pipe 36 and the isolation pipe 37 , up through the PAD valve 33 and into the annulus between the production tube 5 and the well casing (not shown).
Referring to FIGS. 3A through 3K , a system is shown wherein a first isolation string 11 comprises a PAD valve 12 and a PAC valve 13 . This first isolation string 11 is similar to that previously described with reference to FIG. 1 . The second isolation string 22 comprises only a PAD valve 23 and is similar to the second isolation string described with reference to FIG. 1 . The third isolation string 32 comprises only a PAD valve 33 but no PAC valve and is also similar to the second isolation string described with reference to FIG. 1 . This configuration enables production from zone 1 to pass through the PAC valve into the interior of the annulus of the production tubing. The fluids from production zones two and three co-mingle and are produced through the annulus about the exterior of the production tube.
The co-mingling of fluids produced by the second and third production zones is effected as follows: Opening PAD valves 23 and 33 creates an unimpeded section of the annulus. Fluids produced through PAD valves 23 and 33 are co-mingled in the annulus.
Referring to FIGS. 4A through 4N , a system is shown comprising four isolation strings. The first isolation string 11 comprises a PAD valve 12 but no PAC valve. The second isolation string 22 comprises a PAD valve 23 and a PAC valve 24 . The third isolation string 32 comprises a PAD valve 33 but does not comprise a PAC valve. Similarly the fourth isolation string 42 comprises a PAD valve 43 but does not comprise a PAC valve. In this particular configuration, production fluids from zones one and two are co-mingled for production through the PAC valve into the interior of the production tube 5 . The fluids from production zones three and four are co-mingled for production through the annulus formed on the outside of the production tube 5 .
In this embodiment, the first isolation string 11 is similar to the first isolation string shown in FIG. 2 . The second isolation string 22 is also similar to the second isolation string shown in FIG. 2 . The third isolation string is also similar to the third isolation string shown in FIG. 2 . However, rather than having a production tubing 5 stung into the top of the third isolation string, the embodiment shown in FIG. 4 , comprises a fourth isolation string 42 . The fourth isolation string comprises a base pipe 46 with a production screen 45 therearound. On the inside of the base pipe 46 , there is a isolation pipe 47 which has an isolation valve 48 . Attached to the tops of the base pipe 46 and the isolation pipe 47 , there is a PAD valve 43 . To the interior of the top of the PAD valve 43 , there is attached a sub 50 . To the exterior of the PAD valve 43 , there is attached through a section of base pipe 46 , an upper packer 49 , wherein the section of base pipe 46 comprises a cross-over valve 51 . A production tubing 5 is stung into the sub 50 .
Referring to FIGS. 5A through 5E and 6 A through 6 E, detailed drawings of a PAD valve are shown. In FIG. 5 , the valve is shown in an open position and in FIG. 6 , the valve is shown in a closed position. In the open position, the valve enables fluid communication through the annulus between the interior and exterior tube of the isolation string. Essentially, these interior and exterior tubes are sections of the base pipe 16 and the isolation pipe 17 . The PAD valve comprises a shoulder 52 that juts into the annulus between two sealing lands 58 . The shoulder 52 is separated from each of the sealing lands 58 by relatively larger diameter troughs 60 . The internal diameters of the shoulder 52 and the sealing lands 58 are about the same. A moveable joint 54 is internally concentric to the shoulder 52 and the sealing land 58 . The moveable joint 54 has a spanning section 62 and a closure section 64 , wherein the outside diameter of the spanning section 62 is less than the outside diameter of the closure section 64 .
The valve is in a closed position, when the valve is inserted in the well. The PAD valve is held in the closed position by a shear pin 55 . A certain change in fluid pressure in the annulus will cause the moveable joint 54 to shift, opening the PAD valve by losing the contact between the joint 54 and the shoulder 52 . Since the relative diameters of the spanning section 62 and closure section 64 are different, the annulus pressure acts on the moveable joint 54 to slide the moveable joint 54 to a position where the spanning section 62 is immediately adjacent the shoulder 52 . Since the outside diameter of the spanning section 62 is less than the inside diameter of the shoulder 52 , fluid flows freely around the shoulder 52 and through the PAD valve.
As shown in FIG. 6 , in the closed position, the PAD valve restricts flow through the annulus. Here, the PAD valve has contact between the shoulder 52 and the moveable joint 54 , forming a seal to block fluid flow through the annulus at the PAD valve.
Referring to FIGS. 7A through 7D , there is shown a production tubing assembly 110 according to the present invention. The production tubing assembly 110 is mated in a conventional manner and will only be briefly described herein. Assembly 110 includes production pipe 140 that extends to the surface and a production screen assembly 112 with PAC valve assembly 108 controlling fluid flow through the screen assembly. In a preferred embodiment production screen assembly 112 is mounted on the exterior of PAC valve assembly 108 . PAC valve assembly 108 is interconnected with production tubing 140 at the uphole end by threaded connection 138 and seal 136 . Similarly on the downhole end 169 , PAC valve assembly 108 is interconnected with production tubing extension 113 by threaded connection 122 and seal 124 . In the views shown, the production tubing assembly 110 is disposed in well casing 111 and has inner tubing 114 , with an internal bore 115 , extending through the inner bore 146 of the assembly.
The production tubing assembly 110 illustrates a single preferred embodiment of the invention. However, it is contemplated that the PAC valve assembly according to the present invention may have uses other than at a production zone and may be mated in combination with a wide variety of elements as understood by a person skilled in the art. Further, while only a single isolation valve assembly is shown, it is contemplated that a plurality of such valves may be placed within the production screen depending on the length of the producing formation and the amount of redundancy desired. Moreover, although an isolation screen is disclosed in the preferred embodiment, it is contemplated that the screen may include any of a variety of external or internal filtering mechanisms including but not limited to screens, sintered filters, and slotted liners. Alternatively, the isolation valve assembly may be placed without any filtering mechanisms.
Referring now more particularly to PAC valve assembly 108 , there is shown outer sleeve upper portion 118 joined with an outer sleeve lower portion 116 by threaded connection 128 . For the purpose of clarity in the drawings, these openings have been shown at a 45° inclination. Outer sleeve upper portion 118 includes two relatively large production openings 160 and 162 for the flow of fluid from the formation when the valve is in an open configuration. Outer sleeve upper portion 118 also includes through bores 148 and 150 . Disposed within bore 150 is shear pin 151 , described further below. The outer sleeve assembly has an outer surface and an internal surface. On the internal surface, the outer sleeve upper portion 118 defines a shoulder 188 ( FIG. 7C ) and an area of reduced wall thickness extending to threaded connection 128 resulting in an increased internal diameter between shoulder 188 and connection 128 . Outer sleeve lower portion 116 further defines internal shoulder 189 and an area of reduced internal wall thickness extending between shoulder 189 and threaded connection 122 . Adjacent threaded connection 138 , outer sleeve portion 118 defines an annular groove 176 adapted to receive a locking ring 168 .
Disposed within the outer sleeves is inner sleeve 120 . Inner sleeve 120 includes production openings 156 and 158 which are sized and spaced to correspond to production openings 160 and 162 , respectively, in the outer sleeve when the valve is in an open configuration. Inner sleeve 120 further includes relief bores 154 and 142 . On the outer surface of inner sleeve there is defined a projection defining shoulder 186 and a further projection 152 . Further inner sleeve 120 includes a portion 121 having a reduced external wall thickness. Portion 121 extends down hole and slidably engages production pipe extension 113 . Adjacent uphole end 167 , inner sleeve 120 includes an area of reduced external diameter 174 defining a shoulder 172 .
In the assembled condition shown in FIGS. 7A through 7D , inner sleeve 120 is disposed within outer sleeves 116 and 118 , and sealed thereto at various locations. Specifically, on either side of production openings 160 and 162 , seals 132 and 134 seal the inner and outer sleeves. Similarly, on either side of shear pin 151 , seals 126 and 130 seal the inner sleeve and outer sleeve. The outer sleeves and inner sleeve combine to form a first chamber 155 defined by shoulder 188 of outer sleeve 118 and by shoulder 186 of the inner sleeve. A second chamber 143 is defined by outer sleeve 116 and inner sleeve 120 . A spring member 180 is disposed within second chamber 143 and engages production tubing 113 at end 182 and inner sleeve 120 at end 184 . A lock ring 168 is disposed within recess 176 in outer sleeve 118 and retained in the recess by engagement with the exterior of inner sleeve 120 . Lock ring 168 includes a shoulder 170 that extends into the interior of the assembly and engages a corresponding external shoulder 172 on inner sleeve 120 to prevent inner sleeve 120 from being advanced in the direction of arrow 164 beyond lock ring 168 while it is retained in groove 176 .
The PAC valve assembly of the present invention has three configurations as shown in FIGS. 7 through 9 . In a first configuration shown in FIG. 7 , the production openings 156 and 158 in inner sleeve 120 are axially spaced from production openings 160 and 162 along longitudinal axis 190 . Thus, PAC valve assembly 108 is closed and restricts flow through screen 112 into the interior of the production tubing. The inner sleeve is locked in the closed configuration by a combination of lock ring 168 which prevents movement of inner sleeve 120 up hole in the direction of arrow 164 to the open configuration. Movement down hole is prevented by shear pin 151 extending through bore 150 in the outer sleeve and engaging an annular recess in the inner sleeve. Therefore, in this position the inner sleeve is in a locked closed configuration.
In a second configuration shown in FIGS. 8A through 8D , shear pin 151 has been severed and inner sleeve 120 has been axially displaced down hole in relation to the outer sleeve in the direction of arrow 166 until external shoulder 152 on the inner sleeve engages end 153 of outer sleeve 116 . The production openings of the inner and outer sleeves continue to be axial displaced to prevent fluid flow therethrough. With the inner sleeve axial displaced down hole, lock ring 168 is disposed adjacent reduced outer diameter portion 174 of inner sleeve 120 such that the lock ring may contract to a reduced diameter configuration. In the reduced diameter configuration shown in FIG. 8 , lock ring 168 may pass over recess 176 in the outer sleeve without engagement therewith. Therefore, in this configuration, inner sleeve is in an unlocked position.
In a third configuration shown in FIGS. 9A through 9D , inner sleeve 120 is axially displaced along longitudinal axis 190 in the direction of arrow 164 until production openings 156 and 158 of the inner sleeve are in substantial alignment with production openings 160 and 162 , respectively, of the outer sleeve. Axial displacement is stopped by the engagement of external shoulder 186 with internal shoulder 188 . In this configuration, PAC valve assembly 108 is in an open position.
In the operation of a preferred embodiment, at least one PAC valve according to the present invention is mated with production screen 112 and, production tubing 113 and 140 , to form production assembly 110 . The production assembly according to FIG. 7 with the PAC valve in the locked-closed configuration, is then inserted into casing 111 until it is positioned adjacent a production zone (not shown). When access to the production zone is desired, a predetermined pressure differential between the casing annulus 144 and internal annulus 146 is established to shift inner sleeve 120 to the unlocked-closed configuration shown in FIG. 8 . It will be understood that the amount of pressure differential required to shift inner sleeve 120 is a function of the force of spring 180 , the resistance to movement between the inner and outer sleeves, and the shear point of shear pin 151 . Thus, once the spring force and resistance to movement have been overcome, the shear pin determines when the valve will shift. Therefore, the shifting pressure of the valve may be set at the surface by inserting shear pins having different strengths.
A pressure differential between the inside and outside of the valve results in a greater amount of pressure being applied on external shoulder 186 of the inner sleeve than is applied on projection 152 by the pressure on the outside of the valve. Thus, the internal pressure acts against shoulder 186 of to urge inner sleeve 120 in the direction of arrow 166 to sever shear pin 151 and move projection 152 into contact with end 153 of outer sleeve 116 . It will be understood that relief bore 148 allows fluid to escape the chamber formed between projection 152 and end 153 as it contracts. In a similar fashion, relief bore 142 allows fluid to escape chamber 143 as it contracts during the shifting operation. After inner sleeve 120 has been shifted downhole, lock ring 168 may contract into the reduced external diameter of inner sleeve positioned adjacent the lock ring. Often, the pressure differential will be maintained for a short period of time at a pressure greater than that expected to cause the down hole shift to ensure that the shift has occurred. This is particularly important where more than one valve according to the present invention is used since once one valve has shifted to an open configuration in a subsequent step, a substantial pressure differential is difficult to establish.
The pressure differential is removed, thereby decreasing the force acting on shoulder 186 tending to move inner sleeve 120 down hole. Once this force is reduced or eliminated, spring 180 urges inner sleeve 120 into the open configuration shown in FIG. 9 . Lock ring 168 is in a contracted state and no longer engages recess 176 such the ring now slides along the inner surface of the outer sleeve. In a preferred embodiment spring 180 has approximately 300 pounds of force in the compressed state in FIG. 8 . However, varying amounts of force may be required for different valve configurations. Moreover, alternative sources other than a spring may be used to supply the force for opening. As inner sleeve 120 moves to the open configuration, relief bore 154 allows fluid to escape chamber 155 as it is contracted, while relief bores 148 and 142 allow fluid to enter the connected chambers as they expand.
Shown in FIG. 10 is a cross-sectional, diagrammatic view taken along line A—A of FIG. 9C showing the full assembly.
Although only a single preferred PAC valve embodiment of the invention has been shown and described in the foregoing description, numerous variations and uses of a PAC valve according to the present invention are contemplated. As examples of such modification, but without limitation, the valve connections to the production tubing may be reversed such that the inner sleeve moves down hole to the open configuration. In this configuration, use of a spring 180 may not be required as the weight of the inner sleeve may be sufficient to move the valve to the open configuration. Further, the inner sleeve may be connected to the production tubing and the outer sleeve may be slidable disposed about the inner sleeve. A further contemplated modification is the use of an internal mechanism to engage a shifting tool to allow tools to manipulate the valve if necessary. In such a configuration, locking ring 168 may be replaced by a moveable lock that could again lock the valve in the closed configuration. Alternatively, spring 180 may be disengageable to prevent automatic reopening of the valve.
Further, use of a PAC valve according to the present invention is contemplated in many systems. One such system is the ISO system offered by BJ Services Company U.S.A. (successor to OSCA, Inc.) and described in U.S. Pat. No. 5,609,204; the disclosure therein is hereby incorporated by reference. A tool shiftable valve disclosed in the above patent is a type of isolation valve and may be utilized within the production screens to accomplish the gravel packing operation. Such a valve could be closed as the crossover tool string is removed to isolate the formation. The remaining production valves adjacent the production screen may be pressure actuated valves according to the present invention such that inserting a tool string to open the valves is unnecessary.
FIGS. 11 through 14 illustrate several steps in the construction of an isolation and production system according to an embodiment of the present invention.
FIGS. 11A through 11D show a first isolation string 211 . The isolation string comprises a PAD valve 212 . At the lower end of the isolation string 211 , there is a lower packer 210 and at the upper end of the isolation string 211 there is an upper packer 219 . A base pipe 216 is connected to the lower packer 210 and has a production screen 215 therearound. The isolation string 211 further comprises an isolation valve 218 on a isolation pipe 217 . The PAD valve 212 enables fluid communication through the annulus between the isolation pipe 217 and the isolation string 211 . The first isolation string 211 also comprises a sub 214 attached to the top of the PAD valve 212 . Further, in the base pipe section between the PAD valve 212 and the upper packer 219 , there is a cross-over valve 221 . This configuration of the first isolation string 211 enables the first production zone 1 to be fractured, gravel packed, and isolated through the first isolation string 211 . Upon completion of these procedures, the isolation valve 218 and PAD valve 212 are closed to isolate the production zone 1 .
FIGS. 12A through 12I show cross-sectional, side views of two isolation strings. In particular, a second isolation string 222 is stung inside an isolation string 211 . Isolation string 222 comprises a PAD valve 223 and a PAC valve 224 . The isolation string 211 , shown in this figure, is the same as the isolation string shown in FIG. 11 . After the gravel/pack and isolation function are performed on the first zone with the isolation string 211 , the isolation string 222 is stung into the isolation string 211 . The second isolation string 222 comprises a base pipe 226 having a production screen 225 therearound. The base pipe 226 is stung into the packer 219 of the first isolation string 211 . The second isolation string 222 also comprises a isolation pipe 227 which is stung into the sub 214 of the first isolation string 211 . The isolation pipe 227 also comprises an isolation valve 228 . At the tops of the base pipe 226 and isolation pipe 227 , there is connected a PAD valve 223 . A PAC valve 224 is connected to the top of the PAD valve 223 . Also, a sub 230 is attached to the top of the PAC valve 224 . An upper packer 229 is also connected to the exterior portion of the PAD valve 223 through a section of base pipe 226 which also comprises a cross-over valve 231 .
Referring to FIGS. 13A through 13L , the isolation strings 211 and 222 of FIG. 12 are shown. However, in this figure, a third isolation string 232 is stung into the top of isolation string 222 . In this particular configuration, isolation strings 211 and 222 produce fluid from respective zones 1 and 2 up through the annulus between the isolation strings and the isolation sleeves until the fluid reaches the PAC valve 224 . The co-mingled production fluid from production zones 1 and 2 pass through the PAC valve 224 into the interior of the production string. The production fluids from zone 3 is produced through the isolation string 232 up through the annulus between the isolation string 232 and the isolation pipe 237 . In the embodiment shown in FIG. 13 , the PAD valves 212 , 223 and 233 are shown in the closed position so that all three of the production zones are isolated. Further, the PAC valve 224 in isolation string 222 is shown in a closed position.
The third isolation string 232 comprises a base pipe 236 which is stung into the packer 229 of the second isolation string. The base pipe 236 also comprises a production screen 235 . Inside the base pipe 236 , there is a isolation pipe 237 which is stung into the sub 230 of the second isolation string 222 . The isolation pipe 237 comprises isolation valve 238 . A PAD valve 233 is connected to the tops of the base pipe 236 and isolation pipe 237 . A sub 234 is connected to the top of the PAD valve 233 . An upper packer 239 is also connected through a section of base pipe 236 to the PAD valve 233 . This section of base pipe also comprises a cross-over valve 241 .
Referring to FIGS. 14A through 14L , the isolation strings 211 , 222 and 232 of FIG. 13 are shown. In addition to these isolation strings, a production tube 240 is stung into the top of isolation string 232 . With the production tube 240 stung into the system, pressure differential is used to open PAD valves 212 , 223 , and 233 . In addition, the pressure differential is used to set PAC valve 224 to an open position. The opening of these valves enables co-mingled production from zones 1 and 2 through the interior of the production tube while production from zone 3 is through the annulus on the outside of the production tube 240 .
The packers, productions screens, isolations valves, base pipes, isolations pipes, subs, cross-over valves, and seals may be off-the-shelf components as are well known by persons of skill in the art.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. | An isolation system for producing oil and gas from one or more formation zones and methods of use are provided comprising one or more pressure activated valve and one or more tool shiftable valve. The tool shiftable valve may be actuated before or after actuation of the pressure activated valve. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to a metal-ceramic substrate with at least one ceramic layer, with metallizations on both sides of the ceramic layer wherein the metallizations are directly bonded with the ceramic layer.
Metal-ceramic substrates, in particular copper-ceramic substrates, are used increasingly as a base substrate or printed circuit board in power modules designed for higher operating voltages, e.g. for operating voltages of 600 V and higher. One of the requirements of such power modules is a sufficiently high discharge or partial discharge resistance or stability. This requirement corresponds to the knowledge that partial discharges, which occur during operation of such a module over an extended period, cause electrically conductive paths in the isolating areas of the module, which can weaken the isolation and eventually also cause extreme voltage punctures, resulting in the failure of the respective module.
The requirement for the highest possible partial discharge resistance or stability applies to the entire module, i.e. each individual component of the module must fulfill the requirement for the highest possible partial discharge resistance or stability. Since the respective metal-ceramic substrate is an essential component of the respective module, this requirement also applies to this substrate, although partial discharges that occur only within the metal-ceramic substrate cause no damage to the isolating effect there. The reason for the requirement for each individual component to have the necessary partial discharge resistance or stability is, for example, that it cannot be determined by measurements of the finished module which individual component of the module is responsible for partial discharges in the module.
The measurement of the partial discharge resistance or stability is defined in standard IEC 1278. According to this measuring principle, the respective test piece is first subjected in a first measuring or test phase to an isolation voltage that is considerably higher than the operating voltage and then, in a second measuring or test phase, is first subjected to a reduced, preparatory measuring voltage and finally to the actual measuring or test voltage, at which the partial discharge is then measured. The preparatory or first test voltage is then above the maximum operating voltage of the respective module and the actual test voltage is below the maximum operating voltage of the module. The discharge or partial discharge may not exceed a value of 10 pico Coulomb (10 pC) in this measurement.
In the production of metal-ceramic substrates, a method is known for manufacturing the metallization required for strip conductors, connectors, etc. on a ceramic, e.g. on an aluminum-oxide ceramic, by means of the “direct bonding” process or for metallizations made of copper by means of “DCB” (Direct Copper Bonding) technology, the metallization being formed from metal or copper sheets, the surfaces of which comprise a layer or a coat (hot-melt layer) resulting from a chemical bond between the metal and a reactive gas, preferably oxygen.
In this method, which is described for example in US-PS 37 44 120 and in DE-PS 23 19 854, this layer or coating (hot-melt layer) forms a eutectic with a melting temperature below the melting temperature of the metal (e.g. copper), so that the layers can be bonded to each other by placing the foil on the ceramic and heating all layers, namely by melting the metal or copper essentially only in the area of the hot-melt layer or oxide layer.
The DCB process then comprises, for example, the following process steps:
oxidation of a copper foil so as to produce an even copper oxide layer; placing the copper foil on the ceramic layer; heating the composite to a process temperature between approx. 1025 and 1083° C., e.g. to approx. 1071° C.; cooling to room temperature.
It is an object of the invention is to present a metal-ceramic substrate that reliably complies with the required partial discharge resistance or stability of <10 pC. This object is achieved by a metal-ceramic substrate according to claim 1 .
SUMMARY OF THE INVENTION
In the metal-ceramic substrate according to the invention, the metallizations are formed for example from metal foils, for example from foils made of copper or copper alloys. The bond between the respective ceramic layer and the metallization is then for example achieved using the direct bonding process, for example the DCB process.
“Metal-ceramic substrate” according to the present invention refers generally to a substrate or a sequence of layers comprising at least one ceramic layer and at least one metallization provided on at least one surface side of the ceramic layer. “Bond” according to the present invention is the surface area of the transition between the respective metallization and the ceramic layer, which (surface area) does not exhibit defective spots and on which therefore a direct bond of the metal layer to the ceramic exists.
The metallizations are bonded to the ceramic layer with a bond strength of at least 25 N/cm, which can easily be achieved with DCB technology. The bond strength of the metallizations on the ceramic layer can be determined by a standardized measuring process. For this purpose, a test substrate is manufactured, consisting of one rectangular ceramic layer and one metallization formed by one copper foil applied to one surface side of the ceramic layer by means of DCB technology. In the proximity of one end the ceramic layer is provided crossways with a break-off line, for example by means of a laser. To measure the bond strength, the ceramic layer is broken along the break-off line and then the respective end of the ceramic layer is curved upward. The remainder of the ceramic layer is placed flat on an underlying surface and fixed there. A pull-off force is exerted vertically upward on the end that is curved upward. The bond strength is then the quotient of the vertical force required for detaching or pulling off the metal layer from the ceramic layer and the width of the strip-shaped test substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained below in more detail based on one exemplary embodiment with reference to the drawings, wherein:
FIG. 1 shows a very schematic representation of a metal-ceramic substrate, together with a measuring array for measuring the partial discharge resistance or stability of the substrate;
FIG. 2 shows the time curve for the measuring voltage V M according to the standardized measuring method pursuant to IEC 1287;
FIG. 3 shows a simplified representation of a partial cross section through a metal-ceramic substrate in the bond area between one metallization and the ceramic, namely in the proximity of a defective spot; and
FIGS. 4 and 5 each show a partial representation in cross section and in top view of a metal-ceramic substrate with a structured metallization in the proximity of a defective spot.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, 1 is a metal-ceramic substrate consisting of one ceramic layer 2 , to each side of which one metallization 3 and 4 is applied, respectively. The ceramic layer 2 has a thickness d 1 . The surface F covered by the metallizations 3 and 4 respectively of the two surface sides of the ceramic layer 2 is somewhat smaller in the depicted embodiment than the total surface of said surface sides.
The ceramic layer 2 is made for example of Al 2 O 3 or of a non-oxide ceramic, such as AlN or Si 3 N 4 . Ceramic materials with additives are also suitable for the ceramic layer 2 , for example Al 2 O 3 reinforced with ZrO 2 and/or with additives from the group of ceroxide, yttrium oxide, magnesium oxide and/or calcium oxide, in which case the ceramic material of the ceramic layer 2 then has the following composition, for example:
AI 2 0 3 70-98 percent by weight Zr0 2 2-30 percent by weight and other additives 1-10 percent by weight,
and the other additives are formed by at least one oxide from the following group: ceroxide, yttrium oxide, magnesium oxide and calcium oxide.
The two metallizations 3 and 4 are each formed for example from a copper foil and have a thickness d 2 . Furthermore, the metallizations 3 and 4 are bonded with the ceramic layer 2 by means of a suitable technology, for example by direct bonding technology. If the ceramic layer 2 in this case is made of a non-oxide ceramic, such as AlN or Si 3 N 4 , then this ceramic layer 2 is provided with a surface coating made of Al 2 O 3 at least on the two surface sides, and the maximum thickness of said surface coating is 10 μm. This surface coating then makes it possible, also with the use of the afore-mentioned non-oxide ceramics, to attach the metallizations 3 and 4 flat on the ceramic layer 2 using the DCB process.
FIG. 2 shows the basic curve of the direct current measuring voltage V M applied to the metallizations 3 and 4 during the test of the discharge characteristic or discharge resistance or stability. The entire measuring process essentially comprises the two phases I and II, which are conducted consecutively in time. In the measuring phase I, the measuring voltage V M is increased starting with the time 0 to a value V i (isolation voltage) specified by the measuring method, namely within approximately 10 seconds, then is held at the value V i for a duration T i of approximately 60 seconds and then continually lowered, so that the first measuring phase I is completed after approximately 80 seconds, during which essentially the dielectric strength of the metal-ceramic substrate 1 was tested.
If the metal-ceramic substrate passes this first measuring phase I, then measuring phase II is started automatically, i.e. approximately 10 seconds after the measuring voltage V M in the first measuring phase again has the value zero, by increasing the measuring voltage V M within a pre-defined period, for example within 10 seconds, from zero to the value V 1 and then is held at this value for a time period T 1 of for example 60 seconds. Afterwards, the measuring voltage V M is reduced to a value V 2 and held constantly at this value for a pre-defined duration T 2 . Before expiration of the time period T 2 , the partial discharge is measured in a pre-defined measuring interval T M , which is considerably shorter than the time period T 2 . After this measurement, the measuring voltage V M is again continually reduced until it reaches the value zero.
To ensure that a component or module which uses the metal-ceramic substrate 1 , obviously then with structured metallizations 3 and 4 , as a printed circuit board, on which active and/or passive electric components are provided, also has the required discharge characteristic or discharge or partial discharge resistance or stability as a whole, it is specified that the total partial discharge throughout the duration of the measuring process T M must not exceed 10 pico Coulomb (10 pC).
As FIG. 2 shows, the isolation voltage V i is considerably higher than the voltage V 1 . The latter is also greater than the voltage V 2 , with which the partial discharge stability is then also measured. The absolute values V i , V 1 and V 2 are based on the respective maximum operating voltage of the module containing the metal-ceramic substrate 1 .
The following table lists the voltages V i , V 1 and V 2 for modules with different operating voltages.
Module type
maximum
Maximum
operating
Isolation
Measuring
Measuring
partial
voltage in
voltage V 2
voltage V 2
voltage V 2
discharge
volts
in volts
in volts
in volts
in pC
600
2500
700
500
10
1200
2500
1300
1000
10
1700
4000
1800
1300
10
1800
4000
1900
1400
10
3300
6000
3500
2600
10
6500
10500
6900
5100
10
For the partial discharge resistance or stability and for compliance with the limit value of less than 10 pC for the partial discharge, the thickness d 1 of the ceramic layer 2 is critical, and always based on the type of ceramic material for this layer. The limit value of less than 10 pC for the partial discharge at the voltage V 2 can then easily be complied with if the voltage V 2 and the thickness d 1 conform to the following function:
V 2(<10 pC) ≦6.1 ×d 1 [KV] or d 1 (<10 pC) ≧1/6.1 ×V 2 [KV]
where d 1 is specified in mm and 6.1 is a factor in KV/mm.
Furthermore, the invention is based on the knowledge that the surface area occupied by the metallizations is a further significant parameter affecting the partial discharge resistance or stability and that it is advantageous for this reason to limit the surfaces formed by the metallizations 3 and 4 to a maximum of 110 cm 2 for the respective metal-ceramic substrate 1 of a module.
A further critical parameter for the partial discharge resistance or stability is the existence of any defective spots 5 in the form of hollow spaces at the transition between the respective metallization 3 or 4 and the ceramic layer 2 , although such defective spots with a diameter d 3 smaller than 50 μm and a height h smaller than 50 μm do not affect the partial discharge resistance or stability, as long as the total surface area of the defective spots 5 in relation to the total surface area occupied by the respective metallization 3 or 4 is 5% or less.
In addition to these defective spots 5 formed at the transition between the ceramic layer 2 and the respective metallization 3 or 4 , the partial discharge resistance or stability is also affected by defective spots 6 , which occur for example during structuring of the metallizations 3 and 4 with the use of known technologies, for example etch-masking technology, specifically for example by the fact that the structured metallization forms pits and/or peaks or projections directly on the surface of the ceramic layer 2 , causing areas with an increased electric field strength or a concentration of electric field lines in the ceramic layer, as indicated schematically in FIG. 4 by the lines 7 . This effect of reducing the partial discharge resistance or stability by such defective spots 6 occurring during the structuring can be reduced according to a further finding of the invention if the course of the edge 6 . 1 with the respective defective spot 6 on the surface side of the ceramic layer 2 has a radius of curvature of at least 80 μm.
The invention was described above based on exemplary embodiments. It goes without saying that modifications and variations are possible without abandoning the underlying inventive idea upon which the invention is based.
REFERENCE LIST
1 metal-ceramic substrate
2 ceramic layer
3 , 4 metal layer or metallization
5 , 6 defective spot
6 . 1 edge of defective spot 6
7 field lines
d 1 thickness of the ceramic layer 2
d 2 thickness of the metallizations
d 3 diameter of defective spot
h height of defective spot
T i , T 1 , T 2 time interval
T M duration of measurement
V M measuring voltage
V i , V 1 , V 2 value of the measuring voltage | Disclosed is a metal-ceramic substrate made up of at least one ceramic layer which is provided with metallizations on both faces. In order to obtain a partial discharge resistance of less than 10 pC at a predefined measuring voltage, the thickness of the ceramic layer amounts to about one sixth of the measuring voltage. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to threaded end protectors for pipes and, more particularly, to a composite end protector having an improved mechanical locking arrangement.
2. Description of the Prior Art
The threaded ends of pipe must be protected from damage during storage and transit. Typically, end protectors have been manufactured from plastic, metal or a combination of the two. The threads of all-metal protectors can damage the pipe threads if misapplied. Further, the metal threads of metal protectors do not prevent the exposure of the pipe threads to moisture and, thus, do not prevent corrosion of the pipe protector. All-plastic end protectors, while eliminating the corrosion and thread damage problems, often become loose during prolonged periods due to expansion and contraction of the threads resulting from exposure to temperature extremes. Further, all-plastic protectors tend to become loose or broken due to deformation caused by impact.
Therefore, workers in the art have developed composite end protectors having a threaded plastic member shielding the threaded pipe end and a metal member shielding and reinforcing the plastic inner member. The metal and plastic members of the protector must be so joined together that they do not become separated from each other when the protector experiences impact during storage or transfer of the pipe, or during any of the numerous applications to or removals from the pipe end encountered during normal use. However, any technique used to join the plastic and metal members must permit economical manufacture and assembly of the protector.
Turk U.S. Pat. No. 4,157,100, which issued on June 5, 1979, discloses a composite threaded end protector having a detent in the metal outer member to mechanically join it to the plastic inner member. The metal detent pierces the plastic member to hold the two members together. The friction forces holding the detent in place can be readily overcome by the blows to the end protector which often occur during transit. The Turk disclosure does not indicate how the metal member is placed on the plastic member. If the detent is formed in the metal member before it is forced onto the plastic member, the metal detent may deform the threaded surface of the protector. When the end protector is placed on the pipe, the deformed threaded surface of the plastic member can strip away the grease which must be applied to the threads of the pipe. If the detent is formed by crimping after the metal member is placed on the plastic member, to maintain the integrity of the plastic threads, the crimping operation complicates the production process and thereby increases production costs.
Waldo et al. U.S. Pat. No. 4,487,228, which issued on Dec. 11, 1984, discloses a cup shaped composite end protector. Holes drilled through the metal outer member receive protrusions molded in the plastic inner member to mechanically join the two. The plastic member may be molded in the metal member to ensure proper alignment of the protrusions with the holes. Alternatively, the members can be formed separately and assembled by placing the metal member over the plastic member. The former method of assembly increases the cost of production and the latter method risks the misalignment of the protrusions and the holes. The plastic protrusions of the misaligned protector deform the threads of the protector, which can cause the grease-stripping problem identified above, and can defeat the seal provided by the threads and cause incomplete coupling between the pipe and protector. Further, the plastic protrusions can be sheared off by a heavy impact resulting in separation of the plastic from the metal member.
Coel et al. U.S. Pat. No. 4,126,338, which issued on Nov. 21, 1978, discloses an arrangement for providing mechanical coupling of plastic shaft sections. Protruding wedges having inwardly sloping ramps on the interior surface of the outer member engage complementary preformed recesses in the outer surface of the inner member. A separately formed keyway and axially extending rib are provided on the shaft sections to ensure alignment of each wedge with its corresponding recess.
It is an object of the present invention to provide a composite threaded end protector which has an improved arrangement for mechanically joining the inner and outer members. It is a further object of the present invention to provide a positive locking attachment which will not become dislodged or worn during transit. It is an object of the present invention to provide an arrangement of mechanical joinder which will facilitate proper alignment. Finally, it is an object of the present invention to provide such an improved end protector which can be produced economically.
SUMMARY OF THE INVENTION
The present invention provides a protector for the threaded end of a generally tubular member. The protector includes a member formed from a resilient material that defines a threaded portion that is adapted to threadedly engage a threaded end of the tubular member. The protector also includes a member formed from metal having a surface adapted to confront a corresponding surface of the resilient member. The metal member defines at least one projection on its confronting surface. The resilient member defines at least one recess adapted to receive the projection when the resilient and metal members are placed in predetermined positions relative to each other and the confronting surfaces confront each other. The metal member, the resilient member, the projection and the recess cooperate to secure together the resilient and metal members to form a unit when the projection is received by the recess and the members are in their predetermined positions. The resilient member further defines a channel adapted to receive the projection and guide the projection into the recess as the members are moved toward their predetermined positions.
The present invention also provides a plastic sleeve adapted to be joined with a corresponding metal sleeve to form a protector for the threaded end of a generally tubular member. The plastic sleeve defines a threaded portion on its inner surface. The threaded portion is adapted to threadedly engage a threaded end of the tubular member. The outer surface of the plastic sleeve defines a recess and a channel that extends from one end of the plastic sleeve to a point proximate the recess. The channel defines a ramp adapted to facilitate the transfer of a member from the channel into the recess.
The present invention also provides a plastic sleeve adapted to be joined with a corresponding metal sleeve to form a protector for the threaded end of a generally tubular member. The outer surface of the plastic sleeve defines a threaded portion. The threaded portion is adapted to threadedly engage the threaded end of the tubular member. The inner surface of the plastic sleeve defines a recess and a channel that extends from one end of the plastic sleeve to a point proximate the recess. The channel defines a ramp adapted to facilitate the transfer of a member from the channel into the recess.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of the preferred embodiments can be understood better if reference is made to the drawings, in which:
FIG. 1 is a side elevation view of the preferred internally threaded protector provided by the present invention;
FIG. 2 is a top plan view of the protector shown in FIG. 1;
FIG. 3 is a section view of the end protector shown in FIG. 1 taken along the line III--III of FIG. 2;
FIG. 4 is a section view of the end protector taken along the line IV--IV of FIG. 3;
FIG. 5 is an isometric view, partially cutaway, of the outer metal member of the end protector shown in FIG. 1;
FIG. 6 is an isometric view of the inner plastic member of the end protector shown in FIG. 1;
FIG. 7 is a side elevation view of the preferred externally threaded end protector provided by the present invention;
FIG. 8 is a top plan view of the end protector shown in FIG. 7;
FIG. 9 is a section view of the end protector shown in FIG. 7 taken along the line IX--IX of FIG. 8.
FIG. 10 is an isometric cutaway view of a portion of the plastic member of the protector shown in FIG. 7, showing the approach channel, ramp, and locking recess of the outer plastic member;
FIG. 11 is an isometric view partially cutaway, of the inner metal member of the end protector shown in FIG. 7; and
FIG. 12 is an isometric view partially cutaway, of the outer plastic member of the end protector shown in FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 12 illustrate the preferred embodiments of the present invention.
FIGS. 1 through 6 illustrate an internally threaded end protector 10 which is designed to protect the exterior threads on the end of a pipe. FIGS. 7 through 12 illustrate an externally threaded end protector 20 which is particularly adapted to shield the interior threads of an internally threaded pipe coupler threaded onto the end of an externally threaded pipe.
End protector 10 includes inner plastic member 40 and outer metal member 30. The shock absorbing, nonrusting inner plastic member 40 includes an interior surface 42 having threads 46 which engage the threaded end of the pipe (not shown) and exterior surface 44 having an approach channel 48, ramp 50 and locking recess 52 for facilitating the alignment and mechanical joinder of plastic member 40 to metal member 30. Preferably, metal member 30 is formed from suitably dimensioned metal pipe.
The outer member 30 includes interior surface 32 which confronts and fits closely against the exterior surface 44 of inner member 40. Outer member 30 also includes exterior surface 34. At least one projection or lug 36 partially cut away from member 30 protrudes inwardly from interior surface 32 for mechanical locking engagement with the locking recess 52 to secure the inner and outer members in predetermined positions to form a unit. As shown in FIG. 3, the free edge 33 of lug 36 is held against axial movement in one direction by the perpendicular abutment end 54 of recess 52. Lug 36 is angled inwardly to form a ramp surface 37. All the walls 57 and 54 of recess 52 are perpendicular to the floor 55 of recess 52 to ensure that lug 36 cannot escape from recess 52 radially or toward channel 48. Accordingly, radial movement of members 30 and 40 relative to each other is prevented. Preferably, there are a plurality of lugs 36 and complementary approach channels 48 and recesses 52 spaced in predetermined positions around the diameter of the end protector 10. As will be appreciated by those of ordinary skill in the art, some applications of the present invention will be sufficiently mechanically joined by one lug 36 appropriately positioned in one recess 52.
Inner member 40 includes flange 58 and a stop or lip 56. Outer member 30 includes flange 38 which covers flange 58 of inner member 40. Flanges 58 and 38 overlap the end of the pipe section to which the protector 10 is secured to protect it from damage. The opposite end 35 of outer member 30 defines a stop portion that rests on lip 56 of inner member 40 when members 30 and 40 are joined together. Lip 56 and end 35 cooperate to limit the extent to which member 40 can be inserted into member 30. The outer diameter of inner member 40 at lip 56 is preferably slightly greater than the outer diameter of outer member 30 at end 35 to reduce the possibility of the outer member 30 catching onto an object and being pulled off inner member 40 during transit of the pipe. During the molding process portions of the longitudinal walls of protector 10 set at different times due to the presence of channels 48, causing flange 58 to be non-planar, or "wavy". Accordingly, flange 58 exerts a torque against the pipe end when protector 10 is tightened on a pipe and flange 58 is forced flat against the pipe end, thus sealing the pipe threads against moisture.
Referring to FIG. 6, the approach channel 48 is open at the flanged end of the inner member 40 and defines a ramp 50. Portion 45 is at the same elevation as exterior surface 44. Referring to FIGS. 3 and 5, the free edge 33 of lug 36 is angled toward the flanged end of outer member 30. The channels 48 preferably have perpendicular longitudinal sidewalls to prevent radial slippage of lug 36 during assembly of protector 10. Lug ramp 37 preferably complements approach ramp 50.
To assemble the end protector 10, lugs 36 are aligned with approach channels 48 and the outer member 30, end 35 first, is forced over the inner member 40. The edge 33 of each lug 36 travels along the complementary approach channel 48 until the lug ramp 37 meets the approach ramp 50. As the mating ramps 37 and 50 engage, the continued force applied to press outer member 30 onto inner member 40 deflects portion 45 inward and the lug 36 snaps into locking engagement in recess 52.
The approach channels 48 of the present invention provide an indexing means to ensure proper alignment of each lug 36 with a recess 52 to prevent misalignment of members 30 and 40. In addition, the arrangement described above provides a positive locking engagement which prevents the rotation--that is, radial movement of members 30 and 40 relative to each other--of the inner and outer members relative to each other. Therefore, members 30 and 40 of protector 10 are not susceptible to separation during use, including application to and removal from threaded pipes. The locking engagement of edge 33 against abutment 54 and the cooperation of lip 56 and end 35 prevent axial movement of the members 30 and 40 relative to each other.
Inner member 40 is preferably made of a resilient, durable plastic material, such as high density polyethylene, which can withstand exposure to temperatures ranging from about -50° F. to 150° F. Outer member 30 is made of a rigid material, preferably a metal, such as steel. The metal outer member 30 can be easily and economically produced from steel pipe which is cut to the desired length and pressed into shape. The plastic inner member 40 can be manufactured by injection molding.
FIGS. 7 through 12 illustrate an externally threaded end protector 20. End protector 20 includes outer plastic member 80 having exterior surface 82 and interior surface 84. Threads 86 on the exterior surface 82 engage matching threads on the interior of a pipe coupling (not shown). End protector 20 also includes inner metal member 60 which fits closely against interior surface 84 of outer member 80.
Outer member 80 includes approach channels 88, ramps 90, portions 85, locking recess 92, and abutment ends 94. Locking recesses 92 extend to beveled end 96 to facilitate removal of member 30 from the mold during manufacture. Inner member 60 includes interior and exterior surfaces 64 and 62, and lugs 66 with ramp surfaces 67 and free edges 63. The lugs 66 engage channels 88, ramps 90, recesses 92 and abutment 94 in the same manner as their counterparts on exterior end protector 10. Perpendicular side walls 93 of recesses 92 prevent the escape of lugs 62 from recesses 92 in a radial direction. Perpendicular side walls 89 of channels 88 prevent the escape of lugs 62 from channels 88 in a radial direction while members 60 and 80 are being joined together. The stop or flange 68 of inner member 60 engages and covers the stop or flange 68 of outer member 80. As with flange 58, flange 98 can be made "wavy" to enhance the sealing ability of member 80. Therefore, edges 63, walls 94, and flanges 68 and 98 cooperate to prevent axial movement of members 60 and 80 relative to each other after they are joined together. Referring to FIG. 9, end 96 of inner member 80 is beveled. End 65 of outer member 60 need not engage end 96. | Protectors are provided for both internally and externally threaded ends of a tubular member. Each protector includes a plastic and a metal member. The plastic member of each protector defines threads which are adapted to threadedly engage threads of the tubular member. Each metal member defines a projection that is adapted to be received by a recess formed in the plastic member. Each plastic member defines a channel that guides the metal projection to the recess as the metal and plastic members are joined together. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application having Ser. No. 60/978,983, filed on Oct. 10, 2007, which is incorporated herein by reference.
BACKGROUND
[0002] Hydrocarbon producing formations typically have sand commingled with the hydrocarbons to be produced. For various reasons, it is not desirable to produce the commingled sand to the earth's surface. Thus, sand control completion techniques are used to prevent the production of sand.
[0003] Gravel packing is one method for controlling sand production. Although there are variations, gravel packing usually involves placing a sand screen around the section of the production string containing the production inlets. This section of the production string is aligned with perforations. Gravel slurry, which is typically gravel particulates carried in a viscous transport fluid, is pumped through the tubing into the formation and the annulus between the sand screen and the casing or between the sand screen and the open hole. The deposited gravel holds the sand in place preventing the sand from flowing to the production tubing while allowing the production fluids to be produced therethrough.
[0004] In multi-zone wells or in a well having multiple flow sections, flow control devices have been used to control fluid flow through orifices formed between the tubing bore and an annulus between the tubing and casing. However, if sand face completion equipment including gravel packing is installed, then the annulus is typically filled, which makes it difficult to position such flow control devices in the proximity of sand control equipment. Accordingly, the formation fluid must first flow generally radially through the sand control device before flowing to the flow control device. One option is to install the flow control device inside a tubing bore in the proximity of the production zone. However, this reduces the available flow area for production flow.
[0005] Three-way sub systems with sliding sleeves inside an internal isolation string have also been used for zonal isolation. A screen wrapped sliding sleeve is also a common system. For example, U.S. Pat. No. 3,741,300 discloses a sliding sleeve within a screen assembly. However, the '300 patent describes a 3-way sub system and it is specifically intended for stand alone screen applications (no pumping).
[0006] U.S. Pat. No. 5,337,808 discloses an apparatus where the screen wrapping is placed directly over and around the flow control device. U.S. Pat. No. 6,220,357 discloses a similar apparatus.
[0007] U.S. Pat. No. 5,609,204 and U.S. Pat. No. 5,579,844 disclose an apparatus having sliding sleeves inside sand control screens in combination with components for supporting gravel packing operations such as polished bore receptacles and port closure sleeves.
[0008] U.S. Pat. No. 5,865,251 discloses an isolation valve “adjacent” or “interior” of the screen assembly which covers the apertures of the valve.
[0009] U.S. Pat. No. 6,405,800 discloses an isolation valve that is positioned in the screen base pipe underneath the screen jacket.
[0010] U.S. Pat. No. 6,343,651 and U.S. Pat. No. 6,446,729 disclose a flow control valve that is coupled to a screen assembly. It is not surrounded by and is offset from the screen wrapping. The valve is in fact not integral to the screen assembly but an added component which is hydraulically coupled to the screen and base pipe annulus to control flow into the main bore.
[0011] U.S. Pat. No. 6,464,006 discloses an apparatus having flow screens with flow closure members. The figures presented in U.S. Pat. No. 6,464,006 illustrate a three-way sub system, but both ends of the isolation pipe are shown affixed to the screen assembly.
[0012] U.S. Pat. No. 6,719,051 and U.S. Pat. No. 7,096,945 disclose a screen assembly with openings in the base pipe and a valve associated with the openings in the base pipe to control flow through the openings.
[0013] U.S. Publication No. 2007/0084605 discloses a screen assembly with at least one production screen valve.
[0014] There is still a need for improved flow control devices that provide incremental choking of the flow and that may be used in sand control completion equipment. There is also a need for a coupling tool that supports a flowpath between two screens without the use of an isolation string.
SUMMARY
[0015] An apparatus including a pipe coupling and integrated valve and method of using the same is disclosed. The apparatus can include a first outer tubular member and a first inner tubular member. The first outer tubular member and the first inner tubular member can define a first space therebetween. The first inner tubular member can have a first internal bore. The system can also include a second outer tubular member and a second inner tubular member. The second outer tubular member and the second inner tubular member can define a second space therebetween. The second inner tubular member can have a second internal bore formed therethrough. A first coupling flowpath can be positioned between the first and second spaces. A second coupling flowpath can be positioned between the first and second internal bores. A selectively closeable flowpath can be positioned between the first coupling flowpath and the second coupling flowpath.
[0016] One or more embodiments of the method of using the multi-zone gravel pack system with pipe coupling an integrated valve can include conveying a completion string downhole. An annulus can be formed between the completion string and a wellbore. The completion string can include at least two sand completion systems, a communication port positioned adjacent to each sand completion system, and a position indicator positioned adjacent to each communication port. Each sand completion system can include one or more apparatuses. The method can further include, positioning one of the sand completion systems adjacent to a lower hydrocarbon bearing zone, and the other sand completion system adjacent to an upper hydrocarbon bearing zone. Communication between the annulus adjacent the upper hydrocarbon bearing zone and the internal bores of the adjacent sand completion system can be prevented, and communication between the annulus adjacent the lower hydrocarbon bearing zone and the internal bores of the adjacent sand completion system can be allowed. Gravel can be provided to a portion of the annulus adjacent to the lower hydrocarbon bearing zone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] So that the recited features can be understood in detail, a more particular description, briefly summarized above, may be had by reference to one or more embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0018] FIG. 1 depicts an illustrative sand completion system in a closed position, according to one or more embodiments described.
[0019] FIG. 2 depicts the illustrative sand completion system of FIG. 1 in an open position, according to one or more embodiments described.
[0020] FIG. 3 depicts an illustrative coupling tool, according to one or more embodiments described.
[0021] FIG. 4 depicts an illustrative view of one or more sand completion systems integrated into a completion string, according to one or more embodiments described.
[0022] FIG. 5 depicts an illustrative service string for performing multi-zone gravel pack operations, according to one or more embodiments described.
[0023] FIGS. 6-12 are schematics of the completion string of FIG. 3 , and depict a sequential illustration thereof configured to perform a gravel pack operation on a wellbore, according to one or more embodiments described.
DETAILED DESCRIPTION
[0024] A detailed description of the one or more embodiments, briefly summarized above, is provided below. As used herein, the terms “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; “upstream” and “downstream”; and other like terms are merely used for convenience to describe spatial orientations or spatial relationships relative to one another in a vertical wellbore. However, when applied to equipment and methods for use in deviated or horizontal wellbores, it is understood to those of ordinary skill in the art that such terms are intended to refer to a left to right, right to left, or other spatial relationship as appropriate.
[0025] FIG. 1 depicts an illustrative sand completion system 100 in a closed position, according to one or more embodiments. The sand completion system 100 can include two or more screen assemblies 110 , 112 having a coupling tool 119 disposed therebetween. Each screen assembly 110 , 112 can include an outer tubular member 106 , 108 disposed about a body or mandrel (“inner tubular member”) 102 , 104 . For example the first assembly 110 can be the first outer tubular member 106 about the first inner tubular member 102 , and the second assembly 112 can include the second outer tubular member 108 about the second inner tubular member 104 .
[0026] The outer tubular members 106 , 108 can include a screen or particulate restricting member. The screen or particulate restricting member can be wire wrapped screens or any other known screen. For example, one or more portions of the outer tubular member can be constituted by wire wrap screen.
[0027] Each inner tubular member 102 , 104 can be base pipe, production tubing, or any other common downhole tubular member. In one or more embodiments, the body 102 (“first inner tubular member 102 ”) can have an inner flowpath or internal bore 126 formed therethrough, and the second body 104 (“second inner tubular member 104 ”) can have an inner flowpath or internal bore 128 formed therethrough.
[0028] A space or gap 114 , 116 is formed between an outer diameter of each inner tubular member 102 , 104 and the surrounding screen 106 , 108 . Each space or gap 114 , 116 defines an outer flowpath about its respective inner tubular member 102 , 104 . For example, a first flowpath or first space 114 is formed between the first inner tubular member 102 and the first screen 106 . The second flowpath or second space 116 is formed between the second inner tubular member 104 and the second screen 108 .
[0029] The coupling tool 119 can include a first coupling flowpath 118 , a second coupling flowpath 120 , and a third coupling flowpath 122 formed therethrough. The first coupling flowpath 118 can be in fluid communication, and thus “couple” the first flowpath or space 114 to the second flowpath or space 116 . The second coupling flowpath 120 can be in fluid communication, and thus “couple” the first inner flowpath 126 to the second inner flowpath 128 . The third coupling flowpath 122 can be in fluid communication, and thus “couple” the first coupling flowpath 118 and the second coupling flowpath 120 .
[0030] The coupling tool 119 can further include a flow control device 124 . The flow control device 124 allows the outer flowpaths 114 , 116 to be selectively communicated with the inner flowpaths 126 , 128 . In one or more embodiment, the flow control device 124 can be integrated into the coupling tool 119 . In one or more embodiments, the flow control device 124 can be a stand alone component that can be attached to the coupling tool 119 .
[0031] In one or more embodiments, the flow control device 124 can be a sliding sleeve. An illustrative sliding sleeve can simply be a tubular member disposed within the annulus of the coupling tool 119 . In one or more embodiments, the flow control device 124 can be a sliding sleeve having one or more apertures or holes formed therethrough. In one or more embodiments, the flow control device 124 can be a remotely operated valve, or any other downhole flow control device. An illustrative flow control device 124 is described in U.S. Pat. No. 6,446,729.
[0032] The use of the flow control device 124 with the coupling tool 119 can allow for flexibility in the design of the flow control device 124 without affecting the manufacturing and design of the sand screen assemblies 110 , 112 . Furthermore, by allowing the complexity of the flow control device 124 to be varied independent of the design of the sand screen assemblies 110 , 112 , various levels of modularity for the sand completion system 100 can be obtained.
[0033] When the flow control device 124 is in a closed position, the first coupling flowpath 118 is not in communication with the second coupling flowpath 120 ; however, the first flowpath or space 114 is in communication with the second flowpath or space 116 , and the first inner flowpath 126 is in communication with the second inner flowpath 128 . Furthermore, the flowpaths 114 , 116 , 118 can be in communication with the exterior of the screen assemblies 110 , 112 . However, the flowpaths 126 , 128 , 120 are prevented from communicating with the exterior of the sand screen assemblies 110 , 112 .
[0034] In the open position, the first coupling flowpath 118 is in communication with the second coupling flowpath 120 , and the third coupling flowpath 122 , as depicted in FIG. 2 . When the flow control device 124 is in an open position, each of the flowpaths 114 , 116 , 126 , 128 , 118 , 122 , 120 is in communication with the exterior of the screen assemblies 110 , 112 . Therefore, the inner flowpaths 126 , 128 are in communication with the exterior of the sand screen assemblies 110 , 112 when the second coupling flowpath 120 is in communication with the first coupling flowpath 118 .
[0035] FIG. 3 depicts an illustrative coupling tool 119 , according to one or more embodiments. The coupling tool 119 can include one or more housings 310 , one or more shrouds 360 , one or more flow control device 124 , one or more first coupling flowpaths 118 , one or more second coupling flowpaths 120 , one or more pipe couplings 320 , one or more torque transfer shrouds (two are shown 330 , 332 ), one or more load inserts 340 , one or more end rings (two are shown 350 , 352 ), one or more pipe joints (two are shown 370 , 372 ), and one or more third coupling flowpaths 122 .
[0036] The length of the coupling tool 119 can be determined by the size of the flow control device 124 . The shroud 360 can be placed at least partially about the housing 310 , and pipe joints 370 , 372 . The first coupling flowpath 118 can be formed between the shroud 360 and the housing 310 and pipe joints 370 , 372 . In one or more embodiments, the shroud 360 can be a solid tubular shroud. The end rings 350 , 352 can be positioned adjacent to the shroud 360 . Since the length of the coupling tool 119 can be determined by the length of the flow control device 124 , a solid shroud would create a section of a sand completion system 100 , without screens that may be longer than encountered in typical applications. This could have an adverse effect on the placement of the sand control treatment. Such effects can be poor packing around the coupling area and premature bridging at the top of the coupling area. In this situation, the shroud can include slotted openings (not shown). For example, a slotted liner can be used. The slotted liner can allow for leak off during gravel placement. Therefore, in one or more embodiments, the entire shroud or a portion of the shroud can include the slotted openings.
[0037] The flow control device 124 can be disposed within the housing 310 . The housing 310 can be positioned between the pipe joints 370 , 372 . The housing can have a plurality of apertures 311 or holes formed therethrough. The apertures 311 can allow communication between the second coupling flowpath 120 and the third coupling flowpath 122 . The apertures or holes can be selectively opened and closed by the flow control device 124 . For example, if the flow control device 124 is a sliding sleeve the sliding sleeve can be configured to selectively prevent flow through the apertures 311 , thus preventing communication between the third coupling flowpath 122 and the second coupling flowpath 120 .
[0038] The pipe joints can be tubular members configured to attach or otherwise engage inner tubular members of a double wall tubular assembly, such as screen assemblies 110 , 112 . A pipe coupling 320 can be positioned adjacent to at least one of the pipe joints 370 , 372 , such as “upper” pipe joint 370 , as depicted in FIG. 3 .
[0039] The torque shrouds 330 , 332 can be positioned about a portion of the pipe joint 370 , 372 , and the pipe coupling 320 . The torque shrouds can be production tubing or other known downhole tubing. The torque shrouds 330 , 332 can allow for the transfer of torque. The “upper” torque shroud 330 can be floating allowing the “upper” torque shroud 330 to move. The “lower” torque shroud 332 can be fixed to the pipe joint 372 .
[0040] A load insert 340 can be positioned adjacent to the “upper” torque shroud 330 . The load insert 340 can interface with a screen table/plate known in the industry and temporarily support the hanging weight of the completion during make up operations at surface.
[0041] FIG. 4 depicts an illustrative view of one or more sand completion systems 100 integrated into a completion string 400 , according to one or more embodiments. The completion string 400 can include two or more sand completion systems 100 (two are shown), two or more isolation packers (two are shown 406 , 408 ), one or more internal upsets 420 , two or more port closure sleeves (two are shown 430 , 432 ), and two or more position indicators (two are shown 440 , 442 ). The completion string 400 can include any type of well treatment strings, including well treatment strings that are used during subterranean formation fracturing, completion, or other operations. A suitable completion string 400 can be used for gravel packing operations, chemical treatment operations, and/or other common workover operations.
[0042] The isolation packers can be used to isolate hydrocarbon bearing zones (not shown) located within a producing formation (not shown). For example, the first isolation packer can be disposed adjacent to an upper hydrocarbon bearing zone, the second isolation packer can be disposed adjacent to a lower hydrocarbon bearing zone, and a third isolation packer (not shown) can be disposed below the lower hydrocarbon bearing zone. In one or more embodiments, the third packer can be installed in a wellbore (not shown) prior to the installation of the completion 400 and the completion 400 can be configured to attach to or otherwise engage the third isolation packer, or in the alternative the isolation packer can be integrated with the completion 400 . The isolation packers 406 , 408 can be compression or cup packers, inflatable packers, “control line bypass” packers, polished bore retrievable packers, any other common downhole sealing mechanism, or combinations thereof. The isolation packers 406 , 408 can be set in the wellbore by the use of mechanical means or by any other known method.
[0043] The internal upset 420 can be disposed adjacent to the second packer 408 . The internal upset 420 can allow for a more direct reverse flow. The internal upset 420 can be an internal upset commonly known in the art.
[0044] The first port closure sleeve 430 can be disposed adjacent to the first packer 406 . The second port closure sleeve 432 can be disposed adjacent to the internal upset 420 . The port closure sleeves can be engaged by a service tool (not shown), and can allow the service tool to communicate with the exterior of the completion 400 . The port closure sleeves 430 , 432 can be any port closure sleeve commonly known in the art. An illustrative communication port closure sleeve is described in more detail in U.S. Pat. No. 7,066,264. The port closure sleeves 430 , 432 can have polished bore receptacles (not shown).
[0045] The position indicators 440 , 442 can be disposed adjacent to the port closure sleeves 430 , 432 . The position indicators 440 , 442 can be used to position a service tool for engagement with the port closure sleeves 430 , 432 . Each position indicators 440 , 442 can be a “Go/no go” collar, for example. A suitable indicator is described in U.S. Pat. No. 7,066,264. Of course, the position indicators 440 , 442 can be any other type of position indicator known in the art.
[0046] Additional coupling tools 119 can be positioned at each end of each sand completion system 100 . In one or more embodiments, one or more of the coupling tools 119 of one or more of the sand completion systems 100 can be modified by removing the third coupling flowpath 122 , and the flow control device 124 . Such modified coupling tool (not shown) could provide the first coupling flowpath 118 and the second coupling flowpath 120 . However, the first coupling flowpath 118 would not be in communication with the second coupling flowpath 120 . In one or more embodiments, such modified coupling tool could be used as a contingency perforating target. For example, a perforating gun can be run into the wellbore, located adjacent the modified coupling tool and perforate holes into the modified coupling tool to allow for communication between the completion bore and the annulus.
[0047] FIG. 5 depicts a service string 500 for performing multi-zone gravel pack operations, according to one or more embodiments. The service string 500 can include one or more tubular members 510 , one or more gravel pack setting modules 520 , one or more spacer strings 530 , one or more cross over port bodies 540 , one or more reversing valves 560 , one or more shifting tools 580 , and one or more sliding sleeve collets 590 .
[0048] The tubular member 510 can be production tubing or other tubing commonly used downhole. The tubular member 510 can have a length sufficient to run from the surface down to the top of the completion 400 .
[0049] The gravel pack setting module 520 can be engaged or otherwise supported by the tubular member 510 . The gravel pack setting module 520 can be any gravel pack setting module known in the art. The gravel pack setting module 520 can be configured to engage or otherwise attach to the first packer 406 . The gravel pack setting module 520 can be used to set the top isolation packer, such as first packer 406 .
[0050] The spacer string 530 can be positioned adjacent to the packer setting module 520 . The spacer string 530 can be a blank pipe or other tubing member. The spacer string 530 can have a length long enough to extend the shifting tool 580 bellow the lowermost flow control device 124 to be operated. For example, the spacer string 530 can be long enough to extend the shifting tool 580 below the flow control device 124 of the lowermost coupling tool 119 of a “lower” sand completion system 100 .
[0051] The cross over port body 540 can be disposed on the spacer string 530 above the shifting tool 580 . The cross over port body 540 can be any cross over port body known in the art. In one or more embodiments, the cross over port body 540 can be equipped with a shear down ball seat 542 . The crossover port body 540 can sealably interface with the completion bore 405 at various locations to support multi-zone gravel pack operations. The sealable interface can be achieved using methods commonly known in the art. For example, the sealable interaction can either be by seals (not shown), such as bonded seals or cup seals, on the outer diameter of the cross over port body 540 and polished bore receptacles (not shown) integrated into the completion or the inverse using internal seals (not shown) integrated with the completion 400 and polished surfaces (not shown) on the outer diameter of the cross over port body 540 .
[0052] The reversing valve 560 can be positioned below the crossover port body 540 . The reversing valve 560 can restrict or prevent flow downhole past the service string 500 . In one or more embodiments, it would be desirable that the reversing valve 560 operate without impairing movements of the service tool 500 , due to hydraulic locking issues. One way to provide such functionality is to use a full bore set down module or equivalent technology with a modified valve that has a small hole through it to allow for minimal leak through while supporting greater reverse out pressures/rates. In one or more embodiments, the reversing valve 560 can have an anti-swab feature. The reversing valve 560 can be any valve known in the art.
[0053] The shifting tool 580 can be positioned below the reversing valve 560 . The shifting tool 580 can be adapted to at least actuate the flow control devices 124 of the sand completion assemblies 100 . In one or more embodiments, the shifting tool 580 can actuate the flow control devices 124 and the port closure sleeves 430 , 432 . The shifting tool 580 can be a collet, a magnetic actuator, another common down hole shifting tool, or combinations thereof.
[0054] The sliding sleeve shifting tool 590 can be disposed below the shifting tool 580 . The sliding sleeve shifting tool 590 can be configured to actuate at least the port closure sleeves 430 , 432 . In one or more embodiments, the sliding sleeve shifting tool 590 can be configured to open the flow control device 124 and the port closure sleeves 430 , 432 . In one or more embodiments, the sliding sleeve shifting tool 590 can be a collet, a magnetic actuator, another common down hole shifting tool, or combinations thereof. The interaction of the service string 500 and the completion string 400 is described in more detail in FIGS. 6-12 .
[0055] FIG. 6 depicts an embodiment of the completion string 400 configured to perform a gravel pack operation on a wellbore 600 , according to one or more embodiments. The service string 500 can be positioned within the completion bore 405 of the completion string 400 . When used with cased holes, perforating steps can be taken before the completion string 400 is run-in the wellbore 600 , and the sump packer 603 can be set. In one or more embodiments, the perforation steps, the setting of the sump packer 603 , and the placement of the completion string 400 into the wellbore can be performed in the same trip.
[0056] To run-in the completion string 400 the gravel pack setting module 520 can be secured or otherwise engaged with the first isolation packer 406 , and the “upper” sand completion system 100 can be placed adjacent to hydrocarbon bearing zone 605 , and the “lower” sand completion system 100 can be placed adjacent to the hydrocarbon bearing zone 610 . The spacing of the sand completion systems 100 can be determined by logging information or other downhole measurements. An annulus 620 can be formed between the completion string 400 and the wall 602 of the borehole 600 . Upon positioning of the sand completion systems 100 , the first packer 406 can be set and the packer module 520 can be released from the first packer 406 , as depicted in FIG. 6 . As depicted in FIG. 7 , the rest of the packers, such as second packer 408 can be set and possible tested. Of course, in one or more embodiments, each packer 406 , 408 can be set before the packer module 520 is released from the first packer 406 . In one or more embodiments, one or more packers can be tested before the packer module 520 is released from the first packer 406 .
[0057] Turning now to FIG. 8 , the service string 500 can be used to open at least the lower most flow control device 124 of the “lower” sand completion system 100 , and the second port closure sleeve 432 . The service string 500 can then be positioned to place gravel slurry 630 into the annulus 620 adjacent to the “lower” sand completion system 100 . When the gravel slurry 630 is placed in the annulus 620 , it is driven within the portion of the annulus 620 adjacent to the second hydrocarbon bearing zone 610 , and dehydrates. As the gravel slurry 630 dehydrates a fluid portion 632 , such as clean carrier fluid, can migrate through the first screen assembly 110 and the second screen assembly 112 of the “lower” sand completion system 100 , and gravel 364 from the gravel slurry 630 can be held within the annulus 620 by the sand screen assemblies 110 , 112 of the “lower” sand completion system 100 . The fluid portion 632 can migrate flow thorough the flowpaths 114 , 116 , 118 of the “lower” sand completion system 100 , and can flow through the opened flow control devices 124 into the completion bore 405 adjacent to the “lower” hydrocarbon bearing zone 610 . The fluid 505 can travel uphole as depicted in FIG. 8 . After the gravel 634 has formed a tight pack in the annulus 620 , the placing of gravel slurry 630 can be stopped. The excess gravel slurry 900 can then be reversed out to the surface, as depicted in FIG. 9 . After the excess slurry 900 is reversed out the service string 500 can close opened flow control devices 124 of the “lower” sand completion system 100 and the second port closure sleeve 432 , thereby, isolating the “lower” hydrocarbon bearing zone 610 .
[0058] As depicted in FIG. 10 , the service string 500 can actuate or “open” at least the lower flow control device 124 of the “upper” sand completion system 100 and the first port closure sleeve 430 . Then the service string can be aligned with the port closure sleeve 430 using the position indicator 440 . Gravel Slurry 630 can be pumped into the annulus 620 adjacent the “upper” hydrocarbon bearing zone 605 . The gravel slurry can gather in the annulus 620 . As the gravel slurry 620 dehydrates the fluid portion 632 can migrate through the sand screen assemblies 110 , 112 and the flowpaths 114 , 116 , 118 of the “upper” sand completion system 100 , and can flow through the opened flow control devices 124 into the completion bore 405 adjacent to the “upper” hydrocarbon bearing zone 605 . The fluid portion 632 can travel uphole as depicted in FIG. 10 , and the gravel 634 is held in place by the screen assemblies 110 , 112 . After the gravel pack is formed in the annulus 620 adjacent the “upper” hydrocarbon bearing zone 605 , the excess slurry 900 can be reversed out as depicted in FIG. 11 . After the reverse out operation the opened flow control devices 124 and the first port closure sleeve 430 can be closed completely isolating the annulus 620 adjacent to each hydrocarbon bearing zone 605 , 610 , and the service tool 500 can be removed, as depicted in FIG. 12 . The above described actions can be performed for each hydrocarbon bearing zone intersected by the wellbore 600 .
[0059] In one or more embodiments, when the upper completion is landed and the surface installations are ready for production, the flow control devices 124 can be selectively opened using slickline, wireline, coil tubing, or another conventional method to provide access to the hydrocarbon bearing zones 605 , 610 . In one or more embodiments, mechanical or magnetic interaction can be used to open the flow control devices 124 .
[0060] In one or more embodiments, the flow control device 124 can be operated remotely. For example, pressure or a control conduit disposed adjacent to the completion 400 can be used to operate the flow control devices 124 . The flow control devices 124 can also be operated remotely during the gravel pack operation as described in U.S. Pat. No. 6,446,729.
[0061] The present completion string and methods may be practiced in combination with one or more sets of components and/or service tools, including bridge plugs, flow valves, and other commonly used oil field tools. The term “attached” refers to both direct attachment and indirect attachment, such as when one or more tubulars or other downhole components are disposed between the “attached” components.
[0062] Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges from any lower limit to any upper limit are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values are “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.
[0063] Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.
[0064] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | Apparatus having a first outer tubular member and a first inner tubular member. The first outer tubular member and the first inner tubular member can define a first space therebetween. The first inner tubular member can have a first internal bore. The apparatus can further include a second outer tubular member and a second inner tubular member. The second outer tubular member and the second inner tubular member can define a second space therebetween. The second inner tubular member can have a second internal bore. A first coupling flowpath can be positioned between the first and second spaces. A second coupling flowpath can be positioned between the first and second internal bores. A selectively closeable flowpath can be positioned between the first coupling flowpath and the second coupling flowpath. | 4 |
FIELD
[0001] The present invention relates to a field of capacitive touch panels. More specifically, the present invention relates to capacitive touch panels that comprise complementary upper and lower electrode patterns.
BACKGROUND
[0002] Nowadays, conventional capacitive touch panels detect changes of the capacitance to sense human contact and are generally consisting of capacitor array and capacitor sensing-reading circuits. Besides, the capacitor array is the capacitor formed by the upper layer wire pattern and the lower layer wire pattern, and different capacitances are generated by different design patterns. Also, the upper layer and the lower layer of the conventional capacitive touch panels are usually designed by opposite pattern. However, though the upper and lower layer designed by opposite patterns increase the sensitivity of the vertical capacitive detecting, the planar capacitive detecting is worse. In addition, if the touch panel utilizes indium tin oxide (ITO) as wires, the resistance will increase in proportion to the panel size. Moreover, the opposite patterns of the upper and lower electrode are used for optimizing the sensitivity, so the sensitivity will decrease dramatically if the front side and reverse side of the touch panel are changed.
[0003] The US patent application US200710062739 discloses an electrode pattern adopted general dual layer design, and the upper and lower layers thereof are designed to have the same direction. Due to the structure thereof, the capacitance change can be measured only on a single surface and can not be detected while bending. Moreover, the capacitances interfere with each other so as to decrease the sensitivity of the detection. On the other hand, the US patent application 2007/0229470 only provides a method for bending the capacitive touch sensor; also, the sensitivity of the structure and design method thereof can not have the maximum efficiency and are not able to adjust the sensitivity of the touch panel by the bending levels.
[0004] “A Pixel-level Automatic Calibration Circuit Scheme,” presented by Morimura et al., discloses integrating the touch capacitive sensor on pixels to measure the fingerprint. The sensing circuit must be disposed under the capacitor and without the bending effect. On the other hand, “Method for Testing Electrostatic Discharge Tolerance for Fingerprint Sensor LSI,” presented by Yasuyuki et al., discloses a design and manufacture method that utilize touch control panel to identify fingerprint The design and manufacture method are lack of bending function and the sensitivity will be decreased.
SUMMARY
[0005] Regarding to the drawbacks of the conventional capacitive touch panel, the object of the present invention is providing a capacitive touch panel that solves the shielding problem in the design of the conventional capacitive touch panel.
[0006] Another object of the present invention is providing a capacitive touch panel comprising a first electrode layer comprising a first pattern, a dielectric layer disposed under the first electrode layer, and a second electrode layer disposed under the dielectric layer and comprising a second pattern. Also, the second pattern and the first pattern are complementary.
[0007] Another object of the present invention is providing a capacitive touch panel comprising a first electrode layer comprising a first pattern, a dielectric layer disposed on the first electrode layer, and a second electrode layer disposed under the dielectric layer and comprising a second pattern. Besides, the second pattern and the first pattern are complementary.
[0008] According to the aforementioned description, the capacitive touch panel in accordance with the present invention has one or more advantages as following:
[0009] (1) The capacitive touch panel can detect the capacitive between rows, columns, and the capacitive between row and column by designing the electrode patterns. Thus, the drawbacks that conventional capacitive touch panel only detects the vertical capacitive can be eliminated.
[0010] (2) The capacitive touch panel can solve the problem that the upper and lower electrodes interferes each other by designing the electrode patterns.
[0011] (3) The capacitive touch panel is able to detect by planar capacitor, therefore, the detection can be made rapidly because of the planar capacitor.
[0012] (4) The capacitive touch panel can solve the power consumption problem of the product through controlling the capacitive touch panel adequately without sacrificing the touch detection functionality.
[0013] With these and other objects, advantages, and features of the invention that may become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the detailed description of the invention, the embodiments and to the several drawings herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The exemplary embodiments of the present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.
[0015] FIG. 1 illustrates the sectional view of a touch capacitive panel in accordance with the present invention;
[0016] FIG. 2 illustrates the schematic view of the first electrode layer in accordance with the present invention;
[0017] FIG. 3 illustrates the schematic view of the second electrode layer in accordance with the present invention;
[0018] FIG. 4 illustrates the schematic view of the first embodiment in accordance with the present invention;
[0019] FIGS. 5 illustrates the schematic view of the second embodiment in accordance with the present invention;
[0020] FIG. 6 illustrates the schematic view of the third embodiment in accordance with the present invention;
[0021] FIG. 7 illustrates the schematic view of the fourth embodiment in accordance with the present invention;
[0022] FIG. 8 illustrates the schematic view of the fifth embodiment in accordance with the present invention; and
[0023] FIG. 9 illustrates the schematic view of the sixth embodiment in accordance with the present invention.
DETAILED DESCRIPTION
[0024] Exemplary embodiments of the present invention are described herein in the context of an orthodontic appliance. The invention and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments. Those of ordinary skilled in the art will realize that the following detailed description of the exemplary embodiments is illustrative only and is not intended to be in any way limiting. Reference will now be made in detail to implementations of the exemplary embodiments as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts.
[0025] Please refer to FIG. 1 , which is the sectional view of a touch capacitive panel in accordance with the present invention. As shown, the capacitive touch panel 1 comprises a first electrode layer 10 , a dielectric layer 11 , a second electrode layer 12 , and a protective layer 13 . Besides, the first electrode layer 10 comprises a first pattern 100 (as shown in FIG. 2 ), the dielectric layer 11 is disposed under the first electrode layer 10 , and the second electrode layer 12 is disposed under the dielectric layer 11 and comprises a second pattern 120 (as shown in FIG. 3 ). Moreover, the second pattern 120 is complementary to the first pattern 100 , each pattern is in the form of rows or columns, and each row and each column are continuous. The protective layer is disposed on the first electrode layer 10 and separates the first electrode layer 10 from outer environment to protect and achieve the scratch free goal.
[0026] The dielectric layer 11 between the upper and lower electrodes is subject to form a capacitor thereon. Moreover, the first electrode layer, the second electrode layer, the dielectric layer, and the protective layer are transparent. Furthermore, the first electrode layer and the second electrode layer are made of indium tin oxide (ITO).
[0027] On the other hand, the sequence of the layers in accordance with the present invention may be counted from the bottom as: the first electrode layer 10 , the dielectric layer 11 , the second electrode layer 12 , and the protective layer 13 .
[0028] Please refer to FIG. 2 and FIG. 3 , which are the schematic view of the first and the second electrode layer in accordance with the present invention respectively. As shown in FIG. 2 , the first electrode layer 10 comprises a first pattern 100 ; each column therein consisting of a plurality of continuous semicircle arcs, and the arcs are suitable for the finger touching shape. Referring to FIG. 3 for the second pattern 120 in the second electrode layer 12 . Each row of the second pattern 120 comprises a plurality of serially connecting bullet shapes. In addition, the first electrode and the second electrode are complementary, so the sensitivity of the detection can be optimized. Besides, because the first electrode and the second electrode are not shielded, the sensitivity of the capacitor detection between the rows or between the columns can be optimized.
[0029] Please refer to FIG. 4 , which is the schematic view of the first embodiment in accordance with the present invention. As shown, the pattern in the rows of the lower electrode layer (the second pattern 120 ) is not completely shielded by the pattern in the columns of the upper electrode layer (the first pattern 100 ), the lower electrode layer thus can process the row detection without influence of the upper electrode layer. Besides, the sectional view of the AA line is shown in FIG. 1 .
[0030] Please refer to FIG. 5 , which is the schematic view of the second embodiment in accordance with the present invention. As shown, the difference between the second embodiment and the first embodiment is that the first pattern 100 is a plurality of rectangles bridging each other, and the second pattern 120 is a plurality of S shapes connecting to each other.
[0031] Please refer to FIG. 6 , which is the schematic view of the third embodiment in accordance with the present invention. As shown, the difference between the third embodiment and the first embodiment is that the first pattern 100 is a plurality of rectangles bridging each other, the second pattern 120 is formed as grooves, and a portion of each of the rectangles in the first pattern 100 is surrounded by the second pattern 120 .
[0032] Please refer to FIG. 7 , which is the schematic view of the fourth embodiment in accordance with the present invention. As shown, the difference between the fourth embodiment and the first embodiment is that the first pattern 100 is a plurality of rectangles bridging each other, and the second pattern 120 is a plurality of M shapes connecting to each other.
[0033] Please refer to FIG. 8 , which is the schematic view of the fifth embodiment in accordance with the present invention. As shown, the difference between the fifth embodiment and the first embodiment is that the first pattern 100 is a plurality of rectangles bridging each other, the second pattern 120 is formed as grooves, and each of the rectangles in the first pattern 100 is completely surrounded by the second pattern 120 .
[0034] Please refer to FIG. 9 , which is the schematic view of the sixth embodiment in accordance with the present invention. As shown, the difference between the sixth embodiment and the first embodiment is that the first pattern 100 is a plurality of arrow shapes comprising arrowhead portion 1000 and shaft portion 1001 , the second pattern 120 is a plurality of Z shapes, and concave portions of the second pattern 120 completely surround the arrowhead portion 1000 of the first pattern 100 .
[0035] The capacitive touch panel utilizes the capacitor and electrode design patterns that are different from the prior art, and the structure and control rule can achieve the goal of consumption extreme low power.
[0036] While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are intended to encompass within their scope of all such changes and modifications as are within the true spirit and scope of the exemplary embodiments of the present invention. | The present invention discloses a capacitive touch panel comparing a first electrode layer, a dielectric layer and a second electrode layer. The first electrode layer has a first pattern. Also, the dielectric layer is disposed under the first electronic layer with a second pattern. Moreover, the first pattern and the second pattern are complementary. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No. PCT/EP00/06890, filed Jul. 19, 2000, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention is directed to an apparatus for holding and dispensing metered amounts of at least one active composition into a washing machine, a laundry dryer or a dishwashing machine.
U.S. Pat. No. 4,379,515 discloses a dispensing device for detergent, comprising a rigid container and, communicating with this rigid container by means of a pipe, a compressible reservoir containing the measured quantity of detergent needed for one washing cycle. Under the effect of centrifugal forces generated by rotation of the laundry drum, the reservoir is compressed—particularly if it is disposed between the laundry and the wall of the laundry drum—in such a way that its contents are emptied into the rigid container, where the detergent is then dissolved by the washing liquid. A disadvantage of this dispensing system resides in the fact that the reservoir can be used for only one respective washing cycle and has to be replaced with each new washing cycle.
European patent publication EP 0 215 366 describes a detergent container with a welded seal, wherein the welded seal melts at a specific operating temperature and then releases the detergent. The seal of the container in particular cannot be used again, and in addition it is not possible to dispense more than once with this system.
European patent publication EP 0 328 769 describes a removable dispensing container with a closure that can be opened during a washing cycle and which has a manipulating extension. The pressure exerted by the laundry during the washing cycle causes the manipulating extension to be pushed into the dispensing container in such a way that the detergent is able to flow out. It is not possible to dispense more than one dose and the dispensing container must be filled again before each washing cycle.
German patent publication DE 39 02 356 discloses a dispensing container which may be used for a single washing cycle only and operates on the basis of a temperature-dependent release of a liquid fabric conditioner. The rising temperature causes the pressure in the dispensing container to rise above atmospheric pressure, as a result of which a gate valve is displaced into its open position, permitting the liquid fabric conditioner to flow into the washing machine.
U.S. Pat. No. 5,033,643 describes a dispensing container, which also allows a metering unit to be released for only one washing cycle. Forces generated by the wet laundry act on the release mechanism of the dispensing container.
German patent publications DE 39 34 123 and DE 39 22 342 describe detergent containers which are fixedly mounted on the laundry drum. Pins or locking hooks are used for fixing purposes. With these containers, no provision is made for more than one dose, which means that they have to be removed from the washing machine after every washing cycle and re-filled.
U.S. Pat. No. 5,176,297 describes a dispensing system for a dishwashing machine, which is mounted in the interior of the machine and incorporates a supply and a dispensing compartment. Although it is possible to dispense more than one dose, the dispensing system is controlled by the dishwashing machine in a complex manner.
German patent publication DE 195 40 608 discloses a system enabling more than one dose to be dispensed, in which tablets of dishwashing detergent are placed. The individual doses are controlled by a command issued by the dishwashing machine, i.e., an operating program of the dishwashing machine selected by the user controls the time at which the dose is released.
Australian published patent application AU-A-78393/91 discloses a dispensing container for a detergent, which is dispensed through an orifice opened by the build-up of internal pressure in the container. This internal pressure is generated either by the operating program of the machine or by operation directly on the part of the user.
Summing up the state of the art, dispensing systems are known which primarily permit individual doses to be dispensed and in a few cases multiple doses. In systems permitting a single dose, the release of detergent is generally operated on the basis of a delayed release, which may be triggered by means of a rise in temperature, an increase in pressure or centrifugal forces, for example. What systems permitting multiple doses have in common is that the release is mechanically triggered (valve, piston, gate, etc.) either on the basis of a command issued by the washing program of the machine or by direct operation on the part of the user.
BRIEF SUMMARY OF THE INVENTION
An underlying objective of the invention is to propose an apparatus for holding and dispensing metered doses of an active composition into a laundry washing machine, a dryer or a dishwashing machine, which enables more than one dose to be dispensed (in either one or more washing, drying or dishwashing rinse cycles) and is triggered independently of the commands of an operating program in the machine or intervention by the user.
This objective is achieved by the invention using an apparatus of the generic type having a supply chamber for containing at least double the quantity of an individual dose of the active composition. Connected to the supply chamber by a passage is a dispensing chamber for containing a single dose of the active composition and releasing the same via a discharge passage into the interior of the machine. Means are provided for opening the discharge passage and closing, beforehand or simultaneously, the passage between the supply chamber and dispensing chamber. The opening means are operated by means that are activated by conditions prevailing in the interior of the machine, which occur exclusively during a washing, drying or dishwashing cycle. Means are also provided for re-opening the passage between the supply chamber and the dispensing chamber and closing, beforehand or simultaneously, the discharge passage of the dispensing chamber in order to refill the same from the supply chamber.
In a first embodiment the apparatus proposed by the invention comprises a fluid reservoir; an expansion mechanism and a one-way valve disposed between the fluid reservoir and the expansion mechanism, so that fluid is able to flow between the fluid reservoir and the expansion mechanism. An opening/closing mechanism is operated by the expansion mechanism, in such a way that the discharge passage of the dispensing chamber is opened and the passage between the supply chamber and the dispensing chamber is closed, beforehand or simultaneously, to enable the contents of the dispensing chamber to be substantially entirely released into the machine. A return mechanism re-positions the opening/closing mechanism in the initial position; and means are provided to enable the hydraulic fluid to leave the expansion mechanism when the opening/closing mechanism is re-set by the return mechanism.
Accordingly, the flow of fluid from the fluid reservoir into the expansion mechanism is operated either by the wet laundry or dry laundry compressing the fluid reservoir directly or indirectly, in which case the opening/closing mechanism is preferably a gate valve, or by a pivotably mounted weight exerting pressure on the fluid reservoir due to the rotation of the apparatus with the washing machine or dryer drum, in which case the opening/closing mechanism is preferably a float valve. In both cases the return mechanism is preferably a return spring.
In another embodiment, the apparatus proposed by the invention comprises a one-way valve between the supply chamber and the dispensing chamber. A water chamber with a one-way valve is provided so that, at the start of an operating cycle, water disposed in the machine flows through the one-way valve into the water chamber, expanding it to the degree that the dispensing chamber is compressed. A discharge passage of the dispensing chamber is opened and, beforehand or simultaneously, the one-way valve between supply chamber and dispensing chamber is closed to permit the contents of the dispensing chamber to be substantially entirely released into the machine. Means are provided to enable the water slowly to leave the water chamber, causing the dispensing chamber to expand again. As a result, the one-way valve between the supply chamber and the dispensing chamber is opened and, beforehand or simultaneously, the discharge passage of the dispensing chamber is closed to allow the dispensing chamber to be filled from the supply chamber again. The means enabling the water to leave the water chamber preferably comprises small orifices.
In a further embodiment the apparatus proposed by the invention comprises a one-way valve between the supply chamber and the dispensing chamber. Means which alter in form, at least to a certain degree, when the temperature is increased, cause the dispensing chamber to be compressed, the discharge passage of the dispensing chamber to be opened and, beforehand or simultaneously, the one-way valve between supply chamber and dispensing chamber to be closed, to enable the contents of the dispensing chamber to be substantially entirely released into the machine. The means which alter in form undergo a reverse change of form, at least to a certain degree, on cooling, causing the one-way valve between the supply chamber and the dispensing chamber to be opened again and, beforehand or simultaneously, the discharge passage of the dispensing chamber to be closed, in order to refill the dispensing chamber from the supply chamber.
An alternative to this further embodiment of the invention is characterized by a rigid chamber with a material disposed therein, in particular a wax, which expands as the temperature increases and shrinks on cooling. Preferably, the supply chamber is designed so that it contains a wax. This being the case, it is preferable if the opening mechanism is raised by means of a flexible diaphragm, which responds to the expansion of the material.
The apparatus proposed by the invention is additionally characterized by a bimetallic strip, which bends when the temperature increases and returns to shape on cooling.
Particularly preferred, the supply chamber is designed so that it can be re-filled from the exterior.
In one particularly practical arrangement, the apparatus proposed by the invention is firmly but detachably secured in the interior of the machine.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
FIG. 1 is a cross sectional view through a first embodiment of the apparatus proposed by the invention in a non-dispensing state;
FIG. 2 is a view similar to FIG. 1 of the first embodiment of the apparatus illustrated in a dispensing state;
FIG. 3 is a vertical cross sectional view of a second embodiment of the apparatus proposed by the invention in a non-dispensing state;
FIG. 4 is a vertical cross sectional view similar to FIG. 3 showing the apparatus of the second embodiment in a dispensing state;
FIG. 5 is a vertical cross sectional view of a third embodiment of the apparatus proposed by the invention in a non-dispensing state;
FIG. 6 is a vertical cross sectional view similar to FIG. 5 showing the apparatus of the third embodiment in a dispensing state;
FIG. 7 is a vertical cross sectional view of a fourth embodiment of the apparatus proposed by the invention in a non-dispensing state; and
FIG. 8 is a vertical cross sectional view similar to FIG. 7 showing the apparatus of the fourth embodiment in a dispensing state.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts an apparatus based on a hydraulic operating mode. Accordingly, the apparatus comprises a supply chamber 1 , a dispensing chamber 2 and a compressible bladder 3 . The apparatus is triggered by the action of the wet or dry laundry on the compressible bladder 3 , causing the latter to be compressed. A hydraulic fluid 6 (preferably water) disposed therein is discharged through a one-way valve 4 to a bellows 5 . The one-way valve 4 prevents the hydraulic fluid 6 from flowing back into the compressible bladder 3 . The bellows 5 displaces an opening mechanism 7 (e.g., a gate valve) so that the passage 9 between the supply chamber 1 and the dispensing chamber 2 is first closed, after which the passage 8 from the dispensing chamber 2 into the machine is opened for dispensing the active composition.
A return mechanism 11 (e.g., a spring) returns the opening mechanism 7 into its initial position, such that the discharge passage 8 from the dispensing chamber 2 to the machine is closed, and the passage 9 between the dispensing chamber 2 and the supply chamber 1 is opened again. At the same time, the bellows 5 is pushed together again, and the hydraulic fluid 6 is able to flow back, e.g., through a small orifice 10 , into the compressible bladder 3 , which expands to its original size. Because the passage 9 between the supply chamber 1 and the dispensing chamber 2 is open again, the dispensing chamber 2 can now be filled again.
The opening mechanism can be designed so that it is not re-positioned until a machine cycle has been completed, i.e., there will be only one dispensing action into the machine during a cycle. However, it would also be conceivable, e.g., by dimensioning the orifice 10 and the return spring 11 accordingly, for the opening mechanism to be re-set more than once during a cycle, to allow several individual doses to be released during one cycle.
It goes without saying that within the scope of the invention, other embodiments would also be conceivable. For example, it would be conceivable for the opening mechanism to open the discharge passage 8 to the machine and the passage 9 between the supply chamber 1 and the dispensing chamber 4 simultaneously. Similarly, it would also be conceivable for a measured quantity of the active composition to be completely ejected from the dispensing chamber 2 by means of a slight pressure generated by the cover of the apparatus.
A second embodiment of the apparatus proposed by the invention (FIGS. 3 and 4) is of a similar construction, but uses a different principle to operate the opening/closing mechanism. As the apparatus rotates with the washing machine or dryer drum, a pivotably attached weight 30 pushes, as it is displaced, against a compressible chamber 3 ′. As a result, a hydraulic fluid 6 ′ disposed in this chamber 3 ′ is forced through the one-way valve 4 ′ into an expansion chamber 5 ′. As the expansion chamber 5 ′ is gradually filled, the float valve 7 ′ mounted therein rises against the pressure of the return spring 11 ′.
In a non-dispensing state (FIG. 3 ), the float valve 7 ′ closes off the discharge passage 8 between the dispensing chamber 2 and the machine. As the float valve 7 ′ rises, it pivots about the valve, closing off the discharge passage 8 , thereby also closing off the passage 9 between the supply chamber 1 and the dispensing chamber 2 . As the float valve 7 ′ rises still farther (FIG. 4 ), it finally opens the discharge passage 8 so that the dispensing chamber 2 can be emptied into the machine. As the washing machine or dryer drum rotates, the float valve 7 ′ is essentially retained in this upper position.
Once the washing machine or dryer drum stops rotating, the expansion chamber 5 ′ slowly empties via the orifice 10 ′, closing the discharge passage 8 to the machine again and re-opening passage 9 between supply chamber 1 and dispensing chamber 2 , allowing the dispensing chamber 2 to be filled again in readiness for the next cycle.
The apparatus proposed by the invention illustrated in FIGS. 5 and 6 operates on the basis of a back-pressure effect and is primarily suitable for use in a laundry washing machine. The active composition is discharged from a filled supply chamber 12 via a one-way valve 14 into a dispensing chamber 13 disposed underneath the supply chamber 12 . Disposed underneath the dispensing chamber 13 is a water chamber 15 into which water disposed in the machine at the start of an operating cycle flows via a one-way valve 16 and fills the chamber 15 . As the water chamber 15 fills, it causes the one-way valve 14 between the supply chamber 12 and the dispensing chamber 13 to close on the one hand and, on the other hand, compresses the dispensing chamber 13 causing its contents to be released into the washing machine through a discharge passage 17 . Once the operating cycle is completed, the water drains slowly out of the bottom water chamber 15 through small orifices 18 , and the discharge passage 17 of the dispensing chamber 13 is closed. The dispensing chamber 13 is then able to expand, as a result of which the one-way valve 14 can re-open, enabling the dispensing chamber 13 to be filled again with active composition from the supply chamber 12 .
In this third embodiment of the apparatus, it is particularly important for the bottom water chamber 15 to remain completely filled with water during the operating cycle, so that the one-way valve 14 remains closed, in order prevent any additional dispensing action from the supply chamber 12 .
Another embodiment would also be conceivable in which, instead of being arranged one above the other, the three chambers were arranged in a different layout relative to one another. Instead of providing small orifices 18 , it would also be conceivable to use other drainage means (e.g., a semi-permeable membrane) for draining the water from the water chamber 15 .
In a fourth embodiment of the apparatus proposed by the invention, illustrated in FIGS. 7 and 8 and based on a temperature effect, a supply chamber 19 filled with active composition releases the composition via a one-way valve 21 to a dispensing chamber 20 disposed underneath the supply chamber 19 . Underneath the dispensing chamber 20 is a rigid bottom chamber 22 containing a wax 23 . An increase in temperature, i.e., as the water or the dryer interior is heated to the desired operating temperature, causes the wax 23 to expand, pushing a ram 25 upwards via a flexible diaphragm 24 , so that it closes the one-way valve 21 , compresses the dispensing chamber 20 and releases its contents through a discharge passage 26 into the washing machine or the dryer. As it then cools, the wax 23 shrinks and the ram 25 is able to return to its initial position. This causes the one-way valve 21 to open and allows the dispensing chamber 20 to be filled again with active composition from the supply chamber 19 .
Also with the apparatus illustrated in FIGS. 7 and 8, the three chambers need not be exclusively disposed one above the other. The dispensing chamber 20 and the rigid chamber 22 may also be arranged adjacent to one another, for example. Similarly, one skilled in this particular art would have no difficulty in finding a suitable material other than wax. The only important thing about this material is that it should have an appropriate expansion coefficient at a selected operating temperature of the machine.
Likewise, the means 25 used to open the discharge passage 26 of the dispensing chamber 20 need not explicitly be a ram. It would also be conceivable to use a piston, for example rigid, which, because it is displaced by an expanding material, pushes the contents of the dispensing chamber, made from a very flexible material, to the discharge passage. To improve release of the active composition from the dispensing chamber, it would also be conceivable to provide more than one means for opening the discharge passage (e.g., two rams from two different positions).
In an alternative embodiment (which is not illustrated), the apparatus may also be activated on the basis of temperature by providing a bimetallic strip, which is deformed under the effect of temperature. This deformation directly or indirectly initiates the same procedure as that illustrated in FIGS. 7 and 8, where the ram 25 of the apparatus pushes via the diaphragm 24 , i.e., compresses the dispensing chamber 20 , opens the discharge passage 26 of the dispensing chamber 20 and, beforehand or simultaneously, closes the one-way valve 21 between supply chamber 19 and dispensing chamber 20 , in order to release the contents of the dispensing chamber substantially entirely into the machine. On cooling, the bimetallic strip would likewise return to its initial shape and as a result open the one-way valve 21 again to enable the dispensing chamber 20 to be re-filled with active composition from the supply chamber 19 .
In the case of a dishwashing machine, the temperature is normally increased twice during a dishwashing cycle, namely once during the cleaning cycle and a second time during the rinsing cycle. The temperature-dependent embodiments of the apparatus proposed by the invention would therefore be activated twice, i.e., an appropriate substance would be released into the dishwashing machine twice.
In all embodiments, the speed at which the fluid contained in the dispensing chamber is discharged can be controlled by appropriate means, for example by dimensioning the discharge passage 8 (FIG. 1 or 3 ), 17 (FIG. 6) or 26 (FIG. 8) accordingly. In this manner, a delayed release can be obtained to suit specific application requirements (for example releasing fabric conditioner in a dryer).
It is of advantage to provide means for inactivating the system, preferably of the type which do not have to be removed from the machine, so that the user can decide whether to run the machine with the system proposed by the invention in the activated state or in the non-activated state. Any type of locking mechanism that would prevent the opening mechanism 7 from being activated could be used for this purpose, preferably a system of blocking the hydraulic fluid 6 .
The features of the invention disclosed in the above description, the drawings and the claims may be construed as essential to the invention in its different embodiments, both individually and in any combination.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. | An apparatus for holding and dispensing metered doses of an active composition into a washing, drying or dishwashing machine has a supply chamber which holds at least double the amount of an individual dose of the active composition. A dispensing chamber is connected to the supply chamber by a passage in order to receive an individual dose of the active composition and to discharge the composition by way of a discharging passage. The closing of the passage between the supply chamber and the dispensing chamber, either beforehand or simultaneously, is actuated by means which are activated by conditions inside the machine, existing exclusively during a washing, drying or dishwashing cycle. The passage between the supply chamber and the dispensing chamber is re-opened and, beforehand or simultaneously, the discharging passage from the dispensing chamber is closed, so that the dispensing chamber can be re-filled from the supply chamber. | 3 |
FIELD OF THE INVENTION
[0001] This invention relates to a system and method whereby fuel-related taxes for motor vehicles are assessed and collected at the point of sale.
DESCRIPTION OF RELATED ART
[0002] Since 1993, the United States federal excise tax on gasoline has been 18.4 cents per gallon and 24.4 cents per gallon for diesel fuel. Taxes on gasoline are also imposed by the states. On average, as of April 2014, state and local taxes add 31.5 cents to gasoline and 31.0 cents to diesel, for a total US average fuel tax of 49.9 cents per gallon for gas and 55.4 cents per gallon for diesel. A majority of the federal gasoline tax revenue is used for bridge and road building, and the remainder is typically earmarked for other purposes.
[0003] At the Federal level, the majority of the taxes are collected when product is removed from the bulk storage terminals. The companies pay the tax to the Internal Revenue Service (IRS) and the money is deposited into the federal Highway Trust Fund, which comprises several different accounts for various end use purposes. The states within the United States have different rules for the point of taxation. Some states tax the product “at the rack,” which is upon removal from the bulk terminal, while other states impose the tax at the distributor level, having a series of approved bulk distributors, who hold licenses and file regular (usually monthly) returns where the state and local taxes are paid.
[0004] The United States is currently experiencing gasoline tax revenue shortages in relation to the demand for funds needed to maintain or improve the quality of the highways and bridges that are part of our ever-expanding network of roadways. Without additional revenues, the public roadways are likely to become more clogged, less safe, and less effective for use both by businesses and by individual consumers. These revenue shortfalls have prompted state legislatures to consider alternatives for financing of bridge and road infrastructure. Some pilot programs are presently being tested for possible use as alternatives to replace the federal gas tax. In California, a “vehicle miles traveled” (“VMT”) program is using a device installed in the vehicle to track the mileage driven with a charge of five cents per mile. In Oregon, drivers have volunteered to have mileage readers installed in their vehicles. More than 18 other states are also considering these types of programs to address the financial shortfall.
[0005] Substituting a VMT tax structure for the existing federal and state gasoline taxes offers advantages to consumers and promotes environmental consciousness while also potentially providing increased fuel tax revenues to the federal government and the states. However, changing the method of assessing and collecting fuel taxes, particularly to a system where the taxes are collected at the “point of sale” (“POS”), also poses challenges in regard to consumer privacy, security and ease of use. A system and method for assessing gasoline-related taxes based upon either actual or inferred VMT and for collecting gasoline-related taxes at the POS are now disclosed.
SUMMARY OF THE INVENTION
[0006] Assessing and collecting a tax for a motor vehicle fuel such as gasoline at the point of sale is believed to be an effective way to fund a large network of roadways using an existing point of sale infrastructure built upon the supply of fuel to motor vehicles. One approach, perhaps the simplest, is to set the tax as a flat number of cents per gallon and calibrate gasoline dispensing pumps to add that amount per gallon to a current “base price” for the particular grade of gasoline, and then remit the tax portion of the tax to the relevant federal or state taxing authorities according to predetermined reporting procedures when the purchase transaction is executed at the point of sale. As to the federal gasoline tax, this approach simply shifts the collection point but does not allow various tax rates to be imposed for different vehicles according to other relevant parameters.
[0007] Another approach is similar to the first, but also can take into consideration other factors such as, for example, the type of vehicle being driven, the geographical location of the point of sale, the type of fuel being purchased, etc. to set different fuel tax rates for different vehicles. One way to implement this is to establish tax tables that assign a particular rate code to each vehicle or purchase and provide an appropriate multiplier for each rate code to determine the amount of fuel tax to be added to the base price of the fuel. With a system and method of the invention configured in this way, various tax rates can be applied to different classes or categories of vehicles as a matter of policy to encourage or discourage certain behaviors rather than simply tying the fuel tax to the number of miles driven. Such behaviors can include, for example and without limitation, driving environmentally friendly vehicles; driving vehicles that cause less wear-and-tear on roads; driving in locations where the roadways or operating conditions are more maintenance-intensive; refueling at particular times or locations, and the like.
[0008] Still another approach is to charge the base price for each gallon of gasoline dispensed and then calculate an amount of tax based upon either the actual miles driven (“actual VMT”) or a VMT number that is inferred (“inferred VMT”) or determined from the quantity of fuel (e.g., gallons of gasoline) dispensed and the rated fuel efficiency (e.g., miles per gallon) of that vehicle. Using an inferred VMT makes the system less complex and alleviates privacy concerns associated with tracking actual miles driven for a particular vehicle and reporting that information every time that fuel is purchased.
[0009] The system and method disclosed here are useful for implementing any of the foregoing approaches but will desirably include a capability for assigning different tax rates to different vehicles based upon factors that are considered to be economically, environmentally or politically desirable. Although not required, a vehicle identification card (“VID”) is desirably used in conjunction with the system and method of the invention. Depending upon the configuration of a particular system, the VID can be used, for example and without limitation, to validate a particular user or vehicle, facilitate the transfer of information needed to determine an appropriate fuel tax rate, authorize use of a previously determined and assigned tax rate code, and/or to track total fuel taxes paid in relation to a particular user or vehicle. In more complex systems, information encoded on a VID can also be used to adjust the base price of fuel for a particular user, class of vehicle, or other predetermined parameter. Alternatively, where a VID is not used or available, a system of the invention can be configured to accept equivalent data that is entered manually, such as through a keypad, or to default to a default tax rate that is probably higher than would have been available to a user having a VID.
[0010] Each system of the invention will desirably include a reader or scanner to receive and interpret information received or obtained from the VID, a tax rate and price determination controller that can determine the appropriate tax rate and fuel price for a particular vehicle and transaction, a dispensing device such as a gasoline pump that can dispense fuel to a vehicle and track the quantity of fuel dispensed, a payment processor that can execute a transaction for a particular method of payment, and a payment distribution controller that can allocate portions of the purchase price to an identified account and execute or report such distributions in relation to fuel dispensed at a POS. If desired, all of the foregoing elements of the subject system except the VID can be incorporated into a single fuel dispensing device or into devices located at the POS.
[0011] Optionally, a separate VMT data source can also be included as part of, or be linked to, the system of the invention. Where a fuel tax assessment and collection program is based upon actual VMT, the system could also include a mileage tracking module internal to the vehicle and a data transfer component that can receive or download vehicle mileage data as part of a fuel purchase transaction. Where a fuel tax assessment and collection program is at least partially based upon inferred VMT, a VMT data source is not needed, as an inferred VMT can be calculated from the quantity of fuel dispensed and fuel efficiency ratings that are either encoded on the VID, pre-loaded into one of the tax rate determination controller, fuel dispenser and payment processor, or accessible through an electronic link to a database containing that information.
[0012] As another part of the present invention, a method is also disclosed through which the system of the invention can be used to execute a fuel purchase transaction in which a fuel tax rate is determined and is applied at a POS to calculate a total fuel purchase price that is then collected at the POS, after which the tax portion of the total purchase price is distributed to one or more identified accounts and reported in accordance with predetermined parameters and procedures. If desired, the subject method can incorporate the step of sourcing actual VMT data or calculating inferred VMT data that can be used in determining the rate and/or amount of fuel tax paid.
[0013] Although the system and method of the invention are principally disclosed here for use in determining, assessing and collecting federal and/or state taxes on gasoline, it will be appreciated by those of skill in the art upon reading this disclosure that the same or a similarly configured system and method can be used to tax other vehicular fuels at the POS. Thus, for example and without limitation, the assessment and collection of taxes or other payments for diesel fuel, compressed natural gas, propane, electricity for recharging batteries, and the like, can all be implemented if desired using the system and method of the invention.
[0014] Various embodiments of the system and method of the invention can utilize, include or take advantage of certain elements and components that are already existing, such as, for example, existing infrastructure and points of sale, funds handling and distribution networks already in place, fuel handling and distribution systems already being utilized, and the like. Those embodiments of the invention will desirably also include other elements not present in the prior art distribution systems and methods used for distributing gasoline and other motor vehicle fuels.
[0015] As mentioned above, some systems and methods of the invention will also desirably utilize vehicle identification devices (“VID”) that can readily read, scan or download and process information such as user identity, vehicle identification number (“VIN”) or, in some cases, VMT data. Some systems and methods of the invention can automatically distribute VMT or tax data to state agencies and/or to the U.S. Department of Transportation (“DOT”). Some systems and methods of the invention can be configured to automatically forward transactional information or funds to appropriate federal agencies or accounts. Some systems and methods of the invention can be configured for use in third party gift distribution systems; and the like.
[0016] At least some embodiments of the system and method of the invention will require or optionally include new elements, features and processes such as, for example, links to other databases or resources such as the website www.fueleconomy.gov for information concerning independent tests of vehicle fuel economy, or databases from which motor vehicle and owner identification information can be ascertained and verified.
[0017] Regardless of the particular embodiment of the invention that is selected for use in a particular application, or for a particular state or geographical locale, principal features of the invention are the capabilities for assessing and collecting a vehicle fuel tax at a gas pump or cash register disposed at the POS as part of a typical fuel purchase transaction.
[0018] VMT-based fuel tax systems can, but do not necessarily involve tracking a user's path across a defined geographical territory The technology needed to do this is already available, and can, for example, selectively include the of global positioning systems (“GPS”), Wi-Fi hotspots, cellular tower triangulation, gyroscopic/altimeter/accelerometer data, or a combination of some or all of these. However, concerns about collecting and reporting mileage and other driving data for individual users or vehicles directly to a governmental entity and also linking that data to financial information for the same user. Those concerns predictably relate to issues such as how reliably the data be secured, how the identities and financial information of individual users can be protected, and what uses of the data are permitted—all while still reliably tracking and reporting vehicle movement for purposes of levying and collecting taxes. These and other concerns are satisfactorily addressed in the system and method disclosed here by basing the vehicle fuel tax on inferred rather than actual VMT.
[0019] The system and method of the invention will provide a closer tie between vehicle travel and the funding and maintenance of roadway infrastructure and services and can be readily modified for optional use or to include ancillary enhancements, capabilities and benefits such as, for example, providing a third-party gift card distribution component. These and other features, benefits and advantages of the subject invention are further illustrated, described, explained and claimed below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The system and method of the invention are further described and explained in relation to the following drawings wherein:
[0021] FIG. 1 is a simplified diagrammatic view of one embodiment of the system for assessing and collecting a tax on motor vehicle fuel at the point of sale;
[0022] FIG. 2 is a simplified diagrammatic view of one embodiment of the method of the invention in a progression that exemplifies a fuel purchase transaction;
[0023] FIG. 3A is a simplified diagrammatic view of the first of three sequential portions (including FIGS. 3A, 3B, 3C , respectively) that collectively illustrate another embodiment of the method of the invention in a progression that, when viewed from left to right, respectively, exemplifies a fuel purchase transaction, wherein “circled A” and “circled B” are match points designating the points of connection between FIG. 3A and FIG. 3B ;
[0024] FIG. 3B is a simplified diagrammatic view of the second of three sequential portions (including FIGS. 3A, 3B, 3C , respectively) that collectively illustrate an embodiment of the method of the invention in a progression that, when viewed from left to right, respectively, exemplifies a fuel purchase transaction, wherein “circled A” and “circled B” are match points designating points of connection between FIG. 3A and FIG. 3B , and wherein “circled C” and “circled D” are match points designating points of connection between FIG. 3B and FIG. 3C ;
[0025] FIG. 3C is a simplified diagrammatic view of the third of three sequential portions (including FIGS. 3A, 3B, 3C , respectively) that collectively illustrate an embodiment of the method of the invention in a progression that, when viewed from left to right, respectively, exemplifies a fuel purchase transaction, wherein “circled C” and “circled D” are match points designating points of connection between FIG. 3B and FIG. 3C ;
[0026] FIG. 4A is a simplified diagrammatic view of the first of two sequential portions (including FIGS. 4A and 4B , respectively) that collectively illustrate, when viewed from left to right, respectively, a method wherein an annual inspection is used as a reference point at which a VID is issued, updated or certified, that verifies the vehicle, owner and mileage and can optionally be used to link multiple vehicles for purposes of fuel purchase transactions, and wherein “circled E” and “circled F” are match points designating points of connection between FIG. 4A and FIG. 4B ; and
[0027] FIG. 4B is a simplified diagrammatic view of the second of two sequential portions (including FIGS. 4A and 4B , respectively) that collectively illustrate, when viewed from left to right, respectively, a method wherein an annual inspection is used as a reference point at which a VIS is issued, updated or certified, that verifies the vehicle, owner and mileage and can optionally be used to link multiple vehicles for purposes of fuel purchase transactions, and wherein “circled E” and “circled F” are match points designating points of connection between FIG. 4A and FIG. 4B .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] Referring to FIG. 1 , an embodiment of system 10 of the invention is disclosed that comprises vehicle identification device 20 , reader or scanner 30 , tax rate determination controller 40 , fuel dispensing device 50 (shown here as a pump), payment processor 70 and payment distribution controller 80 . VMT data source 60 is an optional component for use in systems of the invention wherein vehicle miles traveled enter into the computation of the fuel tax owed by an identified vehicle. Vehicle 90 is depicted outside the dashed box defining the boundary of this embodiment of system 10 because the vehicle itself is not necessarily part of the system of the invention.
[0029] System 10 is depicted as being bounded by a dashed outline that can for some embodiments of the invention be considered to be an indication of the point of sale. It should be appreciated, however, that the physical boundaries of system 10 can vary widely within the scope of the invention. In some embodiments of the invention, every element depicted inside system 10 can be disposed in a single gasoline pump. In other embodiments of the invention, some elements of system 10 can be disposed at the vehicle fuel pump, others can be disposed inside a gas station or convenience store associated with the vehicle fuel pump, or even at another offsite location. For example, the vehicle identity can be determined at the fuel pump, payment can be processed at the pump or inside an associated office or store, and payments can be distributed from an offsite location located many miles away, or perhaps in another state.
[0030] During use of system 10 in accordance with one satisfactory embodiment of the method of the invention, users will need to acquire a VID 20 , typically a card comprising a magnetic stripe or electronic chip comprising encoded information including, for example, the vehicle identification number (“VIN”) and such other supplemental information as may be required. Such supplemental information could include, for example, the vehicle owner's name, address, driver license number, vehicle inspection certification and insurance certification and carrier. VID 20 is desirably issued by a designated state or federal agency, or by authorized service providers who are licensed to issue VIDs. According to another embodiment of the invention, a vehicle owner is assigned a fuel purchase authorization number after registering with the DMV, DOL, or state vehicle registration facility, and then enters the authorization number on a keypad at a POS. According to yet another embodiment of the invention, a vehicle is equipped with a VID 20 in the form of an electronic chip that can be read by a scanner or reader 30 whenever a motor vehicle is parked beside a fuel dispenser or, for example, when the nozzle of a gas pump is inserted into the refueling spout of a motor vehicle parked at a POS. If desired, a tax rate code for a particular vehicle can be assigned at the time the vehicle is registered for use with a tax assessment and collection system 10 , or can be applied (or overridden) by tax rate determination controller 40 under appropriate circumstances.
[0031] Where VID 20 is a card, it can be scanned or swiped as indicated by arrow 25 in FIG. 1 at a fuel dispensing pump 50 or another identified location at the POS to initiate a fuel purchase transaction. For this purpose, a reader or scanner 30 is desirably provided, and is linked either directly or remotely to tax rate determination controller 40 , as indicated by arrow 35 in FIG. 1 . If desired, tax rate controller 40 can be integrated into a programmable logic controller (“PLC”) or other central processing unit (“CPU”) that can also be programmed to perform other functions associated with system 10 and the method of the invention.
[0032] The tax rate determination controller 40 desirably determines an appropriate fuel tax rate to be applied to a particular vehicle, either from data entered from the scanner or reader 30 or otherwise input into system 10 from tables programmed into controller 40 , and desirably forwards the fuel tax rate (or code) to pump 50 as indicated by arrow 45 in FIG. 1 . If desired, controller 40 can also determine a fuel tax rate for an identified vehicle 90 based wholly or in part on information received as indicated by arrow 65 in FIG. 1 from an optionally provided VMT data source 60 . Where fuel tax assessment and collection system 10 of the invention is configured to assess the fuel tax according to a protocol that takes into consideration the actual VMT over a given time increment (such as, for example, the elapsed time since the last prior fuel purchase), VMT data source 60 can desirably determine either the actual VMT or current mileage from a “sender” disposed in vehicle 90 . Where VMT data source 60 simply captures the current mileage reading for vehicle 90 , the actual VMT can determined by difference, particularly where tax rate determination controller 40 comprises a data link to a database where such information is maintained.
[0033] According to another embodiment of the invention where the fuel tax rate takes into consideration an inferred VMT, the tax rate determination controller 40 and pump 50 are cooperatively configured to compute an inferred VMT taking into consideration the quantity of fuel dispensed and the fuel efficiency or average mileage rating for that class of vehicle 90 , and then use the inferred VMT to determine the fuel tax rate or amount. In such case, arrow 45 may be more properly depicted as having arrows pointing both directions to more accurately reflect that information is being shared by controller 40 and pump 50 in determining the total amount of fuel tax to be assessed to the purchaser at the POS. It will also be appreciated by the reader of this disclosure that these functions can all be performed by a single PLC that is either resident inside pump 50 or otherwise electronically linked to pump 50 .
[0034] After fuel is dispensed by pump 50 into vehicle 90 as indicated by arrow 85 of FIG. 1 , payment processor 70 receives or calculates and desirably displays the total amount to be charged to and collected from a motor fuel purchaser at the POS. If desired, the base fuel price per unit volume (e.g., $/gal, /liter, cents/ft 3 , cents/Kwh) can be displayed together with the total base fuel price, the applicable tax rate or code, the total tax amount, and the total sales price for the transaction. Payment is desirably processed by payment processor 70 at the POS in the customary fashion, either at the pump or inside a kiosk, gas station or convenience store, for example, with payment being made in any acceptable form, such as cash, check, debit or credit. Payment processor 70 can be integrated into fuel dispensing pump 50 at the POS, and will desirably also have the capability of generating a digital and, optionally, paper record of the payment and other predetermined information relating to the fuel purchase transaction.
[0035] Referring again to FIG. 1 , information regarding the amount of fuel tax assessed and collected is also desirably forwarded to a payment distribution controller 80 as indicated by arrow 75 for distribution to such predetermined accounts and in accordance with such procedures and controls as may have been established and programmed into system 10 .
[0036] Examples of motor fuel purchase transactions for different vehicles or circumstances are provided below to illustrate further how various embodiments of the system and method of the invention can be used in motor vehicle fuel purchase transactions to determine, assess and collect fuel taxes:
EXAMPLE 1
[0037] Vehicle A: avg fuel economy is 42 mpg, tax table entry 2, base tax 0.50 cents/gallon, tax table multiplier for tax table entry 2 is 1.25% yielding 0.625 cents/gallon, purchases 10 gallons, pays $6.25 in total gas tax.
EXAMPLE 2
[0038] Vehicle B: avg fuel economy is 22 mpg, tax table entry 7, base tax 0.50 cents/gallon, tax table multiplier for tax table entry 7 is 1.95% yielding 0.975 cents/gallon, purchases 10 gallons, pays $9.75 in total gas tax.
[0039] In the two examples provided above, the base price per gallon of motor fuel is desirably posted at the POS. If the motor fuel tax assessment and collection program approved for use in a particular jurisdiction permits, there may be a “default” tax rate that applies in circumstances where, for example and without limitation, a single “default” rate is applied unless otherwise modified or exempted, or a vehicle operator does not have a VID for the vehicle being refueled, or a vehicle operator has not registered and received a purchaser identification number.
EXAMPLE 3
[0040] A motor vehicle is purchased and the owner is issued a VID that includes the VIN. When fuel is purchased, the VID is scanned at the POS and assigns a fuel tax rate according to the vehicle class (e.g., passenger sedan; high performance; SUV; light truck; hybrid; etc.). The fuel dispensing device at the POS adds the appropriate tax (or taxes if both federal and state or federal, state and local fuel taxes are levied) to the base fuel price, and the purchaser is charged for the measured amount of fuel dispensed and the total taxes. When payment is made, the appropriate amounts of tax are distributed to previously designated accounts for the various taxing authorities or agencies.
EXAMPLE 4
[0041] This example is substantially the same as with EXAMPLE 2, except that the fuel tax is based upon inferred VMT rather than other differentiating factors such as, for example, vehicle weight, vehicle cost, or the like. In this case, a base VMT is established by the federal government and is optionally increased by state and/or local governments if permitted. The total VMT includes all applied tax rates, similar to how the gas tax is currently calculated.
EXAMPLE 5
[0042] In this example, the vehicle class tax rate is standardized and regulated by the United States Government based on vehicle class. The vehicle class tax rate is assigned to each vehicle based on the VIN. The vehicle class represents a grouping of similar vehicle miles per gallon ratings. The vehicle class tax rate is determined using factors such as historical VMT per capita, vehicle sales statistics, and federal, state, and local tax burden needs. This approach to establishing applicable tax rates can help create consistency and improve public acceptance.
EXAMPLE 6
[0043] In this example, the vehicle class tax rate is outlined in a VMT class chart. The VMT class chart is posted somewhere on the premises of the POS for purposes of user notification. The driver presents proof of vehicle class tax rate via the VID at the POS and a percentage of discount is applied to the base rate.
[0044] Other alternative embodiments of the invention can likewise be similarly configured to reflect other policy objectives or deal with other circumstances that can be reasonably anticipated or otherwise arise. By way of example, and again without limitation, the DMV, DOL, or state vehicle registration facilities/merchants can provide the VID. VID card readers can be configured to simply assign vehicle tax rate to the purchase and not record the POS. The gas price that is displayed on signage can be required to include the highest allowable fuel tax rate as a default tax rate that is charged to purchasers who do not have a valid VID or assigned purchase number. Older fuel d/dispensing stations lacking electronic payment equipment or other equipment needed to implement preferred embodiments of the subject system and method can be required to levy the highest allowable tax rate to encourage them to invest in upgraded equipment or for other purposes. Incrementally higher tax rates can be applied to purchasers who manually input a required user number in view of the higher risk of entering incorrect information in such cases. Alternate IDs can be registered and used to purchase fuel under identified circumstances, perhaps at higher identified tax rates. For compressed gas or electric or hybrid-fueled vehicles, special tax rates may need to be established that take into consideration factors relevant to their implementation and use.
[0045] In implementing the system and method of the invention, certain rules, restrictions and business practices may also need to be implemented to avoid compromising the overall objectives of the fuel tax assessment and collection system. Such considerations can include, for example, insisting that the issuance of VIDs be limited to governmental agencies such as state traffic enforcement agencies, and that only one VID be issued per vehicle.
[0046] Referring to FIG. 2 , a simplified, self-explanatory flowchart is depicted that illustrates the configuration and use of one embodiment of the system and method of the invention in a progression that exemplifies a fuel purchase transaction using the system and method of the invention. As used here, the term “self-explanatory” assumes that the reader is one of ordinary skill in the art who has already read and understands the foregoing text of this application and the system and method of the invention as characterized, explained and discussed in relation to the foregoing Summary and discussion of the embodiment of FIG. 1 .
[0047] Referring to FIG. 3 , a more detailed, self-explanatory flowchart is depicted that illustrates the configuration and use of one embodiment of the system and method of the invention in a progression that exemplifies a fuel purchase transaction using the system and method of the invention.
[0048] Referring to FIG. 4 , an expanded, self-explanatory flowchart is depicted that illustrates another embodiment of the invention wherein an annual vehicle inspection (not required by all states) is used as a reference point at which an existing VID is issued, updated or certified, that verifies the vehicle, owner and mileage and can then optionally be used to link multiple vehicles for purposes of fuel purchase transactions.
[0049] Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading this specification in view of the accompanying drawings, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventor(s) and/or Applicant are legally entitled. | A system and method for assessing and collecting taxes for fuel for motor vehicles at the point of sale through use of a vehicle identification device; a reader or scanner to receive and process information received or obtained from the vehicle identification device; a tax rate and price determination controller that can determine an appropriate tax rate to be added to a base fuel price; a dispensing device configured to dispense motor fuel to an identified vehicle and track the quantity of motor fuel dispensed; a payment processor that can determine a total purchase price having at least a base fuel price component and at least one fuel tax component, and execute a payment transaction for a particular method of payment; and a payment distribution controller that can allocate portions of the total purchase price to an identified account and execute or report such distributions. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to devices used in cooperation with a jack to remove posts which are embedded in the ground. Posts are used for many applications, but may be for purposes herein can be of the type to support a fence. Over time, it is at many times necessary to remove them from the ground.
While prior devices for removing post are considered to be useful, often they are inconvenient to use, expensive to manufacture, and in some instances even dangerous to the individual using them. Accordingly, there exists a need for an improved post remover, that is easy to transport, effective, simple to use and is safe.
2. Description of Prior Art
Posts are commonly made of metal or wood, but may be of plastic or other material. A concrete footer is commonly employed to secure the post in the ground. Many times such posts are required to be removed. The removal of such post can be quite difficult.
Unsuccessful removal of a post by hand can result in a broken portion of the post and footer remaining secured in the ground. This necessitates digging around the footer to remove the concrete and attached post portion.
Further, posts come in a variety of cross-sectional shapes and diameters. The cross-section may be round or rectangular shaped, for example. Accordingly, prior post pulling tools are designed to remove a particular cross sectional shape.
For example, U.S. Pat. No. 5,224,687 issued to Geckler discloses a device for removing a post with a “T” shaped cross-section which utilizes an engagement plate and a conventional jack. Similarly, the post pulling apparatus described in U.S. Pat. No. 6,302,377 issued to Pimented uses a square sleeve adapted to receive a square post and has similar limitations. These representative prior art devices are limited to removing posts with a certain cross sectional shape and therefore cannot be used for removing stakes with differing cross-sectional shapes or sizes.
Further, prior post pullers typically must be placed over the top of the post or post and brought down to the proper position before removal. This requires the user to remove nails or other obstructions before the device can be used. Such a requirement increases the overall time and work required.
Accordingly, there is a need for a device which can quickly remove a post with minimal effort. Further, there is a need for a post puller that can remove posts of varying cross-sectional sizes and shapes. There also remains a need for a post puller which can remove post with an attached concrete footer thereto.
While the above described devices have similarities with the present invention, they differ in material respects. These differences reveal advantages over the prior devices.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a device for removing post from the ground.
It is also an object of the invention to reduce the amount of work required to remove post from the ground.
Another object of the invention is to provide a device for removing post which can dislodge an embedded fence post by engaging any exposed location along the length of the fence post.
Still another object of the invention is to provide a device for removing post that is easier and less costly to manufacture.
Yet another object of the invention is to provide a device for removing post that is compatible for use with a variety of jacks.
An object of the invention is to provide a device for removing post that is adapted to engage posts of varying sizes and shapes.
Another object of this invention is to provide a device that can pull wood or metal posts from the ground without requiring the user to exchange engagement heads.
Yet another object of the invention is to provide a device for removing post that is capable of at least partially circumferentially disposing its base about the post and an attached concrete footer in a manner which enables an upward force on the post parallel with the position of the post to remove both the post and concrete.
Another object of this invention is to provide a device for removing and transporting post of a variety of sizes and weights that is easy to use and easily operated by one person.
It is another object of the invention to provide a device for removing post which is durable in construction, compact and can be easily moved from place to place.
Another object of the invention is to provide a device for removing post which can be manufactured efficiently and reliably.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing a preferred embodiment of the invention without placing limitations thereon.
Accordingly, there is provided a device for removing post that is constructed in accordance with the principles of the present invention. The device for pulling a post from the ground includes a movably disposable base which is capable of disposal about the planted post, a diametrically adjustable member connected to the base for securely gripping about the post, and a jack connected to the gripping member for mechanically displacing the gripping member and in turn the fence post from the ground. The base is generally U-shaped having a pair of opposing arms and a transverse portion connecting said arms in hereby said arms are disposable on about the post.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side perspective of the device of the present invention.
FIG. 2 is a top view of base components of the invention.
FIG. 3 is a perspective view of the invention in use
FIG. 4 is a view of a tool for aiding the device.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, the device for pulling fence post or the of the present invention is a generally designated by the numeral 10 . The device includes a generally U-shaped base 12 . The base 12 includes a plate member 14 of steel, for can be of any suitable rigid material. The base 12 has a pair of opposing arms 16 and transverse portion 18 .
A pair of side plate members 20 which serve as upright side retaining members for the post P, which can also be steel, extend generally perpendicular to the base 12 and diagonally outward to form a V-shaped seat as seen in FIG. 2 which aid the transportation of the post P. The members 20 are fixed to the base 12 by welding. A pair of axle frame support members 22 can also be of steel and welded to base 12 . The members 22 are tapered or angled having an axle bearing open surface 24 formed therein. A tapered portion 25 serves to provide clearance needed to tilt the device 10 when moving the same.
An axle 26 extends through the bearing open surface 24 . Wheels 28 are attached to the axle 26 . Bores 30 extend through the ends of the axle 26 to receive lock pins 32 . By way of example, a vertical member 34 , which can be steel, is connected via weld to the base 12 and members 20 . The vertical member 34 can be steel tubing and of a predetermined height, say two feet to aid in leveraging the weight, transferring and transporting the post P. A universal sleeve neck 36 is connected, via welding for example, to the vertical member 34 .
An elongated vertical jack portion 38 extends from the sleeve 36 and serves as a track for a jack head 44 . The sleeve 36 can be such to accept a variety of vertical jack portion designs. The portion 38 includes a plurality of incrementally spaced surfaces 40 which terminate adjacent and upper capped end 42 . The head 44 includes a sleeve 46 , which slidably receives the vertical portion 38 therethrough. A ratchet arm 48 pivotally connects to the sleeve 46 to enable secure selective positioning of the sleeve 48 along the portion 38 . A handle 50 is attached to the arm 48 and is provided as an additional leverage tool to achieve greater raising force with minimal exertion. Also, attached to the sleeve 46 is head 52 . A chain 56 removably connects to the head 52 and is provided with a grab hook 58 .
The vertical member 34 has a horizontal bore 60 through which a bolt 62 extends. A foot 66 rests on the end of the bolt 62 and is for use in supporting the vertical member 34 when not connected to the sleeve 36 . When seated in the sleeve 36 , a bolt 68 extends through a bore 64 of the sleeve 36 and one of the lower spaced surfaces 40 to secure the jack portion 38 to the sleeve 36 .
The head is formed with a bore 69 through which a bolt 70 extends and is fixed by a nut 71 . The bolt 70 prevents a looped portion of the chain 56 as seen in FIGS. 1 and 3 from passing over the end of the head 52 . The looped portion of the chain 56 is formed by connecting and end link of the chain 56 to another link by a bolt 72 and nut 73 . Another end of the chain 56 is connected to an opening 75 of the hook 58 . The hook 58 is configured with a slot 74 to enable it to be connected to another link in the chain 56 as seen in FIGS. 1 and 3.
FIG. 4 depicts an eye bolt 76 and a plate 78 connected thereto at eyelet 79 which aid in removing broken post. Here, the bolt 76 screws into the remaining portion of the post. The plate 78 includes a keyed opening 80 for receiving the chain 56 therethrough in a fixed position.
The operation is as follows. The device 10 is configured to be wheeled over most terrain and disposed with its base 12 substantially encompassing an area in which the post P and a given amount of concrete disposed within the ground. The U-shaped base 12 is thus of a size such that the opening defined between the arms 16 and transverse portion 18 typically is large enough to enable the post P with an associated predetermined amount of concrete C to be pulled out of the ground G without having to disjoin the same. Once positioned, the chain 56 is wrapped about the post P and the hook 58 affixed to the head 52 , for example. The jack 44 is then operated to cause the sleeve 46 , head 52 , chain 56 and in turn the post P to be vertically displaced from its planted position. Note, in the case of the broken post, the bolt 76 and tool 78 can be used as described above.
The side members 20 form a seat or cradle for the post P and associated concrete C once pulled from the ground G so that when the device 10 is tilted for transport, the post P and concrete C is securely held in place until the same is at a desired position for disposal.
The above described embodiment is set forth by way of example and is not for the purpose of limiting the present invention. It will be readily apparent to those skilled in the art that obvious modifications, derivations and variations can be made to the embodiment without departing from the scope of the invention. Accordingly, the claims appended hereto should be read in their full scope including any such modifications, derivations and variations. | A device for removing post id provided and includes a movably disposable base which is capable of disposal at least partially circumferentially about the planted post, a diametrically adjustable member connected to the base for securely gripping about the post, and aback connected to the gripping member for mechanically displacing the gripping member and in turn the fence post from the ground. | 4 |
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 15/142,934, filed Apr. 29, 2016, with title ROTATIONAL POSITIONAL MONITORING OF VEHICLE LIFTS, which is hereby incorporated by reference herein.
BACKGROUND
[0002] Vehicle lift systems may be used to lift various kinds of vehicles relative to the ground. Some vehicle lifts operate by positioning two runways at, or near, a shop floor level. The vehicle may be then driven or rolled onto the runways, allowing the runways to support the vehicle. The underside of each runway may be attached to a plurality of hydraulically driven lifting assemblies. The lifting assemblies may be actuated to raise the runways and the vehicle to a desired height. Afterward, the vehicle may then be lowered once the user has completed his or her task requiring the vehicle lift. In some cases, the lifting assemblies may comprise a single elongated member which may rotate relative to the floor to pivot the runways upwardly. In other cases, the lifting assemblies may comprise a plurality of linkages which pivot relative to one another to cause the runways to rise upwardly, similar to a pair of scissors.
[0003] Other vehicle lift systems are formed by a set of mobile, above-ground lift columns. An example of a mobile column lift system is the MACH 4 Mobile Column Lift System by Rotary Lift of Madison, Indiana. Each mobile column may include a hydraulically driven lifting assembly. The mobile columns may be readily positioned in relation to the vehicle. The mobile columns may then be activated such that lifting assemblies actuate to raise the vehicle from the ground in a coordinated/synchronized fashion. The mobile columns may be controlled through wireless communication with a wireless control center. The wireless control center may associate with each mobile column in order to form a synchronized lift.
[0004] While a variety of systems and configurations have been made and used to control lift systems, it is believed that no one prior to the inventors has made or used the invention described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:
[0006] FIG. 1A shows a perspective view of an exemplary hydraulic cylinder assembly in a withdrawn position;
[0007] FIG. 1B shows a perspective view of the hydraulic cylinder assembly of FIG. 1A in an expanded position;
[0008] FIG. 2 shows a partial cross-sectional exploded view of the hydraulic cylinder assembly of FIG. 1A ;
[0009] FIG. 3 shows a cross-sectional perspective view of the hydraulic cylinder assembly of FIG. 1A ;
[0010] FIG. 4A shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 1A ;
[0011] FIG. 4B shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 1A and 1B in a partially expanded position;
[0012] FIG. 4C shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 1B ;
[0013] FIG. 5 shows a perspective view of an exemplary vehicle lift with the hydraulic cylinder assembly of FIG. 1A ;
[0014] FIG. 6A shows a side elevational view of the vehicle lift of FIG. 5 in a retracted position;
[0015] FIG. 6B shows a side elevational view of the vehicle lift of FIG. 5 is an extended position;
[0016] FIG. 7 shows an exploded perspective view of a lift assembly of the vehicle lift of FIG. 5 ;
[0017] FIG. 8A shows a perspective view of the lift assembly of FIG. 7 , with the lift assembly in a retracted position;
[0018] FIG. 8B shows a perspective view of the lift assembly of FIG. 7 , with the lift assembly in an extended position;
[0019] FIG. 9A shows a cross-sectional elevation view of an alternative hydraulic cylinder assembly in a retracted position, where the alternative hydraulic cylinder assembly may be used in place of the hydraulic cylinder assembly of FIG. 1A ;
[0020] FIG. 9B shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 9A in a partially expanded position;
[0021] FIG. 9C shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 9A in an expanded position;
[0022] FIG. 10A shows a cross-sectional elevation view of another alterative hydraulic cylinder assembly in a retracted position, where the alternative hydraulic cylinder assembly may be used in place of the hydraulic cylinder assembly of FIG. 1A ;
[0023] FIG. 10B shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 10A in a partially expanded position;
[0024] FIG. 10C shows a cross-sectional elevation view of the hydraulic cylinder assembly of FIG. 10A in an expanded position.
DESCRIPTION
[0025] The following description of certain examples should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
A. Exemplary Hydraulic Actuator Assembly
[0026] FIGS. 1-4C show an exemplary hydraulic actuator assembly ( 100 ) that may be readily incorporated into a variety of vehicle lift assemblies. As best shown in FIG. 2 , hydraulic actuator assembly ( 100 ) includes a cylinder assembly ( 110 ), a linear actuating assembly ( 120 ), and a linear displacement measuring assembly ( 130 ). As will be described in greater detail below, linear actuating assembly ( 120 ) may move relative to cylinder assembly ( 110 ) from a fully withdrawn position, as shown in FIG. 1A , to a fully extended position, as shown in FIG. 1B . Additionally, linear actuating assembly ( 120 ) may move to any number of positions between the fully withdrawn and the fully extended position. Therefore, movement of linear actuating assembly ( 120 ) may be utilized in order to actuate a vehicle lift assembly in order to raise or lower a vehicle to a desired height. Such vehicle lift assemblies may include a scissor lift assembly, a carriage style lift assembly, an in-ground lift assembly, an above-ground lift assembly, or any other suitable lift assembly that would be apparent to one having ordinary skill in the art.
[0027] Cylinder assembly ( 110 ) includes a hydraulic cylinder ( 102 ) and an attachment feature ( 112 ). While in the current example, hydraulic cylinder ( 102 ) and attachment feature ( 112 ) are unitarily connected, it should be understood that hydraulic cylinder ( 102 ) and attachment feature ( 112 ) may be fixedly coupled with any other suitable means known to a person having ordinary skill in the art in view of the teachings herein. For example, hydraulic cylinder ( 102 ) and attachment feature ( 112 ) may be fixedly coupled with a plurality of nuts and bolts.
[0028] Attachment feature ( 112 ) is located at the bottom of hydraulic cylinder ( 102 ) in order to couple cylinder assembly ( 110 ) to a portion of a vehicle lift assembly, as will be described in greater detail below. In the current example, attachment feature ( 112 ) is configured to receive a pin ( 298 ) (see FIG. 7 ) in order to attach hydraulic cylinder ( 102 ) to a portion of a vehicle lift assembly. Therefore, attachment feature ( 112 ) may allow hydraulic actuator assembly ( 100 ) to rotate about an axis defined by pin ( 298 ). In other words, hydraulic cylinder ( 102 ) may be rotatably coupled to a portion of a vehicle lift assembly (e.g., a lift assembly ( 250 ) as shown in FIG. 5 ) via attachment feature ( 112 ).
[0029] However, it should be understood that rotational capabilities of attachment feature ( 112 ) are merely optional. Some vehicle lift assemblies do not require rotation of hydraulic cylinder ( 102 ) in order to raise or lower a vehicle. For example, hydraulic cylinder ( 102 ) may alternatively be slidably coupled to a portion of vehicle lift assembly. Hydraulic cylinder ( 102 ) may alternatively be fixedly coupled to a portion of a vehicle lift assembly (e.g., a lift assembly ( 250 ) as shown in FIG. 5 ). Any suitable attachment feature known by a person having ordinary skill in the art in view of the teachings herein may be employed.
[0030] Turning to FIG. 2 , hydraulic cylinder ( 102 ) includes an interior base end ( 116 ), an interior annular wall ( 114 ), and an interior head end ( 118 ); all of which collectively define a cavity ( 106 ). Head end ( 118 ) further defines a tunnel ( 104 ) extending from cavity ( 106 ) to an exterior of hydraulic cylinder ( 102 ). Tunnel ( 104 ) is dimensioned to slidably house a rod ( 122 ) of linear actuating assembly ( 120 ) while cavity ( 106 ) is dimensioned to slidably house a plunger ( 124 ) of linear actuating assembly ( 120 ). Plunger ( 124 ) and rod ( 122 ) are coupled with each other such that plunger ( 124 ) and rod ( 122 ) slide relative to tunnel ( 104 ) and cavity ( 106 ) together.
[0031] Hydraulic cylinder ( 102 ) also has a fluid channel ( 107 ) associated with the base end ( 116 ) and a fluid channel ( 105 ) associated with the head end ( 118 ). Each fluid channel ( 105 , 107 ) is in fluid communication with a chamber ( 106 A, 106 B) of cavity ( 106 ), respectively. Chamber ( 106 A) is defined by interior base end ( 116 ), interior annular wall ( 114 ), and a radial face ( 136 ) of plunger ( 124 ). Chamber ( 106 B) is defined by interior head end ( 118 ), interior annular wall ( 114 ), and a radial face ( 134 ) of plunger ( 124 ). It should be understood that because plunger ( 124 ) is slidable within cavity ( 106 ), chambers ( 106 A, 106 B) are capable of changing volume as plunger ( 124 ) actuates within cavity ( 106 ).
[0032] Each fluid channel ( 105 , 107 ) may fill respective chamber ( 106 A, 106 B) with hydraulic fluid. Tunnel ( 104 ) and rod ( 122 ) may fluidly isolate chamber ( 106 B) from the exterior of hydraulic cylinder ( 102 ) by using a seal gland or in any other suitable manner known to the art in view of the teachings herein. As will be described in greater detail below, fluid channels ( 105 , 107 ) may help actuate plunger ( 124 ) within cavity ( 106 ).
[0033] Base end ( 116 ) further defines a rotary sensor mount ( 108 ) dimensioned to house a rotary sensor ( 140 ). Rotary sensor mount ( 108 ) is capable of fixing a portion of rotary sensor to hydraulic cylinder ( 102 ). While in the current example, rotary sensor mount ( 108 ) is a recess defined by base end ( 116 ), bolts, nuts, threaded rods, or any other suitable structures may be utilized to fix a portion of rotary sensor ( 114 ) to hydraulic cylinder ( 102 ).
[0034] Linear actuating assembly ( 120 ) includes rod ( 122 ) having one end fixed to plunger ( 124 ) and another end fixed to an attachment feature ( 126 ). Rod ( 122 ) defines channel ( 128 ). Channel ( 128 ) extends from the portion of rod ( 122 ) that is fixed to plunger ( 124 ) toward the portion of rod ( 122 ) fixed to attachment feature ( 126 ). Rod ( 122 ) also has a pin ( 125 ) located at the portion of rod ( 122 ) fixed to plunger ( 124 ). As will be described in more detail below, channel ( 128 ) and pin ( 125 ) are dimensioned to interact with linear displacement measuring assembly ( 130 ) to measure the distance linear actuating assembly ( 120 ) actuates relative to cylinder assembly ( 110 ). This information may be utilized to determine the individual height of each hydraulic actuator assembly ( 100 ) in a vehicle lift system. A vehicle lift system may utilize this data in order to level a vehicle lift system, to limit or manage movement of linear actuating assembly ( 120 ), and for other purposes as will occur to those skilled in the art.
[0035] While in the current example, rod ( 122 ) and attachment feature ( 126 ) are unitarily connected, it should be understood that rod ( 122 ) and attachment feature ( 126 ) may be fixedly coupled with any other suitable means known to a person having ordinary skill in the art in view of the teachings herein. For example, rod ( 122 ) and attachment feature ( 126 ) may be fixedly coupled with a plurality of nuts and bolts.
[0036] Attachment feature ( 126 ) is located at the top of rod ( 122 ) in order to couple rod ( 122 ) to a portion of a vehicle lift assembly, as will be described in greater detail below. In the current example, attachment feature ( 126 ) is configured to receive a pin ( 300 ) in order to attach rod ( 122 ) to a portion of a vehicle lift assembly. Therefore, attachment feature ( 126 ) may allow hydraulic actuator assembly ( 100 ) to rotate about an axis defined by pin ( 300 ). In other words, rod ( 122 ) may be rotatably coupled to a portion of vehicle lift assembly via attachment feature ( 126 ).
[0037] However, it should be understood that rotational capabilities of attachment feature ( 126 ) are merely optional. Some vehicle lift assemblies do not require rotation of rod ( 122 ) in order to raise or lower a vehicle. For example, rod ( 122 ) may be fixedly coupled to a portion of a vehicle lift assembly, or any other suitable attachment feature known by a person having ordinary skill in the art in view of the teachings herein may be employed.
[0038] As mentioned above, rod ( 122 ) is slidably housed within tunnel ( 104 ) of hydraulic cylinder ( 102 ). Plunger ( 124 ) may be fixed to rod ( 122 ) by threads, bolts, or nuts, or any other structures known to one having ordinary skill in the art in view of the teachings herein. As mentioned above, plunger ( 124 ) is slidably housed within cavity ( 106 ). Plunger ( 124 ) is also positioned and dimensioned such that a circumferential face ( 132 ) of plunger ( 124 ) makes contact with interior annular wall ( 114 ). Circumferential face ( 132 ) of plunger ( 124 ) may be machined with grooves configured to fit elastomeric or metal seals and bearing elements. Plunger ( 124 ) is configured to separate cavity ( 106 ) into two fluidly isolated chambers ( 106 A, 106 B). Therefore, first chamber ( 106 A) and second chamber ( 106 B) defined by cavity ( 106 ) and plunger ( 124 ) may fill or empty with fluid via fluid channels ( 105 , 107 ) in order to actuate plunger ( 124 ).
[0039] As mentioned above, hydraulic cylinder ( 102 ) has two fluid channels ( 105 , 107 ) on opposite ends of hydraulic cylinder ( 102 ). Additionally, as mentioned above, first fluid chamber ( 106 A) and second fluid chamber ( 106 B) are in fluid isolation from one another. First fluid channel ( 107 ) may be in fluid communication with first chamber ( 106 A) while second fluid channel ( 105 ) may be in fluid communication with second chamber ( 106 B). One fluid channel ( 105 , 107 ) may be in communication with a fluid source such as a pump while the other fluid channel ( 105 , 107 ) may be in fluid communication with another fluid source such as a reservoir. Fluid sources in fluid communication with channels ( 105 , 107 ) may fill first chamber ( 106 A) with hydraulic fluid while emptying second chamber ( 106 B) with hydraulic fluid. Because first chamber ( 106 A) and second chamber ( 106 B) are in fluid isolation, plunger ( 124 ) and the rest of linear actuating assembly ( 120 ) may actuate, similar to that shown in FIGS. 1A-1B and FIGS. 4A-4C , due to the change in volume of chambers ( 106 A, 106 B).
[0040] It should be understood that there may be additional, external forces acting on hydraulic actuator assembly ( 100 ) which the pressure in first fluid chamber ( 106 A) or second fluid chamber ( 106 B) may need to overcome in order to actuate linear actuating assembly ( 120 ). For instance, if attachment feature ( 126 ) is connected to a portion of a vehicle lift assembly that is supporting a portion of a vehicle, the force provided by the pressure in first fluid chamber ( 106 A) acting on radial face ( 136 ) may need to overcome the load provided from supporting a portion of the vehicle.
[0041] For example, as shown in FIGS. 1A-1B and FIGS. 4A-4C , if hydraulic fluid is filled within first chamber ( 106 A) while hydraulic fluid is emptied from second chamber ( 106 B), an upward force is generated on plunger ( 124 ), which actuates linear actuating assembly ( 120 ) in an upward direction with respect to hydraulic cylinder ( 102 ). In the opposite way, if hydraulic fluid is emptied from first chamber ( 106 A) while hydraulic fluid is being filled within the second chamber ( 106 B), a downward force may be generated on plunger ( 124 ), which actuates linear actuating assembly ( 120 ) in a downward direction with respect to hydraulic cylinder ( 102 ).
[0042] Linear displacement measuring assembly ( 130 ) includes a rotation sensor ( 140 ) and a rotational actuating assembly ( 150 ). Rotation sensor ( 140 ) includes a rotating element ( 142 ) rotatably housed within a static element ( 148 ). Static element ( 148 ) is fixedly housed within rotary sensor mount ( 108 ) of hydraulic cylinder ( 102 ). Static element ( 148 ) may not rotate or actuate relative to hydraulic cylinder ( 102 ). Rotating element ( 142 ) defines an aperture ( 144 ) and a keyed hole ( 146 ). Static element ( 148 ) is configured to measure the rotational displacement of rotating element ( 142 ). As will be described in greater detail below, rotation sensor ( 140 ) is in electrical communication with a circuit board of a vehicle lift assembly or related sensing and/or control circuitry. The vehicle lift assembly may utilize the rotational displacement of rotating element ( 142 ) relative to static element ( 148 ) in order to monitor the positions of each of any number of hydraulic actuator assemblies ( 100 ) utilized in the vehicle lift assembly, using the rotational displacement to calculate the linear displacement of each hydraulic actuator assembly ( 100 ), and using that calculated linear displacement in a feedback control loop to manage the operation of the collection of hydraulic actuator assemblies ( 100 ).
[0043] Rotational actuating assembly ( 150 ) includes a rotating shaft ( 152 ) and a keyed member ( 156 ). Rotating shaft ( 152 ) extends from a free end ( 154 ) to a coupling end ( 158 ). Coupling end ( 158 ) is housed within aperture ( 144 ) of rotation sensor ( 140 ), while keyed member ( 156 ) is housed with keyed hole ( 146 ). Coupling end ( 158 ) may be dimensioned for an interference fit with aperture ( 144 ) such that rotating shaft ( 152 ) may not actuate in the vertical direction relative to rotating element ( 142 ). For example, free end ( 154 ) may be dimensioned small enough to fit within aperture ( 144 ) while coupling end ( 158 ) may be dimensioned for an interference fit. Rotating shaft ( 152 ) may be inserted through aperture ( 144 ) via free end ( 154 ) until coupling end ( 158 ) develops an interference fit with aperture ( 144 ). Of course, rotating shaft ( 152 ) may be fixed in a vertical direction relative to rotating element ( 142 ) in any other suitable manner as would be apparent to one having ordinary skill in the art in view of the teachings herein. For example, coupling end ( 158 ) may be fixed to a bearing attached to base end ( 116 ) of cylinder assembly ( 110 ).
[0044] Rotating shaft ( 152 ) also defines a helical slot ( 155 ) extending from coupling end ( 158 ) towards free end ( 154 ). Helical slot ( 155 ) is dimensioned to receive pin ( 125 ). As seen in FIGS. 4A-4C , as hydraulic fluid enters chamber ( 106 A) and exits chamber ( 106 B), linear actuating assembly ( 120 ) moves from a withdrawn position to an extended position. Additionally, pin ( 125 ) travels along helical slot ( 155 ), providing a camming effect to rotate rotating shaft ( 152 ) about the axis defined by movement of linear actuating assembly ( 120 ). As described above, keyed member ( 156 ) and coupling end ( 158 ) are rotationally fixed to rotating element ( 142 ) of rotation sensor ( 140 ) via keyed hole ( 146 ) and aperture ( 144 ). Therefore, as pin ( 125 ) rotates rotating shaft ( 152 ) via movement of linear actuating assembly ( 120 ), coupling end ( 158 ) and keyed member ( 156 ) rotate rotating element ( 142 ) relative to static element ( 148 ) of rotation sensor ( 140 ). Static element ( 148 ) may measure the rotational displacement of rotating element ( 142 ). Helical slot ( 155 ) may be shaped and dimensioned such that rotation of rotating shaft ( 152 ) directly correlates to linear displacement of linear actuating assembly ( 120 ) along rotating shaft ( 152 ). In other words, linear displacement measuring assembly ( 130 ) may measure the linear displacement of linear actuating assembly ( 120 ) relative to cylinder assembly ( 110 ) by measuring the rotation of rotating shaft ( 152 ) caused by camming action of pin ( 125 ).
[0045] It should be understood that since rotation of rotating shaft ( 152 ) relative to linear actuating assembly ( 120 ) is used to measure linear displacement of linear actuating assembly ( 120 ), there should be no accidental rotation about the axis defined by movement of linear actuating assembly ( 120 ) of rotating shaft ( 152 ) relative to linear actuating assembly ( 120 ). Accidental rotation of rotating shaft ( 152 ) relative to linear actuating assembly ( 120 ) could give a false reading of linear displacement along the axis defined by movement of linear actuating assembly ( 120 ). Therefore, attachment features ( 112 , 126 ) need to rotationally fix cylinder assembly ( 110 ) and linear actuating assembly ( 120 ) relative to one another, along the axis defined by movement of linear actuating assembly ( 120 ), to prevent false readings. While in the current example, attachment features ( 112 , 126 ) include pin eyes, any other suitable attachment features may be used as would be apparent to one having ordinary skill in the art.
[0046] Having linear displacement measuring assembly ( 130 ), or at least a portion of linear displacement measuring assembly ( 130 ) stored within cylinder assembly ( 110 ) and linear actuating assembly ( 120 ), may provide benefits of protecting linear displacement measuring assembly ( 130 ) from external moving parts, dust, and debris. Additionally, linear displacement measuring assembly ( 130 ) may be rigid for durability, as compared to known string potentiometers currently used.
B. First Alternative Hydraulic Actuator Assembly
[0047] FIGS. 9A-9C show an alternative exemplary hydraulic actuator assembly ( 600 ) that may be readily incorporated into a variety of vehicle lift assemblies in place of hydraulic actuator assembly ( 100 ) described above. Hydraulic actuator assembly ( 600 ) includes a cylinder assembly ( 610 ), a linear actuating assembly ( 620 ), and a linear transducer assembly ( 630 ).
[0048] Cylinder assembly ( 610 ) and linear actuating assembly ( 620 ) may be substantially similar to cylinder assembly ( 110 ) and linear actuating assembly ( 120 ) described above, respectively, with differences described below. Therefore, linear actuating assembly ( 620 ) may move relative to cylinder assembly ( 610 ) from a fully withdrawn position, as shown in FIG. 9A , to a fully extended position, as shown in FIG. 9C . Additionally, linear actuating assembly ( 620 ) may move to any number of positions between the fully withdrawn and fully extended position. Therefore, movement of linear actuating assembly ( 620 ) may actuate a vehicle lift assembly to raise or lower a vehicle to a desired height, similar to the process described above for hydraulic actuator assembly ( 100 ). Such vehicle lift assembly may include a scissor lift assembly, a carriage-style lift assembly, an in-ground lift assembly, an above-ground lift assembly, or any other suitable lift assembly that would be apparent to those having ordinary skill in the art in view of the teachings herein.
[0049] Cylinder assembly ( 610 ) includes a hydraulic cylinder ( 602 ) and an attachment feature ( 612 ), which are substantially similar to hydraulic cylinder ( 102 ) and attachment feature ( 112 ) described above, respectively. Hydraulic cylinder ( 602 ) includes an interior base end ( 616 ), an interior annular wall ( 614 ), and an interior head end ( 618 ), which are substantially similar to interior base end ( 116 ), interior annular wall ( 114 ), and interior head end ( 118 ) described above, respectively. Interior base end ( 616 ), interior annular wall ( 614 ), and interior head end ( 618 ) collectively define cavity ( 606 ).
[0050] Head end ( 618 ) defines tunnel ( 604 ) extending from cavity ( 606 ) to an exterior of hydraulic cylinder ( 602 ). Tunnel ( 604 ) is dimensioned to slidably house a rod ( 622 ) of linear actuating assembly ( 620 ) while cavity ( 606 ) is dimensioned to slidably house a plunger ( 624 ) of linear actuating assembly ( 620 ). Plunger ( 624 ) and rod ( 622 ) are substantially similar to plunger ( 124 ) and rod ( 122 ) described above, respectively, with differences described below. Therefore, plunger ( 624 ) and rod ( 622 ) are coupled with each other such that plunger ( 624 ) and rod ( 622 ) slide together relative to tunnel ( 604 ) and cavity ( 606 ).
[0051] Hydraulic cylinder ( 602 ) also has fluid channels ( 605 , 607 ), which are substantially similar to fluid channels ( 105 , 107 ) described above, respectively. Therefore, each fluid channel ( 605 , 607 ) is in fluid communication with a chamber ( 606 A, 606 B). Chambers ( 606 A, 606 B) are substantially similar to chambers ( 106 A, 106 B) described above. Chamber ( 606 A) is defined by interior base end ( 616 ), interior annular wall ( 614 ), and a radial face ( 636 ) of plunger ( 624 ). Chamber ( 606 B) is defined by interior head end ( 618 ), interior annular wall ( 615 ), and a radial face ( 634 ) of plunger ( 624 ). It should be understood that because plunger ( 624 ) is slidable within cavity ( 606 ), chambers ( 606 A, 606 B) are capable of changing in volume as plunger ( 624 ) actuates within cavity ( 606 ).
[0052] Each fluid channel ( 605 , 607 ) may fill respective chamber ( 606 A, 606 B) with hydraulic fluid. Tunnel ( 604 ) and rod ( 622 ) may fluidly isolate chamber ( 606 B) from the exterior of hydraulic cylinder ( 602 ) by using a seal gland or in any other suitable manner known to the art in view of the teachings herein. As will be described in greater detail herein, fluid channels ( 605 , 607 ) may help actuate plunger ( 624 ) within cavity ( 606 ).
[0053] Base end ( 616 ) defines a sensor mount ( 608 ) dimensioned to house a portion of linear transducer assembly ( 630 ). Sensor mount ( 608 ) is capable of fixing a portion of linear transducer assembly ( 630 ). While in the current example, sensor mount ( 608 ) is a recess defined by base end ( 616 ), bolts, nuts, threaded rods, or any other suitable structures may be utilized to fix a portion of linear transducer assembly ( 630 ) to hydraulic cylinder ( 602 ).
[0054] Linear actuating assembly ( 620 ) includes rod ( 622 ) having one end fixed to plunger ( 624 ) and another end fixed to an attachment feature ( 626 ). Rod ( 622 ) defines a channel ( 628 ). Channel ( 628 ) extends from a portion of rod ( 622 ) that is fixed to plunger ( 624 ) toward the portion of rod ( 622 ) fixed to attachment feature ( 626 ). A seal ( 625 ) may be located at the open end of channel ( 628 ) or any other suitable location within channel ( 628 ) as would be apparent to one having ordinary skill in the art in view of the teachings herein. As will be described in greater detail below, seal ( 625 ) may prevent hydraulic fluid from entering certain portions of channel ( 628 ). However, it should be understood that seal ( 625 ) is merely optional.
[0055] Attachment feature ( 626 ) may be substantially similar to attachment feature ( 126 ) described above, with differences described below. Attachment feature ( 626 ) may rotatably couple rod ( 622 ) to a portion of vehicle lift assembly. However, it should be understood that rotatably coupling rod ( 622 ) to a vehicle lift assembly is merely optional. For instance, rod ( 622 ) may couple with vehicle lift assembly in any suitable manner that would be apparent to one having ordinary skill in the art in view of the teachings herein.
[0056] As mentioned above, plunger ( 624 ) is slidably housed within cavity ( 606 ). Plunger ( 624 ) makes contact with interior annular wall ( 614 ). Circumferential face ( 632 ) of plunger ( 624 ) may be machined with grooves configured to fit elastomeric or metal seals and bearing elements. Therefore, plunger ( 624 ) is configured to separate cavity ( 606 ) into two fluidly isolated chambers ( 606 A, 606 B).
[0057] Linear transducer assembly ( 630 ) includes a coil assembly ( 640 ) fixed within hydraulic cylinder ( 602 ) via a base ( 642 ), and an actuating transducer member ( 644 ) fixed to rod ( 622 ) at the closed end of channel ( 628 ) via actuating coupling portion ( 646 ). Actuating coupling portion ( 646 ) may include any suitable coupling means known to one having ordinary skill in the art in view of the teachings herein. For example, actuating coupling portion ( 646 ) may include welding, an interference fit, bolts, and the like as will occur to those having ordinary skill in the art in view of this disclosure.
[0058] Additionally, actuating transducer member ( 644 ) is slidably housed within coil assembly ( 640 ) via an opening ( 641 ) defined at the open end of coil assembly ( 640 ). Actuating transducer member ( 644 ) also includes a core member ( 648 ) located at the end of actuating transducer member ( 644 ) opposite actuating coupling portion ( 646 ). Of course, coil member ( 648 ) may be located at any other suitable location along actuating transducer member ( 644 ) as would occur to one having ordinary skill in the art in view of the teaching here.
[0059] Coil assembly ( 640 ), actuating transducer member ( 644 ), and coil member ( 648 ) may function like a linear variable differential transformer. Coil assembly ( 640 ) is able to determine the location of core member ( 648 ) within opening ( 641 ) of coil assembly ( 640 ). Because core member ( 648 ) is fixedly attached to actuating transducer member ( 644 ), which is also fixedly attached to linear actuating assembly ( 620 ); and coil assembly ( 640 ) is fixedly attached within cylinder assembly ( 610 ); coil member ( 640 ) is capable of measuring the displacement of linear actuating assembly ( 620 ) relative to cylinder assembly ( 610 ) based on the location of core member ( 648 ). In other words, coil assembly ( 640 ) may determine the location of linear actuating assembly ( 620 ) relative to cylinder assembly ( 610 ) by locating core member ( 648 ).
[0060] As mentioned above, seal ( 625 ) may prevent hydraulic fluid from entering certain portions of channel ( 628 ). In particular, seal ( 625 ) may be placed within channel ( 628 ) to prevent hydraulic fluid from entering within opening ( 641 ) of coil assembly ( 640 ).
[0061] Unlike linear displacement measuring assembly ( 130 ) descried above, linear transducer assembly ( 630 ) may correctly measure the distance between linear actuating assembly ( 620 ) and cylinder assembly ( 610 ) even if there is accidental rotation of linear actuating assembly ( 620 ) relative to cylinder assembly ( 610 ).
[0062] Having at least a portion of linear transducer assembly ( 630 ) stored within cylinder assembly ( 610 ) and linear actuating assembly ( 620 ) may provide benefits of protecting linear displacement measuring assembly ( 630 ) from external moving parts, dust, and debris. Additionally, linear displacement measuring assembly ( 630 ) may be rigid for durability, as compared to known string potentiometers currently used.
[0063] As will be described in greater detail below, coil assembly ( 640 ) is in electrical communication with a circuit board of a vehicle lift assembly or related sensing and/or control circuitry. The vehicle lift assembly may utilize the displacement of core member ( 648 ) within coil assembly ( 640 ) in order to monitor the positions of each of any number of hydraulic actuator assemblies ( 600 ) utilized in the vehicle lift assembly, using the displacement to calculate the linear displacement of each hydraulic actuator assembly ( 600 ), and using that calculated linear displacement in a feedback control loop to manage the operation of the collection of hydraulic actuator assemblies ( 600 ).
C. Second Alternative Hydraulic Actuator Assembly
[0064] FIGS. 10A-10C show an alternative exemplary hydraulic actuator assembly ( 700 ) that may be readily incorporated into a variety of vehicle lift assemblies. Therefore, hydraulic actuator assembly ( 700 ) may be used in substitution for hydraulic actuator assembly ( 100 , 600 ) described above. Hydraulic actuator assembly ( 700 ) includes a cylinder assembly ( 710 ), a linear actuating assembly ( 720 ), and a linear transducer assembly ( 730 ).
[0065] Cylinder assembly ( 710 ) and linear actuating assembly ( 720 ) may be substantially similar to cylinder assembly ( 110 ) and linear actuating assembly ( 120 ) described above, respectively, with differences described below. Therefore, linear actuating assembly ( 720 ) may move relative to cylinder assembly ( 710 ) from a fully withdrawn position, as shown in FIG. 10A , through a partially extended position, as shown in FIG. 10B , to a fully extended position, as shown in FIG. 10C . Additionally, linear actuating assembly ( 720 ) may move to any number of positions between the fully withdrawn and fully extended position. Therefore, movement of linear actuating assembly ( 720 ) may be used to actuate a vehicle lift assembly to raise or lower a vehicle to a desired height, similar to the process described above for hydraulic actuator assembly ( 100 ). Such vehicle lift assembly may include a scissor lift assembly, a carriage-style lift assembly, an in-ground lift assembly, an above-ground lift assembly, or any other suitable lift assembly that would be apparent to one having ordinary skill in the art in view of the teachings herein.
[0066] Cylinder assembly ( 710 ) includes a hydraulic cylinder ( 702 ) and an attachment feature ( 712 ), which are substantially similar to hydraulic cylinder ( 102 ) and attachment feature ( 112 ) described above, respectively. Therefore, hydraulic cylinder ( 702 ) includes an interior base end ( 716 ), an interior annular wall ( 714 ), and an interior head end ( 718 ), which are substantially similar to interior base end ( 116 ), interior annular wall ( 114 ), and interior head end ( 118 ) described above, respectively. Interior base end ( 716 ), interior annular wall ( 714 ), and interior head end ( 718 ) collectively define cavity ( 706 ).
[0067] Head end ( 718 ) defines tunnel ( 704 ) extending from cavity ( 706 ) to an exterior of hydraulic cylinder ( 702 ). Tunnel ( 704 ) is dimensioned to slidably house a rod ( 722 ) of linear actuating assembly ( 720 ), while cavity ( 706 ) is dimensioned to slidably house a plunger ( 724 ) of linear actuating assembly ( 720 ). Plunger ( 724 ) and rod ( 722 ) are substantially similar to plunger ( 124 ) and rod ( 122 ) described above, respectively, with differences described below. Therefore, plunger ( 724 ) and rod ( 722 ) are coupled with each other such that plunger ( 724 ) and rod ( 722 ) slide relative to tunnel ( 704 ) and cavity ( 706 ) together.
[0068] Hydraulic cylinder ( 702 ) also has fluid channels ( 705 , 707 ), which are substantially similar to fluid channels ( 105 , 107 ) described above, respectively such that each fluid channel ( 705 , 707 ) is in fluid communication with a chamber ( 706 A, 706 B). Chambers ( 706 A, 706 B) are substantially similar to chambers ( 106 A, 106 B) described above. Therefore, chamber ( 706 A) is defined by interior base end ( 716 ), interior annular wall ( 714 ), and a radial face ( 736 ) of plunger ( 724 ). Chamber ( 706 B) is defined by interior head end ( 718 ), interior annular wall ( 715 ), and a radial face ( 734 ) of plunger ( 724 ). It should be understood that because plunger ( 724 ) is slidable within cavity ( 706 ), chambers ( 706 A, 706 B) are capable of changing volume as plunger ( 724 ) actuates within cavity ( 706 ).
[0069] Each fluid channel ( 705 , 707 ) may fill respective chamber ( 706 A, 706 B) with hydraulic fluid. Tunnel ( 704 ) and rod ( 722 ) may fluidly isolate chamber ( 706 B) from the exterior of hydraulic cylinder ( 702 ) by using a seal gland or in any other suitable manner known to the art in view of the teachings herein. As will be described in greater detail below, fluid channels ( 705 , 707 ) may help actuate plunger ( 724 ) within cavity ( 706 ).
[0070] Base end ( 716 ) defines a sensor mount ( 708 ) dimensioned to house a portion of linear string potentiometer assembly ( 730 ). Sensor mount ( 708 ) is capable of fixing a portion of linear string potentiometer assembly ( 730 ), and in the current example, sensor mount ( 708 ) is a recess defined by base end ( 716 ). Bolts, nuts, threaded rods, or any other suitable structures may be utilized to fix a portion of linear string potentiometer assembly ( 730 ) to hydraulic cylinder ( 702 ).
[0071] Linear actuating assembly ( 720 ) includes rod ( 722 ) having one end fixed to plunger ( 724 ) and another end fixed to an attachment feature ( 726 ). Attachment feature ( 726 ) may be substantially similar to attachment feature ( 126 ) described above, with differences described below. Therefore, attachment feature ( 726 ) may allow rod ( 722 ) to rotatably couple to a portion of vehicle lift assembly. However, it should be understood that rotatably coupling rod ( 722 ) to a vehicle lift assembly is merely optional.
[0072] As mentioned above, plunger ( 724 ) is slidably housed within cavity ( 706 ). Plunger ( 724 ) makes contact with interior annular wall ( 714 ). Circumferential face ( 732 ) of plunger ( 724 ) may be machined with grooves configured to fit elastomeric or metal seals and bearing elements. Therefore, plunger ( 724 ) is configured to separate cavity ( 706 ) into two fluidly isolated chambers ( 706 A, 706 B).
[0073] Linear string potentiometer assembly ( 730 ) includes a sensor assembly ( 740 ) fixed to cylinder assembly ( 710 ) via sensor mount ( 708 ), a measuring cable ( 742 ), and a coupling feature ( 744 ). A portion of measuring cable ( 742 ) is housed within sensor assembly ( 740 ). Measuring cable ( 742 ) is capable of extending and retracting relative to sensor assembly ( 740 ). Coupling feature ( 744 ) fixes an end of measuring cable ( 742 ) to radial face ( 736 ) of plunger ( 724 ). Therefore, measuring cable ( 742 ) extends and retracts relative to sensor assembly ( 740 ) in accordance with linear actuating assembly ( 720 ) actuating within hydraulic cylinder ( 702 ).
[0074] Sensor assembly ( 740 ) and measuring cable ( 742 ) are configured to act as standard string potentiometer. Therefore, as measuring cable ( 742 ) extends and retracts relative to sensor assembly ( 740 ), sensor assembly ( 740 ) may measure the distance defined by the portion of measuring cable ( 742 ) extending from sensor assembly ( 740 ). Because measuring cable ( 742 ) is fixed to plunger ( 724 ) at one end, and sensor assembly ( 740 ) is fixed to cylinder assembly ( 710 ), measuring cable ( 742 ) and sensor assembly ( 740 ) are configured to measure the displacement of linear actuating assembly ( 720 ) relative to cylinder assembly ( 710 ).
[0075] Having at least a portion of linear string potentiometer assembly ( 730 ) stored within cylinder assembly ( 710 ) and linear actuating assembly ( 720 ) may provide benefits of protecting linear string potentiometer assembly ( 730 ) from external moving parts, dust, and debris.
D. Exemplary Vehicle Lift Assembly
[0076] FIG. 5 shows a perspective view of vehicle lift system ( 200 ) in a raised position. Vehicle lift system ( 200 ) comprises two runways ( 220 ), four lift assemblies ( 250 ), a control circuit ( 500 ), and a pump ( 400 ). Runways ( 220 ) are generally rectangular in shape, extending from one lift assembly ( 250 ) to another. Each runway ( 220 ) comprises two longitudinally extending side rails ( 222 ) and a relatively flat top plate ( 224 ). Side rails ( 222 ) are comprised of any suitable rigid material, such as steel, iron, aluminum, composites, etc. Although side rails ( 222 ) are shown as having a generally rectangular construction, it should be understood that side rails ( 222 ) may have any suitable cross-sectional geometry such as square, round, I-shaped, L- shaped, Z-shaped, or the like.
[0077] Top plate ( 224 ) is secured to the top of side rails ( 222 ) by any suitable means such as welding, mechanical fastening, adhesive boding, etc. In the present example, top plate ( 224 ) is comprised of a thin sheet of a rigid material such as steel, iron, aluminum, composite, or the like. Top plate ( 224 ) is configured to support the load of a vehicle resting on runways ( 220 ). The load of a vehicle is also distributed by top plate ( 224 ) to runways ( 220 ), which provide additional structural rigidity.
[0078] Each runway ( 220 ) is positioned relative to the other a transverse distance that is approximately equivalent to the wheel track of a vehicle that is desired to be lifted. The transverse distance thus permits a vehicle's wheels to rest on top of runways ( 220 ). In some embodiments, runways ( 220 ) may include angled sloped ramps (not shown) or other features to facilitate rolling or driving a vehicle onto and off of runways ( 220 ). Of course, such a feature is entirely optional and may be omitted in other comments. Runways ( 220 ) may also include other features suitable to support a vehicle as will be apparent to one of ordinary skill in the art in view of the teachings herein. Some examples of additional and/or alternative features that may be incorporated into runways ( 220 ) and/or other features of lift system ( 200 ) are disclosed in U.S. Pat. No. 6,763,916, entitled “Method and Apparatus for Synchronizing a Vehicle Lift,” issued Jul. 20, 2004, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 6,059,263, entitled “Automotive Alignment Lift,” issued May 9, 2000, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 5,199,686, entitled “Non-Continuous Base Ground Level Automotive Lift System,” issued Apr. 6, 1993, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 5,190,122, entitled “Safety Interlock System,” issued Mar. 2, 1993, the disclosure of which is incorporated by reference herein; U.S. Pat. No. 5,096,159, entitled “Automotive Lift System,” issued Mar. 17, 1992, the disclosure of which is incorporated by reference herein; and U.S. Pub. No. 2012/0048653, entitled “Multi-Link Automotive Alignment Lift,” published Mar. 1, 2012, the disclosure of which is incorporated by reference herein. It should be understood that that the teachings herein may be readily combined with the teachings of the various references cited herein.
[0079] As can be seen in FIGS. 6A-6B , and as will be discussed in greater detail below, vehicle lift ( 200 ), by using runways ( 220 ) and lift assemblies ( 250 ), is operable to lift a vehicle vertically from a height approximately even with a shop floor to a desired working height. As will be understood, lift assemblies ( 250 ) are operable to lift runways ( 220 ) with substantially vertical movement of runways ( 220 ).
[0080] FIG. 7 shows an exploded view of lift assembly ( 250 ). Lift assembly ( 250 ) comprises a base ( 252 ), a linkage assembly ( 260 ), and an actuation assembly ( 350 ). Base ( 252 ) comprises a generally rectangular base plate ( 254 ) and two mounting brackets ( 257 ). Base plate ( 254 ) may be comprised of a rigid material such as steel, iron, aluminum, composite, or the like. Base plate ( 254 ) is shown as having a plurality of mounting holes ( 256 ). In the present example, mounting holes ( 256 ) may be used to receive bolts and/or other anchors to mount base plate ( 254 ) to a shop floor, thus providing a fixed platform for lifting assembly ( 250 ). In other examples, mounting holes ( 256 ) may be omitted entirely and base plate ( 254 ) may be secured to a shop floor by some other means such as welding, adhesive bonding, mechanical fastening, etc. Yet in other examples, mounting holes ( 256 ) may be used to secure lift assembly ( 250 ) to another surface such as a portable rack for vehicle lift systems ( 200 ) designed for smaller vehicles.
[0081] Mounting brackets ( 257 ) extend vertically from base plate ( 254 ). Mounting brackets ( 257 ) may be fixedly secured to base plate ( 254 ) by any suitable means such as welding, adhesive bonding, mechanical fastening, and/or the like. Alternatively, mounting brackets ( 257 ) may be integral to base plate ( 254 ). As can best be seen in FIG. 7 , each mounting bracket ( 257 ) comprises a pair of mounting holes ( 258 , 259 ). As will be described in greater detail below, components of linkage assembly ( 260 ) and actuation assembly ( 350 ) are rotatably coupled to mounting brackets ( 257 ).
[0082] Mounting holes ( 258 , 259 ) are positioned at each end of mounting bracket ( 257 ). In particular, a rear mounting hole ( 258 ) is positioned near the rear of mounting bracket ( 257 ), and a front mounting hole ( 259 ) is positioned near the front of mounting bracket ( 257 ). Rear mounting hole ( 258 ) is positioned vertically higher than front mounting hole ( 259 ). As will be understood in view of the description below, mounting holes ( 258 , 259 ) are oriented such that linkage assembly ( 260 ) and actuation assembly ( 350 ) are operable to fold up, thus minimizing the height of vehicle lift system ( 200 ) when vehicle lift system ( 200 ) is in the retracted position as shown in FIG. 6A . Accordingly, the shape of mounting brackets ( 257 ) is configured to arrange mounting holes ( 258 , 259 ) in the positions described above. Thus, although mounting brackets ( 257 ) are shown as having a particular shape, mounting brackets ( 257 ) may be of any suitable shape as will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0083] Turning to FIGS. 8A-8B , linkage assembly ( 260 ) comprises a set of four lower links ( 262 ) and a third pair of armatures ( 282 ). Lower links ( 262 ) comprise a first pair of armatures ( 264 ) and a second pair of armatures ( 272 ). First armatures ( 264 ) are generally similar, having the same size and shape, and comprising an elongated portion ( 266 ) positioned between two rounded end portions ( 268 ). Likewise, second armatures ( 272 ) are generally similar, having the same size and shape, and comprising an elongated portion ( 274 ) positioned between two rounded end portions ( 276 ). Although they differ in shape, the rounded end portions ( 268 , 276 ) of lower links ( 262 ) each comprise bores ( 270 , 278 ) that permit the first and second pairs of armatures ( 264 , 272 ) to be respectively attached to pins ( 296 , 298 ) associated with mounting brackets ( 257 ) at one end, and pins ( 300 , 302 ) associated with third armatures ( 282 ) at another end. It should be noted that each pair of rounded end portions ( 268 , 276 ) do not necessarily have equal dimensions.
[0084] As can be seen in FIGS. 8A-8B , first armatures ( 264 ) are generally longer in length relative to second armatures ( 272 ). As will be described in greater detail below, the greater length of first armatures ( 264 ) relative to second armatures ( 272 ) is generally necessitated by the configuration of linkage assembly ( 260 ). Although lower links ( 262 ) are shown as having a certain length, it should be understood that their lengths may be varied depending on the design specifications of vehicle lift system ( 200 ). For instance, some vehicle lift systems ( 200 ) may be designed to have a higher or lower working height. Thus, longer or shorter lower links ( 262 ) may be used to increase or decrease the range of motion of lift assembly ( 250 ), respectively.
[0085] Elongated portions ( 266 , 274 ) of lower links ( 262 ) are generally rectangular in shape. Alternatively, any suitable shape may be used, such as an elongated rod, elongated hexagon, hollow tubing, or the like. Rounded end portions ( 268 , 276 ) are generally circular to accommodate bores ( 270 , 278 ) and generally reduce the area occupied by rounded end portions ( 268 , 276 ). In other examples, rounded end portions ( 268 , 276 ) may have any suitable shape. Lower links ( 262 ) are relatively rigid and may be comprised of any suitable material such as steel, iron, aluminum, composite, or the like. Of course, lower links ( 262 ) may have any other suitable configuration and composition as will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0086] Third armatures ( 282 ) are generally the same size and shape. In particular, each third armature ( 282 ) is approximately rectangular and includes a taper from one end to another. The front end of third armature ( 282 ) is wider relative to the rear end to accommodate two connecting bores ( 284 , 285 ). As will be described in greater detail below, upper connecting bore ( 284 ) and lower connecting bore ( 285 ) are used to rotatably couple lower links ( 262 ) to third armatures ( 282 ) via pins ( 300 , 302 ) respectively. As will also be described in greater detail below, connecting bores ( 284 , 285 ) are positioned on third armature ( 282 ) to provide pivot points about which lower links ( 262 ) may pivot relative to third armature ( 282 ). The rear end of third armature ( 282 ) is rounded and includes an attachment bore ( 286 ). Attachment bore ( 286 ) is positioned to permit rotatable coupling between third armature ( 282 ) and runway ( 220 ) via pin ( 304 ) and pin blocks (not shown).
[0087] As can best be seen in FIG. 7 , lift assembly ( 250 ) includes a plurality of pins ( 296 , 298 , 300 , 302 ) that rotatably couple various components of lift assembly ( 250 ). In particular, bore ( 270 ) of the lower portion of first armatures ( 264 ) is rotatably coupled to rear mounting holes ( 258 ) of mounting brackets ( 257 ) via pin ( 296 ). Pin ( 296 ) may be welded or fixed to mounting bracket ( 257 ) of base ( 252 ) by any suitable methods as will be apparent to one of ordinary skill in the art in view of the teachings herein. Bore ( 278 ) of the lower portion of second armatures ( 272 ) is rotatably coupled to front mounting holes ( 259 ) of mounting brackets ( 257 ) via pin ( 298 ). Pin ( 298 ) may be welded or fixed to mounting bracket ( 257 ) of base ( 252 ) by any suitable methods as will occur to one of ordinary skill in the art in view of the teachings herein. Alternatively, pin ( 298 ) may rotate freely relative to mounting bracket ( 257 ). As described above, pin ( 298 ) at this joint also rotatably couples to attachment feature ( 112 ) of hydraulic actuator assembly ( 100 ). Similarly, another pin ( 300 ) provides rotatable coupling between upper connecting bore ( 284 ) of third armatures ( 282 ), bores ( 270 ) of the upper portions of first armatures ( 264 ), and sleeve ( 362 ). As described above, pin ( 300 ) at this joint also rotatably coupled attachment feature ( 126 ) of hydraulic actuator assembly ( 100 ). Finally, bores ( 278 ) of the upper portions of second armatures ( 272 ) are rotatably coupled to lower connecting bore ( 285 ) of third armatures ( 282 ) via pin ( 302 ). Pin ( 302 ) may be welded or fixed to third armatures ( 282 ) by any suitable methods as will occur to one of ordinary skill in the art in view of the teachings herein. Pins ( 296 , 298 , 300 , 302 ) are shown as being fastened to their respective mating parts using bolts ( 292 ) and washers ( 294 ). Of course, pins ( 296 , 298 , 300 , 302 ) may be fastened to their respective mating parts by any other suitable means. Although not shown, it should be understood that the various joints described above may also include bushings, bearings, or other devices suitable to reduce friction between the various parts.
[0088] FIGS. 8A-8B show linkage assembly ( 260 ) and base ( 252 ) in an exemplary mode of operation as the linkage assembly ( 260 ) transitions from the retracted position to an extended position. It should be understood that the combination of mounting brackets ( 257 ), lower links ( 262 ), and third armatures ( 282 ) forms a four-bar linkage such that rotation of lower links ( 262 ) is operable to produce substantially vertical motion of attachment bore ( 286 ) of third armatures ( 282 ).
[0089] FIG. 8A shows linkage assembly ( 260 ) in the retracted position. As can be seen, lower links ( 262 ) and third armatures ( 282 ) are configured to fold relative to each other so that the lower links ( 262 ) and third armatures ( 282 ) have limited vertical extension. Additionally, hydraulic actuator assembly ( 100 ) is in the withdrawn position. Accordingly, when linkage assembly ( 260 ) is in the retracted position, runway ( 220 ) is relatively close to ground level. Additionally, in the retracted position, lower links ( 262 ) and third armatures ( 282 ) are nearly parallel with each other.
[0090] FIG. 8B shows linkage assembly ( 260 ) in the extended position. As described above, the extended position of linkage assembly ( 260 ) corresponds to runway ( 220 ) being raised to a desired working height. In the operation of transitioning between the retracted position and the extended position, pin ( 300 ) is forced away from pin ( 298 ) via extension of linear activating assembly ( 120 ). Because linkage assembly ( 260 ) is a four-bar linkage, forcing pin ( 298 ) away from pin ( 300 ) causes lower links ( 262 ) to simultaneously rotate about pins ( 296 , 298 ) and pivot third armatures ( 282 ) about a point between the center of pins ( 300 , 302 ). The pivoting action of third armatures ( 282 ) causes attachment bores ( 286 ) of third armatures ( 282 ) to move upwardly. It should be understood that the motion of attachment bores ( 286 ) is substantially vertical as lift assembly ( 250 ) transitions from the retracted position to the extended position. Of course, the precise path of lift assembly ( 250 ) may vary depending on a number of factors such as the length of each armature ( 264 , 272 , 282 ), the relative lengths of armatures ( 264 , 272 , 282 ), and other similar factors.
[0091] As mentioned above and shown in FIGS. 5-8B , each lift assembly ( 250 ) includes a hydraulic actuator assembly ( 100 ). Each hydraulic actuator assembly ( 100 ) is in fluid communication with pump ( 400 ) via a pair of hydraulic hoses ( 402 ). Hydraulic hoses ( 402 ) and pump ( 400 ) may provide fluid communication to fluid channels ( 105 , 107 ) in the same or similar fashion as described above in order to move linear actuating assembly ( 120 ).
[0092] Each hydraulic actuator assembly ( 100 ) is in electrical communication with control circuit ( 500 ) via communication wires ( 502 ). In the current example, communication wires ( 502 ) are connected to rotation sensor ( 140 ) of each hydraulic actuator assembly ( 100 ). Communication wires ( 502 ) may also be in electrical communication with other aspects of each lift assembly ( 250 ).
[0093] Communication wires ( 502 ) may be configured to provide electrical power from circuit board ( 500 ) to rotation sensor ( 140 ). Additionally, rotation sensor ( 140 ) may be able to communicate the rotational displacement of rotating element ( 142 ) relative to static element ( 148 ). As mentioned above, the rotational displacement of rotation element ( 142 ) relative to static element ( 148 ) corresponds to the linear displacement of linear actuating assembly ( 120 ) relative to cylinder assembly ( 110 ). Therefore, circuit board ( 500 ) may be configured to determine the linear displacement of linear actuating assembly ( 120 ) relative to cylinder assembly ( 110 ) through a predetermined formula based on dimensions of hydraulic actuator assembly ( 100 ). Additionally, the linear displacement of linear actuating assembly ( 120 ) relative to cylinder assembly ( 110 ) may correspond with a predetermined height of the portion of lift assembly ( 250 ) directly connected to runways ( 220 ) based on the dimensions of lift assembly ( 250 ). Therefore, circuit board ( 500 ) may be configured to determine the vertical height of the portion of lift assembly ( 250 ) connected to runways ( 220 ), or any other suitable portion of lift assembly ( 250 ) as will be apparent to one having ordinary skill in the art in view of the teachings herein.
[0094] Circuit board ( 500 ) is also in electrical communication with pump ( 400 ). Circuit board ( 500 ) may control the amount of hydraulic fluid that pump ( 400 ) distributes to individual hydraulic actuator assemblies ( 100 ). Therefore, circuit board ( 500 ) may control the individual heights of each hydraulic actuator assembly ( 100 ). For example, circuit board ( 500 ) may determine individual heights of each lift assembly ( 250 ) in order to determine the lowest lift assembly ( 250 ). Circuit board ( 500 ) may then calculate the difference of the heights of each of the other three lift assemblies ( 250 ) in order to equal the lowers lift assembly ( 250 ). Circuit board ( 500 ) may then communicate instructions to pump ( 400 ) in order to adjust the three, higher, lift assemblies ( 250 ) to lower accordingly to equalize the height of each lift assembly ( 250 ). Therefore, communication between linear displacement measuring assembly ( 130 ), circuit board ( 500 ), and pump ( 400 ) may help keep vehicle lift system ( 200 ) level.
[0095] Of course, utilizing the lowest lift assembly ( 250 ) as the datum point is just one option. Circuit board ( 500 ) could determine the highest lift assembly ( 250 ). Circuit board ( 500 ) may then calculate the difference of the heights of each of the other three lower lift assemblies ( 250 ) in order to equal the highest lift assembly ( 250 ). Circuit board ( 500 ) may the communicate instructions to pump ( 400 ) in order to adjust the three, lower, lift assemblies ( 250 ) to raise accordingly to equalize the height of each lift assembly ( 250 ). Any other suitable means of equalizing the height of each lift assembly ( 250 ) may be utilized as would be apparent to one having ordinary skill in the art in view of the teachings herein.
[0096] It should be understood that while in the current example, hydraulic actuator assembly ( 100 ) is used in vehicle lift system ( 200 ), hydraulic actuator assembly ( 600 , 700 ) may be readily incorporated into vehicle lift system ( 200 ) in place of hydraulic actuator ( 100 ).
[0097] While in the current example, vehicle lift system ( 200 ) includes linkage assemblies, armatures, and pins, any other suitable vehicle lift system having a linear displacement measuring assembly ( 130 ) in communication with a circuit board ( 500 ) lift assembly ( 250 ).
[0098] Although actuation assembly ( 350 ) is shown as being hydraulically actuated, it should be understood that any suitable device may be used to actuate lift assembly ( 250 ). For instance, actuation assembly ( 350 ) may comprise a linear actuator having a lead screw and a motor, a pneumatic actuator, spring loaded actuator, or any other suitable actuator as will be apparent to those of ordinary skill in the art in view of the teachings herein.
[0099] The illustrated embodiment is double-acting; that is, it uses pressure fluid on both sides of plunger ( 124 ) in cylinder ( 102 ), and the pressure differential between the two sides moves plunger ( 124 ) axially through the cylinder ( 102 ). In alternative embodiments, cylinder ( 102 ) is single-acting, where there is fluid on only one side of the plunger ( 124 ) (e.g., between plunger ( 124 ) and head end ( 118 )), and the other side of the plunger ( 124 ) (e.g., between plunger ( 124 ) and base end ( 116 )) is air- or gas-filled or even vented. In such embodiments, fluid channel ( 105 ) is a breather that leads air in and out, and fluid channel ( 107 ) is a pressure line/return line. | A vehicle lift includes a vehicle support member, a cylinder, and a controller. A linear transducer—such as a string potentiometer—is (preferably removably) positioned inside the cylinder. The transducer detects the position of the cylinder and sends a corresponding signal to a controller that controls the height of the support member in response to the signal. The cylinder acts on the vehicle support member through a scissor mechanism, parallelogram linkage, or straight vertical hydraulic lifting. | 1 |
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